Patent ID: 8423173

Claim:
A load port apparatus, comprising: a cassette table, disposed horizontally on a load port frame, and configured to receive a carrier cassette; a lid member detaching mechanism configured to detach a lid member from the carrier cassette, said lid member detaching mechanism comprising: a lid member suction plate including an unlocking mechanism configured to unlock the lid member from the carrier cassette placed on said cassette table and a suction cup configured to attach to the lid member; and a first elevator mechanism configured to vertically move the lid member suction plate; a mapping mechanism configured to map substrates in the carrier cassette, the mapping mechanism comprising: an arm having a horizontal portion and a vertical portion; an optical mapping sensor, attached to said horizontal portion of said arm and projecting toward the carrier cassette, said optical mapping sensor configured to detect the substrates in the carrier cassette; a pivot mechanism configured to pivotally move said arm around a horizontal pivotal axis provided in parallel to said horizontal portion of said arm whereby the optical mapping sensor is moved to a mapping position in the carrier cassette; and a second elevator mechanism configured to vertically move the arm and the pivot mechanism; and an interference avoiding sensor configured to detect that a vertical distance between said lid member suction plate and said arm exceeds a preset value and to enable the pivotal motion of said arm; wherein said arm is pivotally moved to move the optical mapping sensor to the mapping position to start the mapping of the substrates in the carrier cassette in response to the detection by the interference avoiding sensor.