CN115881026A - Display panel, driving method of display panel and display device - Google Patents

Display panel, driving method of display panel and display device Download PDF

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Publication number
CN115881026A
CN115881026A CN202210946196.8A CN202210946196A CN115881026A CN 115881026 A CN115881026 A CN 115881026A CN 202210946196 A CN202210946196 A CN 202210946196A CN 115881026 A CN115881026 A CN 115881026A
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China
Prior art keywords
signal
sweep
sub
stage
driving circuit
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Chinese (zh)
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叶本银
黄秀颀
徐尚君
黄亚东
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Chengdu Vistar Optoelectronics Co Ltd
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Chengdu Vistar Optoelectronics Co Ltd
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Priority to CN202210946196.8A priority Critical patent/CN115881026A/en
Publication of CN115881026A publication Critical patent/CN115881026A/en
Priority to PCT/CN2023/108304 priority patent/WO2024032340A1/en
Priority to TW112128696A priority patent/TW202407672A/en
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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]

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

Abstract

The invention discloses a display panel, a driving method of the display panel and a display device. The display panel comprises a pulse width modulation driving circuit and a light-emitting unit, wherein the pulse width modulation driving circuit is connected with the light-emitting unit; one frame time of the display panel comprises a data writing stage and a light-emitting stage, wherein the light-emitting stage comprises at least two sub-stages; the driving method of the display panel comprises the following steps: in the data writing stage, providing a data signal to the pulse width modulation driving circuit; in at least one sub-stage, providing a sweep frequency signal to the pulse width modulation driving circuit, so that the pulse width modulation driving circuit controls the light emitting time of the light emitting unit according to the data signal and the sweep frequency signal; each sub-stage for providing the frequency sweeping signal corresponds to a frequency sweeping signal. The invention can improve the splash screen phenomenon of the display panel. And the light-emitting time of the light-emitting unit can be integrally adjusted, so that the whole screen brightness of the display panel can be integrally adjusted.

Description

Display panel, driving method of display panel and display device
Technical Field
The embodiment of the invention relates to the technical field of display, in particular to a display panel, a driving method of the display panel and a display device.
Background
The Active-matrix micro light emitting diode (AM micro-LED) display panel includes a pixel driving circuit and a light emitting device, wherein the pixel driving circuit provides a driving current for the light emitting device to drive the light emitting device to emit light, thereby realizing display of the display panel. When the pixel driving circuit supplies a driving current to the light emitting device, the gray scale of the display panel can be expressed by adjusting a driving time (or a Pulse Width) of the driving current, and this driving method is called a Pulse Width Modulation (PWM) driving method. When the pixel driving circuit is driven by the PWM driving method, a sweep frequency signal (e.g., a triangular wave or a ramp wave) provided from the outside may be compared with a data voltage signal, and the on/off of the control transistor of the pixel driving circuit may be controlled according to the comparison result, so as to control the time for the pixel driving current to provide the driving current to the light emitting device, and further control the light emitting time of the light emitting device.
In the prior art, when the pixel driving circuit is driven by the PWM driving method, when the display panel displays low gray scale luminance, the ratio of the time of the pixel driving circuit driving the light emitting device to emit light in one frame time is relatively small, and the phenomenon of screen flashing is likely to occur, which affects the display effect of the display panel. Moreover, when the pixel driving circuit is driven by adopting the PWM driving method, the brightness of the display panel cannot be adjusted in the whole screen, and the use experience of a user is reduced.
Disclosure of Invention
The invention provides a display panel, a driving method of the display panel and a display device, which are used for adjusting the whole screen brightness of the display panel and improving the display effect of the display panel.
In a first aspect, an embodiment of the present invention provides a driving method for a display panel, where the display panel includes a pulse width modulation driving circuit and a light emitting unit, and the pulse width modulation driving circuit is connected to the light emitting unit; one frame time of the display panel comprises a data writing phase and a light-emitting phase, wherein the light-emitting phase comprises at least two sub-phases; the driving method of the display panel includes:
in the data writing stage, providing a data signal to the pulse width modulation driving circuit;
providing a sweep frequency signal to the PWM driving circuit at least at one sub-stage, so that the PWM driving circuit controls the light emitting time of the light emitting unit according to the data signal and the sweep frequency signal; wherein each sub-stage providing a sweep signal corresponds to one sweep signal.
Optionally, the frequency sweeping signal includes a hold stage, and a level of the frequency sweeping signal in the hold stage is located outside a range of data signals corresponding to different gray scales; before providing the sweep frequency signal to the pwm driving circuit in at least one of the sub-stages, the method further includes:
increasing the duration of the holding stage of the sweep frequency signal in the ith sub-stage; wherein the duration of the increase is equal to the duration of the data writing phase, and i is an integer greater than or equal to 2.
Optionally, increasing the duration of the holding phase of the sweep signal in the ith sub-phase includes:
inserting a level signal of the duration of the data writing stage in the holding stage of the sweep frequency signal; the level signal is located outside the range of the data signal corresponding to different gray scales, and the level signal with at least partial duration is unchanged.
Optionally, the sweep signal comprises a sweep phase; the level of the frequency sweeping signal in the frequency sweeping stage changes in the range of data signals corresponding to different gray scales; providing a swept frequency signal to the pwm driver circuit during at least one of the sub-phases, comprising:
triggering the sweep frequency stage of the sweep frequency signal to output to the pulse width modulation driving circuit at part of the sub-stages, so that the pulse width modulation driving circuit controls the light emitting time of the light emitting unit according to the data signal and the sweep frequency signal;
in part of the sub-stages, the output of the sweep frequency stage of the sweep frequency signal to the pulse width modulation driving circuit is closed; and the sub-stage for triggering the output of the frequency sweeping stage of the frequency sweeping signal and the sub-stage for closing the output of the frequency sweeping stage of the frequency sweeping signal are regularly arranged.
Optionally, the frequency sweeping signal further includes a holding stage, and a level of the frequency sweeping signal in the holding stage is located outside a range of data signals corresponding to different gray scales; in part of the sub-stages, turning off the output of the sweep frequency stage of the sweep frequency signal to the pwm driving circuit includes:
and in part of the sub-phases, controlling the sweep frequency signal to output the level of the holding phase to the pulse width modulation driving circuit in the sweep frequency phase.
Optionally, in at least one of the sub-stages, providing a frequency sweep signal to the pwm driving circuit includes:
and at least two sub-stages periodically provide the sweep frequency signal to the pulse width modulation driving circuit in different frames of the display panel.
Optionally, the sweep signal comprises a sweep phase; the level of the frequency sweeping signal in the frequency sweeping stage changes within the range of data signals corresponding to different gray scales; before providing the sweep frequency signal to the pwm driving circuit in at least one of the sub-stages, the method further includes:
adjusting the slope of the sweep frequency signal in the sweep frequency phase;
preferably, the slopes of the sweep signals in the sweep phase in different sub-phases are equal.
In a second aspect, an embodiment of the present invention further provides a display panel, including a driving unit, a pulse width modulation driving circuit, and a light emitting unit;
the pulse width modulation driving circuit is connected with the light emitting unit; one frame time of the display panel comprises a data writing phase and a light-emitting phase, wherein the light-emitting phase comprises at least two sub-phases; the driving unit is connected with the pulse width modulation driving circuit, and is configured to provide a data signal to the pulse width modulation driving circuit in the data writing stage, and provide a frequency sweep signal to the pulse width modulation driving circuit in at least one of the sub-stages, so that the pulse width modulation driving circuit controls the light emitting time of the light emitting unit according to the data signal and the frequency sweep signal; wherein each sub-stage providing a sweep signal corresponds to one sweep signal.
