JPH0132178Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial field of application> The invention is an optical disc player that reads and reproduces musical tone signals encoded and recorded on an optical disc, or an optical disc player that irradiates a laser beam onto an optical disc and encodes it. The present invention relates to an optical pickup device used in an optical recording and reproducing device for writing, reading, and reproducing information signals, and particularly relates to an optical pickup device that can be miniaturized.

<Background Art and its Problems> Conventionally, an optical pickup device used in an optical disk player includes a semiconductor laser that emits a laser beam, an optical system block that incorporates optical components that control the laser beam that is emitted from the semiconductor laser, and A holder with an objective lens mounted at a position apart from the axis is made rotatable about the axis and slidably displaced in the axial direction, and the objective lens is attached to the recording track of the optical disk. The objective lens driving device is configured to drive and displace the laser beam in two axes perpendicular to the tracking direction and the focus direction of the laser beam, and to control the laser beam focused by the objective lens to accurately track the recording track. .

The objective lens driving device of the optical pickup device configured as described above has a pair of fan-shaped first outer circumferential yokes and a pair of fan-shaped first outer circumferential yokes on a mounting substrate that serves as a mounting portion to the optical system block and constitutes a yoke of the magnetic circuit section. and the inner yokes of the magnets are arranged so as to face each other to form a magnetic gap, and a focusing magnet is arranged at the lower part of the outer yoke, and further positioned between the pair of outer yokes. It has a magnetic circuit section constructed by bonding and disposing tracking magnets on opposing surfaces of a pair of second outer circumferential yokes. At the center of this magnetic circuit section, a support shaft is installed on the mounting board, and the objective lens holder, which has the objective lens mounted at a position apart from the axis, can be rotated with respect to this support shaft. The support shaft is further slidably supported in the axial direction of the support shaft. The objective lens holder includes a focus drive coil that is inserted into the magnetic gap of the magnetic circuit section and slides the holder in the axial direction to drive the objective lens in the focus direction. A cylindrical body is integrally provided with a tracking drive coil disposed on the outer circumferential surface of the objective lens for rotating the objective lens in the tracking direction by rotationally displacing the objective lens in the direction around the axis. The objective lens drive device configured as described above detects the state of the beam spot of the laser beam reflected from the recording surface of the optical disk using a photodetector, and supplies a servo current to the focus drive coil and the detection output obtained by using the photodetector. The objective lens holder is driven and displaced in the axial direction and/or the direction around the axis so as to be supplied to a tracking driving coil, and the objective lens is driven and displaced in two axial directions, a focusing direction and a tracking direction. It acts to control the focus and tracking of the laser beam.

By the way, in the case of an objective lens drive device for a moving coil type optical pickup device in which a driving coil is attached to a cylindrical portion integrally provided to a holder that is movably supported with respect to a magnetic circuit portion as described above, A lead wire connected to the drive coil drawn out from the holder is swung as the holder moves, and is repeatedly bent and subjected to a load. In particular, the bending of the lead wires is significant in the vicinity of the connection portion to the relay board provided on the holder, easily bending and breaking the wires. Optical pickup devices for optical disk players that use semiconductor lasers have become more compact, and the holders to which the objective lenses are attached have also become lighter.
Along with this, the thrust force for driving the holder is also becoming smaller. Therefore, it is necessary to reduce the rigidity of the lead wire, and as a result, it is necessary to use a very thin lead wire with low rigidity and low mechanical strength. Under these circumstances, the risk of breakage of the lead wires that supply drive current to the drive coil attached to the holder is increasing.

Therefore, with the main purpose of preventing such breakage of the lead wires, the applicant of the present application has developed a method of elastically connecting the lead wires drawn out from the relay board provided on the holder with a support member provided near the relay board. We have previously proposed Utility Application No. 142130 (1983) to maintain this. By the way, the above proposal can sufficiently achieve the purpose of preventing breakage of the lead wire, but its specific structure is a relay formed of a flexible printed circuit board provided on the holder. The board is reinforced with a thin stainless steel plate, and a support member attachment part is formed at the tip of this thin stainless steel plate, and the support member is attached here to elastically hold the lead wire. The number of parts required to hold the wire increases, and an adhesive process is required to attach the thin stainless steel plate to the holder, making assembly difficult. Further, since two support members for holding the lead wires are provided symmetrically with respect to the neutral point of the holder, the number of parts is further increased. Furthermore, since the support member is provided so as to protrude outward from the holder, the rotation diameter of the holder is increased, which requires a larger rotation space for the holder, which makes the objective lens drive device more difficult to operate. This obstructs the purpose of downsizing the device.

