CN204204379U - A kind ofly environmentally can regulate the LED display system of brightness of display screen by light - Google Patents

Abstract

The utility model discloses and a kind ofly environmentally can regulate the LED display system of brightness of display screen by light, comprise LED array, single-chip microcomputer and LED drive module, LED drive module adopts at least a slice MBI5026CF chip cascade to form, and MBI5026CF chip has an output current control port OE; Described single-chip microcomputer comprises a PWM wave producer module; The input port of described single-chip microcomputer is connected with the data output end of light intensity detecting sensor, and the output current control port OE of all MBI5026CF chips is all connected with the output terminal of described PWM wave producer module.The utility model has and environmentally can adjust the advantage of display screen display brightness flexibly by light intensity.

Description

A kind ofly environmentally can regulate the LED display system of brightness of display screen by light

Technical field

The utility model relates to a kind of LED display system, specifically a kind ofly environmentally can regulate the LED display system of brightness of display screen by light, belongs to electronic technology field.

Background technology

LED display is the plane formula display screen utilizing LED lattice module or pixel cell composition.Because it has the advantages such as bright in luster, brightness is high, the life-span is long, working stability is reliable, be obtained in many industries and apply widely, as AT STATION, LED display is used for Information issued by harbour, market, the public place such as bank.

To the not special requirement of the brightness regulation of display screen in these common application, as long as can clearly show.

But for the display screen in the road condition advisory system in roadside on the road conditions Integrated Information Display System on the dynamic squad car on highway or highway, then the adaptability of screen intensity is regulated and there is higher requirement; Its reason be to allow in above applied environment vehicle driver under any light condition can clear view extremely important to display information, but ambient light intensity can be subject to the impact of several factors, such as weather, time period or pollute other, dust etc., and driver to be enable can clear view display screen just must to be made according to himself display brightness of Perfect Ring environmental light intensity adjustment to the display information of display screen under any situation.

In prior art, to display screen carry out driving adopt and seal in and go out driving chip (its parallel output mouth is connected with the drive singal receiving end of display screen), such as MBI5026CF chip is one of driving chip be most widely used, this type of chip often has the port that can control parallel output port output current, the R_EXT pin of such as MBI5026CF chip, R_EXT pin from access the size stoping different resistance then can regulate MBI5026CF chip output current between ground, thus regulate the brightness of display screen.But because this resistance is fixed resistance, environmentally the resistance of this fixed resistance cannot be regulated by light intensity.Therefore display screen driving control system of the prior art exists and is difficult to environmentally light intensity and adjusts the defect of display screen display brightness flexibly.

Utility model content

For prior art above shortcomings, the purpose of this utility model is: how to provide a kind of environmentally light intensity to adjust the LED display system of display screen display brightness flexibly.

To achieve these goals, the utility model have employed following technical scheme.

Environmentally can regulate a LED display system for brightness of display screen by light, comprise LED array, single-chip microcomputer and LED drive module, it is characterized in that:

The serial data input of described LED drive module is connected with the delivery outlet of single-chip microcomputer, and drive singal receiving port is corresponding is connected with each of LED array respectively for each parallel data output terminal of LED drive module;

Described LED drive module adopts at least a slice MBI5026CF chip cascade to form, and described MBI5026CF chip has an output current control port OE;

Described single-chip microcomputer comprises a PWM wave producer module; The input port of described single-chip microcomputer is connected with the data output end of light intensity detecting sensor, and described light intensity detecting sensor can detect the light intensity of external environment;

The output current control port OE of all MBI5026CF chips is all connected with the output terminal of described PWM wave producer module.

Compared to existing technology, the utility model tool has the following advantages:

In the utility model, the output current control port OE of all MBI5026CF chips is all connected with the output terminal of PWM wave producer module, when the output current control port OE of MBI5026CF chip receives high level, the output driver of chip internal is enabled effectively, drive current is had to flow out from the output port of MBI5026CF chip, and when the output current control port OE of MBI5026CF chip receives low level, it is invalid that the output driver of chip internal is enabled, drive current is not had to flow out from the output port of MBI5026CF chip, the output terminal of the PWM wave producer module in the utility model sends PWM ripple to the output current control port OE of MBI5026CF chip and the output current of MBI5026CF chip just can be made to be in alternately flow out and chop state off, if PWM wave height level duration is long, the electric current supply time is long, display screen brightness is high, if and PWM wave height level duration is short, display screen brightness is just low, and (LED in fact in display screen can replace light on and off, but the words that the time interval replaced is enough short, eye-observation to display frame be but stable), and PWM wave height level duration (dutycycle) can export adjustment according to light intensity detecting sensor, thus compared to existing technology at the R_EXT pin of MBI5026CF chip compared with accessing fixed resistance between ground and be difficult to the technical scheme of the size regulating MBI5026CF chip output current, the utility model has and environmentally can adjust the advantage of display screen display brightness flexibly by light intensity.

Accompanying drawing explanation

Fig. 1 is circuit structure diagram of the present utility model;

Fig. 2 is the multicolored LED array module that can be used for forming its display screen in the utility model.

Embodiment

Below in conjunction with the drawings and specific embodiments, the utility model is described in further detail.

As shown in Figure 1, a kind ofly environmentally the LED display system of brightness of display screen be can regulate by light, LED array, single-chip microcomputer and LED drive module comprised;

The serial data input of LED drive module is connected with the delivery outlet of single-chip microcomputer, and drive singal receiving port is corresponding is connected with each of LED array respectively for each parallel data output terminal of LED drive module;

LED drive module adopts at least a slice MBI5026CF chip cascade to form.

MBI5026CF chip is a similar 74595 seals in and go out (1 road serial input passage, 1 road serial output channel, 16 road parallel output passages) LED drive chip, its principal feature is: (1) has 16 road constant current output passages; (2) output current can be adjusted by the resistance that its R_EXT pin connects (output current 5-90mA); (3) it also has an output enable end OE, and Enable Pin turns off then inner output driver and turns off, and output current cannot export;

Particularly the Serial output mouth SDO of first piece of MBI5026CF chip is connected with the serial input mouth SDI of second piece of MBI5026CF chip, so just output channel can be expanded to 32 passages, single-chip microcomputer is sent in a serial fashion by needing the data being used for showing from the output port of one position, and the output that can walk abreast in above-mentioned 32 output channels is for driving corresponding LED.

If 32 parallel channels still can not satisfy the demands and can also increase MBI5026CF chip further and expand.If n block MBI5026CF chip cascade together, 16 × n bit parallel drive singal altogether can be formed.

Single-chip microcomputer comprises a PWM wave producer module;

Single-chip microcomputer in the utility model adopts MSP430G2553 chip.The PWM wave producer module comprised in single-chip microcomputer realizes in the following way:

The timer of MSP430G2553 chip not only can complete accurate timing, can also produce PWM wave form output, and usually, the PWM of its timer exports 8 kinds of patterns, and the PWM wave amplitude that in single-chip microcomputer, PWM wave producer module produces is 3.6V.

The input port of described single-chip microcomputer is connected with the data output end of light intensity detecting sensor, and light intensity detecting sensor can detect the light intensity of external environment;

The output current control port OE of all MBI5026CF chips is all connected with the output terminal of described PWM wave producer module.

Principle of work of the present utility model is as follows:

Data are sent into single-chip microcomputer after detecting the light intensity of external environment by light intensity detecting sensor, single-chip microcomputer according to the reflection ambient light line strength received data point reuse single-chip microcomputer in the dutycycle of pwm signal of PWM wave producer module generation.

The output terminal of PWM wave producer module sends PWM ripple to the output current control port OE of MBI5026CF chip and the output current of MBI5026CF chip just can be made to be in alternately flow out and chop state off, if PWM wave height level duration is long, the electric current supply time is long, display screen brightness is high, if and PWM wave height level duration is short, display screen brightness is just low, and (LED in fact in display screen can replace light on and off, but the words that the time interval replaced is enough short, eye-observation to display frame be but stable), and PWM wave height level duration (dutycycle) can export adjustment according to light intensity detecting sensor, thus the adjustment to display screen brightness is achieved.

In LED display curtain, the drive singal of any one LED is all sent in a serial fashion by single-chip microcomputer in above process, then transfer to after parallel data through LED drive module and send to drive corresponding LED, it is to be noted that the LED display curtain that the utility model adopts is the screen (that is to say that line is all interconnective with positive source) not needing line scan signals to drive, it can certainly be color/graphics, the LED screen that multicolored LED array module such as shown in Fig. 2 forms, but no matter adopt the concrete means of its adjusting screen brightness of which kind of screen to be all realized by the OE pin of control MBI5026CF chip, instead of control its R_EXT pin, regulate the output current size of MBI5026CF chip.

Finally illustrate, above embodiment is only in order to illustrate technical side of the present utility model.Case and unrestricted, although be described in detail the utility model with reference to preferred embodiment, those of ordinary skill in the art is to be understood that, can modify to the technical solution of the utility model or equivalent replacement, and not departing from aim and the scope of technical solutions of the utility model, it all should be encompassed in the middle of right of the present utility model.

Claims (1)

1. environmentally can regulate a LED display system for brightness of display screen by light, comprise LED array, single-chip microcomputer and LED drive module, it is characterized in that:

The serial data input of described LED drive module is connected with the delivery outlet of single-chip microcomputer, and drive singal receiving port is corresponding is connected with each of LED array respectively for each parallel data output terminal of LED drive module;

Described LED drive module adopts at least a slice MBI5026CF chip cascade to form, and described MBI5026CF chip has an output current control port OE;

Described single-chip microcomputer comprises a PWM wave producer module; The input port of described single-chip microcomputer is connected with the data output end of light intensity detecting sensor, and described light intensity detecting sensor can detect the light intensity of external environment;

The output current control port OE of all MBI5026CF chips is all connected with the output terminal of described PWM wave producer module.