Patent ID: 6817123
Filing Date: 2004-11-16
Classification: G09F

Abstract:
A display device comprising:a display surface portion comprising a light emitting area on which a plurality of light emitting elements are located with spaces therebetween, said spaces defining a nonluminous area on which a nonluminous image is located and visible without the light emitting elements; emission means for selectively causing at least one of the light emitting elements to emit light for displaying a luminous image on the display surface portion; means for sensing illumination density on the display surface portion; and a timer for generating a power supply start signal at a first predetermined time and a power supply stop signal at a second predetermined time, wherein said emission means comprises: means for starting to supply power to said at least one of the light emitting elements when the power supply start signal is generated by the timer; means for stopping supplying power to said at least one of the light emitting elements when the power supply stop signal is generated by the timer; means for switching off power to said at least one of the light emitting elements when, while power is supplied to said at least one of the light emitting elements according to the power supply start signal from the timer, the sensed illumination density is larger than a predetermined threshold illumination density; and means for switching on power to said at least one light emitting element when, while no power is supplied to said at least one of the light emitting elements as a result of control caused by the power supply stop signal from the timer, the sensed illumination density is smaller than a predetermined threshold illumination density.