lcd display viewing angle factory

Viewing angle is a very important factor when evaluating LCD display"s performance. Understanding how to locate the optimum viewing angle and choose the right LCD display will make your product looks sharp without extra cost.

LCD viewing angle is the maximum angle from which customer can view the screen well. "Viewing well" is commonly recognized as having at least 10:1 contrast and without grayscale inversion.

At time of manufacturing, LCD manufacturer designs LCD panel in a way that it is best viewed from an angle (called Bias) offset from the perpendicular by certain degrees, to accommodate as many applications as possible. Viewing angle is the angle covers both side of Bias angle, where the LCD is still "viewing well".

When reading an LCD"s specification, you will see the term "viewing direction". Viewing direction is defined following the format of a clock. Like figure below, Z axis is Normal, X axis is Horizontal and Y axis is Vertical. An LCD"s viewing angle "above" Z axis is having 12 o"clock viewing direction. So 6 o"clock viewing direction LCD is best viewed from "below" Z axis.

Theoretically, LCD manufacturer can produce LCD with 3, 12, 9 and 6 o"clock viewing direction. But in practice, we usually look at LCD display from 12 or 6 o"clock angle.

Using a simple TN type TFT LCD as example, its viewing angle is typically 45~65 degrees. Adding extra wide polarizer film (EWP) to the TN type LCD, the viewing angle may be increased about 10 degrees. Similarly, an O-film enhancement polarizer will widen the viewing angle to 75 degree in each direction. However, these enhancements bring along contrast reduction. Adjusting LCD contrast is necessary.

Using a liquid crystal display with proper viewing angle is very important to your product"s success. And we should keep in mind that optimized contrast is crucial, too. Both parameters define the visual appearance of the LCD display and the appeal of your product. Choices are based on cost performance trade offs.

For example, if your project requires a wide viewing angle 2.4" TFT LCD. TN TFT panel with O-film solution might be better than using IPS LCD. Topway engineers are here to help you making those design decisions.

When we introduced IPS in a previous article, we mentioned one of the biggest advantages was in viewing angle. In fact, there are a couple of different characteristics with respect to the direction of viewing. You may have heard of displays that boast of "Full Viewing Angles" or "Big Viewing Angle" in marketing. Today, we"ll unpack some of the elements of viewing angle and viewing direction.

The view direction is the sight direction marked with Φ which is with respect to the X-axis. The original location is the center point of the display panel surface, the Z axis is Normal, the X-axis is Horizontal and Y-axis is Vertical.

Normally it was defined 4 angles to correspond with 3, 12, 9, and 6 o’clock respectively. So you can find the 6 o’clock or 12 o’clock parameter in the display‘s datasheet.

View Angle is the angle with respect to the Z-axis in a certain direction and marked by θ (θU means upper View Angle). View Angle describes the maximum watching angle and it is one of the key indicators with the display module.

LCD uses light emission characteristic and control of the light brightness to form the grayscale. Based on the relationship of the light direction and the LC (Liquid Cristal molecule, same as below) direction, you can see that the left of Figure 3 shows the case if you look from a different direction. The light is parallel to LC long axis, the Phase Delay and Transmission Rate are small and it is dark if you look from below (6 o’clock).

The right side of Figure 3 shows the Gray Scale Inversion case. When looking from a certain angle and increasing the Electrode voltage, The LC will rotate to a larger angle and It will cause the angle of light and LC are close under maximum voltage and minimum voltage. It means that the Gray Scale is the same and we can see the scene of bright becoming dark and then bright following the voltage increase.

Because the LC angle and distribution are not fully symmetric, you can see the Gray Scale Inversion from a large angle. Gray Scale Inversion will cause bad display effect.

Normally we use Contrast Ratio, Gray Scale Inversion or Color Shift to define the View Angle. The View Angle is the critical angle in which the Gray Scale Inversion does not happen if you select the Gray Scale Inversion to defined it. They are not the same definition but the result is close. So, we should not care about the definition but our requirement.

View Direction can determine the best view direction and avoid putting the display in the wrong place. Normally the LCD View Angle is Vertical symmetry but not up and down. If you usually look down, the 12 o’clock is suitable. Of course, the view direction os great from this angle. (no difference of UDLR).

