摘要 |
Methods and apparatus for solving the problem of non-uniform phosphor aging of the screen of a dual mode television receiver having the capability of displaying the picture image in two different aspect ratios, for example, 4:3 and 5:3. In one embodiment, the entire screen is illuminated during display of a 4:3 aspect ratio image on the central area of the screen so as to effect uniformity of aging over the entire screen. Alternatively, the areas at either side of the central 4:3 aspect ratio image area are not illuminated during display of 4:3 aspect ratio images but are, instead, post-aged following a period of display of such images. Another solution is to electrically compensate for the faster aging of the central 4:3 aspect ratio are of the screen when viewing 5:3 aspect ratio pictures.
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