A printhead controller controls printing of a page by at least one printhead. The printhead controller is connected, in use, via a data communications link to a printer controller for receiving data, in a compressed format relating to the page to be printed, the data including a page description comprising a bi-level black layer and a contone color layer. The printhead controller includes a first decoder for expanding compressed data relating to the bi-level black layer and a second decoder for expanding compressed data relating to the contone color layer. The first and second decoders are arranged in parallel. First and second temporary storage devices are provided for storing the expanded data from the first and second decoders, respectively. A data manipulating unit manipulates the data output from these temporary storage devices to be fed to the printhead. A printhead interface is provided at an output from the data manipulator for controlling at least one printhead connectable to the interface and for feeding the manipulated data to the printhead.
Where the bandwidth of a data link between a printer and a computer is limited it may be desirable to transmit compressed page layout data over the data link.A printer controller chip is provided that processes compressed page layout data corresponding to a page layout having a bi-level black layer and a continuous tone graphics layer. The printer controller includes a number of functional modules including an edge delta runlength (EDRL) expander to derive bi-level black layer data from the compressed data. The controller also incorporates a JPEG decoder to derive continuous tone layer data from the compressed data. A halftoner and compositer module is provided to halftone the continuous tone data to bi-level CMYK data and to composite the bi-level layout data over the bi-level CMYK data to produce page layout print data. A printhead interface processes the page layout print data to generate signals to drive a pagewidth printhead.
A printer controller configured to generate dot data for supply to a printhead that includes at least first and second longitudinally extending printhead chips that are positioned adjacent each other either side of a join region such that a printing width of the printhead is wider than the length of either printhead chip, the printer controller being configured such that, in the event that the printhead chips to which dot data is being supplied are of sufficiently unequal relative length, the dot data is supplied more frequently, or at a higher rate, to the longer of the two printhead chips.
A printer controller configured to generate dot data for supply to a printhead which includes at least a first printhead integrated circuit and a second printhead integrated circuit positioned adjacent each other either side of a join region, the printer controller configured to transfer dot data to each of the first printhead integrated circuit and the second printhead integrated circuit at a rate proportional to the relative lengths of the first printhead integrated circuit and the second printhead integrated circuit.
An inkjet printer controller includes a processor for receiving incoming data relating to a description of a page to be printed. A memory in the form of a hard disk, in which the data are stored, is connected to the processor. The controller includes at least one raster image processor for rasterizing and compressing the data. The page data has image data and text data. The text data is compressed separately from the image data. A printhead controller receives, decompresses and processes the data for printing via a printhead under control of the printhead controller.
The present invention relates to a print engine for enabling double sided printing of a sheet of paper. The print engine includes a pair of opposed printhead assemblies for each ejecting ink. In addition the print engine includes a pair of rollers for drawing the paper between the printhead assemblies. Double sided printing of the paper is effected when the rollers draw the paper between the printhead assemblies and the printhead assemblies each eject ink onto opposing sides of the paper.
