Method and apparatus for separating a pane of brittle material from a moving ribbon of the material

Abstract

A pane is separated from a moving ribbon of brittle material by restraining the ribbon upstream of a score line prior to separating the pane. The ribbon is restrained by selectively contacting a first side and a second side of the ribbon in one of an opposite, overlapping or offset relation. The ribbon can be restrained prior to, substantially simultaneous with or subsequent to forming the score line. The restrained status of the ribbon is maintained during and immediately after separation of the pane from the ribbon, thereby reducing the introduction of a disturbance or bending moment into the upstream ribbon.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to separating a pane of a brittle material from a moving ribbon of the material, and in one configuration, to separating panes of glass from a moving ribbon of glass, while reducing the introduction of disturbances into the upstream ribbon. [0003] 2. Description of Related Art [0004] Specialized glasses have found increased applicability, including substrates, in the manufacture of display devices. For example, liquid crystal displays (LCDs) have become increasingly popular for displaying information in calculators, watches, video games, audio and video equipment, portable computers and even car dashboards. The improving quality and size of LCDs has made the LCDs an attractive alternative to cathode ray tubes (CRTs) which are traditionally used in television sets and desktop computer displays. In addition, other flat panel display (FPD) types, such as plasma displays (PDs), field emissi...

AI Technical Summary

Benefits of technology

[0011] The present system provides for the repeatable and uniform separation of a pane of brittle material from a continuously moving ribbon of the brittle material, while reducing the introduction of disturbances into the upstream ribbon.

[0013] In the fusion glass formation process, a glass ribbon transitions from a liquid state to a downstream solid state. The introduction of disturbances into the glass in the visco-elastic region of the glass can result in undesired nonuniformity or stresses in the resulting solid state glass. Traditionally, the separation of a pane from the ribbon introduced significant energy in the form of a vibration, wave or distortion to the solid portion of the ribbon. Such distortion migrates upstream into the visco-elastic region of the ribbon. The distortion can introduce nonuniformity and nonlinearity in an uncontrolled manner, and can decrease the quality of the resulting panes.

[0014] In the present system, the ribbon is restrained upstream of a score line prior to separating the pane from the ribbon. The restraint of the ribbon can be accomplished by contacts upstream of the score line on the first side and the second side of the ribbon, wherein the contacts are either opposite, overlapping or offset. The restraint can be prior to, substantially simultaneous with or subsequent to forming the score line in the ribbon. The restraint of the ribbon is selected to facilitate separation of a pane from the ribbon and minimize or reduce the introduction of a disturbance or bending moment into the upstream ribbon.

[0015] The present system separates the pane from the ribbon and reduces the propagation of disturbances upstream in the ribbon by contacting opposing sides of the ribbon with a pair of opposing bars, wherein the bars move with the ribbon, thereby restraining a portion of the ribbon upstream of a score line. A downstream press bar contacts the ribbon downstream of a score line to separate the pane from the ribbon along the score line, while the ribbon is temporarily restrained upstream of the separation line.

Problems solved by technology

The introduction of disturbances into the glass in the visco-elastic region of the glass can result in undesired nonuniformity or stresses in the resulting solid state glass.

The distortion can introduce nonuniformity and nonlinearity in an uncontrolled manner, and can decrease the quality of the resulting panes.

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