| 摘要 |
<p>PURPOSE: To prevent the operation failure by a mechanical wear by reflecting the light emitted from the light emitting part of a light reflecting sensor with a light reflecting piece, and sensing the reflected light by the light receiving part of the light reflecting sensor. CONSTITUTION: In this non-contact rotary mode switch device for magnetic tape recording device, at least one or more reflecting pieces 8 are formed on at least one or more tracks arranged concentrically on the back surface of a mode switch gear 1, respectively, and at least one or more light reflecting sensors 9 having a light emitting part 9' and a light receiving part 9" are provided on a mode switch body 3 on the lower side with a prescribed space from the light reflecting pieces 8. The light emitted from the light emitting part 9' of the light reflecting sensor 9 is reflected by the reflecting piece 8, and sensed by the light receiving part 9" of the light reflecting sensor 9. Since this switch device is a non-contact type mode switch device from which disadvantages of a conventional contact type mode switch are eliminated, an operation failure by mechanical wear, discharge or mechanical deformation as before can be prevented.</p> |
