CN100541579C - Image display device - Google Patents

Abstract

Disclose image display device, it comprises pixel array portion and peripheral circuit part.Described pixel array portion have follow to many sweep traces that extend, along row to many signal wires that extend and by matrix arrangement in described sweep trace and the cross one another locational a plurality of pixels of described signal wire.Described peripheral circuit partly has scanner and driver.Each pixel comprises sampling transistor, driving transistors, switching transistor and light-emitting component.

Description

Image display device

The cross reference of related application

The present invention includes the relevant theme of submitting in Jap.P. office with on November 17th, 2006 of Japanese patent application JP2006-310864, its full content is included in herein as a reference.

Technical field

The present invention relates to the active array type image display device, especially relate to such image display device, wherein light-emitting component is used for each pixel, and the light period in a field is controlled to regulate brightness.More specifically, the present invention relates to such image display device, wherein regulate when extracting (samplingout) or sparse (thining out) out and scan or appear at during similar operations the poor of light period between the different scanning line.

Background technology

To be used for the image display device of pixel be known and disclosed to light-emitting component therein, and for example U.S. Pat 6229506.

The conventional images display device consists essentially of pixel array portion that forms screen and the peripheral circuit part that drives pixel array portion.Pixel array portion comprise follow to the sweep trace that extends, along row to the signal wire that extends and by matrix arrangement in sweep trace and the cross one another locational pixel of signal wire.The peripheral circuit portion branch comprises scanner and driver, wherein scanner is used for providing the sequential control signal so that an enterprising line sequential scanning in field, sequential scanning provides picture signal to signal wire according to line and driver is used in predetermined transmission cycle to sweep trace.Each pixel comprises light-emitting component, is used for a plurality of transistors of driven light-emitting element or the like.At least control these transistors by first and second sweep traces.Sequential scanning comes sampling image signal so that light-emitting component is luminous to first sweep trace according to line.Simultaneously, the light period of second sweep trace control light-emitting component.

The scanner that is included in the peripheral circuit part comprises first scanner and second scanner at least, first scanner is used for providing first control signal of carrying out the picture signal sampling to first sweep trace, and second scanner is used for providing second control signal of carrying out light period control to second sweep trace.Two of first and second scanners all respond the common clock signal and move and transmit the different enabling pulses of supplying with them from the outside continuously, so that provide first and second control signals to the pixel array portion side respectively.

Summary of the invention

For image display device, with regard to the quantity of sweep trace, can use different standards.For example, the TSC-system formula is defined as 525 with sweep trace quantity, and pal mode is defined as 625 with sweep trace quantity.Here, if attempt on the image display device of TSC-system formula, to show the picture signal of pal mode, then, therefore need use to extract scanning (sampling outscanning) out because the line number of picture signal becomes greater than number of scanning lines.In extracting scanning out, first scanner that is used for continuous carries out image signal sampling (sampling), under common first transmission cycle and the second long transmission cycle mixes mutually than first transmission cycle situation, be provided for first control signal of controlling of sampling to first sweep trace in a field.At this moment, be that the unit is extracted the unwanted picture signal out with the sweep trace.

In extracting scanning out, the clock signal of definition transmission cycle need be provided to first scanner, wherein in these transmission cycles, common first transmission cycle mixes mutually with second transmission cycle longer than first transmission cycle.In the conventional images display device, the clock signal that waveform is identical with the waveform of the clock signal of supplying with first scanner is also supplied with second scanner, so that be used for second control signal of order light period control to the output of second sweep trace.Yet according to the method for describing just now, because the existence of the mixing of first and second transmission cycles, the time width of the light period of second control signal of definition supply second sweep trace changes for each scanning provisional capital.The variation of such time width makes and is difficult to regulate brightness, so that it all is uniformly for the every row on the whole screen, and the theme that Here it is will solve.

Therefore, need provide image display device,, also can regulate light period for each pixel column or line so that all be uniform even wherein when carry out extracting scanning or similar operations out.

According to embodiments of the invention, image display device is provided, the peripheral circuit part that it comprises pixel array portion and is configured to drive pixel array portion, wherein pixel array portion has many sweep traces that follow to extending, along being listed as to many signal wires that extend and pressing matrix arrangement in sweep trace and the cross one another locational a plurality of pixels of signal wire, and peripheral circuit partly has scanner and driver, scanner configurations becomes to provide the sequential scanning signal so that an enterprising line sequential scanning in field to sweep trace in predetermined transmission cycle, sequential scanning provides picture signal to signal wire to drive configuration one-tenth according to line, each pixel has sampling transistor, driving transistors, switching transistor and light-emitting component, first control signal that sampling transistor response provides from the first relevant sweep trace and conducting, so that the picture signal that sampling provides from one of relevant signal wire, the picture signal of driving transistors response sample transistor sampling, output current is supplied with light-emitting component, light-emitting component is based on the output current that provides from driving transistors, send the light that has according to the brightness of picture signal, switching transistor is arranged on the current path that output current flows through by this way: make response supply with from second sweep trace its second control signal time width and present on-state, thereby output current is supplied with light-emitting component, so that light-emitting component is luminous in light period according to this time width, scanner has first scanner and second scanner, first scanner configurations becomes to supply first control signal to first sweep trace, and second scanner configurations becomes to supply second control signal to second sweep trace, the clock signal of the first scanner response definition transmission cycle and moving, so that at first transmission cycle be blended in second transmission cycle in first transmission cycle first control signal is sequentially supplied with first sweep trace, defined transmission cycle comprises common first transmission cycle and long and mixing second transmission cycle within it than first transmission cycle, the response of second scanner moves with the clock signal clock signal synchronous of first scanner, so that second control signal is sequentially supplied with second sweep trace, wherein, because the mixing of first transmission cycle and second transmission cycle, the time width of second control signal of definition light period all changes for every row; Second scanner disconnects the output of second control signal according to second transmission cycle, regulates light period thereby contrast the variation that is caused by the mixing of second transmission cycle.

Preferably, for the time width of the difference that equals the second long transmission cycle of first transmission cycle and ratio first transmission cycle, second scanner is controlled to off-state with the output of second control signal.

Preferably, export to first sweep trace in the timing of timing of first control signal being different from first scanner, second scanner disconnects the output of second control signal of corresponding second sweep trace.

Preferably, second scanner is with response clock signal and second control signal that order produces and synchronously carry out logical and (AND) from the shielded signal of outside input with clock signal, so that the output of second control signal is controlled to off-state.

Image display device can be arranged such that pixel array portion has the sweep trace of predetermined quantity, and when driver according to the line sequential scanning to signal wire output quantity during greater than the picture signal of the first sweep trace quantity, first transmission cycle of first scanner in a field and be blended in second transmission cycle in first transmission cycle first control signal sequentially is provided, thus be that the unit is extracted the unwanted picture signal out with the sweep trace.

Preferably, the response of second scanner depends on that the light period of the second control signal time width changes the output break period, and in this output break period, the output of second control signal is controlled so as to off-state according to second transmission cycle.In this case, second scanner can be able to be controlled the output break period so that along with light period increases and reduces with changing.Particularly, image display device can be arranged such that second scanner can change the time width of second control signal, thereby in from the minimum light period in a field to the scope of maximum light period, can regulate light period with changing, and when control output break period was minimum light period with convenient light period, the output break period equaled the poor of first transmission cycle and second transmission cycle longer than first transmission cycle.In this case, second scanner can be controlled the output break period, and this output break period is zero when being maximum light period with convenient light period.Perhaps, when second scanner can be controlled the output break period with changing, second scanner can be fixed the starting point of output break period and change the length that the terminal point of exporting break period responds light period.

