Abstract: An image forming apparatus having an image forming unit that forms an image on an image bearing member, and a mainframe that firmly supports and positions the image bearing member and the image forming unit. The main frame has two side walls which are opposed to each other and substantially support the image bearing member and the image forming unit, a bottom wall to which the two side walls are rigidly connected, and a stay which is rigidly connected to the two side walls and is spaced away from the bottom wall. The bottom wall and the stay have a box type structure with an inner hollow room.

Abstract: A transmission mechanism for transmitting rotation of a driving source in a main body to an object mounted on the main body for receiving the rotation, the transmission mechanism comprising a plurality of couplings provided at different positions along an axial direction of a rotating axis; wherein each of the couplings comprises, a male coupling member having a plurality of protrusions provided at an identical internal on an outer circumferential surface of the rotating axis; and a female coupling member having a plurality of protrusions for engaging with the male coupling's protrusions.

Abstract: A color image forming apparatus is provided wherein toner images formed on a plurality of image carriers are primarily transferred onto an intermediate transfer object, and then, are secondarily transferred onto a recording sheet. The color image-forming apparatus includes an intermediate transfer member, a longitudinal direction of which is arranged in substantially a vertical direction, and onto which toner images formed on image carriers are sequentially transferred in such a manner that the toner images overlap relative to each other so as to form a color toner image on the intermediate transfer member. In addition, a transferring device is provided to transfer the color toner image formed on the intermediate transfer member onto a transfer sheet. The intermediate transfer member and the image carriers are integrated into a rack, and the rack is drawable in substantially a horizontal direction with respect to a mainframe of the color image-forming apparatus.

Abstract: The present invention concerns a color image forming apparatus wherein toner images formed on a plurality of image carriers are primarily transferred onto an intermediate transfer object, and then, are secondarily transferred onto a recording sheet.

Abstract: The present invention concerns a color image forming apparatus wherein toner images formed on a plurality of image carriers are primarily transferred onto an intermediate transfer object, and then, are secondarily transferred onto a recording sheet.

Abstract: An image forming apparatus comprises, an image forming unit that forms an image on an image bearing member, and a mainframe that firmly supports and positions the image bearing member and the image forming unit, the main frame comprises two side walls which are opposed each other and substantially support the image bearing member and the image forming unit, a bottom wall to which the two side walls are rigidly connected, and at least one stay which is rigidly connected to the two side walls in the manner of leaving space from the bottom wall, wherein each of the bottom wall and the at least one stay has a box type structure having an inner hollow room.

Abstract: An image forming apparatus includes an image-bearing member, an image forming device for forming an image on the image-bearing member, a side section to substantially support at least one of the image-bearing member and the image forming device and a bottom section to support and position the side section. The bottom section includes an upper surface member, a lower surface member and a side surface member which connects each side of the upper surface member and each side of the lower surface member.

Abstract: The present invention concerns a color image forming apparatus wherein toner images formed on a plurality of image carriers are primarily transferred onto an intermediate transfer object, and then, are secondarily transferred onto a recording sheet.

Abstract: A transmission mechanism for transmitting rotation of a driving source in a main body to an object mounted on the main body for receiving the rotation, the transmission mechanism comprising a plurality of couplings provided at different positions along an axial direction of a rotating axis; wherein each of the couplings comprises, a male coupling member having a plurality of convex elements provided at an identical internal on an outer circumferential surface of the rotating axis; and a female coupling member having a plurality of concave elements for engaging with the convex elements.

Abstract: A process cartridge for use in an image forming apparatus, includes: a photoreceptor for bearing an image thereon; a processing member for image formation; and a heat roller included in a heat fixing device for fixing a developed image formed on a recording sheet. The photoreceptor, the processing member and the heat roller are integrally provided on the process cartridge which is attachable to the image forming apparatus.

Abstract: An optical system of a photodrawing machine for photo-copying apertures onto light sensitive material minimizes undesirable effects of variations in projecting magnification and in illumination of the image forming plane. Exposure control is effected by a diaphragm mechanism which includes an optical fiber.