Micro-LET display pixel driving circuit

Abstract

The application discloses a Micro-LET display pixel driving circuit, and relates to the field of photoelectric display, comprising: a Micro-LET device, a switch compensation circuit; the anode of the Micro-LET device is connected with a high potential of a power supply, and the cathode of the Micro-LET is connected with a low potential of the power supply; the switch compensation circuit comprises: a driving control transistor, a pull-down control transistor, a power supply control transistor, a voltage compensation transistor, a second capacitor, a data signal input control transistor and a first capacitor; the switch compensation circuit is used for compensating the unstable driving current caused by the threshold voltage and the mobility of a thin film transistor; according to the optimization of the traditional Micro-LED pixel driving circuit, the threshold voltage of the driving control transistor is compensated, so that the current flowing through the light-emitting diode is independent of the threshold voltage of the driving control transistor, and through the control of the time sequence, the compensation of the influence of the transistor mobility change can be realized.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic displays, and in particular to a Micro-LET display pixel driving circuit. Background Technology

[0002] Micro-LET utilizes a vertical integration method of "LED on BJT," where the BJT collector region is shared with the n-type semiconductor region of the LED. Micro-LET includes three electrodes: gate (base), cathode (emitter), and anode. By constructing a heterojunction to form a two-dimensional electron gas, the majority carrier concentration in the emitter region is greater than that in the base region. Utilizing the current amplification effect of a transistor, a small current in the transistor's base region generates a larger current signal at the collector, which is then injected into the LED's light-emitting region. This reduces the traditional LED driving voltage, improves luminous efficiency, and enables high light emission from a low-current controlled device, allowing for LED light emission control with a small power signal.

[0003] Traditional Micro-LED display driving technologies can be divided into passive driving and active driving. Active driving can be further divided into metal-oxide-semiconductor (MOSFET) active driving, thin-film transistor (TFT) driving, and monolithic integrated driving. CMOS driving circuits and processes are relatively simple, but they are not conducive to large-area fabrication. Monolithic integrated secondary epitaxy processes are difficult and expensive, making industrial implementation challenging. Therefore, TFT (thin-film transistor) driving is chosen, which can fabricate display panels with large areas, high driving capabilities, and fast response speeds. To achieve high brightness in Micro-LED display panels using TFT driving, higher data voltages and high-mobility TFT materials (such as polycrystalline silicon p-Si and indium tin oxide ITO) are required, or the TFT channel needs to be enlarged. However, this prevents the pixel size from being very small and places higher demands on the TFT type and process. Therefore, a new type of display device with current gain, Micro-LED, has been proposed, and the pixel circuit driving this device is essential. Traditional Micro-LED pixel driving circuits cannot be directly used to drive Micro-LEDs because during the reset and compensation phases, the potential difference between the anode and cathode of a traditional Micro-LED does not reach the LED's turn-on voltage, thus preventing it from emitting light, although a certain voltage drop exists. However, Micro-LEDs control LED emission by controlling the base signal of a BJT. The BJT's turn-on voltage is lower than that of a typical Micro-LED. This voltage drop allows the Micro-LED to achieve the conduction requirement during the non-emitting phase of a traditional pixel circuit, resulting in flickering and emission. Therefore, the research on this pixel circuit has significant scientific importance and application prospects.

[0004] Furthermore, for thin-film transistors, the threshold voltage of the driving control transistor may drift due to device aging and other reasons, affecting display uniformity. Summary of the Invention

[0005] In view of some shortcomings of the prior art, the technical problem to be solved by the present invention is to provide a Micro-LED display pixel driving circuit, which aims to enable Micro-LEDs with current gain effects to better exert their high brightness performance. Based on the optimization of the traditional Micro-LED pixel driving circuit, the threshold voltage of the driving control transistor is compensated, so that the current flowing through the light-emitting transistor is independent of the threshold voltage of the driving control transistor. Furthermore, by controlling the timing, the influence of transistor mobility variations can be compensated, effectively reducing the uneven display brightness phenomenon on the display panel.

