Abstract: A fuser assembly for an electrophotographic imaging device includes a heater including a substrate, a resistive trace disposed and running along a length of the substrate for generating heat for fusing toner to a sheet of media when a current is passed therethrough, and at least three conductors for passing current through the resistive trace. The at least three conductors include a first conductor connected to a first end portion of the resistive trace, a second conductor connected to a second end portion of the resistive trace, and a third conductor connected to the resistive trace at a location between the first end portion and the second end portion thereof. A temperature sensor senses a temperature of an edge segment of the substrate. Based upon the temperature sensed, circuitry selects between the first conductor and the third conductor for passing current through the resistive trace.

Abstract: A method and apparatus to clear the accumulation of toner particles from a doctor element by periodically reversing a bias field between a doctor element and a developer member. The developer member may be biased to a first electrical potential while the doctor element may be biased to a second electrical potential. The second electrical potential may be higher than the first electrical potential. The doctor element and the developer member may be biased from a single voltage supply and a voltage dividing circuit. A bias reversing circuit may cause the second electrical potential to fall, at least temporarily, below that of the first electrical potential when power from the voltage supply is removed. The bias reversing circuit may also cause the first electrical potential to fall with a longer time constant than that of the second electrical potential when power from the voltage supply is removed.

Abstract: An optical scanner is provided having a memory device thereon. The memory device may store operational characteristics of the optical scanner or data that characterizes laser beam scan path and/or laser power requirements by each laser of the optical scanner. The memory device may be used to store historical information such as device temperature, cycles of operation and other historical information of components within a corresponding electrophotographic device. Still further, the electrophotographic device to which the optical scanner is installed may write operational data to the memory device, for example, to store a backup of registration and other operational parameters that are typically stored by the controller of the electrophotographic device.

Abstract: A method of operating an electrophotographic printer includes the steps of: transporting a print medium at a first operating speed using a print medium transport assembly; transporting the print medium from the print medium transport assembly to a fuser assembly, the fuser assembly including a fuser roll; creating a bubble in the print medium between the paper transport assembly and the fuser assembly; determining a temperature associated with the fuser roll; and rotating the fuser roll at a second operating speed which is dependent upon the determined temperature.

Abstract: Heat rolls and fuser belts utilized in the fusing step of the electrophotographic process are disclosed. These belts and rollers eliminate toner offset while still maintaining excellent release characteristics of the printed page from the fuser. The heat rolls comprise a core member having coated thereon a plurality of concentric layers, wherein at least one of said layers (preferably the top layer) does not contain electrically conductive materials and wherein the roll exhibits electrical breakdown at about 250 volts or less. The fuser belts comprise a heat resistant resin substrate (such as a polyimide belt) carrying thereon a plurality of layers coating the outer surface of said belt, wherein at least one of said layers (preferably the top layer) does not contain electrically conductive materials and wherein the belt exhibits electrical breakdown at about 250 volts or less.

Abstract: Transfer belt subassembly for a color printer includes a transfer belt, home position indicator, temperature sensor, and memory. The transfer belt subassembly is measured and characterized after fabrication, before being installed in a printer. Measurement and calibration data for the transfer belt is stored in memory as part of the subassembly, including data representing velocity characteristics of the transfer belt and temperature compensation factors used by an engine-controller in a method to govern the speed of the drive motor. When the transfer belt subassembly is inserted into a printer, the engine-controller is operative in response to data stored in the memory and sensed belt velocity and temperature data, providing adjustment of belt velocity and compensation for variations in the transfer belt speed. Using the predetermined characterizing data, precise alignment of the color planes with respect to one another is achieved for accurate color printing.

Abstract: A method of printing with an electrophotographic machine includes providing a first optical sensor for sensing a start-of-scan position of a laser beam produced by a scanning laser printhead and transmitting a first position signal indicative thereof A second optical sensor senses an end-of-scan position of the laser beam produced by the scanning laser printhead and transmits a second position signal indicative thereof A temperature of the scanning laser printhead is measured with a temperature sensing device. A plurality of positions of each of the first optical sensor and the second optical sensor are empirically determined at each of a plurality of values of the temperature of the scanning laser beam printhead.

Abstract: Heat rolls and fuser belts utilized in the fusing step of the electrophotographic process are disclosed. These belts and rollers eliminate toner offset while still maintaining excellent release characteristics of the printed page from the fuser. The heat rolls comprise a core member having coated thereon a plurality of concentric layers, wherein at least one of said layers (preferably the top layer) does not contain electrically conductive materials and wherein the roll exhibits electrical breakdown at about 250 volts or less. The fuser belts comprise a heat resistant resin substrate (such as a polyimide belt) carrying thereon a plurality of layers coating the outer surface of said belt, wherein at least one of said layers (preferably the top layer) does not contain electrically conductive materials and wherein the belt exhibits electrical breakdown at about 250 volts or less.

Abstract: A transfer belt subassembly for a color printer includes a transfer belt, a home position indicator, a temperature sensor and a memory. The transfer belt subassembly is measured and characterized after it fabrication and before being installed in a printer. The measurement and calibration data for the transfer belt is stored in the memory that is part of the subassembly. The memory stores data representing the velocity characteristics of the transfer belt and temperature compensation factors for use by a engine-controller of the printer to govern the speed of the drive motor. When the transfer belt subassembly is inserted into a printer, the engine-controller is operative in response to data stored in the memory and sensed belt velocity and temperature data to provide adjustment of belt velocity and compensation for variations in the transfer belt speed. By use of the predetermined characterizing data, precise alignment of the color planes with respect to one another is achieved for accurate color printing.

