JP2012043489A - Optical pickup device and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that an earth terminal of a laser diode drive circuit provided on a flexible wiring board is brought to electrical continuity with a coating plate of an optical pickup device when fixing the coating plate by a screw, in order to protect the optical pickup device from electrostatic breakdown, but the screw cannot be adopted because of reduced thickness of the optical pickup device (housing) and thus static electricity cannot be discharged.SOLUTION: A conducting part is provided in a conductive support plate supporting a laser diode drive circuit in a housing of an optical pickup device. An earth terminal provided on a flexible wiring board is brought to electrical continuity with the conducting part, and the conductive support plate is brought to electrical continuity with a conductive coating plate. The conductive support plate is fixed to the housing by a hook-shaped fixing part, and a hook-shaped conduction part clasps the earth terminal. The conductive coating plate is fixed to the housing by a fook, and the conductive coating plate is conductive to the earth terminal without using the screw.

Description

  The present invention relates to an optical pickup device and a manufacturing method thereof, and more particularly to an optical pickup device having a thin outer shape and strong against electrostatic breakdown and a manufacturing method thereof.

  The optical pickup device has a function of irradiating an optical disc with laser light having a predetermined wavelength emitted from a light emitting element (laser diode) and detecting the laser light reflected by the information recording layer of the optical disc with a light receiving element. ing. Thus, an information reading operation or writing operation can be performed on the optical disc.

  In addition, optical elements such as a light emitting element, a light receiving element, and a half mirror constituting the optical pickup device are incorporated in a housing in which a synthetic resin material is integrally molded by an injection molding method. The housing is covered with a covering plate, and the covering plate and the housing are fixed with screws. The covering plate is made of, for example, a metal material, and is provided for protecting the inside of the housing (see, for example, Patent Document 1).

  Furthermore, when the optical pickup device is shipped as a product, or when an optical pickup driving device (so-called traverse mechanism or assembling work into an optical disk device, etc. is performed), the operator picks up the optical pickup device via a cover plate, for example. If static electricity is applied, the laser diode inside the housing may be electrostatically destroyed (electrostatic discharge (ESD) destruction). A technique for discharging static electricity applied to the optical pickup device 500 by fixing it to the ground potential has been developed.

  FIG. 11 is a diagram showing an outline of a conventional optical pickup device 500. FIG. 11 (A) is a perspective view mainly showing the inside of the housing and the flexible printed circuit board, and FIG. 11 (B) is the housing and this. It is a perspective view which mainly shows the coating plate to cover.

  Referring to FIG. 11A, in the optical pickup device 500, an optical element such as a laser diode or a half mirror, an actuator for driving an objective lens, etc. Is incorporated.

  Further, a laser diode driver circuit (laser diode driver (LDD)) for driving a laser diode (not shown) is fixed to a flexible printed circuit board (FPC) 503 and covers the main surface of the housing 502. Is placed. A ground terminal 503G is provided at the end of the FPC 503.

  Referring to FIG. 11B, cover plate 505 is made of a metal substrate such as stainless steel (SUS). The cover plate 505 is fixed to the housing 502 with hooks 507 and screws 508, and thereby the FPC 503 is accommodated below the cover plate 505. At this time, the ground terminal 503G of the FPC 503 is exposed below the cover plate 505 in the screwing area 509 (FIG. 11A), and these are fixed together with the screw 508. As a result, the cover plate 505 is electrically connected to the ground terminal 503G and becomes a ground potential. With this structure, even when static electricity is applied to the optical pickup device 500 from the operator or the like through the cover plate 505, it can be discharged, and the ESD tolerance of the optical pickup device can be improved. .

JP 2007-102826 A

  Along with the downsizing and thinning of optical disc apparatuses, the market demand is for downsizing and thinning of optical pickup apparatuses. As an example of reducing the thickness of the optical pickup device, it is possible to reduce the thickness t ′ (see FIG. 11B) of the housing 502, which has been about 5 mm, to about 3.5 mm.

  However, since the housing 502 is thinned, it is difficult to make the covering plate 505 and the ground terminal 503G of the FPC 503 conductive.

  In the optical pickup device 500 of FIG. 11 in which the thickness t ′ of the housing 502 is about 5 mm, the size of the screw 508 that fastens the cover plate 505 and the ground terminal 503G of the FPC 503 is required to be sufficiently small. Further, in the case of the housing 502 formed by injection molding using a synthetic resin material, deterioration of the housing 502 due to prior tapping is also a problem. For these reasons, the conventional optical pickup device 500 employs a self-tapping screw 508 that is small in size and can be screwed only by drilling without performing tapping.

  However, if the thickness t ′ of the housing 502 is reduced to, for example, about 3.5 mm, even the self-tapping screw 508 cannot be employed. When using the self-tapping screw 508, the tightening torque, repeated tightening torque, and loosening torque are usually evaluated, and the conditions of the pilot hole (the depth and diameter (size) of the hole on the housing 502 side) so as to satisfy the specified value. Select the screw type. However, if the thickness of the housing 502 is thin, the number of screw threads must be reduced (one or two), and the housing 502 does not function as a screw.

  For this reason, it is necessary to eliminate the screw (self-tapping screw) 508 in the entire housing 502, and a technique for preventing electrostatic breakdown by conduction between the cover plate 505 and the ground terminal 503G of the FPC 503 by conventional tightening of screws. There was a problem that could not be adopted.

  The present invention has been made in view of such a problem. First, a housing in which an optical element is accommodated, a laser diode that is accommodated in the housing and emits the laser light, and a conductive material that is locked in the housing. A flexible board formed with a support plate, a laser diode drive circuit provided on the conductive support plate, a conductive pattern electrically connected to the laser diode drive circuit, and a ground terminal of the laser diode drive circuit A conductive wiring board; and a conductive cover plate that covers a part of one main surface of the housing and is locked to the housing, wherein the conductive support plate has a conductive portion, and the ground terminal This is solved by contacting the conductive portion and holding the ground terminal and the conductive cover plate through the conductive support plate.

