WO2023030113A1

WO2023030113A1 - Driving control method and device for led display screen

Info

Publication number: WO2023030113A1
Application number: PCT/CN2022/114394
Authority: WO
Inventors: 王可睿
Original assignee: 北京芯格诺微电子有限公司
Priority date: 2021-09-01
Filing date: 2022-08-24
Publication date: 2023-03-09
Also published as: CN113724646A; CN113724646B

Abstract

Disclosed in the present invention is a driving control device for an LED display screen. The driving control device comprises an array composed of a plurality of LED driving control chips. Each LED driving control chip comprises an enable pin, a data pin, and a plurality of brightness control pins. In the array composed of the plurality of LED driving control chips, the enable pins of the LED driving control chips in each row of the array are connected to form gate lines of the row of LED driving control chips, and the data pins of the LED driving control chips in each column are connected to form a data line of the column of LED driving control chips. When a clock signal is input on the gate line, all the LED driving control chips on the gate line are gated, and brightness data input on a data line thereof and used for controlling the brightness of an LED light-emitting element can be received. The brightness data comprises multiple groups of data, and each group of data controls the brightness of a corresponding group of LED light-emitting elements by means of a corresponding brightness control pin.

Description

Driving control method and device for LED display

technical field

The invention relates to the technical field of display driving, in particular to a driving control method and device for LED display screens.

Background technique

Light-emitting diodes (LEDs) have the characteristics of long life, high brightness, and waterproof and dustproof. With the advancement of manufacturing technology, LED has been widely used in the field of screen display in recent years. In practical applications, a large number of LED elements are arranged in an array on the backlight layer inside the display panel, and the LED elements are connected to the output pins of the driving chip. In order to save the number of chips, each LED driver chip usually has multiple output channels, that is, one LED driver chip can independently control the brightness of multiple LED elements connected to its output pins. Since the brightness of the LED is related to the magnitude of the current flowing through it, the user can control the magnitude of the current on each LED channel through the communication control interface provided by the LED driver chip, thereby realizing brightness control.

At present, the communication control methods of most display LED driver chips are introduced as follows. As shown in Figure 1, assuming that one LED driver chip controls 4 channels, the chip has 5 communication control pins. Among them, 4 pins are enable pins, providing enable signals of different channels. The other 1 pin is a data pin, which provides brightness data. FIG. 2 shows the topological relationship of the LED driver chip array and LED elements in the prior art. When adjusting the brightness of the LEDs in the array, all enable pins such as C1 and C2 are selected in sequence, and at the same time, the brightness data of the corresponding LEDs are input on all data pins such as D1 and D2. For example, when selecting C1, D1, D2, D3 and other data pins input the corresponding brightness data of LED11, LED12 and LED13 respectively; when selecting C2, D1, D2, D3 and other data pins respectively input LED21, LED22 and LED23 at the same time Corresponding brightness data.

The communication control method in the prior art only implements a time-division multiplexing strategy for data pins. For channel enable pins, no multiplexing is performed. This results in too many chip pins, increasing the manufacturing cost of the chip. In addition, too many chip pins bring great challenges to the wiring of integrated circuits and the integrity of signal transmission. When the number of output channels of the LED driver chip increases, the above problems will become more serious.

Contents of the invention

One of the technical problems to be solved by the present invention is to reduce the number of pins of the LED drive control chip, thereby simplifying the circuit complexity of the LED display device in the wiring process of the integrated circuit.

In order to solve the above technical problems, the present invention provides a drive control device for LED display screens, the drive control device includes an array composed of a plurality of LED drive control chips, and the LED drive control chip includes an enabling tube pin, a data pin and multiple brightness control pins;

In the array composed of a plurality of LED drive control chips, the enable pins of the LED drive control chips in each row of the array are connected to form the gate lines of the LED drive control chips in the row, and the LED drive control chips in each column The data pins of the chip are connected to form the data line of the LED drive control chip;

When a clock signal is input on the gate line, all the LED drive control chips on the gate line are gated, and can receive the brightness data input on the data line for controlling the brightness of the LED light-emitting element; the brightness The data includes multiple sets of data, and each set of data controls the brightness of a corresponding group of LED light-emitting elements through a corresponding brightness control pin.

In one embodiment, the LED driving control chip uses the same clock frequency as that on the gate line to sample the brightness data information on the data pin, so as to sequentially obtain the brightness data of the LED light-emitting elements of multiple channels it controls.

The present invention also provides a drive control device for LED display screens, the drive control device includes an array composed of a plurality of LED drive control chips, and the LED drive control chip includes an enabling pin, a data pin and multiple brightness control pins;

When a high-level signal is input on the gate line, all the LED drive control chips on the gate line are gated, and can receive the brightness data input on the data line for controlling the brightness of the LED light-emitting element; The brightness data includes multiple sets of data, and each set of data controls the brightness of a corresponding group of LED light-emitting elements through a corresponding brightness control pin;

The starting position of each group of data also includes an auxiliary clock signal.

In one embodiment, the LED drive control chip uses the clock frequency of the auxiliary clock signal at each data start position to sample the brightness data information on the data pins, so as to sequentially know the LED light-emitting elements of multiple channels it controls Brightness data.

Another aspect of the present invention is to provide a driving control method for an LED display, the method comprising:

The LED drive control chip is used to form an LED drive control array; the LED drive control chip includes an enabling pin, a data pin and a plurality of brightness control pins;

In one embodiment, when the clock signal selected by one gate line becomes a continuous low level, the gate line to be selected by the next row remains at a low level for a predetermined duration, and the clock signal of the gate line to be selected by the next row When the first rising edge of the signal arrives, the data line starts to input the LED brightness data.

The present invention also provides a driving control method for an LED display, the method comprising:

In one embodiment, when the clock signal selected by a gate line becomes a continuous low level, the gate line to be selected by the next line is kept at a low level for a predetermined period of time, and the signal of the gate line to be selected by the next line is pulled When high, the data line starts to input LED brightness data.

Compared with the prior art, one or more embodiments of the present invention may have the following advantages:

In the present invention, by only using one enable pin and one data pin of the LED drive control chip, the simultaneous multiplexing of the enable pin and the data pin of the drive control chip is realized, thereby greatly simplifying the design of the LED drive control circuit. The complexity of the wiring simplifies the complexity of the LED control drive integrated circuit.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the attached picture:

FIG. 1 is a schematic structural diagram of an LED drive control chip in the prior art;

Fig. 2 is a structural schematic diagram of an LED drive control array in the prior art;

3 is a schematic structural diagram of an LED drive control chip according to an embodiment of the present invention;

4 is a schematic structural diagram of an LED drive control array according to an embodiment of the present invention;

5 is a schematic diagram of the communication protocol of the gate line and the data line of the LED drive control device according to an embodiment of the present invention;

6 is a schematic diagram of the communication protocol of the gate line and the data line of the LED drive control device according to another embodiment of the present invention;

Detailed ways

In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with accompanying drawings 3-6.

first embodiment

Fig. 3 is a schematic diagram of an LED driving chip according to an embodiment of the present invention. Fig. 4 is a schematic structural diagram of an LED driving mechanism composed of an LED driving chip array according to an embodiment of the present invention. The present invention will be described below in conjunction with FIGS. 3-4 .

As shown in FIG. 3 , in this embodiment, each LED driver chip includes 4 output channels, which are respectively connected to 4 groups of LED elements. In terms of communication control, each LED driver chip only includes one enable pin C and one data pin D. By time-division multiplexing the enable pin C and the data pin D, the brightness of the LED elements on the 4 output channels is controlled.

