OPTICAL INFORMATION AND RECORDING DEVICE

• Main Authors: KITAI HIROTO, HOSOYA HIDEKI, SHIKICHI SATOSHI
• Format: Patent
• Language: English
• Published: 27.11.1987
• Subjects: INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; PHYSICS

PURPOSE:To attain the automatic track locking accurately and quickly by providing a control system vibrating an objective lens in a direction crossing a track and starting track servo while the spot corresponds to a prescribed track. CONSTITUTION:Three two split sensors 101-103 are provided to three spots and the tracking spot is formed on the sensor 103. When the spot is at the outside of the track, both photodetection sections of the sensor 103 have equal luminous quantity, a differential output 12 is '0', a control circuit 17 closes a stetch 16a and opens a stetch 16b, a vibrating voltage is inputted from a point Q to drive a coil 111 and the lens 110 is vibrated in the track lateral cross direction. Outputs of sensor amplifiers 11a, 11b are unequal at the track crossing (d) of the spot, the differential output 12 is detected by the control circuit 17 at a prescribed level, switch contacts 16a, 16b are switched and the differential output 12 is inputted from a point P to a drive amplifier 14 via a buffer 13. Thus, the automatic track servo control is applied to an objective track to complete the AT locking. The information is recorded in this state succeedingly.