| 摘要 |
PURPOSE:To prevent erroneous detection of the end of a tape due to external disturbing light by forming many recessed and projecting parts, which scatter the light, on the inside face of a cassette case around light transmission holes which are formed on side faces of the cassette case and receive the light from a light source placed in the cassette case. CONSTITUTION:Apertures 12 and 12 as light transmission holes are formed in parts, through which notches 11a and 11a provided on a cylindrical part 11 can be seen, of upper edges of parts 7a' and 7b' slightly recessed inward of right and left side walls 7a and 7b, and many recessed and projecting stripes 13, 13... are formed on inside faces of front parts 7a' and 7b' of side walls 7a and 7b and the upper face of a bottom plate 5 abutting them. Thus, erroneous detection due to external disturbing light is prevented because the light which is made incident on the inside of the cassette case and is reflected on inside faces around light transmission holes of the cassette case is scattered and attenuated by many recessed and projecting stripes formed on inside faces. |
