Light source control circuit, display screen and intelligent terminal

Abstract

The utility model discloses a light source control circuit, a display screen and an intelligent terminal, the light source control circuit comprises a boost circuit, the boost circuit is electrically connected with a backlight module, the boost circuit comprises a first feedback end, and the boost circuit is used for boosting the voltage input by a power management chip and outputting the boosted voltage to the backlight module. The temperature sensing module is electrically connected with the first feedback end and used for sensing the temperature of the backlight module, and the main control module is electrically connected with the temperature sensing module and used for generating a driving signal and outputting the driving signal to the first feedback end through the temperature sensing module; wherein the temperature sensing module is configured to adjust the voltage amplitude of the driving signal according to the temperature of the backlight module.

Description

Technical Field

[0001] This utility model relates to the field of circuit technology, and in particular to a light source control circuit, a display screen, and a smart terminal. Background Technology

[0002] Liquid crystal display modules (LCMs) are widely used display components in smart terminals, primarily responsible for providing clear image display. Their performance significantly impacts the user experience of terminal devices. The operating environment of the LCM is crucial to its performance and lifespan, especially temperature. LCD screens require a certain temperature range to function properly. When the temperature is too high, the fluidity of liquid crystal molecules increases, potentially leading to color distortion, decreased brightness, and even light decay. Furthermore, sustained high temperatures can cause open circuits or other malfunctions in the screen, severely affecting the stability and lifespan of the device.

[0003] Existing LCD module driving circuits typically adjust backlight brightness through external control chips or fixed hardware parameters to meet display requirements in different scenarios.

[0004] However, with the diversification of smart terminal application scenarios, the working environment of LCMs has become increasingly complex. For example, high-temperature outdoor scenarios (such as payment terminals in open-air parking lots or outdoor visitor machines) cause LCD modules to be in a high-temperature state for a long time. Since the existing technology lacks a circuit that can dynamically adjust the backlight brightness according to the LCM temperature, when the ambient temperature is high, the surface temperature of the LCM may exceed its design tolerance range, resulting in a decrease in display effect or even physical damage. Utility Model Content

[0005] The main purpose of this invention is to propose a light source control circuit that aims to solve the problem of not being able to dynamically adjust the backlight brightness according to the temperature of the liquid crystal display module.

[0006] To achieve the above objectives, this utility model proposes a light source control circuit for adjusting the backlight of a display screen, wherein the display screen includes a backlight module, and the light source control circuit includes:

[0007] A boost circuit is electrically connected to the backlight module. The boost circuit includes a first feedback terminal. The boost circuit is used to boost the voltage input to the power management chip and output the boosted voltage to the backlight module.

[0008] A temperature sensing module, which is electrically connected to the first feedback terminal, is used to sense the temperature of the backlight module.

[0009] The main control module is electrically connected to the temperature sensing module. The main control module is used to generate a drive signal and output it to the first feedback terminal via the temperature sensing module.

[0010] The temperature sensing module is configured to adjust the voltage amplitude of the driving signal according to the temperature of the backlight module.

[0011] In some embodiments, the temperature sensing module includes a temperature sensing device, which includes a first terminal and a second terminal. The first terminal of the temperature sensing device is electrically connected to the main control module, and the second terminal of the temperature sensing device is electrically connected to the first feedback terminal. The temperature sensing device is configured to change its resistance based on the temperature of the backlight module.

[0012] In some embodiments, the temperature sensing device is a negative temperature coefficient thermistor.

[0013] In some embodiments, the temperature sensing module further includes a filtering module, which is electrically connected to the main control module and the temperature sensing device, and is used to filter the drive signal generated by the main control module.

[0014] In some embodiments, the filtering module includes a first resistor and a first capacitor. The first terminal of the temperature sensing device is electrically connected to the main control module through the first resistor. The second terminal of the temperature sensing device is grounded through the first capacitor. The second terminal of the temperature sensing device is also electrically connected to the first feedback terminal.

[0015] In some embodiments, the boost circuit includes:

[0016] A boost converter module, the boost converter module including a first connection terminal, a control terminal and a first output terminal, the first connection terminal being used to electrically connect to a power management chip, and the first output terminal being electrically connected to the backlight module;

[0017] The boost converter chip includes a second output terminal, which is electrically connected to the control terminal. The boost converter chip is used to control the working state of the boost conversion module.

[0018] In some embodiments, the boost chip further includes a second feedback terminal;

[0019] The boost circuit also includes a voltage divider, which includes a second resistor and a third resistor. One end of the second resistor is electrically connected to the first feedback terminal, and the other end of the second resistor is electrically connected to the backlight module via the third resistor. The second feedback terminal is electrically connected to the other end of the second resistor.

