JPH076925U - Optical pickup device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a pickup device capable of surely closing an opening for inserting an optical element without increasing the number of parts. [Structure] An opening 101 for inserting an optical element, which is formed in an optical element block 100 having a light source and a light receiving element 56 built therein.
Is covered with the flexible substrate 130 for supplying power to the light source and the light receiving element 56.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an optical pickup device.

[0002]

[Prior art]

 An optical pick-up device used to pick up signals from a recording medium such as an optical disc irradiates light (laser light) generated by a light source onto the recording medium through an objective lens and reflects the light from the recording medium. A structure in which light is detected by a light receiving element via an objective lens is widely used. An optical system is provided between the light source and the objective lens, or between the objective lens and the light receiving element, which is configured by appropriately combining optical elements such as a half mirror, a collimator lens, or a reflecting prism. The above-mentioned light source, optical element, objective lens or light receiving element are usually combined in a block as one unit, and this block is used by being assembled in the main body of the device.

By the way, in this type of optical pickup device, in order to align the optical axes of the light emitted from the light source to the recording medium and the reflected light from the recording medium to the light receiving element, for example, after assembling the block, It is necessary to adjust the position and angle (incident angle and reflection angle) in the optical axis direction of the optical element. For this reason, the optical pickup device has a configuration in which an opening (insertion port) for mounting the optical element is provided.

[0004]

[Problems to be solved by the device]

 By the way, the performance of the optical element used in the optical pickup device is deteriorated due to adhesion of dust in the atmosphere. For this reason, a structure is generally used in which the above-mentioned opening is closed by covering it with a dedicated cover, or by pressing it against the base plate provided in the main body of the device to which the optical pickup device is assembled. ing.

However, in the structure in which the opening is covered with the cover dedicated to the insertion opening or pressed against the base plate as described above, a dedicated cover or a member for pressing and closing the base plate is required. Therefore, there is a problem that the number of parts increases, which causes a cost increase.

An object of the present invention is to provide a pickup device that can surely close the opening without increasing the number of parts as described above.

[0007]

[Means for Solving the Problems]

 In the optical pickup device of the present invention, in the optical pickup device in which light from a light source is irradiated onto a recording medium by an objective lens and reflected light from the recording medium is detected by a light receiving element, the light source, the recording medium, and the light receiving device. An opening for inserting an optical element that constitutes an optical system between the elements is covered with a flexible substrate.

Further, in the present invention, the optical element is a half mirror, and the flexible substrate is a flexible substrate for supplying power to the light source or the light receiving element.

Further, in the present invention, the light source, the optical element, the objective lens, and the light receiving element are provided in a block.

[0010]

[Action]

 With the structure in which the opening for inserting the optical element is covered with the flexible substrate as described above, it is not necessary to use a dedicated cover or press the opening against the base plate as in the conventional case.

[0011]

【Example】

 An embodiment of the optical pickup device of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an optical pickup device of an embodiment and a flexible substrate 130 for power supply which is covered with the optical pickup device. In the optical pickup device of this embodiment, an optical element block 100 formed by combining a light source, an optical element, an objective lens, a light receiving element 56, etc., is attached to a device body 110 and a fixing unit described later (see FIG. 3). 4, a fixed cover 120 such as a reference numeral 1) and a movable unit (the same reference numeral 2) is combined with each other. In this optical element block 100, an opening 101 for inserting the half mirror 50 is formed. Further, the mounting portions 102 and 103 of the flexible substrate 130 are also formed. In the illustrated example, the mounting portions 102, 103 are convex pieces, and the following mounting portions 132, 133 of the flexible substrate 130 corresponding thereto are holes, but in addition, for example, the mounting portions 102, 103 are formed as holes. In addition, the mounting portions 132 and 133 may be convex pieces.

The flexible substrate 130 is for feeding power to the light source and the light receiving element 56 built in the optical element block 100, and includes a power feeding portion 131 to the light source and a power feeding portion 134 to the light receiving element 56. There is. The power feeding part 131 is formed with a terminal hole 131a connected to a power feeding terminal (reference numeral 46c in FIG. 6) described later of the light source. The flexible substrate 130 is further provided with mounting portions 132 and 133 to the optical element block 100. The shape of the flexible substrate 130 is devised so as to cover the opening 101 when it is attached to the optical element block 100 described below.

