JP4432926B2 - Optical disk device - Google Patents

Description

  The present invention relates to an optical disk that performs offset measurement without affecting recording / playback performance while ensuring the stability of the focal position control of a light beam in an apparatus that performs at least one of recording and playback on an optical disk having an information surface. It relates to the device.

  The density of optical discs is increasing from CD to DVD and from DVD to Blu-ray. As the density increases, signal degradation due to focus shift and tracking shift due to offset of the servo system becomes more prominent. Therefore, a technique for removing and reducing the offset is required. Hereinafter, the operation of the conventional optical disk apparatus will be described with reference to FIGS. 9, 10, 11, and 12. FIG.

  FIG. 9 is a block diagram showing a configuration of offset correction for turning off the light beam in a conventional optical disc.

  The optical head 10 includes a light irradiation unit 11, a beam splitter 12, a condenser lens 13, a light receiving unit 14, and a focus actuator 15. The light irradiation unit 11 emits a light beam toward the optical disc 1 with a predetermined power. The irradiated light beam passes through the beam splitter 12 and is converged on the information surface of the optical disc 1 by the condenser lens 13. The light beam reflected by the optical disc 1 is reflected by the beam splitter 12 and applied to the light receiving unit 14. The light receiving unit 14 outputs the amount of light of the received light beam as a signal. The condenser lens 13 is driven in a direction perpendicular to the optical disc 1 by the focus actuator 15. The focus error signal generation unit 20 generates and outputs a focus error signal based on the signal from the light receiving unit 14. The focus filter 21 generates and outputs a focus control signal for driving the focus actuator 15 based on a signal from the focus error signal generation unit 20.

  The offset correction execution command unit 22 outputs a timing signal for executing offset correction at predetermined time intervals. The offset detection unit 23 outputs an offset detection execution signal based on the timing signal from the offset correction execution command unit 22.

  When the laser control unit 25 receives the offset detection execution signal from the offset detection unit 23, the laser control unit 25 puts the light beam emitted from the light irradiation unit 11 into a quenching state. When the servo hold command unit 24 receives the offset detection execution signal from the offset detection unit 23, the servo hold command unit 24 outputs a servo hold command signal. When the focus filter 21 receives a servo hold command signal from the servo hold command unit 24, the focus filter 21 holds the servo.

  The offset detection unit 23 detects the offset amount generated in the circuit based on the signal from the focus error signal generation unit 20. The offset correction unit 26 subtracts the offset amount detected by the offset detection unit 23 from the signal from the focus error signal generation unit 20 to the focus filter 21.

  Next, the offset correction procedure will be described with reference to FIG.

  FIG. 10A shows a timing signal for executing offset correction of the offset correction execution command unit 22 with the horizontal axis as time and the vertical axis as signal level. FIG. 10B shows an offset detection execution signal of the offset detector 23 with the horizontal axis representing time and the vertical axis representing signal level. FIG. 10C shows a signal of the servo hold command unit 24 with the horizontal axis representing time and the vertical axis representing the servo hold state binary signal level. The H level indicates that the servo is being held, and the L level indicates that the servo is not being held. FIG. 10D shows a signal of the focus error signal generation unit 20 with the horizontal axis representing time and the vertical axis representing the error signal generation output signal level. FIG. 10E shows the irradiation output signal of the light irradiation unit 11 with the horizontal axis representing time and the vertical axis representing the light beam irradiation signal level. When the offset detection unit 23 receives a timing signal for executing offset correction from the offset correction execution command unit 22, the offset detection unit 23 outputs an offset detection execution signal and starts offset correction. In the offset correction operation, first, the servo hold command unit 24 holds the servo of the focus filter 21, the laser control unit 25 extinguishes the light beam, and the output of the focus error signal generation unit 20 in this state is output by the offset detection unit 23. taking measurement. As a result, the offset amount of the focus error signal generation unit 20 configured with an analog circuit can be detected. By subtracting the detected offset amount from the input of the focus filter 21, an offset caused by a change with time or a temperature change can be corrected.

  Next, FIG. 11 shows a block diagram of a configuration of offset correction executed according to the information storage amount of a buffer for storing information read from the conventional optical disc 1. The disk reading unit 31 reads data recorded on the optical disk based on a signal from the light receiving unit 14. The read information storage unit 32 stores information on the optical disk read by the disk reading unit 31 in a storage buffer. The offset correction execution command unit 22 outputs a timing signal for executing offset correction at predetermined time intervals. The offset correction operation control unit 30 generates a timing signal for starting offset correction only when the amount of information stored in the read information storage unit 32 is larger than a predetermined threshold based on the timing signal from the offset correction execution command unit 22. Output. The offset detection unit 23 outputs an offset detection execution signal based on the timing signal from the offset correction operation control unit 30.

  Next, the offset correction procedure will be described with reference to FIG.

  FIG. 12A shows signals of the read information storage unit 32 when the horizontal axis is time and the vertical axis is the buffer accumulation level. FIG. 12B shows a timing signal for executing offset correction of the offset correction execution command unit 22 with the horizontal axis as time and the vertical axis as signal level. FIG. 12C shows a timing signal for starting offset correction of the offset correction operation control unit 30 with the horizontal axis as time and the vertical axis as signal level. FIG. 12D shows an offset detection execution signal of the offset detector 23 with the horizontal axis representing time and the vertical axis representing signal level.

  The read information storage unit 32 stores information on the optical disk read by the disk reading unit 31 in a storage buffer. When the offset correction operation control unit 30 receives a timing signal for executing offset correction from the offset correction execution command unit 22, the offset correction operation control unit 30 compares the information storage amount stored in the read information storage unit 32 with a predetermined threshold value. When the accumulated information amount is smaller than the predetermined threshold, a timing signal for starting offset correction is not output. When the accumulated information amount is larger than the predetermined threshold value, a timing signal for starting offset correction is output.

As the predetermined threshold, a value corresponding to the time required for offset correction is set. That is, the time required for reproducing the information stored in the read information storage unit 32 is compared with the time required for offset correction, and if the information storage for the time required for offset correction is ensured, the offset correction is performed. If the amount of information accumulated for the time required for offset correction is not secured, offset correction is not performed. By doing so, it is possible to perform offset correction without interrupting reproduction.
Japanese Patent No. 3426146 Japanese Patent No. 2910350

  However, in the configuration as described above, when the offset correction for turning off the light beam is performed during the reproducing operation or the recording operation, the reproducing operation or the recording operation is temporarily stopped to make the light beam extinguished. . As a result, there has been a problem that the transfer rate of reproduction or recording of the optical disc apparatus is lowered.

  In addition, when the execution of offset correction is determined according to the amount of information stored in the buffer that stores read information on the optical disk, offset correction depending on the reproduction transfer rate or the buffer capacity is performed. As a result, for example, in the case of an optical disk device with a low reproduction transfer rate, there is a problem that the control position of the focal position of the light beam shifts because the frequency of offset correction decreases. There was a problem that a buffer having the above capacity had to be installed.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an optical disc apparatus that performs offset measurement independent of recording / reproducing performance while ensuring the stability of the focal position control of the light beam. .

  An optical disc apparatus according to claim 1 of the present invention is an optical disc apparatus that performs at least one of recording and reproduction with respect to an optical disc having an information surface, and irradiating means for irradiating a light beam, and light irradiated by the irradiating means. Converging means for converging the beam on the optical disk, light receiving means for receiving reflected light from the optical disk and outputting an electrical signal corresponding to the amount of light received, and input for outputting either a signal from the light receiving means or a reference voltage signal Servo error signal generating means for generating at least one of a focus error signal corresponding to a defocus of a light beam on an optical disk and a tracking error signal corresponding to a track shift from a signal from a switching means and an input switching means And a signal for controlling the focal position of the light beam according to the signal from the servo error signal generation means Servo filter means to be generated, servo hold means for holding the operation of the servo filter means, servo settling state determination means for determining whether the focal position control of the light beam is in a settling state, and a timing signal for starting detection of the offset And a detection start command means for outputting a timing signal for starting offset detection when the determination result of the servo settling state determination means is in a settling state based on the timing signal from the detection operation command means Then, based on the timing signal from the detection start command means, the servo signal of the servo filter means is held by the servo hold means in the light beam irradiation state and switched so that the reference voltage signal is output from the input switching means to generate a servo error signal Offset detection to detect offset from means signal Characterized by comprising a stage.

  Further, in the optical disc apparatus according to claim 2 of the present invention, the offset detecting means integrates the detected offsets every time the offset is detected based on the timing signal from the detection start command means, and the offset average for the number of detections designated in advance. A value is output as a detection offset.

  Further, in the optical disk apparatus according to claim 3 of the present invention, the detection start command means is based on the timing signal from the detection operation command means, and when the determination result of the servo settling state determination means is in the non-settling state, the integrated value of the offset is obtained. An integration discard signal for discarding is output, and the offset detection unit discards the integrated value of the offset based on the integration cancellation signal from the detection start command unit.

  Further, in the optical disk apparatus according to claim 4 of the present invention, the detection start command means changes to the settling state when the determination result of the servo settling state determination means is the non-settling state based on the timing signal from the detection operation command means. The output of the timing signal for starting the offset detection until is delayed.

  Further, in the optical disk apparatus according to claim 5 of the present invention, the servo error signal generating means has a digital signal processor in the digital circuit, and generates a servo error signal by software processing that operates on the digital signal processor. To do.

  Further, in the optical disc apparatus according to claim 6 of the present invention, an offset correction signal is calculated based on the detected offset from the offset detecting means, and an offset correction value is obtained for the signal from the analog circuit to the digital circuit of the servo error signal generating means. And an offset correction means for applying.

  Further, in the optical disc apparatus according to claim 7 of the present invention, the offset correction means calculates the offset correction signal based on the detected offset from the offset detection means and applies the offset correction value to the input signal of the servo error signal generation means. It is characterized by comprising.

  Further, in the optical disk apparatus according to claim 8 of the present invention, the offset correction means that calculates the offset correction signal based on the detected offset from the offset detection means and applies the offset correction value to the input signal of the servo filter means. It is characterized by having.

