Abstract: A sheet conveyance device correcting skew of a sheet being conveyed includes: a rotational shaft extending perpendicularly to a sheet conveyance direction; conveyance rollers disposed at predefined intervals and into which the rotational shaft is inserted; gate members being coaxial with the conveyance rollers and disposed between the conveyance rollers along the rotational shaft, the gate members each having an arc-shaped part partially surrounding the rotational shaft and a stopper protruding radially outwards from the arc-shaped part; and a mounting plate elongated along the rotational shaft and being supported rotatably around the rotational shaft and holding the gate members in a same orientation. After the sheet abuts against at least one of the stoppers, the stoppers are pushed out of the conveyance path by the sheet. When the stoppers are positioned on the conveyance path, openings of the arc-shaped parts face toward a downstream side in the conveyance direction.

Abstract: A sheet conveyance device correcting skew of a sheet being conveyed includes: a rotational shaft extending perpendicularly to a sheet conveyance direction; conveyance rollers disposed at predefined intervals and into which the rotational shaft is inserted; gate members being coaxial with the conveyance rollers and disposed between the conveyance rollers along the rotational shaft, the gate members each having an arc-shaped part partially surrounding the rotational shaft and a stopper protruding radially outwards from the arc-shaped part; and a mounting plate elongated along the rotational shaft and being supported rotatably around the rotational shaft and holding the gate members in a same orientation. After the sheet abuts against at least one of the stoppers, the stoppers are pushed out of the conveyance path by the sheet. When the stoppers are positioned on the conveyance path, openings of the arc-shaped parts face toward a downstream side in the conveyance direction.

Abstract: Provided is an image formation apparatus having a paper tray which is removably provided to an apparatus main body, in which sheets are loaded on a lifting plate, and from which the sheets on the lifting plate are fed by a paper feeding device, and the apparatus includes a holder that holds the lifting plate at a position higher than a lowest position when the paper tray is pulled out of the apparatus main body and the sheets are loaded on the lifting plate, wherein the holding by the holder is canceled to make the lifting plate go down to the lowest position before an operation of inserting the paper tray into the apparatus main body is completed.

Abstract: An air flow sensor includes a case, a to-be-detected object, and a detector. The case includes an intake port and an exit port through which air is to flow. The to-be-detected object is located at a first position in the case when the air flowing from the intake port to the exit port has lower than a predetermined level of pressure, and is movable from the first position receiving the air when the air has equal to or higher than the predetermined level of pressure. The detector is disposed outside the case and is configured to detect a movement of the to-be-detected object and output an electrical signal.

Abstract: An electrical machine includes an exhaust fan and an exhaust port on which an optional device is mounted. The optional device includes a duct, an electric fan, and an air flow sensor. Through the duct, an exhaust gas from the exhaust port is guided. The electric fan draws in the exhaust gas flowing through the duct and discharges the exhaust gas into an atmosphere. The air flow sensor detects presence or absence of the exhaust gas flowing from the electrical machine. The air flow sensor includes an air path partitioned from an inside of the duct by a partition wall. The air path includes an exhaust gas and an exit port. The exhaust gas intake port includes an opening facing the exhaust gas. The exit port communicates with the atmosphere at a position outside the duct.

Abstract: An air flow sensor includes a case, a to-be-detected object, and a detector. The case includes an intake port and an exit port through which air is to flow. The to-be-detected object is located at a first position in the case when the air flowing from the intake port to the exit port has lower than a predetermined level of pressure, and is movable from the first position receiving the air when the air has equal to or higher than the predetermined level of pressure. The detector is disposed outside the case and is configured to detect a movement of the to-be-detected object and output an electrical signal.

Abstract: An optional device is for an electrical machine. The electrical machine includes an exhaust fan and an exhaust port on which the optional device is mounted. The optional device includes a duct, an electric fan, and an air flow sensor. Through the duct, an exhaust gas from the exhaust port is guided. The electric fan draws in the exhaust gas flowing through the duct and discharges the exhaust gas into an atmosphere. The air flow sensor detects presence or absence of the exhaust gas flowing from the electrical machine. The air flow sensor includes an air path partitioned from an inside of the duct by a partition wall. The air path includes an exhaust gas and an exit port. The exhaust gas intake port includes an opening facing the exhaust gas. The exit port communicates with the atmosphere at a position outside the duct.