Trials@uspto.gov
`571-272-7822
`
`
`
`
`
`
`
`Paper No. 35
`Entered: March 8, 2017
`
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`____________
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`____________
`
`KARL STORZ ENDOSCOPY-AMERICA, INC.,
`Petitioner,
`
`v.
`
`NOVADAQ TECHNOLOGIES, INC.,
`Patent Owner.
`____________
`
`Case IPR2015-01847
`Patent 7,420,151 B2
`____________
`
`
`
`
`
`Before MICHAEL W. KIM, JENNIFER S. BISK, and
`DANIEL N. FISHMAN, Administrative Patent Judges.
`
`FISHMAN, Administrative Patent Judge.
`
`FINAL WRITTEN DECISION
`35 U.S.C. § 318(a) and 37 C.F.R. § 42.73
`
`
`
`
`

`

`I.
`
`
`
`IPR2015‐01847
`
`Patent 7,420,151 B2
`
`
`
`INTRODUCTION
`Background
`A.
`Karl Storz Endoscopy-America, Inc. (“Petitioner”) filed a Petition
`(Paper 1, “Pet.”) for inter partes review of claims 1–17 of U.S. Patent No.
`7,420,151 B2 (Ex. 1001) (“the ’151 patent”) pursuant to 35 U.S.C. §§ 311–
`319. Novadaq Technologies, Inc. (“Patent Owner”) filed a Patent Owner’s
`Preliminary Response (Paper 6, “Prelim. Resp.”). On March 10, 2016,
`based on the record before us at the time, we instituted an inter partes
`review of all claims (1–17) (Paper 7, “Dec.”). We instituted the review on
`the following challenges to the claims:
`
`References
`
`Yabe1
`
`Krauter2
`
`Basis
`
`§ 103(a)
`
`Claims
`challenged
`
`1–17
`
`§ 102(b)
`
`1, 7, 10, 12, 14
`
`Dec. 22.
`After we instituted this review, Patent Owner filed a Patent Owner
`Response (Paper 11, “PO Resp.”)3 and Petitioner filed a Reply (Paper 15,
`“Pet. Reply”). Petitioner relies on the Declaration (Ex. 1011) and Rebuttal
`
`
`1 U.S. Patent No. 4,885,634; Dec. 5, 1989. Ex. 1007 (“Yabe”).
`2 U.S. Patent No. 6,147,705; Nov. 14, 2000. Ex. 1004 (“Krauter”).
`3 We observe that Patent Owner’s Response does not comply with 37 C.F.R.
`§ 42.24(d) by failing to “include a certification stating the number of words
`in the paper.” Petitioner did not object to this error by Patent Owner.
`Pursuant to our authority under 37 C.F.R. § 42.5(b), we hereby waive this
`violation of our rule requiring certification of the word count in Patent
`Owner’s Response. We advise Patent Owner, however, to adhere to our
`rules in any further filings in this, or other matters before the Board.
`
`2
`
`

`

`IPR2015‐01847
`
`
`
`Patent 7,420,151 B2
`
`
`Declaration of Erhan Gunday (Ex. 1018). Patent Owner relies on the
`Declaration of Bruno Jaggi (Ex. 2001).
`Patent Owner filed Observations on the Cross Examination of Reply
`Witness (Paper 25) to which Petitioner responded (Paper 27). We have
`considered the remarks of both parties in these papers in our analysis to
`follow.
`Oral hearing was conducted on December 6, 2016. The record
`contains a transcript of the hearing (Paper 34, “Tr.”)
`We have jurisdiction under 35 U.S.C. § 6. The evidentiary standard is
`a preponderance of the evidence. See 35 U.S.C. § 316(e); see also 37 C.F.R.
`§ 42.1(d). This Final Written Decision is issued pursuant to 35 U.S.C.
`§ 318(a) and 37 C.F.R. § 42.73.
`For the reasons expressed below, we conclude that Petitioner has
`demonstrated by a preponderance of the evidence that claims 1–17 are
`unpatentable.
`
`
`The ’151 patent
`B.
`According to the ’151 patent, medical imaging devices for viewing
`internal body tissue typically illuminate subject tissue with broadband (i.e.,
`white) light and present an image of the illuminated tissue on a display
`monitor device. Ex. 1001, 1:20–28. Later medical developments
`recognized a benefit of viewing internal body tissue using short wavelength
`(e.g., blue and green) illumination of the tissue to, inter alia, better highlight
`blood and blood vessel structures. Id. at 1:29–43. The ’151 patent indicates
`prior known medical imaging devices recognized the benefit of utilizing
`both broadband (e.g., white) illumination and short wavelength (e.g., blue
`
`3
`
`

