CN100541581C - Semiconductor devices and driving method thereof - Google Patents
Semiconductor devices and driving method thereof Download PDFInfo
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- CN100541581C CN100541581C CNB2004100639755A CN200410063975A CN100541581C CN 100541581 C CN100541581 C CN 100541581C CN B2004100639755 A CNB2004100639755 A CN B2004100639755A CN 200410063975 A CN200410063975 A CN 200410063975A CN 100541581 C CN100541581 C CN 100541581C
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Abstract
A kind of semiconductor devices, wherein marking current is fast in the imported current source circuit of write current.Owing to carry out precharge operation write signal electric current afterwards, therefore can write fast.In precharge operation, electric current is provided to a plurality of circuit.The size of electric current is set according to the quantity of the circuit that is provided this electric current, this means to obtain stable state fast.Attention is provided electric current in precharge operation circuit can not be to be transfused to the circuit of signal.
Description
Technical field
The present invention relates to a kind of semiconductor devices, it has the function of the transistor controls utilized to the power supply of load, especially relate to a kind of semiconductor devices, it comprises the pixel that is made of current driven light-emitting element, the brightness of this light-emitting component changes along with electric current, with the signal drive circuit that is used to drive this pixel, also relate to a kind of driving method of this semiconductor devices.
Background technology
In recent years, the display device that its pixel is made of the light-emitting component as light emitting diode (LED), promptly self-emitting display device is applied in the pointolite.At the above-mentioned light-emitting component that is used for self-emitting display device, Organic Light Emitting Diode (OLED), organic EL and electroluminescence (EL element) have caused pays close attention to and is widely used in OLED display.
Because this light-emitting component is luminous by self, has higher pixel visibility and does not need backlight so compare it with LCD.In addition, it shows high response speed and can control the brightness of this light-emitting component according to the current value that flows into light-emitting component.
Passive matrix driving and driven with active matrix are known as the driving method of the display device that uses self-emission device.Though it is simple in structure that passive matrix drives, and has such problem, as be difficult to realize the display of large scale and high brightness.Therefore, develop driven with active matrix energetically, wherein by being arranged on the electric current that flows through in thin film transistor (TFT) (TFT) the control light-emitting component in the pixel circuit.
The problem that active matrix display device exists is exactly, because of the variation of the current characteristics of drive TFT causes that the electric current that flows through in the light-emitting component changes, and causes that thus the brightness of each light-emitting component of formation display screen changes.In other words, active matrix display device has the drive TFT of the light-emitting component of the wherein inflow current that is used for driving pixel circuit, and because of the characteristic variations of drive TFT causes that the electric current that flows through light-emitting component changes, so brightness changes.
Therefore consider the problems referred to above, propose different circuit,, and suppress brightness change (for example referring to patent documentation 1 to 4) when the characteristic of the drive TFT in the pixel circuit changes even so that the electric current that flows through in the light-emitting component does not change yet.
[patent documentation 1]
The open No.2002-517806 of Japanese patent unexamined
[patent documentation 2]
International publication No.01/06484 separate edition (pamphlet)
[patent documentation 3]
The open No.2002-514320 of Japanese patent unexamined
[patent documentation 4]
International publication No.02/39420 separate edition
Disclose the structure of active matrix display device in the patent documentation 1 to 4, especially disclose circuit structure in patent documentation 1 to 3, wherein the characteristic variations of drive TFT does not cause that the electric current that flows through light-emitting component changes in the pixel circuit.This structure is called electric current once-type pixel or the imported pixel of electric current.Patent documentation 4 is disclosed to be circuit structure, and it is used for suppressing the variation of the marking current that the variation because of source driver circuit TFT causes.
The structure of disclosed conventional active matrix display device in the patent documentation 1 has been shown among Fig. 6.Pixel among Fig. 6 comprises source signal line 601, the first to the 3rd gate signal lines 602 to 604, supply lines 605, TFT606 to 609, holding capacitor 610, EL element 611 and the current source that is used for incoming video signal 612.
The gate electrode of TFT 606 is connected to first grid signal wire 602, and its first electrode is connected to source signal line 601, and its second electrode is connected to first electrode of TFT 607,608 and 609.The gate electrode of TFT 607 is connected to the second gate signal line 603, and its second electrode is connected to the gate electrode of TFT 608.Second electrode of TFT 608 is connected to supply lines 605.The gate electrode of TFT 609 is connected to the 3rd gate signal line 604, and its second electrode is connected to the anode of EL element 611.Holding capacitor 610 is connected between the gate electrode of TFT 608 and the supply lines 605 with the grid of storage TFT 608 and the voltage between the source electrode.The negative electrode of supply lines 605 and EL element 611 is imported predetermined voltage respectively so that have a potential difference (PD) between the two.
To utilize Fig. 7 A to explain by marking current and write photoemissive operation to 7E.Represent the Reference numeral of each parts consistent with shown in Fig. 6.Fig. 7 A has schematically shown the flow direction of electric current to 7C.Fig. 7 D illustrates marking current and writes relation between the electric current that is flowed in fashionable each path.Fig. 7 E illustrates stored voltage in the holding capacitor 610, and promptly marking current is write the grid of fashionable TFT 608 and the voltage between the source electrode.
At first, input pulse and TFT 606 and 607 conductings in the first grid signal wire 602 and the second gate signal line 603.Flow through the electric current of source signal line 601, promptly marking current is expressed as Idata at this.
Shown in Fig. 7 A, because marking current Idata flows through source signal line 601, so this electric current flows through current path I1 and I2 in the pixel respectively.Fig. 7 D illustrates the relation between the electric current.Much less, this relation table is shown Idata=I1+I2.
When the moment of TFT 606 conductings electric charge also be not stored in the holding capacitor 610, so TFT608 ends.Therefore, I2=0 and Idata=I1.In other words, because of making, the accumulation of the electric charge in the holding capacitor 610 have only a kind of electric current to flow during this period.
Then electric charge builds up in the holding capacitor 610, and begins to produce potential difference (PD) between two electrodes of holding capacitor 610 (seeing Fig. 7 E).(Fig. 7 E mid point A) TFT 608 conductings when the potential difference (PD) between the two poles of the earth reaches Vth, and produce I2.Because Idata=I1+I2 as mentioned above is so I1 reduces gradually.But, still have electric current to flow through and holding capacitor 610 in electric charge further accumulate.
Electric charge continues the potential difference (PD) of accumulation between two electrodes of holding capacitor 610 in the holding capacitor 610, be that the canopy utmost point of TFT 608 and the voltage between the source electrode reach expectation voltage, this expectation voltage is a kind of like this voltage (VGS), can flow through electric current I data among the TFT 608 under this voltage.When electric charge accumulation is finished (the B point among Fig. 7 E), electric current I 1 stop to flow and this moment corresponding VGS electric current begin to flow among the TFT608, therefore satisfy Idata=I2 (seeing Fig. 7 B).By this way, obtain stable state.Therefore signal writing operation is finished.When the selection of the first grid signal wire 602 and the second gate signal line 603 was finished, TFT 606 and 607 ended.
In ensuing optical transmission operation, input pulse and TFT 609 conductings in the 3rd gate signal line 604.Because the VGS that writes before is stored in the holding capacitor 610, so TFT 608 conductings and electric current I data flow out from supply lines 605.Therefore, EL element 611 is luminous.Can be operated at TFT 608 under the situation of saturation region, even the voltage between the source electrode of TFT 608 and the drain electrode changes, Idata can not continue to flow through in this point with changing yet.
Be used to export operating in of electric current of setting as mentioned above and refer to output function here.The advantage of above-mentioned electric current once-type pixel is exactly, the expectation electric current accurately can be offered EL element, even and when TFT 608 has characteristic variations etc., voltage because electric current I data flows between needed grid and the source electrode can be stored in the holding capacitor 610, therefore can suppress the brightness that the characteristic variations because of TFT causes and change.
The foregoing description relates to a kind of technology that is used for proofreading and correct the electric current variation that causes because of the variation in the pixel circuit drive TFT; But identical problem appears in the source driver circuit.Disclose a kind of circuit structure in the patent documentation 4, it is used for preventing the variation because of the caused marking current of manufacture deviation of source driver circuit TFT.
Conventional current driving circuit and adopt the display device of this circuit to constitute by this way, make relation between the electric current of marking current and drive TFT or marking current and the electric current that during the light emission, flows through in the photocell between relation can equate or keep being proportional to one another.