  Second, a step of fixing a laser diode driving circuit to a flexible wiring board provided with a conductive pattern and a ground terminal and connecting the laser diode drive circuit to the ground terminal; a step of housing an optical element in a housing; A step of electrically connecting to the flexible wiring board; a step of locking a conductive support plate having a conductive portion in a housing; and the laser diode driving circuit being disposed on the conductive support plate, One end of a flexible wiring board is sandwiched between the conductive portions, the ground terminal is brought into contact with the conductive portion, and the laser diode driving circuit and the laser diode are housed in the housing; and one main surface of the housing A conductive covering plate covering a part is brought into contact with a part of the conductive supporting plate and locked to the housing, and the conductive covering plate is interposed via the conductive supporting plate. It solves by anda step of conducting the one ground terminal.

  According to the present invention, the following effects can be obtained.

  First, the conductive cover plate locked to the housing and the ground terminal of the FPC can be conducted through the conductive support plate locked to the housing. That is, the conductive support plate having the conductive portion is locked to the housing, the ground terminal of the FPC is held in contact with the conductive portion, and the conductive cover plate is brought into contact with a part of the conductive support plate to engage with the housing. By stopping, the conductive cover plate and the ground terminal of the FPC are made conductive through the conductive support plate. That is, both the conductive support plate and the conductive covering plate are fixed by being locked to the housing by hooking, fitting, or inserting with a hook. Further, a hook-shaped conducting portion is provided on the conductive support plate, and these are brought into contact with each other by sandwiching the ground terminal of the FPC with the conducting portion. Therefore, it is possible to discharge static electricity applied through the conductive cover without using screws as before, and even when the housing is made thinner, it is possible to prevent the deterioration of the electrostatic breakdown resistance.

  Second, it is possible to sufficiently contact the ground terminal at the conducting portion without using a screw. Since the conductive support plate is made of sheet metal, it is difficult to thin the conductive support plate to such an extent that, for example, the thickness of one FPC can be sandwiched in the bending process of the hook-shaped conduction portion that sandwiches the FPC. For this reason, a folded portion where the end portion of the FPC is folded is provided, a ground terminal is provided at a position exposed on the surface of the folded portion, and the folded portion is sandwiched between the conductive portions. Since the FPC is surely brought into contact with the conducting portion by the restoring force to return from the folded state to the opened state, the contact between the ground terminal and the conducting portion is sufficient.

  3rdly, the protrusion part which protrudes inside (opposite side) is provided in one surface among two surfaces which the conduction | electrical_connection part which has a hook shape opposes. As a result, the width of the protruding portion between the opposing surfaces is thinner than other regions of the conductive portion, and the width for sandwiching the FPC can be narrowed even in thin sheet metal processing where bending is difficult. If the width | variety part which has the restoring force which it tries to open is narrow, the conduction | electrical_connection part and a grounding terminal can be made to contact reliably, since it will contact | abut with a conduction | electrical_connection part more reliably.

  4thly, by providing a grounding terminal in both surfaces which a folding | returning part exposes, it can be made to contact reliably on the inner both surfaces of a conduction | electrical_connection part.

  Fifth, the other surface of the conducting portion where the protrusion is not provided is a flat surface, and by forming a large ground terminal in contact with this, a sufficient contact area with the conducting portion can be ensured.

  Sixth, the conductive support plate is fixed to the housing by a hook-shaped fixing portion, and the conductive covering plate and the conductive support plate are fixed to the housing by contacting the fixing portion with the conductive covering plate. Both can be brought into contact without separately providing a connection region.

  Seventh, the conductive support plate is a heat dissipation plate of a laser diode driving circuit formed of a metal material having high heat dissipation, and in a thin optical pickup device, without adding new parts, It is possible to prevent deterioration of the destruction resistance.

  Eighth, since the conductive support plate (heat radiating plate) is electrically connected to the conductive cover plate with high heat dissipation, it is possible to dissipate heat even through the conductive cover plate, and the heat dissipation of the laser diode driving circuit is improved. Can be increased.

  Ninth, according to the manufacturing method of the present invention, the conductive support plate and the conductive cover plate can be fixed to the housing without using screws, and the conductive cover plate and the ground terminal can be connected.

  Thereby, even if it is an optical pick-up apparatus which has a thin housing, the manufacturing method of the optical pick-up apparatus which can conduct | electrically_connect a conductive coating board and a ground terminal, and can reduce the man-hour of screw fastening can be provided.

It is (A) schematic diagram for demonstrating the optical system of the optical pick-up apparatus of this embodiment, (B) The cross-sectional schematic diagram. BRIEF DESCRIPTION OF THE DRAWINGS (A) The perspective view of a housing for demonstrating the optical pick-up apparatus of this embodiment, (B) The whole perspective view after an assembly. It is a perspective view which shows the electroconductive support plate of the optical pick-up apparatus of this embodiment. It is a top view which shows FPC of the optical pick-up apparatus of this embodiment. It is a circuit schematic diagram for demonstrating the optical pick-up apparatus of this embodiment. It is (A) expansion perspective view for demonstrating the optical pick-up apparatus of this embodiment, (B) It is a side view. It is a perspective view which shows the top cover of the optical pick-up apparatus of this embodiment. It is a perspective view for demonstrating the optical pick-up apparatus of this embodiment. It is an expansion perspective view which shows the optical pick-up apparatus of this embodiment. It is a flowchart for demonstrating the manufacturing method of the optical pick-up apparatus of this embodiment. It is a perspective view which shows the conventional optical pick-up apparatus.

  The embodiment of the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a diagram showing an outline of an optical system of the optical pickup device 10, and FIG. 1A is a plan view. FIG. 1B is a cross-sectional view taken along the line aa in FIG.

  The optical pickup device 10 emits laser light to the information recording medium (optical disk D) and detects the laser light reflected by the optical disk D. Here, as an example, an optical pickup provided with an optical system that condenses two laser beams respectively corresponding to an optical disc D1 of DVD (Digital Versatile Disk) standard and an optical disc D2 of CD (Compact Disc) standard by one objective lens 108. The apparatus 10 will be described. The optical disc D is a general term for the optical disc D1 and the optical disc D2.

  In the optical pickup device 10, the laser diode 101, the drive circuit 115, and various optical elements are housed in the housing 11.

