The technology of touch screen displays has advanced dramatically in recent years, from the very basic models that were once available only on the expensive high-end computers.
Touch screen displays are becoming cheaper, with the prices dropping every month since they started to become available on more computer models.
So is it worth buying one of these? This article will explain what a touch screen is, why it is useful, and some of the drawbacks.
what is a tn panel?
A Touch Screen is an LCD panel used to input user data, such as in a computer. The screens that employ Twisted Nematic panels are generally cheaper than those that utilize other display technology like IPS, EPS, or SDL, but they also tend to have several disadvantages.
For example, TN panels have low contrast, and their viewing angle is quite limited, mostly in the horizontal direction. When a picture is displayed on one of these screens, it looks blurry at the edges. Even when you are sitting very close to the screen, you still cannot see the fine details when you are working at a distance.
It means that even when very close to the screen, text and images look blurry at the edges. There are also issues with image display latency and color shifting.
However, what can overcome these problems using motion detection schemes, which allow the pixels to shift when the image changes. Another common problem in most TN monitors is screen burning, where one monitor in a group is always redrawn at the top of the screen when another is flickered.
Although some manufacturers have solved this problem by introducing a new low power mode, this is not a severe problem. To solve these problems, a higher refresh rate has been introduced.
TN Panel Response Time
The average pixel response time for a TFT LCD panel is about 7 milliseconds, which is very fast. Compared to other typical LCD panels, the rate is excellent. Also, TFT LCDs have a very high contrast ratio, which means that images appear sharp and crisp. Generally, LED backlighting systems in modern devices are not used for LCD displays because they consume more power.
When a TFT panel is selected, the display is based on pixel response times and not on power consumption. The pixel response times and the contrast ratio of a LED panel make the two types of panels somewhat similar.
Another advantage of an organic LED LCD screen is that they have high-speed refresh rates, helping consumers save energy.
The latest VA panels with nearly constant refresh rates of 60 Hz have been developed and are often found in high-resolution LCD monitors.
The major disadvantage of using VA panels is their cost, which is double that a standard LCD panel. However, they are also available in thin models, and consumers can choose one according to their individual needs.
They also offer wide viewing angles and can be used in HDTV format as well.
Perhaps the best known of all flat-panel monitors is the AMOLED display, commonly referred to as Liquid Crystal Displays or LCD. They use a semi-translucent membrane to provide color reproduction.
In general, AMOLED panels‘ response times are slower than those for standard LCDs, but the improved color reproduction makes them much more preferable. Also, they are capable of too high contrast ratios and use few pixels for each color, which results in crisper images.
Pixel Shifting Panels
Finally, there are the in-plane switching and pixel shifting panels. An in-plane switching panel uses liquid crystals to provide fluid crystal motion on the screen. These liquid crystals are arranged in a grid, which allows the liquid crystal to change its position on the screen at different places, which will enable the image to be seen.
This panel has the slowest response time and lowers the contrast ratio among all the flat-panel types, but some users find them much more explicit than other types. Their picture quality is not as good as those of the different two types, however.
The most popular of all flat panels is the VA (verage, flat, anti-glare) variety. Flat-screen VA panels have an excellent contrast ratio, high brightness, and perfect color reproduction.
They are most often used for video games and movie displays and are available in various sizes and display formats. These are the most widely used panels in North America, Europe, and Asia and the cheapest of all the types of screens available. They also offer the fastest response times and the highest level of resolution.