Very little or light-emitting component shows that marking current is corresponding to be reduced under the situation of low key tone (dark gradation) at the drive current of the drive TFT that is used for driven light-emitting element.Because it is very big to be used for marking current is provided to the stray capacitance of wiring of drive TFT and light-emitting component, so when marking current hour, the charging rate of the stray capacitance in this wiring will become greatly, this makes the reduction of signal writing speed.In other words, thereby it is slack-off in the speed that transistorized gate terminal produces voltage that electric current is provided to transistor, and this transistor needs this voltage so that electric current flows.
Based on foregoing problems, after deliberation a kind of technology (for example referring to patent documentation 5 and 6) that is used to improve the signal writing speed.
[patent documentation 5]
Jap.P. has been examined open No.2003-50564
[patent documentation 6]
Jap.P. has been examined open No.2003-76327
Patent documentation 5 discloses a kind of display device, and it has current control device, and the data line electric current that is provided by data line driving device is divided into by this device and is used for monochrome information is written to the data current of each pixel circuit and the by-pass current that is used to drive.For example, as shown in figure 33, the pixel circuit that does not wherein write brightness data is as data current control circuit (by-pass current).
Figure 34 and 35 illustrates the driving sequential.Select a continuous x pixel circuit (x=2 among Figure 33) simultaneously.When selecting two pixel circuits simultaneously, the partial data line current that is used for driving data lines is written to a pixel circuit as the brightness data electric current.Do not write the brightness data electric current in the part of another pixel circuit, still, it is used as data current control circuit (by-pass current), and remaining data line electric current flows into wherein.
Especially, among Figure 35, continuous x the pixel circuit (x=2 among Figure 33) of same row is divided into a unit.When data current is written to pixel circuit in this unit, there is not data current to be written to another pixel circuit in this unit and this pixel circuit as by-pass current.Meanwhile, in the pixel circuit that has data current to write, select the first sweep trace WS and the second sweep trace ES.Among Figure 33, for example suppose that pixel circuit 11-k-1 is the pixel circuit that is used to write data current, WSk-1 and Esk-1 are selected so.
On the other hand, not having data current to write and being used as in the pixel circuit of by-pass current, only select the first sweep trace WS.Select WSk among Figure 33 and do not select the second sweep trace ESk.Therefore, this pixel circuit serves as the data current control circuit, and wherein TFT 24 and 25 is as by-pass current.In other words, in pixel circuit shown in Figure 33, because the second sweep trace ESk does not have selected and TFT 26 ends, so stoped and be stored in brightness data corresponding charge in the capacitor 23 and discharged by TFT 26 and keep being stored.Meanwhile, the part in this circuit promptly has only TFT 24 and 25 to serve as data current control circuit (by-pass current).
As mentioned above, in the active matrix organic EL display apparatus that utilizes electric current once-type pixel circuit, select two continuous pixel circuits of same column simultaneously, and the part of data line electric current I w0 is provided to pixel circuit being written into brightness data, and remaining electric current is provided to the part of another pixel circuit as by-pass current.Like this, can set data line electric current I w0 bigger, suppress the size of TFT 24 in the pixel circuit and 25 simultaneously than the data current Iw1 that flows through TFT 24 and 25.Therefore, may significantly reduce the data write time, therefore the organic EL display device that helps realizing having large scale and high definition.
Patent documentation 6 discloses circuit shown in Figure 36.In other words, driving transistors 7 is connected in parallel with auxiliary transistor 12, wherein the current driving ability of auxiliary transistor 12 be driving transistors 7 n doubly, make leakage current also flow to this auxiliary transistor 12 like this and the marking current (accelerating period) during part is selected that flows through signal wire 3 becomes (n+1) doubly.Therefore, can carry out the charging and the discharge of holding capacitor and capacitor parasitics with very fast speed, and the grid potential of driving transistors do not weaken during selecting and reaches predetermined potential (failing), even therefore can come the drive current driving element with suitable drive current under the situation of little marking current (input signal) yet.Therefore, when current driving element was organic EL, the drive current that this organic EL can be scheduled drove and therefore prevents the deterioration of displayed image quality.
Summary of the invention
As mentioned above, though after deliberation improve the technology of signal writing speed, but still have several problems.
For example, in the patent documentation 5, though select continuous two pixel circuits (x=2) of same column in the write data electric current, the quantity of pixel circuit is not limited to two also can select more pixel circuits simultaneously.When selecting more pixel circuits and a plurality of pixel circuit, can realize the transistor of smaller szie in the pixel circuit, promptly bigger data line electric current I w0 as the data current pulse.
But it is farther to consider that compromise factor makes that spacing between the transistor that constitutes current mirroring circuit becomes, and has therefore reduced the effect of deviation in the correcting transistor characteristic.
Therefore, simultaneously the quantity of selecteed pixel circuit is restricted and the size of data line electric current also is restricted.Therefore, reduced the signal writing speed.In addition, when selecting a plurality of pixel circuit simultaneously, electric current is divided into the electric current that flows through each pixel circuit.It hinders precise current and is imported in the pixel circuit of wherein importing data current.Therefore reduced the effect of deviation in the correcting transistor characteristic.
In the patent documentation 6, driving transistors 7 is connected in parallel with auxiliary transistor 12, wherein the current driving ability of auxiliary transistor 12 be driving transistors 7 n doubly, make leakage current also flow to this auxiliary transistor 12 like this and the part (acceleration during) of marking current during selecting that flow through signal wire 3 becomes (n+1) doubly.
But, too many if the quantity of n increases, so auxiliary transistor 12 shared areas will become greatly and so reduce aperture efficiency (opening ratio).In addition, the quantity of n is subjected to the restriction of layout area.Therefore the magnification that the part (during the acceleration) during part is selected flows through the marking current of signal wire 3 reduces.The result makes the signal writing speed reduce.
For addressing the above problem, the object of the present invention is to provide a kind of technology,, and not limited by layout area even it also can fully improve the signal writing speed under the little situation of marking current, do not reduce aperture efficiency, and do not reduce the effect of correcting action in the transistor characteristic.
According to the present invention, be provided with between a precharge phase to finish setting operation fast before during setting.In precharge operation, electric current not only flow to will input signal transistor also flow to other transistor.The size of this electric current increases according to the increase of the transistorized quantity that will be provided this electric current.Therefore, very big electric current can be flow through, therefore stable state can be obtained fast.The state of noting this moment almost is equivalent to the state that setting operation is finished (when obtaining stable state).Then, carry out setting operation.So can finish this setting operation fast owing to before carrying out setting operation, obtained almost to be equivalent to the state that setting operation finishes.
Notice that setting operation is a kind of like this operation, it provides current to and will be transfused to the transistor of signal, therefore produces voltage in transistorized gate terminal, and this transistor needs this voltage that electric current is flowed.
In addition, be used to make electric current not only to flow to the transistor of input signal but also flow to other transistor and be called precharge operation, and the circuit that will have such function is called pre-charging device with the operation of finishing setting operation fast.
Characteristics of the present invention are semiconductor devices, and it comprises signal wire; Can be connected to the current source circuit of this signal wire by switch; The a plurality of element circuits that comprise switch and current source circuit respectively; And electric supply installation, it provides the current source circuit of first electric current to the M that is selected from these an a plurality of element circuits element circuit between precharge phase, and second electric current is provided to the current source circuit of N the element circuit that is selected from these a plurality of element circuits during setting.
Current source circuit comprises at least one transistor, and in most cases also comprises capacitor.
When adopting little electric current when carrying out setting operation, take a long time the arrival stable state and finish the electric current write operation to element circuit (constituting the transistor of current source circuit).For addressing this problem, before setting operation, carry out precharge operation.By this precharge operation, can before this setting operation, almost be equivalent to the state of stable state.In other words, precharge operation makes that extremely quickly charging to a current potential at the transistor gate that constitutes current source circuit becomes possibility.By this precharge operation, constitute the extreme current potential of the transistor gate of the current source circuit current potential during setting operation no better than.Therefore, can finish this setting operation more quickly by after precharge operation, carrying out setting operation.
Another feature of the present invention is a semiconductor devices, and it comprises: signal wire; Can be connected to the current source circuit of this signal wire by switch; The a plurality of element circuits that comprise switch and current source circuit respectively; And electric supply installation, it is provided to first electric current current source circuit of M the element circuit that is selected from these a plurality of element circuits between precharge phase, and second electric current is provided to the current source circuit of removing N element circuit outside this M element circuit that is selected from these a plurality of element circuits during setting.
In other words, usually, consider that the characteristic deviation expectation carries out precharge operation to these circuit, this circuit comprises the element circuit that will carry out setting operation to it, yet, the invention is not restricted to this.Can be different from the element circuit that it is carried out setting operation to its element circuit that carries out precharge operation.
According to said structure, the invention provides the wherein semiconductor devices of N=1.
Though usually an element circuit is carried out setting operation, the invention is not restricted to this and in setting operation, can provide electric current to a plurality of element circuits.
In addition, according to said structure, the size that the invention provides wherein first electric current and second electric current is than being the semiconductor devices of M: N.
Transistor of the present invention can adopt the transistor of any kind.For example, can be utilize unbodied, the thin film transistor (TFT) of semiconductor film polycrystalline or monocrystalline (TFT).Also can adopt and be formed on single crystalline substrate, SOI substrate, or the transistor on the glass substrate.Perhaps, can adopt the transistor that carbon nano-tube (carbonnanotube) etc. form by organic material.In addition, transistor can be MOS transistor or bipolar transistor.
Notice in this instructions that connection is meant electrical connection.Therefore, can shown in insert other element or switch between the element.
According to the present invention, precharge operation carried out before setting operation.Therefore, even adopt little electric current also can carry out setting operation fast, and can in output function, export precise current.
Description of drawings
Fig. 1 is the structured flowchart of semiconductor devices of the present invention.
Fig. 2 shows the block diagram of the structure example of element circuit of the present invention.
Fig. 3 shows the block diagram of a kind of operation of semiconductor devices of the present invention.
Fig. 4 shows the block diagram of a kind of operation of semiconductor devices of the present invention.
Fig. 5 shows the block diagram of a kind of operation of semiconductor devices of the present invention.
Fig. 6 shows the block diagram of the structure example of conventional pixel.
Fig. 7 A illustrates the operation of conventional pixel to the block diagram of 7E.
Fig. 8 shows the block diagram of the structure example of element circuit of the present invention.
Fig. 9 is the structured flowchart of semiconductor devices of the present invention.
Figure 10 is the structured flowchart of semiconductor devices of the present invention.
Figure 11 shows the block diagram of the structure example of element circuit of the present invention.
Figure 12 shows the block diagram of the structure example of element circuit of the present invention.
Figure 13 shows the block diagram of the operation of semiconductor devices of the present invention.
Figure 14 shows the block diagram of the operation of semiconductor devices of the present invention.
Figure 15 shows the block diagram of the operation of semiconductor devices of the present invention.
Figure 16 shows the block diagram of the operation of semiconductor devices of the present invention.
Figure 17 is the operational block diagram that is used to explain semiconductor devices of the present invention.
Figure 18 shows the block diagram of the operation of semiconductor devices of the present invention.
Figure 19 shows the block diagram of the operation of semiconductor devices of the present invention.
Figure 20 shows the block diagram of the operation of semiconductor devices of the present invention.
Figure 21 shows the block diagram of the operation of semiconductor devices of the present invention.
Figure 22 shows the block diagram of the operation of semiconductor devices of the present invention.
Figure 23 shows the block diagram of the structure example of element circuit of the present invention.
The block diagram of Figure 24 illustrates the structure example of element circuit of the present invention.
Figure 25 shows the block diagram of the structure example of element circuit of the present invention.
Figure 26 shows the block diagram of the structure example of element circuit of the present invention.
Figure 27 shows the block diagram of the structure example of element circuit of the present invention.
Figure 28 shows the block diagram of the structure example of element circuit of the present invention.
Figure 29 shows the block diagram of the structure of display device of the present invention.
Figure 30 shows the block diagram of the structure of display device of the present invention.
Figure 31 shows the block diagram of the structure of gate driver circuit of the present invention.
Figure 32 A is the view that can use electronic installation of the present invention to 32H.
Figure 33 shows the block diagram of the structure of conventional pixel.
Figure 34 is the time diagram of conventional pixel.
Figure 35 is the time diagram of conventional pixel.
Figure 36 shows the block diagram of the structure of conventional pixel.
Figure 37 shows the block diagram of the structure of semiconductor devices of the present invention.
Figure 38 shows the block diagram of the structure of semiconductor devices of the present invention.
Embodiment
[embodiment 1]
According to the present invention, pixel is by forming according to the element that the current value that flows into light-emitting component is controlled photoemissive brightness.Typically, can adopt EL element.Though the various structures of EL element are known, can adopt any structure as long as it can control photoemissive brightness according to current value.In other words, can adopt such EL element, it comprises the luminescent layer of combination in any, charge-transport layer and electric charge injection layer, this EL element is used the low-molecular-weight organic material, in the molecular weight organic material (do not have the distillation characteristic and wherein the quantity of molecule be 20 still less or the length of strand be 10 ì m or luminous organic material still less), or high molecular weight organic materials forms.In addition, inorganic material can be mixed or is distributed in these organic materials.
The present invention also can be used for various mimic channels, and each circuit also comprises current source except that the pixel that includes light-emitting component such as EL element respectively.Therefore, principle of the present invention is described in the present embodiment.
Structure based on ultimate principle of the present invention is shown in Figure 1.Master current source 101 is connected to signal wire 108 by switch 102, and auxiliary current source 103 is connected in parallel by switch 104 and master current source 101.Electric supply installation constitutes by this way.Much less the structure of electric supply installation is not limited to that shown in Fig. 1, and any structure can adopt as long as it can provide the element circuit of scheduled current to the back according to the time sequential routine.For example, can save switch and adopt its output current source of variation on demand.The quantity of current source is not limited to two, perhaps can adopt more a plurality of current circuits or a current circuit.
A plurality of element circuit 105a are connected to signal wire 108 to 105e.Among Fig. 1, be connected with five element circuits.Each element circuit comprises at least one on-off circuit and a current source circuit, so element circuit 105a for example, comprises on-off circuit 106a and current source circuit 107a.Be applied to remaining element circuit 105b equally to 105e.Current source circuit comprises at least one transistor, and also comprises capacitor as a rule.On-off circuit comprises at least one switch.
Element circuit can adopt various structures.According to present embodiment, figure 2 illustrates the element circuit that utilizes with the similar circuit of Fig. 6.On-off circuit 106 in the element circuit 105 is corresponding to the TFT606 among Fig. 6.Current source circuit 107 in the element circuit 105 comprises current source transistor 208, capacitor 210 and switch 207 and 209.Load 201 is connected to switch 209.Transistor 208 in the current source circuit 107 is corresponding to the TFT among Fig. 6 608, and capacitor 210 is corresponding to holding capacitor 610, and switch 207 and 209 corresponds respectively to TFT 607 and 609.Load 201 is corresponding to the EL element among Fig. 6 611.
The operation of the circuit shown in the key drawing 1 now.Carry out precharge operation at first, as shown in Figure 3.Electric current not only is provided in precharge operation will have the element circuit of signal input but also be provided to other element circuit.The size of total current increases with the quantity of the increase of the element circuit that will be provided electric current.
In other words, switch 104 is connected and switch 102 turn-offs and makes electric current flow out from auxiliary current source 103.Then, each on-off circuit connection and the electric current in a plurality of element circuits begins to flow to these on-off circuits.Among Fig. 3, on-off circuit 106a connects to 106e, so electric current flows into this five element circuits.Therefore, are five times of master current source 101 from the electric current of auxiliary current source 103.Like this, owing to big electric current can be provided to circuit, so obtain stable state very soon.In precharge operation, the current potential of the signal wire 108 when obtaining stable state is expressed as Vp.
Attention is during precharge operation, and preferably the gate terminal and the drain electrode end of the current source transistor in each current source circuit are connected with each other.Among Fig. 2, for example, preferred switch 207 is connected.In addition, switch 209 turn-offs to prevent that electric current from flowing in the load 201 among preferred Fig. 2.Yet the present invention is not limited to these.
Then, as shown in Figure 4, carry out setting operation.Here hypothesis has only element circuit 105a will be transfused to signal.In other words, electric current only is provided to element circuit 105a and is not provided to element circuit 105b to 105e.Therefore, on-off circuit 106a connects and on-off circuit 106b turn-offs to 106e.Switch 104 turn-offs and thereby switch 102 is connected electric current from master current source 101 outflows.Yet, so owing to the very little stable state that obtains routinely of electric current that flows out from master current source 101 need take a long time.And under the situation of Fig. 4, owing to before setting operation, carried out precharge operation, so the current potential of signal wire 108 equals Vp.The current potential of this current potential Vp signal wire 108 when setting operation is finished no better than.Therefore, can finish setting operation fast and also reach stable state very soon.
