What is the best brightness and color temperature adjustment of LCD?

When buying an LCD, you will follow the instructions, you can refer to the tips inside, and generally use the default. Find the following information, I hope it will be useful to the landlord and wish you happiness.

Summary of LCD problems

First, the color article

(Color, brightness, contrast, viewing angle, color temperature) First of all, for any display (CRT/LCD/...), color is always the first! The authenticity and softness of color display give the eyes the most direct feeling! As for why brightness contrast and even viewing angle should be classified as color, there will be an answer below. The color standard of a good LCD is rich and full colors, appropriate brightness and contrast, wide viewing angle and flexible and reasonable adjustment of color/brightness/contrast.

Q 1. 1: Why do two brands of LCDs display the same picture, but they look different?

A 1. 1: The display effect of liquid crystal is determined by panel, control circuit and other aspects. Different liquid crystals adopt different compositions and technologies, and the display effect will definitely be different. In fact, this difference also exists in CRT, such as Tyrone and Dana tube, but liquid crystal is more different from CRT in this respect because of its own characteristics. This has also become the most effective way for us to judge the quality of LCD-displaying the same picture, comparing the effect, and the feeling of our eyes is the most convincing standard.

Q1.2: How many colors can an LCD display? How much worse than CRT?

A 1.2: At present, the relatively strong liquid crystal on the market can directly display about 167000 colors (note that not every model can display so much), while CRT can display infinite colors. This is the congenital deficiency of liquid crystal, but the principle of the two is different. CRT displays a certain color through several adjacent color points, and the color points are only red, green and blue, which gives you an "illusion" after mixing; And each color point of liquid crystal can display 167000 kinds, giving you direct colors. So we can say that LCD is actually very strong in this respect, and CRT has only three colors (psychological yy, hehe).

Q 1.2. 1: For an LCD with 167000 colors, can colors beyond this range be displayed?

A 1.2. 1: For colors that cannot be directly displayed, liquid crystals also have processing methods, such as alternately displaying two colors to create an "illusion" of a new color. In this respect, the process of each manufacturer is different, and some of them are untreated, so the color and richness will be different.

Q 1.3: 16 bit color, 24 bit color, 32 bit color. What is the difference?

A 1.3: In terms of color number, it is obviously the difference between16th power, 2 24th power and 32nd power. From the human eye's perception, 16 bit color can basically meet the display requirements, and looks similar to 24-bit color and 32-bit color. If you study it carefully, you will find that there will be a faint separation line in the display of 16 bit color in a large area of gradient color. In practical application, the most commonly used color is 24-bit color, such as "#80FF2E" in web pages and other places. Looking at pictures with ACDSee, we can see that the color depth of most pictures is 24 bits. As for the 32-bit color, it is added on the basis of 24 bits. It is said that the 8-bit transparent color is added, which is not much different from the 24-bit color, at least our eyes can't tell it apart.

Q 1.4: I use LCD. Is it enough to set 16 bit color in Windows?

A 1.4: of course not! Still set to 32-bit color! According to the above, the number of colors directly displayed by liquid crystal is between 16 and 24, and there are special technologies to enrich the colors. Therefore, setting the LCD display to 16 bit color is actually overqualified, especially those excellent LCDs, which is really a waste of the efforts of manufacturers.

Q 1.5: Are the brightness and contrast parameters as high as possible?

A 1.5: The answer is no, and the brightness and contrast parameters represent the values in extreme cases, which are of little significance to daily application. The values of 400 and 500 are too abstract, and it is still based on the feeling of the eyes, that is, "bright but not dazzling, clear but not vain". I have seen a Qili LCD with a nominal brightness of 400 and a contrast of 500, but the image looks pale and dim. There is also a contrast ratio of Meg above 500, and black is actually darker, which makes the whole feeling very dark. In addition, the nominal parameters of many well-known brands are conservative. For example, a certain brightness of NEC is nominally 280, and it is enough to adjust it to 50% in actual use.

Q 1.5: Why do liquid crystals feel different colors from different angles?

