WO2021184472A1 - 像素电路及显示面板 - Google Patents

像素电路及显示面板 Download PDF

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Publication number
WO2021184472A1
WO2021184472A1 PCT/CN2020/084823 CN2020084823W WO2021184472A1 WO 2021184472 A1 WO2021184472 A1 WO 2021184472A1 CN 2020084823 W CN2020084823 W CN 2020084823W WO 2021184472 A1 WO2021184472 A1 WO 2021184472A1
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Prior art keywords
circuit
pixel
pixel circuit
voltage
signal
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PCT/CN2020/084823
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English (en)
French (fr)
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陈勇
李骏
孙亮
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武汉华星光电半导体显示技术有限公司
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Priority to US16/957,113 priority Critical patent/US11727881B2/en
Publication of WO2021184472A1 publication Critical patent/WO2021184472A1/zh

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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]
    • 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
    • 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
    • G09G3/3233—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 with pixel circuitry controlling the current through the light-emitting element
    • G09G3/3241—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 with pixel circuitry controlling the current through the light-emitting element the current through the light-emitting element being set using a data current provided by the data driver, e.g. by using a two-transistor current mirror
    • 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
    • G09G3/3233—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 with pixel circuitry controlling the current through the light-emitting element
    • 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]
    • G09G3/3266—Details of drivers for scan electrodes
    • 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]
    • G09G3/3275—Details of drivers for data electrodes
    • G09G3/3291—Details of drivers for data electrodes in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2300/00—Aspects of the constitution of display devices
    • G09G2300/08—Active matrix structure, i.e. with use of active elements, inclusive of non-linear two terminal elements, in the pixels together with light emitting or modulating elements
    • G09G2300/0876—Supplementary capacities in pixels having special driving circuits and electrodes instead of being connected to common electrode or ground; Use of additional capacitively coupled compensation electrodes

Definitions

  • the present invention relates to the field of display, in particular to a pixel circuit and a display panel.
  • FIG. 1 it is a schematic diagram of the structure of an existing under-screen camera display panel.
  • the under-screen camera display panel 90 includes a flexible substrate layer 91, an array substrate 92, a light-emitting layer 93, and an encapsulation layer which are sequentially stacked from bottom to top. 94.
  • Polarizer 95 and cover 96 Polarizer 95 and cover 96.
  • a through hole is provided at the corresponding position of the array substrate 92 and the polarizer 95 to form a blind hole 97.
  • the lens can be hidden below the displayable area of the screen. Finish shooting.
  • the under-screen camera solution in order to increase the light transmittance of the under-screen camera area, when using the classic 7T1C circuit of an organic light-emitting diode (OLED) display, in order to increase the light transmittance of the under-screen camera area, the pixel design needs to be optimized to reduce The pixel density of the camera area under the screen is partially transparent.
  • Mounting 2T1C pixel circuit above the under-screen camera area can reduce pixel density very well. Due to the small area of the under-screen camera area, the 2T1C pixel circuit has little effect on the display screen, but the current 2T1C pixel circuit operating voltage is not within the normal data voltage range given by the driver circuit, so the under-screen camera area is equipped with traditional 2T1C pixel circuits Undesirable.
  • the purpose of the present invention is to provide a pixel circuit and a display panel, by changing the circuit structure of the camera area under the screen, to achieve the effect of improving light transmittance.
  • the present invention provides a pixel circuit, including a data line, a scan line, a number of levels of 2T1C circuits, a step-down circuit, and a reset circuit;
  • the data line is used to transmit a source data signal (Source data);
  • the scan Lines are used to transmit scan signals;
  • the input terminals of several levels of 2T1C circuits are connected in parallel to the scan line;
  • the input terminal of the step-down circuit is connected to the data line, and the output terminal is connected to the other input terminal of each 2T1C circuit ;
  • the reset circuit is connected to the input terminal of the step-down circuit.
  • the reset circuit includes a first drive transistor (T1), the source of which inputs a reset voltage signal (VI), the drain of which is connected to the other input terminal of each 2T1C circuit, and the gate of which inputs an AC voltage Signal (VR); when the AC voltage signal (VR) is at a low level, the voltage of the reset voltage signal (VI) is written into the 2T1C pixel circuit to reset it.
  • T1 first drive transistor
  • V reset voltage signal
  • V AC voltage Signal
  • the step-down circuit includes a second drive transistor (T2), the source of which inputs a source data signal, and the gate and drain of which are connected to the other input of each 2T1C circuit; when the 2T1C pixel circuit
  • the scan signal (Scan(n)) is low level, the voltage of the source data signal (Source data) is captured by the second drive transistor (T2) for the threshold voltage (Vth) and then written into the 2T1C pixel Circuit.
  • the timing of the AC voltage signal (VR) is synchronized with the timing of the multiplexer (Mux) signal.
  • the pixel circuit further includes a voltage stabilizing capacitor (C), one end of which is electrically connected to the positive power supply voltage (VDD), and the other end of which is electrically connected to the input terminal of the 2T1C pixel circuit.
  • the voltage stabilizing capacitor (C) Used to stabilize the voltage input to the 2T1C pixel circuit.
  • the present invention also provides a display panel including the above-mentioned pixel circuit.
  • the display panel includes an under-screen camera area and a display area arranged around the under-screen camera area, and the 2T1C pixel circuit is arranged in the under-screen camera area.
  • the under-screen camera area includes a number of second pixel units arranged in a longitudinal direction and a number of first pixel units arranged in a longitudinal direction; the second pixel unit includes the 2T1C pixel circuit, and a number of the second pixel units.
  • Each input terminal of the pixel unit is connected in parallel to the scan line, and the other input terminal is connected to the output terminal of the step-down circuit;
  • the first pixel unit includes a 7T1C pixel circuit, and its input terminal is connected to the data line
  • the plurality of second pixel units arranged along the longitudinal direction and the plurality of first pixel units arranged along the longitudinal direction are arranged at intervals along the transverse direction.
