OPTICAL SCANNING DEVICE, DISTANCE MEASURING DEVICE AND METHOD FOR MANUFACTURING AN OPTICAL SCANNING DEVICE

Abstract

Optical scanning device (100) comprising: - a reflector (10) for reflecting light; - a rotator to which the reflector (10) is applied; - a first torsion bar (21) and a second torsion bar (22) between which the rotator is arranged; - a first support member (31), wherein the first torsion bar (21) is arranged between the first support member (31) and the rotator; - a second support member (32), wherein the second torsion bar (22) is arranged between the second support member (32) and the rotator; - a first elastic layer (41) applied to the first torsion bar (21); - a second elastic layer (42) applied to the second torsion bar (22); - a magnet (M) arranged separately from the rotator; - a first conductor track (71) arranged on the first support part (31); and - a second conductor track (72) arranged on the second support part (32), and wherein - the rotator is rotatable with respect to the first support member (31) and the second support member (32), the first torsion bar (21) and the second torsion bar (22) forming an axis of rotation, - the rotator, the first torsion bar (21) and the second torsion bar (22) contain a common active layer (LA), and wherein - in a cross-section orthogonal to a direction in which the rotator is arranged between the first torsion bar (21) and the second torsion bar (22), a vertical dimension of the active layer (LA) is smaller than a horizontal dimension of the active layer (LA), and - wherein a material of the first elastic layer (41) and the second elastic layer (42) is an elastic material having a higher fatigue life than metal, and wherein - the rotator has a coil line (5) which is applied to the active layer (LA), and wherein - the rotator is to be set in rotation by a Lorentz force generated by a current flowing through the coil line (5) and a magnetic force generated by the magnet (M), and wherein - the first elastic layer (41) has a first diffusion conduction region (41D) doped with an impurity, and wherein - the second elastic layer (42) has a second diffusion conduction region (42D) doped with an impurity, and - the first conductor track (71) is electrically connected to the second conductor track (72) via the first diffusion line region (41D), the coil line (5) and the second diffusion line region (42D).

Description

TECHNICAL FIELD

[0001] The present invention relates to an optical scanning device, a distance measuring device and a method for manufacturing an optical scanning device. STATE OF THE ART

[0002] An optical scanning device using MEMS (Micro Electro Mechanical Systems) technology is known. Such an optical scanning device is compact and operates with high precision. The optical scanning device is used to scan light emitted onto a reflector by rotating a rotator, to which the reflector is mounted, around a first torsion bar and a second torsion bar.

[0003] The rotator, the first torsion bar, and the second torsion bar contain a common active layer. The active layer is made of silicon (Si), for example. The active layer is processed using a semiconductor process such as deep reactive ion etching (DRIE).

[0004] For example, in Japanese Patent Application Laid-Open No. JP 2005-292321 A (Patent Document 1), a planar actuator (optical scanning device) includes a mirror (reflector), a movable plate (rotator), a torsion bar (first torsion bar and second torsion bar), and a metal film. The movable plate and the torsion bar share a silicon active layer (active layer). The metal film is deposited on the torsion bar.

[0005] Japanese Patent Application Laid-Open No. JP 2010-139546 A (Patent Document 2) includes a mirror having a reflecting surface capable of vibrating relative to a substrate.

[0006] German Patent Application Laid-Open No. DE 11 2019 007 156 T5 (Patent Document 3) discloses an optical scanning device comprising a first structure and a second structure. The first structure includes a support, a driver, a first columnar body, a driver region, and a pair of beams. The support includes a support body and a flat region. The pair of beams connects the driver and the flat region. The driver region includes a coil, a pair of electrode pads, and a magnet. The second structure is provided with a reflector. PRIOR ART DOCUMENTS Patent document Patent Document 1: Japanese Patent Application Laid-Open No. JP 2005-292321 A Patent Document 2: Japanese Patent Application Laid-Open No. JP 2010 - 139546 A Patent document 3: German patent application publication DE 11 2019 007 156 T5 BRIEF DESCRIPTION OF THE INVENTIONTechnical problem

[0007] In the planar actuator (optical scanning device) disclosed in Patent Document 1, the metal film is applied to the torsion bar (first torsion bar and second torsion bar). This can increase a dimension of the planar actuator of the torsion bar in a thickness direction and limit an increase in a width dimension of the torsion bar.

[0008] This in turn can reduce a hard spring effect of the planar actuator at the position of the torsion bar and limit a reduction of a maximum deflection angle of the rotator.

[0009] The hard spring effect increases the peak frequency. However, the rotation of the rotator repeatedly stresses the metal layer, causing it to degrade. This can reduce the long-term reliability of the planar actuator.

[0010] The present invention has been made in view of the problems described above, and the object of the present invention is therefore to provide an optical pickup device, a distance measuring device and a method for manufacturing an optical pickup device, the optical pickup device being capable of reducing a hard spring effect at positions of a first torsion bar and a second torsion bar, limiting a decrease in a maximum deflection angle of a rotator and having high long-term reliability. Solution to the problem

[0011] The present invention solves the problem with an optical scanning device comprising: a reflector for reflecting light; a rotator to which the reflector is applied; a first torsion bar and a second torsion bar, between which the rotator is arranged; a first support part, wherein the first torsion bar is arranged between the first support part and the rotator; a second support part, wherein the second torsion bar is arranged between the second support part and the rotator; a first elastic layer applied to the first torsion bar;and a second elastic layer applied to the second torsion bar, wherein the rotator is rotatable with respect to the first support member and the second support member, wherein the first torsion bar and the second torsion bar form a rotation axis, wherein the rotator, the first torsion bar, and the second torsion bar include a common active layer, and wherein, in a cross-section orthogonal to a direction in which the rotator is arranged between the first torsion bar and the second torsion bar, a vertical dimension of the active layer is smaller than a horizontal dimension of the active layer, and a material of the first elastic layer and the second elastic layer is an elastic material having a higher fatigue life than metal.; Advantageous effect of the invention

[0012] In the optical pickup device according to the present invention, the first elastic layer is applied to the first torsion bar. The second elastic layer is applied to the second torsion bar. This can reduce the hard spring effect of the optical pickup device at the positions of the first torsion bar and the second torsion bar and limit a reduction in the maximum deflection angle of the rotator.

[0013] Furthermore, the first elastic layer and the second elastic layer are made of an elastic material that has a longer fatigue life than metal. This makes it possible to provide the optical pickup device with high long-term reliability. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic perspective view of a configuration of an optical pickup device according to a first embodiment. Fig. 2 is a schematic perspective view of the configuration of the optical pickup device according to the first embodiment. Fig. 3 is a cross-sectional view taken along a line III-III according to Fig. 1. Fig. 4 is a schematic perspective view of a configuration of an optical pickup device according to a first modification of the first embodiment. Fig. 5 is a schematic cross-sectional view of a configuration of an optical pickup device according to a second modification of the first embodiment. Fig. 6 is a schematic cross-sectional view of the optical pickup device according to the first embodiment in a preparation step. Fig. 7 is a schematic cross-sectional view of a substrate to which an elastic material is applied according to the first embodiment. Fig. 8 is a schematic cross-sectional view of the optical pickup device according to the first embodiment in a forming step. Fig. 9 is a schematic cross-sectional view of the optical pickup device according to the first embodiment, in which a coil line and the like are arranged. Fig. 10 is a schematic cross-sectional view of the optical pickup device according to the first embodiment in a lamination step. Fig. 11 is a graph showing a relationship between a thickness of an active layer and 0 / 00 and a relationship between the thickness of the active layer and an aspect ratio. Fig. 12 is a schematic perspective view of a configuration of an optical pickup device according to a second embodiment. Fig. 13 is a schematic cross-sectional view of the configuration of the optical pickup device according to the second embodiment. Fig. 14 is a schematic perspective view of a configuration of an optical pickup device according to a third embodiment. Fig. 15 is a schematic cross-sectional view of the configuration of the optical pickup device according to the third embodiment. Fig. 16 is a schematic cross-sectional view of the optical pickup device according to the third embodiment in a doping step. Fig. 17 is a schematic cross-sectional view of a substrate to which an elastic material is applied according to the third embodiment. Fig. 18 is a schematic cross-sectional view of the optical pickup device according to the third embodiment in a forming step. Fig. 19 is a schematic cross-sectional view of the optical pickup device according to the third embodiment in a lamination step. Fig. 20 is a schematic perspective view of a configuration of an optical pickup device according to a fourth embodiment. Fig. 21 is a schematic plan view showing the configuration of the optical pickup device according to the fourth embodiment. Fig. 22 is a schematic perspective view of a configuration of an optical pickup device according to a fifth embodiment. Fig. 23 is a schematic plan view showing the configuration of the optical pickup device according to the fifth embodiment. Fig. 24 is a block diagram schematically illustrating a configuration of an optical pickup device according to a sixth embodiment. Fig. 25 is a block diagram schematically illustrating another configuration of an optical pickup device according to the sixth embodiment. DESCRIPTION OF THE EMBODIMENTS

[0014] Embodiments are described below with reference to the drawings. To avoid redundancies, identical or corresponding parts are designated by identical reference numerals in the following description. Furthermore, it is emphasized that the present invention is limited to an optical scanning device according to the second embodiment, according to Fig. 12 and Fig. 13, is directed. First embodiment

[0015] With reference to Fig. 1 to 3, a configuration of an optical pickup device 100 according to a first embodiment will be described, which explains specific aspects of the present invention for better understanding. For the sake of simplicity, a lower and an upper insulating film are shown in Fig. 2 not shown.

[0016] As in Fig. 1, an optical pickup device 100 includes a reflector 10, a rotator 1, a first torsion bar 21 and a second torsion bar 22, a first support member 31, a second support member 32, a first elastic layer 41, and a second elastic layer 42.

[0017] In the present embodiment, the optical pickup device 100 further includes a magnet M. The optical pickup device 100 may include a first metal line 61 and a second metal line 62.

[0018] The optical scanning device 100 is used to scan light. The optical scanning device 100 is, for example, an optical MEMS (microelectromechanical system) mirror scanning device. Such an optical MEMS mirror scanning device is used, for example, in a distance measuring device, a projector, and the like. The optical scanning device 100 is formed, for example, by processing a silicon-on-insulator (SOI) substrate.

