North American Philips Corporation

Philips Electronics North America Corporation

Andre A Van Der Voort

Robert L Donofrio

The bulls-eye effect produced in the projected image by projection television cathode ray display tubes with convexly curved faceplates and multi-layer interference filters is compensated by using darkened or tinted glass. Since the faceplate glass is thicker in the center, more attenuation of the light output occurs there than at the edges of the display window where the glass is thinner, resulting in improved luminance uniformity of the display.

Monochrome CRT having curved display window with reduced transmission

The bulls-eye effect produced by projection television cathode ray display tubes with convexly curved faceplates and multi-layer interference filters is compensated by increasing the optical absorption of one of the filter layers having a decreasing center-to-edge thickness gradient. Since the layer is thicker in the center, more attenuation of the light output occurs there than at the edges of the display window, resulting in improved luminance uniformity of the display.

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Son en Breugel, Netherlands

Andre A Van Der Voort