10342711 (B.P.A.I. Aug. 24, 2007)

Ex Parte Joly et al

Board of Patent Appeals and InterferencesAug 24, 2007

10342711 (B.P.A.I. Aug. 24, 2007)

This opinion is not binding precedent of the Board. UNITED STATES PATENT AND TRADEMARK OFFICE ____________ BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES ____________ Ex parte AGFA HEALTHCARE ____________ Appeal 2007-3363 Application 10/342,711 Technology Center 1700 ____________ Decided: August 24, 2007 ____________ Before FRED E. McKELVEY, Senior Administrative Patent Judge, and RICHARD TORCZON and JAMES T. MOORE, Administrative Patent Judges. TORCZON, Administrative Patent Judge. DECISION ON APPEAL The subject matter of the claims on appeal relates to binderless storage phosphor screens. All pending claims have been rejected. The appellant (Agfa) seeks review of the rejection. We affirm. THE CLAIMS Claims 1-4 and 21-24 are pending. Agfa has not provided separate arguments for the claims so we treat the claims as standing or falling together. 37 C.F.R. Â§ 41.37(c)(1)(vii). The two independent claims are Appeal 2007-3363 Application 10/342,711 essentially the same except in the percentage of light absorbed and reflected. We select claim 1 as representative of the claims on appeal. Claim 1 is reproduced as it appears in the claim appendix to the Substitute Appeal Brief (Br.) except that it has been indented as required under 37 C.F.R. Â§ 41.75(i): 1. A binderless stimulable phosphor screen comprising a vapor deposited phosphor layer on a support incorporating into the bulk of said support a white pigment and a pigment absorbing light of a wavelength above 600 nm absorbing at least 30 % of the stimulating light and reflecting at least 60 % of the stimulated light wherein said vapor deposited phosphor is a needle- shaped phosphor, being a CsX:Eu stimulable phosphor, wherein x [sic, X] represents a halide selected from the group consisting of Br and Cl. We are obligated to construe an application claim as broadly as is reasonable in view of the specification. The screen is defined using the transitional term "comprising", which opens the screen to the inclusion of elements not listed in the claim. The phrase "vapor deposited phosphor" is expressly defined to mean any of thermal-vapor deposition, chemical-vapor deposition, electron-beam deposition, radio-frequency deposition, and pulsed-laser deposition. (Specification (Spec.) 4:7-11.) Agfa prefers supports that are ceramic, glass, or polymer film (Spec. 4:14-20), but the claim is not limited to these. Suitable white pigments include titanium dioxide (TiO2) and barium sulfate (BaSO4) (Spec. 4:27-30), but the claim is not limited to these. The specification gives organic and inorganic blue pigments as examples of pigments absorbing 2 Appeal 2007-3363 Application 10/342,711 light of a wavelength above 600 nm (Spec. 4:24-5:19), but again the claim is not so limited. It is not clear whether it is the support or the colored pigment in the support that absorbs 30% of the stimulating light and reflects 60% of the stimulated light. Since no argument is directed to these percentages, this ambiguity does not affect our analysis. We construe "stimulated light" to mean light emitted by the stimulable phosphor. "CsX:Eu" is a cesium halide phosphor doped with europium. (Spec. 7:21-36.) Claim 1 requires the cesium halide to be cesium bromide or cesium chloride. Hence, the phosphor could be designated CsBr:Eu or CsCl:Eu. THE REJECTION The examiner has rejected all of the pending claims under 35 U.S.C. Â§ 103 for claiming subject matter that would have been obvious to a person having ordinary skill in the art at the time of filing. The examiner relies on a published patent application and two patents as evidence in support of the rejection. (Examiner's Answer (Ans.) 4.) The published application is: Erich Hell, Manfred Fuchs, Detlef Mattern, Bernhard Schmitt & Paul Leblans, Binderless storage phosphor screen with needle shaped crystals, US 2003/0091729 A1 (pub'd 15 May 2003) (Hell). Paul Leblans is also named as an inventor on the application currently before us. The patents are: Kenji Takahashi et al., Radiation image storage panel, U.S. Patent 4,394,581 (issued 19 July 1983) (Takahashi); and 3 Appeal 2007-3363 Application 10/342,711 James J. Powell et al., X-Ray imaging screen with process for its preparation, U.S. Patent 5,107,125 (issued 21 April 1992) (Powell). In analyzing obviousness, the scope and content of the prior art must be determined, the differences between the prior art and the claims ascertained, and the ordinary level of skill in the art resolved. Objective evidence of the circumstances surrounding the origin of the claimed subject matter (so-called secondary considerations) may also be relevant. Such secondary considerations guard against the employment of impermissible hindsight. Graham v. John Deere Co., 383 U.S. 1, 17, 36 (1966), cited with approval in KSR Int'l v. Teleflex Inc., 127 S. Ct. 1727, 82 USPQ2d 1385 (2007). Afga's Appeal Brief does not rely on any