CN100444225C - Organic light emitting display, and method for driving organic light emitting display and pixel circuit - Google Patents

Abstract

The present invention provides an organic light emitting display, and a method for driving an organic light emitting display and a pixel circuit capable of improving a uniformity of a luminance. In the organic light emitting display, a scan driver sequentially supplies a scan signal to a plurality of scan lines during each of a plurality of sub-frames included in one frame. A data driver applies a data voltage to a plurality of data lines during at least one light emitting sub-frame of the plurality of sub-frames included in the one frame, and applies a voltage corresponding to a black gradation to the plurality of data lines during at least one non-light emitting sub-frame of the plurality of sub-frames included in the one frame. A pixel portion displays an image according to the scan signal supplied to the plurality of scan lines and according to the data voltage and the voltage corresponding to the black gradation applied to the plurality of data lines.

Description

The method of organic light emitting display and driving organic light emitting display and image element circuit

The cross reference of related application

The application requires the korean patent application 10-2004-0094123 that submits to Korea S Department of Intellectual Property on November 17th, 2004 and 10-2004-0094124 number right of priority and rights and interests, and its full content comprises as a reference at this.

Technical field

The present invention relates to a kind of organic light emitting display and the method that is used to drive organic light emitting display and image element circuit, relate in particular to a kind of method that can improve the conforming organic light emitting display of brightness and be used to drive organic light emitting display and image element circuit.

Background technology

Recently, because the cathode ray tube (CRT) display is heavier and bigger, be used as substitute to CRT monitor so developed various flat-panel monitors.Described flat-panel monitor comprises LCD (LCD), field-emitter display (FED), plasma display panel (PDP) display and organic light emitting display etc.

In flat-panel monitor, organic light emitting display is to come luminous self-emission equipment by reconfiguring electronics and hole.Organic light emitting display can be called as organic electroluminescence display.Organic light emitting display has high response speed, compares with the slower response speed of the LCD that needs additional source of light, and the response speed of described organic light emitting display is more as the response speed of CRT monitor.

Organic light emitting display can be driven by passive matrix method or active matrix method.According to the passive matrix method, anode and negative electrode are formed intersect each other (or intersection), and select to want driven line.According to the active matrix method, the magnitude of current that flows through electroluminescent device (for example Organic Light Emitting Diode (OLED)) is controlled by active device.The main thin film transistor (TFT) (TFT hereinafter referred to as) that uses is as active device.Though the active matrix method is than passive matrix method complexity, it has the advantage that power consumption is little and launch time is long.

But when the threshold voltage of TFT was inconsistent, the organic light emitting display of active matrix type may not have consistent screen intensity.Particularly, when Organic Light Emitting Diode (OLED) is luminous continuously an image duration,, thereby further worsened the inconsistency of screen intensity because the influence that the error of threshold voltage causes accumulated.

Summary of the invention

Therefore, one embodiment of the present of invention method of providing a kind of conforming organic light emitting display that can improve brightness and driving organic light emitting display and image element circuit.

An alternative embodiment of the invention provides a kind of organic light emitting display and the driving method thereof that can adjust white balance.

In one embodiment of the present of invention, a kind of organic light emitting display is provided, comprising: scanner driver is used for providing sweep signal to arrive the multi-strip scanning line in proper order during each subframe of a plurality of subframes that are contained in a frame; Data driver, be used for during at least one luminous subframe of these a plurality of subframes that are contained in a described frame, applying data voltage, and be used for during at least one non-luminous subframe of these a plurality of subframes that are contained in a described frame, applying corresponding to the voltage of deceiving gray level to described many data lines to many data lines; And pixel portion, be used for coming display image according to the sweep signal that is provided to described multi-strip scanning line and according to the described data voltage that is applied to described many data lines with corresponding to the voltage of deceiving gray level.

According to another embodiment of the present invention, provide a kind of method that is used to drive organic light emitting display, described organic light emitting display comprises: scanner driver is used for providing sweep signal to the multi-strip scanning line; Data driver, be used for applying voltage to many data lines, and pixel portion, be used for according to offering the sweep signal of described multi-strip scanning line and coming display image according to the voltage that puts on described many data lines, described method: (a) during light period, sequentially provide sweep signal, and apply data voltage to described many data lines to described multi-strip scanning line; (b) during non-light period, sequentially provide sweep signal, and apply predetermined voltage to described many data lines to described multi-strip scanning line.In one embodiment, described predetermined voltage is the voltage corresponding to black gray level.

According to an embodiment more of the present invention, a kind of method of driving image element circuit image duration at one of being used for is provided, described image element circuit comprises: the first transistor is used for applying the voltage that will be applied in data line according to the sweep signal that is provided to sweep trace; Capacitor is used to store the voltage corresponding to the voltage that is applied; And transistor seconds, be used for applying corresponding to electric current in described capacitor stored voltage to Organic Light Emitting Diode.A described frame period comprises at least one luminous subframe and at least one non-luminous subframe.The described method that is used to drive image element circuit comprises during described at least one luminous subframe: when described sweep trace provides sweep signal, storage is corresponding to the voltage of the data voltage that will be applied in described data line; With the electric current that applies to described Organic Light Emitting Diode corresponding to stored voltage in described capacitor.The described method that is used to drive image element circuit comprises during described at least one non-luminous subframe: when described sweep trace provides sweep signal, storage will be applied in the voltage corresponding to black gray level of described data line; With the electric current that applies to described Organic Light Emitting Diode corresponding to stored voltage in described capacitor.

