Source: https://patents.google.com/patent/CN101960509B/en
Timestamp: 2020-01-28 19:24:53
Document Index: 678611298

Matched Legal Cases: ['art 10', 'art 70', 'art 10', 'art 70', 'art 70', 'art 70', 'art 70', 'art 70', 'art 70', 'art 70', 'art 70', 'art 70', 'arts\n30']

CN101960509B - Display device and method for controlling the same - Google Patents
CN101960509B
CN101960509B CN200980100456.2A CN200980100456A CN101960509B CN 101960509 B CN101960509 B CN 101960509B CN 200980100456 A CN200980100456 A CN 200980100456A CN 101960509 B CN101960509 B CN 101960509B
CN200980100456.2A
CN101960509A (en
2008-07-04 Priority to JP176243/2008 priority Critical
2011-01-26 Publication of CN101960509A publication Critical patent/CN101960509A/en
2015-04-15 Publication of CN101960509B publication Critical patent/CN101960509B/en
A display device includes: an organic EL element (110); a capacitance element (150); a drive transistor (120) which applies current based on a voltage held in the capacitance element (150) connected to an anode of the organic EL element (110), to the organic EL element (110) so as to emit light; a data line (31) which supplies a signal voltage to the capacitance element (150); a switching transistor (130) which connects a data line (31) to the capacitance element (150); a voltage detection circuit (50) which is connected to the data line (31) and detects an anode voltage; an inspection transistor (140) which connects the anode to the data line (31); and a control unit which turns ON the switching transistor (130), causes the capacitance element (150) to hold a voltage corresponding to the signal voltage so that the organic EL element (110) emits light, and turns OFF the switching transistor (130) and turns ON the inspection transistor (140) while the organic EL element (110) is emitting light, and causes the voltage detection circuit (50) to detect an anode voltage.
The present invention relates to display device and control method thereof, particularly relate to the detection method that semiconductor drives the characteristic inequality of active component.
As the image display device employing current-driven light-emitting component, the known image display device (display of organic electroluminescence) being the use of organic electroluminescent device (OLED:Organic Light Emitting Diode: Organic Light Emitting Diode).The advantages such as it is good that this display of organic electroluminescence has viewing angle characteristic, and power consumption is few, as follow-on flat-panel monitor (FPD:Flat PanelDisplay) candidate and attract attention.
Usually, in display of organic electroluminescence, the organic electroluminescent device forming pixel is arranged to rectangular.The point of crossing of multiple column electrode (sweep trace) and multiple row electrode (data line) is provided with electro-luminescence element, the voltage being equivalent to data-signal is applied between selected column electrode and multiple row electrode, drive organic electroluminescent device with this, this is called as the display of organic electroluminescence of passive matrix type (passivematrix type).
On the other hand, the point of crossing of multiple sweep trace and multiple data line arranges thin film transistor (TFT) (TFT:Thin Film Transistor), this TFT is connected to the grid of driving transistors (drivingtransistor), this TFT conducting is made by selected sweep trace, from data line to driving transistors input data signal, drive organic electroluminescent device by this driving transistors, this is called as the display of organic electroluminescence of active matric (active matrix type).
With only during selecting each column electrode (sweep trace), the display of organic electroluminescence of the passive matrix type of connected organic electroluminescent device luminescence unlike, the display of organic electroluminescence of active matric can make organic electroluminescent device luminous to scanning next time (selection), even if so dutycycle rises, the brightness of display also can not be caused to reduce.Thus, can with low voltage drive, so low consumption electrification can be realized.But, in the display of organic electroluminescence of active matric, there is such shortcoming: because the skewness (dispersion) of the characteristic of driving transistors and organic electroluminescent device, even if supply identical data-signal, in each pixel, the brightness of organic electroluminescent device also can be different, occurred brightness spot (brightness disproportionation).
Deviation or the deterioration of the characteristic because of driving transistors and organic electroluminescent device in display of organic electroluminescence are in the past (following, be referred to as the heterogeneity of characteristic) and the compensation method of the brightness disproportionation caused, representative have: by the compensation of the image element circuit of complexity, by the feedback compensation etc. representing the feedback compensation of pixel and the summation by the electric current flowed in whole pixel.
But complicated image element circuit can reduce yield rate.And by representing the feedback of pixel and all can not being compensated the inequality of the characteristic of each pixel by the feedback of the summation of the electric current flowed in whole pixel.
Propose the several methods detected with the characteristic inequality of simple image element circuit to each pixel for the above reasons.
Such as, the substrate for luminescent panel disclosed in patent documentation 1, for inspection method and the luminescent panel of the substrate of luminescent panel, the voltage driven image element circuit be made up of two transistors is in the past connected to the transistor that diode connects, electroluminescence (EL) by being used as, under the state of the substrate for luminescent panel before electroluminescence is formed, the electric current flowed in the p-wire that the transistor of this diode connection is connected to can be determined at, and detect data voltage and relation between the electric current flowed in driving transistors, carry out pixel inspection and pixel characteristic extraction.And after this electroluminescence is formed, the transistor that diode connects also can use p-wire be formed as reverse biased and make electric current not flow, so can carry out common voltage write work.And the characteristic gone out with the state-detection of array, can be used for carrying out Corrective control to the applying voltage of data line during use organic electroluminescence panel.
Patent documentation 1: Japanese Unexamined Patent Publication 2006-139079 publication
But the drive current flowed within the pixel is very small, for the mensuration of Weak current, carry out accurately being very difficult via the p-wire etc. for measuring this electric current.
In the substrate for luminescent panel disclosed in patent documentation 1, the inspection method of the substrate for luminescent panel and luminescent panel, because use amperometric determination when the characteristic detecting driving transistors, so have the problem of the low precision of Characteristics Detection.In result, low to the precision of the detection of drive transistor characteristics inequality, the brightness disproportionation between pixel can not get correcting fully.
The driving transistors that each pixel has, is connected to total power supply and total electrode in luminescent panel.And the p-wire described in patent documentation 1 is also connected to total power supply and total electrode in luminescent panel.Why difficulty can enumerate following reason to Weak current described in high-precision measuring: because driving transistors is connected to total electrode and total power supply, is easily subject to the reason because measuring beyond pixel and the impact of noise that produces; And, be easily subject to because measuring load condition beyond pixel and the impact of voltage drop and impedance variation.
And that carries out the characteristic inequality of driving transistors with the mensuration based on Weak current described in patent documentation 1 is detected as representative, during beyond the display duration of work needing to arrange actual luminescent panel, perform this testing.So, such as, when need the characteristic of periodic detection driving transistors uneven because lasting change and upgrade to correct etc., likely make display duration of work restricted in order to this testing.
In view of described problem, the first object of the present invention is to provide a kind of display device and control method thereof, although this display device is simple image element circuit, can detect the electric current of the driving active component of each pixel with high-level efficiency and accurately.And other object is to provide a kind of method, it by using this current detecting result, thus detects the inequality of the characteristic of the driving active component of each pixel accurately.
In order to achieve the above object, the display device that a scheme of the present invention relates to, comprising: light-emitting component, first power lead, it is electrically connected with the first electrode of described light-emitting component, second source line, it is electrically connected with the second electrode of described light-emitting component, capacitor, it keeps voltage, driving transistors, it is arranged between described first electrode and described first power lead, and the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, thus makes described light-emitting component luminous, data line, it is to the electrode suppling signal voltage of a side of described capacitor, first on-off element, its voltage making described capacitor keep corresponding with described signal voltage, data line drive circuit, it is to described data line suppling signal voltage, voltage detecting circuit, it is connected to described data line, detects the voltage of described light-emitting component, second switch element, it makes described first electrode be connected with described data line with the tie point of described driving transistors, and control part, it is conducting state by making described first on-off element, make the voltage that described capacitor keeps corresponding with the signal voltage supplied by described data line, and by described driving transistors, the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, to make described light-emitting component luminous, and during described light-emitting component luminescence, be cut-off state by making described first on-off element, described second switch element is made to be conducting state, the current potential of described tie point is detected via described data line to make described voltage detecting circuit.