objective evidence of secondary considerations. The scope and content of the prior art Hell teaches binderless storage phosphor screens with needle-shaped phosphors. (Hell Â¶0002.) The use of alkali metal halide phosphors in storage screens was well known. Hell explains that their high crystal symmetry makes binderless screens possible. (Hell Â¶0005.) Hell's "highly preferred" phosphors for binderless phosphor screens are CsX:Eu stimulable phosphors, where X is bromide or chloride. (Hell Â¶0026.) The most preferred one is CsBr:Eu. (Hell Â¶0031.) Hell teaches making a binderless phosphor layer on a support using physical-vapor deposition, thermal-vapor deposition, chemical-vapor deposition, electron-beam deposition, radio-frequency deposition, and pulsed-laser deposition. (Hell Â¶0016.) In the specific example disclosed, thermal-vapor deposition was used to make a CsBr:Eu phosphor layer on a 4 Appeal 2007-3363 Application 10/342,711 glass support. (Hell Â¶0047.) Other support materials are taught including pigmented paper containing titanium dioxide, pigment-coated glass, and pigment-containing thermostable plastic films. Titanium dioxide and barium sulfate are suggested as appropriate light-reflecting (white) pigments, with specific uses (high resolution and high sensitivity, respectively) suggested for each. (Hell Â¶Â¶043-045.) Takahashi teaches radiation image storage panels using stimulable phosphors that store radiation energy and emit light when stimulated. (Takahashi 1:4-11.) Takahashi teaches a variety of suitable phosphors and specifically notes that any phosphor may be used as long as it "emits light when exposed to stimulating rays after exposure to radiation." (Takahashi 6:54-7:30.) A binder is used to deposit the phosphor on a support, but binders adversely affect panel sensitivity and sharpness, and are thus preferably minimized. (Takahashi 7:52-8:24.) Suitable supports include glass, paper, and polymer films. Paper containing pigment including titanium dioxide is mentioned. (Takahashi 8:25-43.) The support may be colored, but if so the colorant (pigment) should absorb stimulating rays. Glass or plastic supports may have pigment on the surface or the pigment may be dispersed throughout the support. (Takahashi 8:57-9:8.) Takahashi notes that improving panel sharpness by using a colorant is known, but warns that colorants can also decrease panel sensitivity. In addition to absorbing the stimulating radiation, the pigment may also absorb the emitted radiation. Thus more pigment can result in better resolution, but less intensity. Takahashi suggests two solutions: (1) using a pigment that absorbs at different wavelengths than the wavelengths the phosphor emits or 5 Appeal 2007-3363 Application 10/342,711 (2) by increasing the intensity of the stimulating radiation. (Takahashi 4: 1- 44.) Takahashi advises that when the panel is colored, the wavelengths that the phosphors emit should be different than the wavelength of the stimulating radiation, and uses the example of stimulating rays with wavelengths from 500-800 nm. For this wavelength range, the pigments should be blue to green. (Takahashi 6:1-25.) Several specific organic and inorganic pigments are listed, all twenty of which are also listed in Agfa's specification as examples of "blue" pigments. (Compare Takahashi 6:25-53 with Spec. 4:30-5:19.) Powell teaches an X-ray imaging screen. (Powell 1:6-7.) Powell's relevant teachings bolster the teachings in Takahashi. Like Takahashi, Powell recommends using stimulating radiation outside the visible range (ultraviolet and infrared) with complementary pigments to avoid absorbing the visible light emitted from the phosphors. (Powell 1:51-58 and 10:14-23.) Agfa argues that Powell is not analogous art because it only discusses storage phosphors in one place, albeit to say that they face problems similar to those Powell faces. (Br. 10, citing Powell 1:64-69.) In fact, the preceding paragraph in Powell discusses storage phosphor screens and even cites a different patent to Kenji Takahashi. (Powell 1:44-63.) Prior art is analogous if it lies in the same field as the claimed subject matter or if it addresses a similar problem to the one facing the inventor. In re Bigio, 381 F.3d 1320, 1325, 72 USPQ2d 1209, 1212 (Fed. Cir. 2004). The principal teaching of Powell for the purposes of this appeal is the use of a selective pigment to absorb stimulating radiation but not absorb light emitted by the phosphor. This teaching is the same approach taught in 6 Appeal 2007-3363 Application 10/342,711 Takahashi and claimed in Agfa's claim 1. We find Powell to be analogous art. The differences between the prior art and claim 1 Hell teaches light-absorbing pigments in the support, but the sole example (carbon black) is a light-absorbing pigment that appears to be used as an alternative to light-reflecting pigments. (Hell Â¶045.) Hell does not teach a pigment for absorbing wavelengths greater than 600 nm to be used with a light-reflecting pigment. Agfa argues that the use of light-absorbing