| 摘要 |
PURPOSE:To obtain a focus detecting device which can be adjusted easily, by providing a holder which can move a photodetector and a focus prism as one body in the direction Z. CONSTITUTION:A titled device is constituted so that a focus prism 12 and a photodetector 13 can be moved as one body in the direction Z through a prism holder 14. At that time, the photodetector 13 can be adjusted with a high accuracy by simple adjustment, by constituting it so that it can be moved in the direction X and the direction theta on the prism holder 14. That is to say, in the initial adjustment, a beam is adjusted in the direction X as shown in a figure (a), and subsequently, adjusted so that photodetecting elements 13b, 13e of a photodetector come to the beam center. Next, as for the adjustment of the direction Z, it can be brought easily into a state of (c), since the photode tector and the prism holder 14 are moved in one body. |
