To provide a display device using light-emitting diodes (LEDs), which endures a serge voltage from an AC input and thermal stress, while assuring stable illuminance.
In the display device using an LED including: a rectifying circuit 2 for rectifying an AC input of a commercial alternate current(AC) voltage, and outputting it; and a plurality of LEDs 3 connected in series with this output used as input, a varistor 5 is connected between lines of AC input, and an overheat protective circuit 6 is connected to the plurality of LEDs 3 in series. Breakdown of the display device is prevented by preventing serge voltage from flowing from the commercial AC power supply by the varistor 5. The display device uses the LEDs with excellent reliability, which can prevent heat from being generated and raised to a prescribed temperature or more, by the overheat protective circuit 6.
DHS CO LTD
CREATIVE DAIWA CO LTD
Yasuo Ishikawa
Kazuyuki Oku
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