pigments was known but comes at a cost, using the example of titanium dioxide increasing sensitivity but decreasing resolution. (Br. 6.) Hell appreciated the costs associated with the white pigments (although Hell actually teaches that titanium dioxide is used for high resolution). (Hell Â¶045.) Takahashi does not teach the use of alkali metal halide phosphors, but does teach the use of any phosphor that emits light when exposed to stimulating rays after exposure to radiation. Takahashi also uses a binder although it counsels that binder use be minimized. Powell also uses binders but not alkali metal halide phosphors. The ordinary level of skill in the art We look to the evidence of recordâ€”the applicant's disclosure, the cited references, and any declaration testimonyâ€”in resolving the ordinary level of skill in the art. Ex parte Jud, 2006 WL 4080053 at *2 (BPAI) (rehearing with expanded panel). Agfa provided no testimony on appeal. We focus on what a person having ordinary skill in the art knew and could do. 7 Appeal 2007-3363 Application 10/342,711 The specification is consistent with Hell's teaching that those of skill knew that binderless screens are preferred and that needle-like alkali halide phosphors make good binderless screens possible. (Spec. 2:9-35; Hell passim.) From Hell, those in the art would know how to make such screens using CsX:Eu phosphors on white pigmented supports. From Takahashi, they would know that colored pigments improve screen resolution. From Takahashi and Powell, they would know how to pick selective pigments that absorb stimulating radiation in wavelengths different than those the phosphors emit. Takahashi permits some overlap, while Powell completely avoids stimulating radiation in the range (visible) important to screen users, using ultraviolet and infrared stimulating radiation instead. We take official notice that a person having ordinary skill in the art would know that 600 nm light is orange-red and would be absorbed by blue- green pigments, while infrared light has wavelengths greater than 600 nm. Such a person would know that Powell's use of infrared stimulating radiation and complementary dyes would not effect the visible-light emission of Powell's phosphors. Agfa argues that Takahashi and Hell teach that resolution and sensitivity are mutually exclusive because Takahashi's pigments would undermine Hell's quest for greater sensitivity, while Takahashi's suggestion to increase stimulating radiation intensity is impractical. (Br. 7.) There are two problems with this argument. First, Takahashi does suggest increasing stimulating radiation intensity as an option, but focuses instead on choosing a selective pigment that does not absorb wavelengths the phosphor emits. Second, the problems Agfa cites for increasing stimulating radiation intensity are not supported with citations to the record and will not be 8 Appeal 2007-3363 Application 10/342,711 accepted on the basis of attorney argument. Without the context provided by evidence, we cannot assess how one skilled in the art would view these problems. Although Takahashi pursues the selective pigment approach instead, it suggests that in some applications increasing stimulating radiation intensity may be necessary or appropriate. Agfa argues that those in the art would expect the white pigment and the blue pigment to cancel each other because white would increase sensitivity at the cost of resolution, while blue would do the opposite. (Spec. 8.) Hell teaches (Â¶045) that one white pigment, titanium dioxide, is used in high resolution screens so there is no inherent conflict between white pigment and high resolution. Agfa argues that those in the art know that the phosphors of Takahashi and Hell work completely differently, so their teachings cannot be combined, but Agfa provides only attorney argument that this difference would be significant to those in the art. (Br. 9.) In any case, a person having ordinary skill in the art reading Takahashi would understand that its teaching applies to any phosphor that emits light in response to stimulating radiation after having been exposed to radiation. (Takahashi 7:25-30.) Takahashi relies on the art to teach the phosphor because Takahashi is focused on the use of a selective pigment to avoid absorbing light emitted by the phosphor. (Takahashi claim 1.) Those in the art would appreciate that any suitable phosphor could be used in Takahashi's screens. Hell purports to have produced superior phosphors for such screens. Since Takahashi and Hell solve different problems for the same screens, those in the art would appreciate the advantages of using both teachings. 9 Appeal 2007-3363 Application 10/342,711 CONCLUSION The subject matter of claim 1 would have been obvious to a person having ordinary skill in the art. Since claims 2-4 and 21-24 stand or fall with claim 1, they fall with claim 1. The rejection of claims 1-4 and 21-24 isâ€” AFFIRMED yrt Joseph T. Guy NEXSEN PRUET JACOBS & POLLARD LLP 201 W MCBEE AVE GREENVILLE SC 29603 10