Monday, November 15, 2010

Federal circuit holds structural limitation in method step is limiting despite "comprised" in preamble

Takeaway: In a 1986 claim construction decision, the Federal Circuit held that a method claim which referred to "engaging eight cube pieces" was limited to a 2x2x2 cube despite the use of "which comprised" in the method preamble. Furthermore, the cube size was not expanded by the use of "comprising" in one of the steps: "rotating a first set of cube pieces comprising four cubes about a first axis." The court found that "comprising" was not used as a transitional phrase when describing the first set. Moleculon Research Corp. v. CBS, Inc. (Moleculon II), 793 F.2d 1261 (Fed.Cir. 1986). An old case, but an important one.

Details:
Moleculon Research Corp. v. CBS, Inc. (Moleculon II),
793 F.2d 1261 (Fed.Cir.1986)

This is a claim construction and literal infringement case. The method claim at issue involves a solution for what you may recognize as a mini Rubiks' cube.

3. A method for restoring a preselected pattern from sets of pieces... which comprises:
a. engaging eight cube pieces as a composite cube;
b. rotating a first set of cube pieces comprising four cubes about a first axis;

The accused products included the classic Rubik's cube and the super Rubik's cube. The classic cube included 27 pieces (3 x 3 x 3), where you rotate 9 at a time. The super cube included 64 pieces (4 x 4 x 4), where you rotate 16 at a time.

The district court found that even though the larger cubes were not 2 x 2x 2, infringement was nonetheless present because claim used the magic word "which comprises" in the preamble:
Claim 3, and its dependent claims, 4 and 5, read on the 2 × 2 × 2 form of the puzzle, as well as on such larger cubic embodiments as the 3 × 3 × 3 and the 4 × 4 × 4, because it employs the open transitional phrase "which comprises." The term "comprising" denotes a patent claim as being "open," meaning that the recitation of structure in the claim is open to additional structural elements not explicitly mentioned.
(Emphasis in original.)
On appeal to the Federal Circuit, the accused infringer (CBS) argued that "in solving the 3 × 3 × 3 Rubik's Cube or the 4 × 4 × 4 Rubik's Revenge there is no step of 'engaging eight cube pieces as a composite cube'." Infringement is avoided when a method claim's step is "missing" from the accused method. (Amstar Corp. v. Envirotech Corp. 730 F.2d 1476 (Fed.Cir.).)

The patentee (Moleculon) argued that "which comprises" in the preamble allowed for larger cubes:
Moleculon counters that using the transitional phrase "which comprises" not only opens the claim to additional steps, but also opens the claim and its individual method steps to additional structural elements.

The Federal Circuit held that the 3 x 3 x 3 cube did not infringe.

In considering the patentee's argument about the transition in the preamble, the court concluded that "the transitional phrase does not, in the present case, affect the scope of the particular structure recited within the method claim's step." The court didn't find the accused infringer's "missing step" argument persuasive either, noting that the step wasn't missing, merely different.

The court framed the issue as the effect of the structural limitation, within the step, on the cube size:
[Step a] ("engaging eight cube pieces as a composite cube") contains a structural recitation ("eight cube pieces"). The question before us is not whether, because of the transitional phrase "which comprises," the step reads on a step of an accused method which recites additional structure (hypothetically, "eight cube pieces and six metal plates"), but rather whether this step which recites engaging "eight cube pieces as a composite cube" reads on a step which engages more than eight cube pieces as in the 3 × 3 × 3 Rubik's Cube or the 4 × 4 × 4 Rubik's Revenge.

After referring briefly to district court decisions where structural recitations in a method claim step were construed as limitations, the court held that:
[C]laim 3 is limited, at least for purposes of literal infringement, to a method for restoring a 2 × 2 × 2 composite cube. That interpretation follows not only from the language of step (a), but also from the way the eight cube piece composite cube is manipulated in steps (b), (c), and (d). These steps are limited to manipulating sets of four cubes only.
With regard to step (b), the court noted the use of "comprising" in that step didn't help the patentee either because it wasn't used as a transitional phrase:
During oral arguments, Moleculon argued that the word "comprising" in step (b) ("rotating a first set of cube pieces comprising four cubes about a first axis") means that the step covers four cubes or more. "Comprising" is not used here as a transitional phrase and has no special legal effect as such. Hence, it should be interpreted according to the normal rules of claim interpretation. No analogous word precedes the structural recitation of the number of cube pieces in steps (a) and (c). "Comprising" in step (c) reasonably interpreted means "having" but not "having at least."
Having found that the district court's interpretation was erroneous, the court vacated the finding of infringement. However, the court then remanded because the district court didn't make any findings about how the doctrine of equivalents applied to the larger 3 × 3 ×3 cube.

