Display device and method of driving the same
View Patent ↗A display device includes a voltage drop amount calculating circuit that regulates a power source voltage, a power wire network in the organic EL display unit includes a row-wise resistance component Rah and a column-wise resistance component Rav, and the voltage drop amount calculating circuit divides the organic EL display unit into blocks each made up of pixels in Xv rows and Xh columns, and sets, for each of the blocks, a row-wise resistance component Rah′ to a value obtained by multiplying the resistance component Rah by (Xh/Xv), and sets, for each of the blocks, a column-wise resistance component Rav′ to a value obtained by multiplying the resistance component Rav by (Xv/Xh), thereby estimating a distribution, for the respective blocks, of amounts of voltage drop which occurs in the power wire, and regulates, based on the distribution, a voltage to be supplied to the display unit.
1. A display device, comprising:
a display including a plurality of pixels arranged in rows and columns;
a voltage source that supplies a power source voltage to the display; and
a voltage regulator configured to regulate a voltage to be supplied to the display, according to video data indicating a luminance of each of the pixels,
wherein the display further includes one or more power wires connected to the pixels and the voltage source and through which the power source voltage is supplied from the voltage source, the one or more power wires each including a pixel row resistance component that is a row-wise resistance component for each of the pixels and a pixel column resistance component that is a column-wise resistance component for each of the pixels, and
the voltage regulator is configured to:
divide the pixels into first blocks each made up of pixels in Xv rows and Xh columns where Xv and Xh are integers of 2 or greater, and set the power wires to transfer the power source voltage for each of the first blocks;
set a first block row resistance component to a value obtained by multiplying the pixel row resistance component by Xh/Xv, and set a first block column resistance component to a value obtained by multiplying the pixel column resistance component by Xv/Xh, the first block row resistance component being a row-wise resistance component of each of the power wires for each of the first blocks, the first block column resistance component being a column-wise resistance component of each of the power wires for each of the first blocks;
set the Xv and the Xh with which the first block column resistance component and the first block row resistance component are equal; and
estimate a voltage drop amount distribution for the first blocks that is a distribution of amounts of voltage drop which occurs in the power wires when a current dependent on the video data flows through each of the first blocks, and regulate, based on the estimated voltage drop amount distribution, the voltage to be supplied to the display.
2. The display device according to claim 1 ,
wherein the voltage which is regulated by the voltage regulator is the power source voltage.
3. The display device according to claim 1 ,
wherein the voltage which is regulated by the voltage regulator is a signal voltage which results from conversion of the video data and is to be applied to each of the pixels.
4. The display device according to claim 1 ,
wherein the voltage which is regulated by the voltage regulator is the power source voltage and a signal voltage which results from conversion of the video data and is to be applied to each of the pixels.
5. The display device according to claim 1 ,
wherein the voltage regulator is further configured to:
divide the pixels into second blocks each made up of pixels in Yv rows and Yh columns where Yv is an integer of 2 or greater which is different from Xv and Yh is an integer of 2 or greater which is different from Xh, and set the power wires to transfer the power source voltage for each of the second blocks;
set a second block row resistance component to a value obtained by multiplying the pixel row resistance component by Yh/Yv, and set a second block column resistance component to a value obtained by multiplying the pixel column resistance component by Yv/Yh, the second block row resistance component being a row-wise resistance component of each of the power wires for each of the second blocks, the second block column resistance component being a column-wise resistance component of each of the power wires for each of the second blocks;
estimate a voltage drop amount distribution for the second blocks that is a distribution of amounts of voltage drop which occurs in the power wires when a current dependent on the video data flows through each of the second blocks; and
estimate a voltage drop amount distribution for the pixels from the voltage drop amount distribution estimated for the first blocks and the voltage drop amount distribution estimated for the second blocks.
6. The display device according claim 1 ,
wherein the voltage regulator is configured to regulate the voltage using a maximum value in the estimated voltage drop amount distribution for the first blocks.
