Ex Parte Brown et al

Patent Trial and Appeal BoardMar 23, 2015

12303567 (P.T.A.B. Mar. 23, 2015)

UNITED STATES PATENT AND TRADEMARK OFFICE ___________________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ___________________ Ex parte CHRISTOPHER JAMES BROWN and BEN JAMES HADWEN ___________________ Appeal 2013-001448 Application 12/303,567 Technology Center 2600 ____________________ Before SALLY C. MEDLEY, JONI Y. CHANG, and MICHAEL R. ZECHER, Administrative Patent Judges. ZECHER, Administrative Patent Judge. DECISION ON APPEAL I. STATEMENT OF THE CASE Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s rejection of claims 1–27. App. Br. 1; Ans. 3. We have jurisdiction under 35 U.S.C. § 6(b). We reverse. The Invention Appellants purportedly invented an image sensor that includes an array of sensor elements. Abstract. Each sensor element includes an amplifying transistor whose gate is connected to an integrating node, which, Appeal 2013-001448 Application 12/303,567 2 in turn, is connected to one plane of an integrating capacitor and to one electrode of a photodiode. Id. The other electrode of the photodiode is connected to a resetting line. Id. According to Appellants, each sensor element is capable of performing a repeating sensing cycle that includes a resetting phase, an integrating phase, and a reading phase. Abstract. During the resetting phase, the resetting line receives a voltage that forward-biases the photodiode so as to charge the integrating node to a predetermined voltage. Id. Once the resetting line is returned to a voltage for reverse- biasing the photodiode, the integrating and reading phases may be performed. Id. Illustrative Claim Claim 1 is the only independent claim. Independent claim 1 is directed to an image sensor that includes at least one sensor element. Claims 2–27 directly or indirectly depend from independent claim 1. Independent claim 1 is illustrative of the disclosed invention and is reproduced below (emphases added): 1. An image sensor comprising at least one sensor element, the or each of which comprises a semiconductor amplifying element, an integrating capacitor, and a photodiode having a first electrode, which is connected to a first control electrode of the amplifying element and a first terminal of the capacitor, and a second electrode connected to a first control input, which is arranged to receive, during a sensing phase, a first voltage for reverse-biasing the photodiode and to receive, during a resetting phase, a second voltage for forward-biasing the photodiode so as to charge the capacitor to a predetermined voltage. Appeal 2013-001448 Application 12/303,567 3 Prior Art Relied Upon Young US 6,489,631 B2 Dec. 3, 2002 Shin US 7,329,848 B2 Feb. 12, 2008 (filed July 26, 2005) Rejections on Appeal Claims 1–25 and 27 stand rejected under 35 U.S.C. § 102(b) as being anticipated by Young. Ans. 4–5. Claim 26 stands rejected under 35 U.S.C. § 103(a) as being unpatentable over the combination of Young and Shin. Id. at 5–6. Examiner’s Findings and Conclusions The Examiner finds that Figures 2 and 6 of Young, and their corresponding descriptions, disclose each of the limitations recited in dependent claims 22–25 and 27. Ans. 4–5 (citing Young, 5:42–53, 9:58– 10:30, Figs. 2, 6). The Examiner then finds that, because claims 1–21 have the same structure as claims 22–25 and 27, Figures 2 and 6 of Young, and their corresponding descriptions, also describe each of the limitations recited in claims 1–21. Id. at 5 (stating that “claims (1-21) have the same structure as claims (22-25 and 27), thus, claims (1-21) are met by the same anticipation as claims (22-25 and 27)”). In response to Appellants’ arguments against independent claim 1, the Examiner finds that thin film transistor (“TFT”) 40 in Figure 2 of Young possesses the inherent characteristics of a photodiode. Ans. 7–8. The Examiner also finds that Young’s Background and Summary section discloses a bias photosensitive device that is capable of charging a capacitor. Id. at 8 (citing Young, 2:54–64). Based on these cited disclosures, the Examiner finds that Young describes “a photodiode having . . . a second electrode connected to a first control input, which is arranged to receive . . . , Appeal 2013-001448 Application 12/303,567 4 during a resetting phase, a second voltage for forward-biasing the photodiode so as to charge the capacitor to a predetermined voltage,” as recited in independent claim 1. Id. Appellants’ Contentions Appellants contend that Figures 2 and 6 of Young, and their corresponding descriptions, do not disclose the “photodiode,” as recited in independent claim 1. App. Br. 7 (citing Young, 5:42–53, 9:58–10:13, Figs. 2, 6). Appellants assert that, even if Young’s TFT 40 constitutes the claimed “photodiode,” Young discloses that TFT 40 behaves as a leakage device, in the manner of a reverse-biased photodiode, which causes capacitor 36 to leak charge. Id. at 7, 9–10 (citing Young, 6:9–12). Based on this cited disclosure, Appellants