JP3650002B2 - Optical disk recording or playback device - Google Patents

Description

[0001]
[Field of the Invention]
The present invention relates to an optical disk recording or reproducing apparatus (hereinafter referred to as “recording / reproducing apparatus”) for recording and reproducing information by irradiating a laser on an optical disk.
[0002]
[Prior art]
As shown in FIGS. 4 and 5, the optical pickup (1) of the recording / reproducing apparatus includes a laser light emitting part (12) on a main body part (11) and an objective lens for condensing the light from the laser light emitting part (12). (14) A sensor (13) that detects the light modulated by reflecting the condensed light beam by the disk (9), converts it into an electrical signal and outputs it, and controls the laser power to be substantially constant. The circuit board (2) to be protruded from the side surface of the main body (11) is provided.
The circuit board (2) is surrounded by a radiator (40) fixed to the main body (11).
A mounting piece (16) projects from the main body (11) below the circuit board (2), and a light shielding plate (50) is fastened to the mounting piece (16) by screws (51).
The optical pickup (1) is guided by guide shafts (6) and (61) and moves in the radial direction of the disc in a plane parallel to the disc (9) to record or reproduce information.
[0003]
The recording / reproducing apparatus irradiates the disk (9) with laser from the optical pickup (1), but the laser power is slightly different for each disk to be used. Must be set to power. The data is called control data and is recorded at a position close to the outer periphery of the disk. Also, security data that records that the disc to be used is a product based on a regular standard is also recorded at a position near the outer periphery of the disc.
[0004]
Since the recording / reproducing apparatus needs to reproduce the control data and the security data before reading / writing information, the optical pickup (1) must be moved to the vicinity of the outermost periphery of the disk. In order to move it accurately, it is necessary to detect the position of the optical pickup (1).
For this purpose, the light-shielding plate (50) is provided. When the light-shielding plate (50) shields light from the infrared sensor (8) provided on the mechanism of the recording / reproducing apparatus, the optical pickup (1) It is determined that it is not located on the outermost periphery of the disk (9) and is located on the outermost periphery without being shielded from light.
[0005]
On the other hand, the optical pickup (1) is controlled by the circuit board (2) so that the laser power becomes substantially constant as described above. However, in the circuit board (2), a change (power drift) occurs in the laser power due to a change in ambient temperature, and as a result, the reproduction signal is deteriorated.
[0006]
An example of the heat generation source is the circuit board (2) itself. This is because the auto power control integrated circuit (APC IC) of the circuit board (2) generates heat during driving.
Therefore, the circuit board (2) is surrounded by the heat radiating body (40) to dissipate heat generated by the circuit board (2).
The radiator (40) is formed in a U-shaped cross section at the bottom wall (41), the side wall (42) and the ceiling wall (43), and between the bottom wall (41) and the ceiling wall (43) (7) The circuit board (2) is sandwiched via (7) and the mounting protrusion (47) provided on the ceiling wall (43) is superimposed on the upper surface of the main body (11) and fixed with screws (48). .
[0007]
The heat dissipating sheet (7) transmits the heat generated in the circuit board (2) to the heat dissipating body (40) and dissipates the bottom wall (41) and ceiling wall (43) of the heat dissipating body (40) as much as possible. It is arranged to be close to the circuit board (2) and prevent short circuit between the radiator (40) and the circuit board (2), and before the radiator (40) is put on the circuit board (2). The heat sink (40) is attached to the inner surface of the bottom wall (41) and the ceiling wall (43).
[0008]
[Problems to be solved by the invention]
The radiator (40) transmits heat to the main body (11) through the mounting protrusion (47) and dissipates heat from the main body (11), but the mounting protrusion (47) and the main body (11) Therefore, the main body (11) does not function effectively as a heat radiating member.
