JP2006268926A - Optical disk player - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk player capable of carrying out CAV control without using an FG pulse signal. <P>SOLUTION: This player is equipped with an optical pickup for reading the recorded information of the optical disk, an FE generation section for generating a focus error signal from the output of the optical pickup, a periodical component extracting section for extracting a present rotational period of the optical disk from the focus error signal, and a CAV control section for rotationally controlling the optical disk at a constant angular velocity on the basis of the present rotational period and a predetermined target rotational period. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical disk reproducing apparatus that reproduces information recorded on an optical disk using an optical pickup, and more particularly to a method for controlling a spindle motor that rotates an optical disk.

  As a method for controlling the speed of a spindle motor that rotates an optical disk in an optical disk reproducing apparatus that reproduces information recorded on the optical disk using an optical pickup, control of the spindle motor so that the rotational angular velocity of the optical disk is constant (hereinafter, CAV control). ) Method is known. Also, as a different system, a spindle motor control system (hereinafter referred to as CLV control) is known in which the linear velocity of the optical disk is constant with respect to the optical pickup.

  In order to maintain the spindle motor control by CLV control, it is necessary to be able to measure the linear velocity of the optical disc with respect to the optical pickup. In an optical disk reproducing apparatus, the spindle motor is generally controlled by CAV control or open loop when the linear velocity of the optical disk relative to the optical pickup cannot be measured and CLV control cannot be maintained. Is.

  A conventional optical disk reproducing apparatus is a circuit for generating a fixed number of pulse signals per rotation, for example, six pulse signals per rotation, as means for measuring the rotational angular velocity of the optical disk for performing CAV control of the spindle motor. In other words, a so-called FG (Frequency Generator) pulse signal generation circuit is attached to the spindle motor (for example, see Patent Document 1).

FIG. 9 is a block diagram showing a conventional optical disk reproducing apparatus.
As shown in FIG. 9, the conventional optical disk reproducing apparatus includes a spindle motor 910, an optical pickup 911, a servo error signal generation unit 901, a servo control unit 902, an FG pulse 903 from the spindle motor, and a rotation cycle. It comprises a measuring unit 904, a CAV control unit 905, and a target rotation period 906.

A servo error signal generation unit 901 generates a focus error signal and a tracking error signal from the output of the light receiving element of the optical pickup 911.
The servo control unit 902 generates a drive output signal for the optical pickup 911 based on various error signals generated by the servo error signal generation unit 901.

  The rotation period measuring unit 904 measures the rotation period of the optical disc based on the interval of the FG pulses 903 from the spindle motor 910. For example, the rotation period measurement unit 904 includes an edge detection circuit that detects an edge of the FG pulse 903 and an edge interval count circuit that counts the edge interval.

  The CAV control unit 905 generates a drive output signal for the spindle motor 910 based on the rotation cycle of the optical disk measured by the rotation cycle measurement unit 904 and a predetermined target rotation cycle 906.

In the conventional optical disk reproducing apparatus configured as described above, the CAV control unit 905 has a spindle motor so that the rotation period of the optical disk based on the FG pulse 903 measured by the rotation period measurement unit 904 matches the target rotation period 906. CAV control was performed by controlling 910.
JP 10-49982 A

  However, since the conventional optical disk reproducing apparatus as described above uses an FG pulse signal to measure the rotation period for CAV control of the spindle motor, it is necessary to attach an FG pulse signal generation circuit to the spindle motor. The problem is that the generation circuit causes an increase in the cost of the optical disk playback device, and when the spindle motor is controlled in an open loop, the rotational angular velocity of the optical disk cannot be accurately controlled, and the spindle motor runs away. There was a problem that sometimes.

  The present invention has been made to solve the above-described conventional problems, and an object thereof is to provide an optical disk reproducing apparatus capable of performing CAV control without using an FG pulse signal.

According to a first aspect of the present invention, there is provided an optical disc reproducing apparatus comprising: an optical pickup that reads information recorded on an optical disc; an FE generator that generates a focus error signal from the output of the optical pickup; and a focus error signal from the FE generator. A focus servo unit that controls a relative position of the optical pickup and the optical disc in the focal direction, a period component extraction unit that extracts a current rotation cycle of the optical disc from the focus error signal, and the extracted current rotation cycle, And a CAV control unit that controls the rotation of the optical disk at a constant angular velocity based on a predetermined target rotation period.
Thus, by performing CAV control using the period of the surface blur component of the optical disc, there is an effect that CAV control can be performed without using an FG pulse signal.

An optical disk reproducing apparatus according to a second aspect of the present invention is the optical disk reproducing apparatus according to the first aspect, wherein the periodic component extraction unit extracts a signal of a predetermined band from the focus error signal, and the band A binary signal generation unit that converts the output of the pass filter into a binary signal at a zero cross level; and an edge interval measurement unit that measures an edge interval of the binary signal, wherein the CAV control unit includes the current rotation period as the current rotation period. The edge interval is used.
Thus, by performing CAV control using the period of the surface blur component of the optical disc, there is an effect that CAV control can be performed without using an FG pulse signal.

An optical disk reproducing apparatus according to a third aspect of the present invention is the optical disk reproducing apparatus according to the first aspect, wherein the periodic component extraction unit extracts a signal having a predetermined frequency or less from the focus error signal, and the low-pass filter. A binary signal generation unit that converts the output of the filter into a binary signal at a predetermined ratio; and an edge interval measurement unit that measures an edge interval of the binary signal, wherein the CAV control unit includes the current rotation period as the current rotation period. The edge interval is used.
Thus, by performing CAV control using the period of the surface blur component of the optical disc, there is an effect that CAV control can be performed without using an FG pulse signal.

  According to a fourth aspect of the present invention, there is provided an optical disk reproducing apparatus according to the first aspect, wherein the focus servo unit has a low-pass filter for low-frequency operation for extracting a low-frequency component of the focus error signal. The periodic component extraction unit measures a binary signal generation unit that converts the output of the low-pass filter for low-frequency operation of the focus servo unit into a binary signal at a predetermined ratio, and measures an edge interval of the binary signal And an edge interval measuring unit that performs the operation, and the CAV control unit uses the edge interval as the current rotation period.

  As a result, by performing CAV control using the period of the disk runout component, CAV control can be performed without using the FG pulse signal, and the low-pass filter for low-frequency calculation of the focus servo unit By sharing the low-pass filter for extracting the rotation period component of the optical disc from the focus error signal, there is an effect that it is possible to suppress an increase in circuit scale.

  An optical disk reproducing apparatus according to a fifth aspect of the present invention is the optical disk reproducing apparatus according to the first aspect, wherein when the focus servo control by the focus servo unit is in an open state, the current rotation period is not updated and the previous time is updated. A period holding unit for holding a value is provided.

  As a result, by performing CAV control using the period of the disk runout component, CAV control can be performed without using the FG pulse signal, and when the focus servo control is in the open state, By using the rotation cycle measured last time as the current rotation cycle, there is an effect that the runaway of the spindle motor can be suppressed.

  An optical disk reproducing apparatus according to a sixth aspect of the present invention is the optical disk reproducing apparatus according to the first aspect, wherein when the focus servo control by the focus servo unit is in an open state, the target rotational period is the current rotational period. A period holding unit that holds the value of

  As a result, by performing CAV control using the period of the disk runout component, CAV control can be performed without using the FG pulse signal, and when the focus servo control is in the open state, By using the rotation period as the value of the current rotation period, there is an effect that the runaway of the spindle motor can be suppressed.

  An optical disc reproducing apparatus according to a seventh aspect of the present invention is the optical disc reproducing apparatus according to the first aspect, wherein a comparison unit that compares the current rotation period and the target rotation period, and a comparison result by the comparison unit, And a period holding unit that holds the previous value without updating the current rotation period when the difference between the current rotation period and the target rotation period is a predetermined value or more.

  Thus, CAV control using the period of the disc runout component of the disk can be performed without using the FG pulse signal, and the periodic component extraction means can perform the target rotation under the influence of noise or the like. When a value greatly different from the cycle is measured, the runaway of the spindle motor can be suppressed by using the rotation cycle measured last time.

  An optical disc reproducing apparatus according to an eighth aspect of the present invention is the optical disc reproducing apparatus according to the first aspect, wherein a comparison unit that compares the current rotation period and the target rotation period, and a comparison result by the comparison unit, A period holding unit that updates the target rotation period as the current rotation period when a difference between the current rotation period and the target rotation period is equal to or greater than a predetermined value;

  Thus, CAV control using the period of the disc runout component of the disk can be performed without using the FG pulse signal, and the periodic component extraction means can perform the target rotation under the influence of noise or the like. When a value significantly different from the cycle is measured, using the target rotation cycle as the current rotation cycle has an effect of suppressing the runaway of the spindle motor.

  An optical disc reproducing apparatus according to a ninth aspect of the present invention is the optical disc reproducing apparatus according to any one of the second to fourth aspects, comprising: a comparison unit that compares the current rotation period with the target rotation period; and the comparison unit. As a result of comparison, when the difference between the current rotation period and the target rotation period is equal to or greater than a predetermined value, a period holding unit that multiplies the edge interval and updates it as the current rotation period is provided.

  Thus, CAV control using the period of the disc runout component of the disk can be performed without using the FG pulse signal, and the periodic component extraction means can perform the target rotation under the influence of noise or the like. When a value significantly different from the period is measured, the runaway of the spindle motor can be suppressed by multiplying the edge interval and using it as the current rotation period.

  An optical disk reproducing apparatus according to a tenth aspect of the present invention includes an optical pickup that reads information recorded on an optical disk, an FE generation unit that generates a focus error signal from the output of the optical pickup, and a first optical disk from the focus error signal. A first period component extraction unit that extracts a current rotation period of the optical disk, a TE generation unit that generates a tracking error signal from the output of the optical pickup, and a second current rotation period of the optical disc that is extracted from the tracking error signal A second cycle component extraction unit; a selection unit that selects one of the first current rotation cycle and the second current rotation cycle; and the current rotation cycle selected by the selection unit and a predetermined value And a CAV control unit that controls the rotation of the optical disk at a constant angular velocity based on the target rotation period.

  As a result, there is an effect that CAV control can be performed without using an FG pulse signal by performing CAV control using the period of the disk runout component or the period of eccentricity of the disk.

  An optical disk reproducing apparatus according to an eleventh aspect of the present invention is the optical disk reproducing apparatus according to the tenth aspect, wherein the selection unit has a period of the first current rotation period and the second current rotation period. The smaller one is selected.

  As a result, CAV control can be performed without using the FG pulse signal by performing CAV control using the period of the disk runout component or the period of eccentricity of the disk, and based on the focus error signal. In the case where the extracted rotation cycle is not accurate because the rotation cycle and the rotation cycle based on the tracking error signal are selected with the shorter cycle, that is, the rotation speed of the spindle motor is higher. However, there is an effect that the spindle motor can be prevented from being excessively controlled in the acceleration direction.

  An optical disc playback apparatus according to a twelfth aspect of the present invention is the optical disc playback apparatus according to the tenth aspect, wherein the selection unit is configured to select the target among the first current rotation period and the second current rotation period. The one with the smaller difference from the rotation period is selected.

  As a result, CAV control can be performed without using the FG pulse signal by performing CAV control using the period of the disk runout component or the period of eccentricity of the disk, and based on the focus error signal. Of the rotation cycle and the rotation cycle based on the tracking error signal, the one with the smaller difference between the target rotation cycle is selected, so that it is possible to suppress the runaway of the spindle motor.

  An optical disk reproducing apparatus according to a thirteenth aspect of the present invention is the optical disk reproducing apparatus according to the first aspect, wherein a CLV control unit that controls the rotation of the optical disk at a constant linear velocity, and servo control by the CLV control unit is in an open state. And a period holding unit that holds the previous value without updating the current rotation period.

  Thus, CAV control using the period of the disk runout component can be performed without using the FG pulse signal, and when the servo control by the CLV control unit is in an open state. In addition, by using the rotation period measured last time, there is an effect that the runaway of the spindle motor can be suppressed.

  An optical disk reproducing apparatus according to a fourteenth aspect of the present invention is the optical disk reproducing apparatus according to the tenth aspect, further comprising a CLV control unit that controls rotation of the optical disk at a constant linear velocity, and the selection unit is controlled by the CLV control unit When the servo control is in an open state, the first current rotation cycle is selected, and when the servo control by the CLV control unit is in a closed state, the second current rotation cycle is selected. It is.

  As a result, CAV control can be performed without using an FG pulse signal by performing CAV control using the period of the disk runout component or the period of eccentricity of the disk. Since either the rotation cycle based on the focus error signal or the rotation cycle based on the tracking error signal is selected according to the servo control state, there is an effect that the runaway of the spindle motor can be suppressed. .

  An optical disc reproducing apparatus according to the present invention extracts an optical pickup that reads information recorded on an optical disc, an FE generator that generates a focus error signal from the output of the optical pickup, and extracts a current rotation period of the optical disc from the focus error signal. Since it includes a periodic component extraction unit and a CAV control unit that controls the rotation of the optical disk at a constant angular velocity based on the current rotation period and a predetermined target rotation period, CAV control is performed without using an FG pulse signal. There is an effect that can be.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of an optical disc reproducing apparatus according to Embodiment 1 of the present invention.
As shown in FIG. 1, the optical disk reproducing apparatus according to the first embodiment includes a spindle motor 110, an optical pickup 111, an FE generation unit 101, a focus servo control unit 102, a periodic component extraction unit 103, a target A rotation period 104 and a CAV control unit 105 are included.

  FIG. 2 is a diagram illustrating an example of a specific configuration of the periodic component extraction unit 103 in FIG. 1. In FIG. 2, reference numeral 201 denotes a predetermined frequency band from the focus error signal generated by the FE generation unit 101. A band-pass filter that extracts and outputs only the signal of, a binary signal generation unit that generates and outputs a binary signal by slicing the output signal of the band-pass filter 201 at a zero level, and 203 a binary signal generation unit An edge interval measuring unit that detects rising or falling edges of a binary signal from 202, measures the edge interval, and outputs a rotation period.

Next, the operation of the optical disk reproducing apparatus according to the first embodiment having the above-described configuration will be described.
FIG. 8 is a diagram showing an example of a signal waveform at each part in the optical disc reproducing apparatus according to the first embodiment.

  The FE generator 101 generates a focus error signal 801 from the output of the light receiving element of the optical pickup 111. The focus error signal 801 includes a rotation period component of the optical disk that is generated due to the surface shake of the optical disk. The focus servo 102 generates a drive output signal for the optical pickup 111 based on the focus error signal generated by the FE generation unit 101. The band-pass filter 201 of the periodic component extraction unit 103 extracts and outputs only a signal in a predetermined frequency band from the focus error signal generated by the FE generation unit 101. As a result, a post-bandpass filter signal 802, which is a signal obtained by extracting the rotation period component of the optical disc caused by the surface blur of the optical disc, is obtained. The binary signal generation unit 202 slices the output signal of the bandpass filter 201 at a zero level to generate and output a binarized signal 803. The edge interval measurement unit 203 measures the edge interval of the binarized signal 803 output from the binary signal generation unit 202 and outputs the measured value to the CAV control unit 105 as a rotation period. When the focus state of the focus servo unit 102 is in the closed state, the CAV control unit 105 controls the spindle motor 110 so that the rotation cycle output from the edge interval measurement unit 203 matches the target rotation cycle 104. Then, CAV control is performed. Here, the target rotation period 104 is set from an external microcomputer or the like (not shown).

  As described above, in the optical disc reproducing apparatus according to the first embodiment, the optical pickup 111, the FE generator 101 that generates the focus error signal from the output of the optical pickup 111, and the current rotation period of the optical disc are extracted from the focus error signal. A periodic component extraction unit 103 and a CAV control unit 105 that controls the rotation of the optical disk at a constant angular velocity based on the current rotation period and the target rotation period, and uses the period of the surface blur component of the optical disk included in the focus error signal. Since the control is performed, the CAV control can be performed without using the FG pulse signal.