According to display device of the present invention and control method thereof, although be simple image element circuit, but but can measure the inspection voltage relevant with the characteristic of driving transistors at luminous duration of work, use this inspection voltage, can rapid, easy and electric current between the source drain detecting the driving transistors of each pixel accurately.And then, by detecting electric current between two not identical source drain, gain coefficient and the threshold voltage of described driving transistors can be calculated, thus the brightness disproportionation between the pixel that causes because of the inequality of this drive transistor characteristics can be corrected.
Fig. 1 is the block scheme of the electric structure representing the display device that embodiments of the invention 1 relate to.
Fig. 2 be represent the pixel portion that the display device that embodiments of the invention 1 relate to has circuit structure and and peripheral circuit between the figure of connection.
Fig. 3 is the figure of the first structure representing the voltage detection department that the display device that embodiments of the invention relate to has.
Fig. 4 is the figure of the second structure representing the voltage detection department that the display device that embodiments of the invention relate to has.
Fig. 5 is the figure of the 3rd structure representing the voltage detection department that the display device that embodiments of the invention relate to has.
Fig. 6 is the workflow diagram of the control method that the display device that embodiments of the invention relate to is described.
Fig. 7 is the workflow diagram of the bearing calibration that the control part that embodiments of the invention relate to is described.
Fig. 8 represents the supply timing of the signal voltage for detecting drive transistor characteristics that embodiments of the invention 1 relate to and checks the detection time diagram regularly of voltage.
Fig. 9 A is the circuit diagram of the duty of moment t1 ~ t2 that the display device that embodiments of the invention 1 relate to is described.
Fig. 9 B is the circuit diagram of the duty of moment t2 ~ t4 that the display device that embodiments of the invention 1 relate to is described.
Fig. 9 C is the circuit diagram of the duty of moment t4 ~ t6 that the display device that embodiments of the invention 1 relate to is described.
Figure 10 is the figure of an example of the voltage-current characteristic representing organic electroluminescent device.
Figure 11 be represent the pixel portion that the display device that embodiments of the invention 2 relate to has circuit structure and and peripheral circuit between the figure of connection.
Figure 12 represents the supply timing of the signal voltage for detecting drive transistor characteristics that embodiments of the invention 2 relate to and checks the detection time diagram regularly of voltage.
The outside drawing of the thin, planar televisor of Figure 13 display device of the present invention that has been built-in.
Display device in embodiment 1 comprises: light-emitting component, first power lead, it is electrically connected with the first electrode of described light-emitting component, second source line, it is electrically connected with the second electrode of described light-emitting component, capacitor, it keeps voltage, driving transistors, it is arranged between described first electrode and described first power lead, and the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, thus makes described light-emitting component luminous, data line, it is to the electrode suppling signal voltage of a side of described capacitor, first on-off element, its voltage making described capacitor keep corresponding with described signal voltage, data line drive circuit, it is to described data line suppling signal voltage, voltage detecting circuit, it is connected to described data line, detects the voltage of described light-emitting component, second switch element, it makes described first electrode be connected with described data line with the tie point of described driving transistors, and control part, it is conducting state by making described first on-off element, thus make the voltage that described capacitor keeps corresponding with the signal voltage supplied by described data line, by described driving transistors, the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, thus make described light-emitting component luminous, and during described light-emitting component luminescence, be cut-off state by making described first on-off element, described second switch element is made to be conducting state, thus make described voltage detecting circuit detect the current potential of described tie point via described data line.
According to this programme, to flow between described first power lead and described second source line making electric current thus during making described light-emitting component luminescence, make described voltage detecting circuit via described data line, detect the current potential of the first electrode of described light-emitting component and the tie point of described driving transistors.Accordingly, the signal voltage supplied by described data line when can be used in the luminescence of described light-emitting component, detects the current potential of the first electrode of described light-emitting component and the tie point of described driving transistors accurately.
If the current potential this detected is converted to electric current, then the electric current after this conversion, according to the annexation of described light-emitting component and described driving transistors, electric current between the source drain becoming described driving transistors.Therefore, do not need the special voltage input using the current potential of the tie point for the first electrode and described driving transistors detecting described light-emitting component, and by be used in described light-emitting component luminous time the signal voltage supplied by described data line, just can easy and electric current between the source drain calculating described driving transistors accurately.
Display device in embodiment 2 is: in the display device in embodiment 1, also comprises conversion portion, its current potential of described tie point will detected by described voltage detecting circuit, is scaled the electric current flowed between the source drain of described driving transistors.
According to this programme, be provided with conversion portion, it, by the current potential of the first electrode of described light-emitting component of being detected by described voltage detecting circuit and the tie point of described driving transistors, is scaled the electric current flowed between the source drain of described driving transistors.Accordingly, the described current potential detected is converted to electric current.Electric current after this conversion, according to the annexation of described light-emitting component and described driving transistors, electric current between the source drain becoming described driving transistors.Therefore, do not need the special voltage input using the current potential of the tie point for the first electrode and described driving transistors detecting described light-emitting component, and by utilizing the signal voltage supplied by described data line when described light-emitting component is luminous, just can easy and electric current between the source drain calculating described driving transistors accurately.
Display device in embodiment 3 is: in the display device in embodiment 2, also comprise storer, it stores the data corresponding with the voltage-current characteristic of described light-emitting component, described conversion portion, the data corresponding with the voltage-current characteristic of described light-emitting component stored according to described storer, by the current potential of described tie point detected by described voltage detecting circuit, be scaled the electric current flowed between the source drain of described driving transistors.
According to this programme, the display device of this programme is also provided with storer, and it stores the data corresponding with the voltage-current characteristic of described light-emitting component.Accordingly, according to the data corresponding with the voltage-current characteristic of described light-emitting component prestored, and the current potential of the first electrode of described light-emitting component to be detected by described voltage detecting circuit and the tie point of described driving transistors, calculate the electric current flowing to described light-emitting component.Therefore, electric current between the source drain calculating the driving transistors equal with this electric current.Its result, can according to the current potential detected by described voltage detecting circuit, electric current between the source drain calculating rapidly driving transistors.
Display device in embodiment 4 is: in the display device in embodiment 3, described light-emitting component, described capacitor and described driving transistors form pixel portion, and the data corresponding with the voltage-current characteristic of described light-emitting component are data of the voltage-current characteristic of the light-emitting component in described pixel portion.
According to this programme, the data corresponding with the voltage-current characteristic of described light-emitting component can be the data of the voltage-current characteristic of the light-emitting component in described pixel portion.
Display device in embodiment 5 is: in the display device in embodiment 3, there is multiple pixel portion be made up of described light-emitting component, described capacitor and described driving transistors, and the data corresponding with the voltage-current characteristic of described light-emitting component are data of the voltage-current characteristic of the light-emitting component representing multiple described pixel portion.
According to this programme, the data corresponding with the voltage-current characteristic of described light-emitting component can be the data of the voltage-current characteristic of the light-emitting component representing multiple described pixel portion.
Display device in embodiment 6 is: in the display device in embodiment 3, described light-emitting component, described capacitor and described driving transistors form pixel portion, and described display device comprises luminescent panel, this luminescent panel has multiple described pixel portions and multiple data line, the plurality of data line is connected with described multiple pixel portion respectively, described voltage detecting circuit comprises: more than one voltage-level detector, it, via the more than one data line selected from described multiple data line, detects the current potential of described tie point; And multiplexer, it is connected between described multiple data line and described more than one voltage-level detector, make described by the more than one data line selected and described more than one voltage-level detector conducting, described in the number ratio of described more than one voltage detecting circuit, the number of multiple data line is few.
According to this programme, described in the number ratio of described more than one voltage detecting circuit, the number of multiple data line is few.Accordingly, because the current potential of tie point of the first electrode and described driving transistors in order to detect described light-emitting component can be cut down and the quantity of required voltage detecting circuit, so the area savingization of display device and the reduction of element number can be realized.