A 1.5: liquid crystal is displayed by refraction, so it inevitably brings the problem of viewing angle, and the color will change when the line of sight is deflected. At present, there are many technologies to increase the viewing angle of LCD. Generally, the horizontal viewing angle is relatively large, because the eyes and display screen are almost horizontal. Therefore, the liquid crystal we see now is basically like this: the color is the best when it is right, it turns pale and gray when it is viewed from left to right, white and light when it is looked down, and black and thick when it is looked up.

Q 1.6: It is said that liquid crystal is not suitable for painting because there are few colors that can be displayed, right?

A 1.6: It used to be like this, but now it has actually become a misunderstanding. The 167000 colors displayed by LCD are enough for human eyes, not to mention that now the images are all processed by software, and it is unnecessary for human eyes to distinguish "#3399FF" from "#3399FE". On the other hand, even if two CRTs display the same color, there are subtle differences. The key reason why LCD is not suitable for cooperative drawing is the viewing angle! For graphic workers, it is the most deadly to look at one color on the left and change another color on the right.

Q 1.6. 1: Although I am not a professional graphic worker, I often need to deal with some pictures in my work. Can I use the LCD?

A 1.6. 1: Yes, but choose the one with good color and large perspective. If the funds are sufficient, you can consider the recognized excellent EIZO. If you are frugal, you can use Youpai, and so can LG. The models of Samsung and Philips are very different, so you can choose the mid-range one.

Q 1.7: Two brands and models of LCD monitors use the same panel. Is the display effect the same?

A 1.7: No, there may even be obvious differences. Although the panel is the main part, the quality of control circuit and optimization technology also directly affects the display quality, which is manifested as the difference of color. For example, some models of BenQ and AUO use the AUO panel, but the display effect is different. BenQ is lighter and a little transparent, while AUO is more colorful.

Q 1.8: How to set the color temperature of liquid crystal?

A 1.8: Due to different principles, the colors displayed by LCD and CRT are different at the same color temperature. For most orientals, it is more comfortable to set the CRT to 9300K and the LCD to 6500K, which of course varies from person to person. It is best to adjust RGB independently. Anyway, as long as you look comfortable.

Q 1.9: I went to the store to buy an LCD. How can I choose a better color?

A 1.9: The simplest thing is to display the same image to see which one is most comfortable. Sometimes without this condition, you can ask to display an XP background. Another effective method is to display a large area of gradient color to see if the transition is smooth. It is convenient to judge the perspective, as long as you look at it from different angles. Don't worry too much about brightness and contrast, just look at the adjustable range, because the brightness and contrast of LCD with good color are definitely good.

Second, speed.

(Response time, refresh rate, frame rate)

This is a hot topic being discussed everywhere, and it is necessary to introduce some concepts (in the case of using analog signals) before studying it:

Response time The time required for the liquid crystal cell to change from one color to another. The typical response time given by general manufacturers is the sum of rise time tr and fall time tf. As for which tr or tf stands for black to white, different types of panels are not exactly the same, so I won't go into details here. Now the common response time is 25ms and 16ms.

Wait, 25ms means that the whole process of LCD box from black to white to black takes 25 ms.

The frequency at which the refresh rate monitor updates the screen, such as 75Hz, means that it updates 75 times in 1 second. This value is given by the graphics card. If the value given by the graphics card is too high, the display will turn black or display an error message.

Frame rate for movies, frame rate refers to the number of pictures played per second; For 3D games, the frame rate is the number of frames generated by the graphics card per second, which is commonly referred to as the FPS value. In this paper, for the convenience of explanation, the frame rate refers to the FPS value.

A technology in vertical synchronous 3D processing that allows the graphics card to synchronously follow the refresh rate of the display to generate a picture. For example, if the refresh rate is 60Hz, the graphics card will generate 60 pictures per second, which will be provided synchronously every time the monitor is refreshed. Even if the graphics card is as strong as 500 FPS, it is still only 60; If you say that the FPS of the graphics card is below 60, I don't know ... then why do you turn on vertical synchronization?

The working mode of the monitor is very mechanical. It works according to the resolution and refresh rate given by the graphics card. If you can't stand it, you will get a blank screen or report an error. Taking the refresh rate 100MHz as an example, the monitor updates the screen image at 0 second, 0.0 1 second and 0.02 second ... The signal source is the letters output by the graphics card at 0 second, 0.0 1 second and 0.02 second. ...

