CN1722207A - Pixel circuit, display device, driving method of pixel circuit, and driving method of display device - Google Patents
Pixel circuit, display device, driving method of pixel circuit, and driving method of display device Download PDFInfo
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- CN1722207A CN1722207A CN200510081957.4A CN200510081957A CN1722207A CN 1722207 A CN1722207 A CN 1722207A CN 200510081957 A CN200510081957 A CN 200510081957A CN 1722207 A CN1722207 A CN 1722207A
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Abstract
The invention provides a pixel circuit which can compensate the aging brightness deterioration. A sampling transistor (Trl) acts when being selected by a scanning wire (WS), samples input signals (Vsig) from a signal line DL and is kept at a holding capacitance (Cs). A driving transistor (Tr2) supplies driving current (Ids) to a light emitting element (EL) according to the signal potential which is kept at the holding capacitance (Cs). A compensating circuit which is used for compensating the brightness decreasing caused by the change of the aging is added in the pixel circuit. The change of the aging is detected from the lateral of an output node and the detecting result is fed back to the lateral of an input node (A).
Description
Technical field
The present invention relates to the image element circuit that current drives is configured in the load elements on each pixel.In addition, this image element circuit is to be aligned to rectangular display device, particularly relates to being arranged on isolated-gate field effect transistor (IGFET) in each image element circuit to the display device of the so-called active array type of the magnitude of current of the load elements control energising of organic EL luminous element etc.
Background technology
In image display device, for example LCD, rectangular by a plurality of liquid crystal pixels are arranged in, according to the image information that will show to each pixel control incident light see through intensity or reflection strength is come display image.Here, in the OLED display that organic EL is used for pixel too, and the organic EL different with liquid crystal pixel is self-emission device.Therefore, compare with LCD, OLED display have image visuognosis degree height, do not need advantages such as backlight, response speed be fast.In addition, the luminance level of each light-emitting component (gray shade scale) is controllable according to the current value that flows through it, on the problem of so-called current-control type, is very different with LCD.
In OLED display, the same with LCD, as its type of drive, simple matrix mode and active matrix mode are arranged.The former is because simple structure, exists the problem that realizes large-scale and high meticulous demonstration difficulty etc., now, is actively carrying out the exploitation of active matrix mode.This mode be will on the light-emitting component of each pixel inside, flow through electric current with the active component that is arranged on image element circuit inside (thin film transistor (TFT) normally, the mode of TFT) controlling, on the books in the following patent documentation.
[patent documentation 1] spy opens 2003-255856
[patent documentation 2] spy opens 2003-271095
Summary of the invention
[problem that invention will solve]
Present image element circuit is expert at by configuration respectively on the signal wire cross section of the sweep trace of shape and row shape.Each image element circuit includes the load elements of the sampling transistor of film-type, the driving transistors that keeps electric capacity, film-type, light-emitting component etc. at least.The grid of sampling transistor is by sweep trace when selected, source/drain interpolar conducting and from the signal wire sampled image signal.The signal of being taken a sample is written into and remains on and keeps on the electric capacity.The grid of driving transistors be connected keep on the electric capacity, on a side of source/drain is connected to light-emitting component etc. the load elements.The grid of driving transistors is the gate voltage of benchmark according to being maintained at the signal voltage acceptance that keeps on the electric capacity with the source electrode.Driving transistors flows through electric current according to this gate voltage at the source/drain interpolar, switches on to light-emitting component.Usually, the brightness of light-emitting component is proportional to the energising amount.Moreover the energising amount of driving transistors promptly is written in the signal potential that keeps on the electric capacity and is controlled by gate voltage.Thereby light-emitting component is luminous with the brightness corresponding to picture signal.
The operating characteristic of driving transistors is represented with following formula.
Ids＝(1/2)μ(W/L)Cox(Vgs-Vth)2
In this transistor characteristic formula, Ids represents drain current.Vgs represents with the source electrode to be that benchmark is applied to the voltage on the grid.Vth is transistorized threshold voltage.Remaining μ represents the mobility of semiconductive thin film of the raceway groove of transistor formed, and W represents channel width, and L represents channel length, and Cox represents gate capacitance.From this transistor characteristic as can be known, when thin film transistor (TFT) is worked in the zone of saturation, if grid voltage Vgs surpasses threshold voltage and when being worth greater than this, then becoming conducting state and flow through drain current Ids.Knowing from above-mentioned transistor characteristic formula, if grid voltage Vgs is certain, usually, should be that the drain current Ids of equivalent flows through light-emitting component.But, exist the problem that produces deterioration in brightness with the process of service time.
The invention is characterized in: image element circuit is configured on sweep trace and the signal wire cross section, at least be provided with electrooptic cell, driving transistors, sampling transistor, keep electric capacity, the gate electrode of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined supply voltage, one end of this electrooptic cell is connected on the output node, the other end is connected to predetermined current potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected on this input node, the time action in being scanned line selection of above-mentioned sampling transistor, sampling is from the input signal of this signal wire and remain on this maintenance electric capacity, above-mentioned driving transistors is being supplied with in the image element circuit of drive current to this electrooptic cell according to the signal potential that remains on this maintenance electric capacity, be provided with in order to compensation follow this transistorized through the time drive current that the changes compensating circuit that descends, above-mentioned compensating circuit detects the decline of this drive current from this output node side, and its result is fed back to this input node side.
Ideal situation is, above-mentioned compensating circuit detects the voltage drop that produces at this electrooptic cell according to this drive current from this output node side, relatively the level of the level of this input signal and this voltage drop that is detected and obtain difference will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.Specifically, above-mentioned compensating circuit is by constituting with the lower part, and they are: be connected detection electric capacity between this output node and the predetermined intermediate node, be inserted in switching transistor between this intermediate node and this signal wire, be inserted in the terminal node of an end that is connected to this maintenance electric capacity and the earthing potential be scheduled between switching transistor, be inserted in the switching transistor between this terminal node and this output node and be inserted in this terminal node and this intermediate node between switching transistor.
The present invention comprises by the signal wire of sweep trace, the row shape of row shape, be configured in the display device that the image element circuit on both crossover sites constitutes respectively.Each image element circuit is provided with electrooptic cell at least, driving transistors, sampling transistor, keep electric capacity, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected on this input node, the time action in being scanned line selection of above-mentioned sampling transistor, sampling is from the input signal of this signal wire and remain on this maintenance electric capacity, above-mentioned driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, and shows.It is characterized in that, above-mentioned image element circuit be provided with in order to compensation follow this driving transistors through the time drive current that changes the compensating circuit of decline.Above-mentioned compensating circuit detects the decline of this drive current from this output node side, and its result is fed back to this input node side.
Ideal situation is, above-mentioned compensating circuit detects the voltage drop that produces at this photovalve according to this drive current from this output node side, relatively the level of the level of this input signal and this voltage drop that is detected and obtain difference will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.Specifically, above-mentioned compensating circuit is by constituting with the lower part, and they are: be connected detection electric capacity between this output node and the predetermined intermediate node, be inserted in switching transistor between this intermediate node and this signal wire, be inserted in the terminal node on the end that is connected to this maintenance electric capacity and the earthing potential be scheduled between switching transistor, be inserted in the switching transistor between this terminal node and this output node and be inserted in this terminal node and this intermediate node between switching transistor.
In addition, in the driving method of image element circuit of the present invention, described image element circuit is configured on sweep trace and the signal wire cross section, at least be provided with electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected the input node, its source electrode is connected output node, its drain electrode is connected on the predetermined power supply potential, a wherein end of this electrooptic cell is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is being connected to this input node, it is characterized in that: the time action in being scanned line selection of above-mentioned sampling transistor, from this input signal cable to input signal sampling and remain on this maintenance electric capacity, above-mentioned driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, detect the decline of this drive current from this output node side, its result is fed back to this input node side, and compensation follow this transistorized through the time drive current that changes decline.
In addition, in the driving method of display device of the present invention, its display device is by the sweep trace of row shape, the signal wire of row shape, the image element circuit that is configured in respectively on both cross sections constitutes, above-mentioned image element circuit is provided with electrooptic cell at least, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected the input node, its source electrode is connected output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is being connected to this input node, it is characterized in that: the time action in being scanned line selection of above-mentioned sampling transistor, from this signal wire to input signal sampling and remain on this maintenance electric capacity, above-mentioned driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, and when showing, detect the decline of this drive current from this output node side, its result is fed back to this input node side, and compensation follow this driving transistors through the time drive current that changes decline.
In addition, in the image element circuit of the present invention, the image element circuit that is configured on sweep trace and the signal wire crossover sites is provided with at least: electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected on this input node, the time action in being scanned line selection of above-mentioned sampling transistor, from this signal wire to input signal sampling and remain on this maintenance electric capacity, above-mentioned driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, it is characterized in that: be provided with in order to compensation follow this driving transistors through the time drive current that changes the compensating circuit of decline, feed back to this input node side for the decline that detects this drive current from this output node side and with its result, above-mentioned compensating circuit is provided with: will be done accumulating of certain hour and exported corresponding to the detecting unit that detects current potential of accumulating the quantity of electric charge by the electric charge of this drive current carrying; Relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to the feedback unit on this signal potential that remains on this maintenance electric capacity corresponding to the current potential of this difference.
Specifically, above-mentioned compensating circuit is by constituting with the lower part: be inserted in the switching transistor between this output node and this electrooptic cell, be connected another switching transistor of this output node, detection electric capacity between the earthing potential that is connected this switching transistor and is scheduled to, feedback capacity between the intermediate node that is connected this output node and is scheduled to, be inserted in the switching transistor between this intermediate node and this signal wire, switching transistor between the earthing potential that is inserted in the terminal node of an end that is connected to this maintenance electric capacity and is scheduled to, be inserted in the switching transistor between this terminal node and this output node and be inserted in this terminal node and this intermediate node between switching transistor.
In addition, the present invention comprises by row shape sweep trace, the signal wire of row shape, be configured in the display device that the image element circuit on both cross sections constitutes respectively, it is characterized in that: each image element circuit is provided with electrooptic cell at least, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected on this input node, the time action in being scanned line selection of above-mentioned sampling crystal, to input signal sampling and remain on this maintenances electric capacity, above-mentioned driving transistors is according to remaining on signal potential on this maintenance electric capacity to this electrooptic cell supply drive current from this signal wire; Thereby, in the above-mentioned image element circuit that shows, be provided with in order to compensation follow this driving transistors through the time drive current that the changes compensating circuit that descends, above-mentioned compensating circuit feeds back to this input node side for the decline that detects this drive current from this output node side and with its result, is provided with: will do accumulating of certain hour and export corresponding to the detecting unit that detects current potential of accumulating the quantity of electric charge according to the electric charge that this drive current is carried; Relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to the feedback unit on this signal potential that remains on this maintenance electric capacity corresponding to the current potential of this difference.
Specifically, above-mentioned compensating circuit is by constituting with the lower part: be inserted in the switching transistor between this output node and this electrooptic cell, be connected another switching transistor on this output node, detection electric capacity between the earthing potential that is connected this switching transistor and is scheduled to, feedback capacity between the intermediate node that is connected this output node and is scheduled to, be inserted in the switching transistor between this intermediate node and this signal wire, switching transistor between the earthing potential that is inserted in the terminal node of an end that is connected to this maintenance electric capacity and is scheduled to, be inserted in the switching transistor between this terminal node and this output node and be inserted in this terminal node and this intermediate node between switching transistor.
In addition, in the driving method of image element circuit of the present invention, the image element circuit that is configured on the crossover sites of sweep trace and signal wire is provided with electrooptic cell at least, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, and this maintenance electric capacity is being connected to this input node; It is characterized in that: the time action in being scanned line selection of above-mentioned sampling transistor, from this signal wire to input signal sampling and remain on this maintenance electric capacity, above-mentioned driving transistors supplies with drive current for this electrooptic cell according to being maintained at the signal potential that keeps on the electric capacity, detect the decline of drive current from this output node side, its result is fed back to this input node side, for compensate follow this driving transistors through the time drive current that changes decline, to do accumulating of certain hour and obtain by the electric charge of this drive current carrying corresponding to the current potential that detects of accumulating the quantity of electric charge, relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.
In the driving method of display device of the present invention, display device is by the sweep trace of row shape, the signal wire of row shape, the image element circuit that is configured in respectively on both cross sections constitutes, above-mentioned image element circuit is provided with electrooptic cell at least, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected on the input node, this source electrode is connected on the output node, this drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, and this maintenance electric capacity is being connected to this input node; It is characterized in that: the time action in being scanned line selection of above-mentioned sampling transistor, from this signal wire to input signal sampling and remain on this maintenance electric capacity, above-mentioned driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, and when showing, detect the decline of this drive current from output node one side, its result is fed back to this input node side, for compensate follow this driving transistors through the time drive current that changes decline, to do accumulating of certain hour and obtain by the electric charge of this drive current carrying corresponding to the current potential that detects of accumulating the quantity of electric charge, relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to corresponding to the current potential of this difference to be maintained on this signal potential that keeps on the electric capacity.
In addition, among the present invention, be configured in the image element circuit on sweep trace and the signal wire cross section, at least be provided with electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected on this input node, the time action in being scanned line selection of above-mentioned sampling transistor, from this signal wire to input signal sampling and remain on this maintenance electric capacity, above-mentioned driving transistors is being supplied with in the image element circuit of drive current to electrooptic cell according to the signal potential that remains on this maintenances electric capacity, be provided with in order to compensation follow this driving transistors through the time variation the compensating circuit of decline of drive current.Above-mentioned compensating circuit is characterised in that and is provided with detecting unit and feedback unit, the former has capacitive component, in order to feed back to this input node side for the decline that detects this drive current from this output node side and with its result, reach this drive current that flows into earthing potential from this output node according to the resistance components between the earthing potential that is inserted in this output node and is scheduled to, the voltage drop that produces on this resistance components is kept as detecting current potential; The latter relatively this input signal level and this level that detects current potential and obtain difference, will be added to corresponding to the current potential of this difference to be maintained at and keep on the electric capacity on this signal potential.