[0019] As in Fig. 1, the rotator 1, the first torsion bar 21, and the second torsion bar 22 include a common active layer LA. In a cross-section orthogonal to a direction (X-axis direction) in which the rotator 1 is arranged between the first torsion bar 21 and the second torsion bar 22, a vertical dimension (dimension in a Z-axis direction) of the active layer LA is smaller than a horizontal dimension (dimension in a Y-axis direction) of the active layer LA. A ratio between the vertical dimension (dimension in the Z-axis direction) of the active layer LA and the horizontal dimension (dimension in the Y-axis direction) of the active layer LA is less than 1.

[0020] The first support member 31 and the second support member 32 contain the active layer LA, which is common to the rotator 1, the first torsion bar 21, and the second torsion bar 22. The rotator 1, the first support member 31, and the second support member 32 contain a support layer LS. The rotator 1, the first torsion bar 21, the second torsion bar 22, the first support member 31, and the second support member 32 may contain a common surface oxide film LOS, a common intermediate oxide film LOI, a common lower insulating film LI1, and a common upper insulating film LI2.

[0021] The reflector 10 serves to reflect light. The reflector 10 is a metal film. The reflector 10 is preferably made of metal with a high reflectance at a wavelength of the light to be scanned. The light to be scanned is, for example, infrared rays.

[0022] If the light to be scanned is infrared rays, the reflector 10 is preferably a gold (Au) film. If the reflector 10 is a gold (Au) film, the reflector 10 preferably includes an adhesive layer (not shown). The adhesive layer (not shown) adheres to the active layer LA. This can increase adhesion between the reflector 10 and the active layer LA.

[0023] The reflector 10 including the adhesive layer (not illustrated) is formed, for example, by laminating a chromium (Cr) film, a nickel (Ni) film, and a gold (Au) film. The reflector 10 including the adhesive layer (not illustrated) is formed, for example, by laminating a titanium (Ti) film, a platinum (Pt) film, and a gold (Au) film.

[0024] When packaging the optical pickup device 100, the optical pickup device 100 may, for example, be vacuum-encapsulated to make the reflector 10 oxidation-resistant. For example, the optical pickup device 100 may be filled with an inert gas such as nitrogen (N2) during packaging to make the reflector 10 oxidation-resistant. When making the reflector 10 oxidation-resistant, the reflector 10 may be an aluminum (Al) film.

[0025] As in Fig. As shown in Figure 1, the reflector 10 is mounted on the rotator 1. The rotator 1 is arranged between the first torsion bar 21 and the second torsion bar 22. The rotator 1 is rotatable with respect to the first support member 31 and the second support member 32, with the first torsion bar 21 and the second torsion bar 22 forming a rotation axis.

[0026] As in Fig. As shown in Figure 1, in the present embodiment, the direction in which the reflector 10 is mounted on the rotator 1 is the Z-axis direction. A direction from the rotator 1 to the reflector 10 is a positive Z-axis direction. A direction from the reflector 10 to the rotator 1 is a negative Z-axis direction.

[0027] A direction in which the rotator 1 is arranged between the first torsion bar 21 and the second torsion bar 22 is the X-axis direction. A direction from the first torsion beam 21 to the second torsion beam 22 is a positive direction of the X-axis. A direction from the second torsion beam 22 to the first torsion beam 21 is a negative direction of the X-axis. A direction orthogonal to both the X-axis and the Z-axis is the Y-axis. In the present embodiment, the X-axis, Y-axis, and Z-axis form a right-hand system.

[0028] As in Fig. 1, in a cross section orthogonal to a direction (X-axis direction) in which the rotator 1 is arranged between the first torsion bar 21 and the second torsion bar 22, a vertical dimension (dimension in the Z-axis direction) of the first torsion bar 21 of the optical scanning device 100 is less than or equal to a horizontal dimension (dimension in the Y-axis direction) of the first torsion bar 21 of the optical scanning device 100. In a cross section orthogonal to a direction (X-axis direction) in which the rotator 1 is arranged between the first torsion bar 21 and the second torsion bar 22, a vertical dimension (dimension in the Z-axis direction) of the second torsion bar 22 of the optical scanning device 100 is less than or equal to a horizontal dimension (dimension in the Y-axis direction) of the second torsion bar 22 of the optical scanning device 100.

[0029] As in Fig. 2, the first elastic layer 41 is applied to the first torsion bar 21. The first elastic layer 41 is applied to the first torsion bar 21 in the positive direction of the Z-axis. The first elastic layer 41 covers at least a part of the first torsion bar 21. The first elastic layer 41 extends in the X-axis direction. The first elastic layer 41 may be arranged to extend from the first support member 31 to the rotator 1. In the present embodiment, the surface oxide film LOS is arranged between the first elastic layer 41 and the first torsion bar 21.

[0030] As in Fig. 2, the second elastic layer 42 is applied to the second torsion bar 22. The second elastic layer 42 is applied to the second torsion bar 22 in the positive direction of the Z-axis. The second elastic layer 42 covers at least a part of the second torsion bar 22. The second elastic layer 42 extends in the X-axis direction. The second elastic layer 42 may be arranged to extend from the second support member 32 to the rotator 1. In the present embodiment, the surface oxide film LOS is arranged between the second elastic layer 42 and the second torsion bar 22.

[0031] The first elastic layer 41 and the second elastic layer 42 are elastic. The first elastic layer 41 and the second elastic layer 42 have a longer fatigue life than metal.

[0032] In the present embodiment, the fatigue life is the number of stresses until a material repeatedly subjected to the stress breaks. The first elastic layer 41 and the second elastic layer 42 may have a longer fatigue life than, for example, aluminum (Al) and an aluminum (Al)-based alloy. The aluminum (Al)-based alloy is, for example, an aluminum-silicon (Al-Si) alloy. The first elastic layer 41 and the second elastic layer 42 have a longer fatigue life than a metal conductive member. Furthermore, the first elastic layer 41 and the second elastic layer 42 have a higher elastic limit than metal.

[0033] Even if stress is generated by a strain applied to the first elastic layer 41 and the second elastic layer 42, the first elastic layer 41 and the second elastic layer 42 should eliminate the stress in response to the removal of the strain. That is, even if the first elastic layer 41 and the second elastic layer 42 are deformed, the first elastic layer 41 and the second elastic layer 42 should return to their original shape in response to the removal of the strain.

[0034] It should be noted that when the first elastic layer 41 and the second elastic layer 42 are subjected to a stress exceeding the elastic limit, they do not return to their original shape even if the stress is removed.

[0035] As in Fig. As shown in Figure 2, the respective dimensions of the first torsion bar 21, the second torsion bar 22, the first elastic layer 41, and the second elastic layer 42 in the Y-axis direction are smaller than the dimensions of the rotator 1 in the Y-axis direction. The first torsion bar 21 and the first elastic layer 41 serve as a torsion spring. The second torsion bar 22 and the second elastic layer 42 serve as a torsion spring.

[0036] The material of the first elastic layer 41 and the second elastic layer 42 is an elastic material with a longer fatigue life than metal. The material of the first elastic layer 41 and the second elastic layer 42 contains, for example, silicon (Si). The material of the first elastic layer 41 and the second elastic layer 42 contains, for example, polysilicon.

[0037] In the present embodiment, polysilicon is polycrystalline silicon. The material of the first elastic layer 41 and the second elastic layer 42 includes, for example, monocrystalline silicon. The first elastic layer 41 and the second elastic layer 42 can be made, for example, from a wafer (silicon wafer) made of silicon (Si). The material of the first elastic layer 41 and the second elastic layer 42 includes, for example, amorphous silicon.

[0038] As in Fig. 2, the first torsion bar 21 is arranged between the first support member 31 and the rotator 1. The first support member 31 supports the first torsion bar 21. The second torsion bar 22 is arranged between the second support member 32 and the rotator 1. The second support member 32 supports the second torsion bar 22. The first support member 31 and the second support member 32 are not intended to rotate when the rotator 1, the first torsion bar 21, and the second torsion bar 22 rotate. The first support member 31 and the second support member 32 are fixed to a table (not shown), for example. The table (not shown) is arranged, for example, in the negative direction of the Z-axis relative to the first support member 31 and the second support member 32.

[0039] As in Fig. 2, a first metal line 61 extends from the first support part 31 via the first torsion bar 21 to the rotator 1. A second metal line 62 extends from the second support part 32 via the second torsion bar 22 to the rotator 1. The first metal line 61 and the second metal line 62 are arranged along the upper insulating film LI2 (see FIG. Fig. 3). The first metal line 61 and the second metal line 62 are made of metal with high electrical conductivity. Examples of the material of the first metal line 61 and the second metal line 62 include aluminum (Al), aluminum nitride (AlN), and the like.

[0040] As in Fig. 2, the rotator 1 includes a coil line 5. The coil line 5 is deposited on the active layer LA. The coil line 5 includes a line extending in the X-axis direction. The coil line 5 has, for example, a spiral shape. The first metal line 61 and the second metal line 62 are electrically connected to the coil line 5. The coil line 5 is made of a metal with high electrical conductivity. Examples of the material of the coil line 5 include aluminum (Al), aluminum nitride (AlN), and the like. A current flowing through the coil line 5 flows at least partially in the X-axis direction.

[0041] As in Fig. 2, a magnet M is arranged separately from the rotator 1. The magnet M is, for example, a permanent magnet. The magnet M includes a first magnet M1 and a second magnet M2. The rotator 1 is arranged between the first magnet M1 and the second magnet M2, with a gap existing between the rotator 1, the first magnet M1, and the second magnet M2. The rotator 1 is arranged between the first magnet M1 and the second magnet M2 in the Y-axis direction. A magnetic field generated by the magnet M has a magnetic field in the Y-axis direction. The second magnet M2 is arranged in the positive direction of the Y-axis relative to the first magnet M1.

