Abstract: An electrophotographic device comprises a printhead having at least one laser associated with a corresponding photoconductive surface. Where multiple laser beams are associated with the same photoconductive surface, the laser beams are spaced a predetermined distance from one another in a process direction, which is orthogonal to a scan direction in which the laser beams are swept. The electrophotographic device operates at one of at least two image transfer rates. A controller in the electrophotographic device selectively directs image data to the printhead based, at least in part, upon the selected image transfer rate, the facet resolution, and/or the desired output image resolution. The print speed can thus be adjusted over a relatively wide range.

Abstract: Drive train motor speed is varied in a manner that compensates for characteristic rotational velocity errors of the associated drive train, such as by modulating a drive train motor speed control signal at a modulation phase and amplitude derived from the characterized rotational velocity error. Characterization can be performed on a test system for each drive train of interest, and the compensation values thus obtained can be saved for later use by systems in which the characterized drive trains are used. Thus, a drive train used in a consumables cartridge for an electrophotographic printing (EP) system can be characterized and the corresponding data saved via a label or memory circuit that is affixed to the cartridge. Such data can be used by the EP system in which the cartridge is installed to more accurately control the velocity of the image forming process members driven by the cartridge's characterized drive train.

Abstract: A media sensor for an image forming apparatus is operative to sense and distinguish opaque, transparent or no media in a media path. In one embodiment, an optical source and detector are positioned on opposite sides of the media path, at an acute, non-zero angle with respect to a direction normal to the media path. In other embodiments, an optical source and detector are co-located on the same side of the media path with an optical barrier between them, and one or more reflective surfaces positioned on the opposite side. With no media in the media path, the detector receives a readily detectable amount of optical energy emitted by the source. For opaque media, the detector receives very little, if any, optical energy emitted by the source. For transparent media, the detector receives a level of optical energy between that in the cases of opaque media and no media.

Abstract: An improved data signal electromagnetic emissions system is provided for sending data signals over one or more data pathways. An original data signal is encoded into a set of sideband frequencies that exhibit a lower amplitude than the original data signal; then transmitted over the data pathway and later decoded back into a signal having the original data content. The encoding scheme uses a number of modulation pattern sets that each produce a set of sidebands about the data signal's fundamental and certain harmonic frequencies, in a manner that attempts to make the maximum amplitudes for each set of sidebands substantially equal to one another, although this is also dependent upon the data signal's frequency content.

Abstract: A method of aligning a print image of an electrophotographic machine, the method including the steps of determining a power level of a laser beam, sensing a synch position of the laser beam associated with the scan line and varying a delay time before starting the scan line dependent upon the power level and the synch position.