Deflectable micromirrors with stopping mechanisms

• US 6,741,383 B2
• Filed: 05/24/2002
• Issued: 05/25/2004
• Est. Priority Date: 08/11/2000
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Reflectivity, Inc. (Texas Instruments, Inc.)
• Inventors: Patel, Satyadev R., Heureux, Peter J., Huibers, Andrew G.
• Primary Examiner(s): Dang, Hung Xuan
• Assistant Examiner(s): TRA, TUYEN Q
• Application Number:
  US10/155,744
• Publication Number:
  US 20020196524A1
• Time in Patent Office: 732 Days
• Field of Search: 359/290, 359/223, 359/297, 359/292, 359/295, 359/230, 359/320, 359/323, 359/214
• US Class Current: 359/291
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means

Abstract

A spatial light modulator having a micromirror and one or more deflection limiting mechanisms, and a process for fabrication therefor. In one embodiment, the mirror support structure has a deflection stopping mechanism that limits the tilt angle of the reflective plate. Alternatively, a deflection stopping mechanism can be provided separate from the mirror support structure. The deflection stopping mechanism can be used in conjunction with one or more additional stopping mechanisms such as the abutment of a portion of the reflective plate against the substrate upon which it was constructed and/or abutment of the micromirror on a surface or structure of the circuit substrate.

Claims

1. A spatial light modulator, comprising:

a first substrate;

a deflectable element having a landing pad and that is held on the first substrate via a hinge and stop assembly, the hinge connected to the deflectable element so as to allow the deflectable element to pivot along around an axis, and the stop positioned to arrest the pivoting of the deflectable element by abutting against the landing pad on the deflectable element;

wherein the deflectable element is held on a bottom surface of the first substrate,

wherein the deflectable element has first and second portions such that during deflection of the deflectable element, the second portion moves towards the bottom surface as the first portion moves away from the bottom surface; and

wherein part of said first portion abuts against an area of the hinge and stop assembly.

2. A spatial light modulator, comprising:

a first substrate;

a deflectable element having a landing pad and that is held on the first substrate via a hinge and stop assembly, the hinge connected to the deflectable element so as to allow the deflectable element to pivot along around an axis, and the stop positioned to arrest the pivoting of the deflectable element by abutting against the landing pad on the deflectable element;

wherein the deflectable element is held on a bottom surface of the first substrate,

wherein the deflectable element has first and second portions such that during deflection of the deflectable element, the second portion moves towards the bottom surface as the first portion moves away from the bottom surface;

wherein part of said first portion abuts against an area of the hinge and stop assembly; and

wherein part of said second portion abuts against an area of the first substrate.

3. A spatial light modulator comprising:

a first substrate that is transmissive to visible light;

a deflectable element pivotably held on the first substrate via a hinge;

a stopping mechanism constructed such that when the deflectable element pivots, a portion of the deflectable element abuts against the stopping mechanism so as to stop the movement of the deflectable element;

wherein at least one of the deflectable element, hinge and stopping mechanism is fanned of a laminate of three or more layers; and

wherein an interior layer of the laminate is a ceramic layer, with metal, metal alloy or metal compound layers being disposed within the laminate on opposite sides of the ceramic interior layer.

4. A spatial light modulator comprising:

a first substrate that is transmissive to visible light;

a deflectable element pivotably held on the first substrate via a hinge;

a stopping mechanism constructed such that when the deflectable element pivots, a portion of the deflectable element abuts against the stopping mechanism so as to stop the movement of the deflectable element;

wherein at least one of the deflectable element, hinge and stopping mechanism is formed of a laminate of three or more layers; and

wherein an interior layer of the laminate is a metal, metal alloy or metal compound layer with layers on opposite sides of the interior layer comprising an insulating ceramic compound.

5. A spatial light modulator comprising:

a first substrate that is transmissive to visible light;

a deflectable element pivotably held on the first substrate via a hinge, wherein the deflectable element further comprises a first portion and a second portion such that when the deflectable element pivots, the second portion moves towards the first substrate as the first portion moves away from the first substrate;

a stopping mechanism constructed such that when the deflectable element pivots, a portion of the deflectable element abuts against the stopping mechanism so as to stop the movement of the deflectable element;

wherein at least one of the deflectable element hinge and stopping mechanism is formed of a laminate of three or more layers;

wherein an interior layer of the laminate is a metal, metal alloy or metal compound layer with layers on opposite sides of the interior layer comprising an insulating ceramic compound, wherein the second portion is constructed so as to be capable of abutting against the first substrate; and

wherein the second portion of the deflectable element is constructed so as to be operable of abutting against the first substrate.

6. A spatial light modulator comprising:

a first substrate that is transmissive to visible light;

a deflectable element pivotably held on the first substrate via a hinge;

a stopping mechanism constructed such that when the deflectable element pivots, a portion of the deflectable element abuts against the stopping mechanism so as to stop the movement of the deflectable element;

wherein at least one of the deflectable element, hinge and stopping mechanism is formed of a laminate of three or more layers; and

wherein the hinge connects to the post or wall that comprises the stopping mechanism.

7. A spatial light modulator comprising:

an optically transmissive substrate;

a first gap disposed below the optically transmissive substrate;

a pivotable mirror disposed below the first gap via a hinge;

a second gap disposed below the mirror;

a connector that connects the pivotable mirror with the optically transmissive substrate;

a deflection stopper disposed below the second gap, wherein the deflection stopper has a total thickness and rigidity greater than a total thickness and rigidity of the hinge; and

wherein said connector comprises said deflection stopper.

8. A spatial light modulator comprising:

an optically transmissive substrate;

a first gap disposed below the optically transmissive substrate;

a pivotable minor disposed below the first gap via a hinge;

a second gap disposed below the mirror;

a deflection stopper disposed below the second gap, wherein the deflection stopper has a total thickness and rigidity greater than a total thickness and rigidity of the hinge; and

wherein the deflection stopper is part of the a hinge and post assembly for pivotably holding the mirror to the optically transmissive substrate.

9. A spatial light modulator comprising:

an optically transmissive substrate;

a first gap disposed below the optically transmissive substrate;

a pivotable mirror disposed below the first gap via a hinge;

a second gap disposed below the second gap;

a hinge and post assembly spaced apart from the deflection stopper with the hinge disposed below the second gap; and

a deflection stopper disposed below the second gap, wherein the deflection stopper has a total thickness and rigidity greater than a total thickness and rigidity of the hinge.

10. A spatial light modulator comprising;

an optically transmissive substrate;

a first gap disposed below the optically transmissive substrate;

a pivotable mirror disposed below the first gap via a hinge;

a second gap disposed below the mirror;

a deflection stopper disposed below the second gap;

a third gap below the deflection stopper and another deflection stopper disposed below the third gap; and

wherein the deflection stopper has a total thickness and rigidity greater than a total thickness and rigidity of the hinge.

11. A spatial light modulator comprising:

an optically transmissive substrate;

a first gap disposed below the optically transmissive substrate;

a pivotable mirror disposed below the first gap via a hinge;

a second gap disposed below the mirror;

a first deflection stopper disposed below the second gap;

a third gap below the first deflection stopper;

a second deflection stopper disposed below the third gap;

a fourth gap below the second deflection stopper and a second substrate that comprises an addressing circuitry and an electrode for electrostatically causing the mirror to pivot being disposed below the fourth gap; and

wherein the first deflection stopper has a total thickness and rigidity greater than a total thickness and rigidity of the hinge.

12. A spatial light modulator comprising:

an optically transmissive substrate;

a first gap disposed below the optically transmissive substrate;

a pivotable mirror disposed below the first gap via a hinge;

a second gap disposed below the mirror;

wherein the deflection stopper has a total thickness and rigidity greater than a total thickness and rigidity of the hinge; and

wherein the deflection stopper comprises a protrusion that extends below the second gap and a wall or post which connects to the optically transmissive substrate.