JP2002109780A - Optical head test apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical head test apparatus that can test an optical head device under the condition of obtaining the same characteristics as that obtainable when incorporated into an actual optical recording medium drive apparatus. SOLUTION: The apparatus for testing the optical head device 106 controls one or more functions out of focusing servo control, tracking servo control and spindle servo control, using control circuits (a PCB mounted thereon a controller, a servo circuit, a digital circuit, etc.), of the optical disk drive apparatus 100 into which the device 106 to be tested is to be incorporated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an optical disc (CD,
An optical recording medium driving device that optically reproduces or reproduces / records information from an optical recording medium such as a CD-R / RW, DVD, DVD-R / W, or a magneto-optical disk (MO, MD, etc.). The present invention relates to an inspection device for inspecting an optical head device as a component.

[0002]

2. Description of the Related Art An optical disk drive, which is one type of optical recording medium drive, controls the rotation of an optical disk, the position and focus of an optical head device by using a focus servo, a tracking servo, a spindle servo, and the like. The data is read (reproduced) or written (recorded) by irradiating the disk surface with a laser beam.
The optical head device is an expensive component, and the reproduction / recording accuracy of the optical disk drive depends on the performance of the optical head device. Therefore, an inspection device for inspecting this performance is required. The configuration of an inspection device for inspecting an optical head device is almost the same as that of an optical disk drive device, but in a conventional inspection device, control circuits such as focus servo and tracking servo are configured by circuits dedicated to each inspection device. (JP-A-9-054952, JP-A-11-154337, JP-A-11-154337)
185262, JP-A-11-195237, etc.). for that reason,
In many cases, the characteristics of the optical head device when inspected by the inspection device are different from the characteristics when the optical head device is assembled to the optical recording medium driving device.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to integrate an optical head device into an actual optical recording medium driving device. It is an object of the present invention to provide an optical head inspection apparatus capable of performing an inspection in a state where the same characteristics as those in the state are obtained.

[0004]

According to a first aspect of the present invention, there is provided an optical head device for recording information on an optical recording medium or reproducing information recorded on the optical recording medium. An inspection apparatus for performing the control function of at least one of focus servo, tracking servo, and spindle servo of the inspection apparatus by using a control circuit of an optical recording medium driving device in which an optical head device to be inspected is incorporated. It is characterized in that it is configured to be realized by. Here, the control circuit of the optical recording medium driving device in which the optical head device to be inspected is incorporated is the optical recording medium driving device in which the optical head device to be inspected or an optical head device of the same type is incorporated and commercialized. Means a control circuit incorporated in an optical recording medium drive having the same type, specifically, the same model number. In this case, the optical head to be inspected and the control circuit used for the inspection have a one-to-one correspondence or a plural-to-one correspondence. According to a second aspect of the present invention, in the optical head inspection apparatus according to the first aspect, when inspecting an information reproducing function by the optical head, the optical output of the optical head device is temporally constant. A current supplied to a light source element of the optical head device is controlled using the control circuit. According to a third aspect of the present invention, in the optical head inspection apparatus according to the first or second aspect, when inspecting an information recording function of the optical head, the optical output of the optical disk is time-dependent according to information to be recorded. The current supplied to the light source element of the optical head device is controlled using the control circuit in order to change the current value.
According to a fourth aspect of the present invention, in the optical head inspection apparatus according to any one of the first to third aspects, an address position on the optical recording medium accessed by the optical head is detected, and the predetermined position is determined in advance. When the optical head reaches the address position, the optical head has a control function of moving the optical head to an address position on the inner peripheral side on the optical recording medium.