`

`IPR2015‐01847
`
`
`
`Patent 7,420,151 B2
`
`
`and green) illumination for a physician, and suggests prior medical imaging
`devices provide such a capability as a broadband spectrum illumination
`source with associated movable filters. Id. at 1:44–59.
`The ’151 patent discloses and claims a medical imaging device that
`uses a single light source for a full spectrum white light imaging mode as
`well as for short wavelength imaging mode, “but does not to [sic] require the
`incorporation and movement of filters in the light source to produce the light
`for the two different imaging modes.” Id. at 1:66–2:2. Light reflected from
`a single light source is sensed by a color image sensor, which may be, for
`example, “an RGB [(red, blue, and green)] type image sensor having a
`number of pixels that are covered with a mosaic filter that passes light in the
`red, green, or blue spectral bands,” (Id. at 3:41–44) or, for example, “a
`complimentary color filter mosaic such as a CMYG (cyan, magenta, yellow,
`and green)” (Id. at 4:45–47). An image processor of the ’151 patent reduces
`a contribution of red illumination, thereby generating a short wavelength
`false image, by calculating values for display pixels stored in a memory
`based on sensed values of the color image sensor. See id. at 4:8–12, 6:60–
`7:3, 7:63–66.
`Figure 1 of the ’151 patent is reproduced below.
`
`
`
`4
`
`

`

`IPR2015‐01847
`
`Patent 7,420,151 B2
`
`
`
`
`Figure 1 of the ’151 patent, reproduced above, discloses an exemplary
`imaging system in which the subject matter of the ’151 patent may be
`employed. Light source 20 illuminates body tissue through scope 10 and
`reflected light from the illuminated tissue is returned to image processor 30
`for presentation on display 40. See Ex. 1001, 3:14–29.
`Figure 2C of the ’151 patent shows an exemplary embodiment of
`processing performed within the image processor of Figure 1.
`
`Figure 2C of the ’151 patent, reproduced above, shows RGB color
`image sensor 62 producing RGB signal values used by the image processor
`to determine (e.g., “calculate”) display pixel values (B1, G1, Cy1) in
`memory 72, 74, 76 for presentation on display 78 as a pixel with reduced red
`
`
`
`5
`
`

`

`IPR2015‐01847
`
`Patent 7,420,151 B2
`
`
`contribution (P1) to generate a short wavelength false image. See Ex. 1001,
`4:12–42.
`
`
`
`
`Related Matters
`B.
`Both parties indicate there are no related matters. Pet. 1; Paper 5, 2.
`
`
`Illustrative Claim
`C.
`Independent claim 1, reproduced below, is exemplary of the
`invention:
`
`1. A system for producing images of tissue with a medical
`device that delivers an illumination light to a body cavity and a
`color image sensor that produces images of the tissue from a
`number of pixels that are sensitive to different wavelengths of
`light, comprising:
`
`an image processor coupled to receive signals produced by
`the color image sensor in response to illumination light reflected
`from the tissue having red, green, and blue color components,
`wherein, the image processor calculates image signals that are
`stored in a memory by minimizing the contribution from signals
`produced by the image sensor in response to red illumination
`light.
`
`Ex. 1001, 9:2–14.
`
`
`II. ANALYSIS
`Claim Construction
`A.
`In an inter partes review, a claim in an unexpired patent shall be given
`its broadest reasonable construction in light of the specification of the patent
`in which it appears. 37 C.F.R. § 42.100(b); see also Cuozzo Speed Techs.,
`LLC v. Lee, 136 S. Ct. 2131, 2142 (2016) (affirming that USPTO has
`
`6
`
`

