Basic Claiming: Chapter 4

white space patenting: basic claiming chapter 4



Click to download this chapter of White Space Patenting (pdf includes illustrations)


    1. A)New, Useful and Non-Obvious

As mentioned above, an “invention” must be new, useful and non-obvious to be patentable. It’s usually fairly easy to draft claims so that they satisfy the “new” part (also called “novelty”) of the test, because typically no one has invented exactly the same thing you did. It’s also usually fairly easy to draft claims so that they satisfy the “useful” part of the test. If the invention were not useful you wouldn’t have bothered to invent it – although one has to wonder about some of the absurd inventions people come up with!

The difficult part is satisfying the “non-obviousness” requirement. But what makes an invention non-obvious? We certainly cannot use the common understanding of the terms “obvious” and “non-obvious” because they are too subjective. What is obvious to one person is simply not obvious to another. Indeed, once one learns of an invention, it is all too easy to reach back in one’s mind to think, “Oh yes, I would have thought of that if I had put my mind to it.” But that “hindsight trap” doesn’t make the invention obvious from a patent standpoint.

Basic Claiming Fish Ip Law


    1. B)Past Efforts At Defining Obviousness

Years ago the patent office and courts required that patentable subject matter reflect an extraordinary mental achievement, a so-called “flash of genius”. That standard was quite helpful in the days before computers and automated processes. But a return to the flash of genius standard would be completely unworkable today because a great many inventions result from automated investigation. To give just a single example, pharmaceutical companies regularly screen thousands of compounds to discover those that are most effective for a particular disease. Any “invention” that results may have involved some measure of creativity, but is mostly the result of grinding lab work. In any event, the flash of genius test was rejected long ago when the patent law was expressly amended to state, “Patentability shall not be negatived by the manner in which the invention was made”.

It is also theoretically possible to devise an obviousness standard that depends upon the amount of effort required during the inventing process. That standard would have the advantage of providing at least some correlation between effort and reward, but it flies in the face of experience. Sometimes the greatest advances are the result of accidents and “flashes of genius”, neither of which can necessarily lay claim to having involved much effort at all. Moreover, if an inventor works in a field for ten years before “suddenly” coming up with a great idea, it is difficult to say whether the great idea took ten minutes or ten years to develop. As with the “flash of genius” approach, the “amount of effort” approach has gone the way of the great auk.

      1. (1)The Graham Factors

The current law is that a patent claim is obvious when the differences between the claimed invention and the prior art “are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art“. While obviousness is ultimately a legal determination, it is based on the so-called Graham Factors, namely: (1) the scope and content of the prior art; (2) the level of skill of a person of ordinary skill in the art; (3) the differences between the claimed invention and the teachings of the prior art; and (4) the extent of any objective indicia of non-obviousness (e.g., commercial success, long-felt but unsolved needs, and failure of others to solve the problems addressed by the invention).

      1. (2)Teaching, Suggestion or Motivation

Unfortunately, it can be exceedingly difficult to apply the Graham Factors. The test that is most often used is the whether there is a teaching, suggestion or motivation (“TSM”) in the prior art from which a Person of Ordinary Skill in the Art (a “POSITA”) would have derived the claimed subject matter. Under the TSM rule, a patent claim can be properly rejected if invalidating teaching, suggestion, or motivation can be found explicitly or implicitly: 1) in the prior art references themselves; 2) in the knowledge of those of ordinary skill in the art that certain references, or disclosures in those references, are of special interest or importance in the field; or 3) from the nature of the problem to be solved, “leading inventors to look to references relating to possible solutions to that problem”.

Arguments with the Patent Office usually do not occur with respect to the teaching or suggestion part of the test, because those are relatively straightforward. The motivation part of the test, however, is very commonly argued. The reason is that a POSITA must not only have had some motivation to combine the prior art teachings, but some motivation to combine the prior art teachings in the particular manner claimed.

For better or for worse, the Patent Office has more or less eviscerated the motivation portion of the teaching-suggestion-motivation test, by focusing on the standard of review in cases appealed to the Patent Trial and Appeal Board. The ultimate determination of obviousness is a legal conclusion based on underlying findings of fact, and the Federal Circuit reviews the Board’s ultimate determination of obviousness de novo. However, the Federal Circuit reviews the Board’s underlying factual findings, including a finding of a motivation to combine, for substantial evidence. Thus, as long as the Federal Circuit can find any substantial evidence from which the Board could have determined obviousness, it is proper for the Court to uphold that factual determination. And given a factual determination of motivation to combine, the Court can uphold the final determination of obviousness. That is exactly what was done in the recent In re Kahn case. There, the court reiterated, “[s]ubstantial evidence is something less than the weight of the evidence but more than a mere scintilla of evidence” and went on to conclude:

“We note that the possibility of drawing two inconsistent conclusions from the evidence does not prevent the [Patent Board’s] findings from being supported by substantial evidence. Id. Indeed, if a reasonable mind might accept the evidence as adequate to support the factual conclusions drawn by the Board, then we must uphold the Board’s determination”.

      1. (3)KSR International Co. V. Teleflex Inc. et al.

One of the most important case on obviousness since the turn of the century is the KSR ruling. In that case the U.S. Supreme Court significantly raised the bar on obviousness by holding that a POSITA must be deemed to have an ordinary level of creativity. Among other things, this means that a POSITA would think of all permutations where each of the elements has only a small, finite number of choices — and claims should be rejected where they are directed to inventions that are mere design choices.

Interestingly, KSR’s focus on design choices echoed my previous suggestion in Strategic Patenting. Examiners should still be required to identify a teaching, suggestion or motivation for a claimed combination in the prior art, and they should still consider evidence of non-obviousness, and reasoned arguments as to why a POSITA would not have thought of the claimed combination. But absent sufficiently strong contrary evidence and arguments, examiners should reject claims (and courts should uphold rejections) where the claimed inventions are mere design choices.

Proper application of KSR is absolutely critical to ridding the world of ridiculous patents for “inventions” such as the 1-click placement of Internet orders (US6149255), peanut butter and jelly sandwiches without crusts (US6004596), providing reservations for restroom use (US6329919), printers that print lines with different line spacing (US4953995), Online Shopping Carts (US5715314), The Hyperlink (US4873662), Video Streaming (US5132992), Internationalizing Domain Names (US6182148), Pop-Up Windows (US6389458), Targeted Banner Ads (US6026368), Paying With A Credit Card Online (US6289319), Framed Browsing (US5933841 and 6442574), and Affiliate Linking (US6029141).

Unfortunately, patents claiming subject matters that are completely obvious are still being issued and upheld. For example, Amazon’s original one-click patent US5960411 (Sept. 1997) has never been invalidated, and was even confirmed on re-examination in July 2010. Claim 1 of that patent recites:

Similarly, in the peanut butter and jelly sandwich cases, the Federal Circuit killed one of Smuckers’™ patents, but the patent for a sealed crustless sandwich is still on the books. Claim 1 of the US6004596 patent (December 1999) recites:

There are perhaps hundreds of thousands (if not millions) of parents and children alike who would have found such a sandwich entirely obvious as of the filing date!

There is hope, however. In a November 2013 appeal of a reexamination case, the Federal Circuit found it was obvious for a trailer to have panels that independently move laterally and vertically. That should have been an easy decision. Panels can only move in so many directions, and such movement can only be either dependent or independent. POSITAs are not complete idiots. Here’s claim 1 of US7214017.

      1. (4)Subject Matter Eligibility

Between 2012 and 2014 the Supreme Court issued three other decisions that rocked the patent world, Mayo v. Prometheus, and Ass’n for Mol. Pathology v. Myriad, and Alice v. CLS Bank

In 2012 Mayo held that claims failed to recite patent eligible subject matter where they were directed to a method of giving a drug to a patient, and using measurement of metabolites of that drug to decide whether to increase or decrease the dosage of the drug. The correlation was deemed to be a natural phenomenon.

In 2013 Myriad held that tests based on breast cancer mutations are not patentable because the mutations were merely natural phenomena, and creating an assay based on that principal is routine.

Then in 2014, Alice held that computer-implemented inventions consisting of (1) methods for exchanging obligations, (2) computer system configured to carry out the methods, and (3) computer-readable medium programmed to perform the methods are not patent-eligible because they merely recite abstract ideas without limitation by a critical “something more.”  In one bold stroke the Supreme Court subjecting to invalidity challenges hundreds of thousands of software and business patents.

Actually, Alice was not decided out of the blue. Focusing back to the U.S. Constitution, the Court pointed out that Art. I, § 8 prescribes a balance; providing a limited monopoly to inventors “[t]o promote the progress of science and useful arts”.  The problem, of course, is that the patent statute, 35 USC 100 et seq., contains no language of proportionality. If an inventor can somehow broadly patent some minor improvement in a way that can demand tribute from an entire industry, the patent statute would not stand in its way.

