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. 12, 1993
Filed:
Jun. 09, 1989
Garrett Moddel, Boulder, CO (US);
Mark A Handschy, Boulder, CO (US);
Other;
Abstract
The present invention relates to an optically addressed spatial light modulator with high spatial resolution and a fast response. The spatial light modulator includes photoresponsive layers of amorphous silicon and light modulating layers of ferroelectric liquid crystals (FLCs). The present invention is particularly charactierized in that the problems due to large capacitances of thin layers of the amorphous silicon and FLC are overcome by preventing excessive spurious signals from being applied to the light modulating layer. This is accomplished by combining thin light modulating with thick photoresponsive layers, using asymmetric driving waveforms, using slow driving waveforms combined with conductive light modulators, and by using suitable materials constants such as high polarization or high dielectric constant FLCs. According to such arrangements, the characteristic response time of the light modulator for a reversal of an applied electric field polarity is substantially shorter than its characteristic response time caused by the removal of an applied electric field. Also, the present invention has the benefit that when the state of the electrical driver is changed from a first state to a second state so as to switch the light modulator from a first optical state to a second optical state, charges are prevented from accumulating on the light modulator so as to prevent spurious signals.