  Furthermore, the optical disk apparatus according to claim 9 of the present invention further comprises circuit switching means for switching the circuit setting of the servo error signal generating means to reproduction circuit setting or recording circuit setting, and the offset detection means is a servo error signal by the circuit switching means. The circuit setting of the generating means is arbitrarily switched.

  Furthermore, in the optical disk apparatus according to claim 10 of the present invention, the servo settling state determining means determines that the black dot passing state is in a non-settling state.

  Further, in the optical disk apparatus according to claim 11 of the present invention, the servo settling state determining means determines that the state is in a non-settling state while the air bubble is passing.

  Further, in the optical disk apparatus according to claim 12 of the present invention, the servo settling state determining means determines that the portion where the address information of the optical disk is recorded is in the non-settling state while the focal point of the light beam passes. And

  Further, in the optical disc apparatus according to claim 13 of the present invention, the servo settling state determining means determines that the light beam focus control is in the non-settling state for a predetermined time after the focus control of the light beam is changed from the non-settling state to the settling state. Features.

  Further, in the optical disc apparatus according to claim 14 of the present invention, the servo settling state determining means predicts a timing when the focus control of the light beam becomes a non-settling state, and is in a non-settling state before a predetermined time from the predicted timing. It is characterized by determining.

  The optical disk apparatus according to claim 15 of the present invention further comprises focus pull-in means for searching for the focal position of the light beam at which the focus error signal is substantially zero, and the servo settling state determination means is in operation of the focus pull-in means. It is characterized by determining that it is a non-settling state.

  Furthermore, the optical disk apparatus according to claim 16 of the present invention further comprises tracking pull-in means for searching for the focal position of the light beam at which the tracking error signal becomes substantially zero, and the servo settling state determining means is in operation of the tracking pull-in means. It is characterized by determining that it is a non-settling state.

  The optical disc apparatus according to claim 17 of the present invention further comprises focus jump means for jumping between the layers of the optical disc, and the servo settling state judging means judges that it is in the non-settling state during the jump operation by the focus jump means. It is characterized by.

  Furthermore, the optical disk apparatus according to claim 18 of the present invention further comprises radial movement means for moving the focal point of the light beam in the radial direction of the optical disk, and the servo settling state determination means focuses the light beam by the radial movement means. While moving in the radial direction of the optical disk, it is determined to be in an unsettling state.

  Further, the optical disc apparatus according to claim 19 of the present invention comprises recording means for performing a recording operation on the optical disc, and the servo settling state determining means is in a non-settling state for a predetermined time after the start of the recording operation by the recording means. It is characterized by determining.

  Furthermore, the optical disk apparatus according to claim 20 of the present invention comprises recording means for performing a recording operation on the optical disk, and the servo settling state determining means is in a non-settling state for a predetermined time after the recording operation by the recording means is completed. It is characterized by determining.

  Furthermore, the optical disk apparatus according to claim 21 of the present invention further comprises recording state determining means for determining whether a track on the optical disk is in a recorded state or an unrecorded state, and the servo settling state determining means is determined by the recording state determining means. It is characterized in that it is determined to be in an unsettling state for a predetermined time after a change from unrecorded to recorded.

  The optical disk apparatus according to claim 22 of the present invention further comprises recording state determining means for determining whether a track on the optical disk is in a recorded state or an unrecorded state, and the servo settling state determining means is determined by the recording state determining means. It is characterized in that it is determined to be in an unsettling state for a predetermined time after the change from recorded to unrecorded.

  Further, in the optical disc apparatus according to claim 23 of the present invention, when the offset detection is not executed even after a predetermined time has elapsed since the offset detection by the offset detection means executed immediately before, the timing signal from the detection start command means is concerned. Forcibly executing means for outputting a timing signal for immediately starting offset detection.

  Furthermore, in the optical disc apparatus according to claim 24 of the present invention, the temperature detection means for detecting the temperature inside the optical disc apparatus, and the offset detection means executed immediately before based on the temperature from the temperature detection means exceeds a predetermined amount. When the offset detection is not performed even if the temperature changes, the forced execution means for outputting a timing signal for immediately starting the offset detection irrespective of the timing signal from the detection start command means is provided. And

  Further, in the optical disk apparatus according to claim 25 of the present invention, when the offset detection is not executed even after a predetermined time has elapsed since the offset detection by the offset detection means executed immediately before, the timing signal from the detection start command means is concerned. And forcibly executing means for outputting a timing signal for starting offset detection based on the timing signal from the detection operation command means.

  Furthermore, in the optical disk apparatus according to claim 26 of the present invention, a temperature detection means for detecting the temperature inside the optical disk apparatus and an offset detection by the offset detection means executed immediately before based on the temperature from the temperature detection means exceeds a predetermined amount. If offset detection is not performed even if the temperature changes, forced execution that outputs a timing signal for starting offset detection based on the timing signal from the detection operation command means regardless of the timing signal from the detection start command means Means.

  Further, in the optical disc apparatus according to claim 27 of the present invention, the forcible execution means outputs a gain switching command when the offset detection by the offset detection means is completed, and the gain is set for a predetermined amount based on the gain switching command from the forcible execution means. It is characterized by comprising gain switching means for switching high.

  An optical disk apparatus according to claim 28 of the present invention is an optical disk apparatus that performs at least one of recording and reproduction with respect to an optical disk having an information surface, and is irradiated with a light beam and irradiated by the irradiation means. A converging means for converging the light beam on the optical disk, a light receiving means for receiving the reflected light from the optical disk and outputting an electric signal corresponding to the amount of light received, and outputting either a signal from the light receiving means or a reference voltage signal From the analog circuit, at least one of a focus error signal corresponding to the defocus of the light beam on the optical disk and a tracking error signal corresponding to the track shift is generated from the input switching means and the signal from the input switching means Servo error signal generating means and a light beam according to the signal from the servo error signal generating means Servo filter means for generating a signal for controlling the focus position, servo hold means for holding the operation of the servo filter means, servo settling state determination means for determining whether the focus position control of the light beam is settling, and offset A detection operation command means for outputting a timing signal for starting detection, and a timing signal for starting offset detection when the determination result of the servo settling state determination means is in a settling state based on the timing signal from the detection operation command means The detection start command means for outputting the signal and the servo signal of the servo filter means by the servo hold means in the light beam irradiation state based on the timing signal from the detection start command means so that the reference voltage signal is output from the input switching means. Switch to the servo error signal generating means Characterized by comprising an offset detecting means for detecting.

  An optical disc apparatus according to claim 1 of the present invention is an optical disc apparatus that performs at least one of recording and reproduction with respect to an optical disc having an information surface, and irradiating means for irradiating a light beam, and light irradiated by the irradiating means. Converging means for converging the beam on the optical disk, light receiving means for receiving reflected light from the optical disk and outputting an electrical signal corresponding to the amount of light received, and input for outputting either a signal from the light receiving means or a reference voltage signal Servo error signal generating means for generating at least one of a focus error signal corresponding to a defocus of a light beam on an optical disk and a tracking error signal corresponding to a track shift from a signal from a switching means and an input switching means And a signal for controlling the focal position of the light beam according to the signal from the servo error signal generation means Servo filter means to be generated, servo hold means for holding the operation of the servo filter means, servo settling state determination means for determining whether the focal position control of the light beam is in a settling state, and a timing signal for starting detection of the offset And a detection start command means for outputting a timing signal for starting offset detection when the determination result of the servo settling state determination means is in a settling state based on the timing signal from the detection operation command means Then, based on the timing signal from the detection start command means, the servo signal of the servo filter means is held by the servo hold means in the light beam irradiation state and switched so that the reference voltage signal is output from the input switching means to generate a servo error signal Offset detection to detect offset from means signal Since a stage, independently of the recording and reproducing performance, it is possible to measure the offset while ensuring control stability.

  Further, in the optical disc apparatus according to claim 2 of the present invention, the offset detecting means integrates the detected offsets every time the offset is detected based on the timing signal from the detection start command means, and the offset average for the number of detections designated in advance. Since the value is output as a detection offset, the accuracy of offset measurement can be improved.

  Further, in the optical disk apparatus according to claim 3 of the present invention, the detection start command means is based on the timing signal from the detection operation command means, and when the determination result of the servo settling state determination means is in the non-settling state, the integrated value of the offset is obtained. An integration cancellation signal for discarding is output, and the offset detection unit discards the integrated value of the offset based on the integration cancellation signal from the detection start command unit, so that an uncertain offset measurement value can be discarded.

  Further, in the optical disk apparatus according to claim 4 of the present invention, the detection start command means changes to the settling state when the determination result of the servo settling state determination means is the non-settling state based on the timing signal from the detection operation command means. Since the output of the timing signal for starting the offset detection is delayed until the offset detection execution time can be secured.

  Furthermore, in the optical disk apparatus according to claim 5 of the present invention, the servo error signal generating means has a digital signal processor in the digital circuit, and generates a servo error signal by software processing that operates on the digital signal processor. Can generate a flexible error signal.

  Further, in the optical disc apparatus according to claim 6 of the present invention, an offset correction signal is calculated based on the detected offset from the offset detecting means, and an offset correction value is obtained for the signal from the analog circuit to the digital circuit of the servo error signal generating means. Since the offset correction means for applying is provided, the offset can be corrected at an arbitrary location inside the error signal generation circuit.

  Further, in the optical disc apparatus according to claim 7 of the present invention, the offset correction means calculates the offset correction signal based on the detected offset from the offset detection means and applies the offset correction value to the input signal of the servo error signal generation means. Therefore, the offset can be corrected immediately before the error generation circuit.

  Further, in the optical disk apparatus according to claim 8 of the present invention, the offset correction means that calculates the offset correction signal based on the detected offset from the offset detection means and applies the offset correction value to the input signal of the servo filter means. Since it is provided, the offset can be corrected immediately before the servo filter.

  Furthermore, the optical disk apparatus according to claim 9 of the present invention further comprises circuit switching means for switching the circuit setting of the servo error signal generating means to reproduction circuit setting or recording circuit setting, and the offset detection means is a servo error signal by the circuit switching means. Since the circuit setting of the generation means is arbitrarily switched, the offset of at least one of the reproduction circuit and the recording circuit can be measured regardless of the state during recording or reproduction.