The LED driver chips of this embodiment are used to form an LED driver chip array as shown in FIG. 4 to adjust the LED brightness of the LED display device. When adjusting the brightness of the LED, select all enable pins such as C1, C2, ... and so on in sequence. At the same time, the brightness data of 4 groups of LEDs are continuously input on all data pins D such as D1 and D2. Take D1 as an example, when C1 is selected, D1 will input 4 sets of data in sequence, corresponding to the brightness of LED11, LED21, LED31 and LED41 respectively. When C2 is selected, D1 inputs 4 sets of data in turn, corresponding to the brightness of LED51, LED61, LED71 and LED81 respectively.

In this embodiment, in order to enable multiplexing of the enable pin C, only one enable pin C is set, so when a certain enable pin C is selected, the LED input through the data pin D The brightness data needs to be further stipulated in the communication protocol, so that the LED driver chip can decode the LED brightness data input by the data pin D, so as to complete the correct brightness control of the four groups of LED components controlled by the LED driver chip.

As shown in Figure 5, in this embodiment, the communication protocol mode followed by the enable pin C and the data pin D is: when the enable pin C of the LED driver chip inputs a clock signal, it indicates that the LED driver chip is Strobe; at the same time, the brightness data is input from the data pin D. The luminance data includes 4 sets of data, and each set of data has N bits. Taking the gate line C1 as an example, for the D1 data line, the first, second, third, and fourth sets of data successively represent the brightness instructions of LED11, LED21, LED31, and LED41; at the same time, the D2 data line is synchronously transmitting LED12, The brightness commands of LED22, LED32, and LED42; the brightness commands of LED13, LED23, LED33, and LED43 are transmitted synchronously on the D3 data line. Each gated LED driver chip synchronously samples the data information on the data pin D according to the clock input on the enable pin C, so as to sequentially obtain the LED brightness instructions of the four channels it controls. When the strobe lines C1, C2, C3, C4... are strobed in turn and the input of the LED brightness data is completed at the same time, the progressive scanning of the brightness control of the LED display is completed. When the selection of a certain selection line ends, that is, when the clock signal of the selection line changes to a continuous low level, it is stipulated that the selection line to be selected in the next line will not input the clock signal for selection immediately, but the The gate line to be gated in the next row remains low for a period of time t. During the time t, the previous gate line and the next line are both in the low level state, and the input data of the corresponding data line within the time t It will not be received by the LED driver chip either. An optional manner is that the data line input is at low level within the time t. When the first rising edge of the clock signal of the gate line to be selected in the next row arrives, the data line starts to input LED brightness data. Through the above settings, it can be guaranteed that the LED brightness data input by the data line can be completely received by the chip every time.

According to the characteristics of light-emitting LED devices, its brightness is positively related to the current flowing through it. Therefore, in this embodiment, the luminance data input by the data pin D is essentially a current command, which is used to configure the target value of the constant current control on the drive port of the LED driver chip. There are many ways for the LED driver chip to realize constant current control. The common way is to form a negative feedback loop by the operational amplifier and the driven MOSFET, so that the voltage value of the feedback terminal of the operational amplifier is close to the voltage value of the reference terminal. Since the voltage value of the feedback terminal is proportional to the current on the LED light string, the current on the LED light string can be controlled by controlling the reference terminal voltage. Therefore, the essence of the constant current control command is the voltage of the reference terminal of the operational amplifier.

second embodiment

The LED driving chip and the driving array formed by the LED driving chip in this embodiment are the same as those in the first embodiment. The difference between this embodiment and the first embodiment is that the enable pin C and data pin D follow The communication protocol mode has been improved, as shown in Figure 6, the communication protocol mode followed by the enable pin C and the data pin D in this embodiment is: the enable pin C of the LED driver chip inputs a high level signal When , it indicates that the LED driver chip is strobed; at the same time, the brightness data is input from the data pin D. The brightness data includes 4 groups of brightness data and auxiliary clock data, each group of brightness data has N bits, and the auxiliary clock data is placed before the brightness data, which is used to determine the sampling clock frequency of the LED driver chip for the brightness data. Taking the gate line C1 as an example, for the D1 data line, the first, second, third, and fourth sets of data successively represent the brightness instructions of LED11, LED21, LED31, and LED41; at the same time, the D2 data line is synchronously transmitting LED12, The brightness commands of LED22, LED32, and LED42; the brightness commands of LED13, LED23, LED33, and LED43 are transmitted synchronously on the D3 data line. Each gated LED driver chip uses the auxiliary clock frequency output by the data line to sample the data information on the data pin D according to the high-level input on the enable pin C, so as to sequentially know the LEDs of the four channels it controls. Brightness command. When the strobe lines C1, C2, C3, C4... are strobed in turn and the input of the LED brightness data is completed at the same time, the progressive scanning of the brightness control of the LED display is completed. When the selection of a certain selection line ends, that is, when the signal of the selection line becomes a continuous low level, it is stipulated that the selection line to be selected in the next row will not input a high-level signal for selection immediately, but the The gate line to be gated in the next row remains at a low level for a period of time t. During the time t, the previous gate line and the next line are both in a low level state, and the input data of the corresponding data line within the time t It will not be received by the LED driver chip either. An optional manner is that the data line input is at low level within the time t. When the next line pulls the signal of the gate line to be strobed high, the data line starts to input the LED brightness data. Through the above settings, it can be guaranteed that the LED brightness data input by the data line can be completely received by the chip every time.

In this embodiment, every time data is transmitted from the data line to the LED driver chip, the auxiliary clock signal data of 2 cycles will be input to the LED driver chip first, and the auxiliary clock signal is used to determine the next LED driver chip to perform the brightness data. The sampling frequency at which to sample. Furthermore, each bit in the luminance data is sequentially sent from the transmitting end on the rising edge of the clock, and collected by the receiving end on the falling edge of the clock. Therefore, the receiver needs to recover the clock signal before correctly collecting the luminance data. The recovery method is that before transmitting the luminance data, the transmitting end sends several clock waveforms for luminance data transmission on the data line in advance, and the receiving end uses the built-in high-frequency clock to collect the waveforms. Since the clock waveform is only described by frequency and phase, the receiver can obtain the frequency information by calculating the interval between two consecutive rising edges, and obtain the phase information by collecting the positions of the rising and falling edges. Accordingly, the receiving end can recover the clock signal for data transmission.

In the present invention, the brightness data output by the LED driver chip is not limited to controlling 4 groups of LED light-emitting elements. In the prior art, the LED driver chip in the LED display device integrated circuit is generally placed in 4 groups of LED light-emitting elements Therefore, for the convenience of wiring the LED driver chip, the LED driver chip generally only controls the 4 groups of LED light-emitting elements closest to it. According to the technology of the present invention, when the LED driver chip is used to control more groups of LED light-emitting elements, it is only necessary to add the brightness control data of the corresponding LED element to the brightness data input on the data line, and extend the corresponding length of the gate line. The duration of the strobe signal is sufficient.

The above is only a specific implementation case of the present invention, and the scope of protection of the present invention is not limited thereto. Any skilled person familiar with the technology should modify or replace the present invention within the technical specifications described in the present invention. Within the protection scope of the present invention.

Claims

A drive control device for an LED display, characterized in that the drive control device includes an array of multiple LED drive control chips, and the LED drive control chip includes an enabling pin, a data pin and multiple brightness control pins;

In the array composed of a plurality of LED drive control chips, the enable pins of the LED drive control chips in each row of the array are connected to form the gate lines of the LED drive control chips in the row, and the LED drive control chips in each column The data pins of the chip are connected to form the data line of the LED drive control chip;

