Display module power supply voltage sampling circuit and display substrate

Abstract

The embodiment of the invention provides a display module power supply voltage sampling circuit and a display substrate. The display module power supply voltage sampling circuit comprises a voltage sampling module and a voltage conversion module, the first end of the voltage sampling module is connected with the first negative voltage power supply and the reverse input signal end of the voltage conversion module. The second end of the voltage sampling module is connected with the power supply voltage end of the display module and the positive input signal end of the voltage conversion module. Wherein the first negative voltage power supply provides an initial negative voltage power supply for the display module; the voltage conversion module is used for acquiring a first negative voltage signal of the first negative voltage power supply through a reverse input signal end of the voltage conversion module, acquiring a second negative voltage signal of a power supply voltage end of the display module through a positive input signal end of the voltage conversion module, and comparing the first negative voltage signal with the second negative voltage signal; obtaining a digital quantity sampling result representing the power supply state of the display module; wherein the voltage value of the first negative voltage signal is smaller than that of the second negative voltage signal.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a display module power supply voltage sampling circuit and a display substrate. Background Art

[0002] With the continuous development of display modules, they are widely used in daily communications, industrial control, transportation, commercial displays and other fields. Whether it is for LCD (Liquid Crystal Display) modules, Micro-OLED (Micro-Organic Light-Emitting Diode) modules, OLED (Organic Light-Emitting Diode) modules, etc., the negative power supply voltage of the display module (the negative power supply voltage is an important power supply for driving the pixel circuit to emit light) needs to be considered during the design, production and inspection of the display module. During the display module inspection process, it is usually necessary to sample the negative power supply voltage of the display module and monitor the voltage and current states corresponding to the negative power supply voltage of the display module to ensure that the display module is operating in a normal performance state. However, because the voltage value of the negative power supply voltage is lower than the reference ground plane (GND), the current direction is opposite to that when the positive power supply voltage is supplied, resulting in the corresponding semiconductor circuit inside the voltage sampling unit (analog-to-digital converter) not being able to conduct normally (the voltage sampling input range of the currently available analog-to-digital converter is all positive and cannot be directly connected to negative voltage for sampling).

[0003] To address this issue, related art uses an operational amplifier and resistors to form an inverse proportional circuit to convert negative voltages into positive voltages to match the voltage sampling input range required by the analog-to-digital converter. However, due to system errors such as resistor production precision and operational amplifier drift, this sampling method for converting positive and negative voltages using an inverse proportional circuit suffers from significant errors and poor sampling accuracy. Summary of the Invention

[0004] The purpose of the embodiments of the present application is to provide a display module power supply voltage sampling circuit and a display substrate to improve the sampling accuracy of the display module power supply voltage. The specific technical solution is as follows:

[0005] In a first aspect, an embodiment of the present application provides a display module power supply voltage sampling circuit, the circuit comprising:

[0006] Voltage sampling module and voltage conversion module;

[0007] The first end of the voltage sampling module is connected to the first negative voltage power supply and the reverse input signal end of the voltage conversion module respectively, and the second end of the voltage sampling module is connected to the power supply voltage end of the display module and the positive input signal end of the voltage conversion module respectively; wherein, the first negative voltage power supply provides the initial negative voltage power supply for the display module;

[0008] The voltage conversion module is used to collect the first negative voltage signal of the first negative voltage power supply through its own reverse input signal end, collect the second negative voltage signal of the display module power supply voltage end through its own positive input signal end, compare the first negative voltage signal with the second negative voltage signal, and obtain a digital sampling result representing the power supply status of the display module; wherein the voltage value of the first negative voltage signal is less than the voltage value of the second negative voltage signal.

[0009] In a possible implementation, the circuit further includes a power supply module;

[0010] The positive voltage terminal of the power supply module is connected to the digital ground, the negative voltage terminal of the power supply module is connected to the second negative voltage power supply, the analog ground, and the ground terminal of the voltage conversion module respectively, and the output terminal of the power supply module is connected to the power voltage terminal of the voltage conversion module;

[0011] The power supply module is used to generate a third negative voltage signal between the zero voltage signal of the digital ground and the negative voltage signal of the second negative voltage power supply, and output the third negative voltage signal through its own output end to power the voltage conversion module.

[0012] In a possible implementation, the power module includes a voltage stabilizing submodule and a current limiting submodule;

[0013] The first end of the current limiting submodule is connected to the digital ground, and the second end of the current limiting submodule is connected to the first end of the voltage stabilizing submodule and the power supply voltage end of the voltage conversion module respectively;

[0014] The second end of the voltage stabilizing submodule is respectively connected to the second negative voltage power supply, the analog ground, and the ground end of the voltage conversion module;

[0015] The voltage stabilizing submodule is configured to enter a saturated conduction operating state when the voltage drop between the first and second terminals of the voltage stabilizing submodule is greater than the saturated conduction voltage of the voltage stabilizing submodule, and stabilize the voltage signal of the first terminal of the voltage stabilizing submodule at the third negative voltage signal;

[0016] The current limiting submodule is used to control the third negative voltage signal by controlling the current signal flowing through the voltage stabilizing submodule when the voltage stabilizing submodule is in a saturated conduction working state.

[0017] In one possible embodiment, the voltage conversion module is specifically used to collect the first negative voltage signal through its own reverse input signal end, collect the second negative voltage signal through its own positive input signal end, compare the first negative voltage signal with the second negative voltage signal, obtain the current signal of the power supply voltage end of the display module, and convert the first negative voltage signal / second negative voltage signal and the current signal into digital sampling results.

