JP2002170249A - Mechanism for regulating posture in rotating direction of optical parts of optical pickup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanism for regulating the position in the rotating direction of optical parts of an optical pickup which is simple in constitution, can be inexpensively manufactured and is yet capable of regulating the posture with high accuracy and ensuring the maintenance of the posture after the regulation. SOLUTION: This mechanism has a base 10 which mounts a diffraction granting 20 in a state movable to a rotating direction A, an internal thread section 12 which is formed at the base 10 so as to extend in a rectilinear direction C parallel with the tangent with respect to the rotating direction of the diffraction granting 20, external threads 30 which are screwed into the internal thread section 12, an optical parts side projecting part 22 which is so formed as to project into the peripheral surface of the diffraction grating 20 and a threads side recessed part 32 which is formed to recess on the peripheral surface of the external threads 30. The external threads 30 are screwed into or out of the internal thread section 12 and is thus moved in the rectilinear direction C, by which the rotation of the diffraction grating 20 in the direction A through the threads side recessed part 32 and the optical parts side projecting part 22 is made possible.

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 the orientation of an optical component in a rotation direction of an optical pickup used in an optical disk drive.

[0002]

2. Description of the Related Art High-precision mechanisms are required for optical disk drives in order to respond to recent demands for increasing the capacity of optical disks and increasing the speed of accessing optical disks. One method for satisfying such demands is to improve the dimensional accuracy of the component. However, it is practically difficult to further improve the manufacturing accuracy of the component as compared with the current situation. Therefore, in this method, only the parts that conform to the higher precision standards are selected from the parts manufactured with the current manufacturing precision, and as a result, the proportion of non-standard products in the part manufacturing is increased. This leads to an increase in cost.

Therefore, as a method of realizing a high-precision mechanism without improving the dimensional accuracy of a component, a method has been proposed in which the mounting position of the component can be adjusted so as to allow a certain degree of dimensional variation. I have.

One of the mounting positions of components to be adjusted in an optical disk drive is a rotation orientation of an optical component in an optical pickup, for example, a diffraction grating (GRT) or a laser diode (LD). If the orientation in the rotation direction is not adjusted to an appropriate value, a laser beam of a predetermined phase will not be irradiated on the optical disc, or a reflected light of a predetermined phase cannot be received by the light receiving element, and the optical pickup will not operate normally. Will not work. Therefore, a rotation direction / posture adjustment mechanism of an optical component in an optical pickup as shown in FIGS. 3A and 3B has been proposed and put into practical use.

Referring to FIGS. 3A and 3B, a mechanism for adjusting the orientation of the optical component in the rotation direction in the optical pickup is configured as follows. An accommodation recess 111 for accommodating the diffraction grating 120 in a rotatable manner is formed in the base 110 of the optical pickup. The base 110 also has a concave portion 112 communicating with the side surface of the concave portion 111. A concave portion 122 is formed on a side surface of the diffraction grating 120.

In the process of assembling and adjusting the optical pickup, first, the diffraction grating 12
0 and temporarily assemble the optical pickup. At this time, the diffraction grating 120 can rotate in the direction of arrow A.
Next, the operator comprises, directly or via a manipulator, a cylindrical main body 201 also shown in FIG. 4 and a protruding portion 202 protruding eccentrically from the center axis of the main body 201 on one end of the main body 201. The protrusion of the (tool) 200 is inserted into the recess 112 of the base 110 such that the protrusion 202 enters the recess 122 of the diffraction grating 120. At this time,
The jig 200 is rotatable in the direction of arrow B. And
The operator rotates the jig 200 little by little in the direction of the arrow B while measuring the diffraction state of the beam by the diffraction grating 120 with an appropriate measuring device directly or through a manipulator, and by using the projection 202 thereof. Recess 1
By pressing the side surface 22, the rotational orientation of the diffraction grating 120 is adjusted so that the diffraction state of the beam by the diffraction grating 120 becomes a predetermined state. The periphery of the diffraction grating 120 whose rotational direction is adjusted is fixed to the base 110 by an adhesive or a curable resin.

[0007]

By the way, in recent years, many electronic devices such as personal computers, game machines, etc., in addition to dedicated machines, have been equipped with DVDs (Digital Versatile Diodes).
sc) has been developed and sold as renewable. It goes without saying that these electronic devices capable of reproducing DVDs are equipped with DVD-compatible optical pickups. DVD is CD (Compact Disc) or CD-ROM
(CD-Read Only Memory), optical discs compatible with DVDs have a higher density than CDs or CD-ROMs.
More detailed optical adjustment is required as compared with the conventional optical pickup for ROM. For example, with respect to the attitude of the diffraction grating in the rotation direction, higher-precision adjustment and maintenance of the attitude-adjusted diffraction grating are required.

