| 摘要 |
<p>PROBLEM TO BE SOLVED: To lengthen a lighting period of backlight without causing malfunction of a main body circuit in a display device having a back light function of a display screen with an EL(electroluminescence) panel, etc., as a light source in an electronic information equipment. SOLUTION: A backlight 18 of a liquid crystal display(LCD) part 16 is composed of two comb-like halved EL panels (1) 18a and (2) 18b in a backlighting state alternately from the right and left sides of the screen by a regular width in the vertical direction of a display screen, and when an output voltage of a battery powder source 19 is normally 5.5 volts or higher, the two EL panels (1) 18a, (2) 18b are driven to be turned on, but when the battery power source 19 is consumed and the output voltage becomes lower than 5.5 V, an output signal of low level '0' from a voltage detector DET 2 is supplied to AND gate AND 2 and the lighting drive of one EL panel (2) 18b is prohibited, but it is possible to maintain the backlight function by the lighting only of the other EL panel (1) 18a and thereby to halve the power consumption.</p> |