According to an embodiment more of the present invention, a kind of organic light emitting display is provided, comprising: pixel portion comprises: a plurality of red pixels that are connected to multi-strip scanning line and red data line; A plurality of green pixels that are connected to described multi-strip scanning line and green data line; With a plurality of blue pixel that are connected to described multi-strip scanning line and blue data line, and be used for showing an image an image duration; Scanner driver is used for providing sweep signal to described multi-strip scanning line in proper order during each subframe of a plurality of subframes that are contained in a described frame; And data driver, be used for during the emitting red light subframe of a plurality of subframes that are contained in a described frame, providing data-signal to described red data line, and provide corresponding to the signal of deceiving gray level to described red data line during the non-emitting red light subframe of a plurality of subframes in being contained in a described frame, be used for during the green emitting subframe of a plurality of subframes that are contained in a described frame, providing data-signal to described green data line, and provide corresponding to the signal of deceiving gray level to described green data line during the non-green emitting subframe of a plurality of subframes in being contained in a described frame, and be used for during the blue-light-emitting subframe of a plurality of subframes that are contained in a described frame, providing data-signal to described blue data line, and provide corresponding to the signal of deceiving gray level to described blue data line during the non-blue-light-emitting subframe of a plurality of subframes in being contained in a described frame, wherein said emitting red light subframe has the subframe of first quantity, described green emitting subframe has the subframe of second quantity, and described blue-light-emitting subframe has the subframe of the 3rd quantity, wherein, described first quantity, in described second quantity and described the 3rd quantity at least one is different with remaining quantity.

According to an embodiment more of the present invention, a kind of method that is used to drive organic light emitting display is provided, described organic light emitting display is used for showing an image duration image, described being used for comprises in the method that drive organic light emitting display an image duration: (a) sequentially provide sweep signal to the multi-strip scanning line, and apply first data voltage to the data line that is connected to red pixel, the data line that is connected to the data line of green pixel and is connected to blue pixel; (b) sequentially provide sweep signal to described multi-strip scanning line, and to the data line that is connected to described red pixel, be connected to the data line of described green pixel and at least a data line that is connected in the data line of blue pixel applies second data voltage, and apply predetermined voltage to remaining data line; (c) sequentially provide sweep signal, and apply described predetermined voltage to the data line that is connected to described red pixel, the data line that is connected to the data line of described green pixel and is connected to described blue pixel to described multi-strip scanning line.

Description of drawings

Drawing and description have illustrated illustration embodiment of the present invention together, and are used from explanation principle of the present invention with description one, wherein:

Fig. 1 is the figure that illustrates according to the organic light emitting display of first embodiment of the invention;

Fig. 2 is the figure that is illustrated in an example of the data driver that uses in the organic light emitting display shown in Fig. 1;

Fig. 3 is the circuit diagram that is illustrated in an example of the pixel of using in the organic light emitting display shown in Fig. 1;

Fig. 4 is used for the sequential chart that diagram is used to drive the method for the organic light emitting display shown in Fig. 1;

Fig. 5 is the figure that illustrates according to the organic light emitting display of second embodiment of the invention;

Fig. 6 is the figure that is illustrated in an example of the data driver that uses in the organic light emitting display shown in Fig. 5;

Fig. 7 is the circuit diagram that is illustrated in an example of the pixel of using in the organic light emitting display shown in Fig. 5; And

Fig. 8 is used for the sequential chart that diagram is used to drive the method for the organic light emitting display shown in Fig. 5.

Embodiment

In the detailed description below, illustrate and illustrated some illustration embodiment of the present invention by diagram.Those skilled in the art can understand, can all not break away under the situation of the spirit and scope of the present invention, revise described illustration embodiment in every way.Therefore, described accompanying drawing and explanation are counted as illustrative in itself, rather than determinate.May there be parts more illustrated in the accompanying drawings, perhaps unshowned in the accompanying drawings parts, this is because they for complete understanding the present invention not necessarily, are not therefore discussed to them in instructions.Identical Reference numeral is represented components identical.Here, when first element was connected to second element, a described element both can be directly connected to an element, also can be connected to second element indirectly by three element.

Fig. 1 is the figure that illustrates according to the organic light emitting display of first embodiment of the invention.With reference to Fig. 1, organic light emitting display comprises scanner driver 10, data driver 20, pixel portion 30 and timing controller 50.

Scanner driver 10 driven sweep line S1 to Sn.Scanner driver 10 produces sweep signal in response to scanner driver control signal SCS, and sequentially provides the sweep signal that is produced to sweep trace S1 to Sn.During each subframe, scanner driver 10 sequentially provides sweep signal to sweep trace S1 to Sn.

Data driver 20 driving data lines D1 to Dm.Data driver 20 is in response to data driver control signal DCS and video data Data and produce data voltage, and the data voltage that is produced is offered data line D1 to Dm.During the luminous period of sub-frame in the middle of a plurality of subframes that constitute a frame, data driver 20 provides data voltage to data line D1 to Dm, otherwise, during the non-luminous period of sub-frame in the middle of a plurality of subframes that constitute a frame, data driver 20 provides corresponding to the voltage of deceiving gray level to data line D1 to Dm.In one embodiment, data driver 20 is oneself to select data voltage and corresponding to the voltage of deceiving gray level, provide operation so that carry out above-mentioned voltage.In addition, in order to carry out aforesaid operations, the video data that data driver 20 receives corresponding to black gray level from timing controller 50.In the later case, timing controller 50 should apply video data corresponding to the video data that is input to timing controller 50 to data driver 20 during predetermined (or luminous) time cycle, and during the remaining time cycle, apply corresponding to the video data of deceiving gray level to data driver 20.

Pixel portion 30 comprises a plurality of pixels 40 that are connected to sweep trace S1 to Sn and data line D1 to Dm.And pixel portion 30 receives first source voltage VDD of first external voltage source and the second source voltage VSS of second external voltage source.Here, the first source voltage VDD and the second source voltage VSS are applied to each pixel 40.The image that each pixel 40 shows corresponding to the data-signal that offers it.

Timing controller 50 provides scanner driver control signal SCS to scanner driver 10, and provides data driver control signal DCS and video data Data to data driver 20.

Fig. 2 is the figure that is illustrated in an example of the data driver 20 that uses in the organic light emitting display shown in Fig. 1, is oneself to select data voltage and corresponding to the example under the voltage condition of black gray level at data driver 20 particularly.

With reference to Fig. 2, data driver 20 comprises shift register 21, data latches 22, D/A (D/A hereinafter referred to as) converter 23 and selector switch 24.Shift register 21 is in response to horizontal clock signal HCLK and horizontal-drive signal HSYNC and control data latch 22.Horizontal clock signal HCLK and horizontal-drive signal HSYNC are a kind of among the data driver control signal DCS of Fig. 1.Data latches 22 is receiving video data Data and the video data Data that receives outputed to D/A converter 23 concurrently sequentially.Data latches 22 is by controlling from the control signal of shift register 21 outputs.D/A converter 23 will convert aanalogvoltage to from the video data of data latches 22 parallel receives.Selector switch 24 outputs to data line D1 to Dm with the output voltage of D/A converter 23 during luminous period of sub-frame, and will be corresponding to the voltage V of black gray level during non-luminous period of sub-frame _BlackOutput to data line D1 to Dm.

Fig. 3 is the circuit diagram that is illustrated in an example of the pixel of using in the organic light emitting display shown in Fig. 1 40.Pixel 40 includes OLED OLED and image element circuit.Image element circuit comprises switching transistor M1, driving transistors M2 and capacitor Cst.Switching transistor M1 is applied to capacitor Cst according to the data voltage that the sweep signal that is provided to sweep trace Sn will put on data line Dm.Capacitor Cst stores the data voltage that is applied during the cycle of sweep signal is provided, and keeps the data voltage of being stored during the cycle that sweep signal is not provided.Driving transistors M2 will put on Organic Light Emitting Diode OLED corresponding to the electric current of the voltage of capacitor Cst.Organic Light Emitting Diode OLED is according to the galvanoluminescence that is applied.The first source voltage VDD is applied to the source electrode of driving transistors M2, and the second source voltage VSS is applied in Organic Light Emitting Diode OLED.

Fig. 4 is used for the sequential chart that diagram is used to drive the method for the organic light emitting display shown in Fig. 1.With reference to Fig. 1 and Fig. 4, a frame is made up of a plurality of subframes.More specifically, Fig. 4 frame is shown as by 4 subframe SF1, SF2, SF3 and SF4 and forms.During each period of sub-frame, sweep signal is sequentially offered sweep trace S1 to Sn.

The first subframe SF1 is luminous subframe.When the sweep signal of the first subframe SF1 is provided, data voltage V _Data1 to V _DataN is applied to data line Dm.Correspondingly, pixel portion 30 is sent the V that is applied corresponding to during the cycle of the first subframe SF1 _Data1 to V _DataThe light of n.

The luminous subframe of second to the 4th subframe SF2 to the SF4 right and wrong.When the sweep signal of second to the 4th subframe SF2 to SF4 is provided, corresponding to the voltage V of black gray level _BlackBe applied in data line Dm.Correspondingly, pixel portion 30 is according to the voltage V corresponding to black gray level that is applied during the cycle of second to the 4th subframe SF2 to SF4 _BlackShow image corresponding to black gray level.

Though in Fig. 4, the number of subframe is 4, the present invention is not thereby be limited to this.That is to say,, just can realize each side of the present invention as long as the number of subframe is 2 or bigger.And in Fig. 4, only the first subframe SF1 is luminous subframe, and remaining subframe SF2, SF3 and the luminous subframe of SF4 right and wrong.But, in a plurality of subframes, when at least one subframe is luminous subframe, and during the luminous subframe of at least one subframe right and wrong, just can obtain each side of the present invention.If at least two luminous subframes of subframe right and wrong, all luminous subframes that then are included in the frame can have the identical data voltage that will put on a pixel, or different data voltages.In Fig. 4, the length of four subframes is equal to each other.But, even when the length of the subframe that forms a frame differs from one another, also can realize each side of the present invention.In Fig. 4, luminous subframe is positioned at the previous section of a frame.But,, also can realize each side of the present invention even luminous subframe is positioned at the centre or the aft section of a frame.

Voltage corresponding to black gray level is voltage required when gray level is deceived in the pixel demonstration.But, owing in each pixel, threshold voltage V may occur _THError, so the voltage in a pixel corresponding to black gray level can be have than in another pixel of the threshold voltage of mistake, corresponding to the voltage of a grey gray level (being non-black gray level).An example corresponding to the voltage of deceiving gray level can be the first source voltage VDD.

