tft display vs tn in stock
IPS (In-Plane Switching) lcd is still a type of TFT LCD, IPS TFT is also called SFT LCD (supper fine tft ),different to regular tft in TN (Twisted Nematic) mode, theIPS LCD liquid crystal elements inside the tft lcd cell, they are arrayed in plane inside the lcd cell when power off, so the light can not transmit it via theIPS lcdwhen power off, When power on, the liquid crystal elements inside the IPS tft would switch in a small angle, then the light would go through the IPS lcd display, then the display on since light go through the IPS display, the switching angle is related to the input power, the switch angle is related to the input power value of IPS LCD, the more switch angle, the more light would transmit the IPS LCD, we call it negative display mode.
The regular tft lcd, it is a-si TN (Twisted Nematic) tft lcd, its liquid crystal elements are arrayed in vertical type, the light could transmit the regularTFT LCDwhen power off. When power on, the liquid crystal twist in some angle, then it block the light transmit the tft lcd, then make the display elements display on by this way, the liquid crystal twist angle is also related to the input power, the more twist angle, the more light would be blocked by the tft lcd, it is tft lcd working mode.
A TFT lcd display is vivid and colorful than a common monochrome lcd display. TFT refreshes more quickly response than a monochrome LCD display and shows motion more smoothly. TFT displays use more electricity in driving than monochrome LCD screens, so they not only cost more in the first place, but they are also more expensive to drive tft lcd screen.The two most common types of TFT LCDs are IPS and TN displays.
TN panels generally are good enough for most people especially if they do not want to spend a lot of money. Their colors are not as accurate as PVA / MVA / IPS panels, but for most people it"s a non factor unless what you do with your monitor absolutely requires accurate colors. Due to the nature of how TN panels work however, they are more prone to display video artifiact than other panel techs.
For example, in Batman: The Dark Knight DVD movie there is a scene where the Joker blows up a hospital and there"s lots of thick black smoke. On my Asus VK246H TN panel monitor the smoke is pixelated (blocky) and the Joker"s bare arms and leg also gets pixelated in that scene. I do not see those artifacts when viewing my the movie on my NEC LCD2690WUXi or Planar PX2611w monitors with H-IPS panels.
Go to a store and look at monitors there. 99% of then will be using TN panels. If you don"t like how any of them look, then it"s time consider the other more expensive types of LCD monitors.
If you want to buy a new monitor, you might wonder what kind of display technologies I should choose. In today’s market, there are two main types of computer monitors: TFT LCD monitors & IPS monitors.
The word TFT means Thin Film Transistor. It is the technology that is used in LCD displays. We have additional resources if you would like to learn more about what is a TFT Display. This type of LCDs is also categorically referred to as an active-matrix LCD.
These LCDs can hold back some pixels while using other pixels so the LCD screen will be using a very minimum amount of energy to function (to modify the liquid crystal molecules between two electrodes). TFT LCDs have capacitors and transistors. These two elements play a key part in ensuring that the TFT display monitor functions by using a very small amount of energy while still generating vibrant, consistent images.
Industry nomenclature: TFT LCD panels or TFT screens can also be referred to as TN (Twisted Nematic) Type TFT displays or TN panels, or TN screen technology.
IPS (in-plane-switching) technology is like an improvement on the traditional TFT LCD display module in the sense that it has the same basic structure, but has more enhanced features and more widespread usability.
Both TFT display and IPS display are active-matrix displays, neither can’t emit light on their own like OLED displays and have to be used with a back-light of white bright light to generate the picture. Newer panels utilize LED backlight (light-emitting diodes) to generate their light hence utilizing less power and requiring less depth by design. Neither TFT display nor IPS display can produce color, there is a layer of RGB (red, green, blue) color filter in each LCD pixels to produce the color consumers see. If you use a magnifier to inspect your monitor, you will see RGB color in each pixel. With an on/off switch and different level of brightness RGB, we can get many colors.
Winner. IPS TFT screens have around 0.3 milliseconds response time while TN TFT screens responds around 10 milliseconds which makes the latter unsuitable for gaming
Winner. the images that IPS displays create are much more pristine and original than that of the TFT screen. IPS displays do this by making the pixels function in a parallel way. Because of such placing, the pixels can reflect light in a better way, and because of that, you get a better image within the display.
As the display screen made with IPS technology is mostly wide-set, it ensures that the aspect ratio of the screen would be wider. This ensures better visibility and a more realistic viewing experience with a stable effect.
Winner. While the TFT LCD has around 15% more power consumption vs IPS LCD, IPS has a lower transmittance which forces IPS displays to consume more power via backlights. TFT LCD helps battery life.
Normally, high-end products, such as Apple Mac computer monitors and Samsung mobile phones, generally use IPS panels. Some high-end TV and mobile phones even use AMOLED (Active Matrix Organic Light Emitting Diodes) displays. This cutting edge technology provides even better color reproduction, clear image quality, better color gamut, less power consumption when compared to LCD technology.
This kind of touch technology was first introduced by Steve Jobs in the first-generation iPhone. Of course, a TFT LCD display can always meet the basic needs at the most efficient price. An IPS display can make your monitor standing out.
The word TFT means Thin Film Transistor. It is the technology that is used in LCD or Liquid Crystal Display. It is also called Active Matrix LCD which differentializes from Passive Matrix LCD. A TFT substrate is composed of a matrix of pixels and ITO electrode (Indium Tin Oxide, a transparent electric conducting film) each with a TFT device and is so called array. Thousands or millions of these pixels together create an image on the display. The diagram below shows the simple structure of a pixel.
As long as there are TFT in the LCD, the LCD should be called a TFT LCD. But when the TFT LCD display was first commercialized, 100% TFT LCDs were TN (twisted Nematic) type TFT displays. As TN is a very technical term so most of the users ignored TN and named TN type TFT display as TFT display. While the newly developed TFT LCD display technologies such as IPS (in-plane-switching ) type TFT display, O-Film type TFT display (derived from TN type TFT display), MVA( Multi-domain Vertical Alignment) type TFT display, AFFS (Advanced Fringe Field Switching) type TFT display, they are widely call IPS display, O-Film display, MVA display and AFFS display. As the above terms have been used for long and widely accepted in the market, we will not try to correct the misunderstanding here. We will still use the TFT display (should be TN type TFT display) and IPS display (should be IPS type TFT display) in the following.