[0006] To achieve the above objectives, the present invention provides a Micro-LET display pixel driving circuit, the driving circuit comprising: a Micro-LET device and a switching compensation circuit; the Micro-LET device is a light-emitting transistor, comprising a bipolar junction transistor and a light-emitting diode, and under base regulation, the number of electrons moving to the light-emitting active region is controlled by changing the base voltage, thereby regulating the light-emitting effect of the device; the switching compensation circuit is used to compensate for the unstable driving current caused by the threshold voltage and mobility of the thin-film transistor; the anode of the Micro-LET device is connected to a high potential power supply, and the cathode of the Micro-LET is connected to a low potential power supply.

[0007] The switching compensation circuit includes:

[0008] A drive control transistor; the drain of the drive control transistor is electrically connected to the base of the Micro-LET device;

[0009] A pull-down control transistor; the source of the pull-down control transistor is electrically connected to the drain of the drive control transistor, the drain of the pull-down control transistor is connected to a low potential power supply, and the gate of the pull-down control transistor is electrically connected to a pull-down control terminal; the pull-down control transistor is used to pull down the potential of the drain of the drive control transistor.

[0010] A power supply control transistor; the power supply control transistor is electrically connected between the high potential of the power supply and the source of the drive control transistor through its source and drain, and the gate of the power supply control transistor is electrically connected to the third control terminal;

[0011] A voltage compensation transistor; the voltage compensation transistor is electrically connected between the source and gate of the drive control transistor through its source and drain, and the gate of the voltage compensation transistor is electrically connected to the second control terminal; the voltage compensation transistor is used to compensate for the unstable drive current caused by the threshold voltage and mobility of the thin film transistor.

[0012] The second capacitor is loaded between the gate of the driving control transistor and the low potential of the power supply, and is used to charge and store energy and provide gate voltage for the driving control transistor when the pixel is lit.

[0013] A data signal input control transistor is used to control the input of data signals; the source of the data signal input control transistor is electrically connected to the data terminal, and the drain of the data signal input control transistor is electrically connected to the gate of the drive control transistor through a first capacitor, forming a charging and energy storage circuit with a second capacitor; the gate of the data signal input control transistor is electrically connected to the first control terminal.

[0014] Specifically, when the gate of the voltage compensation transistor is turned on, it is the threshold voltage of the compensation transistor of the drive control transistor; when the data terminal is charging and storing energy in the second capacitor, the gate of the voltage compensation transistor is triggered by the turning signal to trigger a falling edge, thereby triggering a voltage boost at the gate of the drive control transistor; the voltage boost is used to compensate for the transistor mobility.

[0015] In one specific embodiment, each transistor is a thin-film transistor, including A-Si (amorphous silicon), LTPS (low-temperature polycrystalline silicon), IGZO (indium germanium zinc oxide), and LTPO (low-temperature polycrystalline oxide).

[0016] In one specific embodiment, the active layer electron mobility of the transistor ranges from 0.1 to 200 cm⁻¹. 2 / (V·S).

[0017] In one specific embodiment, the pull-down control terminal is electrically connected to the first control terminal.

[0018] In one embodiment, each transistor is an enhancement-mode transistor and / or a depletion-mode transistor, and a corresponding control signal is input to its gate according to the required turn-on or turn-off requirements.

[0019] To address the issue of a voltage drop between the source and drain of the pull-down control transistor when it is turned on, which causes flickering due to a voltage difference between the base and cathode of the Micro-LET device, in one specific embodiment, a base control transistor is electrically connected between the drain of the drive control transistor and the base of the Micro-LET device. The drain of the drive control transistor is connected to the source of the base control transistor, the drain of the base control transistor is electrically connected to the base of the Micro-LET device, and the gate of the drive control transistor is electrically connected to the enable control terminal.

[0020] A second aspect of the present invention also provides a Micro-LET display pixel driving circuit control method, applied to the driving circuit provided in any one of claims 1-5, the method comprising:

[0021] Step S1: Control the pull-down control transistor to turn on, so that the Micro-LET device does not emit light; control the voltage compensation transistor, the power supply control transistor, and the data signal input control transistor to turn on, so that the drive control transistor enters the reset state and charges the first capacitor or the second capacitor to store energy.

[0022] Step S2: Keep the pull-down control transistor on, so that the Micro-LET device does not emit light; keep the voltage compensation transistor and the data signal input control transistor on, and control the power supply control transistor to be in the off state; wherein, the voltage compensation transistor is on, and the drive control transistor is controlled to be on due to the first capacitor or the second capacitor that has been charged and stored in step S1, so that the voltage difference between the gate voltage and the source of the drive control transistor is the threshold voltage, and the drive control transistor is turned off as the potential of the second capacitor is consumed;

[0023] Step S3: Keep the pull-down control transistor on, so that the Micro-LET device does not emit light; keep the data signal input control transistor on, control the data terminal to input a data control signal corresponding to the pixel gray value, control the power supply control transistor to be in the off state, and give the gate of the voltage compensation transistor a falling edge at time t, so that the gate of the drive control transistor is subjected to the falling edge abrupt change to generate a first voltage increment to compensate for the transistor mobility;

[0024] Step S4: Control the power supply control transistor to turn on, and control the voltage compensation transistor, the data signal input control transistor, and the pull-down control transistor to turn off, so that the drive control transistor is turned on by the potential control of the second capacitor, and drives the Micro-LET device to store energy in the second capacitor and light it up by controlling the data signal input in step S3.

[0025] In one specific embodiment, a base control transistor is electrically connected between the drain of the driving control transistor and the base of the Micro-LET device, wherein the drain of the driving control transistor is connected to the source of the base control transistor, the drain of the base control transistor is electrically connected to the base of the Micro-LET device, and the gate of the driving control transistor is electrically connected to the enable control terminal; the method further includes: in steps S1-S3, keeping the base control transistor off.

[0026] A third aspect of the invention also provides a Micro-LET display pixel panel, the panel comprising a Micro-LET display pixel driving circuit as provided in any one of claims 1-6.

[0027] In one specific embodiment, a base control transistor is electrically connected between the drain of the driving control transistor and the base of the Micro-LET device, wherein the drain of the driving control transistor is connected to the source of the base control transistor, the drain of the base control transistor is electrically connected to the base of the Micro-LET device, and the gate of the driving control transistor is electrically connected to the enable control terminal.

[0028] The beneficial effects of this invention are as follows: Based on the optimization of traditional Micro-LED pixel driving circuits, this invention compensates for the threshold voltage of the driving control transistor, making the current flowing through the light-emitting transistor independent of the threshold voltage of the driving control transistor. Furthermore, through timing control, it compensates for the influence of transistor mobility variations. The technical solution provided by this invention enables Micro-LEDs with current gain effects to better achieve high brightness performance. In addition, the technical solution provided by this invention, by setting a base control transistor, can prevent flickering on the display panel and prevent uneven display brightness. It can also reduce the number of components and signal lines in the pixel circuit, improving the aperture ratio and pixel density. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a Micro-LET display pixel driving circuit according to a specific embodiment of the present invention;

[0030] Figure 2This is a timing diagram of a Micro-LET display pixel driving circuit according to a specific embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of a Micro-LET display pixel panel according to a specific embodiment of the present invention. Detailed Implementation

[0032] The embodiments of this patent are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and should not be construed as limiting this patent.

[0033] In the description of this patent, it should be understood that the terms “center,” “upper,” “lower,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this patent.

