| 摘要 |
PURPOSE:To unnecessitate fitting space and fitting member, and to execute detection with high accuracy by deviating the position relation of an image forming lens and an image sensor of a sight line detecting system from optical conjugation and allowing defocus. CONSTITUTION:By deviating the position relation of an image forming lens 104 and an image sensor 106 from an image forming point, that is, by allowing the defocus, a satisfactory sight line detecting optical system is attained. Also, it is desirable that its defocus amount Def is allowed to satisfy FX3 p>=Def>=FX0.8p, when F and (p) denote an F-number of the image forming lens and the photoelectric element pitch of the image sensor, respectively. In such a way, by defocusing the position relation, there is an effect corresponding to the case when an optical low-pass filter is arranged in front of the image sensor 106. In this regard, the eye point of a finder means is determined at the time of optical design. |
