Photocopying – Projection printing and copying cameras – Combined with or convertible to a contact printer
Patent
1980-08-27
1982-01-12
Moses, R. L.
Photocopying
Projection printing and copying cameras
Combined with or convertible to a contact printer
118689, 222DIG1, 355 10, G03G 1500
Patent
active
043102387
ABSTRACT:
First and second sensors (37), (39) are provided in a developing tank (36) containing a liquid developer consisting of a liquid carrier or dispersant and toner particles dispersed in the carrier. The first sensor (37) measures the electrical resistivity of the developer whereas the second sensor (39) measures the optical transmissibility thereof. Additional toner is supplied into the developer to maintain the transmissivity at a value which is a predetermined function of the resistivity. The transmissibility value is reduced as the resistivity increases, thereby maintaining the copy image density constant. The first sensor (37) includes two electrodes immersed in the developer and an A.C. or D.C. voltage is applied thereacross. The current flow through the electrodes (37) and thereby the developer is measured to determine the resistivity of the developer. Where the applied voltage is D.C., an arrangement is provided to mechanically scrape accumulated developer off the electrodes (37) at intermittent intervals.
REFERENCES:
patent: 3233781 (1966-02-01), Grubbs
patent: 3369524 (1968-02-01), Fuhrer
patent: 3572551 (1971-03-01), Gillespie et al.
patent: 3674353 (1972-07-01), Trachtenberg
patent: 3712203 (1973-01-01), Kishi et al.
patent: 3830401 (1974-08-01), Benwood et al.
patent: 3870197 (1975-03-01), Landrith
patent: 3876106 (1975-04-01), Powell et al.
patent: 3910459 (1975-10-01), Bock et al.
patent: 3932034 (1976-01-01), Takahashi
patent: 4043293 (1977-08-01), Ruckdeschel
patent: 4222497 (1980-09-01), Lloyd et al.
patent: 4226525 (1980-10-01), Sakamoto et al.
Hashimoto Junichiro
Kimura Taro
Miyakawa Seiichi
Mochizuki Manabu
Alexander David G.
Moses R. L.
Ricoh & Company, Ltd.
LandOfFree
Electrostatic copying apparatus does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Electrostatic copying apparatus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Electrostatic copying apparatus will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1538961