The Court had tried to establish that balance in other cases, as well, for example in KSR v. Teleflex, using 35 USC § 103 (one of ordinary skill has ordinary level of creativity); in Bilski v. Kappos using 35 USC § 101 (machine or transformation is not only test of subject matter eligibility); in Nautilus v. Biosig using 35 US § 112 (claims need to inform with reasonable level of certainty; and in Kimble v. Marvel using 35 USC § 154 (patent royalties cannot contractually extend past term of license).

But then in Alice, the Court for the first time directly addressed the idea of proportionality.  “”[W]e must distinguish between patents that claim the ‘building blocks’ of human ingenuity and those that integrate the building blocks into something more…thereby ‘transforming’ them into a patent-eligible invention. The former ‘would risk disproportionately tying up the use of the underlying’ ideas…and are therefore ineligible for patent protection. The latter pose no comparable risk of pre-emption, and therefore remain eligible for the monopoly granted under our patent laws.” (emphasis added).

Now it is true that very few seem to have caught on to the big picture here.  Instead of focusing on the fuzzy line of proportionality, both lower courts and commentators have sought a bright line test consisting of two parts:

(1) Is the claim at issue directed to a known judicial exception (an idea of itself, a mathematical relationship or formula, a method of organizing human activity, or a fundamental economic practice); and

(2) If yes, then does the claim recite something significantly more that renders the claim subject matter eligible?

Of course, that test merely raises the question of what is something significantly more. And that, it turns out boils down to the fuzzy line of proportionality.  Although very few commentators (and courts) seem to have appreciated it, the Alice Court is basically taking another step towards balancing the contribution to science/arts against the reward to the patentee.

Now comes the big issue, how should applications be drafted to comply with these cases? The first thing to appreciate is that this new emphasis on subject matter eligibility really only affects the business methods and software groups.  Mechanical inventions, physical aspects of electronics, and most other technologies are not seriously affected.

For technologies that do fall within business methods and software, claims should include one, or preferably more, of the following limitations:

  • A limitation focusing on improving another technology or technical field
  • A limitation focusing on improving a function functioning of hardware
  • A limitation that requires implementation on a particular machine, not a general purpose process or computer
  • A limitation that requires that a process transforms a particular article to a different state or thing
  • A limitation reciting an unconventional step, something other than what is well-understood, routine, and conventional in the field
  • A limitation that amounts to more than generally linking an abstract idea to a particular technological environment

The USPTO gives specific examples in its July 2015 update to the 2014 interim guidance. Those examples are “must reads” for anyone drafting business method or software related claims. Above all, when drafting claims directed to these technologies, it is critical to consider the concept of proportionality.  Try to write claims in which the scope of protection is commensurate with the contribution to technology.

For technologies that involve natural compounds, one really needs to either recite a new use of the compound, or a non-obvious derivative of the compound. Myriad invalidated claims that recited assays based on breast cancer mutations, because the mutations were merely natural phenomena, and creating an assay based on that principal is routine.  In Sequenom the Federal Circuit reluctantly invalided claims that recited assays based on presence of fetal DNA in maternal blood. The Court held that the claimed subject matter was not patent eligible because the DNA in the blood is merely a natural phenomenon, and creating an assay based on that principal is routine.

      1. (5)Avoiding Obviousness Rejections

The Patent Office can, and often does, reject a claim as being obvious over a combination of references. For example, if a pending claim recites a combination of elements A, B, and C, the Patent Office might well reject the claim as being obvious over one reference that teaches A and B, and another reference that teaches C.

Of course, the goal when drafting claims is to try to avoid obviousness rejections altogether. And the best way to accomplish that is to run a really good prior art search, draft claims that are a little too broad, but not excessively so, and then pretend you are an examiner trying to reject the claims. Try to construe the language of your draft claims in the broadest possible manner consistent with the application.  If you include the term “user” in a claim, consider whether the claim would be patentable if a user were a computer or robot, not just a person. If you include the term “hammer” in a claim, consider whether the claim would be patentable if a steel bar or a rock were construed as a hammer.  That is what the examiner will do, and it is proper for him/her to interpret the claims in that manner – at least during prosecution.  Later on , if the claims are ever litigated, the court will construe the claim more narrowly, as one of ordinary skill in the art would construe them.

Moreover, take into account the fact that prior art references can be cited against your claims even if the references come from a different technical field.  The rule is that references can only be properly combined if they are in a technical field that a competitor would likely consider in resolving the technical problem at hand, provided the examiner can provide some rationale for combining the references.

And don’t worry that your claims will be rejected as being obvious, despite your good faith efforts to avoid obviousness rejections. Among other things the examiners almost have to reject claims in the first substantive office action, citing whatever they can find. The reality is that unless the examiners reject the claims at least once, it’s difficult for the supervisor to know if the examiners really looked at the prior art.

    1. C)Structure of Claims
      1. (1)I or We Claim

The Claim section of a patent application should begin with one of three phrases: “I claim” or “We claim” or “What is claimed is”. This is mostly a matter of preference, although the first and second choices depend on the number of inventors, and can become incorrect over time if that number changes through claim amendments.

      1. (2)Preamble
        1. (a)Structure Of Preamble

Patent claims contain only two sections, a preamble and a body. The preamble usually introduces the subject matter of the claim, defines a work piece, or states a purpose or use for the invention. The body then goes on to list the elements of the apparatus, composition or method of the claimed invention.

Preambles can be of any length. In U.S. 5969204 claim 1 begins simply “A method…” and in U.S. 5090759 claim 1 begins “An apparatus….” A more typical claim, however, includes somewhat more description in the preamble, such as “A sheet fitting apparatus…”, “A tire removing tool…”, or “A toaster for toasting bagels….” In the extreme case of a Jepson claim (see below), the preamble includes all the important elements of the device or method that are already known, and the body generally only lists those additional elements that the attorney considers to be new.

        1. (b)Strategic Considerations

There are all sorts of strategic reasons for these widely varying formats. One consideration is that the preamble is often used by the patent office to help decide upon the examining group in which to place an application. By consciously drafting the preamble to focus on one technology or another, a patent drafter can more or less direct his application to one examining group or another.

Group 3600, for example, deals with business methods, and is currently behind other groups in their caseload. They are have made significant improvements in recent years, but at one time they were issuing first office actions almost five years after the filing dates! They also have a policy of re-examining PCT applications that enter U.S. national phase, even if the International Preliminary Search Report (IPER) was entirely positive. If an inventor wants his application to issue within a reasonable period of time, it behooves him/her to write the preamble in a manner that targets one of the examining groups that is not generally issuing §101 rejections (rejections for claiming ineligible subject matter). For example, if the invention relates to coupling a refrigerator to the Internet, it may be smart to begin the claim by reciting, “A refrigerator comprising a component that delivers temperature data to a data port…” rather than reciting “A method of delivering temperature date to a data port….”

Where a client contemplates filing multiple applications on a given technology, it can be useful to draft the various preambles to direct the different applications to either the same examining group or to different examining groups. Daughter applications, for example, are sometimes best directed to the same examining group that handled the parent, especially where the previous examiner was helpful in getting previous claims issued. On the other hand, when concurrently filing multiple applications on different aspects of related technologies, it is probably a better idea to direct them to different examining groups. That way a severe backlog in one group doesn’t delay prosecution of the entire portfolio. The strategy also minimizes the possibility that a single poorly trained examiner can hold the entire prosecution hostage. In a recent example, our office successfully directed three different applications in related technologies to three different examining groups. The main claims were as follows:


Another strategic consideration is elimination of “work pieces” from the body of the claim. Consider a claim directed to a sawhorse for supporting lengths of wood. The wood is the work piece. It is separate from the sawhorse, and is properly excluded from the listing of components of the sawhorse. Thus, it would be wrong to recite the following because the sawhorse is described as comprising the length of wood:


The proper claim would read:

Alternatively, a patent drafter can introduce work pieces in the body of the claim as long as it is clear that the work piece is not an element of the device or method being claimed. For example, it would also be proper to recite the following:

A third consideration in drafting preambles is that the preamble can sometimes be read as a limitation on the scope of the claim. When merely introducing the subject matter of the claim, defining a work piece, or stating a purpose or use for an invention, the language of the preamble has little or no effect on the scope of the claim. But when reciting essential structure or steps, or using language that is “necessary to give life, meaning, and vitality” to the claim, the language of the preamble can be interpreted as limiting the scope of the claim.

        1. (c)Potentially Limiting Nature of Preamble

Unfortunately, there is “no litmus test that defines when a preamble limits claim scope”. The general rule is that a preamble “limits the claimed invention if it ‘recites essential structure or steps, or if it is necessary to give life, meaning, and vitality to the claim.’“ Thus, if the preamble helps to determine the scope of the patent claim, and especially if it appears that “the patent drafter chose to use both the preamble and the body of the claim to define the subject matter of the claimed invention” then the limitations in the preamble are construed as part of the claimed invention. But that general rule cannot be applied slavishly. In another recent case the Federal Circuit held:

In general, a claim preamble is limiting if it recites essential structure or steps, or if it is necessary to give life, meaning, and vitality to the claim. However, if the body of the claim describes a structurally complete invention such that deletion of the preamble phrase does not affect the structure or steps of the claimed invention, the preamble is generally not limiting unless there is clear reliance on the preamble during prosecution to distinguish the claimed invention from the prior art”.