[0020] In some embodiments, the boost converter module includes an inductor, a switching transistor, and a unidirectional conductor;

[0021] One end of the inductor is electrically connected to the power management chip, and the other end of the inductor is electrically connected to the backlight module via the unidirectional conductor. One conducting end of the switch is electrically connected to the other end of the inductor, and the other conducting end of the switch is grounded. The gate of the switch is electrically connected to the control terminal.

[0022] The present invention further proposes a display screen, including a backlight module, the backlight module including a positive connection terminal and a negative connection terminal and a light source control circuit as described in the foregoing embodiments.

[0023] This utility model further proposes a smart terminal, including the display screen of the aforementioned embodiment.

[0024] The beneficial effect of this utility model is that by setting a temperature sensing module to detect the temperature change of the backlight module in real time and combining it with the drive signal generated by the main control module, the backlight brightness can be dynamically adjusted according to the temperature, thereby effectively reducing the heat generation of the backlight module under high temperature conditions. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the module electrical connections of the light source control circuit in one embodiment of the present invention;

[0026] Figure 2 This is a circuit diagram of the light source control circuit in one embodiment of the present invention.

[0027] Explanation of icon numbers:

[0028] 10. Display screen; 12. Backlight module;

[0029] 100. Boost circuit; A1. First feedback terminal;

[0030] 120. Boost converter module; A2. First connection terminal; B1. Control terminal; A3. First output terminal; L1. Inductor; Q1. Switching transistor; D1. Unidirectional conduction component;

[0031] U1, boost converter chip; A4, second output terminal; B2, second feedback terminal;

[0032] 140, voltage divider; R2, second resistor; R3, third resistor;

[0033] 200. Temperature sensing module;

[0034] RT, temperature sensing device; B3, first terminal; B4, second terminal;

[0035] 240. Filter module; R1. First resistor; C1. First capacitor;

[0036] 300. Main control module.

[0037] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0038] The solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0039] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.

[0040] It should also be noted that when a component is described as "fixed to" or "set on" another component, it can be directly on the other component or there may be an intervening component present. When a component is described as "connected to" another component, it can be directly connected to the other component or there may be an intervening component present.

[0041] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.

[0042] Liquid crystal display (LCM) modules are a crucial component of smart terminals, widely used to provide users with intuitive visual output. The performance of an LCM is highly dependent on ambient temperature. Excessive temperature increases the fluidity of liquid crystal molecules, potentially affecting display quality, such as color distortion, decreased brightness, and even light decay. With the widespread adoption of smart terminals in various scenarios, the operating environment of LCMs is becoming increasingly complex. For example, in payment terminals in open-air parking lots or outdoor visitor machines, LCMs may be exposed to high temperatures for extended periods, exceeding their design range and leading to decreased display performance or even physical damage. However, existing technologies lack control circuits that dynamically adjust backlight brightness based on LCM temperature changes. Therefore, this invention proposes a light source control circuit. For details, please refer to... Figure 1 This utility model embodiment proposes a light source control circuit for adjusting the backlight of a display screen, the display screen including a backlight module 12, and the light source control circuit including:

[0043] A boost circuit 100 is electrically connected to the backlight module 12. The boost circuit 100 includes a first feedback terminal A1. The boost circuit 100 is used to boost the voltage input to the power management chip and output the boosted voltage to the backlight module 12.

[0044] Temperature sensing module 200 is electrically connected to the first feedback terminal A1 and is used to sense the temperature of backlight module 12.

[0045] The main control module 300 is electrically connected to the temperature sensing module 200. The main control module 300 is used to generate drive signals and output them to the first feedback terminal A1 via the temperature sensing module 200.

[0046] The temperature sensing module 200 is configured to adjust the voltage amplitude of the drive signal according to the temperature of the backlight module 12.

[0047] In this embodiment, the light source control circuit is used for backlight adjustment of the display screen, including a boost circuit 100, a temperature sensing module 200, and a main control module 300. The boost circuit 100 is electrically connected to the backlight module 12, and its function is to boost the voltage input to the power management chip to ensure that the backlight module 12 obtains the required operating voltage. The boost circuit 100 can use commercially available boost chips U1, such as LT1074, SY7711, etc., or it can be implemented by building its own boost circuit 100. The boost circuit 100 includes a first feedback terminal A1. By adjusting the voltage of the first feedback terminal A1, the output voltage can be controlled. In this embodiment, the higher the voltage applied to the first feedback terminal A1, the lower the output voltage of the boost circuit 100; conversely, the lower the voltage of the first feedback terminal A1, the higher the output voltage of the boost circuit 100. For example, when using LT1074 as the boost chip U1, the voltage at its feedback terminal can be used to control the stable output voltage value.

[0048] The function of the temperature sensing module 200 is to provide real-time feedback when the temperature of the backlight module 12 changes. Various devices can be used to implement the temperature sensing module 200, such as negative temperature coefficient (NTC) thermistors, digital temperature sensors (e.g., DS18B20), or thermocouples. NTC thermistors have decreasing resistance as the temperature rises, digital temperature sensors can directly provide temperature data, and thermocouples can sense temperature changes by generating a voltage signal based on temperature differences. This embodiment utilizes this characteristic of NTC thermistors. As for installation, the temperature sensing module 200 can be placed in close contact with the surface of the backlight module 12 to sense temperature changes in the module.

[0049] The main control module 300 is responsible for generating the drive signal and outputting the signal to the first feedback terminal A1 of the boost circuit 100 through the temperature sensing module 200. The main control module 300 can use a common microcontroller (such as STM32) or a dedicated drive control chip. In this embodiment, the temperature sensing module 200 adjusts the voltage amplitude of the drive signal according to the temperature change of the backlight module 12. By utilizing the characteristics of the NTC thermistor, the resistance value decreases when the temperature rises, thereby reducing the feedback terminal voltage and ultimately affecting the output voltage of the boost circuit 100.

[0050] In actual operation, when the temperature of the backlight module 12 is within the normal range, the resistance of the NTC thermistor in the temperature sensing module 200 is maintained at a high level. At this time, the driving signal generated by the main control module 300 is fed back to the first feedback terminal A1 of the boost circuit 100 after passing through the temperature sensing module 200. The voltage is low, and the boost circuit 100 will output a higher voltage to ensure that the brightness of the backlight module 12 meets the design requirements.

[0051] When the temperature of the backlight module 12 rises and exceeds the preset operating range, the resistance of the NTC thermistor decreases, causing the voltage at the feedback terminal to rise, thereby reducing the output voltage of the boost circuit 100. During this process, the brightness of the backlight module 12 is automatically reduced to decrease its own heat generation, prevent display failures caused by overheating, and protect the stable operation of the LCM.

[0052] The beneficial effects of this utility model are that by setting a temperature sensing module 200 to detect the temperature change of the backlight module 12 in real time and combining it with the drive signal generated by the main control module 300, the backlight brightness can be dynamically adjusted according to the temperature, thereby effectively reducing the heat generation of the backlight module 12 under high-temperature conditions. By reducing the backlight brightness to reduce the temperature of the LCM, it is possible to effectively prevent color distortion, light decay, and other phenomena caused by excessively rapid liquid crystal molecule flow, extend the service life of the liquid crystal display module, and improve the stability and reliability of the equipment in harsh environments.

[0053] See Figure 2 In this embodiment, the temperature sensing module 200 includes a temperature sensing device RT, which includes a first terminal B3 and a second terminal B4. The first terminal B3 of the temperature sensing device RT is electrically connected to the main control module 300, and the second terminal B4 of the temperature sensing device RT is electrically connected to the first feedback terminal A1. The temperature sensing device RT is configured to change its resistance based on the temperature of the backlight module 12.

[0054] In this embodiment, the temperature sensing module 200 is used to monitor the temperature of the backlight module 12 in real time and to dynamically adjust the backlight brightness by adjusting the voltage amplitude of the drive signal. The temperature sensing module 200 includes a temperature sensing device RT, which has two connection terminals: a first terminal B3 and a second terminal B4.

[0055] Terminal B3 is electrically connected to the main control module 300 to receive the drive signal generated by the main control module 300. This drive signal can be a PWM signal, and the function of the temperature sensor RT is to adjust the voltage amplitude of the PWM signal. The temperature sensor RT is a thermistor with a negative temperature coefficient (NTC) characteristic, and its resistance value changes with the temperature of the backlight module 12. When the temperature of the backlight module 12 increases, the resistance value of the temperature sensor RT decreases, and vice versa.

[0056] The second terminal B4 is electrically connected to the first feedback terminal A1 of the boost circuit 100. The temperature sensing device RT affects the voltage at the first feedback terminal A1 by changing its own resistance. Specifically, when the resistance of the temperature sensing device RT decreases, the voltage at the first feedback terminal A1 increases; when the resistance increases, the voltage at the first feedback terminal A1 decreases.

[0057] The voltage at the first feedback terminal A1 changes accordingly based on the resistance change of the temperature sensing device RT, thus affecting the output voltage of the boost circuit 100. When the voltage at the first feedback terminal A1 increases, the output voltage of the boost circuit 100 decreases; conversely, when the voltage at the first feedback terminal A1 decreases, the output voltage of the boost circuit 100 increases. Therefore, by adjusting the amplitude of the PWM signal through the temperature sensing module 200, the output voltage of the boost circuit 100 is indirectly controlled, thereby adjusting the brightness of the backlight module 12.

