JP3444823B2 - Optical disc reproducing apparatus and its calibration method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk reproducing apparatus and a calibration method thereof, and more particularly to an optical disk reproducing apparatus and a calibration method thereof for automatically adjusting a focus control system and a tracking control system before reproducing an optical disk.

[0002]

2. Description of the Related Art A conventional optical disk reproducing apparatus and its outline will be described below with reference to FIGS. FIG. 4 is a diagram for explaining the arrangement of each area on the optical disc.
FIG. 5 is a diagram showing an example of a conventional optical disc reproducing apparatus, FIG.
FIG. 6 is a diagram showing an example of a calibration method of a conventional optical disc reproducing apparatus, which is a diagram showing a flowchart in the case of a recordable MD (mini disc). MDs include a recordable disc shown in FIG. 4A and a premastered disc shown in FIG. The recordable disc is
A pit area in which uneven pits are spirally arranged on the inner circumference, an information track area (also referred to as a groove area or a data area) composed of a spiral guide groove and information marks on the outer side, and an outer circumference A mirror area is provided in which no information mark or guide groove is formed. On the other hand, the pre-mastered disc has a mirror area where information pits are not formed on the outer peripheral portion and an information track area (also referred to as a pit area or data area) where information is formed by concave and convex pits on the inner peripheral portion. ing.

As described above, the optical disc reproduced by the optical disc reproducing apparatus shown in FIG. 5 has spiral information tracks formed of information marks or irregular information pits to be reproduced by utilizing the Kerr effect. . Optical head 11
Then, laser light is emitted from a laser light source (not shown),
This laser light is condensed by an objective lens (not shown) and irradiated on a target position on the disk medium, and information is read from the reflected light from the optical disk. The optical head 11 is composed of an optical system and a drive system. The optical system is
A mechanism for focusing laser light on the disk medium and detecting the deviation between the laser beam spot and the target position on the disk medium. Laser light source, lenses, beam splitter, photodiode (photodetector)
Etc.

The drive system moves the objective lens in the direction normal to the surface of the optical disc so as to control the laser beam to form a beam spot on the surface of the optical disc, and the objective lens in the radial direction of the optical disc. Tracking control is performed by moving the optical spot to follow the track shake and controlling the optical spot to scan on the center line of the information track to determine the positional relationship between the target position on the disk medium and the laser light spot. Is a drive mechanism for maintaining the relationship, and is mainly composed of a magnet, a coil, a support member, an actuator, and the like. In the tracking control, a tracking error signal indicating a tracking error is detected by a known method such as a one-beam push-pull method, a tracking actuator is driven based on the tracking error signal, and the objective lens is parallel to the surface of the disk medium. And in its radial direction. When performing an access operation or the like, the moving means 21 sends a sled (a screw for moving the optical head) in the radial direction of the optical disc, and moves the optical head 11 in the radial direction of the optical disc.

First, the general operation of the optical disk reproducing apparatus shown in FIG. 5 will be briefly described below. The reflected light from the optical disk is incident on the photodetector built in the optical head 11 via the deflection beam splitter built in the optical head 11, is received by the photodetector, is photoelectrically converted, and is supplied to the head amplifier 13 as a signal S3. The head amplifier 13 amplifies and calculates the signal S3. In the calculation, a tracking error signal and a focus error signal are obtained by addition and subtraction of outputs of the four-division photo detector, and addition and subtraction of two signals obtained by dividing the light beam reflected from the optical disc by the deflection beam splitter are performed. . The head amplifier 13 may be built in the optical head 11. The output from the head amplifier 13 is supplied to the buffer means 15. The output S4 of the buffer means 15 is supplied to the demodulation circuit 17, and the reproduction signal is output from the demodulation circuit 17. The demodulation circuit 17 expands the compressed digital information.