Optionally, the driving unit includes a data signal generation module, a sweep signal generation module, and a switching module;
the data signal generating module is connected with a first input end of the switching module, the data signal generating module is used for providing the data signal, the sweep frequency signal generating module is connected with a second input end of the switching module, the sweep frequency signal generating module is used for providing the sweep frequency signal, an output end of the switching module is connected with the pulse width modulation driving circuit, and the switching module is used for switching the data signal generating module or the sweep frequency signal generating module to be communicated with the pulse width modulation driving circuit;
preferably, the switching module includes a switch, a first end of the switch is connected to the data signal generating module, a second end of the switch is connected to the sweep signal generating module, and an output end of the switch is connected to the pwm driving circuit.
In a third aspect, an embodiment of the present invention further provides a display device, including the display panel described in the second aspect.
According to the technical scheme of the embodiment of the invention, the lighting phase comprises at least two sub-phases, each sub-phase for providing the frequency sweep signal corresponds to a frequency sweep signal, and at least one sub-phase, the frequency sweep signal is provided to the pulse width modulation driving circuit, so that the pulse width modulation driving circuit controls the lighting time of the lighting unit according to the data signal and the frequency sweep signal, the lighting time of the lighting unit can be divided into different sub-phases, the non-lighting time of the display panel in each sub-phase can be reduced under the condition that the lighting time of the lighting unit occupies the same frame time, the reduction degree of the lighting brightness of the display panel can be reduced, meanwhile, the switching frequency of the lighting brightness of the display panel can be multiplied in the frame time, the flicker frequency of the display panel can be further multiplied, the flicker frequency of the display panel can be favorably beyond the sensing range of human eyes, and the flicker phenomenon of the display panel when displaying low gray scale can be improved. Moreover, by controlling the number of the sub-stages providing the sweep frequency signal, the light emitting time of the light emitting unit can be integrally adjusted when the data voltage is unchanged, namely the proportion of the light emitting time of the light emitting unit in each sub-stage is unchanged, and the whole screen brightness of the display panel can be integrally adjusted.
Drawings
Fig. 1 is a timing diagram illustrating a driving method of a pixel driving circuit using a PWM driving method according to the prior art;
fig. 2 is a schematic structural diagram of a display panel according to an embodiment of the present invention;
fig. 3 is a schematic flowchart illustrating a driving method of a display panel according to an embodiment of the present invention;
fig. 4 is a schematic signal timing diagram of a display panel according to an embodiment of the present invention;
FIG. 5 is a schematic signal timing diagram of another display panel according to an embodiment of the present invention;
FIG. 6 is a signal timing diagram of another display panel according to an embodiment of the present invention;
FIG. 7 is a signal timing diagram of another display panel according to an embodiment of the present invention;
fig. 8 is a flowchart illustrating another driving method of a display panel according to an embodiment of the invention;
FIG. 9 is a schematic signal timing diagram of another display panel according to an embodiment of the present invention;
fig. 10 is a schematic structural diagram of another display panel according to an embodiment of the disclosure;
FIG. 11 is a signal timing diagram of a first frame of a display panel according to an embodiment of the present invention;
FIG. 12 is a signal timing diagram of a second frame of a display panel according to an embodiment of the present invention;
FIG. 13 is a signal timing diagram of a third frame of a display panel according to an embodiment of the present invention;
FIG. 14 is a signal timing diagram of a fourth frame of a display panel according to an embodiment of the present invention;
FIG. 15 is a timing diagram of a first frame of a display panel according to another embodiment of the present invention;
FIG. 16 is a timing diagram of a second frame of a display panel according to an embodiment of the present invention;
FIG. 17 is a timing diagram illustrating a third frame of signals of another display panel according to an embodiment of the present invention;
FIG. 18 is a timing diagram illustrating a fourth frame of a display panel according to an embodiment of the present invention;
FIG. 19 is a schematic diagram illustrating a signal timing sequence of another display panel according to an embodiment of the present invention;
FIG. 20 is a signal timing diagram of another display panel according to an embodiment of the present invention;
FIG. 21 is a schematic signal timing diagram of another display panel according to an embodiment of the present invention;
fig. 22 is a schematic structural diagram of another display panel according to an embodiment of the disclosure;
fig. 23 is a schematic structural diagram of a display device according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.
Fig. 1 is a timing diagram illustrating a driving method of a pixel driving circuit according to a PWM driving method in the prior art. As shown in fig. 1, a frame time t of the display panel can be divided into a data writing period t1 and a light emitting period t2. In the data writing phase t1, the data voltage data is input to the pixel driving circuit. In the light emitting phase t2, under the trigger action of the trigger signal set, the frequency sweep signal sweep (exemplarily shown in fig. 1 that the frequency sweep signal sweep is a ramp signal) starts to sweep, and when the voltage of the frequency sweep signal sweep is greater than the data voltage data, the control transistor of the pixel driving circuit is turned on, so as to control the time for the pixel driving circuit to provide the driving current to the light emitting device. The different display gray scales of the display panel correspond to different data voltages data. Illustratively, when the control transistor of the pixel driving circuit is a P-type transistor, the smaller the display gray scale of the display panel, the larger the voltage value of the data voltage data. The smaller the time that the voltage of the sweep signal sweep is greater than the data voltage data is, the shorter the time that a control transistor of the pixel driving circuit is turned on is, the shorter the light emitting time of the corresponding light emitting device in one frame is, and the longer the non-light emitting time of the display panel is. In the non-light-emitting time of the display panel, the light-emitting brightness of the display panel is reduced due to phenomena such as leakage current of the pixel driving circuit, and the phenomenon of screen flashing easily occurs between frames. For example, when the maximum display gray scale of the display panel is 255 and the display gray scale of the display panel is 32, the light emitting time t32 of the light emitting device only occupies about 32/255 of one frame time when the display gray scale of the display panel is 32. Moreover, as can be seen from fig. 1, when the pixel driving circuit is driven by the PWM driving method, the luminance of the display panel cannot be adjusted on the whole screen, which reduces the user experience.
In view of the above technical problems, embodiments of the present invention provide a driving method for a display panel, which is used for driving an AM micro-LED display panel. Exemplarily, fig. 2 is a schematic structural diagram of a display panel according to an embodiment of the present invention. The display panel includes a pulse width modulation driving circuit 10 and a light emitting unit 20, and the pulse width modulation driving circuit 10 is connected to the light emitting unit 20. The PWM driving circuit 10 includes a PWM part 11 and a control transistor T1, an output terminal of the PWM part 11 is connected to a control electrode of the control transistor T1, and the PWM driving circuit controls a light emitting time of the light emitting unit 20 by turning on or off the control transistor T1, so as to control a gray scale and a display brightness of the display panel. Referring to fig. 2, the display panel further includes a driving unit 30, and the driving unit 30 is connected to the PWM part 11 of the PWM driving circuit 10 for providing a driving signal to the PWM part 11 of the PWM driving circuit 10. The driving signal may include a data signal and a frequency sweep signal. Fig. 3 is a schematic flowchart of a driving method of a display panel according to an embodiment of the present invention. As shown in fig. 2 and 3, the driving method of the display panel includes:
s110, in a data writing stage, providing a data signal to a pulse width modulation driving circuit;
when the pwm driving circuit 10 drives the light emitting unit 20 to emit light, the operation process of the pwm driving circuit 10 can be divided into a data writing stage and a light emitting stage. The driving unit 30 may provide the pulse width modulation driving circuit 10 with a data signal during a data writing phase. The driving unit 30 may be a driving chip of the display panel. The data signals can be determined according to the display gray scale of the display panel, and different display gray scales correspond to different data signals.