[0058] Based on the above working principle, the temperature sensing module 200 achieves real-time monitoring and adjustment of the temperature of the backlight module 12. When the temperature is high, the resistance of the temperature sensing device RT decreases, causing the output voltage of the boost circuit 100 to decrease, thereby reducing the brightness of the backlight module 12, reducing its heat generation, and avoiding physical damage caused by prolonged high temperatures. This mechanism ensures that the backlight module 12 always remains within a safe operating range under different ambient temperatures, effectively extending its service life.

[0059] Furthermore, the temperature sensing device RT is a negative temperature coefficient thermistor.

[0060] In this embodiment, the NTC thermistor in the temperature sensing module 200 can be selected from several common models, such as B57891M0104J000, MF58-100K, and NTC thermistor 10K (100K at 25°C). B57891M0104J000 offers high accuracy and stability, is suitable for a wide temperature range, and is typically used in temperature monitoring and protection circuits. The MF58 series is a common NTC thermistor with a negative temperature coefficient, suitable for temperature compensation and over-temperature protection. Its operating temperature range is typically -40°C to +125°C, and it is widely used in consumer electronics and home appliances. The NTC thermistor 10K (100K at 25°C) has a typical resistance of 10KΩ or 100KΩ, exhibits good temperature response at 25°C, and is suitable for battery management systems and other temperature sensing devices.

[0061] These NTC thermistors possess excellent temperature sensitivity and adaptability, effectively responding to temperature changes in the backlight module 12. By altering their resistance values, they adjust the voltage amplitude of the PWM signal, influencing the voltage at the first feedback terminal A1 of the boost circuit 100, ultimately achieving brightness adjustment of the backlight module 12.

[0062] See Figure 2In this embodiment, the temperature sensing module 200 further includes a filtering module 240, which is electrically connected to the main control module 300 and the temperature sensing device RT. The filtering module 240 is used to filter the drive signal generated by the main control module 300.

[0063] In this embodiment, in addition to the aforementioned temperature sensing device RT, the temperature sensing module 200 also includes a filtering module 240. Its function is to filter the drive signal (e.g., PWM signal) generated by the main control module 300 to improve the system's stability and accuracy. The filtering module 240 works in conjunction with the temperature sensing device RT to ensure signal quality and avoid signal noise interference.

[0064] The specific structure of the filtering module 240 includes its connection to the main control module 300 and the temperature sensing device RT. The filtering module 240 is electrically connected to the main control module 300 and the temperature sensing device RT. Its main function is to filter the PWM signal from the main control module 300, filtering out high-frequency noise or unstable signal components to ensure that the temperature sensing device RT can receive a stable and clear signal.

[0065] The filter module 240 works by removing high-frequency noise from the PWM signal through low-pass filtering or other appropriate filtering methods. Specifically, the filter module 240 can include the following common circuit designs:

[0066] 1. An RC low-pass filter is formed by connecting a resistor in series and a capacitor in parallel along the path of the PWM signal. This filter can effectively remove high-frequency components from the PWM signal, retaining only the lower-frequency signal, ensuring that the temperature sensing device RT can receive a stable voltage signal.

[0067] 2. An LC low-pass filter is formed by connecting an inductor L1 in series and a capacitor in parallel. Compared to an RC filter, an LC filter has better high-frequency noise suppression and is suitable for applications requiring high signal purity.

[0068] Regardless of the type of filter used, the goal is to eliminate signal instability caused by power fluctuations, interference, or other noise sources without changing the effective components of the PWM signal, so that the temperature sensing device RT can accurately sense changes in the PWM signal and adjust the brightness of the backlight module 12 accordingly.

[0069] In this embodiment, the addition of the filtering module 240 can improve the accuracy and anti-interference capability of the system. After the PWM signal output by the main control module 300 passes through the filtering module 240, the temperature sensing device RT can receive a smooth, noise-free signal, thereby more accurately adjusting the voltage amplitude of the PWM signal according to the temperature change of the backlight module 12.

[0070] Specifically, the filter module 240 ensures that the temperature sensing device RT can operate in a low-noise environment by removing high-frequency noise and other unnecessary signal fluctuations, thereby improving the response speed and stability of the temperature detection and regulation process.

[0071] Continue reading Figure 2 In this embodiment, the filter module 240 includes a first resistor R1 and a first capacitor C1. The first terminal B3 of the temperature sensing device RT is electrically connected to the main control module 300 through the first resistor R1. The second terminal B4 of the temperature sensing device RT is grounded through the first capacitor C1. The second terminal B4 of the temperature sensing device RT is also electrically connected to the first feedback terminal A1.

