JP2007095126A - Optical dusk device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical disk device having a function capable of performing a proper tilt adjustment even when a radial warp in an optical disk is changing by variation of temperature with time. <P>SOLUTION: When executing a spin up after the optical disk is loaded, a tilt adjusting means moves an optical pickup to a predetermined inner periphery adjusting position and a predetermined outer periphery adjusting position of the optical disk, respectively, to acquire optimum tilt angles at the inner periphery adjusting position and the outer periphery adjusting position, and performs tilt adjustment, based on these angles. A tilt re-adjusting means performs readjustment of the tilt after performing the spin-up when a predetermine time has elapsed after reproduction or recording are started (or when temperature measured by a temperature sensor reaches a predetermined temperature after the reproduction or recording are started). Thus, jitter is improved, and the performance of reproduction and recording are improved. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to an optical disc apparatus that reproduces information recorded on an optical disc or records / reproduces information to / from an optical disc, and more particularly to a tilt adjustment process for adjusting a tilt of an optical pickup.

Conventionally, in an optical disk apparatus, laser light from an optical pickup is focused on a light spot having a diameter of, for example, about 0.5 μm by an objective lens, and information is recorded on a track having a pitch of, for example, about 0.74 μm. Recording or reproducing information recorded on a track. At this time, if the optical axis of the laser beam irradiated on the optical disk surface is not perpendicular to the optical disk surface and has a relative tilt error, the light spot is also irradiated on the adjacent track, and information on the adjacent track is mixed. At the same time, aberration occurs in the light spot on the optical disk surface, and the recording quality and reproduction quality are greatly reduced.

Such an inconvenience becomes a very big problem in an optical disc apparatus provided with an optical pickup having a large numerical aperture of an objective lens in order to realize high density. Therefore, it is important to suppress the tilt error of the optical axis of the laser beam with respect to the optical disk surface to a predetermined angle or less. Therefore, tilt control for controlling the tilt of the optical pickup according to the warp of the optical disk is performed to correct the tilt error. Necessary.

Conventionally, in an optical disc apparatus, when an optical disc is inserted, the optical disc is rotated for a short time to start up, laser light is emitted from an optical pickup, disc information is read,
Spin-up, which is a process until the optical pickup is set to the initial position, is started. At the time of spin-up after the start of the spin-up, the tilt adjustment of the optical pickup is performed by the tilt adjustment means. That is, the tilt adjustment means moves the optical pickup to a predetermined inner circumference adjustment position and a predetermined outer circumference adjustment position of the optical disc, and performs tilt adjustment at two points, an inner circumference adjustment position and an outer circumference adjustment position.
JP-A-10-177729 JP 2003-263964 A JP 2004-95184 A

By the way, although the optical disk depends on the resin material, the warp may change in the radial direction of the recording surface due to a change in temperature. When such an optical disc is inserted into the optical disc apparatus and reproduction processing or recording processing is performed, the internal circuit elements of the optical disc apparatus generate more heat as time elapses, which increases the temperature inside the apparatus. As a result, the warp in the radial direction of the optical disk changes.

However, in the conventional optical disc apparatus, the optical pickup tilt adjustment is performed in a low temperature state (a short time after the apparatus is turned on and the temperature inside the apparatus is still low). Tilt control is performed up to the outermost circumference of the optical disc at a tilt angle, so that when the optical disc rises in temperature and the warpage changes with time, appropriate tilt adjustment can be performed. As a result, during reproduction, the RF signal from the optical pickup is attenuated, the S / N is reduced due to the influence of noise, and the amount of jitter in the reproduction signal processing system increases, thereby reducing the reproduction performance. At the time of recording, the accuracy of the tracking error signal (TE signal) from the optical pickup is reduced, and the amount of jitter in the recording signal processing system is increased. Ability there is a problem of a decrease.

In the prior art of Patent Document 1, a drive signal for the focus actuator is taken out and converted into an amount of displacement of the optical disc, an inclination distribution of the optical disc is calculated from a differential of the distribution of the amount of displacement, and stored in a memory. During reproduction, the tilt of the optical disk at the position corresponding to the output of the radial position detection means of the optical head (optical pickup) is read from the memory, and the tilt mechanism is driven according to the tilt of the optical disk to adjust the tilt of the optical head. However, if the optical disc is warped in the radial direction due to a temperature change with the passage of time, proper tilt adjustment cannot be performed, and thus the above-described problems cannot be solved. .

In the prior art of Patent Document 2, the tilt angle control circuit calculates the disc radius from the disc information and performs tilt adjustment in the vicinity of this position, with the tilt angle adjustment value stored in advance in the flash memory as the center. By adjusting the tilt angle, the adjustment time can be shortened and the operation can be stabilized. However, this conventional technique is also performed by changing the radial warpage of the optical disk due to the temperature change with time. In such a case, appropriate tilt adjustment cannot be performed, and thus the above-described problem cannot be solved.

In the prior art of Patent Document 3, the defocus amount when the level of the tracking error signal is maximized at many positions on the inner and outer circumferences of the disk in the state of being operated only by focus control, the tilt direction at this time, and The size is detected and the tilt is adjusted, and the adjusted value is stored in the map state, and the tilt and focus control is performed using the value recorded at the corresponding position during actual recording / playback. This prior art also cannot solve the above-mentioned problems because the tilt adjustment cannot be performed properly when the radial warpage of the optical disk changes due to a temperature change with time.

The present invention has been made to solve the above-described problems, and is a function that enables appropriate tilt adjustment even when the radial warpage of the optical disk changes due to a temperature change with time. It is an object to provide an optical disc device having

In order to achieve the above object, according to the first aspect of the present invention, after the optical disk is loaded, the optical disk is started up, and the optical pickup is performed at the time of executing the spin-up that is a process until the optical pickup is set to the initial position. Tilt adjustment is performed by moving the optical disc to a predetermined inner circumference adjustment position and a predetermined outer circumference adjustment position, obtaining the optimum tilt angle at the inner circumference adjustment position and the outer circumference adjustment position, and performing tilt adjustment based on the tilt angle. Means, and after performing the spin-up,
A re-tilt adjustment means for performing a re-tilt adjustment when a predetermined time has elapsed since the start of reproduction or recording, or when the temperature measured by the temperature sensor has reached a predetermined temperature since the start of reproduction or recording; In order to confirm the optimum tilt angle to be acquired, the current tilt angle setting value is changed by ± predetermined amount, and the tilt adjustment is performed so that the amplitude of the RF signal is maximized for the recorded area of the optical disc. Tilt adjustment is performed so that the amplitude of the tracking error signal is maximized for an unrecorded area of the optical disc, and a tilt angle setting means for setting an optimum tilt angle, and when the tilt adjustment is performed at a low temperature state Position address storage means for storing the address of the outer periphery adjustment position of the optical disk in the memory, and tilt adjustment at the outer periphery adjustment position indicated by the address read from the memory Thus, it has a tilt control means for calculating a disc warpage amount at the radial position by a first order approximation, setting a tilt angle based on the disc warpage amount, and performing a tilt control. And a system controller having a tilt adjustment control unit that performs the tilt adjustment when reading the reproduction data and controls the tilt adjustment when the recording data is read from the recording buffer memory during recording. An optical disc apparatus is provided.

In this configuration, when the optical disc is inserted, the spin-up is started and the tilt adjustment of the optical pickup is performed by the tilt adjusting means at the time of spin-up. That is, the tilt adjustment means moves the optical pickup to a predetermined inner circumference adjustment position and a predetermined outer circumference adjustment position of the optical disc, and obtains an optimum tilt angle between the inner circumference adjustment position and the outer circumference adjustment position, thereby adjusting the tilt. I do.

After performing such tilt adjustment on the optical pickup, the reproduction operation is started, information is reproduced from the optical disc, and when a predetermined time has elapsed or when a predetermined temperature is reached, the re-tilt adjustment means Then, an optimum tilt angle is obtained at the adjustment inner circumference position and the outer circumference adjustment position of the optical disc, and the re-tilt adjustment is performed.

The re-tilt adjustment at the time of reproduction is performed by the tilt adjustment control means when the reproduction data is read from the reproduction buffer memory. That is, the re-tilt adjustment is performed when the optical pickup is not reading information from the optical disc. Therefore, apparently, the reproduction process and the re-tilt adjustment process are executed in parallel, and there is no influence on the reproduction operation.

In addition, when the recording operation is started, information is recorded on the optical disc, and when the predetermined time has elapsed or when the temperature measured by the temperature sensor reaches the predetermined temperature, the re-tilt adjusting means Re-tilt adjustment is performed by obtaining optimum tilt angles at the adjustment inner circumference position and the outer circumference adjustment position. The re-tilt adjustment at the time of recording is performed by the tilt adjustment control means when the recording data is read from the recording buffer memory. That is, the re-tilt adjustment is performed when the optical pickup is not writing information on the optical disc. Therefore, apparently, the recording process and the re-tilt adjustment process are executed in parallel, and there is no influence on the recording operation.

For details of the re-tilt adjustment process, the tilt angle adjustment process is started in order to confirm the optimum tilt angle obtained by the tilt adjustment unit, and the recorded area of the optical disc is subjected to the RF signal at the time of reproduction. An optimum tilt angle is set by adjusting the tilt of the optical pickup so that the amplitude becomes maximum, and the tilt of the optical pickup is corrected by the set tilt angle.

In the reproduction process or recording process when there is an unrecorded area of the optical disc (reproduction process when there is an unrecorded area when reproducing an optical disk with recorded information, recording process for an unrecorded optical disk without recorded information), The tilt angle setting means adjusts the tilt of the optical pickup so as to set the optimum tilt angle so that the amplitude of the tracking error signal is maximized.

Then, the position address storage means stores the address of the outer peripheral adjustment position of the optical disc in the memory when the tilt adjustment is performed in a low temperature state (a short time after the device is turned on and the temperature in the device is still low). save. Therefore, the tilt control means performs tilt adjustment at the outer periphery adjustment position indicated by the address read from the memory, roughly calculates the warpage of the optical disk by primary approximation, calculates the disk warpage amount at the radial position, and uses this disk warpage amount. Based on this, the tilt angle is set, and tilt control for the optical pickup is performed.

According to this configuration, even when the radial warpage of the optical disk changes due to a temperature change with the passage of time, when the predetermined time elapses or when the temperature measured by the temperature sensor reaches the predetermined temperature, Since the re-tilt adjustment of the pickup is performed, it is possible to perform an appropriate tilt adjustment even if the radial warpage of the optical disk changes, thereby reducing the attenuation of the RF signal from the optical pickup during reproduction. This prevents the S / N degradation and improves the playback signal processing system jitter, thereby improving the playback performance. Also, during recording, the accuracy of the tracking error signal from the optical pickup is improved. The recording performance can be improved by preventing the deterioration of the recording signal and improving the jitter of the recording signal processing system.

According to the second aspect of the present invention, when the optical pickup is started up after the optical disc is loaded and the optical pickup is set to the initial position, when the spin-up is executed, the optical pickup is set at a predetermined inner circumference adjustment position of the optical disc. And a tilt adjusting means for obtaining an optimum tilt angle at the inner circumference adjustment position and the outer circumference adjustment position and adjusting the tilt based on the tilt angle, and executing the spin-up. And a re-tilt adjustment means for performing a re-tilt adjustment when a predetermined time has elapsed since the start of reproduction or recording, or when the temperature measured by the temperature sensor has reached a predetermined temperature since the start of reproduction or recording. Provided is an optical disc device comprising a system controller.

In this configuration, when the spin-up is performed after the optical disk is loaded, the tilt adjustment means moves the optical pickup to the predetermined inner circumference adjustment position and the predetermined outer circumference adjustment position of the optical disc, respectively, so that the inner circumference adjustment position and the outer circumference adjustment position are moved. The optimum tilt angle at the adjustment position is acquired, and tilt adjustment is performed based on this tilt angle. The re-tilt adjustment means, when the predetermined time has elapsed since the start of reproduction or recording after the execution of the spin-up, or when the temperature measured by the temperature sensor has reached a predetermined temperature after the start of reproduction or recording, Perform re-tilt adjustment.

According to this configuration, even when the radial warpage of the optical disk changes due to a temperature change with the passage of time, when the predetermined time elapses or when the temperature measured by the temperature sensor reaches the predetermined temperature, Since the re-tilt adjustment of the pickup is performed, it is possible to perform an appropriate tilt adjustment even if the radial warpage of the optical disk changes, thereby reducing the attenuation of the RF signal from the optical pickup during reproduction. This prevents the S / N degradation and improves the playback signal processing system jitter, thereby improving the playback performance. Also, during recording, the accuracy of the tracking error signal from the optical pickup is improved. The recording performance can be improved by preventing the deterioration of the recording signal and improving the jitter of the recording signal processing system.

In the invention of claim 3, in the invention of claim 2, the system controller changes the set value of the current tilt angle by ± predetermined amount to confirm the optimum tilt of the acquired tilt angle, and the recorded optical disc is recorded. Tilt adjustment to maximize the RF signal amplitude for the region
Tilt angle setting means for setting the optimum tilt angle for each unrecorded area of the optical disc so that the amplitude of the tracking error signal is maximized, and the optical disc when the tilt adjustment is performed at a low temperature Position address storing means for storing the address of the outer periphery adjustment position in the memory, and performing a tilt adjustment at the outer periphery adjustment position indicated by the address read from the memory, and calculating the disc warpage amount at the radial position by primary approximation, And a tilt control means for performing tilt control by setting a tilt angle based on the disc warpage amount.

Therefore, the system controller can realize the tilt angle setting process, the position address storing process, and the tilt control process, thereby confirming the optimum tilt, and performing the tilt control with the tilt angle set by the confirmation. It becomes possible.

According to a fourth aspect of the present invention, in the second aspect of the present invention, the system controller performs a tilt adjustment when reproducing data is read from the reproduction buffer memory during reproduction, and reads the recording data from the recording buffer memory during recording. Tilt adjustment control means for controlling to perform tilt adjustment when the vehicle is on.

Therefore, the system controller can realize the tilt adjustment control process, so that the reproduction data reading process and the tilt adjustment process can be apparently performed at the time of reproduction, and the recording data writing process and the tilt can be performed at the time of recording. The adjustment process can be apparently performed in parallel, and there is no effect on the speed of the read process during reproduction or the write process during recording.

