JP4324513B2 - Optical pickup - Google Patents

Description

  The present invention relates to an optical pickup for recording / reproducing information with respect to a disc such as a CD (compact disc) or a DVD (digital versatile disc), and in particular, a lens holder having an objective lens via a conductive wire. In particular, the present invention relates to a moving coil type optical pickup that is supported.

  An optical pickup generally drives a light receiving / emitting unit in which a light emitting means such as a semiconductor laser and a light receiving means such as a photodetector are integrally disposed, a lens holder to which an objective lens is attached, and the lens holder. An actuator provided with electromagnetic driving means, an upper cover containing the actuator with the objective lens exposed, a reflection mirror installed in an optical path between the light emitting / receiving unit and the objective lens, and each of these members It is roughly configured with a mounted chassis. In a moving coil type optical pickup, a lens holder around which a focus coil and a tracking coil are wound is supported on a substrate via a conductive wire connected to the coil, and the objective lens is corrected. The lens holder is sometimes driven in the focus direction or the tracking direction by a drive current supplied to the wire via the substrate.

  This type of optical pickup is used by being incorporated in a disk player such as a CD player, and a light beam emitted from a semiconductor laser or the like and reflected by a reflecting mirror is condensed on the recording surface of the disk by an objective lens. The return light beam from the disk is received by the light receiving means via the objective lens and the reflection mirror.

  FIG. 5 is an exploded perspective view showing a conventional example of such a moving coil type optical pickup, FIG. 6 is a plan view of an actuator provided in the optical pickup, and FIG. 7 is a sectional view of the actuator (for example, Patent Documents). 1). The conventional optical pickup shown in these drawings includes a chassis 1 made of a metal material such as aluminum, and an actuator 2 made up of an objective lens 3, a lens holder 4, a wire 5, a substrate support member 6, a magnet 7, a base member 8, and the like. And an upper cover 9 having an opening 9a for exposing the objective lens 3 and enclosing the actuator 2, and a light emitting / receiving unit (hologram) fixed to one side of the chassis 1 by unitizing the semiconductor laser and the photodetector. Unit) 10 and a reflecting mirror 11 installed in the optical path between the light emitting / receiving unit 10 and the objective lens 3.

  The chassis 1 is reciprocated in the radial direction of the disk along a guide shaft (not shown), and a reflection mirror 11 is fixed at a substantially central position of the bottom plate portion of the chassis 1 at an attachment angle of 45 degrees. The light emitting / receiving unit 10 is incorporated in the opening 1a of the chassis 1 facing the reflecting mirror 11, and the back side of the light emitting / receiving unit 10 is covered with a sheet metal heat radiation cover 12. Each terminal of the light receiving / emitting unit 10 is connected to a reinforcing portion attached to the support plate 14 of the flexible wiring board 13, and the light receiving / emitting unit is connected via a wiring pattern formed on the flexible wiring board 13. 10 is electrically connected to a signal processing circuit (not shown). The heat radiating cover 12 is fixed to one side of the chassis 1 with fixing screws 15, and the reinforcing portion of the flexible wiring board 13 is sandwiched between the heat radiating cover 12 and the side wall of the chassis 1. . The light beam emitted from the light emitting / receiving unit 10 is reflected in the vertical direction by the reflecting mirror 11 through the opening 1a, and the return light beam is reflected in the horizontal direction by the reflecting mirror 11, and then passes through the opening 1a. Light is received by the light receiving / emitting unit 10.

