| 摘要 |
PURPOSE:To stably correct the curvature of image even in the case when a temperature rises in a device by constituting a first image forming optical system of a variable focus liquid crystal lens, and providing a temperature control means for controlling a temperature of this variable focus liquid crystal lens. CONSTITUTION:A first image forming optical system 3 is constituted of a variable focus liquid crystal lens, and also, a temperature control means 7 for controlling a temperature of the variable focus liquid crystal lens is provided, therefore, even if a temperature of a peripheral environment is varied, a focal distance of a first image forming optical system 3 can be varied surely by following up a deflection scan of the deflecting and reflecting surface without being influenced by its temperature variation. Accordingly, the focal distance of a first image forming optical system 3 is varied surely by following up the deflection scan of the deflecting and reflecting surface, and a linear image forming position by a first image forming optical system 3 can be varied on an optical path. In such a way, an image forming position in the sub-scanning direction by a second image forming optical system 5 is varied in conformity with longitudinal magnification of a second image forming optical system 5 in accordance with a variation of the position of the linear image forming part, therefore, the curvature image in the sub-scanning direction can be corrected. |