  In the first embodiment, the periodic component extraction unit 103 uses a bandpass filter 201 that extracts a signal in a predetermined band from the focus error signal, and binarizes by slicing the output of the bandpass filter 201 at zero level. Although shown about what comprised the value signal generation part 202 and the edge space | interval measurement part 203 which measures the edge space | interval of the output of the binary signal generation part 202, as shown in FIG. A low-pass filter 1001 that extracts and outputs a signal having a frequency below a predetermined frequency band from the focus error signal, a binary signal generation unit 1002 that converts the output of the low-pass filter into a binary signal at a predetermined ratio, You may make it comprise with the edge space | interval measurement part 203 which measures the edge space | interval of the output of a binary signal production | generation part, and the said embodiment and The effects of the like.

  Further, when the periodic component extraction unit 103 is configured using the low-pass filter as described above, the low-pass filter may be shared with the low-pass calculation low-pass filter provided in the focus servo control unit. As a result, the expansion of the circuit scale can be suppressed.

Embodiment 2. FIG.
FIG. 3 is a block diagram showing a configuration of the optical disk reproducing apparatus according to the second embodiment of the present invention.
In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts, and 301 denotes the rotation period from the periodic component extraction unit 103 to the CAV control unit 105 based on the focus servo state of the focus servo control unit 102. It is a period holding unit.

Hereinafter, the operation of the optical disk reproducing apparatus according to the second embodiment will be described.
The FE generator 101 generates a focus error signal from the output of the light receiving element of the optical pickup 111. This focus error signal includes a rotation period component of the optical disk that is generated due to surface wobbling of the optical disk. The focus servo control unit 102 generates a drive output signal for the optical pickup 111 based on the focus error signal generated by the FE generation unit 101. The period component extraction unit 103 extracts the rotation period of the optical disc based on the focus error signal generated by the FE generation unit 101, and outputs the extracted rotation period to the period holding unit 301. Since the specific configuration and operation of the periodic component extraction unit 103 are the same as those of the optical disc playback apparatus according to the first embodiment, detailed description thereof is omitted. The cycle holding unit 301 updates the rotation cycle from the cycle component extraction unit 103 when the focus state of the focus servo unit 102 is closed, and the cycle when the focus state of the focus servo unit 102 is open. The previous value is held without updating the rotation period from the component extraction unit 103. When the focus state of the focus servo unit 102 is in the closed state, the CAV control unit 105 controls the spindle motor 110 so that the rotation cycle updated by the cycle holding unit 301 and the target rotation cycle 104 coincide with each other. When the focus state of the servo unit 102 is the open state, the spindle motor 110 is controlled so that the previous rotation cycle held by the cycle holding unit 301 matches the target rotation cycle 104.

  As described above, in the optical disk reproducing apparatus according to the second embodiment, the optical pickup, the FE generating unit that generates the focus error signal from the output of the optical pickup, and the period component extraction that extracts the current rotation period of the optical disk from the focus error signal. And a CAV control unit for controlling the rotation of the optical disk at a constant angular velocity based on the current rotation period and the target rotation period, and using the period of the surface blur component of the optical disk included in the focus error signal used for focus servo control. When the focus servo unit is in an open state, the cycle holding unit holds the previous value without updating the rotation cycle from the cycle component extraction unit. Since CAV control is used, CAV control is performed without using the FG pulse signal. Ukoto it is, even if a focus servo loop in an open state, it is possible to spindle motor it can be inhibited from runaway.

  In the second embodiment, the cycle holding unit has been shown to hold the previous value when the focus servo unit is in the open state. However, the cycle holding unit has the focus servo unit in the focus state. Instead of holding the previous value when in the open state, the target rotation cycle may be held as the value of the current rotation cycle.

Embodiment 3 FIG.
FIG. 4 is a block diagram showing a configuration of an optical disc reproducing apparatus according to Embodiment 3 of the present invention.
In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts. Reference numeral 401 denotes a linear velocity measuring unit that measures the rotation speed of the spindle motor as a linear velocity with respect to the optical disk from the output of the light receiving element of the optical pickup. A CLV control unit 403 generates a drive output signal for the spindle motor 110 based on the rotation period of the optical disk measured by the measurement unit 401, and a reference numeral 403 denotes a periodic component extraction unit 103 based on the servo state of the CLV control unit 402. , A cycle holding unit that outputs the rotation cycle to the CAV control unit 105, and 404 selects either the output of the CAV control unit 105 or the output of the CLV control unit 402 based on the servo state of the CLV control unit 402, A selector that outputs to the spindle motor 110.

Hereinafter, the operation of the optical disk reproducing apparatus according to the third embodiment will be described.
The FE generator 101 generates a focus error signal from the output of the light receiving element of the optical pickup 111. This focus error signal includes a rotation period component of the optical disk that is generated due to surface wobbling of the optical disk. The focus servo control unit 102 generates a drive output signal for the optical pickup 111 based on the focus error signal generated by the FE generation unit 101. The period component extraction unit 103 extracts the rotation period of the optical disc based on the focus error signal generated by the FE generation unit 101, and outputs the extracted rotation period to the period holding unit 403. Since the specific configuration and operation of the periodic component extraction unit 103 are the same as those of the optical disc playback apparatus according to the first embodiment, detailed description thereof is omitted.

  When the servo state of the CLV control unit 402 is the closed state, the cycle holding unit 403 updates the rotation cycle from the cycle component extraction unit 103, and the selector 404 selects the output of the CLV control unit 402. The control unit 402 controls the spindle motor 110 by CLV control. On the other hand, when the servo state of the CLV control unit 402 is an open state, the cycle holding unit 403 holds the previous value without updating the rotation cycle from the cycle component extraction unit 103, and the selector 404 holds the CAV control unit. Thus, the CAV control unit 105 performs CAV control of the spindle motor 110 so that the value held by the cycle holding unit 403 matches the target rotation cycle 104.

  When the servo state of the CLV control unit 402 is the closed state, the focus servo control state is always the closed state, so that the periodic component extraction unit 103 can extract the rotation period from the correctly detected focus error signal. Therefore, when the servo state of the CLV control unit 402 is the closed state, the cycle holding unit 403 updates the rotation cycle from the cycle component extraction unit 103 so that the servo state of the CLV control unit 402 is changed. When the open state is changed from the closed state, the accurate current rotation cycle updated immediately before that can be given to the CAV control unit 105, and the CAV control unit 105 can correctly CAV-control the spindle motor.

  As described above, in the optical disk reproducing apparatus according to the third embodiment, when the servo state of the CLV control unit is in the open state, the cycle holding unit holds the previous value without updating the rotation cycle from the cycle component extraction unit. Since it is used for CAV control, the runaway of the spindle motor can be suppressed even if the CLV control cannot be maintained.

  The cycle holding unit may hold the target rotation cycle as the value of the current rotation cycle instead of holding the previous value when the servo state of the CLV control unit is an open state.

Embodiment 4 FIG.
FIG. 5 is a block diagram showing a configuration of an optical disc reproducing apparatus according to Embodiment 4 of the present invention.
In the figure, the same reference numerals as those in FIG. 1 are the same or corresponding parts, and reference numeral 501 compares the rotation period from the periodic component extraction unit 103 with the target rotation period, A comparison unit that outputs a signal indicating whether or not the difference between the two is greater than or equal to a predetermined value, and 502 outputs the rotation period from the periodic component extraction unit 103 to the CAV control unit 105 based on the comparison result of the comparison unit 501 This is a period holding unit.

Hereinafter, the operation of the optical disk reproducing apparatus according to the fourth embodiment will be described.
The FE generator 101 generates a focus error signal from the output of the light receiving element of the optical pickup 111. This focus error signal includes a rotation period component of the optical disk that is generated due to surface wobbling of the optical disk. The focus servo control unit 102 generates a drive output signal for the optical pickup 111 based on the focus error signal generated by the FE generation unit 101. The period component extraction unit 103 extracts the rotation period of the optical disc based on the focus error signal generated by the FE generation unit 101, and outputs the extracted rotation period to the comparison unit 501 and the period holding unit 502. Since the specific configuration and operation of the periodic component extraction unit 103 are the same as those of the optical disc playback apparatus according to the first embodiment, detailed description thereof is omitted. The comparison unit 501 compares the rotation period from the period component extraction unit 103 with the target rotation period, and determines whether or not the difference between the rotation period from the period component extraction unit 103 and the target rotation period is a predetermined value or more. A signal indicating is output.

  If the value is equal to or less than the predetermined value, the cycle holding unit 502 is notified that the update is possible. If the value is equal to or greater than the predetermined value, the cycle holding unit 502 is notified that the update is not possible. The cycle holding unit 502 outputs the rotation cycle from the cycle component extraction unit 103 to the CAV control unit 105 based on the comparison result of the comparison unit 501.

  When the signal output from the comparison unit 501 indicates that the difference between the rotation cycle from the cycle component extraction unit 103 and the target rotation cycle is equal to or less than a predetermined value, the cycle holding unit 502 The rotation cycle from 103 is updated, and the CAV control unit 105 controls the spindle motor 110 so that the rotation cycle updated by the cycle holding unit 301 matches the target rotation cycle 104. On the other hand, when the signal output from the comparison unit 501 indicates that the difference between the rotation cycle from the cycle component extraction unit 103 and the target rotation cycle is equal to or greater than a predetermined value, the cycle holding unit 502 The CAV control unit 105 controls the spindle motor 110 so that the value held by the cycle holding unit 301 matches the target rotation cycle 104 without updating the rotation cycle from the extraction unit 103. .

  As described above, in the optical disk reproducing device according to the fourth embodiment, the rotation period cannot be updated in the period holding unit if the comparison unit has a difference between the target period and the rotation period from the period component extraction unit equal to or greater than a predetermined value. Since the period holding means holds the previous value without updating the rotation period, the period component extraction unit extracts a value that is significantly different from the target rotation period due to the influence of noise or the like. Even in this case, the runaway of the spindle motor can be suppressed.

Note that the cycle holding unit may hold the target rotation cycle as the value of the current rotation cycle instead of storing the previous value when the rotation cycle is not updated.
In addition, when the rotation cycle is not updated, the cycle holding unit may hold the value obtained by multiplying the edge interval as the value of the current rotation cycle instead of storing the previous value.

Embodiment 5. FIG.
FIG. 6 is a block diagram showing a configuration of an optical disc reproducing apparatus according to Embodiment 5 of the present invention.
In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts, 601 denotes a TE generation unit that generates a tracking error signal from the output of the light receiving element of the optical pickup 111, and 602 denotes a tracking error generated by the TE generation unit 601. A tracking servo control unit that generates a drive output signal for the optical pickup based on the signal, and a period component extraction unit 603 that extracts the rotation period of the optical disc based on the tracking error signal generated by the TE generation unit 601 , 604 receives a first rotation cycle from the periodic component extraction unit 103 and a second rotation cycle from the periodic component extraction unit 603, and selects one of them as an output to the CAV control unit 105. It is.

  FIG. 11 is a diagram illustrating an example of a specific configuration of the periodic component extraction unit 603 in FIG. 6. In FIG. 11, reference numeral 1101 denotes a frequency band determined in advance from the tracking error signal generated by the TE generation unit 601. A band-pass filter that extracts and outputs only the first signal 1102 is a binary signal generator 1102 that slices the output signal of the bandpass filter 1101 at a zero level to generate and output a binary signal 1103 is a binary signal generator An edge interval measuring unit that detects a rising or falling edge of a binary signal from 1102, measures the edge interval, and outputs a rotation period.

Hereinafter, the operation of the optical disk reproducing apparatus according to the fifth embodiment will be described.
The FE generator 101 generates a focus error signal from the output of the light receiving element of the optical pickup 111. This focus error signal includes a rotation period component of the optical disk that is generated due to surface wobbling of the optical disk. The focus servo control unit 102 generates a drive output signal for the optical pickup 111 based on the focus error signal generated by the FE generation unit 101. The period component extraction unit 103 extracts the rotation period of the optical disc based on the focus error signal generated by the FE generation unit 101, and outputs the extracted rotation period to the selection unit 604. Since the specific configuration and operation of the periodic component extraction unit 103 are the same as those of the optical disc playback apparatus according to the first embodiment, detailed description thereof is omitted.

  FIG. 12 is a signal waveform diagram for explaining the operation of the periodic component extraction unit 603. The TE generation unit 601 generates a tracking error signal 1201 from the output of the light receiving element of the optical pickup 111. This tracking error signal 1201 includes a rotation period component of the optical disk caused by the eccentricity of the optical disk. The tracking servo 602 generates a drive output signal for the optical pickup 111 based on the tracking error signal generated by the TE generation unit 601. The band pass filter 1101 of the periodic component extraction unit 603 extracts and outputs only a signal in a predetermined frequency band from the tracking error signal 1201 generated by the TE generation unit 601. As a result, a signal 1202 after passing through the bandpass filter, which is a signal obtained by extracting the rotation period component of the optical disk generated by the eccentricity of the optical disk, is obtained. The binary signal generation unit 1102 slices the output signal 1202 of the bandpass filter 1101 at a zero level to generate and output a binarized signal 1203. The edge interval measurement unit 1103 measures the edge interval of the binarized signal 1203 output from the binary signal generation unit 1102 and outputs this measurement value to the selection unit 604 as a rotation period.

  The selection unit 604 has a smaller cycle, that is, a faster one of the rotation cycle based on the focus error signal output from the periodic component extraction unit 103 and the rotation cycle based on the tracking error signal output from the periodic component extraction unit 603. The one indicating the rotation speed is selected, and the CAV control unit 105 performs CAV control so that the rotation cycle selected by the selection unit 604 matches the target rotation cycle 104. The selection unit 604 has a smaller one of the rotation cycle based on the focus error signal output from the periodic component extraction unit 103 and the rotation cycle based on the tracking error signal output from the periodic component extraction unit 603, that is, the spindle motor. By selecting the one with the higher rotation speed, control in the acceleration direction of the spindle motor becomes smaller, and even if the extracted rotation cycle is not accurate, the spindle motor is excessively controlled in the acceleration direction. Can be suppressed.

  As described above, in the optical disc reproducing apparatus according to the fifth embodiment, the optical pickup 111, the FE generating unit 101 that generates the focus error signal from the output of the optical pickup 111, and the first current rotation period of the optical disc from the focus error signal. A periodic component extracting unit 103 that extracts the second current rotation period of the optical disc from the tracking error signal, a TE generating unit 601 that generates a tracking error signal from the output of the optical pickup 111, Based on the selection unit 604 for selecting one of the first current rotation cycle and the second current rotation cycle, the current rotation cycle selected by the selection unit 604 and a predetermined target rotation cycle , And the CAV control unit 105 for controlling the rotation of the optical disk at a constant angular velocity. CAV control can be performed without using a signal, and the selection unit 604 can rotate the rotation cycle based on the focus error signal and the rotation cycle based on the tracking error signal, ie, the rotation of the spindle motor. Since the higher speed is selected, it is possible to suppress the spindle motor from being excessively controlled in the acceleration direction even when the extracted rotation cycle is not accurate.

  In the fifth embodiment, the selection unit 604 selects a rotation cycle based on the focus error signal and a rotation cycle based on the tracking error signal, which has a smaller cycle, that is, a spindle motor with a higher rotation speed. As described above, the selection unit 604 may select a rotation period based on the focus error signal and a rotation period based on the tracking error signal, which has a smaller difference between the target rotation period and the target rotation period. Good. In this case, there is an effect that the runaway of the spindle motor can be suppressed when any periodic component extraction means measures a value greatly different from the target rotation period due to noise or the like.

  In addition, the size of the surface blur and the amount of eccentricity differ depending on the disc, and either the rotation period obtained based on the focus error signal or the rotation period obtained based on the tracking error signal may not be sufficiently extracted. Of the rotation period based on the focus error signal output from the periodic component extraction unit 103 and the rotation period based on the tracking error signal output from the periodic component extraction unit 603, the selection unit 604 is currently extracted more clearly. More stable CAV control can be realized by selecting the rotation cycle and outputting to the CAV control unit 105.

Embodiment 6 FIG.
FIG. 7 is a block diagram showing a configuration of an optical disc reproducing apparatus according to Embodiment 6 of the present invention.
In the figure, the same reference numerals as those in FIG. 6 denote the same or corresponding parts. Reference numeral 701 denotes a linear velocity measuring unit that measures the rotation speed of the spindle motor as a linear velocity with respect to the optical disk from the output of the light receiving element of the optical pickup 111. A CLV control unit 703 generates a drive output signal for the spindle motor 110 based on the rotation period of the optical disk measured by the speed measurement unit 701, and the rotation period from the periodic component extraction unit 103 and the periodic component extraction unit 603 , A selection unit that selects one of them as an output to the CAV control unit 105 based on the servo state of the CLV control unit 702, and 704 is an output of the CAV control unit 105 and the CLV control unit 702. Is selected based on the servo state of the CLV control unit 702, and the spindle motor 1 A selector to be output to 0.

Hereinafter, the operation of the optical disk reproducing apparatus according to the sixth embodiment will be described.
The FE generator 101 generates a focus error signal from the output of the light receiving element of the optical pickup 111. This focus error signal includes a rotation period component of the optical disk that is generated due to surface wobbling of the optical disk. The focus servo control unit 102 generates a drive output signal for the optical pickup 111 based on the focus error signal generated by the FE generation unit 101. The period component extraction unit 103 extracts the rotation period of the optical disc based on the focus error signal generated by the FE generation unit 101, and outputs the extracted rotation period to the selection unit 703. Since the specific configuration and operation of the periodic component extraction unit 103 are the same as those of the optical disc playback apparatus according to the first embodiment, detailed description thereof is omitted.

  The TE generation unit 601 generates a tracking error signal from the output of the light receiving element of the optical pickup 111. This tracking error signal includes a rotation period component of the optical disk caused by the eccentricity of the optical disk. The tracking servo 602 generates a drive output signal for the optical pickup 111 based on the tracking error signal generated by the TE generation unit 601. The period component extraction unit 603 extracts the rotation period of the optical disc based on the tracking error signal generated by the TE generation unit 601, and outputs the extracted rotation period to the selection unit 703. Since the specific configuration and operation of the periodic component extraction unit 603 are the same as those of the optical disc playback apparatus according to the fifth embodiment, detailed description thereof is omitted.

  When the servo state of the CLV control unit 702 is the closed state, the selection unit 703 selects the rotation cycle from the periodic component extraction unit 603, the selector 704 selects the output of the CLV control unit 702, and the spindle is controlled by CLV control. The motor 110 is controlled.

  On the other hand, when the servo state of the CLV control unit 702 is an open state, the selection unit 703 selects the rotation period from the periodic component extraction unit 103, the selector 704 selects the output of the CAV control unit 105, and the CAV control unit 105 performs CAV control on the spindle motor 110 so that the rotation cycle from the cycle component extraction unit 103 and the target rotation cycle 104 coincide with each other.

  As described above, in the optical disk reproducing apparatus according to the sixth embodiment, when the servo state of the CLV control unit is the open state, CAV control of the spindle motor is performed using the rotation period based on the focus error signal. Even if the CLV control cannot be maintained, the runaway of the spindle motor can be suppressed.

  Note that the selection unit may select a rotation cycle based on the focus error signal and a rotation cycle based on the tracking error signal that has a smaller cycle, that is, a spindle motor having a higher rotation speed.

In addition, the selection unit may receive a target rotation cycle and select a rotation cycle based on the focus error signal and a rotation cycle based on the tracking error signal that has a smaller difference from the target rotation cycle. Good.
Further, when the spindle motor is in the CLV control state by the CLV control unit, the rotation cycle from the cycle component extraction unit may be set as the target rotation cycle.

  The present invention has a simple configuration and can be manufactured at low cost by performing CAV control without using an FG pulse signal, and is therefore useful for reducing the cost of an optical disk reproducing apparatus that reproduces CDs, DVDs, and the like. .

1 is a block diagram showing an optical disk reproducing device according to Embodiment 1 of the present invention. It is a block diagram which shows an example of a specific structure of the periodic component extraction part 103 in FIG. It is a block diagram which shows the optical disk reproducing | regenerating apparatus by Embodiment 2 of this invention. It is a block diagram which shows the optical disk reproducing | regenerating apparatus by Embodiment 3 of this invention. It is a block diagram which shows the optical disk reproducing | regenerating apparatus by Embodiment 4 of this invention. It is a block diagram which shows the optical disk reproducing | regenerating apparatus by Embodiment 5 of this invention. It is a block diagram which shows the optical disk reproducing | regenerating apparatus by Embodiment 6 of this invention. It is a signal waveform diagram for demonstrating the operation | movement which extracts a rotation period from a focus error signal. It is a block diagram which shows the conventional optical disk reproducing | regenerating apparatus. It is a block diagram which shows the other example of the concrete structure of the periodic component extraction part 103 in FIG. It is a block diagram which shows an example of a specific structure of the periodic component extraction part 603 in FIG. It is a signal waveform diagram for demonstrating the operation | movement which extracts a rotation period from a tracking error signal.

Explanation of symbols

101: FE generation unit 102: focus servo unit 103, 603: periodic component extraction unit 104: target rotation period 105: CAV control unit 110: spindle motor 111: optical pickup 201: band pass filter 202: binary signal generation unit 203: Edge interval measurement units 301, 403, 502: Period holding units 401, 701: Linear velocity measurement units 402, 702: CLV control units 404, 704: Selector 501: Comparison unit 601: TE generation unit 602: Tracking servo units 604, 703 : Selection unit 801: focus error signal 802: post-bandpass filter signal 803: binarized signal 901: servo error signal generation unit 902: servo control unit 903: FG pulse 904: rotation period measurement unit 905: CAV control unit 906: Target rotation period 910: Spindle motor 11: the optical pick-up

Claims (14)

An optical pickup for reading recorded information on the optical disc;
An FE generator for generating a focus error signal from the output of the optical pickup;
A focus servo unit that controls a relative position of the optical pickup and the optical disc in a focal direction based on a focus error signal from the FE generation unit;
A period component extracting unit that extracts a current rotation period of the optical disc (hereinafter referred to as a current rotation period) from the focus error signal;
A CAV control unit that controls the rotation of the optical disc at a constant angular velocity based on the extracted current rotation cycle and a predetermined target rotation cycle.
An optical disk reproducing apparatus characterized by the above. The optical disk reproducing apparatus according to claim 1,
The periodic component extraction unit includes:
A bandpass filter for extracting a signal of a predetermined band from the focus error signal;
A binary signal generation unit that converts the output of the bandpass filter into a binary signal at a zero cross level;
An edge interval measuring unit that measures an edge interval of the binary signal, and
The CAV control unit
Using the edge interval as the current rotation period,
An optical disk reproducing apparatus characterized by the above. The optical disk reproducing apparatus according to claim 1,
The periodic component extraction unit includes:
A low pass filter for extracting a signal having a predetermined frequency or less from the focus error signal;
A binary signal generation unit that converts the output of the low-pass filter into a binary signal at a predetermined ratio;
An edge interval measuring unit that measures an edge interval of the binary signal, and
The CAV control unit
Using the edge interval as the current rotation period,
An optical disk reproducing apparatus characterized by the above. The optical disk reproducing apparatus according to claim 1,
The focus servo unit has a low-pass filter for low-frequency operation for extracting a low-frequency component of the focus error signal,
The periodic component extraction unit includes:
A binary signal generation unit that converts the output of the low-pass filter for low-frequency operation of the focus servo unit into a binary signal at a predetermined ratio;
An edge interval measuring unit that measures an edge interval of the binary signal, and
The CAV control unit
Using the edge interval as the current rotation period,
An optical disk reproducing apparatus characterized by the above. The optical disk reproducing apparatus according to claim 1,
A cycle holding unit that holds a previous value without updating the current rotation cycle when focus servo control by the focus servo unit is in an open state, and
An optical disk reproducing apparatus characterized by the above. The optical disk reproducing apparatus according to claim 1,
A cycle holding unit that holds the target rotation cycle as a value of the current rotation cycle when focus servo control by the focus servo unit is in an open state;
An optical disk reproducing apparatus characterized by the above. The optical disk reproducing apparatus according to claim 1,
A comparison unit for comparing the current rotation period and the target rotation period;
As a result of the comparison by the comparison unit, when the difference between the current rotation cycle and the target rotation cycle is equal to or greater than a predetermined value, a cycle holding unit that holds the previous value without updating the current rotation cycle, Prepared,
An optical disk reproducing apparatus characterized by the above. The optical disk reproducing apparatus according to claim 1,
A comparison unit for comparing the current rotation period and the target rotation period;
A period holding unit that updates the target rotation period as the current rotation period when a difference between the current rotation period and the target rotation period is equal to or greater than a predetermined value as a result of comparison by the comparison unit; ,
An optical disk reproducing apparatus characterized by the above. In the optical disk reproducing device according to any one of claims 2 to 4,
A comparison unit for comparing the current rotation period and the target rotation period;
As a result of the comparison by the comparison unit, when the difference between the current rotation cycle and the target rotation cycle is equal to or greater than a predetermined value, a cycle holding unit that multiplies the edge interval and updates the current rotation cycle. Prepared,
An optical disk reproducing apparatus characterized by the above. An optical pickup for reading recorded information on the optical disc;
An FE generator for generating a focus error signal from the output of the optical pickup;
A first period component extracting unit for extracting a first current rotation period of the optical disc from the focus error signal;
A TE generator for generating a tracking error signal from the output of the optical pickup;
A second period component extracting unit for extracting a second current rotation period of the optical disc from the tracking error signal;
A selection unit for selecting one of the first current rotation period and the second current rotation period;
A CAV control unit that controls rotation of the optical disc at a constant angular velocity based on the current rotation cycle selected by the selection unit and a predetermined target rotation cycle.
An optical disk reproducing apparatus characterized by the above. The optical disk reproducing apparatus according to claim 10, wherein
The selection unit includes:
Of the first current rotation period and the second current rotation period, the smaller one is selected.
An optical disk reproducing apparatus characterized by the above. The optical disk reproducing apparatus according to claim 10, wherein
The selection unit includes:
Of the first current rotation period and the second current rotation period, the one having a smaller difference between the target rotation period and the first current rotation period is selected.
An optical disk reproducing apparatus characterized by the above. The optical disk reproducing apparatus according to claim 1,
A CLV controller for controlling the rotation of the optical disk at a constant linear velocity;
A cycle holding unit that holds the previous value without updating the current rotation cycle when the servo control by the CLV control unit is in an open state,
An optical disk reproducing apparatus characterized by the above. The optical disk reproducing apparatus according to claim 10, wherein
A CLV controller for controlling the rotation of the optical disk at a constant linear velocity;
The selection unit includes:
When the servo control by the CLV control unit is in an open state, the first current rotation cycle is selected, and when the servo control by the CLV control unit is in a closed state, the second current rotation cycle is selected. To
An optical disk reproducing apparatus characterized by the above.

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