Abstract: An image forming apparatus is provided which includes a first paper cassette provided in a lower portion of a main body of the image forming apparatus for housing recording papers therein and for feeding the recording papers to the main body through a first paper feeding path, and a second cassette provided below the first paper cassette for housing recording papers therein. At least a part housing the recording papers of the first paper cassette is capable of being pulled out in a pulling out direction which is in a feeding direction of the recording papers from the first cassette, and at least a part housing the recording papers of the second paper cassette is capable of being pulled out in the same pulling out direction of the first paper cassette.

Abstract: A developing agent replenishing apparatus includes a developing agent receiving port for receiving a developing agent from a replenishment cartridge which stores developing agent when the cartridge is mounted and a conveyor for conveying the developing agent received in the receiving port to a developing device. The developer agent receiving port has a receiving opening and the replenishment cartridge has a replenishment opening. Cylindrical expandable covers are provided at the receiving and replenishment openings for opening or closing these openings.

Abstract: A revolution control for a sun and planetary gear system including supporting members for the planetary gears which are revolvable around the same gear and a cam mechanism engaging a portion of the supporting member. The cam mechanism includes a cam shaft carrying a plurality of cams and there is a driving gear engaging the cam shaft. Also, two transmission gear trains present permit the driving gears to operate in either direction while still driving the toner replenishers in the same direction.

Abstract: The image forming apparatus includes: a developing device to develop an image by using developer; a developer container portion to supply the developer to the developing device; a developer cartridge which is attachable to or detachable from the developer container portion; and a driving means to rotate the developer cartridge. The developer cartridge further includes the following: a) a cartridge main body having a shape which facilitates movement of the developer toward a developer supply port by being rotated around a rotation axis by the driving means; b) a developer supply portion having the developer supply port to supply the developer to the image forming apparatus; and c) an opening/closing covering member to open and close the developer supply port.

Abstract: A toner cartridge in use with an image forming apparatus such as a printer. The toner cartridge includes a cylindrical container for accommodating toner, and the cylindrical container further includes; an opening at one side for discharging the toner accommodated in the cylindrical container; an spiral protrusion, provided on an inner circumferential surface of the cylindrical container, for conveying the toner toward the opening in the cylindrical container and for discharging the toner from the opening to outside the cylindrical container when the cylindrical container is rotated on an axis by a driver of the image forming apparatus; and a scoop, attached to the opening, for scooping the toner so that the spiral protrusion discharges the toner from the opening when the opening is at a position upper than a horizontal line extended through the axis.

Abstract: A developing unit driving mechanism in use with a color image forming apparatus. The mechanism includes: a photoreceptor drum for holding plural color toner images which are developed from a latent image; plural developing units, disposed around the photoreceptor, each for developing the latent image; a driving motor, rotatable in the normal direction and the reverse direction, for driving the plural developing units; a planetary gear mechanism, including a sun gear and a planetary gear, for transmitting a driving force of the driving motor from the driving motor to a set of driven gears; and the set of driven gears, each for transmitting the driving force of the driving motor from the planetary gear mechanism to one of the plural developing units.

Abstract: In a color image forming apparatus, an image retainer, a charger, a plurality of developing devices and a cleaner are made in one unit. The unit is dismountably supported in a housing so that the unit can be moved out from a first position at which the unit is set in the housing to a second position at which jam disposition is conducted. When the unit means is placed at the second position, a part of the apparatus is used to cover the image retaining surface at the transfer section.

Abstract: A color image forming machine includes a plurality of exposure units for irradiating an image carrier movable in a secondary scanning direction of the exposure units by primary scanning beams, at a plurality of irradiation positions to form latent images, a plurality of charging units for charging the image carrier corresponding to the irradiation positions of the exposure units and a plurality of developing units to form toner images corresponding the latent images. The plurality of toner images are superimposed on the image carrier to obtain a multi-color or full-color images trough transferring and fixing. A light-reflective registration mark is provided to a non-image area on one side of the image carrier. Employing at least two exposure units, irradiation by each primary scanning beam is conducted to the light-reflective registration mark moving in the secondary scanning direction.

Abstract: A driving device for a rotational photoreceptor drum for use in an image forming machine, in which a rotational drive from a motor is supplied through a gear train to the axial shaft of the drum. The shaft is connected to the drum only at the side farthest from the gear train. An inertia member is provided within the drum. A rotational member having a rotational resistance is brought in contact with a non-image region of the drum.

Abstract: An exposure device includes a polygon mirror to scan a photoreceptors with a plurality of laser beams to write plural color component latent images. The polygon mirror receives two laser beams at its two mirrors which are arranged diagonal to each other and reflects the two laser beams in the opposite directions to each other so that a first laser beam scans from the first side to the second side of the photoreceptor. On the photoreceptor are provided sensors to output first and second position signals independently when the first and second laser beams pass respectively the reference position mark disposed at one side on the photoreceptor.

