大屏幕顯示系統(tǒng)的研究-外文文獻翻譯

1、大屏幕顯示系統(tǒng)的研究 LED 的發(fā)展 隨著計算機技術(shù)的高速發(fā)展，LED屏幕顯示系統(tǒng)作為繼電視、廣播、報紙、雜志 之后的“第五大媒體”正快速步入社會生活的各個方面。它集微電子技術(shù)、計算機技 術(shù)、信息處理技術(shù)于一體，可以將信息通過文字、圖案、動畫及視頻四種形式顯示出 來。與電視墻、磁翻板等媒體相比，LED大屏幕顯示系統(tǒng)具有圖案美觀、色彩亮麗； 圖案、色彩變化豐富、快速；低功耗、長壽命、使用成本低、工作穩(wěn)定可靠等特點。 它顯示的圖文視角大、視距遠，因而已廣泛應(yīng)用于大型廣場、商業(yè)廣告、體育場館、 信息傳播、新聞發(fā)布、證券交易；它還應(yīng)用于工業(yè)控制和工業(yè)調(diào)動系統(tǒng)，便于把各種 參數(shù)、報警點、工藝流程顯示得更

2、加清晰完美，可以滿足不同環(huán)境的需要。LED顯示 屏是一種利用計算機和復(fù)雜數(shù)字信號處理的電子廣告宣傳屏。 它的屏體部分由微處理 器（主要是單片機） 和驅(qū)動電路控制運行， 顯示的圖像或文字由計算機編輯軟件編輯 獲得。由于LED顯示屏這種新一代信息顯示設(shè)備具有顯示圖案穩(wěn)定、功耗低、壽命長 等特點， 而且它綜合了各種信息顯示設(shè)備的長處， 并且克服了自身的不足， 特別是由 于一幅顯示屏可以顯示不同的內(nèi)容， 顯示方式豐富。 所以在公共場合， 它具有強烈的 廣告宣傳和信息傳遞效果，日趨在固體顯示中占主導(dǎo)地位。LED顯示屏的發(fā)展前景極 為廣闊，目前正朝著更高亮度、 更高耐氣候性、 更高的發(fā)光密度、 更高的發(fā)光

3、均勻性、 可靠性、全色化方向發(fā)展。由不同材料的半導(dǎo)體組成能發(fā)出不同色彩的 LED晶點。目 前應(yīng)用最廣的是紅色、綠色、黃色 LED而藍色和純綠色LED的開發(fā)已經(jīng)達到了實用 階段。 LED 顯示屏的分類 LED顯示屏是多種技術(shù)綜合應(yīng)用的產(chǎn)品，涉及光電子學(xué)、半導(dǎo)體器件、數(shù)字電子 電路、大規(guī)模集成電路、單片機及微機等各個方面，既有硬件又有軟件。LED顯示屏 是作為廣播、電視、報紙、雜志之后的又一新傳播媒體。目前 LED顯示屏根據(jù)使用場 所不同， 可以分為室外屏和室內(nèi)屏兩種， 其主要區(qū)別是發(fā)光管的發(fā)光亮度不同。 而根 據(jù)所顯示的內(nèi)容不同也可以分為圖像屏和文字屏兩種， 圖像屏可以顯示圖像以及多媒 體，而文

4、字屏則主要顯示文字或簡單的固定圖像。 顯示圖像的多媒體室外屏是投資巨 大（高達數(shù)百萬 ）的大型高檔設(shè)備， 主要應(yīng)用在大型公共場所、 形象工程和一些重要場 所。LED顯示屏的應(yīng)用涉及到社會經(jīng)濟的許多領(lǐng)域，已經(jīng)遍及交通、證券、電信、廣 告、宣傳等各個方面。 LED顯示屏的發(fā)展趨勢 目前LED顯示屏的顯示向更高亮度、更高耐氣候性、更高的發(fā)光均勻性、更高的 可靠性、全色化、多媒體方向發(fā)展，系統(tǒng)的運行、操作與維護也向集成化、網(wǎng)絡(luò)化、 智能化方向發(fā)展。二十一世紀(jì)的顯示技術(shù)將是平板顯示的時代，LED顯示屏作為平板 顯示的主導(dǎo)產(chǎn)品之一將有更大的發(fā)展。 1.高亮度、全彩化藍色及綠色超高亮度LED產(chǎn)品出現(xiàn)以來，成