  • the distribution density of the plurality of first pixel units arranged in the longitudinal direction is smaller than the distribution density of the plurality of second pixel units arranged in the longitudinal direction.
  • the display area includes a plurality of data lines extending in the longitudinal direction and a plurality of first pixel units, and the first pixel units include 7T1C pixel circuits, the input terminals of which are connected to the data lines.
  • the beneficial effect of the present invention is to provide a pixel circuit and a display panel, which can achieve the effect of improving the light transmittance by changing the circuit structure of the camera area under the screen.
  • FIG. 1 is a schematic diagram of the structure of an existing under-screen camera display panel
  • Figure 2 is a schematic diagram of the structure of a 2T1C pixel circuit
  • FIG. 3 is a timing diagram of the scan signal Scan in the 2T1C pixel circuit shown in FIG. 2;
  • FIG. 4 is a simulation result diagram of the 2T1C pixel circuit shown in FIG. 2;
  • FIG. 5 is a schematic structural diagram of a 7T1C pixel circuit
  • FIG. 6 is a timing diagram of the 7T1C pixel circuit shown in FIG. 5;
  • FIG. 7 is a simulation result diagram of the 7T1C pixel circuit shown in FIG. 5;
  • FIG. 8 is a schematic structural diagram of a pixel circuit in an embodiment of the present invention.
  • FIG. 9 is a simulation result diagram of the pixel circuit shown in FIG. 8.
  • FIG. 10 is a schematic diagram showing that the Mux_G signal is compatible with the AC voltage signal (VR) of the 2T1C pixel circuit;
  • FIG. 11 is a schematic diagram of a partial structure of the display panel.
  • connection should be understood in a broad sense, unless otherwise clearly specified and limited.
  • it can be a fixed connection or a detachable connection.
  • Connected or integrally connected it can be mechanically connected, or electrically connected or can communicate with each other; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal communication of two components or the interaction of two components relation.
  • an intermediate medium it can be the internal communication of two components or the interaction of two components relation.
  • the 2T1C pixel driving circuit includes a first thin film transistor T10, a second thin film transistor T20, a storage capacitor Cst, and an organic light emitting element OLED.
  • the gate of the first thin film transistor T10 is electrically connected to the scan signal Scan.
  • the timing diagram of the scan signal Scan is shown in FIG.
  • One end of the storage capacitor Cst is electrically connected; the source of the second thin film transistor T20 is electrically connected to the positive power supply voltage VDD, and the drain is electrically connected to the anode of the organic light emitting diode OLED; the cathode of the organic light emitting diode OLED
  • the storage capacitor Cst is electrically connected to the negative power supply voltage VSS; one end of the storage capacitor Cst is electrically connected to the drain of the first thin film transistor T10, and the other end is electrically connected to the source of the second thin film transistor T20.
  • the scan signal Scan controls the first thin film transistor T10 to turn on, and the data signal Data enters the gate of the second thin film transistor T20 and the storage capacitor Cst through the first thin film transistor T10, and then the first thin film transistor T10 is turned off.
  • the gate voltage of the second thin film transistor T20 can continue to maintain the data signal voltage, so that the second thin film transistor T20 is in the on state, and the driving current enters the organic light emitting diode OLED through the second thin film transistor T20 to drive The organic light emitting diode OLED emits light.
  • the 2T1C pixel circuit does not capture the threshold voltage Vth, keeping the size of the thin film transistor and the storage capacitor consistent with the classic 7T1C circuit.
  • the Data voltage written by the first transistor T10 is 3.0V, according to the simulation result of Figure 4, it can be seen that the second thin film The gate voltage Q point of the transistor T20 is connected to the drain of the first thin film transistor T10 to reach 3.4V, so there is no Vth capture of the 7T1C circuit.
  • the 7T1C pixel circuit includes: a first transistor M1, a second transistor M2, a third transistor M3, a fourth transistor M4, a fifth transistor M5, and a sixth transistor.
  • M6 a seventh transistor M7, a storage capacitor Cst, and an organic light-emitting element OLED.
  • the gate of the first transistor M1 is connected to the first end of the storage capacitor Cst, the first electrode of the first transistor M1 is connected to the first electrode of the second transistor M2, and the first transistor M1
  • the second electrode of is connected to the first electrode of the third transistor M3.
  • the gate of the second transistor M2 is connected to the second scan signal terminal Scan(n), and the second electrode of the second transistor M2 is connected to the data signal terminal Vdata.
  • the gate of the third transistor M3 is connected to the second scan signal terminal Scan(n), and the second electrode of the third transistor M3 is connected to the first terminal of the storage capacitor Cst.
  • the second terminal of the storage capacitor Cst is connected to the first voltage signal terminal VDD.
  • the gate of the fourth transistor M4 is connected to the first scan signal terminal Scan(n-1), the first electrode of the fourth transistor M4 is connected to the first terminal of the storage capacitor Cst, and the fourth transistor The second electrode of M4 is connected to the initialization signal terminal Vi.
  • the gate of the fifth transistor M5 is connected to the control signal terminal EM, the first electrode of the fifth transistor M5 is connected to the first voltage signal terminal VDD, and the second electrode of the fifth transistor M5 is connected to the The first electrode of the first transistor M1 is connected.
  • the gate of the sixth transistor M6 is connected to the control signal terminal EM, the first electrode of the sixth transistor M6 is connected to the second electrode of the first transistor M1, and the second electrode of the sixth transistor M6 is The electrode is connected to the anode of the organic light emitting element OLED.
  • the cathode of the organic light emitting element OLED is connected to the second voltage signal terminal VSS.
  • the gate of the seventh transistor M7 is connected to the second scan signal terminal Scan(n), the first electrode of the seventh transistor M7 is connected to the initialization signal terminal Vi, and the first electrode of the seventh transistor M7 The two electrodes are connected with the anode of the organic light emitting element OLED.
  • the third transistor M3 includes two sub-transistors connected in series, the gate of the first sub-transistor M31 is connected to the second scan signal terminal Scan(n), and the first electrode of the first sub-transistor M31 Is connected to the second electrode of the second sub-transistor M32, the second electrode of the first sub-transistor M31 is connected to the first end of the storage capacitor Cst; the gate of the second sub-transistor M32 is connected to the second scan signal The terminal Scan(n) is connected, and the first electrode of the second sub-transistor M32 is connected to the second electrode of the first transistor M1.
  • the fourth transistor M4 includes two sub-transistors connected in series, the gate of the third sub-transistor M41 is connected to the first scan signal terminal Scan(n-1), and the third sub-transistor M41 A Tina is connected to the first terminal of the storage capacitor Cst, the second electrode of the third sub-transistor M41 is connected to the first electrode of the fourth sub-transistor M42; the gate of the fourth sub-transistor M42 is connected to The first scan signal terminal Scan(n-1) is connected, and the second electrode of the fourth sub-transistor M42 is connected to the initialization signal terminal Vi.
  • the first terminal of the storage capacitor Cst, the gate of the first transistor M1, the second electrode of the third transistor M3, and the first electrode of the fourth transistor M4 are electrically connected to each other.
  • the timing diagram of the 7T1C pixel circuit is shown in FIG. 6.
  • the first scan signal terminal Scan(n-1) provides a low-level signal
  • the fourth transistor M4 is turned on
  • the initialization signal Vi passes
  • the fourth transistor M4 initializes the storage capacitor Cst.
  • the second scan signal terminal Scan(n) provides a low-level signal
  • the second transistor M2 and the third transistor M3 are turned on
  • the signal provided by the data signal terminal Data affects the storage capacitor Cst.
  • the first end of the battery is charged until the first transistor M1 is turned off. Maintain the conventional thin film transistor size and storage capacitor size in the 7T1C pixel circuit.
  • the simulation result is shown in Figure 7.
  • the written Data voltage is 3.0V
  • the gate voltage of the first transistor M1 reaches 1.4V due to its Vth extraction
  • the written VDD voltage in the 7T1C pixel circuit is 4.6V.
  • VSS is -4.0V.
  • the simulation result shows that the current through the OLED is 18nA.
  • the current flowing through the OLED in the 2T1C pixel circuit is at least 3 orders of magnitude different from the current flowing through the OLED in the 7T1C pixel circuit. That is, for the 2T1C pixel circuit, to achieve the same current value as the 7T1C pixel circuit, Write a smaller Data voltage.
  • the Data value range of 7T1C pixel circuit is about 3.0V-6.0V; the Data value range corresponding to 2T1C pixel circuit is about 0.5V-3.5V, and the working voltage of 2T1C pixel circuit is not the normal data voltage given by the drive circuit. Therefore, it is not advisable to carry 2T1C pixel circuit in the camera area under the screen.
  • the applicant has conducted research to provide a pixel circuit and a display panel, which can implement a 2T1C pixel circuit mounted in the camera area under the screen to improve light transmittance.
  • an embodiment of the present invention provides a pixel circuit including a data line, a scan line, a number of levels of 2T1C circuits, a step-down circuit, and a reset circuit;
  • the data line is used to transmit source data signals (Source data);
  • the scan line is used to transmit scan signals;
  • the input terminals of the several levels of 2T1C circuits are connected in parallel to the scan line;
  • the input terminal of the step-down circuit is connected to the data line, and the output terminal is connected to each The other input terminal of the 2T1C circuit;
  • the reset circuit is connected to the input terminal of the step-down circuit.
  • the reset circuit includes a first drive transistor (T1), the source of which inputs a reset voltage signal (VI), the drain of which is connected to the other input terminal of each 2T1C circuit, and the gate of which inputs an AC voltage Signal (VR); when the AC voltage signal (VR) is at a low level, the voltage of the reset voltage signal (VI) is written into the 2T1C pixel circuit to reset it.
  • T1 first drive transistor
  • V reset voltage signal
  • V AC voltage Signal
  • the step-down circuit includes a second driving transistor (T2), the source of which inputs a source data signal, and the gate and drain of which are connected to the other input terminal of each 2T1C circuit; that is, the second driving transistor (T2)
  • the gate and drain of the transistor (T2) are electrically connected to each other and to the drain of the first driving transistor (T1); the input terminals of all the 2T1C pixel circuits are connected to the first driving transistor (T1)
  • the drain of the second driving transistor (T2) is electrically connected; when the AC voltage signal (VR) is low, the voltage of the reset voltage signal (VI) is written into the 2T1C pixel circuit, so that It resets; when the AC voltage signal (VR) is at a high level and the scan signal (Scan(n)) of the 2T1C pixel circuit is at a low level, the voltage of the source data signal (Source data) passes through the The second driving transistor (T2) captures the threshold voltage (Vth) and writes it into the 2T1C pixel
  • FIG. 2 The structure diagram of the 2T1C pixel circuit is shown in FIG. 2, and the simulation result of the pixel circuit is shown in FIG. 9.
  • Sn, Sn+1, and Sn+2 represent the scanning of the 2T1C pixel circuit.
  • the reset voltage signal (VI) is a negative voltage, preferably -3V.
  • the voltage of the source data signal (Source data) is a high positive voltage
  • the threshold voltage (Vth) is captured by the second driving transistor (T2) and then reduced to a low positive voltage.
  • the 2T1C pixel circuit is a high positive voltage
  • the voltage value of the threshold voltage (Vth) of the second driving transistor (T2) is the difference between the operating voltage value of the 2T1C pixel circuit and the voltage value of the source data signal (Source data).
  • the voltage of the source data signal (Source data) is a high positive voltage 2.5V-5.5V
  • the threshold voltage (Vth) of the second driving transistor (T2) is preset to -2.5V
  • the source The data signal (Source data) is captured by the threshold voltage (Vth) and then reduced to a low positive voltage 0V-3V.
  • the low positive voltage 0V-3V is the same as the operating voltage range of the 2T1C pixel circuit, so it can be directly written to the
  • the 2T1C pixel circuit can be implemented to mount the 2T1C pixel circuit in the camera area under the screen, which improves the light transmittance.
  • the current formula of the pixel circuit is:
  • u n representative of the mobility denotes a gate oxide capacitance
  • W / L aspect ratio of the representative channel thin film transistor Vgs denotes a gate voltage
  • Vth a threshold voltage of the representative.
  • the current formula calculation and verification of the pixel circuit shows that the current flowing through the organic light-emitting element OLED of the 2T1C pixel circuit is consistent with the current flowing through the organic light-emitting element OLED of the 7T1C pixel circuit.
  • the operating voltage range of the pixel circuit is the same as that of the 7T1C pixel circuit.
  • the timing of the AC voltage signal (VR) is synchronized with the timing of the multiplexer (Mux) signal.
  • the AC voltage signal (VR) can be provided by a multiplexer (Mux).
  • the Mux_G signal can be compatible with the AC voltage signal (VR) of the above-mentioned 2T1C pixel circuit, without the need for an integrated circuit (IC) to provide additional signals.
  • the pixel circuit further includes a voltage stabilizing capacitor (C), one end of which is electrically connected to the positive power supply voltage (VDD), and the other end of which is electrically connected to the input end of the 2T1C pixel circuit.
  • the voltage capacitor (C) is used to stabilize the voltage input to the 2T1C pixel circuit.
  • the positive power supply voltage (VDD) is a fixed voltage, preferably 4.6V.
  • FIG. 11 is a schematic diagram of a partial structure of the display panel. As shown in FIG. 11, the present invention also provides a display panel 100 including the above-mentioned pixel circuit.
  • the display panel 100 includes an under-screen camera (CUP) area 10 and a display area 20 arranged around the under-screen camera area 10, and the 2T1C pixel circuit is arranged in the under-screen camera area 10.
  • CUP under-screen camera
  • the display area 20 includes a plurality of scan lines (not shown) extending in a first direction, a plurality of data lines 1 extending in a second direction, and two adjacent scan lines and two adjacent data lines.
  • the first pixel unit 11 includes a 7T1C pixel circuit; the second direction is different from the first direction.
  • the first direction is preferably horizontal.
  • the second direction is the longitudinal direction, so the display area 20 includes a plurality of data lines 1 extending in the longitudinal direction and a plurality of first pixel units 11, and the input terminal of the 7T1C pixel circuit in the first pixel unit is connected to the data line 1.
  • the under-screen camera area 10 includes a plurality of the data lines 1 extending in the second direction, that is, longitudinally, a plurality of second pixel units 12 arranged in the longitudinal direction, and a plurality of first pixel units 11 arranged in the longitudinal direction;
  • the second pixel unit 12 includes the 2T1C pixel circuit, each input terminal of the plurality of second pixel units 12 is connected in parallel to the scan line, and the other input terminal is connected to the output terminal of the step-down circuit;
  • the first pixel unit 11 includes a 7T1C pixel circuit, the input end of which is connected to the data line 1; wherein, the plurality of second pixel units 12 arranged in the longitudinal direction and the plurality of first pixels arranged in the longitudinal direction
  • the units 11 are arranged at intervals along the lateral direction.
  • the low positive voltage of 0V-3V and the operation of the 2T1C pixel circuit The voltage range is the same, so the output terminal of the step-down circuit can be directly connected to the 2T1C pixel circuit, so that the 2T1C pixel circuit can be mounted on the 10 field of the under-screen camera area, thereby improving the light transmission of the under-screen camera area 10 Rate.
  • the distribution density of the plurality of first pixel units 11 arranged in the longitudinal direction is smaller than the distribution density of the plurality of second pixel units 12 arranged in the longitudinal direction. More preferably, there are two first pixel units 11 arranged along the longitudinal direction, which are respectively arranged at positions adjacent to the edge of the display area 20. In this way, a light-transmitting gap can be formed between the two first pixel units 11 at the position of the data line 1 in an even-numbered row, and the light transmittance of the under-screen camera area 10 can be effectively improved.
  • the display panel 100 further includes a sensor (not shown) disposed opposite to the under-screen camera area 10, and the position of the sensor refers to the position of the camera 98 shown in FIG. 1.
  • the sensor includes one or a combination of a camera sensor, a flashlight, a light sensor, a breathing light sensor, a distance sensor, a fingerprint scanner sensor, a microphone sensor, or a transparent antenna sensor.
  • the area of the sensor is less than or equal to the area of the camera area 10 under the screen.
  • the advantage of the present invention is to provide a display panel 100, a display device and a manufacturing method thereof, by changing the circuit structure of the under-screen camera area 10 in the relative area of the sensor 7 to achieve the effect of improving the light transmittance.