Postscript: On remand, the district court found that the method claims were directly infringed, through the doctrine of equivalents, by users playing the 3x3x3 cube. Moleculon Research Corp. v. CBS, Inc., 666 F.Supp. 661 (D.Del.1987) (Moleculon III). However, the Federal Circuit reversed, finding that the district court's analysis "entirely reads the number of cubelets and their corresponding engagement/rotation out of every step of the claim."

My two cents: I agree with this analysis. I see it as a good case for accused infringers and a bad one for patentees. But the Federal Circuit hasn't always used Moleculon II in this way.

I think the Federal Circuit got Moleculon II right in Spectrum Intern., Inc. v. Sterilite Corp., 164 F. 3d (Fed. Cir. 1998). The court in Spectrum found that a claim did not include additional elements and cited Moleculon II for the proposition that " 'comprising' is not a weasel word with which to abrogate claim limitations."

Yet the Federal Circuit cited Moleculon II years later for the unremarkable proposition that "open language of claim 1 embraces technology that may add features to devices otherwise within the claim definition." Gillette Co. v. Energizer Holdings, Inc., 405 F.3d 1367 (Fed. Cir. 2005). Sure, this is a general statement of the law – that's why I said it was an unremarkable proposition – but it's not really what Moleculon II was about. The court in Gillette went on to find that "a group of first, second, and third blades" could include additional blades because the apparatus preamble used the transition "comprising." That's the opposite of Moleculon II, as pointed out by the dissent in Gillette.

There are differences in the three cases, of course, which can perhaps be used to reconcile them. Moleculon II didn't look to anything but the plain language of the claims to reach its result.  Spectrum reached the same result as Moleculon II after examining statements made during prosecution. Gillette reached the opposite result as Moleculon II after examining the specification, several other claims, and the prosecution history.


Waiting on In re Jung: is there a requirement for the Examiner to present a prima facie case?

Takeaway: Most of the BPAI decisions that are appealed to the Federal Circuit involve fairly routine reviews of prior art rejections. In re Jung is different: it's about the Examiner's requirement to make a prima facie case. As such, In re Jung has the potential to greatly impact patent prosecution. As elegantly put in Jung's brief, when the Examiner does put forth of a prima facie case, "applicants are sufficiently informed as to the full basis of the rejection ... and applicants can determine how to best proceed during initial prosecution." But if the BPAI doesn't provide an independent review of the prima facie case requirement, "applicants are all but required to prophylactically submit rebuttal evidence against uncertain and shifting grounds of rejection."

I've been following this case since the appeal was filed, and have read the briefs to the Federal Circuit (available from Westlaw or Lexis) as well as most of the file history (on PAIR: Appl. No. 10/770,072). Oral arguments took place a couple of weeks ago. Here are my thoughts on this interesting case.

Summary:
In Jung's brief, he asks the Federal Circuit to decide an issue of first impression: whether the BPAI properly ruled on the merits of an anticipation rejection instead of ruling on the appealed issue of whether the Examiner had made a prima facie case of anticipation. Jung's brief further defines the prima facie case of anticipation as having two requirements: (i) the Examiner must construe the claims under the broadest reasonable interpretation standard; and (ii) the Examiner must "adduce sufficient evidence to bridge any facially apparent 'teachings' of the applied reference."

The PTO doesn't see it this way. In the PTO's brief to the Federal Circuit, the Solicitor frames the issue as a routine review of a BPAI decision: "whether a reasonable claim construction and substantial evidence support the Board's conclusion that the prior art, Kolinksy, anticipates Jung's claim 1."

I don't know how much leeway the Federal Circuit has in choosing between issues. As a patent prosecutor, I hope the Federal Circuit does take up the issue of a prima facie requirement. But if the Federal Circuit wants to avoid the issue, I think it can do so on the grounds that Jung didn't properly raise the issue below. The PTO makes a convincing case that Jung did not challenge the prima facie case before the Examiner or before the BPAI, but instead substantively responded to the merits of the rejection. Thus, it seems to me that Jung may have waived his right to argue the prima facie requirement issue on appeal to the Federal Circuit.

