Abstract: A method and apparatus for controlling the execution of image processing operations carried out on an array of image signals, the specific operations having been identified by a plurality of predefined windows. The windows are divided into a plurality of non-overlapping tiles, the boundaries of which correspond to transitions from one window region to another. Each tile therefore defines an exclusive region within the array of image signals, and the image processing operations to be applied to the signals within the boundaries of that region. Tile data is stored in one of two memory banks, thereby enabling bank switching and reprogramming of the device in real-time to permit management of complex window shapes. The apparatus is designed to efficiently manage the identification of tile regions while minimizing the required decoding hardware. The apparatus also provides flexibility of programming resulting in greater efficiency of memory usage.

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 power supply apparatus capable of providing one or more individually controllable high voltage outputs for various components within an electrophotographic printing machine. Receiving power from an input power source, the power supply apparatus produces various high voltage outputs, wherein each output is capable of providing a range of high voltage potentials. The individual high voltage outputs are regulated by a microcontroller which receives an analog voltage signal from a voltage sensor and produces a voltage control signal which is then used to regulate the outputs in a conventional manner for resonant- or switching-type power supplies. The microcontroller regulates the output potentials by varying the voltage control signals for each of the outputs as a function of the difference in magnitude between the analog voltage signal and a voltage set-point value associated with the output.

Abstract: The present invention is a method and apparatus for automatically monitoring the output intensity of an analog raster output scanning (ROS) system. The invention further includes the ability to recognize when the output intensity is not within a predetermined tolerance range, where the system will automatically recalibrate to achieve a desired linear transformation from the input image greyscale intensity to the ROS exposure intensity.

Abstract: A method and apparatus for reducing the distortion of image signals captured by an asynchronous scanning system during a transient period caused by temporarily disabling the scanning operation. Where in during normal operation, the asynchronous scanning system drives a document to be scanned relative to a scanning array which produces image signals representative of the document. Subsequently, the signals are transmitted to a host through an interface at a rate which may exceed the reception rate of the host, the asynchronous operation of the scanning system being regulated by start and stop signals which, respectively, enable and disable the scanning operation.

Abstract: The present invention is directed to a method 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: The present invention is a method for automating the design of pattern matching templates used to implement a print quality enhancement filter that preserves image density More particularly, the method is directed to the use of a representative set of page description language decomposed or scanned training documents, and statistical data derived therefrom, in an automated process that generates one or more sets of template-pattern pairs that are used as filters for resolution enhancement and/or conversion of bitmap images.

Abstract: The present invention encompasses both a method and an apparatus for fabricating a multiple beam semiconductor laser array, wherein the laser includes a plurality of semiconductor laser dies affixed in a linear fashion to a supporting heatsink. Accurate alignment of the lasers and control of interlaser spacing is achieved through the use of alignment structures formed on the mounting surface of the heatsink. Once assembled, the alignment structures remain in an abutting relationship with the ridge waveguides present on each of the semiconductor lasers. The method not only enables the accurate placement of the laser diodes relative to one another so as to reduce interlaser spacing error, but also eliminates the need for multiple-step alignment operations to produce the multiple diode laser array.

Abstract: The present invention is a method and apparatus for printing using an intermediate member acting as a receptor for marking particles representing an image. The marking particles may be deposited directly or indirectly on the member, after which time the member is exposed, via an internal heat source, to an elevated temperature sufficient to cause the melting and coalescing of the marking particles. Subsequently, the intermediate member is advanced so as to place the tackified marking particles present on the outer surface thereof into intimate contact with the surface of a recording sheet.

Abstract: The present invention is an apparatus for tuning or altering the charge potential limiting effect that a scorotron grid has upon an adjacent charge receiving surface. The scorotron charging apparatus utilizes corona producing means, spaced above the charge retentive surface, for emitting corona ions in response to a high voltage potential applied thereto, and a flexible grid, suspended between said corona producing means and the charge retentive surface in a nonplanar fashion, such that the spacing between said grid and the charge retentive surface is variable along at least one region of said grid.

Abstract: The present invention is a method for fabricating a multiple beam semiconductor laser, wherein the laser includes first and second semiconductor laser dies respectively affixed to a pair of supporting heatsinks. The method utilizes a laminating process to accurately position the supporting heatsinks relative to one another yet on opposite sides of an intermediate spacer to form a sandwich-like element. After permanently affixing the sandwich-like element to a base plate, the intermediate spacer is dissolved or otherwise removed to expose the mounting surfaces for the laser dies. The method not only enables the accurate placement of the heatsinks relative to one another so as to reduce the positional error, but also eliminates the need for subsequent multiple-step laser beam alignment operations.