`

`IPR2015‐01847
`
`
`
`Patent 7,420,151 B2
`
`
`statutory authority to construe claims according to 37 C.F.R. § 42.100(b)).
`Under the broadest reasonable construction standard, claim terms are given
`their ordinary and customary meaning, as would be understood by one of
`ordinary skill in the art in the context of the entire disclosure. In re
`Translogic Tech., Inc., 504 F.3d 1249, 1257 (Fed. Cir. 2007). “[A] claim
`construction analysis must begin and remain centered on the claim language
`itself.” Innova/Pure Water, Inc. v. Safari Water Filtration Systems, Inc., 381
`F.3d 1111, 1116 (Fed. Cir. 2004). “Though understanding the claim
`language may be aided by the explanations contained in the written
`description, it is important not to import into a claim limitations that are not
`a part of the claim.” SuperGuide Corp. v. DirecTV Enters., Inc., 358 F.3d
`870, 875 (Fed. Cir. 2004). Furthermore, only those terms that are in
`controversy need to be construed, and only to the extent necessary to resolve
`the controversy. See Vivid Techs., Inc. v. Am. Sci. & Eng’g, Inc., 200 F.3d
`795, 803 (Fed. Cir. 1999).
`
`“Image Sensor,” “RGB Sensor,” “CMYG Sensor”
`1.
`Independent claim 1 recites, “a color image sensor that produces
`images of the tissue from a number of pixels that are sensitive to different
`wavelengths of light.” Independent claim 10 similarly recites, “an image
`sensor that receives reflected light from the tissue sample, the image sensor
`having a number of pixels sensitive to different wavelengths of light and
`which generate image signals in response to the light received from the
`tissue sample.” Dependent claims 2–6 and 13 narrow the scope of the image
`sensor to an “RGB sensor.” Dependent claims 7–9 and 14 narrow the scope
`of the image sensor to a “CMYG sensor.”
`
`7
`
`

`

`IPR2015‐01847
`
`Patent 7,420,151 B2
`
`
`
`Petitioner proposes the broadest reasonable interpretation of “color
`image sensor” or “image sensor” as: “an arrangement comprising an image
`sensor and at least one color filter, where the image sensor’s pixels receive
`light that passes through the color filter.” Pet. 12 (emphasis omitted).
`Petitioner contends this construction is consistent with the claims and
`encompasses several types of sensors known in the art at the time of the
`’151 patent. Pet. 13. In particular, Petitioner’s proposed construction
`encompasses “RGB (rotary filter) sensors.” Id. Petitioner next argues the
`specification does not narrow the construction of the term but, instead,
`merely provides examples of known color image sensors including a CMYG
`color image sensor and an RGB color image sensor. Id.
`In the Preliminary Response, Patent Owner argues Petitioner’s
`proposed construction is unreasonably broad and, in particular, is
`inconsistent with the specification, which specifically distinguishes
`previously known apparatus that use movable filters which cause the same
`color light to fall on every pixel of the image sensor. Prelim. Resp. 8–10
`(citing Ex. 1001, 1:44–59, 1:63–2:1). Furthermore, Patent Owner argues
`Petitioner’s proposed construction is inconsistent with the claim, per se,
`requiring that the sensor “produce images from, or have, a number of pixels
`that are sensitive to different wavelengths of light.” Prelim. Resp. 10.
`Patent Owner contends this is only possible if the image sensor has at least
`two different color filters on its surface. Id.
`In our Decision on Institution, we determined an image sensor, as
`recited in the claims, is a device that senses incident light on a plurality of
`pixels, at least two of which are sensitive to different wavelengths of incident
`light. Dec. 12. Further, consistent with the Specification of the ’151 patent,
`
`
`
`8
`
`

