Abstract: A means for determining the voltage of a power source is disclosed. A portion of the available power from the power source is applied to a heating element. By measuring a rate of change in the temperature of the heating element the input voltage can be determined.

Abstract: An image forming device having a fast draft mode accomplished by speeding up the media through the image forming device but not changing the image data rate. The image data is scaled to compensate for the increased media speed. The image data may also undergo enhancement processes to increase the quality of the printed image.

Abstract: There is disclosed a wired-AND bus emulator circuit that allows any node to prevent propagation of information through the node. A controller can command all other controllers on the bus to break the bus thereby allowing the controller to determine the topology and possibly dynamically program the address of each controller on the bus. By allowing a controller to determine the bus topology, and possibly program the address of each other controller, the bus designer can configure the bus in a topology that is physically convenient. Additionally, the installer is not required to program each node with a unique address.

Abstract: A compression system stores meta-data in the compressed record to allow better access and manage merging data. Markers are added to the compression stream to indicate various things. Each compressed record has a marker to indicate the start of the compressed data. These markers have sector number as well as the relocation block numbers embedded in their data. A second marker is used to indicate free space. When compressed data is stored on the disk drive, free space is reserved so that future compression of the same, or modified, data has the ability to expand slightly without causing the data to be written to a different location. Also the compressed data can shrink and the remaining space can be filled in with this free space marker. A third type of marker is the format pattern marker. Compression algorithms generally compress the format pattern very tightly. However, the expectation is that the host will write useful data to the storage device.

Abstract: Raster images are highly compressed by first reordering the data. Next the reordered data is indexed to encode any and all predicted runs and literal runs. Each piece of the present line of the raster image is compared to a previous line. If there is a match, then the present piece is a predicted run and indexed accordingly. If there is no match, then the present piece is a literal run and indexed accordingly. A predicted run can have a minimum run length of one piece, and a maximum run length of the image width in pieces divided by the number of strings. The same is true for literal runs. The index strings are then compressed using a lossless compression method such as Huffman encoding. If Huffman encoding is used, the Huffman tables are predefined and known to both the compressor and decompressor. As the compressor compressed the index strings, the Huffman tables are adapted. The decompressor is notified by the compressor when the adapted tables are to be used.

Abstract: New consumables installed in printing devices sometimes must print several pages to “condition” the consumable before use. This “conditioning” is required to allow various components to reach optimal condition for printing. The present invention seeks to ameliorate the situation of changes in a consumable affecting the print quality by modifying the printing behavior based on measurements made on the consumable or on the history of the consumable which is installed. If necessary, the new consumable is pre-conditioned before additional page are printed. Pre-conditioning is accomplished by printing either several test pages or by developing several images and subsequently cleaning these images into the waste toner hopper.

Abstract: There is described a method for determining the relative location between a rectangle and a polygon. First, a box that bounds the polygon is created. An outside indicator is returned if the rectangle is outside the box. An intersect indicator is returned if the box is entirely inside the rectangle. If an odd/even fill process is in use then first the intersect indicator is returned if the rectangle intersects with the polygon or if a subpath bounding box is entirely inside the rectangle. Finally, if the location of the rectangle has not yet been returned, the location of a single point of the rectangle is returned. If a non-zero winding fill process is in use, first, the intersect indicator is returned if at least one corner of the rectangle is in a different side of the polygon than remaining corners of the rectangle.

Abstract: The present invention reduces the amount of data sent to a printer from a printer driver. Data reduction is achieved by using a dither matrix that is designed to produce compressible images, then using a lossless compression scheme that matches the dither matrix.

Abstract: When the media enters the fuser, the added thermal load causes the fuser temperature to dip. Eventually, the control system compensates for the thermal load and stabilizes the fuser temperature at the desired temperature. Depending on several factors, the dip in fusing temperature may cause a degradation in the fusing process. An improved temperature profile can be achieved by increasing the amount of power supplied to the fusing system a predetermined amount of time before the thermal load enters the fusing system. Similarly, the amount of power supplied to the fusing system is decreased a predetermined amount of time before the thermal load exits the fusing system. The Desired Temperature input to the fuser temperature control system is modified to anticipate changes in thermal loads thereby changing the amount of power supplied to the fusing system.

Abstract: A method and apparatus for clipping a objects against a non-rectangular polygon. The present invention first defines a rectangular buffer with a height and width equal to the maximum height and width of the non-rectangular polygon. Next, each object is clipped against the rectangular buffer using a fast rectangular clipping method. After all the objects have been clipped, the rectangular buffer is converted to a pattern buffer. Finally, the pattern buffer is clipped against the non-rectangular polygon using an arbitrary clipping method.

Abstract: A quick cooling air conditioning system that preserves high pressure refrigerant, in a portion of the refrigerant path or in a dedicated reservoir, after the shutdown of the air conditioning compressor. The quick air cooling is achieved by the instant application of high pressure refrigerant to the evaporator at the start-up of the air conditioning system.

