A high-definition screen based on human body sensing

Abstract

The utility model relates to a high definition screen based on human body response belongs to display equipment technical field, including high definition screen frame and the arrangement in high definition screen frame inside a plurality of high definition screen module, the outside of high definition screen frame is arranged with a plurality of human body response components, still be provided with PWM generating circuit and the high definition screen module switch circuit that each high definition screen module corresponded to set in high definition screen frame inside, the output of human body response component is connected to the input of high definition screen module switch circuit through PWM generating circuit, the output of high definition screen module switch circuit is connected to the input of corresponding high definition screen module, the outside of high definition screen frame is arranged with a plurality of human body response components, can real -time sensing indoor personnel existence condition, when sensing no one, human body response component will signal transmission to PWM generating circuit through photo -coupler element, and then control high definition screen module switch circuit closes corresponding high definition screen module, makes it stop working, greatly reduced energy consumption.

Description

Technical Field

[0001] This utility model belongs to the field of display device technology, specifically relating to a high-definition screen based on human body sensing. Background Technology

[0002] With the increasing variety of indoor information display and interactive scenarios, indoor high-definition screens, as an important information presentation medium, are widely used in shopping malls, conference rooms, exhibition halls, and other venues. However, existing indoor high-definition screens face many problems that urgently need to be addressed in practical use.

[0003] Traditional indoor high-definition screens mostly operate in a continuously lit mode, maintaining high brightness regardless of whether anyone is present, resulting in significant energy waste. While some high-definition screens have simple timer functions, this timer control mode cannot dynamically adjust based on the actual activity of people in the room. For example, in a conference room, meetings may end early or start late, and the timer cannot respond promptly to people entering and leaving, causing the screen to remain lit even when no one is present, negatively impacting the user experience. Utility Model Content

[0004] The purpose of this utility model is to address the shortcomings of existing technologies where the screen maintains high brightness regardless of whether there are people indoors, resulting in a large amount of wasted power. The present invention provides a design for a high-definition screen based on human body sensing, including a high-definition screen frame and several high-definition screen modules arranged within the high-definition screen frame, with several human body sensing components arranged on the outside of the high-definition screen frame. The high-definition screen frame also includes a PWM generation circuit and a corresponding high-definition screen module switch circuit for each high-definition screen module; the output of the human body sensing component is connected to the input of the high-definition screen module switch circuit through the PWM generation circuit, and the output of the high-definition screen module switch circuit is connected to the input of the corresponding high-definition screen module.

[0005] Further improvements to this technical solution include a human body sensing component comprising a pyroelectric sensor RS1, an optocoupler U1, and a resistor R1. The first pin of the pyroelectric sensor RS1 is connected to a 9V power supply, the second pin of the pyroelectric sensor RS1 is grounded, the third and fourth pins of the pyroelectric sensor RS1 are connected to the first and second pins of the optocoupler U1, respectively, the third pin of the optocoupler U1 is connected to the PWM generation circuit through the resistor R1, and the fourth pin of the optocoupler U1 is connected to the PWM generation circuit.

[0006] Further improvements to this technical solution include the adoption of a BS612 pyroelectric infrared sensor for the human body as the pyroelectric sensor RS1.

[0007] A further improvement to this technical solution is that the optocoupler U1 adopts an optocoupler of model PC817.

[0008] Further improvements to this technical solution include a PWM generation circuit comprising a PWM generation chip U2, a resistor R2, a capacitor C1, a photoresistor R3, a capacitor C2, a capacitor C3, a field-effect transistor Q1, a field-effect transistor Q2, and a PWM output interface P1. The first pin of the PWM generator chip U2 is connected to the first terminal of resistor R2 and the first terminal of capacitor C1. The second terminal of resistor R2 is connected to the positive terminal of the power supply, and the second terminal of capacitor C1 is connected to the negative terminal of the power supply. The second pin of the PWM generator chip U2 is connected to the third pin of optocoupler U1 through resistor R1. The second pin of the PWM generator chip U2 is connected to the first terminal of photoresistor R3. The third pin of the PWM generator chip U2 is connected to the second terminal of photoresistor R3, the first terminal of capacitor C2, and the fourth pin of optocoupler U1. The fourth pin of the PWM generator chip U2 is connected to the second terminal of capacitor C2. All pins are connected to the negative terminal of the power supply. The fifth pin of the PWM generation chip U2 is connected to the gate of the field-effect transistor Q1. The drain of the field-effect transistor Q1 is connected to the negative terminal of the power supply. The source of the field-effect transistor Q1 is connected to the PWM output interface P1. The sixth pin of the PWM generation chip U2 is connected to the PWM output interface P1. The seventh pin of the PWM generation chip U2 is connected to the gate of the field-effect transistor Q2. The drain of the field-effect transistor Q2 is connected to the positive terminal of the power supply. The source of the field-effect transistor Q2 is connected to the PWM output interface P1. The eighth pin of the PWM generation chip U2 is connected to the PWM output interface P1 through capacitor C3. Further improvements to this technical solution include the use of an LLC resonant controller, model EG2153, in the PWM generation chip U2.

[0009] A further improvement to this technical solution is that the photoresistor R3 is a photoresistor of model LXD3526.

[0010] Further improvements to this technical solution include a high-definition screen module switching circuit comprising a current-limiting resistor and a switching transistor. The first end of the current-limiting resistor is connected to any pin of the PMW output interface P1, the second end of the current-limiting resistor R1 is connected to the base of the switching transistor, the emitter of the switching transistor is grounded, the collector of the switching transistor is connected to the first end of the corresponding high-definition screen module, and the second end of the high-definition screen module is connected to a 5V power supply.

[0011] The beneficial effects of this utility model are as follows: In this invention, several human body sensing components arranged on the outside of the high-definition screen frame can detect the presence of people indoors in real time. When no one is detected, the human body sensing components transmit the signal to the PWM generation circuit through an optocoupler (a PC817 optocoupler), which in turn controls the high-definition screen module switching circuit to shut down the corresponding high-definition screen module, causing it to stop working and avoiding unnecessary power consumption, thus greatly reducing energy consumption.

[0012] This invention employs a photoresistor R3 of model LXD3526, which can sense changes in indoor ambient light intensity. When the ambient light intensity changes, the resistance of the photoresistor changes accordingly, thereby affecting the parameters of the PWM signal generated by the PWM generation circuit. This allows the high-definition screen module to automatically adjust its brightness according to ambient light conditions, providing a clear and comfortable display effect under different indoor lighting environments, thus enhancing the high-definition screen's adaptability to the environment.

[0013] The high-definition screen module switching circuit consists of a current-limiting resistor and a switching transistor. The current-limiting resistor can limit the current flowing into the switching transistor and protect the transistor from being damaged by excessive current. The switching transistor, based on the signal from the PWM output interface, quickly and accurately controls the on / off state of the corresponding high-definition screen module, thereby achieving reliable control of the high-definition screen module.

[0014] Furthermore, the design principle of this utility model is reliable, the structure is simple, and it has a very wide range of application prospects.

[0015] It is evident that this utility model has outstanding substantive features and significant progress compared with the prior art, and the beneficial effects of its implementation are also obvious. Attached Figure Description

[0016] To more clearly illustrate the technical solution of this utility model, the drawings used in the description will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a PWM generation circuit.

[0018] Figure 2 This is a schematic diagram of the switching circuit for a high-definition screen module. Detailed Implementation

[0019] To make the objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0021] like Figure 1 and Figure 2 As shown, this utility model provides a high-definition screen based on human body sensing, including a high-definition screen frame and a plurality of high-definition screen modules arranged within the high-definition screen frame. A plurality of human body sensing components are arranged on the outer side of the high-definition screen frame. The high-definition screen frame is also provided with a PWM (Pulse Width Modulation) generation circuit and a high-definition screen module switching circuit corresponding to each high-definition screen module. The output terminal of the human body sensing component is connected to the input terminal of the high-definition screen module switching circuit through the PWM generation circuit, and the output terminal of the high-definition screen module switching circuit is connected to the input terminal of the corresponding high-definition screen module.

[0022] Specifically, the human body sensing component includes a pyroelectric sensor RS1, an optocoupler U1, and a resistor R1. The first pin of the pyroelectric sensor RS1 is connected to a 9V power supply, the second pin of the pyroelectric sensor RS1 is grounded, the third and fourth pins of the pyroelectric sensor RS1 are connected to the first and second pins of the optocoupler U1, respectively, the third pin of the optocoupler U1 is connected to the PWM generation circuit through the resistor R1, and the fourth pin of the optocoupler U1 is connected to the PWM generation circuit.

[0023] Among them, the pyroelectric sensor RS1 adopts the BS612 human pyroelectric infrared sensor, and the optocoupler U1 adopts the PC817 optocoupler.

[0024] The RS1 pyroelectric sensor uses the BS612 pyroelectric infrared human body sensor, which has the following advantages: First, the sensing distance is adapted to indoor scene requirements, with an effective sensing distance of 3 to 8 meters, which can cover the common range of people's activities in front of indoor high-definition screens such as shopping mall guide screens and conference room large screens, avoiding the problem of people not being detected when they are close due to the sensing distance being too short, or people being falsely detected when they are outdoors due to the sensing distance being too long; Second, the sensing angle is 110° to 120°, which, together with the arrangement of multiple components on the outside of the high-definition screen frame, such as one component every 60cm along the horizontal direction of the frame, can achieve no dead angle coverage of the area in front of the screen.

[0025] The optocoupler U1 uses a PC817 optocoupler, a single-channel linear optocoupler. Its input side (pins 1 and 2) and output side (pins 3 and 4) are opto-isolated, effectively blocking electrical interference between the human body sensing component and the PWM generation circuit. Specifically, its input current range is 5 to 20 mA, matching the output current of the BS612 pyroelectric sensor (typically 8 mA), eliminating the need for an additional current amplification circuit. The maximum collector current on the output side is 50 mA, meeting the current requirements of the subsequent PWM generation circuit and ensuring no signal attenuation or distortion during transmission.

[0026] When the output side (third pin) of optocoupler U1 is connected to the PWM generation circuit, the current flowing into the second pin of PWM generation chip U2 (model EG2153) needs to be limited. The resistor R1 can prevent the chip from being damaged by excessive current.

[0027] Power Supply Connection: The first pin of the pyroelectric sensor RS1 is connected to the positive terminal of a 9V DC power supply via a 0.5mm² copper core wire to ensure stable current transmission. The second pin is connected to the negative terminal (ground) of the power supply via a wire of the same specification, forming a complete power supply loop. To prevent power fluctuations from affecting the sensor, an electrolytic capacitor is connected in series between the 9V power supply and the first pin of the pyroelectric sensor for filtering and voltage regulation. The capacitor is placed close to the sensor pin to reduce the impact of wire impedance on the filtering effect.

[0028] Sensor and optocoupler connection: The third pin (signal output) of the pyroelectric sensor RS1 is directly connected to the first pin (input-side anode) of the optocoupler U1 via a wire, and the fourth pin (signal ground) is directly connected to the second pin (input-side cathode) of the optocoupler U1. This connection method ensures that the personnel sensing signal output by the sensor (high level is 5V, low level is 0V) is completely transmitted to the input side of the optocoupler. A shielded wire with a cross-sectional area of ​​0.3mm² is used, with one end of the shield grounded to avoid the influence of indoor electromagnetic interference (such as motor equipment in shopping malls or wireless equipment in conference rooms) on the signal.

[0029] Connection between optocoupler and PWM generation circuit: The third pin (output-side collector) of optocoupler U1 is connected to the second pin of PWM generation chip U2 in the PWM generation circuit through resistor R1. The third pin and resistor R1 are fixed by soldering. The solder joint needs to be tin-plated to prevent oxidation and poor contact. The fourth pin (output-side emitter) of optocoupler U1 is directly connected to the third pin of PWM generation chip U2 through a wire. At the same time, this pin is connected to the negative power supply of the PWM generation circuit (grounded through capacitor C2) to ensure uniform grounding on the output side and avoid signal distortion caused by potential difference.