In image display device, the sampling (data write) of the first scanner control chart image signal, and the control of second scanner forms the fluorescent lifetime of the light-emitting component of each pixel.Here, between screen standard and picture signal standard, the quantity of sweep trace is different; Be used for control data and write the transmission cycle variation of first scanner regularly so that the received image signal in the sample line unit.If be used for second scanner differently operation that control data writes first scanner regularly and is used to control light period along with the common clock signal, then because they have fixed phase relation, the transmission cycle that is used to control second scanner of light period also is subjected to the influence of first scanner, so that transmission cycle changes, this has caused the light period difference between not collinear.Therefore, in image display device, when transmission cycle increases than its common length, apply shielded signal for second control signal that is used to control light period, so that disconnect the output of second control signal.Therefore, can make that light period is maintained fixed between each line, and the influence that not changed by transmission cycle.

In image display device, the output break period changes the light period that responds the time width that depends on second control signal, and in the output break period, second scanner is controlled to off-state according to second transmission cycle with second control signal.Particularly, second scanner can be controlled the output break period so that along with light period increases and reduces with changing.Here, can control the output break period in such a way with changing, can suppress the minimizing of screen intensity, and can reduce the influence of power supply load variations, eliminate the luminance difference between the line simultaneously basically with the response light period.

According to another embodiment of the present invention, image display device is provided, the peripheral circuit part that it comprises pixel array portion and is configured to drive pixel array portion, pixel array portion has many sweep traces that follow to extending, along being listed as to many signal wires that extend and pressing matrix arrangement in sweep trace and the cross one another locational a plurality of pixels of signal wire, peripheral circuit partly has scanner and driver, scanner configurations becomes to provide the sequential scanning signal so that an enterprising line sequential scanning in field to sweep trace in predetermined transmission cycle, sequential scanning provides picture signal to signal wire to drive configuration one-tenth according to line, and each pixel has sampling transistor, driving transistors, switching transistor and light-emitting component; First control signal that sampling transistor response provides from the first relevant sweep trace and conducting are so that the picture signal that sampling provides from one of relevant signal wire; The picture signal of driving transistors response sample transistor sampling is supplied with light-emitting component with output current; Light-emitting component sends the light that has according to the brightness of picture signal based on the output current that provides from driving transistors; Switching transistor is arranged on the current path that output current flows through by this way: make response supply with from second sweep trace its second control signal time width and present on-state, thereby output current is supplied with light-emitting component, so that light-emitting component is luminous in light period according to this time width; Scanner has first scanner and second scanner, and first scanner configurations becomes to supply first control signal to first sweep trace, and second scanner configurations becomes to supply second control signal to second sweep trace; The first scanner response definition comprise common first transmission cycle and than first transmission cycle long and mix second transmission cycle within it transmission cycle clock signal and move so that at first transmission cycle be blended in and in second transmission cycle in first transmission cycle first control signal sequentially supplied with first sweep trace; The second scanner response definition be different from first and second transmission cycles the 3rd transmission cycle the second clock signal and move, thereby second control signal that will have schedule time width is sequentially supplied with second sweep trace, so that the light period of row pixel is not subjected to the influence of the mixing of first and second transmission cycles.

Preferably, the second clock signal of the 3rd transmission cycle that second scanner is fixing with response definition and moving, sequentially supply with second sweep trace with second control signal that will have identical time width, so that the light period of row pixel is controlled, thus always identical and be not subjected to the influence of the mixing of first and second transmission cycles.

Preferably, second scanner is with the clock signal of response definition the 3rd transmission cycle and move, and wherein the 3rd transmission cycle equals the mean value of the mixed transmission cycle of first and second transmission cycles.

Preferably, each pixel also comprises correcting transistor, and it is configured to cooperate with switching transistor and carries out the correct operation of driving transistors in predetermined correction in the cycle; Except first scanner and second scanner, this scanner also comprises the 3rd scanner, it is configured to provide the 3rd control signal by three scan line to correcting transistor, and the response of the 3rd scanner is sequentially exported to three scan line with the clock signal of the second clock signal Synchronization of supplying with second scanner with the 3rd control signal.

Perhaps, image display device can be configured to like this, that is: each pixel also comprises correcting transistor, and it is configured to cooperate with switching transistor and carries out the correct operation of driving transistors in predetermined correction in the cycle; Except first scanner and second scanner, this scanner also comprises the 3rd scanner, it is configured to provide the 3rd control signal by three scan line to correcting transistor, and the response of the 3rd scanner is sequentially exported to three scan line with the first clock signal clock signal synchronous of supplying with second scanner with the 3rd control signal.

In addition, image display device can be configured to like this, that is: each pixel also comprises a correcting transistor, and it is configured to cooperate with switching transistor and sampling transistor and carries out the correct operation of driving transistors in predetermined correction in the cycle; Second scanner also comprises and is configured to respond the shift register that the second clock signal produces second control signal, be configured to respond the output that first clock signal produces another shift register of additional control signal and is configured to export to second sweep trace of row the additional control signal and the second control signal sum, except first scanner and second scanner, each pixel also comprises the 3rd scanner, it is configured to provide the 3rd control signal by three scan line to correcting transistor, and the response of the 3rd scanner is sequentially exported to three scan line with the first clock signal clock signal synchronous of supplying with first scanner with the 3rd control signal.

Image display device can be configured to like this, that is: pixel array portion has the sweep trace of predetermined quantity, and when driver according to the line sequential scanning to signal wire output quantity during greater than the picture signal of the first sweep trace quantity, first transmission cycle of first scanner in a field and be blended in second transmission cycle in first transmission cycle first control signal sequentially is provided, thus be that the unit is extracted the unwanted picture signal out with the sweep trace.

In image display device, first and second scanners are controlled so that synchronized with each other, thereby prevent that light period from changing.Particularly, when carrying out extraction scanning, provide first clock signal that defines transmission cycle to first scanner that is used for the sampling of control chart image signal, defined transmission cycle comprises common first transmission cycle and long and mixing second transmission cycle within it than first transmission cycle.Simultaneously, will with first clock signal synchronously and the second clock signal that defines the 3rd transmission cycle offer second scanner that is used to control light period, the 3rd transmission cycle equals the mean value of the transmission cycle that first and second transmission cycles mix therein.Therefore, second scanner can always provide second control signal to each second sweep trace in fixing transmission cycle, and is not subjected to the influence of the transmission cycle variation of the first scanner side.Therefore, image display device can show high-quality image according to the extraction mode.

According to description and the appended claims below in conjunction with accompanying drawing, above-mentioned and other features of the present invention and advantage will become apparent, and in the accompanying drawings, represent identical parts or element with identical Reference numeral.

Description of drawings

Fig. 1 is the block scheme that the universal architecture of image display device of the present invention is used in expression;

Fig. 2 is the circuit diagram of the example of the expression structure that is included in the pixel in the image display device shown in Fig. 1;

Fig. 3 is the oscillogram of the operation that can be carried out by the image display device shown in Fig. 1 of expression;

Fig. 4 is the sequential chart of the operation that can be carried out by the image display device shown in Fig. 1 of expression;

Fig. 5 is the synoptic diagram of the operation that can be carried out by the image display device shown in Fig. 1 of expression;

Fig. 6 is the sequential chart of the different operating that can be carried out by the image display device shown in Fig. 1 of expression;

Fig. 7 is the sequential chart of first operator scheme of the image display device shown in the presentation graphs 1;

Fig. 8 is shown in the presentation graphs 1, the circuit diagram of the structure example of second scanner of the image display device of the operation shown in can execution graph 7;

Fig. 9 is the sequential chart of second operator scheme of the image display device shown in the presentation graphs 1;

Figure 10 is the circuit diagram of the specific pixel structure example shown in the presentation graphs 2 respectively and the sequential chart of the described pixel operation of expression;

Figure 11 is the oscillogram of the operation of the pixel shown in expression Figure 10;

Figure 12 is the circuit diagram of another specific pixel structure example shown in the presentation graphs 2 respectively and the sequential chart of the described pixel operation of expression;

Figure 13 is the circuit diagram of the another specific pixel structure example shown in the presentation graphs 2 respectively and the sequential chart of the described pixel operation of expression;

Figure 14 is the oscillogram of the different operating of the pixel shown in expression Figure 13;

Figure 15 and 16 is circuit diagrams of different structure example of second scanner of the image display device shown in the presentation graphs 1;

Figure 17-the 19th, the sequential chart of the 3rd operator scheme of the image display device shown in the presentation graphs 1; And

Figure 20 is the sequential chart of the another operator scheme of the image display device shown in the presentation graphs 1.

