JP2006147076A - Optical disk device and optical pickup control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk device capable of measuring an offset voltage with high accuracy during reproduction or recording operation, and to provide an optical pickup control device. <P>SOLUTION: The optical disk device comprises; an optical pickup 25 for temporarily interrupting emission of a laser beam based on a 1st timing signal TS1; a differential amplifier circuit 11 for amplifying a difference between a monitor voltage MS and a reference voltage as an output power setting reference and producing a differential amplification voltage DS; an adder circuit 14 which adds the differential amplification voltage DS and a DC bias voltage BS and producing a laser power control voltage CS for controlling output power of the laser beam; a bias voltage producing circuit 15a for producing the DC bias voltage BS; and switch circuitry 13 which interrupts supply of the differential amplification voltage DS to the adder circuit 14 for the period in which the emission of the laser beam is temporarily interrupted, and which transmits the differential amplification voltage DS to the adder circuit 14 according to resumption of the laser beam emission. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical disc device having an offset voltage measurement function and an optical pickup control device.

  During the reproducing operation of the optical disk apparatus, the semiconductor laser element in the optical pickup irradiates the optical disk with laser light through the objective lens, and the reflected light is photoelectrically converted to perform a reading operation. The output power of the laser light emitted from the semiconductor laser element is detected by a monitor element in the optical pickup, and a laser power control circuit outside the optical pickup performs feedback loop control to keep the output power of the laser light constant. Further, output currents of a plurality of photodetectors that perform photoelectric conversion are converted into voltages, and error signals, full addition signals, and the like are generated. A circuit that performs current / voltage conversion, a circuit that generates an error signal, a full addition signal, and the like are usually mounted as an analog circuit using an operational amplifier. In general, an operational amplifier has a DC offset (hereinafter referred to as “offset voltage”) in the output even when there is no input. Therefore, it is necessary to measure the offset voltage of the operational amplifier and perform correction based on the measured value. The measurement of the offset voltage is performed in a state where the semiconductor laser element is not emitted before the start of reproduction or recording (see, for example, Patent Documents 1 and 2). Since there is a possibility that a correct offset voltage cannot be measured due to the influence of noise or the like in one measurement, in order to measure the offset voltage with high accuracy, an average value is calculated by measuring an offset voltage of about 128 samples. There is a need.

  In recent years, recordable optical disk devices have been widely used, and the laser power emitted from the semiconductor laser element during recording has increased in proportion to the improvement in recording speed. As a result, the temperature in the optical pickup rises, and the change in the offset voltage becomes larger during the recording operation. Therefore, even if the offset voltage is corrected once, an error occurs in the correction amount due to a temperature change during operation. Accordingly, it is preferable to measure the offset voltage by temporarily stopping the emission of the semiconductor laser element during operation.

However, considering the loop band of the focus servo control for controlling the objective lens in the optical pickup, the time during which the emission of the semiconductor laser element can be stopped and the position of the objective lens can be maintained is about 500 [μs]. On the other hand, the loop band of the laser power control circuit is 10 [kHz] or less, and in the operation in which the semiconductor laser element is turned off for a moment and then re-emitted, the laser light is actually output power based on the response time of the circuit. A delay time of 200 [μs] or more is generated until the process returns to (1). Furthermore, when the laser beam is turned off, the offset voltage cannot be measured because the signal level before turning off remains as an integral response for a time of about 100 [μs] due to the response time due to the band of the operational amplifier. Therefore, the time during which the offset voltage can actually be measured within the period in which the focus servo can be maintained is 200 [μs] or less. Therefore, when the offset voltage is measured at the sampling frequency of 88.2 [kHz], it is 17 samples or less, and the accuracy is reduced to about 1/8.
JP-A-2-91827 Japanese Patent Laid-Open No. 2-98831

  The present invention provides an optical disc apparatus and an optical pickup control apparatus that can measure an offset voltage with high accuracy during a reproducing or recording operation.