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Abstract

一种像素电路及显示面板（100）。显示面板（100）包括像素电路；像素电路包括数据线、扫描线、若干层级2T1C电路、降压电路以及复位电路；数据线传递源数据信号（Source data）；扫描线传递扫描信号；若干层级2T1C电路的各输入端并连至扫描线；降压电路的输入端连接至数据线，其输出端连接至每一2T1C电路的另一输入端；复位电路连接至降压电路的输出端。显示面板（100）包括屏下摄像头区（10）以及围绕屏下摄像头区（10）设置的显示区（20），2T1C像素电路设置于屏下摄像头区（10）内，显示区（20）的像素单元包括7T1C像素电路。

Description

像素电路及显示面板 技术领域
本发明涉及显示领域，尤其涉及一种像素电路及显示面板。
背景技术
随着科技的不断发展，人们对显示器件的要求越来越高，显示屏技术发展也突飞猛进。现如今“全面屏”的设计成为时代的主流，各屏幕供应商都专注于研发屏占比较高的全面屏产品，提升显示屏屏占比成为一种产品发展的趋势。
目前市面上较多的提高屏占比方案通常将前置摄像头设计在显示屏外侧，通过异形切割设计使显示屏避让一定尺寸来容纳前置摄像头，不论切割设计如何变化，与全面屏概念相差甚远。近期兴起的发光型盲孔屏下摄像头(CUP)处理方案可使显示屏几乎趋近于全面屏效果。
如图1所示，为现有的一种屏下摄像头显示面板的结构示意图，屏下摄像头显示面板90包括从下至上依次层叠设置的柔性衬底层91、阵列基板92、发光层93、封装层94、偏光片95及盖板96。在阵列基板92和偏光片95对应位置设置通孔，形成盲孔97。将摄像头98置于屏幕下方并对应盲孔97设置，即盲孔97和摄像头98所在区域为屏下摄像头区域，通过面板设计与镜头设计的优化，使得镜头隐藏至屏幕的可显示区域下方也能完成拍摄。采用屏下摄像头方案时，为提高屏下摄像头区域的透光率，采用有机发光二极管(OLED)显示屏经典的7T1C电路时，为提高屏下摄像头区域的透光率，需要优化像素设计以降低屏下摄像头区域的像素密度实现局部透明。
在屏下摄像头区域上方搭载2T1C像素电路可以很好降低像素密度。因屏下摄像头区域面积较小，搭载2T1C像素电路对显示画面影响较小，但目前的2T1C像素电路工作电压不在驱动电路给定的正常数据电压范围内，故屏下摄像头区域搭载传统2T1C像素电路不可取。
屏下摄像头技术中，最影响成像的因素是屏幕的透光率，因此，提高屏下摄像头区域的透光率成为亟需解决的问题。
技术问题
本发明的目的在于，提供一种像素电路及显示面板，通过改变屏下摄像头区域的电路结构，实现提高透光率的效果.
技术解决方案
为了解决上述问题，本发明提供一种像素电路，包括数据线、扫描线、若干层级2T1C电路、降压电路以及复位电路；所述数据线用以传递源数据信号(Source data)；所述扫描线用以传递扫描信号；若干层级2T1C电路的各输入端并连至所述扫描线；所述降压电路的输入端连接至数据线，其输出端连接至每一2T1C电路的另一输入端；所述复位电路连接至所述降压电路的输入端。
进一步地，所述复位电路包括第一驱动晶体管(T1)，其源极输入一复位电压信号(VI)，其漏极连接至每一2T1C电路的另一输入端，其栅极输入一交流电压信号(VR)；当所述交流电压信号(VR)为低电平时，所述复位电压信号(VI)的电压写入所述2T1C像素电路，使其复位。
进一步地，所述降压电路包括第二驱动晶体管(T2)，其源极输入一源数据信号，其栅极和漏极连接至每一2T1C电路的另一输入端；当所述2T1C像素电路的扫描信号(Scan(n))为低电平时，所述源数据信号(Source data)的电压经所述第二驱动晶体管(T2)进行阈值电压(Vth)抓取后写入所述2T1C像素电路。
进一步地，所述交流电压信号(VR)的时序与多路复用器(Mux)信号的时序同步设置。
进一步地，所述像素电路还包括稳压电容(C)，其一端与所述电源正电压(VDD)电连接，其另一端与所述2T1C像素电路的输入端电连接，所述稳压电容(C)用于稳定输入所述2T1C像素电路的电压。
本发明还提供一种显示面板，包括上述像素电路。
进一步地，所述显示面板包括屏下摄像头区以及围绕所述屏下摄像头区设置的显示区，所述2T1C像素电路设置于所述屏下摄像头区内。
进一步地，所述屏下摄像头区包括沿纵向排布的若干第二像素单元以及沿纵向排布的若干第一像素单元；所述第二像素单元包括所述2T1C像素电路，若干所述第二像素单元的各输入端并连至所述扫描线，其另一输入端连接至所 述降压电路的输出端；所述第一像素单元包括7T1C像素电路，其输入端连接至所述数据线；其中，所述沿纵向排布的若干第二像素单元与所述沿纵向排布的若干第一像素单元在沿横向间隔排布。
进一步地，在所述屏下摄像头区内，所述沿纵向排布的若干第一像素单元的分布密度小于所述沿纵向排布的若干第二像素单元的分布密度。
进一步地，所述显示区包括沿纵向延伸的多条数据线以及若干第一像素单元，所述第一像素单元包括7T1C像素电路，其输入端连接至所述数据线。
有益效果
本发明的有益效果在于，提供一种像素电路及显示面板，通过改变屏下摄像头区的电路结构，实现提高透光率的效果。
附图说明
图1为现有的一种屏下摄像头显示面板的结构示意图；
图2为一2T1C像素电路的结构示意图；
图3为图2所示2T1C像素电路中的扫描信号Scan的时序图；
图4为图2所示2T1C像素电路的仿真结果图；
图5为一7T1C像素电路的结构示意图；
图6为图5所示7T1C像素电路的时序图；
图7为图5所示7T1C像素电路的仿真结果图；
图8为本发明实施例中一种像素电路的结构示意图；
图9为图8所示像素电路的仿真结果图；
图10为Mux_G信号可与2T1C像素电路的交流电压信号(VR)兼容示意图；
图11为所述显示面板的局部结构示意图。
图中部件标识如下：
1、数据线，2、源数据信号走线，10、屏下摄像头区，
11、第一像素单元，12、第二像素单元，20、显示区，
100、显示面板。
本发明的实施方式
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清 楚、完整地描述。显然，所描述的实施例仅仅是本申请一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域技术人员在没有作出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
在本发明中，相同或相对应的部件用相同的附图标记表示而与图号无关，在说明书全文中，当“第一”、“第二”等措辞可用于描述各种部件时，这些部件不必限于以上措辞。以上措辞仅用于将一个部件与另一部件区分开。
在本申请的描述中，需要说明的是，除非另有明确的规定和限定，术语“安装”、“相连”、“连接”应做广义理解，例如，可以是固定连接，也可以是可拆卸连接，或一体地连接；可以是机械连接，也可以是电连接或可以相互通讯；可以是直接相连，也可以通过中间媒介间接相连，可以是两个元件内部的连通或两个元件的相互作用关系。对于本领域的普通技术人员而言，可以根据具体情况理解上述术语在本申请中的具体含义。
图2为一2T1C像素电路的结构示意图，所述2T1C像素驱动电路包括第一薄膜晶体管T10、第二薄膜晶体管T20、存储电容Cst以及有机发光元件OLED。所述第一薄膜晶体管T10的栅极电性连接扫描信号Scan，扫描信号Scan的时序图如图3所示，源极电性连接数据信号Data，漏极与第二薄膜晶体管T20的栅极及存储电容Cst的一端电性连接；所述第二薄膜晶体管T20的源极电性连接电源正电压VDD，漏极电性连接有机发光二级管OLED的阳极；有机发光二级管OLED的阴极电性连接电源负电压VSS；存储电容Cst的一端电性连接第一薄膜晶体管T10的漏极，另一端电性连接第二薄膜晶体管T20的源极。在显示时，扫描信号Scan控制第一薄膜晶体管T10打开，数据信号Data经过第一薄膜晶体管T10进入到第二薄膜晶体管T20的栅极及存储电容Cst，然后第一薄膜晶体管T10闭合，由于存储电容Cst的存储作用，第二薄膜晶体管T20的栅极电压仍可继续保持数据信号电压，使得第二薄膜晶体管T20处于导通状态，驱动电流通过第二薄膜晶体管T20进入有机发光二级管OLED，驱动有机发光二级管OLED发光。
2T1C像素电路没有阈值电压Vth抓取，保持薄膜晶体管和存储电容的尺寸大小与经典7T1C电路一致，当第一晶体管T10写入的Data电压为3.0V时，根据图4仿真结果可知，第二薄膜晶体管T20的栅极电压Q点会因与第一薄膜 晶体管T10的漏极连接作用达到3.4V，故没有7T1C电路的Vth抓取。当写入VDD电压为4.6V，VSS为-4.0V时，对于p型TFT，此时栅极电压Vgs＝3.4-4.6＝-1.2V，大于第二薄膜晶体管T20的阈值电压Vth(约-2.5V)，第二薄膜晶体管T20处于未打开状态，理论上流过有机发光二极管的电流几乎为0，与图4仿真结果I OLED＝3.5pA相近。
如图5所示，为一7T1C像素电路的结构示意图，所述7T1C像素电路包括：第一晶体管M1、第二晶体管M2、第三晶体管M3、第四晶体管M4、第五晶体管M5、第六晶体管M6、第七晶体管M7、存储电容Cst以及有机发光元件OLED。
所述第一晶体管M1的栅极与所述存储电容Cst的第一端连接，所述第一晶体管M1的第一电极与所述第二晶体管M2的第一电极连接，所述第一晶体管M1的第二电极与所述第三晶体管M3的第一电极连接。所述第二晶体管M2的栅极与第二扫描信号端Scan(n)连接，所述第二晶体管M2的第二电极与数据信号端Vdata连接。所述第三晶体管M3的栅极与所述第二扫描信号端Scan(n)连接，所述第三晶体管M3的第二电极与所述存储电容Cst的第一端连接。所述存储电容Cst的第二端与第一电压信号端VDD连接。
所述第四晶体管M4的栅极与第一扫描信号端Scan(n-1)连接，所述第四晶体管M4的第一电极与所述存储电容Cst的第一端连接，所述第四晶体管M4的第二电极与初始化信号端Vi连接。所述第五晶体管M5的栅极与控制信号端EM连接，所述第五晶体管M5的第一电极与所述第一电压信号端VDD连接，所述第五晶体管M5的第二电极与所述第一晶体管M1的第一电极连接。所述第六晶体管M6的栅极与所述控制信号端EM连接，所述第六晶体管M6的第一电极与所述第一晶体管M1的第二电极连接，所述第六晶体管M6的第二电极与所述有机发光元件OLED的阳极连接。所述有机发光元件OLED的阴极与第二电压信号端VSS连接。
所述第七晶体管M7的栅极与所述第二扫描信号端Scan(n)连接，所述第七晶体管M7的第一电极与所述初始化信号端Vi连接，所述第七晶体管M7的第二电极与所述有机发光元件OLED的阳极连接。
其中，所述第三晶体管M3包含相串连的两个子晶体管，第一子晶体管M31的栅极与所述第二扫描信号端Scan(n)连接，所述第一子晶体管M31的第一电 极与第二子晶体管M32的第二电极连接，第一子晶体管M31的第二电极与所述存储电容Cst的第一端连接；所述第二子晶体管M32的栅极与所述第二扫描信号端Scan(n)连接，所述第二子晶体管M32的第一电极与所述第一晶体管M1的第二电极相连。
其中，所述第四晶体管M4包含相串连的两个子晶体管，第三子晶体管M41的栅极与所述第一扫描信号端Scan(n-1)连接，所述第三子晶体管M41的第一蒂娜及与所述存储电容Cst的第一端连接，所述第三子晶体管M41的第二电极与第四子晶体管M42的第一电极连接；所述第四子晶体管M42的栅极与所述第一扫描信号端Scan(n-1)连接，所述第四子晶体管M42的第二电极与所述初始化信号端Vi连接。
所述存储电容Cst的第一端、所述第一晶体管M1的栅极、所述第三晶体管M3的第二电极以及所述第四晶体管M4的第一电极相互电性连接。
7T1C像素电路的时序图如图6所示，在初始化阶段，所述第一扫描信号端Scan(n-1)提供低电平信号，所述第四晶体管M4导通，所述初始化信号Vi通过所述第四晶体管M4对所述存储电容Cst进行初始化。在数据写入阶段，第二扫描信号端Scan(n)提供低电平信号，所述第二晶体管M2与第三晶体管M3导通，所述数据信号端Data提供的信号对所述存储电容Cst的第一端进行充电，至所述第一晶体管M1截止。在7T1C像素电路中保持常规的薄膜晶体管尺寸和存储电容大小。
仿真结果如图7所示，当写入的Data电压为3.0V时，所述第一晶体管M1的栅极电压因其Vth提取达到1.4V，在7T1C像素电路中写入VDD电压为4.6V，VSS为-4.0V，对于p型TFT，此时栅极电压Vgs＝1.4-4.6＝-3.2V，小于所述第一晶体管M1的阈值电压Vth(约-2.5V)，所述第一晶体管M1处于打开状态，仿真结果可知，通过OLED的电流为18nA。
在相同的Data写入电压下，在2T1C像素电路流过OLED的电流与7T1C像素电路流过OLED的电流相差至少3个数量级，即对于2T1C像素电路，要达到与7T1C像素电路相同电流值，需写入更小的Data电压。一般在7T1C像素电路工作的Data值范围约为3.0V-6.0V；相对应2T1C像素电路工作的Data值范围约为0.5V-3.5V，2T1C像素电路工作电压不在驱动电路给定的正常数据 电压范围内，故屏下摄像头区域搭载2T1C像素电路不可取。
针对上述技术问题，申请人经过研究，提供一种像素电路及显示面板，能够实现在屏下摄像头区域搭载2T1C像素电路，提高透光率。
请参阅图8、图9所示，本发明实施例提供一种像素电路，包括数据线、扫描线、若干层级2T1C电路、降压电路以及复位电路；所述数据线用以传递源数据信号(Source data)；所述扫描线用以传递扫描信号；若干层级2T1C电路的各输入端并连至所述扫描线；所述降压电路的输入端连接至数据线，其输出端连接至每一2T1C电路的另一输入端；所述复位电路连接至所述降压电路的输入端。
进一步地，所述复位电路包括第一驱动晶体管(T1)，其源极输入一复位电压信号(VI)，其漏极连接至每一2T1C电路的另一输入端，其栅极输入一交流电压信号(VR)；当所述交流电压信号(VR)为低电平时，所述复位电压信号(VI)的电压写入所述2T1C像素电路，使其复位。
进一步地，所述降压电路包括第二驱动晶体管(T2)，其源极输入一源数据信号，其栅极和漏极连接至每一2T1C电路的另一输入端；即所述第二驱动晶体管(T2)的栅极和漏极相互电连接并与所述第一驱动晶体管(T1)的漏极电连接；所有所述2T1C像素电路的输入端均与所述第一驱动晶体管(T1)的漏极、第二驱动晶体管(T2)的漏极电连接；当所述交流电压信号(VR)为低电平时，所述复位电压信号(VI)的电压写入所述2T1C像素电路，使其复位；当所述交流电压信号(VR)为高电平、所述2T1C像素电路的扫描信号(Scan(n))为低电平时，所述源数据信号(Source data)的电压经所述第二驱动晶体管(T2)进行阈值电压(Vth)抓取后写入所述2T1C像素电路。
其中所述2T1C像素电路的结构示意图参考图2所示，所述像素电路的仿真结果参考图9所示，在图9中的Sn、Sn+1、Sn+2表示所述2T1C像素电路的扫描信号Scan的逐次输入信号。
本实施例中，所述复位电压信号(VI)为一负电压，优选为-3V。
本实施例中，所述源数据信号(Source data)的电压为一高位正电压，经所述第二驱动晶体管(T2)进行阈值电压(Vth)抓取后降为一低位正电压，写入所述2T1C像素电路。
本实施例中，所述第二驱动晶体管(T2)的阈值电压(Vth)的电压值为所述2T1C像素电路的工作电压值与所述源数据信号(Source data)的电压值的差值。
具体的，所述源数据信号(Source data)的电压为一高位正电压2.5V-5.5V，预设所述第二驱动晶体管(T2)的阈值电压(Vth)为-2.5V，所述源数据信号(Source data)经阈值电压(Vth)抓取后降为一低位正电压0V-3V，该低位正电压0V-3V与所述2T1C像素电路的工作电压范围相同，因此可直接写入所述2T1C像素电路，从而能够实现在屏下摄像头区域搭载2T1C像素电路，提高了透光率。
像素电路的电流公式为：
Figure PCTCN2020084823-appb-000001
其中，u n代表迁移率，Cox代表栅氧化层电容，W/L代表薄膜晶体管沟道的宽长比，Vgs代表栅极电压，Vth代表阈值电压。
并且经像素电路的电流公式计算验证可知，流过所述2T1C像素电路的有机发光元件OLED的电流与流过7T1C像素电路的有机发光元件OLED的电流一致，则本实施例改进后的所述2T1C像素电路的工作电压范围与7T1C像素电路相同。
本实施例中，所述交流电压信号(VR)的时序与多路复用器(Mux)信号的时序同步设置。可理解的是，所述交流电压信号(VR)可由多路复用器(Mux)提供信号。具体如图10所示，Mux_G信号可与上述2T1C像素电路的所述交流电压信号(VR)兼容，不需集成电路(IC)额外提供信号。
本实施例中，所述像素电路还包括稳压电容(C)，其一端与所述电源正电压(VDD)电连接，其另一端与所述2T1C像素电路的输入端电连接，所述稳压电容(C)用于稳定输入所述2T1C像素电路的电压。其中所述电源正电压(VDD)为一固定电压，优选为4.6V。
图11为所述显示面板的局部结构示意图。如图11所示，本发明还提供一种显示面板100，包括上述像素电路。
所述显示面板100包括屏下摄像头(CUP)区10以及围绕所述屏下摄像头 区10设置的显示区20，所述2T1C像素电路设置于所述屏下摄像头区10内。
本实施例中，所述显示区20包括沿第一方向延伸的多条扫描线(未图示)、沿第二方向延伸的多条数据线1以及由相邻两扫描线与相邻两数据线1定义的若干第一像素单元11，所述第一像素单元11包括7T1C像素电路；所述第二方向与所述第一方向不同，本实施例优选所述第一方向为横向，所述第二方向为纵向，故所述显示区20包括沿纵向延伸的多条数据线1以及若干第一像素单元11，所述第一像素单元中的7T1C像素电路的输入端连接至所述数据线1。
所述屏下摄像头区10包括沿所述第二方向即纵向延伸的多条所述数据线1、沿纵向排布的若干第二像素单元12以及沿纵向排布的若干第一像素单元11；所述第二像素单元12包括所述2T1C像素电路，若干所述第二像素单元12的各输入端并连至所述扫描线，其另一输入端连接至所述降压电路的输出端；所述第一像素单元11包括7T1C像素电路，其输入端连接至所述数据线1；其中，所述沿纵向排布的若干第二像素单元12与所述沿纵向排布的若干第一像素单元11在沿横向间隔排布。
由上文所述2T1C像素电路的原理可知，在所述源数据信号(Source data)的电压为一高位正电压2.5V-5.5V，预设所述第二驱动晶体管(T2)的阈值电压(Vth)为-2.5V，所述源数据信号(Source data)经阈值电压(Vth)抓取后降为一低位正电压0V-3V，该低位正电压0V-3V与所述2T1C像素电路的工作电压范围相同，因此所述降压电路的输出端可直接连接所述2T1C像素电路，从而能够实现在屏下摄像头区10域搭载2T1C像素电路，从而提高了所述屏下摄像头区10的透光率。
优选地，在所述屏下摄像头区10内，所述沿纵向排布的若干第一像素单元11的分布密度小于所述沿纵向排布的若干第二像素单元12的分布密度。更优选地，沿所述纵向排布的所述第一像素单元11为两个，分别设于临近所述显示区20的边缘位置。这样可以在偶数行所述数据线1位置的两个所述第一像素单元11之间形成透光间隙，可有效提高所述屏下摄像头区10的透光率。
本实施例中，所述显示面板100还包括与所述屏下摄像头区10相对设置的传感器(未图示)，所述传感器的位置参考图1所示摄像头98的位置。所述传感器包括摄像头传感器、闪光灯、光线传感器、呼吸灯传感器、距离传感器、 指纹扫描仪传感器、麦克风传感器或透明天线传感器中的一种或其组合。优选所述传感器的面积小于等于所述屏下摄像头区10的面积。
本发明的优点在于，提供一种显示面板100、显示装置及其制造方法，通过改变在传感器7相对区域的屏下摄像头区10的电路结构，实现提高透光率的效果。
以上所述仅是本发明的优选实施方式，应当指出，对于本技术领域的普通技术人员，在不脱离本发明原理的前提下，还可以做出若干改进和润饰，这些改进和润饰也应视为本发明的保护范围。

Claims (10)

  1. 一种像素电路，其包括：
    数据线，用以传递源数据信号；
    扫描线，用以传递扫描信号；
    若干层级2T1C电路，各输入端并连至所述扫描线；
    降压电路，其输入端连接至数据线，其输出端连接至每一2T1C电路的另一输入端；以及
    复位电路，连接至所述降压电路的输入端。
  2. 根据权利要求1所述的像素电路，其中，所述复位电路包括：
    第一驱动晶体管，其源极输入一复位电压信号，其漏极连接至每一2T1C电路的另一输入端，其栅极输入一交流电压信号；
    当所述交流电压信号为低电平时，所述复位电压信号的电压写入所述2T1C像素电路，使其复位。
  3. 根据权利要求1所述的像素电路，其中，所述降压电路包括：
    第二驱动晶体管，其源极输入一源数据信号，其栅极和漏极连接至每一2T1C电路的另一输入端；
    当所述2T1C像素电路的扫描信号为低电平时，所述源数据信号的电压经所述第二驱动晶体管进行阈值电压抓取后写入所述2T1C像素电路。
  4. 根据权利要求1所述的像素电路，其中，所述交流电压信号的时序与多路复用器信号的时序同步设置。
  5. 根据权利要求1所述的像素电路，其中，还包括：
    稳压电容，其一端与所述电源正电压电连接，其另一端与所述2T1C像素电路的输入端电连接，所述稳压电容用于稳定输入所述2T1C像素电路的电压。
  6. 一种显示面板，其包括权利要求1所述的像素电路。
  7. 根据权利要求6所述的显示面板，其中，所述显示面板包括屏下摄像头区以及围绕所述屏下摄像头区设置的显示区，所述2T1C像素电路设置于所述屏下摄像头区内。
  8. 根据权利要求7所述的显示面板，其中，所述屏下摄像头区包括：
    沿纵向排布的若干第二像素单元，所述第二像素单元包括所述2T1C像素 电路，若干所述第二像素单元的各输入端并连至所述扫描线，其另一输入端连接至所述降压电路的输出端；以及
    沿纵向排布的若干第一像素单元，所述第一像素单元包括7T1C像素电路，其输入端连接至所述数据线；
    其中，所述沿纵向排布的若干第二像素单元与所述沿纵向排布的若干第一像素单元在沿横向间隔排布。
  9. 根据权利要求8所述的显示面板，其中，在所述屏下摄像头区内，所述沿纵向排布的若干第一像素单元的分布密度小于所述沿纵向排布的若干第二像素单元的分布密度。
  10. 根据权利要求7所述的显示面板，其中，所述显示区包括沿纵向延伸的多条数据线以及若干第一像素单元，所述第一像素单元包括7T1C像素电路，其输入端连接至所述数据线。
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