Patent ID: 6559969
Filing Date: 2003-05-06
Classification: B41J,G06F,G06K,H04N

Abstract:
A printhead controller for controlling printing of a page by at least one printhead, the printhead controller being 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 including:a first decoding means for expanding compressed data relating to the bi-level black layer, a second decoding means for expanding compressed data relating to the contone color layer, the first and second decoding means being arranged in parallel; a first temporary storage device for storing the expanded data from the first decoding means; a second temporary storage device for storing the expanded data from the second decoding means; a data manipulating means for manipulating the data output from the fast and second temporary storage devices to be fed to the printhead, the data manipulating means including a ditherer/compositor unit operable to dither the color layer and composite the bi-level black layer on the color layer after dithering thereof; and a printhead interface at an output from the data manipulating means for controlling at least one printhead connectable to the interface and for feeding the manipulated data to the printhead.