Writing patent claims

A patent claim is like a jigsaw puzzle piece
A patent claim is like a jigsaw puzzle piece

Writing patent claims is analogous to describing multidimensional jigsaw puzzle pieces using words.  Your claims have to fit in the spaces between prior art.

Patent claims are the most important part of a patent because the claims are legally enforceable.  Claims are also the trickiest part because they have to follow many rules.  Claims should describe your invention, not read on the prior art, and not be obvious variations on prior art. Claims should also be precise enough that others can clearly determine what it is that you are claiming.

Like a jigsaw puzzle:  As a useful analogy, consider each patent claim to be somewhat like a multidimensional jigsaw puzzle piece. Each claim should be written using words and clauses that, in addition to describing your invention, “bend in” to avoid prior art, and “bend out” when there is no prior art.

From the patent examiner’s standpoint, he or she is looking at your claims in the context of the other prior art (the other pieces). The examiner is determining if each of your particular claim “pieces” is fitting nicely into the holes between prior art, or if they are hitting the other prior art “pieces”.  If there is overlap, the examiner will, at a minimum, want you to make your claims “bend in more” to avoid that prior art.  Part of the process of writing patent applications is to try to anticipate where this might happen and to write the patent in a way that gives you more options to “bend in” and “bend out” during the patent examination process.

There is one big difference between jigsaw puzzles and patent claims, however.  In jigsaw puzzles, although the different pieces can’t overlap, the gap between the different pieces can be made very small.  Think of this gap as the area where, given that one piece is “bending in“, it is “obvious” that the other piece must “bend out“.

Unlike jigsaw puzzles, examiners often require that this “gap” be big enough so that the shape of your jigsaw puzzle piece (claim) is not immediately obvious in view of the shape of the neighboring pieces.  In fact, a big part of the patent examination process is negotiating the extent of this gap, and how best to amend the claims accordingly.

Continuation applications

Don’t like having your own inventions used against you?  Before your patent issues, consider filing a continuation application.

Continuation applications
Continuation applications

Just got your US patent application allowed?  Congratulations!  Now before it issues (usually about 2-4 months after you pay the issue fee), you need to decide if you ever will want to file any improvements or variations of that invention in the future.

If you do have some improvements or variations in mind, now is the time to start working on filing a “continuation-in-part” (or CIP).  In a CIP, you are basically telling the USPTO that you have added some new concepts to your original patent application.  This is OK – worst case the examiner may determine that the new concepts have a later filing date, but in any event, the examiner won’t hold your original patent application against you.

In contrast to a CIP, patent continuation applications are essentially a repeat of the original application. Any differences to the claims had better be fully disclosed in the original application.

Why file a continuation?  One common reason is that you think that you may be able to get stronger claims the second time around, perhaps by making the claims shorter and hence stronger.  Or perhaps there was something in the original application that you forgot to put into your original claims. Both types of claim changes are fine so long as you can show that the newer claims were fully disclosed in the original application.

A second common reason is a nagging fear that although you might not have thought of any improvements or variations yet, you can’t rule out the possibility that you might do so in the near future.  Here, if you don’t file a continuation, after your patent issues, your own patent will be used against your later patent applications as if someone else had invented it.

However if you do file a continuation, it essentially keeps your original patent “alive” a while longer (usually at least another year or so).  Then, if you do come up with an improvement, you can then file a CIP to your continuation application.  When you use this strategy, the USPTO will allow you to claim your later improvement without using your original application against you.

Foreign patent traps

It’s a trap!

Outside of the US, foreign patent offices will often use your own prior patent filings against you.  Avoid this trap by planning carefully.

Both US and foreign patent laws are based on various legal fictions.  One legal fiction is that an invention is instantly created in a fully formed state.  Another legal fiction is that even if a particular improvement to the invention was not actually obvious to the real inventor, still an examiner or judge may reject this improvement as being obvious to an imaginary “person of ordinary skill in the art”.  Patent law just doesn’t cope with hindsight well.

In practice, we all know that real inventions often come into life slowly, usually after much trial and error.  Complex inventions may take years to fully develop. The inventor is thus faced with a dilemma – file fast so as to be the first person to file, or keep working on the invention, file a better patent application, but possibly lose to someone who filed sooner?

