CN206541596U - A kind of OLED pixel drive circuit - Google Patents

Abstract

The utility model provides a kind of OLED pixel drive circuit, including the first transistor, second transistor, third transistor, the 4th transistor, the 5th transistor, the 6th transistor, driving transistor, the first storage capacitance, the second storage capacitance, Organic Light Emitting Diode, first voltage source, the second voltage source, initialization power supply, first node, Section Point, the 3rd node and fourth node；And it is provided with data signal input, reset signal end, signal scanning end, LED control signal end；The utility model increases the voltage of data signal, pixel domain space is reduced while reduction driving transistor power consumption, be conducive to making higher PPI pixel panels by the first storage capacitance of regulation and the capacitance size of the second storage capacitance.

Description

A kind of OLED pixel drive circuit

Technical field

The utility model is related to OLED display technology fields, and in particular to a kind of OLED pixel drive circuit.

Background technology

Relative to liquid crystal display device, Organic Light Emitting Diode (Organic Light Emitting Diode, OLED) Display device have the advantages that can self-luminous, contrast is high, reaction speed is fast, angle of visibility is wide.Under the conditions of existing process, to make The luminosity of Organic Light Emitting Diode (OLED) is limited in a certain prescribed limit, then data signal voltage Vdata is also immediately It has been limited to accordingly in a certain prescribed limit.But, the 7T1C as disclosed in CN101231821A patents in the prior art Image element circuit, its data signal voltage Vdata voltage range is smaller, causes to IC signal voltages required precision in circuit very Height, is unfavorable for later stage Gamma regulations, such as：When the brightness of the OLED is divided into 256 GTG, the corresponding Vdata of each GTG Difference is probably estimated as △ Vdata=(Max (Vdata)-Min (Vdata))/256, because △ Vdata are smaller, then to IC signals Voltage accuracy requires higher.In order to reach increase △ Vdata purpose, the method taken in the prior art is increase driving crystal The channel length of (DTFT) is managed, this method occupies larger image element circuit domain space, it is impossible to realize high PPI (Pixels Per Inch, represent the number of pixels that per inch is possessed), on the other hand also increase driving DTFT volumes during OLED is luminous Outer power consumption.

The content of the invention

For above-mentioned the deficiencies in the prior art, the utility model provides a kind of OLED pixel drive circuit, increases data The voltage range of signal voltage, reduce in circuit IC signal voltages precision will height.

In order to solve the above technical problems, the technical solution adopted in the utility model is：The utility model provides a kind of OLED Pixel-driving circuit, a kind of OLED pixel drive circuit, including the first transistor, second transistor, third transistor, the 4th crystalline substance Body pipe, the 5th transistor, the 6th transistor, driving transistor, the first storage capacitance, the second storage capacitance, organic light-emitting diodes Pipe, first voltage source, the second voltage source, initialization power supply, first node, Section Point, the 3rd node and fourth node；And It is provided with data signal input, reset signal end, signal scanning end, LED control signal end；

First source/drain of the first transistor connects the initialization power supply, and grid connects the reset signal End, the second source/drain connects the first node；

First source/drain of the second transistor connects the initialization power supply, and grid connects the reset signal End, the second source/drain connects the fourth node；

First source/drain of the third transistor connects the fourth node, and grid connects the signal scanning end, Second source/drain connects the Section Point；

First source/drain of the 4th transistor connects the 3rd node, and grid connects the signal scanning end, Second source/drain connects the data signal input；

First source/drain of the 5th transistor connects the 3rd node, and grid connects the light emitting control letter Number end, the second source/drain connects the first voltage source；

First source/drain of the 6th transistor connects the first node, and grid connects the light emitting control letter Number end, the second source/drain connects the Section Point；

First source/drain of the driving transistor connects the Section Point, and grid connects the fourth node, the Two source/drains connect the 3rd node；

The two ends of first storage capacitance connect first voltage source and the fourth node respectively；

The two ends of second storage capacitance connect the 3rd node and the fourth node respectively；

The positive pole of the Organic Light Emitting Diode connects the first node, negative pole connection the second voltage source.

Specifically, the voltage that the second voltage source is provided is more than the voltage that the initialization power supply is provided.

It should be noted that the first transistor, second transistor, third transistor, the 4th transistor, the 5th crystal The manufacture craft of pipe, the 6th transistor, the first source/drain of driving transistor and the second source/drain is identical, nominally may be used Exchange, it can nominally change according to the direction of voltage.

