Abstract: A printer includes an Application Specific Integrated Circuit (“ASIC”) having an embedded printer controller and an embedded swath buffer for storing complete rows of compressed swath data. The embedded swath buffer may be a fraction of the size of a conventional swath buffer, which is not embedded and which does not store compressed swath data. A printer driver, resident in a host, transmits only complete rows of compressed swath data to the printer.

Abstract: A method and apparatus for manipulating digitized images stored as variable length encoded bitstreams such as JPEG format in a manner that reduces memory and processor resource requirements. A prescan means sequentially decompresses the bitstream to identify the location of encoded pixel image areas. Designated ones of these locations are recorded or stored in a prescan table. After the prescan operation has been performed on the image, image manipulations such as rotating, cropping, and zooming can be performed on a selected portion of the image by directly accessing only the encoded pixel image areas to be manipulated, without the need to sequentially decode and store all the encoded image areas in order to locate the ones of interest.

Abstract: A method and apparatus for controlling firing energy in an inkjet printer are embodied in a control circuit and a regulated pen voltage source for an inkjet printer pen. The control circuit includes switches connected between the nozzle resistors of the pen and a low voltage rail. The control circuit is configured to control the voltages across the switches within a known tolerance, independent of variations in the switch current, integrated circuit process variations, temperature variations, and variations in the resistances of the nozzle resistors. The voltage provided to each nozzle resistor by the pen voltage source is adjusted to compensate for changes in the voltages across the switches.

Abstract: A signaling method for a pen driver circuit interface is embodied in a signal interface between a controller circuit and a pen driver circuit for a printer. At least one signal of the interface is omitted; and the pen driver circuit is modified to process a combination of signals including at least one of the signals on the signal interface to provide information pertaining to the at least one omitted signal. According to a preferred method, the combination of signals are processed when data is not being transferred via the signal interface to provide a pen firing control signal for the printer such as a warm enable signal or a fire enable signal.

Abstract: A method and apparatus for manipulating digitized images stored as variable length encoded bitstreams such as JPEG format in a manner that reduces memory and processor resource requirements. A prescan means sequentially decompresses the bitstream to identify the location of encoded pixel image areas. Designated ones of these locations are recorded or stored in a prescan table. After the prescan operation has been performed on the image, image manipulations such as rotating, cropping, and zooming can be performed on a selected portion of the image by directly accessing only the encoded pixel image areas to be manipulated, without the need to sequentially decode and store all the encoded image areas in order to locate the ones of interest.

Abstract: A method and apparatus for manipulating digitized images stored as variable length encoded bitstreams such as JPEG format in a manner that reduces memory and processor resource requirements. A prescan means sequentially decompresses the bitstream to identify the location of encoded pixel image areas. Designated ones of these locations are recorded or stored in a prescan table. After the prescan operation has been performed on the image, image manipulations such as rotating, cropping, and zooming can be performed on a selected portion of the image by directly accessing only the encoded pixel image areas to be manipulated, without the need to sequentially decode and store all the encoded image areas in order to locate the ones of interest.

Abstract: A signaling method for a pen driver circuit interface is embodied in a signal interface between a controller circuit and a pen driver circuit for a printer. At least one signal of the interface is omitted; and the pen driver circuit is modified to process a combination of signals including at least one of the signals on the signal interface to provide information pertaining to the at least one omitted signal. According to a preferred method, the combination of signals are processed when data is not being transferred via the signal interface to provide a pen firing control signal for the printer such as a warm enable signal or a fire enable signal.

Abstract: An optical encoder provides absolute position information by inducing a position error in its output signal. The position error can be induced in the signal by shifting a slot in an encoder wheel or encoder strip relative to other slots in the encoder wheel. The position error is detected to identify an absolute position of the encoder wheel or the encoder strip.

Abstract: An inkjet printer and method of printing to reduce printer footprint size using printhead service stations comprised of printhead wipers, priming and capping apparatus at each end of the path of travel of a printhead carriage having multiple printheads. Selected printheads are serviced in each service station and selected printheads may be used for printing in opposite directions to further reduce footprint size of the printer.