lcd display viewing angle in stock

In this episode of the Display 101 series, we explain the viewing angle of smart displays. How to choose the right viewing angle for your project? Read on to get the answers.

This concept is closely related to the grey scale inversion phenomenon. When the user exceeds a certain angle (monitor viewing angle), one can note a sudden change in displayed colors. It mainly emerges with the grey color’s domination in the displayed image.

The viewing angle monitor has is measured from the display’s normal axis to each of the four directions. Theoretically, the maximum LCD view angle is 90° and might vary for each measuring direction. The three-dimensional angular range is called a viewing cone.

TN type is the most cost-efficient technology. In TN type the angles are in most cases narrower, compared to other types.  Low prices and short matrix reaction time compensate for the smaller viewing cone. To extend the monitor viewing angle, you can add theO-film to the display. When buying a TN-type display you should always pay attention to the viewing direction expressed in an hour angle. It describes the direction from which the user should look at the display.

IPS matrix technology has most of VA’s advantages. It also has incredibly good color reproduction and the highest viewing angles on both axes. The most common IPS disadvantage is the black color depth which is lower than in the VA type.

If the application requires a high viewing angle monitor, choose the display with full viewing angles (178.5°~180° on each axis). In this case, you should look for MVA and IPS type displays.

NOTE: Do not mistake the viewing direction with greyscale inversion. Greyscale inversion is always opposite to the viewing direction. For example, the 12 o’clock display will have a color inversion at 6 o’clock.

The in between solution is the TN type with viewing angles extended by adding O-film. We described the O-film solution in one of the earlier articles:

We hope you enjoyed this post from the Display 101 series. If you would like us to explore a particular topic in this series, send us a message or comment on our social media.

When customers compare your product with your competitor"s, correctly choosing the LCD viewing direction makes all the difference between a product that looks ‘okay,’ and a product that can grab and hold your customer"s attention. If the display on your product looks sharp, the whole product will look sharp. This can be accomplished at no extra cost simply by understanding how to locate the optimum viewing angle.

LCD display modules are built to provide the sharpest contrast and readability in one of four directions called the ‘the viewing angle’ or ‘optimum viewing direction.’ These four directions follow the format of a clock. With twelve o"clock viewing (12:00) being the top view and six o"clock (6:00) the bottom.

When specifying the best viewing direction for your new design, put yourself in the place of your customer. “From what direction will this display be viewed?” In other words, where will your end user be standing when they use your product?

Whereas a very tall person, say 6’5” or taller, pumping gas into their car, would look down at the LCD display, watching their dollars fly by as they fill up the tank. This would be a twelve o’clock (12:00) or top view.

Two other possible viewing angles include: Three o’clock (3:00 or left side view) and nine o’clock (9:00 or right-side view), however these angles are rarely used, 6:00 view is the default value for 80% of all monochrome displays. So, if you’re not sure which viewing angle to choose, go with 6:00.

There is no cost difference between viewing angles, but for TFT"s there may be a longer lead-time or MOQ (Minimum Order Quantity) than for monochrome displays.

Updated: Oct 28, 2019:Despite all the advances in LCD display technology viewing angle is still an important topic, panel viewing angles are still poor, good, better and best, but none are 100% perfect.

The viewing angle of an LCD panel is typical given based on the normal aspect ratio which is generally landscape for the types of LCD panels we work with. It is quoted for both horizontal and vertical in degrees from perpendicular to the display or as a total of left & right and up & down. So for example the newer IPS panels now claim up to 89 degree viewing angle from perpendicular for both horizontal and vertical.

Specifications are no replacement for actually seeing and evaluating an LCD panel, the reason is that there can be characteristics that the specifications don’t mention. For example I have seen an LCD panel with excellent viewing angle specifications but when testing it I could see a color shift at around 45 degrees from perpendicular.

Further to the previous point, even though LCD panel specification may quote H (horizontal) & V (vertical) viewing angles the performance in portrait model may be quite different to landscape mode.

I realize not every application needs or even suits having a wide viewing angle. Digital signage displays clearly benefit from a wide viewing angle if used in a poster or menu board but some overhead information displays need a good 6 o’clock viewing angle, ie when viewed from below, but the 12 o’clock viewing angle may not be critical.

IPS panels have had quite a few years of being a leading technology for excellent viewing angle with not only impressive specifications but genuinely excellent results. More recently companies like AUO have been showing panels with a new technology that appears to provide not only equivalent viewing angles but also excellent color fidelity over the range of viewing angles.

At this time the viewing angle of a LCD panel is not a tunable setting, it is a fixed part of the LCD panel design. Filters can be added by reworking the panel or adding to the front but these will typically limit rather than extend the viewing angle.

I was in a large computer store looking at computer LCD monitors and a lady was asking about which one was the better one to buy. A man (presumably her family) told her that the ones which indicated TFT (Thin Film Transistor) were the ones to buy. I then interjected that everything was TFT and it"s been that way since the extinction of those ugly STN passive matrix LCDs 8 years ago they use to sell with the cheaper laptops. Of course this invariably invited more questions as to which LCD was the better buy and better quality so I spent a few minutes showing them some of the shortcomings to many of these displays.

The first thing I noted was the poor viewing angle of every LCD on the display with the exception of a single model. To see this in effect, simply lower your head a few inches in front of the monitor and you will see the brightness of the entire display dim dramatically. Looking at the display from the bottom makes the image almost darken to the point of being black with some weird hues showing. Many of these displays don"t even look right when viewed at a slightly down angle since the color will change drastically. Case in point, look at the photos below of a typical LCD monitor which uses the most common TN (twisted nematic) technology.

What"s extremely frustrating is that the manufacturer claims that this display has a vertical viewing angle of 160 degrees. Yet the image above came from a photograph shot at 50 degrees above and below which indicates a 100 degrees spread. If we wanted to be extremely generous, we could say that the top-down view pictured bottom left is barely acceptable (it isn"t as far as I"m concerned), but the bottom-up view is flat out atrocious and there is no way in hell you can tell me that"s an acceptable image at this viewing angle.

In reality, the usable viewing angle of this display vertically is about positive 35 degrees to negative 10 degrees at best and that"s being generous. But looking at the vendor specifications, there is no way that you as the consumer would know this when you"re making the purchase. Now I don"t have a problem with the actual specs at the price they"re selling it at, but I do have a big problem with the deceptive advertising.

Only one of the LCD monitors out of about 30 models being shown on the show floor was viewable from all angles and it was most likely using PVA (Patterned Vertical Alignment) technology but it was about 30% more expensive than other displays of comparable size. It looked like something like the image below which is actually quite viewable at any angle. Furthermore, these displays typically offer true 8 bit per color or even 10 bits per color whereas the TN type displays are limited to 6 bits per color.

So the old adage that you get what you pay for holds true when it comes to LCD monitors, but manufacturers need to be honest with their customers. I purposely avoided singling out any single manufacturer because they all do the same thing, but this kind of deceptive advertising needs to stop.

LCD is a backlight display device. The light is provided by the backlight behind the LCD module. When the backlight passes through the polarizer, liquid crystal, and orientation layer, the output light has directivity. That means most of the light is coming straight out of the screen. Therefore, when you look at the LCD from a large Angle, you can’t see the original color, some time even just white or black color can be seen. The Angle (left and right, up and down) at which the original color appears on the screen is called the Viewing Angle of TFT LCD display Screens.

There are different visual effects from different view angle when viewed from the middle and side of the LCD display screen, the intensity of light entering the human eye is different. For the same picture, there is light and dark part, and the contrast is different. With the definition of perspective, the corresponding perspective of the LCD screen is perspective within the acceptable contrast range of human eyes.

As long as the horizontal viewing angle reaches 120 degrees and the vertical viewing angle reaches 140 degrees, the LCD on the market can fit the application needs of most users. The latest LCD screens are made with wide-angle technology, which can reach up to about 150 degrees, reducing the inconvenience caused by the small viewing angle.

There are 3 popular techniques for a wide display viewing angle so far, which are TN+FILM, IPS(in-plane -SWITCHING), and MVA(multi-domain VERTICAL alignment).

Add a layer of wide-viewing angle compensation film. This compensation film can increase the visual Angle to about 150 degrees, which is a simple and easy method and is widely used in LCD.TN+FILM may not be the best solution for manufacturers, but it is the cheapest solution, so most Taiwanese manufacturers use this method to build 15-inch LCDs.

