| 摘要 |
PURPOSE: A dot error inspecting apparatus for a thermal print head is provided to precisely determine a dot error by varying reference voltage of a comparator according to the number of dots. CONSTITUTION: A thermal print head(4) is provided with a plurality of switches(20a,20b,20c,20n), which is turned on/off depending on printing data outputted from a shift register(4a). First ends of the switches(20a,20b,20c,20n) are commonly connected to driving voltage. Second ends of the switches(20a,20b,20c,20n) are commonly connected to a resistor(22). An amplifier(24) is provided to amplify voltage applied to the resistor(22). A comparator(26) is provided to determine a dot error by comparing voltage outputted from the amplifier(24) with reference voltage. A count circuit(28) counts a number of dots to be printed according to printing data inputted into the shift register(4a).
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