Projection display
First Claim
1. A projection display, comprising:
- a light source for providing an incident light beam to an array of micromirrors;
an array of micromirrors, each micromirror having a shape defined by a plurality of micromirror sides;
wherein the array of micromirrors has four sides and wherein there are no micromirror sides of the micromirrors in the array of micromirrors parallel to any sides of the array of micromirrors;
wherein the micromirrors are capable of movement between an OFF state and an ON state and wherein the micromirrors correspond to pixels in a viewed image;
wherein the micromirrors comprise micromirror plates that are connected via hinges to a substrate, and wherein the substrate, micromirror plates and hinges are disposed in different planes;
wherein a first gap is defined between the substrate and the hinge and a second gap is defined between the hinge and the micromirror plate;
wherein no micromirror sides are parallel to the incident light beam incident thereto when viewed from above the array;
wherein the incident light beam is incident substantially perpendicularly to a side of the array;
and wherein the incident light beam is substantially perpendicular to an axis of rotation of the micromirror.
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Accused Products
Abstract
In order to minimize light diffraction along the direction of switching and more particularly light diffraction into the acceptance cone of the collection optics, in the present invention, micromirrors are provided which are not rectangular. Also, in order to minimize the cost of the illumination optics and the size of the display unit of the present invention, the light source is placed orthogonal to the rows (or columns) of the array, and/or the light source is placed orthogonal to a side of the frame defining the active area of the array. The incident light beam, though orthogonal to the sides of the active area, is not however, orthogonal to any substantial portion of sides of the individual micromirrors in the array. Orthogonal sides cause incident light to diffract along the direction of micromirror switching, and result in light ‘leakage’ into the ‘on’ state even if the micromirror is in the ‘off’ state. This light diffraction decreases the contrast ratio of the micromirror. The micromirrors of the present invention result in an improved contrast ratio, and the arrangement of the light source to micromirror array in the present invention results in a more compact system. Another feature of the invention is the ability of the micromirrors to pivot in opposite direction to on and off positions (the on position directing light to collection optics), where the movement to the on position is greater than movement to the off position. A further feature of the invention is a package for the micromirror array, the package having a window that is not parallel to the substrate upon which the micromirrors are formed. One example of the invention includes all the above features.
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Citations
25 Claims
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1. A projection display, comprising:
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a light source for providing an incident light beam to an array of micromirrors; an array of micromirrors, each micromirror having a shape defined by a plurality of micromirror sides; wherein the array of micromirrors has four sides and wherein there are no micromirror sides of the micromirrors in the array of micromirrors parallel to any sides of the array of micromirrors; wherein the micromirrors are capable of movement between an OFF state and an ON state and wherein the micromirrors correspond to pixels in a viewed image; wherein the micromirrors comprise micromirror plates that are connected via hinges to a substrate, and wherein the substrate, micromirror plates and hinges are disposed in different planes; wherein a first gap is defined between the substrate and the hinge and a second gap is defined between the hinge and the micromirror plate; wherein no micromirror sides are parallel to the incident light beam incident thereto when viewed from above the array; wherein the incident light beam is incident substantially perpendicularly to a side of the array; and wherein the incident light beam is substantially perpendicular to an axis of rotation of the micromirror. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25)
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Specification