Patent ID: 6326609
Filing Date: 2001-12-04
Classification: B41J,G02B

Abstract:
A scanning drawing apparatus comprising:a light source for emitting a laser beam;a beam separator for dividing said laser beam from said light source into a drawing beam and a monitor beam;a drawing optical path through which said drawing beam travels;a monitor optical path through which said monitor beam travels, said monitor optical path having a different optical path length from said drawing optical path;a beam combiner for combining said drawing beam from said drawing optical path and said monitor beam from said monitor optical path;a scanning deflector for deflecting said drawing beam and said monitor beam combined by said beam combiner; anda scanning lens for converging said drawing beam and said monitor beam deflected by said scanning deflector to form beam spots on an image surface and a monitor scale, respectively, said monitor scale being located at a position equivalent to said image surface;wherein a deviation of the beam spot of said drawing beam on said image surface due to an inclination or a shift of said light source is coincident with a deviation of the beam spot of said monitor beam on said monitor scale in terms of directions and amounts.