Dual field of view optics with non-mechanical switching

Patent metadata

Field	Value
Publication number	US-9201220-B1
Application number	US-201414532245-A
Country	US
Kind code	B1
Filing date	Nov 4, 2014
Priority date	Nov 4, 2014
Publication date	Dec 1, 2015
Grant date	Dec 1, 2015

Abstract

An all-refractive optical system that images a scene at two different fields of view or FOVs, with switching between FOVs enabled by switchable lens elements is disclosed. The two fields of view vary in focal length by a factor of three. The wide FOV images broad-band Short Wave InfraRed SWIR radiation at an f/number of 1.7, while the narrow FOV images narrow-band illuminated SWIR at f/4.9. A voltage change across the switchable lens elements generates an optical power change between finite focus and infinite focus. Situated among static optical elements, the switching elements enable FOV changes with no mechanical movement. The given f/numbers at each FOV are a result of a fixed aperture in the system. The smaller throughput in the narrow FOV mode is augmented by narrow-band illumination of the scene to maintain equivalent sensor response between the two FOVs.

First claim

What is claimed is:

1. A compact optical imager that can switch field of view without mechanical motion, comprising:
a first electrically switchable lens capable of receiving either wide broadband or narrow spectral band rays on its front aperture;
a meniscus lens with its front aperture facing a back aperture of the electrically switchable lens;
a negative lens with its front aperture facing a back aperture of the meniscus lens;
a positive lens with its front aperture facin…

Assignees

• Us Army
• Us Navy

Inventors

• Pixton Bruce M
• Vizgaitis Jay N
• Draper Russell S

Classifications

• G02B13/009

  Physics · mapped topic

• H04N5/2254

  Electricity · mapped topic

• G02B13/0075 Primary

  Physics · mapped topic

• H04N5/23296

  Electricity · mapped topic

• G02B13/0015

  Physics · mapped topic