July 2014
Finding of Anticipation Reversed When a Value Is Affected by Other Indeterminate Sources
| Judges: Rader, Moore, Reyna (author) |
| [Appealed from Board] |
In In re Rambus, Inc., No. 13-1192 (Fed. Cir. June 4, 2014), the Federal Circuit reversed the Board’s finding that claims 26 and 28 of U.S. Patent No. 6,426,916 (“the ’916 patent”) were anticipated by U.S. Patent No. 4,734,909 to Bennett (“the Bennett patent”).
The ’916 patent discloses a method and system for improving the efficiency of computer memory. In particular, the ’916 patent is addressed to improving a memory transfer system between different memory devices. The transfer may occur over a series of wires called a “bus.” Signals transferred over a bus can be either “multiplexed” or “dedicated,” depending on the device. When two memory devices want to send data over the same bus, a process called “arbitration” determines which memory device goes first. The ’916 patent attempts to improve memory transfer systems using an external clock to synchronize the timing of data transfers and, for a particular transfer request, delaying the transfer by a specific, known amount of time.
During inter partes reexamination, the examiner found that the Bennett patent did not disclose “a value that is representative of an amount of time to transpire after which the memory device outputs the first amount of data.” Slip op. at 4. On appeal to the Board, the Board reversed the examiner’s finding and determined that a value, Parameter VI, of the Bennett patent disclosed this amount of time, and that the Bennett patent anticipated claims 26 and 28 of the ’916 patent. Rambus, Inc. (“Rambus”) appealed.
“A value cannot ‘represent’ an ‘amount of time’ if there are additional factors, wholly unrepresented by that value, that necessarily impact, or represent, the ‘amount of time.’” Slip op. at 8.
On appeal, the Federal Circuit reversed the Board’s anticipation finding. The Court first noted that because the reexamination proceeding involved claims of an expired patent, the claim construction standard from Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005), applied instead of the broadest reasonable interpretation.
The Court then reviewed the Board’s finding of anticipation. The Court discussed and rejected the Board’s finding that Figures 25a and 25b of the Bennett patent included a known delay of one clock cycle before data transfer. The Court agreed with Rambus that Figure 25a represented a simplified, hypothetical illustration of how the Bennett patent’s invention worked in theory and was not a schematic of how the Bennett patent works. The Court explained that Parameter VI of the Bennett patent represented only one source of delay and that the actual delay can be longer due to other factors. The Court reasoned that changing the value of Parameter VI did not necessarily create a one-clock-cycle delay because the arbitration of the Bennett patent may take an indefinite amount of time if a memory device loses arbitration on successive occasions. The Court also noted that a memory device having dedicated lines may also have a longer delay than one having multiplexed lines due to wait signals. Based on these “two additional, indefinite, sources of delay,” the Court concluded that changing the value of Parameter VI did not produce a set amount of time after which the data is transferred. Slip op. at 8. The Court then held that Parameter VI of the Bennett patent was not “‘representative’ of an amount of time after which data is transferred,” as recited in claim 26 of the ’916 patent. Id.
Next, the Court considered the Board’s finding that some embodiments of the Bennett patent met the claim limitation at issue. The Court rejected the Board’s finding, reasoning that “[a] value cannot ‘represent’ an ‘amount of time’ if there are additional factors, wholly unrepresented by that value, that necessarily impact, or represent, the ‘amount of time.’” Id. The Court then reversed the Board’s finding that the Bennett patent anticipated claims 26 and 28 of the ’916 patent.
