JP3093294U - Optical pickup - Google Patents

Abstract

(57) [Summary] [Object] To precisely project a laser beam [Constitution] The engagement hole 16 penetrating in the center is positioned concentrically with the laser diode LD so as to be applied to the rear surface of the laser diode LD. The heat dissipating plate 7 has a slit 19 formed in the heat dissipating plate 7 so that a pair of tongues 7A and 7B are left uncut in a point symmetrical manner about the axis O1 of the engaging hole 16. The screw insertion recesses 20 formed in the tongues 7A, 7B are communicated with the slits 19, and the screws 22 are screwed through the screw insertion recesses 20 of the tongues 7A, 7B, whereby the heat radiation plate 7 is fixed to the base 1. Of force O2 generated at the base end of each tongue 7A, 7B by screwing the screw 22
The axis O1 is set so as to be located on an imaginary line K connecting O3, and the distances L1 and L2 from the axis O1 to the power points O2 and O3 are set to be substantially the same.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

  The present invention relates to an optical pickup used in a disc player such as a DVD. Regarding

[0002]

[Prior art]

  Conventionally, it has been described in JP-A-11-16205 as an optical pickup technology. There is one that is made of synthetic resin. A photo is made on the opening 2a at one end of the light passage hole 2 with the half mirror HM penetrating the base 1. The diode PD is arranged, and the collimator lens Q is provided at the other end opening 2b. The WP and the objective lens OL are arranged in the laser hole 3 communicating with the light passage hole 2. The laser diode LD and the diffraction grating G are arranged, and the laser diode LD The laser light from the diffraction grating G, the half mirror HM, the collimator lens QWP and the pair. It is projected onto the disc D through the object lens OL and the reflected light is transmitted through the half mirror HM. Then, the light is received by the photodiode PD and recorded on the disc D. It is designed to read information.

[0003]   The laser mounting surface 5 formed around the opening of the laser hole 3 of the base 1 is made of metal. The heat plate 4 is fastened by a plurality of (two in this configuration) screws 22, and the heat plate 4 is almost fixed. The engaging hole 4a penetrating the central portion of the cavity is positioned concentrically with the laser diode LD. By doing so, the heat sink 4 is brought into contact with the back surface of the laser diode. It is possible to prevent the laser diode LD from generating heat due to the projection of laser light and deteriorating its performance. It is like this.

[0004]

[Problems to be solved by the device]

  In the above structure, as shown in FIGS. 14A and 14B, each screw 22 is attached to the heat dissipation plate 4. Since only the through holes 4b for inserting the through holes are provided, the through holes 4b are not inserted. Then, each screw 22 is screwed into each screw hole 23 of the laser mounting surface 5, When the head 22a is pressed against the heat dissipation plate 4, the heat dissipation plate 4 is distorted and deformed. That is, the deformed heat dissipation plate 4 is separated from the laser diode LD to enhance the heat dissipation effect. In some cases, it may not be possible to fully exhibit [see the phantom line in FIG. 14 (b)].

[0005]   Therefore, as shown in FIG. 15A, a slit 4c should be formed in the heat dissipation plate 4. The pair of tongues 4A and 4B are left in a point-symmetrical manner around the axis O1 of the engagement hole 4a. Then, screw the screw 22 screw into the screw hole 23 through the through hole 4b of each tongue piece 4A, 4B. In this way, the heat sink 4 is prevented from being deformed and the laser diode LD It is conceivable to make contact with the back surface.

[0006]   According to the above-mentioned structure, each screw 22 is screwed in so that the head 22a of each screw 22 is attached to each tongue. By pressing the pieces 4A, 4B with a predetermined pressing force P, the tongue pieces 4A, 4B From the imaginary line K connecting the force points O2 and O3 generated at the base end, the axis O of the engagement hole 4a Since 1 is displaced, as shown in FIG. 15 (b), from each force point O2, O3 The pressing force P acting toward the axis O1 is the component forces P1 and P2 along the virtual line K and the virtual line K. Is divided into component forces P3 and P4 that act in a direction orthogonal to each other, Are offset, and the bending moment T generated around the axis O1 by the component forces P3 and P4. Is acted on the laser diode LD via the heat dissipation plate 4, whereby the laser die The laser light projected from the laser diode LD is not positioned because the ode LD is displaced. As a result, it becomes difficult to accurately read the information recorded on the disc D. There is

[0007]   In view of the above-mentioned difficulties, the present invention prevents displacement of a laser diode to refine laser light. Aiming to provide an optical pickup capable of dense projection ing.

[0008]

[Means for Solving the Problems]

  In order to achieve the above-mentioned object, the device according to claim 1 has a base made of synthetic resin. When the photodiode is placed at the opening of one end of the light passage hole with the half mirror In both of them, a collimator lens and an objective lens are arranged in the opening at the other end, and A laser diode is arranged in the laser hole communicating with the through hole, Laser light from ode through half mirror, collimator lens and objective lens Projects on a disc, and the reflected light is received by a photodiode via a half mirror. The optical pick that reads the information recorded on the disc. It is up to the laser mounting surface formed around the opening of the laser hole of the base. A metal holder to be locked, and a metal radiator plate attached to the outer peripheral surface of the holder And a laser diode in a locking hole that is concentric with the laser hole of the holder. And the engagement hole that is slightly smaller than the locking hole that penetrates almost the center of the heat sink. The laser diode is positioned by concentrically positioning the dowel hole on the laser diode. The card is sandwiched between the heat sink and the holder, and a slit is formed in the heat sink. A pair of tongues are left in a point-symmetrical manner around the axis of the engaging hole, and are formed on each tongue. The screw insertion recess and the screw insertion recess of each tongue piece are communicated with the slit. By screwing a screw through the through hole of the laser into the screw hole formed on the laser mounting surface The heat sink and holder are fixed to the base, and the base of each tongue is fixed by screwing the screws. Set so that the axis of the engaging hole is located on the virtual line that connects the force points generated at the ends. And the distance from the shaft center to each force point is set to be substantially the same. By forming a recess on the laser mounting surface excluding the peripheral edge of the An air gap is formed between the base and the base, and a large number of heat radiation fins are projected on the holder. It is characterized by being.

[0009]   According to the above configuration, the base passes through the screw insertion recess of each tongue and the through hole of the holder. The heat sink is fixed to the base by screwing the screw into the screw hole of Since each tongue is only partially connected to the heat sink, It can be abutted on the backside of the laser diode without shaping.

[0010]   In addition, the peripheral edge of the screw insertion recess of each tongue has a substantially C-shaped shape that is easily elastically deformed. Since it is molded, it is necessary to press the head of the screw against each tongue with a predetermined pressing force. Therefore, the force point can be reliably generated at the base end portion of each tongue piece.

[0011]   On the imaginary line connecting the two force points, Are positioned so that the distance from the axis to each force point is almost the same. Therefore, the pressing forces acting from each force point toward the axial center cancel each other out, No component force is generated from the both pressing forces. Therefore, centering around the axis of the engaging hole as in the past No bending moment is generated, and the bending moment causes The laser diode is no longer displaced, and laser light is emitted from the laser diode. Accurate projection of the information recorded on the disc by precisely projecting the Can be read.

[0012]   Furthermore, since the laser diode is attached to the base via the holder, If the laser diode is determined to be defective in the inspection before shipment, the laser diode All you have to do is discard the iodine. Therefore, disconnect from the defective laser diode. The diffraction grating and base can be reused, and the disposal cost is low. Also, Since the holder isolates the base from the heat generated by the laser diode, its base It is possible to prevent the soot from being thermally expanded and deformed.

[0013]   Furthermore, since the laser diode is sandwiched between the holder and the heat sink, The laser diode can be securely locked in the locking hole of the holder. Because there is no need for screws or other locking means, manufacturing costs are reduced by the amount that is no longer needed. You can do it.

