Control system and method of energy-saving liquid crystal display screen

Abstract

The invention discloses a control system and method of an energy-saving liquid crystal display screen, and belongs to the technical field of liquid crystal display screen control, and the control system of the energy-saving liquid crystal display screen comprises a photosensitive sensor module which is used for detecting the external illumination intensity and outputting an analog electric signal, the sensor is installed at a specific position of a liquid crystal display screen frame so as to accurately sense ambient light. The microcontroller module is connected with the photosensitive sensor module, receives the analog signal, converts the analog signal, operates a first brightness adjusting algorithm, and sends a control instruction to a liquid crystal display screen driving chip according to a result; and the liquid crystal display screen and the driving chip module are used for adjusting a backlight source of the liquid crystal display screen according to an instruction of the microcontroller to realize multi-stage smooth brightness adjustment. The method has the advantages of improving equipment practicability and energy utilization efficiency, and solves the problem that different brightness cannot be intelligently adapted in different illumination environments in the prior art.

Description

Technical Field

[0001] The invention belongs to the technical field of liquid crystal display screen control, and in particular relates to a control system and method for an energy-saving liquid crystal display screen. Background Art

[0002] With the widespread popularity of electronic devices, liquid crystal displays are widely used as key components of human-computer interaction. Traditional liquid crystal displays have many limitations in terms of brightness control. For a long time, most of them have adopted a fixed brightness setting that remains unchanged. From the beginning of production, they are displayed with a preset brightness value, which cannot be applied to the complex and ever-changing lighting conditions in the actual use scenarios of the equipment. Even if some display screens have a brightness adjustment function, their adjustment methods are simple and crude, and they often preset several brightness levels. When the user switches manually, the screen brightness can only jump stiffly between these limited step-by-step options, making it difficult to achieve a smooth transition.

[0003] In summary, traditional LCD screens often use fixed brightness settings or simple and rough brightness adjustment methods, which cannot intelligently adapt to different lighting environments, affecting the visual experience and causing unnecessary energy waste. For example, the screen is too dark in strong light, resulting in poor visibility, and the screen is too bright and glaring in low light, consuming too much power. At present, there is an urgent need for an efficient, accurate and energy-saving LCD screen control solution that can smoothly switch brightness, in order to improve the practicality and energy efficiency of the equipment. Summary of the invention

[0004] In response to the problems existing in the prior art, the present invention provides a control system and method for an energy-saving liquid crystal display screen, which has the advantages of improving the practicality of the equipment and the energy utilization efficiency, and solves the existing problem of being unable to intelligently adapt to different brightness under different lighting environments.

[0005] The present invention is implemented in this way: a control system of an energy-saving liquid crystal display screen comprises: The light sensor module is used to detect the external light intensity and output analog electrical signals. It is installed at a specific position on the LCD screen frame to accurately sense the ambient light. A microcontroller module is connected to the light sensor module to receive analog signals and convert and process them, run a first brightness adjustment algorithm, and send control instructions to a liquid crystal display driver chip according to the results; The LCD display and driver chip module adjusts the LCD display backlight source according to the microcontroller instructions to achieve multi-level smooth brightness adjustment.

[0006] As a preferred embodiment of the present invention, the photosensitive sensor module includes: Light sensing element unit: using cadmium sulfide photoresistor, silicon-based photodiode or phototransistor, the light causes the carrier concentration to change and converts the light into an electrical signal; Signal conditioning unit: The amplifier amplifies weak signals, the filter circuit removes noise, and the level conversion circuit adjusts the voltage, so that the output analog electrical signal is suitable for subsequent processing.

[0007] As preferred embodiment of the present invention, the microcontroller module comprises: Signal acquisition unit: Based on the preset sampling frequency and the set timing, it establishes an electrical connection with the output end of the signal conditioning unit of the photosensitive sensor module, accurately collects the input analog electrical signal, and efficiently converts it into a digital coding form; Algorithm operation unit: stores and runs the first brightness adjustment algorithm program code, which is based on the light intensity digital data obtained by the signal acquisition unit, combined with the setting parameters pre-stored in the internal memory of the microcontroller, the setting parameters include the external light intensity is , the screen brightness level is , The total number of preset brightness levels and the minimum light intensity threshold , the maximum light intensity threshold and brightness value array , and perform the calculation according to the following steps: First calculate the continuous brightness level , and then discretized into and ; Finally, the interpolation formula Calculate the appropriate brightness level value and use it as an instruction to control the brightness of the LCD screen; Instruction sending unit: packages the encoded brightness instructions and sends them to the driver chip through the corresponding pins.

[0008] As a preferred embodiment of the present invention, the liquid crystal display screen and the driver chip module include: Driver core unit: converts the brightness level control instructions received from the microcontroller via the communication protocol into the underlying operation instruction set for the backlight source and pixel display control of the LCD display, calculates the current and voltage parameter values ​​of the backlight source for different brightness levels, or generates the duty cycle data of the corresponding pulse width modulation waveform, and coordinates the control of the driving timing, voltage polarity and display-related parameters of the pixel electrodes of the LCD panel; Backlight adjustment unit: When the display screen uses cold cathode fluorescent lamp backlight, a high-precision current driver is used to change the current flowing through the CCFL lamp to increase or decrease the brightness; if an LED backlight is used, the built-in PWM controller is used to adjust the PWM signal duty cycle, and the duty cycle change is used to change the proportion of the LED lamp bead's light emission time, thereby achieving multi-level smooth adjustment of the screen backlight brightness.

[0009] As a preferred embodiment of the present invention, it also includes a human proximity sensor module, which uses an infrared, ultrasonic or microwave induction principle sensor to fully monitor the distance between pedestrians and the screen, and outputs a digital or analog distance signal to a microcontroller for detecting the distance between pedestrians and the liquid crystal display screen; The second brightness adjustment algorithm is used to further adjust the brightness of the LCD screen based on the distance between the pedestrian and the LCD screen on the basis of the first brightness adjustment algorithm.

[0010] As a preferred embodiment of the present invention, the distance between the person and the LCD screen includes a first threshold, a second threshold, a third threshold and a fourth threshold; When a pedestrian approaches the display screen, he first reaches the first threshold, then reaches the second threshold, and then passes the LCD screen. When the pedestrian moves away from the display screen, he successively passes the third threshold and the fourth threshold.

[0011] As a preferred embodiment of the present invention, when the distance between the person and the liquid crystal display screen is outside the first threshold, the second threshold, the third threshold and the fourth threshold, the result of the second brightness adjustment algorithm is the result of the first brightness adjustment algorithm minus a constant; When the distance between the person and the LCD screen is within a first threshold, and the brightness gradually increases from the first threshold to the second threshold; When the distance between the person and the liquid crystal display screen is between the second threshold and the third threshold, the brightness is constant; When the distance between the person and the LCD screen is in the range from the third threshold to the fourth threshold, the brightness decreases.

[0012] As a preferred embodiment of the present invention, the second brightness adjustment algorithm includes: Define the distance threshold between pedestrians and the LCD screen, and set the first threshold to The second threshold is The third threshold is The fourth threshold is ; When the distance between the pedestrian and the screen is outside the threshold, the second brightness adjustment algorithm outputs ; When a pedestrian approaches from a distance, enters the first threshold and approaches the second threshold, the brightness gradually increases according to the linear or nonlinear gradient rule. Set the linear slope , ; The pedestrian is in the range from the second threshold to the third threshold, keeping the current brightness constant ; After the pedestrian passes the screen, the brightness decreases from the third threshold to the fourth threshold according to a linear or nonlinear rule. When the brightness decreases according to a linear rule, the linear slope is set. ,but .

