Photocopying – Contact printing – Light boxes
Patent
1992-03-09
1995-09-12
Picard, Leo P.
Photocopying
Contact printing
Light boxes
355245, G03G 500
Patent
active
054501687
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to a moving image pickup device which can pick up images of good quality by making use of a recording medium capable of forming an electrostatic latent image, while influences of residual charges on the surface of a photosensitive material are eliminated by exposure, a medium for picking up moving images and a process for picking up images continuously.
BACKGROUND TECHNIQUE
As well known in the art, there is available an exposure system with the application of voltage (hereinafter called simply voltage-applied exposure) in which, while a photosensitive material having a photoconductive layer on an electrically conductive layer is located in opposition to a charge carrier medium having an insulating layer on an electrically conductive layer, an image is exposed to light with voltage applied between both said electrically conductive layers, thereby forming an electrostatic latent image on the charge carrier medium.
Such voltage-applied exposure is schematically illustrated in FIGS. 1(a)-1(d) wherein reference numeral 1 stands for a charge carrier medium, 1a an insulating layer, 1b a charge carrier medium electrode, 1c an insulating layer support, 2 a photosensitive material, 2a a photoconductor support, 2b an electrode of photosensitive material, 2c a photoconductive layer and E a power source.
The photoconductor support 2a formed of 1-mm thick glass is provided thereon with the transparent photosensitive electrode 2b formed of 1000-.ANG. thick ITO, which is then provided thereon with the photoconductive layer 2c of about 10 .mu.m in thickness to form the photosensitive material 2. With respect to this material 2, there is located the charge carrier medium 1 through an air gap of about 10 .mu.m. The charge carrier medium 1 is formed by the vapor deposition of a 1000-.ANG. thick aluminium electrode 1b on the insulating layer support 1c formed of 1-mm thick glass and the formation of a 10-.mu.m thick insulating layer 10 on this electrode 1b.
As illustrated in FIG. 1a, the charge carrier medium 1 is first located with respect to the photosensitive material 2 through an air gap of the order of 10 .mu.m, and voltage is applied between the electrodes 2b and 1b through the power source E. In a dark place, no change will occur between the electrodes, or uniform discharge will take place between the photoconductive layer 2c and the insulating layer 1a due to a minute dark current flowing through the former during the application of voltage, whereby charges corresponding to the dark current are built up on the insulating layer 1a. This is because the photoconductive layer 2c is of high resistance. Upon incidence of light from the side of the photosensitive material 2, charge carriers (electrons and positive holes) are produced through the region of the photoconductive layer 2c upon which the light strikes, so that major carriers can migrate onto the surface of the photoconductive layer 2c. As a result, discharge takes place between the photoconductive layer 2c and the insulating layer 1a, thus allowing charges to be accumulated on the insulating layer 1a in a quantity corresponding to the exposure dose.
After the completion of exposure, the voltage is turned off, as shown in FIG. 1c, and the charge carrier medium 1 is removed, as depicted in FIG. 1d, to finish the formation of an electrostatic latent image.
When this recording procedure is applied to planar analog recording, high resolution is obtained as is the case with silver salt photography. In addition, although the surface charges formed on the insulating layer 1a are exposed to an air atmosphere, they can be kept without discharge over an extended period of time regardless of whether they are stored in a dark or bright place, because air is a good insulator.
The applicant has already proposed a process for forming an electrostatic latent image using a pre-electrified charge carrier medium or photosensitive material, in which an image is exposed to light while both the electrically conductive layers remain short-circui
REFERENCES:
patent: 3502408 (1970-03-01), Brodie
patent: 3692404 (1972-09-01), Lester et al.
patent: 4273438 (1981-06-01), Nishikawa
patent: 4494858 (1985-01-01), Gage et al.
patent: 4803514 (1989-02-01), Hiratsuka et al.
patent: 5057875 (1991-10-01), Itoh
patent: 5119133 (1992-06-01), Swain
patent: 5291246 (1994-03-01), Tsukamoto
Aono Takashi
Obata Hiroyuki
Takano Atsushi
Utsumi Minoru
Dai Nippon Printing Co. Ltd.
Horgan Christopher
Picard Leo P.
LandOfFree
Moving image pickup device, medium for picking up moving images does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Moving image pickup device, medium for picking up moving images , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Moving image pickup device, medium for picking up moving images will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-409084