JP3695533B2 - Optical pickup device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical pickup device that records and reproduces various kinds of information on an information recording medium such as a CD or a DVD (hereinafter sometimes referred to as “optical disk”), and in particular, a focus error signal and a tracking error signal. The present invention relates to an optical pickup device having an improved mechanism for assembling a grating that is incorporated in order to generate a light source.
[0002]
[Prior art]
In general, an optical system of an optical pickup device generally includes a cylindrical LD (laser diode) that emits laser light, a resin-made cylindrical grating that diffracts laser light from the LD , and diffracted light from the grating. An objective lens that focuses the light on the optical disk and a photodetector that receives the return light from the optical disk through the objective lens. Of these, the LD and the grating mainly emit the laser light (diffracted light) in the emission direction. From the standpoint of stabilization, an integrated light source unit is formed by assembling to a base portion constituting a part of the optical pickup apparatus main body.
[0003]
A conventional example of this light source unit will be described with reference to FIG. The base portion 11 has a cylindrical shape, and along its axial center, an accommodation recess 11a is formed whose opening side is slightly smaller than the diameter of the LD 2 and whose bottom side is substantially the same diameter as the grating 3, and on the bottom surface of this accommodation recess 11a A through hole 11b that is smaller than the diameter of the grating 3 and allows diffracted light to pass therethrough is formed coaxially.
Its housing recess 11a, the grating 3, paten ring 101 such as a flat washer, and the compression coil spring 102 is inserted in this order coaxially, are further LD 2 is lightly press-fitted, the LD 2 is An end (not shown) is fixed by a plate 13 bolted to the optical pickup apparatus main body while penetrating the pair of LD terminals 2a.
[0004]
In this state, the elastic force of the compression coil spring 102 is applied to the grating 3 via the disc ring 101 in the axial direction, so that the grating 3 is pressed against the bottom surface of the housing recess 11a and the axial movement is restricted. At the same time, rotation around the axis is held possible.
The reason for holding the grating 3 so as to be rotatable in this way is to adjust the phase of the grating 3 in the holding state, and the phase adjustment is performed by forming a rod-shaped adjusting jig in the base portion 11 in the circumferential direction. This is done by inserting through the notch (not shown) into a groove (not shown) formed in the axial direction on the outer peripheral surface of the grating 3 and forcibly moving it along the notch.
[0005]
Here, the grating 3 and the compression coil spring 102 are not in direct contact with each other but indirectly in contact with each other via the disc ring 101. As disclosed in Japanese Patent Application Laid-Open No. 2000-285494, This is to prevent the torsional repulsion force of the compression coil spring 102 from being generated when the phase of the grating 3 is adjusted. That is, as the grating 3 rotates, the rear surface of the grating 3 that contacts each other and the front surface of the disk ring 101 slide, whereby the torsional repulsion force in the compression coil spring 102 that contacts the rear surface of the disk ring 101 is smooth. Will be released. Accordingly, the shaft does not rotate while the grating 3 is caught, nor does the grating 3 cause an unplanned axial rotation shift due to the action of the repulsive force remaining after the phase adjustment.
[0006]
[Problems to be solved by the invention]
However, in order to be able to perform such phase adjustment, at least separate parts such as the disc ring 101 and the compression coil spring 102 are required, so that complicated parts management and assembly work are forced, and a cost reduction request is required. There is also a problem that it is not able to respond sufficiently.
[0007]
Therefore, the present invention has been made in view of the above-described problems, and suppresses complicated parts management and assembly work and reduces the number of parts in order to respond to a request for cost reduction. An object of the present invention is to provide an optical pickup device that can be adjusted sufficiently.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, an optical pickup device according to the present invention includes a cylindrical grating that diffracts laser light, a disk ring having substantially the same diameter as the grating, and a compression coil spring that presses the grating in the axial direction together with the disk ring. In addition, in the optical pickup device having the receiving concave portion in which the LD that supports the compression coil spring and emits the laser light is inserted in this order, the diameter of the grating is substantially the same as the disk ring and the compression coil spring. A disc-ring shaped plate-like portion having the same diameter and in contact with the rear surface of the grating, and a tip portion bent at an acute angle while protruding from the edge of the plate-like portion at an obtuse angle, elastically deformed, and the LD It said projecting pieces and a pair of projecting pieces in contact with the front surface, but includes an elastic body formed by integrally molded on the inner peripheral surface of the concave of It is formed along the axial direction receiving groove for receiving the. Therefore, the phase adjustment mechanism by rotating the grating shaft conventionally requires at least two parts, a disc ring and a compression coil spring, but instead of this, it can be covered by a single part called an elastic body.
