| 摘要 |
PURPOSE:To obtain a light flux divider having an optional light flux dividing ratio by adjusting the dividing ratio by using the area ratio of an incident area of light flux to an exit pupil. CONSTITUTION:A straight line 6 passing through the center 0 of an exit pupil 5 of an image formation lens 1 is regarded an approximate border, the exit pupil 5 is divided into two areas 5a, 5b and photodetector arrays 2, a dividing lens 3 and a phase plate 4 are aligned to the straight line 6 in the longitudinal direction. The light flux passing through one area 5a out of the areas 5a, 5b divided by the straight line 6 of the exit pupil 5 of the image formation lens 1 is made incident into a photodetector 2b1 e.g. out of the photodetector arrays 2 through the dividing lens 3. On the other hand, the light flux passing through the other area 5b is made incident into a photodetector 2a1 of the photodetector arrays 2 through the dividing lens 3 and the phase plate 4. Thus each light flux is divided into two components, which are made incident to corresponding photodetectors 2a1, 2b1 respectively. In order to shift the dividing ratio to any side, the border is shifted in parallel at a position close to the straight line 6. |
