| 摘要 |
PURPOSE: To completely compensate a straight advancing error over the full scanning distance by twisting a concave mirror based on a function defined concerning an axis extended in the direction of a strip. CONSTITUTION: Light flux 18 from a light source 14 is reflected by a rotary mirror 12, which is driven by a motor 16, and flooded 19 onto a concave mirror 10 in the form of strip and a scanning beam 20 is generated and sent to an optical receiver. Concerning an axis S extended in the lengthwise direction of strip, the respective sections of the mirror 10 to be irradiated during the full scanning term of beam 19 (19') are twisted so as to form the same anglesβ3 andβ' to the beam 19 (19') within one plane vertical to a total scanning direction (scanning plane). That twisting angleΔαis determined corresponding to a height Hi measured in the lengthwise direction of strip, the relevant surface part is always set at the same angle to the optical axis, and a reflected beam 20 (20') is independently reflected at the same angle to the height Hi. |
