US-12626662-B2 - Display device and method for driving the same

US12626662B2US 12626662 B2US12626662 B2US 12626662B2US-12626662-B2

Abstract

A display device may include a display panel including at least one of a first sub-pixel, a second sub-pixel and a third sub-pixel, and a driver configured to control a light-emission operation of the at least one of the first to third sub-pixels. In addition, the driver may be configured to control the light-emission operation of the at least one of the first to third sub-pixels so that, in a first control mode, a pulse width is fixed and a data voltage value is varied such that the at least one sub-pixel emits light at a first luminance, and, in a second control mode, the data voltage value is fixed, and the pulse width is varied such that the at least one sub-pixel emits light at a second luminance.

Inventors

Jihoon HA

Assignees

LG DISPLAY CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20241209
Priority Date: 20221226

Claims (16)

1 . A display device comprising: a display panel including at least one of a first sub-pixel, a second sub-pixel and a third sub-pixel; and a driver configured to control a light-emission operation of the at least one of the first to third sub-pixels, wherein the driver is configured to control the light-emission operation of the at least one of the first to third sub-pixels so that: in a first control mode, a pulse width is fixed and a data voltage value is varied such that the at least one of the first to third sub-pixels emits light at a first luminance; and in a second control mode, the data voltage value is fixed, and the pulse width is varied such that the at least one of the first to third sub-pixels emits light at a second luminance, wherein one of the first to third sub-pixels is electrically connected to a common power line, and includes a light-emissive layer, a first electrode, and a second electrode, wherein a gate insulating layer is disposed on the common power line, wherein a drain electrode of a driving transistor is disposed on the gate insulating layer, and wherein the first electrode of the one of the first to third sub-pixels is electrically connected to the drain electrode of the driving transistor via a pixel electrode, and the second electrode of the one of the first to third sub-pixels is electrically connected to the common power line via a common electrode.
2 . The display device of claim 1 , wherein in the first control mode, the driver is configured to fix the pulse width to a first specific value, set a current value of the at least one of the first to third sub-pixels to be in a range of about 30 to 60 milliampere (mA), and set the data voltage value of the at least one of the first to third sub-pixels to be in a range of about 1 to 2 volts (V).
3 . The display device of claim 1 , wherein in the second control mode, the driver is configured to fix the data voltage value and a current value of the at least one of the first to third sub-pixels respectively to second and third specific values, and set the pulse width to be in a range of about 10 to 1,000 microseconds (μs).
4 . The display device of claim 1 , wherein each of the first to third sub-pixels includes a micro-LED chip.
5 . The display device of claim 4 , wherein the driver is embodied as a micro driver configured to control light-emission operation of the micro-LED chip of the at least one of the first to third sub-pixels.
6 . The display device of claim 1 , wherein each of the first to third sub-pixels includes an organic light-emitting diode (OLED).
7 . The display device of claim 1 , wherein the first to third sub-pixels are configured to emit light of different colors, respectively.
8 . The display device of claim 7 , wherein a sub-pixel selected from among the first sub-pixel, the second sub-pixel, and the third sub-pixel is configured to emit light of one of red, blue, and green colors.
9 . The display device of claim 1 , wherein each of the first to third sub-pixels is electrically connected to a driving circuit for driving light-emission of each sub-pixel.
10 . The display device of claim 9 , wherein the driving circuit includes: a light-emission transistor connected to each sub-pixel and configured to be turned on for the pulse width set in the second control mode; and a driving transistor connected to and disposed between the light-emission transistor and a data voltage line, wherein the driving transistor is configured to switch application of the data voltage value set in the first control mode to each sub-pixel.
11 . The display device of claim 10 , wherein the driver is configured to: upon receiving a light-emitting control command from a timing controller, turn on the driving transistor so that the data voltage value set in the first control mode is applied to the each sub-pixel; and turn on the light-emission transistor so that the light-emission transistor is switched in the pulse width set in the second control mode.
12 . The display device of claim 10 , wherein a plurality of power lines, a plurality of scan lines, a reference voltage line, the data voltage line, and a light-emitting control line are disposed in the driving circuit.
13 . The display device of claim 1 , wherein the driver is configured to: when an image signal is applied thereto, generate a coordinate value of each sub-pixel to emit light among the first to third sub-pixels; and apply the data voltage value set in the first control mode to each sub-pixel corresponding to the generated coordinate value for the pulse width set in the second control mode.
14 . The display device of claim 1 , wherein the first control mode is a high luminance operation of the at least one of the first to third sub-pixels.
15 . The display device of claim 14 , wherein the second control mode is a low luminance operation mode of the at least one of the first to third sub-pixels.
16 . A display device comprising: a display panel including at least one of a first sub-pixel, a second sub-pixel and a third sub-pixel; and a driver configured to control a light-emission operation of the at least one of the first to third sub-pixels, wherein the driver is configured to control the light-emission operation of the at least one of the first to third sub-pixels so that a data voltage value set in a first control mode is applied to the at least one of the first to third sub-pixels for a pulse width set in a second control mode, wherein a luminance of each of the first to third sub-pixels is set by varying the pulse width, wherein at least one sub-pixel among the first to third sub-pixels includes: an active layer; a first semiconductor layer provided on the active layer; a second semiconductor layer; a first electrode electrically connected to the first semiconductor layer; and a second electrode, wherein the active layer and the second electrode are provided on the second semiconductor layer, wherein one of the first to third sub-pixels is electrically connected to a common power line, wherein a gate insulating layer is disposed on the common power line, wherein a drain electrode of a driving transistor is disposed on the gate insulating layer, and wherein the first electrode of the one of the first to third sub-pixels is electrically connected to the drain electrode of the driving transistor via a pixel electrode, and the second electrode of the one of the first to third sub-pixels is electrically connected to the common power line via a common electrode.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a Continuation of U.S. application Ser. No. 18/238,812, filed on Aug. 28, 2023, which claims priority to Korean Patent Application No. 10-2022-0184188 filed on Dec. 26, 2022 in the Republic of Korea, the entire contents of all these applications being hereby expressly incorporated by reference into the present application. BACKGROUND Field The present disclosure relates to a display device using a light-emitting element and a method for driving the same. Discussion of Related Art A display device with a self-light-emitting element can be implemented to be thinner than a display device with a built-in light source, and has the advantage of being able to implement a flexible and foldable display device. Such a display device having the self-light-emitting element can include an organic light-emitting display device using a light-emissive layer made of an organic material, and a micro-LED display device using a micro light-emitting diode (LED). However, while the organic light-emitting display device does not require a separate light source, a defective pixel can easily occur due to moisture and oxygen. Thus, various technical ideas are additionally used to minimize penetration of oxygen and moisture. In response to this demand, research and development on a display device using a micro light-emitting diode as a light-emitting element has been conducted. Such a light-emitting display device has high image quality and high reliability and thus is in the limelight as the next-generation display device. The micro light-emitting element is a semiconductor light-emitting element that uses property of emitting light when current flows through a semiconductor, and is widely used in a lighting apparatus, TV, and various display devices. Further, as a current level of the micro light-emitting element is higher, the external quantum efficiency (EQE) has a normal value, and light-emitting efficiency is improved. However, when a micro light-emitting element is used in a small display device using a relatively low current, the micro light-emitting element can have a lowered EQE. SUMMARY OF THE DISCLOSURE Accordingly, in order to solve or address the above-mentioned and other disadvantages and limitations associated with the related art, the inventor of the present disclosure has invented an improved display device capable of driving a micro-LED element such that the external quantum efficiency (EQE) is not lowered even when the micro light-emitting element is used in a small display device. Therefore, a technical purpose to be achieved by the present disclosure is to provide a display device and a method for driving the same in which when a micro-LED element is used in a small display device, the micro-LED element operates in a low luminance operation mode and a high luminance operation mode, and in the low luminance operation mode, a data voltage is fixed and a pulse width is varied to set the luminance, and in the high luminance operation mode, the pulse width is fixed and the data voltage is varied to set the luminance. Purposes according to the present disclosure are not limited to the above-mentioned purpose. Other purposes and advantages according to the present disclosure that are not mentioned can be understood based on following descriptions, and can be more clearly understood based on embodiments according to the present disclosure. Further, it will be easily understood that the purposes and advantages according to the present disclosure can be realized using means shown in the claims or combinations thereof. A display device according to one embodiment of the present disclosure can include a display panel including at least one of a first sub-pixel, a second sub-pixel and a third sub-pixel; and a driver configured to control light-emission operation of the at least one of the first to third sub-pixels, wherein the driver is configured to control the light-emission operation of the at least one of the first to third sub-pixels such that a data voltage value set in a first control mode is applied to the at least one sub-pixel for a pulse width set in a second control mode. A method for driving a display device according one embodiment of the present disclosure is provided, wherein the display device can include a display panel including at least one of a first sub-pixel, a second sub-pixel, a third sub-pixel and a fourth sub-pixel; a light-emission transistor connected to each of the first to fourth sub-pixels; a driving transistor connected to the light-emission transistor; and a driver configured to control light-emission operation of the at least one sub-pixel, wherein the method can include receiving a light-emitting control signal in response to application of an image signal from a timing controller; turning on the driving transistor; switching the driving transistor so that a data voltage set in a first control mode is applied to the at least one su