WO2013077272A1

WO2013077272A1 - Objective lens holder, objective lens drive device, and optical pickup device

Info

Publication number: WO2013077272A1
Application number: PCT/JP2012/079820
Authority: WO
Inventors: 明飯島
Original assignee: 三洋電機株式会社
Priority date: 2011-11-21
Filing date: 2012-11-16
Publication date: 2013-05-30
Also published as: JP2015026402A

Abstract

[Problem] To heighten the resonance frequency of an objective lens holder and reduce the resonance gain. [Solution] The present invention comprises: a rectangular holder plate in which the objective lens is held; planar first and second tripod plates that rise in the same direction from the opposing two sides of the holder plate, each of which tripod plates having mounted thereon coils for displacing the objective lens in at least one of the focusing direction or the tracking direction; and a reinforcing plate for the holder plate and the first and second tripod plates, the reinforcing plate being mounted on the surfaces of the sides enclosed by the holder plate and the first and second tripod plates.

Description

Objective lens holder, objective lens driving device, optical pickup device

The present invention relates to an objective lens holder objective lens driving device and an optical pickup device.

For example, when the objective lens holder that holds the objective lens is displaced in the focus direction, resonance occurs in which the objective lens holder vibrates. In this case, the accuracy of displacing the objective lens is lowered, and there is a possibility that good information reading from the optical disk may be hindered. Therefore, a technique is known that includes a reinforcing plate for increasing the resonance frequency by increasing the rigidity of the objective lens holder. (Patent Document 1)

JP 2009-271961 A

Generally, in an objective lens holder, in order to read good information from an optical disk, it is desirable to increase the resonance frequency and decrease the resonance gain. However, the objective lens holder disclosed in Patent Document 1 is provided with a reinforcing plate, but the rigidity of the objective lens holder is increased and the resonance gain is increased. In that case, there is a possibility that good reading of information from the optical disk may be hindered.

The main present invention for solving the above-described problems is that a rectangular holding plate for holding an objective lens and two opposite sides of the holding plate rise in the same direction, and the objective lens is moved to at least one of a focus direction and a tracking direction. A flat plate-like first and second leg plate to which coils for displacing in the direction are respectively attached, and the holding plate and the first and second leg plates of the holding plate and the first and second leg plates. A reinforcing plate attached to a surface on the surrounded side, wherein the reinforcing plate includes first and second reinforcing portions that respectively oppose the first and second leg plates, and a third reinforcing portion that opposes the holding plate. The third reinforcing portion is bonded to the holding plate with a first adhesive, and the first and second reinforcing portions are the first and second leg plates, respectively. From the hardness of the first adhesive It is an objective lens holder, characterized in that it is bonded with the second adhesive with low hardness.

Other features of the present invention will become apparent from the accompanying drawings and the description of the present specification.

According to the present invention, the resonance frequency of the objective lens holder can be increased and the resonance gain can be reduced.

It is a figure which shows the structure of the optical system of the optical pick-up apparatus in embodiment of this invention. It is a figure which shows the structure of a part of optical system of the optical pick-up apparatus in embodiment of this invention. It is a disassembled perspective view which shows the optical pick-up apparatus in embodiment of this invention. It is a perspective view which shows the lens holder seen from the side which the objective lens in embodiment of this invention exposes. It is a perspective view which shows the lens holder seen from the side which the leg plate in the embodiment of this invention stands up. It is a perspective view which shows the reinforcement board seen from the side facing the holding | maintenance board in embodiment of this invention. It is a perspective view which shows the reinforcement board seen from the opposite side to the side which opposes the holding | maintenance board in embodiment of this invention. It is a side view which shows the reinforcement board and standing mirror in embodiment of this invention. It is sectional drawing which shows the lens holder in embodiment of this invention. It is a characteristic view which shows the relationship between the resonant frequency and gain in embodiment of this invention.

At least the following matters will become clear from the description of this specification and the accompanying drawings.

[First embodiment]
=== Optical System of Optical Pickup Device ===
FIG. 1 is a diagram illustrating a configuration of an optical system of the optical pickup device according to the present embodiment. FIG. 2 is a diagram illustrating a partial configuration of an optical system of the optical pickup device according to the present embodiment.
The optical pickup device 100 is a device that irradiates a rotating optical disk with laser light and detects return light of the laser light reflected by the optical disk. The optical pickup device 100 is mounted on an information recording / reproducing device such as an optical disc device (not shown). The optical discs on which information is recorded or reproduced by the optical pickup device 100 are, for example, BD (Blu-ray Disc) standard optical disc (hereinafter referred to as “first optical disc 5A”), DVD (Digital Versatile Disc) standard. An optical disc (hereinafter referred to as “second optical disc 5B”), a CD (Compact Disc) standard optical disc (hereinafter referred to as “third optical disc 5C”), and the like. The optical pickup device 100 includes a first optical system along the optical path of the first laser light applied to the second optical disc 5B and the third optical disc 5C, and the optical path of the second laser light applied to the first optical disc 5A. A second optical system.
Details of the first optical system and the second optical system will be described later.

=== First optical system ===
Hereinafter, the first optical system of the optical pickup device in the present embodiment will be described with reference to FIGS. 1 to 3. FIG. 3 is an exploded perspective view showing the optical pickup device in the present embodiment. Note that the center axis of the rotation axis (not shown) of the spindle motor is indicated by a dashed line for convenience of explanation. The first half-wave plate 13, the second diffraction grating 22, the second half-wave plate 23, the first focus coil 74, the second focus coil 75, and the tracking coil 76 are in an invisible state.

The first optical system is an optical system for DVD standard and CD standard, and includes a first laser light source 110, a first diffraction grating 12, a first half-wave plate 13, a beam splitter 32, a collimating lens 33, 1 / Four wavelength plate 34, reflection mirror 35, first rising mirror 15 (rising mirror), first objective lens 16 (objective lens), coupling lens 24, half mirror 36, detection lens 37, photodetector 38, front An optical element such as a monitor diode 31 is included.

The first laser light source 110 has a wavelength of, for example, 655 nm in the red wavelength band (645 nm to 675 nm) irradiated to the second optical disc 5B and a wavelength of, for example, 785 nm in the infrared wavelength band (765 nm to 805 nm) irradiated to the third optical disc 5C. The first laser beams having two different wavelengths are selectively generated. The first laser light source 110 includes, for example, a first laser diode 11A (laser diode) that generates a first laser beam having a wavelength of 655 nm, and a first laser diode 11B (laser diode) that generates a first laser beam having a wavelength of 785 nm, for example. ) Is built in the first holder 17 (FIG. 3).

