Abstract: First and second patterns are located outside of an image reading area. A first pattern comprises a plurality of lines each extending at a fixed angle with respect to a sub-scan direction. A second pattern comprises a plurality of lines each extending at a fixed angle but having a reverse direction with respect to the sub-scan direction. An image reading portion reads the first and second patterns. A position error measuring portion measures first and second image reading position errors corresponding to different angle oblique lines of the first and second patterns of image data obtained as a result of reading the first and second patterns, respectively. The position error measuring portion compensates for position deviations of the first and second patterns using the first and second image reading position errors, and obtains position-deviation-compensated image reading position errors.

Abstract: An image processing system for smoothing edges of an image, includes a sampling part for sampling a group of dots from an image having a plurality of input black and white dots, the group of dots having a target dot at the center of a region and being sampled for each dot of the image, a recognition part for recognizing a dot pattern from the sampled dots, the dot pattern described by successive black dots and located at a boundary between a black dot region and a white dot region, and for producing code signals from the result of the recognition to define features of the dot pattern for each target dot, a discrimination part for detecting whether or not each target dot is part of an inclined line having a gradient relative to horizontal or vertical direction in response to the code signals, thus determining whether or not each target dot is to be corrected, a correction part with a memory, for inputting the code signals to the memory as address inputs when the dot is to be corrected, and for outputting a cor

Abstract: In a copying machine for both black-and-white and color, a latent image of an original is formed in a photosensitive device by scanning the original by a scanning optical system and is developed by a black or color toner and is thereafter transferred onto a transfer paper held on transfer device rotated in proximity to the photosensitive device to provide a copy of the original. The copying machine includes a first drive unit for driving the scanning optical system; a second drive unit for driving the photosensitive device; a third drive unit for driving the transfer device; and a drive condition setting device for judging a designated copy mode and for giving the speeds of the respective drive units which are suitable for the designated copy mode.

Abstract: An image forming apparatus has a latent image carrier for carrying an electrostatic latent image formed thereon. The electrostatic latent image is developed into a visible image which is transferred from the latent image carrier onto a transfer sheet in an image transfer region. The transfer sheet is held on a drum-shaped or a belt-shaped holder with the leading end clamped by a clamp. For efficient image formation, the holder is accelerated and decelerated while the transfer sheet is out of the image transfer region. When the transfer sheet with the transferred image thereon is sent to an image fixing device, the holder is accelerated and decelerated during an interval after the trailing end of the transfer sheet has left the image transfer region and before the leading end of the transfer sheet reaches the image fixing device. After the holder has been accelerated and decelerated, it is positionally adjusted when required.