| 摘要 |
PROBLEM TO BE SOLVED: To provide a liquid detecting device which can conduct accurate liquid detection by reducing the influence of reflected light by the outer wall or the like, while ensuring a detection area considering the influence of air bubbles and droplets attaching on the inside of a liquid containing vessel. SOLUTION: A light receiving lens 23 is deposited such that its lens central axis L1 approximately coincides with the central axis of light flux of inner-wall- reflected light M1. The inner-wall-reflected light M1 is therefore focused on the focal point accompanied by little influence of outward coma aberration. On the light receiving lens 23, the irradiation point of the center of the light flux of outer-wall-reflected light M2 is positioned farther apart from the lens central axis L1 than that of the inner-wall-reflected light M1. The outer-wall- reflected light M2 therefore forms a comet-like image on a position apart from the focal point under the influence of outward coma aberration. |
