JP2001101674A - Optical disk device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical disk device capable of realizing optimal skewing and the high-speed movement of an optical pickup part. SOLUTION: A rotary-driving part 102 and an optical pickup part 103 are attached to one main rail 104. For radial skewing, no change occurs in the inclinations of the pit surface of an optical disk and a laser optical axis even when a movement is made to any place on the main rail 104. For tangential skewing, a sub-rail 105 is placed parallel to the main rail 104, and a plane is formed by the two rails. Thus, by presetting the rail height of the outer peripheral side of the sub-rail 105 to an optional height by a rail bracket 106, the sub-rail 105 is set parallel to the main rail 104 only by adjusting the other rail height.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk-shaped optical recording medium which is irradiated with a laser beam to record an information signal in a recording area of the recording medium or to record an information signal recorded in the recording area of the recording medium. The present invention relates to an optical disk device for reproducing.

[0002]

2. Description of the Related Art A disc-shaped optical magnetic recording medium (hereinafter referred to as an optical disc) such as an optical disc or a magneto-optical disc having a concentric or spiral storage area formed on the surface of a disc formed of a transparent resin or the like. An optical disc device that records a signal or reproduces an information signal generally includes a rotation drive unit that holds an optical disc and rotates at a constant linear velocity or a constant angular velocity, emits a laser beam, and outputs the laser beam through an objective lens. An optical pickup unit having a detector for focusing the reflected light from the recording area while focusing on the recording area of the optical disk and further detecting the focused reflected light, and transporting the optical pickup unit from the inner circumference to the outer circumference of the optical disk And a transport unit for performing the operation.

[0003] The optical disk is formed by forming fine irregularities on the surface of a disk plate formed of a transparent resin or the like (for example, polycarbonate resin), and depositing aluminum thereon to form a reflective film. The oblong concave portion is called a pit.
The optical disk device irradiates a laser beam emitted from an optical pickup onto pits of the optical disk, and reads a signal of the optical disk from a change in laser reflected light due to unevenness.

[0004] In the optical pickup section, it is required to narrow the laser beam to a spot in accordance with the width of a minute pit. The diameter of the light spot is proportional to the wavelength of the laser, and inversely proportional to the numerical aperture of the objective lens that narrows the light.

[0005] Such a conventional optical disk device 200
Is, for example, as shown in FIG.
, A rotation drive unit 202, an optical pickup unit 203,
Main rail 204, sub-rail 205, rail bracket 206, lead screw 207, feed motor 208, gear train 209, rail guide 21
0 and a rail height adjustment unit 211.

[0006] A rotation drive unit 202 for rotatingly driving the optical disk 400 includes a turntable 202a on which the optical disk 400 is mounted and a turntable 2 for rotating the optical disk 400.
Drive unit 202c that rotates through the base chassis 20a.
1 and a mounting plate 202b to be mounted on the mounting plate 202.

The optical pickup section 203 passes the main rail 204 through a long span bearing 203b and the sub rail 205 through a short span bearing 203c.
Since the rails of the book are attached to the base chassis 201 by a method described later, the optical disc 400 can be moved in the radial direction.

Further, a lead screw 207 is provided on the base chassis 201 by a system computer (not shown).
Is transmitted to a lead screw 207 arranged in parallel with the main rail 204 via a gear train 209. The lead screw 207 has a thread groove 207a for moving the optical pickup unit 203 in the radial direction of the optical disc 400. The optical pickup unit 203 has a screw groove 2 of the lead screw 207.
A convex or spherical pickup guide 203a pressed by a spring member (not shown) so as to mesh with the pickup guide 203a.

As a result, the optical pickup unit 203
It moves in the axial direction of the lead screw 207, that is, in the radial direction of the optical disk 400, along the screw groove 207a formed in the lead screw 207.

[0010] By the way, as the information processing speed of the computer is improved, the reading speed of the information signal of the optical disk 400 or the recording speed of the information signal on the optical disk is also required of the optical disk device. Therefore, in order to quickly read necessary information recorded on the optical disc 400, efforts are being made to shorten the moving time of the optical pickup in the optical disc radial direction.

That is, the pits of the optical disk 400 mounted on the turntable 202a and rotating at a specified number of rotations are moved by the optical pickup unit 203 to the main rail 204.
And the pit reading accuracy when reading while moving along the sub-rail 205,
The perpendicularity between the 00 pit surface and the laser optical axis of the optical pickup unit 203 becomes important. As the perpendicularity deteriorates, coma aberration occurs in the beam spot of the laser from the optical pickup unit 203 on the pit surface (signal recording surface) of the optical disc 400, and the beam spot is deformed, and the pit reading accuracy decreases. I do. This causes a problem that the jitter value is deteriorated or servo is not applied.

The intersection angle between the pit surface (signal recording surface) of the optical disk 400 and the laser optical axis is called skew. There are two types of skew, tangential skew and radial skew. As shown in FIG. 5, the tangential skew refers to the angle of intersection of the laser optical axis with the pit surface of the optical disc 400 when viewed along the transport direction on the transport path of the optical pickup unit 203. As shown in 6,
This refers to the intersection angle of the laser optical axis with the pit surface when viewed from the side of the conveyance path of the optical pickup in a direction orthogonal to the conveyance direction.

The causes of the skew of the optical disk device 200 include the inclination of the laser emission axis of the optical pickup unit 203 and the guide rail bearing, the inclination of the base rail 201 and the main rail 204, and the inclination of the base chassis 201. Mounting plate 202 of rotation drive unit 202
b, the inclination of the turntable 20 of the rotation drive unit 202
2a and the parallelism between the mounting plate 202b, the optical disc 400
There is a tilt due to warpage. The last of these five items is a problem specific to the optical disk, and the remaining four items directly affect the optical disk device 200. However, keeping the dimensional accuracy achievable for the above four items within the standard values for skew improvement means that considerable cost burden is taken into account when considering mass production of the product. Near impossible. Therefore, most optical disk devices generally perform skew adjustment for optimally adjusting the relationship between the pit surface (signal recording surface) of the optical disk and the laser optical axis after assembling the components.

An example of skew adjustment of a conventional disk device will be described with reference to FIGS.

The mounting height of the main rail 204 on the side of the rotary drive section 202 (hereinafter referred to as the inner peripheral side) is fixed by a rail bracket 206. A rail height adjusting unit 211 and a rail guide 21 are provided at both ends of the main rail 204 on a side (hereinafter referred to as an outer peripheral side) away from the rotation driving unit 202.
0 is set. The sub-rail 205 has a rail height adjusting portion 211 and a rail guide 210 on both the inner and outer peripheral sides.
Is installed. The rail height adjusting unit 211 includes a concave portion for sandwiching the rail and a screw portion.
The rail height adjustment part 211 is assembled and fixed to a screw hole provided in the rail.

Each of the two rails regulates a deviation of the optical disk 400 in a tangential direction by a rail guide 210. Further, the deviation of the optical disc 400 in the radial direction is regulated by the rail height adjustment unit 211. The rail height adjustment unit 211 can arbitrarily change the mounting height from the base chassis 201 by rotating the rail, and the height of the outer periphery of the main rail 204 and the inner and outer sides of the sub rail 205. Can be adjusted respectively. The skew is adjusted to the optimum value by adjusting the height of the two rails to make the jitter value within the standard. After the height adjustment, the rail height adjustment unit 211 and the screw portion of the base chassis 201 are fixed using a screw lock or the like so that the rail height does not change. The skew is adjusted in this way.

[0017]

In the above-mentioned conventional optical disk apparatus, a mechanism for adjusting the rail height is provided at three locations in order to adjust the skew to the optimum. There is a problem that parts are required and the number of parts increases.

In addition, the tangential skew must be adjusted on the inner peripheral side, and the radial skew and tangential skew must be adjusted on the outer peripheral side.

Further, in order to move the optical pickup unit at high speed, it is necessary to increase the groove pitch of the lead screw. However, the fine feed amount of the optical pickup unit also increases. With the movement of the optical pickup unit, the optical pickup unit moves too much and cannot stop at the specified position. There was a problem of causing a reading error.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems and to provide an optical disk device for realizing an optimum skew and an optical disk device for realizing a high-speed movement of an optical pickup unit. .

[0021]

SUMMARY OF THE INVENTION To achieve the above object, the present invention provides two rails disposed on a base chassis, a rotary drive for rotating an optical disk, and a rotary drive provided by the rotary drive. An optical pickup unit for writing or reading a recording signal from or to a recorded optical disk, wherein the rotary drive unit and the optical pickup unit are movably installed on the two rails. is there.

