| 摘要 |
PROBLEM TO BE SOLVED: To use a liquid level sensor having a light emitting part and a light receiving part integrated into one body, to detect whether a liquid level of a liquid stored in a concave portion of a workpiece has reached a target height or not while supplying the liquid into the concave portion of the workpiece from a delivery port at a front end of a needle.SOLUTION: When a liquid level LS of a liquid stored in a concave portion W2 of a workpiece W reaches a target height TH during liquid supply from a needle 103 of a liquid supply device 100 into the concave portion W2, light emitted from a light emitting part S1a of a liquid level sensor S1 in a position farther from a center axial line 103CL of the needle 103 than an irradiation position IP1 reaches the irradiation position IP1 set to an outer part LS2b where the liquid level LS is lower at a longer distance from the center axial line 103CL, of a ring-shaped rising part LS2 of the liquid level LS and is reflected, and reflected light from the irradiation position IP1 travels farther away from the center axial line 103CL and is detected by a light receiving part S1b of the liquid level sensor S1 in a position farther from the center axial line 103CL than the irradiation position IP1. |