On the other hand, necessary ones of the calculation results in the head amplifier 13 are supplied to the focus & tracking control means 23 and the calibration means 35. The focus & tracking control means 23 includes a focus control means and a tracking control means, and a focus error signal obtained by the astigmatism method or the Foucault method is supplied to the focus control means. The objective lens of the optical head 11 is controlled by an actuator (not shown) to move in a direction perpendicular to the surface of the optical disc in accordance with the focus error signal so that a beam spot is formed on the recording surface of the optical disc. .

A tracking error signal generated by a known method such as a one-beam push-pull method is supplied to the tracking control means, and an actuator for moving an objective lens is driven according to the tracking error signal. The optical head or the objective lens in the optical head is moved in the radial direction of the optical disc. The actuator is built in the optical head 11 and is not shown.

First, a recordable MD to be reproduced
When the (mini disk) is mounted on the optical disk reproducing device 40, the rotation control of the reproducing device and the focus pull-in (focus search) of the optical head 11 are performed (step S13), and a microprocessor (hereinafter referred to as MPU).
A signal SC indicating the start of calibration is supplied to the buffer means 15, the moving means 21, the focus & tracking control means 23, and the calibration means 35 from (26). Then, the input to the buffer unit 15 is prohibited, the tracking control is canceled (hereinafter, also referred to as OFF), and the calibration unit 35 starts the calibration of the focus & tracking control unit 23. Hereinafter, the calibration means the automatic adjustment of the focus control means and the tracking control means performed before the reproduction of the optical disc unless otherwise specified.

When the beam spot is applied to the pit area formed in the innermost peripheral portion of the recordable MD in step S15 in step S15, the process proceeds to step S17 in which the thread is moved to the outer peripheral side. Slightly sent to. As a result, the irradiation position of the light beam is slightly changed to the outer peripheral side and enters the groove area. If the groove area is not entered once, steps S15 and S17 are repeated. If it is determined in step S15 that the area other than the pit area is read, the process proceeds to step S19, the tracking control system is adjusted in step S19, and the process proceeds to step S25. In the adjustment of the tracking control system, the offset (balance) adjustment of the tracking error signal is performed in the tracking OFF state, and then in the tracking ON state, the loop gain of the tracking control system is automatically adjusted to a predetermined value. It In step S25, it is determined whether the characteristic or set value of the tracking control system after the gain adjustment in step S19 is within a predetermined range (determination 1).
The characteristic of the tracking control system is an open loop gain characteristic, an open loop phase characteristic, a closed loop gain characteristic, a zero cross frequency, etc. of the tracking control system, and the set value is after automatic adjustment at a check point in the tracking control system. Voltage, etc.

When it is judged in the judgment 1 that the characteristic or set value of the tracking control system is not within the predetermined range,
Returning to step S19, step S19 and step S25
Is repeated. When it is determined in step S25 that the characteristic or set value of the tracking control system is within the predetermined range, the process proceeds to step S21. In step S21, offset adjustment and gain adjustment of the focus control system are performed, and the flow advances to step S27. In step S27, it is determined whether or not the characteristic or set value of the focus control system is within a predetermined range (determination 2). If it is not within the predetermined range, the process returns to step S21, and steps S21 and S27.
Is repeated. When it is determined in the determination 2 that the characteristic or set value of the focus control system is within the predetermined range, the process proceeds to step S23, and in step S23, adjustments other than the focus control system and the tracking control system are performed.

Focus and tracking control means 2
The calibration of No. 3 is performed every time the disc is replaced in order to suppress a control error caused by variations in the reflectance of the optical disc, the inclination of the optical disc, and the like. When the calibration is completed, M
The signal SC indicating the end of calibration from the PU 26 is the buffer means 1
5, the moving means 21, the focus & tracking control means 23, and the calibration means 35 are supplied, and the calibration is completed.

[0012]

In the conventional optical disc reproducing apparatus, in the automatic adjustment of the focus control system and the tracking control system performed immediately after mounting the optical disc, if the optical disc reproducing apparatus is provided with a switch called a start limit switch. First, the optical head is moved to the innermost peripheral portion, and the optical head is slightly moved from the position to the outer peripheral side of the optical disk, and the calibration (automatic adjustment) is performed in a state where the light beam is scanning the data area. Is done. The start limit switch is for limiting the moving range of the optical head so as not to go too far to the inner peripheral side when the optical head is moved to the innermost peripheral part.

However, the installation of the start limit switch may be omitted in order to downsize the device or reduce the manufacturing cost. In an optical disc reproducing apparatus which does not have the start limit switch and further does not have a scale for measuring the position of the optical head, the focus & tracking control apparatus is calibrated by the conventional method as shown in FIG. . In the conventional calibration method, when the calibration is started, the automatic adjustment of the optical disk reproducing device fails because it is not known which area on the optical disk the light beam spot from the optical head irradiates. was there.

Specifically, in the conventional calibration method, the calibration of the focus control system and the tracking control system is performed as shown in FIG.
In the recordable disc shown in (A), the groove area <data area> must be performed, but it is difficult to control the position of the optical head so that the light beam surely scans the data area during calibration. . Hereinafter, this point will be described in detail. When starting the calibration, the optical head is first made sufficiently large (2 m) toward the outer peripheral side in order to avoid the risk of calibration in the pit area.
(m to 5 mm), when the position of the optical head before the movement is close to the mirror area, the area irradiated by the light beam (hereinafter also referred to as a scanning area) enters the mirror area, or the optical head is moved. Collides with the outer periphery, and a tooth skipping sound is generated from the thread feeding mechanism. On the contrary, when the calibration is started, if the optical head is moved to the inner circumference sufficiently large (about 5 mm) in order to avoid the risk of calibration in the mirror area, the optical head before the movement is moved. When the position is close to the pit area, the area irradiated by the light beam (scanning area) enters the pit area, or the optical head collides with the inner circumference, and a tooth skipping sound is generated from the thread feeding mechanism. It will be.

However, as described above, it is difficult to control the position of the optical head so that the scanning area surely becomes the data area. Therefore, conventionally, in the pit area, the method shown in FIG. 6 is used. I tried to avoid the automatic adjustment, but if I try to calibrate the tracking control system when the light beam spot is illuminating the mirror area at the outermost periphery of the optical disc, Steps S19 and S25 shown are repeated, and the automatic adjustment of the tracking control system is forcibly proceeded to step S21 in the uncompleted state, or step S2
The calibration operation may be forcibly terminated without proceeding to 1. The present invention has been made in view of the above problems, and an object thereof is an optical disc reproducing apparatus and a calibration method thereof which can surely perform automatic adjustment of a focus control system and a tracking control system without including a start limit switch. Is to provide.

[0016]

The present invention has been made in view of the above problems, and the first invention is a rewritable data area having a mirror area where information is not recorded and a circular guide groove. And an optical head for reading information from the optical disc, in which a pit area having concave and convex information pits is formed in this order from the outer peripheral side to the inner peripheral side, and a moving means for moving the optical head in the radial direction of the optical disc. When,
Focus control means for performing focus control of the optical head, tracking control means for performing tracking control of the optical head, and the optical head for determining whether or not a light beam emitted from the optical head irradiates a pit area of an optical disc. In the optical disc reproducing apparatus, the optical disc reproducing device is provided with a region determining unit that determines the output of the optical disc and a calibrating unit that automatically adjusts the focus control unit and the tracking control unit before reproducing the optical disc. The head is sent to the inner circumference side of the optical disc to perform focus pull-in, and then the area determination means makes the determination, and as a result of the determination, the optical head is used when the light beam irradiates the pit area. Is sent to the outer peripheral side of the optical disk using the moving means, and then the In the optical disc reproducing device, the area determination means makes the determination, and when the light beam irradiates the area other than the pit area, the calibration means adjusts the gains of the focus control means and the tracking control means. is there.

In the present invention, in the calibration before reproducing the optical disk, the optical head is first moved to the inner peripheral side in order to avoid the optical head from scanning the mirror area.
This movement amount is set to such an extent that the mirror area can be sufficiently avoided and not too large. After performing the focus pull-in, the area determination means determines whether or not the area currently scanned by the optical head (scan area) is a pit area. At this time, the scanning area is a data area or a pit area, but if it is determined that the scanning area is a data area, the calibration means adjusts the gains of the tracking control system and the focus control system. Further, if it is determined that the scanning area is a pit area, the optical head is sent to the outer peripheral side to avoid the pit area, and it is again determined whether the scanning area is the pit area. The movement of the optical head toward the outer peripheral side is repeated until it is determined that the scanning area is the data area. Then, when the scanning area becomes the data area, the above-mentioned gain adjustment of the tracking control system and the focus control system is performed.

According to the present invention, the optical head is first forcibly moved in the inner peripheral direction of the optical disk, and the optical head is reliably prevented from scanning the mirror area. The amount of movement is set to a value that is necessary and sufficient for surely avoiding the mirror area, and even if the optical head hits the inner circumference side, the mechanical noise at that time can be set to a level that does not pose a problem. Next, after it is confirmed that the optical head is scanning the data area, the tracking control system and the focus control system are automatically adjusted. The tracking control system can be automatically adjusted.

According to a second aspect of the invention, a mirror area in which no information is recorded, a rewritable data area having a circular guide groove, and a pit area having uneven information pits are provided.
An optical head for reading information from an optical disk formed in this order from the outer peripheral side to the inner peripheral side, a moving means for moving the optical head in the radial direction of the optical disk, and a focus control means for controlling focus of the optical head. And tracking control means for performing tracking control of the optical head, and area determination means for determining whether or not the light beam emitted from the optical head irradiates the pit area of the optical disc according to the output of the optical head. And a calibration method for an optical disk reproducing apparatus, comprising: a calibration means for automatically adjusting the focus control means and the tracking control means before reproducing the optical disk,
After the optical disc to be reproduced is mounted on the optical disc reproducing device, the optical head is sent to the inner peripheral side of the optical disc to perform focus pull-in, and then the region determination means makes the determination, and as a result of the determination, When the light beam irradiates the pit area, the optical head is sent to the outer peripheral side of the optical disk, and then the area determination unit makes the judgment again, and the light beam irradiates the area other than the pit area. In this case, it is a method of calibrating the optical disk reproducing device, which is adapted to adjust the gains of the focus control means and the tracking control means.

According to a third aspect of the present invention, a mirror area in which no information is recorded, a rewritable data area having a circular guide groove, and a pit area having uneven information pits are provided.
An optical head for reading information from an optical disk formed in this order from the outer peripheral side to the inner peripheral side, a moving means for moving the optical head in the radial direction of the optical disk, and a focus control means for controlling the focus of the optical head. ,
Tracking control means for performing tracking control of the optical head; area determining means for determining whether or not the light beam emitted from the optical head is illuminating a mirror area of the optical disk according to the output of the optical head; In an optical disc reproducing apparatus including a focus control unit and a calibration unit that automatically adjusts the tracking control unit before reproducing the optical disc, in the automatic adjustment, the optical head is sent to the outer peripheral side of the optical disc for focus pull-in. After that, the area determination means performs the determination, and as a result of the determination, when the light beam irradiates the mirror area, the optical head is moved to the inner circumference side of the optical disk by using the moving means. After sending the light, the area determination means makes the determination again, and the light beam is not in the mirror area. If you are irradiated is an optical disk reproducing apparatus that adjusts the gain of the focus control means and the tracking control means by said calibration means.

In the present invention, in the calibration before reproducing the optical disk, in order to avoid the optical head from scanning the pit area, the optical head is first moved to the outer peripheral side.
This movement amount is set to a size that can sufficiently avoid the pit area. After performing the focus pull-in, the area determination means determines whether or not the area currently scanned by the optical head (scan area) is a mirror area. At this time, the scanning region is a data region or a mirror region, but if it is determined that the scanning region is a data region, the calibration means adjusts the gains of the tracking control system and the focus control system. Further, if it is determined that the scanning area is the mirror area, the optical head is sent to the inner circumference side to avoid the mirror area, and it is again determined whether the scanning area is the mirror area. The movement of the optical head toward the inner circumference side is repeated until the scanning area is determined to be the data area, and when the scanning area becomes the data area, the gain adjustment of the tracking control system and the focus control system is performed. Be seen. According to the present invention, the optical head is first forcibly moved in the outer peripheral direction of the optical disc, and the optical head is reliably prevented from scanning the pit area. Then, the movement amount is set to a value that is necessary and sufficient for surely avoiding the pit area, and even if the optical head hits the outer peripheral side, the mechanical sound at that time can be set to a level that does not pose a problem. Then, after it is confirmed that the optical head is scanning the data area, the tracking control system and the focus control system are automatically adjusted, so that it is possible to reliably perform tracking even in an optical disc reproducing apparatus that does not have a start limit switch. It is possible to automatically adjust the control system.

According to a fourth aspect of the present invention, a mirror area in which no information is recorded, a rewritable data area having a circular guide groove, and a pit area having uneven information pits are provided.
An optical head for reading information from an optical disk formed in this order from the outer peripheral side to the inner peripheral side, a moving means for moving the optical head in the radial direction of the optical disk, and a focus control means for controlling the focus of the optical head. ,
Tracking control means for performing tracking control of the optical head; area determining means for determining whether or not the light beam emitted from the optical head is illuminating a mirror area of the optical disk according to the output of the optical head; A method for calibrating an optical disk reproducing apparatus comprising a focus controlling means and a calibrating means for automatically adjusting the tracking controlling means before reproducing the optical disk, wherein after the optical disk to be reproduced is mounted on the optical disk reproducing apparatus, The head is sent to the outer peripheral side of the optical disc to perform focus pull-in, and then the area determination unit makes the determination. As a result of the determination, when the light beam irradiates the mirror area, the optical head is turned on. After sending to the inner circumference side of the optical disc, the area determination means performs the determination again, If the climate beam is irradiated with the non-mirror area is a calibration method for an optical disk reproducing apparatus that adjusts the gain of the focus control means and the tracking control means.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION
It is an optical disk reproducing apparatus that does not necessarily have a start limit switch and is capable of reliably performing automatic adjustment (calibration) of a tracking control system and a focus control system. In the present invention, in the automatic adjustment, the gain adjustment of the tracking control system and the gain adjustment of the focus control system are performed while the optical head is scanning the data area of the optical disc.

For this reason, when starting the calibration, first the optical head is slightly moved to the inner or outer circumference side, and then the
Focus pull-in is performed, and then, it is determined whether or not the scanning region irradiated with the light beam is the data region. If it is determined that the scanning area is the data area in the determination, the gain adjustment of the tracking control system and the gain adjustment of the focus control system are performed as they are. If it is determined that the scanning area is not the data area, the optical head is used. Is again moved in the radial direction, and the determination as to whether the scanning area is the data area is performed again. The movement of the optical head is repeated until the scanning area becomes the data area, and after the optical head comes to scan the data area, the automatic adjustment is performed.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. FIG. 1 is a block diagram showing a first embodiment of the optical disc reproducing apparatus of the present invention, and FIG. 2 is a flow chart of the first embodiment of the calibration method of the present invention, which is a recordable MD (mini disc).
It is a figure which shows the flowchart in the case of. In FIG. 1, elements having the same functions and functions as those in FIG. 5 are designated by the same reference numerals, and description thereof may be omitted. Also, in FIG.
3, steps corresponding to those in FIG. 6 are denoted by the same reference numerals, and description thereof may be omitted.

The optical disk reproducing apparatus 10 shown in FIG. 1 and FIG.
The main difference from the optical disk reproducing apparatus 40 shown in FIG. 1 is that the reproducing apparatus shown in FIG. 1 is provided with the area determination means 19, and the main difference between the flowchart shown in FIG. 2 and the flowchart shown in FIG. In FIG. 2, there is a step of first sending the optical head to the inner peripheral side. In FIGS. 1 and 2, first, a recordable M to be reproduced.
When D (mini disk) is mounted on the optical disk reproducing apparatus 10, a signal SC indicating the start of calibration is supplied from the MPU 25 to the buffer means 15, the moving means 21, the focus & tracking control means 23, and the calibrating means 31. MPU2
Based on a command from 5, the rotation control means (not shown) controls the rotation of the optical disk, and the movement means 2
The optical head 11 is moved to the inner circumference side of the optical disk by 1 (step S11). It is difficult to accurately control this movement amount, and in order to reliably avoid a mirror area having a large variation in width, the target movement amount is set to a value slightly larger than the width of the mirror area. The width of the mirror area is 1.5 mm (16.0-14.
5) Often larger than.

After the movement of the optical head, focus pull-in (focus search) of the optical head 11 is performed by the focus control means (step S1).
3). Then, the input to the buffer means 15 is prohibited, the tracking control is canceled (OFF), and step S
Proceed to 15. In step S15, a plurality of signals output from the head amplifier 13 are used to determine whether the position (scanning area) on the optical disk surface where the beam spot is currently irradiated is a pit area in which uneven information pits are formed. The area determination means 19 makes a determination based on S5.
Specifically, the reflected light from the optical disk is split into I light and J light by the deflecting beam splitter, but the amplitude of the RF signal generated from the signal corresponding to the sum of the I light and J light is large. If it is small, it is determined to be a pit area, and if it is small, it is determined to be a data area.

If it is determined in step S15 that the scan area is the pit area formed on the inner peripheral portion of the recordable MD, the process proceeds to step S17. In step S17, the sled of the moving means 21 is slightly sent to the outer peripheral side. As a result, the irradiation position of the light beam is slightly changed to the outer peripheral side and enters the groove area.
If it does not enter the groove area once, step S
15 and step S17 are repeated.

When it is determined in step S15 that the area other than the pit area is read, the process proceeds to step S19, the tracking control system is adjusted in step S19, and the process proceeds to step S21. In the adjustment of the tracking control system, the offset (balance) adjustment of the tracking error signal is performed in the tracking OFF state, and then in the tracking ON state, the loop gain of the tracking control system is automatically adjusted to a predetermined value. It In step S21, offset adjustment and gain adjustment of the focus control system are performed, and the flow advances to step S23. The step S23
Then, automatic adjustment of, for example, a tilt control system other than the focus control means and the tracking control means is performed as necessary.

Focus and tracking control means 2
The calibration of No. 3 is performed every time the disc is replaced in order to suppress a control error caused by variations in the reflectance of the optical disc, the inclination of the optical disc, and the like. When the calibration is completed, M
The signal SC indicating the end of calibration from the PU 25 is the buffer means 1
5, the moving means 21, the focus & tracking control means 23, and the calibration means 35 are supplied, and the calibration is completed. In the first embodiment, the optical head 11 is moved to the inner peripheral side of the optical disc in step S11 at the beginning of the calibration so that the scanning region is surely deviated from the mirror region. by this,
The optical head is adapted to scan the data area or the pit area. Further, although there is a possibility that the optical head may collide with the inner peripheral side due to the movement, the biasing amount for the movement is limited. It can be suppressed to the extent that it does not become.

Next, a second embodiment of the optical disk reproducing apparatus of the present invention will be described with reference to FIGS. A block diagram showing a second embodiment of the optical disc reproducing apparatus of the present invention is the same as FIG. 1 as the first embodiment. FIG. 3 is a diagram showing a flow chart of the calibration method of the second embodiment.
It is a figure which shows the flowchart in case of D (mini disk). The area arrangement of the recordable MD is as shown in FIG. The flowchart shown in FIG. 3 differs from the flowchart shown in FIG. 2 in steps S12, S16, and S18.

