Micromirror

• US 10,048,487 B2
• Filed: 10/23/2012
• Issued: 08/14/2018
• Est. Priority Date: 12/22/2011
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Nitsche, Heiko, Njikam Njimonzie, Frederic, Schock, Wolfram, Muchow, Joerg, Grutzeck, Helmut, Lestyan, Zoltan
• Primary Examiner(s): Allen, Stephone B
• Assistant Examiner(s): Abdur, Rahman
• Application Number:
  US14/364,991
• Publication Number:
  US 20150036203A1
• Time in Patent Office: 2,121 Days
• Field of Search: 3592012, 3592021, 3592122-2141, 3592231-2241, 3592251-2262, 359871-875, 3562012, 3562021, 3562122-2141, 3562231-2241, 3562251-2262, 356872
• CPC Class Codes: B81B 2201/042 Micromirrors, not used as optical switches
• CPC Class Codes: B81B 2203/0109 Bridges
• CPC Class Codes: B81B 2203/0163 Spring holders
• CPC Class Codes: B81B 3/0043 Increasing angular deflection
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B
• CPC Class Codes: G02B 26/101 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 Class Codes: G02B 26/105 with one or more pivoting mirrors or galvano-mirrors G02B26/101 takes precedence
• CPC Class Codes: G02B 7/1821 for rotating or oscillating mirrors

Abstract

A micromirror including a first layer having a first main extension plane, and a second layer having a second main extension plane, the first main extension plane and the second main extension plane being situated parallel to one another, the first layer and the second layer being sectionally connected to one another via at least one connection area, at least one spring element being implemented in the first layer, a movably suspended mirror plate being implemented in the second layer, the mirror plate having a mirror surface on a first side parallel to the main extension plane and being connected on an opposing second side via the connection area to an anchor of the spring element, a part of the spring element on the second side of the mirror plate being movably situated in relation to the mirror plate. A two-mirror system having such a micromirror is also provided.

Claims

1. A micromirror, comprising:

a first layer having a first main extension plane;

a second layer having a second main extension plane;

the first main extension plane and the second main extension plane being situated parallel to one another;

the first layer and the second layer being sectionally connected to one another via at least one connection area;

at least one spring element being implemented in the first layer;

a movably suspended mirror plate being implemented in the second layer;

the mirror plate having a mirror surface on a first side parallel to the first and second main extension planes and being connected on an opposing second side via the connection area to an anchor of the spring element, wherein;

the anchor is implemented in the first layer,

from a perspective that is perpendicular to the first and second main extension planes, the anchor coupled with the mirror plate has a width that is larger than a width of the spring element in a location remote from the anchor so as to minimize a torque at the mirror plate,

in a direction that is perpendicular to the first and second main extension planes, a thickness of the spring element is equal to a thickness of the anchor; and

a part of the spring element on the second side of the mirror plate being movably situated in relation to the mirror plate, and

in the perspective that is perpendicular to the first and second main extension planes, the spring element has a meander configuration having an outer periphery that at least partially surrounds an outer periphery of the mirror plate formed by an outermost edge of the mirror plate.

2. The micromirror as recited in claim 1, wherein the connection area is formed from an intermediate layer between the first layer and the second layer.

3. The micromirror as recited in claim 1, wherein the connection area is formed from a structured partial area of at least one of the first layer and the second layer.

4. The micromirror as recited in claim 3, wherein a predominant part of the spring element on the second side of the mirror plate is movably situated in relation to the mirror plate.

5. The micromirror as recited in claim 4, wherein the mirror plate is movable around a rotational axis and the spring element has at least one web which is situated parallel to the rotational axis.

6. The micromirror as recited in claim 5, wherein the spring element has at least three webs which are situated parallel to the rotational axis.

7. The micromirror as recited in claim 1, wherein the anchor is situated under a surface center of gravity of the mirror plate.

8. The micromirror as recited in claim 1, wherein the spring element has a first extension perpendicular to the first main extension plane and a second extension parallel to the first main extension plane, the first extension being greater by the factor of 2, than the second extension.

9. The micromirror as recited in claim 1, wherein the spring element has a first extension perpendicular to the first main extension plane and a second extension parallel to the first main extension plane, the first extension being greater by the factor of 10, than the second extension.

10. The micromirror as recited in claim 1, wherein the micromirror has at least two spring elements which are connected to a shared anchor.

11. The micromirror as recited in claim 1, wherein the micromirror has at least two spring elements which are each connected to a separate anchor.

12. The micromirror as recited in claim 1, wherein a first frame is implemented in the first layer and the spring element is connected to the first frame.

13. The micromirror as recited in claim 12, wherein a second frame, which is connected to the first frame via the connection area, is implemented in the second layer.

14. The micromirror as recited in claim 1, wherein the at least one connection area is an intermediate layer directly connected to the first layer and the second layer.

15. The micromirror as recited in claim 1, wherein the anchor and the spring element are co-planar with respect to each other in the first main extension plane.

16. The micromirror as recited in claim 1, wherein:

in the meander configuration of the spring element;

a first section of the spring element runs perpendicular to a rotational axis of the mirror plate,

a second section of the spring element includes a first end connected to the first section and runs parallel to the rotational axis,

a third section of the spring element has a first end connected to a second end of the second section and runs perpendicular to the rotational axis,

a fourth section of the spring element has a first end connected to a second end of the third section and runs parallel to the rotational axis, and

the first section, the second section, the third section, and the fourth section are co-planar with each other in the first main extension plane.

17. The micromirror as recited in claim 16, wherein:

the second and fourth sections are longer than the first and third sections in the first main extension plane.

18. The micromirror as recited in claim 1, wherein the connection area connects an edge periphery of the first layer to an edge periphery of the second layer.

19. The micromirror as recited in claim 1, wherein the thickness of the spring element and the anchor is greater than an extension of the spring element parallel to the first main extension plane and an extension of the anchor parallel to the first main extension plane by the factor of 10.

20. The micromirror as recited in claim 1, wherein the spring element extends under the mirror in two directions that are at an angle to one another.

21. The micromirror as recited in claim 20, wherein the angle is ninety degrees.

22. The micromirror as recited in claim 1, further comprising an electromagnetic drive situated in the first plane.

23. The micromirror as recited in claim 1, wherein:

the anchor includes a first anchor section and a second anchor section, and

the first anchor section and the second anchor section are displaced from a rotational axis of the mirror plate so that, in the direction that is perpendicular to the first and second main extension planes, the rotational axis does not intersect the first anchor and does not intersect the second anchor.

29. The micromirror as recited in claim 1, wherein the thickness of the spring element and the anchor is greater than an extension of the spring element parallel to the first main extension plane and an extension of the anchor parallel to the first main extension plane by the factor of 2.

24. A two-mirror system, comprising:

a first micromirror, and at least having one second micromirror, each of the micromirrors including a first layer having a first main extension plane, a second layer having a second main extension plane, the first main extension plane and the second main extension plane being situated parallel to one another, the first layer and the second layer being sectionally connected to one another via at least one connection area, at least one spring element being implemented in the first layer, a movably suspended mirror plate being implemented in the second layer, the mirror plate having a mirror surface on a first side parallel to the first and second main extension planes and being connected on an opposing second side via the connection area to an anchor of the spring element, and a part of the spring element on the second side of the mirror plate being movably situated in relation to the mirror plate, wherein the anchor is implemented in the first layer, and wherein, from a perspective that is perpendicular to the first and second main extension planes, the anchor coupled with the mirror plate has a width that is larger than a width of the spring element in a location remote from the anchor so as to minimize a torque at the mirror plate;

wherein;

the two mirror system represents a 2D scanner, the first mirror having a first rotational axis x and the second micromirror having a second rotational axis y which is perpendicular to the first rotational axis of the first mirror, the second micromirror being situated opposite the first mirror, in such a way that a laser beam which irradiates both mirrors is deflectable in two directions;

in a direction that is perpendicular to the first and second main extension planes, a thickness of the spring element is equal to a thickness of the anchor, and

in the perspective that is perpendicular to the first and second main extension planes, the spring element has a meander configuration having an outer periphery that at least partially surrounds an outer periphery of the mirror plate formed by an outermost edge of the mirror plate.

25. The two-way mirror system as recited in claim 24, wherein the anchor and the spring element are co-planar with respect to each other in the first main extension plane.

26. The two-mirror system as recited in claim 24, wherein:

in the meander configuration of the spring element;

a first section of the spring element runs perpendicular to a rotational axis of the mirror plate,

a second section of the spring element includes a first end connected to the first section and runs parallel to the rotational axis,

a third section of the spring element has a first end connected to a second end of the second section and runs perpendicular to the rotational axis,

a fourth section of the spring element has a first end connected to a second end of the third section and runs parallel to the rotational axis, and

the first section, the second section, the third section, and the fourth section are co-planar with each other in the first main extension plane.

27. The two-mirror system as recited in claim 26, wherein:

the second and fourth sections are longer than the first and third sections in the first main extension plane.

28. The two-mirror system as recited in claim 24, wherein the connection area connects an edge periphery of the first layer to an edge periphery of the second layer.

30. The two-mirror system as recited in claim 24, wherein the thickness of the spring element and the anchor is greater than an extension of the spring element parallel to the first main extension plane and an extension of the anchor parallel to the first main extension plane by the factor of 2.

31. The two-mirror system as recited in claim 24, wherein the thickness of the spring element and the anchor is greater than an extension of the spring element parallel to the first main extension plane and an extension of the anchor parallel to the first main extension plane by the factor of 10.

32. The two-mirror system as recited in claim 24, wherein the spring element extends under the mirror in two directions that are at an angle to one another.

33. The two-mirror system as recited in claim 24, wherein the angle is ninety degrees.

34. The two-mirror system as recited in claim 24, further comprising an electromagnetic drive situated in the first plane.

35. The two-mirror system as recited in claim 24, wherein:

the anchor includes a first anchor section and a second anchor section, and

the first anchor section and the second anchor section are displaced from a rotational axis of the mirror plate so that, in the direction that is perpendicular to the first and second main extension planes, the rotational axis does not intersect the first anchor and does not intersect the second anchor.