[0018] In a possible implementation, the voltage sampling module includes a sampling resistor;

[0019] The first pin of the sampling resistor is connected to the first negative voltage power supply and the reverse input signal terminal of the voltage conversion module respectively, and the second pin of the sampling resistor is connected to the power supply voltage terminal of the display module and the forward input signal terminal of the voltage conversion module respectively.

[0020] In one possible implementation, the voltage conversion module includes an analog-to-digital converter;

[0021] The reverse input signal pin of the analog-to-digital converter is respectively connected to the first negative voltage power supply and the first end of the voltage sampling module, and the positive input signal pin of the analog-to-digital converter is respectively connected to the second end of the voltage sampling module and the power supply voltage end of the display module.

[0022] In a possible implementation, the voltage stabilizing submodule includes a voltage stabilizing diode, and the current limiting submodule includes a current limiting resistor;

[0023] The first pin of the current limiting resistor is connected to the digital ground, and the second pin of the current limiting resistor is connected to the cathode pin of the voltage stabilizing diode and the power supply voltage terminal of the voltage conversion module respectively;

[0024] The positive electrode pin of the voltage stabilizing diode is respectively connected to the second negative voltage power supply, the analog ground, and the ground terminal of the voltage conversion module.

[0025] In a second aspect, an embodiment of the present application provides a display substrate, which includes a display module and the display module power supply voltage sampling circuit described in any one of the first aspects above.

[0026] In a possible implementation, the display substrate further includes a signal processing circuit, and the signal processing circuit includes an isolation module and a processing module;

[0027] The input signal terminal of the isolation module is connected to the output signal terminal of the voltage conversion module, and the output signal terminal of the isolation module is connected to the input signal terminal of the processing module;

[0028] The first power supply voltage terminal of the isolation module is connected to the power supply voltage terminal of the voltage conversion module, the first ground terminal of the isolation module is connected to the ground terminal of the voltage conversion module, the second power supply voltage terminal of the isolation module is respectively connected to the positive voltage power supply and the power supply voltage terminal of the processing module, and the second ground terminal of the isolation module is respectively connected to the digital ground and the ground terminal of the processing module;

[0029] The isolation module is configured to receive the digital quantity sampling result output by the voltage conversion module and report the digital quantity sampling result to the processing module;

[0030] The processing module is configured to receive the digital quantity sampling result reported by the isolation module, compare the digital quantity sampling result with a preset range, and issue an alarm signal if the digital quantity sampling result deviates from the preset range.

[0031] In one possible implementation, the isolation module includes a bidirectional I2C isolator, and the processing module includes a main processor;

[0032] The input signal pin of the bidirectional I2C isolator is connected to the output signal end of the voltage conversion module, and the output signal pin of the bidirectional I2C isolator is connected to the input signal pin of the main processor;

[0033] The first power supply voltage pin of the bidirectional I2C isolator is connected to the power supply voltage end of the voltage conversion module, the first ground pin of the bidirectional I2C isolator is connected to the ground end of the voltage conversion module, the second power supply voltage pin of the bidirectional I2C isolator is respectively connected to the positive voltage power supply and the power supply voltage pin of the main processor, and the second ground pin of the bidirectional I2C isolator is respectively connected to the digital ground and the ground pin of the main processor.

[0034] Beneficial effects of the embodiments of the present application:

[0035] An embodiment of the present application provides a display module power supply voltage sampling circuit and a display substrate, wherein the display module power supply voltage sampling circuit includes: a voltage sampling module and a voltage conversion module; the first end of the voltage sampling module is respectively connected to the first negative voltage power supply and the reverse input signal end of the voltage conversion module, and the second end of the voltage sampling module is respectively connected to the power supply voltage end of the display module and the positive input signal end of the voltage conversion module; wherein the first negative voltage power supply provides an initial negative voltage power supply for the display module; the voltage conversion module is used to collect a first negative voltage signal of the first negative voltage power supply through its own reverse input signal end, collect a second negative voltage signal of the power supply voltage end of the display module through its own positive input signal end, compare the first negative voltage signal with the second negative voltage signal, and obtain a digital sampling result representing the power supply status of the display module; wherein the voltage value of the first negative voltage signal is less than the voltage value of the second negative voltage signal. By combining the first negative voltage power supply with the voltage sampling module, a first negative voltage signal and a second negative voltage signal are generated. The reverse input signal end of the voltage conversion module collects the first negative voltage signal, and the positive input signal end collects the second negative voltage signal. The voltage value of the first negative voltage signal is less than the voltage value of the second negative voltage signal, so that the input signal polarity of the voltage conversion module (the voltage difference between the positive input signal end and the negative input signal end) is positive, thereby realizing input matching between the voltage conversion module and the negative voltage signal sampling. Compared with the related technology of "using an operational amplifier and a resistor to form a reverse proportional circuit to convert the negative voltage into a positive voltage to match the voltage sampling input range required by the analog-to-digital converter", the introduction of system errors is reduced and the sampling accuracy of the display module power supply voltage is improved.

[0036] Of course, it is not necessary to achieve all the advantages described above at the same time when implementing any product or method of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other embodiments can also be obtained based on these drawings.

[0038] Figure 1 A schematic diagram of a first structure of a display module power supply voltage sampling circuit provided in an embodiment of the present application;

[0039] Figure 2 A second structural diagram of the display module power supply voltage sampling circuit provided in an embodiment of the present application;

[0040] Figure 3 A third structural diagram of the display module power supply voltage sampling circuit provided in an embodiment of the present application;

[0041] Figure 4 A fourth structural diagram of the display module power supply voltage sampling circuit provided in an embodiment of the present application;

[0042] Figure 5 A schematic diagram of the first structure of a display substrate provided in an embodiment of the present application;

[0043] Figure 6 A schematic diagram of a second structure of a display substrate provided in an embodiment of the present application;

[0044] Figure 7 This is a schematic diagram of the third structure of the display substrate provided in an embodiment of the present application. DETAILED DESCRIPTION

[0045] 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 based on this application are within the scope of protection of this application.

[0046] With the continuous development of display modules, they are widely used in daily communications, industrial control, transportation, commercial displays and other fields. Whether it is for LCD (Liquid Crystal Display) modules, Micro-OLED (Micro-Organic Light-Emitting Diode) modules, OLED (Organic Light-Emitting Diode) modules, etc., the negative power supply voltage of the display module (the negative power supply voltage is an important power supply for driving the pixel circuit to emit light) needs to be considered during the design, production and inspection of the display module. During the display module inspection process, it is usually necessary to sample the negative power supply voltage of the display module and monitor the voltage and current states corresponding to the negative power supply voltage of the display module to ensure that the display module is operating in a normal performance state. However, because the voltage value of the negative power supply voltage is lower than the reference ground plane (GND), the current direction is opposite to that when the positive power supply voltage is supplied, resulting in the corresponding semiconductor circuit inside the voltage sampling unit (analog-to-digital converter) not being able to conduct normally (the voltage sampling input range of the currently available analog-to-digital converter is all positive and cannot be directly connected to negative voltage for sampling).

[0047] To address the aforementioned issues, related art techniques utilize a combination of an operational amplifier and a resistor to form an inverse proportional circuit that converts negative voltages into positive voltages to match the voltage sampling input range required by the analog-to-digital converter. However, due to system errors such as resistor production precision and operational amplifier drift, the sampling method for converting positive and negative voltages using an inverse proportional circuit in related art suffers from significant errors. Even with a more precise analog-to-digital converter, it is difficult to improve overall sampling accuracy. The greater the sampling error, the lower the sampling accuracy, and the further the sampled data reported to the main processor deviates from the actual power supply status of the display module. The main processor is unable to obtain accurate sampled data and may make erroneous judgments and processing based on sampled data that deviates significantly from the actual power supply status, resulting in poor reliability in monitoring the power supply status of the display module.

[0048] In order to improve at least one of the above problems, an embodiment of the present application provides a display module power supply voltage sampling circuit and a display substrate.

[0049] Next, the display module power supply voltage sampling circuit 1 provided in the embodiment of the present application is described in detail. Figure 1 , is a first structural diagram of a display module power supply voltage sampling circuit 1 provided in an embodiment of the present application, wherein the display module power supply voltage sampling circuit 1 includes:

[0050] Voltage sampling module 11 and voltage conversion module 12;

[0051] The first end of the voltage sampling module 11 is connected to the first negative voltage power supply Vneg' and the reverse input signal end of the voltage conversion module 12, respectively. The second end of the voltage sampling module 11 is connected to the power supply voltage end of the display module and the positive input signal end of the voltage conversion module 12, respectively. The first negative voltage power supply Vneg' provides a starting negative voltage power supply for the display module.

[0052] The voltage conversion module 12 is used to collect the first negative voltage signal Vneg of the first negative voltage power supply Vneg' through its own reverse input signal terminal, collect the second negative voltage signal Vp of the display module power supply voltage terminal through its own positive input signal terminal, compare the first negative voltage signal Vneg with the second negative voltage signal Vp, and obtain a digital sampling result representing the power supply status of the display module; wherein the voltage value of the first negative voltage signal Vneg is less than the voltage value of the second negative voltage signal Vp.

[0053] The voltage sampling module 11 can be a sampling resistor. When the display module is in an operating state, the first negative voltage power supply Vneg' will provide the required current to the display module, and the current will flow through the sampling resistor. According to Ohm's law, the current flowing through the sampling resistor will generate a voltage difference (voltage drop). At this time, the voltages across the sampling resistor are respectively a first negative voltage signal Vneg and a second negative voltage signal Vp (the first end of the sampling resistor is connected to the first negative voltage power supply Vneg', and the second end of the sampling resistor is connected to the power supply voltage end of the display module). The first negative voltage signal Vneg and the second negative voltage signal Vp are the negative power supply voltages of the display module that need to be sampled in this application.

[0054] The voltage conversion module 12 can be an analog-to-digital converter (ADC), which receives negative voltage signals (a first negative voltage signal Vneg and a second negative voltage signal Vp) from both ends of the sampling resistor. Since Vp>Vneg (the absolute value of Vneg is greater than the absolute value of Vp, and the larger the absolute value, the smaller the voltage value), the node corresponding to the second negative voltage signal Vp is connected to the positive input signal end of the analog-to-digital converter, and the node corresponding to the first negative voltage signal Vneg is connected to the negative input signal end of the analog-to-digital converter. The voltage difference between the positive input signal end and the negative input signal end is a positive value, that is, the input signal polarity of the analog-to-digital converter is positive, thereby achieving input matching between the analog-to-digital converter and the negative voltage signal sampling.

[0055] The analog-to-digital converter collects and compares these two negative voltage signals to calculate the current signal at the display module power supply voltage terminal (the voltage difference between the positive and negative input signal terminals of the analog-to-digital converter is the voltage drop across the sampling resistor; the voltage drop across the sampling resistor divided by the resistance of the sampling resistor equals the current signal at the display module power supply voltage terminal). Either the first negative voltage signal Vneg or the second negative voltage signal Vp, as well as the current signal, are converted into digital signals to obtain a digital sampling result. It should be noted that the resistance of the sampling resistor is relatively small, and the voltage values of the first negative voltage signal Vneg and the second negative voltage signal Vp are relatively close. Therefore, the first negative voltage signal Vneg, the second negative voltage signal Vp, and the aforementioned current signals are all analog signals.

