Partly transmittable mirror channel-connecting photo switch having photodetector

Abstract

Abstract PURPOSE:To readily detect the subscribers' first call and clearing call by incorporating photodetectors into the channel-connecting photo switch using partly transmittable mirrors. CONSTITUTION:Unless there is no first call from any subscriber 1, the channel- connecting photo switch 2 does not perform the connection of the X-row and Y- column and therefore mirrors 5 are held lowered by a control circuit 4. When any subscriber 1 taken up a receiver, the light signal of the first call is sent out and is sent to the connecting photo switch 2 by passing an optical fiber 3 and is input to a photodetector 7. Thence, the photodetector 7 converts the light signal of this first call to an electric signal and supplies the same to the control circuit 4. The control circuit 4 when supplied with this information raises the necessary mirror 5 to connect the X-row and Y-column. Since the partly transmittable mirrors are used for the connecting photo switch 2, the detectors 7 are able to receiver the light signals even if the X-row and Y-column are held connected and are able to detect the clearing call from the subscribers 1. In this way, the first call and clearing call may be readily detected.

Inventors

• 👤 Hiroshi Nakamura
• 👤 Naomasa Hanano
• 👤 Tsutomu Fukugahara
• 👤 Kazuo Iguchi
• 👤 Masaaki Takahashi

Bibliographic Details