JP3606100B2 - Optical pickup - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical pickup for recording and reproducing by projecting a light spot on a disk.
[0002]
[Prior art]
A conventional optical pickup will be described below with reference to FIGS.
[0003]
FIG. 5 is an exploded perspective view showing a configuration of a conventional optical pickup, and FIG. 6 is a perspective view showing a configuration of the conventional optical pickup. 5 and 6, reference numeral 41 denotes an objective lens, and 42a denotes a lens holder for holding the objective lens 41. The lens holder 42a has a magnet 44a magnetized in the same direction as the tangential direction 43a with respect to the disk. 44b is fixed across the objective lens 41. The lens holder 42a is cantilevered by four wires 42c from the fixed frame 42b so as to be movable with respect to the disc in two axes, a vertical direction 43b and a radial direction 43c.
[0004]
Also, bobbin assemblies 45a and 45b are attached to the fixed frame 42b with the ACT substrate 49 interposed therebetween in close proximity to the magnets 44a and 44b. The bobbin assemblies 45a and 45b are directly wound with focus coils 46a and 46b on the axis 43b perpendicular to the disk and tracking coils 47a and 47b in the same direction with respect to the axis 43b perpendicular to the disk. . In addition, four pins 48 are formed by resin molding on the bobbin assemblies 45a and 45b, and the start ends and the end ends of the focus coils 46a and 46b and the tracking coils 47a and 47b are fixed by bending. The curled portion and the ACT substrate 49 are soldered, and the terminals of the ACT substrate 49 are electrically connected to the two coils.
[0005]
The fixed frame 42b configured in this way is fixed to the ACT base 50, and an actuator cover 68 is fixed to the fixed frame 42b substantially parallel to the disk to form an objective lens driving device 51. The objective lens driving device 51 is in contact with the spherical surface of the optical bench 52 and is slidable along the spherical surface at the same time pressed by two tilt screws 53 and an ACT pressing spring 54.
[0006]
Further, the DVDLD unit 56 is mounted on the flexible substrate unit 55 in the direction opposite to the laser emission direction, and the high frequency module substrate 57 is also mounted. The high-frequency module substrate 57 is folded on the back side of the DVDLD unit 56 and is laminated and fixed so as to cover the high-frequency module substrate 57 with a shield case 58. In addition, a CDLD unit 59, a connector 60, a chip volume 67, and an electronic component 61 are mounted on the flexible substrate unit 55, respectively.
[0007]
The DVDLD unit 56 is attached to the optical stage 52 so as to be rotatable with respect to the optical axis center in the laser emission direction, and the CDLD unit 59 is attached to the CDM attachment plate 62 screwed to the optical stage 52 in the laser emission direction. It is attached so as to be rotatable with respect to the optical axis center. The portion of the flexible board unit 55 where the connector 60 and the chip volume 67 are mounted is fixed to the side surface of the optical bench 52 in a direction 43b perpendicular to the disk. The DVDLD unit 56 and the CDLD unit 59 are unit pressing springs. 63 is pressed in the respective optical axis directions.
[0008]
Further, an optical component is attached to the optical bench 52 so that the light emitted from the DVDLD unit 56 passes through the wavelength prism 64, becomes parallel light by the collimating lens 65, and is reflected by the rising mirror 66 at 90 °. It has been. The reflected light is incident on the objective lens 41, reflected by the disk, and then returns on the same optical path. After the light emitted from the CDLD unit 59 is reflected by the wavelength prism 64, it follows the same optical path as the DVDLD unit 56 and returns to the CDLD unit 59.
[0009]
The optical pickup having the above-described configuration includes a unit pressing spring 63 in a direction 43b perpendicular to the disk, and presses the shield case 58 fixed to the back surface of the DVDLD unit 56 in the optical axis direction.
[0010]
In FIG. 6, 52 is an optical bench, 56 is a DVDLD unit mounted so as to be rotatable about the optical axis, and the flexible substrate unit 55 is folded at 180 ° on the back of the DVDLD unit 56. Further, on the back side, a high frequency module substrate 57 is mounted on the flexible substrate unit 55, and a series of components are fixed by a shield case 58 so as to cover the high frequency module substrate 57. The DVDLD unit 56 to the shield case 57 are fixed by the shield case 57. The optical stand 52 is pressed by the unit pressing spring 63 in the optical axis direction by a spring from the direction 43b perpendicular to the disk. .
[0011]
[Problems to be solved by the invention]
However, in the above-described conventional optical pickup, 56 is a DVDLD unit mounted so as to be rotatable about the optical axis, and the flexible substrate unit 55 is folded at 180 ° on the back of the DVDLD unit 56. Further, a high frequency module substrate 57 is mounted on the flexible substrate unit 55 and a series of components are fixed by a shield case 58 so as to cover the high frequency module substrate 57. The DVDLD unit 56 to the high frequency module substrate 57 are fixed by a shield case 58. The optical stand 52 is pressed by a unit pressing spring 63 in the optical axis direction by a spring from a direction 43b perpendicular to the disk. Therefore, the optical pickup cannot be thinned because of the configuration of the unit pressing spring 63. For this reason, an optical pickup for an ultra-thin drive is required.
[0012]
In view of the above-described conventional problems, the present invention is configured so that the unit pressing spring is pressed from a surface direction parallel to the disk, and is temporarily fixed to the optical bench by the spring force of the unit pressing spring itself, thereby assembling performance. An object of the present invention is to provide an ultra-thin optical pickup that is excellent in performance.
[0013]
[Means for Solving the Problems]
In order to solve this problem, an optical pickup according to the present invention includes an objective lens, an objective lens driving device capable of moving the objective lens in two directions, a vertical direction and a radial direction with respect to a disk, a DVD laser diode (hereinafter referred to as DVDLD). A unit, a flexible substrate on which the DVDLD unit can be mounted on the light emitting side in the back direction, a high-frequency module substrate mounted on the flexible substrate, and a shield case for shielding the high-frequency module substrate And a flexible substrate unit that is fixed by the shield case so as to cover the high-frequency module substrate by folding a flexible substrate portion on which the high-frequency module substrate is mounted in the back direction from the light emitting side of the DVDLD unit, and the DVDLD unit Is centered on the optical axis in the light exit direction And optical bench mounted so as to be rotated to fix the shield case so that the DVDLD unit does not fall off and the pressing part for pressing the end portion in the optical axis direction, to the optical bench in a substantially other end fixed as It has a substantially arcuate units presser spring, and an optical system for the light emitted from the DVDLD unit to the optical bench configured incident on the objective lens and a end portion, the front Stories solid Teitan unit the L-shaped projection for holding Kakaekomi the intermediate portion between the pressing portion is obtained by constituting the optical bench.
[0014]
As a result, it is possible to provide an ultra-thin optical pickup that is temporarily fixed to the optical bench by the spring force of the unit pressing spring itself and has excellent assemblability.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
According to the first aspect of the present invention, there is provided an objective lens, an objective lens driving device capable of moving the objective lens in two directions of a perpendicular direction and a radial direction with respect to a disk, and a DVD laser diode (hereinafter abbreviated as DVDLD). ) Unit, a flexible substrate on which the DVDLD unit can be mounted in the back direction from the light emitting side, a high-frequency module substrate mounted on the flexible substrate, a shield case for shielding the high-frequency module substrate, A flexible substrate unit in which the high-frequency module substrate is mounted is folded in the back direction from the light emitting side of the DVDLD unit, and the flexible substrate unit is fixed by the shield case so as to cover the high-frequency module substrate. Can be rotated around the optical axis in the direction of the emission side Comprises an optical base that is attached to cormorants, a pressing portion which the DVDLD unit presses the end portion of the shield case so as not to fall off in the direction of the optical axis, and a fixed end fixed to the optical base at substantially the other end substantially arcuate units holding spring, the and an optical system configured to light emitted in the optical bench from the DVDLD unit enters the objective lens, the front Stories solid Teitan portion between the pressing portion The L-shaped projection that holds and holds the middle part is configured on the optical bench, and the unit pressing spring is held at the center against the spring force. By being temporarily fixed to the optical bench by the spring force of the spring itself, it is possible to provide an ultra-thin optical pickup excellent in assemblability.
[0016]
Hereinafter, embodiments of the present invention will be described with reference to FIGS.
[0017]
(Embodiment 1)
1 and 2 are exploded perspective views showing the optical pickup according to the first embodiment of the present invention, and FIGS. 3 and 4 are perspective views showing the optical pickup according to the first embodiment of the present invention. Reference numeral 1 denotes an objective lens. Reference numeral 2 denotes a lens holder for holding the objective lens 1. Magnets 3 a and 3 b magnetized in the same direction as the tangential direction 14 with respect to the disk are attached to the lens holder 2. Is fixed at a position offset in the opposite direction. A spring substrate 4 is fixed to the lens holder 2, and four metal wire springs 5a to 5d for cantilevering the lens holder 2 are fixed to the spring substrates 4a and 4b by solder. The metal wire springs 5a to 5d pass through the suspension holder 6 and are fixed by soldering to a damping support plate 7 formed integrally with the suspension holder 6 to form a fixed end. The lens holder 2 is movable in two axial directions, a vertical direction 16 and a radial direction 17 with respect to the disk.
[0018]
A bobbin 8 is attached to the actuator base 9 in close proximity to the magnets 3a and 3b. The bobbin 8 is directly wound with a focus coil 10 on an axis 16 perpendicular to the disk and a tracking coil 11 on the disk in the same direction with respect to an axis 17 in the radial direction. When current flows through each of the focus coil 10 and the tracking coil 11, the lens holder 2 moves in the vertical direction 16 and the radial direction 17 with respect to the disk. Further, the start and end of the focus coil 10 and the tracking coil 11 are soldered to the ACT-FPC 12, and the terminals of the ACT-FPC 12 are electrically connected to the two coils. A lens protector 14 is attached to the lens holder 2 to protect the objective lens 1 and the disc when the counterweight 13 and the objective lens 1 collide with the disc.
[0019]
The suspension holder 6 is fixed to an actuator base 9, and the actuator base 9 is configured to be substantially parallel to the disk and forms an objective lens driving device 18. The objective lens driving device 18 is adjusted and fixed at the best position with respect to the optical bench 19. Further, after adjusting and fixing the objective lens driving device 18, the leg 8 a opposite to the actuator base 9 of the bobbin 8 which is a part of the objective lens driving device 18 is fixed to the optical bench 18. A prism 20, a collimator lens 21, a holo unit 22, and a rising mirror 23 are disposed on the optical bench 19 in a tangential direction 15 with respect to the disk, and the collimator lens 21 is attached so as to be movable and adjustable in the tangential direction 15. Yes.
[0020]
Further, the DVDLD unit 25 is mounted on the flexible substrate unit 24 in the direction opposite to the laser emission direction, and the high-frequency module substrate 26 is also mounted. The high-frequency module substrate 26 is folded on the back side of the DVDLD unit 25, and is laminated and fixed so as to cover the high-frequency module substrate 26 with a shield case 27. In addition, a CDLD unit 28 is mounted on the flexible substrate unit 24 in the laser emission direction. A CDM adjusting plate 29 is provided on the back surface opposite to the laser emission direction, and a CDM is provided on the laser emission side. The holder 30 is fixed.
[0021]
The flexible substrate unit 24 is mounted on the optical bench 19 so that the DVDLD unit 25 is tilted from a tangential direction 15 of the disk in a plane parallel to the disk so that the DVDLD unit 25 can rotate around the optical axis. It is attached in the tangential direction 15 and can be moved and adjusted in a plane perpendicular to the tangential direction 15. The DVDLD unit 25 and the CDLD unit 28 are fixed to the side surface of the optical bench 19, and are pressed and held in the laser emission direction by the long unit holding spring A31 and the unit holding spring B32 configured within the thickness range of the optical bench 19, respectively. ing. The unit pressing spring A31 is cantilevered to the optical bench 19, and the tip is a convex portion so that the position variation in the vertical direction 16 with respect to the disk can be eliminated and the stable pressing position and the displacement of the unit pressing spring A31 can be regulated. The protrusion 31a is in contact with and pressed against a concave groove 27a provided in the shield case 27. Further, in order to prevent the flexible substrate unit 23 from floating, two pressing springs A33 and pressing springs B34 are attached to the optical bench 19 at the mounting portions 33a and 34a so as to sandwich the optical bench 19 from a plane direction parallel to the disk. Screws (not shown) are fixed and attached. A part of the pressing spring B34 is engaged and fixed to the unit pressing spring A31.
[0022]
Further, the light emitted from the DVDLD unit 25 and the CDLD unit 28 is reflected and transmitted through the prism 20 to become parallel light at the collimator lens 21, and after passing through the holo unit 22, it is perpendicular to the disk by the rising mirror 23. 16 and is incident on the objective lens 1.
[0023]
In the configuration as described above, the unit pressing spring A31 is cantilevered and fixed to the optical bench 19, but is pressed against the fixed end 31b of the unit pressing spring A30 by an L-shaped protrusion 19a provided on the optical bench 19. Since it is held so as to hold an intermediate part with the part (projection part 31a) , it is temporarily fixed and self-held by the spring pressure of the unit pressing spring A31 itself, and the workability when fixing to the optical bench 19 with a screw or the like is greatly improved. In addition, since the fixing force can be halved, it is particularly effective when the optical bench 19 is made of zinc or the like having creep characteristics.
[0024]
Further, the holding spring A33 is screwed to the optical bench 19 by the mounting portion 33a, and at the same time, a part 33b on the substantially opposite side is held between the projection 19b and the substantially flat portion 19c of the optical bench 19. For this reason, it is possible to realize a thin optical pick without being fixed to the optical bench 18 together with the flexible substrate 24 and the holding spring A33 being lifted by the reaction force of the flexible substrate 24.
[0025]
The objective lens driving device 18 is adjusted and fixed to the optical bench 19, and the leg 8a opposite to the portion fixed to the actuator base 9 of the bobbin 8 which is a part of the objective lens driving device 18 is fixed to the optical bench 19. Therefore, the bobbin 8 is like a column connecting the actuator base 9 located on the upper surface of the optical pick and the optical bench 19 located on the lower surface, and the actuator base 9 and the optical bench 19 may be directly fixed. And realizes a solid three-dimensional structure. Also, since the bobbin 8 itself is firmly fixed at the top and bottom, an optical pick that does not cause harmful vibration or displacement due to the reaction force received from the magnets 3a and 3b when the objective lens is driven and does not impair the original characteristics. It can be realized.
[0026]
FIG. 4 is a partial perspective view of the actuator base 9 as viewed from the arrow A with a bent portion 9b having substantially the same shape as the bent portion 9a positioned on the opposite side of the bent portion 9a and a part 19d of the optical bench 19. However, when the objective lens driving device 18 is adjusted to the best position with respect to the optical bench 19 and fixed, the bending leg 9b of the actuator base 9 which is a part of the objective lens driving device 18 is attached to the optical bench 19 with an adhesive. As shown in FIG. 4, the outer wall portion 19d of the optical bench 19 is provided with a structure in which the adhesive tends to accumulate, so that sufficient adhesive is used to wrap the bending leg portion 9b of the actuator base 9. In addition, it is possible to realize a highly reliable optical pick in which the adhesive does not flow into the optical bench 19.
[0027]
【The invention's effect】
As described above, according to the present invention, the objective lens, the objective lens driving device capable of moving the objective lens in two directions, the vertical direction and the radial direction, with respect to the disk, the DVD laser diode (hereinafter abbreviated as DVDLD) unit, A flexible substrate on which the DVDLD unit can be mounted in the rear direction from the light emitting side, a high-frequency module substrate mounted on the flexible substrate, a shield case for shielding the high-frequency module substrate, and the DVDLD unit The light emission side is a flexible substrate unit in which the high-frequency module substrate is mounted in the back direction and the flexible substrate unit is fixed by the shield case so as to cover the high-frequency module substrate, and the DVDLD unit is in the light emission direction. So that it can rotate around the optical axis It comprises an optical base that is Attach, and the pressing part for pressing an end portion of the shield case to the DVDLD unit does not fall off in the direction of the optical axis, and a fixed end fixed to the optical base at substantially the other end substantially arcuate units holding spring, the and an optical system configured to light emitted in the optical bench from the DVDLD unit enters the objective lens, the front Stories solid Teitan portion between the pressing portion By constructing the L-shaped projection holding and holding the intermediate portion in the optical bench, the intermediate portion between the fixed end portion of the unit pressing spring A and the pressing portion is formed by the L-shaped projection provided on the optical bench. Since it is held by the L-shaped projection so as to be held, it is temporarily fixed and self-held by the spring pressure of the unit pressing spring A itself, and the workability when fixing to the optical bench with a screw or the like is greatly improved and fixed. The power to do Since it reduced, etc. can be set low tightening torque of the screws, the optical bench is particularly effective when such as zinc having a creep properties.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view showing an optical pickup according to Embodiment 1 of the present invention. FIG. 2 is a perspective view showing an optical pickup according to Embodiment 1 of the present invention. FIG. 4 is a partially exploded perspective view showing an optical pickup according to Embodiment 1 of the present invention. FIG. 5 is an exploded perspective view showing a conventional optical pickup. FIG. 6 is a perspective view showing a conventional optical pickup. [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Objective lens 2 Lens holder 3 Magnet 6 Suspension holder 8 Bobbin 9 Actuator base 15 Tangent direction 16 Vertical direction 17 Radial direction 18 Objective lens drive device 19 Optical stand 24 Flexible board unit 25 DVDLD unit 26 High frequency module board 27 Shield case 31 Unit holding Spring A
32 Unit holding spring B
33 Presser spring A
34 Presser spring B

Claims (1)

An objective lens;
An objective lens driving device capable of moving the objective lens in two directions of a perpendicular direction and a radial direction with respect to the disk;
A DVD laser diode (hereinafter abbreviated as DVDLD) unit;
A flexible substrate on which the DVDLD unit can be mounted in the back direction from the light emitting side;
A high-frequency module substrate mounted on the flexible substrate;
A shield case for shielding the high-frequency module substrate;
A flexible substrate unit fixed by the shield case so as to cover the high-frequency module substrate by folding a flexible substrate portion on which the high-frequency module substrate is mounted in the back direction with respect to the light emitting side of the DVDLD unit;
An optical bench mounted so that the DVDLD unit can be rotated around the optical axis in the light emitting side direction;
A substantially bow-shaped unit pressing spring comprising a pressing portion that presses the shield case at the end in the optical axis direction so that the DVDLD unit does not fall off, and a fixed end that is fixed to the optical bench at a substantially other end;
And an optical system configured to incident light emitted from the DVDLD unit to the optical bench to the objective lens,
Before SL Solid Teitan unit and the optical pickup of the L-shaped projection for holding Kakaekomi intermediate portion is characterized by being configured to the optical bench of the pressing portion.

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