Can I charge because the other company didn't apply for a patent?

For example, China's Patent Law stipulates the rational use of patent rights. One of them is to use it to develop and study new technologies. You can use someone else's patent. Of course, if the use is only for research, there is no need to pay royalties. But after development, if it is used for commercial profit, etc. You must pay a certain royalty with the consent of the patentee. If the other party disagrees without justifiable reasons, and the implementation of your new patent (if you can apply for a patent for your new invention) is based on the implementation of the other party's patent, you can apply for a compulsory license for the patent, and you can pay a reasonable royalty. This is theoretical. In practice, if the other party does not apply for a patent, then the law will not protect its technology! Just use it. Another situation is that the other party applied, but the patent application is a long process. After the application, the patented technology needs to be publicized and reviewed, and it takes more than one year to finally grant the patent right. In the meantime, if the technology is used by others, users still have to pay a certain patent fee. If the technology has been used before the other party's application, you can continue to use the technology for free after the other party's successful application, but the scale of use shall not exceed the scale used by the other party before the application. Finally, even if you accidentally infringe the patent right of the other party, don't worry too much, because as I have said, the patent law mainly adopts the principle of compensation for losses, that is to say, you only need to make up for the losses you caused, and there will be no punitive damages. In addition, whether this thing is patented or not, you can find out by going to the patent office. All the patented technologies applied for are publicly disclosed. If the patent office doesn't have it, you can use it with confidence.