## Facts

- Howard A. Fromson owned U.S. Patent No. 3,181,461, claiming a process for making photographic lithographic printing plates using anodized aluminum treated with an aqueous alkali metal silicate to create a water-insoluble, hydrophilic, organophobic surface layer, followed by diazo coating and exposure.
- Defendants (including Advance Offset Plate, Inc.) made lithographic plates using an anodized aluminum base, sodium silicate treatment, and diazo coating/exposure in a broadly similar process.
- Several asserted claims described the silicate-treatment step as a “reaction” producing a “reaction product,” with some claims referring to “aluminosilicate” and others describing the required surface layer primarily by functional characteristics (water-insoluble, hydrophilic, organophobic).
- The district court credited defendants’ expert testimony that the accused plates had no “reaction product of aluminum oxide and silicate” and instead had a silica coating.
- Based on that view, the district court entered multiple judgments of no direct infringement and no contributory infringement.

## Issues

1. Whether the district court improperly construed “reaction”/“reaction product” (and related “aluminosilicate” language) to require a particular, chemically characterized aluminosilicate compound not demanded by the claims read in light of the intrinsic record.
2. Whether the noninfringement and no-contributory-infringement judgments could stand where they were premised on that construction and on treating chemical-label testimony as dispositive of claim scope.

## Decision

- The Federal Circuit vacated the judgments of no infringement and no contributory infringement and remanded.
- The court held the district court’s construction was legally erroneous because it narrowed “reaction/reaction product” to a specific aluminosilicate compound inconsistent with the claims, specification, and prosecution history.
- Because the infringement findings depended on that erroneous construction and an overly restrictive view of what the claims required, the findings could not stand and required reconsideration under the correct construction.

## Legal Principles

- Claim terms must be construed primarily from the intrinsic record (claims, specification, and prosecution history), and courts may not import unrecited limitations from embodiments or explanatory passages.
- Patent claims drafted in terms of process and results are not confined to a single scientific theory or to a requirement that the patentee prove the exact chemical identity of a hypothesized reaction product.
- Expert testimony describing the accused product’s chemistry cannot redefine claim scope; chemical nomenclature disputes (e.g., “silica” versus “aluminosilicate”) do not resolve infringement if the claims do not require that specific chemical identification.
- When a noninfringement judgment rests on an unduly narrow claim construction, the proper remedy is vacatur and remand for infringement analysis under the correct construction.

## Conclusion

The Federal Circuit vacated the district court’s noninfringement and no-contributory-infringement judgments because the claims were improperly restricted to a particular aluminosilicate “reaction product,” and it remanded for a new infringement determination applying a construction tied to the intrinsic record and the functional requirements stated in the claims.


Fromson v. Advance Offset Plate, Inc., 720 F.2d 1565 (Fed. Cir. 1983)