JPH09274724A - Optical disk reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To narrow an adjusting range, to shorten an adjusting time, to improve adjustment precision and to simplify constitution by changing and setting an adjusting reference value being a reference of automatic adjustment of a servo circuit in accordance with respective optical disk reproducing device. SOLUTION: A tracking servo circuit 20 detects deviation of a light focal position form a track, and drives a tracking actuator so as to follow up it. When impossible, the circuit 20 moves an optical pickup 14 to a prescribed place. A forces error detection part 18 detects the upper/lower deviation of the light focal position, and drives a focusing actuator by a focus servo circuit 23 to make follow up it. A disk rotation servo circuit 19 controls a disk motor 13 so that a linear velocity becomes a prescribed speed. In such a case, respective servo circuits are able to change and set the adjusting reference value becoming the reference of the automatic adjustment according to respective optical disk reproducing devices, and the adjusting range is narrowed, and the adjusting time is shortened, and the adjustment precision is improved and the constitution is simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical disk reproducing apparatus capable of surely performing automatic adjustment of an optical system servo in an optical disk reproducing apparatus such as a CD player.

[0002]

2. Description of the Related Art An optical disk reproducing apparatus optically reads and reproduces a signal recorded on an optical disk without contacting the optical disk. That is, the signal recorded on the optical disk is read and reproduced by irradiating the signal recording section of the optical disk with a light beam and receiving the reflected light that changes according to the signal recorded on the signal recording section. However, in order to read the signal recorded on the optical disk, it is necessary to follow the signal recording portion of the optical disk and irradiate the light beam accurately, and it is also necessary to focus the optical system.

For this reason, various servo devices are provided in the optical disc reproducing apparatus. This is to control various actuators by a feedback system from the state of a signal recorded on an optical disk which is read by an optical pickup which receives a reflected light by irradiating a signal recording portion of the optical disk. The main thing is to optically detect the left / right deviation from the signal recording part so that the optical pickup can stably follow the predetermined signal recording part of the optical disc, and to set the objective lens inside the optical pickup to the optical disc. A tracking servo for localizing the sound is provided at the center of the signal recording unit. Also, in order to focus the reflected light received by the optical pickup, a focus servo is provided that optically detects the deviation of the distance from the optical disc and keeps the distance between the objective lens inside the optical pickup and the optical disc constant. Has been.

However, since the optical characteristics of the optical disk reproducing apparatus or the variations of the optical disk are absorbed, the operating conditions of these servo apparatuses, for example, the offset amount that affects the control center value and the like, the control sensitivity, and the like are affected. It is necessary to adjust the gain (feedback gain).

[0005]

However, the adjustment value of the servo device of the optical disc reproducing apparatus is set to a large adjustment variable range in order to add variations due to external factors such as the optical disc or temperature or variations of the optical disc reproducing apparatus. There is a need to. For this reason, it is necessary to set an adjustment value in a wide range of values at the time of adjustment to measure the characteristics, and there is a problem that adjustment takes a long time. Further, if the interval between the adjustment values set to shorten the adjustment time is increased, there is a problem that the accuracy of the adjustment deteriorates.

An object of the present invention is to solve the above problems, and it is an object of the present invention to always operate a tracking servo, a focus servo, etc. under appropriate operating conditions.

[0007]

In order to achieve the above object, the present invention is an apparatus for reproducing an optical disk by an optical pickup, and an optical system servo for following and reading a signal recorded on the optical disk. In an optical disk reproducing apparatus in which automatic adjustment of the means is possible by setting an adjustment value, rewritable reference value storage means for storing an adjustment reference value serving as a reference value during automatic adjustment of the optical system servo means, and the reference value Adjusting means for adjusting the optical system servo means based on the adjustment reference value stored in the storage means.

Further, it has a variable range storing means for storing an adjustable variable range, and the adjusting means adjusts the optical system servo means with an adjusting value within a range determined based on the adjusting reference value and the adjusting variable range. It is characterized by Further, the adjusting means repeatedly performs the adjusting operation a predetermined number of times if the optical system servo means cannot be adjusted within the adjusting range.

Further, the adjusting means repeats the adjusting operation a predetermined number of times unless the adjustment of the optical system servo means is completed within a prescribed time. Further, the adjusting means sets the reference value as an adjustment value of the optical system servo means when the adjustment is not normally completed even if the adjusting operation is executed. Further, the adjustment means, when the adjustment does not end normally even if the adjustment operation is executed,
An adjustment value is set to an upper limit or a lower limit of the adjustment range.

[0010]

1 is a block diagram showing a schematic structure of an optical disk reproducing apparatus according to the present invention. Optical disc 1
Information to be reproduced (for example, music information), a sync signal necessary for reproducing the reproduced information, a sub-code, and the like are recorded in the signal recording unit 1 as digital signals. This optical disc 11
Is loaded or ejected on a disc mounting portion (turntable) (not shown) by a loading mechanism (not shown) in accordance with an operation of the key operation unit 12 or the like.
The disc motor 13 drives the optical disc 11 mounted on the disc mounting portion at a predetermined rotation speed. The digital signal recorded in the signal recording section of the optical disk 11 is optically read by the optical pickup 14. The digital signal read by the optical pickup 14 is amplified to a predetermined level by the preamplifier 15 and sent to the signal conversion circuit 16, and is also input to the tracking error detection unit 17, the focus error detection unit 18, and the disc rotation servo circuit 19. .

The tracking error detection unit 17 detects from the output signal of the optical pickup 14 that the focal position of the reading light beam emitted from the optical pickup 14 is displaced inside or outside the signal recording unit (track) of the optical disk 11. It is detected and output to the tracking servo circuit 20. The tracking servo circuit 20 has a microcomputer 21.
The operating signal is controlled by the output signal from the optical disc 11, and the reading light beam follows the signal recording portion of the optical disc 11 in response to the signal from the tracking error detecting portion 17 in the operating state, for tracking (not shown). Drive the actuator. Further, for a large movement that cannot be followed by the tracking actuator, the pickup feed servo circuit 22 operates in response to a signal from the tracking error detector 17, and the pickup feed mechanism (not shown) moves the optical pickup 14 to a predetermined position by a feed motor. To move.

The focus error detection unit 18 detects from the output signal of the optical pickup 14 that the focus position of the reading light beam is displaced above or below the signal recording unit of the optical disk 11, and outputs it to the focus servo circuit 23. The focus servo circuit 23 is controlled in operation and non-operation by an output signal from the microcomputer 21, and in an operating state, the focus servo circuit 23 responds to a signal from the focus error detection unit 18 by moving an objective lens (not shown) of the optical pickup 14 to a focus actuator. Up and down.

The disc rotation servo circuit 19 is arranged so that the frequency of the internal reference signal and the frequency of the synchronizing signal included in the output signal of the optical pickup 14 match, that is, the linear velocity becomes a predetermined velocity. Disk motor 13
To control the rotation speed of the. The signal conversion circuit 16 performs error correction and EFM demodulation processing on the signal from the optical pickup 14 to convert the signal into a digital audio signal, and outputs the digital audio signal to an analog circuit via a digital-analog converter (not shown). A subcode which is a control signal recorded by being mixed with the audio signal is extracted and output to the microcomputer 21. Further, the signal conversion circuit 16 outputs an error signal to the microcomputer 21 when the signal cannot be read due to scratches on the optical disk 11 or when the extracted subcode is abnormal. In addition, microcomputer 2
Reference numeral 1 outputs an adjustment value for setting a servo gain or the like to each servo circuit 19, 20, 22, 23, and controls the operation of each servo circuit 19, 20, 22, 23.

FIG. 2 is a conceptual diagram showing the principle of adjustment of the servo system according to this embodiment. For example, it is estimated that the reference value (theoretical value of design) of the adjustment value is 30, the deviation of the adjustment value due to the variation of the optical disc reproducing apparatus itself is ± 5, and the deviation of the adjustment value due to the variation of the optical disc is ± 5. Then, the adjustment variable range of the adjustment value necessary to absorb the variations of both is 20 to 40. In the present embodiment, the reference value (center value) of the adjustment range is settable, and the adjustment reference value is set for each optical disk reproducing device when the optical disk reproducing device is completed. By setting the range in which the deviation of the adjustment value due to the variation of itself can be absorbed, the adjustment time is shortened, the adjustment accuracy is improved, and the configuration of the memory and the like is simplified. If the adjustment reference value is 27 under the above conditions,
The necessary adjustment variable range of the adjustment value is 22 to 32, and it is possible to shorten the adjustment time, improve the adjustment accuracy, simplify the configuration of the memory and the like.

Next, an automatic adjustment procedure of the servo system of the first embodiment will be described. 3A and 3B are flowcharts showing the adjustment procedure of the servo apparatus according to the first embodiment. FIG. 3A shows an adjustment reference value setting process and FIG. 3B shows an automatic measurement process. FIG.
The setting process of the adjustment reference value of the optical system servo device in the optical disc reproducing device shown in (a) is performed by the manufacturer of the optical disc reproducing device after the assembly inspection,
This process is performed in the adjustment reference value setting process of the optical system servo means in the adjustment process, but if a special operation such as a switch is performed, this process starts and moves to step S11. Step S11
Then, the reference disk (a disk set as a reference by the maker and mounted by an operator or the like and put into a reproduction state) is reproduced, and automatic adjustment is performed in the optical system servo means, and the process proceeds to step S12. In step S12, the writing process is finished in a non-volatile memory such as an EEPROM that can be rewritten with the adjustment value set by the automatic adjustment process as the reference adjustment value. That is, the adjustment value that absorbs the variation of each optical disk reproducing device is set as the adjustment reference value. The adjustment variable range is fixed, for example, ± 5 (written in a non-rewritable ROM or the like).

The automatic adjustment processing of the optical system servo device in the optical disc reproducing apparatus shown in FIG. 3B is performed when the power is turned on, when the disc is replaced, or when the reproducing condition is different. In step S13, the servo device of the optical disc reproducing device is automatically adjusted with respect to the reproduced optical disc, and the process proceeds to step S14. This adjustment is performed by sequentially changing the adjustment value over the adjustment variable range and setting a value at which the output signal becomes the target value (design value) as the adjustment value. In step S14, it is determined whether or not the number of executions of the automatic adjustment is less than or equal to a predetermined number (for example, three times). If the number of executions is equal to or more than the predetermined number, the process proceeds to step S17. Move.
That is, if the automatic adjustment is executed several times and the adjustment is not successful, the process proceeds to step S17.

In step S15, it is determined whether or not the automatic adjustment is completed within the specified time (for example, 2 seconds). If the automatic adjustment is not completed within the specified time, the process returns to step S13, and the automatic adjustment is completed within the specified time. If so, the process proceeds to step S16. That is, if the automatic adjustment is not completed within the specified time, it is determined that an abnormality has occurred and the automatic adjustment is performed again. In step S16, it is determined whether the automatic adjustment is adjusted within the adjustment variable range. If the automatic adjustment is not adjusted within the adjustment variable range, the process returns to step S13, and in step S16, the automatic adjustment is adjusted within the adjustment variable range. If so, the automatic adjustment ends. That is, if the automatic adjustment is successful so as to achieve the target operating state, the automatic adjustment processing is ended, and if not successful, the automatic adjustment is performed again.

Further, in step S17, step S1
The adjustment is terminated by using the adjustment reference value set in 1 and stored in the RAM or the like as the adjustment value. In other words, if the automatic adjustment operation is not repeated within the specified time even if the automatic adjustment operation is repeated a predetermined number of times or if the adjustment cannot be performed within the preset adjustment variable range, the preset adjustment reference value is adjusted. Set as a value and end the adjustment.

As described above, according to this embodiment, the automatic adjustment is performed within the adjustment range for the variation of the optical disc to be reproduced, so that the adjustment time can be shortened, the adjustment accuracy can be improved, and the configuration can be simplified. it can. Next, an automatic adjustment procedure of the servo apparatus of the second embodiment will be described. FIG. 4 is a flowchart showing the adjustment procedure of the servo system according to the second embodiment.
(A) shows an adjustment reference value setting process, and (b) shows an automatic measurement process.

The setting process of the adjustment reference value of the optical system servo device in the optical disk reproducing device shown in FIG.
It is performed in the adjustment reference value setting process of the optical system servo means in the product inspection and adjustment process after the assembly is completed in the manufacturer of the optical disc reproducing device. For example, if a special operation such as a switch is performed, this process starts. Move on to. In step S21, a reference disc (a disc set as a reference by the maker, which is mounted and put into a reproduction state by an operator or the like), is automatically adjusted by the optical system servo means, and the process proceeds to step S22. In step S22, the writing process is finished in a non-volatile memory such as an EEPROM that can be rewritten with the adjustment value set by the automatic adjustment process as the reference adjustment value. That is, the adjustment value that absorbs the variation of each optical disk reproducing device is set as the adjustment reference value. The value indicating the amount of deviation from the adjustment reference value that defines the adjustment variable range is fixed, for example, ± 5.

The automatic adjustment processing of the optical system servo device in the optical disk reproducing apparatus shown in FIG. 4B is performed when the power is turned on, the disk is replaced, and the reproducing condition is different. In step S23, the servo device of the optical disc reproducing device is automatically adjusted with respect to the optical disc in the reproducing state, and the process proceeds to step S24. This adjustment is performed by sequentially changing the adjustment value over the adjustment variable range and setting a value at which the output signal becomes the target value (design value) as the adjustment value. In step S24, it is determined whether or not the number of executions of the automatic adjustment is less than or equal to a predetermined number (for example, 3 times). Move.
In other words, even if the automatic adjustment is executed several times, if the adjustment is not successful, the process proceeds to step S27.

In step S25, it is determined whether or not the automatic adjustment is completed within the specified time (for example, 2 seconds). If the automatic adjustment is not completed within the specified time, the process returns to step S23, and the automatic adjustment is completed within the specified time. If so, the process proceeds to step S26. That is, if the automatic adjustment is not completed within the specified time, it is determined that an abnormality has occurred and the automatic adjustment is performed again. In step S26, it is determined whether or not the automatic adjustment is adjusted within the adjustment variable range. If not adjusted within the adjustment variable range, the process returns to step S23, and in step S26 the automatic adjustment is adjusted within the adjustment variable range. If so, the automatic adjustment ends. That is, if the automatic adjustment is successful so as to achieve the target operating state, the automatic adjustment processing is ended, and if not successful, the automatic adjustment is performed again.

Further, in step S27, step S2
Set the upper limit value or the lower limit value (value on the side where the output is close to the target output value) of the adjustment variable range determined by the adjustment reference value set in 2 and stored in the RAM and the value indicating the amount of deviation as the adjustment value To finish. That is, if the automatic adjustment operation is not repeated within the specified time even if the automatic adjustment operation is repeated a predetermined number of times or if the adjustment cannot be performed within the preset adjustment variable range, the upper limit value or the lower limit value of the adjustment variable range is set. Set as the adjustment value and end the adjustment. That is, the optimum state is set within the adjustable range.

As described above, according to this embodiment, the automatic adjustment is performed within the adjustment range for the variation of the optical disc to be reproduced, so that the adjustment time can be shortened, the adjustment accuracy can be improved, and the configuration can be simplified. it can. Also, even if the adjustment is not successful, it becomes possible to play back in the optimum state within the adjustable range.

[0025]

As described above, according to the optical disc reproducing apparatus of the present invention, since the adjustment reference value, which is the reference of automatic adjustment, can be set by changing the optical disc reproducing apparatus, the adjustment variable range can be narrowed and the adjustment can be performed. It is possible to shorten the time, improve the adjustment accuracy, and simplify the configuration.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of an optical disc reproducing apparatus according to the present invention.

FIG. 2 is a conceptual diagram showing adjustment values of the servo device according to the present invention.

FIG. 3 is a flowchart showing an adjustment procedure of the servo apparatus according to the first embodiment.

FIG. 4 is a flowchart showing an adjustment procedure of the servo apparatus according to the second embodiment.

[Explanation of symbols]

 11 ... Optical disc 12 ... Key operation part 13 ... Disc motor 14 ... Optical pickup 15 ... Preamplifier 16 ... Signal conversion circuit 17 ... Tracking error detection part 18 ... Focus Error detection unit 19 ... Disk rotation servo circuit 20 ... Tracking servo circuit 21 ... Microcomputer 22 ... Pickup feed servo circuit 23 ... Focus servo circuit

Claims (6)

[Claims] 1. An apparatus for reproducing an optical disc by an optical pickup, wherein the optical system servo means for tracking and reading a signal recorded on the optical disc is automatically adjustable by setting an adjustment value. In the reproducing apparatus, a rewritable reference value storage unit that stores an adjustment reference value that serves as a reference value when the optical system servo unit is automatically adjusted, and the optical system based on the adjustment reference value stored in the reference value storage unit. An optical disc reproducing apparatus comprising: an adjusting unit that adjusts a servo unit. 2. A variable range storage means for storing an adjustment variable range, wherein the adjusting means adjusts the optical system servo means with an adjustment value within a range determined based on the adjustment reference value and the adjustment variable range. The optical disc reproducing apparatus according to claim 1, wherein: 3. The optical disk reproducing apparatus according to claim 2, wherein the adjusting means performs an adjusting operation repeatedly a predetermined number of times if the optical system servo means cannot be adjusted within the adjusting range. 4. The optical disk according to claim 1, wherein the adjusting means repeatedly performs a predetermined number of adjustment operations unless the adjustment of the optical system servo means is completed within a specified time. Playback device. 5. The adjusting means uses the reference value as an adjusting value of the optical system servo means when the adjusting operation is not normally completed even if the adjusting operation is executed. The optical disc reproducing apparatus according to claim 2, claim 3, or claim 4. 6. The adjusting device according to claim 1, wherein the adjusting means sets an adjusting value to an upper limit or a lower limit of the adjustment range when the adjustment is not normally completed even if the adjusting operation is executed. The optical disc reproducing apparatus according to claim 3 or 4.