Method of manufacturing organic electroluminescence display device
View Patent ↗A method of manufacturing an organic electroluminescence (EL) display device includes: identifying a defective pixel which includes an organic EL element having a short defect from among the pixels; applying a reverse bias voltage within a predetermined range to the pixel identified as the defective pixel; applying, for a certain period, a predetermined voltage to the pixel to which the reverse bias voltage is already applied, and measuring light emission luminance or pixel current of the pixel; and performing another repair process on the pixel having a temporal change amount in the measured light emission luminance or pixel current that is greater than or equal to a threshold.
1. A method of manufacturing an organic electroluminescence (EL) display device which includes pixels, each of which includes an organic EL element, the method comprising:
identifying, from among the pixels, a pixel that includes an organic EL element having a short defect as a defective pixel;
applying a reverse bias voltage for eliminating the short defect to the pixel identified as the defective pixel in the identifying of the pixel, the reverse bias voltage being within a predetermined range;
applying, for a certain period, a voltage having an absolute value that is at most equal to the reverse bias voltage to the pixel to which the reverse bias voltage is already applied in the applying of the reverse bias voltage, and measuring one of a light emission luminance and a pixel current of the pixel in the certain period;
again identifying the pixel as the defective pixel that needs to be repaired when a temporal change amount in the one of the light emission luminance and the pixel current measured in the measuring is at least equal to a threshold; and
repairing, by using a laser and after the reverse bias voltage is already applied to the pixel, the pixel using a technique different from the technique of applying the reverse bias voltage, the pixel being again identified as the defective pixel.
2. The method of manufacturing the organic EL display device according to claim 1 ,
wherein in the applying of the reverse bias voltage, a leakage current is measured, and the reverse bias voltage is continuously applied until the leakage current is at most equal to a predetermined value, and
in the measuring, the voltage is applied, for the certain period, to the pixel when the leakage current is at most equal to the predetermined value, and the one of light emission luminance and the pixel current of the pixel is measured.
3. The method of manufacturing the organic EL display device according to claim 2 ,
the repairing is further performed on the pixel when the leakage current is greater than the predetermined value, even when the reverse bias voltage is applied for the certain period.
4. The method of manufacturing the organic EL display device according to claim 1 ,
wherein an absolute value of the reverse bias voltage in the predetermined range in the applying of the reverse bias voltage varies from 15 V to 25 V inclusive.
5. The method of manufacturing the organic EL display device according to claim 1 ,
wherein the temporal change amount is a value which is obtained by dividing an absolute value of a difference between the one of the light emission luminance and the pixel current that is measured in the measuring at a starting point of the certain period and the one of the light emission luminance and the pixel current that is measured in the measuring at a point of the predetermined period, by the one of the light emission luminance and the pixel current that is measured at the starting point of the predetermined period, and
the threshold is 5 percent.
6. A method of manufacturing an organic electroluminescence (EL) display device which includes pixels, each of which includes an organic EL element, the method comprising:
identifying, from among the pixels, a pixel that includes an organic EL element having a short defect as a defective pixel;
applying a reverse bias voltage for eliminating the short defect to the pixel identified as the defective pixel in the identifying of the pixel, the reverse bias voltage being within a predetermined range;
applying, for a certain period, a voltage having an absolute value that is at most equal to the reverse bias voltage to the pixel to which the reverse bias voltage is already applied in the applying of the reverse bias voltage, and measuring one of a light emission luminance and a pixel current of the pixel in the certain period;
again identifying the pixel as the defective pixel that needs to be repaired when a temporal change amount in the one of the light emission luminance and the pixel current measured in the measuring is at least equal to a threshold; and
repairing the pixel using a technique different from the technique of applying the reverse bias voltage, the pixel being again identified as the defective pixel,
wherein the temporal change amount is a value which is obtained by dividing an absolute value of a difference between the one of the light emission luminance and the pixel current that is measured in the measuring at a starting point of the certain period and the one of the light emission luminance and the pixel current that is measured in the measuring at a point of the predetermined period, by the one of the light emission luminance and the pixel current that is measured at the starting point of the predetermined period, and
the threshold is 5 percent.