Abstract: An apparatus measures the reflectivity of a selected region of a surface. A first light beam is reflected from the selected region and substantially focused on a photodetector. A second light beam is reflected from the selected region and is substantially unfocused on the photodetector. A signal is derived representative of the direct reflectance of light reflected from the surface onto the photodetector as a function of the intensities of the focused light beam and the unfocused light beam detected by the photodetector.

Abstract: A printhead for electrostatic printing comprises a membrane, made of a non-crystalline ceramic material, defining a first surface and a second surface, and defining a plurality of apertures therein. A plurality of addressable segmented electrodes are disposed on the first surface around substantially the periphery of an aperture on the first surface, each segment of the addressable segmented electrodes being isolated from each other segment. A conductive layer is disposed on the second surface around substantially the periphery of at least one aperture on the second surface. The ceramic membrane facilitates the incorporation of active electronic devices on the printhead.

Abstract: An apparatus feeds and separates sheets individually from a stack of sheets. A nudger is disposed adjacent to at least a portion of the stack, and a mechanism, including a rotatable friction feed belt thereon, is disposed adjacent a sheet on the stack to be fed. A variable normal force is provided between the nudger and the friction feed belt of the mechanism. A sensor detects a lead edge of a sheet at a preselected location relative to the mechanism, and the increase in the normal force between the mechanism and the nudger is stopped when the lead edge of a sheet is detected by the sensor.

Abstract: An apparatus for gripping a sheet includes a first gripping member and a second gripping member. The second gripping member includes a base which is movable relative to the first gripping member. The second gripping member further includes a plate which is secured to the base, the plate being adapted to cooperate with the first gripping member to grip the sheet.

Abstract: In an electrophotographic printer having a photoreceptor surface for the creation of electrostatic latent images thereon and a rotating roll for conveying toner particles to a development zone adjacent the photoreceptor surface, an apparatus prevents the migration of toner particles from the roll. A blade, in contact with the roll adjacent one end thereof, causes toner particles adhering to an area of the roll to be moved toward the roll center as the roll rotates.

Abstract: An apparatus feeds and separates sheets individually from a stack of sheets. A nudger is disposed adjacent to at least a portion of the stack, and a mechanism, including a rotatable friction feed belt thereon, is disposed adjacent a sheet on the stack to be fed. A variable normal force is provided between the nudger and the friction feed belt of the mechanism. A sensor detects a lead edge of a sheet at a preselected location relative to the mechanism, and the increase in the normal force between the mechanism and the nudger is stopped when the lead edge of a sheet is detected by the sensor.

Abstract: A stripper finger separates a substrate from a fuser member in an electrophotographic printing apparatus. The stripper finger is a member defining an edge in the form of a symmetrical convex arc across the width of the member. The thickness of the member decreases from a chord through the convex arc perpendicular to the axis of symmetry of the arc, to the edge.

Abstract: A magnetic clutch provides an adjustable slip torque. A housing, having an outer surface of a predetermined frictional coefficient, is disposed around a portion of a shaft, and is rotatable relative to the shaft An outer magnetic member is disposed on the inner surface of the housing, and an inner magnetic member is attached to the shaft and disposed within the housing. The slip torque is adjusted by varying the amount of surface area exposure between the inner magnetic member and the outer magnetic member.

Abstract: In an image scanning device having a scanning array with a plurality of photosites detecting light from an image, the signals from the photosites being output from the scanning array through an amplifier in a sequence having reset pulses between the analog signals for each photosite, an apparatus maintains the reset pulses at a constant offset voltage. A peak follower holds the maximum value of voltage from each cycle of the sequence as the offset voltage, and outputs a constant voltage related to the offset voltage. An amplifier return driver accepts the constant voltage from the peak follower, and maintains the potential between the signal input to the amplifier and the return of the amplifier at a constant value.

Abstract: A skew and bow correction system for a line of beam scanning from a source across a photosensitive surface comprises at least one optical element, having an axis along the line of beam scanning. The principal plane of the optical element at the midpoint of the line of beam scanning is positioned at a first angle relative to the surface, and the principal plane of the optical element at each end of the scan line is oriented relative to the first angle at a twist angle along the axis. The value of the first angle is related to the skew and the bow of the scan line on the surface, and the values of the twist angles are related to the skew of the scan line on the surface.

Abstract: In a xerographic printing apparatus, toner material is thermally fused and fixed onto a surface of a copy sheet by condensing water vapor on the surface of the copy sheet. In the preferred embodiment, the toner material substantially comprises docasanoic acid. The water vapor is condensed on the surface of the copy sheet by means of applying the water vapor onto the surface through a narrow slit moving relative to the surface.

Abstract: A multilayer color photosensitive element made from group III-V alloy semiconductors. Charge is collected from the photosensitive element according to an amount of time it takes for red, green and blue light to travel through the layers. No filters or extra memory or patterning of the layered semiconductor during growth is required to create full color separations on a pixel by pixel basis.

Abstract: An electromagnetically actuated spring clutch permits transference of rotational motion from an input hub to a coaxially-disposed rotatable shaft. A selectively actuable source of magnetic flux, such as an electromagnetic coil, is disposed around at least a portion of the shaft with a space therebetween. A housing, at least a portion of which is conductive of magnetic flux, substantially envelops the outer surface of the source. A shaft flange, also conductive of magnetic flux, is disposed around a portion of the shaft. A helical spring, having a first end attached to the input hub and a free end disposed adjacent the shaft flange, is loosely engageably coiled around the shaft, in the space between the shaft and the source. magnetic flux flowing through the shaft flange attracts the free end of the helical spring and thereby causes the helical spring to contact about and engage the shaft.