JP3102759B2 - Inspection method for optical disk playback device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method for testing the scratch resistance of an optical disk reproducing apparatus such as a compact disk (hereinafter abbreviated as "CD").

[0002]

2. Description of the Related Art In recent years, optical disks such as CDs and mini disks (hereinafter abbreviated as "MD") for in-vehicle and portable audio devices, and optical disks such as CD-ROMs for navigation devices have been widely used as large-capacity data storage media. Have been. In an in-vehicle or portable optical disk reproducing apparatus, it is necessary to reproduce data under adverse conditions such as vibration. For this reason, in product inspection after the manufacture of the optical disk reproducing apparatus, it is necessary to inspect that a phenomenon such as skipping in which the reproduction output changes discontinuously due to vibration or the like does not occur within a certain standard. In addition, it is necessary to check that sound skipping does not occur even if the surface of the optical disk has a flaw within a certain range.

[0003]

The optical disk reproducing apparatus is configured to be able to recover data within a certain range even if a data reading error occurs due to a scratch or vibration on the surface. For this reason, in the inspection of the scratch resistance performance,
On the contrary, it is difficult to judge. Conventionally, operators have to rely on sensory evaluations confirmed by ears and eyes, and there is a possibility that quality may vary depending on individual differences and surrounding environment. In addition, since the work is troublesome, it is disadvantageous in terms of man-hours.

An object of the present invention is to provide a method for inspecting an optical disk reproducing apparatus which can surely inspect the scratch resistance performance and can be easily automated.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a method for inspecting the scratch resistance of an optical disk reproducing apparatus for optically reading and reproducing information recorded as digital signals on an optical disk. When a test optical disc with a flaw is inserted into the optical disc reproducing apparatus to reproduce recorded information and to vibrate according to preset conditions, and when the distortion included in the reproduced output exceeds a reference level. By determining that sound skipping occurs,
This is an inspection method for an optical disk reproducing device, which is characterized by determining the scratch resistance performance. According to the present invention, when playing back a test disc with a flaw added in advance, if the distortion included in the reproduced output exceeds a reference level, it is determined that the sound is skipped. Without relying on sensory evaluations confirmed by ears and eyes, and without being affected by individual differences or the surrounding environment, it is possible to perform a reliable examination of scratch resistance performance.

Further, since the scratch resistance performance test is performed while applying vibration in accordance with preset conditions, operation in a severe environment required for a vehicle-mounted or portable optical disk reproducing apparatus can be guaranteed.

In the present invention, the preset condition is recorded on a test optical disk to which a flaw is added in advance. According to the present invention, since the conditions of the vibration applied to the optical disk reproducing device are recorded on the test optical disk, the condition can be set only by inserting the test optical disk into the optical disk reproducing device to be inspected. .

[0008]

FIG. 1 shows a schematic electrical configuration of an inspection apparatus of an optical disk reproducing apparatus according to an embodiment of the present invention. The optical disc reproducing device 1 is a CD or M
Plays data stored on an optical disk such as D. The test optical disk 2 is used for the inspection of the scratch resistance of the optical disk reproducing apparatus 1. The output from the optical disc reproducing device 1 that has reproduced the test optical disc 2 is input to the skipping judging device 3 to judge whether or not the skipping whose output level changes discontinuously occurs. When the sound skip determination device 3 determines that the sound skip is occurring, the count value of the counter 4 increases. A personal computer 5 is connected to determine the scratch resistance of the optical disc reproducing apparatus 1 based on the count value of the counter 4.
The count value of the counter 4 is input to the personal computer 5, and the count value is evaluated according to test conditions preset in the personal computer 5. The data processed by the personal computer 5 is displayed as an image on the display device 6, for example.

The optical disk reproducing apparatus 1 is mounted on a vibration generating device 7, and is externally subjected to vibration under vibration conditions set by the personal computer 5. Even if the vibration is generated in one direction, the frequency and amplitude of the vibration can be set from the personal computer 5. Further, a configuration in which the direction and mode of vibration are changed is also possible. The judgment level of the sound skipping judging device 3 and the vibration conditions generated by the vibration generating device 7 are set in advance in the personal computer 5 and stored in the test conditions and the TO condition of the test optical disc 2.
It can be set based on data stored in the C section or the like.

