The principle of singleness, also known as the "one application, one invention" principle, means that a patent application can only be filed for one invention.
It is worth noting that although the principle of singularity does not allow for more than two inventions in a single patent application, it does allow for inventions that are "part of a general idea" or "related", "related" or "interdependent" technical solutions. In the case of designs, it is permissible to apply for patents on more than two designs "used in the same class and sold or used in sets" in a single application. The term "in the same class" means that the products belong to the same category in the classification table; and "sold or used in sets" means that all the products are of the same design or conception and are customarily sold and used at the same time.
It may be regarded as a plurality of inventions belonging to the general concept of invention in a patent application for an invention:
(i) two or more independent claims to the same kind of product or method which cannot be included in a single claim;
(ii) an independent claim to the product and to the method of making the product;
(3) an independent claim to the product and to the product's use;
(iv) an independent claim to the product, a method dedicated to the manufacture of the product, and the use of the product;
(v) an independent claim to the product, a method dedicated to the manufacture of the product, and equipment specifically designed to carry out the method;
(6) an independent claim to the method and equipment specifically designed to carry out the method.
2. Principle of Writing
The various formalities provided for in the Patent Law and these Rules shall be in writing. The form of writing here is the principle of writing. The principle refers to the patent application process, the patent applicant and his agent in the handling of various formalities should be in writing.
3. The principle of first to apply
The principle of first to apply means that more than two people applied for a patent on the same invention, the patent right is granted to the first person to apply for a patent.