Practice question
In a patent-infringement case, the defendant establishes a ground that could support cancellation under Section 61. Can that invalidity be raised as a defense?
- Never, grant makes validity unchallengeable
- Only after paying the plaintiff every demanded royalty
- Only if the defendant is an inventor
- Only a private arbitrator may consider it
- Yes, Section 81 expressly permits the identified invalidity defense
Legal references
- RA 8293, Sections 81-82: https://lawphil.net/statutes/repacts/ra1997/ra_8293_1997.html
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