JPH02140559U - - Google Patents

Description

[Brief explanation of drawings]

FIG. 1 is a current flow control circuit diagram according to an embodiment of the present invention, FIG. 2 is a current waveform diagram when the power is turned on in the current flow control circuit shown in FIG. 1, and FIG. 3 is a current waveform diagram in the current waveform shown in FIG. A current waveform diagram connecting peaks to peaks, Figure 4 is a diagram of the change in resistance value due to temperature of the halogen lamp filament and thermistor,
FIG. 5 is a schematic cross-sectional view of a conventional heat fixing device, FIG. 6 is a circuit diagram for energization control of a heating source in a conventional heat fixing device, and FIG. 7 is a diagram of a change in resistance value depending on temperature of a filament of a halogen lamp. FIG. 8 is a current waveform diagram when power is turned on in the energization control circuit of FIG. 5, and FIG. 9 is a current waveform diagram connecting the peaks of the current in the current waveform of FIG. 7. 2...Halogen lamp (heating source), 10...Thermistor (temperature-sensitive resistance element).

Claims (1)

[Scope of Claim for Utility Model Registration] In an energization control circuit for a heating source in a heat fixing device of an electrophotographic printer, which has a positive temperature coefficient characteristic in which resistance increases as the temperature rises due to heat generation, in series with the heating source. Inrush current is reduced by connecting one or more temperature-sensitive resistance elements having negative temperature coefficient characteristics and canceling out the positive temperature coefficient characteristics of the heating source and the negative temperature coefficient characteristics of the temperature-sensitive resistance element. A power supply control circuit for a heating source in a heat fixing device of an electrophotographic printer, characterized in that: