JP2005322299A - Optical head device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical head device in which the fixing position of a laser emitting element to a frame is adjustable in an optical axis direction of laser beam and moreover the heat generated in the laser emitting element can be dissipated effectively. <P>SOLUTION: The optical head device 1 provided with a 1st laser emitting element 2, an objective lens 10, a light receiving element 13, and a frame 15, is further provided with a heat sink 19 for dissipating the heat generated in the 1st laser emitting element 2. A holder 18 for holding the 1st laser emitting element 2 is fixedly bonded to the frame 15 via a gap G1. Moreover, the 1st laser emitting element 2 and the heat sink 19 are arranged with a gap G2 in-between, and also the gap G2 between the laser emitting element 2 and the heat sink 19 is filled with a gelatinous heat transfer member having heat transfer property or a heat transfer member having heat transfer property and elasticity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optical head device used for recording and reproduction of optical disks such as CDs and DVDs. More specifically, the present invention relates to a heat dissipation structure of a laser light emitting element provided in the optical head device.

  An optical head device used for recording and reproduction of an optical disk such as a CD or a DVD has a laser light emitting element as a light source, an objective lens for converging the laser light emitted from the laser light emitting element to the optical disk, and a return light from the optical disk. And a frame to which an optical system such as a laser light emitting element is fixed.

In this type of optical head device, a high-power laser light-emitting element for recording on an optical disk is used as the laser light-emitting element. Since this high-power laser light emitting element generates a large amount of heat, it is necessary to effectively dissipate heat generated in the laser light emitting element. Therefore, conventionally, a structure in which the holder for holding the laser light emitting element is bonded and fixed to the frame via a heat conductive plate in surface contact with the frame to effectively dissipate heat generated in the laser light emitting element. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 2004-14007

  In the optical head device disclosed in Patent Document 1, the holder that holds the laser light emitting element is brought into contact with the frame via a plate having heat conductivity, so that heat generated in the laser light emitting element can be used by using the frame. Can be effectively dissipated. However, since the holder needs to be bonded and fixed in contact with the plate that is in surface contact with the frame, the fixing position of the laser light emitting element in the optical axis direction cannot be adjusted. For this reason, another optical component must be adjusted after the laser light emitting element is fixed to the frame, resulting in a problem that it takes time to adjust the optical system. In addition, since the other optical components can be adjusted only after the laser light emitting element is fixed to the frame, there is a problem that the degree of freedom in the adjustment process of the optical system is reduced.

  Here, by using an adhesive having heat conductivity to fix the laser light emitting element to the frame, it is possible to adjust the fixing position of the laser light emitting element in the optical axis direction while ensuring heat dissipation. However, considering the workability in the bonding process, the amount of the adhesive used is limited, and there is a problem that the heat generated in the laser light emitting element cannot be sufficiently dissipated by the adhesive.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical head device capable of adjusting the fixing position of the laser light emitting element to the frame in the optical axis direction of the laser light and effectively dissipating heat generated in the laser light emitting element. Is to provide.

  In order to solve the above problems, in the present invention, a laser light emitting element as a light source, an objective lens for converging a laser beam emitted from the laser light emitting element onto an optical disk, and a light receiving element that receives return light from the optical disk And an optical head device including at least a frame to which the laser light emitting element is fixed, including a heat radiator that dissipates heat generated in the laser light emitting element, the laser light emitting element being fixed to the frame by bonding, and A fixing position of the laser light emitting element to the frame can be adjusted in the optical axis direction of the laser light, the laser light emitting element and the heat radiating body are disposed with a gap therebetween, and the laser The gap between the light emitting element and the heat radiating body is filled with a heat transfer member having a heat transfer property such as a gel heat transfer member or a heat transfer member having heat transfer property and elasticity. And wherein the door.

  In the present invention, for example, the optical head device further includes a holder for holding the laser light emitting element, and the holder is fixed to the frame by bonding with a gap.

