Electrostatically deflectable light valve with improved diffraction properties

• US 3,886,310 A
• Filed: 08/22/1973
• Issued: 05/27/1975
• Est. Priority Date: 08/22/1973
• Status: Expired due to Term

• Current Assignee: Harvey C. Nathanson, Jens Guldberg
• Original Assignee: Harvey C. Nathanson, Jens Guldberg
• Inventors: Guldberg, Jens, Nathanson, Harvey C.
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Montone, G. E.
• Application Number:
  US05/390,470
• Time in Patent Office: 643 Days
• Field of Search: 315/21R 313/91,465 178/7.5D,5.4BD 350/161
• US Class Current: 348/771
• CPC Class Codes: G02B 26/0841 the reflecting element being moved or deformed by electrostatic means
• CPC Class Codes: G09F 9/372 the positions of the elements being controlled by the application of an electric field
• CPC Class Codes: H01J 29/12 acting as light valves by shutter operation, e.g. for eidophor
• CPC Class Codes: H04N 5/7425 the modulator being a dielectric deformable layer controlled by an electron beam, e.g. eidophor projector

Abstract

An electrostatically deflectable light valve adapted for use in an array for producing television pictures as a projected image upon a large display screen. The light valve structure is such that a plurality of reflective wing portions are free to be deflected along directional axes which are at an angle to the prime directional axes of the overall array, so that light which is predominantly diffracted along the array axes may be decoupled or separated from the signal light produced by activated light valves and used to project the image. The contrast ratio of signal light to background light for the system is significantly improved, using this method of discrimination.

Claims

1. An electrostatically deflectable light valve system comprising an array of spaced apart, deformable, light reflective elements supported upon a substrate, each of said reflective elements comprising a central core portion supported by a centrally located post member which extends from one side of the reflective elements to the supporting substrate, a plurality of generally planar, symmetrically spaced apart and shaped independently deformable and reflective wing portions extending outwardly from the central core portion, which wing portions are defined by an equal plurality of thin slits provided between said wing portions which slits extend from the central core portion to the outer edge of the wing portions.

2. The system specified in claim 1, wherein an electrode grid is disposed upon the supporting substrate.

3. The system specified in claim 1, wherein the substrate is a light transmissive material.

4. The system specified in claim 1 wherein four generally square wing portions are provided with thin slits separating the wing portions.

5. The system specifified in claim 4, wherein the slits are aligned with the axes of the array pattern in which the light valves are arranged.

6. The system specified in claim 5 when the planar portion of the light valve is substantially square and the slits extend from the edges of each wing to the central core portion.

7. The system specified in claim 1, wherein a light reflective coating is provided on the top surface of the central core portion and the wing portions.

8. The system specified in claim 3, in combination with a light source, an optical system for directing light through the transmissive substrate to the surface of the reflective light valves, said optical system including an opaque stop disposed in the optical path between the array of light valves and a display screen, so that when the wing portions of the light valves are nondeflected the light reflected is substantially totally reflected off or blocked by the stop and no light reaches the display screen, while when the wing portions are deflected a portion of the light reflected therefrom passes around the central stop and produces a large, displayed image.

9. A light reflective element adapted for use as an electrostatically deflectable light valve which element comprises;

a central core portion supported by a post member which extends from one side of the core portion, and a plurality of generally planar, symmetrically spaced and shaped independently deformable reflective wing portions extending outwardly from the central core portion, which wing portions are defined by an equal plurality of thin slits provided between said wing portions which slits extend from the central core portion to the outer edge of the wing portions.

10. The light reflective element specified in claim 9, with four generally square wing portions provided, with thin slits separating the wing portions.

11. An electrostatically deflectable light valve system comprising an array of spaced apart, deformable light reflective elements supported upon a substrate, the elements being arrayed along X and Y orthogonal axes, each of said reflective elements comprising a central core portion supported by a centrally located post member which extends from one side of the reflective elements to the supporting substrate, and four spaced apart, generally planar, symmetrically spaced and shaped deformable and reflective wing portions extending outwardly from a common central core portion, which four wing portions are spaced apart by slits extending in the direction of the X and Y axes of the array pattern.