JP2014160140A - Optical scanning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical scanning device 1 that performs stable driving.SOLUTION: An optical scanning device 1 includes: a plate-like movable unit 10 that includes a main body unit 11, two cantilever portions 12 that extend from a first end portion of the main body unit 11, and a torsion beam portion 14 of which both ends are supported by the two cantilever portions 12 and which includes at the center a mirror portion 15 for reflecting incident light; a fixation portion 20 that holds a second end portion opposed to the first end portion of the main body unit 11; a driving unit 30 that is constituted of a piezoelectric body arranged on the main body unit 11; and an angle measurement unit 40 for measuring rotation information on the mirror portion 15.

Description

  The present invention relates to an optical scanning device that reflects and scans incident light by a mirror.

  Optical scanning devices (hereinafter also referred to as “optical scanners”) that scan incident light (light beams) are used in laser printers, projectors, laser microscopes, and the like. An optical scanner manufactured by using micromachining technology that rotates and vibrates a minimal mirror can be manufactured in batches, and is also attracting attention because it is ultra-compact and driven at high speed.

  For example, an optical scanner 101 shown in FIG. 1 is disclosed in US Pat. No. 8,305,669. The optical scanner 101 includes a flat plate-like movable portion 110, a fixed portion 120 that holds the movable portion 110, and a drive portion 130 made of a piezoelectric body disposed on the movable portion 110. The movable part 110 includes a main body part 111, a cantilever part 112 (112 </ b> A, 112 </ b> B) extending from the main body part 111, and a mirror part 115 that reflects incident light and is supported at both ends by the cantilever part 112. And a torsion beam portion 114 having a central portion. When an AC voltage is applied between the upper and lower electrodes of the drive unit 130, the main body unit 111 vibrates, the vibration is transmitted to the cantilever beam unit 112 and the torsion beam unit 114, and the mirror unit 115 vibrates in a reciprocating manner.

  The optical scanner 101 is small and can be driven at high speed. Furthermore, the optical scanner 101 has an excellent feature of “large displacement” in which the rotation angle of the mirror unit 115, that is, the reflection angle is large.

  However, when the resonance frequency of the optical scanner 101 changes due to a change in ambient temperature or the like, the reflection angle of the incident light beam changes greatly, and there is a possibility that stable driving may not be easy.

  In contrast, an optical scanner 201 shown in FIG. 2 is disclosed in US Pat. No. 8,125,699. The optical scanner 201 has a structure similar to that of the optical scanner 101, but further includes a scanning angle detection sensor AA that detects a deflection angle of the mirror unit 215, a temperature sensor BB, and a stress applying piezoelectric film 220. In the optical scanner 201, the detection result of the scanning angle detection sensor AA is fed back to the driving unit 230 via the optical scanning drive signal generation circuit 221, and the detection result of the temperature sensor BB is returned via the frequency adjustment signal generation circuit 222. Feedback is made to the stress applying piezoelectric film 220. Therefore, the optical scanner 201 can keep the deflection angle of the mirror unit 215, that is, the reflection angle of incident light constant, even if the resonance frequency changes due to a change in ambient temperature or the like.

  However, the above specification does not disclose a specific configuration of the scanning angle detection sensor AA. Also. As shown in FIG. 2, the scanning angle detection sensor AA is not disposed on the movable portion 210, like the temperature sensor BB.

US Pat. No. 8,305,669 US Pat. No. 8,125,699

  An object of the present invention is to provide an optical scanning device that performs stable driving.

  An optical scanning device according to an embodiment of the present invention is supported at both ends by a main body part, two cantilever parts extending from the first end part of the main body part, and the two cantilever parts. A torsion beam part having a mirror part for reflecting incident light in the center, a flat plate-like movable part, and a fixed part for holding a second end part facing the first end part of the main body part A drive unit made of a piezoelectric body disposed in the main body unit, and an angle measurement unit for measuring rotation information of the mirror unit.

