CN114429749B - Active light-emitting element detection and reverse compensation circuit - Google Patents

Active light-emitting element detection and reverse compensation circuit Download PDF

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Publication number
CN114429749B
CN114429749B CN202210125846.2A CN202210125846A CN114429749B CN 114429749 B CN114429749 B CN 114429749B CN 202210125846 A CN202210125846 A CN 202210125846A CN 114429749 B CN114429749 B CN 114429749B
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compensation
detection
voltage
vsense
driving
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CN114429749A (en
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黄浩
马毅
刘家朝
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Xi'an Xinyuan Micro Technology Co ltd
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Xi'an Xinyuan Micro Technology Co ltd
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    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
    • G09G3/30—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels
    • G09G3/32—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED]
    • G09G3/3208—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED]
    • G09G3/3225—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using electroluminescent panels semiconductive, e.g. using light-emitting diodes [LED] organic, e.g. using organic light-emitting diodes [OLED] using an active matrix
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2320/00—Control of display operating conditions
    • G09G2320/04—Maintaining the quality of display appearance
    • G09G2320/043—Preventing or counteracting the effects of ageing
    • G09G2320/046—Dealing with screen burn-in prevention or compensation of the effects thereof

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)

Abstract

The invention provides an active light-emitting element detection and reverse compensation circuit, which belongs to the field of light-emitting element compensation circuits and comprises an external compensation unit, an external detection data collection unit, an external driving unit and P.S complex detection compensation driving units. The invention aims at the initial T0 of the luminous element to make brightness compensation among luminous element modules, and the brightness of the luminous element is compensated by a voltage compensation mode. Compensating the brightness of the light-emitting element by a voltage compensation mode aiming at the influence of aging of the light-emitting element along with time; compensation can be made for each light-emitting element module. The influence of the Vth shift of the element on the brightness of the light-emitting unit (light-emitting element) is reduced by the characteristics of switching of different driving units and Vth reverse compensation.

Description

Active light-emitting element detection and reverse compensation circuit
Technical Field
The invention belongs to the field of light-emitting element compensation circuits, and particularly relates to an active light-emitting element detection and reverse compensation circuit.
Background
Micro/Mini LED and OLED technology is a display technology which is actively developed by various manufacturers of liquid crystal display panels in recent years. The biggest difference with the traditional LED backlight technology is that the backlight design uses more and smaller (micron-sized) LED chips, and the TFT Liquid Crystal Display (LCD) panel matched with the Micro or Mini LED backlight technology has the advantages of high dynamic contrast (HDR), thinness, high brightness and the like, so that the TFT Liquid Crystal Display (LCD) panel has display image quality similar to that of an organic light emitting diode display (OLED) and is cheaper than an OLED display.
The Micro LED technology is the same as the OLED technology, each pixel display is driven to emit light by an independent Micro LED, and for example, the UD (3840 x 2160) resolution product of the common RGB display is 2488.32 ten thousand pixels, which means that the Micro LED backlight also has the same number of LED chips corresponding to each pixel, so how to implement massive transfer of LEDs to the backlight design is a big subject of the technology.
Because Micro LED manufacturing technology has not yet developed, the concept of Mini LED backlight design has also been proposed. Compared with Micro LED technology, the backlight design uses fewer LED chips, taking UD resolution product as an example, micro LEDs need 2488.32 ten thousand LED chips, but Mini LEDs only need thousands to tens of thousands of LED chips to do backlight design, although the performance of HDR, brightness and the like is not as good as Micro LEDs, the technical difficulty is low, and the image quality of LCD liquid crystal displays can be improved, so that the Micro LED has become one of the key development technologies of various LCD panel manufacturers.
The current-driven light emitting element has two general driving modes: passive driving (PM: passive Matrix) and Active driving (AM: active Matrix). In the circuit design of active driving (AM), each light emitting element has its corresponding independent driving circuit, the driving current is provided by the driving element, and basically, at least two elements are used in each pixel circuit to control the output current, and T1 is the driving element for controlling the on or off of the pixel circuit. T2 is a control element in communication with the voltage source for providing a stable current to the light emitting element. However, the circuit design is affected by the aging problem of the device, which causes the problems of circuit driving and luminance decay of the light-emitting device, and thus the service life of the circuit cannot be long enough.
The first problem is that the luminance of the light emitting element itself also ages with time, and the current corresponding voltage value on the light emitting element also changes with time while the luminance of the light emitting element changes.
Secondly, it is desirable for each manufacturer of liquid crystal display panels to design a driving circuit for light emitting elements on a glass substrate and drive the light emitting elements by thin film elements (TFTs) on the substrate. Currently, most panel manufacturers still use amorphous silicon (a-Si) as a thin film device (TFT) semiconductor active layer, and if the light emitting device driving circuit uses a TFT device of a-Si for driving, the threshold voltage (Vth) of the TFT device shifts by Δvth under long-time high-voltage operation, so that the light emitting device driving current varies, and the light emitting efficiency of the light emitting device is affected, and the relationship between the driving current and Vth is as follows.
I LED ∝(VGS-Vth) 2
In the latest designs, the light-emitting elements of the technology of OLED or Micro and Mini LEDs are driven by active elements on a glass substrate, wherein the circuit design of the matching of the active elements is very critical, and the problems of uniform brightness of the light-emitting elements and no great brightness attenuation after aging are urgently solved. In view of this problem, the present invention provides an active light emitting device detection and reverse compensation circuit.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides an active light emitting device detection and reverse compensation circuit.
In order to achieve the above object, the present invention provides the following technical solutions:
an active light emitting device detection and reverse compensation circuit comprises an external compensation unit, an external detection data collection unit, an external driving unit, and P.S plural detection compensation driving units; the detection compensation driving units are arranged in a matrix, wherein P is the number of matrix columns, and S is the number of matrix rows;
the external detection data collection unit obtains a Vsense (a Vsense detection signal is obtained by the detection unusual drive unit and outputs the Vsense detection signal to the external compensation unit for recording and storing) data to the external compensation unit for recording a Vsense voltage value;
the external compensation unit calculates a voltage value and transmits the voltage value to the external driving unit;
the external driving unit provides circuit signals for the back plate of the light-emitting element according to the received pressure value.
The p×s plural detection compensation driving units are switching element circuits for providing driving voltages and currents for the light emitting elements.
Preferably, the external compensation unit includes a VdataT0 compensation table, a Vdata/Vsense voltage correspondence table DVV, a VsenseTn measurement table, a vsensetn+1 measurement table, and a light emitting device current voltage correspondence table.
Preferably, the circuit signals provided by the external driving unit to the back plate of the light emitting element include VDD, vdata, vcomp and Vc signals.
