Patent ID: 8497890

Claim:
A thermal print head detecting device, comprising a power supply, a power supply switch, a power supply switch control circuit, a first detecting resistor, a second detecting resistor, a print head to be detected and a print head control circuit; wherein an output end of the power supply is connected to a common joint of respective heating element units of the print head through the power supply switch, the first detecting resistor is connected in parallel with the power supply switch; an output end of the power supply switch control circuit is connected to a control end of the power supply switch; one end of the second detecting resistor is connected to the common joint of the heating element units and the other end of the second detecting resistor is grounded; and the print head control circuit controls strobing of respective heating element units of the print head, wherein a resistance value of the second detecting resistor is bigger than a resistance value of the heating element unit of the print head.