JP3318900B2 - Optical head automatic inspection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection of the operation state of a two-axis portion of an optical head which performs focusing and tracking by applying electric signals to a focus coil and a tracking coil to displace a bobbin vertically and horizontally. The present invention relates to an automatic optical head inspection device that can be automatically performed.

[0002]

2. Description of the Related Art FIG. 7 is a perspective view schematically showing an example of an optical head used in an optical disk device. The biaxial part 1 of the optical head in FIG. 7 is configured by disposing a magnet 3, an ED arm 4, a bobbin 5, an objective lens 6, a focus coil 7, a tracking coil 8, and the like on a yoke 2, and a rear part of the yoke 2 . Schematic configuration in which an electric signal is supplied to a focus coil 7 and a tracking coil 8 via a flexible wire (not shown) attached to the camera, and the bobbin 5 on which the objective lens 6 is attached is moved up and down, left and right to adjust focusing and tracking. It has become.

In the inspection of the optical head of this type in the manufacturing process of the two-shaft portion, the finished product is manually taken out of the tray in which the assembled product of the two-shaft portion 1 is stored and placed on an inspection base. To give signals to the focus coil 7 and the tracking coil 8 respectively,
The end of the bobbin is magnified and captured by a CCD (Charge Coupled Device) camera, which is displayed on a monitor, and the amount of change in the displayed bobbin front is captured by human eyes to judge pass / fail.

[0004]

However, this type of conventional inspection is a visual sensory inspection and requires skill, and there is a problem that the accuracy of the pass / fail judgment is large and the accuracy is not stable. . In addition, since the task is to keep watching the monitor, the eyes are tired and not suitable for long hours of work. Further, since the two-axis part is completely inspected by hand and is inspected off-line after the assembly of the two shafts is completed, the work efficiency is poor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to enable an automatic inspection without manual operation, eliminate variations in judgment, improve inspection accuracy and improve work efficiency. An object of the present invention is to provide an optical head automatic inspection device that can be achieved.

[0006]

In order to achieve the above object, an optical head inspection apparatus according to the present invention provides an electric signal to a focus coil and a tracking coil, respectively.
In an optical head automatic inspection apparatus having a biaxial portion in which a bobbin to which an objective lens is attached moves in a focusing direction and a tracking direction orthogonal to the focusing direction, a voltage of the electric signal applied to the focus coil and the tracking coil And gradually changing the bobbin in the focusing direction and the tracking direction, respectively.
A tracking drive unit, first detecting means for detecting a moving distance of the bobbin in the focusing direction, second detecting means for detecting an operation state of the bobbin in the tracking direction, and the first detecting means. based on the detected signal, on the movement distance of the focusing direction of the bobbin and a downward travel distance it is checked whether a predetermined distance or more, the focus checking means for determining the quality of the second shaft portion, and said Bobbin moves down
In the state at the lower end position of the distance , power is supplied from the focus / tracking drive unit to the tracking coil, and the second detection means determines whether or not the tracking coil moves smoothly following the gradually changing electric signal. detection
Tracking check means for checking based on the signals to be performed and judging the quality of the two-axis section, respectively.
And a computer incorporated therein. The first has a laser displacement meter as a second detecting means, further the computer and the laser displacement meter
If an A / D converter for digitizing an analog output from the laser displacement meter is provided between the data focus check means and the tracking check means, data processing can be simplified.

[0007]

According to this configuration, it is possible to automatically perform the inspection of the focusing and tracking operations in the two-axis portion of the optical head, and it is possible to measure and determine the quantitative amount, thereby improving workability. There is no individual difference in judgment, and the inspection accuracy is stabilized.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a system configuration diagram of an optical head automatic inspection apparatus shown as one embodiment of the present invention.

The system configuration shown in FIG. 1 is an example of the case of inspecting a partially assembled product of the biaxial portion 1 of the optical head shown in FIG. 7, and includes a focus / tracking drive unit 11, a laser displacement meter 12, and a keyboard 22. And personal computer 1 to which monitor 23 is connected
3, a robot controller 16 for controlling the sequencer 14, the dual-arm robot 15, a mechanical control I / O 17, a D / A conversion board 18, a DIO (digital interface) board 19, etc. D / A conversion board 18, DIO
The boards 19 are each connected to the computer 13 via a bus 20.

At the time of inspection of the assembled product of the biaxial unit 1, the focus / tracking drive unit 11
Contact probe A as a longer jig pin
21, a contact probe B21 is electrically connected to the flexible wire of the assembled product of the biaxial part 1, and a tracking signal from the contact probe A21 and a focus signal from the contact probe B21 to the terminals of the flexible wire. Are supplied respectively.

The tracking signal and the focus signal are transmitted to the focus / tracking drive unit 11.
5HZ, 600 mVpp sine wave signal is generated as a tracking signal, and ± 1 V analog voltage converted by the D / A conversion board 18 is buffered as a focus signal. Are supplied to the contact probe A21 and the contact probe B21 with a drive circuit (not shown) in the focus / tracking drive unit 11.

The focus / tracking drive unit 11 is connected to a computer 13 via a D / A conversion board 18 and a DIO board 19 and a bus 20, and its drive circuit is driven under the control of the computer 13, Under the control, a tracking signal and a focus signal are supplied to the contact probe A21 and the contact probe B21.

The laser displacement meter 12 comprises a focusing laser displacement meter body 24A and a focusing sensor 2 for detecting a change in the focus direction (vertical direction) of the bobbin 5.
5, a low-pass filter 26A, a tracking system laser displacement meter main body 24B, and a tracking sensor 27 for detecting a change in the tracking direction (left-right direction) of the bobbin 5.
And a low-pass filter 26B and an A / D conversion board 28
And so on.

In the laser displacement meter 12, changes in the bobbin 5 detected by the focusing sensor 25 and the tracking sensor 27 are respectively detected by the laser displacement meter main body 24.
A, 24B, and the laser displacement meter main body 24A,
The signal output from 24B is converted to a low-pass filter 26A,
The signal is further converted from analog to digital by the A / D conversion board 28 through the A / D conversion board 28, and is taken into the computer 13 as data.

FIGS. 3 and 4 schematically show a state in which a change in the focus direction (vertical direction) of the bobbin 5 is detected by the focusing sensor 25. FIG. 3 is a side view thereof, and FIG. It is a top view. As shown in FIGS. 3 and 4, a focusing sensor 25 that detects a change in the focus direction (up-down direction) of the bobbin 5 is disposed above the front end portion of the bobbin 5, and emits the laser beam 31 to the front end portion 5a. Irradiate and detect from changes in the amount of light reflected from it.

FIGS. 5 and 6 schematically show a state in which a change in the tracking direction (left-right direction) of the bobbin 5 is detected by the tracking sensor 27. FIG. 5 is a side view thereof, and FIG. It is a rear view. As shown in FIGS. 5 and 6, a tracking sensor 27 that detects a change in the tracking direction (left-right direction) of the bobbin 5 is disposed diagonally forward of the bobbin 5 and has a reference position (a In this embodiment, the laser beam 32 is irradiated to the portion 5b (the portion shown with oblique lines) of the tracking coil 8), and detection is performed based on a change in the amount of light reflected from the portion.

The inspection apparatus is arranged as one of the lines on an automatic assembly line, and when the inspection is performed, the two-axis robot 1 controlled by a robot controller 16 assembles the two-axis unit 1. Finished products are sequentially taken out from a tray (not shown) and inspected.
The product is classified into a K product 29 and a defective product 30 (NG product), and the entire control of these is processed according to a program incorporated in the computer 13. FIG. 2 is a flowchart showing this inspection procedure.

Next, the inspection procedure will be described with reference to FIG. 2 together with the system configuration shown in FIG. First, prior to the inspection, the assembled product of the biaxial unit 1 is taken out of a tray (not shown) by the robot 15 and placed on an inspection base, and further clamped to make the contact probe A21 and the contact probe B21 biaxial. The inspection starts when it is electrically connected to the flexible wire of the assembled product of the part 1.

Then, first, the contact probe B21
A focus signal (voltage) is supplied. here,
The focus current is gradually increased in the positive direction (step S1), and it is checked whether the bobbin 5 moves upward, for example, by 0.8 mm or more (allowable error ± 0.02 mm) (step S2). If it does not move by 0.8 mm or more, it is determined to be defective (NG). Then, the double-arm robot 15 processes the defective product 30 .

On the other hand, if it moves by 0.8 mm or more, it is moved from this position (the position of 0.8 mm) to -0.8 mm (step S3 ). If it does not stay within -0.8 mm, it is defective ( NG). On the other hand, if good, the focus is determined to be appropriate (OK) (step S4),
Proceeding to step S5, a tracking check is performed this time.

In this tracking check, the bobbin 5
While the focus current is applied and remains at the position of -0.8 mm, a tracking signal is supplied from the contact probe A21 to the terminal portion of the flexible wire. Here, the tracking signal supplied from the focus / tracking drive unit 11 is compared with the analog output voltage from the laser displacement meter main body 24A to check whether the movement of the bobbin 5 changes smoothly in the tracking direction. Here, if it does not change smoothly, it is determined to be defective (NG). On the other hand, if you're tracking properly (OK) and determine the constant (step S 6).

[0022] Then, these items are properly being examined (O
K), the double-armed robot 15 processes it as a non-defective product 29 into the non-defective product tray (step S7 ), finishes the inspection of the assembled product of the two-shaft part 1, and determines a new assembled product of the two-shaft part 1. Perform an inspection.

Therefore, according to this embodiment, it is possible to automate the biaxial portion 1 of the optical head, and it is possible to automatically measure and determine the quantitative amount. Also,
Since the machine automatically performs based on the reference data, there is no individual difference in the judgment, and the inspection accuracy is stabilized. Further, by making the inspection process in-line, the working efficiency can be further improved.

[0024]

As described above, according to the optical head automatic inspection apparatus of the present invention, the inspection of the focus sync and the tracking operation in the two-axis portion of the optical head can be performed automatically, and it depends on the manual operation. Since the quantification can be automatically measured and determined without the need, the workability is improved as compared with the conventional method in which a sensory test is performed visually, and there is no individual difference in the determination, and the test accuracy is stabilized.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of an optical head automatic inspection apparatus shown as one embodiment of the present invention.

FIG. 2 is a flowchart illustrating an inspection processing procedure in the apparatus according to the embodiment.

FIG. 3 is a side view showing a focusing detection state by a focusing sensor.

FIG. 4 is a top view showing a focusing detection state by a focusing sensor.

FIG. 5 is a side view showing a tracking detection state by a tracking sensor.

FIG. 6 is a rear view showing a tracking detection state by the tracking sensor.

FIG. 7 is a perspective view schematically showing an example of an optical head used in an optical disk device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 2-axis part 2 Yoke 5 Bobbin 6 Objective lens 7 Focus coil 8 Tracking coil 11 Focus / tracking drive unit 12 Laser displacement meter 13 Computer 15 Dual-arm robot 24A Focusing system laser displacement meter main body 24B Tracking system laser displacement meter main body 25 Focusing sensor (first detecting means) 27 Tracking sensor (second detecting means) 28 A / D conversion board (A / D converter)

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-262622 (JP, A) JP-A-61-199114 (JP, A) JP-A-4-31734 (JP, A) 144127 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 7/22

Claims (3)

(57) [Claims] 1. An optical head automatic inspection apparatus having a biaxial portion in which an electric signal is applied to each of a focus coil and a tracking coil, and a bobbin to which an objective lens is attached moves in a focusing direction and a tracking direction orthogonal to the focusing direction. in a focus / tracking drive unit in which the focusing coil and gradually changing the respective voltages of the electrical signal applied to said tracking coil moves gradually each said bobbin to said tracking direction and the focusing direction, the bobbin First detecting means for detecting a moving distance in the focusing direction, second detecting means for detecting an operating state of the bobbin in the tracking direction, and a signal detected by the first detecting means, Said button
Upward moving distance of the focusing direction of the bottle and a downwardly moving distance is checked whether it has more than a predetermined distance, the focus checking means for determining the quality of the second shaft portion, 及
And the bobbin is at the lower end of the downward movement distance
Then, power is supplied from the focus / tracking drive unit to the tracking coil, and whether or not the tracking coil moves smoothly following the gradually changing electric signal is checked based on the signal detected by the second detection means. The tracking check means for judging the quality of the two-axis portion is programmed and incorporated.
Optical head automatic inspection apparatus characterized by having a computer. 2. The apparatus according to claim 1, wherein said first detecting means and said second detecting means have a laser displacement meter.
Or the optical head automatic inspection device according to 2. 3. An A / D converter for digitizing an analog output from the laser displacement meter between the laser displacement meter and the focus check means and the tracking check means of the computer. The optical head automatic inspection apparatus according to claim 3, wherein: