Torsionally hinged devices with support anchors

• US 6,900,918 B2
• Filed: 01/02/2003
• Issued: 05/31/2005
• Est. Priority Date: 07/08/2002
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Turner, Arthur Monroe, Orcutt, John W.
• Primary Examiner(s): Phan, James
• Application Number:
  US10/335,623
• Publication Number:
  US 20040004749A1
• Time in Patent Office: 880 Days
• Field of Search: 359201-202, 359223-226, 347/257, 347/259, 347/260
• US Class Current: 359/224.1
• 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 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G02B 26/085 the reflecting means being moved or deformed by electromagnetic means
• CPC Class Codes: G02B 26/0858 the reflecting means being moved or deformed by piezoelectric 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 functional surface, such as a reflective surface, is supported by a pair of torsional hinges for pivoting about a first axis which in turn is supported by a pair of anchors, according to one embodiment. The reflective surface may be driven into resonant oscillations about the first axis by inertially coupling energy to the device. According to a dual axis embodiment, the reflective surface is attached by torsional hinges to a gimbals portion which in turn is attached to the support members by a second pair of torsional hinges which are orthogonal with the first pair of hinges so as to provide for pivoting of the surface about both pairs of torsional hinges. Thus, a light source may be reflected from a reflective surface to produce a beam sweep and moved orthogonally by the gimbals portion. The devices may be etched from silicon.

Claims

1. A mirror device for providing bi-directional beam movement, comprising:

a reflective surface portion positioned to intercept a beam of light from a light source, said reflective surface pivotally attached to a gimbals portion by a first pair of torsional hinges, and said gimbals portion supported by a second pair of torsional hinges extending to first and second support anchors such that pivoting of said device about said first pair of torsional hinges results in a light beam reflected from said reflective surface moving along a first path and pivoting of said device about said second pair of torsional hinges results in said reflective light moving in a direction substantially orthogonal to said first path;

a first driver for generating vibrational energy in at least one of said first and second support anchors and wherein said vibrational energy is inertially coupled through said second pair of torsional hinges to said gimbals portion and from said gimbals portion through said first pair of torsional hinges to said reflective surface portion for causing resonant pivoting in one direction about said first pair of said torsional hinges and then the opposite direction such that said reflected light beam sweeps or traces across a target area having a first dimension and a second dimension that is orthogonal to said first dimension, said reflected light beam sweeping along said first dimension of said target area as said mirror device pivots about said first pair of torsional hinges; and

a second driver for pivoting said mirror device about said second pair of torsional hinges such that consecutive beam sweeps across said target are repositioned substantially orthogonal with respect to said beam sweep.

2. The mirror device of claim 1 wherein said target area is a rotating cylindrical shaped photosensitive medium.

3. The mirror device of claim 1 wherein said target area is a display screen.

4. A printer comprising:

a light source providing a beam of light;

a first mirror device comprising a first reflective surface portion positioned to intercept said beam of light, a first pair of torsional hinges attached to said reflective surface portion and extending to first and second support anchors for resonant pivoting about a first axis such that light reflected from said first reflective surface sweeps along a first path, said first and second support anchors defining a pivotal axis extending through said reflective surface portion for supporting said mirror device;

a first drive circuit for generating vibrational energy in at least one of said first and second support anchors, said vibrational energy inertially coupled through said first pair of torsional hinges to said reflective surface portion to cause resonant pivoting of said first device about said first axis to provide a resonant beam sweep;

a second mirror device comprising a second reflective surface portion for rotating about a second axis and positioned in said first path such that light reflected from said second reflective surface moves in a second direction substantially orthogonal to said first path;

a moving photosensitive medium having a first dimension and a second dimension orthogonal to said first dimension, and located to receive an image of said reflected light beam as said beam sweeps across said photosensitive medium along said first dimension, said photosensitive medium moving in a direction along said second dimension such that subsequent traces are spaced apart; and

a second drive circuit for rotating said second mirror device about said second axis such that light traces are received on said moving photosensitive medium along a line substantially orthogonal to the movement of said photosensitive medium.

5. A printer comprising:

a light source providing a beam of light;

a mirror device comprising a reflective surface portion positioned to intercept said beam of light from said light source, said reflective surface supported by a first pair of torsional hinges for pivoting about a first axis and supported by a second pair of torsional hinges extending one each to first and second support anchors for pivoting about a second axis substantially orthogonal to said first axis such that pivoting of said device about said first axis results in light reflected from said reflective surface defining a first path, and pivoting of said device about said second axis results in said reflective light moving in a second direction substantially orthogonal to said first path;

a first driver for generating vibrational energy inertially coupled through said second pair of torsional hinges and through said first pair of torsional hinges to said reflective surface portion to cause resonant pivoting of said reflective surface in one direction about said first axis and then the opposite direction;

a moving photosensitive medium having a first dimension and a second dimension orthogonal to said first dimension, and located to receive an image of said reflected light beam as it sweeps or traces across said medium along said first dimension as said mirror device is resonantly pivoting about said first axis, said photosensitive medium moving in a direction along said second dimension such that an image of a subsequent trace of light is spaced from a previous trace; and

a second driver for pivoting about said second axis such that traces are received on said moving photosensitive medium along a line substantially orthogonal to the movement of said photosensitive medium.