S120, in at least one sub-stage, providing a sweep frequency signal to the pulse width modulation driving circuit, and enabling the pulse width modulation driving circuit to control the light emitting time of the light emitting unit according to the data signal and the sweep frequency signal; each sub-stage for providing the frequency sweeping signal corresponds to a frequency sweeping signal.
When a sweep frequency signal is provided in a sub-stage, the duration of the sub-stage can be equal to the period of the sweep frequency signal provided in the sub-stage, so that a complete sweep frequency signal can be output in one sub-stage, that is, the sub-stage providing the sweep frequency signal corresponds to a sweep frequency signal. In at least one sub-stage, when the driving unit 30 outputs the sweep frequency signal to the pwm driving circuit 10, the sweep frequency signal may be provided to the pwm driving circuit 10 in each sub-stage, or the sweep frequency signal may be provided to the pwm driving circuit 10 in some sub-stages, or the sweep frequency signal may be provided to the pwm driving circuit 10 only in one sub-stage. When the sweep frequency signal is provided to the pwm driving circuit 10 in at least two sub-stages, the pwm driving circuit 10 can control the light emitting time of the light emitting unit 20 according to the data signal and the sweep frequency signal in each sub-stage of providing the sweep frequency signal to the pwm driving circuit 10. So that the lighting time of the lighting unit 20 within a lighting phase can be divided into different sub-phases. When the display panel displays low gray scale brightness, the light emitting time of the light emitting unit 20 corresponding to the low gray scale brightness can be divided into different sub-phases, under the condition that the light emitting time of the light emitting unit 20 corresponding to the low gray scale brightness occupies unchanged time of one frame, the non-light emitting time of the display panel in each sub-phase can be reduced, the reduction degree of the light emitting brightness of the display panel is reduced, meanwhile, the switching frequency of the light emitting brightness of the display panel can be multiplied in the time of one frame, the flash frequency of the display panel can be further multiplied, the flash frequency of the display panel is favorable for exceeding the sensing range of human eyes, and therefore the flash phenomenon of the display panel when displaying the low gray scale can be improved. Exemplarily, fig. 4 is a schematic signal timing diagram of a display panel according to an embodiment of the present invention. The data is a time sequence of the data signal, and the sweep is a time sequence of the sweep signal. As shown in fig. 4, a frame time t of the display panel can be divided into a data writing phase t1 and a light emitting phase t2, and the light emitting phase t2 includes four sub-phases t21, t22, t23 and t24. Each sub-stage provides a frequency sweep signal, and the duration of each sub-stage corresponds to the period of a frequency sweep signal, so that each sub-stage can output a complete frequency sweep signal, that is, the light-emitting stage t2 can output four frequency sweep signals. Fig. 4 exemplarily shows that the driving unit 30 outputs the sweep frequency signal to the pwm driving circuit 10 in each sub-phase, so that the light emitting time of the light emitting unit 20 in the light emitting phase can be divided into 4 sub-phases under the condition that the data voltage is not changed, i.e. the display gray scale of the display panel is not changed. When the display panel displays low gray-scale luminance, under the condition that the light-emitting time of the light-emitting unit 20 corresponding to the low gray-scale luminance is ensured to occupy the same time of one frame, the non-light-emitting time of the display panel in each sub-phase can be reduced, and the degree of the reduction of the light-emitting luminance of the display panel is reduced. Meanwhile, the switching frequency of the luminous brightness of the display panel can be multiplied within the time of one frame, so that the screen flashing frequency of the display panel can be multiplied, the screen flashing frequency of the display panel is favorable for exceeding the perception range of human eyes, and the screen flashing phenomenon of the display panel when low gray scales are displayed can be improved. For example, when the refresh frequency of the display panel is 60HZ, the frequency of the splash screen is increased by 4 times to 240HZ from 60HZ, which exceeds the perception range of human eyes, thereby improving the splash screen phenomenon of the display panel.
In addition, when the sweep frequency signal is provided to the pwm driving circuit 10 in a part of the sub-phases, when the data voltage is not changed and the ratio of the light emitting time of the light emitting unit 20 in each sub-phase is not changed, the light emitting time of the light emitting unit 20 can be reduced as a whole, and the brightness of the entire screen of the display panel can be adjusted as a whole. Exemplarily, fig. 5 is a schematic signal timing diagram of another display panel according to an embodiment of the present invention. As shown in fig. 5, the lighting phase includes four sub-phases, and the duration of each sub-phase is equal. In fig. 5, it is exemplarily shown that in the first sub-phase and the third sub-phase, the driving unit 30 outputs the sweep frequency signal to the pwm driving circuit 10, and the duration of the first sub-phase and the third sub-phase is equal to the period of the sweep frequency signal provided by the sub-phase, and in the second sub-phase and the fourth sub-phase, the driving unit 30 turns off the output of the sweep frequency signal. Under the condition that the data voltage is not changed, that is, when the display gray scale of the display panel is not changed, the proportion of the light-emitting time of the light-emitting unit 20 in one frame time is reduced by 50%, so that the whole-screen brightness of the display panel is reduced by 50%, and the whole-screen brightness adjustment of the display panel is realized.
It should be noted that fig. 4 and 5 exemplarily show that the sweep signal is a ramp signal. In other embodiments, the frequency sweep signal may also include other forms of signals, such as a triangular wave signal, and the like, and it is only necessary that the level of the frequency sweep signal is changed during the frequency sweep. In addition, with continued reference to fig. 3 to 5, the sweep signal includes a hold phase and a sweep phase, and the driving unit 30 can also provide the trigger signal set for the pwm driving circuit 10. And in the holding stage of the sweep frequency signal, the level of the sweep frequency signal is positioned outside the range of the data signal corresponding to different gray scales. When the trigger signal set outputs a transition edge, the trigger signal set triggers the sweep frequency signal to enter a sweep frequency phase, so that the pwm driving circuit 10 controls the light emitting time of the light emitting unit 20 according to the sweep frequency signal and the data signal in the sweep frequency phase. Exemplarily, as shown in fig. 4 to fig. 5, when the trigger signal set outputs a transition edge that is changed from a low level to a high level, the sweep signal is triggered to enter the sweep phase, so that the pwm driving circuit 10 controls the light emitting time of the light emitting unit 20 according to the sweep signal and the data signal in the sweep phase.
According to the technical scheme, the lighting phase comprises at least two sub-phases, each sub-phase for providing the frequency sweeping signal corresponds to a frequency sweeping signal, and at least one sub-phase, the frequency sweeping signal is provided to the pulse width modulation driving circuit, so that the pulse width modulation driving circuit controls the lighting time of the lighting unit according to the data signal and the frequency sweeping signal, the lighting time of the lighting unit can be divided into different sub-phases, under the condition that the lighting time of the lighting unit occupies a frame, the non-lighting time of the display panel in each sub-phase can be reduced, the degree of the reduction of the lighting brightness of the display panel is reduced, the switching frequency of the lighting brightness of the display panel can be multiplied in the frame, the flicker frequency of the display panel can be multiplied, the flicker frequency of the display panel can be favorably beyond the perception range of human eyes, and the flicker phenomenon of the display panel when displaying low gray scales can be improved. Moreover, by controlling the number of the sub-stages providing the sweep frequency signal, the light emitting time of the light emitting unit can be integrally adjusted when the data voltage is unchanged, namely the proportion of the light emitting time of the light emitting unit in each sub-stage is unchanged, and the whole screen brightness of the display panel can be integrally adjusted.
On the basis of the technical scheme, the sweep frequency signal comprises a holding stage, and the level of the sweep frequency signal in the holding stage is positioned outside the range of the data signals corresponding to different gray scales; before providing the sweep frequency signal to the pwm driving circuit in at least one sub-stage, the method further includes:
increasing the duration of a holding stage of the ith sub-stage frequency sweeping signal; wherein the duration of the increase is equal to the duration of the data writing phase, and i is an integer greater than or equal to 2.
The sweep frequency signal may include a hold phase and a sweep frequency phase, and in the hold phase, the level of the sweep frequency signal is outside the range of the data signal, and at this time, the light-emitting unit is in a non-light-emitting state. During the frequency sweep phase, the frequency sweep signal may be ramped. And the pulse width modulation driving circuit controls the light-emitting time of the light-emitting unit according to the sweep frequency signal and the data signal in the sweep frequency stage. For example, in the frequency sweeping stage, when the frequency sweeping signal is greater than the data signal, the pwm driving circuit controls the light emitting unit to be in the light emitting state according to the frequency sweeping signal and the data signal, so that when the data signal changes according to different display gray scales, the pwm driving circuit can control the light emitting time of the light emitting unit to change according to the frequency sweeping signal and the data signal, thereby adjusting the display gray scale of the display panel.
After the duration of one frame of the display panel is divided into a data writing phase and a light emitting phase, a sweep frequency signal is provided to the pulse width modulation driving circuit in the first sub-phase, and before the pulse width modulation driving circuit controls the light emitting unit to emit light according to the data signal and the sweep frequency signal, the non-light emitting time of the display panel comprises the duration of the data writing phase and the duration of a holding phase of the sweep frequency signal provided by the first sub-phase. And providing a sweep frequency signal to the pulse width modulation driving circuit at the ith sub-stage, wherein the non-luminous time of the display panel comprises the duration of the holding stage of the sweep frequency signal provided by the ith sub-stage before the pulse width modulation driving circuit controls the luminous unit to emit light according to the data signal and the sweep frequency signal. By increasing the duration of the holding stage of the ith sub-stage sweep frequency signal and enabling the increased duration to be equal to the duration of the data writing stage, the non-light-emitting time corresponding to different sub-stages is enabled to be equal, so that the duration of one frame of the display panel can be equally divided into a plurality of sub-stages, and each sub-stage comprises equal non-light-emitting time and equal light-emitting time, thereby further improving the splash screen phenomenon of the display panel.
It should be noted that, after the duration of the holding phase of the ith sub-phase frequency sweep signal is increased, the duration corresponding to the ith sub-phase is longer than the duration corresponding to the first sub-phase. When the first sub-stage and the ith sub-stage both provide the frequency sweep signal, the period of the frequency sweep signal provided by the ith sub-stage is greater than that of the frequency sweep signal provided by the first sub-stage.
Exemplarily, fig. 6 is a schematic signal timing diagram of another display panel according to an embodiment of the present invention. As shown in fig. 6, increasing the duration of the holding phase of the ith sub-phase frequency sweep signal includes:
inserting a level signal of the duration of a data writing stage in a holding stage of the sweep frequency signal; the level signal is located outside the range of the data signal corresponding to different gray scales, and the level signal with at least partial duration is unchanged.
In particular, fig. 6 exemplarily shows that the lighting phase includes four sub-phases, t21, t22, t23 and t24, respectively. Each sub-stage comprises a holding stage t25, and when the second sub-stage to the fourth sub-stage are performed, the level output time t1 'of the holding stage t25 can be increased, the level output time t1' of the holding stage t25 is the time t1 of the data writing stage, and the time of the sweep signal holding stage t25 is further increased, so that the time of one frame of the display panel can be equally divided into a plurality of sub-stages, and each sub-stage comprises equal non-light-emitting time and light-emitting time, so that the splash screen phenomenon of the display panel can be further improved. As shown in fig. 6, the level output from the sweep signal holding stage t25 is kept unchanged. With continued reference to fig. 6, the trigger signal set triggers the synchronization delay of the transition edge of the sweep frequency signal entering the sweep frequency phase, so that the sweep frequency signal triggers the sweep frequency signal entering the sweep frequency phase when the hold phase t25 ends.
In other embodiments, the varying level signal of the duration t1 of the data writing phase may also be inserted during the holding phase t25 of the sweep signal. Exemplarily, fig. 7 is a schematic signal timing diagram of another display panel according to an embodiment of the present invention. As shown in fig. 7, when the level signal of the duration t1 of the data writing phase is inserted in the holding phase t25 of the sweep signal, the level signal may include a portion of the level change. Specifically, fig. 7 exemplarily shows that the light-emitting phase includes four sub-phases, and in the second sub-phase to the fourth sub-phase, the output of the ramp signal can be increased in the holding phase t25, and the minimum level of the ramp signal is located outside the range of the data signal, so that the duration of the holding phase t25 of the sweep signal can be increased on the basis of ensuring that the light-emitting unit is in the non-light-emitting state.
It should be noted that the data writing phase may include an initialization phase. In the initialization stage, the initialization signal provided by the driving unit initializes the PWM driving circuit to improve the accuracy of writing data signals into the PWM driving circuit.
On the basis of the technical schemes, the frequency sweeping signal comprises a frequency sweeping stage; the level of the sweep frequency signal at the sweep frequency stage changes within the range of the data signals corresponding to different gray scales. Fig. 8 is a schematic flowchart of another driving method of a display panel according to an embodiment of the present invention. As shown in fig. 8, the driving method of the display panel includes:
s210, in a data writing stage, providing a data signal to a pulse width modulation driving circuit;
s220, in a partial sub-stage, triggering the frequency sweeping stage of the frequency sweeping signal to output to a pulse width modulation driving circuit, and enabling the pulse width modulation driving circuit to control the light emitting time of the light emitting unit according to the data signal and the frequency sweeping signal;
when the light-emitting stage comprises at least two sub-stages, the sweep frequency stage of triggering the sweep frequency signal in part of the sub-stages can be output to the pulse width modulation driving circuit, so that the pulse width modulation driving circuit controls the light-emitting time of the light-emitting unit according to the data signal and the sweep frequency signal in the sweep frequency stage. In the sub-phase, the proportion of the light-emitting time of the light-emitting unit in the sub-phase of the frequency sweep phase for outputting the frequency sweep signal is equal to the proportion of the light-emitting time of the light-emitting unit in the sum of the durations of the sub-phases of the frequency sweep phase for outputting the frequency sweep signal, so that the display panel displays the display gray scale brightness corresponding to the data signal.
S230, in a partial sub-stage, closing the frequency sweeping stage output of the frequency sweeping signal to the pulse width modulation driving circuit; the sub-stage output by the frequency sweeping stage for triggering the frequency sweeping signal and the sub-stage output by the frequency sweeping stage for closing the frequency sweeping signal are regularly arranged.
In a partial sub-stage, the output of the sweep frequency stage of the sweep frequency signal to the pulse width modulation driving circuit can be closed, and then in the sub-stage, the pulse width modulation driving circuit controls the light-emitting unit to be in a non-light-emitting state, so that the light-emitting time of the light-emitting unit is integrally reduced, and the brightness of the whole screen of the display panel is integrally adjusted. Moreover, the sub-stages output by the frequency sweeping stage for triggering the frequency sweeping signal and the sub-stages output by the frequency sweeping stage for closing the frequency sweeping signal are regularly arranged, so that the light emitting time of the light emitting units in different sub-stages is regularly distributed in the light emitting stage of the display panel, and the screen flashing phenomenon of the display panel can be improved on the basis of adjusting the whole screen brightness of the display panel.
Exemplarily, fig. 9 is a schematic signal timing diagram of another display panel according to an embodiment of the present invention. As shown in fig. 9, the light-emitting phase includes four sub-phases, and the sub-phase for triggering the output of the frequency sweeping phase of the frequency sweeping signal and the sub-phase for turning off the output of the frequency sweeping phase of the frequency sweeping signal can be alternately set, so that in the first sub-phase and the third sub-phase, the pwm driving circuit controls the light-emitting time of the light-emitting unit according to the data signal and the frequency sweeping signal in the frequency sweeping phase. In the second sub-stage and the fourth sub-stage, the PWM driving circuit controls the light-emitting unit to be in a non-light-emitting state. Therefore, when the sweep frequency stages of the sweep frequency signals are all triggered by the four sub-stages and output to the pulse width modulation driving circuit, half of the light-emitting time of the light-emitting unit is integrally reduced on the basis of the whole screen brightness of the display panel, the whole screen brightness of the display panel is reduced by 50%, and the whole screen brightness of the display panel can be adjusted. Meanwhile, the screen flashing frequency of the display panel can be increased in multiples, the screen flashing frequency of the display panel is favorable for exceeding the sensing range of human eyes, and therefore the screen flashing phenomenon of the display panel when displaying low gray scales can be improved.
It should be noted that fig. 9 exemplarily shows that the sub-stages for triggering the output of the frequency sweep stage of the frequency sweep signal and the sub-stages for turning off the output of the frequency sweep stage of the frequency sweep signal are regularly arranged on the basis that the duration of the holding stage of the frequency sweep signal is increased in the ith sub-stage. In other embodiments, after the light-emitting stage is directly divided into at least two sub-stages, the sub-stage for triggering the output of the frequency sweep stage of the frequency sweep signal and the sub-stage for turning off the output of the frequency sweep stage of the frequency sweep signal may be regularly arranged, which is not limited herein. For example, as shown in fig. 5. In addition, in fig. 9, only the sub-stage for triggering the output of the frequency sweep stage of the frequency sweep signal and the sub-stage for turning off the output of the frequency sweep stage of the frequency sweep signal are exemplarily and alternately arranged, and in other embodiments, the sub-stage for triggering the output of the frequency sweep stage of the frequency sweep signal and the sub-stage for turning off the output of the frequency sweep stage of the frequency sweep signal may also be arranged to have other arrangement rules, which is not limited herein. In an exemplary embodiment, the first sub-stage and the second sub-stage can also be set to trigger the output of the sweep frequency stages of the sweep frequency signals to the pwm driving circuit, and the output of the sweep frequency stages of the sweep frequency signals to the pwm driving circuit is turned off in the third sub-stage and the fourth sub-stage.
On the basis of the technical scheme, the frequency sweeping signal also comprises a holding stage, and the level of the frequency sweeping signal in the holding stage is positioned outside the range of the data signals corresponding to different gray scales; in a partial sub-stage, the output of the sweep frequency stage of the turn-off sweep frequency signal to the pulse width modulation driving circuit comprises:
and in a partial sub-phase, controlling the sweep frequency signal to output the level of the holding phase to the pulse width modulation driving circuit in the sweep frequency phase.
When the sweep frequency stage of the sweep frequency signal needs to be closed, the level of the holding stage can be output in the sweep frequency stage of the sweep frequency signal, so that the level of the sweep frequency signal in the sweep frequency stage is positioned outside the range of the data signals corresponding to different gray scales, and the pulse width modulation driving circuit controls the light-emitting unit to be in a non-light-emitting state, so that the sweep frequency stage of the sweep frequency signal in the sub-stage is closed and is output to the pulse width modulation driving circuit. When the level of the sweep frequency signal output holding stage is controlled to the pulse width modulation driving circuit, the level of the sweep frequency signal output holding stage in the sweep frequency stage can be controlled through the driving unit.
With continued reference to fig. 9, the pwm driving circuit may also input a trigger signal set. When the sweep frequency stage of the sweep frequency signal needs to be closed, the level of the trigger signal set can be controlled to be kept unchanged in the sub-stage, so that the trigger signal set can be prevented from forming a jump edge in the sub-stage, the sweep frequency signal can be prevented from being triggered by the trigger signal set to enter the sweep frequency stage, the sweep frequency signal is kept in the holding stage, the pulse width modulation driving circuit controls the light-emitting unit to be in a non-light-emitting state at the moment, and the output of the sweep frequency stage of closing the sweep frequency signal in the sub-stage to the pulse width modulation driving circuit is realized.
With continued reference to fig. 9, the pwm driving circuit may also input the emission control signal EM. Fig. 10 is a schematic structural diagram of another display panel according to an embodiment of the present invention. As shown in fig. 10, the pixel driving circuit further includes a light-emitting control switch tube T2, the light-emitting control switch tube T2 is connected between a power voltage VDD and the light-emitting unit 20, and a control electrode of the light-emitting control switch tube T2 inputs a light-emitting control signal EM for controlling on/off of the light-emitting control switch tube T2, so as to control a connection state between the power voltage VDD and the light-emitting unit 20, and further control a time for the pixel driving circuit to provide a driving current for the light-emitting unit 20. When the frequency sweep stage of the frequency sweep signal needs to be closed, the level output by the light-emitting control signal EM can be controlled at the sub-stage to control the light-emitting control switch tube T2 to be in a turn-off state, so that the light-emitting unit can be controlled to be in a non-light-emitting state, the light-emitting time of the light-emitting unit is adjusted, and the brightness of the whole screen of the display panel is adjusted. Exemplarily, fig. 10 illustrates that the light emission control switch transistor T2 is a P-type transistor. When the sweep frequency phase of the sweep frequency signal needs to be turned off, the emission control signal EM can be controlled to output a high level in the sub-phase, so that the emission control switch tube T2 is in an off state.
It should be noted that, in other embodiments, the emission control switch tube T2 may also be an N-type transistor, and when the frequency sweep stage of the frequency sweep signal needs to be turned off, the emission control signal EM may also be controlled to output a low level in the sub-stage, so that the emission control switch tube T2 is in an off state.
On the basis of the above technical solutions, in at least one sub-stage, providing a frequency sweep signal to a pwm driving circuit includes:
at least two sub-phases periodically provide the sweep frequency signal to the PWM driving circuit in different frames of the display panel.
When each sub-stage outputs the sweep frequency signal to the pwm driving circuit, the sweep frequency signals output by at least two sub-stages are the same in different frames of the display panel, that is, each sub-stage outputs the sweep frequency signal in different frames of the display panel, so that the sub-stages periodically provide the sweep frequency signal to the pwm driving circuit in different frames of the display panel. The sweep frequency signal can be periodically output frame by frame, which is beneficial to equally dividing the light-emitting time of the display panel in a period and further improving the screen splash phenomenon of the display panel. When the sweep frequency signal is output to the pulse width modulation driving circuit by part of the sub-stages, the sweep frequency signal is periodically and alternately output to the pulse width modulation driving circuit by part of the sub-stages in different frames of the display panel, so that the light emitting time of the display panel is equally divided in one period, and the screen flash phenomenon of the display panel is further improved.
Illustratively, when the lighting phase includes 4 sub-phases, the 4 sub-phases may be implemented by 4 frames to periodically provide the frequency sweep signal to the pwm driving circuit. Fig. 11 is a schematic timing diagram of a first frame of a display panel according to an embodiment of the present invention, fig. 12 is a schematic timing diagram of a second frame of a display panel according to an embodiment of the present invention, fig. 13 is a schematic timing diagram of a third frame of a display panel according to an embodiment of the present invention, and fig. 14 is a schematic timing diagram of a fourth frame of a display panel according to an embodiment of the present invention. As shown in fig. 11 to 14, there are 3 sub-stages outputting the sweep frequency signal to the pwm driving circuit, and 1 sub-stage turning off the sweep frequency signal to the pwm driving circuit. Then, during the first frame, the 1 st to 3 rd sub-stages output the sweep frequency signal to the pwm driving circuit, and the 4 th sub-stage turns off the sweep frequency signal to the pwm driving circuit. And in the second frame, the 1 st, the 2 nd and the 4 th sub-stages output the sweep frequency signals to the pulse width modulation driving circuit, and the 3 rd sub-stage closes the sweep frequency signals and outputs the sweep frequency signals to the pulse width modulation driving circuit. And in the third frame, the 1 st, the 3 rd and the 4 th sub-stages output sweep frequency signals to the pulse width modulation driving circuit, and the 2 nd sub-stage closes the sweep frequency signals and outputs the sweep frequency signals to the pulse width modulation driving circuit. And in the fourth frame, the 2 nd, the 3 rd and the 4 th sub-stages output the sweep frequency signals to the pulse width modulation driving circuit, and the 1 st sub-stage closes the sweep frequency signals and outputs the sweep frequency signals to the pulse width modulation driving circuit. Therefore, the sweep frequency signals can be periodically provided to the pulse width modulation driving circuit in at least two sub-stages in different frames of the display panel, the light emitting time of the display panel can be equally divided in one period, and the screen flashing phenomenon of the display panel can be further improved.
It should be noted that fig. 11 to 14 exemplarily show that the sweep frequency signals of 3 sub-phases are output in each frame. In other embodiments, 1 or 2 sub-phases of the sweep frequency signal may be output in each frame, and at this time, 4 sub-phases of different frames may also be set to periodically provide the sweep frequency signal to the pwm driving circuit, which is not limited herein. In addition, fig. 11 to 14 exemplarily show that after the lighting phase is divided into at least two sub-phases, the duration of the hold phase of the sweep signal is increased in each sub-phase. In other embodiments, after the light emitting phase is divided into at least two sub-phases, whether to provide the sweep frequency signal to the pwm driving circuit in each sub-phase is directly set according to the periodicity, which is not limited herein. Illustratively, when the lighting phase includes 4 sub-phases, the 4 sub-phases may be implemented by 4 frames to periodically provide the frequency sweep signal to the pwm driving circuit. Fig. 15 is a schematic timing diagram of a first frame of a display panel according to another embodiment of the present invention, fig. 16 is a schematic timing diagram of a second frame of a display panel according to another embodiment of the present invention, fig. 17 is a schematic timing diagram of a third frame of a display panel according to another embodiment of the present invention, and fig. 18 is a schematic timing diagram of a fourth frame of a display panel according to another embodiment of the present invention. As shown in fig. 15 to 18, unlike fig. 11 to 14, the duration of the hold phase of the sweep signal in the ith sub-phase in each frame is not increased. Wherein i is an integer greater than or equal to 2.
On the basis of the technical schemes, the frequency sweeping signal comprises a frequency sweeping stage; the level of the sweep frequency signal in the sweep frequency stage changes within the range of the data signals corresponding to different gray scales; before providing the sweep frequency signal to the pwm driving circuit in at least one sub-stage, the method further includes:
and adjusting the slope of the sweep frequency signal in the sweep frequency phase.
The slope of the sweep frequency signal in the sweep frequency stage can adjust the change rate of the sweep frequency signal, so that the light emitting time of the light emitting units corresponding to different display gray scales can be adjusted, and the brightness of the whole screen of the display panel can be adjusted. Illustratively, the value of the data signal is determined when the display gray scale of the display panel is determined. When the slope of the sweep frequency signal in the sweep frequency stage is increased, the change rate of the sweep frequency signal is faster, and the time for changing the level of the sweep frequency signal from the holding stage to the data signal is shorter, that is, the light emitting time of the light emitting unit corresponding to the current display gray scale of the display panel is shortened, so that the brightness of the whole screen of the display panel is reduced. When the slope of the frequency sweeping signal in the frequency sweeping stage is smaller, the change rate of the frequency sweeping signal is slower, and the time for the frequency sweeping signal to change from the level of the holding stage to the data signal is longer, that is, the light emitting time of the light emitting unit corresponding to the current display gray scale of the display panel is longer, so that the brightness of the whole screen of the display panel is increased.
Exemplarily, fig. 19 is a schematic signal timing diagram of another display panel according to an embodiment of the present invention. As shown in fig. 19, the lighting phase includes four sub-phases. The difference from fig. 4 is that in each sub-phase, the slope of the sweep frequency signal in the sweep frequency phase is larger than that in fig. 4. The light emitting time of the light emitting unit corresponding to fig. 19 is shorter than that of the light emitting unit corresponding to fig. 4, so that the full screen luminance of the display panel corresponding to fig. 19 is smaller than that of the display panel corresponding to fig. 4.
It should be noted that, in other embodiments, the slope of the sweep phase of the sweep signal in the partial sub-phase may also be adjusted when the sweep signal is provided to the pwm driving circuit in the partial sub-phase. At this time, the number of the sub-stages providing the sweep frequency signal can be controlled to adjust the whole screen brightness of the display panel, and meanwhile, the light emitting time of the light emitting unit in the partial sub-stages can be further adjusted by adjusting the slope of the sweep frequency stage of the sweep frequency signal in the partial sub-stages, so that the whole screen brightness of the display panel can be further adjusted, and the flexibility of adjusting the whole screen brightness of the display panel can be increased. Exemplarily, fig. 20 is a schematic signal timing diagram of another display panel according to an embodiment of the present invention. As shown in fig. 20, the light-emitting phase includes four sub-phases, and the brightness of the entire screen of the display panel can be adjusted to decrease by 50% by setting the first sub-phase and the third sub-phase to output the sweep frequency signal. Meanwhile, different from fig. 5, when the frequency sweep signal is output at the sub-stage, the slope of the frequency sweep signal at the frequency sweep stage is greater than that of the frequency sweep signal at the frequency sweep stage in fig. 5, for example, the slope of the frequency sweep signal at the frequency sweep stage in fig. 5 is 80% of that of the frequency sweep signal at the frequency sweep stage in fig. 20, so that the light emitting time of the light emitting unit is reduced to 80% again on the basis that the brightness of the entire screen of the display panel is reduced by 50%, that is, the brightness of the entire screen of the display panel is reduced to 40%, and thus the brightness of the entire screen of the display panel can be adjusted more flexibly.
Or, in other embodiments, the slope of the frequency sweep signal in the frequency sweep stage may also be adjusted on the basis of increasing the duration of the holding stage of the i-th sub-stage frequency sweep signal when the sub-stage provides the frequency sweep signal to the pwm driving circuit. Exemplarily, fig. 21 is a schematic signal timing diagram of another display panel according to an embodiment of the present invention. As shown in fig. 21, the light-emitting phase includes four sub-phases, and when the second sub-phase to the fourth sub-phase are the same as fig. 6, the duration of the sweep signal holding phase is increased, and the duration of one frame of the display panel is equally divided into a plurality of sub-phases, each of which includes equal non-light-emitting time and light-emitting time, so as to further improve the flicker phenomenon of the display panel. Meanwhile, different from fig. 6, when the sweep frequency signal is output at the sub-stage, the slope of the sweep frequency signal at the sweep frequency stage is greater than that of the sweep frequency signal at the sweep frequency stage in fig. 6, so that the light emitting time of the light emitting unit can be adjusted on the basis of improving the screen splash phenomenon of the display panel, and further the whole screen brightness of the display panel can be adjusted.
In addition, in different sub-stages, the slope of the sweep frequency signal in the sweep frequency stage can be set according to requirements, so that the light emitting time of the light emitting unit can be adjusted more flexibly, and the brightness of the whole screen of the display panel can be adjusted more flexibly.
Preferably, the slopes of the sweep signal during the sweep phase are equal in the different sub-phases.
Specifically, the slopes of the sweep frequency signals in the sweep frequency stage are set to be equal in different sub-stages, so that the change rates of the sweep frequency signals in the sweep frequency stage in different sub-stages are the same, that is, the light emitting time of the light emitting units corresponding to different display gray scales is the same, and therefore, the light emitting time of the light emitting unit in any sub-stage is proportional to the whole-screen brightness of the display panel, and the adjustment of the whole-screen brightness of the display panel is facilitated.
The embodiment of the invention also provides a display panel. Fig. 22 is a schematic structural diagram of another display panel according to an embodiment of the disclosure. As shown in fig. 22, the display panel includes a driving unit 30, a pulse width modulation driving circuit 10, and a light emitting unit 20; the pulse width modulation driving circuit 10 is connected to the light emitting unit 20; one frame time of the display panel comprises a data writing stage and a light-emitting stage, wherein the light-emitting stage comprises at least two sub-stages; the driving unit 30 is connected to the pwm driving circuit 10, and the driving unit 30 is configured to provide a data signal to the pwm driving circuit 10 during a data writing phase and provide a sweep signal to the pwm driving circuit 10 during at least one sub-phase, so that the pwm driving circuit 10 controls the light emitting time of the light emitting unit 20 according to the data signal and the sweep signal; each sub-stage for providing the frequency sweeping signal corresponds to a frequency sweeping signal.
According to the technical scheme of the embodiment of the invention, the lighting phase comprises at least two sub-phases, each sub-phase for providing the frequency sweep signal corresponds to a frequency sweep signal, at least one sub-phase, the driving unit provides the frequency sweep signal to the pulse width modulation driving circuit, so that the pulse width modulation driving circuit controls the lighting time of the lighting unit according to the data signal and the frequency sweep signal, the lighting time of the lighting unit can be divided into different sub-phases, under the condition that the lighting time of the lighting unit occupies one frame of time, the non-lighting time of the display panel in each sub-phase can be reduced, the degree of the reduction of the lighting brightness of the display panel can be reduced, meanwhile, the switching frequency of the lighting brightness of the display panel can be multiplied within one frame of time, the flash frequency of the display panel can be further multiplied, the flash frequency of the display panel is favorable for exceeding the sensing range of human eyes, and the flash phenomenon of the display panel when displaying low gray scale can be improved. Moreover, the number of the sub-stages for providing the sweep frequency signal is controlled by the driving unit, so that the light emitting time of the light emitting unit can be integrally adjusted when the data voltage is unchanged, namely the proportion of the light emitting time of the light emitting unit in each sub-stage is unchanged, and the whole screen brightness of the display panel can be integrally adjusted.
With continued reference to fig. 22, the driving unit 30 includes a data signal generating module 31, a sweep signal generating module 32, and a switching module 33; the data signal generating module 31 is connected to a first input end of the switching module 33, the data signal generating module 31 is configured to provide a data signal, the sweep frequency signal generating module 32 is connected to a second input end of the switching module 33, the sweep frequency signal generating module 32 is configured to provide a sweep frequency signal, an output end of the switching module 33 is connected to the pwm driving circuit 10, and the switching module 33 is configured to switch the data signal generating module 31 or the sweep frequency signal generating module 32 to be communicated with the pwm driving circuit 10.
Specifically, in the data writing phase, the switching module 33 may connect the first input terminal and the output terminal, so that the data signal generating module 31 is connected to the pwm driving circuit 10, and at this time, the data signal provided by the data signal generating module 31 is transmitted to the pwm driving circuit 10 through the switching module 33, so as to provide the data signal to the pwm driving circuit 10. In at least one sub-stage, the switching module 33 may communicate the second input end with the output end, so that the sweep frequency signal generating module 32 is connected to the pwm driving circuit 10, and at this time, the sweep frequency signal provided by the sweep frequency signal generating module 32 is transmitted to the pwm driving circuit 10 through the switching module 33, so as to provide the sweep frequency signal to the pwm driving circuit 10. The pwm driving circuit 10 then controls the light emission time of the light emitting unit based on the data signal and the sweep signal.
With continued reference to fig. 22, preferably, the switch module 33 includes a switch K1, a first end of the switch K1 is connected to the data signal generating module 31, a second end of the switch K1 is connected to the sweep signal generating module 32, and an output end of the switch K1 is connected to the pwm driving circuit 10.
Specifically, fig. 22 exemplarily shows that the switch module 33 includes a switch K1, and the switch K1 is communicated with the output terminal by switching a first terminal or a second terminal, so that the data signal provided by the data signal generating module 31 can be transmitted to the pwm driving circuit 10 in the data writing phase, and the sweep signal provided by the sweep signal generating module 32 can be transmitted to the pwm driving circuit 10 in at least one sub-phase. The driving unit 30 may further include a control module (not shown in fig. 22), and the switching action of the switch K1 may be controlled by the control module according to the scanning signal. For example, at the end of the data writing phase, the scan signal has a transition edge, and the control module controls the switch K1 to perform a switching operation according to the transition edge of the scan signal.
On the basis of the technical schemes, when at least two sub-stages are sequentially sequenced after the data writing stage; the sweep frequency signal comprises a holding stage, and when the level of the sweep frequency signal in the holding stage is positioned outside the range of the data signals corresponding to different gray scales; the drive unit further includes:
the increasing module is used for increasing the duration of the holding stage of the ith sub-stage frequency sweeping signal; wherein the duration of the increase is equal to the duration of the data writing phase, and i is an integer greater than or equal to 2.
Optionally, the adding module is specifically configured to insert a long-duration level signal in a data writing stage at a holding stage of the sweep signal; the level signal is located outside the range of the data signal corresponding to different gray scales, and the level signal with at least partial duration is unchanged.
On the basis of the technical schemes, when the frequency sweeping signal comprises a frequency sweeping stage; when the level of the sweep frequency signal at the sweep frequency stage changes within the range of the data signals corresponding to different gray scales; the drive unit is specifically configured to:
in a partial sub-stage, the frequency sweeping stage of the trigger frequency sweeping signal is output to the pulse width modulation driving circuit, so that the pulse width modulation driving circuit controls the light emitting time of the light emitting unit according to the data signal and the frequency sweeping signal;
in a partial sub-stage, the output of the sweep frequency stage of the sweep frequency signal to the pulse width modulation driving circuit is closed; the sub-stage of the output of the frequency sweep stage for triggering the frequency sweep signal and the sub-stage of the output of the frequency sweep stage for closing the frequency sweep signal are regularly arranged.
On the basis of the technical scheme, when the frequency sweeping signal further comprises a holding stage, and the level of the frequency sweeping signal in the holding stage is positioned outside the range of the data signals corresponding to different gray scales; when the driving unit is used for closing the sweep frequency phase output of the sweep frequency signal to the pulse width modulation driving circuit in a partial sub-phase, the driving unit specifically comprises:
and in a partial sub-stage, controlling the level of the sweep frequency signal in the sweep frequency stage to output to the pulse width modulation driving circuit.
On the basis of the above technical solutions, the driving unit is further configured to:
at least two sub-stages periodically provide the sweep frequency signal to the PWM driving circuit in different frames of the display panel.
On the basis of the technical schemes, when the frequency sweeping signal comprises a frequency sweeping stage; when the level of the sweep frequency signal at the sweep frequency stage changes within the range of the data signal corresponding to different gray scales, the driving unit is further configured to:
and adjusting the slope of the sweep frequency signal in the sweep frequency phase.
Preferably, the slopes of the sweep signal during the sweep phase are equal in the different sub-phases.
The embodiment of the invention also provides a display device. Fig. 23 is a schematic structural diagram of a display device according to an embodiment of the present invention. As shown in fig. 23, the display device 100 includes a display panel 101 provided in any embodiment of the present invention.
It is to be noted that the foregoing description is only exemplary of the invention and that the principles of the technology may be employed. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments described herein, but is capable of various obvious changes, rearrangements and substitutions as will now become apparent to those skilled in the art without departing from the scope of the invention. Therefore, although the present invention has been described in some detail by the above embodiments, the invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the spirit of the invention, and the scope of the invention is determined by the scope of the appended claims.

Claims (10)

1. A driving method of a display panel, the display panel comprises a pulse width modulation driving circuit and a light emitting unit, wherein the pulse width modulation driving circuit is connected with the light emitting unit; one frame time of the display panel comprises a data writing phase and a light-emitting phase, wherein the light-emitting phase comprises at least two sub-phases; the driving method of the display panel is characterized by comprising the following steps:
in the data writing stage, providing a data signal to the pulse width modulation driving circuit;
providing a sweep frequency signal to the PWM driving circuit at least at one sub-stage, so that the PWM driving circuit controls the light emitting time of the light emitting unit according to the data signal and the sweep frequency signal; wherein each sub-stage providing a sweep signal corresponds to one sweep signal.
2. The method according to claim 1, wherein the sweep signal comprises a hold phase, and a level of the sweep signal in the hold phase is outside a range of data signals corresponding to different gray scales; before providing the sweep frequency signal to the pwm driving circuit in at least one of the sub-stages, the method further includes:
increasing the duration of the holding stage of the sweep frequency signal in the ith sub-stage; wherein the increased duration is equal to the duration of the data writing phase, and i is an integer greater than or equal to 2.
3. The method for driving a display panel according to claim 2, wherein increasing the duration of the hold phase of the swept frequency signal in the ith sub-phase comprises:
inserting a level signal of the duration of the data writing stage in the holding stage of the sweep frequency signal; the level signal is located outside the range of the data signal corresponding to different gray scales, and the level signal with at least partial duration is unchanged.
4. The driving method of a display panel according to any one of claims 1 to 3, wherein the sweep signal includes a sweep phase; the level of the frequency sweeping signal in the frequency sweeping stage changes within the range of data signals corresponding to different gray scales; providing a swept frequency signal to the pwm driver circuit during at least one of the sub-phases, comprising:
in part of the sub-stages, triggering the sweep frequency stage of the sweep frequency signal to output to the pulse width modulation driving circuit, so that the pulse width modulation driving circuit controls the light emitting time of the light emitting unit according to the data signal and the sweep frequency signal;
in part of the sub-stages, the output of the sweep frequency stage of the sweep frequency signal to the pulse width modulation driving circuit is closed; and the sub-stage for triggering the output of the frequency sweeping stage of the frequency sweeping signal and the sub-stage for closing the output of the frequency sweeping stage of the frequency sweeping signal are regularly arranged.
5. The method according to claim 4, wherein the sweep signal further comprises a hold stage, and the level of the sweep signal in the hold stage is outside the range of the data signals corresponding to different gray scales; in part of the sub-stages, turning off the output of the sweep frequency stage of the sweep frequency signal to the pwm driving circuit includes:
and in part of the sub-stages, controlling the sweep frequency signal to output the level of the holding stage to the pulse width modulation driving circuit in the sweep frequency stage.
6. The method for driving a display panel according to any one of claims 1-5, wherein providing a frequency sweep signal to the PWM driving circuit during at least one of the sub-phases comprises:
at least two of the sub-stages periodically provide the swept frequency signal to the PWM driving circuit within different frames of the display panel.
7. The driving method of a display panel according to any one of claims 1 to 6, wherein the sweep signal includes a sweep phase; the level of the frequency sweeping signal in the frequency sweeping stage changes within the range of data signals corresponding to different gray scales; before providing the sweep frequency signal to the pwm driving circuit in at least one of the sub-stages, the method further includes:
adjusting the slope of the sweep frequency signal in the sweep frequency phase;
preferably, the slopes of the sweep signals in the sweep phase in different sub-phases are equal.
8. A display panel is characterized by comprising a driving unit, a pulse width modulation driving circuit and a light emitting unit;
the pulse width modulation driving circuit is connected with the light-emitting unit; one frame time of the display panel comprises a data writing phase and a light-emitting phase, wherein the light-emitting phase comprises at least two sub-phases; the driving unit is connected with the pwm driving circuit, and the driving unit is configured to provide a data signal to the pwm driving circuit in the data writing stage and provide a sweep signal to the pwm driving circuit in at least one of the sub-stages, so that the pwm driving circuit controls the light emitting time of the light emitting unit according to the data signal and the sweep signal; wherein each sub-stage providing a sweep signal corresponds to one sweep signal.
9. The display panel according to claim 8, wherein the driving unit comprises a data signal generation module, a sweep signal generation module, and a switching module;
the data signal generating module is connected with a first input end of the switching module, the data signal generating module is used for providing the data signal, the sweep frequency signal generating module is connected with a second input end of the switching module, the sweep frequency signal generating module is used for providing the sweep frequency signal, an output end of the switching module is connected with the pulse width modulation driving circuit, and the switching module is used for switching the data signal generating module or the sweep frequency signal generating module to be communicated with the pulse width modulation driving circuit;
preferably, the switching module includes a switch, a first end of the switch is connected to the data signal generating module, a second end of the switch is connected to the swept frequency signal generating module, and an output end of the switch is connected to the pwm driving circuit.
10. A display device characterized by comprising the display panel according to any one of claims 8 to 9.
CN202210946196.8A 2022-08-08 2022-08-08 Display panel, driving method of display panel and display device Pending CN115881026A (en)

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