As mentioned above, (between precharge phase) provides big electric current in precharge operation.For example, when doubly electric current of providing A, its A that is provided to element circuit props up (piece).By this big electric current, can obtain stable state fast.In other words, can reduce the influence that causes because of parasitic load (line impedance, cross-over connection electric capacity etc.) and also therefore obtain stable state fast the streaming current circuit.During ensuing setting, provide electric current to an element circuit of one times to carry out setting operation.Yet, the current potential of the current potential of streaming current circuit when setting operation is finished no better than.This is because of the quantity (A) of the magnification of the electric current in the precharge operation (A doubly) corresponding to the element circuit that is provided electric current.As mentioned above, precharge operation can make setting operation finish fast.
Therefore, for example when load 201 was EL element, promptly being used in the photoemissive write signal of EL element was under the situation of inferior grade (gradation), and in other words, even little electric current is provided in setting operation, signal also can write fast.
In addition, the current potential of the current potential of signal wire when setting operation is finished no better than when precharge operation is finished.When they equate each other fully, just mean that setting operation finishes simultaneously when precharge operation is finished.In other words, when they not exclusively equated each other, potential difference (PD) was controlled by setting operation.Therefore, it is little to suppress to begin when it finishes being changed to of current potential the signal wire from setting operation, therefore can obtain stable state very soon.
The current potential of signal wire when whether the current potential of signal wire equaled setting operation and finish when precharge operation was finished depends on the deviation of current source circuit 107a current characteristics of each current source transistor in the 107e.When current characteristics did not change, the grid of current source transistor and the voltage between the source electrode equaled the voltage between the two in the setting operation in the precharge operation.Yet, when current characteristics changes, in the charging operations in the grid of current source transistor and the voltage between the source electrode and the setting operation voltage between the two different.Therefore, when precharge operation is finished and setting operation when finishing, the current potential in the signal wire 108 is inequality.Therefore expect that current source circuit 107a each current source transistor in the 107e has identical current characteristics.This makes it possible to obtain fast stable state in setting operation.The consistance of current characteristics can obtain by shine each transistorized semiconductor layer with identical Laser emission in crystallization in the current source transistor.
Though note having adopted five element circuits among Fig. 1, the quantity of element circuit is not limited to this.
In addition, though electric current is input in five element circuits of Fig. 3 in precharge operation, the present invention is not limited to this.For example electric current can be input to four element circuits as shown in Figure 5.In this case, the electric current of preferred auxiliary current source 103 is four times of master current source 101.In addition, though on-off circuit 106b connects and on-off circuit 106a shutoff to 106e in Fig. 5, the present invention is not limited to this.Because hypothesis has only element circuit 105a to be transfused to signal, so consider the deviation of transistorized current characteristics, preferably electric current is input to element circuit 105a in precharge operation.Yet as shown in Figure 5, precharge operation can carry out under the situation that on-off circuit 106a turn-offs, and electric current just is not input among the element circuit 105a like this.
Though electric current is input to an element circuit among Fig. 4 in setting operation, the present invention is not limited to this.For example electric current can be imported into a plurality of element circuits.The size of current of master current source 101 just need increase according to the quantity of element circuit like this.
In addition, though signal wire 108 is connected to current source circuit 107a each in the 107e by on-off circuit 106a to 106e respectively among Fig. 1, the present invention is not limited to this.It can adopt any structure as long as can control the selection that is input to the electric current of element circuit 105a each to the 105e from signal wire 108.Though electric current is input to each element circuit by signal wire 108 among Fig. 1, for example, interchangeable for example voltage signal can be input to element circuit by other circuit.
Though among Fig. 3 in precharge operation switch 102 turn-off and switch 104 is connected, the present invention is not limited to this.If size of current is controlled, can provide electric current from master current source 101 and auxiliary current source 103 simultaneously by connecting switch 102.
Among Fig. 1, for describing easily, signal wire 108 is connected to master current source 101 and is connected to auxiliary current source 103 by switch 104 by switch 102, but the present invention is not limited to this.It can adopt any structure as long as can control the size of current that is provided to signal wire 108 in precharge operation and setting operation.Therefore switch 102 and 104 can be arranged on any position as long as the size of current that provides from master current source 101 and auxiliary current source 103 can be provided for they.When each master current source 101 and auxiliary current source 103 have the function of switching current output, can save switch 102 and 104.In addition, if master current source 101 and auxiliary current source 103 have the function of switching current size between precharge operation and setting operation, they can be integrated into a current source so.
In addition, though electric current flows to master current source 101 or auxiliary current source 103 from element circuit among Fig. 1 to 4, the present invention is not limited to this.Electric current can flow to element circuit from master current source 101 and auxiliary current source 103.Yet, in this case, must consider the current source circuit in each element circuit.For example when adopting the structure of current source circuit shown in Figure 2, the polarity of current source transistor 208 need be transformed to the N-channel-type from the P-channel-type.This is because transistorized source terminal and drain electrode end will be corresponding to the flow direction conversions of electric current.Flow to element circuit at electric current from master current source 101 or auxiliary current source 103, and the polarity of current source transistor is under the situation of P-channel-type, must adopts structure shown in Figure 8.Among Fig. 8, capacitor 810 is connected between the grid and source electrode of current source transistor 808.Because the size of current that flows through in the transistor depends on the voltage between transistorized grid and the source electrode, so need the grid of memory transistor and the voltage between the source electrode.Therefore, capacitor 810 need be connected between the grid and source electrode of current source transistor 808.In addition, switch 807 is connected between the grid and drain electrode of current source transistor 808.Like this, because transistorized gate terminal and source terminal depend on the flow direction of electric current, i.e. potential level is so need the correspondingly structure of decision-making circuit.
Capacitor 210 among Fig. 2 or the capacitor 810 among Fig. 8 can in this case, can save capacitor 210 and 810 with the replacements such as grid capacitor of current source transistor 208.
Though capacitor 210 is connected to the gate terminal and the source terminal of current source transistor 208, the present invention is not limited to this.It would be desirable that capacitor 210 is connected between the gate terminal and source terminal of current source transistor 208.This is because the voltage between grid and the source electrode is depended in transistorized work, and therefore when storage voltage between gate terminal and source terminal, transistor is not subject to other influence (as the pressure drop that causes because of line impedance).If capacitor 210 is arranged between the gate terminal and other circuit of current source transistor 208, the extreme current potential of the canopy of current source transistor 208 will change because of the pressure drop in the circuit so.
Though five current source circuit 107a have been shown to 107e among Fig. 1, the current capacity of each current source circuit, promptly the grid width W of each current source transistor and grid length L can be identical or different in all element circuits.In element circuit the current capacity of each current source not simultaneously, the current potential of signal wire 108 is set to almost be equal to each other in the time of need obtaining stable state in precharge operation and setting operation.
Switch shown in Fig. 1 etc. can be any switch such as electric switch or mechanical switch.It can be any element or circuit, as long as it can Control current.It can be a transistor, diode or comprise transistor and the logical circuit of diode.Therefore, utilizing transistor to do under the situation of switch, because it does not limit especially as its polarity of switch (electric conductivity).But, when preferred cut-off current is very little, preferably adopt polar transistor with little cut-off current.For example, provide the transistor in LDD district to have little cut-off current.In addition, it is desirable to, when the extreme current potential of source transistor as switch approaches low potential side (Vss, during Vgnd, 0V etc.) power supply potential, adopt the n-channel transistor, when the current potential of source terminal approaches the power supply potential of hot side (Vdd etc.), adopt the p-channel transistor.Owing to can increase the absolute value of voltage between transistor gate and the source electrode, so this helps the valid function of switch.Also can adopt cmos switch by utilizing n-raceway groove and p-channel transistor.
Circuit structure of the present invention is not limited to Fig. 1, those shown in 2 and 8.By the quantity of change element circuit, the quantity of current source, the quantity of switch and structure, each transistorized polarity, the quantity of current source transistor and structure, the current potential of each circuit, flow direction of electric current or the like can provide various circuit structures.Equally, by these changes are combined, can provide multiple circuit structure in addition.
Under the situation of Fig. 1, carry out next carrying out setting operation as shown in Figure 4 as Fig. 3 or precharge operation shown in Figure 5, still, the present invention is not limited to this.
For example, can carry out repeatedly as Fig. 3 or precharge operation shown in Figure 5.For example, in first time precharge operation, the electric current of five times of sizes is input to as shown in Figure 3 five element circuits, in second time precharge operation, the electric current of three times of sizes is input to as shown in Figure 9 three element circuits, at last, when setting operation, the electric current of one times of size is input to an element circuit.
By carrying out repeatedly precharge operation by this way, can continue ensuing setting operation effectively.
Perhaps, can be in conjunction with other precharge operation.
For example, as shown in figure 10, before precharge operation shown in Figure 3, can carry out other precharge operation.Among Figure 10, provide voltage from terminals 1001 by switch 1002.It in precharge operation and setting operation is the current potential when obtaining stable state with this potential setting.In other words, as shown in figure 10, switch 1002 is connected to provide current potential at terminals 1001 places.By applying voltage, can instantaneously flow through very big electric current, therefore, can carry out precharge operation fast.Then, switch 1002 turn-offs to carry out precharge operation as shown in Figure 3.Notice that the method that adopts voltage source to carry out precharge operation discloses in same applicant's Japanese patent application No.2003-019240.Various pre-charge methods are wherein disclosed and its content can combine with the application.
In addition, the precharge operation that changes by a plurality of steps of the size of current that wherein flows through in each element circuit (current source circuit) for example, can with combine as the pre-charge circuit shown among Fig. 3.Show the structure that the electric current that flows through in the current source circuit 107 wherein can be transformed to a plurality of grades among Figure 11 and 12 respectively.
Under the situation of Figure 11, second current source transistor 1111 is connected in series to current source transistor 1108.In addition, be provided for the source electrode of short circuit second current source transistor 1111 and the switch 1112 of drain electrode.When switch 1112 turn-offs, because the gate terminal of the current source transistor 1108 and second current source transistor 1111 interconnects, so each in the current source transistor 1108 and second current source transistor 1111 is served as multi-gated transistor.The grid length L of this multi-gated transistor is bigger than the grid length of current source transistor 1108, so the electric current that flows through in the multi-gated transistor is very little.On the other hand, when switch 1112 is connected, so because the source electrode of second current source transistor 1111 and drain electrode are not had electric current to flow through by short circuit between them.In other words, actual have only current source transistor 1108 to work.Like this, the size of current that flows in the current source transistor 1108 can change by the connection/shutoff of switch 1112.By before Fig. 3 or the operation shown in Figure 4 and afterwards or during carry out such operation, can finish precharge operation more quickly.
Among Figure 12, they are one another in series in Figure 11 and are connected though second current source transistor 1211 and current source transistor 1208 are connected in parallel.Same in this case, when big electric current is provided to current source circuit 107, can make electric current flow to second current source transistor 1211 by connecting switch 1212.
The structure of attention shown in Figure 11 and 12 is open in same applicant's Japanese patent application No.2003-055018, is a plurality of grades with the current transformation that flows through in the current source circuit 107 wherein.Various structures are disclosed in this application and its content can combine with the application.
It is desirable to, the transistor that uses in the transistor that uses in the precharge operation and the setting operation has identical characteristic as far as possible.For example under the situation of Fig. 1, it is desirable to current source circuit 107a and all have identical current characteristics with 1211 to the current source transistor 208,808,1108,1208 and second current source transistor 1111 among the 107e.Therefore, in the formation step of the current source transistor and second current source transistor, expectation gives each transistor and has identical current characteristics as far as possible.For example, under the situation of the semiconductor laser of using the laser radiation current source transistor and second current source transistor, the irradiation of preferred laser makes current source transistor have identical current characteristics with second current source transistor.Therefore, under the situation of irradiation linear laser, preferably along the direction irradiating laser that is parallel to signal wire 108 and along this laser of scanning direction perpendicular to signal wire 108.
Attention is under the situation that each master current source 101 and auxiliary current source 103 are made of the transistor that works in the saturation region, and each gate electrode preferably is connected to each other.In addition, the size of current of each current source is preferably by regulating the control recently of each transistorized grid width W and grid length L.
As mentioned above, by changing the quantity and the structure of switch, each transistorized polarity, the quantity of current source transistor and structure, the type of master current source, quantity and structure, the quantity of element circuit and structure, the structure of current source circuit in the element circuit, the number of times of precharge operation combines or not combination with other pre-charge method, flow direction of electric current or the like the invention provides various circuit structures.Equally, by in conjunction with these changes, can provide a greater variety of circuit structures.
[embodiment 2]
With reference to the described embodiment 1 of figure 1-4 is this situation, is transfused to the element circuit of signal, and the element circuit that promptly carries out setting operation is element circuit 105a.The operation that present embodiment is described is that wherein to carry out the unit of setting operation be continually varying in time.
Though what operation as described herein was adopted is structure shown in Figure 1, structure and operation are not limited to these.In addition, embodiment 1 can be combined with present embodiment.
Be convenient and describe that the quantity of supposing to be transfused to the element circuit of signal in precharge operation is 3, still, the quantity that is transfused to the element circuit of signal in precharge operation is not limited to these.
At first, hypothesis is transfused to the element circuit of signal here, and the element circuit that promptly carries out setting operation is element circuit 105a.Before setting operation, element circuit 105a is carried out precharge operation.Here describe for convenient, carry out precharge operation by making electric current flow to three element circuits.So, as shown in figure 13, flow to element circuit 105b, 105c, 105d and carry out precharge operation by making electric current.
Electric current is input to element circuit 105b, 105c, 105d is as follows as the reason to the precharge operation of element circuit 105a before setting operation: the first module circuit that carries out setting operation is element circuit 105a, second element circuit is element circuit 105b, the 3rd element circuit is element circuit 105c, and the 4th element circuit is element circuit 105d.This expression, when electric current is imported into element circuit when carrying out setting operation after the precharge operation, the state of element circuit can change according to structure.Therefore, if carry out setting operation immediately after the precharge, can provide electric current so as precharge operation.
On the other hand, even under the also immovable situation of state of input current element circuit when element circuit carries out setting operation after as precharge operation, can be to this element circuit rather than element circuit 105b, 105c, 105d carries out precharge operation.
Preferably the state of signal wire 108 does not change between setting operation and precharge operation.For this reason, the element circuit (current source circuit) that is used for setting operation expects to have identical current characteristics with the element circuit that is used for precharge operation (current source circuit).So, it is desirable to, utilize the element circuit that is arranged near element circuit 105a (carrying out the element circuit of setting operation) to carry out precharge operation.Much less precharge operation can utilize element circuit 105a (carrying out the element circuit of setting operation) to carry out.
As mentioned above, under the situation that the state of element circuit changes when electric current is provided to element circuit and carries out setting operation after as precharge operation, preferably after precharge operation, select to be used to carry out the element circuit of setting operation.Under the situation that the state of element circuit when carrying out setting operation does not change, the preferred element circuit arranged near the element circuit that is used to carry out setting operation selected.But the present invention is not limited to this.
Next, after precharge operation shown in Figure 13, element circuit 105a is carried out as shown in figure 14 setting operation.
Suppose to be transfused to the element circuit of signal, the element circuit that promptly carries out setting operation now is element circuit 105b, then carries out precharge operation before element circuit 105b is carried out setting operation.Precharge operation flows to element circuit 105c by making electric current, 105d and 105e and carry out as shown in figure 15.Attention has just finished at setting operation makes electric current flow to element circuit 105a as precharge operation.
Next, element circuit 105b is carried out as shown in figure 16 setting operation.
As mentioned above, the unit that carries out setting operation continuously changes in time, so precharge operation and setting operation carry out shown in Figure 17 and 18.
Attention was carried out under the situation of precharge operation before to the setting operation of element circuit 105c, did not have element circuit after the element circuit 105e.In this case, the first module circuit can have electric current to flow through conduct to element circuit 105d, the precharge operation of 105e and 105a.The operation of this moment is shown in Figure 17 and 18.
Similarly, passing is in time being carried out element circuit 105d under the situation of setting operation, and by making electric current flow to element circuit 105e, 105a and 105b carry out precharge operation as shown in figure 19.Afterwards, as shown in figure 20 element circuit 105d is carried out setting operation.Shown in Figure 21 and 22, carry out precharge operation and setting operation in a similar fashion.
By circuit is carried out aforesaid operation, can carry out setting operation to each element circuit in proper order.By before setting operation, carrying out precharge operation, promptly use very little electric current also can carry out setting operation fast.
Under the situation of carrying out precharge operation, electric current flows to and is not will carry out the element circuit of the element circuit of setting operation after precharge, and still, the present invention is not limited to this.For example, as shown in figure 14 element circuit 105a is being carried out under the situation of setting operation, electric current can flow to element circuit 105a in precharge operation before, and element circuit 105a also carries out as shown in figure 21 rather than setting operation shown in Figure 13.
Notice that present embodiment is described corresponding to the specifying of a certain operation of carrying out according to embodiment 1 described structure, yet the present invention is not limited to this.Therefore, can be except that the various variations the variation that breaks away from this paper scope.Therefore, embodiment 1 also can be applied to present embodiment.
[embodiment 3]
As implement Fig. 2 in the mode 1, shown in 8,11,12 grades, element circuit can adopt various structures.In the present embodiment, with other example and the operation of description unit circuit.
Figure 23 shows an example of circuit.In circuit shown in Figure 23, the grid of transistor 2309 and the voltage vanishing between the source electrode when switch 207 is connected.Therefore, transistor 2309 turn-offs and electric current does not flow to load 201.Therefore, when carrying out precharge operation, switch 106 and 207 can be connected.Attention is in circuit shown in Figure 23, and when electric current flows to element circuit when carrying out precharge operation, the state of this element circuit changes when carrying out setting operation.Therefore, preferably after precharge, just provide current to load until carrying out setting operation.Can connect switch 207 when in this case, switch 106 turn-offs.When stopcock 106, electric current does not flow to this element circuit.On the other hand, so do not flow to load 201 because switch 207 is connected electric current.Flow at electric current under the situation of load 201, switch 106 and 207 can turn-off.In addition, when carrying out setting operation, switch 106 and 207 can be connected.
Figure 24 shows another example.In circuit shown in Figure 24, the grid of transistor 2409 and the voltage vanishing between the source electrode when switch 2407 is connected.Therefore, transistor 2409 shutoffs and electric current do not flow to load 201 from power lead 2413.Therefore, when carrying out precharge operation, switch 106 and 2407 can be connected.Yet, need to connect switch 2411 so that electric current flows to lead 2412 and do not flow to load 201.Electric current flows to load 201 hardly when the current potential of lead 2412 is controlled.But, under the situation that electric current still flows, can stopcock 209.In circuit shown in Figure 24, the state of element circuit changes when being provided to element circuit at electric current and carrying out setting operation after making precharge operation.Therefore, preferably after precharge, just make electric current flow to load up to carrying out setting operation.Therefore, in this case, can also can connect switch 2407 by stopcock 106, in addition can stopcock 209.By stopcock 106, electric current does not flow to element circuit.Electric current did not flow to load 201 from power lead 2413 when simultaneously, switch 2407 was connected.When electric current flows to load 201, can also can connect switch 209 by stopcock 106,2407 and 2411.When carrying out setting operation, can connect switch 106,2407 and 2411.
Notice that the structure shown in Figure 23 and 24 is disclosed by same applicant's Japanese patent application No.2002-274680.Its content can combine with the present invention.
Shown in Figure 25 and 26 is the example that adopts current mirroring circuit.Among Figure 25, when electric current flows to element circuit when making precharge operation, the state of this element circuit changes when carrying out setting operation.Therefore, need to use switch 2509 to come Control current to flow to load 201.But among Figure 26, even when electric current is provided to element circuit and makes precharge operation, the state of this element circuit does not change yet when stopcock 2601 carries out setting operation.That is to say that the signal of storage does not change in the capacitor 2510.Therefore, even electric current also can flow to load 201 when carrying out precharge operation.
Figure 27 shows another example.Figure 28 shows the object lesson of the circuit of Figure 27.Structure shown in Figure 27 and 28 and mode of operation are disclosed by same applicant's international publication No.03/027997 separate edition (pamphlet).Its content can combine with the present invention.
Described the element circuit of various structures in the present embodiment, still, the present invention is not limited to these, can be except that the various changes the change that breaks away from this paper scope.In addition, the described content of present embodiment can be carried out independent assortment with embodiment 1 and 2.
[embodiment 4]
What present embodiment was explained is the structure and the operation of display device, signal drive circuit etc.Circuit of the present invention can be applied to the parts of signal drive circuit and pixel.
As shown in figure 29, display device comprises cell array 2901, gate driver circuit 2902 and signal drive circuit 2910.Gate driver circuit 2902 output continuously selects signal to cell array 2901.Signal drive circuit 2910 continuous outputting video signals are to cell array 2901.Cell array 2901 is controlled brightness with display image according to vision signal.The vision signal that outputs to cell array 2901 from signal drive circuit 2910 is electric current as a rule.In other words, being arranged on display element and being used in each pixel controls the state of the element of this display element and changes according to the vision signal (electric current) from signal drive circuit 2910 inputs.The typical case's representative that is arranged on the display element in the pixel is EL element or is used for element of FED (Field Emission Display) or the like.
The quantity of signal drive circuit 2902 and signal drive circuit 2910 can be more than one.
Pixel comprises the display element as EL element, and this display element has the circuit of output current (vision signal), i.e. current source circuit, and the present invention also can be used for this current source circuit.
Hereinafter with the operation of brief explanation signal drive circuit 2910.Shift register 2903 comprises a plurality of lines of flip-flop circuit (FF) etc., and input clock signal (S-CLK), starting impulse (SP) and inversion clock signal (S-CLKb).According to the sequential of these signals, order is exported sampling pulse.
Be input to first latch circuit (LAT1) 2904 from the sampling pulse of shift register 2903 outputs.In first latch circuit (LAT1) 2904, vision signal is from video signal cable 2908 inputs, and the sequential of importing according to sampled signal is stored in vision signal in the every line.This vision signal has digital value under the situation that D-A converter circuit 2906 is set.The vision signal in this stage generally is a voltage signal.
But, can store at first latch circuit (LAT1) 2904 and second latch circuit (LAT2) 2905 under the situation of the analogue value and can save D-A converter circuit 2906.In this case, vision signal electric current normally.Equally, when the data that output to cell array 2901 have binary value, promptly during digital value, in most cases can save D-A converter circuit 2906.
When in vision signal is stored in the last item line of first latch circuit (LAT1) 2904, finishing, during horizontal flyback sweep, import latch pulses, and the vision signal that is stored in first latch circuit (LAT1) 2904 all is transferred to second latch circuit (LAT2) 2905 simultaneously from breech lock control line 2909.Next, the delegation's vision signal that is stored in second latch circuit (LAT2) 2905 is input to D-A converter circuit 2906 simultaneously.Then, the signal from D/A conversion circuit 2906 outputs is imported into cell array 2901.
When the vision signal in being stored in second latch circuit (LAT2) 2905 is imported into D-A converter circuit 2906 and is input to cell array 2901, sampling pulse output in shift register 2903 once more.In other words, two operations are carried out simultaneously.Therefore, enabling the row order drives.Repeat this operation in the same way.
Attention is carried out under the situation of setting operation and output function at the current source circuit of D-A converter circuit 2906, needs current source circuit to have to be used for the circuit of output current.In this case, reference current source circuit 2914 is set.
Equally, according to the present invention, the type of the substrate that transistor and transistor are formed thereon is not limited to described above.Therefore, can on glass substrate, plastic, mono-crystalline substrate or SOI substrate, form entire circuit shown in Figure 29 or 30.Incidentally, not that all parts of circuit shown in Figure 29 or 30 all must be formed on the same substrate, the part of circuit can be formed on the different substrates.For example, among Figure 29 and 30, can use TFT that cell array 2901 and gate driver circuit 2902 are formed on the glass substrate together and signal drive circuit 2910 (or its part) is formed on the mono-crystalline substrate, adopt COG (glass top chip) to engage then the IC chip is connected on this glass substrate.Also can adopt TAB (winding engages automatically), printed substrates etc. to replace the COG welding.
In other words, signal drive circuit and its part can not be formed on the same substrate with cell array 2901, and for example it can form with exterior I C chip.
The structure of signal drive circuit etc. is not limited to structure shown in Figure 29.
For example, can store under the situation of the analogue value at first latch circuit (LAT1) 2904 and second latch circuit (LAT2) 2905, as shown in figure 30, vision signal (analog current) can be input to first latch circuit (LAT1) 2904 from reference current source circuit 2914.Among Figure 30 second latch circuit (LAT2) 2905 can be set under some situation.The current source circuit of greater number is set in first latch circuit (LAT1) 2904 in this case, usually.
For example, two current source circuits can be set, one of them carries out setting operation and another execution routine operation.These functions also can be changed.Therefore setting operation and routine operation can carry out simultaneously.
The concrete structure of current source circuit is open to the separate edition of No.03/038797 etc. by international publication No.03/038793.They can be applicable to the present invention or combine with structure of the present invention.
For example, the present invention can be used for the current source circuit of Figure 29 D-A converter circuit 2906, and D-A converter circuit 2906 comprises a plurality of element circuits, and reference current source circuit 2914 comprises master current source 101 and auxiliary current source 103.
The present invention also can be applied to the current source circuit of first latch circuit (LAT1) 2904 shown in Figure 30.First latch circuit (LAT1) 2904 comprises a plurality of element circuits, and reference current source circuit 2914 comprises master current source 101 and auxiliary current source 103.
Equally, the present invention can be applied to the pixel (current source in this pixel) in the cell array 2901 of Figure 29 and 30.Cell array 2901 comprises a plurality of element circuits, and signal drive circuit 2910 comprises master current source 101 and auxiliary current source 103.
Figure 31 illustrates the example of gate driver circuit 2902.A plurality of switch elements in the element circuit (switch element 106a is to 106e among Fig. 1) are connected between precharge phase.During setting, one of these switch elements are connected.Then, as shown in figure 31, the signal of connecting the multirow pixel is from shift register 3101 inputs.On the other hand, connect the signal of delegation's pixel from shift register 3102 inputs.By control control signal wire 3103, shift register 3101 and 3102 output are transformed into each gate line.
Connection/shutoffs of noting other switch in the pixel (element circuit) also can be controlled by gate driver circuit with technology like same.
Applying the present invention under the situation of pixel, between precharge phase, be not provided to load (as light-emitting component) according to the structure electric current of pixel (element circuit).Under this situation, light-emitting component is not luminous.Therefore, obtain the pulsed light emission of light emission a period of time in a frame period, rather than during a frame period, continue luminous lasting light emission.Continuing under the photoemissive situation, when show be live image the time since afterimage effect afterimage can be retained in the human eye, and under the situation of pulsed light emission, even what show is that live image also can not keep afterimage.Therefore, when the present invention is used for pixel, the afterimage in the time of can suppressing the live image demonstration.
Notice that present embodiment utilized embodiment 1 to 3, therefore, embodiment 1 can be used in present embodiment to 3.
[embodiment 5]
Embodiment before is described to be the situation that electric current is provided by signal wire, and still, the present invention is not limited to this.Not only can provide electric current also can provide voltage.For example, the application can be in conjunction with same applicant's the disclosed technology of Japanese patent application No.2003-123000.
As shown in figure 37, according to Japanese patent application No.2003-123000, not only can provide electric current also can provide voltage.Provide voltage by utilizing amplifier circuit 3707 to form feedback circuit.Here omit the specific descriptions of its operation.
Figure 38 is illustrated in the situation that a plurality of transistors 3808 are set in the current source circuit shown in Figure 37.Here, operational amplifier 3707 is as amplifier circuit.Though be easy two transistors (or pixel) that are provided with in current source circuit of description here, its quantity is not limited to this.
As shown in figure 38, be provided with element circuit 105A and 105B.Simultaneously, be provided with the signal wire 3803 that is used to provide the signal wire 108 of electric current and is used to provide voltage.These signal wires are connected to current source circuit in each element circuit by on-off circuit (switch 106A and 3807A) etc.By controlling the on-off circuit (switch 106A and 3807A and switch 106B and 3807B) in each element circuit, carry out precharge operation and setting operation.Therefore, write signal fast.
Though make current source for only showing current source 3701 among the easy Figure 38 that describes, the size of electric current can be controlled in precharge operation and setting operation.Current source 3701 can comprise switch 102 and 104 as shown in Figure 1, master current source 101, auxiliary current source 103 or the like.
[embodiment 6]
Among Figure 13 to 21, five element circuit 105a are connected to signal wire 108 to 105e, and precharge operation is undertaken by electric current being provided to three element circuits.In the display device of reality, signal wire is connected to more pixel, promptly more element circuit.
For example, in the display device of mobile phone, adopt vertical long screen, so signal wire is connected to 320 pixels (element circuit) with QVGA.And in the display device of auto-navigation system, adopt the long screen of level with VGA, so signal wire is connected to 480 pixels (element circuit).In addition, in the display device of personal computer, adopt the long screen of level, so signal wire is connected to 768 pixels (element circuit) with XGA.
Described below is when signal wire is connected to a plurality of pixels (element circuit), will be provided the quantity of the pixel (element circuit) of electric current in precharge operation.
It is desirable in precharge operation, have the pixel (element circuit) that will be provided electric current as much as possible.This is because because the electrorheological that flows through must be big more, can obtain stable state fast more in precharge operation.But when current value increases when too many, power attenuation also increases.In addition, when the quantity of the pixel (element circuit) that will be provided electric current in precharge operation increased, the quantity that can make electric current flow to the pixel of light-emitting component may reduce.In other words because the setting operation data of storing may be damaged by precharge operation, institute think the data presentation that prevents mistake a certain period electric current can not be provided to light-emitting component.As a result, dutycycle may reduce, and causes the lost of life of light-emitting component.Therefore, the quantity that will be provided the pixel of electric current in precharge operation can be traded off definite according to these.
For example, when electric current in precharge operation is provided to 50 pixels (element circuit), current value can be 50 times big in the precharge operation.In the mobile phone that utilizes QVGA to show, signal wire is connected to 320 pixels (element circuit), and therefore, the ratio that will be provided the pixel (element circuit) of electric current in the precharge operation is 50/320=16%.The dutycycle of this moment is (320-50)/320=84%, and this in allowed limits.When current value in the precharge operation can reach 50 times big or small, can shorten the time that reaches stable state.Particularly, comprise that in mobile phone the load capacitance of signal wire is very little under the situation of little display part (cell array part) and short signal wire.Therefore, utilize 50 times or bigger current value, can shorten the time that reaches stable state fully.Therefore, the quantity that will be provided the pixel (element circuit) of electric current in the preferred precharge operation is 50 or more, and the ratio that will be provided the pixel (element circuit) of electric current in the precharge operation is 16% or bigger, and dutycycle is 84% or still less.
But, when dutycycle is 5% or still less the time, the life-span of light-emitting component can shorten.Therefore, the quantity that expectation determines will to be provided in the precharge operation pixel (element circuit) of electric current makes to have 5% or bigger dutycycle, and is more preferably 10% or bigger.
For example, when electric current in the precharge operation offered 100 pixels (element circuit), the current value in the precharge operation can be arranged to 100 times of sizes.In the display device of the auto-navigation system that uses VGA to show, signal wire is connected to 480 pixels (element circuit), and therefore, the ratio that will be provided the pixel (element circuit) of electric current in the precharge operation is 100/480=20%.The dutycycle of this moment is (480-100)/480=79%, and this in allowed limits.When the current value in the precharge operation can be arranged to 100 times big or small, can shorten the time that reaches stable state.Especially, in the display device of auto-navigation system, because display unit (cell array parts) is not very big and signal wire is not very long, so the load capacitance of signal wire is not very big.Therefore, 100 times of uses or bigger current value can shorten the stable state ground time that reaches fully.Therefore, the quantity that will be provided the pixel (element circuit) of electric current in the preferred precharge operation is 100 or more, and the ratio that will be provided the pixel (element circuit) of electric current in the precharge operation is 20% or higher, and dutycycle is 79% or still less.
But, when dutycycle is 5% or still less the time, the life-span of light-emitting component may shorten.Therefore, expectation determines that the quantity that will be provided the pixel (element circuit) of electric current in the precharge operation makes that dutycycle is 5% or higher, preferably 10% or higher.
For example, when electric current in the precharge operation offered 200 pixels (element circuit), the current value in the precharge operation can be arranged to 200 times of sizes.In the display device of the personal computer with XGA demonstration, signal wire is connected to 768 pixels (element circuit), and therefore, the ratio that will be provided the pixel (element circuit) of electric current in the precharge operation is 200/768=26%.The dutycycle of this moment is (768-200)/768=73%, and this in allowed limits.When the current value in the precharge operation can be arranged to 200 times big or small, can shorten the time that reaches stable state.Therefore, the quantity that will be provided the pixel (element circuit) of electric current in the preferred precharge operation is 200 or more, and providing the ratio of the pixel (element circuit) of electric current in the preferred precharge operation is 26% or higher, and dutycycle is 73% or still less.
But, when dutycycle is 5% or still less the time, the life-span of light-emitting component may shorten.Therefore, expectation determines that the quantity that will be provided the pixel (element circuit) of electric current in the precharge operation makes that dutycycle is 5% or higher, preferably 10% or higher.
Notice that the quantity that will be provided the pixel of electric current in the precharge operation is not limited to top described.For example, thus the quantity that will be provided the pixel of electric current in the precharge operation can increase and has about 50% dutycycle.
[embodiment 7]
The present invention can be applied to electronic system such as video camera, digital camera, safety goggles display (display of wear-type), navigational system, sound reproducing equipment (automobile audio, audio element or the like), laptop personal computer, game station, portable data assistance (mobile computer, portable phone, portable game station or digital book or the like), have image reproducing equipment (equipment that especially has display, this display is play such recording medium and the displayed image of digital multifunctional CD (DVD)) of recording medium or the like.The object lesson of these electronic equipments at Figure 32 A to shown in the 32H.
Figure 32 A shows a luminaire, and it comprises housing 13001, bracing frame 13002, display part 13003, speaker portion 13004, video inputs 13005 or the like.The present invention can be applied in the circuit of display part 13003.Further, according to the present invention, finish the luminaire shown in Figure 32 A.Because this luminaire is emissive type,, and obtain the display part thinner than LCD so do not need backlightly.Luminaire comprises the display device of the display message that is useful on, as personal computer, and the display device of TV radio receiver and advertising display panel.
Figure 32 B shows a digital camera, and it comprises main body 13101, display part 13102, visual receiving unit 13103, operating key 13104, external connection port 13105, shutter 13106 or the like.The present invention can be applied in the circuit of display part 13102.Further, according to the present invention, finish the digital camera shown in Figure 32 B.
Figure 32 C shows a laptop personal computer, and it comprises main body 13201, housing 13202, display unit 13203, keyboard 13204, external connection port 13205, pointer mouse 13206 or the like.The present invention can be applied in the circuit of display part 13203.Further, according to the present invention, finish the laptop personal computer shown in Figure 32 C.
Figure 32 D shows mobile computer, and it comprises main body 13301, display unit 13302, switch 13303, operating key 13304, infrared optical interface 13305 or the like.The present invention can be applied in the circuit of display part 13302.Further, according to the present invention, finish the portable computer shown in Figure 32 D.
Figure 32 E shows a portable image reproducing equipment (being the DVD reproducing apparatus specifically) with recording medium, it comprises main body 13401, housing 13402, display part A 13403, display part B13404, recording medium (DVD etc.), reading section 13405, operating key 13406, speaker portion 13407 or the like.Display part A 13403 main subsequently displaying transmitted image datas, and display part B 13404 main videotex data.The present invention can be applied to the circuit among display part A 13403 and the B 13404.Notice that the image reproducing equipment with recording medium comprises household game equipment or the like.Further, according to the present invention, finish the DVD reproducing apparatus shown in Figure 32 E.
Figure 32 F shows a safety goggles display (head mounted display), and it comprises main body 13501, display part 13502, arm 13503 or the like.The present invention can be applied in the circuit of display part 13502.Further, according to the present invention, finish the safety goggles display shown in Figure 32 F.
Figure 32 G shows a video camera, and it comprises main body 13601, display part 13602, housing 13603, external connection port 13604, remote control receiving unit 13605, visual receiving unit 13606, battery 13607, audio frequency importation 13608, operating key 13609 or the like.The present invention can be applied in the circuit of display part 13602.Further, according to the present invention, finish the video camera shown in Figure 32 G.
Figure 32 H shows a mobile phone, and it comprises main body 13701, housing 13702, and display part 13703, audio frequency importation 13704, audio output part divides 13705, operating key 13706, external connection port 13707, antenna 13708 or the like.The present invention can be applicable to the circuit in the display part 13703.Note, when display part 13703 on black background during the display white letter, the mobile phone power consumption is less.Further, according to the present invention, finish the mobile phone shown in Figure 32 H.
If can utilize later on from the higher brightness of the photon of luminous organic material emission, semiconductor devices so of the present invention can be applicable to front portion or rear-projected instrument, is amplified by lens or like comprising the light of output image data.
Above-mentioned electronic equipment is used for showing the data of being transmitted by telecommunication path such as Internet or CATV (cable television system) probably, in particular for showing the pictorial data of motion.Because luminescent material has high sensitivity,, luminaire shows so being applicable to active images.
In addition, because luminaire is in its luminous component consumed power, so expect the shared space of luminous component video data as small as possible.Therefore, use in the display part of main videotex data under the situation of luminaire, as mobile phone, sound reproducing equipment, expectation drives this equipment so that luminous component videotex data on non-emission background.
As mentioned above, range of application of the present invention is very wide, and the present invention can be applicable to the electronic equipment in various fields.Electronic equipment in the present embodiment can adopt the semiconductor devices with any structure as shown in the embodiment 1 to 6 of front.
The Japanese patent application sequence number no.2003-131824 that the application proposed in Jap.P. office based on May 9th, 2003, its content at this with for referencial use.
Though with the form of embodiment the present invention has been carried out comprehensive description with reference to the accompanying drawings, should be appreciated that those skilled in the art can very clearly carry out various conversion and modification.Therefore, unless this variation and modification break away from the scope of the present invention that is hereinafter limited, otherwise it should comprise in the present invention.
Claims (10)
1. semiconductor devices comprises:
Signal wire;
A plurality of element circuits respectively comprise switch and the transistor that can be connected with this signal wire by this switch; And
Electric supply installation, it is provided to first electric current transistor that is selected from M element circuit in these a plurality of element circuits between precharge phase, and second electric current is provided to the transistor that is selected from N element circuit in these a plurality of element circuits during setting,
Wherein, N and M are non-vanishing natural numbers, and
Wherein, M element circuit comprises N element circuit and the element circuit except N element circuit.
2. semiconductor devices comprises:
Signal wire;
A plurality of element circuits respectively comprise switch and the transistor that can be connected with this signal wire by this switch; And
Electric supply installation, it is provided to first electric current transistor that is selected from M element circuit in these a plurality of element circuits between precharge phase, and during setting, second electric current is provided to the transistor that is selected from N the element circuit except that this M element circuit in these a plurality of element circuits
Wherein, N and M are non-vanishing natural numbers.
3. according to the semiconductor devices of claim 1, N=1 wherein.
4. according to the semiconductor devices of claim 2, N=1 wherein.
5. according to the semiconductor devices of claim 1, wherein this element circuit comprises and is connected to this transistorized light-emitting component.
6. according to the semiconductor devices of claim 2, wherein this element circuit comprises and is connected to this transistorized light-emitting component.
7. according to the semiconductor devices of claim 1, wherein this first electric current is M: N with the size ratio of this second electric current.
8. according to the semiconductor devices of claim 2, wherein this first electric current is M: N with the size ratio of this second electric current.
9. the driving method of a semiconductor devices, this semiconductor devices comprises signal wire; A plurality of element circuits respectively comprise switch and the transistor that can be connected with this signal wire by this switch, and this method comprises:
First electric current is provided to the transistor that is selected from M element circuit in these a plurality of element circuits; And
Second electric current is provided to the transistor that is selected from N the element circuit except that this M element circuit in these a plurality of element circuits,
Wherein, N and M are non-vanishing natural numbers.
10. according to the driving method of the semiconductor devices of claim 9, wherein this first electric current and the size of this second electric current are than being M: N.
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| Application Number | Priority Date | Filing Date | Title |
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| CNB2004100639755A CN100541581C (en) | 2004-05-26 | 2004-05-26 | Semiconductor devices and driving method thereof |
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| CNB2004100639755A CN100541581C (en) | 2004-05-26 | 2004-05-26 | Semiconductor devices and driving method thereof |
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| CN1705003A CN1705003A (en) | 2005-12-07 |
| CN100541581C true CN100541581C (en) | 2009-09-16 |
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| CN106875899B (en) * | 2017-03-20 | 2019-07-26 | 联想(北京)有限公司 | A kind of control method and electronic equipment showing output device |
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