The first diffraction grating 12 generates 0th order light, + 1st order diffracted light, and −1st order diffracted light from the first laser light generated by the first laser light source 110.
The first half-wave plate 13 converts, for example, first laser light that is S-polarized linearly polarized light into P-polarized linearly polarized light.

The beam splitter 32 transmits, for example, P-polarized laser light in the red wavelength band and infrared wavelength band, and reflects laser light other than P-polarized light in the red wavelength band and infrared wavelength band. The beam splitter 32 transmits the P-polarized first laser light in the red wavelength band or the infrared wavelength band incident from the first half-wave plate 13. At this time, the beam splitter 32 reflects a part of the first laser light in the direction of the front monitor diode 31 in order to adjust the intensity of the first laser light. The front monitor diode 31 is an optical element that adjusts the intensity of the first laser light by allowing a part of the first laser light to enter from the beam splitter 32. The return light of the first laser light incident from the collimator lens 33 is reflected by, for example, the second optical disk 5B or the third optical disk 5C and becomes S-polarized laser light. The return light of the laser light is reflected in the direction of the coupling lens 24.

The collimating lens 33 converts the first laser light incident from the beam splitter 32 into parallel light.

The quarter-wave plate 34 converts the first laser light incident from the collimator lens 33 from linearly polarized light to circularly polarized light. The quarter-wave plate 34 converts the return light of the first laser light incident from the reflection mirror 35 from circularly polarized light to linearly polarized light.

The reflection mirror 35 reflects the first laser beam incident from the quarter wavelength plate 34 in the direction of the first rising mirror 15. The reflection mirror 35 reflects the return light of the first laser light incident from the first rising mirror 15 in the direction of the quarter wavelength plate 34.

The first rising mirror 15 reflects the first laser beam incident from the reflection mirror 35 in a direction perpendicular to the recording surface of the second optical disc 5B or the third optical disc 5C. The first rising mirror 15 reflects the return light of the first laser light incident from the first objective lens 16 in the direction of the reflection mirror 35.

The first objective lens 16 focuses the first laser light incident from the first rising mirror 15 on the signal recording layer on the recording surface of the second optical disc 5B or the third optical disc 5C.

The return light of the first laser beam reflected by the signal recording layer of the second optical disc 5B or the third optical disc 5C is converted into parallel light by the first objective lens 16, and then passed through the first rising mirror 15 and the reflection mirror 35. Then, the light enters the quarter wavelength plate 34 and is converted from circularly polarized light into linearly polarized light by the quarter wavelength plate 34. The return light of the first laser light that has become linearly polarized light is incident on the coupling lens 24 via the collimating lens 33 and the beam splitter 32.

The coupling lens 24 converts the convergence angle of the return light of the first laser light incident from the beam splitter 32 so that the return light of the first laser light can be received by the photodetector 38.

For example, the half mirror 36 reflects S-polarized laser light in the blue wavelength band and transmits laser light other than S-polarized light in the blue wavelength band. Details of the blue wavelength band will be described later. The return light of the first laser light incident from the coupling lens 24 is S-polarized laser light in the red wavelength band or the infrared wavelength band, and the half mirror 36 returns the first laser light incident from the coupling lens 24. Transmits light.

The detection lens 37 condenses the return light of the first laser light incident from the half mirror 36 on the photodetector 38 and generates astigmatism in the return light of the first laser light to generate a focus error signal. Generate. For example, a cylindrical surface, a flat surface, a concave curved surface, or a convex curved surface is formed on the incident surface side or the outgoing surface side of the detection lens 37. In this embodiment, the detection lens 37 has a parallel plate astigmatism. Inclined in a predetermined direction in consideration of the generation direction of
The light detector 38 photoelectrically converts the return light of the first laser light incident from the detection lens 37.

=== Second optical system ===
Hereinafter, the second optical system of the optical pickup device in the present embodiment will be described with reference to FIGS. 1 to 3.

The second optical system is an optical system for the BD standard, and includes a second laser light source 210, a second diffraction grating 22, a second half-wave plate 23, a half mirror 36, a coupling lens 24, a beam splitter 32, Optical elements such as a collimating lens 33, a quarter-wave plate 34, a reflecting mirror 35, a second rising mirror 25, a second objective lens 26 (objective lens), a detection lens 37, a photodetector 38, and a front monitor diode 31 are provided. Consists of including. For example, the half mirror 36, the coupling lens 24, the beam splitter 32, the collimating lens 33, the quarter wavelength plate 34, the reflection mirror 35, the detection lens 37, the photodetector 38, and the front monitor diode 31 are the first optical. It is used in common for the system and the second optical system.

The second laser light source 210 is different from the wavelength of the first laser light generated by the first laser light source 110, and is a second laser having a wavelength of, for example, 405 nm in the blue wavelength band (400 nm to 420 nm) irradiated to the first optical disc 5A. Light is generated complementary to the first laser light. The second laser light source 210 is formed by incorporating, for example, a second laser diode (laser diode) 21 that generates a second laser beam having a wavelength of 405 nm in the second holder 27 (FIG. 3).

The second diffraction grating 22 generates 0th-order light, + 1st-order diffracted light, and −1st-order diffracted light from the second laser light generated by the second laser light source 210.

The second half-wave plate 23 converts, for example, second laser light, which is P-polarized linearly polarized light, into S-polarized linearly polarized light.

The half mirror 36 reflects the S-polarized second laser light in the blue wavelength band incident from the second half-wave plate 23 in the direction of the coupling lens 24. Further, since the return light of the second laser light incident from the coupling lens 24 is reflected by the first optical disk 5A to become P-polarized laser light, for example, the half mirror 36 returns the second laser light. Transmits light.

The coupling lens 24 converts the divergence angle of the second laser light incident from the half mirror 36 so that the second laser light is focused on the signal recording layer of the first optical disc 5A. Further, the coupling lens 24 converts the convergence angle of the return light of the second laser light incident from the beam splitter 32 so that the return light of the second laser light can be received by the photodetector 38.

The second laser light incident from the coupling lens 24 is, for example, an S-polarized laser light in a blue wavelength band other than the P-polarized light in the red wavelength band and the infrared wavelength band, so that the beam splitter 32 is incident from the coupling lens 24. The second laser beam to be reflected is reflected in the direction of the collimating lens 33. At this time, the beam splitter 32 transmits a part of the second laser light in order to adjust the intensity of the second laser light. The front monitor diode 31 is an optical element that adjusts the intensity of the second laser light by allowing a part of the second laser light to enter from the beam splitter 32. The return light of the second laser light incident from the collimating lens 33 is, for example, a P-polarized laser light in a blue wavelength band other than the P-polarized light in the red wavelength band and the infrared wavelength band. The return light of the second laser light incident from 33 is reflected in the direction of the coupling lens 24.

The second laser light reflected by the beam splitter 32 in the direction of the collimating lens 33 is converted into parallel light by the collimating lens 33 and then converted from linearly polarized light to circularly polarized light by the quarter wavelength plate 34. The second laser light that has become circularly polarized light is reflected by the reflecting mirror 35 toward the second rising mirror 25. The first rising mirror 15 disposed between the reflecting mirror 35 and the second rising mirror 25 in the optical path of the second laser light reflects the laser light in the red wavelength band and the infrared wavelength band, It is assumed that the laser beam in the blue wavelength band is transmitted.

The second rising mirror 25 reflects the second laser light incident from the reflection mirror 35 in a direction perpendicular to the recording surface of the first optical disc 5A. The second rising mirror 25 reflects the return light of the second laser light incident from the second objective lens 26 in the direction of the reflection mirror 35.

The second objective lens 26 focuses the second laser light incident from the second rising mirror 25 on the signal recording layer on the recording surface of the first optical disc 5A.

The return light of the second laser beam reflected by the signal recording layer of the first optical disc 5A is converted into parallel light by the second objective lens 26, and then 1/2 via the second rising mirror 25 and the reflection mirror 35. The light enters the four-wave plate 34 and is converted from circularly polarized light into linearly polarized light by the quarter-wave plate 34. The return light of the second laser light that has become linearly polarized light is incident on the detection lens 37 via the collimating lens 33, the beam splitter 32, the coupling lens 24, and the half mirror 36.

The detection lens 37 condenses the return light of the second laser light incident from the half mirror 36 on the photodetector 38 and generates astigmatism in the return light of the second laser light to generate a focus error signal. Generate.

The photodetector 38 photoelectrically converts the return light of the second laser light incident from the detection lens 37.

=== Optical Pickup Device ===
Hereinafter, the optical pickup device in the present embodiment will be described with reference to FIG.
The optical pickup device 100 includes a housing 50, an actuator 6, a lens holder 67 (objective lens holder), an optical element of a first optical system, and an optical element of a second optical system. In the present embodiment, the Z-axis is an axis along the longitudinal direction (focus direction, vertical direction) of the rotation axis of the spindle motor that rotates the optical disc 5, and the downward direction is defined as the + Z direction. Let the direction be the -Z direction. Of the first optical disc 5A, the second optical disc 5B, and the third optical disc 5C, the optical disc rotated by the spindle motor is referred to as the optical disc 5 for convenience of explanation. The Y axis is an axis along the direction in which the optical pickup device 100 moves in the radial direction (tracking direction, radial direction) of the optical disc 5, the direction away from the rotation axis is the + Y direction, and the direction approaching the rotation axis is the -Y direction. And The X axis is an axis along the tangential direction, and a direction from the outside of the housing 50 toward the side surface 530 is defined as a −X direction, and a direction from the outside of the housing 50 toward the side surface 540 is defined as a + X direction.

The lens holder 67 holds the first objective lens 16 and the second objective lens 26. First focus coils 71 and 74, second focus coils 72 and 75, and tracking

coils

73 and 76 are attached to the lens holder 67. The first focus coils 71 and 74 are a pair of coils wound with a single conductive wire to which a focus for displacing the lens holder 67 in the focus direction is supplied. The second focus coils 72 and 75 are a pair of coils wound with one conductive wire to which a focus signal for displacing the lens holder 67 in the focus direction is supplied. The tracking coils 73 and 76 are a pair of coils wound with a single conductive wire to which a tracking signal for displacing the lens holder 67 in the tracking direction is supplied. Details of the lens holder 67, the first focus coils 71 and 74, the second focus coils 72 and 75, and the tracking coils 73 and 76 will be described later.

Actuator 6 displaces lens holder 67 in the focus direction and tracking direction. That is, the actuator 6 displaces the first objective lens 16 and the second objective lens 26 in the focus direction and the tracking direction. The actuator 6 includes a frame 63,

suspension wires

64 and 65,

magnets

66 and 68, and a control board 69. The actuator 6, the lens holder 67, the first objective lens 16, the second objective lens 26, and the coil correspond to an objective lens driving device.

Magnets

66 and 68 are magnetic bodies that generate magnetic flux for displacing the lens holder 67 in the focus direction and the tracking direction. The magnet 66 is attached to the frame 63 so as to face the frame 63 side (−X side) surface of the lens holder 67 when the actuator 6 and the lens holder 67 are accommodated in the housing 50. The magnet 68 is disposed on the bottom surface of the housing 50 through the opening 202 so as to face the surface of the lens holder 67 opposite to the frame 63 when the actuator 6 and the lens holder 67 are accommodated in the housing 50. The opening 202 will be described later.

The control board 69 is a board that outputs a focus signal and a tracking signal, and is attached to the end of the frame 63 opposite to the magnet 66.

The

suspension wires

64 and 65 elastically support the lens holder 67 with respect to the frame 63 so that the lens holder 67 can be displaced in the tracking direction and the focus direction. The

suspension wires

64 and 65 are signal lines for transmitting a focus signal and a tracking signal for displacing the lens holder 67 in the tracking direction and the focus direction. Each of the

suspension wires

64 and 65 has, for example, three wires. One end of each of the

suspension wires

64 and 65 is bonded to

auxiliary members

62A and 62B attached to the frame 63, and is electrically connected to the control board 69 using, for example, solder. The other ends of the

suspension wires

64 and 65 are bonded to the surface of the lens holder 67 on the frame 63 side, and soldered to the first focus coils 71 and 74, the second focus coils 72 and 75, and the tracking coils 73 and 76, for example. Etc. are electrically connected. For example, the other ends of the upper and lower suspension wires of the suspension wire 64 are connected to both ends of the pair of first focus coils 71 and 74, respectively. For example, the other ends of the upper and lower suspension wires of the suspension wire 65 are connected to both ends of the pair of second focus coils 72 and 75, respectively. The other ends of the suspension wires at the center of the

suspension wires

64 and 65 are connected to both ends of the tracking coils 73 and 76, respectively.

The housing 50 is, for example, a resin container for housing the optical element of the first optical system, the optical element of the second optical system, the first holder 17, the second holder 27, the actuator 6, and the lens holder 67. In the housing 50, the optical element of the first optical system, the optical element of the second optical system, the first holder 17, and the second holder 27 (hereinafter referred to as “optical element etc.”) are disposed from the upper side, for example. An opening 201 is formed for placement and accommodation. The housing 50 is formed with an opening 202 for accommodating the actuator 6 and the lens holder 67, for example, arranged from above on the inside of the housing 50. The side surface of the housing 50 on the side of the spindle motor has, for example, a shape bent with a predetermined curvature so as to avoid the spindle motor. A guide member 53 is provided on the side surface 530 of the housing 50, and guide members 54 A and 54 B are provided on the side surface 540. The guide members 53, 54 A, and 54 B are members for attaching the optical pickup device 100 to a pair of guide shafts for moving the optical pickup device 100 along the radial direction of the optical disc 5. On the bottom surface of the housing 50, an optical element or the like is disposed from above through the opening 201 so as to have the positional relationship described with reference to FIGS. On the bottom surface of the housing 50, the actuator 6 and the lens holder 67 are disposed from above through the opening 202.

=== Lens holder ===
Hereinafter, the lens holder in the present embodiment will be described with reference to FIGS. 3 to 5.
FIG. 4 is a perspective view showing the lens holder viewed from the side where the objective lens is exposed in the present embodiment. The first focus coil 74, the second focus coil 75, the tracking coil 76, and the

coil bobbins

74A, 75A, 76A are in an invisible state. FIG. 5 is a perspective view showing the lens holder as viewed from the side where the leg plate rises in the present embodiment. The tracking coil 76 is not visible. A center line P1 between the two long sides of the holding plate 671 is indicated by a dotted line.

The lens holder 67 includes the first objective lens 16 and the second objective lens so that the first objective lens 16 and the second objective lens 26 are disposed above the first rising mirror 15 and the second rising mirror 25, respectively. The lens 26 is held. The lens holder 67 includes a holding plate 671, a leg plate 672 (first leg plate), a leg plate 673 (second leg plate), and the reinforcing plate 8. The holding plate 671 and the

leg plates

672 and 673 are integrally formed using, for example, resin.

The holding plate 671 is a member for holding the first objective lens 16 and the second objective lens 26. The holding plate 671 is a plate member having a rectangular shape having, for example, a long side along the tracking direction and a short side along the tangential direction. The holding plate 671 holds the first objective lens 16 and the second objective lens 26 so that the first objective lens 16 and the second objective lens 26 are adjacent to each other along the tracking direction, for example.

The leg plate 672 is a flat plate having a rectangular shape, for example. The leg plate 673 is a flat plate having the same shape as the leg plate 672. Each of the

leg plates

672 and 673 extends in the vertical direction (−Z side) from the opposing long sides of the holding plate 671. When the holding plate 671 and the

leg plates

672 and 673 are viewed toward the + Y side along the tracking direction, the holding plate 671 and the

leg plates

672 and 673 are formed to have a U-shape. The

leg plates

672 and 673 are formed to be line symmetric with respect to the center line P1.

A first focus coil 71, a second focus coil 72, and a tracking coil 73 are attached to the leg plate 672. A first focus coil 74, a second focus coil 75, and a tracking coil 76 are attached to the leg plate 673. Each of the first focus coils 71 and 74 has one

coil bobbin

71A and 74A provided on the surface facing the outside of the leg plate 672 (+ X side) and the surface facing the outside of the leg plate 673 (−X side). It is formed by winding a conductive wire. Each of the second focus coils 72 and 75 has one conductive line for the

coil bobbins

72A and 75A provided on the surface facing the outside of the leg plate 672 (+ X side) and the surface facing the outside of the leg plate 673 (−X side). It is formed by winding. Each of the tracking coils 73 and 76 has one conductive wire wound around

coil bobbins

73A and 76A provided on the surface facing the outside of the leg plate 672 (+ X side) and the surface facing the outside of the leg plate 673 (−X side). Formed by turning. The first focus coil 71 and the second focus coil 72 are provided on the leg plate 672 so as to be symmetrical about the tracking coil 73 along the tracking direction. The first focus coil 74 and the second focus coil 75 are provided on the leg plate 672 so as to be symmetrical about the tracking coil 76 along the tracking direction.

The reinforcing plate 8 is a plate member that reinforces the lens holder 67 and increases the resonance frequency. Details of the resonance frequency and the reinforcing plate 8 will be described later.

=== resonance, resonance frequency ===
Hereinafter, the resonance and the resonance frequency of the lens holder in the present embodiment will be described with reference to FIGS. FIG. 9 is a cross-sectional view of the lens holder in the present embodiment, as viewed from the cross section G1-G2 of FIG. 5 toward the −Y side.

As described above, the lens holder 67 has a shape in which the −Z side of the lens holder 67 is opened so as to have a U shape. For example, when the lens holder 67 is displaced in the focus direction or the tracking direction, the manner in which magnetic flux is applied to the first focus coils 71 and 74, the second focus coils 72 and 75, and the tracking coils 73 and 76 changes, and the lens holder 67, an electromagnetic force may be applied in a direction other than the focus direction. In that case, in the

leg plates

672 and 673, the end portions on the −Z side of the

leg plates

672 and 673 are close to each other with the joint portion between the leg plate 672 and the holding plate 671 and the joint portion between the leg plate 672 and the holding plate 671 as fulcrums. A vibration such as separation (a dashed-dotted arrow in FIG. 9) occurs. When the

leg plates

672 and 673 of the lens holder 67 vibrate, the displacement amounts W1 and W2 at which the ends of the −Z side of the

leg plates

672 and 673 are displaced along the tangential direction are respectively determined as vibration amplitudes (gains). And The vibrations of the

leg plates

672 and 673 resonate when the focus signals transmitted to the first focus coils 71 and 74 and the second focus coils 72 and 75 have a predetermined frequency, for example. The frequency of the focus signal when resonating is the resonance frequency. When the lens holder 67 resonates, the vibration gain of the

leg plates

672 and 673 is increased, the accuracy of displacing the lens holder 67 is lowered, and reading of good information from the optical disk 5 may be hindered. Therefore, it is necessary to shift the resonance frequency to a frequency band (for example, 20 kHz or more) higher than the frequency band normally used as the frequency of the focus signal. Furthermore, it is necessary to reduce the resonance gain shifted to a high frequency band so that good information reading is not prevented when the optical disk 5 is read in the double speed mode.

=== Reinforcing plate ===
Hereinafter, with reference to FIG. 4 thru | or FIG. 8, the reinforcement board in this embodiment is demonstrated. FIG. 6 is a perspective view showing the reinforcing plate viewed from the side facing the holding plate in the present embodiment. FIG. 7 is a perspective view showing the reinforcing plate viewed from the side opposite to the side facing the holding plate in the present embodiment. FIG. 8 is a side view showing the reinforcing plate and the upright mirror in the present embodiment. A part of the first rising mirror 15 is invisible, but is indicated by a one-dot chain line. The reinforcing

portions

812, 814, 822, 841 to 844 are invisible.