[0072] In this embodiment, the filter module 240 is designed using an RC filter circuit. Specifically, the filter module 240 consists of a first resistor R1 and a first capacitor C1, and is mainly used to filter the PWM signal received by the temperature sensing device RT, thereby ensuring the stability and accuracy of the signal.

[0073] The first terminal B3 is electrically connected to the main control module 300 and is used to receive the PWM signal generated by the main control module 300.

[0074] The second terminal B4 is first grounded through the first capacitor C1 to filter high-frequency noise. The second terminal B4 is also electrically connected to the first feedback terminal A1 through the first resistor R1 to feed the filtered signal back to the boost circuit 100.

[0075] In this embodiment, the RC filter circuit works as follows: the main control module 300 generates a PWM signal and transmits it to the temperature sensing device RT through the first terminal B3. When the PWM signal is transmitted to the second terminal B4 of the temperature sensing device RT, the signal is grounded through the first capacitor C1 connected in parallel to the second terminal B4, removing high-frequency noise and other unnecessary interference from the signal. The function of the first capacitor C1 is to smooth high-frequency components, reduce noise components in the signal, and ensure signal clarity and stability.

[0076] The filtered signal is transmitted to the first feedback terminal A1 through the first resistor R1. The feedback signal affects the operating state of the boost circuit 100 based on the change in resistance of the temperature sensing device RT. When the temperature rises, the resistance of the temperature sensing device RT (NTC thermistor) decreases, causing the voltage at the feedback terminal to rise, thereby reducing the output voltage of the boost circuit 100 and adjusting the brightness of the backlight module 12.

[0077] The change in resistance of the temperature sensing device RT not only affects the amplitude of the PWM signal, but also adjusts the voltage at the feedback terminal through the change in resistance, thereby controlling the output voltage of the boost circuit 100. In this way, when the temperature of the backlight module 12 is too high, the boost circuit 100 will adjust the output voltage to reduce the backlight brightness and prevent overheating.

[0078] By adding an RC filter circuit to the temperature sensing module 200, this embodiment effectively improves the stability of the PWM signal and reduces signal fluctuations caused by high-frequency noise and interference. In the feedback loop of the temperature sensing device RT, the addition of the filter circuit makes the signal more stable and accurate, which helps to achieve more precise temperature regulation. Especially when the backlight module 12 operates at higher temperatures, the filtered signal ensures that the boost circuit 100 can respond appropriately to changes in the feedback.

[0079] Continue reading Figure 2 In this embodiment, the boost circuit 100 includes:

[0080] The boost converter module 120 includes a first connection terminal A2, a control terminal B1 and a first output terminal A3. The first connection terminal A2 is used to electrically connect to the power management chip, and the first output terminal A3 is electrically connected to the backlight module 12.

[0081] The boost chip U1 includes a second output terminal A4, which is electrically connected to the control terminal B1. The boost chip U1 is used to control the working state of the boost conversion module 120.

[0082] In this embodiment, the boost converter module 120 is one of the core components of the boost circuit 100. Its main function is to convert the voltage of the input power supply into the required higher voltage through the boost process and output it to the backlight module 12.

[0083] The first connection terminal A2 is used to electrically connect to the power management chip and receive the voltage signal from the input power supply.

[0084] Control terminal B1 is used to receive control signals from boost chip U1, thereby adjusting the operating state of boost converter module 120. Changes in the control signals will directly affect the output voltage of boost converter module 120.

[0085] The first output terminal A3 is electrically connected to the backlight module 12, and the output voltage is used by the backlight module 12 to control the brightness of the display screen. The boost converter module 120 increases the voltage and stabilizes the output voltage through its internal circuitry according to the control signal and the input voltage.

[0086] The boost converter chip U1 is an important component used to control the operating state of the boost converter module 120. Its function is to adjust the operating frequency and voltage of the boost converter module 120 according to the external input signal, thereby ensuring that the output voltage meets the requirements of the backlight module 12.

[0087] The second output terminal A4 is electrically connected to the control terminal B1 of the boost converter module 120, providing a control signal to adjust the operating state of the boost converter module 120. The boost chip U1 adjusts the signal at the control terminal B1, enabling the boost converter module 120 to perform boost operation according to real-time requirements.

[0088] In this embodiment, the boost circuit 100 operates by using a power management chip to provide input voltage, which is transmitted to the boost conversion module 120 via its first connection terminal A2. This input voltage level is low and insufficient to directly drive the backlight module 12. Therefore, the boost chip U1 transmits a control signal to the control terminal B1 of the boost conversion module 120 via its second output terminal A4. By adjusting the operating frequency and boost coefficient, the boost conversion module 120 is controlled to increase the input voltage to a suitable operating voltage for the backlight module 12. The boost conversion module 120 then adjusts its output voltage according to the control signal and outputs the boosted voltage to the backlight module 12 via its first output terminal A3. The backlight module 12 adjusts the brightness of its display screen based on the received voltage signal.

