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This paper presents iron loss reduction in the cores of induction heating (IH) coils for a small-foreign-metal particle (SFMP) detector with a 400-kHz SiC-MOSFETs high-frequency inverter. A new core shape for IH coils, which can reduce iron loss, is designed for the stable and continuous operation of the SFMP detector. Magnetic field analysis results using JSOL JMAG software, a 3D full-wave electromagnetic field simulation software, demonstrate that the iron loss caused by the new core shape for IH coils is decreased by 71.8%, compared with that of the previously proposed IH coils, which increase the magnetic flux density to heat SFMPs by 20%. Thus, the stable and continuous operation of the SFMP detector with the newly designed core shape of IH coils can be achieved. It is also shown that SFMP represented by 0.3-mm diameter stainless-steel balls (SUS304) can be detected on the high-performance chemical film (HPCF) with the newly designed core shape of IH coils using JSOL JMAG software. A prototype experimental setup of the SFMP detector with the new core shape of IH coils is constructed and tested. Experimental results demonstrate that a 400-kHz SiC-MOSFETs high-frequency-inverter-based SFMP detector with the newly designed core shape of IH coils can heat SFMPs, which can be observed by a thermographic camera. Therefore, the authors conclude that the 400-kHz SiC-MOSFETs high-frequency-inverter-based SFMPs detector with the newly designed core shape of IH coils is applicable for HPCF production lines.

This study focuses on differences of luminance of light due to inspection environment, and considers experimentally the effect of luminance of light on defect detection in visual inspection utilizing peripheral vision. In the experiment, the luminance of light, defect locations, and defect characteristics (luminance contrast and size) were designed as experimental factors, and their effect on defect detection rate was evaluated. As a result, it was clarified that the defect detection rate is low in case that the luminance of light is 0lx and the rate increases in case that the luminance is between 1500lx and 6000lx. Moreover, it was found that the tendency also depends on the defect locations and surface luminance of defect (evaluation index of visibility of defects that was proposed in previous study) . From the above, in order to realize highly accurate visual inspection, it is necessary to control appropriately inspection environment according to a field of vision using for inspection (range of inspection by one fixation point) and surface luminance of defect. 本研究では，周辺視野を活用した目視検査において検査環境の違いによる照明の明るさの相違が欠点検出に及ぼす影響について検討するため，照明の照度と欠点の配置，および欠点の特徴(輝度コントラストと大 きさ)を変動要因とする実験を考案し，これらが周辺視野での欠点検出に及ぼす影響について実験的に評価 した．その結果，欠点検出率は照明の照度が0 lx程度だと低くなり，1500～6000 lx間であれば同程度に高く なることが明らかになった．さらに，この傾向は欠点の配置や先行研究で提案されている欠点自体の視認性 を評価する指標である欠点の面光度によっても異なることがわかった．以上のことから，実際の目視検査工 程で精度の高い目視検査を実現するためには，検査で活用する視野(一度の注視で検査する範囲)と欠点の 面光度に合わせて照明の照度が低くならないように適切にコントロールすることの必要性が示された． (キーワード：目視検査，検査環境，照度，周辺視野，欠点検出) 1 受付：2017年12月3日 受理：2018年6月1日 2 成蹊大学 Seikei University 3 青山学院大学 Aoyama Gakuin University ■原 著■ 153 原著：周辺視野を活用した目視検査における照明の明るさが欠点検出に及ぼす影響に関する研究 157 原著：周辺視野を活用した目視検査における照明の明るさが欠点検出に及ぼす影響に関する研究

Abstrarf-A Higkconauctrvity IGBT (HiGT) with a merse biased safe opeatbig area (RBSOA) as large as Umt of a conventional IGBT has been presented. Ihe falricated HiGT has a rated CUTW of 50 A and 8 blocking capability of 3.3 kV, Optimizing the concenhation of i q n u i k is the hole berrfa Inyer embled the E T to tun ofla current twice the rated fllpDnt by applying 2uIo V, which is the mnximum voltage of the 1580-V l h l b i s targe W O A m s mintaimxi while achieving a short cirarit cellaaifity and a betk tmde-ofl relation between the colleetoremhs satuatlon voltage (Vm(sat)) ami the turroff loss. nK Vce(&at) of this op(hnized HCT WBS 1 3 V lower than that of a conventional IGBT. The hrn-off loss, short circuit capability, a d Stptic anddymmicsvalanehe voltages were equivalent to those of conventioml IGBT.