JP3142983U - Optical pickup device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical pickup device having a configuration capable of suppressing an increase in component cost due to an increase in the number of components and an increase in assembly cost due to an increase in assembly man-hours.
An objective lens for converging laser light emitted from a laser light source on a signal recording surface of an optical disc, an actuator base for swingably supporting a lens holder that supports the objective lens, and drive control of the objective lens A flexible printed board having wiring and a cover 1 that covers the flexible printed board are provided. The cover 1 is integrally formed with a cantilever-shaped pressing portion 1B that presses a swing fulcrum of the actuator base.
[Selection] Figure 1

Description

  The present invention relates to an optical pickup device, and more particularly to a holding structure for an objective lens adjustment mechanism.

2. Description of the Related Art Conventionally, an optical pickup device that uses an optical disc as a recording medium has used an optical pickup device as means for reading and reproducing information signals recorded on the optical disc.
This optical pickup device condenses a laser beam emitted from a laser light source as a beam spot on a signal recording surface of an optical disc through an objective lens, and forms a pit row consisting of rows of minute irregularities on the signal recording surface. Read and play the recorded information signal.
That is, the optical pickup device collects a laser beam as a beam spot on the pit row and reads and reproduces an information signal by detecting the state of the reflected beam reflected from the pit row with a photodetector. is there.

By the way, when the laser beam is focused on the pit row of the optical disc as a beam spot through the objective lens, the optical axis of the objective lens is not maintained exactly perpendicular to the signal recording surface of the optical disc. Aberrations occur in the beam spots collected on the columns.
When aberration occurs in the beam spot, the laser beam is not accurately focused on each very small pit, and noise components are superimposed on the information signal to be read and reproduced, leading to deterioration of the reproduction characteristics, and reading and reproduction of the information signal is also possible. It may be impossible.

  Therefore, in an optical pickup device used in an optical disk player or an optical recording / reproducing apparatus, the laser beam is recorded on the optical disk signal recording so that the laser beam is accurately incident on the signal recording surface of the optical disk. Various devices equipped with an inclination adjustment mechanism (hereinafter referred to as “skew adjustment mechanism”) that makes it possible to adjust the inclination of the optical axis of the objective lens that is focused on the surface are used.

  As an example of a configuration relating to skew adjustment, as disclosed in Patent Document 1, the actuator base is supported so as to be swingable in the tangential direction with respect to the pickup base, and the actuator base is swingably provided with a coil spring. There is a configuration in which a lens holder that is maintained in an urged state is provided, and the adjustment in the tangential direction and the radial direction described above can be performed by a swinging operation of each member.

  FIG. 4 shows an example of a conventional optical pickup device incorporating the configuration disclosed in Patent Document 1. In FIG. 4, the optical pickup device 100 includes a lens holder 104 that holds an objective lens 101. The lens holder 104 is supported by a damper base 106 via a suspension spring 105 that allows displacement of the objective lens 101 in the focusing direction and the tracking direction. A plurality of suspension springs 105 extend from the damper base 106 so as to be parallel to each other and substantially perpendicular to the optical axis direction of the objective lens 101 on both sides of the lens holder 104. A lens holder 104 is connected. The lens holder 104 includes coils 102 and 103 that drive the objective lens 101 in the focusing direction and the tracking direction together with the lens holder 104. The coils 102 and 103 cause the lens holder 104 and the objective lens 101 to move in the focusing direction and the tracking direction by an electromagnetic force generated between the focusing magnet and the tracking magnet arranged to face these coils. When the lens holder 104 moves, the suspension springs 105 bend while maintaining a parallel relationship with each other, so that the lens holder 104 can be translated in the focusing direction and the tracking direction.

  The damper base 106 is supported so as to be swingable in the radial direction (the direction indicated by the arrow R) with respect to the actuator base 107 around the screw 107B. A screw 107 </ b> C is screwed from the lower surface side of the actuator base 107, and the tip of the screw 107 </ b> C protruding to the upper surface side of the actuator base 107 is in contact with the lower surface of one end portion of the damper base 106. Therefore, by adjusting the rotation of the screw 107C, the damper base 106 rotates about the screw 107B, and the inclination of the damper base 106 in the radial direction can be adjusted.

  The actuator base 107 is mounted on the pickup base 108, and the swing fulcrum portion 107A of the actuator base 107 is in contact with the swing fulcrum support portion 108A formed on the pickup base 108. The swing fulcrum portion 107A is formed in a partial arc shape. The swing fulcrum portion 107A slides along the support surface of the swing fulcrum support portion 108A, whereby the actuator base 107 is moved in the tangential direction (indicated by an arrow Ta). (In the direction shown) is swingably supported.

