Single-wire combined transmission LED device

Abstract

The invention relates to a single-wire combined transmission LED device, which comprises a substrate, a driving chip and an RGB LED chip group electrically connected with the driving chip are arranged on the top surface of the substrate, and a connecting end shared by a power supply and a data signal is arranged on the bottom surface of the substrate; the top surface of the substrate is also provided with a coupling separation circuit unit which is electrically connected between the driving chip and the connecting end and is used for identifying and separating a power supply and a data signal; the driving chip, the RGB LED chip group and the coupling and separating circuit unit are packaged on the top surface of the substrate through packaging colloid; the coupling and separating circuit unit comprises a high-pass filter circuit used for separating data signals and a low-pass filter circuit used for separating power signals. According to the invention, the number of physical interfaces is reduced, the packaging cost is reduced, the method is suitable for a high-density LED array, and cascade wiring is simplified.

Description

Technical Field

[0001] The present invention relates to the field of LED displays, and in particular to an LED device for single-line combined transmission. Background Art

[0002] With the development of technology, LED devices are widely used in the fields of lighting or display. Traditional LED devices require independent interfaces to separately transmit drive current (such as a power line) and control data (such as a PWM signal line), which leads to the following problems: 1) The interface is complex, and multiple connection terminals increase the packaging volume and production cost; 2) The wiring is redundant, and power lines and signal lines need to be separately arranged in an LED array (such as a display screen or a lighting module); 3) There is a risk of reliability, and multiple interfaces are easily affected by problems such as poor contact and oxidation. Summary of the Invention

[0003] In view of the existing deficiencies, the present invention provides an LED device for single-line combined transmission.

[0004] The technical solution adopted by the present invention to solve its technical problems is: an LED device for single-line combined transmission, including a substrate, on the top surface of the substrate are provided a driving chip and an RGB LED chip group electrically connected to the driving chip, and on the bottom surface of the substrate is provided a connection terminal shared by power supply and data signals; on the top surface of the substrate is also provided a coupling and separation circuit unit electrically connected between the driving chip and the connection terminal for identifying and separating the power supply and data signals; the driving chip, the RGB LED chip group and the coupling and separation circuit unit are encapsulated on the top surface of the substrate by an encapsulation colloid; the coupling and separation circuit unit includes a high-pass filter circuit for separating data signals and a low-pass filter circuit for separating power supply signals.

[0005] Preferably, the high-pass filter circuit includes an RC filter, a decoding module and a conversion control module connected in sequence. The RC filter filters out data signals from the mixed power supply and data signals and transmits them to the decoding module; the decoding module extracts data instructions from the received data signals and transmits them to the conversion control module; the conversion control module converts the received data instructions into pulse width modulation PWM data and transmits them to the driving chip.

[0006] Preferably, a Schmitt trigger is provided between the decoding module and the conversion control module.

[0007] Preferably, the data output by the decoding module includes first data with a high-level waveform and second data with a low-level waveform.

[0008] Preferably, a differential modulator is provided between the conversion control module and the driving chip.

[0009] Preferably, the low-pass filter circuit includes an inductor, a rectifying diode, and a power supply filter capacitor connected in sequence.

[0010] Preferably, the connection terminals include an input connection terminal and an output connection terminal, and the input connection terminal and the output connection terminal are arranged at two ends of the diagonal line of the bottom surface of the substrate.

[0011] Preferably, a heat diffusion layer covering the bottom surface of the substrate is arranged on the bottom surface of the substrate around the connection terminals.

[0012] Preferably, an antireflection film with a thickness of 1 / 4 of the emission wavelength is plated on the chip surface of the RGB LED chip group, and a distributed Bragg reflector is integrated on the bottom surface of the chip of the RGB LED chip group.

[0013] The beneficial effects of the present invention are as follows: in this invention, the driving chip, the RGB LED chip group, and the coupling and separation circuit are integrated on the top surface of the substrate through a packaging colloid to form a highly integrated system-level packaging structure, enhancing the overall anti-interference ability of the device. The coupling and separation circuit composed of a high-pass filter and a low-pass filter realizes the efficient separation of the power supply and the data signal in a single line, reducing the risk of signal crosstalk. The design of sharing the connection terminals for the power supply and the data signal reduces the physical interfaces and the packaging cost, is applicable to a high-density LED array, and simplifies the cascade wiring. Description of the Drawings

[0014] Figure 1 is a schematic diagram of the module composition on the substrate in the embodiment of the present invention;

[0015] Figure 2 is a schematic structural diagram of the embodiment of the present invention;

[0016] Names and serial numbers of the components in the figure: 1 - substrate, 2 - driving chip, 3 - RGB LED chip group, 4 - connection terminal, 5 - coupling and separation circuit unit, 50 - high-pass filter circuit, 51 - low-pass filter circuit, 52 - differential modulator, 500 - RC filter, 501 - decoding module, 502 - conversion control module, 503 - Schmitt trigger, 510 - inductor, 511 - rectifying diode, 512 - power supply filter capacitor, 6 - heat diffusion layer, 7 - antireflection film, 8 - distributed Bragg reflector. Detailed Embodiments