When a clock signal is input on the gate line, all the LED drive control chips on the gate line are gated, and can receive the brightness data input on the data line for controlling the brightness of the LED light-emitting element; the brightness The data includes multiple sets of data, and each set of data controls the brightness of a corresponding group of LED light-emitting elements through a corresponding brightness control pin.
The drive control device according to claim 1, wherein the LED drive control chip uses the same clock frequency as that on the gate line to sample the luminance data information on the data pin, so as to sequentially know the multiple channels it controls Brightness data of LED light-emitting components.
A drive control device for LED display screens, the drive control device includes an array composed of a plurality of LED drive control chips, the LED drive control chip includes an enable pin, a data pin and a plurality of brightness control pin;

In the array composed of a plurality of LED drive control chips, the enable pins of the LED drive control chips in each row of the array are connected to form the gate lines of the LED drive control chips in the row, and the LED drive control chips in each column The data pins of the chip are connected to form the data line of the LED drive control chip;

When a high-level signal is input on the gate line, all the LED drive control chips on the gate line are gated, and can receive the brightness data input on the data line for controlling the brightness of the LED light-emitting element; The brightness data includes multiple sets of data, and each set of data controls the brightness of a corresponding group of LED light-emitting elements through a corresponding brightness control pin;

The starting position of each group of data also includes an auxiliary clock signal.
The drive control device according to claim 3, wherein the LED drive control chip uses the clock frequency of the auxiliary clock signal at each data start position to sample the brightness data information on the data pins, so as to know the brightness data information sequentially. Control the brightness data of LED light-emitting elements of multiple channels.
A driving control method for an LED display, characterized in that the method comprises:

The LED drive control chip is used to form an LED drive control array; the LED drive control chip includes an enabling pin, a data pin and a plurality of brightness control pins;

In the array composed of a plurality of LED drive control chips, the enable pins of the LED drive control chips in each row of the array are connected to form the gate lines of the LED drive control chips in the row, and the LED drive control chips in each column The data pins of the chip are connected to form the data line of the LED drive control chip;

When a clock signal is input on the gate line, all the LED drive control chips on the gate line are gated, and can receive the brightness data input on the data line for controlling the brightness of the LED light-emitting element; the brightness The data includes multiple sets of data, and each set of data controls the brightness of a corresponding group of LED light-emitting elements through a corresponding brightness control pin.
The drive control method according to claim 5, wherein the LED drive control chip uses the same clock frequency as that on the gate line to sample the brightness data information on the data pin, so as to know the multiple channels controlled by it sequentially Brightness data of LED light-emitting components.
The driving control method according to claim 5, characterized in that, when the clock signal selected by a gate line becomes a continuous low level, the gate line to be gated in the next row remains at a low level for a predetermined duration, and the next row When the first rising edge of the clock signal of the strobe line to be strobed arrives, the data line starts to input LED brightness data.
A driving control method for an LED display, characterized in that the method comprises:

The LED drive control chip is used to form an LED drive control array; the LED drive control chip includes an enabling pin, a data pin and a plurality of brightness control pins;

In the array composed of a plurality of LED drive control chips, the enable pins of the LED drive control chips in each row of the array are connected to form the gate lines of the LED drive control chips in the row, and the LED drive control chips in each column The data pins of the chip are connected to form the data line of the LED drive control chip;

When a high-level signal is input on the gate line, all the LED drive control chips on the gate line are gated, and can receive the brightness data input on the data line for controlling the brightness of the LED light-emitting element; The brightness data includes multiple sets of data, and each set of data controls the brightness of a corresponding group of LED light-emitting elements through a corresponding brightness control pin;

The starting position of each group of data also includes an auxiliary clock signal.
The drive control method according to claim 8, characterized in that, the LED drive control chip uses the clock frequency of the auxiliary clock signal at each data start position to sample the brightness data information on the data pins, so as to know the brightness data information sequentially. Control the brightness data of LED light-emitting elements of multiple channels.
The driving control method according to claim 8, characterized in that, when the clock signal selected by one gate line becomes a continuous low level, the gate line to be gated in the next row remains low for a predetermined duration, and the next row When the signal of the strobe line to be strobed is pulled high, the data line starts to input the LED brightness data.