`

`IPR2015‐01847
`
`
`
`Patent 7,420,151 B2
`
`
`we determined an RGB sensor, as recited in the claims, is an image sensor
`having one or more pixels that are sensitive to red light, one or more pixels
`that are sensitive to green light, and one or more pixels that are sensitive to
`blue light. Id. Similarly, we determined a CMYG sensor, as recited in the
`claims, is an image sensor having one or more pixels that are sensitive to
`cyan light, one or more pixels that are sensitive to magenta light, one or
`more pixels that are sensitive to yellow light, and one or more pixels that are
`sensitive to green light. Id. The analytical basis for our constructions was as
`follows:
`The express language of independent claims 1 and 10 makes
`clear that an image sensor must have or use a plurality of pixels
`that respond to different wavelengths of light. The exemplary
`embodiments of the ’151 patent are consistent with that claim
`language, in that the specification discusses the use of an “RGB
`color image sensor having pixels that are sensitive to red, green,
`and blue light” (Ex. 1001, 2:9–10) and “a CMYG color image
`sensor . . . [having] pixels that are sensitive to complementary
`colors (cyan, magenta, yellow, and green)” (id. at 2:20–23).
`Both these exemplary sensor embodiments utilize mosaic filters
`coupled with the sensors such that each pixel has an associated
`filter determining the wavelengths of light incident upon the
`corresponding pixel, and at least two of those filters have
`different spectral bands/colors that are passed. Id. at 3:40–44,
`4:43–47. Thus, for a construction of “image sensor” to be
`consistent with the claims and the specification, we are
`persuaded that the construction must be limited to sensors having
`a plurality of pixels, at least some of which are sensitive to
`different wavelengths of light (i.e., different colors) than at least
`some of the other pixels, such as by use of a mosaic filter in front
`of a CCD sensor array.
`that a proper
`By
`implication, we are persuaded
`construction consistent with the claims and the specification
`would exclude a sensor structure in which all pixels of the sensor
`respond to the same wavelengths of light. For example, the
`
`9
`
`

`

`IPR2015‐01847
`
`Patent 7,420,151 B2
`
`
`
`admitted prior art techniques identified in the specification (Ex.
`1001, 1:44-59) provide that moving filters that pass a single color
`at a time are placed in front of the light source such that the color
`of reflected light is incident upon each pixel of the sensor (i.e., a
`CCD sensor). Thus, in such admitted prior art techniques, each
`pixel of such a sensor is sensitive to the same wavelength, which
`is typically any photon or “white” light, but is in any case a
`monochromatic reflected light that is based on the spectral band
`of the movable filter presently positioned in the path between the
`tissue sample and the illumination source.
`Dec. 11–12.
`In its Patent Owner Response, Patent Owner argues that our use of the
`word “having” renders unclear whether the above construction is intended to
`be “open-ended, allowing the image sensor to include pixels that are
`sensitive to colors other than the three specified in the constructions.” PO
`Resp. 4. Patent Owner contends the terms RGB sensor and CMYG sensor
`had well-understood meanings to ordinarily skilled artisans at the time of
`filing of the ’151 patent. Id. (citing Ex. 2001 ¶ 79). Specifically, Patent
`Owner asserts that an RGB sensor was understood to include only pixels
`sensitive to red, blue, and green and no other colors, and that a CMYG
`sensor was understood to include only pixels sensitive to cyan, magenta,
`yellow, and green and no other colors, and, thus, urges us to modify our
`above constructions to reflect the same. Id. at 4–5 (citing Ex. 2007, 18:19–
`20:3). We decline to do so. Other than Mr. Jaggi’s unsupported assertion
`(Ex. 2001 ¶ 79), Patent Owner offers no evidence in support of its assertion
`that the ordinarily skilled artisan would understand “RGB sensor” and
`“CMYG sensor” as limited only to the primary colors of the corresponding
`filters. Patent Owner does not identify any teaching of the ’151 patent that
`requires such a narrow reading of the terms. To the contrary, as noted by
`
`
`
`10
`
`