The optical disc reproducing apparatus 1 has an important optical self-adjustment function for reproducing an optical disc. The adjustment function of the optical system built in the optical disk reproducing device 1 is branched from the output from the optical disk reproducing device 1 to the sound skip determination device 3 and is directly input to the personal computer 5. In the personal computer 5, the data is digitally converted by an analog / digital conversion (hereinafter abbreviated as "A / D") circuit and stored in a memory in the personal computer 5. As described above, the test optical disc 2 may have test conditions set in the TOC section or the like as described above. In such a case, the inspection is performed based on the conditions read by the personal computer 5.

The optical disk reproducing apparatus 1 has various servo circuits, and adjustment values adjusted by self adjustment are stored in the personal computer 5. The operation of reading out the adjustment value related to the self-adjustment function from the optical disc reproducing device 1 to the outside is performed in advance on the operation input unit 11 provided on the front panel of the optical disc reproducing device 1 so as not to be performed by a normal operation. It is activated by performing an operation according to a specific operation procedure to be determined. The test optical disc 2 has a plurality of scratches 12 formed concentrically on one radius. Wound 1
Various widths and depths of 2 can be formed according to inspection conditions. The optical disc reproducing apparatus 1 is also provided with a display unit 13 for displaying an address being reproduced or the like.

FIG. 2 shows a partial sectional structure of the test optical disk 2 shown in FIG. As with a general CD or the like, the test optical disk 2 stores a test program source and the like. The storage in the test optical disk 2 is performed according to the presence or absence of a concave portion called a pit 20. When the pits 20 are formed, when the laser light 22 focused by the lens 21 passes through the transparent layer 23 and is irradiated, the reflection intensity of the reflection film 24 changes, and stored data can be read. The back surface of the reflective film 24 is covered with a protective film 25, and the pits 20 are protected. When the scratch 12 is formed on the surface of the transparent layer 23, the laser light 22 is scattered, and the reflection intensity from the pit 20 decreases. When the scratch 12 is large, normal data cannot be read for a long time along the circumferential direction of the surface of the test optical disk 2. In the optical disc reproducing device 1,
By reading the rows of the pits 20, self-adjustment such as rotation servo, focus servo, and tracking servo is performed. If data from the pits 20 cannot be read normally for a long time, the positional accuracy of the laser beam 22 applied to the pits 20 also decreases.

CDs and MDs have an error correction function so that a certain amount of data error can be dealt with. However, if data reading errors continue for a long time, error correction becomes impossible. For this reason, an unnatural change occurs in the reproduced audio signal or the like, resulting in skipping.

FIG. 3 shows an electrical configuration of the sound skip determination device 3 of FIG. The analog-converted playback output from the optical disc playback device 1 is amplified by the amplifier circuit 31 and converted to a fixed polarity by the absolute value circuit 32. If the skipping occurs in the playback output from the optical disc playback device 1, the output level of the absolute value converted by the absolute value circuit 32 increases. The output of the absolute value circuit 32 is
3 is compared with the reference level 34, and the comparison output is derived as a high-level or low-level logic signal.
In the configuration shown in FIG. 3, when the skipping occurs and the output of the absolute value circuit 32 increases and exceeds the reference level 34, the comparison circuit 33
From which a high-level output is derived. Reference level 34
Can be changed externally. Since the sound skipping level differs depending on the size of the scratch 12 formed on the test optical disc 2 and the configuration of the optical disc reproducing apparatus 1, the reference level 3
By appropriately adjusting the value of No. 4, it is possible to perform an appropriate inspection of the scratch resistance performance.

