| 摘要 |
PURPOSE:To detect accurately a sheet material, which passes a sheet material carrying path, with a sheet material detecting means and make a device compact and simplify the constitution by providing a toner image forming means, the carrying path, a fixing means, an air current forming means, and the sheet material detecting means and providing a switch means in an air current. CONSTITUTION:When upper and lower enclosures 17 and 18 are in the matching state, a space D is formed between a frame plate 32 and a cover 30. Meanwhile, a fan F provided in the side of an optical system member 15 of the upper enclosure 17 and in the end part of the enclosure 17 discharges heat or the like in the device to the outside of the device, and the air in the lower enclosure 18 is flowed in the direction of an arrow E by the fan F and is discharged out of the device through an aperture 321 of the frame plate 32. A photo interrupter switch 22 is cooled by this air current, and the overheat is prevented. The steam generated at the fixing time in a fixing device 10 is flowed out from an aperture 103 of a cover 30 and will be cooled to water drops in the position of the photo interrupter switch 22, but this steam is not cooled into water drops by this air current and is discharged out of the device. |