7. The display device according to claim 1 ,
wherein the voltage source supplies a first voltage and a second voltage to the display unit, the second voltage being different from the first voltage,
the one or more power wires include a first power wire through which the first voltage is supplied and a second power wire through which the second voltage is supplied, and
the voltage regulator is configured to estimate a first distribution and a second distribution for the first blocks, and regulate the first voltage and the second voltage based on the first distribution and the second distribution, respectively, the first distribution being a distribution of amounts of voltage drop which occurs in the first power wire, the second distribution being a distribution of amounts of voltage drop which occurs in the second power wire.
8. The display device according to claim 7 ,
wherein the voltage regulator is configured to regulate the first voltage and the second voltage according to a sum of a maximum value in the first distribution and a maximum value in the second distribution.
9. The display device according to claim 7 ,
wherein the voltage regulator is configured to compute a total voltage drop amount distribution by adding up the first distribution and the second distribution for the respective first blocks, and regulate the first voltage and the second voltage based on the computed total voltage drop amount distribution, the total voltage drop amount distribution being a sum of the amounts of voltage drop which occurs in the first power wire and the amounts of voltage drop which occurs in the second power wire.
10. The display device according to claim 9 ,
wherein the voltage regulator is configured to regulate the first voltage and the second voltage using a maximum value in the total voltage drop amount distribution.
11. The display device according to claim 1 ,
wherein each of the pixels includes a driver and a light-emitting element,
the driver includes a source electrode and a drain electrode,
the light-emitting element includes a first electrode and a second electrode, the first electrode being connected to one of the source electrode and the drain electrode of the driver, 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 wire, 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 wire.
12. The display device according to claim 11 ,
wherein the second electrode forms a part of a common electrode provided in common with the pixels, and
the common electrode is electrically connected to the voltage source to allow a potential to be applied from a periphery of the common electrode.
13. The display device according to claim 12 ,
wherein the second electrode is formed of a transparent conductive material made of a metal oxide.
14. The display device according to claim 11 ,
wherein the light-emitting element is an organic electroluminescence (EL) element.
15. A method of driving a display device, which includes a display including a plurality of pixels arranged in rows and columns, and a voltage source that supplies a power source voltage to the display, the display further including one or more power wires connected to the pixels and the voltage source and through which the power source voltage is supplied from the voltage source, the one or more power wires each including a pixel row resistance component that is a row-wise resistance component for each of the pixels and a pixel column resistance component that is a column-wise resistance component for each of the pixels, the method comprising:
dividing the pixels into first blocks each made up of pixels in Xv rows and Xh columns where Xv and Xh are integers of 2 or greater, and setting the power wires to supply the power source voltage for each of the first blocks, wherein, in the dividing, the Xv and the Xh are set with which the first block column resistance component and the first block row resistance component are equal;
setting a first block row resistance component to a value obtained by multiplying the pixel row resistance component by Xh/Xv, and setting a first block column resistance component to a value obtained by multiplying the pixel column resistance component by Xv/Xh, the first block row resistance component being a row-wise resistance component of each of the power wires for each of the first blocks, the first block column resistance component being a column-wise resistance component of each of the power wires for each of the first blocks;
estimating a voltage drop amount distribution for the first blocks that is a distribution of amounts of voltage drop which occurs in the power wires when a current dependent on video data flows through each of the first blocks; and
regulating, based on the voltage drop amount distribution estimated in the estimating, a voltage to be supplied to the display.
16. The method of driving a display device according to claim 15 ,
wherein, in the regulating, the power source voltage is regulated based on the voltage drop amount distribution estimated in the estimating.
17. The method of driving a display device according to claim 15 ,
wherein, in the regulating, a signal voltage which results from conversion of the video data and is to be applied to each of the pixels is regulated based on the voltage drop amount distribution estimated in the estimating.
18. The method of driving a display device according to claim 15 ,
wherein, in the regulating, the power source voltage and a signal voltage to be applied to each of the pixels are regulated based on the voltage drop amount distribution estimated in the estimating.
19. A display device, comprising:
a display including a plurality of pixels arranged in rows and columns;
a voltage source that supplies a power source voltage to the display; and
a voltage regulator configured to regulate a voltage to be supplied to the display, according to video data indicating a luminance of each of the pixels,
wherein the display further includes one or more power wires connected to the pixels and the voltage source and through which the power source voltage is supplied from the voltage source, the one or more power wires each including a pixel row resistance component that is a row-wise resistance component for each of the pixels and a pixel column resistance component that is a column-wise resistance component for each of the pixels, and
the voltage regulator is configured to:
divide the pixels into first blocks each made up of pixels in Xv rows and Xh columns where Xv and Xh are integers of 2 or greater, and set the power wires to transfer the power source voltage for each of the first blocks;
set a first block row resistance component to a value obtained by multiplying the pixel row resistance component by Xh/Xv, and set a first block column resistance component to a value obtained by multiplying the pixel column resistance component by Xv/Xh, the first block row resistance component being a row-wise resistance component of each of the power wires for each of the first blocks, the first block column resistance component being a column-wise resistance component of each of the power wires for each of the first blocks;
estimate a voltage drop amount distribution for the first blocks that is a distribution of amounts of voltage drop which occurs in the power wires when a current dependent on the video data flows through each of the first blocks, and regulate, based on the estimated voltage drop amount distribution, the voltage to be supplied to the display;
divide the pixels into second blocks each made up of pixels in Yv rows and Yh columns where Yv is an integer of 2 or greater which is different from Xv and Yh is an integer of 2 or greater which is different from Xh, and set the power wires to transfer the power source voltage for each of the second blocks;
set a second block row resistance component to a value obtained by multiplying the pixel row resistance component by Yh/Yv, and set a second block column resistance component to a value obtained by multiplying the pixel column resistance component by Yv/Yh, the second block row resistance component being a row-wise resistance component of each of the power wires for each of the second blocks, the second block column resistance component being a column-wise resistance component of each of the power wires for each of the second blocks;
estimate a voltage drop amount distribution for the second blocks that is a distribution of amounts of voltage drop which occurs in the power wires when a current dependent on the video data flows through each of the second blocks; and
estimate a voltage drop amount distribution for the pixels from the voltage drop amount distribution estimated for the first blocks and the voltage drop amount distribution estimated for the second blocks.
20. A display device, comprising:
a display including a plurality of pixels arranged in rows and columns;
a voltage source that supplies a power source voltage to the display; and
a voltage regulator configured to regulate a voltage to be supplied to the display, according to video data indicating a luminance of each of the pixels,
wherein the display further includes one or more power wires connected to the pixels and the voltage source and through which the power source voltage is supplied from the voltage source, the one or more power wires each including a pixel row resistance component that is a row-wise resistance component for each of the pixels and a pixel column resistance component that is a column-wise resistance component for each of the pixels, and
the voltage regulator is configured to:
divide the pixels into first blocks each made up of pixels in Xv rows and Xh columns where Xv and Xh are integers of 2 or greater, and set the power wires to transfer the power source voltage for each of the first blocks;
set a first block row resistance component to a value obtained by multiplying the pixel row resistance component by Xh/Xv, and set a first block column resistance component to a value obtained by multiplying the pixel column resistance component by Xv/Xh, the first block row resistance component being a row-wise resistance component of each of the power wires for each of the first blocks, the first block column resistance component being a column-wise resistance component of each of the power wires for each of the first blocks; and
estimate a voltage drop amount distribution for the first blocks that is a distribution of amounts of voltage drop which occurs in the power wires when a current dependent on the video data flows through each of the first blocks, and regulate, based on the estimated voltage drop amount distribution, the voltage to be supplied to the display,
wherein the voltage source supplies a first voltage and a second voltage to the display unit, the second voltage being different from the first voltage,
the one or more power wires include a first power wire through which the first voltage is supplied and a second power wire through which the second voltage is supplied, and
the voltage regulator is configured to estimate a first distribution and a second distribution for the first blocks, and regulate the first voltage and the second voltage based on the first distribution and the second distribution, respectively, the first distribution being a distribution of amounts of voltage drop which occurs in the first power wire, the second distribution being a distribution of amounts of voltage drop which occurs in the second power wire.