UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES

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1 UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE BOARD OF PATENT APPEALS AND INTERFERENCES Ex parte JOHANNES HENRICUS VAN BIJNEN and PETER HUMPHREY DE LA RAMBELJE Appeal Technology Center 2800 Decided: 2 July 15, 2009 Before KENNETH W. HAIRSTON, ROBERT E. NAPPI, and MARC S. HOFF, Administrative Patent Judges. HOFF, Administrative Patent Judge. DECISION ON APPEAL 1 The real party in interest is Koninklijke Philips Electronics, N.V. 2 The two-month time period for filing an appeal or commencing a civil action, as recited in 37 C.F.R , begins to run from the decided date shown on this page of the decision. The time period does not run from the Mail Date (paper delivery) or Notification Date (electronic delivery).

2 STATEMENT OF CASE Appellants appeal under 35 U.S.C. 134 from a Final Rejection of claims We have jurisdiction under 35 U.S.C. 6(b). We reverse. Appellants invention relates to an electrical bridge for generating a pulse width modulated (PWM) output voltage signal for a load. A control unit varies the pulse widths and/or phases of the first and second PWM switch-signals it produces in order to vary the pulse width of the PWM output voltage signal (Spec. 1). To generate a zero PWM output voltage signal, the respective pulse width and phase of the first and second PWM switch-signals are controlled to be substantially equal (Spec. 2). Claim 1 is exemplary: 1. A system for generating a PWM output voltage signal for a load, wherein the system comprises: a first half bridge and a second half bridge, wherein the first half bridge comprises a series connection of a first switch and a second switch and wherein the second half bridge comprises a series connection of a third switch and a fourth switch, wherein the first half bridge and the second half bridge are connected between a first rail and a second rail for supplying a DC voltage over the first and second half bridge, and wherein, in use, the load is connected between a first junction of the first switch and the second switch and a second junction of the third switch and the fourth switch, and a control unit configured for generating at least a first PWM switchsignal for switching the switches of the first half bridge and at least a second PWM switch-signal for switching the switches of the second half bridge, wherein the control unit is further configured for varying pulse widths and/or phases of the first and second PWM switch- signals relative to each other for varying a pulse width of the PWM output voltage signal, wherein, for generating a zero PWM output voltage signal, the control unit configured to generate the first PWM switch-signal and the second PWM switch-signal such that the respective pulse width and phase of the 2

3 first PWM switch-signal and the respective pulse width and phase of the second PWM switch-signal are, at least substantially, equal. appeal. No prior art is relied upon by the Examiner in rejecting the claims on Claims 1-15 stand rejected under 35 U.S.C. 112, first paragraph, as failing to comply with the enablement requirement. Throughout this decision, we make reference to the Appeal Brief ( App. Br., filed June 19, 2007), the Reply Brief ( Reply Br., filed March 3, 2008) and the Examiner s Answer ( Ans., mailed January 3, 2008) for their respective details. ISSUE The Examiner concludes that Appellants claimed invention is not enabled because Appellants have not provided a detailed description of the generation of the PWM switch-signals by control unit 20 (Ans. 5). Appellants argue that one having ordinary skill in the art would know how to make and use the invention based on the description at pages 6-7 of the Specification and the waveforms illustrated in Figure 2 (Reply Br. 3). The contentions of Appellants and the Examiner thus present us with the following issue: Have Appellants shown that the Examiner erred in concluding that the claimed invention is not enabled because Appellants Specification does not provide a detailed description of the manner in which control unit 20 generates PWM switch-signals 22.1 to 22.4? 3

4 FINDINGS OF FACT The following Findings of Fact (FF) are shown by a preponderance of the evidence. The Invention 1. Appellants Figure 2 includes a graphical representation of the desired PWM switch-signal waveforms. 2. Appellants Specification discloses that switch-signal 22.1 is generated by the control unit on the basis of the control signal 8 and the auxiliary ramp signal 26. The control signal 8 is inversed and subsequently crossed with the auxiliary signal 26 (see coordinate system 24.1) which results in first intersection points. These first intersection points define the switching time points of the first switch-signal 22.1 (Spec. 6:32 7:1). PWM switch-signal 22.2 is generated by the control unit 20 by crossing the control signal 8 with the auxiliary signal 26, which results in second intersection points [which] define the switching time points of the second switch-signal 22.2 (Spec. 7:9-11). PWM switch-signal 22.3 is disclosed as the inverse of switch-signal 22.1 (Spec. 7:7), and PWM switch-signal 22.4 is the inverse of switch-signal 22.2 (Spec. 7:16). Ansari 3. U.S. Patent No. 6,867,645 to Ansari teaches that the width and spacing of PWM output signal pulses are determined by one of various PWM schemes, which are shown in texts cited in the patent (col. 4, l. 54 col. 5, l. 1). 4. Depending on the PWM scheme selected, control signals can be generated and transmitted by a processor to the inverter bridge circuit to control the timing of the operation of the switches (col. 5, ll. 7-10). 4

5 PRINCIPLES OF LAW The test of enablement is whether one reasonably skilled in the art could make or use the invention from the disclosures in the patent coupled with information known in the art without undue experimentation. United States v. Telectronics, Inc., 857 F.2d 778, 785 (Fed. Cir. 1988). [A] patent disclosure need not enable information within the knowledge of an ordinarily skilled artisan. Thus, a patentee preferably omits from the disclosure any routine technology that is well known at the time of application. Chiron Corp. v. Genentech, Inc., 363 F.3d 1247, 1254 (Fed. Cir. 2004). ANALYSIS Claims 1, 8, and 11 are the independent claims in this application. Each independent claim recites a control unit that generates first and second pulse width modulation (PWM) switch-signals, varying at least one of the pulse widths and phases of the two PWM switch-signals such that the PWM output voltage signal equals zero when the pulse widths of the first and second PWM switch-signals are equal or substantially equal. The Examiner concludes that these limitations have not been enabled in the Specification (Ans. 3). In the Examiner s view, the description of Figure 2 (which shows a number of waveforms of the invention, including the PWM switch-signals) at pages 6-7 of the Specification do not enable how [control unit] 20 operates for varying pulse widths and/or phases of the first and second PWM switch-signals but rather only show some connections to and from the black box 20 which arbitrarily labeled as control unit and describe what results might be expected at its outputs (Ans. 4). 5

6 We are not persuaded by the Examiner s position. Appellants Figure 2 includes a graphical representation of the desired switch-signal waveforms (FF 1). Appellants Specification discloses that switch-signal 22.1 is generated by the control unit on the basis of the control signal 8 and the auxiliary ramp signal 26. The control signal 8 is inversed and subsequently crossed with the auxiliary signal 26 (see coordinate system 24.1) which results in first intersection points. These first intersection points define the switching time points of the first switch-signal 22.1 (FF 2). PWM switchsignal 22.2 is generated by the control unit 20 by crossing the control signal 8 with the auxiliary signal 26, which results in second intersection points [which] define the switching time points of the second switch-signal 22.2 (FF 2). PWM switch-signal 22.3 is disclosed as the inverse of switch-signal 22.1 (FF 2), and PWM switch-signal 22.4 is the inverse of switch-signal 22.2 (FF 2). As Appellants note (Reply Br. 3), the Specification need not disclose and preferably omits any routine technology that is well known at the time of application. Chiron, 363 F.3d at We agree with Appellants that, given the disclosure at pages 6-7 of the Specification establishing the timing for the switching points of switch-signals 22.1 and 22.2, one skilled in the art could easily make and use the present invention, perhaps program[ming] a processor or a signal generator to generate the PWM switch-signals shown in Figure 2 (Reply Br. 3). We further agree with Appellants that controllers, signal generators, [and] processors are well known and may be easily used to provide desired signals (Reply Br. 4). U.S. Patent No. 6,867,645 to Ansari cited by the Examiner in the Non-Final Rejection mailed November 15, 2005, provides evidence that the 6

7 generation of PWM switch-signals is well known in the art. Ansari teaches that the width and spacing of PWM output signal pulses are determined by one of various PWM schemes, which are shown in texts cited in the patent (FF 3). Depending on the PWM scheme selected, control signals can be generated and transmitted by a processor to the inverter bridge circuit to control the timing of the operation of the switches (FF 4). Ansari thus indicates that the generation and transmission of switch control signals is a routine matter known to those having ordinary skill in the art. Because we agree with Appellants position that one having ordinary skill in the art could make and use the invention based on the Specification, Appellants have shown error in the Examiner s rejection of independent claims 1, 8, and 11, and we will not sustain the rejection of claims 1-15 under 35 U.S.C. 112, first paragraph. CONCLUSIONS OF LAW Appellants have shown that the Examiner erred in concluding that the claimed invention is not enabled because Appellants Specification does not provide a detailed description of the manner in which control unit 20 generates PWM switch-signals 22.1 to ORDER The Examiner s rejection of claims 1-15 under 35 U.S.C. 112, first paragraph, is reversed. 7

8 REVERSED ELD PHILIPS INTELLECTUAL PROPERTY & STANDARDS P.O. BOX 3001 BRIARCLIFF MANOR, NY