[0014]   Moreover, the heatsink and the holder are integrally fixed to the base with screws. It requires less screws compared to the case where the heat sink and the holder are attached separately. Fastening work can be performed easily.

[0015]   In addition, the contact area between the laser diode and the holder and heat sink is large, Since a large number of heat radiation fins are projected on the The laser diode can be operated efficiently, and the holder can The base is isolated from the heat generated by the laser diode, and the holder and the base are partially Contact with each other, the heat generated by the laser diode causes There is no risk of thermal expansion of the lens and deformation, and the photodiode and objective lens It is possible to prevent the occurrence of reading errors by keeping the optical axis that connects them in a straight line as specified. Therefore, an inexpensive and highly accurate optical pickup can be manufactured.

[0016]   According to a second aspect of the present invention, there is provided a laser which communicates with a light passage hole formed through a synthetic resin base. A laser diode is placed in the laser hole, and the laser diode By projecting light on the disc and receiving the reflected light with a photodiode, An optical pickup designed to read information recorded on a disc, An engagement hole penetrating approximately in the center is positioned concentrically with the laser diode. Has a heat dissipation plate that is brought into contact with the back surface of the laser diode by The pair of tongues are left in a point-symmetrical manner around the shaft center of the engaging hole And the screw insertion recess formed on each of the tongues is communicated with the slit. The heat sink plate is screwed into the screw hole of the base through the screw insertion recess of It is fixed to the base and the force points generated at the base end of each tongue by screwing the screws are set. It is set so that the shaft center of the engagement hole is located on the imaginary line running, and The feature is that the distances from each point to each power point are set to be almost the same.

[0017]   According to the above configuration, the screw is inserted into the screw hole of the base through the screw insertion recess of each tongue piece. The tongue pieces dissipate heat by fixing the heatsink to the base by inserting. Since it is only partially connected to the plate, do not deform the heat sink It can be brought into contact with the back surface of the laser diode.

[0018]   In addition, the peripheral edge of the screw insertion recess of each tongue has a substantially C-shaped shape that is easily elastically deformed. Since it is molded, it is necessary to press the head of the screw against each tongue with a predetermined pressing force. Therefore, the force point can be reliably generated at the base end portion of each tongue piece.

[0019]   Furthermore, on the imaginary line connecting the two force points, the engagement hole formed in the approximate center of the heat sink is The shaft center is set so that the distance from the shaft center to each force point is almost the same. Since it is set to one, the pressing forces acting from each force point toward the axial center cancel each other out. Therefore, no component force is generated from the both pressing forces. Therefore, centering on the axis as in the past No bending moment is generated, and the bending moment causes the The diode is no longer displaced and laser light is emitted from the laser diode. Accurate projection of information recorded on the disc by precisely projecting without misaligning Can be read.

[0020]   The invention according to claim 3 is a laser formed around the opening of the laser hole of the base. It has a metal holder that is locked to the mounting surface and is concentric with the laser hole of the holder. The laser diode is fitted in the penetrating locking hole.

[0021]   According to the above configuration, the laser diode is attached to the base via the holder. Therefore, if the laser diode is determined to be defective in the inspection before shipment, You just have to discard the laser diode. Therefore, the defective laser diode Diffraction grating and base can be reused after detached from the module, resulting in low disposal cost Tsuku. Also, is the holder isolated from the heat generated by the laser diode? It is possible to prevent the base from being thermally expanded and deformed.

[0022]   A fourth aspect of the present invention is the device of the third aspect, wherein the holder and the heat dissipation are The laser diode is sandwiched between the plate and the plate.

[0023]   According to the above configuration, is the laser diode sandwiched between the holder and the heat sink? The laser diode can be securely locked in the locking hole of the holder. Since a locking means such as a screw is unnecessary for locking, only the part that is no longer needed is manufactured. The cost of production can be reduced, and the connection between the laser diode and the holder or heat sink can be reduced. The large contact area provides high heat dissipation.

