METHODS FOR FORMING GLASS ELLIPTICAL AND SPHERICAL SHELL MIRROR BLANKS

摘要

A method of producing glass focusing mirror blanks comprises providing a glass sheet, heating the glass sheet sufficiently to allow permanent deformation and reforming the glass sheet into an array of glass shell structures by either (1) pressing the sheet or (2) vacuum or differential-pressure forming the sheet. Either (1) the step of pressing is performed using a positive mold surface comprising an array of protrusions pressed in contact with respective resulting inner concave surfaces and without contacting resulting respective outer convex surfaces of the shells or (2) the step of vacuum or differential-pressure forming is performed using a mold surface comprising an array of through holes with the shell structures formed by vacuum or differential pressure forming of the sheet against the mold surface without contacting the resulting respective outer convex surfaces or the resulting respective inner concave surfaces.