[0042] The rotator 1 is rotated by Lorentz force, electrostatic force, or the like. In the present embodiment, the rotator 1 is rotated by a Lorentz force generated by the current flowing through the coil line 5 and a magnetic force generated by the magnet M. When the current flows through the coil line 5, it flows in the X-axis direction. The Lorentz force in the Z-axis direction is generated in the coil line 5 by the current flowing in the X-axis direction through the coil line 5 and the magnetic field generated by the magnet M in the Y-axis direction. This exerts a force in the Z-axis direction on the coil line 5 of the rotator 1. As a result, a torque is generated in the rotator 1 about the first torsion bar 21 and the second torsion bar 22. This in turn causes the rotator 1 to rotate about the first torsion bar 21 and the second torsion bar 22 relative to the supporting parts.

[0043] With reference to Fig. 3, a detailed description will be given below of configurations of the active layer LA, the support layer LS and the like according to the first embodiment.

[0044] As in Fig. 3, the support layer LS, the intermediate oxide film LOI, the active layer LA, the surface oxide film LOS, the lower insulating film LI1 and the upper insulating film LI2 are laminated in this order.

[0045] The support layer LS extends in one in-plane direction (along a plane formed by the X-axis and the Y-axis). The support layer LS is larger in thickness direction (Z-axis direction) than the active layer LA.

[0046] The material of the support layer LS contains, for example, silicon (Si). The support layer LS includes a first support layer 1S, a second support layer 31S, and a third support layer 32S. The first support layer 1S, the second support layer 31S, and the third support layer 32S are arranged separately from one another.

[0047] The intermediate oxide film LOI is laminated directly onto the support layer LS in the Z-axis direction. The material of the intermediate oxide film LOI includes, for example, silicon (Si). The intermediate oxide film LOI includes a first intermediate oxide film 1OI, a second intermediate oxide film 31OI, and a third intermediate oxide film 32OI. The first intermediate oxide film 1OI, the second intermediate oxide film 31OI, and the third intermediate oxide film 32OI are arranged separately from each other.

[0048] The active layer LA is laminated directly onto the intermediate oxide film LOI in the Z-axis direction. The active layer LA can have a uniform dimension in the Z-axis direction. Oxide films are located on both sides of the active layer LA. The material of the active layer LA contains, for example, silicon (Si). The material of the active layer LA contains, for example, monocrystalline silicon. The active layer LA is made, for example, from a monocrystalline silicon wafer.

[0049] The active layer LA includes a first active layer 1A, a second active layer 31A, a third active layer 32A, a fourth active layer 21A, and a fifth active layer 22A. The first active layer 1A, the second active layer 31A, the third active layer 32A, the fourth active layer 21A, and the fifth active layer 22A are integrally formed.

[0050] The first active layer 1A is arranged in a plane direction between the fourth active layer 21A and the fifth active layer 22A. The fourth active layer 21A is arranged in a plane direction between the first active layer 1A and the second active layer 31A. The fifth active layer 22A is arranged in a plane direction between the first active layer 1A and the third active layer 32A.

[0051] The surface oxide film LOS is laminated directly onto the active layer LA in the Z-axis direction. The surface oxide film LOS can have a uniform dimension in the Z-axis direction. The first elastic layer 41 and the second elastic layer 42 are laminated directly onto the surface oxide film LOS. The material of the surface oxide film LOS contains, for example, silicon (Si).

[0052] The surface oxide film LOS includes a first surface oxide film 1OS, a second surface oxide film 31OS, a third surface oxide film 32OS, a fourth surface oxide film 21OS, and a fifth surface oxide film 22OS. The first surface oxide film 1OS, the second surface oxide film 31OS, the third surface oxide film 32OS, the fourth surface oxide film 21OS, and the fifth surface oxide film 22OS are integrally formed.

[0053] The first surface oxide film 1OS is disposed in an in-plane direction between the fourth surface oxide film 21OS and the fifth surface oxide film 22OS. The fourth surface oxide film 21OS is disposed in an in-plane direction between the first surface oxide film 1OS and the second surface oxide film 31OS. The fifth surface oxide film 22OS is disposed in an in-plane direction between the first surface oxide film 1OS and the third surface oxide film 32OS.

[0054] The lower insulating film LI1 is laminated directly onto the active layer LA, the first elastic layer 41, and the second elastic layer 42 in the Z-axis direction. The coil line 5 is arranged on the lower insulating film LI1. The lower insulating film LI1 is, for example, an oxide film, an organic film, or the like.

[0055] The lower insulating film LI1 includes a first lower insulating film 1I1, a second lower insulating film 31I1, a third lower insulating film 32I1, a fourth lower insulating film 21I1, and a fifth lower insulating film 22I1. The first lower insulating film 1I1, the second lower insulating film 31I1, the third lower insulating film 32I1, the fourth lower insulating film 21I1, and the fifth lower insulating film 22I1 are integrally formed.

[0056] The first lower insulating film 1I1 is arranged in an in-plane direction between the fourth lower insulating film 21I1 and the fifth lower insulating film 22I1. The fourth lower insulating film 21I1 is arranged in an in-plane direction between the first lower insulating film 1I1 and the second lower insulating film 31I1. The fifth lower insulating film 22I1 is arranged in an in-plane direction between the first lower insulating film 1I1 and the third lower insulating film 32I1.

[0057] The upper insulating film LI2 is directly laminated to the lower insulating film LI1 and the coil line 5. The reflector 10 is arranged on the upper insulating film LI2. The first metal line 61 and the second metal line 62 are arranged on the upper insulating film LI2. The distance between the upper insulating film LI2 and the surface oxide film LOS can be uniform in the Z-axis direction. The upper insulating film LI2 is, for example, an oxide film, an organic film, or the like.

[0058] The upper insulating film LI2 includes a first upper insulating film 1I2, a second upper insulating film 3I2, a third upper insulating film 32I2, a fourth upper insulating film 2I2, and a fifth upper insulating film 22I2. The first upper insulating film 1I2, the second upper insulating film 31I2, the third upper insulating film 32I2, the fourth upper insulating film 2I2, and the fifth upper insulating film 22I2 are integrally formed.

[0059] The first upper insulating film 1I2 is arranged in an in-plane direction between the fourth upper insulating film 21I2 and the fifth upper insulating film 22I2. The fourth upper insulating film 21I2 is arranged in an in-plane direction between the first upper insulating film 1I2 and the second upper insulating film 31I2. The fifth upper insulating film 22I2 is arranged in an in-plane direction between the first upper insulating film 1I2 and the third upper insulating film 32I2.

[0060] As in Fig. As shown in Figure 3, the rotator 1 includes a first support layer 1S, a first intermediate oxide film 1OI, a first active layer 1A, a first surface oxide film 1OS, a first lower insulating film 1I1, and a first upper insulating film 1I2. The first support layer 1S, the first intermediate oxide film 1OI, the first active layer 1A, the first surface oxide film 1OS, the first lower insulating film 1I1, and the first upper insulating film 1I2 are laminated in this order.

[0061] The first torsion bar 21 includes the fourth active layer 21A, the fourth surface oxide film 21O5, the fourth lower insulating film 21I1, and the fourth upper insulating film 21I2. The fourth active layer 21A, the fourth surface oxide film 21O5, the first elastic layer 41, the fourth lower insulating film 21I1, and the fourth upper insulating film 21I2 are laminated in this order.

[0062] The second torsion bar 22 includes the fifth active layer 22A, the fifth surface oxide film 22O5, the fifth lower insulating film 22I1, and the fifth upper insulating film 22I2. The fifth active layer 22A, the fifth surface oxide film 22O5, the second elastic layer 42, the fifth lower insulating film 22I1, and the fifth upper insulating film 22I2 are laminated in this order.

[0063] The first support member 31 includes a second support layer 31S, a second intermediate oxide film 31OI, a second active layer 31A, a second surface oxide film 31OS, a second lower insulating film 31I1, and a second upper insulating film 31I2.

[0064] The second support layer 31S, the second intermediate oxide film 31OI, the second active layer 31A, the second surface oxide film 31OS, the second lower insulating film 31I1 and the second upper insulating film 31I2 are laminated in this order.

[0065] The second support member 32 includes a third support layer 32S, a third intermediate oxide film 32OI, a third active layer 32A, a third surface oxide film 32OS, a third lower insulating film 32I1, and a third upper insulating film 32I2. The third support layer 32S, the third intermediate oxide film 32OI, the third active layer 32A, the third surface oxide film 32OS, the third lower insulating film 32I1, and the third upper insulating film 32I2 are laminated in this order.

[0066] With reference to Fig. 4, a configuration of the optical scanning device 100 according to a first development of the first embodiment will be described below. As in Fig. 4, the rotator 1 includes a recess 11. The recess 11 is directed with respect to the active layer LA to a side opposite the reflector 10 (see Fig. 1). The recess 11 is open in the negative direction of the Z-axis.

[0067] In the present embodiment, the recess 11 is provided in the support layer LS. In the present embodiment, the support layer LS is partially hollow. The rotator 1 is lighter than the rotator 1 with a solid support layer LS. The rotator 1 has a rib structure extending in the Z-axis direction. The support layer LS can be smaller than the active layer LA in a dimension in the X-axis direction. The support layer LS can be smaller than the active layer LA in a dimension in the Y-axis direction.

[0068] With reference to Fig. 5, a configuration of the optical pickup device 100 according to a second modification of the first embodiment will be described below. In the second modification of the first embodiment, the lower insulating film LI1 is curved upward 42 in the positive direction of the Z-axis by the first elastic layer 41 and the second elastic layer 42. The upper insulating film LI2 is curved upward in the positive direction of the Z-axis along the upward curvature of the lower insulating film LI1. A first metal line 61 and a second metal line 62 are arranged along the upward curvature of the lower insulating film LI1 and the upward curvature of the upper insulating film LI2. This causes the first conductive line 71 and the second conductive line 72 to deform in the positive direction of the Z-axis.

[0069] With reference to Fig. 3 and 6 to 10, a method for manufacturing an optical pickup device 100 according to a first embodiment will be described below. The method for manufacturing the optical pickup device 100 includes a preparation step, a forming step, a lamination step, and a forming step.

[0070] As in Fig. As shown in Figure 6, a substrate SUB is prepared in the preparation step. The substrate SUB is, for example, a silicon-on-insulator (SOI) substrate. The substrate SUB includes the active layer LA and the support layer LS. The substrate SUB may include the surface oxide film LOS and the intermediate oxide film LOI. The active layer LA and the support layer LS are laminated. The surface oxide film LOS, the active layer LA, the intermediate oxide film LOI, and the support layer LS are laminated in this order.

[0071] Then, as in Fig. As shown in Figure 7, an elastic layer 4 is formed on a side opposite the support layer LS relative to the active layer LA of the substrate SUB. The elastic layer 4 is an elastic material that has a longer fatigue life than metal. The elastic layer 4 contains, for example, silicon (Si) as a material.

[0072] In the present embodiment, the elastic layer 4 is formed on the surface oxide film LOS. The elastic layer 4 can be formed, for example, by chemical vapor deposition (CVD) or the like. When the elastic layer 4 is a silicon (Si) wafer, the elastic layer 4 can be bonded to the surface oxide film LOS, for example, by room-temperature-activated bonding, plasma-activated bonding, or the like.

[0073] Then, as in Fig. As shown in Figure 8, in the forming step, the first elastic layer 41 is formed with respect to the active layer LA of the substrate SUB on the side opposite the support layer LS. In the forming step, the second elastic layer 42 is formed separately from the first elastic layer 41 with respect to the active layer LA of the substrate SUB on the side opposite the support layer LS.

[0074] The first elastic layer 41 is an elastic material that has a longer fatigue life than metal. The first elastic layer 41 contains, for example, silicon (Si) as a material. The second elastic layer 42 is an elastic material that has a longer fatigue life than metal. The second elastic layer 42 contains, for example, silicon (Si) as a material.

[0075] Specifically, in the formation step, the elastic material is partially removed to form the first elastic layer 41 and the second elastic layer 42. The elastic material is partially removed, for example, by etching and patterning.

[0076] The elastic material disposed on the surface oxide film LOS can be etched and patterned. This shapes the elastic material into a desired form to form a first elastic layer 41 and a second elastic layer 42.

[0077] The elastic material can be etched, for example, by wet etching with an etchant or by dry etching such as reactive ion etching (RIE). The etching conditions are selected to achieve high selectivity between the first elastic layer 41 and the second elastic layer 42 and the surface oxide film LOS.

[0078] The first elastic layer 41 and the second elastic layer 42 can preferably be patterned by a photolithographic process using a resist film (not shown) as a protective film. The resist film (not shown) is removed, for example, by O2 ashing or the like.

[0079] As in Fig. As shown in Figure 9, the lower insulating film LI1 is formed on the surface oxide film LOS, the first elastic layer 41, and the second elastic layer 42. The upper insulating film LI2 is formed on the lower insulating film LI1. The upper insulating film LI2 can be formed on the lower insulating film LI1 using the same method as the lower insulating film LI1.

[0080] As in Fig. As shown in Figure 9, the coil line 5 is arranged on the lower insulating film LI1. The coil line 5 is arranged so that it is at least partially exposed from the upper insulating film LI2. The coil line 5 is formed on the lower insulating film LI1 by sputtering or the like. The thus formed coil line 5 can be etched and patterned. This causes the formed coil line 5 to assume a desired shape.

[0081] The coil line 5 arranged on the lower insulating film LI1 can be etched, for example, by wet etching with an etchant or by dry etching such as reactive ion etching (RIE). The etching conditions are selected to achieve high selectivity between the coil line 5 and the lower insulating film LI1. The coil line 5 can preferably be patterned by a photolithographic process using a resist film (not shown) as a protective film.

[0082] The first metal line 61 and the second metal line 62 are arranged on the upper insulating film LI2. The first metal line 61 and the second metal line 62 are electrically connected to the coil line 5. The first metal line 61 and the second metal line 62 can be arranged on the upper insulating film LI2 using the same method as for the coil line 5.

[0083] As in Fig. As shown in Figure 10, in the lamination step, the reflector 10 is laminated onto the active layer LA between the first elastic layer 41 and the second elastic layer 42. The reflector 10 serves to reflect light. The reflector 10 is formed on the upper insulating film LI2 by sputtering or the like. The thus formed reflector 10 can be etched and patterned.

[0084] This causes the formed reflector 10 to assume a desired shape. The reflector 10 arranged on the upper insulating film LI2 can be etched, for example, by wet etching with an etchant or by dry etching such as reactive ion etching (RIE). The etching conditions are selected to achieve high selectivity between the reflector 10 and the upper insulating film LI2. The reflector 10 can preferably be patterned by a photolithographic process using a resist film (not shown) as a protective film.

[0085] Then, as in Fig. 10 and Fig. 3, in the forming step, the support layer LS is removed with respect to the active layer LA on a side opposite the first elastic layer 41 to form the first torsion bar 21. In the forming step, the support layer LS is removed with respect to the active layer LA on a side opposite the second elastic layer 42 to form the second torsion bar 22.

[0086] In a cross section orthogonal to a direction (X-axis direction) in which the rotator 1 is arranged between the first torsion bar 21 and the second torsion bar 22, a vertical dimension (dimension in the Z-axis direction) of the active layer LA is smaller than a horizontal dimension (dimension in the Y-axis direction) of the active layer LA. The first torsion bar 21 and the second torsion bar 22 are formed, and the rotator 1, the first support member 31, and the second support member 32 are formed accordingly. The rotator 1 is arranged between the first torsion bar 21 and the second torsion bar 22. The reflector 10 is mounted on the rotator 1.

[0087] The support layer LS is removed, for example, by patterning. After the support layer LS has been patterned with respect to the active layer LA on a side opposite the reflector 10, the intermediate oxide film LOI is patterned. Although not shown, the surface oxide film LOS and the active layer LA can be patterned with respect to the active layer LA on a side opposite the support layer LS. The support layer LS and the intermediate oxide film LOI can preferably be patterned by a photolithographic process using a resist film (not shown) as a protective film.

[0088] The intermediate oxide film LOI can be etched, for example, by wet etching with an etchant or by dry etching such as reactive ion etching (RIE). In RIE etching of the intermediate oxide film LOI, a Cl4 gas is preferably used as the etchant.

[0089] The support layer LS and the active layer LA are preferably etched by high aspect ratio reactive ion etching (DRIE) according to the Bosch method. This allows the support layer LS and the active layer LA to be etched with a high aspect ratio. After etching the support layer LS and the active layer LA, the resist film is removed. Note that in the present embodiment, the aspect ratio is a ratio between an etching depth and an etching width.

[0090] The following describes a trade-off between the hard spring effect and the maximum deflection angle with reference to an optical pickup device according to a comparative example. The hard spring effect has the effect of increasing a peak frequency.

[0091] The occurrence of the hard spring effect makes it difficult to control the rotation of the rotator 1. The maximum deflection angle is the maximum angle through which the rotator 1 can rotate. The larger the maximum deflection angle, the more the rotator 1 can rotate, allowing the reflector 10 to reflect light over a wide range.

[0092] The hard spring effect (HSE) is caused by tensile stresses resulting from longitudinal expansion and contraction when the rod is twisted, and tends to increase with a deviation of a dimensional ratio between the width of the rod and the thickness of the rod from 1. Therefore, a shape with a small thickness and a large width should be avoided.

[0093] On the other hand, to increase the maximum deflection angle of the rotator, it is necessary to reduce the thickness of the active layer. This is because the maximum deflection angle is inversely proportional to the moment of inertia of the rotator. If the active layer is thin, the width of the rod must be increased to increase the spring constant and thus obtain a desired resonant frequency. The thinner the rod, the more the aspect ratio of the rod cross-section deviates from 1, so the hard spring effect tends to increase. Conversely, increasing the thickness of the active layer can reduce the hard spring effect, but the maximum deflection angle decreases.

[0094] As described above, for a rod with a small thickness and a large width, the strength of the hard spring effect and the maximum deflection angle form a trade-off, and with the MEMS mirror (the optical pickup device 100) according to the related art, the deflection angle may be limited by an increase in the HSE.

[0095] The optical pickup device according to the comparative example does not include the first elastic layer 41, the second elastic layer 42, the surface oxide film LOS, the lower insulating film LI1, and the upper insulating film LI2. The optical pickup device according to the comparative example differs from the optical pickup device 100 according to the first embodiment mainly in that the first elastic layer 41 and the second elastic layer 42 are not included.

[0096] The optical pickup device according to the comparative example includes a recess 11. The optical pickup device according to the comparative example includes a surface layer laminated on the active layer LA.

[0097] In the present embodiment, a bar thickness is a dimension of the first torsion bar 21 and the second torsion bar 22 in the Z-axis direction of the optical pickup 100. A bar width is a dimension of the first torsion bar 21 and the second torsion bar 22 in the Y-axis direction of the optical pickup 100. An aspect ratio is a ratio of the bar width to the bar thickness (bar width / bar thickness).

[0098] As described above, the hard spring effect is related to the aspect ratio. The closer the aspect ratio is to 1, the greater the hard spring effect. Since the bar thickness is smaller than the bar width, the aspect ratio is greater than 1. In a range where the bar thickness is less than or equal to the bar width, the larger the bar width, the closer the aspect ratio is to 1. Thus, the greater the bar thickness, the smaller the hard spring effect. The greater the bar thickness, the more the hard spring effect can be reduced.

[0099] The relationship between the rod thickness and the maximum deflection angle is formulated. Subsequently, the relationship between the rod thickness and the aspect ratio is formulated, and the trade-off between the size of the maximum deflection angle and the reduction of the hard spring effect is demonstrated. The resonance frequency fc of the rotator 1 is expressed by the following equation (1). Equation 1 fc=12πk0I0

[0100] The moment of inertia I0 of the rotator 1 is the sum of the moment of inertia Ia of the active layer LA and the moment of inertia Is of the base layer LS. Therefore, the moment of inertia I0 of the rotator 1 is expressed by the following equation (2). Equation 2 I0=Is+Ia

[0101] The active layer LA is assumed to be a flat plate. Therefore, when the thickness of the active layer LA is multiplied by α, the moment of inertia I of the rotator 1 is expressed by the following equation (3). Equation 3 I=Is+αIa

[0102] A torsional spring constant k of the first torsion bar 21 and the second torsion bar 22 when the thickness of the active layer LA is multiplied by α is expressed by the following equation (4) using equations (1) and (3). Equation 4 k=II0k0=Is+αIaIs+Iak0

[0103] The torsional spring constant k and the maximum deflection angle θ are inversely proportional to each other. Therefore, relative to the deflection angle θ0 at α = 1, the maximum deflection angle θ0 is expressed by the following equation (5). Equation 5 θ=Is+IaIs+αIaθ0

[0104] The torsional spring constant k is expressed by the following equation (6) using the elastic modulus E and Poisson's ratio γ. Note that a in equation (6) is expressed by the following equation (7). Equation 6 k=2aGwt3L=aEwt3L(1+γ) Equation 7 a=13(1−192π5twtanh(πw2t))

[0105] From equations (4) and (6), a bar width w at a bar thickness t = α * t0 is expressed by the following equation (8) when the bar thickness t is smaller than the bar width w. Equation 8 w=Is+αIaIs+Ia(w0−0.63t0)1α3+0.63αt0

[0106] From equation (8) a relationship between the bar width w and the bar thickness t results, which is expressed by the following equation (9). Equation 9 wαt0=Is+αIaIs+Ia(w0−0.63t0)1α4t0+0.63

[0107] As shown in equations (5) and (9), when the ratio of the moment of inertia Ia of the active layer LA to the total moment of inertia I of the rotator 1 is high, the maximum deflection angle and the aspect ratio change greatly in a manner that depends on a change in the thickness of the active layer LA.

[0108] Next, changes in the maximum deflection angle and aspect ratio caused by a change in the thickness of the active layer LA are calculated with reference to a first comparative example and a second comparative example. Table 1 shows parameters of the first comparative example and the second comparative example. Table 1 Parameter ErstesVergleichsbeispiel ZweitesVergleichsbeispiel Siliciumdichte 2331 kg / m 3 Breite des Rotators 2500 µm Länge des Rotators 2500 µm Dicke der Tragschicht 200 µm Rippenbreite 20 µm α 1 1,33 Dicke der aktiven Schicht 15 µm 20 µm Stabbreite 500 µm 276 µm

[0109] In the first comparative example and the second comparative example, the silicon (Si) density is 2331 (kg / m3). The width of the rotator 1 is 2500 µm. The length of the rotator 1 is 2500 µm. A rib width D (cf. Fig. 12) is 20 µm. The thickness of the base layer LS is 200 µm.

[0110] In the first comparison example, α is equal to 1. The thickness of the active layer LA is 15 µm. The rod width is 500 µm. The aspect ratio is 33.3. In the first comparison example, α is equal to 1.33. The thickness of the active layer LA is 20 µm. The rod width is 276 µm. The aspect ratio is 13.8.

[0111] In the first comparative example and the second comparative example, the moment of inertia was calculated based on the dimensions described above, etc. As α changes, the thickness of the active layer LA and the rod width change. As α increases, the thickness of the active layer LA increases.

[0112] Fig. Figure 11 is a graph showing the relationship between the thickness of the active layer LA and θ / 00 using a first axis on the left side of Fig. 11 and shows the relationship between the thickness of the active layer LA and the aspect ratio using a second axis on the right side of Fig. 11 shows.

[0113] As in Fig. As shown in Figure 11, in a region where the width of the rod is larger than the thickness of the rod (a region where the aspect ratio is greater than 1), the larger the maximum deflection angle, the larger the aspect ratio. Thus, the larger the maximum deflection angle, the more likely the hard spring effect is to occur. Therefore, the magnitude of the maximum deflection angle and the reduction of the hard spring effect are in conflict with each other.

[0114] In the second comparative example, α is larger than in the first comparative example. The aspect ratio is smaller than in the first comparative example. The aspect ratio is closer to 1 than in the first comparative example. Therefore, the occurrence of the hard spring effect can be reduced in the second comparative example compared to the first comparative example. However, in the second comparative example, the maximum deflection angle is at least 20% smaller than in the first comparative example.

[0115] Therefore, in order to limit a decrease in the maximum deflection angle and reduce the occurrence of the hard spring effect, it is necessary to limit an increase in the thickness of the first active layer 1A of the rotator 1 and to increase the dimension (rod thickness) of the first torsion bar 21 and the second torsion bar 22 of the optical pickup 100.

[0116] Since the thickness of the active layer LA is not changed in the present embodiment, α = 1 is satisfied, and thus the moment of inertia I of the rotator 1 is I = I0 according to equations (2) and (3). Therefore, according to equation (5), the maximum deflection angle is θ = 00.

[0117] Furthermore, the aspect ratio (bar width / bar thickness) when only the bar thickness is multiplied by α using the first elastic layer 41 and the second elastic layer 42 without changing the moment of inertia I0 of the rotator is expressed by the following equation (10). Equation 10 wαt0=(w0−0.63t0)1α4t0+0.63

[0118] As can be seen from equation (10), the larger α (bar thickness) is, the smaller the aspect ratio (bar width / bar thickness). That is, the aspect ratio (bar width / bar thickness) approaches 1.

[0119] Next, actions and effects of the present embodiment will be described.

[0120] In the optical pickup device 100 according to the first embodiment, as shown in Fig. As shown in Figure 1, the optical pickup device 100 includes a first elastic layer 41 and a second elastic layer 42. The first elastic layer 41 is applied to the first torsion bar 21. The second elastic layer 42 is applied to the second torsion bar 22. This allows the dimensions of the first torsion bar 21 and the second torsion bar 22 of the optical pickup device 100 to be increased in the thickness direction (Z-axis direction).

[0121] The vertical dimension (in the Z-axis direction) of the active layer LA is smaller than the horizontal dimension (in the Y-axis direction) of the active layer LA. Therefore, the aspect ratio of the first torsion bar 21 and the second torsion bar 22 is close to 1 compared to a case where the first elastic layer 41 and the second elastic layer 42 are not arranged.

[0122] Thereby, the hard spring effect of the optical pickup device 100 at the positions of the first torsion bar 21 and the second torsion bar 22 can be reduced compared to the case where the first elastic layer 41 and the second elastic layer 42 are not arranged.

[0123] As in Fig. As shown in Figure 1, the first elastic layer 41 is applied to the first torsion bar 21. The second elastic layer 42 is applied to the second torsion bar 22. This increases the dimension of the first torsion bar 21 and the second torsion bar 22 of the optical pickup device 100 in the thickness direction (Z-axis direction), and limits an increase in the dimension of the active layer LA in the thickness direction (Z-axis direction).

[0124] This, in turn, limits an increase in the dimension of the active layer LA of the rotator 1 in the thickness direction (Z-axis direction). It is therefore possible to limit a decrease in the maximum deflection angle of the rotator 1. This makes it possible to achieve both a reduction in the hard spring effect of the optical pickup 100 at the positions of the first torsion bar 21 and the second torsion bar 22 and a reduction in the maximum deflection angle of the rotator 1.

[0125] As in Fig. As illustrated in Figure 1, the first elastic layer 41 and the second elastic layer 42 are made of an elastic material with a longer fatigue life than metal. This makes the first elastic layer 41 and the second elastic layer 42 less susceptible to deterioration, even when the rotation of the rotator 1 repeatedly stresses the first elastic layer 41 and the second elastic layer 42.

[0126] In particular, it is possible to make the first elastic layer 41 and the second elastic layer 42 less susceptible to deterioration than in a case where the material of the first elastic layer 41 and the second elastic layer 42 is metal. Thus, it is possible to impart high long-term reliability to the optical pickup device 100.

[0127] As in Fig. As shown in Figure 2, the optical scanning device 100 includes the magnet M. The rotator 1 includes the coil line 5. The rotator 1 is rotated by the Lorentz force generated by the current flowing through the coil line 5 and the magnetic force generated by the magnet M. This allows the reflector 10 attached to the rotator 1 to rotate. This, in turn, allows the reflector 10 to reflect light at a desired reflection angle.

[0128] As in Fig. As shown in Figure 2, the material of the first elastic layer 41 and the second elastic layer 42 contains silicon (Si). Silicon (Si) has a longer fatigue life than metal. As a result, the first elastic layer 41 and the second elastic layer 42 have a longer fatigue life than metal. This, in turn, makes the first elastic layer 41 and the second elastic layer 42 less susceptible to deterioration than in a case where the material of the first elastic layer 41 and the second elastic layer 42 contains metal.

[0129] As in Fig. As shown in Figure 2, the material of the first elastic layer 41 and the second elastic layer 42 contains polysilicon. Polysilicon has a longer fatigue life than metal. As a result, the first elastic layer 41 and the second elastic layer 42 have a longer fatigue life than metal. This, in turn, makes the first elastic layer 41 and the second elastic layer 42 less susceptible to deterioration than in a case where the material of the first elastic layer 41 and the second elastic layer 42 contains metal.

[0130] As in Fig. As shown in Figure 2, the material of the first elastic layer 41 and the second elastic layer 42 contains monocrystalline silicon (Si). Monocrystalline silicon (Si) has a longer fatigue life than metal. As a result, the first elastic layer 41 and the second elastic layer 42 have a longer fatigue life than metal.

[0131] This in turn can make the first elastic layer 41 and the second elastic layer 42 less susceptible to deterioration than in a case where the material of the first elastic layer 41 and the second elastic layer 42 contains metal.

[0132] As in Fig. As shown in Figure 2, the material of the first elastic layer 41 and the second elastic layer 42 includes monocrystalline silicon (Si). Therefore, the first elastic layer 41 and the second elastic layer 42 are made, for example, from a monocrystalline silicon wafer. The thickness of the monocrystalline silicon wafer can be more easily controlled than the thickness of polysilicon.

[0133] When the first elastic layer 41 and the second elastic layer 42 are made of polysilicon, the thickness of the first elastic layer 41 and the second elastic layer 42 is controlled based on the time required to form the first elastic layer 41 and the second elastic layer 42 on the surface oxide film LOS.

[0134] When the first elastic layer 41 and the second elastic layer 42 are formed from a monocrystalline silicon wafer, the thickness of the monocrystalline silicon wafer can be controlled in advance during the manufacture of the monocrystalline silicon wafer. This facilitates the control of the thicknesses of the first elastic layer 41 and the second elastic layer 42 compared to a case where the first elastic layer 41 and the second elastic layer 42 contain polysilicon.

