PURPOSE: To accomplish the detection of deficiency on a glass plate in a rational and efficient manner under the on-line by means of a light source for projecting on the glass plate and a screen provided in the conveying route of a conveyor for transferring the glass plate.
CONSTITUTION: A glass plate delivered from the conveyor on the production line is carried onto to a fixed slant roller conveyor part 1B2. Then, a radial beam is projected from a mercury-arc lamp 2 in the direction inclined toward the upper hand of the carrying surface 1a of the conveyor from below the carrying direction thereof transmitting the glass plate A on the roller conveyor part 1B3 to form a expanded image of the glass plate on a screen 3. The bend spot strain, strain due to the difference in the thickness of intermediate film, overlapping or the like are projected magnified in white on the screen. The foreign matter is projected magnified as a black spot. In this manner, the detection of deficiency on the glass plate can be done in a rational and efficient manner under the on-line.
KODAMA HITOSHI
INOUE HIROSHI