[0024]   A fifth aspect of the present invention is the device of the fourth aspect, wherein the screws of the tongues are Insert a screw into the screw hole formed on the laser mounting surface through the insertion recess and the through hole of the holder. It features that the heat sink and the holder are fixed to the base by ing.

[0025]   According to the above configuration, the radiator plate and the holder are integrally fixed to the base by the screw. This is less than the case where the heatsink and holder are attached separately. Fastening work can be done quickly and easily with a screw.

[0026]   The invention according to claim 6 is the device according to any one of claims 2 to 5, Of the inner peripheral surface of the holder and the laser mounting surface, the circumference of one or both screw holes By forming a recess in the part excluding the edge, the holder and the base can be inserted through the recess. It is characterized in that a void is formed between and.

[0027]   According to the above configuration, the holder and the base are only partially in contact with each other. Since the base is not much affected by the heat generated by the laser diode, its base It is possible to prevent the fiber from being thermally deformed.

[0028]   The invention according to claim 7 is the device according to any one of claims 2 to 6, It is characterized in that a large number of heat radiation fins are projectingly provided on the holder.

[0029]   According to the above configuration, the large number of heat radiation fins protruding from the holder further promotes heat radiation. Thus, the laser diode can be operated efficiently.

[0030]

[Embodiment of device]

  1 to 7 show an optical pickup according to an embodiment of the present invention. And is locked to the laser attachment surface 5 formed around the opening of the laser hole 3 of the base 1. A metal holder 6 and a metal radiator plate 7 attached to the outer peripheral surface of the holder 6 are provided. is doing. The configuration other than the above is almost the same as the configuration shown in FIGS. 13 to 15. , The same parts are designated by the same reference numerals, and the description thereof will be omitted.

[0031]   The base 1 is made of a hard synthetic resin and is molded as shown in FIGS. 2 and 7. And a cylindrical base body 1a having the laser mounting surface 5 formed thereon, and the base body 1a. And a pair of brackets 1 integrally projecting from the board portion 1b. c and the rack 1d, the through holes 9 of both brackets 1c are provided in the guide rod 10. A pinion (not shown) that is movably fitted and meshes with the rack 1d is rotated in the forward and reverse directions. By doing so, the base 1 is moved forward and backward a, b along the guide rod 10.

[0032]   As shown in FIGS. 3 and 4, the holder 6 has substantially the same size as the laser mounting surface 5. Has a rectangular holder main body 6a, and the laser Large diameter portion 12a having substantially the same diameter as the outer diameter of the ion LD, and slightly smaller than the large diameter portion 12a A locking hole 12 composed of a small-diameter portion 12b having a small diameter is formed through the locking hole 12, and the locking hole 12 is inserted into the locking hole 12. Laser diode LD is fitted, and the locking hole 12 is sandwiched between the inner peripheral surface of the holder body 6a. Two positioning recesses 13 that are recessed on the laser mounting surface 5 By fitting them into the respective convex portions 14, the laser diode is inserted through the holder 6. The laser diode LD is positioned concentrically with the laser hole 3 (see FIG. 8).

[0033]   According to the above configuration, the laser diode LD is mounted on the base 1 via the holder 6. Since the laser diode LD is attached, it is judged as a defective product by the inspection before shipping. In case of damage, the laser diode LD need only be discarded. Therefore, defective products Reuse the diffraction grating G and the base 1 separated from the laser diode LD of The disposal cost is low. In addition, the holder 6 allows the laser diode LD Since the base 1 is isolated from heat generation, the base 1 is thermally expanded and deformed. Can be prevented.

[0034]   As shown in FIGS. 1 and 3, the heat dissipation plate 7 faces the holder 6 and faces the holder 6. A radiator plate body 7a that is slightly larger than the radiator plate body 7a, and the base 1 side from both ends of the radiator plate body 7a. It consists of a pair of left and right vanes 7b and 7c bent in the An engaging hole 16 having a diameter slightly smaller than the engaging hole 12 is formed in the portion, Two positioning holes 17 formed with the engaging hole 16 sandwiched therebetween are provided on the holder body 6a so as to project. The heat radiating plate 7 is attached to the holder 6 by fitting them into the respective positioning protrusions 18. And the engaging hole 16 is concentric with the engaging hole 12, The ode LD is sandwiched between the holder 6 and the heat dissipation plate 7 (see FIG. 8).

