What fields does the invention patent cover?

There is no difference between invention patent and field. The definition of invention in the second paragraph of Article 2 of China's Patent Law is: "Invention refers to a new technical scheme proposed for a product, method or its improvement."

The so-called products refer to all kinds of new products that can be manufactured in industry, including solids, liquids and gases with certain shapes and structures. The so-called method refers to the method of processing raw materials and making various products. The invention patent does not seek the technical achievements that can be directly applied to industrial production through practice, but it can be a solution to technical problems or an idea with the possibility of industrial application. However, this technical scheme or idea cannot be confused with a simple topic or idea, because a simple topic or idea does not have the possibility of industrial application.