[0030] When a person enters the sensing range of the pyroelectric sensor RS1, the sensor detects the infrared signal emitted by the human body. The internal sensing element generates a charge change, which is processed by the internal amplification circuit and outputs a high-level signal (5V) from the third pin. This high-level signal is input between the first and second pins of the optocoupler U1, causing the light-emitting diode on the input side of the optocoupler to conduct and emit light. The phototransistor on the output side of the optocoupler conducts after receiving the light signal. At this time, a path is formed between the third and fourth pins of the optocoupler. The second pin of the PWM generation chip U2 obtains a low-level signal (close to 0V) through resistor R1, the third pin, and the fourth pin of the optocoupler. This signal serves as a trigger signal for the presence of a person and is transmitted to the PWM generation circuit.

[0031] When a person leaves the sensing range, the third pin of the pyroelectric sensor RS1 outputs a low-level signal (0V), the LED on the input side of the optocoupler turns off, and the phototransistor on the output side is cut off. The second pin of the PWM generation chip U2 receives the power supply voltage (5V) from the PWM generation circuit side through resistor R1, forming a signal indicating the absence of a person, triggering subsequent circuits to shut down the corresponding high-definition screen module. Throughout the signal transmission process, the isolation effect of the optocoupler U1 effectively avoids crosstalk between the 9V power supply on the human body sensing component side and the 5V power supply on the PWM generation circuit side, ensuring the stability of signal transmission.

[0032] The human body sensing component and the PWM generation circuit are connected by an optocoupler. The optocoupler has good electrical isolation performance, which can effectively isolate the electrical signals on the human body sensing component side and the PWM generation circuit side, prevent the input of interference signals, ensure the stability and reliability of signal transmission, and ensure that the switching circuit of the high-definition screen module can accurately receive the control signal, thereby realizing stable control of the high-definition screen module.

[0033] Additionally, the PWM generation circuit includes a PWM generation chip U2, resistor R2, capacitor C1, photoresistor R3, capacitor C2, capacitor C3, MOSFET Q1, MOSFET Q2, and PWM output interface P1. The first pin of the PWM generation chip U2 is connected to the first terminal of resistor R2 and capacitor C1. The second terminal of resistor R2 is connected to the positive terminal of the power supply, and the second terminal of capacitor C1 is connected to the negative terminal of the power supply. The second pin of the PWM generation chip U2 is connected to the third pin of optocoupler U1 through resistor R1. The second pin of the PWM generation chip U2 is also connected to the first terminal of photoresistor R3. The third pin of the PWM generation chip U2 is connected to the second terminal of photoresistor R3 and the first terminal of capacitor C2. The fourth pin of the optocoupler U1, the fourth pin of the PWM generator chip U2, and the second terminal of capacitor C2 are all connected to the negative terminal of the power supply. The fifth pin of the PWM generator chip U2 is connected to the gate of the field-effect transistor Q1. The drain of the field-effect transistor Q1 is connected to the negative terminal of the power supply. The source of the field-effect transistor Q1 is connected to the PWM output interface P1. The sixth pin of the PWM generator chip U2 is connected to the PWM output interface P1. The seventh pin of the PWM generator chip U2 is connected to the gate of the field-effect transistor Q2. The drain of the field-effect transistor Q2 is connected to the positive terminal of the power supply. The source of the field-effect transistor Q2 is connected to the PWM output interface P1. The eighth pin of the PWM generator chip U2 is connected to the PWM output interface P1 through capacitor C3. Among them, the PWM generation chip U2 adopts an LLC resonant controller of model EG2153, and the photoresistor R3 adopts a photoresistor of model LXD3526.

