Movable reflective device

Patent metadata

Field	Value
Publication number	US-11360300-B2
Application number	US-201716340366-A
Country	US
Kind code	B2
Filing date	Nov 1, 2017
Priority date	Nov 9, 2016
Publication date	Jun 14, 2022
Grant date	Jun 14, 2022

Abstract

An actuator includes an arm starting end having a piezoelectric element, a first end of the arm starting end connected to an inner side of a fixed frame, the arm starting end extending in a straight line, along a Y-axis direction through a gap between the fixed frame and a mirror surface, from the first end to beyond a middle point of an outer side of the mirror surface; an arm terminating end including a first end connected to the middle point of the outer side of the mirror surface, the arm terminating end extending parallel to the arm starting end; and an arm relay that connects a second end of the arm starting end to a second end of the arm terminating end, the arm relay being formed in a zigzag.

First claim

What is claimed is:

1. A movable reflective device comprising:
a fixed frame, the fixed frame having a flat plate-like shape;
a rocker that includes a reflective surface, the rocker being disposed within the fixed frame such that a gap exists between the rocker and the fixed frame, a mirror surface being formed on a first side of the rocker; and
a first actuator that connects the fixed frame to the rocker, the first actuator being a pair of flexible members on which a first piezoelectric element, configured to be capable of expansion and contraction, is formed at a portion extending along a first direction or a portion extending along a second direction that intersects the first direction, each of the pair of members being disposed on each side in the second direction of the rocker, the first actuator being deformed by the expansion and contraction of the first piezoelectric element, thereby causing the rocker to rock with respect to the fixed frame around a first rotational axis, wherein
the first actuator includes:
a first arm starting end on which the first piezoelectric element is formed, a first end of the first arm starting end being connected to an inner side of the fixed frame, the first arm starting end extending in a straight line, along the first direction through the gap between the fixed frame and the rocker, from the first end to beyond a middle point of an outer side of the rocker,
a first arm terminating end including a first end connected to the middle point of the outer side of the rocker, the first arm terminating end extending parallel to the first arm starting end, and
a first arm relay that connects a second end of the first arm starting end to a second end of the first arm terminating end, the first arm relay being formed in a zigzag by alternately connecting a first arm connector extending along the second direction and a first arm extension extending parallel to the first arm starting end and on which the first piezoelectric element is formed, and
the first arm terminating end includes:
a first portion on which the first piezoelectric element is formed, the first portion having a thickness that is less than a thickness of the rocker such that the first portion deflects by the expansion and contraction of the first piezoelectric element to cause the rocker to rock, and
a second portion that has a thickness greater than the thickness of the first portion and connects the first portion to the rocker, wherein the rocker includes:
a movable frame comprising a flat plate-like shape, the movable frame being connected to the first actuator and disposed within the fixed frame such that a gap exists between the movable frame and the fixed frame,
a mirror surface having a flat plate-like shape, the mirror surface including a reflective surface and being disposed within the movable frame such that a gap exists between the mirror surface and the movable frame, and
a second actuator that connects the movable frame to the mirror surface, the second actuator being a pair of flexible members on which a second piezoelectric element, configured to be capable of expansion and contraction, is formed at a portion extending along the first direction or a portion extending along the second direction, each of the pair of members being disposed on each side in the first direction of the mirror surface, the second actuator being deformed by the expansion and contraction of the second piezoelectric element, thereby causing the mirror surface to rock with respect to the movable frame around a second rotational axis that intersects the first rotational axis, wherein the second arm terminating end includes:
a third portion on which the second piezoelectric element is formed, the third portion having a thickness that is less than a thickness of the mirror surface such that the third portion deflects by the expansion and contraction of the second piezoelectric element to cause the mirror surface to rock, and
a fourth portion that has a thickness greater than the thickness of the third portion and connects the third portion to the mirror surface.

2. The movable reflective device according to claim 1 , wherein a weight is attached to the rocker.

3. The movable reflective device according to claim 1 , wherein a boundary between the first portion and the second portion is provided along a direction of the first rotational axis.

4. The movable reflective device according to claim 1 , wherein the thickness of the second portion is the same as the thickness of the rocker.

5. The movable reflective device according to claim 1 , wherein the second actuator includes:
a second arm starting end on which the second piezoelectric element is formed, a first end of the second arm starting end being connected to an inner side of the movable frame, the second arm starting end extending in a straight line, along the second direction through the gap between the movable frame and the mirror surface, from the first end to beyond a middle point of an outer side of the mirror surface,
a second arm terminating end including a first end connected to the middle point of the outer side of the mirror surface, the second arm terminating end extending parallel to the second arm starting end, and
a second arm relay that connects a second end of the second arm starting end to a second end of the second arm terminating end, the second arm relay being formed in a zigzag by alternately connecting a second arm connector extending along the first direction and a second arm extension extending parallel to the second arm starting end and on which the second piezoelectric element is formed.

6. The movable reflective device according to claim 5 , wherein
each of the first actuators is disposed with two-fold rotational symmetry about the mirror surface,
each of the second actuators is disposed with two-fold rotational symmetry about the mirror surface, and
a direction from the first end toward the second end of the first arm starting end, and a direction from the first end toward the second end of the second arm starting end are the same or opposite direction with respect to a rotational direction around the mirror surface.

7. The movable reflective device according to claim 1 , wherein a boundary between the third portion and the fourth portion is provided along a direction of the second rotational axis.

8. The movable reflective device according to claim 1 , wherein the thickness of the fourth portion is the same as the thickness of the mirror surface.

9. A movable reflective device, comprising:
a fixed frame, the fixed frame having a flat plate-like shape;
a rocker that includes a reflective surface, the rocker being disposed within the fixed frame such that a gap exists between the rocker and the fixed frame, a mirror surface being formed on a first side of the rocker; and
a first actuator that connects the fixed frame to the rocker, the first actuator being a pair of flexible members on which a first piezoelectric element, configured to be capable of expansion and contraction, is formed at a portion extending along a first direction or a portion extending along a second direction that intersects the first direction, each of the pair of members being disposed on each side in the second direction of the rocker, the first actuator being deformed by the expansion and contraction of the first piezoelectric element, thereby causing the rocker to rock with respect to the fixed frame around a first rotational axis, wherein
the first actuator includes:
a first arm starting end on which the first piezoelectric element is formed, a first end of the first arm starting end being connected to an inner side of the fixed frame, the first arm starting end extending in a straight

Assignees

• Dai Ichi Seiko Co Ltd

Inventors

• Ogata Kenji
• KUROGI Shogo

Classifications

• G02B26/0858 Primary

  the reflecting means being moved or deformed by piezoelectric means · CPC title

• G02B26/101

  with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129) · CPC title

• B81B2201/042

  Micromirrors, not used as optical switches · CPC title

• B81B2203/0163

  Spring holders · CPC title

• B81B3/0043 Primary

  Increasing angular deflection · CPC title