OLED LUMINANCE DEGRADATION COMPENSATION
First Claim
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1. A method of compensating for luminance degradation of a pixel having a luminescent device, the method comprising:
- determining the capacitance of the electroluminescent device;
correlating the determined capacitance of the electroluminescent device to a current correction factor for the electroluminescent device;
compensating a drive current for the luminescent device according to the correlated current correction factor; and
driving the luminescent device with the compensated drive current.
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Abstract
A system and method are disclosed for determining a pixel capacitance. The pixel capacitance is correlated to a pixel age to determine a current correction factor used for compensating the pixel drive current to account for luminance degradation of the pixel that results from the pixel aging.
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Citations
17 Claims
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1. A method of compensating for luminance degradation of a pixel having a luminescent device, the method comprising:
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determining the capacitance of the electroluminescent device; correlating the determined capacitance of the electroluminescent device to a current correction factor for the electroluminescent device; compensating a drive current for the luminescent device according to the correlated current correction factor; and driving the luminescent device with the compensated drive current. - View Dependent Claims (2)
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3. A method of driving a pixel with a current compensated for luminance degradation of the pixel, the method comprising:
- determining a capacitance of the pixel;
correlating the determined capacitance of the pixel to a current correction factor for the pixel;
compensating a pixel drive current according to the current correction factor; and
driving the pixel with the compensated current.
- determining a capacitance of the pixel;
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4. A display for driving an array of a plurality of pixel circuits with a current compensated for luminance degradation, each of said pixel circuits having a luminescent device, the display comprising:
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a display panel comprising the array of pixel circuits, the pixel circuits arranged in at least one row and a plurality of columns; a column driver for driving the luminescent devices in the pixel circuits with a driving current; a read block for determining the capacitance of an electroluminescent device and correlating the determined capacitance of the electroluminescent device to a current correction factor for the electroluminescent device; and a control block for controlling the operation of the column driver and the read block, the control block being operable to adjust the driving current based on the correlated current correction factor, and to drive the luminescent device with the compensated drive current. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12)
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13. A method of determining the capacitance of an electroluminescent device;
- wherein the step of determining the capacitance of the luminescent device comprises;
charging the capacitance of the luminescent device to a first voltage V1;
charging a parasitic capacitance to a second voltage V2;
electrically connecting the parasitic capacitance and the luminescent device capacitance in parallel; and
measuring a voltage change, Δ
V, across a read capacitor of capacitance Cread;
wherein the luminescent device capacitance is equal to;
- wherein the step of determining the capacitance of the luminescent device comprises;
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14. A method of compensating the capacitance of an electroluminescent device to a current correction factor for the electroluminescent device;
- compensating a drive current for the luminescent device according to the correlated current correction factor; and
driving the luminescent device with the compensated drive current
- compensating a drive current for the luminescent device according to the correlated current correction factor; and
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15. A read block for use in determining a pixel capacitance of a plurality of pixel circuits, the pixel circuits arranged in an array to form a display, the read block comprising:
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a plurality of read block elements, each read block element comprising; a switch for electrically connecting and disconnecting the read block element to a pixel circuit of the plurality of pixel circuits; an operational amplifier electrically connected to the switch; and a read capacitor connected in parallel with the operational amplifer. - View Dependent Claims (16, 17)
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Specification