Method and apparatus for modulating an incident light beam for forming a two-dimensional image
First Claim
1. An optical system for displaying an image comprising:
- a. a plurality of elongated elements, each element having an approximately flat reflective surface disposed between two ends, the elements arranged parallel to each other and suspended by their respective ends above a substrate, the elongated elements grouped according to a plurality of display elements arranged in a single linear array;
b. means for deforming selected ones of the elongated elements toward the substrate thereby entering a deformed state wherein the approximately flat reflective surface of each selected element moves toward the substrate by a grating amplitude without the selected elongated elements contacting the substrate such that when the elongated elements corresponding to a display element are undeformed, an incident beam of light is reflected by the display element, and further such that when alternate ones of elongated elements corresponding to the display element are selectively deformed, the incident beam of light is diffracted by the display element, wherein a distance of movement of the selected ones of the elongated elements determines an intensity for the corresponding display element;
c. an optical arrangement for forming the image according to a respective intensity formed by each display element; and
d. a reflective element disposed over the two ends of each elongated element in a plane parallel to the reflective surfaces of undeformed elongated elements by distance equal to a whole number or zero multiplied by half the wavelength of the incident beam of light.
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0 Petitions
Accused Products
Abstract
An apparatus and method for modulating an incident light beam for forming a two-dimensional projection image. The apparatus includes a plurality of elongated elements each having a reflective surface. The elongated elements are suspended substantially parallel to each other above a substrate with their respective ends supported, forming a column of adjacent reflecting surfaces grouped according to display elements. Alternate ones of each group are deformable by a applying a voltage with respect to the substrate. An approximately flat center section of each deformed element is substantially parallel to and a predetermined distance from a center section of each undeformed element. Limiting the predetermined distance avoids hysteresis in deforming the elements and avoids adhesion of the elements to the substrate. A light beam incident to the column of adjacent reflecting surfaces is reflected from a group of elongated elements when the alternate ones are undeformed and diffracted when alternate ones are deformed. A distance of movement is controlled or a ratio of between reflection and diffraction periods determines a display intensity for the corresponding display element. Diffracted light is collected by a lens and reflected by a scanning mirror into an eyepiece or onto a display screen. A light shield having a slit of predetermined width is positioned at the pupil such that light collected by the lens other than light diffracted from the center sections of the elongated elements is prevented from passing through the slit. The scanning mirror sweeps a two-dimensional color image into the eyepiece or onto the display screen.
521 Citations
61 Claims
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1. An optical system for displaying an image comprising:
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a. a plurality of elongated elements, each element having an approximately flat reflective surface disposed between two ends, the elements arranged parallel to each other and suspended by their respective ends above a substrate, the elongated elements grouped according to a plurality of display elements arranged in a single linear array;
b. means for deforming selected ones of the elongated elements toward the substrate thereby entering a deformed state wherein the approximately flat reflective surface of each selected element moves toward the substrate by a grating amplitude without the selected elongated elements contacting the substrate such that when the elongated elements corresponding to a display element are undeformed, an incident beam of light is reflected by the display element, and further such that when alternate ones of elongated elements corresponding to the display element are selectively deformed, the incident beam of light is diffracted by the display element, wherein a distance of movement of the selected ones of the elongated elements determines an intensity for the corresponding display element;
c. an optical arrangement for forming the image according to a respective intensity formed by each display element; and
d. a reflective element disposed over the two ends of each elongated element in a plane parallel to the reflective surfaces of undeformed elongated elements by distance equal to a whole number or zero multiplied by half the wavelength of the incident beam of light. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. An optical system for displaying an image comprising:
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a. a plurality of elongated elements, each element having an approximately flat reflective surface disposed between two ends, the elements arranged parallel to each other and suspended by their respective ends above a substrate, the elongated elements grouped according to a plurality of display elements arranged in a single linear array;
b. means for deforming selected ones of the elongated elements toward the substrate surface thereby entering a deformed state wherein the approximately flat reflective surface of each selected element moves toward the substrate by a grating amplitude of a whole number or zero multiplied by one-half a wavelength of an incident beam of light plus approximately one-fourth the wavelength of the incident beam of light, without the selected elongated elements contacting a surface of the substrate such that when the elongated elements corresponding to a display element are undeformed, an incident beam of light is reflected by the display element, and further such that when alternate ones of elongated elements corresponding to the display element are selectively deformed, the incident beam of light is diffracted by the display element, wherein a ratio of a period of reflection to a period of diffraction determines an intensity for the corresponding display element;
c. an optical arrangement for forming the image according to a respective intensity formed by each display element; and
d. a reflective element disposed over the two ends of each elongated element in a plane parallel to the reflective surfaces of undeformed elongated elements by distance equal to a whole number or zero multiplied by half the wavelength of the incident beam of light. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30)
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31. An optical system for displaying an image comprising:
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a. a plurality of elongated elements, each having an approximately flat reflective surface disposed between two ends, the elements arranged parallel to each other and suspended by their respective ends above a substrate by a distance the elements grouped according to a plurality of display elements arranged in a single column;
b. means for placing selected ones of the elongated elements in a deformed state wherein the incident beam of light is diffracted by moving the approximately flat reflective surface of the selected ones toward the substrate by a grating amplitude of approximately one-fourth to one-third of the distance and for returning the selected ones of the elongated elements to an undeformed state wherein the incident beam of light is reflected, wherein a ratio of a period of reflection to a period of diffraction determines an intensity for the corresponding display element;
c. an optical arrangement for forming the image according to a respective intensity formed by each display element; and
d. a reflective element disposed over the two ends of each elongated element in a plane parallel to the reflective surfaces of undeformed elongated elements by distance equal to a whole number or zero multiplied by half the wavelength of the incident beam of light. - View Dependent Claims (32, 33, 34, 35, 36, 37)
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38. A method of forming an image comprising steps of:
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a. causing a beam of light to impinge upon a plurality of elongated elements, each element having an approximately flat reflective surface disposed between two ends, the elements arranged parallel to each other and suspended by their respective ends above a substrate by a distance, the elements grouped according to a plurality of display elements arranged in a single column;
b. deforming selected ones of the elongated elements toward the substrate by moving the approximately flat reflective surface of the selected ones toward the substrate by a grating amplitude of approximately one-fourth to one-third of the distance thereby causing the selected ones to be in a deformed state wherein the incident beam of light is diffracted, wherein a ratio of a period of reflection to a period of diffraction determines an intensity for the corresponding display element;
c. returning the selected ones of the elongated elements to an undeformed state wherein the incident beam of light is reflected;
d. forming an image according to a respective intensity formed by each display element; and
e. preventing light diffracted by other than the approximately flat center portions from being displayed where the means for preventing comprises a reflective element disposed over the two ends of each elongated element in a plane parallel to the reflective surfaces of undeformed elongated elements by distance equal to a whole number or zero multiplied by half a wavelength of the beam of light. - View Dependent Claims (39, 40, 41, 42, 43, 44, 45)
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46. A method of forming an image comprising steps of:
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a. causing a beam of light to impinge upon a plurality of elongated elements, each element having an approximately flat reflective surface disposed between two ends, the elements arranged parallel to each other and suspended by their respective ends above a substrate, the elements grouped according to a plurality of display elements arranged in a single column;
b. deforming selected ones of the elongated elements toward the substrate surface thereby causing the selected ones to be in a deformed state wherein the approximately flat reflective surface of each selected element is moved toward the substrate by a grating amplitude of a whole number or zero multiplied by one-half the wavelength of the beam of light plus approximately one-fourth the wavelength of the incident beam of light, without the selected elongated elements contacting a surface of the substrate, wherein when the elongated elements corresponding to a display element are undeformed, the beam of light is reflected by the display element, and when alternate ones of elongated elements corresponding to the display element are selectively deformed, the beam of light is diffracted by the display element, wherein a ratio of a period of reflection to a period of diffraction determines an intensity for the corresponding display element;
c. forming an image according to a respective intensity formed by each display element; and
d. preventing light diffracted by other than the approximately flat center portions from being displayed where the means for preventing comprises a reflective element disposed over the two ends of each elongated element in a plane parallel to the reflective surfaces of undeformed elongated elements by distance equal to a whole number or zero multiplied by half a wavelength of the beam of light. - View Dependent Claims (47, 48, 49, 50, 51, 52, 53, 54)
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55. A modulator for modulating an incident beam of light having a wavelength, the modulator comprising:
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a. a plurality of elongated elements, each having an approximately flat reflective surface disposed between two ends, the elements arranged parallel to each other and suspended by their respective ends by integrally formed posts above a substrate; and
b. means for deforming selected ones of the elongated elements toward the substrate thereby entering a deformed state wherein the approximately flat reflective surface of each selected element moves toward the substrate by a grating amplitude without the selected elongated elements contacting the substrate.
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56. A modulator for modulating an incident beam of light having a wavelength within a visible range of wavelengths, the modulator comprising:
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a. a plurality of elongated elements, each having an approximately flat reflective surface disposed between two ends, the elements arranged parallel to each other and suspended by their respective ends by integrally formed posts above a substrate; and
b. means for deforming selected ones of the elongated elements toward the substrate surface thereby entering a deformed state wherein the approximately flat reflective surface of each selected element moves toward the substrate by a grating amplitude of a whole number or zero multiplied by one-half the wavelength of the incident beam of light plus approximately one-fourth the wavelength of the incident beam of light, without the selected elongated elements contacting a surface of the substrate.
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57. A modulator for modulating an incident beam of light, the modulator comprising:
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a. a plurality of elongated elements, each having an approximately flat reflective surface disposed between two ends, the elements arranged parallel to each other and suspended by their respective ends by integrally formed posts above a substrate by a distance; and
b. means for placing selected ones of the elongated elements in a deformed state wherein the incident beam of light is diffracted by moving the approximately flat reflective surface of the selected ones toward the substrate by a grating amplitude of approximately one-fourth to one-third of the distance and for returning the selected ones of the elongated elements to an undeformed state wherein the incident beam of light is reflected.
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58. A method of modulating an incident beam of light having a wavelength, the method comprising steps of:
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a. causing the beam of light to impinge upon a plurality of elongated elements, each having an approximately flat reflective surface disposed between two ends, the elements arranged parallel to each other and suspended by their respective ends by integrally formed posts above a substrate by a distance;
b. deforming selected ones of the elongated elements toward the substrate by moving the approximately flat reflective surface of the selected ones toward the substrate by a grating amplitude of approximately one-fourth to one-third of the distance thereby causing the selected ones to be in a deformed state wherein the incident beam of light is diffracted; and
c. returning the selected ones of the elongated elements to an undeformed state wherein the incident beam of light is reflected.
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59. A method of modulating an incident beam of light having a wavelength, the method comprising steps of:
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a. causing the beam of light to impinge upon a plurality of elongated elements, each having an approximately flat reflective surface disposed between two ends, the elements arranged parallel to each other and suspended by their respective ends by integrally formed posts above a substrate; and
b. deforming selected ones of the elongated elements toward the substrate surface thereby causing the selected ones to be in a deformed state wherein the approximately flat reflective surface of each selected element is moved toward the substrate by a grating amplitude of a whole number or zero multiplied by one-half the wavelength of the incident beam of light plus approximately one-fourth the wavelength of the incident beam of light, without the selected elongated elements contacting a surface of the substrate.
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60. A method of forming a light modulator on a substrate, the light modulator for modulating an incident beam of light having a wavelength within a visible range of wavelengths, the method comprising steps of:
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a. forming a sacrificial layer on the substrate, wherein the sacrificial layer has a thickness that is approximately equal to the wavelength of the beam of light;
b. etching at least four post holes through the sacrificial layer;
c. forming posts in the post holes;
d. forming at least two elongated elements over the sacrificial layer, each elongated element coupled to the substrate by two of the posts one at each end of each elongated element, each elongated element having a reflective surface; and
e. removing the sacrificial layer. - View Dependent Claims (61)
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Specification