A novel AMOLED pixel driving circuit and driving method

Abstract

This invention provides a novel AMOLED pixel driving circuit and driving method, including a light-emitting element, a control module, a threshold voltage extraction module, and a driving module. The control module, threshold voltage extraction module, and driving module share a second switching transistor. The control module and driving module also share a first capacitor. The driving module and threshold voltage extraction module share a seventh switching transistor. Compared with the prior art, this invention controls the conduction time and conduction current of the light-emitting element through the voltage signal accessed by the control module and the shared switching transistor. This enables more precise grayscale control within a limited frame time, significantly improving grayscale levels and display detail. The threshold voltage extraction module eliminates the influence of threshold voltage changes on the light-emitting current, effectively suppressing current changes caused by process deviations or aging, ensuring the accuracy and stability of the light-emitting current, and improving display uniformity and reliability.

Description

Technical Field

[0001] This invention relates to the field of integrated circuit technology, and in particular to a novel AMOLED pixel driving circuit and driving method. Background Technology

[0002] With the continuous development of display technology, Active Matrix Organic Light-Emitting Diode (AMOLED) has become one of the mainstream solutions in the high-end display field due to its advantages such as high contrast, wide viewing angle, thinness, flexibility, and low power consumption. However, with the increase in resolution and the expansion of display size, higher requirements are placed on the precision, stability, and energy efficiency of pixel driving circuits.

[0003] While the traditional 2T1C pixel driving circuit can theoretically meet the driving requirements of AMOLED displays, its luminous current is limited by the characteristics of the components in the circuit. This is due to variations in the threshold voltage drift of the thin-film transistor (TFT), the shift in the carrier mobility of the driving TFT, and the decay of the threshold voltage of the organic light-emitting diode (OLED). Therefore, this issue should be taken into account in the actual pixel driving circuit design, especially in low grayscale display scenarios, where these issues are more likely to lead to uneven brightness, color shift, and other phenomena, seriously affecting the visual experience.

[0004] Current AMOLED pixel driving architectures are mainly divided into voltage-programmable and current-programmable types. Voltage-programmable architectures are simple and have a high aperture ratio, but are susceptible to the effects of thin-film transistor threshold voltage inhomogeneity and aging shift. Current-programmable architectures can compensate for threshold voltage variations and achieve better uniformity, but have slow charging speeds, higher power consumption, and extremely high requirements for data current accuracy. To maintain high resolution and high refresh rate while achieving precise grayscale control, pulse width modulation (PWM) driving methods have been widely adopted. Among them, analog PWM schemes control the emission time by adjusting the signal pulse width, achieving higher grayscale levels and helping to maintain color consistency.

[0005] However, existing analog PWM-based driving methods still have shortcomings in practical applications. Due to the small slopes of the rising and falling edges of the control signal, the proportion of the PWM waveform's on / off process to the entire light emission cycle increases significantly under the narrow pulse conditions corresponding to low grayscale levels. This leads to unstable effective light emission time, resulting in brightness fluctuations and color coordinate shifts in low grayscale areas. Furthermore, in ultra-high resolution panels, the increased signal transmission load further exacerbates the distortion of the PWM waveform, reducing display uniformity. This is especially problematic when displaying dark images, easily causing defects such as "dulling" or "flickering." Summary of the Invention

[0006] This invention provides a novel AMOLED pixel driving circuit and driving method, the purpose of which is to improve display uniformity and reliability.

[0007] To achieve the above objectives, the present invention provides a novel AMOLED pixel driving circuit, comprising: Light-emitting elements; The control module is used to control the conduction time and conduction current of the light-emitting element by receiving a voltage signal; Threshold voltage extraction module, used to extract the threshold voltage of the switching transistor; The driver module is used to drive the light-emitting element to work according to the threshold voltage of the switching transistor; The control module, threshold voltage extraction module, and drive module share a second switching transistor; The control module and the drive module also reuse a first capacitor; The drive module and the threshold voltage extraction module share a seventh switch. The first end of the light-emitting element is electrically connected to the power supply terminal; The second end of the light-emitting element is electrically connected to the output end of the driving module; Both the first control terminal and the second control terminal of the driving module are electrically connected to the output terminal of the AMOLED controller. The input terminal of the drive module is connected to the output terminal of the threshold voltage extraction module; The first input terminal of the control module is electrically connected to the output terminal of the AMOLED controller, and the second input terminal of the control module is used to receive the input voltage; The output of the control module is electrically connected to the input of the threshold voltage extraction module and the input of the drive module through a multiplexed switching transistor.

