To reproduce a latent image with high gradation and high resolution at high fidelity by uniformizing the contact state between a charging roller and a photoreceptor to reduce charging irregularity, and to meet the need of miniaturization and fast operation.
A photoreceptor cartridge having at least a photoreceptor 1 and a charging device 2 is constituted in such a manner that: the photoreceptor 1 is formed into a cylinder having 10 to 40 mm in diameter and has a photosensitive layer containing oxytitanium phthalocyanine which shows, in the X-ray diffraction by CuKα beam, a major diffraction peak at 27.3° of Bragg angle (2θ±0.2); the charging device 2 is provided as a charging roller having 5 to 20 mm in diameter; and the charging roller has an elastic layer having 20° to 80° hardness measured with an ASKER C-type hardness meter and forming a contact face with the photoreceptor 1.
MITSUHASHI KAZUO
ISHIKAWA TOMOKO
KURIHARA SHUNICHIRO
Next Patent: CONFOCAL MICROSCOPE