Electroluminescence display apparatus and method of correcting display variation for electroluminescence display apparatus
View Patent ↗By correcting a data signal based on a current flowing through an EL element when an element driving transistor which controls a drive current to be supplied to the EL element is operated in a saturation region and the EL element is set to an emission level, it is possible to realize a rapid display variation inspection and a high precision display variation correction. By providing a current measuring function on an EL display apparatus, a characteristic variation after the apparatus is shipped can be handled and corrected.
1. A method of correcting a display variation for an electroluminescence display apparatus comprising, in each pixel, an electroluminescence element having a diode structure and an element driving transistor which is connected to the electroluminescence element and which controls a current flowing through the electroluminescence element, the method
comprising:
supplying an inspection ON display signal which sets the electroluminescence element to an emission level to each pixel;
operating the element driving transistor in a saturation region; and detecting a current flowing through the electroluminescence element while the element driving transistor is operated in the saturation region;
wherein a data signal to be supplied to a corresponding pixel is corrected based on a value of the current flowing through the electroluminescence element, wherein the current flowing through the electroluminescence element is a cathode current;
wherein the driving transistor is configured to receive the data signal at a gate electrode and configured to control a current through the organic element in accordance with a voltage of the data signal;
the cathode current is measured when one of the EL elements is set at the emission level by the inspection ON display signal as the data signal;
the correction data for each pixel is obtained based on the measured cathode current by alternatively setting the one of the EL elements at the emission level;
the correction data for each pixel is stored in a memory;
the correction data for each pixel is used for correcting the data signal for each pixel;
the corrected data signal for each pixel is supplied to the gate electrode of the driving transistor of a corresponding pixel;
a plurality of adjacent pixels are set as the inspection target, at the same time the plurality of the adjacent pixels are in a same horizontal scan line; and a pixel of the plurality of adjacent pixels is set to be an inspection target consecutively for a plurality of times.
2. A method of correcting a display variation for an electroluminescence display apparatus comprising, in each pixel, an electroluminescence element having a diode structure and an element driving transistor which is connected to the electroluminescence element and which controls a current flowing through the electroluminescence element, the method comprising:
operating the element driving transistor of each pixel in a saturation region; and supplying an inspection ON display signal which sets the electroluminescence element to an emission level and an inspection OFF display signal which sets the electroluminescence element to a non-emission level to each pixel;
detecting an ON-OFF current difference between a current flowing through the electroluminescence element corresponding to the inspection ON display signal and a current flowing through the electroluminescence element corresponding to the inspection OFF display signal while the element driving transistor is operated in the saturation region;
the ON-OFF current difference is compared to a reference value and a characteristic variation of an operated pixel is detected, wherein the current flowing through the electroluminescence element is a cathode current; and
a data signal to be supplied to a corresponding pixel is corrected based on the detected characteristic variation;
wherein the driving transistor is configured to receive the data signal at a gate electrode and configured to control a current through the organic element in accordance with a voltage of the data signal;
the cathode current is measured when one of the EL elements is set at the emission level by the inspection ON display signal as the data signal;
the correction data for each pixel is obtained based on the measured cathode current by alternatively setting the one of the EL elements at the emission level;
the correction data for each pixel is stored in a memory;
the correction data for each pixel is used for correcting the data signal for each pixel;
the corrected data signal for each pixel is supplied to the gate electrode of the driving transistor of a corresponding pixel;
a plurality of adjacent pixels are set as the inspection target, at the same time the plurality of the adjacent pixels are in a same horizontal scan line; and a pixel of the plurality of adjacent pixels is set to be an inspection target consecutively for a plurality of times.
3. An electroluminescence display apparatus comprising:
a display section having a plurality of pixels;
a correction data storage section which stores correction data for correcting a display variation; and
a correction section which corrects the display variation, wherein each of the plurality of pixels comprises an electroluminescence element and an element driving transistor which is connected to the electroluminescence element;
the correction data storage section stores correction data for each pixel corresponding to a current flowing through the corresponding electroluminescence element when an inspection ON display signal which sets the corresponding electroluminescence element to an emission level is supplied while the corresponding element driving transistor is operated in a saturation region,
wherein the current flowing through the electroluminescence element is a cathode current; and
the correction section corrects a data signal to be supplied to each pixel based on the correction data;
wherein the driving transistor is configured to receive the data signal at a gate electrode and configured to control a current through the organic element in accordance with a voltage of the data signal;
the cathode current is measured when one of the EL elements is set at the emission level by the inspection ON display signal as the data signal;
the correction data for each pixel is obtained based on the measured cathode current by alternatively setting the one of the EL elements at the emission level;
the correction data for each pixel is stored in a memory;
the correction data for each pixel is used for correcting the data signal for each pixel;
the corrected data signal for each pixel is supplied to the gate electrode of the driving transistor of a corresponding pixel;
a plurality of adjacent pixels are set as the inspection target, at the same time the plurality of the adjacent pixels are in a same horizontal scan line; and a pixel of the plurality of adjacent pixels is set to be an inspection target consecutively for a plurality of times.
4. An electroluminescence display apparatus comprising:
a display section having a plurality of pixels;
a correction data storage section which stores correction data for correcting a display variation; and
a correction section which corrects the display variation, wherein each of the plurality of pixels comprises an electroluminescence element and an element driving transistor which is connected to the electroluminescence element;
the correction data storage section stores correction data for each pixel corresponding to an ON-OFF current difference between a current flowing through the corresponding electroluminescence element corresponding to an inspection OFF display signal which sets the corresponding electroluminescence element to a non-emission level;
and a current flowing through the corresponding electroluminescence element corresponding to an inspection ON display signal which sets the corresponding electroluminescence element to an emission level when the inspection OFF display signal and the inspection ON display signal are supplied while the corresponding element driving transistor is operated in a saturation region, wherein the current flowing through the electroluminescence element is a cathode current; and the correction section corrects a data signal to be supplied to each pixel based on the correction data;
wherein the driving transistor is configured to receive the data signal at a gate electrode and configured to control a current through the organic element in accordance with a voltage of the data signal;
the cathode current is measured when one of the EL elements is set at the emission level by the inspection ON display signal as the data signal;
the correction data for each pixel is obtained based on the measured cathode current by alternatively setting the one of the EL elements at the emission level;
the correction data for each pixel is stored in a memory;
the correction data for each pixel is used for correcting the data signal for each pixel;
the corrected data signal for each pixel is supplied to the gate electrode of the driving transistor of a corresponding pixel;
a plurality of adjacent pixels are set as the inspection target, at the same time the plurality of the adjacent pixels are in a same horizontal scan line; and a pixel of the plurality of adjacent pixels is set to be an inspection target consecutively for a plurality of times.
5. An electroluminescence display apparatus comprising:
a display section having a plurality of pixels, a variation detecting section which detects a display variation in each pixel; and a correction section which corrects the display variation, wherein each of the plurality of pixels comprises an electroluminescence element and an element driving transistor which is connected to the electroluminescence element;
the variation detecting section detects an ON-OFF current difference for each pixel between a current flowing through the corresponding electroluminescence element corresponding to an inspection OFF display signal which sets the corresponding electroluminescence element to a non-emission level; and
a current flowing through the corresponding electroluminescence element corresponding to an inspection ON display signal which sets the corresponding electroluminescence element to an emission level when the inspection OFF display signal; and the inspection ON display signal are supplied while the corresponding element driving transistor is operated in a saturation region, and compares the detected ON-OFF current difference to a reference value, wherein the current flowing through the electroluminescence element is a cathode current; and
the correction section corrects a data signal to be supplied to each pixel based on a result of the comparison;
wherein the driving transistor is configured to receive the data signal at a gate electrode and configured to control a current through the organic element in accordance with a voltage of the data signal;
the cathode current is measured when one of the EL elements is set at the emission level by the inspection ON display signal as the data signal;
the correction data for each pixel is obtained based on the measured cathode current by alternatively setting the one of the EL elements at the emission level;
the correction data for each pixel is stored in a memory;
the correction data for each pixel is used for correcting the data signal for each pixel;
the corrected data signal for each pixel is supplied to the gate electrode of the driving transistor of a corresponding pixel;
a plurality of adjacent pixels are set as the inspection target, at the same time the plurality of the adjacent pixels are in a same horizontal scan line; and a pixel of the plurality of adjacent pixels is set to be an inspection target consecutively for a plurality of times.
6. The electroluminescence display apparatus according to claim 5 , further comprising:
a storage section which stores initial current difference data for the ON-OFF current difference, wherein
the correction section corrects the data signal based on the initial current difference data and the detected ON-OFF current difference.
7. The electroluminescence display apparatus according to claim 5 , further comprising:
a correction data storage section which stores correction data corresponding to the ON-OFF current difference, wherein
the correction section corrects the data signal based on the stored ON-OFF current difference.
8. The electro luminescence display apparatus according to claim 7 , further comprising:
a storage section which stores initial current difference data for the ON-OFF current difference, wherein
the correction section corrects the data signal based on the initial current difference data and the detected ON-OFF current difference.