Moreover, I think that Jung loses even if the Federal Circuit takes up the issue. That is, I think the Examiner did present a prima facie case. The claim term at issue was "well-charge-level controller." The Examiner explained that he gave each of the words their ordinary meaning, and explained how the reference taught a device that controlled the level of charge in a well.

That said, I am thrilled that Jung, even with these bad facts, took this issue up to the Federal Circuit. Because the PTO's idea of prima facie case – as expressed in the Solicitor's brief – is not enough. The way I read the brief, the PTO has taken the position that the Examiner produced a prima facie case of anticipation merely by: i) asserting that every claim limitation was disclosed by the reference; and ii) clearly designating what part of the reference was relied on. I dunno about you, but I need more than that to mount a good attack on a rejection. I want what Jung wants – explicit claim construction and an explanation of how the words used in my claim are met by the words used in the reference.

Wrap-up: I'll post again when the court releases its decision. The court may choose not to provide a full opinion. I'll be very disappointed if the opinion is nothing more than a bare Rule 36 affirmance. This case deserves at least a Rule 36 affirmance with a short explanation of the grounds of decision, since there is such a discrepancy between how the two parties framed the issues.

Thursday, November 11, 2010

BPAI reverses rejection of "configured to move" because Examiner's statement that reference "could move" was speculation

Takeaway: In Ex parte Tipley, the claims described physical parts "configured to" move in a specified manner. The Examiner acknowledged that the reference did not teach parts configured to move as claimed. The Examiner insisted that the reference nonetheless anticipated by treating "configured to" as "capable of" and further insisted that the parts in the reference could move as claimed. The Board treated this as an inherency argument. The Board then found that the Examiner's understanding that the parts could move was simply speculation. Since speculation is not enough to support inherency, the Board reversed the anticipation rejection.

Details:

Ex parte Tipley
Appeal 2009000300, Appl. No. 11/108,338, Tech. Center 2800
Decided September 18, 2009

The claims were directed to an arrangement of circuit boards in a computer. Two of the appealed claims are shown below, with the limitations at issue being highlighted:

5. A computer system comprising:
a first circuit board comprising a first connector;
a second circuit board ... having a second connector couplable to the first connector, wherein the second circuit board is configured to move in a first direction along the first circuit board to generally align the first and second connectors;

18. A computer system comprising:
a first circuit board comprising a first connector;
...a second circuit board coupled to the housing, wherein the second circuit board comprises a second connector; and
a biasing mechanism coupled to the housing, wherein the biasing mechanism is configured to bias the second circuit board along a curved path to connect the first and second connectors in the second position of the module.

The Examiner rejected all independent claims as being anticipated by the same reference.

With regard to the "configured to move in a first direction" limitation, the Applicant argued in the Appeal Brief that the limitation was not present in the reference because "housing end 70 blocks the daughter board 8 from moving along the mother board at one end, and surface 34 of housing end 72 blocks the daughter board from moving along the mother board 14 at the other end." [See Fig. 2 below.]


In the Answer, the Examiner further explained the rejection as follows:
[P]lease note that the recitation that an element is "configure to" perform a function is not a positive limitation but only requires the ability to so perform. In this case, Grabbe discloses that the second circuit board (8) can move in a first direction along the first circuit board (14), as shown in the following figure. (Emphasis added. See Fig. 1 below.)
 
The Board noted that the Examiner did not point to an express teaching of the limitation, and therefore analyzed under an inherency theory:
[W]e note that the Examiner’s finding, portrayed in the figure on page 8 of the Answer that allegedly shows the daughter board moving in a direction along the mother board via a directional line added by the Examiner, is based on the mere possibility of such movement and thus is speculative and insufficient to establish the inherency of such movement. The Examiner does not provide any reasoning to support such a determination.
The Board therefore reversed the rejection of the claim (claim 9).

With regard to the "configured to bias the second circuit board along a curved path" limitation, the Applicant argued in the Appeal Brief that the limitation was not present in the reference because:
the daughter board 8 is in contact with a ledge 68, it is impossible for the daughter board 8 to move along a curved path. See Grabbe Fig. 5. As such, the daughter board 8 moves laterally in a straight direction along the surface of the ledge 68 until the engaging surface 38 couples with the connector. [See Fig. 5 below.]

