| 摘要 |
PROBLEM TO BE SOLVED: To provide an EL element drive device capable of keeping initial brightness even when a phosphor layer is deteriorated.SOLUTION: An EL element 2 has: a pair of electrodes 4, 5; a display pattern layer 6 on which a display pattern 9 impregnated with pattern formation liquid is formed; a phosphor layer 7; and a dielectric layer 8. The display pattern layer 6 is provided with a brightness confirmation pattern 11, and opposed to a light receiving element 12 provided on a cover member 10. Initial brightness detected by the light receiving element is stored in a control part 15 as an initial value. During driving, the light receiving element detects brightness of the brightness confirmation pattern, and compares the measured value with the initial value, and adjusts an alternating-current voltage applied to the EL element so that a difference between the values becomes 0. Thereby, the initial brightness is maintained even when a phosphor layer is deteriorated. |
