The present invention has a purpose of providing a paper sensor device capable of measuring measurement light with high precision to detect a paper property with high precision without adding to printing time. A paper sensor device includes: a light-emitter that emits emission light; a photodetector that receives emission light in a first state and receives light transmitted through a sheet of paper in a second state; and a transporting unit that transports the sheet of paper. The transporting unit, including a transport roller and a paper guide, transports the sheet of paper while sandwiching the sheet of paper between the transport roller and the paper guide. The light-emitter is embedded in the transport roller. The photodetector is disposed on the back of the paper guide to receive light via a window.

A sensor (10) is used for detecting at least one edge of at least one product web (1) running in a run direction (2). The sensor (10) has active elements (11), which are arranged adjacent to one another and are formed by transmitters (12) and receivers (13). In this case, the transmitters (12) can emit waves (14) which are received by the receivers (13). The product web (1) is provided for influencing the waves (14) in the radiation path between the transmitters (12) and receivers (13). In this case, a first (21, 31) and second (22, 32) of the active elements (11) are adjacent and have a mutual first spacing (41). The second (22, 32) and a third (23, 33) of the active elements (11) are also adjacent to one another and have a second spacing (42), which corresponds to at least 1.2 times the first spacing (41).

An image forming apparatus includes an image forming unit forming images on a first sheet and a second sheet having a higher stiffness than the first sheet, a discharge rotary member pair, and a sheet supporting unit to support the first and second sheets discharged through the discharge rotary member pair. In addition, an abutment surface abuts against upstream ends of the first and second sheets supported on the sheet supporting unit, and an elevation unit moves the sheet supporting unit up and down. A control unit, in a state where no sheet is supported on the sheet supporting unit, executes a first discharge mode of controlling the elevation unit to position the sheet supporting unit at a first position before the discharge rotary member pair starts discharging the first sheet, and a second discharge mode of controlling the elevation unit to position the sheet supporting unit at a second position lower than the first position.

A printing apparatus includes a mark sensor, a moving section, a web edge sensor, and a printer control section. The moving section can move the mark sensor in a direction intersecting a transport direction of a sheet, or in a width direction. The web edge sensor can detect a location of an edge of the sheet. The printer control section controls the moving section to compensate for a location of the mark sensor, on the basis of a detection result from the web edge sensor which indicates the location of the edge of the sheet.

A sheet binding processing apparatus including a crimp binding member that performs binding processing on a predetermined region of a sheet by sandwiching and pressing the sheet between an upper tooth and a lower tooth meshing with each other, and a detection unit that detects a state of the predetermined region of the sheet to be bound by the crimp binding member. If the detection unit detects that the predetermined region is not capable of binding, the binding processing on the predetermined region is prohibited.

A contact member swingably moves about a swing axis to contact a recording medium stacked on a medium tray, and shifts to different states depending on volume of medium. A controller performs: a detection process of detecting the stacked volume based on signals of M times outputted from the sensor, the M times being a number of times that is larger than or equal to two times; a stack determination process of determining whether the recording medium is stacked on the medium tray based on signals of N times, the signals of N times being a part of the signals of the M times outputted from the sensor, the N times being a number of times that is smaller than M; and a sheet feeding process of controlling the feed roller to feed the recording medium, in response to determining that the recording medium is stacked on the medium tray.

An image forming apparatus includes a first unit, a second unit fixed to the first unit at a portion upstream of the first unit in a conveyance direction in which the sheet is conveyed, and an electric board. In the image forming apparatus, a disposition of the electric board is restricted by the first unit and the second unit.

A contact member swingably moves about a swing axis to contact a recording medium stacked on a medium tray, and shifts to different states depending on volume of medium. A controller performs: a detection process of detecting the stacked volume based on signals of M times outputted from the sensor, the M times being a number of times that is larger than or equal to two times; a stack determination process of determining whether the recording medium is stacked on the medium tray based on signals of N times, the signals of N times being a part of the signals of the M times outputted from the sensor, the N times being a number of times that is smaller than M; and a sheet feeding process of controlling the feed roller to feed the recording medium, in response to determining that the recording medium is stacked on the medium tray.

An image forming apparatus, including (1) a medium holding unit that holds a recording medium; (2) a guide member configured to be movable, that sets a medium path of the recording medium fed from the medium holding unit as a predetermined path by being locked in a predetermined position, and that is unlocked by a tension of the recording medium; (3) a first conveyance member that is arranged downstream of the medium path of the guide member, and conveys the recording medium; and (4) an image forming unit that forms an image to the recording medium conveyed by the first conveyance member.

A recording medium conveyance device includes a storage, a conveyer that conveys a conveyed object, an ultrasonic sensor that outputs a value indicating an attenuation amount of an ultrasonic wave caused by the conveyed object, and a hardware processor. The hardware processor executes a type detection process of detecting a type of the conveyed object based on output of the ultrasonic sensor and storing the type in the storage and an overlay detection process of detecting whether the conveyed object is in an overlay state in which a gap is present based on output of the ultrasonic sensor, and switches to either one of the type detection process and the overlay detection process. The hardware processor executes the type detection process when the type is not stored in the storage and executes the overlay detection process when the type is stored in the storage.