In the Answer, the Examiner further explained the rejection as follows:
[I]t is again noted that the recitation that an element is "configure to" perform a function is not a positive limitation but only requires the ability to so perform. In this case, the second connector (4) of  Grabbe can rotate around a pivot structure and along a curved path, as shown in the following figure. (Emphasis added. See Fig. 3 below.)
Once again, since an express teaching was missing, the Board analyzed under an inherency theory, and found the Examiner's rejection to be in error:
In this regard, we note that the Examiner’s finding portrayed in the figure on page 10 of the Answer that allegedly shows the daughter board 8 moving in a curved path via a curved line added by the Examiner is mere speculation. The Examiner does not provide any reasoning to support a finding that Grabbe’s circuit board inherently moves in a curved path. (Emphasis added.)

My two cents: I don't view this case as being about inherency, at least not in the classic sense. The Examiner's position seems to be that there is no difference between "capable of" and "configured to". The parts in the reference were not designed to move in the claimed manner – but could move a micrometer or two if enough force was applied.

I have two objections to the Examiner's argument. First, even if the claims used the phrase "capable of", this is a strained interpretation of that phrase "capable of". It's akin to saying that one piece glued to another is "capable of being released" simply because the pieces come apart with a pry bar. Second, the claims didn't even use "capable of", they used "configured to." The Examiner's interpretation of "configured to" is simply unreasonable in my opinion.

It's been a long time since I saw a "creative" rejection like this. I wish the Board had hit the Examiner's argument head on rather than shoehorning it into an inherency framework.

Monday, November 8, 2010

BPAI reverses obviousness when alleged benefit related to a different feature than claimed (Ex parte Keller)

Takeaway: The BPAI reversed an obviousness rejection because the benefit relied on by the Examiner as a motivation to combine (improved performance) was not related to the feature claimed, but was instead a benefit of another feature also taught by the reference. (Ex parte Keller.)

Details:
Ex parte Keller
Appeal 2009009225, Appl. No. 11/176,819, Tech. Center 2100
Decided June 15, 2010

The claims on appeal related to a memory controller in a computer. Dependent claim 5 was rejected as obvious, and the feature argued by the Applicant related to selective interleaving: "wherein said method further comprises selectively only interleaving storage of consecutive memory chunks across said multiple sets of said physical dynamic memory devices within said first portion of said memory array,"

The Examiner rejected the parent independent claim using a combination of two references, and added a third reference (Roy) to reject dependent claim 5. As a motivation to combine Roy's interleaving technique with the other two references, the Examiner offered:
Roy teaches performance improvement techniques such as interleaving can reduce the memory system bus cycle time by up to half that of any of the DRAMs individually.

The Board first found that the combination did not disclose selective interleaving as described in claim 5. Roy disclosed the existence of two types of computer systems: those that interleave memory and those don't interleave memory. However, the Board found that this did not amount to a teaching of a system that selectively interleaved some chunks of memory while not interleaving other chunks of memory.

The Board went further to reject the Examiner's motivation to combine, finding that the teaching used by the Examiner as a motivation to add Roy to the combination did not relate to the feature used in the combination – selective interleaving. The benefit of reduced cycle time related instead to a different feature – increasing width of the data bus.

The Board found the Examiner's motivation to combine deficient in yet another way: solving the problem noted in the reference simply didn't suggest the claimed feature of selective interleaving:
Even if this disclosure related to the interleaving memory technique, recognizing problems with interleaving memory would not have taught or suggested combining interleaving and non-interleaving using a single memory array.

My two cents: The rationale used by the Examiner for the combination – improved performance – is an example of what I call a "generic rationale". This decision shows one of two ways I know to fight a generic rationale: argue that the Examiner hasn't shown that the combination actually provides the benefit. The second is to argue that the alleged benefit isn't really beneficial at all or is outweighed by drawbacks.

What initially drew my attention to this decision was the Examiner's mistake in relying on an advantage that wasn't related to the claimed feature. However, the Board's initial finding that the combination did not teach all the elements contained a useful nugget also.

Specifically, a reference that discloses the presence of a particular feature in one embodiment along with the absence of the same feature in another embodiment does not teach selectively enabling the feature. I've seen this sort of rejection before, and I'm glad to to see the Board is persuaded by this reasoning.  

