Abstract: An open/close assembly, having a first housing with an aperture; a second housing being openable and closable to the first housing; a first protrusion arranged in the second housing and movable between a first position protruding from the second housing to be inserted in the aperture and a second position being more inward than the first position; a spring arranged in the second housing and configured to urge the first protrusion toward the second position; a sensor arranged in the first housing and configured to detect the first protrusion inserted in the aperture; and an actuator with a surface configured to move the first protrusion to the first position when the second housing is being closed and to move the first protrusion to the second position when the second housing is being opened, is provided.

Abstract: A developing device including: a housing; a developing roller including a roller main body having a recess portion recessed inwards in an axis line direction, the recess portion including, a first surface extending in the axis line direction, and a second surface extending from an inner end portion of the first surface towards a direction intersecting with the axis line direction; and a seal member arranged between the housing and the roller main body, wherein, in the axis line direction, the second surface is positioned within a range in which the seal member is arranged, and wherein, in the axis line direction, a distance from an inner end portion of the seal member to the second surface is larger than a length of a part at which the seal member and the first surface overlap with each other.

Abstract: A printer comprises an ink-jet head, and a control unit which has a judgment pattern printing control section. When a judgment pattern is printed, the judgment pattern printing control section allows the discharge of ink droplets of a second color to an area on which ink droplets of a first color are to be landed, before discharging the ink droplets of the first color having a small color difference with respect to a color of a medium. Accordingly, the ink discharge malfunction is reliably judged for the nozzle irrelevant to the color of the recording medium and the color of the ink discharged from the ink-jet head.

Abstract: A thermistor is disposed confronting a surface of a heat roller on a downstream side in a rotational direction of a heat roller from a contact position between the heat roller and a pressure roller. Side guide members are provided on both sides of the thermistor and spaced away from the thermistor in the axial direction of the heat roller, and a regulating guide member is disposed connecting the side guide members on the downstream side in the rotational direction of the heat roller. In addition, a separation plate for separating a sheet of paper is provided at a predetermined space from the surface of the heat roller between the contact position and the thermistor in the rotational direction.