The twisted nematic effect (TN-LCD) was a main technology breakthrough that made LCDs practical. TN LCDs first make battery powered devices popular. TN-LCD displays led to the rapid expansion in the display field, quickly replacing other displays like LEDs, plasma, CRTs etc. By the 1990s, TN LCDs were widely used in portable electronics.
The TN display takes advantage of the ability of the nematic substance to rotate the polarization of light beams passing through it. Two polarizing filters, parallel planes of glass with their polarizing lines oriented at right angles with respect to each other, are positioned on either side of the liquid crystal. When light enters the display, it is polarized by the input filter. In the absence of an electric field, all the incoming light is transmitted. This is because the light polarization is rotated 90 degrees by the nematic liquid crystal, and the light therefore passes easily through the output filter, which is oriented to match the 90-degree shift. With the application of a voltage, an electric field is produced in the nematic liquid crystal. Under these conditions the polarization effect is reduced. If the voltage is large enough, the polarization effect disappears altogether, and the light is blocked by the output polarizing filter. The diagram below shows how a TN LCD works.
The best feature of TFT displays is the low cost due to a simpler manufacturing process, low-cost raw materials, and one of the oldest technologies for LCD displays. But they are not the best quality considering poor viewing angles, lower contrast ratio, slower response time, lower aperture ratio (each pixel not bright enough), and the worst is that there is one view angle with gray scale inversion (reversed image), see the below picture for reference.
IPS (in-plane-switching) technology is also one type of TFT LCD display. The basic LCD structure is similar to TN type TFT display but the inside display schematic is different.
In 1992, Hitachi researchers in Japan first developed details of the IPS technology. NEC and Hitachi became early manufacturers of active-matrix addressed LCDs based on the IPS technology. In 1996, Samsung developed the optical patterning technique that enables multi-domain LCD. Multi-domain and in-plane switching subsequently remained the dominant LCD designs through 2006. IPS technology is widely used in LCD panels for TVs, laptops, monitors, and smartphones. Apple Inc. products branded with the label Retina Display (such as iPhone 4 onward, iPad 3 on, iPad Mini 2 on, MacBook Pro with Retina display adopted IPS LCDs with LED backlighting.
An IPS LCD panel, when no electric field is applied to the liquid crystal cells, the cells naturally align in liquid crystal cells in a horizontal direction between two glass substrates which blocks the transmission of light from the backlight. This makes the display dark and results in a black display screen. When an electric field is applied, the liquid crystal cells are able to rotate through 90° allowing light to pass through resulting in a white display screen. IPS panels have superior image quality, good contrast ratio and wide viewing angles of up to 170°. IPS panels are well suited for graphics design and other applications which require accurate and consistent color reproduction.
In summary, normally high-end products such as Apple Mac computer monitors and Samsung mobile phones generally use IPS panels. Some high-end TV and mobile phones even use AMOLED (Active Matrix Organic Light Emitting Diodes) displays. This cutting-edge technology provides even better color reproduction, clear image quality, better color gamut, less power consumption when compared to LCD technology. Of course, a TFT LCD display can always meet the basic needs at the most efficient price.
This article is an original piece of content written by Bill Cheung, a marketing manager who has an engineering and technical support background at Orient Display. We are a LCD and display technology provider with over two decades of industry experience in delivering cutting edge display solutions. Please browse our knowledge base if you would like to learn more about LCDs!
1.TN-type liquid crystal display due to low technical level, low price, application range of small-size products under 3 inches and can only show black and white monochrome and do some simple text, digital display, mainly used in electronic watches, calculators, simple handheld game consoles and other consumer electronics.
2.STN-type liquid crystal display is simpler than TFT-type process, high yield, relatively cheap, for the contrast between strong and screen conversion reaction time faster commodities, so more applied to information processing equipment. If you add a color filter in front of the LCD panel, you can display a variety of colors, even up to the degree of full color. These products are mostly used in the display of text, digital and graphics functions, such as low-grade laptops, handheld computers, stock machines and personal digital assistants (PDAs) and other portable products.
3. TFT LCD display because the display reaction speed is faster, suitable for animation and video display, so it is widely used in digital cameras, LCD projectors, laptops, desktop LCD monitors. Because it is better than STN-type products in terms of color quality and reaction speed, it is also the mainstream product on the market.
The LCD follows a series of rules that are different from CRT displays. THE LCD overcomes the shortcomings of CRT"s large size, power consumption and flickering, but also brings problems such as high cost, low viewing angle and unsatisfactory color display. CrT displays can be selected in a range of resolutions and can be adjusted to screen requirements, but LCD screens contain only a fixed number of LCD units and can only be displayed at one resolution (one pixel per unit) on the full screen. The CRT usually has three electronic guns, and the electron stream that is fired must be precisely aggregated or it will not be clearly displayed. However, there is no focus problem with the LCD because each LCD unit is switched on and off separately. That"s why the same picture is so clear on the LCD screen. LCD also does not have to worry about refresh frequency and flickering, the LCD unit is either on or off, so the image displayed at a low refresh frequency of 40-60Hz will not flash more than the image displayed at 75Hz. On the other hand, lcd units of LCD screens are prone to defects. For the 1024x768 screen, each pixel consists of three units, responsible for the red, green, and blue display of one unit so a total of about 2.4 million units (1024x768x3 x 2359296). It is difficult to guarantee that all these units are intact. Most likely, some of them have been shorted (with "bright spots") or broken (with "black spots"). Lcd displays contain things that are not used in CRT technology. The light source for the screen is the fluorescent tube that wraps behind it. Sometimes we find unusually bright lines in one part of the screen. There may also be some indecent stripes, a special light color
Again, IPS is the clear winner here. The vertical viewing angles are very similar to the horizontal ones on both IPS and VA panels. Unfortunately, this is one area where TN panels are usually much, much worse. TN monitors degrade rapidly from below, and colors actually inverse - resulting in a negative image that can be distracting. For this reason, if you decide to buy a TN monitor, look for one with an excellent height adjustment, or consider buying a VESA mounting arm, as you should mount TN monitors at eye level. Even when mounted properly, larger TN displays can appear non-uniform at the edges.
