Substrate detecting system with edge detection, such as wafer or base material of semiconductor device or LCD

Abstract

A plurality of light-emitting/receiving sections respectively include light-emitting sections arranged to correspond to substrates to be detected and light-receiving sections for receiving beams from the light-emitting sections. The substrates to be detected are a predetermined number of substrates arranged and accommodated at predetermined intervals in a substrate accommodating section. A moving section relatively moves the plurality of light-emitting/receiving sections and the substrates to be detected in directions cross or perpendicular to each other. A plurality of signal processing sections respectively detect changes in received light amounts caused in accordance with an output signal from each of light-receiving sections, when beams from the light-emitting sections are opposite to edge portions of the substrates to be detected while the plurality of light-emitting/receiving sections and the substrates to be detected are moved relative to each other in the directions cross or perpendicular to each other by the moving section. A detecting section detects the presence/absence of the predetermined number of substrates to be detected which are arranged and accommodated in the substrate accommodating section in accordance with output signals from the plurality of signal processing sections.

Dependencies are inferred from the claim text.