Print PDF

Substitution of One Known Element for Another Renders Patent Claims Obvious

07-1554
October 10, 2008

Decision icon Decision

Last Month at the Federal Circuit - November 2008

Judges: Michel, Newman, Bryson (author)

[Appealed from: N.D. Cal., Judge Fogel]

In Asyst Technologies, Inc. v. Emtrak, Inc., No. 07-1554 (Fed. Cir. Oct. 10, 2008), the Federal Circuit affirmed the district court’s finding that the asserted claims of U.S. Patent No. 5,097,421 (“the ’421 patent”) are invalid for obviousness.

Asyst Technologies, Inc. (“Asyst”) is the assignee of the ’421 patent entitled “Intelligent Wafer Carrier.” The ’421 patent is directed to a system for tracking articles, such as silicon semiconductor wafers, in a manufacturing facility in which the wafers must be processed sequentially at a number of processing stations. The disclosed system includes transportable containers, which contain wafers that are to be transported between different manufacturing stations and allow the wafers to be maintained in a clean environment.

Asyst sued Jenoptik AG and other parties (collectively “Jenoptik”) for infringement of the ’421 patent and another patent, U.S. Patent No. 4,974,166 (“the ’166 patent”). The case had been before the Federal Circuit twice before. The district court first granted SJ of no infringement as to three of the asserted claims because the accused device lacked a simple communications means. On the first appeal, the Federal Circuit reversed the grant of SJ, holding that the trial court had erred in its claim construction. On remand, the trial court again granted SJ of noninfringement as to the claims of the ’421 patent and dismissed the claims of infringement of the ’166 patent pursuant to the parties’ agreement. Asyst appealed a second time, and the Federal Circuit affirmed the grant of SJ of no infringement of independent claim 1 of the ’421 patent, but reversed and remanded with respect to independent claim 2 and dependent claims 11-14. After the second remand, the case was tried to a jury. The jury found claims 2 and 11-14 of the ’421 patent valid and infringed. Jenoptik then moved for JMOL that the asserted claims were invalid due to obviousness, or alternatively for a new trial. After briefing on the recently decided KSR International Co. v. Teleflex, Inc. case, 127 S. Ct. 1727 (2007), the trial court granted JMOL of obviousness in view of U.S. Patent No. 4,588,880 to Hesser (“Hesser”),based in part on KSR.

On this third appeal, the Federal Circuit found that the jury’s verdict on obviousness was “plainly affected by its conclusion, expressed in the special verdict form, that Hesser was not relevant prior art.” Slip op. at 3. The Federal Circuit agreed with the district court that Hesser is “clearly pertinent to the art of tracking workpieces during multiple fabrication steps in a factory, the art to which the ’421 patent is directed.” Id. The Court also found that Asyst’s technical expert testified that Hesser was relevant prior art. Accordingly, the Court concluded that the jury erred in finding that Hesser is not prior art.

The Court next considered whether there was substantial evidence that Hesser lacks two limitations of claim 2: a “sensing means for sensing the presence of at least one transportable container,” and a “selection means for selecting between respective sensor means of said plurality.” The Court rejected Asyst’s arguments that Hesser lacked a “sensing means.” In doing so, the Court noted similarities in the communication structures disclosed by Hesser and the ’421 patent. The Court also relied on an admission by Asyst’s expert that Hesser discloses “a section that could be interpreted as sensing the presence of the information carrier.” Id. at 5. In light of these findings, the Court agreed with the district court that “any implicit finding by the jury that Hesser does not meet the ‘sensing means’ limitation of the ’421 claims was necessarily incorrect.” Id.

The Court also rejected Asyst’s argument that Hesser lacked a “selection means for selecting between respective sensor means of said plurality.” Asyst argued that, because Hesser discloses the use of an information bus instead of a multiplexer for communications between a control unit and transportable containers, it does not have any structure that performs “selection” among the containers, but instead indiscriminately transmits information through the bus to all of the transducer stations. The Court agreed with Jenoptikthat,in light of KSR, the use of a multiplexer instead of a bus did not render the invention of the ’421 patent obvious. The Court relied on the Supreme Court’s explanation in KSR that, “if a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious unless its actual application is beyond his or her skill.” Id. at 7 (quoting KSR, 127 S. Ct. at 1740). The Court found that multiplexers were well known in the art at the time of the ’421 patent and that replacing a bus with a multiplexer is “little more than ‘the simple substitution of one known element for another.’” Id. (quoting KSR, 127 S. Ct. at 1740). Thus, the Court concluded that it would be obvious to one of skill in the art to replace the bus in Hesser with a multiplexer in order to obtain the invention of the ’421 patent.

The Court next concluded that the jury’s finding that one of skill in the art would not have been motivated to combine the system of Hesser with a multiplexer in place of a bus was not supported by substantial evidence. At trial, Jenoptik introduced evidence regarding “the well-known respective advantages of a multiplexer and a bus,” and regarding “the circumstances in which one of ordinary skill would have selected one of the two devices over the other.” Id. at 8. In light of the advantages being well known, the Court rejected Asyst’s argument that the saving of battery life in its system, which uses a multiplexer instead of a bus, is an “unexpected result” that renders the asserted claim nonobvious.

The Court also rejected Asyst’s argument that the jury’s finding of objective indicia of nonobviousness—commercial success, long-felt need, and industry praise—supported its finding that the ’421 patent was nonobvious. The Court found that Asyst had failed to link the commercial success and evidence of long-felt need to the substitution of a multiplexer for a bus and, therefore, this evidence could not overcome a strong prima facie showing of obviousness.

The Court turned next to dependent claims 11-14, which the district court invalidated in view of Hesser. The Court concluded that, because Asyst had not rebutted Jenoptik’s evidence that Hesser teaches each of the additional limitations in the dependent claims, the district court was justified in overturning the jury’s verdict as to those claims.

Finally, the Court concluded that the district court did not abuse its discretion in allowing Jenoptik to assert its invalidity defense based on Hesser after ten years of litigation. The Court rejected Asyst’s argument that the delay was prejudicial, and instead found that a change in claim construction resulting from the Court’s decision in an earlier appeal “changed the rules of the game,” and that therefore Jenoptik was properly permitted to amend its defenses. Id. at 12 (quoting Johns Hopkins Univ. v. CellPro, Inc., 152 F.3d 1342, 1357 (Fed. Cir. 1988)).