`

`IPR2015‐01847
`
`
`
`Patent 7,420,151 B2
`
`
`Mr. Gunday, RGB and CMYG sensors that were sensitive to additional
`colors were known at the time of the ’151 patent filing. Ex. 1018 ¶ 23
`(citing Ex. 1007, Fig. 11 (disclosing a sensor that combines both RGB and
`CMYG pixels)); see also Pet. Reply 1–2 (agreeing with the Board’s
`preliminary constructions). Thus, we perceive no lack of clarity in our
`constructions and emphasize that our constructions of “RGB sensor” and
`“CMYG sensor” do not limit such sensors to only the three (RGB) or four
`(CMYG) types of pixels.
`For the above reasons, we perceive no reason to modify our
`constructions of the terms “RGB sensor” and “CMYG sensor” in light of the
`record developed at trial.
`
`
`2.
`
`“Calculates” Image Signals by Minimizing Red Light Contribution
`Independent claim 1 recites “calculates image signals that are stored
`in a memory by minimizing the contribution from signals produced by the
`image sensor in response to red illumination light.” Petitioner does not
`propose a construction of this phrase in its Petition. Patent Owner argues we
`should construe the word “calculates” as “performing a mathematical
`manipulation.” PO Resp. 5 (citing Mr. Jaggi’s Declaration, Ex. 2001 ¶ 81
`(which, in turn, relies on Ex. 2005, an online dictionary definition4)).
`
`
`4 We observe Exhibit 2005, the online dictionary Mr. Jaggi relies upon in
`opining on a definition of “calculates,” includes other definitions, such as,
`“to determine by reasoning, common sense, or practical experience” and “to
`make suitable or fit for a purpose; adapt.” Ex. 2005. Mr. Jaggi does not
`explain his basis for selecting one of the multiple definitions as evidence of
`the understanding of the ordinarily skilled artisan and, thus, we accord little
`weight to this aspect of Mr. Jaggi’s Declaration. See Ex. 2001 ¶ 81.
`
`11
`
`

`

`IPR2015‐01847
`
`
`
`Patent 7,420,151 B2
`
`
`Furthermore, Patent Owner contends the calculated signals must include
`green, blue, and cyan, and further contends, “[e]very embodiment in the
`’151 patent also calculates blue, green, and cyan image signals in order to
`minimize the contribution from signals in response to red light.” PO Resp.
`5–6. Based on this interpretation of “calculates,” Patent Owner contends the
`phrase, “‘calculates image signals . . . by minimizing the contribution from
`signals produced by the image sensor in response to red illumination light’
`means ‘computing green, blue, and cyan image signals, resulting in
`minimizing the contribution from components of light with wavelengths
`over 600 nm.’” PO Resp. 8 (citing Ex. 2001 ¶ 91). Petitioner replies that,
`for a variety of reasons, Patent Owner’s proposed construction is unduly
`narrow and concurs with our interpretation in our Decision on Institution.
`Pet. Reply 2–4.
`We are disinclined to adopt Patent Owner’s proposed construction of
`this phrase, as recited in claim 1, to require mathematical manipulation.
`Claim 1 recites “calculates” in a self-defining manner, specifically reciting
`calculating the image signals “by minimizing the contribution from signals
`produced by the image sensor in response to red illumination light.” Thus,
`claim 1 is clear on its face that the calculation to be performed is by
`minimizing the contribution from red light. Therefore, our analysis shifts to
`determining the meaning of “minimizing” as recited in claim 1.
`The ’151 patent discloses a variety of embodiments for “minimizing”
`the contribution of red light.5 For example, in support of the Patent Owner’s
`
`
`5 Additionally we observe that “minimizing” appears only once in the
`’151 patent—in claim 1 (and, thereby, also in its dependent claims 2–9).
`
`12
`
`

