An optical information recording-reproducing method and an apparatus using the method

Claim 2

An optical information recording-reproducing method according to claim 1, further comprising the steps of: generating a focusing error signal from the output signals of the divided sensor; comparing the focusing error signal with a predetermined value; and stopping movement of the objective lens while the position servo is operative, based on a result of said comparing step.

Claim 3

An optical information recording-reproducing method in which a light spot is applied through an objective lens on to an optical information recording medium, which has a plurality of tracks, and the light spot is moved relative to the recording medium while tracking control is conducted so that at least one of recording, reproducing and erasing of information is effected on the recording medium, said method comprising the steps of: receiving light reflected from the recording medium by a divided sensor; adding at least a portion of output signals of the divided sensor to generate a sum signal; detecting whether the light spot is located on one of the tracks, using the sum signal, at the time of a draw-in of the tracking control; generating a tracking error signal in accordance with the output signals of the divided sensor; comparing the tracking error signal with a predetermined value; and operating the tracking control based on a comparison result obtained in said comparing step and a detection result obtained in said detecting step, at the time of the draw-in of the tracking control.

Claim 4

An optical information recording-reproducing method according to claim 3, wherein the predetermined value is equal to zero.

Claim 5

An optical information recording-reproducing apparatus in which a light spot is applied through an objective lens onto an optical information recording medium, and the light spot is moved relative to the recording medium while focusing control is conducted so that at least one of recording, reproducing and erasing of information is effected on the recording medium, said apparatus comprising: a divided sensor for receiving light reflected from the recording medium and for producing output signals; adding means for receiving the output signals from saint divided sensor and for adding at least a portion of the output signals to generate a sum signal; driving signal generating means for generating a predetermined driving signal for moving the objective lens in its optical axis direction; a position servo circuit for receiving the sum signal and the drive signal and for moving the objective lens in its optical axis direction in accordance with these signals and for generating a position servo circuit control signal; focusing error signal generating means for receiving the output signals of said divided sensor and for generating a focusing error signal in accordance with the output signals; a focusing control circuit for receiving the focus error signal and for driving said objective lens so that the light spot is in an in-focus state on the recording medium and for generating a focusing control circuit control signal; and selecting means for receiving the position servo circuit and focusing control circuit control signals, and for rendering inoperative said focusing control circuit when said position servo circuit is operative, while rendering inoperative said position servo circuit when said focusing control circuit is operative, at the time of a draw-in of the focusing control.

Claim 6

An optical information recording-reproducing apparatus in which a light spot is applied through an objective lens onto an optical information recording medium, which has a plurality of tracks, and the light spot is moved relative to the recording medium while a tracking control is conducted so that at least one of recording, reproducing and erasing of information is effected on the recording medium, said apparatus comprising: a divided sensor for receiving light reflected from the recording medium and for producing output signals; sum signal generating means for receiving the output signals from said divided sensor and for adding at least a portion of the output signals to generate a sum signal; tracking error signal generating means for generating a tracking error signal in accordance with the output signals of said divided sensor; a tracking control circuit for receiving the sum signal and the tracking error signal and for moving the objective lens so that the light spot is located on the track in accordance with these signals; detecting means for receiving the sum signal and for detecting if the light spot is located on the track in accordance with the sum signal and for generating a detection result; comparing means for receiving the tracking error signal and for comparing the tracking error signal with a predetermined value and for generating a comparison result; and control means for making operative said tracking control circuit based on the comparison result obtained by said comparing means and the detection result obtained by said detecting means, at the time of a draw-in of the tracking control.

Claim 7

An optical information recording-reproducing apparatus according to claim 6, wherein the predetermined value is equal to zero.

Claim 8

An optical recording and/or reproducing apparatus including: means for directing a light beam onto an optical recording medium; divided sensor means for sensing light reflected from a plurality of regions of the recording medium; and means for using signals indicative of the output of the sensor means resulting from light reflected from at least two regions to control the focussing and/or the tracking of the light beam on the recording medium.

Claim 9

An optical recording and/or reproducing method including the steps of: directing a light beam onto an optical recording medium; sensing light reflected from a plurality of regions of the recording medium; and using signals indicative of the sensed light from at least two regions to control the focussing and/or the tracking of the light beam on the recording medium.