JP2005190581A - Optical pickup device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical pickup device capable of radiating heat generated from a drive IC efficiently. <P>SOLUTION: An optical pickup device 1 is constituted so that an optical disk is irradiated with a laser beam and a reflected light from the optical disk is received. The optical pickup device 1 is equipped with: light emitting elements each of which emits a laser beam; a driver IC 51 which drives the light emitting elements; a housing in which the light emitting elements and the driver IC 51 are installed; and a cooling means 6 comprising pump 61 which circulates coolant, an endothermic part 62 which absorbs heat and a heat dissipation part 63 which radiates heat absorbed by the endothermic part 62, wherein the coolant 66 absorbs heat generated from the driver IC 51 through the endothermic part 62 while the pump 61 circulates the coolant 66 between the endothermic part 62 and the head dissipation part 63 and the absorbed heat is discharged through the heat dissipation part 63 by the cooling means 6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical pickup device.

  In recent optical pickup devices, the reading speed and writing speed of information from an optical disk tend to increase. In such an optical pickup device, the heat generation of the component parts during the operation is remarkable, so how to realize the cooling is an important issue. Here, examples of components that generate significant heat include a light-emitting element that irradiates an optical system with laser light, and a driver IC that drives the light-emitting element.

  Regarding this problem, a technique described in Patent Document 1 is disclosed in a conventional optical pickup device. In this optical pickup device, a heat conductive member is installed on the upper surface (top surface) of the driver IC, and the driver IC and the shield case are brought into contact with each other so as to be able to transfer heat. As a result, when the driver IC generates heat when the optical pickup device is in operation, the heat is transmitted to the shield case via the heat conductive member, and is released from the shield case to the outside air. Can be cooled.

  However, the optical pickup device as described above has a problem in that the heat dissipation effect depends on the shape of the housing and the like, so that the heat dissipation efficiency is low and the driver IC is not sufficiently cooled.

JP-A-11-185273

  An object of the present invention is to provide an optical pickup device that can efficiently dissipate heat generated from a driver IC.

Such an object is achieved by the present inventions (1) to (3) below.
(1) An optical pickup device that irradiates an optical disc with laser light and receives reflected light from the optical disc,
A light emitting element for emitting the laser beam;
A driver IC for driving the light emitting element;
A housing in which the light emitting element and the driver IC are installed;
A cooling unit having a pump that circulates the refrigerant, a heat absorbing part that absorbs heat, and a heat radiating part that releases heat absorbed by the heat absorbing part,
The cooling means absorbs the heat generated from the driver IC through the heat absorbing portion while the pump circulates the refrigerant between the heat absorbing portion and the heat radiating portion. An optical pickup device, wherein absorbed heat is released through the heat radiating portion.

  (2) The optical pickup device according to (1), further including an air cooling fan that air-cools the heat radiating unit.

  (3) The optical pickup device according to (1) or (2), wherein the heat radiating unit is installed outside the housing.

  According to the present invention, since the refrigerant circulates around the driver IC, the heat generated from the driver IC can be efficiently radiated.

  The optical pickup device of the present invention will be described below in detail based on preferred embodiments shown in the accompanying drawings.

<First Embodiment>
FIG. 1 is a perspective view showing a first embodiment of an optical pickup device of the present invention.

  The optical pickup device 1 has a function of reading information recorded on the optical disc 100 by irradiating the optical disc 100 with laser light L1 and receiving reflected light L2. The optical pickup device 1 is installed in, for example, an optical disc drive (not shown) and is driven by a drive mechanism (not shown) of the optical disc drive to slide and displace its position relative to the optical disc 100.

  The optical pickup device 1 is applied to, for example, an optical disc drive mounted on a computer (personal computer), video equipment, audio equipment, or other electronic equipment, and in particular, an optical disc drive capable of reading a plurality of types of optical discs 100. Applied. Examples of the optical disc 100 include a CD (compact disc) and a DVD (digital video disk).

  As shown in FIG. 1, the optical pickup device 1 includes a housing 2, a base 3, an optical system 4, and a drive circuit 5.

  A housing 2 shown in FIG. 1 has a frame shape corresponding to the inside of the optical pickup device 1, and a base 3, an optical system 4, and a drive circuit 5 are accommodated (installed) in the frame. The optical pickup device 1 is supported by a drive mechanism of an optical disc drive through the housing 2, and is driven by the drive mechanism when the optical pickup device 1 is operating, so that the position relative to the optical disc 100 is slid.

