Abstract: A method and apparatus for performing pipelined computations that include cross-iteration computations. The apparatus includes a functional unit having at least one input and an output, each input being operable to receive an input data value and an associated input data validity tag indicative of the validity of the input data value and the output being operable to provide an output data value and an associated output data validity tag indicative of the validity of the output data value. The first functional unit is operable in a first mode in which an output data value from the first functional unit is valid if all of the input data values are valid, and in a second mode in which the output data value from the first functional unit is valid if any of the input data values is valid.

Abstract: A capacitive position encoder which provides a digital output indication of the relative position between two plates. One of the plates includes first and second conductive input areas which are separated by a gap having the shape corresponding to a square wave. The second plate includes a number of rectangular output pads whose length is equal to one-half of the wavelength of the square wave. The pads are separated from one another by an integral fraction of the wavelength. Periodic input signals which are the inverse of one another are applied to the input areas and are capacitively coupled to the output pads. When the degree of overlap between an output pad and the input areas is equal, a null signal will be generated. Each pad will provide a null signal corresponding to a different position of the plates.

Abstract: A capacitive position encoder which provides a digital output indication of the relative position between two plates. One of the plates includes first and second conductive input areas which are separated by a gap having the shape corresponding to a square wave. The second plate includes a number of rectangular output pads whose length is equal to one-half of the wavelength of the square wave. The pads are separated from one another by an integral fraction of the wavelength. Periodic input signals which are the inverse of one another are applied to the input areas and are capacitively coupled to the output pads. When the degree of overlap between an output pad and the input areas is equal, a null signal will be generated. Each pad will provide a null signal corresponding to a different position of the plates.

Abstract: A simple flexible magnetic disk memory system is provided which enables precise positioning of a read/write head to follow a data track, despite non-uniform expansion or contraction of the disk. Several positioning sectors of the disk are formed which have positioning tracks recorded thereon, and several corresponding holes are punched in the disk to enable an optical sensor to determine the sector locations. Although a step motor positions a head at the approximate middle of a selected data track, an analog circuit repeatedly adjusts the head location as each positioning sector passes the head. Four positioning sectors can be used which are each aligned with or angled by 90.degree. from the direction of machining of the sheet material of which the disk was made, to minimize track run-out in each data region that lies between positioning sectors.

Abstract: A process for producing an electrostatographic image wherein a uniformly charged photoconductive plate is exposed to a pattern of light and shadow to produce an electrostatic latent image, the continuous zones of the photoconductive plate which do not receive sufficient light during the exposure to discharge the plate are subsequently discharged and thereafter the charged areas of the plate are developed to provide a developed electrostatograpic image.

Abstract: A sheet stripping apparatus for an electrostatographic copying machine for separating copy sheets from the copying machine photoreceptor following image transfer. The stripping apparatus as aforesaid consists of one or more disc like elements, supported for rotation upon an arm such that the arcuate edge of the disc is in stripping contact with the photoreceptor surface downstream of the transfer station. In one embodiment, control means are provided to bring the stripping disc or discs into and out of contact with the photoreceptor in timed relationship to movement of the copy sheet. In another embodiment, means are provided to turn the disc, either continuously or by increments, so as to present fresh disc surface and avoid flats.

Abstract: A carriage drive apparatus comprising a carriage, a drive mechanism to drive the carriage in one direction, a shaft rotatable at a constant speed, an overrunning clutch mounted on the shaft, and at least one lever connecting the clutch and the carriage, the lever pivoting about the shaft. The arrangement is such that on movement of the carriage in the one direction, the lever is moved, but is prevented from rotating about the shaft at greater than the given speed by the overrunning clutch. A plurality of levers may be employed. The apparatus is particularly useful for providing controlled deceleration during the return scan of a scanning lamp carriage of a reproducing machine.

Abstract: Apparatus for forming electrostatographic reproductions back-to-back on suitable support surfaces including first and second photoconductive imaging surfaces and means to provide a developed image on each photoconductive surface and provide simultaneous transfer of the developed images from the photoconductive surfaces onto both of the support surfaces.