| 摘要 |
PURPOSE:To eliminate the discrimination error with a simple constitution by setting sides of light receiving faces of line sensors in the arrangement direction to a uniform length and changing the length of sides in the direction orthogonal to the arrangement direction so that outputs of respective picture elements are uniform for an object having a uniform illuminance. CONSTITUTION:Sides of light receiving faces of line sensors 12a and 14a in the arrangement direction of an arrow X of line sensors have the same length, and those in the direction of an arrow Y orthogonal to the direction of the arrow X are changed along a curve corresponding to illuminance distribution. Consequently, sides of light receiving faces of line sensors 12a and 14a in the direction of the arrow Y are shortest at central points K and S and are longer according as going away from central points. The length in the direction of the arrow Y of picture elements arranged in positions where the illuminance on line sensors to the object having a uniform luminance is relatively low is extended to relatively increase the area of light receiving faces, thereby equalizing outputs of picture elements to the same intensity of incident light to one another. |