  ADVANTAGE OF THE INVENTION According to this invention, the optical scanning device which performs the stable drive can be provided.

It is a perspective view of the conventional imaging device. It is a block diagram of the conventional imaging device. It is a figure for demonstrating the imaging device of 1st Embodiment, (A) is a top view, (B) is a side view. It is a figure for demonstrating the imaging device of the modification 1 of 1st Embodiment, (A) is a top view, (B) is a side view. It is a figure for demonstrating the imaging device of the modification 2 of 1st Embodiment, (A) is a top view, (B) is a side view. It is a figure for demonstrating the imaging device of the modification 3 of 1st Embodiment, (A) is a top view, (B) is a side view. It is a figure for demonstrating the imaging device of the modification 4 of 1st Embodiment, (A) is a top view, (B) is a side view. It is a figure for demonstrating the imaging device of the modification 5 of 1st Embodiment, (A) is a top view, (B) is a side view. It is a figure for demonstrating the imaging device of 2nd Embodiment, (A) is a top view, (B) is a side view. It is a figure for demonstrating the imaging device of 3rd Embodiment, (A) is a top view, (B) is sectional drawing along the 10B-10B line | wire of FIG. 10 (A). It is a schematic diagram for demonstrating the imaging device of 4th Embodiment.

<First Embodiment>
As shown in FIG. 3, the optical scanning device (optical scanner) 1 of this embodiment is similar to the conventional optical scanners 101 and 102 already described. In other words, the optical scanner 1 includes a plate-shaped movable unit 10, a fixed unit 20, and a drive unit 30. The movable part 10 is supported at both ends by a main body part 11, two cantilever parts 12 (12 </ b> A, 12 </ b> B) extending from the first end part of the main body part 11, and two cantilever parts 12. And a torsion beam portion 14 having a mirror portion 15 for reflecting incident light at the center.

  As will be described later, in the optical scanner 1, the movable portion 10 (the main body portion 11, the cantilever portion 12, the torsion beam portion 14) and the mirror portion 15 are made of the same single metal plate and are integrated. They are distinguished for convenience of explanation.

  The fixed portion 20 holds and fixes a second end portion facing the first end portion of the movable portion 10.

  In other words, one end of the main body portion 11 has a cantilever structure constrained by the fixing portion 20, and the other end with the cantilever portion 12 is a free end. And from the free end side of the main-body part 11, the cantilever part 12 is extended in the symmetrical position centering on the mirror part 15. As shown in FIG. A torsion beam portion 14 is connected between the two cantilever portions 12, and a mirror portion 15 is held by the torsion beam portion 14.

  The movable part 10 can be mass-produced at low cost by etching or pressing a metal plate, for example, a stainless steel plate. The mirror unit 15 may be manufactured integrally with the movable unit 10, or may be manufactured separately from the movable unit 10 and then disposed at the center of the torsion beam unit 14. Further, the movable part 10 and the like may be manufactured by processing silicon by a MEMS technique.

  A drive unit 30 is disposed at a substantially central portion of the main body 11. The drive unit 30 is made of a piezoelectric body whose length and thickness expand and contract when a voltage is applied between electrodes (not shown) on both sides. A bulk piezoelectric body or a piezoelectric thin film is used for the drive unit 30. The piezoelectric thin film can be formed on the movable portion 10 by, for example, a sputtering method, a sol-gel method, a MO-CVD (Metal Organic Chemical Vapor Deposition) method, or an AD (aerosol deposition) method. In addition, when the main-body part 11 is a conductor, the main-body part 11 can be used as a lower electrode. Further, the surface of the main body 11 made of a conductor may be covered with an insulating layer. Further, the wiring for applying a voltage signal to the drive unit 30 may be a fine conductive wire or a wiring layer formed on the surface of the main body 11.

