Optical information recording/reproducing apparatus

Claim 1

A video on-demand system comprising a receiver-side optical disk recording and reproducing apparatus and a transmitter-side optical disk recording and reproducing apparatus interconnected by a data transmission line, said transmitter-side optical disk recording and reproducing apparatus comprising: (a) a low transfer rate recording means having an optical recording head for recording a digital program onto a first optical disk at a data record transfer rate of r bits per second, wherein r is a positive number and wherein the digital program denotes at least one of video signals, audio signals and video game software, said low transfer rate recording means including means for sequentially modulating a beam of light from the optical recording head on N divided surface regions of opposite surfaces of the first optical disk in accordance with the digital program to sequentially record N portions of the digital program at the respective N divided surface regions of the opposite surfaces of the first optical disk, wherein N is an integer greater than 1; (b) a high transfer rate reproducing means having N optical reproducing heads for simultaneously reproducing the recorded N portions of the digital program from the respective N divided surface regions of the first optical disk at a data playback transfer rate of p bits per second, wherein p is a positive number which is greater than r, said high transfer rate reproducing means including means for simultaneously applying N reproduction light beams respectively from said N optical reproducing heads to the respective N divided surface regions of the opposite surfaces of the first optical disk to simultaneously reproduce the recorded N portions of the digital program, wherein a ratio of a time for recording the digital program data by said low transfer rate recording means to a time for reproducing the digital program by said high transfer rate reproducing means is p/r; and (c) means for transmitting the digital program reproduced by said high transfer rate reproducing means on the data transmission line at a rate of p bits per second; said receiver-side optical disk recording and reproducing apparatus comprising: (a) means for receiving the digital program from the data transmission line at a rate of r' bits per second, where p=r'; (b) a high transfer rate recording means having N' optical recording heads for recording the digital program onto a second optical disk at a data record transfer rate of r' bits per second, said high transfer rate recording means including means for simultaneously modulating N' beams of light respectively from said N' optical recording heads on the second optical disk in accordance with the digital program to simultaneously record N' portions of the digital program at respective N' divided surface regions of opposite surfaces of the second optical disk, wherein N' is an integer greater than 1; and, (c) a low transfer rate reproducing means having an optical reproducing head for sequentially reproducing the recorded N' portions of the digital program from the respective N' divided surface regions of the second optical disk at a data playback transfer rate of p' bits per second during a normal reproduction mode, wherein p' is a positive number which is less than r', said low transfer rate reproducing means including means for sequentially applying a reproduction light beam from said reproducing optical head to the N' divided surface regions of the opposite surfaces of the second optical disk to sequentially reproduce the recorded N' portions of the digital program, wherein a ratio of a time for reproducing the digital program data by said low transfer rate reproducing means to a time for recording the digital program by said high transfer rate recording means is r'/p'.