US Patent 7349935 Random number generation apparatus

In this invention, a random number generation apparatus inputs unperiodic random noise n generated by a noise source 1 to a waveform shaping circuit 2 to generate a random pulse wave P1. Next, the random number generation apparatus inputs the random pulse wave P1 and a clock c1 from an oscillator 3 to a sample-and-hold circuit 4 to generate a constant periodic binary pulse sequence P2. Subsequently, the binary pulse sequence P2 and a half divided clock c2, which is the clock c1 half divided by the divider 5, are inputted to a switching circuit 6, and the polarity of the binary pulse sequence P2 is reversed at intervals of one period to output a smoothed binary pulse sequence P3 in which appearance balance of 1/0 code is smoothed.