Information processing method and apparatus therefor in which an erasing device is driven for a period longer than a necessary period

An apparatus for selectively effecting recording of information on and erasing of recorded information from a magneto-optical recording medium that includes a sector having a recording area and a defined front gap portion and a defined rear gap portion respectively located before and after the recording area on the medium, said apparatus comprising:

• a light source for emitting a light beam to irradiate the recording medium;
• moving means for relatively moving the light beam and the recording medium to scanningly irradiate the sector of the medium with the light beam;
• applying means for selectively applying a magnetic field to the medium in a predetermined direction and in a direction opposite to the predetermined direction;
• a driving circuit for driving said light source and for intensity modulating the light beam emitted from said light source;
• a modulation circuit for supplying to said driving circuit a signal modulated according to recording information;
• and
• a gate control circuit for selectively supplying to said driving circuit a first gate signal during information recording and a second gate signal during information erasing, respectively, the first gate signal having a length corresponding to an interval during which the light beam scanningly irradiates the recording area of the recording medium and the second gate signal being longer than the first gate signal,
• wherein said driving circuit intensity-modulates the light beam according to the signal supplied from said modulation circuit during an interval in which the first gate signal is supplied to said driving circuit from said gate control circuit, the second gate signal having a length corresponding to an entire interval during which the light beam, at a predetermined intensity level sufficient to completely erase recorded information, scanningly irradiates the medium from the front gap portion, through the recording area and into the rear gap portion, and said driving circuit causes said light source to emit the light beam to irradiate the recording medium at the predetermined intensity during the entire interval in which the second gate signal is supplied to said driving circuit from said gate control circuit, to completely erase recorded information even if errors occur in on and off timing of the light beam.