As described above, according to the present invention, after the optical disk is loaded, the optical disk is started up, and when the spin-up is performed, which is a process from when the optical pickup is set to the initial position, A tilt adjusting unit that moves to a circumferential adjustment position and a predetermined outer circumference adjustment position, obtains an optimum tilt angle at the inner circumference adjustment position and the outer circumference adjustment position, and performs tilt adjustment based on the tilt angle; and the spin Re-tilt adjustment that performs a re-tilt adjustment when a predetermined time has elapsed after playback or recording has started or when the temperature measured by the temperature sensor has reached a predetermined temperature after playback or recording has started. Means for changing the set value of the current tilt angle by a predetermined amount to confirm the optimum tilt of the acquired tilt angle, Tilt adjustment that maximizes the amplitude of the RF signal for the area and tilt adjustment that maximizes the amplitude of the tracking error signal for the unrecorded area of the optical disc. Tilt angle setting means for setting the position, position address storage means for storing the address of the outer periphery adjustment position of the optical disk when the tilt adjustment is performed in a low temperature state, and tilt adjustment at the outer periphery adjustment position indicated by the address read from the memory And a tilt control means for performing tilt control by calculating a tilt angle based on the disc warp amount by calculating the disc warp amount at the radial position by first-order approximation, and reproducing buffer memory during playback Tilt adjustment is performed when playback data is being read from, and recording data is read from the recording buffer memory during recording. Since the system controller having the tilt adjustment control means for performing the tilt adjustment when the optical disk is in operation, even when the radial warpage of the optical disk changes due to the temperature change with the passage of time, a predetermined time Or when the temperature measured by the temperature sensor reaches the specified temperature,
Even if the optical pickup is re-tilt adjusted and the warp in the radial direction of the optical disk changes, appropriate tilt adjustment can be performed. This prevents the attenuation of the RF signal from the optical pickup during playback. Thus, it is possible to improve the reproduction performance by preventing the S / N deterioration and improving the jitter of the reproduction signal processing system. Also, at the time of recording, the accuracy of the tracking error signal from the optical pickup is lowered. And the jitter of the recording signal processing system is improved, so that the recording performance can be improved.

Further, according to the present invention, after the optical disk is loaded, the optical disk is started up, and the optical pickup is adjusted to a predetermined inner circumference of the optical disk at the time of performing spin-up, which is a process until the optical pickup is set to the initial position. A tilt adjusting means for obtaining an optimum tilt angle at the inner circumference adjustment position and the outer circumference adjustment position, and performing a tilt adjustment based on the tilt angle; A re-tilt adjustment means for performing a re-tilt adjustment when a predetermined time has elapsed since the start of reproduction or recording after execution, or when the temperature measured by the temperature sensor has reached a predetermined temperature after the start of reproduction or recording; When the optical disk warpage in the radial direction changes due to temperature changes over time. However, when the predetermined time has elapsed or when the temperature measured by the temperature sensor reaches the predetermined temperature, the optical pickup is re-tilt adjusted, and even if the optical disc is warped in the radial direction, the appropriate tilt adjustment is performed. As a result, during playback, the RF signal from the optical pickup is prevented from being attenuated, the S / N is prevented from being lowered, and the jitter of the playback signal processing system is improved, thereby improving the playback performance. Can also be
At the time of recording, it prevents the accuracy of the tracking error signal from the optical pickup from being reduced,
The recording performance can be improved by improving the jitter of the recording signal processing system.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing a configuration of an optical disc apparatus according to the first embodiment of the present invention. Here, DVD
Although the configuration of an optical disk device such as a recorder will be described, it goes without saying that the tilt adjustment process described below can also be applied to an optical disk device such as a DVD player during reproduction.

This optical disk apparatus includes a system controller 22 that controls the entire apparatus, a spindle motor 5 that rotates the optical disk 1, an optical pickup 2 that optically writes / reads information to / from the optical disk 1, and the optical pickup 2. The sled 3 for moving the optical disc 1 in the radial direction and the spindle motor 5 and the sled 3 are driven via the motor drive circuit 34 in accordance with an instruction from the system controller 22, and the objective incorporated in the optical pickup 2. A servo control unit that performs control to move the focal position of the laser beam in the vertical and horizontal directions with respect to the recording surface of the optical disc 1 by moving a lens (not shown), and performs tilt control of the optical pickup 2. 4 is provided.

The optical disc apparatus also includes an RF amplifier 6 that amplifies an RF signal that is a read signal from the optical pickup 2 during reproduction of the optical disc 1, and an optical disc 1 that converts the RF signal output from the RF amplifier 6 into digital data. The digital signal processing unit 8 stores data generated by performing signal demodulation processing and error correction processing according to the data format in the RAM 7 as a reproduction buffer memory, and the digital signal processing unit 8 according to an instruction from the system controller 22 Is provided with a stream separation unit 9 that separates audio data, sub-picture data, and video data from the data stream output from.

The optical disc apparatus also stores an audio decoder 11 that receives the audio data output from the stream separator 9 and performs a predetermined decoding process, and temporarily stores the data to perform the decoding process in the audio decoder 11. The RAM 10, the sub-picture decoder 13 that inputs the sub-picture data output from the stream separation unit 9 and performs a predetermined decoding process, and temporarily stores the data to perform the decoding process by the sub-picture decoder 13 The video MP which performs the decoding process by MPEG (Moving Picture Experts Group) by inputting the video data output from the RAM 12 and the stream separation unit 9
An EG decoder 15 and a RAM 14 for temporarily storing data for decoding by the video MPEG decoder 15 are provided.

