Print PDF

Means-Plus-Function Limitations “Short-Circuit” Summary Judgment

October 10, 2001

Decision icon Decision

Last Month at the Federal Circuit - November 2001

Judges: Bryson (author), Newman, and Archer]

In Asyst Technologies, Inc. v. Empak, Inc., No. 00-1514 (Fed. Cir. Oct. 10, 2001), the Federal Circuit reversed and remanded a district court’s decision granting SJ of noninfringement of the asserted claims.

The processing of semiconductor wafers into integrated circuits must occur in an ultraclean environment, such as a sealed transportable container, to avoid manufacturing defects. The complexity and minute dimensions involved in this processing require computer monitoring and verification systems to ensure the quality of the resulting integrated circuits.

Asyst Technologies, Inc. (“Asyst”) owns U.S. Patent Nos. 4,974,166 (“the ‘166 patent”) and  5,097,421 (“the ‘421 patent”) directed to these systems. Asyst sued Jenoptik AG and other parties (collectively “Jenoptik”) in the United States District Court for the Northern District of California, alleging infringement of the ‘166 and ‘421 patents. On Jenoptik’s motion, the district court had granted SJ of noninfringement as to the four independent claims and associated dependent claims asserted.

In its claim construction, the district court had focused on four specific means-plus-function limitations, one from each of the independent claims. The district court had held that three limitations— ”microprocessor means for receiving and processing digital information,” “workstation data processing means for receiving . . . and transporting data,” and “means for controlling . . . and for transmitting information”—all referred to a structure disclosed in the specifications of the ‘166 and ‘421 patents that included a path formed by a line directly connecting a local control processor to a two-way communication means. However, in the accused device, the analogous path included a computer, not merely a line.

Regarding the fourth limitation, the district court had held that no structure corresponded to the “means for sensing.” In this determination, the district court had rejected Asyst’s argument that a “ready, set” protocol provided the corresponding structure for the sensing function, because that protocol did not include any step that triggered sending the ready signal. As a result of these holdings, the district court had found that the accused device did not infringe the asserted claims.

On appeal, the Federal Circuit disagreed with the district court’s claim construction related to two of the means-plus-function limitations. For the “microprocessor means” limitation, the Federal Circuit found the local control processor, not the line, to be the structure that performs the receiving and processing functions. Similarly, the Court interpreted the “workstation data processing means” limitation as associating the functions recited in that claim with the local control processor due to the “data processing” language.

For the “means for controlling . . . and for transmitting information” limitation, the Federal Circuit agreed with the district court’s identification of the structure corresponding to the recited functions. However, the Federal Circuit found a genuine issue of material fact as to whether the analogous path in the accused device was equivalent to the path formed by the line.

The Court next looked at the “means for sensing” limitation, identifying the “ready, set” protocol as sufficient structure corresponding to the sensing function to give meaning to the claim. In discussing the district court’s rejection of Asyst’s argument regarding this question, the Federal Circuit noted that the recited function was “sensing,” not “initiating a sensing protocol.” As a result, the Court found it unnecessary for the specification to set forth structure to initiate the sensing protocol.

Finding the district court’s decision flawed with respect to each of the asserted independent claims, the Federal Circuit reversed the SJ of noninfringement as to all claims and remanded the case to the district court for further consideration.