| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize exact detection of an abnormal state of an apparatus without increasing processing time, with respect to a technology for controlling image density based upon patch image density detection results. <P>SOLUTION: Among patch images Ip(1) to Ip(6) formed by altering and setting a development bias Vb that is a density control factor, the two patch images Ip (1) and Ip(6) formed with the minimum development bias Vb (1) and the maximum development bias Vb(6), respectively, are used as "patch images for determining an abnormal state". Density differences ΔDv are calculated from the density detection result of them. In the case that the value does not reach a predetermined reference value, it is determined as an error. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
