| 摘要 |
A television receiver includes a light emitting diode channel number display. The supply voltage for the display is developed by an amplifier in response to a control voltage generated by a control circuit including a light sensing element for controlling the contrast and color level properties of the picture produced by the receiver as a direct function of the ambient light in the receiver's environment. The amplifier is arranged so that the supply voltage for the LED channel number display, and therefore its illumination, is a direct function of the ambient light and tracks the contrast and color level properties of the picture. In addition, the gain of the amplifier is selected so that the photometric brightness of the LED channel number display as perceived by a viewer is attenuated with respect to the photometric brightness of the picture as perceived by a viewer.
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