Preferably, the p×s plural detection compensation driving units include more than 1 set of real-time detection compensation circuits of the detection compensation driving units, wherein the multi-stage real-time detection compensation circuits are in parallel connection structure.
Preferably, the active light emitting element of the real-time detection compensation circuit and the real-time detection compensation circuit are matched with a signal compensation mode, and the single group of detection compensation driving units comprise four subunits which are respectively;
a first subunit including a first drive unit and a second drive unit: for supplying current to the light emitting element and controlling the brightness of the light emitting element;
the second subunit is the detecting unit: when the circuit is used, the voltage value on the light-emitting element can be fed back in real time to confirm whether the brightness of the light-emitting element is aged or not;
the third subunit, the reverse compensation unit: the switching element in the circuit is reversely compensated for ageing problem due to time Vth shift, so that the current of the luminous element is prevented from becoming smaller;
the fourth subunit is a test unit: the brightness testing device is used for testing voltage and current data corresponding to the brightness of the light-emitting element before delivery.
Preferably, the first subunit is a driving unit comprising M groups of driving elements and N light emitting elements, and comprises T1L/R, T2L/R and capacitive CL/R elements and light emitting elements; four signals of Vc1, vc2, vdata1 and Vdata2 are used for controlling four elements of T1L/R and T2L/R, and the VDD signal provides the voltage of the luminous current source stage of the luminous element for T2L/R;
Wherein, M is more than or equal to 4 and more than or equal to 2, and N is more than or equal to 6 and more than or equal to 1.
Preferably, the second subunit is a subunit comprising T4L/R elements; the gate level switch of the T4L/R device is controlled by Vc5 and Vc6 to transmit the detection signals of Vsense1 and Vsense2 to the external detection data collection unit.
Preferably, the third subunit comprises a T3L/R element; the gate level switch of the T3L/R element is controlled by Vc3 and Vc4, and the compensation voltages of Vcomp1 and Vcomp2 are transmitted to T2L/R for reverse compensation.
Preferably, the fourth subunit is configured to test voltage and current data corresponding to brightness of the light emitting element before delivery; the fourth subunit comprises a T5 element; the SC signal controls the gate switch of the T5 device.
Preferably, the detection compensation driving unit comprises two groups of driving switches T2L/T2R and four groups of control switches T1L/T1R/T3L/T3R;
a. only one group of driving switch gate stages is input with the gray-scale voltage Vdata as a driving state at the same time, and the other group of driving switch gate stages is input with the reverse compensation voltage Vcomp as a compensation state; the driving time duty ratio of the two groups of driving switches is 1: (1.+ -. 10%);
b. each group of driving switches is matched with two groups of control switches T1/T3, one group of control gray scale voltage Vdata is input to the gate of the driving switch, the other group of control reverse compensation voltage Vcomp is input to the gate of the driving switch, only one group of control switches are opened in the scanning time of the stage, and the non-scanning time of the stage is that the two groups of control switches are in the closed state.
Preferably, the detection compensation driving unit includes two sets of detection switches T4L/T4R, wherein when one set of driving switches is turned on to a driving state, a corresponding set of detection switches T4L/T4R is turned on, and outputs a detection signal Vsense to the external detection data collecting unit.
Preferably, the external detection data collection unit comprises a plurality of receiving switches SWrx, reset switches SWrst, crx elements and Vsense signals;
in the single-stage detection time, firstly, turning on a reset switch SWrs, turning off a receiving switch and turning off read data, and performing discharging action on Crx; turning on the receiving switch, turning off the reset switch and turning off the read data, and receiving the Vsense signal; and then the Crx voltage data is read, and the reset switch and the receiving switch are turned off at the same time.
Preferably, the external detection data collection unit is disposed on a glass back plate.
Preferably, the source input of the detection switch and the gate Vc5/Vc6 have the same voltage at the non-detection time.
Preferably, the external detection data collection unit is reduced to a P/i stage; wherein i is a set of Vsense data collection of an external detection circuit responsible for several lines of detection compensation driving units;
in the single-stage detection time, there are i cycles, each cycle includes a reset switch, a receiving switch and a read data.
Preferably, the measuring mode of the voltage-current correspondence table of the light emitting element of the test unit is characterized in that:
vc5 or Vc6 and SC signals are High, the ls current source outputs current, other signals are low, and the T4L or T4R and T5 components are opened;
b. controlling the ls current source to output current, measuring the brightness of the light-emitting component at the same time to adjust Vdata voltage so that the overall brightness Is equal, and collecting the voltage value at the end of Vsense1 or Vsense2 of T4L or T4R at the same time to obtain the voltage and current correspondence of the Vsense/Is light-emitting component.
Preferably, the operation characteristic of the Vsense/Vdata voltage mapping table measurement mode of the test unit is as follows:
vc1 or Vc2 is High, T1L or T1R is opened, and a Vdata1 or Vdata2 voltage is used for controlling a T2L or T2R switch to determine a current value for the light emitting component;
b. when the current source of T2L or T2R is controlled to output current, the voltage value can be collected at the end of Vsense1 or Vsense2 of T4L or T4R at the same time, and a Vsense1/Vdata1 or Vsense2/Vdata2 voltage corresponding table can be obtained.
Preferably, the Vsense/Vdata voltage mapping table measures K gray scales for interpolation calculation brightness to be detected in K cycles;
one gray level detection is performed by one detection cycle, wherein one cycle is to measure the Vsense data of S columns; k gray level detection is performed for K detection cycles.
Preferably, the Vsense/Vdata voltage mapping table measurement mode starts the measurement comparison cycle of the Vsense Tn measurement table and the Vsense Tn+1 measurement table when the machine is started each time; when the Vsense detection meter is forced to perform measurement cycle without restarting the machine for a long time, the measurement cycle is performed by adopting the measurement method 2.
Preferably, the vdata_cn compensation method measured by the Vsense/Vdata voltage mapping table is as follows:
a. when Tn, vdata_Cn and Vsense_Tn values are obtained after the Vsense/Vdata voltage mapping table measurement mode is completed;
b. collecting external detection data and reversely compensating and tracking the starting and shutting time of the backlight module, and recording the data of the Vsense_Tn time points of 3-5 groups in a memory, wherein n is the starting and shutting times;
c. comparing vsense_t0 with vsense_tn voltage values, the same current value requires a larger vdata_cn value for the Vth shift curve T2L/R element voltage to be right to adjust vsense_tn back to vsense_t0 (1±10%).
Preferably, the driving process of the driving unit in the detection compensation driving unit is as follows:
when the light-emitting unit is operated by the first driving unit for TL time, after entering TR time, the light-emitting unit is switched to the second driving unit to continuously drive the light-emitting unit, and the first driving unit enters a Vth compensation mode; on the contrary, when the first driving unit is changed to work, the second driving unit is changed to enter a compensation mode;
The voltage Vcomp1 and Vcomp2 must be such that the T2L/R element is in the off state during the compensation mode; the states of the T2L and T2R elements are opposite, but the switching time of the elements is 1: (1.+ -. 10%).
Preferably, for the driving unit in the detection compensation driving unit, if the working voltage Vdata is positive, the compensation voltage Vcomp is negative at T0; compensation voltage vcomp= -VdataX (1±10%).
Preferably, for the driving unit in the detection compensation driving unit, when the scanning period is Tf, the working time of the single driving unit is Td, and the compensation time is Tcomp, where Tcomp is less than or equal to Tf-Td; the compensation time Tcomp is characterized as follows:
a. tcomp increases if Vsense_T (n) > last Vsense_T (n-1), but Tcomp is less than or equal to 1/(T.times.S);
b. tcomp shortens when vsense_t (n) < last vsense_t (n-1).
Preferably, the Vcomp voltage back compensation method is as follows:
a. if the last Vsense_T (n) > the last Vsense_T (n-1) then Vcomp decreases, increasing the reverse compensation value;
b. if Vcomp is increased when Vsense_T (n) < last Vsense_T (n-1), but the Vcomp voltage < Vth, vth is the switching element open voltage.
The active light emitting element detection and reverse compensation circuit provided by the invention has the following beneficial effects:
For the initial T0 of the luminous element, the brightness compensation among the luminous element modules is carried out, and the brightness of the luminous element is compensated by a voltage compensation mode.
Compensating the brightness of the light-emitting element by a voltage compensation mode aiming at the influence of aging of the light-emitting element along with time; the final solution can be to compensate for each light-emitting element module.
The influence of the Vth shift of the element on the brightness of the light-emitting unit (light-emitting element) is reduced by the characteristics of switching of different driving units and Vth reverse compensation.
When the light emitting device is driven and detected by the nth driving unit, the working voltage is P (positive voltage or negative voltage), and the rest driving unit enters a Vth reverse compensation mode, wherein the compensation voltage is N (if the working voltage is positive, N is negative voltage, and the working voltage is negative, N is positive voltage).
When the nth stage driving unit has a larger Vth shift in the operating time, the light emitting element brightness compensation can be performed in combination with the reverse compensation circuit.
Drawings
In order to more clearly illustrate the embodiments of the present invention and the design thereof, the drawings required for the embodiments will be briefly described below. The drawings in the following description are only some of the embodiments of the present invention and other drawings may be made by those skilled in the art without the exercise of inventive faculty.
FIG. 1 is a schematic diagram of an active light emitting device detection and reverse compensation circuit according to embodiment 1 of the present invention;
FIG. 2 is a diagram of a detection compensation driving circuit;
FIG. 3 is a diagram showing the relationship between the external detection data collection unit and the back plate of the light emitting device;
FIG. 4 is a schematic diagram of the external detection voltage required to read the voltage data through the external detection data collection unit;
FIG. 5 is a timing diagram of external detection;
FIG. 6 is a diagram showing a brightness compensation mode of a light emitting device;
FIG. 7 is a timing diagram of a measurement operation of a light emitting element before shipment;
FIG. 8 is a timing diagram of a measurement operation performed before shipment of the light emitting element;
FIG. 9 is a reverse compensation timing diagram of the light emitting device when turned on;
FIG. 10 is a timing diagram of the reverse circuit compensation of the T2L/R device at T0;
FIG. 11 is a timing diagram of the reverse circuit compensation of the T2L/R device at Tn;
FIG. 12 is a schematic circuit diagram of the driving circuit, the detecting circuit and the reverse compensation circuit.
Detailed Description
The present invention will be described in detail below with reference to the drawings and the embodiments, so that those skilled in the art can better understand the technical scheme of the present invention and can implement the same. The following examples are only for more clearly illustrating the technical aspects of the present invention, and are not intended to limit the scope of the present invention.
Example 1
To improve the luminance of a light emitting element by the influence of Vth shift on the driving current of the light emitting element in the long-term operation of a TFT element. The embodiment provides an active light emitting device detection and reverse compensation circuit, as shown in fig. 1 to 12, comprising an external compensation unit, an external detection data collection unit, an external driving unit, and p×s plural detection compensation driving units; the detection compensation driving units are arranged in a matrix, wherein P is the number of matrix columns, and S is the number of matrix rows.
The external detection data collection unit obtains a Vsense (a Vsense detection signal is obtained by the detection unusual drive unit, outputs the Vsense detection signal to the external compensation unit for recording and storing) data and records a Vsense voltage value to the external compensation unit; the external compensation unit calculates a voltage value and transmits the voltage value to the external driving unit; the external driving unit provides circuit signals for the back plate of the light-emitting element according to the received pressure value. The P S plural detection compensation driving units are switching element circuits for providing driving voltages and currents for the light emitting elements.
In this embodiment, the external compensation unit includes a VdataT0 compensation table, a Vdata/Vsense voltage corresponding table DVV, a Vsense measurement table, a vsense+1 measurement table, and a light emitting device current voltage corresponding table.
At least five sets of data record table tables are needed in the external compensation unit, and the data record table tables correspond to the VdataT0 compensation table, the Vdata/Vsense voltage corresponding table (DVV), the Vsense Tn measurement table, the Vsense Tn+1 measurement table and the light-emitting element voltage and current corresponding table respectively.
Vdatat0 compensation table: the initial Vdata voltage is input for the time T0, and the Vdata_C0 value after P.times.S. level compensation after brightness adjustment is corresponding; vdata_c0=lut 1 (Vdata, P, S, T0).
The Vdata/Vsense voltage correspondence table (DVV) is that after the initial Vdata_T0 voltage is input at the time of T0, corresponding to the Vsense value detected by the P.times.S. stage, the Vdata difference value DeltaV corresponding to different Vsense detection values can be compared.
Vsensetn measurement table: detecting the Vsense_Tn-1 value for Tn time P.S, and correspondingly outputting the Vdata_Cn compensation value; vsense_tn-1=lut2 (vdata_cn, P, S).
Vsensetn+1 measurement table: detecting a Vsense_Tn value for Tn time P.S, and correspondingly outputting a Vdata_Cn+1 compensation value; vsense_tn=lut3 (vdata_cn+1, p, s).
5. The light-emitting device voltage-current correspondence table is a P.s-level light-emitting device voltage-current correspondence table measured at T0, and how to measure the relevant data is described in detail later, and the compensation data after the light-emitting device is aged is also included in the table.
Wherein the three groups of tables all comprise D groups of gray level record tables, and each table comprises P-S levels; however, since the division increases the number of the divided tables, the size of the table can be simplified to D groups, and the resolution is reduced to p s levels, wherein the three groups of tables each include D groups of gray-scale recording tables each including PXS levels; however, the division increases the number of the divided tables, so that the size of the table can be simplified to d groups, and the resolution is reduced to the PXS level.
