| 摘要 |
PURPOSE:To solve several problems caused by the present of particle size distribution of toner. CONSTITUTION:Small particle size toner tends to be first consumed, and accordingly, larger particle size toner largely occupies a small remaining quantity of toner. Accordingly, the remaining quantity of toner in a toner cartridge 13 is monitored by a toner end sensor 3, and the light emitting volume of a laser diode 5 is adjusted by a D/A converter 6, and the diameter of a laser beam is changed by a beam diameter changing means 7 so that the resolution mode is shifted from a high resolution mode (600 dpi) to a low resolution (300 dpi), thereby it is possible to prevent the image quality from lowering due to a high resolution image formation with the use of larger particle size toner. |
