With a patent certificate, you can also be accused of infringement.

First of all, you don't understand the patent system in China. Infringement is a comparative judgment between the plaintiff's patented products and the defendant's infringing products, which has nothing to do with whether the defendant's infringing products have patents. If the defendant owns a patent for the infringing product and it is before the plaintiff's patent application date, the defendant may declare the plaintiff's patent invalid. In the process of invalidation, the court will suspend the lawsuit and wait for the invalidation result of the reexamination Committee to make a judgment. But if you apply for a patent later, then this patent has no influence on the infringement lawsuit.

Secondly, you still have a misunderstanding about your question 1, that is, as long as I have a patent, I can produce it at will, and there is no infringement. Same as above, you still confuse invalidation with tort litigation. Question 1 Your question is why I was convicted of infringement after owning a patent? No matter how many patents you apply for later, as long as the products you produce fall within the protection scope of the plaintiff's prior patents, you will be sentenced to infringement, which has nothing to do with this. Of course, you can solve the infringement problem by invalidating the patent of the other party through the invalidation procedure.

Your question 2, because there is no substantive examination of the utility model patent in China, that is to say, the Patent Office did not search it during the examination, and did not examine whether the patent you applied for is creative, which is the reason why the utility model patent right is unstable. The reason for your question 2 is that you already had the same patent application before you applied. No matter how many patents you apply for later, as long as the products you produce are within the scope of previous patents, they are regarded as infringement. As for the patentee applying for a patent, what's the use? How can it be useless? If your technology is creative enough that no one has applied before, you can use it to defend your rights. As you mentioned, the plaintiff's factory won the rights through patents.

Question 3. As I have made it clear before, infringement is to compare the other party's patented products with the infringing products you produce. It has nothing to do with whether your infringing products are patented or not. The patent of the other party may be declared invalid through the invalidation procedure.

Finally, I suggest you consult a professional firm.