| 摘要 |
PURPOSE:To evenly set a resistance in the vicinity of an objective value, by mounting a pulse generation circuit and a resistance meter and again performing the measurement of a resistance value when the measured value by the resistance meter, after a voltage pulse was applied to a heat generating resistor, enters a definite range with respect to the resistance value prior to applying said pulse. CONSTITUTION:The set signal of a peak value Vs and the number (n) of pulse is applied from a calculation part 12. A pulse generation circuit 10 applies the peak value Vs and (n) pulses to the heat generating resistor of a thermal head 7 through a switch 9 and a relaynetwork 8. Thereafter, the switch 9 is changed over to a resistance meter 11 to measure a resistance value ad this measured value is sent to the calculation part 12. CPU14 compares the measured value with the preceding measured value and, when said value does not enter a definite range on the basis of the preceding measured value, contact inferiority is judged. when said value is higher than the preceding one, CPU14 does not employ this measured value and outputs a probe signal, for releasing the contact of a probe needle and performing the re-contact thereof, to a probing apparatus 6. Then, measurement is again performed to obtain a value lower than the preceding one and the resistance value is evenly set in the vicinity of an objective value. |
