CN107424568B

CN107424568B - Display device comprising light emitting diode pixels and compensation device and method

Info

Publication number: CN107424568B
Application number: CN201710903562.0A
Authority: CN
Inventors: 吴素华; 侯珊珊; 黎守新
Original assignee: Chengdu Goldensi Technology Co ltd
Current assignee: Chengdu Goldensi Technology Co ltd
Priority date: 2017-09-29
Filing date: 2017-09-29
Publication date: 2020-04-07
Anticipated expiration: 2037-09-29
Also published as: CN107424568A

Abstract

The invention discloses a display device comprising light emitting diode pixels, a compensation device and a method, wherein the light emitting diode pixels comprise light emitting diodes, driving transistors, a first switch unit and a second switch unit; the display device comprises a current extraction unit for extracting the current of the drive transistor in a first stage and obtaining the current value of the extracted current; the voltage acquisition unit is used for acquiring a voltage value of the grid electrode of the driving transistor corresponding to the acquired current value; the calculation output unit is used for calculating and obtaining the solution of unknown numbers in the equation set based on the obtained current value, the voltage value and the equation set which is formed by the current formula in the saturation area, calculating and obtaining a data voltage value based on the solution of the equation set, the current value required by the preset display gray scale of the light-emitting diode and the current formula in the saturation area, and outputting the data voltage which corresponds to the data voltage value and is used for controlling the light-emitting diode to drive the light-emitting diode to emit light according to the preset display gray scale to the grid electrode of the driving transistor in the second stage. Which makes the light emitting current of the driving transistors uniform.

Description

Display device comprising light emitting diode pixels and compensation device and method

Technical Field

The invention relates to the technical field of light emitting diode pixel display, in particular to a display device comprising light emitting diode pixels, a compensation device and a compensation method.

Background

Light emitting diode (organic, inorganic) display panels have attracted considerable attention because of their low power consumption, full viewing angle, high color gamut, high contrast, and suitability for flexible displays. A conventional active matrix light emitting diode (OLED or LED) pixel drive circuit is shown in figure 1. In a semiconductor manufacturing process, process parameters of each transistor may have a deviation, so that driving currents formed by the driving transistors under the same display data voltage are inconsistent, and the display effect of the panel is reduced accordingly. In the prior invention, a plurality of pixel circuit structures for compensating threshold voltage fluctuation exist, but the influence of mobility, unit capacitance and other process parameters on the current of the driving transistor cannot be compensated. As shown in fig. 1.

Disclosure of Invention

The invention provides a display device comprising light emitting diode pixels, a compensation device and a method, which can make the light emitting current of a driving transistor consistent.

In order to solve the technical problems, the invention adopts the following technical scheme:

a display device comprising a light emitting diode pixel, the light emitting diode pixel comprising a light emitting diode, a driving transistor for driving the light emitting diode to emit light in a third stage, and first and second switching units connected in series with each other for controlling the driving transistor to be in a diode connection state in a first stage; the display device includes:

a current extraction unit for extracting a current of the driving transistor at a first stage and obtaining a current value of the extracted current;

a voltage acquisition unit for acquiring a voltage value of the gate of the drive transistor corresponding to the acquired current value when the current of the drive transistor is extracted;

the calculation output unit is used for calculating and obtaining the solution of unknown numbers in the equation set based on the obtained current value, the obtained voltage value and the equation set which is formed by the current formula in the saturation area, calculating and obtaining a data voltage value based on the solution of the equation set, the current value required by the preset display gray scale of the light-emitting diode and the current formula in the saturation area, and controlling the driving transistor to drive the light-emitting diode to emit light according to the preset display gray scale in a third stage corresponding to the data voltage value and outputting the data voltage to the grid electrode of the driving transistor in a second stage;

the unknown number comprises field effect mobility of the driving transistor, capacitance of the insulating layer, channel width-length ratio, threshold voltage and affected working voltage.

The cathode of the light emitting diode is electrically connected with the common ground; the source electrode of the driving transistor is electrically connected with the working voltage anode, and the drain electrode of the driving transistor is electrically connected with the anode of the light-emitting diode; the third end of the first switch unit is electrically connected with the grid electrode of the driving transistor; the first end of the second switch unit is electrically connected with the first end of the first switch unit, and the third end of the second switch unit is electrically connected with the drain electrode of the driving transistor; the second end of the first switch unit is used for inputting a first control signal to control the first switch unit to be closed or opened and the second end of the second switch unit is used for inputting a second control signal to control the second switch unit to be closed or opened, the second end of the first switch unit is used for inputting a fourth control signal to control the first switch unit to be closed or opened and the second end of the second switch unit is used for inputting a fourth control signal to control the second switch unit to be closed or opened, or the second end of the first switch unit is used for inputting an Nth row scanning signal to control the first switch unit to be closed or opened and the second end of the second switch unit is used for inputting an N-1 th row scanning signal to control the second switch unit to be closed or opened; the output end of the calculation output unit is electrically connected with the first end of the first switch unit.

When the influence of any unknown number of the field effect mobility, the capacitance of the insulating layer, the channel width-length ratio, the threshold voltage and the influenced working voltage on the display gray scale of the light-emitting diode is less than or equal to 5%, the number of the unknown numbers is reduced by one, and the reduced unknown numbers are the unknown numbers which have the influence of the field effect mobility, the capacitance of the insulating layer, the channel width-length ratio, the threshold voltage and the influenced working voltage on the display gray scale of the light-emitting diode less than or equal to 5%.

The light emitting diode pixel further comprises a third switching unit connected in series between the drain of the driving transistor and the anode of the light emitting diode, and the third switching unit is controlled to be turned off or turned on by a third control signal.

The light emitting diode pixel also comprises a fourth switching unit which is connected between the source electrode of the driving transistor and the working voltage anode in series, and the fourth switching unit is controlled to be switched off or switched on by a third control signal.

The light emitting diode pixel further comprises a fifth switch unit, wherein a first end of the fifth switch unit is electrically connected with the drain electrode of the driving transistor, a second end of the fifth switch unit is used for inputting a second control signal, a fourth control signal or an N-1 th row scanning signal so as to control the second switch unit to be turned on or off, and a third end of the fifth switch unit is electrically connected with the input end of the current extraction unit or the third end of the fifth switch unit is electrically connected with the input ends of the current extraction unit and the voltage acquisition unit.

A display device comprising a light emitting diode pixel, the light emitting diode pixel comprising a light emitting diode, a driving transistor for driving the light emitting diode to emit light in a third stage, and a second switching unit for controlling the driving transistor to be in a diode connection state in a first stage; the display device includes:

The cathode of the light emitting diode is electrically connected with the common ground; the source electrode of the driving transistor is electrically connected with the working voltage anode, and the drain electrode of the driving transistor is electrically connected with the anode of the light-emitting diode; the first end of the second switch unit is electrically connected with the grid electrode of the driving transistor, and the third end of the second switch unit is electrically connected with the drain electrode of the driving transistor; the second end of the second switch unit is used for inputting a second control signal to control the second switch unit to be turned off or on, the second end of the second switch unit is used for inputting a fourth control signal to control the second switch unit to be turned off or on, or the second end of the second switch unit is used for inputting an N-1 th row scanning signal to control the second switch unit to be turned off or on.

A light emitting diode pixel driving compensation device comprises a light emitting diode, a driving transistor for driving the light emitting diode to emit light in a third stage, and a first switch unit and a second switch unit which are connected in series and control the driving transistor to be in a diode connection state in a first stage; or the light emitting diode pixel comprises a light emitting diode, a driving transistor for driving the light emitting diode to emit light in a third stage, and a second switching unit for controlling the driving transistor to be in a diode connection state in a first stage; the device includes:

in the first stage, the driving transistor is in a diode connection state, and the unknown number comprises field effect mobility of the driving transistor, capacitance of an insulating layer, channel width-length ratio, threshold voltage and affected working voltage.

A display device comprising light emitting diode pixels comprises the light emitting diode pixel driving compensation device.

A light emitting diode pixel driving compensation method, the light emitting diode being driven by a driving transistor to emit light in a third stage, the method comprising the steps of:

controlling the driving transistor to be in a diode connection state in a first stage;

extracting the current of the driving transistor in a first stage and obtaining the current value of the extracted current;

acquiring a voltage value of the gate of the driving transistor corresponding to the acquired current value when the current of the driving transistor is extracted;

calculating to obtain a solution of an unknown number in an equation set based on the obtained current value, the obtained voltage value and the equation set formed by the current formula in the saturation area, calculating to obtain a data voltage value based on the solution of the equation set, the current value required by the preset display gray scale of the light-emitting diode and the current formula in the saturation area, and outputting the data voltage which corresponds to the data voltage value and is used for controlling the driving transistor to drive the light-emitting diode to emit light according to the preset display gray scale to the grid electrode of the driving transistor in the second stage;

The present invention has the following advantageous technical effects.

The method comprises the steps of driving a driving transistor of a light-emitting diode to be in a diode connection state in the first stage, extracting the current of the driving transistor and obtaining the current value of the extracted current in the first stage, obtaining the voltage value of a grid electrode of the driving transistor corresponding to the obtained current value at the same time, calculating to obtain the solution of an unknown number in an equation set based on the obtained current value, the obtained voltage value and the equation set formed by a current formula in a saturation region, and calculating to obtain a data voltage value based on the solution of the equation set, the current value required by the preset display gray scale of the light-emitting diode and the current formula in the saturation region, wherein the unknown number comprises the field effect mobility of the driving transistor, the capacitance of an insulating layer, the channel width-length ratio, the threshold voltage and the influenced working voltage. In the second stage, the data voltage corresponding to the data voltage value is output to the grid electrode of the driving transistor, and the driving transistor is controlled to drive the light emitting diode to emit light according to the preset display gray scale, so that the errors of parameters such as field effect mobility, capacitance of an insulating layer, channel width-length ratio, threshold voltage, influenced working voltage and the like are all converted into the data voltage, the light emitting currents of all the driving transistors are consistent, namely the light emitting currents of the light emitting diodes are completely unrelated to the process fluctuation of the driving transistors, and the display effect is improved. Meanwhile, the light emitting diode pixel driving compensation device and the method are simple and are particularly suitable for a display device with high PPI.

Drawings

Fig. 1 is a conventional 2T1C pixel circuit.

Fig. 2 is a schematic circuit diagram of a display device including led pixels according to the present invention.

Fig. 3 is a timing diagram of signals in the circuit configuration shown in fig. 2.

Fig. 4 is a schematic circuit diagram of another display device including led pixels according to the present invention.

Fig. 5 is a timing diagram of signals in the circuit configuration shown in fig. 4.

Fig. 6 is a schematic circuit diagram of a third display device including led pixels according to the present invention.

Fig. 7 is a timing diagram of signals in the circuit configuration shown in fig. 6.

Fig. 8 is a schematic circuit diagram of a fourth display device including led pixels according to the present invention.