FIG. 2 shows a state in which the flexible substrate 130 is attached to the optical element block 100. In this case, the mounting portions 132 and 133 of the flexible board 130 are fixed by, for example, being fitted to the mounting portions 102 and 103 of the optical element block 100, respectively, and the terminal hole 131a of the power feeding portion 131 is connected to the power feeding terminal (46c) of the light source. ). Although not shown, the power feeding section 134 is connected to the terminal of the light receiving element 56. In this attached state, the flexible substrate 130 covers the opening 101 of the optical element floc 100.

Next, a specific internal structure of the above optical element block 100 will be described.

In FIGS. 3 to 5, the fixed unit 1 is placed on the frame 10 formed by resin integral molding or the like. The fixed unit 1 is configured such that the outer yoke plate 18 and the inner yoke plate 20 are integrally connected by resin, and the support shaft 26 is integrally formed by resin. Further, the movable unit 2 is supported by the support shaft 26.

As shown in FIGS. 6 and 7, the frame 10 is provided with a press-fitting hole 10a formed substantially in the center of one longitudinal edge of the frame 10. Inside the press-fitting hole 10a, a light source 46 made of a semiconductor laser or the like is press-fitted, and a diffraction grating 48 arranged on the path of the laser light emitted from the light source 46 is provided. A half mirror 50 that reflects the laser beam laterally (leftward in FIGS. 6 and 7) is arranged on the path of the light passing through the diffraction grating 48. Further, on the path of the laser light reflected by the half mirror 50, a mirror 52 is arranged for reflecting the laser light upward and guiding it to the objective lens 16 and the optical disk 85. Then, the laser light reflected by the optical disk 85 goes backward through the objective lens 16 and the mirror 52, and further passes through the half mirror 50. A sensor lens 54 also serving as an optical wedge is arranged on the path of the transmitted laser light. Further, a light receiving element 56 composed of a photodiode or the like is arranged behind the sensor lens 54 (on the right side in FIGS. 6 and 7).

In FIG. 6, a step portion 10 b is formed inside the press-fitting hole 10 a into which the light source 46 is press-fitted. The press-fitting hole 10a has a large diameter portion on the light source 46 side and a small diameter portion on the diffraction grating 48 side with the step portion 10b as a boundary. The light source 46 has a collar portion 46a at the base thereof, and the outer dimension of the collar portion 46a has a predetermined dimension intersection with the outer dimension of the large diameter portion of the press-fitting hole 10a. Due to this crossing of the dimensions, the light source 46 can be moved within the press-fitting hole 10a by a low pressure input with a pressure input in a predetermined range. Further, when the light source 46 moves in the press-fitting hole 10a, the stepped portion 10b formed in the press-fitting hole 10a comes into contact with the collar portion 46a of the light source 46 and plays a role of a stopper. Movement of the light source 46 at is limited.

Further, a spherical recess 30 is formed in the inner bottom portion on the left side of the frame 10 in FIGS. Holes 58 and 60 are formed on the outside of the recess 30 at positions that form an angle of 90 ° with the center of the recess 30, respectively. A fork-shaped guide portion 62 is formed at the right end portion of the frame 10 in FIGS. The guide portion 62 sandwiches the guide shaft 64, so that the frame 10 is movably held along the guide shaft 64 in the vertical direction in FIG. 6, that is, in the radial direction of the optical disk.

On the other hand, in FIGS. 3 to 5, on the inner surface of the pair of partial cylindrical peripheral walls of the outer yoke plate 18, the focus drive magnet 22 and the tracking drive magnet 24 are fixed by adhesion or the like. . The drive magnets 22 and 24 are brought into contact with the upper surface of the jetty 44 to thereby position them in the direction of the support shaft 26. Thus, the fixed unit 1 is constructed.

In the fixed unit 1, the adjusting surface 32 of the base portion 28, which is a convex spherical surface, is dropped into the concave portion 30 of the frame 10, which is a concave spherical surface. Inclination adjusting screws 34 and 36 are inserted into the two holes 58 and 60 of the frame 10. These adjusting screws 34 and 36 are screwed into corresponding screw holes of the outer yoke 18.

Further, one end of the leaf spring 40 is fixed to the frame 10 by a mounting screw 42. The tip of the leaf spring 40 sandwiches the support shaft 26 from the screw hole of the outer yoke 18 and presses the farthest position. Therefore, by tightening or loosening the tilt angle adjusting screws 34, 36, the adjusting surface 32 is brought into sliding contact with the recess 30 while the elastic force of the leaf spring 40 or against this elastic force causes the center of the convex spherical surface of the adjusting surface 32 to move. And the tilt angle of the fixed unit 1 changes.

