Opinion ID: 4150049
Heading Depth: 2
Heading Rank: 3

Heading: The Sheets Reference

Text: Sheets is a patent assigned to AT&T/Bell Labs that discloses a microprocessor with a variable-frequency clock. The Sheets CPU conserves power by occasionally 10 TECH. PROPS. LTD. v. HUAWEI TECHS. CO., LTD. operating below its maximum frequency. The clock’s frequency correlates to the processing demands faced by the CPU. When the CPU faces a heavier processing load, its clock runs at a higher frequency. When the CPU faces a lighter load, its clock runs at a lower frequency. Sheets teaches a CPU timed by a voltage-controlled oscillator (“VCO”), which transmits the clock signal to the CPU. The CPU constantly measures its current pro- cessing load and computes an appropriate operating frequency. It communicates this information to the VCO, which throttles its frequency accordingly. The examiner initially rejected claim 6 of the ’336 patent under § 103 in light of Sheets. Like the Magar reference, the patentee traversed the rejection by arguing Sheets failed to disclose an “entire oscillator,” along the way making several statements the district court found constituted disclaimers. First, the district court noted that “the applicants distinguished their ‘present invention’ from microprocessors that rely on frequency control information from an external source.” J.A. 10 (citing the following statement from the prosecution history). The present invention does not similarly rely upon provision of frequency control information to an external clock, but instead contemplates providing a ring oscillator clock and the microprocessor within the same integrated circuit. The place- ment of these elements within the same integrat- ed circuit obviates the need for provision of the type of frequency control information described by Sheets, since the microprocessor and clock will naturally tend to vary commensurately in speed as a function of various parameters (e.g., temperature) affecting circuit performance. Sheets’ system for providing clock control signals to an external clock is thus seen to be unrelated to the TECH. PROPS. LTD. v. HUAWEI TECHS. CO., LTD. 11 integral microprocessor/clock system of the present invention. J.A. 2117. Second, addressing statements made in response to a later office action, the district court found that “the applicants went even further and disclaimed the use of controlled inputs altogether, regardless whether the control is on-chip or not.” J.A. 11 (citing the following statement from the prosecution history). Even if the Examiner is correct that the variable clock in Sheets is in the same integrated circuit as the microprocessor of system 100, that still does not give [sic] the claimed subject matter. In Sheets, a command input is required to change the clock speed. In the present invention, the clock speed varies correspondingly to variations in operating parameters of the electronic devices of the microprocessor because both the variable speed clock and the microprocessor are fabricated together in the same integrated circuit. No com- mand input is necessary to change the clock fre- quency. J.A. 2127. Third, the district court found that “the applicants left no doubt that, unlike ‘all cited references,’ the claimed oscillator is completely free of inputs and extra components.” J.A. 11 (citing the following statement from the prosecution history). Crucial to the present invention is that since both the oscillator or variable speed clock and driven device are on the same substrate, when the fabri- cation and environmental parameters vary, the oscillation or clock frequency and the frequency capability of the driven device will automatically vary together. This differs from all cited refer- ences in that the oscillator or variable speed clock and the driven device are on the same substrate, and that the oscillator or variable speed clock var12 TECH. PROPS. LTD. v. HUAWEI TECHS. CO., LTD. ies in frequency but does not require manual or programmed inputs or external or extra compo- nents to do so. J.A. 2094. The district court found that based on these statements, “[t]he applicants distinguished Sheets repeatedly on the ground that Sheets requires control signals, frequency control information or command inputs.” J.A. 16. It then held that the construction of “entire oscillator” must include the limitation “that does not require a control signal.” J.A. 7. Technology Properties appeals the district court’s construction. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1).