Optical information processing apparatus with peak hold circuit for gain control signal

Claim 3

An apparatus according to claim 1, wherein said apparatus comprises means for selectively recording and reproducing the information, and said selecting means comprises means for selecting the output of said light quantity means which has not been held by said holding means, during recording, and means for selecting the output of said light quantity detecting means which has been held by said holding means, during reproducing.

Claim 4

An apparatus according to claim 2, wherein said selecting means further comprises means for shifting the output of said light quantity detecting means from the output which has not been held by said holding means to the output which has been held by said holding means, with a predetermined delay time after recording changes to reproducing.

Claim 5

An apparatus according to claim 2, wherein said apparatus further comprises means for erasing the information recorded on the optical recording medium, and said selecting means further comprises means for selecting the output of said light quantity detecting means which has not been held by said holding means, during erasing.

Claim 6

An apparatus according to claim 4, wherein said selecting means further comprises means for shifting the output of said light quantity detecting means from the output which has not been held by said holding means to the output which has been held by said holding means, with a predetermined delay time after erasing changes to reproducing.

Claim 7

An apparatus according to claim 1, wherein said error detecting means comprises a photoelectric converter element having a plurality of divided light receiving surfaces, and a circuit for differentiating outputs from said light receiving surfaces from one another.

Claim 8

An apparatus according to claim 6, wherein said light quantity detecting means comprises a circuit for adding the output of said light receiving surfaces of said photoelectric converter element.

Claim 9

An apparatus according to claim 1, wherein said holding means comprises a peak hold circuit.

Claim 10

An apparatus according to claim 1, further comprising switching means for connecting or disconnecting an input from said light quantity detecting means to said holding means.

Claim 11

An apparatus according to claim 1, further comprising an optical system for condensing the light beam on the optical recording medium, and wherein said adjusting means comprises an actuator for driving at least a portion of said optical system.

Claim 14

An apparatus according to claim 11, wherein said second switching means comprises means for shifting the output of said light quantity detecting means from the output which has been held by said holding means to the output which has not been held by said holding means, with a predetermined delay time after said tracking control circuit changes from the inoperative condition to the operative condition.

Claim 15

An apparatus according to claim 11, wherein said focusing error detecting means and said tracking error detecting means comprises a photoelectric converter element having a plurality of divided light receiving surfaces, and a circuit for differentiating outputs from said light receiving surfaces from one another.

Claim 16

An apparatus according to claim 13, wherein said light quantity detecting means comprises a circuit for adding the outputs of said light receiving surfaces of said photoelectric converter element.

Claim 17

An apparatus according to claim 11, wherein said holding means comprises a peak hold circuit.

Claim 18

An apparatus according to claim 15, further comprising third switching means for connecting or disconnecting an input from said light quantity detecting means to said holding means.

Claim 19

An apparatus according to claim 11, further comprising an optical system for condensing the light beam on the optical recording medium, and wherein at least one of said focusing adjusting means and said tracking adjusting means comprises an actuator for driving at least a portion of said optical system.

Claim 20

An optical information processing apparatus comprising: a light source for emitting a light beam; an optical system for condensing the light beam emitted from said light source on an optical recording medium; an actuator for driving at least a portion of said optical system to change focusing and/or tracking conditions of the light beam; an error detector for detecting a focusing and/or a tracking error signal from light of the light beam reflected or transmitted by the optical recording medium; a feedback control circuit for feeding an output from said error detector back to said actuator; a light quantity detector for detecting light quantity of the reflected or transmitted light; a gain control circuit for controlling gain of said feedback control circuit in accordance with an output of said light quantity detector; a holding circuit for holding an output of said light quantity detector; and a selecting circuit for selecting one of the output of said light quantity detector which has been held by said holding circuit and an output of said light quantity detector which has not held by said holding circuit, corresponding to a predetermined condition; wherein said gain control circuit controls the gain of said feedback control circuit in accordance with the output of said light quantity detector selected by said selecting circuit.

Claim 21

An optical information processing apparatus comprising: a light source for emitting a light beam; an optical system for condensing the light beam emitted from said light source on an optical recording medium; an actuator for driving at least a portion of said optical system to change focusing and/or tracking conditions of the light beam; an error detector for detecting a focusing and/or a tracking error signal from light of the light beam reflected or transmitted by the optical recording medium; a feedback control circuit for feeding an output from said error detector back to said actuator; a light quantity detector for detecting light quantity of the reflected or transmitted light; a gain control circuit for controlling gain of said feedback control circuit in accordance with an output of said light quantity detector; a holding circuit for holding an output of said light quantity detector; and a selecting circuit for selecting one of the output of said light quantity detector which has been held by said holding circuit and an output of said light quantity detector which has not held by said holding circuit, corresponding to a predetermined condition; wherein said gain control circuit controls the gain of said feedback control circuit in accordance with the output of said light quantity detector selected by said selecting circuit.

Claim 22

An apparatus according to claim 18, wherein said apparatus further comprises means for selectively recording and reproducing the information, and said selecting circuit comprises means for selecting the output of said light quantity detector which has not been held during recording and for selecting the output of said light quantity detector which has been held, during reproducing.

