| 摘要 |
PROBLEM TO BE SOLVED: To prevent defect in focus detecting operation caused by stray light by perfectly intercepting the strain light advancing from the undesirable aperture of a field mask to the undesirable aperture of a diaphragm mask and reaching a CCD photodetector. SOLUTION: The stray light is perfectly intercepted by a 1st intermediate mask 25 being a separate member from a holder 21, and a 2nd intermediate mask 27 where a 1st mask surface 27h nearly perpendicular to luminous flux which has not been reflected yet by a light reflection member 26 and a 2nd mask surface 27i nearly perpendicular to the luminous flux which has been reflected are integrally formed, whereby the defect in the focus detecting operation caused by the stray light is eliminated, and also cost is reduced by integrating the 2nd intermediate mask 27. |