[0008] Furthermore, the control module includes: First reference voltage source; The current control unit is used to control the conduction current of the light-emitting element; The PWM generation unit is used to generate PWM pulse signals to control the on-time of the light-emitting element; The first input terminal of the current control unit is used to receive the input voltage; The second input terminal of the current control unit and the first input terminal of the PWM generation unit are both electrically connected to the output terminal of the AMOLED controller. The second input terminal of the PWM generation unit is electrically connected to the output terminal of the current control unit; The first output terminal of the PWM generation unit is electrically connected to the input terminal of the threshold voltage extraction module and the input terminal of the drive module through a multiplexed switching transistor. The second output terminal of the PWM generation unit is connected to the input terminal of the first reference voltage source.

[0009] Furthermore, the PWM generation unit includes: First switching transistor, second switching transistor, third switching transistor, fifth switching transistor, first capacitor; The gates of the first switch, the third switch, and the fifth switch are all electrically connected to the output of the AMOLED controller. The source of the first switching transistor is electrically connected to the first reference voltage source; The drain of the first switching transistor is electrically connected to the drain of the third switching transistor, the gate of the second switching transistor, and the first capacitor, respectively. The source of the second switch is electrically connected to the input terminal of the drive module and the drain of the fifth switch, respectively. The drain of the second switch is electrically connected to the source of the third switch, the source of the current control unit, and the input terminal of the threshold voltage extraction module, respectively. The source of the fifth switching transistor is used to connect a voltage signal.

[0010] Furthermore, the threshold voltage extraction module includes: Second reference voltage source, second switch, sixth switch, seventh switch, eighth switch; The drain of the second switch is electrically connected to the drain of the sixth switch, the gate of the seventh switch, and the input terminal of the drive module, respectively. The source of the second switching transistor is electrically connected to the input terminal of the drive module; The gates of the sixth and eighth switching transistors are both electrically connected to the output of the AMOLED controller. The source of the sixth switch is electrically connected to the input terminal of the drive module and the drain of the seventh switch, respectively. The drain of the eighth switch is electrically connected to the input terminal of the drive module and the source of the seventh switch, and the source of the eighth switch is electrically connected to the second reference voltage source.

[0011] Furthermore, the driver module includes: Second switch, seventh switch, ninth switch, tenth switch, eleventh switch, twelfth switch, first capacitor, second capacitor, third capacitor; The source of the second switch is electrically connected to the drain of the ninth switch, and the drain of the second switch is electrically connected to the first terminal of the second capacitor and the drain of the tenth switch. The gates of the ninth, tenth, eleventh, and twelfth switches are all electrically connected to the output of the AMOLED controller. The source of the ninth switch is connected to the second terminal of the second capacitor and the source of the twelfth switch, respectively, and grounded. The source of the tenth switching transistor is electrically connected to the first terminal of the third capacitor; The second terminal of the third capacitor is electrically connected to the source of the seventh switch, the drain of the twelfth switch, and the drain of the eighth switch, respectively.

[0012] This invention also provides a novel AMOLED pixel driving method, applied to a novel AMOLED pixel driving circuit, the method comprising: Step 1: The control module acquires the first control signal and controls the second switch transistor, which is multiplexed by the control module and the threshold voltage extraction module, to turn on, so that the new AMOLED pixel driving circuit enters the reset stage. Step 2: The control module acquires the second control signal and controls the second switch transistor multiplexed by the control module and the threshold voltage extraction module to turn off, so that the new AMOLED pixel driving circuit can enter the PWM data writing stage. Step 3: The control module acquires the third control signal. The third control signal is transmitted to the light-emitting element through the seventh switch multiplexed by the driving module and the threshold voltage extraction module. The conduction current of the light-emitting element is controlled by the third control signal so that the new AMOLED pixel driving circuit enters the pre-charging stage. Step 4: The driving module obtains the fourth control signal. The fourth control signal controls the seventh switch, which is multiplexed by the driving module and the threshold voltage extraction module, to turn on until the voltage between the second switch and the seventh switch is equal to the threshold voltage of the seventh switch, so that the new AMOLED pixel driving circuit enters the threshold voltage extraction stage. Step 5: The driving module acquires the fifth control signal. The fifth control signal controls the seventh switch, which is multiplexed by the driving module and the threshold voltage extraction module, to turn on, so that the new AMOLED pixel driving circuit enters the light-emitting stage. The voltage signal connected to the control module drives and controls the conduction current and conduction time of the light-emitting element.

[0013] Furthermore, when the new AMOLED pixel driving circuit enters the light-emitting stage, the second, seventh, ninth, tenth, eleventh, and twelfth switches in the driving module are all turned on, and the light-emitting element begins to emit light.

