WO2014007102A1

WO2014007102A1 - Optical pickup device

Info

Publication number: WO2014007102A1
Application number: PCT/JP2013/067294
Authority: WO
Inventors: 佐藤　実; 加藤　英之; 貴史阿久津; 賢一竹内
Original assignee: 三洋電機株式会社
Priority date: 2012-07-05
Filing date: 2013-06-24
Publication date: 2014-01-09

Abstract

[Problem] To use a rigid circuit board even in a low-profile optical pickup device. [Solution] An optical pickup device comprises: a housing having a bottom face, side faces surrounding the bottom face, and an open upper face; a laser unit mounted within the housing and emitting a laser beam in the direction along the bottom face, the laser beam being used to write and read information to and from an optical disk; an optical component mounted within the housing and disposed in the path of the laser beam; and a rigid circuit board mounted to the housing so as to overlap the laser unit from the upper face side and having an electrically conducting path formed thereon, the electrically conducting path transmitting to the laser unit a drive signal for driving the laser unit. The optical pickup device is characterized in that the rigid circuit board is mounted to the housing in such a manner that a face of the rigid circuit board, the face facing the bottom face, is located closer to the bottom face than the upper end of the laser unit.

Description

Optical pickup device

The present invention relates to an optical pickup device that performs an operation of reading a signal recorded on an optical disc and an operation of recording a signal on the optical disc.

With recent technological advances, optical pickup devices that optically record and reproduce optical signals using laser light on optical discs such as DVDs (Digital Versatile Discs) and CDs (Compact Discs) are becoming thinner. . For example, an optical pickup device generally called a slim type has a thickness of 12.7 mm, and an optical pickup device called an ultra slim type has a thickness of 9.5 mm. Various techniques have been developed for thin optical pickup devices (see, for example, Patent Document 1).

JP 2010-073229 A

In so-called thin optical pickup devices such as slim type and ultra slim type, information on optical discs using optical components such as lenses and mirrors, as well as optical components such as lenses and mirrors, in a housing with a predetermined height (12.7 mm or 9.5 mm) An electronic component such as a laser unit for recording and reading data, and a printed circuit board on which a conductive path for electrically connecting the electronic components is formed are housed in a high density. In these thin optical pickup devices, it is difficult to use a rigid substrate having a thickness of millimeter units, and it is also described as a flexible printed circuit board (hereinafter referred to as FPC (Flexible Printed Circuit)) having a thickness of several tens of micrometers. ) Is used. However, since FPC is more likely to be scratched or damaged than a rigid substrate and is expensive, a technology that makes it possible to use a rigid substrate even in a thin optical pickup device such as a slim type or an ultra slim type is desired. ing.

The present invention has been made in view of the above problems, and an object thereof is to make it possible to use a rigid substrate even in a thin optical pickup device such as a slim type or an ultra slim type.

In addition, since the rigid substrate has a lower heat dissipation than the FPC due to its thickness, material, etc., a large amount of heat generated from the laser light generating element accommodated in the housing causes an increase in the temperature of the optical pickup device. There is a fear.

For this reason, there is a demand for a technology that enables efficient release of heat generated from a laser light generating element in a thin optical pickup device using a rigid substrate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and one object is to make it possible to efficiently dissipate heat generated from a laser light generating element in a thin optical pickup device using a rigid substrate. To do.

An optical pickup device according to one aspect has a bottom surface and a side surface surrounding the bottom surface, a housing having an open top surface, and a laser beam mounted in the housing for recording and reading information on an optical disc. A laser unit that emits light in a direction along the bottom surface, an optical component that is mounted in the housing and disposed on the optical path of the laser light, and is mounted on the housing so as to overlap the laser unit from the top surface side A rigid substrate on which a conductive path for transmitting a drive signal for driving the laser unit to the laser unit is formed, the surface of the rigid substrate facing the bottom surface being an upper end portion of the laser unit. It is attached to the housing so as to be closer to the bottom surface.

An optical pickup apparatus according to one aspect has a bottom surface and a side surface surrounding the bottom surface, a housing having an open top surface, and a laser mounted in the housing for recording and reading information on an optical disc. A laser light generating element for emitting light in a direction along the bottom surface, an optical component mounted in the housing and disposed on the optical path of the laser light, and the laser light generating element on the side of the top surface A rigid substrate mounted on the housing so as to overlap the substrate and having a conductive pattern for transmitting a drive signal for emitting the laser light to the laser light generating element, the rigid substrate further comprising the laser A heat conducting pattern for taking in heat generated by the light generating element is formed.

The other problems disclosed by the present application and the solutions thereof will be clarified by the description in the column of the embodiment for carrying out the invention and the description of the drawings.

Rigid substrates can also be used in thin optical pickup devices such as slim type and ultra slim type.

Also, in a thin optical pickup device using a rigid substrate, it is possible to efficiently release heat generated from the laser light generating element.

It is a figure which shows the external appearance structure of an optical pick-up apparatus. It is a figure which shows the internal structure of an optical pick-up apparatus. It is a figure which shows the internal structure of an optical pick-up apparatus. It is a figure for demonstrating the optical system of an optical pick-up apparatus. It is a figure for demonstrating the optical system of an optical pick-up apparatus. It is a figure which shows the external appearance structure of a laser unit. It is a figure which shows a mode that a laser unit is accommodated in a housing. It is a figure which shows a mode that a laser unit is accommodated in a housing. It is a figure which shows a mode that a laser unit is accommodated in a housing. It is a figure which shows the internal structure of an optical pick-up apparatus. It is a figure which shows a mode that a laser unit is soldered to a rigid board | substrate. It is a figure which shows the generation circuit of a laser beam. It is a figure which shows a mode that a heat sink is mounted adjacent to a laser beam generating element. It is a figure which shows a mode that the pattern for heat conduction is formed in a rigid board | substrate. It is a figure which shows a mode that the heat from a laser driver is conducted to the pattern for heat conduction of a rigid board | substrate through a heat sink.

At least the following matters will become apparent from the description of this specification and the accompanying drawings.
== Overall configuration of optical pickup device ==
An external configuration of an optical pickup device 1000 according to an embodiment of the present invention is shown in FIG. An exploded perspective view of the optical pickup device 1000 is shown in FIG. The internal configuration of the optical pickup device 1000 is shown in FIG. The configuration of the optical system of the optical pickup device 1000 is shown in FIGS.

The optical pickup device 1000 is a device that performs a read operation of a signal recorded on the optical disc 5 and a recording operation of a signal on the optical disc 5 by irradiating the optical disc 5 with laser light having a predetermined wavelength.

The optical disc 5 is, for example, a BD (Blu-ray (registered trademark)) optical disc, a DVD (Digital Versatile Disc) standard optical disc, a CD (Compact Disc) standard optical disc, or the like.

Although details will be described later, as shown in FIGS. 1 and 2, the optical pickup device 1000 according to the present embodiment has a bottom surface and a side surface surrounding the bottom surface, and has a predetermined inside of the housing 300 whose top surface is open. At the position, the laser unit 100 that emits laser light, the composite optical element 210, the polarizing beam splitter 220, the quarter wavelength plate 230, the collimator lens 240, the reflection mirror 250, the AS (AStigmatism) plate 270, the objective lens driving device 400 The first heat radiating plate 500, the second heat radiating plate 600, the printed circuit board 700, and the like are accommodated, the cover 800 is attached to the upper surface of the housing 300, and the cover 800 and the housing 300 are fixed with screws 301. .

The first heat radiating plate 500 and the second heat radiating plate 600 are metal plates for effectively radiating heat generated from a heat source such as the laser unit 100.

Further, as shown in FIG. 2, the printed circuit board 700 includes a rigid substrate unit 710 formed of a rigid substrate and a flexible substrate unit 720 formed of a flexible printed circuit board (FPC). The rigid board portion 710 and the flexible board portion 720 are each formed with a conductive path, but each conductive path is electrically connected as appropriate, and is formed to be a unified conductive path in the entire printed circuit board 700. Has been.

Also, a connector 730 is attached to the rigid board portion 710. Connector 730 is provided with terminals that are respectively coupled to the respective conductive paths formed on printed circuit board 700. As shown in FIG. 1, the connector 730 is for a control circuit that is a flexible printed circuit board that is electrically connected to a main circuit board 2000 of a rigid printed circuit board in an optical disk device in which a control circuit of the optical pickup device 1000 is formed. The FPC 2100 is detachably connected.

Further, as shown in FIG. 2, a photodetector 280 and a front monitor light receiving detector 290 described later are connected to the flexible substrate unit 720. The light detector 280 and the front monitor light reception detector 290 are configured to include a light sensor that receives the laser light emitted from the laser unit 100. The light detector 280 and the front monitor light reception detector 290 transmit a signal corresponding to the detected intensity of the laser light to the main board 2000 via the control circuit FPC 2100 connected to the connector 730.

Although details will be described later, a substrate opening (through hole) 711 is formed in the rigid substrate portion 710 at a portion facing the laser unit 100.

The housing 300 has a bottom surface and a side surface surrounding the bottom surface, and has an open top surface, and is formed of a metal such as a magnesium alloy or a synthetic resin such as PPS (polyphenylene sulfide).

In FIG. 1, the Z axis is an axis along the direction of the rotation center axis 50 of the optical disk 5, and the direction from the optical pickup device 1000 toward the optical disk 5 is the + Z direction. The X axis is an axis along the direction in which the optical pickup device 1000 moves in the tracking direction of the optical disk 5 among the directions from the center of the optical disk 5 toward the outer periphery, and the direction away from the center of the optical disk 5 is the + X direction. The Y axis is an axis orthogonal to the Z axis and the X axis, and is an axis along the tangential direction of the optical disc 5.
== Optical system ==
The optical system of the optical pickup device 1000 in this embodiment will be described with reference to FIGS.

As an example, the optical pickup apparatus 1000 of the present embodiment performs recording and reproduction on the DVD standard optical disk 5 and the CD standard optical disk 5.

Therefore, the laser unit 100, when performing recording and reproduction on the DVD standard optical disk 5, for example, a laser beam having a wavelength of 655 nm (both the first laser beam) in the red wavelength band (645 nm to 675 nm) corresponding to the DVD standard. In the infrared wavelength band (765 nm to 805 nm) corresponding to the CD standard, for example, a laser beam having a wavelength of 785 nm (both the second laser beam) is emitted. ) Is emitted. That is, the laser unit 100 selectively emits one of two types of laser beams (first laser beam and second laser beam) having different wavelengths.

The laser unit 100 selectively outputs either the first laser beam or the second laser beam in accordance with the drive signal output from the main board 2000.

The laser light emitted from the laser unit 100 is irradiated onto the optical disk 5 from the objective lens 260 by various optical components 200 (210 to 290) housed in the housing 300 of the optical pickup device 1000, and then the reflected light is reflected. Guided to the photodetector 280.

FIG. 3 shows a state in which the optical component 200 constituting the optical system of the optical pickup device 1000 according to this embodiment is housed in the housing 300.

Specifically, in FIG. 3, a laser unit 100, a composite optical element 210, a polarizing beam splitter 220, a quarter-wave plate 230, a collimator lens 240, and a reflection mirror 250 (not shown in FIG. ), The objective lens 260, the AS plate 270, the light detector 280, and the front monitor light receiving detector 290 are mounted.

The optical system of the optical pickup device 1000 in this embodiment will be described with reference to FIGS.

As described above, the laser unit 100 includes, for example, a wavelength of 655 nm among the red wavelength band (645 nm to 675 nm) irradiated to the DVD standard optical disk 5 and an infrared wavelength band (765 nm to 805 nm) irradiated to the CD standard optical disk 5. ), For example, one of two types of laser beams having different wavelengths such as a wavelength of 785 nm is selectively generated.

The laser unit 100 includes a laser chip 110 described later. The laser chip 110 is formed with a first laser diode 111 having a first light emitting part for generating a first laser light and a second laser diode 112 having a second light emitting part for generating a second laser light. .

The first or second laser light selectively emitted from the laser unit 100 is incident on the composite optical element 210. The composite optical element 210 includes a half-wave plate 211 and a diffraction grating 212.

The half-wave plate 211 converts the laser light emitted from the laser unit 100 into S-polarized linearly polarized light with respect to the polarizing beam splitter 220, for example.

The diffraction grating 212 separates the laser light emitted from the laser unit 100 into three beams, a zero-order light beam, a + 1st-order diffracted light beam, and a −1st-order diffracted light beam.

For example, the polarization beam splitter 220 reflects most of the S-polarized laser light in the red wavelength band and the infrared wavelength band and transmits part of the S-polarized laser light in the red wavelength band and the infrared wavelength band. The polarization beam splitter 220 transmits most of the P-polarized laser light in the red wavelength band and the infrared wavelength band, for example.

Therefore, the polarization beam splitter 220 reflects most of the S-polarized laser light in the red wavelength band or the infrared wavelength band incident from the composite optical element 210 in the direction of the quarter wavelength plate 230, and a part of the front monitor. The light passes in the direction of the light receiving detector 290.

The front monitor light receiving detector 290 is an optical component that is used to receive the laser light transmitted through the polarization beam splitter 220 and adjust the intensity of the laser light emitted from the laser unit 100. The front monitor light receiving detector 290 outputs a monitor signal that changes according to the intensity of the detected laser light to a predetermined terminal of the connector 730 via a conductive path formed in the flexible substrate portion 720 and the rigid substrate portion 710. To do. The monitor signal is transmitted to the main board 2000 via the control circuit FPC 2100 connected to the connector 730.

The control circuit of the main board 2000 outputs a drive signal based on the monitor signal so that the laser light output from the laser unit 100 has a predetermined intensity. This drive signal is input from the main board 2000 to a predetermined terminal of the connector 730 via the control circuit FPC 2100 and input to the laser unit 100 via a laser driver (not shown) attached to the rigid board 710. Is done.

The quarter-wave plate 230 converts the laser light incident from the polarization beam splitter 220 from S-polarized linearly polarized light to circularly polarized light. The quarter-wave plate 230 converts the return light of the laser light incident from the collimator lens 240 from circularly polarized light to P-polarized linearly polarized light.

The collimator lens 240 converts the laser light incident as diffused light from the quarter wavelength plate 230 into parallel light.

The reflection mirror 250 reflects the laser light incident from the collimator lens 240 in the direction of the objective lens 260. The reflection mirror 250 reflects the return light of the laser light incident from the objective lens 260 in the direction of the collimator lens 240.

The objective lens 260 focuses the laser beam incident from the reflection mirror 250 on the signal recording layer on the recording surface of the optical disc 5.

The objective lens 260 is held by the objective lens driving device 400 as shown in FIG. The objective lens driving device 400 includes an actuator 410 and a lens holder 420. Based on a control signal transmitted from a control circuit of the main board 2000 that controls the optical pickup device 1000, the actuator 410 detects the position of the lens holder 420 and the like. By controlling the direction, focusing control, tracking control, and the like are performed so that the laser light passing through the objective lens 260 attached to the lens holder 420 is appropriately applied to the signal recording layer of the optical disc 5.

The return light of the laser light reflected by the signal recording layer of the optical disk 5 is converted into parallel light by the objective lens 260, then passes through the collimator lens 240 through the reflection mirror 250, and is circularly polarized by the quarter wavelength plate 230. To P-polarized linearly polarized light.

The return light of the laser light that has become P-polarized light passes through the polarization beam splitter 220 and enters the AS plate 270.

The AS plate 270 generates astigmatism in the return light of the laser light transmitted through the polarization beam splitter 220 and focuses it on the photodetector 280. The AS plate 270 is configured, for example, by tilting a parallel plate in a predetermined direction in consideration of the astigmatism generation direction.

The photodetector 280 detects the return light of the laser light incident from the AS plate 270. The light detector 280 is configured to include a light receiving unit that receives the return light of the laser light separated into three beams by the diffraction grating 212, and reads information recorded on the signal recording layer of the optical disc 5. A reproduction signal for performing, a focus error signal for performing focusing control, and a tracking error signal for performing tracking control are generated. These reproduction signal, focus error signal, and tracking error signal are transmitted to the main board 2000.

As described above, the optical pickup apparatus 1000 according to the present embodiment can cope with recording and reproduction of a DVD and also with recording and reproduction of a CD.
== Laser unit ==
Next, the laser unit 100 according to the present embodiment will be described in detail with reference to FIG. As shown in FIG. 6, the laser unit 100 according to the present embodiment includes a frame part 120, a resin mold part 130, a laser chip 110, a submount 150, a first terminal 141, a second terminal 142, And a third terminal 143.

The frame portion 120, the resin mold portion 130, the laser chip 110, and the submount 150 are collectively referred to as a main body portion. In this case, the laser unit 100 has a structure in which laser light is emitted from the main body and the first terminal 141, the second terminal 142, and the third terminal 143 extend from the main body.

The frame portion 120 is made of a substantially flat plate made of metal, and a submount 150 made of a dielectric is attached. The laser chip 110 is fixed to the submount 150. The frame unit 120 is grounded via the second terminal 142.

The laser chip 110 is configured by forming, for example, a first laser diode 111 that emits first laser light and a second laser diode 112 that emits second laser light on a crystal substrate of GaAs (gallium arsenide). The

The first terminal 141 and the third terminal 143 are input terminals for inputting a drive signal of the laser unit 100 output from the main board 2000. The second terminal 142 is grounded.

The first terminal 141, the second terminal 142, and the third terminal 143 extend from the resin mold part 130 in the direction opposite to the laser light emission direction.

As will be described in detail later, when the laser unit 100 is mounted on the housing 300 and then the rigid board portion 710 is mounted on the housing 300 so as to overlap the laser unit 100, the first terminal 141 of the laser unit 100, the first The two terminals 142 and the third terminals 143 are soldered to conductive paths formed in the rigid board portion 710, respectively. The first terminal 141 and the third terminal 143 are conductively connected to the main board 2000 via the control circuit FPC 2100, and the second terminal 142 is grounded.

The laser unit 100 emits the first laser beam in the red wavelength band from the first laser diode 111 when a predetermined drive signal is input from the main substrate 2000 to the first terminal 141. Further, when a predetermined drive signal is input from the main board 2000 to the third terminal 143, the laser unit 100 emits the second laser light in the infrared wavelength band from the second laser diode 112.

The resin mold part 130 is a synthetic resin formed so as to cover part of both surfaces of the frame part 120. The resin mold part 130 fixes the first terminal 141 and the third terminal 143, and insulates the first terminal 141 from the frame part 120 and the third terminal 143 from the frame part 120, respectively.

Also, the resin mold part 130 has a wall surface surrounding the laser chip 110 so as to surround three directions except for the direction in which the laser light is emitted.

As described above, the second terminal 142 and the frame portion 120 are connected so as to be conductive. For example, the second terminal 142 and the frame portion 120 are integrally formed.
== Installation of laser unit ==
Next, with reference to FIG. 7A, FIG. 7B, and FIG. 7C, how the laser unit 100 according to the present embodiment is mounted on the housing 300 will be described in detail.

FIG. 7A is a diagram illustrating a state in which the laser unit 100 and the rigid board portion 710 are mounted on the housing 300 when viewed from the upper surface side of the housing. FIG. 7B is a diagram illustrating a state in which the laser unit 100 and the rigid substrate unit 710 are mounted on the housing 300 when viewed from the first laser diode 111 and the second laser diode 112 of the laser chip 110. . FIG. 7C is a diagram illustrating a state in which the laser unit 100 and the rigid board portion 710 are mounted on the housing 300 when viewed from the direction in which laser light is emitted leftward in FIG. 7C.

As described above, the optical pickup device 1000 according to the present embodiment is configured to be able to accommodate the rigid substrate portion 710 formed of a rigid substrate in the housing 300, although it is a slim type or an ultra slim type.

First, as shown in FIG. 7A, at predetermined positions (for example, four locations) near the reference protrusion 303 formed at predetermined positions (two locations) on the bottom surface of the housing 300 on which the frame portion 120 of the laser unit 100 is mounted. The adhesive 170 is applied.

The reference protrusion 303 may be, for example, a protrusion formed integrally when forming the housing 300, or formed by fixing a resin or metal flat plate to the housing 300 with an adhesive or the like. It may be what was done.

7B and 7C, the laser unit 100 is mounted on the bottom surface 302 of the housing 300 so that the frame portion 120 of the laser unit 100 is brought into contact with the adhesive 170. At this time, the laser unit 100 is mounted so that laser light is emitted in a direction along the bottom surface 302 of the housing 300 (for example, the −X direction), and the first terminal 141, the second terminal 142, and the third terminal 143 are provided. The housing 300 is mounted so as to extend in a direction along the bottom surface 302 (for example, + X direction).

Here, when the laser unit 100 is attached to the bottom surface 302 of the housing 300, the reference protrusion in the height direction of the laser unit 100 is brought into contact with the abutting surface of the housing 300 with which the lower surface of the frame portion 120 of the laser unit 100 abuts. By forming the portion 303, the laser unit 100 sets the distance from the lower end of the housing 300 to the center of the optical axis as h2, as shown in FIG. 7B.

Next, the rigid board portion 710 is mounted from the upper surface side of the housing 300 so as to overlap the laser unit 100. At this time, the substrate opening 711 that opens to the rigid substrate portion 710 is aligned with the position of the resin mold portion 130 of the laser unit 100, and the upper end 131 of the resin mold portion 130 penetrates the substrate opening 711 so that the rigid substrate is formed. The part 710 is attached to the housing 300.

As described above, the optical pickup device 1000 according to the present embodiment is provided with the substrate opening 711 in the rigid substrate portion 710, and the laser unit 100 is inserted into the substrate opening 711 so that the rigid substrate portion 710 is housed in the housing. As shown in FIG. 7B, the height h1 from the lower end portion of the housing 300 to the upper end portion of the rigid board portion 710 can be suppressed.

That is, the optical pickup device 1000 according to the present embodiment can prevent the height of the housing 300 from increasing in the height direction even when a rigid substrate is used. Even if it exists, it becomes possible to use a rigid board | substrate.

At this time, as shown in FIG. 7C, the rigid board portion 710 is mounted on the housing 300 so as to be connected to the first terminal 141, the second terminal 142, and the third terminal 143 of the laser unit 100. More specifically, each of the first terminal 141, the second terminal 142, and the third terminal 143 of the laser unit 100 can be connected to three conductive paths formed on the rigid substrate portion 710, respectively. 710 is attached to the housing 300. For example, the conductive path of the rigid board portion 710 and the first terminal 141, the second terminal 142, and the third terminal 143 are connected using a connector or connected by soldering.

