PURPOSE: To make it possible to adjust speaker volume and liquid crystal display(LCD) contract only by key operation and to reduce the number of parts by providing a telephone set with a control means for changing the resistance value of an electronic volume when the output of a key detecting means is received and the prescribed key operation is executed.
CONSTITUTION: In the case of adjusting the input level of an objective element such as the density of an LCD 12 and the volume of a speaker 9 to be adjusted at its input level, the execution of the prescribed key operation is detected by a key detecting means 7 and the key operation information is outputted to the control means 4a. When the output of the means 7 is the prescribed key operation input, the control means 4a controls the resistance value of the electronic volume 6 so as to change it. Thereby, the volume of the speaker and the contrast of the LCD can be adjusted simply by the key operation and the number of parts can be reduced.
IKEGAMI MASAHITO
HATA KIMITOSHI
| JPS62216559A | 1987-09-24 | |||
| JPS5465275A | 1979-05-25 |