Patent ID: 8004343

Claim:
A driver circuit, comprising: a first switching element and a second switching element which are connected in series to two ends of an electric voltage source, such that a driven load having a capacity is connected to a connection line connecting the first and second switching elements to each other; and an inverter which inverts, when a control signal having a variable voltage is applied to the first switching element, the control signal into an inverted control signal, so that the inverted control signal is applied to the second switching element, wherein in a state in which the first switching element is turned on by the control signal and the second switching element is turned off by the inverted control signal, a drive voltage is applied from one of the two ends of the electric voltage source to the driven load and, in a state in which the first switching element is turned off by the control signal and the second switching element is turned on by the inverted control signal, an electric charge of the driven load is discharged to an other of the two ends of the electric voltage source, and wherein a first threshold voltage to turn on the first switching element and a second threshold voltage to turn off the second switching element are pre-set such that a first time duration in which the first switching element is turned on and a second time duration in which the second switching element is turned on do not overlap each other, wherein a first threshold value, th TrA , as the first threshold voltage, a second threshold value, th TrB , as the second threshold voltage, and a third threshold value, th INV , as a third threshold voltage to turn on the inverter to start inverting the control signal into the inverted control signal, satisfy following expressions, when a voltage of a variable portion of the control signal and a voltage of a variable portion of the inverted control signal are regarded as increasing and decreasing, respectively, in proportion to time at a common slope: th TrA +th TrB >100 +th INV (1) th TrA >th INV (2) wherein each of the first, second, and third threshold values, th TrA , th TrB , th INV , is a percentage (%) of a highest voltage of the control signal; and 100 is a hundred percent of the highest voltage of the control signal.