Abstract: Heat rolls and fuser belts utilized in the fusing step of the electrophotographic process are disclosed. These belts and rollers eliminate toner offset while still maintaining excellent release characteristics of the printed page from the fuser. The heat rolls comprise a core member having coated thereon a plurality of concentric layers, wherein at least one of said layers (preferably the top layer) does not contain electrically conductive materials and wherein the roll exhibits electrical breakdown at about 250 volts or less. The fuser belts comprise a heat resistant resin substrate (such as a polyimide belt) carrying thereon a plurality of layers coating the outer surface of said belt, wherein at least one of said layers (preferably the top layer) does not contain electrically conductive materials and wherein the belt exhibits electrical breakdown at about 250 volts or less.

Abstract: Heat rolls and fuser belts utilized in the fusing step of the electrophotographic process are disclosed. These belts and rollers eliminate toner offset while still maintaining excellent release characteristics of the printed page from the fuser. The heat rolls comprise a core member having coated thereon a plurality of concentric layers, wherein at least one of said layers (preferably the top layer) does not contain electrically conductive materials and wherein the roll exhibits electrical breakdown at about 250 volts or less. The fuser belts comprise a heat resistant resin substrate (such as a polyimide belt) carrying thereon a plurality of layers coating the outer surface of said belt, wherein at least one of said layers (preferably the top layer) does not contain electrically conductive materials and wherein the belt exhibits electrical breakdown at about 250 volts or less.

Abstract: An image-fixing device for use in an electrophotographic process which includes an electrode (discharge member) on the exit side of a fuser mechanism is disclosed. This mechanism eliminates toner offset without requiring reformulation of the fuser or pressure rollers or restructuring of the fuser, and without compromising the release properties of those rollers. The preferred electrode has a saw-tooth configuration and is placed close to, but not contacting, the pressure roller and the back side of the printed page. A voltage, typically from about 200 to about 1,000 volts is applied to that electrode; the voltage has a polarity which is opposite the charge of the toner on the printed page.

Abstract: Disclosed is a cartridge having an encoder wheel thereon for encoding EP supply cartridge characteristic information for an electrophotographic machine, the cartridge comprising, a sump for carrying an initial amount of toner. A shaft is mounted for rotation in said sump, and an agitator or paddle is mounted thereon in such a manner that when the shaft rotates, the paddle rotates into, through and out of engagement with toner carried by the sump. A single encoder wheel is mounted on the shaft, external of the sump, the encoder wheel positioned for proximate mating coaction with a coded wheel reader when the cartridge is mounted in position in the electrophotographic machine. A drive means, and a variable torque flexible coupling connects the drive means to the shaft to effect rotation thereof.

Abstract: Cartridge (1) contains a brush charger (32) and printer (40) contains a charge roller (30). Upon installation of the cartridge a top shutter (7) is moved downward and the charge roller is moved by a pivoted arm (44) through the opening left by the shutter to contact a photoconductor drum (24) in the cartridge. In operation the roller functions after charging by the brush at a potential to control the final charge on a photoconductor prior to xerographic imaging. The precharging by the brush greatly reduces deterioration of the charge roller, permitting long machine life with the accurate and uniform operation of a charge roller.

Abstract: In an electrophotographic reproduction device, such as a copier or a printer, having a transfer station (17) whereat toner images are sequentially transferred from the surface of a moving photoconductor (10) to the adjacent surface of sheets of moving and spaced transfer material, such as paper, the transfer station is controlled in a manner to produce a substantially similar electrical effect on the photoconductor both when a sheet of transfer material resides in the transfer station intermediate the photoconductor and the transfer station, and when no sheet of transfer material is intermediate the photoconductor and the transfer station.

Abstract: In a multinozzle ink jet printing system, a closed loop servo system drives the drop generator so that the distance between the streams at which ink droplets are detached is maintained at an optimum range. One or more sensors are positioned downstream from the multinozzle plate of the ink jet printing system. The sensors sense the flight time of ink droplets and output signals which are developed into a variable voltage for controlling the drop generator.

Abstract: A uniform velocity and/or time of flight profile across the jet streams of a multinozzle aspirated ink jet printer is maintained by a closed loop servo system. The servo system includes a drop charge sensor which senses the time of flight of charge droplets in the streams and generates a controlled signal. The signal is utilized by a controller means to generate controlled voltages. The voltages are used to adjust the velocity of a motor/blower apparatus which supplies air to the aspirated ink jet printer.

Abstract: An ultrasonic transducer system comprising a transducer array, control circuit and display system wherein the control system is able to actuate the transducer elements in groups of N and N+1 elements, actuate the groups in non-sequential order, actuate groups of selectively different sizes, subject the actuation signals to and the echo signals from the transducers to pre-programmable delay periods, compress the echo signals into a logarithmic representation, transform the echo signals into plural simultaneous visual displays on a standard TV monitor in split screen format, and transform the display of discrete points in the visual display into continuous lines. Further, each transducer element in the array may consist of a split or paired set of transducers.