In addition, the optical disc apparatus is adapted to video MPE according to instructions from the system controller 22.
A video processor 17 that synthesizes the data output from the G decoder 15 and the data output from the sub-picture decoder 13, and converts the synthesized data output from the video processor 17 into a display video signal to display an image. A video encoder 18 to be displayed on the apparatus 20 and a D / A converter 16 that converts data output from the audio decoder 11 into an analog audio signal and supplies the analog audio signal to, for example, a speaker 19 are provided.

The optical disc apparatus also has various operations such as a recording key for giving a recording instruction to the system controller 22, a reproducing key for giving a reproducing instruction, a stop key for giving a recording / reproducing stop instruction, and a power key. And a remote controller 21 having a key. In addition, this optical disk apparatus has a flash ROM 23 in which programs and data for controlling each component of the apparatus and for controlling the entire apparatus are stored, and a system that performs arithmetic processing according to the programs and data in the flash ROM 23 CPU for controlling the controller 22
24 and a RAM 27 for temporarily storing data necessary for the arithmetic processing of the CPU 24.

The optical disk apparatus also includes a tuner 29 connected to the antenna 28, an analog video / audio signal of a television broadcast selected by the tuner 29, or a television receiver or other video / audio output device (not shown). A / D conversion circuit 30 for converting the video / audio signal into digital video / audio data, and the video / audio data as MPEG (Moving Picture E).
an MPEG encoder 31 that encodes with the xperts group), a RAM 32 as a recording buffer memory that temporarily stores a predetermined amount of the encoded video / audio data (hereinafter referred to as encoded data), and a recording data modulation circuit 25. An ATAPI (AT Attachment Packet Interface) 33 that is an interface, a recording data modulation circuit 25 that modulates the encoded data sent from the ATAPI 33 to record it on the optical disc 1, and a data modulated by the recording data modulation circuit 25 A laser modulation signal for modulating the laser beam emitted from the optical pickup 2 based on the modulation data is transmitted to the optical pickup 2.
And a laser modulation circuit 26 for outputting the signal.

The system controller 22 is a component that characterizes the present embodiment.
After the optical disk 1 is loaded, the optical disk 1 is started up and the optical pickup 2 is moved to the predetermined inner circumference adjustment position and the predetermined outer circumference at the time of executing the spin-up that is a process until the optical pickup 2 is set to the initial position. Each is moved to the adjustment position, the optimum tilt angle at the inner circumference adjustment position and the outer circumference adjustment position is obtained, and the tilt adjustment means 221 for performing the tilt adjustment based on the tilt angle, and the reproduction after the spin-up is executed Alternatively, a re-tilt adjustment unit 222 that performs re-tilt adjustment when a predetermined time has elapsed since the start of recording is included.

In addition, the system controller 22 changes the set value of the current tilt angle by a predetermined amount for confirming the optimum tilt angle of the acquired tilt angle, and applies R to the recorded area of the optical disc 1.
Tilt adjustment that maximizes the amplitude of the F signal and tilt adjustment that maximizes the amplitude of the tracking error signal for the unrecorded area of the optical disc 1, respectively. Angle setting means 223, position address storage means 224 for storing the address of the outer peripheral adjustment position of the optical disk when the tilt adjustment is performed in a low temperature state in the RAM 27,
Tilt adjustment is performed at the outer periphery adjustment position indicated by the address read from the RAM 27, and the disc warpage amount at the radial position is calculated by primary approximation, and the tilt angle is set based on the disc warpage amount to perform tilt control. Tilt control means 225.

In addition, the system controller 22 uses a RAM as a reproduction buffer memory during reproduction.
7 has a tilt adjustment control means 226 for performing a tilt adjustment when reading the reproduction data from 7, and controlling the tilt adjustment when reading the recording data from the RAM 32 as a recording buffer memory during recording.

FIG. 2 is a graph showing the relationship between the passage of time and the tilt angle for the optical disc A in which the tilt changes greatly with the passage of time in the present embodiment. In FIG. 2, L0 is a line showing how the tilt of the optical pickup changes with time when the laser beam of the optical pickup is irradiated on the inner periphery of the optical disc A. L1 is a line showing how the tilt of the optical pickup changes with time when the outer circumference of the optical disc A is irradiated with the laser light of the optical pickup. t0 indicates a time point at which the first tilt adjustment is performed at the time of the first spin-up, and t1 indicates a time point at which the second tilt adjustment is performed when a predetermined time elapses. The predetermined time may be a time elapsed such that the temperature rises and the warp of the optical disk affects the accuracy of tilt control.

FIG. 3 is a graph showing the relationship between the passage of time and the tilt angle for the optical disc B in which the tilt changes greatly with the passage of time in the present embodiment. In FIG. 3, L0 is a line showing how the tilt of the optical pickup changes with time when the inner periphery of the optical disc B is irradiated with the laser light of the optical pickup. L1 is a line showing how the tilt of the optical pickup changes with time when the outer periphery of the optical disc B is irradiated with the laser light of the optical pickup. t0 indicates a time point at which the first tilt adjustment is performed at the time of the first spin-up, and t1 indicates a time point at which the second tilt adjustment is performed when a predetermined time elapses.

