An edge detection apparatus for detecting an edge of a recording medium to be conveyed includes a light source, a plurality of photoelectric conversion element pixels, and a detection unit. The light source irradiates the recording medium with light. The plurality of photoelectric conversion element pixels are placed in a direction orthogonal to a conveyance direction of the recording medium and convert light reflected by the recording medium into an electrical signal. The detection unit detects the edge of the recording medium on the basis of a plurality of electrical signals that constitute an n-th (n≧1) electrical signal group obtained by dividing the plurality of electrical signals corresponding one-to-one to the plurality of photoelectric conversion element pixels, and a specified number of the electrical signals counted from a top of the plurality of electrical signals that constitute an n+1st electrical signal group.

An image forming apparatus includes a detection unit that detects a user of the image forming apparatus, a power supply control unit that, when a person approaching the image forming apparatus is detected by the detection unit when the image forming apparatus is in a power saving state where power supply to a function unit included in the image forming apparatus is stopped, activates the function unit while maintaining the display unit in a non-display state, and a display control unit that, when the user of the image forming apparatus instructs the display unit to present display after power is supplied to the function unit by the power supply control unit, changes the display unit to a display state.

A cartridge drive gear assembly for holding a drum coupling includes a drive gear having an outer surface and an inner surface, the inner surface including inner projections which extend into the interior of the drive gear and includes at least two voids disposed on opposing sides of the inner projections, and at least one slot disposed in the inner surface.

An image forming apparatus according to an embodiment includes a first image forming unit that forms a transparent toner image and a second image forming unit that forms a color toner image. The transparent toner image and the color toner image are transferred onto an intermediate transfer belt. A secondary transfer unit transfers the toner images from the intermediate transfer belt to a recording medium. A control unit controls the first image forming unit and the second image forming unit so that the transparent toner image is formed before the color toner image is formed when the recording medium is a specialty paper having an adhesive.

A medium identification device identifies a type of a recording medium used for image formation. The medium identification device includes: a two-dimensional image sensor that captures an image of the recording medium; and an identifying unit that obtains a glossiness evaluation value indicating glossiness of the recording medium, a surface roughness evaluation value indicating surface roughness of the recording medium, and a coloring evaluation value indicating coloring of the recording medium, using image data of a specular reflection region reflecting specular reflection light from the recording medium and image data of a diffused reflection region reflecting diffused reflection light from the recording medium, the regions being in the image of the recording medium, and identifies the type of the recording medium by combining determination using the glossiness evaluation value, determination using the surface roughness evaluation value, and determination using the coloring evaluation value.

Provided is a power supply unit that includes a power factor correction circuit, a synchronizing signal generator, an alternating-current signal generator. The power factor correction circuit is configured to generate, based on a first alternating-current signal, a direct-current signal. The synchronizing signal generator is configured to generate, based on the first alternating-current signal, a synchronizing signal that is in synchronization with the first alternating-current signal. The alternating-current signal generator includes a switching section, and is configured to generate, based on the direct-current signal, a second alternating-current signal. The switching section is configured to perform, based on the synchronizing signal, a switching operation. The second alternating-current signal has a variable effective voltage value.

A sheet feeder is provided. The sheet feeder includes a roller to feed a sheet, a motor to rotate the roller, and a motor controller to control rotation of the motor by a feedback control. The motor controller detects a condition of the sheet based on a value acquired in the feedback control at the time a load is applied from the sheet to the roller, while performing a stop control to stop the roller at a designated stop position. The stop control is performed after the motor is rotated in a direction opposite to a direction of feed of the sheet.

An image forming apparatus and a voltage supply method are provided which are capable of fulfilling a stable bias supply to a fittable-and-removable image forming unit and moreover offering improved accessibility to the board. The image forming apparatus includes a lower casing, an image forming unit, a high-voltage board, and a left interconnecting unit. The high-voltage board has a plurality of electric components and output terminals in its upper surface portion above the image forming unit. When a top cover of the lower casing is removed off, the high-voltage board is exposed. The left interconnecting unit is fitted to a side end portion of the high-voltage board and electrically connected to the output terminals of the high-voltage board. The left interconnecting unit supplies a voltage to the image forming unit via a side portion of the high-voltage board.

An image-forming apparatus includes: a casing; a first sheet tray provided in a bottom portion of the casing; an image-forming unit configured to form an image on a sheet supplied from a sheet accommodation portion of the first sheet tray; a sheet supplying path; a first conveying path; and a shutter. The sheet supplying path is configured to provide communication between the sheet accommodation portion and the image-forming unit. The first conveying path is provided in one of the casing and the first sheet tray, and has one end formed with an opening and another end configured to communicate with the sheet supplying path, the opening being open downward. The shutter is movable between a closing position closing the first conveying path and an opening position opening the first conveying path.

A sheet humidification apparatus includes a pair of humidification rollers, a water supply section, and a control section configured to control humidification of the humidification rollers and water supply of the water supply section, and the control section refers to a contacting period between the humidification rollers to control the water supply such that a second water supply amount from the water supply section to the second humidification member is smaller than a first water supply amount from the water supply section to the first humidification member.