JPS5576364A - Contact type squeeze roll - Google Patents

Abstract

PURPOSE:To improve the squeeze effect and obtain excellent images, by constituting the roll part of gate roll to squeeze out the excess developing solution in a plain paper electrostatic copier of wet type developing system with a specified sponge rubber. CONSTITUTION:A photosensitive drum 1 rotates in the direction of arrows toward a corona discharger 2, an exposure window 3, and a developing device 4, and the excess developer deposited on the drum 1 in the developing device 4 is squeezed out by a gate roll 5. To make this roll 5, a nitrile rubber sponge of which porosity is about 60%, ASKER c-type hardness is less than 30 deg.C, and volume resistivity is less than 10<7>OMEGAcm is integrally formed around the shaft of the roll 5. Thus, by rotating the roll 5 and drum 1 in mutually opposite directions while keeping tight contact, the excess developer may be squeezed effectively, and an excellent copy image may be obtained in a copy paper 9 in the next copying process. After copying, the deposited developing solution is removed from the drum 1 through destaticizer 15, squeeze roller 16, and cleaning blade 17.