360 Degree optical surveillance system

• US 4,982,092 A
• Filed: 07/05/1973
• Issued: 01/01/1991
• Est. Priority Date: 07/05/1973
• Status: Expired due to Term

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Jehle, Robert E.
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US05/377,670
• Time in Patent Office: 6,389 Days
• Field of Search: 250/338, 250/330, 250/331, 250/332, 250/333, 250/334, 352/69, 352/70, 352/71, 178/7.3 D, 178/7.5 D, 178/7.6, 350/21, 350/22, 350/23, 350/538, 350/539, 350/540, 358/108, 358/113
• US Class Current: 250/332
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems
• CPC Class Codes: G02B 2027/0138 comprising image capture systems, e.g. camera
• CPC Class Codes: G02B 27/01 Head-up displays
• CPC Class Codes: G02B 27/642 Optical derotators, i.e. systems for compensating for image rotation, e.g. using rotating prisms, mirrors
• CPC Class Codes: G08B 13/194 using image scanning and comparing systems
• CPC Class Codes: G08B 17/12 Actuation by presence of radiation or particles, e.g. of infrared radiation or of ions
• CPC Class Codes: G09F 19/18 involving the use of optical projection means, e.g. projection of images on clouds projection apparatus per se G03B
• CPC Class Codes: H04N 3/09 for electromagnetic radiation in the invisible region, e.g. infrared

Abstract

A 360 degree surveillance system for detecting an infrared IR signal comingrom a scene. The IR signal is reflected by the scanning mirror to an imaging lens. The scanning mirror rotates 360 degrees around a vertical axis. The imaging lens images the IR signal through a derotator onto a linear array of IR detectors. The derotator serves to keep the image of the IR scene in a proper orientation. The detectors sense the IR signal and produce a current proportional to its strength. Each detector is the beginning of a channel of information. Each channel has operational amplifiers to process the signal, control gain, restore dc, etc. The output of the amplifiers are fed to a linear array of LED'"'"'s. The light output of the LED'"'"'s passes through a rotator and is imaged by a projector lens, after reflection off a rotating mirror, onto a cylindrical screen. The purpose of the rotator is to keep the image of the LED'"'"'s in the proper orientation on the screen. The purpose of the rotating projector mirror is to synchronously reflect the light from the LED'"'"'s onto the screen so that there exists a constant relationship between the image produced on the screen to that seen by the detectors through the scanning mirror.

Claims

1. A 360 degree infrared surveillance system for producing a visible display of heat producing bodies comprising:

rotating means for scanning a 360°

azimuthal plane at an angular velocity faster than the flicker fusion rate of the eye;

derotating means for projecting infrared light from said rotating means for scanning to a stationary position;

detector means disposed at said stationary position to convert said infrared light into an electrical signal;

means for emitting visible light when varies in amplitude proportionally to the amplitude of said electrical signal produced by said detector means;

means for rotating said visible light at the same angular velocity as said rotating scanner;

a rotating projection mirror;

a cylindrical screen located around said rotating projection mirror;

a cylindrical reflective surface disposed opposite said screen to reflect light from said projection mirror onto a portion of said screen.

2. The surveillance system of claim 1 wherein said detector means comprises:

more than one detector array responsive to various frequency ranges of infrared light;

means for selectively connecting one or any number of said arrays to said means for emitting visible light.

3. The device of claim 2 wherein each said array has separate optical means for scanning and derotating said infrared light.

4. A 360 degree infrared surveillance system for producing a visible display of heat producing bodies comprising:

rotating means for scanning a 360°

azimuthal plane at an angular velocity faster than the flicker fusion rate of the eye;

derotating means for projecting infrared light from said rotating means for scanning to the stationary position;

detector means disposed at said stationary position to convert said infrared light into an electrical signal;

means for emitting visible light which varies in amplitude proportionally to the amplitude of said electrical signal produced by said detector means;

means for rotating said visible light at the same angular velocity as said rotating scanner;

rotating projection means for deflecting said visible light;

at least one television camera disposed to scan said deflected visible light;

at least one television monitor for displaying said scanned light.

5. The surveillance system of claim 4 further comprising:

means for superimposing the picture produced by at least one of said television monitors on the screen as viewed by an observer.