IN THE UNITED STATES PATENT AND TRADEMARK OFFICE
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`
`
`Huawei Device Co., Ltd.,
`Petitioner,
`
`
`v.
`
`
`Maxell, Ltd.,
`Patent Owner.
`
`
`Case No. To Be Assigned
`Patent No. 7,671,901
`
`
`
`PETITION FOR INTER PARTES REVIEW OF U.S. PATENT NO. 7,671,901
`UNDER 35 U.S.C. §§311-319 AND 37 C.F.R. §42.100 et seq.
`
`
` DC: 6579265-1
`
`

`

`Exhibit
`Ex. 1001
`Ex. 1002
`Ex. 1003
`
`Ex. 1004
`
`Ex. 1005
`Ex. 1006
`
`Ex. 1007
`Ex. 1008
`
`Ex. 1009
`
`Ex. 1010
`
`Ex. 1011
`
`Ex. 1012
`
`Ex. 1013
`
`Ex. 1014
`
`Ex. 1015
`Ex. 1016
`
`
`
`
`
`
`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`LIST OF EXHIBITS
`
`Description
`U.S. Patent No. 7,671,901 (the “’901 Patent”)
`File History for U.S. Patent No. 7,671,901
`Translation of Japanese Patent Application Publication No.
`2003-337580 (“Kitazawa”)
`Japanese Patent Application Publication No. 2003-337580
`(“Kitazawa”)
`U.S. Patent No. 5,068,718 (“Iwabe”)
`Translation of Japanese Patent Application Publication No. 6-
`303551 (“Yagi”)
`Japanese Patent Application Publication No. 6-303551 (“Yagi”)
`U.S. Patent Application Publication No. 2004/0001165
`(“Shiota”)
`P.R. 4-3 Joint Claim Construction and Prehearing Statement,
`Hitachi Maxell, Ltd. v. Huawei Device USA Inc. et al., 5:16-cv-
`00178-RWS (E.D. Tex. Sept. 1, 2017) (Dkt. 74)
`Plaintiff Hitachi Maxell, Ltd.’s Opening Claim Construction
`Brief, Hitachi Maxell, Ltd. v. Huawei Device USA Inc. et al.,
`5:16-cv-00178-RWS (Oct. 2, 2017) (Dkt. 95)
`Defendants Huawei Device USA Inc., Huawei Device Co., Ltd.,
`and ZTE USA Inc.’s Claim Construction Brief in Response,
`Hitachi Maxell, Ltd. v. Huawei Device USA Inc. et al., 5:16-cv-
`00178-RWS (Oct. 23, 2017) (Dkt. 100)
`Plaintiff Maxell, Ltd.’s Reply Claim Construction Brief, Hitachi
`Maxell, Ltd. v. Huawei Device USA Inc. et al., 5:16-cv-00178-
`RWS (Oct. 30, 2017) (Dkt. 106)
`Unopposed Motion to Substitute Plaintiff Maxell, Ltd. for Hitachi
`Maxell, Ltd., Hitachi Maxell, Ltd. v. Huawei Device USA Inc. et
`al., 5:16-cv-00178-RWS (Oct. 24, 2017) (Dkt. 101)
`Order Granting Unopposed Motion to Substitute Plaintiff Maxell,
`Ltd. for Hitachi Maxell, Ltd., Hitachi Maxell, Ltd. v. Huawei
`Device USA Inc. et al., 5:16-cv-00178-RWS (Oct. 26, 2017) (Dkt.
`102)
`Declaration of Robert Louis Stevenson, Ph.D.
`Curriculum vitae of Robert Louis Stevenson, Ph.D.
`
`
`
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`

`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`TABLE OF CONTENTS
`I.
`INTRODUCTION ........................................................................................... 1
`II. MANDATORY NOTICES (37 C.F.R. §42.8(A)(1)) ...................................... 3
`A.
`Real Party-In-Interest (37 C.F.R. §42.8(b)(1)) ..................................... 3
`B.
`Related Matters (37 C.F.R. §42.8(b)(2)) ............................................... 3
`C.
`Lead and Backup Counsel (37 C.F.R. §42.8(b)(3)) .............................. 4
`D.
`Service Information (37 C.F.R. §42.8(b)(4)) ........................................ 4
`FEES (37 C.F.R. §42.103) ............................................................................... 4
`III.
`IV. REQUIREMENTS FOR IPR (37 C.F.R. §42.104) ......................................... 5
`A. Grounds for Standing (37 C.F.R. §42.104(a)) ...................................... 5
`B.
`Citation of Prior Art .............................................................................. 5
`C.
`Claims and Statutory Grounds (37 C.F.R. §§42.104(b)(1) &
`(b)(2)) .................................................................................................... 6
`Person of Ordinary Skill in the Art ....................................................... 6
`Unpatentability of the Construed Claims (37 C.F.R.
`§42.104(b)(4)) ....................................................................................... 7
`Supporting Evidence (37 C.F.R. §42.104(b)(5)) .................................. 7
`F.
`SUMMARY OF THE ’901 PATENT ............................................................. 7
`A. Overview of the Technology ................................................................. 7
`B.
`Overview of the ’901 Patent .................................................................. 8
`1.
`Video Signal Correction ............................................................. 9
`2.
`Image Processing Apparatus .....................................................10
`3.
`Correction of Luminance ..........................................................18
`Challenged Claims ..............................................................................23
`
`D.
`E.
`
`V.
`
`C.
`
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`D.
`E.
`
`Prosecution History Summary of the ’901 Patent ...............................24
`Claim Construction (37 C.F.R. §42.104(b)(3)) ...................................24
`1.
`“when any change occurs in the video signal inputted to the
`input portion” / “when the change of the video signal does not
`occur and when the illumination detected by the illumination
`sensor is above a predetermined value” (claim 1) ....................25
`VI. THERE IS A REASONABLE LIKELIHOOD THAT PETITIONER
`WILL PREVAIL WITH RESPECT TO AT LEAST ONE CLAIM OF
`THE ’901 PATENT .......................................................................................26
`A.
`Prior Art ...............................................................................................26
`1.
`Japanese Patent Application Publication No. 2003-337580 to
`Kitazawa (Exs. 1003-04) ..........................................................26
`U.S. Patent No. 5,068,718 to Iwabe (Ex. 1005) .......................37
`Japanese Patent Application Publication No. 6-303551 to Yagi
`(Exs. 1006-07) ...........................................................................39
`U.S. Patent Application Publication No. 2004/0001165 to
`Shiota et al. (Ex. 1008) .............................................................42
`Ground I: Claims 1 and 2 Are Unpatentable Under 35 U.S.C.
`§103 as Obvious over the Combination of Kitazawa and Iwabe ........44
`1.
`Claim 1 ......................................................................................44
`2.
`Claim 2 ......................................................................................70
`Ground II: Claims 1 Is Unpatentable Under 35 U.S.C. §103 as
`Obvious over the Combination of Yagi and Shiota .............................75
`1.
`Claim 1 ......................................................................................75
`D. Ground III: Claim 2 Is Unpatentable Under 35 U.S.C. §103 as
`Obvious over the Combination of Yagi, Shiota, and Iwabe ................87
`1.
`Claim 2 ......................................................................................87
`VII. CONCLUSION ..............................................................................................91
`
`B.
`
`C.
`
`2.
`3.
`
`4.
