JPH04351718A - Optical head supporting mechanism - Google Patents

Abstract

PURPOSE:To support an optical head used in an optical disk in the stable state without play. CONSTITUTION:Recessed grooves 31 are provided in two surfaces facing each other of a carriage 24 and an inner yoke 27b, and guide rails 32a to 33b are arranged in corners of these grooves 31. Four guide rails 32a to 33b are brought into contact with a rotating member 34, and a pressing pin 36 having the semispherical front end is elastically pressed to outer guide rails 32b by a coiled spring 37. Since vertical movement of outer guide rails 32b is controlled by the inner yoke 27b, the pressing force of the pressing pin 36 is transmitted to the rotating member 34 as it is, and guide rails 32a to 33b and the rotating member 34 are closely brought into contact with each other, and the carriage 24 is supported in the stable state.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical head support mechanism in an optical recording/reproducing apparatus for recording, reproducing, and erasing information on an optical disk.

0002

2. Description of the Related Art FIG. 4 is a perspective view of a conventional optical disc device, and FIG. 5 is a sectional view taken from direction A in FIG. The optical disc device has an objective lens 2 that forms a light spot on the optical disc 1 for reading and writing signals, and an optical head 3 that is movable in the radial direction of the optical disc 1. This optical head 3 is sandwiched from both sides and driven. It consists of two sets of magnetic circuits 4 symmetrically provided on both sides for the purpose of supporting the optical head 3, and a support portion 5 for supporting the optical head 3. The optical head 3 consists of an actuator 6 to which an objective lens 2 is attached, and a carriage 7 on which the actuator 6 is placed.The carriage 7 has a built-in semiconductor laser light source, a sensor for signal detection, optical components, etc. (not shown). . A drive coil 8 wound around the drive direction of the carriage 7 is attached to both sides of the carriage 7, and a support portion 5 and an inner yoke 9 pass through the inside of the drive coil 8. The magnetic circuit 4 includes an inner yoke 9 and an outer yoke 11 to which a permanent magnet 10 is attached.
are arranged in parallel, and the ends of the inner yoke 9 and the outer yoke 11 are connected by a relay yoke 12 in order to secure the operating space for the drive coil 8. The opposing surfaces of the carriage 7 and the inner yoke 9 are provided with U-shaped concave grooves 13, respectively.
14, and at each corner of the concave grooves 13 and 14, there are two inner guide rails 15 in the shape of a round bar on the carriage 7 side, and two outer guide rails 16 of the same shape on the inner yoke 9 side on the left and right sides. It has been inserted. A plurality of spherical rolling members 17 are provided between the inner guide rail 15 and the outer guide rail 16.
are arranged, and these rolling members 17 support the carriage 7 so as to move smoothly relative to the inner yoke 9. The rolling member 17 is preferably made of non-magnetic material, but is made of steel in consideration of durability. Stoppers 18 are provided at both end edges of the concave groove 13 to prevent the rolling members 17 from falling off, and the rolling members 17 are arranged within the concave groove 13 at regular intervals. , a plurality of holding members 19 are provided at equal intervals.

In the above-described configuration, when a current is passed through the drive coil 8, an electromagnetic force is applied to the drive coil 8 due to the interaction with the magnetic circuit 4. Due to this electromagnetic force, the optical head 3 begins to move in the radial direction of the optical disk 1. At this time, the rolling member 17 smoothly rolls between the inner guide rail 15 and the outer guide rail 16, and the optical head 3 moves relative to the inner yoke 9. Since the resistance to movement in this case is extremely small, the operating force of the optical head 3 can be small.

0004

[Problem to be Solved by the Invention] However, the inner guide rail 15 and the outer guide rail 16 that constitute the support section 5
In order to bring the rolling members 17 into complete contact with each other and obtain a good rolling condition, it is necessary to manually adjust the contact pressure between the members, etc., which increases the number of assembly steps and costs. This problem can be solved by incorporating a pressing mechanism on the carriage 7, but this will lead to an increase in the weight of the movable part.
Furthermore, this results in a decrease in the responsiveness of the device.

An object of the present invention is to provide an optical head support mechanism that is easy to assemble and provides stable support characteristics.

[0006]

[Means for Solving the Problems] An optical head support mechanism according to the present invention for achieving the above-mentioned object allows a movable member on which an optical head is mounted to be freely movable by guide rails provided on both sides along the driving direction. The guide rail is supported, and both ends of the guide rail are elastically pressed toward the moving member.

[0007]

[Operation] The optical head support mechanism having the above structure elastically presses both ends of the guide rail, so that the moving member on which the optical head is mounted comes into close contact with the guide rail, which prevents the optical head from rattling. supported by guide rails.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail based on the embodiments shown in FIGS. 1 to 3. Note that the same reference numerals as in the conventional example indicate the same members.

FIG. 1 is a plan view of an optical head support mechanism according to the present invention, and FIG. 2 is an enlarged sectional view of the main part. The optical head 21 is composed of an actuator 23 on which an objective lens 22 is mounted, and a carriage 24 on which the actuator 23 is mounted and which contains a semiconductor laser light source (not shown), a signal detection sensor, and optical components. Drive coils 25a, 25b are attached to the side surfaces of the carriage 24, and inner yokes 27a, 27b forming part of magnetic circuits 26a, 26b pass through the drive coils 25a, 25b. Permanent magnet 2 arranged parallel to inner yokes 27a and 27b
The outer yokes 29a and 29b to which 8a and 28b are attached are as follows:
Inner yokes 27a, 2 via relay yokes 30a, 30b
7b, forming magnetic circuits 26a and 26b.

Inner yokes 27a, 27b and carriage 24
A concave groove 31 is provided on the opposing surfaces of the inner yokes 27a, 27b, and four outer guide rails 32a, 32b, two on the left and right, are provided at each corner of the concave groove 31 of the inner yokes 27a, 27b.
4 is similarly arranged in the concave groove 31 of the carriage 24.
Inside the book, guide rails 33a and 33b are provided. Outer guide rails 32a, 32b and inner guide rail 33a
, 33b are each interposed with a rolling member 34 made of a steel ball as in the conventional example. Further, the outer guide rail 32a is positioned inward by a positioning pin 35, and both end edges of the two upper and lower outer guide rails 32b abut against a pressing pin 36 whose tip is approximately hemispherical, and the outer guide rail 32a is positioned inward by a positioning pin 35. It is pressed inward by a coil spring 37 attached to the stand.

In this case, the pressing pin 36 is pressed against the outer guide rail 32b by the coil spring 37, and since the tip of the pressing pin 36 has a substantially hemispherical shape, it is evenly spaced against the two outer guide rails 32b. A pressing load can be applied to the The outer guide rail 32b is connected to the inner yoke 27
Since it abuts against the upper and lower edges of the concave groove 31 of b and its movement in the vertical direction is restricted, the rolling member 34 is elastically pressed in the pressing direction of the pressing pin 36.

In this way, the two outer guide rails 3
2b always presses the optical head 21 with a constant force, so the optical head 21 is stably supported without any rattling during movement in the disk radial direction. In addition, since the pressing mechanism is provided outside the optical head 21, the optical head 21
The weight of the optical head 1 is reduced, leading to improved responsiveness of the optical head 21.

FIG. 3 is a sectional view of a pressing portion of another embodiment. The inner yokes 27a, 27b and the carriage 24 are provided with concave grooves 31 as in the previous embodiment, and outer guide rails 32a, 32b and inner guide rails 33a, 33b are arranged in the concave grooves 31, respectively. Rails 32a, 3
2b and the inner guide rails 33a, 33b, the rolling member 3
4 are arranged so as to be able to roll. The pressing member 40 having a protrusion 40a at its tip is arranged so that the protrusion 40a contacts one of the outer guide rails 32b from above, and the coil spring 41 presses the outer guide rail 32b.

[0014] Also in this case, the pressing force generated by the coil spring 41 is transmitted to the rolling member 34 via the outer guide rail 32b. Since the outer guide rail 32b is restricted from vertical movement by the guide groove 31 of the inner yoke 27b, it elastically presses the rolling member 34 toward the carriage 24. Since the rolling member 34 applies a load to the inner guide rails 33a, 33b, the looseness between the concave groove 31, the outer guide rails 32a, 32b, the inner guide rails 33a, 33b, and the rolling member 34 is removed as a whole. It turns out.

[0015]

Effects of the Invention As explained above, the optical head support mechanism according to the present invention provides a mechanism for supporting the optical head while elastically pressing the guide rail, thereby improving the optical head support state that was previously required. Adjustments can be omitted, simplifying the assembly process and reducing costs.

[Brief explanation of drawings]

FIG. 1 is a plan view of an optical head support mechanism.

FIG. 2 is an enlarged sectional view of main parts.

FIG. 3 is an enlarged sectional view of a main part of another embodiment.

FIG. 4 is a perspective view of a conventional optical head support mechanism.

FIG. 5 is a cross-sectional view.

[Explanation of symbols]

21 Optical head 23 Actuator 24 Carriage 27 Inner yoke 28 Permanent magnet 29 Outer yoke 31 Concave groove 32 Outer guide rail 33 Inner guide rail 34 Rolling members 35 Positioning pin 36 Press pin 37, 41 Coil spring 40 Pressing member

Claims (2)

[Claims] 1. A movable member on which an optical head is mounted is movably supported by guide rails provided on both sides along the drive direction, and both ends of the guide rails are elastically pressed toward the movable member. Optical head support mechanism. 2. The optical head support mechanism according to claim 1, wherein a yoke of a magnetic circuit for driving the optical head defines a direction in which the guide rail is pressed.