Electrophotographic photoreceptor having excellent lifetime characteristics and charge uniformity, and electrophotographic image forming apparatus and electrophotographic cartridge using the electrophotographic photo receptor

An electrophotographic image forming apparatus comprising:

• an electrophotographic photoreceptor;
• a charging device charging the electrophotographic photoreceptor in contact with the electrophotographic photoreceptor;
• an exposure device forming an electrostatic latent image on a surface of the electrophotographic photoreceptor;
• a developing device developing the electrostatic latent image to form a visible image;
• a transferring device transferring the visible image on an image receiving member;
• and
• a cleaning device cleaning the surface of the electrophotographic photoreceptor after the transferring,
• wherein the electrophotographic photoreceptor comprises an electrically conductive substrate;
• and
• an undercoat layer (UL), a charge generation layer (CGL), and a charge transport layer (CTL) sequentially disposed on the electrically conductive substrate,
• wherein a characteristic response time of the photoreceptor is about 10 msec or more and about 85 msec or less and a thickness of the charge transport layer is greater than about 18 μm and equal to or less than about 45 μm:
• wherein the characteristic response time is denoted as a shortest response time in a range of response times generating characteristic photoinduced discharge curves (PIDC), the response time is denoted as a time elapsed from the moment of light exposure of the laminate type electrophotographic photoreceptor to the moment of development thereof, and the characteristic PIDC is denoted, in a photoinduced discharge characteristic test in which the laminate type electrophotographic photoreceptor is charged to have an initial surface potential range of about −500 V to about −700 V by using a direct current (DC) contact charging method in an environment of a temperature of 23° C. and a relative humidity of 50% and, thereafter, the laminate type electrophotographic photoreceptor is exposed to monochromatic light having a wavelength of about 780 nm, as a PIDC exhibiting a saturation phenomenon in which the surface potential of the laminate type electrophotographic photoreceptor after the light exposure is in a range of about 0 V to about −200 V and the surface potential of the laminate type electrophotographic photoreceptor after the light exposure does not change about ±10 V or more even when exposure energy increases 10 times.

An electrophotographic cartridge integrally supporting an electrophotographic photoreceptor comprising:

• at least one device selected from the group consisting of a charging device charging the electrophotographic photoreceptor in contact with the electrophotographic photoreceptor, a developing device developing an electrostatic latent image formed on the electrophotographic photoreceptor to form a visible image, a transferring device transferring the visible image on an image receiving member and a cleaning device cleaning a surface of the electrophotographic photoreceptor after transferring, and attachable to an electrophotographic image forming apparatus and detachable from the electrophotographic image forming apparatus,
• wherein the electrophotographic photoreceptor comprises an electrically conductive substrate;
• and
• an undercoat layer (UL), a charge generation layer (CGL), and a charge transport layer (CTL) sequentially disposed on the electrically conductive substrate,
• wherein a characteristic response time of the photoreceptor is about 10 msec or more and about 85 msec or less and a thickness of the charge transport layer is greater than about 18 μm and equal to or less than about 45 μm:
• wherein the characteristic response time is denoted as a shortest response time in a range of response times generating characteristic photoinduced discharge curves (PIDC), the response time is denoted as a time elapsed from the moment of light exposure of the laminate type electrophotographic photoreceptor to the moment of development thereof, and the characteristic PIDC is denoted, in a photoinduced discharge characteristic test in which the laminate type electrophotographic photoreceptor is charged to have an initial surface potential range of about −500 V to about −700 V by using a direct current (DC) contact charging method in an environment of a temperature of 23° C. and a relative humidity of 50% and, thereafter, the laminate type electrophotographic photoreceptor is exposed to monochromatic light having a wavelength of about 780 nm, as a PIDC exhibiting a saturation phenomenon in which the surface potential of the laminate type electrophotographic photoreceptor after the light exposure is in a range of about 0 V to about −200 V and the surface potential of the laminate type electrophotographic photoreceptor after the light exposure does not change about ±10 V or more even when exposure energy increases 10 times.