| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus equipped with a means for detecting failure of a charging roller and informing a user of the timing of replacement of the charging roller, and is free from the problem that, when the detecting means is kept in contact with the charging roller during image formation, a current flows in an image carrier as well as the detecting means, which may lead to degraded efficiency in charging the image carrier and nonuniform charging of the image carrier. <P>SOLUTION: The image forming apparatus includes the means for detecting a leak current of the charging roller 2. The means has a leak current detecting member 8 having a low resistance portion 4 and a high resistance portion 3, and a current detecting section for detecting the value of a current flowing from the charging roller 2 to the leak current detecting member 8. The image forming apparatus is provided with a contact/separation mechanism by which the leak current detecting member 8 is brought into contact with the charging roller 2 and separated therefrom. In addition, the image forming apparatus is provided with a float switch 15, which electrically floats the leak current detecting member 8. <P>COPYRIGHT: (C)2007,JPO&INPIT |
