| 摘要 |
<p>PURPOSE:To prevent the beginning/end of a tape from being erroneously detected by affording a rugged part to the inner surface of a hollow of a projecting part of a protective holder covering a light receiving element. CONSTITUTION:The light receiving element 14 is provided at the inner end of the hollow 13 of the projecting part 12 of the protective holder 11 molded of resin, and the inner surface of the hollow 13 is formed with a satin-like rugged surface by etching a metal mold. When the element 14 is fitted to the protective holder 11 of the above constitution, and a light emitting element is provided opposite to this element 14 so as to detect the beginning/end of the tape, external light 16 which is incident upon the hollow 13 without transmitting the tape is irregularly reflected by the rugged surface 15 of the inner surface of the hollow 13, and hence the quantity of the external light to reach the element 14 is extremely diminished. As a result, the beginning/end of the tape can be prevented from being erroneously detected due to the external light 16.</p> |