Embodiment

At first with reference to figure 1, it illustrates the universal architecture of the image display device that the present invention is applied to.Shown in image display device consist essentially of pixel array portion 1 and be used to drive the peripheral circuit part of pixel array portion 1.Pixel array portion 1 comprise follow to the sweep trace VSCAN that extends, along row to the data line DATA that extends and by matrix arrangement in sweep trace VSCAN and the cross one another locational pixel 2 of data line DATA.In Fig. 1, each pixel 2 usefulness is added row number in the parenthesis of giving it and row and number is distinguished.The row of every corresponding sweep trace VSCAN number is illustrated in the parenthesis.Simultaneously, the peripheral circuit portion branch comprises scanner and level (H) driver 6, scanner is used for providing the sequential control signal so that an enterprising line sequential scanning in field, level (H) driver is used for providing picture signal (data) according to the line sequential scanning to data line DATA to sweep trace VSCAN in predetermined transmission cycle.

Each pixel 2 comprises sampling transistor, driving transistors, switching transistor and the light-emitting component such as organic EL (electroluminescence) element at least.First control signal that sampling transistor response provides from the first sweep trace VSCAN1 and conducting are so that the picture signal that sampling provides from relevant signal wire DATA.Driving transistors offers light-emitting component according to the picture signal of sampling with output current.Light-emitting component is based on the output current that offers it from driving transistors, and is luminous according to picture signal.Switching transistor is arranged on the current path that output current flows through, so that present on-state according to the time width of second control signal of supplying with it from the second sweep trace VSCAN2, thereby output current is supplied with light-emitting component, so that light-emitting component is luminous in light period according to light period.Can regulate screen intensity by regulating time width.

Scanner is divided into first scanner (Vscanner1) 3 and second scanner (Vscanner2) 4, first scanner 3 is used for supplying first control signal to the first sweep trace VSCAN1, and second scanner 4 is used for supplying second control signal to the second sweep trace VSCAN2.The clock signal (Vclock1) of first scanner, 3 response definition transmission cycles and moving, so that transmit the starting impulse (Vstart1) of supplying with it from the outside continuously, thereby will supply with the first sweep trace VSCAN1 (i) with order first control signal in the second transmission cycle T2 that is blended among the first transmission cycle T1 at the first transmission cycle T1, in defined transmission cycle, common first transmission cycle T1 and second transmission cycle longer than the first transmission cycle T1 mix in a field.Simultaneously, the response of second scanner 4 (Vscanner2) moves with the clock signal Vclock1 clock signal synchronous Vclock2 of first scanner 3, so that transmit another starting impulse (Vstart2) continuously, thereby order second control signal is supplied with the second sweep trace VSCAN2 (i).The waveform of second control signal is identical with the waveform of starting impulse (Vstart2), and the pulse width of starting impulse equals the time width of second control signal.Here, owing to second scanner 4 along with moving with first scanner, 3 clock signal synchronous, second scanner, 4 sides also are subjected to the influence of the mixing of the first transmission cycle T1 and the second transmission cycle T2, so that the time width of second control signal of definition light period all changes for each pixel column (line).In order to overcome this problem, second scanner 4 disconnects the output of second control signal according to the second transmission cycle T2, thereby regulates light period at the variation that is caused by the mixing of the second transmission cycle T2.

Preferably, second scanner 4 is controlled to the period that off-state reaches time width T2-T1 with the output of second control signal, and time width T2-T1 equals the first transmission cycle T1 and compares the poor of the second long transmission cycle T2 of the first transmission cycle T1.Preferably, be different from the timing of the timing of the corresponding first sweep trace VSCAN1 (i) output first control signal, second scanner 4 disconnects the output of second control signal of each second sweep trace VSCAN2 (i).In other words, except the timing of sampling image signal on line, second scanner 4 disconnects the output of second control signal.Therefore, prevented that the potential variation (potentialchange) that output by second control signal disconnects in the caused pel array from having a negative impact to the sampling operation of picture signal.Should be noted that second scanner 4 with response clock signal (Vclock2) and second control signal that produces continuously and carry out logical and (AND) from the shielded signal of outside input synchronously, so that disconnect the output of second control signal with clock signal.

Adopt aforesaid driving method, wherein image display device is carried out and is extracted scanning out.Pixel array portion 1 has the first sweep trace VSCAN1 of predetermined quantity.Here, when H driver 6 according to the line sequential scanning to data line DATA output quantity during greater than the picture signal of the first sweep trace VSCAN1 quantity, first scanner 3 provides the first transmission cycle T1 and is blended in order first control signal among the second transmission cycle T2 in the first transmission cycle T1 to the first sweep trace VSCAN1 in a field, thereby is that the unit is extracted the unwanted picture signal out with sweep trace VSCAN.

Simultaneously, according to another kind of form, second scanner 4 responds second clock signals (Vclock2) and moves so that the Vstart2 of transmission start pulse sequentially, thereby second control signal that will have schedule time width is supplied with the second sweep trace VSCAN2 (i), described second clock signal (Vclock2) is asynchronous with first clock signal (Vclock1) of supplying with first scanner 3, and definition is different from the 3rd transmission cycle of the first transmission cycle T1 and the second transmission cycle T2.Therefore, second scanner 4 can be controlled the light period of pixel 2 of each row, and is not subjected to the influence of the mixing of the first transmission cycle T1 of first scanner, 3 sides and the second transmission cycle T2.In this case, the clock signal Vclock2 of the 3rd transmission cycle that second scanner, 4 response definitions are fixing and moving sequentially supplies with the second sweep trace VSCAN2 (i) so that will have second control signal of identical time width.Therefore, the light period of row interior pixel 2 can be controlled so that be equal to each other, and be not subjected to the influence of the mixing of the first transmission cycle T1 and the second transmission cycle T2.Preferably, second scanner 4 is with the clock signal Vclock2 of response definition the 3rd transmission cycle and move, and the 3rd transmission cycle equals the mean value that the first transmission cycle T1 and the second transmission cycle T2 are included in the transmission cycle under the troubled water.Therefore, although first scanner 3 and 4 asynchronous operations of second scanner, they are the units synchronization operation with a field.

The circuit structure of each pixel 2 shown in Fig. 2 presentation graphs 1.With reference to figure 2, illustrated image element circuit comprises sampling transistor Tr1, driving transistors Tr3, switching transistor Tr2 and electrooptic cell at least, and described electrooptic cell can be organic EL luminous element OLED.Ordinary image signal is had sampling keeps the adjunct circuit 5 of function and/or calibration function to be inserted between sampling transistor Tr1 and the driving transistors Tr3.The circuit structure that should be noted that pixel 2 described herein is sometimes referred to as image element circuit.

In the circuit structure shown in Fig. 2, driving transistors Tr3 is a p channel transistor, and is connected to power lead VDD1 at its source electrode place, is connected to the anode of light-emitting component OLED by switching transistor Tr2 in its drain electrode place.Switching transistor Tr2 is connected to the second sweep trace VSCAN2 at its grid place.Simultaneously, sampling transistor Tr1 is connected to signal wire DATA at the one end, and is connected to the grid of driving transistors Tr3 by adjunct circuit 5 at its other end.Sampling transistor Tr1 is connected to the first sweep trace VSCAN1 at its grid place.

Sampling transistor Tr1 response is supplied with its first control signal and conducting so that sampling is supplied with its picture signal (data) from signal wire DATA, and remains on the picture signal (data) of sampling in the adjunct circuit 5 from the first sweep trace VSCAN1 (i).Driving transistors Tr3 offers light-emitting component OLED with the output current corresponding with sampling and the picture signal that keeps.Light-emitting component OLED is driven by the output current of supplying with it from driving transistors Tr3, so that send the light of certain brightness according to picture signal.Switching transistor Tr2 is arranged on the current path that output current flows through, and in the time width of second control signal of supplying with it from the second sweep trace VSCAN1 (i), present on-state, thereby output current is supplied with light-emitting component OLED, so that light-emitting component OLED is luminous in equaling the light period of described time width.