  Further, in the optical disk apparatus according to claim 10 of the present invention, the servo settling state determining means determines that the black dot is in the non-settling state while passing through the black dot, so that an offset ensuring control stability is measured in the optical disk having black dots. it can.

  Furthermore, in the optical disk apparatus according to the eleventh aspect of the present invention, the servo settling state determining means determines that it is in the non-settling state while the air bubble is passing, so that it is possible to measure an offset that ensures control stability in the optical disk having the air bubble.

  Further, in the optical disk apparatus according to claim 12 of the present invention, the servo settling state determining means determines that the portion of the optical disk where the address information is recorded is in the non-settling state while the focal point of the light beam is passing. It is possible to measure an offset ensuring control stability in an optical disc having an information recording unit.

  Further, in the optical disc apparatus according to claim 13 of the present invention, the servo settling state determining means determines that the predetermined time is in the non-settling state after the focus control of the light beam has changed from the non-settling state to the settling state. Control stability after holding the servo can be ensured.

  Further, in the optical disc apparatus according to claim 14 of the present invention, the servo settling state determining means predicts a timing when the focus control of the light beam becomes a non-settling state, and is in a non-settling state before a predetermined time from the predicted timing. Since the determination is made, the control stability after the servo is held can be ensured.

  The optical disk apparatus according to claim 15 of the present invention further comprises focus pull-in means for searching for the focal position of the light beam at which the focus error signal is substantially zero, and the servo settling state determination means is in operation of the focus pull-in means. Since it is determined that the state is not settled, the offset can be measured without degrading the stability of the focus pull-in operation.

  Furthermore, the optical disk apparatus according to claim 16 of the present invention further comprises tracking pull-in means for searching for the focal position of the light beam at which the tracking error signal becomes substantially zero, and the servo settling state determining means is in operation of the tracking pull-in means. Since it is determined that the state is not settled, the offset can be measured without degrading the stability of the tracking pull-in operation.

  The optical disc apparatus according to claim 17 of the present invention further comprises focus jump means for jumping between the layers of the optical disc, and the servo settling state judging means judges that it is in the non-settling state during the jump operation by the focus jump means. The offset can be measured without degrading the stability of the interlayer jump operation in the optical disc having a plurality of information surfaces.

  Furthermore, the optical disk apparatus according to claim 18 of the present invention further comprises radial movement means for moving the focal point of the light beam in the radial direction of the optical disk, and the servo settling state determination means focuses the light beam by the radial movement means. Since it is determined that the state is not settled during movement in the optical disc radial direction, the offset can be measured without degrading the stability of the seek operation.

  Further, the optical disc apparatus according to claim 19 of the present invention comprises recording means for performing a recording operation on the optical disc, and the servo settling state determining means is in a non-settling state for a predetermined time after the start of the recording operation by the recording means. Therefore, the control stability after holding the servo can be ensured.

  Furthermore, the optical disk apparatus according to claim 20 of the present invention comprises recording means for performing a recording operation on the optical disk, and the servo settling state determining means is in a non-settling state for a predetermined time after the recording operation by the recording means is completed. Therefore, the control stability after holding the servo can be ensured.

  Furthermore, the optical disk apparatus according to claim 21 of the present invention further comprises recording state determining means for determining whether a track on the optical disk is in a recorded state or an unrecorded state, and the servo settling state determining means is determined by the recording state determining means. Since it is determined that the state is not settled for a predetermined time after the change from unrecorded to recorded, control stability after holding the servo can be ensured.

  The optical disk apparatus according to claim 22 of the present invention further comprises recording state determining means for determining whether a track on the optical disk is in a recorded state or an unrecorded state, and the servo settling state determining means is determined by the recording state determining means. Since it is determined that the state is not settled for a predetermined time after the change from recorded to unrecorded, it is possible to ensure control stability after the servo is held.

  Further, in the optical disc apparatus according to claim 23 of the present invention, when the offset detection is not executed even after a predetermined time has elapsed since the offset detection by the offset detection means executed immediately before, the timing signal from the detection start command means is concerned. The forced execution means for outputting the timing signal for starting the offset detection immediately is provided, so that the offset generated over time can be measured even when the settling state determination result frequently becomes a non-settling state. .

  Furthermore, in the optical disc apparatus according to claim 24 of the present invention, the temperature detection means for detecting the temperature inside the optical disc apparatus, and the offset detection means executed immediately before based on the temperature from the temperature detection means exceeds a predetermined amount. If the offset detection is not executed even if the temperature changes, the forced execution means that immediately outputs the timing signal for starting the offset detection regardless of the timing signal from the detection start command means is provided. Even when the state determination result frequently becomes an unsettling state, it is possible to measure an offset caused by a temperature change.

  Further, in the optical disk apparatus according to claim 25 of the present invention, when the offset detection is not executed even after a predetermined time has elapsed since the offset detection by the offset detection means executed immediately before, the timing signal from the detection start command means is concerned. The forced execution means for outputting the timing signal for starting the offset detection based on the timing signal from the detection operation command means is provided, so even if the settling state determination result frequently becomes a non-settling state, the time The offset generated over time can be measured.

  Furthermore, in the optical disk apparatus according to claim 26 of the present invention, a temperature detection means for detecting the temperature inside the optical disk apparatus and an offset detection by the offset detection means executed immediately before based on the temperature from the temperature detection means exceeds a predetermined amount. If offset detection is not performed even if the temperature changes, forced execution that outputs a timing signal for starting offset detection based on the timing signal from the detection operation command means regardless of the timing signal from the detection start command means The offset generated by the temperature change can be measured even when the settling state determination result frequently becomes a non-settling state.

  Further, in the optical disc apparatus according to claim 27 of the present invention, the forcible execution means outputs a gain switching command when the offset detection by the offset detection means is completed, and the gain is set for a predetermined amount based on the gain switching command from the forcible execution means. Since the gain switching means for switching to a high level is provided, control stability can be ensured even when offset measurement is performed in a non-settling state.

  The optical disk apparatus according to claim 28 of the present invention is an optical disk apparatus that performs at least one of recording and reproduction with respect to an optical disk having an information surface, the irradiation means for irradiating a light beam, and the irradiation means for irradiation. A converging means for converging the light beam on the optical disk, a light receiving means for receiving the reflected light from the optical disk and outputting an electric signal corresponding to the amount of light received, and outputting either a signal from the light receiving means or a reference voltage signal From the analog circuit, at least one of a focus error signal corresponding to the defocus of the light beam on the optical disk and a tracking error signal corresponding to the track shift is generated from the input switching means and the signal from the input switching means Depending on the signal from the servo error signal generating means and the servo error signal generating means, Servo filter means for generating a signal for controlling the focal position of the laser, servo hold means for holding the operation of the servo filter means, servo settling state judging means for judging whether the focus position control of the light beam is settling, and offset Detection operation command means for outputting a timing signal for starting detection, and timing for starting offset detection when the determination result of the servo settling state determination means is set based on the timing signal from the detection operation command means The detection start command means for outputting a signal, and the servo signal of the servo filter means is held by the servo hold means in the light beam irradiation state based on the timing signal from the detection start command means, and the reference voltage signal is output from the input switching means. The servo error signal generation means Since a offset detecting means for detecting the bets, regardless of the recording and reproducing performance, it is possible to measure the offset while ensuring control stability.

  Embodiments of the present invention will be described below.

(Embodiment 1)
A first embodiment will be described with reference to FIGS.

  FIG. 1 is a block diagram of an optical disc apparatus showing the configuration of the present embodiment. In FIG. 1, an optical disk 1, an optical head 10, a light irradiation unit 11, a beam splitter 12, a condenser lens 13, a light receiving unit 14, a focus actuator 15, a focus error signal generation unit 20, a focus filter 21, an offset correction execution command unit 22, The offset correction unit 26 and the servo hold command unit 24 have functions equivalent to those of the optical disk device of the background art, and detailed description thereof is omitted.

  The difference from the background art is that a black dot detection unit 40, a settling state determination unit 41, an offset correction operation control unit 42, an offset detection unit 43, a reference voltage generation unit 44, an input signal switch command unit 45, and an input signal switch 46 are provided. By using it, it is possible to perform offset correction independent of recording / reproducing performance while ensuring control stability. The function will be described below.

  In the present embodiment, the irradiation unit is the light irradiation unit 11. The converging means is the condenser lens 13. The light receiving means is the light receiving unit 14. The input switching means is an input signal switching switch 46, a reference voltage generating unit 44, and an input signal switching command unit 45. The servo error signal generation means is a focus error signal generation unit 20. The servo filter means is a focus filter 21. The servo hold means is a servo hold command unit 24. The servo settling state determination means is a settling state determination unit 41 and a black dot detection unit 40. The offset detection means is an offset detection unit 43. The offset correction means is the offset correction unit 26. The detection start command means is an offset correction operation control unit 42. The detection operation command means is an offset correction execution command unit 22.

  The black dot detection unit 40 in FIG. 1 detects the presence of black dots on the surface of the optical disk when the signal level from the light receiving unit 14 becomes smaller than a certain level. The settling state determination unit 41 determines that the focus control is in a non-settling state while the black dot detection unit 40 detects a black dot, and the focus control is in a settling state while no black dot is detected. Is determined. The settling state determination unit 41 further determines that the black dot detection unit 40 has been in a non-settling state for a predetermined time after the black dot detection unit 40 has changed from a state where black dots are detected to a state where black dots are not detected. The offset correction execution command unit 22 outputs a timing signal for executing offset correction at predetermined time intervals.

  The offset correction operation control unit 42 outputs a timing signal for starting offset correction if the determination result of the settling state determination unit 41 is in a set state based on the timing signal from the offset correction execution command unit 22, and determines the settling state. If the determination result of the unit 41 is the non-settling state, the output of the timing signal for starting the offset correction is delayed until the determination result becomes the settling state.

  The offset detection unit 43 outputs an offset detection execution signal for executing offset correction based on the timing signal from the offset correction operation control unit 42. The reference voltage generation unit 44 generates a reference voltage for the circuit.

  When the input signal switching command unit 45 receives the offset detection execution signal from the offset detection unit 43, the input signal switching command unit 45 outputs an input mute command signal to the input signal switch 46.

  The input signal switch 46 outputs a signal from the light receiver 14 or a signal from the reference voltage generator 44 based on a signal from the input signal switch command unit 45 and receives an input mute command signal from the input signal switch command unit 45. And a signal from the reference voltage generator 44 is output.

  The focus error signal generation unit 20 is composed of an analog circuit, and generates a focus error signal based on a signal from the input signal changeover switch 46.

  When the servo hold command unit 24 receives the offset detection execution signal from the offset detection unit 43, the servo hold command unit 24 outputs a servo hold command signal.

  The focus filter 21 generates a focus drive signal for controlling the focal position of the light beam on the information surface of the optical disc 1 based on the signal from the focus error signal generation unit 20 and controls the focus actuator 15. The focus filter 21 holds the servo when receiving the servo hold command signal from the servo hold command unit 24.

  The offset detection unit 43 detects the offset amount generated in the circuit based on the signal from the focus error signal generation unit 20, and stops outputting the offset detection execution signal when the offset detection is completed. The offset correction unit 26 subtracts the offset amount obtained from the offset detection unit 43 from the input of the focus filter 21.

  Next, the offset correction operation will be described in detail with reference to the waveform diagram of FIG.

  FIG. 2A is a signal of the black dot detection unit 40 in which the horizontal axis is time and the vertical axis is the black dot detection result binary signal level. In the case of level, a black dot undetected state is indicated.

  FIG. 2B is a signal of the settling state determination unit 41 in which the horizontal axis represents time and the vertical axis represents the settling state determination result binary signal level. In the case of the H level, the settling state is indicated. The case indicates a non-settling state.

  FIG. 2C shows a timing signal for executing offset correction of the offset correction execution command unit 22 with the horizontal axis as time and the vertical axis as signal level.

  FIG. 2D shows a timing signal for starting offset correction of the offset correction operation control unit 42 with the horizontal axis as time and the vertical axis as signal level.

  FIG. 2 (e) is a signal of the servo hold command unit 24 in which the horizontal axis represents time and the vertical axis represents the servo hold state binary signal level. The case indicates that the servo is not held.

  FIG. 2F shows a signal of the focus error signal generation unit 20 with the horizontal axis representing time and the vertical axis representing the error signal generation output signal level.

  FIG. 2G shows the irradiation output signal of the light irradiation unit 11 with the horizontal axis representing time and the vertical axis representing the light beam irradiation signal level.

  When the light beam passes through the black dots on the optical disk, the black dot detection unit 40 detects the black dots and enters a black dot detection state. When the black dot detection state is set, the settling state determination result becomes a non-settling state. During the non-settling state, even if a timing signal for executing offset correction is output from the offset correction execution command unit 22, the offset correction operation control unit 42 does not output a timing signal for starting offset correction and settles. The output of the timing signal for starting offset correction is delayed until the state determination result changes to the settling state.

  When the light beam finishes passing through the black dots on the optical disk, the signal of the black dot detection unit 40 changes from the black dot detection state to the black dot non-detection state. The settling state determination unit 41 continues to output the non-settling state for a predetermined time after the black dot detection state changes to the black dot non-detection state. When the settling state determination result becomes a settling state after a predetermined time, the offset correction operation control unit 42 outputs a timing signal for starting offset correction whose output has been delayed, and offset correction is started.

  In the offset correction operation, the focus filter 21 is held in the light beam emission state, the input of the focus error signal generation unit 20 is switched from the light receiving unit output to the reference voltage, and the output of the focus error signal generation unit 20 is offset detected in that state. By measuring by the unit 43, the offset amount with respect to the reference voltage of the focus error signal generation unit 20 configured by an analog circuit can be detected.

  By subtracting the detected offset amount from the input of the focus filter 21, an offset caused by a change with time or a temperature change can be corrected.

  As described above, when focus control is in a steady state, offset correction is performed with the light beam applied, and offset detection is not performed during the black dot passage and for a predetermined time after the black dot passage, thereby recording or reproducing operation. It is possible to correct an offset generated in a focus error signal generation circuit configured by an analog circuit due to a change over time or a temperature change while ensuring control stability without stopping the operation.

  In the present embodiment, it is determined that the control is in an unsettling state when black dots are detected, but it may be determined that the control is in an unsettling state when air bubbles are detected.

  In this embodiment, it is determined that the control is in an unsettling state when black dots are detected, but it may be determined that the control is in an unsettling state when fingerprints are detected.

  In this embodiment, it is determined that the control is in an unsettling state when black dots are detected. However, it may be determined that the control is in an unsettling state when scratches are detected.

  In the present embodiment, the circuit setting of the focus error signal generation circuit is not operated, but the recording circuit setting is switched during the reproducing operation and offset correction is performed, or the reproducing circuit setting is switched during the recording operation. In addition, the error signal generation circuit may be switched.

  In the present embodiment, offset correction is performed on the input signal of the focus filter 21, but offset correction may be performed on the input signal of the focus error signal generation circuit.

  Further, in this embodiment, the offset correction of the focus error signal generation circuit is performed, but the offset correction target circuit may be a tracking error signal generation circuit.

  In this embodiment, a timing signal for executing offset correction at a predetermined time interval is output. However, an output at a predetermined temperature interval or an output only once may be used.

(Embodiment 2)
A second embodiment will be described with reference to FIGS.

  FIG. 3 is a block diagram showing the configuration of the present embodiment. In FIG. 3, the optical disk 1, the optical head 10, the light irradiation unit 11, the beam splitter 12, the condensing lens 13, the light receiving unit 14, the focus actuator 15, the focus filter 21, the servo hold command unit 24, the reference voltage generation unit 44, and the input signal. The switching command unit 45, the input signal changeover switch 46, the offset correction execution command unit 22, and the offset correction unit 26 have functions equivalent to those of the optical disk device of the background art and the first embodiment, and detailed description thereof is omitted.

  The difference from the background art and the first embodiment is a focus error signal generation analog unit 50, a focus error signal generation digital unit 51, a CAPA detection unit 52, an offset detection unit 53, an offset correction operation control unit 54, and a settling state determination unit 55. By using, offset correction independent of recording / reproducing performance can be performed while ensuring control stability even when the address information on the disc passes through the recorded portion. The function will be described below.

  In the present embodiment, the irradiation unit is the light irradiation unit 11. The converging means is the condenser lens 13. The light receiving means is the light receiving unit 14. The input switching means is an input signal switching switch 46, a reference voltage generating unit 44, and an input signal switching command unit 45. The servo error signal generation means is a focus error signal generation analog unit 50 and a focus error signal generation digital unit 51. The servo filter means is a focus filter 21. The servo hold means is a servo hold command unit 24. The servo settling state determination means is a settling state determination unit 55 and a CAPA detection unit 52. The offset detection means is an offset detection unit 53. The offset correction means is the offset correction unit 26. The detection start command means is an offset correction operation control unit 54. The detection operation command means is an offset correction execution command unit 22.

  The CAPA detection unit 52 in FIG. 3 detects a portion where address information is recorded on the optical disc based on a signal from the light receiving unit 14. The settling state determination unit 55 determines that the focus control is in a non-settling state while the CAPA detection unit 52 detects the address information recording unit, and sets the focus control while the address information recording unit is not detected. It is determined that the state is present. The settling state determination unit 55 further predicts the timing at which the address information recording unit on the optical disk appears, and determines that it is in a non-settling state from a predetermined time before the predicted address information recording unit appearance timing. The offset correction execution command unit 22 outputs a timing signal for executing offset correction at predetermined time intervals.

  The offset correction operation control unit 54 outputs a timing signal for starting offset correction if the determination result of the settling state determination unit 55 is in the set state based on the timing signal from the offset correction execution command unit 22, and determines the settling state. If the determination result of the unit 55 is in an unsettling state, a timing signal for starting offset correction is not output.

  The offset detection unit 53 outputs an offset detection execution signal for executing offset correction based on the timing signal from the offset correction operation control unit 54.

  The reference voltage generation unit 44 generates a reference voltage for the circuit. When the input signal switching command unit 45 receives the offset detection execution signal from the offset detection unit 53, the input signal switching command unit 45 outputs an input mute command signal to the input signal switch 46.

  The input signal switch 46 outputs a signal from the light receiver 14 or a signal from the reference voltage generator 44 based on a signal from the input signal switch command unit 45 and receives an input mute command signal from the input signal switch command unit 45. And a signal from the reference voltage generator 44 is output.

  The focus error signal generation analog unit 50 includes an analog circuit. The focus error signal generation digital unit 51 is composed of a digital circuit. The focus error signal is generated from the focus error signal generation analog unit 50 and the focus error signal generation digital unit 51 based on the signal from the input signal changeover switch 46.

  When the servo hold command unit 24 receives the offset detection execution signal from the offset detection unit 53, the servo hold command unit 24 outputs a servo hold command signal. The focus filter 21 generates a focus drive signal for controlling the focal position of the light beam on the information surface of the optical disc 1 based on the signal from the focus error signal generation digital unit 51 and controls the focus actuator 15. The focus filter 21 holds the servo when receiving the servo hold command signal from the servo hold command unit 24.

  The offset detection unit 53 detects the offset amount generated in the circuit based on the signal from the focus error signal generation analog unit 50, and stops outputting the offset detection execution signal when the detection of the offset is completed. The offset detector 53 further integrates the detected offsets a plurality of times, and obtains an average value of the offset amounts. The offset correction unit 26 subtracts the offset amount obtained from the offset detection unit 53 from the signal from the focus error signal generation analog unit 50 to the focus error signal generation digital unit 51.

  Next, the offset correction operation will be described in detail with reference to the waveform diagram of FIG.

  FIG. 4A shows a signal of the CAPA detection unit 52 with the horizontal axis representing time and the vertical axis representing the binary signal level of the address information recording unit detection result. In the case of H level, the address information recording unit detection state is shown. In the case of L level, the address information recording part undetected state is indicated.

