On axis translational motion stops for movable structure having torsional hinge

• US 6,736,521 B1
• Filed: 01/02/2003
• Issued: 05/18/2004
• Est. Priority Date: 01/02/2003
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Turner, Arthur Monroe
• Primary Examiner(s): SIKDER, MOHAMMAD YUNUS
• Application Number:
  US10/335,750
• Time in Patent Office: 502 Days
• Field of Search: 359/876, 359/877, 359/878, 359/872, 359/223, 359/224, 250/201.1, 250/227.24
• US Class Current: 359/876
• CPC Class Codes: B81B 2201/045 Optical switches
• CPC Class Codes: B81B 3/0051 For defining the movement, i.e. structures that guide or limit the movement of an element mechanical arrangements for preventing or damping vibration or shock H01H3/60
• 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 26/085 the reflecting means being moved or deformed by electromagnetic means
• 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

Abstract

A device 21 comprises a movable structure 44 having a first movable portion 70 hinged to frame portion 60 by a first pair of hinges 81, 82 spaced apart along a first axis 91. The first movable portion 70 has an edge 140 that is substantially perpendicular to the first axis and substantially parallel with and immediately adjacent to an edge 132 of the frame portion 60, such that a tolerance space 120 defined therebetween. At least one projection 122 extends from one or both of the edges 132 and/or 140. The projection 122 is adapted to limit translational motion of the first movable portion 70 relative to the frame portion 60 within the plane. The device 21 motion between the first movable portion 80 and a second pivot axis 112 with translational motion between the first movable portion 70 and the second movable portion 80 limited by a similar projection.

Claims

1. A movable structure comprising:

a support portion;

a movable portion hinged to the frame portion by a first pair of torsional hinges spaced apart along an axis, such that the movable portion can pivot relative to the support portion about the axis;

the movable portion having at least one edge that is substantially perpendicular to said axis and substantially parallel with and immediately adjacent to a corresponding edge of the frame portion so as to define a space between the edge of the movable portion and the corresponding frame portion edge; and

at least one projection extending from at least one edge of the first movable portion and the corresponding frame portion edge, and into said defined space, said projection being adapted to limit translational motion of the movable portion relative to the frame portion.

2. The movable structure of claim 1, wherein the first movable portion of the movable structure has a reflective mirror surface formed thereon.

3. The movable structure of claim 1 wherein said at least one edge of said movable portion comprises at least two edges perpendicular to said first axis and parallel with and adjacent to corresponding edges of said frame portion so as to define at least first and second spaces located one each proximate one each of said pair of spaced torsional hinges, and said at least one projection including at least two projections, one each projection of said at least two projections extending within each of said first and second spaces.

4. The movable structure of claim 1 wherein said at least one edge of said movable portion comprises at least two edges perpendicular to said first axis and parallel with and adjacent to corresponding edges of said frame portion so as to define at least first and second spaces, said at least first and second spaces located one each on each side of one torsional hinge of said pair of torsional hinges and said at least one projection including at least two projections one each projection of said at least two projections extending within each of said first and second spaces.

5. The movable structure of claim 4, wherein said at least two edges comprise at least two pair of edges defining at least first and second pairs of spaces, one each of said at least first and second pairs of spaces located one each proximate one each said pair of torsional hinges and said at least one projection including at least four projections, one each projection of said four projections extending within each space of said first and second pair of spaces.

6. The movable structure of claim 1, wherein said movable portion is an intermediate gimbals portion and further comprising another movable portion hinged to said intermediate gimbals portion by a second pair of torsional hinges spaced apart along another axis such that the second movable portion can pivot relative to the intermediate gimbals portion about a second axis.

7. The movable structure of claim 3, wherein said movable portion is an intermediate gimbals portion and further comprising another movable portion hinged to said intermediate gimbals portion by a second pair of torsional hinges spaced apart along another axis such that the second movable portion can pivot relative to the intermediate gimbals portion about a second axis.

8. The movable structure of claim 4, wherein said movable portion is an intermediate gimbals portion and further comprising another movable portion hinged to said intermediate gimbals portion by a second pair of torsional hinges spaced apart along another axis such that the second movable portion can pivot relative to the intermediate gimbals portion about a second axis.

9. The movable structure of claim 5, wherein said movable portion is an intermediate gimbals portion and further comprising another movable portion hinged to said intermediate gimbals portion by a second pair of torsional hinges spaced apart along another axis such that the second movable portion can pivot relative to the intermediate gimbals portion about a second axis.

10. The movable structure of claim 3, wherein said another movable portion has a reflective mirror surface formed thereon.

11. The movable structure of claim 5, wherein said another movable portion has a reflective mirror surface formed thereon.

12. The movable structure of claim 6, wherein said another movable portion has a reflective mirror surface formed thereon.

13. The movable structure of claim 1, wherein said movable portion further comprises at least another edge that is substantially parallel to said first axis and substantially parallel with and immediately adjacent to a corresponding edge of the frame portion so as to define another space between said edge, and at least another projection extending within said defined another space.

14. The movable structure of claim 6 further comprising:

at least another projection extending from an edge of said another movable portion and another edge of said intermediate gimbals portion, and extending within a space formed between said another edge of said intermediate gimbals (movable) portion and said edge of another movable portion, wherein said another edge of said intermediate gimbals portion is substantially perpendicular to said another axis and substantially parallel with said edge of another movable portion, said at least another projection being adapted to limit translational motion of said another movable portion relative to said intermediate gimbals portion.

15. The movable structure of claim 14, wherein said another axis is substantially perpendicular to said axis.

16. The movable structure of claim 1, wherein said at least one projection has a shape selected from a group consisting of a generally triangular shape, a generally half-circle shape, a generally trapezoidal shape, a generally rectangular shape, a generally rounded shape, and an arbitrary shape.

17. The movable structure of claim 1, wherein said at least one projection comprises at least two projections.

18. The movable structure of claim 14, wherein said at least another projection comprises at least two projections.

19. The movable structure of claim 13, wherein the first movable portion of the movable structure has a reflective mirror surface formed thereon.

20. The movable structure of claim 14, wherein said another movable portion has a reflective mirror surface formed thereon.

21. The movable structure of claim 15, wherein said another movable portion has a reflective mirror surface:

formed thereon.

22. A movable mirror formed in a single piece of substantially planar silicon crystal material, the movable mirror comprising:

a frame portion forming a border around the movable mirror;

an intermediate gimbals portion hinged to the frame portion by a first pair of torsional hinges, each hinge of the first pair of torsional hinges extending along a first axis in said planar material;

each side of the first axis for each hinge of the first hinge pair, including a first space formed between an outer edge of the intermediate gimbals portion and an inner edge of the frame portion, wherein the outer edge of the intermediate gimbals portion is substantially perpendicular to said first axis and substantially parallel with and adjacent to the inner edge of the frame portion at the first space;

at least one projection extending from at least one of the outer edges of the intermediate gimbals portion and the inner edge of the frame portion into said first space, said at least one projection being adapted to limit translational motion of the intermediate gimbals portion relative to the frame portion;

an inner mirror portion hinged to the intermediate gimbals portion by a second pair of torsional hinges, each hinge of the second pair of hinges extending along a second axis in said planar material, wherein the second axis is substantially perpendicular to the first axis, and the inner mirror portion has a reflective mirror surface formed thereon;

each side of the second axis for each hinge of the second hinge pair, including a second space formed between an outer edge of the inner mirror portion and an inner edge of the intermediate gimbals portion, wherein the outer edge of the inner mirror portion is substantially perpendicular to said second axis and substantially parallel with and adjacent to the inner edge of the intermediate gimbals portion at the second space; and

at least another projection extending from at least one of the outer edges of the inner mirror portion and the inner edge of the intermediate gimbals portion into said second space, said at least another projection being adapted to limit translational motion of the inner mirror portion relative to the intermediate gimbals portion.