[0009]
The heat radiating sheet (7) is generally a gel-like insulating silicone sheet, and since the sheet (7) does not slide smoothly with the circuit board (2), the heat radiating body (40) has a bottom wall (41). ) And the ceiling wall (43), the opening height on the free end side is slightly larger than the normal dimension, and when the radiator (40) is put on the circuit board (2), the heat dissipation sheet (7) And the circuit board (2) are prevented from contacting each other.
After placing the radiator (40) on the circuit board (2), correct the bending of the radiator (40) so that the bottom wall (41) of the radiator (40) and the free end of the ceiling wall (43) are closed. To do.
However, due to the elasticity of the heat dissipating body (40), the opening portion returns to the opening direction. As a result, the adhesion between the circuit board (2) and the heat dissipating sheet (7) is deteriorated and the heat dissipating effect is lowered.
[0010]
The present invention provides a recording / reproducing apparatus including an optical pickup that can solve the above-described problems.
[0011]
[Means for solving the problems]
In the recording / reproducing apparatus of the present invention, a circuit board (2), a radiator (4), and a light shielding plate (5) are attached so as to protrude from the main body (11) of the optical pickup (1). ) Functions so that the power of the laser beam emitted from the laser emitting section (12) becomes substantially constant, and the heat radiating body (4) surrounds the circuit board (2) and releases heat generated from the board. The light shielding plate (5) functions to detect that the optical pickup (1) is not at a position corresponding to the outermost periphery of the disk by shielding light from the infrared sensor (8) provided in the apparatus. The heat radiator (4) and the light shielding plate (5) are integrally formed.
[0012]
Specifically, a heat radiating body (4) and a light shielding plate (5) are formed by bending one metal plate, and the heat radiating body (4) surrounds the circuit board (2) and forms a bottom wall (41). The ceiling wall (43) and the left and right side walls (42) and (44) are provided, and the bottom wall (41) is connected to the light shielding plate (5).
[0013]
More specifically, the light shielding plate (5) is integrally continuous with the bottom wall (41), the one side wall (42), the ceiling wall (43), and the other side wall (44) of the radiator (4). The lower end of the other side wall (44) is located above the light shielding plate (5) and floats from the light shielding plate (5) so that the space height between the bottom wall (41) and the ceiling wall (43) is the side wall ( 44) is formed so that the side is larger than the normal dimension, the lower end of the side wall (44) floating from the light shielding plate (5) is corrected and joined in contact with the light shielding plate (5), the circuit board (2) and the ceiling A heat radiation sheet (7) (7) is interposed between the wall (43) and between the circuit board (2) and the bottom wall (41).
[0014]
[Action and effect]
Since the heat radiating body (4) surrounding the circuit board (2) is formed integrally with the light shielding plate (5), the heat generated by the circuit board (2) is not only the heat radiating body (4) but also the light shielding plate (5). Also, the temperature rise of the circuit board (2) can be effectively suppressed, and the power drift can be reduced.
[0015]
A light shielding plate (5) and a heat radiating body (4) can be formed by bending a single metal plate, which is easy to manufacture and can reduce costs.
[0016]
The bottom wall (41) of the radiator (4), one side wall (42), the ceiling wall (43) and the other side wall (44) are connected from the light shielding plate (5) to the lower end of the other side wall (44). Is floated above the shading plate (5) above the shading plate (5), and the height of the space between the bottom wall (41) and the ceiling wall (43) is such that the side wall (44) side is larger than the normal dimension. If formed, the heat-dissipating sheets (7) and (7) are bonded to the inner surfaces of the bottom wall (41) and the ceiling wall (43), and then the bottom wall (41), the ceiling wall (43) and both side walls (42) ( 44) When the heat sink (4) is placed on the circuit board (2) so that the circuit board (2) fits between the circuit board (2), the contact between the heat radiating sheet (7), (7) and the circuit board (2) which is not slippery Can be prevented and workability is good.