  When an AC voltage (drive signal) is applied to the electrodes on both sides from a drive signal generation unit (not shown) controlled by a control unit (not shown), the drive unit 30 expands and contracts in length. When the length of the drive unit 30 is about to be extended, the lower surface of the drive unit 30 cannot be extended because the main body unit 11 to which the drive unit 30 is attached is firmly bonded to the main body unit 11. The portion 30 extends only on its upper surface, and as a result, deforms into an upwardly convex shape. When the length is to be shortened, only the upper surface of the drive unit 30 is contracted, and as a result, it is deformed into a downward convex shape. That is, the main body 11 repeats the upward convex shape deformation and the downward convex shape deformation at a cycle of the frequency (f) of the drive signal.

  When the main body portion 11 vibrates due to deformation, the cantilever portion 12 vibrates in the vertical direction, and the torsion beam portion 14 vibrates. The mirror unit 15 vibrates in a reciprocating manner at a frequency cycle of the drive signal. For this reason, a light beam such as a laser beam incident on the mirror unit 15 is scanned by the rotational vibration of the mirror unit 15.

  When the frequency of the drive signal matches the resonance frequency of the movable part 10, the maximum deflection angle θ of the reciprocating rotational vibration of the mirror part 15 is maximized. For this reason, the frequency of the drive signal of the optical scanner 1, that is, the voltage signal applied to the drive unit 30, is controlled by a control unit (not shown) so as to be the resonance frequency of the movable unit 10.

  In the optical scanner 1, unlike the conventional optical scanning devices 101 and 102, a piezo film 40 that is an angle measuring unit for measuring rotation information of the mirror unit 15 is disposed in the main body unit 11. The piezo film 40 has a structure in which a piezoelectric film such as PVDF (Poly Vinylidene Di Fluoride) having a piezoelectric effect that generates a surface charge according to pressure is bonded.

  When the movable part 10 is deformed by vibration, the piezoelectric film 40 attached to the movable part 10 is also deformed and pressure is applied. Then, since the piezoelectric film 40 generates a potential difference between electrodes (not shown) due to the piezoelectric effect, the deformation amount of the movable portion 10 is output as a voltage.

  As the angle measuring unit, a bulk piezoelectric body or a piezoelectric thin film similar to that of the driving unit 30 may be used as long as the deformation amount of the movable unit 10 can be detected. Further, as the angle measurement unit, an FBG (fiber Bragg grating) sensor in which the wavelength of reflected light changes according to the deformation amount may be provided in the movable unit 10.

  When the angle measuring unit is a piezoelectric thin film, the driving unit 30 and the angle measuring unit can be manufactured at the same time by using a masking technique or an etching technique, so that the manufacturing becomes easy and the cost can be reduced. When the movable part 10 is made of silicon, the angle measuring part may be a piezoresistive element made by ion implantation.

  Here, the phase Δθ of the drive signal that maximizes the vibration amplitude of the main body 11 and the mirror unit 15 is always constant when the resonance frequency of the optical scanner 1 and the rotation angle θ of the mirror unit 15 are constant. Further, the ratio of the absolute values of the amplitudes of the main body 11 and the mirror 15 is uniquely determined by the configuration of the optical scanner 1. For this reason, the voltage generated by the piezo film 40 affixed to the main body portion 11 becomes an AC signal having a correlation with the vibration of the mirror portion 15. Therefore, rotation information (rotation angle θ and phase Δθ) of the mirror unit 15 can be obtained by the piezo film 40.

  The optical scanner 1 whose drive signal is controlled based on the rotation information is applicable to a device that recognizes an object by laser scanning or a device that performs drawing by laser scanning by reflecting a laser beam incident on the mirror unit 15. .

  As the rotation angle θ of the mirror unit 15 is larger, the deformation of the piezo film 40 is larger and the detection sensitivity is improved. Therefore, the optical scanner 1 can be adapted even with a large displacement mirror.