[0035]   Further, by forming the slits 19 in the radiator plate body 7a, a pair of tongue pieces 7A, 7B is left in a point-symmetrical manner with the axial center O1 of the engagement hole 16 as the center, and the tongues 7A and 7B are cut off. The screw insertion concave portion 20 formed in B is communicated with the slit 19, and the tongues 7A, 7 Insert the screw 22 through the screw insertion recess 20 of B and each through hole 21 of the holder body 6a. The heat sink 7 and the holder 6 are screwed into the screw holes 23 of the laser mounting surface 5 so that the heat sink 7 and the holder 6 are It is fixed to the mounting surface 5 (see FIG. 9).

[0036]   According to the above configuration, the tongues 7A and 7B are partially connected to the heat dissipation plate 7. Therefore, the rear surface of the laser diode LD should be made so that the heat dissipation plate 7 is not deformed. Can be brought into contact with.

[0037]   Further, since the laser diode LD is sandwiched between the holder 6 and the heat dissipation plate 7, The laser diode LD can be securely locked in the locking hole 12 of the holder 6. Since the locking means such as a screw is unnecessary for the locking, it is no longer necessary. The production cost can be reduced by just that much.

[0038]   Furthermore, the heat sink 7 and the holder 6 are integrally fixed to the base 1 by the screw 22. Compared to the case where the heat dissipation plate 7 and the holder 6 are separately fixed, Fastening work can be performed quickly and easily with no screws 22.

[0039]   As shown in FIGS. 12A and 12B, the tongues 7A, 7 On the imaginary line K connecting the force points O2 and O3 generated at the base end portion of B, the axis O of the engagement hole 16 1 is set to be located, and from the axis O1 to each of the force points O2 and O3. The distances L1 and L2 are set to be substantially the same.

[0040]   According to the above configuration, the peripheral edge portion of the screw insertion recess 20 of each tongue piece 7A, 7B is substantially C-shaped. Since it is molded into a shape that is easily elastically deformed, a screw 2 is attached to each of the tongue pieces 7A and 7B. By pressing the head portion 22a of the second head 2 with a predetermined pressing force P, the tongue pieces 7A, 7A Force points O2 and O3 can be reliably generated at the base end portion of B.

[0041]   In addition, the pressing forces P acting from the power points O2 and O3 toward the axis O1 cancel each other out. Therefore, no component force is generated from the both pressing forces P. Therefore, as in the conventional case, the engagement hole 16 A bending moment centered on the axis O1 (see bending moment T in FIG. 15) is generated. Without changing the bending moment, the laser diode LD is changed via the heat sink 7. The laser light from the laser diode LD is displaced. To accurately read the information recorded on the disc D by projecting it accurately without You can

[0042]   As shown in FIGS. 1 and 2, the laser mounting surface 5 excluding the peripheral edge portion 5 a of each screw hole 23. To form a concave portion 25 in each of the screw holes 23 and to form the peripheral edge portion 5a of each screw hole 23 to be higher. As a result, a space α is formed between the holder 6 and the base 1 through the recess 25. Since the holder 6 and the base 1 are only partially in contact with each other, 1 is not so affected by heat generated by the laser diode LD.

[0043]   As shown in FIGS. 3 and 4, the entire outer peripheral surface of the holder body 6a and the peripheral edge of the inner peripheral surface thereof. A large number of radiating fins 26 are projected on the part, and by the large number of radiating fins 26, It is possible to further promote heat dissipation and operate the laser diode LD efficiently.

[0044]   In short, the contact area between the laser diode LD, the holder 6 and the heat sink 7 is Since the holder 6 has a large number of heat radiation fins 26, the laser diode To accelerate the heat generation of the laser diode LD and to operate the laser diode LD efficiently. In addition, the holder 6 separates the base 1 from the heat generated by the laser diode LD. At the same time, the holder 6 and the base 1 are only partially in contact with each other. The synthetic resin base 1 is thermally expanded and deformed by the heat generated by the laser diode LD. Without it, the optical axis O connecting the photodiode PD and the objective lens OL (see FIG. 13). Illumination) can be maintained in a straight line as desired to prevent reading errors. This makes it possible to manufacture an inexpensive and highly accurate optical pickup.

[0045]   In FIG. 3, 28 is a leaf spring presser spring, which includes a ring portion 28a and the ring portion 28a. 28a and a pair of leg portions 28b that are integrally projected and extend outward. As shown in FIG. 11, while inserting the ring portion 28a into the laser hole 3, By inserting 28b into the pair of groove portions 29 communicating with the laser hole 3, the pushing The spring 28 is elastically deformed and interposed between the holder 6 and the diffraction grating G. Thus, the diffraction grating G is prevented from rotating unexpectedly.

[0046]   As shown in FIGS. 6 and 11, the base body 1a has a diffraction hole communicating with the laser hole 3. The grid operation hole 30 is provided so as to diffract the operation rod 31 inserted into the operation hole 30. By contacting the outer peripheral surface of the grating G and operating the operating rod 31, the diffraction grating G is moved. The laser light is rotated to disperse the laser light as desired.

[0047]   In the above structure, the recess 2 is formed in order to form the space α between the holder 6 and the base 1. 5 is formed on the laser mounting surface 5, but it is not limited to this, and the recess 25 May be formed on the inner peripheral surface of the holder 6, or the recess 25 may be formed on the inner peripheral surface of the holder 6. It may be formed on both the laser attachment surface 5.

[0048]

[Effect of device]

  According to the invention of claim 1, the screw insertion recess of each tongue and the through hole of the holder are Fix the heat sink to the base by screwing a screw through the screw hole of the base. And each tongue is only partially connected to the heat sink, The heat sink can be brought into contact with the back surface of the laser diode without being deformed. Wear.

[0049]   In addition, the peripheral edge of the screw insertion recess of each tongue has a substantially C-shaped shape that is easily elastically deformed. Since it is molded, it is necessary to press the head of the screw against each tongue with a predetermined pressing force. Therefore, the force point can be reliably generated at the base end portion of each tongue piece.

[0050]   On the imaginary line connecting the two force points, Are positioned so that the distance from the axis to each force point is almost the same. Therefore, the pressing forces acting from each force point toward the axial center cancel each other out, No component force is generated from the both pressing forces. Therefore, centering around the axis of the engaging hole as in the past No bending moment is generated, and the bending moment causes The laser diode is no longer displaced, and laser light is emitted from the laser diode. Accurate projection of the information recorded on the disc by precisely projecting the Can be read.

[0051]   Furthermore, since the laser diode is attached to the base via the holder, If the laser diode is determined to be defective in the inspection before shipment, the laser diode All you have to do is discard the iodine. Therefore, disconnect from the defective laser diode. The diffraction grating and base can be reused, and the disposal cost is low. Also, Since the holder isolates the base from the heat generated by the laser diode, its base It is possible to prevent the soot from being thermally expanded and deformed.

[0052]   Furthermore, since the laser diode is sandwiched between the holder and the heat sink, The laser diode can be securely locked in the locking hole of the holder. Because there is no need for screws or other locking means, manufacturing costs are reduced by the amount that is no longer needed. You can do it.

[0053]   Moreover, the heatsink and the holder are integrally fixed to the base with screws. It requires less screws compared to the case where the heat sink and the holder are attached separately. Fastening work can be performed easily.