When the foundation raster scanning system is carried out the display operation of display device, always be not supplied in even clock with reference to the clock signal of V operation of scanner.One of situation about not providing by even clock is provided among Fig. 3.With reference to figure 3, in the illustrated case, the clock signal Vclock1 that supplies with first scanner has the one-period that equals two horizontal cycles, and a field comprises odd number horizontal cycle m.In this case, clock signal Vclock1 is nonreversible during conversion between the field.In other words, clock signal Vclock1 has the waveform that comprises common cycle and different cycles from hybrid mode.Between front court and back court, must carry out the operation of V scanner continuously.So far, clock signal Vclock1 must have high level when the top of back court.Therefore, in first horizontal cycle 1 of back court, carry out adjusting so that clock signal Vclock1 is nonreversible.

As another situation, can use wherein and on same display device, to show the having picture signal of varying number sweep trace, as the sweep trace of TSC-system formula and pal mode.Illustrate said circumstances among Fig. 4.Example is represented on the top of Fig. 4 sequential chart, and the display unit of sweep trace quantity that wherein is constructed with the TSC-system formula is based on identical TSC-system formula display image signals.In this case, H drive-side and V scanner side can with ordinary lines sequential scanning synchronous operation.Particularly, the H drive-side provides sequential picture signal (data) at each horizontal cycle.In Fig. 4, for every line, such data are all numbered.Simultaneously, V scanner side can respond common V clock signal and move, so that be provided for the control signal of sequential sampling to pixel array portion.Venable is the signal that is used to control the on/off of V scanner output stage, and in the example shown in Fig. 4, all Venable signals all are made as and pass through signal.

The lower illustration of Fig. 4 a kind of like this situation, the display device that wherein is designed to have the sweep trace quantity (525) of TSC-system formula is used for showing the picture signal of pal mode, the sweep trace quantity (625) that pal mode uses is greater than the sweep trace quantity of TSC-system formula.In this case, the V clock of V scanner side stops, and the Venable signal is applied in to the V scanner and extracts data out simultaneously.In the embodiment shown in Fig. 4, data on the 8th line and the data on the 14 line are drawn out of.When extracting out, it is longer than its normal length that the transmission cycle of V clock becomes.In addition, Venable signal activation when exporting the data of the 8th line, thus interrupt the output of sampling control signal.Therefore, although export the data of the 8th line from the H driver, they are not sampled by pel array, thereby are drawn out of.

The show state of Fig. 5 presentation video display device.The upper illustration of Fig. 5 a kind of like this show state, the image display device that wherein is used for the TSC-system formula shows the picture signal of TSC-system formula.In this case, the data 1,2,3 corresponding with each root line ... can be write continuously by top order.

The lower illustration of Fig. 5 another show state, wherein the image display device of TSC-system formula shows the picture signal of pal mode.In this case, the wire size of data side is greater than the wire size of device side.Therefore, carry out the extraction scanning of data.For example, although should normally write in the pixel of the 8th row according to the data of above-mentioned the 8th line, they are drawn out of, and are that the data of back the 9th row are write pixel.Similarly, although the data of the 14 line should write in the pixel of the tenth triplex row, they are drawn out of, and are that the tenth five-element's data are write pixel.By by this way, every 6-7 root line is extracted the data of single line out, can be presented at the PAL picture signal on the NTSC display device.

As another situation that can use this example, wherein showed in common 4: 3 and wide demonstration in 16: 9 between switchably identical received image signal to be presented at common length breadth ratio be on 4: 3 the display panel.Equally in this case, use the method that is similar to said method, by extracting the wide demonstration that sweep trace realizes that display image sweep trace quantity reduces out.

The operation of image display device shown in Fig. 6 presentation graphs 1 when using extraction scanning.Yet, should be noted that Fig. 6 represents the operation under such a case, wherein, do not give from second control signal of second scanner output and apply necessary shielding in order to illustrate and to describe conveniently.At first, at each horizontal cycle output data continuously from the H driver.Simultaneously, the clock signal Vclock1 and the Vclock2 that will be used to operate reference supplies with first and second scanners respectively.In illustrated example, use identical clock signal as clock signal Vclock1 and Vclock2.Yet according to the present invention, this does not need basically, but only needs clock signal Vclock1 and Vclock2 to have identical waveform, and they can have fixing differing.From Fig. 6, can find out, clock signal Vclock1 and Vclock2 are the clock signals of definition transmission cycle, and defined transmission cycle comprises common first transmission cycle T1 and the second transmission cycle T2 longer than the first transmission cycle T1 and that mix with the first transmission cycle T1 in a field.

First scanner (Vscanner1) moves so that sequentially export first control signal according to clock signal Vclock1.In the sequential chart of Fig. 6, export to first control signal of first sweep trace of first row and represent with Vscanner1 (1).First scanner moves in response to clock signal Vclock1, so that the first control signal Vscanner1 (1) is exported to first sweep trace of second row and back row by continuous show state.Similarly, second scanner moves in response to clock signal Vclock2 so that order second control signal is exported to second sweep trace.In the sequential chart of Fig. 6, export to second control signal of second sweep trace of first row and represent with Vscanner2 (1).Second control signal of the waveform that obtains by the translation second control signal Vscanner2 (1) is continuously supplied with the sweep trace of second row and back row individually.

In the sequential chart of Fig. 6, also sequentially illustrate the operational scenario of several pixel columns according to clock signal Vclock1 and Vclock2.Operational scenario (1) illustrates the mode of operation of first row (first line) pixel.At first, respond the sampling (writing) that the first control signal Vscanner1 (1) carries out data 1, then, respond the second control signal Vscanner2 (1), driven light-emitting element came for luminous one time period corresponding to second control signal Vscanner2 (1) time width.

The mode of operation (2) of second row comprises that similarly data write with luminous.In this case, the first control signal Vscanner1 translation one-level is come decline or the rising edge of response clock signal Vclock1.Therefore, under mode of operation (2), write data 2.Simultaneously, the second control signal Vscanner2 rises thereon along locating decline or the rising edge that translation backward comes response clock signal Vclock2, and similarly, its falling edge backward translation come rising edge or the negative edge of response clock signal Vclock2.Therefore, under mode of operation (2), light period is a translation time period T1 backward.

After this, mode of operation (3) ... after closelying follow in a similar fashion.Yet, should be noted that because under mode of operation (3), the rising edge of the second control signal Vscanner2 descends in the second transmission cycle T2 of clock signal Vclock2, it from it common timing backward time delay section T2-T1.Therefore, the problem of existence is that under mode of operation (3), when comparing with the mode of operation of other row, the elongated period T 2-T1 that reaches of light period causes different brightness.

Under mode of operation (4), translation backward is similar to mode of operation (3) to the clock signal Vclock2 that applies in the mode of operation (3) because it is in the first shorter transmission cycle T1, and it is longer that light period becomes.After this, under mode of operation (5), because the rising edge of clock signal Vclock2 just in time descends in the second transmission cycle T2 of the length of clock signal Vclock2, so luminous startups timing translation cycle T2-T1 backward.Therefore, the light period in the mode of operation (5) recovers its original state, and becomes identical with (2) with mode of operation (1).

In this manner, its first short-and-medium transmission cycle T1 and the second long transmission cycle T2 are included in the clock signal Vclock2 with hybrid mode, difference occurs between the light period in the different rows.If the time width of light period is fully long and approach the time width of a field, then the difference T2-T1 in cycle (horizontal cycle) has no relations in fact.For example, if light period is equivalent to 320 horizontal cycles, and the difference of light period between the row is a horizontal cycle, and then luminance difference is about 0.3% (=1/320), visually almost can not pick out.Yet under the very little situation of the horizontal cycle quantity of light period, this difference produces significant problem.For example, be equivalent at light period under the situation of 10 horizontal cycles, if the luminance difference between the row is equivalent to a horizontal cycle, then luminance difference is 10% (=1/10).Therefore, the luminance difference between the row becomes very obvious.