Display device in embodiment 7 is: in the display device in embodiment 6, and described multiplexer is formed on described luminescent panel.
According to this programme, described multiplexer can be formed on described luminescent panel.In this situation, the scale of voltage detecting circuit is reduced, so can realize low cost.
Display device in embodiment 8 is: in the display device in embodiment 1, described first electrode is the anode electrode of described light-emitting component, described in the voltage ratio of described first power lead, the voltage of second source line is high, and electric current flows to described second source line from described first power lead.
According to this programme, the first electrode of described light-emitting component is the anode electrode of described light-emitting component, and described in the voltage ratio of described first power lead, the voltage of second source line is high, and electric current flows to described second source line from described first power lead.
The control method of the display device in embodiment 9 is the control method of the display device possessing following parts: light-emitting component, first power lead, it is electrically connected with the first electrode of described light-emitting component, second source line, it is electrically connected with the second electrode of described light-emitting component, capacitor, it keeps voltage, driving transistors, it is arranged between described first electrode and described first power lead, and the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, makes described light-emitting component luminous, data line, it is to the electrode suppling signal voltage of a side of described capacitor, first on-off element, its voltage making described capacitor keep corresponding with described signal voltage, data line drive circuit, it is to described data line suppling signal voltage, voltage detecting circuit, it is connected to described data line, detects the voltage of described light-emitting component, and second switch element, it makes described first electrode be connected with described data line with the tie point of described driving transistors, the control method of described display device: be conducting state by making described first on-off element, with the voltage making described capacitor keep corresponding with the first signal voltage supplied by described data line, by described driving transistors, the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, make described light-emitting component luminous, and during described light-emitting component luminescence, by making described first on-off element cut-off, described second switch element is made to be conducting state, thus make described voltage detecting circuit detect the first current potential of described tie point via described data line.
According to this programme, during light-emitting component luminescence described in the chien shih flowing to described first power lead and described second source line making electric current, make described voltage detecting circuit via described data line, detect the current potential of the first electrode of described light-emitting component and the tie point of described driving transistors.Accordingly, the signal voltage supplied by described data line when being used in the luminescence of described light-emitting component, can detect the current potential of the first electrode of described light-emitting component and the tie point of described driving transistors accurately.When the current potential this detected is converted to electric current, then the electric current after this conversion, by the annexation of described light-emitting component and described driving transistors, electric current between the source drain becoming described driving transistors.Therefore, do not need the special voltage input using the current potential of the tie point for the first electrode and described driving transistors detecting described light-emitting component, and by be used in described light-emitting component luminous time the signal voltage supplied by described data line, just can easy and electric current between the source drain calculating described driving transistors accurately.
The control method of the display device in embodiment 10 is: in the control method of the display device in embodiment 9, by the first current potential of described tie point be detected, is scaled the first electric current flowed between the source drain of described driving transistors.
According to this programme, be provided with conversion portion, it, by the current potential of the first electrode of described light-emitting component of being detected by described voltage detecting circuit and the tie point of described driving transistors, is scaled the electric current flowed between the source drain of described driving transistors.Accordingly, the described current potential detected is converted to electric current.Electric current after this conversion, according to the annexation of described light-emitting component and described driving transistors, electric current between the source drain becoming described driving transistors.Therefore, do not need the special voltage input using the current potential of the tie point for the first electrode and described driving transistors detecting described light-emitting component, and by be used in described light-emitting component luminous time the signal voltage supplied by described data line, just can easy and electric current between the source drain calculating described driving transistors accurately.
The control method of the display device in embodiment 11 is: in the control method of the display device in embodiment 10, described display device comprises storer, it stores the data corresponding with the voltage-current characteristic of described light-emitting component, the data corresponding with the voltage-current characteristic of described light-emitting component that the control method of this display device stores according to described storer, by the first current potential of the described described tie point detected, be scaled the first electric current flowed between the source drain of described driving transistors.
According to this programme, be provided with storer, it stores the data corresponding with the voltage-current characteristic of described light-emitting component.Accordingly, according to the data corresponding with the voltage-current characteristic of described light-emitting component prestored, and the current potential of the first electrode of described light-emitting component to be detected by described voltage detecting circuit and the tie point of described driving transistors, calculate the electric current flowing to described light-emitting component.Therefore, electric current between the source drain calculating the driving transistors equal with this electric current.Its result, can according to the current potential detected by described voltage detecting circuit, electric current between the source drain calculating rapidly driving transistors.
The control method of the display device in embodiment 12 is: in the control method of the display device in embodiment 10, be conducting state further by making described first on-off element, make the voltage that described capacitor keeps corresponding with the secondary signal voltage supplied by described data line, and by described driving transistors, the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, make described light-emitting component luminous, and during described light-emitting component luminescence, be cut-off state by making described first on-off element, described second switch element is made to be conducting state, thus make described voltage detecting circuit detect the second current potential of described tie point via described data line and described wiring, and by the second current potential of the described described tie point detected, be scaled the second electric current flowed between the source drain of described driving transistors, and according to described first current potential, described second current potential, described first electric current and described second electric current, calculate the gain coefficient of described driving transistors and described threshold voltage.
According to this programme, two when working by using the luminescence of common light-emitting component different signal voltages, can detect electric current between two of the driving transistors corresponding from each signal voltage different source drain.That is, use described first current potential, described second current potential, described first electric current and described second electric current, calculate the gain coefficient of described driving transistors and described threshold voltage.Therefore, if calculate the gain coefficient of described driving transistors and described threshold voltage, then just can be easy and promptly calculate the gain coefficient of the described driving transistors between multiple pixel and the inequality of described threshold voltage.Its result, can correct accurately to the brightness disproportionation caused because of the gain coefficient of the described driving transistors between multiple pixel and the inequality of described threshold voltage.
The control method of the display device in embodiment 13 is: in the control method of the display device in embodiment 12, described display device comprises storer, it stores the data corresponding with the voltage-current characteristic of described light-emitting component, the data corresponding with the voltage-current characteristic of described light-emitting component that the control method of this display device stores according to described storer, are scaled described first electric current and described second electric current respectively by described first current potential and described second current potential.
According to this programme, according to the data corresponding with the voltage-current characteristic of described light-emitting component prestored, and the current potential of the second electrode of described light-emitting component to be detected by described voltage detecting circuit and the tie point of described driving transistors, calculate the electric current flowing to described light-emitting component.Therefore, electric current between the source drain just having calculated the driving transistors equal with this electric current.Its result, can according to the current potential detected by described voltage detecting circuit, electric current between the source drain promptly calculating driving transistors.
The control method of the display device in embodiment 14 is: in the control method in embodiment 12, by deducting from described first signal voltage the supply voltage be set on described first power lead, the voltage obtained is set to Vgs1, described first power lead is be connected to the source electrode of described driving transistors and the side in draining, the voltage obtained deducting described supply voltage from described secondary signal voltage is set to Vgs2, described first electric current is set to I1, described second electric current is set to I2, by the channel region with described driving transistors, oxide film electric capacity and be set to β about the gain function of mobility, and when the threshold voltage of described driving transistors is set to Vth, use following relational expression,
&beta; = ( 2 I 1 - 2 I 2 V gs 1 - V gs 2 ) 2
Vth = V gs 2 &times; 2 I 1 - V gs 1 &times; 2 I 2 2 I 1 - 2 I 2
Calculate the gain coefficient of described driving transistors and described threshold voltage.
According to this programme, by use by described light-emitting component luminescence work time supply the first signal voltage and secondary signal voltage detected by the first current potential of described tie point and the second current potential of described tie point, the gain coefficient of described driving transistors and described threshold voltage can be calculated, so can be easy and promptly calculate the gain coefficient of the described driving transistors between multiple pixel and the inequality of described threshold voltage.Its result, can correct accurately to the brightness disproportionation caused because of the gain coefficient of the described driving transistors between multiple pixel and the heterogeneity of described threshold voltage.