  The base 3 shown in FIG. 1 is made of, for example, a metal plate-like member, and is fixed (installed) to the housing 2. In addition, although it does not specifically limit as a metal material, For example, various metals, such as iron, nickel, stainless steel, copper, brass, aluminum, titanium, or an alloy containing these are used.

  The optical system 4 shown in FIG. 1 includes a first light emitting element 41a, a second light emitting element 41b, a dichroic prism 43, a collimator lens 44, a reflecting mirror 45, a sensor lens 42, and a photodiode (light receiving element) 46. And a coupling lens 48 and a grating 49.

  Here, the first light emitting element 41 a and the second light emitting element 41 b are semiconductor laser diodes, and are fixed (installed) on the base 3. The first light emitting element 41a and the second light emitting element 41b are separately configured as semiconductor laser diodes for CD and DVD, for example, and oscillate laser beams L1 having different wavelengths. And this optical pick-up apparatus 1 can read information from two types of optical disks 100 of CD and DVD by using each light emitting element 41a, 41b properly.

  The drive circuit 5 shown in FIG. 1 includes a driver IC 51, a circuit board 52, and a shield case 54, and has a function of driving the first light emitting element 41a and the second light emitting element 41b of the optical system 4.

  The driver IC 51 is fixed (provided) so that the bottom surface thereof is in contact with the base 3. The fixing method is not particularly limited, but can be fixed by, for example, welding such as brazing, adhesion with an adhesive, or the like.

  The circuit board 52 is a resin-made flexible board, is disposed in the vicinity of the driver IC 51, and is fixed (attached) to the base 3 by thermocompression bonding. On the circuit board 52, a circuit pattern relating to an electric signal input to the driver IC 51 is printed. The driver IC 51 and the circuit board 52 are electrically connected by a lead wire (bonding wire) 53.

  The shield case 54 is made of brass or other shielding material that can block unwanted radiation, and is installed on the base 3 so as to cover the driver IC 51. The shield case 54 blocks unnecessary radiation from the inside of the driver IC 51 and suppresses malfunction of peripheral devices due to the influence of unnecessary radiation.

  In the optical pickup device 1, first, the first light emitting element 41a is driven by the drive circuit 5 to oscillate the laser light L1. The laser light L 1 is collected by the coupling lens 48, diffracted by the grating 49, and enters the dichroic prism 43. The laser light L 1 is refracted by the dichroic prism 43 and travels toward the collimator lens 44. The laser light L1 becomes parallel light by the collimator lens 44, is reflected by the reflecting mirror 45, and enters (irradiates) a recording layer (not shown) of the optical disc 100.

  Next, the reflected light L2 reflected by the optical disc 100 (recording layer) is reflected by the reflecting mirror 45 and becomes parallel light by the collimator lens 44 and enters the dichroic prism 43, contrary to the above. The reflected light L 2 is refracted by the dichroic prism 43, passes through the sensor lens 42, and enters the photodiode 46. The reflected light L2 is received by the photodiode 46 and detected as an optical signal. Based on this optical signal, information stored in the optical disc 100 is acquired and reproduced.

  The optical pickup device 1 can read information from two types of optical discs 100 by using the first light emitting element 41a and the second light emitting element 41b properly. Specifically, when the optical disc 100 is a CD, the first light emitting element 41a is used, and when the optical disc 100 is a DVD, the second light emitting element 41b is used. In the operation of the optical pickup device 1 described above, the case of the first light emitting element 41a has been described. However, since the operation of the second light emitting element 41b is almost the same as that of the first light emitting element 41a, the description thereof is omitted. Omitted.

  2 and 3 are an enlarged view (FIG. 2) and a block diagram (FIG. 3) showing a cooling means for the driver IC shown in FIG. The cooling means 6 for the driver IC 51 includes a pump 61, a heat absorbing unit 62, a heat radiating unit 63, a pipe 64, and an air cooling fan 65. The driver IC 51 generates heat when the optical pickup device 1 is in operation. It has a function of cooling.

  As shown in FIG. 2, the pump 61 has a function of circulating the refrigerant 66 between the heat absorbing portion 62 and the heat radiating portion 63 via the pipe 64, and is on the base 3 and outside the shield case 54. Is installed. As this pump 61, a small pump according to the size of the housing 2 of the optical pickup device 1 is employed. The refrigerant 66 is not particularly limited, and examples thereof include an antifreeze liquid such as an ethylene glycol liquid and a propylene glycol liquid.

  The heat absorption part 62 is configured by a bellows-like tubular member made of metal or other thermally conductive material, and is disposed in contact with the driver IC 51 so as to cover the upper surface of the driver IC 51. The heat absorbing portion 62 is supplied with the refrigerant 66 from the pump 61 via the pipe line 64, and absorbs heat generated by the driver IC 51 using the refrigerant 66. In addition, the shape of the heat radiating part 63 is not limited to the bellows shape, and may be a spiral shape, for example.