`

`IPR2015‐01847
`
`
`
`Patent 7,420,151 B2
`
`
`construction, the ’151 patent does disclose exemplary embodiments that
`minimize red light contribution utilizing mathematical manipulations
`including, for example, CMYG filter computations that are “considered to
`be well known to those of ordinary skill in the art” (Ex. 1001, 4:66–7:59)
`and averaging blue and green signals to “compute” a cyan signal (id. at
`4:21–24). The ’151 patent, however, also specifically recites,
`Because the passbands of the red mosaic filters do not
`significantly overlap with the pass bands of the other filters for a
`short wavelength imaging mode, the contribution of the image
`signals due to red illumination light can be reduced or largely
`eliminated by not assigning the image signals produced by image
`sensor pixels that are sensitive to red light to their corresponding
`display pixels.
`Id. at 4:5–12 (emphasis added). The ’151 patent further states “a short
`wave-length image (or the color components of such an image) can be
`computed from a subset of image sensor signals (i.e. excluding the signal
`data from red light).” Id. at 8:29–32 (emphasis added). Thus, the
`’151 patent also encompasses the contribution of red light in the image being
`
`
`Claim 10 includes a related recitation using the phrase “substantially
`eliminating” in reference to contribution from red light. The’151 patent uses
`other phrases in reference to the contribution of red light, including,
`“reduces” (Ex. 1001, Abstract), “substantially eliminate” (id. at 2:24),
`“remove or reduce” (id. at 3:9), “reduced or largely eliminated” (id. at 4:9),
`“substantially reduced or eliminated” (id. at 6:63), “substantially reduced”
`(id. at 7:65), “eliminate” (id. at 8:9), and “substantially eliminating” (id. at
`8:42). At oral hearing, Patent Owner’s counsel acknowledged Patent Owner
`does not propose a different interpretation of these various phrases. Tr.
`40:16–17. Thus, we determine that “minimize,” “reduce,” “eliminate,”
`various root extensions of these words, and combinations of these words
`with and without the adverb “substantially,” are considered synonymous in
`the ’151 patent.
`
`13
`
`

`

`IPR2015‐01847
`
`
`
`Patent 7,420,151 B2
`
`
`“reduced or largely eliminated” in an image (i.e., “minimized”), by simply
`disregarding the red signal value in determining the pixels of the displayed
`image (i.e., “not assigning” the pixels sensing red to the corresponding
`display pixels or “excluding” the red pixels).
`Therefore, we construe “calculates image signals that are stored in a
`memory by minimizing the contribution from signals produced by the image
`sensor in response to red illumination light” as encompassing mathematical
`manipulations, as well as non-mathematical techniques, that “minimize the
`contribution from signals produced by the image sensor in response to red
`illumination light.”6
`
`
`“Memory”
`3.
`Claim 1 recites, inter alia, that the “calculated” signal values “are
`stored in a memory.” In our Decision on Institution, we determined, in our
`analysis of the prior art grounds, that “[n]othing in claim 1 requires a
`particular type of memory for storing the calculated image signals nor a
`particular location for such a memory.” Dec. 15–16. Patent Owner argues
`that although the arguments pre-institution focused on where the memory
`was located in the claimed structures, “[a] separate issue, however, is the
`fact that the term ‘memory’ as used in the claims, must be ‘display
`memory.’” PO Resp. 8–9. Patent Owner contends “memory,” as recited in
`
`
`6 This construction is consistent with that alluded to in the analysis of the
`prior art grounds in the Decision on Institution, where we determined that
`the aforementioned claim limitations requires minimizing red light
`contribution, but does not require any particular method for minimizing the
`contribution of red light in the generated image. See Dec. 16, 19; see also
`Pet. Reply 2 (asserting the same).
`
`14
`
`

`

`
`
`IPR2015‐01847
`
`Patent 7,420,151 B2
`
`
`claim 1, means “display memory,” because the only memory referred to in
`the Specification of the ’151 patent is “display memory.” Id. at 9. Patent
`Owner further contends the recited memory must be a display memory
`including a “frame buffer that stores the processed image data for scanning
`to a monitor for real time display,” because a physician would need to view
`real-time images in endoscopic applications, and a display memory frame
`buffer “was the only type of memory capable of achieving such real-time
`display.” Id. at 10 (citing Ex. 2001 ¶ 95). Thus, Patent Owner concludes
`“memory” as recited in claim 1 is a “display memory.” Id.
`We do not adopt Patent Owner’s interpretation. Although the claims
`are interpreted consistent with the specification, we decline to import
`exemplary embodiments from the specification as limitations in the claims.
`See SuperGuide, 358 F.3d at 875. Nothing in the ’151 patent discusses
`real-time display of a frame as argued by Patent Owner. All that is required
`of the “memory” recited in claim 1 is a memory capable of storing the
`calculated signals (i.e., the signals determined mathematically or otherwise
`to minimize the contribution of red light). Because claim 1 only requires
`storing the calculated values, it is presumed that a wide variety of memory
`would meet that claim limitation.
`Another aspect of “memory” at issue here is whether the term should
`be interpreted to broadly encompass an analog “memory” device (such as
`analog buffers as discussed infra). This is issue is relevant because Krauter
`(Ex. 1004), as discussed below, performs certain calculations to process
`pixels of an image and, after processing the pixel values digitally, converts
`the digital values to analog signals. The analog signals are applied to an
`
`15
`
`

`

`IPR2015‐01847
`
`
`
`Patent 7,420,151 B2
`
`
`analog “buffer,” which, in turn, applies the analog signal value to a display
`monitor.
`In applying Krauter, Petitioner argues such an analog buffer may be
`considered “memory” because it stores data—even if only temporarily. See
`Pet. 44 (“The image signals that are calculated by the DSP [a]re stored in
`memory ‘buffers’ for display on a monitor.”); see also Ex. 1011 ¶ 264 (“It is
`common knowledge that buffers are a type of memory.”). In his deposition,
`Mr. Gunday testified,
`Q[:] But what’s described as an analog buffer is not a
`memory, right?
`A[:] Could be considered as a memory. There’s analog
`memories that will hold a value for -- you know.
`Q[:] Well, what do you understand this Buffer 33 to be
`doing?
`A[:] It’s holding the analog value to go out to a monitor.
`Q[:] And you describe that as memory?
`A[:] I can, sure. Buffer is a memory.”
`Ex. 2007, 57:10–19
`Patent Owner responds by arguing Krauter’s buffers are not memory
`because they store analog data and, by contrast, the ordinarily skilled artisan
`would understand “memory” as digital memory (i.e., storing digital data
`rather than analog data). PO Resp. 46–48 (citing Mr. Gunday’s deposition
`testimony Ex. 2007, 57:20–58:1 (“Q[:] Well, isn't it true that as -- using --
`one skilled in the art, if you hear the term “memory,” you think about a
`digital memory? A[:] Sure. I agree with that.”). At oral hearing Patent
`Owner emphasized this point stating,
`
`16
`
`

`

`
`
`IPR2015‐01847
`
`Patent 7,420,151 B2
`
`
`
`JUDGE BISK: I think that’s true because I think most
`memory is digital, but I’m not sure that it leads to your
`conclusion that analog buffer is not.
`MR. KREEGER: Well, it’s not just what Mr. Jaggi’s bare
`testimony. He explains that what the analog buffer does is it does
`not actually store the value. It passes through it transiently for a
`very brief moment of time, as it’s true for anywhere within the
`circuit as a whole. If the analog buffer counts as a memory, then
`every portion of this circuit is a memory.
`Because as the signal passes through the circuit, it will
`transiently pass through that in a moment in time, but one of skill
`in the art would not consider that a memory and it’s not a memory
`and it’s quite different from the other sorts of components.
`JUDGE BISK: So how long does it have to stay to be a
`memory?
`MR. KREEGER: Well, it has to be stored for some period
`of time and we submit that as used in this patent and as used in
`the art, it would have to be a digital memory to be stored for a
`nontrivial portion of time. This is not that. This buffer is not for
`that purpose. It’s not a memory.
`Paper 34, 35:22–36:15.
`Although the ’151 patent does not address “analog” or “digital” in
`reference to “memory,” we agree with Patent Owner, based primarily on the
`cross-examination testimony of Petitioner’s expert, Mr. Gunday, that the
`ordinarily skilled artisan at the time of the ’151 patent filing would have
`understood “memory,” in the context of the ’151 patent, to be referring to
`digital memory rather than analog buffers. The signals stored in Krauter’s
`analog buffers are transitory, analog signals propagating from circuits that
`calculate a value, through the analog buffer, to an analog input of a display
`monitor. We are persuaded that an ordinarily skilled artisan would not have
`considered such analog buffers to be a memory in the context of the ’151
`patent.
`
`17
`
`

`

`IPR2015‐01847
`
`Patent 7,420,151 B2
`
`
`
`Thus, we determine “memory,” as recited in claim 1, means any
`digital memory capable of storing image signals that minimize the
`contribution of red light.
`
`
`
`
`“Sensitive” and “Primarily Sensitive”
`4.
`Patent Owner observes claim 3 recites pixels “sensitive” to certain
`colors and claim 7 recites pixels “primarily sensitive” to certain colors. PO
`Resp. 11. Patent Owner then argues “a person of ordinary skill in the art
`would have understood the term ‘sensitive to’ light of a particular color to
`mean ‘primarily sensitive to’ the light of that color.” Id. (citing Ex. 2001
`¶¶ 96–99). Petitioner responds that Patent Owner’s proposed interpretation
`should be rejected because “sensitive” is a broader term than “primarily
`sensitive.” Pet. Reply 5. Petitioner further asserts “while a pixel in a color
`image sensor may be sensitive to more than one color of light, it is primarily
`(i.e. mostly) responsive to one color of light.” Id. at 6.
`The doctrine of claim differentiation would normally give rise to a
`presumption that “primarily sensitive,” as recited in dependent claim 7, is
`narrower than “sensitive” as recited in its base claim 1. We observe,
`however, claim 2 recites “primarily sensitive” and depends from claim 1,
`which recites “sensitive.” Thus, claim differentiation would again support a
`presumption that “primarily sensitive” (in claim 2) is narrower than
`“sensitive” (in claim 1). But claim 3 recites “sensitive” and depends from
`claim 2, which recites the presumably narrower “primarily sensitive,” giving
`rise to the opposite presumption under the claim differentiation doctrine.
`Therefore, the claim differentiation doctrine does not aid us in determining a
`difference between these two terms.
`
`18
`
`

`

`IPR2015‐01847
`
`Patent 7,420,151 B2
`
`
`
`
`
`We further observe that “primarily sensitive” does not appear in the
`Specification of the ’151 patent. Still further, we observe that claim 2,
`dependent from claim 1 and from which claim 3 depends, uses both
`“primarily sensitive” and “sensitive” in reference to the same blue and green
`pixels.
`Thus, it appears the ’151 patent intended no distinction between
`“sensitive” and “primarily sensitive.” Therefore, we are unable to identify
`any basis for interpreting “primarily sensitive” as meaning anything different
`than “sensitive” in the context of the ’151 patent claims. Furthermore, we
`agree with Mr. Jaggi that a pixel being “sensitive” to a color should be
`understood to mean the pixel is mostly sensitive to a particular color (a range
`of the spectrum) but not to the exclusion of some degree of sensitivity to
`other colors. See Ex. 2001 ¶¶ 97–98.
`We, therefore, interpret “sensitive” and “primarily sensitive” to be
`synonymous in the context of the ’151 patent.
`
`5.
`
`Producing a “Short Wavelength Image . . . by Substantially
`Eliminating a Contribution of Red Light”
`Independent claim 10 recites, in part, “wherein the short wavelength
`image of the tissue is produced by substantially eliminating a contribution of
`red light in the set of image signals.” Based on exemplary embodiments in
`the ’151 patent (PO Resp. 11–13), Patent Owner argues this phrase should
`be interpreted as “forming an image from calculated green, blue, and cyan
`signals, thereby substantially eliminating the contribution from components
`of light with wavelengths over 600 nm” (PO Resp. 13 (citing Ex. 2001
`¶ 103)).
`
`19
`
`

`

`IPR2015‐01847
`
`Patent 7,420,151 B2
`
`
`
`Petitioner argues, and we agree, Patent Owner’s argument unduly
`narrows the aforementioned phrase to require calculation of green, blue and
`cyan signals to effect the substantial elimination of red light. Pet. Reply 6–
`7. In particular, analogous to our discussion supra (section II.A.2 regarding
`“calculates . . . by minimizing,” as recited in claim 1), claim