Abstract:
A reproduction method for continuous tone images on an output device having multilevel capabilities is described. The microdots addressable by the output device are arranged into identical tiles. The microdots in a tile get a sequence number, according to a randomised Bayer pattern for which the runlengths of microdots having low sequence numbers are reduced. The sequence is divided into five subsequences. The microdots belonging to the first three subsequences are changed exclusively to higher density levels for decreasing intensity levels, each within a specific intensity range of the input image. The microdots belonging to the last two subsequences are used to more continuously reproduce the image levels. Equivalent microdots within a tile are further differentiated by a second sequence numbering, in order to ensure smooth and precise average density transitions in reproduced continuous tones.
Abstract:
A light emitting head for use in copiers or printers, the light emitting head having an illuminated length, e.g. a print width or copy width, and including a rigid carrier structure provided from a bulk material that spans at least the illuminated length of the head, the bulk material having a coefficient of thermal conduction larger than 100 W/mK and a coefficient of thermal expansion; a plurality of blocks of light elements arranged in a longitudinal array, the blocks having a coefficient of thermal expansion, each of the blocks of light elements having a first and a second surface, each of the blocks of light elements including a plurality of light-emitting elements exposed on a first surface on the block, the plurality of blocks being physically attached to the carrier structure by a conductive adhesive at substantially the second surfaces, and wherein the bulk material has a coefficient of thermal expansion that differs from the thermal expansion coefficient of the block material by a maximum of 5*10−6/K.
Abstract:
An apparatus and a method are disclosed for digitizing a color negative picture and correcting the image signals in a way that they are linearly related to the luminance of the photographed scene for grey tones in the scene. A second embodiment allows obtaining on the basis of the color-corrected image signals a reproduction of true color of the scene on a color display unit. For determining the correction, use is made of the characteristic system curve indicating for each of the color components the relation between the luminance of a neutral color swatch in the scene and the density sensed by the scan system. Several methods for drafting said system curve are described. Furthermore, the way of obtaining the color-corrected image signals by means of a color transformation and the way of determining the transformation are explained.
Abstract:
A light emitting head for use in copiers or printers, the light emitting head having an illuminated length, e.g. a print width or copy width, and including a rigid carrier structure provided from a bulk material that spans at least the illuminated length of the head, the bulk material having a coefficient of thermal conduction larger than 100 W/mK and a coefficient of thermal expansion; a plurality of blocks of light elements arranged in a longitudinal array, the blocks having a coefficient of thermal expansion, each of the blocks of light elements having a first and a second surface, each of the blocks of light elements including a plurality of light-emitting elements exposed on a first surface on the block, the plurality of blocks being physically attached to the carrier structure by a conductive adhesive at substantially the second surfaces, and wherein the bulk material has a coefficient of thermal expansion that differs from the thermal expansion coefficient of the block material by a maximum of 5*10−6/K.
Abstract:
A method is disclosed for rendering monochrome or colored continuous tone images by a system having restricted continuous tone rendering capabilities, such as electrographic printers capable of printing more than two density levels on each addressable micro dot. A method for preferred halftone dot growth is described, starting from isolated dots arranged along base lines and auxiliary lines, evolving to high density lines along the base lines and approximating full continuous tone rendition for high density regions. Preferred arrangements for the orientation, spacing and absolute location of the base lines and auxiliary lines are disclosed and a method to generate preferred arrangements. A moire free combination of three halftone images is described for the reproduction of color images. A method to select a restricted set of energy levels to obtain linear reflectance response is disclosed. Halftone cells are arranged in supercells to improve the density resolution of the system.
Abstract:
A method is disclosed for rendering monochrome or colored continuous tone images by a system having restricted continuous tone rendering capabilities, such as electrographic printers capable of printing more than two density levels on each addressable micro dot. A method for preferred halftone dot growth is described, starting from isolated dots arranged along base lines and auxiliary lines, evolving to high density lines along the base lines and approximating full continuous tone rendition for high density regions. Preferred arrangements for the orientation, spacing and absolute location of the base lines and auxiliary lines are disclosed and a method to generate preferred arrangements. A moire free combination of three halftone images is described for the reproduction of color images. A method to select a restricted set of energy levels to obtain linear reflectance response is disclosed. Halftone cells are arranged in supercells to improve the density resolution of the system.
Abstract:
A method is disclosed for rendering monochrome or colored continuous tone images by a system having restricted continuous tone rendering capabilities, such as electrographic printers capable of printing more than two density levels on each addressable micro dot. A method for preferred halftone dot growth is described, starting from isolated dots arranged along base lines and auxiliary lines, evolving to high density lines along the base lines and approximating full continuous tone rendition for high density regions. Preferred arrangements for the orientation, spacing and absolute location of the base lines and auxiliary lines are disclosed and a method to generate preferred arrangements. A moire free combination of three halftone images is described for the reproduction of color images. A method to select a restricted set of energy levels to obtain linear reflectance response is disclosed. Halftone cells are arranged in supercells to improve the density resolution of the system.
Abstract:
A method is disclosed for rendering monochrome or colored continuous tone images by a system having restricted continuous tone rendering capabilities, such as electrographic printers capable of printing more than two density levels on each addressable micro dot. A method for preferred halftone dot growth is described, starting from isolated dots arranged along base lines and auxiliary lines, evolving to high density lines along the base lines and approximating full continuous tone rendition for high density regions. Preferred arrangements for the orientation, spacing and absolute location of the base lines and auxiliary lines are disclosed and a method to generate preferred arrangements. A moire free combination of three halftone images is described for the reproduction of color images. A method to select a restricted set of energy levels to obtain linear reflectance response is disclosed. Halftone cells are arranged in supercells to improve the density resolution of the system.
Abstract:
The present invention provides improved electrostatographic single-pass multiple station printers as well as methods of operating the same being able to avoid displacement of different color images by effects of the toner coverage of the printed pages. To obtain this, a main encoder means (50) and a printing medium advancement measurement means (60a) are provided, the main encoder means (50) for producing a first signal (501) indicative of printing medium displacement and the printing medium advancement measurement means (60a) for providing a second signal (601) representative of printing medium advancement. The printing medium advancement measurement means (60a) is adapted to co-operate with the main encoder means (50) for automatic adjustment of said first signal (501) using said second signal (601).
Abstract:
The present invention provides improved electrostatographic single-pass multiple station printers as well as methods of operating the same being able to avoid displacement of different colour images by effects of the toner coverage of the printed pages. To obtain this, a main encoder means (50) and a printing medium advancement measurement means (60a) are provided, the main encoder means (50) for producing a first signal (501) indicative of printing medium displacement and the printing medium advancement measurement means (60a) for providing a second signal (601) representative of printing medium advancement. The printing medium advancement measurement means (60a) is adapted to co-operate with the main encoder means (50) for automatic adjustment of said first signal (501) using said second signal (601).