| 摘要 |
PURPOSE:To detect the substrate easily and positively in non-contact by a method wherein fixed light projected from a projecting means is transmitted to the substrate, and projecting light attenuated depending upon the transmissivity of the substrate is detected. CONSTITUTION:A plurality of sapphire substrates 1 are housed in a carrier frame, the substrates 1 are singly extracted successively from the carrier frame while being each transferred to fixed manufacturing process locations 1', 1'', 1''', and the substrates are placed on a base plate 6, a vacuum chuck 7, a conveyor base 8, etc. respectively and transported. When the substrate at the location of 1'', a projecting means device 2 for projecting fixed light beams and a light receiving means device are fastened in non-contact and at proper intervals on a light path 9 common in the upper and lower surface direction, avoiding the chuck 7. When there is the substrate, the existence of the substrate can be detected by means of a comparing detecting means because the quantity of light is attenuated depending upon the transmissivity. |
