Describing Features of the Invention Both Broadly and in Detail

Drafting a patent application often involves  describing the invention both broadly and in detail. But how can something be described both broadly and specifically?A decision in a case between Sprint and Time Warner Cable illustrates one way.

In that case, Time Warner argued that the patents asserted by Sprint did not comply with the written description requirement. It argued that the claims were broader than what was described in the patent description. Time Warner argued that the patent description was limited to ATM networks. The appeals court disagreed.

The patent description at issue in the case included reference to “[b]roadband systems, such as Asynchronous Transfer Mode (ATM).” The court said that this wording “strongly suggests that the patents are not limited to ATM technology.”

In the Sprint case, Time Warner accused technology did not use ATM technology but instead used IP technology. If the patents did not describe broadly “broadband systems” it is less likely that the claims would have been useful to cover Time Warner’s IP-based system.

The form of the phrasing is “[broad or general descriptor], such as [detailed or specific descriptors].” This form can allow claims to the broad element while also specifying specific details in the patent application. Multiple detailed elements can be listed. For example, “a wireless protocol, such as WiFi, CDMA, 3G, 4G, LTE…” or another example, “a fastener, such as a screw, bolt, nail, rivet, hook and loop fastener….”

By describing an invention feature broadly first and then providing detailed examples of the broad element in an exemplary way, the invention feature is described both broadly and in detail. Describing the invention feature broadly provides the opportunity for broad patent coverage. Providing detailed examples supports the broad description and provides a fall-back position if some portion of the broad subject matter is already in the prior art.

Case Citation: Sprint Communications Company LP v. Time Warner Cable, Inc., No. 2017-2247 (Fed. Cir. Nov. 30, 2018).

Patent Drafting: Enabling Skilled Person to Make and Use the Invention

USPatent5231253_Fig3Automotive Technologies International (ATI) sued numerous vehicle and parts manufacturers including BMW and Delphi Automotive Systems for infringing US patent 5,231,253 on side impact crash sensors for deploying an air bag. The court of appeals determined that the patent was invalid for failing to enable the claimed invention in Auto. Techs. Int’l, Inc. v. BMW of N. Am., Inc., 501 F.3d 1274 (Fed. Cir. 2007).

The law requires that your patent application describe your invention to such a level of detail so as to enable one who’s skilled in the art to  make and use the invention, without undue experimentation. This is known as the enablement requirement. The relevant statute states that every patent must describe “the manner and process of making and using [the invention], in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the [invention].” 35 USC 112.

This is part of the patent bargain. You tell the world how to make and use the invention and the government grants you a limited monopoly.

It is not uncommon for an inventor to leave out details of the invention that he/she thinks are well known in the art. But you want to draft a application that is well within the knowledge of one skilled in the art area and no where near the boundary of what one skilled in the art knows. Therefore, you often want to explain concepts and details that one skilled in the art already knows. When in doubt, provide more detail.

This is true because when an inventor chooses to rely upon general knowledge in the art to render his/her disclosure enabling, the inventor bears the risk on this issue of whether those of ordinary skill in that can be expected to possess or know where to obtain this knowledge. In re Howarth, 654 F.2d 103 (CCAP 1981).  “To avoid the risk, [he/she] need only set forth the information in his specification…” And you should want to avoid this risk, as the ATI case demonstrates.

In the ATI case, the patent disclosed two impact crash sensors, one was a mechanical sensor and the other was an electronic sensor. The patent described the mechanical sensor at length (figure 1). But it only provided one short paragraph and one “conceptual” drawing (figure 11) about the electronic sensor. The court found the thin disclosure of an electronic sensor was not sufficient to inform one skilled in the art how to make the invention with the electronic sensor. Since the claims were broad enough to cover both mechanical and the non-enabled electronic sensors, all of the patent claims were found invalid.



The description of the electronic sensor in the patent failed to disclose a structure or circuitry  for the sensor. The court found that ATI could not rely on prior art knowledge of front electronic impact sensors because ATI stated that the novel aspect of the invention was the side impact sensor. The court said, “given that the novel aspect of the invention is a side impact sensor[], it is insufficient to merely state that known technologies case be used to create an electronic sensor. Moreover, there were no electronic sensors in existence to detect side impact crashes at the time the application was filed.

Also, the court stated electronic sensors are of the same class of technology as mechanical ones: “Electronic side impact sensors are not just another known species of genus consisting of sensors, but are a distinctly different sensor compared with the well-enabled mechanical side impact sensor [described]…”

As the ATI case demonstrates, it is best not to get close to the line between what is and is not enough detail to enable a person skilled in the art to make and use your invention. Instead you should spend the time to provide the level of detail, with respect to each variation of the invention, so there can be no question. And that often involves describing details known to one skilled in the art.

