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Find a Japanese Prior Art about True Random Number Generator for Game Machines

The scope of this project is to search prior art in the area of random number generator and RN generation method for game machines and computers.

Search language:

Japanese documents published prior to 1998

Databases used:
Patent databases: NRI, IPDL and Patolis.
Non-patent literature databases: JSTPlus (JDream-II), G-Search, and other supplemental databases including READ, NINii, GENii, Kaken; and Internet search.


In our first trial, we searched the concept of “true random number generator OR generation method” for Japanese patent documents.

Then we extended the scope to cover "random number generator OR generation method".
In these searches, a total of 1896 hits were generated.

In the non-patent literature searches, we identified 3 key Japanese manufacturers for physical random number generators: Hitachi, Toshiba, and FDK. 4 Japanese documents that disclose true random number generators having verification function are uncovered. The physical random number generator, RPG100, developed and marketed by FDK in 2003, has a built-in verification function for verifying the random numbers generated. RPG100 can be mounted to a computer via PCI connection. A modified version, RPG102, is a USB module type true random number generator.

40+ patent documents that disclose “random number generator or generation method by using noise sources” were uncovered after the first round of screening. In the Japanese patent searches for “random number generators or generation methods”, 864 hits were generated. After screening and reviewing full documents of these hits, 7 patent documents that are considered to be relevant art were uncovered.

Searching for an infringement litigation case in the area of random number generators for computers and game machines

Both patent and non-patent literature were covered.