5、本逐年快速降低， 使LED全彩色顯示屏產(chǎn)品成本下降，推廣速度加快。同時，隨著控制技術(shù)的發(fā)展和 LED顯示屏體穩(wěn)定性的提高，全彩色 LED顯示屏的亮度、色彩、白平衡均達到比較理 想的效果，完全可以滿足戶外全天候的環(huán)境條件要求，而且圖像更清晰、更細(xì)膩、更 亮麗。 2標(biāo)準(zhǔn)化、規(guī)范化材料、技術(shù)的成熟及市場價格基本均衡之后，LED顯示屏的 標(biāo)準(zhǔn)化和規(guī)范化將成為LED顯示屏發(fā)展的一個趨勢。近幾年業(yè)內(nèi)的發(fā)展中，幾番價格 回落調(diào)整達到基本均衡后， 產(chǎn)品質(zhì)量、 系統(tǒng)的可靠性等將成為主要的競爭因素， 這就 對LED顯示屏的標(biāo)準(zhǔn)化和規(guī)范化有了較高的要求。行業(yè)規(guī)范和標(biāo)準(zhǔn)體系的形成， IS09000系列標(biāo)準(zhǔn)的應(yīng)用，使L

6、ED顯示屏行業(yè)的發(fā)展趨于有序。 3產(chǎn)品結(jié)構(gòu)多樣化隨著信息化社會的形成，信息領(lǐng)域愈加廣泛，LED顯示屏的 應(yīng)用前景更為廣闊。預(yù)計大型或超大型 LED顯示屏為主流產(chǎn)品的局面將會發(fā)生改變， 適合于服務(wù)行業(yè)特點和專業(yè)性要求的小型 LED顯示屏?xí)休^大提高，面向信息服務(wù)領(lǐng) 域的LED顯示屏產(chǎn)品門類和品種體系將更加豐富，部分潛在市場需求和應(yīng)用領(lǐng)域?qū)?有所突破，如公共交通、停車場、餐飲、醫(yī)院等綜合服務(wù)方面的信息顯示屏需求量將 有更大的提高。 涉及思路及工作原理 本系統(tǒng)根據(jù)經(jīng)典的電路設(shè)計思路， 采用自下而上的設(shè)計方法， 從顯示板到驅(qū)動板， 再到控制板，進行硬件編程，調(diào)試成功后接電源板，最后完成數(shù)據(jù)傳輸板與P

7、C機相 連接，進行PC軟件編程，完成顯示數(shù)據(jù)的生成、提取、處理、傳輸以及顯示效果的 實時控制。每個模塊采用8個LED點陣以行掃描形式點亮各行的紅、綠、紅綠燈，顯 示文字和圖像。LED點陣的驅(qū)動、譯碼、鎖存等由控制板的數(shù)字電路負(fù)責(zé)。其數(shù)據(jù)由 單片機從存儲器中讀取，同時單片機采用中斷方式，通過RS-232數(shù)據(jù)線與PC機進行 雙向通信，從PC機獲取命令或數(shù)據(jù)，并按命令執(zhí)行動作或者存儲數(shù)據(jù)。 而PC機不但 與多個單片機進行多機串口通信， 還要負(fù)責(zé)文字錄入和排版， 生成點陣數(shù)據(jù)或者命令 字，實現(xiàn)人機交互功能。 工作原理 本文設(shè)計的大型LED顯示屏由雙基色點陣LED組合而成，采用逐行掃描的顯示方 式顯示紅

