| 摘要 |
PURPOSE:To eliminate the need for providing a machine plate with a density scale and enable printed density and gradation to be controlled, by providing three sensors comprising a combination of IR sensors for detecting the thickness of an ink film and the thickness of a water film and an IR radiation thermometer for detecting temperature, oppositely to a vibrating roller in an ink roller group. CONSTITUTION:An ink film thickness, water content and temperature sensor 16 comprises a combination of film thickness sensors utilizing the ink-absorbing properties of an ink film and a water film on a vibrating roller 11 and an IR radiation thermometer. By using the sensor 16, the thicknesses of the water film and the ink film are detected, signals of water film thickness W, ink film thickness I and temperature theta are formed through an amplifier 18, and the information is sent to a controller 19. As for printing speed, the rotating speed of an impression cylinder 1 is detected by a detector 26, and a signal of circumferential velocity V is formed, and is sent to the controller 19. Data sampled by the controller 19 are converted into a paper surface density and a water content ratio by calculations, the values thus obtained are compared with values provided in a setter 20, and a water fountain roller driving motor 25 and the opening of an ink key 10 are automatically controlled so that the calculated values come into respective target deviation ranges. |