[0135] In the optical scanning device 100 according to the first development of the first embodiment, as shown in Fig. 4, the rotator 1 includes a recess 11. As a result, the rotator 1 according to the present embodiment is lighter than the solid rotator 1. As a result, the moment of inertia of the rotator 1 according to the present embodiment is smaller than the moment of inertia of the solid rotator 1. This in turn enables an increase in the maximum deflection angle.

[0136] In the first development of the first embodiment, the ratio between the moment of inertia of the active layer LA and the moment of inertia of the entire rotator 1 is higher than a corresponding ratio for the solid rotator 1. Therefore, if the dimension of the active layer LA increases in the thickness direction (Z-axis direction), the maximum deflection angle decreases compared to the solid rotator 1.

[0137] Since the first elastic layer 41 and the second elastic layer 42 are deposited on the second active layer 31A in the optical pickup device 100 according to the present invention, it is possible to limit an increase in the dimension of the active layer LA in the thickness direction (Z-axis direction). Therefore, in the optical pickup device 100 according to the present invention, it is possible to limit a decrease in the maximum deflection angle even when the rotator 1 includes a recess 11.

[0138] In the optical scanning device 100 according to the second development of the first embodiment, as shown in Fig. As shown in Figure 5, the lower insulating film LI1 is curved upward along the first elastic layer 41 and the second elastic layer 42. This eliminates the need to uniformly space the distance between the upper surface of the lower insulating film LI1 and the surface oxide film LOS. The lower insulating film LI1 can thus be easily processed.

[0139] The method for manufacturing the optical pickup device 100 according to the first embodiment includes the forming step. As shown in Fig. As shown in Figure 8, in the forming step, the first elastic layer 41 is formed with respect to the active layer LA of the substrate SUB on the side opposite the support layer LS. In the forming step, the second elastic layer 42 is formed separately from the first elastic layer 41 with respect to the active layer LA of the substrate SUB on the side opposite the support layer LS.

[0140] As in Fig. 8 and Fig. As illustrated in Figure 3, this increases the thickness dimension (Z-axis direction) of the first torsion bar 21 and the second torsion bar 22 of the optical pickup device 100, and limits the increase in the thickness dimension (Z-axis direction) of the active layer LA. In this way, the hard spring effect can be reduced and a reduction in the maximum deflection angle of the rotator 1 can be limited.

[0141] As in Fig. As shown in Figure 8, in the forming step, the first elastic layer 41 is formed on the side opposite the support layer LS with respect to the active layer LA of the substrate SUB. In the forming step, the second elastic layer 42 is formed separately from the first elastic layer 41 with respect to the active layer LA of the substrate SUB on the side opposite the support layer LS. The first elastic layer 41 is an elastic material having a longer fatigue life than metal. The second elastic layer 42 is an elastic material having a longer fatigue life than metal. Thus, it is possible to impart high long-term reliability to the optical pickup device 100. Second embodiment

[0142] With reference to Fig. 12 and Fig. 13, a configuration of an optical pickup device 100 according to a second embodiment embodying the present invention is described. The second embodiment has the same configuration, manufacturing method, and actions and effects as the first embodiment unless otherwise noted. Therefore, the same components as the components according to the first embodiment are denoted by the same reference numerals to avoid redundant description.

[0143] As in Fig. As shown in Fig. 12, the optical pickup device 100 includes a first conductive path 71 and a second conductive path 72. The first conductive path 71 is arranged on the first support part 31. The second conductive path 72 is arranged on the second support part 32. The rotator 1 of the present embodiment may include a recess 11 (see Fig. Fig. 4).

[0144] The material of the first conductor track 71 and the second conductor track 72 is a metal with high electrical conductivity. Examples of the material of the first conductor track 71 and the second conductor track 72 include aluminum (Al), aluminum nitride (AlN), and the like. The first conductor track 71 extends toward the first torsion bar 21 but does not reach it. The second conductor track 72 extends toward the second torsion bar 22 but does not reach it.

[0145] As in Fig. 13, the first elastic layer 41 includes a first diffusion conduction region 41D. The first diffusion conduction region 41D extends from the first support part 31 to the rotator 1. The second elastic layer 42 includes a second diffusion conduction region 42D. A second diffusion conduction region 42D extends from the second support part 32 to the rotator 1.

[0146] The first diffusion line region 41D of the first elastic layer 41 and the second diffusion line region 42D of the second elastic layer 42 have a higher elastic limit than the first metal line 61 and the second metal line 62. A material of the first diffusion line region 41D and the second diffusion line region 42D contains silicon (Si).

[0147] The first diffusion line region 41D is doped with an impurity. The second diffusion line region 42D is doped with an impurity. This makes the first diffusion line region 41D and the second diffusion line region 42D electrically conductive. The first diffusion line region 41D and the second diffusion line region 42D serve as lines. The first conductive line 71 is electrically connected to the second conductive line 72 via the first diffusion line region 41D, the coil line 5, and the second diffusion line region 42D.

[0148] Examples of the impurity include boron (B) and phosphorus (P). The first elastic layer 41 and the second elastic layer 42 are doped with the impurity at a high doping density. In the present embodiment, the doping density is a density of the impurity used for doping. The doping density is, for example, 1 × 10 20 (cm -3 ).

[0149] Next, actions and effects of the present embodiment will be described.

[0150] In the optical pickup device 100 according to the second embodiment, as shown in Fig. As shown in Figure 13, the first elastic layer 41 includes the first diffusion line region 41D. The second elastic layer 42 includes the second diffusion line region 42D. When a stress applied to the rod lines (first diffusion line region 41D and second diffusion line region 42D or first metal line 61 and second metal line 62) is greater than the elastic limit of the rod lines, the rod lines may deteriorate.

[0151] Therefore, it is necessary that the stress applied to the rod lines be lower than the elastic limit of the rod lines. The larger the maximum deflection angle, the greater the stress acting on the rod lines. Therefore, the higher the elastic limit of the rod lines, the larger the maximum deflection angle can be. The first diffusion line region 41D and the second diffusion line region 42D have a higher elastic limit than the first metal line 61 and the second metal line 62. As a result, the optical pickup device 100 according to the present embodiment can achieve a large deflection angle compared to a case where the first metal line 61 and the second metal line 62 are provided as rod lines.

[0152] As in Fig. As shown in Figure 13, the first elastic layer 41 includes a first diffusion line region 41D. The second elastic layer 42 includes the second diffusion line region 42D. The first diffusion line region 41D and the second diffusion line region 42D have a higher elastic limit than the first metal line 61 and the second metal line 62.

[0153] This can make the rod lines less susceptible to deterioration even at large maximum deflection angles. It is therefore possible to provide an optical scanning device 100 that has higher long-term reliability than an optical scanning device 100 with a first metal line 61 and a second metal line 62.

[0154] As in Fig. As illustrated in Figure 12, the first conductive line 71 extends toward the first torsion bar 21 but does not reach it. The second conductive line 72 extends toward the second torsion bar 22 but does not reach it. This prevents the first conductive line 71 and the second conductive line 72 from rotating even when the rotator 1 rotates together with the first torsion bar 21 and the second torsion bar 22. This can make the first conductive line (71) and the second conductive line (72) less susceptible to deterioration.

[0155] As in Fig. As illustrated in FIG. 13, the first conductive line 71 is electrically connected to the second conductive line 72 via the first diffusion line region 41D, the coil line 5, and the second diffusion line region 42D. This can prevent the first metal line and the second metal line from being deformed along the upward curvature of a corresponding one of the first elastic layer 41 and the second elastic layer (see FIG. Fig. 5). This, in turn, can prevent the wires from being damaged. This is particularly effective in the optical pickup device 100 in which the first elastic layer 41 and the second elastic layer 42 have large dimensions in the thickness direction. Third embodiment

[0156] With reference to Fig. 14 and Fig. 15, a configuration of an optical pickup device 100 according to a third embodiment is described. The third embodiment has the same configuration, manufacturing method, and actions and effects as the first embodiment unless otherwise noted. Therefore, the same components as the components according to the first embodiment are denoted by the same reference numerals to avoid redundant description.

[0157] As in Fig. As shown in FIG. 14, the optical pickup device 100 according to the present embodiment includes a first conductive pattern 71 and a second conductive pattern 72. The first conductive pattern 71 is arranged on the first support member 31. The second conductive pattern 72 is arranged on the second support member 32. The rotator 1 of the present embodiment may include a recess 11 (see FIG. Fig. 4).

[0158] As in Fig. As shown in Figure 15, the active layer LA contains a diffusion conduction region LAD. The diffusion conduction region LAD is doped with an impurity. The doping density is, for example, 1 × 10 20 (cm -3 ). This causes the diffusion conduction region LAD to function as a conductor. The first conductor track 71 is electrically connected to the second conductor track 72 via the diffusion conduction region LAD and the coil line 5.

[0159] As in Fig. As shown in Figure 15, the diffusion conduction region LAD includes a third diffusion conduction region LAD1 and a fourth diffusion conduction region LAD2. The third diffusion conduction region LAD1 is electrically connected to the first conductive trace 71 and the coil line 5. The third diffusion conduction region LAD1 extends from the first support part 31 to the rotator 1. The fourth diffusion conduction region LAD2 is electrically connected to the second conductive trace 72 and the coil line 5. The fourth diffusion conduction region LAD2 extends from the second support part 32 to the rotator 1.

[0160] The material of the active layer LA contains silicon (Si). Therefore, the elastic limit of the diffusion line region LAD is higher than that of the first metal line 61 and the second metal line 62.

[0161] With reference to Fig. 15 to 19, a method for manufacturing an optical pickup device 100 according to the third embodiment will be described below. The method for manufacturing the optical pickup device 100 according to the present embodiment includes a preparation step, a doping step, a forming step, a lamination step, and a forming step.

[0162] As in Fig. As shown in Figure 16, a substrate SUB is prepared in the preparation step. The active layer LA of the substrate SUB contains silicon (Si) as the material. Subsequently, as shown in Fig. As shown in Figure 16, the active layer LA is doped with an impurity in the doping step. As a result, the diffusion conduction region LAD is formed in the active layer LA.

[0163] Then, as in Fig. As shown in Figure 17, a silicon substrate is bonded to a side opposite the support layer LS with respect to the active layer LA. For example, surface-activated bonding and room-temperature-activated bonding are used for bonding. The silicon substrate includes an elastic layer 4 and a surface oxide film LOS.

[0164] In the present embodiment, the elastic layer 4 is, for example, monocrystalline silicon (Si). The surface oxide film LOS is formed on a surface of the elastic layer 4. The surface oxide film LOS is preferably a thermal oxide film with high flatness. The surface oxide film LOS is arranged between the elastic layer 4 and the active layer LA.

[0165] As in Fig. As shown in Figure 18, the first elastic layer 41 and the second elastic layer 42 are subsequently formed in the forming step. The elastic layer 4 (cf. Fig. 17) is partially removed to obtain the first elastic layer 41 and the second elastic layer 42. The elastic layer 4 (cf. Fig. 17) is partially removed by structuring, for example by high aspect ratio reactive ion etching (DRIE) or the like.

[0166] Then, as in Fig. 19, in the lamination step the reflector 10 is laminated onto the active layer LA.

[0167] Then, as in Fig. 19 and Fig. 15, in the forming step, the first torsion bar 21, the second torsion bar 22, the rotator 1, the first support member 31 and the second support member 32 are formed.

[0168] Next, actions and effects of the present embodiment will be described.

[0169] In the optical pickup device 100 according to the third embodiment, as shown in Fig. As shown in Figure 15, the active layer LA includes a diffusion conduction region LAD. The elastic limit of the diffusion conduction region LAD is higher than that of the first metal line 61 and the second metal line 62.

[0170] Thereby, the optical pickup device 100 according to the present embodiment can achieve a large maximum deflection angle compared to a case where the first metal line 61 and the second metal line 62 are provided as rod lines (diffusion line region LAD or first metal line 61 and second metal line 62).

[0171] As in Fig. As shown in Figure 15, the active layer LA includes the diffusion line region LAD. The elastic limit of the diffusion line region LAD is higher than that of the first metal line 61 and the second metal line 62. This can make the rod lines less susceptible to deterioration even at a large maximum deflection angle. It is therefore possible to provide an optical pickup device 100 that has higher long-term reliability than an optical pickup device 100 with a first metal line 61 and a second Metal line 62.

[0172] As in Fig. As illustrated in Figure 15, the first conductive line 71 extends toward the first torsion bar 21 but does not reach it. The second conductive line 72 extends toward the second torsion bar 22 but does not reach it. This prevents the first conductive line 71 and the second conductive line 72 from rotating even when the rotator 1 rotates together with the first torsion bar 21 and the second torsion bar 22. This can make the first conductive line (71) and the second conductive line (72) less susceptible to deterioration.

[0173] As in Fig. As illustrated in FIG. 15, the first conductive line 71 is electrically connected to the second conductive line 72 via the diffusion conductive region LAD and the coil line 5. This can prevent the first metal line 61 and the second metal line 62 from being deformed along the upward curvature of a corresponding one of the first elastic layer 41 and the second elastic layer 42 (see FIG. Fig. 5). This, in turn, can prevent the wires from being damaged. This is particularly effective in the optical pickup device 100 in which the first elastic layer 41 and the second elastic layer 42 have large dimensions in the thickness direction. Fourth embodiment

[0174] With reference to Fig. 20 and Fig. 21, a configuration of an optical pickup device 100 according to a fourth embodiment is described. The fourth embodiment has the same configuration, manufacturing method, and actions and effects as the first embodiment unless otherwise noted. Therefore, the same components as the components according to the first embodiment are denoted by the same reference numerals to avoid redundant description.

[0175] In the present embodiment, as shown in Fig. As shown in Figure 20, the optical scanning device 100 further includes a first comb-shaped electrode E1. The rotator 1 includes a second comb-shaped electrode E2. The optical scanning device 100 does not include a magnet M (see Figure 20). Fig. 1). The optical scanning device 100 according to the present embodiment differs from the optical scanning device 100 according to the first embodiment mainly in that the magnet M (see Fig. 1) is not included.

[0176] As in Fig. As shown in FIG. 20, the optical pickup device 100 includes a third support member 33. The third support member 33 connects the first support member 31 and the second support member 32. The first comb-shaped electrode E1 is attached to the third support member 33. The first comb-shaped electrode E1 extends from the third support member 33 toward the rotator 1 in the Y-axis direction. The rotator 1 of the present embodiment may include a recess 11 (see FIG. Fig. 4).

[0177] As in Fig. As shown in Figure 21, the second comb-shaped electrode E2 is intended to alternately engage with the first comb-shaped electrode E1. The second comb-shaped electrode E2 extends toward the third support member 33 in the Y-axis direction. The first comb-shaped electrode E1 and the second comb-shaped electrode E2 are intended to generate an electrostatic force between the first comb-shaped electrode E1 and the second comb-shaped electrode E2 when a voltage is applied to the first comb-shaped electrode E1 and the second comb-shaped electrode E2.

[0178] The electrostatic force acts on the first comb-shaped electrode E1 and the second comb-shaped electrode E2, causing the first comb-shaped electrode E1 and the second comb-shaped electrode E2 to attract each other. The electrostatic force generates a torque around the first torsion bar 21 and the second torsion bar 22 in the rotator 1. The rotator 1 is rotated by the electrostatic force. This causes the rotator 1 to rotate around the first torsion bar 21 and the second torsion bar 22.

[0179] Next, actions and effects of the present embodiment will be described.

[0180] In the optical scanning device 100 according to a fourth embodiment, as shown in Fig. As shown in Figure 20, the optical pickup device 100 further includes a first comb-shaped electrode E1 and a second comb-shaped electrode E2. The rotator 1 is rotated by the electrostatic force.

[0181] This eliminates the need for the optical scanning device 100 to contain the magnet M (cf. Fig. 1). If the rotator 1 of the optical scanning device 100 is to be rotated by electromagnetic force, the magnet M causes an increase in the dimensions of the optical scanning device 100 (cf. Fig. 1). Since, according to the present embodiment, the optical pickup device 100 does not need to include a magnet M (see Fig. 1), the dimension of the optical scanning device 100 in the Y-axis direction can be reduced. Fifth embodiment

[0182] With reference to Fig. 22 and Fig. 23, a configuration of an optical pickup device 100 according to a fifth embodiment is described. The fifth embodiment has the same configuration, manufacturing method, and actions and effects as the first embodiment unless otherwise noted. Therefore, the same components as the components according to the first embodiment are denoted by the same reference numerals to avoid redundant description.

[0183] As in Fig. 22, the optical scanning device 100 according to the present embodiment further includes a first piezoelectric actuator 81 and a second piezoelectric actuator 82. The optical scanning device 100 includes a third support member 33. The optical scanning device 100 does not include a magnet M (see FIG. Fig. 1). The optical scanning device 100 according to the present embodiment differs from the optical scanning device 100 according to the first embodiment mainly in that the magnet M (see Fig. 1) is not included.

[0184] As in Fig. As shown in Figure 23, the first piezoelectric actuator 81 is connected to the first torsion bar 21. The second piezoelectric actuator 82 is connected to the second torsion bar 22. The rotator 1 is rotated by the first piezoelectric actuator 81 and the second piezoelectric actuator 82. The rotator 1 of the present embodiment may include a recess 11 (see Figure 23). Fig. 4).

[0185] The first piezoelectric actuator 81 includes a first piezoelectric element 80a and a second piezoelectric element 80b that oppose each other across the first torsion bar 21. The second piezoelectric actuator 82 includes a first piezoelectric element 80a and a second piezoelectric element 80b that oppose each other across the second torsion bar 22. The first piezoelectric element 80a and the second piezoelectric element 80b generate pressure when a voltage is applied.

[0186] The first piezoelectric element 80a is operated in antiphase with the second piezoelectric element 80b. As a result, the first piezoelectric element 80a is oscillated in antiphase with the second piezoelectric element 80b.

[0187] The vibrations of the first piezoelectric element 80a and the second piezoelectric element 80b cause the first torsion bar 21 and the second torsion bar 22 to rotate. As a result, the rotator 1 connected to the first torsion bar 21 and the second torsion bar 22 is rotated by the first piezoelectric actuator 81 and the second piezoelectric actuator 82.

[0188] Next, actions and effects of the present embodiment will be described.

[0189] In the optical pickup device 100 according to the fifth embodiment, as shown in Fig. 22, the optical pickup device 100 further includes the first piezoelectric actuator 81 and the second piezoelectric actuator 82. The rotator 1 is rotated by the first piezoelectric actuator 81 and the second piezoelectric actuator 82.

[0190] This eliminates the need for the optical scanning device 100 to contain the magnet M (cf. Fig. 1). If the rotator 1 of the optical scanning device 100 is to be rotated by electromagnetic force, the magnet M causes an increase in the dimensions of the optical scanning device 100 (cf. Fig. 1). Since, according to the present embodiment, the optical pickup device 100 does not need to include a magnet M (see Fig. 1), the dimension of the optical scanning device 100 in the Y-axis direction can be reduced. Sixth embodiment

[0191] With reference to Fig. 24 and Fig. 25, a configuration of an optical pickup device 100 according to a sixth embodiment is described. The sixth embodiment has the same configuration, manufacturing method, and actions and effects as the first embodiment unless otherwise noted. Therefore, the same components as the components according to the first embodiment are denoted by the same reference numerals to avoid redundant description.

[0192] As in Fig. As shown in Figure 24, the optical scanning device 100 according to the present embodiment is applied to a distance measuring device 200. The distance measuring device 200 is a distance measuring device 200 for generating a distance image of a measurement object 300.

[0193] It should be noted that in the present embodiment, the distance image of the measurement object 300 is an image showing a distance between the distance measuring device 200 and the measurement object 300. As shown in Fig. As shown in Figure 24, the distance measuring device 200 includes an optical scanning device 100, a light source 91, a photodetector 92, and an operating unit 93. The optical scanning device 100 is an optical scanning device 100 according to any one of the first to fifth embodiments. The distance measuring device 200 may include a window 94, a beam splitter 95, and a housing 96.

[0194] The light source 91 emits light in the direction of the reflector 10 of the optical scanning device 100. The light source 91 is, for example, a laser light source or the like. Fig. 24 and Fig. 25, the distance measuring device 200 contains a single light source 91, but the distance measuring device 200 may also contain multiple light sources 91. The light is, for example, laser light with a wavelength of 870 nm to 1500 nm.

[0195] The beam splitter 95 is arranged between the light source 91 and the optical scanning device 100. The beam splitter 95 serves to transmit the light emitted by the light source 91 to the optical scanning device 100. The beam splitter 95 reflects the light reflected by the reflector 10 of the optical scanning device 100.

[0196] The optical scanning device 100 is intended to cause the reflector 10 to reflect the light emitted by the light source 91 onto the measurement object 300. The optical scanning device 100 is intended to deflect and reflect incident light. The optical scanning device 100 can serve to reflect the light reflected by the measurement object 300 to the photodetector 92.

[0197] Photodetector 92 is used to receive light. Photodetector 92 is intended, in particular, to detect the light reflected from the measurement object 300.

[0198] The operating unit 93 is connected to the optical scanning device 100 and the light source 91. The operating unit 93 includes, for example, a central processing unit (CPU) or a processor. The operating unit 93 includes, for example, a circuit with an operating function. The operating unit 93 generates the distance image by comparing the light emitted by the light source 91 with the light reflected by the measurement object 300.

[0199] The optical scanning device 100, the light source 91, the photodetector 92, and the operating unit 93 are arranged within the housing 96. The window 94 is formed in the housing 96.

[0200] Next, an optical path when the distance measuring device 200 generates the distance image of the measuring object 300 will be described.

[0201] Light is emitted by light source 91. The light emitted by light source 91 strikes beam splitter 95. The light striking beam splitter 95 is split. Part of the light split by beam splitter 95 strikes reflector 10 of optical scanning device 100. The light striking reflector 10 is reflected by reflector 10 to measurement object 300. The light reflected by reflector 10 is directed through window 94 onto measurement object 300. The light directed onto measurement object 300 is reflected by measurement object 300. The light reflected by measurement object 300 strikes reflector 10 through window 94. The light striking reflector 10 is reflected by reflector 10. The light reflected by reflector 10 hits beam splitter 95. The light hitting beam splitter 95 is split. Part of the light hitting beam splitter 95 is reflected by a reflector of beam splitter 95.The light reflected by the reflector of the beam splitter 95 hits the photodetector 92.

[0202] The operating unit 93 generates the distance image by comparing the light emitted by the light source 91 (outgoing light) with the light reflected by the measurement object 300 (incident light). For example, if the outgoing light is emitted in pulses, the incident light also hits the photodetector 92 in pulses. For example, the operating unit 93 calculates a distance between the distance measuring device 200 and the measurement object 300 based on a time difference between the pulse of the outgoing light and the pulse of the incident light.

[0203] Since the optical scanning device 100 can scan light two-dimensionally, it is possible to obtain a distance image of the surroundings of the distance measuring device 200 based on information about the scanned light.

[0204] With reference to Fig. 25, a configuration of the optical scanning device 100 according to a further development of the sixth embodiment will be described below.

[0205] The optical scanning device 100 according to the development of the sixth embodiment further includes a further optical system 301. The light reflected from the measurement object 300 strikes the distance measuring device 200 via a further optical system 301.

[0206] Next, actions and effects of the present embodiment will be described.

[0207] The distance measuring device 200 according to the sixth embodiment includes an operating unit 93. The operating unit 93 generates the distance image by comparing the light emitted by the light source 91 with the light reflected by the measurement object 300. In this way, a distance image indicating distances to the measurement object 300 is obtained.

[0208] The distance measuring device 200 includes the optical scanning device 100 according to the present invention. This allows the distance measuring device 200 to reduce the hard spring effect. The distance measuring device 200 can limit a decrease in the maximum deflection angle of the rotator 1. The distance measuring device 200 has high long-term reliability.

[0209] It should be noted that the embodiments disclosed herein are in all respects only illustrative and not restrictive. The scope of the present invention is defined by the claims rather than by the foregoing description, and the present invention is intended to encompass the claims, equivalents of the claims, and all modifications within the scope. EXPLANATION OF REFERENCE SYMBOLS 1 rotator 5 coil cable 10 Reflector 11 Deepening 21 first torsion bar 22 second torsion bar 31 first supporting part 32 second supporting part 41 first elastic layer 41D first diffusion conduction area 42 second elastic layer 42D second diffusion conduction area 71 first conductor track 72 second conductor track 81 first piezoelectric actuator 82 second piezoelectric actuator 91 Light source 92 photodetector 93 operating unit 100 optical scanning device 200 distance measuring device E1 first comb-shaped electrode E2 second comb-shaped electrode LA active layer LAD diffusion conduction area LS base layer M Magnet SUB Substrat

Claims

[1] Optical scanning device (100) comprising: - a reflector (10) for reflecting light; - a rotator to which the reflector (10) is applied; - a first torsion bar (21) and a second torsion bar (22) between which the rotator is arranged; - a first support member (31), wherein the first torsion bar (21) is arranged between the first support member (31) and the rotator; - a second support member (32), wherein the second torsion bar (22) is arranged between the second support member (32) and the rotator; - a first elastic layer (41) applied to the first torsion bar (21); - a second elastic layer (42) applied to the second torsion bar (22); - a magnet (M) arranged separately from the rotator; - a first conductor track (71) arranged on the first support part (31); and - a second conductor track (72) arranged on the second support part (32), and wherein - the rotator is rotatable with respect to the first support member (31) and the second support member (32), the first torsion bar (21) and the second torsion bar (22) forming an axis of rotation, - the rotator, the first torsion bar (21) and the second torsion bar (22) contain a common active layer (LA), and wherein - in a cross-section orthogonal to a direction in which the rotator is arranged between the first torsion bar (21) and the second torsion bar (22), a vertical dimension of the active layer (LA) is smaller than a horizontal dimension of the active layer (LA), and - wherein a material of the first elastic layer (41) and the second elastic layer (42) is an elastic material having a higher fatigue life than metal, and wherein - the rotator has a coil line (5) which is applied to the active layer (LA), and wherein - the rotator is to be set in rotation by a Lorentz force generated by a current flowing through the coil line (5) and a magnetic force generated by the magnet (M), and wherein - the first elastic layer (41) has a first diffusion conduction region (41D) doped with an impurity, and wherein - the second elastic layer (42) has a second diffusion conduction region (42D) doped with an impurity, and - the first conductor track (71) is electrically connected to the second conductor track (72) via the first diffusion line region (41D), the coil line (5) and the second diffusion line region (42D). [2] Optical scanning device (100) according to claim 1, wherein the rotator has a recess (11), and the recess (11) is open with respect to the active layer (LA) on a side opposite the reflector (10). [3] The optical pickup device (100) according to claim 1 or 2, wherein the material of the first elastic layer (41) and the second elastic layer (42) contains silicon. [4] The optical pickup device (100) according to claim 3, wherein the material of the first elastic layer (41) and the second elastic layer (42) contains polysilicon. [5] The optical pickup device (100) according to claim 3, wherein the material of the first elastic layer (41) and the second elastic layer (42) contains monocrystalline silicon. [6] Distance measuring device (200) for generating a distance image of a measurement object, wherein the distance measuring device (200) comprises: - an optical scanning device (100) according to one of claims 1 to 5; - a light source (91) for emitting the light in the direction of the reflector (10) of the optical scanning device (100); - a photodetector (92) for receiving the light; and - an operating unit connected to the optical scanning device (100) and the light source (91), wherein the optical scanning device (100) is designed so that the reflector (10) reflects the light emitted by the light source (91) onto the measuring object, and wherein the photodetector (92) detects the light reflected from the measurement object, and wherein the operating unit generates the distance image by comparing the light emitted by the light source (91) with the light reflected from the measurement object. [7] A method of manufacturing an optical scanning device (100), comprising: - Preparing a substrate (SUB) onto which an active layer (LA) and a support layer (LS) are laminated; - forming a first elastic layer (41) and a second elastic layer (42) with respect to the active layer (LA) on a side opposite the support layer (LS), wherein the first elastic layer (41) and the second elastic layer (42) are made of an elastic material having a longer fatigue life than metal and the first elastic layer (41) and the second elastic layer (42) are formed separately from each other; - laminating a reflector (10) for reflecting light on the active layer (LA) between the first elastic layer (41) and the second elastic layer (42); and - Forming the following components: a first torsion bar (21) by removing the support layer (LS) with respect to the active layer (LA) on a side opposite the first elastic layer (41); a second torsion bar (22) by removing the support layer (LS) with respect to the active layer (LA) on a side opposite the second elastic layer (42); a rotator which is arranged between the first torsion bar (21) and the second torsion bar (22) and to which the reflector (10) is applied; a first support part (31), wherein the first torsion bar (21) is arranged between the first support part (31) and the rotator; and a second support part (32), wherein the second torsion bar (22) is arranged between the second support part (32) and the rotator, wherein - in a cross-section orthogonal to a direction in which the rotator is arranged between the first torsion bar (21) and the second torsion bar (22), a vertical dimension of the active layer (LA) is smaller than a horizontal dimension of the active layer (LA), and wherein the optical scanning device (100) further comprises: - a magnet (M) arranged separately from the rotator; - a first conductor track (71) arranged on the first support part (31); and - a second conductor track (72) arranged on the second support part (32), and wherein - the rotator has a coil line (5) which is applied to the active layer (LA), and wherein - the rotator is to be set in rotation by a Lorentz force generated by a current flowing through the coil line (5) and a magnetic force generated by the magnet (M), and wherein - the first elastic layer (41) has a first diffusion conduction region (41D) doped with an impurity, - the second elastic layer (42) has a second diffusion conduction region (42D) doped with an impurity, and - the first conductor track (71) is electrically connected to the second conductor track (72) via the first diffusion line region (41D), the coil line (5) and the second diffusion line region (42D).

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