CN115376455A - Pixel unit, display panel and driving method - Google Patents
Pixel unit, display panel and driving method Download PDFInfo
- Publication number
- CN115376455A CN115376455A CN202211197487.8A CN202211197487A CN115376455A CN 115376455 A CN115376455 A CN 115376455A CN 202211197487 A CN202211197487 A CN 202211197487A CN 115376455 A CN115376455 A CN 115376455A
- Authority
- CN
- China
- Prior art keywords
- switch
- voltage
- emitting unit
- light emitting
- unit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 10
- 230000000087 stabilizing effect Effects 0.000 claims description 12
- 239000003990 capacitor Substances 0.000 claims description 11
- 239000000758 substrate Substances 0.000 claims description 7
- 230000000694 effects Effects 0.000 abstract description 10
- 230000002159 abnormal effect Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000002955 isolation Methods 0.000 description 3
- 230000003321 amplification Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- 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]
-
- 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
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
- G09G2330/00—Aspects of power supply; Aspects of display protection and defect management
- G09G2330/04—Display protection
Landscapes
- 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 application discloses a pixel unit, a display panel and a driving method, wherein the pixel unit comprises an overvoltage protection circuit, one end of the overvoltage protection circuit is connected with a data line of the corresponding pixel unit, and the other end of the overvoltage protection circuit is connected between the corresponding light-emitting unit and a power supply; the overvoltage protection circuit is internally provided with a reference voltage, receives the data voltage on the data line, and controls the corresponding light-emitting unit to be disconnected from the power supply when the data voltage on the data line is greater than the reference voltage. Through the design, when a certain data line or a local data line has overvoltage, only a small part of light-emitting units can be disconnected from the power supply, so that the light-emitting units do not emit light, but the display effect of the whole panel is not influenced.
Description
Technical Field
The present disclosure relates to the field of display technologies, and in particular, to a pixel unit, a display panel and a driving method.
Background
With the increasingly complex structures of Micro LEDs and OLED driving panels, the action of high-speed signals inevitably causes data voltage anomalies. For example, in the process of threshold voltage compensation or other voltage compensation, the voltage compensation is inaccurate, which results in abnormal high data voltage; or when the power is turned on or off rapidly, the residual charge in the power-off stage is not released completely, and the power is turned on rapidly, so that an instant overvoltage problem may occur, and the light-emitting device is burnt out.
At present, overvoltage protection circuits are usually designed in a source electrode driving circuit and a grid electrode driving circuit of a display panel to protect devices in the whole display panel, but when overvoltage occurs, namely, when voltage suddenly rises, the whole display panel is black, and the use experience of the display panel is greatly influenced.
Disclosure of Invention
The application aims to provide a pixel unit, a display panel and a driving method, which can avoid the influence on the whole display picture caused by overvoltage in the display panel.
The application discloses a pixel unit, which is applied to a display panel, wherein the display panel comprises a plurality of scanning lines, a plurality of data lines and a plurality of pixel units divided by the plurality of scanning lines and the plurality of data lines, each pixel unit is connected between a light-emitting unit and a power supply, each pixel unit comprises an overvoltage protection circuit, one end of each overvoltage protection circuit is connected with the corresponding data line of the corresponding pixel unit, and the other end of each overvoltage protection circuit is connected between the corresponding light-emitting unit and the corresponding power supply; the overvoltage protection circuit is internally provided with a reference voltage, receives the data voltage on the data line, and controls the corresponding light-emitting unit to be disconnected from the power supply when the data voltage on the data line is greater than the reference voltage.
Optionally, the overvoltage protection circuit includes a comparison unit and a first switch, two input terminals of the comparison unit respectively receive the data voltage and the reference voltage, an output terminal of the comparison unit is connected to a control terminal of the first switch, an input terminal of the first switch is connected to the power supply, and an output terminal of the first switch is connected to the light emitting unit; when the data voltage is greater than the reference voltage, the first switch is closed, so that the light-emitting unit and the power supply are disconnected; when the data voltage is less than or equal to the reference voltage, the first switch is turned on to connect the light emitting unit and the power supply.
Optionally, the overvoltage protection circuit includes a comparison unit, a first switch, a second switch and a third switch, two input ends of the comparison unit respectively receive the data voltage and the reference voltage, an input end of the first switch is connected to the power supply, and an output end of the first switch is connected to the light emitting unit; the control end of the second switch is connected with the output end of the comparison unit, the input end of the second switch is connected with the first level signal line and receives the first level signal, and the output end of the second switch is connected with the control end of the first switch; the control end of the third switch is connected with the output end of the comparison unit, the input end of the third switch is connected with a second level signal line and receives a second level signal, and the output end of the third switch is connected with the control end of the first switch;
wherein the first switch and the second switch have the same switching type, and the first level signal and the second level signal have different types, different from the switching type of the third switch; when the data voltage is greater than the reference voltage, the second switch is turned on, the first switch is turned off, and the light emitting unit and the power supply are disconnected; when the data voltage is less than or equal to the reference voltage, the third switch is turned on, the first switch is turned on, and the light emitting unit and the power supply are connected.
