| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a density control technology that enables a density control factor to fall in an appropriate adjustment range and appropriately copes with a great change in image density. <P>SOLUTION: Patch images are formed while setting a development bias to various values (step S11), and the density of each patch image is detected (step S12). Based upon the result of the detection, the optimum value of each development bias at which the image density matches its target density is obtained (step S14). In a case where image density is insufficient even though the development bias is set to various values (step S13), it is determined that the apparatus is in an abnormal state. In the case, an amount of toner remaining in a development vessel calculated by a toner counter is checked (step S15). If the amount of toner remaining is lower than a predetermined value, it is determined that the toner is completely consumed (step S17). If the amount of toner remaining is equal to or larger than the predetermined value, it is determined that the insufficient density is not caused by complete consumption of toner but by an abnormal state of the main body of the apparatus. <P>COPYRIGHT: (C)2004,JPO |
