| 摘要 |
PROBLEM TO BE SOLVED: To provide an automatic focusing system which can precisely be put in focus by automatic focusing (AF) so that the quantities of subject light incident on respective imaging planes are equivalent. SOLUTION: In a lens system which employs optical path length difference type AF, a light splitting optical system 20 which splits the subject light to imaging elements 22A and 22B for AF is arranged in the optical path for AF of a photographic lens 10, and a 1/4-wavelength plate 28 is arranged in front of it. Consequently, the subject light polarized by the 1/4-wavelength plate is converted into unpolarized light, which is made incident on the light splitting optical system. COPYRIGHT: (C)2006,JPO&NCIPI |
