An image forming apparatus includes first and second light emitting units, a light receiving unit for receiving light of the first light emitting unit when it is reflected, and receiving light of the second light emitting unit when it is not reflected, to output a signal of a predetermined level, and a control unit for starting light emission of the first light emitting unit before a front end of a paper sheet reaches an area, stopping light emission of the first light emitting unit while starting light emission of the second light emitting unit before a rear end of the paper sheet passes the area, and detecting a length of the paper sheet based on time after the output signal becomes a predetermined level during light emission of the first light emitting unit until the output signal becomes the predetermined level during light emission of the second light emitting unit.

A detection unit includes a first contact member that comes into contact with a surface of a recording material and a second contact member that comes into contact with the other surface of the recording material, and the first contact member and the second contact member face each other and are capable of nipping the recording material. The first contact member and the second contact member are movable in a direction in which the first contact member and the second contact member nip the recording material. The first contact member and the second contact member are rotatable about an axial line that extends in a direction in which the recording material is conveyed.

A sheet type determining device including a guide that guides a sheet along a sheet conveyance path to a destination. The sheet conveyance path is between a first guide surface and a second guide surface facing each other across an interval. The sheet type determining device further includes a determiner that determines a sheet type when the sheet is in the sheet conveyance path, without having contact with the sheet in conveyance, and one or more regulators that regulate a displacement range of the sheet at a determining position, the displacement range being in a direction of the interval of the first and the second guide surfaces. Each of the regulators is a member that protrudes in an arc shape from the first or the second guide surface toward the guide surface opposite, and is spaced from the guide surface or another one of the regulators opposite.

A sheet stacking device includes a housing, a discharge tray, a lifting mechanism, a first upper surface detection part, a second upper surface detection part and a control part. The housing has a discharge port. On the discharge tray, the sheet discharged from the discharge port in a predetermined discharge direction is stacked. The lifting mechanism supports the discharge tray. The first upper surface detection part detects a first detected surface of the sheet on the discharge tray. The second upper surface detection part detects a second detected surface of the sheet on the discharge tray on a downstream side of the first detected surface in the sheet discharge direction. The control part controls the lifting mechanism based on a detection result of the first upper surface detection part and a detection result of the second upper surface detection part, and adjusts the discharge tray at a predetermined height.

Disclosed is a paper feeding device (10) comprising a storage surface (14) for a stack of papers (12), with a leading edge (14a), a trailing edge (14b), and a first and a second side edge (14c, 14d). The surface (14) is adapted to be moved vertically. The device further comprises a vacuum feeder (16) for feeding papers from their position on the storage surface (14) and imparting on an uppermost sheet of paper (12a) a horizontal displacement, and a blower arrangement (18, 20) adapted to provide a curtain of air separating the uppermost sheet of paper (12a) from the rest of the stack of papers. The device further comprises a sensor arrangement (22) arranged to determine where the upper paper sheets in the stack of papers (12) start to separate from the rest of the paper sheets, the sensor arrangement (22) comprising a plurality of infrared reflective sensors (22a).

A sheet transportation device includes a sheet loading table, a feeding unit that feeds a sheet placed on the sheet loading table, a first detection unit that is provided downstream of the feeding unit in a sheet transportation direction and that detects a position of a leading end of the sheet, a second detection unit that is provided upstream of the feeding unit in the sheet transportation direction and that detects a position of a leading end of a small-size sheet which is smaller than the sheet detected by the first detection unit, and a control unit that starts feeding the sheet based on a result of detection performed by any of the first detection unit or the second detection unit in accordance with a size of the sheet.

According to one embodiment, a paper sheet processing apparatus includes a conveyance device with a conveyor belt, and an inspection device configured to inspect a paper sheet conveyed by the conveyor belt. The inspection device includes an image detection device configured to capture an image of the paper sheet and the conveyor belt and obtain an image of the paper sheet and the conveyor belt, an image processing device configured to detect a degradation level of the conveyor belt based on an belt image of the conveyor belt, and a controller configured to transmit information encouraging replacement of the conveyor belt to a monitor.

A document transport device includes a placement portion, a slide member, a movable piece, and a detector. A document is to be placed on the placement portion. The slide member includes a document guide that contacts one lateral side of the document which is placed on the placement portion. The movable piece is provided to the slide member, and includes a shading pattern composed of plural patches that have plural densities corresponding to plural document sizes and having plural adjacent patch density differences that are different from each other. The detector detects a density of the shading pattern, and outputs an output signal for document size recognition.

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.

The medium detection unit is a component constituting an optical path of the detection light, and includes a first optical element disposed on an upper side of the medium transport path and a second optical element disposed on a lower side of the medium transport path so as to face the first optical element, the second optical element has a facing surface that faces the first optical element, the facing surface being located at a position that is not in contact with a medium nipped by both the first roller pair and the second roller pair, and a medium feeding direction by the first roller pair is a direction by which a leading edge of a medium fed out abuts a position upstream in the medium transport direction relative to a position where the detection light is received on the facing surface.