A light emitting device using light emission of an electroluminescence element (light emitting element) is wide in viewing angle and low in power consumption. In recent years, a light emitting device which can provide high quality images has been actively researched and developed in view of capturing a market as a display device applicable to various information processing devices such as a television receiver and a car navigation system.
The luminance of the light emitting element decays with light emission time. Such a decay becomes notable when the light emitting element keeps emitting light at a high luminance. Such a luminance decay causes the change in display color of the light emitting device which functions as a display device, leading to degrade the image quality.
Therefore, a light emitting element with long life, of which luminance decay according to the light emission time is suppressed has been developed. For example, Patent Document 1 discloses a driving method of a light emitting element of which long life can be achieved by applying a recovering voltage. It is important to prolong the life of the light emitting element in order to provide a light emitting device which can display high quality images.
[Patent Document 1] Japanese Patent Laid-Open No. 10-55154
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