Abstract: A high-sensitivity and long-life electrophotographic photoreceptor comprising an electroconductive substrate and at least a photosensitive layer on the electroconductive substrate is provided, wherein the photosensitive layer contains a polyarylate resin not having a nitrogen atom in its repeating unit, and the Hall mobility at an electric field strength of 3×105 (V/cm) and at a temperature of 21° C. of the photosensitive layer is 3×10−6 (cm2/Vs) or more.

Abstract: An image-forming apparatus comprising at least a photoreceptor, a toner and an exposure device, wherein the photoreceptor has a photosensitive layer containing oxytitanium phthalocyanine having a distinct diffraction peak at a Bragg angle (2&thgr;±0.2) of 27.3° in the X-ray diffraction by CuK&agr;-ray, and the toner has a volume average particle diameter (Dv) of from 3 to 8 &mgr;m and satisfies a relation of 1.0≦Dv/Dn≦1.3 where Dv is the volume average particle diameter and Dn is the number average particle diameter.

Abstract: The present invention provides a negative charging electrophotographic photoreceptor, which includes an electroconductive substrate; a charge generation layer disposed on the electroconductive substrate; and a charge transport layer disposed on the charge generation layer; wherein the charge transport layer is in a homogeneous state; and wherein the charge generation layer has a light transmittance of at least 10% per micrometer of film thickness of the charge generation layer, or wherein the photoreceptor has an E50/E10 ratio in the range of 1 to 6, or wherein the charge generation layer has a light transmittance of at least 68% per micrometer of film thickness of the charge generation layer. The present invention provides methods of making and using the electrophotographic photoreceptor, and apparatuses which include the electrophotographic photoreceptor.

Abstract: A high-sensitivity and long-life electrophotographic photoreceptor comprising an electroconductive substrate and at least a photosensitive layer on the electroconductive substrate is provided, wherein the photosensitive layer contains a polyarylate resin not having a nitrogen atom in its repeating unit, and the Hall mobility at an electric field strength of 3×105 (V/cm) and at a temperature of 21° C. of the photosensitive layer is 3×10−6 (cm2/Vs) or more.

Abstract: An electrophotographic photoreceptor having a photosensitive layer containing a charge generation material and a charge transport material on an electroconductive substrate, wherein the charge transport material has a polarizability .alpha. of the formula, .alpha.>100 (.ANG..sup.3) and a dipole moment P of the formula, P<1.6 (D).

Abstract: An optical information processing element characterized by having a photoelectric and a memory layer provided with a function holding an electricity-conducting property which has been changed by radiation of light having a constant wavelength between electrodes at least one of which is provided with a light-transmitting property.