[0034] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0035] This invention provides a Micro-LET display pixel driving circuit, such as... Figures 1-2 As shown, it includes: a Micro-LET device and a switching compensation circuit; the Micro-LET device is a light-emitting transistor, comprising a bipolar junction transistor and a light-emitting diode, and under base regulation, the number of electrons moving to the light-emitting active region is controlled by changing the base voltage, thereby regulating the light-emitting effect of the device; the switching compensation circuit is used to compensate for the unstable driving current caused by the threshold voltage and mobility of the thin-film transistor; the anode of the Micro-LET device is connected to a high potential power supply, and the cathode of the Micro-LET is connected to a low potential power supply.

[0036] The switching compensation circuit includes:

[0037] A drive control transistor; the drain of the drive control transistor is electrically connected to the base of the Micro-LET device;

[0038] A pull-down control transistor; the source of the pull-down control transistor is electrically connected to the drain of the drive control transistor, the drain of the pull-down control transistor is connected to a low potential power supply, and the gate of the pull-down control transistor is electrically connected to a pull-down control terminal; the pull-down control transistor is used to pull down the potential of the drain of the drive control transistor.

[0039] A power supply control transistor; the power supply control transistor is electrically connected between the high potential of the power supply and the source of the drive control transistor through its source and drain, and the gate of the power supply control transistor is electrically connected to the third control terminal;

[0040] A voltage compensation transistor; the voltage compensation transistor is electrically connected between the source and gate of the drive control transistor through its source and drain, and the gate of the voltage compensation transistor is electrically connected to the second control terminal; the voltage compensation transistor is used to compensate for the unstable drive current caused by the threshold voltage and mobility of the thin film transistor.

[0041] The second capacitor is loaded between the gate of the driving control transistor and the low potential of the power supply, and is used to charge and store energy and provide gate voltage for the driving control transistor when the pixel is lit.

[0042] A data signal input control transistor is used to control the input of data signals; the source of the data signal input control transistor is electrically connected to the data terminal, and the drain of the data signal input control transistor is electrically connected to the gate of the drive control transistor through a first capacitor, forming a charging and energy storage circuit with a second capacitor; the gate of the data signal input control transistor is electrically connected to the first control terminal.

[0043] Specifically, when the gate of the voltage compensation transistor is turned on, it is the threshold voltage of the compensation transistor of the drive control transistor; when the data terminal is charging and storing energy in the second capacitor, the gate of the voltage compensation transistor is triggered by the turning signal to trigger a falling edge, thereby triggering a voltage boost at the gate of the drive control transistor; the voltage boost is used to compensate for the transistor mobility.

[0044] Optionally, each transistor is a thin-film transistor, including A-Si (amorphous silicon), LTPS (low-temperature polycrystalline silicon), IGZO (indium germanium zinc oxide), and LTPO (low-temperature polycrystalline oxide).

[0045] Optionally, the active layer electron mobility of the transistor ranges from 0.1 to 200 cm⁻¹. 2 / (V·S).

[0046] Optionally, the pull-down control terminal is electrically connected to the first control terminal to merge the two control terminals.

[0047] It is worth mentioning that the transistor in this embodiment can be either an enhancement-mode transistor or a depletion-mode transistor, and a corresponding control signal is input to the gate according to the required turn-on or turn-off requirements. The control level corresponding to the corresponding drive timing diagram needs to be adjusted accordingly. Figure 2 The corresponding timing diagram is adapted to the enhancement transistor.

[0048] Furthermore, to address the issue of a voltage drop between the source and drain when the pull-down control transistor is turned on, which causes flickering due to a certain voltage between the base and cathode of the Micro-LET device, in this embodiment, a base control transistor is electrically connected between the drain of the drive control transistor and the base of the Micro-LET device. The drain of the drive control transistor is connected to the source of the base control transistor, the drain of the base control transistor is electrically connected to the base of the Micro-LET device, and the gate of the drive control transistor is electrically connected to the enable control terminal.

[0049] In practical applications, the driving circuit on the panel is an M×N pixel array, where M and N can be natural numbers greater than or equal to 2. At this time, the energy storage voltage of the second capacitor can be recorded by scanning line by line. For a frame, M pulses (corresponding to M lines) can be used to record the grayscale value of the entire display pixel.

[0050] Furthermore, during display scanning operations, the high-level control signal range for each transistor gate can be 3-20 volts. It is worth noting that increasing the drive current and switching ratio can be achieved by enlarging the channel of the drive control transistor.

[0051] The driving circuit provided in this embodiment controls transistors via scanning signals. Compared to the traditional 7T1C pixel circuit structure, it reduces the number of thin-film transistors, increases the aperture ratio, facilitates layout and wiring, increases pixel density, and provides better charge retention capability, which helps improve image stability, reduce ghosting, and enhance contrast and color accuracy. It also makes the current of the Micro-LED independent of the threshold voltage of the driving control transistor, thus effectively solving the problem of uneven panel display caused by thin-film transistor threshold voltage drift. Furthermore, compared to the pixel circuit of Micro-LED, it can obtain a larger driving current under the same voltage conditions, enabling the light-emitting device to achieve higher brightness.

[0052] In a second embodiment of the present invention, a method for controlling a Micro-LET display pixel driving circuit is provided, characterized in that it is applied to the driving circuit provided by any one of claims 1-5, and the method includes:

[0053] Step S1: Control the pull-down control transistor to turn on, so that the Micro-LET device does not emit light; control the voltage compensation transistor, the power supply control transistor, and the data signal input control transistor to turn on, so that the drive control transistor enters the reset state and charges the first capacitor or the second capacitor to store energy.

[0054] Step S2: Keep the pull-down control transistor on, so that the Micro-LET device does not emit light; keep the voltage compensation transistor and the data signal input control transistor on, and control the power supply control transistor to be in the off state; wherein, the voltage compensation transistor is on, and the drive control transistor is controlled to be on due to the first capacitor or the second capacitor that has been charged and stored in step S1, so that the voltage difference between the gate voltage and the source of the drive control transistor is the threshold voltage, and the drive control transistor is turned off as the potential of the second capacitor is consumed;

[0055] Step S3: Keep the pull-down control transistor on, so that the Micro-LET device does not emit light; keep the data signal input control transistor on, control the data terminal to input a data control signal corresponding to the pixel gray value, control the power supply control transistor to be in the off state, and give the gate of the voltage compensation transistor a falling edge at time t, so that the gate of the drive control transistor is subjected to the falling edge abrupt change to generate a first voltage increment to compensate for the transistor mobility;

[0056] Step S4: Control the power supply control transistor to turn on, and control the voltage compensation transistor, the data signal input control transistor, and the pull-down control transistor to turn off, so that the drive control transistor is turned on by the potential control of the second capacitor, and drives the Micro-LET device to store energy in the second capacitor and light it up by controlling the data signal input in step S3.

[0057] Furthermore, a base control transistor is electrically connected between the drain of the driving control transistor and the base of the Micro-LET device, wherein the drain of the driving control transistor is connected to the source of the base control transistor, the drain of the base control transistor is electrically connected to the base of the Micro-LET device, and the gate of the driving control transistor is electrically connected to the enable control terminal; the method further includes: in steps S1-S3, keeping the base control transistor off.

[0058] like Figure 2 As shown, Figure 2 This is a timing diagram illustrating the operation of the driving circuit provided in this embodiment of the invention. This timing diagram is applicable to... Figure 1The pixel circuit shown includes the following operation process: initialization stage t1, write compensation first stage t2, write compensation second stage t3, and light emission stage t4. The first three stages t1, t2, and t3 are the working stages of the switching compensation circuit.

[0059] The pixel circuit and its working process provided in this embodiment are introduced using the data signal input control transistor T1, voltage compensation transistor T2, power supply control transistor T3, base control transistor T4, pull-down control transistor T5, and drive control transistor Td as examples.