Optionally, the overvoltage protection circuit further includes a fourth switch, the fourth switch is of the same switch type as the first switch, a control end of the fourth switch is connected to an output end of the second switch and an output end of the third switch, an input end of the fourth switch is connected to the light emitting unit, an output end of the fourth switch is grounded, and two ends of the light emitting unit are connected to the first switch and the fourth switch respectively.
Optionally, the threshold voltage of the first switch is greater than the threshold voltage of the second switch, and is also greater than the threshold voltage of the third switch.
Optionally, the pixel unit further includes a voltage stabilizing capacitor, one end of the voltage stabilizing capacitor is connected to one end of the overvoltage protection circuit, which is connected to the data voltage, and the other end of the voltage stabilizing capacitor is connected between the light emitting unit and a ground terminal.
The application also discloses a display panel, which comprises a substrate and the pixel unit, wherein the pixel unit array is arranged on the substrate.
Optionally, each pixel unit in the display panel includes the overvoltage protection circuit.
Optionally, the display panel includes a pixel unit for controlling the red light emitting unit, a pixel unit for controlling the green light emitting unit, and a pixel unit for controlling the blue light emitting unit; wherein the overvoltage protection circuit is provided only in the pixel unit controlling the blue light emitting unit.
The present application also discloses a driving method for driving a pixel cell as described above, comprising the steps of:
an overvoltage protection circuit in the pixel unit receives data voltage on a corresponding data line; and
the overvoltage protection circuit compares the data voltage with a reference voltage, and when the data voltage is greater than the reference voltage, the corresponding overvoltage protection circuit controls the corresponding light-emitting unit to be disconnected from the power supply
Compared with the scheme that overvoltage protection circuits are designed in a source electrode driving circuit and a grid electrode driving circuit of a display panel to protect devices in the whole display panel, the overvoltage protection circuit is additionally arranged in a pixel unit structure to enable the overvoltage protection circuit to control only a single pixel unit, if the data voltage of a data line in the pixel unit is normal, the circuit structure in the pixel unit works normally, when the data voltage of the data line in the pixel unit is abnormal and overvoltage occurs, the overvoltage protection circuit can control a corresponding light-emitting unit to be disconnected from a power supply, and the light-emitting unit is prevented from being damaged due to the fact that the light-emitting unit receives large voltage. When a certain data line or a local data line has overvoltage, only a small part of the light-emitting units can be disconnected with the power supply, so that the light-emitting units do not emit light, but the display effect of the whole panel cannot be influenced, and the screen of the whole panel cannot be extinguished; if overvoltage only occurs for a moment, the display effect of the moment is only influenced, and if overvoltage does not occur repeatedly later, the abnormal display is ended, so that the display effect of the display panel can be guaranteed.
Drawings
The accompanying drawings, which are included to provide a further understanding of the embodiments of the application, are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. It is obvious that the drawings in the following description are only some embodiments of the application, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. In the drawings:
fig. 1 is a schematic diagram of a pixel unit according to a first embodiment of the present application;
fig. 2 is a schematic diagram of a pixel unit according to a second embodiment of the present application;
fig. 3 is a schematic diagram of a pixel unit according to a third embodiment of the present application;
fig. 4 is a schematic diagram of a pixel unit according to a fourth embodiment of the present application;
fig. 5 is a flowchart of a driving method provided in an embodiment of the present application;
fig. 6 is a schematic diagram of a display panel according to an embodiment of the present application.
10, a display panel; 100. a pixel unit; 110. a light emitting unit; 120. an overvoltage protection circuit; 121. a drive compensation circuit; u1, a comparison unit; t1, a first switch; t2, a second switch; t3, a third switch; t4, a fourth switch; t5, a fifth switch; t6, a sixth switch; C. a voltage stabilizing capacitor; 200. a substrate.
Detailed Description
It is to be understood that the terminology, the specific structural and functional details disclosed herein are for the purpose of describing particular embodiments only, and are representative, but that the present application may be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein.
In the description of the present application, the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating relative importance or as implicitly indicating the number of technical features indicated. Further, terms of orientation or positional relationship indicated by "center", "lateral", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, are described based on the orientation or relative positional relationship shown in the drawings, are simply for convenience of description of the present application, and do not indicate that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present application.
The present application is described in detail below with reference to the figures and alternative embodiments.
As shown in fig. 1 to 4 and fig. 6, an embodiment of the present application discloses a pixel unit 100 applied in a display panel 10, where the display panel 10 includes a plurality of scan lines scan, a plurality of data lines data, and a plurality of pixel units 100 divided by the plurality of scan lines and the plurality of data lines, each pixel unit 100 is connected between a light emitting unit 110 and a power supply, and the light emitting unit 110 is a minimum light emitting structure in a Micro LED display panel and an OLED display panel, and may be a light emitting diode.
