CIRCUIT AND METHOD FOR DETECTING INK CARTRIDGE OF INK-JET RECORDER

PROBLEM TO BE SOLVED: To detect whether an ink cartridge is mounted even if a special detection mechanism is not provided to the ink cartridge. SOLUTION: The voltage detection circuit 102 provided on the side of the drive power supply Vpp of heating elements RT1-n to detect voltage changed by the driving the heating elements is provided and the detected voltage by the circuit 102 at a time of the driving of the heating elements is compared with reference voltage. The reference viltage is set to the voltage between the detected voltage at a time when all of transistors Q1-Qn are turned OFF and the detected voltage at a time when one of the transistors Q1-Qn is turned ON. When a cartridge is not mounted, even if all of the transistors Q1-Qn are turned ON, the detected voltage becomes larger than reference voltage because of a heating element free state. Contrarily, when the cartridge is mounted and all of the transistors Q1-Qn are turned ON, the detected voltage becomes smaller than the refernece voltage because the heating elements are connected in parallel.