CN115734423A

CN115734423A - LED array driving scheme

Info

Publication number: CN115734423A
Application number: CN202211467067.7A
Authority: CN
Inventors: 阮航
Original assignee: Qingdao Guanluo Intelligent Machinery Technology Co ltd
Current assignee: Qingdao Guanluo Intelligent Machinery Technology Co ltd
Priority date: 2022-11-22
Filing date: 2022-11-22
Publication date: 2023-03-03

Abstract

The invention discloses an LED array driving scheme, and relates to the technical field of LED array driving; the problem that the signal transmission bandwidth of an LED driving circuit is limited is solved; the method specifically comprises the following steps: an ADC-LEDDriver and a DC-DC power supply module are integrated in the LED driving chip; the input signal of the LED driving chip is changed into an analog signal from a digital signal; the ADC-LEDDriver samples the analog signal and outputs the LED driving signal, and the ADC-LEDDriver is triggered by the combination of a clock signal and a GPIO signal which are input to the LED driving chip; the DC-DC power supply module is used for providing relatively independent stable power supply and ground level for the LEDs in the area. The input analog signal can avoid the bandwidth limitation of the serial digital signal, the number of the driving chips connected in series on one analog signal line can be greatly increased, and the power supply module can provide stable and consistent working voltage and low level.

Description

LED array driving scheme

Technical Field

The invention relates to the technical field of LED array driving, in particular to an LED array driving scheme.

Background

At present, the development of miniLED (LED chip with chip size between 50-200 μm) or micro LED (LED with LED unit smaller than 50 μm) array driving technology has reached a new technology height, and independent addressing and self-luminescence can be realized. The miniLED or the micro LED is mainly applied to two aspects, firstly, the miniLED or the micro LED is used as the backlight of an LCD liquid crystal display product and is used for providing a light source, and compared with a common large-size LED backlight LCD product, the miniLED or the micro LED backlight product has the characteristics of smaller independent control partition, high contrast ratio, low power consumption, long service life and good image quality; and secondly, compared with a liquid crystal display screen, the mini/micro LED display screen which is a product for directly displaying images or videos has the advantages of self-luminescence, wide color gamut, high contrast, quick response time and easy realization of a super-large display screen with the size of 200 inches and the like.

In the prior art, the driving schemes of the mLED arrays are basically consistent whether the mLED arrays are used as backlight or display applications, and a large number of driving chips are mainly used for driving the mLED particles in the vicinity of each mLED array, namely, AM driving. However, with the increase of image quality requirements, the number of LED chips in miniLED backlight application is rapidly increased to several tens of thousands, for example, 20736miniLED light emitting chips are integrated in 86 inches of a creative-dimension Q72 large screen, and nearly hundreds of driver chips adopt SPI to transmit data, which cannot meet the requirement of fast transmission of large data volume, so that the defect of limited signal transmission bandwidth of an LED driver circuit exists.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provides an LED array driving scheme.

In order to achieve the purpose, the invention adopts the following technical scheme:

an LED array driving scheme comprising the following:

s1: an ADC-LED Driver and a DC-DC power supply module are integrated in the LED driving chip;

s2: the input signal of the LED driving chip is changed into an analog signal from a digital signal;

s3: the ADC-LED Driver samples the analog signal and outputs an LED driving signal, and the sampling is triggered by the combination of a clock signal and a GPIO signal which are input to the LED driving chip;

the DC-DC power supply module is used for providing relatively independent stable power supply and ground level for the LEDs in the region.

Preferably: the driving framework of the LED driving chip comprises an LED SD _ G Driver functional module, an LED and a peripheral circuit of a DC-DC power supply module.

Preferably: the LED SD _ G Driver functional module further comprises an input signal and an output signal.

Preferably: the input signal is a content signal to be displayed by the LED array and comprises a digital image signal, a frame synchronization clock signal and a line synchronization clock signal; the output signals comprise analog signals, frame synchronization clock signals, line synchronization clock signals and GPIO combined signals after DA conversion is carried out on digital image signals.

Preferably: the LED driving chip comprises an I/O port for function expansion, and the function expansion is realized by matching with Vsync and cpv clock signals and the time sequence of GPIO and Sn.

Preferably: the LED array driving working modes comprise a synchronous working mode, an asynchronous working mode and an addressing working mode.

Preferably: and in the synchronous working mode, the frame synchronization signal Vsync and the row synchronization signal CPV clock signal output to the LED driving chip by all the LED SD _ G Driver functional modules on the single board and other GPIOs are kept in synchronous states.

Preferably: the asynchronous working mode is that the frame synchronization signal Vsync output by the LED SD _ G Driver functional module on the single board to the LED driving chip is asynchronous with the horizontal synchronization signal CPV clock signal and other GPIOs.

Preferably: the addressing working mode is that the frame synchronization signal Vsync and the row synchronization signal CPV clock signal output to the LED driving chip by the LED SD _ G Driver functional module are matched with other GPIO signals, a certain row, a certain column or a certain ADC-LED Driver is selected to receive a signal transmitted by the SIN, and corresponding LED partitions are controlled independently.

Preferably: after S3, the following is also included:

s4: the DC-DC module in the ADC-LED Driver generates the ADC-LED Driver and the LED under the combined action of the peripheral circuit, and the ADC-LED Driver and the LED can obtain the consistent power supply and ground level.

The invention has the beneficial effects that:

1. the invention lays out the driving framework of the LED driving chip according to the driving principle of the LCD, sets the LED SD _ G Driver function module when the LED driving chip array is driven, is used for realizing the source Driver function and the gate Driver function similar to those in the LCD display driving, sets the clock signals such as the frame synchronization signal Vsync, the line synchronization signal CPV and the like, changes the input signal of the LED driving chip from a digital signal to an analog signal, the input analog signal can avoid the bandwidth limitation of the serial digital signal, can greatly increase the number of the driving chips connected in series on one analog signal line, and the power supply module can provide stable and consistent working voltage and low level, thereby realizing the driving of the high-density LED array on a large-size high-resistance substrate.

2. According to the invention, an I/O port for positioning, a frame synchronization signal input and output port, a line synchronization signal input and output port and an ADC-LED Driver are added on the basis of the existing LED driving chip to realize analog-to-digital conversion, so that the LED driving chip can normally receive analog signals.

3. The invention can realize the driving part of the current LED array on an integral functional board, forms the viewing experience similar to the LCD, is beneficial to the design and manufacture of large size and high density, and realizes the driving scheme of the large size and high density array.

4. According to the invention, the DC-DC power supply module provides relatively independent stable power supply and ground level for the LEDs in the region, so that the LED driving chip has stable power supply capability, the problems of circuit working stability and consistency caused by line loss and voltage drop can be avoided, and the requirements of stability and current control precision of LED driving are met; in the application of glass-based LED direct display, the reduction of the thickness of copper wires is eliminated, the wire impedance caused by the lengthening of the wires is increased, and the working voltage of an LED driving chip is stabilized.

Drawings

Fig. 1 is a schematic flow chart of an embodiment 1 of a driving scheme of an LED array according to the present invention;

FIG. 2 is a schematic flow chart of an embodiment 2 of an LED array driving scheme according to the present invention;

FIG. 3 is a schematic diagram of a driving chip of an LED array driving scheme according to the present invention;

FIG. 4 is a diagram of an exemplary LCD driving architecture;

fig. 5 is a schematic diagram of a driving architecture of an LED driving chip according to an LED array driving scheme of the present invention;

fig. 6 is a schematic diagram of an mLED circuit in a backlight with a voltage regulation module added according to an LED array driving scheme of the present invention.

Detailed Description

The technical solution of the present patent will be further described in detail with reference to the following embodiments.

Reference will now be made in detail to embodiments of the present patent, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are illustrative only for the purpose of explaining the present patent and are not to be construed as limiting the present patent.

Example 1:

an LED array driving scheme, as shown in fig. 1 and 3-5, comprising the following:

s1: an ADC-LED Driver (ADC conversion module) and a DC-DC power supply module are integrated in the LED driving chip;

s2: the driving framework of the LED driving chip is laid out by referring to the driving principle of the LCD, and the input signal of the LED driving chip is changed into an analog signal from a digital signal; the input analog signal can avoid the bandwidth limitation of serial digital signals, the number of driving chips connected in series on one analog signal line can be greatly increased, and the power supply module can provide stable and consistent working voltage and low level, so that the driving of a high-density LED array on a large-size high-resistance substrate is realized.

