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.

A medium conveying apparatus includes a medium tray, a feed roller, an upper guide, a movement sensor including an arm movably provided by the fed medium on the upper guide and on an upstream side of the feed roller, to generate a movement amount signal corresponding to a movement amount of the arm, a medium sensor to detect a presence of the medium at a predetermined position of the medium tray, a processor to determine whether a feeding abnormality of the medium has occurred based on the movement amount signal, detect a size of the medium placed on the medium tray based on a detection result by the medium sensor, and stop feeding of the medium by the feed roller when the processor determines that the feeding abnormality of the media has occurred and the detected size of the media is equal to or less than a predetermined size.

A conveyor includes a first conveyance path along which a sheet is conveyed in a first direction, a second conveyance path along which the sheet is conveyed in a second direction different from the first direction, a switching part configured to switch a conveyance direction of the sheet between the first direction and the second direction, a sheet detector configured to detect the sheet at the switching part, a conveyance system driver configured to convey and stop the sheet, and circuitry configured to control the conveyance system driver to stop conveyance of the sheet in a predetermined condition, control the sheet detector to detect the sheet at the switching part, and control the switching part to switch the conveyance direction of the sheet from the first direction to the second direction when the sheet detector does not detect the sheet at the switching part.

A conveyor includes a first conveyance path along which a sheet is conveyed in a first direction, a second conveyance path along which the sheet is conveyed in a second direction different from the first direction, a switching part configured to switch a conveyance direction of the sheet between the first direction and the second direction, a sheet detector configured to detect the sheet at the switching part, a conveyance system driver configured to convey and stop the sheet, and circuitry configured to control the conveyance system driver to stop conveyance of the sheet in a predetermined condition, control the sheet detector to detect the sheet at the switching part, and control the switching part to switch the conveyance direction of the sheet from the first direction to the second direction when the sheet detector does not detect the sheet at the switching part.

An ultrasonic apparatus includes a first ultrasonic sensor that transmits an ultrasonic wave to an object and receives the ultrasonic wave reflected by the object, a second ultrasonic sensor that transmits an ultrasonic wave to the object and receives the ultrasonic wave reflected by the object, an determination circuit that outputs an error signal when the difference between a first distance between the first ultrasonic sensor and the object calculated based on ultrasonic wave transmission and reception processing using the first ultrasonic sensor and a second distance between the second ultrasonic sensor and the object calculated based on ultrasonic wave transmission and reception processing using the second ultrasonic sensor is equal to or greater than a threshold value.

A sheet stacking device includes a sheet accommodating unit, a pair of wall portions and a loading plate. The sheet accommodating unit has an open upper surface part and accommodates sheets therein. The sheets have a pair of first side edges extending in a first direction and a pair of second side edges perpendicular to the first direction. The pair of wall portions stands to face the first side edges of the sheets. The loading plate is arranged in the sheet accommodating unit. Each of the pair of wall portions includes a first observation port for exposing one end of the first side edges of the sheets in the first direction and an one area of the inner part outer than the one end in the first direction to outside of the sheet accommodating unit.

A medium conveying apparatus includes a first optical sensor located on an upper part of the housing and in a central part of the housing in a direction perpendicular to a medium conveying direction, a second optical sensor located on an upper part of the housing and on a side of the first optical sensor in the direction perpendicular to the medium conveying direction, and a processor to detect a folding of a medium based on the first signal or the second signal, and stop feeding of the medium by the feed roller in accordance with a detection result of the folding of the medium. The first light emitter emits first light toward a downstream side of the medium in the medium conveying direction, and the second light emitter emits second light toward an upstream side of the medium in the medium conveying direction.

A medium conveying apparatus includes a first optical sensor located on an upper part of the housing and in a central part of the housing in a direction perpendicular to a medium conveying direction, a second optical sensor located on an upper part of the housing and on a side of the first optical sensor in the direction perpendicular to the medium conveying direction, and a processor to detect a folding of a medium based on the first signal or the second signal, and stop feeding of the medium by the feed roller in accordance with a detection result of the folding of the medium. The first light emitter emits first light toward a downstream side of the medium in the medium conveying direction, and the second light emitter emits second light toward an upstream side of the medium in the medium conveying direction.

An image forming apparatus includes a sheet storage unit including a sheet tray on which one or more sheets are to be stacked, a sensor configured to detect that the sheet storage unit is being operated, and a processor configured to execute a predetermined process after the sensor detects that the sheet storage unit has been operated, and a predetermined condition relating to an occurrence of the sheet conveyance error is satisfied.

A medium conveying apparatus includes a first optical sensor located on an upper part of the housing and in a central part of the housing in a direction perpendicular to a medium conveying direction, a second optical sensor located on an upper part of the housing and on a side of the first optical sensor in the direction perpendicular to the medium conveying direction, and a processor to detect a folding of a medium based on the first signal or the second signal, and stop feeding of the medium by the feed roller in accordance with a detection result of the folding of the medium. The first light emitter emits first light toward a downstream side of the medium in the medium conveying direction, and the second light emitter emits second light toward an upstream side of the medium in the medium conveying direction.