CN102074197A

CN102074197A - Driving method for active matrix organic light emitting display

Info

Publication number: CN102074197A
Application number: CN2011100232927A
Authority: CN
Inventors: 罗红磊; 邱勇; 高孝裕; 黄秀颀
Original assignee: Kunshan New Flat Panel Display Technology Center Co Ltd
Current assignee: Kunshan New Flat Panel Display Technology Center Co Ltd
Priority date: 2011-01-21
Filing date: 2011-01-21
Publication date: 2011-05-25
Anticipated expiration: 2031-01-21
Also published as: CN102074197B

Abstract

The invention provides a driving method for an active matrix organic light emitting display. Under the condition that N-type and P-type switch thin-film transistors coexist, the method controls vertical scanning initial signals and vertical scanning frequency generated by a time schedule controller by using a software algorithm in the time schedule controller, wherein for the N-type switch thin-film transistor, the vertical scanning initial signals are directly output from the time schedule controller by STVIN, namely when the EN signals are of low level; and for the P-type switch thin-film transistor, namely when the EN signals are of high level, the vertical scanning initial signals are required to be reversed.

Description

A kind of active matrix/organic light emitting display driving method

Technical field

The present invention relates to the driving method of a kind of active matrix/organic light emitting display (AMOLED), be particularly useful for N type in the chip for driving, P type switching thin-film transistor (TFT) and the situation of depositing under.

Background technology

Organic light emitting display (OLED) is the active illuminating device.Compare present main flow flat panel display Thin Film Transistor-LCD (TFT-LCD), OLED has advantages such as high-contrast, wide viewing angle, low-power consumption and volume are thinner.Therefore, OLED is expected to become the flat panel display of future generation after LCD, is one of the maximum technology that receives publicity in the present flat panel display.

In flat panel display, switching TFT commonly used is divided into N type and P type, and wherein N type switching TFT is the positive voltage conducting, and negative voltage is closed, and the P type is then on the contrary.Correspondingly, the gated sweep signal of conventional drive controlling chip is positive pulsewidth sweep type or negative pulsewidth sweep type.

At present, the grid driving circuit that part A MOLED producer directly continues to use LCD drives the AMOLED display, and wherein the driving circuit of most of LCD adopts positive pulsewidth sweep signal raster polar circuit, and promptly great majority are N type switching TFT.Therefore, if AMOLED producer just uses N-type semiconductor technology, then can directly use; And if AMOLED producer uses P-type semiconductor technology, then need the gated sweep signal is carried out reverse process.This will cause increasing circuit system cost and complexity.In addition, because the process conditions disunity, the cost that causes customizing grid circuit separately rises, and the chip development cycle is long, is unfavorable for determining of design proposal.

Therefore, in order to realize the shared of N type, P type switching TFT, and reduce the complexity of circuit design, the cost of development of saving custom chip is necessary the driving method of display is improved.

Summary of the invention

The present invention aims to provide a kind of active matrix/organic light emitting display driving method, and the situation that this method is used for N type, P type switching TFT and deposits has improved the matching of design of drive circuit, and has advantage simple in structure, that cost is low.

In one embodiment of the invention, provide a kind of active matrix/organic light emitting display driving method, be used for N type and P type switching thin-film transistor and the situation of depositing under, it utilizes the software algorithm in the time schedule controller

The vertical scanning start signal STV and the vertical scanning frequency of coming the control timing controller to produce, for N type switching thin-film transistor, described vertical scanning start signal is directly exported from time schedule controller by STVIN, when promptly the EN signal is low level; For P type switching thin-film transistor, when promptly the EN signal was high level, described vertical scanning start signal was carried out reverse process through the processing of following steps with STVIN:

With the positive pulsewidth of STVIN signal by 1/ (F*V _Total) expand to (V _Total-1)/(F*V _Total); And

Signal delay 1/ (the F*V that will in previous step, obtain _Total);

Wherein F is that the per second picture shows frame number, V _TotalBe the vertical scanning line number, obtain the vertical scanning start signal STV that P type switching TFT is used thus.

Preferably, described software algorithm is stored in the storage unit and combines with time schedule controller by embedded or plug-in mode.Described storage unit for example is EEPROM (electric erasable programmable memory device) or EPROM (erasable and programable memory), but is not limited to this.

Preferably, described method is used for the capable situation that drives (GOA) of array base palte.

In another embodiment of the present invention, a kind of active matrix/organic light emitting display driving method is provided, under the situation that is used for N type and P type switching thin-film transistor and deposits, wherein in time schedule controller, increase reverser and gauge tap, realize the shared property of driving of P type and two kinds of TFT of N type.When the EN signal was low level, the gated sweep signal was directly exported; When the EN signal was high level, the gated sweep signal is output after reverser is reverse.

Description of drawings

Fig. 1 is the synoptic diagram of the driving circuit of a kind of active matrix/organic light emitting display of the present invention.

Fig. 2 A is a kind of N type TFT dot structure equivalent circuit diagram of active matrix/organic light emitting display.

Fig. 2 B is a kind of P type TFT dot structure equivalent circuit diagram of active matrix/organic light emitting display.

Fig. 3 A is a N type TFT dot structure equivalent circuit diagram gated sweep waveform synoptic diagram.

Fig. 3 B is a P type TFT dot structure equivalent circuit diagram gated sweep waveform synoptic diagram.

Fig. 4 A is a vertical scanning start signal switching software algorithm synoptic diagram under the situation of P type and N type TFT according to an embodiment of the invention, and wherein this software algorithm is Wherein STV is the vertical scanning start signal, and STVIN represents the vertical scanning start signal imported, and EN is an enable signal.

Fig. 4 B is the block diagram of vertical scanning start signal reverse process under the situation of P type and N type TFT according to one embodiment of the present invention, in this step, utilizes following two conversion formulas, t _Enlarge=(V _Total-1)/(F*V _Total) and t _Delay=1/ (F*V _Total), realize the function of signals reverse.

Fig. 5 is according to another embodiment of the invention, and the hardware implementation mode in time schedule controller has wherein increased reverser and gauge tap in time schedule controller.

Fig. 6 A is that the signal that time schedule controller produces provides to the waveform synoptic diagram of N type switching TFT.

Fig. 6 B is that the signal that time schedule controller produces provides to the waveform synoptic diagram of P type switching TFT.

Embodiment

Preferably, the present invention is directed to the capable driving of array base palte (GOA---Gate on array, promptly directly gate driver circuit is produced on the array base palte) situation, STV signal and CKV, CPV signal through after handling, finish the reverse problem of gated sweep signal, realized chip for driving shared of P type and N type TFT.

Fig. 1 shows a kind of driving framework synoptic diagram of active matrix/organic light emitting display.Interface connector (Interface Connector) 102 out-put supply signals (VDD), data-signal and control signal.VDD is through DC-DC transducer 108, and on the one hand, step-down is that digital power signal (DVDD) is used for to data drive circuit (Source IC) 112, level translator (Level Shifter) 116 and time schedule controller (T/CON) 104 power supplies; On the other hand, boosting is analog power supply signal (AVDD), is used for to gamma circuit 110 and data drive circuit 112 power supplies.After data-signal and control signal enter T/CON, produce control timing, and data are sent to data drive circuit 112 by T/CON.Then, the vertical scanning start signal (STV) that provides of T/CON and line-scanning frequency signal (CPV) obtain vertical scanning start signal (STVP) and line-scanning frequency signal (CKV) after by level shifter 116.Then, GOA opens the switching TFT M2 of every row in response to STVP and CKV, referring to Fig. 2 A and 2B; The horizontal scanning start signal (STH) that data drive circuit 112 provides in response to T/CON, data download signal control signals such as (LOAD), the digital signal that receives from T/CON is converted into simulating signal, cooperate signals such as STVP and CKV that aanalogvoltage is loaded on the AMOLED, store in the capacitor C, and according to this potential value height, the conducting degree of control TFT M1 reaches control OLED brightness, the purpose that shows different GTGs is referring to Fig. 2 A and 2B.

Fig. 3 A is that N type TFT dot structure carries out the waveform synoptic diagram that gated sweep is finished 1 frame picture.As shown in Figure 3A, with the time n five equilibrium of 1 frame, each grid (G1, G2, G3 ..., Gn) correspondingly distribute a selected time (t1, t2, t3 ..., tn), thereby adopt the mode of lining by line scan to finish the driving of 1 frame.Particularly, during t1,, make the switch M2 conducting in this row N type TFT dot structure with positive pulsewidth sweep signal scanning controlling grid scan line G1, referring to Fig. 2 A, correspondingly the data-signal on the data line is to the conducting degree of charging of the capacitor C in this N type TFT dot structure and control TFT M1.During t2, controlling grid scan line G1 cuts off the power supply, and this line data signal is kept (keeping the time of 1 frame); Simultaneously, with positive pulsewidth sweep signal scanning controlling grid scan line G2.By that analogy, finish the driving of 1 frame.Similarly, Fig. 3 B is that P type TFT dot structure carries out the waveform synoptic diagram that gated sweep is finished 1 frame picture, and different with Fig. 3 A is, under the situation of P type TFT, scan controlling grid scan line (G1, G2, G3 with negative pulsewidth sweep signal, ..., Gn) make switch M2 conducting.

In embodiments of the invention, provide a kind of chip for driving of active matrix/organic light emitting display at P type and the shared driving method of N type TFT.

In embodiments of the invention, a kind of P type and N type switching TFT are provided and deposit the software algorithm that the vertical scanning start signal under the situation is changed,

Preferably, this software algorithm can be by the programmed control STV that is embedded in EEPROM, the waveform of CPV.Particularly, referring to Fig. 4 A, can be for the STV that N type switching TFT is used by STVIN directly from T/CON output, when promptly the EN signal is low level; STV for P type switching TFT is used when promptly the EN signal is high level, then needs through following steps STVIN to be carried out reverse process.

As non-restrictive example, will the driving method of realizing by this software algorithm (when the EN signal is high level) be described with the example that is shown as of 1024*768 resolution below, particularly referring to Fig. 4 B:

At first, utilize t _Enlarge=(V _Total-1)/(F*V _Total), V wherein _TotalBe the vertical scanning line number, F shows frame number for the per second picture, in this non-restrictive example, and V _TotalBe 806, F is 60, and the positive pulse of STVIN signal is expanded to (806-1)/(60*806) by 1/ (60*806);

Secondly, utilize t _Delay=1/ (F*V _Total), with the signal delay 1/ (60*806) that obtains after the expansion, realize the reverse of signal thus, can obtain the STV that P type switching TFT is used;

At this moment, STV=60HZ, CPV=70*806=48.363kHZ, the pulse width of G1, G2......Gn=1/ (48.363*1000)=20.6uS (under the perfect condition).

Preferably, described software algorithm is stored in the storage unit and combines with time schedule controller by embedded or plug-in mode.Described storage unit for example is EEPROM or EPROM, but is not limited to this.

In this non-restrictive example, described software algorithm is stored among the EEPROM and is embedded in the time schedule controller.

In another embodiment of the invention, provide a kind of hardware mode to realize P type and N type switching TFT and deposit driving method under the situation.In this embodiment, can be in inner reverser 120 and the gauge tap of increasing of T/CON, as shown in Figure 5.When the EN signal was low level, the gated sweep signal was directly exported; When the EN signal was high level, the gated sweep signal was oppositely exported the back through reverser 120, can realize the shared property of driving of P type and two kinds of TFT of N type thus.In addition, the annexation of T/CON and reverser is simple, can reduce the cost and the complexity of circuit system.

Should be understood that under the situation that does not depart from connotation of the present invention, any for improvement of the present invention, modification or modification, all be intended to be included within the protection domain of appending claims of the present invention.

Claims

1. active matrix/organic light emitting display driving method, be used for N type and P type switching thin-film transistor and the situation of depositing under, it utilizes the software algorithm in the time schedule controller

The vertical scanning start signal STV and the vertical scanning frequency of coming the control timing controller to produce, wherein

For N type switching thin-film transistor, described vertical scanning start signal is directly exported from time schedule controller by STVIN, when promptly the EN signal is low level;

For P type switching thin-film transistor, when promptly the EN signal was high level, described vertical scanning start signal was carried out reverse process through following steps to STVIN, comprising:

With the positive pulsewidth of STVIN signal by 1/ (F*V _Total) expansion (V _Total-1)/(F*V _Total);

Signal delay 1/ (the F*V that will in previous step, obtain _Total);

Wherein F is that the per second picture shows frame number, V _TotalBe the vertical scanning line number,

Obtain the vertical scanning start signal STV that P type switching thin-film transistor uses thus.

2. method according to claim 1, wherein said software algorithm are stored in the storage unit and combine with time schedule controller by embedded or plug-in mode.

3. method according to claim 2, wherein said storage unit are EEPROM or EPROM.

4. method according to claim 1, it is used for the situation of the capable driving of array base palte.