Evolution of screen display technology

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compile ：Alex

Technical review ： Zhao Jun

Depending on the wild #010#

every single day , We're all on TV 、 Watch streaming media content on the screen of computers, mobile phones and other devices . With the continuous development and update of hardware equipment and streaming media technology , Screen display technology is also evolving . today , Let us follow the footsteps of history , Let's review the important milestones in the development of screen display technology .

CRT The advent of

1869 year , German physicist Julius Plücker and Johann Wilhelm Hittorf Cathode rays were observed for the first time .1897 year , German physicist Karl Ferdinand Braun（Braun It's also 1909 Nobel Prize winner in physics ） Invented CRT（cathode-ray tube, crt ）, It was originally called the Braun tube （ Braun tube）, It is one of the earliest electronic displays in the world .

One 14 Inches of color CRT（ source ：Blue tooth7/Wikimedia Commons）

CRT It is a special vacuum tube , It contains one or more electron guns , The electron beam emitted by the electron gun strikes the fluorescent screen , To show the image . Early television 、 The computer 、 Automatic teller machines 、 The camera 、 Monitors and radar displays are built-in CRT.

1907 year , Russian scientists Boris Rosing （ With the inventor of television Vladimir Zworykin Working together ） Use CRT A brief geometric image is transmitted to the TV screen .Rosing This initiative also made him an important inventor in the field of television . After that ,CRT Technology is developing , And in 1922 First commercialized in . stay LED、 Plasma and OLED Before the advent of technology ,CRT It has been used as the display of most devices .

Throughout 20 The middle and later period of the century , Cathode ray tubes are widely used in television and computer displays . In the meantime , Manufacturers continue to improve performance and resolution .20 century 70 Most computer monitors in the s could only display green text on a black screen . here we are 1990 year ,IBM Extended graphics array （XGA） The display can be displayed in 800 x 600 Pixel resolution display 1680 Ten thousand colors .

Plasma display （Plasma Display）

1936 year , Hungarian engineer Kálmán Tihanyi This flat panel plasma display system is described in his paper .1964 year , University of Illinois at urbana - champagne Donald Bitzer、 H. Gene Slottow And I was a graduate student at that time Robert Willson Developed the first monochrome plasma display , be used for PLATO Computer system .

Composition of plasma display （ source ：Wikipedia）

The principle of plasma luminescence is to inject inert gas or mercury vapor into a vacuum glass tube , After applying voltage , Make the gas produce plasma effect , Emit ultraviolet light , Excite phosphor to produce visible light , Use the length of excitation time to produce different brightness . Plasma display , Each pixel has three different colors （ Three primary colors ） Produced by a plasma emitter . Because it is lit by each independent illuminant at the same time , So it is very clear . [1]

until 2000 Beginning of the year , Plasma displays are the most popular choice for large flat panel HDTVs . But here's the thing , Because plasma display is prone to image residue , meanwhile , Limited by material and structure , It cannot be reduced in size , So it doesn't apply to computers 、 Tablets and cell phones . This is also the main reason why plasma display fails in the market competition .

To 2013 year , It is low cost LCD transcend , The display quality is faced with expensive but higher contrast OLED Flat panel display competition . Plasma displays have lost almost all their market share . Plasma displays for the U.S. retail market were produced in 2014 In the end , Production in the Chinese market started in 2016 In the end .

Liquid crystal display （LCD） Time

1888 year , Austrian botanist Friedrich Reinitzer In the study of cholesterol benzoate in carrots （Cholesteryl Benzoate） Liquid crystal was discovered accidentally （Liquid Crystals）.

1962 year ,RCA（Radio Corporation of America, American Radio Corporation ） A physical chemist in a laboratory Richard Williams Want to find an alternative CRT Display material of . In the course of his research, he found that , When he applied an electric field to a thin liquid crystal layer , The crystal will form a stripe pattern and enter the nematic state .Richard Later, this research was given to him in RCA Colleague George H. Heilmeier. Through unremitting efforts ,George My team found a way to operate the crystal at room temperature , And invented the first liquid crystal display , On 1968 It was first shown to the world in .

In a calculator LCD Monitor （ source ：Wikipedia）

LCD The structure is to place a liquid crystal cell between two parallel glass substrates , The lower base plate is arranged on the glass TFT（ Thin film transistor ）, A color filter is arranged on the upper substrate glass , adopt TFT The rotation direction of liquid crystal molecules is controlled by changing the signal and voltage on the liquid crystal , So as to control whether the polarized light of each pixel is emitted or not and achieve the purpose of display . [2]

Although the LCD is in 20 century 70 The s has come out （ It was common in calculators at that time 、 watch 、 Clocks and various household appliances ）, But it was not until the 90 It was only in the s that it was widely used . Because of its low power consumption 、 Small size 、 Light weight , So it is widely used in notebook computers . With LCD The continuous improvement of technology ,LCD Screen is becoming more and more popular in computer and TV .2007 year , For the first time in the world, LCD TV has surpassed CRT TV sales .

from LED To OLED

1962 year , General electric engineers Nick Holonyack Invented the world's first visible light LED.1962~1968 During the year , Hewlett Packard Howard C. Borden and Gerald P. Pighini Leading the team has been doing LED R & D work .1969 year 2 month , They launched HP model 5082- 7000 Calculator , It is the first one adopting integrated circuit technology LED equipment , At the same time, it has the first intelligence in the world LED display . HP vs LED The commercialization of has set off a revolution in digital display technology , And for later LED The development of display technology has laid the foundation .

