| 摘要 |
PURPOSE:To evenly cover the entire scan lighting area without a larger structure by making up for light distribution characteristics of an output light with a light distribution correcting plate arranged in front of a cylindrical lens. CONSTITUTION:An output light of a laser 1 is intermittently broken with an optical switch 2, magnified with a lens 3, and then, made up for light distribution characteristics such as shape and intensity distribution with a light distribution correcting plate 9 having a window adapted to maximize the quantity of light broken at the center thereof arranged in front of a cylindrical lens 10. This prevents uneven intensity of lumination--light at the center but gradually darker toward the circumference--owing to effect of the laser 1, focusing action of the lens 10 and the like while permitting the irradiation area to be adjusted so freely that the sean lighting area can be covered efficiently without use of any large area light unavoidably large in the dead area. As a result, a pulse lighting apparatus for a printed circuit board inspection system is obtained which is capable of covering the scan lighting area evenly without a larger construction. |