As for the scratches 12 formed on the test optical disc 2, it is desirable that even in the normal optical disc reproducing apparatus 1, several scratches where sound skipping occurs are surely made. Even if such scratches 12 are formed, if sound skipping does not occur, there may be other inconveniences, such as a good scratch resistance performance but a narrow output dynamic range. Further, as the scratches 12, it is desirable to make several scratches where sound skipping does not occur in the normal optical disc reproducing apparatus 1. If skipping occurs due to such scratches 12, it can be determined that the scratch resistance performance of the optical disc reproducing apparatus 1 to be inspected is poor. Further, it is also possible to insert a plurality of scratches 12 having different sizes stepwise. According to the flaws having different sizes stepwise, sound skipping occurs for flaws having a certain size or more, and the degree of flaw resistance can be quantitatively grasped.
Further, in the case of the normal optical disc reproducing apparatus 1, it is also preferable to insert a plurality of scratches of different types, which are scratches 12 at which sound skipping will not occur. If there is a flaw that causes sound skipping, if flaw resistance performance is found to be inferior to a specific type of flaw, it can be effectively determined as information for taking a countermeasure.

FIG. 4 shows an internal configuration of the optical disk reproducing apparatus 1 of FIG. Data recorded on the test optical disk 2 is optically read by the pickup 40. The read data is amplified by the reading circuit 41 and digitally processed by the signal processing circuit 42.
Error correction and the like are performed. The test optical disk 2 is driven to rotate by a motor 43, and the motor 43 is driven by a rotation servo circuit 44. Reading of data from the test optical disk 2 by the pickup 40 is performed by the focus servo circuit 45 and the tracking servo circuit 46.
It is performed under the control of. The self-adjustment circuit 47 includes a microcomputer or the like, and controls the rotation servo circuit 44, the focus servo circuit 45, and the tracking servo circuit 46 based on the output from the signal processing circuit 42. The self-adjustment circuit 47 includes an interface (hereinafter, “I / F”).
A command input according to a standard such as RS-232C is externally input to a serial input terminal 49 via a circuit 48.
Given through. When a command is externally applied to the self-adjustment circuit 47, the self-adjustment mode for inspection is entered.
The adjustment value adjusted by the self-adjustment circuit 47 is derived from the signal processing circuit 42 to the outside. At this time, the output of the signal processing circuit 42 is converted to digital / analog conversion (hereinafter referred to as “D
/ A ") from the circuit 50 to the external output terminal 51. The operation mode for the self-adjustment inspection by the self-adjustment circuit 47 may be configured to be activated according to the operation input from the operation input unit 11 in FIG. The reading of the adjustment value may be performed on the display unit 13.

FIG. 5 shows the operation of the inspection apparatus of the optical disk reproducing apparatus according to the present embodiment. The operation is started from step a1, and an inspection condition is set in step a2. The inspection conditions are stored in, for example, the personal computer 5 of FIG.
It can be stored in an area or the like. When the test optical disk 2 is an MD, writing is possible, so that it is easy to record test conditions in advance.

In step a3, the test optical disk 2 is inserted into the disk insertion portion 10 of the optical disk reproducing apparatus 1 to be inspected.
Insert In step a4, a self-adjustment is performed by inputting a command through the RS-232C serial input terminal 49 or the like. At step a5, an adjustment value is read. By reading the adjustment value via the external output terminal 51, the personal computer 5 in FIG. 1 determines whether the self-adjustment function is operating properly. When it is determined that the self-adjustment function is satisfactorily operating, the process proceeds to step a7, and among the scratches 12 formed on the test optical disk 2, a scratch to be used for a scratch resistance performance test is selected. Since the optical disc reproducing apparatus 1 is determined to have a good self-adjustment function, the scratch 12 can be selected by specifying the position where the scratch 12 is formed by the track. In step a8, it is determined whether or not to apply vibration according to the inspection condition. When the application of the vibration is a condition, the vibration generating device 7 is operated according to the vibration condition in step a9 to perform the vibration. When the application of vibration is not a condition in step a8, or after the vibration is started in step a9, reproduction from the test optical disk 2 is performed in step a10. In step a11, FIG.
It is determined whether or not the sound skipping has occurred by the sound skipping determination device 7, and if the sound skipping has occurred, the count value of the counter 4 is increased in step a12. Step a
When no skipping occurs in step 11, after skipping counting is performed in step a12, the count value is evaluated in step a13. According to the inspection conditions, the count value for a certain period of time is compared with a reference value. For example, when the scratches 12 causing sound skipping are surely selected, it is determined that the scratch resistance performance is good when the number of scratches 12 is equal to the count value. to decide. In the normal optical disc reproducing apparatus 1, when the scratch 12 in which sound skip does not occur is selected, when the count value is 0, the scratch resistance is determined to be good. When flaws 12 having different sizes are selected in stages, it is determined that the flaw resistance is good when the count value is equal to or less than the count value corresponding to the required flaw resistance.

