JPS6141131Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a device for recording optical information on a disk and for reproducing the recorded information, and particularly to a driving device for the optical system.

[Background of the invention] Conventionally, this type of device has used a rotatable reflector plate to direct the light beam to the appropriate position, and a converging lens has been moved up and down to adjust the diameter of the beam spot. There are devices that use control devices, but the configuration of the drive devices of these devices is complex, and delicate control of movable members is required to control minute light beams and beam spots.
In addition, there are many movable members, and the synergistic error becomes large, which requires correction.

[Purpose of the invention] In view of the above points, the present invention fixes each element of the optical system, moves the entire optical system to control the focusing and tracking of the light beam, and simplifies the driving device of the optical system. The purpose is to make the entire device thinner and to make each control reliable and easy.

[Summary of the invention] In order to achieve the above object, the invention uses an optical system consisting of a converging lens that converges a light beam onto a disk, and an optical element that guides the light beam to the disk and a photodetector element via the converging lens. The light beam is fixed to a storage body, one end of the storage body in a direction parallel to the radial direction of the disk is swingably supported on a frame, and the other end of the storage body in a direction parallel to the radial direction of the disk is supported. A first driving body is arranged to move the storage body up and down in the disk direction centering on the one end portion in accordance with a focus control signal detected from the detection element, and further includes a first driving body that moves the storage body up and down in the disk direction from the one end portion to the other end portion of the storage body. A second driving body is disposed on the side of the other end in the orthogonal direction to move the storage body laterally in a substantially horizontal direction with respect to the disk around the one end in accordance with a tracking signal detected from the photodetecting element. It is characterized by what it did.

[Embodiments of the invention] Preferred embodiments of the invention will be described below with reference to the drawings.

A fixing piece 3 extending from one end in the direction parallel to the radial direction (horizontal direction in the drawing) of the disk 20 of the storage body 2, that is, the right end 2a, of the storage body 2 that fixes the optical system to be described later is screwed to the frame 1. An elastic body 4 such as a spring or rubber is interposed in the middle of this fixed piece 3 to support the storage body 2 with respect to the frame 1 with flexibility. Further, at the other end of the storage body 2 in the direction parallel to the radial direction (horizontal direction in the drawing) of the disk 20, that is, the left end 2b, there is a magnet body 5 with one pole fixed to the outside, and a magnet body 5 on the left side of the frame body 1. A U-shaped iron core 6 facing the left end 2b of the storage body 2 is located in the section, and this iron core 6
A first driving body 8 consisting of a wound coil 7 is disposed at the center of the coil 7. Further, in the vicinity of the converging lens 9 provided in the storage body 2, and on both sides of the storage body 2 in a direction perpendicular to the right end 2a to the left end 2b, there are magnets 10 with the same polarity facing outside. 11, and furthermore, the end portions 12a,
The second driving body 14 is composed of a U-shaped iron core 12 in which the 12b are opposed to each other, and a coil 13 wound around the center of the iron core 12. This second driving body 14
will be placed on the left side of the frame 1.

As shown in FIG. 5, the optical system fixed to the storage body 2 is configured such that a light beam emitted from a light source 15 is transmitted through a lens 1.
6. The polarized beam is transmitted through the polarizing beam splitter 17 and the λ/4 plate 18, and then the converging lens 9 is passed through the reflecting prism 19.
The reflected beam from the disk 20 is transmitted through the converging lens 9, the reflective prism 19, and the λ/4 plate 18, and is sent to the polarizing beam splitter 17 in a direction approximately 90 degrees different from the light beam. is reflected to the photodetecting element 22 via the lens 21.
It is made so that it is incident on .

Then, the positional deviation of the light beam from the proper position with respect to the disk 20 is used as a tracking signal,
In addition, a known means is employed in which the change in diameter of the beam spot of the light beam that irradiates the disk changes from an appropriate diameter as a focus control signal, which can be detected optically by the photodetector element 22.

A screw 24 having an elastic body 23 such as a spring or rubber fixed to the head is screwed onto the side wall of the frame 1 to prevent the storage body 2 from over-rotating, and the storage body 2 has the converging lens 9 fixed thereto. An elastic body 25 such as a spring or rubber is arranged between the lower wall and the frame 1 to support the storage body 2.

To explain the operation of the above embodiment, the magnet body 5 is always attracted by the first drive body 8 in the storage body,
Furthermore, since the right end 2a is fixed to the frame 1 by the fixing piece 3, it is kept substantially horizontal with respect to the disk 20. If the light beam deviates from its proper position or the diameter of the beam spot changes due to eccentricity of the disk 20, etc., this change appears as an optical change on the photodetector element 22, which is converted into an electrical signal. Then, the change in the beam spot diameter is inputted as a focus control signal to the coil 7 of the first driving body 8, the magnetic force of the iron core 6 is changed, the attractive force of the magnet body 5 is controlled, and the storage body 2 is moved to the fixed piece. 20 disks centered around 3
The beam spot diameter is controlled to maintain the beam spot diameter at an appropriate diameter. On the other hand, the change when the light beam deviates from the proper irradiation position is inputted as a tracking signal to the coil 13 of the second driving body 14 to change the magnetic force of the iron core 12 and control the attractive force of the magnets 10 and 11. , the storage body 2 is laterally moved approximately horizontally with respect to the disk 20 around the fixed piece 3, and the irradiation position of the light beam is controlled.

The second embodiment shown in FIG. 3 will be briefly described by assigning common numerals to parts common to the above embodiments.A fixing piece 3 extending from the right end 2a of the storage body 2 is attached to the frame 1 by screwing. The left end 2b of the storage body 2 is held on the frame body 1 by the spring 26, and the disk 20 is
The storage body 2 is kept substantially horizontally. In addition, magnet bodies 1 are placed on both side walls of the storage body 2, as in the above embodiment.
0 and 11, and the magnet body 1 is attached to the left side of the frame body 1.
U with end portions 12a and 12b facing each other at 0 and 11
A character-shaped iron core 12 and a second driving body having a coil 13 wound around the center thereof are arranged. Further, a cylindrical coil 27 is fixed to the bottom cover of the left end 2b holding the converging lens 9 of the storage body 2, and a concave magnet 28 is fixed to the frame 1 with respect to this cylindrical coil 27.
A driving body 29 is configured.

Therefore, the tracking control is performed using the second driving body 14 and the magnet bodies 10 and 11 in the same way as in the above embodiment.
Focus control is performed by inputting a focus control signal to the cylindrical coil 27, and by the magnetic action between the cylindrical coil 27 and the concave magnet 28, the storage body 2 is moved in the direction of the disk 20. Do this by moving up and down.

The optical system to be housed and fixed in the storage body 2 may be modified in various ways based on various known configurations.

[Effects of the invention] The present invention is constructed as described above, and is easy to assemble by simply fixing each element of the optical system to the housing, and there is no need for each element of the optical system to move. The operation error is small, and the first driving body and the second
Since the drive body is arranged separately, its maintenance is easy and the drive body can be made thinner, which has great practical effects.

[Brief explanation of the drawing]

FIG. 1 is a front partial sectional view showing a first embodiment of the present invention, FIG. 2 is a side partial sectional view of the same embodiment, and FIG.
The figure is a partially sectional front view of the second embodiment, FIG. 4 is a partially sectional side view of the same embodiment, and FIG. 5 is an explanatory diagram showing one embodiment of the optical system. DESCRIPTION OF SYMBOLS 1... Frame body, 2... Storage body, 8... First driving body, 9... Converging lens, 14... Second driving body, 2
0...Disk, 22...Photodetection element.

Claims (1)

[Scope of utility model registration request] An optical system consisting of a converging lens that converges a light beam onto a disk, and an optical element that guides the light beam to the disk and a photodetection element via the converging lens is fixed to a storage body, and the optical system is fixed to a storage body in the radial direction of the disk of the storage body. One end portion in a parallel direction is swingably supported on a frame body, and the storage body is mounted on the other end portion in a direction parallel to the radial direction of the disk according to a focus control signal detected from the photodetection element. A first driving body that moves up and down in the direction of the disk centering on one end portion is disposed, and is further provided on the side of the other end portion in a direction perpendicular to the direction from the one end portion of the storage body to the other end portion. An optical system drive device for an optical information recording and reproducing device, comprising a second drive body that moves the storage body laterally in a substantially horizontal direction relative to the disk around the one end portion in accordance with a tracking signal detected from the element. .