Patent ID: 9446581
Filing Date: 2016-09-20
CPC Classification: B41F,B41P

Claim Text:
1. An ink supply device of a printing machine, said ink supply device comprising: an ink fountain roller that constitutes an ink fountain; a plurality of ink transfer rollers that are divided in the lengthwise direction of the ink fountain roller and are arranged adjacent to the ink fountain roller; a switching device that individually changes over the respective ink transfer rollers between a transfer position where the ink transfer roller is brought into contact with the ink fountain roller and a non-transfer position where the ink transfer roller is disposed away from the ink fountain roller; and a control device programmed to control supply of a quantity of ink, wherein, based on a graph value set corresponding to a pattern area of a printed matter, a circumferential length of ink transferred to the ink transfer roller from the ink fountain roller is controlled by changing over an energy state of a switching valve of the switching device by the control device, wherein the control device comprises: wherein the concentration prediction value calculation means acquires a prediction value Y at a point of time that the measurement is performed n times by the following formulae, where with a measurement value at n-th time being Xn, an average value of measurement values of n times being Xa, a standard deviation amounting to n times being σ, a deviation value of a measurement value at n-th time being T, and a concentration prediction coefficient being α: wherein, in the above formulae, when n=1 and when the same measurement value is acquired in all measurements performed n times, the graph change value calculation means acquires a graph change value Gs by the following formulae, where with a concentration target value being K, a preset graph value being Gb, a ratio of surplus/shortage of ink being L, and a graph value correction coefficient being β: wherein the control graph value calculation means acquires the control graph value Ga by the following formula: