Abstract: An electrophotographic image forming apparatus including a developing unit operable with a one- or two-ingredient type developer and a device for replenishing toner to the developing unit included in the apparatus are disclosed. A plurality of toner bottles are accommodated in the toner replenishing device, so that the toner is replenished from one toner bottle to the developing unit. A rotating mechanism causes all the toner bottles to rotate during toner replenishment. A device is provided for determining the frequency of use of the individual toner bottle. The toner discharged from each toner bottle is fed to a toner transport portion via a respective passageway.

Abstract: In a belt type fixing apparatus having a heat roller temperature sensor that detects the temperature of a heat roller that contains a heater for heating a fixing belt, and a fixing belt temperature sensor that is set to contact a pressure roller and indirectly detects the temperature of the fixing belt, the heater that heats the fixing belt is controlled in such a way that the temperature detected by the heat roller temperature sensor matches the target temperature of the heat roller that is set based on the temperature detected by the fixing belt temperature sensor.

Abstract: A charging or image transfer unit for use in an image formation process including the steps of charging, image formation exposure, image development, image transfer, image fixing and cleaning, for applying an electric field to the surface of an electrophotographic photoconductor by coming into contact therewith, and also for controlling surface properties of the electrophotographic photo-conductor. The unit includes an electric field application member applying the electric field to the surface of the electrophotographic photoconductor and a lubricity-imparting member for controlling a friction coefficient of the surface of the electrophotographic photoconductor wherein the electric field application member includes an electrophotoconductive material and a lubricity-imparting member includes a fluoroplastic material.

Abstract: A fuser hot roll for use in an electrophotographic process is disclosed. This roll is constructed such that the center portion of the roll's length has a greater thermal mass per unit length than each of the end portions of the roll's length. This can be accomplished either by constructing the center portion from a material which has a higher thermal capacity than the materials used for constructing the end portions, or constructing the center portion such that it is thicker than the end portions of the roll. The rolls of the present invention provide a simple way for regulating the fuser temperature such that it is uniform across the length of the hot roll, is uniform between the transitory (heat up) state and the steady state, and minimizes hot roll temperature overshoot during the transitory phase. The image fixing apparatus which incorporates this hot roll is also disclosed.

Abstract: A document scanner, including a document input tray for holding a compilation of documents in a predetermined sequence; a document output tray for receiving documents; an imaging station for scanning each one of said compilation of documents at predefined scanning rate; an imaging transport system for moving the documents received from said document input tray through said imaging station at a first velocity; an inverter, spaced a predetermined distance from said imaging transport system for moving selected documents of said compilation of documents back to said imaging transport system, said inverter having one mode of operation for moving selected documents to said imaging transport system so that a second side of said selected documents is scanned by said imaging station, said inverter having second mode of operation for moving selected documents to said imaging transport system so that said first side of said selected documents are rescanned by said imaging station.

Abstract: A developer supply container for supplying a developer for developing a latent image formed on a photosensitive member is provided, wherein the container is inserted into a developer accommodating container which is provided in a process cartridge, through an entrance opening, and the developer is supplied while the container is in the developer accommodating container, and wherein the entrance opening is covered by an openable cover, and wherein when the developer supply container is mounted and demounted, the openable cover is opened, the developer accommodating container being usable with an electrophotographic image forming apparatus.

Abstract: Electrostatic printing machines require different types of paper with different width and thickness. In relation to the paper thickness and width is a phenomenon called the End Leakage Current Effect whereby highly positive voltage can be found in the non-paper contact area of a photoreceptor surface after the transfer stage. The paper transfer stage is when the paper touches the photoreceptor and an image is transferred onto the paper. This effect can result in cleaning failure and potential non-uniformity on the photoreceptor surface. The extent of the end leakage current effect depends on the thickness and width of the paper to which the image is being transferred. Adjusting the pre-clean corotron current based on paper thickness and width provides a remedy for the end leakage effect. Sufficient corona treatment can be provided to the residual toner to enable proper cleaning of the photoreceptor when the pre-clean corotron current is adjusted accordingly.

Abstract: A process cartridge for use in a printing machine is provided. The process cartridge includes a first housing portion including a first housing attachment surface and a second housing portion including a second housing attachment surface. At least a portion of the second housing attachment surface is associated with at least a portion of the first housing attachment surface. The process cartridge further includes a plurality of rivets. Each of the plurality of rivets includes a retaining portion thereof. At least one of the first housing portion and the second housing portion define an aperture for passage of the retaining portion of at least one of the rivets therethrough. The other of at least one of the first housing portion and the second housing portion define a cavity for receiving the retaining portion of the at least one rivet. The portion of the housing defining the cavity being interferencely fitted to the retaining portion of the at least one rivet.

Abstract: An apparatus and method of aligning different color print heads of an ink jet printer by printing a sequence of extended-area first alignment elements in a first color, then printing an overlaying sequence of extended-area second alignment elements in a second color. Each of the alignment elements includes an array of spaced apart printed lines. The first alignment elements are printed to nominal reference positions, and the second alignment elements are offset from the reference positions by differing amounts. The degree of overlap of the first and second color lines is readily visible, and the most thoroughly overlapped alignment element may be readily identified. The identity of this element may then be fed back to the printer to respond with electronic alignment measures.