The technology is the LCD panel technology introduced by Hitachi in 2001. The biggest feature of the IPS panel is that its two poles are on the same surface. Since the electrode is in the same plane and the liquid crystal molecules are always parallel to the screen in any state, the opening rate and the light transmittance will be reduced. Therefore, the application of IPS in LCD TV requires more backlights.

The advantage of the IPS panel is high visual Angle, fast response, accurate color restoration, cheap price. However, the disadvantage is that the light leakage problem. And the black purity is not enough, which is slightly worse than PVA. So it needs to rely on the compensation of optical film to achieve better black purity. Compared with other types of panels, the screen of the IPS panel is relatively “hard”, and it is not easy to appear water pattern deformation with a gentle stroke of the hand, so it is called a hard screen.

The idea is to add protrusions to form multiple visible areas. The liquid crystal molecules are not arranged vertically at rest, but horizontally when a voltage is applied, allowing light to pass through the layers. MVA technology improves viewing angles above 160 degrees and provides a shorter response time than IPS and TN+FILM.

In the MVA (multi-domain vertical alignment) display technology, horizontal and vertical viewing angles are wider than those of the first two technologies, and there is basically no blind Angle or bright spot. The viewing Angle is divided into horizontal and vertical viewing angles. The horizontal viewing angle is the viewing range from the center of the vertical central axis to the left and right. The vertical viewing angle is the viewing range from the center of the horizontal center axis to the up and down. Viewing Angle takes “degree” as the unit. Currently, the commonly used annotation form is to mark the total horizontal and vertical range directly, such as 150/120 °. At present, the lowest visual Angle is 120/100 ° (horizontal/vertical), which cannot be accepted if it is lower than this value.

If you are interested in STONE TFT LCD module manufacturers or have any questions, please feel free to contact us, we will wholeheartedly for your service.

This monitor will display a 250:1 contrast ratio when viewed head on or at a 90° angle from the surface of the monitor. The contrast ratio will decline as you view the display from the side eventually going down to 10:1 or 5:1 contrast ratio at an angle of 70° from head on. As you move away from the maximum contrast at the straight on viewing position, the brightness of the white may increase or decrease and the black may increase or decrease. However, the contrast (ratio of the two) will decrease as you move away from normal viewing. Please note, this is just a general representation and not factual for every monitor with 140° viewing angle. All values are estimates.

Other factors such as the display"s brightness, ambient light and contrast conditions all play a part in the readability of the display. As mentioned above, viewing angle is defined using only the contrast ratio. However, even within this standard viewing angle, the colors or tones on the display panel may look different from the real color/tone, or they may become invisible, depending on the combination of displayed colors (background color, text color and switch color). For example, if the background color is bright and you look at the screen from below, the colors may appear inverted so that the text color and switch color darken to the point where they become invisible. Or, when the background color is dark and you look at the screen from above, the colors may again appear inverted, so that the text color and switch color brighten to the point that they become invisible. As a result, be sure to choose your screen colors carefully, so they produce an effective combination for the LCD panel"s operation environment.

Early LCD monitors had some pretty awful issues when not viewed from directly in front of the screen. These days the technology has really minimized this flaw, but if you still have a cheap monitor on hand you might want to pull it out and give this hack a try. [Chris Harrison] is using oblique viewing angles to display additional information on cheap montiors.

This works because of the polarizing filters on an LCD screen. You might want to watch [Bill Hammack] explain how an LCD works if you’re not familiar. Because the viewing angle color changes are a flaw and not a feature, manufacturers make the up-and-down angles the worst to improve on side-to-side viewing. [Chris’] experiments play into that by using a computer monitor on its side. Check out the video after the break to see some of the different applications that he uses this for.

If you usually watch TV alone from directly in front, you most likely don"t need a wide viewing angle. You should just turn the television to face you directly. However, if you watch TV with multiple people in a wide seating arrangement, you should benefit from wide viewing angles as those viewing off-center still see an accurate image.

Also, viewing angles have an effect if you sit very close, and in particular if you use the screen as a computer monitor. If you sit too close to the screen of a TV with narrow viewing angles, the edges of the screen might look darker and washed out. If it has wide viewing angles, however, the image remains accurate no matter where you sit.

There are a few competing TV technologies and panel types that each present their advantages and disadvantages regarding viewing angles. For LED-backlit LCD TVs, the LCD panel technology used is a big determining factor for how well a TV retains picture quality at an angle. There are two main types used in TVs: IPS and VA, and the differences between each panel type are noticeable; you can learn more about them here.

IPS panels are superior to VA panels when it comes to viewing angles. They"re generally recommended for wide seating arrangements because the image remains accurate when viewing from the side. On the other hand, the image on a VA panel quickly loses accuracy as you move off-center, and it can get pretty noticeable when sitting at a wide angle. This doesn"t mean IPS panels are perfect, however, as they have a lower contrast ratio than VA panels, so choosing one type over the other is a trade-off between viewing angles and contrast.

OLED is a different technology that uses self-emissive pixels. Each pixel turns itself on and off and emits light in all directions. This means that OLEDs have very wide viewing angles, even better than IPS panels, and they also have a near-infinite contrast ratio.

To improve viewing angles on VA panel TVs, companies have introduced viewing angle technology, like Samsung"s "Ultra Viewing Angle" and Sony"s "X-Wide Angle". This improves the viewing angles a bit at the cost of its contrast, but the contrast still isn"t as low as IPS panels. These TVs meet a common ground between viewing angles and contrast, without a decrease in overall picture quality. Samsung and Sony are the only two major manufacturers that have introduced such technology, and they"re generally only available on higher-end models.

Although our tests for horizontal viewing angles get into detail about different aspects of the picture quality, it"s easy to see the effects of viewing angles for yourself at home. If you look at any display at an angle, whether it be your monitor, TV, phone, or tablet, does the image look noticeably different from when you"re viewing it from directly in front? If you don"t notice any difference, it means the display has wide horizontal viewing angles. Most phones and tablets have wide viewing angles because we look at those displays from a variety of positions. Many LED TVs and some monitors have narrow viewing angles, so if you walk around the display, you"ll notice how the colors start to change or the image looks darker.

In terms of testing, we use a colorimeter to measure changes in color, brightness, black level, and gamma when the monitor is at an angle. We use a Colorimetry Research CR-100 Colorimeter, which is calibrated to the monitor, and then it measures the color, brightness, black level, and gamma at different angles. The results and graphs are automatically generated in the Octave software. However, we also record a video to visually see the viewing angles, which is easier to understand than the graphs. We measure with the colorimeter up to 70 degrees off-center, and our video includes a full 180-degree rotation, but our scoring only counts the colorimeter"s measurements.

Throughout this article, we"re going to compare monitors: the Dell S2721DGF, which has wide viewing angles, and the LG 32GK850-B, which has narrow viewing angles. As you can see, the image remains accurate when viewing off-center on the Dell. No display has perfect viewing angles, so you still notice some color shift at very wide angles, but most people aren"t looking at monitors from the side like that. On the other hand, the image on the LG starts to look different as you move off-center, and the decrease in image quality happens more quickly.

Color washout is when colors start to lose their chroma, or when they lose their saturation. If you"re looking at a standard blue color, it loses its chroma when it starts to look blue/gray and it"s not the same color anymore. To test for color washout, we measure pure red, blue, and green, and we measure the angle at which each color drops to 80% of its original chroma. These graphs aren"t very difficult to read; the x-axis represents the viewing angle and the y-axis represents the color"s chroma.

Color shift is similar to color washout, except we"re looking at the change in a color"s hue. The hue defines how close a color is to one of the six main colors: red, orange, yellow, green, blue, and purple. A shift in hue changes the color and makes it either appear more red or blue, depending on which end of the color spectrum it"s changing to. Once again, we measure red, green, and blue, and test to see at which viewing angle the hue changes by more than 3 degrees. In the graphs below, the acceptable hue shift range is marked by the horizontal black lines. If a color increases or decreases past these lines, it"s considered a color shift.

