DETECTOR FOR IN-TALKING CALL UNIT CHANGE TIME

摘要

PURPOSE: To provide the in-talking call unit change time detector of configuration able to detect an in-talking call unit change time without being fixedly connected to a telephone set. ;CONSTITUTION: Photodetectors 21a-21n are provided in the arrangement corresponding to that of display elements of display sections 11, 12, 13 of a telephone set 10 on a face of a mount side of the in-talking call unit quantity change time detector 20. Residual call units of a telephone card displayed on seven- segment display devices 12, 13 are read through the photodetectors 12a-12n by only mounting the detector onto the telephone set 10 without being fixedly connected to the telephone set. As a result, the in-talking call unit quantity change time is detected.;COPYRIGHT: (C)1993,JPO&Japio