  Referring to FIG. 1A, a laser diode (hereinafter referred to as LD) 101 is a DVD laser diode (DVD_LD) that emits laser light having a wavelength of about 630 to 670 nm (nanometer), and a wavelength of about 770. A CD laser diode (CD_LD) that emits a laser beam of ˜805 nm is housed in one package (for example, a CAN package). DVD_LD and CD_LD may be separate LDs or may be monolithically integrated on one semiconductor substrate.

  The drive circuit 115 is a laser diode drive circuit (hereinafter, LDD 115) that supplies current to the LD 101 to drive it. The LDD 115 and the LD 101 are connected to a flexible printed circuit (FPC) 17 on which a conductive pattern 171 is formed. That is, the LDD 115 and the LD 101 are electrically connected by the conductive pattern 171. A current is supplied from the LDD 115 to the LD 101 via the FPC 17, and laser light is emitted from the LD 101. As will be described in detail later, the FPC 17 has two ground terminals (a first ground terminal 172 and a second ground terminal 173) on one main surface of the end portion. First and second ground terminals 172 and 173 are electrically connected to ground terminals of LDD 115 and LD 101 through conductive pattern 171.

  The diffraction grating 103 separates the DVD laser light and the CD laser light emitted from the LD 101 into 0th order light, + 1st order light, and −1st order light, respectively.

  For example, the half mirror 104 reflects part of the laser light and transmits part of the laser light. The half mirror 104 is formed using glass having excellent optical characteristics. Instead of the half mirror 104, for example, a beam splitter may be used.

  The collimator lens 106 converts the light incident on this lens from the half mirror 104 side into parallel light and emits it to the rising mirror 107 side. Parallel light means light that travels in parallel without any rays spreading. On the other hand, the diffused light means light from a light source that diffuses and irradiates light in various directions.

  The rising mirror 107 is provided at a position where the laser light converted into parallel light is incident, and reflects the laser light in the direction of the objective lens 108 (direction perpendicular to the signal recording surface of the optical disc D: + Df direction). .

  The light receiving element 105 is a front monitor diode that is irradiated with a part of the laser light, detects the laser light, and applies feedback for controlling the LD 101.

  The astigmatism generation optical element 110 is, for example, a sensor lens, a cylindrical lens, or an AS (astigmatism) plate, and generates astigmatism in the laser light. The laser beam in which astigmatism is generated is applied to the photodetector 111.

  The photodetector 111 receives the laser beam reflected from the optical disc, converts the signal into an electrical signal, and detects information recorded on the optical disc. The photodetector 111 is, for example, a photodiode IC (PDIC) in which a photo diode and an integrated circuit are combined.

  The photodiode constitutes a well-known quadrant sensor, etc., receives the laser beam reflected from the optical disc, converts the signal into an electrical signal, and thereby reads the signal recorded on the signal recording layer of the optical disc D I do. The electric signal includes a focus error signal generated by an astigmatism method or the like, or a tracking error signal generated by a three beam method or the like. A focusing control operation is performed by the focus error signal, and a tracking control operation is performed by the tracking error signal. Since such various signal generation methods and control operations by these methods are well known, description thereof will be omitted.

  Referring to FIG. 1B, the objective lens 108 condenses the laser light reflected by the rising mirror 107 onto the signal portion of the optical disc D. That is, the DVD laser light emitted from the LD 101 is irradiated as a focused spot on the signal recording layer provided on the DVD standard optical disc D1 by the focusing operation of the objective lens. Further, the CD laser light emitted from the LD 101 is irradiated as a condensing spot on the signal recording layer provided on the CD standard optical disc D2 by the condensing operation of the objective lens. The objective lens 108 is attached to a lens holder (not shown), and the lens holder (not shown) is supported by an actuator 109 so as to be movable.

  The actuator 109 is, for example, opposed to a lens holder (not shown) to which the objective lens 108 is attached, each coil that drives the lens holder (not shown) by electromagnetic force generated when a current is passed, and the coil. It is configured to include a magnet that always generates magnetic flux and a yoke to which the magnet is attached.

  The light collecting operation of the optical pickup device 10 is as follows.

  The laser beam output from the LD 101 passes through the diffraction grating 103, is reflected at a substantially right angle by the half mirror 104, and enters the collimator lens 106. The laser beam is reflected at a substantially right angle (Df direction) by the rising mirror 107, converged by the objective lens 108, and irradiated onto the optical disc D.

  Further, part of the laser light output from the LD 101 passes through the half mirror 104 and is irradiated to the light receiving element 105.

  The return light of the laser light reflected by the optical disk D is transmitted through the objective lens 108, the rising mirror 107, the collimator lens 106, and the half mirror 104, is transmitted through the optical element 110 for generating astigmatism, and enters the photodetector 111. Irradiated.

  Note that the optical system of the optical pickup device 10 of the present embodiment is not limited to the above. For example, one laser diode that emits laser light of three different wavelengths may be used, and an optical system that guides laser light of three wavelengths to one objective lens may be used, or three individual laser diodes may be used. It may be an optical system that leads to one objective lens or two objective lenses. Alternatively, it may be an optical system that guides only one wavelength of laser light and two wavelengths of laser light to one or two objective lenses.

  2 is a perspective view illustrating the optical pickup device 10, FIG. 2A is a perspective view showing the housing 11 before the optical element is accommodated, and FIG. 2B is an optical pickup device 10 after assembly. It is a perspective view which shows the whole.

  Referring to FIG. 2A, the housing 11 is made of a thermoplastic synthetic resin material having heat resistance and integrally formed by injection molding. As a thermoplastic synthetic resin material that can be injection-molded and has heat resistance, for example, polyphenylene sulfide resin (poly phenylene sulfide), which has excellent electrical characteristics such as thermal stability and insulation characteristics, mechanical characteristics, and dimensional stability. Adopted polyarylene sulfide resins such as PPS, polycarbonate, modified polyphenylene ether (modified-Polyphenyleneether: m-PPE), acrylonitrile (Butadiene)-styrene (Styrene) copolymer synthetic resin (ABS resin), etc. Is done. The housing 11 of this embodiment is used for the thinned optical pickup device 10 and has a thickness (thickness in the Df direction) t of, for example, about 3.5 mm.