ïPreambles In Apparatus claims

It is also possible that some elements in the preamble will be considered limiting while others in the same preamble are not considered limiting. This distinction often happens with respect to structural versus intent elements, and plays out as a function of whether the claim is written in apparatus format or method format. The structural elements recited in the preamble of an apparatus (composition or device) claim are often considered to be limiting because the subject matter is being claimed by its structural elements. In the following claim, for example, the Federal Circuit found the elements “blown-film” and “textured liner” to be limitations on the claimed subject matter.

Among other things, the Court focused on the fact that the language recites a fundamental characteristic of the claimed invention, and that the specification is replete with references to the invention as a “blown-film” liner, including language in the title of the patent and the summary of the Invention. The court noted especially that the phrase is used repeatedly to describe the preferred embodiments, and that the entire preamble “blown-film textured liner” is restated in each of the patent’s seven claims.

On the other hand, language of intent in a preamble of an apparatus claim is usually considered to be non-limiting. That makes sense because the scope of an apparatus claim depends on structure, and recitation of a purpose or intent imposes no limitation on the structure.

          • Preambles In Method claims

The rules regarding interpretation of preamble limitations are the same for method claims, but application of the rule may be a bit easier. In method claims all of the elements recited in a preamble are likely to be deemed limitations on the scope of the claim, regardless of whether they are structural elements or “use” or “intent” elements. The rationale is that a method is performed to accomplish some purpose, and the “use” or “intent” is critical. This difference allows a patent drafter to readily limit the scope of the claim according to the use. In Jansen v. Rexall Sundown, Inc., for example, the Federal Circuit considered the following claim from US4945083.

The issue at litigation was whether the purpose recited in the preamble (“treating or preventing macrocytic-megaloblastic anemia”) should be considered a limitation on the claim. The Federal Circuit found that the intent language was indeed a limitation on the claim, and that the defendant fell outside the scope of the claims because it sold an over-the-counter product without any intent to treat or prevent anemia.

          • Effect Of Prosecution History On Preamble Interpretation

Of course interpretation of a preamble can be significantly affected by the prosecution history. Clear reliance on the preamble during prosecution of a patent to distinguish the claimed invention from the prior art can be a strong indication that the preamble is a claim limitation. In the “broccoli“ case, for example, the Federal Circuit considered three patents related to growing and eating sprouts to reduce the level of carcinogens in animals. The relevant claims included:


In interpreting those claims the Federal Circuit found that the preambles did constitute limitation on the scope of the claims, largely based upon the following language from the patent prosecution.

Claim 1 of the patent, for example, is directed to “[a] method of preparing a food product rich in glucosinolates… and harvesting sprouts prior to the 2-leaf stage, to form a food product comprising a plurality of sprouts”…. Although “rich in glucosinolates” is recited in the preamble of the claim, the pertinent case law holds that the preamble is given weight if it breathes life and meaning into the claim….

          • Strategic Use Of The Preamble

All of this provides ammunition to the drafter for controlling whether language in the preamble is to be interpreted as a limitation of the claim. Considering the following preamble of an apparatus claim:

If an applicant claims a new type of battery, then the new battery should be compared against previously known batteries. The fact that the inventor intends to use the new battery in a hearing aid is irrelevant. The usage only became relevant to patentability where the claim recites a structural element directed to that usage. For example, the attorney could include a limitation to flatness, because hearing aids use flat batteries.

But even there, the claim would read on all flat batteries, even if they were also used in other applications. If the person drafting the claims really wants to limit the scope to hearing aid batteries, he must either (a) identify some physical aspect of hearing aid batteries that distinguish them from other types of batteries or (b) claim a combination of battery and hearing aid. He could also format the claim as a method claim. The following claims would achieve those goals:

Of course, if the attorney definitely wants the language of the preamble to be read as limitations on the scope, he can always use a Jepson format. Jepson format allows a patentee to use the preamble to recite elements or steps of the claimed invention that are conventional or known. When Jepson format is employed, the claim preamble defines the context of the claimed invention, and also provides limitations as to the scope of that invention. The fact that the patentee has chosen the Jepson format of the claim evidences the intention to use the preamble to define, in part, the structural elements of his claimed invention.

      1. (3)Body Of A Claim
        1. (a)Colon/Semicolon Format

The trend in the last few decades has definitely been towards formatting patent claims in a colon/semicolon format. Thus, instead of writing the claim as a single paragraph:

one might write even this simple claim as follows:

The claim could also have been drafted without the colon/semicolon format (see below), without changing the meaning. Here, however, one needs to add a comma between “back” and “held”. Otherwise the claim could be read as the back being held together by magnets.

The main advantage of the colon/semicolon format is that it clearly delineates the different components (or steps), and clearly distinguishes between main components and subcomponents. This is somewhat less important for patent practitioners who are used to parsing complex wordings. But when it comes to the courtroom, formatted claims can make a huge difference to the judge and jury. Clear formatting is even a help to patent drafters because it helps them logically write dependent claims, and support the claims in the Specification.

When using colon/semicolon format be sure to include the linker “and” after the last semicolon. Also be sure that the first letter of each “paragraph” remains lower case. Note too that it is possible to have layers of colon/ semicolon formats. Thus, it is entirely proper to recite:

        1. (b) Selecting Elements To Include In The claims

Regardless of how it is structured, the body of a claim contains all or most of the elements that serve to distinguish the claimed invention over the prior art. Indeed, one of the main goals of patent drafting is to write claims that circumvent the prior art. The secret is to mentally identify four or five elements of the “invention”, and then determine which of those elements are absent from each of references in the prior art. The body of the claim should then list the smallest subset of missing elements. In the text below, this principle is first described on an abstract level, and then discussed with the aid of two specific examples, one to a self-evolving marketplace and the other to an internal combustion engine.

On the most abstract level a circumstance might arise in which the invention has five aspects to it, A, B, C, D, and E, and there are three references of concern, R1, R2, and R3, disclosing the following:

R1 discloses A, B;

R2 discloses A, C, and D and

R3 discloses A, B, and D.

It should be immediately apparent that the narrowest possible claim would recite the combination A/B/C/D/E. But there is no need to limit the claim to such an extent. The combinations A/B/D, A/B/E, or A/C/E, are all also viable, and considerably broader than A/B/C/D/E because they contain fewer elements. Indeed the cleanest and broadest claim would simply recite the limitation E, all by itself. This may seem counter-intuitive to some people, but the fact is that the shorter the claim the broader it generally is. Anyone can draft long-winded, narrow claims with lots of elements. The trick is to draft very short claims that still manage to circumvent the prior art, and still be commercially worthwhile.

If in our example another reference, R4, comes to light that discloses A, B and E, the reader should immediately realize that there are still all sorts of viable combinations to consider, including A/B/C/E and A/B/D/E. But here again there are simpler combinations that are probably more desirable, namely C/E, D/E and C/D/E. Those more complicated combinations should probably be included in the patent application as dependent claims.

Of course the analysis is a bit more complicated than that presented so far. A good patents drafter also considers possible obviousness rejections that could be made by the patent office, i.e., which references can be fairly combined together. In our abstract example it might be that R1, R3 and R4 could be fairly combined. That reduces our analytical set to the following:

R1/R3/R4 combination discloses A, B, D, and E

R2 discloses A, C, and D.

Under that scenario the broadest viable combination is likely to be B/E. Now it is true that many patent attorneys and agents are able to make up these combinations in their heads, without recourse to pencil and paper. But beginning patents drafters dealing with all matters, and advanced attorneys and agents dealing with especially complicated matters, would do well to map all this out on paper, or on computer.

      1. (4)Self-Evolving Marketplace Example

U.S. 6035294 (Mar 2000) “Wide access databases and database systems” teaches a self-evolving generic for storing marketplace information. Information is stored as parameter/value pairs, such as make/Mercedes, model/S500, color/red, year/2003, and so forth. The system is designed to evolve from the bottom up, by allowing users to add new parameters, values and possibly new classifications for use in describing items for sale. When subsequent users add their own items, or search for previously added items, they are presented with parameters and values listed according to frequency of previous use. In that manner the most commonly used terms will float to the top, while the infrequently used terms will sink to the bottom, and eventually be dropped altogether. From that description one can surmise that the available elements from which to draft a patent claim include the following:

A-storing marketplace information

B – multiple types of items

C – in a database

D – display of item classifications

E – display of frequency of usage of item


F – interface to add new item classification

G – display of parameters

H – display of frequency of usage of parameters

I – interface to add new parameter

J – display of values

K – display of frequency of usage of values

L – interface to add new value

M – nature of item classification (hierarchical, flat,

overlapping, etc)

The prior art includes (a) artificial intelligence and expert systems that store data using an ever evolving collection of parameter/value pairs, and (b) US5799151 which teaches an interactive trade network that indexes products using parameter/value pairs. Given that prior art, what is the minimum set of elements needed to recite an allowable claim? The inventor probably needed element D (display of item classifications) to circumvent artificial intelligence and expert systems, and probably also at least some recitation of parameters (element G) and values (element J) so that the claim makes sense. The inventor also needed to recite a mechanism by which a user could add a new item classification, parameter, or value. Including all three of those in the broadest claim is probably unnecessary, so the question is which one or two should be included. An interface to add values probably adds no patentable distinction because there are many systems in which users add dollar amounts, colors, years, and other values. Similarly, an interface to add classifications is a poor choice because it is entirely possible (and even desirable) to prevent users from altering the classification scheme. This leaves an interface to add parameters (element I) as the critical element.

The broadest possible claim is therefore one that recites little more than elements D, G, I, and J, along with an appropriate preamble. Indeed, Claim 1 of the ‘294 patent properly reads:

The other elements are then properly included in various dependent claims. For example, display of classification usage information (element E) is recited in dependent claim 2, and display of parameter usage information (element H) is recited in dependent claim 3. The hierarchical aspect of the classification scheme (element M) is recited in claim 4, and display of value usage information (element K) is recited in claim 5.

      1. (5)Internal Combustion Engine Example

US5482015 describes an internal combustion engine that has the energy density of a two-stroke engine, but fuel efficiency and reduced pollution at least that of a four-stroke engine. These characteristics are accomplished by carrying the crank pin on a planetary gear such that the crank pin traces out a substantially triangular or other path having a relatively long flattened portion. The net effect is four strokes during a single turn of the crankshaft, with long power and exhaust strokes, but shortened intake and compression strokes. The prior art includes U.S. 5245962 teaching variable length connecting rods, US5170757 teaching an engine with traveling gears, and US5158047 that teaches linkages that decrease the piston velocity during the first half of the power stroke. Given that information, a patents drafter would want to address the following elements in the claims:

A – a combustion chamber

B – a reciprocating piston

C – fuel

D – a first gear carrying a crank pin

E – a planetary gear traveling around the first gear

F – the crank pin tracing out specific paths

triangular, quadrilateral and pentagonal, etc)

G – the crank pin tracing out a path having a

flattened portion

H – a motor vehicle or other application in which

the engine is used

The combustion chamber (element A), the reciprocating piston (element B), and the fuel (element C), are all necessary to run the engine, but they are completely commonplace, and add no patentable distinction to the claim. Those elements could be included in the preamble, but are best omitted from the broadest claim as being unnecessary. Circumvention of the prior art does, however, require that the crank pin trace out particular paths, and the only paths that accomplish the desired functions are triangular, quadrilateral and pentagonal paths (element F). The only practical way to accomplish those paths is to provide a first gear carrying a crank pin (element D) and a planetary gear traveling around the first gear (element E). Thus, the minimal set of elements that should be recited in the broadest claim consists of elements E, D, and F. Indeed, that is exactly what was claimed:

Use of the novel crankshaft arrangement in a compound crankshaft, an internal combustion engine, or a motorized vehicle (element H) is recited in dependent claim 2. The flattened path of the crank pin (element G) is recited in dependent claim 3. Other narrower combinations of the various elements are included in independent claims 5 and 6.

    1. D)Claiming Multiple Instances Of An Object

It is often necessary to describe multiple instances of a given component. For example, a bridge may have two cables, or a new type of engine may have 12 cylinders. But avoid getting tongue-tied describing all those different instances.

The best way to do this is to simply claim one instance of the component. If a new type of chair has legs made from some special type of plastic, don’t waste energy describing the number of legs. Simply recite “… a chair having a leg comprising <<the new type of plastic>>“.

For years the rule has been that one could (and should) use the simple term “a” rather than “at least one”. For example, a claim reciting “a chair having a leg and <<other components>>“ is identical in scope to “a chair having at least one leg and <<other components>>“, but the former has the advantage of avoiding the terribly stilted language “the chair of claim 1 wherein the at least one leg… “ in a dependent claim. Amazingly, this rule is now subject to dispute in view of a recent Federal Circuit decision limiting the term “a sodium phosphate” to a single type of sodium phosphate. The Court advised that if the patentee had intended to cover multiple types of sodium phosphate, it should have used “at least one” language. Hopefully, the decision will be limited to the special circumstances of the facts in that case, where: (1) the claim had been amended to recite “consisting of” rather than the open ended “comprising;” and (2) the specification was entirely silent as to examples of multiple types of sodium phosphate.

Where there are two or more instances of the component, one can often still get away with the indefinite term “a”, by reciting only one of the components. Thus, one can refer to only a single of the legs of a chair. Similarly, in a claim for an airplane having a new type of wing, the proper claim is to “an airplane having a wing <<with the new feature>>“. There is no need to recite “an airplane having two wings, each of the wings having <<the new feature>>“.

Where one does need to claim a plurality of instances of a component, it is acceptable to say “at least two”, “at least three”, “at least four”, etc. It is also acceptable to say “a plurality of”, which means the same thing as “at least two” and “more than one”.

It is often useful to name the instances by number. Thus, a patents drafter could recite “a chair having a first leg and a second leg <<having some special relationship to the first leg>>“. Details about the first leg would typically be recited in the independent claim, and then details about the second leg would be recited in a dependent claim.

Although it should not be necessary from a patent law perspective, it is easier for clients to understand what is being claims if the practitioner recites “at least” when referring to “first”, “second”, “third” etc components. “At least a first leg and a second leg” makes is abundantly clear that there are at least two legs, but that there can also be more than two legs.

Note that for terms such as “first” and “second”, the usual interpretation is that the terms give no indication of temporal order or position. Thus, in a claim to a chair having “a first leg and a second leg”, the first and second legs can be attached or produced in any order, and in any positions with respect to one another. The first leg, for example, might well be in the front or the back of the chair.

It may even be the case that the “first” and “second” items are the same thing! Consider the following two claims in U.S. 6683924 (Jan. 2004) “Apparatus and methods for selective correlation timing in rake receivers”:

In claim 1 there is no limitation as to whether the first and second signals are the same signal, so that claim covers both possibilities. The dependent second claim is expressly limited to situations where the first and second signals are the same signal.

Where there are potentially many instances, it is proper to refer to a “first” instance and a “second” instance. One can also refer to a “first” and “another”. See U.S. 6402762 (June 2002) “System for translation of electromagnetic and optical localization systems”.


Of course, this language is still not as clean as it could be. The drafter should have recited “an additional patient space” rather than “at least one additional patient space”, and “an additional surgical navigation system” rather than “at least one additional surgical navigation system”.

    1. E)Antecedent Basis

Patent attorneys and agents may be unique in the degree to which they focus on the definite and indefinite articles “the” and “a”. If someone asks whether I want to go to “the movies”, the patent attorney in me is resistant to answering the question because I don’t know which movie they are talking about. Unless there is only a single movie in town, a better phrasing of the question would be whether I want to go to “a movie”. Although annoying in social circumstances, and irritating to opponents in deposition situations, that usage comes from years of drafting patent applications.

The rule in patent applications is that the definite term “the” should not be used with respect to an element until the indefinite term “a” is previously used in the same claim, or in a parent claim. The error is called absence or lack of “antecedent basis“. This is readily appreciated with a few examples.

  • It is improper to say, “A shoe wherein the body is removably attached to the sole”. There is no antecedent basis for “the body” and “the sole”. One could, however, properly recite: “A shoe having a sole and a body, wherein the body is removably attached to the sole”
  • It would also be wrong to recite, “A shoe having a sole and a body, wherein the sole comprises the same material as the body….” The reason is that there is no antecedent basis for “the same material”. The correct phrasing would be “A shoe having a sole and a body, each comprising a material…”. The claim would even be more clearly worded as, “A shoe having a sole comprising a first material, and a body comprising the first material”.

Of course, other areas of law also focus on distinctions between definite and indefinite articles. “[I]t is a rule of law well established that the definite article ‘the’ particularizes the subject which it precedes. [“the”] is a word of limitation as opposed to the indefinite or generalizing force of ‘a’ or ‘an’”. Patent attorneys and agents just focus on the distinction more than most other people do.

Although the rule requiring antecedent basis is rigorously enforced by the examiners, there are instances in which claims slip through with violations. In federal court, such claims may be deemed invalid for indefiniteness, but only where the defect is “severe”. In the Fisher-Price v. Graco case the defendant argued that claim 6 was invalid for indefiniteness because it lacked an antecedent basis for “said seating area”.


The Federal Circuit disagreed, noting, “[a] claim is not invalid for indefiniteness if its antecedent basis is present by implication. [citations omitted] It is our conclusion that, in this case, ‘upper seating surface’ is by implication the antecedent basis for ‘seating area.’ On that basis, we hold that the second half of the shield limitation of claim 6 is not indefinite.