Abstract: The present invention provides a circuit for heating a heating element to a desired temperature and generating an output from a single common AC power source. First, the AC power is rectified. An inductor and a capacitor form an L section type filter for the DC from the rectifier. The inductor and the capacitor have a resonate frequency that is greater than the AC power frequency. A switch is connected to the heating element. Next, a controller receives a signal that indicates the actual temperature of the heating element along with an indication of the desired temperature. The controller generates an error signal that PWMs the switch thereby controlling the heating element. Another switch is connected to a transformer. A separate controller PWMs the second switch generating the output at the secondary side of the transformer. The two controllers use a pulse width modulating frequency that is greater than the resonate frequency of the inductor and capacitor.

Abstract: The present invention provides a method for compressing image data. The method first detects a pattern in a first subset of the image data, where the second subset being collocated to a second subset. If no pattern is detected, then a text mode context model is selected. If a pattern is detected, then the period of the pattern is detected and a pattern mode context model is selected. The pattern mode context model has a width directly related to the period of the pattern detected. An arithmetic compressor compresses the second subset using the selected context model.

Abstract: The present invention provides improved compression ratios for small data sets with only a minor impact of the compression ration of larger data sets by rapidly tracking the statistics at the beginning of the compression run, slowing down to a traditional pace as the size increases. This is accomplished by limiting the size of the probability table at the start. As more data passes through the compressor, the size of the table is expanded. The size of the probability is controlled by gradually opening the context window for limited number of bytes at the beginning of the data set.

Abstract: The present invention provides improved compression ratios for small data sets with only a minor impact of the compression ration of larger data sets by selecting a context model optimized for the size of the data set being processed. The size of the original data is determined. Based on the size, a context model is selected. The original data is compressed into the compressed data using the context model. Any number of context models may be defined and appropriate values chosen. To decompress, it is necessary to select a context model based on the size of the original data. Two ways of detecting the correct context model are described. First, the size of the original data is part of the compressed data. Alternatively, an indicator, identifying which context model was used to compress the original data, is part the compressed data.

Abstract: The present invention looks for large regions of white or black pixels. In those regions, it is very likely the next few pixels will continue to be the same all white/black value. The present invention replaces the actual encoding of those pixels with whether or not the multi-bit jump was a success. If the jump was unsuccessful then each of the bits unsuccessfully jumped over is encoded using a predefined location in the probability table.

Abstract: The present invention is a control system for controlling the temperature of the fusing system. This control system utilizes the knowledge of the heating characteristics of the fuser filament along with the knowledge that the human eye is most sensitive to temporal changes near the 8 Hz to 10 Hz rate as well as the concept of shape factors to control the rate at which power is applied to the filament to bring the fusing system up to operating temperature. From the study of the electrical characteristics of the heating element it is known that the heating element resistance in the fusing system under study exhibits a thermal time constant of 330 mS while heating. Also, from the summary of flicker regulations it is known that the best reduction in flicker is for the case in which a ramp voltage change is implemented with a ramp time of at least 1 second.

Abstract: An encoding method that allows the use of previous line data without requiring multiple accesses to the image or the use of a line buffer. The image, which is to be compressed, is divided into columns. Each column is traversed vertically. Each row within a column is compressed by horizontally moving across the row. After a row is compressed the next row in transferred to the compressor. Once a column is compressed, the compressor continues at the top of the next column. This process continues until all the columns have been compressed. By vertically traversing through the image, information about the previous row is limited by the width of the column. This limited storage of the previous row allows use of a two dimensional context model, which greatly increases the compression ratio.

Abstract: The present invention is accomplished by first initializing a plurality of individuals. A trie is constructed for each individual, where the trie represents the original data. The trie comprises a root node, a plurality of sub-nodes and sub-arrays in a hierarchical arrangement. The individual indicates the number of the sub-nodes, sub-arrays and number of entries in each sub-array. Within a trie, delete any sub-array which contains redundant data and remove any of sub-node which contains redundant data. Apply an overlapping reduction function to the trie. With the trie constructed, determine the size for the trie and associate the size to the individual. Select a mating population based on trie size. Choose and perform at least one operation for the mating population, where the operation is the operations of crossover or mutation. For crossover, create at least one new individual by recombining the "genes" of at least two individual from the mating population.

Abstract: In order to accomplish the present invention, there is provided a voltage supply system for use in a color electrophotographic printer where the electrophotographic printer has more than one developer. A high voltage AC source receives a select signal that indicates which one of the developers is presently in use. Provided one and only one developer is in use, the alternating current source outputs an AC voltage. A switching network is connected to the HVAC current source and also each developers. The switching network also receives the select signal and routes the AC voltage to the active developer. Stress to the switching elements in the switching network is reduce by proper sequencing of the application and removal of the HVAC and network reconfigurations.