Printing press equipped with color chart measuring apparatus

A printing press for printing a color chart having a plurality of color chart fields in a margin of printing paper, said printing press equipped with a color chart measuring apparatus for reading each of said color chart fields on said printing paper to measure color chart information,

• said printing press comprising:
• a measuring area setting section for determining an area in which said color chart is located on said printing paper as a measuring area;
• a paper stack section for stacking said printing paper printed;
• a rough positioning section for roughly positioning said printing paper stacked in said paper stack section;
• an imaging section for reading an image on said printing paper;
• an image data storage section for storing, out of readout image data obtained by said imaging section, at least readout image data on an area determined by said measuring area setting section;
• a color chart actual position calculation section for calculating an actual position of each of said color chart fields on the basis of said readout image data;
• and
• a color chart information determination section for determining said color chart information about each of said color chart fields from said readout image data corresponding to said actual position.

A printing press for doing printing using a printing plate on which an image is recorded, said printing press comprising:

• a color chart data storage section for storing color chart data representing a color chart;
• a color chart data adding section for adding said color chart data to print image data;
• a printing plate recording section for recording said image on said printing plate on the basis of said print image data obtained by the addition of said color chart data;
• a color chart position computation section for computing a position to which said color chart data was added;
• a printing section for printing a print image and said color chart on printing paper by using said printing plate;
• an image data acquisition section for acquiring image data on an area including said color chart on said printing paper on the basis of said position to which said color chart data was added;
• and
• a color chart information determination section for determining color chart information about each of color chart fields in said color chart on the basis of said image data.

A color chart measuring apparatus for capturing an image on printing paper on which a color chart having a plurality of color chart fields was printed and measuring color chart information,

• said measuring apparatus comprising:
• an imaging section for reading an image on said printing paper being transported;
• a reading time setting section for determining, in accordance with a transport operation of said printing paper, a reading time during which said imaging section reads an image of said color chart;
• an image data storage section for storing image data on an area read by said imaging section during said reading time, as readout image data;
• a color chart actual position calculation section for calculating an actual position in which each of said color chart fields was actually printed, on the basis of said readout image data;
• and
• a color chart information determination section for determining said color chart information about each of said color chart fields from said readout image data corresponding to said actual position.

A color chart measuring method for use in a printing process for recording a print image and a color chart having a plurality of color chart fields on a printing plate and printing said color chart in a margin of printing paper by using said printing plate,

• said measuring method comprising the steps of:
• computing a position of said color chart relative to said print image;
• determining an area to capture an image of said color chart on the basis of said position of said color chart;
• imaging said area on said printing paper;
• storing readout image data obtained through imaging;
• computing an actual position of each of said color chart fields from said readout image data;
• and
• determining color chart information on the basis of said readout image data corresponding to said actual position.

A color chart measuring method for use in a printing process for recording a print image and a color chart having a plurality of color chart fields on a printing plate and printing said color chart in a margin of said printing paper by using said printing plate,

• said measuring method comprising the steps of:
• computing a position of said color chart relative to said print image;
• capturing an image on said printing plate;
• determining an area in which said color chart is located, on the basis of said position of said color chart;
• out of readout image data obtained through imaging, specifying readout image data on said area in which said color chart is located;
• computing an actual position of each of said color chart fields on the basis of said specified readout image data;
• and
• determining color chart information from said readout image data corresponding to said actual position.

A color chart measuring apparatus installed in a printing press for doing multicolor printing on printing paper, said measuring apparatus capturing an image of a color chart having a plurality of color chart fields on said printing paper and measuring color chart information on the basis of image data obtained through imaging, said measuring apparatus comprising:

• an imaging section for reading an image including said color chart and an unprinted area in the close vicinity of said color chart on said printing paper being transported;
• a computation section for computing color data on each of said color chart fields and white color data on an unprinted area in the vicinity of each of said color chart fields from said image data obtained through imaging by said imaging section;
• and
• a white color correction section for correcting said color data using corresponding one of white color data.

A color chart provided along a width of printing paper for checking at least an ink density in a printing press,

• said color chart including:
• at least two reference marks provided at a predetermined distance from each other in a direction of a print span;
• and
• a plurality of kinds of color chart fields arranged in line between said reference marks,
• wherein said reference marks each have a pattern to indicate positions of said color chart fields with respect to a print direction.