| 摘要 |
PURPOSE:To eliminate the need for a special mechanism and a sensor for toner concentration detection by comparing the light reflectance of the toner image of a reference density pattern formed on a photosensitive body before toner supply with that after the toner supply and deciding whether or not there is supply toner from the comparison of results. CONSTITUTION:The light reflectance of the visible image of the reference density pattern formed on a charge carrier and the supply of toner is controlled based on the detection result. Namely, the latest eight past sampling data in a buffer register are utilized to compute their mean value, which is stored as a Vsp mean value in a register Mvsp and also stored in a prescribed register for display. Then, the contents of the register Mvsp are compared with a fixed value (Vem). The Vem is set at a relatively high level as compared with the normal level of Vsp. Therefore, Mvsp<Vem unless there is special abnormality, so toner supply control is carried out. |