Other cases reach the same conclusion. In Energizer Holdings v. ITC, the Federal Circuit held that lack of antecedent basis for the term “said zinc anode” did not render the claim in which they were recited “insolubly ambiguous” and therefore invalid for indefiniteness. The Energizer case reiterated the more general principle, “We have held that a claim is not indefinite merely because it poses a difficult issue of claim construction; if the claim is subject to construction, i.e., it is not insolubly ambiguous, it is not invalid for indefiniteness”.

Who knows if these cases would be decided the same way after the Nautilus case?  Nautilus raised the standard for determining whether claim language is sufficiently definite.  The prior standard was whether it was “possible” for a court to construe the claim language. The new test is whether the claims “clearly indicate” to a competitor what is the scope of the claim.

Rigorous attention to antecedent basis can give rise to extremely awkward wording, especially when there is a need to recite “at least one” of a particular element. For example, a patents drafter attorney might claim “an electronic circuit containing at least one transistor operatively coupled to <<some other components>>. Later in the claim, he would then need to refer to “the at least one transistor” to clearly designate that the item being referred to falls within the class the “at least one transistor”.

    1. F)Claiming Numbers And Ranges
      1. (1)Precision And Accuracy 

Precision and accuracy are two different things. Precision describes the number of digits that are used to express a value, whereas accuracy describes the extent to which a representation is true. For example, if the true temperature of a liquid is exactly 40°C, it would be more precise to say 40.000°C than to say 40°C, but both would be accurate.

In patent law, numbers are usually considered to be approximations, with the amount of wiggle-room governed by the degree of precision. For example, a claimed alkalinity of pH 10 is usually taken to include a range of 9.5 to 10.5, while a claimed alkalinity of pH 10 is usually taken to include a range of only 9.95 to 10.05. Of course the same applies to units of length, weight, and so forth.

On the other hand, it is understood that only realistic subsets of the permutations are contemplated. For example, US4851058, claim 1 recites:

Obviously, it is impossible for all of the components to be present at the upper ends of the specified ranges, i.e., 40% neodymium, 90% iron, and 10 percent boron.

To avoid confusion, our office currently adds language along the following lines when drafting specifications:

      1. (2)Endpoints

Claiming ranges of values presents special problems and opportunities. The most common problem is probably failure to focus on the endpoints of a range. A claim reciting “a temperature from 35 – 45 degrees centigrade” is indefinite unless the attorney specifies whether the endpoints 35° and 45° fall within the range. The better language is to state “a temperature from 35 – 45 degrees centigrade, inclusive”. Some attorneys finesse the issue by clarifying in the specification that “unless the meaning is clearly to the contrary, all ranges set forth herein are deemed to be inclusive of the endpoints”.

Another problem is that prior art as to any portion of a range can invalidate an entire range.

An article of manufacture comprising a hydrogel bound to a substrate… comprising: at least one polymer derived from 1 to 99 parts by weight of at least one azlactone-functional monomer and 0 to 99 parts by weight of at least one co-monomer….

In the examples above, the patent office would consider the writer to have suggested all combinations covering the entirety of both ranges (azlactone-functional monomer and co-monomer), even though the inventor may have only consciously contemplated less than 1% of those combinations. As long as the combinations are enabled, (i.e., one of ordinary skill in the art would know how to make and use them by employing at most a reasonable amount of experimentation), all of those combinations are treated as prior art and generally preclude a later inventor from claiming any subset of those combinations. The Federal Circuit has even found obviousness where the prior art merely abutted a previously disclosed range, or were so close to the claimed embodiment that one skilled in the art would have expected them to have the same properties.

      1. (3)Claiming Inside A Previously Disclosed Range

There are two exceptions to the general rule that a patents drafter cannot claim inside a previously known range. First, it is possible to receive a patent on a subset of a previously disclosed range on the grounds that the subset has an “unexpected result“. The applicant must show that the result would have been surprising to a person of ordinary skill in a particular art, and usually only applies to the “less predictable fields” such as chemistry, where minor changes in a product or process may yield substantially different results.

The other theoretically valid exception to the rule is that the reference expressly teaches away from the claimed range. Unfortunately, the only case law directly on point appears to be in a dissent.

      1. (4)“About”

The term “about” raises yet another issue with respect to claiming ranges. Should a patents drafter say “about 1-3% chromium” or should he simply say “1-3% chromium”? The answer is that it is probably better to use the qualifier. Both terms should be construed to include slight variations on the specified range, but the former includes those variations within the literal scope of the claim whereas the latter includes those variations (less desirably) only through the doctrine of equivalents.

Although some examiners continue to reject claims containing the term “about” as being indefinite, they are wrong in doing so. Use of the term “about” is entirely acceptable, and should be according its ordinary meaning of “approximately”. See Merck & Co. v. Teva Pharms. USA, Inc., “We reverse the District Court’s construction of “about” and hold that such term should be given its ordinary meaning of “approximately”. See also In re Harris, “Application’s use of the term ‘about’ shows that the applicants did not intend to limit the claimed ranges to their exact end-points” and Jeneric/Pentron, Inc., which held that failure to use term “about” limits numeric statements to the exact number recited.

One should, however, be cognizant of what is being qualified by the term “about”. In 2005 a District Court construed “about 70 mg of alendronate monosodium trihydrate” to mean “exactly 70 mg of alendronic acid when taking into account molecular weight variances for its derivatives that carry accessories”. The claim language was as follows:

The Federal Circuit did eventually overrule the District Court on that point, and thereby completely changed the outcome of the case. But the Court acknowledged that it was a close call.

      1. (5)Claiming Averages

Claiming averages poses significant traps for the unwary. For example, in litigation regarding U.S. Patents No. 6066861 the Federal Circuit considered a patent claiming inter alia “pigments having grain sizes ≤ 20 µm and a mean grain diameter d[50] ≤ 5 µm. The appeal focused on whether the mean grain diameter should be calculated on a number-based average (average diameter) or a volume basis (diameter of grain with average volume). The analysis is complicated by the fact that the claimed d50 term generally indicates a median – not a mean. The majority chose the number based diameter calculation, although there was a vigorous dissent by Judge Dyk. The lesson here is that if you do recite averages in your claims, you should specify how those averages are to be calculated.

    1. G)Special Types Of Claims
      1. (1)Structure Versus Method Claims

There are basically only two types of subject matters that can be claimed, things and processes (i.e., methods). Claims to things are variously called device, apparatus, composition, structure, and system claims depending on the nature of what is being claimed. A sample structure claim is as follows:

Claims to processes are called process or method claims. A sample method claim corresponding to the structure claim is as follows:

Each type of claim has its advantages and disadvantages. Structure claims are often extremely useful because they deal with recognizable physical objects such as housings, rings, ball bearings, levers, joists, motors, polymers, chemical elements, and so forth. It is therefore relatively easy for a judge or jury to determine infringement. Moreover, a structure claim is infringed as long as the accused product contains the claimed physical elements. Any purpose of the device, and any intention of the user, are generally irrelevant to interpreting either the scope of the claim or infringement. Structure claims are less useful when the structure cannot be determined. For example, computer chips are practically impossible to reverse engineer with current technology. That works well for keeping a chip design as a trade secret, but is likely far less useful when it comes time to accuse someone of patent infringement. The patent holder bears the burden of proving infringement, and it may be impossible to examine an allegedly infringing chip at a sufficient level of detail to ascertain whether the product contains the claimed structure.

Method claims are especially useful where the invention is mostly a process rather than a finished product. In U.S. 6548559 (April 2003) “Thermoplastic compositions and methods”, for example, the inventor claimed the following:

There, a major part of the invention was the order in which the ingredients were mixed. It would have been near impossible to claim the end product because another patent, 5114648 (May 1992), had previously taught using the same ingredients to make the same product. Method claims are also useful for claiming use of a product, such as using a drug to treat a new disease, or using a circular saw blade to cut into wet concrete.

Some attorneys like method claims because they are fairly easy to draft. But method claims can be problematic to enforce. After all, how can a jury decide on infringement as to some imported product if there is no testimony as to the way it was manufactured? Or how can a patent holder sue the thousands of individuals for use of a tool that has other, non-infringing uses. Unless the accused infringer is actively inducing infringement, the patent holder will have a hard time prevailing in court.

There is a loophole with respect to method claims that redounds to the advantage of foreign competitors. In a 2005 case the Federal Circuit held that “a process cannot be used ‘within’ the United States as required by section 271(a) unless each of the steps is performed within this country”.

“Ordinarily, whether an infringing activity under section 271(a) occurs within the United States can be determined without difficulty. This case presents an added degree of complexity, however, in that: (1) the “patented invention” is not one single device, but rather a system comprising multiple distinct components or a method with multiple distinct steps; and (2) the nature of those components or steps permits their function and use to be separated from their physical location.

