Display panel and display device

Abstract

The embodiment of the invention provides a display panel and a display device. The display panel comprises a pixel circuit and a light-emitting device. The pixel circuit comprises a pulse width modulation module, and the pulse width modulation module is configured to modulate the light-emitting duration of a light-emitting device based on a pulse width modulation data voltage and a sweep frequency signal. The working modes of the display panel comprise a first mode and a second mode, and the brightness of the display panel in the first mode is smaller than that of the display panel in the second mode; the pulse width modulation module receives a first sweep frequency signal in a first mode, the pulse width modulation module receives a second sweep frequency signal in a second mode, and the first sweep frequency signal is different from the second sweep frequency signal. The display panel receives different frequency sweeping signals in the first mode and the second mode, and the duration of the pixel circuit transmitting the driving current to the light emitting device is related to the frequency sweeping signals, so that the pulse width modulation data voltage received by the display panel in the first mode and the second mode has an adjustable space. The brightness resolution in a low-brightness mode can be improved.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display panel and a display device. Background Art

[0002] In a display panel, the driving methods used by the pixel circuit to drive the pixel to emit light include pulse width modulation (PWM) and / or amplitude modulation (PAM). Pulse width modulation can control the duration of the pixel circuit sending the driving current to the light-emitting device in the pixel so that the light-emitting device presents a corresponding brightness. Pulse width modulation controls the duration of the light-emitting device receiving the driving current based on the different pulse width modulation data voltages. However, when the display panel is in low brightness mode, the maximum pulse width modulation data voltage that the display panel can receive is low. In other words, the range of pulse width modulation data voltages that can be adjusted when the light-emitting device in the display panel displays multiple grayscales in low brightness mode is limited, resulting in difficulty in distinguishing the brightness difference of the pixel when displaying adjacent grayscales. Summary of the Invention

[0003] In view of this, embodiments of the present application provide a display panel and a display device to solve the above problems.

[0004] In a first aspect, an embodiment of the present application provides a display panel comprising a pixel circuit and a light-emitting device; wherein the pixel circuit comprises a pulse width modulation module, and the pulse width modulation module is configured to modulate the light-emitting duration of the light-emitting device based on a pulse width modulation data voltage and a sweep signal; the operating modes of the display panel include a first mode and a second mode, the brightness of the display panel in the first mode is L1, and the brightness of the display panel in the second mode is L2, L1<L2; the sweep signal received by the pulse width modulation module in the first mode is a first sweep signal, and the sweep signal received by the pulse width modulation module in the second mode is a second sweep signal, and the first sweep signal is different from the second sweep signal.

[0005] In a second aspect, an embodiment of the present application provides a display device, comprising the display panel provided in the first aspect.

[0006] In the technical solution provided by the embodiments of the present application, the display panel receives different sweep frequency signals in the first and second modes, respectively. The duration during which the pixel circuit transmits a driving current to the light-emitting device in the first mode and the second mode can be modulated not only by the pulse-width modulated data voltage but also by the sweep frequency signal. Accordingly, the pulse-width modulated data voltage received by the display panel in the first and second modes is adjustable. For example, the pulse-width modulated data voltage value in the first mode, corresponding to the low-brightness mode, can be increased, thereby improving the brightness resolution in the low-brightness mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0008] Figure 1 A schematic diagram of a display panel provided in an embodiment of the present application;

[0009] Figure 2 A timing diagram of a display panel provided in an embodiment of the present application;

[0010] Figure 3 A schematic diagram of a pixel circuit related to an embodiment of the present application;

[0011] Figure 4 A schematic diagram of a pixel circuit related to an embodiment of the present application

[0012] Figure 5 for Figure 3 An operating timing diagram of the pixel circuit shown;

[0013] Figure 6 for Figure 4 An operating timing diagram of the pixel circuit shown;

[0014] Figure 7 A timing diagram of some signals in a display panel provided in an embodiment of the present application;

[0015] Figure 8 A timing diagram of some signals in a display panel provided in an embodiment of the present application;

[0016] Figure 9 A timing diagram of some signals in a display panel provided in an embodiment of the present application;

[0017] Figure 10 A timing diagram of some signals in a display panel provided in an embodiment of the present application;

[0018] Figure 11 A timing diagram of some signals in a display panel provided in an embodiment of the present application;

[0019] Figure 12 A schematic diagram of the correspondence between a sweep frequency signal and a brightness segment in a display panel provided in an embodiment of the present application;

[0020] Figure 13 A schematic diagram of the correspondence between a sweep frequency signal and a brightness segment in a display panel provided in an embodiment of the present application;

[0021] Figure 14A schematic diagram of the correspondence between a gamma curve and brightness segments in a display panel provided in an embodiment of the present application;

[0022] Figure 15 A timing diagram of some signals in a display panel provided in an embodiment of the present application;

[0023] Figure 16 A schematic diagram of a display panel provided in an embodiment of the present application;

[0024] Figure 17 A schematic diagram of a display device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0026] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0027] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0028] It should be understood that the term "and / or" as used herein is merely a description of the relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, or B exists alone. Furthermore, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0029] In the description of this specification, it is necessary to understand that the words "substantially", "approximately", "approximately", "about", "roughly", "substantially" and the like described in the claims and embodiments of this application refer to what can be generally recognized within a reasonable process operation range or tolerance range, rather than an exact value.

[0030] It should be understood that although the terms "first", "second", etc. may be used to describe modes, brightness ranges, etc. in the embodiments of the present application, these should not be limited to these terms. These terms are only used to distinguish modes, brightness ranges, etc. from each other. For example, without departing from the scope of the embodiments of the present application, the first mode may also be referred to as the second mode, and similarly, the second mode may also be referred to as the first mode. The applicant of this case has provided a solution to the problems existing in the prior art through careful and in-depth research.

[0031] Figure 1 A schematic diagram of a display panel provided in an embodiment of the present application is shown. Figure 2 A timing diagram of a display panel provided in an embodiment of the present application.

[0032] like Figure 1 As shown, an embodiment of the present application provides a display panel 01, including a pixel circuit 10 and a light-emitting device 20. The pixel circuit 10 is electrically connected to the light-emitting device 20 and can drive the light-emitting device 20 to emit light. The light-emitting device 20 can be at least one of an organic light-emitting diode (OLED), a sub-millimeter light-emitting diode (Mini-LED), and a micro light-emitting diode (Micro-LED).

[0033] Combine Figure 1 and Figure 2 The pixel circuit 10 includes a pulse width modulation module 11. The pulse width modulation module 11 is configured to modulate the light emission duration of the light-emitting device 20 based on the pulse width modulation data voltage PWM_Data and the sweep signal SWEEP. For example, the pixel circuit 10 can transmit a driving current to the light-emitting device 20 to drive the light-emitting device 20 to emit light. The pulse width modulation module 11 is used to control the duration of the driving current transmitted by the pixel circuit 10 to the light-emitting device 20. This duration can vary based on the pulse width modulation data voltage PWM_Data and the sweep signal SWEEP. For ease of understanding, the following description uses the example of the pixel circuit 10 transmitting the driving current to the light-emitting device 20.

[0034] The operating modes of the display panel 01 may include a first mode D1 and a second mode D2. Different operating modes of the display panel 01 may result in different brightnesses of the display panel 01. The brightness of the display panel 01 in the first mode D1 is L1, and the brightness of the display panel 01 in the second mode D2 is L2, where L1 < L2. The brightness of the display panel 01 in the first mode D1 may be understood as the overall brightness of the display panel 01 in the first mode D1; the brightness of the display panel 01 in the second mode D2 may be understood as the overall brightness of the display panel 01 in the second mode D2. That is, the overall brightness of the display panel 01 when performing a light-emitting display in the first mode D1 is greater than the overall brightness of the display panel 01 when performing a light-emitting display in the first mode D1. In other words, the maximum brightness value of the display panel 01 when displaying the highest grayscale in the first mode D1 is B1, and the maximum brightness value when displaying the highest grayscale in the second mode D2 is B2, where B1 < B2. Taking the grayscale bit number of the display panel 01 as 8 bits as an example, the brightness that can be presented by the light-emitting device 20 in the display panel 01 can be divided into 256 grayscales from 0 to 255. Then, when the display panel 01 displays 0 to 255 grayscales in the first mode D1, the brightness value presented is smaller than the brightness value presented when the display panel 01 displays 0 to 255 grayscales in the second mode D2, and the brightness value of the light-emitting device 20 in the display panel 01 when presenting 255 grayscales in the first mode D1 is smaller than the brightness value when presenting 255 grayscales in the second mode D2.

