JP2006012302A - Optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup device which is thinned without spoiling an expected effect of a cover body and reduced in manufacturing cost. <P>SOLUTION: The optical pickup device has an objective lens 25, an actuator 24, and a base frame 21 supporting the objective lens 25 and the actuator 24, and the base frame 21 has a cover body 21b covering at least a part of the actuator 24, formed integrally therewith. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical pickup device, and more particularly to an optical pickup device that records, reproduces, and erases information on a recording medium such as a compact disc and a digital versatile disc.

  An optical pickup device for recording, reproducing, and erasing information on a recording medium such as a compact disk (abbreviated CD: Compact Disk) and a digital versatile disk (abbreviated DVD: Digital Versatile Disk) has been put to practical use (for example, Patent Document 1). And 2). FIG. 2 is a cross-sectional view showing the main part of the first optical pickup device according to the prior art. The first optical pickup device includes a base frame 1, an actuator 2, a cover body 3, a light source and light receiving source 4, an objective lens 5, and an optical component 6. A cover body 3 is fixed to the base frame 1 by a claw or the like (not shown) attached to the cover body 3. That is, the cover body 3 and the base frame 1 are composed of separate parts. The cover body 3 is for restricting the movable range of the actuator 2 and protecting the objective lens 5 from dirt and scratches.

  FIG. 3 is a perspective view schematically showing the structure of the second optical pickup device according to the prior art. In the second optical pickup device, the sub-frame 8 that holds the actuator 7 is provided so as to face the recording medium 9, so that it also serves as a cover body. FIG. 4 is a perspective view schematically showing the structure of a third optical pickup device according to the prior art. In the third optical pickup device, the cover body can be omitted by providing the subframe 10 with a stopper 11 that restricts the movable range of the actuator.

JP-A-9-91727 JP 2001-229556 A

  In the first optical pickup device, since the cover body 3 and the base frame 1 are configured as separate parts, the number of parts of the entire device increases, which limits the thinning of the optical pickup device. As the number of parts of the entire device increases, the structure becomes complicated, which increases the manufacturing cost. Since the cover body 3 and the base frame 1 are composed of separate parts, it is necessary to allow for an attachment error of the cover body 3 with respect to the base frame 1. Therefore, the clearance δ between the recording medium and the cover body 3 cannot be reduced, and the device cannot be thinned.

  In the second optical pickup device, the subframe 8 that holds the actuator 7 is also used as a cover body. Therefore, when the skew adjustment of the actuator 7 is performed, the subframe 8 as the cover body is displaced together with the actuator 7. End up. Since the displacement amount of the sub-frame 8 must be expected, the clearance between the recording medium 9 and the sub-frame 8 cannot be reduced, and the device cannot be thinned.

  In the third optical pickup device, since the cover body itself is omitted, the objective lens 12 cannot be protected from dirt or scratches.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical pickup device capable of reducing the device thickness and reducing the manufacturing cost without impairing the intended effect of the cover body.

The present invention is an optical pickup device for performing at least one of recording, reproducing and erasing information on a recording medium,
Condensing means for condensing the light from the light source on the recording medium and guiding the return light from the recording medium to a predetermined optical component;
An actuator capable of moving and driving the light collecting means in a focus direction and a tracking direction with respect to the recording medium;
A base frame that supports the light collecting means and the actuator;
In the optical pickup device, the base frame is integrally formed with a cover body that covers at least a part of the actuator supported by the base frame.

  According to the invention, the condensing means condenses the light from the light source on the recording medium. The condensing means guides return light from the recording medium to a predetermined optical component. The actuator drives the condensing unit to move in the focus direction and the tracking direction with respect to the recording medium. The base frame supports the light collecting means and the actuator. A cover body is integrally formed on the base frame. The cover body is disposed so as to cover at least a part of the actuator. Since the cover body and the base frame are integrally formed in this way, the number of parts of the entire apparatus can be reduced as compared with the conventional structure in which the cover body and the base frame are separated.

  In the present invention, the base frame is provided with a hole for incorporating and supporting the actuator in the base frame.

  According to the present invention, the actuator can be incorporated into the base frame and supported by the base frame from the hole formed in the base frame. Conversely, the actuator can be easily removed from the hole in the base frame.

  In the invention, it is preferable that the cover body has a function of protecting the light collecting means.

  According to the present invention, the cover body can prevent the recording medium from colliding with the light collecting means when the recording medium is attached or detached. In this way, the light collecting means can be protected.