[0014] The above-described solution of the present invention has the following beneficial effects: This invention includes a light-emitting element, a control module for controlling the conduction time and conduction current of the light-emitting element by receiving a voltage signal, a threshold voltage extraction module for extracting the threshold voltage of a switching transistor, and a driving module for driving the light-emitting element to operate based on the threshold voltage of the switching transistor. The control module, threshold voltage extraction module, and driving module share a second switching transistor. The control module and driving module also share a first capacitor. The driving module and threshold voltage extraction module share a seventh switching transistor. Compared with the prior art, this invention controls the conduction time and conduction current of the light-emitting element by receiving a voltage signal from the control module and using the shared switching transistor. This allows for finer grayscale control within a limited frame time, significantly improving grayscale levels and display detail. The threshold voltage extraction module eliminates the influence of threshold voltage changes on the light-emitting current, effectively suppressing current changes caused by process deviations or aging, ensuring the accuracy and stability of the light-emitting current, and improving display uniformity and reliability.

[0015] Other beneficial effects of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the novel AMOLED pixel driving circuit in an embodiment of the present invention; Figure 2 This is a flowchart of the novel AMOLED pixel driving method in an embodiment of the present invention; Figure 3 This is a flowchart illustrating the working process of the novel AMOLED pixel driving method in an embodiment of the present invention. Figure 4 This is a waveform diagram of the light-emitting current of the light-emitting element in PWM driving mode in an embodiment of the present invention; Figure 5 This is a waveform diagram of the luminous current of the light-emitting element in PAM driving mode in an embodiment of the present invention. Detailed Implementation

[0017] To make the technical problems, solutions, and advantages of this invention clearer, a detailed description will be provided below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0018] In the description of this invention, it should be noted that the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a locking connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0021] This invention addresses existing problems by providing a novel AMOLED pixel driving circuit and driving method.

[0022] Embodiments of the present invention provide a novel AMOLED pixel driving circuit, comprising: Light-emitting elements; The control module is used to control the conduction time and conduction current of the light-emitting element by receiving a voltage signal; Threshold voltage extraction module, used to extract the threshold voltage of the switching transistor; The driver module is used to drive the light-emitting element to work according to the threshold voltage of the switching transistor; The control module, threshold voltage extraction module, and drive module share a second switching transistor; The control module and the drive module also reuse a first capacitor; The drive module and the threshold voltage extraction module share a seventh switch. The first end of the light-emitting element is electrically connected to the power supply terminal; The second end of the light-emitting element is electrically connected to the output end of the driving module; Both the first control terminal and the second control terminal of the driving module are electrically connected to the output terminal of the AMOLED controller. The input terminal of the drive module is connected to the output terminal of the threshold voltage extraction module; The first input terminal of the control module is electrically connected to the output terminal of the AMOLED controller, and the second input terminal of the control module is used to receive the input voltage; The output of the control module is electrically connected to the input of the threshold voltage extraction module and the input of the drive module through a multiplexed switching transistor.

[0023] It should be noted that the light-emitting element used in the embodiments of the present invention can be a light-emitting diode or an organic light-emitting diode.

[0024] Specifically, such as Figure 1 As shown, the control module includes: First reference voltage source V ref1 ; The current control unit is used to control the conduction current of the light-emitting element; The PWM generation unit is used to generate PWM pulse signals to control the on-time of the light-emitting element; The first input terminal of the current control unit is used to receive the input voltage; The second input terminal of the current control unit and the first input terminal of the PWM generation unit are both electrically connected to the output terminal of the AMOLED controller. The second input terminal of the PWM generation unit is electrically connected to the output terminal of the current control unit; The first output terminal of the PWM generation unit is electrically connected to the input terminal of the threshold voltage extraction module and the input terminal of the drive module through a multiplexed switching transistor. The second output terminal of the PWM generation unit is connected to the first reference voltage source V. ref1 The input terminal is connected.

[0025] Specifically, such as Figure 1 As shown, the PWM generation unit includes: First switch transistor T1, second switch transistor T2, third switch transistor T3, fifth switch transistor T5, first capacitor C1; The gates of the first switch T1, the third switch T3, and the fifth switch T5 are all electrically connected to the output of the AMOLED controller. The source of the first switching transistor T1 is electrically connected to the first reference voltage source Vref1; The drain of the first switching transistor T1 is electrically connected to the drain of the third switching transistor T3, the gate of the second switching transistor T2, and the first capacitor C1, respectively. The source of the second switch T2 is electrically connected to the input terminal of the drive module and the drain of the fifth switch T5, respectively. The drain of the second switch T2 is electrically connected to the source of the third switch T3, the source of the current control unit, and the input terminal of the threshold voltage extraction module, respectively. The source of the fifth switching transistor T5 is used to connect a voltage signal.

[0026] In this embodiment of the invention, the working principle of the PWM generation unit is as follows: The AMOLED controller applies a control signal SCAN(N) to the gate of the first switch T1, turning on the first switch T1. The slope signal Sweep rises linearly from a low level, and through the coupling effect of the first capacitor C1, the B-node potential between the first switch T1 and the second switch T2 gradually rises until the B-node potential reaches the threshold voltage of the second switch T2, turning on the second switch T2. The B-node potential is then charged through the first capacitor C1 to the first reference voltage source V. ref1 ; The AMOLED controller applies a control signal SCAN(N+) to the gates of the third switch T3 and the fifth switch T5 to control the conduction of the third switch T3 and the fifth switch T5. The voltage at node A between the source of the second switch T2 and the source of the fifth switch T5 is pulled down to the voltage signal DATA_PWM connected to the source of the fifth switch T5. The first capacitor C1 discharges through the second switch T2 to the threshold voltage extraction module. The threshold voltage of the second switch T2 is stored at node B. The voltage signal DATA_PWM is connected from the source of the fifth switch T5, and flows into the light-emitting element through the second switch T2, the threshold voltage extraction module, and the driving module to control the conduction time of the light-emitting element.

[0027] Specifically, such as Figure 1 As shown, the current control unit includes a fourth switch T4. The gate of the fourth switch T4 is electrically connected to the output terminal of the AMOLED controller. The drain of the fourth switch T4 is used to receive a voltage signal. The source of the fourth switch T4 is connected to the source of the third switch T3 and the drain of the second switch T2, respectively.

[0028] In this embodiment of the invention, the working principle of the current control unit is as follows: The AMOLED controller applies a control signal V to the gate of the fourth switch T4. C1 The voltage signal is input from the drain of the fourth switch T4, and after being regulated by the fourth switch T4, it flows into the light-emitting element from the source of the fourth switch T4, the threshold voltage extraction module, and the driving module, so as to control the conduction current of the light-emitting element.

[0029] Specifically, such as Figure 1 As shown, the threshold voltage extraction module includes: Second reference voltage source V ref2 The second switch transistor T2, the sixth switch transistor T6, the seventh switch transistor T7, and the eighth switch transistor T8; The drain of the second switch T2 is electrically connected to the drain of the sixth switch T6, the gate of the seventh switch T7, and the input terminal of the drive module, respectively. The source of the second switching transistor T2 is electrically connected to the input terminal of the drive module; The gates of the sixth switch T6 and the eighth switch T8 are both electrically connected to the output of the AMOLED controller. The source of the sixth switch T6 is electrically connected to the input terminal of the drive module and the drain of the seventh switch T7, respectively. The drain of the eighth switch transistor T8 is electrically connected to the input terminal of the drive module and the source of the seventh switch transistor T7. The source of the eighth switch transistor T8 is connected to the second reference voltage source V. ref2 Electrical connection.

[0030] In this embodiment of the invention, the working principle of the threshold voltage extraction module is as follows: The AMOLED controller applies a control signal VC2 to the gates of the sixth switch T6 and the eighth switch T8 to control the sixth switch T6 and the eighth switch T8 to conduct. Since the source voltage of the seventh switch T7 is low, and the gate of the seventh switch T7 is the voltage signal DATA_PWM transmitted from the second switch T2, the seventh switch T7 conducts. The voltage at node C between the second switch T2 and the seventh switch T7 discharges through the second capacitor C2. When the voltage at node C is equal to the threshold voltage of the seventh switch T7, the seventh switch T7 closes and stops discharging. At this time, the threshold voltage of the seventh switch T7 is stored at node C.

[0031] Specifically, such as Figure 1 As shown, the driver module includes: Second switch T2, seventh switch T7, ninth switch T9, tenth switch T10, eleventh switch T11, twelfth switch T12, first capacitor C1, second capacitor C2, third capacitor C3; The source of the second switch transistor T2 is electrically connected to the drain of the ninth switch transistor T9, and the drain of the second switch transistor T2 is electrically connected to the first terminal of the second capacitor C2 and the drain of the tenth switch transistor T10. The gates of the ninth switch T9, the tenth switch T10, the eleventh switch T11, and the twelfth switch T12 are all electrically connected to the output of the AMOLED controller. The source of the ninth switch T9 is connected to the second terminal of the second capacitor C2 and the source of the twelfth switch T12, and grounded. The source of the tenth switching transistor T10 is electrically connected to the first terminal of the third capacitor C3; The second terminal of the third capacitor C3 is electrically connected to the source of the seventh switch T7, the drain of the twelfth switch T12, and the drain of the eighth switch T8, respectively.

[0032] In this embodiment of the invention, the working principle of the driver module is as follows: The AMOLED controller applies control signal VC3 to the ninth switch T9, tenth switch T10, eleventh switch T11, and twelfth switch T12 to turn them on. The slope signal Sweep starts to rise linearly from a low level. Through the coupling effect of the first capacitor C1, the potential at node B between the first switch T1 and the second switch T2 also gradually rises until the potential at node B reaches the threshold voltage of the second switch T2, causing the second switch T2 to turn on. At the same time, the ninth switch T9 turns on, and the voltage at node C discharges through the second switch T2 and the ninth switch T9, causing the seventh switch T7 to close, and the light-emitting element stops emitting light.

[0033] In this embodiment of the invention, the light emission stage is the core execution link of the entire pixel driving cycle. It undertakes the preparatory work of all the previous stages and starts to realize three functions under the trigger of VC3 signal being set to high level: constant and precise light emission of the light emission element, precise control of PWM pulse width, and negative feedback compensation of mobility. This ensures that the light emission current and light emission time are not affected by the threshold voltage drift of the second switch T2 and the third switch T3 and the change of mobility of the driving tube.

[0034] Potential change and PWM pulse width control principle: When VC3 goes high, transistors T2, T3, T8, T9, T10, and T11 conduct, activating the light-emitting circuit and causing the light-emitting element to emit light. The slope signal Sweep begins to rise linearly from low level. Through the coupling effect of the first capacitor C1, the potential at node B also gradually rises. The threshold voltage VTH2 of the second switch T2 was already stored at node B during the previous PWM data writing phase; therefore, the voltage at point B is VB = V... DATA_PWM +V TH2 +V sweep ; When the potential at node B rises to the threshold voltage of the second switch T2, the second switch T2 is triggered to turn on. At the same time, because VC3 becomes high, the eighth switch T8 remains on. At this time, the voltage stored at node C begins to discharge through the path formed by T2 and T8. Point C is the gate of the third switch T3. The voltage at point C discharges and drops, which directly causes the third switch T3 to turn off. The light-emitting circuit is then disconnected, and the light-emitting element stops emitting light. The time difference between when the light-emitting circuit is turned on by VC3 and when the circuit is turned off by the third switch T3 is the actual light-emitting time of the light-emitting element. This time is uniquely determined by the DATA_PWM data voltage (unrelated to the threshold voltage of the second switch T2), thus achieving precise modulation of the PWM pulse width. Furthermore, by utilizing the linear characteristics of the ramp signal, the rising and falling edge slopes of the PWM pulse are optimized, avoiding waveform distortion under low grayscale narrow pulses.

[0035] The principle of controlling the luminous current and compensating for it with the threshold voltage of the third switch T3: (1) When the light-emitting circuit is turned on, the third switch T3 operates in the saturation region, and the potential at its gate C point is: ; (2) Combining the formula for the saturation current of the switching transistor, the luminous current can be expressed as: ; The luminous current IT3 is only related to the reference voltage V REF2 D-point potential VD and transistor process parameters ( Related to the threshold voltage V of the third switch T3. TH3 This is unrelated to the threshold voltage drift of the third switch T3, and it achieves compensation for the fluctuation of the emission current caused by the change of the threshold voltage.

[0036] (3) The amplitude of the light-emitting current is determined by the DATA_PAM data voltage during the PAM data writing stage. The gate-source voltage difference of T3 is changed by the signal DATA_PAM to achieve linear adjustment of the size of IT3 and control the current size.

[0037] The negative feedback principle of drive transistor mobility compensation: During the light-emitting stage, the series feedback structure of the second capacitor C2 and the third capacitor C3 is used to compensate for the mobility drift of the driving transistor. The core is to counteract the influence of mobility change on the light-emitting current by forming a negative feedback mechanism. When considering the feedback effect of the third capacitor C3, the second capacitor C2 and the third capacitor C3 are in series at this stage. Part of the voltage of Vcsr6 is coupled to point C of the gate of the third switch T3 through the third capacitor C3. At this time, the real-time potential of point C is: ; Substituting the updated VC into the luminous current formula, the current formula involving mobility can be derived as follows: ; Based on the above expression, it can be concluded that if... As the mobility increases, the luminous current IT3 increases accordingly, while the voltage at point C of the gate of the third switching transistor T3 gradually decreases during the luminescence process through discharge, directly causing the luminous current to decrease in the reverse direction; conversely, when the mobility decreases... When the current decreases, the initial emission current drops, the discharge rate of the voltage at point C slows down, and the potential is relatively higher, maintaining the stability of the emission current and forming dynamic negative feedback. This achieves adaptive compensation for the mobility drift of the driving transistor, effectively suppressing mobility changes caused by process deviations and device aging, and ensuring the accuracy and stability of the emission current throughout the entire emission cycle.

[0038] The DATA_PWM and DATA_PAM voltages can be dynamically adjusted simultaneously, enabling precise control of both current amplitude and emission time, and achieving finer grayscale adjustment within a limited frame time.

