JP2001307436A - Pickup tilt adjusting mechanism for disk player - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pickup tilt adjusting (skew adjusting) mechanism for a disk player which can finely adjust a tilt error of a pickup to a disk. SOLUTION: Guide shafts 20 and 21 of the pickup are guided by guide blocks 37 and 38 at right angles to a deck while one of both ends is supported by a bearing block 36 in a free movement state. A spiral oblique cam 40 is engaged with end parts of the guide shafts 20 and 21 inside the guide blocks 37 and 38 and the guide shafts 20 and 21 are pressed against the spiral oblique surface 42 by leg parts 44a, 46a, and 46b of torsional coil springs 44 and 46. As the spiral oblique cam 40 is rotated, the guide shafts 20 and 21 have their end parts move up and down at right angles to the deck 14 to have their tilts adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for adjusting a movement path of a pickup so as to be kept at an optimum distance in parallel with a rotating surface of a disc player, and more specifically, to a mechanism of a shaft for guiding the pickup. Related to tilt adjustment (skew adjustment).

[0002]

2. Description of the Related Art Compact discs (CD), laser discs (LD), digital video discs (DVD),
In a player that reads information from an optical recording medium such as a mini-disc (MD), the pickup uses an emitting laser beam perpendicular to the recording track surface while scanning the recording surface of the disc from lead-in to lead-out. It must be moved while maintaining the angle of incidence.

The operation of a general disk player will be described. The rotation of a drive motor is transmitted by belt drive to rotate a screw shaft, and a pickup screwed on the screw shaft slides on a pair of guide shafts to slide the disk. Is linearly guided in the radial direction of the disk, and scans the recording track surface of the rotating disk to read the recorded information.

At this time, the laser beam emitted from the pickup must be perpendicularly incident on the recording track surface. However, usually, a pickup error such as a focusing error and a tilt error physically occurs between the pickup and the disc due to a mechanical relative positional relationship.

Therefore, such a pickup error is automatically corrected by a technique such as focus servo or tracking servo. However, if the guide shaft that supports and guides the pickup has a low assembling accuracy and the guide shaft is firmly fixed to the deck beyond the correction range in an assembling process having a large assembly tolerance, the correction cannot keep up with these servo mechanisms.

[0006]

As means for causing a laser beam to be perpendicularly incident on a recording track surface, Japanese Patent Publication No. 10-2793175 and Japanese Patent Publication No. 10-2793176 disclose pickup tilt adjusting devices. . In the illustration of the conventional disc player referred to in the application of these inventions,
A pair of guide shafts that support the turntable and the pickup are provided on the deck, and a gear portion that meshes with a screw shaft driven by a drive motor is formed on a side surface of the pickup.

However, in Japanese Patent Publication No. 10-2793175, the tilt adjusting means is a pickup guide rail having a cylindrical cam formed by recessing an annular groove obliquely inclined with respect to the main shaft on the outer periphery of the cylinder and having one end pivotally supported. The free end of the guide rail is inserted into and supported by the annular groove of the cylindrical cam provided on the deck, and the inclination of the guide rail is adjusted by rotating the cylindrical cam to vertically move the end of the guide rail vertically with respect to the deck. are doing.

However, in this case, it is necessary to provide a space for providing the cylindrical cam mechanisms on both sides of the guide rail on the outside of the both ends, and this is an obstacle to making the longitudinal direction of the deck on which the guide rail extends compact.

Further, since the cylindrical cam mechanism completes the moving range from the valley to the peak in half a rotation, the inclination of the cam becomes steep so that the required adjustment range is set to be half of the outer diameter of the cylindrical cam. Since the cam mechanism adjusts only one end of the guide rail, the entire moving range for the adjustment is covered by a half circumference of one cylindrical cam.

If the cam gradient is increased to satisfy these conditions, the tendency of the cylindrical cam to be reversibly rotated by the external force applied to the guide rail by disturbance such as vibration cannot be denied. Therefore, the reliability that the adjustment position is maintained as it is is poor.

In addition, the guide rail ends are supported by both wall surfaces of the cylindrical cam groove. To rotate the cylindrical cam, a play is required between the guide rail end and the cam groove wall surface. On the other hand, since the disc player is not always used in the same posture, it is inevitable that the adjustment position fluctuates in the range of the play gap depending on the used posture.

Further, in Japanese Patent Publication No. 10-2793176, one end is movably fixed at one end, and the other end of the guide shaft of the pickup urged by an elastic member from one side is supported by the end face of the screw at the other end. The tilt adjustment is performed by changing the relative height of the support with the floating end by the rotation of.

However, the length of the screw hole is limited by the thickness of the deck, and it cannot be considered that a sufficient length for exerting a rotation inhibiting force by friction on the screw to be screwed is obtained. Therefore, loosening may occur due to disturbance such as vibration, and maintaining the adjustment position is not reliable.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pickup tilt adjustment (skew adjustment) mechanism for a disk player which can precisely adjust the tilt error of the pickup with respect to the disk by overcoming the above problems.

[0015]

In order to attain the above object, a pickup tilt adjusting mechanism for a disc player according to the present invention comprises at least a pair of guide shafts for slidably supporting a pickup, and the guide shafts being connected to each other. A support member that supports near both ends, a guide shaft adjustment member having a helical inclined cam whose rotation axis is orthogonal to the guide shaft inside the support member and whose end surface is in sliding contact with the outside of the cylinder of the guide shaft; And a plate-like deck for supporting the guide shaft adjustment member and the support member, wherein the relationship between the diameter D of the guide shaft adjustment member and the distance A of the support span is πD <A.

The guide shaft adjusting member was outsert to the plate deck. The guide shaft adjusting member is provided with a hit, so that the guide shaft adjusting member does not rotate more than one rotation. Further, a design horizontal position mark is provided on the guide shaft adjusting member and the plate-like deck.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a pickup tilt adjusting mechanism for a disc player according to the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing an embodiment of a disc player 12 having a pickup tilt adjusting mechanism 10 according to the present invention, and FIG. 2 is a rear view of FIG. FIG. 3 is a side view taken along line 3-3 in FIG. The same reference numerals are used for the same members.

Reference numeral 14 denotes a deck of the disk player 12, which is press-formed from a metal plate. A center hole of a disk (not shown) is closely fitted to a mounting shaft 16a of a disk motor 15 disposed on the left side in the figure. The turntable 16 to be rotated is mounted. On the radius line on the right side of the turntable 16 in the figure, a pickup 18 having an optical system unit 17 including a light source is provided. The pickup 18 is slidably supported by a pair of guide shafts 20 and 21 on the back side of the deck 14 (see FIG. 2). The guide shafts 20 and 21 function as guides for linearly moving the pickup 18 along a radius line of the turntable 16 or a disc (not shown).

The pickup 18 has a guide shaft 2
A toothed rack 22 is disposed in parallel with 0 and 21, and meshes closely with the pinion 24 to interlock. A large gear 26 is fixed coaxially with the pinion 24 and rotates integrally with the pinion 24.
The large gear 26 is driven by being connected to a drive gear 34 directly connected to a drive shaft of a feed motor 32 via intermediate reduction gears 28 and 30.

The feed motor 32 is provided with such a gear train 3.
Pinion 24 and rack 2 via 4, 30, 28, 26
2 drives the pickup 18 linearly. Pinion 2
Since the drive mechanism using the rack 4 and the rack 22 has a degree of freedom in the direction along the tooth surface perpendicular to the moving direction, the engagement between the pinion 24 and the rack 22 is determined with respect to the axis of the guide shafts 20 and 21 involved in the adjustment operation. It does not interfere with vertical displacement.

On the back side of the deck 14 shown in FIG. 2, one bearing block 36 and three guide blocks 37 and 38 are used as support members for the guide shafts 20 and 21. It is formed by outsert molding which is sandwiched between the plate-like decks 14 integrally with the fixed seat 54 to be formed. One end 20a of the first guide shaft 20 that guides the pickup 18 linearly is formed in a spherical shape, and the movement in the axial direction is limited by coupling with a bearing block 36 formed at a fixed position of the deck 14 by a spherical joint. Is freely movable.

The other end of the first guide shaft 20 is
First guide block 37 formed at a fixed position on deck 14
Supported by an axially outward displacement and deck 1
Displacement parallel to the four surfaces is prevented, and movement in the direction perpendicular to the surface of the deck 14 is possible. Along the vertical guide projection 37a of the first guide block 37 that supports both side surfaces of the guide shaft 20 with the minimum area, the slide shaft can be smoothly slid and displaced only in the vertical direction with low friction. Also, the first guide block 37
Since the guide shaft 20 is prevented from moving in the axial direction by the bearing block 36, the guide shaft 20 is opened in the axial direction by limiting only the displacement in the radial direction.

Both ends of a second guide shaft 21 which is another linear guide member of the pickup 18 are connected to the deck 14.
And is guided so as to be displaceable only in a direction perpendicular to the deck 14 surface. That is, as clearly shown in FIG. 4, the second guide block 38 is also the first guide block 3
Similarly to 7, the second guide shaft 21 is slidably supported in the vertical direction from both sides by the vertical guide protrusion 38a that contacts with the minimum area. Further, the outside of the second guide block 21 receiving portion of the second guide block 38 is closed by a wall 38b to limit the displacement of the second guide shaft 21 in the axial direction.