In such a configuration, when performing radial skew adjustment, the screw 107B is loosely tightened and the screw 107C is advanced and retracted so that the damper base 106 can swing in the radial direction R with respect to the actuator base 107.
At this time, one end of the lower surface of the damper base 106 is pressed against the tip of the screw 107C by the biasing force of the holding spring 109.

  By rotating the screw 107C from the lower surface side of the actuator base 107 and moving it forward and backward with respect to the actuator base 107, the contact height position of the damper base 106 and the tip of the screw 107B varies, and the damper base 106 is centered on the screw 107B. Swing as. Thereby, the radial skew adjustment of the damper base 106 is performed.

  After that, by tightening the screw 107B firmly, the damper base 106 is sandwiched and fixedly held between a pair of rising portions 107D provided on the actuator base 107 and also supporting the screw 107B.

The tangential skew adjustment is as follows.
Due to the biasing force of the holding spring 109, the actuator base 107 is pressed downward toward the pickup base 108, and the swing fulcrum portion 107A is always brought into contact with the swing fulcrum support portion 108A on the pickup base 108 side. Yes.

  In this state, when the screw 108B that is screwed in from the lower surface side of the pickup base 108 and protrudes toward the upper surface side of the pickup base 108 is rotated, the actuator base 107 can be swung with its rocking fulcrum portion 107A as a fulcrum. it can. The swing fulcrum portion 107A is formed in a partial arc shape, and the actuator base 107 can be swung with the center position of the partial arc as a fulcrum. By swinging the actuator base 107 in this way, tangential skew adjustment of the actuator base 107 is performed.

  As described above, the skew adjustment of the actuator base 107 employs a method of swinging using the swing fulcrum, and such a method is disclosed not only in Patent Document 1 but also in Patent Document 2.

JP 09-185831 A Japanese Patent Laid-Open No. 05-303749

Incidentally, a pressing member such as a leaf spring is used in the configuration used for skew adjustment so that the swing fulcrum of the actuator base does not change its position. The conventional presser spring 109 shown in FIG.
For this reason, when assembling the optical pickup device, for example, when using a flexible printed board in which a circuit pattern is printed on a flexible resin substrate, the swing fulcrum is pressed separately from the cover for pressing the flexible printed substrate. It is necessary to prepare a leaf spring. Therefore, since the leaf spring is processed as a separate part from the cover or the like and assembled as a separate part, the part cost, the processing cost, the number of assembly steps, and the like increase.

  An object of the present invention is to provide an optical pickup device capable of suppressing an increase in component cost due to an increase in the number of components, an increase in processing cost, and an increase in assembly cost due to an increase in assembly man-hours in view of the problems of the conventional optical pickup device described above. There is to do.

  In order to achieve the above object, the present invention provides an objective lens for converging laser light emitted from a laser light source onto a signal recording surface of an optical disc, and an actuator base for swingably supporting a lens holder that supports the objective lens. A flexible printed board having wiring for controlling the driving of the objective lens and a cover for covering the flexible printed board, and the cover has a cantilevered pressing portion for pressing the swing fulcrum of the actuator base. The most important feature is that they are integrally formed.

  A fastening portion for attaching the cover may be provided in the vicinity of the pressing portion.

  According to the present invention, since the pressing portion for pressing and holding the swinging fulcrum of the lens holder is integrally formed on a part of the cover, unlike the case where the pressing member is a separate member from the cover, The number of parts can be reduced. Thereby, parts management cost, processing cost, and assembly cost can be reduced.

  In addition, since one of the fastening portions used for attaching the cover is provided in the vicinity of the proximal end portion of the cantilever-shaped pressing portion, it is possible to prevent the free end of the pressing portion from being lifted. Thereby, the rocking fulcrum of the lens unit can be held at a fixed position, and skew adjustment can be performed with high accuracy.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is an external view showing a cover for holding a flexible printed board used in an optical pickup device according to the present invention.

  In FIG. 1, a cover 1 is a plate-like member having a cover surface 1A that is large enough to cover the entire surface of a flexible printed board (not shown), and a part of the cover 1 extends from one corner of the cover surface 1A. A cantilever-shaped pressing portion 1B is provided at the protruding position by integral molding, for example, by pressing.