Hereinafter, will the error delta V of the threshold voltage of traditional organic light emitting display be described _ThWith error delta V according to the threshold voltage of the organic light emitting display of first embodiment of the invention _ThCan how to influence the mean value of luminance errors, promptly flow through AME E (the Δ I of the electric current of Organic Light Emitting Diode _OLED).By following formula 1 express according to conventional cases, when the electric current that during a frame period, flows through Organic Light Emitting Diode OLED when luminous continuously:

$I_{\mathrm{<figure-callout\; id="1"\; label="OLED"\; filenames="C20051012544200201.png,C20051012544200221.png"\; state="\{\{state\}\}">OLED</figure-callout>}1}=I_D=\frac{\mathrm{\&beta;}}{2}{(V_{\mathrm{GS}1}-V_{\mathrm{TH}})}^2---\left(1\right)$

Wherein, I _OLED1Be the electric current that flows through traditional Organic Light Emitting Diode OLED, I _DBe the electric current that flows to its drain electrode from the source electrode of driving transistors, V _GS1Be the voltage between transistorized grid of conventional ADS driving and source electrode, V _ThBe the threshold voltage of driving transistors, and β is the gain factor of driving transistors.

Error delta V appears in the threshold voltage in traditional organic light emitting display _ThThe time, express error delta I by following formula 2 by the electric current of Organic Light Emitting Diode _OLED1:

${\mathrm{\&Delta;I}}_{\mathrm{<figure-callout\; id="1"\; label="OLED"\; filenames="C20051012544200201.png,C20051012544200221.png"\; state="\{\{state\}\}">OLED</figure-callout>}1}=\frac{\mathrm{\&beta;}}{2}{(V_{\mathrm{GS}1}-V_{\mathrm{TH}}+{\mathrm{\&Delta;V}}_{\mathrm{th}})}^2-\frac{\mathrm{\&beta;}}{2}{(V_{\mathrm{GS}1}-V_{\mathrm{TH}})}^2$

$=\frac{\mathrm{\&beta;}}{2}({2\mathrm{\&Delta;V}}_{\mathrm{th}}(V_{\mathrm{GS}1}-V_{\mathrm{TH}})+{V_{\mathrm{th}}}^2)---\left(2\right)$

In traditional organic light emitting display,, therefore flow through AME E (the Δ I of the electric current of Organic Light Emitting Diode owing to the electric current together of moving phase during all period of sub-frame of a frame _OLED) with flow through the error delta I of the electric current of Organic Light Emitting Diode _OLED1Identical.That is, can express AME E (the Δ I of the electric current that flows through Organic Light Emitting Diode by following formula 3 _OLED):

$E\left({\mathrm{\&Delta;I}}_{\mathrm{OLED}1}\right)=I_{\mathrm{<figure-callout\; id="1"\; label="OLED"\; filenames="C20051012544200201.png,C20051012544200221.png"\; state="\{\{state\}\}">OLED</figure-callout>}1}=\frac{\mathrm{\&beta;}}{2}(2{\mathrm{\&Delta;V}}_{\mathrm{th}}(V_{\mathrm{GS}1}-V_{\mathrm{TH}})+{{\mathrm{\&Delta;V}}_{\mathrm{th}}}^2)---\left(3\right)$

In organic light emitting display according to the present invention, when error delta V in threshold voltage, occurring _ThThe time, express the error delta I of the electric current that flows through Organic Light Emitting Diode by following formula 4 _OLED2:

${\mathrm{\&Delta;I}}_{\mathrm{<figure-callout\; id="2"\; label="OLED"\; filenames="C20051012544200201.png,C20051012544200221.png"\; state="\{\{state\}\}">OLED</figure-callout>}2}=\frac{\mathrm{\&beta;}}{2}{(V_{\mathrm{GS}2}-V_{\mathrm{TH}}+{\mathrm{\&Delta;V}}_{\mathrm{th}})}^2-\frac{\mathrm{\&beta;}}{2}{(V_{\mathrm{GS}2}-V_{\mathrm{TH}})}^2---\left(4\right)$

Wherein, V _GS2Be according to the grid of driving transistors M2 of the present invention and the voltage between the source electrode.

Suppose that a frame has a quantity N subframe, in a plurality of subframes only first subframe according to data voltage V _DataLuminous, remaining subframe shows the brightness of black gray level according to the voltage of the off status of organic light emitting display (off state) according to an embodiment of the invention, and this brightness is proportional with the electric current that flows through Organic Light Emitting Diode, then, if in first subframe, satisfy $V_{\mathrm{GS}2}-V_{\mathrm{TH}}=(V_{\mathrm{GS}1}-V_{\mathrm{TH}})\sqrt{N},$ Then the driving method according to first embodiment of the invention on average shows identical brightness with the conventional ADS driving method for a frame.Therefore, can express error delta I by following formula 5 _OLED2:

${\mathrm{\&Delta;I}}_{\mathrm{<figure-callout\; id="2"\; label="OLED"\; filenames="C20051012544200201.png,C20051012544200221.png"\; state="\{\{state\}\}">OLED</figure-callout>}2}=\frac{\mathrm{\&beta;}}{2}{((V_{\mathrm{GS}1}-V_{\mathrm{TH}})\sqrt{N}+{\mathrm{\&Delta;V}}_{\mathrm{th}})}^2-\frac{\mathrm{\&beta;}}{2}{\left((V_{\mathrm{GS}1}-V_{\mathrm{TH}})\sqrt{N}\right)}^2$

$=\frac{\mathrm{\&beta;}}{2}({2\mathrm{\&Delta;V}}_{\mathrm{th}}(V_{\mathrm{GS}1}-V_{\mathrm{TH}})\sqrt{N}+{\mathrm{\&Delta;V}}_{\mathrm{th}}^2)---\left(5\right)$

Because Organic Light Emitting Diode of the present invention is only luminous during cycle of first period of sub-frame in the cycle of all subframes of a frame, and during the cycle of remaining period of sub-frame, be closed (turn off), therefore, can express AME E (the Δ I of the electric current that flows through Organic Light Emitting Diode by following formula 6 _OLED2):

$E\left({\mathrm{\&Delta;I}}_{\mathrm{OLED}2}\right)=\frac{{\mathrm{\&Delta;I}}_{\mathrm{OLED}2}}{N}=\frac{\mathrm{\&beta;}}{2}(\frac{2\mathrm{\&Delta;}{V}_{\mathrm{th}}(V_{\mathrm{GS}1}-V_{\mathrm{TH}})\sqrt{N}}{N}+\frac{{{\mathrm{\&Delta;V}}_{\mathrm{th}}}^2}{N})---\left(6\right)$

As the AME E of the electric current of relatively expressing organic light emitting display of the present invention (Δ I _OLED2) formula 6 and express AME E (the Δ I of the electric current of traditional organic light emitting display _OLED2) formula 3 time, along with the quantity N of subframe increases, AME E (the Δ I of electric current _OLED2) significantly reduce.Therefore, organic light emitting display of the present invention has reduced the influence of the error of threshold voltage to brightness, thereby has improved the consistance of brightness.

In having the optional driving method of similar effect, be added to according to the oxide-semiconductor control transistors of led control signal operation between the Organic Light Emitting Diode OLED of the driving transistors M2 of Fig. 3 and Fig. 3.Whether this method control is provided to Organic Light Emitting Diode OLED according to being provided to the led control signal of oxide-semiconductor control transistors with electric current.That is, this optional driving method also is divided into light period and non-light period with a frame.But, in this driving method, because added the oxide-semiconductor control transistors of operating, so owing to the led control signal of additional oxide-semiconductor control transistors and additionally generation causes complicacy to improve according to led control signal.And, need the new scanner driver of design and need to increase the light emitting control line that is used for applying led control signal to pixel.Therefore, described optional method may reduce the aperture ratio of display.In contrast, in the organic light emitting display according to first embodiment of the invention, not needing increases the transistor of operating according to led control signal and is used to apply the light emitting control line of led control signal, and designs new scanner driver.The advantage of the first embodiment of the present invention is, can a frame be divided into light period and non-light period by using widely used scanner driver.

Fig. 5 is the figure that illustrates according to the organic light emitting display of second embodiment of the invention.With reference to Fig. 5, organic light emitting display comprises scanner driver 110, data driver 120, pixel portion 130 and timing controller 150.Described organic light emitting display on pixel portion 130 with a plurality of frame display images.A frame comprises a plurality of subframes.

Scanner driver 110 driven sweep line S1 to Sn.Scanner driver 110 produces sweep signal in response to scanner driver control signal SCS, and sequentially the sweep signal that is produced is offered sweep trace S1 to Sn.During each subframe, scanner driver 110 sequentially provides sweep signal to sweep trace S1 to Sn.

Data driver 120 driving data lines D1 (R), D1 (G), D1 (B) are to Dm (R), Dm (G), Dm (B).Data driver 120 is in response to data driver control signal DCS and video data Data and produce data voltage, and the data voltage that is produced is offered data line D1 (R), D1 (G), D1 (B) to Dm (R), Dm (G), Dm (B).During the luminous period of sub-frame in the middle of a plurality of subframes that constitute a frame, data driver 120 offers data line D1 (R), D1 (G), D1 (B) to Dm (R), Dm (G), Dm (B) with data voltage, otherwise, during the non-luminous period of sub-frame in the middle of a plurality of subframes that constitute a frame, data driver 120 will offer data line D1 (R), D1 (G), D1 (B) to Dm (R), Dm (G), Dm (B) corresponding to the voltage of black gray level.In one embodiment, data driver 120 is oneself to select data voltage and corresponding to the voltage of deceiving gray level, provide operation so that carry out above-mentioned voltage.In addition, in order to carry out aforesaid operations, the video data that data driver 120 receives corresponding to black gray level from timing controller 150.In the later case, timing controller 150 should apply video data corresponding to the video data that is input to timing controller 150 to data driver 120 during predetermined (or luminous) time cycle, and during the remaining time cycle, apply corresponding to the video data of deceiving gray level to data driver 120.

Pixel portion 130 comprises a plurality of pixels 140 that limited to Dm (R), Dm (G), Dm (B) by sweep trace S1 to Sn and data line D1 (R), D1 (G), D1 (B).And pixel portion 130 receives first source voltage VDD of first external voltage source and the second source voltage VSS of second external voltage source.Here, the first source voltage VDD and the second source voltage VSS are applied to each pixel 140.The image that each pixel 140 shows corresponding to the data-signal that offers it.

Timing controller 150 provides scanner driver control signal SCS to scanner driver 110, and provides data driver control signal DCS and video data Data to data driver 120.

Video data Data can have redness, green and blue video data.Described video data also has white video data.

On the other hand, though identical video data is offered the Organic Light Emitting Diode of organic light emitting display,, Organic Light Emitting Diode sends the light of different brightness according to material behavior.For example, the luminescence efficiency of green organic light emitting diode may be lower than the luminescence efficiency of organic blueness or red light emitting diodes.As mentioned above,, will not satisfy white balance, thereby cause and to show the image of undesirable color when the light time of in each Organic Light Emitting Diode, sending different efficient.Therefore, in organic light emitting display, after considering white balance, adjust the quantity of the luminous subframe in the middle of a plurality of subframes that form a frame according to organic red, green and blue LED according to the embodiment of the invention.In other words, in an embodiment of the present invention, be used to apply the quantity of data voltage and be set to maximal value, apply the quantity of data voltage and be set to less value to the data line D1 (R) of red pixel to the luminous subframe of Dm (R) and be used to apply the quantity and being used to of data voltage to the data line D1 (B) of blue pixel to the luminous subframe of Dm (B) to the data line D1 (G) of green pixel to the luminous subframe of Dm (G).Therefore, adjust the white balance of red pixel, green pixel and blue pixel to improve display quality.

Fig. 6 is the figure that is illustrated in an example of the data driver 120 that uses in the organic light emitting display shown in Fig. 5, particularly, is oneself to select data voltage and corresponding to an example under the voltage condition of black gray level at data driver 120.

With reference to Fig. 6, data driver 120 comprises shift register 121, data latches 122, D/A 123 and selector switch 124.Shift register 121 is in response to horizontal clock signal HCLK and horizontal-drive signal HSYNC and control data latch 122.Horizontal clock signal HCLK and horizontal-drive signal HSYNC are a kind of among the data driver control signal DCS of Fig. 5.Data latches 122 sequentially receives red video data R, green video data G and blue video data B, and the redness that will receive, green and blue video data R, G and B output to D/A converter 123 concurrently.Data latches 122 is by controlling from the control signal of shift register 121 outputs.D/A converter 123 will convert aanalogvoltage to from the video data of data latches 122 parallel receives.Selector switch 124 outputs to data line D1 (R), D1 (G), D1 (B) to Dm (R), Dm (G), Dm (B) with the output voltage of D/A converter 123 during luminous period of sub-frame, and will be corresponding to the voltage V of black gray level during non-luminous period of sub-frame _BlackOutput to data line D1 (R), D1 (G), D1 (B) to Dm (R), Dm (G), Dm (B).In the embodiment of Fig. 6, after considering white balance, adjust the quantity of the luminous subframe in the middle of a plurality of subframes that form a frame according to organic red, green and blue LED.

Fig. 7 is the circuit diagram that is illustrated in an example of the pixel of using in the organic light emitting display shown in Fig. 5, have red pixel 140 (R), green pixel 140 (G) and blue pixel 140 (B) 140.Red pixel 140 (R) comprises the organic red light emitting diodes OLED (R) and first image element circuit.Green pixel 140 (G) comprises the organic green LED OLED (G) and second image element circuit.Blue pixel 140 (B) comprises organic blue LED OLED (B) and the 3rd image element circuit.Each of first, second and the 3rd image element circuit comprises switching transistor M1 ', driving transistors M2 ' and capacitor Cst '.

Switching transistor M1 ' is applied to capacitor Cst ' according to the data voltage that the sweep signal that is provided to sweep trace Sn will put on data line Dm.Capacitor Cst ' stores the data voltage that is applied during the cycle of sweep signal is provided, and keeps the data voltage of being stored during the cycle that sweep signal is not provided.Driving transistors M2 ' will put on its corresponding Organic Light Emitting Diode OLED (R), OLED (G) or OLED (B) corresponding to the electric current of the voltage of capacitor Cst '.Corresponding Organic Light Emitting Diode OLED (R), OLED (G) or OLED (B) are according to the galvanoluminescence that is applied.The first source voltage VDD is applied to the source electrode of driving transistors M2 ', and the second source voltage VSS is applied in corresponding Organic Light Emitting Diode OLED (R), OLED (G) or OLED (B).

Fig. 8 is used for the sequential chart that diagram is used to drive the method for the organic light emitting display shown in Fig. 5.Because the luminescence efficiency of green organic light emitting diode OLED (G) is minimum among Organic Light Emitting Diode OLED (R), OLED (G) and the OLED (B), so the sequential chart of Fig. 8 is by making the longer example adjusting the situation of white balance of light period of green organic light emitting diode OLED (G).

With reference to Fig. 5 and Fig. 8, a frame is made up of a plurality of subframes.More specifically, Fig. 8 frame is shown as by 4 subframe SF1, SF2, SF3 and SF4 and forms.During each period of sub-frame, sweep signal is sequentially offered sweep trace S1 to Sn.

In the situation that applies the red data line Dm (R) of data voltage to red pixel, the first subframe SF1 serves as luminous subframe.When the sweep signal of the first subframe SF1 is provided to red pixel, data voltage V _Data1 (R) is to V _DataN (R) is applied to red data line Dm (R).Therefore, the red pixel that is connected to red data line Dm (R) sends the data voltage V that is applied corresponding to during the described first subframe SF1 _Data1 (R) is to V _DataThe light of n (R).Second to the 4th subframe SF2 to SF4 serves as non-luminous subframe.When the sweep signal of second to the 4th subframe SF2 to SF4 is provided, corresponding to the voltage V of black gray level _Black(R) be applied to red data line Dm (R).Similarly, the red pixel that is connected with red data line Dm (R) according to during second to the 4th subframe SF2 to SF4, apply, corresponding to the voltage V of black gray level _Black(R) show corresponding to the image of deceiving gray level.

In the situation that applies the green data line Dm (G) of data voltage to green pixel, the first and second subframe SF1 to SF2 serve as luminous subframe.When the sweep signal of the first and second subframe SF1 to SF2 was provided to the green pixel that is connected to green data line Dm (G), green pixel sent corresponding to the data voltage V that is applied to green data line Dm (G) _Data1 (G) is to V _DataThe light of n (G).The the 3rd to the 4th subframe SF3 to SF4 serves as non-luminous subframe.When the sweep signal of the third and fourth subframe SF3 to SF4 was provided to the green pixel that is connected to green data line Dm (G), green pixel was according to the voltage V corresponding to black gray level that is applied to green data line Dm (G) _Black(G) show corresponding to the image of deceiving gray level.

Applying data voltage in the situation of the blue data line Dm (B) of blue pixel, the first subframe SF1 serves as luminous subframe.When the sweep signal of the first subframe SF1 was provided to the blue pixel that is connected to blue data line Dm (B), blue pixel was sent corresponding to the data voltage V that is applied to blue data line Dm (B) _Data1 (B) is to V _DataThe light of n (B).Second to the 4th subframe SF2 to SF4 serves as non-luminous subframe.When the sweep signal of the second and the 4th subframe SF2 to SF4 is provided to the blue pixel that is connected to blue data line Dm (B), blue pixel according to be applied to blue data line Dm (B), corresponding to the voltage V of black gray level _Black(B) show corresponding to the image of deceiving gray level.

As mentioned above, by a frame being divided into a plurality of luminous subframes and a plurality of non-luminous subframe, and luminous subframe of separate operation and non-luminous subframe, can improve the consistance of brightness.The second embodiment of the present invention has increased the driving time of the green organic light emitting diode of the light with relatively low luminescence efficiency, thereby has adjusted white balance.

Though in Fig. 8, the number of subframe is 4, the present invention is not thereby be limited to this.That is to say,, just can realize each side of the present invention as long as the number of subframe is 2 or bigger.In Fig. 8, the length of four subframes is equal to each other.But, even when the length of the subframe that forms a frame differs from one another, also can realize each side of the present invention.And, in Fig. 8, though the quantity of luminous subframe of green data line Dm (G) and the different situation of quantity of the luminous subframe of red data line Dm (R) or blue data line Dm (B) are shown, and the situation that the quantity of the quantity of the luminous subframe of the quantity of the luminous subframe of green data line Dm (G), red data line Dm (R) and the luminous subframe of blue data line Dm (B) differs from one another is also contained within the scope of the present invention.In Fig. 8, luminous subframe is positioned at the previous section of a frame.But,, also can realize each side of the present invention even luminous subframe is positioned at the centre or the aft section of a frame.

Voltage corresponding to black gray level is voltage required when gray level is deceived in the pixel demonstration.But, owing in each pixel threshold voltage V may take place _THError, therefore, the voltage corresponding to black gray level in a pixel may be the voltage corresponding to a grey gray level that has than in another pixel of the threshold voltage of mistake.An example corresponding to the voltage of deceiving gray level can be the first source voltage VDD.Be applied to the voltage V of red data line Dm (R) corresponding to black gray level _Black(R), be applied to the voltage V of green data line Dm (G) corresponding to black gray level _Black(G) and be applied to the voltage V of blue data line Dm (B) corresponding to black gray level _Black(B) can be mutually the same or differ from one another.

Owing to according to the similar reason of the organic light emitting display of first embodiment of the invention, reduced of the influence of the error of threshold voltage according to the organic light emitting display of second embodiment of the invention, thereby improved the consistance of brightness brightness.Simultaneously, as mentioned above, the second embodiment of the present invention has increased the driving time of the Organic Light Emitting Diode of the light with relatively low luminescence efficiency, thereby has adjusted white balance.

Usually and as mentioned above, according to the organic light emitting display of the embodiment of the invention and the method that is used to drive organic light emitting display and image element circuit improved the brightness uniformity of organic light emitting display.The present invention also can be divided into light period and non-light period with a frame by using widely used scanner driver.And the present invention can adjust white balance.

Though invention has been described in conjunction with some example embodiment, but those skilled in the art are to be understood that, the invention is not restricted to the disclosed embodiments, but opposite, be intended to cover the various modifications within the spirit and scope that are included in claims and equivalent thereof.

Claims (16)

1, a kind of organic light emitting display comprises:

Scanner driver is used for providing sweep signal to arrive the multi-strip scanning line in proper order during each subframe of a plurality of subframes that are contained in a frame;

Data driver, be used for during at least one luminous subframe of these a plurality of subframes that are contained in a described frame, applying data voltage, and be used for during at least one non-luminous subframe of these a plurality of subframes that are contained in a described frame, applying corresponding to the voltage of deceiving gray level to described many data lines to many data lines; With

Pixel portion is used for coming display image according to the sweep signal that is provided to described multi-strip scanning line and according to the described data voltage that is applied to described many data lines with corresponding to the voltage of deceiving gray level,

Wherein said data driver comprises:

Shift register is used in response to clock signal and synchronizing signal and the output latch control signal;

Data latches is used for according to from the latch control signal of described shift register receiving video data sequentially, and is used for exporting concurrently described video data;

D/A is used for the output transform of described data latches is become aanalogvoltage, and is used to export described aanalogvoltage; With

Selector switch, be used at this during at least one luminous subframe to described data line output from the aanalogvoltage of described D/A output as data voltage, and be used at this during at least one non-luminous subframe to the voltage of described data line output corresponding to described black gray level.

2, organic light emitting display as claimed in claim 1, also comprise: timing controller, be used for applying the scanner driver control signal to described scanner driver, be used for applying the data driver control signal to described data driver, be used for during light period applying video data, and be used for during the remaining cycle applying video data corresponding to black gray level to described data driver corresponding to the video data that is received to described data driver.

3, organic light emitting display as claimed in claim 1, wherein, first source voltage of first voltage source and the second source voltage of second voltage source are applied in described pixel portion, and comprise the voltage of selecting corresponding to the voltage of described black gray level from the group of being made up of described first source voltage and the described second source voltage.

4, organic light emitting display as claimed in claim 1 wherein, is pixel in being included in a described pixel portion needed voltage when showing described black gray level corresponding to the voltage of described black gray level.

5, organic light emitting display as claimed in claim 1, wherein, each that is contained in these a plurality of subframes in the described frame all has the identical time cycle.

6, a kind of organic light emitting display comprises:

Pixel portion comprises: a plurality of red pixels that are connected to multi-strip scanning line and red data line; A plurality of green pixels that are connected to described multi-strip scanning line and green data line; With a plurality of blue pixel that are connected to described multi-strip scanning line and blue data line, and be used for showing an image an image duration;

Scanner driver is used for providing sweep signal to described multi-strip scanning line in proper order during each subframe of a plurality of subframes that are contained in a described frame; With

Data driver, be used for during the emitting red light subframe of a plurality of subframes that are contained in a described frame, providing data-signal to described red data line, and provide corresponding to the signal of deceiving gray level to described red data line during the non-emitting red light subframe of a plurality of subframes in being contained in a described frame, be used for during the green emitting subframe of a plurality of subframes that are contained in a described frame, providing data-signal to described green data line, and provide corresponding to the signal of deceiving gray level to described green data line during the non-green emitting subframe of a plurality of subframes in being contained in a described frame, and be used for during the blue-light-emitting subframe of a plurality of subframes that are contained in a described frame, providing data-signal to described blue data line, and provide corresponding to the signal of deceiving gray level to described blue data line during the non-blue-light-emitting subframe of a plurality of subframes in being contained in a described frame

Wherein said emitting red light subframe has the subframe of first quantity, and described green emitting subframe has the subframe of second quantity, and described blue-light-emitting subframe have the 3rd quantity subframe and

Wherein, at least one in described first quantity, described second quantity and described the 3rd quantity is different with remaining quantity.

7, organic light emitting display as claimed in claim 6, wherein said data driver comprises:

Shift register is used in response to clock signal and synchronizing signal and the output latch control signal;

Data latches is used for sequentially receiving redness, green and blue video data and being used for exporting concurrently described video data according to the latch control signal from described shift register;

D/A is used for the output transform of described data latches is become aanalogvoltage, and is used to export described aanalogvoltage; With

Selector switch is used to select to export from the aanalogvoltage of described D/A output with corresponding to the voltage of described black gray level.

8, organic light emitting display as claimed in claim 7, wherein said selector switch during described emitting red light subframe to the output of described red data line from the aanalogvoltage of described D/A output as data-signal, and during non-emitting red light subframe, export corresponding to the voltage of deceiving gray level as signal to described red data line corresponding to described black gray level

Wherein said selector switch during described green emitting subframe to the output of described green data line from the aanalogvoltage of described D/A output as data-signal, and during non-green emitting subframe, export corresponding to the voltage of deceiving gray level as signal to described green data line corresponding to described black gray level

Wherein said selector switch during described blue-light-emitting subframe to the output of described blue data line from the aanalogvoltage of described D/A output as data-signal, and during the non-blue-light-emitting subframe of described a plurality of subframes, export corresponding to the voltage of deceiving gray level as the signal corresponding to described black gray level to described blue data line.

9, organic light emitting display as claimed in claim 6, also comprise: timing controller, be used for applying the scanner driver control signal to described scanner driver, be used for applying the data driver control signal, and be used for sequentially applying video data sequentially applying corresponding to the video data of inputting video data with during non-light period during the light period corresponding to black gray level to data driver to data driver to described data driver.

10, organic light emitting display as claimed in claim 6, wherein, first source voltage of first voltage source and the second source voltage of second voltage source are applied in described pixel portion, and comprise the voltage of selecting corresponding to the voltage of described black gray level from the group of being made up of described first source voltage and the described second source voltage.

11, organic light emitting display as claimed in claim 6 wherein, is pixel in being included in a described pixel portion needed voltage when showing described black gray level corresponding to the voltage of described black gray level.

12, organic light emitting display as claimed in claim 6, wherein, each that is contained in a plurality of subframes in the described frame all has the identical time cycle.

13, organic light emitting display as claimed in claim 6, wherein, the pixel that has minimum luminescence efficiency in red pixel, green pixel and blue pixel is provided with the luminous subframe of the maximum quantity that comprises in a described frame.

14, a kind of method that is used to drive organic light emitting display, described organic light emitting display are used for showing an image an image duration that described method comprises:

(a) sequentially provide sweep signal, and apply first data voltage to the data line that is connected to red pixel, the data line that is connected to the data line of green pixel and is connected to blue pixel to the multi-strip scanning line;

(b) sequentially provide sweep signal to described multi-strip scanning line, and to the data line that is connected to described red pixel, be connected to the data line of described green pixel and at least a data line that is connected in the data line of blue pixel applies second data voltage, and apply predetermined voltage to remaining data line; With

(c) sequentially provide sweep signal, and apply described predetermined voltage to the data line that is connected to described red pixel, the data line that is connected to the data line of described green pixel and is connected to described blue pixel to described multi-strip scanning line.

15, method as claimed in claim 14, wherein said predetermined voltage are the voltage corresponding to black gray level.

16, method as claimed in claim 14, wherein, the luminescence efficiency of pixel that is connected to described at least one data line that is applied in second data voltage is lower than the luminescence efficiency of each pixel in the remaining pixel.

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