Patent ID: 6288819
Filing Date: 2001-09-11
Classification: G02B,Y10S

Abstract:
An apparatus comprising:a light source for outputting light;a first lens system arranged to receive the light output from the light source and to transmit a light flux therefrom;an optical deflector arranged to receive the light flux from the first lens system and to deflect the light flux from a surface therefrom; anda second lens system arranged to receive the light flux deflected from the optical deflector and to condense the deflected luminous flux into an optical beam spot on a surface to be scanned so as to form images having image heights, the luminous flux condensed by the second lens system into the optical beam spot including an optical beam waist, the second lens system including a scanning and image forming element including at least one surface including a plurality of portions each having a non-arc shape in a sub-scanning direction such that a beam waist of the entire luminous flux is located at a surface to be scanned for all image heights.