Display driving circuit, display driving chip and display driving method

Abstract

The present disclosure relates to a display driving circuit, a display driving chip and a display driving method. The display driving circuit is configured to: in response to a current frame distance from a previous threshold voltage compensation not reaching a preset number of frames, turn off an emission signal of the pixel circuit within a first time length at the beginning of the current frame, and perform display data writing on the pixel circuit, and turn on the emission signal of the pixel circuit after the first time length; in response to the current frame distance from the previous threshold voltage compensation reaching the preset number of frames, turn off the emission signal of the pixel circuit within a second time length at the beginning of the current frame, and sequentially perform initialization, driving transistor threshold voltage compensation and display data writing on the pixel circuit, and turn on the emission signal of the pixel circuit after the second time length; wherein the second time length is greater than the first time length.

Description

Technical Field

[0001] This disclosure relates to the field of display driver technology, specifically to a display driver circuit, a display driver chip, and a display driver method. Background Technology

[0002] OLED (Organic Light Emitting Diode) display panels are widely used in mobile phones, tablets, laptops, portable displays, and other terminal products due to their advantages such as self-illumination, high contrast, and thinness. To balance low power consumption and high image quality, the industry has gradually developed LTPO (Low-Temperature Polycrystalline Oxide) display panels and LTPO+ (all-oxide LTPO) display panels, which offer improvements in both power consumption and display performance compared to traditional display panels.

[0003] The eye protection effects of related technologies such as LTPO display panels and LTPO+ display panels still need to be improved. Summary of the Invention

[0004] To overcome the problems existing in the related technologies, the present disclosure provides a display driving circuit, a display driving chip, and a display driving method to solve the defects in the related technologies.

[0005] According to a first aspect of the present disclosure, a display driving circuit is provided, wherein the pixel circuit of the display panel driven by the display driving circuit has mutually independent driving transistor threshold voltage compensation paths and display data writing paths, and the driving transistor threshold voltage compensation paths are capable of maintaining the written charge within a preset number of frames, and the display driving circuit is used for: In response to the fact that the threshold voltage compensation in the previous frame did not reach a preset number of frames, the light emission signal of the pixel circuit is disconnected during the first duration of the current frame, and display data is written to the pixel circuit. After the first duration, the light emission signal of the pixel circuit is turned on. In response to the current frame being a preset number of frames away from the previous threshold voltage compensation, the light emission signal of the pixel circuit is disconnected during the second duration at the beginning of the current frame, and the pixel circuit is initialized, the threshold voltage compensation of the driving transistor is performed, and the display data is written in sequence. After the second duration, the light emission signal of the pixel circuit is turned on. Wherein, the second duration is longer than the first duration.

[0006] In some possible embodiments of this disclosure, the display driving circuit is used for: In response to the fact that the current frame is less than a preset number of frames away from the previous threshold voltage compensation, the display data written in the current frame is determined based on the first Gamma curve; In response to the current frame being a preset number of frames since the last threshold voltage compensation, the display data written in the current frame is determined based on the second Gamma curve; The duty cycle corresponding to the first duration and the display brightness presented by the display data determined based on the first Gamma curve are the same as the duty cycle corresponding to the second duration and the display brightness presented by the display data determined based on the second Gamma curve.

[0007] In some possible embodiments of this disclosure, the display driving circuit is used for: In response to the fact that the threshold voltage compensation for the current frame did not reach a preset number of frames, the pixel circuit is also reset during the first duration of the current frame.

[0008] In some possible embodiments of this disclosure, the display driving circuit is used for: In response to the current frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the first or second duration at the beginning of the current frame, and the pixel circuit is row-reset. After the first or second duration, the light emission signal of the pixel circuit is turned on. The duration of the light emission signal that initially disconnects the pixel circuit in the hold frame is the same as the duration of the light emission signal that initially disconnects the pixel circuit in the last refresh frame before the hold frame.

[0009] In some possible embodiments of this disclosure, the display driving circuit is used for: In response to the current frame being a refresh frame and the next frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the second duration at the beginning of the current frame, and the pixel circuit is initialized, the threshold voltage of the driving transistor is compensated, and the display data is written in sequence. After the second duration, the light emission signal of the pixel circuit is turned on.

[0010] In some possible embodiments of this disclosure, the display driving circuit is used for: In response to the current frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the third duration at the beginning of the current frame, and the pixel circuit is row-reset. After the third duration, the light emission signal of the pixel circuit is turned on. The third duration is shorter than the first duration.

[0011] In some possible embodiments of this disclosure, the display driving circuit is used for: In the DC constant light emission dimming mode, the light emission signal of the pixel circuit is disconnected at least once after the first duration or the second duration, and the duration of each disconnection of the light emission signal of the pixel circuit is less than the first duration.

[0012] In some possible embodiments of this disclosure, the display driving circuit is used for: The pixel circuit is reset during the duration of each disconnection of the light emission signal.

[0013] In some possible embodiments of this disclosure, the display driving circuit is used for: In pulse width modulation (PWM) dimming mode, the duration of at least one disconnection of the light emission signal of the pixel circuit after the first duration or the second duration is extended, and the extended disconnection duration is less than the first duration.

[0014] In some possible embodiments of this disclosure, the display driving circuit is used for: During the disconnection period following the first or second duration of each extended period of the light emission signal of the pixel circuit, the pixel circuit is reset.

[0015] In some possible embodiments of this disclosure, the display driving circuit is used for: At least one row reset of the pixel circuit after the first duration or the second duration is evenly distributed within the remaining duration of the current frame after the first duration or the second duration.

[0016] According to a second aspect of the present disclosure, a display driver chip is provided, the display driver chip including the display driver circuit as described in any one of the first aspects.

[0017] According to a third aspect of the present disclosure, a display driving method is provided, wherein the pixel circuit of the display panel driven by the method has mutually independent driving transistor threshold voltage compensation paths and display data writing paths, and the driving transistor threshold voltage compensation paths are capable of maintaining the written charge within a preset number of frames, the display driving method comprising: In response to the fact that the threshold voltage compensation in the previous frame did not reach a preset number of frames, the light emission signal of the pixel circuit is disconnected during the first duration of the current frame, and display data is written to the pixel circuit. After the first duration, the light emission signal of the pixel circuit is turned on. In response to the current frame being a preset number of frames away from the previous threshold voltage compensation, the light emission signal of the pixel circuit is disconnected during the second duration at the beginning of the current frame, and the pixel circuit is initialized, the threshold voltage compensation of the driving transistor is performed, and the display data is written in sequence. After the second duration, the light emission signal of the pixel circuit is turned on. Wherein, the second duration is longer than the first duration.

[0018] In some possible embodiments of this disclosure, the method further includes: In response to the fact that the current frame is less than a preset number of frames away from the previous threshold voltage compensation, the display data written in the current frame is determined based on the first Gamma curve; In response to the current frame being a preset number of frames since the last threshold voltage compensation, the display data written in the current frame is determined based on the second Gamma curve; The duty cycle corresponding to the first duration and the display brightness presented by the display data determined based on the first Gamma curve are the same as the duty cycle corresponding to the second duration and the display brightness presented by the display data determined based on the second Gamma curve.

[0019] In some possible embodiments of this disclosure, the method further includes: In response to the fact that the threshold voltage compensation for the current frame did not reach a preset number of frames, the pixel circuit is also reset during the first duration of the current frame.

[0020] In some possible embodiments of this disclosure, the method further includes: In response to the current frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the first or second duration at the beginning of the current frame, and the pixel circuit is row-reset. After the first or second duration, the light emission signal of the pixel circuit is turned on. The duration of the light emission signal that initially disconnects the pixel circuit in the hold frame is the same as the duration of the light emission signal that initially disconnects the pixel circuit in the last refresh frame before the hold frame.

[0021] In some possible embodiments of this disclosure, the method further includes: In response to the current frame being a refresh frame and the next frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the second duration at the beginning of the current frame, and the pixel circuit is initialized, the threshold voltage of the driving transistor is compensated, and the display data is written in sequence. After the second duration, the light emission signal of the pixel circuit is turned on.

[0022] In some possible embodiments of this disclosure, the method further includes: In response to the current frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the third duration at the beginning of the current frame, and the pixel circuit is row-reset. After the third duration, the light emission signal of the pixel circuit is turned on. The third duration is shorter than the first duration.

[0023] In some possible embodiments of this disclosure, the method further includes: In the DC constant light emission dimming mode, the light emission signal of the pixel circuit is disconnected at least once after the first duration or the second duration, and the duration of each disconnection of the light emission signal of the pixel circuit is less than the first duration.

[0024] In some possible embodiments of this disclosure, the method further includes: The pixel circuit is reset during the duration of each disconnection of the light emission signal.

[0025] In some possible embodiments of this disclosure, the method further includes: In pulse width modulation (PWM) dimming mode, the duration of at least one disconnection of the light emission signal of the pixel circuit after the first duration or the second duration is extended, and the extended disconnection duration is less than the first duration.

[0026] In some possible embodiments of this disclosure, the method further includes: During the disconnection period following the first or second duration of each extended period of the light emission signal of the pixel circuit, the pixel circuit is reset.

[0027] In some possible embodiments of this disclosure, the method further includes: At least one row reset of the pixel circuit after the first duration or the second duration is evenly distributed within the remaining duration of the current frame after the first duration or the second duration.

[0028] According to a fourth aspect of the present disclosure, a computer program product is provided, including a computer program / instructions that, when executed by a processor, implement the method described in the third aspect.

[0029] According to a fifth aspect of the present disclosure, an electronic device is provided, the electronic device including a memory and a processor, the memory being configured to store computer instructions executable on the processor, and the processor being configured to implement the method of the third aspect when executing the computer instructions.

[0030] According to a sixth aspect of the present disclosure, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described in the third aspect.

[0031] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: The display driving circuit provided in this embodiment is used to drive a display panel. The display panel has independent driving transistor threshold voltage compensation paths and display data writing paths. The driving transistor threshold voltage compensation path can maintain the written charge within a preset number of frames. Therefore, in response to the current frame not reaching the preset number of frames since the previous threshold voltage compensation, the display driving circuit disconnects the light emission signal of the pixel circuit during a first duration at the beginning of the current frame and writes display data to the pixel circuit. After the first duration, the light emission signal of the pixel circuit is turned on. In response to the current frame reaching the preset number of frames since the previous threshold voltage compensation, the light emission signal of the pixel circuit is disconnected during a second duration at the beginning of the current frame, and the pixel circuit is initialized, driving transistor threshold voltage compensation is performed, and display data is written sequentially. After the second duration, the light emission signal of the pixel circuit is turned on. The second duration is longer than the first duration. In other words, when the display driving circuit can still maintain the charge after the previous threshold voltage compensation, it no longer initializes and compensates the pixel circuit. Instead, it writes the display data and directly turns on the light emission signal of the pixel circuit. This reduces the disconnection time of the light emission signal in some display frames (i.e., display frames where the pixel circuit maintains the charge after threshold voltage compensation). In other words, the time originally used for initialization and threshold voltage compensation is increased to the time when the light emission signal is turned on, thereby improving the duty cycle of the pixel circuit and improving the eye protection effect of the display panel. Attached Figure Description

[0032] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0033] Figure 1 This is a pixel circuit of the 8T1C architecture shown in an exemplary embodiment of this disclosure; Figure 2 This is a pixel circuit of a 6T2C architecture illustrated in an exemplary embodiment of this disclosure; Figure 3 This is a timing diagram of a pixel circuit of a 6T2C architecture illustrated in an exemplary embodiment of this disclosure; Figure 4 This is a stage state diagram of a pixel circuit of a 6T2C architecture illustrated in an exemplary embodiment of this disclosure; Figure 5 This is a timing diagram of a pixel circuit of a 6T2C architecture illustrated in another exemplary embodiment of this disclosure; Figure 6 This is a timing diagram of a pixel circuit illustrated in an exemplary embodiment of this disclosure; Figure 7 This is a timing diagram of a pixel circuit illustrated in another exemplary embodiment of this disclosure; Figure 8 This is a timing diagram of a pixel circuit illustrated in yet another exemplary embodiment of this disclosure; Figure 9 This is a timing diagram of a pixel circuit illustrated in yet another exemplary embodiment of this disclosure; Figure 10 This is a timing diagram of a pixel circuit of a 6T2C architecture illustrated in yet another exemplary embodiment of this disclosure; Figure 11 This is a flowchart illustrating a display driving method according to an exemplary embodiment of this disclosure; Figure 12 This is a structural block diagram of an electronic device illustrated in an exemplary embodiment of the present disclosure. Detailed Implementation

[0034] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0035] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0036] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0037] In LTPO display panels, the switching transistors in the pixel circuits generally use polycrystalline silicon PMOS transistors. The manufacturing process requires laser crystallization, which can easily lead to uneven grain size distribution, causing defects such as mura spots and poor image uniformity. To improve this problem, the industry has proposed LTPO+ (all-oxide LTPO) display panels, in which all switching transistors in the pixel circuits use oxide NMOS transistors. The film is formed by sputtering, eliminating the need for laser crystallization. The film uniformity is excellent, which can effectively suppress display spots. At the same time, oxide NMOS transistors can achieve channel miniaturization, with ample space for pixel layout, which is beneficial for high resolution and narrow bezel design.

[0038] The eye protection effect of display panels such as LTPO+ display panels in related technologies still needs to be improved.

[0039] First, it should be noted that in the timing diagrams of the accompanying drawings, a high level can represent a conducting state, and a low level can represent a disconnected state.

[0040] Based on the aforementioned technical problems mentioned in the background art, in a first aspect, at least one embodiment of this disclosure provides a display driving circuit that can be used to drive display panels such as LTPO+ display panels. This circuit can increase the duty cycle during the display process, i.e., the proportion of the duration during which the pixel circuit and the light emission signal are connected in the entire display process, thereby improving the eye protection effect of the display panel.

[0041] The pixel circuits of the display panel driven by the display driving circuit have independent driving transistor threshold voltage (Vth) compensation paths and display data (data) writing paths, and the driving transistor threshold voltage compensation path can maintain the written charge within a preset number of frames. For example, please refer to the appendix. Figure 1 and attached Figure 2 The examples illustrate the pixel circuits of an LTPO display panel with an 8T1C architecture and an LTPO+ display panel with a 6T2C architecture. The former shares the same driving transistor threshold voltage compensation path and display data writing path, while the latter has independent driving transistor threshold voltage compensation path and display data writing path, which can achieve faster charging. This circuit has only 6 TFTs, which is more friendly to small and medium-sized OLED designs and saves more layout space.

[0042] For example, the display driving circuit can be used to drive an attached... Figure 2 The display panel shown. Next, refer to the attached... Figure 3 The timing diagram and appendix shown Figure 4 The stage state diagram shown below is for the attached Figure 2The operation of the pixel circuit of the display panel shown is described within a display frame (e.g., a refresh frame). Initialization Phase ①: First, turn on T1 to reset N1 and C1, then turn on T6 and T4 to reset N3 and N4. Vth Compensation Phase ②: Turn off T6, turn on T5, reset points N2 and N3, and perform Vth compensation. At this time, N1 - N3 = Vth, so the voltage at point N3 is Vinit1 - Vth. Data Writing Phase ③: Turn off T5, then turn off T1, turn on T2 to charge point N1. At this time, the voltage at point N3 is the voltage at the previous moment plus the voltage change at point N1 = Vinit1 - Vth + a(data - Vinit). Stage 4: Turn off T4 and T2, turn on EM2 and EM1, and the light begins to shine. At this time, the voltage at point N3 is Vs, so the voltage change at point N3 is Vs - (Vinit1 - Vth + a(data - Vinit)). The corresponding voltage at point N1 is data + Vs - (Vinit1 - Vth + a(data - Vinit)) = Vs + (1 - a)(data - Vinit1) + Vth. The corresponding current formula is: Id = 1 / 2 × u × Cox × W / L × (Vgs - Vth)^2 = k / 2(1 - a)(Data - Vinit1)^2.

[0043] The display driving circuit is configured to: in response to the current frame not being a preset number of frames away from the previous threshold voltage compensation, disconnect the light emission signal of the pixel circuit during a first duration at the beginning of the current frame, and write display data to the pixel circuit, and then turn on the light emission signal of the pixel circuit after the first duration; in response to the current frame being a preset number of frames away from the previous threshold voltage compensation, disconnect the light emission signal of the pixel circuit during a second duration at the beginning of the current frame, and sequentially initialize the pixel circuit, perform threshold voltage compensation for the driving transistor, and write display data, and then turn on the light emission signal of the pixel circuit after the second duration; wherein the second duration is longer than the first duration.

[0044] Initializing the pixel circuit may include performing a global reset (RestP) and a row reset (RestH) on the pixel circuit. (See attached...) Figure 2 Taking the pixel circuit of the display panel shown as an example, turning on T1 can perform a global reset (RestP) on the pixel circuit, and turning on T4 can perform a row reset (RestH) on the pixel circuit. It should be understood that, in response to the current frame not reaching a preset number of frames since the last threshold voltage compensation, both a global reset (RestP) and a row reset (RestH) are performed on the pixel circuit within the first duration of the current frame.

[0045] In other words, when the display driving circuit can still maintain its charge after the previous threshold voltage compensation, it no longer initializes and compensates the pixel circuit. Instead, it writes the display data and directly turns on the light emission signal of the pixel circuit. This reduces the disconnection time of the light emission signal in some display frames (e.g., refresh frames, i.e., display frames where the pixel circuit maintains its charge after threshold voltage compensation). In other words, the time originally used for initialization and threshold voltage compensation is increased to the time when the light emission signal is turned on, thereby increasing the duty cycle of the pixel circuit and improving the eye protection effect of the display panel.

[0046] In other words, the display driving circuit initializes and performs threshold voltage compensation on the pixel circuit when it cannot retain charge after the previous threshold voltage compensation, and then conducts the light emission signal of the pixel circuit after writing the display data.

[0047] Taking the threshold voltage compensation path of the driving transistor as an example that it can retain the written charge within n (n is an integer greater than 1) frames, in the mn (m is an integer not less than 1) refresh frame, the first disconnection time of the light emission signal (i.e. the duration of the first pluse, each disconnection of the light emission signal can form a pluse) is the second duration, and the first disconnection time of the light emission signal in other refresh frames is the first duration.

[0048] With attachment Figure 2 Taking the pixel circuit shown as an example, this pixel circuit is an all-oxide circuit with excellent charge retention capability. This pixel circuit is a discrete circuit, with Vth compensation and Data writing performed separately. After Vth compensation is performed by driving switch T3, it can maintain charge for multiple frames without further compensation, and there is no need to use Vinit2 to reset point N3, thus maintaining charge for multiple frames. Therefore, in display frames where Vth compensation and N3 point reset are not required by driving switch T3 (e.g., refresh frames), i.e., when the current frame is less than a preset number of frames since the last threshold voltage compensation, the attached... Figure 3 In the timing sequence shown, stages ① and ② can be removed to obtain the appendix. Figure 5 The timing sequence shown indicates the display frame (e.g., refresh frame) where Vth compensation or N3 point reset is required for driving switch T3. This frame is the current frame after a preset number of frames since the last threshold voltage compensation. Figure 3 The timing of the pixel circuit is shown.

[0049] From the appendix Figure 3 and attached Figure 5 The timing sequence shown indicates that... Figure 5 The timing diagram shows the porch region relative to the attached region. Figure 3 Shortening means that the duration of the light emission signals EM (1, 2) being off is shortened, the duty cycle is increased, and the eye protection effect is enhanced.

[0050] In one possible implementation, in the Direct Current Dimming (DC) mode, the light emission signal of the pixel circuit is disconnected at least once after the first duration or the second duration, and the duration of each disconnection of the light emission signal of the pixel circuit is less than the first duration.

[0051] If the current frame is less than a preset number of frames away from the previous threshold voltage compensation, the light emission signal of the pixel circuit will be disconnected at least once after the first duration (i.e., within the remaining duration of the current frame excluding the first duration), and the duration of each disconnection of the light emission signal of the pixel circuit will be less than the first duration.

[0052] If the current frame is a preset number of frames away from the last threshold voltage compensation, then the light emission signal of the pixel circuit will be disconnected at least once after the second duration (i.e., within the remaining duration of the current frame excluding the second duration), and the duration of each disconnection of the light emission signal of the pixel circuit will be less than the first duration.

[0053] This implementation disconnects the light emission signal of the pixel circuit at least once during the light emission stage, which can optimize the SVM flicker index of the pixel circuit and improve the display effect.

[0054] Optionally, a row reset (RestH) is performed on the pixel circuit during the duration of each disconnection of the pixel circuit's light-emitting signal after the first or second duration. If the pixel circuit's light-emitting signal is disconnected twice after the first or second duration, and a row reset (RestH) is performed on the pixel circuit during the duration of each disconnection, then combining the global reset (RestP) and row reset (RestH) performed on the pixel circuit during the first or second duration, 1P3H (i.e., one global reset (RestP) and three row resets (RestH) within a display frame (e.g., a refresh frame) can be achieved, thereby improving the display panel's display effect and eye protection effect. If a row reset (RestH) is performed on the pixel circuit during the duration of each disconnection of the pixel circuit's light-emitting signal after the first or second duration, the duration of each disconnection can be set to the minimum duration required to meet the row reset (RestH) requirement; thus, while achieving the above-mentioned effects from at least one disconnection, the duty cycle (Duty) can be maximized.

[0055] In another possible implementation, in Pulse Width Modulation Dimming (PWM) mode, the duration of at least one disconnection of the light emission signal of the pixel circuit after the first duration or the second duration is extended, and the extended disconnection duration is less than the first duration.

[0056] In PWM mode, the pixel circuit will exhibit a high-frequency alternating sequence of turning on and off the light emission signal EM during the light emission phase, that is, the EM will be turned off multiple times at high frequency during the light emission phase.

[0057] If the current frame is less than a preset number of frames away from the previous threshold voltage compensation, then the disconnection duration of the light emission signal of the pixel circuit after the first duration is extended, and the extended disconnection duration is less than the first duration.

[0058] If the current frame is at least a preset number of frames away from the previous threshold voltage compensation, then the disconnection duration of the light emission signal of the pixel circuit after the second duration is extended, and the extended disconnection duration is less than the first duration.

[0059] This implementation extends the at least one disconnection time of the light-emitting signal during the light-emitting phase, which can achieve SWM optimization of the pixel circuit and meet the one-wide-multiple-narrow timing sequence of the disconnection time in PWM mode, thereby improving the display effect.

[0060] Optionally, during the extended disconnection period following the first or second duration of the pixel circuit's light emission signal, a row reset (RestH) is performed on the pixel circuit. If a row reset (RestH) is performed on the pixel circuit during each extended disconnection period, the extended disconnection period can be set to the minimum duration required to meet the row reset (RestH) requirement, which is also greater than the duration before the extension. If the two disconnection periods following the first duration of the pixel circuit's light emission signal are extended, and a row reset (RestH) is performed on the pixel circuit during each extended disconnection period, then combining the global reset (RestP) and row reset (RestH) performed on the pixel circuit during the first or second duration, 1P3H (i.e., one global reset (RestP) and three row resets (RestH) within a display frame (e.g., a refresh frame) can be achieved for the pixel circuit, thereby improving the display effect and eye protection effect of the display panel. If the pixel circuit is subjected to a row reset (RestH) during each extended disconnection period, the extended disconnection period can be set to the minimum length that meets the row reset (RestH) requirement. This minimum length is also greater than the length before the extension. In this way, in addition to achieving the above-mentioned effects of extending the disconnection period, the duty cycle (Duty) can be increased as much as possible.

[0061] In the two embodiments described above, at least one row reset performed on the pixel circuit after the first or second duration can be evenly distributed within the remaining duration of the current frame after the first or second duration. This makes the timing of each row reset more reasonable, and the effect after the reset is maintained well, further improving the overall display effect and eye protection effect within the display frame (e.g., refresh frame). For example, in DC mode, the duration of at least one disconnection of the light emission signal of the pixel circuit after the first or second duration (each disconnection performs a row reset on the pixel circuit) is equal, and this at least one disconnection divides the remaining duration of the current frame after the first or second duration into multiple equal durations. For example, in PWM mode, taking a refresh frame's light emission signal as including x pluses, and extending the two disconnection durations of the pixel circuit's light emission signal after the first duration or the second duration as an example, the duration of the first pluse of the refresh frame is the first duration or the second duration, the durations of the x / 3+1 and 2x / 3+1 pluses are both f, and the durations of the remaining pluses are (Vtotal×(1-duty)-(d+2f)) / (x-3), where Vtotal is the total duration of the refresh frame, and duty is the refresh frame's duty cycle, i.e., the proportion of the light emission signal's on duration to the total refresh frame duration.

[0062] Please refer to the appendix. Figure 6 The example shows a timing diagram of a pixel circuit obtained by combining the above-described embodiments. In this example, the first duration is e, the second duration is d; the charge after Vth compensation can be maintained for 3 frames, that is, Vth compensation is performed once every 3 frames, and the duration for the first disconnection of the light emission signal EM in the refresh frame where Vth compensation is performed is d.

[0063] In DC and PWM modes, the duration of the first disconnection of the EM light signal in the refresh frame for Vth compensation is d, and the duration of the first disconnection of the EM light signal in the subsequent two refresh frames is e.

[0064] In DC mode, the light emission signal EM of each refresh frame is disconnected twice more within the remaining time after the first disconnection ends, and the two disconnections are evenly distributed within the remaining time. That is, the two disconnections divide the remaining time into three conduction durations with equal durations, and the durations of the two disconnections are also equal.

[0065] In PWM mode, the light signal EM is disconnected 18 times per refresh frame and turned on after each disconnection, realizing a high-frequency alternating cycle of disconnection and turn-on; the duration of the first disconnection is extended to d or e, and the duration of the 7th and 15th disconnections is extended to f.

[0066] Figure 6 In EM, length d is pluse, which can be corresponding to the appendix. Figure 3 In the stages ①②③; in EM, a pluse of length e can correspond to the appended... Figure 3 Stage ③ in the process; it should be understood that, Figure 6 The pluse of length d also includes the conduction time. Figure 6 The three disconnections of 1P3H during the refresh frame are not shown, so this detail is not shown in the figure. Figure 6 In the middle, the high level of EM can correspond to the attached Figure 3 In the diagram, EM1 and EM2 are at high levels, indicating that the light emission signal is on; the low level of EM corresponds to the attached... Figure 3 If both EM1 and EM2 are at low level, or if EM1 is at high level and EM2 is at low level, it indicates that the light emission signal is off.

[0067] It should be understood that if the pixel circuit's light emission signal does not require 1P3H, then in DC mode, the last two disconnections of each refresh frame can be deleted, that is, the light emission signal EM is kept continuously on after the first disconnection; then in PWM mode, after the first disconnection, each refresh frame can extend the duration of more or fewer disconnections, and the number and the extended duration are not constrained by RestH.

[0068] The display driving circuit provided in this embodiment is used to drive a display panel. The display panel has independent driving transistor threshold voltage compensation paths and display data writing paths. The driving transistor threshold voltage compensation path can maintain the written charge within a preset number of frames. Therefore, in response to the current frame not reaching the preset number of frames since the previous threshold voltage compensation, the display driving circuit disconnects the light emission signal of the pixel circuit during a first duration at the beginning of the current frame and writes display data to the pixel circuit. After the first duration, the light emission signal of the pixel circuit is turned on. In response to the current frame reaching the preset number of frames since the previous threshold voltage compensation, the light emission signal of the pixel circuit is disconnected during a second duration at the beginning of the current frame, and the pixel circuit is initialized, driving transistor threshold voltage compensation is performed, and display data is written sequentially. After the second duration, the light emission signal of the pixel circuit is turned on. The second duration is longer than the first duration. In other words, when the display driving circuit can still maintain its charge after the previous threshold voltage compensation, it no longer initializes and compensates the pixel circuit. Instead, it writes the display data and directly turns on the light emission signal of the pixel circuit. This reduces the disconnection time of the light emission signal in some display frames (e.g., refresh frames, i.e., display frames where the pixel circuit maintains its charge after threshold voltage compensation). In other words, the time originally used for initialization and threshold voltage compensation is increased to the time when the light emission signal is turned on, thereby increasing the duty cycle of the pixel circuit and improving the eye protection effect of the display panel.

[0069] In some embodiments of this disclosure, the display driving circuit is configured to: determine the display data written in the current frame based on a first Gamma curve in response to the current frame not reaching a preset number of frames since the previous threshold voltage compensation; and determine the display data written in the current frame based on a second Gamma curve in response to the current frame reaching a preset number of frames since the previous threshold voltage compensation; wherein the duty cycle corresponding to the first duration and the display brightness presented by the display data determined based on the first Gamma curve are the same as the duty cycle corresponding to the second duration and the display brightness presented by the display data determined based on the second Gamma curve.

[0070] The Gamma curve is used to characterize the mapping relationship between the grayscale values ​​of pixels in the image displayed on the display panel and the display data of the pixel circuit of the display panel.

[0071] The duty cycle (Duty) of refresh frames with the first and second initial disconnection durations differs. This Duty affects the display panel's brightness, causing a sudden brightness change during the initial disconnection duration switch. This embodiment sets different Gamma curves for the first and second durations, allowing the refresh frames with the two Duties to compensate for the display data through the Gamma curves, achieving consistent brightness and preventing sudden brightness changes during the initial disconnection duration switch.

[0072] Optionally, in this embodiment, the display driving circuit is configured to: in response to the current frame being a hold frame, disconnect the light emission signal of the pixel circuit during the first duration or the second duration at the beginning of the current frame, perform a row reset on the pixel circuit, and turn on the light emission signal of the pixel circuit after the first duration or the second duration; wherein, the duration for which the light emission signal of the pixel circuit is disconnected at the beginning of the hold frame is the same as the duration for which the light emission signal of the pixel circuit is disconnected at the beginning of the last refresh frame before the hold frame.

[0073] Please refer to the appendix. Figure 7 An exemplary timing diagram of the pixel circuitry in this optional example is shown. In this optional example, the initial disconnection duration of the light emission signal in the second refresh frame is e, and the initial disconnection duration of the light emission signal in the subsequent hold frame is e, but no display data is written during the initial disconnection duration of the light emission signal in the hold frame. For example, no additional data is written during the initial disconnection duration of the light emission signal in the hold frame. Figure 5 Stage ③ is shown.

[0074] It should be understood that the duration of refresh frames and hold frames remains consistent with each other after the initial disconnection.

[0075] The second Gamma curve can be obtained by tuning the first Gamma curve. Alternatively, it can be the Gamma value of the first Gamma curve plus an offset, where the offset is determined by the difference in duty levels.

[0076] In this embodiment, different Gamma curves are used to compensate for the inter-frame brightness differences caused by different duty cycles, achieving consistent display brightness for display frames (e.g., refresh frames) with initial disconnection durations of the first and second durations. Since the display brightness in this embodiment is determined by both the display data and the duty cycle, in hold frames (where the display data remains unchanged, i.e., no display data is written within the hold frame), the duty cycle needs to be kept consistent with the last refresh frame (i.e., the last display frame where display data was written). As the above analysis shows, this optional example achieves the effect of maintaining constant brightness in the hold frame relative to the previous refresh frame by keeping the initial disconnection duration of the light emission signal in the hold frame consistent with the initial disconnection duration of the light emission signal in the last refresh frame, thus improving the inter-frame display effect.

[0077] For example, in this optional example, the display driving circuit is configured to: in response to the current frame being a refresh frame and the next frame being a hold frame, disconnect the light emission signal of the pixel circuit during the initial second duration of the current frame, and sequentially initialize the pixel circuit, compensate the threshold voltage of the driving transistor, and write display data, and then turn on the light emission signal of the pixel circuit after the second duration.

[0078] It should be understood that the duration of refresh frames and hold frames remains consistent with each other after the initial disconnection.

[0079] Please refer to the appendix. Figure 8 An exemplary timing diagram of the pixel circuitry in this optional example is shown. In this optional example, the initial disconnection duration of the light emission signal in the second refresh frame is d, and the initial disconnection duration of the light emission signal in the subsequent hold frame is d, but initialization, Vth compensation, and display data writing are not performed within the initial disconnection duration of the light emission signal in the hold frame. For example, no additional data is performed within the initial disconnection duration of the light emission signal in the hold frame. Figure 3 The stages ①②③ are shown.

[0080] Since no display data is written in the hold frame, this optional example forces Vth compensation and display data writing in the last refresh frame before the hold frame. This makes the first disconnection time of the light emission signal in the refresh frame the second duration, and makes the retention effect of the display data in the hold frame better, thereby making the display panel display effect and eye protection effect better in the hold frame.

[0081] In some embodiments of this disclosure, the display driving circuit is configured to: in response to the current frame being a hold frame, disconnect the light emission signal of the pixel circuit during the third duration at the beginning of the current frame, perform a row reset on the pixel circuit, and turn on the light emission signal of the pixel circuit after the third duration; wherein the third duration is less than the first duration.

[0082] It should be understood that the duration of refresh frames and hold frames remains consistent with each other after the initial disconnection.

