The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 11, 1996
Filed:
Aug. 02, 1994
Robert J Moffat, Salinas, CA (US);
Dino J Farina, Newton, MA (US);
Other;
Abstract
An apparatus and method for accurately calibrating the full-field color response to temperature of a thermochromic liquid crystal (12, 76) (TLC) located on a substrate material (10, 78). The apparatus uses a camera (50) to measure a reflected light (101) reflected by the TLC (12, 76) from a light source (54) which preferably illuminates the TLC with a full visible light spectrum (100). To achieve a temperature distribution over its surface the TLC (12, 76) is placed on a thermal element (14, 80) and allowed to reach a steady state. An optically transmissive pane (36) covers the TLC and contact assurance elements (38) which ensure contact pressure between the thermal element (14, 80) and the TLC. A set of optically transmissive plates (42, 44) mounted on top of one another and separated by air gap (46) covers the optically transmissive pane (36) and provides a thermal resistance to prevent heat leakage. The apparatus has a preferably ring-shaped light source (54) mounted above the set of optically transmissive plates (42, 44) for illuminating the TLC. For increased calibration accuracy the apparatus has an infrared filter (56) and an ultraviolet filter (58) mounted upstream from the light source (54) for removing ultraviolet and infrared radiation. Additionally, the apparatus has two polarizers (64, 66) to only admit circularly polarized light into the camera (50).