(1) Paper carrier is the main form of patent literature and the main object of retrieval. The materials searched by paper retrieval are generally the least error-prone and the most evidential. However, in the process of patent retrieval, it is inefficient, time-consuming, easy to be lost and damaged, and it is difficult to retrieve the latest information because of the long printing and distribution cycle.
(2) Software retrieval usually includes microfilm, computer magnetic media and CD-ROM patent literature retrieval. Microfilm patent literature has developed rapidly because of its small space, high storage density, long preservation time and easy copying. It has become one of the main means of Tibetan patent full text. Magnetic media mainly includes magnetic tape and magnetic disk, which has the advantages of high storage density, small volume, free loading and unloading and long-term storage, so it is widely used.
When digital storage technology brings CD-ROM into the field of document collection, various forms of patent database CD-ROM came into being. As a new media, CD-ROM is called "the carrier of future patent documents". With the development and popularization of computer technology, CD-ROM database has played an important role in patent retrieval and patent full-text acquisition.
(3) With the development of network technology, online patent resources are favored by users because of their unparalleled data advantages, convenient retrieval and no time and space constraints, and become the main way of patent retrieval.