1. Light emitting element voltage-current correspondence table: the measurement of the PXS-level light-emitting device voltage-current correspondence table for T0 is described in detail below.
vsense/Vdata voltage correspondence table: the Vsense/Vdata voltage mapping table for PXS level light is measured at T0, and how to measure the relevant data is described in detail below.
3. The current integration of the light-emitting element is measured according to an aging brightness table: the measurement record is carried out by adopting a single light-emitting element in a laboratory.
4. The brightness aging of the light-emitting element corresponds to the compensation voltage: the measurement record is carried out by adopting a single light-emitting element in a laboratory.
In this embodiment, the external driving unit supplies the circuit signals on the back plate of the light emitting device with VDD, vdata, vcomp and Vc signals.
In this embodiment, the p×s plural detection compensation driving units include real-time detection compensation circuits greater than 1 group of detection compensation driving units, wherein the multi-stage real-time detection compensation circuits are in parallel connection.
In this embodiment, the active light emitting device of the real-time detection compensation circuit and the real-time detection compensation circuit are matched with a signal compensation mode, and the single group of detection compensation driving units comprise four subunits, which are respectively;
a first subunit including a first drive unit and a second drive unit: for supplying current to the light emitting element and controlling the brightness of the light emitting element;
The second subunit is the detecting unit: when the circuit is used, the voltage value on the light-emitting element can be fed back in real time to confirm whether the brightness of the light-emitting element is aged or not;
the third subunit, the reverse compensation unit: the switching element in the circuit is reversely compensated for ageing problem due to time Vth shift, so that the current of the luminous element is prevented from becoming smaller;
the fourth subunit is a test unit: the brightness testing device is used for testing voltage and current data corresponding to the brightness of the light-emitting element before delivery.
In this embodiment, the first subunit is a driving unit including M groups of driving elements and N light emitting elements, and includes T1L/R, T2L/R and capacitive CL/R elements and light emitting elements; four signals of Vc1, vc2, vdata1 and Vdata2 are used for controlling four elements of T1L/R and T2L/R, and the VDD signal provides the voltage of the luminous current source stage of the luminous element for T2L/R;
wherein, M is more than or equal to 4 and more than or equal to 2, and N is more than or equal to 6 and more than or equal to 1.
In this embodiment, the second subunit comprises a T4L/R device; the gate level switch of the T4L/R device is controlled by Vc5 and Vc6 to transmit the detection signals of Vsense1 and Vsense2 to the external detection data collection unit.
In this embodiment, the third subunit comprises T3L/R elements; the gate level switch of the T3L/R element is controlled by Vc3 and Vc4, and the compensation voltages of Vcomp1 and Vcomp2 are transmitted to T2L/R for reverse compensation.
In this embodiment, the fourth subunit is configured to test voltage and current data corresponding to brightness of the light emitting element before delivery; the fourth subunit comprises a T5 element; the SC signal controls the gate switch of the T5 device.
In this embodiment, the detection compensation driving unit includes two sets of driving switches T2L/T2R and four sets of control switches T1L/T1R/T3L/T3R;
a. only one group of driving switch gate stages is input with the gray-scale voltage Vdata as a driving state at the same time, and the other group of driving switch gate stages is input with the reverse compensation voltage Vcomp as a compensation state; the driving time duty ratio of the two groups of driving switches is 1: (1.+ -. 10%);
b. each group of driving switches is matched with two groups of control switches T1/T3, one group of control gray scale voltage Vdata is input to the gate of the driving switch, the other group of control reverse compensation voltage Vcomp is input to the gate of the driving switch, only one group of control switches are opened in the scanning time of the stage, and the non-scanning time of the stage is that the two groups of control switches are in the closed state.
In this embodiment, the detection compensation driving unit includes two sets of detection switches T4L/T4R, wherein when one set of driving switches is turned on to a driving state, a corresponding set of detection switches T4L/T4R is turned on, and outputs a detection signal Vsense to the external detection data collection unit.
In this embodiment, the external detection data collection unit includes P receiving switches SWrx, reset switches SWrst, crx, and Vsense signals;
in the single-stage detection time, firstly, turning on a reset switch SWrs, turning off a receiving switch and turning off read data, and performing discharging action on Crx; turning on the receiving switch, turning off the reset switch and turning off the read data, and receiving the Vsense signal; and then the Crx voltage data is read, and the reset switch and the receiving switch are turned off at the same time.
In this embodiment, the external detection data collection unit is disposed on the glass back plate.
In this embodiment, the source input of the non-detection time detection switch and the gate Vc5/Vc6 have the same voltage.
In this embodiment, the external detection data collection unit is reduced to P/i stage; wherein i is a set of Vsense data collection of an external detection circuit responsible for several lines of detection compensation driving units;
in the single-stage detection time, there are i cycles, each cycle includes a reset switch, a receiving switch and a read data.
In this embodiment, the measuring mode of the voltage-current correspondence table of the light emitting element of the test unit is characterized in that:
vc5 or Vc6 and SC signals are High, the ls current source outputs current, other signals are low, and the T4L or T4R and T5 components are opened;
b. Controlling the ls current source to output current, measuring the brightness of the light-emitting component at the same time to adjust Vdata voltage so that the overall brightness Is equal, and collecting the voltage value at the end of Vsense1 or Vsense2 of T4L or T4R at the same time to obtain the voltage and current correspondence of the Vsense/Is light-emitting component.
In this embodiment, the Vsense/Vdata voltage mapping table measurement mode of the test unit is characterized in that:
vc1 or Vc2 is High, T1L or T1R is turned on and Vdata1 or Vdata2 voltage is used to control T2L or T2R switch to determine the current value to the light emitting component
b. When the current source of T2L or T2R is controlled to output current, the voltage value can be collected at the end of Vsense1 or Vsense2 of T4L or T4R at the same time, and a Vsense1/Vdata1 or Vsense2/Vdata2 voltage corresponding table can be obtained.
In this embodiment, the measurement of the Vsense/Vdata voltage mapping table uses K gray scales for interpolation to calculate the brightness, and K times of cycle detection is required;
one gray level detection is performed by one detection cycle, wherein one cycle is to measure the Vsense data of S columns; k gray level detection is performed for K detection cycles.
In this embodiment, the Vsense/Vdata voltage mapping table measurement mode starts the measurement comparison cycle of the Vsense etn measurement table and the Vsense etn+1 measurement table each time the power is turned on; when the Vsense detection meter is forced to perform measurement cycle without restarting the machine for a long time, the measurement cycle is performed by adopting the measurement method 2.