[0089] In this embodiment, the boost circuit 100 stably provides the required voltage to the backlight module 12, ensuring the brightness adjustment of the backlight module 12 under different operating conditions. Simultaneously, the coordinated operation of the boost chip U1 and the boost conversion module 120 enables the boost circuit 100 to adjust the output voltage according to actual needs, ensuring the display effect and stability of the screen.

[0090] Continue reading Figure 2 Furthermore, the boost converter module 120 includes an inductor L1, a switching transistor Q1, and a unidirectional conductor D1;

[0091] One end of inductor L1 is electrically connected to the power management chip, and the other end of inductor L1 is electrically connected to the backlight module 12 via unidirectional conductor D1. One conducting end of switch Q1 is electrically connected to the other end of inductor L1, and the other conducting end of switch Q1 is grounded. The gate of switch Q1 is electrically connected to the control terminal B1.

[0092] In this embodiment, the boost converter module 120 adopts the classic boost circuit 100 structure, including components such as inductor L1, switching transistor Q1, and unidirectional conductor D1 (such as a diode). The boost circuit 100 works in concert with these components to increase the input voltage to the required output voltage to drive the backlight module 12.

[0093] Inductor L1 is a key component in the boost circuit 100, responsible for storing and releasing energy. One end of inductor L1 is electrically connected to the power management chip to receive the input voltage signal, and the other end is electrically connected to the backlight module 12 through the unidirectional conductor D1.

[0094] In the boost circuit 100, the switching transistor Q1 controls the current flow. One of its conducting terminals is electrically connected to the other end of the inductor L1, and the other conducting terminal is grounded. The gate of the switching transistor Q1 is electrically connected to the control terminal B1 of the boost circuit 100, which is used to control the switching transistor Q1 to turn on and off.

[0095] The unidirectional conductor D1 is typically a diode, and its function is to ensure that current flows only in the correct direction, preventing reverse current from affecting the boost process. The unidirectional conductor D1 electrically connects the other end of the inductor L1 to the backlight module 12, ensuring that electrical energy flows from the inductor L1 to the backlight module 12.

[0096] The boost circuit 100 operates based on the energy storage and release of inductor L1 and the switching control of switching transistor Q1. In this embodiment, the adjustment of the boost circuit 100 depends not only on the operation of inductor L1, but also on the control of boost chip U1 and the feedback of NTC temperature sensor RT to adjust the output voltage according to the temperature change of backlight module 12. The specific working process is as follows:

[0097] The temperature sensing module 200 includes a negative temperature coefficient (NTC) thermistor, which changes its resistance value as the temperature of the backlight module 12 changes. One end of the NTC thermistor is electrically connected to the main control module 300, and the other end is connected to the feedback terminal (FB pin) of the boost circuit 100.

[0098] When the temperature of the backlight module 12 rises, the resistance of the NTC thermistor decreases, which leads to an increase in the voltage applied to the FB pin (i.e., the self-resistance decreases, and the voltage amplitude of the PWM signal, i.e., the drive signal, increases), thereby affecting the operating state of the boost converter chip U1. The boost converter chip U1 adjusts the signal at the control terminal B1 to change the on and off state of the switching transistor Q1, ultimately regulating the output voltage of the boost converter module 120.

[0099] The boost chip U1 adjusts the signal from the control terminal B1 based on the feedback voltage provided by the temperature sensing module 200, thereby controlling the operating state of the switching transistor Q1. When the temperature of the backlight module 12 is high, the decrease in the NTC resistor increases the voltage at the FB pin, causing the boost chip U1 to output a lower drive voltage, reducing the brightness of the backlight module 12, and thus reducing the heat generated by the backlight module 12.

[0100] Conversely, when the temperature of the backlight module 12 is low, the resistance of the NTC thermistor increases, the voltage of the FB pin decreases, and the boost chip U1 increases the output voltage to improve the brightness of the backlight module 12 and ensure its display effect.

[0101] When the control signal of the boost chip U1 turns on the switch Q1, the inductor L1 starts to charge and stores energy; when the switch Q1 turns off, the inductor L1 releases energy and flows to the backlight module 12 through the unidirectional conductor D1, completing the boost conversion of electrical energy.

[0102] By adjusting the frequency and duty cycle of the control signal, the boost circuit 100 can precisely control the output voltage of the backlight module 12 to adapt to different working environments and temperature changes.

