| 摘要 |
PURPOSE:To provide an image forming device capable of preventing the flickering of a fluorescent lamp and prolonging its life. CONSTITUTION:In the image forming device using the fluorescent lamp 3 as an exposure light source and provided with a photodetecting element (photodetecting means) 31 detecting the light source of the lamp 3, a lighting current control means changing the lighting current of the lamp 3 and a light quantity control plate (light quantity control means) 33 changing the light quantity of an optical system, when the duty ratio of the lighting current of the fluorescent lamp 3 becomes a prescribed value or below, the light quantity of the optical system is reduced by the light quantity control plate 33, to keep the lighting current of the lamp 3 to a prescribed duty ratio or more. Thus, when the lighting current of the lamp 3 is controlled to the prescribed value or below, a part, of the optical system is changed to reduce the light quantity and the lighting current of the lamp 3 is kept to a specific value or above, so that the flickering of the lamp 3 is prevented and simultaneously its life can be prolonged. |
