| 摘要 |
PURPOSE:To inhibit an unselected segment from emitting light by discharge by induction between electrodes by connecting a resistor in series with a switch which connects a digit electrode to a low-potential side power source terminal. CONSTITUTION:The resistance part R8 is connected in series with the switch TR4 which connects the digit electrode 22 to the low-potential side power source terminal. The digital electrode 22 and a segment electrode 12 which face each other form a capacity load, so when the potential of the digit electrode 22 is to be lowered, the digit electrode 22 falls in voltage according to the time constant determined by the product of the capacity value and the resistance value of a resistor R6. Therefore, a spike-shaped voltage induced at the segment electrode 12 drops. The voltage waveform between both electrodes is a waveform formed by adding the spike-shaped voltage to the inverted part of its slow falling part. Consequently, an overshoot becomes zero or decreases and a segment which is not selected never emits light by discharging. |