[0039] like Figure 2 and Figure 3 As shown, this embodiment of the invention also provides a novel AMOLED pixel driving method, applied to a novel AMOLED pixel driving circuit, the method comprising: Step 1: The control module acquires the first control signal and controls the second switch T2, which is multiplexed by the control module and the threshold voltage extraction module, to turn on so that the new AMOLED pixel driving circuit enters the reset stage. Step 2: The control module acquires the second control signal and controls the second switch T2, which is multiplexed by the control module and the threshold voltage extraction module, to turn off, so that the new AMOLED pixel driving circuit can enter the PWM data writing stage. Step 3: The control module acquires the third control signal. The third control signal is transmitted to the light-emitting element through the seventh switch T7, which is multiplexed by the driving module and the threshold voltage extraction module. The conduction current of the light-emitting element is controlled by the third control signal so that the new AMOLED pixel driving circuit enters the pre-charging stage. Step 4: The driving module obtains the fourth control signal. The fourth control signal controls the seventh switch T7, which is multiplexed by the driving module and the threshold voltage extraction module, to turn on until the voltage between the second switch T2 and the seventh switch T7 is equal to the threshold voltage of the seventh switch T7, so that the new AMOLED pixel driving circuit enters the threshold voltage extraction stage. Step 5: The driving module acquires the fifth control signal. The fifth control signal controls the seventh switch T7, which is multiplexed by the driving module and the threshold voltage extraction module, to turn on, so that the new AMOLED pixel driving circuit enters the light-emitting stage. The voltage signal connected to the control module drives and controls the conduction current and conduction time of the light-emitting element.

[0040] Specifically, when the new AMOLED pixel driving circuit enters the reset phase, the gate of the first switch transistor T1 receives a high-level first control signal SCAN(N) from the AMOLED controller, while the other signals are low-level. The first switch transistor T1 is turned on, and the gate voltage of the second switch transistor T2 is charged to the first reference voltage source V through the first capacitor C1. ref1 (V) ref1 >V TH2 ).

[0041] Specifically, when the new AMOLED pixel driving circuit enters the PWM data writing stage, the gate of the third switch T3 and the gate of the fifth switch T5 are at a high level from the second control signal SCAN(N+1) obtained from the AMOLED controller, while the other signals are at a low level. The second switch T2, the third switch T3 and the fifth switch T5 are all turned on. The source voltage of the second switch T2 is pulled down to the voltage signal DATA_PWM, while the gate voltage of the second switch T2 is the reference voltage. At this time, the source voltage of the second switch T2 is pulled low, causing the second switch T2 to turn on, and the first capacitor C1 discharges through the second switch T2.

[0042] Specifically, when the new AMOLED pixel driving circuit enters the pre-charging stage, the gate of the fourth switch T4 obtains the third control signal V from the AMOLED controller. C1 When the signal is high, all other signals are low. The fourth switch T4 is turned on, and the voltage signal DATA_PAM charges the C node between the second switch T2 and the seventh switch T7 through the fourth switch T4. When stable, the voltage of the C node is stable at DATA_PAM. Here, the voltage of DATA_PAM is a positive voltage, which can drive the seventh switch T7 to work in the voltage saturation region to control the current through the light-emitting element, that is, the conduction current of the light-emitting element.

[0043] Specifically, when the new AMOLED pixel driving circuit enters the threshold voltage extraction stage, the gates of the sixth switch T6 and the eighth switch T8 obtain the fourth control signal V from the AMOLED controller. C2 The signal is at a high level, while all other signals are at a low level. Switches T6 and T8 are both turned on. The source voltage of switch T7 is low, while its gate voltage is DATA_PAM. This turns on switch T7, and the C-node between switch T2 and switch T7 discharges through capacitor C2. When the voltage at node C equals the threshold voltage of switch T7, switch T7 closes and stops discharging. At this point, the gate voltage VC of switch T7 is V. TH3 +V ref2 .

[0044] Specifically, when the new AMOLED pixel driving circuit enters the light-emitting stage, the second switch T2, the seventh switch T7, the ninth switch T9, the tenth switch T10, the eleventh switch T11, and the twelfth switch T12 in the driving module are all turned on, the light-emitting element begins to emit light, and the slope signal Sweep begins to rise linearly from a low level. Through the coupling effect of the first capacitor C1, the potential at node B between the first switch T1 and the second switch T2 also gradually rises, i.e., VB = V. DATA_PWM +VTH2 +V Sweep The voltage at node B reaches the threshold voltage of the second switch T2, causing the second switch T2 to turn on. At the same time, the ninth switch T9 turns on, and the voltage at node C discharges through the second switch T2 and the ninth switch T9, causing the seventh switch T7 to close and the light-emitting element to stop emitting light.

[0045] Specifically, the luminous current of the light-emitting element can be expressed as: ; As can be seen from the above formula, the luminous current is independent of the threshold voltage of the seventh switch T7, and ; As can be seen from the above formula, the decrease in the light emission of the light-emitting element is not affected by the threshold voltage of the second switching transistor T2, but is only controlled by the voltage signal DATA_PWM.

[0046] In this embodiment of the invention, considering the feedback effect of the third capacitor C3, the first capacitor C1 and the second capacitor C2 are both in series. Part of the voltage is applied to node C through the third capacitor C3. At this time, the voltage at node C is: ; Substituting the voltage at node C into the expression for calculating the luminous current, we get: ; As can be seen from the above formula, if As the current increases, the luminous current also increases, but the gate voltage V of the eleventh switch T11... C3 During the emission process, the discharge gradually decreases, thus reducing the emission current and forming negative feedback. This suppresses the influence of increased mobility on the emission current, and vice versa, thereby compensating for the mobility shift of the switching transistor.

[0047] In this embodiment of the invention, when the voltage signal DATA_PWM remains constant while the voltage signal DATA_PAM is changed, the novel AMOLED pixel driving circuit operates in PWM driving mode. Based on the principle of PWM driving, the light-emitting element is driven, and the waveform of the luminous current is obtained as shown below. Figure 4 As shown, by Figure 4 It can be seen that the rise and fall times of the light-emitting current waveform are not affected by the DATA_PWM data. This invention enables the light-emitting element to operate under a constant current, and the pulse width of the current waveform can be adjusted by adjusting the value of DATA_PWM. It also has excellent PWM pulse modulation performance.

[0048] In this embodiment of the invention, when the voltage signal DATA_PAM remains constant while the voltage signal DATA_PWM is changed, the novel AMOLED pixel driving circuit operates in PAM driving mode. The brightness of the light-emitting element is adjusted by changing the current magnitude while keeping the pulse width of the current pulse constant. Based on the principle of PWM driving and combined with the light-emitting characteristics of the light-emitting element, the light-emitting element is driven, and the waveform of the emitting current is obtained as shown in the figure. Figure 5 As shown, by Figure 5 As can be seen, in order to avoid the problem of a sharp drop in the luminous efficiency of the light-emitting element under low current density, a higher voltage signal DATA_PAM can be selected to modulate the grayscale displayed by the light-emitting element.

[0049] This invention includes a light-emitting element, a control module for controlling the conduction time and conduction current of the light-emitting element by receiving a voltage signal, a threshold voltage extraction module for extracting the threshold voltage of a switching transistor, and a driving module for driving the light-emitting element to operate based on the threshold voltage of the switching transistor. The control module, threshold voltage extraction module, and driving module share a second switching transistor. The control module and driving module also share a first capacitor. The driving module and threshold voltage extraction module share a seventh switching transistor. Compared with the prior art, this invention controls the conduction time and conduction current of the light-emitting element by receiving a voltage signal from the control module and using the shared switching transistor. This allows for finer grayscale control within a limited frame time, significantly improving grayscale levels and display detail. The threshold voltage extraction module eliminates the influence of threshold voltage changes on the light-emitting current, effectively suppressing current changes caused by process deviations or aging, ensuring the accuracy and stability of the light-emitting current, and improving display uniformity and reliability.

[0050] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A novel AMOLED pixel driving circuit, characterized in that, include: Light-emitting elements; The control module is used to control the conduction time and conduction current of the light-emitting element by receiving a voltage signal; Threshold voltage extraction module, used to extract the threshold voltage of the switching transistor; A driving module is used to drive the light-emitting element to work according to the threshold voltage of the switching transistor; The control module, the threshold voltage extraction module, and the drive module share a second switching transistor; The control module and the drive module also share a first capacitor; The driving module and the threshold voltage extraction module share a seventh switching transistor; The first end of the light-emitting element is electrically connected to the power supply end; The second end of the light-emitting element is electrically connected to the output end of the driving module; The first control terminal and the second control terminal of the driving module are both electrically connected to the output terminal of the AMOLED controller; The input terminal of the driving module is connected to the output terminal of the threshold voltage extraction module; The first input terminal of the control module is electrically connected to the output terminal of the AMOLED controller, and the second input terminal of the control module is used to receive the input voltage; The output of the control module is electrically connected to the input of the threshold voltage extraction module and the input of the drive module via a multiplexed switching transistor.

