United States Patent 10,121,120 (2018登録、Information processing system and recording device：エネルギー会計の基本特許: 日本の登録特許6251166に対応 http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=18&f=G&l=50&co1=AND&d=PTXT&s1=deguchi&s2=hiroshi&OS=deguchi+AND+hiroshi&RS=deguchi+AND+hiroshi )