JP2002100131A - Disk recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively provide a disk recording and reproducing device which can mechanically adjust a tilt angle with a simple configuration. SOLUTION: The disk recording and reproducing device is provided with a pickup 13 which receives information recorded on a disk 100 placed on a turntable 12a, shafts 14, 15 which guide the pickup 13 in a parallel direction relative to the recording surface of the disk 100, a guide groove which guides the shafts 14, 15 in a direction orthogonal to the moving direction of the pickup 13, energizing means 16 to 19 which energize the shafts 14, 15 in the direction orthogonal to the moving direction of the pickup 13, and a regulation member 20... which is provided at the side which receives energizing force from the energizing means 16 to 19 through the shafts 14, 15, and displaces the shafts 14, 15 in the direction orthogonal to the moving direction of the pickup 13. The tilt angle of the pickup 13 relative to the disk 100 can be adjusted by operating the regulation member 20....

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc recording / reproducing apparatus which is an optical information recording / reproducing apparatus for an optical disc player or the like.

[0002]

2. Description of the Related Art Conventionally, an optical information recording / reproducing device such as an optical disk player is provided with an optical pickup device. This pickup device focuses a light beam generated by a light beam generating means such as a semiconductor laser on a recording surface of an optical disc as a condensed spot of a predetermined diameter by an objective lens, thereby recording, erasing, and deleting signals on the optical disc. And a signal from the optical disk.

[0003] Recent products tend to be miniaturized and thinned, so that the pickup is also thinned. As the thickness becomes thinner, the focal length of a light beam such as the laser is naturally shortened. Accordingly, since the movable range of the lens is narrowed, the relative position of the pickup itself with respect to the disk surface (adjustment of the distance and inclination with respect to the disk surface) is adjusted.

Regarding the necessity of such adjustment work,
For example, National Te, issued in June 1997
physical Report Vol. 43. That is, since the tilt angle error of the optical head alone is generally limited to about 0.2 degree, even after the optical head is mounted on the drive mechanism, the tilt angle (the optical head optical axis and the disk surface during DVD reproduction cannot be changed). High-precision adjustment of the inclination angle) is required again.

On the other hand, a technique for electrically or optically correcting coma aberration (which occurs when there is a tilt angle error between the optical axis of the optical head and the disk surface) has been proposed, but the device is complicated. And has not yet reached the level of practical use. Therefore, developing an adjustment mechanism having a simple structure capable of mechanically adjusting the tilt angle is considered to be the most effective method for improving jitter.

[0006] To improve the jitter means to adjust the tilt angle of the disk to an optimum value. In one method, for example, the optical pickup is moved in the radial direction (E, F directions) of the disk. The tilt angle is adjusted by tilting the guide shaft (in the directions C and D) for this purpose (the optical pickup itself moves closer to or away from the disk surface).

As another method, there is a method of tilting a turntable on which a disk is placed. In this case, since the turntable is actually attached to the motor for rotating the disk, the motor is tilted. Since the method of tilting the guide shaft described first is nowadays mainstream, an adjustment mechanism of the guide shaft will be described below with reference to FIG.

Reference numeral 1 denotes a chassis having a substantially rectangular shape, and a spindle motor 2 disposed near a center end. A turntable 2a is attached to the spindle motor 2. The turntable 2a has a substantially disk shape, and a central portion thereof is conical and can be inserted into the center hole of the disc 100. The disc 100 is mounted on the turntable 2a by some means, and the spindle motor 2 rotates. As a result, the disk 100 is rotated. Although not shown,
Naturally, a pressing member such as a magnet is disposed above the disc 100.

On both sides of the spindle motor 2, a main shaft 4 and a sub-shaft 5 are arranged so that an optical pickup 3 described later can be moved in the radial direction of the disk. In particular, the main shaft 4 restricts the movement of the optical pickup 3 (the optical pickup 3
The main guide of the)), its parts accuracy,
In addition, positional accuracy with respect to the turntable 12a (disk) is extremely important.

