Dampening water feeding method for a printing machine, and the printing machine
AssigneeDainippon Screen Mfg. Co., Ltd.
InventorsTakaharu Yamamoto, Kazuki Fukui, Tuyoshi Okuda
Life of this patent
Estimating the term…
Abstract
A color density measuring step is executed for measuring color densities of unprinted areas on prints. Then, a determining step is executed for determining from the color densities of the unprinted areas on the prints whether ink tinting has occurred. When the determining step determines that ink tinting has occurred, a dampening water adjusting step is executed for adjusting a dampening water feeding rate after feeding dampening water in an increased rate once. A variation in the ink feeding rate is prohibited for a predetermined waiting time after feeding dampening water in the increased rate once in the dampening water adjusting step.
Claims9
A dampening water feeding method for a printing machine that controls an ink feeding rate and a dampening water feeding rate by measuring, with color density measuring means, color density of prints produced, said method comprising:
- a color density measuring step for measuring color densities of unprinted areas on prints with said color density measuring means;
- a determining step for determining from the color densities obtained in said color density measuring step whether ink tinting has occurred;
- and
- a dampening water adjusting step for adjusting the dampening water feeding rate when said determining step determines that ink tinting has occurred, wherein
- said dampening water adjusting step includes
- a step of forcibly feeding the dampening water with a temporarily increased rate, and thereafter
- a step of feeding the dampening water with a rate lower than the temporarily increased rate and higher than a rate prior to the step of forcibly feeding the dampening water.
A printing machine comprising:
- color density measuring means for measuring color densities of unprinted areas on prints;
- dampening water feeding means for adjusting a dampening water feeding rate to be fed to a printing plate;
- and
- control means for determining from the color densities measured by said color density measuring means whether ink tinting has occurred, and adjusting a dampening water feeding rate by said dampening water feeding means when ink tinting is determined to have occurred, wherein
- said control means executes
- a step of forcibly feeding the dampening water with a temporarily increased rate, and thereafter
- a step of feeding the dampening water with a rate lower than the temporarily increased rate and higher than a rate prior to the step of forcibly feeding the dampening water.
Dependencies are inferred from the claim text.