JP3778799B2 - Optical pickup device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical pickup device that is incorporated in a CD player or the like and relates to a method of supporting a light receiving element that receives a laser beam.
[0002]
[Prior art]
As an example of the optical pickup device, as disclosed in Japanese Patent Laid-Open No. 8-329511, the light receiving element is provided with connection terminals on the left and right sides and provided with a connection terminal formed in an L shape toward the light receiving surface. A large printed circuit board is soldered so that the light receiving surface faces the printed circuit board, and a hole is provided in the center of the printed circuit board for the reflected light from the recording medium to pass through and irradiate the light receiving element. The printed circuit board and the frame are in contact with each other and filled with an adhesive so as to be supported.
[0003]
As another method, a light receiving element in which a plurality of connection terminals are arranged on the left and right are provided with connection terminals formed in an L shape in the direction of the light receiving surface, and a printed circuit board having an area similar to that of the light receiving element is provided. The connection terminal is soldered so as to face the light receiving surface, and the printed circuit board has a hole through which reflected light from the recording medium passes and irradiates the light receiving element at the center, and positioning concave portions at both ends, and the body frame Is provided with two positioning projections that abut both side surfaces of the light receiving element, the printed circuit board is opposed to the concave portion with the light receiving surface facing the frame direction, and the protrusion and the upper surface of the light receiving element are UV-bonded by an adhesive. It is configured to be supported by an adhesive.
[0004]
As another method, the printed circuit board on which the light receiving element is mounted is provided with a space so that the light receiving element is disposed in the center, and the light receiving element having the connection terminals on the left and right is disposed in the space of the printed circuit board. In addition, the printed circuit board and the connection terminal of the light receiving element are supported by soldering, and the printed circuit board on which the light receiving element is mounted is provided with a hole through which reflected light from the recording medium passes and irradiates the light receiving element. The printed circuit board is fixed with a screw so that the light receiving element matches the hole through which the reflected light from the recording medium provided in the plate passes.
[0005]
[Problems to be solved by the invention]
When the light receiving element is operated, heat is generated, and the power conversion circuit of the light receiving element changes in resistance value due to temperature. This is a change in the converted voltage level in response to a change in temperature. This change also occurs due to the ambient temperature and heat generation of the light receiving element itself, and self-heating causes a change in voltage level when the power supply voltage of the light receiving element is turned on and when time elapses.
[0006]
In drives that use an optical pickup, this voltage level is automatically adjusted appropriately by various circuits when the power is turned on or when the disk is replaced. If this is set when the power is turned on, the level adjusted over time is appropriate. The case where it deviates from a certain value is considered. When the adjusted level deviates from the appropriate value, the reproduction and recording performance of the disc deteriorates, and in the worst case, the recording damage of the CD-R disc occurs.
[0007]
The present invention is intended to provide an optical pickup device that solves such problems.
[0008]
[Means for Solving the Problems]
The optical pickup device according to the present invention is provided with a plate having excellent heat conductivity and heat dissipation attached to a housing in which various optical components are assembled, and a recess in which a light receiving element is loosely fitted is provided on the plate. A hole through which the reflected light passes and an adhesive hole are provided, and the adhesive filled in the adhesive hole in a state of loosely fitting so that the hole through which the reflected light passes in the concave portion and the detection part of the light receiving element are aligned. The light receiving element is adhered and adhered to the plate.
[0009]
【Example】
FIG. 1 is an exploded perspective view showing a main part of an optical pickup device according to an embodiment of the present invention. 2 is a cross-sectional view taken along the line AA ′ showing a state in which the light receiving element is bonded and fixed to the frame shown in FIG.
[0010]
In FIG. 1, reference numeral 1 denotes a housing in which various optical components of the pickup device are incorporated, 1 a denotes a housing through hole through which reflected light from a recording medium provided in the housing 1 passes, and 2 denotes a light receiving portion in the direction of the housing 1. Is a light receiving element provided with a plurality of terminals, the detection portion 2a provided on the light receiving surface is provided at a position shifted from the center, and a flexible printed circuit board 3 is provided on the rear surface of the light receiving element 2. Glued and connected.
[0011]
4 is a plate made of aluminum excellent in heat conductivity and heat dissipation to which the light receiving element 2 is mounted, 4a is a mounting recess for loosely mounting the light receiving surface of the light receiving element 2 on the plate 4, and 4b is the mounting recess. 4a is provided with a hole at a position that coincides with the housing hole 1a, and a plate through-hole 4c is provided at a position that coincides with the detection portion 2a of the light receiving element 2 and a hole is provided at the center of the mounting recess 4a. , An adhesion hole for adhering the hole and the light receiving surface of the light receiving element 2.
[0012]