S3: the ADC-LED Driver samples the analog signal and outputs an LED driving signal, and the sampling is triggered by the combination of a clock signal and a GPIO signal which are input to the LED driving chip; and the ADC-LED Driver performs AD conversion on the analog signal output by the LED SD _ G Driver functional module under the triggering of a clock signal or the combination of the clock signal and the GPIO signal, and finishes the output of an LED driving signal.

Preferably, the LED emits light or does not emit light under the action of the ADC-LED Driver output driving signal.

The frame start and line start control functions in the liquid crystal drive are integrated into the LED SD _ G Driver functional module, so that the LED SD _ G Driver functional module has the functions of controlling the start of one frame of data and one line of data. The LED SD _ G Driver functional module receives a frame start control signal Vsync, a row start control signal CPV, and both signals directly pass through the LED SD _ G _ Driver without processing, and then enter a general LED driving chip.

The driving framework of the LED driving chip comprises an LED SD _ G Driver functional module, an integrated multifunctional LED driving chip, an LED and a peripheral circuit of a DC-DC power supply module.

Further, the LED SD _ G Driver functional module further includes an input signal for implementing a source Driver function in the LCD display Driver and an output signal for implementing a gate Driver function in the LCD display Driver;

preferably, the input signal is a content signal to be displayed by the LED array, and includes a digital image signal, a frame synchronization clock signal, and a line synchronization clock signal.

Preferably, the output signal comprises an analog signal, a frame synchronization clock signal, a line synchronization clock signal and a GPIO combined signal after DA conversion of the digital image signal; the frame synchronization clock signal and the line synchronization clock signal can be obtained by decoding from the digital image signal; and the receiving end of the output signal is an ADC-LED Driver.

The DC-DC power supply module is used for providing a relatively independent stable power supply and a ground level for the LEDs in the area; the inconsistency of the ground level affects the sampling accuracy of input signals and the sampling accuracy of output currents of the driving chip, the inconsistency of the power supply voltage affects the actual output capacity and stability of the driving chip, the DC-DC power supply module enables the LED driving chip to have stable power supply capacity, the problems of circuit working stability and consistency caused by line loss and voltage drop can be avoided, and the requirements of stability and current control accuracy of LED driving are met.

An I/O port is additionally arranged on the LED driving chip to expand the function, and the operation method of the function expansion is realized by matching with clock signals such as Vsync and cpv and the like and the time sequence of GPIO and Sn.

S1-S3, equivalently enabling the LED driving chip to be a TFT structure in liquid crystal driving; the input signal is equivalent to the output of a source driver of the LCD, while the output signal circuit is distributed inside each LED driving chip.

The LED array driving working mode comprises a synchronous working mode, an asynchronous working mode and an addressing working mode, wherein the synchronous working mode is that clock signals such as a frame synchronization signal Vsync and a line synchronization signal CPV which are output to an LED driving chip by all LED SD _ G Driver functional modules on a single board and other GPIOs are kept in a synchronous state, at the moment, actions executed by the LED driving chips in each line are synchronous, namely, the control of LED subareas in each line is synchronous;

further, in the asynchronous working mode, clock signals such as a frame synchronization signal Vsync and a row synchronization signal CPV output by the LED SD _ G Driver functional module on the single board to the LED driving chip and other GPIOs are not synchronous, at this time, actions performed by the LED driving chips in each column and each row are not necessarily synchronous, and control of each corresponding LED partition is not synchronous;

preferably, the asynchronous working mode may be implemented in a certain LED SD _ G Driver functional module, or in multiple LED SD _ G Driver functional modules on a single board, or in multiple lamp panels on a single machine.

Furthermore, the addressing operation mode is that clock signals such as a frame synchronization signal Vsync and a row synchronization signal CPV output by the LED SD _ G Driver functional module to the LED driving chip can select a certain row, a certain column, or a certain ADC-LED Driver to receive a signal transmitted by the SIN under the coordination of other GPIO signals, and perform independent control on a corresponding LED partition.

Preferably, the LED in the present invention includes a miniLED, a micro LED, or the like.

When the embodiment is used, referring to the LCD driving scheme, an LED SD _ G Driver functional module is set during driving of the LED driving chip array, and is used for realizing a source Driver function and a gate Driver function similar to those in LCD display driving, and setting clock signals such as a frame synchronization signal Vsync and a line synchronization signal CPV; an I/O port for positioning, a frame synchronization signal input and output port, a line synchronization signal input and output port and an ADC-LED Driver are added on the basis of the LED driving chip to realize analog-to-digital conversion, so that the LED driving chip can normally receive analog signals; the DC-DC power supply module enables the LED driving chip to have stable power supply capacity, and can avoid the problems of circuit working stability and consistency caused by line loss and voltage drop. And the driving part of the current LED array can be realized on an integral functional board, the viewing experience similar to that of an LCD is formed, the large-size and high-density design and manufacture are facilitated, and the large-size and high-density array driving scheme is realized.

Example 2:

an LED array driving scheme aims to solve the problem of insufficient voltage of a driving chip caused by line resistance; as shown in fig. 2 and fig. 6, the present embodiment is modified from embodiment 1 in the following manner: the method also comprises the following steps:

s5: the DC-DC module in the ADC-LED Driver generates consistent power supply and ground level for the ADC-LED Driver and the LED under the combined action of the peripheral circuit, so that the stable working state is kept. This avoids the ADC-LED Driver and the LEDs it drives being affected by inconsistent supply and ground levels due to their different positions in the array.

When the LED driving circuit is used, the DC-DC module in the DC-LED Driver generates the ADC-LED Driver and the LED can obtain the consistent power supply and ground level under the combined action of the peripheral circuit, so that the stable working state is kept. In the application of glass-based LED direct display, the reduction of the thickness of copper wires is eliminated, the wire impedance caused by the lengthening of the wires is increased, and the working voltage of an LED driving chip is stabilized.

Application example 1:

assuming that the LED array has M rows and N columns of driving chips, each driving chip can drive three LED chips on the left and right sides as shown in the red frame on the right side in fig. 5, the total number of LED chips that can be driven by the entire miniLED array is 3 × M × 2 × N, and since each LED driving chip has six outputs, six ADC samples are performed inside the LED driving chip on the nth row.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims

1. An LED array driving scheme, comprising:

2. The LED array driving scheme according to claim 1, wherein the driving architecture of the LED driving chip comprises an LED SD _ G Driver functional module, LEDs and peripheral circuits of a DC-DC power supply module.

3. An LED array driving scheme according to claim 2 wherein the LED SD _ G Driver functional module further comprises an input signal and an output signal.

4. The LED array driving scheme according to claim 3, wherein the input signal is a content signal to be displayed by the LED array, comprising a digital image signal, a frame synchronization clock signal, and a line synchronization clock signal; the output signals comprise analog signals, frame synchronization clock signals, line synchronization clock signals and GPIO combined signals after DA conversion is carried out on the digital image signals.

5. The LED array driving scheme as claimed in claim 4, wherein the LED driving chip comprises I/O port for function expansion, and the function expansion is performed by timing coordination with Vsync, cpv clock signal and GPIO and Sn.

6. The LED array driving scheme of claim 1, wherein the LED array driving modes comprise a synchronous mode, an asynchronous mode, and an addressing mode.

7. The LED array driving scheme according to claim 6, wherein the synchronous operation mode is that all the LED SD _ G Driver functional modules on the single board output the frame synchronization signal Vsync and the row synchronization signal CPV clock signal to the LED driving chip and other GPIOs to keep synchronous.

8. The LED array driving scheme according to claim 7, wherein the asynchronous operation mode is that the frame synchronization signal Vsync output by the LED SD _ G Driver functional module on the single board to the LED driving chip is not synchronized with the line synchronization signal CPV clock signal and other GPIOs.

9. The LED array driving scheme according to claim 8, wherein the addressing operation mode is that the LED SD _ G Driver functional module outputs a frame synchronization signal Vsync and a row synchronization signal CPV clock signal to the LED driving chip, and selects a row, a column or an ADC-LED Driver to receive a signal transmitted by the SIN and independently control the corresponding LED partition in cooperation with other GPIO signals.

10. The LED array driving scheme of claim 1, further comprising, after S3: