Tempered glass sheet having a central zone of higher compressive stress, process and apparatus therefor

摘要

A tempered glass sheet having in its front view a peripheral region including the peripheries, and a central region (9) occupying inside the peripheral region, wherein the average surface compressive stress in the central region (9) is larger than the average surface compressive stress in the peripheral region, is presented, whereby a tempered glass sheet having a thickness thinner than conventional ones can be provided. Apparatus and method for producing such tempered glass sheet are also disclosed.