“Gas Appliance”


The Intellectual Property High Court (IP High Court) holds a patent as valid over the prior art, upholding a prior trial decision.

Main Issue:

Whether gaps 1 and 2 in Plaintiff’s Evidence 1 are equivalent to the “opening” claimed in the defendant’s patent.

Summary of Conclusion:

The claim at issue concerns a heating appliance that uses a gas canister. The court considered the technical concept of the defendant’s claimed invention to be directed to the enhancement of cooling performance, in that when a small gas canister has been set within a main body of the appliance, an opening for removing an end of a standard gas canister from the main body of the appliance provides an air inlet, causing a sufficient airflow therein. As such, the court held that the “opening” as claimed, should be viewed as one that is able to function as an “air inlet” so as to enhance cooling performance by causing sufficient airflow within the main body of the appliance once a small gas canister has been set therein.


The court further held that even considering gaps 1 and 2 as disclosed in the drawings of Plaintiff’s Evidence 1 (gaps that are formed between cover member 5 and rear surface cover member 6), Plaintiff’s Evidence 1 neither teaches nor suggests the technical concept of the defendant’s invention of enhancing cooling performance, by introducing air through gaps 1 and 2, and that additionally, gaps 1 and 2 illustrated in the drawings are both small. The court considered that it would therefore be inconceivable that one of ordinary skill in the art would discern, based on the drawings of Evidence 1, that cooling performance could be enhanced by introducing air through gaps 1 and 2.
The court concluded that it cannot be said that Plaintiff’s Evidence 1 discloses features identical or substantially identical to the claim at issue.


The plaintiff (initiator of the invalidation trial) argued, for example, that the mechanical configuration in Evidence 1 enables a mode of use whereby a rear surface side of the canister compartment 8 is opened up, and that such a mode of use is known and commonly used in the art. However, the court dismissed these arguments, indicating that Plaintiff’s Evidence 1 teaches nothing whatsoever about opening up a rear surface cover member while using a specially-made small gas canister 2A.