Fig. 9 is a timing diagram of signals in the circuit configuration shown in fig. 8.

Fig. 10 is a schematic circuit diagram of a fifth display device including led pixels according to the present invention.

Fig. 11 is a timing diagram of signals in the circuit configuration shown in fig. 10.

Fig. 12 is a schematic circuit diagram of a sixth display device including led pixels according to the present invention.

Fig. 13 is a timing diagram of signals in the circuit configuration shown in fig. 12.

Fig. 14 is a schematic circuit diagram of a seventh display device including led pixels according to the present invention.

Fig. 15 is a timing diagram of signals in the circuit configuration shown in fig. 14.

Fig. 16 is a schematic circuit diagram of an eighth display device including led pixels according to the present invention.

Fig. 17 is a timing chart of signals in the circuit configuration shown in fig. 16.

Fig. 18 is a schematic circuit diagram of a ninth display device including led pixels according to the present invention.

Fig. 19 is a timing chart of signals in the circuit configuration shown in fig. 18.

Fig. 20 is a schematic circuit diagram of a tenth display device including led pixels according to the present invention.

Fig. 21 is a timing diagram of signals in the circuit configuration shown in fig. 20.

Fig. 22 is a schematic circuit diagram of an eleventh display device including led pixels according to the present invention.

Fig. 23 is a timing chart of signals in the circuit configuration shown in fig. 22.

Fig. 24 is a schematic circuit diagram of a twelfth display device including led pixels according to the present invention.

Fig. 25 is a timing chart of signals in the circuit configuration shown in fig. 24.

Fig. 26 is a schematic circuit diagram of a thirteenth display device including led pixels according to the present invention.

Fig. 27 is a timing chart of signals in the circuit configuration shown in fig. 26.

Fig. 28 is a schematic circuit diagram of a fourteenth display device including led pixels according to the invention.

Fig. 29 is a timing chart of signals in the circuit configuration shown in fig. 28.

Fig. 30 is a schematic circuit structure diagram of a fifteenth display device including led pixels according to the present invention.

Fig. 31 is a timing chart of signals in the circuit configuration shown in fig. 30.

Fig. 32 is a schematic circuit diagram of a sixteenth display device including led pixels according to the present invention.

Fig. 33 is a timing chart of signals in the circuit configuration shown in fig. 32.

Fig. 34 is a schematic circuit diagram of a seventeenth display device including led pixels according to the present invention.

Fig. 35 is a timing chart of signals in the circuit configuration shown in fig. 34.

Fig. 36 is a schematic circuit diagram of an eighteenth display device including led pixels according to the present invention.

Fig. 37 is a timing chart of signals in the circuit configuration shown in fig. 36.

Fig. 38 is a schematic circuit diagram of a nineteenth display device including led pixels according to the present invention.

Fig. 39 is a timing chart of signals in the circuit configuration shown in fig. 38.

Fig. 40 is a schematic circuit diagram of a twentieth display device including led pixels according to the present invention.

Fig. 41 is a timing chart of signals in the circuit configuration shown in fig. 40.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The embodiments and features of the embodiments of the present invention may be arbitrarily combined with each other without conflict. Also, while a logical order is shown in the flow diagrams, in some cases, the steps shown or described may be performed in an order different than here.

Fig. 2 schematically shows a circuit structure of a display device including led pixels according to various embodiments of the present invention, wherein G, D, S in fig. 2 is a node symbol, and G, D, S in other figures has the same meaning. Fig. 3 is a timing chart of signals in the circuit structure shown in fig. 2, in which Iref represents the current drawn, Vg represents the gate voltage of the driving transistor M3, and Iref and Vg in other figures have the same meaning.

In the display device including the led pixel shown in fig. 2, the led pixel includes a led L, a driving transistor M3 for driving the led L to emit light in a third stage T3, and a first and a

second switch units

11, 12 connected in series with each other for controlling the driving transistor M3 to be in a diode-connected state in a first stage T1. The display device includes a current drawing unit 13, a voltage obtaining unit 14, a calculation output unit 15, and a third switching unit 16.

The third terminal 11c of the first switch unit 11 is electrically connected to the gate of the driving transistor M3, and the second terminal 11b thereof is used for inputting the first control signal Wr to control the first switch unit 11 to turn off or on.

The first terminal 12a of the second switch unit 12 is electrically connected to the first terminal 11a of the first switch unit 11, the second terminal 12b thereof is used for inputting the second control signal SI to control the second switch unit 12 to turn off or on, and the third terminal 12c of the second switch unit 12 is electrically connected to the drain of the driving transistor M3.

The third switching unit 16 is connected in series between the drain of the driving transistor M3 and the anode of the light emitting diode L, and the third switching unit 16 is controlled to be turned off or on by the third control signal Em.

The capacitor C is connected across the gate and source of the driving transistor M3. The source of the driving transistor M3 is electrically connected to the positive electrode of the operating voltage Vdd, and the cathode of the light emitting diode L is electrically connected to the common ground Vss.

In the embodiment shown in fig. 2, the first, second, and

third switching units

11, 12, and 16 are all PMOS transistors, which are respectively a PMOS transistor M1, a PMOS transistor M2, and a PMOS transistor M4. The driving transistor M3 is a PMOS transistor. It is understood that the first, second and

third switching units

11, 12 and 16 and the driving transistor M3 may be, but not limited to, PMOS transistors, NMOS transistors, etc. The following related switch units are analogized.

