| 摘要 |
PURPOSE:To shorten time required for raising the light quantity of a fluorescent lamp to a prescribed one and copying time as well by applying a driving voltage to the fluorescent lamp composing a light source at a specific duty rate when copying operation starts. CONSTITUTION:In an optical system device 11, an optical sensor 2 being a light quantity detecting means is provided below a slit 10 formed on a reflector 8, and detects the light quantity of a copying lamp 1 after receiving light therefrom, which is reflected on a white board 5. Before image scanning starts and until the result detected by the light quantity detecting means 2 reaches a prescribed value, the fluorescent lamp 1 is driven at a 100% duty rate. Therefore, before the fluorescent lamp 1 reaches a prescribed light quantity, prior to starting a copying process, a voltage is applied to the fluorescent lamp 1 continuously. Consequently, the temperature of the fluorescent lamp 1 rapidly rises, whereby time required for reaching the prescribed light quantity after voltage supply to the fluorescent lamp starts, and copying time can be shortened. |