The beneficial effects of the utility model are：A kind of OLED pixel drive circuit that the utility model is provided, by adjusting Save the voltage range of the size increase data signal of the first storage capacitance and the second storage capacitance, on the one hand, reduce and IC is believed The required precision of number voltage, provides convenient to later stage Gamma regulations；On the other hand, due to the ditch of driving transistor need not be increased Road length, pixel domain space is reduced while realizing reduction driving transistor power consumption, is conducive to making higher PPI The pixel panel of (Pixels Per Inch represent the number of pixels that per inch is possessed).

Brief description of the drawings

Fig. 1 is a kind of structural representation for OLED pixel drive circuit that the utility model embodiment is provided；

Fig. 2 is a kind of driver' s timing schematic diagram of OLED pixel drive circuit in Fig. 1.

Embodiment

Below in conjunction with accompanying drawing, the technical solution of the utility model is clearly described, described embodiment is only Only it is a part of embodiment of the present utility model, rather than whole embodiments.

The utility model embodiment provides a kind of OLED pixel drive circuit, as shown in figure 1, a kind of OLED pixel driving electricity Road, including the first transistor T1, second transistor T2, third transistor T3, the 4th transistor T4, the 5th transistor T5, the 6th Transistor T6, driving transistor DTFT, the first storage capacitance C1, the second storage capacitance C2, Organic Light Emitting Diode D1, the first electricity Potential source VDD, the second voltage source VSS, initialization power supply Vinit, first node a, Section Point d, Section three node s and the 4th Point g；And it is provided with data signal input Vdata, reset signal end RESET, signal scanning end SCAN, LED control signal end EM；

First source/drain of the first transistor connects the initialization power supply Vinit, and grid connection is described to be resetted Signal end RESET, the second source/drain connects the first node a；

First source/drain of the second transistor connects the initialization power supply Vinit, and grid connection is described to be resetted Signal end RESET, the second source/drain connects the fourth node g；

First source/drain of the third transistor connects the fourth node g, and grid connects the signal scanning end SCAN, the second source/drain connects the Section Point d；

First source/drain of the 4th transistor connects the 3rd node s, and grid connects the signal scanning end SCAN, the second source/drain connects the data signal input Vdata；

First source/drain of the 5th transistor connects the 3rd node s, and grid connects the light emitting control letter Number end EM, the second source/drain connects the first voltage source VDD；

First source/drain of the 6th transistor connects the first node a, and grid connects the light emitting control letter Number end EM, the second source/drain connects the Section Point d；

First source/drain of the driving transistor connects the Section Point d, and grid connects the fourth node g, Second source/drain connects the 3rd node s；

The two ends of first storage capacitance connect first voltage source VDD and the fourth node g respectively；Described second deposits The two ends that storing up electricity is held connect the 3rd node s and fourth node g respectively；

The positive pole of the Organic Light Emitting Diode connects the first node a, negative pole connection the second voltage source VSS.

Specifically, the voltage that the second voltage source is provided is more than the voltage that the initialization power supply is provided.

As shown in Fig. 2 a kind of driver' s timing signal of the OLED pixel drive circuit provided for the utility model embodiment Figure, including reset signal end RESET, signal scanning end SCAN, LED control signal end EM waveform input signal figure.

The operation principle of the OLED pixel drive circuit of the present embodiment is described as follows：

Initial phase X1：Reset signal end RESET is low level, and signal scanning end SCAN is high level, light emitting control Signal end EM is high level, the first transistor T1 and second transistor T2 conductings, Organic Light Emitting Diode reverse bias, eliminates product Tired electric charge, meanwhile, fourth node g current potentials are discharged to Vinit；

Data write phase X2：Reset signal end RESET is high level, and signal scanning end SCAN is low level, and light control Signal end EM processed is high level, and third transistor T3 and the 4th transistor T4 are turned on, now the 3rd node s current potential Vs=Vdata, Driving transistor DTFT grids and the first source/drain short circuit, form diode structure, fourth node g current potentials Vg=Vdata- Vth, wherein Vth are driving transistor DTFT threshold voltage；

Glow phase X3：Reset signal end RESET is high level, and signal scanning end SCAN is high level, light emitting control letter Number end EM is low level, the 5th transistor T5 and the 6th transistor T6 conductings, now the 3rd node s current potential Vs=VDD, due to the One storage capacitance C1, the second storage capacitance C2 coupling effect, now fourth node g current potentialsBe consequently formed by first voltage source VDD via the 5th transistor T5, Driving transistor DTFT, the 6th transistor T6 and Organic Light Emitting Diode D1 to the second voltage source VSS current loop, You Jifa Optical diode now lights, and driving transistor DTFT is operated in saturation region, driving Organic Light Emitting Diode D1 electric current I_OLEDIt is full Foot：

Above formula is converted into the formula using Vdata as dependent variable:

Wherein, μ is the electron mobility of raceway groove, and Cox is the channel capacitance of driving tube unit area, and W is driving transistor DTFT channel widths, L is driving transistor DTFT channel lengths.

In the case where ensureing that μ, Cox technological level, W are in the same size, the storage of pixel-driving circuit is electric in the prior art Capacitance C is fixed value, and C=Cst can only increase Vdata models by increasing driving transistor DTFT channel lengths L size Enclose；Compared with prior art, the utility model is by setting the first storage capacitance C1 and the second storage capacitance C2, and causes C1+ C2=Cst, C1<Cst, (C1+C2)/C1>1, realization does not increase driving transistor DTFT channel length L, need to only pass through regulation the One storage capacitance C1 and the second storage capacitance C2 size can increase Vdata scope.

To sum up, the utility model is by setting the first storage capacitance C1 and the second storage capacitance C2 and being deposited by regulation first Storing up electricity holds C1 and the second storage capacitance C2 size, increases data signal Vdata voltage range, reduces to IC signals electricity The required precision of pressure, provides convenient to later stage Gamma regulations；And due to the channel length of driving transistor need not be increased, make Pixel domain space is reduced while obtaining driving transistor lower power consumption, is conducive to making higher PPI (Pixels Per Inch, represents the number of pixels that per inch is possessed) panel.

It should be noted that the utility model is on the basis of existing pixel-driving circuit, by the storage capacitance in circuit It is divided into two, realizes that data signal Vdata voltage ranges increase, in other pixel-driving circuits, such as 6T1C pixel driver Circuit, storage capacitance is divided into two or one point of technical scheme to realize the increase of data signal Vdata voltage ranges more, also should This is in the protection domain of this patent.

Such as above-mentioned embodiment is the utility model preferably embodiment, but embodiment of the present utility model is not by upper State the limitation of embodiment, it is other it is any without departing from Spirit Essence of the present utility model with made under principle change, modify, replace Generation, combination, simplification, should be equivalent substitute mode, are included within protection domain of the present utility model.

Claims (2)

1. a kind of OLED pixel drive circuit, it is characterised in that：Including the first transistor, second transistor, third transistor, Four transistors, the 5th transistor, the 6th transistor, driving transistor, the first storage capacitance, the second storage capacitance, organic light emission Diode, first voltage source, the second voltage source, initialization power supply, first node, Section Point, the 3rd node and Section four Point；And it is provided with data signal input, reset signal end, signal scanning end, LED control signal end；

First source/drain of the first transistor connects the initialization power supply, and grid connects the reset signal end, the Two source/drains connect the first node；

First source/drain of the second transistor connects the initialization power supply, and grid connects the reset signal end, the Two source/drains connect the fourth node；

First source/drain of the third transistor connects the fourth node, and grid connects the signal scanning end, second Source/drain connects the Section Point；

First source/drain of the 4th transistor connects the 3rd node, and grid connects the signal scanning end, second Source/drain connects the data signal input；

First source/drain of the 5th transistor connects the 3rd node, and grid connects the LED control signal end, Second source/drain connects the first voltage source；

First source/drain of the 6th transistor connects the first node, and grid connects the LED control signal end, Second source/drain connects the Section Point；

First source/drain of the driving transistor connects the Section Point, and grid connects the fourth node, the second source Pole/drain electrode connects the 3rd node；

The two ends of first storage capacitance connect first voltage source and the fourth node respectively；Second storage capacitance Two ends connect the 3rd node and the fourth node respectively；

The positive pole of the Organic Light Emitting Diode connects the first node, negative pole connection the second voltage source.

2. a kind of OLED pixel drive circuit as claimed in claim 1, it is characterised in that：The electricity that the second voltage source is provided Pressure is more than the voltage that the initialization power supply is provided.