[0056] The analog-to-digital converter can also calculate the power consumption value corresponding to the negative power supply voltage of the display module based on any one of the first negative voltage signal Vneg and the second negative voltage signal Vp and the above-mentioned current signal, convert the power consumption value into a digital signal, and use it together with the digital signal after the negative voltage signal is converted and the digital signal after the current signal is converted as the digital quantity sampling result.

[0057] The main processor and the bidirectional I2C isolator in the display substrate 2 receive the digital quantity sampling results output by the voltage conversion module 12, and compare the digital quantity sampling results with the preset range. When the digital quantity sampling results deviate from the preset range, an alarm signal is issued (indicating that the display module is in an abnormal power supply state). When the digital quantity sampling results are within the preset range (indicating that the display module is in a normal power supply state), no indication indicating that the display module is in an abnormal power supply state is issued, so as to monitor the power supply state of the display module; wherein the preset range is the power supply parameter range corresponding to when the display module is in a normal power supply state. In one example, the normal ranges of various parameters are usually pre-set inside the main processor. For example, the normal value of the negative power supply voltage of the display module is -8V±0.4V, and the corresponding normal value of the operating current is 5mA-15mA. When the digital signal after the negative voltage signal is converted deviates from the range of -8V±0.4V, or the digital signal after the current signal is converted deviates from the range of 5mA-15mA, the error type is reported through screen display, activation of indicator lights, activation of buzzers, etc., to remind inspection personnel to intercept the defective display module, troubleshoot or replace it with a good product.

[0058] In an embodiment of the present application, a first negative voltage power supply Vneg' is combined with a voltage sampling module 11 to generate a first negative voltage signal Vneg and a second negative voltage signal Vp. The reverse input signal terminal of the voltage conversion module 12 collects the first negative voltage signal Vneg, and the positive input signal terminal collects the second negative voltage signal Vp. The voltage value of the first negative voltage signal Vneg is less than the voltage value of the second negative voltage signal Vp, so that the input signal polarity of the voltage conversion module 12 (the voltage difference between the positive input signal terminal and the negative input signal terminal) is positive, thereby achieving input matching between the voltage conversion module 12 and the negative voltage signal sampling. Compared with the related art of "using an operational amplifier and a resistor to form an inverse proportional circuit to convert a negative voltage into a positive voltage to match the voltage sampling input range required by the analog-to-digital converter", the introduction of system errors is reduced, the sampling accuracy of the display module power supply voltage is improved, and the reliability of the display module power supply status monitoring can be improved.

[0059] In one possible implementation, see Figure 2 , the circuit 1 further includes a power supply module 13;

[0060] The positive voltage terminal of the power supply module 13 is connected to the digital ground DGND (the digital ground DGND is the common reference point of the power supply voltage sampling circuit system and is defined as the system reference 0V), the negative voltage terminal of the power supply module 13 is respectively connected to the second negative voltage supply source Vn', the analog ground AGND (the analog ground AGND is the reference reference point of the voltage conversion module 12 and the power supply module 13), and the ground terminal of the voltage conversion module 12, and the output terminal of the power supply module 13 is connected to the power supply voltage terminal of the voltage conversion module 12;

[0061] The power supply module 13 is used to generate a third negative voltage signal V between the zero voltage signal of the digital ground DGND and the negative voltage signal of the second negative voltage supply source Vn'. A and outputs the third negative voltage signal V through its own output terminal A , to supply power to the voltage conversion module 12.

[0062] Since the supply voltage of the voltage conversion module 12 needs to be the same as the signal polarity of its own positive input signal terminal and negative input signal terminal, the power supply module 13 generates a third negative voltage signal V with the same polarity as the first negative voltage signal Vneg and the second negative voltage signal Vp. A , to supply power to the voltage conversion module 12. Wherein, Vn<V A <VDGND=0V, Vn is the negative voltage signal of the second negative voltage power supply Vn', and VDGND is the voltage signal of the digital ground DGND.

[0063] The second negative voltage supply source Vn' is connected to the analog ground AGND, so Vn=VAGND, where VAGND is the voltage signal of the analog ground AGND. A <VDGND=0V, then VAGND<V A <0V.

[0064] In summary, the voltage signal of the ground terminal of the voltage conversion module 12 is VAGND (the ground terminal of the voltage conversion module 12 is connected to the analog ground AGND), and the voltage signal of the power supply voltage terminal of the voltage conversion module 12 is V A (The power supply voltage terminal of the voltage conversion module 12 is connected to the output terminal of the power supply module 13), the voltage difference between the power supply voltage terminal and the ground terminal of the voltage conversion module 12 (V A -VAGND) is a positive value.

[0065] In the embodiment of the present application, by considering the second negative voltage supply source Vn' (analog ground AGND) as the ground and the digital ground DGND as the positive voltage source, a third negative voltage signal V is generated with the same polarity as the first negative voltage signal Vneg and the second negative voltage signal Vp. A, supplies power to the voltage conversion module 12, and the voltage difference between the power supply voltage terminal and the ground terminal of the voltage conversion module 12 (V A -VAGND) is a positive value, ensuring the normal operation of the voltage conversion module 12 (when the voltage difference between the power voltage terminal and the ground terminal of the voltage conversion module 12 is a negative value, the voltage conversion module 12 cannot work normally).

[0066] In one possible implementation, see Figure 3 , the power supply module 13 includes a voltage stabilizing submodule 131 and a current limiting submodule 132;

[0067] The first end of the current limiting submodule 132 is connected to the digital ground DGND, and the second end of the current limiting submodule 132 is connected to the first end of the voltage stabilizing submodule 131 and the power supply voltage end of the voltage conversion module 12 respectively;

[0068] The second end of the voltage stabilizing submodule 131 is respectively connected to the second negative voltage power supply Vn', the analog ground AGND, and the ground end of the voltage conversion module 12;

[0069] The voltage stabilizing submodule 131 is used to enter the saturation conduction working state when the voltage drop between the first end and the second end is greater than the saturation conduction voltage of the voltage stabilizing submodule 131, and stabilize the voltage signal of the first end at the third negative voltage signal V A ;

[0070] The current limiting submodule 132 is used to control the current signal flowing through the voltage stabilizing submodule 131 when the voltage stabilizing submodule 131 is in a saturated conduction working state, so as to achieve the third negative voltage signal V A control.

[0071] The voltage stabilizing submodule 131 can be a voltage stabilizing diode. A voltage stabilizing diode is connected between the digital ground DGND and the second negative voltage power supply Vn' (Vn<VDGND=0V). When the voltage difference across the voltage stabilizing diode is greater than its saturation conduction voltage, the voltage stabilizing diode enters a saturation conduction working state, stabilizing the voltage across the two ends at a substantially fixed value.

[0072] The current limiting submodule 132 can be a current limiting resistor. According to the saturation conduction characteristics of the voltage-regulating diode, the clamping voltage at both ends of the voltage-regulating diode is related to the current flowing through it when it is saturated and turned on. Therefore, a current limiting resistor (voltage divider resistor) is connected in series in the circuit corresponding to the voltage-regulating diode. By adjusting the resistance value of the current limiting resistor, the current flowing through the voltage-regulating diode when it is saturated and turned on is controlled to achieve the output voltage (the third negative voltage signal V A) is controlled to meet the power supply specification requirements of the load (voltage conversion module 12) and ensure that the voltage across the Zener diode is within the normal operating voltage range of the voltage conversion module 12.

[0073] In the embodiment of the present application, by setting the current limiting submodule 132 and the voltage stabilizing submodule 131, a third negative voltage signal V with the same polarity as the first negative voltage signal Vneg and the second negative voltage signal Vp is generated between Vn and VDGND. A , to supply power to the voltage conversion module 12.

[0074] In one possible embodiment, the voltage conversion module 12 is specifically used to collect the first negative voltage signal Vneg through its own reverse input signal end, collect the second negative voltage signal Vp through its own positive input signal end, compare the first negative voltage signal Vneg with the second negative voltage signal Vp, obtain the current signal of the power supply voltage end of the display module, and convert the first negative voltage signal Vneg / the second negative voltage signal Vp and the current signal into digital sampling results, and transmit the digital sampling results to the isolation module 31 of the display substrate 2.

[0075] The specific analysis is the same as above and will not be repeated here.

[0076] In one possible implementation, see Figure 4 , the voltage sampling module 11 includes a sampling resistor Radc;

[0077] The first pin of the sampling resistor Radc is connected to the first negative voltage power supply Vneg' and the reverse input signal terminal of the voltage conversion module 12 respectively, and the second pin of the sampling resistor Radc is connected to the power supply voltage terminal of the display module and the forward input signal terminal of the voltage conversion module 12 respectively.

[0078] When the display module is in operation, the first negative voltage power supply Vneg' provides the required current to the display module. This current flows through the sampling resistor Radc. According to Ohm's law, the current flowing through the sampling resistor Radc generates a voltage difference (voltage drop). At this time, the voltages at the two pins of the sampling resistor Radc are the first negative voltage signal Vneg and the second negative voltage signal Vp, respectively (the first pin of the sampling resistor Radc is connected to the first negative voltage power supply Vneg', and the second pin of the sampling resistor Radc is connected to the power supply voltage terminal of the display module). The first negative voltage signal Vneg and the second negative voltage signal Vp are the negative power supply voltage of the display module that needs to be sampled in this application.

[0079] In an example, the accuracy of the sampling resistor Radc may be 5%.

[0080] In one possible implementation, see Figure 4 and Figure 6 , the voltage conversion module 12 includes an analog-to-digital converter ADC;

[0081] The reverse input signal pin IN- of the analog-to-digital converter ADC is respectively connected to the first negative voltage power supply Vneg' and the first end of the voltage sampling module 11, the positive input signal pin IN+ of the analog-to-digital converter ADC is respectively connected to the second end of the voltage sampling module 11 and the power supply voltage end of the display module, and the output signal I2C pin of the analog-to-digital converter ADC is connected to the input signal end of the isolation module 31.

[0082] The power supply voltage pin VCC of the analog-to-digital converter ADC is respectively connected to the second pin of the current limiting resistor Rlim and the cathode pin of the voltage stabilizing diode Dw, and the ground pin GND of the analog-to-digital converter ADC is respectively connected to the anode pin of the voltage stabilizing diode Dw, the second negative voltage supply Vn', and the analog ground AGND.

[0083] The analog-to-digital converter ADC collects the first negative voltage signal Vneg through its own reverse input signal pin IN-, and collects the second negative voltage signal Vp through its own positive input signal pin IN+. Vp>Vneg, and the voltage difference (Vp-Vneg) between the positive input signal pin IN+ and the negative input signal pin IN- is a positive value, that is, the input signal polarity of the analog-to-digital converter ADC is positive, thereby realizing input matching between the analog-to-digital converter ADC and the negative voltage signal sampling.