[0013] A control method for an energy-saving liquid crystal display screen comprises the following steps: Detects external light intensity and outputs analog electrical signals. It is installed at a specific position on the LCD screen frame to accurately sense ambient light. Receive the analog signal and convert it, run the first brightness adjustment algorithm, and send a control instruction to the LCD driver chip according to the result; The backlight source of the LCD display is adjusted according to the microcontroller instructions to achieve multi-level smooth brightness adjustment.

[0014] As a preferred embodiment of the present invention, an infrared, ultrasonic or microwave induction principle sensor is used to monitor the distance between pedestrians and the screen in all directions, and output a digital or analog distance signal to a microcontroller for detecting the distance between pedestrians and the LCD screen; The second brightness adjustment algorithm is used to further adjust the brightness of the liquid crystal display screen based on the first brightness adjustment algorithm and according to the distance between the pedestrian and the liquid crystal display screen.

[0015] Compared with the prior art, the present invention has the following beneficial effects: Significant energy saving: Traditional LCD screens often operate at a fixed brightness. In strong light environments, excessive brightness is not only dazzling but also increases energy consumption; in weak light environments, insufficient brightness affects vision and power consumption does not decrease. This control system can dynamically adjust according to external light, appropriately increase the brightness to ensure visibility in strong light, and reduce the brightness in weak light, greatly reducing unnecessary power consumption. Long-term use has a significant energy-saving effect, which is in line with the current low-carbon environmental protection, energy conservation and emission reduction concepts, and reduces equipment operating costs.

[0016] Optimized visual experience: Automatically adaptive multi-level smooth brightness adjustment avoids the stimulation of sudden brightness changes on the human eye. For example, when walking from indoors to outdoor strong light, the screen can be brightened smoothly; from day to dusk, the screen dims quietly, matching the rhythm of ambient light changes throughout the process, so that the viewer's eyes are always in a comfortable visual state, whether in office, home or commercial display scenes, it significantly improves viewing comfort and information acquisition efficiency.

[0017] Extend equipment life: Accurately matching the brightness adjustment of the light reduces the long-term high-load working pressure of the LCD backlight. Reduce the risk of component aging and damage caused by overbrightness and overheating, such as CCFL lamps reduce high current impact, LED lamp beads avoid long-term full-power operation, and overall extend the service life of the display, backlight and related circuit components, reduce the frequency of equipment updates and maintenance costs, and improve product cost performance and durability.

[0018] Intelligent and convenient: The entire brightness adjustment process does not require frequent manual intervention. The system can sense, calculate, and regulate autonomously. In various embedded LCD display devices (mobile phones, tablets, monitors, outdoor advertising screens, etc.), users can focus on content interaction without having to adjust the brightness. Especially in outdoor scenes, the system can automatically adapt to changes in weather, light and shadow, and intelligently integrate into the use environment, improving the usability and humanization of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a system block diagram provided by Embodiment 1 of the present invention; Figure 2 This is a system block diagram provided by Example 2 of the present invention. DETAILED DESCRIPTION

[0020] In order to further understand the content, features and effects of the present invention, the following embodiments are given as examples and described in detail with reference to the accompanying drawings.

[0021] The structure of the present invention is described in detail below in conjunction with the accompanying drawings.

[0022] Example 1 like Figure 1 As shown, an embodiment of the present invention provides a control system for an energy-saving liquid crystal display screen, comprising: The light sensor module is used to detect the external light intensity and output analog electrical signals. It is installed at a specific position on the LCD screen frame to accurately sense the ambient light. A microcontroller module is connected to the light sensor module to receive analog signals and convert and process them, run a first brightness adjustment algorithm, and send control instructions to a liquid crystal display driver chip according to the results; The LCD display and driver chip module adjusts the LCD display backlight source according to the microcontroller instructions to achieve multi-level smooth brightness adjustment.

[0023] Specifically, the photosensitive sensor module includes: Light sensing element unit: using cadmium sulfide photoresistor, silicon-based photodiode or phototransistor, the light causes the carrier concentration to change and converts the light into an electrical signal; Signal conditioning unit: The amplifier amplifies weak signals, the filter circuit removes noise, and the level conversion circuit adjusts the voltage, so that the output analog electrical signal is suitable for subsequent processing.

[0024] In the above setting, the light sensing element unit uses an element that is sensitive to light intensity and has stable photoelectric conversion characteristics, which can be a cadmium sulfide photoresistor, a silicon-based photodiode or a phototransistor. It can cause the internal carrier concentration to change based on light excitation, thereby converting the external light intensity into a correspondingly changing electrical signal. The element has an effective response capability to visible light and some near-ultraviolet and near-infrared light to ensure that the light intensity changes can be accurately sensed in complex daily lighting environments. The signal conditioning unit has a built-in amplifier circuit, which can amplify the weak electrical signal output by the light sensing element and increase the signal amplitude to a range that can be stably collected and identified in the subsequent period; it is equipped with a filter circuit, which uses a combination of capacitors and inductors to filter out high-frequency electromagnetic interference and low-frequency environmental clutter to ensure signal purity; it also has a level conversion circuit, which can adjust the signal voltage range to the range required by the ADC input in the microcontroller to ensure that the output analog electrical signal meets the subsequent processing standards.

[0025] Specifically, the microcontroller module includes: Signal acquisition unit: Based on the preset sampling frequency and the set timing, it establishes an electrical connection with the output end of the signal conditioning unit of the photosensitive sensor module, accurately collects the input analog electrical signal, and efficiently converts it into a digital coding form; Algorithm operation unit: stores and runs the first brightness adjustment algorithm program code, which is based on the light intensity digital data obtained by the signal acquisition unit, combined with the setting parameters pre-stored in the internal memory of the microcontroller, the setting parameters include the external light intensity is (Unit: lux), the screen brightness level is , The total number of preset brightness levels and the minimum light intensity threshold , the maximum light intensity threshold and brightness value array , and perform the calculation according to the following steps: First calculate the continuous brightness level , and then discretized into and (Special handling of edge cases); Finally, the interpolation formula Calculate the appropriate brightness level value and use it as an instruction to control the brightness of the LCD screen; Instruction sending unit: Packs and encodes brightness instructions according to SPI, I2C and other protocols via GPIO and sends them to the driver chip through the corresponding pins.

[0026] Specifically, the liquid crystal display screen and driver chip module include: Driver core unit: It can quickly disassemble and decode the brightness level control instructions received from the microcontroller via the communication protocol, and convert them into the underlying operation instruction set for the backlight source and pixel display control of the LCD screen. It can accurately calculate the current and voltage parameter values ​​of the driving backlight source or generate the duty cycle data of the corresponding pulse width modulation (PWM) waveform for different brightness levels, and coordinate the control of the driving timing, voltage polarity and other parameters closely related to the display of the pixel electrode of the LCD panel; Backlight adjustment unit: When the display screen uses cold cathode fluorescent lamp (CCFL) backlight, a high-precision current driver is used to strictly change the current flowing through the CCFL lamp according to instructions to increase or decrease the brightness; if an LED backlight is used, the built-in PWM controller is used to accurately adjust the PWM signal duty cycle, and the duty cycle change is used to change the proportion of the LED lamp bead's light emission time, thereby achieving multi-level smooth adjustment of the screen backlight brightness.

[0027] Exemplarily, the following parameters are set in the energy-saving LCD display control system: Light intensity threshold and level settings: Minimum light intensity threshold Lux (lux, a unit of light intensity) represents the lower limit of ambient light. Below this brightness, the screen brightness will be at a lower level to adapt to the dark environment and save energy.

[0028] Maximum light intensity threshold Lux means that when the ambient light reaches this intensity, the screen brightness will be adjusted to the highest level in the design to ensure visibility under strong light.

[0029] Total number of preset brightness levels , that is, the screen brightness can be smoothly switched between 10 different levels, corresponding to the change from darkest to brightest.

