Display device

Patent metadata

Field	Value
Publication number	US-11645958-B2
Application number	US-202117542019-A
Country	US
Kind code	B2
Filing date	Dec 3, 2021
Priority date	Dec 30, 2020
Publication date	May 9, 2023
Grant date	May 9, 2023

Abstract

A display device can include a display panel including a plurality of subpixels; a feedback part; and a power source configured to output a first power voltage to the feedback part and the display panel, in which the feedback part is configured to output a virtual feedback voltage to the power source, the virtual feedback voltage being based on the first power, and the power source is further configured to adjust a magnitude of the first power voltage to generate an adjusted first power voltage based on the virtual feedback voltage.

First claim

What is claimed is:

1. A display device, comprising:
a display panel including a plurality of subpixels;
a feedback part;
a power source configured to output a first power voltage to the feedback part and the display panel; and
a timing controller configured to supply a synchronization signal to the feedback part, and supply image data to the feedback part,
wherein the feedback part is configured to output a virtual feedback voltage to the power source, the virtual feedback voltage being based on the first power voltage,
wherein the feedback part is further configured to output the virtual feedback voltage based on at least one of the image data and the synchronization signal, and
wherein the power source is further configured to adjust a magnitude of the first power voltage to generate an adjusted first power voltage based on the virtual feedback voltage.

2. The display device according to claim 1 , further comprising:
a memory configured to store one or more values,
wherein the feedback part is further configured to:
receive a value from the memory, the value being based on the at least one of the synchronization signal and the image data, and
output virtual feedback voltage based on the value.

3. The display device according to claim 1 , wherein the feedback part includes:
a controller configured to generate a control signal based on the image data and the synchronization signal; and
a virtual feedback voltage generator configured to generate the virtual feedback signal based on the control signal,
wherein the virtual feedback voltage generator includes:
a generator circuit configured to generate an output signal that increases or decreases based on the control signal from the controller; and
a generator configured to generate the virtual feedback voltage based on both of the output signal from the generator circuit and the first power voltage.

4. The display device according to claim 3 , wherein the generator includes:
a transistor including a gate electrode configured to receive the output signal;
a drain electrode configured to receive the first power voltage; and
a source electrode configured to output the virtual feedback voltage.

5. The display device according to claim 4 , wherein the transistor is configured to operate as a source follower to increase the virtual feedback voltage when the output signal is increased and increase the virtual feedback voltage when the first power voltage is increased.

6. The display device according to claim 4 , wherein the transistor is disposed in the display panel.

7. The display device according to claim 3 , wherein the generator includes:
a subtractor configured to output a difference between the output signal and the first power voltage, and
wherein the feedback part is further configured to output the virtual feedback voltage based on the difference.

8. The display device according to claim 7 , wherein the subtractor is an operational amplifier.

9. The display device according to claim 3 , wherein the generator includes:
an adder configured to output a sum of the output signal and the first power voltage, and
wherein the feedback part is further configured to output the virtual feedback voltage based on the sum.

10. The display device according to claim 3 , wherein the generator includes:
a subtractor configured to output a difference between the output signal and the first power voltage;
an adder configured to output a sum of the output signal and the first power voltage; and
a plurality of switches configured to selectively transmit an output of the subtractor or an output of the adder based on one or more selection signals received from the timing controller, and
wherein the feedback part is further configured to output the virtual feedback voltage based on the difference from the subtractor or the sum from the adder.

11. The display device according to claim 3 , wherein the timing controller is configured to drive the plurality of subpixels in a frame period including a blank period and an emission period, and
wherein the generator circuit is further configured to:
increase the output signal during the blank period and decrease the output signal during the emission period, or
decrease the output signal during the blank period and increase the output signal during the emission period.

12. The display device according to claim 3 , wherein the power source includes an error amplifier configured to amplify a difference between the virtual feedback voltage and a reference voltage.

13. The display device according to claim 12 , wherein when a magnitude of the virtual feedback voltage is larger than a threshold value, the power source decreases a voltage level of the first power voltage, and when the magnitude of the virtual feedback voltage is less than the threshold value, the power source increases the voltage level of the first power voltage.

14. The display device according to claim 12 , wherein the power source includes:
a sensor configured to sense a current value output to an output terminal of the power source based on an output of the error amplifier;
a power look-up table configured to store a resistance value between the output terminal of the power source and the display panel;
a power multiplier configured to multiply the current value and the resistance; and
a reference voltage source configured to adjust a magnitude of the reference voltage based on an output of the power multiplier.

15. The display device according to claim 3 , wherein the feedback part is disposed separately from the timing controller, the display panel, and the power source.

16. The display device according to claim 3 , wherein each of the controller and the virtual feedback voltage generator is integrated with at least one of the timing controller, the display panel, or the power source.

17. The display device according to claim 3 , wherein the controller includes:
a voltage drop amount calculator configured to calculate a voltage drop amount of the first power voltage generated between an output terminal of the power source and the display panel based on the image data;
a variation calculator configured to calculate a variation of the output signal from the generator circuit; and
an adder configured to generate the control signal based on a sum of the voltage drop amount and the variation.

18. The display device according to claim 17 , wherein the voltage drop amount calculator includes:
a first look-up table storing one or more current amounts associated with one or more image data, the one or more current amounts corresponding to current flowing from the output terminal of the power source to the display panel;
a second look-up table storing one or more resistance values for a resistance between the output terminal of the power source and the display panel, the resistance being configured to change based which subpixel among the plurality of subpixels is currently in a powered on state; and
a multiplier configured to calculate the voltage drop amount by multiplying an output from the first look-up table and an output from the second look-up table.

19. The display device according to claim 1 , wherein the feedback part includes:
a controller configured to generate a control signal based on the image data and the synchronization signal; and
a virtual feedback voltage generator configured to generate the virtual feedback signal based on the control signal,
wherein the virtual feedback voltage generator includes:
a digital analog convert

Assignees

• Lg Display Co Ltd

Inventors

• Park Dongwon
• Kwon Yongchul
• Kim Jungjae

Classifications

• G09G3/20 Primary

  for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} · CPC title

• G09G2320/0276

  for the purpose of adaptation to the characteristics of a display device, i.e. gamma correction · CPC title

• G09G2330/028

  Generation of voltages supplied to electrode drivers in a matrix display other than LCD · CPC title

• G09G3/006 Primary

  Electronic inspection or testing of displays and display drivers, e.g. of LED or LCD displays (testing individual LED's G01R31/2635; testing lamps G01R31/44; testing of optical features of LCD displays G02F1/1309) · CPC title

• G09G2360/16

  Calculation or use of calculated indices related to luminance levels in display data · CPC title