Semiconductor laser and optical system having a collimator lens

摘要

An optical system includes a semiconductor laser. The semiconductor laser is accommodated within a case. The case is formed with a window to pass through laser light emitted from the semiconductor laser. The laser light passed through the window comes to a collimator lens. Between semiconductor laser and the collimator lens is provided a light shield member having a pinhole to pass through the laser light having passed the window. Laser light made in a parallel luminous flux is outputted from the collimator lens. This laser light is deflected toward a main scanning direction by a deflector and further collected on a scanning surface by a light collector.