The improvement of product patents can be: changes in structure, structure and device, as long as there are changes in structure or connection relationship and beneficial effects, such as a mechanism, a device, a system, a device, a component, etc. ;
The improvement of method patent can be: the improvement of process conditions, such as preparation method, synthesis method, detection method, measurement method, disassembly method, etc.
Specifically, you can check on China Applied Technology Network, hoping to help you!