| 摘要 |
<p>PURPOSE:To prevent intrusion of dust into an outer container and to prevent erroneous detection, by covering a hollow collumn shaped outer container enclosing a light emitting element and a light receiving element with a light transmitting resin layer, and covering a window part, which is formed in said outer container. CONSTITUTION:In a hollow collumn-shaped outer container 2, a light emitting element and a light receiving element are enclosed. A window 5 is provided in the outer container 2 so that light is sent to and received from the light receiving element and the light emitting element. The collumn-shaped outer container 2 is covered with a transparent resin having light transmitting property and thermal expansion and contracting property. The resin is heated to 70 deg.C, and the window 5 is completely covered. As a resin, vinyl chloride, Teflon and nylon can be applied.</p> |