These graphs are a bit more difficult to read than color washout, but you can see how green and blue retain their hue for a wide angle with the Dell; only red starts to change sooner. The LG is actually outstanding at retaining the color hue, so instead, we"ve shown the graph for the MSI Optix G27C4, which isn"t as good. You can see that all three colors, especially red, start to lose their hue a lot sooner.

In this test, we don"t measure if the monitor loses brightness and becomes dim, but rather we measure how much it loses its lightness. In other words, at which angle does the image start to appear darker? We measure the lightness using six test slides: pure black, 20% gray, 40% gray, 60% gray, 80% gray, and pure white, and we measure each slide at various angles. The pure white slide has a lightness measure of 1.0, while pure black is 0.0, and we want to see when the lightness of any of the slides drops to 75% of its original value.

As you can see, the image retains its brightness at wider angles on the Dell than the LG. Pure white drops to 75% of its original lightness at about 50 degrees on the Dell and less than 30 degrees on the LG. Also, pure black actually becomes lighter on the LG at very wide angles, meaning it"s not pure black anymore.

Black level defines how bright the screen is when displaying its darkest dark. A monitor that can display deep blacks has a low black level because it"s not emitting much light. However, monitors with low contrast have blacks that appear gray, meaning there"s still some light coming out. The black level raise measures when the black level doubles its lightness, causing blacks to appear gray. In the case of the Dell, the black level raise is measured at 70 degrees, meaning the blacks look the same at wide angles. However, the LG has a black level raise of 18 degrees, so blacks look closer to gray than pure black when viewed from the side.

Gamma defines the brightness of shades of gray. Having a monitor with a proper gamma is important for scenes or games with shadows. If gamma is too high, the image appears too dark and you lose some details in the shadows. If gamma is too low, the image is too bright. Using the same grayscale slides from the brightness loss test, we want to see at which angle do those grays shift by 3% from their relative position between pure black and pure white. Essentially, we test for which angle the grays start to change. Looking at the graphs above in brightness loss, you"ll notice there are dotted lines, and these represent the ideal gray value relative to pure white and pure black. If the grays start to deviate from the dotted lines, it means gamma is shifting. As you can see, the Dell maintains gamma stable for wide viewing angles, while the LG starts to shift at narrow viewing angles.

The type of panel used has a huge impact on the viewing angles. There are three common types of LCD LED-backlit panels: IPS (In-Plane Switching), VA (Vertical Alignment), and TN (Twisted Nematic). IPS is the only one out of the three known to have wide viewing angles. The other two have their own unique features, such as a high contrast ratio on VA panels and fast response times on TN, but you lose image accuracy when viewing from the side on each of those.

Many monitors have IPS panels so the image remains accurate whether you sit up close or if you need to share your screen with a coworker. Not all panels are perfect though as we"ve seen IPS panels that have a quick color washout, such as the Acer Nitro XV340CK. If the monitor has a VA panel, it has narrow viewing angles, and the edges of the screen may start to look inaccurate if you sit too close, so some monitors have curved screens to bring the edges more within your vision, such as the Dell S3221QS. As for TN panels, those are generally found on older models and colors start to shift very quickly, so unless you look at it from directly in front, the image looks inaccurate.

There"s also another panel type that isn"t very common with monitors but is popular with TVs: OLED. These displays use self-emissive technology to turn individual pixels on and off, and each pixel emits light in all directions, resulting in wide viewing angles. Even if you use an OLED TV as a monitor, like the LG 48 CX, the image remains accurate no matter where you sit. However, most monitor manufacturers are still reluctant to use OLED panels because of the risk of permanent burn-in.

There isn"t anything you can do to improve the viewing angles of a monitor, besides getting one with an IPS or OLED panel. If you already have a monitor with a VA or TN panel, make sure it"s centered in front of you and you don"t sit too close so that the edges of the screen look different. If you often need to share your screen with someone around you, it"s ideal to get a monitor with an IPS panel to get those wide viewing angles.

A monitor"s horizontal viewing angles greatly affects the way we see an image. One with wide horizontal viewing angles means that the image remains accurate when viewed from the side, which is ideal if you need to share your screen with others around you. However, if the monitor has narrow viewing angles, colors start to look different when viewing from the side. Most monitors have an IPS panel, which provides wide viewing angles, but if you"re the only one using the screen, and it"s placed directly in front of you, you shouldn"t have to worry about the viewing angles.