[0008] In response to such a demand, it is difficult to perform sufficiently high precision adjustment with the conventional rotation direction attitude adjustment mechanism including the example shown in FIG. For this purpose, the position accuracy and rigidity of each component of the optical pickup and the manipulator must be extremely high. This leads to an increase in the cost of the optical pickup and, consequently, the DVD playback device. In addition, since the maintenance of the diffraction grating whose attitude has been adjusted has conventionally depended only on the fixing action of the adhesive, there is a possibility that the diffraction grating may be deviated from a regular position during shipment or use after the adjustment.

Accordingly, an object of the present invention is to provide a simple configuration,
An object of the present invention is to provide a mechanism for adjusting the rotation direction of an optical component in an optical pickup, which can be manufactured at low cost, can perform high-precision posture adjustment, and can surely maintain the posture after the adjustment.

[0010]

According to the present invention, a light for adjusting the attitude of a substantially cylindrical optical component (20) in an optical pickup in a rotation direction (A) about the center axis of the cylinder is provided. Optical components in pickup (20)
In the rotation direction / posture adjusting mechanism, the optical component (2)
(0) is mounted in the rotation direction (A) so as to be movable, and the base is extended in a first direction (C) parallel to a tangent to the rotation direction of the optical component (20). A female screw part (12) formed in (10), a male screw (30) screwed into the female screw part (12),
An optical component-side convex portion or an optical component-side concave portion (22) formed so as to protrude or be concave on the peripheral surface of the optical component (20), and to be concave on the peripheral surface of the male screw (30). And a screw-side concave portion or a screw-side convex portion (32) formed so as to protrude from the female screw portion (12) by screwing the male screw (30) into or out of the female screw portion (12). By moving in the first direction (C), the optical components (32) and the optical component-side convex portions or the optical component-side concave portions (22) are passed through the optical component ( 20) is made rotatable in the rotation direction (A), thereby providing a rotation direction / posture adjustment mechanism of an optical component in an optical pickup.

Note that the reference numerals in the parentheses are provided to facilitate understanding of the present invention, and are merely examples, and it is a matter of course that the present invention is not limited to these.

[0012]

When the male screw 30 is rotated, the position of the screw side recess 32 in the linear direction C changes. As a result, the optical component side projection 22 engaged with the screw side recess 32 moves, and the diffraction grating 20 rotates in the direction A.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, with reference to the drawings, a mechanism for adjusting the rotation direction and posture of an optical component in an optical pickup according to an embodiment of the present invention will be described in detail.

Referring to FIG. 1, the present mechanism is applied to an optical pickup of a DVD drive, and is used as an optical component having a substantially cylindrical shape after an optical pickup assembly process, before shipment, after repair, or the like. This is a mechanism for adjusting the attitude of the diffraction grating 20 in the rotation direction A about the center axis of the cylinder.

The mechanism includes a base 10 mounted by housing the diffraction grating 20 in the housing recess 11 while being movable in the rotation direction A, and a linear direction C parallel to a tangent to the rotation direction A of the diffraction grating 20. A female screw portion 12 formed on the base so as to extend, and a male screw 30 screwed into the female screw portion 12
And an optical component-side convex portion 22 formed so as to protrude on the peripheral surface of the diffraction grating 20, and a screw-side concave portion 32 formed to be concave on the peripheral surface of the male screw 30. FIG.
In FIG. 1, the accommodation recess 11 and the outer periphery of the diffraction grating 20 are illustrated as having a relatively large interval, but this is merely drawn for convenience of description, and the interval is actually small.

Then, the male screw 30 is rotated in the rotation direction B in the female screw portion 12 to be screwed or screwed out and moved in the linear direction C, so that the screw side concave portion 32 and the optical component side convex portion 22 are formed. Through this, the diffraction grating 20 can be rotated in the rotation direction A.

Screw-side recess 32 and optical component-side protrusion 2
2 each have an involute tooth shape. Thereby, the backlash is small.

The male screw 30 has no screw head,
Since the concave portion for engaging the bit of a tool such as a driver or a wrench is formed on the end face, the size of the optical pickup is not increased.