US patent laws recognize this problem, and allow an inventor file as many patent applications as needed, even over a period of years, and gradually accumulate a “stack” of patent applications.  This stack of patent applications captures both the time of earliest invention, as well as a later time-optimized form of the invention. Intuitively this system seems fair.  Wouldn’t it be unfair to use an inventor’s own earlier work against the inventor?

Doesn’t this basic rule of fairness apply everywhere?  Unfortunately it does not.  The harsh reality is that outside of the US, other countries typically use an inventor’s own earlier patent applications against them.

This assumption of basic fairness often traps inventors and startups.  Here the only way to avoid the trap is to recognize that this problem exists, and take steps to mitigate problems.

As a good rule of thumb for international patents, assume that there is at most a 12 month window after a first (US) patent application has been filed in which to make further improvements. Plan accordingly. If you have thought up improvements to your invention, it is far better to submit these improvements as an updated PCT patent application before the 12 month anniversary of the first patent application.

After 12 months, you can’t claim the priority date of your first US filing. Someone else can jump ahead of you and claim credit.  Even worse, 18 months after filing (when usually your first US patent application will be published) your first US patent application can then be used against your later filed improvement.

It is very irritating to have an international examiner claim that your improved invention is obvious against your own earlier filed application.  Even more irritating when you know that in reality the improvement was totally not obvious.  Perhaps the improvement may have taken you a year or more of hard work!  Too bad — to the foreign examiner, your improvement is obvious.

The lesson here is: if you have made improvements, file them as an updated international patent within 12 months of the filing date of your first invention (or in an emergency, at least before your first patent application is published — usually 18 months after first filing).

Why patent searches and prior art searches are a good idea

Thinking like a detective

Prior art searches: Before investing a lot of time, effort, and money in trying to patent a potential new invention, it is always good to spend at least a few hours doing patent searches to see if there is any prior art (earlier patent or non-patent publications) that might cause problems. As a rule of thumb, if you haven’t found any prior art that concerns you at least a bit, then you probably haven’t looked enough yet!

Why do this? Because eventually, skeptical USPTO examiners will be going through your patent application, looking for ways to reject on the basis that the application is either not novel or obvious in view of prior art.

Patent examination is an adversarial process. Patent examiners have, in effect, quotas which require them to initially reject most patent applications. It is a bit of a game, like tennis, where the examiner initially rejects by citing some combination of prior art.  The examiner then hits the ball back onto the applicant’s side of the court. The examiner is expecting the applicant to hit the ball back onto the examiner’s side of the court by submitting convincing arguments pointing out where the examiner was wrong. If the applicant can convincingly argue that the examiner is wrong, usually (often after a few additional volleys), the examiner allows the patent, and the applicant wins. But if the applicant cannot argue back convincingly, it is like dropping the ball or hitting the ball back out of bounds. The applicant loses, and that patent application is going nowhere.

The patent examiner typically starts by doing computer searches for prior art using search terms that the examiner thinks will work best. This computer search will come up with unexpected citations, which the examiner may in turn combine in unexpected ways to try to show that the invention is “obvious”. Because of the quota to initially reject almost everything, often these initial rejections are unreasonable. Unreasonable rejections are “good news” in disguise, because the applicant can then rebut these by reasonable arguments. It is the reasonable rejections that are the real “bad news”, because these are harder to argue against. So before putting a lot of time and money into an invention, it is a good idea to do at least some initial checking to see what the examiner (or for that matter, a competitor) might try to use against you later. This is the idea behind a “feasibility study” type prior art search.

Sometimes, particularly when the inventor or inventors are experts, the inventors themselves may decide that they are sufficiently familiar with their field so that the search-time expense/benefit ratio is low, and no additional prior art searches are worthwhile. Here, since the USPTO will do an independent search anyway, the only obligation that the inventors have is to inform USPTO of the most important prior art that they are aware of.

Other times, particularly when the inventor or inventors are working in an area that is new to them, prior art searches have a better search-time expense/benefit ratio. Here many good sources are available over the Internet, including Google, Google patents, Google Scholar, the USPTO patent database, the WIPO patent database, and the like.

Some common mistakes that inventors make is to underestimate the amount of prior art that a patent examiner can use against their invention. Although pretty much everyone understands the problem of prior patent applications by others, this is only part of the prior art problem.

For example, for the US, anything published more than a year ago can be used against your invention, including your own publications. This includes that “cool” YouTube video, that “cool” social media posting, or that research paper/thesis that you may have published last year. Foreign patent offices are even worse in this regard. Patent examiners know that often the inventor’s own worst enemy is the inventor’s own earlier publications. As a result, patent examiners often specifically search for the inventor’s own publications and internet postings to use against them.

Another problem that inventors sometimes have is that they are a bit too emotionally attached to their cool new idea.  This problem can result in sub-optimal prior art searches. The inventor may, perhaps subconsciously, avoid search strategies that may kill that shiny new idea.

Here, there are several advantages to having a patent attorney do a quick feasibility prior art search for you. One is that the patent attorney does prior art searches all the time. Another is that the patent attorney, being both less emotionally invested in the idea, and being expert in finding prior art, may have an easier time thinking of thorough search strategies. The third is that often doing the search helps the patent attorney understand variants of your idea better, which can translate into a better patent application.

For example, if something highly relevant comes up (and often something does come up), then the new idea can be better evaluated in the context of this new-found prior art. The scope of the initial idea may be altered or expanded, and a better patent application can result. Worst case, if it becomes clear that the idea has been done before, then time and money can be saved. Alternative ideas can be explored instead.

In conclusion, “feasibility study” type prior art searches are a good a way to get at least a rough estimate of the legal feasibility of a new idea. Although the prior art search may uncover what looks at a first glance to be a tough obstacle, often this initial obstacle may encourage further thinking and improvements to the initial idea, resulting in a better patent down the road.

Note that in addition to “feasibility study” type prior art searches, there are other types of patent searches called “freedom to operate” searches or opinions as well. These represent a different and more extensive type of search, and this is a different topic.

Provisional patent applications: thoughts and suggestions

Provisional patent applications are a bit like duct tape — useful, but temporary.

Provisional patent applications: US patent law allows inventors (applicants) to file informally written disclosures with the US patent office.  These informal disclosures, called “provisional patent applications” (often abbreviated as “provisional patents”, “provisional applications”, or even just “provisional”), represent an excellent opportunity to quickly and inexpensively start the process of obtaining a patent.

Provisional patents are not usually examined. Instead they are merely stored in the USPTO databases for a year.  They are then discarded, unless within that year, the inventor then files a regular utility patent application that references that provisional application.  If this is done, the USPTO keeps the provisional stored forever.

Provisional patents are often useful because later, during examination of the subsequent regular utility patent, the inventor can reference the provisional patent to overcome examiner rejections (e.g. overcome other patent’s priority dates, supply additional detail, and so on).

Regular patents have detailed requirements with respect to format, figures, and claims, and tend to be expensive to file.  By contrast provisional patents have almost no format requirements, and they are inexpensive to file.  Almost anything that can be put onto paper (e.g. a PDF format) can be filed as a provisional application.  As a result, provisional patent applications can be as simple as a single page photograph of a napkin sketch, or as complex a fully developed 100+ page formal patent application.  The USPTO will cheerfully accept either one of these.

The lack of format requirements can be very helpful.  Many a patent application has been saved by the fact that the inventor had earlier filed something, such as a research paper or user manual, essentially as-is, as a provisional.  Although such items would never be accepted as a regular utility patent application, informal provisional patent submissions can be a quick way to put important information on the record.

This is the good news.  The bad news is that many a patent application has been lost because the inventor first filed an inadequate provisional application, and then operated under a false sense of confidence that he or she was protected by that inadequate provisional application.

The dangers of an inadequate provisional application are both delayed and subtle.  At first everything is fine.  Then, typically about 1-3 years after the inadequate provisional has been filed, trouble can start.

For example, suppose that the USPTO examiner rejects on the basis that someone else has filed another non-provisional (regular utility) patent ahead of the applicant’s regular utility patent.  Under today’s rules, almost the only way to establish that the applicant invented first is to cite the earlier filed provisional patent, and state precisely which parts of the provisional application prove that the inventor was first.

