Abstract: A method and apparatus for processing messages. In one illustrative embodiment, a processor unit determines whether a predetermined number of keywords or a predetermined number of combinations of keywords associated with a recipient of a message is present in the message in response to receiving the message. In response to a determination that the number of keywords is present in the message, the processor unit generates an alert for the recipient.

Abstract: An exposure system for electrophotographic apparatus having an aperture plate for masking one or more laser beams. The plate contains one or more apertures which have irregular edges to form a gaussian light distribution for the light beams passing through the apertures. A saw-toothed edge is used with a predetermined amplitude ratio to predictably attenuate the light at the edges which correspond to the process or in-track direction in the exposed image. The gaussian distribution is more tolerable of spacing changes in scan lines and improves the continuity of process direction lines in the finished image.

Abstract: In a laser printer, light beams need to be focused onto a printing surface to form points where print indicia are to effect a print image. In a printer where it is desirable to have variable pitch print characters, a new method has been employed to create variable print character pitches. Multiple non-parallel points of light are emitted through a collimating lens onto a wedge shaped optical component which directs the multiple beams of light into parallel alignment. The optical wedge has one planar surface perpendicular to at least one light beam emitted through the collimating lens. This light beam is normal to the perpendicular planar surface and passes through the wedge without being deflected. The optical wedge also has one or more planar surfaces that direct the other light beams into parallel alignment with the undeflected light beam.

Abstract: An image scanning apparatus for use on a laser electrophotographic printer provides improved imaging in both the scan and process direction in a printer using a multiple spot printhead.

Abstract: An aspheric lens exhibiting varying optical power as a function of locating along the longitudinal axis of the lens is intended for use in an electrophotographic printer of the type having a mirror for providing tilt error and scan bow error correction of a laser beam to be imaged at a photoconductor surface.

Abstract: In an electrophotographic printer or the like, compensation is provided for environmental effects (temperature, humidity, photoconductor aging, etc.) which would otherwise affect print quality. Analyzing print data allows identification of compensation locations; those are locations at which compensation is most critical, such as single pel lines. A series of clock pulses of varying phase displacement are employed, and selected based on environmental variations, so as to modify the print data at the identified compensation locations. The print data comprises a series of pulses. Compensation to control the width of lines perpendicular to the scan direction is effected by selectively advancing the leading edge of pulses defining a white/black transition and delaying the trailing edge of pulses defining the black/white transition. This control then affects the duration of the print pulses.

Abstract: An optical system for use with laser chips to counteract variations in wavelength produced by semiconductor chips, to counteract astigmatism effects common to laser chips, to counteract variations in the distance between the plane of emission of the beam and the plane of a collimating lens, to counteract variations in beam size in perpendicular planes, to counteract variations in the divergence angle of emission common to laser chips, and to counteract tilt variations caused by imperfect reflecting surfaces. The system includes an apertured achromatic doublet lens for collimating the beam, a cylindrical lens, a rotating mirror, and a combination of toroidal and spherical lens.

Abstract: An acousto-optic deflector may selectively deflect an applied light beam. The remaining undeflected zero-order beam varies considerably in power depending upon whether the beam is deflected. The zero-order beam is modulated and directed at a detection arrangement to detect a characteristic of the beam other than the selective deflection power variation. The modulation and detection is best employed to detect position feedback for an informational writing beam. An exemplary detection arrangement having a defined ringing frequency with a long shift time constant detects an amplitude modulation of the beam having a significantly higher frequency than that of the selective deflection power variation. The feedback may be in the form of an oscillation representing the position of the deflected beam as it is swept in a raster format and the detection arrangement detects the amplitude oscillations as indicative of the feedback.