The use of a claimed system under section 271(a) is the place at which the system as a whole is put into service, i.e., the place where control of the system is exercised and beneficial use of the system obtained. See Decca, 544 F.2d at 1083. Based on this interpretation of section 271(a), it was proper for the jury to have found that use of [the alleged infringer’s] asserted system claims occurred within the United States.”

(emphasis added). Many attorneys think there is something to be gained by claiming the same subject matter as both a method and an apparatus. It certainly adds to the number of claims, and raises the total cost of prosecution. The reality is, however, that there is no per se nonobvious distinction between a method of using a device and the device itself. Thus, claim 1 in US5562925

is “not patentably distinct” from claim 1 in U.S. 4339437, despite the inclusion of the new term “suitable for therapeutic administration by injection in solution”.

      1. (2)Means-Plus-Function Claims

In 1946 the U.S. Supreme Court struck down a patent claim that recited an invention using purely functional language. In response, Congress added a new section to the patent law, which expressly authorized claims to describe physical elements as a “means” for accomplishing some task. Claims that include one or more such means-plus-function elements are called means-plus-function claims. Here’s an example.

Means-plus-function claims were very popular until the early 1990s. The idea was that a clever patent drafter could claim an apparatus without expressly limiting the elements by a particular structure. Thus, a doorknob could be broadly claimed as a “means for opening a door”, and a bottle could be broadly claimed as a “means for carrying a substance”.


The problem, of course, is that the essence of a structure claim (apparatus/device/composition/ software) is that it defines structure, and means-plus-function claims circumvent structural limitations precisely because they define elements by their function.

Congress resolved that problem by limiting the scope of means-plus-function claims to the embodiments actually disclosed in the specification and drawing, and structural equivalents thereof. For example, if a claim recites “means for opening a door” and the only such means disclosed in the application was a doorknob, the “means” would only include the disclosed doorknob and more or less exact structural equivalents. “means for opening a door” would therefore very likely exclude a latch type opener.

My recommendation is to avoid means-plus-function claims. The scope of equivalents accorded a means-plus-function element is narrower than the scope afforded other elements under the doctrine of equivalents, and it is usually trivial to revise a draft claim to eliminate the means-plus-function language. There is even a risk that failing to clearly link the structure disclosed in the specification with the function recited in the claim can invalidate the claim for failure of the written description. “The duty to link or associate structure in the specification with the function is the quid pro quo for the convenience of employing 35 U.S.C. § 112, para. 6”.

Our office almost never uses means-plus-function claims, and the practice of others is finally falling into line. In most of the 1980s about 45% of patents contained at least one means-plus-function claim, but according to research done by Patently-O, that number had dropped to only about 6% by 2013, despite a large increase in the average number of claims per patent.

There are still adherents of means-plus-function claims, even among practicing patent attorneys and agents. One argument is that the Festo line of cases has all but eliminated the doctrine of equivalents for elements in claims that have been narrowed during prosecution. Since means-plus-function elements are interpreted under 35 U.S.C. § 112 paragraph 6 rather than the doctrine of equivalents, they might escape from the Festo limitations. Interesting idea, but it doesn’t fly. First, the rationale behind the Festo limitations applies just as well to means-plus-function language as to structural language. Second, means-plus-function language unnecessarily narrows the claims. Any element that can be drafted using means-plus-function language can be better drafted using structural language.

Another possible rationale is to use means-plus-function (or step-plus-function) language to narrow the scope sufficiently to avoid §101 invalidity under Alice and its progeny.  The idea is that the claimed subject matter might be found eligible because the claims must be interpreted in a manner that doesn’t “preempt the field”. That seems to be a valid argument, although failure to preempt the field does not necessarily render the subject matter patent eligible.

There are other, even more obscure rationales for using means-plus-function language. For example, use of means-plus-function language may preclude an interference proceeding, even where the junior applicant copies the claims of the senior applicant verbatim in an effort to trigger an interference. Since the scope of the claims is limited to equivalents of that disclosed in the specification vis-à-vis the means-plus-function terms, claims of different specifications would be according different scopes even though they have identical claims.

In the past, use of a term other than “means” would typically not implicate means-plus-function interpretation under 35 U.S.C. § 112(6).  However, in the last few years patent practitioners have become so adept at using nonse words, that the courts have gotten to the point where almost any language that fails to indicate structure is interpreted as a mean-plus-function term.

Moreover, almost any use of the term “means” will result in the term being construed as a means-plus-function element. In Cross Med. Prods., Inc. v. Medtronic Sofamor Danek, Inc., the Federal Circuit held that correlation of means-plus-function language with a specific physical structure, as in “securing means … i.e. a nut” is insufficient to disavow the § 112 ¶ 6 equivalents.Step-Plus-Function Claims

Step-plus-function claims are simply the method equivalents of means-plus-function apparatus claims. They suffer from all the same drawbacks, and have all the same (tenuous) advantages. The signal for implicating 35 U.S.C. § 112(6) is, however, just a bit subtler. Use of the common method language “comprising the steps of” does not implicate 35 U.S.C. § 112(6), but use of the term “step for” does.

      1. (3)Product-By-Process Claims

Product-by-process claims are intended to protect a final product without having to recite the structure of what is being protected. Such claims are appropriate when an inventor knows that he processed starting materials in various ways to wind up with a useful product, but doesn’t really know what the product is. All he has to do is recite (a) the starting materials, and (b) the process by which those materials are combined. For example, US5670671 recites:

Although product-by-process claims are almost always chemical inventions, it is possible to write a product-by-process claim for a physical device. US6047711 (April 2000) “Method and apparatus for converting a power-driven toothbrush into a power-driven flossing device” claims an electric powered tooth-flossing device made by converting an electric toothbrush to vibrate floss rather than bristles. The attorney who drafted this claim was actually quite clever in using the product-by-process format, since a claim directed to the end device would very likely have been precluded by the prior art. On the other hand, the attorney made other mistakes that render the claim either worthless or nearly so. Among other things he used means-plus- function language (which should have gone the way of the great auk years ago), and he included all sorts of unnecessary limitations, such as the yoke having free ends configured to interact with an anomaly in the floss.

Here is another example, this time in the field of data processing (US6089742 July 2000):

Product-by-process claims should be used sparingly. The chief downside is that a competitor can often circumvent the claims by reverse engineering the product, and then using a different method to manufacture the product. Since the claims hinge upon a method of production, the competitor would escape infringement. “[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process”. If an inventor does need to file a product-by-process claim, it is probably advisable to follow up with the filing of a structure patent as soon as he determines the chemical or physical structure of the product.

One must also be careful to avoid inadvertently transforming an ordinary claim into a product-by-process claims during prosecution. In an unpublished case, the Federal Circuit held that the following claim had been transformed into a product-by-process claim during prosecution.

The cause of the transformation was merely the addition of the italicized language in response to a question as to how the stud ‘aligned’ with the vertical slot. One could have said:

Still another oddity of product-by-process claims is that the process recited in a product-by-process claim limits the scope of the claim for purposes of validity and infringement, but not for patentability. Thus, the claim is both harder to get and narrower than one might expect.

      1. (4)Markush Groups

Markush groups are simply listings of alternative elements in a peculiar format. The practice began years ago when the patent offices were much stricter than they are today about refusing to allow the disjunctive term “or” in a claim. If someone claimed a chair, for example, he might well want to specify that the chair could be held together “with nails, screws, bolts, dowels, or glue”. But claiming the alternatives in that way uses the term “or”, which risks rendering the claim indefinite. After all, which of the connectors is being claimed? Markush groups solved that problem by using a stilted format relying exclusively on the injunctive term “and”. The chair would be claimed as being held together with “at least one of a nail, a screw, a bolt, a dowel, and glue”.

The elements grouped in a Markush claim can be almost anything, from chemical compounds (Jan 2002):

to information processing (6892316 May 2005):


to methods of doing business (6892145 May 2005):

More recently the various patent offices are much more receptive to use of the term “or” in the claims. The practice seems to have begun with chemical composition claims that recited R groups in the alternative (…where R1 is H, OH, lower alkyl, lower alkane, methoxy, or ethoxy…), and then expanded to other fields. We still tend to use Markush claiming though, because it is technically more correct, and some day the courts could again determine that claims using “or” are indefinite.

If one is going to use a Markush group, one should at least use it correctly. The proper wording has the format “a __ consisting of the group selected from the list consisting of __, __, __ and __”. Note that one should use the exact phrase “selected from the group consisting of”. Second, the final connecting word is the injunctive “and” rather than the disjunctive “or”. That may seem strange to some, but it actually makes sense. A list consists of elements a, b, c, d, and e, not a, b, c, d, or e”.

      1. (5)The following is improper because the Markush groups to claim entirely different inventions.
      2. (6) Jepson Claims

The Jepson format allows a patentee to use the preamble to recite “elements or steps of the claimed invention which are conventional or known”. “When this format is employed, the claim preamble defines not only the context of the claimed invention, but also its scope”.

Jepson claims  have the general format of a rather lengthy preamble, “A <<device or method>> having <<elements A, B, C, and D>>, wherein the improvement comprises:”, followed by a listing of the novel element(s). The following claim from US6877612 (April 2005) “Filter cartridge for use in severe environments” is a Jepson claim, in which the entire portion preceding “wherein the improvement comprises” constitutes the preamble.

Note that it is also possible to achieve the same effect as a Jepson claim, without expressly using the Jepson format. Claim 1 of US6898670 (May 2005) places numerous elements of the prior art in the preamble, but omits the Jepson language, “wherein the improvement comprises”:

Jepson claim format is sometimes used when the invention is only a minor part of something that is already in the prior art, and the person drafting the claims wants to very clearly separate out what is old in the field from what is novel. The format is often a good one, and seems to be appreciated by busy patent examiners. One very strong benefit is that use of Jepson claims forces the patent drafter to figure out just what is the improvement over the prior art. Jepson claims are also relatively easy for jurors and courts to understand during litigation.

The downside, of course, is that when the improvement is so very clearly set forth, its narrowness or invalidity over the prior art may become all too evident. There is also a very real danger in listing too many things in the preamble. The U.S. patent office and several court opinions take the position that the combination of elements set forth in the preamble of a Jepson claim is necessarily old, i.e. recitation of elements in the preamble of a Jepson claim constitutes an implied admission that the combination of those elements is within the prior art. That is mostly true, but not always.

One serious drawback to the Jepson format is that filing of the claim can be regarded as an implied admission that subject matter in preamble is prior art work of another!!!  Even if the Jepson claim is thereafter canceled, the admission can remain.

Fortunately, not all Jepson claims are deemed to constitute implied admissions. In In re Ehrreich the examiner considered material from the preamble of a Jepson claim as prior art when making an obviousness rejection. The Ehrreich court found that rather than making an admission about the scope and content of the prior art, the applicant used Jepson language to avoid a double patenting rejection in the applicant’s co-pending application. That co-pending application was not available to the public, was not the work of another, and was therefore not prior art under any statutory provision. The court concluded: “We think that a finding of obviousness should not be based on an implied admission erroneously creating imaginary prior art. That is not the intent of § 103.

    1. H)Claiming Results Rather Than Structure

A clever patents drafter can sometimes find a way of claiming a result without using either means-plus-function language or product-by-process claims. The following claim was allowed by the PCT examining authority, but never issued.

In that example the applicant recites a minimal amount of structure — just enough to justify claiming the desired results of hardness, flexibility, and so forth.  But one needs to be extra careful with this type of claiming.  Patent examiners regularly (and correctly) reject claims that recite results in lieu of structure or specific steps.

    1. I)Claiming Negatives

It is generally a very bad idea to use the term “not” in a patent claim. The problem is that the term “not” shines as a bright beacon to guide a competitor towards non-infringement. In the claim below, for example, the claim all but tells a competitor to build a non-infringing lamp by including a power source that can be connected to a wall outlet.

A much better wording for the claim is as follows:

Despite the caveat against using the term “not” in a restrictive sense, it can still be quite advantageous to use the term in an expansive sense. In the following example, the term “not” actually expands the scope of the claim:

Even so, it’s probably best to omit the term “not” in favor of other wording such as “other than”.

    1. J)Special Considerations For Method Claims
      1. (1)Software and Business Method Claims

The patent system is forever trying to balance contributions to technology against benefits (rewards) to patentees. And patent practitioners have forever been trying to game the system by drafting claims that cover more ground than is justified by the contribution.

Until the late ’90s,  patent practitioners often tried to game the system by drafting claims in means-plus-function format.  For example, instead of claiming a door knob having various inventive features, a practitioner might recite a “means for opening a door”.  The idea was to include within the scope of the claims, all possible combinations of the inventive features with door knobs, latches, and any other “means” that satisfies the function of opening a door. Of course, that strategy seriously upset the balance of contribution vs scope of claim, and was squelched by Congress with passage of 35 U.S.C. 112(6), (now 35 U.S.C. 112(f)).

Undeterred, patent practitioners have more recently come to rely on nonce words, words such as “component”, “device”, “module” and “member” that sound structural, but basically impart no significant structural limitations to the claims. That strategy still upsets the balance of contribution vs reward, and will often trigger a rejection from the examiner.  See MPEP § 2181. In addition, the practice has finally started to be seriously curtailed by the Federal Circuit.  See for example, Williamson v. Citrix et al. addresses interpretation of the language “a distributed learning control module for receiving communications….” The trial court found the claim to be valid by construing the term “control module” to include extraneous limitations related to “a graphical display representative of the classroom”. The Federal Circuit, however, construed “distributed learning control module” as being a § 112, ¶ 6 [now § 112(f)] means-plus-function element.

Some practitioners have also tried to game the system by prosecuting claims that go way beyond the scope of the disclosure in the specification and drawing. Interesting strategy, but one that usually doesn’t usually work because of the written description and enablement requirements. See for example, Inphi Corp. v. Netlist, Inc, and other cases dating back to 1989, and Univ. of Rochester v. G.D. Searle & Co.

Patent practitioners also try to game the system using method claims.  Because method claims are directed to steps rather than physical structure, they readily lend themselves to drafting claims that overly reward the patent holder.  Consider, for example, the invention in Mayo v. Prometheus, in which the claimed subject matter was a method of deciding upon a proper drug dosage, by administering the drug to a patient, and then using measurements of metabolites of the drug to either increase or decrease the dosage of the drug.  If those claims had been allowed to stand, the patent holder could have extracted royalties from virtually anyone trying to figure out how much drug to give to a patient — virtually any drug — any patient — for any condition.  Such claims were ridiculously broad relative to the inventors’ contribution to technology,

Another area ripe for abuse are claims reciting software or business methods.  Even if the subject matters are recited as system or apparatus claims, the elements of the claims basically involve some sort of hardware that is programmed to implement a set of steps. Since the only claimed structures are well-known electronics, even claims drafted as system or apparatus claims are effectively method claims.

In Alice, the Supreme Court apparently took all of these things into consideration, and basically held that subject matter eligibility doesn’t depend on how cleverly the patent drafter worded the claims, and whether the claims are apparatus or methods.  The Court instead effectively held that subject matter eligibility depends instead on whether the essence of the inventive, (the “inventive concept”) falls within one of the judicial exceptions, and if it does then whether the claims recite something significantly more.

Patent practitioners and the lower courts should not have been surprised. In Mayo the Court rationalized its holding of subject matter ineligibility in part by finding that “… the underlying functional concern here is a relative one: how much future innovation is foreclosed relative to the contribution of the inventor.” Similarly in Myriad, the Court advised “[p]atent protection strikes a delicate balance between creating ‘incentives that lead to creation, invention, and discovery’ and ‘imped[ing] the flow of information that might permit, indeed spur, invention.'”

And readers should remember that these were unanimous Supreme Court decisions!  So the real question is not how to circumvent these decisions, but how to live within them. It is no longer adequate to claim software or business methods (a) by reciting that the software resides on a non-transitory memory, (b) or by expressly reciting the speed or size of data set with which the electronics can execute the methods, (c) including in the elements a general purpose computer or processor, or (d) focusing on some user interface.  Those strategies each worked to some extent in the past, but going forward the courts will look through those smoke screens to find the “inventive concept”, and then consider whether there are sufficient limitations narrowing that concept to balance the contribution to technology against rewards to the patentee.

And yes, as many commentators have opined, to some extent this does involve conflating subject matter eligibility under § 101 with obviousness under § 103.  But this should not be viewed as an error on the part of the Court. Under current statutory law, obviousness is a dichotomy; either a claimed subject matter is obvious or it’s not.  There is no grey.  In the new world under Mayo, Myriad and Alice,  the court is viewing obviousness on a sliding scale, weighing the extent of contribution to technology (degree of obviousness), against the reward to the patentee.

What does this mean from a practical standpoint?  It means that when drafting the specification and claims for software or business methods inventions, or even for even chemical compositions extracted from nature, the key is to point out how the claims balance the contribution against the reward.

First, this means writing a strong Background description that clearly points out how numerous prior efforts have been unable to develop a good solution to whatever problem is being addressed.  Like a presentation from a good salesman, the emphasis should be on the difficulty of the problem, and the great need for a solution.

Second, this means writing the detailed description in a manner that points out viable alternatives that are not covered by the claims. Patent attorneys and agents are usually fairly good at describing both a preferred embodiment, and all sorts of alternative components, orientations, arrangements and so forth that will also work.  But rarely do they ever describe alternatives that fall outside the scope of the invention. That practice leaves the reader (competitor, judge, jury) to understand that the inventive subject matter is extremely broad, but doesn’t give a clear picture of the bounds of what was invented.

