JPS58155530A - Up, down, left and right shifting device of optical lens for optical pickup device - Google Patents

Abstract

PURPOSE:To make the thickness of an optical pickup device thin, by arranging a tracking driving section and a focus driving section in parallel with a disc on the same line via a tracking moving frame, a focusing parallel plate spring and an up/down and left/right moving section. CONSTITUTION:The tracking driving section comprising a tracking driving permanent magnet 17 and a tracking control square coil 18 is arranged in parallel with the forcus driving section comprising a couple of square forcus driving permanet magnets 11 and a focus controlling coil 14, and the disc D via a tracking moving frame 16, a forcusing parallel plate spring 15 and an up/down, left/ right shifting section 13, on the same line. Thus, the size H2 to the Z axis direction of the optical pickup device is decreased, and the thickness of the optical pickup device is made thin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for moving an objective lens vertically and horizontally in an optical pickup device. The present invention relates to a device for vertically and horizontally moving an objective lens of an optical pickup device, which is arranged parallel to and on the same line as a disk, and uses a pair of rectangular bar-shaped permanent magnets as focus drive permanent magnets.

An example of focus and tracking control in a conventional optical pickup device is shown in FIGS. 1 and 2.
According to this, focus (Z-axis direction) control is performed by a gear coil electromagnetic drive, and tracking (X-axis direction) control is performed by a near motor electromagnetic drive, and the object to be driven is the objective lens 1 in both cases. In other words, a cylindrical permanent magnet 4 to which the objective lens 1 is fixed is mounted on a tracking phase-parallel plate 6 mounted inside the lens barrel 2, and a voice coil 5 is provided around the center of the lens barrel 2, protruding from the middle part of the lens barrel 2. , and a cylindrical permanent magnet 4 and a voice coil 5 are respectively installed inside the upper part of the storage tube 6, inside the near motor electromagnetic drive section 7, and a voice coil electromagnetic drive section 8 installed inside the middle part of the storage tube 6.
The lens barrel 2 is held inside the housing barrel 6 using a focus parallel plate plate 9 having a circular hole in the center, and the voice coil 5 and the coil 10 in the linear motor electromagnetic drive unit 8 are arranged inside the storage barrel 6. The objective lens 1 is moved in the Z-axis direction or the X-axis direction depending on the direction and magnitude of the current flowing therein. In this way, the tracking drive section and the focus drive section are arranged in two stages perpendicular to the disk D.

In this prior art, the tracking phase parallel plate Nonone 6
In order to widen the tracking operation range, it is desirable to have a small Nonone constant, and in order to be self-sustaining, one with a somewhat large S Ne constant is required. Furthermore, metal is preferable because it is not affected by temperature changes. Taking all of the above into account, long metal plates are generally used. Therefore, the Z of the optical pickup device
The axial size Hl is large, which poses a problem in that the optical pickup device is large and heavy.

In addition, when the disk rotation driving motor nozzle and the optical pickup housing are on the same side, when picking up the inner circumference of the disk, the separation distance R between the optical axis and the outer surface of the optical pick-up housing in the disk radial direction is , it is preferable to make it as small as possible, but since the focus drive section consisting of the voice coil 5 and the voice coil electromagnetic drive section 8 and the objective lens 1 are arranged concentrically, the problem is that it cannot be made smaller beyond a certain point. was there.

This invention was made by focusing on the problems of the prior art, and it is possible to move the tracking drive section and the focus drive section to the disk via a tracking movement frame, a focus phase parallel plate plate, and an up/down/left/right movement section. The object of the present invention is to solve the above-mentioned problems by arranging the permanent magnets in parallel and on the same line, and by using a pair of rectangular bar-shaped permanent magnets as focus drive permanent magnets.

The present invention will be explained below based on the drawings.

FIG. 3 is an exploded oblique view showing one embodiment of the present invention.

It is a diagram.

First, the configuration will be described. Reference numeral 11 denotes a focus drive permanent magnet, which is a pair of square rod shapes. The focus drive permanent magnet 11 includes a permanent magnet piece 11A having a rectangular cross section, a magnetic piece 11B having a rectangular cross section larger than the permanent magnet piece 11A fixed to the upper surface of the permanent magnet piece 11A, and a magnetic piece 11B fixed to the lower surface of the permanent magnet piece 11A. A gap 11D is formed between the magnetic pieces 11B and 110. The focus drive permanent magnet 11 is fixed inside both side walls 12A and 12B parallel to the tracking movement direction (X-axis direction) of the optical pickup housing 12.
Its longitudinal direction is parallel to the tracking movement direction (X-axis direction).

By using a pair of rectangular bar-shaped permanent magnets 11 for focus drive, the separation distance R2 between the optical axis and the outer surface of the optical pickup housing 12 shown in FIG. 4 can be made smaller than when using a cylindrical magnet.

16 is a vertically and horizontally moving section, which is a cube. A square coil 1 for focus control is disposed in the gap 11D of the permanent magnet 11 for focus drive in the middle part of the vertical and horizontal moving unit 16.
4 are protrudingly provided around the periphery, and an objective lens 1 is attached to the center part. Reference numeral 15 denotes a parallel plate spring for focusing, one end of which is fixed to the upper right end and the lower right end of the vertical and horizontal moving unit 16, and the right end 1 of the rectangular tracking movement frame 16.
6) The other end is fixed to the t-upper part and the lower right end 16R. And focus parallel plate panel 1
5 is the right end of the tracking movement frame 16, and the vertical and horizontal movement unit 1
6 is cantilevered and elastically supported freely in the focus movement direction (Z-axis direction). The focus (
This is to prevent the Z-axis of the objective lens 1 from tilting during Z-axis direction control. 17 is a permanent magnet for tracking drive.
It has the shape of a pair of square bars. Tracking drive permanent magnet 17
are fixed to the inside of both side walls 12A and 12B parallel to the tracking movement direction (X-axis direction) of the Marubiku Atsuzo 12,
Its longitudinal direction is parallel to the tracking movement direction (X-axis direction). 18 is a rectangular coil for tracking control, which is a permanent magnet 1 for tracking drive of the tracking moving frame 16.
A coil is wound inside the focus phase parallel plate groove 15 at a position opposite to the focus phase parallel plate groove 15 in a direction perpendicular to the tracking movement direction (X@ direction). In order to position the tracking control rectangular coil 18 inside the focus phase parallel plate 2 15, although not shown, cutouts may be provided in the upper and lower parts of both side walls 16S of the tracking movement frame 16, or Mounting pieces for the focus phase parallel plate 15 may be provided protruding from the upper and lower parts of the right end 16R of the tracking movement frame 16. Reference numeral 19 denotes a parallel plate for tracking, and the left end 16L of the tracking movement e'16 and Right end 16r
The intermediate portion is fixed to the outer wall, and both end portions are fixed to the inner sides of both side walls 12A and 12B of the optical shock absorbing unit 12. The tracking phase-parallel plates 19 elastically support the tracking movement frame 16 freely in the tracking movement direction (X-axis direction).

Note that both ends of the tracking parallel plate spring 19 are fixed to both side walls 12A of the optical pickup housing 12.

A mounting piece 12C may be provided protruding inside 12B.

In this way, the tracking drive unit consisting of the tracking drive permanent magnet U7 and the tracking control rectangular coil 18 moves the focus drive permanent magnet 11 and a focus control rectangular coil 14 are arranged parallel to and on the same line with the disk 1). Therefore, the size H2 in the Z-axis direction of the optical pickup device shown in FIG. 5 is reduced, and the optical pickup device can be made thinner.

The size of the focus control rectangular coil 14 in the longitudinal direction (X-axis direction) is determined so that the focus control rectangular coil 14 does not come into contact with the focus drive permanent magnet 11 during tracking movement (X-axis direction). In addition, the gap between the tracking drive permanent magnets 17 is such that when tracking movement (in the X-axis direction), the square coil 18 for tracking control
is set so that it does not come into contact with the tracking drive permanent magnet 17.

Next, the effect will be explained. When the focus error signal or the tracking error signal is zero, the square coil for focus control 14 or the square coil for tracking control 1
No current flows through the lens 8, and the objective lens 1 remains stationary at a predetermined position. If there is a focus error signal now, a current flows through the focus control rectangular coil 14.

Since the direction of this current and the direction of the magnetic flux from the focus drive permanent magnet 11 are perpendicular to each other, the focus control rectangular coil 14 receives a force in the vertical direction (Z-axis direction) based on Fleming's left hand rule.

The focus control rectangular coil 14 is integrated with the up/down/left/right moving unit 13 and elastically supported by the focus phase parallel plate plate 15, so that it can be moved in the up/down direction (Z-axis direction).
Move to. Therefore, the rectangular coil 1 for focus control
The objective lens 1, which is integrated with the objective lens 4 via the vertical and horizontal moving section 16, also moves in the vertical direction (Z-axis direction). Note that the moving direction and the moving area are determined by the direction and magnitude of the current flowing through the focus control rectangular coil 14. Next, when there is a tracking error signal, a current flows through the tracking control rectangular coil 18.

Since the direction of this current and the direction of the magnetic flux from the tracking drive permanent magnet 17 are perpendicular to each other, the tracking control rectangular coil 18 receives a force in the left-right direction (X-axis direction) based on Fleming's left-hand rule. The tracking sterilization rectangular coil 18 is integrated with the tracking moving frame 16, and is supported in the horizontal direction (X
Since it is elastically supported in the axial direction), it is elastically supported in the left-right direction (X
axial direction). Therefore, the objective lens 1 which is integrated through the tracking control rectangular coil 18, the tracking moving frame 16, the tracking phase parallel plate plate 19, and the up/down/left/right moving part 16 also moves in the left/right direction (X-axis direction).
Move to. The direction and amount of movement are determined by the direction and magnitude of the current flowing through the tracking control rectangular coil 18. Note that the focus error signal and the tracking error signal are generated by the semiconductor laser 20 as shown in FIG.
Collimator lens 21, polarizing beam splitter 22, '/4 wavelength plate 23.9o0 deflection mirror 24
, to the objective lens 1, and the reflected light from the disk D is returned to the polarizing beam splitter 22 in the reverse order, deflected by 90 degrees, and guided to the 4-split sensor via a light shielding plate and a converging lens (not shown).

As explained above, the present invention arranges the tracking drive section and the focus drive section parallel to the disk and on the same line via the tracking movement frame, the focus phase parallel plate nonone, and the up/down/left/right movement section. At the same time, by using a pair of rectangular bar-shaped permanent magnets as focus drive permanent magnets, the optical pickup device can be made thinner, and the distance between the optical axis and the outer surface of the optical pickup housing can be reduced. You can get the effect that you can.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the prior art, FIG. 2 is an exploded perspective view of a tracking drive unit of the prior art, FIG. 3 is an exploded perspective view showing an embodiment of the present invention, and FIG. 4 is an embodiment of the present invention. FIG. 5, which is a plan view showing an example, is a schematic sectional view taken along the line AA' in FIG. 4, including the optical system. DESCRIPTION OF SYMBOLS 1...Objective lens, 2...Lens barrel, 6...Tracking phase parallel plate plate, 4...Cylindrical water-filled magnet, 5
... Discoil, 6... Storage cylinder, 7... Linear motor electromagnetic drive section, 8... Voice coil electromagnetic drive section,
9... Parallel plate spring for focus, 10... Coil,
11... Permanent magnet for focus drive, 12... Optical pickup...Using, 16... Up/down/left/right moving unit,
14... Square coil for focus control, 15... Focus phase parallel plate nonone, 16... Tracking movement frame, 17... Permanent magnet for tracking drive, 18...
- Rectangular coil for tracking control, 19... Tracking phase parallel plate nonone, 20... Semiconductor laser, 21.
... Collimator lens, 22... Polarizing beam splitter, 26... 174 wavelength plate, 24... 90° deflection mirror Patent applicant Akai Electric Co., Ltd.

Claims (1)

[Claims] 1. A pair of rectangular rod-shaped focus drive permanent magnets made of a permanent magnet piece and a magnetic piece fixed to the inside of both side walls parallel to the tracking movement direction of the optical pickup housing, and a gap between the focus drive permanent magnets. A rectangular focus control coil that can be placed in the middle part is provided around the middle part, and an up/down/left/right moving part has an objective lens attached to the center part, and one end is fixed to the upper/lower right end of the up/down/left/right moving part. At the same time, the other end is fixed to the upper and lower right ends of the tracking movement frame to elastically support the vertical and horizontal movement parts, and a focus phase parallel plate plate is attached to the inside of both side walls parallel to the tracking movement direction of the pickup housing. A fixed pair of rectangular rod-shaped tracking drive permanent magnets, and a pair of fixed square rod-shaped tracking drive permanent magnets are arranged on the tracking movement frame at a position facing the tracking drive permanent magnets, inside the focus phase parallel plate and in a direction perpendicular to the tracking movement direction. A rectangular coil for tracking control is formed by winding a coil in the left end φ right end of the tracking movement frame, and the middle part is fixed to the outer wall of the left end φ right end of the tracking movement frame. A device for vertically and horizontally moving an objective lens of an optical pickup device, comprising a tracking phase parallel plate plate whose portion is fixed and elastically supports the tracking movement frame.