Abstract: A method and apparatus for automating the design of morphological or template-based filters for print quality enhancement. A plurality of different phase, but same resolution, subsampled images are generated from training documents. Statistical data derived therefrom is then employed in an automated process to generate filters. The filters may be used for resolution enhancement and/or conversion of bitmap images. Furthermore, the statistical data is used to produce filters that are intended to not only optimize image structure, but image density as well.

Abstract: The present invention is a method and apparatus for improving the depth of focus in a raster output scanner (ROS), and more particularly to a system for maximizing the line separation depth of focus of a multispot ROS while maintaining the system common depth of focus. In a preferred design for a ROS-based system, the system common depth of focus (system common DOF) is maximized, where the system common DOF is characterized as the depth-of-focus over which all performance parameters are met. More specifically, the performance parameters are intended to include the following five factors: (1) scan and cross-scan spot size; (2) wobble; (3) differential bow; (4) line separation; and (5) scan linearity. Maximizing the system common DOF means to maximize the depth-of-focus while at all times meeting or exceeding the performance requirements for the five listed parameters. The optical system design achieves a desirable system common DOF while maintaining a line separation of 127 .mu.m (1/200 inch).

Abstract: A method and apparatus for identifying regions within a first binary image where half-bitting may be present, converting those regions to a multiple-bit/pixel representation so as to accurately represent the image density and the intended edge structure for the region, and further generating an enhanced resolution representation of the region in either a second binary image, wherein the second binary image has a spatial resolution greater than the first image, or a multiple-bit per pixel (gray) image at the same resolution as the input image so as to enable an improved rendering of the first binary image.

Abstract: A method for comparing two image sections consisting of a plurality of image signals, or pixels, where each image section represents a token (e.g., character, symbol, glyph, string of components, or similar units of semantic understanding), in order to identify when similar tokens are present within the image sections. The invention further operates without the need for individually detecting and/or identifying the components making up the tokens. In one embodiment, the method relies upon the detection of connected components within words to first isolate individual word tokens and then applies a two stage process where dilated images of the tokens are compared with model representations of the tokens to determine the relative similarity therebetween.

Abstract: The present invention is a method and apparatus for restoring or correcting digital images scanned in the presence of mechanical vibration, thereby improving the quality of the output image. In a document scanner, a linear sensor moving relative to a document placed upon a platen is scanned in a manner wherein fluctuations in the nominal scanning velocity are observed. Recognizing that the output of a single photosensor in the linear sensor array is proportional to the integrated irradiance received by the sensor as it scans through an exposure region, when vibratory motion of the sensor array is considered, the actual size of the exposure region is time-varying. The fluctuations or vibrations introduce artifacts such as brightness fluctuation and geometric warping which are eliminated or significantly reduced in accordance with the method of the present invention.

Abstract: The present invention is an apparatus for controlling the ignition of an internal combustion engine. The present invention employs a high voltage transistor, preferably a high voltage MOSFET, to switch DC voltages on the order of 1 kV to regulate the flow of current to an input tap of a primary ignition transformer or coil. The high voltage transistor is controllable by conventional logic-level voltages produced by an ignition control module.

Abstract: The present invention is an apparatus for eliminating differential scanline bow in a raster output scanner (ROS) printing system. The apparatus employs a field lens device at the output of a pre-scanning optical assembly in order to direct the laser beams toward the scanning surface, or facet, at a right angle to the scanning surface, thereby eliminating a source of scanline bow.

Abstract: The present invention is a method and apparatus for producing an image on the image receiving member. The method and apparatus employ a photoconductive member that is charged by the deposition of charged marking particles on an outer surface thereof. Subsequently, selective regions of the photoconductor are selectively exposed to light patterns to cause the photoconductor to exhibit a photoresponse, thereby collapsing the internal electric field in the exposed regions but not in the unexposed regions. When a field neutralizing bias and acoustic energy are applied in a transfer region, toner in the unexposed regions is transferred to an intermediate member or any substrate interposed between the photoconductive surface and the biasing electrode.

Abstract: The present invention is a digital electronics system for generating multiple pulses within a predefined pixel clock period in a digital output device, where both a leading edge delay and a trailing edge delay are specified for a first pulse to be generated during the predetermined clock period. Pulse forming circuitry generates the first pulse during the portion of the clock period between the leading edge delay and the trailing edge delay, and an inverting circuit, selectable on a clock period basis, is activated to produce complimentary pulses within the selected clock period. The system is depicted as a two phase embodiment which enables high-speed operation.

Abstract: The present invention is a method and apparatus for the enhancement of 1 bit per pixel image signals to produce a multiple-bit per pixel form. A binary input image is passed through a plurality of filters to generate level slices. The filters are stack filters implemented as look-up table or template-based filters, morphological filters, or any similar binary-to-binary filters that could be used to generate level slices. Each of the N-1 filters is used to produce the slices, where N is the number of possible gray-scale levels desired in the output image. Once the slices are generated, the resulting binary image data therein is recombined, by adding or stacking, to produce the desired multiple-bit per pixel output.

