Image gating using an array of reflective elements

Patent metadata

Field	Value
Publication number	US-9835849-B2
Application number	US-201213625178-A
Country	US
Kind code	B2
Filing date	Sep 24, 2012
Priority date	Sep 26, 2011
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

A device for image gating using an array of reflective elements is provided herein. The device includes an array of reflective elements, wherein each one of the reflective elements is movable within a range of a plurality of tilt positions, wherein the array is located at an image plane of the device, wherein the array is perpendicular to an optical axis of the device. The device further includes a control unit configured to control the reflective elements such that in at least some of the tilt positions, the reflective elements reflect the radiant flux at said image plane, to one or more projection planes. A gradual rotation of the reflective elements along the plurality of tilt positions result in a gradual increase or decrease in the intensity of the image reflected from the array of reflective elements while maintaining the image integrity.

First claim

The invention claimed is:

1. A gated imaging system comprising:
a pulsed light source configured to generate a light pulse;
at least one sensor;
a main lens configured to focus a radiant flux of electromagnetic radiation from the pulsed light source entering the lens at a focal plane of the main lens;
an array of tiltable reflective elements, located at the focal plane of the main lens, wherein the tiltable reflective elements have a 1 st position and a 2 nd position, being respectively extreme tilt positions of the tiltable reflective elements; and
a control unit configured to selectively set the reflective elements, in said 1 st position and said 2 nd position, at each of which the reflective elements reflect the radiant flux focused at said focal plane, to the at least one sensor via a folding mirror other than the tiltable reflective elements,
wherein the control unit is synchronized with the pulsed light source such that the pulsed light source is activated when the tiltable reflective elements are in transition between the 1st and 2nd positions.

2. The imaging system according to claim 1 , further comprising one or more sets of field lens through which the radiant flux coming from the array of reflective elements is focused, and wherein the at least one sensor is located at a focal plane of the one or more sets of field lens.

3. The imaging system according to claim 1 , further comprising one or more folding elements configured to fold the radiant flux reflected from the reflective elements onto the at least one sensor.

4. The imaging system according to claim 3 , wherein the folding element is a beam splitter.

5. The imaging system according to claim 3 , wherein the folding element is a total internal reflection (TIR) prism.

6. The imaging system according to claim 1 , further comprising a photographic lens, wherein the array of the reflective elements is located at the focal plane of the photographic lens, and wherein the imaging system is configured to operate within an optical spectrum.

7. The imaging system according to claim 1 , wherein in one of the 1 st or 2 nd tilt positions, the reflective elements are co-planar.

Assignees

• Elbit Systems Ltd

Inventors

• Schneider Ron
• Zohar Eyal

Classifications

• G01S17/89 Primary

  for mapping or imaging · CPC title

• G01S17/18

  wherein range gates are used · CPC title

• G02B26/0833

  the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD (G02B26/0825 takes precedence; micromechanical devices in general B81B) · CPC title

• G02B26/08 Primary

  for controlling the direction of light (in light guides G02B6/35) · CPC title

• G01S7/4816

  of receivers alone · CPC title