## Facts

- Lawrence B. Lockwood owned three patents (U.S. Patent Re. 32,115; U.S. Patent 4,567,359; U.S. Patent 5,309,355) directed to automated, interactive sales terminals that present information and permit ordering of goods and services.
- American Airlines operated computerized airline reservation systems, including SABRE and SABREvision, used by travel agents to access fare and schedule information, book itineraries, and display travel-related images for consumers.
- Lockwood alleged SABREvision infringed claims of all three patents.
- The district court granted summary judgment for American, holding: (i) the ’115 and ’359 patents were not infringed; (ii) asserted claims of the ’355 patent were invalid and not infringed; and (iii) asserted claims of the ’359 patent were invalid as obvious under 35 U.S.C. § 103.
- The appeal focused on claim construction (including terms such as “self-contained,” “audio-visual,” “customer,” and “means for accepting payment”), infringement (literal and equivalents), and validity (obviousness, anticipation, and entitlement to priority under 35 U.S.C. § 120).

## Issues

1. Whether, under proper claim construction, SABREvision literally infringed asserted claims of the ’115, ’359, or ’355 patents.
2. Whether prosecution history estoppel barred infringement under the doctrine of equivalents.
3. Whether asserted claims of the ’359 patent were obvious under 35 U.S.C. § 103 in view of prior art, including the SABRE system and another patent.
4. Whether the ’355 patent was invalid under 35 U.S.C. § 102 because it was not entitled to an earlier filing date under 35 U.S.C. § 120 due to inadequate written description support.
5. Whether any genuine disputes of material fact precluded summary judgment.

## Decision

- The Federal Circuit affirmed summary judgment for American.
- The court upheld constructions limiting the asserted claims to specific terminal architecture and structural features, and held SABREvision did not meet those limitations; thus, there was no literal infringement of the ’115, ’359, or ’355 patent claims at issue.
- The court agreed that prosecution history estoppel foreclosed Lockwood’s attempt to extend claim scope under the doctrine of equivalents to cover features surrendered during prosecution.
- The court affirmed invalidity of the asserted ’359 patent claims as obvious under § 103, treating SABRE’s publicly known functions as prior art and finding the combination with other prior art sufficient to establish obviousness.
- The court affirmed invalidity of the ’355 patent under § 102 because Lockwood could not claim § 120 priority; the earlier application failed the written description requirement for the later-claimed subject matter.
- The court found no genuine issues of material fact and held American was entitled to judgment as a matter of law.

## Legal Principles

- Claim terms are construed in view of the specification and prosecution history, and may be limited to particular structural implementations rather than broad concepts.
- Noninfringement is established when an accused system lacks claim-required structural or functional limitations under the proper construction.
- Prosecution history estoppel bars use of the doctrine of equivalents to recapture subject matter surrendered through narrowing amendments or clear arguments made to obtain allowance.
- A widely used commercial computer system can qualify as prior art based on public accessibility of its functions, even absent traditional printed publications.
- Obviousness under 35 U.S.C. § 103 may be resolved on summary judgment when the prior art teachings and the absence of a material factual dispute support invalidity as a matter of law.
- Priority under 35 U.S.C. § 120 requires that the earlier application satisfy the written description requirement for the later-claimed invention; failure to do so can forfeit the earlier filing date and expose claims to anticipation under § 102.

## Conclusion

The Federal Circuit affirmed summary judgment that American’s SABREvision system did not infringe Lockwood’s asserted claims and that key claims were invalid, concluding that the claims were properly construed narrowly, prosecution history barred equivalents theories, SABRE functioned as prior art supporting obviousness of the ’359 patent, and the ’355 patent failed for lack of § 120 written description support.


Lockwood v. Am. Airlines, Inc., 107 F.3d 1565 (Fed. Cir. 1997)