A kokai or kokai tokkyo koho is a published, unexamined Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

ese patent application

Patent application

A patent application is a request pending at a patent office for the grant of a patent for the invention described and claimed by that application. An application consists of a description of the invention , together with official forms and correspondence relating to the application...

, in contrast to the kokoku

Kokoku (patent law)

A kokoku or kokoku tokkyo koho is an examined and approved Japanese patent application, published for opposition, in contrast to the kokai, the published , unexamined Japanese patent application....

or tokkyo koho, the examined and approved Japanese patent application. Kokai means "open to the public", or "laid-open". Kokai are published eighteen months after the earliest priority

Paris Convention for the Protection of Industrial Property

The Paris Convention for the Protection of Industrial Property, signed in Paris, France, on March 20, 1883, was one of the first intellectual property treaties. It established a Union for the protection of industrial property...

date.

Tokukai is another shorthand for "kokai tokkyo koho". Tokkyo (patent) + kokai (open to the public) = tokukai.