<Purpose of the invention> Therefore, the present invention was proposed with the aim of solving the problems of the previous proposals as described above. The purpose of the present invention is to provide the supporting member without protruding, and to reduce the rotational diameter of the holder to further reduce the size of the objective lens driving device. The object of the present invention is to provide an optical pickup device that is easy to install and further reduces the number of parts.

<Summary of the invention> In order to achieve the above-mentioned purpose, the objective lens is attached and the driving coil is attached to the spindle, which is supported so as to be slidable in the axial direction and/or to be rotatable in the direction around the axis. A lead wire drawn out from the objective lens holder and supplying a drive current to the drive coil is fitted into an elastic holding member provided on the fixed part to hold the objective lens holder at a neutral point. The objective lens holder is supported by a support made of an elastic member supported by a support pin attached to the objective lens holder.

<Example> Hereinafter, specific examples of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the optical pickup device according to the present invention includes an optical system block 1 containing a semiconductor laser that emits a laser beam, and an objective lens 3 mounted at a position apart from the axis of an objective lens holder. and an objective lens drive device 2 which performs tracking and focus control by driving and displacing the optical disk in two mutually orthogonal axes, that is, the tracking direction and the focus direction.

The optical block 1 includes a collimation lens that controls the laser beam emitted from the semiconductor laser built in the housing 4 into parallel light, and a collimation lens that controls the laser beam emitted from the direction perpendicular to the optical axis of the objective lens. Reflection mirror 5 that reflects the laser beam to the objective lens, 1/ that rotates the polarization plane of the laser beam.
Optical components (not shown) such as a photodetector and a beam splitter for controlling the traveling direction of a laser beam reflected from a four-wavelength plate or a recording surface of an optical disk and detecting its output are built-in. Furthermore, the housing 4 of the optical system block 1 is provided with bearing holes 6 and 7 into which two rod-shaped feed guides of a pick-up feed mechanism provided in the player body (not shown) are inserted. This optical pick-up device is guided by a feed guide by the pick-up feed mechanism of the player body, and is operated to move around the inner and outer peripheries of the optical disk, so that a laser beam is tracked on the surface of the optical disk. Two rod-shaped feed guides and bearing holes 6, 7 through which these guides are inserted.
The configuration of the guide mechanism based on the combination of the above is configured such that the laser beam can be irradiated perpendicularly to the optical disk surface with high precision. Further, the housing 4 of the optical system block 1 is provided with a mounting section for the objective lens driving device 2, and a positioning recess 8 is formed in a portion of this mounting section that corresponds to the reflecting mirror 5. Then, the objective lens driving device 1 is placed on this mounting portion with the positioning member 10 attached to the lower surface of the mounting board 9 fitted into the positioning recess 8, and is fixed and assembled with screws 11. When the objective lens driving device 2 is assembled to the optical system block 1, the mounting position of the positioning member 10 is rotationally adjusted so that the optical axis of the objective lens 3 is aligned with the optical axis of the laser beam in the optical system block. can be installed by matching them precisely.

The objective lens driving device 2 assembled to the optical system block 1 as described above is constructed as shown in FIGS. 2 and 3, and serves as an attachment part to the optical system block 1 and a magnetic circuit part. On the mounting board 9 made of a magnetically permeable material such as soft iron, which constitutes the yoke, there are a pair of first outer circumferential yokes 12, 12 and a pair of inner circumferential yokes 13, 13 in a fan-shaped arc shape. are arranged at a predetermined interval so as to face each other to form a magnetic gap, and focus magnets 14, 14 are arranged below the outer circumferential yokes 12, 12, and the outer circumferential yokes A pair of second outer circumferential yokes 1 planted so as to be located between 12 and 12
A magnetic circuit section 17 is constructed in which tracking magnets 16, 16 are bonded to opposing surfaces of the magnets 5, 15.

