Search

EP-3835846-B1 - ACTUATOR DEVICE AND METHOD FOR MANUFACTURING ACTUATOR DEVICE

EP3835846B1EP 3835846 B1EP3835846 B1EP 3835846B1EP-3835846-B1

Inventors

  • SUZUKI DAIKI

Dates

Publication Date
20260506
Application Date
20190809

Claims (17)

  1. An actuator device (1A, 1B, 1C, 1D, 1E) comprising: a support portion (2); a first movable portion (3); a second movable portion (4) that has a frame shape and surrounds the first movable portion (3); a first connection portion (5, 6) that connects the first movable portion (3) and the second movable portion (4) to each other such that the first movable portion (3) is swingable around a first axis (X); a second connection portion (7, 8) that connects the second movable portion (4) and the support portion (2) to each other such that the first movable portion (3) is swingable around the first axis (X) by vibrating the second movable portion (4); and a drive unit (9, 22), characterised in that the drive unit (9, 22) is configured to apply a drive force to the second movable portion (4), such that the first movable portion (3) is swung around the first axis (X) by vibrating the second movable portion (4), wherein two natural angular frequencies ω 1 and ω 2 , where ω 1 < ω 2 , for vibration of the first movable portion (3) and the second movable portion (4) around the first axis (X) satisfy one of the following first equation, Equation 1, and second equation, Equation 2, and do not satisfy the other, [Equation 1] 0 < 1 − ω 1 ω ii 2 ≤ 0.2 [Equation 2] 0 < ω 2 ω ii 2 − 1 ≤ 0.2 where in the above equations, ω ii = (k i /j i ) 1/2 , k i is a torsional spring constant of the first connection portion (5, 6) around the first axis (X), and j i is an inertia moment of the first movable portion (3) around the first axis (X).
  2. An actuator device (1A, 1B, 1C) comprising: a support portion (2); a first movable portion (3); a second movable portion (4) that has a frame shape and surrounds the first movable portion (3); a first connection portion (5, 6) that connects the first movable portion (3) and the second movable portion (4) to each other such that the first movable portion (3) is swingable around a first axis (X); a second connection portion (7, 8) that connects the second movable portion (4) and the support portion (2) to each other; and a drive unit (9, 21) provided in at least one of the first movable portion (3) and the first connection portion (5, 6) to apply a drive force to the first movable portion (3), wherein two natural angular frequencies ω 1 and ω 2 , where ω 1 < ω 2 , for vibration of the first movable portion (3) and the second movable portion (4) around the first axis (X) satisfy one of the following first equation, Equation 3, and second equation, Equation 4, and do not satisfy the other, [Equation 3] 0 < 4 ω io 2 ω oo 2 − ω 1 2 ≤ 1 [Equation 4] ω oo 2 − ω 2 2 ω io 2 ≤ − 6 where in the above equations, ω io = (k i /j o ) 1/2 , ω oo = (k o /j o ) 1/2 , k i is a torsional spring constant of the first connection portion (5, 6) around the first axis (X), k o is a torsional spring constant of the second connection portion (7, 8) around the first axis (X), and j o is an inertia moment of the second movable portion (4) around the first axis (X), characterised in that the first connection portion (5, 6) includes a widened portion (5b, 6b) which is increased in width as approaching the first movable portion (3) when seen in a direction perpendicular to a plane on which the support portion (2), the first movable portion (3) and the second movable portion (4) are disposed.
  3. The actuator device (1A, 1B, 1D, 1E) according to claim 1 or 2, wherein the second connection portion (7, 8) connects the second movable portion (4) and the support portion (2) to each other such that the second movable portion (4) is swingable around a second axis (Y) intersecting the first axis (X).
  4. The actuator device (1A, 1B, 1C, 1D, 1E) according to any one of claims 1 to 3, wherein the two natural angular frequencies satisfy the first equation and do not satisfy the second equation, and a torsional spring constant of the second connection portion (7, 8) around the first axis (X) is larger than the torsional spring constant of the first connection portion (5, 6) around the first axis (X).
  5. The actuator device (1B) according to claim 4, wherein a total length of the second connection portion (7, 8) is shorter than a total length of the first connection portion (5, 6).
  6. The actuator device (1B) according to claim 4 or 5, wherein the second connection portion (7, 8) includes a plurality of members (7a, 7b), each of which connects the second movable portion (4) and the support portion (2) to each other, and the plurality of members (7a, 7b) are disposed side by side along a direction intersecting the first axis (X), wherein the total length of the second connection portion (7, 8) is the total length obtained by adding the lengths of the plurality of members (7a, 7b).
  7. The actuator device (1B) according to claim 6, wherein the plurality of members (7a, 7b) include a first member (7a) disposed on the first axis (X), and a pair of second members (7b) disposed to interpose the first member (7a) between the second members (7b).
  8. The actuator device (1B) according to claim 7, further comprising: a wiring (14, 15, 16, 17) extending from the second movable portion (4) to the support portion (2) via the second connection portion (7, 8), wherein the wiring (14, 15, 16, 17) is disposed to pass through the first member (7a).
  9. The actuator device (1A, 1B, 1C, 1D, 1E) according to any one of claims 1 to 3, wherein the two natural angular frequencies (ω 1 , ω 2 ) satisfy the second equation and do not satisfy the first equation, and a torsional spring constant of the second connection portion (7, 8) around the first axis (X) is smaller than the torsional spring constant of the first connection portion (5, 6) around the first axis (X).