Claim 23

An apparatus according to claim 19, wherein said selecting circuit further comprises means for shifting the output of said light quantity detector from the output which has not been held by said holding circuit to the output which has been held by said holding circuit, with a predetermined delay time after recording changes to reproducing.

Claim 24

An apparatus according to claim 19, wherein said apparatus further comprises means for erasing the information recorded on said optical recording medium, and said selecting circuit further comprises means for selecting the output of said light quantity detector which has not been held by said holding circuit, during erasing.

Claim 25

An apparatus according to claim 21, wherein said selecting circuit further comprises means for shifting the output which has not been held by said holding circuit to the output which has been held by said holding circuit, with a predetermined delay time after erasing changes to reproducing.

Claim 26

An apparatus according to claim 18, wherein said error detector comprises a photoelectric converter element having a plurality of divided light receiving surfaces, and a circuit for differentiating outputs from said light receiving surfaces from one another.

Claim 27

An apparatus according to claim 23, wherein said light quantity detector comprises a circuit for adding the outputs of said light receiving surfaces of said photoelectric converter element.

Claim 28

An apparatus according to claim 18, wherein said holding circuit comprises means for holding a peak value of the output of said light quantity detector.

Claim 29

An apparatus according to claim 18, further comprising a switch for connecting or disconnecting an input from said light quantity detector to said holding circuit.

Claim 30

An optical information processing apparatus comprising: a light source for emitting a light beam; an optical system for condensing the light beam emitted from said light source on an optical recording medium; a focusing actuator for driving at least a portion of said optical system to change a focusing condition of the light beam; a focusing error detector for detecting a focusing error signal from light of the light beam reflected or transmitted by the optical recording medium; a focusing control circuit for feeding an output from said error detector back to said focusing actuator; a tracking actuator for driving at least a portion of said optical system to change a tracking condition of the light beam; a tracking error detector for detecting a tracking error signal from light of the light beam reflected or transmitted by the optical recording medium; a tracking control circuit for feeding an output from said tracking error detector back to said tracking actuator; a first switching circuit for selectively rendering said tracking control circuit to one of an operative condition and an inoperative condition; a light quantity detector for detecting light quantity of the reflected or transmitted light; a gain control circuit for controlling gain of said focusing and/or tracking control circuits in accordance with an output of said light quantity detector; a holding circuit for holding an output of said light quantity detector; and a second switching circuit for selecting one of the output of said light quantity detector which has been held by said holding circuit and an output of said light quantity detector which has not held by said holding circuit, corresponding to the operative condition and the inoperative condition of said tracking control circuit; wherein said gain control circuit controls the gain of said feedback control circuit in accordance with the output of said light quantity detector selected by said second switching circuit.

Claim 31

An optical information processing apparatus comprising: a light source for emitting a light beam; an optical system for condensing the light beam emitted from said light source on an optical recording medium; a focusing actuator for driving at least a portion of said optical system to change a focusing condition of the light beam; a focusing error detector for detecting a focusing error signal from light of the light beam reflected or transmitted by the optical recording medium; a focusing control circuit for feeding an output from said error detector back to said focusing actuator; a tracking actuator for driving at least a portion of said optical system to change a tracking condition of the light beam; a tracking error detector for detecting a tracking error signal from light of the light beam reflected or transmitted by the optical recording medium; a tracking control circuit for feeding an output from said tracking error detector back to said tracking actuator; a first switching circuit for selectively rendering said tracking control circuit to one of an operative condition and an inoperative condition; a light quantity detector for detecting light quantity of the reflected or transmitted light; a gain control circuit for controlling gain of said focusing and/or tracking control circuits in accordance with an output of said light quantity detector; a holding circuit for holding an output of said light quantity detector; and a second switching circuit for selecting one of the output of said light quantity detector which has been held by said holding circuit and an output of said light quantity detector which has not held by said holding circuit, corresponding to the operative condition and the inoperative condition of said tracking control circuit; wherein said gain control circuit controls the gain of said feedback control circuit in accordance with the output of said light quantity detector selected by said second switching circuit.

Claim 32

An apparatus according to claim 27, wherein said second switching circuit comprises means for shifting the output of said light quantity detector from the output which has been held by said holding circuit to the output which has not been held by said holding circuit, with a predetermined delay time after said tracking control circuit changes from the inoperative condition to the operative condition.

Claim 33

An apparatus according to claim 27, wherein said focusing error detector and said tracking error detector comprise a photoelectric converter element having a plurality of divided light receiving surfaces, and a circuit for differentiating outputs from said light receiving surfaces from one another.

Claim 34

An apparatus according to claim 29, wherein said light quantity detector comprises a circuit for adding the outputs of said light receiving surfaces of said photoelectric converter element.

Claim 35

An apparatus according to claim 27, wherein said holding circuit comprises means for holding a peak value of the output of said light quantity detector.

Claim 36

An apparatus according to claim 31, further comprising a third switching circuit for connecting or disconnecting an input from said light quantity detector to said holding circuit.