  A plurality of concave storage areas 16 are provided in the housing 11, and various optical elements (not shown here) shown in FIG. 1 are stored in these storage areas 16.

  The conductive support plate 12 is disposed in one of the storage areas 16 so as to be in contact with the concave bottom surface. The conductive support plate 12 supports the LDD (not shown) at the LDD support portion 125. The conductive support plate 12 is locked to the housing 11 by a plurality of fixing portions 121a, 121b, and 121c provided at the end portions.

  Referring to FIG. 2 (B), actuator 109 for holding objective lens 108 movably in storage area 16, circuit board 113 provided with wirings electrically connected to various optical elements, and laser diode (Not shown) is also accommodated, and a conductive cover plate (top cover) 15 that covers a part of the housing 11 is provided on one main surface (upper surface) of the housing 11. The top cover 15 protects various optical elements from contact of workers and dust when handling the optical pickup device 10. The top cover 15 is press-molded using a thin metal plate (for example, stainless steel (SUS)) having excellent heat dissipation. The top cover 15 is locked to the housing 11 without using screws.

  Here, the term “locking” refers to a state in which one member and another member are held and fixed in combination with each other by contacting each other. Specifically, when hooks of one member are hooked and fixed to other members, insertion pieces of one member are inserted into and fixed to insertion ports of other members, or fitting of one member is performed. This refers to a case where the groove (or opening) is fitted with a protrusion of another member.

  Specifically, the conductive support plate 12 includes, for example, a hook-shaped fixing portion 121a and a groove-shaped fixing portion 121c fitted to the protrusions P1 and P2 of the housing 11, respectively, and a plug-shaped fixing portion 121b. Is inserted into the insertion slot I of the housing 11 to be fixed to the housing storage area 16 without using a screw (FIG. 2A). Further, the conductive cover plate 15 is fixed to the housing 11 by using a plurality of (for example, eight) hooks 151 provided around the conductive cover plate 15 without using screws (FIG. 2B).

  A first support portion 111 and a second support portion 112 are provided on both side ends of the housing 11. These are formed with a substantially cylindrical guide hole or a U-shaped guide groove at the center. The first support portion 111 and the second support portion 112 are respectively provided with a main guide shaft and a sub guide shaft of an optical pickup support device (so-called traverse mechanism) that drives the optical pickup device 10 in the radial direction (± Dr direction) of the optical disc. It is inserted.

  With reference to FIG. 3, the electroconductive support plate 12 of this embodiment is demonstrated. 3 is a perspective view showing the entire conductive support plate 12, FIG. 3A is a perspective view of the conductive support plate 12 shown in FIG. 2A, and FIG. It is the perspective view which looked at (A) from -Df direction.

  The conductive support plate 12 is, for example, a metal plate having a high heat dissipation property (for example, phosphor bronze or aluminum), and serves as a heat dissipation plate for the LDD 115. The conductive support plate 12 includes an LDD support part 125, a fixing part 121 (121 a, 121 b, 121 c), and a conduction part 122.

  The LDD support part 125 is a horizontal plane whose periphery is along the bottom surface of the storage area 16 of the housing 11, and the mounting part 125 c of the LDD 115 is provided in the approximate center. The mounting portion 125c includes an annular concave portion and an inner convex portion.

  A plurality of fixing parts 121 are formed at the end of the LDD support part 125 by cutting or bending. The fixing portion 121 fixes the conductive support plate 12 to the housing 11 by being engaged with a notch, an insertion port, a protrusion, a partition wall of the housing 11, or the like provided in the housing 11. In the present embodiment, as an example, a hook-shaped first fixing portion 121a, an insertion piece-shaped second fixing portion 121b, and a fitting groove-shaped third fixing portion 121c are provided.

  The first fixing portion 121a rises from the end of the LDD support portion 125 along the partition wall of the housing 11 in a direction perpendicular to the main surface of the LDD support portion 125 (+ Df direction), and is predetermined (similar to the partition wall). This is a hook shape folded back 180 degrees (in the −Df direction). Furthermore, a fitting groove T1 is provided on the outer surface of the hook shape. The first fixing portion 121a hooks the hook on the partition wall of the housing 11 and engages the fitting groove T1 with the protrusion P1 of the housing 11 to lock the conductive support plate 12 to the housing 11 (FIG. 1A). reference).

  The second fixing portion 121b extends from the main surface of the LDD support portion 125 and is larger than the storage area 16 and protrudes, for example, in a direction perpendicular to the radial direction (Dr direction) of the optical disc D (+ Dt direction). It is. The second fixing portion 121b is electrically conductive by being inserted substantially horizontally with the main surface of the LDD support portion 125 into a slit-like insertion port (see FIG. 6A, insertion port I) provided at the bottom of the housing 11. The support plate 12 is locked to the housing 11.

  The third fixing portion 121c has a shape that rises in the + Df direction along the partition from the end portion of the LDD support portion 125, and is provided with a fitting groove T2 substantially at the center. The third fixing portion 121c locks the conductive support plate 12 to the housing by fitting the projection P2 of the partition wall and the fitting groove T2 (see FIG. 1A).

  As described above, the conductive support plate 12 is fixed to the housing by the fixing portion 121 without using a screw.

  The conduction portion 122 is bent into a stepped shape that rises in the + Df direction from the main surface of the LDD support portion 125, and is provided as an upper step portion of the LDD support portion 125. The side of the conduction portion 122 extends in the + Dr direction at a predetermined position. It has a shape bent by 180 degrees (in the -Dr direction). That is, the conduction part 122 is provided at a position higher in the Df direction than the LDD support part 125 and has a hook shape that can be sandwiched in the Dr direction.

  Further, on the upper side surface (+ Df side surface) 122u of the conductive portion 122, a protruding portion 122a that protrudes inward (opposite side: -Df direction) is provided. On the other hand, the lower surface (surface on the -Df side) 122d of the conductive portion 122 facing this is flat. The conduction part 122 holds the FPC (not shown here) in its hook shape.

  The FPC 17 and the LDD 115 and LD 101 connected to the FPC 17 will be described with reference to FIGS.

