JP2672804B2 - Information reading device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an information reading device. 2. Description of the Related Art FIG. 4 shows a semiconductor laser (reference numeral 1) and an optical device which are arranged close to each other in a direction parallel to a medium surface of a recording medium (reference numeral 4). A configuration has been described in which a detector (reference numeral 5) is arranged on a substrate having a flange portion, and a hologram (reference numeral 8) is arranged so that a light beam emitted from a semiconductor laser passes through. However, in the device disclosed in this publication, the hologram is incorporated in the case (reference numeral 9) in such a manner that the semiconductor laser and the photodetector, which are integrally combined beforehand, are separated from each other. When the semiconductor laser and the hologram are separately incorporated as disclosed in the above publication, for example, after the both are incorporated in the case, the positional relationship between the optical axes of the two in a direction parallel to the medium surface is predetermined. Therefore, the adjustment work of relatively finely moving the two in the direction parallel to the medium surface is indispensable, and as a result, the assembling work of the information reading device becomes troublesome. As a solution to such a drawback, a semiconductor laser and a photodetector, which are arranged close to each other in a direction parallel to the medium surface of a recording medium, are arranged on a substrate having a flange portion, and the semiconductor laser and the light are detected. The PENCOM INTERNAT is a device that integrates the detector and hologram into a unit.
It is known as Model 60 manufactured by IONAL. However, the above-mentioned PENCOMINTERNATION
The model 60 manufactured by AL Co., Ltd. includes the alignment of the optical head member (hologram unit) and the objective lens in the direction perpendicular to the objective lens optical axis, and the alignment of the optical head member and the objective lens in the objective lens optical axis direction. There is no explanation of how to do it. [Problems to be Solved by the Invention]
No. 192121 (entire sentence) FIG. 2 shows a through hole formed in a movable member, a semiconductor laser (reference numeral 12) is arranged on a substrate having a flange portion, and the flange portion is used for the through hole. A combined device is described. The engagement is
The inner surface of the through hole and the outer peripheral surface of the flange portion are in contact with each other, and the flat surface where the through hole is formed and the flat surface of the flange portion which is perpendicular to the emission optical axis of the semiconductor laser. [0006] However, Japanese Utility Model Application Laid-Open No. 60-192121.
The apparatus disclosed in FIG. 2 discloses a diffraction grating (reference numeral 11) for directing three beams to a recording medium separately from a semiconductor laser and an objective lens (reference numeral 8).
PENCOM INT described above for the configuration in which
It is not possible to simply replace the semiconductor laser 12 with an optical head member in which a semiconductor laser, a photodetector and a hologram are integrally unitized, such as the model 60 manufactured by ERNATIONAL. Moreover, Japanese Utility Model 60-192121
In the configuration shown in FIG. 2, the alignment between the objective lens, the hologram, and the semiconductor laser is required.
As a result, there is a drawback that position adjustment during assembly becomes troublesome. An object of the present invention is to provide an information reading device which solves the above drawbacks. In order to read information recorded on a recording medium, an information reading apparatus of the present invention is a semiconductor which is arranged close to the recording medium in a direction parallel to the medium surface. A laser and a photodetector are arranged on a substrate having a flange portion, and a hologram is arranged so that a light beam emitted from the semiconductor laser passes through, and the semiconductor laser, the photodetector and the hologram are arranged. In an information reading apparatus including an integrated optical head member and a lens for irradiating the recording medium with a light beam emitted from the optical head member as convergent light, the information track is parallel to the medium surface. A circular through hole is formed in a movable member that linearly extends in a transverse direction and has a receiving portion that contacts a guide member fixed to a base, and the flange is formed in the through hole. And a focusing coil and a tracking coil are fixed to the lens to move the lens in the focusing direction and the tracking direction by the action of magnetic flux. The lens driving device described above is arranged on the movable member, and the engagement includes contact between the inner surface of the through hole and the cylindrical surface of the flange portion, and a plane perpendicular to the inner surface of the through hole and the flange portion. It is configured to be performed by contact with a plane perpendicular to the emission optical axis of the semiconductor laser in the above. An embodiment of the present invention will be described below with reference to the drawings. 1A to 1E show a first embodiment of the information reading apparatus of the present invention. Movable part body 1 having a substantially rectangular parallelepiped shape
Circular communication hole (through hole) that penetrates vertically in the center of
2 is open. PENCOM INTERNAT
An optical head 3 called an IONAL model 60 is attached to the upper surface (a plane where the through hole is formed) of the movable portion main body 1 in the flange portion 4 so as to be loosely fitted in the communication hole 2. More specifically, referring to FIG. 1A, the cylindrical surface of the flange portion 4 and the inner surface of the communication hole 2 are in contact with each other, and are perpendicular to the semiconductor laser emission direction of the flange portion 4 (vertical direction in the figure). The flat surface and the upper surface of the movable portion main body 1 (the flat surface perpendicular to the inner surface of the through hole) are engaged so as to come into contact with each other. A hollow coil support cylinder 6 is externally fitted to the rising portion 5 of the optical head 3, and a lens holder 7 having the same diameter is connected to the lower end of the coil support cylinder 6. The lens holder 7 is made of an aluminum material, and the objective lens 8 is fixed to the lower end. The outer surfaces of the coil support cylinder 6 and the lens holder 7 are shown in FIGS.