In the embodiment shown in fig. 2, the input terminal of the current drawing unit 13, the input terminal of the voltage obtaining unit 14, and the output terminal of the calculation output unit 15 are electrically connected to the first terminal 11a of the first switch unit 11. As for the electrical connections among the current drawing unit 13, the voltage obtaining unit 14, and the calculation output unit 15, which are not shown in the drawings for the sake of simplicity, those skilled in the art will understand the connection relationship among them according to the following description.

Referring to fig. 3, in the first stage T1, the first control signal Wr and the second control signal SI are both low, the first switch unit 11 and the second switch unit 12 are both turned on, and the gate and the drain of the driving transistor M3 are connected, so that the driving transistor M3 is in a diode connection state. The third control signal Em is low and the third switching unit 16 is turned on.

Referring to fig. 3 together, the current drawing unit 13 is configured to draw the current of the driving transistor M3 and obtain the current value of the drawn current at the first stage T1. For example, the field effect mobility of the driving transistor M3, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the operating voltage such as the operating voltage fluctuation all have an influence on the display gray scale of the led greater than 5% (with the advancement of the technology, the value may be less than 5%, such as 3%, 1%. multidot.., etc.), and at this time, as in the timing chart presented in fig. 3, the current extracting unit 13 extracts the current of the driving transistor M3 five times in the first stage T1 and obtains the current values of the extracted current as I1, I2, I3, I4, and I5, respectively.

The voltage acquisition unit 14 is configured to acquire a voltage value of the gate of the driving transistor M3 corresponding to the acquired current value when drawing the current of the driving transistor M3. For example, the field effect mobility of the driving transistor M3, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the operating voltage such as the operating voltage fluctuation all have an influence on the display gray scale of the led of more than 5%, and at this time, as in the timing diagram presented in fig. 3, the current extracting unit 13 extracts the current of the driving transistor M3 five times in the first stage T1, the voltage obtaining unit 14 obtains the voltage values V1, V2, V3, V4, V5 corresponding to the obtained current value of the gate of the driving transistor M3 5 times when extracting the current of the driving transistor M3, I1 corresponds to V1, I2 corresponds to V2, I3 corresponds to V3, I4 corresponds to V4, I5 corresponds to V5, that is, the current extraction unit 13 obtains the current value of the extracted current as I1, at this time, the voltage value obtained by the voltage obtaining unit 14 is V1, I1 corresponds to V1, and the rest of the current values correspond to the voltage values, and so on.

The calculation output unit 15 is configured to calculate a solution of an unknown number in the equation set based on the obtained current value, the obtained voltage value and the equation set associated by the saturation region current formula, calculate a data voltage value Vdt based on the solution of the equation set, the current value required by the led to emit light at a predetermined display gray scale and the saturation region current formula, and output a data voltage corresponding to the data voltage value Vdt and controlling the driving transistor to drive the led M3 in the third stage T3 to drive the led L to emit light at the predetermined display gray scale to the gate of the driving transistor M3 in the second stage T2.

The unknowns include the field effect mobility of the driving transistor M3, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the affected operating voltage. The affected operating voltage refers to the actual operating voltage when the operating voltage is unstable due to some factors, such as voltage fluctuation.

The calculation output unit 15 calculates the solution of the unknowns in the equation set based on the above-obtained I1, I2, I3, I4, I5, V1, V2, V3, V4, V5, and the equation set (composed of equations (1) to (5) below) associated with the saturation region current formula, where μ, Cox, W/L, Vth, Vdd' are 5 unknowns of the equation set.

I1=1/2*μ*Cox*W/L*（Vdd′-V1-|Vth|）²（1）

I2=1/2*μ*Cox*W/L*（Vdd ′-V2-|Vth|）²（2）

I3=1/2*μ*Cox*W/L*（Vdd ′-V3-|Vth|）²（3）

I4=1/2*μ*Cox*W/L*（Vdd ′-V4-|Vth|）²（4）

I5=1/2*μ*Cox*W/L*（Vdd ′-V5-|Vth|）²（5）

In equations (1) to (5), μ represents field effect mobility, Cox represents capacitance of the insulating layer, W/L represents channel width-to-length ratio, Vth represents threshold voltage, and Vdd' represents operating voltage after influence.

The calculation output unit 15 solves the equation set, so that the solutions of the 5 unknowns are calculated and recorded as μ 1, Cox1, W/L1, Vth1 and Vdd' 1 respectively.

The calculation output unit 15 calculates a data voltage value Vdt1 for controlling the driving transistor M3 to drive the light emitting diode L to emit light according to the predetermined display gray scale in the second stage T2 based on the solution μ 1, Cox1, W/L1, Vth1, Vdd' 1, the current value Ioled required by the predetermined display gray scale of the light emitting diode L, and the saturation region current formula of the equation set, as shown in formula (6).

Vdt1=[2*Ioled/(u1 *cox1 *w/l1)]^1/2+ Vdd ′1-|Vth1| （6）

In the formula (6), μ 1, Cox1, W/L1, Vth1, Ioled, and Vdd' 1 are known values.

Referring to fig. 3, in the second phase T2, the first control signal Wr is at a low level, and the first switch unit 11 is turned on; the second control signal SI is high, the second switch unit 12 is turned off, and the driving transistor M3 exits the diode connection state; the third control signal Em is high, and the third switching unit 16 is turned off; the calculation output unit 15 outputs the data voltage corresponding to Vdt1 calculated by equation (6) to the gate of the driving transistor M3 through the first switching unit 11, and controls the driving transistor M3 to operate.

The first stage T1 is a current extraction and voltage sampling stage, and the calculation output unit 15 preferably does not operate.

The first stage T1 may be set in the power-on stage, between frames, in the row and row stage in the frame, or in the row.

The second stage T2 is a data voltage input stage, and the current drawing unit 13 and the voltage obtaining unit 14 preferably do not operate.

Referring to fig. 3, the third stage T3 is a light emitting stage, the first control signal Wr and the second control signal SI are both at a high level, and the first and

second switch units

11 and 12 are both turned off. The third control signal Em is low and the third switching unit 16 is turned on. In the second phase T2, the data voltage outputted by the calculation output unit 15 and corresponding to Vdt1 controls the driving transistor M3 to drive the light emitting diode L to emit light, and at this time, the light emitting current of the light emitting diode L is Ioled. Because Ioled is the same, the brightness of the LED L is the same, and the uniformity of the whole luminous area is ensured. Therefore, the errors caused by u, Cox, W/L, Vth and the affected operating voltage are all converted into Vdt, so that the light emitting current of the driving transistor M3 is consistent.

In a possible embodiment, when any unknown number of the field effect mobility, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the affected operating voltage has an effect on the display gray scale of the light emitting diode L of less than or equal to 5%, the number of the unknown numbers is decreased by one, and the decreased unknown number is an unknown number of the field effect mobility, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the affected operating voltage having an effect on the display gray scale of the light emitting diode of less than or equal to 5%, so that the current extracting unit 13 can extract the current of the driving transistor M3 once. For example, the influence of the field effect mobility on the display gray scale of the light emitting diode L is less than or equal to 5%, the influence of the field effect mobility on the display gray scale of the light emitting diode L is negligible, which is equivalent to that the field effect mobility is not used as an unknown number of the equation set, the field effect mobility is used as a constant in calculation, at this time, the number of equations in the equation set is 4, Cox, W/L, Vth and the affected operating voltage are 4 unknown numbers of the equation set, and the solution of Cox, W/L, Vth and the affected operating voltage 4 unknown numbers can be solved by the equation set formed by combining the 4 equations. For another example, the influence of the field-effect mobility and the capacitance of the insulating layer on the display gray scale of the light-emitting diode L is less than or equal to 5%, the field-effect mobility and the capacitance of the insulating layer are both constants when calculating, at this time, the number of equations in the equation set is 3, the W/L, Vth and the affected operating voltage are 3 unknowns of the equation set, and the solution of the W/L, Vth and the affected operating voltage of the 3 unknowns can be solved by the equation set formed by combining the 3 equations. The other cases are analogized.

The embodiment presented in fig. 4 differs from the embodiment presented in fig. 2 in that: in the embodiment shown in fig. 4, the first terminal 12a of the second switch unit 12 is electrically connected to the gate of the driving transistor M3, i.e. the second switch unit 12 is connected across the gate and the drain of the driving transistor M3. Otherwise, the rest is the same as the embodiment presented in fig. 2.

The embodiment presented in fig. 6 differs from the embodiment presented in fig. 4 in that: in addition to the embodiment shown in fig. 4, a fifth switch unit 17 is added, a first terminal 17a of the fifth switch unit 17 is electrically connected to the drain of the driving transistor M3, a second terminal 17b of the fifth switch unit 17 is used for inputting a second control signal SI to control the fifth switch unit 17 to turn off or on, and a third terminal 17c of the fifth switch unit 17 is electrically connected to the input terminal of the current drawing unit 13. Otherwise, the rest is the same as the embodiment presented in fig. 4. The fifth switching unit 17 may be, but is not limited to, a PMOS transistor.

The embodiment presented in fig. 8 differs from the embodiment presented in fig. 2 in that: in addition to the embodiment shown in fig. 2, a fifth switch unit 17 is added, a first terminal 17a of the fifth switch unit 17 is electrically connected to the drain of the driving transistor M3, a second terminal 17b of the fifth switch unit 17 is used for inputting a second control signal SI to control the fifth switch unit 17 to turn off or on, and a third terminal 17c of the fifth switch unit 17 is electrically connected to the input terminal of the current drawing unit 13. Otherwise, the rest is the same as the embodiment presented in fig. 2. The fifth switching unit 17 may be, but is not limited to, a PMOS transistor.

The embodiment presented in fig. 10 differs from the embodiment presented in fig. 2 in that: in addition to the embodiment presented in fig. 2, the third switching unit 16 is removed, the drain of the driving transistor M3 is electrically connected to the common ground Vss, and a fourth switching unit 18 is added in series between the source of the driving transistor M3 and the positive pole of the operating voltage, the fourth switching unit 18 being controlled to be turned off or on by the third control signal Em. Otherwise, the rest is the same as the embodiment presented in fig. 2.

The embodiment presented in fig. 12 differs from the embodiment presented in fig. 4 in that: in the embodiment presented in fig. 4, the third switching unit 16 is removed, the drain of the driving transistor M3 is electrically connected to the common ground Vss, and a fourth switching unit 18 is added in series between the source of the driving transistor M3 and the positive pole of the operating voltage, the fourth switching unit 18 being controlled to be turned off or on by the third control signal Em. Otherwise, the rest is the same as the embodiment presented in fig. 4.

The embodiment presented in fig. 14 differs from the embodiment presented in fig. 6 in that: in the embodiment presented in fig. 6, the third switching unit 16 is removed, the drain of the driving transistor M3 is electrically connected to the common ground Vss, and a fourth switching unit 18 is added in series between the source of the driving transistor M3 and the positive pole of the operating voltage, the fourth switching unit 18 being controlled to be turned off or on by the third control signal Em. Otherwise, the rest is the same as the embodiment presented in fig. 6.

The embodiment presented in fig. 16 differs from the embodiment presented in fig. 8 in that: in the embodiment presented in fig. 8, the third switching unit 16 is removed, the drain of the driving transistor M3 is electrically connected to the common ground Vss, and a fourth switching unit 18 is added in series between the source of the driving transistor M3 and the positive pole of the operating voltage, the fourth switching unit 18 being controlled to be turned off or on by the third control signal Em. Otherwise, the rest is the same as the embodiment presented in fig. 8.

The embodiment presented in fig. 18 differs from the embodiment presented in fig. 2 in that: the third switching unit 16 is removed on the basis of the embodiment presented in fig. 2. In the embodiment represented in fig. 18, the drain of the driving transistor M3 is electrically connected to the common ground Vss. Otherwise, the rest is the same as the embodiment presented in fig. 2.

The embodiment presented in fig. 20 differs from the embodiment presented in fig. 4 in that: on the basis of the embodiment presented in fig. 4, the third switching unit 16 is removed. In the embodiment represented in fig. 20, the drain of the driving transistor M3 is electrically connected to the common ground Vss. Otherwise, the rest is the same as the embodiment presented in fig. 4.

The embodiment presented in fig. 22 differs from the embodiment presented in fig. 14 in that: on the basis of the embodiment presented in fig. 14, the fourth switching unit 18 is removed. In the embodiment shown in fig. 22, the source of the driving transistor M3 is electrically connected to the positive electrode of the operating voltage. Otherwise, the rest is the same as the embodiment presented in fig. 14.

The embodiment presented in fig. 24 differs from the embodiment presented in fig. 16 in that: on the basis of the embodiment presented in fig. 16, the fourth switching unit 18 is removed. In the embodiment shown in fig. 24, the source of the driving transistor M3 is electrically connected to the positive electrode of the operating voltage. Otherwise, the rest is the same as the embodiment presented in fig. 16.

The embodiment presented in fig. 26 differs from the embodiment presented in fig. 2 in that: in addition to the embodiment presented in fig. 2, a fourth switching unit 18 is added in series between the source of the driving transistor M3 and the positive pole of the operating voltage, and the fourth switching unit 18 is controlled to be turned off or on by the third control signal Em. In the embodiment shown in fig. 26, the first and

second switch units

11 and 12 are both controlled to be turned off or on by the fourth control signal S & W. The fourth switching unit 18 may be, but is not limited to, a PMOS transistor. Otherwise, the rest is the same as the embodiment presented in fig. 2.

The embodiment presented in fig. 28 differs from the embodiment presented in fig. 26 in that: in the embodiment shown in fig. 28, the first terminal 12a of the second switch unit 12 is electrically connected to the gate of the driving transistor M3, i.e. the second switch unit 12 is connected across the gate and the drain of the driving transistor M3. Otherwise, the rest is the same as the embodiment presented in fig. 26.

The embodiment presented in fig. 30 differs from the embodiment presented in fig. 28 in that: in addition to the embodiment shown in fig. 28, a fifth switch unit 17 is added, a first terminal 17a of the fifth switch unit 17 is electrically connected to the drain of the driving transistor M3, a second terminal 17b of the fifth switch unit 17 is used for inputting a fourth control signal S & W to control the fifth switch unit 17 to turn off or on, and a third terminal 17c of the fifth switch unit 17 is electrically connected to the input terminal of the current drawing unit 13. Otherwise, the rest is the same as the embodiment presented in fig. 28. The fifth switching unit 17 may be, but is not limited to, a PMOS transistor.

The embodiment presented in fig. 32 differs from the embodiment presented in fig. 26 in that: in addition to the embodiment shown in fig. 26, a fifth switch unit 17 is added, a first terminal 17a of the fifth switch unit 17 is electrically connected to the drain of the driving transistor M3, a second terminal 17b of the fifth switch unit 17 is used for inputting a fourth control signal S & W to control the fifth switch unit 17 to turn off or on, and a third terminal 17c of the fifth switch unit 17 is electrically connected to the input terminal of the current drawing unit 13. Otherwise, the rest is the same as the embodiment presented in fig. 26. The fifth switching unit 17 may be, but is not limited to, a PMOS transistor.

The embodiment presented in fig. 34 differs from the embodiment presented in fig. 6 in that: in the embodiment shown in fig. 34, the first switch unit 11 is controlled to be turned on or off by the nth row scanning signal N, and the second switch unit 12 and the fifth switch unit 17 are controlled to be turned on or off by the N-1 th row scanning signal N-1. The third terminal 17c of the fifth switching unit 17 is also electrically connected to the input terminal of the current draw-off unit 13. Otherwise, the rest is the same as the embodiment presented in fig. 6.

The embodiment presented in fig. 36 differs from the embodiment presented in fig. 34 in that: in addition to the embodiment presented in fig. 34, the third switching unit 16 is removed, the drain of the driving transistor M3 is electrically connected to the common ground Vss, and a fourth switching unit 18 is added in series between the source of the driving transistor M3 and the positive pole of the operating voltage, the fourth switching unit 18 being controlled to be turned off or on by the third control signal Em. Otherwise, the rest is the same as the embodiment presented in fig. 34.

The embodiment presented in fig. 38 differs from the embodiment presented in fig. 34 in that: on the basis of the embodiment presented in fig. 34, the third switching unit 16 is eliminated. In the embodiment represented in fig. 38, the drain of the driving transistor M3 is electrically connected to the common ground Vss. Otherwise, the rest is the same as the embodiment presented in fig. 34.

