As early as the end of 19, Austrian botanists discovered liquid crystal, that is, a substance has both liquid fluidity and some crystal-like arrangement characteristics.
Under the action of electric field, the arrangement of liquid crystal molecules will change, thus affecting its optical properties. This phenomenon is called electro-optic effect.
Using the electro-optical effect of liquid crystal, British scientists made the first liquid crystal display in the last century.
Linear liquid crystals are widely used in today's liquid crystal displays. If we look at it with a microscope, we will find it is like a cotton swab.
Compared with the traditional CRT, LCD is not only small in size, thin in thickness (14. 1 inch can be only 5cm), light in weight, low in energy consumption (1 to 10 microwatt /CMOS) and low in working voltage (1.5 to 6V).
Because of its many advantages, LCD has entered the field of desktop application since 1998.
The first operational LCD was based on Dynamic Scattering Mode (DSM), which was developed by a team led by George Hailmann of RCA Company.
Hailmann founded Optel Company, which developed a series of liquid crystal displays based on this technology.
1970 12, the rotational nematic field effect of liquid crystal is registered as a patent by Santer and Hoffman-lerouke Central Laboratory in Herfrich, Switzerland.
1969, James Ferguson discovered the rotating nematic field effect of liquid crystal in Ohio University, and registered the same patent in the United States in February of 197 1.
197 1 year, his company (ILIXCO) produced the first LCD based on this feature, which quickly replaced the DSM LCD with poor performance.
1985, this discovery has commercial value. 1973, it was first applied to the digital display of electronic calculators by Japan Shengbao Company.
LCD is the main display device of notebook computers and palmtop computers, and also plays a very important role in projectors, and has gradually penetrated into the desktop display market.
For a long time, the pursuit of more perfect visual enjoyment is the goal pursued by our desktop display equipment. Looking back on the development of display technology, it is not difficult to find that all this revolves around the same theme-"Pursuing better visual comfort for human naked eyes"!
As a new product that has sprung up in recent years, liquid crystal display has completely replaced the bulky CRT display as the mainstream display equipment.
However, the development of LCD is not as smooth as we thought.
Next, let's review the arduous and tortuous road of LCD development with new and old users.
Early development of LCD (1986 ~ 200 1)-high cost restricts its development. In the early days, liquid crystals were mainly used in electronic watches, calculators and other fields.
The LCD we usually talk about is called liquid crystal display in English, which is literally translated into Chinese as crystalline liquid Display for short.
Liquid crystal is an almost completely transparent substance.
Its molecular arrangement determines the path of light passing through the liquid crystal.
In the 1960s, it was found that charging liquid crystal would change its molecular arrangement, which would lead to the distortion or refraction of light, so the idea of inventing liquid crystal display devices came into being.
The world's first liquid crystal display device appeared in the early 1970s and was called TN-LCD (twisted nematic) liquid crystal display.
Although it is monochrome display, it has been extended to the fields of electronic watches and calculators.
Thin fuselage, saving space
Compared with the bulky CRT display, the liquid crystal display only needs one third of the space.
Power saving, no high temperature.
It is a low-power product, and it will not generate heat at all (the main power consumption and heat generation part exists in backlight tubes or LEDs), while CRT displays will inevitably generate high temperature due to imaging technology.
Low radiation is good for health.
The radiation of liquid crystal display is much lower than that of CRT display (only low, not completely without radiation, and electronic products have radiation more or less), which is good news for people who work in front of computers all day.
The picture is soft and does not hurt the eyes.
Different from CRT technology, the LCD screen will not flicker, which can reduce the damage of the monitor to the eyes and make the eyes less tired.
Liquid crystal display is green and environmentally friendly, and its energy consumption is simply too small compared with traditional CRT (17'' power is about 65- 12W). The noise pollution that gradually attracts people's attention has nothing to do with it, because its own working characteristics determine that it will not produce noise (the noise that users like to beat the monitor rhythmically when using the computer is not considered here); Another advantage of LCD is that its calorific value is relatively low, and it won't feel hot when used for a long time, which is incomparable to previous displays. In the past, the monitor was very precious, especially in summer, and the air conditioner and electric fan at home had to serve it to cool it down.
The use of liquid crystal display invisibly reduces the temperature of the atmosphere and helps to prevent the temperature of the atmosphere from rising.
At the same time, reduce radiation and environmental pollution.
Of course, environmental protection will not lose the index of radiation. Although it can't be said that liquid crystal has no radiation at all, compared with the radiation of CRT and daily household appliances, the little radiation of liquid crystal can be ignored.
In fact, the era is still an analog era, and the future era is a digital era in terms of development trend.
Intelligent display operation, digital control and digital display are necessary conditions for future displays.
With the advent of the digital age, digital technology will completely replace analog technology, and liquid crystal display will soon completely replace analog CRT display.
On the other hand, the digital interface of LCD is not popular, and it is far from the application field.
Theoretically, LCD is a pure digital device, and the connection with the computer host should also adopt a digital interface. The advantages of adopting digital interface are self-evident.
Firstly, it can reduce the signal loss and interference in the process of analog-to-digital conversion; Reduce the corresponding conversion circuits and components; Secondly, there is no need to adjust the clock frequency and vector.
The interfaces of most liquid crystal displays in the market are analog interfaces, which have some problems, such as the transmission signal is easily disturbed, the analog-to-digital conversion circuit needs to be added inside the display, and it cannot be upgraded to digital interfaces.
In addition, in order to avoid pixel flicker, the clock frequency and vector must be completely consistent with the analog signal.
In addition, the digital interface of LCD has not yet formed a unified standard, and graphics cards with digital output are rare in the market.
This makes it difficult to give full play to the key advantages of LCD.
This question may not be easy to understand. Let's give an example to illustrate.
Anyone who has used liquid crystal displays knows that liquid crystal displays are prone to image tailing.
Response time is a special index of LCD.
The response time of liquid crystal display refers to the speed at which each pixel of the display reacts to the input signal. If the response time is short, the image tailing phenomenon will not appear when the moving picture is displayed.
This is very important when playing games and watching fast-moving images.
Fast enough response time can ensure the continuity of the picture.
The response time of ordinary liquid crystal displays in the market has made a great breakthrough compared with before, generally around 40 ms
However, with the development of technology, the gap between LCD and CRT has gradually narrowed, and the response time of LCD has been shortened to 5 ms
From the appearance, the LCD is thin and ultra-thin. Compared with the traditional spherical display, its thickness and volume are only half of that of CRT display (for example, ASUS MS series products have an amazing thickness of 1.65cm), which greatly reduces the floor space.
Hong Kong and Tokyo have the highest penetration rate of LCD monitors in the world, and the shipments of LCD monitors in Hong Kong account for 70% of the total shipments of monitors.
It is not difficult to find that most of these places are prosperous and crowded, with high living standards and many office buildings and financial buildings.
In these places, it is an inch of land and gold.
The land price of the space saved by the display is much higher than the price difference between LCD and CRT.
The prosperous areas of some big cities in Chinese mainland also tend to develop in this direction.
This question is actually about your use of the monitor.
As we all know, because liquid crystal molecules themselves cannot emit light, liquid crystal displays need to rely on external light sources to assist in emitting light.
Generally speaking, 140 lumens per square meter is enough.
There is still a gap between the parameter standards of some manufacturers and the actual standards.
It should be explained here that some small-sized LCD monitors were mainly used in notebook computers, and the adjustment of two lights, brightness and contrast were not very good.
The brightness of mainstream desktop LCD can reach 250 lumens to 400 lumens, which has gradually approached the level of CRT.
For most people, if you put CRT and LCD together, you can easily tell the difference between LCD and ordinary CRT in brightness, contrast and color saturation, but in general use, this little difference will not affect your work.
But for professional artists and other jobs that require accurate colors, LCD can't fully meet their job requirements.