[0035] In the embodiment of the present application, the brightness of the light-emitting device 20 is controlled by at least varying the duration for which the pixel circuit 10 transmits a driving current to the light-emitting device 20. Generally, the brightness of the light-emitting device 20 is positively correlated with the duration for which it receives the driving current. Thus, the longer the duration for which the pixel circuit 10 transmits the driving current to the light-emitting device 20, the higher the brightness of the light-emitting device 20; and the shorter the duration for which the pixel circuit 10 transmits the driving current to the light-emitting device 20, the lower the brightness of the light-emitting device 20.

[0036] Then, in the first mode D1, the preset duration for the light-emitting device 20 in the display panel 01 to receive the driving current can be between 0 and t1, that is, the maximum duration for the light-emitting device 20 to receive the driving current when the display panel 01 is in the first mode D1 is t1 and the maximum brightness value presented by the light-emitting device 20 at this time corresponds to the maximum grayscale value (for example, corresponding to 255 grayscale). In the second mode D2, the preset duration for the light-emitting device 20 in the display panel 01 to receive the driving current can be between 0 and t2, that is, the maximum duration for the light-emitting device 20 to receive the driving current when the display panel 01 is in the second mode D2 is t2 and the maximum brightness value presented by the light-emitting device 20 at this time corresponds to the maximum grayscale value (for example, corresponding to 255 grayscale). By controlling t1 to be less than t2, the maximum brightness value of the light-emitting device 20 in the display panel 01 in the first mode D1 is less than the maximum brightness value in the second mode D2.

[0037] The display panel 01 typically includes multiple brightness-related operating modes to adapt to different application scenarios. Exemplarily, the operating mode of the display panel 01 can automatically switch when the ambient light changes. Specifically, the operating mode of the display panel 01 when the ambient light is relatively strong is different from the operating mode when the ambient light is relatively weak. For example, one operating mode of the display panel 01 when the ambient light is relatively weak is the first mode D1, and the maximum brightness value that can be displayed is B1. Another operating mode of the display panel 01 when the ambient light is relatively strong is the second mode D2, and the maximum brightness value that can be displayed is B2, where B1 < B2. Exemplarily, the operating mode of the display panel 01 can automatically switch when the battery level changes. Specifically, the operating mode of the display panel 01 when the battery level is above a power threshold is different from the operating mode when the battery level is below the power threshold. For example, one operating mode of the display panel 01 when the battery level is below the power threshold is the first mode D1, and the maximum brightness value that can be displayed is B1. Another operating mode of the display panel 01 when the battery level is above the power threshold is the second mode D2, and the maximum brightness value that can be displayed is B2, where B1 < B2. Exemplarily, the display panel 01 can also switch the working mode in response to the user's operation. For example, the display panel 01 switches to the corresponding working mode in response to the user's adjustment of the brightness bar in the operation interface. When the user adjusts the brightness bar from the lower position to the upper position, the display panel 01 can switch from the first mode D1 to the second mode D2, and the maximum brightness value that the display panel 01 can display can change from B1 to B2, B1<B2; for example, the display panel 01 switches to the corresponding working mode in response to the user's selection of the energy-saving mode. When the user turns on the energy-saving mode, the corresponding working mode is the first mode D1 and the maximum brightness value that can be displayed is B1. When the user turns off the energy-saving mode, the corresponding working mode is the second mode D2 and the maximum brightness value that can be displayed is B2, B1>B2.

[0038] It should be noted that the above examples are used to illustrate the working modes of the display panel 01, especially the first mode D1 and the second mode D2, but the working modes mentioned in this embodiment are not limited to the above modes. In addition, the working modes of the display panel 01 mentioned in the embodiment of the present application include the first mode D1 and the second mode D2, which do not simply refer to the two working modes of the display panel 01, but use the first mode D1 and the second mode D2 to represent different working modes of the display panel 01, and in different modes, the display panel 01 will have different brightness. For the convenience of description, this embodiment mainly takes the example that the working mode of the display panel 01 includes two modes (the first mode D1 and the second mode D2) and the first mode D1 corresponds to the low brightness mode and the second mode D2 corresponds to the high brightness mode, to exemplify the technical solution of the embodiment of the present application.

[0039] Assuming that the duration of the driving current received by the light-emitting device 20 in the display panel 01 is determined solely by the data voltage, since the data voltage range that the display panel 01 can receive is limited, the lower the brightness corresponding to the operating mode of the display panel 01, the narrower the range of the pulse-width modulation data voltage PWM_Data that it can receive when displaying a grayscale of 0-255. For example, the range of the pulse-width modulation data voltage PWM_Data that the display panel 01 can receive when displaying a grayscale of 0-255 in the first mode D1 is 0V-2V, and the range of the pulse-width modulation data voltage PWM_Data that the display panel 01 can receive when displaying a grayscale of 0-255 in the second mode D2 is 0-5V. It can be seen that the difference in the pulse-width modulation data voltage PWM_Data required for the display panel 01 to display similar grayscales in the low-brightness mode is small. Therefore, the resolution of the pulse-width modulation data voltage PWM_Data of the display panel 01 in the low-brightness mode is low.

[0040] In addition, since there is actual loss in the pulse width modulation data voltage PWM_Data and the loss ratio in low brightness mode is greater than that in high brightness mode, the difference in the pulse width modulation data voltage PWM_Data actually received by the display panel 01 when displaying similar grayscales in low brightness mode is smaller, which makes the brightness resolution of the display panel 01 in low brightness mode significantly lower than the brightness resolution in high brightness mode.

[0041] In the display panel 01 provided in the embodiment of the present application, Figure 2As shown, the sweep signal SWEEP received by the pulse width modulation module 11 in the first mode D1 is the first sweep signal SWEEP1, and the sweep signal SWEEP received by the pulse width modulation module 11 in the second mode D2 is the second sweep signal SWEEP2. The first sweep signal SWEEP1 and the second sweep signal SWEEP2 are different. That is, the sweep signal SWEEP received by the display panel 01 in low brightness mode is different from that in high brightness mode. Therefore, when the light-emitting device 20 presents the same grayscale in low brightness mode and in high brightness mode, the pulse width modulation data voltage PWM_Data and the sweep signal SWEEP received by the pixel circuit 10 electrically connected thereto in low brightness mode are different from those received in high brightness mode.

[0042] Furthermore, when the display panel 01 is in the same operating mode, the pixel circuit 10 can receive different pulse-width modulation data voltages PWM_Data and the same sweep signal SWEEP to control the duration for which the pixel circuit 10 transmits a driving current to the light-emitting device 20. For example, when the display panel 01 is in the first mode D1, the pixel circuit 10 can receive the first pulse-width modulation data voltage PWM_Data1 and the second pulse-width modulation data voltage PWM_Data2, respectively, to control the light-emitting device 20 to receive the driving current for different durations in the first mode D1. When the display panel 01 is in the second mode D2, the pixel circuit 10 can receive the third pulse-width modulation data voltage PWM_Data3 and the fourth pulse-width modulation data voltage PWM_Data4, respectively, to control the light-emitting device 20 to receive the driving current for different durations in the second mode D2.

[0043] The first sweep signal SWEEP1 can cause the pixel circuit 10 to terminate the transmission of the driving current to the light-emitting device 20 more quickly than the second sweep signal SWEEP2. In this case, the range of the pulse-width modulated data voltage PWM_Data that the display panel 01 can receive in low-brightness mode can be appropriately widened. For example, when the display panel 01 displays grayscales 0-255 in the first mode D1, the range of the pulse-width modulated data voltage PWM_Data that the display panel 01 can receive can be widened from 0V-2V to 0V-3V. Correspondingly, except for grayscale 0, the pulse-width modulated data voltage PWM_Data corresponding to grayscales displayed by the display panel 01 in low-brightness mode becomes larger, and the difference in the pulse-width modulated data voltage PWM_Data actually received by the display panel 01 when displaying similar grayscales in low-brightness mode becomes larger. Furthermore, because the first sweep signal SWEEP1 can cause the pixel circuit 10 to terminate the transmission of the driving current to the light-emitting device 20 more quickly, the duration that the pixel circuit 10 outputs the driving current to the light-emitting device 20 in the first mode D1 can remain substantially between 0 and t1. Therefore, the brightness resolution of the display panel 01 provided in the embodiment of the present application is improved in the low brightness mode.