If the examiner reviews the provisional and agrees, then the provisional has been successful and the inventor will hopefully go on to successfully get the patent.  But if the examiner reviews the provisional and says, “I don’t see the invention here”, then the provisional has likely failed, and the inventor may never be able to prove that he or she invented first.

Three different provisional strategies:

Personally, I think that it is useful to think about three different categories of provisional patents.  These categories are: 1) quickly file your existing write ups; 2) file a rough draft of a regular utility patent; and 3) file a complete utility patent, but do so as a provisional patent rather than as a regular utility patent.

Category 1:  quickly file your existing write ups.  These can be existing papers, PowerPoint presentations, handouts, whatever.  The argument in favor of this approach is that this is the quickest way of getting something on the official patent record.  This may also be a quick way of filing a lot of supplemental information.  Worst case, an improperly thought out provisional can later be abandoned.  My personal views are that this approach is better than nothing, but it is not without pitfalls.

Category 2:  file a rough draft of a regular utility patent.  Many provisional applications are filed by inventors and small companies operating on a limited budget.  Here the goal is to try to quickly file something that is relatively decent, but also try to save money while a new idea is being evaluated.  Here, as a compromise between cost and quality, one way to go is to produce a rough draft of a utility patent, following the standard utility patent format, which provides some important structure.  This approach tries to capture a good chunk of the value of a full patent, while keeping costs at about 50% of a standard patent, by focusing time on a few key draft claims, informal but adequate figures, and at least the most important technical aspects of the disclosure.

Category 3:  file a complete utility patent, but as a provisional application.  In this third type of situation, funding may not be an issue, but the inventor thinks there is a possibility that they will make additional improvements to the invention over the next year.  Here a complete and detailed utility patent can be written, but is instead filed as a provisional patent rather than a regular utility patent.  This provisional application can then be “aged” for up to a year.  If there are no changes, the original provisional can then simply be refiled as a full utility patent.  Otherwise the changes can be dialed in, and an updated version filed as the full utility patent.  An additional advantage of this Category 3 approach is that it can effectively increase the lifetime of the final patent by up to a year.

A few other nuances – if you are interested in foreign patent filings, realize that the 12 month foreign filing deadline starts ticking from the time you file your provisional application.  Thus the 12 month provisional expiration deadline, and the US and foreign patent filing deadlines, all fall on the same day.

If it’s so obvious, why didn’t anyone think of it sooner?

Shoot the moon
Shoot the moon?

35 USC 103 “obviousness” rejections: The recent Federal Circuit case of Leo Pharmaceutical Products, Ltd. v. Rea, 2013 WL 4054937 suggests that the Federal Circuit may be starting to develop a new set of criteria and arguments that can help protect against hindsight bias in obviousness rejections.  In Leo, the Federal Circuit held that “to avoid the trap of hindsight”, probative evidence of nonobviousness should also be considered.  What was new was that the Leo court held that this can include both evidence of long felt but unsolved needs, and the length of time between the publication dates of the prior art (used in the obviousness rejection) and the claimed invention.  Specifically Leo court held that the existence of a large time gap between the prior art publications, and the invention, can also be used as indicia of non-obviousness.

How long must this time gap be?  The Leo court held that given a longstanding need, if the prior art citations used in the obviousness rejection are on the order of about 14-22 years old, then this is too long.  That is, such an extensive time delay is probative for non-obviousness because if the combination of such long known citations was actually obvious, then the combination would have been disclosed sooner.

An interesting consequence of this ruling is a novel (but risky) “shoot the moon” type of patent prosecution strategy for obviousness rejections.  That is, Leo can be interpreted as a Federal Court suggestion to find out how far back in time the relevant citations actually extend.  For example, if the prior art is actually 30 years old, but the citations used to demonstrate the prior art were only 5 years old, the following could be done:

  • Explore the roots of the 5 year old prior art citation
  • Trace back to the original 30 year old prior art
  • Disclose the 30 year old prior art citations
  • Make a Leo type argument

The logic seems sound – something known 30 years ago was also known 5 years ago.  The fact that the citations were not combined until the invention, despite a long-felt need, is probative that that the combination was not obvious.

This is arguably a “shoot the moon” legal strategy (i.e. a long shot).  So remember that as always, this is not legal advice, and Kids, don’t try this at home!