argues that Young’s TFT 40 discharges capacitor 36, rather than charges capacitor 36. Id. In addition, Appellants contend that, contrary to the position taken by the Examiner in the Answer, Young’s Background and Summary section discloses a bias photosensitive device that serves as a “charge adjusting device.” Reply Br. 4–5 (citing Young, 2:54–64). Appellants assert that this disclosure in Young is consistent with its initial positon that Young’s TFT 40 is used as a “charge adjusting device” that discharges capacitor 36. Id. at 5. II. ISSUE Has the Examiner erred in determining that Young anticipates independent claim 1? In particular, the issue turns on whether: Appeal 2013-001448 Application 12/303,567 5 (a) the Examiner has met its initial burden of presenting a prima facie case of anticipation; and (b) Young describes “a photodiode having . . . a second electrode connected to a first control input, which is arranged to receive . . . , during a resetting phase, a second voltage for forward-biasing the photodiode so as to charge the capacitor to a predetermined voltage,” as recited in independent claim 1 (“the ‘photodiode’ limitation”). III. ANALYSIS 35 U.S.C. § 102(b) Rejection—Young Claim 1 Based on the record before us, we discern error in the Examiner’s anticipation rejection of independent claim 1, which recites, inter alia, the “photodiode” limitation reproduced above. At the outset, we note that the Examiner bears the initial burden of presenting a prima facie case of anticipation. In re King, 801 F.2d 1324, 1327 (Fed. Cir. 1986); In re Wilder, 429 F.2d 447, 450 (CCPA 1970). In this case, the Examiner has not met its burden. The Examiner relies upon Figures 2 and 6 of Young, and their corresponding descriptions, to disclose all the limitations recited in independent claim 1. See Ans. 5 (citing Young, 5:42–53, 9:58–10:30, Figs. 2, 6). The Examiner, however, does not explain adequately how the elements illustrated in Figures 2 and 6 of Young describe the limitations recited in independent claim 1. For instance, it is not apparent to us what elements in Figures 2 and 6 of Young the Examiner relies upon to describe the “photodiode” limitation recited in independent claim 1. We will not go Appeal 2013-001448 Application 12/303,567 6 through the entirety of Young’s description of Figures 2 and 6 to determine which elements the Examiner believes correspond to each limitation recited in independent claim 1—this is something that the Examiner should have done when presenting its initial case of anticipation. Nevertheless, we agree with Appellants that Young does not describe the “photodiode” limitation. See App. Br. 7, 9–10. Even if we assume that the Examiner relies upon Young’s TFT 40 to describe the “photodiode” limitation, Young discloses that TFT 40 behaves as a leakage device, in the manner of a reverse-biased photodiode, which causes capacitor 36 to leak charge. Young, 6:9–12. The resulting discharge of Young’s capacitor 36 is contrary to the requirements of the “photodiode” limitation—namely, “forward-biasing the photodiode so as to charge the capacitor to a predetermined voltage.” We also agree with Appellants that Young’s Background and Summary section, particularly the disclosure of a bias photosensitive device serving as a “charge adjusting device” (Young, 2:54– 64), does not undermine Young’s disclosure that TFT 40 behaves as a leakage device, in the manner of a reverse-biased photodiode, which causes capacitor 36 to leak charge. See Reply Br. 4–5. We, therefore, are not persuaded that the Examiner has presented sufficient evidence to support a finding that Young describes the “photodiode” limitation. We need not reach the merits of Appellants’ other arguments because the Examiner has not met its burden of presenting a prima facie case of anticipation, and the Examiner does not account properly for the “photodiode” limitation. It follows that the Examiner has erred in determining that Young anticipates independent claim 1. Appeal 2013-001448 Application 12/303,567 7 Claims 2–25 and 27 The Examiner erred in rejecting dependent claims 2–25 and 27 for the same reasons set forth above in our discussion of independent claim 1 because each of these dependent claims incorporates the same disputed limitation as its underlying base claim. Remaining 35 U.S.C. § 103(a) Rejection Claim 26 As applied by the Examiner, Shin does not remedy the deficiencies in Young discussed above in the context of the Examiner’s anticipation rejection of independent claim 1. Given that dependent claim 26 incorporates the same disputed limitation as its underlying base claim, the Examiner has erred in determining that the combination of Young and Shin renders dependent claim 26 unpatentable. IV. CONCLUSIONS OF LAW The Examiner has erred in rejecting: (1) claims 1–25 and 27 as being anticipated under 35 U.S.C. § 102(b); and (2) claim 26 as being unpatentable under 35 U.S.C. § 103(a). V. DECISION We reverse the Examiner’s decision to reject claims 1–27. REVERSED