[0044] Figure 3 is a schematic diagram of a pixel circuit related to an embodiment of the present application, Figure 4 is a schematic diagram of a pixel circuit related to an embodiment of the present application, Figure 5 for Figure 3 A working timing diagram of the pixel circuit shown in FIG. Figure 6 for Figure 4 A working timing diagram of the pixel circuit shown.

[0045] like Figure 3 and Figure 4 As shown, the pixel circuit 10 also includes an amplitude modulation module 12, which is configured to modulate the amplitude of the driving current received by the light-emitting device 20 based on the amplitude modulation data voltage. In some light-emitting devices 20, such as OLED, Micro-LED, Mini-LED, etc., their luminous characteristics will change due to the change in the amplitude of the received driving current. In order to avoid this problem, a combination of pulse width modulation drive and amplitude modulation drive can be used to reduce the frequency of amplitude change of the driving current or eliminate the amplitude change of the driving current. Therefore, the output end of the pulse width modulation module 11 in the pixel circuit 10 is electrically connected to the amplitude modulation module 12, wherein the amplitude modulation module 12 can output the driving current to the light-emitting device 20 and the pulse width modulation module 11 can control the duration of the amplitude modulation module 12 outputting the driving current to the light-emitting device 20.

[0046] Please continue to refer to Figure 3 and Figure 4The amplitude modulation module 12 includes a first drive transistor M1 and a first control transistor M15. The first drive transistor M1 is configured to generate a drive current of corresponding amplitude based on the amplitude modulation data voltage PAM_Data. The first control transistor M15 is configured to control the first drive transistor M1 to output the drive current based on a first control signal. When the first control signal received by the first control transistor M15 is at an active level, the first control transistor M15 is turned on, and the first drive transistor M1 is able to generate and transmit the drive current to the light-emitting device 20. When the first control signal received by the first control transistor M15 is at an inactive level, the first control transistor M15 is turned off, and no signal is transmitted between the first drive transistor M1 and the light-emitting device 20.

[0047] For example, Figure 3 As shown, the amplitude modulation module 12 also includes a first data write transistor M11, a first threshold grabbing transistor M12, a first power supply voltage write transistor M14, a first reset transistor M13, a second reset transistor M16, and a first capacitor C1. The first data write transistor M11 has a first electrode for receiving the amplitude modulated data voltage PAM_Data, a second electrode electrically connected to the first electrode of the first drive transistor M1, and a gate electrically connected to the first scan line PAM_S2. The first threshold grabbing transistor M12 has a first electrode electrically connected to the second electrode of the first drive transistor M1, a second electrode electrically connected to the gate of the first drive transistor M1, and a gate electrically connected to the first scan line PAM_S2. The first power supply voltage write transistor M14 has a first electrode for receiving the first power supply voltage PVDD, a second electrode electrically connected to the first electrode of the first drive transistor M1, and a gate electrically connected to the second scan line PAM_EM. The first control transistor M15 has a first electrode electrically connected to the first electrode of the first drive transistor M1, a second electrode electrically connected to the anode of the light-emitting device 20, and a gate electrically connected to the second scan line PAM_EM. The second scan line PAM_EM transmits a first control signal to the gate of the first control transistor M15. The first reset transistor M13 has a first electrode electrically connected to the first reset signal PAM_REF, a second electrode electrically connected to the gate of the first drive transistor M1, and a gate electrically connected to the third scan line PAM_S1. The second reset transistor M16 has a first electrode electrically connected to the first reference voltage PVEE, a second electrode electrically connected to the second electrode of the first control transistor M15, and a gate electrically connected to the first scan line PAM_S2. The first plate of the first capacitor C1 receives the first power supply voltage PVDD, and the second plate is electrically connected to the gate of the first drive transistor M1.

[0048] Please refer to Figure 3The pulse width modulation module 11 further includes a second driving transistor M2 and a second control transistor M25. The second driving transistor M2 is configured to be turned on at a corresponding time based on the pulse width modulation data voltage PWM_Data and the sweep signal SWEEP. The second control transistor M25 is configured to be controlled to be turned on based on the second control signal, so that the second driving transistor M2 outputs a shutdown signal to the amplitude modulation module 12. The shutdown signal can cause the amplitude modulation module 12 to stop transmitting the driving current to the light-emitting device 20. When the second control signal received by the first control transistor M15 is at an active level, the second control transistor M25 is turned on, and the second driving transistor M2 outputs a shutdown signal to the amplitude modulation module 12 after being turned on for a corresponding period of time. When the first control signal received by the first control transistor M15 is at an inactive level, the first control transistor M15 is turned off, and the second driving transistor M2 no longer transmits the shutdown signal to the amplitude modulation module 12.

[0049] Please continue to refer to Figure 3 The pulse width modulation module 11 also includes a second data writing transistor M21, a second threshold grabbing transistor M22, a second power supply voltage writing transistor M24, a third reset transistor M23, a fourth reset transistor M26, and a second capacitor C2. The first electrode of the second data writing transistor M21 is used to receive the pulse width modulation data voltage PWM_Data, the second electrode is electrically connected to the first electrode of the second driving transistor M2, and the gate is electrically connected to the fourth scan line PWM_S2. The first electrode of the second threshold grabbing transistor M22 is electrically connected to the second electrode of the second driving transistor M2, the second electrode of the second threshold grabbing transistor M22 is electrically connected to the gate of the second driving transistor M2, and the gate is electrically connected to the fourth scan line PWM_S2. The first electrode of the second power supply voltage PWM_VH writing transistor M24 is used to receive the second power supply voltage PWM_VH, the second electrode is electrically connected to the first electrode of the second driving transistor M2, and the gate is electrically connected to the fifth scan line PWM_EM. The first electrode of the second control transistor M25 is electrically connected to the first electrode of the second drive transistor M2, the second electrode is electrically connected to the gate of the first drive transistor M1, and the gate is electrically connected to the fifth scan line PWM_EM, where the fifth scan line PWM_EM is used to transmit the second control signal. The first electrode of the third reset transistor M23 is electrically connected to the second reset signal PWM_REF, the second electrode is electrically connected to the gate of the second drive transistor M2, and the gate is electrically connected to the sixth scan line PWM_S1. The first plate of the second capacitor C2 is electrically connected to the sweep signal line SW, and the second plate is electrically connected to the gate of the second drive transistor M2, where the sweep signal line is used to transmit the sweep signal SWEEP. The first electrode of the fourth reset transistor M26 is electrically connected to the second reference voltage SWEEP_GND, the second electrode is electrically connected to the first plate of the second capacitor C2, and the gate is electrically connected to the fourth scan line PWM_S2.

[0050] Combine Figure 5 right Figure 3 The operation process of the pixel circuit 10 is illustrated below, wherein the operation cycle R0 of the pixel circuit 10 includes a reset phase S1, a data voltage writing phase S2, and a light-emitting phase S3. During the reset phase S1, the third scan line PAM_S1 transmits an active level (e.g., a low level) to control the first reset transistor M13 to turn on, thereby resetting the gate of the first drive transistor M1. The sixth scan line PWM_S1 transmits an active level (e.g., a low level) to control the third reset transistor M23 to turn on, thereby resetting the gate of the second drive transistor M2. In the data voltage writing phase S2, the first scan line PAM_S2 transmits an effective level (for example, a low level) to control the first data writing transistor M11 and the first threshold grabbing transistor M12 to turn on, so as to write the amplitude modulated data voltage PAM_Data into the gate of the first driving transistor M1; the fourth scan line PWM_S2 transmits an effective level (for example, a low level) to control the second data writing transistor M21 and the second threshold grabbing transistor M22 to turn on, so as to write the pulse width modulated data voltage PWM_Data into the gate of the second driving transistor M2. At the same time, the second reset transistor M16 is turned on to reset the anode of the light-emitting device 20, and the fourth reset transistor M26 is turned on to reset the first plate of the second capacitor C2. In the light-emitting stage S3, the second scan line PAM_EM transmits an active level (e.g., a low level) to control the first power supply voltage write transistor M14 and the first control transistor M15, so that the first drive transistor M1 generates a drive current and transmits it to the light-emitting device 20. The fifth scan line PWM_EM transmits an active level (e.g., a low level) to control the second power supply voltage write transistor M24 and the second control transistor M25 to turn on. Furthermore, the sweep signal line SW transmits a sweep signal SWEEP, which gradually changes the potential of the gate of the second drive transistor M2 via the second capacitor C2, so that the second drive transistor M2 turns on at a certain moment and transmits the second power supply voltage PWM_VH as a shutdown signal to the gate of the first drive transistor M1, thereby turning off the first drive transistor M1 and ceasing to transmit the drive current to the light-emitting device 20. It can be seen that the pulse width modulation module 11 modulates the duration of the drive current output by the amplitude modulation module 12 to the light-emitting device 20 by controlling the shutdown time node of the first drive transistor M1.

[0051] Figure 4 Another pixel circuit 10 is shown. Figure 4 The pixel circuit 10 shown is Figure 3 The difference of the pixel circuit 10 shown is that Figure 4The third control transistor M17, the fifth reset transistor M18 and the third capacitor C3 are also included. The third control transistor M17 is electrically connected between the second electrode of the first drive transistor M1 and the light emitting device 20. Figure 4 The second electrode of the second control transistor M25 is electrically connected to the gate of the third control transistor M17, then Figure 4 The pulse width modulation module 11 in the embodiment modulates the duration of the drive current output by the amplitude modulation module 12 to the light-emitting device 20 by controlling the turn-off time node of the third control transistor M17. Specifically, the first electrode of the third control transistor M17 is electrically connected to the second electrode of the first drive transistor M1, and the second electrode is electrically connected to the first electrode of the first control transistor M15; the first electrode of the fifth reset transistor M18 is used to receive the third reset signal VSET, the second electrode is electrically connected to the gate of the third control transistor M17, and the gate is connected to the seventh scan line PAM_S3; the second electrode of the second control transistor M25 is electrically connected to the gate of the first control transistor M15, and one plate of the third capacitor C3 is electrically connected to the gate of the third control transistor M17. Figure 6 and Figure 5 The operation process of the pixel circuit 10 further includes a reset phase S1', and the seventh scan line PAM_S3 transmits an effective level (for example, a low level) to control the fifth reset transistor M18 to turn on, so as to reset the gate of the third control transistor M17 to turn it on; and in the light-emitting phase, the sweep signal line SW transmits a sweep signal SWEEP, and the sweep signal SWEEP gradually changes the potential of the gate of the second drive transistor M2 through the second capacitor C2, so that the second drive transistor M2 is turned on at a certain moment and transmits the second power supply voltage PWM_VH as a shutdown signal to the third control transistor M17, thereby turning off the third control transistor M17, thereby blocking the first drive transistor M1 from transmitting the drive current to the light-emitting device 20.

[0052] Taking the second driving transistor M2 as a P-channel transistor as an example, when the pulse width modulation data voltage PWM_Data is larger, the sweep signal SWEEP couples the gate of the second driving transistor M2 through the second capacitor C2 to enable the second driving transistor M2 to be turned on for a longer time, that is, the amplitude modulation module 12 has more time to transmit the driving current to the light-emitting unit; when the pulse width modulation data voltage PWM_Data is smaller, the sweep signal SWEEP couples the gate of the second driving transistor M2 through the second capacitor C2 to enable the second driving transistor M2 to be turned on for a shorter time, that is, the amplitude modulation module 12 has less time to transmit the driving current to the light-emitting unit. In the embodiment of the present application, Figure 5 and Figure 6As shown, when the operating mode of the display panel 01 is switched, the sweep signal SWEEP transmitted by the sweep signal line SW to the first electrode plate of the second capacitor C2 of the pulse width modulation module 11 is also different. For example, when the display panel 01 is in low brightness mode, the sweep signal SWEEP received by each pixel circuit 10 in the display panel 01 can more easily couple the potential of the gate of the first driving transistor M1 to turn on the first driving transistor M1, compared to the sweep signal SWEEP in high brightness mode. Therefore, the pulse width modulation data voltage PWM_Data received by the display panel 01 in low brightness mode can be appropriately increased, thereby improving the brightness resolution of the display panel 01 in low brightness mode and reducing the impact of the pulse width modulation data voltage PWM_Data loss on the brightness resolution.

[0053] It should be noted that Figure 3 and Figure 4 The two pixel circuits 10 are provided for exemplary purposes only. The technical solutions of this application can also be applied to other display panels 01 including similar pixel circuits 10. Furthermore, since the second driver transistor M2 is a P-channel transistor, the sweep signal SWEEP that controls the second driver transistor M2 to turn on through coupling is switched from high to low. In some embodiments, when the second driver transistor M2 is an N-channel transistor, the sweep signal SWEEP can also be switched from low to high. The following description uses the example of the sweep signal SWEEP switching from high to low to control the second driver transistor M2 from turning on to turning off.

[0054] refer to Figure 5 and Figure 6 In the operation of the pixel circuit 10, the effective level period (low level period) in the first control signal and the sweep signal SWEEP at least partially overlap, so as to ensure that the period when the first control transistor M15 is turned on coincides with the moment when the second drive transistor M2 is turned on, thereby realizing the duration for the pulse width modulation module 11 to control the amplitude modulation module 12 to transmit the drive current to the light-emitting device 20.

[0055] In one embodiment of the present application, during operation of the pixel circuit 10, the start time of the sweep signal SWEEP is earlier than the start time of the effective level in the first control signal. That is, during the overlapping effective level periods of the sweep signal SWEEP and the first control signal, the sweep signal SWEEP begins to transition from high to low before the first control signal becomes effective. During operation of the pixel circuit 10, the start time of the first ramp signal B1 is earlier than the start time of the effective level in the first control signal PAM-EM, that is, earlier than the falling edge of the first control signal PAM-EM. To ensure that the light-emitting device 20 can achieve a non-luminous state (i.e., displaying the brightness corresponding to grayscale 0), the amplitude modulation module 12 can be prevented from transmitting a driving current to the light-emitting device 20. Therefore, the sweep signal SWEEP can transmit a shutdown signal to the amplitude modulation module 12 before the first control transistor M15 turns on. Therefore, the sweep signal SWEEP begins to transition from high to low before the first control signal becomes effective, enabling the second drive transistor M2 to turn on and transmit a shutdown signal to the amplitude modulation module 12 before the first control signal becomes effective. At the same time, the longer the sweep signal SWEEP lasts, the more accurate the grayscale control can be achieved.

[0056] Figure 7 A timing diagram of some signals in a display panel provided in an embodiment of the present application is provided. Figure 8 A timing diagram of some signals in a display panel provided in an embodiment of the present application is provided. Figure 9 A timing diagram of some signals in a display panel provided in an embodiment of the present application.

[0057] In one embodiment of the present application, Figure 7-Figure 9 As shown, the rate of change of the voltage of the first sweep signal SWEEP1 over time is greater than the rate of change of the voltage of the second sweep signal SWEEP2 over time. That is, the rate of change of the sweep signal SWEEP received by the display panel 01 in low brightness mode is greater than the rate of change of the sweep signal SWEEP received in high brightness mode. Therefore, the sweep signal SWEEP received by the display panel 01 in low brightness mode can increase the rate of change of the gate potential of the second driving transistor M2 from high to low through coupling compared to that in high brightness mode. This ensures that the pulse width modulation data voltage PWM_Data received by the second driving transistor M2 can be appropriately increased while the duration of the amplitude modulation module 12 transmitting the driving current to the light-emitting device 20 in low brightness mode remains unchanged.

[0058] In one embodiment, Figure 7As shown, the maximum voltage difference of the first sweep signal SWEEP1 is ΔV1, and the maximum voltage difference of the second sweep signal SWEEP2 is ΔV2, where ΔV1>ΔV2. The maximum voltage difference of the sweep signal SWEEP is the difference between the voltage of the sweep signal SWEEP before it changes from high to low and the voltage of the sweep signal SWEEP after it changes from high to low. That is, when the display panel 01 is in low brightness mode, the degree to which the voltage of the sweep signal SWEEP received by the pulse width modulation module 11 changes from high to low is greater than that in high brightness mode. Through this embodiment, the rate of change of the voltage of the first sweep signal SWEEP1 over time can be greater than the rate of change of the voltage of the second sweep signal SWEEP2 over time.

[0059] In one technical solution, the duration of the first sweep signal SWEEP1's change can be equal to the duration of the second sweep signal SWEEP2's change. This solution primarily achieves a greater rate of change of the voltage of the first sweep signal SWEEP1 over time than the rate of change of the voltage of the second sweep signal SWEEP2 over time by setting the maximum voltage difference between the first sweep signal SWEEP1 and the second sweep signal SWEEP2 to be different. Furthermore, the duration of the first sweep signal SWEEP1's change being equal to the duration of the second sweep signal SWEEP2 prevents the sweep signal SWEEP from maintaining a simple timing sequence, thereby avoiding excessively increasing the computing power of the IC driving the display panel 01 to emit light.

[0060] In one embodiment, Figure 8 As shown, the time length for the first sweep signal SWEEP1 to change is T1, and the time length for the second sweep signal SWEEP2 to change is T2, where T1 < T2. The time length for the sweep signal SWEEP to change is the time length for the sweep signal SWEEP to change from high to low. That is, when the display panel 01 is in low brightness mode, the time length for the voltage of the sweep signal SWEEP received by the pulse width modulation module 11 to change from high to low to a preset voltage is shorter. This embodiment allows the voltage change rate of the first sweep signal SWEEP1 to be greater than the voltage change rate of the second sweep signal SWEEP2 over time.

[0061] In one technical solution, the maximum voltage difference of the first sweep signal SWEEP1 can be equal to the maximum voltage difference of the second sweep signal SWEEP2. This solution primarily achieves a greater rate of change of the voltage of the first sweep signal SWEEP1 over time than the rate of change of the voltage of the second sweep signal SWEEP2 over time by setting the time length of the first sweep signal SWEEP1's change to be different from the time length of the second sweep signal SWEEP2's change. Furthermore, the maximum voltage difference of the first sweep signal SWEEP1 can be equal to the maximum voltage difference of the second sweep signal SWEEP2, thereby avoiding excessively increasing the power consumption of the IC that drives the display panel 01 to emit light.

[0062] In one embodiment, Figure 9 As shown, the maximum voltage difference of the first sweep signal SWEEP1 is ΔV1, the maximum voltage difference of the second sweep signal SWEEP2 is ΔV2, ΔV1>ΔV2; and the time length of the change of the first sweep signal SWEEP1 is T1, the time length of the change of the second sweep signal SWEEP2 is T2, T1<T2, so as to take into account the computing power and power consumption of the IC that drives the display panel 01 to emit light.

[0063] In one embodiment of the present application, Figure 7-9 As shown, the frequency sweep signal SWEEP includes a ramp signal, the first frequency sweep signal SWEEP1 includes a first ramp signal, and the second frequency sweep signal SWEEP2 includes a second ramp signal, wherein the slope of the first ramp signal is greater than the slope of the second ramp signal. That is, the speed at which the first frequency sweep signal SWEEP1 changes from high to low is greater than the speed at which the second frequency sweep signal SWEEP2 changes from high to low, so that the second driving transistor M2 in the pulse width modulation module 11 turns on faster in the first mode D1 than in the second mode D2.

[0064] Figure 10 A timing diagram of some signals in a display panel provided in an embodiment of the present application.

[0065] In one embodiment of the present application, Figure 10 As shown, during the operation of the pixel circuit 10, the duration between the start time of the first sweep signal SWEEP1 and the start time of the valid level in the first control signal is t1, and the duration between the start time of the second sweep signal SWEEP2 and the start time of the valid level in the first control signal is t2, where t1>t2. That is, with the start time of their respective corresponding light-emitting phases as reference points, the same pixel circuit 10 begins receiving the high-to-low sweep signal SWEEP when the display panel 01 is in low-brightness mode earlier than the time when the display panel 01 is in high-brightness mode.

[0066] Combine Figure 10 When the start time of the sweep signal SWEEP is earlier than the start time of the effective level of the first control signal, the first sweep signal SWEEP1 has begun to change from high to low for a longer period of time before the effective level of the first control signal begins, compared with the second sweep signal SWEEP2. Figure 3 and Figure 4That is, the first sweep signal SWEEP1 has already begun to pull down the potential of the gate of the second driving transistor M2 from high to low through the second capacitor C2 for a longer period of time before the effective level of the first control signal begins. Comparing the degree to which the potential of the gate of the second driving transistor M2 in the same pixel circuit 10 has been pulled down from high to low at the beginning of the light-emitting phase, when the display panel 01 is in low brightness mode, the degree to which it is pulled down from high to low is greater; and when the display panel 01 is in high brightness mode, the degree to which it is pulled down from high to low is smaller. In this way, while ensuring that the duration for which the amplitude modulation module 12 transmits the driving current to the light-emitting device 20 in low brightness mode remains unchanged, the pulse width modulation data voltage PWM_Data received by the second driving transistor M2 can be appropriately increased.

[0067] In one embodiment, the end time of at least one sweep signal SWEEP is later than the end time of the effective level of the first control signal. For example, the end time of the second sweep signal SWEEP2 is later than the end time of the effective level of the first control signal.

[0068] In one technical solution, the first sweep signal SWEEP1 and the second sweep signal SWEEP2 end at different times. For example, the first sweep signal SWEEP1 may end at the same time as the effective level of the first control signal, while the second sweep signal SWEEP2 may end later than the effective level of the first control signal. In this case, the first sweep signal SWEEP1 and the second sweep signal SWEEP2 can have the same duration. Therefore, the driving module can generate the first and second sweep signals SWEEP1 and SWEEP2 by changing the timing of the sweep signals.

[0069] In one technical solution, the first sweep signal SWEEP1 and the second sweep signal SWEEP2 end at the same time. For example, the end time of the first sweep signal SWEEP1 is also later than the end time of the active level of the first control signal.

[0070] Figure 11 A timing diagram of some signals in a display panel provided in an embodiment of the present application.

[0071] As described above, the luminous brightness of the light emitting device 20 is related to its luminous time, and the luminous brightness can be controlled by controlling the luminous time of the light emitting device 20. In one embodiment of the present application, Figure 11 As shown, during the working cycle R0 of the display panel 01 displaying one frame of image, the number of times the first sweep signal SWEEP1 changes is less than the number of times the second sweep signal SWEEP2 changes. The number of times the sweep signal SWEEP changes is the same as the number of times the first control signal appears at a valid level, as shown in FIG. Figure 11 and Figure 12 As shown, the sweep signal SWEEP corresponds to the effective level period of the first control signal one by one. Figure 11 As shown, within the working cycle R0 of the time when the display panel 01 displays one frame of the picture, the pixel circuit 10 receives the sweep frequency signal SWEEP twice that changes from high to low when the display panel 01 is in the first mode D1, and the two sweep frequency signals SWEEP overlap with the effective level (low level) of the first control signal in a one-to-one correspondence. The pixel circuit 10 receives the sweep frequency signal SWEEP three times that changes from high to low when the display panel 01 is in the second mode D2, and the three sweep frequency signals SWEEP overlap with the effective level (low level) of the first control signal in a one-to-one correspondence.

[0072] In this embodiment, the number of times the light-emitting device 20 in the display panel 01 emits light in the low-brightness mode is less than the number of times the light-emitting device 20 in the display panel 01 emits light in the high-brightness mode within the duty cycle R0 of the time it takes for the display panel 01 to display one frame of an image. Therefore, the display panel 01 emits light more frequently in the high-brightness mode, thereby alleviating the flickering problem of the display panel 01 in the high-brightness mode. At the same time, the number of times the display panel 01 receives the sweep signal SWEEP in the low-brightness mode is reduced, thereby saving power consumption.

[0073] Figure 12 A schematic diagram of the correspondence between a sweep frequency signal and brightness segments in a display panel provided in an embodiment of the present application.

[0074] In one embodiment of the present application, Figure 12 As shown, the brightness of the display panel 01 is different in different working modes, that is, the brightness of the light-emitting device 20 of the display panel 01 when displaying the highest gray scale (255 gray scale) in different working modes is different, wherein the brightness in some working modes is similar. Based on this, the brightness of the display panel 01 is divided into multiple brightness segments, and the brightness of the display panel 01 can include at least two brightness segments, and the at least two brightness segments include a first brightness segment and a second brightness segment. For a clear understanding, the brightness bar that can be adjusted in the operation interface of the display panel 01 can be used as an example for explanation. In response to the user's adjustment of the brightness bar, the display panel 01 switches the working mode, wherein a segment in the brightness bar corresponds to a brightness segment, and therefore, the first brightness segment and the second brightness segment can correspond to different segments in the brightness bar without overlapping.

[0075] Each brightness segment includes multiple brightness nodes, for example, Figure 12The first brightness segment includes three brightness nodes, from the first brightness node to the third brightness node, and the second brightness segment includes three brightness nodes, from the fourth brightness node to the sixth brightness node, respectively. Each brightness node corresponds to one operating mode. For example, the second brightness node in the first brightness segment corresponds to the first mode D1, and the first and third brightness nodes in the first brightness segment can correspond to other operating modes, respectively. The fourth brightness node in the second brightness segment corresponds to the second mode D2, and the fifth and sixth brightness nodes in the second brightness segment can correspond to other operating modes, respectively.

[0076] In addition, the brightness of the display panel may include a first brightness segment and a second brightness segment, and the brightness value of the first brightness segment is smaller than the brightness value of the second brightness segment. When the operating mode of the display panel is the first mode, the brightness of the display panel may vary within the first brightness segment, and when the operating mode of the display panel is the second mode, the brightness of the display panel may vary within the second brightness segment. Then one brightness segment may correspond to one operating mode, that is,

[0077] In this embodiment, the brightness of the display panel 01 in the first brightness segment is lower than the brightness of the display panel 01 in the second brightness segment. The brightness of the highest grayscale displayed when the working mode of the display panel 01 corresponds to any brightness node in the first brightness segment is lower than the brightness of the highest grayscale displayed when the working mode of the display panel 01 corresponds to any brightness node in the second brightness segment. For example, Figure 12 As shown, when the operating modes of the display panel 01 correspond to the three brightness nodes in the first brightness segment, the brightness of the light-emitting device 20 displayed at 255 grayscale is 20 nits, 50 nits, and 80 nits respectively; when the operating modes of the display panel 01 correspond to the three brightness nodes in the second brightness segment, the brightness of the light-emitting device 20 displayed at 255 grayscale is 150 nits, 200 nits, and 250 nits respectively. Therefore, the maximum brightness that the display panel 01 can display in the first brightness segment is lower than the maximum brightness that the display panel 01 can display in the second brightness segment.

[0078] In the first brightness segment, the sweep frequency signal SWEEP is the same; in the second brightness segment, the sweep frequency signal SWEEP is the same; and the sweep frequency signal SWEEP in the first brightness segment is different from the sweep frequency signal SWEEP in the second brightness segment. That is, when the brightness node corresponding to the working mode of the display panel 01 belongs to the first brightness segment, the sweep frequency signal SWEEP it receives is different from the sweep frequency signal SWEEP it receives when the brightness node corresponding to the working mode of the display panel 01 belongs to the second brightness segment. For example, Figure 12As shown, the brightness node corresponding to the first mode D1 belongs to the first brightness segment and the brightness node corresponding to the second mode D2 belongs to the second brightness segment. Since the display panel 01 receives the first sweep signal SWEEP1 in the first mode D1 and the second sweep signal SWEEP2 in the second mode D2, the first brightness segment corresponds to the first sweep signal SWEEP1 and the second brightness segment corresponds to the second sweep signal SWEEP2.

[0079] In one embodiment, when the brightness of the display panel 01 belongs to the first brightness range, the display panel 01 receives the first sweep signal SWEEP1; when the brightness of the display panel 01 belongs to the second brightness range, the display panel 01 receives the second sweep signal SWEEP2.

[0080] In the technical solution corresponding to this embodiment, when the multiple operating modes of the display panel 01 correspond to the first brightness range, the display panel 01 receives the same sweep signal SWEEP when operating in these multiple operating modes. When the multiple operating modes of the display panel 01 correspond to the second brightness range, the display panel 01 also receives the same sweep signal SWEEP when operating in these multiple operating modes. Therefore, the number of mappings between the sweep signal SWEEP and the operating modes stored in the register of the driver device used to drive the display panel 01 is less than the number of operating modes, thereby avoiding excessive storage pressure on the register.

[0081] Furthermore, within the same brightness range, the amplitude modulated data voltage PAM_Data received by the pixel circuit 10 can be the same; and within different brightness ranges, the amplitude modulated data voltage PAM_Data received by the pixel circuit 10 can be different. That is, when the brightness nodes corresponding to multiple operating modes of the display panel 01 belong to the same brightness range, the amplitude modulated data voltage PAM_Data received by the pixel circuit 10 of the display panel 01 in these operating modes is different; when the brightness nodes corresponding to at least two operating modes of the display panel 01 belong to different brightness ranges, the amplitude modulated data voltage PAM_Data received by the pixel circuit 10 of the display panel 01 in these operating modes is different. In multiple working modes corresponding to the same brightness segment, the display panel 01 receives the same amplitude modulation data voltage PAM_Data, which can reduce the pressure on the register to store the amplitude modulation data voltage PAM_Data; in different working modes corresponding to different brightness segments, the display panel 01 receives different amplitude modulation data voltages PAM_Data, which can widen the range of the pulse width modulation data voltage PWM_Data in the working mode, especially in the low brightness mode, thereby increasing the actual brightness difference corresponding to adjacent grayscales and improving the accuracy of grayscale expression.

[0082] Figure 13A schematic diagram of the correspondence between a sweep frequency signal and brightness segments in a display panel provided in an embodiment of the present application.

[0083] In one embodiment of the present application, Figure 13 As shown, the brightness of the display panel 01 also includes a third brightness segment, and the brightness of the third brightness segment is greater than the brightness of the second brightness segment. The brightness of the brightness segment has been described in the previous embodiment and will not be repeated here. In this embodiment, the sweep signal SWEEP in the second brightness segment is the same as the sweep signal SWEEP in the third brightness segment. That is, when the different operating modes of the display panel 01 belong to the second brightness segment and the second brightness segment respectively, the display panel 01 receives the same SWEEP signal in these different operating modes.

[0084] As described above, the brightness of the second brightness segment is greater than that of the first brightness segment. When the brightness of the third brightness segment is greater than that of the second brightness segment, it means that the brightness of the second brightness segment and the brightness of the third brightness segment both correspond to the brightness segments with higher brightness of the display panel. In the operating mode corresponding to each brightness node in the brightness segment with higher brightness, the maximum pulse width modulation data voltage that the display panel can receive is larger and the difference in pulse width modulation data voltages corresponding to adjacent grayscales is also larger. Therefore, the problem of brightness resolution is relatively mild in the brightness segment with higher brightness. At this time, the second brightness segment and the third brightness segment share the same sweep frequency signal, so there will be no obvious brightness resolution problem, and the storage capacity of the register and the computing power of the driver module are not required to be high.

[0085] Figure 14 A schematic diagram of the correspondence between a gamma curve and brightness segments in a display panel provided in an embodiment of the present application.

[0086] In one embodiment of the present application, a brightness segment includes multiple brightness nodes, meaning that the operating modes of the display panel 01 can correspond to the same brightness segment. In these operating modes, the brightness of the light-emitting devices 20 in the display panel 01 when displaying the maximum grayscale varies. In these operating modes, the pulse-width modulation data voltages PWM_Data received by the display panel 01 and the grayscales have different mapping relationships. Therefore, when the display panel 01 operates in operating modes corresponding to two different brightness nodes within the same brightness segment, the data voltages received by the display panel 01 are obtained by searching different mapping tables between the pulse-width modulation data voltages PWM_Data and grayscales, wherein the different mapping tables between the pulse-width modulation data voltages PWM_Data and grayscales correspond to different gamma curves.

[0087] That is, the first brightness segment or the second brightness segment includes a first brightness node and a second brightness node, and the brightness of the first brightness node is different from the brightness of the second brightness node. For example, the brightness of the first brightness node is smaller than the brightness of the second brightness node. Figure 14 As shown, the first brightness segment includes a first brightness node and a second brightness node. The pulse-width modulated data voltage PWM_Data received by the display panel 01 at the first brightness node corresponds to the first gamma curve, and the pulse-width modulated data voltage PWM_Data received by the display panel 01 at the second brightness node corresponds to the second gamma curve. That is, when the operating mode of the display panel 01 corresponds to the first brightness node, the pulse-width modulated data voltage PWM_Data received by the display panel 01 is obtained by searching the mapping table corresponding to the first gamma curve; when the operating mode of the display panel 01 corresponds to the second brightness node, the pulse-width modulated data voltage PWM_Data received by the display panel 01 is obtained by searching the mapping table corresponding to the second gamma curve.

