To solve the problem that the end surface of a glass substrate for a display is warped or twisted because the glass substrate is heat-treated or a membrane of which the coefficient of expansion is different from that of a metal membrane is formed on the substrate heretofore and accurate inspection can not be performed.
This inspection device having the function of flattening the glass substrate is equipped with a distance detecting sensor 26 for detecting the warp state of the glass substrate 7, a nozzle 22 for discharging the air from a compressor 27 and a control part 29 for opening and closing a valve 28 so as to discharge air from the nozzle 22 when the warpage of the glass substrate 7 is detected by the distance detecting sensor 26. The upward warped state (warp quantity) caused in the glass substrate 7 is grasped on the basis of a change in the distance data detected by the distance detecting sensor 26 and air is discharged from the nozzle 22 immediately before the leading end part of the warped glass substrate 7 reaches an imaging position to press the warpage of the glass substrate 7 to a substrate stage 9 by air pressure to flatten the glass substrate 7.
Satoshi Kono
Sadao Muramatsu
Tetsuya Kazama