Loading patent…
AssigneesNEC Corporation, NEC Electronics Corporation
InventorMasamichi Shimoda
Estimating the term…
An object of the present invention is to provide a display device for making it possible to accurately adjust a gradation current even if there is a variation in characteristics of a transistor for driving an organic EL element in a display device using an organic EL element. The following are included: a current detecting circuit for detecting a current circulating through a light emitting element, a current adjustment control circuit for comparing the detected current value with a reference current value and adjusting a current to be supplied to the light emitting element of a display portion in accordance with the comparison result, and a reference current circuit for generating a reference current correspondingly to the adjusted current. Moreover, a reference current circuit is formed on the substrate same as the substrate on which a light emitting element of a display portion is formed. Thereby, the variation of transistor devices constituting the reference current circuit is corrected and the reference current can be adjusted at a high accuracy.
A display driving circuit which comprises reference-current supplying means for supplying a current to be a reference and supplys a current to a light emitting element, said display driving circuit comprising comparing means for comparing the current supplied to the light emitting element with a target value, and adjusting means for adjusting the current of the reference-current supplying means in accordance with the comparison result.
A display driving circuit which comprises reference-current supplying means for supplying a current to be a reference and supplys a current to a light emitting element, said display driving circuit comprising storing means for previously storing an adjustment value for adjusting the reference current of the reference-current supplying means, and adjustment means for reading the adjustment value stored in the storing means and adjusting the current of the reference-current supplying means in response to power-on.
Dependencies are inferred from the claim text.