JP2004241117A - Optical pickup - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make an optical pickup extremely thin to improve portability in the optical pickup used for an optical disk playback device. <P>SOLUTION: In an optical pickup constituted of a flexible substrate unit 24, an optical mount 19 and a pressure spring A33, the pressure spring A33 is screwed to the optical mount 19 at an attaching part 33a, and simultaneously, one part 33b of its opposite side is interposed between a projection part 19b of the optical mount 19 and almost a flat part 19c and closely fixed to the optical mount 19 along with the flexible substrate 24, so that a thin optical pickup is realized. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an optical pickup that performs recording and reproduction by projecting a light spot on a disk.

  2. Description of the Related Art As a conventional optical pickup, for example, Patent Document 1 is known. The contents described in Patent Document 1 will be described with reference to FIGS.

  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 a conventional optical pickup. 5 and 6, reference numeral 41 denotes an objective lens, 42a denotes a lens holder for holding the objective lens 41, and a magnet 44a magnetized in the same direction as the tangential direction 43a with respect to the disk, Reference numeral 44b is fixed across the objective lens 41. The lens holder 42a is cantilevered by four wires 42c from a 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.

  Further, bobbin assemblies 45a and 45b are attached to the fixed frame 42b very close to the magnets 44a and 44b with the ACT board 49 interposed therebetween. On the bobbin assemblies 45a and 45b, focus coils 46a and 46b are wound directly on an axis in a direction 43b perpendicular to the disk, and tracking coils 47a and 47b are wound directly on the axis in a direction 43b perpendicular to the disk. . Further, four pins 48 are formed on the bobbin assemblies 45a and 45b by resin molding, and start and end ends of the focus coils 46a and 46b and the tracking coils 47a and 47b are fixed. The horn portion and the ACT board 49 are soldered, and the terminals of the ACT board 49 are electrically connected to the two coils.

  The fixed frame 42b thus configured is fixed to the ACT base 50, and the actuator cover 68 is fixed to the fixed frame 42b substantially in parallel with the disk to form the 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 pressed by two tilt screws 53 and an ACT pressing spring 54, and is slidable along the spherical surface.

  A DVDLD unit 56 is mounted on the flexible substrate unit 55 in the direction opposite to the laser emission direction, and a high-frequency module substrate 57 is also mounted. The high-frequency module substrate 57 is foldable on the rear side of the DVDLD unit 56, and is covered and fixed by a shield case 58 so as to cover the high-frequency module substrate 57. In addition, in addition to the flexible board unit 55, a CDLD unit 59, a connector 60, a chip volume 67, and an electronic component 61 are mounted.

  The DVDLD unit 56 is mounted on the optical bench 52 so as to be rotatable about the optical axis in the laser emission direction. The CDLD unit 59 is mounted on a CDM mounting plate 62 screwed to the optical bench 52 in the laser emission direction. It is mounted so as to be rotatable about the optical axis center. The portion of the flexible board unit 55 on which the connector 60 and the chip volume 67 are mounted is fixed to the side surface of the optical table 52 in a direction 43b perpendicular to the disc, and the DVDLD unit 56 and the CDLD unit 59 are unit presser springs. At 63, it is held down in each optical axis direction.

  The optical table 52 is provided with an optical component such that light emitted from the DVDLD unit 56 passes through the wavelength prism 64, becomes parallel light by the collimator lens 65, and is reflected at 90 ° by the rising mirror 66. Have been. The reflected light is incident on the objective lens 41, and after being reflected by the disk, returns on the same optical path. The light emitted from the CDLD unit 59 is reflected by the wavelength prism 64, and follows the same optical path as the DVDLD unit 56, and returns to the CDLD unit 59.

  The optical pickup having the above-described configuration is configured such that the unit holding spring 63 is formed in a direction 43b perpendicular to the disk, and is held down in the optical axis direction so as to cover the shield case 58 fixed to the back of the DVDLD unit 56.

