| 摘要 |
PURPOSE:To extend the life of each laser by constituting the titled device so that the surface of a photosensitive body corresponding to a non-recording area is exposed by optical beam scanning from the laser which has been provided separately. CONSTITUTION:An optical unit 20 is provided with an image write semiconductor laser 1L, and a blank exposure (exposure to a non-recording area) semiconductor laser 2L, and light emitted from each laser 1L, 2L passes through image forming lens groups 1C, 1T and 1F, is reflected by a turning-back mirror 1M, and a spot is formed on a photosensitive drum. In this state, after a rotation of the photosensitive drum has been started, primary electrification is started, the laser 2L waits for a rise of a rotation of a scanner motor and emits light, and by its optical beam scan, the potential of an electrified part of the photosensitive drum surface is attenuated. Subsequently, an image signal is inputted, and when the laser 1L starts to emit light, the laser 2L is turned off, and in the image recording area, only the laser 1L is lighted. Next, between sheets, the laser 2L is lighted, and the laser 1L is turned off. In this way, the life of each laser 1L, 2L can be extended. |
