On January 23, 2020, the China National Intellectual Property Administration (hereinafter referred as CNIPA) issued an invalidation decision No. 43195, declaring that all patent rights of the utility model, entitled "device for monitoring pantograph slide", which were owned by Chengdu Tangyuan Electric Co., Ltd. were invalid (The picture is for reference only and has nothing to do with the above patent).

On August 21, 2019, the Hengbo team accepted the client's commission and conducted a large number of searches on prior arts related to the above-mentioned patent. It was found that there were prior arts in patent literature that were similar to the patent involved, based on which, a request for invalidation was filed. After nearly six months of trial, CNIPA finally made a decision to declare that the patent was in entirety invalid.

According to the law, the patentee, who is dissatisfied with the invalidation decision, can file an administrative lawsuit request with the Beijing Intellectual Property Court within three months.

The detailed content of the invalidation decision can be found in the Annex: Invalidation Decision No. 43195.