  4A and 4B are plan views showing the FPC 17. FIG. 4A is a plan view of the entire FPC 17 on the first main surface Sf1 side, and FIG. 4B is a plan view of the FPC 17 on the second main surface Sf2 side. is there. 4 (C) and 4 (D) are enlarged plan views in the vicinity of the folded portion 174 in FIGS. 4 (A) and 4 (B), respectively, and FIG. 4 (E) shows the folded portion 174 folded. FIG. 4 is an enlarged plan view of the FPC 17 in the opened state on the first main surface Sf1 side, and FIG. 4F is a plan view on the back surface (second main surface Sf2) side of FIG. Further, FIG. 5 is a circuit schematic diagram showing a connection relationship between the LDD 115 and the LD 101.

  One end of the FPC 17 is branched into a substantially L shape, and a folded portion 174 is provided at one end of the substantially L shape. The folded portion 174 is exposed to the folded portion first main surface Sf11 (FIGS. 4A and 4C) exposed to the first main surface Sf1 side of the FPC 17 in the folded state, and to the second main surface Sf2 side of the FPC 17. The folded portion second main surface Sf12 (FIGS. 4B and 4D) is provided. Another FPC (hereinafter referred to as sub FPC) 17S is fixed to the folded portion 174 with solder or the like, and the LD 101 is fixed to the tip of the sub FPC 17S with solder or the like. The first connection terminal 172 is provided on the first folded main surface Sf11, and the second connection terminal 173 and the LDD 115 are fixed to the second folded main surface Sf12. A plurality of conductive patterns 171 serving as wirings are provided on the second main surface Sf2 of the FPC 17 (FIG. 4B). Although detailed illustration is omitted, the LD 101 is connected to the conductive pattern 171 of the FPC 17 via a conductive pattern (not shown) provided in the sub-FPC 17S. That is, the conductive pattern 171 is electrically connected to the external connection terminal of the LD 101 and the external connection terminal of the LDD 115, respectively. The other end of the FPC 17 is connected to the connector 116 (FIGS. 4A and 4B).

  Referring to FIG. 4E, when the folded portion 174 is opened and viewed from the first main surface Sf1 side of the FPC 17, the folded portion first main surface Sf11 and the folded portion second main surface Sf12 are exposed. The first connection terminal 172 is exposed at the end of the folded portion first main surface Sf11, and the second connection terminal 173 and the LDD 115 are exposed at the folded portion second main surface Sf12.

  The first ground terminal 172 and the second ground terminal 173 are formed in a predetermined shape with a conductive paste such as cream solder. The second ground terminal 173 is larger than the first ground terminal 172 and is provided in a rectangular shape.

  Referring to FIG. 4F, when the folded portion 174 is opened and viewed from the second main surface Sf2 side of the FPC 17, the back surface Sf13 of the folded portion first main surface Sf11 and the back surface of the folded portion second main surface Sf12. Sf14 is exposed. The sub FPC 17S is fixed to the back surface Sf13 of the folded portion first main surface Sf11 with solder or the like. The LD 101 (broken line) connected to the sub FPC 17S is disposed so as to be sandwiched between the sub FPC 17S and the second main surface Sf2 of the FPC 17 in FIG.

  The folded portion 174 is mountain-folded at a fold line 174LA shown in FIG. 4E (in FIG. 4F, valley-folded at a fold line 174LB). That is, it is folded back 180 degrees so that the back surface Sf13 of the folded portion first main surface Sf11 and the back surface Sf14 of the folded portion second main surface Sf12 are inside, and the folded portion first main surface as shown in FIGS. The surface Sf11 and the folded portion second main surface Sf12 are exposed on both surfaces.

  4A, 4C, and 4E, when the FPC 17 is viewed from the first main surface Sf1 side, the sub FPC 17S (broken line) is disposed below the FPC 17, and the LD 101 (broken line) It arrange | positions between sub FPC17S. 4B, 4D, and 4F, when the FPC 17 is viewed from the second main surface Sf2 side, the sub FPC 17S is disposed above the FPC 17, and the LD 101 (broken line) It arrange | positions between FPC17S.

  Referring to FIGS. 5 and 1A, first ground terminal 172 and second ground terminal 173 are both connected to external ground terminal LDD_GND among the external connection terminals of LDD 115. Specifically, the LD 101 includes a DVD_LD 101d and a CD_LD 101c, and these cathodes are derived as external ground terminals LD_GND. The externally installed terminal LD_GND of the LD 101 is connected to the external connection terminal of the LDD 115 via the conductive pattern 171 of the FPC 17, and the external ground terminal LDD_GND of the LDD 115 is connected to the first ground terminal 172 and the second ground terminal 173 via the conductive pattern 171. To do.

  The shape of the FPC 17 and the arrangement and connection of the LDD 115 and the LD 101 on the FPC 17 are merely examples, and are not limited to those illustrated. In the present embodiment, the folded portion 174 may be provided at the end of the FPC 17, and the ground terminal may be provided on at least one surface of the folded portion 174. For example, the first ground terminal 172 and the second ground terminal 173 may be provided on one surface (for example, the folded portion first main surface Sf11) side of the folded portion 174, or one ground terminal may be provided. . However, it is desirable to provide the first ground terminal 172 and the second ground terminal 173 on both surfaces (Sf11, Sf12) of the folded portion 174, respectively, which will be described later.

  With reference to FIG. 6, the contact between the first ground terminal 172 and the second ground terminal 173 and the conductive portion 122 of the conductive support plate 12 will be described.

  6A and 6B are views showing a part of the conductive support plate 12 and the FPC 17 after assembly. FIG. 6A is a perspective view of the conductive portion 122 that sandwiches the FPC 17, and FIG. 6B shows the LDD 115. It is a figure which shows the electroconductive support plate 12 to support, and is the side view which looked at FIG. 6 (A) from the -Dr direction.

  The conductive support plate 12 is engaged with the protrusions (not shown) of the housing 11 by fitting the fixing portions 121 a and 121 c, and the fixing portion 121 b is inserted into the insertion port I of the housing 11 and locked to the housing 11.