There is another method to mark the View Angle except Figure 1. For example, 160 degree means the total angle is 160 degree for up/down or left/right direction.

Sometimes we confuse the mark of View Direction. For example, we record 45/35/65/65 sort by U/D/L/R, someone says it is 6 o’clock (point out the Gray Scale Inversion direction), but another one says that it is 12 o’clock. So It is necessary to check in the datasheet to confirm the detail if you get a new display module. In one thought, the bigger angle is the best direction we should look at the screen from. From this, we can select the proper screen for our application.

In the end, that"s why all of this matters. For some applications, the viewing direction of the screen might be different from others. So, it"s very important to understand how the display will be used and what environment it will serve in. Characteristics like viewing angle and viewing direction become important differentiators, in the end, only if they match the final use case.

When your customer compares your product with your competitors, the correct choice of the LCD viewing direction makes the difference between a product that looks ‘okay’ and a product that grabs and holds your customer’s attention. If the display on our product looks sharp, your product looks sharp and this can be accomplished at no extra cost 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.’ The 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, (think David and Goliath) 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) but 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.

TFT (Thin Film Transistor) LCD (Liquid Crystal Display)technology is currently dominant in the display world right now due to its lightweight, low power consumption, low manufacturing cost, etc. But LCDs do have several generic drawbacks. A narrow viewing angle is one of the main issues compared with other display technologies, such asOLED (Organic Light Emitting Diodes), CRT(Cathode-Ray Tube), Plasma, VFD(Vacuum Fluorescent Display), and most recent SamsungMicroLEDdisplays. They also don’t have a response time issue.

LCD scientists and engineers took more than 30 years of effort to improve the TFT LCD viewing angle which has made TFT screens widely applicable in different applications ranging from automotive, home appliances, medical, military, industrial, consumer, etc. The following is a summary of the different TFT wide viewing angle technologies.

When we talk about TFT LCD, we normally mean TN LCD. Thetwisted nematic effect(TN-LCD) 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. Refer to Fig.1

In this case, when the display is observed from a vertical direction to the substrate, the display shows a dark state, because the optical axis of the liquid crystal is perpendicular to the substrate. However, when the display is observed from the tilted direction, the display does not show completely a dark state because light leaks due to the birefringence. The birefringence becomes predominant with an increase in the voltage. At different viewing angles, the birefringence is different and the transmission is different in each direction. This is the reason for the poor viewing angle of TFT LCDs. See Fig.3.

The most cost-effective and common way is to use a wide viewing angle polarizer. Of course, the improved viewing angle is not wide enough for some applications. Another limitation is that the wide viewing angle polarizer will not be able to change the Gray Scale Inversion shown at the bottom photo in Fig.3.

O-Film is an optical film that is applied to the TN TFT LCD and redirects light, providing all round viewing angles to any TN TFT LCD to which it is applied. It is easy to apply and relatively low cost.

This article is an original piece of content written by the engineering and technical support team atOrient Display. We are an LCD and display technology provider with over two decades of industry experience in delivering cutting edge display solutions. Please browse ourknowledge baseif you would like to learn more about LCDs!

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.

The switchable viewing-angle LCD gives the user the ability to switch between normal wide-angle display and narrow-angle display that guards against unwanted viewing from the side.

This new LCD technology provides protection that can be turned on and off according to the situation and will help boost future demand for mobile devices.

The switchable viewing-angle LCD gives the user the ability to switch between normal wide-angle display and narrow-angle display that guards against unwanted viewing from the side.

This new LCD technology provides protection that can be turned on and off according to the situation and will help boost future demand for mobile devices.

We all would look at the limited viewing angle as a problem. Not enough people can see the TV, colour is bad, blah blah. But if we were to look at the problem in reverse - Too many people can see the screen from all angles, colour acuracy is not that important for all applications, and so on... we actually define a product that we can fit in the banking, HR, etc roles.

The consumer television sector designed thinner displays and broader viewing angles to differentiate products and improve user experiences. These viewing angle improvements are now being adopted for the small-format industrial markets as well. What else can industrial display applications adopt?

By adding extra wide polarizer film (EWP) to the traditional TN cell, the viewing angle may be increased about 10-15 degrees in each direction. But this will result in one or two directions being much narrower than the other three.

Finally an advanced cell structure applying In-Plane switching (IPS) or Multi-Domain Vertical Alignment (MVA) cells can improve viewing angle approximately 85 degrees in each direction.

Quantum dot, another television-based innovation, can also be implemented. Quantum dot improves the color range of the cell. This is separate from viewing angle problems per se but it does relate to enhancing the overall viewing experience.

It’s important to understand that consumer display product life cycles are far too short for industrial applications to take advantage of. Consumer products are designed for 1-2 years, where industrial applications may last in production for over a decade. This is important as many TFT platforms are designed for consumer applications and run the high risk of becoming obsolete early in the production phase of an industry type product.

Because the industrial customer typically wants a 10-year production life and IPS and MVA cells typically become obsolete within a few years, a much more practical viewing angle improvement is adding an enhancement film to a more readily available TN cell structure.

Products have emerged requiring improved viewing angle performance, particularly eliminating reduced contrast and color shift, at increasing angles. These include consumer televisions, automotive and industrial applications where the LCD display location is fixed but the end user/viewer will be in various positions. Monitoring equipment, safety equipment, fixed AV systems, rack mount systems, test equipment, medical and automotive are all current application areas where these challenges come into play.

With the advent of the O-film, improving the viewing angle is now typically a choice between O-film on a TN display or a higher-end cell structure such as IPS and MVA. And that decision is based on either product availability and/or cost performance trade off.

If the end product application requires a wider viewing angle there are several options. Choices are based on cost performance trade offs or and/or product availability. For example, if your design requires a wide viewing angle 2.4” QVGA TFT and it is only available in TN, the only option is O-film. If this same display is also available in IPS, you have the cost/ performance trade off to consider as well as the shortened product life cycle and potential longer lead times of the IPC cell over the TN+O-film solution.

Your user interface may need to be seen from a wide variety of angles for various reasons. Multiple usersmay need to read the display or interact with your application at the same time. On the other hand, equipment like industrial machinery or home appliances can be safer and easier to use if menu items and instructions can be read from any angle. You can influence the viewing angle of your application in several ways, including through the choice of display technology and by applying a process such as optical bonding.

Optical bonding creates a permanent bond between the front surface of the liquid crystal display and the rear side of touchscreen, using a specially formulated Optically Clear Adhesive (OCA).The OCA works by matching the indices of refraction between touchscreen and LCD and completely fills the air gap that would usually exist between these two components.

The absence of an air gap means the amount of ambient light that would normally be reflected back at the user after entering the system and encountering the air gap and the surface of the display, will be significantly reduced. With this improvement, displayed colours appear brighter, more vivid and can be seen more clearly from acute angles. The resulting increase in brightness also means the backlight luminance can be dimmed to reduce the application’s power consumption.

Although including optical bonding into the display module structure will increase cost because additional materials and manufacturing processes are required for manufacturing the display, there are other benefitsto consider too.The absence of condensationforming in the gap between the display and touchscreen which can have a negative impact on optical performance as external temperatures fluctuate between warm and cold.

Increased impact resistance of the assembly, so if your application needs a high IK rating as well as wide viewing angles, including optical bonding to the structure can go some way to providing an effective solution. Find out more.

With In-Plane Switching (IPS) technology, also known as Super-TFT, the crystal structure and electrode placement are arranged to ensure that the molecules are always aligned parallel to the plane of the display. The backlight passes through when the cell is active and is shuttered when no voltage is applied.

IPS was developed specifically to ensure superior colour reproduction and stability, compared to conventional displays, while extending the viewing angle. Super-IPS displays emerged later, offering faster response time. IPS is often the best choice when high colour quality and minimal off-centre contrast shift are needed, at the same time as a wide viewing angle.

An MVA (Multidomain Vertical Alignment) display is designed so that the liquid crystal molecules are aligned perpendicular to the glass in several domains. This is achieved by texturing the inner glass surfaces in such a way as to allow the LCD molecules to remain in a perpendicular state until specific pixels in the region are selected. Selected pixels cause the LC molecules to reorient parallel to the glass in each of their domains which reduces the effect of birefringence, as seen in TN displays, perceived by the user when viewed from various angles.