As an active-matrix LCD device, the TFT LCD’s individual pixels consist of red, green, and blue sub-pixels, each with their own TFT and electrodes beneath them. These sub-pixels are controlled individually and actively, hence the name active-matrix; this then allows for smoother, fast response time. The active-matrix also allows for larger display modes that continue to uphold quality of color, refresh rate, and resolution when aspect ratio is increased.

Within the pixels composing the TFT LCD display, electrodes play a role in conducting the circuit between them. If layered on both insides of the two glass substrates, the electrodes, along with the TFT, create an electrical pathway within the liquid crystal layer. There are also other placements of electrodes besides on the surface and back of the device that change the effect of the electrical pathway between the substrates (to be discussed later in this article). This pathway has an effect on the crystals through its electric field, which is one of the TFT concepts responsible for the low, minimized power consumption of TFTs, making them so efficient and appealing.

Though there are a variety of ways to align the crystal molecules, using a twisted nematic (TN) to do so is one of the oldest, most common, and cheapest options for LCD technology. It uses the electric field between the electrodes organized with one on the surface substrate layer and the other on the back substrate layer to manipulate the liquid crystals.

If an electric field is applied, the twist in the crystal structure of the molecules can be unwound, straightening them out. When this happens, the light is not polarized and cannot pass through the surface polarizer, displaying a black pixel. It is also possible to create an in between of the fully lit or fully opaque pixel; if the light is partially polarized (the electric field does not fully straighten the crystal alignment), then a middle luminance level of light is emitted from the LED backlights through the polarizer.

Though this is one of the cheapest options for display technology, it has its own problems. The TN TFT LCD does not have top response times compared to other types, and it does not provide for as wide a viewing angle as other TFT LCDs using different alignment methods. A viewing angle is the direction at which a screen can be looked at before the displayed image cannot be seen properly in terms of light and color. TN displays mostly struggle with vertical viewing angles but also have somewhat limited horizontal angles as well. This TN LCDs viewing angle limit is called the gray scale inversion issue.

Generally, when viewing angle is not ideal, image quality as a whole decreases. Things like contrast ratio (the luminance ratio between the brightest white and darkest black) and readability of the screen are not preserved due to this issue.

Among the methods of liquid crystal alignment, TN is only one option for LCD technology. There are various other common ways to align the crystals for a wide viewing angle, such as the multi-domain vertical alignment or in-plane switching. In addition, because of the abundance of TN devices, something called O-film has also been introduced to pair with TN screens so that users do not have to buy whole new devices.

Simply put, this method divides the cell beneath each pixel into multiple domains. With the division, molecules in the same cell can be oriented differently, and so as users shift their views of the display, there are different crystal directional alignments that allow for the preservation of the display properties over these angles such as high brightness and high contrast. This solves the problem of what is known as a mono-domain vertical alignment.

Though mostly similar to the TN, the MVA has one notable feature in its cell that TN cells do not have: glass protrusions. Between the sandwiching electrodes, angles glass protrusions reorient the light traveling within the layer so that when exiting the surface polarizer, it travels in a multitude of directions to satisfy the need for a wide viewing angle.

In recent developments of the MVA TFT LCD, contrast ratio, brightness, and response times have all increased in quality. Contrast ratio, being 300:1 when first developed in 1997, has been improved to 1000:1. Similarly, response time, characterized by rising (black to white) and decay (white to black) time, has reached times that are the fastest that human eyes can process, demonstrating the appropriateness of MVA-based displays for moving images.

With this type of alignment, viewing angles were preserved in much wider directions compared to the TN. Recently, IPS displays have improved qualities like response time to make the IPS screens more desirable to consumers. However, this type of TFT LCD will tend to cost more than TN devices.

While the TN TFT LCD has the smallest cost, that is for a reason. O-films, MVAs, and IPS TFT LCDs have greater costs due to their more intricate technologies that improve viewing angle to retain resolution and general display quality.

The O-film specifically is unique because rather than changing the liquid crystal alignment technology and for a relatively low cost, it can swap the surface polarizer of a TN device with a special film to widen the viewing angle. Because it is combined with TN, it can only improve viewing angle slightly.

