JPH0793786A - Information processing device - Google Patents

Abstract

PURPOSE:To enable the correct samplings of eccentricity correcting data even at a time of an external disturbance and the changing of a disk revolving speed by synthesizing a scale signal indicating the displacement of an optical head and a lens positional signal indicating the displacement of an objective lens with respect to the optical head. CONSTITUTION:An optical head 3 is moved in the accessing direction of an optical disk 1 with respect to a drive base 50 on which a spindle motor 2 is provided and the position of an objective lens 6 is controlled via an objective lens actuator 40. A scale signal indicating the displacement of the head 3 with respect to the base 50 with the scale sensor 52 of the head 3 and a signal indicating the displacement of the lens 6 with a positional sensor 51 of the actuator 40 are added to be synthesized and a signal indicating the positional relation between the lens 6 and the base 50 corresponding to a disk correcting signal in which the influence of the external disturbance is eliminated is sampled. Moreover, the same signal sampling with respect to a same revolving phase position with regard to a different revolving speed is performed simultaneously with the FG signal from a motor 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing apparatus capable of accurately correcting eccentricity of an optical disk without being affected by disturbance.

[0002]

2. Description of the Related Art Conventionally, an eccentricity correction circuit having an effect of apparently reducing the eccentricity of an optical disk has been used in an information processing apparatus such as an electronic filing apparatus. In this eccentricity correction circuit, conventionally, a correction signal is generated from the eccentricity data by the tracking error signal Tsub at the time of track-on. Further, the sampling start position of the optical disc for the eccentricity correction is arbitrary.

[0003]

The gain characteristic of the tracking servo loop is designed to be higher in the lower frequency range because the DC gain is higher. When it is necessary to change the number of rotations of the optical disk, in the conventional method of sampling the eccentricity data by the tracking error signal Tsub, the tracking servo characteristics are different between the number of rotations A and the number of rotations B. Therefore, the tracking error signal Tsub is As shown in FIG. 15, the rotational speeds A and B are different. Moreover, since the rotation speed-dependent characteristic of the tracking servo characteristic is non-linear as shown in FIG. 16, it cannot be converted by calculation, and it is necessary to perform sampling at different rotation speeds. Therefore, when the rotation speed of the optical disk is changed, the eccentricity correction data of the optical disk must be sampled again each time, which causes a problem that the processing time becomes long. In the past, the optical head was scale-locked and the eccentricity was calculated from the positional relationship between the optical head and the objective lens.However, when vibration is applied from the outside, displacement occurs between the drive base and the optical head. However, there is a problem that the eccentricity of the optical disk cannot be detected correctly. Further, when there is a disturbance such as vibration during sampling, the tracking error signal Tsub also samples the disturbance data, which may lead to erroneous correction.

The present invention has been made in order to solve the above-mentioned problems. It is possible to correctly sample the eccentricity correction data even when a disturbance is applied, and to resample the eccentricity correction data even when the rotation speed is changed. An object of the present invention is to provide an information processing device capable of performing eccentricity correction without any need.

[0005]

The present invention records / records information.
A recording medium for reproducing, a base part to which a motor for rotating the recording medium is fixed, an objective lens for irradiating the recording medium with a beam of light for recording / reproducing information on the recording medium, An objective lens position sensor that detects the eccentricity of the recording medium as a displacement of the objective lens with respect to an optical head equipped with the objective lens, and a correction signal that corrects the eccentricity of the recording medium according to the detected displacement. And means.

Further, according to the present invention, a recording medium for recording / reproducing information, a base portion to which a motor for rotating the recording medium is fixed, and information on / from the recording medium are recorded / reproduced.
An objective lens that irradiates the recording medium with a beam of light for reproduction, a scale sensor that detects the eccentricity of the recording medium as a displacement of an optical head that mounts the objective lens with respect to the base portion, and the detected displacement. And a means for generating a correction signal for correcting the eccentricity of the recording medium.

Furthermore, the present invention provides an optical disc for recording / reproducing information, a drive base to which a motor for rotating the optical disc is fixed, and a beam for the optical disc for recording / reproducing information on the optical disc. An objective lens for irradiating light, an objective lens position sensor for detecting the eccentricity of the optical disc as a displacement of the objective lens with respect to an optical head equipped with the objective lens, and the objective lens for the eccentricity of the optical disc with respect to the drive base. A scale sensor for detecting the displacement of an optical head equipped with a sensor, a means for adding the displacement detected by the objective lens position sensor and the displacement detected by the scale sensor in consideration of the displacement direction, and the adding means for outputting Means for generating a correction signal for correcting the eccentricity of the optical disc in accordance with the displaced displacement It is equipped with.

Furthermore, the present invention provides an optical disc for recording / reproducing information, a drive base to which a spindle motor for rotating the optical disc is fixed, and an optical disc for recording / reproducing information on the optical disc. An objective lens for irradiating a light beam, a means for instructing the phase of the optical disk by one of a revolution mark provided on the optical disk and a pulse generated by the spindle motor, and a synchronization with the output of the phase instructing means Then, the eccentricity of the optical disc is detected in synchronization with the objective lens position sensor that detects the eccentricity of the optical disc as the displacement of the objective lens with respect to the optical head on which the objective lens is mounted, and the eccentricity of the optical disc. It is detected as the displacement of the optical head equipped with the objective lens with respect to the drive base. Scale sensor, a means for adding the displacement detected by the objective lens position sensor and the displacement detected by the scale sensor in consideration of the direction of displacement, and a deviation of the optical disk according to the displacement output by the adding means. Means for generating a correction signal for correcting the core.

[0009]

According to the present invention, the eccentricity data is obtained as an addition value of the scale sensor data and the objective lens position sensor data, and the absolute displacement between the drive base and the objective lens can be measured. In other words, when creating the eccentricity correction table, it becomes possible to accurately measure the eccentricity of the optical disk by combining the positional relationship between the drive base and the objective lens from both the scale signal and the lens position sensor signal. I'm less affected. Further, the eccentricity correction data is sampled in synchronization with the revolution mark of the optical disk or the FG pulse of the spindle motor, so that the eccentricity correction data can be corrected by the same eccentricity correction data for a plurality of rotation speeds of the optical disk. I was able to do it.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 14 is a block diagram showing a schematic structure of the optical disk device. The optical disk device records, reproduces, and erases information on the optical disk 1 by using focused light. The optical disc 1 is rotated at a constant speed by a motor 2. The motor 2 is controlled by the motor control circuit 18. The data recording area of the optical disc 1 is divided into a plurality of sectors on the basis of a reference mark, that is, a revolution mark. Recording and reproduction of information with respect to the optical disc 1 is performed by an optical head. This optical head is fixed to a drive coil 13 that constitutes a movable portion of a linear motor 31, and this drive coil 13 is connected to a linear motor control circuit 17. A scale sensor 52 is connected to the linear motor control circuit 17. The scale sensor 52 detects the position of the scale of the optical header with respect to the drive base. The optical head 3 is moved by the linear motor 31 in the radial direction of the optical disc 1. The optical head 3 holds the objective lens 6,
The objective lens 6 is moved in the focusing direction by the drive coil 5, and is moved in the tracking direction by the drive coil 4. The objective lens position sensor 51 detects the displacement of the objective lens 6. Laser light generated from the semiconductor laser 9 driven by the laser control circuit 14 is irradiated onto the optical disc 1 through the collimator lens 11a, the half prism 11b, and the objective lens 6. The reflected light from the optical disc 1 is the objective lens 6 and the half prism 1.
1b, a condenser lens 10a, and a cylindrical lens 1
It is guided to the photodetector 8 via 0b. Reference numerals 8a to 8d are photodiodes. The tracking control circuit 16 outputs a track drive signal, which is supplied to the drive coil 4. The tracking error signal is the tracking control circuit 16
Is supplied to the linear motor control circuit 17. The signal processing circuit 19 reproduces information on the optical disc 1 and outputs a reproduction signal. The access direction detection circuit 35 uses the track error signal from the track error signal circuit 42 and the track sum signal from the track sum signal circuit 43 to output a track detection signal or the like in which a noise signal is removed from the track error signal. The tracking control circuit 16 and the like are controlled by the CPU 23 via the bus line 20. CPU
23 performs a predetermined operation according to a program stored in the memory 24.

FIG. 1 is a schematic diagram showing the structure of an optical disk drive. The objective lens 6 is attached to the drive base 50 on the optical head 3 that can be moved in the access direction of the optical disk 1 via an objective lens actuator 40 that can also be moved in the access direction. An objective lens position sensor 51 that outputs an objective lens position sensor (LNS) signal indicating the displacement of the objective lens 6 with respect to the optical head 3 is attached to the objective lens actuator 40. A scale sensor 52 that outputs a scale sensor (SCK) signal indicating the displacement of the optical head 3 with respect to the drive base 50 is attached to the optical head 3. In the present invention, the eccentricity of the optical disc 1 can be obtained as the positional relationship between the drive base 50 and the objective lens 6. Therefore, according to the present invention, the measurement of the eccentric shape of the optical disc 1 is performed with the SCK signal and the LN.
It is obtained from the composite waveform of the S signal so that an accurate eccentric shape can be obtained even if there is a disturbance. Also,
By synchronizing the start of sampling of the eccentricity signal with the FG signal of the spindle motor 2 or the like,
The eccentricity correction data is output at the same phase of the optical disc 1.

FIG. 2 is a top view showing the structure of the objective lens position sensor 41. The objective lens 6 is driven by the yokes 47a-47d in the coil bobbin 43. The displacement of the objective lens position sensor 51 is measured by reflecting the light from the light emitting diode 44 by the mirror 46 and receiving the light by the photo sensor 45. The output of the objective lens position sensor 51 is proportional to the displacement of the objective lens 6, as shown in FIG.

FIG. 4 is a top view and a side view showing the structure of the scale sensor 52. Scale sensor (movable part) 52
The a is movably mounted on the scale (fixed part) 52b. The scale sensor 52a is provided with a light emitting diode 60, a slit 61, and a photo sensor 62. The slits 52b1 are formed at equal intervals on the scale 52b, and the slits 6b of the scale sensor 52a are formed.
1 is formed by the positional relationship of the slits A and B. When the scale sensor 52a moves on the scale 52b,
The sensor output has the relationship shown in FIG. 5 with respect to the moving distance.

Next, the operation of the present invention will be described.

In the optical disk drive, the light beam follows the track of the optical disk 1 by the lens actuator 40 which moves the optical head 3 and the objective lens 6 which can be moved by the linear motor 31 in the tracking direction. The relationship between the optical head 3 and the objective lens 6 can be detected by the objective lens position sensor 51, and the positional relationship between the drive base 50 and the optical head 3 can be detected by the scale sensor 52. In the method of sampling the eccentricity data by the displacement of the scale sensor 52 and the displacement of the objective lens position sensor 51, the frequency characteristics of the scale sensor 52 and the objective lens position sensor 51 are as shown in FIG.
Since the rotation speed A and the rotation speed B have the same characteristics, the eccentricity correction can be performed with the same eccentricity data even if the rotation speed changes. Therefore, even if the number of rotations is changed, it is not necessary to resample the eccentricity correction data, and the operation becomes faster.

During normal tracking, the optical head 3 and the objective lens 6 follow the eccentricity at a ratio of 5: 1 to 10: 1. In this case, the eccentricity data is as shown in FIG.
As shown in, the displacement data of the scale sensor 52 and the displacement data of the objective lens position sensor 51 are generated in the same direction, and therefore the original accurate displacement data can be obtained by adding both displacement data. On the other hand, even when a disturbance such as external vibration is applied to the body of the information processing device, the drive base 5
The relative positional relationship between 0 and the optical disk 1 does not change, and only the optical head 3 shifts and vibrates due to external vibration.
At this time, the positional relationship among the drive base 50, the optical head 3, and the objective lens 6 is as shown in FIG. 8, and the displacement data of the scale sensor 52 and the objective lens position sensor 51 are shown.
The displacement data of is generated in the opposite direction. Also in this case,
By adding the displacement data of the scale sensor 52 and the displacement data of the objective lens position sensor 51, correct eccentricity data can be sampled as shown in FIG. 9D. This is shown in FIG. 9 (A) when disturbance is applied to the device.
As shown in (B), the disturbance appears in both the SCK signal output by the scale sensor 52 and the LNS signal output by the objective lens position sensor 51.
If you subtract the K signal, you can cancel the influence of the disturbance.
This is because a correct eccentricity correction signal can be obtained as shown in FIG. This eccentricity correction signal matches the true eccentricity. As described above, in the present invention, eccentricity correction can be performed by the same method during normal tracking and when disturbance is applied. The eccentricity correction is performed by the CPU 23 in FIG.

The size of the eccentricity is determined by the sector direction of the optical disc 1, but when the rotation speed of the optical disc 1 is changed, the position of the sector of the optical disc 1 deviates from the optical head 3, Correlation between the sector of the optical disc 1 and the reference clock designated by the CPU cannot be obtained. Therefore, in the present invention, when sampling the eccentricity data for the first time, the reversal mark 1a of the optical disc 1 shown in FIG.
The sampling of the eccentricity data is started in synchronization with the FG pulse of the spindle motor 2 shown in FIG. That is, after the rotation speed of the optical disc 1 is changed, synchronization is re-established by using the revolving mark 1a or the FG pulse indicating a predetermined specific phase of the optical disc 1, for example, 0 sector, so that the sector of the optical disc is always correlated with the clock. Can be kept. The details will be described below with reference to the flowchart.

FIG. 12 is a flow chart for explaining the sampling timing when the eccentricity data of the optical disc 1 is sampled. First, it is judged that the optical disk 1 has 0 sectors by using the revolution mark 1a or the FG pulse (step s10). If the sector is not 0, the determination is repeated. If the number of sectors is 0, the sector count is reset (step s11). Next, the displacement data of the scale sensor 52 and the displacement data of the objective lens position sensor 51 are sampled for each sector (step s12). Both displacement data are added and stored in the deviation correction table in the CPU 23 (step s13). In this case, only the displacement data of the scale sensor 52 or the objective lens position sensor 5
The eccentricity correction of the optical disc 1 can be performed only with the displacement data of 1.

FIG. 13 is a flow chart for explaining the sampling timing when the rotation speed of the optical disk is changed. First, it is determined whether or not the rotation speed of the optical disc 1 has changed (step s21). If there is no change in the number of revolutions, the process will wait until the number of revolutions changes.
When the number of rotations is changed, it is determined that the optical disk 1 has reached 0 sector by using the revolution mark 1a or the FG pulse (step s22). 0
If it is not a sector, the determination is repeated. 0
If it is a sector, the sector count is reset (step s23). Next, the displacement data of the scale sensor 52 and the displacement data of the objective lens position sensor 51 are sampled and added for each sector to output eccentricity correction data (step s24).

[0021]

As described above, according to the present invention,
When creating the eccentricity correction table, the eccentricity correction data can be accurately measured by synthesizing the positional relationship between the drive base and the objective lens from both the scale signal and the lens position sensor signal. In addition, correct eccentricity correction data can be sampled even when disturbance such as external vibration is applied. Further, even when the rotation speed of the optical disk is changed, the eccentricity correction data can be corrected by sampling the eccentricity data at different rotation speeds without sampling the eccentricity correction data again.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of an optical disc drive.

FIG. 2 is a top view showing the configuration of an objective lens position sensor.

FIG. 3 is a characteristic diagram showing an output of an objective lens position sensor.

4A and 4B are a top view and a side view showing a configuration of a scale sensor.

FIG. 5 is a characteristic diagram showing sensor output of a scale sensor.

FIG. 6 is a diagram showing frequency characteristics of a scale sensor and an objective lens position sensor.

FIG. 7 is a diagram illustrating displacement of a sensor during normal tracking.

FIG. 8 is a diagram for explaining the displacement of the sensor when a disturbance is applied.

FIG. 9 is a diagram showing a scale sensor signal, an objective lens position sensor signal, an eccentricity correction signal, and a true eccentricity.

FIG. 10 is a diagram showing a revolution mark on an optical disc.

FIG. 11 is a schematic diagram showing a configuration of a spindle motor.

FIG. 12 is a flowchart illustrating sampling timing when sampling eccentricity data on the optical disc 1.

FIG. 13 is a flowchart illustrating sampling timing when the number of rotations of the optical disc is changed.

FIG. 14 is a block diagram showing a schematic configuration of an optical disc device.

FIG. 15 is a diagram showing a tracking error signal.

FIG. 16 is a characteristic diagram of tracking servo.

[Explanation of symbols]

1 ... Optical disc, 1a ... Revolution mark, 2 ... Spindle motor, 3 ...
.Optical head, 14 ... Laser control circuit, 15
・ ・ ・ Focusing control circuit, 16 ・ ・ ・ Tracking control circuit, 17 ・ ・ ・ Linear motor control circuit, 18 ・ ・ ・ Motor control circuit, 19 ・ ・ ・
Signal processing circuit, 20 ... Bus, 23 ... C
PU, 24 ... Memory, 25 ... D / A converter, 31 ... Linear motor, 32 ... Interface circuit, 33 ... Disk control circuit,
34 ... Recording signal generating circuit, 35 ... Access direction detecting circuit, 36 ... Track counter circuit, 40 ... Lens actuator, 50 ...
Drive base, 51 ... Objective lens position sensor, 52 ... Scale sensor.

Claims (4)

[Claims] 1. A recording medium for recording / reproducing information, a base portion to which a motor for rotating the recording medium is fixed, and a recording medium for recording / reproducing image information of the recording medium. An objective lens for irradiating a beam of light, an objective lens position sensor for detecting the eccentricity of the recording medium as a displacement of the objective lens with respect to an optical head having the objective lens mounted thereon, and the recording medium according to the detected displacement. An information processing apparatus comprising: a means for generating a correction signal for correcting the eccentricity of the information processing apparatus. 2. A recording medium for recording / reproducing information, a base portion to which a motor for rotating the recording medium is fixed, and a beam for the recording medium for recording / reproducing information on the recording medium. An objective lens that emits light, a scale sensor that detects the eccentricity of the recording medium as a displacement of an optical head equipped with the objective lens with respect to the base portion, and a deviation of the recording medium that corresponds to the detected displacement. An information processing apparatus comprising: a means for generating a correction signal for correcting the core. 3. An optical disc for recording / reproducing information, a drive base to which a motor for rotating the optical disc is fixed, and a beam light is irradiated to the optical disc for recording / reproducing information on the optical disc. An objective lens, an objective lens position sensor for detecting the eccentricity of the optical disc as a displacement of the objective lens with respect to an optical head having the objective lens mounted thereon, and an optical disc having the objective lens for the eccentricity of the optical disc with respect to the drive base. A scale sensor that detects the displacement of the head, a unit that adds the displacement detected by the objective lens position sensor and the displacement detected by the scale sensor in consideration of the direction of displacement, and the displacement output by the adding unit. And a means for generating a correction signal for correcting the eccentricity of the optical disc. An information processing device characterized by the above. 4. An optical disk for recording / reproducing information, a drive base to which a spindle motor for rotating the optical disk is fixed, and a beam light irradiating the optical disk for recording / reproducing information on the optical disk. Objective lens, means for instructing the phase of the optical disc by one of the revolving mark provided on the optical disc and the pulse generated by the spindle motor, and the means for synchronizing with the output of the phase instructing means. An objective lens position sensor that detects the eccentricity of the optical disc as a displacement of the objective lens with respect to an optical head having the objective lens mounted thereon, and the eccentricity of the optical disc with respect to the drive base in synchronization with the output of the phase indicating means. Scale that detects displacement of an optical head equipped with an objective lens Sensor, means for adding the displacement detected by the objective lens position sensor and the displacement detected by the scale sensor in consideration of the direction of displacement, and the eccentricity of the optical disk according to the displacement output by the adding means. An information processing apparatus comprising: a unit for generating a correction signal for correction.