On December 1, 2023, the China National Intellectual Property Administration issued an invalidation decision No. 564872, declaring that the patent rights owned by Guangzhou Lango Electronics Technology Co.,Ltd. and entitled "A Plosive Sound Removal Device And Audio Equipment At The Audio Output End" were all invalid.

After accepting the client's entrustment, the Hengbo team conducted a large number of arduous searches and finally successfully invalidated the patent.

The decision held that a claim involving a circuit structure is in the same technical field and solves the same technical problem as evidence of the closest prior art, and the circuit structure used to solve the technical problem and the and main electronic components are basically the same. The main difference between the two is only the settings of some resistors and capacitors in the circuit. Setting voltage dividing resistors, pull-down resistors or accelerating capacitors are common methods in this field or have been disclosed by existing evidence, so this claim is obvious from the combination of the prior art.

According to legal provisions, if the patentee is dissatisfied with the invalidation decision, he can file an administrative lawsuit with the Beijing Intellectual Property Court within three months.