  In the present invention, for example, by fixing the holder for holding the laser light emitting element to the frame via a predetermined gap, the fixing position of the laser light emitting element to the frame can be adjusted in the optical axis direction of the laser light. It has become. In addition, the heat radiating body that dissipates heat generated in the laser light emitting element and the laser light emitting element are disposed via a gap, and the gap between the laser light emitting element and the heat radiating body is provided with a gel-like heat transfer having heat conductivity. A heat member or a heat transfer member having heat transfer properties and elasticity is filled. Therefore, the heat generated by the laser light emitting element can be effectively dissipated by the heat radiator through the heat transfer member. Further, the influence of the laser light emitting element on the stress generated from the heat radiating element is small enough to be ignored. In other words, since a gel-like or elastic member is employed as the heat transfer member, even if the heat radiator is deformed due to a temperature change or the like, the stress generated from the heat sink based on this deformation or the like is the heat transfer. Absorbed by the member, the laser light emitting element is hardly affected by the stress. Therefore, even if the laser light emitting element is bonded and fixed to the frame without using a rigid body such as a holder or a plate as in the prior art, the mounting position of the laser light emitting element is not shifted due to the stress generated from the heat radiating body. Therefore, even when the laser light emitting element is fixed to the frame in the optical axis direction of the laser beam, the laser light emitting element can be stably fixed to the frame.

  Here, when the laser light emitting element is fixed to the frame, the holder for holding the laser light emitting element may be adhered to the frame via a predetermined gap as described above, or the laser light emitting element may be bonded via the predetermined gap. May be adhered to the frame.

  In the present invention, the heat transfer member is preferably a thermally conductive grease. A heat conductive grease that is a general-purpose product and is easily available is inexpensive and can reduce the product cost of the optical head device. In addition, since the heat conductive grease is in a gel form, even when the laser light emitting element is bonded and fixed to the frame and the heat radiating body is fixed, the heat conduction member that is a heat transfer member is interposed in the gap between the laser light emitting element and the heat radiating body. Can be filled with functional grease.

  In the present invention, the laser light emitting element includes a terminal extended to the opposite side of the laser light emitting direction, and the heat radiator is a heat radiating plate disposed on the terminal side of the laser light emitting element. Can do. Further, the heat radiating body may be the frame itself in the laser beam emission direction to which the laser light emitting element is bonded and fixed.

  In the present invention, it is preferable that the heat radiating plate includes a heat radiating portion for radiating heat generated in the laser light emitting element on the optical disc side. In this case, convection is generated by the rotation of the optical disk, and the heat of the heat sink can be effectively dissipated.

  In this invention, it is preferable that the said heat sink is provided with the opening part formed in the extension direction of the said terminal. In this case, a short circuit between the terminal and the heat sink can be reliably prevented. In addition, the heat transfer member can be filled into the gap between the laser light emitting element and the heat radiating plate from the opening, and the work of filling the heat transfer member is facilitated.

  In the present invention, the heat transfer member preferably has electromagnetic wave absorption characteristics. In this case, noise generated from the laser light emitting element can be absorbed by the heat transfer member, and malfunction of the optical head device that can be caused by noise of the laser light emitting element can be prevented.

  As described above, in the optical head device according to the present invention, the position where the laser light emitting element is fixed to the frame can be adjusted in the optical axis direction of the laser light. Therefore, after fixing other optical components to the frame, the laser light emitting element can be adjusted and fixed to the frame. Therefore, the adjustment process of the optical system is shortened. Further, it is possible to give a degree of freedom to the adjustment process of the optical system.

  In addition, the heat radiating body that dissipates heat generated in the laser light emitting element and the laser light emitting element are disposed via a gap, and the gap between the laser light emitting element and the heat radiating body is provided with a gel-like heat transfer having heat conductivity. A heat member or a heat transfer member having heat transfer properties and elasticity is filled. Therefore, the heat generated by the laser light emitting element can be effectively dissipated by the heat radiator through the heat transfer member. Furthermore, since the heat transfer member absorbs the stress generated from the heat radiating body, the influence of the laser light emitting element on the stress is small enough to be ignored. Accordingly, even if the laser light emitting element is fixed to the frame in the optical axis direction of the laser light, the laser light emitting element can be stably fixed to the frame. As a result, in the optical head device according to the present invention, the fixing position of the laser light emitting element to the frame can be adjusted in the optical axis direction of the laser light, and the heat generated in the laser light emitting element can be effectively dissipated. .