Abstract: An image forming apparatus for forming a toner image on a peripheral surface of an image carrying drum and transferring the toner image onto a recording paper. The image forming apparatus comprises a conveyor to convey the recording paper, a register roller to feed the same to the conveyor, transfer unit for transfering the toner image and a pre-charging unit for charging the recording paper before the transferring. A controller of the image forming apparatus controls operation timings of the above units of the image forming apparatus and forms a blank area in the leading portion of the recording paper where no image is formed and no transfer operation is performed to the recording paper by the transfer unit.

Abstract: The invention provides an image forming apparatus having a transfer device. The transfer device includes a plurality of rollers, a belt and a cam. The belt is rotatable around the plurality of rollers so as to convey a recording sheet thereon. The transfer device is adapted to be pivotable around a pivot axis thereof. The cam pivots the transfer device so as to bring the belt in contact with and out of an imaging surface of a photoreceptor. In the device there is further provided a spring for supporting the transfer device to reduce the weight loaded onto said cam member.

Abstract: A transfer belt unit for conveying a recording sheet on a conveyor thereof and transferring a toner image from the surface of an image carrying drum to the recording sheet by electrostatic charging of the recording sheet and the conveyor belt by a corona discharger located on the rear side of the conveyor belt at a contact location of the image carrying drum and the conveyor belt. The transfer belt unit is provided with a preliminary corona discharger located in the wedge shaped space between the surfaces of the conveyor belt and the image carrying drum for charging the conveyor belt and the recording sheet by corona discharging to attract the recording sheet to the surface of the conveyor belt by electrostatic force. The preliminary discharger is composed of an electrode for corona discharging and a shield plate with an opening for restricting a discharging zone from the electrode to the recording sheet.

Abstract: The invention provides an apparatus for transferring a toner image from a photoreceptor to a recording sheet. The apparatus includes a plurality of rollers and a belt stretched around the plurality of rollers. The belt is adapted to come in contact with the photoreceptor at a transfer area so that a recording sheet is conveyed on the belt and brought in contact with the image surface at the transfer area and that the toner image is transferred onto the recording sheet. The apparatus further includes a conductive member, disposed so as to come in contact with the belt on one of the plurality of rollers which is positioned upstream in conveying direction than the transfer area, for charging the recording sheet conveyed on the belt.

Abstract: A developing device for use in an image recording apparatus, comprising: a developer stirrer which stirs toner and carrier in order to prepare the compostion of developer; a developer supplier which supplies the developer prepared by the developer stirrer; a developer holder which attracts the developer supplied by the developer supplier onto its surface, conveys the developer to the development region; a height regulator which regulates the layer thickness of the developer attracted onto the surface of the developer holder; a developer remover which removes the residual developer from the surface of the developer holder after development; a magnetic conveyor which conveys the developer removed from the developer holder to the region of the developer stirrer; and a mechanical conveyor which is placed in the region between the magnetic conveyor and the developer stirrer, which removes the developer attracted onto the surface of the magnetic conveyor, and moves the removed developer toward the region between th

Abstract: The present invention provides an optical correction device capable of correcting an exposure distribution so as to be flat at an image receiving surface such as a photoreceptor of copying machine, in spite of varying a projection magnification of original image on the image receiving surface. Additionally, the optical correction device can correct an exposure amount on the image receiving surface so as to be substantially same level throughout all available magnifications.

Abstract: An image forming apparatus with a magnification changing mechanism for an optical system wherein a first carriage carrying a lamp and a mirror for scanning an image of a document, a second carriage adapted to run in the same direction but at a half speed of the first carriage and carrying a V-mirror, and a lens for projecting the image of the document are provided. A V-mirror position changing device includes a block carriage disposed at an end of a closed loop wire for driving the first and second carriages, and a stationary block disposed on a body frame in a manner to correspond to adjoining blocks disposed on the block carriage. The wire is made to run on the blocks of the block carriage and the stationary block, and the terminal end of the wire is fixed on the block carriage.

Abstract: An exposure optical apparatus with two sets of wire pulleys disposed on both sides of a carriage for optical scanning of a document, the wire pulleys working for drive and control of the carriage, wherein two sets of fixed pulleys are provided on an apparatus fixed zone and laid on corresponding ends of the wire pulleys to a common wire, and a stopper member for determining an initial position of the carriage is provided on the apparatus fixed zone, thereby setting an initial posture of the carriage. The wires of both the wire pulleys are constituted of a common single wire, two sets of moving pulleys are provided on both sides of the document board carriage, and the wires are laid symmetrically on an axis of the center of the direction in which the document board carriage moves.

Abstract: The slit exposure optical system for a copying machine generally includes two mirror-carrying movable tables of which one is driven at half the speed of the other. Normally each table is driven from one and the same end which means that the other end of each table must follow. If such following is not precise, aberrations in the optical system result. The present invention provides means for interconnecting the nondriver ends of the tables in such a manner that the movement of the nondriver ends will precisely follow the movement of the driver ends and aberrations are thereby avoided.