  According to one aspect of the present invention, (a) light that emits laser light to an optical disc, generates a monitor voltage according to the output power of the laser light, and temporarily interrupts the emission of the laser light based on the first timing signal Pickup; (b) A differential amplifier circuit that amplifies the difference between the monitor voltage and the reference voltage that becomes the output power setting reference and generates a differential amplification voltage; (c) Adds the difference amplification voltage and the DC bias voltage An addition circuit for generating a laser power control voltage for controlling the output power; (d) a bias voltage generation circuit for generating a DC bias voltage; (e) laser light emission is temporarily interrupted based on the second timing signal; A switching circuit that interrupts the supply of the differential amplification voltage to the addition circuit during the period and transmits the differential amplification voltage to the addition circuit in response to the restart of the emission of the laser beam; And summarized in that an optical disc apparatus comprising a controller for generating a second timing signal.

  According to one aspect of the present invention, (a) the difference between a monitor voltage generated when the optical pickup detects the output power of the laser light emitted from the optical pickup and a reference voltage that is a reference for setting the output power is amplified. Differential amplifier circuit for generating a differential amplification voltage; (b) addition circuit for adding a differential amplification voltage and a DC bias voltage to generate a laser power control voltage for controlling the output power (c) generating a DC bias voltage (D) supply of the differential amplification voltage to the adder circuit is interrupted during a period in which the laser light emission is temporarily interrupted, and the differential circuit is differentially amplified in response to the restart of the laser light emission. The gist of the present invention is an optical pickup control device including a switch circuit for transmitting a voltage.

  ADVANTAGE OF THE INVENTION According to this invention, the optical disk apparatus and optical pick-up control apparatus which can measure an offset voltage with high precision during reproduction | regeneration or recording operation can be provided.

  Next, first and second embodiments of the present invention will be described with reference to the drawings. In the descriptions of the drawings in the first and second embodiments, the same or similar parts are denoted by the same or similar reference numerals.

(First embodiment)
As shown in FIG. 1, the optical disc apparatus according to the first embodiment of the present invention includes an optical disc 3, an optical pickup 25 that irradiates the optical disc 3 with laser light, and an optical pickup control device 26a that controls the optical pickup 25. Prepare. The optical pickup control device 26a includes an error signal generation circuit 17, a compensation circuit 18, a full addition signal generation circuit 20, an analog / digital (A / D) conversion circuit 21a, an actuator drive circuit 19, a controller 22a, and a laser power control circuit 16a. Is provided. Further, the laser power control circuit 16a includes a differential amplifier circuit 11, a reference voltage generation circuit 12a, a switch circuit 13, a bias voltage generation circuit 15a, and an addition circuit 14. The optical pickup 25 emits laser light to the optical disc 3, generates a monitor voltage MS corresponding to the output power of the laser light, and temporarily interrupts the emission of the laser light based on the first timing signal TS1. The differential amplifier circuit 11 amplifies a difference between the monitor voltage MS and a reference voltage RS that is a setting reference for output power, and generates a differential amplified voltage DS. The adder circuit 14 adds the differential amplification voltage DS and the DC bias voltage BS to generate a laser power control voltage CS that controls the output power of the laser beam. The bias voltage generation circuit 15a generates a DC bias voltage BS. Based on the second timing signal TS2, the switch circuit 13 suspends the supply of the differential amplification voltage DS to the adder circuit 14 during a period in which the laser light emission is temporarily interrupted, and adds it in response to the restart of the laser light emission. The differential amplification voltage DS is transmitted to the circuit 14. The controller 22a generates a first timing signal TS1 and a second timing signal TS2. The reference voltage generation circuit 12a generates a reference voltage RS.

  The input of the differential amplifier circuit 11 is connected to the reference voltage generation circuit 12 a and the monitor voltage generation circuit 7 in the optical pickup 25. The switch circuit 13 has an input connected to the differential amplifier circuit 11 and the controller 22a, and an output connected to the adder circuit 14. The adder circuit 14 has inputs connected to the switch circuit 13 and the bias voltage generation circuit 15 a, and has an output connected to the laser drive circuit 9 in the optical pickup 25. The laser voltage is output so that the monitor voltage MS generated by the monitor voltage generation circuit 7 becomes the same potential as the reference voltage RS by the feedback loop formed by the monitor voltage generation circuit 7, the laser power control circuit 16a, and the laser drive circuit 9. Power is kept constant.

  The voltage value of the DC bias voltage BS is the laser power control voltage CS when the switch circuit 13 is turned on during the emission of laser light, and the voltage SS is 0 [V] when the switch circuit 13 is turned off. The laser power control voltage CS in this case is preset to a value that is substantially equal.

  In addition to the monitor voltage generation circuit 7 and the laser drive circuit 9, the optical pickup 25 includes a semiconductor laser element 1, a monitor element 6, a half mirror 10, an objective lens 2, a magnetic actuator 8, and a plurality of optical detectors 4a, 4b, ... Includes a plurality of current / voltage (I / V) conversion circuits 5a, 5a,. As the semiconductor laser element 1, for example, a laser diode can be used. As the monitor element 6, for example, a monitor diode can be used. The semiconductor laser element 1 has an anode connected to the output of the laser drive circuit 9 and a cathode grounded. The monitor element 6 is disposed in the vicinity of the semiconductor laser element 1, and an anode is connected to an input of the monitor voltage generation circuit 7, and a cathode is grounded. The inputs of the plurality of I / V conversion circuits 5a, 5a,... Are connected to the outputs of the plurality of photodetectors 4a, 4b,.

  The laser drive circuit 9 supplies a drive current corresponding to the laser power control voltage CS to the semiconductor laser element 1. The output power of the laser beam emitted from the semiconductor laser element 1 is controlled by the drive current generated by the laser drive circuit 9. The monitor element 6 generates a current corresponding to the output power of the laser beam emitted from the semiconductor laser element 1. The monitor voltage generation circuit 7 converts the current from the monitor element 6 into a voltage and generates a monitor voltage MS. The objective lens 2 focuses the laser beam emitted from the semiconductor laser element 1 on the recording surface of the optical disc 3. The magnetic actuator 8 is controlled by the actuator drive circuit 19 to finely adjust the position of the objective lens 2. The half mirror 10 changes the optical path of the laser light reflected by the optical disc 3. The plurality of photodetectors 4a, 4b,... Detect the laser beam from the half mirror 10 and generate a current corresponding to the amount of light. The plurality of I / V conversion circuits 5a, 5a,... Convert the current output from the plurality of photodetectors 4a, 4b,.

  Further, the error signal generation circuit 17 and the full addition signal generation circuit 20 are respectively connected between the outputs of the plurality of I / V conversion circuits 5a, 5a,... And the input of the A / D conversion circuit 21a. The The compensation circuit 18 has an input connected to the A / D conversion circuit 21 a and the controller 22 a, and an output connected to the actuator drive circuit 19. Alternatively, when the compensation circuit 18 is configured by an analog circuit, the output of the error signal generation circuit 17 is connected to the input of the compensation circuit 18.

  Further, the error signal generation circuit 17 electrically calculates an error between the current position of the objective lens 2 and a desired position to move the objective lens 2 from the outputs of the plurality of I / V conversion circuits 5a, 5a,. Error signal ES1 is generated. The full addition signal generation circuit 20 adds the outputs of the plurality of I / V conversion circuits 5a, 5a,... To generate a full addition signal AS. The A / D conversion circuit 21a converts the error signal ES1 and the full addition signal AS, which are analog signals, into digital signals. The compensation circuit 18 performs phase compensation and gain compensation of the error signal ES2 converted into a digital signal, and generates an actuator control signal ACS. The actuator drive circuit 19 amplifies the actuator control signal ACS and drives the magnetic actuator 8 to control the position of the objective lens 2. The error signal generation circuit 17, the A / D conversion circuit 21a, the compensation circuit 18, and the actuator drive circuit 19 constitute a focus servo loop.

  Note that the A / D conversion circuit 21a receives a plurality of I / V conversion circuits 5a, 5a,... From the error signal ES1 and the full addition signal AS during a period in which the emission of the laser beam is temporarily interrupted. The offset voltages of the error signal generation circuit 17 and the full addition signal generation circuit 20 are measured. That is, at the time of measuring the offset voltage, the respective outputs are taken in as digital data without the input of the error signal generation circuit 17 and the full addition signal generation circuit 20. Therefore, the laser beam emitted from the semiconductor laser element 1 is stopped, and the error signal ES1 and the full addition signal AS are converted into digital data in a state where the laser beam is not incident on the plurality of photodetectors 4a, 4b,. It is captured. For example, the average value of the measured offset voltage is calculated by the compensation circuit 18 and stored as offset data. The stored offset data is used for offset voltage correction.

  Further, the controller 22a controls the operation timing of the laser drive circuit 9 using the first timing signal TS1, and controls the operation timing of the switch circuit 13 and the compensation circuit 18 using the second timing signal TS2. The first timing signal TS1 is a signal for forcibly stopping the operation of the laser driving circuit 9. For example, the emission of laser light is interrupted during a period when the first timing signal TS1 is at a high level.

  On the other hand, the second timing signal TS2 is a signal for controlling the fixing of the actuator control signal ACS generated by the compensation circuit 18 and the on / off of the switch circuit 13. For example, the actuator control signal ACS generated by the compensation circuit 18 is fixed while the second timing signal TS2 is at a high level. Therefore, the position of the objective lens 2 is maintained while the semiconductor laser element 1 is off, and it is possible to prevent the position of the objective lens 2 from being greatly displaced after the laser light is re-emitted.

  Further, the switch circuit 13 is turned off while the second timing signal TS2 is at a high level, and the second timing signal TS2 is turned on when the second timing signal TS2 is at a low level while the second timing signal TS2 is at a low level.

  Next, the operation of the optical disc apparatus according to the first embodiment will be described with reference to the flowchart shown in FIG. 2 and the time chart shown in FIG. However, as a comparative example, when the switch circuit 13, the addition circuit 14, and the bias voltage generation circuit 15 a shown in FIG. 1 are not provided, that is, the differential amplification voltage DS generated by the differential amplification circuit 11 is directly supplied to the laser drive circuit 9. Each signal waveform in such a case is shown by broken lines in FIGS.

  (A) During the normal operation of step S11 shown in FIG. 2, the first timing signal TS1 and the second timing signal TS2 are at the low level as shown in the period from time t0 to t1 in FIGS. It is. Since the first timing signal TS1 is at a low level, the laser drive circuit 9 shown in FIG. 1 supplies a drive current to the semiconductor laser element 1 based on the laser power control voltage CS. Since the second timing signal TS2 is at a low level, the switch circuit 13 is kept on, and the differential amplification voltage DS generated by the differential amplifier circuit 11 is transmitted to the adder circuit 14. The compensation circuit 18 performs gain compensation and phase compensation on the error signal ES2 converted into a digital signal and supplies the error signal ES2 to the actuator drive circuit 19.

