Hilgraeve Corp. v. McAfee Assc.

• Decision Date: 02 August 2000
• Citation: 55 USPQ2d 1656,224 F.3d 1349
• Parties: (Fed. Cir. 2000) HILGRAEVE CORPORATION, Plaintiff-Appellant, v. MCAFEE ASSOCIATES, INC. (now known as Network Associates, Inc.), Defendant-Appellee. 99-1481, -1491 DECIDED:
• Court: U.S. Court of Appeals — Federal Circuit

Page 1349

224 F.3d 1349 (Fed. Cir. 2000)

HILGRAEVE CORPORATION, Plaintiff-Appellant, v. MCAFEE ASSOCIATES, INC. (now known as Network Associates, Inc.), Defendant-Appellee.

99-1481, -1491

United States Court of Appeals for the Federal Circuit

DECIDED: August 2, 2000

On appeal from: U.S. District Court for the Eastern District of Michigan Judge Nancy G. Edmunds Ernie L. Brooks, Brooks & Kushman P.C., of Southfield, Michigan, argued for plaintiff-appellant. With him on the brief were Robert C. J. Tuttle, Thomas A. Lewry, and Frank A. Angileri.

Michael Barclay, Wilson Sonsini Goodrich & Rosati, of Palo Alto, California, argued for defendant-appellee. With him on the brief were Peter P. Chen, David L. Larson, David L. Larson, Colleen Bal, and Behrooz Shariati. Of counsel on the brief was R. Terrance Rader, Rader, Fishman & Grauer PLLC, of Boomfield Hills, Michigan.

Before MICHEL, LOURIE, and RADER, Circuit Judges.

RADER, Circuit Judge.

On summary judgment, the United States District Court for the Eastern District of Michigan determined that the VirusScan product of McAfee Associates, Inc. (MC) ^* does not literally infringe Hilgraeve Corporation's U.S. Patent No. 5,319,776 (the '776 patent). See Hilgraeve Corp. v. McAfee Assocs., Inc., 70 F. Supp. 2d 738 (E.D. Mich. 1999). The district court also estopped Hilgraeve from arguing that VirusScan infringes any claim of the '776 patent under the doctrine of equivalents. This court affirms the district court's finding that prosecution history estoppel bars application of the doctrine of equivalents. This court vacates, however, the grant of summary judgment of no literal infringement and remands for appropriate further proceedings.

I.

Hilgraeve's '776 patent, entitled "In Transit Detection of Computer Virus with Safeguard," describes a program that scans for computer viruses. The claimed invention scans a body of data during its transfer, i.e., before storage of the data with potential viruses on the destination storage medium. If the program detects signs of a virus during the scan, the program automatically blocks storage.

Claims 1 and 18 of the '776 patent are at issue. Claim 1 reads as follows, with language in dispute underlined:

1. In a system for transferring digital data for storage in a computer storage medium, a method of screening the data as it is being transferred and automatically inhibiting the storage of screened data containing at least one predefined sequence, comprising the steps of:

causing a quantity of digital data resident on a source storage medium to be transferred to a computer system having a destination storage medium; receiving and screening the transferred digital data prior to storage on the destination storage medium to determine if at least one of a plurality of predefined sequences are present in the digital data received; and in response to said screening step :

(a) automatically causing the screened digital data to be stored on said destination storage medium if none of the plurality of predefined sequences are present and

(b) automatically inhibiting the screened digital data from being stored on said destination storage medium if at least one predefined sequence is present.

'776 patent, col. 17, ll. 9-29 (emphasis added). Claim 18 reads as follows:

18. A method of preventing the spread of computer viruses to a computer having a storage medium, comprising the steps of:

simultaneously searching for a plurality of virus signatures, each of which comprising an identifiable digital sequence, while said computer is receiving a stream of digital data for storage on said storage medium;

providing an indication of the detection of a virus from said searching step; and

automatically inhibiting the storage of said digital stream on said storage medium if any of said virus signatures have been detected.

Id. at col. 28, ll. 45-57 (emphasis added). Because these claims require inhibition of storage, the district court construed the meaning of the word "storage" in the temporal context of the patent. The district court construed "storage" as occurring "when the incoming digital data is sufficiently present on the destination storage medium, and accessible by the operating system or other programs, so that any viruses contained in the data can spread and infect the computer system." Hilgraeve, 70 F. Supp. 2d at 745. This definition is consistent with the district court's interpretation of the patent claims as requiring scanning prior to storage. See id. at 748. Neither party disputes the court's claim construction.