  FIG. 4B shows the value of the counter built in the settling state determination unit 55 for predicting the address information recording unit appearance timing, where the horizontal axis is time and the vertical axis is the counter value.

  FIG. 4C is a signal of the settling state determination unit 55 in which the horizontal axis represents time and the vertical axis represents the settling state determination result binary signal level. The case indicates a non-settling state.

  FIG. 4D shows a timing signal for executing offset correction of the offset correction execution command unit 22 with the horizontal axis as time and the vertical axis as signal level.

  FIG. 4E shows a timing signal for starting offset correction of the offset correction operation control unit 54 with the horizontal axis as time and the vertical axis as signal level.

  FIG. 4F shows an offset detection execution signal of the offset detection unit 53 with the horizontal axis representing time and the vertical axis representing signal level.

  FIG. 4G shows the offset integrated value of the offset detection unit 53 with the horizontal axis representing time and the vertical axis representing the offset integrated value. When the light beam passes through the portion where the address information is recorded on the optical disc, the CAPA detection unit 52 outputs the address information recording unit. While the address information recording unit is detected, the settling state determination result is determined to be a non-settling state. When the light beam finishes passing through the address information recording unit on the optical disc, the CAPA detection unit 52 changes from the state in which the address information recording unit is detected to the state in which the address information recording unit is not detected, and the settling state determination result Changes to a settling state. The settling state determination unit 55 predicts the next timing at which the address information recording unit appears by using a built-in subtraction counter. The operation of the built-in counter will be described below.

  When passing through the address information recording unit, the settling state determination unit 55 initializes the built-in counter value to a predetermined value. The settling state determination unit 55 continues to subtract the initialized built-in counter value until the next address information recording unit appears and finishes passing. When the built-in counter value becomes equal to or smaller than the predetermined threshold value, the settling state determination unit 55 predicts that the appearance timing of the address information recording unit is approaching, and outputs a non-settling state. During the non-settling state, even if a timing signal for executing offset correction is output from the offset correction execution command unit 22, the offset correction operation control unit 54 does not output a timing signal for starting offset correction.

  During the settling state, the offset correction operation control unit 54 outputs a timing signal for starting offset correction based on a timing signal for executing offset correction from the offset correction execution command unit 22. When the offset detection unit 53 receives a timing signal for starting offset correction from the offset correction operation control unit 54, the offset detection unit 53 outputs an offset detection execution signal and starts offset correction.

  In the offset correction operation, the focus filter 21 is held in a state where the light beam is irradiated, the input of the focus error signal generation analog unit 50 is switched from the light receiving unit output to the reference voltage, and the focus error signal generation analog unit 50 is in that state. Is measured by the offset detection unit 53, thereby detecting the offset amount with respect to the reference voltage of the focus error signal generation analog unit 50 constituted by an analog circuit, and integrating and holding the detected offset amount.

  The offset detection unit 53 integrates the detected offset amount a plurality of times, and then obtains an integrated average value of the offset amount. By subtracting the average value of the obtained offset amounts from the signal from the focus error signal generation analog unit 50 to the focus error signal generation digital unit 51, it is possible to correct an offset caused by a change with time or a temperature change.

  As described above, when the focus control is in the settling state, offset correction is performed while the light beam is irradiated, and offset detection is not performed for a predetermined time before and after passing through the address information recording unit on the optical disc. The offset generated in the analog circuit portion of the focus error signal generation circuit due to changes over time or temperature can be corrected while ensuring control stability without stopping the recording or reproducing operation.

  In this embodiment, the built-in subtraction counter is used to predict the appearance of the address information recording unit, but the built-in counter may be an addition counter.

  In this embodiment, it is determined that the control is in an unsettling state when the address information recording unit is detected, but it may be determined that the control is in an unsettling state when an air bubble is detected.

  In this embodiment, it is determined that the control is in an unsettling state when the address information recording unit is detected. However, it may be determined that the control is in an unsettling state when black dots are detected.

  In this embodiment, it is determined that the control is in an unsettling state when the address information recording unit is detected, but it may be determined that the control is in an unsettling state when the fingerprint is detected.

  In this embodiment, it is determined that the control is in an unsettling state when the address information recording unit is detected, but it may be determined that the control is in an unsettling state when a scratch is detected.

  In the present embodiment, the predetermined time before passing the address information recording unit and before detection of the address information recording unit is set to the non-settling state, but in combination with the process of setting the predetermined time after passing the address information recording unit to the non-settling state. Also good.

  In this embodiment, the focus error signal is generated from the analog circuit and the digital circuit. However, the focus error signal may be generated from software processing that operates on the digital signal processor in the analog circuit and the digital circuit.

  In the present embodiment, the circuit setting of the focus error signal generation circuit is not operated, but the recording circuit setting is switched during the reproducing operation and offset correction is performed, or the reproducing circuit setting is switched during the recording operation. In addition, the error signal generation circuit may be switched.

  In this embodiment, offset correction is performed on the signal from the analog unit to the digital unit of the focus error signal generation circuit. However, offset correction may be performed on the input signal of the focus signal generation analog circuit. .

  In this embodiment, offset correction is performed on the signal from the analog unit to the digital unit of the focus error signal generation circuit. However, offset correction may be performed on the input signal of the focus filter 21.

  Further, in this embodiment, the offset correction of the focus error signal generation circuit is performed, but the offset correction target circuit may be a tracking error signal generation circuit.

  In this embodiment, a timing signal for executing offset correction at a predetermined time interval is output. However, an output at a predetermined temperature interval or an output only once may be used.

(Embodiment 3)
A third embodiment will be described with reference to FIGS.

  FIG. 5 is a block diagram showing the configuration of the present embodiment. In FIG. 5, an optical disk 1, an optical head 10, a light irradiation unit 11, a beam splitter 12, a condenser lens 13, a light receiving unit 14, a focus actuator 15, a focus error signal generation unit 20, a focus filter 21, an offset correction execution command unit 22, The offset detection unit 53, the offset correction unit 26, the servo hold command unit 24, the reference voltage generation unit 44, the input signal switching command unit 45, and the input signal switch 46 are the optical disk device of the background art and the first and second embodiments. It is assumed that it has a function equivalent to that of No. 1, and detailed description is omitted.

  The difference from the background art and the first and second embodiments is that a focus pull-in execution command unit 60, a focus pull-in control unit 61, a focus drive output changeover switch 62, an offset correction operation control unit 63, and a settling state determination unit 64 are provided. By using it, it is possible to perform offset correction independent of recording / reproducing performance while ensuring control stability during the focus pull-in operation or immediately after the focus pull-in. The function will be described below.

  The irradiation means is the light irradiation unit 11. The converging means is the condenser lens 13. The light receiving means is the light receiving unit 14. The input switching means is an input signal switching switch 46, a reference voltage generating unit 44, and an input signal switching command unit 45. The servo error signal generation means is a focus error signal generation unit 20. The servo filter means is a focus filter 21. The servo hold means is a servo hold command unit 24. The servo settling state determination means is a settling state determination unit 64. The focus pull-in means is a focus pull-in execution command unit 60, a focus pull-in control unit 61, and a focus drive output changeover switch 62. The offset detection means is an offset detection unit 53. The offset correction means is the offset correction unit 26. The detection start command means is an offset correction operation control unit 63. The detection operation command means is an offset correction execution command unit 22.

  The focus pull-in execution command unit 60 in FIG. 1 outputs a timing signal for starting focus pull-in. The focus pull-in control unit 61 outputs a signal indicating a state in which focus pull-in is being executed based on the timing signal from the focus pull-in execution command unit 60. The focus pull-in control unit 61 further outputs a drive signal for searching for the focal position of the light beam at which the signal from the focus error signal generation unit 20 is substantially zero.

  The focus drive output changeover switch 62 outputs a drive signal from the focus pull-in control unit 61 to the focus actuator 15 when the signal from the focus pull-in control unit 61 indicates that the focus pull-in is being executed, and does not indicate that the focus pull-in is being executed. Outputs a drive signal from the focus filter 21 to the focus actuator 15. When the focus pull-in control unit 61 finds the focal position of the light beam at which the signal from the focus error signal generation unit 20 is substantially 0, the focus pull-in control unit 61 stops outputting a signal indicating that the focus pull-in is being performed.

  The settling state determination unit 64 determines that the focus pulling control unit 61 indicates that the focus pulling is being performed, and determines that the settling state is in the non-settling state. The settling state determination unit 64 further determines that the settling state determination unit 64 is in a non-settling state for a predetermined time after the signal from the focus pull-in control unit 61 changes from a state in which focus pull-in is being performed to a state in which focus pull-in is not being performed.

  The offset correction execution command unit 22 outputs an offset correction execution timing signal at predetermined time intervals. The offset correction operation control unit 63 outputs a timing signal for starting offset correction if the determination result of the settling state determination unit 64 is in a set state based on the timing signal from the offset correction execution command unit 22, and determines the settling state. If the determination result of the unit 64 is the non-settling state, the output of the timing signal for starting the offset correction is delayed until the determination result becomes the settling state. The offset correction operation control unit 63 further outputs a timing signal for discarding the offset integrated value if the determination result of the settling state determination unit 64 is based on the timing signal from the offset correction execution command unit 22 in the non-settling state.

  The offset detection unit 53 outputs an offset detection execution signal for executing offset correction based on the timing signal from the offset correction operation control unit 63.

  The reference voltage generation unit 44 generates a reference voltage for the circuit. When the input signal switching command unit 45 receives the offset detection execution signal from the offset detection unit 53, the input signal switching command unit 45 outputs an input mute command signal to the input signal switch 46.

  The input signal switch 46 outputs a signal from the light receiver 14 or a signal from the reference voltage generator 44 based on a signal from the input signal switch command unit 45 and receives an input mute command signal from the input signal switch command unit 45. And a signal from the reference voltage generator 44 is output.

  The focus error signal generation unit 20 is composed of an analog circuit, and generates a focus error signal based on a signal from the input signal changeover switch 46.

  When the servo hold command unit 24 receives the offset detection execution signal from the offset detection unit 53, the servo hold command unit 24 outputs a servo hold command signal.

  The focus filter 21 generates a focus drive signal for controlling the focal position of the light beam on the information surface of the optical disc 1 based on the signal from the focus error signal generation unit 20 and controls the focus actuator 15. The focus filter 21 holds the servo when receiving the servo hold command signal from the servo hold command unit 24.

  The offset detection unit 53 detects the offset amount generated in the circuit based on the signal from the focus error signal generation unit 20, and stops outputting the offset detection execution signal when the offset detection is completed. The offset detector 53 further integrates the detected offsets a plurality of times, and obtains an average value of the offset amounts. Further, when receiving the timing signal for discarding the offset integrated value from the offset correction operation control unit 63, the offset detecting unit 53 discards the offset integrated value.

  The offset correction unit 26 subtracts the offset amount obtained from the offset detection unit 53 from the input of the focus error signal generation unit 20.

  Next, the offset correction operation will be described in detail with reference to the waveform diagram of FIG.

  FIG. 6A shows a signal of the focus pull-in control unit 61 with the horizontal axis as time and the vertical axis as the focus pull-in execution state binary signal level. The level indicates that the focus is not being drawn.

  FIG. 6B is a signal of the settling state determination unit 64 in which the horizontal axis represents time and the vertical axis represents the settling state determination result binary signal level. In the case of H level, the settling state is indicated. The case indicates a non-settling state.

  FIG. 6C shows a timing signal for executing offset correction of the offset correction execution command unit 22 with the horizontal axis as time and the vertical axis as signal level.

  FIG. 6D shows a timing signal for starting offset correction of the offset correction operation control unit 63 with the horizontal axis as time and the vertical axis as signal level.

  FIG. 6E shows a timing signal for rejecting the integrated offset value of the offset correction operation control unit 63 with the horizontal axis as time and the vertical axis as signal level.

  FIG. 6F shows an offset detection execution signal of the offset detection unit 53 with the horizontal axis as time and the vertical axis as signal level.

  FIG. 6G shows the offset integrated value of the offset detector 53 with the horizontal axis representing time and the vertical axis representing the offset integrated value.

  When the focus pull-in control unit 61 receives a timing signal for starting focus pull-in from the focus pull-in execution command unit 60, the focus pull-in control unit 61 outputs a focus pull-in execution signal, and the signal from the focus error signal generation unit 20 becomes substantially zero. A focus drive signal for searching the focal position of the light beam is output.

  The settling state determination unit 64 determines that the settling state is a non-settling state when the signal from the focus pulling control unit 61 indicates that the focus pulling is being executed. During the non-settling state, even if a timing signal for executing offset correction is output from the offset correction execution command unit 22, the offset correction operation control unit 63 does not output a timing signal for starting offset correction, A timing signal for discarding the integrated offset value is output.

  When receiving the timing signal for discarding the offset integrated value from the offset correction operation control unit 63, the offset detecting unit 53 discards the offset integrated value accumulated so far. When the focus position of the light beam at which the signal from the focus error signal generation unit 20 is substantially 0 is found, the focus pull-in control unit 61 stops outputting the focus pull-in execution signal and completes the focus pull-in operation.

  The settling state determination unit 64 determines that the settling state is in a non-settling state for a predetermined time after the focus pull-in operation is completed. During the settling state, the offset correction operation control unit 63 outputs a timing signal for starting offset correction based on the timing signal for executing offset correction from the offset correction execution command unit 22. When the offset detection unit 53 receives a timing signal for starting offset correction from the offset correction operation control unit 63, the offset detection unit 53 outputs an offset detection execution signal and starts offset correction.

  In the offset correction operation, the focus filter 21 is held in a state where the light beam is irradiated, the input of the focus error signal generation unit 20 is switched from the light receiving unit output to the reference voltage, and the output of the focus error signal generation unit 20 in that state. Is measured by the offset detection unit 53, thereby detecting the offset amount with respect to the reference voltage of the focus error signal generation unit 20 constituted by an analog circuit, and integrating and holding the detected offset amount. The offset detection unit 53 integrates the detected offset amount a plurality of times, and then obtains an integrated average value of the offset amount.

  By subtracting the average value of the obtained offset amounts from the input signal of the focus error signal generation unit 20, it is possible to correct an offset caused by a change with time or a temperature change.

  As described above, when the focus control is in an unsteady state, offset correction is performed with the light beam irradiated, and recording or recording is not performed during the focus pull-in operation and for a predetermined time after the focus pull-in operation is completed. A circuit offset generated in a focus error signal generation circuit constituted by an analog circuit due to a change with time or a temperature change can be corrected while securing the stability of the focus pull-in operation without stopping the reproduction state.

  In this embodiment, the focus pull-in operation is set to the non-settling state, but the tracking pull-in operation may be set to the non-settling state.

  In the present embodiment, the focus pull-in operation is set to the non-settling state, but the interlayer jump operation in the optical disc 1 having a plurality of information surfaces may be set to the non-settling state.

  In the present embodiment, the focus pull-in operation is set to the non-settling state, but the movement operation in the radial direction with respect to the optical disc 1 may be set to the non-settling state.

  Further, in this embodiment, the non-settling state is set during the focus pull-in operation, but a predetermined time after the transition from the recording operation to the reproduction operation may be set in the non-settling state.

  Further, in this embodiment, the non-settling state is set during the focus pull-in operation, but a predetermined time after shifting from the reproduction operation to the recording operation may be set in the non-settling state.

  In the present embodiment, the non-settling state is set during the focus pull-in operation. However, a predetermined time after entering the unrecorded portion from the recorded portion in the track on the optical disc may be set in the non-settling state.

  Further, in the present embodiment, the non-settling state is set during the focus pull-in operation, but a predetermined time after entering the recorded portion from the unrecorded portion in the track on the optical disk may be set in the non-settling state.

  Further, in the present embodiment, the focus pulling operation is set to the non-settling state, but a predetermined time before the focus pulling operation may be set to the non-settling state.

  Further, in the present embodiment, the integrated value of the offset value detected in the non-settling state is discarded, but it may be retained without being discarded.

  In this embodiment, a timing signal for executing offset correction at a predetermined time interval is output. However, an output at a predetermined temperature interval or an output only once may be used.

(Embodiment 4)
A fourth embodiment will be described with reference to FIGS.

  FIG. 7 is a block diagram showing the configuration of the present embodiment. In FIG. 7, an optical disk 1, an optical head 10, a light irradiation unit 11, a beam splitter 12, a condenser lens 13, a light receiving unit 14, a focus actuator 15, a focus error signal generation unit 20, a focus filter 21, an offset correction execution command unit 22, The black dot detection unit 40, the offset correction operation control unit 42, the offset detection unit 43, the reference voltage generation unit 44, the input signal switch command unit 45, the input signal switch 46, the servo hold command unit 24, and the offset correction unit 26 are related to the background art. It is assumed that the optical disk apparatus has the same functions as those of the first and second embodiments and the third embodiment, and detailed description thereof is omitted.

  The difference from the background art, the first embodiment, the second embodiment, and the third embodiment is that the forced execution determination unit 70, the gain switching unit 71, and the settling state determination unit 72 are used to generate an offset greater than the allowable amount. This is where offset correction can be performed while ensuring control stability. The function will be described below.

  In the present embodiment, the irradiation unit is the light irradiation unit 11. The converging means is the condenser lens 13. The light receiving means is the light receiving unit 14. The input switching means is an input signal switching switch 46, a reference voltage generating unit 44, and an input signal switching command unit 45. The servo error signal generation means is a focus error signal generation unit 20. The servo filter means is a focus filter 21. The servo hold means is a servo hold command unit 24. The servo settling state determination means is a settling state determination unit 72 and a black dot detection unit 40. The offset detection means is an offset detection unit 43. The offset correction means is the offset correction unit 26. The detection start command means is an offset correction operation control unit 42 and a forced execution determination unit 70. The detection operation command means is an offset correction execution command unit 22. The gain switching means is a gain switching unit 71.

  The black dot detection unit 40 in FIG. 7 detects the presence of black dots on the surface of the optical disc when the signal level from the light receiving unit 14 becomes smaller than a certain level. The settling state determination unit 72 determines that the focus control is in a non-settling state while the black dot detection unit 40 detects a black dot, and the focus control is in a settling state while no black dot is detected. Is determined.

  The offset correction execution command unit 22 outputs a timing signal for executing offset correction at predetermined time intervals. Based on the timing signal from the offset correction execution command unit 22, the offset correction operation control unit 42 outputs a timing signal for starting offset correction if the determination result of the settling state determination unit 72 is in a set state.

  The forced execution determination unit 70 has a built-in addition counter that measures an elapsed time from the previous offset correction execution, and outputs a timing signal for starting offset correction based on the timing signal from the offset correction operation control unit 42. Then, the built-in addition counter value is cleared and measurement of elapsed time is started. The offset detection unit 43 outputs an offset detection execution signal for executing offset correction based on the timing signal from the forced execution determination unit 70. The reference voltage generation unit 44 generates a reference voltage for the circuit.

  When the input signal switching command unit 45 receives the offset detection execution signal from the offset detection unit 43, the input signal switching command unit 45 outputs an input mute command signal to the input signal switch 46. The input signal switch 46 outputs a signal from the light receiver 14 or a signal from the reference voltage generator 44 based on a signal from the input signal switch command unit 45 and receives an input mute command signal from the input signal switch command unit 45. And a signal from the reference voltage generator 44 is output.

  The focus error signal generation unit 20 is composed of an analog circuit, and generates a focus error signal based on a signal from the input signal changeover switch 46. When the servo hold command unit 24 receives the offset detection execution signal from the offset detection unit 43, the servo hold command unit 24 outputs a servo hold command signal.

  The focus filter 21 generates a focus drive signal for controlling the focal position of the light beam on the information surface of the optical disc 1 based on the signal from the focus error signal generation unit 20 and controls the focus actuator 15. The focus filter 21 holds the servo when receiving the servo hold command signal from the servo hold command unit 24.

  The offset detection unit 43 detects the offset amount generated in the circuit based on the signal from the focus error signal generation unit 20, and stops outputting the offset detection execution signal when the offset detection is completed. The offset correction unit 26 subtracts the offset amount obtained from the offset detection unit 43 from the input of the focus filter 21.

