Abstract: The write lines of a color laser printer are maintained substantially equal throughout the printer's operation by an electronic control arrangement. At the factory, the write lines on all photoconductors of the color laser printer are calibrated to be substantially equal, and the ratio of each write line to a measuring line for each photoconductor is ascertained. During operation of the printer, the length of each of the measuring lines is periodically determined through counting the number of PELslice clock timing pulses produced from a PELslice clock operating at a fixed frequency determined during factory calibration. The length of the write line is determined by the product of the length of the measuring line and the factory calibrated ratio of the length of the write line to the length of the measuring line.

Abstract: An automatic temperature control system which limits the total number of valve cycles for the cold and hot water valves to, for example, a total of ten cycles yet also provides the desired temperature control of water supplied to the wash tub is described. To limit the number of valve cycles, and in one embodiment, the automatic temperature control (ATC) system includes a microprocessor which integrates the temperature of the water provided to the wash tub over time to predict the length of the time period required for the next water valve cycle. The integration balances the energy input on the “OFF” cycle with the energy input during the “ON” cycle. Such balancing limits the number of valve cycles thereby reducing the possibility for premature valve failure and facilitating reduced noise. The ATC control system also provides a pre-treater function. When the pre-treater function is selected, e.g.

Abstract: An electrophotographic image forming apparatus has defined therein a longitudinal or process direction, and includes plural photoconductive drums, each having an image forming surface. Multiple printhead units are provided for generating image information bearing laser beams. Each printhead unit includes optics for scanning the laser beam to form a plurality of scan lines extending across the corresponding photoconductive drum in a transverse scan direction which traverses the process direction. Registration of a scan line from one printhead with a corresponding scan line from another printhead in the process direction is achieved by adjusting the time required to translate one of the scan lines from a location where it is electrostatically formed to a location where it is transferred to an image receiving medium. Adjustment of the translation time may be achieved by modifying the rotational speed of the associated drum.

Abstract: A method of setting a plurality of margins in an electrophotographic machine includes setting a top margin for a reference color black by establishing a first time delay between a vertical synchronization signal and a first line. A right margin or a left margin for the reference color black is set by establishing a second time delay between a horizontal synchronization signal and a start of printing. The other of the right margin and the left margin is set by adjusting a scan speed of a laser beam across a photoconductive element and adjusting a process speed in the cross-scan direction including the speed of the photoconductive element, image accumulation member, and print medium. A bottom margin is set by adjusting the process speed. The other three color planes, cyan, magenta and yellow are then registered or aligned to the reference color plane, black.

Abstract: A method of setting a plurality of margins in an electrophotographic machine includes setting a top margin for a reference color black by establishing a first time delay between a vertical synchronization signal and a first line. A right margin or a left margin for the reference color black is set by establishing a second time delay between a horizontal synchronization signal and a start of printing. The other of the right margin and the left margin is set by adjusting a scan speed of a laser beam across a photoconductive element and adjusting a process speed in the cross-scan direction including the speed of the photoconductive element, image accumulation member, and print medium. A bottom margin is set by adjusting the process speed. The other three color planes, cyan, magenta and yellow are then registered or aligned to the reference color plane, black.

Abstract: A method of aligning a laser printhead in an electrophotographic machine includes providing a fixture with a pair of fixed sensors. The fixed sensors are spaced apart along a length of a first fixture drum axis. Each of the fixed sensors is fixed relative to a second of the fixed drums. The first fixture drum is provided with a pair of floating sensors. The floating sensors are spaced apart along the length of the first fixture drum axis. Each of the floating sensors is fixed relative to the first fixture drum. A laser beam from the laser printhead is scanned across an outside surface of the first fixture drum, the fixed sensors and the floating sensors. An intersection of the scanned laser beam and the outside surface of the first drum defines a scan path. A first skew of the scan path relative to an axis of the first drum is measured using the floating sensors. A second skew of the scan path relative to an axis of the second drum is measured using the fixed sensors.

Abstract: A method of setting a plurality of margins in an electrophotographic machine includes setting a top margin for a reference color black by establishing a first time delay between a vertical synchronization signal and a first line. A right margin or a left margin for the reference color black is set by establishing a second time delay between a horizontal synchronization signal and a start of printing. The other of the right margin and the left margin is set by adjusting a scan speed of a laser beam across a photoconductive element and adjusting a process speed in the cross-scan direction including the speed of the photoconductive element, image accumulation member, and print medium. A bottom margin is set by adjusting the process speed. The other three color planes, cyan, magenta and yellow are then registered or aligned to the reference color plane, black.

Abstract: The write lines of a color laser printer are maintained substantially equal throughout the printer's operation by an electronic control arrangement. At the factory, the write lines on all photoconductors of the color laser printer are calibrated to be substantially equal, and the ratio of each write line to a measuring line for each photoconductor is ascertained. During operation of the printer, the length of each of the measuring lines is periodically determined through counting the number of PELslice clock timing pulses produced from a PELslice clock operating at a fixed frequency determined during factory calibration. The length of the write line is determined by the product of the length of the measuring line and the factory calibrated ratio of the length of the write line to the length of the measuring line.

Abstract: The write lines of a color laser printer are maintained substantially equal throughout the printer's operation by an electronic control arrangement. At the factory, the write lines on all photoconductors of the color laser printer are calibrated to be substantially equal, and the ratio of each write line to a measuring line for each photoconductor is ascertained. During operation of the printer, the length of each of the measuring lines is periodically determined through counting the number of PELslice clock timing pulses produced from a PELslice clock operating at a fixed frequency determined during factory calibration. The length of the write line is determined by the product of the length of the measuring line and the factory calibrated ratio of the length of the write line to the length of the measuring line.