Number. If the graphics card generates 500 FPS and the display still gives 100 frames per second, then most of the frames generated by the graphics card are wasted; If the graphics card can only generate 20 FPS, the display will still give 100 frames per second, but when the graphics card does not generate a new image, the display will continue to give it according to the previous signal.

Knowing the above, let's discuss the following questions.

Q 2. 1: How does the response time affect me?

A 2. 1: Simply put, the response time brings the trailing or afterimage of the moving image. In this article, we will discuss this in more detail. First of all, we can operate it: right-click "My Computer" on the desktop and select "Properties". The System Properties box appears. Hold down the title bar and drag the whole box quickly. Pay attention to the text in the middle. You will find that the text has a "tail", which is the response time. The longer the response time, the more obvious the tail.

Q 2. 1. 1: Do all kinds of reaction times have the same effect on eyes?

A 2. 1. 1: In fact, our eyes also have reaction time, and images also have residual time on the retina. But in this respect, high-brightness images stimulate human eyes for a longer time and the afterimage is more obvious. When the liquid crystal turns from dark to bright, human eyes have been waiting for it to turn bright, but because the reaction time is one step slower, it is easy for human eyes to feel this phenomenon; However, when the liquid crystal changes from bright to dark, the bright image left on the retina of human eyes lasts a little longer, which is normal for human eyes, and the delay caused by the response time of liquid crystal will be partially or even completely offset by the response time of human eyes. It can be concluded that human eyes are more sensitive to the response time of liquid crystal from dark to bright. (Note that this time is not necessarily called rise time! )

Question 2.2: Is the response time constant?

Answer 2.2: Not so. We usually refer to the typical response time, as mentioned above. When the liquid crystal cell changes between various colors, the process is different, so the response time is different in each case. We can't know the exact time, but it must be long and short. It is not excluded that it takes longer to change from one color to another than from white to black or from black to white. The typical response time is only a reference value under special circumstances, and it can't even be determined to be the maximum value.

Q2.3: What is the response time of CRT?

Answer 2.3:CRT does not need the concept of response time. CRT emits light by bombarding phosphor with electron beams, which basically emits light immediately and will also go out immediately. If the response time must be calculated, some people say it is 1ms, others say it is shorter, but it is meaningless. Our eyes can't feel it anyway.

Question 2.4: The response time of my LCD is 25ms. Does this mean that I can only display 40 frames per second?

A 2.4: We discuss this problem in four parts.

Q 2.4. 1: The response time of my LCD is 25ms. Does this mean that the monitor can only display 40 frames per second?

A 2.4. 1: The number of frames displayed by the monitor per second is uniquely determined by the refresh rate. The refresh rate is 75Hz, and 75 frames are displayed every second, regardless of the response time. If the liquid crystal cell does not complete the reaction to the previous signal and the next signal appears again, the liquid crystal cell will immediately change the next signal.

Q 2.4.2: What is the effect of response time when displaying rapidly changing images?

A 2.4.2: The existence of response time makes the liquid crystal unable to respond to the rapid change of image at the first time, and the liquid crystal box is gradual, unlike the sudden change of phosphor, so the liquid crystal will produce trailing or afterimage instead of intermittent and frame skipping.

Q 2.4.3: The response time of my LCD is 25ms. Does that mean that only 40 frames can be displayed smoothly every second?

A 2.4.3: That's not true. Take a common moving image as an example, between two signals (assuming the refresh rate is 50Hz and the time is 20ms), most liquid crystal cells only need to do relatively similar color transformation, so there will not be too much tailing. Even if the conversion from black to white is needed, it only takes a part of 25 ms. So under normal circumstances, a 25ms LCD can display more than 40 frames smoothly.

Q 2.4.4: The response time of my LCD is 25ms. Does that mean I can display 40 frames smoothly every second?

A 2.4.4: Generally speaking, the response time of 25ms is enough to process 40 frames. You may also see the tail, but it doesn't affect 40 frames, it affects the picture between two frames.

Question 2.5: What factors will affect the response time?

A 2.5: A formula for calculating response time was circulated on the Internet some time ago. The general conclusion is that increasing the voltage can shorten the response time, but it will definitely have negative effects. There is also the viscosity coefficient, which is an inherent characteristic of liquid crystals. In fact, this is what really determines the reaction time. Generally speaking, the response time and color angle of view of LCD produced by the same production line are always contradictory. We can understand the image point in this way (unscientific): when the liquid crystal is viscous, the color is bright and the viewing angle is large, but the response time is slow; When the liquid crystal is thin, the response time will be fast, but the color will be light and the viewing angle will be small. At present, there are many technologies to increase the viewing angle, but the contradiction between color and response time is difficult to reconcile, so we can only rely on the update of product line. Recently, a new generation of panels has been mass-produced in Taiwan Province Province and South Korea, so LCD panels in Taiwan Province and South Korea have produced 12ms or even faster products. The Japanese didn't keep up, so there is no such new product.

Q 2.5. 1: How can manufacturers improve the response time?

A 2.5. 1: Generally, big brands are promoted by changing panels. In the same generation of panels, they are divided into different product lines focusing on color and response time to meet the needs of all kinds of people. No matter which is the key, both are well balanced. Of course, it doesn't rule out that some brands can't update their own panels, and blindly emphasize the response time, which leads to terrible colors and even sequelae. Therefore, when buying an LCD, don't be fastidious about response time, and don't trust small brands.

Q 2.6:25ms？ 16ms？ 8ms？ What kind of response time do I need?

Answer 2.6: What kind of response time you need depends on what you often do. Generally speaking, office, ordinary desktop applications and games without frequent and rapid screen switching have no requirement on response time, which is acceptable within 30ms; FPS and quick-play games have the highest requirements, 16ms can satisfy most players, and really picky players will demand faster. However, racing games, such as NFS, don't require so high response time, and 25ms is enough, because although it is fast, screen switching is basically a gradual process, and in order to make the effect realistic, the fast-moving scenes in the game will be blurred, which will cover up the tail caused by response time. The purpose of choosing LCD is that color always comes first and the response time is acceptable.

Q 2.7: Why is the refresh rate of LCD generally low?

A 2.7: The principle of liquid crystal is different from that of CRT. The phosphor of CRT is instantaneous, and it will go out immediately after being turned on once, so it needs to be turned on frequently. Therefore, the refresh rate should be set above 85Hz, so that the eyes will not feel flashing. Moreover, the liquid crystal is continuously emitting light, and it will remain on until you give it a change signal, so the eyes will never feel flashing. Therefore, the bandwidth refresh rate of liquid crystal does not need to be designed very high.

Q 2.7. 1: What kind of refresh rate is best for human eyes?

A 2.7. 1: Generally speaking, the human eye will think that more than 30 moving images per second are continuous, so the human eye actually only needs a refresh rate of more than 30Hz. Many movies have 24 frames per second. A higher frame rate will make the image more continuous and stable. If it reaches more than 50 frames per second, the human eye will not feel the obvious difference. The default refresh rate of the graphics card is 60Hz, which is enough for moving images (picky FPS players may not be enough). However, due to the instantaneous luminous principle of CRT display, it will still flicker at 60Hz, which is harmful to eyes. So in order to protect your eyes, the higher the refresh rate, the better.

Q 2.7.2: What refresh rate should I set for my LCD?

A 2.7.2: At present, most liquid crystals can be set to 75Hz at the highest. However, some liquid crystals are not in good condition at the highest refresh rate, which will cause some minor problems. The recommended best working state of LCD is 1024.

×768@60Hz and so on. I don't recommend buying this kind of LCD. If you already have it, let it work in the recommended state. If there is no problem, how high can the LCD be set?

Set the refresh rate as high as possible and don't waste it, especially for FPS players. Don't buy an 8ms LCD, let it work at 60Hz.

Q2.8: What are the benefits of vertical synchronization? Will it bring me some losses?

A 2.8: Theoretically, vertical synchronization can make the signal more stable and reduce flicker. But the liquid crystal itself does not flicker, so vertical synchronization can play a more important role in CRT. As for the loss, there should be no, at least the author hasn't found it yet.