Display device in embodiment 15, comprising: light-emitting component, first power lead, it is electrically connected with the first electrode of described light-emitting component, second source line, it is electrically connected with the second electrode of described light-emitting component, capacitor, it keeps voltage, driving transistors, it is arranged between described first electrode and described first power lead, and the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, makes described light-emitting component luminous, data line, it is to the electrode suppling signal voltage of a side of described capacitor, first on-off element, its voltage making described capacitor keep corresponding with described signal voltage, data line drive circuit, it is to described data line suppling signal voltage, sense wire, it reads the voltage of described light-emitting component, voltage detecting circuit, it is connected to described sense wire, detects the voltage of described light-emitting component, second switch element, it makes described first electrode be connected with described sense wire with the tie point of described driving transistors, and control part, it is conducting state by making described first on-off element, make the voltage that described capacitor keeps corresponding with the signal voltage supplied by described data line, by described driving transistors, the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, make described light-emitting component luminous, and during described light-emitting component luminescence, be cut-off state by making described first on-off element, be conducting state by making described second switch element, the current potential detecting described tie point is made it via described sense wire.
According to this programme, during light-emitting component luminescence described in the chien shih flowing to described first power lead and described second source line making electric current, make described voltage detecting circuit via described data line, detect the current potential of the first electrode of described light-emitting component and the tie point of described driving transistors.Accordingly, the signal voltage supplied by described data line when being used in the luminescence of described light-emitting component, can detect the current potential of the first electrode of described light-emitting component and the tie point of described driving transistors accurately.
And, make described voltage detecting circuit, via the sense wire different from described data line, detect the voltage of described light-emitting component.Accordingly, because described voltage detecting circuit, via the sense wire be not connected with basic circuit to detect the voltage of described light-emitting component, so by the impact of the caused voltage drop of the first on-off element etc. as the inscape of basic circuit, the voltage of described light-emitting component more precisely can be measured.
Below, with reference to the accompanying drawings the preferred embodiments of the present invention are described.In addition, in institute's drawings attached below, same symbol is enclosed for identical or suitable key element, the explanation repeated is omitted.
Below, utilize accompanying drawing to specifically describe embodiments of the invention.
Fig. 1 is the block scheme of the electric structure representing the display device that embodiments of the invention 1 relate to.The display device 1 of this figure comprises: display part 10, scan line drive circuit 20, data line drive circuit 30, voltage detecting circuit 50, multiplexer 60, control part 70, storer 80.
Fig. 2 be represent the pixel portion that the display device that embodiments of the invention 1 relate to has circuit structure and and peripheral circuit between the figure of connection.The pixel portion 100 of this figure comprises: organic electroluminescent device 110, driving transistors 120, switching transistor 130, inspection transistor 140, capacity cell 150, total electrode 115, power lead 125, sweep trace 21, control line 22, data line 31.And peripheral circuit comprises: scan line drive circuit 20, data line drive circuit 30, voltage detecting circuit 50, multiplexer 60.
First, its function is illustrated to the inscape that Fig. 1 records.
Display part 10 is the display panels comprising multiple pixel portion 100.
Scan line drive circuit 20 is connected with sweep trace 21 and control line 22, and it has the conducting of the switching transistor 130 and inspection transistor 140 controlling pixel portion 100 and non-conduction function respectively.
Data line drive circuit 30 has the function to data line 31 suppling signal voltage.And data line drive circuit 30, by making internal driving change or using built-in switch, can make and the connection disconnection of data line 31 or short circuit.
Data line 31 is connected with the pixel column comprising pixel portion 100, and the signal voltage exported from data line drive circuit 30 is fed to each pixel portion of this pixel column by it.
Voltage detecting circuit 50 plays function as voltage detection department together with multiplexer 60, and is connected to data line 31 via multiplexer 60, and it has by checking that transistor 140 conducting detects the function of the anode voltage of organic electroluminescent device 110.According to the grid voltage of the driving transistors 120 charged by capacity cell 150, detected anode voltage is equal with the drain voltage that the drain current by driving transistors 120 produces.
Multiplexer 60 has conducting to voltage detecting circuit 50 and data line 31 and the non-conduction function switched, and this data line 31 is connected on voltage detecting circuit 50.
In addition, voltage detecting circuit 50, can be built in data driver integrated circuit 30, also can separately be located at outside data driver integrated circuit together with data line drive circuit 30.
Fig. 3 is the figure of the first structure representing the voltage detection department that the display device that embodiments of the invention relate to has.As this figure records, voltage detecting circuit 50 can have the quantity voltage-level detector identical with the number of data line 31 51.And in this situation, each voltage-level detector 51 is connected to each data line 31 via multiplexer 60.
On the other hand, Fig. 4 is the figure of the second structure representing the voltage detection department that the display device that embodiments of the invention relate to has.As this figure records, voltage detecting circuit 50 preferably has the few voltage-level detector 51 of the number of the multiplexer 60 of the switching carrying out data line 31 and number ratio data line 31.Accordingly, the quantity of the voltage-level detector 51 required when measuring the anode voltage of organic electroluminescent device 110 can be cut down, so the area savingization of electronic installation and the reduction of element number can be realized.In this situation, multiplexer 60 also can in the outside of crossing detector circuit 50.
And Fig. 5 is the figure of the 3rd structure representing the voltage detection department that the display device that embodiments of the invention relate to has.As this figure records, when voltage detecting circuit 50 has voltage-level detector 51 of the multiplexer 60 of the switching carrying out data line 31 and the quantity fewer than the number of data line 31, multiplexer 60 can be formed on luminescent panel 5.Low cost like this, reduces the scale of voltage detecting circuit, so can be realized.In this case, multiplexer 60 also can be arranged on the outside of voltage detecting circuit 50.
Again its function is illustrated to the inscape that Fig. 1 records.
Control part 70 comprises voltage control division 701 and conversion portion 702.
Voltage control division 701, control scan line drive circuit 20, data line drive circuit 30, voltage detecting circuit 50, multiplexer 60 and storer 80, it has the function making voltage detecting circuit 50 detect the anode voltage of organic electroluminescent device 110.
Conversion portion 702, by the anode voltage of organic electroluminescent device 110 detected by voltage detecting circuit 50, according to the voltage-current characteristic data of the organic electroluminescent device be stored in advance in storer 80, be scaled the current value flowing to organic electroluminescent device 110.And then conversion portion 702, uses the current value flowing to organic electroluminescent device 110 changed, according to computing described later, calculates gain coefficient and the threshold voltage of driving transistors 120.Further, the gain coefficient in each pixel portion calculated and threshold voltage, be written to storer 80 by conversion portion 702.
And then, in the display work in each pixel portion after described gain coefficient and threshold voltage are written to storer 80, control part 70 reads this gain coefficient and threshold voltage, according to the image signal data that this gain coefficient and threshold voltage correction input from outside, and output to data line drive circuit 30.
Storer 80, is connected to control part 70, which stores the voltage-current characteristic data of organic electroluminescent device.According to the voltage-current characteristic data that this stores, and the anode voltage of the organic electroluminescent device 110 measured, calculate the electric current flowing to organic electroluminescent device 110, and between the source drain of the driving transistors equal with this electric current, electric current is calculated rapidly.
In addition, be stored in the voltage-current characteristic data in storer 80 in advance, can be the voltage-current characteristic data of the organic electroluminescent device representing luminescent panel, or, also can be the data of the voltage-current characteristic of the organic electroluminescent device 110 that each pixel portion has.Accordingly, electric current between the source drain calculating driving transistors 120 accurately.
And the above-mentioned voltage-current characteristic being stored in advance in the organic electroluminescent device in storer 80, can be updated termly or together be updated along with the change that lasts of the characteristic of organic electroluminescent device 110.
Secondly, Fig. 2 is utilized to carry out the internal circuit configuration in pixels illustrated portion 100.
Organic electroluminescent device 110, play function as light-emitting component, it carries out the luminescence work corresponding with electric current between the source drain supplied from driving transistors 120.As the negative electrode of the opposing party's terminal of organic electroluminescent device 110, be connected to total electrode 115, be generally ground connection.
Driving transistors 120, its grid is connected to data line 31 via switching transistor 130, and source electrode and the side in draining are connected to power lead 125, and source electrode and the opposing party in draining are connected to the anode of the terminal of the side as organic electroluminescent device 110.In addition, power lead 125 is connected to the power supply as constant voltage Vdd.
Connect according to described circuit, from the signal voltage that data line drive circuit 30 exports, be applied to the grid of driving transistors 120 via data line 31 and switching transistor 130.Electric current between the source drain corresponding with the described signal voltage of the grid being applied to driving transistors 120, the anode via organic electroluminescent device 110 flows to organic electroluminescent device 110.
Switching transistor 130, function is played as the first on-off element, the grid of switching transistor 130 is connected with sweep trace 21, source electrode and the side in draining are connected with data line 31, the Electrode connection of source electrode and the opposing party in draining and the grid of driving transistors 120 and a side of capacity cell 150.Namely, high level is become by the voltage level of sweep trace 21, thus switching transistor 130 becomes conducting (ON) state, described signal voltage is applied to the grid of driving transistors 120, makes the voltage that capacity cell 150 keeps corresponding with described signal voltage simultaneously.
Check transistor 140, function is played as second switch element, check that the grid of transistor 140 is connected to control line 22, source electrode and the side in draining are connected to the anode of the terminal of the side as organic electroluminescent device 110, and source electrode and the opposing party in draining are connected to data line 31.Namely, become high level by the voltage level of control line 22, thus check that transistor 140 becomes conducting state, be tested with the anode voltage of electro-luminescence element 110 by voltage detecting circuit 50 via data line 31.
Capacity cell 150 is the capacitors keeping voltage, and the connecting terminals of its side is connected to the grid of driving transistors 120, and the connecting terminals of opposite side is connected to the source electrode of driving transistors 120 and the side in draining.The signal voltage of the grid being fed to driving transistors 120 is maintained by this capacity cell 150, so between the source drain corresponding with this signal voltage during current flowing, usage data line 31, inspection transistor 140 and voltage detecting circuit 50, can be tested with the anode voltage of electro-luminescence element 110.
According to foregoing circuit structure, the signal voltage supplied by data line drive circuit when being used in common luminescence work, can measure the voltage of the anode of the organic electroluminescent device of the tie point as driving transistors 120 and organic electroluminescent device 110 accurately.According to conversion method described later, the anode voltage of the described organic electroluminescent device measured, can be scaled the electric current flowing to this organic electroluminescent device.This is by the electric current converted, according to the annexation of described organic electroluminescent device and described driving transistors, equal with electric current between the source drain of described driving transistors.Therefore, for the anode voltage of described organic electroluminescent device, do not need the special input voltage prepared in addition for measuring this voltage, and by using signal voltage during luminous work usually, just can easy and electric current between the source drain calculating described driving transistors accurately.
Below, the control method of the display device that embodiments of the invention relate to is described.
First, voltage control division 701, writes the first signal voltage exported from data line drive circuit 30 to capacity cell 150, makes driving transistors 120 export the first electric current (S10) corresponding with the first signal voltage.
Secondly, voltage control division 701 makes voltage detecting circuit 50 detect the anode voltage (S11) of the organic electroluminescent device 110 when having supplied the first signal voltage.
Secondly, voltage control division 701 writes the secondary signal voltage different from the first signal voltage exported from data line drive circuit 30 to capacity cell 150, makes driving transistors 120 export the second electric current (S12) corresponding with secondary signal voltage.
Secondly, voltage control division 701 makes voltage detecting circuit 50 detect the anode voltage (S13) of the organic electroluminescent device 110 when having supplied secondary signal voltage.
Secondly, conversion portion 702, according to be written in step S10 and step S12 the first signal voltage of capacity cell 150 and secondary signal voltage, obtain in step S11 and step S13 first check that voltage and second checks voltage and is stored in advance in the voltage-current characteristic data of organic electroluminescent device of storer 80, calculate the gain coefficient of driving transistors 120 and threshold voltage and be stored into (S14) in storer 80.About the described gain coefficient of driving transistors 120 and the computing method of threshold voltage, describe below.
Finally, control part 70 reads the gain coefficient and threshold voltage that calculate from storer 80, inputted picture signal carried out correcting (S15) as data voltage.
About the work of the control part 70 in step S15, perform such as following work.
First, control part 70 according to the synchronizing signal be transfused to the picture signal inputted from outside simultaneously, by the positional information (S151) of each this picture signal of pixel detection.
Secondly, control part 70, with reference to storer 80, reads gain coefficient and the threshold voltage (S152) of each pixel.
Secondly, control part 70, is converted to the data voltage (S153) corrected according to gain coefficient and threshold voltage by the luminance signal corresponding with picture signal.
Finally, control part 70, outputs to data line drive circuit 30 by calibrated data voltage, is fed to specifically (S154) as calibrated data voltage.
Secondly, Fig. 8 and Fig. 9 A ~ Fig. 9 C is used the supply timing of the electric signal of step S10 and the step S11 performed in the workflow diagram recorded at Fig. 6 to be described and to detect timing.
Fig. 8 represents the supply timing of the signal voltage for detecting drive transistor characteristics that embodiments of the invention 1 relate to and checks the detection time diagram regularly of voltage.In the figure, horizontal axis representing time.And on longitudinal direction, show following oscillogram by order from top to bottom: the oscillogram of the oscillogram of the voltage produced on sweep trace 21, the oscillogram of voltage that control line 22 produces and the voltage of data line 31.
First, at moment t0, data line drive circuit 30 exports the first signal voltage to data line 31.
Secondly, at moment t1, the voltage level of sweep trace 21 becomes high level, and switching transistor 130 becomes conducting state, thus performs the write of the applying to the first signal voltage of the grid of driving transistors 120 and the first signal voltage to capacity cell 150.
And the first signal voltage and secondary signal voltage are the data voltages used in the display work of reality, at moment t1, driving transistors 120 makes the electric current corresponding with the first signal voltage flow to organic electroluminescent device 110.Like this, organic electroluminescent device 110 starts luminous work.
Secondly, at moment t2, the voltage level of sweep trace 21 becomes low level, and switching transistor 130 becomes cut-off (OFF) state, thus the applying terminated to the first signal voltage of the grid of driving transistors 120 and the first signal voltage write to capacity cell 150.Now, driving transistors 120 makes the electric current corresponding with the first signal voltage that capacity cell 150 keeps continue to flow to organic electroluminescent device 110.Like this, organic electroluminescent device 110 continues to perform luminous work.
Secondly, at moment t3, stop from data line drive circuit 30 to the output of the first signal voltage of data line 31, become high impedance by data line drive circuit 30, thus data line drive circuit 30 and data line 31 be connected to become off-state.
Secondly, at moment t4, the voltage level of control line 22 becomes high level, checks that transistor 140 becomes conducting state, thus the anode of organic electroluminescent device 110 and data line 31 conducting.
Secondly, at moment t5, under the state that organic electroluminescent device 110 continues luminous work, voltage detecting circuit 50 detects the voltage of data line 31, thus is tested with the anode voltage of electro-luminescence element 110.
Finally, at moment t6, the voltage level of control line 22 becomes low level, checks that transistor 140 becomes cut-off state, thus terminates a series of work.
In addition, above-mentioned time diagram, by the first signal voltage is replaced into secondary signal voltage, is also applicable to the supply timing of the electric signal in the step S12 and step S13 performed in the workflow diagram recorded at Fig. 6 and detects timing.
The time diagram that each step recorded according to Fig. 6 and Fig. 8 record, for two of determined organic electroluminescent device 110 different anode voltages, signal voltages different from two of data line drive circuit 30 supply when luminescence works usually can be used, measure accurately.And, the anode voltage that two of the organic electroluminescent device 110 measured are different, can according to the voltage-current characteristic of the aforesaid organic electroluminescent device be stored in advance in storer 80, be converted into the electric current that two of flowing to organic electroluminescent device 110 are different.Further, according to the annexation between organic electroluminescent device 110 and driving transistors 120, between the source drain of these two kinds of electric currents and driving transistors 120, electric current is equal.Thus, for the anode voltage of organic electroluminescent device 110, do not need the special voltage input performed in addition for measuring this voltage, and by the different signal voltage of two when using usually luminous work, just can the easy and electric current that between the source drain calculating driving transistors 120 accurately two are different.
Secondly, illustrate and calculate the gain coefficient of driving transistors 120 and the method for threshold voltage in the step S14 performed in the workflow diagram recorded at Fig. 6.Namely, the method for electric current between the source drain being scaled driving transistors 120 from the anode voltage of the organic electroluminescent device 110 detected is described and utilizes between above-mentioned two different signal voltages and the source drain different from two of its corresponding driving transistors 120 electric current to the method for the gain coefficient and threshold voltage that calculate driving transistors 120.
First, the signal voltage being written to capacity cell 150 is being set to V det, the supply voltage of the source terminal being applied to driving transistors 120 is set to V dd, and electric current between the source drain of driving transistors 120 is set to I testtime, following formula 1 is set up.
I test=(β/2) (V det-V dd-Vth) 2(formula 1)
At this, β is the gain coefficient relevant with the channel region of driving transistors 120, oxide film electric capacity and mobility, and Vth is the threshold voltage of driving transistors 120, and it is relevant with mobility.
At this, between the source drain of driving transistors 120, electric current can be obtained according to the voltage-current characteristic of the anode voltage of organic electroluminescent device 110 and organic electroluminescent device 110.
Figure 10 is the figure of an example of the voltage-current characteristic representing organic electroluminescent device.The transverse axis of this figure represents the voltage between the anode-negative pole being applied to organic electroluminescent device, and the longitudinal axis represents the electric current flowing to organic electroluminescent device.The voltage-current characteristic of this organic electroluminescent device, such as, is stored in advance in storer 80.Be stored in the voltage-current characteristic data in storer 80, preferably represent the voltage-current characteristic data of the organic electroluminescent device of luminescent panel.
At the moment t5 of aforesaid Fig. 8, according to the anode voltage of the organic electroluminescent device 110 detected and the voltage-current characteristic of organic electroluminescent device recorded from Figure 10 that storer 80 is read out, converse the electric current flowing to organic electroluminescent device 110.This is by the electric current converted, equal with electric current between the source drain flowing to driving transistors 120.As above-mentioned, according to the anode voltage of organic electroluminescent device 110, electric current I between the source drain conversing driving transistors 120 test.
Secondly, according to formula 1, the two kinds of signal voltage V varied in size will supplied det1, V det2time driving transistors 120 source drain between electric current be set to I 1and I 2time, following simultaneous equations can be obtained.
I 1=(β/2) (V det1-V dd-Vth) 2(formula 2)
I 2=(β/2) (V det2-V dd-Vth) 2(formula 3)
At this, if Vgs1=V det1-V dd, V gs2=V det2-V ddif separate this simultaneous equations, then β and Vth is as follows respectively.
Like this, the first signal voltage Vgs1 and secondary signal voltage Vgs2 is supplied to capacity cell 150, by the anode voltage of organic electroluminescent device 110 that measured by them by the first electric current I converted 1and second electric current I 2, gain coefficient and the threshold voltage of driving transistors 120 can be calculated.
In addition, the first signal voltage and secondary signal voltage can be detected in data line 31, such as, can be detected by voltage detecting circuit 50.
Described characterisitic parameter, because the manufacture of driving transistors is unequal, sometimes has not identical value between pixel.Gain coefficient and the threshold voltage in each pixel portion obtained according to above-mentioned calculation method are stored in advance in storer 80 etc., by reading gain coefficient and the threshold voltage in each pixel portion from storer 80 when luminescence afterwards works, thus image signal data is corrected, the brightness disproportionation caused by characteristic inequality of the driving transistors between pixel can be improved.
In addition, the voltage-current characteristic data of the organic electroluminescent device stored in storer 80, multiple following data can be stored: the voltage-current characteristic data of the organic electroluminescent device 110 that each pixel portion has, or, the voltage-current characteristic data of the organic electroluminescent device of each piece in units of multiple pixel portion.Like this, electric current between the source drain that more precisely can calculate driving transistors 120.According to above-mentioned embodiments of the invention, although be simple image element circuit, the inspection voltage relevant with the characteristic of driving transistors can be detected accurately in luminescence work.And the voltage-current characteristic of light-emitting component utilizing described inspection voltage and prestore, can rapid, easy and electric current between the source drain calculating the driving transistors of each pixel accurately.And then, by electric current between the source drain that calculates described in using, the characterisitic parameter of the driving transistors in each pixel portion can be calculated.Utilize this characterisitic parameter, the brightness disproportionation between the pixel caused by characteristic inequality that can correct described driving transistors.
Figure 11 be represent the pixel portion that the display device that embodiments of the invention 2 relate to has circuit structure and and peripheral circuit between the figure of connection.The pixel portion 101 of this figure comprises: organic electroluminescent device 110, driving transistors 120, switching transistor 130, inspection transistor 160, capacity cell 150, total electrode 115, power lead 125, sweep trace 21, control line 22, data line 31 and sense wire 53.And peripheral circuit comprises: scan line drive circuit 20, data line drive circuit 30, voltage detecting circuit 50, multiplexer 60 and voltage-selected switch 65.Display device in embodiments of the invention 2 is compared with the display device in embodiment 1, difference is: be provided with sense wire 53 at each pixel column, and being provided with voltage-selected switch 65, this voltage-selected switch 65 is for selecting sense wire 53 and any one in the connection of data line drive circuit 30 or the connection of data line 31 and data line drive circuit 30.And pixel portion 101 is compared with pixel portion 100, and difference is: check that transistor 160 is not be connected to data line 31 but be connected to sense wire 53.Below, the part identical with embodiment 1 omits the description, and is described centered by different parts.
Scan line drive circuit 20 is connected to sweep trace 21 and control line 22, and it has the conducting of the switching transistor 130 and inspection transistor 160 controlling pixel portion 101 respectively and non-conduction function.
Data line drive circuit 30 has the function to data line 31 suppling signal voltage.And data line drive circuit 30 utilizes voltage-selected switch 65, can make and the connection disconnection of data line 31 or short circuit.
Voltage detecting circuit 50 plays function as voltage detection department together with multiplexer 60, voltage detecting circuit 50 is connected to sense wire 53 via multiplexer 60, and it has by checking that the conducting of transistor 160 detects the function of the anode voltage of organic electroluminescent device 110.The anode voltage be detected is according to the grid voltage of the driving transistors 120 charged by capacity cell 150, equal with the drain voltage that the drain current by driving transistors 120 produces.
Multiplexer 60 has conducting to voltage detecting circuit 50 and sense wire 53 and the non-conduction function switched, and this sense wire 53 is connected to voltage detecting circuit 50.
Check that transistor 160 plays function as second switch element, check that the grid of transistor 160 is connected to control line 22, source electrode and the side in draining are connected to the anode of a terminal as organic electroluminescent device 110, and source electrode and the opposing party in draining are connected to sense wire 53.Namely, become high level by the voltage level of control line 22, thus check that transistor 160 becomes conducting state, be tested with the anode voltage of electro-luminescence element 110 by voltage detecting circuit 50 via sense wire 53.
Capacity cell 150 is the capacitors keeping voltage, and a connecting terminals of capacity cell is connected to the grid of driving transistors 120, and another connecting terminals is connected to the source electrode of driving transistors 120 and the side in draining.This capacity cell 150 is utilized to keep the signal voltage of the grid being fed to driving transistors 120, so between the source drain corresponding with this signal voltage during current flowing, use sense wire 53, check that transistor 160 and voltage detecting circuit 50 can be tested with the anode voltage of electro-luminescence element 110.
According to foregoing circuit structure, the signal voltage from data line drive circuit supply when common luminescence work can be utilized, measure the voltage of the anode of the organic electroluminescent device of the tie point as driving transistors 120 and organic electroluminescent device 110 accurately.The anode voltage of the described organic electroluminescent device measured, can be scaled the electric current flowing to this organic electroluminescent device according to conversion method described later.This is by the electric current converted, according to the annexation of described organic electroluminescent device and described driving transistors, equal with electric current between the source drain of described driving transistors.Therefore, for the anode voltage of described organic electroluminescent device, do not need the special input voltage prepared in addition for measuring this voltage, and by using signal voltage during luminous work usually, just can easy and electric current between the source drain calculating described driving transistors accurately.
And then, the electric current being independently provided with the I-E characteristic for measuring organic electroluminescent device applies path and voltage detection path, so by the impact of the voltage drop caused by switching transistor 130, and the higher I-E characteristic measurement of precision can not can be carried out when this voltage detecting.
Below, the control method of the display device that embodiments of the invention 2 relate to is described.
In addition, the workflow diagram of the workflow diagram that the control method of the display device that embodiments of the invention 2 relate to is described and the bearing calibration that the control part that embodiments of the invention 2 relate to is described is identical with Fig. 6 and Fig. 7 illustrated in embodiment 1 respectively, so here omit the description.
Below, Figure 12 is used the supply timing of the electric signal of step SI0 and the step S11 performed in the workflow diagram recorded at Fig. 6 to be described and to detect timing.
Figure 12 represents the supply timing of the signal voltage for detecting drive transistor characteristics that embodiments of the invention 2 relate to and checks the detection time diagram regularly of voltage.In the figure, horizontal axis representing time.And on longitudinal direction, show following oscillogram by order from top to bottom: the oscillogram of voltage, the oscillogram at the voltage of the oscillogram of the voltage of control line 22 generation, the oscillogram of voltage, the voltage of data line 31 and the sense wire 53 in voltage-selected switch 65 generation that produce at sweep trace 21.
Secondly, at moment t1, the voltage level of voltage-selected switch 65 becomes high level, thus data line drive circuit 30 and data line 31 become conducting state, and the voltage level of sweep trace 21 becomes high level, thus switching transistor 130 becomes conducting state, thus perform to the applying of the first signal voltage of the grid of driving transistors 120, and the write of the first signal voltage to capacity cell 150.
Secondly, at moment t2, the voltage of voltage-selected switch 65 becomes low level, data line drive circuit 30 and sense wire 53 become conducting state, and the voltage level of sweep trace 21 becomes low level, switching transistor 130 becomes cut-off state, thus the applying terminated to the first signal voltage of the grid of driving transistors 120 and the first signal voltage write to capacity cell 150.Now, driving transistors 120 makes the electric current corresponding with the first signal voltage that capacity cell 150 keeps continue to flow to organic electroluminescent device 110.Like this, organic electroluminescent device 110 continues to perform luminous work.
Secondly, at moment t4, the voltage level of control line 22 becomes high level, checks that transistor 160 becomes conducting state, thus the anode of organic electroluminescent device 110 and sense wire 53 conducting.
Secondly, at moment t5, under the state that organic electroluminescent device 110 continues luminous work, voltage detecting circuit 50 detects the voltage of sense wire 53, thus is tested with the anode voltage of electro-luminescence element 110.
Finally, at moment t6, the voltage level of control line 22 becomes low level, checks that transistor 160 becomes cut-off state, thus terminates a series of work.
In addition, by the first signal voltage is replaced into secondary signal voltage, above-mentioned time diagram is also applicable to the supply timing of the electric signal in the workflow diagram recorded at Fig. 6 in the step S12 that performs and step S13 and detects timing.
The time diagram that each step recorded according to Fig. 6 and Figure 12 record, for two of determined organic electroluminescent device 110 different anode voltages, signal voltages different from two of data line drive circuit 30 supply when luminescence works usually can be utilized, measure accurately.And, the anode voltage that two of organic electroluminescent device 110 are after measured different, can according to the voltage-current characteristic of the aforesaid organic electroluminescent device be stored in advance in storer 80, be converted into the electric current that two of flowing to organic electroluminescent device 110 are different.Further, according to the annexation between organic electroluminescent device 110 and driving transistors 120, between the source drain of these two kinds of electric currents and driving transistors 120, electric current is equal.Therefore, for the anode voltage of organic electroluminescent device 110, do not need the special voltage input performed in addition for measuring this voltage, and by the different signal voltage of two when using usually luminous work, just can the easy and electric current that between the source drain calculating driving transistors 120 accurately two are different.
And, voltage detecting circuit 50 is via not being connected to the sense wire 53 of basic pixel circuit to detect the anode voltage of organic electroluminescent device 110, so not by the impact of the voltage drop caused by switching transistor 130 grade as the inscape of basic pixel circuit, and the anode voltage of organic electroluminescent device 110 can be measured further accurately.
More than utilize embodiment 1 and 2 to describe display device of the present invention and control method thereof, but the display device that the present invention relates to and control method thereof not limit by described embodiment.For above-described embodiment, the various equipment implementing various change and the variation obtained that those skilled in the art expect and/or the built-in display device that the present invention relates in the scope not exceeding purport of the present invention are also included within the present invention.
Such as, the display device that the present invention relates to and control method thereof, be built in the thin, planar televisor as Figure 13 record, and used.Use the display device and control method thereof that the present invention relates to, can realize including the thin, planar televisor that brightness disproportionation obtains the display of suppression.
And can be: the light-emitting component that pixel portion has, its negative pole is connected to the source electrode of driving transistors and the side in draining, its anode is connected to the first power supply, same with above-described embodiment, the grid of driving transistors, be connected to data line via switching transistor, driving transistors source electrode and the opposing party in draining are connected to second source.When this circuit structure, the potential setting of the first power supply must be higher than the current potential of second source.And inspection transistor, its grid is connected to control line, and its source electrode and the side in draining are connected to data line, and its source electrode and the opposing party in draining are connected to the negative pole of light-emitting component.In this circuit structure, also can obtain the structure same with the present invention and effect.
And, describe the n-type transistor such as becoming conducting state when the voltage level of the grid of switching transistor is high level in the above-described embodiments, even if but, switching transistor, inspection transistor and driving transistors is being formed by p-type transistor, make in the electronic installation of the polarity inversion of data line, sweep trace and control line, also can easy and electric current and the gain coefficient calculated according to them and threshold voltage between the source drain obtaining driving transistors accurately, the effect same with above-mentioned each embodiment can be obtained.
And, in an embodiment of the present invention, by there is driving transistors, switching transistor and check the transistor of each function of transistor be comprise grid, source electrode and drain electrode field effect transistor (FET:Field Effect Transistor) premised on be illustrated, but also can be suitable for the bipolar transistor comprising base stage, collector and emitter for these transistors.In this situation, also can reach object of the present invention, and obtain same effect.
The present invention is particularly useful for the organic EL display of built-in display device, uses as the best as to the display device of the high display of the uniformity requirements of picture quality and the uneven detection method of characteristic thereof.