There"s usually not much difference between VA and IPS panels in terms of gray uniformity. It"s rare for monitors to have uniformity issues, and even on monitors that perform worse than average, it"s usually not noticeable with regular content. TN monitors tend to perform a bit worse than usual, though, and the top half of the screen is almost always darker than the rest, but that"s an artifact of the bad vertical viewing angles.
Black uniformity tends to vary significantly, even between individual units of the same model, and there"s no single panel type that performs the best. It"s rare for monitors to have good black uniformity, and almost every monitor we"ve tested has some noticeable cloudiness or backlight bleed. IPS and TN panels can look slightly worse due to their low contrast ratios, as the screen can take on more of a bluish tint when displaying dark scenes. Like with contrast, black uniformity issues usually aren"t very noticeable unless you"re looking at dark content and you"re in a dark room. If you only use your monitor in a bright environment, generally speaking, you don"t need to worry about black uniformity.
Historically, TN panels used to have the worst colors, as many of them were cheaper models that only supported 6-bit colors or used techniques like dithering (FRC) to approximate 8-bit colors. Most displays today, including TN models, are at least 8 bit, and many of them are even able to approximate 10-bit colors through dithering. New technologies, like LG"s Nano IPS and Samsung"s Quantum Dot, add an extra layer to the LCD stack and have significantly improved the color gamut of modern IPS and VA displays, leaving TN a bit behind. Between them, NANO IPS is slightly better, as it tends to offer better coverage of the Adobe RGB color space. Although the difference is minor, IPS panels still have a slight edge over VA and TN displays.
Although TN panels have caught up a bit in the SDR color space, they"re far behind when it comes to HDR, so if you"re looking for a good HDR color gamut, avoid TN panels. Between VA and IPS panels, the difference isn"t as significant; however, IPS panels still have a slight edge. The best VA panels top out at around 90% coverage of the DCI P3 color space used by most current HDR content. IPS panels go as high as 98% coverage of DCI P3, rivaling even some of the best TVs on the market. Due to the very high coverage of DCI P3 on both VA and IPS, the difference isn"t that noticeable, though, as most content won"t use the entire color space anyway.
Although not necessarily as noticeable to everyone as the differences in picture quality, there can also be a difference in motion handling between IPS, VA, and TN displays. TN panels historically offered the best gaming performance, as they had the highest refresh rates and extremely fast response times. Manufacturers have found ways to drastically improve the motion handling of VA and IPS panels, though, and the difference isn"t as pronounced.
LCD panel technology has changed drastically over the last few years, and the historical expectations for response time performance don"t necessarily hold anymore. For years, TN monitors had the fastest response times by far, but that"s started to change. New high refresh-rate IPS monitors can be just as fast.
VA panels are a bit of a strange situation. They typically have slightly slower response times overall compared to similar TN or IPS models. It"s especially noticeable in near-black scenes, where they tend to be significantly slower, resulting in dark trails behind fast-moving objects in dark scenes, commonly known as black smear. Some recent VA panels, such as the Samsung Odyssey G7 LC32G75T, get around it by overdriving the pixels. It results in much better dark scene performance but a more noticeable overshoot in brighter areas.
There"s another display technology that"s growing in popularity: OLED. OLED, or organic light-emitting diode, is very different from the conventional LCD technology we"ve explored above. OLED panels are electro-emissive, which means each pixel emits its own light when it receives an electric signal, eliminating the need for a backlight. Since OLED panels can turn off individual pixels, they have deep, inky blacks with no blooming around bright objects. They also have excellent wide viewing angles, a near-instantaneous response time, and excellent gray uniformity.
As you can probably tell by now, no one panel type works best for everyone; it all depends on your exact usage. Although there used to be some significant differences between panel types, as technology has improved, these differences aren"t as noticeable. The two exceptions to this are viewing angles and contrast. If you"re in a dark room, a VA panel that can display deep blacks is probably the best choice. If you"re not in a dark room, you should focus on the other features of the monitor and choose based on the features that appeal to your exact usage. IPS panels are generally preferred for office use, and TN typically offers the best gaming experience, but recent advancements in VA and IPS technology are starting to change those generalizations. For the most part, the differences between each panel type are so minor now that it doesn"t need to be directly factored into your buying decision.
TN is by far the worst, almost all cheap panels are TN. The problem is the viewing angles, as you angle the monitor to your vision the brightness will shift and the colours will change, leaving you with a pretty terrible image.
Best place to see this is in comparison shots, I like to use Digital Versus for this, for example this is the default TN monitor which is shown when you load the page, with the right hand monitor switched to a good S-IPS monitor which I"m currently running.
You can see not only does the TN panel have washed out colours but the viewing angles are terrible especially the vertical ones. With an ultra wide display the far edges are at really shallow angles to you and so would look pretty terrible.
As you might already be aware, there’s a large variety of versatile digital display types on the market, all of which are specifically designed to perform certain functions and are suitable for numerous commercial, industrial, and personal uses. The type of digital display you choose for your company or organization depends largely on the requirements of your industry, customer-base, employees, and business practices. Unfortunately, if you happen to be technologically challenged and don’t know much about digital displays and monitors, it can be difficult to determine which features and functions would work best within your professional environment. If you have trouble deciphering the pros and cons of using TFT vs. IPS displays, here’s a little guide to help make your decision easier.
TFT stands for thin-film-transistor, which is a variant of liquid crystal display (LCD). TFTs are categorized as active matrix LCDs, which means that they can simultaneously retain certain pixels on a screen while also addressing other pixels using minimal amounts of energy. This is because TFTs consist of transistors and capacitors that respectively work to conserve as much energy as possible while still remaining in operation and rendering optimal results. TFT display technologies offer the following features, some of which are engineered to enhance overall user experience.
The bright LED backlights that are featured in TFT displays are most often used for mobile screens. These backlights offer a great deal of adaptability and can be adjusted according to the visual preferences of the user. In some cases, certain mobile devices can be set up to automatically adjust the brightness level of the screen depending on the natural or artificial lighting in any given location. This is a very handy feature for people who have difficulty learning how to adjust the settings on a device or monitor and makes for easier sunlight readability.