Further, according to the present invention, two rails provided on a base chassis, a rotary drive for rotating an optical disk, and recording or reproducing of signals from the optical disk rotated by the rotary drive. An optical pickup unit, a first transport unit for moving the optical pickup unit in a radial direction of the optical disc, and a second transport unit for moving the rotary drive unit in a radial direction of the optical disc; Are rotated in opposite directions to move the rotation drive unit and the optical pickup unit on the two rails in opposite directions.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a plan view showing an embodiment of the optical disk device of the present invention, FIG. 2 is a side view of the optical pickup unit side from the feed motor side shown in FIG. 1, and FIG. It is the side view which looked at the subrail side from the main rail side.

The optical disk device 10 shown in FIGS.
0 denotes a base chassis 101, a rotation drive unit 102,
An optical pickup unit 103, a main rail 104, a sub rail 105, a rail bracket 106, and a main rail side lead screw 107 serving as a first transport unit.
, A sub-rail side lead screw 112 as a second conveying means, a feed motor 108, and a gear train 109.
, A rail guide 110, and a rail height adjustment unit 111.

The optical pickup unit 103 records a signal on a pit surface (signal recording surface) of the optical disk 400 by a laser beam, or reads (reproduces) a signal from the pit surface, and has bearing mechanisms on both sides. are doing. The optical pickup section 103 includes a convex or spherical pickup guide 103a pressed by a spring member (not shown) so as to mesh with the screw groove 107a of the main rail side lead screw 107.

The rotation drive unit 102 holds and rotates the optical disk 400, and has bearing mechanisms on both sides similarly to the optical pickup unit 103. Further, the rotation drive unit 102 includes a turntable 102a on which the optical disc 400 is placed and a turntable 10
2a, a drive unit 102c that rotates through the base chassis 101, and a turntable 102a and a drive unit 102c
And a rotary drive guide 102d having a convex shape or a spherical shape pressed by a spring member (not shown) so as to mesh with the screw groove 112a of the sub-rail side lead screw 112. Have been.

The optical pickup section 103 and the rotation drive section 102 are composed of a long-span bearing 103b of the optical pickup section 103 and one bearing 102e of the rotation drive section 102.
Through the main rail 104 and the optical pickup 103
By passing the bearing 103c having the shorter span of the above and the other bearing 102f of the rotary drive unit 102 through the sub rail 105, they are held on the same rail. That is, the rotation drive unit 102
And the optical pickup unit 103 are installed on the same rail (main rail 104 and sub rail 105).

The main rail 104 is fixed on the base chassis 101 at both ends by rail brackets 106 of the same kind. The sub rail 105 is fixed on the base chassis 101 on one side by a rail bracket 106 and on the other side by a rail guide 110 and a rail height adjusting unit 111.

Two lead screws 107 and 112
The base chassis is connected via a rail bracket 106 to two rails, that is, a main rail 104 and a sub rail 105, on the opposite side to the rotation drive unit 102 and the optical pickup unit 103, and in parallel with the two rails. It is fixed on 101. The feed motor 108 controlled by a system computer (not shown) is fixed to the base chassis 101 via a motor mounting plate 108b while gears are pressed into a motor shaft 108a. The rotation of the feed motor 108 is transmitted to the lead screws 107 and 112 via a gear train 109, and the lead screws 107 and 112 rotate. Two lead screws 1 depending on the combination of the gear train 109
07 and 112 rotate in opposite directions.

Pickup guide 103a meshing with screw groove 107a of main rail side lead screw 107
The optical pickup unit 103 having the
It moves in the axial direction of the lead screw 107 along a.

The rotary drive section 102 having a rotary drive section guide 102d that meshes with the screw groove 112a of the sub-rail side lead screw 112 moves in the axial direction of the lead screw 112 along the screw groove 112a.

The rotation direction of the lead screws 107 and 112 is the same as that of the feed motor 108 by the gear train 109, and the main rail side lead screw 107 is in the same rotation direction as the feed motor 108, and the sub rail side lead screw 112 is in the reverse rotation direction to the feed motor 108. Rotary drive unit 10 moved by lead screws 107 and 112
The light pickup unit 103 moves in the opposite direction.

Here, the adjustment of the laser optical axis of the optical pickup unit 103 alone is generally performed with reference to a plane formed by the bearing of the optical pickup unit 103.
In addition, the parallelism of the turntable surface of the rotation drive unit 102 is also adjusted with reference to a plane formed by the bearing of the rotation drive unit 102.

When the skew of the mechanical unit of the optical disk apparatus according to the present invention is confirmed, the rotation drive unit 102 and the optical pickup unit 103 are mounted on one main rail 104, and the rotation drive unit 102 and the optical pickup unit 103 Is the same as adjusted on the same basis. When the radial skew is divided into the radial skew and the tangential skew, the inclination of the laser optic axis with the pit surface of the optical disk does not change regardless of the position on the main rail 104. Need not be adjusted as in the current optical disk device. Regarding tangential skew, the sub rail 105 may be parallel to the main rail 104 and a plane may be formed by two rails.

For this reason, in the figure, if the rail height on the outer peripheral side of the sub-rail 105 is set to an arbitrary height by the rail bracket 106, the height of the other rail is adjusted, so that the main rail 104 is adjusted. For the sub rail 105
Are set in parallel. As described above, when the skew adjustment is strictly performed in the current optical disk device, it is necessary to adjust the rail height at three locations. However, in the optical disk device of the present invention, the rail height of only one of the sub rails 105 is required. It can be done with adjustment. For this reason, the skew adjustment accuracy is improved, which is advantageous for signal reading and signal recording on an optical disc.

Here, the operation of the optical disk device of the present invention will be described.

First, the rotation drive unit 102 and the optical pickup unit 103 are waiting at substantially the center of the main rail 104 and the sub rail 105. When the optical disc 400 is mounted on the rotation drive unit 102, the laser light of the optical pickup unit 103 is moved by the feed motor 108 to a required recording signal position recorded on the pit surface of the optical disc 400.

At this time, the rotation of the feed motor 108 is transmitted through the gear train 109 to the two lead screws 107 and 1.
12 is transmitted. Main rail side lead screw 1
07 and the sub-rail side lead screw 112 rotate in opposite directions, so that when the laser light of the optical pickup unit 103 moves from the inner peripheral side to the outer peripheral side of the pit surface of the optical disc 400, the rotation drive unit 102 and the optical pickup unit 103 move in directions away from each other, and move closer to each other when moving from the outer circumference to the inner circumference.

[0039]

As described above, according to the optical disk apparatus of the present invention, the rotation adjusting section and the optical pickup section are arranged on the two rails, so that the height adjusting section for precisely adjusting the skew is provided. Is reduced from three places to one place, complicated adjustment work and adjustment man-hours can be reduced, and skew adjustment accuracy can be improved. Further, since the number of rail height adjustment units is reduced by two, the number of components can be reduced, and the cost of the optical disk device can be reduced.

Further, since the rotary drive unit and the optical pickup unit are configured to be movable at the same time, the relative moving speed of the optical pickup unit 103 can be doubled by the feed motor 108 currently used. Thus, the reading speed of necessary data recorded on the optical disk can be improved.

Further, as compared with the conventional optical disk device in which the optical pickup unit and the rotary drive unit are separately moved by using two feed motors, the cost for one feed motor can be reduced and the control of two complicated motors can be achieved. Therefore, an inexpensive optical disc device can be realized.

Since the optical pickup can be moved at the same groove pitch as that of the existing lead screw, the feed speed can be increased without impairing the fine feed accuracy.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of an optical disk unit of the present invention.

FIG. 2 is a side view of the optical pickup device seen from the feed motor side shown in FIG. 1;

FIG. 3 is a side view of the sub rail viewed from the main rail illustrated in FIG. 1;

FIG. 4 is a plan view showing an example of a conventional optical disk unit.

5 is a side view of the optical pickup device side as viewed from the feed motor side shown in FIG. 4;

FIG. 6 is a side view of the sub rail viewed from the main rail illustrated in FIG. 4;

[Explanation of symbols]

REFERENCE SIGNS LIST 100 optical disk device 101 base chassis 102 rotation drive unit 103 optical pickup unit 104 main rail 105 sub rail 106 rail bracket 107 main rail side lead screw (first conveyance unit) 112 sub rail side lead screw (second conveyance unit) 108 feed motor 109 Gear train 110 Rail guide 111 Rail height adjustment unit

Claims (2)

[Claims] 1. A rail mounted on a base chassis, a rotary drive for rotating an optical disc, and an optical pickup for writing or reading recording signals from the optical disc rotated by the rotary drive. An optical disc device, comprising: the rotary drive unit and the optical pickup unit movably mounted on the two rails. 2. A rail, which is disposed on a base chassis, a rotary drive for rotating an optical disc, and an optical pickup for recording or reproducing signals from the optical disc rotated by the rotary drive. A first transport unit that moves the optical pickup unit in the radial direction of the optical disc, and a second transport unit that moves the rotary drive unit in the radial direction of the optical disc, and moves these transport units in opposite directions. 2. The optical disk device according to claim 1, wherein the optical drive device is rotated to move the rotation drive unit and the optical pickup unit on the two rails in opposite directions.