5 luminescent panels
10 display parts
30 data line drive circuits
60 multiplexers
65 voltage-selected switches
140,160 check transistor
701 voltage control divisions
702 conversion portions
First power lead, it is electrically connected with the first electrode of described light-emitting component;
Second source line, it is electrically connected with the second electrode of described light-emitting component;
Capacitor, it keeps voltage;
Driving transistors, it is arranged between described first electrode and described first power lead, and the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, makes described light-emitting component luminous;
Data line, it is to the electrode suppling signal voltage of a side of described capacitor;
First on-off element, its voltage making described capacitor keep corresponding with described signal voltage;
Data line drive circuit, it is to described data line suppling signal voltage;
Voltage detecting circuit, it is connected to described data line, detects the voltage of described light-emitting component;
Second switch element, it makes described first electrode be connected with described data line with the tie point of described driving transistors;
Control part, it is conducting state by making described first on-off element, make the voltage that described capacitor keeps corresponding with the first signal voltage supplied by described data line, by described driving transistors, the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, make described light-emitting component luminous, and during described light-emitting component luminescence, be cut-off state by making described first on-off element, described second switch element is made to be conducting state, the connection of described data line drive circuit and described data line is made to be off state, thus make described voltage detecting circuit detect the first current potential of described tie point via described data line, be conducting state by making described first on-off element, make the voltage that described capacitor keeps corresponding with the secondary signal voltage supplied by described data line, and by described driving transistors, the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, make described light-emitting component luminous, described secondary signal voltage is different from described first signal voltage, during described light-emitting component luminescence, be cut-off state by making described first on-off element, described second switch element is made to be conducting state, the connection of described data line drive circuit and described data line is made to be off state, thus make described voltage detecting circuit detect the second current potential of described tie point via described data line, and
Conversion portion, it is by described first current potential of described tie point that detected by described voltage detecting circuit and described second current potential, be scaled the first electric current and the second electric current that flow between the source drain of described driving transistors respectively, by deducting from described first signal voltage the supply voltage be set on described first power lead, the voltage obtained is set to Vgs1, described first power lead is be connected to the source electrode of described driving transistors and the side in draining, the voltage obtained deducting described supply voltage from described secondary signal voltage is set to Vgs2, described first electric current is set to I1, described second electric current is set to I2, by the channel region with described driving transistors, oxide film electric capacity and the relevant gain function of mobility are set to β, and when the threshold voltage of described driving transistors is set to Vth,
Following formula 1 is used to calculate the gain coefficient of described driving transistors and described threshold voltage,
Vth = V gs 2 &times; 2 I 1 - V gs 1 &times; 2 I 2 2 I 1 - 2 I 2 .
2. display device as claimed in claim 1, also comprises:
Storer, which stores the data corresponding with the voltage-current characteristic of described light-emitting component,
Described conversion portion, the data corresponding with the voltage-current characteristic of described light-emitting component stored according to described storer, by described first current potential of described tie point that detected by described voltage detecting circuit and described second current potential, be scaled described first electric current and described second electric current that flow between the source drain of described driving transistors respectively.
Described light-emitting component, described capacitor and described driving transistors form pixel portion,
The data corresponding with the voltage-current characteristic of described light-emitting component are data of the voltage-current characteristic of the light-emitting component in described pixel portion.
Also there is multiple pixel portion be made up of described light-emitting component, described capacitor and described driving transistors,
The data corresponding with the voltage-current characteristic of described light-emitting component are data of the voltage-current characteristic of the light-emitting component representing multiple described pixel portion.
Pixel portion is formed by described light-emitting component, described capacitor and described driving transistors,
Described display device comprises luminescent panel, and described luminescent panel has multiple described pixel portions and multiple data line, and described multiple data line is connected with described multiple pixel portion respectively,
Described voltage detecting circuit comprises:
More than one voltage-level detector, it, via the more than one data line selected from described multiple data line, detects the current potential of described tie point; And
Multiplexer, it is connected between described multiple data line and described more than one voltage-level detector, makes described by the more than one data line selected and described more than one voltage-level detector conducting,
Described in the number ratio of described more than one voltage-level detector, the number of multiple data line is few.
6. display device as claimed in claim 5,
Described multiplexer is formed on described luminescent panel.
7. display device as claimed in claim 1,
Described first electrode is the anode electrode of described light-emitting component,
Described in the voltage ratio of described first power lead, the voltage of second source line is high, and electric current flows to described second source line from described first power lead.
8. a control method for display device, described display device comprises:
Voltage detecting circuit, it is connected to described data line, detects the voltage of described light-emitting component; And
Second switch element, it makes described first electrode be connected with described data line with the tie point of described driving transistors,
The control method of described display device:
Be conducting state by making described first on-off element, make the voltage that described capacitor keeps corresponding with the first signal voltage supplied by described data line, by described driving transistors, the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, make described light-emitting component luminous
During described light-emitting component luminescence, be cut-off state by making described first on-off element, described second switch element is made to be conducting state, the connection of described data line drive circuit and described data line is made to be off state, thus make described voltage detecting circuit detect the first current potential of described tie point via described data line
By the first current potential of described tie point detected by described voltage detecting circuit, be scaled the first electric current flowed between the source drain of described driving transistors,
Be conducting state by making described first on-off element, make the voltage that described capacitor keeps corresponding with the secondary signal voltage supplied by described data line, and by described driving transistors, the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, make described light-emitting component luminous, described secondary signal voltage is different from described first signal voltage
During described light-emitting component luminescence, by making described first on-off element be cut-off state, making described second switch element be conducting state, making described voltage detecting circuit detect the second current potential of described tie point via described data line,
By the second current potential of the described described tie point detected, be scaled the second electric current flowed between the source drain of described driving transistors,
By deducting from described first signal voltage the supply voltage be set on described first power lead, the voltage obtained is set to Vgs1, described first power lead is be connected to the source electrode of described driving transistors and the side in draining, the voltage obtained deducting described supply voltage from described secondary signal voltage is set to Vgs2, described first electric current is set to I1, described second electric current is set to I2, by the channel region with described driving transistors, oxide film electric capacity and the relevant gain function of mobility are set to β, and when the threshold voltage of described driving transistors is set to Vth,
Following formula 2 is used to calculate the gain coefficient of described driving transistors and described threshold voltage,
9. the control method of display device as claimed in claim 8,
Described display device comprises storer, and it stores the data corresponding with the voltage-current characteristic of described light-emitting component,
The data corresponding with the voltage-current characteristic of described light-emitting component that the control method of described display device stores according to described storer, are scaled described first electric current and described second electric current respectively by described first current potential and described second current potential.
Sense wire, it reads the voltage of described light-emitting component;
Voltage detecting circuit, it is connected to described sense wire, detects the voltage of described light-emitting component;
Second switch element, it makes described first electrode be connected with described sense wire with the tie point of described driving transistors;
Control part, it is conducting state by making described first on-off element, make the voltage that described capacitor keeps corresponding with the first signal voltage supplied by described data line, by described driving transistors, the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, make described light-emitting component luminous, and during described light-emitting component luminescence, be cut-off state by making described first on-off element, described second switch element is made to be conducting state, the connection of described data line drive circuit and described data line is made to be off state, thus via described sense wire, the first potentiometric detection of described tie point is gone out, be conducting state by making described first on-off element, make the voltage that described capacitor keeps corresponding with the secondary signal voltage supplied by described data line, and by described driving transistors, the electric current corresponding with the voltage that described capacitor keeps is flowed between described first power lead and described second source line, make described light-emitting component luminous, described secondary signal voltage is different from described first signal voltage, during described light-emitting component luminescence, be cut-off state by making described first on-off element, described second switch element is made to be conducting state, the connection of described data line drive circuit and described data line is made to be off state, thus via described sense wire, the second potentiometric detection of described tie point is gone out, and
Following formula 3 is used to calculate the gain coefficient of described driving transistors and described threshold voltage,
CN200980100456.2A 2008-07-04 2009-06-30 Display device and method for controlling the same CN101960509B (en)
JP176243/2008 2008-07-04
CN101960509A CN101960509A (en) 2011-01-26
CN101960509B true CN101960509B (en) 2015-04-15
CN200980100456.2A CN101960509B (en) 2008-07-04 2009-06-30 Display device and method for controlling the same
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US20170358260A1 (en) 2017-12-14 Active-matrix display device, and active-matrix organic electroluminescent display device