Position holding restricting portions 1a, 1b, 1 for restricting the position of the main shaft 4 and the sub shaft 5 are provided.
c and 1d are formed near the four corners (both ends of the main shaft 4 and the sub shaft 5) at the corners of the chassis 1. The position holding restricting portions 1a, 1
Since b, 1c, and 1d have substantially the same shape and the same function, the position holding restricting portion 1a will be described here as an example.

The position holding restricting portion 1a has a substantially U-shaped rectangular parallelepiped block shape, a concave portion is formed near the center thereof, and both ends of the main shaft 4 are fitted into the concave portion, and the position is restricted. You. In the case of 1c and 1d, the sub shaft 5 is fitted into the recess. Although not shown, a falling-off preventing member (which is a member for mechanically stopping other than an urging member described later) that prevents the main shaft 4 (same for the sub-shaft 5) from coming off is arranged. .

As described above, the positions of the main shaft 4 and the sub shaft 5 in the height direction (C and D directions) are adjusted by adjusting screws 10 described later. This allows
The height of the main shaft 4 and the sub shaft 5, that is, the height of the pickup 3, can be changed.

The main shaft 4 and the sub shaft 5 are urged in the direction of the chassis 1 (direction D) by urging members 6, 7, 8, and 9. This allows
The height direction (directions of arrows C and D) includes an adjustment screw (adjustment member) 10 from below (direction of arrow C) and urging members 6 and 7 from above.
The height positions of the main shaft 4 and the sub shaft 5 are regulated by 8 and 9.

The biasing members 6 are, for example, dragonfly springs, and the adjustment screws 10 are of a type having a smaller pitch than the general screws (the amount of advance per screw rotation is small), so that fine adjustment is easy. ing. Next, in the directions of arrows G and H of the main shaft 4 (directions along the chassis 1), the position of the main shaft 4 (the directions of arrows G and H) is determined by the size of the inner surface of the concave portion of the position holding restricting portions 1a and 1b. ) Is regulated. Consequently, the arrows G and H of the optical pickup 3
The position in the direction is regulated.

With the above configuration, the tilt angle (tilt angle) between the optical axis of the optical pickup 3 and the disk surface at the inner peripheral portion, the central portion, and the outer peripheral portion of the disk 100 is determined by the main shaft 4 and the sub-shaft. By adjusting with the number 5 (actually adjusting to the tilt angle of the optical pickup 3), it is possible to secure the optimum state for the disk 100.

[0016]

However, the above-mentioned conventional structure has the following problems. That is, the main shaft 4 and the sub shaft 5 are regulated in the height direction by adjusting screws 10 from below and urging members 6, 7, 8, 9 from above.
The height position is regulated to a fixed state. However, the regulation in the directions of arrows G and H is performed by the position holding regulating section 1 in the conventional example.
It is controlled only by the in-recess dimensions a to 1d.

However, if the recess is not larger than the outer dimensions of the main shaft 4 and the sub shaft 5,
Shafts 4 and 5 cannot be fitted and adjustment screw 1 from below
Adjusting the height by 0 (moving the shafts 4 and 5 up and down along the inner surfaces of the concave portions of the position holding restricting portions 1a to 1d) requires a slightly larger inner dimension than the shaft.

However, if the size of the concave portion is too large than the shaft diameter, play in the directions of arrows G and H occurs between the shafts 4 and 5 and the position holding restricting portions 1a to 1d. In the same manner, rattling occurs in No. 3.

Recently, the recording density of a DVD mounted on a portable disk player, a notebook personal computer or the like has been increased as compared with a conventional CD, and therefore, naturally, the minimum bit size is 0.834 μm of a CD / 1.6 μm of track pitch.
On the other hand, in the DVD, the minimum bit size is 0.4 μm / the track pitch is 0.74 μm. That is, mechanically high accuracy is required, including the servo of the feed system of the pickup.

As described above, the market scale has been steadily expanding from a handy type recording / reproducing apparatus to a DVD of a navigation system mounted on a vehicle. In the case of a vehicle, it is obvious that vibration is applied for the purpose of use. When vibration is applied, the main shaft 4 (and the sub shaft 5) and the position holding restricting portions 1a and 1b (and 1c, 1c, The optical pickup 3 is swung by an amount corresponding to the backlash between the concave portion 1d).

When the optical axis of the optical pickup 3 is deflected, the possibility that a signal is not recognized in recording / reproducing greatly increases. If the degree of the shake becomes large, it becomes impossible to read the signal recorded on the disk, resulting in a defective product.

In order to suppress the occurrence of such backlash, the main shaft 4 and the sub shaft 5
In order to reduce the clearance between the groove and the concave portions of the position holding restricting portions 1a to 1d, high precision of the parts is required, and quality control in the manufacturing process becomes difficult. There is a disadvantage that the product cost increases.

An object of the present invention is to provide a disk recording / reproducing apparatus in which the tilt angle can be mechanically adjusted with a simple configuration at a low cost.

[0024]

According to the present invention, means for solving the above-mentioned problems are constituted as follows.

(1) A pickup for receiving information recorded on a disk placed on a turntable, a shaft for guiding the pickup in a direction parallel to a recording surface of the disk, and a shaft for guiding the pickup. A guide groove that guides the shaft in a direction perpendicular to the movement direction of the pickup; a biasing unit that biases the shaft in a direction perpendicular to the movement direction of the pickup; and a biasing unit that biases the shaft through the shaft. An adjustment member provided on the side receiving the force and for moving the shaft in a direction perpendicular to the movement direction of the pickup, and by operating the adjustment member, the tilt of the pickup with respect to the disc is adjusted. The angle can be adjusted.

According to this configuration, since the shaft is always urged by the urging means in a direction orthogonal to the moving direction of the pickup, the shaft can be easily adjusted by the adjusting member, and the tilt can be easily adjusted. Adjustment of the angle becomes easy, and the tilt angle can be stably maintained. Further, the configuration is simple, and the apparatus can be provided at low cost.

(2) The vertical axis drawn to the contact point between the tip of the adjusting member and the shaft formed in a round bar shape is offset from the axis of the shaft by a predetermined distance. The relative position of the adjustment member is set.

According to this structure, the tip of the adjusting member abuts on the shaft on which the urging force of the urging means is acting, offset by a predetermined distance from the axis of the shaft. The shaft comes into contact with only one side of the guide groove, and the support state is stabilized. Therefore, the fitting tolerance between the shaft and the guide groove does not require so high precision, and does not require a large biasing force on the biasing means, and can suppress the occurrence of rattling of the shaft,
Even if a shock or vibration occurs, the stability is not lost, and the error of the tilt angle can be stably reduced to a minimum.
In addition, it is possible to reduce the weight and size.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a disk recording / reproducing apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a perspective view showing a main structure inside the disk recording / reproducing apparatus. Numeral 11 denotes a chassis which has a substantially rectangular shape. A turntable 12a is attached to an output shaft protruding from the top of the turntable.

The turntable 12a has a substantially disk shape, and a center hole of the disc 100 can be fitted into a central portion of a conical shape. The disk 100 is rotated by the rotation of the spindle motor 12 by mounting the disk 100 on the turntable 12a by a suitable means (not shown).
The disc 100 is urged by the pressing member such as a magnet (not shown) disposed directly above the turntable 12a into a pressed state.

On both sides of the spindle motor 12, an optical pickup 13 to be described later is
A main shaft 14 and a sub shaft 15 for restricting movement in the radial direction are arranged. In particular, the main shaft 14 restricts the movement of the optical pickup 13 (used as a main guide of the optical pickup 13) (to improve the jitter value), and its component accuracy and relative correspondence with the turntable 12a (disk). Position accuracy is extremely important. For example, a polishing shaft having an outer diameter of 3 mmφ with good surface accuracy and dimensional accuracy is required.

Although a drive source for moving the optical pickup 13 is not shown, the optical pickup 13 is moved (in the directions of arrows E and F) via a gear by a motor or the like.

In order to regulate the position of the main shaft 14, a part of the chassis 11 is cut and raised, and
a, 11b, 11c and 11d are formed. The bent portions 11a and 11c are arranged near the spindle motor 12. The bent portions 11a, 11b, 11
The c and 11d have a substantially rectangular hole shape at the center, and the main shaft 14 and the sub shaft 15 are inserted into the square holes (guide grooves) in a penetrating state. The upper side of the square hole is closed, so that the main shaft 14 and the sub-shaft 15 do not serve as a mechanical stopper so that the main shaft 14 and the sub-shaft 15 do not come off (fall). As described above, the connection of the upper portions facilitates component processing, that is, facilitates securing the accuracy of the inside dimensions.