Hilgraeve contended that McAfee's accused product, VirusScan, infringes independent claims 1 and 18 and dependent claims 2 and 6 of the '776 patent. In other words, Hilgraeve alleged that VirusScan screens incoming digital data for viruses during transfer and before "storage" on the destination storage medium. McAfee, on the other hand, asserted that VirusScan does not infringe because it screens the incoming digital data only after it has been transferred and "stored" on the destination storage medium. Thus, the critical issue in the infringement analysis is whether VirusScan screens before, or after, the time at which incoming data is present on the destination storage medium and accessible by the operating system and other programs.

To resolve this issue on summary judgment, the district court relied solely upon expert testimony about the operation of VirusScan. The district court declined to entertain a declaration and accompanying exhibits offered by one of the co-inventors of the '776 patent, terming this evidence "a thinly veiled effort to introduce expert testimony in an improper manner." Id. at 754. The district court also declined to consider McAfee promotional materials describing VirusScan. Hilgraeve asserted that these promotional materials showed that a user of VirusScan would perceive that the program operates as outlined in the claims of the '776 patent. The district court pointed out that infringement is not a question of user perception of operation, but of actual operation. Therefore it declined to consider the promotional literature. See Id. at 756.

II

This court reviews the district court's grant of McAfee's motion for summary judgment of non-infringement without deference. See Conroy v. Reebok Int'l, Ltd., 14 F.3d 1570, 1575, 29 USPQ2d 1373, 1377 (Fed. Cir. 1994). A summary judgment may stand when the record shows no genuine issues of material fact and entitlement to judgment as a matter of law. See Fed. R. Civ. P. 56(c). In granting summary judgment, the district court must draw all reasonable inferences in favor of the nonmovant. See SRI Int'l v. Matsushita Elec. Corp., 775 F.2d 1107, 1116, 227 USPQ 577, 581 (Fed. Cir. 1985) (en banc).

III.

The district court based its summary judgment on the testimony of experts who had tested VirusScan and interpreted the VirusScan code. In examining the appellate record for genuine issues of material fact, this court notes disagreements between the experts. McAfee's expert, Mr. Belgard, opined on the basis of his studies that VirusScan first stores digital data and then screens for viruses, and so does not infringe the '776 patent. Hilgraeve's expert, Dr. Geske, on the basis of his own technical studies and consideration of deposition testimony of McAfee's designated witness on infringement, Mr. Kuo, reached a different conclusion. Dr. Geske characterized Mr. Belgard's description of VirusScan's operation as over-simplified and opined that his tests were not probative on the question of infringement. Thus, Dr. Geske concluded that VirusScan infringes the '776 patent. While disagreements do not always create genuine issues of material fact, on this record the conflicting allegations of experts leaves material factual questions unanswered.

The experts described the operation of VirusScan in different ways. McAfee's expert described VirusScan's operation in terms of a sequence of steps. In this sequence, first (step 1) an application program transfers all the data for storage to a file on the destination storage medium, then (step 2) the application program makes a request for the operating system to close the file containing the transferred data. If it is operating, VirusScan intercepts (step 3) the program's request to the operating system to close the file. According to Mr. Belgard, by the time VirusScan intercepts the "close file" command, all the requested data has been transferred and stored in a designated file on the destination storage medium. Later, (step 4) VirusScan makes a call to the operating system to close the file on behalf of the application program. Now, critically to McAfee, (step 5) the operating system closes the file, releases the transferred digital data that it has maintained on behalf of the application program, and returns control back to VirusScan. McAfee's expert asserted, on the basis of his testing, that at this point the operating system has made all the data transferred to the file available to the computer system. In other words, the destination storage medium - e.g., a hard disk drive - has already completely "stored" the data, as the district court defined "stored." In this description, because VirusScan permits storage, the operating system and all other application programs can copy and execute the file even if it contains a virus. According to McAfee, VirusScan only scans for viruses in the next step, (step 6). If VirusScan detects no viruses, it then returns control (step 7) to the application program. If it detects a virus (step 8), VirusScan calls the operating system to delete the file or perform a user-selectable option. Finally, (step 9) the operating system responds to the VirusScan call and deletes the file or performs the selected option.

McAfee thus based its defense on step 5 and the immediately preceding steps. According to McAfee's expert, step 5 concludes the process of "storage" as the district...