  (B) When the offset voltage measurement process is started in step S12, the controller 22a obtains the first timing signal TS1 and the second timing signal TS2 as shown at time t1 in FIGS. Raise from low level to high level. When the first timing signal TS1 rises to a high level, the supply of drive current to the semiconductor laser element 1 is interrupted, and the emission of laser light is interrupted. When the emission of the laser beam is interrupted, the monitor voltage MS decreases at time t1 in FIG. As a result, the difference between the monitor voltage MS and the reference voltage RS shown in FIG. 3D increases, and the voltage value of the differential amplification voltage DS significantly increases at time t1 in FIG. Further, when the second timing signal TS2 rises to a high level, the switch circuit 13 is turned off. Therefore, the output voltage SS of the switch circuit 13 becomes 0 [V] at time t1 in FIG. At this time, since the DC bias voltage BS shown in FIG. 3 (g) is continuously supplied to the adding circuit 14, the voltage value of the laser power control voltage CS is as shown in FIG. 3 (h). The voltage value before the first timing signal TS1 shown becomes high can be maintained. Furthermore, the position of the objective lens 2 is fixed by fixing the actuator control signal ACS generated by the compensation circuit 18.

  (C) In step S13, the A / D conversion circuit 21a samples the error signal ES1 and the full addition signal AS while the emission of the laser beam by the semiconductor laser element 1 is off. Here, the A / D conversion circuit 21a measures an offset voltage of about 128 samples, for example. The compensation circuit 18 calculates the average value of the measured offset voltage as offset data. Note that the offset data may be calculated after restarting the emission of the laser beam as long as the offset voltage sampling is completed.

  (D) In step S14, the controller 22a causes the first timing signal TS1 to fall from the high level to the low level as shown at time t2 in FIG. When the first timing signal TS1 falls from the high level to the low level, the laser driving circuit 9 resumes driving of the semiconductor laser element 1, and the laser light is re-emitted. As shown in FIG. 3 (h), the laser power control voltage CS is maintained at a voltage value substantially equal to the voltage value before the first timing signal TS1 becomes high level. At this time, the switch circuit 13 is in an off state, and the objective lens 2 is in a fixed state. On the other hand, in the comparative example, since the differential amplification voltage DS shown in FIG. 3 (e) is the maximum value, the output power of the laser beam becomes the maximum level, and the monitor voltage MS is set as shown by the broken line in FIG. It has increased significantly. When the fixing of the position of the objective lens 2 is released in this state, the error signal ES1 becomes very large due to an increase in the output power of the laser beam. Therefore, an abnormality occurs in the focus servo, and position control for the objective lens 2 is performed. Operation becomes unstable. Therefore, in the comparative example, the operation of the compensation circuit 18 cannot be resumed until the time when the output power of the laser beam is stabilized, that is, about time t4 in FIG. 3, and the position of the objective lens 2 can be stably held 500. The period of about [μs] will be exceeded.

  (E) In step S15, the controller 22a considers the response time of the differential amplifier circuit 11, and falls the timing signal TS2 from the high level to the low level at the timing when the differential amplification voltage DS returns to the almost original voltage value. The response time of the differential amplifier circuit 11 is determined by, for example, the standard of the differential amplifier circuit 11 to be mounted. When the timing signal TS2 falls from the high level to the low level at time t3 in FIG. 3B, the switch circuit 13 is turned on and the fixation of the objective lens 2 is released. When the switch circuit 13 is turned on, the differentially amplified voltage DS is supplied to the adder circuit 14, and the feedback loop is configured again. At this time, as shown in FIG. 3F, a slight transient response appears in the output signal SS of the switch circuit 13, but it returns to the original voltage value.

  Further, due to the setting error of the DC bias voltage BS shown in FIG. 3 (g) and the response speed of the laser power control circuit 16a, the laser power control voltage CS shown in FIG. 3 (h) is delayed until it returns to the original voltage value. However, the delay can be shortened as compared with the comparative example. As described above, according to the first embodiment, it is possible to suppress the transient response that occurs at the time of restarting the emission of the laser light in a short time, and therefore, the offset voltage is set within the period in which the position of the objective lens 2 can be held. It can be measured sufficiently. Therefore, it is possible to provide an optical disc device and an optical pickup control device that can measure an offset voltage with high accuracy during a reproducing or recording operation.