Further, as a characteristic configuration of the present invention, a guide shaft adjustment is provided on the surface of the deck 14 which is located inside the guide blocks 37 and 38 which support three shaft end portions of the guide shafts 20 and 21 and regulate the movement direction. A helical inclined cam 40 as a member is integrally and rotatably formed by outsert molding sandwiched between the plate-like decks 14 together with a flange 48 to be described later on the disk-side surface of the deck 14. The helical slope cam 40 is connected to the guide shafts 20, 21.
Helical inclined cam 4 that engages on the inner side from the shaft end so as to embrace it from the side and that supports guide shafts 20 and 21
By setting the relationship of the outer peripheral circle diameter D to the span A of 0 to be A> πD, the guide shafts 20 and 21 can be supported on the spiral slope 42 in a stable positional relationship, and accurate adjustment can be achieved. it can.

The ends of the guide shafts 20 and 21 engaged with the helical inclined cam 40 are respectively connected to one leg 44a of the torsion coil spring 44 and the torsion coil spring 46.
Are urged by the two legs 46a, 46b to be elastically pressed against the spiral slope 42 (see FIG. 3). Torsion coil spring 44
The other leg 44b is locked by a projection 14c provided on a part of the deck 14 and is prevented from rotating.

The torsion coil springs 44, 46 are respectively provided with coil portions 44c, 46 on projections 14a, 14b projecting from the deck 14.
c is supported and the guide shafts 20, 21 are always elastically pressed against the spiral slope 42, so that the guide shaft 2 can be placed in any position of the disc player 12.
There is no play (backlash) between 0, 21 and the spiral slope 42, and the sliding contact state is maintained. Therefore,
By rotating the spiral slope cam 40, the guide shafts 20 and 21 are smoothly displaced vertically to the deck 14 while the spiral slope 42 is in close contact with the engagement portion. Accordingly, the inclination of the pickup 18 with respect to the disk is corrected in conjunction with the displacement of the guide shafts 20, 21.

FIG. 4 is a side view showing the relationship between the spiral cam 40 and the second guide block 38 with respect to the guide shafts 20 and 21. The spiral slope cam 40 is formed from both sides of the deck 14 by outsert molding so as to be sandwiched between the deck 14 and the flange 48 on the opposite side.
4 are connected by a shaft portion 50 (see FIG. 3) penetrating through the shaft 4.
Accordingly, the spiral slope cam 40 and the flange 48 are connected to the shaft 5
It is possible to turn integrally around zero. Spiral slope cam 40
For example, a concave portion 41a having a hexagonal inner wall at the center is engraved on a boss portion 41 protruding to the center of the boss portion 41 so as to fit a wrench (not shown) for a hexagon socket head cap screw. The turning operation of the spiral slope cam 40 to be adjusted is performed by a wrench adapted to the concave portion 41a.

The helical slope cam 40 moves the guide shafts 20 and 21 along the helical slope 42 to the uppermost end 42L farthest from the lowermost end 42L located near the deck 14.
One rotation is required to displace to U. Furthermore, when adjusting the inclination at both ends as in the case of the guide shaft 21,
Since each of the helical slope cams 40 shares half of the required movement range, the gradient with respect to the movement stroke of the guide shaft 21 can be formed more gently.

In such a mechanism having a gentle gradient, there is no reversibility in which the helical slope cam 40 is turned by the urging by the external force acting on the guide shafts 20, 21. Accordingly, the guide shafts 20, 21 are elastically pressed against the spiral slope 42 by the urging forces of the torsion coil springs 44, 46, and are displaced vertically with respect to the deck 14 by the rotation of the spiral slope cam 40. In cooperation with the urging forces of 44 and 46, the rotation of the helical slope cam 40 is prevented by the friction force, and the set relative position is stably maintained. It does not collapse by action.

The spiral slope 42 of the spiral slope cam 40 is
The helical slope starting from the lowermost end 42L and continuing along the cylindrical surface makes one round and reaches the uppermost end 42U, has the same phase as the lowermost end 42L, generates a step 42S, and becomes discontinuous. In order to prevent the discontinuous step 42S from being included in the adjustment range, the flange 48 that rotates integrally with the spiral slope cam 40 is used.
The protrusion 52 provided on the rear surface is integrally formed with the guide block 38, and the rotation is restricted by a regulating wall 56 extending from a fixed seat 54 formed by outsert molding that is sandwiched between the decks 14 on the back surface side. The rotation of the spiral slope cam 40 is prevented from reaching one rotation. Reference numeral 57 denotes a through hole through which synthetic resin formed on the front and back of the deck 14 is communicated and integrally formed (see FIG. 2).

Further, as shown in FIG. 1, an index 58 is provided on the flange 48 which rotates integrally with the spiral slope cam 40.
Are projected, and in cooperation with the benchmark 60 engraved on the surface of the deck 14, a mark is provided almost at the center of the adjustment range of the spiral slope cam 40 as a position assumed to be horizontal in design of the guide shafts 20 and 21. After confirming this visually, adjustment can be achieved by fine movement either up or down. Reference numeral 62 denotes a through hole penetrating through the flange 48 and the deck 14. When an adjustment operation is performed by an automatic adjustment device (not shown), the neutral position is determined by transmitting light rays, and the spiral inclined cam 40 is rotated based on the neutral position. adjust.

According to this configuration, unlike the cylindrical cam, the vertical movement of the adjustment displacement does not reverse in the same rotational direction. Moreover, since there is no backlash between the guide shafts 20 and 21 and the spiral cam 40, there is no play (dead band) in the adjustment operation, and quick and reliable adjustment can be realized.

As described above, the spiral slope cam 40 as the guide shaft adjusting member has the spiral slope 42 open. Therefore, the bearing block 36 and the guide block 3 as support members for the guide shafts 20 and 21 are provided.
Like the fixed seat 54 on the side opposite to the surfaces 7 and 38, it can be integrally formed by outsert molding sandwiched between the plate-like deck 14 and the flange 48. However, it is needless to say that the present invention is not limited to the above embodiment, and can be implemented by various modifications and combinations.

[0034]

As is apparent from the above description, according to the pickup tilt adjusting mechanism of the disk player according to the present invention, the longitudinal direction of the deck is reduced by arranging the spiral cam on the side surface of the guide shaft. It can be shortened and the whole disc player can be made compact.

Further, since the relationship between the diameter D of the engaging portion of the spiral cam and the guide shaft and the support span A is set to πD <A, the trouble with the spiral cam on the inclination of the guide shaft is reduced. In addition, the linearity of the displacement of the guide shaft with respect to the rotation angle of the spiral slope cam can be obtained with high accuracy.

Since the rotation of the spiral cam is restricted, useless operation for adjusting the height is eliminated. Also, since the members on both sides of the deck are integrally molded by outsert molding, the number of parts is reduced, and assembling accuracy is improved.

An index and a benchmark are provided on a flange which rotates together with the spiral slope cam so that the initial state (standard reference position) can be visually checked. In addition, the deck can be reused. Furthermore, since the positional accuracy is determined by the guide shaft, assembly can be performed by a stacking method.

[Brief description of the drawings]

FIG. 1 is a plan view of a disc player to which an embodiment of a pickup tilt adjusting mechanism of a disc player according to the present invention is applied, as viewed from a disc side.

FIG. 2 is a rear view of FIG.

FIG. 3 is a side view taken along the line 3-3 in FIG. 2;

FIG. 4 is a perspective view illustrating a relationship between an end portion of a guide shaft, a spiral slope cam, and a guide block in the pickup tilt adjusting mechanism of the disc player according to the present invention.

[Explanation of symbols]

 Reference Signs List 12 disc player 14 deck 15 disc motor 18 pickup 20, 21 guide shaft 22 rack 24 pinion 32 feed motor 36 bearing block 37, 38 guide block 40 spiral inclined cam 44, 46 torsion coil spring 48 flange 52 projection 56 regulating wall 58 index 60 benchmark

Claims (4)

[Claims] At least one pair of guide shafts that slidably support a pickup, a support member that supports the guide shafts near both ends, a rotation axis inside the support member that is orthogonal to the guide shaft, and A guide shaft adjusting member having a helical inclined cam whose end surface is in sliding contact with the outside of the cylinder of the guide shaft; and a plate-like deck supporting the guide shaft adjusting member and the support member. Wherein the relationship between the diameter D of the disc and the distance A of the support span is πD <A. 2. The pickup tilt adjusting mechanism for a disc player according to claim 1, wherein the guide shaft adjusting member is outsert to the plate-like deck. 3. The pickup tilt adjusting mechanism for a disk player according to claim 1, wherein the guide shaft adjusting member is provided with a hit, and the guide shaft adjusting member is prevented from rotating more than one rotation. . 4. The pickup tilt adjusting mechanism for a disc player according to claim 1, wherein a designed horizontal position mark is provided on the guide shaft adjusting member and the plate-like deck.