  The mounting portion 125c of the conductive support plate 12 stores a heat dissipation agent (not shown), and the LDD 115 is disposed thereon. Heat generated by driving the LDD 115 is radiated to the outside through the heat radiating agent and the conductive support plate 12.

  Each external connection terminal (including the external ground terminal LDD_GND) of the LDD 15 is connected to a conductive pattern (not shown) of the FPC 17. A folded portion 174 is provided at the end of the FPC 17 so that the first ground terminal 172 and the second ground terminal 173 are exposed on both surfaces. The folded portion 174 is inserted in the Dr direction into the hook-shaped conducting portion 122 hook, and is thereby sandwiched.

  The first ground terminal 172 and the second ground terminal 173 of the FPC 17 are in contact with the conductive portion 122 of the conductive support plate 12 by sandwiching the folded portion 174 with the conductive portion 122.

  That is, the first ground terminal 172 and the second ground terminal 173 are exposed on the two surfaces of the folded portion 174 (the folded portion first main surface Sf11 and the folded portion second main surface Sf12), respectively, and the inner wall of the conducting portion 122 is exposed. Contact with. The protrusion 122a contacts the first ground terminal 172 on the upper side 122u of the conductive part 122, and the flat surface of the inner wall contacts the second ground terminal 173 on the lower side 122d.

  Since the conductive support plate 12 is processed by sheet metal, the thickness (distance between the upper side surface 122u and the lower side surface 122d) t1 of the hook-shaped conductive portion 122 sandwiching the FPC 17 is set to, for example, the thickness of one FPC 17 It is difficult to bend thinly to such an extent that can be sandwiched. Therefore, the folded portion 174 is provided at the end of the FPC 17, the first ground terminal 172 and the second ground terminal 173 are provided on the two exposed surfaces of the folded portion 174, and the folded portion 174 is sandwiched between the conductive portions 122. The FPC 17 is elastically deformed in a folded (folded) state, and a contact pressure against the inner wall of the conducting portion 122 is obtained by a restoring force for returning to the opened state. That is, the conduction part 122 can be reliably brought into contact with the first ground terminal 172 and the second ground terminal 173.

  Furthermore, by providing the projecting portion 122a on the conducting portion 122, the thickness t2 between the opposing surfaces of the projecting portion 122a becomes thinner than the thickness t1 of the other region of the conducting portion 122, which is a sheet metal working that is difficult to bend thinly. Also, the thickness for sandwiching the FPC 17 can be reduced. If the thickness of the folded portion 174 is small, the folded portion 174 is more reliably brought into contact with the conducting portion 122, so that the conducting portion 122 can be reliably brought into contact with the first ground terminal 172 and the second ground terminal 173.

  The protrusion 122a is provided in a semi-cylindrical shape or a semicircular shape, and a contact area with the conduction portion 122 (upper side surface 122u) is reduced. For this reason, the second ground terminal 173 is provided not only on the folded-back first main surface Sf11 but also on the folded-back second main surface Sf12. The second ground terminal 173 has a rectangular shape, for example, having a larger area than the first ground terminal 172 (see FIG. 4E), and the lower surface 122d of the conductive portion 122 is a flat surface. Thereby, a sufficient contact area between the second ground terminal 173 and the conductive portion 122 can be ensured.

  Note that the height at which the conductive portion 122 protrudes from the main surface of the LDD support portion 125 is, for example, approximately the same as the thickness of the LDD 115 (FIG. 6B). Further, a part of the FPC 17 is accommodated in the housing 11 by being folded into a desired shape on the main surface of the housing 11.

  Next, the connection between the top cover 15 and the ground terminals 172 and 173 of the FPC 17 will be described with reference to FIGS.

  FIG. 7 is a perspective view showing the top cover 15 of the present embodiment, FIG. 7A is a perspective view of the top cover 15 on the upper surface side, and FIG. 7B is a view from the back surface (−Df direction). FIG.

  A plurality of (for example, eight) hooks 151 (151a to 151h) are formed around the top cover 15. The hooks 151 do not have to have the same shape, and each has a shape that can be locked with the housing 11. For example, the hook 151a is bent substantially vertically from the main surface of the housing 11 along the side surface (partition wall) of the housing 11, and the opening O is provided on the surface along the side surface (partition wall). The opening O may be a notch in which at least one end of the hook 151a is cut out, or may be formed by hollowing out substantially the center so as to leave the end of the hook 151a in a ring shape. The opening O is fitted to a protrusion (not shown here) provided on the side surface (partition wall) of the housing 11 at a position corresponding to the opening O.

  Further, the hook 151 may be provided in a U-shape (U-shape) (151b, 151c, 151e, 151f) or a substantially L-shape (151g, 151h), and the partition wall of the housing 11 or a part thereof is formed in the thickness. It is fixed by sandwiching it in the direction or by inserting it into the protrusion of the housing 11.

  FIG. 8 is a perspective view showing the FPC 17 and the top cover 15 attached to the housing 11. FIG. 8A is a perspective view with the FPC 17 attached, and FIG. 8B is a perspective view with the top cover 15 attached. Note that illustration of optical elements, actuators, and the like housed in the housing area 16 is omitted here. FIG. 9 is an enlarged perspective view of the first fixing portion 121a portion of FIG. FIG. 9A is a perspective view of FIG. 8B viewed from the Dr direction. FIG. 9B is a plan view of the housing 11 of FIG. FIG. 6 is a perspective view showing a state of contact of a cover 15. FIG. 9C is a perspective view seen from the direction of the arrow in FIG.

  First, in FIG. 8A, the conductive support plate 12 is fixed in advance by hooking the hook-shaped first fixing portion 121a to the partition wall of the housing 11 (see FIG. 1A). The first fixing portion 121a further has a hook-shaped outer fitting groove T1 fitted into the protrusion P1 of the housing.

  A part of the FPC 17 is accommodated in the housing 11 by inserting the protrusion P3 of the housing 11 into the mounting hole H and folding the FPC 17 into a desired shape on the main surface of the housing 11. An LDD 115 is fixed to the FPC 17, and the LDD 15 is placed on a mounting portion (not shown here) of the conductive support material 12 in which a heat dissipating material is stored (see FIG. 6B).