Third, pixel articles

(Bad point, point distance, resolution, optimal resolution)

Similarly, before discussing the problem, let's briefly explain a few concepts:

The bad point is a liquid crystal cell, which always displays only one color due to some faults. There are three kinds of bad spots: bright spots (white spots)-always white, dark spots-always black (not bright), and spots-always a certain color. Now color dots are also classified as bright spots, so some manufacturers' promise of "no bright spots" is actually that there are no white dots and color dots.

Distance from point to the center of each liquid crystal cell to the center of adjacent liquid crystal cells. At the highest resolution, the dot pitch of liquid crystal is the distance between adjacent pixels. The dot spacing of standard 15 inch LCD is 0.297mm, 17 inch LCD is 0.264mm, 18 inch LCD is 0.28mm, 19 inch LCD is 0.294mm and 20 inch LCD is 0.255mm..

The best resolution of liquid crystal is the highest resolution. At this resolution, each liquid crystal cell is responsible for displaying one pixel, which is the clearest. The optimal resolution of liquid crystals with different sizes is also different. Standard 15 inch is 1024×768, standard 17 inch-19 inch is 1280× 1024, and standard 20 inch is16024.

Q 3. 1: I bought a bright LCD. Can I return it?

A 3. 1: It depends on the brand and the business. Without bright spots, there is no commitment, and it is generally not easy to return. There is a bright spot that does not belong to the quality problem. Regarding the specific quality standards, netizens can inquire by themselves. Of course, when you buy it, you'd better check it on the spot. The screen is all black.

Q 3.2: Does the dark spot affect the display effect?

A 3.2: The influence of dark spots is far less than that of bright spots, and the light of surrounding units will cover up the dark spots, so it is generally not so conspicuous, and you don't have to pay too much attention to it if you can't see it.

Q 3.3: If it is not lower than the optimal resolution, how can the LCD be displayed?

A 3.3: Under non-optimal resolution (for example, 800×600), the liquid crystal will make the nearby units display some colors according to the position where the pixel should be, and finally cause the desired effect. This step is generally completed by the control circuit and is called interpolation operation. Limited by the point distance and lighting principle, the display under non-optimal resolution will be rough, the picture quality will be good, and the text will be slightly blurred. The specific situation varies with brands and models, and the quality of interpolation operation depends on the quality of control circuit. This leads to a simple method to judge the control circuit-set the resolution low and see how the display effect is.

Q 3.4: Does widescreen mean you can see more content?

A 3.4: It's all caused by advertisements! If widescreen can see more content, then by analogy, 43-inch TV can see more content than 29-inch TV. What can a widescreen bring? The author thinks that there are two advantages: one is that more windows can be opened continuously on the taskbar, and the other is that there are fewer black edges at the top and bottom when watching DVD in full screen, and the screen utilization rate is high. That's all, someone else brought it.

The real trouble is: the image is squashed in full-screen games; Desktop wallpaper is hard to find; When you look at the web page, you will leave a big blank on the left and right sides ... Wide-screen speculation is just a fancy concept, and its practicality is really poor and wide.

The propaganda technique of accusation is really misleading.

Q3.5: 17 inch LCD screen is 5:4. In many cases, the display content is 4:3. Will it deform?

Answer 3.5: It does deform. In fact, the author is also very confused. 640×480, 800×600, 1024×768, 1600× 1200 are all 4:3, but there is an incongruous1280×1020. From the actual feeling, the 4:3 image does have a small vertical elongation on the 17-inch LCD, but it has little effect and will not.

A feeling of obvious distortion.

Q 3.6: Is the dot pitch of liquid crystal as small as possible?

A 3.6: Of course not. Unlike CRT, the dot spacing of LCD is directly reflected in the font size, unless you don't let it work at the best resolution. Therefore, the dot pitch of liquid crystal should not be too large or too small. It is generally believed that each pixel is between 0.25 and 0.30 mm, which is comfortable for human eyes (neither too coarse nor too fine), so the standard dot pitch of liquid crystal is within this range. here

It also varies from person to person. Some people think that 0.297 of 15 inch is rough, while others think that 0.264 of 17 inch is too thin. Generally speaking, older people prefer a larger pitch.

Q 3.6. 1: Is the LCD screen of the ultra-small notebook finer?

A 3.6. 1: A fine is a fine, but it is not a fine. Taking the resolution of 1024×768 as an example, the screens of 14. 1, 13.3, 12. 1 inch are acceptable, but it is difficult to make them smaller. However, no matter how small the screen is, most of them are high-resolution widescreens. The users I have seen using this ultra-small screen are all set to large fonts in windows, which is particularly awkward. Can be said to be ultra-small off-screen viewing.

It sounds beautiful, but the actual display is not cool enough.

Q3.6.2: Is it necessary to upgrade17 inch LCD to 19 inch LCD?

A 3.6.2: As mentioned above, the best resolution of 17 and 19-inch LCD is1280x1024, the difference lies in the point distance, so upgrading from 17 to 19 is purely ". Economically speaking, the cost of 19 inch is much higher than that of 17 inch. Whether it is worth increasing "face" is up to the buyer to weigh.

Fourth, maintenance articles

Liquid crystal is a delicate thing. To keep it in good working condition, we should take good care of it.

Q 4. 1: What kind of working environment does the liquid crystal need?

A 4. 1: Suitable temperature and humidity, no direct sunlight, waterproof and dustproof, basically similar to common electronic products. Let's talk about the temperature here. Generally, liquid crystal can work normally at 0-40 degrees, and the qualified liquid crystal working temperature should at least include this range. The author once saw user feedback in an IT publication. In winter, when the liquid crystal dot is not bright, it will be bright when the air conditioner is turned on.

After reading the instructions, I found that the working temperature is 5-40 degrees. Don't lose money on it when you buy it.

Q 4.2: How to clean the dirty LCD screen?

A 4.2: LCD screen is different from CRT screen and needs to be treated gently. There are two kinds of special cleaners, one is liquid, which is wiped with special cloth dipped in lotion, and the other is "magic cloth", which does not need lotion to wipe directly. I recommend the latter, which is more convenient and safer. Stubborn stains can be washed with breath or dipped in a little water.

If there is really no condition, you can gently wipe it with a soft paper towel. I don't recommend mirror cleaning cloth, because many mirror cleaning cloths will leave fluff on the LCD screen.

Q 4.2. 1: What cleaning methods should be avoided?

A 4.2. 1: Never use a wet cloth or a common rag! If you really have stubborn stains, don't scrape them directly with your nails. You should scrape them clean with a cloth or paper towel, not hard. Do not use alcohol or detergent to clean.

Q 4.2.2: What should be paid attention to in daily maintenance to avoid pollution?

A 4.2.2: Avoid touching the screen by hand; Never enter the water, whether it is the screen or the backplane. If liquid or the like spills on the screen, it should be wiped immediately, otherwise it will be easy to dry, and it will be difficult to wipe it when it is dry.

Q 4.3: Is the screensaver harmful to LCD?

A 4.3: It should be said that the screensaver is harmless to the LCD, but it is not recommended to use the screensaver, because the LCD light is always on when using the screensaver, and its life is limited, so it can be saved.

Q 4.4: After my LCD was turned on for a while, the frame was very hot. Will it be a problem after a long time?

A 4.4: For qualified monitors, heating will not affect their service life or performance, so don't worry too much. It is normal to burn the frame, especially the narrow frame LCD discharge tube has a small space, which naturally makes it easy to feel hot.

Q4.5: Will LCD display the same picture for a long time?

A 4.5: It should be said that generally speaking, "a long time" is no problem, such as a few hours. If it is too long, there may be problems or even permanent bad spots.

Q4.6: What's the difference between LCD black and off?

A 4.6: When closed, the lamp tube does not work and there is no light source; When the display is black, the lamp tube is bright, but all the light is blocked inside the display. In application, it is necessary to avoid letting the liquid crystal work in a large area of black for a long time.

Q 4.7: In order to prolong the lamp life, should the LCD be turned off when not in use?

A 4.7: The lamp has a life, and the lamp switch also has a life, so it is not suitable for frequent switching. Generally speaking, if it takes less than ten minutes, don't turn off your phone.

The above content comes from the internet, please thank the author himself for not making any changes to the article.

References:

Please forgive me, because the article comes from a place where I am not sure! ! !