DOUBLE SPEED RECORDING METHOD BY OPTICAL DISK

PURPOSE:To increase a signal processing speed and to reduce recording time by providing plural CIRC encoders and signal processing by each CIRC encoder in parallel. CONSTITUTION:Input data are divided into (n) parts and (n) signal processing sections (11, 21, ...N1) are provided. These sections consist of input processing sections (memories 12, 13, 22, 23,..., N2, N3) which convert frequencies into 1/n frequencies and output them, CIRC encoders (14, 24,..., N4) which digital- signal-process the inputs from the input processing sections and output them and output processing sections (memories 15, 16, 25, 26,..., N5, N6) which convert the inputs from the CIRC encoders into (n) times frequencies and output them. And a synthesizing circuit 17 synthesizes the inputs from the (n) signal processing sections and outputs them and an optical head 5 records the signals based on the outputs above.