  In the invention, it is preferable that the cover body is configured to regulate a movement amount of the actuator.

  According to the present invention, the amount of movement of the actuator relative to the recording medium is regulated by the cover body.

  According to the present invention, a cover body is integrally formed on the base frame. The cover body is disposed so as to cover at least a part of the actuator. Since the cover body and the base frame are integrally formed in this way, the number of parts of the entire apparatus can be reduced as compared with the conventional structure in which the cover body and the base frame are separated. As a result, the structure of the optical pickup device can be simplified, and the manufacturing cost can be reduced. Also, the cover body can prevent dust and foreign matter from adhering to the actuator and the light collecting means as much as possible. In addition, according to the present invention, there is no need to consider the mounting error of the cover body with respect to the base frame as in the conventional separate structure. In other words, the manufacturing error of the cover body with respect to the base frame body can be much smaller than the conventional mounting error. Therefore, the clearance between the recording medium and the cover body can be made smaller than that of the conventional separate structure, and the device can be thinned.

  According to the present invention, the actuator can be incorporated into the base frame and supported by the base frame from the hole formed in the base frame. Therefore, since the trouble of fixing the claws of the cover body to the base frame as in the conventional case can be omitted, the assembly of the optical pickup device can be simplified. Conversely, the actuator can be easily removed from the hole in the base frame.

  Further, according to the present invention, the cover body can prevent the recording medium from colliding with the light collecting means when the recording medium is attached or detached. In this way, the light collecting means can be protected.

  According to the invention, the movement amount of the actuator relative to the recording medium can be regulated by the cover body. In other words, the cover body can be designed according to the amount of movement to which the actuator should be moved.

  FIG. 1 is a cross-sectional view of an optical pickup device 20 according to an embodiment of the present invention cut along a virtual plane including an axis line in the light collecting direction. This embodiment is an optical pickup device that performs at least one of recording, reproduction, and erasing of information on a recording medium such as a compact disk (abbreviated CD: Compact Disk) or a digital versatile disk (abbreviated DVD: Digital Versatile Disk). An example is shown. The optical pickup device 20 mainly includes a base frame 21, a light source and light receiving / receiving source 22, an optical component 23, an actuator 24, an objective lens 25, an unillustrated integrated circuit and a flexible substrate. Among these, the light source and light receiving source 22 and the integrated circuit are mounted on a flexible substrate.

  On the base frame 21, the light source and light receiving source 22 (hereinafter referred to as the light source 22), the optical component 23, and the actuator 24 are mounted, that is, supported. The optical pickup device 20 is supported so as to be movable along the radial direction of the recording medium 26 supported at a predetermined position. The radial direction is defined as the Y direction, the height direction of the optical pickup device 20 is defined as the Z direction, and the direction perpendicular to the Y direction and the Z direction is defined as the X direction. Guide support portions 27 and 28 for moving the optical pickup device 20 along the radial direction, that is, the Y direction are formed at both ends of the base frame 21 in the X direction. The base frame 21 is formed with a recess 21 a that can accommodate the actuator 24. A damper holder 29 is fixed to the base frame 21, and an actuator 24 is supported via a plurality of damper wires 30 attached to the damper holder 29 so as to be elastically displaceable.

  The actuator 24 includes a subframe 31, a focus coil 32, a tracking coil 33, an actuator magnet piece 34, and a yoke 35. An objective lens 25 as a condensing means is integrally fixed to one surface of the subframe 31 of the actuator 24 facing the recording medium 26. The objective lens 25 is provided so as to condense light from the light source 22 and the like onto the recording medium 26. In the base frame 21, a rising mirror as an optical component 23 is disposed in the optical path between the objective lens 25 and the light source 22. That is, the light emitted from the light source 22 and the like is sequentially collected on the recording medium 26 via the rising mirror 23 and the objective lens 25. Return light (also referred to as reflected light) from the recording medium 26 is condensed on the light source 22 including the light receiving element via the objective lens 25 and the rising mirror 23 again. Of the actuator 24, the objective lens 25 can be driven to move in the Z direction (focus direction) and the Y direction (tracking direction) by the magnetic force that can be generated by the focus coil 32, the tracking coil 33, the actuator magnet piece 34, and the yoke 35. It has become.

