| 摘要 |
PROBLEM TO BE SOLVED: To prevent surface potential at a part exposed before from being transited to an image carrier and to form a good-quality image having no ghost by specifying relation among the main sensitivity wavelength of the image carrier, the discharge wavelength of a discharge means and the wavelength of a latent image forming means. SOLUTION: The relation among the main sensitivity wavelengthλof a photoreceptor drum (image carrier) 1, the discharge wavelengthλc of a pre- exposure lamp (discharge means) 11 and the wavelengthλs of a laser exposure optical system (latent image forming means) 3 isλ=λc≠λs. Namely, an organic photoconductor is used as the drum 1, its main sensitivity wavelength region has a peak at 670 nm, and the pre-exposure lamp 11 uses the discharge wavelengthλc of the same wavelength region as the drum 1 so as to completely remove charge on the drum 1. Therefore, efficient discharge is performed. Then, an electrostatic latent image is formed by a laser beam having different wavelengthλs (780 nm) after the drum 1 is uniformly electrified to be negative by a corona electrifier 2. |
