Dainippon Screen Mfg. Co., Ltd.

Dainippon Screen Manufacturing Co., Ltd.

Kohji Hada

Takumi Yoshida

Tadashi Syudou

An engraving machine for gravure printing to suppress the adverse effect upon the printed image by overshooting of the stylus. The gravure engraving machine has a stylus in an engraving head and controlled by an engraving signal in accordance with an image signal for engraving a surface in a gravure cylinder. An engraving signal generator is provided for generating a carrier signal to drive the stylus, and a modifying signal generator is provided for generating a modifying signal to modify overshoot waveforms caused when the engraving signal is applied to the engraving head. The gravure engraving machine also includes an adder for adding the modifying signal to the engraving signal to modify the engraving signal applied to the engraving head and thereby suppress overshooting of the stylus.

Control circuit for controlling stylus overshoot in an engraving machine

Image data conversion processor converting a raster format of composed image data comprising line-work and picture data into a format of engraving pixel data for realizing a staggered-row screen of gravure printing cells, image density weighted for high-fidelity reproduction of tone value and line sharpness of an originally scanned image pattern. The dual-valued line-work pixels are in high concentration relative to the picture data pixels and are converted into multiple-valued line-work equivalent pixels in a picture-raster equivalent format. The multiple-valued line-work data and the picture data are assembled according to layout data operator controlled through a CRT to form the composed image data for conversion. A format converter in the processor maps the converted multiple-valued line-work equivalent pixels in the picture-raster equivalent format into gravure engraving pixels each corresponding to an engraved gravure cell of the stagger-format printing screen.

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Kyoto, Japan

Kohji Hada