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US 6,151,170 AGranted
Dual purpose infrared lens assembly using diffractive optics
AssigneeRaytheon Company
InventorRobert B. Chipper
Life of this patent
Estimating the term…
Abstract
An infrared zoom lens assembly (16) operative as either a continuous zoom or a two-position zoom lens. The infrared zoom lens assembly (16) includes a focusing component (33), a collecting component (37) and a diffracting component (41). The focusing component (33) includes a first focusing zoom lens (34) positioned at the same location at the ends of the zoom range and a second focusing zoom lens (36) movably mounted in the infrared zoom lens assembly (16). The diffracting component (41) may be used to correct color aberrations associated with an infrared waveband. The focusing component (33) and the collecting component (37) cooperate with the diffracting component (41) to focus infrared radiation at an image plane (15) of an infrared detector (18).
Claims27
An apparatus comprising:
- an infrared zoom lens assembly having a first zoom state in which said zoom lens assembly effects a first degree of magnification with respect to infrared radiation passing therethrough, and having a second zoom state in which said zoom lens assembly effects a second degree of magnification with respect to infrared radiation passing therethrough, the second degree being different from the first degree, said zoom lens assembly including a first zoom lens which is disposed at a first position along an optical axis when said zoom lens assembly is in each of the first and second zoom states, and including a second zoom lens which is supported for movement along the optical axis, said second zoom lens being disposed in second and third positions along the optical axis when said zoom lens assembly is respectively in the first and second zoom states, the third position being spaced from the second position, said second zoom lens moving away from said first zoom lens when moving from the second position to the third position, and said first and second zoom lenses being optically configured so that, if said first zoom lens moved along the optical axis away from the first position toward said second zoom lens and then back to the first position as said second zoom lens moved from the second position to the third position, said first and second zoom lenses would cooperate optically to provide a continuous zoom from the first zoom state to the second zoom state.
An apparatus comprising:
- an infrared zoom lens assembly having a first zoom state in which said zoom lens assembly effects a first degree of magnification with respect to infrared radiation passing therethrough, and having a second zoom state in which said zoom lens assembly effects a second degree of magnification with respect to infrared radiation passing therethrough, the second degree being different from the first degree, said zoom lens assembly including a first zoom lens which is disposed at a first position along an optical axis when said zoom lens assembly is in each of the first and second zoom states, and including a second zoom lens which is supported for movement along the optical axis, said second zoom lens being disposed in second and third positions along the optical axis when said zoom lens assembly is respectively in the first and second zoom states, the third position being spaced from the second position, and said second zoom lens moving away from said first zoom lens when moving from the second position to the third position;
- wherein as said second zoom lens moves from the second position to the third position, said first zoom lens moves away from the first position in a first direction toward said second zoom lens and then moves back to the first position in a second direction opposite the first direction.
An apparatus comprising:
- an infrared zoom lens assembly having a first zoom state in which said zoom lens assembly effects a first degree of magnification with respect to infrared radiation passing therethrough, and having a second zoom state in which said zoom lens assembly effects a second degree of magnification with respect to infrared radiation passing therethrough, the second degree being different from the first degree, said zoom lens assembly including a first zoom lens which is disposed at a first position along an optical axis when said zoom lens assembly is in each of the first and second zoom states, and including a second zoom lens which is supported for movement along the optical axis, said second zoom lens being disposed in second and third positions along the optical axis when said zoom lens assembly is respectively in the first and second zoom states, the third position being spaced from the second position, and said second zoom lens moving away from said first zoom lens when moving from the second position to the third position;
- including diffraction means provided on said second zoom lens for effecting color correction of infrared radiation passing through said zoom lens assembly, said diffraction means moving with said second zoom lens;
- and wherein said first zoom lens is disposed on an object side of second zoom lens, said first zoom lens being a negative diverging lens and said second zoom lens being a positive converging lens.
Dependencies are inferred from the claim text.