CN214476338U

CN214476338U - LED large screen display system and display screen

Info

Publication number: CN214476338U
Application number: CN202120740355.XU
Authority: CN
Inventors: 王云霄; 张永玲; 王亮
Original assignee: System Integration Co Ltd
Current assignee: System Integration Co Ltd
Priority date: 2021-04-12
Filing date: 2021-04-12
Publication date: 2021-10-22
Anticipated expiration: 2031-04-12

Abstract

The utility model discloses a LED large screen display system and display screen belongs to display screen technical field, and its technical scheme main points include signal source input device, video processor, wireless transmitter, wireless receiver, microcontroller, switch module, display screen module, surge protection circuit and power conversion module. The utility model discloses circuit design is simple, with low costs, can reach the luminosity of self-adaptation regulation LED display screen, and can use for a long time in the open air and be difficult for receiving the damage.

Description

LED large screen display system and display screen

Technical Field

The utility model belongs to the technical field of the display screen, more specifically say that it relates to a LED large screen display system and display screen that says so.

Background

With the application of the LED display screen becoming more and more extensive, the market of the LED display screen becomes larger and wider, the application becomes more and more extensive, and more LED display screen manufacturers exist. The most important LED display screen control system in the LED display frequency technology is a system for controlling an LED large screen to display correctly according to the requirements of users.

However, during use, problems with LED displays are also increasingly exposed:

1. according to empirical data, the maximum-to-minimum ratio of the luminous intensity in the same batch of LED chips under the same driving condition can be more than 200%, and the maximum-to-minimum ratio of the luminous intensity is still about 35% after 1:1.2 spectral screening. Moreover, the aging speed of the LEDs with different colors is different, and the luminance of the LEDs under the same driving is also different.

2. The LED large display screen is commonly used for outdoor display, so that under the influence of external environment (such as lightning strike), various surge signals can be invaded by a power grid system, and the surge can cause the damage of the LED in the LED large display screen.

In the prior art, the dimming circuit is complex in design and cannot adapt to outdoor use environment simultaneously. If the authorized bulletin number is CNU201355533Y, an LED display box, an LED display screen and an LED display system are disclosed, at least one identification unit is arranged on the LED display screen box to identify the parameters of the LED light-emitting diode, and various parameters of the LED provided by an LED manufacturer are identified on each LED display screen box through the identification unit and stored in a storage, so that when the LED display screen is assembled, the LED display screen boxes with the consistent performance parameters form the same display screen, and the display performance of the formed LED display screen is consistent. Therefore, the luminosity of the LED display screen cannot be adjusted in a self-adaptive mode, the method of identification is too complicated, the result cannot be guaranteed, and the LED display screen cannot be suitable for adapting to the outdoor environment for a long time.

Therefore, an LED screen display system which can automatically adjust the luminosity of the LED display screen and can enable the LED display screen to be suitable for the outdoor environment for a long time is needed to be solved.

SUMMERY OF THE UTILITY MODEL

To the luminosity of the unable self-adaptation regulation LED display screen that exists among the prior art, can't be suitable for technical problem such as outdoor environment for a long time, the utility model provides a LED screen display system to solve prior art problem.

A first aspect of the present invention provides a LED screen display system, including signal source input device, a video processor, a line transmitter, a wireless receiver, a microcontroller, a switch module, a display screen module, a surge protection circuit and a power conversion module, the signal source input device is connected to the input of the video processor, the output of the video processor is connected to the wireless transmitter, the wireless transmitter transmits signals to the wireless receiver, the output of the wireless receiver is connected to the input of the microcontroller, the output of the microcontroller is connected to the input of the switch module, and then the luminosity and the chromaticity of the display screen module are respectively adjusted;

the power conversion module is connected with the surge protection circuit in series and then is connected to the display screen module, the surge protection circuit comprises a thermistor, a first capacitor and a bleeder resistor, the thermistor is coupled to the display screen module after being connected with the power conversion module, the input end of the first capacitor is connected to the output end of the thermistor, the output end of the first capacitor is grounded, and the bleeder resistor is connected to the two ends of the first capacitor in parallel.

The signal source input device, the wireless transmitter, the wireless receiver, the microcontroller and the display screen system are arranged, so that the LED large screen can be controlled to display correctly according to the requirements of a user, namely, the signal source input device can be utilized to control terminals such as the LED large screen. The microcontroller is externally connected with the switch module and then connected with the display screen module, and the purpose is to control the luminosity of the display screen module by utilizing the PWM wave output by the microcontroller to control the on-off frequency of the switch module, so that the luminosity and the chromaticity of the display screen are adjusted in real time during working, and the optimal display effect is achieved. The surge protection circuit can prevent the LED in the display screen from being damaged due to the fact that large surge current is generated instantly when power is on or the LED display screen is installed outdoors and is easily affected by external environment factors, and therefore the surge protection circuit can play a good protection role.

Furthermore, the thermistor comprises a negative temperature coefficient thermistor and a positive temperature coefficient thermistor, and the negative temperature coefficient thermistor and the positive temperature coefficient thermistor are coupled to two ends of the power conversion module and the display screen module after being connected in series. In engineering application, the LED has weak capability of resisting surge current and reverse voltage, the negative temperature coefficient thermistor NTC can inhibit the sudden change of current, and the positive temperature coefficient thermistor PCT automatically regulates the current to finally keep the current in a specific range.

Further, the switch module comprises a triode, a divider resistor and a pull-down resistor, the microcontroller comprises a PWM signal interface, the PWM signal interface is connected with the input end of the divider resistor, the output end of the divider resistor is connected with the base electrode of the triode, the collector electrode of the triode is connected with the display screen module, and the emitter electrode of the triode is connected with the pull-down resistor. The light intensity detection module is arranged to feed back the light intensity of each LED array in real time, and the light intensity signal is fed back to the microcontroller, and the microcontroller compares the light intensity signal with a preset standard range value to judge whether the luminosity and the chromaticity of the LED array need to be adjusted. The characteristic that the output voltage of the photoresistor is different due to different resistance values of the photoresistor in different light intensities is utilized, the output voltage of the photoresistor is acquired after voltage division is carried out on the photoresistor and the pull-up resistor, and then the analog signal is converted into a digital signal through the AD acquisition device to be compared and calculated by the microcontroller.

Furthermore, the output ends of the red light LED array, the green light LED array and the blue light LED array in the display screen module are respectively and independently connected with a group of switch modules. The microcontroller sends a logic signal to control the on and off of the switching triode in a period, namely the PWM wave occupies the duty ratio of the period of the on time in the period to quickly adjust the luminosity and the chromaticity of the display screen module.

Furthermore, the display screen module comprises a red LED array, a green LED array, a blue LED array and at least three light intensity detection modules, wherein each light intensity detection module respectively detects the light intensity of the red LED array, the green LED array and the blue LED array and transmits a light intensity signal to the data interface of the microcontroller. This enables the red, green and blue LED arrays to be individually controlled to adjust their luminosity and chromaticity.

Furthermore, the light intensity detection module comprises a photoresistor, a pull-up resistor and an AD collector, the photoresistor is connected with the pull-up resistor in series, and a voltage output end of the photoresistor is connected to the AD collector and further connected to a data interface of the microcontroller. Because the LED in the display module supplies power for direct current, the input power supply is generally commercial power, an AC/DC converter is required to convert alternating current into direct current, and then the DC/DC converter is used for voltage conversion according to working voltage.

Further, the power conversion module comprises an input power supply, an AC/DC converter and a DC/DC converter, wherein the input power supply is connected to the input end of the AC/DC converter, the output end of the AC/DC converter is connected to the input end of the DC/DC converter, and the output end of the DC/DC converter is connected with the DC/DC converter.

Furthermore, the AC/DC converter comprises a fuse, a rectifier bridge and a transient voltage suppressor, wherein the fuse is connected with the input power supply in series, and the transient voltage suppressor is connected to the rectifier bridge after being connected to two ends of the input power supply in parallel. The transient voltage suppressor can prevent voltage overload, and the fuse plays a role in overheat protection.

Furthermore, the input power supply is 380V alternating current, and the AC/DC converter is a converter converting 380V to 220V.

A second aspect of the present invention provides a display screen, including the LED screen display system provided above.