In step a14, according to the inspection conditions,
It is determined whether the item to be inspected has been completed. When it is determined that the inspection item is not completed, step a7
To select a new scratch 12. When it is determined that the inspection has been completed, the inspection for one optical disk reproducing apparatus 1 is ended in step a15. If it is determined in step a6 that the self-adjustment function is not good,
At 16 it is determined that the self-adjustment function is defective, and the inspection ends.

In the above embodiment, the inspection of the self-adjustment function and the inspection of the scratch resistance are performed automatically and consistently, but they may be performed separately. In addition, the inspection of the self-adjustment function can also use the operation input unit 11 and the display unit 13 provided on the front panel of the optical disc reproducing device 1. The display unit 13 is usually used to display a track number of a CD or the like being reproduced or an address such as hour, minute, second, etc., but gradually displays each adjustment value of the self-adjustment at fixed time intervals. And read out to the outside. Further, it is also possible to notify an external signal from the external output terminal 51 as an audio signal.

Further, since the output of the sound skip determination device 3 shown in FIG. 3 can be obtained as a logical value, even if an operator is attached, the scratch resistance performance can be determined without individual differences.

[0022]

As described above, according to the present invention, it is possible to reliably inspect the scratch resistance performance, which indicates the degree of sound skipping when reproducing an optical disc having a scratch.

Further, it is possible to perform a more severe inspection of the scratch resistance performance under the conditions given the vibration.

Further, according to the present invention, since the conditions for the evaluation of the scratch resistance are recorded in advance on the test optical disk to which the scratch is added, the new test conditions for the scratch resistance can be obtained simply by replacing the test optical disk. Can be easily set.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic electrical configuration of an inspection device according to one embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a configuration related to a scratch 12 provided on the test optical disk 2 of FIG.

FIG. 3 is a block diagram showing an electrical configuration of the sound skip determination device 3 of FIG. 1;

FIG. 4 is a block diagram showing an electrical configuration of the optical disc reproducing apparatus 1 of FIG.

FIG. 5 is a flowchart showing an operation of the inspection device of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk reproducing device 2 Test optical disk 3 Sound skipping judgment device 4 Counter 5 Personal computer 6 Display device 7 Vibration generator 11 Operation input unit 12 Scratches 13 Display unit 20 Pit 21 Lens 22 Laser beam 33 Comparison circuit 34 Reference level 40 Pickup 42 Signal processing circuit 43 Motor 44 Rotary servo circuit 45 Focus servo circuit 46 Tracking servo circuit 47 Self-adjustment circuit 49 Serial input terminal 51 External output terminal

Continued on the front page (51) Int.Cl. ⁷ identification code FI G11B 19/02 501 G11B 19/02 501S (58) Investigated field (Int.Cl. ⁷ , DB name) G11B 20/18 G11B 7/26 G11B 19/02

Claims (2)

(57) [Claims] 1. A method for inspecting the scratch resistance of an optical disc reproducing apparatus for optically reading and reproducing information recorded as a digital signal on an optical disc, the method comprising: Insert the added test optical disk to reproduce the recorded information, apply vibration according to the preset conditions, and judge that sound skipping occurs when the distortion included in the reproduction output exceeds the standard level. An inspection method for an optical disc reproducing apparatus, wherein the scratch resistance performance is determined by the following method. 2. The method according to claim 1, wherein the preset condition is recorded on the test optical disk to which the flaw is added in advance.