The reinforcing plate 8 is a plate member that reinforces the lens holder 67. The reinforcing plate 8 is a surface on the side opposite to the surface where the first objective lens 16 and the second objective lens 26 of the holding plate 671 and the second objective lens 26 are exposed to the outside (−Z side), and the side opposite to the surface where the coil of the leg plate 672 is exposed. Is attached to the inner surface of the holding plate 671 and the

leg plates

672 and 673 surrounded by the surface (−X side) of the leg plate 673 and the surface opposite to the surface of the leg plate 673 where the coil is exposed (+ X side). The reinforcing plate 8 is an integrated plate that has a line-symmetric shape with respect to the center line P1 between the two long sides of the holding plate 671. The reinforcing plate 8 may be formed by bending a metal plate, for example, or may be formed by welding each metal plate. The reinforcing plate 8 has reinforcing portions A, B, and D and a curved arm C.

The reinforcing part A has a substantially U shape along the inner surfaces of the holding plate 671 and the

leg plates

672 and 673. The reinforcing part B is provided on the −Y side of the reinforcing part A along the tracking direction. The reinforcing portion B extends between the

leg plates

672 and 673 along the inner surface (−Z) of the holding plate 671 toward the side opposite to the reinforcing portion A. What is the reinforcing portion A in the reinforcing portion B? It has a shape bent from the opposite side toward the holding plate 671 in a substantially vertical direction (−Z side). The side of the reinforcing part B opposite to the bent side in the surface along the holding plate 671 and the side of the reinforcing part A that faces the reinforcing part B are integrated. The reinforcement part D is provided on the opposite side (+ Y) of the reinforcement part A to the reinforcement part B along the tracking direction. The reinforcing portion D has a shape along the inner surface of the holding plate 671 such that the height in the vertical direction (Z-axis direction) is the same height as the surface along the inner side of the holding plate 671 in the reinforcing portion A. The reinforcing portions A and D are opposite sides along the tangential direction so that a hole 86 between the reinforcing portions A and D for allowing the first laser light to enter the first objective lens 16 is formed. The both ends of the two are integrated by the bending arm C. Therefore, the reinforcing portions A, B, D, and the curved arm C form an integrated reinforcing plate 8.

The reinforcing portion A includes reinforcing

portions

81, 811, and 812 that face the inner surface (−Z) of the holding plate 671, the inner surface (−X) of the leg plate 672, and the inner surface (+ X) of the leg plate 673, respectively. . The reinforcing part 81 has a substantially rectangular shape. The reinforcing portion 81 is attached to the inner surface of the holding plate 671 between the first objective lens 16 and the second objective lens 26, for example, on the first objective lens 16 side. The details of attaching the reinforcing portion 81 will be described later. For example, when the reinforcing plate 8 is attached to the lens holder 67, the first objective lens 16 on the first objective lens 16 side of the reinforcing portion 81 does not interfere with the optical path of the first laser light incident on the first objective lens 16. Exhibits a shape beaten toward the opposite side. The reinforcing part 812 has a substantially rectangular shape. The reinforcing portion 812 is attached to the inner surface of the leg plate 673 so as to follow the reinforcing portion 81 in the tangential direction. The details of attaching the reinforcing portion 812 will be described later. The side on the holding plate 671 side (+ Z side) of the reinforcing portion 812 is integrated with the side on the reinforcing portion 812 side of the reinforcing portion 814 having a shape along the connecting portion between the holding plate 671 and the leg plate 673, for example. The side of the reinforcing portion 814 on the reinforcing portion 81 side is integrated with the side of the reinforcing portion 81 on the leg plate 673 side (−X side). The reinforcing part 811 has the same shape as the reinforcing part 812. The reinforcing portion 811 is attached to the inner surface of the leg plate 672 so as to be symmetrical with the reinforcing portion 812 with respect to the center line P1. The details of attaching the reinforcing portion 811 will be described later. The side on the holding plate 671 side of the reinforcing portion 811 is integrated with the side on the reinforcing portion 811 side of the reinforcing portion 813 having a shape along the joint portion of the holding plate 671 and the leg plate 672, for example. The side of the reinforcing part 813 on the reinforcing part 81 side is integrated with the side of the reinforcing part 81 on the leg plate 672 side (+ X side).

The reinforcing portion B includes reinforcing

portions

87, 821, and 822 facing the inner surface of the holding plate 671, the inner surface of the leg plate 672, the inner surface of the leg plate 673, and the second objective lens 26 side of the reinforcing portion 87, respectively. The reinforcing portion 82 is bent from the side toward the focus direction (−Z side). The reinforcing part 87 has a rectangular shape. The reinforcing portion 87 is provided between the reinforcing portion 81 and the second objective lens 26 on the inner surface of the holding plate 671. The reinforcing portion 82 is bent from the side of the reinforcing portion 87 on the second objective lens 26 side in a direction away from the holding plate 671 that is substantially perpendicular to the holding plate 671. The reinforcing portion 82 is bent on the second objective lens 26 side from the approximate center of the holding plate 671 in the tracking direction. The reinforcing portion 82 has a shape along the tangential direction between the

leg plates

672 and 673. The details of the angle at which the reinforcing portion 82 is bent will be described later. The side of the reinforcing portion 82 that protrudes from the holding plate 671 toward the −Z side is bent toward the holding plate 671 so as not to obstruct the optical path of the second laser light incident on the second objective lens 26. Presents. The side of the reinforcing part 87 on the reinforcing part 81 side is integrated with the side of the reinforcing part 81 on the reinforcing part 87 side. Here, the length of the side of the reinforcing part 87 on the reinforcing part 81 side is shorter than the length of the side of the reinforcing part 81 on the reinforcing part 87 side. It is assumed that both ends of the side of the reinforcing portion 81 on the reinforcing portion 87 side are exposed by the same length. Therefore, a notch 92A that is continuous between the reinforcing

portions

82 and 812 and between the reinforcing

portions

82 and 81, and a notch 91A that is continuous between the reinforcing

portions

82 and 811 and between the reinforcing

portions

82 and 81 are formed. The reinforcing portion 822 has a substantially rectangular shape and faces the inner surface of the leg plate 673. The reinforcing portion 822 is provided on the side opposite to the direction in which the notch 92A is provided at the end of the reinforcing portion 82 on the leg plate 673 side. The side on the notch 92 A side of the reinforcing portion 822 is integrated with the side on the leg plate 673 side of the reinforcing portion 82. The reinforcing part 821 has the same shape as the reinforcing part 822. The reinforcing portion 821 is provided on the opposite side to the direction in which the notch 91A is provided at the end of the reinforcing portion 82 on the leg plate 672 side so as to be symmetrical with the reinforcing portion 821 with respect to the center line P1. The side on the notch 91 A side of the reinforcing part 821 is integrated with the side on the leg plate 672 side of the reinforcing part 82.

