| 摘要 |
<p>PROBLEM TO BE SOLVED: To enable accurate surface detection with a simple and compact structure by providing a light emitting diode and a phototransistor on both sides of opening of light radiation made by a prism necessary to be positioned just close to a surface, and arranging a plate member in the route of radiation. SOLUTION: A light emitting diode (LED) 3 and a phototransistor 2 are arranged on both sides of opening of light radiation made by a prism 6 at a terminal end of optical fiber arranged just close to the surface of skin 30, and the opening is set higher than LED 3 and the phototransistor 2. In the route of radiation by LED 3 and radiation reflected against the surface 30, a plate member 8 is disposed over the upper surface of the prism 6, and a distance between the lower surface 32 of the member 8 and LED 3 and phototransistor 2 can be kept. The member 8 gives a route which allows part of radiation to pass therethrough and transmits it to the surface 30, and allows the phototransistor 2 to receive light. The distance between the upper surface 34 of the member 8 and the surface of skin 30 can be detected.</p> |
