Abstract: A device for attaching and detaching a mounting board unit with respect to a device body in a substantially vertical posture includes a controller base which has a detachable mounting board fixed thereto and a guide portion engaging a guide rail provided on the device body. The guide portion guides the controller base when the mounting board unit is attached to and detached from the device body. Mounting boards having different shapes can be mounted on the unit of the same construction, and even a mounting board on which a heavy device such as a hard disk is mounted can be easily attached to and detached from the device body in a vertically arranged condition.

Abstract: An image forming apparatus having a pressing unit for pressing a fixing unit so that the fixing unit is secured to the apparatus body by the pressing force of the pressing unit. A projection portion on the fixing unit and an insertion slit in the apparatus body also secure the fixing unit, and thus, screws for securing the fixing unit to the apparatus body can be omitted and the fixing unit can easily be attached/detached. A discharge cover is rotatably mounted to the apparatus body and the fixing unit is inserted through an opening portion created when the discharge cover is opened.

Abstract: A fixing apparatus having a heating member maintained at a predetermined fixing temperature and an electric supply device for supplying an electric current to the heating member, wherein the electric supply device supplies an electric current at a second duty cycle larger than a first duty cycle after an electric current is supplied at the first duty cycle from the time the supply of the electric current is started to the heating member until a fixing temperature is reached.

Abstract: A sheet feeding apparatus comprising a sheet accommodator for accommodating sheets and movable in a predetermined direction from a sheet-feeding position; a feeding device for feeding sheets accommodated in said sheet accommodator held at said sheet-feeding position in said direction; a friction member for permitting feeding of only one of sheets fed out from said feeding device while blocking the feeding of the remaining sheets; and a support for supporting said friction member such that said friction member can be moved to a first position for separating a sheet, and to a second position for permitting movement of said sheet accommodator in said direction.

Abstract: The present invention provides a sheet supply apparatus comprising a sheet containing device for containing a plurality of sheets, a sheet positioning member provided in the sheet containing device to position the sheets in a widthwise direction thereof by abutting against a side edge of the contained sheets, and a supply device for feeding out the sheets positioned by the sheet positioning member. Wherein the sheet positioning member is previously inclined at a predetermined angle toward a direction opposite to a direction that the sheet positioning member may be inclined by the deflection of the sheet containing device due to the weight of the sheets contained in the sheet containing device.

Abstract: The present invention provides a sheet feeding apparatus having a sheet supporting tray removably mountable within the sheet feeding apparatus and adapted to stack and support sheets, a regulating device provided on the sheet supporting tray and adapted to regulate and position lateral edges of the sheets stacked in the sheet supporting tray, an urging mechanism for urging with a predetermined urging force the sheets stacked in the sheet supporting tray against the regulating device, and an urging force adjusting mechanism for adjusting the urging mechanism so that the urging mechanism can urge the sheets against the regulating device with greater force during insertion of the sheet supporting tray into the sheet feeding apparatus.

Abstract: The present invention provides a sheet feeding apparatus comprising: a first sheet accommodating means shiftable in a predetermined position from a sheet supply position for supplying a sheet, a first sheet supply means for feeding out the sheet from the first sheet accommodating means positioned in the sheet supply position, a feeding means for feeding the sheet fed out by the first sheet supply means, a second sheet accommodating means for accommodating sheets, a second sheet supply means for feeding out the sheet from the second sheet accommodating means, a guide means movable between a first position intersecting a moving path of the first sheet accommodating means and where guiding the sheet fed out by the second sheet supply means to the feeding means and a second position where not guiding the sheet, a detecting means for detecting the passage of the sheet through the guide means and for emitting a detection signal, and an inhibiting means for inhibiting the movement of the first sheet accommodating me

Abstract: An image forming apparatus includes a main assembly and a process cartridge. The main assembly contains and retains an electrophotographic photosensitive member, and therefore, the photosensitive member is not contained in the process cartridge. The process cartridge contains an electric charger, a developing device and/or cleaning device. The process cartridge is detachably mountable into the main assembly.

Abstract: An image forming apparatus provided with a positioning mechanism for positioning a process cartridge in the main assembly. The process cartridge is detachably mountable into the main assembly. The main assembly includes a bottom frame and a top frame which is capable of taking a closing position and an opening position. The process cartridge is loaded into the top frame or bottom frame. Prior to the start of image formation, the process cartridge is correctly positioned with respect to the bottom frame. The bottom frame contains the major part of the optical system, whereby the accurate relative position can be accomplished with an optical system of the cartridge.