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

(Overall configuration of optical head device)
FIG. 1 is a perspective view showing the entire configuration of an optical head device according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram showing the configuration of the optical system of the optical head device shown in FIG. FIG. 3 is a bottom view showing the bottom surface of the optical head device shown in FIG. FIG. 3 shows the bottom surface of the optical head device in a state where the bottom surface cover, which is a component of the optical head device, is removed for convenience of explanation.

  The optical head device 1 according to this embodiment performs information recording and information reproduction with respect to an optical disk 30 such as a CD or a DVD, and includes a frame 15 on which an optical system described below is mounted. The frame 15 is slidably attached along two guide shafts 24 and 25 which are attached to an optical disc recording / reproducing apparatus main body (not shown) so as to be parallel to each other.

  The optical system in the optical head device 1 includes, as a light source, a first laser light-emitting element 2 that emits a long-wavelength laser light (first laser light) of 780 nm to 800 nm for CD, and a short of 630 nm or 650 nm for DVD. And a second laser light emitting element 3 that emits wavelength laser light (second laser light). The first laser light emitting element 2 includes three terminals 2a extending in the direction opposite to the laser light emission direction. Similarly, the second laser light emitting element 3 also includes three terminals 3a extending in the direction opposite to the laser light emission direction.

  In the optical system according to this embodiment, the first laser light and the second laser light are guided to the common optical path 14 toward the optical disc 30 by the prism 6 which is an optical element for optical path synthesis. The common optical path 14 includes a half mirror 7 that reflects part of the first laser light and the second laser light toward the optical disc 30, a collimator lens 8 that converts the reflected light from the half mirror 7 into parallel light, A rising mirror 9 for raising the light emitted from the collimator lens 8 toward the optical disk 30 and an objective lens 10 for converging the laser light collimated by the collimator lens 8 onto the optical disk 30 are arranged in this order. Yes.

  In guiding the first laser light emitted from the first laser light emitting element 2 to the common optical path 14, the first laser light is converted into three beams on the optical path from the first laser light emitting element 2 to the prism 6. The grating 4 to be divided and the relay lens 5 for converting the divergence angle of the laser beam divided into three beams are arranged in this order. A part of the first laser light incident on the prism 6 via the grating 4 and the relay lens 5 is reflected by the prism 6 and guided to the common optical path 14.

  Further, when the second laser light emitted from the second laser light emitting element 3 is guided to the common optical path 14, the second laser light 3 is placed on the optical path from the second laser light emitting element 3 toward the prism 6. A grating 11 for dividing the beam is disposed. A part of the second laser light incident on the prism 6 through the grating 11 passes through the prism 6 and is guided to the common optical path 14.

  A sensor lens 12 and a light receiving element 13 are arranged on the side of the half mirror 7, and the return light reflected by the optical disk 30 passes through the objective lens 10, the rising mirror 9, and the collimator lens 8. 7, and a part of the incident light passes through the half mirror 7 and is guided toward the sensor lens 12 and the light receiving element 13. That is, in this embodiment, the half mirror 7 is an optical path separation element.

  The relay lens 5 has positive power for emitting laser light having a divergence angle smaller than the divergence angle of the first laser light incident through the grating 4 to the prism 6. The relay lens 5, the grating 4, and the first laser light emitting element 2 are integrated as will be described later.

  The sensor lens 12 generates astigmatism with respect to the return light from the optical disc 30, and the magnification of the return light (the magnification of the spot on the light receiving element 13 with respect to the spot on the optical disc 30) is about 8 to 17 times. The coma aberration generated by the half mirror 7 is corrected. The sensor lens 12 forms a large spot in a circular shape on the light receiving element 13 so that a high-quality focusing servo signal and tracking servo signal can be obtained.

  In the present embodiment, in the optical system for the first laser light emitted from the first laser light emitting element 2, the magnification of the emitted light when the influence of the relay lens 5 is not taken into account (the first with respect to the spot on the optical disc 30). The magnification of the light emitting point of the laser light emitting element 2 is about 4 times, and the numerical aperture (NA) of the objective lens 10 is about 0.5. On the other hand, in the optical system for the second laser light emitted from the second laser light emitting element 3, the magnification of the emitted light (the magnification of the light emitting point of the second laser light emitting element 3 with respect to the spot on the optical disc 30) is about 5. The NA of the objective lens 10 is 0.6 to 0.68. In addition, when the influence of the relay lens 5 is taken into consideration, the magnification of the emitted light from the first laser light emitting element 2 is substantially the same as the magnification of the emitted light from the second laser light emitting element 3. Thus, the common optical path 14 can be used for the optical system of the first laser light emitting element 2 and the second laser light emitting element 3.

  The frame 15 in this embodiment is, for example, an aluminum frame formed by die casting, and includes a concave portion on which a part of the above-described optical system is mounted on the bottom surface side. The frame 15 is formed with a fixing portion 15 a for fixing the first laser light emitting element 2 on the side surface. The fixing portion 15 a is formed with an insertion hole (not shown) through which a part of the holder 18 that holds the first laser light emitting element 2 described later is inserted. As shown in FIG. 3, the second laser light emitting element 3 and the light receiving element 13 are also fixed to the side surface of the frame 15.

  The optical head device 1 also includes an objective lens driving device 16 that drives the objective lens 10 in the focusing direction and the tracking direction, and is attached to the upper surface side of the frame 15. The objective lens driving device 16 includes a tracking driving coil, a tracking driving magnet, a focusing driving coil, a focusing driving magnet, and the like, and since the configuration thereof is a known configuration, detailed description thereof is omitted. In the optical head device 1, a circuit board 23 having a drive circuit for driving the first laser light emitting element 2 and the second laser light emitting element 3 is attached to the back side of the frame 15.

(Configuration of the fixing portion of the first laser light emitting element)
FIG. 4 is an enlarged bottom view showing the fixing portion of the first laser light emitting element in an enlarged manner from the bottom surface side. FIG. 5 is an enlarged side view showing the fixed portion of the first laser light emitting element in an AA direction in FIG. 3 in an enlarged manner.

  The optical head device 1 in this embodiment includes a holder 18 that holds the first laser light emitting element 2. The first laser light emitting element 2, the grating 4, and the relay lens 5 are fixed to the holder 18, and a laser light emitting unit in which at least the first laser light emitting element 2 and the relay lens 5 are integrated is configured. ing.

  The holder 18 constituting the laser light emitting unit is bonded and fixed to the fixing portion 15 a formed on the frame 15 with an adhesive 21. In other words, the first laser light emitting element 2 is fixed to the frame 15 via the holder 18 by adhesion. More specifically, the holder 18 is fixed to the fixing portion 15a via the gap G1. Since the gap G1 is formed between the holder 18 and the fixing portion 15a, the fixing position of the holder 18 can be adjusted in the Z direction (see FIG. 4) that is the optical axis direction of the first laser beam. ing. Further, the fixing position of the holder 18 can be adjusted also in the X direction and the Y direction (see FIG. 5) which are directions orthogonal to the optical axis direction of the first laser light.

  In the present embodiment, the second laser light emitting element 3 is fixed to the frame 15 by a conventional configuration. That is, the holder 26 holding the second laser light emitting element 3 is bonded and fixed to the frame 15 via the plate plate 27 having heat conductivity brought into surface contact with the frame 15 (see FIG. 3).

  On the terminal 2 a side of the first laser light emitting element 2, a heat radiating plate 19 is disposed as a heat radiator that dissipates heat generated in the first laser light emitting element 2. More specifically, the first laser light emitting element 2 and the heat radiating plate 19 are disposed via a gap G2. In addition, the gap G2 between the first laser light emitting element 2 and the heat radiating plate 19 is filled with a gel-like heat transfer member having heat transfer properties or a heat transfer member having heat transfer properties.

  The heat sink 19 in this embodiment is formed by bending a metal plate having high heat conductivity such as copper or aluminum. The heat radiating plate 19 is attached to the optical head device 1 in a state of being attached in parallel to the XY plane, a mounting portion 19b that is bent from the base portion 19a in parallel to the YZ plane, and a base portion 19a that is bent in parallel to the XZ plane. It is comprised from the attaching part 19c. The attachment portion 19b and the attachment portion 19c are bonded and fixed in a state of being in surface contact with the frame 15 so that the heat of the heat radiating plate 19 can be dissipated to the frame 15. An opening 19 d is formed in the base 19 a of the heat sink 19 in the extending direction of the terminal 2 a of the first laser light emitting element 2, and the first laser light emitting element 2 and the heat sink 19 are attached to the frame 15. In the attached state, the base 19a and the terminal 2a are not in contact with each other.

  The heat transfer member in the present embodiment is a gel-like heat transfer member, specifically a heat conductive grease. More specifically, silicon grease is used.

(Procedure for fixing the first laser light emitting element to the frame)
In the optical head device 1 configured as described above, the first laser light emitting element 2 is fixed to the frame 15 in the following procedure.

  First, the first laser light emitting element 2 is fixed to the holder 18 together with the grating 4 and the relay lens 5 to constitute a laser light emitting unit. In this laser light emitting unit, after a part of the holder 18 is inserted into the insertion hole of the frame 15, the holder 18 is attached to the fixing portion 15 a in an adjusted state in three dimensions in the X direction, the Y direction, and the Z direction. It is bonded to 21 and fixed to the frame 15. In this state, a gap G1 is formed between the holder 18 and the fixed portion 15a.

  Thereafter, the heat radiating plate 19 whose mounting position is adjusted in the Z direction is bonded and fixed to the frame 15 at the mounting portions 19b and 19c. More specifically, the first laser light emitting element 2 and the gap G2 are bonded and fixed so as not to cause a short circuit between the terminal 2a and the heat radiating plate 19. In this state, the gap G2 is filled with silicon grease, which is thermally conductive grease, from the opening 19d. In the state where the heat sink 19 is bonded and fixed to the frame 15, a part of the terminal 2 a is disposed in the opening 19 d, and the relative distance between the first laser light emitting element 2 and the heat sink 19. Can be shortened. Therefore, the heat generated in the first laser light emitting element 2 can be effectively dissipated by the heat radiating plate 19 through the silicon grease, and the optical head device 1 can be downsized in the Z direction.

(Effect of this embodiment)
As described above, in the optical head device 1 according to the present embodiment, the holder 18 that holds the first laser light emitting element 2 is fixed to the frame 15 through the predetermined gap G1 by bonding, so that in the Z direction, The fixing position of the first laser light emitting element 2 to the frame 15 can be adjusted. Therefore, even after other optical components are fixed to the frame 15, the first laser light emitting element 2 can be adjusted and fixed to the frame 15. Therefore, the adjustment process of the optical system is shortened. Further, it is possible to give a degree of freedom to the adjustment process of the optical system.

  Further, in the present embodiment, the heat radiating plate 19 that dissipates heat generated in the first laser light emitting element 2 and the first laser light emitting element 2 are disposed via the gap G2, and the first laser light emitting element 2 and the heat sink 19 are filled with silicon grease, which is a gel-like heat transfer member having heat transfer properties. Therefore, the heat generated by the first laser light emitting element 2 can be effectively dissipated by the heat sink 19 via the silicon grease. Moreover, the influence which the 1st laser light emitting element 2 receives with the stress which arises from the heat sink 19 becomes small so that it can be disregarded. That is, since the gel-like silicon grease is used as the heat transfer member, even if the heat radiating plate 19 is deformed due to a temperature change or the like, the first laser light emitting element 2 is almost affected by the stress. There is nothing. Therefore, even if the holder 18 is bonded and fixed to the frame 15 via the gap G1, the mounting position of the first laser light emitting element 2 is not shifted due to the stress generated from the heat radiating plate 19. Accordingly, even if the first laser light emitting element 2 is configured to be adjustable in the optical axis direction (Z direction) of the first laser light, the first laser light emitting element 2 can be adjusted. Can be stably fixed to the frame 15.

