[vc_row][vc_column][vc_column_text]I have been writing posts about the comparison of all kinds of LCD screens and their structure for a while. Only one kind of LCD screen we are doing I haven’t mentioned yet: VA LCD.
So let me show you something about VA LCD you may not know.
One, VA LCD is the updated version of TN LCD with black background and high contrast. There are 7 main technical parameters for LCD screen. If I have to choose the two most important parameters to indicate the quality of LCD screen, it would be view direction (visual angle) and contrast rate. VA LCD has the best contrast rate.
Please see the picture below. It is an entry-level LCD screen; reflective TN LCD that is gray background and black letters with positive display and doesn’t need a LED backlight.
This kind of LCD panel has been widely used because of its cheap price. You can see the pattern very clear under strong external light, especially sunshine. Actually, the stronger the external light, the better you can see the pattern under normal circumstances. But it has deadly weaknesses that it is not only bad stylish, which means it is not good looking, but also it has a bad view angle and low Contrast Ratio.
Let me put a white LED backlight behind this LCD screen and see what happens.
It is a white background and black letters positive display transmissive TN LCD screen. It looks better, especially at night time, in my opinion.
What if we switch the background color and letter color?
It is a gray background and white letters negative display TN screen with white LED backlight. It isn’t looking so good, is it? Could background color be black instead of gray? It will look much better. Of course, it can, but then it will become VA LCD. People want to improve the view direction (visual angle) and contrast rate of LCD screen, so they invented VA LCD. In other words, VA LCD is the updated version of TN LCD.
It does look good, doesn’t it? It is usually used in high-class electronic products. For example: Vehicle electronic products.
Two, VA LCD has the best contrast ratio. Let us see a group of pictures of VA LCD screen below.
It is no doubt that the black background and white letters VA LCD is the best one. As I know, as long as it is black background and monochrome, it must be VA LCD. That is simple. Only the background color of VA LCD screen is black. In other words, black background LCD screen can’t be made into any other kinds, except VA LCD panel.
Three, it is a negative display and needs LED backlight. Because of its black background, it is certain that VA LCD is a negative display. And is it possible that VA LCD does not use LED backlight? Yes, it is, but it is unreasonable and illogical because VA LCD screen is so expensive, which is only applied in high-class electronic products, and LED backlight is so cheap. In my opinion, it is stupid that it doesn’t use LED backlight.
It is a 12 o’clock view direction VA LCD. You can see it very clear in 12 o’clock, 3 o’clock and 9 o’clock direction. But it is very blurred in 6 o’clock direction. On the other hand, FSTN VCD can be seen very clear in all the directions.
Five, we can get the best display effect when it is applied in the indoor. It will still be good as long as it adopts transflective polarizer film even though outdoor is not the best using condition for VA LCD panel.
Please see the table below.
|Polarizer film||Using condition||LED backlight||stylish||display effect|
|transflective/ expensive||indoor||YES/ expensive||YES||Good|
|transflective/ expensive||outdoor||YES/ expensive||YES||Good|
Six, if you see carefully, you will find out most of VA LCD screens are segment and COB structure. We would only recommend using COG LCD module when it is a very small dot matrix screen. It is a technical challenge to make VA COG dot matrix LCD module, so it is expensive.
Seven, liquid crystal can be divided into three grades: first grade, second grade and third grade according to the temperature. VA LCD is usually in third grade because it is a high-class LCD product.
|Operating Temperature||Storage Temperature|
The price differences for these three grades of temperature are very small, compared with the price differences among TN, HTN, STN, FSTN and VA LCD.
Welcome to email us if you have any interesting ideas or suggestions about LED backlight and LCD screen or anything that relates to it.[/vc_column_text][/vc_column][/vc_row]