As shown in Fig. 2, each two wires 9A, 9B, 10A, 1
OB is fixed and each end of the wire is fitted in the wall surface of the communication hole 2. Inside the movable portion main body 1, there are rectangular parallelepiped internal spaces 11A and 11B orthogonal to the communication holes 2, and a pair of magnetic circuits 12A and 12B are installed in the spaces. The magnetic circuit 12A (12B) is composed of upper and lower permanent magnets and a non-magnetic material sandwiched between them. As shown in FIGS. 1A, 1B, and 1C, focusing coils 13A and 13B and tracking coils 14A and 14B are fixed to the side surface of the coil support cylinder 6. The focusing coils 13A and 13B are wound along the circumferential direction of the coil support tube 6. The tracking coils 14A and 14B are formed by overlapping a part of two coils wound in a square shape, and the shape thereof is shown in FIG. 1 (d). Guide rollers 17A to 17A are provided in a portion where the corner where the side surface of the movable body 1 and the upper surface or the lower surface intersect is cut off.
17D is fixed. These guide rollers 17A to 17D
Are in contact with the inclined surfaces of the prismatic guide members 18A and 18B extending along the moving direction of the movable portion main body 1, and smoothly guide the movement of the movable portion main body 1. Next, the operation of this embodiment will be described. Focusing coils 13A, 13
B, the positional relationship between the tracking coil 14B and the magnetic circuit 12B is shown in FIGS. Actually, the focusing coils 13A and 13B and the tracking coil 14
1A and 14B are fixed so as to be superimposed on the surface of the coil supporting cylinder 6 as shown in FIG. Coil 14
In order to make it easier to see the positional relationship between B, 13A and 13B and the magnetic circuit 12B, they are shown separately in FIGS. 1 (d) and 1 (e). To perform tracking, when a current is passed through the tracking coil 14B in FIG. 1 (d), the directions of the magnetic field and the current are reversed in the coil portions 20 and 21, so that a force in the same direction is generated and the objective The lens 8 is shown in FIG.
To move in the tracking direction indicated by the arrow. Next, focusing is performed in FIG.
When currents flow in the A and 13B in opposite directions, the magnetic flux from the magnetic circuit 12B crossing each coil also becomes in the opposite direction, and as a result, a force in the same direction is generated.
It is moved in the focusing direction shown by the arrow (e). In both cases of the tracking and focusing described above, the magnetic flux 22 generated by the magnetic circuit 12B is shown in FIG.