As described above, the mounting board 9 on which the magnetic circuit section 17 is constructed has a fitting plate which is located in the center of the magnetic circuit section 17 and bulges toward the lower surface side, and is provided on the mounting section of the housing 4. A fitting portion 19 that fits into the hole 18 is provided, and a support shaft 20 located at the center of the magnetic circuit portion 17 is installed with its base end fitted and supported by the fitting portion 19. The objective lens 3 held by the lens rod 21 is attached to the support shaft 20 through a cylindrical boss portion 23 provided at the axis, and an objective lens holder 22 is mounted at a position spaced apart from the axis, that is, at an eccentric position. It is inserted and supported so that it can be rotated relative to the support shaft 20 and slidable in the axial direction of the support shaft 20. The objective lens holder 22 supported by the support shaft 20 is arranged so that the optical axis of the objective lens 3 and the optical axis of the optical system block 1 coincide with each other in the tracking direction at the neutral point, which is the non-operating state position. It is held by an elastic holding member 24 made of elastically displaceable rubber material or the like. This elastic holding member 24 is attached by bonding the base end portion 24a bent into an L-shape onto the mounting substrate 9 serving as a fixing portion. On the other hand, the objective lens holder 22 has a support pin 2 at a position symmetrical to the objective lens 3 about the support axis.
5 is vertically erected so that its upper end protrudes above the upper surface of the objective lens holder 22 and hangs down.
The objective lens holder 22 then attaches the lower end of the support pin 25 to the holding piece 2 of the elastic holding member 24.
By fitting and supporting the fitting hole 26 drilled in 4b, it is held at the neutral point as described above.

As described above, the elastic holding member 2 is supported by the support shaft 20.
The objective lens holder 22, which is held at the neutral point at 4 and attached to the magnetic circuit section 17, has openings corresponding to the pair of inner yokes 13, 13 provided on the mounting board 9, respectively. Part 27,
27 is formed, and when supported by the support shaft 20, the inner peripheral side yoke 1 is inserted into these openings 27, 27.
The upper ends of the lenses 3 and 13 are facing, and when configured as an objective lens driving device, the height thereof is as low as possible, that is, the device is designed to be thin. Further, a cylindrical body 28 that is inserted into the magnetic gap of the magnetic circuit section 17 is integrally provided on the objective lens holder 22 so as to hang down. A focus drive coil 29 slides and displaces the objective lens holder 22 in the axial direction to drive the objective lens 3 in the focus direction, and a focus drive coil 29 rotates and displaces the objective lens holder 22 in the axial direction to move the objective lens 3 in the tracking direction. A tracking drive coil 30 is provided for rotationally driving.
Note that the focus drive coil 29 is wound so as to generate a driving force that drives the objective lens holder 22 in the axial direction of the support shaft 20 in conjunction with the direction of the magnetic field of the focus magnets 14, 14. The driving coil 30 is wound so as to generate a driving force that drives the objective lens holder 22 in a direction around the axis of the support shaft 20 in conjunction with the direction of the magnetic field of the tracking magnets 16, 16.

The terminal lead wires of the focus drive coil 29 and the tracking drive coil 30 are arranged symmetrically with respect to the line connecting the support shaft 20 and the center of the objective lens 3, so that the lead wires are attached to the objective lens holder 22. It extends toward the upper surface side and is connected to a conductive pattern portion of a relay board 31 disposed on this objective lens holder 22 . This relay board 31 is formed of a flexible printed circuit board using a thin resin film as a base material, and is bonded to the support pin 25 side opposite to the objective lens 3 with the support shaft 20 at the center. Then, from the relay board 31, the support shaft 20
Connect multiple relay lead wires 3 symmetrically to both sides around the line connecting the center of the objective lens 3 and the center of the objective lens 3.
2 is drawn. In this way, the relay lead wire 3
By pulling out the objective lens holder 22, the weight balance of the objective lens holder 22 is maintained.