The reinforcing part D has a reinforcing part 85 (fourth reinforcing part) facing the inner surface of the holding plate 671. The reinforcing portion 85 has a substantially rectangular shape. The reinforcing portion 85 is provided on the inner surface of the holding plate 671 between the first objective lens 16 and the + Y side edge of the holding plate 671 (the side opposite to the reinforcing portion 81 of the first objective lens 16). The length of the reinforcing portion 85 in the tangential direction is longer than the diameter of the first objective lens 16. The first objective lens 16 side of the reinforcing portion 85 has a shape that is curled toward the side opposite to the first objective lens 16 so as not to obstruct the optical path of the first laser light incident on the first objective lens 16.

The curved arm C is made by combining the reinforcing portions A and D together. The curved arm C includes reinforcing

portions

831 and 841 having a shape along a surface (+ Z) facing the first objective lens 16 of the first rising mirror 15. When the lens holder 67 is disposed in the housing 50, the first rising mirror 15 faces the first paired lens 16 in a region surrounded by a surface surrounded by the holding plate 671 and the

leg plates

672 and 673. It shall be arranged at a position. The reinforcing portion 841 protrudes toward the reinforcing portion 85 in a state along the surface facing the first objective lens 16 of the first rising mirror 15 from the end on the leg plate 673 side on the side of the reinforcing portion 81 on the reinforcing portion 85 side. Presents a shape The reinforcing portion 841 is coupled to the reinforcing portion 85 by the reinforcing

portions

842 and 844. The reinforcing portion 842 has a shape that is substantially perpendicular to the holding plate 671 from the end on the reinforcing portion 81 side of the reinforcing portion 85 and protrudes in a direction away from the holding plate 671. In addition, the detail of the angle which the reinforcement part 842 protrudes is mentioned later. A notch 94A is formed between the reinforcing

portions

812, 814, 81, and 841. The ends of the reinforcing

portions

841 and 842 on the side away from the holding plate 671 are joined together by a reinforcing portion 844 to be integrated. The width of the reinforcing

portions

841 and 842 in the tangential direction is, for example, the tangential direction from the edge on the leg plate 673 side of the holding plate 671 to the objective lens 16 so as not to disturb the optical paths of the first and second laser beams. It is shorter than the distance along The leg plate 672 side of the reinforcing

portions

841 and 842 has a shape that is curled toward the leg plate 673 side so as not to disturb the optical path of the first laser light incident on the first objective lens 16. The reinforcing portion 843 has a substantially rectangular shape and faces the inner surface of the leg plate 673. The reinforcing portion 843 is provided so as to protrude from the side of the reinforcing portion 841 on the leg plate 673 side toward the notch 94A. The reinforcing portions 831 to 834 have the same shape as the reinforcing portions 841 to 844. The reinforcing portions 831 to 834 are provided so as to be line-symmetric with the reinforcing portions 841 to 844 with respect to the center line P1.

In addition, the

reinforcement parts

81 and 87 are equivalent to a 3rd reinforcement part. The

reinforcement parts

811, 821, and 833 correspond to the first reinforcement part. The reinforcing

portions

812, 822, and 843 correspond to the second reinforcing portion.

=== Angle of the reinforcing

portions

82, 832 and 842 ===
Hereinafter, the angles of the reinforcing

portions

82, 832, and 842 in the present embodiment will be described with reference to FIGS. 3 to 8.
As described above, the reinforcing

portions

842, 832, and 82 are provided on the surface surrounded by the holding plate 671 and the

leg plates

672 and 673, so that they are provided on the optical paths of the first and second laser beams. . Therefore, for example, a part of the first and second laser diodes (open arrows in FIG. 8) that enter the lens holder 67 from the + Y side to the −Y side are the first of the reinforcing

portions

843, 832, and 82. In addition, there may be total reflection on the surface (+ Y) on the side where the second laser diode is incident. The total reflected light may hinder reading of good information from the optical disk 5. Therefore, it is necessary to suppress the total reflection of the first and second laser diodes at the reinforcing

portions

843, 832, and 82.
The reinforcing

portions

842 and 82 are provided to have angles D1 and D2 with respect to directions M3 and M4 perpendicular to the optical paths of the first and second laser beams. By adjusting the angles D1 and D2 so that the reading of good information from the optical disk 5 is not hindered by the reflection of the first and second laser beams at the reinforcing

portions

842, 832, and 82, the reinforcing

portions

842 and 832 are provided. , 82 can eliminate the influence of the reflection of the first and second laser beams.

=== Attaching the reinforcing plate, adhesive ===
Hereinafter, with reference to FIG. 4 thru | or FIG. 9, attachment of the reinforcement board to the lens holder in this embodiment and an adhesive agent are demonstrated.
The reinforcing plate 8 is bonded to the surface of the holding plate 671 and the

leg plates

672 and 673 that are surrounded by the holding plate 671 and the

leg plates

672 and 673 using the first adhesive 93 and the

second adhesives

91 and 92. The The first adhesive 93 is, for example, an epoxy resin adhesive having a high hardness, which is used for increasing the rigidity of the lens holder 67 and increasing the resonance frequency. The

second adhesives

91 and 92 are, for example, acrylic adhesives having a hardness lower than that of the first adhesive 93 and used to absorb the vibration of the lens holder 67 and reduce the resonance gain.
The reinforcing plate 8 is bonded to the inner surface (−Z) of the holding plate 671 by the first adhesive 93, and to the inner surface (−X) of the leg plate 672 and the inner surface (+ X) of the leg plate 673. They are bonded by the

second adhesives

91 and 92, respectively. Specifically, the reinforcing

portions

81, 87, 85, 813, and 814 are bonded to the inner surface of the holding plate 671 by the first adhesive 93. The reinforcing

portions

811, 821, and 833 are bonded to the inner surface of the leg plate 672 by the second adhesive 92. The reinforcing

portions

812, 822, and 843 are bonded to the inner surface of the leg plate 673 by the second adhesive 91.