[0034] The PWM generation chip U2 uses the EG2153 LLC resonant controller, which is an 8-pin DIP (Dual In-line Package) package, suitable for the circuit installation space of indoor high-definition screens (the reserved circuit mounting cavity size within the high-definition screen frame is 10cm × 8cm × 3cm; the DIP package can be fixed to the PCB (Printed Circuit Board) via insertion, facilitating wiring and maintenance). Its core parameters and compatibility with this solution are as follows: The operating voltage range is 8 to 20V. This solution selects a 12V DC power supply to power it, which not only meets the normal operation requirements of the chip, but also avoids the chip overheating caused by high voltage. The built-in PWM signal generator has an adjustable output frequency range of 20kHz to 200kHz. For the brightness adjustment requirements of high-definition screen modules, the base frequency is set to 50kHz. The duty cycle can be adjusted from 10% to 90% through external components to meet the brightness adaptation under different lighting conditions.

[0035] The photoresistor R3 is an LXD3526 type photoresistor, whose resistance changes with light intensity, making it suitable for indoor environments. When the light intensity is 10 lux (low indoor light, such as a conference room with the lights off in the evening), the resistance is approximately 10 kΩ; when the light intensity is 1000 lux (strong indoor light, such as a shopping mall with the windows open during the day), the resistance is approximately 1 kΩ. The resistance variation range can accurately reflect the difference in indoor light intensity, providing a stable parameter basis for PWM signal duty cycle adjustment. The dimensions are 5mm×5mm×2mm, which can be directly soldered onto the PCB board, occupying little space and adapting to the circuit layout within the high-definition screen frame.

[0036] Resistor R2 is a metal film resistor, and capacitor C1 is an electrolytic capacitor. The two form an RC filter circuit, which is connected between the positive terminal of the 12V power supply and the first pin of chip U2: Resistor R2 limits the charging current of capacitor C1 to prevent current surges from damaging the chip; capacitor C1 filters out high-frequency noise in the power supply to ensure that the voltage input to chip U2 is stable within the range of 12V±0.5V, and prevents power fluctuations from causing PWM signal frequency drift.

[0037] Capacitor C2 (signal filter capacitor) is a ceramic capacitor connected between the third pin of chip U2 and the negative terminal of the power supply. It is used to filter out high-frequency interference in the output signal of photoresistor R3, such as the flicker signal of indoor LED lights and electromagnetic interference from wireless devices, to ensure that the light sensing signal input to chip U2 is smooth and to avoid frequent fluctuations in the duty cycle of the PWM signal.

[0038] Capacitor C3 (output coupling capacitor) is a ceramic capacitor connected between pin 8 of chip U2 and PMW output interface P1. Its function is to isolate the DC component in the PWM signal and output only the AC PWM control signal, preventing DC voltage from flowing into the high-definition screen module switching circuit and avoiding false turn-on of the switching transistor due to DC bias.

[0039] Field-effect transistors Q1 and Q2 form a push-pull amplifier circuit, connected between pins 5 and 7 of chip U2 and the PWM output interface P1. When pin 5 of chip U2 outputs a low level, Q1 is turned on, pulling the PWM output interface P1 down to the negative terminal of the power supply (0V). When pin 7 outputs a high level, Q2 is turned on, pulling the PWM output interface P1 up to the positive terminal of the power supply (12V). By alternately turning on and off Q1 and Q2, the driving capability of the PWM signal is amplified (output current can reach 500mA), meeting the base drive current requirement of the switching transistor in the high-definition screen module switching circuit (typical value 10mA), and avoiding insufficient conduction of the switching transistor due to insufficient drive.

[0040] Initial state (no people and low light): When there are no people, the optocoupler U1 in the human body sensing component is cut off, and the second pin of the chip U2 receives the power supply voltage (12V) through the photoresistor R3. At this time, if the indoor light is weak (10 lux), the resistance of R3 is 10kΩ, and the voltage difference between the second and third pins of the chip U2 is 6V (according to the voltage divider principle). That is, the high-definition screen is in a state of no people and weak light, the duty cycle of the PWM signal output is 0% (that is, the PWM output interface P1 continuously outputs 0V), the high-definition screen module switching circuit is cut off, and the module is turned off.