The main shaft 14 has the bent portions 11a, 1
The rectangular hole 1b is held in contact with the side wall surfaces 11e and 11f. The sub-shaft 15 has a side wall surface 11g and a side wall surface 11h of the square holes of the bent portions 11c and 11d.
Is held in contact with This both shafts 1
4, 15 with the side wall surfaces 11e, 11f, 11g, 11
The means for holding the abutment on the h-plane will be described later.

In particular, in order to regulate the position of the movement of the optical pickup 13 (adjustment is made in the X, Y and Z directions to secure the position accuracy), the processing accuracy of the main shaft 14 itself is required. The positional accuracy relative to the turntable (disc 100) is extremely important.

The importance of the positional accuracy of the optical pickup 13 will be described. Since the recording density of a DVD is higher than that of a conventional CD, the minimum bit size is, of course, 0.834 μm of the CD / track pitch of 1. .6 μm. In the case of DVD, the minimum bit size is 0.4 μm / track pitch 0.74 μm.
Feed precision and machine precision are important.

Bending portions 11a, 11b, 1 of chassis 11
Cutouts 21 are formed near 1c and 11d so that the bases of the urging members 16, 17, 18, and 19 for urging and holding the shafts 14, 15 can be fixed. Projection portions 22 for fitting the ring-shaped base portions 17, 18, and 19 are formed.

On the other hand, the chassis 1 immediately below both ends of the main shaft 14 has a receiving portion 1 having a convex shape of a half punch.
1i and 11j are formed. In addition, sub shaft 1
5, similar receiving portions 11k and 11m are formed immediately below both ends of 5, respectively. Each receiving part 11i, 11j, 11k, 1
1m have substantially the same shape and the same function, and therefore, the receiving portion 11i will be described as an example.

The receiving portion 11i is, as shown in FIG.
A half punch having a round diameter (outer diameter) of about 4 mm to 5 mm has a convex shape, the height of the convex part is about 0.5 mm, and an adjusting screw 20 as an adjusting member is provided at the center thereof. A tap (screw hole) for screwing is formed. The adjustment screw 20 is of a type having a smaller pitch than the general screw (the amount of advance per screw rotation is smaller), and allows fine adjustment.

Here, in this embodiment, in particular, the tip of the adjusting screw 20 and the main shaft 1 formed in a round bar shape are used.
The perpendicular 20a drawn at the contact point with the main shaft 1
The relative position of the adjustment screw 20 with respect to the main shaft 14 is set so as to be offset by a predetermined distance d from the axis line (center line) 14a of No. 4.

As described above, the main shaft 14 is supported in an eccentric position by the adjusting screw 20 so that the main shaft 14 is bent at the bent portions 11a and 11b.
Can be always brought into contact with the side wall surfaces 11e and 11f on one side of the first side. That is, if the contact point of the adjusting screw 20 is eccentric to the outside (H side) from the axis 14 a of the main shaft 14, the main shaft 14 is moved inward (G side) by the urging force of the urging members 16 and 17. ), And in this state, the height of the main shaft 14 is stably maintained by the urging force of the urging members 16 and 17 from above and the push-up support by the adjusting screw 20 from below. Will be held. Therefore, it is not necessary to control the processing accuracy of the inner dimensions of the square holes of the bent portions 11a and 11b so strictly, and the manufacture becomes easy.

Further, by cutting and raising a part of the chassis 11 to form the bent portions 11a and 11b, the number of parts can be reduced as compared with the conventional case, and the apparatus can be provided at low cost. . Further, the dragonfly springs as the urging members 16 and 17 need only be able to apply an urging force to the main shaft 14 only in the downward direction (only in one direction), and the shape may be simple.
Space saving can also be achieved. Since the support structure of the sub shaft 15 is the same as that of the main shaft 14, the description is omitted.

Here, the main shaft 14 (and the sub-shaft 15) are connected to one side wall surface 1 by a method other than the above.
As a method (comparative example) for urging the main shaft 1e and 11f, for example, as shown in FIG. 4A, when urging force is applied obliquely downward to the main shaft 14, that is, the axial center line 14a. Biasing force 1 toward the outside (G direction)
When 6b acts on the main shaft 14, the downward biasing force (vertical downward component force) 16c is reduced by half. Therefore, a double biasing force is required.

Further, by adjusting the height of the main shaft 14 with the adjusting screw 20, the position of the contact point 16a between the urging member 16 (17) and the main shaft 14 changes. Accordingly, the direction of the urging force changes, and as shown in FIG. 4B, if the height of the main shaft 14 is increased,
Greater bias is needed. In order to obtain a large urging force, not only the urging member 16 (17) but also the structural strength of the chassis 11 needs to be improved, which makes it difficult to reduce the weight and size.

As is apparent from comparison with this comparative example, in the present embodiment, as shown in FIG.
(15) is supported in an eccentric position by adjusting screws 20.
(18, 19) without the need for a large biasing force,
Bent portion 11 formed by cutting and raising chassis 11
a, 11b (11c, 11d) Side wall surface 1 on one side of square hole
1e, 11f (11g, 11h) can always be brought into contact to obtain a stable support state. Therefore, the shaft 1
The rattling of the shafts 14 and 15 can be suppressed without requiring a very high precision in the fitting tolerance between the guide grooves 4 and 15 and the error of the tilt angle can be minimized. . Further, even if an impact or vibration is generated, the stability of the support state of the shafts 14 and 15 is not lost, and a predetermined tilt angle is stably maintained, which is suitable for use in vehicles and the like.

[0047]

The present invention has the following effects.

According to the first aspect, since the shaft is always urged by the urging means in the direction orthogonal to the moving direction of the pickup, the shaft can be easily adjusted by the adjusting member. Adjustment of the tilt angle becomes easy, and the tilt angle can be stably maintained. Further, the configuration is simple, and the apparatus can be provided at low cost.

According to the second aspect, the tip of the adjusting member abuts on the shaft on which the urging force of the urging means is acting, offset by a predetermined distance from the axis of the shaft. In addition, the shaft abuts only on one side of the guide groove, and the support state is stabilized. Therefore, the fitting tolerance between the shaft and the guide groove does not require so high precision, and does not require a large biasing force on the biasing means, and can suppress the occurrence of rattling of the shaft,
Even if a shock or vibration occurs, the stability is not lost, and the error in the tilt angle can be stably reduced to a minimum. In addition, it is possible to reduce the weight and size.

[Brief description of the drawings]

FIG. 1 is a perspective view of an optical pickup device in a conventional disk recording / reproducing apparatus.

FIG. 2 is a perspective view of a disk recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 3 is a sectional view of the main part.

FIG. 4 is a sectional view of a comparative example of the main part.

[Explanation of symbols]

 12a-turntable 13-pickup 14, 15-shaft 14a, 15a-axial line 16-19-biasing means 20-adjusting member 100: disk

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Matsukawa 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (72) Inventor Tatsuya Terashima 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka (72) Inventor Shoji Taniguchi 22-22 Nagaikecho, Abeno-ku, Osaka City, Osaka F-term (reference) 5D068 AA02 BB01 EE16 GG06 5D117 KK08 KK09 KK22

Claims (2)

[Claims] A pickup configured to receive information recorded on a disk placed on a turntable; a shaft guiding the pickup in a direction parallel to a recording surface of the disk; A guide groove for guiding the pickup in a direction perpendicular to the moving direction of the pickup; an urging means for urging the shaft in a guide direction of the guide groove; and a side receiving an urging force from the urging means via the shaft. And an adjusting member for moving the shaft in a direction orthogonal to the moving direction of the pickup,
A disc recording / reproducing apparatus, comprising: adjusting a tilt angle of the pickup with respect to the disc by operating the adjustment member. 2. An adjustment to the shaft such that a perpendicular drawn at a contact point between the tip of the adjustment member and the shaft formed into a round bar is offset by a predetermined distance from an axis of the shaft. 2. The disk recording / reproducing apparatus according to claim 1, wherein relative positions of the members are set.