| 摘要 |
<p>PURPOSE:To obtain the small-sized, inexpensive optical volume control of simple structure by providing a rectangular hole which parts an optical waveguide and inserting and extracting a light shield plate which is operated with a knob into and from the hole, and thus varying the quantity of sent light. CONSTITUTION:An optical wiring plate 4 is provided on the reverse surface of the printed board of an optical sensor and the optical waveguide 14 is formed in its center. The rectangular hole 1 is provided so as to divide the waveguide 14 into sections, and the light shield plate 8 is inserted into and extracted from the rectangular hole through a cam 1 formed on the shaft 12 of an operation knob 3. In this constitution, when the operation knob 3 is rotated, the light shield plate 8 is pressed downward with the cam 1 and a light shield piece 8a is inserted into the rectangular hole 11 to set off the sent light, thereby controlling the quantity of the sent light. The structure is therefore simplified to obtain the small-sized, inexpensive optical volume control which is used effectively for the optical wiring plate.</p> |
