WO2022217642A1 - 一种背光驱动方法及显示面板 - Google Patents

一种背光驱动方法及显示面板 Download PDF

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Publication number
WO2022217642A1
WO2022217642A1 PCT/CN2021/089595 CN2021089595W WO2022217642A1 WO 2022217642 A1 WO2022217642 A1 WO 2022217642A1 CN 2021089595 W CN2021089595 W CN 2021089595W WO 2022217642 A1 WO2022217642 A1 WO 2022217642A1
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WIPO (PCT)
Prior art keywords
modulated
scan signal
pulse
level
pulse period
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PCT/CN2021/089595
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English (en)
French (fr)
Inventor
胡道兵
万广苗
王航
王旭
胡聪
徐洪远
孙宇成
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Tcl华星光电技术有限公司
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Priority to US17/289,291 priority Critical patent/US20240127761A1/en
Publication of WO2022217642A1 publication Critical patent/WO2022217642A1/zh

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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
    • G09G3/34—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 by control of light from an independent source
    • G09G3/3406—Control of illumination source
    • 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
    • G09G2300/0809—Several active elements per pixel in active matrix panels
    • G09G2300/0842—Several active elements per pixel in active matrix panels forming a memory circuit, e.g. a dynamic memory with one capacitor
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G2310/00—Command of the display device
    • G09G2310/08—Details of timing specific for flat panels, other than clock recovery
    • 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
    • G09G2320/06—Adjustment of display parameters
    • G09G2320/0626—Adjustment of display parameters for control of overall brightness
    • G09G2320/064—Adjustment of display parameters for control of overall brightness by time modulation of the brightness of the illumination source

Definitions

  • the present application relates to the field of display technology, and in particular, to a backlight driving method and a display panel.
  • Mini light-emitting diode (Mini LED) backplane driver currently includes Active Matrix (AM) driver and Passive Matrix (Passive) driver.
  • Matrix, PM) driver Since the Thin Film Transistor (TFT) in the Mini-LED AM driver can play a switching role, a lot of driver integrated circuits (Integrated Circuits) can be saved compared to PM. Circuit, IC), so AM drive costs less than PM drive.
  • AM-driven backplane technologies currently use amorphous silicon ( ⁇ -Si), indium gallium zinc oxide (IGZO) and low temperature polysilicon (LTPS). The stability of TFT greatly affects the brightness and taste of Mini LED.
  • the inventor of the present application found that the stability of the TFT is strongly related to the scan signal high level (Scan high) time, and the high level time is too long will increase the threshold of the TFT Voltage drift (Vth shift), resulting in decreased stability.
  • the present application provides a backlight driving method and a display panel, which can enhance the stability of thin film transistors.
  • the present application provides a backlight driving method, including:
  • the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal, so as to increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the modulated scan signal is less than that of the scan signal to be modulated The number of high-level pulses;
  • the modulated scan signal is output to the backlight driving circuit.
  • the scan signal to be modulated in one frame includes multiple initial pulse periods, and the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal,
  • the pulse width modulation signal to increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the scan signal after modulation is less than the number of high-level pulses of the scan signal to be modulated, including:
  • the signal includes a plurality of said first pulse periods.
  • the scan signal to be modulated in one frame includes 127 initial pulse periods, and the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal,
  • the pulse width modulation signal To increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the scan signal after modulation is less than the number of high-level pulses of the scan signal to be modulated, including:
  • the scan signal to be modulated in one frame is modulated to include one initial pulse period and p first pulse periods, and the time of the first pulse period is the time of two initial pulse periods; wherein, The value of p is 63.
  • the scan signal to be modulated in one frame includes multiple initial pulse periods, and the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal,
  • the pulse width modulation signal to increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the scan signal after modulation is less than the number of high-level pulses of the scan signal to be modulated, including:
  • the modulated scan signal includes a plurality of the first pulse periods A pulse period and a plurality of second pulse periods, wherein the time of the initial pulse period is less than the time of the first pulse period, and the time of the first pulse period is less than the time of the second pulse period.
  • the time of the first pulse period is the time of two initial pulse periods
  • the time of the second pulse period is the time of four initial pulse periods.
  • the scan signal to be modulated in one frame includes multiple initial pulse periods, and the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal,
  • the pulse width modulation signal to increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the scan signal after modulation is less than the number of high-level pulses of the scan signal to be modulated, including:
  • the modulated scanning signal in one frame includes one initial pulse period, n first pulse periods and m second pulse periods, the time of the first pulse period is the time of two initial pulse periods, and the time of the second pulse period is four of the initial pulse periods Time; where the sum of n and m is 32, and m and n are positive integers greater than 1.
  • the scan signal to be modulated in one frame includes 127 initial pulse periods, and the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal,
  • the pulse width modulation signal To increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the scan signal after modulation is less than the number of high-level pulses of the scan signal to be modulated, including:
  • the scan signal to be modulated in one frame is modulated to include one initial pulse period, one first pulse period and 31 second pulse periods.
  • the modulated scan signal includes one initial pulse period, one first pulse period, and 31 second pulse periods that are set in sequence.
  • the backlight driving method is applied in a backlight driving circuit, and the backlight driving circuit includes a first transistor, a second transistor, a storage capacitor, and a light-emitting device;
  • the source of the first transistor is connected to the cathode of the light-emitting device, the drain of the first transistor is grounded, and the gate of the first transistor is electrically connected to the first node;
  • the source of the second transistor is connected to the data signal, the drain of the second transistor is electrically connected to the first node, and the gate of the second transistor is connected to the modulated scan signal;
  • the first end of the storage capacitor is electrically connected to the first node, and the second end of the storage capacitor is grounded;
  • the anode of the light-emitting device is connected to the power signal.
  • the modulated scan signal when the modulated scan signal is at a high level, the data signal is at a high level, and a high-level pulse width of the data signal is greater than that after the modulation.
  • the present application provides a display panel, the display panel includes a backlight module, a backlight drive circuit is arranged on the backlight module, and the backlight drive circuit is driven by a backlight drive method, and the backlight drive method includes :
  • the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal, so as to increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the modulated scan signal is less than that of the scan signal to be modulated The number of high-level pulses;
  • the modulated scan signal is output to the backlight driving circuit.
  • the scan signal to be modulated in one frame includes multiple initial pulse periods, and the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal,
  • the pulse width modulation signal to increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the scan signal after modulation is less than the number of high-level pulses of the scan signal to be modulated, including:
  • the signal includes a plurality of said first pulse periods.
  • the scan signal to be modulated in one frame includes 127 initial pulse periods, and the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal,
  • the pulse width modulation signal To increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the scan signal after modulation is less than the number of high-level pulses of the scan signal to be modulated, including:
  • the scan signal to be modulated in one frame is modulated to include one initial pulse period and p first pulse periods, and the time of the first pulse period is the time of two initial pulse periods; wherein, The value of p is 63.
  • the scan signal to be modulated in one frame includes multiple initial pulse periods, and the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal,
  • the pulse width modulation signal to increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the scan signal after modulation is less than the number of high-level pulses of the scan signal to be modulated, including:
  • the modulated scan signal includes a plurality of the first pulse periods A pulse period and a plurality of second pulse periods, wherein the time of the initial pulse period is less than the time of the first pulse period, and the time of the first pulse period is less than the time of the second pulse period.
  • the time of the first pulse period is the time of two initial pulse periods
  • the time of the second pulse period is the time of four initial pulse periods.
  • the scan signal to be modulated in one frame includes multiple initial pulse periods, and the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal,
  • the pulse width modulation signal to increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the scan signal after modulation is less than the number of high-level pulses of the scan signal to be modulated, including:
  • the modulated scanning signal in one frame includes an initial pulse period, n first pulse periods and m second pulse periods, the time of the first pulse period is the time of two initial pulse periods, and the time of the second pulse period is four of the initial pulse periods Time; where the sum of n and m is 32, and m and n are positive integers greater than 1.
  • the scan signal to be modulated in one frame includes 127 initial pulse periods, and the low-level pulse width of the scan signal to be modulated is modulated according to the pulse width modulation signal,
  • the pulse width modulation signal To increase the pulse period of the scan signal to be modulated, so that the number of high-level pulses of the scan signal after modulation is less than the number of high-level pulses of the scan signal to be modulated, including:
  • the scan signal to be modulated in one frame is modulated to include one initial pulse period, one first pulse period and 31 second pulse periods.
  • the modulated scan signal includes one initial pulse period, one first pulse period, and 31 second pulse periods that are set in sequence.
  • the backlight driving method is applied in a backlight driving circuit, and the backlight driving circuit includes a first transistor, a second transistor, a storage capacitor, and a light-emitting device;
  • the source of the first transistor is connected to the cathode of the light-emitting device, the drain of the first transistor is grounded, and the gate of the first transistor is electrically connected to the first node;
  • the source of the second transistor is connected to the data signal, the drain of the second transistor is electrically connected to the first node, and the gate of the second transistor is connected to the modulated scan signal;
  • the first end of the storage capacitor is electrically connected to the first node, and the second end of the storage capacitor is grounded;
  • the anode of the light-emitting device is connected to the power signal.
  • the modulated scan signal when the modulated scan signal is at a high level, the data signal is at a high level, and a high-level pulse width of the data signal is greater than that after the modulation.
  • the present application discloses a backlight driving method and a display panel.
  • the backlight driving method provided by the present application uses the pulse width modulation technology to modulate the low-level pulse width of the scan signal.
  • the high-level pulse time is reduced.
  • the time for the TFT to be subjected to a high-level voltage is also reduced, thereby improving the stability of the TFT and improving the problem of the threshold voltage drift of the TFT.
  • FIG. 1 is a schematic flowchart of a backlight driving method provided by the present application.
  • FIG. 2 is a schematic diagram of a scanning signal provided by the present application.
  • Fig. 3 is the first schematic diagram before and after the modulation of the scanning signal provided by the present application.
  • FIG. 5 is a schematic circuit diagram of a backlight driving circuit in the backlight driving method provided by the present application.
  • FIG. 6 is a timing diagram of a backlight driving circuit in the backlight driving method provided by the present application.
  • FIG. 7 is a schematic structural diagram of a display panel provided by the present application.
  • the present application provides a backlight driving method and a display panel. Each of them will be described in detail below. It should be noted that the description order of the following embodiments is not intended to limit the preferred order of the embodiments.
  • FIG. 1 is a schematic flowchart of a backlight driving method provided by the present application.
  • a backlight driving method provided by this application specifically includes the following steps:
  • Pulse width modulation refers to the equivalent of obtaining the required waveform by modulating the width of a series of pulses.
  • PWM technology is a very effective technology that uses the digital signal of the microprocessor to control the analog circuit.
  • the PWM control technology is simple in structure, easy to implement, and relatively mature in technology, and has been widely used.
  • the pulse width modulation signal of the present application is obtained through the PWM technology, and details are not described here.
  • FIG. 2 is a schematic diagram of a scan signal provided by the present application.
  • a display panel there are multiple rows of backlight driving units, and each row of backlight driving units corresponds to a row of backlight driving circuits.
  • the backlight driving circuits of each row are controlled by scanning signals respectively, so as to scan the backlight driving circuits row by row.
  • FIG. 2 taking the display panel having n rows of backlight driving circuits as an example, there are respectively n rows of scan signals, which are indicated as Scan1 , Scan2 , ... Scan(n-1) and Scan(n).
  • one high-level pulse width plus the adjacent low-level pulse width is one pulse period T. That is, the pulse period T represents the time from a high-level pulse to the next high-level pulse.
  • the low-level pulse width D may also be referred to as a pulse interval.
  • the time from the scanning signal Scan1 of the first line to the scanning signal Scan(n) of the nth line is turned on line by line, plus the vertical scanning start of the next scanning after n lines are scanned.
  • the vertical blanking interval is called a minimum subfield time t.
  • the minimum subfield time t is determined according to the gray scale and resolution of the display panel. For example, for a display panel with 128 grayscales and a resolution of 240Hz, one frame time is 4.17 milliseconds (ms), and there are 128 grayscales in one frame, so the minimum subfield time t is 32.6 microseconds ( ⁇ s).
  • ms milliseconds
  • ⁇ s microseconds
  • FIG. 3 is a first schematic diagram of the scanning signal before and after modulation provided by the present application.
  • FIG. 3 takes the scanning signal of a certain row in FIG. 2 as an example, and compresses the pulse period of the scanning signal in one frame for illustration.
  • the low-level pulse width of the scan signal ScanO to be modulated is modulated according to the pulse width modulation signal, so as to increase the pulse period of the scan signal ScanO to be modulated, so that the number of high-level pulses of the scan signal ScanO to be modulated is reduced, Specifically include the following steps:
  • the width of the low-level pulse is increased, and at least one initial pulse period P0 is modulated into the first pulse period P1.
  • the time of the first pulse period P1 is the time of at least two initial pulse periods P0, so that the number of high-level pulses of the modulated scan signal is less than the number of high-level pulses of the scan signal to be modulated.
  • the to-be-modulated scan signal ScanO includes a plurality of initial pulse periods P0
  • the modulated scan signal ScanM includes a plurality of first pulse periods P1.
  • the present application does not limit the number of the initial pulse period P0 and the first pulse period P1 in the modulated scan signal ScanM, and it is only necessary to make the sum of the pulse periods occupy one frame after modulation.
  • the modulated scan signal ScanM may include an initial pulse period P0 and a plurality of first pulse periods P1.
  • the modulated scan signal ScanM may include a plurality of initial pulse periods P0 and a first pulse period P1.
  • the time of the first pulse period P1 may be the time of two initial pulse periods P0, the time of three initial pulse periods P0, the time of four initial pulse periods P0, the time of five initial pulse periods P0, the time of six initial pulse periods Time for initial pulse period P0, time for seven initial pulse periods P0, time for eight initial pulse periods P0, time for ten initial pulse periods P0, time for sixteen initial pulse periods P0, or thirty-two initial pulse periods Period P0 time.
  • the scan signal ScanO to be modulated in one frame includes 127 initial pulse periods P0, and the post-modulation scan signal ScanM in one frame includes an initial pulse period P0 and p first pulse periods P1.
  • the time of the first pulse period P1 is the time of two initial pulse periods P0. Among them, the value of p is 63.
  • a display panel with 127 grayscales has 127 minimum subfield times t in one frame time.
  • the scan signal ScanO to be modulated for one row has 127 initial pulse periods P0.
  • p is 127
  • the time of the first pulse period P1 is the time of two initial pulse periods P0. Therefore, 126 initial pulse periods P0 in one frame are modulated into 63 first pulse periods P1.
  • the modulated scan signal ScanM includes an initial pulse period P0 and 63 first pulse periods P1.
  • 127 high-level pulses in one frame of the scan signal ScanO to be modulated are modulated into 64 high-level pulses of the modulated scan signal ScanM. That is, the time that the TFT is subjected to a high-level voltage is reduced by half, thereby improving the drift of the threshold voltage.
  • the arrangement sequence of the initial pulse period P0 and the first pulse period P1 is only for illustration, and is not intended to limit the present application.
  • FIG. 4 is a second schematic diagram of the scanning signal before and after modulation provided by the present application. Similarly, FIG. 4 takes the scanning signal of a certain row in FIG. 2 as an example, and compresses the pulse period of the scanning signal in one frame for illustration.
  • the low-level pulse width of the scan signal ScanO to be modulated is modulated according to the pulse width modulation signal, so as to increase the pulse period of the scan signal ScanO to be modulated, so that the number of high-level pulses of the modulated scan signal ScanM is less than the number of high-level pulses of the scan signal ScanM to be modulated
  • the number of high-level pulses of the modulation scan signal ScanO including:
  • the scan signal ScanO to be modulated includes a plurality of initial pulse periods P0
  • the modulated scan signal ScanM includes a plurality of first pulse periods P1 and a plurality of second pulse periods P2, the time of the initial pulse period P0 is less than the time of the first pulse period P1, and the time of the first pulse period P1 is less than the time of the second pulse period P2.
  • the present application does not limit the number of the initial pulse period P0, the first pulse period P1 and the second pulse period P2 in the modulated scan signal ScanM, and it is only necessary to make the sum of the pulse periods occupy one frame after modulation.
  • the modulated scan signal ScanM may include an initial pulse period P0, a first pulse period P1 and a plurality of second pulse periods P2.
  • the modulated scan signal ScanM may include an initial pulse period P0, a plurality of first pulse periods P1 and a second pulse period P2.
  • the time of the first pulse period P1 may be the time of two initial pulse periods P0, the time of three initial pulse periods P0, the time of four initial pulse periods P0, the time of five initial pulse periods P0, the time of six initial pulse periods The time of the initial pulse period P0, the time of seven initial pulse periods P0, the time of eight initial pulse periods P0, the time of ten initial pulse periods P0, or the time of sixteen initial pulse periods P0.
  • the time of the second pulse period P2 may be the time of two initial pulse periods P0, the time of three initial pulse periods P0, the time of four initial pulse periods P0, the time of five initial pulse periods P0, the time of six initial pulse periods Time for initial pulse period P0, time for seven initial pulse periods P0, time for eight initial pulse periods P0, time for ten initial pulse periods P0, time for sixteen initial pulse periods P0, or thirty-two initial pulse periods Period P0 time.
  • the time of the first pulse period P1 is the time of two initial pulse periods P0
  • the time of the second pulse period P2 is the time of four initial pulse periods P0.
  • a plurality of initial pulse periods P0 are modulated into n first pulse periods P1 and m second pulse periods P2.
  • the modulated scan signal ScanM includes an initial pulse period P0, n first pulse periods P1, and m second pulse periods P2.
  • the time of the first pulse period P1 is the time of two initial pulse periods P0
  • the time of the second pulse period P2 is the time of four initial pulse periods P0.
  • the sum of n and m is 32, and m and n are positive integers greater than 1.
  • the value of n is 1 and the value of m is 31.
  • the following description takes a 127 grayscale display panel as an example. A display panel with 127 gray scales has 127 minimum subfield times t in one frame time. Then, the scan signal ScanO to be modulated for one row has 127 initial pulse periods P0. The value of n is 1 and the value of m is 31. Therefore, 126 initial pulse periods P0 in one frame are modulated into 1 first pulse period P1 and 31 second pulse periods P2. Then the modulated scan signal ScanM includes an initial pulse period P0, a first pulse period P1 and 31 second pulse periods P2.
  • the arrangement sequence of the initial pulse period P0 , the first pulse period P1 and the second pulse period P2 is only for illustration and is not intended to limit the present application.
  • the display panel is a 127 grayscale display panel.
  • a display panel with 127 gray scales has 127 minimum subfield times t in one frame time.
  • the scan signal ScanO to be modulated for one row has 127 initial pulse periods P0.
  • the to-be-modulated scan signal ScanO is modulated according to the pulse width modulation signal, and the modulated scan signal ScanM has an initial pulse period P0, a first pulse period P1, a second pulse period P2, a third pulse period P3, and a fourth pulse period Period P4 and three fifth pulse periods P5.
  • the time of the first pulse period P1 is the time of two initial pulse periods P0.
  • the time of the second pulse period P2 is the time of the four initial pulse periods P0.
  • the time of the third pulse period P3 is the time of the eight initial pulse periods P0.
  • the time of the fourth pulse period P4 is the time of sixteen initial pulse periods P0.
  • the time of the fifth pulse period P5 is the time of thirty-two initial pulse periods P0.
  • 127 high-level pulses in the scan signal ScanO to be modulated are modulated into 8 high-level pulses of the modulated scan signal ScanM.
  • the number of high-level pulses is greatly reduced, and the time of high-level pulses is greatly shortened.
  • the high voltage action time of the scanning signal on the TFT is greatly reduced, the stability of the TFT is improved, and the problem of threshold voltage drift is well improved.
  • the modulated pulse period range is controlled between 2 and 32 initial pulse periods P0.
  • the backlight driving circuit 10 includes a first transistor T1, a second transistor T2, a storage capacitor C and a light emitting device LED.
  • the source of the first transistor T1 is connected to the cathode of the light emitting device LED, the drain of the first transistor T1 is grounded, and the gate of the first transistor T1 is electrically connected to the first node N.
