Patent ID: 6932065

Claim:
An internal combustion engine ignition apparatus, comprising: an ignition coil having a primary coil and a secondary coil; and a switching circuit which interrupts a current of the primary coil of the ignition coil on the basis of an ignition signal voltage to generate a high voltage for ignition in the secondary coil of the ignition coil, wherein the ignition signal voltage is a pulse-like voltage including a rising portion and a falling portion, the switching circuit has no power supply terminal connected to a battery and includes an output terminal connected to the primary coil of the ignition coil, an input terminal for receiving the ignition signal voltage, and a reference potential terminal, the switching circuit includes a switching element which is connected between the output terminal and the reference potential terminal, applies a current to the primary coil of the ignition coil in an on state, and interrupts the current of the primary coil when an off state is caused, a drive resistor for the switching element, and a current supply circuit which is connected between the input terminal and the reference potential terminal and supplies a driving current to the drive resistor, on the basis of the ignition signal voltage, the current supply circuit starts to supply the driving current at the rising portion and brings the switching element into the on state, and the current supply circuit interrupts the driving current at the falling portion thereof to bring the switching element into the off state, the current supply circuit includes a constant current circuit, and the constant current circuit causes the driving current to become a constant current, and supplies the driving current, which is made the constant current, to the drive resistor.