Patent ID: 6870401

Claim:
A signal transmission circuit comprising plural stages of circuit from each of which a pulse voltage according to a driving pulse is sequentially outputted, the circuit of each stage including: an output transistor which outputs the pulse voltage to a source of the output transistor, according to the driving pulse; a bootstrap capacitor connected between a gate of the output transistor and the source; a first charging transistor whose drain is connected to a power source or an earth line and whose source is connected to the gate of the output transistor in order to charge the bootstrap capacitor, wherein in the case where a first discharging transistor is in the first stage, a start pulse is provided to the gate of the first discharging transistor, and in the case where the first discharging transistor is in the second stage or backward, the gate of the first discharging transistor is connected to the gate of the output transistor of the forward stage; a first discharging transistor whose drain is connected to one end of the bootstrap capacitor; a second discharging transistor whose drain is connected to the other end of the bootstrap capacitor; and an output transistor control circuit which prevents the pulse voltage from being outputted from the output transistor of each circuit of the other stages, in the case the pulse voltage is outputted from the source of the output transistor.