Image intensifier with time programmed variable gain

• US 4,603,250 A
• Filed: 08/24/1984
• Issued: 07/29/1986
• Est. Priority Date: 08/24/1984
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Army (Government of the United States of America)
• Original Assignee: The United States Of America As Represented By The Secretary Of The Army
• Inventors: Basta, Robert J., Carsten, Terry E., Contini, Daniel A.
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Messinger, Michael
• Application Number:
  US06/644,165
• Time in Patent Office: 704 Days
• Field of Search: 250/213 VT, 250/214 AG, 356/5, 313/103 CM, 313/105 CM
• US Class Current: 250/214.0VT
• CPC Class Codes: G01S 7/4816 of receivers alone
• CPC Class Codes: G01S 7/4912 Receivers
• CPC Class Codes: H01J 2231/50015 Light
• CPC Class Codes: H01J 2231/50084 using light or electron beam scanning
• CPC Class Codes: H01J 2231/5016 Michrochannel plates [MCP]
• CPC Class Codes: H01J 31/28 with electron ray scanning the image screen
• CPC Class Codes: H01J 31/50 Image-conversion or image-amplification tubes, i.e. having optical, X-ray, or analogous input, and optical output

Abstract

A programmable optical sensor is formed by coupling a proximity focused channel intensifier tube to a silicon target vidicon. The photocathode is gated by a first time programmed voltage and the gain of the microchannel plate is also controlled by a second time programmed voltage. The second voltage is less than 1,000 volts permitting the use of solid state circuitry.

Claims

1. A programmable optical sensor comprising:

a proximity focused channel intensifer tube; and

a silicon target vidicon optically coupled to said proximity focused channel intensifer tube but electrically isolated therefrom, said proximity focused channel intensifer tube including an image receiving photocathode, and adjacent microchannel plate having first and second electrodes on opposite sides thereof, and a phosphor screen;

a first source of direct voltage applying a time programmed variable gating voltage to said photocathode;

a second source of direct voltage applying a time programmed variable voltage across said opposite electrodes of said michrochannel plate and being independent of and programmed separately from said first source;

a third source of direct voltage applying a fixed voltage to said phosphor screen;

optical coupling means between said channel intensifer tube and silcicon target vidicon including a first fiber optic stage in said proximity focused channel intensifer tube adjacent said phosphor screen, and a second fiber optic stage in said silicon target vidicon adjacent said first fiber optic stage.

2. The programmable optical sensor in accordance with claim 1 wherein:

said first time programmed voltage source never exceeds 200 volts forward voltage; and

said second time programmed voltage source never exceeds 1,000 volts forward voltage.

3. The programmable optical sensor in accordance with claim 1 including a grounded NESA conductive coat between said first and second fiber optic stages providing electrical isolation between said silicon target vidicon and channel intensifier tube.

4. The device of claim 1 wherein said first time programmed voltage source applies a first voltage of from 0 to 100 volts to said photocathode, said second time programmed voltage source applies a second voltage across said electrodes of said microchannel plate of from 0 to 800 volts at a given time after said first voltage, said third voltage source applies a fixed bias voltage of from 3,000 to 5000 volts DC to said phosphor screen, said first and second voltages being terminated after from 20 to 100 microseconds.

5. The device of claim 4 wherein said second electrode of said microchannel plate is connected to ground.