| 摘要 |
PURPOSE:To obtain a multibeam condenser to be easily manufactured by forming a composite transparent plate obtained by combining wedge plate parts refracting plural beams individually and a single condenser lens collectively condensing respective beams transmitted through said composite transparent plate. CONSTITUTION:The condenser is constituted of the transparent body 12 consisting of three wedge plate parts transmitting respective beams individually and single condenser lens 13 arranged coaxially with the transparent body 12. The transparent body 12 is a composite body obtained by cutting each wedge plate having a vertical angle psi like a fan with 120 deg. circular measure and joining the three wedge plates at respective cut surfaces and the respective wedge plates are arranged so that the irradiated plural beams are transmitted through the respective wedge plates and refracted in the directions crossing the beams each other. The condenser lens 13 is arranged on a position where the axes 16 of beams 15a-15c refracted by respective sides of the transparent body 12 cross with the center 17 of the condenser lens 13. Therefore, the respective beams 15a-15c are overlapped as one beam on he condenser 13. Said constitution makes it possible to easily obtain a multibeam condenser reducing influences due to the spherical aberration. |