In FIG. 6, reference numeral 52 denotes an optical table, 56 denotes a DVDLD unit which is mounted so as to be rotatable around the optical axis, and a flexible substrate unit 55 is folded at 180 ° on the back surface of the DVDLD unit 56. A high-frequency module substrate 57 is mounted on the flexible substrate unit 55 on the rear surface, 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, but are pressed against the optical bench 52 in the optical axis direction by a unit pressing spring 63 against the disk from the vertical direction 43 b against the disk. .
JP-A-11-312332

  In the above-described conventional optical pickup, the flexible substrate unit 55 is attached to the optical table 52 from the upper surface side and the lower surface side of the optical table 52, but the flexible substrate unit 55 is pressed by the unit pressing spring 63 from the upper surface side. However, the objective lens driving device is slidable with respect to the optical bench 52, and the overall height of the optical pickup changes by sliding. Further, the flexible substrate unit 55 is fixed to the lower surface side of the optical bench 52 without restriction in the vertical direction 43b with respect to the disk.

  In view of the above-described conventional problems, the present invention provides a pressing spring A in which an actuator base is fixed to an optical table and is attached so as to hold a part of the flexible substrate unit on the upper surface side of the optical table while holding the flexible substrate unit. A holding spring B which is provided substantially on the back side of the holding spring A and is attached to the lower surface side of the optical bench so as to hold a part of the flexible substrate unit so as to be held therebetween. An object of the present invention is to provide an ultra-thin optical pickup by controlling the height of the upper surface by holding the holding spring A.

  In order to solve this problem, an optical pickup according to the present invention comprises: an objective lens; an objective lens driving device capable of moving the objective lens in two axes, that is, a vertical direction and a radial direction with respect to a disk; a DVDLD unit; A light emitting side, a flexible substrate mountable in the back direction, a high-frequency module substrate mounted on the flexible substrate, a shield case for shielding the high-frequency module substrate, and a light emitting side of the DVDLD unit. Means a flexible board unit on which the high-frequency module board is mounted in the rear direction, and a flexible board unit fixed by the shield case so as to cover the high-frequency module board, and the DVDLD unit has an optical axis in a light emission side direction. Light rotatably mounted as a central axis A table, a unit pressing spring fixed to the optical table so as to press down the shield case in the optical axis direction so that the DVDLD unit does not fall off, and light emitted from the DVDLD unit is incident on the optical table to the objective lens. An optical system, an actuator base substantially integrally fixed to the optical bench so as to substantially cover the objective lens driving device, and a substantially planar portion other than the actuator base on the upper surface side of the optical bench. A holding spring A attached to the optical table so as to hold a part of the flexible substrate unit in a side-by-side manner; Attached to the optical bench so that a part of the flexible substrate unit is held in a substantially flat part on the lower surface side and held It has been a pressing spring B, and in which a part of the optical bench was configured to secure the flexible substrate unit by holding the pressing spring A in the optical bench.

  Thereby, a part of the optical bench holds the pressing spring A and regulates the height on the upper surface side, so that an ultra-thin optical pickup can be provided.

  According to the present invention, the holding spring A is screwed to the optical bench at the mounting portion, and at the same time, a part of the pressing spring A on the opposite side is clamped by the projection and the substantially flat portion of the optical bench. Thus, the optical pick-up is almost closely fixed to the optical base together with the flexible substrate, and the holding spring A does not rise due to the reaction force of the flexible substrate, so that a thin optical pick can be realized.

  The present invention provides an objective lens, an objective lens driving device capable of moving the objective lens in two axes, that is, a vertical direction and a radial direction with respect to a disk, a DVDLD unit, and the DVDLD unit, which is arranged such that the light exit side is in a rear direction. A mountable flexible board, a high-frequency module board mounted on the flexible board, a shield case for shielding the high-frequency module board, and a light-emitting side of the DVDLD unit in a rearward direction of the high-frequency module board. A flexible board unit, which is fixed by the shield case so as to cover the high-frequency module board by folding the flexible board unit on which the DVDLD unit is mounted, and the DVDLD unit is attached so as to be rotatable around the optical axis in the light emission side direction. Optical table and the DVDLD unit A unit pressing spring fixed to the optical table so as to press the shield case in the optical axis direction, and an optical system configured to make the light emitted from the DVDLD unit enter the objective lens on the optical table. An actuator base substantially integrally fixed to the optical bench so as to substantially cover the objective lens driving device, and a part of the flexible substrate unit on a substantially planar portion other than the actuator base on the upper surface side of the optical bench. A presser spring A attached to the optical table so as to be held in the same direction; A holding spring B attached to the optical bench so as to hold a part of the substrate unit side by side; The portion is configured to fix the flexible substrate unit to the optical bench by holding the holding spring A, and a part of the optical base holds the holding spring A. By regulating the height of the upper surface, an ultra-thin optical pickup can be provided.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

  1 and 2 are exploded perspective views showing an 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, and 2 denotes a lens holder for holding the objective lens 1. The lens holder 2 includes magnets 3a and 3b magnetized in the same direction as the tangential direction 14 with respect to the disk. Are fixed at positions 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 cantileverly holding the lens holder 2 are fixed to the spring substrates 4a and 4b by soldering. The metal wire springs 5a to 5d are fixed to the damping support plate 7 integrally formed with the suspension holder 6 by soldering through the suspension holder 6 and are fixed ends. The lens holder 2 is movable in two axial directions, that is, a vertical direction 16 and a radial direction 17 with respect to the disk.

  A bobbin 8 is attached to the actuator base 9 very close to the magnets 3a and 3b. On the bobbin 8, a focus coil 10 is wound directly on an axis in a direction 16 perpendicular to the disk, and a tracking coil 11 is wound directly on an axis in a radial direction 17 on the disk. When a current flows through each of the focus coil 10 and the tracking coil 11, the lens holder 2 moves in a direction 16 and a radial direction 17 perpendicular to the disk. The start and end of each 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. Further, a counterweight 13 and a lens protector 14 for protecting the objective lens 1 and the disk when the objective lens 1 collides with the disk in order to maintain the balance are fixed to the lens holder 2.

  The suspension holder 6 is fixed to an actuator base 9. 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. After adjusting and fixing the objective lens driving device 18, the leg 8 a of the bobbin 8, which is a part of the objective lens driving device 18, opposite to the actuator base 9 is fixed to the optical bench 18. A prism 20, a collimator lens 21, a holographic 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 mounted so as to be movable in the tangential direction 15. I have.

  A DVDLD unit 25 is mounted on the flexible substrate unit 24 in a direction opposite to the laser emission direction, and a high-frequency module substrate 26 is also mounted. The high-frequency module substrate 26 is foldable on the rear side of the DVDLD unit 25, and is covered and fixed by a shield case 27 so as to cover the high-frequency module substrate 26. In addition, a CDLD unit 28 is mounted on the flexible substrate unit 24 in the laser emission direction. A CDM adjustment plate 29 is provided on the back surface opposite to the laser emission direction, and a CDM adjustment plate 29 is provided on the laser emission side. The holder 30 is fixed.

  The flexible substrate unit 24 is mounted on the optical bench 19 such that the DVDLD unit 25 is rotatable about the optical axis in a plane parallel to the disk and tilted from the tangential direction 15 of the disk. It is mounted 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 long unit holding springs A31 and B32 formed within the thickness of the optical bench 19, respectively. ing. The unit holding spring A31 is fixed to the optical base 19 in a cantilever manner. It has a shape 31a, and the convex portion 31a contacts and presses so as to fit into the concave groove 27a provided in the shield case 27. In order to prevent the flexible board unit 23 from floating, two pressing springs A33 and B34 are attached to the optical table 19 at the mounting portions 33a and 34a, respectively, so as to sandwich the optical table 19 from a plane 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.

  The light emitted from the DVDLD unit 25 and the CDLD unit 28 is reflected and transmitted by the prism 20 to become parallel light by the collimator lens 21. It is bent to 16 and is incident on the objective lens 1.

  In the above configuration, the unit holding spring A31 is cantilevered to the optical bench 19, but the L-shaped projection 19a provided on the optical bench 19 presses the fixed end 31b of the unit holding spring A30 against the fixed end 31b. Since the unit (protrusion 31a) is held so as to hold the intermediate portion, the unit holding spring A31 is temporarily fixed and self-held by the spring pressure of the unit holding spring A31 itself, and the workability when fixing to the optical bench 19 with screws or the like is greatly improved. This is particularly effective when the optical bench 19 is made of zinc or the like having a creep characteristic, for example, since the fixing force can be reduced by half, and the screw tightening torque can be set low.

  The pressing spring A33 is screwed to the optical bench 19 at the mounting portion 33a, and at the same time, a part 33b on the substantially opposite side is sandwiched between the projection 19b and the substantially flat portion 19c of the optical bench 19. Therefore, the optical pick-up is almost closely fixed to the optical base 18 together with the flexible board 24, and the holding spring A33 does not rise due to the reaction force of the flexible board 24, so that a thin optical pick can be realized.

  Further, the objective lens driving device 18 is adjusted and fixed to the optical bench 19, and the leg 8 a of the bobbin 8, which is a part of the objective lens driving device 18, opposite to the portion fixed to the actuator base 9 is fixed to the optical bench 19. Therefore, the bobbin 8 functions as a column connecting the actuator base 9 located on the upper surface of the optical pick and the optical base 19 located on the lower surface, and the actuator base 9 and the optical base 19 may be directly fixed. To achieve a solid three-dimensional structure. In addition, since the bobbin 8 itself is firmly fixed up and down, no harmful vibration or displacement is generated by the reaction force received from the magnets 3a and 3b when the objective lens is driven, and an optical pick that does not impair the original characteristics is provided. It can be realized.

  FIG. 4 is a partial perspective view of a bent portion 9b having substantially the same shape as the bent portion 9a located substantially opposite to the bent portion 9a in the actuator base 9 and a part 19d of the optical bench 19 viewed from an arrow A. 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. Although it is fixed, as shown in FIG. 4, a structure is provided on the outer wall portion 19d of the optical bench 19 where the adhesive easily accumulates. Therefore, it is necessary to use a sufficient adhesive so as to wrap the bending leg 9b of the actuator base 9. This makes it possible to realize a highly reliable light pick that does not cause the adhesive to flow into the optical bench 19.

  The optical pickup of the present invention can easily achieve an ultra-thin configuration.

Exploded perspective view showing an optical pickup according to Embodiment 1 of the present invention. 1 is a perspective view showing an optical pickup according to a first embodiment of the present invention. 1 is a perspective view showing an optical pickup according to a first embodiment of the present invention. FIG. 3 is a partially exploded perspective view showing the optical pickup according to the first embodiment of the present invention. Exploded perspective view showing a conventional optical pickup Perspective view showing a conventional optical pickup

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 Objective lens 2 Lens holder 3 Magnet 6 Sus holder 8 Bobbin 9 Actuator base 15 Tangential direction 16 Vertical direction 17 Radial direction 18 Objective lens driving device 19 Optical table 24 Flexible board unit 25 DVDLD unit 26 High frequency module substrate 27 Shield case 31 Unit press Spring A
32 Unit holding spring B
33 Holding Spring A
34 Holding Spring B

Claims (1)

An objective lens, an objective lens driving device capable of moving the objective lens in two directions perpendicular and radial to the disc, a DVDLD unit, and a flexible mountable DVD drive unit with the DVDLD unit mounted on the back side. A substrate, a high-frequency module substrate mounted on the flexible substrate, a shield case for shielding the high-frequency module substrate, and a flexible board on which the light-emitting side of the DVDLD unit has the high-frequency module substrate mounted in a rear direction. A flexible board unit which is fixed by the shield case so as to cover a high-frequency module board by folding a board unit, and an optical table on which the DVDLD unit is mounted so as to be rotatable around an optical axis in a light emission side direction. So that the DVDLD unit does not fall off. A unit pressing spring fixed to the optical bench so as to press the mold case in the optical axis direction, an optical system configured to make the light emitted from the DVDLD unit incident on the optical bench to the objective lens, and the objective lens An actuator base substantially integrally fixed to the optical bench so as to substantially cover the driving device, and a part of the flexible substrate unit being directed to a substantially flat portion other than the actuator base on the upper surface side of the optical bench. A holding spring A attached to the optical bench so as to be nipped; and a substantially flat portion on the lower surface side of the optical bench similarly to the holding spring A, which is formed on the back side of the holding spring A. A holding spring B attached to the optical bench so as to hold the optical bench partially, wherein a part of the optical bench is Optical pickup is characterized by being configured to secure the flexible substrate unit to the optical bench by even sandwiching the spring A.

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