JP2005166191A - Tilt control method for optical disk recording and reproducing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tilt control method for an optical disk recording and reproducing apparatus capable of recording a signal on a disk with the use of an optical pickup. <P>SOLUTION: The tilt control method for the optical disk recording and reproducing apparatus performs tilt control in such a manner that after a signal for offset adjustment is recorded in a trial writing area and an offset value setting area arranged and set near the outer peripheral side of a position at which the completing of recording is predetermined while changing the level of a driving signal for detecting offset which is supplied to a coil for tilt adjustment, the reproducing operation of the recorded signal for offset adjustment is performed and peak levels of a reproduced RF signal are detected and when a signal with which a peak level to be detected from the signal becomes the maximum is recorded, the level of the driving signal which is supplied to the coil for tilt adjustment is set as an inner peripheral side offset value and an outer peripheral side offset value and offset values corresponding to recording positions which are calculated from the inner peripheral side offset value and the outer peripheral offset value are added to a tilt adjusting signal which performs tilt control. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tilt control method for an optical disc recording / reproducing apparatus configured to record a signal on a disc by a laser beam irradiated from an optical pickup and perform a reproducing operation of the signal recorded on the disc by the laser beam. .

  Disc players that use an optical pickup to read signals recorded on a disc are widely used. In addition to the playback function, a signal can be recorded on the disc by a laser beam emitted from the optical pickup. An optical disc recording / reproducing apparatus configured so as to be able to be made has been commercialized.

  In the optical disc recording / reproducing apparatus, since it is necessary to accurately irradiate the signal track of the disc with the laser beam emitted from the optical pickup, the focus control operation and the tracking control operation are performed. Such a focus control operation is performed by supplying a drive current to a focusing coil that displaces the objective lens in the disk surface direction, and a tracking control operation is performed by applying a drive current to the tracking coil that displaces the objective lens in the radial direction of the disk. This is done by supplying.

  Recently, the recording density has been increased in order to record many signals on the disk. In order to perform a high-density recording operation, it is necessary to irradiate the disk surface with laser light in an optimum state. In order to perform such an operation, not only the above-described focus control operation and tracking control operation are accurately performed, but also an operation for correcting a relative angular deviation between the disc and the objective lens, that is, a tilt control operation is performed. An optical pickup configured to be able to be developed has been developed (for example, see Patent Document 1).

  A technique for detecting the inclination of the optical pickup with respect to the disk and adjusting the inclination has been developed (see, for example, Patent Document 2).

Some optical disc recording / reproducing apparatuses use a rewritable disc that can perform a recording / erasing operation not only once but also a recording / erasing operation.
JP 2002-197698 A JP 2001-52362 A

  The technology described in Patent Document 2 is configured to provide a tilt sensor that detects the tilt of the optical pickup with respect to the disk, and to perform a tilt adjustment operation based on a signal obtained from the tilt sensor. According to such a technique, although an accurate tilt adjustment control operation can be performed, the tilt sensor is expensive, and there is a problem that the optical disc recording / reproducing apparatus is expensive.

In addition, the tilt adjustment coil incorporated in the optical pickup is fixed to a support member that supports the objective lens. Since there is a change over time, the tilt angle is not constant when the drive voltage is not supplied to the tilt adjustment coil. Therefore, there is a problem that accurate tilt adjustment is not performed when the tilt adjustment operation is performed in such a state.

  The present invention is intended to provide a tilt control method for an optical disc recording / reproducing apparatus capable of solving such a problem.

  According to the first aspect of the present invention, after the offset adjustment signal is recorded while changing the level of the drive signal for offset detection supplied to the tilt adjustment coil in the test writing area provided on the inner peripheral side of the disc. The drive supplied to the tilt adjustment coil when the recorded offset adjustment signal is reproduced, the peak level of the reproduced RF signal is detected, and the signal with the maximum detected peak level is recorded Set the signal level as the inner circumference offset value, and further recognize the scheduled recording end position from the signal recordable area of the signal recording area provided on the disc and the recording capacity of the recording signal output from the host device, For offset detection to be supplied to the tilt adjustment coil in the offset value setting area that is set near the outer periphery of the recognized scheduled recording end position. After the offset adjustment signal is recorded while changing the level of the moving signal, the recorded offset adjustment signal is reproduced, the peak level of the reproduced RF signal is detected, and the detected peak level is the maximum. The level of the drive signal supplied to the tilt adjustment coil when the signal is recorded is set as the outer peripheral offset value, and the tilt adjustment signal for tilt control is calculated from the inner peripheral offset value and the outer peripheral offset value. Tilt control is performed by adding an offset value corresponding to the recording position.

  According to the second aspect of the present invention, after the offset adjustment signal is recorded while changing the level of the drive signal for offset detection supplied to the tilt adjustment coil in the test writing area provided on the inner circumference side of the disc. Drive that is supplied to the tilt adjustment coil when the recorded offset adjustment signal is reproduced, the bottom level of the reproduced RF signal is detected, and the signal that minimizes the detected bottom level is recorded Set the signal level as the inner circumference offset value, and further recognize the scheduled recording end position from the signal recordable area of the signal recording area provided on the disc and the recording capacity of the recording signal output from the host device, For offset detection to be supplied to the tilt adjustment coil in the offset value setting area that is set near the outer periphery of the recognized scheduled recording end position. After the offset adjustment signal is recorded while changing the level of the moving signal, the recorded offset adjustment signal is reproduced, the bottom level of the reproduced RF signal is detected, and the detected bottom level is minimized. The level of the drive signal supplied to the tilt adjustment coil when the signal is recorded is set as the outer peripheral offset value, and the tilt adjustment signal for tilt control is calculated from the inner peripheral offset value and the outer peripheral offset value. Tilt control is performed by adding an offset value corresponding to the recording position.

According to the third aspect of the present invention, after the offset adjustment signal is recorded while changing the level of the drive signal for offset detection supplied to the tilt adjustment coil in the test writing area provided on the inner peripheral side of the disc. When the recorded offset adjustment signal is reproduced, the peak level and the bottom level of the reproduced RF signal are detected, and the signal that maximizes the difference between the detected peak level and the bottom level is recorded. The level of the drive signal supplied to the tilt adjustment coil is set as the inner peripheral offset value, and the signal recordable area of the signal recording area provided on the disk and the recording capacity of the recording signal output from the host device To adjust the tilt to the offset value setting area that is set near the outer periphery of the estimated recording end position. The offset adjustment signal is recorded while changing the level of the offset detection drive signal supplied to the coil, and then the recorded offset adjustment signal is played back to detect the peak level and bottom level of the reproduced RF signal. Then, when recording a signal that maximizes the difference between the detected peak level and bottom level, the level of the drive signal supplied to the tilt adjustment coil is set as the outer offset value to perform tilt control. Tilt control is performed by adding an offset value corresponding to a recording position calculated from the inner peripheral offset value and the outer peripheral offset value to the adjustment signal.

  The present invention records the offset adjustment after recording the offset adjustment signal while changing the level of the drive signal for offset detection supplied to the tilt adjustment coil in the test writing area provided on the inner circumference side of the disc. Signal is reproduced, the peak level or bottom level of the reproduced RF signal is detected, the signal having the maximum detected peak level, the signal having the lowest bottom level, or the peak level and the bottom level Set the level of the drive signal supplied to the coil for tilt adjustment when recording the signal that maximizes the difference as the inner peripheral offset value, and further the signal recordable area of the signal recording area provided on the disc and the host Recognize the expected recording end position from the recording capacity of the recording signal output from the device, and near the recognized recording end position on the outer circumference side The offset adjustment signal is recorded while changing the level of the drive signal for offset detection supplied to the tilt adjustment coil in the offset value setting area to be arranged, and then the recorded offset adjustment signal is reproduced and reproduced. The peak level or bottom level of the detected RF signal was detected, and the signal with the maximum detected peak level, the signal with the minimum bottom level, or the signal with the maximum difference between the peak level and the bottom level was recorded. Sometimes the level of the drive signal supplied to the coil for tilt adjustment is set as the outer offset value, and the tilt adjustment signal for tilt control corresponds to the recording position calculated from the inner offset value and the outer offset value. Since the tilt control is performed by adding the offset value, the tilt adjustment coil Ri attached position deviation can be accurate tilt adjustment without being influenced by temperature change and aging.

  In particular, the present invention calculates an offset value corresponding to a recording position using an offset value set in an offset value setting area set near the inner circumference side of the disc and the outer circumference side of the scheduled recording end position. Since the offset adjustment is performed by setting, the tilt adjustment operation suitable for the area where the signal is actually recorded can be accurately performed.

  The present invention records the offset adjustment signal at each position by changing the angle of the optical pickup with respect to the disc in the test writing area provided on the inner circumference side of the disc and the signal recording area of the disc. It is something that is set.

  FIG. 1 is a circuit diagram showing an embodiment of an optical disc recording / reproducing apparatus according to the present invention, FIG. 2 is a signal waveform diagram for explaining the operation of the present invention, and FIG. 3 is a plan view showing a disc according to the present invention. .

  In FIG. 1, reference numeral 1 denotes a disk that is placed on a turntable (not shown) that is rotationally driven by a spindle motor (not shown) and that can repeatedly perform a signal rewrite operation, as shown in FIG. Further, there are provided a test writing area A, a PMA area B indicating the recorded contents of the disc, and a signal recording area C used when adjusting the laser output from the inner circumference side. The test writing area A is an area used when adjusting the recording laser output before performing the recording operation of the data signal in the signal recording area C, and a laser output adjusting method using such an area is well known. Therefore, the description thereof is omitted.

Further, position information data indicating the position on the disk is recorded on the disk 1 by meandering grooves called pregrooves, and the optical disk recording / reproducing apparatus records signals based on the wobble signal obtained from the grooves. It is configured to perform a reproduction operation and a signal recording position recognition operation. Reference numeral 2 denotes a laser diode 3 that emits laser light emitted to the disk 1 and a monitor diode (not shown) that monitors the amount of laser light emitted from the laser diode 3. An optical pickup incorporating a photodetector 4 that receives laser light reflected from the signal surface, and is configured to be moved in the radial direction of the disk 1 by a pickup feed motor (not shown). .

  Further, in the optical pickup 2, a focusing coil 5 for displacing an objective lens (not shown) in the surface direction of the disc 1, a tracking coil 6 for displacing the objective lens in the radial direction of the disc 1, and a disc of the objective lens. A tilt adjusting coil 7 for adjusting an angle with respect to 1 is incorporated.

  Reference numeral 8 denotes a focusing control operation for focusing the laser light emitted from the laser diode on the signal surface of the disk 1 based on the signal obtained from the photodetector 4 incorporated in the optical pickup 2, and the laser light as a signal. A pickup control circuit that performs a tracking control operation to follow a signal track on a surface, and is configured to output a tracking control signal based on a tracking error signal and a focusing control signal based on a focus error signal.

  Reference numeral 9 denotes a tracking coil driving circuit to which a tracking control signal output from the pickup control circuit 8 is input, and is configured to supply a driving signal to the tracking coil 6 incorporated in the optical pickup 2. . Reference numeral 10 denotes a focusing coil driving circuit to which a focusing control signal output from the pickup control circuit 8 is input, and is configured to supply a driving signal to the focusing coil 5 incorporated in the optical pickup 2. .

  Reference numeral 11 denotes an RF signal amplification circuit that receives an RF signal obtained from the photodetector 4 incorporated in the optical pickup 2 and amplifies the signal, and outputs an RF signal having the waveform shown in FIG. A binarized signal is output. Reference numeral 12 denotes a peak level detection circuit to which an RF signal output from the RF signal amplification circuit 11 is input, and is configured to detect the level indicated by the upper solid line P in the waveform diagram shown in FIG. Has been. Reference numeral 13 denotes a bottom level detection circuit to which an RF signal output from the RF signal amplification circuit 11 is input, and is configured to detect a level indicated by a lower solid line Q, that is, a bottom level in the waveform diagram shown in FIG. Has been.

  14 is a signal detected and output by the peak level detection circuit 12 and the bottom level detection circuit 13, that is, a peak level and a bottom level value obtained from the RF signal are input and output from the focusing coil drive circuit 10. A tilt control circuit for performing a tilt control operation based on a tilt adjustment signal obtained from the drive signal, and a tilt coil drive circuit whose operation is controlled by a signal output from the tilt control circuit. A tilt adjustment drive signal is supplied to a tilt adjustment coil 7 incorporated in the optical pickup 2.

Reference numeral 16 denotes an offset detection circuit that is in an operation state during an offset value detection operation performed before the recording operation. The tilt control circuit 14 tilts the tilt coil drive circuit 15 stepwise, that is, the objective lens with respect to the disk 1 is moved. A signal for causing the tilt adjustment coil 7 to output a drive signal for offset detection for changing the tilt is output. Reference numeral 17 denotes a memory circuit for storing an offset value detected by an offset value detection operation, which will be described later, and is added to a tilt adjustment signal obtained from the focusing coil drive circuit 10 when performing a tilt control operation in the recording / reproducing operation state. The offset signal is sent to the memory circuit 1
The tilt control circuit 14 is configured to generate the offset value based on the offset value stored in FIG.

  Reference numeral 18 denotes a laser drive circuit for supplying a drive signal to the laser diode 3 incorporated in the optical pickup 2. Reference numeral 19 denotes an encode process for recording a recording signal on the disk 1 and supplies the signal to the laser drive circuit 18. The signal recording circuit is configured to output an offset adjustment signal during the offset value detection operation.

  Reference numeral 20 denotes a digital signal processing circuit which receives the binarized signal output from the RF signal amplifier circuit 11 and performs various signal extraction operations. Reference numeral 21 denotes a computer device which is a host device to which an optical disk recording / reproducing apparatus is connected, and is configured to output various command signals and output recording signals to the optical disk recording / reproducing apparatus. Reference numeral 22 denotes a system control circuit for transmitting and receiving various signals to and from the computer device 21, and is configured to control operations of the offset detection circuit 16, the signal recording circuit 19, the digital signal processing circuit 20, and the like. Has been.

  As described above, the optical disk recording / reproducing apparatus according to the present invention is configured. Next, the operation will be described. Various operations of the optical disc recording / reproducing apparatus are performed based on a command signal output from the computer device 21. In the state where a normal recording operation and a reproducing operation are performed, the operation is incorporated in the optical pickup 2. A focus error signal and a tracking error signal are generated from a signal obtained from the photodetector 4, and a control operation for performing a focusing control operation and a tracking control operation based on the generated error signal is performed by the pickup control circuit 8. .

  When each control operation by the pickup control circuit 8 is performed, a control signal is output from the pickup control circuit 8 to the focusing coil drive circuit 10 and the tracking coil drive circuit 9. As a result, a driving signal is supplied from the focusing coil driving circuit 10 and the tracking coil driving circuit 9 to the focusing coil 5 and the tracking coil 6. Such a drive signal displaces the objective lens in a direction to reduce the level of the focus error signal or tracking error signal, so that focusing control for focusing the laser light emitted from the optical pickup 2 on the signal surface on the disk 1 It is possible to perform a tracking control operation that follows the operation and the signal track.

  As described above, the focusing control operation and tracking control operation by the pickup control circuit 8 are performed. Next, the tilt control method which is the gist of the present invention will be described.

  In the optical disc recording / reproducing apparatus according to the present invention, an offset value setting operation necessary for accurately performing the tilt control operation is performed before performing the recording operation. In the operation for such setting, a signal for performing an operation for setting an offset value from the offset detection circuit 16 to the tilt control circuit 14 is output.

  Such an operation is a control operation in which a control signal for changing the tilt angle step by step is output from the tilt coil driving circuit 15 to the tilt adjusting coil 7 step by step in a state where the normal tilt control operation is not performed. Is done. When such a control signal is output from the tilt control circuit 14, the tilt of the objective lens from the tilt coil driving circuit 15 to the tilt adjusting coil 7 is stepped from the position where the objective lens is most inclined to the other direction. A drive signal for offset detection for changing is supplied. As a result, the objective lens is tilted step by step in the direction of tilt adjustment by the drive operation of the tilt adjustment coil 7.

  During the offset value detection operation, as described above, the operation of changing the tilt of the objective lens step by step by the signal output from the offset detection circuit 16 is performed. This operation is performed on the inner circumference side of the disc 1. This is performed while recording an offset adjustment signal in the provided test writing area A.

  First, a case where an offset adjustment signal is recorded in the test writing area A in order to set the inner peripheral offset value will be described. The operation of outputting an offset adjustment signal from the signal recording circuit 19 to the laser driving circuit 18 and recording the signal in the test writing area A on the inner circumference side of the disk 1 by the laser light emitted from the laser diode 7 is tilted. This is done while changing the angle step by step. When such an offset adjustment signal recording operation is performed, the relationship between the recording position and the level of the signal output from the offset detection circuit 16 is stored in the memory circuit 17 or the like.

  When the objective lens tilt changing operation based on the signal output from the offset detection circuit 16 is completed, the recording operation of the offset adjustment signal on the disk 1 is also stopped. When such an operation is completed, the optical pickup 2 is moved to the position where the recording operation of the offset adjustment signal in the test writing area A is started, and then the recorded offset adjustment signal is reproduced. Such a reproduction operation is performed in a state where a drive signal is not supplied to the tilt adjustment coil 7, that is, in a state where the objective lens is in a neutral position.

  When the recorded offset adjustment signal is reproduced while changing the angle of the objective lens with respect to the disk 1, the level of the RF signal obtained from the laser light reflected from the disk 1 changes. The offset adjustment signal recorded in the trial writing area A of the disk 1 is amplified by the RF signal amplification circuit 11 and then input to the peak level detection circuit 12 and the bottom level detection circuit 13.

  As the inclination of the optical pickup 2 with respect to the signal surface of the disk 1 is adjusted in the correct direction, the peak level in the RF signal increases and the bottom level decreases on the contrary. Therefore, when the recorded offset adjustment signal is changed while the tilt is changed stepwise, the peak level decreases after reaching the maximum and the bottom level increases after reaching the minimum.

  When the recorded offset adjustment signal is reproduced while stepwise changing the level of the drive signal supplied to the tilt adjustment coil 7, the peak level and the bottom level of the RF signal as the reproduction signal change. Will do. When the drive voltage at the position where the offset adjustment signal at which the peak level is maximized is recorded or the position at which the offset adjustment signal at which the bottom level is minimized is recorded is supplied to the tilt adjustment coil 7, tilt is performed. An operation of storing the value of the control signal output from the control circuit 14 in the memory circuit 17 as the inner peripheral offset value is performed.

  The setting operation of the inner periphery side offset value described above is a case of utilizing the characteristic that the peak level of the RF signal is maximized or the bottom level is minimized. You can also use the difference. That is, when a signal recorded with the objective lens tilt optimally on the signal surface of the disk 1 is reproduced, there is a characteristic that the difference between the peak level and the bottom level becomes the largest, so this difference becomes the largest. When the drive voltage at the position where the offset adjustment signal is recorded is supplied to the tilt adjustment coil 7, the value of the control signal output from the tilt control circuit 14 is stored in the memory circuit 17 as the inner peripheral offset value. Operation is performed.

As described above, the setting operation of the inner circumferential offset value using the test writing area A is performed. In the present invention, the outer circumferential offset value is set using the signal recording area C provided on the disc 1. Setting operation is performed. Such an operation is performed using an area where no signal is recorded when the recording signal output from the computer device 21 is recorded in the signal recording area, that is, the signal recording remaining area.

  From the information recorded in the PMA area B provided on the disc 1, the usage status of the signal recording area C provided on the disc 1, that is, the recording position of the signal recorded in the signal recording area C, the recordable area Since the recordable capacity and the like can be recognized, the computer device 21 performs an operation of comparing the capacity of the recording signal with the signal recordable area of the signal recording area C. By performing such a comparison operation, it is determined whether or not the recording operation of the recording signal can be performed on the disk 1. If it is determined that the recording operation cannot be performed, the disk should be replaced. Such a notification operation is performed.

  When it is determined that the signal recording area is in the signal recording area by the comparison operation described above, from which position the area where the signal is not recorded is generated when the signal recording operation is performed. The calculation operation is performed. Such an operation can be calculated from the signal recordable area of the disc 1, the signal recording start position, and the recording capacity of the recording signal.

  In FIG. 3, an area indicated by C1 in the signal recording area C is a signal recording scheduled area where a recording signal transmitted from the computer device 21 is actually recorded, and an area C2 is a signal recording remaining area. An area indicated by oblique lines C3 is an offset value setting area arranged and set on the outer periphery side of the signal recording scheduled area C1, and in the vicinity of the outer periphery side of the scheduled recording end position which is the outermost peripheral position of the signal recording scheduled area C1. Placement is set.

  After the optical pickup 2 is moved to the inner peripheral side position of the offset value setting area C3 based on the position information data recorded as the wobble signal on the disk 1, the offset value detecting operation in the test writing area A described above is performed. Since the operation for setting the outer peripheral offset value can be performed by performing the same operation, the description thereof is omitted. The outer peripheral offset value set in the offset value setting area C3 of the signal recording area C is stored in the memory circuit 17.

  As described above, the inner peripheral offset value and the outer peripheral offset value are stored in the memory circuit 17. Next, the tilt adjustment operation will be described.

  When the optical disk recording / reproducing apparatus is in a reproduction state or a recording state, when the relationship between the optical pickup 2 and the disk 1 needs to be adjusted in tilt, the tilt adjustment coil 7 is used to change the tilt of the objective lens. The drive signal supplied from the tilt coil drive circuit 15 is used to adjust the tilt adjustment signal for changing the tilt by using the drive signal supplied from the focusing coil drive circuit 10 to the focusing coil 5. Is called.

  The drive signal supplied to the focusing coil 5 from the focusing coil drive circuit 10 is a signal in which an AC signal is superimposed on a DC voltage. That is, the DC voltage is a signal for displacing the position of the objective lens to the operating position, and the AC signal is a signal for displacing the objective lens by following the fast movement of the disk 1. The DC voltage described above is a signal for displacing the objective lens to the operating position in accordance with the positional relationship between the signal surface of the disk 1 and the optical pickup 2, and tilt adjustment is performed by utilizing the change in the DC voltage. I can do it.

That is, since the DC voltage included in the drive signal supplied to the focusing coil 5 indicates the positional relationship between the objective lens and the signal surface of the disk 1, the DC voltage that changes corresponding to the position change on the disk. Indicates the tilt relationship between the objective lens and the disk 1. Accordingly, a change in the DC voltage included in the drive signal supplied from the focusing coil drive circuit 10 to the focusing coil 5 is extracted as a tilt adjustment signal, and the extracted signal is stored in the memory circuit 17. The tilt adjustment operation can be performed by supplying the tilt coil driving circuit 15 with a signal obtained by adding the offset value calculated from the peripheral offset value and the offset value calculated as the peripheral offset value as a tilt control signal.

  The offset value added to the signal extracted from the focusing coil drive circuit 10 is calculated and set according to the recording position from the inner peripheral offset value and the outer peripheral offset value. That is, the position on the offset value setting area C3 in the signal recording remaining area C2 in which the outer peripheral side offset value is set and the position on the test writing area A in which the inner peripheral side offset value is set are obtained from the position information data. Therefore, the optimum offset value at the signal recording position on the disk 1 can be calculated from the distance between them and the change in the offset value.

  As a result of the tilt adjustment operation described above, the tilt coil drive circuit 15 supplies the tilt adjustment drive signal with the optimum tilt adjustment to the recording / reproducing position to the tilt adjustment coil 7. An operation for adjusting the angle to an optimum state, that is, a tilt adjustment operation can be accurately performed.

  In addition, since the disc in the present invention is a disc that can repeatedly perform the recording operation, the offset value setting area C3 that is arranged and set for setting the outer peripheral offset value is set to be shifted from the signal recording area. However, since the signal recording operation is not adversely affected, there is a feature that the setting position of the offset value setting area C3 does not need to be strict.

  In this embodiment, a signal for tilt adjustment is obtained from the drive signal supplied to the focusing coil 5, but it is used for an apparatus configured to perform tilt adjustment using the level change of the RF signal. You can also do it.

It is a circuit diagram which shows one Example of the optical disk recording / reproducing apparatus based on this invention. It is a signal waveform diagram for demonstrating operation | movement of this invention. It is a top view which shows the disk based on this invention.

Explanation of symbols

1 disc
2 Optical pickup
3 Laser diode
4 photodetectors
5 Focusing coil
6 Tracking coil
7 Coil for tilt adjustment
DESCRIPTION OF SYMBOLS 8 Pickup control circuit 10 Focusing coil drive circuit 11 RF signal amplification circuit 12 Peak level detection circuit 13 Bottom level detection circuit 14 Tilt control circuit 15 Tilt coil drive circuit 16 Offset detection circuit 17 Memory circuit 18 Laser drive circuit 19 Signal recording circuit 20 Digital signal processing circuit 21 Computer device 22 System control circuit

Claims (3)

A tilt control method for an optical disc recording / reproducing apparatus that uses an optical pickup having a tilt adjustment coil for adjusting the tilt of an objective lens and can record a signal on a rewritable disc. Record the offset adjustment signal while changing the level of the drive signal for offset detection supplied to the tilt adjustment coil in the provided test writing area, and then play back the recorded offset adjustment signal. The peak level of the RF signal to be detected is detected, the level of the drive signal supplied to the coil for tilt adjustment when the signal with the maximum detected peak level is recorded is set as the inner peripheral offset value, and the disc Of the signal recordable area of the signal recording area and recording of the recording signal output from the host device The recording end scheduled position is recognized from the amount, and the level of the drive signal for offset detection supplied to the tilt adjustment coil is changed to the offset value setting area set near the outer periphery of the recognized scheduled recording end position. When the offset adjustment signal is recorded and the recorded offset adjustment signal is reproduced, the peak level of the reproduced RF signal is detected, and the signal with the maximum detected peak level is recorded The level of the drive signal supplied to the tilt adjustment coil is set as the outer peripheral offset value, and the tilt adjustment signal for performing the tilt control corresponds to the recording position calculated from the inner peripheral offset value and the outer peripheral offset value. Tilt control is performed by adding an offset value, and the tilt control of the optical disk recording / reproducing apparatus is characterized in that Method. A tilt control method for an optical disc recording / reproducing apparatus that uses an optical pickup having a tilt adjustment coil for adjusting the tilt of an objective lens and can record a signal on a rewritable disc. Record the offset adjustment signal while changing the level of the drive signal for offset detection supplied to the tilt adjustment coil in the provided test writing area, and then play back the recorded offset adjustment signal. The level of the drive signal supplied to the tilt adjustment coil when a signal that minimizes the detected bottom level is recorded is set as the inner peripheral offset value. Of the signal recording area provided in the signal recording area and recording of the recording signal output from the host device The recording end position is recognized from the amount, and the level of the drive signal for offset detection supplied to the tilt adjustment coil is changed to the offset value setting area that is set near the outer periphery of the recognized recording end position. When the offset adjustment signal is recorded and then the recorded offset adjustment signal is reproduced, the bottom level of the reproduced RF signal is detected, and the signal that minimizes the detected bottom level is recorded The level of the drive signal supplied to the tilt adjustment coil is set as the outer peripheral offset value, and the tilt adjustment signal for performing the tilt control corresponds to the recording position calculated from the inner peripheral offset value and the outer peripheral offset value. Tilt control is performed by adding an offset value to the optical disc recording / reproducing apparatus. Method. A tilt control method for an optical disc recording / reproducing apparatus that uses an optical pickup having a tilt adjustment coil for adjusting the tilt of an objective lens and can record a signal on a rewritable disc. Record the offset adjustment signal while changing the level of the drive signal for offset detection supplied to the tilt adjustment coil in the provided test writing area, and then play back the recorded offset adjustment signal. The peak level and bottom level of the RF signal to be detected are detected, and the level of the drive signal supplied to the coil for tilt adjustment when the signal with the maximum difference between the detected peak level and bottom level is recorded Set as the side offset value, and the signal recordable area of the signal recording area provided on the disc The recording end scheduled position is recognized from the recording capacity of the recording signal output from the recording device, and the tilt adjustment coil is supplied to the offset value setting area arranged near the outer periphery of the recognized recording end position. After recording the offset adjustment signal while changing the level of the drive signal for detecting the offset, the recorded offset adjustment signal is reproduced, and the peak level and bottom level of the reproduced RF signal are detected and detected. The level of the drive signal supplied to the coil for tilt adjustment when a signal that maximizes the difference between the peak level and the bottom level is recorded is set as the outer offset value, and the tilt adjustment signal for tilt control is set as the tilt adjustment signal. By adding the offset value corresponding to the recording position calculated from the inner circumference offset value and the outer circumference offset value, Tilt control method for optical disc recording and reproducing apparatus being characterized in that to perform the door control.

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