PROJECTILE GUIDANCE SYSTEM INCLUDING A COMPACT SEMI-ACTIVE LASER SEEKER WITH IMMERSED FILTER STACK AND FIELD LENS
First Claim
1. A guidance system, comprising:
- a non-imaging optical system to focus incident electro-magnetic radiation (EMR) in a detection band including at least one wavelength in a range of 0.35 microns to 15 microns, comprising;
a first optical element having a first side and a second side, wherein the first side is a first lens element configured to focus incident EMR;
a spreader configured to spatially homogenize EMR transmitted through the optical system;
a filter configured to reject EMR including wavelengths outside the detection band; and
a second optical element having a first side and a second side, wherein the second side is a second lens element configured to control the aberration characteristics of the EMR transmitted through the optical system;
said first optical element, spreader, filter and second optical element optically bonded together in an integrated filter stack having only a first air-to-glass interface at the first side of the first optical element and a second air-to-glass interface at the second side of the second optical element, andan irradiance detector coupled to the optical system and configured to generate at least one guidance signal in response to the spatial displacement of the centroid of the focused incident EMR in the detection band.
1 Assignment
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Accused Products
Abstract
A compact SAL seeker for a projectile guidance system comprises an optical sub-assembly to focus incident electro-magnetic radiation (EMR) such that target bearing in object space is mapped to a spatial irradiance in image space and a detector sub-assembly to generate at least one guidance signal in response to the position of the centroid of the focused EMR. The optical sub-assembly includes an integrated filter stack of a primary optical element, a spreader, a filter and secondary optical element in which at least one and typically both of the spreader and filter are immersed within the optical media of the stack. The detector sub-assembly may include a field lens in which the detector is immersed. Immersion reduces the number of “air-to-glass” interfaces, hence improves optical throughput. The detector sub-assembly may be integrally formed with a mounting bracket adapted to mate with mounting features on the optical sub-assembly to provide a self-aligned seeker.
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Citations
23 Claims
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1. A guidance system, comprising:
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a non-imaging optical system to focus incident electro-magnetic radiation (EMR) in a detection band including at least one wavelength in a range of 0.35 microns to 15 microns, comprising; a first optical element having a first side and a second side, wherein the first side is a first lens element configured to focus incident EMR; a spreader configured to spatially homogenize EMR transmitted through the optical system; a filter configured to reject EMR including wavelengths outside the detection band; and a second optical element having a first side and a second side, wherein the second side is a second lens element configured to control the aberration characteristics of the EMR transmitted through the optical system; said first optical element, spreader, filter and second optical element optically bonded together in an integrated filter stack having only a first air-to-glass interface at the first side of the first optical element and a second air-to-glass interface at the second side of the second optical element, and an irradiance detector coupled to the optical system and configured to generate at least one guidance signal in response to the spatial displacement of the centroid of the focused incident EMR in the detection band. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A guidance system, comprising:
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a non-imaging optical system to focus incident electro-magnetic radiation (EMR) in a detection band including at least one wavelength in a range of 0.35 microns to 15 microns, comprising; a first optical element having a first side and a second side, wherein the first side is a first lens element configured to focus incident EMR and the second side is generally planar; a filter including a generally planar substrate having a first side that comprises a diffuser coating to spatially homogenize EMR transmitted through the optical system and a second side that comprises a filter coating to reject EMR including wavelengths outside the detection band; and a second optical element having a first side and a second side, wherein the first side is generally planar and second side is a second lens element configured to control the aberration characteristics of the EMR transmitted through the optical system, said first optical element, filter and second optical element optically bonded together in an integrated filter stack having only a first air-to-glass interface at the first side of the first optical element and a second air-to-glass interface at the second side of the second optical element; and a detector assembly, comprising; a third optical element having a first side and a second side, wherein the first side is a field lens element and the second side is generally planar; and an irradiance detector mounted on the generally planar second side of said third optical element facing the integrated filter stack and configured to generate at least one guidance signal in response to the spatial displacement of the centroid of the focused incident EMR in the detection band.
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17. A guidance system, comprising:
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a non-imaging optical system to focus incident electro-magnetic radiation (EMR) in a detection band including at least one wavelength in a range of 0.35 microns to 15 microns, comprising; a first optical element having a first side and a second side, wherein the first side is a first lens element configured to focus incident EMR and the second side is generally planar; an array of rectangular-shaped lenslets to spatially homogenize EMR transmitted through the optical system; a filter to reject EMR including wavelengths outside the detection band; and a second optical element having a first side and a second side, wherein second side is a second lens element configured to control the aberration characteristics of the EMR transmitted through the optical system, said first optical element, array of rectangularly-shaped lenslets, filter and second optical element optically bonded together in an integrated filter stack having only a first air-to-glass interface at the first side of the first optical element and a second air-to-glass interface at the second side of the second optical element; and a detector assembly, comprising; a third optical element having a first side and a second side, wherein the first side is a field lens element and the second side is generally planar; and a irradiance detector mounted on the generally planar second side of said third optical element facing the integrated filter stack and configured to generate at least one guidance signal in response to the spatial displacement of the rectangularly-shaped centroid of the focused incident EMR in the detection band. - View Dependent Claims (18)
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19. A guidance system, comprising:
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an optical sub-assembly to focus incident electro-magnetic radiation (EMR) in a detection band including at least one wavelength in a range of 0.35 microns to 15 microns, comprising; a first optical element having a first side and a second side, wherein the first side is a first lens element configured to focus incident EMR; a spreader configured to spatially homogenize EMR transmitted through the optical system; a filter configured to reject EMR including wavelengths outside the detection band; and a second optical element having a first side and a second side, wherein the second side is a second lens element configured to control the aberration characteristics of the EMR transmitted through the optical system, said second lens element formed with mounting features; said first optical element, spreader, filter and second optical element optically bonded together in an integrated filter stack having only a first air-to-glass interface at the first side of the first optical element and a second air-to-glass interface at the second side of the second optical element; and a detector sub-assembly comprising; a third optical element having a first side and a second side, wherein the first side is a field lens element; a mounting bracket integrally formed with said third optical element and mated with the mounting features formed in said second lens element; and an irradiance detector coupled to the optical system and configured to generate at least one guidance signal in response to the spatial displacement of the centroid of the focused incident EMR in the detection band. - View Dependent Claims (20, 21, 22, 23)
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Specification