Specification Limitations Can Give Meaning To Claim Terms Not Having An Ordinary Meaning

In Honeywell Int’l Inc. v. Universal Avionics Systems Corp., (No. 05-1112,-1151,-1152; May 25, 2007), the Federal Circuit vacates construction of some claim terms and remands for a new infringement determination, while affirming the district court’s retention of jurisdiction over a withdrawn claim and decision that § 102(b) does not erect a bar. Honeywell appealed the district court’s construction of five claim terms in its patents for warning pilots of impending collision with the ground.

The panel affirms the district court’s construction of two terms. Because “look ahead distance” is not a term of art, it is deemed correct to construe that term to include a time component, as described in a preferred embodiment but not specifically recited in the claim. Regarding “terrain floor boundary”, the panel also finds the term to have no ordinary meaning to a skilled artisan. Without a customary meaning, the specification is considered to supply the best context for deciphering the claim meaning, and it is correct to use general language from the specification to define the term in question. In both cases, however, the Federal Circuit disagrees with the non infringement findings.

The construction of three additional terms is found erroneous by the panel. Limiting the term “signals representative of” to instantaneous and numerical values is improper, because one of ordinary skill in the art would consider that construction too narrow. The patent does not require those limitations, says the panel, since the pilot does not directly use those signals, but rather they are used by the system’s software and can have different forms. With regard to “alert envelope”, the trial court incorrectly added a limitation that the envelope appear in the vertical plane, as found in the specification but not in the claim. One of skill in the art would agree that the claim defines the term adequately without additional limitations. The district court also included an unnecessary limitation regarding “highest H max and lowest H min” by requiring a display showing a numeric value for the highest and lowest points. Because a dependent claim added that particular limitation, the panel adheres to the presumption that the limitation is thus not present in the independent claim.