[0103] In this embodiment, the boost circuit 100 combines the classic boost conversion principle with NTC temperature sensing technology to dynamically adjust the output voltage according to the temperature changes of the backlight module 12. This adjustment mechanism ensures that the backlight module 12 can automatically reduce brightness in high-temperature environments, reducing the risk of overheating and thus extending its service life. Simultaneously, in low-temperature environments, the boost circuit 100 can automatically increase brightness to maintain optimal display performance.

[0104] By combining the boost chip U1 with the temperature change feedback of the NTC thermistor, the boost circuit 100 in this embodiment can work stably under different temperature conditions, providing efficient power conversion and temperature control functions to meet the dynamic requirements of the backlight module 12.

[0105] In some embodiments, the temperature sensing device RT can be combined with the first resistor R1 to form a drive signal voltage divider 140, which is used to perform voltage division processing on the drive signal (such as PWM signal) generated by the main control module 300.

[0106] Specifically, in this embodiment, the temperature sensing device RT is an NTC thermistor, and its resistance value changes with the temperature of the backlight module 12. The first terminal B3 of the temperature sensing device RT is electrically connected to the main control module 300 and receives the drive signal generated by the main control module 300.

[0107] The first resistor R1 is connected in series with the temperature sensing device RT to form a voltage divider circuit 140. The other end of the first resistor R1 is connected to the input terminal of the drive signal. In this way, the amplitude of the PWM voltage can be reduced, which can effectively control the upper limit of the output voltage of the boost circuit 100.

[0108] Furthermore, the boost chip U1 also includes a second feedback terminal B2;

[0109] The boost circuit 100 further includes a voltage divider 140, which includes a second resistor R2 and a third resistor R3. One end of the second resistor R2 is electrically connected to the first feedback terminal A1, and the other end of the second resistor R2 is electrically connected to the backlight module 12 via the third resistor R3. The second feedback terminal B2 is electrically connected to the other end of the second resistor R2.

[0110] In this embodiment, the boost chip U1 boosts the input voltage to the target output voltage to supply the backlight module 12 or other loads. The first feedback terminal A1 (FB) continuously monitors the main output voltage and adjusts the operating state of the boost chip U1 through the feedback loop to ensure stable output voltage. The second feedback terminal B2 is connected to one end of the voltage divider 140 through the second resistor R2, and the other end is connected to the backlight module 12 or an optional LED / first output terminal A3 through the third resistor R3.

[0111] Voltage divider 140 divides the output voltage and feeds it back to the second feedback terminal B2, thereby transmitting an appropriate proportion of voltage to the FB pin and ensuring that the voltage fed back to the FB pin is within the safe range allowed by the boost chip U1.

[0112] The design of the voltage divider 140 effectively reduces the feedback voltage directly applied to the FB pin, preventing damage to the FB pin due to excessive voltage.

[0113] The second feedback terminal B2 not only provides feedback on the output voltage, but can also be selectively connected to the LED or the first output terminal A3 to achieve multi-path feedback. This helps the circuit to self-regulate under different load conditions and maintain a stable output voltage.

[0114] In the aforementioned embodiments, the voltage of the drive signal is applied to the FB pin. The feedback voltage at the second feedback terminal B2, adjusted by the voltage divider 140, ensures that the total voltage received by the FB pin is within a safe range, while simultaneously achieving precise control of the boost chip U1.

[0115] By introducing a second feedback terminal B2 and cooperating with a voltage divider 140 for voltage regulation, the boost circuit 100 in this embodiment achieves self-feedback self-tuning, ensuring the stability of the output voltage and the safety of the circuit. This design not only improves the reliability and adaptability of the circuit but also provides greater design flexibility, making it suitable for various practical application scenarios.

[0116] This utility model further proposes a display screen, including a backlight module 12, which includes a positive connection terminal, a negative connection terminal, and a light source control circuit. The specific structure of the light source control circuit is as described in the above embodiments. Since this second aspect adopts all the technical solutions of all the above embodiments, it at least has all the technical effects brought about by the technical solutions of the above embodiments, and will not be described in detail here.

[0117] The display screen described in this invention can be used in various display devices requiring a stable backlight, such as liquid crystal displays (LCDs) and organic light-emitting diode displays (OLEDs). Its self-feedback, self-tuning light source control circuit is particularly suitable for high-end display devices, automotive displays, portable electronic devices, and other applications with high requirements for display quality and power stability. Furthermore, it integrates a temperature-based light source control circuit. This temperature regulation function can monitor the temperature changes of the display screen's operating environment in real time and dynamically adjust the brightness output of the backlight module 12 based on the temperature data.