[0030] Brightness value array setting: Set the brightness value array , for the convenience of understanding and calculation, it is assumed here The stored relative brightness values ​​(range 0 - 1) are: (corresponding to the lowest brightness level, the relative brightness is only 10%), , , , , , , , , (Corresponding to the highest brightness level, full brightness, relative brightness 100%).

[0031] When the light sensor detects the external light intensity lux: First calculate the continuous brightness level : Next, determine the discrete brightness level associated values: Finally, the interpolation formula is used to calculate the final level used to adjust the screen brightness. : The screen brightness will be based on The corresponding actual brightness setting (such as the driver chip converting it into the appropriate current or voltage for the backlight source) lights up, which is in a relatively dim brightness state but meets the brightness requirements for visibility in low-light environments.

[0032] The same goes for other situations. When the light sensor detects that the external light intensity exceeds the maximum threshold, it is processed according to the maximum threshold.

[0033] Example 2 Outdoor advertising screens are widely distributed in public places such as city streets and squares. Traditional control methods only consider time or simple light adaptation, ignoring the interaction between pedestrians and screens. On the one hand, during periods or areas where no one is paying attention, the screen often maintains too high brightness, wasting energy; on the other hand, when pedestrians approach the content they want to watch, the brightness is not dynamically optimized, affecting the visual experience. Therefore, innovative means are urgently needed to integrate ambient light perception and human proximity sensing to achieve all-round intelligent brightness control.

[0034] This embodiment adds a human proximity sensor module to the basic architecture of the first embodiment, and cooperates with the second brightness adjustment algorithm to achieve intelligent brightness control that is more suitable for actual usage scenarios.

[0035] Specifically, it also includes a human proximity sensor module, which uses infrared, ultrasonic or microwave sensing principle sensors and is installed in a conspicuous and unobstructed position around the screen (such as the two corners below the screen, the sides of the frame, etc.), to monitor the distance between pedestrians and the screen in all directions, and output digital or analog distance signals to the microcontroller for detecting the distance between pedestrians and the LCD screen; The second brightness adjustment algorithm is used to further adjust the brightness of the LCD screen based on the distance between the pedestrian and the LCD screen on the basis of the first brightness adjustment algorithm.

[0036] Specifically, the distance between the person and the LCD screen includes a first threshold, a second threshold, a third threshold, and a fourth threshold; When a pedestrian approaches the display screen, he first reaches the first threshold, then reaches the second threshold, and then passes the LCD screen. When the pedestrian moves away from the display screen, he successively passes the third threshold and the fourth threshold.

[0037] Specifically, when the distance between the person and the liquid crystal display screen is outside the first threshold, the second threshold, the third threshold, and the fourth threshold, the result of the second brightness adjustment algorithm is the result of the first brightness adjustment algorithm minus a constant; When the distance between the person and the LCD screen is within a first threshold, and the brightness gradually increases from the first threshold to the second threshold; When the distance between the person and the liquid crystal display screen is between the second threshold and the third threshold, the brightness is constant; When the distance between the person and the LCD screen is in the range from the third threshold to the fourth threshold, the brightness decreases.

[0038] Specifically, the second brightness adjustment algorithm includes: Define the distance threshold between pedestrians and the LCD screen, and set the first threshold to The second threshold is The third threshold is The fourth threshold is (Unit: meter, reasonably calibrated according to screen size, installation height and other scene factors, such as small street screen , , , ; The value of large square screen increases accordingly).

[0039] When the distance between the pedestrian and the screen is outside the threshold ( or ), the second brightness adjustment algorithm output ( is the final brightness level, It is a predefined constant, determined by the initial energy consumption of the screen and the lower limit of visual comfort, to ensure energy saving without excessive dimming). Reduce the screen brightness to save energy.