[0088] In one embodiment, the first brightness segment or the second brightness segment further includes a third brightness node, the brightness of the third brightness node is less than the brightness of the second brightness node, and the brightness value of the third brightness node is greater than the brightness value of the first brightness node. Figure 14 As shown, the first brightness includes a first brightness node, a second brightness node and a third brightness node, wherein the brightness value of the light-emitting device 20 in the display panel 01 when displaying 255 grayscale in the working mode corresponding to the first brightness node is 20nit, the brightness value when displaying 255 grayscale in the working mode corresponding to the third brightness node is 50nit, and the brightness value when displaying 255 grayscale in the working mode corresponding to the second brightness node is 80nit.

[0089] The pulse-width modulated data voltage PWM_Data received by the display panel 01 at the third brightness node is obtained through an interpolation algorithm based on the pulse-width modulated data voltage PWM_Data corresponding to the first gamma curve and the pulse-width modulated data voltage PWM_Data corresponding to the second gamma curve. When the light-emitting device 20 presents the same grayscale brightness, the pulse-width modulated data voltage PWM_Data received by the pixel circuit 10 in the operating mode corresponding to the third brightness node is between the pulse-width modulated data voltage PWM_Data received in the operating mode corresponding to the first brightness node and the pulse-width modulated data voltage PWM_Data received in the operating mode corresponding to the second brightness node. Therefore, the pulse-width modulated data voltage PWM_Data to be received in the operating mode corresponding to the third brightness node can be obtained through the interpolation algorithm.

[0090] In one technical solution, the pulse-width modulation data voltage PWM_Data that the pixel circuit 10 should receive in the operating mode corresponding to the third brightness node can be obtained by linear differentiation. Assuming that the first brightness segment includes the above-mentioned three brightness nodes and the three brightness nodes are evenly distributed within the first brightness segment, the pulse-width modulation data voltage PWM_Data received by the pixel circuit 10 when driving the light-emitting device 20 to present a brightness corresponding to 255 grayscale (e.g., 20 nits) in the operating mode corresponding to the first brightness node is 2V, and the pulse-width modulation data voltage PWM_Data received by the pixel circuit 10 when driving the light-emitting device 20 to present a brightness corresponding to 255 grayscale (e.g., 80 nits) in the operating mode corresponding to the second brightness node is 3V. It can be seen that the horizontal coordinate corresponding to the first brightness node is 1 and the vertical coordinate is 2V, and the vertical coordinate corresponding to the second brightness node is 3 and the vertical coordinate is 3V, wherein the horizontal coordinate corresponding to the third brightness node is 2. Then, through linear differential method, it can be obtained that the pulse width modulation data voltage PWM_Data that should be received when the pixel circuit 10 drives the light-emitting device 20 to present the brightness corresponding to 255 gray levels (for example, 50nit) in the working mode corresponding to the third brightness node is 2.5V.

[0091] In the solution provided in this embodiment, the register can store the pulse-width modulation data voltage PWM_Data corresponding to some brightness nodes. That is, the register only stores at least some of the pulse-width modulation data voltage PWM_Data required for some operating modes of the display panel 01, thereby avoiding excessive storage pressure on the register. When the pulse-width modulation data voltage PWM_Data required for the operating modes not stored in the register is obtained through linear differentiation, the algorithm is simple and does not require high computing power from the driver module.

[0092] In one embodiment, the pulse width modulation data voltage PWM_Data received by two adjacent brightness nodes respectively located in the first brightness segment and the second brightness segment corresponds to different gamma curves. Different brightness nodes are sorted according to brightness, wherein the mapping relationship between the pulse width modulation data voltage PWM_Data corresponding to two adjacent brightness nodes respectively located in the two brightness segments and the partial grayscale is stored in a register. For example, Figure 14 As shown, the second brightness node in the first brightness segment is adjacent to the fourth brightness node in the second brightness segment, the second brightness node corresponds to the second Gamma curve and the fourth node corresponds to the third Gamma curve, then the register stores the mapping relationship between the partial pulse width modulation data voltage PWM_Data received by the display panel 01 in the working mode corresponding to the second brightness node and the grayscale, and the register stores the relationship between the partial pulse width modulation data voltage PWM_Data received by the display panel 01 in the working mode corresponding to the fourth brightness node and the grayscale.

[0093] For two adjacent brightness nodes located within two brightness segments, although the brightness of the two brightness nodes is adjacent, because they belong to different brightness segments, their corresponding swept frequency signals SWEEP may be different. If an interpolation algorithm such as linear difference is used to obtain the pulse width modulation data voltage PWM_Data corresponding to at least one of the two brightness nodes, the difference in the swept frequency signal SWEEP must also be considered, which requires high computing power and may cause significant distortion in the brightness of the light-emitting device 20.

[0094] In one embodiment of the present application, Figure 1 As shown, the light-emitting device 20 includes a first-color light-emitting device 21 and a second-color light-emitting device 22. In the first mode D1 or the second mode D2, the pixel circuit 10 electrically connected to the first-color light-emitting device 21 and the pixel circuit 10 electrically connected to the second-color light-emitting device 22 respectively receive different sweep signals SWEEP. The manner in which the pixel circuit 10 electrically connected to the first-color light-emitting device 21 and the pixel circuit 10 electrically connected to the second-color light-emitting device 22 respectively receive different sweep signals SWEEP can refer to the differentiated design scheme of the first sweep signal SWEEP1 and the second sweep signal SWEEP2.

[0095] The luminous efficiency of the light-emitting devices 20 that emit light of different colors is different. According to the actual needs of the light-emitting devices that emit light of different colors, the sweep signal SWEEP received by the pixel circuit 10 electrically connected to the light-emitting devices 20 of different colors can be adjusted in a targeted manner to ensure that the light-emitting devices 20 of different colors of the display panel 01 can all have a higher brightness resolution. In particular, it can improve the color deviation problem caused by the different brightness resolution loss of the light emitted by the light-emitting devices of different colors in low brightness mode.

[0096] Figure 15 A timing diagram of some signals in a display panel provided in an embodiment of the present application.

[0097] In one embodiment, Figure 15As shown, the wavelength of light emission of the first color light emitting device 21 is greater than the wavelength of light emission of the second color light emitting device 22, and the rate of change of the sweep signal SWEEP21 corresponding to the first color light emitting device 21 over time is less than the rate of change of the sweep signal SWEEP22 corresponding to the second color light emitting device 22 over time. Then the first color light emitting device 21 can be a red light emitting device, and the second color light emitting device 22 can be a blue light emitting device or a green light emitting device. The wavelength of red light is greater than the wavelength of blue light and the wavelength of green light, and the luminous efficiency of the red light emitting device is less than the luminous efficiency of the blue light emitting device and less than the luminous efficiency of the green light emitting device. Therefore, in a solution corresponding to this embodiment, the luminous efficiency of the first color light emitting device 21 is less than the efficiency of the second color light emitting device 22. Among them, the rate of change of the voltage of the sweep signal received by the pixel circuit 10 to which the first color light emitting device 21 with lower luminous efficiency is electrically connected over time should be smaller, so as to delay the time when the pulse width modulation module 11 outputs the shutdown signal to the amplitude modulation module 12, so that the first color light emitting device 21 receives the driving current for a longer time. It should be noted that Figure 15 A different form of the sweep signal SWEEP22 and the sweep signal SWEEP21 is shown. The differentiated design of the sweep signal SWEEP22 and the sweep signal SWEEP21 can also refer to the differentiation of the first sweep signal SWEEP1 and the second sweep signal SWEEP2.

[0098] In this embodiment, the pixel circuits 10 electrically connected to at least two different-colored light-emitting devices 20 can receive different sweep signals in the same operating mode, and the pixel circuit 10 electrically connected to any one of the at least two different-colored light-emitting devices 20 receives different sweep signals SWEEP in the first mode D1 and the second mode D2. Therefore, the embodiments of the present application can specifically improve the brightness resolution of light-emitting devices 20 of different colors and improve color shift issues.