Fig. 7 represents to be used to eliminate according to the present invention the countermeasure of luminance difference between the above line.For the ease of understanding, come the sequential chart of pictorial image 7 to be similar to the mode that Fig. 6 represents.With reference to figure 7, according to illustrated countermeasure, apply shielded signal Vmask2 for the second control signal Vscanner2,, thereby regulate light period at the variation that the mixing owing to the second transmission cycle T2 causes so that disconnect the output of the second control signal Vscanner2 according to the second transmission cycle T2.Particularly, second scanner is with response clock signal Vclock2 and the second control signal Vscanner2 (i) that produces continuously and carry out logical and (AND) from the shielded signal Vmask2 of outside input synchronously with clock signal Vclock2, so that disconnect the output of the second control signal Vscanner2 (i).Therefore, when clock signal Vclock2 comprised the second transmission cycle T2 of the first transmission cycle T1 and ratio first transmission cycle T1 length, shielded signal Vmask2 should be controlled so that the second control signal Vscanner2 can disconnect in the part second transmission cycle T2.In this case, in order accurately to regulate light period, the break period T1 of shielded signal Vmask2 is preferably and equals T2-T1.Yet the phase relation of using other circuit in shielding causes under the situation of bad influence, shielding cycle and the unnecessary T2-T1 that accurately equals.In this case, to approach T2-T1 also out of question even the shielding cycle is set for, thereby the error packet between them contains in the scope of visually not seeing.

Preferably, the shielding timing that is applied to the second control signal Vscanner2 (i) was not carried out in the cycle that data write.If use shielding, then because pixel array portion is in not luminance temporarily, potential variation appears at the inside of pixel array portion sometimes.This potential variation writes influential sometimes to data.If the interim potential variation that causes owing to the shielding that is applied to the second control signal Vscanner2 has bad influence to data, then there is this possibility, carries out when promptly when using shielding, carrying out the pixel column that data write and using shielding between another pixel column that data write and luminance difference to occur.Therefore, in this example, the timing when pixel column execution data not being write, each pixel column is in not luminance temporarily.

In the mode of operation (1) of first-line pixel column, do not carrying out the timing that data write, pixel is controlled to not time period that is equivalent to a horizontal cycle of luminance.As a result, when comparing with the mode of operation shown in Fig. 6, light period has reduced by a horizontal cycle.In the mode of operation (2) of second row, light period has been lacked a horizontal cycle equally.In ensuing mode of operation (3), use shielding twice, therefore, light period has been lacked two horizontal cycles.As mentioned above, in mode of operation (3), light period is at first than the long horizontal cycle of the light period in mode of operation (1) and (2).Therefore, reduce light period and reach two horizontal cycles, can make light period equal light period in mode of operation (1) and (2) by using shielding.Similarly, in mode of operation (4),, light period is adjusted to the light period of other pixel columns equally by giving twice application of light period shielding.

Fig. 8 represents the structure example of second scanner, and second scanner is implemented this time sequential routine as shown in Figure 7.With reference to figure 8, second scanner that is used to control light period comprises a plurality of trigger SR, and they connect into multistage to form shift register.Each trigger SR response clock signal Vclock2 and moving, thus continuously transmission start pulse Vstart2 so as from each level or trigger SR the output second control signal Vscanner2 (i).In this case, be connected to each output stage of shift register, so that it carries out logical and (AND) from the shielded signal of outside input synchronously to second control signal that produced by the shift register side with clock signal Vclock2 with (AND) element.

The different operating mode of the image display device shown in Fig. 9 presentation graphs 1, concrete expression input to the clock signal Vclock1 of first scanner 3 and input to the waveform of the clock signal Vclock2 of second scanner 4.In addition, Fig. 9 illustrate pixel array portion 1 row pixel mode of operation (1), (2), (3) ....The clock signal Vclock1 of the first scanner response definition transmission cycle and moving, so that the data write operation of the pixel of control line, in defined transmission cycle, common first transmission cycle T1 and the second transmission cycle T2 longer than the first transmission cycle T1 mix in a field.Simultaneously, second scanner responds second clock signal Vclock2 and moves so that the light emission operation of the pixel column of control line, second clock signal Vclock2 is asynchronous with the first clock signal Vclock1, and definition is different from the 3rd transmission cycle T3 of the first transmission cycle T1 and the second transmission cycle T2.

The mode of operation of first-line pixel column (1) comprises write cycle and the light period that is positioned at a field.After this, be used for second line and rear wires mode of operation (2), (3) ... after closelying follow, write cycle and light period response clock signal Vclock1 and Vclock2 and translation continuously backward respectively simultaneously.Can find out obviously that from sequential chart the write cycle and the light period of line are asynchronous.In other words, can guarantee that the light period of every line always has the regular time width, and not be subjected to the influence of write cycle.In this case, preferably, the 3rd transmission cycle T3 of second control signal of being determined by clock signal Vclock2 fixes.Under the situation that the 3rd transmission cycle T3 fixes, the light period between these lines is fixed.Preferably, equal average period in the transmission cycle territory of the first control signal Vscanner1 that determines by clock signal Vclock1 by the transmission cycle of the second control signal Vscanner2 of clock signal Vclock2 definition.By aforesaid this setting,, can find out from sequential chart that they are that the unit is synchronous with the field although the write cycle of line and light period are asynchronous.Yet, should be noted that the clock that uses in the drive system according to image display device, the unnecessary relation of accurately setting between clock signal Vclock1 shown in Fig. 9 and the Vclock2.In this case, the 3rd transmission cycle T3 of clock signal Vclock2 can change in such scope for every sweep trace, and the luminance difference that is caused by light period in described scope is visually discerned to be come out.Under situation with cycle of aforesaid mode control clock signal Vclock1 and Vclock2, though normal show and wide demonstration between extracting scanning or conversion out, also can show not collinear between the high quality graphic of no luminance difference.

The ad hoc structure example of the image element circuit shown in Figure 10 presentation graphs 2.With reference to Figure 10, adjunct circuit 5 is inserted between driving transistors Tr3 and the sampling transistor Tr1.Adjunct circuit 5 comprises pixel capacitor Cs, coupling condenser Cc and correcting transistor Tr4 and Tr5.Coupling condenser Cc is coupled to the end of sampling transistor Tr1 the grid of driving transistors Tr3.Correcting transistor Tr4 is inserted between the grid and drain electrode of driving transistors Tr3, and is subjected to three scan line VSCAN3 (i) control.Correcting transistor Tr5 is connected to the end of predetermined migration current potential Vofs and coupling condenser Cc, and is connected to the 4th sweep trace VSCAN4 (i) at its grid place.

In the bottom of Figure 10, illustrate the sequential chart of the operation of the above-mentioned pixel 2 of expression.This sequential chart is represented the waveform of control signal, and described control signal imposes on the sweep trace VSCAN1 (i) that is connected to sampling transistor Tr1 grid, sweep trace VSCAN2 (i), the sweep trace VSCAN4 (i) that is connected to the sweep trace VSCAN3 (i) of correcting transistor Tr4 grid and is connected to correcting transistor Tr5 grid that is connected to the switching transistor Tr2 that carries out light emitting control.Simultaneously, also illustrate driving condition about the pixel column of i line.In illustrated driving condition (i), in calibration cycle,, in next write cycle, picture signal is write then the correction of dispersing of the threshold voltage of driving transistors Tr3.After this, driven light-emitting element OLED carries out luminously in light period, stops luminous then in remaining dark period.In order to carry out aforesaid sequence of operation, can find out that from sequential chart needs second to the 4th control signals (VSCAN2, VSCAN3 and VSCAN4) are synchronized with each other.On the other hand, first control signal (VSCAN1) does not need with other control signals synchronous.In calibration cycle, switching transistor Tr2 connects, and correcting transistor Tr4 and Tr5 connect the threshold voltage that detects driving transistors Tr3 simultaneously then, and it is write pixel capacitor Cs.By applying the threshold voltage according that is equivalent to detect for driving transistors Tr3, can cancel threshold voltage 4.In order to carry out this correct operation, need mutually synthetic control signal VSCAN2, VSCAN3 and VSCAN4.After this, the carries out image signal is to the write operation of pixel capacitor Cs and the light emission operation of connection light-emitting component.Write operation can be placed between correct operation and the light emission operation, and not require accurate adjusted in concert.Therefore, do not need the accurately synchronous first sweep trace VSCAN1 and other control signals VSCAN2, VSCAN3 and VSCAN4.