[0040] When a pedestrian approaches from a long distance and enters the first threshold ( ) and approaches the second threshold ( ), the brightness gradually increases according to linear or nonlinear gradient rules (the linear slope can be set , ), attract attention and optimize visibility.

[0041] The pedestrian is in the range from the second threshold to the third threshold ( ), keep the current brightness constant ( ), stable display content is conducive to viewing.

[0042] After the pedestrian passes the screen, the distance from the third threshold to the fourth threshold ( ), the brightness decreases according to a linear or nonlinear rule (assuming the linear slope , ), return to energy-saving state.

[0043] Assume that this energy-saving LCD display is used in outdoor advertising scenarios on the street: 1. Threshold and constant setting Distance threshold: Based on the conventional installation height of the street advertising screen (assuming it is about 2.5 meters from the ground), screen size (assuming it is a rectangular screen 3 meters long and 2 meters high), pedestrian flow characteristics, expected interaction distance and other factors, after preliminary testing and empirical analysis, the distance threshold between the human body and the LCD screen is set. Set the first threshold meters, which means that when pedestrians approach within 3 meters of the screen, the screen begins to respond with brightness increase to attract attention; the second threshold meters. When pedestrians enter this distance, the screen brightness adjustment strategy will change. The third threshold meters (here we consider that the brightness of pedestrians passing by the screen should be kept stable), the fourth threshold When pedestrians are 3 meters away, the screen returns to the basic energy-saving brightness state.

[0044] Constant setting: Based on the initial energy consumption of the screen, the lower limit of visual comfort and the energy saving target, determine the constant subtracted by reducing the brightness outside the distance threshold (Here we assume that the brightness level range is 0 - 10, and the subtraction operation corresponds to reducing the brightness by two levels). The purpose is to save energy moderately when no one is paying close attention without affecting the basic screen recognition.

[0045] 2. Algorithm Examples in Different Scenarios No one is approaching (distance outside the threshold): Assume that at this moment, the distance between the pedestrian and the screen is rice( ), which is in energy-saving priority state. The basic brightness level calculated by the first brightness adjustment algorithm is assumed to be (corresponding to the brighter state to adapt to the ambient light at that time), according to the second brightness adjustment algorithm, the final brightness level , the screen brightness is reduced by two levels accordingly, reducing energy consumption and achieving energy-saving operation without affecting the approximate visibility at a long distance.

[0046] Pedestrians approaching (from the first threshold to the second threshold): When pedestrians gradually approach the screen, the distance between the pedestrians and the screen at this moment rice( ), let the linear slope of the process from the first threshold to the current position be (Indicates that the brightness level increases by 1 level for every 1 meter closer, which can be adjusted as needed), basic brightness level (determined by the first brightness adjustment algorithm based on current lighting and other environmental factors), the final brightness level , the screen brightness gradually increases, attracting pedestrians to focus on the screen content.

[0047] Pedestrians briefly stop in front of the screen (from the second threshold to the third threshold): Pedestrians stop, distance rice( ), basic brightness level (The result of the previous stage of approaching), according to the algorithm, the brightness in this interval is constant, so , maintaining a stable brightness so that pedestrians can clearly see the advertising information and avoid flickering or sudden changes that interfere with the viewing experience.

[0048] Pedestrians leave (from the third threshold to the fourth threshold): Pedestrians start to move away after watching. rice( ), let the linear slope (The brightness will be reduced by 2 levels for every 1 meter away, which can be optimized according to actual conditions), the basic brightness level, and the final brightness level The screen brightness slowly decreases and gradually returns to energy-saving mode as the pedestrians go away, completing the entire process of dynamic brightness control based on human proximity sensing, taking into account both display effect and energy-saving needs.

[0049] Example 3 A control method for an energy-saving liquid crystal display screen comprises the following steps: Detects external light intensity and outputs analog electrical signals. It is installed at a specific position on the LCD screen frame to accurately sense ambient light. Receive the analog signal and convert it, run the first brightness adjustment algorithm, and send a control instruction to the LCD driver chip according to the result; The backlight source of the LCD display is adjusted according to the microcontroller instructions to achieve multi-level smooth brightness adjustment.

[0050] Furthermore, infrared, ultrasonic or microwave induction principle sensors are used to monitor the distance between pedestrians and the screen in all directions, and output digital or analog distance signals to the microcontroller for detecting the distance between pedestrians and the LCD screen; The second brightness adjustment algorithm is used to further adjust the brightness of the LCD screen based on the distance between the pedestrian and the LCD screen on the basis of the first brightness adjustment algorithm.

[0051] Working principle of the present invention: When in use, the photosensitive sensor module is installed at a specific location on the screen frame to sense external light and convert it into an analog electrical signal, which is then processed and transmitted to the microcontroller. The microcontroller uses ADC to convert the sampled signal into a digital quantity, and runs the first brightness adjustment algorithm according to the preset threshold and parameters to calculate the basic brightness level. If a human approaches the sensor module, it will monitor the distance between the pedestrian and the screen, and according to the threshold setting, the brightness will be corrected in different intervals according to the corresponding rules (minus constant, gradual increase, constant, gradual decrease) through the second brightness adjustment algorithm. Finally, the microcontroller sends instructions to the display driver chip through GPIO according to the communication protocol according to the obtained brightness level. The driver chip controls the backlight source (adjusting the current or PWM duty cycle) and the LCD panel to achieve multi-level smooth brightness adjustment of the screen, taking into account energy saving and visual experience.

[0052] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0053] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A control system for an energy-saving liquid crystal display screen, characterized in that: include: The light sensor module is used to detect the external light intensity and output analog electrical signals. It is installed at a specific position on the LCD screen frame to accurately sense the ambient light. A microcontroller module is connected to the light sensor module to receive analog signals and convert and process them, run a first brightness adjustment algorithm, and send control instructions to a liquid crystal display driver chip according to the results; The LCD display and driver chip module adjusts the LCD display backlight source according to the microcontroller instructions to achieve multi-level smooth brightness adjustment.

2. The control system of an energy-saving liquid crystal display screen as claimed in claim 1, characterized in that: The light sensor module comprises: Light sensing element unit: using cadmium sulfide photoresistor, silicon-based photodiode or phototransistor, the light causes the carrier concentration to change and converts the light into an electrical signal; Signal conditioning unit: The amplifier amplifies weak signals, the filter circuit removes noise, and the level conversion circuit adjusts the voltage, so that the output analog electrical signal is suitable for subsequent processing.

3. The control system of an energy-saving liquid crystal display screen as claimed in claim 2, characterized in that: The microcontroller module comprises: Signal acquisition unit: Based on the preset sampling frequency and the set timing, it establishes an electrical connection with the output end of the signal conditioning unit of the photosensitive sensor module, accurately collects the input analog electrical signal, and efficiently converts it into a digital coding form; Algorithm operation unit: stores and runs the first brightness adjustment algorithm program code, which is based on the light intensity digital data obtained by the signal acquisition unit, combined with the setting parameters pre-stored in the internal memory of the microcontroller, the setting parameters include the external light intensity is , the screen brightness level is , The total number of preset brightness levels and the minimum light intensity threshold , the maximum light intensity threshold and brightness value array , and perform the calculation according to the following steps: First calculate the continuous brightness level , and then discretized into and ; Finally, the interpolation formula Calculate the appropriate brightness level value and use it as an instruction to control the brightness of the LCD screen; Instruction sending unit: packages the encoded brightness instructions and sends them to the driver chip through the corresponding pins.

4. The control system of an energy-saving liquid crystal display screen as claimed in claim 3, characterized in that: The liquid crystal display screen and driver chip module include: Driver core unit: converts the brightness level control instructions received from the microcontroller via the communication protocol into the underlying operation instruction set for the backlight source and pixel display control of the LCD display, calculates the current and voltage parameter values ​​of the backlight source for different brightness levels, or generates the duty cycle data of the corresponding pulse width modulation waveform, and coordinates the control of the driving timing, voltage polarity and display-related parameters of the pixel electrodes of the LCD panel; Backlight adjustment unit: When the display screen uses cold cathode fluorescent lamp backlight, a high-precision current driver is used to change the current flowing through the CCFL lamp to increase or decrease the brightness; if an LED backlight is used, the built-in PWM controller is used to adjust the PWM signal duty cycle, and the duty cycle change is used to change the proportion of the LED lamp bead's light emission time, thereby achieving multi-level smooth adjustment of the screen backlight brightness.

5. The control system of the energy-saving liquid crystal display screen according to claim 1, characterized in that: It also includes a human proximity sensor module, which uses infrared, ultrasonic or microwave sensing principle sensors to monitor the distance between pedestrians and the screen in all directions, and outputs digital or analog distance signals to the microcontroller for detecting the distance between pedestrians and the LCD screen; The second brightness adjustment algorithm is used to further adjust the brightness of the LCD screen based on the distance between the pedestrian and the LCD screen on the basis of the first brightness adjustment algorithm.

6. The control system of the energy-saving liquid crystal display screen according to claim 5, characterized in that: in, The distance between the person and the LCD screen includes a first threshold, a second threshold, a third threshold and a fourth threshold; When a pedestrian approaches the display screen, he first reaches the first threshold, then reaches the second threshold, and then passes the LCD screen. When the pedestrian moves away from the display screen, he successively passes the third threshold and the fourth threshold.

7. The control system of the energy-saving liquid crystal display screen according to claim 6, characterized in that: When the distance between the person and the liquid crystal display screen is outside the first threshold, the second threshold, the third threshold and the fourth threshold, the result of the second brightness adjustment algorithm is the result of the first brightness adjustment algorithm minus a constant; When the distance between the person and the LCD screen is within a first threshold, and the brightness gradually increases from the first threshold to the second threshold; When the distance between the person and the liquid crystal display screen is between the second threshold and the third threshold, the brightness is constant; When the distance between the person and the LCD screen is in the range from the third threshold to the fourth threshold, the brightness decreases.

8. The control system of the energy-saving liquid crystal display screen according to claim 7, characterized in that: The second brightness adjustment algorithm includes: Define the distance threshold between pedestrians and the LCD screen, and set the first threshold to The second threshold is The third threshold is The fourth threshold is ; When the distance between the pedestrian and the screen is outside the threshold, the second brightness adjustment algorithm outputs ; When a pedestrian approaches from a distance, enters the first threshold and approaches the second threshold, the brightness gradually increases according to the linear or nonlinear gradient rule. Set the linear slope , ; The pedestrian is in the range from the second threshold to the third threshold, keeping the current brightness constant ; After the pedestrian passes the screen, the brightness decreases from the third threshold to the fourth threshold according to a linear or nonlinear rule. When the brightness decreases according to a linear rule, the linear slope is set. ,but .

9. A control method for an energy-saving liquid crystal display screen, characterized in that: The following steps are involved: Detects external light intensity and outputs analog electrical signals. It is installed at a specific position on the LCD screen frame to accurately sense ambient light. Receive the analog signal and convert it, run the first brightness adjustment algorithm, and send a control instruction to the LCD driver chip according to the result; The backlight source of the LCD display is adjusted according to the microcontroller instructions to achieve multi-level smooth brightness adjustment.

10. The control method of the energy-saving liquid crystal display screen according to claim 9, characterized in that: Using infrared, ultrasonic or microwave induction principle sensors to monitor the distance between pedestrians and the screen in all directions, output digital or analog distance signals to the microcontroller to detect the distance between pedestrians and the LCD screen; The second brightness adjustment algorithm is used to further adjust the brightness of the liquid crystal display screen based on the first brightness adjustment algorithm and according to the distance between the pedestrian and the liquid crystal display screen.

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