Optical: systems and elements – Holographic system or element – Using a hologram as an optical element
Patent
1990-10-23
1992-10-20
Miller, Stanley D.
Optical: systems and elements
Holographic system or element
Using a hologram as an optical element
359 48, 359 85, 359 86, 340784, 340793, G02F 1133
Patent
active
051575256
ABSTRACT:
The contrast or absolute brightness of a multiplexed LCD is maintained at its preselected value using a feedback arrangement which includes an LCD element functioning as a reference element. The reference element is not used to display information but is continually driven ON and OFF. The average transmissivity of the ON and OFF states is determined and compared with a reference value, the result of the comparison being used to control the voltage levels of the drive waveforms applied to the LCD. By selecting appropriate ratios between the ON and OFF times of the reference element, the LCD can be operated to give optimum contrast, or may have its absolute brightness varied. Control may be effected remotely by reprogramming the microprocessor which determines the timing of the drive waveforms.
REFERENCES:
patent: 3705310 (1972-12-01), Wild
patent: 3770961 (1973-11-01), Westell
patent: 4119842 (1978-10-01), Hayden et al.
patent: 4278325 (1981-07-01), Kondo et al.
patent: 4603946 (1986-08-01), Kato et al.
patent: 4690508 (1987-09-01), Jacob
patent: 4738514 (1988-04-01), Stewart
patent: 4760389 (1988-07-01), Aoki et al.
patent: 4825201 (1989-04-01), Watanabe et al.
patent: 4848877 (1989-07-01), Miller
patent: 4919520 (1990-04-01), Okada et al.
patent: 4920257 (1990-04-01), Fuerthbauer et al.
patent: 4962376 (1990-10-01), Inoue et al.
Kahn et al.-"Temperature Dependence of Multiplexed TN-Liquid Crystal Displays" Non-Emissive Electro-optic Display-Plenum Press-New York-1976 pp. 289-297.
Dickson et al., "Control Circuit For Liquid Crystal Cells" IBM Technical Disclosure Bulletin-vol. 13, No. 11, Apr. 1971, p. 3517.
Eaton Timothy J.
Pittock Roger J.
Duong Tai V.
EEV Limited
Miller Stanley D.
LandOfFree
Control of liquid crystal display visual properties to compensat does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Control of liquid crystal display visual properties to compensat, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Control of liquid crystal display visual properties to compensat will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-197143