Abstract: A system for producing non-copyable prints. In a xerographic printer, text is printed using clear toner. Thus, the only optical difference between toner and non-toner portions of the page is in the reflectivity. The plastic toner will reflect more light than the paper. A human reader can now read the image by holding the page at such an angle that the eye will intercept the reflected light from the toner, producing a contrast between the lighter appearing toner and the darker appearing paper. However, a copier scanner is always set up to avoid reflected light, by supplying light at an oblique angle and reading at a right angle. In this case the diffused light is approximately equal for both toned and untoned surfaces, the scanner will detect no difference and the copier will not be able to copy the original.

Abstract: When a development unit 30 once taken out from a copying machine 10 is incorporated therein, a developing pressure pin 30a engages with a stop face 106c of a pressure arm 106 to stop the development unit 30. This can prevent the development unit 30 from colliding against a photosensitive drum 56 when the development unit 30 is incorporated into a body of the copying machine 10.

Abstract: A developer contamination measuring apparatus of a printer includes a first pipe portion having a first gap and a second pipe portion having a second gap, a light emitting unit radiating light to the first pipe portion and the second pipe portion, a light detecting unit detecting light reflected or transmitted from the first pipe portion and the second pipe portion to output first and second light receiving signals, respectively, and a developer contamination measuring unit controlling the light emitting unit, and calculating the degree of a contamination due to mixing of other developing materials with the developer from the first and the second light receiving signals. Thus, the degree of contamination of a developer mixed with other developing materials can be precisely calculated, and the developer can be replaced, when the calculated amount of contamination exceeds a predetermined allowable contamination level, to thereby prevent deterioration of print quality.

Abstract: A collector plate 74a, which serves as a contact surface of a rotational electrode member 71, is disposed to intersect an imaginary rotational axis RA of a thermal roller 10. The stationary electrode member 72 can be brought into contact with the collector plate 74a at a position near the rotational center of the collector plate 74a. As a result, friction between the two electrode members can be suppressed so that the electrode members do not wear out as quickly. Defective contact or damage of electrode members can be reduced.

Abstract: An inkjet printing apparatus for printing continuous tone images on a receiver in response to a digital image, including a structure defining a plurality of colorant or colorant precursor receiving chambers, and another structure defining at least one mixing chamber for receiving a plurality of microdrops of colorants or colorant precursors from the colorant or colorant precursor receiving chambers to produce a desired colorant. The apparatus further includes a microdrop nozzle for each receiving chamber and in communication with the mixing chamber and a printing nozzle for each mixing chamber for causing a mixed drop to be delivered to the receiver.

Abstract: The present invention provides an image forming apparatus comprises an image bearing member for bearing a toner image, a rotatable transfer material bearing member for bearing a transfer material, a convey means for conveying the transfer material to the transfer material bearing member, the convey means having a transfer material conveying speed faster than a rotational speed of the transfer material bearing member, and an urging means for urging the transfer material against the transfer material bearing member at an urging position, and wherein the toner image on the image bearing member is transferred onto the transfer material at a transfer position where the transfer material is urged against the transfer material bearing member by the urging means and born on the transfer material bearing member, and, when the transfer material is pulled by a force greater than 10 N along a transfer material conveying direction in a condition that the transfer material is urged against the transfer material bearing mem

Abstract: A supply cartridge contains at least two types of consumable material which are exhausted substantially at the same time over a course of ordinary image reproduction, and the supply cartridge lacks any substantial replacement part so that the supply cartridge replacement wastes no residual life of replacement hardware parts.

Abstract: An electrical connector electrically connectable with a main assembly connector, provided in a main assembly of an electrophotographic image forming apparatus includes storing member for storing information; a plurality of electrical contacts for separably connecting with a contact of the main assembly connector, when they are connected electrically with the main assembly connector; wherein the storing member is electrically connected with each of the electrical contacts with lead lines.

Abstract: There is disclosed a printing system the printing data generation time calculating section of which calculates the time required for generating printing data on the side of the host computer. The printer warm-up time measuring section calculates warming-up time of the printer by referring to database. The warm-up command outputting section sends a warm-up command to the printer controlling section at such a time as the timing for terminating warming-up coincides with the timing for terminating the generation of printing data. Immediately after the completion of warming-up of the printer, since the printing data is transferred, power consumption in the dormant state is reduced.

Abstract: An image forming apparatus includes an endless belt, a pair of belt winding rollers that wind and rotate the endless belt, and a belt shift detecting device that detects a belt shift. The image forming apparatus further includes a roller end moving device that moves one end of one of the belt winding rollers around its other end in response to the detection of a belt shift to suppress the belt shift to a predetermined range, and a belt surface contacting device that pressure contacts the surface of the endless belt. The belt surface contacting device is mounted on a frame that supports a shaft of the belt winding roller to be moved so that its contacting condition does not change during the movement of the belt winding roller moved by the roller end moving device.

Abstract: A check pattern for a registration adjustment under a low resolution condition of 600 dpi.times.600 dpi at a substantially central portion of a printing medium is printed. After performing the registration adjustment based on the printed pattern, the check pattern is printed under a high resolution condition of 1200 dpi.times.600 dpi at a position not causing interference with the former check pattern. On a basis of this, the registration adjustment is again performed. By this, the registration adjustment in high precision printing can be performed easily. Also, two check patterns can be printed on a single printing medium to permit lowering of cost concerning the printing medium to be used in check pattern printing.