Related posts: Ex parte Khayrallah, which I discussed here, makes the point that disclosure of two options for building a system is not selective disablement of options during system operation. Ex parte Rykowski, which I discussed here, is another example of a successful attack on a generic rationale.




Sunday, November 7, 2010

Overview of 1.132 expert declarations

A few weeks ago the Reexamination Alert blog ran a story (here) about a Tivo patent which survived an ex parte reexamination. (Details in PAIR, Reexam Control No. 90/009329). Though a great many reexams go to appeal, that wasn't needed here because the Examiner was persuaded by expert declarations filed in response to the final Office Action. The Reexamation Alert put it like this:
TiVo’s present success is the result of an interview with Examiners followed by two very powerful declarations. TiVo was represented at the interview by counsel, but also by TiVo co-founder and ‘389 patent co-inventor Jim Barton, as well as UCLA Professor John Villasenor. Barton’s declaration, and presumably his presentation at the interview, established a critical nexus between the substantial commercial success enjoyed by TiVo’s digital video recorder and the “automatic flow control” required by claims 31 and 61. Dr. Villasenor’s declaration detailed the technical distinctions between the ‘389 claims and the prior art, which he asserted “simply reacts to the flow and does not control it.”  Villasenor also argued that one skilled in the art would have no reason to combine the references in the manner proposed in the final rejection.

The use of expert declaration evidence is patent prosecution is a topic of particular interest to me, so I reviewed some of the file history, and in particular the declarations and responses which relied on this evidence. I've reviewed many Board decisions dealing with expert declarations, and in doing so have learned about some of the common problem areas with declarations. From what I can see, the expert declarations in this Tivo reexam skillfully handled several areas which Applicants often have trouble with.


Here's a few of the things that Tivo got right in its use of expert declarations -- along with the case authority for why I say each is "right":
  1. Most importantly, Tivo used a declaration to explain technical facts, rather than simply putting this in a response as "mere attorney argument." In re Geisler, 116 F.3d 1465, 1470 (Fed. Cir. 1997)(attorney argument without factual evidence will not rebut prima facie obviousness).
  2. The declaration includes credentials and those credentials are relevant to the art. For a discussion of the relevant case law, see my post here.
  3. The declaration explains the relationship of the declarant to the assignee. Failure to do so can implicate inequitable conduct. An undisclosed business relationship between a patent applicant and a declarant is material if "(1) the declarant's views on the underlying issue are material and (2) the past relationship is a significant one." Ferring B.V. v. Barr Labs, Inc., 437 F.3d 1181, 1188 (Fed. Cir. 2006).
  4. The declaration itself gives facts and then draws technical conclusions, rather than conclusions unsupported by fact. The Board has broad discretion to accord little weight to declarations expressing an opinion as to fact when there is a lack of factual support for the opinions expressed. In re Am. Acad. of Sci. Tech. Ctr. , 367 F.3d 1359, 1368 (Fed. Cir. 2004).
  5. The declaration itself doesn't make legal conclusions. This is the proper role of attorney argument: to make a legal conclusion such as"not obvious." “An expert’s opinion on the ultimate legal conclusion is neither required nor indeed ‘evidence’ at all.” Mendenhall v. Cedarapids Inc. , 5 F.3d 1557, 1574 (Fed. Cir. 1993) (quoting Nutrition 21 v. United States, 930 F.2d 867, 871 n.2 (Fed. Cir. 1991))

In future posts I'll discuss some of these requirements in more detail. In the meantime, you can see a few posts which touch on expert declarations by selecting the label "1.132" in the list of Labels on the right-hand side of the blog.

Tuesday, November 2, 2010

BPAI finds swear-behind declaration insufficient for using different terminology than in the claims

Takeaway: In Ex parte Disney, the Board found that a swear-behind declaration did not show conception of a claimed spatial relationship because the claims used different terminology than the evidence. Specifically, the claims referred to the dimension as "vertical depth" and the inventor's notebook and invention disclosure form referred to the dimension as "long." Therefore, when differences in terminology exist between the evidence and the claims, you should also show that the terms are equivalent.

Details:
Ex parte Disney
Appeal 2008005465, Appl. No. 10/929,590, Tech. Center 3600
Decided: February 25, 2010

The technology in this application related to the structure of a transistor. The element at issue was:

first and second field plates disposed in the dielectric material of the first and second trenches, respectively, the first and second field plates having a first vertical depth ...
first and second gate members disposed in the dielectric material between the first and second sidewalls of the mesa, and the first and second field plates, respectively, the first and second gate members having a first vertical depth that is less than 20% of the first vertical depth.