FIG. 4 illustrates the relationship between the tilt angle and the amplitude of the RF signal or tracking error signal when acquiring a tilt angle that maximizes the amplitude of the RF signal or tracking error signal when performing tilt adjustment in this embodiment. FIG. In FIG. 4, m1 is the amplitude of the RF signal or tracking error signal when the optical pickup is tilted by a certain amount -e with respect to the tilt angle E, and m2 is the value when the optical pickup is tilted by a certain amount + e with respect to the tilt angle E. The amplitude of the RF signal or tracking error signal, M is the tilt angle E, and indicates the maximum value of the amplitude of the RF signal or tracking error signal.

FIG. 5 is a flowchart for explaining tilt adjustment processing of the optical pickup in the present embodiment. The tilt adjustment process will be described with reference to this flowchart and FIGS.

First, when the optical disk 1 is inserted into the optical disk apparatus (step S1), the system controller 22 starts up by rotating the optical disk 1 for a short time, emits laser light from the optical pickup 2, reads the disk information, and reads the optical information. Spin-up, which is a process until the pickup 2 is set to the initial position, is started (step S2). When the spin-up starts and the spin-up is performed, the tilt of the optical pickup 2 is adjusted. That is, the tilt adjustment means 221 of the system controller 22 controls the servo control unit 4 to move the optical pickup 2 to a predetermined inner circumference adjustment position and a predetermined outer circumference adjustment position of the optical disc 1, respectively. Tilt adjustment is performed by obtaining the optimum tilt angle at the outer periphery adjustment position (step S3).

After such tilt adjustment is performed on the optical pickup 2, the reproduction key of the remote controller 21 is pressed to start a reproduction operation (step S4), information is reproduced from the optical disc 1 (step S5), and reproduction is performed. Is not completed (step S6), and when a predetermined time (for example, 10 minutes) has elapsed (step S9), a tilt adjustment request flag is set in the CPU 24, and in response thereto, the re-tilt adjustment means 222 of the system controller 22 Then, the optimum tilt angles at the adjustment inner peripheral position and the outer peripheral adjustment position of the optical disc 1 are acquired, and the re-tilt adjustment is performed (step S10). Thereafter, the process returns to step S5 and the same process is performed.

The re-tilt adjustment at the time of reproduction is performed by the tilt adjustment control means 226 of the system controller 22 when reproducing data is read from the RAM 7 as a reproduction buffer memory. That is, when the optical pickup 2 is not reading information from the optical disc 1, the re-tilt adjustment of the optical pickup 2 is performed. Therefore, apparently, the reproduction process and the re-tilt adjustment process are executed in parallel, and there is no influence on the reproduction operation.

In step S4, when the recording operation is started by pressing the recording key of the remote controller 21, or when the recording operation is started due to the arrival of the recording start time by the recording reservation (recording reservation), information is recorded on the optical disc 1. Recording is performed (step S7), and recording does not end (
In step S8), when a predetermined time (for example, 10 minutes) has elapsed (step S9), a tilt adjustment request flag is set in the CPU 24, and in response thereto, the re-tilt adjustment means 222 of the system controller 22 adjusts the optical disc 1. Re-tilt adjustment is performed by obtaining the optimum tilt angles at the inner peripheral position and the outer peripheral adjustment position (step S10). Thereafter, the process returns to step S7 and the same process is performed.

The re-tilt adjustment at the time of recording is performed by the tilt adjustment control means 226 of the system controller 22 when recording data is read from the RAM 32 as a recording buffer memory. That is, when the optical pickup 2 is not writing information on the optical disc 1, the servo control unit 4 is controlled, and re-tilt adjustment of the optical pickup 2 is performed. Therefore, apparently, the recording process and the re-tilt adjustment process are executed in parallel, and there is no influence on the recording operation.

FIG. 6 is a flowchart for explaining details of the re-tilt adjustment processing in step S10 shown in FIG. Details of the re-tilt adjustment processing will be described with reference to this flowchart and FIGS.

Tilt angle adjustment processing is started in order to confirm the optimum tilt angle acquired by the tilt adjusting means 221 (step N1), and the recorded area of the optical disc 1 (step N2) is RF for reproduction. The optimum tilt angle is set by adjusting the tilt of the optical pickup 2 so that the amplitude of the RF signal from the amplifier 6 is maximized (step N3). That is, as described in FIG. 4, the tilt angle setting means 223 of the system controller 22 measures the amplitude of the RF signal at a tilt tilted by ± a certain amount from the currently set tilt angle, and the RF signal is maximized. The tilt angle is corrected so that the RF signal is maximized, and the tilt angle when the RF signal is maximized is set as an optimum tilt angle. The tilt control mechanism (not shown) is controlled by the set tilt angle to tilt the optical pickup 2. to correct.

In reproduction processing or recording processing when there is an unrecorded area of the optical disc 1 (reproduction processing when there is an unrecorded area when reproducing an optical disc with recorded information, recording processing for an unrecorded optical disc without recorded information) The tilt angle setting means 223 sets the optimum tilt angle by adjusting the tilt of the optical pickup 2 so that the amplitude of the tracking error signal from the RF amplifier 6 is maximized (step N4).

The position address storage means 224 of the system controller 22 adjusts the outer periphery of the optical disc 1 when the tilt adjustment is performed in a low temperature state (a state in which the temperature inside the device is still low after the device is turned on). The address of the position is stored in the RAM 27 (step N5). Therefore, the tilt control means 225 of the system controller 22 performs tilt adjustment at the outer periphery adjustment position indicated by the address read from the RAM 27, and roughly calculates the warpage of the optical disc 1 by linear approximation, and calculates the disc warpage amount at the radial position. Then, the tilt angle is set based on the disc warp amount, and the tilt control for the optical pickup 2 is performed through the servo control unit 4.

According to the first embodiment described above, the re-tilt adjustment of the optical pickup is performed when a predetermined time elapses even when the radial warpage of the optical disk changes due to a temperature change with time. Even if the curvature of the optical disk changes, it is possible to perform an appropriate tilt adjustment, thereby preventing the attenuation of the RF signal from the optical pickup and preventing the S / N from decreasing during reproduction. By improving the jitter of the playback signal processing system,
Playback performance can be improved, and at the time of recording, it is possible to improve the recording performance by preventing the deterioration of the accuracy of the tracking error signal from the optical pickup and improving the jitter of the recording signal processing system. it can.

FIG. 7 is a block diagram showing a configuration of an optical disc apparatus according to the second embodiment of the present invention.
Here, the configuration of an optical disc apparatus such as a DVD recorder will be described. Needless to say, the tilt adjustment process described below can also be applied to an optical disc apparatus such as a DVD player during reproduction. 7, components corresponding to those shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted.

In FIG. 7, a temperature sensor 35 is for measuring the temperature in the apparatus. After the spin-up is performed, the temperature in the apparatus rises after the reproduction or recording is started and the measured temperature reaches a predetermined temperature. This is used to adjust the tilt again. Since the other components have been described with reference to FIG. 1, description thereof is omitted here.

FIG. 8 is a flowchart for explaining tilt adjustment processing of the optical pickup in the second embodiment. The tilt adjustment process will be described with reference to this flowchart and FIG.

First, when the optical disk 1 is inserted into the optical disk apparatus (step S1), the system controller 22 starts up by rotating the optical disk 1 slightly, emits laser light from the optical pickup 2, reads the disk information, and reads the optical pickup 2. Spin-up, which is a process until is set to the initial position, is started (step S2). When the spin-up starts and the spin-up is performed, the tilt of the optical pickup 2 is adjusted. In other words, the tilt adjusting means 221 of the system controller 22 controls the servo control unit 4 and the optical pickup 2.
Are respectively moved to a predetermined inner circumference adjustment position and a predetermined outer circumference adjustment position of the optical disc 1, and an optimum tilt angle is obtained at the inner circumference adjustment position and the outer circumference adjustment position to perform tilt adjustment (step S3).

After such tilt adjustment is performed on the optical pickup 2, the reproduction key of the remote controller 21 is pressed to start a reproduction operation (step S4), information is reproduced from the optical disc 1 (step S5), and reproduction is performed. Is not completed (step S6), and when the temperature measured by the temperature sensor 35 reaches a predetermined temperature (for example, 28 ° C.) (step S9a), a tilt adjustment request flag is set in the CPU 24, and in response thereto, the system controller The re-tilt adjustment unit 222 of 22 acquires the optimum tilt angle at the adjustment inner circumference position and the outer circumference adjustment position of the optical disc 1 and performs the re-tilt adjustment (step S10). After this, the process returns to step S5,
Similar processing is performed.

The re-tilt adjustment at the time of reproduction is performed by the tilt adjustment control means 226 of the system controller 22 when reproducing data is read from the RAM 7 as a reproduction buffer memory. That is, when the optical pickup 2 is not reading information from the optical disc 1, the re-tilt adjustment of the optical pickup 2 is performed. Therefore, apparently, the reproduction process and the re-tilt adjustment process are executed in parallel, and there is no influence on the reproduction operation.

In step S4, when the recording operation is started by pressing the recording key of the remote controller 21, or when the recording operation is started due to the arrival of the recording start time by the recording reservation (recording reservation), information is recorded on the optical disc 1. Recording is performed (step S7), and recording does not end (
In step S8), when the temperature measured by the temperature sensor 35 reaches a predetermined temperature (for example, 28 ° C.) (step S9a), a tilt adjustment request flag is set in the CPU 24, and in response thereto, the re-tilt adjustment of the system controller 22 is performed. The means 222 acquires the optimum tilt angle at the adjustment inner circumference position and the outer circumference adjustment position of the optical disc 1 and performs the re-tilt adjustment (step S10).
. Thereafter, the process returns to step S7 and the same process is performed.

According to the second embodiment described above, even when the radial warpage of the optical disk changes due to a temperature change with time, when the temperature measured by the temperature sensor reaches a predetermined temperature, the optical pickup Even if the re-tilt adjustment is performed and the warpage in the radial direction of the optical disk changes, an appropriate tilt adjustment can be performed, thereby preventing the attenuation of the RF signal from the optical pickup during reproduction. / N is prevented, and the reproduction signal processing system jitter is improved, so that the reproduction performance can be improved, and at the time of recording, the accuracy of the tracking error signal from the optical pickup is prevented from being reduced, The recording performance can be improved by improving the jitter of the recording signal processing system.

1 is a block diagram showing a configuration of an optical disc device according to a first embodiment of the present invention. FIG. 6 is a graph showing the relationship between the passage of time and the tilt angle for the optical disc A in which the tilt changes greatly with the passage of time in the first embodiment. FIG. 5 is a graph showing the relationship between the passage of time and the tilt angle for the optical disc B in which the tilt changes greatly with the passage of time in the first embodiment. The relationship between the tilt angle and the amplitude of the RF signal or tracking error signal when acquiring a tilt angle that maximizes the amplitude of the RF signal or tracking error signal during tilt adjustment in the first embodiment will be described. FIG. 6 is a flowchart for explaining tilt adjustment processing of the optical pickup in the first embodiment. 6 is a flowchart for explaining details of a re-tilt adjustment process in step S10 shown in FIG. It is a block diagram which shows the structure of the optical disk apparatus based on the 2nd Embodiment of this invention. 12 is a flowchart for explaining tilt adjustment processing of an optical pickup in the second embodiment.

Explanation of symbols

1 optical disk 2 optical pickup 7 RAM (buffer memory for reproduction)
22 System controller 32 RAM (buffer memory for recording)
35 Temperature sensor 221 Tilt adjusting unit 222 Re-tilt adjusting unit 223 Tilt angle setting unit 224 Position address storage unit 225 Tilt control unit 226 Tilt adjustment control unit

Claims (4)

In an optical disc apparatus for reproducing information recorded on an optical disc or recording / reproducing information on an optical disc,
After the optical disk is loaded, the optical disk is started up, and the optical pickup is moved to a predetermined inner circumference adjustment position and a predetermined outer circumference adjustment position of the optical disk at the time of executing the spin-up that is processing until the optical pickup is set to the initial position. Each is moved to acquire the optimum tilt angle at the inner and outer circumference adjustment positions, and the tilt adjustment means for adjusting the tilt based on the tilt angle, and playback or recording starts after the spin-up is executed A re-tilt adjustment means for performing a re-tilt adjustment when a predetermined time has elapsed since the start or when the temperature measured by the temperature sensor has reached a predetermined temperature after reproduction or recording is started,
For the optimum tilt confirmation of the acquired tilt angle, the current tilt angle setting value is changed by a predetermined amount ±, and the tilt adjustment is performed so that the amplitude of the RF signal is maximized for the recorded area of the optical disc. Tilt angle setting means for setting the optimum tilt angle for each unrecorded area of the optical disc so that the amplitude of the tracking error signal is maximized, and the optical disc when the tilt adjustment is performed at a low temperature Position address storing means for storing the address of the outer periphery adjustment position in the memory, and performing a tilt adjustment at the outer periphery adjustment position indicated by the address read from the memory, and calculating the disc warpage amount at the radial position by primary approximation, Tilt control means for performing tilt control by setting a tilt angle based on the disc warp amount;
A system having tilt adjustment control means for performing control so that the tilt adjustment is performed when reproducing data is read from the reproduction buffer memory during reproduction, and the tilt adjustment is performed when recording data is read from the recording buffer memory during recording. An optical disc apparatus comprising a controller. In an optical disc apparatus for reproducing information recorded on an optical disc or recording / reproducing information on an optical disc,
After the optical disk is loaded, the optical disk is started up, and the optical pickup is moved to a predetermined inner circumference adjustment position and a predetermined outer circumference adjustment position of the optical disk at the time of executing the spin-up that is processing until the optical pickup is set to the initial position. Each is moved to acquire the optimum tilt angle at the inner and outer circumference adjustment positions, and the tilt adjustment means for adjusting the tilt based on the tilt angle, and playback or recording starts after the spin-up is executed A system controller having a re-tilt adjustment means for performing a re-tilt adjustment when a predetermined time has elapsed since the start or when a temperature measured by the temperature sensor has reached a predetermined temperature after reproduction or recording is started. An optical disc apparatus characterized by the above. The system controller changes the set value of the current tilt angle by ± predetermined amount for the optimum tilt confirmation of the acquired tilt angle so that the amplitude of the RF signal is maximized for the recorded area of the optical disc. Tilt adjustment is performed so that the amplitude of the tracking error signal is maximized for an unrecorded area of the optical disc, and a tilt angle setting means for setting an optimum tilt angle, and the tilt at a low temperature state. The position address storage means for storing the address of the outer periphery adjustment position of the optical disk at the time of adjustment in the memory, and the tilt adjustment at the outer periphery adjustment position indicated by the address read from the memory, and performing the first approximation, the disk warpage at the radius position Tilt control means for calculating the amount and setting the tilt angle based on the disc warp amount and performing tilt control. The optical disk apparatus according to claim 2, wherein. The system controller performs tilt adjustment when reproducing data is read from the reproduction buffer memory during reproduction, and tilt adjustment control means for performing control such that tilt adjustment is performed when recording data is read from the recording buffer memory during recording The optical disc apparatus according to claim 2, wherein

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