  Thereafter, the top cover 15 is locked to the housing 11 as shown in FIG. The top cover 15 is fixed to the housing 11 by a plurality of hooks 151a to 151h without using screws.

  Referring to FIG. 9, hook 151 a is provided at a position overlapping with first fixing portion 121 a of conductive support plate 12. The conductive support plate 12 is fixed by hooking a hook-shaped first fixing portion 121a to the partition wall of the housing 11, and a part of the first fixing portion 121a is exposed to the partition wall. The hook 151a is attached to the housing 11 so as to cover the first fixing portion 121a. The protrusion P1 of the housing 11 further protrudes from the first fixing portion 121a, and the opening O of the hook 151a and the protrusion P1 of the housing 11 are fitted.

  That is, by fixing the top cover 15 to the housing 11, the hook 151a of the top cover 15 and the first fixing portion 121a come into contact with each other (FIGS. 9B and 9C).

  Thus, at least one of the fixing portions 121 (here, the first fixing portion 121a) serves as a contact portion with the top cover 15. Therefore, it is desirable that the first fixing portion 121a has a shape that can sufficiently ensure a contact area with the top cover 15. That is, the first fixing portion 121a is not limited to the hook shape, but is provided in a shape along the partition wall of the housing 11 so as to be substantially perpendicular to the main surface of the LDD support portion 125. A contact area with the top cover 15 can be secured on the partition wall surface without securing a separate contact area.

  In this way, the top cover 15 is electrically connected to the first ground terminal 172 and the second ground terminal 173 of the FPC 17 via the first fixing portion 121a and the conductive portion 122 of the conductive support plate 12 (FIG. 6 ( B)). That is, the top cover 15 can be grounded without using screws, and static electricity applied to the top cover 15 can be discharged.

  In addition, since the conductive support plate 12 that is a heat radiating plate of the LDD 115 is electrically connected to the top cover 15, heat generated in the LDD 115 can be radiated through the top cover 15 and heat dissipation can be improved.

  When the conductive support plate 12 is entirely conductive, the top cover 15 and the conductive support plate 12 can be electrically connected if the top cover 15 is in contact with any region of the conductive support plate 12. is there. That is, in the above example, the case in which the first fixing portion 121a and the hook 151 (151a) of the top cover 15 are brought into contact with each other has been described as an example. However, since both the conductive support plate 12 and the top cover 15 are engaged with the housing 11, it is necessary to secure different contact areas by overlapping the hooks which are the engaging means and contacting them. Has the advantage of eliminating.

  In this embodiment, the top cover 15 contacts the first fixing portion 121 a of the conductive support plate 12, and the conduction portion 122 contacts the first ground terminal 172 and the second ground terminal 173 of the FPC 17. However, the top cover 15 is not limited to the above embodiment, for example, the top cover 15 may be used as long as the top cover 15 is electrically connected to the ground terminal via the conductive support plate 12. The part and the conducting part 122 may be in direct contact with each other.

  In the above embodiment, another FPC 17 ′ connected to an actuator (not shown) is disposed between the top cover 15 and the conductive portion 122 (FIG. 8A). Therefore, although the top cover 15 extends above the conducting portion 122 (see FIG. 8), the top cover 15 and the conducting portion 122 are not completely contacted by being insulated by another FPC 17 '. That is, the conductive support plate 12 electrically connects the top cover 15 with the first ground terminal 172 and the second ground terminal 173 at two locations, the first fixing portion 121a and the conducting portion 122.

  However, the conductive support plate 12 can also directly conduct the top cover 15 and the ground terminal at one place (conduction portion 122). For example, if the shape of the other FPC 17 ′ and the shape and position of the FPC 17 ′ stored by being folded below the top cover 15 are devised so that the other FPC 17 ′ is not disposed on the conduction portion 122, the conduction portion 122. The top cover 15 can be directly contacted. In this case, the top cover 15 and the ground terminal can be conducted at one place of the conducting portion 122 in plan view.

  Furthermore, if the 1st fixing | fixed part 121a of the electroconductive support plate 12 of this embodiment latches and is fixed to the housing 11, the shape will not be restricted to a hook shape. For example, a fitting groove shape is formed as in the third fixing portion 121c, and the conductive support plate 12 is fixed by being engaged with the protrusion of the partition wall of the housing 11, and the top cover 15 is placed inside the first fixing portion 121a (inner wall of the storage area). The hook 151 may be brought into contact to be conducted.

  The conductive support plate 12 is not limited to a sheet metal as long as the heat dissipation is good and the first fixing portion 121a and the conduction portion 122 are electrically connected. For example, the first fixing portion and the conductive portion may be covered with a metal by printing or the like using ceramic or resin having good heat dissipation, and a conductive pattern for connecting them may be formed. However, considering that it is lightweight, excellent in workability, and inexpensive, a sheet metal is preferable.

  The manufacturing method of the optical pickup device 10 of the present embodiment will be described with reference to the flowchart of FIG.

  First, the optical pickup device 10 collectively mounts electronic components such as the LDD 115 (excluding the LD 101) on the FPC 17 shown in FIG. 4 (step S1). As described above, the FPC 17 is provided with the conductive pattern 171, the first ground terminal 172, and the second ground terminal 173, and this is connected to the external ground terminal LDD_GND of the LDD 115.

  Next, a plurality of optical elements and the like shown in FIG. 1 are fixed to the storage area 16 of the housing 11 (see FIG. 2) integrally molded with a resin material (step S2).

  Thereafter, the LD 101 is fixed to the sub FPC 17S of the FPC 17 with solder or the like (step S3): see FIG. Accordingly, the LD 101 is electrically connected to the conductive pattern 171 of the FPC 17 via the sub FPC 17S, and is connected to the LDD 115.

  Next, the conductive support plate 12 is locked to one of the storage areas 16 of the housing 11 (step S4). The conductive support plate 12 inserts the second fixing portion 121b into the insertion slot, hooks the hook of the first fixing portion 121a to the partition wall of the housing 11, and makes the fitting groove T of the third fixing portion 121c the protrusion P2 of the housing 11. And is engaged with the housing 11. The conductive support plate 12 is fixed to the housing 11 without using screws.

  Thereafter, the FPC 17 is attached to the housing 11. A circuit board 113 on which a predetermined pattern is formed is fixed to the housing 11, and then the LD 101 and LDD 115 are housed in the housing 11 together with the FPC 17. The LDD 115 is placed on the mounting portion 125c in which the heat dissipating material is stored (FIG. 6B). LD 101, light receiving element 105, and LDD 115 are connected to circuit board 113.

  The FPC 17 is folded back so that the first ground terminal 172 and the second ground terminal 173 provided at one end are exposed to be a folded portion 174, and the folded portion 174 is sandwiched between the conducting portions 122 (step S5). The first ground terminal 172 and the second ground terminal 173 come into contact with the inner wall of the conductive portion 122 by the restoring force of the FPC 17 that is bent and elastically deformed (FIG. 6).

  A part of the FPC 17 is accommodated in the housing 11 by inserting the protrusion P3 of the housing 11 into the mounting hole H and folding the FPC 17 into a desired shape on the main surface of the housing 11. Thereafter, the top cover 15 is locked to the housing 11. The top cover 15 is fixed to the housing 11 by a plurality of hooks 151 without using screws.

  In addition, an actuator 109 (see FIG. 1B) that is separately assembled and supports the objective lens 108 in a movable state is attached to the storage area 16 of the housing 11. Thereafter, the positions of optical elements such as the PDIC 111 and the rising mirror 107 are confirmed.

  Thereafter, the hook 151 of the top cover 15 is locked to the housing 11. At this time, the first fixing portion 121a is covered with the hook 151a of the top cover 15 and comes into contact therewith.

  As a result, the top cover 15 and the first ground terminal 172 and the second ground terminal 173 of the FPC 17 are conducted through the conducting portion 122 (step S6). In this way, the optical pickup device 10 shown in FIG. 1 is manufactured.

  Further, both the main guide shaft and the sub guide shaft guide shaft are inserted into the first support portion 111 and the second support portion 112 of the housing 11 shown in FIG. The optical pickup support device is configured by supporting the part with a frame-shaped chassis. Furthermore, the optical pickup device is configured by incorporating the optical pickup supporting device having such a configuration in a housing.

DESCRIPTION OF SYMBOLS 10 Optical pick-up apparatus 11 Housing 12 Conductive support plate 121 Fixed part 121a 1st fixed part 121b 2nd fixed part 121c 3rd fixed part 122 Conductive part 15 Conductive coating | cover board 151, 151a, 151b, 151c, 151d Hook 151e, 151f 151g, 151h Hook 17 FPC
171 Conductive pattern 172 First ground terminal 173 Second ground terminal 101 LD
103 Diffraction grating 104 Half mirror 105 Light receiving element 106 Collimator lens 107 Rising mirror 108 Objective lens 109 Actuator 110 Astigmatism generating optical element 111 Photo detector 113 Circuit board 115 Laser diode drive circuit

Claims (14)

An optical pickup device that emits laser light to an information recording medium and detects the laser light reflected by the information recording medium,
A housing in which an optical element is housed;
A laser diode housed in the housing and irradiating the laser beam;
A conductive support plate locked in the housing;
A laser diode driving circuit provided on the conductive support plate;
A flexible wiring board formed with a conductive pattern electrically connected to the laser diode driving circuit and a ground terminal of the laser diode driving circuit;
A conductive covering plate covering a part of one main surface of the housing and locked to the housing;
Comprising
The conductive support plate has a conductive portion, the ground terminal is held in contact with the conductive portion, and the ground terminal and the conductive cover plate are electrically connected via the conductive support plate. Optical pickup device.   The optical pickup device according to claim 1, wherein the conducting portion has a hook shape, and the conducting portion sandwiches the ground terminal.   The optical pickup device according to claim 1, wherein the flexible substrate is provided with a folded portion at an end portion, and the ground terminal is exposed on a surface of the folded portion.   4. The optical pickup device according to claim 1, wherein the conductive portion is provided with a protruding portion, and the protruding portion is in contact with the connection terminal. 5.   5. The optical pickup device according to claim 3, wherein another connection terminal is exposed on the other surface of the folded portion.   The optical pickup device according to claim 5, wherein the conducting portion in contact with the other connection terminal is a substantially flat surface.   7. The optical pickup according to claim 1, wherein the conductive support plate is fixed to the housing by a hook-shaped fixing portion, and the conductive covering plate is in contact with the fixing portion. apparatus.   The optical pickup device according to claim 1, wherein the conductive support plate is a metal plate.   The optical pickup device according to claim 8, wherein the conductive support plate is a heat radiating plate of the laser diode driving circuit.   The optical pickup device according to claim 1, wherein the conductive cover plate is fixed to the housing by a plurality of hooks. A method of manufacturing an optical pickup device that emits laser light to an information recording medium and detects the laser light reflected by the information recording medium,
A step of fixing a laser diode driving circuit to a flexible wiring board provided with a conductive pattern and a grounding terminal and connecting the grounding terminal;
Storing the optical element in the housing;
Electrically connecting a laser diode to the flexible wiring board;
Locking the conductive support plate having a conductive portion in the housing;
The laser diode driving circuit is disposed on the conductive support plate, one end of the flexible wiring board is sandwiched between the conductive portions, and the ground terminal is brought into contact with the conductive portion, thereby the laser diode driving circuit and the Storing a laser diode in the housing;
A conductive covering plate covering a part of one main surface of the housing is brought into contact with a part of the conductive support plate and locked to the housing, and the conductive cover plate is interposed via the conductive support plate. Conducting the ground terminal; and
An optical pickup device manufacturing method comprising:   12. The method of manufacturing an optical pickup device according to claim 11, wherein one end of the flexible wiring board is folded to expose the ground terminal on the surface and sandwiched between the hook-shaped conducting portions.   The method of manufacturing an optical pickup device according to claim 11, wherein the conductive support plate is fixed to the housing by a hook-shaped fixing portion.   The method of manufacturing an optical pickup device according to claim 11, wherein the conductive cover plate is fixed to the housing by a plurality of hooks.

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