1. Log in to official website, China National Intellectual Property Administration. You can enter the patent number to be queried in official website, and query whether the patent can be pledged, partially pledged or not. The query result can be displayed on the electronic terminal.
2. To consult with professional service organizations, you can entrust professional intellectual property agencies or professional service organizations to make inquiries. This method has the advantages of high accuracy and simple operation.
3. Consult friends and professional forums. Usually, professionals in the field of intellectual property rights or friends who are willing to answer questions for others for free have rich knowledge of patent pledge. By consulting these people or forums, you can get effective information.
Please note that the above method is only applicable to the inquiry of patent pledge registration. If you need more detailed information or know more about patent pledge, I suggest you consult a professional or consult relevant materials.