[0017] In order to more clearly illustrate the purpose, technical solutions, and advantages of the embodiments of the present invention, the present invention will be further described below in conjunction with the drawings and embodiments. The description is clear and complete. Obviously, the described embodiments are partial embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

[0018] Examples of the present invention, such as Figure 1 and Figure 2As shown in the figure, a single-line combined transmission LED device includes a substrate 1, which is made of a glass, silicon-based or ceramic substrate. On the top surface of the substrate 1, there are a driving chip 2 and an RGB LED chip group 3 electrically connected to the driving chip 2. The driving chip 2 is formed on the top surface of the substrate 1 through photolithography of the driving circuit. The driving chip 2 is connected to the RGB LED chip group 3 through gold wire bonding. The RGB LED chip group 3 includes a red LED chip, a green LED chip, and a blue LED chip. At the same time, an antireflection film 7 with a thickness of 1 / 4 of the emission wavelength is plated on the chip surface of the RGB LED chip group 3. A distributed Bragg reflector 8 is integrated on the bottom surface of the chips in the RGB LED chip group 3, that is, a distributed Bragg reflector 8 is provided on the bottom surface of each LED chip in the RGB LED chip group 3, and an antireflection film 7 is plated on the surface of each LED chip. For different color LED chips, the thickness of the antireflection film 7 is 1 / 4 of the wavelength of the emitted color light. The distributed Bragg reflector 8 is used to reduce light loss and reabsorption, improving the light extraction efficiency of the LED device. The antireflection film 7 is used to reduce the reflected light and increase the light transmission amount, thereby improving the imaging quality and clarity of the LED device. On the bottom surface of the substrate 1, there is a connection terminal 4 shared by the power supply and data signal. On the bottom surface of the substrate 1, a gold-plated copper foil is provided as the connection terminal 4 shared by the power supply and data. The bottom gold-plated copper foil is electrically connected to the driving circuit of the driving chip 2 on the top surface through a through hole (hole diameter 0.2 mm). The thickness of the copper plating layer on the inner wall of the through hole is ≥20 μm to reduce impedance. At this time, the connection terminal 4 includes an input connection terminal and an output connection terminal. The input connection terminal and the output connection terminal are arranged at both ends of the diagonal line on the bottom surface of the substrate 1. The arrangement of the input connection terminal and the output connection terminal on the diagonal line facilitates the connection between devices when multiple LED devices are connected into a matrix. On the top surface of the substrate 1, there is also a coupling and separation circuit unit 5 electrically connected between the driving chip 2 and the connection terminal 4 for identifying and separating the power supply and data signals. The driving chip 2, the RGB LED chip group 3, and the coupling and separation circuit unit 5 are encapsulated on the top surface of the substrate 1 with an encapsulation colloid. The encapsulation colloid is selected as a high light transmittance silica gel (refractive index ≥1.5), which forms a protective layer after curing, integrating the driving chip 2, the RGB LED chip group 3, and the coupling and separation circuit unit 5 into a whole. The coupling and separation circuit unit 5 includes a high-pass filter circuit 50 for separating the data signal and a low-pass filter circuit 51 for separating the power signal. The high-pass filter circuit 50 is used to extract the data signal and transmit it to the driving chip 2, and the low-pass filter circuit 51 is used to separate the DC power signal and distribute it to the RGB LED chip group.The high-pass filter circuit 50 includes an RC filter 500, a decoding module 501, and a conversion control module 502 that are connected in sequence. The RC filter 500 filters out the data signal from the mixed power supply and data signal and transmits it to the decoding module 501. The decoding module 501 extracts data instructions from the received data signal and transmits them to the conversion control module 502. The conversion control module 502 converts the received data instructions into pulse-width modulation PWM data and transmits it to the driver chip 2. For example, if the RC filter 500 uses a first-order passive RC high-pass filter, it is composed of a resistor (R1 = 1kΩ) and a capacitor (C1 = 100pF) in series. It is used to filter out the low-frequency power supply noise in the mixed signal and retain the high-frequency data signal. The filtered data signal is then transmitted to the input terminal of the decoding module 501. The decoding module 501 uses an integrated digital signal processor with a built-in Manchester decoding protocol. It uses it to identify the high and low level transitions (such as the rising edge being "1" and the falling edge being "0"). After receiving the data signal output by the RC high-pass filter, it eliminates the residual noise through a threshold comparator, analyzes the data packet, checks the parity bit, and then outputs it to the conversion control module 502. The decoding module 501 detects, samples, and judges the received data signal and generates output data with different level waveforms and outputs it to the conversion control module 502. The decoding module 501 samples the data and oversamples it at a rate of ≥4 times the signal frequency (such as 80kHz for a 20kHz signal). It distinguishes the valid signal from the noise through a threshold comparator (the reference voltage is usually set to 30%-50% of the signal amplitude, such as 0.5V), filters out the low-amplitude interference, identifies the high and low level transitions of the data according to the Manchester decoding protocol, captures the signal transition edge, extracts the address code (8bit), brightness value (16bit), and parity bit to check the data integrity (such as the parity bit matching). Finally, it converts the decoded digital signal into a standard level signal and outputs it to the conversion control module 502. The output data includes first data with a high-level waveform and second data with a low-level waveform. The conversion control module 502 is implemented using an FPGA chip, converts the decoded brightness value (0-255) into a PWM signal with an adjustable duty cycle, and transmits the PWM signal to the driver chip 2 through the LVDS level standard.

[0019] A further improvement, such as Figure 1 As shown in, a Schmitt trigger 503 is provided between the decoding module 501 and the conversion control module 502 to eliminate signal jitter and shape the waveform, and output a stable level to the conversion control module 502.

[0020] A further improvement, such as Figure 1As shown in [reference], a differential modulator 52 is provided between the conversion control module 502 and the driving chip 2. The differential modulator 52 differentially encodes the data signal separated by the high-pass filter circuit to generate a differential signal resistant to common-mode noise. For example, an LVDS differential driving chip is used to convert a single-ended data signal into a differential signal. The input end is connected to the data signal output by the high-pass filter circuit, and the output end is connected to the driving chip 2.

[0021] Further improvements, such as Figure 1 As shown in [reference], the low-pass filter circuit 51 includes an inductor 510, a rectifying diode 511, and a power supply filtering capacitor 512 connected in series in sequence. The inductor 510 uses a ferrite core power inductor (10 μH, high-frequency choke) to suppress high-frequency ripple current; the rectifying diode 511 uses a fast-recovery diode to rectify the AC input signal into a single-direction pulsating DC; the power supply filtering capacitor 512 uses an electrolytic capacitor (capacitance value C1 = 100 μF) to filter out low-frequency ripple.

[0022] Further improvements, such as Figure 2 As shown in [reference], a heat diffusion layer 6 covering the bottom surface of the substrate 1 is provided around the connection end on the bottom surface of the substrate 1. The heat diffusion layer 6 is made of graphene, a copper-based composite material, or a metal-ceramic hybrid material, and is used to laterally and evenly disperse heat, avoid local heat accumulation, and improve the heat dissipation ability of the LED device.

[0023] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. An LED device for single-line combined transmission, characterized in that, It includes a substrate, on the top surface of which a driving chip and an RGB LED chip group electrically connected to the driving chip are provided, and on the bottom surface of which a connection terminal shared by power supply and data signals is provided; a coupling and separation circuit unit for identifying and separating the power supply and data signals is also provided on the top surface of the substrate and electrically connected between the driving chip and the connection terminal; the driving chip, the RGB LED chip group and the coupling and separation circuit unit are encapsulated on the top surface of the substrate by encapsulation colloid. The coupling and separation circuit unit includes a high-pass filter circuit for separating data signals and a low-pass filter circuit for separating power supply signals.

2. The LED device for single-line combined transmission according to claim 1, wherein The high-pass filter circuit includes an RC filter, a decoding module and a conversion control module connected in sequence. The RC filter filters out data signals from the mixed power supply and data signals and transmits them to the decoding module; the decoding module extracts data instructions from the received data signals and transmits them to the conversion control module; the conversion control module converts the received data instructions into pulse width modulation PWM data and transmits them to the driving chip.

3. The LED device for single-line combined transmission according to claim 2, wherein A Schmitt trigger is provided between the decoding module and the conversion control module.

4. The LED device for single-line merged transmission according to claim 2, wherein The data output by the decoding module includes first data with a high-level waveform and second data with a low-level waveform.

5. The single-line merged transmission LED device according to claim 2, wherein A differential modulator is provided between the conversion control module and the driving chip.

6. The LED device for single-line combined transmission according to claim 1, wherein The low-pass filter circuit includes an inductor, a rectifying diode and a power supply filter capacitor connected in sequence.

7. The single-line merged transmission LED device according to claim 1, characterized in that The connection terminal includes an input connection terminal and an output connection terminal, and the input connection terminal and the output connection terminal are arranged at both ends of the diagonal line of the bottom surface of the substrate.

8. The LED device for single-line combined transmission according to claim 1, characterized in that A heat diffusion layer covering the bottom surface of the substrate is provided on the bottom surface of the substrate around the connection terminal.

9. The LED device for single-line combined transmission according to claim 1, wherein The surface of the chip of the RGB LED chip group is coated with an antireflection film with a thickness of 1 / 4 of the emission wavelength, and a distributed Bragg reflector is integrated on the bottom surface of the chip of the RGB LED chip group.

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