=== Resonance frequency and gain ===
Hereinafter, the resonance frequency and gain of the lens holder in the present embodiment will be described with reference to FIGS. FIG. 10 is a characteristic diagram showing the relationship between the resonance frequency and the gain in the present embodiment. The horizontal axis indicates the frequency of the focus signal input to the first focus coils 71 and 74 and the second focus coils 72 and 75. The vertical axis represents the vibration gain of the lens holder. The relationship between the frequency and gain of the lens holder 67, the other lens holder Z1, and the other lens holder Z2 is indicated by a solid line, a two-dot chain line, and a one-dot chain line. The other lens holder Z1 is a lens holder in which the

second adhesives

91 and 92 in the lens holder 67 are changed to the first adhesive. That is, the other lens holder Z1 is a lens holder in which the reinforcing plate 8 is bonded using only the first adhesive. The other lens holder Z2 is a lens holder in which the first adhesive 93 is changed to the second adhesive in the lens holder 67. That is, the other lens holder Z2 is a lens holder in which the reinforcing plate 8 is bonded using only the second adhesive. FIG. 10 is a characteristic diagram obtained by experiments.

The resonance frequency F1 of the other lens holder Z1 (two-dot chain line in FIG. 10) is, for example, an upper limit frequency F4 (for example, 20 kHz) of a frequency band normally used as a focus signal frequency (hereinafter referred to as “normal frequency band”). ). The resonance gain Q1 of the other lens holder Z1 is, for example, a level at which good information reading may be hindered when the optical disk 5 is read. Therefore, when reading the optical disc 5 in the double speed mode, if the frequency of the focus signal is set higher than the normal frequency band, the reading of good information on the optical disc 5 may be hindered by the resonance of the other lens holder Z1. .

The resonance frequency F2 of the other lens holder Z2 (the chain line in FIG. 10) is, for example, lower than the frequency F4. The resonance gain Q2 of the other lens holder Z2 is, for example, smaller than the gain Q1. Therefore, resonance of the other lens holder Z2 occurs in the normal frequency band, and there is a possibility that good information reading from the optical disc 5 may be hindered.

The resonance frequency F3 of the lens holder 67 (solid line in FIG. 10) is, for example, higher than the frequency F4 and lower than the resonance frequency F1 of the other lens holder Z1. For example, the gain Q3 of the lens holder 67 is smaller than the gain Q2. Therefore, in the lens holder 67, the resonance frequency F3 is made higher than the upper limit frequency F4 of the normal frequency band, and the resonance gain Q3 is set to another lens holder Z1 in which the reinforcing plate 8 is bonded only with the first adhesive. The gain Q1 can be made smaller.

As described above, the holding plate 671 holds the first objective lens 16 and the second objective lens 26. The

leg plates

672 and 673 have a flat plate shape. The

leg plates

672 and 673 extend (rise) in the same direction from the opposing long sides of the holding plate 671, respectively. A first focus coil 71, a second focus coil 72, and a tracking coil 73 are attached to the leg plate 672. A first focus coil 74, a second focus coil 75, and a tracking coil 76 are attached to the leg plate 673. The reinforcing plate 8 is attached to the surfaces of the holding plate 671 and the

leg plates

672 and 673 that are surrounded by the holding plate 671 and the

leg plates

672 and 673. The reinforcing plate 8 is opposed to the reinforcing

portions

811, 821, 833 (first reinforcing portion) facing the leg plate 672, the reinforcing

portions

812, 822, 843 (second reinforcing portion) facing the leg plate 673, and the holding plate 671. It is the integral board which has the reinforcement parts 81 and 87 (3rd reinforcement part) to do. The reinforcing

portions

81 and 87 are bonded to the inner surface of the holding plate 671 by the first adhesive 93. The reinforcing

portions

811, 821, and 833 are bonded to the inner surface of the leg plate 672 by the second adhesive 92 having a hardness lower than that of the first adhesive 93. The reinforcing

portions

812, 822, and 843 are bonded to the inner surface of the leg plate 673 by the second adhesive 91 having a hardness lower than that of the first adhesive 93.
Therefore, the reinforcing plate 8 is securely bonded to the lens holder 67 by the first hard adhesive 93 to increase the rigidity of the lens holder 67 and the second bond having a hardness lower than that of the first adhesive 93. The vibrations of the lens holder 67 can be absorbed by the

agents

91 and 92. Accordingly, the resonance frequency of the lens holder 67 is set higher than the upper limit frequency of the normal frequency band, and the resonance gain is higher than the gain of the other lens holder Z1 in which the reinforcing plate 8 is bonded only with the first adhesive. Can be small.

The reinforcing plate 8 is an integral plate having first to third reinforcing portions and a reinforcing portion 85 (fourth reinforcing portion). The reinforcing portion 85 faces the inner surface of the holding plate 671 on the side opposite to the third reinforcing portion of the first objective lens 16. The reinforcing portion 85 is bonded to the inner surface of the holding plate 671 by the first adhesive 93. That is, the reinforcing portion 85 is provided at a position away from the third reinforcing portion in the holding plate 671. Therefore, for example, the resonance frequency can be reliably increased by preventing deformation of the holding plate 671 using the third reinforcing portion as a fulcrum and increasing the rigidity of the lens holder 67. In addition, when the reinforcing portion 85 has a shape provided between the end of the holding plate 671 and the first objective lens 16, it is not necessary to secure a new space for attaching the reinforcing plate 85, so a compact lens holder 67 can be provided.

Further, the reinforcing plate 8 has a curved arm C. The curved arm C has a shape that follows the inclination of the first rising mirror 15 disposed at a position facing the first objective lens 16 in a region surrounded by the holding plate 671 and the

leg plates

672 and 673. The third reinforcing portion and the fourth reinforcing portion are joined together by the bending arm C to be integrated. Therefore, by combining the third reinforcing portion and the fourth reinforcing portion so as to be integrated, the rigidity of the lens holder 67 can be further increased, and the resonance frequency can be further reliably increased. Further, since the reinforcing plate 8 and the first rising mirror 15 do not interfere with each other, the first objective lens 16 and the second objective lens 26 can be reliably displaced in the focus direction and the tracking direction. Further, when the lens holder 67 is displaced in the tracking direction and the focus direction, the reinforcing plate 8 is not rubbed and worn with the first rising mirror 15, so that a highly durable lens holder 67 can be provided.

The holding plate 671 holds the first objective lens 16 and the second objective lens 26 so as to be adjacent to each other. Each of the

leg plates

672 and 673 extends (rises) in the same direction from the long sides facing each other along the direction in which the first objective lens 16 and the second objective lens 26 of the holding plate 671 are adjacent to each other. The reinforcing plate 8 has first to fourth reinforcing portions. The fourth reinforcing portion faces the inner surface of the holding plate 671 on the side opposite to the third reinforcing portion of the first objective lens 16. Accordingly, the reinforcing plate 8 need only be provided on the first objective lens 16 side, not the entire region surrounded by the holding plate 671 and the

leg plates

672 and 673 of the lens holder 67. 67 can be reduced in weight.

Further, the reinforcing portion 82 is bent on the second objective lens 26 side from the approximate center of the holding plate 671 in the tracking direction. When the

leg plates

672 and 673 vibrate, for example, the

leg plates

672 and 673 vibrate using the reinforcing portion 82 as a fulcrum. Therefore, the amplitude of vibration on the first objective lens 16 side of the reinforcing portion 82 in the

leg plates

672 and 673 is larger than the amplitude of vibration on the second objective lens 26 side of the reinforcing portion 82 in the

leg plates

672 and 673. Therefore, when the vibration of the lens holder 67 is attenuated by adjusting the output of the focus signal of the coil to suppress the vibration, the focus signals of the first focus coils 71 and 74 and the second focus coils 72 and 75 are individually adjusted. Instead, it is only necessary to adjust the output of the focus signals of the second focus coils 72 and 75 on the side where the vibration amplitude is large so that the vibration is suppressed. Therefore, since the vibration of the lens holder 67 can be attenuated with certainty, the user-friendly lens holder 67 can be provided.

Also, the holding plate 671 and the

leg plates

672 and 673 are integrally formed using resin. Therefore, the lens holder 67 can be reduced in weight. Moreover, since it is integrally molded, it is not necessary to perform assembly work, and the manufacturing cost of the lens holder 67 can be reduced. The reinforcing plate 8 is formed by bending a metal plate. Therefore, since the reinforcement plate 8 can be easily formed, the manufacturing cost of the lens holder 67 can be further reduced.

The objective lens driving device includes an actuator 6, a lens holder 67, a first objective lens 16, a second objective lens 26, and a coil. Therefore, since the resonance frequency of the lens holder 67 can be increased and the resonance gain can be reduced, the accuracy of displacing the first objective lens 16 and the second objective lens 26 in the tracking direction and the focus direction can be improved.

Further, the optical pickup device 100 includes optical elements including the

first laser diodes

11A and 11B, the second laser diode 21, the first rising mirror 15 and the second rising mirror 25, and an objective lens driving device. Therefore, since the accuracy of displacement in the tracking direction and the focus direction can be improved, it is possible to provide the optical pickup device 100 that can read information on the optical disc 5 satisfactorily.

In addition, this embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. The present invention can be changed and improved without departing from the gist thereof, and equivalents thereof are also included in the present invention.

In the present embodiment, the configuration in which the holding plate 671 holds the two objective lenses of the first objective lens 16 and the second objective lens 26 has been described, but is not limited thereto. For example, the holding plate 671 may be configured to hold only one of the first objective lens 16 and the second objective lens 26. In that case, since the length of the side where the

leg plates

672 and 673 are provided in the holding plate 671 can be shortened, the rigidity of the objective lens holder can be increased. Therefore, the resonance frequency can be reliably increased. In addition, since the area of the holding plate 671 can be reduced, a compact lens holder can be provided.

5 Optical disc 5A First optical disc 5B Second optical disc 5C Third optical disc 6 Actuator 8 Reinforcing

plates

11A and 11B First laser diode 12 First diffraction grating 13 First half-wave plate 15 First rising mirror 16 First objective Lens 17 First holder 21 Second laser diode 22 Second diffraction grating 23 Second half-wave plate 24 Coupling lens 25 Second rising mirror 26 Second objective lens 27 Second holder 31 Front monitor diode 32 Beam splitter 33 Collimating lens 34 1/4 wavelength plate 35 Reflecting mirror 36 Half mirror 37 Detection lens 38 Photo detector 50 Housing 67

Lens holder

71, 74

First focus coil

72, 75

Second focus coil

73, 76

Tracking direction

91, 92 First 2 Adhesive 93

First Adhesive

9 A, 92A, 93A, 94A notch 100 optical pickup device 110 first laser light source 210 and the second laser light source 671 holding

plate

672 and 673 leg plate A, B, D reinforcement portion C curved arms

Claims

A rectangular holding plate for holding the objective lens;
Flat plate-like first and second leg plates to which coils for rising in the same direction from two opposite sides of the holding plate and displacing the objective lens in at least one of a focus direction and a tracking direction are respectively attached;
A reinforcing plate attached to a surface of the holding plate and the first and second leg plates surrounded by the holding plate and the first and second leg plates;
With
The reinforcing plate has an integrated plate composed of first and second reinforcing portions facing the first and second leg plates, respectively, and a third reinforcing portion facing the holding plate,
The third reinforcing portion is bonded to the holding plate with a first adhesive,
The objective lens holder, wherein the first and second reinforcing portions are respectively bonded to the first and second leg plates with a second adhesive having a hardness lower than that of the first adhesive. .
The reinforcing plate has an integrated plate composed of the first to third reinforcing portions and a fourth reinforcing portion facing the holding plate on the side opposite to the third reinforcing portion of the objective lens,
The objective lens holder according to claim 1, wherein the fourth reinforcing portion is bonded to the holding plate with the first adhesive.
The reinforcing plate has a curved arm that follows an inclination of a rising mirror disposed at a position facing the objective lens in a region surrounded by the holding plate and the first and second leg plates,
The objective lens holder according to claim 2, wherein the third and fourth reinforcing portions are coupled by the curved arm.
The holding plate holds the first and second objective lenses adjacent to each other as the objective lens,
The first and second leg plates rise in the same direction from two opposite sides of the holding plate along the direction in which the first and second objective lenses are adjacent to each other,
The reinforcing plate includes an integrated plate including the first to third reinforcing portions and a fourth reinforcing portion facing the holding plate on the side opposite to the third reinforcing portion of the first objective lens. The objective-lens holder of Claim 2 characterized by these.
The reinforcing plate has a curved arm that follows an inclination of an upright mirror disposed at a position facing the first objective lens in a region surrounded by the holding plate and the first and second leg plates,
The objective lens holder according to claim 4, wherein the third and fourth reinforcing portions are coupled by the curved arm.
The holding plate and the first and second leg plates are integrally formed using a resin,
The objective lens holder according to claim 1, wherein the reinforcing plate is formed by bending a metal plate.
The objective lens holder according to any one of claims 1 to 6,
The objective lens;
The coil;
A magnet facing the coil;
An actuator for displacing the objective lens holder;
An objective lens driving device comprising:
A laser diode;
An optical element including the rising mirror for guiding laser light emitted by the laser diode to the objective lens;
The objective lens driving device according to claim 7,
An optical pickup device comprising: