Over the last 55 years, direct-view televisions have evolved from small black-and-white models to large, color models. Screen area has increased thirty-fold, requiring thicker glass to support the high vacuum load in the picture tube. The largest tubes now require more than 140 1bs. (65 kg) of glass, and are more than 1" (2.5 cm) thick in the screen area. These newer, larger televisions must support high-resolution digital signals, with much tighter requirements for screen inside contour and image quality. Manufacturing these large, thick, high-quality screens on old production lines is very challenging. This paper describes some of the ways that thermal imaging is used to meet these challenges. Some uses are simple, such as predictive maintenance inspections common in many factories. Other uses are more complex, such as evaluating metal wear in press equipment and providing data to validate complex models of glass forming. This paper also explores some of the special requirements placed on thermal imaging equipment in a television glass plant. Among other things, these include high operating and ambient temperatures (> 1000 deg C) and the ability to measure temperatures in both highly reflective and semi-transparent materials.
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