2. The novel AMOLED pixel driving circuit according to claim 1, characterized in that, The control module includes: First reference voltage source; A current control unit is used to control the conduction current of the light-emitting element; A PWM generation unit is used to generate a PWM pulse signal that controls the conduction time of the light-emitting element; The first input terminal of the current control unit is used to receive the input voltage; The second input terminal of the current control unit and the first input terminal of the PWM generation unit are both electrically connected to the output terminal of the AMOLED controller. The second input terminal of the PWM generation unit is electrically connected to the output terminal of the current control unit; The first output terminal of the PWM generation unit is electrically connected to the input terminal of the threshold voltage extraction module and the input terminal of the drive module through a multiplexed switching transistor. The second output terminal of the PWM generation unit is connected to the input terminal of the first reference voltage source.

3. The novel AMOLED pixel driving circuit according to claim 2, characterized in that, The PWM generation unit includes: First switching transistor, second switching transistor, third switching transistor, fifth switching transistor, first capacitor; The gates of the first switch, the third switch, and the fifth switch are all electrically connected to the output terminal of the AMOLED controller. The source of the first switching transistor is electrically connected to the first reference voltage source; The drain of the first switching transistor is electrically connected to the drain of the third switching transistor, the gate of the second switching transistor, and the first capacitor, respectively. The source of the second switching transistor is electrically connected to the input terminal of the driving module and the drain of the fifth switching transistor, respectively. The drain of the second switching transistor is electrically connected to the source of the third switching transistor, the source of the current control unit, and the input terminal of the threshold voltage extraction module, respectively. The source of the fifth switch is used to receive a voltage signal.

4. The novel AMOLED pixel driving circuit according to claim 2, characterized in that, The threshold voltage extraction module includes: Second reference voltage source, second switch, sixth switch, seventh switch, eighth switch; The drain of the second switch is electrically connected to the drain of the sixth switch, the gate of the seventh switch, and the input terminal of the drive module, respectively. The source of the second switching transistor is electrically connected to the input terminal of the drive module; The gates of the sixth and eighth switching transistors are both electrically connected to the output terminal of the AMOLED controller. The source of the sixth switch is electrically connected to the input terminal of the drive module and the drain of the seventh switch, respectively. The drain of the eighth switch is electrically connected to the input terminal of the drive module and the source of the seventh switch, and the source of the eighth switch is electrically connected to the second reference voltage source.

5. The novel AMOLED pixel driving circuit according to claim 4, characterized in that, The driving module includes: Second switch, seventh switch, ninth switch, tenth switch, eleventh switch, twelfth switch, first capacitor, second capacitor, third capacitor; The source of the second switching transistor is electrically connected to the drain of the ninth switching transistor, and the drain of the second switching transistor is electrically connected to the first terminal of the second capacitor and the drain of the tenth switching transistor. The gates of the ninth switch, the tenth switch, the eleventh switch, and the twelfth switch are all electrically connected to the output terminal of the AMOLED controller. The source of the ninth switch is connected to the second terminal of the second capacitor and the source of the twelfth switch, respectively, and grounded. The source of the tenth switch is electrically connected to the first terminal of the third capacitor; The second terminal of the third capacitor is electrically connected to the source of the seventh switch, the drain of the twelfth switch, and the drain of the eighth switch, respectively.

6. A novel AMOLED pixel driving method, characterized in that, The method, applied to the novel AMOLED pixel driving circuit as described in any one of claims 1-5, comprises: Step 1: The control module acquires a first control signal and controls the second switch transistor, which is multiplexed by the control module and the threshold voltage extraction module, to turn on, so that the novel AMOLED pixel driving circuit enters the reset stage. Step 2: The control module acquires a second control signal and controls the second switch transistor multiplexed by the control module and the threshold voltage extraction module to turn off, so that the new AMOLED pixel driving circuit enters the PWM data writing stage. Step 3: The control module acquires a third control signal, which is transmitted to the light-emitting element via a seventh switch multiplexed by the driving module and the threshold voltage extraction module. The third control signal controls the conduction current of the light-emitting element so that the novel AMOLED pixel driving circuit enters the pre-charging stage. Step 4: The driving module acquires a fourth control signal, which controls the seventh switch transistor multiplexed by the driving module and the threshold voltage extraction module to turn on until the voltage between the second switch transistor and the seventh switch transistor is equal to the threshold voltage of the seventh switch transistor, thereby enabling the novel AMOLED pixel driving circuit to enter the threshold voltage extraction stage. Step 5: The driving module acquires a fifth control signal, which controls the seventh switch multiplexed by the driving module and the threshold voltage extraction module to turn on, so that the novel AMOLED pixel driving circuit enters the light-emitting stage. The voltage signal received by the control module drives and controls the conduction current and conduction time of the light-emitting element.

7. The novel AMOLED pixel driving method according to claim 6, characterized in that, When the novel AMOLED pixel driving circuit enters the light-emitting stage, the second, seventh, ninth, tenth, eleventh, and twelfth switching transistors in the driving module are all turned on, and the light-emitting element begins to emit light.

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