With reference to a correction value revision parameter table, a periodic non-uniformity correction value corresponding to changed rotational speed is obtained from the correction value revision parameter table, and set as a new periodic non-uniformity correction value corresponding to the rotational speed of a rotary component, and thereby a gradation which is an image formation parameter of image data is corrected.

An image forming apparatus includes a light-receiving unit that includes light-receiving elements arranged along a movement direction of a target formed on an image carrier, and is arranged so as to receive light emitted from a light-emitting unit and specularly reflected off the image carrier; a member configured to limit a size, in the movement direction, of diffused reflection light that is incident on the light-receiving unit; a selection unit configured to select whether or not each of the light-receiving elements in the light-receiving unit is an effective light-receiving element; a generation unit configured to generate a detection signal from an output of the effective light-receiving element; and a detection unit configured to detect a target formed on the image carrier based on the detection signal.

An image forming apparatus includes a light-receiving unit that includes light-receiving elements arranged along a movement direction of a target formed on an image carrier, and is arranged so as to receive light emitted from a light-emitting unit and specularly reflected off the image carrier; a member configured to limit a size, in the movement direction, of diffused reflection light that is incident on the light-receiving unit; a selection unit configured to select whether or not each of the light-receiving elements in the light-receiving unit is an effective light-receiving element; a generation unit configured to generate a detection signal from an output of the effective light-receiving element; and a detection unit configured to detect a target formed on the image carrier based on the detection signal.

An image forming apparatus includes a light-receiving unit that includes light-receiving elements arranged along a movement direction of a target formed on an image carrier, and is arranged so as to receive light emitted from a light-emitting unit and specularly reflected off the image carrier; a member configured to limit a size, in the movement direction, of diffused reflection light that is incident on the light-receiving unit; a selection unit configured to select whether or not each of the light-receiving elements in the light-receiving unit is an effective light-receiving element; a generation unit configured to generate a detection signal from an output of the effective light-receiving element; and a detection unit configured to detect a target formed on the image carrier based on the detection signal.

There are provided an image reading device and a printing apparatus that can reduce an influence of the shadows of suction holes. Suction holes, which are used to suck a sheet, are arranged on the peripheral surface of a drum that transports the sheet. The suction holes are arranged in grooves that are formed along a direction orthogonal to a transport direction. Accordingly, since an influence of the shadows of the suction holes can be reduced even in a case in which density unevenness is inspected on the basis of a read image, the false detection of density unevenness can be prevented.

There are provided an image reading device and a printing apparatus that can reduce an influence of the shadows of suction holes. Suction holes, which are used to suck a sheet, are arranged on the peripheral surface of a drum that transports the sheet. The suction holes are arranged in grooves that are formed along a direction orthogonal to a transport direction. Accordingly, since an influence of the shadows of the suction holes can be reduced even in a case in which density unevenness is inspected on the basis of a read image, the false detection of density unevenness can be prevented.

An image forming apparatus includes: a light-receiving unit that includes light-receiving elements arranged along a movement direction of a target formed on an image carrier, and is arranged so as to receive light emitted from a light-emitting unit and specularly reflected off the image carrier; a member configured to limit a size of diffused reflection light that is incident on the light-receiving unit in the movement direction; a selection unit configured to select whether or not each of the light-receiving elements in the light-receiving unit is a effective light-receiving element; a generation unit configured to generate a detection signal from an output of the effective light-receiving element; and a detection unit configured to detect a target formed on the image carrier based on the detection signal.

An assembly for transferring information to and/or from flexible sheet media in a highly advantageous curved configuration is disclosed. The sheet material includes a length and a width defining first and second opposing surfaces. The assembly includes support means for supporting the sheet the curved configuration across its width, having the first surface inwardly oriented with respect to the curved configuration. Thereafter, moving means moves the flexible sheet material so supported in a direction along a read/write path generally parallel to the sheet material length and transverse to the direction of curvature. A read/write arrangement is provided which is configured for reading and/or writing information across the width of the first surface of the sheet as the sheet is moved along the path in the curved configuration. In one feature, means is provided for rotationally moving the read/write arrangement in a predetermined way in the housing such that the read/write arrangement is in a confronting relationship with the first, inwardly oriented surface and cooperates with the movement provided by the sheet material moving means so as to cause the read/write arrangement to sequentially read information from and/or write information to the inwardly oriented, first surface of the sheet as the read/write arrangement traverses the width of the flexible sheet material while the latter is on the read/write path in the curved configuration. In another feature, a read and/or write operation may be performed on the second, outwardly oriented surface of the sheet material.

With reference to a correction value revision parameter table, a periodic non-uniformity correction value corresponding to changed rotational speed is obtained from the correction value revision parameter table, and set as a new periodic non-uniformity correction value corresponding to the rotational speed of a rotary component, and thereby a gradation which is an image formation parameter of image data is corrected.

An imager apparatus useful for a digital architecture lithographic printing system includes a first imager bank having at least one imager configured to produce a first output beam; and a second imager bank having at least one imager configured to produce a second output beam, the second imager bank being located at a first angle with respect to the first imager bank, the first output beam and the second output beam being separated by a second angle which is less than the first angle.