Abstract: In an image forming apparatus, a sheet that has been transported in a certain direction is selectively transported to one of first and second transport routes by a route changer mechanism. A first cover and a second cover are openably provided on a main body of the apparatus to respectively allow the first and second transport routes to be accessible to outside of the apparatus main body when set in an opened state. An operative mechanism is provided to open the first cover in association with opening of the second cover.

Abstract: A document feeder which has a document transportation path curved with a curvature radius such that a document original is reversed and fed therethrough to a document setting surface. The document feeder further includes a pair of rollers respectively disposed inside and outside of the curvature of the document transportation path in an opposed relation and adapted to hold the document original therebetween for guiding the document original to the document setting surface. The rollers abut against each other in a position upstream of the vertex of the curvature of the document transportation path with respect to a document transportation direction.

Abstract: A photosensitive drum unit for an electrostatographic printing apparatus is disclosed. The drum unit includes a drum tube formed with at least one opening at one axial end thereof. A flange member is configured to be inserted into the opening in the drum tube. The flange member is provided with a support hole into which a shaft pin is inserted for supporting the drum tube and flange member. An earth plate is formed with projections or claws that extend radially outward from a peripheral edge of the earth plate such that the projections contact with an inner peripheral surface of the drum tube. The earth plate is also formed with a pair of contact pieces extend axially away from the earth plate and also extend toward one another. The contact pieces are spaced apart from one another by a predetermined distance but are also configured to contact and engage a portion of the shaft pin.

Abstract: This invention is related to an image reading apparatus for use in a digital copy machine and a facsimile machine. The invention is made possible to obtain the simple flat average value of the white reference data used for a shading correction obtained with a photoelectric conversion elements arranged in a line by sensing the reflected light upon a white reference plate. The image reading apparatus comprises an n-bit memory for the white reference data and another n-bit memory for the black reference data and a reference data processing circuit for summing white reference data after 2.sup.m times of line readings on the white reference plate. The summation of the data is carried out with the use of an n+m bit memory region, consisting of an upper n bit section and a lower m bit section, that is made up with the n-bits of the n-bit memory of the white reference data and m-bits of the n-bit memory of the black reference data. Then after summation of 2.sup.

Abstract: A toner cartridge according to the present invention ensures easy replacement thereof and assuredly prevents a user from failing to claim its toner fall aperture. When a shutter is located in a position where the toner fall aperture is closed, a claw of a lock portion does not project outward. When the toner cartridge is inserted in an insertion direction, a right holding portion of the shutter abuts against an engagement side wall of an engagement portion, and prohibits the shutter from moving in the direction of the insertion so that the toner fall aperture is opened. When the toner cartridge is withdrawn, the lock portion of the claw is locked to a return portion provided on a side wall thereby to prohibit the shutter from moving in a direction opposite to the insertion direction. Thus, the shutter is slid in the insertion direction with respect to a flange to close the toner fall aperture.

Abstract: An image forming apparatus has an optical system, an image forming section and a paper conveying section provided in its main body. The main body includes a first portion containing the optical system and a second portion containing the image forming section and the paper conveying section below the first portion. A paper discharging section opening toward the front is provided between the first portion and the second portion. The first portion is shifted by a predetermined amount backward with the position where it is lined up to a second portion as a basis. It is easy to visually confirm whether or not there is a paper sheet in the paper discharging section below the first portion.

Abstract: A recycle document feeder according to the present invention includes a cover (251) covering a document discharge portion (30). The cover (251) is openably supported by a pivot shaft (256) between a pair of frames (255). A feed-back path (32) for guiding a document original onto a document placing plate is defined by a pair of guide members (257, 258) provided in an opposed relation. The upper guide member (258) is attached to the interior face of the cover (251). A switch claw (253) for switching the document traveling direction is attached to the pivot shaft (256) which supports the cover (251). Thus, there is no need for additionally providing a shaft for supporting the switch claw (253), thereby simplifying the construction of the document discharge portion (30).

Abstract: An image reading apparatus in which reference density data corresponding to a reference document having a predetermined reference density is stored in advance, while a plurality of gamma correction curves are also stored in advance. Light intensity data indicative of the intensity of light reflected from the reference document is subjected to a shading correction. One gamma correction curve is selected from the plurality of gamma correction curves in correspondence to a difference in output level between the reference density data and outputted density data obtained by converting the shading corrected light intensity data. Gradation of the outputted density data is adjusted based on the selected gamma correction curve.

Abstract: Auxiliary heating roller(s) employed in an electrostatographic fixing station are cleaned at low cost by the efficient use of the reverse side of a disposable cleaning web which conventionally has been discarded after using its one side alone. Cleaning web devices 15 and 16 are installed in top and bottom ends of a fixing station, wherein auxiliary heating rollers 5 and 6 ride respectively on a heating roller 3 and a pressure roller 4 of a fixing roller pair. The cleaning web devices 15 and 16 are configured therein to clean the fixing rollers initially, employing an obverse side A of a cleaning web 21 in the respective devices, which winds around turnaround rollers such that thereafter the reverse side B of the cleaning web 21 is employed to clean the surfaces of the auxiliary heating rollers 5 and 6.