  10. The actuator device (1A) according to claim 9, wherein a total length of the second connection portion (7, 8) is longer than a total length of the first connection portion (5, 6).
  11. The actuator device (1A) according to claim 9 or 10, wherein the second connection portion (7, 8) extends in a meandering manner.
  12. The actuator device (1A, 1B, 1C, 1D, 1E) according to any one of claims 1 to 11, wherein the support portion (2), the first movable portion (3), the second movable portion (4), the first connection portion (5, 6), and the second connection portion (7, 8) are configured by a semiconductor substrate.
  13. The actuator device (1B) according to any one of claims 1 to 12, further comprising: a sensing coil (24) provided in the first movable portion; and a wiring (16) that is connected to the sensing coil (24) and extends to the second movable portion (7, 8) via the first connection portion (5, 6), wherein the first connection portion (5, 6) is made of a semiconductor material, and a portion of the wiring (16), the portion being located on the first connection portion (5, 6), is configured by a diffusion region (41) where impurities are diffused in the semiconductor material.
  14. The actuator device (1B) according to claim 13, wherein the diffusion region (41) extends from the first connection portion (5, 6) to the first movable portion (3) and the second movable portion (4), and a width of the diffusion region (41) in the first movable portion (3) and the second movable portion (4) is wider than a width of the diffusion region (41) in the first connection portion (5, 6).
  15. The actuator device (1B) according to claim 13 or 14, wherein a portion (16a) of the wiring (16), the portion (16a) being located on the first movable portion (3), and a portion (16b) of the wiring (16), the portion (16b) being located on the second movable portion (4), are made of a metallic material, and a width (W4, W5) of a contact portion between the diffusion region (41) and each of the portion (16a) located on the first movable portion (3) and the portion (16b) located on the second movable portion (4) is wider than a width (W3) of the first connection portion (5, 6).
  16. A method for producing an actuator device (1A, 1B, 1C, 1D, 1E), the actuator device (1A, 1B, 1C, 1D, 1E) including a support portion (2), a first movable portion (3), a second movable portion (4) that has a frame shape and surrounds the first movable portion (3), a first connection portion (5, 6) that connects the first movable portion (3) and the second movable portion (4) to each other such that the first movable portion (3) is swingable around a first axis (X), a second connection portion (7, 8) that connects the second movable portion (4) and the support portion (2) to each other such that the first movable portion (3) is swingable around the first axis (X) by vibrating the second movable portion (4), and a drive unit (9, 22) characterised in that the drive unit (9, 22) is configured to apply a drive force to the second movable portion (4), such that the first movable portion (3) is swung around the first axis (X) by vibrating the second movable portion (4) wherein the actuator is produced such that two natural angular frequencies ω 1 and ω 2 , where ω 1 < ω 2 , for vibration of the first movable portion (3) and the second movable portion (4) around the first axis (X) satisfy one of the following equations, equation 5 and equation 6, and do not satisfy the other, [Equation 5] 0 < 1 − ω 1 ω ii 2 ≤ 0.2 [Equation 6] 0 < ω 2 ω ii 2 − 1 ≤ 0.2 where in the above equations, ω ii = (k i /j i ) 1/2 , k i is a torsional spring constant of the first connection portion (5, 6) around the first axis (X), and j i is an inertia moment of the first movable portion (3) around the first axis (X).
  17. A method for producing an actuator device (1A, 1B, 1C), the actuator device (1A, 1B, 1C) including a support portion (2), a first movable portion (3), a second movable portion (4) that has a frame shape and surrounds the first movable portion (3), a first connection portion (5, 6) that connects the first movable portion (3) and the second movable portion (4) to each other such that the first movable portion (3) is swingable around a first axis (X); a second connection portion (7, 8) that connects the second movable portion (4) and the support portion (2) to each other, and a drive unit (9, 21) that is provided in at least one of the first movable portion (3) and the first connection portion (5, 6) to apply a drive force to the first movable portion (3), wherein the actuator is produced such that two natural angular frequencies ω 1 and ω 2 , where ω 1 < ω 2 , for vibration of the first movable portion (3) and the second movable portion (4) around the first axis (X) satisfy one of the following equations, equation 7 and equation 8, and do not satisfy the other, [Equation 7] 0 < 4 ω io 2 ω oo 2 − ω 1 2 ≤ 1 [Equation 8] ω oo 2 − ω 2 2 ω io 2 ≤ − 6 where in the above equations, ω io = (k i /j o ) 1/2 , ω oo = (k o /j o ) 1/2 , k i is a torsional spring constant of the first connection portion (5, 6) around the first axis (X), k o is a torsional spring constant of the second connection portion (7, 8) around the first axis (X), and j o is an inertia moment of the second movable portion (4) around the first axis (X), characterised in that the first connection portion (5, 6) includes a widened portion (5b, 6b) which is increased in width as approaching the first movable portion (3) when seen in a direction perpendicular to a plane on which the support portion (2), the first movable portion (3) and the second movable portion (4) are disposed.

