Gain circuit and method for automatically regulating photosensitive current, and display panel

Abstract

The present application provides a gain circuit and method for automatically adjusting a photosensitive current, and a display panel. The gain circuit comprises a sampling module, a gain control module, and a gain amplification module, wherein the sampling module is used for collecting a measured voltage corresponding to a photosensitive current; the gain control module is connected to the sampling module and is used for outputting a gain control voltage; and the gain amplification module comprises a voltage conversion unit and a gain amplification unit, the voltage conversion unit being used for receiving the photosensitive current and being used for converting the photosensitive current into a photosensitive voltage, and the gain amplification unit being connected to the voltage conversion unit and the sampling module, and being used for gaining the photosensitive voltage and then outputting the measured voltage to the sampling module. The gain amplification module is further connected to the gain control module, the gain control module outputs a gain control voltage to the gain amplification unit in response to the voltage value of the measured voltage not meeting a preset voltage range, and the gain amplification unit adjusts the gain of the photosensitive voltage on the basis of the gain control voltage.

Description

A light-sensing current automatic regulation gain circuit, method, and display panel

[0001] Cross-reference to Related Applications

[0002] The present application claims priority from Chinese Patent Application No. 2024112363353 filed on September 4, 2024, the disclosure of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the field of circuits, in particular to a light-sensing current automatic regulation gain circuit, method, and display panel. BACKGROUND

[0004] In the field of display circuits, ambient light sensing elements (ALS) will generate different light-sensing currents according to different light intensities, and feedback to the acquisition module (ADC), thereby adjusting the picture to reduce power consumption, protect the eyes, and prolong the life, etc.

[0005] However, sometimes the light-sensing current value is very small, which is not conducive to the acquisition of the ADC module, and will produce a large error, and blindly increasing the signal amplification multiple will have the risk of exceeding the safe voltage of the driving circuit.

[0006] Therefore, the prior art needs to be improved. SUMMARY

[0007] To solve the above problems, the present application provides a light-sensing current automatic regulation gain circuit, method, and display panel, which can improve the error when the light-sensing current is fed back to the acquisition module, and can avoid safety risks.

[0008] To solve the above problems, the first technical solution provided by the present application is to provide a light-sensing current automatic regulation gain circuit, comprising:

[0009] A sampling module for acquiring a detection voltage corresponding to a light-sensing current;

[0010] A gain control module connected to the sampling module for outputting a gain control voltage;

[0011] A gain amplification module including a voltage conversion unit and a gain amplification unit, the voltage conversion unit is configured to receive the light-sensing current and convert the light-sensing current into a light-sensing voltage; the gain amplification unit is connected to the voltage conversion unit and the sampling module, and is configured to output the detection voltage to the sampling module after gain amplification of the light-sensing voltage;

[0012] The gain amplification module is further connected with the gain control module, the gain control module outputs a gain control voltage to the gain amplification unit in response to the voltage value of the detection voltage not meeting the preset voltage range, and the gain amplification unit adjusts the gain of the light sensing voltage based on the gain control voltage.

[0013] In an embodiment, the gain control module comprises:

[0014] a timing controller connected with the sampling module, the timing controller outputs a pulse width modulation signal in response to the voltage value of the detection voltage not meeting the preset voltage range;

[0015] a low-pass filter connected with the timing controller, configured to filter out high-order harmonics in the pulse width modulation signal and output a direct current voltage corresponding to a direct current component in the pulse width modulation signal;

[0016] wherein the voltage value of the direct current voltage is positively correlated with the duty cycle of the pulse width modulation signal, and the voltage value of the gain control voltage output by the gain control module is related to the voltage value of the direct current voltage.

[0017] In an embodiment, the control voltage of the gain amplification unit is a negative voltage, and the gain control module further comprises:

[0018] a voltage inversion circuit connected with the low-pass filter and the gain amplification module, the voltage inversion circuit being configured to perform voltage inversion on the direct current voltage output by the low-pass filter and output the voltage inversion result as the gain control voltage to the gain amplification unit.

[0019] In an embodiment, the low-pass filter is a second-order low-pass filter, and the low-pass filter comprises a first resistor, a second resistor, a first capacitor and a second capacitor; wherein a first end of the first resistor is connected with the timing controller, a second end of the first resistor, a first end of the first capacitor and a first end of the second resistor are connected at a first node, a second end of the second resistor and a first end of the second capacitor are connected at a second node, the second node serving as an output end of the low-pass filter, and a second end of the first capacitor and a second end of the second capacitor are grounded.

[0020] In an embodiment, the voltage inversion circuit comprises a voltage follower and an inverter;

[0021] the voltage follower comprises a first operational amplifier, a positive input end of the first operational amplifier is connected with the second node, and the positive input end of the first operational amplifier is also connected with an output end of the first operational amplifier, and a negative input end of the first operational amplifier is grounded;

[0022] The inverter comprises a third resistor, a fourth resistor, a fifth resistor and a second operational amplifier; wherein a first end of the third resistor is connected to an output end of the first operational amplifier, a second end of the third resistor, a first end of the fourth resistor and a negative input end of the second operational amplifier are connected to a third node, a second end of the fourth resistor is connected to an output end of the second operational amplifier, the output end of the second operational amplifier serves as an output end of the voltage inversion circuit, a positive input end of the second operational amplifier is connected to a first end of the fifth resistor, and a second end of the fifth resistor is grounded.

[0023] In an embodiment, the voltage conversion unit comprises a sixth resistor, a third capacitor and a third operational amplifier; wherein a first end of the sixth resistor, a first end of the third capacitor and a negative input end of the third operational amplifier are connected to a fourth node, the fourth node is used for receiving the light sensing current, a second end of the sixth resistor, a second end of the third capacitor and an output end of the third operational amplifier are connected to a fifth node, the fifth node serves as an output end of the voltage conversion unit and is used for outputting the light sensing voltage, and a positive input end of the third operational amplifier is grounded.

[0024] The gain amplification unit comprises a first gain amplification unit, the first gain amplification unit comprises a gain amplification chip and a seventh resistor, a non-inverting input end of the gain amplification chip is coupled to the fifth node, a control end of the gain amplification chip is connected to an output end of the gain control module and is used for receiving the gain control voltage, an inverting input end of the gain amplification chip is connected to a first end of the seventh resistor, a second end of the seventh resistor is grounded, and an output end of the gain amplification chip is connected to the sampling module.

[0025] In an embodiment, the gain amplification unit comprises a second gain amplification unit, the second gain amplification unit is connected between the voltage conversion unit and the first gain amplification unit; wherein the second gain amplification unit comprises an eighth resistor, a ninth resistor and a fourth operational amplifier, a first end of the eighth resistor is connected to the fifth node, a second end of the eighth resistor, a first end of the ninth resistor and a negative input end of the fourth operational amplifier are connected to a sixth node, a second end of the ninth resistor, an output end of the fourth operational amplifier and a non-inverting input end of the gain amplification chip are connected to a seventh node, and a positive input end of the fourth operational amplifier is grounded.

[0026] To solve the above problems, a second technical solution provided by the present application is to provide a light sensing current automatic adjustment method, comprising:

[0027] obtaining a detection voltage corresponding to the light sensing current collected by the sampling module;

[0028] in response to the voltage value of the detection voltage not meeting the preset voltage range, output a gain control voltage for a gain amplification unit in the gain amplification module, so that the gain amplification unit adjusts the gain of the light sensing voltage converted from the light sensing current based on the gain control voltage;

[0029] in response to the detection voltage corresponding to the light sensing current collected by the sampling module meeting the preset voltage range, adjusting the light based on the detection voltage.

[0030] In an embodiment, in response to the voltage value of the detection voltage not meeting the preset voltage range, output a gain control voltage for a gain amplification unit in the gain amplification module, comprising:

[0031] in response to the voltage value of the detection voltage being less than the preset voltage range, increasing the duty cycle of the pulse width modulation signal output to the low pass filter to change the gain control voltage, so that the gain amplification unit increases the gain of the light sensing voltage based on the changed gain control voltage;

[0032] in response to the voltage value of the detection voltage being greater than the preset voltage range, reducing the duty cycle of the pulse width modulation signal output to the low pass filter to change the gain control voltage, so that the gain amplification unit reduces the gain of the light sensing voltage based on the changed gain control voltage.

[0033] To solve the above problems, the third technical solution provided by the present application is to provide a display panel, comprising:

[0034] a sensing element for detecting the intensity of ambient light around the display panel and generating a corresponding light sensing current based on the intensity of ambient light around the display panel;

[0035] a light sensing current automatic adjustment gain circuit connected to the sensing element for receiving the light sensing current; wherein the light sensing current automatic adjustment gain circuit is any one of the light sensing current automatic adjustment gain circuits described above.

[0036] The beneficial effects of the present application are that, unlike the prior art, the light sensing current automatic adjustment gain circuit provided by the present application sets a gain control module and a gain amplification module. The gain control module outputs a gain control voltage for a gain amplification unit in the gain amplification module in response to the voltage value of the detection voltage fed back by the light sensing current not meeting the preset voltage range, so that the gain control unit adjusts the gain of the light sensing voltage based on the gain control voltage, thereby stabilizing the detection voltage within the preset voltage range and ensuring the stability of signal acquisition. Moreover, the present application can be compatible with different models. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative effort based on these drawings.

[0038] Fig. 1 is a structural block diagram of an embodiment of the gain circuit with automatic adjustment of light sensing current provided by the present application;

[0039] Fig. 2 is a structural block diagram of an embodiment of the gain control module provided by the present application;

[0040] Fig. 3 is a circuit schematic diagram of an embodiment of the gain control module provided by the present application;

[0041] Fig. 4 is a circuit schematic diagram of an embodiment of the gain amplification module provided by the present application;

[0042] Fig. 5 is a flowchart of an embodiment of the method for automatic adjustment of light sensing current provided by the present application;

[0043] Fig. 6 is a structural block diagram of an embodiment of the display panel provided by the present application.

[0044] Label explanation: gain amplification module-10; voltage conversion unit-11; sixth resistor-R6; third capacitor-C3; third operational amplifier-U3; gain amplification unit-12; first gain amplification unit-121; gain amplification chip-IC; seventh resistor-R7; second gain amplification unit-122; eighth resistor-R8; ninth resistor-R9; fourth operational amplifier-U4; sampling module-20; gain control module-30; timing controller-31; low-pass filter-32; first resistor-R1; second resistor-R2; first capacitor-C1; second capacitor-C2; voltage inversion circuit-33; voltage follower-331; first operational amplifier-U1; inverter-332; third resistor-R3; fourth resistor-R4; fifth resistor-R5; second operational amplifier-U2; light sensing current-I; light sensing voltage-V; detection voltage-VOUT; gain control voltage-VG; first node-n1; second node-n2; third node-n3; fourth node-n4; fifth node-n5; sixth node-n6; seventh node-n7; display panel-1000; sensing element-100; gain circuit with automatic adjustment of light sensing current-200.

DETAILED DESCRIPTION

[0045] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0046] The terms "first", "second", "third", etc. in the present application are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second", "third" can explicitly or implicitly include at least one of the features.

[0047] In this document, the term "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily independent or alternative embodiments to other embodiments. A person of ordinary skill in the art explicitly and implicitly understands that the embodiments described herein can be combined with other embodiments.

[0048] Referring to FIGS. 1-4, FIG. 1 is a structural block diagram of an embodiment of a light-sensing current automatic regulation gain circuit provided by the present application; FIG. 2 is a structural block diagram of an embodiment of a gain control module provided by the present application; FIG. 3 is a circuit schematic diagram of an embodiment of the gain control module provided by the present application; and FIG. 4 is a circuit schematic diagram of an embodiment of a gain amplification module provided by the present application.

[0049] Specifically, the present application provides a light-sensing current automatic regulation gain circuit, which comprises a gain amplification module 10 and a sampling module 20 (ADC).

[0050] The gain amplification module 10 comprises a voltage conversion unit 11 and a gain amplification unit 12. The voltage conversion unit 11 is configured to receive a light-sensing current I and convert the light-sensing current I into a light-sensing voltage V. The gain amplification unit 12 is connected to the voltage conversion unit 11 and the sampling module 20, and configured to output a detection voltage VOUT obtained by gain amplification of the light-sensing voltage V to the sampling module 20. The sampling module 20 is configured to collect the detection voltage VOUT corresponding to the light-sensing current I.

[0051] However, in a scenario, sometimes the value of the light-sensing current I is very small, and even if the gain amplification unit 12 performs gain amplification on the light-sensing current I, there will be a situation that is not conducive to the collection of the ADC module, thereby a large error will be generated, and the gain amplification unit 12 blindly increases the signal amplification multiple, which will have the risk of exceeding the safe voltage of the driving circuit.

[0052] To solve the above problems, the gain circuit further comprises a gain control module 30 connected between the sampling module 20 and the gain amplification module 10, wherein the gain control module 30 outputs a gain control voltage VG to the gain amplification unit 12 in response to the voltage value of the detection voltage VOUT detected by the sampling module 20 not meeting the preset voltage range, so that the gain amplification unit 12 adjusts the gain of the light sensing voltage V based on the gain control voltage VG, thereby stabilizing the detection voltage VOUT within the preset voltage range and ensuring the stability of signal acquisition.

[0053] In addition, since the gain control voltage VG can make the gain amplification unit 12 adjust the gain of the light sensing voltage V, and further stabilize the output detection voltage VOUT within the preset voltage range, the gain circuit provided by the application can be compatible even for different models through the adjustment of the gain control voltage VG.

[0054] In the embodiment of the application, referring to FIG. 4, the voltage conversion unit 11 comprises a sixth resistor R6, a third capacitor C3 and a third operational amplifier U3; wherein the first end of the sixth resistor R6, the first end of the third capacitor C3 and the negative input end of the third operational amplifier U3 are connected at a fourth node n4 for receiving the light sensing current I, the second end of the sixth resistor R6, the second end of the third capacitor C3 and the output end of the third operational amplifier U3 are connected at a fifth node n5 as the output end of the voltage conversion unit 11 for outputting the light sensing voltage V, and the positive input end of the third operational amplifier U3 is grounded.

[0055] In the embodiment of the application, please continue to refer to FIG. 4, the gain amplification unit 12 comprises a first gain amplification unit 121, which comprises a gain amplification chip IC and a seventh resistor R7, the non-inverting input end of the gain amplification chip IC is coupled to the fifth node n5, the control end of the gain amplification chip IC is connected to the output end of the gain control module 30 (specifically the second operational amplifier U2) for receiving the gain control voltage VG, so that the first gain amplification unit 121 adjusts the gain of the light sensing voltage V based on the gain control voltage VG, thereby stabilizing the detection voltage VOUT within the preset voltage range and ensuring the stability of signal acquisition, the inverting input end of the gain amplification chip IC is connected to the first end of the seventh resistor R7, the second end of the seventh resistor R7 is grounded, and the output end of the gain amplification chip IC is connected to the sampling module 20.

[0056] Further, please continue to refer to FIG. 4, in the embodiment of the present application, the gain amplification unit 12 comprises a second gain amplification unit 122, which is connected between the voltage conversion unit 11 and the first gain amplification unit 121. The second gain amplification unit 122 can be an OP pre-stage amplifier, which can perform signal conditioning and gain boosting on the light-sensing voltage V, and can protect the subsequent circuit, thereby ensuring the quality of the signal. Specifically, the second gain amplification unit 122 comprises an eighth resistor R8, a ninth resistor R9, and a fourth operational amplifier U4. The first end of the eighth resistor R8 is connected to the fifth node n5, the second end of the eighth resistor R8, the first end of the ninth resistor R9, and the negative input end of the fourth operational amplifier U4 are connected to the sixth node n6, the second end of the ninth resistor R9, the output end of the fourth operational amplifier U4, and the in-phase input end of the gain amplification chip IC are connected to the seventh node n7, and the positive input end of the fourth operational amplifier U4 is grounded.

[0057] Specifically, the light-sensing current I is input into the voltage conversion unit 11 to convert the current signal into a voltage signal, and the light-sensing voltage V has a value of -I x R6. Then, the light-sensing voltage V is input into the second gain amplification unit 122, which has a gain of -R9 / R8. The amplified voltage is then input into the first gain amplification unit 121, which has a gain that can be controlled by the VG voltage to achieve a preset gain variation range. For example, when the VG voltage is 0-2V, the gain variation range is -40db-40db, the gain is -40db when the VG voltage is 0V, and the gain is 40db when the VG voltage is -2V. The maximum gain of the detection voltage VOUT output by the second gain amplification unit 122 to the ADC for collection is (the gain of the second gain amplification unit 122) x (the gain of the first gain amplification unit 121).

[0058] In the embodiment of the present application, referring to FIGS. 2 and 3, the gain control module 30 comprises a timing controller 31 and a low-pass filter 32. The timing controller 31 is connected to the sampling module 20, and the timing controller 31 outputs a pulse width modulation signal (PWM) in response to the voltage value of the detection voltage VOUT not meeting the preset voltage range. The low-pass filter 32 is connected to the timing controller 31, and is used to filter out the high-order harmonics in the pulse width modulation signal and output a direct current voltage corresponding to the direct current component in the corresponding pulse width modulation signal. The voltage value of the direct current voltage is positively correlated with the duty cycle of the pulse width modulation signal.

[0059] Specifically, for the process of converting the PWM wave into a direct current voltage, the FFT analysis (Fast Fourier Transform) can be performed. It is known that when the PWM wave level is the same and the frequency is the same, the high-order harmonic components are also the same, but the duty cycle difference will lead to different direct current components, and the size of the direct current component is equal to the voltage x high-level duty cycle. If the high-order harmonic can be filtered out by the low-pass filter 32, the required direct current component can be obtained, thereby obtaining the direct current voltage.

[0060] In an experiment, the high level of the PWM wave is 3.3V, the low level is 0V, and the duty cycle is 54%. After filtering out the high-order harmonic by the low-pass filter 32, the obtained direct current voltage is about 1.78V.

[0061] The low-pass filter 32 can be a first-order, second-order or third-order low-pass filter. In the embodiment of the application, considering the circuit cost and the filtering effect of the high-order harmonic, the low-pass filter 32 is set to a second-order low-pass filter.

[0062] Specifically, the low-pass filter 32 includes a first resistor R1, a second resistor R2, a first capacitor C1 and a second capacitor C2. The first end of the first resistor R1 is connected to the timing controller 31, the second end of the first resistor R1, the first end of the first capacitor C1 and the first end of the second resistor R2 are connected to the first node n1, the second end of the second resistor R2 and the first end of the second capacitor C2 are connected to the second node n2, the second node n2 is used as the output end of the low-pass filter 32 and is used for outputting the direct current voltage, and the second end of the first capacitor C1 and the second end of the second capacitor C2 are grounded.

[0063] The voltage value of the gain control voltage VG output by the gain control module 30 is related to the voltage value of the direct current voltage.

[0064] Specifically, when the control voltage of the gain amplification unit 12 is a positive voltage, the voltage output by the timing controller 31 is also a positive voltage, so the voltage value of the gain control voltage VG output by the gain control module 30 is positively related to the direct current voltage.

[0065] When the control voltage of the gain amplification unit 12 is a negative voltage, the timing controller 31 cannot output a negative voltage, so the obtained direct current voltage is positive, and the direct current voltage needs to be converted into a negative voltage, so the voltage value of the gain control voltage VG output by the gain control module 30 is negatively related to the voltage value of the direct current voltage.

[0066] Wherein, the application takes the VCA810 chip as an example, the VCA810 chip is taken as the first gain amplification unit 121, the control voltage of the VCA810 chip is a negative voltage, in order to convert the direct current voltage into a negative voltage, please refer to Figure 3, the gain control module 30 also needs to include a voltage inversion circuit 33, wherein the voltage inversion circuit 33 is connected with the low pass filter 32 and the gain amplification module 10, the voltage inversion circuit 33 is used for voltage inversion of the direct current voltage output by the low pass filter 32 as the gain control voltage VG, and output to the gain amplification unit 12.

[0067] In the embodiment of the application, the voltage inversion circuit 33 includes a voltage follower 331 and an inverter 332.

[0068] Wherein, the voltage follower 331 includes a first operational amplifier U1, the positive input end of the first operational amplifier U1 is connected with the second node n2, and the positive input end of the first operational amplifier U1 is also connected with the output end of the first operational amplifier U1, and the negative input end of the first operational amplifier U1 is grounded; the inverter 332 includes a third resistor R3, a fourth resistor R4, a fifth resistor R5 and a second operational amplifier U2; wherein the first end of the third resistor R3 is connected with the output end of the first operational amplifier U1, the second end of the third resistor R3, the first end of the fourth resistor R4 and the negative input end of the second operational amplifier U2 are connected at the third node n3, the second end of the fourth resistor R4 is connected with the output end of the second operational amplifier U2, the output end of the second operational amplifier U2 is taken as the output end of the voltage inversion circuit 33, the positive input end of the second operational amplifier U2 is connected with the first end of the fifth resistor R5, and the second end of the fifth resistor R5 is grounded.

[0069] Specifically, the voltage follower 331 is arranged between the inverter 332 and the low pass filter 32, the voltage follower 331 can be used as a buffer between the front and rear circuits, and meanwhile the load of the inverter 332 will not affect the characteristics of the low pass filter 32; in addition, the voltage follower 331 can almost without distortion transmit the signal (direct current voltage) output by the low pass filter 32 to the inverter 332, and the integrity and precision of the signal are maintained.

[0070] Specifically, the gain circuit provided by the application can automatically adjust the light sensing current, by arranging the gain control module 30 and the gain amplification module 10, the gain control module 30 outputs the gain control voltage VG to the gain amplification unit 12 in the gain amplification module 10 in response to the voltage value of the detection voltage VOUT fed back by the light sensing current I not conforming to the preset voltage range, so that the gain control unit adjusts the gain of the light sensing voltage V based on the gain control voltage VG, thereby stabilizing the detection voltage VOUT in the preset voltage range, ensuring the stability of signal acquisition, and even for different models, and compatibility can be achieved.

[0071] Referring to FIG. 5, which is a flowchart of an embodiment of the method for automatically adjusting the light-sensing current provided by the present application, the present application also provides a method for automatically adjusting the light-sensing current, comprising:

[0072] Step S1: obtaining the detection voltage VOUT corresponding to the light-sensing current I collected by the sampling module 20.

[0073] Specifically, the gain amplification module 10 is configured to convert the light-sensing current I into the light-sensing voltage V and configured to output the detection voltage VOUT obtained by gain processing the light-sensing voltage V to the sampling module 20, so that the gain control module 30 can obtain the detection voltage VOUT corresponding to the light-sensing current I collected by the sampling module 20.

[0074] In order to prevent the light-sensing adjustment from being triggered by mistake in daily life, such as the display device being temporarily blocked, or the ambient light being temporarily changed, etc., in an embodiment, after the detection voltage VOUT is obtained for the first time in each detection process, the detection voltage VOUT corresponding to the light-sensing current I collected by the sampling module 20 is obtained again after a first preset delay time as a reference voltage; in response to the difference between the detection voltage VOUT and the reference voltage being greater than a preset threshold, it is determined that the light-sensing adjustment is triggered by mistake, and the next round of sampling is entered.

[0075] The first preset delay time can be designed according to actual needs, and in the present application, the first preset delay time can be 20 ms, 80 ms, 200 ms, or 1 s, etc.

[0076] Specifically, after the time sequence controller 31 receives the detection voltage VOUT sampled by the sampling module 20 for the first time, the time sequence controller 31 delays for the first preset delay time, and then performs second sampling; if the voltage sampled for the second time is different from the voltage sampled for the first time by n times (such as 10 times, 20 times, etc.), the light-sensing adjustment is not performed this time, and the next round of sampling is performed.

[0077] Step S2: in response to the voltage value of the detection voltage VOUT not meeting the preset voltage range, outputting the gain control voltage VG to the gain amplification unit 12 in the gain amplification module 10, so that the gain amplification unit 12 adjusts the gain of the light-sensing voltage V converted from the light-sensing current I based on the gain control voltage VG.

[0078] Specifically, step S2 comprises: in response to the voltage value of the detection voltage VOUT being less than the preset voltage range, increasing the duty cycle of the pulse width modulation signal output to the low-pass filter 32, so as to change the gain control voltage VG, so that the gain amplification unit 12 increases the gain of the light-sensing voltage V based on the changed gain control voltage VG.

[0079] In response to the voltage value of the detection voltage VOUT being greater than the preset voltage range, the duty cycle of the pulse width modulation signal output to the low pass filter 32 is reduced to change the gain control voltage VG, so that the gain amplification unit 12 reduces the gain of the light sensing voltage V based on the changed gain control voltage VG.

[0080] Specifically, the reference voltage U can be set, and the preset voltage range is 0.5U-0.9U. When VOUT is less than 0.5U, it is determined that the amplitude is too small and does not meet the preset voltage range, and the high level duty cycle of the PWM wave output by the timing controller 31 is increased, for example, by 1%, 5%, or 10%, etc., to increase the amplification gain of the first gain amplification unit 121. When VOUT is greater than 0.9U, it is determined that the amplitude is too large and does not meet the preset voltage range, and the high level duty cycle of the PWM wave output by the timing controller 31 is reduced, for example, by 1%, 5%, or 10%, etc., to reduce the amplification gain of the first gain amplification unit 121. This cycle can keep VOUT within the range of 0.5U1-0.9U1, and can be compatible with different models to ensure the stability of signal acquisition.

[0081] Wherein, VOUT / (amplification multiple of the first gain amplification unit 121) x (amplification multiple of the second gain amplification unit 122) is the light sensing voltage V, and the light sensing current I is the light sensing voltage V / R6. The display brightness is adjusted according to the light sensing current I.

[0082] It should be noted that since the low pass filter 32 has a certain delay on the signal, the gain control voltage VG does not reach the set voltage during this delay time. If VOUT is sampled immediately when the PWM wave is turned on, the voltage value of the sampled VOUT will not be consistent with the actual stable voltage value. Therefore, when the gain control voltage VG is used to adjust the gain of the light sensing voltage V, the sampling of VOUT needs to be delayed for a preset time after the PWM wave is turned on.

[0083] Step S3: In response to the detection voltage VOUT corresponding to the light sensing current I collected by the sampling module 20 meeting the preset voltage range, the light is adjusted based on the detection voltage VOUT.

[0084] Specifically, if the light sensing current I corresponding to the detection voltage VOUT obtained after the gain control voltage VG is used to adjust the gain of the light sensing voltage V meets the preset voltage range, or the initial detection voltage VOUT meets the preset voltage range, the light is adjusted based on the detection voltage VOUT.

[0085] Specifically, the method for automatically adjusting the light-sensing current provided in the present application outputs a gain control voltage VG for the gain amplification unit 12 in the gain amplification module 10 in response to the voltage value of the detection voltage VOUT not meeting the preset voltage range, so that the gain amplification unit 12 adjusts the gain of the light-sensing voltage V converted from the light-sensing current I based on the gain control voltage VG, thereby stabilizing the detection voltage VOUT in the preset voltage range and ensuring the stability of signal acquisition, and even for different models, and compatibility can be achieved.

[0086] Referring to FIG. 6, FIG. 6 is a structural block diagram of an embodiment of a display panel provided in the present application.

[0087] Specifically, the present application also provides a display panel 1000, which comprises a sensing element 100 and a gain circuit 200 for automatically adjusting the light-sensing current.

[0088] The sensing element 100 is configured to detect the intensity of ambient light around the display panel 1000 and generate a corresponding light-sensing current I based on the intensity of ambient light around the display panel 1000.

[0089] In some embodiments, the sensing element 100 is a light-sensing element (ALS), such as an a-Si TFT (Amorphous Silicon Thin Film Transistor), which will generate different leakage currents (i.e., light-sensing currents I) according to different light intensities.

[0090] The a-Si TFT can be integrated in the periphery of the display panel 1000, so that the ambient illuminance around the panel can be sensed without using external light-sensing devices.

[0091] The gain circuit 200 for automatically adjusting the light-sensing current is connected to the sensing element 100 and configured to receive the light-sensing current I output by the sensing element 100. The gain circuit 200 for automatically adjusting the light-sensing current is the gain circuit 200 for automatically adjusting the light-sensing current provided in any of the above embodiments, which ensures the stability of signal acquisition, and even for different models, and compatibility can be achieved.

[0092] In some embodiments, the display panel 1000 can be applied to the fields of mobile phones, televisions, computers, notebooks, smart wearable devices, etc., thereby improving the user experience of using the above-mentioned electronic devices with display functions, and achieving the purposes of reducing device power consumption, prolonging device service life, protecting user eyes, etc.

[0093] The above merely describes the embodiments of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation, or direct or indirect application in other related technical fields, which is made by using the content of the present application specification and drawings, is also included in the patent protection scope of the present application.

Claims

1. A light-sensing current self-regulating gain circuit, wherein, The application relates to a light sensing circuit, comprising: a sampling module for collecting a detection voltage corresponding to a light sensing current; a gain control module connected to the sampling module for outputting a gain control voltage; a gain amplification module comprising a voltage conversion unit and a gain amplification unit, the voltage conversion unit being used for receiving the light sensing current and converting the light sensing current into a light sensing voltage; the gain amplification unit being connected to the voltage conversion unit and the sampling module and being used for outputting the detection voltage to the sampling module after gain amplification of the light sensing voltage; wherein the gain amplification module is further connected to the gain control module, and the gain control module outputs a gain control voltage to the gain amplification unit in response to the voltage value of the detection voltage not meeting a preset voltage range; the gain amplification unit adjusts the gain of the light sensing voltage based on the gain control voltage.

2. The gain circuit of claim 1, wherein, The gain control module comprises: a timing controller connected to the sampling module, the timing controller outputting a pulse width modulation signal in response to the voltage value of the detection voltage not meeting the preset voltage range; a low-pass filter connected to the timing controller and used for filtering high-order harmonics in the pulse width modulation signal and outputting a direct current voltage corresponding to a direct current component in the pulse width modulation signal; wherein the voltage value of the direct current voltage is positively correlated with the duty cycle of the pulse width modulation signal; and the voltage value of the gain control voltage output by the gain control module is related to the voltage value of the direct current voltage.

3. The gain circuit of claim 2, wherein, The timing controller increases the duty cycle of the pulse width modulation signal output to the low-pass filter in response to the voltage value of the detection voltage being less than the preset voltage range, so as to change the gain control voltage and make the gain amplification unit increase the gain of the light sensing voltage based on the changed gain control voltage; The timing controller decreases the duty cycle of the pulse width modulation signal output to the low-pass filter in response to the voltage value of the detection voltage being greater than the preset voltage range, so as to change the gain control voltage and make the gain amplification unit decrease the gain of the light sensing voltage based on the changed gain control voltage.

4. The gain circuit of claim 2, wherein, The voltage value of the gain control voltage output by the gain control module is positively correlated with the voltage value of the direct current voltage; or The voltage value of the gain control voltage output by the gain control module is negatively correlated with the voltage value of the direct current voltage.

5. The gain circuit of claim 2, wherein, The control voltage of the gain amplification unit is a negative voltage, and the gain control module further comprises: a voltage inversion circuit connected to the low-pass filter and the gain amplification module, the voltage inversion circuit being used for inverting the direct current voltage output by the low-pass filter to serve as the gain control voltage and outputting the gain control voltage to the gain amplification unit.

6. The gain circuit of claim 2, wherein, The low-pass filter is a first-order low-pass filter; or The low-pass filter is a second-order low-pass filter; or The low-pass filter is a third-order low-pass filter.

7. The gain circuit of claim 5, wherein, The low-pass filter is a second-order low-pass filter, and the low-pass filter comprises a first resistor, a second resistor, a first capacitor and a second capacitor; wherein a first end of the first resistor is connected to the time sequence controller, a second end of the first resistor, a first end of the first capacitor and a first end of the second resistor are connected to a first node, a second end of the second resistor and a first end of the second capacitor are connected to a second node, the second node serves as an output end of the low-pass filter, and a second end of the first capacitor and a second end of the second capacitor are grounded.

8. The gain circuit of claim 7, wherein, The voltage inversion circuit comprises a voltage follower and an inverter; The voltage follower comprises a first operational amplifier, a positive input end of the first operational amplifier is connected to the second node, and the positive input end of the first operational amplifier is also connected to an output end of the first operational amplifier, and a negative input end of the first operational amplifier is grounded. The inverter comprises a third resistor, a fourth resistor, a fifth resistor and a second operational amplifier; wherein a first end of the third resistor is connected to the output end of the first operational amplifier, a second end of the third resistor, a first end of the fourth resistor and a negative input end of the second operational amplifier are connected to a third node, a second end of the fourth resistor is connected to an output end of the second operational amplifier, the output end of the second operational amplifier serves as an output end of the voltage inversion circuit, a positive input end of the second operational amplifier is connected to a first end of the fifth resistor, and a second end of the fifth resistor is grounded.

9. The gain circuit of any of claims 2-8, wherein, The voltage conversion unit comprises a sixth resistor, a third capacitor and a third operational amplifier; wherein a first end of the sixth resistor, a first end of the third capacitor and a negative input end of the third operational amplifier are connected to a fourth node, the fourth node is used for receiving the light sensing current, a second end of the sixth resistor, a second end of the third capacitor and an output end of the third operational amplifier are connected to a fifth node, the fifth node serves as an output end of the voltage conversion unit and is used for outputting the light sensing voltage, and a positive input end of the third operational amplifier is grounded. The gain amplification unit comprises a first gain amplification unit, the first gain amplification unit comprises a gain amplification chip and a seventh resistor, a non-inverting input end of the gain amplification chip is coupled to the fifth node, a control end of the gain amplification chip is connected to an output end of the gain control module and is used for receiving the gain control voltage, an inverting input end of the gain amplification chip is connected to a first end of the seventh resistor, a second end of the seventh resistor is grounded, and an output end of the gain amplification chip is connected to the sampling module.

10. The gain circuit of claim 9, wherein, The gain amplification chip comprises a VCA810 chip.

11. The gain circuit of claim 9, wherein, The gain amplification unit comprises a second gain amplification unit connected between the voltage conversion unit and the first gain amplification unit; wherein the second gain amplification unit comprises an eighth resistor, a ninth resistor and a fourth operational amplifier, a first end of the eighth resistor is connected to the fifth node, a second end of the eighth resistor, a first end of the ninth resistor and a negative input end of the fourth operational amplifier are connected to a sixth node, a second end of the ninth resistor, an output end of the fourth operational amplifier and a non-inverting input end of the gain amplification chip are connected to a seventh node, and a positive input end of the fourth operational amplifier is grounded.

12. A method of light-sensing current auto-regulation, wherein, Comprise: The detection voltage corresponding to the light sensing current collected by the sampling module is acquired; In response to the voltage value of the detection voltage not meeting the preset voltage range, a gain control voltage is output to the gain amplification unit in the gain amplification module, so that the gain amplification unit adjusts the gain of the light sensing voltage converted by the light sensing current based on the gain control voltage; In response to the detection voltage corresponding to the light sensing current collected by the sampling module meeting the preset voltage range, dimming is performed based on the detection voltage.

13. The method of claim 12, wherein, The gain control voltage is output to the gain amplification unit in the gain amplification module in response to the voltage value of the detection voltage not meeting the preset voltage range, comprising: In response to the voltage value of the detection voltage being less than the preset voltage range, the duty cycle of the pulse width modulation signal output to the low pass filter is increased to change the gain control voltage, so that the gain amplification unit increases the gain of the light sensing voltage based on the changed gain control voltage; In response to the voltage value of the detection voltage being greater than the preset voltage range, the duty cycle of the pulse width modulation signal output to the low pass filter is reduced to change the gain control voltage, so that the gain amplification unit reduces the gain of the light sensing voltage based on the changed gain control voltage.

14. The method of claim 12, wherein, Before acquiring the detection voltage corresponding to the light sensing current collected by the sampling module, further comprising: In each detection process, after acquiring the detection voltage for the first time, the detection voltage corresponding to the light sensing current collected by the sampling module is acquired again as a reference voltage after a first preset delay time; In response to the difference between the detection voltage and the reference voltage being greater than a preset threshold, it is determined that it is a false trigger, and the next round of sampling is entered.

15. The method of claim 12, wherein, The preset voltage range is 0.5U-0.9U, wherein U is a set reference voltage.

16. The method of claim 12, wherein, The first preset delay time is 20ms, 80ms, 200ms or 1s.

17. The method of claim 12, wherein, After outputting the gain control voltage to the gain amplification unit in the gain amplification module, the sampling of the detection voltage is delayed for a preset time.

18. A display panel, wherein, Comprise: A sensing element for detecting the intensity of ambient light around the display panel and generating a corresponding light sensing current based on the intensity of ambient light around the display panel; A light sensing current automatic adjustment gain circuit connected to the sensing element for receiving the light sensing current; wherein the light sensing current automatic adjustment gain circuit is the light sensing current automatic adjustment gain circuit of any one of claims 1-11.

19. The display panel of claim 18, wherein, The sensing element is an amorphous silicon thin film transistor.

20. The display panel of claim 18, wherein, The sensing element is integrated in the periphery of the display panel.

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