Castillo v. Mungcal [1990] 90 O.G. 4194, 4198

 Facts:

Plaintiff Gerardo S. Castillo has been manufacturing and selling gas filter and filter drier under the trademark “Diamond”. Defendant Mungcal was one of his customers.

Defendant who is engaged in refrigeration and airconditioning made an improvement of the existing gas filter and gas filter drier made by Castillo. He applied for a utility model patent for the improvement which he invented on existing filter driers and strainers. He was assured by the Patent Office that he can apply for a patent for his improvement, after which he set up a small manufacturing establishment under the name Master Drier Manufacturing. He then started manufacturing and sold filter driers and strainers under his brand name “Klean Aire”

The application for utility patent for the filter driers was approved by the Philippine Patent Office and defendant was issued Utility Model Patent No. 5412.

Likewise, during the pendency of the case, the defendant applied for patents to cover the strainers. The application was however denied because the improvement in his strainers were substantially the same and had no patentable novelty over that of his improvement in his filter driers.

Issue: Was there patent infringement?

Ruling:

The court held that the products of the plaintiff and the defendant have distinguishing features.

Even if a device serves the same function as another device, there is no infringement if it lacks the features, methods or arrangements of the other device.