  The actuator 2 includes a lens holder 4 to which an objective lens 3 is attached and coils (not shown) (a focus coil and a tracking coil) are wound, and a plurality of conductive members that elastically support the lens holder 4. The surface of the substrate support member 6 on the side opposite to the lens holder 4 is formed by forming a wire 5, a substrate support member 6 through which the proximal end side of each wire 5 is inserted, and a land portion for connecting the proximal end portion of each wire 5. And a base member 8 also serving as a yoke on which the substrate support member 6 and the magnet support member 17 are mounted and fixed. The objective lens 3 is located immediately above the reflecting mirror 11. Each wire 5 has one end portion (free end portion) soldered to the coil, and the other end portion (base end portion) penetrates the back substrate 16 and is soldered to the land portion. Since the substrate 16 is electrically connected to a drive control circuit (not shown), a drive current is supplied to the focus coil and the tracking coil via each wire 5. The magnet 7 generates a magnetic flux in a direction crossing the direction of the current flowing through the coil, and the coil, the magnet 7, the base member 8 and the like constitute an electromagnetic drive means. The lens holder 4 is driven in the focus direction and tracking direction of the disk by the drive current supplied to the wire 5 during the correction operation of the objective lens 3.

The actuator 2 is placed on the bottom plate portion of the chassis 1, and a mounting screw 19 inserted through the coil spring 18 is screwed into the chassis 1 from above the base member 8, and two adjusting screws 20 are placed below the chassis 1. Then, the base member 8 is fixed to the chassis 1 in a state where the optical axis of the objective lens 3 is adjusted. In other words, in order to accurately record / reproduce signals with respect to the recording surface of the disc, the optical axis of the objective lens 3 positioned immediately above the reflecting mirror 11 is set perpendicular to the recording surface of the disc. Therefore, when the actuator 2 is mounted on the chassis 1, the optical axis of the objective lens 3 can be adjusted by adjusting the tightening force of the adjusting screw 20.
JP 2001-319342 A (page 2-3, FIG. 9)

  By the way, for this type of optical pickup, there is a strong demand for downsizing by reducing the planar size to make it compact, but in the case of the above-described conventional structure, one end side in the longitudinal direction of the chassis 1. Each of the wires needs to have a certain optical path length between the light emitting / receiving unit 10 and the reflecting mirror 11 disposed on the front side, and extends from the lens holder 4 to the other end in the longitudinal direction of the chassis 1 and penetrates the back substrate 16. 5 requires a predetermined length suitable for elastic support of the lens holder 4, which inevitably increases the longitudinal dimension of the chassis 1 and makes it difficult to achieve a desired size reduction.

  The present invention has been made in view of the actual situation of the prior art, and an object of the present invention is to provide a compact optical pickup that can promote downsizing without complicating the configuration.

  In the present invention, the wire between the lens holder and the support substrate and the optical path of the light beam between the light emitting / receiving unit and the reflecting mirror are separated in the optical axis direction of the objective lens and are the same as viewed from the center of the objective lens. Extend in the direction. That is, a component layout in which a light emitting / receiving unit, its flexible wiring board, a supporting plate, etc. are arranged on one side of a chassis where a supporting board that elastically supports a lens holder via a wire is arranged. I made it.

In the optical pickup according to the present invention, the wire between the lens holder and the support substrate and the optical path of the light beam between the light emitting / receiving unit and the reflection mirror are separated in the optical axis direction of the objective lens and the center of the objective lens. Since the component layout extends in the same direction as viewed from the front, a certain optical path length is secured between the light emitting / receiving unit and the reflecting mirror, and the predetermined length of the wire is secured, while the longitudinal dimension of the chassis is greatly shortened. be able to. Therefore, it is possible to provide a compact optical pickup that can be reduced in size without complicating the configuration. In addition, since the tip of the base end of the wire protruding from the land portion of the support substrate to the support plate side can be overlapped with the support plate while preventing interference between the two, the longitudinal dimension of the chassis can be further shortened. it can.

The present invention includes a lens holder to which an objective lens is attached, a support substrate that elastically supports the lens holder via a conductive wire, light emitting means for emitting a light beam to a disk via the objective lens, and A light receiving / emitting unit provided with light receiving means for receiving a return light beam from the disk, a flexible wiring board having a wiring pattern to which the light receiving / emitting unit is connected, and an optical axis of the objective lens, A reflection mirror that reflects the light beam emitted from the light emitting means toward the objective lens and reflects the return light beam from the disk toward the light receiving means; the support substrate; the light receiving and emitting unit; and the reflection mirror. An optical pickup comprising a mounted chassis, wherein the wire between the lens holder and the support substrate , The optical path of the light beam between the reflecting mirror and the light receiving and emitting unit, the extending in the same direction viewed from the center of and the objective lens away in the direction of the optical axis of the objective lens, anti of the support substrate The surface on the lens holder side is provided with a land portion to which the base end portion of the wire is soldered, and the base end portion of the wire penetrates the support substrate and extends to the anti-lens holder side. A support plate for attaching and supporting the substrate is disposed to face the surface of the support substrate on the side opposite to the lens holder, and the distal end of the base end of the wire is inserted into a relief portion formed on the support plate . The configuration.

In this way, the component layout is such that the light emitting / receiving unit is disposed in a planar manner on one side of the chassis where the support substrate that elastically supports the lens holder via the wire is disposed. Adopting it makes it possible to greatly reduce the longitudinal dimension of the chassis while ensuring a certain optical path length between the light emitting / receiving unit and the reflecting mirror and ensuring a predetermined length for the wire, which complicates the configuration. Therefore, the downsizing of the optical pickup can be easily promoted. In the above configuration, the surface of the support substrate on the side opposite to the lens holder is provided with a land portion to which the base end portion of the wire is soldered. The base end portion of the wire penetrates the support substrate and is on the side opposite to the lens holder. A support plate that sticks and supports the flexible wiring board is disposed so as to face the surface of the support substrate on the side opposite to the lens holder, and the distal end of the proximal end of the wire is formed in a relief portion formed on the support plate. It is preferably inserted. In addition, since the tip of the base end of the wire protruding from the land portion of the support substrate to the support plate side can be overlapped with the support plate while preventing interference between the two, the longitudinal dimension of the chassis can be further shortened. it can.

  In the above configuration, the support substrate is attached to the surface of the substrate support member on the side opposite to the lens holder and mounted on the chassis via the substrate support member, and the optical path of the light beam between the light emitting / receiving unit and the reflection mirror It is preferable that the light emitting / receiving unit is attached to the side surface of the chassis so that is formed between the inner bottom surface of the chassis and the substrate support member.

Further, the above configuration odor Te, supported Jiban is preferably made from a good metallic material having superior thermal conductivity, thereby, can be effectively radiated by using the supporting plate heat generated from the light receiving and emitting unit It becomes.

  An embodiment will be described with reference to the drawings. FIG. 1 is a sectional view taken along the longitudinal direction (tangential direction) of a moving coil type optical pickup according to an embodiment of the present invention, and FIG. 2 is an exploded view of the optical pickup. FIG. 3 is a perspective view, FIG. 3 is a plan view of the optical pickup, and FIG. 4 is a side view showing one side portion of the optical pickup. However, the upper cover is not shown in these drawings. In these figures, the same reference numerals are given to the portions corresponding to those in FIGS.

  The optical pickup shown in FIGS. 1 to 4 includes a chassis 1 made of a metal material such as aluminum or a synthetic resin material, an objective lens 3, a lens holder 4, a wire 5, a substrate support member 6, and a back substrate (support substrate) 16. , An actuator 2 comprising a magnet 7, a base member 8 and the like, an upper cover (not shown) having an opening for exposing the objective lens 3 and enclosing the actuator 2, a semiconductor laser and a photodetector as a unit. A light receiving / emitting unit (hologram unit) 10 fixed to one side of the substrate, a flexible wiring board 13 supported by a support plate 14 in the vicinity of the light receiving / emitting unit 10, and an optical path between the light emitting / receiving unit 10 and the objective lens 3. And the reflecting mirror 11 installed in the main body. As is apparent from FIG. 1, this optical pickup includes the rear substrate 16 and the substrate support member 6 to which the rear substrate 16 is attached, the light emitting / receiving unit 10, the flexible wiring substrate 13, the support plate 14 and the like all in the chassis 1. The point which is gathered in one side of the longitudinal direction (tangential direction) is greatly different from the conventional example shown in FIGS.

  The chassis 1 is reciprocated in the radial direction of the disk along a guide shaft (not shown), and a reflection mirror 11 is fixed at a substantially central position of the bottom plate portion of the chassis 1 at an attachment angle of 45 degrees. The light emitting / receiving unit 10 is positioned and incorporated in the opening 1 a of the chassis 1 facing the reflection mirror 11, and is disposed at a height position between the inner bottom surface of the chassis 1 and the substrate support member 6 and the support plate 14. ing. Each terminal 10a of the light receiving / emitting unit 10 is connected to a land 13a of the flexible wiring board 13 by soldering, and the light receiving / emitting unit 10 receives a signal (not shown) via a wiring pattern formed on the flexible wiring board 13. It is electrically connected to the processing circuit. The flexible wiring board 13 is reinforced by being attached to one side of the support plate 14 (the surface opposite to the chassis 1), and the cutout portions 21 of the flexible wiring board 13 and the support plate 14 (see FIG. 2). The flexible circuit board 13 and the support plate 14 are fixed to one side of the chassis 1 by a fixing screw 15. Since the support plate 14 is made of a metal plate with good thermal conductivity such as aluminum, the heat generated from the light emitting / receiving unit 10 can be effectively radiated using the support plate 14.

  The actuator 2 includes a lens holder 4 to which an objective lens 3 is attached and coils (not shown) (a focus coil and a tracking coil) are wound, and a plurality of conductive members for elastically supporting the lens holder 4. A land portion for connecting the wire 5, the substrate support member 6 having through holes 6 c and 6 d through which the base end side of each wire 5 is inserted and filled with a gel-like damper material, and the base end portion of each wire 5 And a rear substrate 16 fixed to the surface of the substrate support member 6 on the side opposite to the lens holder 4 and a pair of magnets 7 are attached to serve as a yoke and the substrate support member 6 is mounted and fixed. And a base member 8 made of sheet metal. The objective lens 3 is positioned directly above the reflecting mirror 11, and the substrate support member 6 has a protruding portion 6 a that fixes the rear substrate 16 positioned above the tip of the light emitting / receiving unit 10. Each wire 5 has one end portion (free end portion) soldered to the coil, and the other end portion (base end portion) penetrates the back substrate 16 and is soldered to the land portion. Since the substrate 16 is electrically connected to a drive control circuit (not shown), a drive current is supplied to the focus coil and the tracking coil via each wire 5. Note that reference numeral 16 a in the drawing indicates solder applied to the land portion of the back substrate 16. The magnet 7 generates a magnetic flux in a direction crossing the direction of the current flowing through the coil, and the coil, the magnet 7, the base member 8, and the like constitute electromagnetic driving means. The lens holder 4 is driven in the focus direction and tracking direction of the disk by the drive current supplied to the wire 5 during the correction operation of the objective lens 3.

  The support plate 14 is disposed at a position facing the land forming surface of the back substrate 16, and the flexible wiring substrate 13 for connecting the light receiving and emitting unit 10 is attached to the surface of the support plate 14 on the side opposite to the back substrate 16. Has been. As shown in FIGS. 1 and 3, relief holes (or notches) 14 a for inserting the base end portions of the wires 5 are formed at a plurality of locations on the support plate 14. That is, the base end portion of the wire 5 protruding from the land portion of the back substrate 16 to the support plate 14 side is inserted partway through the escape hole 14a, and thus the base end portion of the wire 5 is overlaid with the support plate 14. If wrapped, the support plate 14 can be disposed at a position close to the back substrate 16 side while avoiding interference with the wire 5. In addition, since the dimension is set so that the proximal end portion of the wire 5 is inserted partway through the escape hole 14a, the flexible wiring board 13 does not need to be provided with a through hole for allowing the wire 5 to escape. The area for pattern routing of the flexible wiring board 13 does not decrease, and there is no concern that the degree of freedom in design is impaired.