IPS has the most potential for improved viewing angle, reaching higher possible angles than all the other options. With IPS, though, there is a higher power consumption than the regular TN device due to the need for a brighter backlight in this device.

All these technologies are viable options depending on the consumer’s desires and price range. MVA and IPS TFT LCDs tend to be more practical for consumer products like LCD monitors and phone screens, while TN and O-film LCDs can cross over into industrial applications. Nonetheless, with the growth of the IPS and MVA LCDs, their applications are widening.

The AFFS is similar to the IPS in concept; both align the crystal molecules in a parallel-to-substrate manner, improving viewing angles. However, the AFFS is more advanced and can better optimize power consumption. Most notably, AFFS has high transmittance, meaning that less of the light energy is absorbed within the liquid crystal layer and more is transmitted towards the surface. IPS TFT LCDs typically have lower transmittances, hence the need for the brighter backlight. This transmittance difference is rooted in the AFFS’s compact, maximized active cell space beneath each pixel.

Since 2004, Hydis, who developed the AFFS, has licensed the AFFS to the Japanese company Hitachi Displays, where people are developing complicated AFFS LCD panels. Hydis has improved display properties like outdoor readability of the screen, making it even more appealing to use for its main application: mobile phones displays.

picture and performance seen from a 45�viewing angle position to their picture and performance seen from the ideal 0�Sweet Spot. For all the tests we used the most color

With this issue, we bring you a new contributor, Dr. Raymond Soneira, a research scientist with a career that spans physics, computer science, and television system design. Dr. Soneira obtained his Ph.D. in Theoretical Physics from Princeton University, spent 5 years as a Long-Term Member of the world famous Institute for Advanced Study in Princeton, and another 5 years as a Principal Investigator in the Computer Systems Research Laboratory at AT&T Bell Laboratories. He is currently President of DisplayMate Technologies Corporation of Amherst, New Hampshire, which produces video calibration, evaluation, and diagnostic products for consumers, technicians, and manufacturers.

Dr. Soneira, who has authored over 35 research articles in scientific journals in physics and computer science, including Scientific American, frequently stages “shoot-outs” where he methodically documents the actual facts of video display performance – facts often at odds with conventional wisdom and marketing claims.

One recent display technology shoot-out provided the first public study of chromaticity variations with viewing angles. Dr. Soneira has graciously agreed to share these results with CalMAN users. Experienced calibrators have learned the hard way to be very careful with viewing angles, but Dr. Soneira’s research documents for the first time exactly how pronounced the angular effects can be.

Everyone knew there were viewing angle effects, but our side-by-side tests showed how incredibly large they actually are. The differences were amazing and astonished everyone that came to see and compare the HDTVs side-by-side, including industry experts, manufacturers, engineers, reviewers, journalists, and ISF instructors.

Figure 1 shows the variation in color with Viewing Angle for each of the tested units. This effect is due to the fact that for bright LCD sub-pixels the brightness decreases with Viewing Angle and for dim subpixels the brightness increases with Viewing Angle, which can in some cases lead to contrast reversal. Since this occurs independently for each of the Red, Green, and Blue sub-pixels that produce the entire gamut of colors seen on-screen, it leads to a rather complex behavior of brightness and color variation with Viewing Angle. Color mixtures show the greatest variations with angle, but displays are engineered so that things balance out for whites and grays, which are particular mixtures of all of the primary colors together.

All of the LCD units have a noticeable color shift at less than ±15 degrees, while the Panasonic Plasma is visually indistinguishable from face on viewing well beyond ±45 degrees. This is true for both the measurements and the viewing tests. The significance of this is enormous, because it means that the “sweet spot” for seeing an accurate picture on an LCD HDTV is only one person wide, even for these top-of-the-line models, so essentially everyone looking at an LCD HDTV will see a picture with noticeably different coloration.

Third: unfortunately, it gets even worse for LCD HDTVs that have an Extended Color Gamut, such as the Sony and Samsung units, which show additional and much stronger Viewing Angle artifacts than LCDs with a standard HDTV color gamut, such as the Sharp unit. Right now there is essentially no commercially available content with an Extended Color Gamut, so this feature is just a marketing gimmick. But a gimmick with a significant penalty for all of the current content with a Standard Color Gamut. This is because the standard HDTV primary colors for these units must be generated as color mixtures of the native extended gamut primary colors, and those color mixtures then vary with viewing angle just like the other colors. As a result a much larger fraction of the HDTV color gamut shows a strong variation with angle. The Sharp unit does not have an extended color gamut and as a result performed much better with primary colors than both the Sony and Samsung units. Figure 2 repeats the measurements and analysis with angle for the pure Red and Green HDTV primary colors in order to examine the effect of Extended Color Gamuts. The Sharp LCD and Panasonic Plasma have only a small shift in primary color chromaticity with angle, while the Sony and Samsung units both show very large variations with angle.

The best examples were the two units with the best picture quality: the Sony LCD and the Panasonic Plasma, which were set right next to one another. Their calibrations were both so close that it was frequently impossible to visually tell them apart. But that was true only when standing exactly dead center in front of the Sony unit. Shifting left or right by just one foot at an optimum viewing distance of 7 feet caused the Sony LCD unit to appear noticeably different from the Panasonic Plasma unit next to it, which delivered a consistent picture independent of viewing angle. This same effect also applies to vertical viewing positions and angles, so don’t even think about mounting your LCD HDTV above the fireplace! Make sure that the center of the TV is close to your normal viewing eye level.

The shocking conclusion is that only one person at a time can see accurate color reproduction on a direct-view LCD HDTV, even on top-of-the-line units from the top manufacturers. Even when viewers are seated close together side-by-side, each person will see a different picture with noticeably different coloration. On the other hand, Plasma displays deliver very close to true 180 degree (±90 degree) viewing, the same as traditional CRT monitors. There is very little change in brightness, contrast, hue, or color saturation over the entire 180 degree viewing area.

A rather interesting method that we used to demonstrate these effects was to have people walk past the lineup of HDTVs while simultaneously viewing and comparing static photographs on all the HDTVs, and then seeing how the units drifted in and out of color accuracy as they walked by each unit. Static photographs are crucial for evaluating picture quality and accuracy because they stay the same throughout the entire test, whereas live video is constantly changing so a detailed comparison and evaluation, even between two units, cannot be done using that method.

Figure 3 is a set of photographs taken at 0 and 45 degrees in front of the Panasonic Plasma and the Sony and Sharp LCD units. These screen photographs demonstrate the change in color with viewing angle for the test units. When viewed in person the differences were much more pronounced than they appear here in these printed thumbnails, which are affected by the Transfer Function of the camera and the printing process.

Every aspect of the light imaging system in Pro Display XDR is crucial to the overall quality of what you see onscreen. Each element builds on top of the last to create a display with unbelievable brightness and contrast.

Typical LCDs are edge-lit by a strip of white LEDs. The 2D backlighting system in Pro Display XDR is unlike any other. It uses a superbright array of 576 blue LEDs that allows for unmatched light control compared with white LEDs. Twelve controllers rapidly modulate each LED so that areas of the screen can be incredibly bright while other areas are incredibly dark. All of this produces an extraordinary contrast that’s the foundation for XDR.

For even greater control of light, each LED is treated with a reflective layer, a highly customized lens, and a geometrically optimized reflector that are all unique to Pro Display XDR. Through a pioneering design, light is reflected, mixed, and shaped between two layers to minimize blooming and provide uniform lighting.

Converting blue light to white is a difficult process that requires extremely precise color conversion. It’s why most display makers use white LEDs. Pro Display XDR accomplishes this conversion with an expertly designed color transformation sheet made of hundreds of layers that control the light spectrum passing through them.

Pro Display XDR extends exceptional image quality to the very edge. To ensure that LEDs along the sides of the display mix well with adjacent ones, a micro-lens array boosts light along the edges. This creates uniform color and brightness across the entire screen.

With a massive amount of processing power, the timing controller (TCON) chip utilizes an algorithm specifically created to analyze and reproduce images. It controls LEDs at over 10 times the refresh rate of the LCD itself, reducing latency and blooming. It’s capable of multiple refresh rates for amazingly smooth playback. Managing both the LED array and LCD pixels, the TCON precisely directs light and color to bring your work to life with stunning accuracy.