The pixel unit 100 includes a fifth switch T5 and a sixth switch T6, where the fifth switch T5 and the sixth switch T6 are MOS transistors, the fifth switch T5 is an MOS transistor operating in a cut-off region and a saturation region, the sixth switch T6 is an MOS transistor operating in an amplification region and emitting light from a driving diode, a control end of the fifth switch T5 is connected to the scan line, an input end of the fifth switch T5 is connected to the data line, an output end of the fifth switch T6 is connected to a control end of the sixth switch T6, an input end of the sixth switch T6 is connected to the power supply, an output end of the sixth switch T6 is connected to the light emitting unit 110, and the sixth switch T6 controls the brightness of the light emitting unit 110 according to a voltage output by the fifth switch T5.
Moreover, a driving compensation circuit 121 may be connected between the output terminal of the fifth switch T5 and the control terminal of the sixth switch T6 to compensate for the voltage lost in the circuit due to the wires and components, so that the display panel 10 can maintain a good display effect in each pixel unit 100.
Among the plurality of pixel units 100 of the display panel 10, at least some of the pixel units 100 include an overvoltage protection circuit 120, one end of the overvoltage protection circuit 120 is connected to the data line of the corresponding pixel unit 100, that is, connected to the output end of the fifth switch T5, and the other end is connected between the corresponding light emitting unit 110 and the power supply; a reference voltage vref is provided in the overvoltage protection circuit 120, the overvoltage protection circuit 120 receives the data voltage on the data line, and when the data voltage on the data line is greater than the reference voltage vref, the corresponding overvoltage protection circuit 120 controls the corresponding light emitting unit 110 to disconnect from the power supply.
Compared with the scheme that the overvoltage protection circuit 120 is designed in the source electrode driving circuit and the gate electrode driving circuit of the display panel 10 to protect the devices in the whole display panel 10, the overvoltage protection circuit 120 is additionally arranged in the structure of the pixel unit 100, so that the overvoltage protection circuit 120 only controls a single pixel unit 100, if the data voltage of the data line in the pixel unit 100 is normal, the circuit structure in the pixel unit 100 normally works, and when the data voltage of the data line in the pixel unit 100 is abnormal and overvoltage occurs, the overvoltage protection circuit 120 can control the corresponding light-emitting unit 110 to be disconnected from the power supply, so that the light-emitting unit 110 is prevented from being damaged due to the fact that the light-emitting unit 110 receives large voltage. When a certain data line or a local data line has overvoltage, only a small part of the light-emitting units 110 are disconnected from the power supply, so that the light-emitting units do not emit light, but the display effect of the whole panel is not influenced, and the whole display panel 10 is not turned off; if the overvoltage occurs only for a moment, the display effect of the moment is affected, and if the overvoltage does not occur repeatedly later, the abnormal display is ended, so that the display effect of the display panel 10 can be guaranteed.
In the plurality of pixel units 100 of the display panel 10, the overvoltage protection circuit 120 may be disposed in each of the pixel units 100, so that not only can all pixels be synchronously designed, but also all the light emitting units 110 can be individually controlled by the corresponding overvoltage protection circuit 120, so as to ensure that the light emitting units 110 are not burned out due to overvoltage.
Of course, in the plurality of pixel units 100 of the display panel 10, only the pixel units 100 that are easy to receive unstable electrical signals and the pixel units 100 in the display region that are easy to generate overvoltage may be provided with the overvoltage protection circuit 120 only in these pixel units 100, so that the number of the overvoltage protection circuits 120 in the display panel 10 can be reduced, the total area of the overvoltage protection circuits 120 can be reduced, and the aperture ratio of the display panel 10 can be improved. Specifically, since the light emitting units 110 can generally display red, green, and yellow, that is, the display panel 10 includes the pixel unit 100 controlling the red light emitting unit 110, the pixel unit 100 controlling the green light emitting unit 110, and the pixel unit 100 controlling the blue light emitting unit 110; moreover, the blue light emitting unit 110 generally needs a larger voltage to be driven, and an over-voltage problem is more likely to occur, so that the over-voltage protection circuit 120 is only arranged in the pixel unit 100 for controlling the blue light emitting unit 110, so as to protect the blue light emitting unit 110, and ensure the aperture ratio of the display panel 10.
The reference voltage vref provided in the overvoltage protection circuit 120 can be maintained at the same level as the stable voltage in the data line, so that the change of the data voltage in the data line can be accurately determined in real time, and the overvoltage protection circuit 120 can control the light emitting unit 110 in time. In addition, the reference voltage vref may be larger than the stable voltage in the data line, even if the data voltage fluctuates within a certain range, if the voltage does not increase to the extent that the service life of the light emitting unit 110 is affected, the overvoltage protection circuit 120 may not control the corresponding light emitting unit 110 to disconnect from the power supply, thereby reducing the problem of frequent flicker of the pixel unit 100 due to data voltage fluctuation.
For the overvoltage protection circuit 120 in the pixel unit 100, the following four specific designs are provided in the present application, and it should be noted that these are merely four examples, and it is not limited that the overvoltage protection circuit 120 in the present application can only adopt these four designs, and all of them fall within the scope of the present application as long as the above-mentioned functional effects can be achieved.
The first embodiment is as follows:
as shown in fig. 1, as a first embodiment of the present application, the overvoltage protection circuit 120 includes a comparison unit U1 and a first switch T1, the comparison unit U1 is a voltage comparator, the first switch T1 is a P-type MOS transistor switch, a positive terminal (+) of the comparison unit U1 receives the data voltage, a negative terminal (-) of the comparison unit U1 receives the reference voltage vref, an output terminal of the comparison unit U1 is connected to a control terminal of the first switch T1, an input terminal of the first switch T1 is connected to the power supply Vdd through a sixth switch T6, an output terminal of the first switch T1 is connected to one terminal of the light emitting unit 110, and the other terminal of the light emitting unit 110 is grounded Vss; when the data voltage is greater than the reference voltage vref, the output end of the comparison unit U1 outputs a high level signal to control the first switch T1 to be turned off, so that the light emitting unit 110 and the power supply Vdd are disconnected; when the data voltage is less than or equal to the reference voltage vref, the output end of the comparison unit U1 outputs a low level signal to control the first switch T1 to be turned on, so that the light emitting unit 110 is connected to the power supply Vdd.
In this embodiment, the function of the overvoltage protection circuit 120 can be realized by one comparator and one MOS transistor switch, so that the overvoltage protection circuit 120 has a simple structure, is less in wiring, occupies a small space of the pixel unit 100, and is beneficial to improving the aperture ratio.
Moreover, in order to improve the voltage stabilizing effect of the pixel unit 100, the pixel unit 100 further includes a voltage stabilizing capacitor C, one end of the voltage stabilizing capacitor C is connected to the end of the overvoltage protection circuit 120, which is connected to the data voltage, and the other end of the voltage stabilizing capacitor C is connected between the light emitting unit 110 and a ground terminal Vss, i.e., a cathode of the light emitting diode. Through the design, the stabilizing capacitor samples at the positive input end of the comparison unit U1, does not influence the current and the voltage sampled by the positive input end, does not influence the light emission of the light emitting unit 110, is equivalent to an infinite resistor, and stabilizes the voltage of a point G in a graph, so that the stability of the light emission of the pixel unit 100 is improved, the stability of the overvoltage protection circuit 120 can be improved, and the interference of voltage fluctuation is reduced.
In addition, in the embodiment of the present application, a positive terminal (+) of the comparing unit U1 may further receive the reference voltage vref, a negative terminal (-) of the comparing unit U1 receives the data voltage, and the first switch T1 is an N-type MOS transistor switch; the comparison unit U1 receives the reference voltage and the data voltage, compares the reference voltage and the data voltage, and if the data voltage is greater than the reference voltage, the comparison unit U1 outputs a low level voltage to control the first switch T1 to be turned off, so that the light emitting unit 110 and the power supply are turned off; if the data voltage is less than or equal to the reference voltage, the comparing unit U1 outputs a high level voltage to control the first switch T1 to be turned on, and the light emitting unit 110 is connected to the power supply.
Example two:
as shown in fig. 2, as a second embodiment of the present application, compared with the first embodiment, the present application further includes a fourth switch T4, where the fourth switch T4 and the first switch are of the same type, and may both be P-type MOS switches or both be N-type MOS switches, a control terminal of the fourth switch T4 is connected to an output terminal of the comparison unit U1, an input terminal of the fourth switch T4 is connected to the light emitting unit 110, and an output terminal of the fourth switch T4 is grounded.
In the embodiment of the present application, the MOS switches with the same type are connected to both ends of the light emitting unit 110, so that the light emitting unit 110 is protected by two-sided isolation instead of one-sided isolation, thereby preventing the light emitting unit 110 from being damaged by leakage current, preventing the light emitting unit 110 from being affected by Vdd overload of the power supply, and also preventing the light emitting unit 110 from being affected by ac power.
Example three:
as shown in fig. 3, as a third embodiment of the present application, the overvoltage protection circuit 120 includes a comparison unit U1, a first switch T1, a second switch T2, and a third switch T3, a positive terminal of the comparison unit U1 receives the data voltage, a negative terminal of the comparison unit U1 receives the reference voltage vref, an input terminal of the first switch T1 is connected to the power supply Vdd, and an output terminal of the first switch T1 is connected to the light emitting unit 110; the control end of the second switch T2 is connected to the output end of the comparison unit U1, the input end of the second switch T2 is connected to the first level signal line, receives the first level signal, that is, is connected to the low level signal line, and receives the low level signal, and the output end of the second switch T2 is connected to the control end of the first switch T1; the control end of the third switch T3 is connected to the output end of the comparison unit U1, the input end of the third switch T3 is connected to the second level signal line, receives the second level signal, that is, is connected to the high level signal line, and receives the high level signal, and the output end of the third switch T3 is connected to the control end of the first switch T1;
when the data voltage is greater than the reference voltage vref, the output end of the comparing unit U1 outputs a high level signal, the second switch T2 is turned on to output a low level signal, the first switch T1 is turned off, and the light emitting unit 110 and the power supply Vdd are turned off; when the data voltage is less than or equal to the reference voltage vref, the output end of the comparison unit U1 outputs a low level signal, the third switch T3 is turned on to output a high level signal, the first switch T1 is turned on, and the light emitting unit 110 is connected to the power supply Vdd.
Compared with the first embodiment, the second switch T2 and the third switch T3 are additionally arranged in the embodiment of the present application, and the second switch T2 and the third switch T3 are respectively connected to the low voltage (or the negative voltage) VHL and the positive high voltage VGH, when the display device is turned on, if the VGH is not available, the fifth switch T5 cannot be turned on, the light emitting unit 110 cannot emit light, and the influence of unstable voltage on the light emitting unit 110 during the turn-on is avoided; when the display device is turned off, if the VHL and the VGH are turned off, the light emitting unit 110 does not emit light, so that abnormal display of the light emitting unit 110 caused by incomplete release of residual charges in the turn-off stage is avoided; and when VHL and VGH are turned on, it can also be adjusted according to timing. Also, VHL and VGH are more stable with respect to the voltage signal output by the comparison unit U1, so that the driving of the light emitting unit 110 is more stable.
Further, the threshold voltage of the first switch T1 is greater than the threshold voltage of the second switch T2 and is also greater than the threshold voltage of the third switch T3, so that the second switch T2 and the third switch T3 need relatively smaller voltage to be driven, and the working speed is faster; the first switch T1 is boosted by VGH to ensure that the light emitting unit 110 can be driven, which corresponds to a voltage compensation.
In addition, in this embodiment of the application, a positive terminal of the comparing unit U1 may receive the reference voltage vref, a negative terminal of the comparing unit U1 receives the data voltage, then both the first switch T1 and the second switch T2 are set as P-type MOS transistors, the third switch T3 is set as an N-type MOS transistor, and at this time, the first level signal line connected to the input terminal of the second switch T2 is connected to the high level signal line, and the input terminal of the second switch T2 receives the high level signal; the second level signal line connected to the input terminal of the third switch T3 is a low level signal line, and the input terminal of the third switch T3 receives a low level signal.
When the comparison unit U1 receives the reference voltage and the data voltage, and compares the reference voltage and the data voltage, if the data voltage is greater than the reference voltage, the comparison unit U1 outputs a low level voltage to control the second switch T2 to be turned on, the third switch T3 to be turned off, the second switch T2 outputs a high level signal to turn off the first switch T1, so that the light emitting unit 110 and the power supply are disconnected; if the data voltage is less than or equal to the reference voltage, the comparing unit U1 outputs a high level voltage to control the third switch T3 to be turned on, the second switch T2 to be turned off, and the third switch T3 outputs a low level signal to turn on the first switch T1, so that the light emitting unit 110 and the power supply are turned on.
It should be noted that there are various embodiments in the embodiments of the present application, specific ports for accessing the data voltage and the reference voltage to the comparing unit U1 are not limited, types of the first switch, the second switch, and the third switch are not limited, and voltage signals output by the first level signal line and the second level signal line are also not limited, as long as the connection relationship among the comparing unit, the first switch, the second switch, the third switch, the power supply, and the light emitting unit is satisfied, and the types of the first switch and the second switch are the same, and different from the type of the third switch, and the types of the first level signal and the second level signal are different, so that when the data voltage is greater than the reference voltage, the second switch is turned on, the first switch is turned off, and the light emitting unit is turned off from the power supply; when the data voltage is less than or equal to the reference voltage, the third switch is turned on, the first switch is turned on, and the light-emitting unit and the power supply are communicated.
Example four:
as shown in fig. 4, as a fourth embodiment of the present application, compared with the third embodiment, in the present application, a fourth switch T4 is further added in the overvoltage protection circuit 120, the fourth switch T4 is the same as the first switch T1 in switch type, and may be both N-type MOS transistors or both P-type MOS transistors, and a control terminal of the fourth switch T4 is connected to an output terminal of the second switch T2 and an output terminal of the third switch T3, respectively, an input terminal of the fourth switch T4 is connected to the light emitting unit 110, an output terminal of the fourth switch T4 is grounded, and two terminals of the light emitting unit 110 are connected to the first switch T1 and the fourth switch T4, respectively. After the fourth switch T4 is added, the two ends of the light emitting unit 110 are connected to the MOS transistors of the same type, so that the light emitting unit 110 can be protected by double-sided isolation instead of single-sided protection, thereby preventing leakage current from damaging the light emitting unit 110, preventing Vdd overload of the power supply from affecting the light emitting unit 110, and preventing ac power from affecting the light emitting unit 110.
In addition, the threshold voltages of the first switch T1 and the fourth switch T4 are both greater than the voltage of the second switch T2 and the threshold voltage of the third switch T3. Similarly, the second switch T2 and the third switch T3 only need relatively small voltage to drive, and the working speed is faster; the first switch T1 is boosted by VGH to ensure that the light emitting unit 110 can be driven, which corresponds to a voltage compensation.
As shown in fig. 5, the present application further discloses a driving method for driving the pixel unit 100, which specifically includes the steps of:
s1: an overvoltage protection circuit in the pixel unit receives data voltage on a corresponding data line;
s2: and the overvoltage protection circuit compares the data voltage with a reference voltage, and when the data voltage is greater than the reference voltage, the corresponding overvoltage protection circuit controls the corresponding light-emitting unit to be disconnected from the power supply.
In the step S2, the structure of the overvoltage protection circuit 120 refers to the design in the above specific embodiment, the overvoltage protection circuit 120 may adopt one of the specific designs in the first embodiment, when the data voltage is greater than the reference voltage, the output end of the comparison unit U1 outputs a high level signal, the first switch T1 is controlled to be turned off, and the light emitting unit 110 and the power supply are disconnected; the overvoltage protection circuit 120 may also adopt a specific design in the second embodiment, when the data voltage is greater than the reference voltage, the output end of the comparison unit U1 outputs a high level signal to control the first switch T1 and the fourth switch T4 to be turned off, and the light emitting unit 110 is respectively disconnected from the power supply and the ground end; the overvoltage protection circuit 120 may also adopt a specific design in the third embodiment, when the data voltage is greater than the reference voltage, the output terminal of the comparison unit U1 is controlled to output a high level signal, the second switch T2 is opened to output a low level signal, the first switch T1 is closed, and the light emitting unit 110 and the power supply are disconnected; the overvoltage protection circuit 120 may further adopt a specific design in the fourth embodiment, when the data voltage is greater than the reference voltage, the output terminal of the comparison unit U1 is controlled to output a high level signal, the second switch T2 is turned on to output a low level signal, the first switch T1 and the fourth switch T4 are turned off, and the light emitting unit 110 is respectively disconnected from the power supply and the ground terminal.
In addition, the driving of the light emitting unit 110 includes a reset stage, a threshold voltage detection stage, a threshold voltage compensation stage and a driving light emitting stage, the overvoltage protection circuit 120 in the present application is connected between the output terminal of the fifth switch T5 and the control terminal of the sixth switch T6, and detects the voltage that is not passed through the sixth switch T6 and the light emitting unit 110, when the overvoltage occurs on the data line, the overvoltage protection circuit 120 can control the light emitting unit 110 to be turned off before light emitting, so as to prevent the current from suddenly appearing to cause the light emitting unit 110 to be burned out when light emitting occurs.
As shown in fig. 6, the present application further discloses a display panel 10, which includes a substrate 200 and the pixel units 100, wherein the pixel units 100 are arranged on the substrate 200 in an array.
It should be noted that, the limitations of each step in the present disclosure are not considered to limit the order of the steps without affecting the implementation of the specific embodiments, and the steps written in the foregoing may be executed first, or executed later, or even executed simultaneously, and as long as the present disclosure can be implemented, all the steps should be considered as belonging to the protection scope of the present application.
In addition, the inventive concept of the present application can form a great number of embodiments, but the present application has a limited space and cannot be listed one by one, so that on the premise of no conflict, the above-described embodiments or technical features can be combined arbitrarily to form a new embodiment, and after the embodiments or technical features are combined, the original technical effect will be enhanced.
The foregoing is a more detailed description of the present application in connection with specific alternative embodiments, and the specific implementations of the present application are not to be considered limited to these descriptions. For those skilled in the art to which the present application pertains, several simple deductions or substitutions may be made without departing from the concept of the present application, and all should be considered as belonging to the protection scope of the present application.
Claims (10)
1. A pixel unit applied to a display panel, the display panel including a plurality of scanning lines, a plurality of data lines, and a plurality of pixel units divided by the plurality of scanning lines and the plurality of data lines, each pixel unit being connected between a light emitting unit and a power supply,
the pixel units comprise overvoltage protection circuits, one ends of the overvoltage protection circuits are connected with the data lines of the corresponding pixel units, and the other ends of the overvoltage protection circuits are connected between the corresponding light-emitting units and the power supply;
the overvoltage protection circuit is internally provided with a reference voltage, receives the data voltage on the data line, and controls the corresponding light-emitting unit to be disconnected from the power supply when the data voltage on the data line is greater than the reference voltage.
