JPS6434655A - Disc machining method and device therefor - Google Patents

Abstract

PURPOSE:To form a fine groove having small rising and high accuracy on a disc by, after forming a fine groove on the disc using the primary polishing table, machining the fine groove through the secondary polishing table having abrasive grains smaller then those on the primary polishing table at increased relative speed to the disc and under reduced pressing force. CONSTITUTION:Polishing tables 2 are simultaneously pressed onto both surfaces of a disc 1 under the primary pressing force, and reciprocated as they are moved in the peripheral direction of the disc 1 and oscillated in its radial direction, and the disc 1 is simultaneously rotated to attain the primary relative speed, and cleaned after machining the fine groove on the disc. Next, polishing tables 18 being smaller in the diameter of an abrasive grain than the table 2 are pressed on both the surfaces of the disc 1 under the secondary pressing force weaker than the primary pressing force, and the disc 1 is rotated that its relative speed to the table 18 may attain the secondary relative speed higher than the primary relative one, and similarly machined for removing rising formed along an edge of the fine groove, and finally washed. Thus the fine groove having the small rising and high accuracy can be formed on the disc 1.