As described above, the upper N pole is crossed across the coil at a right angle, the coil is moved downward along the coil support cylinder 6, and then the coil is turned rightward to pass through the coil and return to the lower S pole. Although this description has been made with respect to the magnetic circuit 12B, the same operation is performed also with respect to the magnetic circuit 12A side, and the direction of the current is set so that the directions of the generated forces are aligned between the magnetic circuits 12A and 12B. do it. FIGS. 2A and 2B show a configuration in which the wires 9A, 9B, 10A and 10B of FIG. 1A are leaf springs, and the deformation of the wires supporting the lens holder 7 and the coil support cylinder 6 is shown. It is an example. In general, the movable range between focusing and tracking is about 10: 1, and therefore, in FIG. 2A, the ratio of the length of the focusing leaf spring 26 to the length of the tracking leaf spring 27 joined thereto is 10: 1. In FIG. 3B, the length ratio is set to 10: 1 while the length of the leaf spring is the same. FIG. 3 shows an embodiment of the optical head section 3. This optical system is PENCOM INTERNATIONAL
This is the optical system of Model 60 of the company. The light beam emitted from the laser 28 becomes parallel light by the collimator lens 29, passes through the hologram 30, and is condensed on the recording medium by the objective lens 8 in the actuator 31. The reflected light from the recording medium passes through the objective lens 8 again, and is condensed on the detector 32 by the collimator lens 29 deflected by the hologram 30. Further, the entire pickup section is lightweight,
If a sufficient frequency response characteristic can be obtained, the tracking operation may be performed by removing the tracking coil and driving the carriage. The shape of the recording medium is not limited, and may be card-like, for example. According to the information reading apparatus of the present invention, in order to read information recorded on a recording medium, a semiconductor laser and a photodetector which are arranged close to each other in the direction parallel to the medium surface of the recording medium are used. And a hologram on the substrate having a flange portion so that the light flux emitted from the semiconductor laser passes through, and the semiconductor laser, the photodetector and the hologram are integrated together. In an information reading apparatus having a lens for irradiating the recording medium as convergent light with a light beam emitted from the optical head member, a straight line parallel to the medium surface and transverse to the information track. A circular through hole is formed in a movable member that has a receiving portion that extends in a fixed direction and contacts a guide member fixed to the base, and the flange portion is engaged with the through hole. A lens driving device configured such that the light beam passes through the through hole, and a focusing coil and a tracking coil are fixed to the lens to move the lens in the focusing direction and the tracking direction by the action of magnetic flux. What is arranged in the movable member, the engagement, the contact between the inner surface of the through hole and the cylindrical surface of the flange portion, the plane perpendicular to the inner surface of the through hole and the semiconductor laser in the flange portion. The present invention is characterized in that it is configured to be performed by contact with a plane perpendicular to the emission optical axis, and has the following effects. The effect that the optical axis alignment between the emission optical axis of the semiconductor laser and the optical axis of the objective lens in the optical head member and the alignment between the objective lens and the optical head member in the optical axis direction of the objective lens becomes extremely simple. Play.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 (a), (b), (c), (d) and (e) are diagrams showing an embodiment of the present invention. FIGS. 2A and 2B are modified examples of an elastic support member. FIG. 3 is a diagram illustrating an optical system according to the present invention. [Description of Signs] 1 Movable part main body 3 Optical head 6 Coil support cylinder 7 Lens holder 13A Focusing coil 14B Tracking coil

Claims (1)

(57) [Claims] In order to read the information recorded on the recording medium, a semiconductor laser and a photodetector, which are arranged close to each other in a direction parallel to the medium surface of the recording medium, are arranged on a substrate having a flange portion, and the semiconductor is arranged. The hologram is arranged so that the light beam emitted from the laser passes through, and the semiconductor laser, the photodetector, and the hologram are integrated into an optical head member, and the light beam emitted from the optical head member is provided. In an information reading device equipped with a lens for irradiating the recording medium as convergent light, the information reading device is in contact with a guide member which is parallel to the medium surface and linearly extends in a direction crossing the information track. A circular through hole is formed in the movable member having a receiving portion, and the flange portion is engaged with the through hole so that the light flux passes through the through hole. A focusing coil and a tracking coil are fixed to the lens, and a lens driving device that moves the lens in the focusing direction and the tracking direction by the action of magnetic flux is arranged on the movable member, and the engagement is The contact between the inner surface of the through hole and the cylindrical surface of the flange portion, and the contact between the plane perpendicular to the inner surface of the through hole and the plane perpendicular to the emission optical axis of the semiconductor laser in the flange portion. An information reading device having the above-mentioned configuration.