Patent literature:
    According to the definition of World Intellectual Property Organization (WIPO), the patent literature is the general name for relevant data which contain the research and development and test results that have been applied or confirmed to be discovery, utility model and industrial design as well as published or unpublished documents of materials which protect the right of the inventor and the patentee.
   Generally, the patent literature mainly refers to the official publications of the patent office of each country, including patent specification, patent gazette, patent abstract, patent index, patent classification table, etc. It should be noted that the patent specification in the new application stage could either be a disclosed literature or undisclosed  information (still kept confidential).

Types of patent:
    Patent is divided into three kinds, i.e. invention, utility model and industrial design in china.
    Invention—means the new technical scheme put forward for a product, a method or its improvement such as the manufacturing method or process for the product, the material formula, the drug formula, etc.
     Utility model—means the new applicable technical scheme put forward for the shape, construction or their combination of a product, usually referred to as “little invention” in practice.
    Industrial design—means new design which is made according to the shape, pattern or their combination as well as the combination of color, shape and pattern, and is applicable to industrial application. Here the “appearance” like the packaging case, the packaging bag and the packaging box, is emphasized.