We adopt a belt fusing method as a fixing system of our electro photographic full color printer. The lifetime of the fusing unit used in this method ends with the cracking of the belt, which uses very thin nickel electroforming as the base material. In order to extend the lifetime, we have developed materials with excellent resistance to belt cracking. This paper presents the results of our new experiment, in which we modified the system design parameter and the standards by using the advice in previously presented results. We evaluated various metals using V-I characteristic evaluation, which was one of the evaluation methods that we have already suggested. As a result, we were able to significantly reduce the time required for evaluation. In addition, we defined the new electrical characteristics with reference to the concept of the standardized S/N ratio, resulting in the successful establishment of an evaluation method more versatile than the previous one.

ソーシャルメディア上のテキストデータを対象とした分析には,多くの

Immunity testing of electronic equipment for electrostatic discharge (ESD) is prescribed as IEC 61000-4-2 by the International Electrotechnical Committee (IEC), in which contact discharge current testing from an ESD generator is specified with only the following four parameters: the rise time of the first peak current, the current value of the first peak, the current values at 30 ns and at 60 ns. To reduce the variations in test results by different ESD generators, the Japanese national committee of IEC SC77B once proposed a time width of 60% of the first peak current as an additional specified parameter in the IEC standard, while the proposal was not adopted since a round robin test was unable to confirm the effectiveness. In the 2008 revised version, a theoretical calibration current waveform based on the Heidler’s formula was shown as the typical contact discharge current waveform from an ESD generator. In this paper, using different eight models of commercially available ESD generators manufactured by six manufacturers from the market, we compare the waveforms of discharge currents measured for contact discharges with the calculated waveform from the Heidler's formula. In addition to the IEC specified parameters, the previously proposed time width (1.5 ns to 3.5 ns) of 60% of the first peak current is also examined. Results show that almost all the ESD generators except for one generator meet the specifications, and that there are only four generators whose time widths of 60% of the first peak currents satisfy the suggested time width. Furthermore, all the frequency current spectra at frequencies lower than 30 MHz approximately agree with the current spectrum calculated from the Heidler’s formula, whereas they vary depending on the ESD generators at frequencies higher than 30 MHz, even though ESD generators meet both the IEC specified requirements and the assumed time width of 60% of the first peak.

The International Electrotechnical Commission (IEC) 61000-4-2 specifies an air discharge testing method as a mandatory electrostatic discharge (ESD) immunity test, since an actual charged human accompanies air discharges. In addition, the IEC standard also prescribes the holding time of over 5 s where the decrease of the discharge electrode voltage due to current leakage, prior to the air discharge, should not be greater than 10%, whereas no measurement method has been specified. In this study, a method is proposed for measuring the holding output voltage of an ESD generator in air discharge mode with a commercially available high voltage probe connected through a wire to a small metal sphere for contact discharges and air discharges. The proposed method consists of two steps that measure the peak voltages for contact discharge with a test voltage and for air discharge with the same test voltage but in 5 seconds after the trigger. The ratio of the latter peak voltage to the former one provides the ratio of the holding output voltage to the test voltage. The measurement principle is shown theoretically using the equivalent circuits for a measurement setup, and is validated numerically and experimentally. To demonstrate the effectiveness of the presented method, measurements of the holding output voltages for two defective ESD generators collected from the market are conducted in comparison with a normal ESD generator.