Patent ID: 8493297
Filing Date: 2013-07-23
Classification: H05B,Y02B

Abstract:
1. An OLED driver for driving at least one organic electroluminescence element, comprising: a square-wave voltage source that generates a square-wave voltage of which polarity is periodically inverted and applies the voltage to the element, said voltage being approximately equal to a drive voltage of the element; a controller that controls the source so as to change the frequency of the voltage to change and adjust a light output of the element; and a detector that is connected in series with the element and substantially detects a value of an electric current flowing through the element, wherein, based on the value of the electric current, the controller changes the frequency of the voltage so that the value of the electric current flowing through the element agrees with a target electric current value, wherein the driver further comprises a current-limiting element that is an inductor connected in series with the organic electroluminescence element and the detector, wherein a peak value of an inrush current after the square-wave voltage is inverted to positive polarity from negative polarity is limited to a current out of emission of the organic electroluminescence element through the current-limiting element, and a term for which the inrush current is flowing is nearly constant without depending on the frequency of the square-wave voltage, and thereby light output of the organic electroluminescence element is more decreased as the frequency of the square-wave voltage is more raised.