  In this embodiment, silicon grease, which is a heat conductive grease, is used as the heat transfer member. Silicone grease, which is a general-purpose product and is easily available, is inexpensive. Therefore, the product cost of the optical head device 1 can be reduced by using silicon grease. Further, since the silicon grease is in a gel form, even after the holder 18 is bonded and fixed to the frame 15 and then the heat sink 19 is bonded and fixed to the frame 15, the first laser light emitting element 2 and the heat sink 19 The gap G2 can be filled with silicon grease as a heat transfer member.

  In this embodiment, the heat radiating plate 19 has an opening 19d in the extending direction of the terminal 2a. Therefore, a short circuit between the terminal 2a and the heat sink 19 can be reliably prevented. In addition, the gap G2 between the first laser light emitting element 2 and the heat radiating plate 19 can be filled with silicon grease as the heat transfer member from the opening 19d, and the filling operation of the heat transfer member is facilitated.

  In this embodiment, the magnification of the emitted light when the influence of the relay lens 5 of the optical system on the first laser light emitted from the first laser light emitting element 2 is not taken into consideration is about 4 times, and the magnification is It is set small. Therefore, for example, when recording on a CD-R, a spot having a large power can be formed on the optical disc 30. In addition, the light transmission efficiency is increased, and a large amount of light can be used with a small amount of light emission. On the other hand, the magnification of the optical system with respect to the second laser light emitted from the second laser light emitting element 3 is about 5.5 to 7 times, and the magnification is set large. Therefore, for example, a small spot can be formed on the optical disc 30 when reproducing a DVD.

  Furthermore, in this embodiment, the first laser light emitting element 2 and the relay lens 5 are integrated by the holder 18 to constitute a laser light emitting unit. The laser light emitting unit is fixed to a frame 15 on which an optical system is mounted. Therefore, the laser light emitting unit including the first laser light emitting element 2 and the relay lens 5 can be regarded as one light source, and the magnification of the optical system with respect to the light emitted from the laser light emitting unit is the magnification of the relay lens 5. It can be considered that the magnification included is taken into account, that is, the magnification considering the influence of the relay lens 5. Therefore, the difference between the magnification of the optical system and the magnification of the return light with respect to the light emitted from the laser light emitting unit can be reduced, and the optical axis position of the spot on the light receiving element 10 due to the mounting error of the laser light emitting unit is reduced. The influence can be reduced.

(Other embodiments)
The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, as in the optical head device 51 shown in FIG. 6, the heat radiating plate 59 is formed so that a heat radiating portion 59e for radiating heat generated in the first laser light emitting element 2 is provided on the upper surface side of the frame 15, that is, on the optical disc 30 side. May be. Hereinafter, the heat sink 59 will be specifically described.

  Compared with the heat dissipation plate 19 in the above-described form, the heat dissipation plate 59 has a base portion 59a extending on the upper surface side (Y direction) of the frame 15, and a heat dissipation portion parallel to the XZ plane from the Y direction end of the base portion 59a. 59e is extended. In FIG. 6, the heat dissipating part 59e has a large surface area that is the same length as the objective lens driving device 16 in the Z direction, so that heat generated in the first laser light emitting element 2 can be dissipated more effectively. It has become. Further, since the heat radiating plate 59 includes the heat radiating portion 59e on the optical disc 30 side, convection is generated by the rotation of the optical disc 30, and the heat of the heat radiating plate 59 can be effectively dissipated. The heat radiating plate 59 is formed by bending a metal plate having a high heat transfer property such as copper or aluminum in the same manner as the heat radiating plate 19, and the mounting portions 59b and 59c and the opening 59d are provided. I have.

  In the above-described embodiment, silicon grease, which is a thermally conductive grease, is used as the heat transfer member, but the heat transfer member is not limited to silicon grease. For example, as the heat transfer member, a heat conductive grease other than silicon grease, a paste-like heat conductive gel, a sheet-like heat conductive grease, a sheet-like heat conductive gel, or a heat conductive silicon rubber sheet is used. be able to. That is, as the heat transfer member, if it is a gel-like heat transfer member having heat transfer property or a heat transfer member having heat transfer property and elasticity, the above-described effective heat dissipation effect is exhibited, and the heat dissipation plate 19 is provided. The mounting position of the first laser light-emitting element 2 is not shifted due to the stress generated from the first laser light-emitting element 2, and the fixing position of the first laser light-emitting element 2 to the frame 15 can be adjusted in the optical axis direction of the first laser light. Even when configured as described above, the first laser light emitting element 2 can be stably fixed to the frame 15.

  Furthermore, as the heat transfer member, for example, a heat transfer member having electromagnetic wave absorption characteristics such as a paste-like heat conductive gel having high-frequency electromagnetic wave absorbability may be used. In this case, the generation of noise from the first laser light emitting element 2 is suppressed, and appropriate control of the optical head device 1 becomes possible.

  Furthermore, in the above-described embodiment, the silicon grease is filled between the first laser light emitting element 2 and the heat radiating plate 19, but the gap G1 between the holder 18 and the frame 15 may be filled with silicon grease. . In this case, it is necessary to consider the peeling of the adhesive 21 due to the influence of silicon grease. However, even if this configuration is adopted, the heat generated in the first laser light emitting element 2 is effectively dissipated to the frame 15. be able to.

  In the above-described embodiment, the first laser light emitting element 2 is bonded and fixed to the frame 15 via the holder 18. However, a predetermined gap is provided between the first laser light emitting element 2 and the frame 15. The first laser light emitting element 2 may be directly bonded and fixed to the frame 15 with the adhesive 21.

  Further, in the second laser light emitting element 3, as in the first laser light emitting element 2, the holder 26 and the frame 15 are bonded and fixed through a predetermined gap, and the heat radiating plate is attached. It may be provided to dissipate heat generated in the second laser light emitting element 3.

1 is a perspective view showing an overall configuration of an optical head device according to an embodiment of the present invention. It is a schematic block diagram which shows the structure of the optical system of the optical head apparatus shown in FIG. It is a bottom view which shows the bottom face of the optical head apparatus shown in FIG. It is an enlarged bottom view which expands and shows the fixing | fixed part of a 1st laser light emitting element from the bottom face side. FIG. 4 is an enlarged side view showing a fixed portion of the first laser light emitting element in an AA direction in FIG. 3 in an enlarged manner. It is a perspective view which shows the whole structure of the optical head apparatus concerning other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical head apparatus 2 1st laser light emitting element (laser light emitting element)
2a terminal 3 second laser light emitting element 10 objective lens 13 light receiving element 15 frame (heat radiator)
18 Holder 19 Heat sink (heat sink)
19d Opening 30 Optical disk 51 Optical head device 59 Heat sink (heat sink)
59d opening 59e heat dissipation part G1 gap G2 gap

Claims (7)

A laser light emitting element as a light source, an objective lens for converging laser light emitted from the laser light emitting element on an optical disc, a light receiving element for receiving return light from the optical disc, and a frame on which at least the laser light emitting device is fixed In an optical head device comprising:
A heat radiator that dissipates heat generated in the laser light emitting element,
The laser light emitting element is fixed to the frame by bonding, and the fixing position of the laser light emitting element to the frame is adjustable in the optical axis direction of the laser light,
The laser light emitting element and the heat radiating body are disposed via a gap, and the gap between the laser light emitting element and the heat radiating body is a gel-like heat transfer member having heat transfer property or heat transfer property. An optical head device filled with a heat transfer member having elasticity.   2. The optical head device according to claim 1, further comprising a holder for holding the laser light emitting element, and the holder is fixed to the frame by bonding through a gap.   3. The optical head device according to claim 1, wherein the heat transfer member is a heat conductive grease.   The laser light emitting element includes a terminal extending to the opposite side of the laser light emitting direction, and the heat radiator is a heat radiating plate disposed on the terminal side of the laser light emitting element. The optical head device according to claim 1.   5. The optical head device according to claim 4, wherein the heat radiating plate includes a heat radiating portion for radiating heat generated in the laser light emitting element on the optical disc side.   5. The optical head device according to claim 4, wherein the heat radiating plate includes an opening formed in an extending direction of the terminal.   3. The optical head device according to claim 1, wherein the heat transfer member has electromagnetic wave absorption characteristics.

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