noun
automatic ticket gate; automatic turnstile
Refers to the automated gates at train stations that read IC cards or tickets.
自動改札機にICカードをタッチしてください。
Please touch your IC card to the automatic ticket gate.
改札口 is the ticket gate area or entrance, while 自動改札機 is the machine itself.
Compound of 自動 (automatic), 改札 (ticket inspection), and 機 (machine).