[0084] The core logic of differential input is the voltage difference between the positive input signal pin IN+ and the negative input signal pin IN-, without directly paying attention to the voltage polarity of a single pin. This means that the polarity of the input signal is determined by the voltage difference, and the analog-to-digital converter ADC will regard the voltage difference as a valid positive input signal.

[0085] In one possible implementation, see Figure 4 , the voltage stabilizing submodule 131 includes a voltage stabilizing diode Dw, and the current limiting submodule 132 includes a current limiting resistor Rlim;

[0086] The first pin of the current limiting resistor Rlim is connected to the digital ground DGND, and the second pin of the current limiting resistor Rlim is connected to the cathode pin of the voltage stabilizing diode Dw and the power supply voltage terminal of the voltage conversion module 12 respectively;

[0087] The anode pin of the voltage stabilizing diode Dw is connected to the second negative voltage power source Vn′, the analog ground AGND, and the ground terminal of the voltage conversion module 12 respectively.

[0088] A Zener diode Dw is connected between the digital ground DGND and the second negative voltage power supply Vn' (Vn<VDGND=0V). When the voltage difference between the two pins of the Zener diode Dw is greater than its saturation conduction voltage, the Zener diode Dw enters the saturation conduction working state, stabilizing the voltage between the two pins at a basically fixed value.

[0089] According to the saturation conduction characteristics of the Zener diode Dw, the clamping voltage of the Zener diode Dw is related to the current flowing through it when it is saturated and turned on. Therefore, a current limiting resistor Rlim (voltage dividing resistor) is connected in series in the circuit corresponding to the Zener diode Dw. By adjusting the resistance value of the current limiting resistor Rlim, the current flowing through the Zener diode Dw when it is saturated and turned on is controlled to achieve the output voltage (the third negative voltage signal V A ) is controlled to meet the power supply specification requirements of the analog-to-digital converter ADC and ensure that the voltage of the two pins of the voltage regulator diode Dw is within the normal operating voltage range of the analog-to-digital converter ADC.

[0090] In the embodiment of the present application, by setting the current limiting resistor Rlim and the voltage stabilizing diode Dw, a third negative voltage signal V with the same polarity as the first negative voltage signal Vneg and the second negative voltage signal Vp is generated between Vn and VDGND. A , to power the analog-to-digital converter ADC.

[0091] The present application also provides a display substrate 2, see Figure 5 The display substrate 2 includes a display module 21 and the display module power supply voltage sampling circuit 1 described in any one of the above embodiments.

[0092] In one possible implementation, see Figure 6 , the display substrate 2 further includes a signal processing circuit 3, and the signal processing circuit 3 includes an isolation module 31 and a processing module 32;

[0093] The input signal terminal of the isolation module 31 is connected to the output signal terminal of the voltage conversion module 12, and the output signal terminal of the isolation module 31 is connected to the input signal terminal of the processing module 32;

[0094] The first power supply voltage terminal of the isolation module 31 is connected to the power supply voltage terminal of the voltage conversion module 12, the first ground terminal of the isolation module 31 is connected to the ground terminal of the voltage conversion module 12, and the second power supply voltage terminal of the isolation module 31 is connected to the positive voltage supply V D ', the power supply voltage terminal of the processing module 32 is connected, and the second ground terminal of the isolation module 31 is connected to the digital ground DGND and the ground terminal of the processing module 32 respectively;

[0095] The isolation module 31 is configured to receive the digital quantity sampling result output by the voltage conversion module 12 and report the digital quantity sampling result to the processing module 32;

[0096] The processing module 32 is used to receive the digital quantity sampling result reported by the isolation module 31, compare the digital quantity sampling result with a preset range, and when the digital quantity sampling result deviates from the preset range, issue an indication indicating that the display module is in an abnormal power supply state; when the digital quantity sampling result is within the preset range (indicating that the display module is in a normal power supply state), do not issue an indication indicating that the display module is in an abnormal power supply state, so as to monitor the power supply status of the display module.

[0097] In the present application, the signal processing circuit 3 is a circuit unit that performs signal processing on the digital quantity sampling results, and is used to receive the digital quantity sampling results output by the voltage conversion module 12, compare the digital quantity sampling results with a preset range, and issue an alarm signal when the digital quantity sampling results deviate from the preset range. The signal processing circuit 3 may include a processor, or may include a processor and a functional circuit adapted therefor. In one example, the signal processing circuit 3 includes a processing module 32. In another example, the signal processing circuit includes a processing module 32 and an isolation module 31.

[0098] The isolation module 31 is connected to the power supply for supplying power to the voltage conversion module 12 and the power supply for supplying power to the processing module 32 (the power supply module 13 supplies power to the isolation module 31 and the voltage conversion module 12, and the positive voltage power supply V D 'Powering the isolation module 31 and the processing module 32) enables data transmission between modules with different power supplies, that is, communication between the voltage conversion module 12 and the processing module 32. Furthermore, the isolation module 31 can improve the reliability and anti-interference performance of the signal transmission process. Specifically, the isolation module 31, through its internal circuit design, can achieve logic level adaptation between different voltage domains and automatically match the level thresholds of different power supply modules to avoid communication anomalies caused by level incompatibility. Furthermore, the isolation module 31 can ensure electrical isolation and improve the anti-interference performance and integrity of signal transmission.