In FIGS. 1 and 3, first, when the recordable MD (mini disk) to be reproduced is mounted on the optical disk reproducing apparatus 10, the microprocessor 25
From the above, a signal SC indicating the start of calibration is supplied to the buffer means 15, the moving means 21, the focus & tracking control means 23, and the calibration means 31. Based on a command from the MPU 25, the rotation control means (not shown) controls the rotation of the optical disk, and the moving means 21 moves the optical head 11 to the outer peripheral side of the optical disk (step S).
12). It is difficult to accurately control this movement amount, and the target movement amount is set to a value slightly larger than the width of the pit area in order to reliably avoid the pit area. In the example shown in FIG. 4, the width of the pit area is 1.5 mm (16.0-14.
5), and the target movement amount is set to a value slightly larger than this.

After the movement of the optical head, focus pull-in (focus search) of the optical head 11 is performed by the focus control means (step S1).
3). Then, the input to the buffer means 15 is prohibited, the tracking control is canceled (OFF), and step S1 is performed.
Go to 6. In step S16, it is determined whether the position (scanning area) on the optical disk surface where the beam spot is currently irradiated is the mirror area on the outer peripheral portion of the optical disk.
The area determination means 19 makes a determination based on the plurality of signals S5 output from the head amplifier 13. Specifically, the tracking control is turned off, and the amplitude of the tracking error signal (in this case, the track crossing signal) is detected. If the amplitude is smaller than a predetermined value, it is determined that the light beam is scanning the mirror area. Otherwise, it is determined that the light beam is scanning the data area.

If it is determined in step S16 that the scanning area is the mirror area formed on the outer peripheral portion of the recordable MD, step S18 is performed.
Proceed to. In step S18, the sled of the moving means 21 is slightly sent to the inner peripheral side. As a result, the irradiation position of the light beam is slightly changed to the inner peripheral side and enters the groove area. If the groove area is not entered once, steps S16 and S18 are repeated. The steps S16 and S18 are repeated until a track crossing signal having an amplitude of a predetermined value or more is detected in step S16. In this way, in step S16, the area determining means 19 determines where the area on the optical disc being scanned is.

When it is determined in step S16 that the scanning area is the data area, the process proceeds to step S19, the gain and offset voltage of the tracking control system are adjusted, and then the process proceeds to step S21, where the gain and offset of the focus control system are adjusted. The voltage is adjusted. After step S21, the process further proceeds to step S23, adjustments other than the tracking control system and the focus control system are performed as necessary, and the calibration is completed. When the calibration is finished,
A signal SC indicating the end of calibration is supplied from the MPU 25 to the buffer unit 15, the moving unit 21, the focus & tracking control unit 23, and the calibration unit 35, and the calibration is completed.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of an optical disc reproducing apparatus of the present invention.

FIG. 2 is a diagram showing a flowchart of a first embodiment of the calibration method of the present invention.

FIG. 3 is a diagram showing a flowchart of a second embodiment of the calibration method of the present invention.

FIG. 4 is a diagram illustrating the arrangement of areas on an optical disc.

FIG. 5 is a diagram showing an example of a conventional optical disc reproducing apparatus.

FIG. 6 is a diagram showing an example of a calibration method of a conventional optical disc reproducing apparatus.

[Explanation of symbols]

11 Optical head 13 head amplifier 21 Means of transportation 23 Focus & Tracking Control Means 25 MPU 31 Calibration means S11 Send optical head to inner side S13 Focus search (focus pull-in) S15 Is the reading in the pit area? S16 Is reading in the mirror area? S17 Send the optical head to the outer circumference S18 Send optical head to inner circumference S19 Tracking control system gain adjustment S21 Gain adjustment of focus control system

Claims (4)

(57) [Claims] 1. A mirror area in which no information is recorded, a rewritable data area having a circular guide groove, and a pit area having uneven information pits are arranged in this order from the outer peripheral side to the inner peripheral side. An optical head for reading information from an optical disk formed toward the optical disk, a moving means for moving the optical head in a radial direction of the optical disk, a focus control means for controlling focus of the optical head, and a tracking control for the optical head. Tracking control means, area determination means for determining whether the light beam emitted from the optical head irradiates the pit area of the optical disc according to the output of the optical head, and the focus control before reproducing the optical disc. In an optical disc reproducing apparatus provided with a control means and a calibration means for automatically adjusting the tracking control means. Then, in the automatic adjustment, the optical head is sent to the inner circumference side of the optical disc to perform focus pull-in, and then the determination is made by the area determination means. As a result of the determination, the light beam irradiates the pit area. If the optical head is sent to the outer peripheral side of the optical disk by using the moving means, then the area determination means makes the determination again, and the light beam irradiates other than the pit area. The optical disk reproducing apparatus is characterized in that the calibration means adjusts the gain of the focus control means and the tracking control means. 2. A mirror area in which no information is recorded, a rewritable data area having a circular guide groove, and a pit area having uneven information pits are arranged in this order from the outer peripheral side to the inner peripheral side. An optical head for reading information from the optical disc formed toward the optical disc, a moving unit for moving the optical head in the radial direction of the optical disc, a focus control unit for controlling the focus of the optical head, and a tracking control for the optical head. Tracking control means for performing, area determination means for determining whether or not the light beam emitted from the optical head irradiates the pit area of the optical disc according to the output of the optical head, and before reproducing the optical disc Optical disk reproduction provided with the focus control means and a calibration means for automatically adjusting the tracking control means In the calibration method of the device, after the optical disc to be reproduced is mounted on the optical disc reproducing device, the optical head is sent to the inner peripheral side of the optical disc to perform focus pull-in, and then the determination is performed by the area determination unit, As a result of the determination, if the light beam is irradiating the pit area, the optical head is sent to the outer peripheral side of the optical disk, and then the area determination means makes the determination again, and the light beam is emitted in the pit area. A method for calibrating an optical disk reproducing device, characterized in that the gain of the focus control means and the tracking control means is adjusted when other than the above is irradiated. 3. A mirror area in which no information is recorded, a rewritable data area having a circular guide groove, and a pit area having uneven information pits are arranged in this order from the outer peripheral side to the inner peripheral side. An optical head for reading information from an optical disk formed toward the optical disk, a moving means for moving the optical head in a radial direction of the optical disk, a focus control means for controlling focus of the optical head, and a tracking control for the optical head. Tracking control means, area determination means for determining whether a light beam emitted from the optical head is illuminating a mirror area of the optical disk according to the output of the optical head, and the focus control before reproducing the optical disk. In an optical disc reproducing apparatus provided with a control means and a calibration means for automatically adjusting the tracking control means. Then, in the automatic adjustment, the optical head is sent to the outer peripheral side of the optical disc to perform focus pull-in, and then the area determination unit makes the determination, and as a result of the determination, the light beam irradiates the mirror area. If the optical head is sent to the inner circumference side of the optical disk by using the moving means, the area determination means makes the determination again, and when the light beam irradiates other than the mirror area, Is an optical disk reproducing apparatus, wherein the calibration means adjusts the gain of the focus control means and the tracking control means. 4. A mirror area in which no information is recorded, a rewritable data area having a circular guide groove, and a pit area having uneven information pits are arranged in this order from the outer peripheral side to the inner peripheral side. An optical head for reading information from an optical disk formed toward the optical disk, a moving means for moving the optical head in a radial direction of the optical disk, a focus control means for controlling focus of the optical head, and a tracking control for the optical head. Tracking control means, area determination means for determining whether a light beam emitted from the optical head is illuminating a mirror area of the optical disk according to the output of the optical head, and the focus control before reproducing the optical disk. A comparison of an optical disc reproducing apparatus provided with a control means and a calibration means for automatically adjusting the tracking control means. In the method, after the optical disc to be reproduced is mounted on the optical disc reproducing device, the optical head is sent to the outer peripheral side of the optical disc to perform focus pull-in, and then the determination is performed by the area determination means, and the result of the determination When the light beam is irradiating the mirror area, the optical head is sent to the inner circumference side of the optical disc, and then the area determination unit makes the determination again, and the light beam irradiates the area other than the mirror area. If so, a method of calibrating the optical disk reproducing apparatus is characterized in that the gain of the focus control means and the tracking control means is adjusted.