One of the major drawbacks of using a TFT LCD instead of an IPS is that the former doesn’t offer the same level of visibility as the latter. To get the full effect of the graphics on a TFT screen, you have to be seated right in front of the screen at all times. If you’re just using the monitor for regular web browsing, for office work, to read and answer emails, or for other everyday uses, then a TFT display will suit your needs just fine. But, if you’re using it to conduct business that requires the highest level of colour and graphic accuracy, such as completing military or naval tasks, then your best bet is to opt for an IPS screen instead.
Nonetheless, most TFT displays are still fully capable of delivering reasonably sharp images that are ideal for everyday purposes and they also have relatively short response times from your keyboard or mouse to your screen. This is because the pixel aspect ration is much narrower than its IPS counterpart and therefore, the colours aren’t as widely spread out and are formatted to fit onto the screen. Primary colours—red, yellow, and blue—are used as the basis for creating brightness and different shades, which is why there’s such a strong contrast between different aspects of every image. Computer monitors, modern-day HD TV screens, laptop monitors, mobile devices, and even tablets all utilize this technology.
IPS (in-plane-switching) technology is almost like an improvement on the traditional TFT display module in the sense that it has the same basic structure, but with slightly more enhanced features and more widespread usability. IPS LCD monitors consist of the following high-end features.
IPS screens have the capability to recognize movements and commands much faster than the traditional TFT LCD displays and as a result, their response times are infinitely faster. Of course, the human eye doesn’t notice the difference on separate occasions, but when witnessing side-by-side demonstrations, the difference is clear.
Wide-set screen configurations allow for much wider and versatile viewing angles as well. This is probably one of the most notable and bankable differences between TFT and IPS displays. With IPS displays, you can view the same image from a large variety of different angles without causing grayscale, blurriness, halo effects, or obstructing your user experience in any way. This makes IPS the perfect display option for people who rely on true-to-form and sharp colour and image contrasts in their work or daily lives.
IPS displays are designed to have higher transmittance frequencies than their TFT counterparts within a shorter period of time (precisely 1 millisecond vs. 25 milliseconds). This speed increase might seem minute or indecipherable to the naked eye, but it actually makes a huge difference in side-by-side demonstrations and observations, especially if your work depends largely on high-speed information sharing with minimal or no lagging.
Just like TFT displays, IPS displays also use primary colours to produce different shades through their pixels. The main difference in this regard is the placement of the pixels and how they interact with electrodes. In TFT displays, the pixels run perpendicular to one another when they’re activated by electrodes, which creates a pretty sharp image, but not quite as pristine or crisp as what IPS displays can achieve. IPS display technologies employ a different configuration in the sense that pixels are placed parallel to one another to reflect more light and result in a sharper, clearer, brighter, and more vibrant image. The wide-set screen also establishes a wider aspect ratio, which strengthens visibility and creates a more realistic and lasting effect.
When it comes to deciphering the differences between TFT vs. IPS display technologies and deciding which option is best for you and your business, the experts at Nauticomp Inc. can help. Not only do we offer a wide variety of computer displays, monitors, and screen types, but we also have the many years of experience in the technology industry to back up our recommendations and our knowledge. Our top-of-the-line displays and monitors are customized to suit the professional and personal needs of our clients who work across a vast array of industries. For more information on our high-end displays and monitors, please contact us.
Let us start with the basics first; refresh the knowledge about TN and LCD displays in general, later we will talk about TFTs (Thin Film Transistors), how they differ from regular monochrome LCD displays. Then we will go on to the ghosting effect, so we will not only discuss the technology behind the construction of the TFT, but also some phenomena, like the ghosting effect, or grayscale inversion, that are important to understand when using an LCD TFT display.
Next, we will look at different technologies of the TFT LCD displays like TN, IPS, VA, and of course about transmissive and transflective LCD displays, because TFT displays also can be transmissive and transflective. In the last part we will talk about backlight.
Let us start with a short review of the most basic liquid crystal cell, which is the TN (twisted nematic) display. On the picture above, we can see that the light can be transmit through the cell or blocked by the liquid crystal cell using voltage. If you want to learn more about monochrome LCD displays and the basics of LCD displays, follow this link.
What is a TFT LCD display and how it is different from a monochrome LCD display? TFT is called an active display. Active, means we have one or more transistors in every cell, in every pixel and in every subpixel. TFT stands for Thin Film Transistor, transistors that are very small and very thin and are built into the pixel, so they are not somewhere outside in a controller, but they are in the pixel itself. For example, in a 55-inch TV set, the TFT display contains millions of transistors in the pixels. We do not see them, because they are very small and hidden, if we zoom in, however, we can see them in every corner of each pixel, like on the picture below.
On the picture above we can see subpixels, that are basic RGB (Red, Green, Blue) colors and a black part, with the transistors and electronic circuits. We just need to know that we have pixels, and subpixels, and each subpixel has transistors. This makes the display active, and thus is called the TFT display. TFT displays are usually color displays, but there are also monochrome TFT displays, that are active, and have transistors, but have no colors. The colors in the TFT LCD display are typically added by color filters on each subpixel. Usually the filters are RGB, but we also have RGBW (Red, Green, Blue, White) LCD displays with added subpixels without the filter (White) to make the display brighter.
Going a little bit deeper, into the TFT cell, there is a part inside well known to us from the monochrome LCD display Riverdi University lecture. We have a cell, liquid crystal, polarizers, an ITO (Indium Tin Oxide) layer for the electrodes, and additionally an electronic circuit. Usually, the electronic circuit consists of one transistor and some capacitors to sustain the pixel state when we switch the pixel OFF and ON. In a TFT LCD display the pixels are much more complicated because apart from building the liquid crystal part, we also need to build an electronic part.
That is why TFT LCD display technologies are very expensive to manufacture. If you are familiar with electronics, you know that the transistor is a kind of switch, and it allows us to switch the pixel ON and OFF. Because it is built into the pixel itself, it can be done very quickly and be very well controlled. We can control the exact state of every pixel not only the ON and OFF states, but also all the states in between. We can switch the light of the cells ON and OFF in several steps. Usually for TFT LCD displays it will be 8-bit steps per color, so we have 256 steps of brightness for every color, and every subpixel. Because we have three subpixels, we have a 24-bit color range, that means over 16 million combinations, we can, at least theoretically, show on our TFT LCD display over 16 million distinct colors using RGB pixels.
Now that we know how the TFT LCD display works, we can now learn some practical things one of which is LCD TFT ghosting. We know how the image is created, but what happens when we have the image on the screen for a prolonged time, and how to prevent it. In LCD displays we have something called LCD ghosting. We do not see it very often, but in some displays this phenomenon still exists.
If some elements of the picture i.e., your company logo is in the same place of the screen for a long period of time, for couple of weeks, months or a year, the crystals will memorize the state and later, when we change the image, we may see some ghosting of those elements. It really depends on many conditions like temperature and even the screen image that we display on the screen for longer periods of time. When you build your application, you can use some techniques to avoid it, like very rapid contrast change and of course to avoid the positioning the same image in the same position for a longer time.
You may have seen this phenomenon already as it is common in every display technology, and even companies like Apple put information on their websites, that users may encounter this phenomenon and how to fix it. It is called image ghosting or image persistence, and even Retina displays are not free of it.
Another issue present in TFT displays, especially TN LCD displays, is grayscale inversion. This is a phenomenon that changes the colors of the screen according to the viewing angle, and it is only one-sided. When buying a TFT LCD display, first we need to check what kind of technology it is. If it is an IPS display, like the Riverdi IPS display line, then we do not need to worry about the grayscale inversion because all the viewing angles will be the same and all of them will be very high, like 80, 85, or 89 degrees. But if you buy a more common or older display technology type, like the TN (twisted nematic) display, you need to think where it will be used, because one viewing angle will be out. It may be sometimes confusing, and you need to be careful as most factories define viewing direction of the screen and mistake this with the greyscale inversion side.
On the picture above, you can see further explanation of the grayscale inversion from Wikipedia. It says that some early panels and also nowadays TN displays, have grayscale inversion not necessary up-down, but it can be any angle, you need to check in the datasheet. The reason technologies like IPS (In-Plane Switching), used in the latest Riverdi displays, or VA, were developed, was to avoid this phenomenon. Also, we do not want to brag, but the Wikipedia definition references our website.
We know already that TN (twisted nematic) displays, suffer from grayscale inversion, which means the display has one viewing side, where the image color suddenly changes. It is tricky, and you need to be careful. On the picture above there is a part of the LCD TFT specification of a TN (twisted nematic) display, that has grayscale inversion, and if we go to this table, we can see the viewing angles. They are defined at 70, 70, 60 and 70 degrees, that is the maximum viewing angle, at which the user can see the image. Normally we may think that 70 degrees is better, so we will choose left and right side to be 70 degrees, and then up and down, and if we do not know the grayscale inversion phenomena, we may put our user on the bottom side which is also 70 degrees. The viewing direction will be then like a 6 o’clock direction, so we call it a 6 o’clock display. But you need to be careful! Looking at the specification, we can see that this display was defined as a 12 o’clock display, so it is best for it to be seen from a 12 o’clock direction. But we can find that the 12 o’clock has a lower viewing angle – 60 degrees. What does it mean? It means that on this side there will be no grayscale inversion. If we go to 40, 50, 60 degrees and even a little bit more, probably we will still see the image properly. Maybe with lower contrast, but the colors will not change. If we go from the bottom, from a 6 o’clock direction where we have the grayscale inversion, after 70 degrees or lower we will see a sudden color change, and of course this is something we want to avoid.
To summarize, when you buy older technology like TN and displays, which are still very popular, and Riverdi is selling them as well, you need to be careful where you put your display. If it is a handheld device, you will see the display from the bottom, but if you put it on a wall, you will see the display from the top, so you need to define it during the design phase, because later it is usually impossible or expensive to change the direction.
We will talk now about the other TFT technologies, that allow us to have wider viewing angles and more vivid colors. The most basic technology for monochrome and TFT LCD displays is twisted nematic (TN). As we already know, this kind of displays have a problem with grayscale inversion. On one side we have a higher retardation and will not get a clear image. That is why we have other technologies like VA (Vertical Alignment), where the liquid crystal is differently organized, and another variation of the TFT technology – IPS which is In-Plane Switching. The VA and IPS LCD displays do not have a problem with the viewing angles, you can see a clear image from all sides.
Nowadays all TV sets, tablets and of course mobile phones are IPS or VA. You can turn them around and see the image clear from all sides. But, for monitor applications the TN technology is still widely used, because the monitor usually is in front of you and most of the time you look directly at it, from top, left or right side, but very rarely from the bottom, so the grayscale inversion viewing angle can be placed there. This technology still is very practical because it is affordable and has some advantages for gamers because it is very fast.
Apart from the different organization of the liquid crystals, we also organize subpixels a little bit differently in a VA and IPS LCD displays. When we look closer at the TN display, we will just see the subpixels with color filters. If we look at the VA or IPS display they will have subpixels of subpixels. The subpixels are divided into smaller parts. In this way we can achieve even wider viewing angles and better colors for the user, but of course, it is more complicated and more expensive to do.
The picture above presents the TN display and grayscale inversion. For IPS or VA technology there is no such effect. The picture will be the same from all the sides we look so these technologies are popular where we need wide viewing angles, and TN is popular where we don’t need that, like in monitors. Other advantages of IPS LCD displays are they give accurate colors, and wide viewing angles. What is also important in practice, in our projects, is that the IPS LCD displays are less susceptible to mechanical force. When we apply mechanical force to the screen, and have an optically bonded touch screen, we push the display as well as squeeze the cells. When we have a TN display, every push on the cell changes the image suddenly, with the IPS LCD displays with in-plane switching, different liquid crystals organization, this effect is lesser. It is not completely removed but it is much less distinct. That is another reason IPS displays are very popular for smartphones, tablets, when we have the touchscreens usually optically bonded.
