| 摘要 |
The purpose of the present invention is to reduce the size of an imaging lens unit (1D). A portion of a pencil of light rays expressing an object optical image is deflected vertically downwards by a polarization prism (6), and also deflected forwards by a total reflection mirror (40). A pencil of light rays totally reflected by the total reflection mirror (40) is split into three directions by a tri-directional splitting prism (91). The resultant pencils of light rays are respectively incident on a first optical-path-length-difference imaging element (21), a second optical-path-length-difference imaging element (22), and a phase difference imaging element (33) included in a phase-difference imaging optical system (30). Auto focus (AF) is performed on the basis of the optical path length difference from signals obtained from the optical-path-length-difference imaging elements (21, 22). Furthermore, AF is performed on the basis of the phase difference from a signal obtained from the phase-difference imaging element (33). The phase-difference imaging optical system (30) is disposed so as to be parallel with the axis (O1) of the light forming the object optical image. Accordingly, a reduction in the size of the imaging lens unit (1D) can be achieved. |
