JPH11144408A - Optical pickup feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup feeder which protects an optical pickup from a shock due to falling or the like. SOLUTION: An abutment part 8 is provided on a feed nut 3 so that the abutment part 8 is abutted against a chassis 4 and slides in the direction of radius of a disk when screwing of a lead screw 2 with the feed nut 3 is released in the shock development. The abutment part 8 is moved along a cam formed on the chassis 4, thus restoring screwing. Since the level of a falling shock applied to the optical pickup is reduced by sliding friction, the shock resistance performance of the device can be significantly improved with a simple structure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus for recording / reproducing information on / from a recording medium such as a magneto-optical disk and an optical disk, and more particularly to an optical pickup feeding apparatus.

[0002]

2. Description of the Related Art Conventionally, when recording or reproducing a signal from a recording medium such as a magneto-optical disk or an optical disk, a drive method using a lead screw is generally adopted as a means for conveying an optical pickup or a magnetic head in a radial direction. I have.

In this driving method, a DC motor or a stepping motor is a driving source. In the case of a DC motor, the speed is reduced by a gear from the rotating shaft of the motor to the lead screw. In the case of a stepping motor, the motor shaft and the lead screw are connected. Direct drive is performed by integrating them. A nut is screwed into the lead screw, and the rotational motion is converted to a linear motion. Since the nut is fixed to the optical pickup via a leaf spring, the rotation speed of the lead screw becomes the feed speed of the optical pickup. The moving time of the optical pickup is related to the access time at the time of reproducing the disc.

An example of the above-described conventional optical pickup feeder will be described below with reference to FIG. The rotation of the traverse motor 29 carried on the chassis 24 is reduced by the intermediate gear 30b and the drive gear 30c from the motor gear 30a press-fitted to the rotating shaft.
The rotational movement of the lead screw 22 into which 0c is press-fitted is
The movement is converted into a linear motion by a feed nut 23 screwed to the lead screw 22.

The feed nut 23 is fixed to the optical pickup 21 via a leaf spring 25. The optical pickup 21 is slidably supported in parallel with the optical disc 31 by a main shaft 32 and a sub-shaft 33 fixed to the chassis 24. The optical pickup 21 is controlled by the management information written on the optical disc 31. The optical pickup 21 can be conveyed to the designated position in the radial direction of the optical disk while reading the track on the optical disk 31.

FIG. 12 is a sectional view of a conventional optical pickup feeder. In FIG. 12, a feed nut 23 screwed to a lead screw 22 is urged by a leaf spring 25 from the back with a constant force. The spiral groove 26 of the lead screw is required to have high precision so that power transmission loss and vibration do not occur as much as possible between the spiral groove 26 formed on the lead screw 22 and the tooth mold 27 formed on the feed nut. 23 uses a resin material having high slidability.

[0007]

However, in the conventional optical pickup feeding device as described above, although the nut is pressed by the lead screw by the leaf spring, when the device is subjected to a strong impact such as dropping, it is instantaneous. The warp of the leaf spring causes the nut and the lead screw to separate, causing the optical pickup to move with acceleration and colliding with support members such as the outer wall of the chassis, thereby damaging the optical pickup. , Causing performance degradation and failure.

Particularly, in an apparatus having a magnetic head (not shown) that moves integrally with an optical pickup, such as an MD recorder, which is used in a magnetic field modulation system, the core of the magnetic head needs to be resiliently brought into contact with the disk surface. Since the suspension has a weak strength, the suspension is deformed by a drop impact, the core is misaligned, and normal recording / reproducing operations cannot be performed. Had.

Further, as described in Japanese Patent Publication No. 5-81681, a feeder provided with a stopper so that the feed nut does not come off the lead screw is disclosed, but it is demanded for portable equipment. In the case of such a high impact value, the tooth formed on the nut is damaged by the impact, so that this configuration is also limited.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide an optical pickup feeding device that reduces shock so that the shock applied to the entire feeding device does not damage the optical pickup or the magnetic head. It is.

[0011]

In order to solve the above-mentioned problems, an optical pickup feeder according to the present invention comprises an optical pickup for recording or reproducing information recorded on a disk, and a lead driven by rotation of a traverse motor. A screw, a feed nut attached to the optical pickup and conveyed in a radial direction of the disk by being screwed into a lead screw, and a chassis carrying the traverse motor and the lead screw; A nut is provided with a contact portion formed to face the chassis at a predetermined distance. When an impact occurs, the screwing of the feed nut and the lead screw is separated, and the optical pickup moves in the radial direction of the disk. The contact surface of the contact portion with the chassis, and the contact portion of the chassis. And wherein the sliding abutting surface.

