| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus designed to prevent erroneous detection of a belt mark formed on an endless moving body. <P>SOLUTION: A belt mark sensor 30 is provided with an LED 51, a PD 52, a comparator 53, a light emission quantitative adjustment circuit 54, a receiving light quantitative adjustment circuit 55, a detection threshold level adjustment circuit 56, a hysteresis adjustment circuit 57, and a noise entry prevention resistance 58. If a defect in a belt mark pulse is detected, a quantity of light or a threshold level is adjusted using the light emission quantitative adjustment circuit 54, the receiving light quantitative adjustment circuit 55, and a detection threshold level adjustment circuit 56. Thereby a digital waveform changed to a binary form is adjusted and the defection in the belt mark pulse is eliminated. <P>COPYRIGHT: (C)2007,JPO&INPIT |
