## Facts

- Texas Instruments Inc. (TI) owned Japanese Patent No. 320,275 for a “semiconductor device,” commonly associated with the “Kilby patent.”
- The patent issued from a 1971 divisional (derivative) application that traced back to a 1964 original application.
- The original application had become finally rejected on the ground that the claimed invention lacked inventive step (obviousness).
- Fujitsu Ltd. manufactured and sold semiconductor devices that TI asserted infringed the Kilby patent.
- Fujitsu brought an action seeking a declaration that it owed no damages for patent infringement, contending that TI’s patent was clearly invalid in light of the earlier rejected application and related filing history.
- The lower court accepted Fujitsu’s position, finding that the invention claimed in TI’s later patent was substantially the same as the invention in the earlier application that had already been rejected for obviousness.
- TI appealed to the Supreme Court of Japan after losing in the lower courts.

## Issues

1. Whether a patent issuing from a derivative application can be enforced when its claimed invention is substantially the same as an invention in an earlier application that was finally rejected for obviousness.
2. Whether, before a Japan Patent Office (JPO) invalidation decision becomes final, a civil court may treat enforcement of a patent as impermissible when invalidity grounds are clear and invalidation is reliably expected.
3. Whether seeking an injunction, damages, or similar relief on such a patent constitutes an abuse of right absent special circumstances.

## Decision

- The Supreme Court dismissed TI’s appeal and left the judgment for Fujitsu in place.
- The Court agreed that TI’s patent claimed substantially the same invention as the invention in the earlier application that had already been rejected for obviousness, making the patent subject to invalidation.
- The Court held that even though patents are formally effective until invalidated through JPO procedures, courts hearing infringement-related disputes may determine whether invalidity grounds are clear.
- Where a patent’s invalidity grounds are clear and invalidation is reliably expected, claims for injunctions, damages, and similar remedies based on that patent are, absent special circumstances, an abuse of right and will not be allowed.

## Legal Principles

- A derivative (divisional) filing cannot be used to obtain and enforce a patent on an invention that is substantially the same as an invention in an earlier application that was finally rejected for reasons such as obviousness.
- In infringement-related litigation, a civil court may consider whether the asserted patent plainly contains invalidity grounds, even before a final JPO invalidation decision, because the court is not issuing an across-the-board invalidation judgment.
- When invalidity grounds are clear and invalidation is reliably expected, enforcing the patent through injunctions, damages, or comparable relief is treated as an abuse of right unless special circumstances justify enforcement.

## Conclusion

Texas Instruments Inc. v. Fujitsu Ltd. holds that a patent obtained through a derivative application cannot be enforced when it effectively repeats an earlier invention that was finally rejected for obviousness, and that civil courts may deny infringement remedies as an abuse of right when the patent’s invalidity is clear and invalidation is reliably expected, even before the JPO’s invalidation process has concluded.


Texas Instruments Inc. v. Fujitsu Ltd., 54 Saiko Saibansho Minji Hanreishu 1368 (Saiko Saibansho [Sup. Ct.] 2000)