`
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`TABLE OF AUTHORITIES
`
` Page(s)
`
`Cases
`Cuozzo Speed Techs., LLC v. Lee,
`136 S. Ct. 2131 (2016) ........................................................................................ 24
`KSR Int’l Co. v. Teleflex Inc.,
`550 U.S. 398 (2007) .....................................................................................passim
`Okajima v. Bourdeau,
`261 F.3d 1350 (Fed. Cir. 2001) ............................................................................ 7
`In re Translogic Tech., Inc.,
`504 F.3d 1249 (Fed. Cir. 2007) .......................................................................... 25
`Rules and Statutes
`35 U.S.C. §102(a) .............................................................................................passim
`35 U.S.C. §102(b) .............................................................................................passim
`35 U.S.C. §102(e) ............................................................................................ 5, 8, 37
`35 U.S.C. §103 ..................................................................................................passim
`35 U.S.C. §314(a) .................................................................................................... 26
`37 C.F.R. §42.8(b) ................................................................................................. 3, 4
`37 C.F.R. §42.15(a) .................................................................................................... 4
`37 C.F.R. §42.100(b) ............................................................................................... 24
`37 C.F.R. §42.103 ...................................................................................................... 4
`37 C.F.R. §42.104 ........................................................................................ 5, 6, 7, 24
`
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`

`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`I.
`
`INTRODUCTION
`Huawei Device Co., Ltd. (“Huawei” or “Petitioner”) petitions for Inter
`
`Partes Review (“IPR”) seeking cancellation of claims 1 and 2 of U.S. Patent No.
`
`7,671,901 (Ex. 1001, “the ’901 Patent”), assigned to Maxell, Ltd. (“Patent
`
`Owner”).1
`
`The ’901 Patent generally relates to an image processing apparatus that
`
`corrects video signals for better display. The patent describes that known prior art
`
`apparatus existed for correcting the video signals based on certain characteristics of
`
`the video signals. Ex. 1001, 1:20-25. The ’901 Patent purports to improve the
`
`prior art apparatus by using less power, and improving the image quality when the
`
`environmental illumination is high. Id., 1:26-42.
`
`Claim 1 requires a video signal corrector that corrects the video signal based
`
`on the characteristics of the video signal and based on the level of environmental
`
`illumination when any change occurs in the video signal. When no change occurs
`
`in the video signal, and the level of environmental illumination is above a certain
`
`
`1 Petitioner understands that Maxell, Ltd. is now the assignee of the ’901 Patent,
`
`even though the USPTO’s public assignment database does not currently reflect
`
`this. See Exs. 1013-14.
`
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`value, claim 1 requires correcting the video signal in a more specific way.2
`
`Claim 2 depends from claim 1 and requires that the video signal corrector
`
`correct the video signal to make the dark area of a given image brighter.
`
`All of these elements were well-known in the prior art. For example,
`
`Kitazawa discloses a video display device that corrects the video signal based on
`
`the characteristics of the video signal and based on the level of environmental
`
`illumination when any change occurs in the video signal. When no change occurs
`
`in the video signal, and the level of the environmental illumination is above a
`
`certain value, Kitazawa discloses that the video display device corrects the video
`
`signal in the more specific way, as required by claim 1.
`
`Similarly, Yagi discloses a television receiver that corrects the video signal
`
`based on the characteristics of the video signal and on the level of environmental
`
`illumination when any change occurs in the video signal. When no change occurs
`
`in the video signal, and the level of environmental illumination is above a certain
`
`value, Yagi discloses that the television receiver corrects the video signal in the
`
`more specific way, as required by claim 1.
`
`
`2 This more specific correction requires “correct[ing] luminance of the video signal
`
`without correcting hue and saturation of the video signal.” These concepts are
`
`discussed in more detail in Section V.B, below.
`
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`Shiota discloses an image processing apparatus that corrects the video signal
`
`based on the characteristics of the video signal in a way that closely resembles an
`
`embodiment disclosed in the ’901 Patent.
`
`Iwabe discloses a video signal correction circuit that makes darker areas of a
`
`given image brighter, as required by claim 2.
`
`As discussed in detail below, the combination of Kitazawa and Iwabe
`
`teaches all limitations of claims 1 and 2 of the ’901 Patent. Furthermore, the
`
`combination of Yagi and Shiota teaches all limitations of claim 1 of the ’901
`
`Patent, and the combination of Yagi, Shiota, and Iwabe teaches all limitations of
`
`claim 2 of the ’901 Patent. Therefore, claims 1 and 2 of the ’901 Patent are
`
`unpatentable.
`
`II. MANDATORY NOTICES (37 C.F.R. §42.8(A)(1))
`A. Real Party-In-Interest (37 C.F.R. §42.8(b)(1))
`The real parties-in-interest for this Petition are Huawei Device Co., Ltd.,
`
`Huawei Technologies Co., Ltd., Huawei Device USA Inc., Huawei Investment &
`
`Holding Co., Ltd., Huawei Device (Dongguan) Co., Ltd., Huawei Tech.
`
`Investment Co., Ltd. and Huawei Device (Hong Kong) Co., Ltd.
`
`B. Related Matters (37 C.F.R. §42.8(b)(2))
`Patent Owner has asserted the ’901 Patent in litigation against Huawei
`
`Device USA Inc. and Huawei Device Co., Ltd. in Maxell, Ltd. v. Huawei Device
`
`USA Inc., et al., Case No. 5:16-cv-00178-RWS (E.D. Tex.) (the “Litigation”).
`
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`C. Lead and Backup Counsel (37 C.F.R. §42.8(b)(3))
`Petitioner designates David Garr (Reg. No. 74,932) as lead counsel and
`
`Gregory Discher (Reg. No. 42,488) as back-up counsel, both of Covington &
`
`Burling LLP, One CityCenter, 850 Tenth Street, NW, Washington, DC 20001
`
`(postal and hand delivery); telephone: 202-662-6000; facsimile: 202-662-6291;
`
`and Anupam Sharma (Reg. No. 55,609) as back-up counsel, of Covington &
`
`Burling LLP, 333 Twin Dolphin Drive, Suite 700 Redwood City, CA 94065-1418
`
`(postal and hand delivery); telephone: 650-632-4700; facsimile: 650-632-4800.
`
`Service Information (37 C.F.R. §42.8(b)(4))
`D.
`Service information for lead and back-up counsel is provided in the
`
`designation of lead and back-up counsel above. A power of attorney is submitted
`
`with this Petition. Counsel for Petitioner consents to service of all documents by
`
`email at Huawei-HM-IPR@cov.com.
`
`III. FEES (37 C.F.R. §42.103)
`The undersigned authorizes the Office to charge $23,000 ($9,000 request
`
`fee, $14,000 post-institution fees) to Deposit Account No. 50-0740 for the fees set
`
`forth in 37 C.F.R. §42.15(a) for this Petition for IPR. The undersigned further
`
`authorizes payment for any additional fees that might be due in connection with
`
`this Petition to be charged to the above-referenced Deposit Account.
`
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`IV. REQUIREMENTS FOR IPR (37 C.F.R. §42.104)
`A. Grounds for Standing (37 C.F.R. §42.104(a))
`Petitioner certifies that the ’901 Patent is available for IPR and that
`
`Petitioner is not barred or estopped from requesting an IPR challenging the ’901
`
`Patent on the grounds identified in the present petition.
`
`B. Citation of Prior Art
`Exhibit
`Reference
`
`Publication
`
`Availability
`
`or Filing Date
`
`as Prior Art3
`
`Exs. 1003-
`
`Kitazawa (Japanese Patent
`
`November 28,
`
`§102(a) and
`
`04
`
`Application Publication No. 2003-
`
`2003
`
`(b)
`
`337580)
`
`(publication)
`
`Ex. 1005
`
`Iwabe (U.S. Patent No. 5,068,718) March 20,
`
`§102(a), (b)
`
`1990 (filing);
`
`and (e)
`
`November 26,
`
`1991
`
`(publication)
`
`
`3 All references to §§102 and 103 of the Patent Statute refer to the pre-AIA
`
`versions of those statutory provisions.
`
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`Exs. 1006-
`
`Yagi (Japanese Patent Application
`
`October 28,
`
`§102(a) and
`
`07
`
`Publication No. 6-303551)
`
`1994
`
`(b)
`
`(publication)
`
`Ex. 1008
`
`Shiota (U.S. Patent Application
`
`January 1,
`
`§102(a) and
`
`Publication No. 2004/0001165)
`
`2004
`
`(b)
`
`(publication)
`
`
`
`C. Claims and Statutory Grounds (37 C.F.R. §§42.104(b)(1) & (b)(2))
`The relief requested by Petitioner is that claims 1 and 2 of the ’901 Patent be
`
`found unpatentable and cancelled on the grounds below.
`
`Ground Claims
`
`Basis
`
`I
`
`II
`
`III
`
`
`
`1 and 2
`
`Under 35 U.S.C. §103 as unpatentable over the
`
`1
`
`2
`
`combination of Kitazawa and Iwabe
`
`Under 35 U.S.C. §103 as unpatentable over the
`
`combination of Yagi and Shiota
`
`Under 35 U.S.C. §103 as unpatentable over the
`
`combination of Yagi, Shiota, and Iwabe
`
`Person of Ordinary Skill in the Art
`D.
`For the ’901 Patent, a person of ordinary skill in the art (“POSITA”) would
`
`be someone with a working knowledge of image processing systems. The person
`
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`

`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`would have gained this knowledge through an undergraduate Bachelor of Science
`
`degree in Electrical/Computer Engineering, Computer Science, or an equivalent
`
`degree, and at least two years of experience working in the field of image
`
`processing. Ex. 1015 ¶16. In addition, the applied prior art reflects the appropriate
`
`level of skill at the time of the claimed invention. See Okajima v. Bourdeau, 261
`
`F.3d 1350, 1355 (Fed. Cir. 2001).
`
`E. Unpatentability of the Construed Claims (37 C.F.R. §42.104(b)(4))
`An explanation of how claims 1 and 2 of the ’901 Patent are unpatentable
`
`under the statutory grounds identified above is provided in Section VI, below.
`
`Supporting Evidence (37 C.F.R. §42.104(b)(5))
`F.
`The exhibit numbers of the supporting evidence relied upon to support the
`
`challenge and the relevance of the evidence to the challenge raised, including
`
`identifying specific portions of the evidence that support the challenge, are
`
`provided below in the form of explanatory text. An Exhibit List with the exhibit
`
`numbers and a brief description of each exhibit is set forth above.
`
`V.
`
`SUMMARY OF THE ’901 PATENT
`A. Overview of the Technology
`By the mid-2000’s, video signal processing apparatus that corrected video
`
`signals based on (1) the characteristics of the video signals, (2) the level of
`
`environmental illumination, and (3) the change in the video signals, was well-
`
`known.
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`The ’901 Patent admits that a video signal processing apparatus that
`
`“corrects the luminance signal” based on “a characteristic point of the luminance
`
`signal for each frame” is prior art. Ex. 1001, 1:20-25. Furthermore, the types of
`
`luminance correction that the ’901 Patent describes (as discussed in detail in
`
`Section V.B.3, below) were well-known. Ex. 1015 ¶26.
`
`Similarly, a video signal processing apparatus that takes into account the
`
`level of environmental illumination, was well-known at least by early 1990’s. Ex.
`
`1006; Ex. 1015 ¶27.
`
`Likewise, performing calculations for video signal correction when any
`
`change occurs in the video signal, was well-known by the early 2000’s. Ex. 1003;
`
`Ex. 1015 ¶28.
`
`B. Overview of the ’901 Patent
`The ’901 Patent (Ex. 1001) is entitled, “Image Processing Apparatus and
`
`Mobile Terminal Apparatus.” It issued on March 2, 2010 from U.S. Application
`
`No. 11/195,870, filed August 3, 2005, and claims foreign priority to Japanese
`
`Application 2005-080846, filed on March 22, 2005. Documents published before
`
`March 22, 2005 are prior art under 35 U.S.C. §102(a). Documents published
`
`before August 3, 2004 are prior art under 35 U.S.C. §102(b). Further, U.S. patents
`
`that issued from, or publications of, an application filed in the United States before
`
`March 22, 2005 are prior art under 35 U.S.C. §102(e).
`
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`Video Signal Correction
`1.
`The ’901 Patent is directed to an apparatus that corrects video signals.
`
`Video signals are composed of multiple still pictures, referred to as video frames.
`
`Ex. 1015 ¶30. There are typically only minor differences in what is occurring from
`
`frame to frame. Id. When there is a scene change, however, the frames of that
`
`new scene might change significantly from the preceding frames. Id.
`
`Each video frame consists of a grid of multiple pixels. Ex. 1015 ¶31. Each
`
`pixel represents a tiny portion of the video frame. Id. Correcting video signals
`
`involves adjusting three components of each pixel: luminance (brightness), hue
`
`(color), and saturation. Id.
`
`The luminance value specifies the level of brightness. Ex. 1015 ¶32.
`
`High Luminance
`
`Low Luminance
`
`
`
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
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`Hue is a technical name for color, such as red, blue, yellow, or green. Ex.
`
`1015 ¶33.
`
`Red Rose
`
`Cyan Rose
`
`
`
`
`
`
`
`And saturation refers to the purity of the color. Ex. 1015 ¶34. For example,
`
`pink is a less saturated red. Id.
`
`More Saturated Rose
`
`Less Saturated Rose
`
`
`
`
`
` Image Processing Apparatus
`2.
`Figure 19 of the ’901 Patent depicts a structural diagram of a mobile phone
`
`with a display.
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
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`
`
`TV antenna 12 converts a TV broadcasting radio wave to electrical signals
`
`and outputs it to TV tuner 13. Ex. 1001, 3:39-41 (referring to Figure 1).4 TV tuner
`
`13 processes the electrical signals and outputs them to CPU 7. Id., 3:41-43. CPU
`
`7 separates the video and audio signals, and sends the video signals to image
`
`improving circuit 15. Id., 3:48-52. Image improving circuit 15 corrects the video
`
`signals. Id., 4:13-15. In addition to the video signals, image improving circuit 15
`
`
`4 Figure 19 is the same as Figure 1, except that Figure 19 adds illumination sensor
`
`21. The ’901 Patent uses the same reference numerals in Figure 19 to “identify the
`
`same portion” in Figure 1. Ex. 1001, 11:46-49. Figure 19 is used here because
`
`“illumination sensor” is required by the claims.
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
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`receives a control signal from CPU 7 based on input from illumination sensor 21,
`
`id., 12:20-29,5 which detects the intensity of illumination, id., 11:64-12:3. After
`
`the correction of the video signals, image improving circuit 15 sends the improved
`
`video signals to display 16. Id., 4:13-15.
`
`Figure 22 shows image improving circuit 15 in more detail.
`
`Image improving circuit 15 receives the video signals from video interface 14. Ex.
`
`
`
`
`5 The reference to “illumination sensor 7” at 12:25-26 appears to be a
`
`typographical error. Figure 19 discloses illumination sensor 21 and CPU 7.
`
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
`
`1001, 4:30-35 (referring to Figure 2).6 RGB-YUV conversion 151 converts the
`
`video signals of the RGB (Red-Green-Blue) form to luminance signal (Y) and
`
`color difference signals R-Y and B-Y. Id. Color difference-HS conversion 153
`
`further converts color difference signals R-Y and B-Y to hue (H) and saturation
`
`(S). Id., 4:45-48. This conversion to luminance (Y), hue (H), and saturation (S)
`
`makes it easier to adjust each of those values. Ex. 1015 ¶40.
`
`Characteristic detection portion 154 “calculates characteristic point data.”
`
`Ex. 1001, 4:48-54. Based on the characteristic point data, CPU 7 calculates
`
`correction data and stores it in interface (I/F) portion 155. Id., 4:54-61. Correction
`
`portion 152 corrects the video signals in accordance with the correction data in I/F
`
`portion 155, and outputs them as corrected luminance (Y’), hue (H’), and
`
`saturation (S’). Id., 4:61-65. HS-color difference conversion 156 and YUV-RGB
`
`conversion 157 converts the YHS signals back to the RGB form. Id., 4:65-5:3.
`
`
`6 Figure 22 is the same as Figure 2, except that Figure 22 adds RGB gain
`
`adjustment 1510 that corrects luminance based on the level of environmental
`
`illumination. Ex. 1001, 12:20-24. The ’901 Patent uses the same reference
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`numerals in Figure 22 to “identify the same portion” in Figure 2. Id. Figure 22 is
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`used here because correcting luminance based on the level of environmental
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`illumination is required by the claims.
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
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`Finally, RGB gain adjustment 1510 further corrects the luminance when the level
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`of environmental illumination is above a certain value. Id., 12:20-29.
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`Figure 6 shows an example of a luminance histogram.
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`
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`For each range of luminance (e.g., 0-15 and 16-31), the luminance histogram stores
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`a count of how many pixels in a given video frame have input luminance values in
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`that range. Ex. 1001, 6:49-51. For example, in the example shown in Figure 6
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`above, the current video frame has 10,000 pixels that have input luminance values
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`between 0 and 15 (Yhst0). Id., Fig. 6.
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`Hue characteristic detection and saturation characteristic detection work
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`similarly. Ex. 1001, Figs. 7-10, 6:56-7:50.
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`Figure 11 shows I/F portion 155 in more detail:
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
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`I/F portion 155 contains scene change detection 1552 and I/F register 1551. Scene
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`change detection 1552 stores the characteristic point data from characteristic
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`detection portion 154, id., 7:54-57, and generates INT 141 for CPU 7 when there is
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`a scene change, id., 7:60-62. INT 141 is an interrupt that informs the CPU of a
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`scene change. Ex. 1015 ¶49. CPU 7 reads the characteristic point data from I/F
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`register 1551, and calculates and stores the correction data in I/F register 1551. Ex.
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`1001, 7:62-64. Correction portion 154 uses the correction data in I/F register 1551
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`to correct the video signals. Id., 8:63-65.
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`In one embodiment, the scene change is detected when any difference exists
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
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`in the minimum value, the maximum value, the mean value, and the histogram of
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`luminance, hue, and saturation. Ex 1001, 8:10-21. In another embodiment, the
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`’901 Patent discloses that “it is most effective” to detect scene change based on the
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`mean value of luminance only, rather than based on all of the other values. Id.,
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`8:37-42. The ’901 Patent further discloses that the scene change can be deemed to
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`have occurred when the difference in value is greater than a certain threshold. Id.,
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`8:49-52.
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`The Background section of the ’901 Patent acknowledges a multimedia
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`computer system that corrects video signals is in the prior art, but points out two
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`purported problems with the prior art approaches. Id., 1:20-38. The first problem
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`is power consumption associated with performing calculations for the video signal
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`correction for every video frame. Id., 1:26-35.
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`The ’901 Patent purports to solve the power consumption issue by omitting
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`the computations and the associated data transfers for the video signal correction
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`when there is no change in the video signals, that is, no scene change: “as the scene
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`change detection portion 1552 operates, read of the characteristic data and
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`generation of the correction data by CPU 7 and the write processing to the I/F
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`register 1551 can be omitted when the scene is the same as the pattern of the
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`preceding frame.” Id., 8:28-32. “Therefore, the processing load of CPU 7 can be
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`reduced and a consumed current for the data transfer can be reduced, too.” Id.,
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
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`8:32-34.
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`The second problem arises when the level of environmental illumination is
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`so high (perhaps because the viewer moved the display outside, into bright
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`sunshine) that the viewer finds it hard to view the displayed video. Id., 1:35-38.
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`The ’901 Patent purports to solve the environmental illumination issue with
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`RGB gain adjustment 1510. RGB gain adjustment 1510 further corrects the
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`luminance when the level of environmental illumination is above a certain value.
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`Id., 12:20-29. “When the intensity of illumination exceeds the predetermined
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`value, CPU 7 outputs a control signal instructing correction of the output tone to
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`the RGB gain adjustment portion 1510.” Id., 12:26-29. “The RGB gain
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`adjustment portion 1510 reads out the correction data from the memory 9 through
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`the I/F portion in accordance with control from CPU 7 and adjusts the gain of the
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`video signal.” Id., 12:29-32. So, if the environmental illumination increases, for
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`example because the user moves the display outside, into bright sunshine, the
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`video signals are corrected so that the user can still view the display. Id., 12:36-49;
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`Ex. 1015 ¶52 .
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
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`Correction of Luminance7
`3.
`The ’901 Patent describes two main ways of correcting luminance of an
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`image. The first way is increasing the contrast based on the minimum and
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`maximum luminance values of the input video signals. Ex. 1001, Figs. 14A-B,
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`15A-B, 16A-B, 9:41-10:36; Ex. 1015 ¶53. Figure 16A of the ’901 Patent shows an
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`example luminance histogram of a given video frame.
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`
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`In Figure 16A shown above, the input tone on the x-axis represents the input
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`luminance values, ranging from 0 to 255. Ex. 1015 ¶54. The frequency on the y-
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`7 The ’901 Patent also describes correcting hue by emphasizing certain colors, Ex.
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`1001, 10:37-41, and correcting saturation if the maximum saturation of an image
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`falls below a certain value, id., 11:2-4. But, the ’901 Patent explains that it is the
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`level of luminance that “most greatly affects the visual feeling of the users.” Id.,
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`8:37-42.
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
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`axis represents the number of pixels in a given frame for the corresponding range
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`of input luminance. Id. In this example, the minimum luminance value is 31. Ex.
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`1001, 10:20-22. Similarly, the maximum luminance value is 223. Ex. 1001,
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`10:20-22.
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`Figure 16B shows how to correct the luminance of the video frame
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`represented by the luminance histogram in Figure 16A.
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`
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`In Figure 16B shown above, the input tone on the x-axis represents the input
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`luminance value of a pixel. Ex. 1015 ¶56. The output tone on the y-axis
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`represents the corrected output luminance value of the same pixel. Id. Dotted line
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`1601 represents what would have happened if no corrections were made. Ex.
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`1001, 10:26-28. In contrast, solid line 1602 shows how each input luminance
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`value is corrected. Id., 10:28-29. For example, a pixel with an input luminance
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
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`value of 31 is corrected so that its output luminance value will be decreased from
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`31 to 0. Ex. 1015 ¶56. Similarly, a pixel with an input luminance value of 223 is
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`corrected so that its output luminance value will be increased from 223 to 255. Id.
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`In the example shown in Figures 16A and 16B, the ’901 Patent states that
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`the input luminance ranges 0-31 and 223-255 can be safely ignored (based on the
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`minimum input luminance value 31 and the maximum input luminance value 223),
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`and the middle range 31-223 is mapped to the entire output luminance range of 0-
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`255. Ex. 1001, 10:29-33. In the annotated Figure 16B, below, the dotted arrow
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`shows the limited range of the output luminance before the correction, while the
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`solid arrow shows the full range of the output luminance after the correction. Ex.
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`1015 ¶57.
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`Because darker pixels are made darker and brighter pixels are made brighter
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`over the full range of the output luminance, the displayed image has a better
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`Petition For Inter Partes Review Of U.S. Patent No. 7,671,901
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`contrast and can be viewed more easily. Ex. 1015 ¶58. The ’901 Patent states that
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`“[w]hen correction is made in this way, the contrast of the intermediate tone can be
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`increased and an image that can be more easily watched can be displayed.” Ex.
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`1001, 10:33-36.
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`The second way of correcting luminance is making the darker pixels
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`brighter, when the environmental illumination is above a certain level. Id., 12:36-
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`49. Figure 23B shows an example of the second way of correcting luminance.
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`
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`As before, the input tone on the x-axis represents the luminance value of a pixel of
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`the input video frame. Ex. 1015 ¶60. And the output tone on the y-axis represents
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`the corrected luminance value of the same pixel. Id. As before, the d