  Here, the amount of vibration deformation of the movable portion 10 has a predetermined distribution in the plane, and includes a so-called “belly” having a large vibration deformation and a so-called “node” having a small vibration deformation. The piezo film 40 is disposed in the vicinity of the vibration of the main body 11 in order to increase the detection sensitivity. Further, the detection sensitivity can be increased as the area of the piezo film 40 increases.

  Since the optical scanner 1 includes the piezo film 40 that is an angle measurement unit for measuring the rotation information of the mirror unit 15, even if the resonance frequency changes due to a change in ambient temperature, the optical scanner 1 can perform stable driving. it can.

  In addition, since the piezo film 40 is disposed on the movable portion 10 in the optical scanner 1, it is not necessary to add a component for detecting rotation information separately from the optical scanner 1, and the size is not increased. Furthermore, since the piezo film 40 is disposed on the main body 11 having a large area, the disposition is easy. Furthermore, when the piezo film 40 is installed on the mirror unit 15, it is necessary to change the thickness and dimensions of the mirror unit 15 and the torsion beam unit 14 accordingly, and the characteristics of the optical scanner 1 such as the deflection angle θ and the resonance frequency are required. May change. However, in the optical scanner 1, the characteristics of the optical scanner 1 do not change.

<Modification of First Embodiment>
Next, optical scanning devices (optical scanners) 1A to 1E according to modifications of the first embodiment will be described. Since the optical scanners 1 </ b> A to 1 </ b> E are similar to the optical scanner 1, the same components are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIGS. 4 to 8, the basic configuration of the optical scanners 1 </ b> A to 1 </ b> E is the same as that of the optical scanner 1 and has the same effect as the optical scanner 1. In both cases, the angle measuring unit is made of a piezoelectric body disposed on the movable unit 10.

<Variation 1 of the first embodiment>
In the optical scanner 1 </ b> A of Modification 1 shown in FIG. 4, the drive unit 30 and the piezo film 40 </ b> A are arranged on different surfaces of the main body 11 of the movable unit 10.

  In the optical scanner 1A, since the piezoelectric film 40A having a large area and a high sensitivity is disposed on the surface where the driving unit 30 is not disposed, the piezoelectric film 40 can be disposed regardless of the position where the driving unit 30 is disposed. It is easy to manufacture and has higher detection sensitivity than the optical scanner 1.

<Modification 2 of the first embodiment>
In the optical scanner 1 </ b> B according to the second modification illustrated in FIG. 5, two drive units 30 </ b> A and 30 </ b> B are disposed on both surfaces of the main body unit 11. In that case, the phase of the applied signal changes depending on the polarization direction of the drive units 30A and 30B. In the case of the arrangement polarized in the same direction toward the main body 11, a driving signal having an opposite phase is applied to the surfaces of the driving units 30A and 30B that are not in contact with the main body 11. In the case of the arrangement in which the main body part 11 is polarized in an alternating direction, the drive signals having the same phase are applied to the surfaces of the drive parts 30A and 30B that are not in contact with the main body part 11. For this reason, for example, when the length of the drive unit 30A is shortened, the length of the drive unit 30B is increased.

  The optical scanner 1B can make the vibration amplitude larger than that of the optical scanner 1 and can reduce the drive signal voltage.

<Modification 3 of the first embodiment>
In the optical scanner 1C of Modification 3 shown in FIG. 6, the piezo films 40C (40C1 and 40C2), which are angle measuring units, are disposed on the two cantilever portions 12 (12A and 12B) of the movable unit 10, respectively. Yes.

  As a natural vibration mode of the optical scanner 1C or the like, a so-called vibration antinode having a large vibration amplitude is formed in the vicinity of the first end where the cantilever 12 and the main body 11 are in contact. For this reason, it is preferable that the piezo film 40 </ b> C is disposed not only on a part of the cantilever part 12 but also on a part of the main body part 11 so as to cover the first end part.

  The optical scanner 1 </ b> C has higher detection sensitivity than the optical scanner 1 because the two piezoelectric films 40 </ b> C are installed at a position where vibration deformation is the largest among the movable parts 10.