[0054]   In addition, the contact area between the laser diode and the holder and heat sink is large, Since a large number of heat radiation fins are projected on the The laser diode can be operated efficiently, and the holder can The base is isolated from the heat generated by the laser diode, and the holder and the base are partially Contact with each other, the heat generated by the laser diode causes There is no risk of thermal expansion of the lens and deformation, and the photodiode and objective lens It is possible to prevent the occurrence of reading errors by keeping the optical axis that connects them in a straight line as specified. Therefore, an inexpensive and highly accurate optical pickup can be manufactured.

[0055]   According to the invention of claim 2, the screw of the base is passed through the screw insertion recess of each tongue piece. By screwing a screw into the hole, the heat sink is fixed to the base, Do not deform the tongue because each tongue is only partially connected to it. It can be brought into contact with the back surface of the laser diode in any way.

[0056]   In addition, the peripheral edge of the screw insertion recess of each tongue has a substantially C-shaped shape that is easily elastically deformed. Since it is molded, it is necessary to press the head of the screw against each tongue with a predetermined pressing force. Therefore, the force point can be reliably generated at the base end portion of each tongue piece.

[0057]   Furthermore, on the imaginary line connecting the two force points, the engagement hole formed in the approximate center of the heat sink is The shaft center is set so that the distance from the shaft center to each force point is almost the same. Since it is set to one, the pressing forces acting from each force point toward the axial center cancel each other out. Therefore, no component force is generated from the both pressing forces. Therefore, centering on the axis as in the past No bending moment is generated, and the bending moment causes the The diode is no longer displaced and laser light is emitted from the laser diode. Accurate projection of information recorded on the disc by precisely projecting without misaligning Can be read.

[0058]   According to the invention of claim 3, the laser diode is attached to the base via the holder. Since it is installed, the laser diode is judged to be defective by inspection before shipping. If it does, the laser diode need only be discarded. Therefore, the defective product Laser diode can be reused and the grating or base separated from the diode can be discarded. The cost is cheap. In addition, the holder separates the base from the heat generated by the laser diode. Since they are separated, the base can be prevented from being thermally expanded and deformed.

[0059]   According to the invention of claim 4, the laser diode is sandwiched between the holder and the heat dissipation plate. Therefore, the laser diode must be securely locked in the locking hole of the holder. Since there is no need for a locking device such as a screw to lock the lock, it is not necessary. The manufacturing cost can be reduced by just the amount of time, and the laser diode, holder and Since the contact area with the heat sink is large, the heat dissipation effect is high.

[0060]   According to the fifth aspect of the invention, the radiator plate and the holder are integrally formed with screws by means of screws. It is designed to be attached to the heat sink and the heatsink and holder separately. In comparison, the fastening work can be performed quickly and easily with a few screws.

[0061]   According to the invention of claim 6, the holder and the base are partially in contact with each other. If the base is not affected by the heat generated by the laser diode The base can be prevented from being thermally deformed.

[0062]   According to the invention as set forth in claim 7, the plurality of heat dissipating fins projecting from the holder dissipate the heat. The heat can be further promoted to operate the laser diode efficiently.

[Brief description of drawings]

FIG. 1 is a perspective view of an optical pickup according to an embodiment of the present invention.

FIG. 2 is a perspective view of the base.

FIG. 3 is an exploded perspective view of the heat dissipation structure.

FIG. 4 is a perspective view of an inner peripheral surface side of the holder.

FIG. 5 is a front view of the optical pickup.

FIG. 6 is a side view of the optical pickup.

FIG. 7 is a plan view of the optical pickup.

FIG. 8 is a view on arrow AA of FIG.

FIG. 9 is a view taken along the line BB of FIG.

FIG. 10 is a view on arrow CC of FIG.

FIG. 11 is a view on arrow DD of FIG.

FIG. 12A is an explanatory diagram showing the action of the pressing force applied to the heat dissipation plate, and FIG. 12B is a principle diagram thereof.

FIG. 13 is a principle diagram showing a conventional example.

14 (a) is a front view of a heat sink, and FIG. 14 (b) is EE.
FIG.

15A is an explanatory diagram showing the action of pressing force in a modification of the heat dissipation plate, and FIG. 15B is a principle diagram thereof.