[0099] Normal ranges for various parameters are usually pre-set inside the processing module 32. For example, the normal value of the negative power supply voltage of the display module is -8V±0.4V, and the corresponding normal value of the operating current is 5mA-15mA. When the voltage state in the digital sampling result deviates from the range of -8V±0.4V, or the current state in the digital sampling result deviates from the range of 5mA-15mA, the processing module 32 will report the error type through screen display, activation of indicator lights, activation of buzzers, etc., to remind the inspection personnel to intercept the defective display module, troubleshoot or replace it with a good product.

[0100] In the embodiment of the present application, the power supply for supplying power to the voltage conversion module 12 and the power supply for supplying power to the processing module 32 are connected through the isolation module 31 (the power supply module 13 supplies power to the isolation module 31 and the voltage conversion module 12, and the positive voltage power supply V D 'Powering the isolation module 31 and the processing module 32) to achieve data transmission between modules with different power supplies, that is, to achieve communication between the voltage conversion module 12 and the processing module 32, and the isolation module 31 can also improve the reliability and anti-interference of the signal transmission process.

[0101] In one possible implementation, see Figure 7 , the isolation module 31 includes a bidirectional I2C isolator, and the processing module 32 includes a main processor;

[0102] The input signal pin I2C1 of the bidirectional I2C isolator is connected to the output signal end of the voltage conversion module 12, and the output signal pin I2C2 of the bidirectional I2C isolator is connected to the input signal pin I2C3 of the main processor;

[0103] The first power supply voltage pin VCC1 of the bidirectional I2C isolator is connected to the power supply voltage terminal of the voltage conversion module 12 (the first power supply voltage pin VCC1 of the bidirectional I2C isolator and the power supply voltage terminal of the voltage conversion module 12 are both the third negative voltage signal V A ), the first ground pin GND1 of the bidirectional I2C isolator is connected to the ground terminal (analog ground AGND) of the voltage conversion module 12, and the second power supply voltage pin VCC2 of the bidirectional I2C isolator is respectively connected to the positive voltage supply V D ', the power supply voltage pin VCC3 of the main processor, the second ground pin GND2 of the bidirectional I2C isolator is connected to the digital ground DGND and the ground pin GND3 of the main processor respectively.

[0104] The bidirectional I2C isolator is connected to the power supply for the analog-to-digital converter ADC and the power supply for the main processor (the power supply module 13 composed of the current limiting resistor Rlim and the voltage regulator diode Dw is used to power the bidirectional I2C isolator and the analog-to-digital converter ADC, and the positive voltage supply V D 'Powering the bidirectional I2C isolator and the main processor) enables data transmission between modules with different power supplies, that is, communication between the analog-to-digital converter ADC and the main processor. The bidirectional I2C isolator can also improve the reliability and anti-interference of the signal transmission process.

[0105] A bidirectional I2C isolator is a device that can achieve electrical isolation in I2C communication (Inter-Integrated Circuit). It can transmit data on both sides of the I2C bus, that is, transmit digital sampled data, ensuring data integrity and system stability.

[0106] Normal ranges for various parameters are usually pre-set inside the main processor. For example, the normal value of the negative power supply voltage of the display module is -8V±0.4V, and the corresponding normal value of the operating current is 5mA-15mA. When the voltage state in the digital sampling result deviates from the range of -8V±0.4V, or the current state in the digital sampling result deviates from the range of 5mA-15mA, the main processor will report the error type through screen display, activation of indicator lights, activation of buzzers, etc., to remind inspection personnel to intercept the defective display module, troubleshoot or replace it with a good product.

[0107] In the embodiment of the present application, the power supply for powering the analog-to-digital converter ADC and the power supply for powering the main processor are connected respectively through the bidirectional I2C isolator (the power supply module 13 composed of the current limiting resistor Rlim and the voltage regulator diode Dw is used to power the bidirectional I2C isolator and the analog-to-digital converter ADC, and the positive voltage supply V D 'Powering the bidirectional I2C isolator and the main processor) enables data transmission between modules with different power supplies, that is, communication between the analog-to-digital converter ADC and the main processor. The bidirectional I2C isolator can also improve the reliability and anti-interference of the signal transmission process.

[0108] This application achieves input matching between the analog-to-digital converter (ADC) and the negative voltage signal sampling through negative voltage isolation sampling (Vn' is the power supply for the negative voltage sampling isolation area, and DGND is the digital ground for the negative voltage sampling isolation area), isolated transmission of sampling results, and reverse conduction power supply by a voltage regulator diode. Compared with the related art of "using an operational amplifier and a resistor to form an inverse proportional circuit to convert the negative voltage into a positive voltage to match the voltage sampling input range required by the analog-to-digital converter", the introduction of system errors is reduced, the sampling accuracy is improved, and the reliability of the display module power supply status monitoring is improved. The sampling scheme of this application can achieve voltage and current sampling with an accuracy of 0.01V and 0.5mA, which can effectively meet the low current and high precision sampling requirements of the display module. While improving the accuracy, it effectively reduces the cost of the sampling circuit solution (no additional circuit is required for voltage conversion, and high-precision sampling can be achieved even with a lower-precision analog-to-digital converter. The lower the accuracy of the analog-to-digital converter, the lower the cost).

[0109] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0110] Each embodiment in this specification is described in a related manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiment is generally similar to the method embodiment, so the description is relatively simple. For related parts, refer to the description of the method embodiment.

[0111] The above description is only a preferred embodiment of the present application and is not intended to limit the scope of protection of the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application are included in the scope of protection of the present application.