Abstract: A non-contacting electrostatic measurement apparatus including a vibratory element and an electrode, affixed to the vibratory element, suitable for sensing a capacitive coupling relationship with an electrostatic field to produce a signal indicative of the magnitude of the electrostatic field. The signal is transmitted to signal processing circuitry via conductive fibers so as to impose little mechanical loading on the vibrating electrode. The electrode may be either unshielded, for an electrically floating electrostatic voltmeter, or shielded, for an electrostatic voltmeter employing electrically grounded components.

Abstract: An electrostatic voltmeter suitable for use in a non-contacting, positive or negative potential sensing, type electrostatic voltmeter. The invention enables a flexible, low cost electrostatic voltmeter to be produced using high-voltage field-effect transistors in the circuit design. The invention further includes input conditioning components that enable high-voltage sensing and high-voltage feedback in such a manner that processing of the input signal from the sensor is accomplished without producing a variation in the current passing through the field-effect transistor in response to voltage variations. Elimination of this variation further reduces the susceptibility of the remaining signal processing circuitry to transient direct current signals. A differential cascode as the input stage is the preferred configuration for the input conditioning components.

Abstract: The present invention is a an apparatus for enhancing the output along edges of discharged area developed regions in a tri-level imaging system employing a pulse width and position modulated signal ROS for exposure. The invention enables the identification and selective alteration of video data used to drive the ROS so as to extend the developed regions by a selected amount and eliminate digitization artifacts present in the image to be printed. The extension of the discharged area developed regions is accomplished by extending the width of, or adding separate, exposure pulses in adjacent areas to enable development within a portion of those regions.

Abstract: The present invention is a method and apparatus for defining the critical characteristics of a pallet, or tray, used to supply workpieces to an automated, flexible assembly station or workcell. Once the characteristics are described and stored in memory, they may be used to uniquely identify workpieces which are determined to be defective during the automatic assembly operations.

Abstract: An apparatus and method for reliably monitoring the position of a radiant energy beam, for example, a scanning laser beam such as that produced by a raster output scanning system to expose a photoresponsive member, where the beam traverses the surface of a photoreceptive member at a high rate of speed. The apparatus, which includes a lateral-effect photodiode, is also capable of signaling when the radiant energy beam traverses a specific location. The apparatus may also be used to determine the relative intensity of the radiant energy beam, thereby significantly reducing the space and expense necessary to monitor the radiant energy beam by combining multiple sensing operation in a single apparatus.

Abstract: The present invention is a system for utilizing a printable, yet unobtrusive glyph or similar two-dimensionally encoded mark to identify copyrighted documents. Upon attempting to reproduce such a document, the glyph is detected, decoded and used to accurately collect and/or record a copyright royalty for the reproduction of the document, or to prevent such reproduction. Furthermore, the glyph may also include additional information so as to enable an electronic copyright royalty accounting system, capable of interpreting the encoded information, to track and/or account for copyright royalties which accrue during reproduction of all or portions of the original document.

Abstract: The present invention is a multispot laser light source assembled from at least two individual laser diodes in accordance with a design model. The multispot laser includes at least two semiconductor laser diodes, both of which are permanently affixed to a chip carrier. The chip carrier rigidly supports the diodes and conducts heat away from the the diodes to be dissipated by a heat sink. The present invention is further characterized by a predefined relationship between the chip carrier material, the relative dimensions of the chip carrier, and the separation distance of the diodes from the heatsink, which results in significant reduction in the thermal droop and crosstalk between the diodes.

Abstract: The present invention is a method and apparatus for processing a color document for moire-free printing, the color document including a plurality of color separations each defined with a set of image signals representing optical density with m possible density levels, while a printer is capable of rendering density with n density levels. The invention employs a spatial resolution scaler to produce m-bit signals at a spatial resolution that is a function of the halftone screen angle, base dot pitch, and desired halftone cell size. Subsequently, the m-bit signals at the desired spatial resolution (frequency and angle) are halftoned to produce n-bit signals that are printed with a raster output scanning-type printer suitable for printing at selectively variable spots per inch in both the fast and slow scan directions.

Abstract: The present invention is directed to a method and apparatus for fabricating a dual beam semiconductor laser, wherein the laser includes first and second semiconductor laser dies respectively affixed to one another while separated by intervening alignment structures. The alignment structures provide accurate placement of the dual laser beams with respect to one another while also assuring thermal isolation of the laser diodes. The fabrication method employs photolithographic techniques to accurately position the alignment structures across an entire semiconductor wafer, thereby assuring accuracy in alignment of the assembled dual beam lasers. As a result, the need for multiple-step alignment operations commonly employed in the production of multiple diode laser devices is eliminated.

Abstract: A method for determining the boundaries of text or character strings represented in an array of image data by shape, without a requirement for individually detecting and/or identifying the character or characters making up the strings. The method relies upon the detection of connected components within words to first determine text line boundaries and to isolate the connected components into text rows. Subsequently, the structural relationships between the components within and defining rows (i.e. overlap, inter-character spacing, and inter-word spacing), are used to further combine adjacent sets of connected components into words or similar units of semantic understanding within text rows.