JPH0660382A - Inclination controller - Google Patents

Abstract

PURPOSE:To reduce the number of parts of an inclination controller of an objective lens used for optical information recording and reproducing to make this controller light-weight and thin. CONSTITUTION:A flat spring 40 is supported like a cantilever on a base 20, which is the reference for inclination control of an objective lens 7, at angles to the lengthwise direction and the direction perpendicular to the lengthwise direction. A control base 10 provided with the objective lens 7 is connected to the free end part of the flat spring 40. The flat spring 40 is bent and twisted, and the control base 10 is held by respective repulsive forces. The control base 10 is made horizontal by control screws 31 and 32.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an objective lens or the like provided in an optical information recording / reproducing apparatus for optically recording, reproducing, erasing information by irradiating a recording medium with a light beam. The present invention relates to a tilt adjusting device for adjusting the tilt of the.

[0002]

2. Description of the Related Art FIG. 2 shows an optical pickup device used in an optical recording / reproducing apparatus. This optical pickup device has an optical head 3 which irradiates a light beam 2 facing a recording medium 1b rotated around a vertical axis by a motor 1a. The optical head 3 includes a laser light source 4 that horizontally emits the light beam 2 and an optical path of the light beam 2
It has a mirror 5 which is converted over 0 degree and reflected on the optical disc 1, and an objective lens 7 which focuses the reflected light beam 2 on a recording medium 1b of the optical disc 1.

Further, the optical head 3 is provided with a linear motor 6, and the linear motor 6 serves to move the optical head 3 in a tracking direction indicated by an arrow A. When the optical disc 1 is a magneto-optical disc, a coil 1c for applying a magnetic field to the magneto-optical disc is provided in a portion located on the opposite side of the optical head 3 with the magneto-optical disc interposed therebetween.

In such an optical pickup device, in order to record information with high accuracy, it is necessary to irradiate the recording medium 1b of the optical disc 1 with the light beam 2 vertically. When the objective lens 7 is attached so as to be tilted with respect to the laser beam, an aberration occurs in the light beam traveling from the objective lens 7 to the optical disc 1, and it is not sufficiently focused on the track of the optical disc 1 to be originally irradiated, and the adjacent track Since the light beam 2 is also irradiated, airy ring (second maximum) of the light beam 2 occurs and crosstalk occurs.

For this reason, such an optical pickup device is equipped with an inclination adjusting device 8 for the objective lens 7 so that the light beam 2 can be guided to the track of the optical disc 1 in a focused state.

As shown in FIG. 3, the tilt adjusting device 8 for the objective lens 7 includes a base 60 that serves as a reference for adjusting the tilt of the objective lens 7, and the objective lens 7 that is mounted and tilts with respect to the base 60. And an adjustment table 70 that is supported so as to be capable.

The base 60 has a pair of support bases 63 and 63 arranged on one side with an appropriate gap, and each support base 63 on the side opposite to each support base 63. And a flat plate-shaped connecting portion 62 arranged so as to connect to each other. An adjustment table 70 provided with the objective lens 7 is supported on each support table 63. On the connecting portion 62, a pair of magnetic circuits 61 and 61 arranged at appropriate intervals with respect to the respective supporting base portions 63 are attached.

The adjusting table 70 includes the supporting table portions 63 of the base 60.
It has a long plate-shaped adjusting plate 73 supported on each. The central portion of the adjusting plate 73 is located on each support base 63, and the base ends of the leaf springs 72 and 72 are attached to the upper and lower surfaces of the central portion, respectively. Each leaf spring 72 extends so that its tip is located between the magnetic circuits 61, and the lens holder 71 is supported between the tip of each leaf spring 72.

The adjusting plate 73 of the adjusting base 70 is a support base 63.
A sphere 50 arranged above is supported so as to be tiltable in the entire circumferential direction, and a pin 51 erected on the base 60 prevents rotation in a horizontal plane. The adjusting base 70 is held from above by a holding metal fitting 53, which is supported on the base 60 by a screw 52, and two springs 54 interposed between the adjusting base 70 and the base 60.
And 54 are urged upward, and in this state,
It is connected to the base 20 by two adjusting screws 55 and 55. The adjusting screws 55 and 55 are respectively located on the X-axis and the Y-axis which are orthogonal to each other in the horizontal coordinate with the center of the sphere 50 as the origin, and penetrate the base 60 from below and are screwed into the adjusting base 70. There is. Each spring 54
Are externally fitted to the adjusting screws 55 and 55, respectively.

[0010]

In such a conventional tilt adjusting device, one of the adjusting screws 55 is rotated so that the tilt angle of the adjusting base 70 with respect to the base 60 is the origin of the center of the sphere 50. By adjusting the X direction of the XY coordinates, and rotating the other adjusting screw 55,
The tilt angle of the adjustment base 70 with respect to the base 60 is adjusted in the Y direction.

However, in such an inclination adjusting device, the adjusting base 70 is positioned on the base 60 by the sphere 50 and the pin 51, and the adjusting base 70 positioned on the base 60 is a holding metal fitting. It is held by 53 and each spring 55. Therefore, in such a configuration, the number of parts increases, and the increase in weight of the device becomes a problem. In addition, each spring 55 is connected to the adjustment base 10 and the base 20.
In order to interpose each spring 55, a space for interposing each spring 55 is required. Therefore, there is also a problem that the thinning of the device is hindered.

The present invention is to solve the above-mentioned conventional problems, and an object thereof is to provide a lightweight and thin objective lens tilt adjusting device capable of positioning and holding the adjusting table with a relatively small number of parts. To do.

[0013]

The tilt adjusting device of the present invention has a base that serves as a reference for tilt adjustment, and an adjusting base that is tiltably supported by the base, and adjusts the base. A device for adjusting the inclination of a base, the base end of which is attached to the base, and the free end of the base is biased against the base end by a bending force and a twisting force. A leaf spring connected to the adjusting table in a fixed state, and a first displacement adjusting means of the adjusting table with respect to the base due to a bending force of the leaf spring,
A second displacement adjusting means of the adjusting base with respect to the base by the twisting force of the leaf spring is provided, thereby achieving the above object.

[0014]

The adjusting base is positioned at a fixed position on the base by being connected to the free ends of the leaf springs supported by the base. Further, the adjusting base is held by the respective reaction forces of the bending and twisting of the leaf spring. Then, the bending force in the longitudinal direction of the leaf spring is adjusted by the first displacement adjusting means, and the inclination angle of the adjusting table with respect to the base in that direction is adjusted. Further, the second displacement adjusting means adjusts the twisting force in the direction perpendicular to the longitudinal direction of the leaf spring, and adjusts the inclination angle of the adjusting table with respect to the base in that direction.

[0015]

EXAMPLES Examples of the present invention will be described below. The tilt adjusting device of the present invention is used for adjusting the tilt of the objective lens 7 provided in the optical pickup device. As shown in FIG. 1, the tilt adjusting device includes a horizontal base 20 that serves as a reference for adjusting the tilt of the objective lens 7, and an adjusting table 10 that is equipped with the objective lens 7 and supported by the base 20. The plate spring 40 is provided between the base 20 and the adjusting table 10.

The base 20 has a pair of support bases 23 and 23 arranged on one side with an appropriate interval, and each support base 23 on the side opposite to each support base 23. And a flat plate-shaped connecting portion 22 that is arranged so as to connect to each other. The adjustment table 10 provided with the objective lens 7 is supported on each support table portion 23. A pair of magnetic circuits 21 and 21 are mounted on the connecting portion 22 so as to be spaced apart from the supporting base portions 23 at appropriate intervals. Each support pedestal 23 is in a state of projecting upward from the connecting portion 22, and an upper portion thereof is a pedestal portion 24 extending in a horizontal state so as to approach each other. A leaf spring support 27 that supports the leaf spring 40 is provided between the pedestal 24 and the magnetic circuit 21.

The adjusting table 10 has a long plate-like adjusting plate 13 supported on each pedestal portion 24 of the base 20. The central portion of the adjusting plate 13 is located on each pedestal portion 24, and the base ends of the leaf springs 12 and 12 are attached to the upper and lower surfaces of the central portion, respectively. Each leaf spring 12 extends so that its tip is located between the magnetic circuits 21, and between the tip of each leaf spring 12,
The lens holder 11 is supported. The lens holder 11 has a size that spreads to each side of the tip end portion of each leaf spring 12, and has a frame shape that is open upward and downward. Then, the objective lens 7 is attached to the center of the lens holder 11 with the tip end of each leaf spring 12 inserted therethrough. Each leaf spring 12 of the lens holder 11
A coil 15 for driving the objective lens 7 is installed in a protruding manner at a side portion of the coil 15. The coil 15 is inserted into a magnetic circuit 21 mounted on the base 20.

The adjusting plate 13 extending on each pedestal portion 24 of the base 20 is provided on one side with a screw hole 14 into which a first adjusting screw 31 is screwed in so as to vertically penetrate therethrough. . Then, the adjusting plate 13 provided with the screw hole 14
An insertion hole 25 through which the first adjustment screw 31 is inserted is provided in a vertical state in the pedestal portion 24 whose side portions face each other so as to face the screw hole 14 and penetrate the pedestal portion 24. The first adjusting screw 31 is slidably inserted into the insertion hole 25 of the pedestal portion 24 and the leaf spring 40 as described later, and is screwed into the screw hole 14 of the adjustment base 10.

The other pedestal portion 24 on the other side of the adjusting plate 13 is provided with a screw hole 26 into which the second adjusting screw 32 is screwed so as to vertically penetrate the pedestal portion 24. . Second adjusting screw 32 screwed into the screw hole 26
Extends upward from the screw hole 26 and is abutted against the side portion of the adjusting plate 13.

The leaf spring support 27 provided between the pedestal 24 provided with the insertion hole 25 and the magnetic circuit 21 has a quadrangular prism shape, and its upper surface is located outside the pedestal 24. From the corner portion located to the corner portion located on the inner side of the magnetic circuit 21 side, the inclined surface is inclined downward. In order to position the leaf spring 40, a surface of the pedestal portion 24 and a linearly cut surface from the surface to the magnetic circuit 21 side are formed on the inclined surface to form a T-shaped concave portion. A screw hole 28 extending perpendicularly to the inclined surface is provided at substantially the center of the recess.

On the inclined surface of the leaf spring support 27, a leaf spring 40 composed of a leaf spring is attached.
The leaf spring 40 has a T-shaped base end portion that fits into a T-shaped concave portion provided on the inclined surface and a tip end portion that extends from the T-shaped portion onto the pedestal portion 24 adjacent to the T-shaped base end portion. The front end portion is bonded to the lower surface of the side portion of the adjusting plate 13 provided with the screw hole 14. The distal end portion is connected to the base end portion by a connecting portion having a narrow width so that the distal end portion can be easily bent and twisted. A through hole 42 that is aligned with the screw hole 14 is provided at the tip of the leaf spring 40. Further, the T-shaped portion of the leaf spring 40 is provided with a through hole 41 which is aligned with the screw hole 28 provided in the leaf spring support 27, and the T-shaped portion of the leaf spring 40 is supported by the leaf spring. The mounting screw 4 is fitted into a T-shaped recess provided on the inclined surface of the table 27.
The leaf spring 40 is attached to the leaf spring support 27 by inserting 3 through the through hole 41 and screwing into the screw hole 28.

The tilt adjusting device having such a structure is assembled as follows. The screw hole 14 provided on one side of the adjusting plate 13 in the adjusting table 10 and the through hole 42 provided at the tip of the leaf spring 40 are aligned to adjust the adjusting plate 13 to each other.
On the lower surface of the side portion provided with the screw holes 14 of
Glue the tip of the. The T-shaped base end portion of the leaf spring 40 is provided on the inclined surface of the leaf spring support base 27.
The fitting screw 43 is inserted into the through hole 41 provided in the base end portion of the leaf spring 40 by fitting it into the letter-shaped recess, and is screwed into the screw hole 28 provided in the leaf spring support 27.

By screwing the mounting screw 43, the leaf spring 4
The base end portion of 0 is closely attached to the inclined surface of the support portion 27, and is supported on one side in the same inclined state as the inclined surface. At this time, the other side portion of the adjusting plate 13 is placed on the other pedestal portion 24, and the free end of the leaf spring 40 adhered to the lower surface of one side portion of the adjusting plate 13 is the free end. Is a leaf spring support base 2
The inclined surface is inclined like the inclined surface of No. 7. In such a state, the insertion hole 2 provided in the one pedestal portion 24
5, the first adjusting screw 31 is inserted from below, the through hole 42 of the leaf spring 40 is further inserted, and the screw is inserted into the screw hole 14 of the adjusting plate 13. As a result, the adjusting plate 13 moves the leaf spring 4
The adjusting plate 13 is pulled horizontally against the bending force of 0, and the adjusting plate 13 becomes horizontal with respect to the longitudinal direction of the plate spring 40. At this time, since the downward pulling force is applied on the extension line of the connecting portion of the leaf spring 40, the connecting portion of the leaf spring 40 only bends without twisting, and the tip end portion of the leaf spring 40 and the adjusting plate 13 are bent.
Is in a horizontal state with respect to the longitudinal direction of the leaf spring 40 in a state of being inclined in the longitudinal direction of the adjusting plate 13.

When the inclination of the leaf spring 40 in the longitudinal direction is adjusted by the first adjusting screw 31, the second adjusting screw 32 is screwed into the screw hole 26 from below the pedestal portion 24 provided with the screw hole 26. Get caught. When the tip of the adjusting screw 32 is brought into contact with the side portion of the adjusting plate 13, the side portion of the adjusting plate 13 is pressed upward against the twisting force of the leaf spring 40, and the length of the adjusting plate 13 is increased. The tilt of the direction is adjusted.

As described above, in the objective lens 7 mounted on the adjusting table 10, the tilt of the leaf spring 40 in the longitudinal direction is adjusted by the rotation operation of the first adjusting screw 31, and then the second adjusting screw 32 is rotated. The longitudinal inclination of the adjusting table 10 is adjusted by the operation.

[0026]

As described above, the tilt adjusting device of the present invention has the following features.
Since the leaf spring also serves as the positioning member and the holding member of the adjusting table, the number of parts is small and the weight of the entire apparatus can be reduced. Further, since the holding member of the adjusting table can be eliminated between the adjusting table and the base, this gap can be narrowed and the wall thickness can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of an objective lens tilt adjusting device of the present invention.

FIG. 2 is a schematic configuration diagram of an optical pickup including a tilt adjusting device.

FIG. 3 is an exploded perspective view of a conventional tilt adjusting device for an objective lens.

[Explanation of symbols]

 7 Objective Lens 10 Adjustment Base 20 Base 31 First Adjustment Screw 32 Second Adjustment Screw 40 Leaf Spring

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Tanaka 22-22 Nagaike-cho, Abeno-ku, Osaka-shi, Osaka

Claims (1)

[Claims] 1. An apparatus for adjusting the tilt of an adjusting table with respect to the base, comprising: a base that serves as a reference for tilt adjustment; and an adjusting table that is tiltably supported by the base. A plate having a base end attached to the base and a free end that is connected to the adjusting base in a state of being urged by a bending force and a twisting force with respect to the base end. A spring, a first displacement adjusting means with respect to the base of the adjusting base by a bending force of the leaf spring, and a second displacement adjusting means with respect to the base of the adjusting base by a twisting force of the leaf spring. A tilt adjusting device provided.