52 results about "Dark time" patented technology

An electrophotographic photosensitive member superior in dot reproducibility and a process cartridge and an process cartridge having the electrophotographic photosensitive member are provided. Where in a light attenuation curve drawn in a way in which the surface of the electrophotographic photosensitive member is so charged that intensity of an electric field is 15 (V / μm) to establish the surface potential of the electrophotographic photosensitive member into a given value E(V) and then exposed to light under conditions that the electrophotographic photosensitive member has a surface potential of 0.8 E(V) at a time point T(ms) passes after exposure starts, the inclination of the light attenuation curve at a time point T(ms) passes after exposure starts is represented by m, and in a dark-time surface potential attenuation curve drawn in a way in which the surface of the electrophotographic photosensitive member is charged under conditions that the electrophotographic photosensitive member has a surface potential of 0.8 E(V) at a time point T(ms) passes after charging is finished and thereafter no exposure is performed, the inclination of the dark-time surface potential attenuation curve at a time point T(ms) passes after charging is finished is represented by m′, the m and m′ satisfy |m−m′|≦0.020, provided that T=[{d2 / (μ×E)}×100]×10−5, where d is the layer thickness (μm) of the charge transport layer and μ is the drift mobility [cm2 / (V·s)] of the charge transport layer.

A pixel area, which is composed of a plurality of unit pixels each including a photoelectric conversion unit and a signal scanning circuit, is formed on a semiconductor substrate. An optical black pixel region, in which a plurality of optical black pixels for setting a dark-time level are formed, is formed in the pixel area. A barrier layer, which has an impurity concentration that is higher than an impurity concentration of the semiconductor substrate and has a conductivity type that is identical to a conductivity type of the semiconductor substrate, is formed in the optical black pixel region of the semiconductor substrate.

An image reading device includes a document reading unit configured to guide light emitted from a light source to a photoelectric conversion unit to read an image on the document; a driving unit configured to drive the document reading unit so that the document reading unit reciprocates along the document; a reading position obtaining unit configured to obtain a home position at which the document reading unit is in a stopped state when starting a read operation; a dark time data obtaining unit configured to obtain dark time output data of the photoelectric conversion unit while the light source is turned off; and a read control unit configured to perform control for causing the driving unit to return the document reading unit to the home position and entering a document read operation to read a document image after the dark time data obtaining unit obtains the dark time output data.