Difference between existing technology and patent law

This is the same concept as the "existing technology" in the patent law, and it also contains the technical background referred to in the specification. The existing technology is no longer novel, so it is impossible to apply for a patent. For the patent application filed after 2009- 10- 1 (including that day), according to the definition of the revised patent law, "existing technology" refers to the technology known to the public at home and abroad before the filing date.