legal ground
Article 27 of the Patent Law of People's Republic of China (PRC) Where an applicant applies for a patent for design, he shall submit a written request, a picture or photograph of the design, a brief description of the design and other documents. The relevant pictures or photographs submitted by the applicant shall clearly indicate the design of the product for which patent protection is required. Article 31 An application for a patent for an invention or utility model shall be limited to one invention or utility model. Two or more inventions or utility models belonging to a general inventive concept may be filed as one application. An application for a patent for design shall be limited to one design. Two or more similar designs of the same product, or two or more designs of products used in the same category and sold or used in sets, may be filed as one application.