  A cover body 21 b that covers most of the actuator 24 is integrally formed on one surface portion of the base frame 21 that faces the recording medium 26. The cover body 21b has a function of preventing the objective lens 25 from interfering with other devices and the recording medium 26, in other words, protecting the objective lens 25. Moreover, the cover body 21b is configured to regulate the movement amount of the actuator 24 and the movement amount of the actuator 24 in the focus direction and the tracking direction. The base frame 21 has a hole 21c for assembling and supporting the actuator 24 in the base frame 21. That is, a hole 21c communicating with the recess 21a is formed in a part of the bottom wall portion of the base frame 21 to which the rising mirror 23 is attached. The actuator 24 can be accommodated and supported in the recess 21a of the base frame 21 from the hole 21c, and the actuator 24 can be taken out from the hole 21c.

  According to the optical pickup device 20 described above, the base frame 21 is integrally formed with the cover body 21b. The cover body 21 b is disposed so as to cover at least a part of the actuator 24. Since the cover body 21b and the base frame 21 are integrally formed as described above, the number of parts of the entire apparatus can be reduced as compared with the conventional structure in which the cover body and the base frame are separated. As a result, the structure of the optical pickup device 20 can be simplified, and the manufacturing cost can be reduced. Further, the cover body 21b can prevent dust and foreign matter from adhering to the actuator 24 and the objective lens 25 as much as possible.

  Moreover, according to the optical pickup device 20 according to the present embodiment, it is not necessary to consider the mounting error of the cover body 21b with respect to the base frame 21 as in the conventional separate structure. In other words, the manufacturing error of the cover body 21b with respect to the base frame main body can be much smaller than the conventional mounting error. Therefore, the clearance δ between the recording medium 26 and the cover body 21b can be made smaller than that of the conventional separate structure, and the apparatus can be thinned.

  Since the base frame 21 is provided with a hole 21c for incorporating and supporting the actuator 24 in the base frame 21, the assembly of the optical pickup device 20 can be simplified. That is, the actuator 24 can be incorporated into the base frame 21 and supported by the base frame 21 through the hole 21 c formed in the base frame 21. Therefore, since the trouble of fixing the claws of the cover body to the base frame as in the conventional case can be omitted, the assembly of the optical pickup device 20 can be simplified. Conversely, the actuator 24 can be easily removed from the hole 21 c of the base frame 21.

  Further, since the cover body 21b has a function of protecting the objective lens 25, the cover body 21b can prevent the recording medium 26 from colliding with the objective lens 25 when the recording medium 26 is attached or detached. Thus, the objective lens 25 can be protected. Further, according to the optical pickup device 20 according to the present embodiment, the movement amount of the actuator 24 relative to the recording medium 26 can be regulated by the cover body 21b. In other words, the cover body 21b can be designed according to the amount of movement by which the actuator 24 should be moved.

  In the present embodiment, the light source, the optical component, and the actuator are mounted on the base frame, but it is not necessarily limited to such a configuration. For example, a structure in which a light source is not mounted on the base frame may be used. According to this structure, it is possible to further reduce the thickness of the pickup device. It is also possible to mount a light source for CD and a light source for DVD on the base frame. As the light source, a light emitting element and a light receiving element integrated may be applied, or a light emitting element and a light receiving element separated may be applied. The one surface portion of the cover body and the one surface portion of the guide support portion are not necessarily formed to be flush with each other. The optical component is not limited to the rising mirror.

It is sectional drawing which cut | disconnected the optical pick-up apparatus 20 which concerns on embodiment of this invention, and cut | disconnected by the virtual plane containing the axis line facing a condensing direction. It is sectional drawing which shows the principal part of the 1st optical pick-up apparatus based on a prior art. It is a perspective view which shows schematically the structure of the 2nd optical pick-up apparatus based on a prior art. It is a perspective view which shows schematically the structure of the 3rd optical pick-up apparatus based on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Optical pick-up apparatus 21 Base frame 21b Cover body 23 Optical component 24 Actuator 25 Objective lens 26 Recording medium

Claims (4)

An optical pickup device for performing at least one of recording, reproduction, and erasing of information on a recording medium,
Condensing means for condensing the light from the light source on the recording medium and guiding the return light from the recording medium to a predetermined optical component;
An actuator capable of moving and driving the light collecting means in a focus direction and a tracking direction with respect to the recording medium;
A base frame that supports the light collecting means and the actuator;
An optical pickup device, wherein a cover body that covers at least a part of the actuator supported by the base frame is integrally formed on the base frame.   The optical pickup device according to claim 1, wherein the base frame has a hole for incorporating and supporting the actuator in the base frame.   The optical pickup device according to claim 1, wherein the cover body has a function of protecting the light collecting means.   The optical pickup device according to claim 1, wherein the cover body is configured to regulate a movement amount of the actuator.

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