(Modification of the first embodiment)
As shown in FIG. 4 as an optical disk apparatus according to a modification of the first embodiment, the output of the controller 22b may be connected to the respective inputs of the reference voltage generation circuit 12b and the bias voltage generation circuit 15b. The controller 22b sets the voltage values of the reference voltage RS and the DC bias voltage BS using, for example, digital signals. In this case, an A / D conversion circuit can be used as the reference voltage generation circuit 12b and the bias voltage generation circuit 15b. The controller 22b holds a plurality of sets of voltage value data of the reference voltage RS and the DC bias voltage BS, and selects the optimum voltage value of the reference voltage RS and the DC bias voltage BS according to the type of optical disk and the reproduction / recording speed. Are set in the reference voltage generation circuit 12b and the bias voltage generation circuit 15b.

(Second Embodiment)
The optical disc apparatus according to the second embodiment of the present invention is different from FIG. 1 in that the output of the adder circuit 14 is connected to the input of the A / D conversion circuit 21b as shown in FIG. 1 is different from FIG. 1 in that the output of the controller 22c is connected to the input of the bias voltage generation circuit 15b. As shown in step S21 of FIG. 6, the controller 22c detects the voltage value of the laser power control voltage CS during the period in which the emission of the laser beam is maintained, and the gain of the adding circuit 14 and the voltage of the laser power control voltage CS are detected. Based on the value, the voltage value of the DC bias voltage BS is calculated. The calculated voltage value is set in the bias voltage generation circuit 15b. Other configurations are the same as those in FIG.

  As described above, when the setting of the DC bias voltage BS is inappropriate, the transient response when restarting the emission of the laser light is increased. On the other hand, in FIG. 5, the laser power control voltage CS is converted into digital data by the A / D conversion circuit 21b, so that the controller 22c can measure the voltage value of the laser power control voltage CS.

Here, when the voltage value of the laser power control voltage CS is CS [V] and the gain (amplification factor) of the adding circuit 14 is G, the optimum voltage value BS [V] of the DC bias voltage BS is:
BS = CS / G (1)
Is calculated by

  As described above, according to the second embodiment, it is possible to minimize the transient response when the laser light is re-emitted, and the delay until the laser power control voltage CS returns to the original level is reduced. This can be shortened compared to the first embodiment.

(Modification of the second embodiment)
As shown in FIG. 7 as an optical pickup control device 26c according to a modification of the second embodiment of the present invention, the output of the differential amplifier circuit 11 may be connected to the input of the A / D conversion circuit 21c. . The A / D conversion circuit 21c converts the differential amplification voltage DS into digital data and transmits it to the controller 22d. The controller 22d controls the voltage value of the DC bias voltage BS so that the differential amplification voltage DS generated by the differential amplifier circuit 11 becomes 0 [V]. Furthermore, the controller 22d sets the voltage value of the DC bias voltage BS at which the differential amplification voltage DS becomes 0 [V] in the bias voltage generation circuit 15b.

  As a result, similar to the second embodiment, it is possible to minimize the transient response when the laser light is re-emitted, and the delay until the laser power control voltage CS returns to the original level can be shortened. .

(Other embodiments)
As described above, the present invention has been described according to the first and second embodiments. However, it should not be understood that the description and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, the laser power control circuit 16a, the error signal generation circuit 17, and the full addition signal generation circuit 20 shown in FIG. 1 are mounted as analog circuits, and the A / D conversion circuit 21a and the compensation circuit 18 are mounted as digital circuits. The analog circuit and the digital circuit can be monolithically integrated on the semiconductor chip, and can be configured as separate semiconductor integrated circuits. Alternatively, the laser power control circuit 16a, the error signal generation circuit 17, the full addition signal generation circuit 20, the A / D conversion circuit 21a, and the compensation circuit 18 are monolithically integrated on the same semiconductor chip by an analog / digital mixed process. May be.