  • the source of the second transistor T2 is connected to the data signal Data, the drain of the second transistor T2 is electrically connected to the first node N, and the gate of the second transistor T2 is connected to the modulated scan signal ScanM.
  • the first end of the storage capacitor C is electrically connected to the first node N, and the second end of the storage capacitor C is grounded.
  • the anode of the light emitting device LED is connected to the power supply signal VDD.
  • the modulated scan signal ScanM includes an initial pulse period P0 , a first pulse period P1 and 31 second pulse periods P2 which are sequentially set. Using this sequence, the potential of the first node N can be raised during the first initial pulse period P0, and the storage capacitor C can be charged, so as to ensure the light-emitting effect of the light-emitting device LED. Extending the low-level pulse width after that can reduce the influence of the low-level pulse width on the subsequent lighting of the light-emitting device LED.
  • FIG. 6 is a timing diagram of a backlight driving circuit in the backlight driving method provided by the present application.
  • the modulated scan signal ScanM is at a high level
  • the data signal Data is at a high level
  • a high-level pulse width of the data signal Data is greater than a high-level pulse width corresponding to the modulated scan signal ScanM.
  • the modulated scan signal ScanM reduces the number of high-level pulses and increases the width of low-level pulses.
  • the high-level pulse width of the data signal Data is greater than the high-level pulse width of the modulated scan signal ScanM, which can ensure the input of the data signal Data when the modulated scan signal ScanM controls the second transistor T2 to be turned on.
  • the modulated scan signal ScanM controls the second transistor T2 to be turned off the potential of the first node N is kept high, so that when the modulated scan signal ScanM is at a low level, the light emitting device LED can still emit light uniformly.
  • Such timing setting can avoid the influence of the modulated scan signal ScanM on the light emission of the display panel.
  • the low-level pulse width of the scanning signal is modulated by the pulse width modulation technology.
  • the high-level pulse time is reduced.
  • the time for the TFT to be subjected to a high-level voltage is also reduced, thereby improving the stability of the TFT and improving the problem of the threshold voltage drift of the TFT.
  • the present application provides a display panel. Please refer to FIG. 7 , which is a schematic structural diagram of the display panel provided by the present application.
  • the display panel 100 provided by the present application includes a backlight module.
  • the backlight module is provided with a plurality of rows of backlight driving circuits, and the backlight driving circuits are driven by the above-mentioned backlight driving methods.
  • the display panel 100 provided by the present application can be used in an electronic device, and the electronic device can be a smart phone (smartphone), a tablet computer (tablet personal computer), a mobile phone (mobile phone) phone), video phone, e-book reader, desktop PC, laptop PC), netbook computer, workstation, server, personal digital assistant digital assistant), portable media player (portable multimedia player), MP3 players, mobile medical machines, cameras, game consoles, digital cameras, car navigators, electronic billboards, ATMs or wearable devices device) at least one.