[0083] This embodiment does not use the Gamma curve to compensate for the differences in display brightness between different refresh frames of Duty, but other methods can be used to compensate for the differences in display brightness between different refresh frames of Duty.

[0084] Please refer to the appendix. Figure 9 and attached Figure 10 The example illustrates a timing diagram of the pixel circuit in this embodiment. In this embodiment, the initial disconnection duration of the light emission signal in the second refresh frame is e, and the initial disconnection duration of the light emission signal in the subsequent hold frame is m. This disconnection duration is used for row reset (RestH). The disconnection durations for the two RestH operations after the hold frame are also m, where m can be the same as the pluse duration of the RestH operation in the refresh frame. In other words, the initial disconnection duration within the hold frame is the same as the subsequent RestH disconnection duration, thereby further increasing the duty cycle of the hold frame. For example, the initial disconnection duration of the light emission signal in the hold frame is used for row reset (RestH). Figure 3 The operation of stage ③ shown is RestH.

[0085] The hold frame keeps the displayed data unchanged, meaning that no display data needs to be written within the hold frame. Therefore, no display data needs to be written within the first time the light signal of the hold frame is disconnected, and a row reset (RestH) can be performed. Thus, this time can be shortened to meet the minimum time required for performing a row reset (RestH), thereby further increasing the duty cycle (Duty) of the hold frame.

[0086] According to a second aspect of the present disclosure, a display driver chip is provided, the display driver chip including the display driver circuit as described in any one of the first aspects.

[0087] According to a third aspect of the present disclosure, a display driving method is provided, wherein the pixel circuit of the display panel driven by the method has mutually independent driving transistor threshold voltage compensation paths and display data writing paths, and the driving transistor threshold voltage compensation paths are capable of maintaining the written charge within a preset number of frames. Please refer to the appendix. Figure 11 The display driving method includes: In step S1101, in response to the fact that the threshold voltage compensation in the previous frame did not reach a preset number of frames, the light emission signal of the pixel circuit is disconnected during the first duration of the current frame, and display data is written to the pixel circuit. After the first duration, the light emission signal of the pixel circuit is turned on.

[0088] In step S1102, in response to the current frame being a preset number of frames away from the previous threshold voltage compensation, the light emission signal of the pixel circuit is disconnected during the second duration at the beginning of the current frame, and the pixel circuit is initialized, the threshold voltage compensation of the driving transistor is performed, and the display data is written in sequence. After the second duration, the light emission signal of the pixel circuit is turned on. Wherein, the second duration is longer than the first duration.

[0089] In some possible embodiments of this disclosure, the method further includes: In response to the fact that the current frame is less than a preset number of frames away from the previous threshold voltage compensation, the display data written in the current frame is determined based on the first Gamma curve; In response to the current frame being a preset number of frames since the last threshold voltage compensation, the display data written in the current frame is determined based on the second Gamma curve; The duty cycle corresponding to the first duration and the display brightness presented by the display data determined based on the first Gamma curve are the same as the duty cycle corresponding to the second duration and the display brightness presented by the display data determined based on the second Gamma curve.

[0090] In some possible embodiments of this disclosure, the method further includes: In response to the fact that the threshold voltage compensation for the current frame did not reach a preset number of frames, the pixel circuit is also reset during the first duration of the current frame.

[0091] In some possible embodiments of this disclosure, the method further includes: In response to the current frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the first or second duration at the beginning of the current frame, and the pixel circuit is row-reset. After the first or second duration, the light emission signal of the pixel circuit is turned on. The duration of the light emission signal that initially disconnects the pixel circuit in the hold frame is the same as the duration of the light emission signal that initially disconnects the pixel circuit in the last refresh frame before the hold frame.

[0092] In some possible embodiments of this disclosure, the method further includes: In response to the current frame being a refresh frame and the next frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the second duration at the beginning of the current frame, and the pixel circuit is initialized, the threshold voltage of the driving transistor is compensated, and the display data is written in sequence. After the second duration, the light emission signal of the pixel circuit is turned on.

[0093] In some possible embodiments of this disclosure, the method further includes: In response to the current frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the third duration at the beginning of the current frame, and the pixel circuit is row-reset. After the third duration, the light emission signal of the pixel circuit is turned on. The third duration is shorter than the first duration.

[0094] In some possible embodiments of this disclosure, the method further includes: In the DC constant light emission dimming mode, the light emission signal of the pixel circuit is disconnected at least once after the first duration or the second duration, and the duration of each disconnection of the light emission signal of the pixel circuit is less than the first duration.

[0095] In some possible embodiments of this disclosure, the method further includes: The pixel circuit is reset during the duration of each disconnection of the light emission signal.

[0096] In some possible embodiments of this disclosure, the method further includes: In pulse width modulation (PWM) dimming mode, the duration of at least one disconnection of the light emission signal of the pixel circuit after the first duration or the second duration is extended, and the extended disconnection duration is less than the first duration.

[0097] In some possible embodiments of this disclosure, the method further includes: During the disconnection period following the first or second duration of each extended period of the light emission signal of the pixel circuit, the pixel circuit is reset.

[0098] In some possible embodiments of this disclosure, the method further includes: At least one row reset of the pixel circuit after the first duration or the second duration is evenly distributed within the remaining duration of the current frame after the first duration or the second duration.

[0099] According to a fifth aspect of the present disclosure, a computer program product is provided, including a computer program / instructions that, when executed by a processor, implement the method described in the third aspect.

[0100] Please refer to the appendix. Figure 12This disclosure provides an electronic device in some embodiments, the device including a memory and a processor, the memory being used to store computer instructions executable on the processor, and the processor being used to process material based on the method described in the third aspect when executing the computer instructions.

[0101] Some embodiments of this disclosure provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method described in the third aspect.

[0102] The various component embodiments of this disclosure can be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof.

[0103] It should be understood that although the steps in the flowcharts of the accompanying figures are shown sequentially as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the accompanying figures may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the sub-steps or stages of other steps.

[0104] In this disclosure, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.

[0105] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0106] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A display driving circuit, characterized in that, The pixel circuits of the display panel driven by the display driving circuit have independent driving transistor threshold voltage compensation paths and display data writing paths, and the driving transistor threshold voltage compensation paths can maintain the written charge within a preset number of frames. The display driving circuit is used for: In response to the fact that the threshold voltage compensation in the previous frame did not reach a preset number of frames, the light emission signal of the pixel circuit is disconnected during the first duration of the current frame, and display data is written to the pixel circuit. After the first duration, the light emission signal of the pixel circuit is turned on. In response to the current frame being a preset number of frames away from the previous threshold voltage compensation, the light emission signal of the pixel circuit is disconnected during the second duration at the beginning of the current frame, and the pixel circuit is initialized, the threshold voltage compensation of the driving transistor is performed, and the display data is written in sequence. After the second duration, the light emission signal of the pixel circuit is turned on. Wherein, the second duration is longer than the first duration.

2. The display driving circuit according to claim 1, characterized in that, The display driving circuit is used for: In response to the fact that the current frame is less than a preset number of frames away from the previous threshold voltage compensation, the display data written in the current frame is determined based on the first Gamma curve; In response to the current frame being a preset number of frames since the last threshold voltage compensation, the display data written in the current frame is determined based on the second Gamma curve; The duty cycle corresponding to the first duration and the display brightness presented by the display data determined based on the first Gamma curve are the same as the duty cycle corresponding to the second duration and the display brightness presented by the display data determined based on the second Gamma curve.

3. The display driving circuit according to claim 2, characterized in that, The display driving circuit is used for: In response to the fact that the threshold voltage compensation for the current frame did not reach a preset number of frames, the pixel circuit is also reset during the first duration of the current frame.

4. The display driving circuit according to claim 3, characterized in that, The display driving circuit is used for: In response to the current frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the first or second duration at the beginning of the current frame, and the pixel circuit is row-reset. After the first or second duration, the light emission signal of the pixel circuit is turned on. The duration of the light emission signal that initially disconnects the pixel circuit in the hold frame is the same as the duration of the light emission signal that initially disconnects the pixel circuit in the last refresh frame before the hold frame.

5. The display driving circuit according to claim 4, characterized in that, The display driving circuit is used for: In response to the current frame being a refresh frame and the next frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the second duration at the beginning of the current frame, and the pixel circuit is initialized, the threshold voltage of the driving transistor is compensated, and the display data is written in sequence. After the second duration, the light emission signal of the pixel circuit is turned on.

6. The display driving circuit according to claim 1, characterized in that, The display driving circuit is used for: In response to the current frame being a hold frame, the light emission signal of the pixel circuit is disconnected during the third duration at the beginning of the current frame, and the pixel circuit is row reset. After the third duration, the light emission signal of the pixel circuit is turned on. The third duration is shorter than the first duration.

7. The display driving circuit according to claim 3, characterized in that, The display driving circuit is used for: In the DC constant light emission dimming mode, the light emission signal of the pixel circuit is disconnected at least once after the first duration or the second duration, and the duration of each disconnection of the light emission signal of the pixel circuit is less than the first duration.

8. The display driving circuit according to claim 7, characterized in that, The display driving circuit is used for: The pixel circuit is reset during the duration of each disconnection of the light emission signal.

9. The display driving circuit according to claim 3, characterized in that, The display driving circuit is used for: In pulse width modulation (PWM) dimming mode, the duration of at least one disconnection of the light emission signal of the pixel circuit after the first duration or the second duration is extended, and the extended disconnection duration is less than the first duration.

10. The display driving circuit according to claim 9, characterized in that, The display driving circuit is used for: During the disconnection period following the first or second duration of each extended period of the light emission signal of the pixel circuit, the pixel circuit is reset.

11. The display driving circuit according to claim 8 or 10, characterized in that, The display driving circuit is used for: At least one row reset of the pixel circuit after the first duration or the second duration is evenly distributed within the remaining duration of the current frame after the first duration or the second duration.

12. A display driver chip, characterized in that, The display driver chip includes the display driver circuit as described in any one of claims 1 to 11.

13. A display driving method, characterized in that, The pixel circuit of the display panel driven by the method has independent driving transistor threshold voltage compensation paths and display data writing paths, and the driving transistor threshold voltage compensation paths can maintain the written charge within a preset number of frames. The display driving method includes: In response to the fact that the threshold voltage compensation in the previous frame did not reach a preset number of frames, the light emission signal of the pixel circuit is disconnected during the first duration of the current frame, and display data is written to the pixel circuit. After the first duration, the light emission signal of the pixel circuit is turned on. In response to the current frame being a preset number of frames away from the previous threshold voltage compensation, the light emission signal of the pixel circuit is disconnected during the second duration at the beginning of the current frame, and the pixel circuit is initialized, the threshold voltage compensation of the driving transistor is performed, and the display data is written in sequence. After the second duration, the light emission signal of the pixel circuit is turned on. Wherein, the second duration is longer than the first duration.

14. A computer program product comprising a computer program / instructions, characterized in that, When the computational program / instructions are executed by the processor, they implement the steps of the method of claim 13.

15. An electronic device, characterized in that, The device includes a memory and a processor, the memory being used to store computer instructions that can run on the processor, and the processor being used to implement the method of claim 13 when executing the computer instructions.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method of claim 13.

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