8、、綠、黃三種顏色的任意點陣信息。顯示模塊采用逐行掃描顯示的方式，其 控制系統(tǒng)以單片機 AT89C52為核心，采用74HC154譯碼芯片，利用鎖存器 74HC595 驅(qū)動顯示模塊，同時擴展串口中斷與上位 PC機進行多機通信。通過對單片機編程實 現(xiàn)顯示屏的多種動畫模式顯示：向左滾屏，向右滾屏，向上滾屏，向下滾屏，向左上 滾屏， 向右上滾屏， 向左拉幕， 向右拉幕， 向上拉幕， 向下拉幕， 向右移， 從左向右、 依次點亮，從中間到兩邊、依次點亮。動畫速度可調(diào)：分為100檔，最低為 1 速，最 高為 100 速。圖案顏色多樣：背景無色、文字紅 / 綠/ 黃色，背景紅色、文字無 / 黃/ 綠色，背景綠色

9、、文字無 /黃/ 紅色，背景黃色，文字無 / 紅/ 綠色。另外，還增加了幾 十種霓虹燈效果動畫。 PC 機上的顯示控制軟件可以實現(xiàn)漢字錄入、字體選擇、字號 更改等功能，并且在進行數(shù)據(jù)處理后，可以在左側(cè)模擬演示整體效果，同時“所見即 所得”的顯示在下方預(yù)覽區(qū)域。另外，該控制軟件還具有文本選定、鼠標(biāo)定位、坐標(biāo) 追蹤、時間日期等附加功能。PC機通過RS-232接口實現(xiàn)與顯示部分的單片機的通信， 利用單片機串口中斷實時接收和發(fā)送數(shù)據(jù)信息。 在系統(tǒng)設(shè)計中還兼顧了單片機的抗干 擾能力，有效地提高了系統(tǒng)運行的可靠性。 發(fā)光二級管特性 發(fā)光二極管 (light emitting diode,LED)，是一種把

10、電能變成光能的特種器件， 當(dāng)電流達到門限電流時，發(fā)光二極管導(dǎo)通，隨著電流的通過，產(chǎn)生可見光。發(fā)光二極 管的結(jié)構(gòu)主要由PN結(jié)芯片、電極和光學(xué)系統(tǒng)構(gòu)成。當(dāng)在 PN結(jié)上加以正向電壓之后， P區(qū)的空穴注入至N區(qū)，N區(qū)的電子注入至P區(qū)，相互注入的電子與空穴相遇后即產(chǎn) 生復(fù)合，這些少數(shù)載流子在 PN結(jié)的注入和復(fù)合中產(chǎn)生輻射而發(fā)光。它是自發(fā)輻射發(fā) 光，不需要較高的注入電流產(chǎn)生粒子數(shù)反轉(zhuǎn)分布， 也不需要光學(xué)諧振腔， 發(fā)射的是非 相干光。描述LED的特性有許多參數(shù)，這些參數(shù)之間的關(guān)系呈現(xiàn)非線性。因此，用特 性曲線來描述這些關(guān)系，在工程應(yīng)用中更具有使用價值。 LED器件的驅(qū)動 從LED器件的發(fā)光機理可以知道，當(dāng)向

11、LED器件施加正向電壓時，流過器件的正 向電流使其發(fā)光。因此LED的驅(qū)動就是要使它的PN結(jié)處于正向偏置，同時為了控制 它的發(fā)光強度， 還要解決正向電流的調(diào)節(jié)問題。 具體的驅(qū)動方式有直流驅(qū)動、 恒流驅(qū) 動、脈沖驅(qū)動和掃描驅(qū)動等，本系統(tǒng)中 LED器件的驅(qū)動為掃描驅(qū)動。 1 直流驅(qū)動。直流驅(qū)動是最簡單的驅(qū)動方法。LED的工作點由電源電壓VCC串 聯(lián)電阻R和LED器件的伏安特性共同決定。這種驅(qū)動方式適合于LED器件較少，發(fā)光 強度恒定的情況。例如公交車上使用的用來固定顯示“ XX路”字樣的顯示屏。 2 恒流驅(qū)動。由于LED器件的正向特性較陡，加上器件的分散性，使得在同樣 電源電壓和同樣限流電阻的情況下

12、， 各器件的正向電流并不相同， 從而引起發(fā)光強度 的差異。若對LED器件進行恒流驅(qū)動，只要恒流值相同，發(fā)光強度就比較接近。晶體 管的輸出特性具有恒流特性，所以可以用晶體管驅(qū)動LED。 3脈沖驅(qū)動。利用人眼的視覺惰性，采用向 LED器件重復(fù)通斷電的方式使之點 燃，就是脈沖驅(qū)動方式。脈沖驅(qū)動主要有兩個方面的應(yīng)用：掃描驅(qū)動和占空比驅(qū)動。 掃描驅(qū)動的主要目的是節(jié)約驅(qū)動器，簡化電路。采用這種方式時應(yīng)該注意兩個問題 : 確定脈沖電流幅值和選擇重復(fù)頻率。 首先，要想獲得與直流驅(qū)動方式相當(dāng)?shù)陌l(fā)光強度， 脈沖驅(qū)動電流的平均值就應(yīng)該與直流驅(qū)動的電流值相同。 4 掃描驅(qū)動。掃描驅(qū)動通過數(shù)字邏輯電路，使若干 LED器

13、件輪流導(dǎo)通，用以節(jié) 省控制驅(qū)動電路。LED顯示屏將發(fā)光燈按行按列布置，驅(qū)動時也按行按列驅(qū)動。在掃 描驅(qū)動方式下可以按行掃描，按列控制；也可以按列掃描，按行控制。所謂“掃描” 的含義，就是指一行一行地循環(huán)接通整行的 LED器件，而不管這一行的哪一列的 LED 器件是否應(yīng)該點亮，具體某一列的LED器件是否應(yīng)該點亮，則由所謂的列控制電路來 負(fù)責(zé)。 The research of the large screen display systems Led development Along with computer technologys high speed development, LED (Li

14、ght Emitting Diode) the screen display system takes after the television, the broadcast, the newspaper, the magazine “ thefifth big media”marches into the social life fast each aspect. Its collection microelectronic technology, the computer technology, the information processing and management techn

15、ology in a body, may the information through the writing, the design, the animation and the video frequency four forms demonstrates. With media and so on bank of television monitors, magnetism vane compares, the LED large screen display system has the design to be artistic, the color is sharp; The d

16、esign, the color change are rich, are fast; The low power loss, the long life, the use cost low, work stably reliable and so on characteristics. It demonstrated the chart article angle of view is big, the apparent distance is far, thus has widely applied in the large-scale square, the commercial adv

17、ertizing, the sports complexes, the information dissemination, the news issue, the securities trading; It also applies in the industrial control and the industry reassignment system, is advantageouseach kind of parameter, the alarm point, the technical process demonstratesclearly perfect, may satisf

18、y the different environment the need. The LED display monitor is one kind of use computer and the complex digital signal processing electron advertisements propaganda screen. Its screen body part by the microprocessor (is mainly monolithic integrated circuit) and the driving circuit control movement

19、, demonstrated the image or the writing obtain by the computer edition software editor. Because the LED display monitor this kind of new generation information graphic display device has the demonstration design to be stable, the power loss is low, life long and so on characteristics, moreover it sy

20、nthesized each kind of information graphic display devices strong point, and has overcome own insufficiency, because specially a display monitor may demonstrate that the different content, the display mode is rich. Therefore in the public area, it has the intense advertisements propaganda and the in

21、formation transmission effect, already in the solid demonstratedday by day occupies the dominant position. The LED display monitors prospects for development are extremely broad, at present toward the high luminance, a higher weather fastness, the higher luminous density, the higher illumination uni

22、formity, the reliability, the panchromatic direction is developing. Is composed of the different materials semiconductor can send out the different color the LED crystal spot. At present what applies is broadest is red, the green, yellow LED. But the blue color and the pure green LED development had

