| 摘要 |
<p>The operating panel device comprises an indicator panel having a number of indication marks on it. A number of lightemitting elements emit light signals which pass along a surface o the indicator panel across the indication marks. Light signals from the elements are received, when at least one of the light signals emitted from the first light-emitting elements passing across a specific one of the indication marks on the indicator panel is selectively interrupted. The light-receiving elements detects such a selective interruption of the at least one light signal and sends out to an appropriate control system an operation command signal corresponding to the specific indication mark.</p> |
