参考文献

Iwasawa, Yoshikuzu; Kato, Tetsuya; Kawanishi, Nobuhiko; Masutani, Kouta; Mita, Takashi; Nonoshita, Katsumasa; Ohkubo, Mitsuru Patent: US2008/58347 A1, 2008 ; Location in patent: Page/Page column 63 ; US 20080058347 A1