Granted Patent B2

US 8,933,923 · App. 13/601,839 · Granted Jan 13, 2015

Abstract

Claims (45)

1. A display device comprising:

a display unit having a plurality of pixels that are arranged two-dimensionally;

a voltage source which supplies a voltage to the display unit; and

a voltage regulating unit configured to regulate the voltage output by the voltage source, according to video data indicating luminance of each of the pixels, wherein:

the display unit further includes at least one power source line connected to the pixels and the voltage source, for supplying the voltage from the voltage source, and

the voltage regulating unit is configured to calculate, from the video data, a distribution of voltage drop amount in the at least one power source line for first blocks each including M pixels obtained by dividing the pixels equally in a column direction and a row direction, where M is an integer greater than or equal to 2, estimate the distribution of the voltage drop amount for each of the pixels based on the distribution of the voltage drop amount calculated for each of the first blocks, and regulate the voltage based on the estimated distribution of the voltage drop amount for each of the pixels.

2. The display device according to claim 1 ,

wherein the voltage regulating unit is further configured to calculate a distribution of the voltage drop amount for second blocks each including N pixels obtained by dividing the pixels equally in a column direction and a row direction, and to estimate the distribution of the voltage drop amount for each of the pixels, based on the distribution of the voltage drop amount calculated for each of the first blocks and the distribution of the voltage drop amount calculated for each of the second blocks, where N is an integer different from M and greater than or equal to 2.

3. The display device according to claim 1 ,

wherein the voltage regulating unit is configured to regulate the voltage, using a maximum value of the estimated distribution of the voltage drop amount for each of the pixels.

4. The display device according to claim 1 , wherein:

the voltage source supplies, to the display unit, a first voltage and a second voltage different from the first voltage,

the at least one power source line includes a first power source line for supplying the first voltage and a second power source line for supplying the second voltage, and

the voltage regulating unit is configured to estimate a first distribution and a second distribution for each of the pixels, the first distribution being a distribution of the voltage drop amount in the first power source line, the second distribution being a distribution of the voltage drop amount in the second power source line, and to regulate the first voltage and the second voltage, based on a first distribution and a second distribution for each of the pixels estimated, respectively.

5. The display device according to claim 4 ,

wherein the voltage regulating unit is configured to regulate the first voltage and the second voltage, using a sum of a maximum value of the first distribution and a maximum value of the second distribution.

6. The display device according to claim 4 ,

wherein the voltage regulating unit is configured to calculate a total voltage drop amount which is a sum of the voltage drop amount in the first power source line and the voltage drop amount in the second power source line, by adding the first distribution and the second distribution for each of the pixels, and to regulate the first voltage and the second voltage, based on the distribution of the total voltage drop amount calculated.

7. The display device according to claim 6 ,

wherein the voltage regulating unit is configured to regulate the first voltage and the second voltage, using a maximum value of the distribution of the total voltage drop amount calculated.

8. The display device according to claim 4 ,

wherein each of the pixels includes a driver element and a light-emitting element,

the driver element includes a source electrode and a drain electrode,

the light-emitting element includes a first electrode and a second electrode, and the first electrode is connected to one of the source electrode and the drain electrode of the driver element, and

one of (i) the other of the source electrode and the drain electrode and (ii) the second electrode is connected to the first power source line, and the other of (i) the other of the source electrode and the drain electrode and (ii) the second electrode is connected to the second power source line.

9. The display device according to claim 8 ,

wherein the second electrode is a part of a common electrode provided in common to the pixels, and

the common electrode is electrically connected to the voltage source such that a potential is applied from a periphery of the common electrode.

10. The display device according to claim 9 ,

wherein the second electrode is formed of a transparent conductive material made of a metal oxide.

11. The display device according to claim 8 ,

wherein the light-emitting element is an organic electroluminescence (EL) element.

12. A method for driving a display device including a display unit having a plurality of pixels that are arranged two-dimensionally, voltage source which supplies a voltage to the display unit, and a voltage regulating unit which regulates the voltage output by the voltage source, according to video data indicating luminance of each of the pixels, the display unit further including at least one power source line connected to the pixels and the voltage source, for supplying the voltage from the voltage source, the method comprising steps of:

estimating, by the voltage regulating unit, a distribution of voltage drop amount in the at least one power source line for each of the pixels from the video data which is data indicating luminance of each of the pixels; and

regulating, by the voltage regulating unit, the voltage based on the distribution of voltage drop amount estimated for each of the pixels,

wherein the step of estimating includes:

calculating, by the voltage regulating unit, a distribution of the voltage drop amount for first blocks each including M pixels, obtained by dividing the pixels equally in a row direction and a column direction, where M is an integer greater than or equal to 2;

calculating, by the voltage regulating unit, a distribution of the voltage drop amount for second blocks each including N pixels, obtained by dividing the pixels equally in a row direction and a column direction, where N is an integer different from M and greater than or equal to 2; and

sub-estimating, by the voltage regulating unit, the distribution of the voltage drop amount for each of the pixels, based on the distribution of the voltage drop amount calculated for each of the first blocks and the distribution of the voltage drop amount calculated for each of the second blocks.

13. A display device comprising:

a display unit having a plurality of pixels that are arranged two-dimensionally;

a voltage source which supplies a voltage to the display unit; and

a voltage regulating unit configured to regulate the voltage output by the voltage source, according to video data indicating luminance of each of the pixels, wherein:

the display unit further includes at least one power source line connected to the pixels and the voltage source, for supplying the voltage from the voltage source, and

the voltage regulating unit is configured to calculate, from the video data, a distribution of voltage drop amount in the at least one power source line for first blocks each including M pixels obtained by dividing the pixels in a column direction and a row direction, where M is an integer greater than or equal to 2, estimate the distribution of the voltage drop amount for each of the pixels based on the distribution of the voltage drop amount calculated for each of the first blocks, and regulate the voltage based on the estimated distribution of the voltage drop amount for each of the pixels.

Assignments (6)