  The heat dissipating part (radiator) 63 is composed of a member made of a metal or other heat conductive material, is installed on the base 3 and outside the shield case 54, and is modularized together with the pump 61.

  The heat radiating part 63 is disposed between the heat absorbing part 62 and the pump 61 (see FIG. 3), and cools the refrigerant 66 passing through the inside by releasing heat from the heat radiating surface (outer surface) 631 to the air. To do. Further, the heat radiating portion 63 is installed with its heat radiating surface 631 in contact with the surface of the base 3. Thereby, the heat conduction by the contact from the heat radiation part 63 to the base 3 becomes possible.

  The air cooling fan 65 is installed above the heat radiating surface 631 of the heat radiating portion 63. The air cooling fan 65 circulates the air around the heat radiating portion 63 by its rotation, assists the release of heat from the heat radiating portion 63 (air cooling), and promotes cooling of the refrigerant 66 in the heat radiating portion 63.

  As shown in FIG. 2, in the optical pickup device 1, the driver IC 51 generates heat during operation. On the other hand, in the cooling unit 6, first, the pump 61 circulates the refrigerant 66 between the heat absorbing unit 62 and the heat radiating unit 63 through the pipe 64 by driving. Next, the heat absorption part 62 performs heat exchange with the driver IC 51 using the refrigerant 66 and absorbs heat from the driver IC 51. As a result, the driver IC 51 is cooled. Next, the heat radiating unit 63 releases heat from the refrigerant 66 to cool the refrigerant 66. At this time, the air cooling fan 65 assists the heat radiation from the refrigerant 66 and cools the refrigerant 66 efficiently. Thereby, the cooling efficiency of the driver IC 51 is synergistically increased.

  Further, in this optical pickup device 1, since the base 3 is made of a metallic material having a good thermal conductivity as described above, the heat conduction from the heat radiating portion 63 to the base 3 is favorably performed. Thereby, the cooling efficiency of the driver IC 51 is further enhanced. The heat transmitted to the base 3 is released from the back side of the base 3 to the outside of the optical pickup device 1. The cooled refrigerant 66 is sent from the heat radiating unit 63 to the pump 61 and supplied to the heat absorbing unit 62 again.

  According to the optical pickup device 1, compared with the conventional optical pickup device, since the heat radiation from the driver IC 51 is positively performed by the cooling means 6, there is an advantage that the driver IC 51 can be efficiently cooled. In particular, the cooling means 6 includes an air cooling fan 65, and the air cooling fan 65 promotes heat radiation from the refrigerant 66. Therefore, there is an advantage that the cooling of the driver IC 51 is synergistically improved. In addition, since the air cooling fan 65 radiates heat from the refrigerant 66 without depending on the shape, heat capacity, etc. of the housing 2, the driver IC 51 can be efficiently cooled compared to the conventional optical pickup device. There is.

  In the optical pickup device 1, water is used as the refrigerant 66 of the cooling means 6. This is preferable in that the cooling means 6 can be configured with a simple material at low cost. However, the present invention is not limited to this, and any refrigerant may be selected and employed as the refrigerant 66 within a range obvious to those skilled in the art. The refrigerant 66 is preferably one that does not corrode the components 61 to 64 of the cooling means 6.

  Further, in this optical pickup device 1, the pipe line 64 of the cooling means 6 is constituted by a metal pipe. Such a configuration is preferable in that heat dissipation from the pipe 64 to the air is promoted between the pump 61 and the heat absorbing portion 62, and thus the cooling efficiency of the driver IC 51 can be increased synergistically. However, the present invention is not limited to this, and the pipe 64 may be made of resin or any other material.

  Further, in this optical pickup device 1, the pump 61 and the heat radiating portion 63 of the cooling means 6 are disposed outside the housing 2 by extending the pipe 64, and the heat radiated from the heat radiating portion 63 outside the housing 2. It is characterized in that is performed.

Second Embodiment
FIG. 4 is a perspective view showing another configuration example of the cooling means for the driver IC shown in FIG.

  Hereinafter, the second embodiment of the optical pickup device of the present invention will be described with reference to this figure. However, the difference from the above-described embodiment will be mainly described, and the description of the same matters will be omitted.

  In the present embodiment, the cooling means 6 for the driver IC 51 is the same as the first embodiment except that some of the components are arranged outside the housing 2 of the optical pickup device 1.

  As described above, the optical pickup device 1 is incorporated into an optical disk drive (not shown) and constitutes a part thereof. The optical pickup device 1 is supported by a drive mechanism (not shown) of an optical disk drive, and slides to displace the position relative to the optical disk 100 by driving the drive mechanism. The optical pickup device 1 is connected to a drive substrate 72 via a flexible substrate 71 (see FIG. 4). The drive board 72 is installed outside the housing 2 and controls the drive of the drive mechanism of the optical disk drive. The flexible substrate 71 has a flexible structure (flexibility) that can follow the displacement when the optical pickup device 1 is slid and displaced by driving.

  Here, in this embodiment, the pump 61, the heat radiation part 63, and the air cooling fan 65 which comprise the cooling means 6 are installed on the drive board 72 outside the housing | casing 2 (refer FIG. 4). The pump 61 and the heat radiating part 63 are connected to the heat absorbing part 62 on the driver IC 51 through an extended pipe line 64. The pipe 64 is made of a bendable resin material or other flexible material, and is integrally bonded onto the flexible substrate 71. Then, the duct 64 bends integrally when the flexible substrate 71 is deformed, and flexibly follows the deformation. Thus, the pipe line 64 is installed so as not to hinder the slide displacement of the optical pickup device 1 (the arrow direction in FIG. 4).

  In the present embodiment, the refrigerant 66 that has absorbed heat from the driver IC 51 is conveyed to the drive board 72 outside the housing 2 through the pipe 64, where it is radiated and cooled by the function of the heat radiating unit 63. Then, the cooled refrigerant 66 is sent again to the heat absorption unit 62 on the driver IC 51 through the pipe 64 to cool the driver IC 51.

  According to the configuration as described above, the heat absorbed from the driver IC 51 is released outside the housing 2, so that the situation in which the inside of the housing 2 becomes a high temperature due to heat radiation from the heat radiating unit 63 is suppressed. There is. In particular, when the optical pickup device 1 is in operation, the housing 2 and the inside thereof become high temperature due to heat generated by the components (the driver IC 51, the first light emitting element 41a, and the second light emitting element 41b). For this reason, there is a possibility that the driver IC 51 may not be sufficiently cooled by heat radiation to the air in the housing 2 or heat conduction to the housing 2. In this respect, in the optical pickup device 1, since the heat absorbed from the driver IC 51 is radiated outside the housing 2, the cooling efficiency is extremely high. Further, in such a configuration, since a part of the cooling means 6 is installed outside the housing 2, there is an advantage that space saving in the housing 2 can be realized.

  The optical pickup device of the present invention has been described above with reference to the illustrated embodiment. However, the present invention is not limited to this, and each component constituting the optical pickup device can have any configuration that can exhibit the same function. Can be substituted. Moreover, arbitrary components may be added.

It is a perspective view which shows the optical pick-up apparatus of this invention. It is an enlarged view which shows the cooling means with respect to the driver IC shown in FIG. It is a block diagram which shows the cooling means with respect to the driver IC shown in FIG. It is a perspective view which shows the other structural example of the cooling means with respect to the driver IC shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical pick-up apparatus 2 Case 3 Base 4 Optical system 41a 1st light emitting element 41b 2nd light emitting element 42 Sensor lens 43 Dichroic prism 44 Collimator lens 45 Reflector 46 Photodiode 48 Coupling lens 49 Grating 5 Drive circuit 51 Driver IC
52 Circuit board 53 Lead wire 54 Shield case 6 Cooling means 61 Pump 62 Heat absorption part 63 Heat radiation part 631 Heat radiation surface 64 Pipe line 65 Air cooling fan 66 Refrigerant 71 Flexible board 72 Drive board 100 Optical disk L1 Laser light L2 Reflected light

Claims (3)

An optical pickup device that irradiates an optical disc with laser light and receives reflected light from the optical disc,
A light emitting element for emitting the laser beam;
A driver IC for driving the light emitting element;
A housing in which the light emitting element and the driver IC are installed;
A cooling unit having a pump that circulates the refrigerant, a heat absorbing part that absorbs heat, and a heat radiating part that releases heat absorbed by the heat absorbing part,
The cooling means absorbs the heat generated from the driver IC through the heat absorbing portion while the pump circulates the refrigerant between the heat absorbing portion and the heat radiating portion. An optical pickup device, wherein absorbed heat is released through the heat radiating portion.   The optical pickup device according to claim 1, further comprising an air cooling fan that air-cools the heat dissipating unit.   The optical pickup device according to claim 1, wherein the heat radiating unit is installed outside the housing.

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