Self calibrating pulse width modulator for use in electrostatic printing applications
Granted: December 26, 2000
Patent Number:
6166821
An arrangement for producing a variable width pulse is disclosed for use in an electrostatic printing mechanism which is adapted to produce grayscale intensity of a pixel to be printed based on predetermined digital data. The variable width pulse is formed during a clock interval which is established by a clock signal such that the width of the pulse during the clock interval is based on the digital data and corresponds to a grayscale intensity of the pixel to be printed. The arrangement…
Printing system and method
Granted: November 7, 2000
Patent Number:
RE36947
A image is printed from a source of drawing instructions. The image is reducible to pixels arranged in a plurality of ranked image lines. The system employs a storage device having compressed and uncompressed regions. Each region has a designated capacity and each is arranged to store pixels of one more of the plurality of image lines. A drawing processor is coupled to the storage device and can be coupled to the source of drawing instructions for responding thereto. This drawing…
Method and apparatus for creating personalized documents that include variable data
Granted: October 17, 2000
Patent Number:
6134018
A technique is described for adding variable data to a print job, while requiring a minimum amount of storage. Key to the invention is the use of a data compression algorithm during RIPing. During a first stage of operation, a master document is RIPed into a compressed format and saved in a cache, such as RAM or disk storage. It is important to note that RIPing and data compression are performed simultaneously. This minimizes the amount of processing power necessary to RIP and compress a…
Method and apparatus for producing threshold arrays using variance minimization and sparse image calculations
Granted: September 19, 2000
Patent Number:
6122407
A method and apparatus for creating threshold arrays having a minimized gray scale variance without geometric artifacts. The invention comprises the steps of processing each candidate pixel in the threshold array using a variance minimization technique and applying a sparse image calculation on the same pixel. The preferred embodiment of the invention comprises the application of a variance minimization technique on a threshold array. The threshold array is analyzed on a pixel-by-pixel…
Robotic plotter system
Granted: September 12, 2000
Patent Number:
6116707
A robotic plotting system 10 is provided, in which a robotic plotter 18 having a printhead 18 is placed on a substantially flat horizontal surface 23, upon a recording medium 22, and is directed across the medium 22 by ranging signals 16 transmitted to the printhead 18 from the periphery of the recording medium 22. In one embodiment, the robotic printhead 18 includes a motorized drive mechanism 26, 28 that propels it across the surface of the recording medium 22 in a controlled manner,…
Transducer signal waveshaping system
Granted: September 12, 2000
Patent Number:
6118205
A transducer signal waveshaping system is provided, in which a signal excitation circuit includes a non-linear device. The resulting circuit produces a short input pulse, which allows a piezoelectric transducer to transmit a shortened output signal having distinct waveshape characteristics. The resulting waveshaped output signal, typically an ultrasonic signal, provides a measurable time-dependent signal that is particularly suited for data entry systems, such as for movable transmitter…
Method and computer generated swatch cards for matching colors
Granted: September 5, 2000
Patent Number:
6112665
A blank is provided for producing color swatches on a color printer or photocopier. A sheet adapted to be fed through the printer or photocopier contains a first set of perforations defining the perimeter of a swatch card. A second set of perforations disposed within the perimeter of the swatch card defines a plurality of openings. The openings are punched out, preferably after color swatches have been printed on the swatch card, in order to enable the viewing of a sample color through…
Stylus
Granted: August 29, 2000
Patent Number:
D430206
Command workstation image for a computer display
Granted: June 6, 2000
Patent Number:
D426206
Retrofittable apparatus for converting a substantially planar surface into an electronic data capture device
Granted: May 23, 2000
Patent Number:
6067080
A graphic data-acquisition system which employs an active tracking system provides a retrofittable apparatus for converting a substantially planar surface into an electronic data capture device, in which the components of the system are readily retrofittable, at relatively low cost, to a wide variety of otherwise conventional writing-surface structures, such as so-called dry-erase whiteboards. Conventional triangulation techniques are used to track the position and motion of a writer or…
Interface code architecture
Granted: May 16, 2000
Patent Number:
6065041
A display interface system that uses a server-client approach. The server contains all of the necessary information regarding display information, while the client deals with the specific display type that it is connected to. The server contains generic descriptions of user interface screens which allow the server to be independent of specific display types. This allows one version of software to support many types of displays, rather than several software revisions for each display…
Silicon switch
Granted: April 4, 2000
Patent Number:
6046420
A silicon switch is provided. A silicon member biases a contact into abutment with an opposing contact located on a substrate such that a normally closed switch is provided. A plunger is provided which has an axis that extends along the axis of the two contacts. The plunger is secured by the silicon member in such a way that pressure on the plunger causes the switch contacts to open. When pressure is released, the bias built into the silicon member pushes the contacts back together. The…
Method and apparatus for split printing of color and monochrome documents
Granted: March 21, 2000
Patent Number:
6041200
A system for printing and copying color and black-and-white documents avoids the need for manual collating. The system provides N sets of documents using a printer and a copier, where each set of documents includes a first type of sheets (such as black-and-white sheets), and a second type of sheets (such as color sheets) provided in a particular sequence in relation to the first type of sheets. A first complete document set is printed, including the first and second types of sheets,…
Reduction of banding in printed images
Granted: February 15, 2000
Patent Number:
6025922
A method and apparatus is provided for adding pseudo-random noise and bias to an input pixel value to reduce banding effects and to produce additional highlights in the output. The method adds the value of a bias function and a pseudo-random noise value to the input pixel value. The sum is shifted a predetermined number of spaces. The result of the shifting step is then added to the input pixel value. A predetermined constant is subtracted from the above sum. A clipping procedure is then…
Computer housing
Granted: December 21, 1999
Patent Number:
D417864
Method and apparatus for transforming a source image to an output image
Granted: December 14, 1999
Patent Number:
6002795
The present invention is a method and apparatus for computing color transformations of source images. It performs color transformations using a lookup table and a hashing block for referencing entries in the lookup table. The index generated by the hashing block is dependent on a first color value. A color encoding block is coupled to the lookup table for generating an encoded color value dependent on the first color value. The index produced by the hashing block is further dependent…
Computer icon on a computer monitor
Granted: November 16, 1999
Patent Number:
D416550
Apparatus and method for hybrid compression of raster data
Granted: November 9, 1999
Patent Number:
5982937
From a raster page, patches of connected pixels of the same color are identified. Patches of at least a predetermined sized, typically corresponding to text or line art objects, are subjected to a lossless compression. Patches below the predetermined size, typically corresponding to image or photo objects, are substantially subjected to a lossy compression. The patch predetermined size controls the mix of lossless and lossy compression procedures. Optimum compression is achieved by…
Method and apparatus for data compression and gray value estimation
Granted: October 19, 1999
Patent Number:
5970174
A method and apparatus for compression of data. The invention provides for the application of a plurality of compression schemes to the data such that improved compression ratios are achieved. A first embodiment provides for compression of each pixel by one of a plurality of different entropy-based compression schemes based upon a probability cost analysis. A second embodiment provides for compression of each pixel based on a hybrid context formed using a plurality of compression schemes…
Electrical equipment case
Granted: February 23, 1999
Patent Number:
D406117
