Apparatus for recording on and playback from both sides of a disk shaped recording medium

An apparatus for simultaneous recording on and playback from opposite first and second surfaces of a disk-shaped recording medium having respective first and second information tracks, the first and second surfaces being divided into respective pluralities of first and second sectors, each sector having its own sector address, comprising:

• first and second scanners that respectively scan the first and second surfaces of said disk-shaped recording medium for recording and playback;
• first and second buffer memories that delay data, respectively;
• first and second modems that respectively demodulate playback signals read by said first and second scanners to output demodulated playback signals to said first and second buffer memories, and that modulate recording signals from said first and second buffer memories to output modulated recording signals to said first and second scanners;
• a change-over switching means that delivers recording signals to said first and second buffer memories and combines demodulated playback signals from said first and second buffer memories by switching a data flow according to an operation mode of said apparatus;
• first and second address reading means that respectively demodulate first and second sector addresses respectively read by said first and second scanners;
• an address conversion means that detects a positional relationship between the first sectors on the first surface and the second sectors on the second surface of said disk-shaped recording medium from the first and second sector addresses read by said first and second address reading means and converts the second sector addresses read by said second address reading means into converted second sector addresses according to a preset conversion rule which defines a manner of converting the second sector addresses into the converted second sector addresses based on said detected positional relationship;
• a recording-playback control means that individually outputs instructions for recording and playback to said first and second modems at specified sector addresses using the first sector addresses read by said first address reading means and the converted second sector addresses converted by said address conversion means;
• and
• a memory controller that controls directions of data flows and delay amounts of data in said first and second buffer memories to equalize a difference between delay amounts of said first and second buffer memories with a time difference between instructions for recording and playback output from said recording-playback control means to said first and second modems.

An apparatus for simultaneous recording on and playback from opposite first and second surfaces of a disk-shaped recording medium having respective first and second information tracks, the first and second surfaces being divided into respective pluralities of first and second sectors, each sector having its own sector address, comprising:

• first and second scanners that respectively scan the first and second surfaces of said disk-shaped recording medium for recording and playback;
• first and second modems that individually demodulate playback signals read by said first and second scanners and modulate recording signals to output modulated recording signals to said first and second scanners;
• first and second address reading means that individually demodulate first and second sector addresses respectively read by said first and second scanners;
• and
• a recording-playback control means that detects a positional relationship between the first sectors on the first surface and the second sectors on the second surface of said disk-shaped recording medium, and respectively outputs instructions for playback to said first and second modems as two sector addresses, one of the two sector addresses being chosen as a reference sector address based on said detected positional relationship.