In this embodiment, the method for compensating Vdata_Cn measured by the Vsense/Vdata voltage mapping table is as follows:
a. when Tn, vdata_Cn and Vsense_Tn values are obtained after the Vsense/Vdata voltage mapping table measurement mode is completed;
b. collecting external detection data and reversely compensating and tracking the starting and shutting time of the backlight module, and recording the data of the Vsense_Tn time points of 3-5 groups in a memory, wherein n is the starting and shutting times;
c. comparing vsense_t0 with vsense_tn voltage values, the same current value requires a larger vdata_cn value for the Vth shift curve T2L/R element voltage to be right to adjust vsense_tn back to vsense_t0 (1±10%).
In this embodiment, the driving process of the driving unit in the detection compensation driving unit is as follows:
when the light-emitting unit is operated by the first driving unit for TL time, after entering TR time, the light-emitting unit is switched to the second driving unit to continuously drive the light-emitting unit, and the first driving unit enters a Vth compensation mode; on the contrary, when the first driving unit is changed to work, the second driving unit is changed to enter a compensation mode;
the voltage Vcomp1 and Vcomp2 must be such that the T2L/R element is in the off state during the compensation mode; the states of the T2L and T2R elements are opposite, but the switching time of the elements is 1: (1.+ -. 10%).
In this embodiment, for the driving unit in the detection compensation driving unit, if the working voltage Vdata is positive, the compensation voltage Vcomp is negative at T0; compensation voltage vcomp= -VdataX (1±10%).
In this embodiment, for the driving unit in the detection compensation driving unit, when the scanning period is Tf, the working time of the single driving unit is Td, and the compensation time is Tcomp, where Tcomp is less than or equal to Tf-Td; the compensation time Tcomp is characterized as follows:
a. tcomp increases if Vsense_T (n) > last Vsense_T (n-1), but Tcomp is less than or equal to 1/(T.times.S);
b. tcomp shortens when vsense_t (n) < last vsense_t (n-1).
In this embodiment, the Vcomp voltage reverse compensation method is as follows:
a. if the last Vsense_T (n) > the last Vsense_T (n-1) then Vcomp decreases, increasing the reverse compensation value;
b. if Vcomp is increased when Vsense_T (n) < last Vsense_T (n-1), but the Vcomp voltage < Vth, vth is the switching element open voltage.
Specifically, in the design of the light-emitting back plate, the present invention provides a p×s plurality of detection compensation driving units, wherein the plurality of detection compensation driving units includes more than 1 group of detection compensation driving units, and provides a real-time detection compensation circuit embodiment of 9T2C, as shown in fig. 2. The circuit consists of two groups of detection compensation driving units and LED light-emitting units, wherein each circuit consists of 9 TFT components and 2 capacitor C components; if three, four, five or more than five sets of … … circuit designs are used, it is still within the scope of the present invention.
The detection compensation driving unit has the following working modes:
1. the whole circuit can be divided into two groups of L/R, each group of L/R comprises a 4T1C circuit, and the two groups of circuits are matched with six groups of signals of Vc1, vc2, vc3, vc4, vc5 and Vc6 for control, wherein Vc4, vc5 can be equal to Vc1, vc3, vc6 can be equal to Vc2 and can also be controlled in a time-sharing manner; the two sets of signals Vc1/Vc4, vc2/Vc3 and Vc5/Vc6 need to be reverse signals, and at the same time, only one set of circuit drives the LED, and the other set of circuit performs reverse compensation.
When the TL time is high, vc1/Vc4/Vc5 and Vc2/Vc3/Vc6 are low, the L groups of circuits are operated in a driving detection mode, and the R groups are operated in a reverse compensation mode; when the TR time is low, vc1/Vc4/Vc5 and Vc2/Vc3/Vc6 are high, the L-group circuit is operated in the reverse compensation mode, and the R-group circuit is operated in the driving detection mode.
3. The signals of the Vsense1 and the Vsense2 which are detected and pulled out in the circuit can be mutually connected or separated, the signal of the Vsense1 is required to be the same as the Vc5 signal when the signal of the Vsense2 is not detected to be the same as the Vc6 signal when the signal of the Vsense1 is not detected to be actuated; this design can alleviate the problem of Vth shift of the T4LT4R switching element, and improve the detection accuracy of Vsense1 and Vsense 2.
The detection voltage reading method comprises the following steps:
as shown in fig. 3 and 5, the external detection voltage is required to read the voltage data through the external detection data collection unit.
1. The light emitting device back plate has a P-stage external detection data collection circuit unit, which can be designed on the glass back plate, the circuit chip or the PCB control circuit board.
2. After all the signals Vsense1 and Vsense2 on the light emitting units in the same column are connected with each other, the detecting data collecting circuit unit includes a reset switch SWrst, a receiving switch SWrx, a reading switch SWread, a Vc voltage switch SWvc and a Cfb storage capacitor.
3. In the single-stage detection time (scanning time), the reset switch is turned on (simultaneously turning off the receiving switch, turning off the reading switch and the Vc voltage switch) to perform discharging action on Crx, then the receiving switch is turned on (simultaneously turning off the reset switch, turning off the reading switch and the Vc voltage switch) to receive the Vsense signal, and then the Crx voltage data is read (simultaneously turning off the reset switch, turning off the receiving switch and the Vc voltage switch).
4. The external IC reads the data and connects out by the read switch, correspond to and look up the voltage data; the external detection data read time is performed at power-on.
5. If the detection read time is performed between on/off, the one-way detection Vfb signal is turned on for 1/(fXS) seconds.
6. Wherein f the light emitting element back plate is the scanning frequency, S is the number of stages of a single column of the light emitting element back plate, and P is the number of stages of a single row of the light emitting element back plate.
The same voltage as Vc5 or Vc6 can be maintained at the non-detection time of Vsense or the signal can be not received.
External time-sharing detection and reading method:
1. the circuitry in the external detection data collection unit can be reduced to P/i stage.
P is the number of stages of a single column of the light emitting element back plate, i is a group of external detection circuits responsible for several columns
3. When the back plate has 200 column drivers, every 4 drivers have one set of external detection circuits, and a total of 200/4=50 sets of external driving circuits.
4. The external detection circuit connection method is the same as that of the previous page description, the external IC read data is connected through Tfb drain, and the external IC read data corresponds to the table look-up voltage data; the external detection data read time is performed at power-on.
5. The Vsense signal in each lighting unit is controlled to be transmitted to the external detection data collection unit by the signal of Vc5 or Vc6 in each lighting unit in a time sharing manner.
6. If the detection read time is performed between on/off, the one-way detection Vfb signal is turned on for i/(fXS) seconds.
7. Wherein f the light emitting element back plate is the scanning frequency, S is the number of stages of a single column of the light emitting element back plate, and P is the number of stages of a single row of the light emitting element back plate.