If we wanted to talk about disadvantages, there is a question mark over it, as some of them may be true, some of them do not rely on real cases, what kind of display, what kind of technology is it. Sometimes the IPS displays can have higher power consumption than others, in many cases however, not. They can be more expensive, but not necessarily. The new IPS panels can cost like TN panels, but IPS panels definitely have a longer response time. Again, it is not a rule, you can make IPS panels that are very fast, faster than TN panels, but if you want the fastest possible display, probably the TN panel will be the fastest. That is why the TN technology is still popular on the gaming market. Of course, you can find a lot of discussions on the internet, which technology is better, but it really depends on what you want to achieve.
Now, let us look at the backlight types. As we see here, on the picture above, we have four distinct types of backlight possible. The most common, 95 or 99 per cent of the TFT LCD displays on the market are the transmissive LCD display type, where we need the backlight from the back. If you remember from our Monochrome LCD Displays lecture, for transmissive LCD displays you need the backlight to be always on. If you switch the backlight off, you will not see anything. The same as for monochrome LCD displays, but less popular for TFT displays, we have the transflective LCD display type. They are not popular because usually for transflective TFT displays, the colors lack in brightness, and the displays are not very practical to use. You can see the screen, but the application is limited. Some transflective LCD displays are used by military, in applications where power consumption is paramount; where you can switch the backlight off and you agree to have lower image quality but still see the image. Power consumption and saving energy is most important in some kind of applications and you can use transflective LCD displays there. The reflective type of LCD displays are almost never used in TFT. There is one technology called Low Power Reflective Displays (LPRD) that is used in TFT but it is not popular. Lastly, we have a variation of reflective displays with frontlight, where we add frontlight to the reflective display and have the image even without external light.
Just a few words about Low Power Reflective Displays (LPRD). This kind of display uses environmental light, ambient light to reflect, and produce some colors. The colors are not perfect, not perfectly clear, but this technology is becoming increasingly popular because it allows to have color displays in battery powered applications. For example, a smartwatch would be a case for that technology, or an electrical bike or scooter, where we can not only have a standard monochrome LCD display but also a TFT LCD color display without the backlight; we can see the image even in
strong sunlight and not need backlight at all. So, this kind of TFL LCD display technology is getting more and more popular when we have outdoor LCD displays and need a low power consumption.
On the picture above, we have some examples of how transmissive and reflective LCD displays work in the sunlight. If we have a simple image, like a black and white pattern, then on a transmissive LCD display, even with 1000 candela brightness, the image probably will be lower quality than for a reflective LCD display; if we have sunlight, we have very strong light reflections on the surface of the screen. We have talked about contrast in more detail in the lecture Sunlight Readable Displays. So, reflective LCD displays are a better solution for outdoor applications than transmissive LCD displays, where you need a really strong backlight, 1000 candela or more, to be really seen outdoors.
To show you how the backlight of LCD displays is built, we took the picture above. You can see the edge backlight there, where we have LEDs here on the small PCB on the edge, and we have a diffuser that distributes the light to the whole surface of LCD screen.
In addition to the backlight, we have something that is called a frontlight. It is similar to backlight, it also uses the LEDs to put the light into it, but the frontlight needs to be transparent as we have the display behind. On the example on the picture above we can see an e-paper display. The e-paper display is also a TFT display variation, but it is not LCD (liquid crystal), it is a different technology, but the back of the display is the same and it is reflective. The example you see is the Kindle 4 eBook reader. It uses an e-paper display and a frontlight as well, so you can read eBooks even during the night.
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When deciding between FSTN vs TN LCDs, the decision comes down to lower cost vs sharper contrast and wider viewing angle. This is the choice to make when ordering a Liquid Crystal Display from FocusLCDs.com.
Note: LCDs are not the same as TFTs or OLEDs. LCDs have one color background and a different color character/segment. There are many advantages of LCDs over other display technologies, but I will not cover that in this article since I want to keep it short and I am almost about out of coffee.
LCDs are built with a fluid placed between two pieces of glass. There are three types of displays available: TN, STN and FSTN. Your choice of fluid determines how the display will look cosmetically.
TN types of displays are used in gas pumps, digital clocks and pagers (If you were born before say 1985 you will need to go to the Smithsonian < http://collections.si.edu/search/results.htm?q=pa...>to see what these were.)
Twisted Nematic [See photo below] was one of the first fluid technologies incorporated in LCD technology. The viewing angle is not as wide as STN or FSTN. Examples of TN LCD displays can be seen in pagers and gas pumps.
Film Compensated Super Twist Nematic [See image below] is considered a better fluid technology than TN or STN. It allows for better viewing angles and better contrast.
There are three types of LCD technologies that use nematic fluid: Character, Graphic and Segment. This is something to keep in mind when comparing FSTN vs TN fluids. Below is a photo and quick description. Note: all three of these can be customized to fit your needs.
Can display all numbers, some letters and custom icons. Great for products that need very low cost and low power. Tooling fees are cheap and we can have samples to you in a few weeks.
Character LCDs display all letters, numbers and punctuation marks. They can be built to display most languages. FocusLCDs carries inventory and in many cases can ship the same day you order.
Everyday, we look at LCD display, TV, cell phone, monitor. It becomes a necessity in modern society. LCD panel is the most important part of an LCD display. It determines LCD screen"s performance, e.g. brightness, contrast, color and viewing angle. Therefore, picking the right type of LCD panel is critical to your application.
These names reflect the alignment of crystal molecules inside the LCD, and how they change when they are charged electrically. All liquid crystal displays change the alignment of liquid crystal molecules to work, but the manner in which they do so can drastically affect the image quality and response time. Each panel type has its advantages and disadvantages. The easiest way to choose between them is to decide which attributes are most important to your project. It mainly depends on what you use your LCD display for, and your budget.
TN is the most mature technology in LCD panel manufacturing. When there is no voltage difference between the two transparent electrodes, liquid crystal molecules are twisted 90 degrees, in combination of upper and bottom polarizers, allows light to pass through LCD. As voltage applied, crystal molecules are untwisted and aligned to the same direction, blocking light.
In IPS panel, crystal molecules are parallel to the glass substrates at initial stage, LCD is off. When the in-plane electrodes is charged, crystal molecules are rotated, modifying light"s direction. Which lights up the LCD display.
So in summary, TN panels twist, IPS panels use a parallel alignment and rotate, while VA panels use a perpendicular alignment and tilt. These difference create LCD display with distinctive performance.
IPS LCD is the clear winner in this aspect. It has 178/178 viewing angle ratings. Which means you can look at IPS LCD display from any angle without the image shifting in color and contrast. VA LCD has pretty wide viewing angle, too. But it has contrast shifts at off-center angles. As for TN LCD, viewing angle is its weakest point.
Most TN LCDs have 6-bits colors. Manufacturers use frame rate control (FRC) to enhance its color performance. For IPS and VA panels, you can still find 6-bits entry level LCD. But most of them are 8-bits. And IPS technology can provide natively 10-bits colors.
Color gamut is another part that VA and IPS panels shine at. The best TN LCD can reach sRGB gamut. VA panels typically start with full sRGB coverage, and get to around 90% DCI-P3 coverage. With IPS LCD panel, you could find the best ones full DCI-P3 and Adobe RGB coverage. That is why you see most professional grade LCD displays use IPS panel.
There is no inherent differences among the three panel technologies, because LCD backlight is the main factor here. However, there is a big gap in terms of contrast ratio. TN LCD panel tends to have the lowest value among the three. IPS LCD screen sits in the middle can reach 1500:1. For VA panel, the best one can exceed 4500:1 easily. VA LCD display provides far darker screen than TN & IPS. That is why they are used in vehicle dashboard.
TN panel does have an advantage when it comes to refresh rate. The panel offers the best refresh rate and response time. This is the reason why most gaming LCD monitors are made of TN panel.
TN LCD provides the best refresh rate and economic solution. If your application requires wide viewing angles and good color presentation, VA panel is probably the choice. While IPS has the best overall visual performance, in general it is more expensive than the other two.
The tried and trusted TFT is the display of choice for most industrial designs, but it does have its limitations in viewability and colour vibrancy. But what about the relatively new technology, IPS (in plane switching) which has turned the TFT into a super-TFT? What are the benefits and drawbacks of each?
IPS derives its name from the fact that the liquid-crystal molecules are aligned in parallel with the glass plates, whereas the TN principle adopted in conventional TFT displays is based on perpendicular alignment of the molecules. In an IPS display, the crystals remain oriented in parallel whether the pixel is turned on or off.
A TFT display is a form of Liquid Crystal Displaywith thin film transistors for controlling the image formation. The TFT technology works by controlling brightness in red, green and blue sub-pixels through transistors for each pixel on the screen. The pixels themselves do not produce light; instead, the screen uses a backlight for illumination. Discover our TFT Products
Because the pixels block light when in the off state (the opposite situation to conventional TFT), IPS TFT exhibits high contrast and the background is true black when the display is powered down.
Display choice really does depend on your application, end user and environment. It may be a higher-grade IPS is needed to satisfy outdoor requirements, or a lower cost standard TFT display is sufficient. Before you make your choice, why speak with us and we will be happy to talk you through your options.
By far the most common types of display panels used on PC monitors are TN, IPS and VA. We"re sure you"ve heard these terms before if you"ve researched monitors to purchase, and to be clear, the type of panel is a key piece of information that reveals a lot about how the monitor will behave and perform.
TN is the oldest of the LCD technologies and it stands for twisted nematic. This refers to the twisted nematic effect, which is an effect that allows liquid crystal molecules to be controlled with voltage. While the actual workings of a TN-effect LCD are a little more complicated, essentially the TN-effect is used to change the alignment of liquid crystals when a voltage is applied. When there is no voltage, so the crystal is "off," the liquid crystal molecules are twisted 90 degrees and in combination with polarization layers, allow light to pass through. Then when a voltage is applied, these crystals are essentially untwisted, blocking light.
IPS stands for in-plane switching and, like all LCDs, it too uses voltage to control the alignment of liquid crystals. However unlike with TN, IPS LCDs use a different crystal orientation, one where the crystals are parallel to the glass substrates, hence the term "in plane". Rather than "twisting" the crystals to modify the amount of light let through, IPS crystals are essentially rotated, which has a range of benefits.
There are many IPS variants on the market, with each of the three big LCD manufacturers using a different term to describe their IPS-type technology. LG simply calls their tech "IPS" which is easy for everyone. Samsung uses the term PLS or plane-to-line switching, while AU Optronics uses the term AHVA or advanced hyper viewing angle. AHVA shouldn"t be confused with regular VA displays, it"s an annoying and confusing name in my opinion, but AHVA is an IPS-like technology. Each of LG"s IPS, Samsung"s PLS and AUO"s AHVA are slightly different but the fundamentals are rooted in IPS.
So in summary, TN panels twist, IPS panels use a parallel alignment and rotate, while VA panels use a vertical alignment and tilt. Now let"s get into some of the performance characteristics and explore how each of the technologies differ and in general, which technology is better in any given category.
By far the biggest difference between the three technologies is in viewing angles. TN panels have the weakest viewing angles, with significant shift to color and contrast in both the horizontal and especially vertical directions. Typically viewing angles are rated as 170/160 but realistically you"ll get pretty bad shifts when viewing anywhere except for dead center. Higher-end TNs tend to be somewhat better but overall this is a big weakness for TNs.
VA and IPS panels are both significantly better, with IPS being the best overall for viewing angles. 178/178 viewing angle ratings are a realistic reflection of what you can expect with an IPS, you won"t get much shift in colors or contrast from any angle. VAs are good in this regard but not as good as IPS, mostly due to contrast shifts at off-center angles. With VAs and especially TNs having some color and contrast shifts when viewing at angles, they"re not as well suited to color-critical professional work as IPS panels, which is why you see most pro-grade monitors sticking to IPS.
In terms of brightness there"s no inherent differences between the technologies because the backlight, which determines brightness, is separate to the liquid crystal panel. However there are significant differences to contrast ratios, and this an area most people look at when determining which panel type they want.
Both TN and IPS panels tend to have a contrast ratio around 1000:1, although in my testing I have noted some differences. TN panels tend to have the lowest contrast ratios when calibrated, with an entry-level panel sitting between 700:1 and 900:1 and good panels pushing up to that 1000:1 mark. IPS has a larger range, I"ve seen some as low as 700:1 like TNs, however the very best tend to push up higher than TN, with 1200:1 as the upper range for desktop monitors and some laptop-grade displays reaching as high as 1500:1.
Neither TN nor IPS get to the range of VA though. Entry-level VA panels start with a contrast ratio of 2000:1 from those that we"ve tested, with the best easily exceeding 4500:1, although 3000:1 is a typical figure for most monitors.
TVs make extensive use of VA panels and there contrast ratios can be even higher. It"s not unusual to see over 6000:1. So if you want deep blacks and high contrast ratios, you"ll need to go with something VA.
While IPS panels tend to be a middle ground for contrast they do suffer from a phenomenon called "IPS glow," which is an apparent white glow when viewing dark imagery at an angle. The best panels exhibit minimal glow but it"s still an issue across all displays of this type.
Color quality is another difference many people cite between TN displays and other display panels in particular. And this can be split into two categories: color depth or bit depth, and color gamut.
In both of these regards, TN panels tend to fall on the weaker end of the scale. Many TN displays, in particular entry-level models, are only natively 6-bit and use frame rate control, otherwise called FRC or dithering, to achieve standard 8-bit output. 6-bit panels are prone to color banding, while native 8-bit panels have smoother color gradients and therefore better color output.
Not all TN panels are 6-bit. The top-end TNs are native 8-bit, but it"s safe to say most TNs will only be native 6-bit, even today. If you are after a native 8-bit display, you"ll need to go with either IPS or VA, where many more panels come native 8-bit.
As for native true 10-bit, typically you"ll need to look for an IPS panel, which make up the majority of native 10-bit panels. Some VA panels can do it, but they are rare. Most displays you purchase that claim to be 10-bit, are actually 8-bit+FRC, with only high-end professional-grade monitors offering a native 10-bit experience.
This is another area where VA and IPS provide a superior experience. The best TN panels tend to be limited to sRGB, or in the case of the worst entry-level panels, don"t even cover the entirety of the sRGB gamut. Wide-gamut TN panels do exist, but they are rare.
With IPS panels, there is the largest variance. Entry-level IPS displays tend to offer 95% sRGB coverage or less, while the majority stick to full sRGB coverage. Then with high-end displays, usually for professionals, it"s not unusual to see full DCI-P3 and Adobe RGB coverage. Of all the wide gamut IPS displays I"ve tested, the lowest DCI-P3 coverage I"ve seen has been 93%, with over 95% a typical figure. This makes IPS the best technology for wide gamut work.
Throughout most of this discussion we"ve been talking about TN as the worst of the three technologies. So far, it has the worst color reproduction, contrast ratios and viewing angles. But it does have one key advantage, and that comes in the form of speed. TN panels have historically been the best for both refresh rates and response times, however that trend is slowly changing for the better.
Not long ago, we argued that only with a TN panel it was possible to hit 240 Hz, doing so at 1080p and later up to 1440p. Most recently, however we"ve seen IPS monitors hit the highest mark ever for a consumer-grade gaming monitor at 360Hz, and do so very convincingly. We"re sure other monitors will follow but as of writing, the Asus ROG Swift PG259QN can deliver both the fastest response times and an accurate color experience using an IPS panel.
Most IPS displays, especially high-grade options for professionals, as well as entry-level office monitors, are either 60 or 75 Hz. Meanwhile, a significantly larger number of VA panels across a wider range of sizes and resolutions are high-refresh, while the big selling point of TN is its super high refresh capabilities.
Another major consideration is response times, which govern the level of ghosting, smearing and overall clarity of a panel. Early IPS and VA panels were very slow, however this has improved a lot with modern panels, so the differences between the three technologies aren"t as pronounced as they once were. TN still holds an advantage here.
Most TN panels have a rated transition time of 1ms, or even lower with some recent releases. Actual grey to grey averages we"ve measured for TN panels tend to be in the 2-3 ms range when overdrive is factored in, which makes TN the fastest technology.
IPS panels are next in terms of speed, though as tends to be the case with IPS, there is a wide variance between the best and worst of this type. High-end IPS monitors, typically those with high refresh rates, can have a transition time as fast as 3ms. Compared to the best TN panels, this still makes IPS slower. However entry-level IPS panels or those without overdrive sit closer to the 10ms range, while mid-tier options tend to occupy the 5 to 7 ms bracket.
While a lot of people are unlikely to spot the difference between an 8ms VA panel and a 5ms IPS, TN panels overall tend to be noticeably clearer in motion, but that gap is closing with every generation. The slowness of VA panels also limits their real world refresh rate: a 144 Hz panel that only manages a 9ms response time, is actually delivering an image most equivalent to a 110 Hz panel. Whereas most 144 Hz IPS panels can transition faster than the 6.94ms refresh window, leading to a true 144 Hz experience. So that"s something to consider.
As a quick summary, TN panels are the fastest and have the highest refresh rates, however they have the worst viewing angles by far, as well as weak color performance and typically the lowest contrast ratios. TNs are typically used for ultra-fast gaming displays, as well as budget class displays, for both desktop monitors and laptops.
IPS is a middle-ground technology. They typically have the best color performance and viewing angles, mid-tier response times and refresh rates, along with mid-tier black levels and contrast ratios. Due to its top-end color output, IPS panels are the go-to choice for professionals, but you"ll also find them in entry-level displays, office monitors, most laptops and a handful of gaming monitors.
VA panels are the slowest of the three, but have the best contrast ratio and black levels by far. Color performance isn"t quite at the level of IPS, but they still offer a significantly better experience than TN in this regard.
With response times for the best modern VAs approaching the level of a typical IPS, along with broad support for high refresh rates, VA monitors are commonly used for gaming monitors. Entry-level VAs also tend to be superior to entry-level TN and IPS panels, though you won"t find VA used in laptops.
There"s no right answer to which monitor technology is best, because all have their strengths and weaknesses which is why all three coexist on the market today. However if you want our recommendation, we tend to gravitate towards VA panels for most buyers, especially gamers and t