[0009]
In the optical pickup device according to the present invention, a cylindrical grating that diffracts laser light, an elastic body that presses the grating in the axial direction, and an LD that supports the elastic body and emits the laser light are inserted in this order. in the optical pickup apparatus having a housing recess that, the elastic body includes a plate portion having a through hole for passing the laser light is formed in contact with the rear surface of the grating, out edge or et collision of the plate-like portion a plurality of projecting pieces in contact with the front surface of the LD is elastically deformed, but which Tsu Na are integrally molded, the inner peripheral surface of the accommodating recess receiving grooves axially for receiving the protruding pieces Are formed along . Therefore, the phase adjustment mechanism based on the rotation of the grating shaft can be covered by an integral part called an elastic body.
[0010]
Here, when adjusting the phase of the grating, the plate-like portion has a disk ring shape having the same diameter as that of the grating so that the grating and the plate-like portion of the elastic body stably come into contact with each other and slide. It is preferable that
[0011]
Further, it is preferable that each projecting piece is bent at an obtuse angle at the edge of the plate-like portion in consideration of the ease of manufacturing the elastic body.
[0012]
Furthermore, it is preferable that the tip of each protruding piece is bent at an acute angle so that the front surface of the LD is not inadvertently damaged by elastic contact with each protruding piece.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an optical system of an optical pickup device of the present invention, FIG. 2 is a longitudinal sectional view of a light source unit in the optical pickup device, FIG. 3 is a sectional view taken on line AA in FIG. FIG. 5 is an external view of a grating in the optical pickup device, and FIG. 6 is an external view of an elastic body in the optical pickup device. In addition, the same code | symbol is attached | subjected to the part of the same name in a figure.
[0014]
As shown in FIG. 1, the optical system of the optical pickup device 1 includes a light source unit 4 integrally provided with an LD 2 and a grating 3, and laser light (diffracted light) emitted from the light source unit 4 on an optical disk 10. A beam splitter 5 such as a half mirror or a prism that reflects the reflected light from the optical disk 10, a collimator lens 6 that converts the reflected light from the beam splitter 5 into parallel light, and a beam from the collimator lens 6. The objective lens 7 focuses the parallel light on the recording surface of the optical disk 10, and the photodetector 9 receives the return light from the optical disk 10 that has passed through the beam splitter 5 via the sensor lens 8.
[0015]
The light source unit 4, the accommodating recess 11a formed in the base portion 11 that constitutes a part of the optical pickup apparatus 1 main body, the grating 3, the elastic body 12 and the LD 2 is incorporated in this order coaxially, its LD 2 It is fixed by a plate 13 (see FIG. 2).
[0016]
In describing the configuration of the light source unit 4 more specifically, first, details of the LD 2, the grating 3, and the elastic body 12 will be described in order. The LD 2 has a cylindrical shape, and a pair of LD terminals 2a are provided on the rear end surface.
[0017]
The grating 3 has a cylindrical shape that is slightly smaller than the diameter of the LD 2 and, as shown in FIG. 5, performs a diffraction action on the laser light that passes through the axial vicinity 3a. Further, a groove 3b into which an adjustment jig is inserted for phase adjustment is formed on the outer peripheral surface of the grating 3 in the axial direction (see FIG. 3). On the rear surface of the grating 3, four protrusions 3c are formed at equal angular intervals on the outer side of the axial vicinity portion 3a for adjusting the correction with respect to the straightness of the axis.
[0018]
The elastic body 12 is manufactured from a metal plate such as spring steel, such as SUS, and as shown in FIG. 6, a laser beam passing through hole 12c is formed in the axial center with substantially the same diameter as the grating 3. The formed disc ring-shaped plate-like portion 12a and a pair of projecting piece portions 12b that are bent at an obtuse angle from the edge of the plate-like portion 12a are integrally formed. Therefore, each protrusion 12b is
The plate-like portion 12a is elastically deformed by an axial load, and serves as a so-called leaf spring. The tip portion of each protruding piece 12b is rounded without rose corner bent at an acute angle, which is the elastic contact of the front surface of the LD 2, inadvertent the LD 2 This is to prevent damage. Such an elastic body 12 is easily manufactured, for example, by cutting and punching the integrated contour shape of the plate-like portion 12a and the protruding piece portion 12b from a metal plate, and then bending.
