JPS6326845A - Optical head rocking device - Google Patents

Abstract

PURPOSE:To move a carrier at high speed by moving only a peripheral vertically with respect to the information medium of a guide member so as to rock an optical head, thereby making the weight of the entire carrier light. CONSTITUTION:Only light weight components such as a rocking shaft 10 and a roller 5 being parts of the rocking mechanism of an optical head 2 are placed on the carrier 4 for high speed retrieval and other heavy weight components such as a motor 14 are placed on a stationary side. Furthermore, the vertical movement of a rocking guide shaft 10 rocking the optical head 2 is made nearly 0 at the inner circumference of the information medium 1 to move the peripheral side vertically. Since only light weight components are placed on the carrier 4 in such way, the weight of the carrier 4 is made light and the carrier 4 is moved at high speed and the rocking of the optical head 2 is executed at high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical head swinging device for preventing deformation of an information medium in an optical information recording and reproducing apparatus that optically records and reproduces information on an information medium. .

Since conventional technical information media are generally made of plastic, warpage and the like as shown in FIG. 2 inevitably occur.

In FIG. 2, 1 is an information medium, 17 is a turntable on which the information medium 1 is placed, 18 is a turntable motor for rotating the information medium 1, 19 is an optical head for recording and reproducing signals on the information 6 body 1, and 20 is an optical head. The laser beam from the head 19 to the information medium 1 is the optical axis of the optical head 19.

Generally, the information medium 1 has a warpage as shown in FIG. 2, so the optical axis 30 of the optical head 19 and the surface of the entertainment medium 1 are not perpendicular, resulting in comatic aberration, which causes the laser beam 2
0 also detects the signal of the track adjacent to the desired information track, causing crosstalk on the playback screen. Further, as shown in FIG. 2, the warpage of the information medium 1 is small at the inner circumference and becomes larger toward the outer circumference.

As a countermeasure for removing these crosstalks, there is a correction device shown in FIG. 1 is an information medium, 21 is an optical head for recording and reproducing signals on the information medium 1, 22 is a swinging fulcrum when swinging the optical head 21, and 23 is a swinging fulcrum 22 for swinging the optical head 21.
24 is a motor that drives the screw 23, 25 is a reduction gear, 26 is a swinging direction of the optical head 21, 27 is a transfer table on which the optical head 21 and the swinging device are placed,
28 is a guide roller of the transfer table 27, and 29 is a guide shaft of the guide roller 28.

By rotating the motor 24, the screw 23 is rotated via the reduction gear 25, and the optical head 21 is swung about the fulcrum 22. As a signal for swinging, the vertical state of the information medium 1 and the optical head 21 is detected by a photodetector or the like.

Problems to be Solved by the Invention The problem with this correction device is that since the screw 23, motor 24, and reduction gear 25 as the optical head swinging device are all placed on the transfer table 27, the weight of the transfer table 27 is has become so large that it has become extremely difficult to search for a necessary information track within a short period of time, for example, 0.5 seconds. Therefore, there was a problem that it could not be adopted in places where high-speed searching is required, such as business applications. In addition, the optical head 21 must be oscillated each time the optical head 21 is transferred to the inner or outer periphery of the information medium 1, and the oscillation must be performed in a short period of time in accordance with the search time. There were problems with the lifespan, rocking speed, etc.

Means for Solving the Problems The present invention improves the crosstalk caused by warping of the information medium, and also solves the drawbacks of the conventional example, such as difficulty in high-speed retrieval and problems in terms of service life. In order to improve
The transfer table that performs high-speed search operations is configured to carry only light parts such as rollers and swing shafts, which are part of the swing mechanism of the optical head, and other heavy motors and the like are mounted on the fixed side. The vertical movement of the swing guide shaft that swings the information medium is approximately 0'' on the inner circumferential side of the information medium, and the vertical movement is made on the outer circumferential side of the information medium.

Function As mentioned above, since only lightweight parts are placed on the transfer table, the transfer table as a whole can be made lightweight. Therefore, the transfer table can be moved at high speed, and the optical head can be oscillated as originally intended. . In addition, since the swing guide shaft moves up and down on the outer circumference, the inclination of the optical head is small on the inner circumference and large on the outer circumference, making it easy to match the inclination to the warp of the information medium.

Example Embodiments will be described in detail below based on the drawings.

FIG. 1 shows the configuration of an optical head swinging device according to an embodiment of the present invention. In FIG. 1, 1 is an information medium, 2 is an optical head, 3 is a swinging fulcrum that is a fulcrum when swinging the optical head 2, and 4 is a transfer table on which the optical head 2 is placed, and the swinging fulcrum 3 is used to provide light. It supports head 2. 5 is a guide roller that guides the transfer table 4, and 6 is a guide shaft of the guide roller 6. The guide shaft 6 is attached to the transfer base 7.

Reference numeral 8 denotes a transfer drive unit that moves the transfer table 4 in the radial direction of the information medium 1 along the guide shaft 6, and in this embodiment, it is composed of a linear motor.

Reference numeral 9 denotes a swinging roller, which is rotatably provided on the optical head 2 and guided by a swinging guide shaft 1o. Further, the swinging guide shaft 10 is attached to the transfer base 7 by a coaxial guide shaft 12 at one end and an eccentric shaft 11 at the other end.

Reference numeral 14 denotes an electric guide actuator, which rotates the swinging guide shaft 10 about the eccentric shaft 11 via the reduction gear 13.

The eccentric shaft 11 is provided on the outer circumferential side of the information medium 1, and the coaxial guide shaft 12 is provided on the inner circumferential side of the information medium 1.

In operation, if the information medium 1 is sagging at the outer periphery due to warping or the like, the optical axis of the optical head 2 and the reproduction surface of the information medium 1 must be made perpendicular, so the optical head 2 must be rotated in the direction of arrow 15. It is necessary to move. Therefore, the guide drive motor 14 drives the swinging guide shaft 1o through the reduction gear 13.
is rotated in the direction of arrow 16, the guide surface is lowered, and the swinging roller 9 is moved downward, resulting in the optical head 2 being rotated in the direction of arrow 15.
Rotate it in the direction of. Further, since the swinging guide shaft 10 has a coaxial guide shaft 12 at the negative end and an eccentric shaft 11 at the other end, the guide surface moves up and down on the side of the eccentric shaft 11 provided on the outer circumferential side of the information medium 1. , coaxial guide shaft 1 provided on the inner circumferential side
It does not move up and down on the 2nd side.

Therefore, the inclination of the optical radar 2 does not incline on the inner circumferential side, and the amount of inclination increases as it goes toward the outer circumferential side. This corresponds to the amount of warpage of the information medium 1 shown in FIG. 2, and if the - degree inclination is matched, there is no need to correct the inclination until the information medium 1 is replaced.

In this embodiment, the swing guide shaft 10 is rotated, but the guide portion only needs to move up and down as in this embodiment, and the rotation method is not critical.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) Has a swinging mechanism to eliminate crosstalk,
Moreover, high-speed search is possible.

(2) Even if the information medium has distortion such as warpage, signal crosstalk caused by the distortion can be removed.

(3) Since the amount of inclination due to rocking almost matches the amount of warp of the information medium, which increases along the outer circumference, it is preferable to match the tilt by -degrees, so there is no need for high-speed rocking.

(4) Furthermore, because the number of swings is reduced due to the above-mentioned reason, there is no problem with the lifespan of the motor, etc.

[Brief explanation of the drawing]

Fig. 1 is a side view of an optical head swinging device according to an embodiment of the present invention, and Fig. 2 shows the relationship between the warpage of the information medium and the optical head.
FIG. 3 is a side view of a conventional optical Herad oscillating device. 1. Information medium, 2. Optical head.
3... Swinging fulcrum 1, 4... Transfer table, 5...
...Guide roller, 6...Guide shaft, 7...
...Transfer base, 8...Transfer, drive section, 9...
... Swinging roller, 10... Swinging guide shaft,
13... Reduction gear, 14... Guide drive motor. Name of agent: Patent attorney Toshio Nakao and one other person? −
Optical head 3-11o master η branch 7 East, 4°-Sugi-1 unit Fig. 2? θ /q Figure 3

Claims (1)

[Claims] an optical head for recording and reproducing information on an information medium; a transfer table on which the optical head is placed; a guide roller provided on the transfer table; a guide shaft of the guide roller provided on a transfer base; a swing shaft attached to the transfer table so as to be swingable about an axis parallel to the medium surface and perpendicular to the transfer direction of the optical head; and a transfer drive unit that transfers the transfer table;
The guide member includes a swinging roller provided on the optical head, a guide member for the swinging roller provided on the transfer base, and a guide drive unit provided on the transfer base for driving the guide member. An optical head rocking device characterized in that the optical head is rocked by vertically moving only the outer peripheral side with respect to the information medium.