  In other words, the piezo film 40 may be disposed anywhere on the movable unit 10 that generates vibration having a correlation with the vibration of the mirror unit 15. However, when it is disposed on the cantilever portion 12, it is possible to stabilize the vibration characteristics by disposing the two piezo films 40C (40C1, 40C2) so as to be symmetrical with respect to the mirror portion 15. Therefore, it is preferable.

<Modification 4 of the first embodiment>
In the optical scanner 1D of Modification 4 shown in FIG. 7, a piezo film 40D as an angle measurement unit is disposed on one cantilever part 12A, and a piezo film 40D is disposed on the other cantilever part 12B. The dummy member 50 having the same mass and the same elastic modulus is disposed.

  Since the optical scanner 1D uses the dummy member 50 that does not require wiring, the optical scanner 1D is easier to manufacture than the optical scanner 1C, and the dummy member 50 is less expensive than the piezo film.

  In addition, you may use the piezo film which does not have a function as an angle measurement part which does not connect wiring as the dummy member 50. FIG.

<Modification 5 of the first embodiment>
In the optical scanner 1E of the modified example 5 shown in FIG. 8, the drive units 30E (30E1, 30E2) are disposed on the two cantilever portions 12 (12A, 12B) of the movable portion 10, respectively. The piezo film 40 </ b> E that is an angle measurement unit is disposed in the main body 11 similarly to the optical scanner 1.

  In the optical scanner 1E, when the drive unit 30E expands and contracts due to the drive signal, the cantilever portion 12 is deformed and vibrates, so that the mirror unit 15 rotates and vibrates. Of course, when the cantilever portion 12 vibrates, the main body portion 11 also vibrates, so that the rotation information of the mirror portion 15 can be measured from the voltage signal output from the piezo film 40E.

  Since the optical scanner 1E does not include the drive unit 30 in the main body 11, the piezoelectric film 40E having a large area can be provided in the main body 11, and thus the detection sensitivity is higher than that of the optical scanner 1. In addition, since the area of the main body 11 can be reduced, the optical scanner 1E can be easily downsized / high-frequency driven.

  As described above, the piezo film serving as the angle measurement unit may be disposed at a predetermined position of the movable unit 10. In addition, the piezo film may be disposed on both surfaces of the movable portion 10, or a plurality of piezo films may be disposed on one surface.

Second Embodiment
Next, an optical scanning device (optical scanner) 1F of the second embodiment will be described. Since the optical scanner 1F is similar to the optical scanner 1 and the like, the same components are denoted by the same reference numerals and description thereof is omitted.

  The angle measurement unit of the optical scanner 1F includes a magnet 60 that is a magnetic field generation unit and a coil 40F that is a magnetic field detection unit. The coil 40F is disposed in the movable part 10, and the magnet 60 is fixed to the fixed part 20 so as to apply a perpendicular magnetic field M in the loop of the coil 40F.

  That is, as shown in FIG. 9, in the optical scanner 1F, the angle measurement unit is a coil 40F that is disposed so as to surround the drive unit 30 and detects the amount of displacement of the movable unit 10, and is in the loop of the coil 40F. A magnet 60 for applying a magnetic field in the vertical direction is provided. As the magnet 60, a known Nd magnet, SmCo magnet, ferrite magnet or the like is used.

  The angle measurement unit of the optical scanner 1F detects the rotation information of the mirror unit 15 based on the principle of electromagnetic induction. That is, when the main body 11 vibrates due to the expansion and contraction of the drive unit 30, an electromotive force is generated in the coil 40F that moves (vibrates) in the magnetic field. The electromotive force, that is, the detection sensitivity of the angle measurement unit is proportional to the magnetic field strength, the cross-sectional area and number of turns (number of turns) of the coil, and the vibration speed. For this reason, although a one-turn coil is illustrated in FIG. 9 for explanation, it is preferable that the number of turns of the coil 40F is large in order to increase detection sensitivity.