The same voltage as Vc5 or Vc6 can be maintained in the non-detection time of Vsense or the non-detection time of Vsense can be used for receiving no signal.
9. Wherein f the light-emitting element backboard is the scanning frequency, S is the number of stages of a single column of the light-emitting element backboard, and P is the number of stages of a single row of the light-emitting element backboard; i is a group of external detection circuits responsible for several columns.
At T0, the luminance current and voltage current mapping table is measured:
1. measurement mode 1:
only the Vc5 and SC signals are High, the ls current source outputs current, the other signals are low, and the T4L and T5 devices are turned on.
The ls current source Is controlled to output current, the brightness of the light emitting element Is measured at the same time to adjust Vdata voltage so that the overall brightness Is equal, and the Vsense1 end of T4L can collect the voltage value at the same time to obtain a Vsense/Is light emitting element voltage current corresponding table.
2. Measurement mode 2:
the Vc1 is used to turn on T1L and the Vdata1 voltage is used to control the T2L switch to determine the current value to the light emitting element.
When the T2L current source is controlled to output current, the Vsense1 end of the T4L can collect the voltage value and obtain a Vsense1/Vdata1 voltage corresponding table.
The measurement of the above-mentioned mode 1 and mode 2 or the measurement of only mode 2 can be performed during the detection.
The method of compensating the brightness of the light emitting element is shown in fig. 6.
At T0, the brightness matching compensation method of the light-emitting element comprises the following steps:
1. the L-side circuit is normally operated, vc1, vdata1 and VDD signals are High, and the T1L/T2L/T4L devices are turned on, and the brightness of the light emitting device is confirmed by the voltage value pulled out by Vsense.
2. And calculating the brightness of the light-emitting elements on each stage according to two tables of the brightness of the light-emitting elements corresponding to the Is current and the Vsense voltage corresponding to the Is current, and finally, regulating the brightness difference of each set of light-emitting elements on the backboard to the minimum by improving the Vdata1 voltage compensation through the calculated brightness.
T0vdata1 correction (LED brightness corrected voltage at T0=vdata_c0).
Voltage=vdata_c0 after light emitting element luminance correction at t0.
Vdata_c0 voltage corresponds to light emitting element luminance=target luminance X (1±10%).
6. The target brightness is the brightness with higher picture brightness flatness.
7. Wherein the voltage compensation mode vdata2=vdata1.
8. Meanwhile, the external detection circuit records the value of Vdata_C0 and Vsense_T0.
The measurement operation time sequence is shown in FIG. 7 by measurement mode 1+measurement mode 2:
1. after the Vsense data of all the light emitting elements are measured before the shipment, when T0 is obtained, the brightness matching value vdata_c0 of the light emitting elements and the corresponding vsense_t0 are obtained.
2. When the brightness is calculated by interpolation using K gray scales, K cycle detection is required.
By adopting the measurement mode 2 only, the measurement time before leaving the factory can be reduced, and the measurement operation time sequence is shown in fig. 8:
1. after the Vsense data of all the light emitting elements are measured before the shipment, when T0 is obtained, the brightness matching value vdata_c0 of the light emitting elements and the corresponding vsense_t0 are obtained.
2. When the brightness is calculated by interpolation using K gray scales, K cycle detection is required.
Reverse compensation is performed during starting up:
1. the voltage measurement of measurement method 2 can be repeated once more when turned on to compare Vsense Tn and Vdata Cn.
2. The pressure difference was compared between vsense_tn and vsense_t (n-1) obtained above.
3. The differential pressure value obtained above is calculated and compensated to vcomp_cn.
When the power is turned on/off again for a long time, the reverse compensation is detected and the operation is performed, the operation sequence is as shown in fig. 9:
as shown in fig. 10, at T0, the T2L/R device reverse circuit compensation method:
1. when the driving unit is operated in the driving mode, the gate of the T2L or T2R device is a positive voltage signal (Vdata 1), for example, 10V driving, and the device threshold voltage Vth is biased right after a long time operation.
ILED∝(VGS-Vth)2
2. When the T2L device driving the LED is operated for a period of time, the driving unit is switched to another driving unit T2R device to drive the light emitting device unit, and the gate of the T2L will give a negative voltage signal (Vcomp 1), such as-10V, so as to compensate the Vth of the T2L to the left.
3. If the working voltage Vdata1/Vdata 2 is positive, T0Vcomp1/Vcomp2 is negative voltage;
Vcomp1＝-Vdata1X(1±10％)
Vcomp2＝-Vdata2X(1±10％)
4. the states of the T2L and T2R elements are opposite, but the switching time of the elements is 1: (1.+ -. 10%).
As shown in fig. 11, in Tn, the T2L/R element reverse circuit compensation method, vdata1, cn compensation method:
1. the value of Vdata_C0 and Vsense_T0 will be given to T0 when shipped.
At 2.Tn, the Vdata1 and Vsense voltage offsets will have Vdata_Cn and Vsense_Tn values.
3. External detection data collection and reverse compensation tracking are performed at the starting and shutdown time of the backlight module, and the data of the latest 3-5 groups of Vsense_Tn time points are recorded in the memory, wherein n is the starting and shutdown times.
4. Comparing the Vsense_T0 with the Vsense_Tn voltage value, the same current value requires a larger Vdata_Cn value for the Vth shift curve T2L/R element voltage to be right to adjust the Vsense_Tn value back to Vsense_T0x (1.+ -. 10%).
Vcomp1/Vcomp2 back compensation method:
when the scanning period is Tf, the working time Td of the single driving unit is Tcomp, wherein Tcomp is less than or equal to Tf-Td; the compensation time Tcomp is characterized as follows:
1. tcomp increases if Vsense_T (n) > last Vsense_T (n-1), but Tcomp is less than or equal to 1/(T.times.S).
2. Tcomp shortens if vsense_t (n) < last vsense_t (n-1).
3. If Vsense_T (n) > the last Vsense_T (n-1) then Vcomp decreases, increasing the reverse offset.
4. If Vcomp is increased when Vsense_T (n) < last Vsense_T (n-1), but the Vcomp voltage < Vth, vth is the switching element open voltage.
Vdata1T0 compensation table and VsenseTn measurement table example: 480X270 back panel resolution, brightness is 1024 gray scale.
When the brightness is divided into 1024 (D) steps, the brightness can be simplified to 256 (D) gray scale recording tables, and interpolation calculation is adopted for other gray scale values.
When the number of back plane stages (PXS stage) is 480X270, 4 sets of circuits can be regarded as one record point, and the table is reduced to 240 (p) X135(s).
The overall record table size is reduced to 240 (p) X135(s) X256 (d), reducing the record data by a factor of 16.
