1. Fuzzy patent boundary: The patent right and trademark right of design overlap in some cases, which makes the patent boundary vague and difficult to define, and increases the difficulty of proving infringement in litigation.
2. The criteria for judging infringement are difficult to grasp: when judging the infringement of appearance patent, it is necessary to judge whether the infringing product is similar to the patent design, and the criteria for judging similarity are often vague and difficult to grasp. When judging the similarity, we need to consider various factors, such as the overall effect of the design and the design details of the main parts, which will also increase the difficulty of judgment.
3. Appearance patent refers to a new design that is aesthetically pleasing and suitable for industrial application based on the shape, pattern or combination of product and the combination of color and shape and pattern. The protection period of appearance patent is 10 year, and that of utility model patent is 10 year.