KR-102964399-B1 - DISPLAY APPARATUS

KR102964399B1KR 102964399 B1KR102964399 B1KR 102964399B1KR-102964399-B1

Abstract

A display device according to an embodiment of the present specification includes a light-emitting element, a capacitor connected between a first node and a second node, a first electrode connected to a reference voltage supply line and a second electrode connected to the first node, a first transistor that supplies a reference voltage to the first node in response to a light-emitting control signal of the n-th pixel row, a second transistor that supplies a reference voltage to the second node in response to a first scan signal of the n-1-th pixel row and a first electrode connected to a reference voltage supply line and a second electrode connected to the second node, and a driving transistor that includes a first electrode to which a high potential driving voltage is applied and a second electrode connected to a third node, wherein the gate electrode is connected to the second node. Accordingly, the occurrence of a reference voltage short circuit in the pixel circuit of the light-emitting element can be improved to prevent image display failures of each pixel and improve reliability.

Inventors

김학수
정대성
이환주
백광현

Assignees

엘지디스플레이 주식회사

Dates

Publication Date: 20260512
Application Date: 20220630

Claims (15)

In a display device equipped with a plurality of pixels, Each of the above plurality of pixels is, Light-emitting element; A capacitor connected between the first node and the second node; A first transistor comprising a first electrode connected to a reference voltage supply line and a second electrode connected to the first node, and supplying a reference voltage to the first node in response to a light emission control signal of the n-th pixel row; A second transistor comprising a first electrode connected to the reference voltage supply line and a second electrode connected to the second node, and supplying the reference voltage to the second node in response to a first scan signal of the n-1th pixel row; A driving transistor comprising a gate electrode connected to the second node, a first electrode to which a high-potential driving voltage is applied, and a second electrode connected to a third node; A third transistor connected between the second node and the third node and connecting the gate electrode and the drain electrode of the driving transistor in a diode form in response to the second scan signal of the n-th pixel row; A fourth transistor that electrically connects the driving transistor to the light-emitting element in response to a light-emitting control signal of the n-1th pixel row; and A display device comprising a fifth transistor that initializes the light-emitting element in response to a second scan signal of the n-th pixel row.
In Article 1, The pixel circuit of the light-emitting element includes an initialization period, a sampling period, a holding period, and a light-emitting period, and A display device in which, during the initialization period, the light emission control signal of the n-th pixel row and the first scan signal of the (n-1)-th pixel row have at least a partially overlapping interval in which a low-level voltage is applied.
In Article 2, A display device in which the same potential is formed at both ends of the capacitor during the initialization period.
In Article 2, A display device in which the same reference voltage is supplied to the first node and the second node during the initialization period.
In Article 2, A display device in which a first reference voltage is supplied to the first node and a second reference voltage is supplied to the second node during the initialization period.
In Article 5, A display device in which the first reference voltage and the second reference voltage have the same or different voltage levels.
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In Article 1, A display device in which the first scan signal and the second scan signal have different pulse widths.
In Article 8, A display device in which the first scan signal has a pulse width smaller than the second scan signal.
In Article 1, The above third transistor is a display device comprising a plurality of sub-transistors.
In Article 1, A display device in which the first scan signal has a pulse width smaller than one horizontal period.
In Article 1, A display device in which the driving transistor and/or the second transistor comprises a plurality of sub-transistors.
In Article 1, A display panel having the above plurality of pixels arranged thereon; A gate driving unit and a data driving unit for driving the above display panel; and A display device further comprising a controller that controls the gate driving unit and the data driving unit.
In Article 13, The above-described display panel is a display device having at least a portion of one side recessed inward.
In Article 14, The above-described display panel is a display device having a shape in which at least a portion of one side is recessed inward by a first length from the outermost part.

Description

Display apparatus This specification relates to a display device, and more specifically, to a display device that improves the occurrence of a reference voltage short circuit in the pixel circuit structure of a light-emitting element formed in each pixel. Video display devices that display various information on a screen are a core technology of the information and communication era, and are evolving in a direction that makes them thinner, lighter, and more portable while also increasing performance. In particular, among image display devices, display devices are gaining increasing attention as color display means because they are not only advantageous in terms of power consumption due to low-voltage driving, but also offer high-speed response speed, high luminous efficiency, viewing angle, and contrast ratio. The display device implements an image through multiple pixels arranged in a matrix form. Each pixel is configured to include a light-emitting element, a switching transistor, a driving transistor, and a capacitor, etc., configured to independently drive the light-emitting element. The switching transistor of each pixel transmits the data voltage to the driving transistor and the capacitor, and the driving transistor is configured to control the current flowing to the light-emitting element. Accordingly, the brightness of each pixel was proportional to the current flowing to the light-emitting element, and the current flowing to the light-emitting element was determined by the gate-source differential voltage of the driving transistor and the threshold voltage of the driving transistor, etc. However, there was a problem in which brightness deviations occurred between pixels as the threshold voltage of the driving transistor gradually varied according to the driving time. Accordingly, a sampling pixel structure was conventionally proposed to compensate by sampling the threshold voltage of the driving transistor. In such sampling pixel structures, a short path may occur between the high-potential driving voltage and the reference voltage in some pixel circuits during the initialization period. In such cases, display defects such as horizontal stripe stains may occur on the display device. Therefore, measures are required to improve the display quality of the display device. FIG. 1 is a block diagram schematically showing a display device according to an embodiment of the present specification. FIG. 2 is a circuit diagram showing the configuration of a demultiplexer in a display device according to an embodiment of the present specification. FIG. 3 is a drawing of a stage of a gate driving unit included in a display device according to an embodiment of the present specification. FIG. 4 is a drawing of a pixel circuit of a display device according to an embodiment of the present specification. FIGS. 5a to 5d are drawings for explaining the driving period of the pixel circuit of FIG. 4. FIG. 6 is a drawing of a pixel circuit of a display device according to another embodiment of the present specification. FIG. 7 is a cross-sectional view showing the stacked form of a display device according to an 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 examples described below in detail together with the accompanying drawings. However, this specification is not limited to the examples disclosed below but may be implemented in various different forms. The examples of this specification 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 invention to which the invention of this specification belongs, and the invention of this specification is defined only by the scope of the claims. Shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for illustrating examples of this specification are exemplary and are not limited to the matters depicted in this specification. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing the examples of this specification, if it is determined that a detailed description of related prior art could unnecessarily obscure the essence of this specification, such detailed description is omitted. Other parts may be added unless the terms "includes," "has," "consists of," etc. mentioned in this specification are used. Where a component is expressed in the singular, it includes cases where it includes the plural unless specifically stated otherwise. In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement. In the case of a description of a positional relationship, for example, when the positional relationship between two parts is described using terms such as "on," "on top," "on bottom," or "next to," unless "immediately" or "directly"