| 摘要 |
A detecting unit for automatic tune selection apparatus of a phonographic record player comprising a light projector and a CdS photoelectric element housed in a casing, said casing having a cylindrical light shield barrel extending axially downwardly therefrom having a constricted aperture formed thereon at the lower end portion thereof so as to form a limited passage for exclusive reception of the reflection of light rays from its own light source, warding off all the reflections of the light source from outside, thereby ensuring accurate actuation of said detecting unit for the automatic tune selection system without any incidental failure.
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