LED yes Light Emitting Diodes For short , namely “ Light-emitting diode ”, Strictly speaking, it is also LCD（ Liquid crystal display ） A kind of . Conventional CCFL（Cold Cathode Fluorescent Lamp, Cold cathode fluorescent lamp, etc ） As LCD The backlight of the device , Can only illuminate the entire screen evenly , Cannot change lighting intensity . Compared with CCFL, LED Backlit LCD The device can use local dimming , So as to produce better contrast and more vivid display , And consume less energy .

LED Signal lamp （ source ：Wikipedia）

because LED Versatility and lighter weight , majority LCD Both smartphones and tablet monitors use LED.

1987 year , On the basis of previous research ,Eastman Kodak Dengqingyun, two chemists of the company, and Steven Van Slyke Jointly developed the first practical OLED equipment .

OLED（Organic Light-emitting Diode）, Also known as “ Organic electroluminescence display ”.OLED It is an electroluminescent device using multilayer organic thin film structure , When an electric current is applied to it , Will emit a bright light . And LCD Different ,OLED No backlight required , At the same time, you can use the light-emitting base layer （ Instead of LCD and LED Glass base used ）, And it has a wider perspective and faster response speed .

The first in the world OLED TV Sony XEL-1（ source ：Wikipedia）

OLED For electroluminescence technology , It's a big step forward . And LED comparison ,OLED Lighter and smaller , And more flexible , It is often used on TV screens 、 Computer monitors and smartphones 、 Handheld game consoles and other devices .

since iPhone X Start using OLED Display start ,OLED Rapidly sweeping the global terminal market , Full screen 、 Folding screen 、 Flexible screens are emerging one after another , It has greatly promoted the development of display technology .

The invention of electronic paper

In the last century 70 years , Xerox Parc The company's Nick Sheridon Developed the world's first electronic paper ——Gyricon.

Electronic paper is a thin piece of film , On it is a layer of electronic ink —— This is a liquid material , There are hundreds of microcapsules about the same size as human hair , Each microcapsule is composed of positively charged particles and negatively charged particles . [3] When a positive or negative electric field is applied to a single electrode , The colored particles with corresponding charges will move to the top or bottom of the capsule , Make the surface of the electronic paper display show a certain color .

E-readers （ source ：Wikipedia）

Same as OLED equally , Electronic paper itself can also emit visible light , At the same time keep as “ paper ” Gloss .

Although electronic paper in the last century 70 It has been developed since the s , But it was not until the 21 It became popular at the beginning of the century . Its most widespread application is e-reader , Like the ones that we see all the time Kindle、BOOX etc. . besides , It is also used for electronic pricing tags 、 Digital signage and some smart phone displays .

DLP technology

DLP（Digital Light Processing） Is the abbreviation of digital optical processing , Its working principle is to digitally process the image signal , Then it is projected through the way of light . This technology has very high image fidelity , Able to project clarity 、 bright 、 A picture with vivid colors , It is mostly used in projector systems . [4]

DLP Projector InFocus IN34（ source ：Wikipedia）

DLP The core of the technology is a device called digital micromirror (DMD,Digital micromirror device) Optical semiconductors , It uses tiny mirrors made of aluminum to reflect light to generate images .DMD Usually called DLP chip , Each chip can contain more than 200 Ten thousand micro mirrors , Less than a fifth the width of human hair . The micro mirrors are arranged in a matrix （ Very much like photo mosaic ）, Each micromirror represents a pixel .

The number of these micro mirrors corresponds to the resolution of the screen .DLP 1080p Technology can provide more than 200 Mega pixels , Achieve real 1920x1080p The resolution of the . There are already 8K Of DLP Projector （ Use 3xDLP）.

DLP Originally by physicists at Texas Instruments Larry Hornbeck On 1987 Annual development .1997 year ,Digital Projection The company launched the first DLP Projector .1998 year , Texas Instruments and Digital Projection Because DLP Technology won the Emmy award that year .

With plasma and LCD Equipment comparison ,DLP Lower equipment prices , And it has a bigger screen , It is also lighter . Maybe you didn't realize ,DLP Technology often appears in your life , It is common in all kinds of projectors （ For training 、 Teaching ）、 Home Theater 、 Video wall 、 Large projection systems such as concerts and press conferences .

These are important milestones in the development of screen display technology . The development of display technology involves microstructure optical materials 、 Advanced manufacturing 、 The fusion of image processing and other technologies , These technologies not only improve the device screen resolution , It also vividly presents the human imagination . We believe that , With the development of hardware equipment and the continuous progress of science and Technology , Display technology will make another breakthrough in innovation .

Sources：

[1] Plasma display screen _ Baidu Encyclopedia (baidu.com)

[2] LCD（ Electronic products, ）_ Baidu Encyclopedia (baidu.com)

[3] Electronic paper _ Baidu Encyclopedia (baidu.com)

[4] DLP The working principle and application fields of the technology - Electronic enthusiast network (elecfans.com)

References:

https://www.thoughtco.com/television-history-cathode-ray-tube-1991459

https://theinventors.org/library/inventors/blcathoderaytube.htm

https://interestingengineering.com/the-world-at-your-fingertips-a-brief-history-of-mobile-display-technology

https://www.sears.com/articles/tvs-electronics/televisions/the-evolution-of-display-technology.html

https://en.wikipedia.org/wiki/Plasma_display#History

https://en.wikipedia.org/wiki/LED_display

https://baike.baidu.com/item/ Electronic paper /7548072?fr=aladdin

https://www.visionect.com/blog/electronic-paper-explained-what-is-it-and-how-does-it-work/

https://www.elecfans.com/d/1808554.html

https://en.wikipedia.org/wiki/Digital_Light_Processing

https://en.wikipedia.org/wiki/Electronic_paper

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