[0060] During the initialization phase t1, refer to Figure 1 and Figure 2 When the first and third scan signals are input at a high level, the data signal input control transistor T1, voltage compensation transistor T2, power supply control transistor T3, and pull-down control transistor T5 are turned on, while the base control transistor T4 is turned off. Due to the capacitor coupling, the drive control transistor Td enters the reset state. The first control signal is then input to the data signal input terminal, turning off the drive control transistor Td, and the Micro-LED does not emit light. Typically, the first control signal is at a 0 level.

[0061] In the first compensation stage t2, control signals are input to the corresponding scan signal input terminals, causing the data signal input control transistor T1, voltage compensation transistor T2, and pull-down control transistor T5 to turn on, while the power supply control transistor T3 and base control transistor T4 are turned off. The data signal input terminals still receive the first control signal, but as voltage compensation transistor T2 turns on, the drive control transistor Td enters diode mode. The charge stored in the capacitor during stage t1 begins to release, and voltage is written to the control terminal of drive control transistor Td, turning it on. This causes the control terminal voltage of drive control transistor Td to be higher than its source voltage by a threshold voltage value. Then, drive control transistor Td turns off, and at this point, the gate voltage V... G =V th +V S This completes the compensation of the threshold voltage.

[0062] In the second compensation stage t3, control signals are input to each scan signal input terminal, and a second control signal is input to the data signal input terminal, causing the data signal input control transistor T1 and the pull-down control transistor T5 to turn on, while the power supply control transistor T3 and the base control transistor T4 are turned off. The voltage compensation transistor T2 turns on and then turns off at time t. Through this short-term sudden change in voltage, the voltage increment, after conduction and capacitive coupling, will generate a voltage increment at point N2, thus completing the compensation for the impact of the mobility change on the driving current of the light-emitting element in the next stage.

[0063] During the light-emitting stage, control signals are input corresponding to each scanning signal input terminal, and the enable terminal is enabled, causing the power supply control transistor T3 and the base control transistor T4 to conduct, and the data signal input control transistor T1, the voltage compensation transistor T2, and the pull-down control transistor T5 to cut off. A first control signal is input to the data signal input terminal, causing the drive control transistor Td to conduct, generating a drive current. The drive current where μ FE is the field-effect mobility of the MOS device, C i is the capacitance of the gate insulation layer per unit area, W is the channel width of the MOS transistor, L is the channel length of the MOS transistor, V TH is the threshold voltage of the MOS transistor, and Δu is a small voltage increment that is positively correlated with the mobility change generated by compensation. The compensation effect can be clearly seen through the formula. Finally, it flows through the base control transistor T4 to the organic light-emitting triode, and Micro-LET emits light.

[0064] At this point, the scanning display of one frame of the picture is completed. Until the next scanning signal arrives at a low level, the scanning display of the second frame of the picture starts.

[0065] Here, a supplementary explanation of the voltage increment is given.

[0066] Assume that V4 is the gate voltage of T d During the first stage t2 of the write compensation, the following compensation is completed:

[0067] V GS =V c2 =V4 - V s =V TH

[0068] During the second stage t3 of the write compensation, after the gray-scale value signal is input to V DATA it satisfies: Satisfy:

[0069]

[0070] When t0 < t ≤ t1, the potential of V4 drops by Δu;

[0071]

[0072] At this moment, V DATA , C1, C2, TD are in a closed loop.

[0073] Therefore:

[0074]

[0075] Integration gives:

[0076]

[0077] Find the general solution:

[0078] C1 is a constant

[0079] When t = t0,

[0080] Compare with the previous (2)

[0081]

[0082] Substitute into (6)

[0083] Substitute

[0084] Substitute t1 = t0 + T into (8)

[0085]

[0086] When t1 < t ≤ t2, the voltage at both ends of C2 is in a steady state. Among them, when K↓, then Δu↓; when K↑, then Δu↑.

