US 4,544,844 AGranted

Image tube IR illuminator indicator

AssigneeThe United States of America as represented by the Secretary of the Army

InventorThomas E. Moyers

Life of this patent

Estimating the term…

Loading patent…

Abstract

An infrared (IR) illuminator indicator which has a fiber optics light guide hat channels the IR radiation from an IR radiation source in the illuminator to the faceplate of an image tube as an indicator mark. The image tube converts the IR radiation to the visible spectrum. If the operator of the image tube attempts to operate the IR illuminator at large ranges, or if a near target is suddenly removed so that the IR radiation suddenly reached a much larger range, the image tube gain will suddenly increase to compensate for less reflected radiation. With the fiber optics light guide channeling a constant amount of IR radiation from the IR radiation source to the input of the faceplate, the enhanced gain of the image tube automatically brightens the indicator mark to the observer of the image tube and thus indicates the need to immediately turn off the IR radiation source to avoid detection by the enemy.

Claims6

Dependent claims

An IR illuminator indicator in an IR to visible imaging system, said indicator comprising:

an IR radiation source in an IR illuminator;
an image tube having switchable means for switching said IR radiation source on and off;
and
a fiber optics guide means having an input end and an output end respectively connected between the proximity of said IR radiation source and an input faceplate of said image tube for directly channeling a small portion of the IR radiation from said IR radiation source to an indicator mark on said input faceplate in which said IR radiation source simultaneously emits IR radiation straight forward toward a target and into said input end of said fiber optics guide means wherein reflected IR radiation from said target and from said indicator mark is detected by an observer viewing said image tube in which any sudden gain of said image tube caused by an operator of the image tube changing from viewing a near view highly reflective target to a less reflective distant target area enhances the brightness of said indicator mark when compared with said reflected IR radiation being observed and said IR radiation source may be turned off to prevent possible enemy detection in said distant target area.

1 more element

Dependencies are inferred from the claim text.