Abstract: An electrostatic measurement apparatus for generating a modified electrical signal in proportion to an electrostatic potential present on a surface. The apparatus includes a sensor for producing a signal representative of the electrostatic potential on the surface. The apparatus also includes a high-voltage level shifter and a converter to transform the sensor signal into a low-voltage signal indicative of the surface potential. The electrostatic measurement apparatus is implemented using high-voltage and low-voltage integrated circuit technology.

Abstract: A method for determining the boundaries of a symbol or word string within an image, including the steps of determining page orientation, isolating symbol strings from adjacent symbol strings, establishing a set of boundaries or references with respect to which measurements about, or further processing of, the symbol string may be made.

Abstract: The present invention is a method and apparatus for regulating the velocity of a member constrained to move about a predefined path. The invention comprises a magnetic patch or strip, located on a surface of the member, and having a plurality of magnetic signals recorded thereon, along with a magnetic detector, positioned in proximity to said magnetic strip, for sensing the magnetic signals recorded thereon, during movement of the member, and producing an output signal in response to the magnetic signals. The invention further comprises means, operatively connected to impart a driving force to the member, and control means for regulating said driving means so that the member is driven at a velocity which is a function of the output signal.

Abstract: A method and apparatus for controlling the execution of image processing operations carried out on an array of image signals, the specific operations having been identified by a plurality of predefined windows. The windows are divided into a plurality of non-overlapping tiles, the boundaries of which correspond to transitions from one window region to another. Each tile therefore defines an exclusive region within the array of image signals, and the image processing operations to be applied to the signals within the boundaries of that region. Tile data is stored in one of two memory banks, thereby enabling bank switching and reprogramming of the device in real-time to permit management of complex window shapes. The apparatus is designed to efficiently manage the identification of tile regions while minimizing the required decoding hardware. The apparatus also provides flexibility of programming resulting in greater efficiency of memory usage.

Abstract: The present invention is a charging apparatus capable of electrically tuning or altering, on a relatively local scale, the corona ion current passing between a corona producing device and a charge retentive surface. The charging apparatus, which may be either a corotron or a scorotron, is specifically adapted to apply a uniform charge to a charge retentive surface which characteristically exhibits non-uniform charging behavior. More specifically, the charging apparatus comprises corona producing devices, spaced apart from the charge retentive surface, for emitting a corona ion current, and device, responsive to a bias voltage, for locally altering the corona ion current passing between said corona producing device and the charge retentive surface.

Abstract: The present invention is a method and apparatus for selectively altering the sensitivity of an optical sensor. The sensor has both a light source and a detector which are optically aligned with one another. The detector produces a first output signal level in response to light having an illumination intensity greater than or equal to a threshold intensity, and a second output signal level in response to light having an illumination intensity less than a threshold intensity. The sensor further includes the ability to selectively alter the illumination intensity of the light emitted by the light source to a lower level between the threshold intensity and the normal operating intensity. Hence, operating at the lower intensity enables the sensor to detect translucent sheets or facilitates identification of marginally operable sensors.

Abstract: A method for converting binary image data originally generated at a lower resolution into representative binary image data of a higher resolution, wherein the conversion ratio, or magnification factor, is an integer value. Also included are methods for smoothing the interpolated output image and thereby reducing objectionable visual characteristics observable in digitally encoded data using conventional magnification techniques.

Abstract: An apparatus for efficiently determining the background level of an image, based upon a sampling of the image, during processing of the image signals and without the need for a prior scan operation. The apparatus includes programmable sampling counters, to indicate when image signals for background determination are present on the video path, and an image signal verification device for excluding signals which are not representative of background regions of the image. The background determination apparatus also includes arithmetic circuitry for calculating a background level based upon the sampled image signals and for determining additional threshold levels based upon the background level.

Abstract: An electrostatic measurement apparatus for generating a modified electrical signal in proportion to an electrostatic potential present on a surface. The apparatus includes a sensor for producing a signal representative of the electrostatic potential on the surface. The apparatus also includes high-voltage and low-voltage devices combined to produce an amplifier which transforms the sensor signal into a low-voltage signal indicative the surface potential. The electrostatic measurement apparatus is implemented using high-voltage and low-voltage integrated circuit technology.