| 摘要 |
<p>PURPOSE:To simplify a composition at low cost with less part numbers by equipping an optical reflection member at opposing position of the outer side pinching a tape and the light emitting and receiving elements of which the light emitting part emittable in one direction via a light shielding member and the light receiving part detectable from the direction are set up. CONSTITUTION:The package element 1 consisting of a light receiving element 5 and a light emitting element 4 and becoming in one package so that the light emitted from the light emitting element 4 may not be leaked directly into the light receiving element 5 by a light shielding plate 6 is arranged in two pieces toward the opposing directions. A mirror 2 is set up in two pieces at the linearly symmetric position with the package element 1 as the center a pulse signal is fed by a common pulse signal generator 8 onto each light emitting element 4 and each light receiving element 5 feeds an AC signal to a common DC component removing circuit 9. The passage of these pulse signal and AC signal is made to change according to the running direction, namely according to the positive direction or reverse direction of a tape 7 on two package elements 1. In such a way the power consumption can be reduced.</p> |