  When the built-in addition counter value exceeds a predetermined threshold value, the forced execution determination unit 70 forcibly outputs a timing signal for immediately starting offset correction regardless of the timing signal from the offset correction operation control unit 42. Output. The forced execution determination unit 70 further outputs a gain switching signal immediately after the offset detection execution signal from the offset detection unit 43 stops when the timing signal is output when the counter value is equal to or greater than a predetermined threshold.

  Based on the gain switching command from the forced execution determination unit 70, the gain switching unit 71 sets the gain for controlling the focal position of the light beam higher by a predetermined time.

  Next, the offset correction operation will be described in detail with reference to the waveform diagram of FIG.

  FIG. 8A shows a signal of the black dot detection unit 40 with the horizontal axis representing time and the vertical axis representing the black signal detection result binary signal level. In the case of level, a black dot undetected state is indicated.

  FIG. 8B is a signal of the settling state determination unit 72 in which the horizontal axis represents time and the vertical axis represents the settling state determination result binary signal level. In the case of H level, the settling state is indicated. The case indicates a non-settling state.

  FIG. 8C shows a timing signal for executing offset correction of the offset correction execution command unit 22 with the horizontal axis as time and the vertical axis as signal level.

  FIG. 8D shows a timing signal for starting offset correction of the forced execution determination unit 70 with the horizontal axis as time and the vertical axis as signal level.

  FIG. 8E shows the value of the addition counter built in the forced execution determination unit 70 for measuring the non-execution time of offset correction, where the horizontal axis is time and the vertical axis is the counter value.

  FIG. 8F shows an offset detection execution signal of the offset detector 43 with the horizontal axis representing time and the vertical axis representing signal level.

  FIG. 8G shows the gain value of the gain switching unit 71 with the horizontal axis representing time and the vertical axis representing gain value.

  When the light beam passes through the black dots on the optical disk, the black dot detection unit 40 detects the black dots and enters a black dot detection state. When the black dot detection state is set, the settling state determination result becomes a non-settling state. The forced execution determination unit 70 has a built-in addition counter that measures the elapsed time from the previous offset correction execution, and if the addition counter value is less than a predetermined threshold, a timing signal for starting offset correction during the non-settling state. If the addition counter value is equal to or greater than the predetermined threshold value, that is, if the offset correction is not executed even after the predetermined time has elapsed, the offset correction is started immediately even if the settling state determination result is the non-settling state. The timing signal is forcibly output. The forced execution determination unit 70 further outputs a gain switching command to the gain switching unit 71 immediately after the offset correction is completed when outputting a timing signal for starting offset correction in the non-settling state.

  The gain switching unit 71 sets a high gain for controlling the focal position of the light beam for a predetermined time based on the gain switching command. By doing so, it is possible to continue to suppress the control shift of the focal position of the light beam due to the offset generated over time while keeping the control stability within a predetermined range.

  In this embodiment, the offset correction is forcibly executed according to the elapsed time from the completion of the offset correction. However, the offset correction may be forcibly executed depending on the number of times that the offset correction is not continuously executed. .

  In this embodiment, offset correction is forcibly executed according to the elapsed time from completion of offset correction. However, offset correction may be forcibly executed depending on the temperature change amount from completion of offset correction.

  In this embodiment, when the offset correction is not executed even after a predetermined time has elapsed, the timing signal forcibly executing the offset correction is output based on the timing signal from the offset correction execution command unit 22, The offset correction may be forcibly executed immediately after the elapse of time.

  In the present embodiment, when the offset correction is not executed even after a predetermined time has elapsed, the timing signal forcibly executing the offset correction is output based on the timing signal from the offset correction execution command unit 22. The offset correction may be forcibly executed immediately when the fixed temperature changes.

  INDUSTRIAL APPLICABILITY The present invention is an apparatus that performs at least one of recording and reproduction with respect to an optical disk having an information surface, and is used for an optical disk apparatus that performs offset measurement independent of recording / reproduction performance while ensuring the stability of the focal position control of the light beam. Is possible. Particularly, it is suitable for an optical disc recorder or an optical disc player that records or reproduces digital video information continuously for a long time.

The figure which shows the block configuration in Embodiment 1. (A) In the first embodiment, the horizontal axis represents time and the vertical axis represents the black dot detection result binary signal level. This is a black dot detection unit signal. In the case of the level, a diagram showing a black dot non-detection state (b) is a signal of a settling state determination unit in which the horizontal axis in the first embodiment is time and the vertical axis is a settling state determination result binary signal level; FIG. 8C shows the settling state in the case of the level, and the non-settling state in the case of the L level. FIG. 7C shows the offset correction of the offset correction execution command unit with the horizontal axis as time and the vertical axis as the signal level in the first embodiment. FIG. 4D is a timing diagram for executing offset correction in the first embodiment, in which the horizontal axis is time and the vertical axis is the signal level. (E) shows a signal. In the first embodiment, the horizontal axis is time, the vertical axis is the servo hold state binary signal level, and the signal is in the servo hold command section. (F) shows the signal of the focus error signal generation unit in which the horizontal axis in the first embodiment is time and the vertical axis is the error signal generation output signal level. FIG. (G) is a diagram showing an irradiation output signal of the light irradiation unit with the horizontal axis as time and the vertical axis as the light beam irradiation signal level in the first embodiment. The figure which shows the block configuration in Embodiment 2. (A) CAPA detection unit signal in which the horizontal axis in the second embodiment is time and the vertical axis is the binary signal level of the address information recording unit detection result. In the case of H level, the address information recording unit detection state is In the case of L level, the address information recording unit undetected state is shown. (B) For predicting the address information recording unit appearance timing with the horizontal axis in time and the vertical axis in the second embodiment as a counter value. FIG. 8C shows the value of the counter built in the settling state determination unit (c) is a signal of the settling state determination unit with the horizontal axis in the second embodiment as time and the vertical axis as the settling state determination result binary signal level; FIG. 4D shows the settling state in the case of the H level, and the non-settling state in the case of the L level. FIG. 4D shows the offset of the offset correction execution command unit with the horizontal axis as time and the vertical axis as the signal level. Realize the correction (E) A timing signal for starting offset correction of the offset correction operation control unit with the horizontal axis as time and the vertical axis as signal level in Embodiment 2 (f) ) A diagram showing an offset detection execution signal of the offset detection unit with the horizontal axis as time and the vertical axis as signal level in the second embodiment. FIG. 9 shows a block configuration in Embodiment 3. (A) In the third embodiment, the horizontal axis indicates time, the vertical axis indicates the focus pull-in execution state binary signal level, and the signal of the focus pull-in control unit indicates that the focus pull-in is being executed. In the case of the level, FIG. 5 (b) showing that the focus pull-in is not being executed is a signal of the settling state determination unit in which the horizontal axis in the third embodiment is time and the vertical axis is the settling state determination result binary signal level. FIG. 8C shows the settling state in the case of the level, and the non-settling state in the case of the L level. FIG. 7C shows the offset correction of the offset correction execution command unit with the horizontal axis as time and the vertical axis as the signal level in the third embodiment. (D) Timing signal for starting offset correction of the offset correction operation control unit with the horizontal axis as time and the vertical axis as signal level in the third embodiment. FIG. 5E shows a timing signal for rejecting the integrated offset value of the offset correction operation control unit with the horizontal axis in time and the vertical axis in signal level in the third embodiment. FIG. 3 shows the offset detection execution signal of the offset detector with the horizontal axis in time as the time axis and the vertical axis as the signal level. (G) The horizontal axis in Embodiment 3 is the time, and the vertical axis is the offset integrated value. The figure which shows the offset integrated value of the offset detection part FIG. 9 shows a block configuration in Embodiment 4. (A) In the fourth embodiment, the horizontal axis represents time and the vertical axis represents the black dot detection result binary signal level. This is a black dot detection unit signal. In the case of level, a diagram showing a black dot non-detection state (b) is a signal of a settling state determination unit in which the horizontal axis in the fourth embodiment is time and the vertical axis is a settling state determination result binary signal level; FIG. 8C shows the settling state in the case of level, and the non-settling state in the case of L level. (C) Offset correction of the offset correction execution command unit in the fourth embodiment with the horizontal axis as time and the vertical axis as signal level. (D) shows a timing signal for starting offset correction of the forced execution determination unit with the horizontal axis as time and the vertical axis as the signal level in the fourth embodiment. FIG. 8E is a diagram showing the value of the counter built in the forced execution determination unit for measuring the non-execution time of offset correction, where the horizontal axis is time and the vertical axis is the counter value in the fourth embodiment. FIG. 5 (g) is a diagram showing an offset detection execution signal of the offset detection unit with time as the horizontal axis and signal level as the vertical axis in the fourth embodiment. (G) The horizontal axis in the fourth embodiment is time and the vertical axis is the gain value. The gain value of the gain switching unit The figure which shows the block configuration in background art (A) The horizontal axis in the background art is time, the vertical axis is the signal level, the timing signal for executing the offset correction of the offset correction execution command unit (b) the horizontal axis in the background art is time, FIG. 4C shows the offset detection execution signal of the offset detection unit with the vertical axis as the signal level. (C) Signal in the servo hold command unit with the horizontal axis in the background art as time and the vertical axis as the servo hold state binary signal level. FIG. 4D is a diagram showing a state where the servo is being held when the level is H, and a state where the servo is not held when the level is L. FIG. 4D shows the time in the horizontal axis in the background art and the error signal generation output signal level in the vertical axis. (E) Illumination output signal of the light irradiation unit with the horizontal axis in the background art as time and the vertical axis as the light beam irradiation signal level Figure shows The figure which shows the block configuration in background art (A) The horizontal axis in the background art is time, the vertical axis is the buffer accumulation level, and the signal of the read information storage unit is shown. (B) The horizontal axis in the background art is time, and the vertical axis is the signal level. FIG. 4C shows a timing signal for executing offset correction of the offset correction execution command section. In order to start offset correction of the offset correction operation control section with the horizontal axis in the background art as time and the vertical axis as signal level. FIG. 4D is a diagram showing an offset detection execution signal of the offset detection unit with the horizontal axis representing time and the vertical axis representing signal level in the background art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical disk 10 Optical head 11 Light irradiation part 12 Beam splitter 13 Condensing lens 14 Light receiving part 15 Focus actuator 20 Focus error signal generation part 21 Focus filter 22 Offset correction execution command part 23 Offset detection part 24 Servo hold command part 25 Laser control part 26 Offset Correction Unit 30 Offset Correction Operation Control Unit 31 Disk Reading Unit 32 Reading Information Storage Unit 40 Black Dot Detection Unit 41 Stabilization State Determination Unit 42 Offset Correction Operation Control Unit 43 Offset Detection Unit 44 Reference Voltage Generation Unit 45 Input Signal Switching Command Unit 46 Input signal changeover switch 50 Focus error signal generation analog unit 51 Focus error signal generation digital unit 52 CAPA detection unit 53 Offset detection unit 54 Offset correction operation control unit 55 Setting State Determination Unit 60 Focus Pulling Execution Command Unit 61 Focus Pulling Control Unit 62 Focus Drive Output Changeover Switch 63 Offset Correction Operation Control Unit 64 Setting State Determination Unit 70 Forced Execution Determination Unit 71 Gain Switching Unit 72 Setting State Determination Unit