  As an optical scanner according to a modification of the present embodiment, the angle measuring unit detects rotation information based on the principle of electromagnetic induction, and various electromotive forces that correlate with the displacement of the main body 11 are efficiently generated in the coil. There are arrangement of coils and magnets.

  For example, a coil may be arranged in the mirror unit 15 and two magnets may be arranged opposite to each other so as to generate a magnetic field perpendicular to the loop surface of the coil on the side surfaces of the cantilevered parts 12A and 12B. . When the coil is disposed on the mirror portion 15, it is preferably disposed on the surface opposite to the reflecting surface. Further, since the mirror portion 15 rotates and vibrates around the torsion beam portion 14, the coil is preferably wound around the torsion beam portion 14 as an axis of symmetry. Note that the rotation information may be detected by an MR sensor or the like instead of the coil.

  Further, a magnetized ferromagnetic material such as a magnet thin film may be disposed on the movable unit 10 and detection may be performed using a coil or the like disposed on the fixed unit 20. The movable part 10 may be made of a ferromagnetic material and a magnetization region may be partially formed.

  In order to prevent magnetic field leakage or to efficiently apply a magnetic field to the coil, a yoke material or a core material made of a soft magnetic material such as permalloy may be provided.

  The angle measurement unit includes a magnetic field generation unit and a magnetic field detection unit, one of which is disposed on the movable unit 10 and the other is fixed to the fixed unit 20, and the rotation information of the mirror unit is measured by the magnetic field detection unit. The optical scanner according to this embodiment and the modified example has the same effect as the optical scanner 1.

<Third Embodiment>
Next, an optical scanning device (optical scanner) 1G of the third embodiment will be described. Since the optical scanner 1G is similar to the optical scanner 1 and the like, the same components are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 10, the optical scanner 1 </ b> G has a frame portion 70 that has a fixed end portion facing the outer peripheral portion of the movable portion 10 via a space (gap) G and is fixed to the fixed portion 20. Further, the angle measuring unit is a counter electrode 71 disposed on the side surface of the movable unit and the side surface of the frame unit 70.

  In other words, the angle measurement unit includes a movable electrode 71A disposed on the movable unit 10 and a fixed electrode 71B disposed to face the movable electrode 71A via the space G, and the movable electrode 71A. Rotation information of the mirror unit 15 is measured based on a change in capacitance between the fixed portion 71B and the fixed electrode 71B.

  The movable part 10 and the frame part 70 may be integrated or separated. In addition, the counter electrode should just be arrange | positioned in at least 1 place of the opposing surface of the movable part 10 and the frame part 70. FIG.

  A location where the counter electrode 71 is disposed is preferably a location where a large displacement occurs due to vibration. The absolute value of the displacement amount is larger in the order of the mirror part 15> the free end tip of the cantilever part 12> the body part 11. However, if one of the counter electrodes 71 is disposed on the mirror section 15, the counter electrodes 71 are too far apart when the mirror section is largely rotated, making it difficult to detect displacement.

  For this reason, as shown in FIG. 10, the location where the counter electrode 71 of the optical scanner 1G is disposed is on the free end side of the cantilever portion 12 where moderately large displacement occurs and / or in the vicinity of the antinode of vibration. Is preferred. Since the optical scanner 1G that detects the displacement of the cantilever portion 12 and the main body portion 11 acquires the rotation information of the mirror portion 15, the rotation information can be easily acquired even with a large displacement mirror.

<Fourth embodiment>
Next, an optical scanning device (optical scanner) 1H according to the fourth embodiment will be described. Since the optical scanner 1H is similar to the optical scanner 1 and the like, the same components are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 11, in the optical scanner 1 </ b> H, the angle measuring unit reflects light (detection beam SB) reflected by the movable unit 10 other than the mirror unit 15 and reflected by the mirror unit 30 (scanning beam SB). The reflection angle of the beam DB) is measured.