The embodiment presented in fig. 40 differs from the embodiment presented in fig. 34 in that: in addition to the embodiment presented in fig. 34, a fourth switching unit 18 is added in series between the source of the driving transistor M3 and the positive electrode of the operating voltage, and the fourth switching unit 18 is controlled to be turned off or on by the third control signal Em. The fourth switching unit 18 may be, but is not limited to, a PMOS transistor. Otherwise, the rest is the same as the embodiment presented in fig. 34.

The specific operation of the embodiments presented in fig. 4, 6, 8-40 is correspondingly derived as described above with reference to fig. 2 and 3 in conjunction with fig. 5, 7, 9-41.

Referring to fig. 2 to 41, the present invention describes a light emitting diode pixel driving compensation apparatus, the light emitting diode pixel includes a light emitting diode L, a driving transistor M3 for driving the light emitting diode L to emit light in a third stage T3, and first and second switching units 1112 connected in series with each other for controlling the driving transistor M3 to be in a diode connection state in a first stage T1; or the light emitting diode pixel includes a light emitting diode L, a driving transistor driving the light emitting diode L to emit light at the third stage T3, and a second switching unit 12 controlling the driving transistor M3 to be in a diode-connected state at the first stage T1. The compensation device comprises a current extraction unit 13, a voltage acquisition unit 14 and a calculation output unit 15.

The current drawing unit 13 is used for drawing the current of the driving transistor and obtaining the current value of the drawn current in the first stage T1.

The voltage obtaining unit 14 is configured to obtain a voltage value of the gate of the driving transistor corresponding to the obtained current value when the current of the driving transistor is extracted.

The calculation output unit 15 is configured to calculate a solution of an unknown number in the equation set based on the obtained current value, the obtained voltage value and the equation set associated with the saturation region current formula, calculate a data voltage value based on the solution of the equation set, the current value required by the predetermined display gray scale of the light emitting diode and the saturation region current formula, and output a data voltage corresponding to the data voltage value and controlling the driving transistor to drive the light emitting diode to emit light according to the predetermined display gray scale to the gate of the driving transistor in the second stage T2 in the third stage T3.

In the first stage T1, the driving transistor is in a diode connection state, and the unknowns include field effect mobility of the driving transistor, capacitance of the insulating layer, channel width-to-length ratio, threshold voltage, and affected operating voltage.

In a possible embodiment of the led pixel driving compensation apparatus of the present invention, when any unknown number of the field effect mobility, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the affected operating voltage has an effect on the display gray scale of the led less than or equal to 5%, the number of the unknown number is decreased by one, and the decreased unknown number is an unknown number of the field effect mobility, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the affected operating voltage having an effect on the display gray scale of the led less than or equal to 5%.

The working processes of the first switch unit 11, the second switch unit 12, the current extraction unit 13, the voltage acquisition unit 14 and the calculation output unit 15 are as described above.

The invention discloses a light emitting diode pixel driving compensation method, wherein a light emitting diode is driven by a driving transistor to emit light in a third stage, and the method comprises the following steps:

In a possible embodiment of the light emitting diode pixel driving compensation method, when the influence of any unknown number of field effect mobility, the capacitance of the insulating layer, the channel width-length ratio, the threshold voltage and the influenced working voltage on the display gray scale of the light emitting diode is less than or equal to 5%, the number of the unknown numbers is reduced by one, and the reduced unknown numbers are the unknown numbers which have the influence of the field effect mobility, the capacitance of the insulating layer, the channel width-length ratio, the threshold voltage and the influenced working voltage on the display gray scale of the light emitting diode of less than or equal to 5%.

In the embodiments provided by the present invention, it should be understood that the disclosed unit, device and method can be implemented in other ways. For example, the above-described embodiments of units and devices are merely illustrative, and for example, the division of the units is only one logical functional division, and there may be other divisions when the actual implementation is performed, for example, a plurality of units or components may be combined or integrated into another device, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, i.e. may be located in one place, or may be distributed over a plurality of network elements. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, a network device, or the like) or a processor (processor) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium/unit includes: various media capable of storing program codes, such as a Universal Serial Bus flash disk (usb flash disk), a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, and an optical disk.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. A display device comprising a light emitting diode pixel, the light emitting diode pixel comprising a light emitting diode and a driving transistor, characterized in that the light emitting diode pixel further comprises a first and a second switching unit connected in series with each other for controlling the driving transistor to a diode connection state in a first stage; in the third stage, the driving transistor drives the light emitting diode to emit light; the display device includes:

2. A display device comprising light emitting diode pixels according to claim 1, wherein the cathodes of the light emitting diodes are electrically connected to a common ground; the source electrode of the driving transistor is electrically connected with the working voltage anode, and the drain electrode of the driving transistor is electrically connected with the anode of the light-emitting diode; the third end of the first switch unit is electrically connected with the grid electrode of the driving transistor; the first end of the second switch unit is electrically connected with the first end of the first switch unit, and the third end of the second switch unit is electrically connected with the drain electrode of the driving transistor; the second end of the first switch unit is used for inputting a first control signal to control the first switch unit to be closed or opened and the second end of the second switch unit is used for inputting a second control signal to control the second switch unit to be closed or opened, the second end of the first switch unit is used for inputting a fourth control signal to control the first switch unit to be closed or opened and the second end of the second switch unit is used for inputting a fourth control signal to control the second switch unit to be closed or opened, or the second end of the first switch unit is used for inputting an Nth row scanning signal to control the first switch unit to be closed or opened and the second end of the second switch unit is used for inputting an N-1 th row scanning signal to control the second switch unit to be closed or opened; the output end of the calculation output unit is electrically connected with the first end of the first switch unit.

