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:
Jan. 03, 1984
Filed:
Sep. 22, 1981
Vincent T Bly, Alexandria, VA (US);
The United States of America as represented by the Secretary of the Army, Washington, DC (US);
Abstract
A twisted nematic liquid crystal optical, temporal bandpass filter device for transmitting optical images only having the time response near a given frequency. The device is comprised of two linear dichroic polarizers with orthogonal polarities at the input and output of the device and two twisted nematic liquid crystal light valves and a relay lens between the light valves. Each of the two light valves has a different time response and has opposite rotary direction handedness of the twist within the nematic liquid crystal cells. That is, the liquid crystal material in the cells is homogeneously aligned with 90.degree. twist between the front and back thin alignment insulator surfaces and the cells have counter untwisting of the polarized light. An a.c. voltage is applied across each cell with proper frequencies and proper liquid crystal cell thicknesses to insure that one of the light valves has a faster time response so that only the frequencies of the optical light image within the time based modulation of the faster cell but about the passband of the slower will be transmitted out the device since the slower cell has not counter twisted and cancelled the untwisting effect of the faster cell.