| 摘要 |
PURPOSE:To expand lighting range with a simple construction as compared to lighting optical systems of conventional endscopes by letting the exit end faces of photoconductive fiber bundles be tapered end faces. CONSTITUTION:The observation optical system consists of an objective lens 1 and an image transmitting optical fiber bundle 2. As lighting optical systems, photoconductive fiber bundles 3 and 4 parallel disposed by leaving a specified spacing. The exit end faces 3a, 4a of these photoconductive fiber bundles 3, 4 are formed by cutting with, e.g., a grindstone for rotary cutting or polishing so that they beomce tapered faces symmetrical toward the central axis of the endscope as illustrated. The lighting optical systems of the endscope constituted in this way provides the expansion range of lighting light and distributed light distribution as shown by solid lines while the expansion of conventional lighting light is within the range shown by dot-dash lines and assumes the distributed light distribution as shown by dot-dash lines wherein the axis of abscissa is angle and the axis of ordinate is brightness, with respect to the object to be lighted 0. |