Specifically, above-mentioned compensating circuit is by constituting with the lower part, and they are: be inserted in the switching transistor between this output node and this electrooptic cell, be connected another switching transistor on this output node, between the predetermined earthing potential of this beginning transistor AND gate, be connected to the detection transistor of diode, the detection electric capacity that is connected in parallel with this detection transistor, feedback capacity between the intermediate node that is connected this output node and is scheduled to, be inserted in the switching transistor between this intermediate node and this signal wire, switching transistor between the earthing potential that is inserted in the terminal node of an end that is connected to this maintenance electric capacity and is scheduled to, be inserted in the switching transistor between this terminal node and this output node and be inserted in this terminal node and this intermediate node between switching transistor.
In addition, the present invention comprises by the signal wire of sweep trace, the row shape of row shape, is configured in the display device that the image element circuit on both cross sections constitutes respectively.Each image element circuit is provided with at least: electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected on this input node, the time action in being scanned line selection of above-mentioned sampling transistor, from this signal wire to input signal sampling and remain on this maintenance electric capacity, above-mentioned sampling transistor is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, and, in the display device that shows, above-mentioned image element circuit be provided with in order to compensation follow this driving transistors through the time drive current that changes the compensating circuit of decline.Above-mentioned compensating circuit is characterised in that and is provided with detecting unit and feedback unit, the former has capacitive component, in order to feed back to this input node side for the decline that detects this drive current from this output node side and with its result, reach the drive current that flows to earthing potential from this output node according to the resistance components between the earthing potential that is inserted in this output node and is scheduled to, the voltage drop that produces on this resistance components is kept as detecting current potential; The latter relatively this input signal level and this level that detects current potential and obtain difference, will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.
Specifically, above-mentioned compensating circuit is by constituting with the lower part, and they are: be inserted in the switching transistor between this output node and this electrooptic cell, be connected another switching transistor on this output node, between this switching transistor and predetermined earthing potential, be connected to the detection transistor of diode, the detection electric capacity that is connected in parallel with this detection transistor, feedback capacity between the intermediate node that is connected this output node and is scheduled to, be inserted in the switching transistor between this intermediate node and this signal wire, switching transistor between the earthing potential that is inserted in the terminal node of an end that is connected to this maintenance electric capacity and is scheduled to, be inserted in the switching transistor between this terminal node and this output node and be inserted in this terminal node and this intermediate node between switching transistor.
In the driving method of image element circuit of the present invention, the image element circuit that is configured on sweep trace and the signal wire cross section is provided with electrooptic cell at least, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is being connected to this input node, the time action in being scanned line selection of above-mentioned sampling transistor, sampling is from the input signal of this signal wire and remain on this maintenance electric capacity, and above-mentioned driving transistors is according to remaining on signal potential on this maintenances electric capacity to this electrooptic cell supply drive current.It is characterized in that: detect the decline of this drive current from this output node side, its result is fed back to this input node side, for compensate follow this driving transistors through the time drive current that changes decline, obtain the voltage drop and the conduct that produce on this resistance components according to this drive current that flows through on the resistance components between the earthing potential that is inserted in this output node and is scheduled to and detect current potential, relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.
In addition, in the driving method of display device of the present invention, described display device is made of the signal wire of retouching line, row shape of row shape, the image element circuit that is configured on both cross sections respectively, above-mentioned image element circuit is provided with electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity at least, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, and its drain electrode is connected on the predetermined power supply potential, and an end of this electrooptic cell is connected on the output node; It is characterized in that: the other end is connected on the predetermined current potential, and this sampling transistor is for being connected between this input node and this signal wire, and this maintenance electric capacity is being connected to this input node; It is characterized in that: the time action in being scanned line selection of above-mentioned sampling transistor, sampling is from the input signal of this signal wire and remain on this maintenance electric capacity, above-mentioned driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, and when showing, detect the decline of this drive current from this output node side, its result is fed back to this input node side, for compensate follow this driving transistors through the time drive current that changes decline, obtain the voltage drop and the conduct that on this resistance components, produce according to this drive current that on the resistance components between the earthing potential that is inserted in this output node and is scheduled to, flows through and detect current potential, relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.
In addition, the invention is characterized in, be configured in the image element circuit on sweep trace and the signal wire cross section, at least be provided with light-emitting component, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined power supply potential, one end of this light-emitting component is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal, this maintenance electric capacity is connected on this input node, the time action in being scanned line selection of above-mentioned sampling transistor, sampling is from the input signal of this signal wire and remain on this maintenance electric capacity, above-mentioned driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this light-emitting component, above-mentioned light-emitting component is in following the image element circuit luminous by the voltage drop of this drive current generation, adding in order to compensation by light-emitting component through the time brightness that change the to produce compensating circuit that descends, above-mentioned compensating circuit from this output node side detect along with this light-emitting component through the time change this voltage drop that increases, to feed back to this input node side corresponding to the signal potential of the level of this detected voltage drop, above-mentioned driving transistors is supplied with the drive current that the brightness that is enough to compensate this light-emitting component descends according to the signal potential of this feedback.
Specifically, above-mentioned compensating circuit is by constituting with the lower part, they are: comprise 2 detection electric capacity that are connected in series between this output node and this input node, above-mentioned be connected in series 2 detect electric capacity from this output node side detect keep in voltage drop that this light-emitting component produces and by each self-capacity ratio of division in, the level of this voltage decline of institute's retaining part on the detection electric capacity of this input node side that is held in place is fed back as this signal potential.More particularly, above-mentioned compensating circuit is by constituting with the lower part: detect a switching transistor that detection electric capacity inserts in parallel that is positioned at this output node side in the electric capacity with these 2 of being connected in series, be inserted at another of this input node side and detect switching transistor between electric capacity and the earthing potential of being scheduled to, be inserted at another detection electric capacity of this same input node side and the switching transistor between this input node, be inserted in the switching transistor between this maintenance electric capacity and the predetermined earthing potential and be inserted in this same maintenance electric capacity and the switching transistor between this output node.
Have again, the invention is characterized in, by row shape sweep trace, row shape signal wire, be configured in respectively in the image display device of the image element circuit formation on both cross sections, above-mentioned image element circuit is provided with light-emitting component at least, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined power supply potential, one end of this light-emitting component is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected on this input node, the time action in being scanned line selection of above-mentioned sampling transistor, sampling is from the input signal of this signal wire and remain on this maintenance electric capacity, above-mentioned driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this light-emitting component, and above-mentioned light-emitting component is following the voltage drop that is produced by this drive current luminous; Be inserted with in the above-mentioned image element circuit in order to compensation since this light-emitting component through the time brightness that change the to produce compensating circuit that descends, above-mentioned compensating circuit from this output node side detect along with this light-emitting component through the time change this voltage drop that increases, to feed back to this input node side corresponding to the signal potential of the level of this voltage drop that is detected, above-mentioned driving transistors is supplied with the drive current that the brightness that is enough to compensate this light-emitting component descends according to this signal potential that is fed.
Specifically, above-mentioned compensating circuit comprises 2 detection electric capacity that are connected in series between this output node and this input node, above-mentioned be connected in series 2 detect electric capacity from this output node side detect keep in voltage drop that this light-emitting component produces and by separately capacity ratio of division in, the level of this that part of voltage decline on the detection electric capacity of this input node side that is held in place is fed back as this signal potential.More particularly, above-mentioned compensating circuit is by constituting with the lower part, and they are: be inserted in these 2 of being connected in series and detect a detection electric capacity switching transistor in parallel that is positioned at this output node side in the electric capacity, be inserted at another of this input node side and detect switching transistor between electric capacity and the earthing potential of being scheduled to, be inserted at another detection electric capacity of this same input node side and the switching transistor between this input node, switching transistor between the earthing potential that is inserted in this maintenance electric capacity and is scheduled to, be inserted in this same maintenance electric capacity and the switching transistor between this output node.
Feature of the present invention also is, be configured in the image element circuit on sweep trace and the signal wire cross section, at least be provided with light-emitting component, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined power supply potential, one end of this light-emitting component is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is in the driving method of the image element circuit that is connected to this input node, the time action in being scanned line selection of above-mentioned sampling transistor, sampling is from the input signal of this signal wire and remain on this maintenance electric capacity, above-mentioned driving transistors is according to remaining on signal potential on this maintenance electric capacity to the light-emitting component supplying electric current, above-mentioned light-emitting component follows the voltage drop that is produced by this drive current luminous, moreover, for compensate by this light-emitting component through the time change the brightness cause and descend, from this output node side detect with this light-emitting component through the time change this voltage drop that increases, to feed back to this input node side corresponding to the signal potential of the level of this voltage drop that is detected, above-mentioned driving transistors is according to this signal potential that is fed, the drive current that the brightness that supplying with is enough to compensate this light-emitting component descends.
In addition, in the driving method of display device of the present invention, described display device is by the sweep trace of row shape, the signal wire of row shape, the image element circuit that is configured in respectively on both cross sections constitutes, above-mentioned image element circuit is provided with at least: light-emitting component, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected on the input node, its source electrode is connected on the output node, its drain electrode is connected on the predetermined power supply potential, one end of this light-emitting component is connected on the output node, the other end is connected on the predetermined current potential, this sampling transistor is connected between this input node and this signal wire, and this maintenance electric capacity is connected to this input node; It is characterized in that: the time action in being scanned line selection of above-mentioned sampling transistor, sampling is from the input signal of this signal wire and remain on this maintenance electric capacity, above-mentioned driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this light-emitting component, above-mentioned light-emitting component follows the voltage drop that is produced by this drive current luminous, and when showing, for compensate by this light-emitting component through the time change the brightness cause and descend, from this output node side detect corresponding to this light-emitting component through the time change this voltage drop that increases, to feed back to this input node side corresponding to the signal potential of the level of this voltage drop that is detected, above-mentioned driving transistors is supplied with the drive current that the brightness that is enough to compensate this light-emitting component descends according to this signal potential that is fed.
[effect of invention]
According to the present invention, added compensating circuit in the image element circuit, compensation follow driving transistors through the time drive current that changes decline.This compensating circuit by its result being fed back to input node one side, is eliminated the decline of drive current from the decline of output node one side detection drive current from circuit.Therefore, cause driving force to descend even the mobility of driving transistors descends, to feed back to input node one side and compensate it owing to apply, the result can keep drive current long-term identical with initial value, keeps constant level.Thereby, can prevent to result from the deterioration in brightness of driving transistors, can keep image evenness for a long time.
In addition,, added compensating circuit in the image element circuit according to the present invention, will owing to light-emitting component through the time change the brightness cause and descend and compensate from circuit with pixel unit.Simultaneously, can compensate the initial brightness fluctuation of the light-emitting component that occurs on each pixel.This compensating circuit according to light-emitting component through the time change, the fact that the voltage drop that produces on the light-emitting component is increased is used as principle.That is, if light-emitting component because of through the time deterioration, brightness slowly descends, and corresponding to this tendency of the reverse increase of voltage drop is arranged.Detect the voltage drop of this increase from output node one side, to feed back to input node one side corresponding to its signal potential, driving transistors is often supplied with drive current from output node according to the signal potential that is fed on the direction that the brightness that remedies light-emitting component descends.So, can prevent the deterioration in brightness of light-emitting component, can keep image evenness for a long time.Simultaneously, compensate the original intensity fluctuation of the light-emitting component that occurs on each pixel, also can improve image evenness.
Description of drawings
[Fig. 1] is the block scheme of the general structure of expression active matrix display devices and image element circuit.
[Fig. 2] is the circuit diagram of the reference example of remarked pixel circuit.
[Fig. 3] is the time diagram that is used for the action specification of image element circuit shown in Figure 2.
[Fig. 4] be the expression organic EL the I-V characteristic through the time curve map that changes.
[Fig. 5] be expression driving transistors and organic EL the working point through the time variation curve map.
[Fig. 6] is the circuit diagram of other reference example of remarked pixel circuit.
[Fig. 7] is the time diagram that is used for the action specification of image element circuit shown in Figure 6.
[Fig. 8] is the circuit diagram of the embodiment of expression image element circuit of the present invention.
[Fig. 9] is the time diagram that is used for the action specification of embodiment shown in Figure 8.
[Figure 10] is the circuit diagram of other embodiment of expression image element circuit of the present invention.
[Figure 11] is the time diagram that is used for the action specification of other embodiment shown in Figure 10.
[Figure 12] is the circuit diagram of other embodiment of expression image element circuit of the present invention.
[Figure 13] is the time diagram that is used for the action specification of other embodiment shown in Figure 12.
[Figure 14] is the circuit diagram of other embodiment of expression image element circuit of the present invention.
[Figure 15] is the time diagram that is used for the action specification of other embodiment shown in Figure 14.
[description of symbols]
1... pel array, 2... horizontal selector, 3... driven sweep device, 4... photoscanner, 5... image element circuit, 7... compensating circuit
Embodiment
Below, embodiments of the present invention will be described in detail with reference to the accompanying drawings.At first, in order to understand fully background of the present invention,, and active matrix display devices and the general structure that is included in image element circuit wherein described as a reference example with reference to Fig. 1.As shown in the figure, active matrix display devices is by constituting as the pel array 1 of major part and the circuit group of periphery.The circuit group of periphery comprises level and selects and select device 2, driven sweep device 3, photoscanner 4 etc.
Fig. 2 is the reference diagram that expression constitutes the basic structure of image element circuit 5 shown in Figure 1.This image element circuit 5 is by taking a sample with thin film transistor (TFT) (sampling transistor Tr1), driving with thin film transistor (TFT) (driving transistors Tr2), switch thin film transistor (TFT) (switching transistor Tr3), maintenance capacitor C 1, load elements formations such as (organic EL luminous elements).
Sampling transistor Tr1 conducting in being scanned line selection the time is from signal wire DL sampled image signal and remain on and keep on the capacitor C 1.Driving transistors Tr2 is according to remaining on the signal potential control that keeps on the capacitor C 1 energising amount to light-emitting element E L.Switching transistor Tr3 is controlled by sweep trace DS, and conducting/disconnection is to the energising of light-emitting element E L.That is driving transistors Tr2 is according to the glorious degrees (brightness) of energising amount control light-emitting element E L, and on the other hand, switching transistor Tr3 controls the fluorescent lifetime of light-emitting element E L.By these control, be included in light-emitting element E L in each image element circuit 5 and present briliancy corresponding to picture signal, on pel array 1, demonstrate desired image.
Fig. 3 is the time diagram that is used for the action specification of pel array shown in Figure 21 and image element circuit 5.The beginning of (1f) during 1 on the image element circuit 5 of the 1st row when 1 horizontal period (1H), applies strobe pulse ws[1 by sweep trace WS], sampling transistor Tr1 conducting.So, from signal wire DL sampled image signal, be written on the maintenance capacitor C 1, keep an end of capacitor C 1 to be connected on the grid of driving transistors Tr2.Thereby, in case being written to, picture signal keeps on the capacitor C 1, the grid potential of driving transistors Tr2 just rises by the signal potential that is write.At this moment, apply strobe pulse ds[1 by another sweep trace DS to switching transistor Tr3].During this, light-emitting element E L continues luminous.1f's is later half during 1, because ds[1] become low level, light-emitting element E L becomes non-luminance.By adjusting pulse ds[1] duty, can adjust between light emission period and the ratio between non-light emission period, the picture brightness that obtains wishing.In case transfer to next horizontal period, to the image element circuit of the 2nd row, from each sweep trace WS, DS applies scanning signal pulse ws[2 separately], ds[2].
Fig. 4 be expression current-voltage (I-V) characteristic that joins the organic EL of image element circuit 5 as light-emitting component through the time curve that changes.In curve, the characteristic during with the curve representation original state shown in the solid line, the curve representation that is shown in broken lines through the time characteristic after changing.Usually, the I-V characteristic of organic EL like that, as time passes, will produce deterioration shown in curve.The image element circuit of reference example shown in Figure 2, driving transistors constitute source electrode and follow structure, can not handle the I-V characteristic through the time change, exist the so-called problem that produces the luminosity deterioration.
Fig. 5 (A) is the curve that is illustrated in the working point of the driving transistors Tr2 of original state and light-emitting element E L.Among the figure, transverse axis is represented drain electrode-voltage between source electrodes Vds of driving transistors Tr2, and the longitudinal axis is represented electric current I ds between drain electrode-source electrode.As shown in the figure, source potential is by the decision of the working point of driving transistors Tr2 and light-emitting element E L, and its magnitude of voltage keeps on the different value with gate voltage is different.Because driving transistors Tr2 works in the zone of saturation,, drive drive current by aforementioned transistor characteristic formula predetermined electric current value corresponding to the source voltage Vgs of working point.
But, the I-V characteristic of light-emitting element E L can occur shown in Figure 4 through the time deterioration.Shown in Fig. 5 (B) and since this through the time change, variation has taken place in the working point, even apply identical gate voltage, transistorized source voltage also changes.So voltage Vgs can change between grid-source of driving transistors Tr2, the current value change of flowing through.Simultaneously, the flow through current value of light-emitting element E L also changes.So, in case the I-V characteristic variations of light-emitting element E L follow in the image element circuit of structure at the source electrode of reference example shown in Figure 2, with regard to exist light-emitting element E L brightness through the time problem that changes.
Another reference example of image element circuit shown in Figure 6 is to have made improved image element circuit at the problem points of previous reference example shown in Figure 2.For ease of understanding, the part corresponding with the reference example of Fig. 2 is with corresponding reference marker.Improvement place is the connection of having replaced switching transistor Tr3, so, realized the bootstrapping function.Specifically, the source electrode of switching transistor transistor Tr 3 is grounded, and drain electrode is connected with an electrode that keeps capacitor C 1 with the source electrode (S) of driving transistors Tr2, connects sweep trace DS on the grid.Have again, keep another electrode of capacitor C 1 to be connected to driving transistors Tr2 grid (G).
Fig. 7 is the time diagram that is used for the action specification of image element circuit shown in Figure 65.Among the initial horizontal period 1H in field interval 1f, send strobe pulse ws[1 by sweep trace WS to the image element circuit 5 of the 1st row] from photoscanner 4.Have, the numeral in [] is corresponding to by the row of the image element circuit of matrix configuration number again.In case apply strobe pulse, sampling transistor Tr1 takes a sample to input signal Vin from signal wire DL with regard to conducting, and is written on the maintenance capacitor C 1.At this moment, be applied on the switching transistor Tr3 from the strobe pulse ds[1 of driven sweep device 3 via sweep trace DS], become conducting state.Thereby, keep electrode of capacitor C 1 and the source electrode (S) of driving transistors Tr2 to become GND (ground connection) level.Because as benchmark, to keeping capacitor C 1 to write input signal Vin, the grid current potential (G) of driving transistors Tr2 becomes Vin with this GND level.
Afterwards, remove strobe pulse ws[1 to sampling transistor Tr1], then, also remove strobe pulse ds[1] to switch transistor Tr 3.Thereby sampling transistor Tr1 and switching transistor Tr3 end.Thereby the source electrode of driving transistors Tr2 (S) disconnects from GND, constitutes the connected node to light-emitting element E L anode.
Accept on the grid of driving transistors Tr2 to be maintained at the input signal Vin that keeps on the capacitor C 1, make drain current corresponding to this value from Vcc side direction GND side flow.It is luminous that this energising makes that light-emitting element E L carries out.At this moment, because to light-emitting element E L energising, voltage drop produces, but source potential (S) is from GND one side direction Vcc one side this part amount that rises.In the time diagram of Fig. 7, this rising part is represented with Δ V.One end of maintenance capacitor C 1 is connected to the source electrode of Tr2, and the other end is connected on the grid (G) of high impedance.Therefore, the Δ V if source potential only rises, the also grid potential (G) of this part amount of lifting only, input signal Vin remains stationary in fact.Thereby according to the I-E characteristic of light-emitting element E L, source potential (S) is even change Δ V, and usually, grid current potential Vgs=Vin sets up, and it is constant that drain current is held.That is, although being source electrode, driving transistors Tr2 follows structure, because above-mentioned bootstrapping function plays the effect of constant current source to light-emitting element E L.
Afterwards, in case strobe pulse ds[1] recovering high level, switching transistor Tr3 is with regard to conducting, because the electric current that will supply with light-emitting element E L is become non-luminance by bypass.Like this,, then enter next field interval, on sampling transistor Tr1, apply strobe pulse ws[1 again if field interval 1f finishes], carry out the sampling of received image signal Vin*.Since exist during the preceding field with field interval specifically in the different situation of level of the picture signal of being taken a sample, in order to distinguish it, diacritic * on received image signal Vin.In addition, such picture signal write and luminous action is undertaken by line preface (row unit).For this reason, to pixel each the row, apply strobe pulse ws[1 successively], ws[2] ....Equally, also apply strobe pulse ds[1 successively], ds[2] ....
As above-mentioned, even driving transistors Tr2 is the N channel-type, the image element circuit of Fig. 6 also can constant-current driving light-emitting element E L, can prevent by the I-V characteristic of light-emitting element E L through the time change the deterioration in brightness that produces.But, by aging produce through the time change, light-emitting element E L not only, with the film of amorphous silicon as the operating characteristic of the thin film transistor (TFT) of element area also take place through the time change.Particularly under the situation of the thin film transistor (TFT) of N channel-type, mobility [mu] have through the time tendency that descends.Therefore, because the driving force of driving transistors Tr2 descends, even be applied to the level constant of the input signal on the grid, the drain current of supplying with light-emitting component also diminishes, and the danger that causes deterioration in brightness is arranged.Therefore, the present invention has improved image element circuit shown in Figure 6, has increased the compensate function of drive current.Below, describe the embodiment of image element circuit of the present invention in detail.Have, the image element circuit that this image element circuit can be used as display device shown in Figure 1 adds again.
Fig. 8 is the schematic circuit diagram of the embodiment of expression image element circuit of the present invention.For ease of understanding, for using corresponding reference marker as far as possible with the corresponding part of the image element circuit of relevant reference example shown in Figure 6.As shown in the figure, this image element circuit 5 is configured on the cross section of sweep trace and signal wire, and signal wire DL is 1, but sweep trace is 3 bunchys such as WS, X, Y and is arranged in parallel.Image element circuit 5 is provided with electrooptic cell EL, driving transistors Tr2, sampling transistor Tr1 and keeps capacitor C 1 as basic inscape.Driving transistors Tr2 is made of the thin film transistor (TFT) of N channel-type, and its grid (G) is connected on the input node A, and its source electrode (S) is connected on the output node B, and its drain electrode is connected on the predetermined power source voltage Vcc.In addition, the grid voltage of driving transistors Tr2 represents that with Vgs drain current is represented with Ids.Electrooptic cell EL is made of the double ended type light-emitting component of organic EL etc., and the one utmost point in the Dragon Boat Festival is connected on the output node B, and other end negative electrode is connected on the predetermined cathode potential Vcath.Sampling transistor Tr1 is connected between input node A and the signal wire DL.The grid of sampling transistor Tr1 is connected on the sweep trace WS.Keep capacitor C 1 to be connected on the input node A.
In such structure, sampling transistor Tr1 time action in being scanned line selection, sampling are from the signal Vsig of signal wire DL input and remain on and keep on the electric capacity.Driving transistors Tr2 supplies with drive current (drain current Ids) according to remaining on the signal potential Vin that keeps on the capacitor C 1 to electrooptic cell EL.
As characteristic item of the present invention, image element circuit 5 be provided with in order to compensation follow driving transistors Tr2 through the time drive current (drain current Ids) that changes the compensating circuit 7 of decline.This compensating circuit 7 feeds back to input node A one side from the decline of output node B one side detection drive current (drain current Ids) with its result.Therefore,, also can add feedback and eliminate it even drain current descends by the time, so, although the driving force by the time of driving transistors Tr2 descends, after between long-term, still can guarantee drain current Ids with the initial stage same level.
Concrete structure as feedback, this compensating circuit 7 detects the voltage drop that produces at electrooptic cell EL with drain current Ids from output node B one side, the level of the level of comparator input signal Vsig and this voltage drop that detects is also obtained difference, will be added to corresponding to the current potential of difference to be maintained on the signal potential Vin that keeps on the capacitor C 1.After supplying, will produce voltage drop when overdriving electric current at optical element EL upper reaches, this voltage drop is proportional to the size of drive current.Thereby the variation of drive current is fallen and can be detected by monitor voltage.This detected voltage drop comes comparative evaluation with input signal Vsig as the reference level.Feed back to the decline that input node A one side is eliminated drain current Ids by result with this comparative evaluation.
As concrete structure, compensating circuit 7 has increased by 4 N channel-type thin film transistor (TFT)s by the image element circuit at reference example shown in Figure 6 and 1 capacity cell constitutes.That is compensating circuit 7 is by constituting with the lower part, and they are: be connected detection capacitor C 2 between output node B and the predetermined intermediate node C, be inserted in switching transistor Tr6 between intermediate node C and the signal wire DL, be inserted in switching transistor Tr3 between terminal node D that is connected to an end that keeps capacitor C 1 and the earthing potential Vss that is scheduled to, be inserted in the switching transistor Tr4 between terminal node D and the output node B and be inserted in terminal node D and intermediate node C between switching transistor Tr5.Wherein, switching transistor Tr4, Tr5, Tr6 are the transistor units that increases with the image element circuit comparison of reference example shown in Figure 6.
The grid of switching transistor Tr3 is connected on the sweep trace WS.The grid of switching transistor Tr4 is connected on the sweep trace X.The grid of switching transistor Tr5 is connected on the sweep trace Y.The grid of switching transistor Tr6 is connected on the sweep trace X.Hence one can see that, and sampling transistor Tr1 and switching transistor Tr3 do conducting, end control with same timing by common scanning line WS.In addition, switching transistor Tr4 and Tr6 also do conducting, end control with same timing by common scanning line X.Remaining switching transistor Tr5 does conducting, ends control with other timing by sweep trace Y and other switching transistor.
Describe the work of the image element circuit shown in Fig. 8 in detail with reference to the time diagram of Fig. 9.Illustrated time diagram is represented 1 (1f) beginning with timing T1, and T6 represents 1 end with timing.Along time shaft T, expression is applied to pulse ws on the sweep trace WS, be applied to pulse x on the sweep trace X, be applied to the waveform of the pulse y on the sweep trace Y.Moreover, along same time shaft, the potential change of input node A, intermediate node C and output node B is shown.The potential change of input node A and the potential change of output node B represent that with solid line for distinguishing, the potential change of intermediate node C dots.
Timing T0 before entering this, sweep trace WS and X are maintained at low level, and on the other hand, sweep trace Y is in high level.Thereby sampling transistor Tr1, switching transistor Tr3, Tr4 and Tr6 are for ending, and only switching transistor Tr5 is in conducting state.At this moment, shown in time diagram, owing between the current potential of the current potential of input node A and output node B the potential difference (PD) that is substantially equal to input current potential Vin is arranged, driving transistors Tr2 is in conducting state, supplies with drive current (drain current) Ids to light-emitting element E L.
In case enter this, at timing T1, sweep trace Y switches to low level.So switching transistor Tr5 ends.At timing T1, switching transistor Tr3 and Tr4 also become and end.Thereby, keep the terminal node D of capacitor C 1 to constitute high impedance, but, continue luminous because the current potential of input node A is continued to keep.In the work of timing T1, be equivalent to preparation for the sampling of the input signal in this.
Next, one reaches regularly T2, in fact just carries out the sampling (signal writes) of input signal Vsig.That is strobe pulse ws is applied on the sweep trace WS, and strobe pulse x is applied on the sweep trace X.As a result, sweep trace WS and sweep trace X are converted to high level jointly.Therefore, in the time of sampling transistor Tr1 conducting, also conducting of switching transistor Tr3.In addition, also conducting of switching transistor Tr4 and Tr6.As a result, when the terminal node D of maintenance capacitor C 1 was left behind to earthing potential Vss, output node B also dropped to earth level Vss rapidly.Simultaneously, by being converted to the sampling transistor Tr1 of conducting state, and resample input signal Vsig to keeping on the capacitor C 1 from signal wire DL.As a result, signal potential Vin is written to and keeps on the capacitor C 1.In other words, the output node B that will be in earthing potential Vss is as benchmark, and the current potential of input node A becomes Vin.
If through being dispensed on 1 horizontal period (1H) that writes of input signal, then remove strobe pulse ws at timing T3, sweep trace WS is back to low level.So when ending owing to sampling transistor Tr1, switching transistor Tr3 also ends, keep the terminal node D of capacitor C 1 to disconnect from earthing potential Vss.Replace switching transistor Tr4 and continue conducting, therefore keep the terminal node D of capacitor C 1 to be directly connected to output node B.Therefore, owing to apply signal potential Vin at (between input node A and the output node B) between the gate/source of driving transistors Tr2, therefore, drain current Ids flows into light-emitting element E L.Thereby light-emitting element E L is luminous in advance.
At timing T3, if drain current Ids flows to light-emitting element E L, then voltage drop Δ Ve1 produces, the rise amount of this part of the current potential of output node B.At this moment, because the bootstrapping action, the current potential of input node A is the amount of rising Δ Ve1 with the current potential interlock of output node B also.
Flow through light-emitting element E L simultaneously with drain current Ids, detect in the capacitor C 2 also inflow current, the current potential of an one terminal becomes Δ Ve1.The another terminal of this detection capacitor C 2 is connected to signal wire DL by intermediate node C and by the switching transistor Tr6 that is in conducting state.Thereby the current potential that detects the another terminal of capacitor C 2 roughly becomes Vin.Therefore, detecting the difference DELTA V μ=Δ Vin-Δ Ve1 that keeps both on the capacitor C 2.In the time diagram of Fig. 9, this difference DELTA V μ occurs as the potential difference (PD) between intermediate node C and the output node B.If the characteristic of driving transistors Tr2 through the time ground deterioration, its mobility [mu] diminishes, then drain current Ids also correspondingly diminishes.As a result, the last voltage drop Δ Ve1 that produces of light-emitting element E L diminishes.Thereby difference DELTA V μ is with under the situation of Vin as benchmark, and the value of difference DELTA V μ increases the part that Δ Ve1 reduces.That is, since driving transistors through the time deterioration, if drain current Ids reduces, the then reverse increase of difference DELTA V μ.By this difference DELTA V μ being fed back to input node A one side, can eliminate the decline of drain current Ids, remain on consistently with preliminary phase with value on.
Finish the back when arriving regularly T4 detecting of the sloping portion of drain current Ids, sweep trace X is converted to low level from high level.Thereby switching transistor Tr4 and Tr6 end.That is, keep the terminal node D of capacitor C 1 to disconnect from output node B.In addition, the intermediate node C that is connected to the terminal that detects capacitor C 2 also disconnects from signal wire DL.Thereby the preparation of main light emission action finishes.
Afterwards, when reaching regularly T5, sweep trace Y rises to high level from low level.Thereby, switching transistor Tr5 conducting, terminal node D directly is connected with intermediate node C.Thereby, between input node A and output node B, keep capacitor C 1 to constitute and be connected with detection capacitor C 2.Between input node A and output node B, apply and remain on the Vin on the C1 and add the Δ V μ that remains on the C2.Driving transistors Tr2 will supply with light-emitting element E L corresponding to the drain current Ids of Vin+ Δ V μ, the beginning main light emission.Owing to produce voltage drop on light-emitting element E L, output node B current potential rises.Interlock therewith, the current potential of input node A also rises.Because this bootstrapping action, the potential difference (PD) between input node A and the output node B is maintained on the value of Vin+ Δ V μ.As previously mentioned, because the deterioration of driving transistors Tr2, if drain current Ids descends, then Δ V μ increases and compensates it.By this feedback action, suppressed the change of drain current Ids, although the variation of the mobility [mu] of driving transistors Tr2 still can be flow through the drain current Ids with the initial stage same level.
Afterwards, when reaching regularly T6, sweep trace Y drops to low level, and main light emission finishes.As mentioned above, in this a succession of release, next beginning.
Figure 10 is the schematic circuit diagram of another embodiment of expression image element circuit of the present invention.For ease of understanding, for the corresponding part of image element circuit of reference example shown in Figure 6, adopt corresponding reference marker as far as possible.As shown in the figure, this image element circuit 5 is configured in the part that sweep trace and signal wire intersect.Signal wire DL is 1, and with 3 line bunchys such as sweep trace WS, X, Y and be arranged in parallel.As basic inscape, image element circuit 5 is provided with electrooptic cell EL, driving transistors Tr2, sampling transistor Tr1 and keeps capacitor C 1.Driving transistors Tr2 is made of the thin film transistor (TFT) of N channel-type, and its grid (G) is connected input node A, and its source electrode (S) is connected output node B, and its drain electrode is connected predetermined power supply potential Vcc.Have again, the gate voltage of driving transistors Tr2 is represented with Vgs, drain current is represented with Ids.Electrooptic cell EL is made of the double ended type light-emitting component of organic EL etc., and the one utmost point in the Dragon Boat Festival is connected output node B one side, and other end negative electrode connects predetermined cathode potential Vcath.Sampling transistor Tr1 is connected between input node A and the signal wire DL.The grid of sampling transistor Tr1 is connected on the sweep trace WS.Keep capacitor C 1 to be connected on the input node A.
In relevant structure, sampling transistor Tr1 is action when being scanned line WS and choosing, and sampling is from the input signal Vsig of signal wire DL and remain on and keep on the capacitor C 1.Driving transistors Tr2 supplies with drive current (drain current Ids) according to being maintained at the signal potential Vin that keeps on the capacitor C 1 to electrooptic cell EL.
As characteristic item of the present invention, image element circuit 5 be provided with in order to compensation follow driving transistors Tr2 through the time drive current (drain current Ids) that changes the compensating circuit of decline.This compensating circuit 7 is the decline that detects the drain current Ids of driving transistors Tr2 from output node B one side, its result is fed back to the circuit of input node A one side.With this purpose, compensating circuit 7 is provided with: will be done accumulating of certain hour and exported corresponding to the detecting unit that detects current potential of accumulating the quantity of electric charge by the electric charge of drain current Ids carrying; The level Vin of comparator input signal Vsig and this level that detects current potential are also obtained difference DELTA V μ, will be added to the feedback unit that is maintained on the signal potential Vin that keeps on the capacitor C 1 corresponding to the current potential of this difference.
Observe as can be known through concrete, this compensating circuit 7 is made of 6 transistor Tr 3～Tr8 and 2 capacitor C 2, C3.Switching transistor Tr8 is inserted between output node B and the electrooptic cell EL.Switching transistor Tr7 also is connected on the output node B.Detecting capacitor C 3 is connected between this switching transistor Tr7 and the earthing potential Vss that is scheduled to.Constitute the detecting unit of above-mentioned compensating circuit 7 by switching transistor Tr7, Tr8 and detection capacitor C 3.
Feedback capacity C2 is connected between output node B and the predetermined intermediate node C.Switching transistor Tr6 is inserted between intermediate node C and the signal wire DL.Switching transistor Tr3 is inserted between terminal node D that is connected to an end that keeps capacitor C 1 and the earthing potential Vss that is scheduled to.Switching transistor Tr4 is inserted between this terminal node D and the output node B.Switching transistor Tr5 is inserted between terminal node D and the intermediate node C.Feedback capacity C2 and switching transistor Tr5, Tr6 constitute the feedback unit of above-mentioned compensating circuit 7.
Have, the grid of switching transistor Tr3 is connected on the sweep trace WS again, and the grid of switching transistor Tr4, Tr6, Tr7 is connected on another sweep trace X, and switching transistor Tr5 and Tr8 are connected on another the sweep trace Y.
With reference to the time diagram of Figure 11, describe the action of the image element circuit shown in Figure 10 in detail.Illustrated time chart is shown in timing T1 and begins 1 (1f), finishes 1 at timing T6.Represented to be added in pulse ws on the sweep trace WS, be added in the pulse x on the sweep trace X and be added in the waveform of the pulse y on the sweep trace Y along time shaft.In addition, along same time shaft, represented the potential change of input node A, intermediate node C and output node B.The potential change of input node A and the potential change of output node B represent that with solid line the potential change of Qu Bie intermediate node C dots therewith.
Timing T0 before entering this, sweep trace WS and X remain on low level, and on the other hand, sweep trace Y is in high level.Thereby sampling transistor Tr1, switching transistor Tr3, Tr4, Tr6 and Tr7 become and end, and only switching transistor Tr5 and Tr8 are in conducting state.At this moment, shown in time diagram, owing between the current potential of the current potential of importing node A and output node B the potential difference (PD) that is substantially equal to Vin is arranged, driving transistors Tr2 is in conducting state, supplies with drive current (drain current) Ids to light-emitting element E L.
In case enter this, at timing T1, sweep trace Y switches to low level.Therefore, switching transistor Tr5 and Tr8 end.Because light-emitting element E L disconnects from output node B, becomes non-luminance.In addition, at timing T1, be connected switching transistor Tr3 on the switching transistor Tr5 and Tr4 and also be in and end.Therefore, keep the terminal node D of capacitor C 1 to constitute high impedance.The sampling of the input signal during this action in timing T1 is equivalent to for this is prepared.
When reaching regularly T2, be applied in strobe pulse ws on the sweep trace WS, also be applied in strobe pulse x on the sweep trace X.So sweep trace WS becomes high level, switching transistor Tr1 and Tr3 conducting.Simultaneously, because sweep trace X also becomes high level from low level, transistor Tr 4, Tr6 and Tr7 conducting.
Because switching transistor Tr3 conducting, terminal node D is connected to earthing potential Vss.In addition, because switching transistor Tr4 conducting, output node B is directly connected to terminal node D.Its result, the current potential of output node B drops to earthing potential Vss rapidly.At this moment, because also conducting of sampling transistor Tr1, the input signal Vsig that is supplied with by signal wire DL is written on the maintenance capacitor C 1.The size of the signal potential Vin that is write is substantially equal to the voltage of input signal Vsig.Because terminal node D is fixed on Vss, the current potential of input node A becomes Vin just shown in time diagram.Because this input current potential Vin is applied between the grid G and source S of driving transistors Tr2, from the drain current Ids of output node B outflow corresponding to signal potential Vin.
But, as mentioned above,, therefore continue to keep non-luminance because switching transistor Tr8 in cut-off state, can not supply with electrooptic cell EL.
When having passed through 1 horizontal period (1H) of distributing to the input signal write activity, remove strobe pulse ws at timing T3, sweep trace WS is back to low level by high level.Therefore, sampling transistor Tr1 and switching transistor Tr3 end.As a result, terminal node D and output node B disconnect from earthing potential Vss.Respond this action, the current potential of output node B begins to rise, and drain current Ids begins to flow to detection capacitor C 3 by the switching transistor Tr7 that is in conducting state.In the time of the accumulating of electric charge, the current potential of output node B continues to rise.At this moment, because terminal node D disconnects from earthing potential, the current potential of input node A also rises with the current potential interlock of output node B, and it is constant that potential difference (PD) Vin between the two keeps.
From the timing T4 of timing T3 behind preset time t, strobe pulse x is disengaged, and sweep trace X turns back to low level from high level.So transistor Tr 4, Tr7, Tr6 end.In stage after switching transistor Tr7 ends, the electric charge accumulation that detects capacitor C 3 finishes.Current potential corresponding to the detection capacitor C 3 of accumulating electric charge is provided by formula Δ VC3=(Ids/C3) t.From this formula as can be known, because capacitance C3 and accumulate time t and fix detects current potential Δ VC3 and is proportional to drain current Ids, that is, detect the value that current potential Δ VC3 becomes the drain current Ids that is proportional to driving transistors Tr2.Mobility [mu] decline at driving transistors Tr2 advances in time, detects current potential Δ VC3 and also correspondingly descends.
At timing T4, sweep trace X is before being about to drop to low level, and switching transistor Tr6 and Tr7 are in conducting state.Thereby intermediate node C one side of feedback capacity C2 becomes the current potential Vin of input signal Vsig.In addition, the current potential of output node B one side of feedback capacity C2 becomes Δ VC3 just.Thereby strobe pulse x is disengaged, and in the moment that switching transistor Tr6 and Tr7 have been cut off, feedback capacity C2 goes up the current potential Δ V μ that keeps corresponding to the difference of Vin and Δ VC3.That is, represent with formula Δ V μ=Vin-Δ VC3.As previously mentioned, because the deterioration of driving transistors Tr2, in case drain current Ids descends, then Δ VC3 also descends.Thereby Δ V μ increases, and feeds back to input node A one side by the current potential Δ V μ that will remain on the feedback capacity C2, can eliminate the decline of drain current Ids.Because this feedback action,, also can continue to supply with drain current Ids with the initial stage same level even driving transistors Tr2 produces the operating characteristic deterioration of mobility etc.
In the present invention, the signal potential Vin of input signal Vsig as benchmark, is compared to determine the size that detects current potential Δ VC3.Signal potential Vin (for example changes in 0～5V), also changes corresponding to its drain current, become the level corresponding with Δ VC3 in predetermined scope.Like this, because Vin and the equidirectional variation of Δ VC3 can dynamically be compared.As its prerequisite, be necessary the dynamic range of Vin is roughly alignd with the dynamic range of Δ VC3.If the dynamic range of Vin is above-mentioned 0～5V, then ideal situation is, Δ VC3 also roughly changes in the scope of 0～5V.For the dynamic range with Δ VC3 is adjusted to the scope of hope, be necessary suitably to set the capacity of accumulating time t and detecting capacitor C 3.
Afterwards, proceed to regularly T5, apply strobe pulse y, sweep trace Y switches to high level from low level.So, switching transistor Tr5 and Tr8 conducting.Because switching transistor Tr8 conducting, the anode of electrooptic cell EL is directly connected to output node B.In addition, because switching transistor Tr5 conducting, intermediate node C is connected directly on the terminal node D.Between input node A and output node B, apply the Vin that remains on the C1, and add the Δ V μ that is maintained on the C2.Driving transistors Tr2 will supply with light-emitting element E L corresponding to the drain current Ids of Vin+ Δ V μ, begin luminous.Produce voltage drop because light-emitting element E L goes up, the current potential of output node B rises.Interlock with it, the current potential of input node A also rises.Because this bootstrapping action, the potential difference (PD) between input node A and the output node B is maintained on the value of Vin+ Δ V μ.As mentioned above, in case because the deterioration of driving transistors Tr2, drain current descends, and Δ V μ just change compensates it greatly.Because this feedback action, the change of drain current Ids is suppressed, and can irrespectively flow through the drain current Ids with the initial stage same level with the mobility change of driving transistors Tr2.
Afterwards, when reaching regularly T6, sweep trace Y drops to low level, and switching transistor Tr8 ends, luminous end.By above-mentioned action, in this a succession of release, next beginning.
Figure 12 is the schematic circuit diagram of another embodiment of expression image element circuit of the present invention.For ease of understanding, just with the corresponding part of image element circuit of relevant reference example shown in Figure 6, the reference marker of employing correspondence as far as possible.As shown in the figure, this image element circuit 5 is configured on sweep trace and the signal wire cross section.Signal wire DL is 1,3 line bunchys such as sweep trace WS, X, Y and being arranged in parallel.As basic inscape, image element circuit 5 is provided with: electrooptic cell EL, driving transistors Tr2, sampling transistor Tr1 and maintenance capacitor C 1.Driving transistors Tr2 is made of the thin film transistor (TFT) of N channel-type, and its grid (G) is connected on the input node A, and its source electrode (S) is connected on the output node B, and its drain electrode downlink connection is on predetermined power supply potential Vcc.In addition, the gate voltage of driving transistors Tr2 represents that with Vgs drain current is represented with Ids.Electrooptic cell EL is made of the double ended type light-emitting component of organic EL etc., and the one utmost point in the Dragon Boat Festival is connected output node B one side, and other end negative electrode is connected on the predetermined cathode potential Vcath.Sampling transistor Tr1 is connected between input node A and the signal wire DL, and the grid of sampling transistor Tr1 is connected on the sweep trace WS.Keep capacitor C 1 to be connected on the input node A.
In relevant structure, sampling transistor Tr1 time action in being scanned line selection, from signal wire DL to input signal Vsig sampling and remain on and keep on the capacitor C 1.Driving transistors Tr2 supplies with drive current (drain current Ids) according to remaining on the signal potential Vin that keeps on the capacitor C 1 to electrooptic cell EL.
As characteristic item of the present invention, image element circuit 5 be provided with in order to compensation follow driving transistors Tr2 through the time drive current (drain current Ids) that changes the compensating circuit 7 of decline.This compensating circuit 7 detects the decline of drain current Ids from output node B one side.For its result being fed back to input node A one side, be provided with detecting unit and feedback unit.Detecting unit has from the voltage drop that is inserted in the resistance components between output node B and the predetermined earthing potential Vss and this resistance components produced according to the drain current Ids that flows into earthing potential Vss from output node B as the capacitive component that detects the current potential maintenance.In addition, the level Vin of feedback unit comparator input signal Vsig with detect the level of current potential and obtain difference DELTA V μ, will be added to corresponding to the current potential of this difference and remain on the signal potential Vin that keeps on the capacitor C 1.
Observe as can be known through concrete, compensating circuit 7 shown in Figure 12 is made of 2 capacity cell C2, C3 and 7 transistor Tr 3～Tr9.Switching transistor Tr8 is inserted between the anode of output node B and electrooptic cell EL.Switching transistor Tr7 is connected on the same output node B.Transistor Tr 9 diode between this switching transistor Tr7 and predetermined earthing potential Vss is connected, plays the transistorized function of detection.Capacity cell C3 is connected in parallel with detecting transistor Tr 9, works the function that detects electric capacity.This detection transistor Tr 9 that is connected by diode is equivalent to be arranged on the resistance components on the detecting unit of compensating circuit 7, detects the capacitive component that capacitor C 3 is equivalent to be arranged on the detecting unit of same compensating circuit 7.
Another capacity cell C2 is connected between output node B and the predetermined intermediate node C, constitutes feedback capacity.Switching transistor Tr6 is inserted between intermediate node C and the signal wire DL.Switching transistor Tr3 is inserted in and is connected between terminal node D that keeps capacitor C 1 one ends and the earthing potential Vss that is scheduled to.Switching transistor Tr4 is inserted between terminal node D and the output node B.Switching transistor Tr5 is inserted between terminal node D and the intermediate node C.
In addition, the grid of switching transistor Tr3 and switching transistor Tr1 are connected in same sweep trace WS.Switching transistor Tr4, Tr6, Tr7 are connected in sweep trace X jointly.The grid of switching transistor Tr5 and Tr8 is connected in sweep trace Y.
With reference to the time diagram of Figure 13, describe the action of the image element circuit shown in Figure 12 in detail.Illustrated time chart is shown in timing T1 and begins 1 (1f), finishes 1 at timing T6.Along time shaft, expression is applied to pulse ws on the sweep trace WS, be applied to pulse x on the sweep trace X, be applied to the waveform of the pulse y on the sweep trace Y.Moreover, along same time shaft, represented the potential change of input node A, intermediate node C and output node B.The potential change of input node A and the potential change of output node B represent that with solid line the potential change of Qu Bie intermediate node C dots with it.
Timing T0 before entering this, sweep trace WS and X are maintained at low level, and on the other hand, sweep trace Y is in high level.Thereby sampling transistor Tr1, switching transistor Tr3, Tr4, Tr6, Tr7 are in and end, and only switching transistor Tr5 and Tr8 are in conducting state.At this moment, shown in time diagram, owing between the current potential of the current potential of importing node A and output node B the current potential that is substantially equal to Vin is arranged, driving transistors Tr2 is in conducting state, supplies with drive current (drain current) Ids to light-emitting element E L.
In case enter this, at timing T1, sweep trace Y is switched to low level.So switching transistor Tr5 and Tr8 end.Thereby, because light-emitting element E L disconnects from output node B, be in non-luminance.In addition, at timing T1, be connected switching transistor Tr3 on the switching transistor Tr5 and Tr4 and also be in and end.Thereby, keep the terminal node D of capacitor C 1 to constitute high impedance.The sampling of the input signal in this action of timing T1 is equivalent to for this is prepared.
One arrives regularly T2, just is applied in strobe pulse ws on the sweep trace WS, also is applied in strobe pulse x on sweep trace X.So sweep trace WS becomes high level, switching transistor Tr1 and Tr3 conducting.Simultaneously, because sweep trace X also becomes high level from low level, transistor Tr 4, Tr6 and Tr7 conducting.
Because switching transistor Tr3 conducting, terminal node D is connected to earthing potential Vss.Moreover because switching transistor Tr4 conducting, output node B is directly connected on the terminal node D, the result, and the current potential of output node B drops to earthing potential Vss rapidly.At this moment, because also conducting of sampling transistor Tr1, the input signal Vsig that is supplied with by signal wire DL is written on the maintenance capacitor C 1.The size of the signal potential Vin that is write is substantially equal to the voltage of input signal Vsig.Because terminal node D is fixed on the Vss, the current potential of input node A is Vin shown in time diagram just.Because this input current potential Vin is added between the grid G and source S of driving transistors Tr2, flow out from output node B corresponding to the drain current Ids of signal potential Vin.
But, because transistor Tr 8 in cut-off state, is not supplied to electric current on the electrooptic cell EL, continue to keep non-luminance as above-mentioned.
If process is assigned to 1 horizontal period (1H) of the write activity of input signal, ws is disengaged at timing T3 strobe pulse, and sweep trace WS becomes low level.So when the sampling transistor Tr1 of N channel-type ended, switching transistor Tr3 also ended.Its result, input node A disconnects from signal wire DL, becomes high impedance status.In addition, terminal node D and output node B disconnect from earthing potential Vss under interconnective state.Respond this action, because driving transistors Tr2 begins to make drain current Ids to flow through according to the signal potential Vin that is applied between its grid G and the source S, the current potential of output node B rises.Interlock with it, the current potential of input node A this part the amount of Vin that also rises just.At this moment, because switching transistor Tr8 keeps cut-off state, drain current Ids can not flow into electrooptic cell EL, still keeps non-luminance.But because switching transistor Tr7 is in conducting state, drain current Ids flows to earthing potential Vss from output node B by switching transistor Tr7 and Tr9.In case on the detection transistor that constitutes by the transistor Tr 9 that is connected by diode, flow through drain current Ids, will produce corresponding to its big or small voltage drop Δ VTr9.This voltage sloping portion Δ VTr9 is as detecting the two ends that current potential is sampled to capacitor C 3.Because under the state of switching transistor Tr7 conducting, output node B is connected to and detects on the capacitor C 3, the current potential of output node B becomes the level of Δ VTr9 shown in time diagram.
On the other hand, because sampling transistor Tr6 also is in conducting, intermediate node C is connected to signal wire DL.As a result, the intermediate node C that is positioned at the left side of feedback capacity C2 becomes the signal potential Vin of input signal Vsig.On the other hand, the output node B on the right side of feedback capacity C2 such as the above-mentioned current potential that becomes Δ VTr9.Thereby, in the potential difference (PD) of the two ends of feedback capacity C2 generation Δ V μ=Vin-Δ VTr9.So, the level Vin of feedback capacity C2 comparator input signal Vsig and above-mentionedly detect the level of current potential Δ VTr9 and draw difference.Δ VTr9 is the voltage drop part that is produced by drain current Ids.Thereby, driving transistors Tr2 through the time during deterioration, if declines such as its mobilities, drain current Ids reduces, then Δ VTr9 also reduces.In case Δ VTr9 reduces, the then reverse increase of Δ V μ.By this Δ V μ being fed back to input node A one side, can eliminate the decline of drain current Ids.Even since driving transistors Tr2 through the time change the supply capacity cause drain current Ids and descend because this feedback action also can be guaranteed the drive current with initial drain current same level.
Afterwards, one reaches regularly T4, and strobe pulse x just is disengaged, and sweep trace X becomes low level.So switching transistor Tr4, Tr6, Tr7 end.Feedback capacity C2 disconnects from signal wire DL and earthing potential Vss, keeps above-mentioned difference DELTA V μ simultaneously.
Afterwards, one enters regularly T5, just applies strobe pulse y, and sweep trace Y switches to high level from low level.So, switching transistor Tr5 and Tr8 conducting.Because switching transistor Tr8 conducting, the anode of electrooptic cell EL is directly connected in output node B.In addition, because switching transistor Tr5 conducting, intermediate node C is directly connected in terminal node D.Between input node A and output node B, apply the Vin that remains on the C1, and add the Δ V μ that remains on the C2.Driving transistors Tr2 begins luminous to the drain current Ids of light-emitting element E L supply corresponding to Vin+ Δ μ.Owing to produce voltage drop on light-emitting element E L, the current potential of output node B rises.Interlock with it, the current potential of input node A also rises.Because this bootstrapping action, the potential difference (PD) between input node A and the output node B keeps the value of Vin+ Δ V μ.As mentioned above, if because the deterioration of driving transistors Tr2, drain current Ids descends, and then increases Δ V μ and compensates it.Because this feedback action, suppressed the change of drain current Ids, can irrespectively flow through drive current with the initial stage same level with the variation of the mobility [mu] of driving transistors Tr2.
Afterwards, when proceeding to regularly T6, sweep trace Y drops to low level, and switching transistor Tr8 ends, luminous end.Thus, this a succession of release, next beginning simultaneously.
Like this, compensating circuit of the present invention adopts and is provided with according to being inserted in the resistance components between output node and the earthing potential and flowing to the drive current of earthing potential from output node, with the voltage drop that produces on the resistance components detecting unit as the capacitive component that detects the current potential maintenance.Because be the mode that detects the voltage drop that produces on the resistance components, detection itself can be finished with the short time, regularly tolerance limit (timing margin) is abundant.To this, also can adopt by drive current the electric charge of carrying is done accumulating of certain hour, output is corresponding to the detecting unit that detects current potential of accumulating the quantity of electric charge.But, utilize corresponding to the mode that detects current potential of accumulating the quantity of electric charge, owing to need preset time, in whole order, the regularly possibility of tolerance limit of compression is arranged to accumulating electric charge.For relatively, illustrate that with reference to following Figure 10 and Figure 11 utilization is corresponding to the mode that detects current potential of accumulating the quantity of electric charge.
Figure 10 is the schematic circuit diagram of embodiment of the image element circuit of expression comparative example.For ease of understanding,, use corresponding reference marker as far as possible for the part corresponding with image element circuit of the present invention shown in Figure 12.As shown in the figure, this image element circuit 5 is configured on sweep trace and the signal wire cross section.Signal wire DL is 1, but sweep trace is that 3 bunchys such as WS, X, Y are arranged in parallel.Image element circuit 5 is provided with electrooptic cell EL, driving transistors Tr2, sampling transistor Tr1 and keeps capacitor C 1 as basic inscape.Driving transistors Tr2 is made of the thin film transistor (TFT) of N channel-type, and its grid (G) is connected input node A, and its source electrode (S) is connected output node B, and its drain electrode is connected on the predetermined power source voltage Vcc.In addition, the gate voltage of driving transistors Tr2 is represented with Vgs drain current represents that with Ids electrooptic cell EL is made of the double ended type element of organic EL etc., the one utmost point in the Dragon Boat Festival is connected output node B one side, and other end negative electrode is connected predetermined cathode potential Vcath.Sampling transistor Tr1 is connected between input node A and the signal wire DL.The grid of sampling transistor Tr1 is connected sweep trace WS.Keep capacitor C 1 to be connected input node A.
In relevant structure, sampling transistor Tr1 is action when being scanned line WS and choosing, from signal wire DL to input signal Vsig sampling and remain on and keep on the capacitor C 1.Driving transistors Tr2 supplies with drive current (drain current Ids) according to being maintained at the current potential Vin that keeps on the capacitor C 1 to electrooptic cell EL.
Characteristic item as a comparative example, image element circuit 5 be provided with in order to compensation follow driving transistors Tr2 through the time drive current (drain current Ids) that changes the compensating circuit 7 of decline.This compensating circuit 7 is the decline that detects the drain current Ids of driving transistors Tr2 from output node B one side, its result is fed back to the circuit of input node A one side.With regard to this purpose, compensating circuit 7 is provided with: will be done accumulating of certain hour and exported corresponding to the detecting unit that detects current potential of accumulating the quantity of electric charge by the electric charge of drain current Ids carrying; The level Vin of comparator input signal Vsig and this level that detects current potential are also obtained difference DELTA V μ, will be added to the feedback unit that is maintained on the signal potential Vin that keeps on the capacitor C 1 corresponding to the current potential of this difference.
Observe as can be known through concrete, this compensating circuit 7 is made of 6 transistor Tr 3～Tr8 and 2 capacitor C 2, C3.Switching transistor Tr8 is inserted between output node B and the electrooptic cell EL.Switching transistor Tr7 also is connected on the output node B.Detecting capacitor C 3 is connected between this switching transistor Tr7 and the earthing potential Vss that is scheduled to.Constitute the detecting unit of above-mentioned compensating circuit 7 by switching transistor Tr7, Tr8 and detection capacitor C 3.
Feedback capacity C2 is connected between output node B and the predetermined intermediate node C.Switching transistor Tr6 is inserted between intermediate node C and the signal wire DL.Switching transistor Tr3 is inserted between terminal node D that is connected in an end that keeps capacitor C 1 and the earthing potential Vss that is scheduled to.Switching transistor Tr4 is inserted between this terminal node D and the output node B.Switching transistor Tr5 is inserted between terminal node D and the intermediate node C.Feedback capacity C2 and switching transistor Tr5, Tr6 constitute the feedback unit of above-mentioned compensating circuit 7.
Have, the grid of switching transistor Tr3 is connected in sweep trace WS again, and the grid of switching transistor Tr4, Tr6, Tr7 is connected in another root sweep trace X, and switching transistor Tr5 and Tr8 are connected to another root sweep trace Y.
With reference to the time diagram of Figure 11, describe the action of the image element circuit shown in Figure 10 in detail.Illustrated time chart is shown in regularly T1,1 (1f) beginning; At timing T6,1 end.Along time shaft, show the pulse ws that is added on the sweep trace WS, be added in the pulse x on the sweep trace X and be added in the waveform of the pulse y on the sweep trace Y.In addition, along same time shaft, represented the potential change of input node A, intermediate node C and output node B.The potential change of input node A and the potential change of output node B represent with solid line, for the potential change of the intermediate node C of difference therewith dots.
Timing T0 before entering this, sweep trace WS and X remain on low level, and on the other hand, sweep trace Y is in high level.Thereby sampling transistor Tr1, switching transistor Tr3, Tr4, Tr6 and Tr7 are in and end, and only switching transistor Tr5 and Tr8 are in conducting state.At this moment, shown in time diagram, owing between the current potential of the current potential of importing node A and output node B the potential difference (PD) that is substantially equal to Vin is arranged, transistor Tr 2 is in conducting state, supplies with drive current (drain current) Ids to light-emitting element E L.
One enters this, and sweep trace Y just switches to low level at timing T1.So switching transistor Tr5 and Tr8 end.Thereby, because light-emitting element E L disconnects from output node B, become non-luminance.In addition, at timing T1, the switching transistor Tr3 and the Tr4 that are connected on the switching transistor Tr5 also end.Therefore, keep the terminal node D of capacitor C 1 to constitute high impedance.The sampling of the input signal during this action in timing T1 is equivalent to for this is prepared.
To timing T2, be applied in strobe pulse ws on the sweep trace WS, sweep trace X also is applied in strobe pulse x.So sweep trace WS becomes high level, switching transistor Tr1 and Tr3 conducting.Simultaneously, because sweep trace X also becomes high level from low level, transistor Tr 4, Tr6, Tr7 conducting.
Because switching transistor Tr3 conducting, terminal connections D is connected in earthing potential Vss.In addition, because switching transistor Tr4 conducting, output node B is directly connected to terminal connections D.As a result, the current potential of output node B drops to earthing potential Vss rapidly.At this moment, because also conducting of sampling transistor Tr1, the input signal Vsin that is supplied with by signal wire DL is written on the maintenance capacitor C 1.The size of the signal potential Vin that is write is substantially equal to the voltage of input signal Vsig.Because terminal node D is fixed on Vss, the current potential of input node A becomes Vin just shown in time diagram.Because this input current potential Vin is applied between the grid G and source S of driving transistors Tr2, Id flows out from output node B corresponding to signal potential Vin drain current.
But, as previously mentioned,, continue to keep non-luminance because switching transistor Tr8 in cut-off state, can not be supplied to electric current on the electrooptic cell EL.
Passed through 1 horizontal period (1H) on the write activity that is assigned to input signal, at timing T3, strobe pulse is disengaged, and sweep trace WS is back to low level from high level.So sampling transistor Tr1 and switching transistor Tr3 end.As a result, terminal node D and output node B disconnect from earthing potential Vss.Respond this action, the current potential of output node B begins to rise, and drain current Ids begins to flow into detection capacitor C 3 by the switching transistor Tr7 that is in conducting state.Along with accumulating of electric charge, the current potential of output node B continues to rise.At this moment, because terminal node D disconnects from earthing potential Vss, the current potential of input node A also interlock rises in the current potential of output node B, and it is constant that potential difference (PD) Vin between the two keeps.
At the timing T4 after timing T3 process schedule time t, strobe pulse x is disengaged, and sweep trace X is back to low level from high level.So transistor Tr 4, Tr7, Tr6 end.In the stage of switching transistor Tr7 after ending, the electric charge accumulation that detects capacitor C 3 finishes.Current potential corresponding to the detection capacitor C 3 of accumulating electric charge is provided by formula Δ VC3=(Ids/C3) t.From then on formula as can be known because capacitance C3 and accumulate time t and fix detects current potential Δ VC and is proportional to drain current Ids.That is detecting current potential Δ VC3 is the value that is proportional to the drain current Ids of driving transistors Tr2.The decline that drives the mobility of moving transistor Tr 2 advances in time, detects current potential Δ VC3 and also descends correspondingly.
At timing T4, before sweep trace X was about to drop to low level, switching transistor Tr6 and Tr7 were in conducting state.Thereby intermediate node C one side of feedback capacity C2 is in the current potential Vin of input signal Vsig.In addition, the current potential of output node B one side of feedback capacity C2 is Δ VC3 just.Therefore, in the moment that the switching transistor Tr6 that is disengaged at strobe pulse x and Tr7 have been cut off, on feedback capacity C2, maintain current potential Δ V μ corresponding to the difference of Vin and Δ VC3.That is, represent with Δ V μ=Vin-Δ VC3.As previously mentioned, if because the deterioration of driving transistors Tr2, drain current Ids descends, and then Δ VC3 also descends, thereby Δ V μ increases.Feed back to input node A one side by the current potential Δ V μ that will remain on the electric C2 of feedback, can eliminate the decline of drain current Ids.Because this feedback action,, also can continue to supply with drain current Ids with the initial stage same level even driving transistors Tr2 produces deterioration on the operating characteristic of mobility etc.
In this comparative example, the signal potential Vin of input signal Vsig is compared to determine the size that detects current potential Δ VC3 as benchmark.Signal potential Vin is (for example 0～5V) change in predetermined scope.Correspondingly, drain current Ids also changes, and Δ VC3 also becomes corresponding level.Like this, because Vin and the equidirectional variation of Δ VC3 can be compared dynamically.As its prerequisite, the dynamic range of Vin of need roughly aliging and the dynamic range of Δ VC3.Ideal situation is that if the dynamic range of Vin is aforesaid 0～5V, then Δ VC3 also roughly changes in the scope of 0～5V.For the dynamic range with Δ VC3 places the scope of hope, must suitably set the capacity of accumulating time t and detecting capacitor C 3.
When entering regularly T5 afterwards, strobe pulse y is applied in, and sweep trace Y switches to high level from low level.So, switching transistor Tr5 and Tr8 conducting.Because switching transistor Tr8 conducting, the anode of electrooptic cell EL is directly connected in output node B.In addition, because switching transistor Tr5 conducting, intermediate node C is directly connected in terminal node D.Between input node A and output node B, be added with the Vin that is maintained on the C1, and add the Δ V μ that is maintained on the C2.Driving transistors Tr2 will supply with light-emitting element E L corresponding to the drain current Ids of Vin+ Δ V μ, begin luminous.Produce voltage drop because light-emitting element E L goes up, the current potential of output node B rises.Interlock with it, the current potential of input node A also rises.Because this bootstrapping action, the potential difference (PD) between input node A and the output node B is maintained on the value of Vin+ Δ V μ.As previously mentioned, if because the deterioration of driving transistors Tr2, drain current Ids descends, and then Δ V μ change compensates it greatly.Because this feedback action has suppressed the change of drain current Ids.Can change the drain current Ids that irrespectively flows through with the initial stage same level with the mobility [mu] of driving transistors Tr2.
Afterwards, to timing T6, sweep trace Y drops to low level, and switching transistor Tr8 ends, luminous end.Thus, this a succession of release, next beginning simultaneously.
Figure 14 is the schematic circuit diagram of another embodiment of expression image element circuit of the present invention.For ease of understanding,, adopt the reference marker of correspondence as far as possible with the corresponding part of image element circuit of relevant reference example shown in Figure 6.As shown in the figure, this image element circuit 5 is configured on sweep trace and the signal wire cross section, and signal wire DL is 1, and with 4 bunchys such as sweep trace WS, X, Y and Z and be arranged in parallel.As the basic inscape of image element circuit 5, be provided with: light-emitting element E L, driving transistors Tr2, sampling transistor Tr1 and keep capacitor C s.The grid G of driving transistors Tr2 is connected on the input node A, and its source electrode is connected on the output node B, and its drain electrode is connected on the predetermined power supply potential Vcc.Light-emitting element E L is a diode-type two-terminal element such as organic EL for example, and the one utmost point in the Dragon Boat Festival is connected on the output node B, and other end negative electrode is connected on the predetermined current potential Vcath.Sampling transistor Tr1 is connected between input node A and the signal wire DL, and its grid is connected on the sweep trace WS.Keep capacitor C s to be connected on the input node A.In dependency structure, sampling transistor Tr1 is action when being scanned line WS and choosing, and remains on after to input signal Vsig sampling from signal wire DL to keep on the capacitor C s.Driving transistors Tr2 supplies with drive current according to remaining on the signal potential that keeps on the capacitor C s to light-emitting element E L.As shown in the figure, driving transistors Tr2 supplies with light-emitting element E L with it as drive current from output node B output drain current Ids.Light-emitting element E L follows the voltage drop that is produced by drive current Ids luminous.
As characteristic item of the present invention, added in the image element circuit 5 in order to compensation since light-emitting element E L through the time change the compensating circuit 7 that the brightness cause descends.This compensating circuit 7 will corresponding to light-emitting element E L through the time change and the voltage drop that increases detects from output node B one side, will feed back to input node A one side corresponding to the signal potential of the level of this detected voltage drop.Driving transistors Tr2 supplies with the drive current Ids that the brightness that is enough to compensate light-emitting element E L descends according to this signal potential that is fed.Like this, the present invention is conceived to following deterioration in brightness and the tendency of voltage drop increase as what light-emitting component generally was inclined to, utilizes it to compensate light-emitting component brightness by the time and descends.That is if deterioration in brightness advances, the voltage drop of light-emitting component inside increases.Feed back to input node one side by it is detected as signal voltage, thereby remedy deterioration in brightness.That is if deterioration in brightness advances, then voltage drop increases, and by it is fed back on the driving transistors, drive current is increased.The increase of this drive current is worked remedying on the direction of deterioration in brightness usually.
As concrete structure, compensating circuit 7 detects capacitor C 1, C2 and 5 switching transistor Tr3 to Tr7 by 2 and constitutes.2 detection capacitor C 1, C2 are connected in series between output node B and the input node A.Among the figure, 2 interlinkages that detect capacitor C 1, C2 are represented with intermediate node C.Be connected in series 2 detect capacitor C 1, C2 from output node B one side detect keep in voltage drop that light-emitting element E L produces and by each self-capacity ratio of division in, that part of voltage decline level that is held in place on the detection capacitor C 2 of input node A one side is fed back to input node A one side as signal potential.
In order to make 2 to detect capacitor C 1, C2 action by said sequence, disposed 5 switching transistor Tr3 to Tr7, do conducting, end control with corresponding scanning line.Observe as can be known through concrete, switching transistor Tr5 inserts in parallel with a detection capacitor C 1 that is positioned at output node B one side among 2 detection electric capacity that are connected in series.In other words, switching transistor Tr5 is connected between output node B and the intermediate node C, and its grid is connected on the sweep trace Y.Switching transistor Tr7 is inserted at another of input node A one side and detects between capacitor C 2 and the predetermined earthing potential Vss, and its grid is connected on the sweep trace X.Switching transistor Tr6 is inserted between another detection capacitor C 2 of same input node A one side and input node A, and its grid connects on the ground sweep trace Y.Switching transistor Tr3 is inserted between the earthing potential Vss that keeps capacitor C s and be scheduled to, and its grid is connected on the sweep trace Z, and remaining switching transistor Tr4 is inserted in and keeps between capacitor C s and the output node B, and its grid is connected in sweep trace X.
With reference to the time diagram of Figure 15, describe the image element circuit shown in Fig. 8 in detail.Illustrated time chart is shown in regularly T1,1 (1f) beginning; At timing T6,1 end.Along time shaft T, expression is added in pulse ws on the sweep trace WS, be added in pulse x on the sweep trace X, be added in the pulse y on the sweep trace Y and be added in the waveform of the pulse z on the sweep trace Z.In addition, on same time shaft, represented the potential change of input node A, intermediate node C and output node B.The potential change of input node A and the potential change of intermediate node C are represented with solid line, are difference therewith, and the potential change of output node B dots.Timing T0 before entering this, sweep trace WS, Z, X are in low level, and on the other hand, sweep trace Y is in noble potential.Thereby sampling transistor Tr1 and switching transistor Tr3, Tr4, Tr7 are in cut-off state, and on the other hand, switching transistor Tr5 and Tr6 are in conducting state.
When the above-mentioned state of previous field enters this, rise to high level from low level at timing T1 sweep trace Z and X.So owing to switching transistor Tr3, Tr4, also conducting of Tr7, the switching transistor Tr3 to Tr7 that comprises in the image element circuit 5 all becomes conducting.Thereby, the whole short circuits of each terminal that keep capacitor C s and detection capacitor C 1, C2, the electric charge that is recharged at previous field is all discharged.Thereby, in the moment of timing T1, keep the electric charge of capacitor C s and detection capacitor C 1, C2 to be eliminated, for the new element of preparing this is resetted.
In addition, because all transistor Tr 3 to Tr7 conductings, input node A, output node B and intermediate node C drop into earthing potential Vss.Because the potential difference (PD) between input node A and the output node B is 0, does not flow through drain current Ids on the driving transistors Tr2, light-emitting element E L is in non-luminance.
Advance to regularly T ' slightly from the timing T1 time, sweep trace Y switches to low level from high level, and switching transistor Tr5 and Tr6 end.Thereby the detection capacitor C 1 that is connected in series, C2 disconnect from input node A, thereafter, become and carry out the holding state that voltage drop detects.
Arrive regularly T2, applied strobe pulse ws by sweep trace WS, sampling transistor Tr1 conducting.So the input signal Vsig that is supplied with from signal wire DL is sampled on the maintenance capacitor C s, signal potential Vin is maintained at and keeps on the capacitor C s.That is the current potential of input node A is benchmark with the earthing potential, becomes signal potential Vin just.Apply signal potential Vin between input node A and output node B, correspondingly, driving transistors Tr2 begins to flow through drain current Ids.
Through distributing to 1 horizontal period (1H) of input signal Vsig sampling, ws is disengaged at timing T3 strobe pulse, and sampling transistor Tr1 turns back to cut-off state.Meanwhile, because sweep trace Z switches to low level from high level, switching transistor Tr3 ends, and keeps capacitor C s and output node B to disconnect from earthing potential Vss.The drain current Ids that supplies with from driving transistors Tr2 flows into light-emitting element E L, correspondingly, produces voltage drop Δ Ve1.The current potential of output node B is with respect to the rise amount of this voltage drop Δ Ve1 part of earthing potential.At this moment, keep capacitor C s to disconnect from earthing potential Vss, because the bootstrapping action, the current potential of input node A also rises linkedly with the current potential of output node B.At this moment, because the bootstrapping action, the potential difference (PD) Vin of input node A and output node B keeps constant.
In the moment of timing T3, switching transistor Tr5 is in cut-off state, and on the other hand, switching transistor Tr7 is in conducting state.Thereby a pair of detection capacitor C 1, C2 are connected between output node B and the earthing potential Vss.The drain current Ids that supplies with from output node B also flows into the detection capacitor C 1 that is connected in series, the C2, and the voltage drop part Δ Ve1 that appears at just on the output node B is maintained on 2 capacitor C 1, the C2 according to each self-capacity ratio of division.By the way, be maintained at the voltage drop part Δ V that detects on the capacitor C 2 by measure ratio of division be Δ V=Δ Ve1 * C1/ (C1+C2).This Δ V shows as the current potential to the intermediate node C of earthing potential Vss just on the time diagram of Fig. 9.Like this, because capacitive coupling is detecting the signal potential Δ V that has kept on the capacitor C 2 corresponding to the voltage drop Δ Ve1 of light-emitting element E L.
Then, one to timing T4, and sweep trace X just becomes low level once more, and switching transistor Tr4 and Tr7 end.As a result, keeping capacitor C s when output node B disconnects, detecting capacitor C 2 and also disconnect from earthing potential Vss.
Proceed to regularly T5 again, sweep trace Y switches to high level from low level, switching transistor Tr5 and Tr6 conducting.So, detect capacitor C 2 and directly be connected between output node B and the input node A.Thereby, remain on the signal potential Δ V that detects on the capacitor C 2 and be added between input node A and the output node B.Corresponding to this signal potential Δ V, driving transistors Tr2 supplies with drain current Ids to light-emitting element E L.Therefore light-emitting element E L becomes luminance, display image.Shown in the time diagram of Fig. 9, after timing T5, the signal potential Δ V that is applied is represented by Δ Ve1 * C1/ (C1+C2).As previously mentioned, in case the brightness of light-emitting element E L time dependent descends, voltage drop Ve1 just rises thereupon.Signal voltage Δ V coefficient C1/ (C1+C2) in proportion is proportional to Δ Ve1.By this signal voltage Δ V being fed back to input node A one side, drain current Ids increases the size that is equivalent to voltage drop Δ Ve1, plays the effect that compensation light-emitting element E L brightness descends.
Afterwards, one to T6 regularly, sweep trace Z and X just become high level once more, and next homing action is prepared in whole switching transistor Tr3 to Tr7 conductings.
Claims (28)
1. image element circuit is characterized in that:
Be configured on sweep trace and the signal wire cross section, be provided with electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity at least,
The grid of this driving transistors is connected the input node, and its source electrode is connected output node, and its drain electrode is connected on the predetermined power supply potential,
One end of this electrooptic cell is connected output node, and the other end is connected on the predetermined potential,
This sampling transistor is connected between this input node and this signal wire,
This maintenance electric capacity is connected on this input node,
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Supply with in the image element circuit of drive current to this electrooptic cell according to the signal potential that remains on this maintenance electric capacity at described driving transistors,
Be provided with compensation follow this driving transistors through the time drive current that the changes compensating circuit that descends,
Described compensating circuit detects the decline of this drive current from this output node side, and this result is fed back to this input node side.
2. image element circuit as claimed in claim 1, it is characterized in that: described compensating circuit detects the voltage drop that is produced at this electrooptic cell by this drive current from this output node side, relatively the level of the level of this input signal and this voltage drop that is detected and obtain difference will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.
3. image element circuit as claimed in claim 1, it is characterized in that: described compensating circuit is made of following element, and they are: be connected detection electric capacity between this output node and the predetermined intermediate node, be inserted in switching transistor between this intermediate node and this signal wire, be inserted in the terminal node of an end that is connected in this maintenance electric capacity and the earthing potential be scheduled between switching transistor, be inserted in the switching transistor between this terminal node and this output node and be inserted in this terminal node and this intermediate node between switching transistor.
4. display device is characterized in that:
Constitute by the sweep trace of row shape, the signal wire of row shape, the image element circuit that is configured on both cross sections separately,
Described image element circuit is provided with electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity at least,
The grid of this driving transistors is connected the input node, and its source electrode is connected output node, and its drain electrode is connected on the predetermined power supply potential,
One end of this electrooptic cell is connected output node, and the other end is connected on the predetermined potential,
This sampling transistor is connected between this input node and this signal wire,
This maintenance electric capacity is connected on this input node,
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, and, in the display device that shows,
Described image element circuit be provided with in order to compensation follow this driving transistors through the time drive current that the changes compensating circuit that descends,
Described compensating circuit detects the decline of this drive current from this output node side, and this result is fed back to this input node side.
5. display device as claimed in claim 4 is characterized in that:
Described compensating circuit detects the voltage drop that is produced at this electrooptic cell by this drive current from this output node side, relatively the level of the level of this input signal and this voltage drop that is detected and obtain difference will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.
6. display device as claimed in claim 4 is characterized in that:
Described compensating circuit is by constituting with the lower part, and they are: be connected detection electric capacity between this output node and the predetermined intermediate node, be inserted in switching transistor between this intermediate node and this signal wire, be inserted in the terminal node of an end that is connected in this maintenance electric capacity and the earthing potential be scheduled between switching transistor, be inserted in the switching transistor between this terminal node and this output node and be inserted in this terminal node and this intermediate node between switching transistor.
7. the driving method of an image element circuit, this pixel circuit configuration is on sweep trace and signal wire cross section, at least be provided with: electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected the input node, its source electrode is connected output node, its drain electrode is connected predetermined power supply potential, one end of this electrooptic cell is connected output node, the other end is connected predetermined potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected this input node, it is characterized in that:
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell,
Detect the decline of this drive current from this output node side, this result fed back to this input node side, compensation follow this driving transistors through the time drive current that changes descend.
8. the driving method of a display device, this display device is by the sweep trace of row shape, the signal wire of row shape, the image element circuit that is configured in separately on both cross sections constitutes, described image element circuit is provided with electrooptic cell at least, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected the input node, its source electrode is connected output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected output node, the other end is connected on the predetermined potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected this input node, it is characterized in that:
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, and, when showing,
Detect the decline of this drive current from this output node side, this result fed back to this input node side, compensation follow this driving transistors through the time drive current that changes descend.
9. image element circuit is characterized in that:
Be configured on the cross section of sweep trace and signal wire, be provided with electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity at least,
The grid of this driving transistors is connected the input node, and its source electrode is connected output node, and its drain electrode is connected on the predetermined power supply potential,
One end of this electrooptic cell is connected output node, and the other end is connected on the predetermined potential,
This sampling transistor is connected between this input node and this signal wire,
This maintenance electric capacity is connected on this input node,
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Supply with in the image element circuit of drive current to this electrooptic cell according to being maintained at the signal potential that keeps on the electric capacity at described driving transistors,
Be provided with compensation follow this driving transistors through the time drive current that the changes compensating circuit that descends,
Described compensating circuit detects the decline of this drive current from this output node side, and this result is fed back to this input node side,
Therefore, described compensating circuit is provided with: will be done accumulating of certain hour and exported corresponding to the detecting unit that detects current potential of accumulating the quantity of electric charge by the electric charge of this drive current carrying; Relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to the feedback unit on this signal potential that remains on this maintenance electric capacity corresponding to the current potential of this difference.
10. image element circuit as claimed in claim 9 is characterized in that:
Described compensating circuit is by constituting with the lower part, and they are:
Be inserted in the switching transistor between this output node and this electrooptic cell,
Be connected another switching transistor of this output node, be connected the detection electric capacity between this switching transistor and the predetermined earthing potential,
Feedback capacity between the intermediate node that is connected this output node and is scheduled to,
Be inserted in the switching transistor between this intermediate node and this signal wire,
Switching transistor between the earthing potential that is inserted in the terminal node of an end that is connected to this maintenance electric capacity and is scheduled to,
Be inserted in the switching transistor between this terminal node and this output node, and
Be inserted in the switching transistor between this terminal node and this intermediate node.
11. a display device is characterized in that:
The image element circuit that is configured in both cross sections constitutes by the signal wire of sweep trace, the row shape of row shape, separately,
Described image element circuit is provided with electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity at least,
The grid of this driving transistors is connected the input node, and its source electrode is connected output node, and its drain electrode is connected on the predetermined power supply potential,
One end of this electrooptic cell is connected output node, and the other end is connected on the predetermined potential,
This sampling transistor is connected between this input node and this signal wire,
This maintenance electric capacity is connected on this input node,
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, and, in the display device that shows,
Described image element circuit be provided with in order to compensation follow this driving transistors through the time drive current that the changes compensating circuit that descends,
Described compensating circuit detects the decline of this drive current from this output node side, and this result is fed back to this input node side,
Therefore be provided with: will do accumulating of certain hour by the electric charge of this drive current carrying, output is corresponding to the detecting unit that detects current potential of accumulating the quantity of electric charge; Relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to the feedback unit on this signal potential that remains on this maintenance electric capacity corresponding to the current potential of this difference.
12. display device as claimed in claim 11 is characterized in that:
Described compensating circuit is by constituting with the lower part, and they are:
Be inserted in the switching transistor between this output node and this electrooptic cell,
Be connected another switching transistor on this output node, be connected the detection electric capacity between this switching transistor and the predetermined earthing potential,
Feedback capacity between the intermediate node that is connected this output node and is scheduled to,
Be inserted in the switching transistor between this intermediate node and this signal wire,
Switching transistor between the earthing potential that is inserted in the terminal node of an end that is connected in this maintenance electric capacity and is scheduled to,
Be inserted in the switching transistor between this terminal node and this output node, and
Be inserted in the switching transistor between this terminal node and this intermediate node.
13. the driving method of an image element circuit, this pixel circuit configuration is on sweep trace and signal wire cross section, at least be provided with electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected the input node, its source electrode is connected output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected output node, the other end is connected on the predetermined potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is being connected in this input node, it is characterized in that:
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell,
Detect the decline of this drive current from this output node side, its result fed back to this input node side, in order to compensation follow this driving transistors through the time drive current that changes decline,
To do accumulating of certain hour by the electric charge of this drive current carrying, obtain corresponding to the current potential that detects of accumulating the quantity of electric charge,
Relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.
14. the driving method of a display device, this display device is by the sweep trace of row shape, the signal wire of row shape, the image element circuit that is configured in separately on both cross sections constitutes, described image element circuit is provided with electrooptic cell at least, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected the input node, its source electrode is connected output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected output node, the other end is connected on the predetermined potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is being connected in this input node, it is characterized in that:
The time action in being scanned line selection of this sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, and, when showing,
Detect the decline of drive current from this output node side, this result fed back to this input node side, compensation follow this driving transistors through the time variation the decline of drive current,
To accumulate as certain hour and obtain by the electric charge of this drive current carrying corresponding to the current potential that detects of accumulating the quantity of electric charge,
Relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.
15. an image element circuit is characterized in that:
Be configured on sweep trace and the signal cross part, be provided with electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity at least,
The grid of this driving transistors is connected the input node, and its source electrode is connected on the output node, and its drain electrode is connected on the predetermined power supply potential,
One end of this electrooptic cell is connected output node, and the other end is connected on the predetermined potential,
This sampling transistor is connected between this input node and this signal wire,
This maintenance electric capacity is connected on this input node,
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Supply with in the image element circuit of drive current to this electrooptic cell according to the signal potential that remains on this maintenance electric capacity at described driving transistors,
Be provided with in order to compensation follow this driving transistors through the time drive current that changes the compensating circuit of decline,
Described compensating circuit detects the decline of this drive current from this output node side, and this result is fed back to this input node side,
Therefore this compensating circuit is provided with: have the resistance components that will be inserted between this input node and the earthing potential of being scheduled to and the voltage drop that produces at this resistance composition according to the drive current that flows to earthing potential from this output node as the detecting unit of the capacitive component that detects the current potential maintenance; Relatively this incoming signal level and this detect potential level and obtain difference, will be added to the feedback unit on this signal potential that remains on this maintenance electric capacity corresponding to the current potential of this difference.
16. image element circuit as claimed in claim 15 is characterized in that,
Described compensating circuit is by constituting with the lower part, and they are:
Be inserted in the switching transistor between this output node and this electrooptic cell,
Be connected another switching transistor on this output node, the detection transistor that diode is connected between this switching transistor and predetermined earthing potential, the detection electric capacity that is connected in parallel with this detection transistor,
Feedback capacity between the intermediate node that is connected this output node and is scheduled to,
Be inserted in the switching transistor between this intermediate node and this signal wire,
Switching transistor between the earthing potential that is inserted in the terminal node of an end that is connected in this maintenance electric capacity and is scheduled to,
Be inserted in the switching transistor between this terminal node and this output node, and
Be inserted in the switching transistor between this terminal node and this intermediate node.
17. a display device is characterized in that:
Constitute by the signal wire of sweep trace, the row shape of row shape, the image element circuit that is configured in both cross sections separately,
Described image element circuit is provided with electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity at least,
The grid of this driving transistors is connected the input node, and its source electrode is connected output node, and its drain electrode is connected on the predetermined power supply potential,
One end of this electrooptic cell is connected output node, and the other end is connected on the predetermined potential,
This sampling transistor is connected between this input node and this signal wire,
This maintenance electric capacity is connected on this input node,
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, and, in the display device that shows,
Described image element circuit be provided with compensation follow this driving transistors through the time drive current that the changes compensating circuit that descends,
Described compensating circuit detects this drive current from this output node side, and this is really fed back to this input node side,
Therefore be provided with: have according to being inserted in the resistance components between this output node and the predetermined earthing potential and flowing into this drive current of earthing potential from this output node, the voltage drop that will produce on this resistance components is as the detecting unit of the capacitive component that detects the current potential maintenance; Relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to the feedback unit on this signal potential that remains on this maintenance electric capacity corresponding to the current potential of this difference.
18. display device as claimed in claim 17 is characterized in that:
Described compensating circuit is by constituting with the lower part, and they are:
Be inserted in the switching transistor between this output node and this electrooptic cell,
Be connected another switching transistor on this output node, the detection transistor that diode is connected between this switching transistor and predetermined earthing potential, the detection electric capacity that is connected in parallel with this detection transistor,
Feedback capacity between the intermediate node that is connected this output node and is scheduled to,
Be inserted in the switching transistor between this intermediate node and this signal wire,
Switching transistor between the earthing potential that is inserted in the terminal node of an end that is connected in this maintenance electric capacity and is scheduled to,
Be connected the switching transistor between this terminal node and this output node, and
Be inserted in the switching transistor between this terminal node and this intermediate node.
19. the driving method of an image element circuit, this pixel circuit configuration is on the cross section of sweep trace and signal wire, at least be provided with electrooptic cell, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected the input node, its source electrode is connected output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected output node, the other end is connected on the predetermined potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is being connected in this input node, it is characterized in that:
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell,
Detect the decline of this drive current from this output node side, this result fed back to this input node side, compensation follow this driving transistors through the time drive current that changes decline,
According to the drive current that on the resistance components between the earthing potential that is inserted in this output node and is scheduled to, flows through, obtain the voltage drop and the conduct that on resistance components, produce and detect current potential,
Relatively the level of this input signal and this detect the level of current potential and obtain difference, will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.
20. the driving method of a display device, this display device is by the sweep trace of row shape, the signal wire of row shape, the image element circuit that is configured in separately on both cross sections constitutes, described image element circuit is provided with electrooptic cell at least, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected the input node, its source electrode is connected output node, its drain electrode is connected on the predetermined power supply potential, one end of this electrooptic cell is connected output node, the other end is connected on the predetermined potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected in this input node, it is characterized in that:
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this electrooptic cell, and, when showing,
Detect the decline of this drive current from this output node side, its result fed back to this input node side, compensation follow this driving transistors through the time drive current that changes decline,
Obtain the voltage drop and the conduct that on this resistance components, produce according to this drive current that on the resistance components between the earthing potential that is inserted in this output node and is scheduled to, flows through and detect current potential,
Relatively the level of this input signal and this detect the level of current potential and obtain difference, and will be added to corresponding to the current potential of this difference on this signal potential that remains on this maintenance electric capacity.
21. an image element circuit is characterized in that:
Be configured on the cross section of sweep trace and signal wire, be provided with light-emitting component, driving transistors, sampling transistor and maintenance electric capacity at least,
The grid of this driving transistors is connected the input node, and its source electrode is connected output node, and its drain electrode is connected on the predetermined power supply potential,
One end of this light-emitting component is connected output node, and the other end is connected on the predetermined potential,
This sampling transistor is connected between this input node and this signal wire,
This maintenance electric capacity is connected on this input node,
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this light-emitting component,
Follow in the image element circuit luminous at described light-emitting component by the voltage drop of this drive current generation,
Set up compensation by this light-emitting component through the time change the compensating circuit that the brightness cause descends,
Described compensating circuit from this output node side detect since this light-emitting component through the time change this voltage drop that increases, will feed back to this input node side corresponding to the signal potential of the level of this voltage drop that is detected,
Described driving transistors is supplied with the drive current that the brightness that is enough to compensate this light-emitting component descends according to this signal potential that is fed.
22. image element circuit as claimed in claim 21 is characterized in that:
Described compensating circuit comprises 2 detection electric capacity that are connected in series between this output node and this input node,
Described be connected in series 2 are detected electric capacity and detect the voltage drop that produces at this light-emitting component and keep by the ratio of division of each electric capacity from this output node side, and the level of that part of voltage decline that will keep at the detection electric capacity that is arranged in this input node side feeds back as this signal potential simultaneously.
23. image element circuit as claimed in claim 22 is characterized in that:
Described compensating circuit is by constituting with the lower part, and they are:
Detect a switching transistor that detection electric capacity inserts in parallel that is positioned at this output node side in the electric capacity with these 2 of being connected in series,
Be inserted at another of this input node side and detect switching transistor between electric capacity and the earthing potential of being scheduled to,
Be inserted at another detection electric capacity of this same input node side and the switching transistor between this input node,
Switching transistor between the earthing potential that is inserted in this maintenance electric capacity and is scheduled to, and
Be inserted in this same maintenance electric capacity and the switching transistor between this output node.
24. an image display device is characterized in that:
Constitute by the sweep trace of row shape, the signal wire of row shape, the image element circuit that is configured on both cross sections separately,
Described image element circuit is provided with light-emitting component, driving transistors, sampling transistor and maintenance electric capacity at least,
The grid of this driving transistors is connected the input node, and its source electrode is connected output node, and its drain electrode is connected on the predetermined power supply potential,
One end of this light-emitting component is connected output node, and the other end is connected on the predetermined potential,
This sampling transistor is connected between this input node and this signal wire,
This maintenance electric capacity is connected on this input node,
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this light-emitting component,
Follow in the image display device luminous at described light-emitting component by the voltage drop of this drive current generation,
Set up in the described image element circuit compensation by this light-emitting component through the time change the compensating circuit that the brightness that causes descends,
Described compensating circuit from this output node side detect since this light-emitting component through the time variation this voltage drop of increasing, will feed back to this input node side corresponding to the signal potential of the level of this voltage drop that is detected,
Described driving transistors is supplied with the drive current that the brightness that is enough to compensate this light-emitting component descends according to this signal potential that is fed.
25. image display device as claimed in claim 24 is characterized in that:
Described compensating circuit comprises 2 detection electric capacity that are connected in series between this output node and this input node,
Described be connected in series 2 are detected electric capacity and detect the voltage drop that produces at this light-emitting component and keep by the ratio of division of each electric capacity from this output node side, and the level of that part of voltage decline that will keep at the detection electric capacity that is arranged in this input node side feeds back as this signal potential simultaneously.
26. image display device as claimed in claim 25 is characterized in that:
Described compensating circuit is by constituting with the lower part, and they are:
Detect a switching transistor that detection electric capacity inserts in parallel that is positioned at this output node side in the electric capacity with these 2 of being connected in series,
Be inserted at another of this input node side and detect switching transistor between electric capacity and the earthing potential of being scheduled to,
Be inserted at another detection electric capacity of this same input node side and the switching transistor between this input node,
Switching transistor between the earthing potential that is inserted in this maintenance electric capacity and is scheduled to, and
Be inserted in this same maintenance electric capacity and the switching transistor between this output node.
27. the driving method of an image element circuit, this pixel circuit configuration is on sweep trace and signal wire cross section, at least be provided with light-emitting component, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected the input node, its source electrode is connected output node, its drain electrode is connected on the predetermined power supply potential, one end of this light-emitting component is connected output node, the other end is connected on the predetermined potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected in this input node, it is characterized in that:
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this light-emitting component,
Described light-emitting component follows the voltage drop that is produced by this drive current luminous, in addition
For compensate by this light-emitting component through the time change the brightness cause and descend, from this output node side detect with this light-emitting component through the time change this voltage drop that increases, will feed back to this input node side corresponding to the signal potential of the level of this detected voltage drop,
Described driving transistors is according to this signal potential that is fed, the drive current that the brightness that supplying with is enough to compensate this light-emitting component descends.
28. the driving method of an image display device, this image display device is by the sweep trace of row shape, the signal wire of row shape, the image element circuit that is configured in the part of both intersections separately constitutes, described image element circuit is provided with light-emitting component at least, driving transistors, sampling transistor and maintenance electric capacity, the grid of this driving transistors is connected the input node, its source electrode is connected output node, its drain electrode is connected on the predetermined power supply potential, one end of this light-emitting component is connected output node, the other end is connected on the predetermined potential, this sampling transistor is connected between this input node and this signal wire, this maintenance electric capacity is connected in this input node, it is characterized in that:
The time action in being scanned line selection of described sampling transistor, from this signal wire to the input signal sampling and remain on this maintenance electric capacity,
Described driving transistors is supplied with drive current according to the signal potential that remains on this maintenance electric capacity to this light-emitting component,
Described light-emitting component follows the voltage drop that is produced by this drive current luminous, and, when showing,
For compensation by this light-emitting component through the time change the brightness cause and descend, from this output node side detect with this light-emitting component through the time change this voltage drop that increases, and will feed back to this input node side corresponding to the signal potential of the level of this voltage drop that is detected
Described driving transistors is according to this signal potential that is fed, the drive current that the brightness that supplying with is enough to compensate this light-emitting component descends.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004198056A JP4831392B2 (en) | 2004-07-05 | 2004-07-05 | Pixel circuit and display device |
| JP198057/04 | 2004-07-05 | ||
| JP198056/04 | 2004-07-05 | ||
| JP201223/04 | 2004-07-08 | ||
| JP215056/04 | 2004-07-23 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1722207A true CN1722207A (en) | 2006-01-18 |
| CN100487777C CN100487777C (en) | 2009-05-13 |
Family
ID=35792488
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200510081957.4A Expired - Fee Related CN100487777C (en) | 2004-07-05 | 2005-07-05 | Pixel circuit, display device and driving method |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP4831392B2 (en) |
| CN (1) | CN100487777C (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN102654979A (en) * | 2011-03-04 | 2012-09-05 | 索尼公司 | Pixel circuit, display panel, display device and electronic unit |
| CN101625831B (en) * | 2008-07-10 | 2012-11-14 | 索尼株式会社 | Image display device |
| CN101933074B (en) * | 2007-12-21 | 2013-04-17 | 全球Oled科技有限责任公司 | Electroluminescent display having compensated analog signal for activating the driving transistor |
| CN105448238A (en) * | 2014-09-19 | 2016-03-30 | 乐金显示有限公司 | Organic light emitting display device |
| CN107610648A (en) * | 2017-09-28 | 2018-01-19 | 深圳市华星光电半导体显示技术有限公司 | A kind of method of compensation AMOLED pixel differences |
| CN108257549A (en) * | 2016-12-29 | 2018-07-06 | 乐金显示有限公司 | Electroluminescent display |
| CN108538241A (en) * | 2018-06-29 | 2018-09-14 | 京东方科技集团股份有限公司 | Pixel circuit and its driving method, display device |
| WO2020042522A1 (en) * | 2018-08-30 | 2020-03-05 | Boe Technology Group Co., Ltd. | Display panel and driving method thereof |
| CN111341270A (en) * | 2018-12-18 | 2020-06-26 | 奇景光电股份有限公司 | Method for compensating brightness unevenness of display panel and display device |
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| JP4984520B2 (en) * | 2005-12-20 | 2012-07-25 | セイコーエプソン株式会社 | Electronic circuit, electronic device and electronic equipment |
| JP5103737B2 (en) * | 2006-01-11 | 2012-12-19 | セイコーエプソン株式会社 | Electronic circuit, electronic device and electronic equipment |
| JP5332109B2 (en) * | 2007-02-06 | 2013-11-06 | セイコーエプソン株式会社 | Electro-optical device and electronic apparatus |
| CN101903933B (en) | 2008-01-07 | 2013-03-27 | 松下电器产业株式会社 | Display device, electronic device, and driving method |
| JP5494684B2 (en) * | 2012-01-20 | 2014-05-21 | セイコーエプソン株式会社 | Driving method of electronic circuit |
| JP6228753B2 (en) * | 2012-06-01 | 2017-11-08 | 株式会社半導体エネルギー研究所 | Semiconductor device, display device, display module, and electronic device |
| WO2023194960A1 (en) * | 2022-04-06 | 2023-10-12 | Gentex Corporation | Electro-optic device having controlled electro-optic segments |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0923067B1 (en) * | 1997-03-12 | 2004-08-04 | Seiko Epson Corporation | Pixel circuit, display device and electronic equipment having current-driven light-emitting device |
-
2004
- 2004-07-05 JP JP2004198056A patent/JP4831392B2/en not_active Expired - Fee Related
-
2005
- 2005-07-05 CN CN200510081957.4A patent/CN100487777C/en not_active Expired - Fee Related
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101933074B (en) * | 2007-12-21 | 2013-04-17 | 全球Oled科技有限责任公司 | Electroluminescent display having compensated analog signal for activating the driving transistor |
| CN101625831B (en) * | 2008-07-10 | 2012-11-14 | 索尼株式会社 | Image display device |
| CN102654979A (en) * | 2011-03-04 | 2012-09-05 | 索尼公司 | Pixel circuit, display panel, display device and electronic unit |
| CN105448238A (en) * | 2014-09-19 | 2016-03-30 | 乐金显示有限公司 | Organic light emitting display device |
| CN108257549A (en) * | 2016-12-29 | 2018-07-06 | 乐金显示有限公司 | Electroluminescent display |
| CN107610648A (en) * | 2017-09-28 | 2018-01-19 | 深圳市华星光电半导体显示技术有限公司 | A kind of method of compensation AMOLED pixel differences |
| CN108538241A (en) * | 2018-06-29 | 2018-09-14 | 京东方科技集团股份有限公司 | Pixel circuit and its driving method, display device |
| US11270630B2 (en) | 2018-06-29 | 2022-03-08 | Boe Technology Group Co., Ltd. | Driving circuit, driving method thereof and display apparatus |
| WO2020042522A1 (en) * | 2018-08-30 | 2020-03-05 | Boe Technology Group Co., Ltd. | Display panel and driving method thereof |
| US11257433B2 (en) | 2018-08-30 | 2022-02-22 | Boe Technology Group Co., Ltd. | Display panel and driving method thereof |
| CN111341270A (en) * | 2018-12-18 | 2020-06-26 | 奇景光电股份有限公司 | Method for compensating brightness unevenness of display panel and display device |
| CN111341270B (en) * | 2018-12-18 | 2021-07-23 | 奇景光电股份有限公司 | Method for compensating brightness unevenness of display panel and display device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2006018167A (en) | 2006-01-19 |
| CN100487777C (en) | 2009-05-13 |
| JP4831392B2 (en) | 2011-12-07 |
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