[0041] People are present and there is strong light: When there are people present, optocoupler U1 is turned on, and the second pin of chip U2 is pulled low to 0.3V (optocoupler conduction voltage drop). If the indoor light is strong (1000 lux), the resistance of R3 is 1kΩ, and the voltage difference between the second and third pins of chip U2 is 0.3V, meaning the HD screen is in a state of strong light with people present: the built-in PWM generator of chip U2 starts, generating a PWM signal with a frequency of 50kHz and a duty cycle of 90% (high level 12V for 0.018ms, low level 0V for 0.002ms); when the fifth pin of chip U2 outputs a low level, Q1 is turned on, and pin 1 of P1 is pulled to 0V; when the seventh pin outputs a high level, Q2 is turned on, and pin 1 of P1 is pulled to 12V; after push-pull amplification, the PWM signal driving capability is increased to 500mA, and it is output to the HD screen module switching circuit through P1, controlling the switching transistor to conduct for 90% of the time, and the HD screen module displays at high brightness.

[0042] People are present and the light is dim: When there are people present but the indoor light is dim, the resistance of R3 is 10kΩ, and the voltage difference between the second and third pins of chip U2 is 0.3V (optocoupler is on). This means that when the HD screen is in a dimly lit environment with people present, the duty cycle of the PWM signal is automatically adjusted to 30% (high level 12V for 0.006ms, low level 0V for 0.014ms). After being amplified by Q1 / Q2, the signal is output to the switching circuit, which controls the module to display at low brightness, ensuring clear viewing while avoiding glare from strong light.

[0043] Personnel departure: After the personnel leave, optocoupler U1 is cut off, and the second pin of chip U2 returns to 12V voltage. Regardless of the light intensity, i.e., when the high-definition screen is in a state where no one is present, the duty cycle of the PWM signal immediately drops to 0%, the module is turned off, and energy consumption stops.

[0044] Chip U2 is equipped with a storage module, which stores the PWM signal corresponding to the photoresistor R3 blocking. That is, it stores the PWM signal corresponding to the voltage difference between the second and third pins of chip U2. Different voltage differences result in different output PWM signals.

[0045] The photoresistor in the PWM generation circuit senses changes in indoor ambient light intensity. Depending on the light intensity, the resistance of the photoresistor changes accordingly, affecting the parameters of the PWM signal generated by the PWM generation circuit. This allows the high-definition screen module's switching circuit to automatically adjust the brightness of the high-definition screen module based on ambient light conditions, ensuring a clear and comfortable display under different lighting environments and enhancing the high-definition screen's adaptability to various indoor environments.

[0046] Furthermore, the high-definition screen module switching circuit includes a current-limiting resistor and a switching transistor. The first end of the current-limiting resistor is connected to any pin of the PMW output interface P1, the second end of the current-limiting resistor R1 is connected to the base of the switching transistor, the emitter of the switching transistor is grounded, the collector of the switching transistor is connected to the first end of the corresponding high-definition screen module, and the second end of the high-definition screen module is connected to a 5V power supply.

[0047] Module activation and brightness adjustment (with PWM control signal): When the PWM generation circuit detects that there are people indoors and the corresponding high-definition screen module needs to be turned on, it outputs a periodic PWM control signal (frequency 50kHz, duty cycle adjustable from 10% to 90%) through the PWM output interface P1: When the PWM signal is high (12V), the current flows into the base of the switching transistor through the current limiting resistor, the transistor is saturated and conducting, and the voltage drop between the collector and emitter is about 0.2V. The high-definition screen module obtains 5V power supply through the transistor (5V power supply positive terminal → module → transistor collector → emitter → ground), and the module lights up. When the PWM signal is low (0V), no current flows into the base, the transistor is cut off, the module power supply circuit is disconnected, and the module is turned off. By adjusting the duty cycle of the PWM signal (the proportion of the high-level duration to the cycle), the average power supply time of the module can be changed: the higher the duty cycle, the longer the average power supply time and the higher the module brightness; the lower the duty cycle, the shorter the average power supply time and the lower the module brightness, thus achieving precise brightness adjustment.

[0048] Module off (no PWM control signal): When the PWM generation circuit detects that there are no people in the room, the PWM output interface P1 continuously outputs a low level (0V), the base of the switching transistor has no current and is always in the off state, the power supply circuit of the high-definition screen module is disconnected, the module remains in the off state, and only consumes the standby power consumption of 5V power supply (about 0.1W), which greatly reduces the ineffective energy consumption.

[0049] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-definition screen based on human body sensing, characterized in that, It includes a high-definition screen frame and several high-definition screen modules arranged within the high-definition screen frame, and several human body sensing components are arranged on the outside of the high-definition screen frame. The high-definition screen frame also includes a PWM generation circuit and a corresponding high-definition screen module switch circuit for each high-definition screen module; the output of the human body sensing component is connected to the input of the high-definition screen module switch circuit through the PWM generation circuit, and the output of the high-definition screen module switch circuit is connected to the input of the corresponding high-definition screen module.

2. The high-definition screen based on human body sensing according to claim 1, characterized in that, The human body sensing component includes a pyroelectric sensor RS1, an optocoupler U1, and a resistor R1. The first pin of the pyroelectric sensor RS1 is connected to a 9V power supply, the second pin of the pyroelectric sensor RS1 is grounded, the third and fourth pins of the pyroelectric sensor RS1 are connected to the first and second pins of the optocoupler U1, respectively. The third pin of the optocoupler U1 is connected to the PWM generation circuit through the resistor R1, and the fourth pin of the optocoupler U1 is connected to the PWM generation circuit.

3. The high-definition screen based on human body sensing according to claim 2, characterized in that, The RS1 pyroelectric sensor is a BS612 human body pyroelectric infrared sensor.

4. The high-definition screen based on human body sensing according to claim 2, characterized in that, The optocoupler U1 is a PC817 optocoupler.

5. The high-definition screen based on human body sensing according to claim 2, characterized in that, The PWM generation circuit includes a PWM generation chip U2, a resistor R2, a capacitor C1, a photoresistor R3, a capacitor C2, a capacitor C3, a field-effect transistor Q1, a field-effect transistor Q2, and a PWM output interface P1; The first pin of the PWM generator chip U2 is connected to the first terminal of resistor R2 and the first terminal of capacitor C1. The second terminal of resistor R2 is connected to the positive terminal of the power supply, and the second terminal of capacitor C1 is connected to the negative terminal of the power supply. The second pin of the PWM generator chip U2 is connected to the third pin of optocoupler U1 through resistor R1. The second pin of the PWM generator chip U2 is connected to the first terminal of photoresistor R3. The third pin of the PWM generator chip U2 is connected to the second terminal of photoresistor R3, the first terminal of capacitor C2, and the fourth pin of optocoupler U1. The fourth pin of the PWM generator chip U2 is connected to the second terminal of capacitor C2. All pins are connected to the negative terminal of the power supply. The fifth pin of the PWM generation chip U2 is connected to the gate of the field-effect transistor Q1. The drain of the field-effect transistor Q1 is connected to the negative terminal of the power supply. The source of the field-effect transistor Q1 is connected to the PWM output interface P1. The sixth pin of the PWM generation chip U2 is connected to the PWM output interface P1. The seventh pin of the PWM generation chip U2 is connected to the gate of the field-effect transistor Q2. The drain of the field-effect transistor Q2 is connected to the positive terminal of the power supply. The source of the field-effect transistor Q2 is connected to the PWM output interface P1. The eighth pin of the PWM generation chip U2 is connected to the PWM output interface P1 through capacitor C3.

6. The high-definition screen based on human body sensing according to claim 5, characterized in that, The PWM generation chip U2 uses an LLC resonant controller with model number EG2153.

7. The high-definition screen based on human body sensing according to claim 5, characterized in that, The photoresistor R3 is a model LXD3526 photoresistor.

8. The high-definition screen based on human body sensing according to claim 5, characterized in that, The high-definition screen module switching circuit includes a current-limiting resistor and a switching transistor. The first end of the current-limiting resistor is connected to any pin of the PMW output interface P1. The second end of the current-limiting resistor R1 is connected to the base of the switching transistor. The emitter of the switching transistor is grounded. The collector of the switching transistor is connected to the first end of the corresponding high-definition screen module. The second end of the high-definition screen module is connected to a 5V power supply.

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