Further, by appropriately designing the thread pitches of the female screw portion 12 and the male screw 30, the rotation amount of the diffraction grating 20 in the rotation direction A according to the rotation operation of the male screw 30 in the rotation direction B can be changed. It is possible to correspond to the adjustment accuracy of the direction and orientation adjustment.

In the adjusting step, the male screw 30 may be manually rotated by a worker using a tool, or may be mechanically rotated using a manipulator.

Next, the steps of assembling and adjusting the optical pickup will be described.

First, the diffraction grating 20 is housed in the housing recess 11 of the base 10, and the optical pickup is temporarily assembled.
At this time, the diffraction grating 20 can rotate in the rotation direction A. Next, the operator directly or through a manipulator engages a tool such as a screwdriver or a wrench at the end of the male screw 30 and measures the diffraction state of the beam by the diffraction grating 20 with an appropriate measuring device. By rotating the screw 30 in the rotation direction B and moving it in the linear direction C, the screw side recess 32
In addition, the diffraction grating 20 is moved in the rotation direction A via the optical component side convex portion 22, and the attitude of the diffraction grating 20 in the rotation direction is adjusted so that the diffraction state of the beam by the diffraction grating 20 becomes a predetermined state.

Screw side concave portion 32 and optical component side convex portion 2
Since each of the two has an involute tooth shape, there is substantially no backlash, and the diffraction grating 20 is fixed by the male screw 30 when the rotation direction posture is adjusted. Therefore, it is generally unnecessary to fix the adjusted diffraction grating 20 around the base 10 with an adhesive or a curable resin as in the related art. Also, when fixing with an adhesive or a curable resin or the like, the amount may be smaller than the application amount of the conventional adhesive or the like.

[Modification] Referring to FIG. 2, a modification of the rotation direction and posture adjustment mechanism of the optical component in the optical pickup according to the embodiment of the present invention is also applied to an optical pickup of a DVD drive. This is a mechanism for adjusting the attitude of the diffraction grating 20 as a substantially cylindrical optical component in the rotation direction A about the center axis of the cylinder after the assembly process of the optical pickup, before shipping, after repair, or the like.

The mechanism includes a base 60 mounted by housing the diffraction grating 70 in the housing recess 61 while being movable in the rotation direction A, and a linear direction C parallel to a tangent to the rotation direction A of the diffraction grating 70. A female screw portion 72 formed on the base so as to extend, and a male screw 80 screwed into the female screw portion 62
And an optical component side concave portion 72 formed so as to be concave on the peripheral surface of the diffraction grating 70, and a screw side convex portion 90 formed so as to protrude on the peripheral surface of the male screw 80. . Convex part 9
0 is manufactured in advance as a part separate from the male screw 80,
It is attached to the male screw 80. In FIG. 2,
Although it is illustrated that the accommodation recess 61 and the outer periphery of the diffraction grating 70 have a relatively large space therebetween, this is merely drawn for convenience of description, and the space is actually small.

Then, the male screw 80 is rotated in the rotation direction B in the female screw portion 62 to be screwed or screwed out and moved in the linear direction C, so that the screw-side convex portion 90 and the optical component-side concave portion 72 are formed. Through this, the diffraction grating 70 can be rotated in the rotation direction A.

Screw-side convex portion 90 and optical component-side convex portion 7
2 each have an involute tooth shape. Thereby, the backlash is small.

The male screw 80 has no screw head,
Since the concave portion for engaging the bit of a tool such as a driver or a wrench is formed on the end face, the size of the optical pickup is not increased.

Further, by appropriately designing the thread pitches of the female screw portion 62 and the male screw 80, the rotation amount of the diffraction grating 70 in the rotation direction A according to the rotation operation of the male screw 80 in the rotation direction B can be changed. It is possible to correspond to the adjustment accuracy of the direction and orientation adjustment.

In the adjusting step, the male screw 80 may be manually rotated by a worker using a tool, or may be mechanically rotated using a manipulator.

Next, the steps of assembling and adjusting the optical pickup will be described.

First, the diffraction grating 70 is housed in the housing recess 61 of the base 60, and the optical pickup is temporarily assembled.
At this time, the diffraction grating 70 can rotate in the rotation direction A. Next, the operator directly or through a manipulator engages a tool such as a screwdriver or a wrench at the end of the male screw 80, and measures the diffraction state of the beam by the diffraction grating 70 with an appropriate measuring device. By rotating the screw 80 in the rotation direction B and moving it in the linear direction C, the screw-side protrusion 90
In addition, the diffraction grating 70 is moved in the rotation direction A via the optical component side concave portion 72, and the attitude of the diffraction grating 70 in the rotation direction is adjusted so that the diffraction state of the beam by the diffraction grating 70 becomes a predetermined state.