On the other hand, a focus drive coil 29 and a tracking drive coil 3 are disposed on the mounting board 9 so as to be located on the one second outer peripheral side yoke 15 side, that is, to face the relay board 31.
A flexible printed circuit board 33 that is connected to a power supply circuit that supplies a drive current to the 0 and serves as an external connection conductor is fixedly disposed. The flexible printed circuit board 33 is formed as a tape-like elongated body having a conductive pattern formed on a resin film base material.
Further, a pair of connection protrusions 34, 34 forming a connection pattern portion to which relay lead wires are connected are protruded in a U-shape on the sides of the end portion of the flexible printed circuit board 33. The flexible printed circuit board 33 is arranged on the mounting board 9 with the connecting protrusions 34 extending to both sides of the second outer peripheral side yoke 15, and is formed as shown in FIG. It is pressed and supported by a pressing member 39 and fixed to the mounting board 9 . A pressing member 39 that fixes this flexible printed circuit board 33
is formed by having a U-shaped pressing support part 35 in the center, and fixing parts 37, 37 having through holes 36, 36 formed on both sides of this pressing support part 35.
The pressing member 39 is a U-shaped pressing support portion 3.
5, a screw 38 is inserted through the through holes 36, 36 so as to press the connecting protrusions 34, 34;
38 is fixed onto the mounting board 9 to fix the flexible printed circuit board 33.

As described above, the connection pattern portions of the connection protrusions 34, 34 of the flexible printed circuit board 33 fixed to the mounting board 9 of the objective lens driving device 2 are provided with relay lead wires 32 drawn out symmetrically from the relay board 31. , 32 are connected to the drive circuit, the focus drive coil 29, and the tracking drive coil 30.
An electrical connection is made between the two.

By the way, in the present invention, it is positioned on the relay board 31 disposed on the upper surface of the objective lens holder 22, and elastically supports the vicinity of the connection part of the lead wire 32 drawn out from the relay board 31. A first support body 41 made of an elastic member such as silicone rubber is provided. This first support body 41 has a cylindrical portion 42 formed at its base end and an upper end portion of the support pin 25 that supports the elastic holding member 24 that holds the objective lens holder 22 at the neutral point. Annular groove part 4
3 and is supported by being inserted and fitted.

To further explain the first support body 41, as shown in FIG. 5, the first support body 41 has a lead wire support part 45, 45 is formed to expand in accordance with the direction in which the lead wire 32 is pulled out. The cylindrical portion 42 is formed by drilling an annular groove 46 around the through hole,
The support pin 25 is elastically displaced and press-fitted,
The elastic force of this cylindrical portion 42 alone acts to support the first support body 41 on the support pin 25. Therefore, the first support body 41 is fitted and supported by the support pin 25 without receiving any elastic displacement force.
This first support body 41 is formed to a size such that at least its tip does not protrude from the outer peripheral edge of the objective lens holder 22 when supported by the support pin 25 (see FIG. 3).

Further, the lead wire support parts 45, 45 are provided with recessed grooves 47, 47 for supporting lead wires in the longitudinal direction, and L-shaped leads are formed opposite to the front edge side opening ends of these recessed grooves 47, 47. Line locking portions 48, 48 are provided. Furthermore, these lead wire locking parts 4
Cut grooves 49, 49 are bored in the sides of the locking parts 8, 48 so as to obtain sufficient elastic displacement of the locking parts 48, 48.

The lead wires 32, 32 drawn out from the relay board 31 are connected to the concave groove 47 of the first support body 41,
47 respectively, and are further locked by the lead wire locking parts 48, 48 and extended to the external connection conductor 33, and the connecting protrusions 34,
They are respectively connected to 34 connection pattern sections.

Further, the vicinity of the connection portions of the lead wires 32, 32 to the respective connection ends 34, 34 of the external connection conductor 33 is also connected to a second support member 41 made of an elastic material such as silicone rubber, similar to the first support body 41. It is elastically supported by supports 51, 51. This second support body 51 consists of a lead wire support part 53 having a lead wire insertion hole 52 formed on the lower surface side and an L-shaped fitting part 54, and this fitting part 54 is connected to the pressing member 39. It is fitted onto the base end side of the fixing part 37 and mounted on the mounting board 9. In addition,
The second support body 51 is formed so that the lead wire support portion 53 comes into pressure contact with the surface of the external connection conductor 33 when the second support body 51 is fitted and disposed on the pressing member 39 . Each lead wire 32, 32 is connected to a lead wire support portion 53, 5.
The lead wires are inserted into the lead wire insertion grooves 52, 52 of No. 3 and connected to the respective connection ends 34, 34 of the external connection conductor 33, respectively. And each of the lead wires 32, 32
The vicinity of the connection to each connection end 34, 34 is the second
It is elastically supported by supports 51, 51.

Note that the side piece portion of the external connection conductor 33 that protrudes from the side of the mounting board 9 is bent along the folding groove 56 bored along the pressing member 39.
It is held on the soundproof cap 57, as shown in FIG. 1, by a holding piece 58 provided on the side of the soundproof cap 57 that covers the objective lens driving device 2.