Third, this means writing claims having scope that is commensurate with the scope of the invention.  If the invention is narrow, in a crowded filed, then the corresponding claims should be narrow.  If the invention opens up a whole new area of technology (e.g., invention of solid state electronics, or lasers), then yes the claims should be drafted broadly.

All of this, of course, is counterintuitive to a great many inventors.  Their goal is to get the broadest possible patent claims, which is completely understandable in a competitive society such as ours.  But it doesn’t help the society, and indeed it often just puts money in the hands of the patent practitioners and litigators.

In the United States there are four independent categories of inventions or discoveries that are eligible for patent protection: (1) processes, (2) machines, (3) methods of manufacturing and (4) compositions of matter. Since at least 1981 the U.S. Supreme Court has interpreted those categories so  broadly that there are really only three categories of exceptions, i.e., subject matter that is not patentable under 35 USC § 101, “laws of nature, physical phenomena, and abstract ideas”.

      1. (2)Steps Of A Method Claim Are Not Necessarily Sequential

When someone other than a patent attorney or agent reads a method claim, he usually infers that the various recited steps are sequential. For example, in the following claim from 5114648 (May 1992), an ordinary reader might well assume that the listed steps are to be performed in the order listed.

Indeed, that was precisely the examiner’s argument in rejecting the following claim from a later application to very similar subject matter:

But the examiner was wrong. After several years of arguing, the examiner finally recognized that the earlier claim (and its accompanying disclosure) had no limitation as to order. The later claim did recite a particular order that the original inventor had never contemplated, and on that basis the examiner eventually allowed the claim.

Different patent drafters establish sequence in different ways. Perhaps the most common language for establishing sequence is to use the terms “then”, “next”, or “thereafter”.


      1. (3)Hybrid claims – Combining Method & Structure Limitations 

Patent claims are usually either (a) method claims that are primarily directed to steps in a process, or (b) structure claims that are primarily directed to physical limitations such as chemical structures and components — but not both. The problem is that from time to time an invention is not well described by claims falling into these neat categories. Such inventions must be claimed using hybrid language that combines both method and structure limitations.

The simplest strategy is to claim an apparatus (or chemical structure, etc) in an independent claim, and then recite a method of using the apparatus (or chemical structure). This is often done with pharmaceuticals. In the following example from a withdrawn application, claim 1 recites a pharmaceutical substance, while claim 9 recites use of that substance to treat a disease.


Of course, the same technique can be applied to any field (6634134 Oct 2003):


Another strategy is to include a step limitation (method) in an otherwise structurally oriented claim. A classic reason to use this strategy is that the product being claimed is substantially indistinguishable from products in the prior art. Even though the real difference is how the product is manufactured, the applicant wants to claim the product rather than the process because product claims are much easier to enforce. Here’s a sample claim directed to a cured polymer.


In that particular case the applicant could have simply recited a cured polymer composition, but specifically chose to circumvent some of the prior art by claiming a photocurable composition that had been photocured.

But it should be noted that some hybrid claims might be declared invalid for indefiniteness. In a November 2005 case, the Federal Circuit held that various claims of’s one-click patent were anticipated by the prior art. And interpreting a matter of first impression, the Court further held that claim 25 was invalid for indefiniteness because it attempted to claim both a system and a metho

In particular, the Court held that claim 25 recited both “the system of claim 2” and a method by which “the user uses the input means…”. According to the Court, “it is unclear whether infringement of claim 25 occurs when one creates a system that allows the user to change the predicted transaction information or accept the displayed transaction, or whether infringement occurs when the user actually uses the input means to change transaction information or uses the input means to accept a displayed transaction”. In many ways, of course, the rule against hybrid claims set forth in the one-click patent case flies in the face of decades, if not centuries, of patent drafting. Until the rule is clarified by the Supreme Court, or by subsequent Federal Circuit decisions, a patent drafter might do best to avoid relying on hybrid claims.

    1. K)Design Patents

For several decades at the end of the last century, design patents had become less and less valuable due to the difficulty of establishing infringement. Among other things, the Courts used a complex test that involved both “point of novelty” and an “ordinary observer” perspective.

Beginning in 2008 with the Egyptian Goddess case, however, the test for design patent infringement was simplified to consist of a single inquiry: whether

“in the eye of an ordinary observer, giving such attention as a purchaser usually gives, [the] two designs are substantially the same”

(the “ordinary observer test”). In other words, infringement prevails whenever an ordinary observer, familiar with the prior art, would be deceived into thinking that the accused design was the same as the patented design.

Egyptian Goddess opened the floodgates to numerous high profile design patent infringement cases, including Apple’s™ establishing infringement over Samsung™ and others regarding cell phone design. And perhaps recognizing  the growing importance of design patents, congress followed up by enacting the Patent Law Treaties Implantation Act of 2012, which makes it easier to obtain design patents on shapes and other designs. Among other things, the law harmonizes U.S. practice with most of the rest of the world, increasing the design patent term from 14 to 15 years, and allowing applicants to seek many different design inventions with a single application.

But whether greater emphasis on design patents is a good idea remains to be seen. As the Apple litigations have shown, companies with lots of money can use the most minimal of design “inventions” (e.g. rounded corners on cell phones) to beat down their competition with questionable lawsuits filed in favorable jurisdictions. (Did anyone really expect a verdict against Apple in San Jose, California?)

The tests for determining validity and infringement of a design patent are supposed to be identical to those for a utility patent. This includes subject matter under 35 U.S.C. § 101, originality, statutory bars § 102, obviousness under § 103, and so forth. And of course a party challenging patent invalidity must establish invalidity by facts supported by clear and convincing evidence.

The problem, as with utility applications, is that Patent Office grants patents on designs that are mere design choices. A design patent § 103 analysis has only two steps. First, the court must identify a proper primary reference—i.e., a “something in existence” that has “basically the same” appearance as the claimed design. Second, other references can be used (assuming certain conditions are met) to modify the primary reference “to create a design that has the same overall visual appearance of the claimed design.” That test does nothing to weed out designs that add little or nothing to the world.

The 2013 decision in High Point Design LLC v. Buyers Direct, Inc., illustrates the problem. In that case the Federal Circuit overruled the district court’s finding that the claimed slippers were obvious over the prior art. Reproduced below are images of the prior art and patented slipper designs. Are do the differences in design really justify a patent

Figure 23 – Prior Art And Patented Slippers Design

Design patents are restricted to claiming ornamental (i.e. nonfunctional) aspects of things. The squiggles at the bottom of silverware, for example, have no function whatsoever except to be decorative. Thus, they would be protected using a design patent. The same goes for designs of sunglasses, automobiles, furniture, and so forth. Similarly, a design for an article of manufacture that is hidden in its end use and whose ornamental appearance is of no commercial concern prior to reaching its end use, lacks ornamentality and is not proper statutory subject matter. Subject matters that could be considered offensive to any race, religion, sex, ethnic group, or nationality are expressly precluded from patentability.

Many articles, of course, have both a distinctive ornamental appearance and utility, and in such instances they can be protected by both design and utility patents. Thus, the overall shape of a pair of sunglasses might have no functional benefit whatsoever, and therefore could be patented using a design patent. But the chemical composition or the coating of lenses would definitely be functional, and therefore could be patented using a utility patent. In many instances it is extremely difficult to tease out the utilitarian aspects from the ornamental aspects. With respect to sunglasses, for example, the shape of the lenses might be ornamental, functional, or both.

Design patents have only a single claim, which has substantially the same format for every design patent; “ The ornamental design for a _____, as shown”. When there is a properly included special description of the design in the specification, or a proper showing of modified forms of the design, or other descriptive matter has been included in the specification, the words “and described” should be added to the claim following the term “shown”, and the claim should read “The ornamental design for a ____ as shown and described”.

Design patents also have no specification to speak of, other than the descriptions of the various figures, so that the scope of the claim is determined almost entirely by the drawing. Elements that are considered to be part of the invention are shown in solid lines, and elements that are need to provide context, but are not deemed to be part of the invention, are shown in dotted or broken lines. Design patents are relatively easy to get issued, but usually not worth very much because they are too easy to circumvent. Since the scope of the protection is necessarily limited to ornamental appearance, a competitor need only adopt a different design to circumvent the patent.

A design patent and a product configuration trade dress type of trademark may be obtained on the same subject matter. The CCPA held that the underlying purpose and essence of patent rights are separate and distinct from those pertaining to trademarks, and that no right accruing from one is dependent or conditioned by the right concomitant to the other. It is also possible to secure a copyright registration on the same ornamental design as is protected by a design patent. In fact, the Patent Office permits the inclusion of a copyright notice in a design patent, provided inter alia that the applicant includes a waiver as follows:

A portion of the disclosure of this patent document contains material to which a claim for copyright is made. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but reserves all other copyright rights whatsoever.

Design patents have always had a place in a patent portfolio for companies such as Oakley™, whose sunglass product lines rely heavily upon ornamental appearance. In light of the recent litigation, it appears that many others can benefit as well – at least until the pendulum swings back.