| 摘要 |
PURPOSE:To always keep the contrast of a television picture at the optimum level, by providing a panel whose transmission factor for light is variable, at the front plane of a television screen, and changing the transmission by a controller corresponding to the intensity of extraneous light. CONSTITUTION:At the front plane of a television screen 1, a dimmer panel 5 whose transmission factor is variable, and an operating part 6 which changes the transmission factor of the dimmer panel 5, are provided. The contrast of the television picture is represented by the difference of attenuation between light 3 of the television picture by the dimmer panel 5, and extraneous light 4. As a result, by making small the transmission factor the dimmer panel 5 by the operating part 6 when the extraneous light 4 is intensive, and making large the transmission factor of the dimmer panel 5 when the extraneous light 4 is weak, the contrast of the television picture cab be maintained at the optimum state. Also, when the above is performed by an automatic operation, an optical sensor 7 detects the intensity of the extraneous light 4, and the transmission factor of the dimmer panel 5 is changed corresponding to the output of the optical sensor 7 through an amplifier device 8, and a driving device 9.
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