Screw-side convex portion 90 and optical component-side convex portion 7
Since each of the two has an involute tooth shape, there is substantially no backlash, and the diffraction grating 70 is fixed by the male screw 80 via the screw-side convex portion 90 at the time when the rotation direction posture is adjusted. . Therefore, it is generally unnecessary to fix the adjusted diffraction grating 70 around the base 60 with an adhesive or a curable resin or the like as in the related art. Also, when fixing with an adhesive or a curable resin or the like, the amount may be smaller than the application amount of the conventional adhesive or the like.

Although the embodiment of the present invention has been described above, the present invention is, of course, not limited to the above-described embodiment. For example, in the above-described embodiment, a case where the present invention is applied to a DVD drive device has been described as an example.
The present invention is not limited to this, but includes a CD-ROM drive, a CD-R drive, a CD-RW drive,
Alternatively, it is needless to say that the present invention can be applied to a DVD-RAM drive device.

[0035]

According to the present invention, there is provided a mechanism for adjusting the rotation direction and posture of an optical component in an optical pickup, comprising: a base on which the optical component is mounted so as to be movable in the rotation direction; A female screw portion formed on the base so as to extend into the female screw portion, a male screw screwed into the female screw portion, an optical component side convex portion or an optical component formed so as to protrude or dent on the peripheral surface of the optical component. A component side recess,
A screw-side concave portion or a screw-side convex portion formed so as to be depressed or projected on the peripheral surface of the male screw, and the male screw is screwed or screwed out in the female screw portion in the first direction. The optical component can be rotated in the rotational direction by moving the optical component through the screw-side concave portion or the screw-side convex portion and the optical component-side convex portion or the optical component-side concave portion. In addition, the posture can be adjusted with high accuracy, and the posture can be maintained after the adjustment.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a main part of a mechanism for adjusting a rotation direction attitude of an optical component in an optical pickup of the present invention.

FIG. 2 is a partial cross-sectional view showing a main part of a modification of the rotation direction / posture adjustment mechanism of the optical component in the optical pickup of the present invention.

FIGS. 3A and 3B are partial cross-sectional views showing a conventional optical component rotational direction posture adjustment mechanism, and FIGS. 3A and 3B are partial cross-sectional views.

FIG. 4 is a perspective view showing a jig used for a conventional optical component rotation direction posture adjusting mechanism.

[Explanation of symbols]

 10, 60, 110 Base 11, 61, 111 Housing recess 12, 62 Female screw 20, 20, 70 Diffraction grating 22 Optical component side convex 72 Optical component side concave 30, 80 Male screw 32 Screw side concave 90 Screw side convex Part 112 concave part 122 concave part 200 jig 201 main body 202 projecting part

Claims (4)

[Claims] 1. A mechanism for adjusting the orientation of a substantially cylindrical optical component in an optical pickup in the rotation direction of the optical pickup for adjusting the orientation of the optical component in a rotation direction about the center axis of the cylinder. A base mounted to be movable in the rotation direction, a first parallel to a tangent to the rotation direction of the optical component.
A female screw portion formed in the base so as to extend in the direction of, a male screw screwed into the female screw portion, and an optical member formed to protrude or be recessed on the peripheral surface of the optical component. A component-side convex portion or an optical component-side concave portion, and a screw-side concave portion or a screw-side convex portion formed so as to be recessed or protruding on a peripheral surface of the male screw; By moving in the first direction by screwing in or screwing out in the part, the optical component is passed through the screw side concave portion or the screw side convex portion and the optical component side convex portion or the optical component side concave portion. A rotation direction attitude adjustment mechanism for an optical component in an optical pickup, wherein the component is rotatable in the rotation direction. 2. The rotation of an optical component in an optical pickup according to claim 1, wherein the screw-side concave portion or the screw-side convex portion and the optical component-side convex portion or the optical component-side concave portion have an involute tooth shape. Direction and attitude adjustment mechanism. 3. The mechanism according to claim 1, wherein the optical component is a diffraction grating. 4. The male screw according to claim 1, wherein the male screw does not have a screw head, and a concave portion is formed on an end face for engaging with a tool for rotating the male screw. A mechanism for adjusting the orientation of the optical component in the optical pickup in the rotation direction.