3. The display device according to claim 1, wherein when an influence of any one of the field-effect mobility, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the affected operating voltage on the display gray scale of the light-emitting diode is less than or equal to 5%, the number of the unknowns is reduced by one, and the reduced unknowns are unknowns having an influence on the display gray scale of the light-emitting diode of less than or equal to 5% among the field-effect mobility, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the affected operating voltage.

4. The display device according to claim 2, wherein the led pixel further comprises a third switching unit connected in series between the drain of the driving transistor and the anode of the led, the third switching unit being controlled to be turned off or on by a third control signal.

5. The display device according to claim 1, 2 or 4, wherein the light emitting diode pixel further comprises a fourth switching unit connected in series between the source of the driving transistor and the positive electrode of the operating voltage, and the fourth switching unit is controlled to be turned off or on by a third control signal.

6. The display device according to claim 1, 2 or 4, wherein the led pixel further comprises a fifth switch unit, a first end of the fifth switch unit is electrically connected to the drain of the driving transistor, a second end of the fifth switch unit is used for inputting a second control signal, a fourth control signal or an N-1 th row scanning signal to control the second switch unit to be turned off or turned on, and a third end of the fifth switch unit is electrically connected to the input end of the current extraction unit or the third end of the fifth switch unit is electrically connected to the input ends of the current extraction unit and the voltage acquisition unit.

7. A display device comprising a light emitting diode pixel, the light emitting diode pixel comprising a light emitting diode, a driving transistor for driving the light emitting diode to emit light in a third stage, and a second switching unit for controlling the driving transistor to be in a diode connection state in a first stage; characterized in that, the display device comprises:

8. The display device according to claim 7, comprising a light emitting diode pixel, wherein the cathode of the light emitting diode is electrically connected to a common ground; the source electrode of the driving transistor is electrically connected with the working voltage anode, and the drain electrode of the driving transistor is electrically connected with the anode of the light-emitting diode; the first end of the second switch unit is electrically connected with the grid electrode of the driving transistor, and the third end of the second switch unit is electrically connected with the drain electrode of the driving transistor; the second end of the second switch unit is used for inputting a second control signal to control the second switch unit to be turned off or on, the second end of the second switch unit is used for inputting a fourth control signal to control the second switch unit to be turned off or on, or the second end of the second switch unit is used for inputting an N-1 th row scanning signal to control the second switch unit to be turned off or on.

9. The display device according to claim 7, wherein when an influence of any one of the unknown number of the field-effect mobility, the capacitance of the insulating layer, the channel width/length ratio, the threshold voltage, and the affected operating voltage on the display gray scale of the light-emitting diode is less than or equal to 5%, the number of the unknown number is reduced by one, and the reduced unknown number is an unknown number of the field-effect mobility, the capacitance of the insulating layer, the channel width/length ratio, the threshold voltage, and the affected operating voltage, which influence on the display gray scale of the light-emitting diode is less than or equal to 5%.

10. The device of claim 8, further comprising a third switching unit connected in series between the drain of the driving transistor and the anode of the light emitting diode, wherein the third switching unit is controlled to be turned off or on by a third control signal.

11. The display device according to claim 7, 8 or 10, wherein the led pixel further comprises a fourth switching unit connected in series between the source of the driving transistor and the positive electrode of the operating voltage, and the fourth switching unit is controlled to be turned off or on by a third control signal.

12. The display device according to claim 7, 8 or 10, wherein the led pixel further comprises a fifth switch unit, a first end of the fifth switch unit is electrically connected to the drain of the driving transistor, a second end of the fifth switch unit is used for inputting a second control signal, a fourth control signal or an N-1 th row scanning signal to control the second switch unit to be turned off or turned on, and a third end of the fifth switch unit is electrically connected to the input end of the current extraction unit or the third end of the fifth switch unit is electrically connected to the input ends of the current extraction unit and the voltage acquisition unit.

13. A light emitting diode pixel driving compensation device comprises a light emitting diode, a driving transistor for driving the light emitting diode to emit light in a third stage, and a first switch unit and a second switch unit which are connected in series and control the driving transistor to be in a diode connection state in a first stage; or the light emitting diode pixel comprises a light emitting diode, a driving transistor for driving the light emitting diode to emit light in a third stage, and a second switching unit for controlling the driving transistor to be in a diode connection state in a first stage; characterized in that the compensating device comprises:

14. The led pixel driving compensation device of claim 13, wherein when an effect of any unknown of the field effect mobility, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the affected operating voltage on the display gray scale of the led is less than or equal to 5%, the number of the unknown is decreased by one, and the decreased unknown is an unknown of the field effect mobility, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the affected operating voltage that has an effect on the display gray scale of the led that is less than or equal to 5%.

15. A display device comprising light emitting diode pixels, comprising a light emitting diode pixel drive compensation arrangement according to claim 13 or 14.

16. A method for compensating pixel driving of a light emitting diode driven by a driving transistor to emit light in a third phase, the method comprising the steps of:

17. The led pixel driving compensation method of claim 16, wherein when an effect of any unknown number of the field effect mobility, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the affected operating voltage on the display gray scale of the led is less than or equal to 5%, the number of the unknown number is decreased by one, and the decreased unknown number is an unknown number of the field effect mobility, the capacitance of the insulating layer, the channel width-to-length ratio, the threshold voltage, and the affected operating voltage, which has an effect on the display gray scale of the led less than or equal to 5%.