[0017]
After covering the circuit board (2) with the radiator (4), the side wall (44) floating from the light shielding plate (5) is corrected and applied to the light shielding plate (5) and soldered (46). If the heat radiating sheets (7) and (7) arranged between the board (2) and the bottom wall (61) and between the circuit board (2) and the ceiling wall (63) are sandwiched, the heat radiating sheet (7) The sandwiched state of (7) is maintained, and the heat dissipation effect does not decrease.
[0018]
Embodiment
1 to 3, the same components as those in FIGS. 4 and 5 shown in the conventional example are denoted by the same reference numerals, and the description thereof is omitted.
The present invention is different from the conventional example in that a radiator (4) surrounding the circuit board (2) is integrally formed on a light shielding plate (5) protruding from the lower surface of the aluminum die-cast main body (11). It is a point formed.
[0019]
The light shielding plate (5) and the radiator (4) are formed by punching and bending a metal plate having a thickness of about 0.3 mm.
The light-shielding plate (5) has a substantially rectangular shape, and has a reinforcing rib (52) facing upward on the tip side of one side edge. A positioning hole (53) and a screw insertion hole (54) are provided at the base end of the light shielding plate (5).
[0020]
The radiator (4) surrounds the circuit board (2) protruding from the side surface of the main body (11) of the optical pickup (1), and includes a bottom wall (41), a ceiling wall (43), and left and right side walls (42). ) (44).
The bottom wall (41) of the radiator (4) extends integrally from the base end side of the side edge of the light shielding plate (5) opposite to the reinforcing rib (52), and the inner side wall (44) , Located above the light shielding plate (5) and slightly separated from the light shielding plate (5).
The outer side wall (42) also serves as a reinforcing rib on the base end side of the radiator (4).
The space height of the bottom wall (41) and the ceiling wall (43) is slightly less than 1mm larger than the total height of the circuit board (2) to prevent short circuit with the radiator (4), but the side wall on the light shielding plate (5) The space height is larger than the normal dimension by the amount that (44) floats from the light shielding plate (5).
A connecting piece (45) is bent outwardly at the lower end of the side wall (44) floating from the light shielding plate (5).
The bottom wall (41) and the ceiling wall (43) are formed in a size that allows the circuit board (2) to be accommodated without protruding, and the heat radiating sheet (7) is formed on the inner surfaces of the bottom wall (41) and the ceiling wall (43). ) (7) is pasted.
[0021]
The heat-dissipating sheets (7) and (7) are commercially available insulating gel-like silicone sheets having a thickness of about 0.5 mm and covered with a protective film (not shown) on the surface and completely covering the circuit board (2). And it is cut into a rectangle slightly smaller than the bottom wall (41) and the ceiling wall (43) of the radiator (4). The protective film is peeled off and bonded to the bottom wall (41) and the ceiling wall (43) of the heat radiating body (4) by the adhesiveness of the heat radiating sheets (7) and (7).
[0022]
However, the heat radiating body (4) is put on the circuit board (5) protruding from the main body (1) from the base end side opening of the light shielding plate (5).
Since the space height of the bottom wall (41) and the ceiling wall (43) is larger than the normal dimension, the radiator (4) has poor slipping attached to the bottom wall (41) and the ceiling wall (43). It is possible to prevent the heat dissipation sheet (7) from hitting the circuit board (2), and the workability is improved.
[0023]
The positioning hole (53) of the light shielding plate (5) is fitted into the protrusion (17) projecting from the lower surface of the main body (11), and the screw (51) is screwed into the main body (11) from the screw insertion hole (54). Then, the light shielding plate (5) is fixed.
The ceiling wall (43) of the radiator (4) is pressed against the light shielding plate (5), the lower end of the side wall (44) is brought into contact with the light shielding plate (5), and the connecting piece (45) is attached to the light shielding plate (5). Solder to (46).
The heat dissipation sheet (7) is sandwiched between the circuit board (2), the bottom wall (41) and the ceiling wall (43).
The side wall (44) soldered (46) to the light shielding plate (5) also serves as a reinforcing rib of the light shielding plate (5).
[0024]
As described above, by integrally forming the heat radiating body (4) on the light shielding plate (5), the heat of the heat radiating body (4) is transmitted to the light shielding plate (5), so that the heat radiation effect is improved and the power drift can be reduced. .
[0025]
Also, by soldering (46) the side wall (44) of the radiator (4) to the light shielding plate (5), the side wall (44) is lifted from the light shielding plate (5) by elastic recovery of the bending of the metal plate. No, the bottom wall (41) and ceiling wall (43) of the radiator (4) can be kept in close contact with the circuit board (2) via the heat radiation sheets (7) and (7), and the heat radiation effect is reduced. Can be prevented.
[0026]
In the above embodiment, since the light shielding plate (5) is simply fixed to the main body (11) with screws (51), the light shielding plate (50) and the radiator (40) are separately provided in the main body (11) as in the prior art. The mounting workability is better than screwing to).
[0027]
Since the side walls (42) and (44) of the heat dissipating body (4) serve as reinforcing ribs on the base end side of the light shielding plate (5), the light shielding plate (5) can be formed with a thin metal plate and is easily bent.
[0028]
In the present invention, the ceiling wall (43) of the radiator (4) can be extended to the main body (11) side, and the ceiling wall can be fixed to the main body (11) with screws. Both (5) and the ceiling wall (43) can be screwed to the main body (11), or the screwing of the light shielding plate (5) can be omitted.
[0029]
Further, the heat radiating body (4) can be integrally formed below the light shielding plate (5), and the light shielding plate (5) can be fixed to the upper surface of the main body (11) with screws (51).
[0030]
The present invention is not limited to the configurations of the above-described embodiments, and various modifications can be made within the scope of the claims.
[Brief description of the drawings]
FIG. 1 is a plan view of an optical pickup device.
FIG. 2 is a sectional view taken along line 1A-A in FIG.
FIG. 3 is a perspective view of a state where a heat sink is disassembled.
FIG. 4 is a plan view of a conventional example.
FIG. 5 is a cross-sectional view taken along line 4B-B.
[Explanation of symbols]
(1) Optical pickup
(11) Main unit
(2) Circuit board
(4) Radiator
(41) Bottom wall
(42) Side wall
(43) Ceiling wall
(44) Side wall
(46) Soldering
(7) Heat dissipation sheet

Claims (3)

A circuit board (2), a heat radiating body (4), and a light shielding plate (5) are attached to the optical pickup (1) so as to protrude from the main body (11). The laser power emitted from the substrate functions so as to be substantially constant, the radiator (4) surrounds the circuit board (2) to release heat from the board, and the light shielding plate (5) is an infrared ray disposed in the apparatus. It functions to detect that the optical pickup (1) is not at the position corresponding to the outermost periphery of the disk by blocking the light from the sensor (8), and the radiator (4) and the light shielding plate (5) are integrated. An optical disc recording or reproducing apparatus, characterized in that The radiator (4) and the light shielding plate (5) are formed by bending one metal plate, and the radiator (4) surrounds the circuit board (2) to surround the bottom wall (41) and the ceiling wall (43 ) And left and right side walls (42), (44), and the bottom wall (41) is continuous to the light shielding plate (5). A part of the light shielding plate (5) is extended to integrally form the bottom wall (41), one side wall (42), the ceiling wall (43) and the other side wall (44) of the radiator (4). The lower end of the other side wall (44) is located above the light shielding plate (5) and floats from the light shielding plate (5), and the height of the space between the bottom wall (41) and the ceiling wall (43) is the side wall (44) side. It is formed so as to be larger than the normal dimension, the lower end of the side wall (44) floating from the light shielding plate (5) is corrected and bonded to the light shielding plate (5), and is joined to the circuit board (2) and the ceiling wall (43). The optical disk recording or reproducing device according to claim 2, wherein a heat radiation sheet (7) (7) is interposed between the circuit board (2) and the bottom wall (41).

Images