2. The pixel unit according to claim 1, wherein the over-voltage protection circuit comprises a comparison unit and a first switch, two input terminals of the comparison unit respectively receive the data voltage and the reference voltage, an output terminal of the comparison unit is connected with a control terminal of the first switch, an input terminal of the first switch is connected with the power supply, and an output terminal of the first switch is connected with the light-emitting unit;
when the data voltage is greater than the reference voltage, the first switch is closed, so that the light-emitting unit and the power supply are disconnected; when the data voltage is less than or equal to the reference voltage, the first switch is turned on to connect the light emitting unit and the power supply.
3. The pixel cell of claim 1, wherein the over-voltage protection circuit comprises:
the two input ends of the comparison unit respectively receive the data voltage and the reference voltage;
the input end of the first switch is connected with the power supply, and the output end of the first switch is connected with the light-emitting unit;
the control end of the second switch is connected with the output end of the comparison unit, the input end of the second switch is connected with the first level signal line and receives the first level signal, and the output end of the second switch is connected with the control end of the first switch; and
a control end of the third switch is connected with an output end of the comparison unit, an input end of the third switch is connected with a second level signal line and receives a second level signal, and an output end of the third switch is connected with a control end of the first switch;
wherein the first switch and the second switch have the same switching type, and the first level signal and the second level signal have different types, different from the switching type of the third switch;
when the data voltage is greater than the reference voltage, the second switch is turned on, the first switch is turned off, and the light emitting unit and the power supply are disconnected; when the data voltage is less than or equal to the reference voltage, the third switch is turned on, the first switch is turned on, and the light emitting unit and the power supply are communicated.
4. The pixel unit according to claim 3, wherein the over-voltage protection circuit further comprises a fourth switch, the fourth switch is of the same switch type as the first switch, and a control terminal of the fourth switch is respectively connected to an output terminal of the second switch and an output terminal of the third switch, an input terminal of the fourth switch is connected to the light emitting unit, an output terminal of the fourth switch is grounded, and two terminals of the light emitting unit are respectively connected to the first switch and the fourth switch.
5. The pixel cell of claim 3, wherein the threshold voltage of the first switch is greater than the threshold voltage of the second switch and greater than the threshold voltage of the third switch.
6. The pixel unit according to any one of claims 2-5, further comprising a voltage stabilizing capacitor, wherein one end of the voltage stabilizing capacitor is connected to the end of the overvoltage protection circuit connected to the data voltage, and the other end of the voltage stabilizing capacitor is connected between the light emitting unit and a ground terminal.
7. A display panel comprising a substrate and a pixel cell according to any one of claims 1 to 6, the pixel cell array being disposed on the substrate.
8. The display panel according to claim 7, wherein each of the pixel cells in the display panel comprises the overvoltage protection circuit.
9. The display panel according to claim 7, wherein the display panel includes a pixel unit controlling a red light emitting unit, a pixel unit controlling a green light emitting unit, and a pixel unit controlling a blue light emitting unit;
wherein the overvoltage protection circuit is provided only in the pixel unit controlling the blue light emitting unit.
10. A driving method for driving a pixel cell according to any one of claims 1-8, comprising the steps of:
an overvoltage protection circuit in the pixel unit receives data voltage on a corresponding data line; and
and the overvoltage protection circuit compares the data voltage with a reference voltage, and when the data voltage is greater than the reference voltage, the corresponding overvoltage protection circuit controls the corresponding light-emitting unit to be disconnected from the power supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211197487.8A CN115376455B (en) | 2022-09-29 | 2022-09-29 | Pixel unit, display panel and driving method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211197487.8A CN115376455B (en) | 2022-09-29 | 2022-09-29 | Pixel unit, display panel and driving method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115376455A true CN115376455A (en) | 2022-11-22 |
| CN115376455B CN115376455B (en) | 2023-12-22 |
Family
ID=84072817
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211197487.8A Active CN115376455B (en) | 2022-09-29 | 2022-09-29 | Pixel unit, display panel and driving method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115376455B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115881031A (en) * | 2023-02-09 | 2023-03-31 | 惠科股份有限公司 | Pixel driving circuit, pixel driving method and display panel |
| CN115953985A (en) * | 2022-12-28 | 2023-04-11 | 惠科股份有限公司 | Pixel unit, display panel and display device |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103141002A (en) * | 2010-07-30 | 2013-06-05 | 霍廷格·鲍德温测量技术有限责任公司 | Protective circuit |
| US20170270864A1 (en) * | 2016-03-16 | 2017-09-21 | Samsung Display Co., Ltd. | Display device and electronic device having the same |
| CN107863070A (en) * | 2017-12-22 | 2018-03-30 | 重庆秉为科技有限公司 | A kind of active OLED pixel-driving circuit |
| CN110264925A (en) * | 2019-06-11 | 2019-09-20 | 惠科股份有限公司 | Display device and short circuit detection method thereof |
| US20190340966A1 (en) * | 2018-05-04 | 2019-11-07 | Lg Display Co., Ltd | Data driver circuit, display panel, and display device |
| CN114446224A (en) * | 2022-02-15 | 2022-05-06 | 上海天马微电子有限公司 | Pixel structure, display panel and display device |
| CN114863879A (en) * | 2022-05-23 | 2022-08-05 | 惠科股份有限公司 | Organic light emitting diode control circuit and display panel |
| CN115050321A (en) * | 2022-06-17 | 2022-09-13 | 绵阳惠科光电科技有限公司 | Pixel circuit, pixel circuit driving method and display device |
-
2022
- 2022-09-29 CN CN202211197487.8A patent/CN115376455B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103141002A (en) * | 2010-07-30 | 2013-06-05 | 霍廷格·鲍德温测量技术有限责任公司 | Protective circuit |
| US20170270864A1 (en) * | 2016-03-16 | 2017-09-21 | Samsung Display Co., Ltd. | Display device and electronic device having the same |
| CN107863070A (en) * | 2017-12-22 | 2018-03-30 | 重庆秉为科技有限公司 | A kind of active OLED pixel-driving circuit |
| US20190340966A1 (en) * | 2018-05-04 | 2019-11-07 | Lg Display Co., Ltd | Data driver circuit, display panel, and display device |
| CN110264925A (en) * | 2019-06-11 | 2019-09-20 | 惠科股份有限公司 | Display device and short circuit detection method thereof |
| CN114446224A (en) * | 2022-02-15 | 2022-05-06 | 上海天马微电子有限公司 | Pixel structure, display panel and display device |
| CN114863879A (en) * | 2022-05-23 | 2022-08-05 | 惠科股份有限公司 | Organic light emitting diode control circuit and display panel |
| CN115050321A (en) * | 2022-06-17 | 2022-09-13 | 绵阳惠科光电科技有限公司 | Pixel circuit, pixel circuit driving method and display device |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115953985A (en) * | 2022-12-28 | 2023-04-11 | 惠科股份有限公司 | Pixel unit, display panel and display device |
| CN115953985B (en) * | 2022-12-28 | 2023-11-17 | 惠科股份有限公司 | Pixel unit, display panel and display device |
| CN115881031A (en) * | 2023-02-09 | 2023-03-31 | 惠科股份有限公司 | Pixel driving circuit, pixel driving method and display panel |
| CN115881031B (en) * | 2023-02-09 | 2023-04-28 | 惠科股份有限公司 | Pixel driving circuit, pixel driving method and display panel |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115376455B (en) | 2023-12-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115376455B (en) | Pixel unit, display panel and driving method | |
| US11961477B2 (en) | Pixel driving circuit, and display panel and driving method thereof | |
| CN106486041B (en) | A kind of pixel circuit, its driving method and related display apparatus | |
| US10181283B2 (en) | Electronic circuit and driving method, display panel, and display apparatus | |
| US8963907B2 (en) | Pixel circuit and driving method thereof | |
| CN106531079B (en) | Pixel circuit, driving method thereof and display device | |
| US20200043411A1 (en) | Power off method of display device, and display device | |
| CN110689840B (en) | Pixel circuit, short circuit detection method and display panel | |
| CN112908264B (en) | Pixel driving circuit, driving method, display panel and display device | |
| CN108682385B (en) | Pixel circuit, pixel driving method and display device | |
| CN111477166A (en) | Pixel circuit, pixel driving method and display device | |
| CN112397025A (en) | Pixel circuit, driving method thereof and display panel | |
| CN113593470B (en) | Light emitting device driving circuit, backlight module and display panel | |
| CN112530368B (en) | Pixel circuit, display panel and display device | |
| US11620939B2 (en) | Pixel driving circuit and driving method therefor, display panel, and display apparatus | |
| CN113436577A (en) | Display panel, driving method thereof and display device | |
| CN114495825A (en) | Pixel driving circuit, driving method, display panel and display device | |
| CN115050321B (en) | Pixel circuit, pixel circuit driving method and display device | |
| KR20190132525A (en) | Scan Driver, Scan Driver and Display Device | |
| CN113823221B (en) | Driving circuit of display panel, compensation method of display panel and display device | |
| US11935444B2 (en) | Detection circuit, driving circuit, and display panel and driving method therefor | |
| CN109243361B (en) | Pixel unit | |
| CN113241036B (en) | Pixel driving circuit, pixel driving method and display device | |
| CN108877646B (en) | Display circuit and display | |
| US20240069584A1 (en) | Voltage stabilizing circuit and display panel |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |