JPS6257130A - Optical head - Google Patents

Abstract

PURPOSE:To curtail the number of parts of an adjusting mechanism and to improve the positioning accuracy by constituting an optical head body and a bearing block, of an integral formed body, and also constituting the optical head body so that it is supported so as to be freely turnable in two orthogonal directions. CONSTITUTION:An optical head body 10 which has been loaded with an optical system, an objective lens, etc., and a bearing block which has been supported by a guide shaft 11 are constituted of an integral formed body of plastic. Also, they are constituted so that an inclination adjustment centering around an extending direction (direction X) of the shaft 11 and an inclination adjustment centering around an axis (direction Y) being orthogonal to the shaft 11 can be executed. The inclination adjustment centering around the axis being orthogonal to the shaft 11 is executed by an X direction bearing 12, and the inclination adjustment centering around the extending direction of the shaft 11 is executed by adjusting a height adjusting screw 14 against a guide rail 13. By constituting the optical head in this way, the number of parts of the inclination adjusting mechanism of the optical head can be curtailed, also the adjustment can be executed from two directions against the body 10 and the shaft 11, and the positioning accuracy can be improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an optical head for recording and reproducing information on and from optical recording media such as optical discs such as compact discs and video discs, and optical recording media such as magneto-optical discs. It is something.

[Conventional technology]

2. Description of the Related Art Optical information recording and reproducing devices that record and reproduce information by projecting a light beam onto an optical recording medium such as an optical disk have been put into practical use. In this optical information recording/reproducing device, a light source projects a light beam.

An optical system consisting of various optical elements, an objective lens that projects a light beam as a spot toward the recording medium, a photodiode that receives the reflected light beam from the recording medium, etc. are mounted on the optical head, and this optical head is mounted concentrically. The recording medium is configured to record or reproduce information by moving in the radial direction of a recording medium on which information tracks are formed in a spiral or spiral shape.

Further, the optical head is provided with a bearing body for transporting the optical head in the radial direction of the disk-shaped recording medium in parallel with the recording medium, and the recording/reproducing device is provided with a guide shaft extending parallel to the recording medium. The optical head is slidably supported by inserting the bearing body into the.

FIGS. 4A and 4B are diagrams showing the configuration of a conventional optical head guide mechanism. A light source and an optical system are mounted on the optical head main body 1, and an actuator 3 is mounted on the upper surface of the optical head main body 1 to drive the objective lens 2 in the focusing direction and in the tracking direction orthogonal thereto. A bearing block 4 is attached to the negative side of the optical head body 1, a bearing 5 is attached to the bearing block 4, and a guide shaft 6 is inserted through the bearing 5 to slidably support the optical head body. There is. In addition, the bearing block 4 of the optical head main body 1
A protruding piece 7 is attached to the opposite side, a height adjusting screw 8 is screwed onto this protruding piece 7, and this height adjusting screw 8 is slidably connected to a guide plate 9 extending parallel to the guide shaft 6. I'm letting you do it.

Then, by adjusting the height adjustment screw 8 with respect to the guide plate 9, the optical head main body l is rotated in the direction of arrow a or b about the guide shaft 6, so that the light beam from the objective lens 2 is The light is configured to be incident on the recording medium at an angle.

[Problem that the invention seeks to solve]

As described above, since several types of parts are combined in the optical head, the emission characteristics of the light beams are different from each other due to aberrations, angular deviations, etc. of the optical parts. Therefore, in order to make the light beam incident on the recording medium at the best angle, it is desirable to be able to adjust the guide shaft from two directions when mounting the optical head on the guide shaft. However, conventional optical heads can only be adjusted in one direction, and therefore have the drawback that the recording and reproducing characteristics may not be set to the best condition. Further, since the optical head main body and the bearing block are constructed as separate bodies, installation errors are likely to occur, and therefore, there is also a drawback that the positioning accuracy of the optical head with respect to the recording medium is deteriorated.

Therefore, an object of the present invention is to eliminate the above-mentioned drawbacks, and to enable adjustment of the optical head body with respect to the guide shaft from two directions.
It is an object of the present invention to provide an optical head that can make a light beam enter a recording medium at the best angle and has high positioning accuracy.

[Means for solving problems]

In the optical head according to the present invention, the optical head is slidably supported via a bearing member on a guide shaft extending parallel to a recording medium, and the optical head body and the bearing member are made of an integrally molded plastic body. This book is characterized in that the optical head main body is rotatably supported around a guide shaft and an axis perpendicular to the guide shaft.

As described above, in the present invention, the optical head main body and the bearing member are constructed as an integrally molded plastic body, and the optical head is supported rotatably around the guide shaft and the axis perpendicular to the guide shaft. Therefore, the number of parts of the members forming the bearing section can be reduced, and the positioning accuracy of the members forming the bearing section can be improved. Furthermore, the inclination of the optical head can be adjusted from two directions, allowing the light beam to be incident on the recording medium at the best angle.

〔Example〕

FIG. 1 shows the configuration of an embodiment of the optical head according to the present invention, FIG. 1A is a perspective view, FIG. 1B is a side view, and FIG. 1C is a cross-sectional view showing the configuration of the X-direction bearing. Figure, the first diagram is X
FIG. 3 is a cross-sectional view taken along a plane perpendicular to the guide shaft of the directional bearing. In the present invention, the optical head main body 10 on which an optical system, an objective lens, etc. are mounted, and the bearing block supported by the guide shaft 11 are made of an integrally molded plastic body. ) and an axis (Y direction) perpendicular to the guide shaft 11.

Tilt adjustment around the axis perpendicular to the guide shaft 11 is performed by an X-direction bearing provided on the right side of the optical head main body 11 when facing the paper, and tilt adjustment around the extending direction of the guide shaft 11 is performed on the left side. This is done by adjusting the height adjustment screw 14 with respect to the guide rail 13 extending parallel to the guide shaft provided in the height adjustment screw 14. The upper wall portion of the optical head main body 10 corresponding to the guide shaft 11 is used as a support wall 10a, and an adjustment screw 15 is screwed onto this support wall 10a, and the tip of this adjustment screw 15 is connected to the guide shaft 11 as shown in FIG. Slide it into contact with the Further, a protrusion 16 that protrudes in the same direction as the adjustment screw 15 is integrally formed on the support wall 10a at a position spaced apart from the adjustment screw 15 in the extending direction of the guide shaft 11, and the tip of the protrusion 16 is formed integrally with the support wall 10a. is brought into contact with the guide shaft 11. The tips of these adjustment screws 15 and protrusions 16 are both formed into spherical shapes to form the guide shaft 1.
Slide it on the surface of 1 without resistance. On the other hand, an elastic support piece 17 that presses the guide shaft 11 from the side opposite to the adjustment screw 15 and the projection 16 is integrally molded at a position approximately midway between the adjustment screw 15 and the projection 16 in the extending direction of the guide shaft 11. . Since plastic has elasticity, the elastic support piece can be easily integrally molded. With this configuration, the guide shaft 11 is elastically supported at three points from above and below in the plane including the guide shaft 11, so that by adjusting the height of the adjustment screw 15 with respect to the guide shaft 11, Based on the guide shaft 11,
The support wall 10a rotates in the direction a or b using the protrusion 16 as a fulcrum, and therefore the optical head main body 11 passes through the protrusion 16 and rotates around an axis perpendicular to the guide shaft 11. As a result, the angle of incidence in a plane including the tracking direction of the light beam incident on the recording medium is adjusted.

As shown in FIG. 1B, a guide portion 10b is integrally provided on the left side surface of the optical head main body 11, and a height adjustment screw 14 is screwed into this guide portion 10b. Guide rail 1 extending parallel to guide shaft 11
Slide it into contact with 3. With this configuration, by adjusting the height of the height adjustment screw 14 with respect to the guide rail 13, the optical head main body 10 rotates about the guide shaft 11 in the direction a or b, and the light is incident on the recording medium. The angle of incidence of the light beam in a plane including the information track direction can be adjusted. By configuring the optical head main body and the bearing block as an integral molded body in this manner, the positioning accuracy of the bearing member with respect to the guide shaft is improved, and the inclination of the optical head can be adjusted with high precision.

FIG. 2 is a diagrammatic sectional view showing the configuration of a modified example of the X-direction bearing. In this example, a tongue piece 20 that can be displaced with respect to the support wall 10a is integrally molded on the support wall 10a, the tip of the adjustment screw 15 is brought into contact with the tongue piece 20, and the tongue piece 20 is slid onto the guide shaft 11. Let them come into contact with you. The surface of the tongue piece 20 is made a smooth sliding surface. With this configuration, it becomes unnecessary to process the surface of the tip of the adjustment screw 15 into a spherical shape.

FIG. 3 is a diagrammatic sectional view taken along a plane orthogonal to the guide shaft 11, showing the configuration of another modified example of the X-direction bearing.

In this example, an elastic support piece 30 is integrally formed with the support wall 10a, facing the adjustment screw 15 with the guide shirt eye 1 as the center. The elastic support piece 30 is provided with an elastic force that acts on the guide shaft 11 in the direction of the adjustment screw 15. With this configuration, a bearing is formed by the protrusion 16, the adjustment screw 15, and the elastic support piece 30, and by adjusting the adjustment screw 15, the elastic support piece 30 is elastically deformed to perform adjustment.

In particular, if it is integrally molded with a plastic molded body, the X-direction bearing can be manufactured by a simple molding process.

〔Effect of the invention〕

As explained above, according to the present invention, the optical head main body holding the objective lens, optical system, etc. and the bearing block are configured as an integrally molded body, and the optical head main body can be rotated about the guide shaft. Since it is configured to be supported freely and rotatably around an axis perpendicular to the guide shaft, the number of parts for the optical head tilt adjustment mechanism can be reduced, and the positioning accuracy of the members that make up the bearing section can be improved. do.

Furthermore, since the optical head is configured to be able to adjust its inclination from the direction of the guide shaft and two directions orthogonal thereto, the light beam can be made incident on the recording medium at the best angle.

[Brief explanation of the drawing]

1A to 1D are diagrams showing the configuration of an embodiment of the optical head according to the present invention, FIG. 2 is a diagram showing the configuration of a modified example of the X-direction bearing, and FIG. 3 is a diagram showing another modified example of the X-direction bearing. FIG. 4 is a diagram showing the configuration of a conventional optical head. 10... Optical head main body 11... Guide shaft 12... X direction bearing 13... Guide rail 14... Height adjustment screw 15... Adjustment screw 1
6... Protrusion 17.30... Elastic support piece 20... Tongue piece Figure 1A Figure 2 16" Figure 4

Claims (1)

[Claims] 1. In an optical head that is slidably supported via a bearing member on a guide shaft extending parallel to the recording medium, the optical head main body and the bearing member are formed of an integrally molded plastic body, and An optical head characterized in that an optical head main body is rotatably supported around a guide shaft and an axis perpendicular to the guide shaft.