  As shown in FIG. 2, the pressing portion 1 </ b> B is positioned on the upper surface of the swing fulcrum 3 </ b> A of the actuator base 3 and presses the swing fulcrum 3 </ b> A of the actuator base 3 toward the pickup base 5. For example, four suspension springs extend in parallel from an integral member of the actuator base 3, and the lens holder 2 is coupled to the tip of each suspension spring so that the lens holder 2 can be translated. is doing. Such support structures are well known.

The pressing portion 1B has a cantilever shape, and a concave step portion 1C in which the pressing portion 1B is raised is formed continuously with the cover surface 1A in the vicinity of the base end portion. A bolt insertion hole 1 </ b> C <b> 1 that is a fastening portion for attaching the cover 1 is formed.
As shown in FIG. 2, a bolt 4 for fastening the cover 1 is inserted into the bolt insertion hole 1C.

In the configuration as described above, as shown in FIG. 3, the cover 1 is disposed above the flexible printed circuit board provided in the optical pickup device 20.
The cover 1 has a swing fulcrum 3A provided on the actuator base 3 (in FIG. 3, for the sake of convenience, the swing fulcrum is shown on the end face of the damper base 3 for clarifying the position of the swing fulcrum) from above. The bolt 4 inserted into the bolt insertion hole 1 </ b> C <b> 1 provided in the concave step 1 </ b> C in a state of being pressed toward the pickup base 5 is fastened to the pickup base 5 by being fastened to the pickup base 5.

  Thereby, in addition to the original function of the cover 1, the pressing action which is a function different from the function of the cover can be obtained with one member. In particular, since the pressing portion 1B is integrally processed on a part of the cover 1, it is not necessary to prepare the pressing member again or to process it in a separate process, so that an increase in processing costs and component management costs can be suppressed. Can do.

  On the other hand, the fastening position of the bolt 4 is in the vicinity of the base end of the pressing portion 1B having a beam shape in the cover 1, and thus can be a position close to the free end of the pressing portion 1B. Thereby, the pressing force generated at the pressing portion 1B can increase the pressing force at the free end of the pressing portion 1B, that is, the pressing position, and can surely prevent the pressing portion 1B from being lifted by the reaction force at the time of pressing. .

  3, details are not described with reference numerals, but the lens holder 2 that holds an objective lens (for convenience, indicated by reference numeral 101 used in FIG. 4) as in the case of FIG. 4. The actuator base 3 is provided. Further, a focusing coil and a tracking coil are fixed to the lens holder 2. These coils together with a focusing magnet and a tracking magnet constitute a focusing control actuator and a tracking control actuator.

  As shown in FIG. 3, the optical pickup device 20 has two skew adjustment screws 22 and 23. A line connecting the swing fulcrum 3A and the center of the skew adjustment screw 22 and a line connecting the swing fulcrum 3A and the center of the skew adjustment screw 23 are substantially orthogonal to each other. Therefore, by adjusting the skew adjusting screws 22 and 23, the tilt in one direction of the actuator base 3 with respect to the pickup base 5 and the tilt in the direction perpendicular to this direction can be adjusted with the swing fulcrum 3A as a fulcrum. it can. Since the swing fulcrum 3A is formed in a spherical shape and is in point contact with the pickup base 5, adjusting one of the skews in the two directions does not shift the other adjustment position.

  In the above embodiment, the cover 1 has a function of covering the flexible printed circuit board. However, the present invention is not limited to this, and the light source cover is located above the actuator base and has functions such as dust proofing in the vicinity of the light source unit. It is also possible to target.

It is an external view which shows the cover used for the Example of the optical pick-up apparatus concerning this invention. It is a schematic diagram of the optical pick-up apparatus provided with the cover shown in FIG. It is an external appearance perspective view of the optical pick-up apparatus provided with the cover shown in FIG. It is a disassembled perspective view which shows the prior art example of an optical pick-up apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cover 1A Cover surface 1B Press part 1C Concave step part 1C1 Bolt insertion hole 2 Lens unit 3 Actuator base 4 Bolt 5 Pickup base 20 Optical pick-up device 22 Skew adjustment screw 23 Skew adjustment screw

Claims (2)

An objective lens for converging the laser beam emitted from the laser light source onto the signal recording surface of the optical disc;
An actuator base for swingably supporting a lens holder supporting the objective lens;
A flexible printed board having wiring for controlling driving of the objective lens;
With a cover that covers this flexible printed board,
An optical pickup device, wherein the cover is integrally formed with a cantilever-shaped pressing portion that presses the swing fulcrum of the actuator base.   The optical pickup device according to claim 1, wherein a fastening portion for attaching a cover is provided in the vicinity of the pressing portion.

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