KR-20260064334-A - DISPLAY DEVICE

Abstract

A display device according to an embodiment of the present specification includes a display panel comprising a display area where pixels are arranged and a non-display area around the display area, a data driver that applies a data voltage to the pixels, and at least one gate driver that applies a scan signal and a light-emitting signal to the pixels, wherein the pixel comprises a light-emitting element including an anode electrode, a cathode electrode, and a light-emitting layer between the anode electrode and the cathode electrode, a driving transistor connected between a high-potential driving voltage line and a first node and having a gate electrode connected to a second node, a switching transistor connected between a data line and a second node and having a gate electrode that receives a first scan signal, a first initialization transistor connected between a reference voltage line and a second node and having a gate electrode that receives a second scan signal, a first light-emitting transistor connected between a high-potential driving voltage line and a driving transistor and having a gate electrode that receives a first light-emitting signal, a second light-emitting transistor connected between a first node and a light-emitting element and having a gate electrode that receives a second light-emitting signal, and a capacitor connected to a second node to control the driving transistor, wherein the driving transistor comprises an oxide semiconductor layer.

Inventors

• 안순성
• 김양완

Assignees

• 엘지디스플레이 주식회사

Dates

Publication Date

20260507

Application Date

20241031

Claims (20)

1. A display panel comprising a display area where pixels are arranged and a non-display area around the display area; A data driving unit that applies a data voltage to the pixels; and It includes at least one gate driver that applies a scan signal and a light emission signal to the pixels, and The above pixel is, A light-emitting element comprising an anode electrode, a cathode electrode, and a light-emitting layer between the anode electrode and the cathode electrode; A driving transistor connected between a high-potential driving voltage line and a first node, with its gate electrode connected to a second node; A switching transistor connected between a data line and the second node, wherein the gate electrode receives a first scan signal; A first initialization transistor connected between a reference voltage line and the second node, wherein the gate electrode receives a second scan signal; A first light-emitting transistor connected between the above-mentioned high-potential driving voltage line and the above-mentioned driving transistor, wherein the gate electrode receives a first light-emitting signal; A second light-emitting transistor connected between the first node and the light-emitting element, wherein the gate electrode receives a second light-emitting signal; and It includes a capacitor connected to the second node to control the driving transistor, A display device configured such that the above driving transistor includes an oxide semiconductor layer.
2. In Article 1, A display device in which the driving transistor, the switching transistor, the first initialization transistor, the first light-emitting transistor, and the second light-emitting transistor are all formed as N-type.
3. In Article 1, The above pixel is, A display device further comprising a second initialization transistor connected between the anode electrode and VARL of the light-emitting element, wherein the gate electrode receives a third scan signal.
4. A display device according to claim 1, wherein the capacitor comprises a first electrode, a second electrode and a third electrode, and at least one of the first to third electrodes is electrically connected to the source or drain electrode of the driving transistor.
5. In Article 4, A display device in which the first electrode is disposed on the same layer as the shielding metal, and the third electrode is disposed on the same layer as the gate electrode of the driving transistor.
6. In Article 4, The above capacitor is a display device comprising a storage capacitor and a compensation capacitor connected in series with each other.
7. In Article 6, A display device further comprising the above compensation capacitor configured in parallel with a second light-emitting transistor.
8. In Article 6, A display device in which the storage capacitor and the compensation capacitor are arranged with at least a portion overlapping.
9. In Article 6, A display device that operates such that a fixed DC voltage is applied to one end of the above-mentioned compensation capacitor, or that both ends are formed at the same potential.
10. In Article 1, The above pixel is, A display device comprising an initialization period in which a reference voltage is applied, a sampling period in which the driving transistor operates in a source follower manner, a programming period in which a data voltage is applied, and a light emission period in which a driving current is provided to a light-emitting element.
11. In Article 1, A display device in which the first light-emitting transistor is formed as a P-type.
12. In Article 11, A display device comprising a plurality of transistors formed by the same process as the first light-emitting transistor, wherein the gate driving unit is a gate driving unit.
13. In Article 1, A display device in which the gate driving unit is arranged to include a plurality of scan driving units and a plurality of light-emitting control driving units, respectively, in the non-display area on both sides of the display area.
14. In Article 13, A display device in which at least one of the plurality of scan driving units has one pixel row connected to one stage circuit, and the remaining scan driving units have two adjacent pixel rows connected to one stage circuit.
15. In Article 13, A display device in which at least one of the plurality of light-emitting control driving units applies the same first light-emitting signal or second light-emitting signal to two adjacent pixel rows.
16. In Article 1, A display device further comprising a low-potential driving voltage line formed to surround the outer edge of the display panel in the above-mentioned non-display area.
17. In Article 16, A display device in which the above low-potential driving voltage line is positioned outside the gate driving unit.
18. In Article 16, A display device further comprising a dam that overlaps at least a portion with the above-mentioned low-potential driving voltage line.
19. In Article 18, A display device further comprising a touch electrode connection line extending in overlap with the above dam.
20. In Article 19, A display device in which the above touch electrode connection line is formed with a double wiring structure.

Description

Display Device This specification is intended to improve the flicker performance and reliability of a display panel. Electroluminescence displays can be classified into inorganic and organic light-emitting displays depending on the material of the light-emitting layer. Active matrix type organic light-emitting displays include self-emissive Organic Light Emitting Diodes (OLEDs) and have the advantages of fast response speed, high luminous efficiency, brightness, and high viewing angles. In organic light-emitting displays, OLEDs are formed in each pixel. Organic light-emitting displays not only offer fast response speeds and excellent luminous efficiency, brightness, and viewing angles, but also superior contrast ratio and color reproduction because they can express black gradations as perfect black. The pixels of an organic light-emitting display device include a pixel circuit comprising a driving element for driving the OLED and a capacitor connected to the driving element. Due to process variations and device characteristic variations resulting from the manufacturing process of the display panel, there may be differences in the electrical characteristics of the driving elements among pixels. These differences can increase as the driving time of the pixels elapses. To compensate for variations in the electrical characteristics of the driving elements among pixels, an internal compensation circuit may be added to the pixel circuit. The internal compensation circuit samples the threshold voltage of the driving element and can compensate the gate voltage of the driving element by that threshold voltage. However, when pixels driven by the internal compensation circuit are driven at low brightness, brightness non-uniformity may occur within the screen of the display panel. FIG. 1 is a block diagram schematically illustrating a display device according to one embodiment of the present specification. FIG. 2 is a cross-sectional view showing a stacked form of a display device according to one embodiment of the present specification. FIG. 3 is a diagram showing the configuration of a gate driving unit in a display device according to an embodiment of the present specification. FIG. 4 is a drawing of a pixel circuit in a display device according to an embodiment of the present specification. Figure 5 is a driving timing diagram of the pixel circuit illustrated in Figure 4. FIGS. 6a to 6e are drawings showing the operation of the pixel circuit in detail during each driving period. FIGS. 7a and 7b are drawings of a pixel circuit and a driving timing diagram in a display device according to another embodiment of the present specification. The advantages and features of this specification and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, this specification is not limited to the embodiments below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of this specification is complete and to fully inform those skilled in the art of the scope of the disclosure, and this specification is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components. When one component is referred to as being "connected to" or "coupled to" another component, it includes cases where it is directly connected or coupled to the other component, or cases where another component is interposed. Conversely, when one component is referred to as being "directly connected to" or "directly coupled to" another component, it indicates that no other component is interposed. "And/or" includes each of the mentioned items and all combinations of one or more of them. The terms used herein are for describing embodiments and are not intended to limit the specification. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, "comprises" and/or "comprising" do not exclude the presence or addition of one or more other components, steps, actions, and/or elements to the mentioned components, steps, actions, and/or elements. Although terms such as first, second, etc. are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another. Therefore, it is obvious that the first component mentioned below may be the second component within the technical scope of this specification. Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning that is commonly understood by those skilled in the art to which this specification belongs. Furthermore, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defin