Therefore, as shown in FIG. 3, the tilt angle θr in one direction of the support shaft 26 can be adjusted by the adjusting screw 34. Further, as shown in FIG. 5, the tilt angle θj in the direction orthogonal to the tilt angle θr can be adjusted by the adjusting screw 36 located at a position 90 ° away from the adjusting screw 34 with respect to the support shaft 26. In this way, the tilt angle of the support shaft 26 with respect to the frame 10 can be finely adjusted.

On the other hand, the movable unit 2 is provided on the support shaft 26 so as to be movable in the direction of the support shaft 26 and rotatable about the support shaft 26. The movable unit 2 has a holding body 12 that is movable along the support shaft 26 and rotatable around the support shaft 26 by being inserted into the outer peripheral side of the support shaft 26. A holding frame for the objective lens 16 is integrally provided on the holding body 12, and a drive coil 14 is fixed thereto. The object lens 16 is located on the optical path of the laser light reflected by the mirror 52, focuses the laser light on the recording pits of the optical disk 85, and reflects the laser light from the optical disk 85. To guide to the mirror 52.

The drive coil 14 is a sheet-shaped coil in which a plurality of spiral pattern coils are sandwiched with an insulating material, and is formed into a substantially C shape, and is formed on the outer peripheral surface of the holding body 12. It is fixed. Of course, a conventional winding coil may be molded to have the same configuration. The pattern coil comprises a focus drive coil and a tracking drive coil. The focus drive coil faces the focus drive magnet 22. The tracking drive coil faces the tracking drive magnet 24.

In the pickup device of the embodiment configured as described above, since the opening 101 for inserting the optical element formed in the optical element block 100 is covered with the flexible substrate 130, the opening is opened. It is not necessary to cover 101 with a separate cover or the like. Alternatively, the optical element block 100 can be integrated with the base plate because it is not necessary to press the opening 101 against the base plate of the device body when it is assembled to the device body.

In addition, various design items can be changed without departing from the scope of the present invention. For example, the flexible substrate 130 may be attached to the optical element block by using an adhesive instead of the attachment by the above-described attachment, or together with the attachment. Accordingly, the flexible substrate 130 can be brought into close contact with the opening 101 in combination with the flexibility of the flexible substrate 130, so that the airtightness can be further enhanced. In addition, since this adhesive absorbs dust that has once entered the optical element block 100, there is an advantage that the influence of dust can be minimized.

[0028]

[Effect of device]

 In the present invention, since the opening for inserting the optical element is covered with the flexible substrate, it is not necessary to use a dedicated cover or press the opening against the base plate as in the conventional case. Therefore, it is possible to surely close the opening without increasing the number of parts.

[Brief description of drawings]

FIG. 1 is a plan view of an optical element block and a flexible substrate which constitute an optical pickup device according to an embodiment of the present invention.

FIG. 2 is a plan view showing a state in which a flexible substrate is attached to the optical element block.

FIG. 3 is a sectional view of a main part of the above optical element block.

FIG. 4 is a plan view of a main part of the optical element block.

FIG. 5 is another cross-sectional view of the main part of the above optical element block.

FIG. 6 is a plan view of a frame portion that constitutes the optical element block.

FIG. 7 is a cross-sectional view of a frame portion forming the above optical element block.

[Explanation of symbols]

 16 Objective Lens 46 Light Source 50 Half Mirror 56 Light-Receiving Element 100 Optical Element Block 101 Opening 130 Flexible Board

Claims (3)

[Scope of utility model registration request] 1. An optical pickup device in which light from a light source is applied to a recording medium by an objective lens and reflected light from the recording medium is detected by a light receiving element, wherein the light source, the recording medium, and the light receiving element are provided. 2. An optical pickup device characterized in that an opening for inserting an optical element constituting the optical system of (1) is covered with a flexible substrate. 2. The optical pickup device according to claim 1, wherein the optical element is a half mirror, and the flexible substrate is a flexible substrate for supplying power to the light source or the light receiving element. 3. The optical pickup device according to claim 1, wherein the light source, the optical element, the objective lens, and the light receiving element are provided in a block.