Patent ID: 6830781
Filing Date: 2004-12-14
Classification: C03B

Abstract:
A method for producing an SiO2 blank, said method comprising:forming SiO2 particles in a burner flame associated with a deposition burner, said burner flame having a shape; and depositing said particles under the effect of an electrical field on a deposition surface of a carrier rotating about a longitudinal axis thereof; said deposition burner being supported for relative longitudinal reciprocation with respect to the developing blank between turn-around points thereon; and said electrical field varying the shape of said burner flame during the reciprocation thereof dependent upon relative location of said deposition burner relative to the blank; wherein a plurality of deposition burners are used that each have a burner flame with a shape and are spaced apart from one another longitudinally, and that are reciprocated in a predetermined sequence of movement in synchronism along the developing blank between turn-around points, the shape of the respective burner flames being changed in synchronism by said electrical field dependent upon location of said deposition burners during the sequence of movement; and wherein a plurality of electrical fields are associated with said burner flames and are varied in synchronism in a change cycle correlated with the sequence of movement of said deposition burners.