[0099] In this embodiment, the display panel 01 may further include a third-color light-emitting device 23. The luminous efficiency of the third-color light-emitting device 23 is between the luminous efficiency of the first-color light-emitting device 21 and the luminous efficiency of the second-color light-emitting device 22. Therefore, the time-varying rate of the swept-frequency signal SWEEP corresponding to the third-color light-emitting device 23 may be between the time-varying rate of the swept-frequency signal SWEEP corresponding to the second-color light-emitting device 22 and the time-varying rate of the swept-frequency signal SWEEP corresponding to the first-color light-emitting device 21. The first-color light-emitting device 21 may be a red light-emitting device, the second-color light-emitting device 22 may be a blue light-emitting device, and the third-color light-emitting device 23 may be a green light-emitting device.

[0100] Figure 16 A schematic diagram of a display panel provided in an embodiment of the present application.

[0101] Due to the influence of temperature, voltage drop, etc., the luminous efficiency of the light emitting devices 20 at different positions in the display panel 01 may be different. Therefore, the display area AA of the display panel 01 can be divided into at least two areas, that is, the display area AA of the display panel includes a first display area A1 and a second display area A2. Figure 16 As shown, in the first mode D1 or the second mode D2, the first display area A1 receives the same sweep signal SWEEP, the second display area A2 receives the same sweep signal SWEEP, and the first display area A1 receives a different sweep signal SWEEP than the second display area A2. For example, the first display area A1 receives the sweep signal SWEEPA1, and the second display area A2 receives the sweep signal SWEEPA2.

[0102] In one technical solution, when the display panel 01 is in the first mode D1, the first display area A1 receives the same sweep signal SWEEP, the second display area A2 receives the same sweep signal SWEEP, and the first display area A1 and the second display area A2 receive different sweep signals SWEEP. When the display panel 01 is in the second mode D2, the first display area A1 receives the same sweep signal SWEEP, the second display area A2 receives the same sweep signal SWEEP, and the first display area A1 and the second display area A2 receive different sweep signals SWEEP.

[0103] This embodiment can specifically adjust the sweep signal SWEEP received by the pixel circuit 10 electrically connected to the light-emitting devices in different areas according to the light emission of the light-emitting devices 20 at different positions in the display area AA in the display panel 01 and actual needs, thereby ensuring that the light-emitting devices 20 in different areas of the display panel 01 can all have a higher brightness resolution and improve display uniformity.

[0104] Figure 17 A schematic diagram of a display device provided in an embodiment of the present application.

[0105] like Figure 17 As shown, the embodiment of the present application further provides a display device 001, comprising the display panel 01 provided in any of the above embodiments. Figure 17 The display device 001 shown is for illustration only and can be any electronic device with a display function, such as a mobile phone, tablet computer, laptop computer, e-reader, television, spliced ​​display device, etc. The display device 001 provided in the embodiment of the present application has good brightness resolution.

[0106] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A display panel, characterized in that: It includes a pixel circuit and a light-emitting device; wherein, The pixel circuit includes a pulse width modulation module, and the pulse width modulation module is configured to modulate the light emitting duration of the light emitting device based on a pulse width modulation data voltage and a sweep frequency signal; The operating mode of the display panel includes a first mode and a second mode, the brightness of the display panel in the first mode is L1, and the brightness of the display panel in the second mode is L2, L1<L2; The frequency sweep signal received by the pulse width modulation module in the first mode is a first frequency sweep signal, and the frequency sweep signal received by the pulse width modulation module in the second mode is a second frequency sweep signal, and the first frequency sweep signal is different from the second frequency sweep signal.

2. The display panel according to claim 1, wherein: A rate of change of the voltage of the first frequency sweep signal over time is greater than a rate of change of the voltage of the second frequency sweep signal over time.

3. The display panel according to claim 2, wherein: The time length of the change of the first frequency sweep signal is T1, the time length of the change of the second frequency sweep signal is T2, and T1<T2.

4. The display panel according to claim 2, wherein: The maximum voltage difference of the first frequency sweep signal is ΔV1, the maximum voltage difference of the second frequency sweep signal is ΔV2, and ΔV1>ΔV2.

5. The display panel according to claim 1, wherein: The frequency sweep signal includes a ramp signal, the first frequency sweep signal includes a first ramp signal, and the second frequency sweep signal includes a second ramp signal; The slope of the first ramp signal is greater than the slope of the second ramp signal.

6. The display panel according to claim 1, wherein: During one frame of the display panel, the number of times the first frequency sweep signal changes is less than the number of times the second frequency sweep signal changes.

7. The display panel according to claim 1, wherein: The brightness of the display panel includes a first brightness range and a second brightness range, and the brightness of the display panel in the first brightness range is smaller than the brightness of the display panel in the second brightness range; In the first brightness range, the frequency sweep signals are the same; In the second brightness segment, the frequency sweep signals are the same; and the frequency sweep signals in the first brightness segment are different from the frequency sweep signals in the second brightness segment.

8. The display panel according to claim 7, wherein: The brightness of the display panel further includes a third brightness range, and the brightness of the third brightness range is greater than the brightness of the second brightness range; The frequency sweep signal in the second brightness range is the same as the frequency sweep signal in the third brightness range.

9. The display panel according to claim 7, wherein: The first brightness segment or the second brightness segment includes a first brightness node and a second brightness node, and the brightness of the first brightness node is smaller than the brightness of the second brightness node; The pulse width modulation data voltage received by the display panel at the first brightness node corresponds to a first Gamma curve, and the pulse width modulation data voltage received by the display panel at the second brightness node corresponds to a second Gamma curve.

10. The display panel according to claim 9, wherein: The first brightness segment or the second brightness segment further includes a third brightness node, the brightness value of the third brightness node is smaller than the brightness of the second brightness node, and the brightness value of the third brightness node is greater than the brightness of the first brightness node; The pulse width modulation data voltage received by the display panel at the third brightness node is obtained through an interpolation algorithm based on the pulse width modulation data voltage corresponding to the first gamma curve and the pulse width modulation data voltage corresponding to the second gamma curve.

11. The display panel according to claim 9, wherein The pulse width modulation data voltages respectively received by two adjacent brightness nodes respectively located in the first brightness segment and the second brightness segment correspond to different Gamma curves.

12. The display panel according to claim 1, wherein The light emitting device includes a first color light emitting device and a second color light emitting device; In the first mode or the second mode, the pixel circuit electrically connected to the first color light emitting device and the pixel circuit electrically connected to the second color light emitting device respectively receive different sweep frequency signals.

13. The display panel according to claim 12, wherein: The emission wavelength of the first color light emitting device is greater than the emission wavelength of the second color light emitting device, and the voltage change rate of the sweep signal corresponding to the first color light emitting device over time is less than the voltage change rate of the sweep signal corresponding to the second color light emitting device over time.

14. The display panel according to claim 1, wherein The display area of ​​the display panel includes a first display area and a second display area; In the first mode or the second mode, the sweep frequency signals received by the first display area are the same, the sweep frequency signals received by the second display area are the same, and the sweep frequency signals received by the first display area are different from the sweep frequency signals received by the second display area.

15. The display panel according to claim 1, wherein The pixel circuit further includes an amplitude modulation module; the amplitude modulation module is configured to modulate the amplitude of the driving current received by the light-emitting device based on the amplitude modulation data voltage, and the output end of the pulse width modulation module is electrically connected to the amplitude modulation module; The amplitude modulation module includes a first driving transistor and a first control transistor, wherein the first driving transistor is electrically connected to the first control transistor and the first control transistor is configured to control the first driving transistor to output the driving current based on a first control signal; During operation of the pixel circuit, the effective level period of the first control signal at least partially overlaps with the frequency sweep signal.

16. The display panel according to claim 15, wherein: During operation of the pixel circuit, the start time of the frequency sweep signal is earlier than the start time of the effective level in the first control signal.

17. The display panel according to claim 16, wherein: During operation of the pixel circuit, the duration between the starting moment of the first frequency sweep signal and the starting moment of the effective level in the first control signal is t1, and the duration between the starting moment of the second frequency sweep signal and the starting moment of the effective level in the first control signal is t2, and t1>t2.

18. The display panel according to claim 16, wherein: The end time of at least part of the frequency sweep signals is later than the end time of the effective level in the first control signal.

19. The display panel according to claim 18, wherein: The first frequency sweep signal and the second frequency sweep signal have different ending times.

20. A display device, characterized in that: Comprising the display panel according to any one of claims 1-19.

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