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

Abstract

The application provides a gain circuit, a method and a display panel for automatically adjusting a light-sensing current, the gain circuit comprising a sampling module, a gain control module and a gain amplification module, wherein the sampling module is configured to collect a detection voltage corresponding to the light-sensing current; the gain control module is connected to the sampling module and configured to output a gain control voltage; the gain amplification module comprises 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 configured to output 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, the gain control module outputs the gain control voltage to the gain amplification unit in response to the voltage value of the detection voltage not meeting a preset voltage range, and the gain amplification unit adjusts the gain of the light-sensing voltage based on the gain control voltage.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of circuit, in particular to a gain circuit for automatically adjusting light-sensing current, a method and a display panel. BACKGROUND

[0002] In the field of display circuit, ambient light sensing element (ALS) will generate different light-sensing currents according to different light intensities, and feedback to the acquisition module (ADC), and then adjust the picture to reduce power consumption, protect eyes, prolong life, etc.

[0003] 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.

[0004] Therefore, the prior art needs to be improved. SUMMARY

[0005] To solve the above problems, the present application provides a gain circuit for automatically adjusting light-sensing current, a method and a display panel, which can improve the error when the light-sensing current is fed back to the acquisition module, and can avoid safety risks.

[0006] To solve the above problems, the first technical solution provided by the present application is to provide a gain circuit for automatically adjusting light-sensing current, comprising:

[0007] A sampling module for acquiring a detection voltage corresponding to the light-sensing current;

[0008] A gain control module connected to the sampling module for outputting a gain control voltage;

[0009] A gain amplification module including a voltage conversion unit and a gain amplification unit, the voltage conversion unit is used for receiving the light-sensing current and converting 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 used for outputting the detection voltage to the sampling module after gain amplification of the light-sensing voltage;

[0010] 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 the preset voltage range, and the gain amplification unit adjusts the gain of the light-sensing voltage based on the gain control voltage.

[0011] In an embodiment, the gain control module comprises:

[0012] a timing controller connected to the sampling module, the timing controller being configured to output a pulse width modulation signal in response to the detected voltage not meeting a preset voltage range;

[0013] a low pass filter connected to the timing controller, the low pass filter being 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;

[0014] wherein the direct current voltage is positively correlated to a duty cycle of the pulse width modulation signal, and the gain control voltage output by the gain control module is correlated to the direct current voltage.

[0015] In an embodiment, the control voltage of the gain amplification unit is a negative voltage, and the gain control module further comprises:

[0016] a voltage inverting circuit connected to the low pass filter and the gain amplification module, the voltage inverting circuit being configured to invert the direct current voltage output by the low pass filter and output the inverted direct current voltage as the gain control voltage to the gain amplification unit.

[0017] 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 to 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 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 serving as an output end of the low pass filter, a second end of the first capacitor and a second end of the second capacitor are grounded.

[0018] In an embodiment, the voltage inverting circuit comprises a voltage follower and an inverter;

[0019] the voltage follower comprises a first operational amplifier, a positive input end of the first operational amplifier being connected to the second node, and the positive input end of the first operational amplifier also being connected to an output end of the first operational amplifier, a negative input end of the first operational amplifier being grounded;

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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:

[0025] obtaining a detection voltage corresponding to the light sensing current collected by the sampling module;

[0026] 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;

[0027] 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.

[0028] 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:

[0029] 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;

[0030] 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.

[0031] To solve the above problems, the third technical solution provided by the present application is to provide a display panel, comprising:

[0032] 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;

[0033] 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 above light sensing current automatic adjustment gain circuits.

[0034] 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

[0035] 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 will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0036] Figure 1 The structural block diagram of an embodiment of the gain circuit for automatically adjusting the light sensing current provided by the present application;

[0037] Figure 2 The structural block diagram of an embodiment of the gain control module provided by the present application;

[0038] Figure 3 The circuit schematic diagram of an embodiment of the gain control module provided by the present application;

[0039] Figure 4 The circuit schematic diagram of an embodiment of the gain amplification module provided by the present application;

[0040] Figure 5 The flowchart of an embodiment of the method for automatically adjusting the light sensing current provided by the present application;

[0041] Figure 6 The structural block diagram of an embodiment of the display panel provided by the present application.

[0042] Label explanation:

[0043] 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;

[0044] Sampling module-20;

[0045] 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;

[0046] Light sensing current-I; light sensing voltage-V; detection voltage-VOUT; gain control voltage-VG;

[0047] First node - n1; second node - n2; third node - n3; fourth node - n4; fifth node - n5; sixth node - n6; seventh node - n7;

[0048] Display panel 1000; sensing element 100; gain circuit for automatically adjusting light-sensing current 200. DETAILED DESCRIPTION

[0049] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0050] The terms "first," "second," "third," etc., in this application are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first," "second," or "third" may explicitly or implicitly include at least one of such features.

