As is known to all, in the practice of patent examination in China, utility model applications do not need to go through the procedure for substantive examination, and only need to pass the preliminary examination to be granted. Can it therefore also be concluded that utility model patents are more unstable and easier to be declared invalid than invention patents?
With this question, the authors performed statistics on Examination Decisions on Request for Invalidation of 92 invention patents and 221 utility model patents in the electricity field with publication dates during the half a year of May to October 2018, which are published on the official website of the Patent Reexamination Board. The statistical results are as follows: (1) Among the 92 invention patents, 55 invention patents were fully invalidated, accounting for 60%; 14 invention patents were partially invalidated, accounting for 15%; 23 invention patents were maintained valid, accounting for 25%; (2) Among the 221 utility model patents, 130 utility model patents were fully invalidated, accounting for 59%; 43 utility model patents were partially invalidated, accounting for 19%; 48 utility model patents were maintained valid, accounting for 22%.
From the above statistics alone, the rates at which invention patents and utility model patents were declared invalid are equivalent. However, it is necessary to take into account that the utility model patents only went through preliminary examination without substantive examination. Thus, some utility model patents that lack in innovation actually, the so-called “rubbish patents,” were also granted. Therefore, in these utility model patents that were declared fully or partially invalid, there are in fact a large number lacked in innovation originally but also granted. It is only natural that these patents were declared invalid since they couldn’t withstand test of references. Excluding these rubbish patents, the ratio of other relatively innovative patents being declared invalid is actually lower than the ratio in which invention patents were declared invalid. That is to say, for those utility model patents that do have innovations, in some ways, they are more stable, and less likely to be invalidated than invention patents.
The reason for this is mainly that in the invalidation procedure, the examination provisions of the inventiveness for utility model patents are different from those for invention patents. Specifically, there are two more restrictions with respect to petitioners for invalidation of utility model patents.
The first restriction is the restriction of field of prior art references. Specifically, according to the provisions in Chapter 6, Part IV, of the Guidelines for Patent Examination of State Intellectual Property Office of the People’s Republic of China, the field of prior art document for utility model patents is narrowly restricted. The examiner will “normally focus on” the technical field to which the utility model patent belongs. Only where there is a clear technical teaching, the proximate or relevant technical field may be considered.
The second restriction is the restriction of number of prior art references. Specifically, according to the provisions in Chapter 6, Part IV, of the said Guidelines for Patent Examination, for an invention patent, multiple prior art references may be cited, while for a utility model patent, it is restricted as “normally” one or two prior art references may be cited, unless the utility model patent is “made just by juxtaposing some prior art means.” Among the above 221 utility model patent invalidation cases, 127 utility model patents were declared fully or partially invalid with the cause of lacking inventiveness. A distribution of evidence combinations for independent Claim 1 is as follows: 48 cases of one piece of evidence plus common knowledge, accounting for 38%; 72 cases of two pieces of evidence (plus common knowledge), accounting for 57%; seven cases of three pieces of evidence (plus common knowledge), accounting for 5%. Thus, it t can be seen that the Patent Reexamination Board considered the factor of the number of prior art references and tried to avoid combining more than two prior art references to assess inventiveness.
In summary, compared with invention patents, petitioners for invalidation of utility model patents may only apply evidence of narrower field and less number in the invalidation procedure. From this perspective, utility model patents are more stable and less likely to be declared invalid than invention patents.