[0087] In the light-emitting stage:

[0088] V4 = V4(t = t1)

[0089] Substitute

[0090] Among them, β is the amplification factor of BTJ, and K is related to the mobility. Finally, mobility compensation is completed.

[0091] The working timing of the pixel circuit provided in this embodiment enables the driving current of Micro-LET to be independent of the threshold voltage of the driving control transistor, thus effectively solving the problem of display unevenness caused by the threshold voltage drift of thin-film transistors. In addition, a voltage difference that is positively correlated with the mobility is generated, which can achieve the purpose of compensating for the influence of current changes caused by the mobility of thin-film transistors. In addition, due to the particularity of Micro-LET, compared with the traditional 7T1C pixel circuit of Micro-LED, this pixel circuit reduces the number of signal lines and thin-film transistors, reduces the area of the pixel circuit, is conducive to wiring, and improves the pixel density.

[0092] Such as Figure 3As shown, in the third embodiment of the present invention, a Micro-LET display pixel panel is provided, characterized in that the panel includes the Micro-LET display pixel driving circuit provided in the first embodiment; wherein, a base control transistor is electrically connected between the drain of the driving control transistor and the base of the Micro-LET device, wherein the drain of the driving control transistor is connected to the source of the base control transistor, the drain of the base control transistor is electrically connected to the base of the Micro-LET device, and the gate of the driving control transistor is electrically connected to the enable control terminal.

[0093] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A Micro-LET display pixel driving circuit, characterized in that, The driving circuit includes a Micro-LET device and a switching compensation circuit. The Micro-LET device is a light-emitting transistor, comprising a bipolar junction transistor and a light-emitting diode. Under base regulation, the number of electrons moving to the light-emitting active region is controlled by changing the base voltage, thereby regulating the light-emitting effect of the device. The switching compensation circuit is used to compensate for the unstable driving current caused by the threshold voltage and mobility of the thin-film transistor. The anode of the Micro-LET device is connected to a high potential power supply, and the cathode of the Micro-LET is connected to a low potential power supply. The switching compensation circuit includes: A drive control transistor; the drain of the drive control transistor is electrically connected to the base of the Micro-LET device; A pull-down control transistor; the source of the pull-down control transistor is electrically connected to the drain of the drive control transistor, the drain of the pull-down control transistor is connected to a low potential power supply, and the gate of the pull-down control transistor is electrically connected to a pull-down control terminal; the pull-down control transistor is used to pull down the potential of the drain of the drive control transistor. A power supply control transistor; the power supply control transistor is electrically connected between the high potential of the power supply and the source of the drive control transistor through its source and drain, and the gate of the power supply control transistor is electrically connected to the third control terminal; A voltage compensation transistor; the voltage compensation transistor is electrically connected between the source and gate of the drive control transistor through its source and drain, and the gate of the voltage compensation transistor is electrically connected to the second control terminal; the voltage compensation transistor is used to compensate for the unstable drive current caused by the threshold voltage and mobility of the thin film transistor. The second capacitor is loaded between the gate of the driving control transistor and the low potential of the power supply, and is used to charge and store energy and provide gate voltage for the driving control transistor when the pixel is lit. A data signal input control transistor is used to control the input of data signals; the source of the data signal input control transistor is electrically connected to the data terminal, and the drain of the data signal input control transistor is electrically connected to the gate of the drive control transistor through a first capacitor, forming a charging and energy storage circuit with a second capacitor; the gate of the data signal input control transistor is electrically connected to the first control terminal. Specifically, when the gate of the voltage compensation transistor is turned on, it is the threshold voltage of the compensation transistor of the drive control transistor; when the data terminal is charging and storing energy in the second capacitor, the gate of the voltage compensation transistor is triggered by the turning signal to trigger a falling edge, thereby triggering a voltage boost at the gate of the drive control transistor; the voltage boost is used to compensate for the transistor mobility.

2. The Micro-LET display pixel driving circuit as described in claim 1, characterized in that, Each transistor is a thin-film transistor, including A-Si (amorphous silicon), LTPS (low-temperature polycrystalline silicon), IGZO (indium germanium zinc oxide), and LTPO (low-temperature polycrystalline oxide).

3. The Micro-LET display pixel driving circuit as described in claim 1, characterized in that, The active layer electron mobility of the transistor ranges from 0.1 to 200 cm⁻¹. 2 / (V·S).

4. The Micro-LET display pixel driving circuit as described in claim 1, characterized in that, The pull-down control terminal is electrically connected to the first control terminal.

5. The Micro-LET display pixel driving circuit as described in claim 1, characterized in that, Each transistor is an enhancement-mode transistor and / or a depletion-mode transistor, and a corresponding control signal is input to its gate according to the required turn-on or turn-off requirements.

6. The Micro-LET display pixel driving circuit as described in claim 1, characterized in that, A base control transistor is electrically connected between the drain of the driving control transistor and the base of the Micro-LET device. The drain of the driving control transistor is connected to the source of the base control transistor, the drain of the base control transistor is electrically connected to the base of the Micro-LET device, and the gate of the driving control transistor is electrically connected to the enable control terminal.

7. A method for controlling a Micro-LET display pixel driving circuit, characterized in that, The method, applied to the drive circuit provided in any one of claims 1-5, comprises: Step S1: Control the pull-down control transistor to turn on, so that the Micro-LET device does not emit light; control the voltage compensation transistor, the power supply control transistor, and the data signal input control transistor to turn on, so that the drive control transistor enters the reset state and charges the first capacitor or the second capacitor to store energy. Step S2: Keep the pull-down control transistor on, so that the Micro-LET device does not emit light; keep the voltage compensation transistor and the data signal input control transistor on, and control the power supply control transistor to be in the off state; wherein, the voltage compensation transistor is on, and the drive control transistor is controlled to be on due to the first capacitor or the second capacitor that has been charged and stored in step S1, so that the voltage difference between the gate voltage and the source of the drive control transistor is the threshold voltage, and the drive control transistor is turned off as the potential of the second capacitor is consumed; Step S3: Keep the pull-down control transistor on, so that the Micro-LET device does not emit light; keep the data signal input control transistor on, control the data terminal to input a data control signal corresponding to the pixel gray value, control the power supply control transistor to be in the off state, and give the gate of the voltage compensation transistor a falling edge at time t, so that the gate of the drive control transistor is subjected to the falling edge abrupt change to generate a first voltage increment to compensate for the transistor mobility; Step S4: Control the power supply control transistor to turn on, and control the voltage compensation transistor, the data signal input control transistor, and the pull-down control transistor to turn off, so that the drive control transistor is turned on by the potential control of the second capacitor, and drives the Micro-LET device to store energy in the second capacitor and light it up by controlling the data signal input in step S3.

8. The Micro-LET display pixel driving circuit control method as described in claim 7, characterized in that, A base control transistor is electrically connected between the drain of the driving control transistor and the base of the Micro-LET device. The drain of the driving control transistor is connected to the source of the base control transistor, the drain of the base control transistor is electrically connected to the base of the Micro-LET device, and the gate of the driving control transistor is electrically connected to the enable control terminal. The method further includes: in steps S1-S3, keeping the base control transistor off.

9. A Micro-LET display pixel panel, characterized in that, The panel includes a Micro-LET display pixel driving circuit as provided in any one of claims 1-6.

10. A Micro-LET display pixel panel as described in claim 9, characterized in that, A base control transistor is electrically connected between the drain of the driving control transistor and the base of the Micro-LET device. The drain of the driving control transistor is connected to the source of the base control transistor, the drain of the base control transistor is electrically connected to the base of the Micro-LET device, and the gate of the driving control transistor is electrically connected to the enable control terminal.

Images