Figure 11 represents to impose on the waveform of clock signal of the scanner of image display device, and described image display device comprises the pixel 2 shown in Figure 10.Owing to need control signal VSCAN2, VSCAN3 and VSCAN4 synchronized with each other as mentioned above, so the waveform of clock signal Vclock2 is identical with the waveform of clock signal Vclock3 and Vclock4.Yet, the translation toward each other of their phase place.On the other hand, the waveform of clock signal Vclock1 is different with the waveform of other control signals VSCAN2, VSCAN3 and VSCAN4, and clock signal Vclock1 comprises short period and long period.This is essential extraction scanning between normal demonstration and wide demonstration and the conversion.

In the bottom of Figure 11, illustrate line mode of operation (1), (2), (3) ....Wired for institute, calibration cycle is placed on first, write cycle is immediately following thereafter, follow successively thereafter be light period.Can be placed between calibration cycle and the light period write cycle, and do not need accurate adjusted in concert.

Another particular instance of Figure 12 remarked pixel circuit.With reference to Figure 12, illustrated pixel 2 is modification of the pixel 2 shown in Figure 10.Particularly, still in this pixel 2, adjunct circuit 5 is inserted between sampling transistor Tr1 and the driving transistors Tr3.5 couples of driving transistors Tr3 of this adjunct circuit have the threshold voltage calibration function in addition.Adjunct circuit 5 comprises coupling condenser Cc, pixel capacitor Cs and two correcting transistor Tr4, Tr5.Correcting transistor Tr4 is connected to three scan line VSCAN3 (i) at its grid place.Correcting transistor Tr5 is connected to the 4th sweep trace VSCAN4 (i) at its grid place.

The sequential chart of this pixel of diagram 2 operations is shown in the bottom of Figure 12.This sequential chart represents to impose on the control signal of sweep trace VSCAN1 (i) to VSCAN4 (i), and the driving condition that is used for the pixel column of i line.With top similar with reference to the described driving condition of Figure 10, this driving condition comprises the calibration cycle that is positioned at its top.Write cycle is immediately following after the calibration cycle, follow successively thereafter be light period and dark period.In calibration cycle, need control signal synchronized with each other is imposed on sweep trace VSCAN2 (i), VSCAN3 (i) and VSCAN4 (i), so that the deviation of the threshold voltage of cancellation driving transistors Tr3.In the write cycle of back, the control signal that will be used to sample imposes on the first sweep trace VSCAN1 (i).This control signal does not need with other control signals synchronous.After this, the control signal that imposes on the second sweep trace VSCAN2 (i) is returned and is set as on-state, enters light period like this.In this manner, equally in this pixel 2, although need clock signal Vclock2 and clock signal Vclock3 and Vclock4 synchronized with each other, clock signal Vclock1 does not need with other clock signals Vclock2, Vclock3, Vclock4 synchronous.

The another structure example of Figure 13 remarked pixel 2.With reference to Figure 13, illustrated pixel 2 is top modification with reference to the described pixel 2 of Figure 10.Particularly, adjunct circuit 5 is inserted between sampling transistor Tr1 and the driving transistors Tr3.Adjunct circuit 5 comprises pixel capacitor Cs, correcting transistor Tr4 and correcting transistor Tr5, pixel capacitor Cs is connected between the grid and source electrode of driving transistors Tr3, correcting transistor Tr4 is connected between the source electrode and initialization current potential Vini of driving transistors Tr3, and correcting transistor Tr5 is connected between the grid and predetermined migration current potential Vofs of driving transistors Tr3.Correcting transistor Tr4 is connected to three scan line VSCAN3 (i) at its grid place.Correcting transistor Tr5 is connected to the 4th sweep trace VSCAN4 (i) at its grid place.

Sequential chart is shown in the bottom of Figure 13, and the not concrete normal operations state of extracting scanning out of carrying out of expression.In this case, clock signal VCLOCK1, VCLOCK2, VCLOCK3 and VCLOCK4 are supplied with all scanners, identical and their phase place of the waveform of these clock signals needs translation toward each other according to occasion.Response clock signal imposes on sweep trace VSCAN1 (i) respectively to VSCAN4 (i) with first to fourth control signal as shown in sequential chart.

Be shown in the foot of sequential chart about the driving condition of the pixel column of line i.In first calibration cycle, the sequential control pulse is imposed on sweep trace VSCAN3 (i), VSCAN4 (i) and VSCAN2 (i), so that detect the threshold voltage of driving transistors Tr3, and deposit it in pixel capacitor Cs.In this correct operation, need the phase relation between these control signals VSCAN2, VSCAN3 and the VSCAN4.After this, enter write cycle, in write cycle, first control signal imposed on the first sweep trace VSCAN1.Yet under this state, mobility (mobility) is proofreaied and correct in the end and is partly carried out.Carry out mobility like this and proofread and correct, set switching transistor Tr2 for on-state once so that impose at sampling image signal under the situation of driving transistors Tr3, thus the output current negative feedback flow to pixel capacitor Cs.Along with mobility increases, amount of negative feedback increases, and can cancel the deviation of the mobility [mu] of driving transistors Tr3.In the μ calibration cycle, need the phase relation between sweep trace VSCAN1 and the VSCAN2.According to obviously above-mentioned, according to this pixel 2, need be according to content of operation synchronous control signal VSCAN2, VSCAN3 and VSCAN4 or synchronous scanning line VSCAN1 and VSCAN2.

In the pixel 2 of Figure 13, because not concrete the execution extracted scanning out, so can use identical waveform for all clock signal Vclock1 to Vclock4.Therefore, do not pay particular attention to phase relation between the sweep trace VSCAN1 to VSCAN4.

Figure 14 represents the operation of the pixel 2 shown in Figure 13, wherein carries out and extracts scanning out.To extract scanning out in order carrying out,, need in light period, to have asynchronous each other different wave for clock signal Vclock1 and Vclock2.On the other hand, in V calibration cycle or μ calibration cycle,, need have identical waveform and have fixed phase relation for clock signal Vclock1 and Vclock2.Therefore, in the operation of Figure 14, clock signal Vclock2 is divided into a clock signal Vclock2-1 and another clock signal Vclock2-2, they use in calibration cycle and light period respectively.At calibration cycle with in write cycle, clock signal Vclock1, Vclock2-1, Vclock3 and Vclock4 use identical waveform so that keep phase relation between them.On the other hand, in light period, clock signal Vclock2-2 is used for controlling light period so that to the not influence of other clocks.Can prevent brightness deviation between the principal vertical line by this.

Figure 15 represents the structure of second scanner (vscanner2), is used to realize top with reference to the described operation of Figure 14.With reference to Figure 15, illustrated second scanner comprises two shift registers, that is: response clock signal Vclock2-1 and shift register moving and response clock signal Vclock2-2 and another shift register of moving.The first shift register response clock signal Vclock2-1 and continuous transmission start pulse Vstart2-1, so as from shift register at different levels the output control signal, generation is used to control the signal of calibration cycle according to starting impulse Vstart2-1.These control signals are exported to the OR circuit that provides for a plurality of levels separately.Second shift register responds another starting impulse Vstart2-2 and continuous transmission start pulse Vstart2-2, is separately the OR circuit that a plurality of levels provide so that control signal is exported to similarly, and starting impulse Vstart2-2 defines light period.The OR circuit that is positioned at places at different levels is to carrying out logical OR (OR) from the control signal of first shift register output with from the control signal of second shift register output, and the second control signal Vscanner2 (i) that will produce exports to second sweep trace of pel array side.

By the way, in the operation of the pixel of describing with reference to figure 72,, give and to apply shielded signal from second control signal output of second scanner output in the above for the fluorescent lifetime unevenness that prevents to cause by inhomogeneous clock signal.With reference to as described in the figure 7, if the time width of shielded signal Vmask2 is set T2-T1 for, then light period becomes uniformly in all sweep traces, has eliminated the luminance difference between the line simultaneously as top.

Yet this side effect as described below appears in operation according to the top pixel of describing with reference to figure 72 sometimes.One of side effect is owing to use shielded signal, and light period that can display device reduces the problem that causes screen intensity to reduce.Another side effect is because as the result who uses shielded signal, the current capacity that is included in each light-emitting component in the pixel array portion of flowing through changes suddenly, so may produce power supply noise.

Here should consider that for example, being presented at sweep trace quantity based on the picture signal of TSC-system formula is on 240 the display device, perhaps in other words, comprise 240 horizontal cycles in one of them or a frame.Use under the situation of light-emitting component as pixel in display device, usually be arranged such that and regulate a light period ratio in the field, thereby regulate screen intensity.Particularly, from the duty ratio of the control signal of second scanner output, i.e. control signal time period ratio for connecting in a field can be adjusted so that the control screen intensity.For example, the light period maximum is set at 220 horizontal cycles, and all the other 20 horizontal cycles are included in the dark period.The picture signal of TSC-system formula does not need to apply shielding to the control signal from the output of second scanner.

If the picture signal of pal mode inputs to above-mentioned display device, then will be equivalent to whole pal mode screen seven/one scan line quantity data amount and extract out in order on display device, to show.In this case, as mentioned above, the time period ratio that output shields to second scanner is per seven horizontal cycles once (1/7).Therefore, the maximum load of light period is 220 * 6/7, and therefore, screen intensity is reduced to 6/7.

In addition, when shielded signal rises, light-emitting component is arranged to not luminance, then, when shielded signal descended (disconnection), light-emitting component was luminous once more.Therefore, when shielded signal disconnects, the light-emitting component on the whole screen all never luminance convert luminance to.When not applying shielded signal, owing to the on/off that will carry out light-emitting component for each sweep trace, so the current capacity of power supply changes and be not really serious.Therefore, if apply shielded signal, then because light-emitting component is wanted on/off on whole screen, so the current capacity of power supply becomes very greatly.

In a word, the first, the problem that existed before the instruction of shielded signal is the luminance difference that is caused by the fluorescent lifetime difference.The second, another problem that the introducing shielded signal causes existing is that screen intensity (peak brightness) reduces.The 3rd, the another problem that the introducing shielded signal causes existing is the power supply load variations.Because first is relative to each other to the 3rd problem, their significance level is that long (screen intensity height) still lacked (screen intensity is low) and changed according to light period.

Suppose that at first light period is long, i.e. the screen intensity height.For example, in above-mentioned example, suppose that light period is set at 220 horizontal cycles.In this case, first problem is not serious, is not promptly applying the luminance difference problem that is caused by the fluorescent lifetime difference under the situation of shielding.This is because owing to do not apply shielding, even the light period between the sweep trace changes a horizontal scanning period, luminance difference is 1/220, and less than 0.5%, therefore visually can not discern fully.On the other hand, second problem is important, promptly introduces the problem that shielding causes peak brightness to reduce, because shielding is used brightness is reduced to 6/7 (less than 86%), and the influence of reduction is significant.Same the 3rd problem is very important, because when light period is length, because screen inherent certain moment (certain instant), luminous zone was very big, so descend so that allow light-emitting component to connect when next luminous when shielded signal, current capacity changes very greatly.

Now, suppose that light period is that weak point and screen intensity are low.In addition, suppose that light period is set at 10 horizontal cycles.In this case, about first problem, if the light period between the sweep trace differs a horizontal cycle, do not apply shielding simultaneously, then brightness is changed to 1/10=10%, and produces significant problem.On the other hand, about second problem, although screen intensity is reduced to 6/7, because light period is initially set weak point, thereby reduce screen intensity, it is not serious that such brightness reduces.In addition, can also regulate brightness in the signal level side.Equally about the 3rd problem, because under the short situation of light period, it is very little that the screen inherence is put luminous zone sometime, can think, when the cancellation shielded signal so that the current capacity when allowing driven light-emitting element luminous once more changes than littler under the long situation of light period.

Therefore, in the pixel 2 with reference to Figure 17 description, under the long situation of light period, output break period or shielding cycle that the output of second control signal keeps disconnecting are set at weak point in the above, but on the contrary, under the short situation of light period, the shielding cycle is set at length.This makes may prevent to occur luminance difference between sweep trace, relaxed the influence of screen intensity reduction or power supply load variations simultaneously.Under the situation that adopts this pixel 2 structures, can on image display device, realize high brightness and not have the high-quality display of luminance difference, described image display device shows the signal of different scanning line quantity on identical panel, perhaps have length breadth ratio be 4: 3 common display and another length breadth ratio be 16: 9 wide demonstration between switch the function of same signal.In addition, can implement image display device, wherein the variation of the current capacity of power supply is little, uses simple power circuit just can drive it.

Figure 16 represents the structure example of above-mentioned second scanner.With reference to Figure 16, second scanner that is used to control light period comprises the shift register with a plurality of register stage SR.Shift register response clock signal Vclock2 and moving so that transmission start pulse Vstart2 continuously, thus from different levels the output second control signal Vscanner2b (i).Here, be connected to each output stage of shift register with (AND) element, so that it is to carrying out logical and (AND) from the shielded signal of outside input synchronously by the second control signal Vscanner2b (i) of shift register side generation with clock signal Vclock2, so that obtain the second last control signal Vscanner2 (i).In Figure 16, the control signal before the shielding is represented with Vscanner2b (i), and the control signal after the shielding is represented with Vscanner2 (i), so that they are distinguished mutually.

Second scanner shown in Figure 16 changes the output break period or the shielding cycle responds light period, the output break period or in the shielding cycle output of the second control signal Vscanner2 (i) remain on the disconnected phase and respond second transmission cycle (T2), described light period depends on the time width of the second control signal Vscanner2 (i).Particularly, second scanner can be controlled output break period or the shielding cycle so that along with light period increases and reduces with changing.For example, second scanner can change the time width of the second control signal Vscanner2b (i), so that in such scope, regulate light period convertibly, described scope in a field from minimum light period (for example 10 horizontal cycles) to maximum light period (for example 220 horizontal cycles).In this case, second scanner is controlled the time width of the second control signal Vscanner2b (i), when being maximum light period with convenient light period, output break period or shielding cycle equal the first transmission cycle T1 and compare the poor of the second long transmission cycle T2 of the first transmission cycle T1.In addition, second scanner is controlled the time width of the second control signal Vscanner2b (i), and when being maximum light period with convenient light period, output break period or shielding cycle are zero.Preferably, when second scanner can be controlled shielding during the cycle with changing, the starting point in its fixed mask cycle and the terminal point that changes the shielding cycle responds the length of light period.

