GAS JETTING DEVICE FOR CORRECTING WHITE DEFECT OF MASK

摘要

PURPOSE:To improve response and reproducibility by shortening the distance between an exit port in the front end of a nozzle and a valve body and controlling digitally the flow rate of glass by the valve body. CONSTITUTION:Plural apertures 20 are provided along the outside peripheral surface of a valve body 13 and are different in diameter, and a motor 24 is attached to the other end of the valve body 13 to rotate the valve body 13. If the valve body 13 is rotated to allow one of plural apertures 20 to face a connection tube 19, gas stored in a gas reservoir 14 of the valve body 13 is led to an empty chamber 17 of the nozzle through the communicating tube 19 facing said aperture and is jetted from an exit port 12. Since the route from the gas reservoir 14 to the exit port 12 is very short, the response of gas jetting is very good. Diameters of apertures 20 are selected properly to adjust digitally the quantity of jet. Thus, the reproducibility is improved.