[0005] Further, the invention described in claim 5 is based on claims 1 to
5. The optical head inspection apparatus according to any one of 4 to 4, wherein the control circuit has a function of performing at least one of offset adjustment and gain adjustment of the optical head. According to a sixth aspect of the present invention, in the optical head inspection apparatus according to the fifth aspect, an interface function of outputting data of an adjustment value by the control circuit to an external device is provided. According to a seventh aspect of the present invention, in the optical head inspection apparatus according to the fifth or sixth aspect, the inspection of the optical head device is implemented by actually incorporating the optical head device into a product. And a configuration in which the data of the adjustment value can be recorded in a nonvolatile memory provided in the optical head device or the control circuit. Here, the control circuit of the optical recording medium driving device, which is actually incorporated and commercialized, not only has the same model number and the like, but also the optical head itself to be inspected is actually incorporated. It refers to a control circuit incorporated in the optical recording medium drive that is commercialized and shipped. Therefore, in this case, there is a one-to-one correspondence between the optical head to be inspected and the control circuit used for the inspection.
The invention according to claim 8 is the optical head inspection apparatus according to claim 5 or 6, wherein the inspection of the optical head device is performed using a common control circuit without replacing the control circuit for each inspection. When performing, that is, when inspecting a plurality of optical head devices using one control circuit, based on the characteristics of the common control circuit measured in advance, based on the characteristics of the common control circuit, the inspection target The optical disc drive is characterized in that the adjustment value for each optical head is obtained, and the data of the adjustment value can be recorded in the nonvolatile memory of each optical head device. In this case, the optical head to be inspected and the control circuit used for the inspection have a plural-to-one correspondence.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration example of a general optical disk drive (reproduction / recording apparatus). From the external device (for example, personal computer) 200 to the optical disk drive 10
0 to the interface controller 1
01 receives the command, and the controller 10
Report to 2. The controller 102 interprets this command, and responds to the command request according to the command.
And sends a report to an external device through the interface controller 101. Optical disk 30
When information is recorded in 0, information from the external device 200 is temporarily stored in the buffer memory 104 via the interface controller 101 and the digital circuit 103. The digital circuit 103 attaches an error correction code to the data, adds a synchronization signal, and converts the data into a modulation code. Then, the output of the digital circuit 103 is converted into an analog signal and input to the analog circuit 105. The analog circuit 105 controls the drive current of the spindle motor 108 as the rotation drive unit of the optical disc 300 and the LD of the optical head device 106 according to the input signal.
(Laser diode) drive current. Thus, the light emission of the LD is controlled, and information is recorded on the optical disc 300. At that time, the optical head device 106 receives the reflected light from the optical disk 300 by a PD (photodiode) and sends the received light signal to the analog circuit 105. The analog circuit 105 generates a focus error signal, a tracking error signal, and the like based on the light receiving signal, and inputs the generated signal to the servo circuit 107. The servo circuit 107 controls the optical head device 10 based on a signal from the analog circuit 105.
6, the focus, the rotation of the spindle motor 108, and the like. When reproducing information recorded on the optical disk 300, the output of the optical head device 106 is binarized by the analog circuit 105, clock is extracted by applying a PLL, and synchronization detection, demodulation, error correction, etc. are performed by the digital circuit 103. To reproduce the information, and the buffer memory 1
Store in 04. Then, the interface controller 1
01 to the external device 200.

Next, an optical head inspection apparatus will be described. FIG. 2 is a main part configuration diagram showing an example of an embodiment of the optical head inspection apparatus according to the present invention. Although the basic configuration of the optical head inspection device 400 is basically the same as the configuration example of the general optical disk drive device 100 shown in FIG. 1, since the inspection device is an inspection device, a pass / fail judgment can be made by extracting an inspection signal. And a measuring circuit 401 for performing such operations. Further, the optical head inspection apparatus 400 includes an interface controller 101,
A circuit board (PCB) on which the controller 102, the digital circuit 103, the buffer memory 104, and the servo circuit 107 are mounted is mounted. That is, the optical head inspection apparatus 400 performs control functions such as focus servo, tracking servo, and spindle servo using a control circuit 402 having the same configuration as the optical disk drive apparatus 100 in which the optical head apparatus 106 to be inspected is incorporated. It is realized by. However, the optical head inspection device 4
The 00 control circuit 402 performs operation control for inspection, which is not performed in normal recording and reproducing operations. At the time of inspection, the control circuit 402 controls a current flowing through the LD of the optical head device 106 based on a light receiving signal from the PD of the optical head device 106. When performing the reproduction inspection, control is performed so that the power of the light emitted from the optical head device 106 becomes constant. Further, when performing a recording inspection, information is recorded by changing the light emission power of the LD as shown in FIG. 3, for example, by changing the current flowing through the LD. When inspecting the optical head device 106, the same optical disk 300
It is necessary to check the characteristics at the same location (address) above. However, since the optical disk 300 usually has a spiral groove or data array, if nothing is done, the optical head device 106 moves from the inner circumference to the outer circumference. Therefore, as shown in FIG. 4, when a predetermined address is reached, control is performed to cause the optical head device 106 to jump inward, so that characteristics at the same position (address) can always be inspected with good reproducibility. . The control circuit 402 also performs such operation control peculiar to the inspection.