In the optical pickup device 1000 according to the present embodiment, the first terminal 141, the second terminal 142, and the third terminal 143 are soldered by the respective conductive paths and the solder 160. Details of this soldering will be described later.

Thereafter, optical components other than the objective lens 260 and the reflecting mirror 250 such as the polarizing beam splitter 220 and the collimator lens 240, which are separately mounted in the housing 300, are determined with a molding accuracy of the housing by an installation portion formed in the housing 300. The position and angle of the reflection mirror 250 are fixedly bonded to the housing 300 by adjusting the position and angle of the reflection mirror 250 by an adhesive, and the optical axis of the laser beam incident on the objective lens 260 is finely adjusted. In other words, by adjusting the mounting position of the reflection mirror 250, it is adjusted so as to absorb the tolerance of the distance h2 from the lower end of the housing 300 to the center of the optical axis, and the laser light incident on the objective lens 260 is adjusted. It is adjusted so that there is no tilt.

FIG. 8 shows a state in which the rigid substrate portion 710 is mounted on the housing 300 in the optical pickup device 1000 according to the present embodiment. As shown in FIG. 8, the substrate opening 711 of the rigid substrate portion 710 is formed in a portion facing the laser unit 100 so as to be able to penetrate the upper end portion 131 of the resin mold portion 130 of the laser unit 100. The resin mold portion 130 of the laser unit 100 passes through the substrate opening 711 formed in the rigid substrate portion 710.

The rigid board portion 710 includes a connector 730 on a surface opposite to the surface facing the bottom surface 302 of the housing 300 (that is, a surface facing the + Z axis direction). 1, the control circuit FPC 2100 connected to the main board 2000 is detachably connected to the connector 730.

As described above, the optical pickup device 1000 according to the present embodiment can be equipped with the connector 730 that can be detachably connected to the control circuit FPC 2100 by providing the rigid substrate portion 710. Thereby, for example, even when there are a plurality of types of main boards 2000 connected to the optical pickup device 1000, a plurality of types of control circuit FPCs 2100 that can be commonly coupled to the connector 730 are created according to each main board 2000. As a result, the optical pickup device 1000 can be shared. As a result, the cost can be reduced by the mass production effect of the optical pickup device 1000.

Further, for example, even if the control circuit FPC 2100 is damaged, the optical pickup apparatus 1000 can be used as it is only by exchanging only the control circuit FPC 2100, so that repair work can be facilitated and repaired. Costs can also be reduced.

When the rigid board portion 710 is attached to the housing 300, as shown in FIG. 8, for example, the ends of the rigid board portion 710 are attached to a pair of rigid board fixing claws 320 formed on the inner wall surface of the housing 300. And the rigid board portion 710 is pushed in the direction of the bottom surface 302 of the housing 300 (the −Z axis direction) to fit. Thereafter, a cover 800 or the like is attached from above the rigid substrate portion 710 and then fixed with screws 301.

Next, FIG. 9 shows a state in which the first terminal 141, the second terminal 142, and the third terminal 143 of the laser unit 100 according to the present embodiment are soldered to the conductive path of the rigid board portion 710.

As shown in FIG. 9, the first terminal 141, the second terminal 142, and the third terminal 143 of the laser unit 100 are visually recognized from the outside on the bottom surface 302 of the housing 300 according to the present embodiment, and these terminals are respectively rigid. A housing opening 310 for soldering to the conductive path of the substrate part 710 is formed.

At the time of manufacturing the optical pickup device 1000, the first terminal 141, the second terminal 142, and the third terminal 143 of the laser unit 100 are soldered through the housing opening 310.

As described above, by providing the housing opening 310 on the bottom surface 302 of the housing 300, the soldering operation between the laser unit 100 and the rigid board 710 can be facilitated.

Further, since the laser unit 100 is directly soldered to the rigid board portion 710, the height h1 from the lower end portion of the housing 300 to the upper end portion of the rigid board portion 710 is suppressed as shown in FIGS. 7B and 7C. It becomes possible to do.

Accordingly, even if a rigid substrate is used, the height of the housing 300 can be prevented from increasing in the height direction. Therefore, even in the slim type or ultra slim type optical pickup device 1000, the rigid substrate can be used. It becomes possible.

Next, the laser unit 100 and the laser driver 180 will be described with reference to FIG. As shown in FIG. 10, the laser unit 100 and the laser driver 180 are mounted on the rigid board portion 710 by soldering. The laser unit 100 and the laser driver 180 are connected by a conductive pattern formed on the rigid substrate portion 710 and constitute a circuit for emitting laser light.

The main board 2000 outputs a predetermined control signal for controlling the laser driver 180 when the laser light is emitted, and this control signal is supplied to the laser driver 180 on the rigid board portion 710, and the laser driver 180 receives the control signal. The laser unit 100 is driven by a drive signal corresponding to the above.

Specifically, first, a power supply voltage is applied to the laser driver 180 via the connector 730.

Then, when the main board 2000 outputs a first control signal to emit the first laser beam, the first control signal is input to the laser driver 180. The laser driver 180 outputs a drive signal between the first terminal 141 and the second terminal 142 of the laser unit 100. Then, the laser unit 100 emits the first laser light from the first laser diode 111.

Further, when the main board 2000 outputs a second control signal for emitting the second laser light, the second control signal is input to the laser driver 180. The laser driver 180 outputs a drive signal between the third terminal 143 and the second terminal 142 of the laser unit 100. Then, the laser unit 100 emits the second laser light from the second laser diode 112.

As described above, the optical pickup device 1000 of the present embodiment emits laser light by using the laser unit 100 and the laser driver 180. For this reason, the laser unit 100 and the laser driver 180 of this embodiment function as a laser beam generating element. The control signal output for the main substrate 2000 to control the laser driver 180 and the drive signal output for the laser driver 180 to drive the laser unit 100 are both for causing the laser light to be emitted. It is included in the drive signal.
== Heat dissipation structure ==
The laser unit 100 and the laser driver 180 generate laser light using appropriate power in order to appropriately record and read information on the optical disc 5. Therefore, corresponding heat is generated from the laser unit 100 and the laser driver 180. Therefore, it is necessary to release this heat appropriately.

In particular, in the optical pickup device 1000 according to the present embodiment, various optical components 200 and electronic components are mounted in a thin housing 300 at a high density, and the laser unit 100 and the laser driver 180 are mounted from the upper surface side of the housing 300. Since the rigid substrate portion 710 is mounted so as to overlap, the heat generated from the laser unit 100 and the laser driver 180 is required to be released more efficiently.

Therefore, in addition to the conductive pattern for transmitting signals for driving the electronic components such as the laser unit 100 and the laser driver 180, the rigid substrate unit 710 according to the present embodiment, as shown in FIG. A heat conducting pattern 712 that conducts heat generated by the laser unit 100 and the laser driver 180 is formed.

In this way, the heat conducting pattern 712 is formed on the rigid substrate portion 710, and the heat generated from the laser unit 100 and the laser driver 180 is released to the heat conducting pattern 712, so that the laser unit 100 and the laser driver 180 are formed. It becomes possible to cool effectively.

Although details will be described later with reference to FIG. 13, the heat conducting pattern 712 according to the present embodiment is formed by laminating the surface of the rigid substrate portion 710 and the inside of the rigid substrate portion 710 along the surface of the rigid substrate portion 710. The metal layer is formed.

These metal layers are connected by a metal plating 714 that covers the surface of a through hole 713 (through hole) that penetrates each metal layer laminated between one surface of the rigid substrate portion 710 and the other surface. It is configured to be.

With such a configuration, more heat generated by the laser unit 100 and the laser driver 180 can be quickly transferred to the heat conducting pattern 712 to be dissipated. Of course, the heat conducting pattern 712 may be a single metal layer formed on or inside the rigid substrate portion 710.

Further, as shown in FIG. 2, the optical pickup device 1000 according to the present embodiment includes a first heat radiating plate 500 and a second heat radiating plate 600 made of metal. The first heat radiating plate 500 is mounted in the housing 300 so as to be adjacent to the laser unit 100, and the second heat radiating plate 600 is mounted in the housing 300 so as to be adjacent to the laser driver 180.

Therefore, the heat generated from the laser unit 100 is taken into the heat conducting pattern 712 of the rigid substrate unit 710 via the first heat radiating plate 500, and the heat generated from the laser driver 180 passes through the second heat radiating plate 600. The heat conducting pattern 712 of the rigid substrate portion 710 is incorporated.

By adopting such a structure, the heat generated from the laser unit 100 and the laser driver 180 is effectively transmitted to the first heat radiating plate 500 and the second heat radiating plate 600 made of metal, and in addition, a rigid substrate. It can also be transmitted to the heat conducting pattern 712 of the portion 710. Thereby, the heat from the laser unit 100 and the laser driver 180 can be radiated more effectively.

In addition, by adopting a structure including the first heat radiating plate 500 and the second heat radiating plate 600 made of metal, the heat conducting pattern 712 of the rigid substrate portion 710 can be downsized. For this reason, the rigid substrate portion 710 itself can be reduced in size, and the optical pickup device 1000 can also be reduced in size.

Of course, the optical pickup device 1000 according to the present embodiment may be configured not to include the first heat radiating plate 500 and the second heat radiating plate 600. In this case, the heat generated from the laser unit 100 and the laser driver 180 is transmitted to the heat conducting pattern 712 without passing through the first heat radiating plate 500 and the second heat radiating plate 600, but the first heat radiating plate 500 and the second heat radiating plate 500 Since the heat radiating plate 600 is not provided, the optical pickup device 1000 can be reduced in weight and size.

Furthermore, as shown in FIG. 11, the optical pickup device 1000 according to the present embodiment has a thermal conductivity between the laser unit 100 and the first heat dissipation plate 500, but an insulating heat dissipation gel (thermally conductive elastic material). 900 is interposed. The heat generated by the laser unit 100 is taken into the first heat radiating plate 500 via the heat radiating gel 900.

The heat dissipating gel 900 is made of an elastic resin. Therefore, the laser unit 100 and the first heat radiating plate 500 can be elastically brought into contact with each other. Therefore, for example, a distance between the laser unit 100 and the first heat radiating plate 500 due to aging, manufacturing error, or the like. Even if is changed, the heat conduction path can be maintained.

Similarly, in the optical pickup device 1000 according to the present embodiment, as shown in FIG. 13, a heat radiating gel (thermally conductive elastic material) 900 is interposed between the laser driver 180 and the second heat radiating plate 600. I am doing so. The heat generated by the laser driver 180 is taken into the second heat radiating plate 600 via the heat radiating gel 900.

Therefore, the laser driver 180 and the second heat radiating plate 600 can be elastically brought into contact with each other. Therefore, for example, a distance between the laser driver 180 and the second heat radiating plate 600 due to aging, manufacturing error, or the like. Even if is changed, the heat conduction path can be maintained.

As described above, the optical pickup device 1000 according to this embodiment can be configured not to include the first heat radiating plate 500 and the second heat radiating plate 600. In this case, the heat from the laser unit 100 and the laser driver 180 is transmitted to the heat conducting pattern 712 of the rigid board portion 710 without passing through the first heat radiating plate 500 or the second heat radiating plate 600. In this case, the optical pickup device 1000 can be reduced in weight and size.

