| 摘要 |
PROBLEM TO BE SOLVED: To provide the driving system of an LED in a functional telephone that can be shared by models. SOLUTION: Telephone apparatus such as a button telephone apparatus has a telephone control and display sections. The display section includes (n) gate IC circuits where each has m input and output terminals, plural control switch means where each control input side is connected to a desired output terminal out of the m output terminals at each output side of the (n) gate IC circuits, and plural light emitting diodes that are provided between each output side of the plural control switch means and a power supply. In the telephone control section, one of the (n) gate IC circuits is activated according to selection information to be inputted, at the same time, one of the plural control switch means arranged at the output side of the activated gate IC circuit is operated, and the light emitting diode connected to the activated control switch means is driven. |
