Dual-image optoelectronic imaging apparatus including birefringent prism arrangement
First Claim
1. An optical imaging apparatus for producing first and second optical images of a scene including first and second electromagnetic radiation having first and second orthogonal polarizations respectively received from the scene, comprising:
- a birefringent prism which refracts the first radiation therethrough in a first direction and refracts the second radiation therethrough in a second direction which is deviated from the first direction by a predetermined angle; and
optical means for focussing the first and second radiation at a focal plane to produce the first and second optical images respectively;
said predetermined angle being selected such that the first and second optical images are laterally displaced from each other by a predetermined distance in the focal plane.
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Accused Products
Abstract
A birefringent prism (36) is disposed in front of the entrance aperture (26a) of a Cassegrain-type telescope (26) which constitutes the optical focussing assembly in a tracking system for a guided missile (10) or the like. The prism (36) refracts first radiation (O) having a first polarization in a first direction, and refracts second radiation (E) having a second polarization which is orthogonal to the first polarization in a second direction which is deviated from the first direction by a predetermined angle Δφ. The telescope (26) focusses the first and second radiation (O,E) to form separate, laterally displaced first and second optical images (46,50) on first and second respective sections (34a,34b) of a focal plane photodetector array (34). Polarizing filters (56,58) which pass only the first and second polarizations therethrough are disposed in front of the respective sections (34a,34b) of the photodetector array (34) to eliminate optical crosstalk between the two images (46,50). Optical bandpass filters (54,52) having different wavelength passbands may also be provided in front of the two sections (34a,34b) of the photodetector array (34) such that the two images (46,50) constitute different color images of the scene (16).
32 Citations
36 Claims
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1. An optical imaging apparatus for producing first and second optical images of a scene including first and second electromagnetic radiation having first and second orthogonal polarizations respectively received from the scene, comprising:
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a birefringent prism which refracts the first radiation therethrough in a first direction and refracts the second radiation therethrough in a second direction which is deviated from the first direction by a predetermined angle; and optical means for focussing the first and second radiation at a focal plane to produce the first and second optical images respectively; said predetermined angle being selected such that the first and second optical images are laterally displaced from each other by a predetermined distance in the focal plane. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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19. In a guided missile, a tracking system including an optical imaging apparatus for producing first and second optical images of a scene including first and second electromagnetic radiation having first and second orthogonal polarizations respectively received from the target, comprising:
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a birefringent prism which refracts the first radiation therethrough in a first direction and refracts the second radiation therethrough in a second direction which is deviated from the first direction by a predetermined angle; and optical means for focussing the first and second radiation at a focal plane to produce the first and second optical images respectively; said predetermined angle being selected such that the first and second optical images are laterally displaced from each other by a predetermined distance in the focal plane. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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Specification