  Thus, it should be understood that the present invention includes various embodiments and the like not described herein. Therefore, the present invention is limited only by the invention specifying matters in the scope of claims reasonable from this disclosure.

1 is a block diagram illustrating a configuration example of an optical disc device according to a first embodiment. It is a flowchart which shows operation | movement of the optical pick-up control apparatus which concerns on 1st Embodiment. It is a time chart which shows the specific operation | movement of the optical pick-up control apparatus which concerns on 1st Embodiment. It is a block diagram which shows the structure of the optical pick-up control apparatus which concerns on the modification of 1st Embodiment. It is a block diagram which shows the structural example of the optical disk apparatus which concerns on 2nd Embodiment. It is a flowchart which shows operation | movement of the optical pick-up control apparatus which concerns on 2nd Embodiment. It is a block diagram which shows the structural example of the optical disk apparatus which concerns on the modification of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Objective lens 11 ... Differential amplifier circuit 13 ... Switch circuit 14 ... Adder circuit 15a, 15b ... Bias voltage generation circuit 16a-16c ... Laser power control circuit 18 ... Compensation circuit 22a-22c ... Controller 25 ... Optical pick-up 26a-26c ... Optical pickup control device

Claims (6)

An optical pickup that emits laser light to an optical disc, generates a monitor voltage according to the output power of the laser light, and temporarily interrupts the emission of the laser light based on a first timing signal;
A differential amplifying circuit for amplifying a difference between the monitor voltage and a reference voltage serving as a setting reference for the output power, and generating a differential amplified voltage;
An adding circuit for adding the differential amplification voltage and the DC bias voltage to generate a laser power control voltage for controlling the output power;
A bias voltage generation circuit for generating the DC bias voltage;
Based on the second timing signal, the supply of the differential amplification voltage to the adder circuit is interrupted during a period in which the emission of the laser beam is temporarily interrupted, and the adder circuit is activated in response to the restart of the emission of the laser beam. A switch circuit for transmitting the differential amplification voltage;
An optical disc apparatus comprising: a controller that generates the first and second timing signals.   Based on the second timing signal, the position of the objective lens in the optical pickup is fixed during the interrupted period, and an error between the current position of the objective lens and a desired position is electrically detected according to the restart. The optical disk apparatus according to claim 1, further comprising a compensation circuit that compensates an error signal to control the operation of the objective lens.   The switch circuit transmits the differential amplification voltage to the adder circuit after the response time of the differential amplifier circuit has elapsed from the restart in response to the second timing signal, and the compensation circuit transmits the second timing signal The optical disk apparatus according to claim 2, wherein the objective lens is released after the response time has elapsed since the restart.   The controller detects a voltage value of the laser power control voltage during a period in which the emission of the laser beam is maintained, and calculates a voltage value of the DC bias voltage based on a gain of the addition circuit and the voltage value. The optical disc apparatus according to claim 1, wherein the bias voltage generating circuit is set.   The controller detects a voltage value of the differential amplification voltage during a period in which the emission of the laser beam is maintained, and controls the voltage value of the direct-current bias voltage so that the voltage value becomes zero. The optical disc apparatus according to claim 1, wherein the optical disc apparatus is set in a generation circuit. A difference in which a difference between a monitor voltage generated when the optical pickup detects the output power of the laser light emitted from the optical pickup and a reference voltage serving as a setting reference for the output power is amplified to generate a differential amplification voltage A dynamic amplification circuit;
An adding circuit for adding the differential amplification voltage and the DC bias voltage to generate a laser power control voltage for controlling the output power;
A bias voltage generation circuit for generating the DC bias voltage;
The supply of the differential amplification voltage to the addition circuit is interrupted during a period in which the emission of the laser light is temporarily interrupted, and the differential amplification voltage is transmitted to the addition circuit in response to the restart of the emission of the laser light. An optical pickup control device.

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