Claims

1. A display module power supply voltage sampling circuit, characterized in that: The circuit comprises: Voltage sampling module and voltage conversion module; The first end of the voltage sampling module is connected to the first negative voltage power supply and the reverse input signal end of the voltage conversion module respectively, and the second end of the voltage sampling module is connected to the power supply voltage end of the display module and the positive input signal end of the voltage conversion module respectively; wherein, the first negative voltage power supply provides the initial negative voltage power supply for the display module; The voltage conversion module is used to collect the first negative voltage signal of the first negative voltage power supply through its own reverse input signal end, collect the second negative voltage signal of the display module power supply voltage end through its own positive input signal end, compare the first negative voltage signal with the second negative voltage signal, and obtain a digital sampling result representing the power supply status of the display module; wherein the voltage value of the first negative voltage signal is less than the voltage value of the second negative voltage signal.

2. The circuit according to claim 1, wherein: The circuit further includes a power supply module; The positive voltage terminal of the power supply module is connected to the digital ground, the negative voltage terminal of the power supply module is connected to the second negative voltage power supply, the analog ground, and the ground terminal of the voltage conversion module respectively, and the output terminal of the power supply module is connected to the power voltage terminal of the voltage conversion module; The power supply module is used to generate a third negative voltage signal between the zero voltage signal of the digital ground and the negative voltage signal of the second negative voltage power supply, and output the third negative voltage signal through its own output end to power the voltage conversion module.

3. The circuit according to claim 2, characterized in that The power supply module includes a voltage stabilizing submodule and a current limiting submodule; The first end of the current limiting submodule is connected to the digital ground, and the second end of the current limiting submodule is connected to the first end of the voltage stabilizing submodule and the power supply voltage end of the voltage conversion module respectively; The second end of the voltage stabilizing submodule is respectively connected to the second negative voltage power supply, the analog ground, and the ground end of the voltage conversion module; The voltage stabilizing submodule is configured to enter a saturated conduction operating state when the voltage drop between the first and second terminals of the voltage stabilizing submodule is greater than the saturated conduction voltage of the voltage stabilizing submodule, and stabilize the voltage signal of the first terminal of the voltage stabilizing submodule at the third negative voltage signal; The current limiting submodule is used to control the third negative voltage signal by controlling the current signal flowing through the voltage stabilizing submodule when the voltage stabilizing submodule is in a saturated conduction working state.

4. The circuit according to claim 1, wherein: The voltage conversion module is specifically used to collect the first negative voltage signal through its own reverse input signal end, collect the second negative voltage signal through its own positive input signal end, compare the first negative voltage signal with the second negative voltage signal, obtain the current signal of the power supply voltage end of the display module, and convert the first negative voltage signal / second negative voltage signal and the current signal into digital sampling results.

5. The circuit according to claim 1, wherein: The voltage sampling module includes a sampling resistor; The first pin of the sampling resistor is connected to the first negative voltage power supply and the reverse input signal terminal of the voltage conversion module respectively, and the second pin of the sampling resistor is connected to the power supply voltage terminal of the display module and the forward input signal terminal of the voltage conversion module respectively.

6. The circuit according to claim 1, wherein: The voltage conversion module includes an analog-to-digital converter; The reverse input signal pin of the analog-to-digital converter is respectively connected to the first negative voltage power supply and the first end of the voltage sampling module, and the positive input signal pin of the analog-to-digital converter is respectively connected to the second end of the voltage sampling module and the power supply voltage end of the display module.

7. The circuit according to claim 3, characterized in that The voltage stabilizing submodule includes a voltage stabilizing diode, and the current limiting submodule includes a current limiting resistor; The first pin of the current limiting resistor is connected to the digital ground, and the second pin of the current limiting resistor is connected to the cathode pin of the voltage stabilizing diode and the power supply voltage terminal of the voltage conversion module respectively; The positive electrode pin of the voltage stabilizing diode is respectively connected to the second negative voltage power supply, the analog ground, and the ground terminal of the voltage conversion module.

8. A display substrate, characterized in that: The display substrate includes a display module and the display module power supply voltage sampling circuit according to any one of claims 1 to 7.

9. The display substrate according to claim 8, wherein: The display substrate further includes a signal processing circuit, and the signal processing circuit includes an isolation module and a processing module; The input signal terminal of the isolation module is connected to the output signal terminal of the voltage conversion module, and the output signal terminal of the isolation module is connected to the input signal terminal of the processing module; The first power supply voltage terminal of the isolation module is connected to the power supply voltage terminal of the voltage conversion module, the first ground terminal of the isolation module is connected to the ground terminal of the voltage conversion module, the second power supply voltage terminal of the isolation module is respectively connected to the positive voltage power supply and the power supply voltage terminal of the processing module, and the second ground terminal of the isolation module is respectively connected to the digital ground and the ground terminal of the processing module; The isolation module is configured to receive the digital quantity sampling result output by the voltage conversion module and report the digital quantity sampling result to the processing module; The processing module is configured to receive the digital quantity sampling result reported by the isolation module, compare the digital quantity sampling result with a preset range, and issue an alarm signal if the digital quantity sampling result deviates from the preset range.

10. The display substrate according to claim 9, wherein: The isolation module includes a bidirectional I2C isolator, and the processing module includes a main processor; The input signal pin of the bidirectional I2C isolator is connected to the output signal end of the voltage conversion module, and the output signal pin of the bidirectional I2C isolator is connected to the input signal pin of the main processor; The first power supply voltage pin of the bidirectional I2C isolator is connected to the power supply voltage end of the voltage conversion module, the first ground pin of the bidirectional I2C isolator is connected to the ground end of the voltage conversion module, the second power supply voltage pin of the bidirectional I2C isolator is respectively connected to the positive voltage power supply and the power supply voltage pin of the main processor, and the second ground pin of the bidirectional I2C isolator is respectively connected to the digital ground and the ground pin of the main processor.

Images