Photocopying – Contact printing – Light boxes
Patent
1987-12-16
1989-03-07
Miller, Stanley D.
Photocopying
Contact printing
Light boxes
350331R, 350336, 355 71, G02F 1/331, G03B 2122
Patent
active
048100625
ABSTRACT:
A high-speed responsive liquid crystal optical device with improved light transmissivity is provided. The device includes a liquid crystal panel including an optically active liquid crystal material having dielectric anisotropy which becomes zero at a crossing frequency ("fc") of 100 KHz or below. The dielectric anisotropy of the liquid crystal is positive at frequencies lower than fc ("fl") and negative at frequencies higher than fc ("fh"). Crossed polarizers are disposed on each side of the liquid crystal panel. A liquid crystal driving circuit selectively applies a signal of a frequency fh to open the device and a signal of a frequency fl to close the device.
The optical device is particularly well suited for use as a light valve in a printer device. Response time within 1 m sec. permits a printing speed of 10 prints of A4 size to be produced per minute with a resolving power of about 10 dots per 1 m/m. This amounts to a printing speed of approximately 500 lines in one second with each line being written into m sec. or less. The optically active nematic liquid crystal is a composition comprising a optically inactive nematic liquid crystal and an optically active liquid crystal material added thereto.
REFERENCES:
patent: Re29684 (1978-06-01), Gordon
patent: 3622226 (1971-11-01), Matthies
patent: 3674338 (1972-07-01), Cartmell et al.
patent: 3722998 (1973-03-01), Morse
patent: 3744878 (1973-07-01), Kiemle et al.
patent: 3778149 (1973-12-01), Fields
patent: 3814501 (1974-06-01), Schindler
patent: 3832034 (1974-08-01), Edmonds
patent: 3840695 (1974-10-01), Fischer
patent: 3881809 (1975-05-01), Fergason
patent: 3936172 (1976-02-01), McVeigh
patent: 3989353 (1976-11-01), Phalan
patent: 4006968 (1977-02-01), Ernstoff et al.
patent: 4009934 (1977-03-01), Goodwin et al.
patent: 4023890 (1977-05-01), Shirasu
patent: 4097131 (1978-06-01), Nishiyama
patent: 4105288 (1978-08-01), Geffcken et al.
patent: 4219256 (1980-08-01), Gray et al.
patent: 4235526 (1980-11-01), Berman et al.
patent: 4236155 (1980-11-01), Nagata
patent: 4248517 (1981-02-01), Nishikawa
patent: 4278328 (1981-07-01), Mukoh et al.
patent: 4297022 (1981-10-01), Lester
patent: 4310858 (1982-01-01), Hareng et al.
patent: 4378956 (1983-04-01), Lester
patent: 4383738 (1983-05-01), Funada et al.
patent: 4386836 (1983-06-01), Aoki et al.
patent: 4392719 (1983-07-01), Sekimoto
patent: 4393390 (1973-07-01), Aoki
patent: 4482215 (1984-11-01), Sprague et al.
Castellano, "Now that the Heat is Off Liquid Crystals can Show their Color Everywhere" Electronics, Jul. 6, 1970, pp. 64-70.
Ishibashi et al., "1980 Biennial Display Research Conference on the Multiplexing of the Phase Change Type Color LCD" 1980 IEEE, pp. 186-188.
Aoki Kenji
Miura Teiji
Nagata Mitsuo
Nakamura Haruo
Lewis David
Miller Stanley D.
Seiko Epson Corporation
LandOfFree
Liquid crystal cell with opaque mask for printing device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Liquid crystal cell with opaque mask for printing device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Liquid crystal cell with opaque mask for printing device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1664353