[0118] This invention further proposes a smart terminal, including the display screen of the aforementioned embodiment. This smart terminal can be applied to various devices, such as smartphones, tablets, smartwatches, in-vehicle display systems, portable outdoor display devices, and wearable devices. Whether used indoors or in complex outdoor environments, this smart terminal provides stable and efficient display performance. The display screen is installed in the main body of the smart terminal, serving as the core component for user interaction and information display. Combined with the backlight module 12 and the light source control circuit, it achieves excellent display effects and energy management capabilities.

[0119] In practical applications, such as in high-temperature outdoor environments, the smart terminal operates as follows: Increased ambient temperature leads to a rise in the operating temperature of the display screen and backlight module 12. The light source control circuit monitors the temperature changes of the display screen and backlight module 12 in real time using a built-in temperature sensor. Based on these temperature changes, it adjusts its resistance to regulate the voltage applied to the first feedback terminal A1, automatically adjusting the brightness output of the backlight module 12. This reduces backlight brightness to minimize heat generation, effectively controlling the display's operating temperature and preventing performance degradation or device damage due to overheating. Conversely, in lower-temperature environments, the light source control circuit appropriately increases backlight brightness to ensure clear visibility of the displayed content and enhance the user's visual experience. This dynamic adjustment mechanism allows the smart terminal to maintain optimal display performance and device capabilities under various environmental conditions.

[0120] The above description is only a part or preferred embodiment of this utility model. Neither the text nor the drawings should limit the scope of protection of this utility model. All equivalent structural transformations made using the content of this utility model specification and drawings under the overall concept of this utility model, or direct / indirect applications in other related technical fields, are included within the scope of protection of this utility model.

Claims

1. A light source control circuit for backlight adjustment of a display screen, the display screen comprising a backlight module, characterized in that, The light source control circuit comprises: a boost circuit electrically connected to the backlight module, the boost circuit comprising a first feedback end, the boost circuit being configured to boost a voltage input by a power management chip and output the boosted voltage to the backlight module; a temperature sensing module electrically connected to the first feedback end, the temperature sensing module being configured to sense a temperature of the backlight module; a master control module electrically connected to the temperature sensing module, the master control module being configured to generate a driving signal and output the driving signal to the first feedback end via the temperature sensing module; wherein the temperature sensing module is configured to adjust a voltage amplitude of the driving signal according to the temperature of the backlight module.

2. The light source control circuit according to claim 1, characterized in that, The temperature sensing module comprises a temperature sensing device, the temperature sensing device comprising a first end and a second end, the first end of the temperature sensing device being electrically connected to the master control module, the second end of the temperature sensing device being electrically connected to the first feedback end, the temperature sensing device being configured to change its resistance value based on the temperature of the backlight module.

3. The light source control circuit of claim 2, wherein, The temperature sensing device is a negative temperature coefficient thermistor.

4. The light source control circuit of claim 2, wherein, The temperature sensing module further comprises a filter module, the filter module being electrically connected to the master control module and the temperature sensing device, the filter module being configured to filter the driving signal generated by the master control module.

5. The light source control circuit of claim 4, wherein, The filter module comprises a first resistor and a first capacitor, the first end of the temperature sensing device being electrically connected to the master control module via the first resistor, the second end of the temperature sensing device being grounded via the first capacitor, the second end of the temperature sensing device being further electrically connected to the first feedback end.

6. The light source control circuit of claim 1, wherein, The boost circuit comprises: a boost conversion module comprising a first connection end, a control end and a first output end, the first connection end being configured to electrically connect to a power management chip, the first output end being electrically connected to the backlight module; a boost chip comprising a second output end, the second output end being electrically connected to the control end, the boost chip being configured to control an operating state of the boost conversion module.

7. The light source control circuit of claim 6, wherein, The boost chip further comprises a second feedback end; The boost circuit further comprises a voltage divider, the voltage divider comprising a second resistor and a third resistor, one end of the second resistor being electrically connected to the first feedback end, the other end of the second resistor being electrically connected to the backlight module via the third resistor; the second feedback end being electrically connected to the other end of the second resistor.

8. The light source control circuit of claim 6, wherein, The boost conversion module comprises an inductor, a switch tube and a unidirectional conduction element; wherein one end of the inductor is electrically connected to the power management chip, the other end of the inductor is electrically connected to the backlight module via the unidirectional conduction element, one conduction end of the switch tube is electrically connected to the other end of the inductor, the other conduction end of the switch tube is grounded, and a gate of the switch tube is electrically connected to the control end.

9. A display screen, characterized by The display screen comprises a backlight module and a light source control circuit as claimed in any one of claims 1 to 8.

10. A smart terminal, characterized by The display screen comprises the backlight module and the light source control circuit as claimed in any one of claims 1 to 8.

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