Description

Technical Field One aspect of the present disclosure relates to an actuator device and a method for producing an actuator device. Background Art As a microelectromechanical systems (MEMS) device, there is known an actuator device including a support portion, a first movable portion, a second movable portion that surrounds the first movable portion, a pair of first connection portions that connect the first movable portion and the second movable portion to each other on a first axis, and a pair of second connection portions that connect the second movable portion and the support portion to each other on the first axis (for example, refer to JP 2005-99760 A). In the actuator device described in Patent Literature 1, the first movable portion is provided with a light reflection portion, and when an AC voltage is applied to the light reflection portion, the second movable portion rotates around the first axis and accordingly, the first movable portion rotates around the first axis. WO 2005/063613 A1, according to its abstract, states a resonance type micro-oscillating member capable of restraining a fluctuation of angular velocity, and specifically states a micro-oscillating member, which is a nested micro-oscillating member, wherein there exist a reference oscillation mode which is the characteristic oscillation mode of a reference frequency, and an even numbered oscillation mode which is the characteristic oscillation mode of a frequency being approximate even number times the reference frequency. US 2005/128552 A1, according to its abstract, states a resonance type torsional vibrator capable of switching to an object driving frequency, which comprises a frequency switching means capable of switching an excitation frequency between at least two levels. EP 3 163 352 A1, according to its abstract, states that, for a case where a drive coil is disposed in a surface of a movable part, the surface being opposite to a mirror, a reduction in size is achieved while a magnetic field exerted on the drive coil is secured. A mirror drive device includes a support part, a movable part, a permanent magnet which forms a magnetic field in the periphery of the movable part, and a circuit board which is disposed between the support part and the permanent magnet in a facing direction of a pair of principal surfaces of the movable part so as to cause the movable part to be positioned at an inside of the circuit board when viewed in the facing direction. The movable part includes a mirror disposition portion, a mirror disposed at a principal surface side, and a drive coil disposed at the principal surface side so as to face the permanent magnet. The support part includes a base portion connected to a connection member and a reinforcing portion which extends from the base portion toward a side away from the permanent magnet and the circuit board. The drive coil is connected to electrodes by lead-out conductors. EP 0 836 265 A1, according to its abstract, states very small planar electromagnetic actuators. A portion of a torsion bar for axially supporting a movable plate of a planar electromagnetic actuator, is made conducting by diffusing boron therein in a high concentration. An external power source can thus be electrically connected to a planar coil via the torsion bar itself. As a result, the possibility of disconnection faults in the electrical wiring due to back and forth twisting movement of the torsion bar is eliminated, thus improving the durability and reliability of the electromagnetic actuator. Summary of Invention Technical Problem In the actuator device as described above, from the viewpoint of high efficiency, it is preferable that a ratio of the deflection angle of the first movable portion to the deflection angle of the second movable portion is large. In addition, the actuator device as described above requires a stable operation. One aspect of the present disclosure is to provide an actuator device capable of realizing a highly efficient and stable operation, and a method for producing such an actuator device. Solution to Problem The invention is defined in the independent claims 1, 2, 16 and 17. Preferred features are subject to the dependent claims. According to one aspect of the present disclosure, there is provided an actuator device including: a support portion; a first movable portion; a second movable portion that has a frame shape and surrounds the first movable portion; a first connection portion that connects the first movable portion and the second movable portion to each other such that the first movable portion is swingable around a first axis; a second connection portion that connects the second movable portion and the support portion to each other such that the first movable portion is swingable around the first axis by vibrating the second movable portion; and a drive unit that that is configured to apply a drive force to the second movable portion, such that the first movable portion is swung aro