A conveyance apparatus includes a separation unit configured to separate and convey a sheet, a detection unit configured to detect a floating of the sheet passing through the separation unit, and a control unit configured to stop separate conveyance by the separation unit if the detection unit detects the sheet for not less than a predetermined time and/or a predetermined count.

A control unit causes a carriage to move in a width direction under a first movement control of changing a location of the carriage with a first resolution so that a sensor located forward in movement detects an edge of a medium. Thereafter, the first movement control is switched to a second movement control of changing the location of the carriage with a second resolution higher than the first resolution and the carriage is caused to move in the width direction so that a sensor located rearward in movement detects the edge.

An image processing device includes a processor configured to: obtain image information obtained by reading a sheet that is folded with an intention that a folding line is formed at a position apart from a sheet center position in a specific direction by a predetermined distance, using an image reading device in a state in which a short folded piece of the sheet faces a sensor surface; obtain positions of two edges that are opposite to each other across a folding back of the sheet in the image information; and detect a deviation amount of the folding line based on the positions of the two edges and the predetermined distance.

An information processing device executes: acquiring a scanned image of a document and a protective sheet that protects the document, the scanned image being obtained by imaging the document and the protective sheet while being conveyed at the same time; acquiring a first length that is a conveying direction length of a predetermined portion of the protective sheet; acquiring a second length that is a conveying direction length of the predetermined portion in the scanned image; and estimating a ratio between a document length, which is a conveying direction length of the document, and a document image length, which is a conveying direction length of the document in the scanned image, based on the first length and the second length.

A controller of an image reading apparatus is configured to cause the reading device to read an image on an original with moving a reading location from a first position to a second position, after reading the image on the original with moving the reading location from a third position to the first position, the third position being a position between the first position and the second position and spaced from the first position by a particular distance and determining a width of the original in the main scanning direction. The controller is configured to further move the reading location from the second position to the first position, and detect an instruction to continue reading a subsequent original during a period before the reading location reaches the third position. When the instruction is detected, the controller stops moving the reading location when it reaches the third position.

An image reading apparatus is capable of reducing glare that a user feels while PWM-controlling an LED and of detecting an original size in a principal scanning direction with sufficient accuracy. A line sensor receives light emitted from a light source and reflected by an original. When a pressure plate that presses an original to a platen is closed, a control unit controls to supply a line periodic signal of which a period is longer than that for reading an original image to the line sensor, and to supply a lighting control signal of which a duty ratio is smaller than that for reading the original image to the light source in synchronization with the line periodic signal to light the light source and to read an image, and controls to detect length of the original in the principal scanning direction using the image signals from the line sensor.

An image reading apparatus includes a transparent member on which an original is placed, a reading unit configured to read the original placed on the transparent member while moving in a first direction, and at least one processor configured to detect at least one edge of the original based on a reading result by the reading unit, wherein the at least one processor is configured to determine a candidate of a size of the original placed on the transparent member based on an edge, among the at least one detected edge, in the second direction orthogonal to the first direction, wherein the reading unit is configured to move in the first direction by a predetermined distance based on the candidate of the determined size.

A reading portion generates an original image including an image of a document sheet. A first document sheet end detection portion, in a case where the thickness of the document sheet is equal to or greater than a threshold value, identifies a peripheral edge shape of the document sheet by detecting a shadow portion that occurs at a peripheral edge portion of the document sheet in the original image. A second document end detection portion, in a case where the thickness of the document sheet is less than a threshold value, identifies the peripheral edge shape based on a specification by the user. A document sheet size determination portion determines a size of the document sheet according to a result of shape identification by the first document sheet end detection portion or a result of shape identification by the second document sheet end detection portion.

An information processing device executes: acquiring a scanned image of a document and a protective sheet that protects the document, the scanned image being obtained by imaging the document and the protective sheet while being conveyed at the same time; acquiring a first length that is a conveying direction length of a predetermined portion of the protective sheet; acquiring a second length that is a conveying direction length of the predetermined portion in the scanned image; and estimating a ratio between a document length, which is a conveying direction length of the document, and a document image length, which is a conveying direction length of the document in the scanned image, based on the first length and the second length.

An image forming device and a sheet conveyance method are provided. An image forming device includes a feeder, a first conveyor, a second conveyor, and a conveyance controller. The feeder aligns a sheet and feeds the sheet to a transfer system that transfers an image to the sheet. The first conveyor is arranged at a first position on an upstream side of the feeder in a sheet conveyance direction and conveys the sheet to the feeder. The second conveyor is arranged at a second position on an upstream side of the first conveyor in the sheet conveyance direction and conveys the sheet to the first conveyor. The conveyance controller performs high-speed control for causing a conveyance speed of the second conveyor to exceed a conveyance speed of the first conveyor when a specific sheet different from a normal sheet is fed by the feeder.