Further, the feed nut is provided with a contact portion formed so as to face the chassis at a predetermined distance, so that when the impact occurs, the screw engagement between the feed nut and the lead screw is separated, and the optical pickup is mounted on the disk. When moved in the radial direction, the surface of the contact portion where the chassis abuts and the surface where the contact portion of the chassis abuts are slid, and in a range where the abutment portion slides, A groove-shaped or protrusion-shaped cam whose both ends are inclined in a direction approaching the lead screw is formed on the chassis, and when an impact occurs,
The screwing of the feed nut and the lead screw is separated,
When the optical pickup moves in the radial direction of the disk, the contact portion slides according to the shape of the cam, thereby returning the screwing between the feed nut and the lead screw. is there.

With the above arrangement, when an impact such as a drop occurs in the contact portion device of the feed nut, the optical pickup is
The frictional sliding between the contact portion of the feed nut and the chassis causes the speed to gradually decrease. Further, since the feed nut moves along the cam by the cam formed on the chassis, the screw engagement between the feed nut and the lead screw can be quickly returned.

[0014]

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS.

FIG. 1 is a side view showing a normal operation of the optical pick feeder, FIG. 2 is a side view showing an impact, FIG. 3 is a front view showing a normal operation, FIG. 4 is a front view showing an impact, and FIG. Is a plan view of the optical pickup feeding device, and FIG. 6 is an exploded perspective view of the optical pickup device.

1 and 2, reference numeral 1 denotes an optical pickup, 2 denotes a lead screw, 3 denotes a feed nut, 4 denotes a chassis, 5 denotes a leaf spring, and 8 denotes a contact portion. 3 and 4, reference numeral 6 denotes a groove of the lead screw, and reference numeral 7 denotes a tooth form of the feed nut. In FIG. 5, 9 is the outer diameter of the optical disk, 10 is a traverse motor, 11a is a motor gear, 11b is a drive gear, 12 is a main shaft, and 13 is a sub shaft.

The operation of the above configuration will be described below. As shown in FIG. 5, the rotation of the traverse motor 10 carried on the chassis 4 is reduced by the motor gear 11a press-fitted to the rotating shaft and the drive gear 11b, which is a worm gear, and the rotation of the lead screw 2 into which the drive gear 11b is press-fitted. Rotation is transmitted.

Since the feed nut 3 screwed to the lead screw 2 is fixed to the optical pickup 1, the optical pickup 1 is conveyed in the radial direction of the optical disk 9 according to the rotation of the lead screw 2. The optical pickup 1 is supported by a main shaft 12 and a sub shaft 13 fixed to the chassis 4 so as to be slidable parallel to the optical disk 9 at a predetermined distance. At the time of access, the traverse motor 10 is controlled according to the management information written on the disk 9.
Is driven, and the optical pickup is transported to the designated position while counting the tracks on the disk 9.

As shown in FIG. 1, the feed nut 3 is fixed to the lead screw 1 by a leaf spring 5 from the back with a constant force.
Of the spiral groove 6. The urging force applied to the lead screw 2 is set so as to minimize power transmission loss and vibration between the spiral groove 6 and the teeth 7 formed on the feed nut 3. High precision is required for the angle of the spiral groove 6 formed in the lead screw 2 and the deflection during rotation. The feed nut 3 is made of a resin material having high slidability.

As shown in the exploded perspective view of FIG. 6, the assembled structure is such that the feed nut 3 and the leaf spring 5 of the molded product are fixed to the optical pickup 1 with the screws 14 positioned respectively. The inclination angle of the teeth 7 of the feed nut 3 is set so that the angle deviation at the time of screwing is as small as possible with respect to the inclination angle of the spiral groove 6 of the lead screw 2 positioned parallel to the main shaft 12.

When a large impact is generated due to dropping of the apparatus, the engagement between the spiral groove 6 of the lead screw 2 and the teeth 7 formed on the feed nut 3 is disengaged by the elastic deformation of the lead screw 2 and the leaf spring 5. The projection 8 formed on the surface opposite to the engagement portion of the feed nut
2, the kinetic energy of the optical pickup 1, which tends to move in the radial direction of the disk 9, as shown in FIG. The speed at the time can be gradually stalled.

The distance d1 between the projection 8 and the mechanical chassis 4 in a normal state is set so that the tip of the lead screw and the tip of the feed nut come into contact with each other just when they come off. Assuming that the tooth engagement amount is d2, d1 ≧ d2. The upper limit of the separation amount d1 is also affected by the load and shape of the leaf spring, but is set so that the deflection amount of the leaf spring 5 and the deflection amount of the feed nut 3 are within the elastic deformation range so as not to be deformed upon impact. .

The shape of the projecting portion 8 is effective by increasing the contact area so that the contact portion can contact the chassis 4 as much as possible. Further, a plurality of protrusions 8 may be provided.

The chassis 4 is made of not only metal material but also
The same is applied to resin, and the surface of a cabinet or the surface of an electric board that covers the exterior of the device may be used instead of the chassis 4.

As described above, according to the present embodiment, when an impact such as a drop occurs in the apparatus, the impact applied to the optical pick or the magnetic head can be reduced with a simple configuration. (Embodiment 2) Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described in detail with reference to FIG. FIG. 7 is similar to FIG.
FIG. 2 shows a front view of the optical pickup feeding device.

In this embodiment, the feed nut 3 of the chassis 4
A urethane rubber sheet 15 as a viscoelastic body is adhered to the area where the projection 8 abuts, and the rubber having a high friction coefficient absorbs the shock generated in the optical pickup when the shock occurs. Further, since the rubber sheet 10 is elastically deformed in a direction in which the feed nut 3 is detached from the lead screw 2, the impact value of the feed nut 3 itself can be suppressed, and the effect is increased. Further, the rubber sheet may be attached to only the protrusion 8 or to both of the chassis.

According to the present embodiment, when an impact such as a drop occurs in the apparatus, the impact applied to the optical pick or the magnetic head can be reduced with a simple configuration. (Embodiment 3) Next, in a third embodiment of the present invention, a urethane-based coating agent having a high friction coefficient is applied to at least one of the surface of the chassis and the contact portion of the feed nut at the position where the rubber sheet shown in FIG. Apply to. In the case of a coating agent, a stable slip prevention effect can be obtained because unevenness and positional variation due to attachment or the like are hard to occur. Of course, you may apply | coat to only a protrusion part or both.

According to the present embodiment, when an impact such as a drop occurs in the apparatus, the impact applied to the optical pick or the magnetic head can be reduced with a simple configuration. (Embodiment 4) Next, a fourth embodiment of the present invention will be described with reference to FIG. In this embodiment, the feed nut and the chassis have frictional resistance by forming irregularities on the surface of the chassis in the area where the protrusion of the feed nut abuts. For example, in the case of a chassis, a shape that generates a high frictional force is possible by forcibly roughening the surface by staring or rolling with press working. . Since irregularities can be created in the processing step of the chassis, it can be performed without adding components. For the feed nut,
The effect is improved by forming irregularities in the same manner as the chassis.

According to the present embodiment, when an impact such as a drop occurs in the apparatus, the impact applied to the optical pick or the magnetic head can be reduced with a simple configuration. (Embodiment 5) Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 9 is a front view of the optical pickup feeding device of the present invention. 17 is a cam formed on the chassis, 3a is the position of the feed nut when located at the center of the disk, 3b is the outer side, and 3c is the position of the feed nut when the optical pickup is moved to the inner side. The optical pickup and the leaf spring are not shown. Further, two contact portions 8 of the feed nut are provided for stabilization. The cam 17 has a protruding shape that is smoothly inclined in a range in which the contact portion 8 of the feed nut 3 can slide on the chassis 4 and in which both ends approach the lead screw.

When an impact occurs, the screwing between the feed nut 3 and the lead screw 2 is released, and when the optical pickup 1 moves in the radial direction of the disk, the contact portion 8 slides according to the shape of the cam.

The cam has a smooth shape with inclined surfaces at both ends.
For example, when the chassis is formed by composite molding, it can be formed of resin. Further, the cam itself may be formed in a resin spring shape and bend in the separating direction, so that the impact on the feed nut can be reduced. Also, by attaching sheet metal bending and leaf springs,
A cam may be formed.

The surface of the cam is the same as in Examples 2 to 4.
By using a material that generates a high frictional force or by performing processing, the moving speed of the optical pickup can be reduced, so that the impact at the time of returning to screwing can be reduced. (Embodiment 6) Next, FIG. 10 shows a sixth embodiment of the present invention. A cam groove 18 is formed in the chassis 4. When the device needs to be miniaturized, it can be easily formed by forming a groove in the chassis 4. Other configurations are first
This is the same as the embodiment.

According to the present invention, the screwing of the feed nut and the lead screw can be quickly restored even if an impact occurs during the performance.

[0034]

As described above, in the optical pickup feeding device of the present invention, when an impact such as a drop occurs in the contact portion device of the feed nut, the optical pickup moves the contact portion of the feed nut and the chassis to the disc. By sliding while rubbing in the radial direction, it gradually decelerates, so that even if it receives a shock such as dropping, the optical pickup does not travel quickly and collide with the support member such as the outer wall of the chassis. . Thereby, the performance of the device against drop impact is improved.

Further, since the feed nut moves along the cam by the cam formed on the chassis, the screwing of the feed nut and the lead screw is restored, and the optical pickup is moved to the inner and outer circumferences by the impact. In addition, the feed nut does not mesh with the lead screw, so that it is possible to prevent the feed nut from climbing.

In the future, with the miniaturization and higher density of the device,
Degradation or breakage of the apparatus due to a drop impact is a major problem, but this method can greatly reduce the drop impact value received by the optical pickup with a simple configuration.

[Brief description of the drawings]

FIG. 1 is a side view of a main part of an optical pickup feeding device according to an embodiment of the present invention during normal operation.

FIG. 2 is a side view of FIG. 1 when an impact occurs.

FIG. 3 is a front view of FIG. 1;

FIG. 4 is a front view of FIG. 2;

FIG. 5 is a plan view of an optical pickup feeding device according to the embodiment of the present invention.

FIG. 6 is an exploded perspective view of a main part of an optical pickup feeding device according to an embodiment of the present invention.

FIG. 7 is a front view of a main part of an optical pickup feeding device according to an embodiment of the present invention.

FIG. 8 is a front view of a main part of the optical pickup feeding device according to the embodiment of the present invention.

FIG. 9 is a front view of a main part of the optical pickup feeding device according to the embodiment of the present invention.

FIG. 10 is a front view of a main part of an optical pickup feeding device according to an embodiment of the present invention.

FIG. 11 is a front view of a conventional optical pickup feeding device.

FIG. 12 is a side view of a main part of a conventional optical pickup feeding device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical pickup 2 Lead screw 3 Feed nut 4 Chassis 5 Leaf spring 8 Contact part

Claims (5)

[Claims] 1. An optical pickup for recording or reproducing information recorded on a disc, a lead screw driven by rotation of a traverse motor, and an optical pickup mounted on the optical pickup and screwed to the lead screw. A feed nut for transporting the pickup in the radial direction of the disk, and a chassis that carries the traverse motor and the lead screw, wherein the feed nut has a contact portion formed to face the chassis at a predetermined distance. When the impact occurs, the screw engagement between the feed nut and the lead screw is separated, and when the optical pickup is moved in the radial direction of the disk, the chassis contact surface of the contact portion and the chassis contact surface of the chassis are moved. An optical pickup feeding device characterized by sliding. 2. The optical pickup according to claim 1, wherein a viscoelastic body having a high friction coefficient is provided on at least one of the chassis contact surface and the chassis contact surface of the contact portion. Feeder. 3. The optical pickup feeder according to claim 1, wherein a coating material for preventing slip is applied to at least one of the contact surface on the chassis and the contact surface of the chassis of the contact portion. . 4. An irregularity is formed on at least one of the upper surface of the chassis and the surface of the chassis in contact with the chassis so as to generate a high frictional force when the two surfaces slide. The optical pickup feeding device according to claim 1, wherein: 5. An optical pickup for recording or reproducing information recorded on a disk, a lead screw driven by rotation of a traverse motor, and an optical pickup mounted on the optical pickup and screwed to the lead screw to produce light. A feed nut for transporting the pickup in the radial direction of the disk, and a chassis that carries the traverse motor and the lead screw, wherein the feed nut has a contact portion formed to face the chassis at a predetermined distance. When the impact occurs, the screw engagement between the feed nut and the lead screw is separated, and when the optical pickup is moved in the radial direction of the disk, the chassis contact surface of the contact portion and the chassis contact surface of the chassis are moved. The lead screw is configured so that both ends of the lead screw are slid within the range in which the contact part slides. A groove-shaped or projection-shaped cam inclined in the direction approaching the disk was formed on the chassis, and when an impact occurred, the screwing of the feed nut and the lead screw was separated, and the optical pickup moved in the radial direction of the disk. An optical pickup feeding device, wherein the screwing of the feed nut and the lead screw is restored by sliding the contact portion according to the shape of the cam.