What value can be used after the patent is invalid?

The essence of a patent is to make it public for a certain period of time, so your patent was made public at the time of authorization (the invention is before authorization), but you have the monopoly right during the protection period, and others need your consent to use your patent, otherwise it will be regarded as infringement. If your patent is invalid, then you lose the monopoly right and anyone can continue to use it, so there is actually no residual value. The only residual value is that the right holder knows the patent better and can continue to improve it before applying for a patent.