High spatial resolution 2-D bistable light modulator

• US 4,851,659 A
• Filed: 02/17/1987
• Issued: 07/25/1989
• Est. Priority Date: 02/17/1987
• Status: Expired due to Term

• Current Assignee: Optron Systems Incorporated
• Original Assignee: Optron Systems Incorporated
• Inventors: Dillon, Robert F., Warde, Cardinal
• Primary Examiner(s): Nelms, David C.
• Assistant Examiner(s): Allen, Stephone B.
• Application Number:
  US07/015,055
• Time in Patent Office: 889 Days
• Field of Search: 250/213 VT, 250/213 R, 313/103 CM, 313/105 CM, 313/334
• US Class Current: 250/214.0VT
• 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

Abstract

In one voltage-driven embodiment, a high spatial resolution two-dimensional array of bistable completely cross-talk free light modulation elements is constituted as a lamination of an input two-dimensional photoconductor thin film layer and an output two-dimensional electroluminescent phosphor thin film layer disposed in etched wells individually defined in corresponding cores of the optical fibers of a fiber optic face plate. In another voltage-driven embodiment, a very low cost high spatial resolution 2-D array of bistable substantially cross-talk free light modulation elements is constituted as a lamination of a photoconductor thin film layer, a selectively dimensioned and apertured opaque masking thin film layer, and an electroluminescent phosphor thin film layer. In an electron-driven embodiment, a high spatial resolution two-dimensional array of substantially cross-talk free bistable light modulating elements is constituted as an assembly of a two-dimensional input window having a deposited photocathode thin film layer, a two-dimensional output window having a deposited cathodoluminescent phosphor, and a two-dimensional glass capillary array defining plural charge feed forward and light feedback channels mounted therebetween in a vacuum tight enclosure. In a further electron driven embodiment, a microchannel plate subassembly is mounted in the vacuum-tight enclosure in the place of the glass capillary array. In the several embodiments, voltages are applied via transparent conductors to the photoconductor and phosphor layers.

Claims

1. A substantially cross-talk free electron-driven high spatial resolution 2-dimensional bistable light modulator, comprising:

vacuum housing means defining spaced and confronting two-dimensional input and output ports providing an evacuated region between the input and output ports;

a two-dimensional photocathode layer mounted to the two-dimensional input port;

a two-dimensional cathodoluminescent phosphor layer mounted at the two-dimensional output port;

high spatial resolution means for providing a two-dimensional array of plural elongated mutually optically and electrically isolated charge feedforward and light feedback channels in said evacuated region intermediate said two-dimensional input and output ports of said vacuum housing means in such a way that the elongated channels define straight line paths intermediate said two-dimensional photocathode and phosphor layers; and

means coupled to said photocathode layer and said cathodoluminescent phosphor layer for transferring charge from the two-dimensional photocathode layer through the high spatial resolution means in said evacuated region and for imaging the charge transferred therethrough onto the two-dimensioal phosphor layer.

2. The light modulator of claim 1, wherein said high spatial resolution means includes a glass capillary array.

3. The light modulator of claim 1, wherein said charge transfer and imaging means includes transparent planar conductors respectively adhered to said photoconductor and said phosphor layers, and a voltage source for providing a proximity-focusing and longitudinally extending E-field in the evacuated region.

4. The light modulator of claim 3, wherein said voltage source is a DC source.

5. The light modulator of claim 3, wherein said voltage source is a slowly varying AC source.

6. An ultra-high input sensitivity electron-driven high spatial resolution two-dimensional bistable light modulator, comprising:

vacuum housing means defining spaced and confronting two-dimensional input and output ports and providing an evacuated region between the input and output ports;

a two-dimensional photocathode layer mounted at the two-dimensional input port;

a two-dimensional cathodoluminescent phosphor layer mounted at the two-dimensional output port;

means for providing a two-dimensional high spatial resolution array of high-efficiency, secondary electron emitting dynodes that each define an electron amplification feedforward and a light feedback channel and that together are substantially cross-talk free; and

means coupled to said photocathode layer and to said phosphor layer and cooperative with said dynode array providing means for transferring charge from the photocathode through the evacuated region and imaging it on the phosphor layer.

7. The light modulator of claim 6, wherein the dynode array providing means includes a microchannel plate subassembly.

8. The light modulator of claim 6, wherein said charge transfer and imaging means includes transparent planar conductors mounted to the photocathode layer and to the phosphor layer respectively for providing a longitudinally-extending proximity-focusing E-field in the evacuated region.

9. The light modulator of claim 8 wherein said voltage source includes a DC voltage source.

10. The light modulator of claim 8, wherein said voltage source includes a slowly varying AC voltage source.