Display device
View Patent ↗A display device according to the present disclosure includes: a variable-voltage source supplying power source voltage; an organic EL display unit including power lines on high-potential side and low-potential side that are connected to pixels; a potential difference detecting circuit detecting a potential on the high-potential side of a monitor pixel; a voltage drop amount calculating circuit calculating an amount of voltage drop generated in the power line on the low-potential side from video data and estimating a potential at, at least one point of the power line on the low-potential side; and a signal processing circuit regulating power source voltage to be supplied from the variable voltage source such that a potential difference between the potential on the high-potential side detected by the potential difference detecting circuit and the potential on the low-potential side estimated by the voltage drop amount calculating circuit reaches a predetermined potential difference.
1. A display device, comprising:
a power supply configured to supply an output potential on a high-potential side and an output potential on a low-potential side;
a display including:
a plurality of pixels arranged in a matrix;
a power line on the high-potential side and a power line on the low-potential side that are connected to each of the pixels, and configured to receive power from the power supply;
a voltage detector configured to detect a potential on one of the high-potential side and the low-potential side among potentials applied to at least one of the pixels in the display;
a voltage estimator configured to calculate an amount of voltage drop generated in the power line on the other of the high-potential side and the low-potential side from video data, which is data indicating luminance of each of the pixels, and to estimate a potential at, at least one point of the power line; and
a voltage regulator configured to regulate at least one output potential on one of the high-potential side and the low-potential side to be supplied from the power supply such that a potential difference between the potential on one of the high-potential side and the low-potential side detected by the voltage detector and the potential at the at least one point of the power line estimated by the voltage estimator reaches a predetermined potential difference, wherein
each of the pixels includes a driver and a light-emitting element,
the voltage regulator is configured to regulate the at least one output potential to reduce a drive voltage of the driver within a range in which the driver operates in a saturation region and the light-emitting element emits light substantially at the luminance, and
the predetermined potential difference is represented by VTFT+VEL+Vdrop−ΔV, where VTFT indicates a voltage required for the driver, VEL indicates a voltage required for the light-emitting element, ΔV indicates a potential difference between a potential output from the power supply and a potential detected by the voltage detector, and Vdrop indicates a voltage margin corresponding to ΔV.
2. The display device according to claim 1 , wherein the voltage estimator is configured to calculate a distribution of the amount of voltage drop for each of first blocks, and to estimate, for each pixel, an amount of voltage drop generated on the power line on the other of the high-potential side and the low-potential side for each pixel, based on the distribution of the amount of voltage drop calculated for the first blocks, each of the first blocks including M pixels obtained by dividing the number of pixels in a row direction and a column direction to be equal, where M is an integer equal to or greater than 2.
3. The display device according to claim 2 , wherein the voltage estimator is further configured (i) to calculate a distribution of the amount of voltage drop for each of second blocks including N pixels obtained by dividing the number of pixels in the column direction and the row direction to be equal, where N is an integer equal to or greater than 2 and is different from M, and (ii) to estimate an amount of voltage drop on the power line on the other of the high-potential side and the low-potential side, based on the distribution of the amount of voltage drop calculated for the first blocks and the distribution of the amount of voltage drop calculated for the second blocks.
4. The display device according to claim 1 , wherein the voltage regulator regulates the at least one output potential on the high-potential side and the low-potential side to be supplied from the power supply, using a largest value in the distribution of the amount of voltage drop estimated.
5. The display device according to claim 1 , wherein the voltage detector is configured to detect potentials of the plurality of pixels in the display.
6. The display device according to claim 5 , wherein the voltage regulator is configured to select a smallest potential of potentials on the high-potential side detected by the voltage detector or a largest potential of potentials on the low-potential side detected by the voltage detector, and to regulate the power supply based on the selected potential.
7. The display device according to claim 1 , further comprising:
a high-potential side detecting line having one end connected to the pixel at which the potential on the high-potential side is detected and the other end connected to the voltage regulator, and transmitting the potential on the high-potential side; or
a low-potential side detecting line having one end connected to the pixel at which the potential on the low-potential side is detected and the other end connected to the voltage regulator, and transmitting the potential on the low-potential side.
8. The display device according to claim 1 ,
wherein each of the pixels includes:
a driving element including a source electrode and a drain electrode; and
a light-emitting element including a first electrode and a second electrode,
the first electrode is connected to one of the source electrode and the drain electrode of the driving element, one of (i) the other of the source electrode and the drain electrode and (ii) the second electrode is connected to one of the power lines on the high-potential side and the low-potential side, and the other of the source electrode and the drain electrode and the other of the second electrode are connected to the other of the power lines on the high-potential side and the low-potential side.
9. The display device according to claim 8 ,
wherein the second electrode configures a part of a common electrode provided in common with the pixels, and
the common electrode is electrically connected to the power supply such that the potential is applied from a periphery of the common electrode.
10. The display device according to claim 9 , wherein the second electrode is a transparent conductive material of a metal oxide.
11. The display device according to claim 8 , wherein the light-emitting element is an organic EL element.
12. The display device according to claim 1 , wherein the output potential regulation reduces power consumption of each of the pixels without substantially changing the luminance.
13. A display device, comprising:
a power supply configured to supply an output potential on a high-potential side and an output potential on a low-potential side;
a display including:
a plurality of pixels arranged in a matrix;
a power line on the high-potential side and a power line on the low-potential side that are connected to each of the pixels, and configured to receive power from the power supply;
a voltage detector configured to detect a potential on one of the high-potential side and the low-potential side among potentials applied to at least one of the pixels in the display;
a voltage estimator configured to calculate an amount of voltage drop generated in the power line on the other of the high-potential side and the low-potential side from video data which is data indicating luminance of each of the pixels, and to estimate a potential at, at least one point of the power line; and
a voltage regulator configured to regulate at least one output potential on one of the high-potential side and the low-potential side to be supplied from the power supply such that a potential difference between the potential on one of the high-potential side and the low-potential side detected by the voltage detector and the potential at the at least one point of the power line estimated by the voltage estimator reaches a predetermined potential difference, wherein
each of the pixels includes a driver and a light-emitting element,
the voltage regulator is configured to regulate the at least one output potential such that as the at least one output potential increases the potential difference also increases, and
the predetermined potential difference is represented by VTFT+VEL+Vdrop−ΔV, where VTFT indicates a voltage required for the driver, VEL indicates a voltage required for the light-emitting element, ΔV indicates a potential difference between a potential output from the power supply and a potential detected by the voltage detector, and Vdrop indicates a voltage margin corresponding to ΔV.
14. The display device according to claim 13 , wherein voltage regulator is configured to regulate the output potential to reduce a drive voltage of the driver within a range in which the driver operates in a saturation region and the light-emitting element emits light substantially at the luminance.
15. The display device according to claim 14 , wherein the output potential regulation reduces power consumption of each of the pixels without substantially changing the luminance.
16. A display device, comprising:
a power supply configured to supply an output potential on a high-potential side and an output potential on a low-potential side;
a display including:
a plurality of pixels arranged in a matrix;
a power line on the high-potential side and a power line on the low-potential side that are connected to each of the pixels, and configured to receive power from the power supply and to supply a driving current to the pixels;
a voltage detector configured to detect a potential on one of the high-potential side and the low-potential side among potentials applied to at least one of the pixels in the display;
a voltage estimator configured to calculate an amount of voltage drop generated in the power line on the other of the high-potential side and the low-potential side from video data, which is data indicating luminance of each of the pixels, and to estimate a potential at, at least one point of the power line; and
a voltage regulator configured to regulate at least one output potential on one of the high-potential side and the low-potential side to be supplied from the power supply such that a potential difference between the potential on one of the high-potential side and the low-potential side detected by the voltage detector and the potential at the at least one point of the power line estimated by the voltage estimator reaches a predetermined potential difference, wherein
each of the pixels includes a driver and a light-emitting element,
the display further includes:
a high-potential side detecting line having one end connected to the pixel at which the potential on the high-potential side is detected and the other end connected to the voltage regulator, and for transmitting the potential on the high-potential side; or
a low-potential side detecting line having one end connected to the pixel at which the potential on the low-potential side is detected and the other end connected to the voltage regulator, and for transmitting the potential on the low-potential side and the high-potential side detecting line and the low-potential side detecting line are not capable of supplying a driving current to the pixels, and
the predetermined potential difference is represented by VTFT+VEL+Vdrop−ΔV, where VTFT indicates a voltage required for the driver, VEL indicates a voltage required for the light-emitting element, ΔV indicates a potential difference between a potential output from the power supply and a potential detected by the voltage detector, and Vdrop indicates a voltage margin corresponding to ΔV.
17. The display device according to claim 16 , wherein voltage regulator is configured to regulate the output potential to reduce a drive voltage of the driver within a range in which the driver operates in a saturation region and the light-emitting element emits light substantially at the luminance.
18. The display device according to claim 17 , wherein the output potential regulation reduces power consumption of each of the pixels without substantially changing the luminance.
19. A display device, comprising:
a power supply configured to supply an output potential on a high-potential side and an output potential on a low-potential side;
a display including:
a plurality of pixels arranged in a matrix;
a power line on the high-potential side and a power line on the low-potential side that are connected to each of the pixels, and configured to receive power from the power supply;
a voltage detector configured to detect a potential on one of the high-potential side and the low-potential side among potentials applied to at least one of the pixels in the display;
a voltage estimator configured to calculate an amount of voltage drop generated in the power line on the other of the high-potential side and the low-potential side from video data which is data indicating luminance of each of the pixels and to estimate a potential at, at least one point of the power line; and
a voltage regulator configured to regulate at least an output potential on one of the high-potential side and the low-potential side to be supplied from the power supply such that a potential difference between the potential on one of the high-potential side and the low-potential side detected by the voltage detector and the potential at the at least one point of the power line estimated by the voltage estimator reaches a predetermined potential difference, wherein
each of the pixels includes a driver and a light-emitting element,
the predetermined potential difference is represented by VTFT+VEL+Vdrop−ΔV, where VTFT indicates a voltage required for the driver, VEL indicates a voltage required for the light-emitting element, ΔV indicates a potential difference between a potential output from the power supply and a potential detected by the voltage detector, and Vdrop indicates a voltage margin corresponding to ΔV.