23、 already achieved the practical stage. LED display monitors classification LED display monitors classified LED display monitor is many kinds of technical synthesis application product, involves photoelectronics, the semiconductor device, the digit electronic circuit, the large scale integrated circu

24、it, the monolithic integrated circuit and the microcomputer and so on each aspect, both has the hardware and to have software. After the LED display monitor is takes the broadcast, the television, the newspaper,the magazine another new communication media. At present the LED display monitor basis us

25、es the place to be different, may divide into the outdoor screen and the indoor screen two kinds, its main difference is photo tubes illumination brightness is different. But acts according to the content which demonstrated different also to be possible to divide into the image screen and the writin

26、g screen two kinds, the image screen may the display image as well as multimedia, but writing screen main demonstration writing or simple fixed image. Display images multimedia outdoor screens are the investment huge (reaches as high as several millions) the large-scale upscale equipment, main appli

27、cation in large-scale public place, image project and some important places. The LED display monitors application involves to social economy many domains, already spread the transportation, the negotiable securities, the telecommunication, the advertisement, the propaganda and so on each aspect. LED

28、 display monitors trend of development At present the LED display monitors demonstration to the high luminance, a higher weather fastness, the higher illumination uniformity, a higher reliability, the panchromatic, the multimedia directions develops, systems movement, the operation and the maintenan

29、ce also to the integration, the network, the intellectualized direction develop. The 21st centurys display technology will be the panel display time, the LED display monitor takes one of panel display leadership products to have a bigger development. 1. since the high luminance, entire color blue co

30、lor and the green superelevation brightness LED product has appeared, the cost reduces fast year by year, causes the LED entire colored display monitor product cost to drop, the promoted speed speeds up. At the same time, along with control technologys development and the LED display monitor body st

31、able enhancement, the entire colored LED display monitors brightness, the color, white balanced achieves the quite ideal effect, definitely may satisfy the outdoors all-weather environmental condition request, moreover the image is clearer, is more exquisite, is sharper. 2. after standardization, st

32、andardized material, technology mature and market price basic balanced, the LED display monitors standardization and the standardization will become a tendency which the LED display monitor develops. In recent years industry in development, after several price recedesthe adjustment achieves basicall

33、y balanced, the product quality, the system reliable and so on will become the main competition factor, this had the high request to the LED display monitors standardization and the standardization. Profession standard and standard systems formation, IS09000 series standard application, causes the L

34、ED display monitor profession the development tends the order. 3. the product mix diversification along with the informationization societys formation, the information field is even more widespread, the LED display monitors application prospect is broader. It is estimated that large-scale or the ult

35、ra-large LED display monitor will have the change for the mainstream products aspect, will suit can have in the service industry characteristic and the specialized request small LED display monitor enhances greatly, will be richer face the information service domains LED display monitor product clas

36、s and the variety system, the part potential market demand and the application domain will have the breakthrough, like the mass transit, the parking lot, the dining, the hospital and so on comprehension service aspects information display monitor demand will have a bigger enhancement. Involves the m

37、entality and the principle of work This system basis classics circuit design mentality, uses the design method from bottom to top, from the display panel to the actuation board, arrives at the control panel again, carries on the hardware programming, after debugging successfully, receives a telegram

38、 the source plate, finally completes the data transmission board and PC machine connects, carries on the PC software programming, completes the demonstration data the production, the extraction, processing, the transmission as well as the demonstration effect real-time control. Each module uses 8 LE

39、D lattices to lighten each line by the line scan form red, green, the traffic light, the demonstration writing and the image. The LED lattices actuation, the decoding, the lock save and so on to be responsible by control panels digital circuit. Its data reads by the monolithic integrated circuit fro

40、m the memory, simultaneously the monolithic integrated circuit uses the interrupt mode, carries on the two-way communication through the RS-232 data line and PC machine, from the PC machine gain order or the data, and carries out the movement or the stored datum according to the order. Not only but

41、PC machine carries on many machine serial port correspondences with many monolithic integrated circuits, but must be responsible for the writing input and the typesetting, the production lattice data or the order character, realize the man-machine interaction function. Principle of work this article

42、 designs the large-scale LED display monitor becomes by the double primary color lattice LED combination, uses the line-by-line scanning the display mode to demonstrate red, green, the yellow three kind of color random lattice information. The display module uses the line-by-line scanning demonstrat

43、ion the way, its control system take monolithic integrated circuit AT89C52 as a core, uses 74HC154 memories to take the data-carrier storage, actuates 8*8 using latch 74HC595 and 8 group of line driver 2083The LED display module, simultaneously opens the serial port interrupt and superior PC machine

44、 carries on many machine correspondences.Through realizes display monitors many kinds of animation pattern to the monolithic integrated circuit programming to demonstrate:Rolls the screen toward left, rolls the screen toward right, rolls the screen upwardly, rolls the screen downward, on rolls the s

45、creen toward left, on rolls the screen toward right, to the Zola curtain, pulls the curtain toward right, pulls the curtain upwardly, pulls the curtain downward, to the right lateral, lightens in turn from left to right, from among to two nearby, lightens in turn. Animation speed adjustable: Divides

46、 into 100 grades, lowest is 1 fast, highest is 100 fast. The pattern color is diverse: The background achromatic color, the writing red/green/yellow, the background is red, the writing does not have/the yellow/green, the background green, the writing does not have/yellow/red, the background yellow,

47、the writing does not have/the red/green. Moreover, but also increased several dozens kind of neon light effect animation. The PC machine on display control software may realize functions and so on Chinese character input, typeface choice, words change, and after carrying on the data processing, may

48、in left side simulate the demonstration whole effect, simultaneously“ sees namely obtained ” demonstrati underneath preview region. Moreover, this control software also has additional functions and so on text designation, mouse localization, coordinate tracing, time date. PC machine realizes through

49、 the RS-232 connection with the demonstration part monolithic integrated circuits correspondence, interrupts the real-time receive and the transmission data message using the monolithic integrated circuit serial port. Has also given dual attention to monolithic integrated circuits antigambling abili

50、ty in the system design, enhanced the systems operation reliability effectively. Shines the second-level tube characteristic The light emitter diode (light emitting diode, LED), is one kind turns the electrical energy the energy of light the special component, when the electric current achieves the

51、threshold current, the light emitter diode breakover, along with electric current passing, produces the visible light. Light emitter diodes structure mainly ties the chip, the electrode and the optical system constitution by PN. After PN ties performs the direct voltage, P areashole injection to the

52、 N area, N areas electron-injection to the P area, the electron which and the hole meet, pours into after mutually namely produces compound, these minority carriers injection which ties in PN produce the radiation with compound to shine. It is the original radiation illumination, does not need the h

53、igh injection current to have the granule number reverse distribution, also does not need the optical resonator, the launch right and wrong coherent light. Describes the LED characteristic to have many parameters, between these parameters relations present misalignment. Therefore, describes these re

54、lations with the characteristic curve, has the use value in the project application. LED components actuation May know from the LED components illumination mechanism, when exerts the direct voltage to the LED component, winds through components forward current to cause its illumination. Therefore th

55、e LED actuation is must make its PN knot to be in the forward bias, simultaneously to control its luminous intensity, but must solve the forward current adjustment problem. The concrete drive type has 9 and so on direct-current actuation, constant flow actuation, pulse actuation and scanning actuati

56、on, in this system LED components actuation for scanning actuation. 1. direct-current actuation. The direct-current actuation is the simple the actuation method. The LED operating point by supply voltage VCC, series resistance R and a LED components voltage-current characteristic decided together. T

57、his drive type suits in the LED component are few, luminous intensity constant situation. For example on the public transportation uses for to demonstrate the “XX road fixedly ”the inscription display monitor. 2. constant flow actuation. Is steep as a result of the LED components forward characteristic, in addition components dispersivity, causes in same the supply voltage and in the same limiting resi