| 摘要 |
PURPOSE:To prevent an erroneous control, by a method wherein, a predetermind calculation is conducted on the basis of the density of a color patch measured by every color, and the calculated value is compared with prestored data for judging whether the color patch is an effective one. CONSTITUTION:In a scanning densitometer, with the rotation of a motor 1, a measuring head 4 held by a guide 5 is traveled right and left and a pulse signal is issued from a rotary encoder 6 according to the travel distance of the measuring head 4. A color bar 9 is printed on a margin part of a printing paper 8 and composed of a large number of color patches 9a, and a host computer part stores the data for the respective patches by evey channel, i.e. Red, Green, and Blue. Therefore, whether the previously stored data per channel coincide with characteristics is discriminated. If it is not coincident, the data is made invalid because of the judgment that a patch absent part has been measured, and a protect is applied to a corresponding ink key. In this manner, the presence of an effective patch can be automatically discriminated, and an erroneous control to an ink key corresponding to an invalid patch can be prevented. |
