Patent ID: 7928771

Claim:
A driving signal output circuit comprising: a signal input terminal to which two input signals are input; a logic circuit to which the two input signals from the signal input terminal are input and which outputs a plurality of control signals corresponding to four states created by high level and low level of the two input signals; an output circuit which includes a plurality of transistors which are controlled by the plurality of control signals, and which outputs a drive signal for driving a load, the drive signal corresponding to states of the plurality of transistors; and a logic setting terminal to which a setting signal is input, wherein the setting signal assumes either high level or low level, wherein the plurality of control signals have: a first mode for controlling the plurality of transistors of the output circuit to generate four states in accordance with the four states of the input signals, wherein the generated four states include a state in which a current is supplied to the load in a forward direction, a state in which a current is supplied to the load in a backward direction, a state in which the terminals of the load are isolated, and a state in which the terminals of the load are short-circuited; and a second mode for controlling the plurality of transistors of the output circuit to generate three states in accordance with the four states of the input signals, wherein the generated three states include a state in which a current is supplied to the load in a forward direction, a state in which a current is supplied to the load in a backward direction, and a state in which the terminals of the load are isolated, and in the logic circuit, whether to generate the plurality of control signals of the first mode or to generate the plurality of control signals of the second mode is switched according to high level or low level of the one setting signal which is input to the logic setting terminal.