This application claims the benefit of Korea Patent Application No. 10-2012-0155407 filed on Dec. 27, 2012, which is incorporated herein by reference for all purposes as if fully set forth herein.
Field of the Invention
Embodiments of the invention relate to an organic light emitting display and more particularly to a structure of power supply lines of an organic light emitting display.
Discussion of the Related Art
An active matrix organic light emitting display includes organic light emitting diodes (hereinafter, abbreviated to “OLEDs”) capable of emitting light by itself and has advantages of a fast response time, a high light emitting efficiency, a high luminance, a wide viewing angle, etc.
The OLED serving as a self-emitting element includes an anode electrode, a cathode electrode, and an organic compound layer formed between the anode electrode and the cathode electrode. The organic compound layer includes a hole injection layer, a hole transport layer, a light emitting layer, an electron transport layer, and an electron injection layer. When a driving voltage is applied to the anode electrode and the cathode electrode, holes passing through the hole transport layer and electrons passing through the electron transport layer move to the light emitting layer and form excitons. As a result, the light emitting layer generates visible light.
The organic light emitting display arranges pixels, each including the OLED in a matrix form, and represents a gray scale by controlling an amount of current flowing in the OLEDs. In the organic light emitting display, an amount of voltage change differs depending on an amount of current flowing in power supply lines of a display panel. The voltage change includes voltage drop and voltage rising. The power supply voltage is lower than an original input value by voltage drop, and is higher than the original input value by voltage rising.
The power supply lines include high potential cell driving voltage supply lines (hereinafter referred to as “ELVDD supply lines”) for supplying a high potential cell driving voltage ELVDD to a driving thin film transistor (TFT) of each pixel. If desired, the power supply lines may further include auxiliary power supply lines, such as initialization voltage supply lines (hereinafter referred to as “Vint supply lines”) for supplying an initialization voltage Vint to each pixel and reference voltage supply lines (hereinafter referred to as “Vref supply lines”) for supplying a reference voltage Vref to each pixel.
As shown in
As shown in
The Vint supply lines and the Vref supply lines may be disposed as shown in
As shown in
Further, when a short is generated between the auxiliary power supply lines and other lines at any position of the display panel, a high short current resulting from a voltage difference between the shorted lines and a low short resistance locally flows in the display panel. Hence, heat is generated in the short point of the display panel. As shown in
Embodiments of the invention provide an organic light emitting display capable of improving image quality and preventing a diffusion of burning by changing a disposition structure of power supply lines.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. These and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
In one aspect, there is an organic light emitting display comprising a plurality of pixels formed at crossings of data lines and gate line parts, and a main power supply line part configured to supply a cell driving voltage to the pixels, the main power supply line part including a plurality of main power supply lines extended along a first direction and main power supply line connection patterns for connecting the adjacent main power supply lines along a second direction substantially perpendicular to the first direction, wherein the main power supply line connection patterns are staggered along the second direction.
The main power supply line part includes an ELVDD supply line part configured to supply a high potential cell driving voltage ELVDD to the pixels and an ELVSS supply line part configured to supply a low potential cell driving voltage ELVSS to the pixels. The main power supply line connection patterns include ELVDD supply line connection patterns for connecting adjacent ELVDD supply lines along the second direction and ELVSS supply line connection patterns for connecting adjacent ELVSS supply lines along the second direction.
The number of ELVDD supply line connection patterns disposed between first and second ELVDD supply lines, which are positioned adjacent to each other in the second direction, is less than a vertical resolution of a display panel.
When the vertical resolution of the display panel is ‘1080’, the number of ELVDD supply line connection patterns disposed between the first and second ELVDD supply lines is about 5 to about 20.
The ELVDD supply line connection patterns are disposed between the first and second ELVDD supply lines at regular intervals along the first direction.
The ELVDD supply line connection patterns are disposed between the first and second ELVDD supply lines at irregular intervals along the second direction.
The organic light emitting display further comprises a Vint supply line part configured to supply an initialization voltage Vint to the pixels, the Vint supply line part including a plurality of Vint supply lines disposed along the first direction and Vint supply line connection patterns for connecting the adjacent Vint supply lines along the second direction, and a Vref supply line part configured to supply a reference voltage Vref to the pixels, the Vref supply line part including a plurality of Vref supply lines disposed along the first direction and Vref supply line connection patterns for connecting the adjacent Vref supply lines along the second direction. The Vint supply line connection patterns are staggered along the second direction, and the Vref supply line connection patterns are staggered along the second direction.
The number of Vint supply line connection patterns disposed between first and second Vint supply lines, which are positioned adjacent to each other in the second direction, is less than a vertical resolution of a display panel. The number of Vref supply line connection patterns disposed between first and second Vref supply lines, which are positioned adjacent to each other in the second direction, is less than the vertical resolution of the display panel.
When the vertical resolution of the display panel is ‘1080’, the number of Vint supply line connection patterns disposed between the first and second Vint supply lines is about 5 to about 20, and the number of Vref supply line connection patterns disposed between the first and second Vref supply lines is about 5 to about 20.
The Vint supply line connection patterns are disposed between the first and second Vint supply lines at regular intervals along the first direction, and the Vref supply line connection patterns are disposed between the first and second Vref supply lines at regular intervals along the first direction.
The Vint supply line connection patterns are disposed between the first and second Vint supply lines at irregular intervals along the first direction, and the Vref supply line connection patterns are disposed between the first and second Vref supply lines at irregular intervals along the first direction.
The first direction indicates a Y-axis direction in which the data lines extend, and the second direction indicates an X-axis direction in which the gate line parts extend.
Alternatively, the first direction indicates an X-axis direction in which the gate line parts extend, and the second direction indicates a Y-axis direction in which the data lines extend.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings:
Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
Exemplary embodiments of the invention are described below with reference to
As shown in
The display panel 10 includes the plurality of data lines 14, the plurality of gate line parts 15 crossing the data lines 14, and the plurality of pixels P respectively positioned at crossings of the data lines 14 and the gate line parts 15. Each gate line part 15 may include a scan line 15a, an emission line 15b and an initialization line 15c, depending on a structure of the pixel P. Each pixel P is connected to one data line 14 and the three signal lines 15a, 15b, and 15c constituting each gate line part 15. The pixels P receive a high potential cell driving voltage ELVDD, a low potential cell driving voltage ELVSS, a reference voltage Vref, and an initialization voltage Vint from a power source generator (not shown). For this, a main power supply line part for supplying the high potential cell driving voltage ELVDD and the low potential cell driving voltage ELVSS to the pixels P, a Vint supply line part for supplying the initialization voltage Vint to the pixels P, and a Vref supply line part for supplying the reference voltage Vref to the pixels P are formed in the display panel 10.
The main power supply line part is implemented in a semi-mesh structure so as to minimize an amount of voltage change and a diffusion of burning. The main power supply line part includes an ELVDD supply line part and an ELVSS supply line part. An auxiliary power supply line part including the Vint supply line part and the Vref supply line part is also implemented in a semi-mesh structure so as to minimize an amount of voltage change and a diffusion of burning.
The reference voltage Vref and the initialization voltage Vint may be set to be less than the low potential cell driving voltage ELVSS. The reference voltage Vref may be set to be greater than the initialization voltage Vint, and a difference between the reference voltage Vref and the initialization voltage Vint may be set to be greater than a threshold voltage of a driving thin film transistor (TFT) of each pixel P. Each pixel P may include an organic light emitting diode (OLED), a driving TFT, four switching TFTs, and two capacitors. For example, the pixel P may be designed to have the same structure as disclosed in detail in Korean Patent Application No. 10-2012-0095604 corresponding to the present applicant, which is hereby incorporated by reference in its entirety.
The timing controller 11 rearranges digital video data RGB received from the outside in conformity with a resolution of the display panel 10 and supplies the rearranged digital video data RGB to the data driving circuit 12. The timing controller 11 generates a data control signal DDC for controlling operation timing of the data driving circuit 12 and a gate control signal GDC for controlling operation timing of the gate driving circuit 13 based on timing signals, such as a vertical sync signal Vsync, a horizontal sync signal Hsync, a dot clock DCLK, and a data enable signal DE.
The data driving circuit 12 converts the digital video data RGB received from the timing controller 11 into an analog data voltage based on the data control signal DDC and supplies the data voltage to the data lines 14.
The gate driving circuit 13 generates a scan signal, an emission control signal, and an initialization signal based on the gate control signal GDC. The gate driving circuit 13 supplies the scan signal to the scan lines 15a in a line sequential manner, supplies the emission control signal to the emission lines 15b in the line sequential manner, and supplies the initialization signal to the initialization lines 15c in the line sequential manner. The gate driving circuit 13 may be directly formed in the display panel 10 in a GIP (Gate-driver In Panel) manner.
In the following description, the ELVDD supply line part will be described in detail as an exemplary structure of the main power supply line part. The structure of the ELVDD supply line part may be equally applied to the ELVSS supply line part. Thus, main power supply line connection patterns for connecting main power supply lines extending in a first direction may include ELVDD supply line connection patterns for connecting adjacent ELVDD supply lines along a second direction perpendicular to the first direction and ELVSS supply line connection patterns for connecting adjacent ELVSS supply lines along the second direction.
As shown in
One ELVDD supply line may be positioned in each pixel, or may be positioned in a number of pixels. For example, as shown in
The ELVDD supply line connection patterns may be disposed between the first and second ELVDD supply lines, which are adjacently positioned in the X-axis direction, at regular intervals or at irregular intervals along the Y-axis direction.
Alternatively, as shown in
The auxiliary power supply line part according to an embodiment of the invention includes the Vint supply line part and the Vref supply line part. Each of the Vint supply line part and the Vref supply line part is implemented in a semi-mesh structure so as to minimize an amount of voltage change and a diffusion of burning.
As shown in
One Vint supply line may be positioned in every at least two pixels. For example, as shown in
Alternatively, as shown in
As shown in
One Vref supply line may be positioned in every at least two pixels. For example, as shown in
Alternatively, as shown in
As described above, the embodiment of the invention configures the main power supply line part and/or the auxiliary power supply line part in a semi-mesh structure, thereby minimizing a reduction in image quality resulting from the voltage change and efficiently preventing or minimizing the diffusion of burning problem.
It will be apparent to those skilled in the art that various modifications and variation can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
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