As described above, the control functions of the optical head inspection apparatus 400 such as focus servo, tracking servo, and spindle servo are controlled by the optical head apparatus 10 to be inspected.
6 is implemented using the control circuit of the optical disk drive 100 in which the optical head 6 is incorporated, so that the optical head device 106 can be inspected in a state where the same characteristics as those in the actual optical disk drive 100 can be obtained. can do. Further, the optical head device 106 and the control circuit of the optical disk drive 100 have variations in offset and gain. For this reason, the control circuit of the optical disk drive 100 normally has an adjustment circuit for absorbing variations. Therefore, if the variation is within the adjustment range, it is not necessary to determine that the optical head device 106 is defective even if the characteristics are slightly varied. Therefore, before performing the inspection, the control circuit 402 adjusts the variation of the offset and the gain, and then performs the inspection. As a result, the inspection can be performed in a state close to the state of use in an actual device. The adjustment value at this time is stored in the optical head inspection device 40.
0, and once stored and held in the external device 200, the information can be transplanted and used in the control circuit of the optical disk drive 100 in which the optical head device 106 is assembled. Further, the inspection of the optical head device 106 is performed as follows.
This is implemented using the control circuit 402 of the optical disk drive device 100 which is actually incorporated and commercialized, and the data of the adjustment values once stored and held in the external device 200 are transferred to the optical head via the interface controller 101. By recording the data in the non-volatile memory provided in the device 106 or the control circuit 402, the inspection can be performed in the actual use condition. When the inspection of the optical head device 106 is performed using a common control circuit without replacing the control circuit 402 for each inspection,
That is, when inspecting a plurality of optical head devices 106 while fixing the control circuit 402, the control circuit 402 measured in advance is used.
The adjustment value for each optical head device 106 to be inspected is obtained based on the characteristics of the optical head devices 106, and the data of the adjustment value is recorded in the nonvolatile memory of each optical head device 106, so that the variation between the inspection devices is reduced. Can be canceled. Although an optical recording medium has been described here as an example of an optical recording medium, the present invention does not depend on the type of the medium. That is, the same effect can be obtained with other media such as a memory card and a magneto-optical medium.

[0009]

As described above, the optical recording medium inspection apparatus of the present invention incorporates at least one of the focus servo, tracking servo, and spindle servo control functions into the optical head apparatus to be inspected. Is realized by using the control circuit of the optical recording medium driving device, so that the optical head device to be inspected can be obtained in a state where the same characteristics as those in the actual optical recording medium driving device can be obtained. Can be inspected.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration example of a general optical disk drive (playback / recording device).

FIG. 2 is a main part configuration diagram showing an example of an embodiment of an optical head inspection apparatus according to the present invention.

FIG. 3 is a diagram exemplifying a temporal change of a light emission power of an optical head device when performing a recording inspection.

FIG. 4 is an explanatory diagram exemplifying a method of controlling the position of an optical head device so that characteristics at the same position (address) on an optical disk can always be inspected with good reproducibility.

[Explanation of symbols]

Reference Signs List 100 optical disk drive device, 101 interface controller, 102 controller, 103 digital circuit, 104 buffer memory, 105 analog circuit, 106 optical head device, 107 servo circuit, 1
08 Spindle motor, 200 External device, 300
Optical disk (optical recording medium), 400 optical head inspection device, 401 measuring circuit, 402 control circuit

Claims (8)

[Claims] 1. An inspection apparatus for inspecting an optical head device for recording information on an optical recording medium or reproducing information recorded on the optical recording medium, comprising: a focus servo, a tracking servo, and a spindle servo of the inspection apparatus. An optical head inspection apparatus, wherein at least one of the control functions is realized by using a control circuit of an optical recording medium driving device in which an optical head device to be inspected is incorporated. 2. A control circuit according to claim 1, wherein said control circuit controls a current supplied to a light source element of said optical head device so that an optical output of said optical head device becomes constant with time when inspecting an information reproducing function of said optical head. 2. The optical head inspection apparatus according to claim 1, wherein the optical head inspection apparatus is configured to be used and controlled. 3. When inspecting an information recording function of the optical head, a current supplied to a light source element of the optical head device is changed in order to change an optical output of the optical disk with time according to information to be recorded. The optical head inspection apparatus according to claim 1, wherein the control is performed using the control circuit. 4. An address position on the optical recording medium accessed by the optical head is detected, and when the optical head reaches a predetermined address position, the optical head is moved to a further inner peripheral address position on the optical recording medium. The optical head inspection device according to any one of claims 1 to 3, further comprising a control function of moving the optical head. 5. The optical head inspection apparatus according to claim 1, wherein the control circuit can perform at least one of offset adjustment and gain adjustment of the optical head. 6. An optical head inspection apparatus according to claim 5, further comprising an interface function of outputting data of an adjustment value by said control circuit to an external device. 7. The optical head device is inspected by using a control circuit of the optical recording medium driving device in which the optical head device is actually assembled and commercialized, and the data of the adjustment value is converted into the optical head device. 7. The optical head inspection device according to claim 5, wherein the optical head inspection device is configured to be able to record in a nonvolatile memory provided in the control circuit. 8. When the inspection of the optical head device is performed using a common control circuit without replacing the control circuit for each inspection, based on characteristics of the common control circuit measured in advance, 7. The optical device according to claim 5, wherein an adjustment value for each optical head to be inspected is obtained, and data of the adjustment value can be recorded in a nonvolatile memory of each optical head device. Head inspection device.