Membrane-actuated charge controlled mirror
First Claim
1. A light modulator, comprising:
- a vacuum cell;
a transparent substrate in said vacuum cellan array of electrostatically-actuable pivotable micromirrors on said substrate, said array being held at an reference potential;
an array of insulating posts supported in said vacuum cell;
a thin floating-potential insulating membrane that is supported by said posts above said array of micromirrors;
a collector grid in said vacuum cell that is spaced apart from said insulating membrane opposite said array; and
a source in said vacuum cell that emits primary electrons that are accelerated toward said reference potential through said collector grid and strike the backside of said insulating membrane causing secondary electrons to be ejected and collected on the collector grid thereby leaving a predetermined charge pattern on said membrane that produces finely-resolved attractive electrostatic forces that cause said micromirrors to pivot and deflect towards the membrane,said membrane being thick enough to stop said primary electrons from penetrating through to said micromirrors and thin enough that the fringing fields between the charge pattern and the micromirrors do not degrade the resolution of the attractive electrostatic forces.
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Accused Products
Abstract
An electrostatically actuated micromirror light modulator that exhibits increased deflection range, better charge efficiency and improved electrostatic stability. A thin insulating membrane decouples the electron beam from the micromirror array inside the vacuum cell. The membrane is just thick enough to stop the incident electrons from penetrating through to the mirrors but is thin enough to maintain resolution of the deposited charge pattern. An equipotential layer beneath the mirror array prevents any attractive force from being developed due to the accumulation of static charge on the surface of the light modulator that may otherwise cause the mirror to snap-over and become stuck to the substrate.
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Citations
32 Claims
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1. A light modulator, comprising:
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a vacuum cell; a transparent substrate in said vacuum cell an array of electrostatically-actuable pivotable micromirrors on said substrate, said array being held at an reference potential; an array of insulating posts supported in said vacuum cell; a thin floating-potential insulating membrane that is supported by said posts above said array of micromirrors; a collector grid in said vacuum cell that is spaced apart from said insulating membrane opposite said array; and a source in said vacuum cell that emits primary electrons that are accelerated toward said reference potential through said collector grid and strike the backside of said insulating membrane causing secondary electrons to be ejected and collected on the collector grid thereby leaving a predetermined charge pattern on said membrane that produces finely-resolved attractive electrostatic forces that cause said micromirrors to pivot and deflect towards the membrane, said membrane being thick enough to stop said primary electrons from penetrating through to said micromirrors and thin enough that the fringing fields between the charge pattern and the micromirrors do not degrade the resolution of the attractive electrostatic forces. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A light modulator, comprising:
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a vacuum cell; a charge controlled mirror (CCM) mounted in said vacuum cell, comprising, a transparent substrate; a transparent equipotential layer on said transparent substrate; an array of electrostatically-actuable pivotable micromirrors on said equipotential layer that are both held at an reference potential; an array of insulating posts on said substrate; a floating-potential insulating membrane supported by said posts above said array of micromirrors; and a collector grid spaced apart from said insulating membrane opposite said micromirrors; and a source that emits primary electrons that are accelerated through said collector grid and strike portions of said insulating membrane above respective micromirrors causing secondary electrons to be ejected and collected on the collector grid thereby leaving a predetermined charge pattern on said membrane that produces finely-resolved attractive electrostatic forces that cause said micromirrors to pivot and deflect towards the membrane. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A light modulator comprising:
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a vacuum cell; a charge controlled mirror (CCM) mounted in said vacuum cell, comprising, a transparent substrate; a transparent equipotential layer on said transparent substrate; a conductive grid on said equipotential layer; an array of electrostatically-actuable cantilevered micromirrors, respective pluralities of said micromirrors sharing portions of said conductive grid as common post regions, said conductive grid, said equipotenital layer and said micromirrors being held at an reference potential; an array of insulating floating-potential post-membranes on said micromirror'"'"'s common post regions that fan out above the respective micromirrors that share each said post region; an array of attractor pads on said post-membranes that are aligned to the underlying micromirrors; and a collector grid spaced apart from said insulating post-membranes opposite said micromirrors; and a source that emits primary electrons that are accelerated through said collector grid and strike the attractor pads on said post-membranes causing secondary electrons to be ejected and collected on the collector grid thereby leaving a predetermined charge pattern on said attractor pads that produces finely-resolved attractive electrostatic forces that cause said micromirrors to pivot and deflect towards the post-membranes. - View Dependent Claims (20, 21, 22, 23)
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24. A charge controlled mirror (CCM), comprising:
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a transparent substrate; an array of electrostatically-actuable electrically connected micromirrors on said substrate; an array of insulating posts on said substrate; a floating-potential insulating membrane supported on said posts above said array of micromirrors, said membrane having a thickness that is less than the micromirror-to-membrane spacing; and a collector grid in said vacuum cell that is spaced apart from said insulating membrane opposite said array. - View Dependent Claims (25, 26, 27, 28)
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29. A charge controlled mirror (CCM), comprising:
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a transparent substrate; a transparent equipotential layer on said transparent substrate; an array of electrostatically-actuable cantilevered micromirrors on said equipotential layer; an array of insulating posts on said substrate; a thin floating-potential insulating membrane supported by said posts above said array of micromirrors; and a collector grid in said vacuum cell that is spaced apart from said insulating membrane opposite said array. - View Dependent Claims (30, 31, 32)
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Specification