Method of recognizing color bars on double-sided color prints, color print quality control system and color print quality evaluation apparatus

A double-sided color print quality control system comprising a double-sided color printing press and a color print quality evaluation apparatus,

• said double-sided color printing press including:
• a first printing section that prints on a first side of a substrate a first color print image composed of plural basic different colors and a first color bar for evaluation of the respective plural basic different colors of said first color print image, said first color bar being comprised of at least one first control patch group aligned in a first alignment direction, each of said at least one first control patch group being comprised of plural control patches of plural colors aligned in said first alignment direction respectively corresponding to said plural basic different colors;
• and
• a second printing section that prints on a second side of said substrate a second color image composed of said plural basic different colors and a second color bar for evaluation of the respective plural basic different colors of said second color print image, said second color bar being comprised of at least one second control patch group aligned in a second alignment direction different from said first alignment direction, each of said at least one second control patch group being comprised of plural control patches of plural colors aligned in said second alignment direction respectively corresponding to said plural basic different colors;
• said color print quality evaluation apparatus including:
• an evaluation member that scans said at least one first control patch group in a scanning direction identical to said first alignment direction, scans said at least one second control patch group in a scanning direction identical to said second alignment direction, thereby evaluating the print quality of said plural control patches of said at least one first control patch group and evaluating the print quality of said plural control patches of said at least one second control patch group;
• a detection means for acquiring alignment information of said plural control patches of at least one of said at least one first control patch group and said at least one second control patch group scanned by said evaluation member;
• and
• a recognition means for recognizing whether said first and second color bars each have been printed on said first side or second side of said double-sided color print based on said alignment information of said plural control patches acquired by said detection means.

A color print quality evaluation apparatus for evaluation the print quality of plural control patches printed by a double-sided color printing press that includes a first printing section and a second printing section, in which a first color print image composed of plural basic different colors and a first color bar for evaluation of the respective plural basic different colors of said first color print image are printed by said first printing section on a first side of a substrate, said first color bar being comprised of at least one first control patch group aligned in a first alignment direction, each of said at least one first control patch group being comprised of plural control patches of plural colors aligned in said first alignment direction respectively corresponding to said plural basic different colors, and a second color image composed of said plural basic different colors and a second color bar for evaluation of the respective plural basic different colors of said second color print image are printed by a second printing section on a second side of said substrate, said second color bar being comprised of at least one second control patch group aligned in a second alignment direction different from said first alignment direction, each of said at least one second control patch group being comprised of plural control patches of plural colors aligned in said second alignment direction respectively corresponding to said plural basic different colors, said color print quality evaluation apparatus comprising:

• an evaluation member that scans said at least one first control patch group in a scanning direction identical to said first alignment direction, scans said at least one second control patch group in a scanning direction identical to said second alignment direction, thereby evaluating the print quality of said plural control patches of said at least one first control patch group and evaluating the print quality of said plural control patches of said at least one second control patch group;
• a detection means for acquiring alignment information of said plural control patches of at least one of said at least one first control patch group and said at least one second control patch group scanned by said evaluation member;
• and
• a recognition means for recognizing whether said first and second color bars each have been printed on said first side or second side of said double-sided color print based on said alignment information of said plural control patches acquired by said detection means.

A color print quality control system comprising:

• a color printing press that includes a printing part that prints a color print image composed of plural basic different colors and a color bar for evaluation of the respective plural basic different colors on at least one side of each of substrates transferred in a given transfer direction by an ink fountain for said plural basic different colors, said ink fountain being equipped with 1st to Mth (M is an integer of 2 or larger) ink fountain keys aligned in an alignment direction crossing substantially at right angle to said transfer direction, said color bar being comprised of 1st to Mth control patch groups each comprised of control patches of plural colors aligned in said alignment direction respectively corresponding to said 1st to Mth ink fountain keys, and a print control part that adjusts the amounts of inks set by said 1st to Mth ink fountain keys based on print quality information of the control patches of said 1st to Mth patch groups;
• and
• a color print quality evaluation apparatus that includes a memory means for previously storing alignment information regarding said alignment direction of said plural control patches of said 1st to Mth control patch groups, an evaluation member that scans said 1st to Mth patch groups printed on said each of substrates by said color printing press and evaluates the print quality of the control patches of said scanned patch groups, a detection means for acquiring alignment information of the patches of at least one of said 1st to Mth patch groups scanned by said evaluation member, and a recognition means for recognizing said alignment information of the control patches in said at least one of said 1st to Mth patch groups;
• wherein said recognition means of said color print quality evaluation apparatus compares said alignment information of the control patches acquired by said detection means with said alignment information of the control patches previously stored in said memory means, so that where they are matched to one another, said recognition means recognizes that said patch groups have been scanned in the order from the 1st to Mth patch groups by said evaluation member and transmits print quality information of the control patches of the respective patch groups evaluated by said evaluation member in the order in which said patch groups have been scanned in said scanning direction, and where they are not matched, said recognition means recognizes that said patch groups have been scanned in the order from the Mth to 1st patch groups by said evaluation member and transmits print quality information of the control patches of the respective patch groups evaluated by said evaluation member in the order reversed relative to said scanning direction;
• and
• wherein said print control part of said color printing press adjusts the amounts of inks set by said 1st to Mth ink fountain keys, based on said ink quality information in the order in which they are transmitted from said evaluation member of said color print quality evaluation apparatus.