Reference numeral 5 denotes a plate base made of aluminum which is disposed between the plate 4 and the housing 1 and holds the plate 4 and has excellent heat conductivity and heat dissipation . 5a denotes a plate through hole 4b and a housing through hole in the plate base 5. A plate base through hole 6 provided at a position coinciding with the hole 1 a is an iron cover that presses the flexible printed circuit board 3 and the light receiving element 2 and attaches to the plate base 5.
[0013]
7a and 7b are provided in the plate base 5 and screw holes for attaching the plate 4 and the cover 6 to which the light receiving element 2 is attached, and 8a and 8b are positions where the plate through hole 4b and the plate base through hole 5a coincide. The plate mounting holes 9a and 9b are provided with holes corresponding to the screw holes 7a and 7b, and cover mounting holes to which the cover 6 is mounted.
[0014]
10a denotes a mounting screw that is attached to the screw hole 7a via the cover attachment hole 9a and the plate attachment hole 8a, and 10b denotes a screw hole that attaches to the screw hole 7b via the cover attachment hole 9b and the plate attachment hole 8b in the same manner as the attachment screw 10a. , 11a and 11b are plate base mounting screw holes which are provided on the same surface as the housing through hole 1a of the housing 1 and to which the plate base 5 is mounted.
[0015]
Reference numerals 12a and 12b denote plate base mounting holes for mounting the plate base 5 in contact with the housing 1, and are screwed to the plate base mounting screw holes 11a and 12b by plate mounting screws 13a and 14b. The plate base mounting holes 12a and 12b are free from play with the diameters of the plate mounting screws 13a and 13b when the plate base 5 is mounted, so that the reflected light from the recording medium is accurately reflected on the light receiving element 2. It is configured to be adjusted and screwed to receive light.
[0016]
14 is a Z-axis adjustment hole for adjusting the plate base 5 in the Z-axis direction, 16 is screwed into the Z-axis adjustment hole 14, and the tip of the screw presses against the contact surface 16 of the housing 1. The base 5 is configured to be displaced in the Z-axis direction so that the light receiving element 2 accurately receives the reflected light from the recording medium.
[0017]
Next, the assembly method will be described. First, the light receiving surface of the light receiving element 2 in which the flexible printed circuit board 3 is bonded and connected to the mounting recess 4a provided in the plate 4 is connected to the detection portion 2a of the light receiving element 2 and the plate through hole 4b. Match and loose fit. The light receiving element 2 and the plate 4 are bonded together by loosely fitting and holding the close contact state, and filling the bonding hole 4c with UV bonding, that is, filling with an adhesive and curing.
[0018]
The plate 4 on which the light receiving element 2 is mounted holds a state in which the cover 6 is pressed from the back of the light receiving element 2 to which the flexible printed circuit board 3 is bonded, and is attached via the cover mounting hole 9a and the plate mounting hole 8a by the mounting screw 10a. Screwed into the screw hole 7a. Similarly, the mounting screw 10b is screwed to the screw hole 7b through the cover mounting hole 9b and the plate mounting hole 8b. In the state in which the plate base 5 to which the components are attached in this manner further aligns the housing through hole 1a and the plate base translucent light 5a, the plate mounting screws 13a and 14b are connected to the plate base mounting screws 12a and 12b. It is attached to the holes 11a and 12b.
[0019]
Next, when the Z-axis adjusting screw 15 is screwed through the Z-axis adjusting hole 14 and the contact surface 16 is pressed, the plate base 5 is urged in the Z-axis direction, and the light receiving element 2 receives reflected light from the recording medium. The Z-axis adjusting screw 15 is adjusted so that the optical axis accurately irradiates the light receiving element 2.
[0020]
As a result, the reflected light from the recording medium is irradiated from the housing through hole 1a through the plate base through hole 5a and the plate through hole 4b to the detection unit 2a of the light receiving element 2.
[0021]
【The invention's effect】
The present invention adheres a light receiving element to a plate by filling an adhesive into a bonding hole of the plate in a state where a light receiving surface of the light receiving element is in close contact with a recess provided in a plate having excellent thermal conductivity and heat dissipation. Thus, the assembling work for adhering the light receiving element to the plate is simplified, and the heat generated by the light receiving element can be effectively transmitted to the plate and dissipated.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing a main part of an optical pickup device showing an embodiment of the present invention.
2 is a cross-sectional view taken along the line AA ′ in a state where a light receiving element is bonded and fixed to the frame shown in FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Housing 2 Light receiving element 2a Detection part 4 Plate 4a Mounting recessed part 4b Plate through-hole 4c Bonding hole 5 Plate base

Claims (1)

The laser beam emitted from the laser element is irradiated on a recording medium by converging by the objective lens, an optical pickup device that received by the light receiving element the reflected light from the recording medium, the heat in a housing that various optical components are incorporated A plate having excellent conductivity and heat dissipation is attached, and a concave portion in which the light receiving element is loosely fitted is provided in the plate , and a hole and an adhesive hole through which the reflected light passes are provided in the concave portion, and the reflected light in the concave portion is provided. An optical pickup device characterized in that a light receiving element is adhered and adhered to the plate with an adhesive filling the adhesive hole in a state in which the hole through which the light passes and the detection portion of the light receiving element are loosely fitted. .

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