LIQUID CONCENTRATION DETECTOR AND IMAGE FORMING APPARATUS

PROBLEM TO BE SOLVED: To provide a liquid concentration detector capable of exactly detecting a liquid concentration by using an optical sensor even if an unexpected fluctuation in the thickness of a liquid film occurs and an image forming apparatus having such liquid concentration detector. SOLUTION: A film thickness detection sensor 50 detects the film thickness of the thin developer layer formed on a liquid carrying roller 41 at least at every timing of the liquid concentration detection by an optical sensor 45. Further, if the result of the detection of the film thickness is different from the preset film thickness of the thin developer layer (hereafter described as the set film thickness value), the detected value is corrected by a means for correcting the detected value of the liquid concentration. The means for correcting the detected value of the liquid concentration corrects the resulted analog value of the optical sensor to a correct concentration by comparing the value with the value of the actual film thickness. COPYRIGHT: (C)2004,JPO