LEGO Patent Demonstrates Why Your Patent Application Should Describe Alternative Versions of the Invention


To protect an invention broadly, a patent application should describe alternative versions of the invention. When developing an invention it may be that several variations of the invention or a component of the invention are considered before a final version is settled on for production.

You often have a better chance of obtaining broad patent protection if those unused variations of the invention are included in the application along with the final version.

The LEGO Patent and Alternatives

The patent on the LEGO building block toy (U.S. Patent No. 3,005,282) provides a good example. The patent includes not only the iconic block that many recognize, shown at the top of this post. But it also includes six other versions that I have not seen on the market and may not ever have been on the market. Figure 1 shows a version that only has a top plate 10 and no sidewalls 12.



Figure 8 shows an alternative block having two internal projections 22 rather than three shown in figure 4.


Figure 9 shows an alternative block having X-shapped projections 23 rather than circle shaped projections 22 shown in figure 4.

LEGO_Fig9 Figure 10 shows an alternative block having somewhat star-snapped projections 24.


Figure 11 shows an alternative block having multi-component projections 25 that appear similar to the projections 24 of figure 10 but with the corner curved portions removed.


Figure 12 is an alternative block comprising a square shape rather than a rectangle shape and having one projection 22.


How Disclosure Impacts Patent Scope

Claim 4 of the LEGO patent is directed to a toy building block having “…at least one secondary protuberance extending from said inner face of said bottom wall…” The secondary protuberance is a general reference to the projections that extends below the plate 12, such as projections 22.

However because the patent described many alternative styles of such projections 22, 23, 24, 25, the “secondary protuberance” in the claim would not be limited to cylindrical or circular projections 22 shown in figure 4. Instead, the term “secondary protuberance” should be given a broader meaning to cover different shapes and types of protuberances.

However, it is possible that if the LEGO patent only included cylindrical projections that the claims might be limited to projections of that shape. See my discussion of Tronzo v. Biomet, Inc., 156 F.3d 1154 (Fed. Cir. 1998) for more on this point.

Further, as the patent discloses versions of the block with different numbers of projections, e.g 1, 2, and 3 projections, the patent was able to claim the broader “at least one secondary projection” rather than being limited to “three secondary projections” that are shown in the well known version of the block. In that way, a competitor cannot get around the patent by using 2 or 4 projections to avoid a “three secondary projections” limitation. Instead the use of 2 or 4 projections would be covered by the “at least one secondary projection” limitation of the claim.

Your patent application should probably follow the lead of the LEGO patent in providing alternative versions of your invention. This gives you a better opportunity to get broader protection on your invention and it blocks your competitors from patenting the alternative versions of your invention.

Burnt Dough and the Difficulties in Patent Drafting

“[E]ven if, as plaintiff argues, construing the patent to require the dough be heated to 400 degrees to 850 degrees Farenheit [sic] produces a nonsensical result, the court cannot rewrite the claims. Plaintiff’s patent could have easily been written to reflect the construction plaintiff attempts to give it today. It is the job of the patentee, and not the court, to write patents carefully and consistently.” – Colorado United States District Court

Patent claim drafting requires careful attention. The difference between the use of “to” and “at” in a claim directed to a method of producing dough, resulted in the difference between a worthless patent claim and a patent claim that might have had value. This is why going the DIY route with a non provisional utility patent application is very difficult.

Chef America Inc owned US Patent 4,761,290 directed to a process of producing a dough product with certain desirable attributes. Chef lost when it sued  Lamb-Weston for infringement because the patent claim literally required the dough “to be heated to a temperature in the range of about 400° F to 850° F” in Chef America v. Lam-Weston, Inc., 358 F.3d 1371 (Fed. Cir. 2004).  Heating the dough to that temperature would result in dough that was burned to a crisp, resembling a charcoal briquet. Instead, that patent owner really meant that the dough had to be heated at that temperature. In other words, the oven needed to be set at that temperature. But the internal temperature of the dough did not need to reach that temperature.

Chef American argued that one skilled in the art would recognize the claim meant “at” rather than “to” given the nonsensical result that the dough would be completely burnt if the dough was heated to about 400° F to 850° F. But the court refused to change the claim to avoid the burnt dough result. The district court said:

[E]ven if, as plaintiff argues, construing the patent to require the dough be heated to 400 degrees to 850 degrees Farenheit [sic] produces a nonsensical result, the court cannot rewrite the claims. Plaintiff’s patent could have easily been written to reflect the construction plaintiff attempts to give it today. It is the job of the patentee, and not the court, to write patents carefully and consistently

The Appellate court agreed saying that “courts may not redraft claims, whether to make them operable or to sustain their validity.” The court further stated “Even a nonsensical result does not require the court to redraft the claims of a patent.”

The court noted that references to temperatures in the description of the patent used “at” and “to”  in different places. Therefore when the patent owner choose “to” for use in the claims, the court was constrained from finding it meant “at.”

The court concluded that the claim unambiguously requires that the dough be heated to a temperature in range of 400° F. to 850° F–in other words to be completely burnt to a crisp. As a result, Lamb-Weston did not infringe and Chef America’s patent claims at issue were essentially worthless.

Sometimes errors in a patent can be fixed. In this case the patent owner did not request an amendment to the claims. Rather the patent owner wanted the court to read the claim the way most people would have understood it. But the court would not do that. Patent drafting is not easy. And careful attention is required when drafting patent applications.

Don’t Admit That: Problems in DIY Patent Application Drafting

“Mr. Morsa … admitted in the specification that the system as described in the patent ‘can be implemented by any programmer of ordinary skill . . . ‘ . . . Therefore, by using Mr. Morsa’s admissions, the Board simply held him to the statements he made in attempting to procure the patent.” – Federal Circuit Court of Appeals.

US20030093283A1_Fig3Properly drafting your own patent application can be difficult. Client-drafted DIY patent applications sometimes say too much, don’t say enough, or both. A client drafted patent application can say too little by failing to describe the invention with sufficient detail. And a client drafted patent application could say too much by making unnecessary admissions that can negatively impact the application.

In the case of In Re Morsa, No. 2015-1107 (Fed. Cir. 2015), the applicant wrote his own patent application and in doing so made admissions that contributed to the final refusal of his patent application. This case demonstrates how admissions in the patent application can negatively impact the prospect obtaining a patent.

Morsa’s Application

Morsa filed his patent application directed to a method and apparatus for furnishing benefits information. Claim 271 of his application provided:

A benefit information match mechanism comprising:

[1] storing a plurality of benefit registrations on at least one physical memory device;

[2] receiving via at least one data transmission device a benefit request from a benefit desiring seeker;

[3] resolving said benefit request against said benefit registrations to determine one or more matching said benefit registrations;

[4] automatically providing to at least one data receiving device benefit results for said benefit requesting seeker; wherein said match mechanism is operated at least in part via a computer compatible network.

The patent office cited a publication entitled Peter Martian Associates Press Release, dated September 27, 1999 (“PMA”) to show claim 271 was not new. Morsa argued that PMA did not provide enough detail to enable one skilled in this art to create Morsa’s claimed invention from the PMA without undue experimentation.

Prior Art

The Court maps disclosures from PMA to each of the elements of Morsa’s claim. The Court said with respect to each of the elements:

[1] [Regarding the first element] …the PMA reference describes the storage of “benefits and services that consumers receive from public and private agencies” along with the storage of “benefits services, health risks, or anything else an agency wishes to implement via its eligibility library.

[2] [The second element] correlates with the PMA’s statement that “consumers use the web to screen themselves for benefits, services, health risks, or anything else an agency wishes to implement via its eligibility library.”

[3] [The third element] maps onto the PMA’s use of the internet.

[4] [Regarding the fourth element] the PMA reference allows “consumers [to] use the Web to screen themselves for benefits, services, health risks, or anything else an agency wishes to  implement via its eligibility library.”

Morsa’s Admissions in his Patent Application

Morsa argued that these high level statements in PMA did not provide enough detail to enable one create Morsa’s claimed invention. The Patent Office solved this problem be pointing to admissions in Morsa’s application (“the specification”) as to what one skilled in the art would have known at the time of the invention.

The court noted that Morsa’s specification admitted that:

  1. central processing units and memories were “well known to those skilled in the art,”
  2. central processing units and memories were “used in conventional ways to process requests for benefit information in accordance with stored instructions,”
  3. the system as described in the patent application “can be implemented by any programmer of ordinary skill in the art using commercially available development tools . . . ,” and
  4. “search routines for accomplishing this purpose are well within the knowledge of those of ordinary skill in the art.”

Therefore, based on those admissions, the Court concluded that one of ordinary skill in the art was capable of programming the invention based on the disclosure in the PMA reference.

In other words, the Court used Morsa’s admissions in the application to “fill in the gaps” in PMA as to what one skilled in the art would have know how to do related to Morsa’s invention.

Avoid Admissions in Application

If Morsa had not made such admissions, the Patent Office would have need to work harder to find reference that described the what one skilled in the art would have known at the time.

It probably would not have been too hard for the Patent Office to find a reference that described the use of databases and searching routines for use in an obviousness rejection. And, it possible that even if Morsa had not made the admissions in his application that his application still would have been refused.

Nonetheless, you do not what to make it easy for the patent office to refuse your patent application. Admitting that portions of an invention are “within the knowledge of those of ordinary skill in the art” or “well known to those skilled in the art” can be a problem, as shown in the Morsa case.

The reason Morsa made those admissions was so that he did not have to describe details of the items referenced as known, e.g. CPUs, search routines, etc. It’s a short cut.

But, it is better to describe the details of missing item or process or otherwise formulate statements without admitting components of the invention or the processes of making those components are “known by one skilled in the art.”

There maybe some instances where it would be acceptable to admit that a common component of the invention could be made by methods known by one skilled in the art. However, doing so is a double edge sword that can hurt you if not done properly. Given the potential downsides it is safer generally to avoid making such admissions.

How to Obtain Broad Patent Protection: Describe Alternate Versions of the Invention

US4743262_WrittenDescriptionClients often wonder why a patent application on a relatively simple invention is relatively long. The answer is that even the most simple inventions are not simple to describe properly in a patent application.

To write a strong patent application, the invention needs to be described to a level of detail that many clients would not have thought necessary.

Its not unusual that a client brings a 3 to 5 page provisional patent application that the client wrote themselves, and the non-provisional application I write is at least three to four times as long, or 15 to 20 pages or more.

This is why DIY patent applications are difficult to write well (but there are options and trade-offs when money is tight).

The details and length are necessary because that content lays a foundation for a potentially broad patent. That detail in the patent application should include, were possible, a description of alternative ways of making and/or using your invention.

Patent attorneys call these alternative ways of making and/or using your invention, different or alternate embodiments of the invention.

To illustrate why it is important to describe alternative ways of making and/or using your invention, we can look at the case of Tronzo v. Biomet, Inc., 156 F.3d 1154 (Fed. Cir. 1998).

Describing Only One Way of Making/Using Your Invention is Limiting

In the Trozno case, the patent owner obtained Patent 4,743,262 (the ‘262 patent) on a cup for a hip replacement device. The parent patent application of the resulting the ‘262 patent only described the cup as a “conical cup.” The patent claim did not include the conical limitation for the cup. So the patent claim was to a generic cup, without limitation to the shape of the cup.

The defendant’s device used a hemispherical cup.

So the question was whether the description of “conical cup” adequately supported the claim to a generic cup.  If so, the claim would cover more than just conical cups but would cover cups of other shapes, such as the defendant’s hemispherical shaped cup. If not, the claim was not entitled to the filing date of the parent application for failing to comply with the written description requirement.

The written description requirement in patent law provides that the patent application must “contain a written description of the invention, and of the manner and process of making and using it.” Courts have said to meet the written description requirement that application must reasonably convey to one of skill in the art that the inventor possessed the claimed subject matter at the time the application was filed.

In the Trozno case, the court found that the parent application only described one shape of cup, the conical shaped cup. The patent owner’s attempt to claim the broader generic cup was overreaching beyond was described in the application. The end result was that the claims were invalid and did not cover the hemispherical cup in the product provided by the defendant.

Describe Multiple Variations of Your Invention and Its Components

How could this have been avoided?  In reasoning that the ‘262 patent only covered conically shaped cups, the lower court noted that the patent application did “not attempt to identify other, equally functional shapes or talk in terms of a range of shapes.”

There you have it. The court tells you how to get broader coverage. You get broader coverage by  providing a description of a number of different shaped cups in the application.

The application might have used language such as, “a cup is provided, the cup may comprise a rounded shape, a hemispherical shape, conical shape, a cylinder shape, an elliptical shape” etc. Of course, it is important to list shapes or variations that would actually work in the invention. But the point is that you want to list alternate variations of the components and aspects of the invention.

When listing the generic component “cup” along with various options for the shape of the cup, this enables you to write boarder claims. Boarder claims provide you with a stronger patent because you may be able to use broad language in your patent claims, e.g. the broad generic “cup” vs. the limited “conical cup.”