[Explanation of symbols]

1 base 2 Light passing hole 3 laser holes 5 Laser mounting surface 6 holder 7 Heat sink 7A, 7B tongue 16 engagement holes 19 slits 20 Screw insertion recess 22 screws 22a screw head 23 screw holes 25 recess 26 Radiation fin HM half mirror PD photodiode QWP collimator lens OL objective lens LD laser diode D disk α void O1 Engagement hole axis O2, O3 K A virtual line connecting the power points P pressing force

Claims (7)

[Scope of utility model registration request] 1. A photodiode is arranged at one end opening of a light passage hole with a half mirror penetrating through a synthetic resin base, and a collimator lens and an objective lens are arranged at the other end opening, and the light passage is provided. A laser diode is arranged in a laser hole communicating with the hole, the laser light is projected from the laser diode onto a disk through a half mirror, a collimator lens and an objective lens, and the reflected light is reflected through a half mirror to a photodiode. An optical pickup configured to read information recorded on a disc by receiving light by a metal holder that is locked to a laser mounting surface formed around an opening of a laser hole of the base, A metal heat sink attached to the outer peripheral surface of the holder, and in a locking hole concentrically formed with the laser hole of the holder. By fitting the laser diode and positioning an engagement hole having a diameter slightly smaller than the locking hole penetrating substantially in the center of the heat dissipation plate concentrically with the laser diode, the laser diode functions as a heat dissipation plate and a holder. The pair of tongues are left to be cut symmetrically about the axis of the engaging hole by forming a slit in the heat dissipation plate, and the screw insertion recess formed in each tongue is formed in the slit. The radiator plate and the holder are fixedly attached to the base by screwing the screws into the screw holes formed on the laser mounting surface through the screw insertion recesses of each tongue and the through holes of the holder. The shaft center of the engagement hole is set to be located on a virtual line connecting the force points generated at the base end portions of the tongues, and the distance from the shaft center to each force point is set to be substantially the same. Screw hole By forming a concave portion on the laser mounting surface excluding the edge portion, a space is formed between the holder and the base through the concave portion, and a large number of heat radiation fins are projectingly provided on the holder. Optical pickup. 2. A laser diode is arranged in a laser hole communicating with a light passage hole penetrating a synthetic resin base, the laser light is projected onto a disk, and the reflected light is reflected by a photodiode. An optical pickup adapted to read information recorded on a disc by receiving light, wherein a rear surface of the laser diode is formed by concentrically positioning an engaging hole penetrating in a substantially central portion of the laser diode. A pair of tongues are left in a symmetrical manner about the shaft center of the engaging hole by forming a slit in the radiator plate, and formed on each of the tongues. The screw insertion recess is communicated with the slit, and the heat sink is fixed to the base by screwing the screw into the screw hole of the base through the screw insertion recess of each tongue piece. Is set so that the shaft center of the engaging hole is located on a virtual line connecting the force points generated at the base ends of the tongues, and the distances from the shaft center to the force points are set to be substantially the same. An optical pickup that is characterized by 3. A metal holder that is locked to a laser mounting surface formed around the opening of the laser hole of the base, and has a locking hole that is concentric with the laser hole of the holder. The optical pickup according to claim 2, wherein a laser diode is fitted in the optical pickup. 4. The optical pickup according to claim 3, wherein a laser diode is sandwiched between the holder and the heat dissipation plate. 5. A heat sink and a holder are fixed to a base by screwing a screw into a screw hole formed on a laser mounting surface through a screw insertion recess of each tongue piece and a through hole of a holder. The optical pickup according to claim 4, which is characterized in that. 6. A recess is formed in a portion of the inner peripheral surface of the holder and the laser mounting surface excluding the peripheral portion of one or both of the screw holes, so that the holder and the base are connected via the recess. The optical pickup according to any one of claims 2 to 5, wherein a gap is formed between them. 7. The optical pickup according to claim 2, wherein a large number of heat radiation fins are projectingly provided on the holder.