| 摘要 |
<p>PURPOSE:To suppress the diffusion of light to a low level by immediately emitting the light emitted from a light emitting part to a table. CONSTITUTION:Light transmission holes 10, 11 are opened at a position neighboring to the tape of a cassette half 1 in which the take-up reel 2 and the supply reel 8 of a magnetic tape 7 are housed, and a take-up side light emitting part 3 and a supply side light emitting part 9 which emit the light, respectively are provided outside the neighboring part of them. Emitted light is received with a take-up side light receiving part 5 and a supply side light receiving part 6 located in the cassette half 1 on almost the extension of the light emitting parts 3, 9 and the light transmission holes 10, 11, thereby, the presence/absence of the magnetic tape 7 can be detected.</p> |
