<p>A discriminating type defect detector detects the size and position of any defect which exists on ribbon-shape glass sheets withdrawn from a kiln and conveyed on a line conveyor. It sends them as defect data to a control unit. The unit sorts the quality of cut glass sheets based on the fault data. A sheet pick-up machine having a push-up device and suction conveyor, picks up prods. of desired grade under control of the unit.</p>
