When the product claim has the feature of "bullet-proof glass for cash truck", it shows that the glass in this application has specific properties compared with "household door and window glass", which is determined by its specific microstructure, that is, bullet-proof glass for cash truck implies a microstructure with bullet-proof function, so it is different from "household door and window glass" and has novelty compared with "household door and window glass". When the use of glass is limited to "bullet-proof for armored vehicles", the glass in the claim is likely to have the same function as "household door and window glass" and will not be able to realize the function described in the application documents, so it is not novel, let alone creative.
Therefore, in the product claim, when the use restriction implies that the product has a certain function or a certain property, the judgment of novelty and creativity of the claim is influential.
At present, for the product claims with limited use, the technical scheme defined in the claim has novelty and creativity as stipulated in China's patent law because the patented product is within the protection period of the patent right. If the use restriction is not written, the claim may not have the novelty and creativity stipulated in the patent law, and then protect the known products, which is not in line with the legislative purpose of China's patent law.
In the review stage, although the tail wing and tail rotor have the same structure, their application fields (application environment) are different. Tail wing is used in aircraft, its working medium is air, tail rotor is used in submarine, and its working medium is water; Although air and water are both fluids, they have completely different characteristics and have different effects on the objects of action. So the force on the tail in the air is completely different from that on the tail rotor in the water. Therefore, the technicians in this field will not think of applying the tail rotor to the tail rotor of the aircraft. Therefore, the application of this structure of tail rotor to aircraft as tail rotor belongs to the category of modified invention, which is novel and creative as stipulated in China's patent law. On the other hand, if we don't limit the application field of empennage, it includes a wider range of empennage, and of course includes the tail rotor used on submarines in the prior art. Obviously, the patent application in this case does not possess novelty and creativity. Therefore, in the product claim, defining the theme or technical features by using the application field has an influence on the judgment of novelty and creativity (in essence, it expounds that there are specific features in the technical scheme to deal with a specific environment), that is, in the product claim, defining the application field is of great significance for determining whether the application theme meets the substantive conditions for granting patent rights stipulated in China's patent law.