It is right from the above-mentioned the utility model discloses a description can know, the utility model discloses a LED screen display system and display screen have following advantage:

1. the microcontroller is externally connected with the switch module and then connected with the display screen module, so that the luminance of the display screen module can be controlled by the on-off frequency of the PWM wave control switch module output by the microcontroller, and the luminance of the display screen can be adjusted in real time when the display screen works, so that the optimal display effect is achieved;

2. by arranging the surge protection circuit, the phenomenon that a large surge current is generated at the moment of electrifying can be prevented, and the LED display screen is prevented from being damaged by external environmental factors when being arranged outdoors;

3. the utility model provides a circuit design of LED display screen system and display screen is simple, with low costs, can reach the luminosity of self-adaptation regulation LED display screen, and can use for a long time in the open air and be difficult for receiving the damage.

Drawings

The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and together with the description serve to explain the principles of the invention. Other embodiments and many of the intended advantages of embodiments will be readily appreciated as they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

FIG. 1 is a functional block diagram of one embodiment of an LED screen display system and display screen;

FIG. 2 is a schematic block diagram of the luminosity adjustment of one embodiment of an LED screen display system and display screen;

FIG. 3 is a circuit diagram of a surge protection circuit and luminance adjustment for one embodiment of an LED screen display system and display screen;

FIG. 4 is a detailed circuit diagram of the luminosity detection module of one embodiment of the LED screen display system and display screen.

Reference numerals: 100-signal source input device; 200-a video processor; 300-a wireless transmitter; 400-a wireless receiver; 500-a microcontroller; 1-PWM1 signal output port; 2-PWM2 signal output port; 3-PWM3 signal output port; 4-a data interface; 600-a switch module; 700-display screen module; 701-red LED array; 702-an array of green LEDs; 703-an array of blue LEDs; 704-red light intensity detection module; 7041-AD collector; 705-green light intensity detection module; 706-blue light intensity detection module; 800-surge protection circuit; 900-power conversion module; 901-AC/DC converter; 902-DC/DC converter; NTC1/NTC2/NTC 3-negative temperature coefficient thermistor; PTC1/PTC2/PTC 3-positive temperature coefficient thermistor; C1/C2/C3-first capacitance; R1/R2/R3-bleeder resistor; a Q1/Q2/Q3-triode; R4/R5/R6-pull-down resistor; R7/R8/R9-voltage dividing resistor; r10-pull-up resistor; CDS-photoresistor.

Detailed Description

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as "top," "bottom," "left," "right," "up," "down," etc., is used with reference to the orientation of the figures being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and logical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

Referring to fig. 1, an LED screen display system includes a signal source input device 100, a video processor 200, a line transmitter, a wireless receiver 400, a microcontroller 500, a switch module 600, a display screen module 700, a surge protection circuit 800 and a power conversion module 900, wherein the signal source input device 100 is connected to an input end of the video processor 200, an output end of the video processor 200 is connected to the wireless transmitter 300, the wireless transmitter 300 transmits a signal to the wireless receiver 400, an output end of the wireless receiver 400 is connected to an input end of the microcontroller 500, and an output end of the microcontroller 500 is connected to an input end of the switch module 600, so as to adjust luminosity and chromaticity of the display screen module 700 respectively; the power conversion module 900 is connected in series with the surge protection circuit 800, and is further connected to the display screen module 700.

The signal source input device 100, the wireless transmitter 300, the wireless receiver 400, the microcontroller 500 and the display screen system are arranged to control the large LED screen to display correctly according to the user's requirement, that is, the signal source input device 100 can be used to control terminals such as the large LED screen.

Referring to fig. 2, the microcontroller 500 is externally connected to the switch module 600 and further connected to the display screen module 700, and includes a PWM1 signal output terminal 1, a PWM2 signal output terminal 2, a PWM3 signal output terminal and a data port 4, so as to control the luminosity of the display screen module 700 by controlling the on-off frequency of the switch module 600 using the PWM wave output by the microcontroller 500, and realize real-time luminosity adjustment of the display screen during operation, so as to achieve an optimal display effect. The surge protection circuit 800 can prevent the LED in the display screen from being damaged due to the fact that a large surge current is generated at the moment of electrifying or the LED display screen is installed outdoors and is easily influenced by external environment factors, and therefore the surge protection circuit 800 can play a good protection role.

In a specific embodiment, the output ends of the red LED array 701, the green LED array 702, and the blue LED array 703 in the display screen module 700 are respectively and independently connected to a set of switch modules 600. The microcontroller 500 is used for sending logic signals to control the on and off of the switching transistor Q1/Q2/Q3 in a period, namely, the PWM wave occupies the duty ratio of the period occupied by the on time in the period to rapidly adjust the luminosity of the display screen module 700.

Preferably, the display screen module 700 includes a red LED array 701, a green LED array 702, a blue LED array 703 and at least three light intensity detection modules, which are a red light intensity detection module 704, a green light intensity detection module 705 and a blue light intensity detection module 706 shown in the figure, respectively, and each light intensity detection module detects the light intensity of the red LED array 701, the green LED array 702 and the blue LED array 703, respectively, and transmits a light intensity signal to the data interface 4 of the microcontroller 500. This enables the red LED array 701, the green LED array 702 and the blue LED array 703 to be individually controlled to adjust their luminosity.

Referring to fig. 3, the power conversion module 900 includes an input power source, an AC/DC converter 901 and a DC/DC converter 902, the input power source is connected to an input terminal of the AC/DC converter 901, an output terminal of the AC/DC converter 901 is connected to an input terminal of the DC/DC converter 902, and an output terminal of the DC/DC converter 902 is connected to the DC/DC converter 902. The AC/DC converter 901 adopts a 380V to 220V converter.

Preferably, the AC/DC converter 901 includes a fuse, a rectifier bridge, and a transient voltage suppressor, the fuse is connected in series with the input power source, and the transient voltage suppressor is connected to the rectifier bridge after being connected in parallel to both ends of the input power source. The transient voltage suppressor can prevent voltage overload, and the fuse plays a role in overheat protection.

In a specific embodiment, the surge protection circuit 800 includes a thermistor (NTC or PTC in the figure), a first capacitor C1/C2/C3 and a bleeder resistor R1/R2/R3, the thermistor is coupled to the display panel module 700 after being connected with the power conversion module 900, an input terminal of the first capacitor C1/C2/C3 is connected to an output terminal of the thermistor, an output terminal of the first capacitor C1/C2/C3 is grounded, and the bleeder resistor R1/R2/R3 is connected in parallel to two terminals of the first capacitor C1/C2/C3.

Preferably, the thermistor includes a negative temperature coefficient thermistor (e.g., NTC1/NTC2/NTC3 as shown in any of the figures) and a negative temperature coefficient thermistor (e.g., PTC1/PTC2/PTC3 as shown in any of the figures), and the negative temperature coefficient thermistor NTC and the negative temperature coefficient thermistor PTC are coupled to both ends of the power conversion module 900 and the display panel module 700 after being connected in series.

In a specific embodiment, the switch module 600 includes a transistor Q1/Q2/Q3, a voltage dividing resistor R7/R8/R9 and a pull-down resistor R4/R5/R6, the microcontroller 500 includes a PWM signal interface, the PWM signal interface is connected to an input terminal of the voltage dividing resistor R7/R8/R9, an output terminal of the voltage dividing resistor R7/R8/R9 is connected to a base of the transistor Q1/Q2/Q3, a collector of the transistor Q1/Q2/Q3 is connected to the display screen module 700, and an emitter of the transistor Q1/Q2/Q3 is connected to the pull-down resistor R4/R5/R6.

Referring to fig. 4, the light intensity detecting module includes a photo resistor CDS, a pull-up resistor R10, and an AD collector 7401, the photo resistor CDS is connected in series with the pull-up resistor R10, and a voltage output terminal of the photo resistor CDS is connected to the AD collector 7401 and further connected to a data interface of the microcontroller 500. Because the LEDs in the display module are powered by DC power, the input power is generally commercial power, and AC/DC converter 901 is required to convert AC power into DC power, and DC/DC converter 902 is required to convert voltage according to the operating voltage.

The control principle of the LED screen display system and the display screen in the embodiment is as follows: the light intensity detection module is arranged to feed back the light intensity of each LED array in real time, and the light intensity signal is fed back to the microcontroller, and the microcontroller 500 compares the light intensity signal with a preset standard range value to judge whether the luminosity and the chromaticity of the LED array need to be adjusted. The characteristic that the output voltage of the photoresistor CDS is different due to different resistance values of the photoresistor CDS in different light intensities is utilized, the output voltage of the photoresistor CDS is acquired after voltage division is carried out on the output voltage of the photoresistor CDS and is converted into a digital signal through the AD collector 7401 to be compared and calculated by the microcontroller 500.