The different operating of Figure 17-19 expression second scanner, second scanner has top with reference to the described structure of Figure 16.The clock signal Vclock2 that supplies with the clock signal Vclock1 of first scanner and supply with second scanner is shown in the top of the sequential chart of Figure 17 to 19.In the operation shown in Figure 17-19, a field comprises 480 horizontal cycles, and the second transmission cycle T2 is set at 2 horizontal cycles, and the first transmission cycle T1 is set at a horizontal cycle simultaneously.Therefore, T2-T1 is a horizontal cycle.The same shielded signal Vmask2 that supplies with second scanner is shown in clock signal Vclock2.From to Figure 17-19, finding out, according to the second transmission cycle T2 output shielded signal Vmask2 of clock signal Vclock2.In addition, illustrate equally from first control signal Vscanner1 (i) of first scanner output and the second control signal Vscanner2b (i) that exports from second scanner.In the pixel array portion 1 of the pixel 2 that comprises Figure 16, shielded signal Vmask2 imposed on from the second control signal Vscanner2b (i) of second scanner output so that the second last control signal Vscanner2b (i) that obtains to export, thereby the light-emitting component of control pixel is so that be that the unit switches on and off with the sweep trace.The state table of sweep trace is shown as the mode of operation (i) that is positioned at the sequential chart bottom.Mode of operation (i) is divided into the dark period and the light period of picture signal write cycle, light-emitting component.

Figure 17 represents that a light period ratio in the field is set at the operation under the situation of minimum period.In this case, the time width of shielded signal Vmask2 is maximal value (T2-T1), and has eliminated the deviation of light period between the line fully.

Figure 18 represents that light period sets the operation under the situation of the intercycle between minimum period and the maximum cycle for.As can be seen, light period is about half of a field from mode of operation (1).In this case, the time width of shielded signal Vmask2 is less than T2-T1.Along with light period is elongated in such a way, the shielding cycle shortens.Though in Figure 18, ignored the number of pulses of shielded signal Vmask2, be actually with per seven horizontal cycles ratio output shielded signal Vmask2 once.Can suppress the reduction of screen intensity by the time width that reduces shielded signal.Yet, shorter if the shielding time becomes than T2-T1, although the luminance difference between the sweep trace can not be eliminated fully, may reduce luminance difference at least by using shielding.

Figure 19 represents that light period is set at the operation under the situation of maximum cycle.In this case, the time width of shielded signal Vmask2 is zero, and shielded signal Vmask2 is rendered as high level Hi usually.As a result, eliminate the luminance loss, the power supply load variations do not occurred.For example, be M horizontal cycle, minimum when being N horizontal cycle for zero horizontal cycle and the horizontal cycle selected to the maximum at light period, the time width of shielded signal can be set at 1-N/M horizontal cycle.Under the situation of setting light period by this way, when light period changed, the variation in shielding cycle became evenly, can carry out smoothly according to the brightness regulation that light period changes.Above-mentioned example is this situation, is the adjusting of carrying out the shielding cycle in the unit continuously with a horizontal cycle wherein.Yet according to the present invention, the time width in shielding cycle is not limited thereto, but can be from several to the variation step by step of tens steps in the scope from minimum light period to maximum light period.

Figure 20 represents the progressively conversion of the time width of shielded signal Vmask2.With reference to Figure 20, data are illustrated in top, and clock signal Vclock2 is illustrated in the middle part, and shielded signal Vmask2 is illustrated in the bottom.Be expressed as among the figure from these data, extracting i+1 data out.As mentioned above, owing to the light-emitting component on the whole screen all disconnected in the shielding cycle, so the load variations of power supply is very big, and may obtain noise.Therefore, preferably set the shielding cycle for such one-period, as shown in Figure 20, in the described cycle, do not carry out actual data and write.In addition, can regulate under the situation in shielding cycle according to light period considering, the situation of care is with changing, and the time point the when influence of image is disconnected again after shielded signal Vmask2 connection may be maximum.Therefore, can regulate under the situation in shielding cycle with changing, be preferably and carry out this regularly, wherein with light period never luminance turn back to luminance so that a time period was provided before next data writes.When light period is in hour, the terminal point in shielding cycle is set time t4 for.Along with light period increases, the progressively translation forward of terminal point in shielding cycle is as T3, T2 and T1.

Although used proprietary term to describe the preferred embodiments of the present invention, like this purpose of description should be thought just for the explanation that makes an explanation, and can change and change and do not break away from the essence or the scope of following claim.

Claims (10)

1, a kind of image display device comprises:

Pixel array portion; With

Be configured to drive the peripheral circuit part of described pixel array portion, wherein

Described pixel array portion comprise follow to many sweep traces that extend, along row to many signal wires that extend and by matrix arrangement in described sweep trace and the cross one another locational a plurality of pixels of described signal wire;

Described peripheral circuit partly has scanner and driver, wherein said scanner configurations becomes to provide the sequential scanning signal so that an enterprising line sequential scanning in field to described sweep trace in predetermined transmission cycle, and described drive configuration becomes to provide picture signal according to described line sequential scanning to described signal wire;

Each described pixel comprises sampling transistor, driving transistors, switching transistor and light-emitting component;

First control signal that the response of described sampling transistor provides from the first relevant sweep trace of described sweep trace and being switched on is so that the picture signal that sampling provides from one of relevant described signal wire;

The picture signal that described driving transistors response is sampled by described sampling transistor is supplied with described light-emitting component with output current;

Described light-emitting component sends the light that has according to the brightness of picture signal based on the output current that provides from described driving transistors;

Described switching transistor is arranged on the current path that output current flows through by this way: make response supply with from described second sweep trace its second control signal time width and present on-state, thereby this output current is supplied with described light-emitting component, so that described light-emitting component is luminous in light period according to this time width;

Described scanner is made up of first scanner and second scanner, and wherein said first scanner configurations becomes to supply this first control signal to this first sweep trace, and described second scanner configurations becomes to supply this second control signal to this second sweep trace;

The described first scanner response definition comprise common first transmission cycle and than first transmission cycle long and be blended in second transmission cycle in first transmission cycle transmission cycle clock signal and move so that at first transmission cycle be blended in and in second transmission cycle in first transmission cycle first control signal sequentially supplied with first sweep trace;

Described second scanner response moves with being used for the clock signal clock signal synchronous of described first scanner, so that second control signal is sequentially supplied with second sweep trace, wherein, because the mixing of first transmission cycle and second transmission cycle, the time width of second control signal of definition light period all changes for every row; And

Described second scanner disconnects the output of second control signal according to second transmission cycle, regulates light period thereby contrast the variation that is caused by the mixing of second transmission cycle.

2, image display device according to claim 1, wherein for equaling the time width of first transmission cycle with the difference of second transmission cycle of growing than first transmission cycle, described second scanner is controlled to off-state with the output of second control signal.

3, image display device according to claim 1 is wherein exported to first sweep trace in the timing of timing of first control signal being different from described first scanner, and described second scanner disconnects the output of second control signal of corresponding second sweep trace.

4, image display device according to claim 1, wherein said second scanner is with response clock signal and second control signal that order produces and synchronously carry out logical and (AND) from the shielded signal of outside input with clock signal, so that the output of second control signal is controlled to off-state.

5, image display device according to claim 1, wherein said pixel array portion has the sweep trace of predetermined quantity, and when described driver according to the line sequential scanning to described signal wire output quantity during greater than the picture signal of the first sweep trace quantity, first transmission cycle of described first scanner in a field and be blended in second transmission cycle in first transmission cycle first control signal sequentially is provided, thus be that the unit is extracted the unwanted picture signal out with the sweep trace.

6, image display device according to claim 1, wherein said second scanner response depends on that the light period of the time width of second control signal changes the output break period, in described output break period, the output of this second control signal is controlled so as to off-state according to second transmission cycle.

7, image display device according to claim 6, wherein said second scanner can be controlled the output break period with changing, so that along with light period increases and reduces.

8, image display device according to claim 7, wherein said second scanner can change the time width of second control signal, thereby in from the minimum light period in the field to the scope of maximum light period, can regulate light period with changing, and when control output break period was minimum light period with convenient light period, this output break period equaled the poor of first transmission cycle and second transmission cycle of growing than first transmission cycle.

9, image display device according to claim 8, wherein said second scanner control output break period, this output break period is zero when being maximum light period with convenient light period.

10, image display device according to claim 7, wherein, when described second scanner can be controlled the output break period with changing, described second scanner was fixed the starting point of output break period and is changed the length that the terminal point of exporting break period responds light period.

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