[0051] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0052] See also Figures 1-4 , Figure 1 This is a structural block diagram of an embodiment of a gain circuit for automatic adjustment of light-sensing current provided by the present application; Figure 2 This is a structural block diagram of an embodiment of the gain control module provided by this application; Figure 3 A circuit diagram of an embodiment of a gain control module provided in this application; Figure 4 This is a circuit diagram of an embodiment of the gain amplification module provided in this application.

[0053] Specifically, the present application provides a gain circuit for automatically adjusting a light-sensing current, the gain circuit including a gain amplification module 10 and a sampling module 20 (ADC).

[0054] 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 the 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 a sampling module 20, and is configured to output the 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.

[0055] However, in a scenario, the value of the light sensing current I is sometimes very small, and even after the gain amplification unit 12 performs gain amplification on the light sensing current I, there is still a situation that is not conducive to the collection of the ADC module, thereby a large error is generated, and the gain amplification unit 12 blindly increases the signal amplification multiple, which has a risk of exceeding the safe voltage of the driving circuit.

[0056] To solve the above problems, the gain circuit further comprises a gain control module 30 connected to the sampling module 20 and the gain amplification module 10. 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 a 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 collection.

[0057] 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, even for different models, through the adjustment of the gain control voltage VG, the gain circuit provided by the present application can also achieve compatibility.

[0058] In the embodiment of the present application, referring to Figure 4 The voltage conversion unit 11 comprises a sixth resistor R6, a third capacitor C3 and a third operational amplifier U3. 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 to a fourth node n4, the fourth node n4 is configured to receive 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 to a fifth node n5, the fifth node n5 is used as the output end of the voltage conversion unit 11 and is configured to output the light sensing voltage V, and the positive input end of the third operational amplifier U3 is grounded.

[0059] In the embodiment of the present application, please continue to refer to Figure 4, the gain amplification unit 12 includes a first gain amplification unit 121, the first gain amplification unit 121 includes a gain amplification chip IC and a seventh resistor R7, the non-inverting input terminal of the gain amplification chip IC is coupled to the fifth node n5, the control terminal of the gain amplification chip IC is connected to the output terminal 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, so that the detection voltage VOUT is stabilized in the preset voltage range, ensuring the stability of signal acquisition, the inverting input terminal 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 terminal of the gain amplification chip IC is connected to the sampling module 20.

[0060] Further, in the embodiments of the present application, please continue to refer to Figure 4 , the gain amplification unit 12 includes a second gain amplification unit 122, which is connected between the voltage conversion unit 11 and the first gain amplification unit 121. Wherein, the second gain amplification unit 122 can be an OP pre-stage amplifier, which can perform signal conditioning and gain enhancement on the light sensing voltage V, and can protect the subsequent circuit, ensuring the quality of the signal. Specifically, the second gain amplification unit 122 includes 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 terminal of the fourth operational amplifier U4 are connected to the sixth node n6, the second end of the ninth resistor R9, the output terminal of the fourth operational amplifier U4 and the non-inverting input terminal of the gain amplification chip IC are connected to the seventh node n7, and the positive input terminal of the fourth operational amplifier U4 is grounded.

[0061] Specifically, the light sensing current I is input to the voltage conversion unit 11, the current signal is converted into a voltage signal, the light sensing voltage V is-IxR6, and then input to the second gain amplification unit 122, the amplification factor of the second gain amplification unit 122 is-R9 / R8, and then the amplified voltage is input to the first gain amplification unit 121, the gain of the first gain amplification unit 121 can be controlled by the VG voltage, and the gain variation range is preset, for example, the gain variation range of the VG voltage is 0- -2V, -40 db~ 40 db, the gain is-40 db when the VG voltage is 0V, and the gain is 40 db when the VG voltage is-2V, and the maximum amplification factor of the detection voltage VOUT finally output to the ADC acquisition by the second gain amplification unit 122 is (the amplification factor of the second gain amplification unit 122) x (the amplification factor of the first gain amplification unit 121).

[0062] In the embodiments of the present application, please refer to Figure 2 and Figure 3The 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 outputs a pulse width modulation signal (PWM) in response to the voltage value of the detection voltage VOUT not conforming to the preset voltage range. The low-pass filter 32 is connected to the timing controller 31 and is used 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. The voltage value of the direct current voltage is positively correlated with the duty cycle of the pulse width modulation signal.

