JPH10112041A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the time duration during a power supply tunring on operation and the time duration between a disk exchange and a disk reproducing. SOLUTION: The device conducts an automatic adjustment of a focus bias by adding a focus bias voltage to a focus error signal. The device consists of a first storage means 8 which stores a focus bias voltage value, a second storage means 13 which stores the range of a jitter amount that is larger than a beforehand set minimum jitter amount for a prescribed amount and a control means 7 which conducts a focus control by adding the bias voltage value stored in the means 8 to a focus error signal if the jitter amount by the bias voltage value stored in the means 8 is within the range of the jitter amount stored in the means 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic adjustment of a focus bias of an optical disk of an optical disk device.

[0002]

2. Description of the Related Art FIG. 4 is a schematic configuration diagram of an optical disk device. In FIG. 4, an optical disc 1 is driven to rotate by a spindle motor 2, and an optical pickup 3 reads bits formed on a signal recording surface of the optical disc 1 and outputs a reproduction signal.

The signal output from the optical pickup 3 is amplified by an RF amplifier 4 and then amplified by a servo processing unit 5.
Various servo processing controls such as focus servo, tracking servo, slide servo, and spindle servo are performed by an LSI CXD2545 (manufactured by Sony Corporation), and the servo driver 6 controls the rotation of the spindle motor 2 and the focus of the optical pickup 3. , Tracking control and the like. The control means 7 gives the servo processing means 5 an operation command for controlling each operation of the spindle motor 2 and the optical pickup 3 and the like, and also gives an instruction for automatic adjustment of the focus bias when the power is turned on or when the optical disk is replaced. Is going.

Next, the servo processing means 5 for automatically adjusting the focus bias will be described with reference to the block diagram of FIG. In FIG. 5, the servo processing means 5 is L
It is composed of SI. LS of servo processing means 5
A focus bias value set in advance for performing a focus servo is sent from the control means 7 to a focus bias register 9 inside I, and the focus bias register 9 adds a focus bias voltage corresponding to the focus bias value to the adder 10. To send to.

[0005] Focus error signal detecting means 1
The adder 10 adds the focus error signal sent from the controller 5 and the focus bias voltage sent from the focus bias register 9, and outputs the result to the servo driver 6 via the focus servo processor 11 inside the LSI of the servo processor 5. I do.

[0006] The servo driver 6 performs focus servo of the optical pickup 3 based on the output of the focus servo processing unit 11. After the signal output from the optical pickup 3 is amplified by the RF amplifier 4,
To the signal processing unit 12 inside the LSI. The signal processing unit 12 calculates a change in the amount of jitter of the RF signal when the focus bias voltage is changed, and outputs the calculated change to the control unit 7. The control means 7 instructs automatic adjustment of the focus bias for reducing the jitter amount.

Next, the automatic adjustment of the focus bias will be described with reference to FIG. This automatic adjustment is performed by using the fact that the amount of jitter of the RF signal is minimized when the objective lens of the optical pickup 3 is in focus on the optical disc 1 (just focus).

[0008] The focus bias value is increased or decreased, and two focus bias values, a large focus bias value and a small focus bias value, at which the jitter amount E is set in advance are measured. Subsequently, from the two measured focus bias values (points A and B in FIG. 6), a point C which is a central value between the two points is calculated, and this is set as an optimum focus bias value, and automatically adjusted. To end.

In the optical disk device having the above-described automatic focus bias adjusting device, the automatic adjustment of the focus bias is executed when the setting condition of the focus bias value changes, such as when the power is turned on or when the optical disk is replaced. I have.

FIG. 7 is a flowchart showing the operation. Power is turned on (ST1). Automatic adjustment of the focus bias is started (ST2). The focus bias value is measured (ST3). The focus bias value is increased or decreased until the amount of jitter becomes a constant amount E, and the focus bias values at points A and B shown in FIG. 6 are measured. Is calculated. A focus bias value is determined (ST4). It is determined whether an instruction to replace the disk has been given (ST5). When there is a disk exchange instruction (ST5)
YES), returning to (ST3). When there is no instruction to replace the disc (NO in ST5), the focus bias is set with the focus bias value at the midpoint C, and the automatic adjustment ends (ST6).

[0011]

However, since the focus bias of the optical disk is automatically adjusted when the power is turned on or after the optical disk is replaced, it takes a long time to reproduce the disk.

[0012]

Therefore, according to the optical disk apparatus of the present invention, an optical pickup for reading a signal recorded on a signal recording surface of an optical disk, and a focus error based on an output signal of the optical pickup. A focus error signal detecting means for detecting a signal, a bias voltage being applied to the focus error signal to measure a first bias voltage value at which a jitter amount of an output signal of the optical pickup is minimized, and the measured first bias voltage value A bias voltage is added to the bias voltage to increase the amount of jitter, and a bias voltage value when a predetermined amount of jitter is reached is measured. This is used as a second bias voltage value, and a negative bias voltage is used as the first bias voltage value. In addition, the amount of jitter is increased to measure the bias voltage value when the amount of jitter is reached, and this is used as the third bias voltage value. Control means for calculating an average value of the second bias voltage value and the third bias voltage value and performing focus control of the optical pickup as a bias voltage value to be added to the focus error signal; In an optical disc device that performs focus control by the control means every time the optical disc is replaced, the voltage value adjusted by adjusting the voltage value of the bias voltage applied to the focus error signal so that the amount of jitter in the preset reference optical disc is minimized. And a bias voltage value larger than the bias voltage value stored in the first storage means corresponding to the amount of jitter that can correct the error of the signal read from the signal recording surface of the optical disk. A second storage unit for storing two bias voltage values of the following bias voltage values, and after power-on or replacement of an optical disk. The jitter amount is measured by adding the bias voltage value stored in the first storage means to the focus error signal at the time of reproduction of the optical disc, and the voltage value of the bias voltage corresponding to the measured jitter amount is stored in the second storage means. The determination means compares and determines whether the bias voltage value is within the range of the stored bias voltage value, and is stored in the first storage means when the determination means determines that the bias voltage value is within the range of the bias voltage value stored in the second storage means. A control means for performing focus control with a bias voltage value is provided.

According to a second aspect of the present invention, in the optical disk apparatus according to the first aspect, the first storage means comprises a volatile memory, and the control means comprises an optical disk to be reproduced at power-on. And measuring the focus bias voltage value at which the jitter amount is minimized, and storing the bias voltage value in the first storage means.

Therefore, the amount of jitter is measured by using the focus bias voltage value stored in the first storage means, and when the measured amount of jitter is smaller than the amount of jitter which can correct the error of the signal read from the signal recording surface of the optical disk. , Without performing automatic adjustment of focus bias
Since the reproduction of the optical disk is performed using the focus bias voltage value stored in the storage means, it is possible to shorten the time until the start.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the optical disk drive of the present invention will be described with reference to the schematic drawing of FIG. In FIG. 1, an optical disc 1 is driven to rotate by a spindle motor 2, and reads a bit formed on a signal recording surface of the optical disc 1 by an optical pickup 3 to output a reproduction signal.

After the signal output from the optical pickup 3 is amplified by the RF amplifier 4, various types of servo processing control such as focus servo, tracking servo, slide servo, and spindle servo are performed by the LSI of the servo processing means 5. ing. The servo driver 6 controls the rotation of the spindle motor 2, focus servo and tracking servo of the optical pickup 3, and reproduces the optical disk 1.

The control means 7 gives an operation command for controlling the servo processing means 5, and gives an instruction for automatically adjusting the focus bias when the power is turned on or when the optical disk is replaced. A first storage means 8 is connected to the control means 7 and stores a focus bias value when automatic adjustment has already been performed.

Further, the control means 7 controls the bias voltage value larger than the bias voltage value stored in the first storage means 8 corresponding to the amount of jitter capable of correcting the error of the signal read from the signal recording surface of the optical disk. Storage means 13 storing two bias voltage values of the following bias voltage values:
Is connected to The control means 7 is stored in the first storage means 8 in order to determine whether the focus bias needs to be adjusted when the setting condition of the focus bias voltage changes, such as when the power is turned on or when the optical disk is replaced. The determination unit 14 determines whether the current focus bias value is within the range of the two bias voltage values stored in the second storage unit 13.

When the focus bias value is within the range of the two bias voltage values stored in the second storage means 13, the focus bias value stored in the first storage means 8 is stored in the servo processing means 5. Is sent to the focus bias register 9 inside the controller to set the voltage value of the focus bias. Note that the servo processing means 5
Since the configuration is the same as that shown in FIG.

Next, the flow of processing when a nonvolatile memory is used as the first storage means 8 in the above configuration will be described with reference to the flowchart of FIG. In FIG. 2, the power is turned on (ST
1). Start automatic adjustment of focus bias (ST
2). The control means 7 reads the focus bias value stored in the nonvolatile memory in advance (ST3). As the focus bias value stored in the non-volatile memory, the focus bias value at the time of just focus adjusted by the reference disk is stored in advance in a manufacturing process of a factory or the like.

The focus bias value read by the control means 7 is sent to the focus bias register 9 in the servo processing means 5, and the focus bias voltage is sent from the focus bias register 9. Then, the voltage of the focus bias is added to the focus error signal from the focus error signal detection unit 15 by the adder 10 and output to the servo driver 6 via the focus servo processing unit 11. Then, the optical pickup 3 controlled by the focus servo signal output from the servo driver 6
Is amplified by the RF amplifier 4, and the signal processing unit 12 inside the servo processing unit 5 calculates the jitter amount e (ST4).

As shown in FIG. 6, a jitter amount F capable of correcting an error of a signal read from a signal recording surface of an optical disk set in advance in a second storage means 13 and a signal processing unit 1
The determination means 14 compares and determines the jitter amount e calculated in step 2 (ST5). The jitter amount F preset in the second storage means 13 is determined within a range in which an error occurring in data read from the signal recording surface of the optical disc 1 can be corrected to correct data.

As a result of the determination by the determination means 14, when the jitter amount e is within the range of the jitter amount F in which the error can be corrected for the signal read from the signal recording surface of the optical disk set in advance (ST5 YES), the nonvolatile memory The focus bias value stored in advance is sent to the servo processing unit 5. It is determined whether an instruction to replace the disk has been issued (S
T6). When there is a disk exchange instruction (ST6
YES), returning to (ST3). If there is no instruction to change the disc (NO in ST6), the automatic adjustment of the focus bias ends (ST7).

As a result of the judgment by the judging means 14, when the jitter amount exceeds the range of the jitter amount F in which the signal read from the signal recording surface of the optical disk preset in the second storage means 13 can be corrected (ST5 NO 6) The focus bias value is increased or decreased until the amount of jitter becomes a constant amount E, and the focus bias values at points A and B shown in FIG. 6 are measured. The focus bias value at point C is obtained (ST8). Determine the focus bias value (ST
9). The determined focus bias value is stored in the nonvolatile memory as the first storage means 8 (ST10). (S
Return to T6).

Next, the flow of processing when a volatile memory is used for the first storage means 8 will be described with reference to the flowchart of FIG. In FIG. 3, the power is turned on (ST1). Automatic adjustment of the focus bias is started (ST2). It is determined whether the focus bias is automatically adjusted first after power-on (ST3). In the case of automatic adjustment of the focus bias performed first after the power is turned on (ST3 YES), the focus bias value is increased or decreased until the amount of jitter becomes a constant amount E, and the focus bias values at points A and B shown in FIG. 6 are measured. Then, a focus bias value at the middle point C is obtained from the focus bias value at the point A and the focus bias value at the point B (ST4).

Determining the focus bias value (ST
5). The determined focus bias value is stored in the volatile memory of the first storage means 8 (ST6). It is determined whether an instruction to replace the disk has been given (ST7). If there is an instruction to replace the disk (ST7 YES), the process returns to (ST3). If there is no instruction to replace the disk (ST7
NO), the automatic adjustment of the focus bias ends, and the reproduction of the optical disk device is started. (ST8).

If the focus bias is not automatically adjusted for the first time after the power is turned on (ST3 NO), the focus bias value stored in the volatile memory of the first storage means 8 is obtained by the first measurement of the focus bias after the power is turned on. Is read out to the control means 7 (ST9). The jitter amount e is calculated using the set focus bias value (ST1).
0).

The calculated jitter amount e and the jitter amount F preset in the second storage means 13 are determined by the determination means 14 (ST11). As a result of the determination by the determination means 14, the second
When the jitter amount e is within the range of the jitter amount F set in advance in the storage means 13 (YES in ST12), the focus bias value is set in advance in the volatile memory of the first storage means 8 (ST7). Return to). Judgment means 1
As a result of the determination in step 4, when the jitter amount e exceeds the range of the jitter amount F preset in the second storage means 13,
Return to (ST4).

As described above, the determination means 14 determines whether the focus bias value stored in the first storage means 8 is within the range of the preset jitter amount F stored in the second storage means 13. When it is determined that the focus bias value is within the range of the jitter amount F, the processing routine for automatically adjusting the focus bias is omitted. Therefore, when a nonvolatile memory is used as the first storage unit 8, By measuring the amount of jitter with a focus bias value stored in advance, the frequency of automatic adjustment of the focus bias after the power is turned on can be omitted more frequently, and the time required to start reproduction can be reduced.

When a volatile memory is used for the first storage means 8, after power is turned on, the focus bias of the optical disk to be reproduced is automatically adjusted, and the obtained focus bias value is stored. When the optical disc is replaced, the amount of jitter is measured using the focus bias value stored in the volatile memory, so the frequency of automatic adjustment of the focus bias when the optical disc is replaced can be omitted more frequently, and the time until playback starts Can be shortened. Although the embodiment of the present invention has been described using an example in which the present invention is applied to focus control, the present invention is also applicable to tracking control.

[0031]

According to the present invention, the control means is provided with a processing procedure for omitting the automatic adjustment of the focus bias.
It is possible to shorten the time until the reproduction of the optical disk is started.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an optical disk device showing one embodiment of the present invention.

FIG. 2 is a flowchart when a nonvolatile memory is used as a storage unit of the focus bias adjusting device according to the embodiment of the present invention.

FIG. 3 is a flowchart showing a practical example of the present invention in which a volatile memory is used as a storage unit of the focus bias adjusting device as a storage unit.

FIG. 4 is a schematic configuration diagram of a conventional optical disk device.

FIG. 5 is a block diagram of a servo processing LSI for adjusting a focus bias.

FIG. 6 is a diagram illustrating adjustment of a focus bias.

FIG. 7 is a flowchart for performing conventional focus bias adjustment.

[Explanation of symbols]

Reference Signs List 1 optical disk 2 spindle motor 3 optical pickup 4 RF amplifier 5 servo processing means 6 servo driver 7 control means 8 first storage means 9 focus bias register 10 adder 11 focus servo processing unit 12 signal processing unit 13 second storage means 14 Judging means 15 Focus error signal detecting means

Claims (2)

[Claims] 1. An optical pickup for reading a signal recorded on a signal recording surface of an optical disk, a focus error signal detecting means for detecting a focus error signal from an output signal of the optical pickup, and a bias voltage applied to the focus error signal. A first bias voltage value at which the jitter amount of the output signal of the optical pickup is minimized is measured, and a bias voltage is added to the measured first bias voltage value to increase the jitter amount to a predetermined jitter amount. A bias voltage value at the time of reaching is measured, and this is set as a second bias voltage value. A negative bias voltage is added to the first bias voltage value to increase the amount of jitter, and the bias at the time when the amount of jitter reaches the jitter amount is obtained. A voltage value is measured, and this is set as a third bias voltage value, and an average of the second bias voltage value and the third bias voltage value is calculated. A control unit that calculates a value and performs focus control of the optical pickup as a bias voltage value that adds the calculated average value to the focus error signal. The control unit performs the focus control every time power is turned on or the optical disk is replaced. In an optical disk device that performs control,
First storage means for adjusting the voltage value of the bias voltage applied to the focus error signal so as to minimize the amount of jitter in the preset reference optical disk and storing the adjusted voltage value; and reading from the signal recording surface of the optical disk. A second bias voltage value storing a bias voltage value larger than a bias voltage value stored in the first storage unit and a bias voltage value smaller than the bias voltage value stored in the first storage unit, the bias voltage value corresponding to a jitter amount capable of correcting the error of the signal. The jitter amount is measured by adding the bias voltage value stored in the first storage unit to the focus error signal at the time of reproducing the optical disk after the power is turned on or after the optical disk is replaced, and the jitter amount is measured. Determining means for determining whether the voltage value of the bias voltage to be applied is within the range of the bias voltage value stored in the second storage means; When the stage determines that the bias voltage value is within the range of the bias voltage value stored in the second storage means, the control means performs focus control by adding the bias voltage value stored in the first storage means to a focus error signal. An optical disk device, comprising: 2. The optical disk device according to claim 1, wherein the first storage means comprises a volatile memory, and the control means measures a voltage value of a focus bias at which a jitter amount becomes minimum in the optical disk reproduced at power-on. An optical disk device, wherein a bias voltage value is stored in a first storage means.