Abstract: A sealing mechanism for preventing the leakage of powder from between a through-hole and a rotary shaft which is supported between one side wall of a container containing said powder and the other side wall thereof and of which one end protrudes outwardly beyond said through-hole formed in said one side wall. A circular flange is formed on the rotary shaft, and a seal ring member is fitted between the circular flange of the rotary shaft and said one side wall. A to-be-engaged groove is formed in one end of the rotary shaft. An input gear made of a synthetic resin is fitted to the one end of the rotary shaft, and an engaging projection that engages with said to-be-engaged portion is formed in a portion of the input gear that is fitted to the rotary shaft.

Abstract: A facsimile machine includes a machine housing; an upper guide member disposed above the machine housing and adapted to be movable between an operating position, in which a document transport path is formed, and an open position, in which the document transport path is opened; an operating panel mounted on the top of the upper guide member and provided with dial number call keys for calling previously stored dial numbers of destinations, and a function switching key for selecting from two alternative call dial numbers stored for each of the dial number call keys; and a key switching plate having openings through which the key heads of the dial number call keys are exposed with the key switching plate disposed on the operating panel so as to be invertible between a first position and a second position and adapted to move the function switching key in a switching manner upon the inversion thereof.

Abstract: This invention relates to a document transport device for use in an image forming apparatus. The document transport device has a first belt roller disposed above a document positioning member. A second belt roller is disposed away from the first belt roller in the document transport direction. An endless belt is wound around the first and second belt rollers. Plural presser rollers are arranged on a specified position between the first and second belt rollers to press the belt against a contact glass. The document transport device has a tension roller between the first belt roller and the presser roller closest thereto to apply a tension force to the belt so as to set the belt at the lowermost position of the tension roller below a common tangential line to the circumferences of the first belt roller and the presser roller and apart from the contact glass.

Abstract: An image forming apparatus which forms a toner image which is transferred onto a copy sheet includes a fixing unit having a heater for fixing the toner image onto the copy sheet at a predetermined fixing temperature. A cooling unit operates at a first cooling state for cooling the fixing unit. A mode selector is provided for setting a mode of the image forming apparatus to an energy saving mode in which heating operation by the heater is halted. A cooling controller suspends cooling operation of the cooling unit after a delay following a time when the image forming apparatus is set to the energy saving mode.

Abstract: This invention relates to a copy sheet guide structure for use in an image forming apparatus. Plural copy sheet guide structures constitute a transport path along which a copy sheet is to be transported. At least one guide structure has a pair of guide members formed into such a shape to form a one piece unit when engageably assembled to each other. With this arrangement, fastening means for constructing the guide structure is not necessary. Further, sheet guiding ability of the copy sheet guide structure can be improved because the guide members are assembled to each other with high positional accuracy.

Abstract: A facsimile machine with a plurality of cassettes which is capable of printing a transmission report including first data and second data on a printing sheet accommodated in the cassette where the first data being a result of the transmission and the second data being an image data of a transmitted data, said facsimile machine includes: a memory unit for storing the first data and the second data therein to be read out; an editing unit for reading out the first data and the second data from the memory unit and formulating a resultant data; a sheet size set unit for detecting and setting a size of printing sheet on which the resultant data is to be printed; a divider unit for dividing the resultant data into a plurality of block data according to the size set by the sheet size set unit; a judgment unit for judging whether the block data corresponding to the last page of report is solely the second data; and a print control unit for inhibiting printing of the second data on the last page of report when it is ju

Abstract: The present invention relates to an air suction type paper feeding device that includes at least one rib 5 formed on a paper supply table, the rib slightly lifting papers P such that the bottommost paper is less likely to be retained by static electricity. The invention also relates to a jogging plate disposed at a rear end of the paper supply table which has an inclined portion which urges the uppermost papers on the paper supply table towards an air supply means. The jogging plate is further formed with an arcuate portion which diverts air from the air supply means downward against a rear end portion of the paper on the paper supply table. The present invention further relates to a paper feeding belt 3 having air permeability disposed above stacked papers on the paper supply table. A vacuum manifold is disposed between portions of the feeding belt 3 to provide vacuum to lift papers. The vacuum manifold is formed with a plurality of suction ports a, b, c.

Abstract: The photosensitive material of the present invention is provided in contact with a developing roller and has a surface potential decay characteristic in which when the photosensitive material is charged to a surface potential of 800 V and is contacted with the developing roller to which a voltage (VR) is applied, the surface potential (VD) of the photosensitive material after contacting is represented by the formula (1):VD.gtoreq.800.times.EXP (0.00235.times.VR).By using this photosensitive material, a transverse black stripe in the tip of the transfer paper is prevented and it is possible to form an image having excellent image quality and image density.

Abstract: Disclosed is an electromagnetic clutch comprising a field member with an exciting coil member disposed therein; a shaft extending through the field member and the exciting coil member; a rotor member fixedly disposed on the shaft at a position opposing to the filed member; a drive mechanism rotatably provided on the shaft; a contact member provided on the drive mechanism on the side facing the rotor member; an elastic member disposed on the drive mechanism for biasing the contact member to the drive mechanism. The contact member is positioned to form a clearance of a first dimension G1 along the shaft between the surfaces of the contact member and the rotor member and the first dimension G1 is set to be smaller than a limit dimension G3. A deformation of the elastic member by the limit dimension along the axial direction results in the elastic limit.