Applicant submitted a declaration under § 1.131 to antedate the § 102 reference. The declaration attempted to establish conception before the effective filing date of the reference, coupled with diligence up to the time of filing of the application. The Applicant relied on a declaration from the attorney who prepared the application to establish diligence. The evidence submitted along with the inventor's declaration to establish conception included seven pages of notes and sketches from an inventor's notebook, a corporate invention disclosure form, and results from a computer simulation.

In the final Office Action, the Examiner alleged that the evidence did not show conception of the claimed depth relationship ("first and second field plates having a first vertical depth that is less than 20% of the first vertical depth"). Specifically, the Examiner alleged that:
"No teaching has been found in the Exhibits predating November 16, 2000, of said range. To the extent the Figures are of true scale, – and there is no statement on that either, the range appears not to be met by the figure illustrating the final structure, i.e., Figure 5K, in which the second vertical depth appears to be 25% instead of less than 20%."

The Appeal Brief argued against the Examiner's position by pointing to specific pages and figures in the three evidence documents and explaining how the claimed 20% range was described in these pages. After explaining the relevant portions of the evidence, the Appeal Brief concluded this argument as follows:
The evidence contained in the Declaration under 37 CFR 1.131 therefore clearly establishes the dimensional relationship recited in the relevant claims; namely, the vertical depth (i.e., length) of the gate members (3 pm) is less than 20% of the vertical depth of the field plate members (47 pm = Ld - TBox). Applicant respectfully submits that the range recited in claims 43-44 is fully supported in the Exhibits. Consequently, Baliga '372 should be removed from consideration as a prior art reference.

The Board did not discuss the showing of diligence, and instead moved directly to a discussion of whether the inventor declaration established conception of the claimed relationship between structures, namely, "first and second field plates having a first vertical depth that is less than 20% of the first vertical depth."

The Board found that the declaration was not sufficient. Where the Examiner took issue with the numeric ratio (less than 25% rather than less than 20%), the Board took issue with the terminology used to describe the dimensions. Specifically, the evidence referred to a vertical trench that was 3 um long, where the claim referred to the depth of the plates in the trench. The Board explained that:
The Rule 131 declaration submitted by Appellant to antedate the November filing date of the Baliga ‘372 reference clearly shows a gate poly and a field plate poly, but does not show a depth of the gate members that is less than 20% of another vertical depth (FF4, referring to the figure below showing a gate poly and a field plate poly, and the explanation “Added Vertical (trench) Gate 3μm Long; with Pbody 2.5 μm long, N+ Source 0.2 μm long”).
A measurement that is “long” is not an indication of depth (FF 4). Accordingly, we find that Appellant’s declaration does not prove that he invented the claimed vertical depths prior to the date of the reference to Baliga ‘372.


My two cents: When was the last time you wrote claims and didn't change the terms used by the inventor? That's a large part of what we patent attorneys/agents get paid for ... picking the right words. So I gotta believe this mismatch in terminology will be a common occurrence when you submit inventor-provided evidence with a swear-behind declaration.

The lesson here is not to ignore the discrepancy. Instead, you should explain it. It seems to me that dimensions in particular are easy to explain: depending on what your perspective is, length could also be considered width or depth.

From what I've seen, your best chance is to include the explanation of the discrepancy in the inventor declaration. You can try putting it in as a argument, and you might convince the Examiner that way. But if you go that route on appeal, you risk the Board ignoring your arguments because "[a]rgument of counsel cannot take the place of evidence lacking in the record" (Meitzner v. Mindick, 549 F.2d 775, 782 (CCPA 1977)).

I also find it significant that the Board did not question the sufficiency of the showing of diligence. I've seen plenty of Board decisions that didn't reach the merits of whether the evidence showed conception / reduction because diligence was lacking. Therefore, I infer that there was nothing obviously wrong with the diligence showing. Furthermore, neither the Examiner nor the Board questioned the sufficiency of the evidence in showing any of the other claim limitations –  only the 20% limitation seemed to be an issue.

It's true that the Board found that this evidence had a hole in it, and you should take note of this. Nonetheless, I think this swear-behind was still a pretty good showing overall. Consider adding this application to your list of example swear-behind declarations – it's available in PAIR.