  • the display panel 100 provided by the present application includes a backlight module, and a backlight driving circuit is disposed on the backlight module.
  • the backlight driving circuit adopts a backlight driving method for driving, and the backlight driving method modulates the low-level pulse width of the scanning signal through a pulse width modulation technique.
  • the backlight driving method modulates the low-level pulse width of the scanning signal through a pulse width modulation technique.

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Abstract

本申请公开了一种背光驱动方法及显示面板。本申请提供的背光驱动方法采用脉冲宽度调制技术对扫描信号的低电平脉冲宽度进行调制。通过增大低电平脉冲宽度以增长脉冲周期，降低高电平脉冲次数，从而减少高电平脉冲时间。则TFT受高电平电压的时间也减少，由此提高了TFT的稳定性，也改善了TFT的阈值电压漂移的问题。

Description

一种背光驱动方法及显示面板 技术领域
本申请涉及显示技术领域，具体涉及一种背光驱动方法及显示面板。
 背景技术
迷你发光二极管（Mini light-emitting diode, Mini LED）背板驱动目前有主动矩阵式（Active Matrix, AM）驱动和被动矩阵式（Passive Matrix, PM）驱动。由于Mini-LED AM驱动中的薄膜晶体管（Thin Film Transistor, TFT）可以起到开关作用，相比PM可以省掉很多驱动集成电路（Integrated Circuit, IC），因此AM驱动相比PM驱动成本更低。AM驱动的背板技术目前有采用非晶硅（α-Si）、铟镓锌氧化物（IGZO）及低温多晶硅（LTPS），TFT的稳定性极大影响着Mini LED的亮度及品味。而在对现有技术的研究和实践过程中，本申请的发明人发现，TFT的稳定性与扫描信号高电平（Scan high）的时间强相关，高电平时间过长会加重TFT的阈值电压漂移（Vth shift），导致稳定性下降。
 技术问题
本申请提供一背光驱动方法以及显示面板，可以增强薄膜晶体管的稳定性。
 技术解决方案
本申请提供一种背光驱动方法，包括：
提供一脉冲宽度调制信号；
根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数；
将所述调制后扫描信号输出至背光驱动电路。
可选的，在本申请的一些实施例中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
增大低电平脉冲宽度，将至少一个所述初始脉冲周期调制为第一脉冲周期，所述第一脉冲周期的时间为至少两个所述初始脉冲周期的时间，以使得所述调制后扫描信号包括多个所述第一脉冲周期。
可选的，在本申请的一些实施例中，一帧内所述待调制扫描信号包括127个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
将一帧内所述待调制扫描信号调制为包括一个所述初始脉冲周期和p个所述第一脉冲周期，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间；其中，p的值为63。
可选的，在本申请的一些实施例中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
增大低电平脉冲宽度，将至少一个初始脉冲周期调制为第一脉冲周期，并将至少一个初始脉冲周期调制为第二脉冲周期，以使得所述调制后扫描信号包括多个所述第一脉冲周期和多个第二脉冲周期，其中，所述初始脉冲周期的时间小于所述第一脉冲周期的时间，所述第一脉冲周期的时间小于所述第二脉冲周期的时间。
可选的，在本申请的一些实施例中，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间，所述第二脉冲周期的时间为四个所述初始脉冲周期的时间。
可选的，在本申请的一些实施例中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
增大低电平脉冲宽度，将一帧内多个初始脉冲周期调制为n个第一脉冲周期和m个第二脉冲周期，以使得一帧内所述调制后扫描信号包括一个初始脉冲周期，n个第一脉冲周期和m个第二脉冲周期，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间，所述第二脉冲周期的时间为四个所述初始脉冲周期的时间；其中，n与m的和为32，m、n为大于1的正整数。
可选的，在本申请的一些实施例中，一帧内所述待调制扫描信号包括127个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
将一帧内所述待调制扫描信号调制为包括一个所述初始脉冲周期、一个所述第一脉冲周期和31个所述第二脉冲周期。
可选的，在本申请的一些实施例中，所述调制后扫描信号包括顺序设置的一个所述初始脉冲周期、一个所述第一脉冲周期以及31个所述第二脉冲周期。
可选的，在本申请的一些实施例中，所述背光驱动方法应用于背光驱动电路中，所述背光驱动电路包括第一晶体管、第二晶体管、存储电容以及发光器件；
所述第一晶体管的源极接入所述发光器件的阴极，所述第一晶体管的漏极接地，所述第一晶体管的栅极与第一节点电性连接；
所述第二晶体管的源极接入数据信号，所述第二晶体管的漏极与第一节点电性连接，所述第二晶体管的栅极接入调制后扫描信号；
所述存储电容的第一端与第一节点电性连接，所述存储电容的第二端接地；
所述发光器件的阳极接入电源信号。
可选的，在本申请的一些实施例中，所述调制后扫描信号为高电平时，所述数据信号为高电平，且所述数据信号的一个高电平脉冲宽度大于所述调制后扫描信号对应的一个高电平脉冲宽度。
相应的，本申请提供一种显示面板，所述显示面板包括背光模组，所述背光模组上设置有背光驱动电路，所述背光驱动电路采用背光驱动方法进行驱动，所述背光驱动方法包括：
提供一脉冲宽度调制信号；
根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数；
将所述调制后扫描信号输出至背光驱动电路。
可选的，在本申请的一些实施例中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
增大低电平脉冲宽度，将至少一个所述初始脉冲周期调制为第一脉冲周期，所述第一脉冲周期的时间为至少两个所述初始脉冲周期的时间，以使得所述调制后扫描信号包括多个所述第一脉冲周期。
可选的，在本申请的一些实施例中，一帧内所述待调制扫描信号包括127个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
将一帧内所述待调制扫描信号调制为包括一个所述初始脉冲周期和p个所述第一脉冲周期，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间；其中，p的值为63。
可选的，在本申请的一些实施例中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
增大低电平脉冲宽度，将至少一个初始脉冲周期调制为第一脉冲周期，并将至少一个初始脉冲周期调制为第二脉冲周期，以使得所述调制后扫描信号包括多个所述第一脉冲周期和多个第二脉冲周期，其中，所述初始脉冲周期的时间小于所述第一脉冲周期的时间，所述第一脉冲周期的时间小于所述第二脉冲周期的时间。
可选的，在本申请的一些实施例中，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间，所述第二脉冲周期的时间为四个所述初始脉冲周期的时间。
可选的，在本申请的一些实施例中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
增大低电平脉冲宽度，将一帧内多个初始脉冲周期调制为n个第一脉冲周期和m个第二脉冲周期，以使得一帧内所述调制后扫描信号包括一个初始脉冲周期、n个第一脉冲周期和m个第二脉冲周期，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间，所述第二脉冲周期的时间为四个所述初始脉冲周期的时间；其中，n与m的和为32，m、n为大于1的正整数。
可选的，在本申请的一些实施例中，一帧内所述待调制扫描信号包括127个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
将一帧内所述待调制扫描信号调制为包括一个所述初始脉冲周期、一个所述第一脉冲周期和31个所述第二脉冲周期。
可选的，在本申请的一些实施例中，所述调制后扫描信号包括顺序设置的一个所述初始脉冲周期、一个所述第一脉冲周期以及31个所述第二脉冲周期。
可选的，在本申请的一些实施例中，所述背光驱动方法应用于背光驱动电路中，所述背光驱动电路包括第一晶体管、第二晶体管、存储电容以及发光器件；
所述第一晶体管的源极接入所述发光器件的阴极，所述第一晶体管的漏极接地，所述第一晶体管的栅极与第一节点电性连接；
所述第二晶体管的源极接入数据信号，所述第二晶体管的漏极与第一节点电性连接，所述第二晶体管的栅极接入调制后扫描信号；
所述存储电容的第一端与第一节点电性连接，所述存储电容的第二端接地；
所述发光器件的阳极接入电源信号。
可选的，在本申请的一些实施例中，所述调制后扫描信号为高电平时，所述数据信号为高电平，且所述数据信号的一个高电平脉冲宽度大于所述调制后扫描信号对应的一个高电平脉冲宽度。
 有益效果
本申请公开了一种背光驱动方法及显示面板。本申请提供的背光驱动方法采用脉冲宽度调制技术对扫描信号的低电平脉冲宽度进行调制。通过增大低电平脉冲宽度以增长脉冲周期，降低高电平脉冲次数，从而减少高电平脉冲时间。则TFT受高电平电压的时间也减少，由此提高了TFT的稳定性，也改善了TFT的阈值电压漂移的问题。
 附图说明
为了更清楚地说明本申请中的技术方案，下面将对实施例描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一些实施例，对于本领域技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1是本申请提供的背光驱动方法的一种流程示意图；
图2是本申请提供的扫描信号的示意图；
图3是本申请提供的扫描信号调制前后的第一种示意图；
图4是本申请提供的扫描信号调制前后的第二种示意图；
图5是本申请提供的背光驱动方法中背光驱动电路的一种电路示意图；
图6是本申请提供的背光驱动方法中背光驱动电路的一种时序示意图；
图7是本申请提供的显示面板的一种结构示意图。
 本发明的实施方式
下面将结合本申请中的附图，对本申请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。
在本申请中，应理解，诸如“包括”或“具有”等的术语旨在指示本说明书中所公开的特征、数字、步骤、行为、部件、部分或其组合的存在，并且不欲排除一个或多个其他特征、数字、步骤、行为、部件、部分或其组合存在或被添加的可能性。
本申请提供一种背光驱动方法及显示面板。以下分别进行详细说明。需说明的是，以下实施例的描述顺序不作为对实施例优选顺序的限定。
请参阅图1，图1是本申请提供的背光驱动方法的一种流程示意图。其中，本申请提供的一种背光驱动方法，具体包括如下步骤：
11、提供一脉冲宽度调制信号。
脉冲宽度调制（Pulsewidthmodulation, PWM）技术是指通过对一系列脉冲的宽度进行调制，等效获得所需要的波形。PWM技术是利用微处理器的数字信号对模拟电路进行控制的一种非常有效的技术。脉宽调制控制技术结构简单、易于实现、技术比较成熟，已经得到了广泛应用。本申请的脉冲宽度调制信号是通过PWM技术得到，在此不做过多赘述。
12、根据脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于待调制扫描信号的高电平脉冲次数。
请参阅图2，图2是本申请提供的扫描信号的示意图。通常在显示面板中，设置有多行背光驱动单元，每行背光驱动单元分别对应一行背光驱动电路。每一行的背光驱动电路分别用扫描信号进行控制，以对背光驱动电路逐行进行扫描。如图2所示，以显示面板具有n行背光驱动电路为例，分别对应有n行扫描信号，分别示意为Scan1、Scan2、……Scan（n-1）以及Scan（n）。其中，一个高电平脉冲宽度加相邻低电平脉冲宽度为一个脉冲周期T。即，脉冲周期T表示由高电平脉冲至下一个高电平脉冲的时间。其中，低电平脉冲宽度D也可称为脉冲间隔。
在图2所示的背光驱动电路扫描信号中，由第一行扫描信号Scan1逐行打开扫描至第n行扫描信号Scan（n）的时间，再加上扫描n行之后下一次扫描开始的垂直消隐周期（vertical blanking interval）称为一个最小子场时间t。其中，最小子场时间t根据显示面板的灰阶和分辨率确定。例如，128灰阶、分辨率为240Hz的显示面板，一帧时间为4.17毫秒（ms），一帧内有128个灰阶，则最小子场时间t为32.6微秒（μs）。以上仅为示例，是为了更好的说明最小子场时间t的概念，并不作为对本申请的限制。
请参阅图3，图3是本申请提供的扫描信号调制前后的第一种示意图。图3以图2中的某一行扫描信号为例，将扫描信号在一帧内的脉冲周期压缩以进行示意。
在一些实施例中，根据脉冲宽度调制信号调制待调制扫描信号ScanO的低电平脉冲宽度，以增大待调制扫描信号ScanO的脉冲周期，使待调制扫描信号ScanO的高电平脉冲次数减少，具体包括如下步骤：
增大低电平脉冲宽度，将至少一个初始脉冲周期P0调制为第一脉冲周期P1。第一脉冲周期P1的时间为至少两个初始脉冲周期P0的时间，以使调制后扫描信号高电平脉冲次数少于待调制扫描信号的高电平脉冲次数。其中，待调制扫描信号ScanO包括多个初始脉冲周期P0，调制后扫描信号ScanM包括多个第一脉冲周期P1。
其中，本申请对调制后扫描信号ScanM中的初始脉冲周期P0和第一脉冲周期P1的数量不做限制，只需要在调制后使其脉冲周期之和占满一帧即可。例如，调制后扫描信号ScanM可以包括一个初始脉冲周期P0和多个第一脉冲周期P1。调制后扫描信号ScanM可以包括多个初始脉冲周期P0和一个第一脉冲周期P1。
具体的，第一脉冲周期P1的时间可以为两个初始脉冲周期P0的时间、三个初始脉冲周期P0的时间、四个初始脉冲周期P0的时间、五个初始脉冲周期P0的时间、六个初始脉冲周期P0的时间、七个初始脉冲周期P0的时间、八个初始脉冲周期P0的时间、十个初始脉冲周期P0的时间、十六个初始脉冲周期P0的时间或三十二个初始脉冲周期P0的时间。
进一步地，请继续参阅图3。增大低电平脉冲宽度，将一帧内的多个初始脉冲周期P0调制为p个第一脉冲周期P1。一帧内待调制扫描信号ScanO包括127个初始脉冲周期P0，一帧内调制后扫描信号ScanM包括一个初始脉冲周期P0和p个第一脉冲周期P1。第一脉冲周期P1的时间为两个初始脉冲周期P0的时间。其中，p的值为63。
具体的，127灰阶的显示面板一帧时间内具有127个最小子场时间t。则一行待调制扫描信号ScanO具有127个初始脉冲周期P0。此时p为127，第一脉冲周期P1的时间为两个初始脉冲周期P0的时间，因此将一帧内的126个初始脉冲周期P0调制为63个第一脉冲周期P1。则调制后扫描信号ScanM包括一个初始脉冲周期P0和63个第一脉冲周期P1。最终将待调制扫描信号ScanO一帧内的127次高电平脉冲调制为调制后扫描信号ScanM的64次高电平脉冲。也就是将TFT受高电平电压作用的时间减小了一半，从而改善了阈值电压的漂移。
在图3中，初始脉冲周期P0和第一脉冲周期P1的排布顺序仅为示意，并不作为对本申请的限制。
请参阅图4，图4是本申请提供的扫描信号调制前后的第二种示意图。同样的，图4以图2中的某一行扫描信号为例，将扫描信号在一帧内的脉冲周期压缩以进行示意。
在一些实施例中，根据脉冲宽度调制信号调制待调制扫描信号ScanO的低电平脉冲宽度，以增大待调制扫描信号ScanO的脉冲周期，使调制后扫描信号ScanM高电平脉冲次数少于待调制扫描信号ScanO的高电平脉冲次数，包括：
增大低电平脉冲宽度，将至少一个初始脉冲周期P0调制为第一脉冲周期P1，并将至少一个初始脉冲周期P0调制为第二脉冲周期P2，以使调制后扫描信号ScanM高电平脉冲次数少于待调制扫描信号ScanO的高电平脉冲次数；其中，待调制扫描信号ScanO包括多个初始脉冲周期P0，调制后扫描信号ScanM包括多个第一脉冲周期P1和多个第二脉冲周期P2，初始脉冲周期P0的时间小于第一脉冲周期P1的时间，第一脉冲周期P1的时间小于第二脉冲周期P2的时间。
其中，本申请对调制后扫描信号ScanM中的初始脉冲周期P0、第一脉冲周期P1和第二脉冲周期P2的数量不做限制，只需要在调制后使其脉冲周期之和占满一帧即可。例如，调制后扫描信号ScanM可以包括一个初始脉冲周期P0、一个第一脉冲周期P1和多个第二脉冲周期P2。调制后扫描信号ScanM可以包括一个初始脉冲周期P0、多个第一脉冲周期P1和一个第二脉冲周期P2。
具体的，第一脉冲周期P1的时间可以为两个初始脉冲周期P0的时间、三个初始脉冲周期P0的时间、四个初始脉冲周期P0的时间、五个初始脉冲周期P0的时间、六个初始脉冲周期P0的时间、七个初始脉冲周期P0的时间、八个初始脉冲周期P0的时间、十个初始脉冲周期P0的时间或十六个初始脉冲周期P0的时间。
具体的，第二脉冲周期P2的时间可以为两个初始脉冲周期P0的时间、三个初始脉冲周期P0的时间、四个初始脉冲周期P0的时间、五个初始脉冲周期P0的时间、六个初始脉冲周期P0的时间、七个初始脉冲周期P0的时间、八个初始脉冲周期P0的时间、十个初始脉冲周期P0的时间、十六个初始脉冲周期P0的时间或三十二个初始脉冲周期P0的时间。
其中，在一些实施例中，第一脉冲周期P1的时间为两个初始脉冲周期P0的时间，第二脉冲周期P2的时间为四个初始脉冲周期P0的时间。
进一步地，请继续参阅图4。将多个初始脉冲周期P0调制为n个第一脉冲周期P1和m个第二脉冲周期P2。调制后扫描信号ScanM包括一个初始脉冲周期P0，n个第一脉冲周期P1、m个第二脉冲周期P2。第一脉冲周期P1的时间为两个初始脉冲周期P0的时间，第二脉冲周期P2的时间为四个初始脉冲周期P0的时间。其中，n与m的和为32，m、n为大于1的正整数。
在一些实施例中，n的值为1，m的值为31。下面以127灰阶显示面板为例进行说明。127灰阶的显示面板一帧时间内具有127个最小子场时间t。则一行待调制扫描信号ScanO具有127个初始脉冲周期P0。n的值为1，m的值为31。因此将一帧内的126个初始脉冲周期P0调制为1个第一脉冲周期P1和31个第二脉冲周期P2。则调制后扫描信号ScanM包括一个初始脉冲周期P0、1个第一脉冲周期P1和31个第二脉冲周期P2。最终将待调制扫描信号ScanO一帧内的127次高电平脉冲调制为调制后扫描信号ScanM的33次高电平脉冲。也就是将TFT受高电平电压作用的时间减小为原本的三分之一。这极大减小了TFT受压时间，也极大地提高了TFT的稳定性，从而改善了阈值电压的漂移。
在图4中，初始脉冲周期P0、第一脉冲周期P1和第二脉冲周期P2的排布顺序仅为示意，并不作为对本申请的限制。
在一种实施例中，显示面板为127灰阶的显示面板。127灰阶的显示面板一帧时间内具有127个最小子场时间t。则一行待调制扫描信号ScanO具有127个初始脉冲周期P0。根据脉冲宽度调制信号对待调制扫描信号ScanO进行调制，调制后扫描信号ScanM具有一个初始脉冲周期P0、一个第一脉冲周期P1、一个第二脉冲周期P2、一个第三脉冲周期P3、一个第四脉冲周期P4和三个第五脉冲周期P5。
其中，第一脉冲周期P1的时间为两个初始脉冲周期P0的时间。第二脉冲周期P2的时间为四个初始脉冲周期P0的时间。第三脉冲周期P3的时间为八个初始脉冲周期P0的时间。第四脉冲周期P4的时间为十六个初始脉冲周期P0的时间。第五脉冲周期P5的时间为三十二个初始脉冲周期P0的时间。
由此，将待调制扫描信号ScanO中的127个高电平脉冲调制为调制后扫描信号ScanM的8个高电平脉冲。大大减少了高电平脉冲次数，极大缩短了高电平脉冲时间。大幅降低了扫描信号对TFT的高电压作用时间，提高了TFT的稳定性，很好地改善了阈值电压发生漂移的问题。
在实际测试中，将脉冲周期调制为大于三十二个初始脉冲周期P0的时间将对显示面板的发光亮度造成影响。因此，为保证显示效果，调制后的脉冲周期范围控制在2至32个初始脉冲周期P0之间。
13、将调制后扫描信号输出至背光驱动电路。
其中，请参阅图5，图5是本申请提供的背光驱动方法中背光驱动电路的一种电路示意图。背光驱动电路10包括第一晶体管T1、第二晶体管T2、存储电容C以及发光器件LED。第一晶体管T1的源极接入发光器件LED的阴极，第一晶体管T1的漏极接地，第一晶体管T1的栅极与第一节点N电性连接。第二晶体管T2的源极接入数据信号Data，第二晶体管T2的漏极与第一节点N电性连接，第二晶体管的T2栅极接入调制后扫描信号ScanM。存储电容C的第一端与第一节点N电性连接，存储电容C的第二端接地。发光器件LED的阳极接入电源信号VDD。
请同时参阅图4和图5，在一种实施例中，调制后扫描信号ScanM包括顺序设置的一个初始脉冲周期P0、一个第一脉冲周期P1以及31个第二脉冲周期P2。采用这样的顺序，能够在第一个初始脉冲周期P0时将第一节点N的电位抬高，并对存储电容C充电，保证发光器件LED的发光效果。之后再延长低电平脉冲宽度，能够降低低电平脉冲宽度对发光器件LED后续发光的影响。
其中，请参阅图6，图6是本申请提供的背光驱动方法中背光驱动电路的一种时序示意图。调制后扫描信号ScanM为高电平时，数据信号Data为高电平，且数据信号Data的一个高电平脉冲宽度大于调制后扫描信号ScanM对应的一个高电平脉冲宽度。
由于本申请提供的调制后扫描信号ScanM减小了高电平脉冲次数，并增大了低电平脉冲宽度。数据信号Data的高电平脉冲宽度大于调制后扫描信号ScanM的高电平脉冲宽度，可以在调制后扫描信号ScanM控制第二晶体管T2打开的时候，保证数据信号Data的输入。在调制后扫描信号ScanM控制第二晶体管T2关闭的时候，使第一节点N的电位保持较高，使调制后扫描信号ScanM处于低电平时，发光器件LED仍能够均匀发光。
这样的时序设置，能够避免调制后扫描信号ScanM对显示面板的发光造成影响。
本申请提供的背光驱动方法，通过脉冲宽度调制技术对扫描信号的低电平脉冲宽度进行调制。通过增大低电平脉冲宽度以增长脉冲周期，降低高电平脉冲次数，从而减少高电平脉冲时间。则TFT受高电平电压的时间也减少，由此提高了TFT的稳定性，也改善了TFT的阈值电压漂移的问题。
本申请提供一种显示面板，请参阅图7，图7是本申请提供的显示面板的一种结构示意图。本申请提供的显示面板100包括背光模组，背光模组上设置有多行背光驱动电路，背光驱动电路采用以上所述的背光驱动方法进行驱动。
本申请提供的显示面板100可以用于电子设备中，电子设备可以为智能手机(smartphone)、平板电脑(tablet personal computer)、移动电话(mobile phone)、视频电话机、电子书阅读器(e-book reader)、台式计算机(desktop PC)、手提电脑(laptop PC)、上网本(netbook computer)、工作站(workstation)、服务器、个人数字助理(personal digital assistant)、便携式媒体播放器(portable multimedia player)、MP3播放器、移动医疗机器、照相机、游戏机、数码相机、车载导航仪、电子广告牌、自动取款机或可穿戴设备(wearable device)中的至少一个。
本申请提供的显示面板100包括背光模组，背光模组上设置有背光驱动电路。背光驱动电路采用了一种背光驱动方法进行驱动，该背光驱动方法通过脉冲宽度调制技术对扫描信号的低电平脉冲宽度进行调制。通过增大低电平脉冲宽度以增长脉冲周期，降低高电平脉冲次数，从而减少高电平脉冲时间。则TFT受高电平电压的时间也减少，由此提高了TFT的稳定性，也改善了TFT的阈值电压漂移的问题。
以上对本申请所提供的一种背光驱动方法及显示面板进行了详细介绍，本文中应用了具体个例对本申请的原理及实施方式进行了阐述，以上实施例的说明只是用于帮助理解本申请的方法及其核心思想；同时，对于本领域的技术人员，依据本申请的思想，在具体实施方式及应用范围上均会有改变之处，综上所述，本说明书内容不应理解为对本申请的限制。

Claims (20)

  1. 一种背光驱动方法，其中，包括：
    提供一脉冲宽度调制信号；
    根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数；
    将所述调制后扫描信号输出至背光驱动电路。
  2. 根据权利要求1所述的背光驱动方法，其中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
    增大低电平脉冲宽度，将至少一个所述初始脉冲周期调制为第一脉冲周期，所述第一脉冲周期的时间为至少两个所述初始脉冲周期的时间，以使得所述调制后扫描信号包括多个所述第一脉冲周期。
  3. 根据权利要求2所述的背光驱动方法，其中，一帧内所述待调制扫描信号包括127个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
    将一帧内所述待调制扫描信号调制为包括一个所述初始脉冲周期和p个所述第一脉冲周期，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间；其中，p的值为63。
  4. 根据权利要求1所述的背光驱动方法，其中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
    增大低电平脉冲宽度，将至少一个初始脉冲周期调制为第一脉冲周期，并将至少一个初始脉冲周期调制为第二脉冲周期，以使得所述调制后扫描信号包括多个所述第一脉冲周期和多个第二脉冲周期，其中，所述初始脉冲周期的时间小于所述第一脉冲周期的时间，所述第一脉冲周期的时间小于所述第二脉冲周期的时间。
  5. 根据权利要求4所述的背光驱动方法，其中，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间，所述第二脉冲周期的时间为四个所述初始脉冲周期的时间。
  6. 根据权利要求1所述的背光驱动方法，其中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
    增大低电平脉冲宽度，将一帧内多个初始脉冲周期调制为n个第一脉冲周期和m个第二脉冲周期，以使得一帧内所述调制后扫描信号包括一个初始脉冲周期、n个第一脉冲周期和m个第二脉冲周期，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间，所述第二脉冲周期的时间为四个所述初始脉冲周期的时间；其中，n与m的和为32，m、n为大于1的正整数。
  7. 根据权利要求6所述的背光驱动方法，其中，一帧内所述待调制扫描信号包括127个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
    将一帧内所述待调制扫描信号调制为包括一个所述初始脉冲周期、一个所述第一脉冲周期和31个所述第二脉冲周期。
  8. 根据权利要求7所述的背光驱动方法，其中，所述调制后扫描信号包括顺序设置的一个所述初始脉冲周期、一个所述第一脉冲周期以及31个所述第二脉冲周期。
  9. 根据权利要求1所述的背光驱动方法，其中，所述背光驱动方法应用于背光驱动电路中，所述背光驱动电路包括第一晶体管、第二晶体管、存储电容以及发光器件；
    所述第一晶体管的源极接入所述发光器件的阴极，所述第一晶体管的漏极接地，所述第一晶体管的栅极与第一节点电性连接；
    所述第二晶体管的源极接入数据信号，所述第二晶体管的漏极与第一节点电性连接，所述第二晶体管的栅极接入调制后扫描信号；
    所述存储电容的第一端与第一节点电性连接，所述存储电容的第二端接地；
    所述发光器件的阳极接入电源信号。
  10. 根据权利要求9所述的背光驱动方法，其中，所述调制后扫描信号为高电平时，所述数据信号为高电平，且所述数据信号的一个高电平脉冲宽度大于所述调制后扫描信号对应的一个高电平脉冲宽度。
  11. 一种显示面板，其中，所述显示面板包括背光模组，所述背光模组上设置有背光驱动电路，所述背光驱动电路采用背光驱动方法进行驱动，所述背光驱动方法包括：
    提供一脉冲宽度调制信号；
    根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数；
    将所述调制后扫描信号输出至背光驱动电路。
  12. 根据权利要求11所述的显示面板，其中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
    增大低电平脉冲宽度，将至少一个所述初始脉冲周期调制为第一脉冲周期，所述第一脉冲周期的时间为至少两个所述初始脉冲周期的时间，以使得所述调制后扫描信号包括多个所述第一脉冲周期。
  13. 根据权利要求12所述的显示面板，其中，一帧内所述待调制扫描信号包括127个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
    将一帧内所述待调制扫描信号调制为包括一个所述初始脉冲周期和p个所述第一脉冲周期，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间；其中，p的值为63。
  14. 根据权利要求11所述的显示面板，其中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
    增大低电平脉冲宽度，将至少一个初始脉冲周期调制为第一脉冲周期，并将至少一个初始脉冲周期调制为第二脉冲周期，以使得所述调制后扫描信号包括多个所述第一脉冲周期和多个第二脉冲周期，其中，所述初始脉冲周期的时间小于所述第一脉冲周期的时间，所述第一脉冲周期的时间小于所述第二脉冲周期的时间。
  15. 根据权利要求14所述的显示面板，其中，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间，所述第二脉冲周期的时间为四个所述初始脉冲周期的时间。
  16. 根据权利要求11所述的显示面板，其中，一帧内所述待调制扫描信号包括多个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
    增大低电平脉冲宽度，将一帧内多个初始脉冲周期调制为n个第一脉冲周期和m个第二脉冲周期，以使得一帧内所述调制后扫描信号包括一个初始脉冲周期、n个第一脉冲周期和m个第二脉冲周期，所述第一脉冲周期的时间为两个所述初始脉冲周期的时间，所述第二脉冲周期的时间为四个所述初始脉冲周期的时间；其中，n与m的和为32，m、n为大于1的正整数。
  17. 根据权利要求16所述的显示面板，其中，一帧内所述待调制扫描信号包括127个初始脉冲周期，所述根据所述脉冲宽度调制信号调制待调制扫描信号的低电平脉冲宽度，以增大所述待调制扫描信号的脉冲周期，使调制后扫描信号高电平脉冲次数少于所述待调制扫描信号的高电平脉冲次数，包括：
    将一帧内所述待调制扫描信号调制为包括一个所述初始脉冲周期、一个所述第一脉冲周期和31个所述第二脉冲周期。
  18. 根据权利要求17所述的显示面板，其中，所述调制后扫描信号包括顺序设置的一个所述初始脉冲周期、一个所述第一脉冲周期以及31个所述第二脉冲周期。
  19. 根据权利要求11所述的显示面板，其中，所述背光驱动方法应用于背光驱动电路中，所述背光驱动电路包括第一晶体管、第二晶体管、存储电容以及发光器件；
    所述第一晶体管的源极接入所述发光器件的阴极，所述第一晶体管的漏极接地，所述第一晶体管的栅极与第一节点电性连接；
    所述第二晶体管的源极接入数据信号，所述第二晶体管的漏极与第一节点电性连接，所述第二晶体管的栅极接入调制后扫描信号；
    所述存储电容的第一端与第一节点电性连接，所述存储电容的第二端接地；
    所述发光器件的阳极接入电源信号。
  20. 根据权利要求19所述的显示面板，其中，所述调制后扫描信号为高电平时，所述数据信号为高电平，且所述数据信号的一个高电平脉冲宽度大于所述调制后扫描信号对应的一个高电平脉冲宽度。
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