  As described above, in the optical pickup according to the present embodiment, the wire 5 bridged between the lens holder 4 and the back substrate 16 and the optical path of the light beam between the light emitting / receiving unit 10 and the reflecting mirror 11 are provided. The rear substrate 16 is arranged so as to be separated in the optical axis direction of the objective lens 3 and extend in the same direction as viewed from the center of the objective lens 3, and elastically supporting the lens holder 4 via the wire 5. In the longitudinal direction (tangential direction) side portion of the installed chassis 1, the light emitting / receiving unit 10, its flexible wiring board 13, the support plate 14, and the like are arranged in a concentrated manner. Accordingly, a certain optical path length is ensured between the light emitting / receiving unit 10 and the reflecting mirror 11 in a region on one side in the tangential direction from the center of the objective lens 3, and the lens holder 4 can be elastically moved to the wire 5. A predetermined length for supporting can be secured, and all or most of the effective length of the wire 5 is within the range of the optical path length between the light emitting / receiving unit 10 and the reflecting mirror 11 in the tangential direction. Since it can be arranged, the longitudinal dimension of the chassis 1 is significantly shortened compared to the conventional example.

  In addition, in the present embodiment, the rear substrate 16 and the support plate 14 are inserted by inserting the base end portion of the wire 5 penetrating the back substrate 16 and protruding toward the support plate 14 into the escape hole 14a of the support plate 14. Therefore, the longitudinal dimension is shortened by an amount corresponding to the thickness of the support plate 14 as compared with the case where the clearance hole 14a is not provided. As a result, a compact optical pickup capable of promoting the overall miniaturization without particularly complicating the configuration is realized.

It is sectional drawing which follows the longitudinal direction of the optical pick-up which concerns on an Example. FIG. 3 is an exploded perspective view of the optical pickup. It is a top view of the optical pickup. It is a side view which shows one side part of this optical pick-up. It is a disassembled perspective view of the optical pick-up concerning a prior art example. It is a top view of the actuator with which this optical pick-up is equipped. It is sectional drawing of this actuator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Chassis 2 Actuator 3 Objective lens 4 Lens holder 5 Wire 6 Board | substrate support member 7 Magnet 8 Base member 10 Light emitting / receiving unit 11 Reflection mirror 13 Flexible wiring board 14 Support plate 14a Escape hole (escape part)
16 Back substrate (support substrate)
16a solder

Claims (3)

A lens holder to which an objective lens is attached, a support substrate that elastically supports the lens holder via a conductive wire, light emitting means for emitting a light beam to the disk via the objective lens, and A light emitting / receiving unit provided with a light receiving means for receiving a return light beam, a flexible wiring board having a wiring pattern to which the light receiving / emitting unit is connected, and an emission from the light emitting means arranged on the optical axis of the objective lens A reflection mirror that reflects the reflected light beam toward the objective lens and reflects a return light beam from the disk toward the light receiving means, and a chassis on which the support substrate, the light emitting and receiving unit, and the reflection mirror are mounted In an optical pickup with
The wire between the lens holder and the support substrate and the optical path of the light beam between the light emitting / receiving unit and the reflection mirror are separated in the optical axis direction of the objective lens and away from the center of the objective lens. and extend in the same direction as viewed,
A land portion to which the base end portion of the wire is soldered is provided on the surface of the support substrate on the side opposite to the lens holder, and the base end portion of the wire extends through the support substrate to the side opposite to the lens holder. And a support plate for attaching and supporting the flexible wiring board is disposed so as to face the surface of the support substrate on the side opposite to the lens holder, and a distal end of the wire is formed on the support plate. An optical pickup characterized by being inserted into the optical pickup.   2. The support substrate according to claim 1, wherein the support substrate is attached to the surface of the substrate support member on the side opposite to the lens holder and is mounted on the chassis via the substrate support member. The optical pickup, wherein the light emitting / receiving unit is attached to a side surface of the chassis so that an optical path of a light beam therebetween is formed between an inner bottom surface of the chassis and the substrate support member. 2. The optical pickup according to claim 1 , wherein the support plate is made of a metal material having good thermal conductivity.

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