[0019]
Next, the base portion 11 is manufactured from a resin such as a cylindrical plastic,
An accommodation recess 11a having an opening side slightly smaller than the diameter of the LD 2 along its axis and a bottom side substantially the same diameter as the grating 3 is formed, and diffracted light smaller than the diameter of the grating 3 is formed on the bottom surface of the accommodation recess 11a. A common through hole 11b is formed coaxially. In addition, a pair of receiving grooves 11c for receiving the protruding pieces 12b of the elastic body 12 are formed in the inner peripheral surface of the housing recess 11a in the axial direction from the opening side to the middle stage (see FIG. 4). Further, the base portion 11 is formed with a through cut 11d that penetrates the housing recess 11a in the circumferential direction and into which an adjustment jig is inserted for phase adjustment (see FIG. 3).
[0020]
The grating 3 and the elastic body 12 are coaxially inserted in this order into the accommodating recess 11a, and the LD 2 is lightly press-fitted. The LD 2 penetrates the pair of LD terminals 2a, and ends ( (Not shown) is fixed to the optical pickup device 1 main body by a plate 13 which is bolted.
[0021]
In this state, the elastic body 12 is such that each projecting piece 12b is elastically deformed and each tip thereof contacts the front surface of the LD 2, and the front surface of the plate-like portion 12a is the rear surface of the grating 3 (in this embodiment). The projection 3c) is in contact with the projections 3c, and the elastic force of the projections 12b is applied to the grating 3 in the axial direction. Therefore, the grating 3 is pressed against the bottom surface of the housing recess 11a to restrict movement in the axial direction, and is held so as to be able to rotate around the axis, thereby enabling phase adjustment.
[0022]
The phase adjustment is performed by inserting a rod-shaped adjustment jig from the through-cut 11d of the base portion 11 into the groove 3b of the grating 3, and forcibly moving the grating 3 along the through-cut 11d as it is to rotate the axis of the grating 3. It is done. At that time, the rear surface of the grating 3 (each projection 3c) and the front surface of the plate-like portion 12a are in contact with each other and slide smoothly.
Since the plate-like portion 12a and the grating 3 have substantially the same diameter, a uniform contact state can be maintained and mutual sliding can be stabilized.
[0023]
As described above, in the optical pickup device 1 according to the present embodiment, instead of the two parts, the disk ring 101 and the compression coil spring 102, which have been conventionally required, one part, the elastic body 12, can be used. In comparison, the number of parts can be reduced. Therefore, it is possible to suppress complicated parts management and assembling work as compared with the prior art, and to respond to a cost reduction request.
[0024]
In addition, this invention is not limited to said embodiment, A various change is possible in the range which does not deviate from the meaning of this invention. For example, each protruding piece 12b of the elastic body 12 may be bent after protruding from the plate-like portion 12a as long as it functions as a leaf spring by elastic deformation, and the number thereof is three or more. There may be.
[0025]
【The invention's effect】
As described above, according to the present invention, a cylindrical grating that diffracts laser light,
A disk ring having substantially the same diameter as this grating, a compression coil spring that presses the grating in the axial direction together with this disk ring, and an LD that supports the compression coil spring and emits the laser light are inserted in this order. In this optical pickup device, in place of the disk ring and the compression coil spring, a disk ring-shaped plate-shaped portion that is substantially the same diameter as the grating and contacts the rear surface of the grating, and an edge of the plate-shaped portion A pair of projecting pieces that are bent at an obtuse angle and projecting at an obtuse angle while the tip is bent at an acute angle and elastically deformed to come into contact with the front surface of the LD . since the inner circumferential surface of the housing recess receiving groove for receiving the protruding pieces are formed along the axial direction, the phase control mechanism by axial rotation of the grating Nitsu Te In the past, were required two components of at least a disk ring and the compression coil spring, so that can cover one part of the elastic body in place of this. Therefore, since the number of parts is reduced as compared with the prior art, it is possible to suppress complicated parts management and assembly work and to meet a cost reduction request.
[0026]
According to the present invention, the cylindrical grating that diffracts the laser light, the elastic body that presses the grating in the axial direction, and the LD that supports the elastic body and emits the laser light are inserted in this order. In the optical pickup device having a recess, the elastic body is:
Abutting plate portion on the rear surface of the through hole for passing the laser beam is formed the grating, the plurality of protruding portions in contact with the front surface of the plate-like portion of the edge or et butt out elastically deformed by the LD When, but has Tsu Na are integrally formed, since the inner peripheral surface of the housing recess receiving groove for receiving the protruding pieces are formed along the axial direction, the phase control mechanism by axial rotation of the grating Can be covered by an integral part called an elastic body. Therefore, similarly to the above-described effect, the number of parts is reduced as compared with the conventional one, so that complicated parts management and assembly work can be suppressed and a cost reduction request can be met.
[0027]
Here, if the plate-like portion is a disc ring shape having a diameter substantially the same as the diameter of the grating, the grating and the plate-like portion of the elastic body abut on each other when adjusting the phase of the grating. The movement becomes stable.
[0028]
Further, when each protruding piece is bent at an obtuse angle at the edge of the plate-like portion, for example, the integrated contour shape of the plate-like portion and the protruding piece portion is cut or punched from a metal plate. After that, the elastic body can be easily manufactured simply by bending.
[0029]
Further, if the tip of each protruding piece is bent at an acute angle, the tip does not become square, so even if it elastically contacts the front surface of the LD , it will not cause inadvertent damage.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an optical system of an optical pickup device of the present invention.
FIG. 2 is a longitudinal sectional view of a light source unit in the optical pickup device of the present invention.
3 is a cross-sectional view taken along a line AA in FIG.
4 is a cross-sectional view taken along the line BB in FIG.
FIG. 5 is an external view of a grating in the optical pickup device of the present invention,
(A) is a rear view, (b) is a side view.
6A and 6B are external views of an elastic body in the optical pickup device of the present invention, where FIG. 6A is a rear view, and FIG. 6B is a side view.
FIG. 7 is a longitudinal sectional view of a light source unit in a conventional optical pickup device.
[Explanation of symbols]
1 Optical pickup device 2 LD
2a LD terminal 3 grating 3a axial vicinity 3b groove 3c protrusion 4 light source unit 11 base 11a receiving recess 11b through hole 11c receiving groove 11d through cut 12 elastic body 12a plate-like part 12b protruding piece 12c through hole 13 plate

Claims (5)

A cylindrical grating that diffracts laser light, a disk ring having substantially the same diameter as the grating, a compression coil spring that presses the grating in the axial direction together with the disk ring, and an LD that supports the compression coil spring and emits the laser light However, in the optical pickup device having an accommodation recess inserted in this order,
Instead of the disk ring and the compression coil spring, a disk ring-shaped plate portion that is substantially the same as the diameter of the grating and abuts against the rear surface of the grating, and the edge of the plate portion is bent at an obtuse angle. And a pair of projecting pieces that are elastically deformed and come into contact with the front surface of the LD , and an inner peripheral surface of the housing recess. The optical pickup device is characterized in that a receiving groove for receiving each protruding piece is formed along the axial direction . In an optical pickup device having a cylindrical grating that diffracts laser light, an elastic body that axially presses the grating, and an LD that supports the elastic body and emits the laser light is inserted in this order. ,
Said elastic body includes a contacting plate portion on the rear surface of the through hole for passing the laser beam is formed the grating, it comes into contact with the front surface of the plate-like portion of the edge or et butt out elastically deformed by the LD a plurality of projected pieces, but has Tsu Na are integrally formed, the inner circumferential surface of the accommodation recess, characterized in that the receiving groove for receiving the protruding pieces are formed along the axial direction Optical pickup device.   3. The optical pickup device according to claim 2, wherein the plate-like portion has a disk ring shape having substantially the same diameter as that of the grating.   4. The optical pickup device according to claim 2, wherein each of the projecting pieces is bent at an obtuse angle at an edge of the plate-like portion.   5. The optical pickup device according to claim 2, wherein a tip end portion of each protruding piece is bent at an acute angle.

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