9T2C real-time detection compensation circuit driving embodiment:
vc1/Vc4/Vc5 signal is high, vc2/Vc3/Vc6 signal is low:
the L-side circuit drives the light emitting element: when the three elements of T1L, T2L and the capacitor CL are operated, vc1 is high, and Vc3 is low, the T1L is opened to transmit Vdata1 voltage to the T2L gate to control the T2L so as to supply current to the light-emitting element to achieve the control of brightness, and the L side circuit is in a driving detection mode.
L side detection circuit: when Vc5 is high, T4L is turned on, the voltage of the light-emitting element can be transmitted from Vsense1 after T4L is turned on, the table look-up mode corresponds to the time table of current integration aging voltage of the light-emitting element, and then the voltage of Vdata1 is controlled to be used for current compensation of the light-emitting element by T2L.
R side reverse compensation circuit: the gate of T3R is turned on by Vc4 being high, the voltage of Vcomp2 is transmitted to the gate of T2R to control T2R to enter the reverse compensation state, and the circuit at the R side is in the reverse compensation mode.
When the Vc1/Vc4/Vc5 signal is low and the Vc2/Vc3/Vc6 signal is high, the circuit switching operation mode at the two sides of the L/R is performed at the next time sequence.
Wherein the Vc5 signal can be the same as Vc1 or can be separated, and the Vsense1 signal and the Vsense2 signal can be mutually connected or separated; at this time, the T4R device is not activated, the Vsense2 signal is the same as Vc6, and the problem of aging of the T4R device due to Vth shift is avoided.
When Vc1 is high, vc3 must be low; when Vc2 is high, vc4 must be low.
The element Vc4 is high and T2L needs to be in a state of driving the light emitting element, and the element T2R needs to be in an off state.
The Vcomp1 and Vcomp2 voltages must place the T2L/R elements in the off state.
The states of the T2L and T2R elements are opposite, but the switching time of the elements is 1: (1.+ -. 10%).
The Vc1/Vc4/Vc5 signal is low, the Vc2/Vc3/Vc6 signal is high:
the R-side circuit drives the light emitting element: when the three elements T1R, T2R and capacitor CR are operated, vc2 is high, and Vc4 is low, the T1R is turned on to transmit Vdata2 voltage to the gate of the T2R to control the current provided to the light emitting element to achieve brightness control, and the R side circuit is in a driving detection mode.
R side detection circuit: when Vc6 is high, T4R is turned on, the voltage of the light-emitting element can be transmitted from Vsense2 after T4R is turned on, the table look-up mode corresponds to the time table of current integration aging voltage of the light-emitting element, and then the voltage Vdata2 is controlled to compensate the current of the light-emitting element by T2R.
L side reverse compensation circuit: the gate stage T3L is turned on by Vc3 being high, the voltage Vcomp1 is transmitted to the gate stage T2L to control the gate stage T2L to enter a reverse compensation state, and the L side circuit is in a reverse compensation mode.
The next time sequence returns to the circuit switching operation mode at both sides of L/R when the Vc1/Vc4/Vc5 signal is high and the Vc2/Vc3/Vc6 signal is low.
Wherein the Vc6 signal can be the same as Vc2 or can be separated, and the Vsense1 signal and the Vsense2 signal can be mutually connected or separated; at this time, the T4L device is not activated, the Vsense1 signal is the same as Vc5, and the problem of aging of the T4R device due to Vth shift is avoided.
When Vc1 is high, vc3 must be low; when Vc2 is high, vc4 must be low;
vc3 is high, and the T2R element needs to be in a state of driving the light-emitting element, and the T2L element needs to be in a state of being closed;
the Vcomp1 and Vcomp2 voltages must place the T2L/R elements in the off state;
the states of the T2L and T2R elements are opposite, but the switching time of the elements is 1: (1.+ -. 10%).
The above embodiments are merely preferred embodiments of the present invention, the protection scope of the present invention is not limited thereto, and any simple changes or equivalent substitutions of technical solutions that can be obviously obtained by those skilled in the art within the technical scope of the present invention disclosed in the present invention belong to the protection scope of the present invention.

Claims (17)

1. An active light emitting device detection and reverse compensation circuit is characterized by comprising an external compensation unit, an external detection data collection unit, an external driving unit and P.S complex detection compensation driving units; p is the matrix arrangement of S plural detection compensation driving units, wherein P is the matrix column number and S is the matrix line number;
the external detection data collection unit gives the Vsense data to the external compensation unit to record the Vsense voltage value;
the external compensation unit calculates a voltage value and transmits the voltage value to the external driving unit;
the external driving unit provides circuit signals for the back plate of the light-emitting element according to the received pressure value;
the P.S complex detection compensation driving units are switching element circuits for providing driving voltage and current for the light emitting element;
the P.S plural detection compensation driving units comprise more than 1 group of real-time detection compensation circuits of the detection compensation driving units, wherein the multistage real-time detection compensation circuits are of a parallel connection structure;
The active light emitting element of the real-time detection compensation circuit and the real-time detection compensation circuit are matched with a signal compensation mode, and a single group of detection compensation driving units comprise four subunits which are respectively;
a first subunit including a first drive unit and a second drive unit: for supplying current to the light emitting element and controlling the brightness of the light emitting element;
the second subunit is the detecting unit: when the circuit is used, the voltage value on the light-emitting element is fed back in real time to confirm whether the brightness of the light-emitting element is aged or not;
the third subunit, the reverse compensation unit: the switching element in the circuit is reversely compensated for ageing problem due to time Vth shift, so that the current of the luminous element is prevented from becoming smaller;
the fourth subunit is a test unit: the voltage and current data are used for testing the brightness of the light-emitting element before delivery;
the detection compensation driving unit comprises two groups of driving switches T2L/T2R and four groups of control switches T1L/T1R/T3L/T3R;
a. only one group of driving switch gate stages is input with the gray-scale voltage Vdata as a driving state at the same time, and the other group of driving switch gate stages is input with the reverse compensation voltage Vcomp as a compensation state; the driving time duty ratio of the two groups of driving switches is 1: (1.+ -. 10%);
b. Each group of driving switches is matched with two groups of control switches T1/T3, one group of control gray-scale voltage Vdata is input to the gate of the driving switch, the other group of control reverse compensation voltage Vcomp is input to the gate of the driving switch, only one group of control switches are turned on under the current level scanning time, and the current level non-scanning time is that both groups of control switches are turned off;
the external detection data collection unit is reduced to P/i level; wherein i is a set of Vsense data collection of an external detection circuit responsible for several lines of detection compensation driving units;
in the single-stage detection time, i cycles are provided, wherein each cycle comprises a reset switch, a receiving switch and read data;
for the driving unit in the detection compensation driving unit, if the working voltage Vdata is positive, the compensation voltage Vcomp is negative when T0; compensation voltage vcomp= -VdataX (1±10%);
for the driving units in the detection compensation driving unit, when the scanning period is Tf, the working time of the single driving unit is Td, and the compensation time is Tcomp, wherein Tcomp is less than or equal to Tf-Td; the compensation time Tcomp is characterized as follows:
a. tcomp increases if Vsense_T (n) > last Vsense_T (n-1), but Tcomp is less than or equal to 1/(T.times.S);
b. Tcomp shortens when the last vsense_t (n) < last vsense_t (n-1);
the Vcomp voltage reverse compensation method is as follows:
a. if the last Vsense_T (n) > the last Vsense_T (n-1) then Vcomp decreases, increasing the reverse compensation value;
b. if Vcomp is increased when Vsense_T (n) < last Vsense_T (n-1), but the Vcomp voltage < Vth, vth is the switching element open voltage.
2. The circuit of claim 1, wherein the external compensation unit comprises a VdataT0 compensation table, a Vdata/Vsense voltage table DVV, a Vsense Tn table, a Vsense Tn+1 table, and a light emitting device current voltage table.
3. The circuit of claim 1, wherein the external driving unit provides the light-emitting device back plate with circuit signals including VDD, vdata, vcomp and Vc signals.
4. The active light emitting device detection and reverse compensation circuit of claim 1, wherein the first subunit is a driving unit comprising M groups of driving devices and N light emitting devices, the first subunit comprises a gate switch T1L/R, T L/R device, a capacitor CL/R device, and a light emitting device; the T1L/R and T2L/R elements are controlled by four groups of signals Vc1, vc2, vdata1 and Vdata2, and the VDD signal provides the voltage of the luminous current source stage of the luminous element for the gate level switch T2L/R;
Wherein, M is more than or equal to 4 and more than or equal to 2, and N is more than or equal to 6 and more than or equal to 1.
5. The active light emitting device detection and reverse compensation circuit of claim 1, wherein the second subunit comprises a gate switch T4L/R; the gate level switch of the T4L/R device is controlled by Vc5 and Vc6 to transmit the detection signals of Vsense1 and Vsense2 to the external detection data collection unit.
6. The active light emitting device detection and reverse compensation circuit of claim 1, wherein the third subunit comprises a gate switch T3L/R; the gate level switches T3L/R are controlled by Vc3 and Vc4, and the compensation voltages of Vcomp1 and Vcomp2 are transmitted to T2L/R for reverse compensation.
7. The active light emitting device detection and reverse compensation circuit of claim 1, wherein the fourth subunit is configured to test voltage-current data corresponding to brightness of the light emitting device before shipment; the fourth subunit comprises a control switch T5; the SC signal controls the gate switch of the T5 device.
8. The circuit of claim 1, wherein the detection compensation driving unit comprises two sets of detection switches T4L/T4R, wherein when one set of driving switches is turned on, the corresponding set of detection switches T4L/T4R is turned on, and outputs the detection signal Vsense to the external detection data collection unit.
9. The circuit of claim 1, wherein the external detection data collection unit comprises a plurality of receiving switches SWrx and reset switches SWrst, crx, and Vsense;
in the single-stage detection time, firstly, turning on a reset switch SWrs, turning off a receiving switch and turning off read data, and performing discharging action on Crx; turning on the receiving switch, turning off the reset switch and turning off the read data, and receiving the Vsense signal; and then the Crx voltage data is read, and the reset switch and the receiving switch are turned off at the same time.
10. The active light emitting device detection and reverse compensation circuit of claim 1, wherein the external detection data collection unit is disposed on a glass back plate.
11. The circuit of claim 8, wherein the source input of the detection switch and the gate Vc5/Vc6 have the same voltage at the non-detection time.
12. The circuit of claim 6, wherein the measuring mode of the voltage-current correspondence table of the light emitting device of the test unit is characterized by:
Vc5 or Vc6 and SC signal are High, ls current source outputs current, T4L or T4R and T5 components are opened;
b. controlling the ls current source to output current, measuring the brightness of the light-emitting component at the same time outside to adjust Vdata voltage so as to lead the overall brightness to be equal, and collecting the voltage value at the end of Vsense1 or Vsense2 of T4L or T4R at the same time to obtain a voltage-current correspondence table of the Vsense/Is light-emitting component.
13. The circuit of claim 6, wherein the Vsense/Vdata voltage mapping table of the test unit is characterized by:
vc1 or Vc2 is High, T1L or T1R is opened, and a Vdata1 or Vdata2 voltage is used for controlling a T2L or T2R switch to determine a current value for the light emitting component;
b. when the current source of T2L or T2R is controlled to output current, the voltage value can be collected at the end of Vsense1 or Vsense2 of T4L or T4R at the same time, and a Vsense1/Vdata1 or Vsense2/Vdata2 voltage corresponding table can be obtained.
14. The circuit of claim 12 or 13, wherein the Vsense/Vdata voltage mapping table is measured by interpolating K gray scales to calculate the brightness for K cycles;
one gray level detection is performed by one detection cycle, wherein one cycle is to measure the Vsense data of S columns; k gray level detection is performed for K detection cycles.
15. The circuit of claim 12, wherein the Vsense/Vdata voltage mapping table measurement starts a measurement comparison cycle of the Vsense Tn and the Vsense Tn+1 at each power-on; the measurement cycle of the Vsense detection meter is forced to be executed when the machine is not restarted for a long time.
16. The circuit of claim 13 or 15, wherein the method of compensating vdata_cn measured by the Vsense/Vdata voltage mapping table is as follows:
a. when Tn, vdata_Cn and Vsense Tn values are obtained after the Vsense/Vdata voltage corresponding table measurement mode is completed;
b. collecting external detection data and reversely compensating and tracking the starting and shutting time of the backlight module, and recording data of the Vsense_Tn time points of 3-5 groups recently in a memory, wherein n is the starting and shutting times;
c. comparing vsense_t0 with vsense_tn voltage values, the same current value requires a larger vdata_cn value for the Vth shift curve T2L/R element voltage to be right, which can adjust the vsense_tn value back to vsense_t0 (1±10%).
17. The active light emitting device detection and reverse compensation circuit of claim 3, wherein the driving process of the driving unit in the detection and compensation driving unit is:
When the light-emitting unit is operated by the first driving unit for TL time, after entering TR time, the light-emitting unit is switched to the second driving unit to continuously drive the light-emitting unit, and the first driving unit enters a Vth compensation mode; on the contrary, when the first driving unit is changed to work, the second driving unit is changed to enter a compensation mode;
the voltage Vcomp1 and Vcomp2 in the compensation mode causes the T2L/R element to be in the off state; wherein the states of the T2L and T2R elements are opposite, and the switching time of the elements is 1: (1.+ -. 10%).
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