A detecting device, which is included in an image forming apparatus, includes a detector configured to optically detect at least one of a position of a sheet, a position of an image formed on the sheet, and the image formed on the sheet, and a rotary body disposed at a position opposed to the detector and having a shaft, the rotary body being rotatable about the shaft in a sheet conveying direction of the sheet. The sheet is conveyed to space between the detector and the rotary body. The rotary body has a reference plane on an outer circumferential surface, a line formed on the reference plane and extending in a width direction perpendicular to the sheet conveying direction. The detector detects the line on the reference plane while the rotary body is rotating when the sheet does not intervene between the detector and the rotary body.

A method of grouping sheet units, which belong together in sheet groups, a sheet stream comprising two superposed sheet units each by means of a grouping unit, a grouping unit for a sheet handling system, and a sheet handling system that allow a high processing speed and a high cycle efficiency of a sheet handling system are disclosed. A sheet unit can be held back in the grouping unit. Depending on whether the downstream subsequent sheet units transferred into the grouping unit belong to a sheet group, the held-back sheet unit can be released by itself and together with one or together with both downstream subsequent sheet units.

A method of grouping sheet units, which belong together in sheet groups, a sheet stream comprising two superposed sheet units each by means of a grouping unit, a grouping unit for a sheet handling system, and a sheet handling system that allow a high processing speed and a high cycle efficiency of a sheet handling system are disclosed. A sheet unit can be held back in the grouping unit. Depending on whether the downstream subsequent sheet units transferred into the grouping unit belong to a sheet group, the held-back sheet unit can be released by itself and together with one or together with both downstream subsequent sheet units.

To prevent a failure or the like caused by winding of a tape in a reverse direction to a proper direction, a paper sheet circulation device includes a travelling-direction mark having a pattern that is formed along a travelling-direction of a detection tape and indicates the difference of the travelling-direction of the tape, and a sensor module that detects the travelling-direction mark and outputs a detection signal. The paper sheet circulation device determines a travelling-direction of the tape from a pattern signal in accordance with the travelling-direction of the tape acquired on the basis of a temporal change of the detection signal, and determines a winding direction of the tape on a drum from the travelling-direction of the tape and a rotation direction of the drum.

To prevent a failure or the like caused by winding of a tape in a reverse direction to a proper direction, a paper sheet circulation device includes a travelling-direction mark having a pattern that is formed along a travelling-direction of a detection tape and indicates the difference of the travelling-direction of the tape, and a sensor module that detects the travelling-direction mark and outputs a detection signal. The paper sheet circulation device determines a travelling-direction of the tape from a pattern signal in accordance with the travelling-direction of the tape acquired on the basis of a temporal change of the detection signal, and determines a winding direction of the tape on a drum from the travelling-direction of the tape and a rotation direction of the drum.

A sheet fed device having a media tray and a sensor assembly is disclosed. The media tray includes a major surface having a leading portion and a trailing portion. The sensor assembly is operably coupled to the media tray. The sensor assembly includes a detector spaced-apart from and movable relative to the media tray in a path laterally across the major surface between the leading portion and the trailing portion.

A sheet fed device having a media tray and a sensor assembly is disclosed. The media tray includes a major surface having a leading portion and a trailing portion. The sensor assembly is operably coupled to the media tray. The sensor assembly includes a detector spaced-apart from and movable relative to the media tray in a path laterally across the major surface between the leading portion and the trailing portion.

An image forming apparatus includes first and second sheet storages, a sheet conveyer, an image reading unit configured to read a surface of a sheet conveyed from the first sheet storage by the sheet conveyer, an image forming unit configured to form an image on the sheet conveyed from the image reading unit, and a controller. The controller is configured to determine an amount of a color material appearing on the surface of the sheet based on image data generated by the image reading unit, determine one of the image forming unit and the second sheet storage as a sheet feeding destination, based on the determined amount of the color material and a threshold value that is associated with at least one of a type and content of an image to be formed on the sheet, and control the sheet conveyer to convey the sheet to the sheet feeding destination.

A register (20; 60) for a processing machine (1) for processing plate-like elements (10) includes a gripping element (21; 22) for placing the plate-like elements (10) in a gripper bar (31) of a conveyor (30) of a processing machine (1) conveying the plate-like elements (10) in a longitudinal direction, an actuator module (201, 202) to drive the gripping element (21; 22), at least one front correction sensor module (7) configured to measure the front position of register marks (12a) printed on a front section of the plate-like element (10) grasped by the gripping element (21; 22). The register (20; 60) includes at least one front pre-correction sensor module (80), placed upstream of the front correction sensor module (7) in the longitudinal direction, the front pre-correction sensor module (80) is configured: to detect the passage of a front transversel edge of the plate-like element (10) in at least two longitudinally spaced lateral axis of detection (P1, P2), one located in front of the other, and to provide measurements to a computation and control unit (40) of the processing machine (1) that is configured: to control the actuator module (201, 202) in order to move the gripping element (21; 22) toward the gripper bar (31) and to activate the gripping element (21; 22) in order to grasp a plate-like element (10). Also a processing machine for processing plate-like elements includes the register. A method for placing plate-like elements within a processing machine is disclosed.

A register (20; 60) for a processing machine (1) for processing plate-like elements (10) includes a gripping element (21; 22) for placing the plate-like elements (10) in a gripper bar (31) of a conveyor (30) of a processing machine (1) conveying the plate-like elements (10) in a longitudinal direction, an actuator module (201, 202) to drive the gripping element (21; 22), at least one front correction sensor module (7) configured to measure the front position of register marks (12a) printed on a front section of the plate-like element (10) grasped by the gripping element (21; 22). The register (20; 60) includes at least one front pre-correction sensor module (80), placed upstream of the front correction sensor module (7) in the longitudinal direction, the front pre-correction sensor module (80) is configured: to detect the passage of a front transversel edge of the plate-like element (10) in at least two longitudinally spaced lateral axis of detection (P1, P2), one located in front of the other, and to provide measurements to a computation and control unit (40) of the processing machine (1) that is configured: to control the actuator module (201, 202) in order to move the gripping element (21; 22) toward the gripper bar (31) and to activate the gripping element (21; 22) in order to grasp a plate-like element (10). Also a processing machine for processing plate-like elements includes the register. A method for placing plate-like elements within a processing machine is disclosed.