Radiant energy – Infrared-to-visible imaging – Including liquid crystal detector
Patent
1984-09-24
1986-06-10
Smith, Alfred E.
Radiant energy
Infrared-to-visible imaging
Including liquid crystal detector
250330, 250332, G02F 113
Patent
active
045945071
ABSTRACT:
A thermal imager includes an infrared sensitive light valve and a light source arranged to illuminate the full responsive area of the valve. The imager also includes an optical stage having focussing optics for forming an infrared image upon the surface of the valve and a chopper for modulating infrared radiation from a scene. Modulated light from the valve is read out in parallel by a detector array, and frame signals corresponding to alternate positions of the chopper are subtracted to provide uniformity correction. The light valve may comprise an infrared sensitive optically active liquid crystal cell and an analyzer adjusted to near extinction. An optical processor comprising a lens and an apodized stop filter lies in the light path between the valve and the detector array. The light source may comprise an array of light emitting diode elements and the filter a number of corresponding off-axis stop regions.
REFERENCES:
patent: 2824235 (1958-02-01), Hahn, Jr. et al.
patent: 3153146 (1964-10-01), Lady
patent: 4262198 (1981-04-01), Gupta et al.
B. F. Lamouroux and B. S. Prade, "Signal-to-Noise Ratio Analysis of a Digital Polarimeter Application to Thermal Imaging" Rev. Sci. Instrum. vol. 54, No. 5, (May 1983), pp. 582-585.
Y. B. Andre, J. P. Chambaret, B. L. Lamouroux and B. S. Prade, "Transient Thermal Behavior of a Liquid Crystal Target" Infrared Physics vol. 20, (1980), pp. 341-347.
Y. V. Andre, J. P. Chambaret, M. A. Franco and B. S. Prade, "Infrared Video Camera at 10 .mu.m" Applied Optics vol. 18, No. 15, (Aug. 1979), pp. 2607-2608.
Elliott Charles T.
Humphreys Richard G.
Watton Rex
Hannaher Constantine
Hinds William R.
Smith Alfred E.
The Secretary of State for Defence in Her Britannic Majesty's Go
LandOfFree
Thermal imager does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Thermal imager, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Thermal imager will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2407256