  That is, the scanning beam SB is reflected and scanned by the mirror unit 15, while the detection beam DB is reflected by any part of the movable unit 10 other than the mirror unit, and the reflected light is detected by the photodetector. Thus, the displacement of the mirror unit 15 is detected. In FIG. 11, the light source of the light beam and the photodetector of the detection beam DB are not shown.

  In the optical scanner 1H, a detection beam DB having a wavelength different from that of the scanning beam SB is used in order to prevent unnecessary light and stray light from being mixed with the reflected light of the detection beam DB.

  It is preferable that the reflection surface of the detection beam DB is mirror-polished in order to suppress scattering or a reflection film that improves the reflectance is formed.

  In an application for detecting very weak fluorescence such as a biological laser microscope, it is preferable to avoid stray light from entering the optical system of the scanning beam SB as much as possible. The optical scanner 1H detects the amount of mirror displacement with the reflected light of the detection beam DB, but the detection beam DB does not adversely affect the scanning beam SB because the wavelength is different. Note that the reflection surface of the detection beam DB may be a surface opposite to the reflection surface of the scanning beam SB.

  In the optical scanner 1H, it is not necessary to install a detection mechanism in the optical scanner, and the manufacturing cost can be reduced. Further, it is not necessary to install a detection mechanism in the optical scanner 1H, and the size can be reduced.

  Further, various configurations are possible as the angle measurement unit. For example, an angle measurement unit that includes an optical fiber that emits light from the end portion disposed in the movable portion 10 and an optical sensor that detects the direction of the emitted light of the optical fiber disposed in the fixed portion 20. It may be.

  The present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the scope of the present invention.

1, 1A-1H ... Optical scanning device (optical scanner)
DESCRIPTION OF SYMBOLS 10 ... Movable part 11 ... Main-body part 12 ... Cantilever part 14 ... Beam part 15 ... Mirror part 20 ... Fixed part 30 ... Drive part 40 ... Piezo film 40F ... Coil 50 ... Dummy member 60 ... Magnet 70 ... Frame

Claims (9)

A main body part, two cantilever parts extending from the first end of the main body part, and a mirror part for reflecting incident light centered on both ends of the two cantilever parts. A torsion beam portion having a flat plate-like movable portion having,
A fixing portion for holding a second end portion facing the first end portion of the body portion;
A drive unit made of a piezoelectric body disposed in the main body unit;
An optical scanning device comprising: an angle measuring unit for measuring rotation information of the mirror unit.   The optical scanning device according to claim 1, wherein the angle measurement unit is a piezoelectric body disposed on the movable unit.   The optical scanning device according to claim 2, wherein the driving unit and the angle measuring unit are disposed on different surfaces of the movable unit.   The optical scanning device according to claim 2, wherein the driving unit is disposed on both surfaces of the movable unit.   The optical scanning device according to claim 2, wherein the angle measuring unit is disposed in each of the cantilever portions.   The angle measurement unit is disposed on one of the cantilever portions, and a dummy member having the same mass and the same elastic modulus as the displacement detection unit is disposed on the other of the cantilever portions. The optical scanning device according to claim 2.   The angle measurement unit includes a magnetic field generation unit and a magnetic field detection unit, one of which is disposed on the movable unit and the other is fixed to the fixed unit, and the rotation information is measured by the magnetic field detection unit. The optical scanning device according to claim 2.   The angle measurement unit includes a movable electrode disposed on the movable unit, and a fixed electrode fixed to the fixed unit disposed to face the movable electrode through a space. The optical scanning device according to claim 2, wherein the rotation information is measured based on a change in capacitance between the movable electrode and the fixed electrode.   2. The light according to claim 1, wherein the angle measurement unit measures a reflection angle of light having a wavelength different from that of light reflected by the mirror unit and reflected by the movable unit other than the mirror unit. Scanner device.

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