CN202150459U

CN202150459U - AMOLED display

Info

Publication number: CN202150459U
Application number: CN201120298418U
Authority: CN
Inventors: 张林涛
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2011-08-16
Filing date: 2011-08-16
Publication date: 2012-02-22
Anticipated expiration: 2021-08-16

Abstract

The utility model discloses an AMOLED (Active Matrix Organic Light Emitting Diode) display and relates to the technical field of OLED (Organic Light Emitting Diode) displayer. The display includes a TFT (Thin Film Transistor) array substrate and a DC/DC converter electrically connecting with each pixel on the TFT array substrate through a power bus. The display also includes at least one first flexible circuit board arranged on the periphery of the TFT array substrate and electrically connected to the DC/DC converter. The first flexible circuit board connects with the power bus electrically. In the utility model, by adding the flexible circuit board, a power lead in a position having voltage drop in a far end of the DC/DC converter is connected to the DC/DC converter directly through the power bus. Thus, the voltage drop caused by the overlong power lead when the power voltage is transmitted on the TFT array substrate is reduced, and the uniformity of the AMOLED display is improved substantially. And the AMOLED display has a simple structure and comparatively low cost.

Description

Active matrix organic light emitting diode display

Technical field

The utility model includes OLED, and (Organic Light-Emitting Diode, OLED) display technology field relates in particular to a kind of active matrix organic light emitting diode display.

Background technology

The OLED technology is the electronic display technology of future generation that takes the lead, and is described as " dreamlike display ".According to the difference of picture element array structure, the OLED display is divided into passive matrix OLED (PMOLED) display and active matrix OLED (AMOLED) display.The AMOLED display has thin thickness, in light weight, self-luminous, low driving voltage, high efficiency, high contrast, high color saturation, reaction speed is fast and characteristics such as bent, is the emerging Display Technique that is expected most.The AMOLED display device structure is at TFT (Thin Film Transistor; TFT) deposit or integrated OLED pixel on the array base palte; Form the OLED picture element matrix, the AMOLED display is a kind of current driving apparatus, and the OLED pixel will be luminous under electric excitation; The electric current that flows through the OLED pixel has determined the luminous intensity of OLED pixel; The thin film transistor array of active matrix display panel substrate is equivalent to switch arrays, and control flows is through the magnitude of current of each OLED pixel, and the size of the magnitude of current determines the brightness that the OLED pixel is showed.

As shown in Figure 1; The dot structure of traditional AMOLED display is the 2T1C structure; Promptly constitute by two TFT and an electric capacity; A TFT is for being responsible for starting and stopping the switching TFT of the discharge of storage capacitance, and another one TFT is provided as the drive TFT that pixel is set up the required voltage source of constant current.Flow through among the figure electric current I of OLED _ELFormula (1) below available calculates:

I _EL＝1/2*k(V _data-V _dd-V _th) ² (1)

Wherein, V _DataBe the input voltage of data wire, V _DdFor offering the supply voltage of OLED, V _ThBe the threshold voltage of drive TFT, k=W/L * C * u, W are the width of drive TFT raceway groove, and L is the length of drive TFT raceway groove, and C is the raceway groove of drive TFT and the electric capacity between the drive TFT grid, and u is the carrier mobility of drive TFT raceway groove.

In the AMOLED display, for all pixels provide V _DdPower supply lead wire all have power bus to link together, by the unified power supply of external voltage source.This be because all pixels to add required together electric current very big; Common drive IC can't provide, and can only be produced by outside DC-DC power supply (DC/DC), again through flexible PCB (Flexible Printed Circuit; FPC) be connected with panel, as shown in Figure 2.

The last DC/DC conversion chip of FPC produces V _DdSignal; Be hinged with (Flexible printed circuits board On Glass in the tft array substrate bottom through FPC and glass circuit board; FOG) introduce the tft array substrate left and right sides and form two power buss, introduce the inner power supply lead wire that connects each pixel of pixel by power bus again.Because the particularity of AMOLED current drives, this line has caused bigger problem: be illustrated in figure 3 as V on the tft array substrate _DdThe equivalent RC circuit diagram of bus, the V of the last generation of FPC _DdVoltage is transferred to the B point from the A point on tft array substrate, because the voltage drop that causes of power supply lead wire resistance makes voltage V _DdB is less than V _DdA.The V at C, D place in like manner _DdC and V _DdD is also variant, according to formula (1), and tft array substrate bottom and top; The electric current that flows through the OLED pixel is different; Along with the increasing of panel size, the power supply lead wire on the tft array substrate elongates gradually, and the resistance of its power supply lead wire is also obvious day by day accordingly; Thereby cause the inhomogeneous of demonstration, this phenomenon is called voltage drop (IR drop).

The method of existing compensating resistance pressure drop is generally increases compensation TFT, and such method has not only increased the complexity of AMOLED display device structure, simultaneously also owing to the reduction of producing yield has improved the display cost.

The utility model content

The technical problem that (one) will solve

The technical problem that the utility model will solve is: provide a kind of simple in structure, cost is lower and reduced the active matrix organic light emitting diode display of voltage drop phenomenon.

(2) technical scheme

For addressing the above problem; The utility model provides a kind of active matrix organic light emitting diode display; Comprise: tft array substrate and the DC/DC transducer that is electrically connected through each pixel on power bus and the said tft array substrate; This display also comprises: at least one first flexible PCB that is arranged on said tft array substrate edge and is electrically connected with said DC/DC transducer, said first flexible PCB is electrically connected with said power bus.

Preferably, said first flexible PCB is electrically connected with said power bus through at least one lead-in wire.

Preferably, said lead-in wire is made of copper.

Preferably, said DC/DC transducer is set in place on second flexible PCB of said tft array substrate one lateral edges.

Preferably, said DC/DC transducer is arranged on the printed circuit board (PCB), and said printed circuit board (PCB) is electrically connected with second flexible PCB that is arranged on said tft array substrate one lateral edges, and said second flexible PCB is electrically connected with said power bus.

Preferably, said first flexible PCB is arranged on the said tft array substrate edge of said second flexible PCB opposite side and/or adjacent both sides.

Preferably, said first flexible PCB is electrically connected with said second flexible PCB.

Preferably, said first flexible PCB is electrically connected with said second flexible PCB through connector or welding pin.

(3) beneficial effect

The AMOLED display of the utility model; Through increasing flexible PCB the power supply lead wire that DC/DC transducer far-end can produce voltage drop phenomenon place directly is connected to the DC/DC transducer through power bus; When having reduced supply voltage and on tft array substrate, transmitting,, improved the uniformity of AMOLED display greatly by the voltage drop that long power supply lead wire causes; And simple in structure, cost is lower.

Description of drawings

Fig. 1 is the dot structure sketch map of the 2T1C of traditional AMOLED display;

Fig. 2 is traditional AMOLED display device structure sketch map;

Fig. 3 is the equivalent circuit diagram of the AMOLED display A point of Fig. 2 to the transmission of B point voltage;

Fig. 4 is the AMOLED display device structure sketch map of embodiment 1;

Fig. 5 is the AMOLED display end view of Fig. 4;

Fig. 6 is the equivalent circuit diagram of the AMOLED display A point of Fig. 4 to the transmission of B point voltage;

Fig. 7 is the AMOLED display device structure sketch map of embodiment 2;

Fig. 8 is the AMOLED display device structure sketch map of embodiment 3.

Embodiment

The AMOLED display that the utility model proposes specifies as follows in conjunction with accompanying drawing and embodiment.

The AMOLED display of the utility model; Comprise: the luminescent layer on tft array substrate and the tft array substrate; Luminescent layer comprises: deposit or be integrated in pel array, TFT, grid line, data wire, power bus on the tft array substrate and the drive IC that links to each other with grid line and data wire, this display comprise that also through power bus be the DC/DC transducer that each pixel of pel array provides supply voltage.In order to reduce the voltage drop that power supply lead wire causes; The AMOLED display of the utility model has increased at least one first flexible PCB that is electrically connected with the DC/DC transducer; The power supply lead wire that DC/DC transducer far-end can be produced voltage drop phenomenon place is connected to first flexible PCB through power bus, thereby reduces the voltage drop that long power supply lead wire causes.

Embodiment 1

As shown in Figure 4; The AMOLED display of present embodiment comprises: the pel array 2 on tft array substrate 1, the tft array substrate 1, drive IC 3, through power bus 5 and the DC/DC transducer 4 that is electrically connected with each pixel of pel array 2 through power bus 5 and the first flexible PCB 6-2.

DC/DC transducer 4 is set in place on the second flexible PCB 6-1 of tft array substrate 1 one lateral edges, for each pixel supply voltage V is provided through the power bus 5 that passes tft array substrate 1 _DdThe first flexible PCB 6-2 is arranged on the edge with the tft array substrate 1 of the second flexible PCB 6-1 opposite side; And be electrically connected with the second flexible PCB 6-1; Connected mode is preferably: the back side that the first flexible PCB 6-2 is folded into tft array substrate 1; It is electrically connected overleaf, as shown in Figure 5 through connector 7 or welding pin with the second flexible PCB 6-1.In fact, can adopt other electric connection mode, for example: the second flexible PCB 6-1 directly is electrically connected with the first flexible PCB 6-2 according to arts demand.

The first flexible PCB 6-2 is electrically connected with power bus 5 through at least one lead-in wire, thereby introduces supply voltage V simultaneously from the relative both sides of tft array substrate 1 _Dd, lead-in wire selects the mode of many parallel connections can further reduce lead resistance.The resistance of considering copper is very little, and this lead-in wire can be preferably made of copper.

Be illustrated in figure 6 as the equivalent schematic of the display A point of present embodiment to the transmission of B point voltage, because the resistance of copper lead-in wire is very little, the V on lead-in wire _DdVoltage drop can be ignored, the V that introduce simultaneously the relative both sides of the tft array substrate 1 at the second flexible PCB 6-1 and first flexible PCB 6-2 place _DdCan regard approximately equal as, V is promptly arranged _DdA=V _DdB=V _DdC=V _DdDWith respect to the display device structure shown in Fig. 2, lead resistance is to offering the V of each pixel _DdInfluence reduce greatly, thereby the uniformity of the display of present embodiment is increased dramatically.

The DC/DC transducer of the AMOLED display of present embodiment also can be made on the printed circuit board (PCB), then is electrically connected with power bus 5 through the second flexible PCB 6-1 and the first flexible PCB 6-2.

Embodiment 2

As shown in Figure 7; The difference of the AMOLED display of present embodiment and the AMOLED display of embodiment 1 is; The display of present embodiment comprises two first flexible PCB 6-2, and two first flexible PCB 6-2 are divided on tft array substrate 1 edge with the adjacent both sides of the second flexible PCB 6-1.

Embodiment 3

As shown in Figure 8; The difference of the AMOLED display of present embodiment and the AMOLED display of embodiment 1 is; The display of present embodiment comprises three first flexible PCB 6-2, and three first flexible PCB 6-2 are divided on the edge with the tft array substrate 1 of relative side of the second flexible PCB 6-1 and adjacent both sides.

Above execution mode only is used to explain the utility model; And be not the restriction to the utility model; The those of ordinary skill in relevant technologies field under the situation of spirit that does not break away from the utility model and scope, can also be made various variations and modification; Therefore all technical schemes that are equal to also belong to the category of the utility model, and the scope of patent protection of the utility model should be defined by the claims.

Claims

1. active matrix organic light emitting diode display; Comprise: tft array substrate and the DC/DC transducer that is electrically connected through each pixel on power bus and the said tft array substrate; It is characterized in that; This display also comprises: at least one first flexible PCB that is arranged on said tft array substrate edge and is electrically connected with said DC/DC transducer, said first flexible PCB is electrically connected with said power bus.

2. display as claimed in claim 1 is characterized in that, said first flexible PCB is electrically connected with said power bus through at least one lead-in wire.

3. display as claimed in claim 2 is characterized in that said lead-in wire is made of copper.

4. display as claimed in claim 2 is characterized in that, said DC/DC transducer is set in place on second flexible PCB of said tft array substrate one lateral edges.

5. display as claimed in claim 2; It is characterized in that; Said DC/DC transducer is arranged on the printed circuit board (PCB), and said printed circuit board (PCB) is electrically connected with second flexible PCB that is arranged on said tft array substrate one lateral edges, and said second flexible PCB is electrically connected with said power bus.

6. like claim 4 or 5 described displays, it is characterized in that said first flexible PCB is arranged on the said tft array substrate edge of said second flexible PCB opposite side and/or adjacent both sides.

7. display as claimed in claim 6 is characterized in that, said first flexible PCB is electrically connected with said second flexible PCB.

8. display as claimed in claim 7 is characterized in that, said first flexible PCB is electrically connected with said second flexible PCB through connector or welding pin.