| 摘要 |
PURPOSE:To increse the quantity of transmitted light by bringing adjacent optical elements into contact with each other without using a spacing tube. CONSTITUTION:Field lenses 11, parallel plane glass blocks 13 and an image forming lens 12 are arranged in an optical tube 14 in a state where all of the adjacent convexes and planes such as both convexes 11a, 11b of each lens 11 and one side 13a of each block 13 adjacent to the lens 11, and both convexes 12, 12b of the lens 12 and one side 13a or 13b of each block 13 adjacent to the lens 12 are in contact with each other in the vicinity of the optical axes. The glass blocks 13 correct the astigmatism and increase the brightness of an image. |