In this case, a heat radiating gel (thermally conductive elastic material) 900 may be interposed between the laser unit 100 or the laser driver 180 and the heat conducting pattern 712 of the rigid substrate portion 710.

In this case, the heat generated by the laser unit 100 and the laser driver 180 is taken into the heat conducting pattern 712 via the heat radiating gel 900.

By doing so, it becomes possible to make elastic contact between the laser unit 100 and the rigid substrate unit 710, or between the laser driver 180 and the rigid substrate unit 710. Thus, for example, even when the distance between the laser unit 100 and the rigid substrate unit 710 or the distance between the laser driver 180 and the rigid substrate unit 710 changes, the heat conduction path can be maintained. Become.

Next, the heat conductive pattern 712 formed on the rigid substrate unit 710 according to the present embodiment will be described with reference to FIG. FIG. 13 shows as an example the case where the heat generated by the laser diode 180 is released, but the same applies to the case where the heat generated by the laser unit 100 is released.

As shown in FIG. 13, the heat conducting pattern 712 according to the present embodiment is formed by a plurality of metal layers formed by being laminated on the surface and inside of the rigid substrate unit 710 along the surface of the rigid substrate unit 710. ing.

The metal layer constituting the heat conducting pattern 712 can be made of copper, gold, or the like, like the conductive pattern. Since copper and gold have high thermal conductivity, the heat generated by the laser unit 100 and the laser driver 180 can be quickly and efficiently exhausted.

Further, the heat conducting pattern 712 may be shared with the conductive pattern formed on the rigid substrate unit 710. In this way, since the area of the pattern formed on the rigid substrate portion 710 can be reduced, the rigid substrate portion 710 can be downsized.

In that case, a conductive pattern having a ground potential formed on the rigid substrate portion 710 may be used as the heat conducting pattern 712. The rigid substrate portion 710 is formed with a conductive pattern having a large area of ground potential, usually called a solid pattern, for improving noise resistance, lowering impedance, and the like. This solid pattern is used as the heat conduction pattern 712. Thus, it is possible to effectively form the heat conducting pattern 712 having a large heat capacity.

The optical pickup apparatus 1000 according to this embodiment has been described above. However, according to the optical pickup apparatus 1000 according to this embodiment, a rigid substrate can be used even in a thin optical pickup apparatus such as a slim type or an ultra slim type. It becomes possible.

In the above embodiment, the configuration in which the substrate opening 711 is opened in the rigid substrate portion 710 and the upper end 131 of the laser unit 100 is penetrated through the substrate opening 711 has been described as an example. However, the housing 300 of the rigid substrate portion 710 is described. As long as the surface 715 (the surface facing the −Z axis direction) opposite to the bottom surface 302 of the laser unit 100 is configured to be closer to the bottom surface 302 of the housing 300 than the upper end portion 131 of the laser unit 100, It may be configured.

For example, a recess (concave portion) may be formed in the portion of the rigid substrate portion 710 that faces the laser unit 100 so that the upper end portion 131 of the laser unit 100 cannot be inserted. In this case, the rigid substrate portion 710 is mounted on the housing 300 so that the upper end portion 131 of the laser unit 100 is fixed in a state of being inserted into the recess.

As a result, the rigid substrate portion 710 can be mounted close to the bottom surface 302 of the housing 300 as much as the upper end portion 131 of the laser unit 100 enters the recess, and the optical pickup device 1000 can be thinned. It becomes possible.

Alternatively, when the rigid board portion 710 is attached to the housing 300, a cut portion that bypasses the laser unit 100 may be formed in the rigid board portion 710.

According to such a configuration, the rigid substrate portion 710 is mounted closer to the bottom surface 302 of the housing 300 than the upper end portion 131 of the laser unit 100 without causing the rigid substrate portion 710 and the laser unit 100 to interfere with each other. Thus, the optical pickup device 1000 can be made thinner.

Further, according to the optical pickup device 1000 according to the present embodiment, heat generated from laser light generating elements such as the laser unit 100 and the laser driver 180 can be efficiently released in a thin optical pickup device using a rigid substrate. Is possible.

Further, for example, in the case of the optical pickup device 1000 using the resin housing 300, when heat generated from the laser light generating element is transmitted to the housing 300, the heat is generated inside the housing 300, and the housing 300 is deformed. However, it is generated from the laser light generating element by forming the heat conducting pattern 712 that conducts the heat generated by the laser light generating element on the rigid substrate portion 710 as in this embodiment. It is possible to effectively release the heat to be transmitted and to reduce the amount of heat transmitted to the housing 300.

In the above-described embodiment, the case of a dual wavelength laser compatible with DVD and CD has been described as an example of the laser unit 100. It may be a three-wavelength laser adapted to the Blu-ray Disc (registered trademark) standard, or a one-wavelength laser or a two-wavelength laser corresponding to any one or two of them.

In the above-described embodiment, the slim type (height 12.7 mm) or ultra slim type (height 9.5 mm) optical pickup apparatus 1000 has been described as an example. However, in the optical pickup apparatus 1000 of other thicknesses (for example, thinner), There may be.

As mentioned above, the embodiments of the invention described above are for facilitating understanding of the present invention, and are not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and equivalents thereof are also included in the present invention.

