Color video display system comprising electrostatically deflectable light valves

• US 3,896,338 A
• Filed: 11/01/1973
• Issued: 07/22/1975
• Est. Priority Date: 11/01/1973
• Status: Expired due to Term

• Current Assignee: Harvey C. Nathanson, Jens Guldberg
• Original Assignee: Harvey C. Nathanson, Jens Guldberg
• Inventors: Nathanson, Harvey C., Guldberg, Jens
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Potenza, J. M.
• Application Number:
  US05/411,885
• Time in Patent Office: 628 Days
• Field of Search: 315/21R,373 313/91 178/7.5D,5.4BD
• US Class Current: 315/373
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
• CPC Class Codes: H01J 29/12 acting as light valves by shutter operation, e.g. for eidophor
• CPC Class Codes: H01J 31/24 with screen acting as light valve by shutter operation, e.g. eidophor projection arrangements for image reproduction, e.g. using eidophor H04N5/74
• CPC Class Codes: H04N 9/3114 by using a sequential colour filter producing one colour at a time

Abstract

A color video imaging system utilizing a cathode ray device with a target comprising an array of electrostatically deflectable light valves. The light valve structure and the arrangement of light valves as an array permits sequential activation of the light valves in response to a specific primary color video signal. The light valves are arranged in three element groupings, and a schlieren optical means is provided having respective primary color transmissive portions through which the light reflected from the deflected light valves is passed, to permit projection of a color image upon a display screen.

Claims

1. A video imaging system comprising:

a. a cathode ray tube including at least one electron gun;

b. an electrostatically deflectable light valve array target comprising a light transmissive substrate, a plurality of groupings of three spaced apart generally planar light reflective elements individually supported by a spacer-post member extending from the substrate, the spacer-post member being of substantially less cross-section than the light reflective element, and being located entirely beneath the light reflective element, and a light transmissive potential electrode disposed upon the substrate in the space between reflective elements, with respective reflective elements of each grouping of three being deflectable along three respective symmetrically offset primary color axes of deflection in response to a specific primary color video signal;

c. optical means and a light source for directing light onto the respective reflective elements and including selective transmissive portions of the optical means for passing light of a specific primary color from the deformed reflective element to permit focusing of a color image upon a screen, which selective transmissive portions are symmetrically spaced about the central optical axis of the optical means in correspondence to the respective primary color axes of deflection;

d. means for scanning the electron beam from the electron gun and for synchronizing and modulating a video signal to permit sequential activation of respective primary color designated reflective elements.

2. The system set forth in claim 1, wherein each grouping of three reflective elements comprise three approximately 120* triangular elements disposed about a common central apex, and the optical means selective transmissive portions comprise conversely disposed 120* transmissive portions about an opaque central stop.

3. The system set forth in claim 2, wherein the video signal is sequentially applied to the reflective elements.

4. The system set forth in claim 1, wherein the grouping of reflective elements comprise reflective elements which are deflectable about three specific axes each approximately 120* offset, which correspond to specific primary colors, with reflective elements which bend in the same direction being arranged in rows, and the optical means transmissive portions about a central stop being about the same three specific axes.

5. The system set forth in claim 4, wherein the video signal is sequentially applied to rows or columns of reflective elements.

6. The system set forth in claim 1, wherein the grouping of light reflective elements corresponding to three primary colors comprise three respective rows or columns of light reflective elements, with the rows or columns corresponding to A specific primary color being deflectable about a first axis, and the other two rows or columns of light valves being deflectable aobut axes which are respectively offset by about 60 degrees from the first axis and the other axis.

7. The system set forth in claim 6, wherein the optical means selective transmissive portions comprise pairs of triangular panels for each primary color disposed about an opaque central stop, with each pair of selective transmissive panels respectively disposed about the same axis about thich the light reflective elements are deflectable about.

8. An electrostatically deflectable light valve structure which is disposed upon a light transmissive substrate and is readily usable for color video imaging comprising:

three spaced apart symmetrical elements disposed about a central axis, each of said elements comprising a generally planar approximately 120* triangular electrostatically deflectable, light reflective portion disposed generally parallel to the substrate, a support and spacer-post extending from the underside of the deflectable planar portion to a light transmissive substrate, said support and spacer post is of substantially less cross-section than the deflectable planar portion, with the respective posts of the three elements proximate the central axis, with each of the deflectable planar portions being deflectable along three respective 120* offset primary color axes of deflection.

9. The device specified in claim 8, wherein an conductive grid is disposed upon the substrate proximate the perimeter portions of said planar portions whereby an electrostatic field provided between the grid and the planar portion produces deflection of the planar portion.

10. The device specified in claim 8, wherein a plurality of such three element devices are disposed as an array upon the substrate to form the imaging target of a display device.

11. The structure set forth in claim 8, wherein the light reflective planar portions comprise a deflectable support layer with a layer of light reflective material deposited thereon on the side opposite from the support and spacer post.