Company A imitates the products of Company B, and Company B imitates the products of Company C. Now Company B has a patent that both A and C are infringing companies.

First of all, company B's patent is obtained illegally, and company C can take infringement proceedings against it; Company A and Company C may file an application for invalidation of the patent. The reason for this is the following：

1 Because Company C was imitated by Company B, the prior rights (copyright) of Company C were infringed;

Even if 1 is not considered, the design of Company B has been made public before the application date (B imitates C, that is, C is made public first), which belongs to the existing technology and does not meet the requirements of novelty and creativity in the Patent Law. Therefore, you can apply for patent invalidation.

On the premise that the patent of Company B is invalid, the imitation of Company A does not constitute infringement. (In fact, if there is only one similarity in the imitation of Company A, but it does not constitute an extremely similar product, as long as there are obvious differences, it is two different technical solutions, which does not constitute infringement).

The legal basis is as follows:

Article 23 of the Patent Law stipulates that "the design that has been granted a patent right does not belong to the existing design; Before the filing date, no unit or individual has filed an application with the patent administration department of the State Council for the same design, and it is recorded in the patent documents published after the filing date.

Compared with the existing design or the combination of existing design features, the patented design should have obvious differences.

A design that has been granted a patent right shall not conflict with the legal rights that others have obtained before the date of application.

Existing designs as mentioned in this Law refer to designs known to the public at home and abroad before the date of application. "

For reference.