DEVICE AND METHOD FOR MEASURING CONTAMINATION DEGREE OF DEVELOPER SOLUTION FOR PRINTER

摘要

PROBLEM TO BE SOLVED: To make accurately calculable the degree of contamination, to take a proper measure such as replacement of developer when the degree of contamination becomes over an allowable contamination value and to prevent printing quality from being deteriorated by calculating the degree of contamination occurring because another developing substance flows in the developer based on a first light receiving signal and a second light receiving signal outputted from a photodetector. SOLUTION: When a first tube part 41 and a second tube part 42 are irradiated with an identical light quantity concerning the contaminated developer, the quantity of light transmitted through the tubes 41 and 42 are different and the first light receiving signal and the second light receiving signal are outputted as different values. When the concentration value of pure toner respectively estimated based on the first light receiving signal and the second light receiving signal are different, it is recognized that the transmitted light quantity is changed because a contamination substance is mixed in. Besides, a reference table prepared by previously obtaining the concentration value of the pure toner and the degree of contamination corresponding to the values of the first light receiving signal and the second light receiving signal is arranged in a developer contamination measurement part 80. Then, the degree of contamination is calculated by referring the reference table to check to see whether both of the first light receiving signal and the second light receiving signal correspond to the identical concentration value of the pure toner or not.