Study On Measurement And Application For Patent Thickets Based On Valid Patents

With the rapid increase in the number of patents, the phenomenon of patent thicket is becoming increasingly serious in complex technology areas. Patent thicket is described as a dense web of overlapping patent rights, which to some extent may hinder technological innovation. Due to late start of some technologies, Chinese enterprises are easily surrounded by foreign technology leaders'patents. Chinese enterprises having to pay high patent license fees for the right to use core technologies, their technology development and production are limited. Identification is the foundation for deeply studying and actively dealing with patent thicket. Therefore, how to effectively measure patent thicket has become an urgent problem.Based on the relevant literature review, basic characteristics of patent thickets can be summarized as large quantity and density of patent, essential patents or core patents held by a number of patentees, dispersed patents, complex patent citation relations and overlapping claims. Against limitations in applicable scope and analytical perspective of existing identification methods, a modified quantitative measurement of patent thickets is proposed. According to quantity and distribution features of patents in patent thickets, the thesis takes valid invention patents as basic index. Improve existing measure methods from perspectives of patent quantity and patent dispersion so that the modified method is universal.To illustrate application of the modified method in detail, the thesis has taken patents of CDMA technology in China and U.S. as research samples. The method has been used to measure and analyze patent thickets separately. The research shows that there are large quantities of patents and patentees in the field, and core patents are held by many patentees. Patents are dispersedly distributed and have a trend of becoming increasingly dispersed. According to characteristics of patent thickets, we can see that patent thickets have existed in both Chinese and American CDMA technology field.