The principle of the surge protection circuit 800 is as follows: in engineering application, the LED has weak capability of resisting surge current and reverse voltage, the negative temperature coefficient thermistor NTC can inhibit the sudden change of current, and the positive temperature coefficient thermistor PCT automatically regulates the current to finally keep the current in a specific range. The first capacitor C1/C2/C3 can be a point-release capacitor, the voltage sudden change caused by the power-on moment is restrained, the influence of voltage impact on the service life of the LED is reduced, and the bleeder resistor R1/R2/R3 provides an energy-consuming path for the energy storage element, so that the circuit is safe.

The above description is only the preferred embodiment of the present invention, and is not intended to limit the present invention, any modification, equivalent replacement, or improvement made within the design concept of the present invention should be included within the protection scope of the present invention.

Claims

1. An LED screen display system is characterized by comprising signal source input equipment, a video processor, a wireless transmitter, a wireless receiver, a microcontroller, a switch module, a display screen module, a surge protection circuit and a power supply conversion module, wherein the signal source input equipment is connected with the input end of the video processor, the output end of the video processor is connected with the wireless transmitter, the wireless transmitter transmits signals to the wireless receiver, the output end of the wireless receiver is connected with the input end of the microcontroller, and the output end of the microcontroller is connected with the input end of the switch module, so that the luminosity of the display screen module is adjusted;

the power conversion module is connected with the surge protection circuit in series and then connected to the display screen module, the surge protection circuit comprises a thermistor, a first capacitor and a bleeder resistor, the thermistor is coupled to the display screen module after being connected with the power conversion module, the input end of the first capacitor is connected to the output end of the thermistor, the output end of the first capacitor is grounded, and the bleeder resistor is connected to the two ends of the first capacitor in parallel.

2. The LED screen display system of claim 1, wherein the thermistor comprises a negative temperature coefficient thermistor and a positive temperature coefficient thermistor, and the negative temperature coefficient thermistor and the positive temperature coefficient thermistor are coupled to two ends of the power conversion module and the display screen module after being connected in series.

3. The LED screen display system according to claim 1, wherein the switch module comprises a transistor, a voltage dividing resistor and a pull-down resistor, the microcontroller comprises a PWM signal interface, the PWM signal interface is connected to an input terminal of the voltage dividing resistor, an output terminal of the voltage dividing resistor is connected to a base of the transistor, a collector of the transistor is connected to the display screen module, and an emitter of the transistor is connected to the pull-down resistor.

4. The LED screen display system of claim 3, wherein the output ends of the red LED array, the green LED array and the blue LED array in the display screen module are respectively and independently connected with a group of the switch modules.

5. The LED screen display system of claim 1, wherein the display screen module comprises a red LED array, a green LED array, a blue LED array and at least three light intensity detection modules, each of the light intensity detection modules respectively detects the light intensity of the red LED array, the green LED array and the blue LED array and transmits a light intensity signal to the data interface of the microcontroller.

6. The LED screen display system according to claim 5, wherein the light intensity detection module comprises a photoresistor, a pull-up resistor and an AD collector, the photoresistor is connected in series with the pull-up resistor, and a voltage output end of the photoresistor is connected to the AD collector and further connected to the data interface of the microcontroller.

7. The LED screen display system of claim 1, wherein the power conversion module comprises an input power source, an AC/DC converter and a DC/DC converter, the input power source is connected to an input end of the AC/DC converter, an output end of the AC/DC converter is connected to an input end of the DC/DC converter, and an output end of the DC/DC converter is connected to the DC/DC converter.

8. The LED screen display system of claim 7, wherein the AC/DC converter comprises a fuse, a rectifier bridge and a transient voltage suppressor, the fuse is connected in series with the input power source, and the transient voltage suppressor is connected to the rectifier bridge in parallel after both ends of the input power source.

9. The LED screen display system of claim 7, wherein the input power is 380V AC, and the AC/DC converter is a 380V to 220V converter.

10. A display screen comprising the LED screen display system of any one of claims 1 to 9.