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US 4,792,213 AGranted
Thermal imaging device
AssigneeGeneral Electric Company
InventorCyril Hilsum
Life of this patent
Estimating the term…
Abstract
A thermal imaging device uses a compensated cholesteric liquid crystal mixture as its thermo-optic conversion element. The mixture is obtained by mixing two cholesteric liquid crystals, one with a left-handed twist and the other with a right-handed twist. The twists cancel at a compensation temperature, the mixture thus having infinite twist at this temperature. The device is designed to operate with the mixture held in the region of the compensation temperature.
Claims10
A thermal imaging device, comprising:
- (a) a thermo-optic conversion element including a compensated cholesteric liquid crystal mixture of two cholesteric liquid crystals, one with a left-handed twist, and the other with a right-handed twist, said mixture having a composition such that said twists cancel at a compensation temperature, whereby said mixture has infinite pitch at said compensation temperature;
- (b) means for maintaining said compensated liquid crystal mixture substantially at said compensation temperature;
- (c) means for directing onto said compensated liquid crystal mixture thermal radiation from a field of view to be imaged, so that said thermal radiation causes changes in alignment of said compensated liquid crystal mixture;
- and
- (d) means responsive to aid alignment for producing an image of said field of view.
2 more elements
Dependencies are inferred from the claim text.