[0063] Specifically, for the process of converting the PWM wave into the direct current voltage, FFT analysis (Fast Fourier Transform) can be performed. It can be 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 different duty cycles will lead to different direct current components, and the size of the direct current component is equal to the voltage multiplied by the high-level duty cycle. If the high-order harmonics can be filtered out by the low-pass filter 32, the required direct current component can be obtained, and thus the direct current voltage can be obtained.

[0064] 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 the high-order harmonics are filtered out by the low-pass filter 32, the obtained direct current voltage is about 1.78V.

[0065] 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 on the high-order harmonics, the low-pass filter 32 is set to a second-order low-pass filter.

[0066] Specifically, the low-pass filter 32 comprises 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 a first node n1. The second end of the second resistor R2 and the first end of the second capacitor C2 are connected to a second node n2. The second node n2 serves as an output end of the low-pass filter 32 and is used to output the direct current voltage. The second end of the first capacitor C1 and the second end of the second capacitor C2 are grounded.

[0067] 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.

[0068] 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, and thus the voltage value of the gain control voltage VG output by the gain control module 30 is positively correlated with the direct current voltage.

[0069] When the control voltage of the gain amplification unit 12 is a negative voltage, the DC voltage obtained is positive because the timing controller 31 cannot output a negative voltage, and the gain control voltage VG output by the gain control module 30 is negatively correlated with the voltage value of the DC voltage.

[0070] In the present application, the gain amplification unit 12 includes a VCA810 chip as an example, the VCA810 chip is used as the first gain amplification unit 121, the control voltage of the VCA810 chip is a negative voltage, and in order to convert the DC voltage into a negative voltage, please refer to Figure 3 , the gain control module 30 further includes a voltage inverting circuit 33, wherein the voltage inverting circuit 33 is connected to the low-pass filter 32 and the gain amplification module 10, and the voltage inverting circuit 33 is used to invert the DC voltage output by the low-pass filter 32 as the gain control voltage VG and output to the gain amplification unit 12.

[0071] In the embodiment of the present application, the voltage inverting circuit 33 includes a voltage follower 331 and an inverter 332.

[0072] The voltage follower 331 includes a first operational amplifier U1, the positive input terminal of the first operational amplifier U1 is connected to the second node n2, and the positive input terminal of the first operational amplifier U1 is also connected to the output terminal of the first operational amplifier U1, and the negative input terminal 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 to the output terminal 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 terminal of the second operational amplifier U2 are connected to the third node n3, the second end of the fourth resistor R4 is connected to the output terminal of the second operational amplifier U2, the output terminal of the second operational amplifier U2 is used as the output terminal of the voltage inverting circuit 33, the positive input terminal of the second operational amplifier U2 is connected to the first end of the fifth resistor R5, and the second end of the fifth resistor R5 is grounded.

[0073] 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 at the same time, 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 distortionlessly transmit the signal (DC voltage) output by the low-pass filter 32 to the inverter 332, and maintain the integrity and accuracy of the signal.

[0074] Specifically, the gain circuit for automatically adjusting the light-sensing current provided in the application is configured with a gain control module 30 and a gain amplification module 10. The gain control module 30 outputs a 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 meeting 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 within the preset voltage range and ensuring the stability of signal acquisition, and even for different models, compatibility can be achieved.

[0075] Referring to Figure 5 , Figure 5 The flowchart of an embodiment of the method for automatically adjusting the light-sensing current provided in the application, the application also provides a method for automatically adjusting the light-sensing current, comprising:

[0076] Step S1: obtaining the detection voltage VOUT corresponding to the light-sensing current I collected by the sampling module 20.

[0077] Specifically, the gain amplification module 10 is configured to convert the light-sensing current I into a light-sensing voltage V and output the light-sensing voltage V after gain to the detection voltage VOUT 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.

[0078] In order to prevent the light-sensing adjustment from being triggered by mistake in daily life, such as the display device being temporarily obscured, 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.

[0079] The first preset delay time is designed according to actual needs. In the application, the first preset delay time can be 20 ms, 80 ms, 200 ms, or 1 s, etc.

[0080] Specifically, after receiving the detection voltage VOUT sampled by the sampling module 20 for the first time, the time sequence controller 31 delays for a first preset delay time, and then performs secondary sampling. If the voltage sampled for the second time is different from the voltage sampled for the last 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.

[0081] Step S2: in response to the voltage value of the detection voltage VOUT not meeting the preset voltage range, output a gain control voltage VG for 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.

[0082] In the step S2, in response to the voltage value of the detection voltage VOUT being less than the preset voltage range, the duty cycle of the pulse width modulation signal output to the low pass filter 32 is increased 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.

[0083] 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.

[0084] Specifically, a reference voltage U can be set, and the preset voltage range is 0.5 U-0.9 U. When VOUT is less than 0.5 U, it is determined that the amplitude is too small and does not meet the preset voltage range, and the 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 0.9 U, it is determined that the amplitude is too large and does not meet the preset voltage range, and the 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 0.5 U1-0.9 U1, and can be compatible with different models to ensure the stability of signal acquisition.

[0085] In the formula, 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 voltage V / R6 is the light sensing current I. The display brightness is adjusted according to the light sensing current I.

[0086] It should be noted that the low pass filter 32 has a certain delay to the signal, and during this delay time, the VG does not reach the set voltage. If the 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 VOUT needs to be sampled after a preset time delay after the PWM wave is turned on.

[0087] 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, dimming is performed based on the detection voltage VOUT.

[0088] Specifically, if the detection voltage VOUT corresponding to the light-sensing current I 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, dimming is performed based on the detection voltage VOUT.

[0089] Specifically, the light-sensing current automatic adjustment method provided by the present application responds to the voltage value of the detection voltage VOUT not meeting the preset voltage range, and outputs a 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 by the light-sensing current I 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, and even for different models, and compatibility can be achieved.

[0090] Referring to Figure 6 , Figure 6 The structure block diagram of an embodiment of the display panel provided by the present application is shown.

[0091] Specifically, the present application also provides a display panel 1000, which comprises a sensing element 100 and a light-sensing current automatic adjustment gain circuit 200.

[0092] The sensing element 100 is used 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.

[0093] 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 current I) according to different light intensities.

[0094] 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.

[0095] The light-sensing current automatic adjustment gain circuit 200 is connected to the sensing element 100 and is used to receive the light-sensing current I output by the sensing element 100; the light-sensing current automatic adjustment gain circuit 200 is the light-sensing current automatic adjustment gain circuit provided by any of the above embodiments, which ensures the stability of signal acquisition, and even for different models, and compatibility can be achieved.

[0096] 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 use experience of users on the above-mentioned electronic devices with display functions, and being capable of achieving the purposes of reducing the power consumption of the devices, prolonging the service life of the devices, protecting the eyes of users, etc.

[0097] The above is only the implementation of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the specification and drawings of the present application, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A display panel, characterized in that: include: a sensing element, configured to detect the intensity of ambient light around the display panel and generate a corresponding light-sensing current based on the intensity of the ambient light around the display panel; A gain circuit for automatically adjusting the light-sensing current is connected to the sensing element and is used to receive the light-sensing current; wherein the gain circuit for automatically adjusting the light-sensing current includes: Sampling module, used to collect the detection voltage corresponding to the light-sensing current; A gain control module, connected to the sampling module, configured to output a gain control voltage; a gain amplification module, comprising a voltage conversion unit and a gain amplification unit, wherein the voltage conversion unit is used 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 used to gain the light-sensing voltage and then output the detection voltage to the sampling module; The gain amplification module is further connected to the gain control module. In response to the voltage value of the detection voltage not being within a preset voltage range, the gain control module outputs a gain control voltage to the gain amplification unit. The gain amplification unit adjusts the gain of the light-sensing voltage based on the gain control voltage. Wherein, the gain control module includes: a timing controller connected to the sampling module, and outputting a pulse width modulation signal in response to the voltage value of the detection voltage not being within a preset voltage range; wherein, in each round of detection, after the timing controller first acquires the detection voltage, it again acquires the detection voltage corresponding to the light-sensing current acquired by the sampling module after a first preset delay time as a reference voltage; and in response to the difference between the detection voltage and the reference voltage being greater than a preset threshold, it is determined to be a false trigger, and the next round of sampling is entered; a low-pass filter connected to the timing controller, configured to filter out higher harmonics in the pulse width modulation signal and output a DC voltage corresponding to the DC component in the pulse width modulation signal; The voltage value of the DC voltage is positively correlated with the duty cycle of the pulse width modulation signal; the voltage value of the gain control voltage output by the gain control module is correlated with the voltage value of the DC voltage; In response to the voltage value of the detection voltage being less than a preset voltage range, the timing controller increases 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; In response to the voltage value of the detection voltage being greater than a preset voltage range, the timing controller reduces 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 V based on the changed gain control voltage.

2. The display panel according to claim 1, wherein: The control voltage of the gain amplification unit is a negative voltage, and the gain control module further includes: A voltage inversion circuit is connected to the low-pass filter and the gain amplification module. The voltage inversion circuit is used to invert the DC voltage output by the low-pass filter and use it as the gain control voltage to output to the gain amplification unit.

3. The display panel according to claim 2, wherein: The low-pass filter is a second-order low-pass filter, and the low-pass filter includes a first resistor, a second resistor, a first capacitor and a second capacitor; wherein the first end of the first resistor is connected to the timing controller, the second end of the first resistor, the first end of the first capacitor and the first end of the second resistor are connected to a first node, the second end of the second resistor and the first end of the second capacitor are connected to a second node, the second node serves as the output end of the low-pass filter, and the second end of the first capacitor and the second end of the second capacitor are grounded.

4. The display panel according to claim 3, wherein: The voltage inversion circuit includes a voltage follower and an inverter; The voltage follower includes a first operational amplifier, a positive input terminal of the first operational amplifier is connected to the second node, the positive input terminal of the first operational amplifier is also connected to the output terminal of the first operational amplifier, and a negative input terminal of the first operational amplifier is grounded; The inverter includes a third resistor, a fourth resistor, a fifth resistor, and a second operational amplifier; wherein, the first end of the third resistor is connected to the output end of the first operational amplifier, the second end of the third resistor, the first end of the fourth resistor, and the negative input end of the second operational amplifier are connected to a third node, the second end of the fourth resistor is connected to the output end of the second operational amplifier, the output end of the second operational amplifier serves as the output end of the voltage inversion circuit, the positive input end of the second operational amplifier is connected to the first end of the fifth resistor, and the second end of the fifth resistor is grounded.

5. The display panel according to any one of claims 1 to 4, characterized in that: The voltage conversion unit includes a sixth resistor, a third capacitor, and a third operational amplifier; wherein the first end of the sixth resistor, the first end of the third capacitor, and the negative input terminal of the third operational amplifier are connected to a fourth node, and the fourth node is used to receive the light-sensing current; the second end of the sixth resistor, the second end of the third capacitor, and the output terminal of the third operational amplifier are connected to a fifth node, and the fifth node serves as the output terminal of the voltage conversion unit, and is used to output the light-sensing voltage; and the positive input terminal of the third operational amplifier is grounded; The gain amplification unit includes a first gain amplification unit, which includes a gain amplification chip and a seventh resistor. The non-inverting input terminal of the gain amplification chip is coupled to the fifth node, the control terminal of the gain amplification chip is connected to the output terminal of the gain control module for receiving the gain control voltage, the inverting input terminal of the gain amplification chip is connected to the first terminal of the seventh resistor, the second terminal of the seventh resistor is grounded, and the output terminal of the gain amplification chip is connected to the sampling module.

6. The display panel according to claim 5, wherein: The gain amplification unit includes a second gain amplification unit, which is connected between the voltage conversion unit and the first gain amplification unit; wherein the second gain amplification unit includes an eighth resistor, a ninth resistor, and a fourth operational amplifier, wherein the first end of the eighth resistor is connected to the fifth node, the second end of the eighth resistor, the first end of the ninth resistor, and the negative input end of the fourth operational amplifier are connected to the sixth node, the second end of the ninth resistor, the output end of the fourth operational amplifier, and the in-phase input end of the gain amplification chip are connected to the seventh node, and the positive input end of the fourth operational amplifier is grounded.

7. A method for automatically adjusting light-sensitive current, applied to the display panel according to any one of claims 1 to 6, characterized in that: include: Obtaining the detection voltage corresponding to the light-sensing current collected by the sampling module; In response to the voltage value of the detection voltage not being within a preset voltage range, outputting a gain control voltage to a gain amplification unit in a gain amplification module, so that the gain amplification unit adjusts the gain of the photosensitive voltage converted from the photosensitive current based on the gain control voltage; In response to a detection voltage corresponding to the light-sensing current acquired by the sampling module being within a preset voltage range, dimming is performed based on the detection voltage; Wherein, in response to the voltage value of the detection voltage not meeting the preset voltage range, the gain amplification unit in the gain amplification module outputs a gain control voltage, including: In response to the voltage value of the detection voltage being less than a 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; In response to the voltage value of the detection voltage being greater than a 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; Among them, also include: In each round of detection, after obtaining the detection voltage for the first time, the detection voltage corresponding to the light-sensing current collected by the sampling module is obtained again after a first preset delay time as a reference voltage; In response to the difference between the detection voltage and the reference voltage being greater than a preset threshold, it is determined to be a false trigger and the next round of sampling is entered.

Images