Ikegami Tsushinki Co., Ltd.

Dai Nippon Printing Co., Ltd.

Takeshi Sasaoka

Satoru Horiguchi

Koichi Shimane

Tsuguo Yaguchi

Kazuhiko Sano

Shigeru Mogi

A color image pickup apparatus has one line sensor which sequentially reads a document through different color filters to generate different color signals. Either the line sensor or the document is mechanically moved in a sub-scanning direction by a mechanical device. A rotary encoder coupled to the mechanical device generates pickup pulses which drive the line sensor each time the line sensor or document is moved a predetermined distance. In an alternate embodiment, two or more line sensors having different color filters each read a different line on the document to generate different color signals having shifted timings. Frame memories, shift registers, memories with a capacity of a plurality of lines, or buffer registers may be used to correct for the shifted timings of the color signals.

Color image pickup apparatus having one or more line sensors and a

An apparatus for simulating a color printing process comprises a scanning unit including a table on which four color separation films formed from a color original are placed side by side, a pair of flying spot scanner tubes, four lens systems for projecting raster images of the scanner tubes onto the four color separation films and four photomultipliers for converting light rays passing through the respective films into subtractive primary color signals of cyan, magenta, yellow and black; a control unit for effecting various adjustments and correction upon the color signals and including a zero adjuster, an after image corrector, a continuous tone gamma corrector, a screen gamma corrector, a soft/hard corrector, a negative/positive corrector, a flat etching device, a contrast adjuster, a light adjuster, a shadow adjuster and a partial adjuster; a color reproduction process unit for converting the adjusted and corrected subtractive primary color signals into additive primary color image signals of red, green and blue; and a color monitor unit for receiving the additive primary color image signals and including a color cathode ray tube for displaying a color image. The color cathode ray tube has a chrominance characteristic which can completely display the actual printing colors and has about 700 to 800 scanning lines per frame.

Apparatus for simulating color printing process

A flying spot scanner for use in a color printing process simulating apparatus for scanning yellow, magenta, cyan and black separation films formed from a color original a color image of which is to be displayed on a color monitor. The flying spot scanner comprises a flat stage having rectangular transparent sections arranged side by side with their long sides adjacent to each other for receiving the color separation films; first and second cathode ray tubes for producing first and second scanning rasters, respectively arranged above the middle point of the first and second films and the middle point of the third and fourth films, respectively; first and second lens systems for projecting images of the first scanning raster produced on the first cathode ray tube onto the first and second color separation films, respectively; and third and fourth lens systems for projecting images of the second scanning raster of the second cathode ray tube onto the third and fourth color separation films, respectively. By driving the first and second flying spot tubes in synchronism with each other, the four color separation films are simultaneously scanned with rasters having very small distortional errors.

Flying spot scanner for use in a color printing process simulating

In a color reproduction method for reproducing a color image on a color monitor screen by processing primary color signals of cyan, magenta, yellow and black which are derived by scanning color separation films of cyan, magenta, yellow and black, respectively, on the basis of the Neugebauer equations, at first the primary color signals of cyan, magenta and yellow are processed in accordance with specially derived color reproduction equations representing halftone of three additive primary colors of red, green and blue to produce three secondary color signals and a tertiary color signal, and then amplitudes of a paper color signal, the primary color signals, the secondary color signals, the tertiary color signal and the primary color signal of black are adjusted in this order independently from each other. An apparatus for carrying out the above color reproduction method comprises seven multipliers, four inverters and twenty seven variable resistors and by suitably adjusting the variable resistors the colors of the image displayed on the color monitor can be controlled.

Growing community of inventors

Kawasaki, Japan

Takeshi Sasaoka