5 Optical disc 50 Rotating shaft 100 Laser unit 110 Laser chip 111 First laser diode 112 Second laser diode 120 Frame portion 130 Resin mold portion 140 Input terminal 141 First terminal 142 Second terminal 143 Third terminal 150 Submount 160 Solder 170 Adhesion Agent 200 Optical component 210 Composite optical element 211 1/2 wavelength plate 212 Diffraction grating 220 Polarizing beam splitter 230 1/4 wavelength plate 240 Collimator lens 250 Reflecting mirror 260 Objective lens 270 AS plate 280 Photodetector 290 Front monitor light receiving detector 300 Housing 301 Screw 310 Housing opening 320 Rigid substrate fixing claw 400 Objective lens driving device 410 Actuator 420 Lens holder 500 First heat sink 60 0 Second heat sink 700 Printed circuit board 710 Rigid board 711 Board opening 712 Heat conduction pattern 713 Through hole 714 Metal plating 720 Flexible board 730 Connector 800 Cover 900 Heat radiation gel 1000 Optical pickup device 2000 Main board 2100 FPC for control circuit

Claims

A housing having a bottom surface and a side surface surrounding the bottom surface, the top surface being open;
A laser unit that is mounted in the housing and emits laser light in a direction along the bottom surface for recording and reading information on an optical disc;
An optical component mounted in the housing and disposed on the optical path of the laser beam;
A rigid substrate mounted on the housing so as to overlap the laser unit from the upper surface side, and having a conductive path for transmitting a drive signal for driving the laser unit to the laser unit;
With
The optical pickup device, wherein the rigid substrate is attached to the housing such that a surface facing the bottom surface is closer to the bottom surface than an upper end portion of the laser unit.
The optical pickup device according to claim 1,
In the rigid substrate, a through-hole that is open so as to be able to pass through the upper end of the laser unit is formed in a portion facing the laser unit, and the upper end of the laser unit passes through the through-hole. An optical pickup device fixed to a housing.
The optical pickup device according to claim 1,
The rigid substrate has a recess into which the upper end of the laser unit can be inserted in a portion facing the laser unit, and is fixed to the housing with the upper end of the laser unit being inserted into the recess. An optical pickup device.
The optical pickup device according to claim 1,
2. The optical pickup device according to claim 1, wherein the rigid substrate is formed with a notch that bypasses the laser unit when mounted on the housing.
The optical pickup device according to any one of claims 1 to 4,
The laser unit has an input terminal to which the drive signal is input, and is attached to the housing such that the input terminal extends in a direction along the bottom surface of the housing,
The optical pickup device, wherein the conductive path of the rigid board and the input terminal of the laser unit are soldered when the rigid board is mounted on the housing.
The optical pickup device according to claim 5,
The optical pickup device according to claim 1, wherein the housing has an opening formed on the bottom surface for soldering the input terminal to the conductive path.
The optical pickup device according to any one of claims 1 to 6,
The rigid board includes a connector that can be detachably connected to a flexible printed board connected to a control circuit that outputs the drive signal, on a surface opposite to a surface opposite to the bottom surface. An optical pickup device.
A housing having a bottom surface and a side surface surrounding the bottom surface, the top surface being open;
A laser light generating element that is mounted in the housing and emits laser light for recording and reading information to and from the optical disc in a direction along the bottom surface;
An optical component mounted in the housing and disposed on the optical path of the laser beam;
A rigid substrate mounted on the housing so as to overlap the laser light generating element from the upper surface side, and having a conductive pattern for transmitting a driving signal for emitting the laser light to the laser light generating element;
With
The optical pickup device, wherein the rigid substrate is further formed with a heat conducting pattern for taking in heat generated by the laser light generating element.
The optical pickup device according to claim 8, wherein
A metal heat dissipating plate mounted in the housing adjacent to the laser light generating element and taking in heat generated by the laser light generating element;
The optical pickup device, wherein the heat conducting pattern formed on the rigid substrate takes in heat generated by the laser light generating element via the heat radiating plate.
The optical pickup device according to claim 9, wherein
A heat conductive elastic material interposed between the laser light generating element and the heat radiating plate;
2. The optical pickup device according to claim 1, wherein the heat radiating plate takes in heat generated by the laser light generating element via the thermoconductive elastic material.
The optical pickup device according to claim 8, wherein
A heat conductive elastic material interposed between the laser light generating element and the heat conducting pattern of the rigid substrate;
The optical pickup device, wherein the heat conducting pattern of the rigid substrate takes in heat generated by the laser light generating element via the thermoconductive elastic material.
The optical pickup device according to any one of claims 8 to 11,
The heat conducting pattern formed on the rigid substrate is formed of a plurality of metal layers formed by laminating on the surface and inside of the rigid substrate along the surface of the rigid substrate. An optical pickup device, wherein the rigid substrate is connected by a metal covering a surface of a through hole penetrating each metal layer between one surface and the other surface.
A resin housing having a bottom surface and a side surface surrounding the bottom surface, the top surface being open;
A laser light generating element that is mounted in the housing and emits laser light for recording and reading information to and from the optical disc in a direction along the bottom surface;
An optical component mounted in the housing and disposed on the optical path of the laser beam;
A metal heat conduction plate mounted in the housing adjacent to the laser light generating element and taking in heat generated by the laser light generating element;
The laser light generating element is mounted on the housing so as to overlap the heat conduction plate from the upper surface side, and a conductive pattern for transmitting a drive signal for driving the laser light generating element to the laser light generating element is formed. A rigid board,
With
An optical pickup device, wherein the heat conducting plate is interposed between the housing and the rigid substrate.
The optical pickup device according to claim 13,
The optical pickup device according to claim 1, wherein a part of the heat conducting plate is disposed to be exposed from between the housing and the rigid substrate.
The optical pickup device according to claim 13,
A laser driver for driving the laser light generating element is installed on the back surface of the rigid substrate,
The thermal conductive plate is configured by a first thermal conductive plate thermally coupled adjacent to the laser light generating element and a second thermal conductive plate thermally coupled relative to the laser driver. Optical pickup device.
The optical pickup device according to claim 15,
A metal heat conduction plate that is mounted in the housing adjacent to the laser light generation element and takes in heat generated by the laser light generation element. The rigid substrate is taken in via the first heat conduction plate. A heat conducting pattern for taking in the heat generated by the laser light generating element is formed,
An optical pickup device characterized by that.