| 摘要 |
PURPOSE:To improve response velocity of detection by solving the problem of stagnant liquid by vertically disposing a light emission part and a light- receiving part, forming a lens part as a spheroid having focal points of the light emission part and the light receiving part, and providing a conical part whose vertex is made downward in the lower side of a base part. CONSTITUTION:A light emission part 3 and a light-receiving part 4 are disposed on a lead frame 2 so that a line passing them may be vertical. The shape of a lens part 5a is formed as a spheroid having focal points of the light emission part 3 and the light-receiving part 4, and it is obtained when a rotation is made with a line passing them as a major axis Z. Accordingly, the lens part 5a is made projected from a base part 5b. A conical part 5c is provided on the lower side of the base part 5b, whose apex is made downward and which has a central axis in the vertical direction. The conical part 5c has a form which does not have a step nor a corner so that stagnant liquid may not be produced in this part. When the lens part 5a is exposed in the air from liquid, a detection delay due to production of stagnant liquid in the lower end part can be surely avoided in almost all cases. |