In the optical pickup device configured as described above, when a drive current is supplied to the tracking drive coil 30 and/or the focus drive coil 29 of the objective lens drive device 2, the objective lens holder 20 is moved and displaced. Along with this, the relay lead wires 32, 32 begin to bend.
At this time, the lead wire 32 is connected to the first support 41
Since the lead wire 32 is elastically supported by the second support 51, concentration of stress due to bending motion can be prevented near the connection portions of the lead wire 32 to the relay board 31 and the external connection conductor 33 at both ends. That is, the first support body 41 supports the relay lead wire 3 while being elastically displaced.
2, 32, this lead wire 32, 3
The vibration caused by the bending motion of 2 is absorbed by the elastic displacement, and the stress caused by the bending motion is absorbed by the relay lead wire 3.
It is possible to prevent the concentration on 2 and 32. In particular, the lead wire locking portion 4 of the first support body 41
8 and 48 have cut grooves 49 and 49 formed on the sides to obtain a sufficient amount of elastic displacement, so that vibrations caused by the bending motion of the lead wires 32 and 32 are reliably absorbed, and Long concave groove 4
By supporting the lead wires 32, 32 by the leads 32, 47, the stress caused by the bending movement can be dispersed, and breakage of the wires can be prevented.

In the embodiment described above, an example was given in which the objective lens 3 is driven and displaced in two axial directions, the focus direction and the tracking direction, but the objective lens 3 may be driven only in one direction, either the focus direction or the tracking direction. Even when applied to a displacement optical pickup device, it is possible to prevent wire breakage due to bending movement of the relay lead wires 32, 32 as described above.

<Effects of the invention> As mentioned above, the present invention uses an elastic retainer provided on a fixed part such as a mounting board to hold the relay lead wire drawn out from the relay board at the neutral point of the objective lens holder. Since it is supported by a first support that is supported by a support pin attached to the objective lens holder that is fitted into the member,
The objective lens holder can be easily attached, and in particular, the weight of the objective lens holder can be reduced by using the support pins that also serve as support for the elastic holding member, providing an optical pickup device with good response characteristics to drive current. can.

Further, the first support for supporting the lead wire is supported by a support pin that is fitted into an elastic member that holds the objective lens holder at a neutral point, so that it is disposed on the objective lens holder. Since it can be set to a size that allows it to be placed within the upper surface of the objective lens holder, the outer circumferential diameter of the objective lens holder does not become large. Therefore, it is possible to contribute to miniaturization of the optical pickup device without increasing the rotation radius of the objective lens holder.

Furthermore, since the first support body is supported using support pins, it can be attached to the objective lens holder without using an adhesive, so that the workability of attachment can be significantly improved.

Furthermore, since the first support is supported by support pins protruding on the objective lens holder, it can be positioned on the inside of the upper surface of the objective lens holder as described above, so that it can be removed from the relay printed circuit board. The relay lead wire that spans the connecting conductor can be made long, and the influence of the rigidity of the lead wire on the driving force when driving the objective lens holder can be reduced, and the optical pickup device has good response characteristics. It becomes possible to provide.

[Brief explanation of the drawing]

FIG. 1 is an exploded perspective view showing an optical pickup device according to the present invention, FIG. 2 is a perspective view showing an objective lens driving device of the optical pickup device, FIG. 3 is a sectional view thereof, and FIG. This figure is a perspective view showing a pressing member attached to the objective lens driving device, and FIG. 5 is a perspective view similarly showing the first support body. 3... Objective lens, 20... Support shaft, 22... Objective lens holder, 24... Elastic holding member, 25...
...Support pin, 29...Focus drive coil, 30...Tracking drive coil, 32...
...Relay lead wire, 41...First support.

Claims (1)

[Scope of utility model registration request] The objective lens is attached and a drive coil is attached, and the objective lens holder is pulled out from the objective lens holder, which is supported so as to be slidable in the axial direction of the support shaft and/or rotatable in the direction around the axis, and supply a drive current to the drive coil. A lead wire is connected from an elastic member supported by a support pin attached to the objective lens holder, which is fitted into an elastic holding member provided on the fixed part to hold the objective lens holder at a neutral point. An optical pickup device supported on a support.