Claims (28)

An optical disc apparatus that performs at least one of recording and reproduction on an optical disc having an information surface,
An irradiation means for irradiating a light beam;
Converging means for converging the light beam irradiated by the irradiating means on the optical disc;
A light receiving means for receiving reflected light from the optical disc and outputting an electrical signal corresponding to the amount of light received;
Input switching means for outputting either a signal from the light receiving means or a reference voltage signal;
Servo error signal generation means for generating at least one servo error signal of a focus error signal corresponding to a defocus of a light beam on an optical disc and a tracking error signal corresponding to a track shift from a signal from the input switching means,
Servo filter means for generating a signal for controlling the focal position of the light beam in accordance with a signal from the servo error signal generating means;
Servo hold means for holding the operation of the servo filter means;
Servo settling state determination means for determining whether the focal position control of the light beam is settling;
Detection operation command means for outputting a timing signal for starting detection of the offset;
A detection start command means for outputting a timing signal for starting offset detection when the determination result of the servo settling state determination means is in a settling state based on the timing signal from the detection operation command means;
Based on the timing signal from the detection start command means, the servo hold means holds the servo signal of the servo filter means in the light beam irradiation state and switches so that the reference voltage signal is output from the input switching means. An optical disc apparatus comprising: an offset detection unit that detects an offset from a signal of an error signal generation unit. The offset detection means integrates the detected offsets each time an offset is detected based on a timing signal from a detection start command means, and outputs an offset average value for a predetermined number of detections as a detection offset. 1. The optical disc device according to 1. Based on the timing signal from the detection operation command means, the detection start command means outputs an integration discard signal for discarding the integrated value of the offset when the determination result of the servo settling state determination means is in a non-settling state, and the offset detection means 3. The optical disc apparatus according to claim 2, wherein the integrated value of the offset is discarded based on the integrated discard signal from the detection start command means. Based on the timing signal from the detection operation command means, the detection start command means delays the output of the timing signal for starting the offset detection until it changes to the settling state when the determination result of the servo settling state judging means is in the non-settling state. The optical disc apparatus according to claim 1, wherein 2. The optical disk apparatus according to claim 1, wherein the servo error signal generating means has a digital signal processor in the digital circuit, and generates a servo error signal by software processing operating on the digital signal processor. And an offset correction unit that calculates an offset correction signal based on the detected offset from the offset detection unit and applies an offset correction value to the signal from the analog circuit to the digital circuit of the servo error signal generation unit. The optical disc apparatus according to claim 1. 2. An offset correction unit that calculates an offset correction signal based on a detected offset from the offset detection unit and applies an offset correction value to an input signal of the servo error signal generation unit. Optical disk device. 2. An optical disc apparatus according to claim 1, further comprising: an offset correction unit that calculates an offset correction signal based on a detected offset from the offset detection unit and applies an offset correction value to an input signal of the servo filter unit. . Circuit switching means for switching the circuit setting of the servo error signal generating means to reproduction circuit setting or recording circuit setting, and the offset detecting means arbitrarily switches the circuit setting of the servo error signal generating means by the circuit switching means. The optical disc apparatus according to claim 1. 2. The optical disk apparatus according to claim 1, wherein the servo settling state determining means determines that the settling state is in a non-settling state while the black dots pass. 2. The optical disk apparatus according to claim 1, wherein the servo settling state determining means determines that the settling state is not set while the air bubble is passing. 2. The optical disc apparatus according to claim 1, wherein the servo settling state determining means determines that the portion where the address information of the optical disc is recorded is in a non-settling state while the focal point of the light beam passes. 2. The optical disc apparatus according to claim 1, wherein the servo settling state determining means determines that the light beam focus control is in the non-settling state for a predetermined time after the focus control of the light beam changes from the non-settling state to the settling state. 2. The optical disc apparatus according to claim 1, wherein the servo settling state determining means predicts a timing at which the focus control of the light beam is in a non-settling state, and determines that it is in a non-settling state a predetermined time before the predicted timing. . And a focus pull-in means for searching for the focal position of the light beam at which the focus error signal is substantially zero, and the servo settling state determination means determines that the focus pull-in means is in a non-settling state during operation. The optical disk device according to claim 1. Tracking pull-in means for searching for the focal position of the light beam at which the tracking error signal is substantially zero, and the servo settling state determining means determines that the tracking pull-in means is in a non-settling state during operation. The optical disk device according to claim 1. 2. The optical disc apparatus according to claim 1, further comprising a focus jump unit that jumps between layers of the optical disc, wherein the servo settling state determination unit determines that the state is not set during the jump operation by the focus jump unit. A radial direction moving means for moving the focal point of the light beam in the radial direction of the optical disk, and the servo settling state determining means is in a non-settling state while the focal point of the light beam is moved in the radial direction of the optical disk by the radial direction moving means. 2. The optical disc apparatus according to claim 1, wherein the determination is made. 2. The recording apparatus according to claim 1, further comprising a recording unit that performs a recording operation on the optical disc, wherein the servo settling state determination unit determines that the recording unit is in a non-settling state for a predetermined time after the recording operation is started. Optical disk device. 2. The recording apparatus according to claim 1, further comprising: a recording unit that performs a recording operation on the optical disc, wherein the servo settling state determining unit determines that the recording unit is in a non-settling state for a predetermined time after the recording operation by the recording unit is completed. Optical disk device. Recording state determining means for determining whether the track on the optical disk is in a recorded state or an unrecorded state, and the servo settling state determining means is not set for a predetermined time after the determination by the recording state determining means is changed from unrecorded to recorded. 2. The optical disk apparatus according to claim 1, wherein the optical disk apparatus is determined to be in a set state. Recording state determining means for determining whether a track on the optical disk is in a recorded state or an unrecorded state, and the servo settling state determining means is configured for a predetermined time after the determination by the recording state determining means changes from recorded to unrecorded. 2. The optical disk apparatus according to claim 1, wherein the optical disk apparatus is determined to be in a set state. If the offset detection is not executed even after a predetermined time has elapsed since the offset detection by the offset detection means executed immediately before, a timing signal for immediately starting the offset detection is output regardless of the timing signal from the detection start command means. 2. The optical disk apparatus according to claim 1, further comprising forcible execution means. When temperature detection means for detecting the temperature inside the optical disc device and offset detection by the offset detection means executed immediately before based on the temperature from the temperature detection means, even if the temperature changes beyond a predetermined amount, offset detection is not executed. 2. The optical disk apparatus according to claim 1, further comprising forcible execution means for outputting a timing signal for immediately starting offset detection irrespective of the timing signal from the detection start command means. If the offset detection is not executed even after a predetermined time has passed since the offset detection by the offset detection means executed immediately before, the offset detection is performed based on the timing signal from the detection operation command means regardless of the timing signal from the detection start command means. 2. The optical disk apparatus according to claim 1, further comprising forcible execution means for outputting a timing signal for starting. When temperature detection means for detecting the temperature inside the optical disc device and offset detection by the offset detection means executed immediately before based on the temperature from the temperature detection means, even if the temperature changes beyond a predetermined amount, offset detection is not executed. 2. A forced execution means for outputting a timing signal for starting offset detection based on the timing signal from the detection operation command means regardless of the timing signal from the detection start command means. The optical disk device described. The forcible execution means includes a gain switching means for outputting a gain switching command when the offset detection by the offset detecting means is completed, and for switching the gain higher by a predetermined amount based on the gain switching command from the forcing execution means. 27. The optical disc apparatus according to claim 23, claim 24, claim 25, or claim 26. An optical disc apparatus that performs at least one of recording and reproduction on an optical disc having an information surface,
An irradiation means for irradiating a light beam;
Converging means for converging the light beam irradiated by the irradiating means on the optical disc;
A light receiving means for receiving reflected light from the optical disc and outputting an electrical signal corresponding to the amount of light received;
Input switching means for outputting either a signal from the light receiving means or a reference voltage signal;
Servo error signal generating means for generating, from an analog circuit, at least one servo error signal of a focus error signal corresponding to a defocus of a light beam on an optical disk and a tracking error signal corresponding to a track shift from a signal from the input switching means When,
Servo filter means for generating a signal for controlling the focal position of the light beam in accordance with a signal from the servo error signal generating means;
Servo hold means for holding the operation of the servo filter means;
Servo settling state determination means for determining whether the focal position control of the light beam is settling;
Detection operation command means for outputting a timing signal for starting detection of the offset;
A detection start command means for outputting a timing signal for starting offset detection when the determination result of the servo settling state determination means is in a settling state based on the timing signal from the detection operation command means;
Based on the timing signal from the detection start command means, the servo hold means holds the servo signal of the servo filter means in the light beam irradiation state and switches so that the reference voltage signal is output from the input switching means. An optical disc apparatus comprising: offset detection means for detecting an offset from a signal to an error signal generation means.

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