As a result, the brightness and colour of individual pixels appear more uniform over a wider viewing angle. Even so, MVA falls between IPS and TN displays in terms of display quality and some consideration should be given to the type of information that your final application is intended to display. For example, MVA displays have slower response times therefore, if you want to present fast-moving animations this may not be the right solution. MVA displays can also exhibit colour shift at extreme viewing angles, which causes darker colours to appear slightly washed-out. Depending on your application, this could be an acceptable trade-off in exchange for wider viewing angles. It may be possible to mitigate the effects of colour shift by using lighter colours when designing your GUI.

There are several variations of MVA technology, such as Super-MVA (S-MVA), which offer superior performance in terms of contrast, response time, and viewing angles.

In summary, each of these approaches to improving the viewing angle may be suitable for your application, depending on aspects such as cost, power consumption, the type of content you need to display, and the operating environment.

It can take an experienced engineer to balance the various trade-offs and achieve the best overall solution. Please message me if you are concerned about viewing angle in any current or future project.

IPS (in-plane switching) is a screen technology for liquid-crystal displays (LCDs). In IPS, a layer of liquid crystals is sandwiched between two glass surfaces. The liquid crystal molecules are aligned parallel to those surfaces in predetermined directions (in-plane). The molecules are reoriented by an applied electric field, whilst remaining essentially parallel to the surfaces to produce an image. It was designed to solve the strong viewing angle dependence and low-quality color reproduction of the twisted nematic field effect (TN) matrix LCDs prevalent in the late 1980s.

The TN method was the only viable technology for active matrix TFT LCDs in the late 1980s and early 1990s. Early panels showed grayscale inversion from up to down,Vertical Alignment (VA)—that could resolve these weaknesses and were applied to large computer monitor panels.

Shortly thereafter, Hitachi of Japan filed patents to improve this technology. A leader in this field was Katsumi Kondo, who worked at the Hitachi Research Center.thin-film transistor array as a matrix and to avoid undesirable stray fields in between pixels.Super IPS). NEC and Hitachi became early manufacturers of active-matrix addressed LCDs based on the IPS technology. This is a milestone for implementing large-screen LCDs having acceptable visual performance for flat-panel computer monitors and television screens. In 1996, Samsung developed the optical patterning technique that enables multi-domain LCD. Multi-domain and in-plane switching subsequently remain the dominant LCD designs through 2006.

In this case, both linear polarizing filters P and A have their axes of transmission in the same direction. To obtain the 90 degree twisted nematic structure of the LC layer between the two glass plates without an applied electric field (OFF state), the inner surfaces of the glass plates are treated to align the bordering LC molecules at a right angle. This molecular structure is practically the same as in TN LCDs. However, the arrangement of the electrodes e1 and e2 is different. Because they are in the same plane and on a single glass plate, they generate an electric field essentially parallel to this plate. The diagram is not to scale: the LC layer is only a few micrometers thick and so is very small compared with the distance between the electrodes.

Unlike TN LCDs, IPS panels do not lighten or show tailing when touched. This is important for touch-screen devices, such as smartphones and tablet computers.

Toward the end of 2010 Samsung Electronics introduced Super PLS (Plane-to-Line Switching) with the intent of providing an alternative to the popular IPS technology which is primarily manufactured by LG Display. It is an "IPS-type" panel technology, and is very similar in performance features, specs and characteristics to LG Display"s offering. Samsung adopted PLS panels instead of AMOLED panels, because in the past AMOLED panels had difficulties in realizing full HD resolution on mobile devices. PLS technology was Samsung"s wide-viewing angle LCD technology, similar to LG Display"s IPS technology.

In 2012 AU Optronics began investment in their own IPS-type technology, dubbed AHVA. This should not be confused with their long standing AMVA technology (which is a VA-type technology). Performance and specs remained very similar to LG Display"s IPS and Samsung"s PLS offerings. The first 144 Hz compatible IPS-type panels were produced in late 2014 (used first in early 2015) by AUO, beating Samsung and LG Display to providing high refresh rate IPS-type panels.

Cross, Jason (18 March 2012). "Digital Displays Explained". TechHive. PC World. p. 4. Archived from the original on 2 April 2015. Retrieved 19 March 2015.

"TFT Technology: Enhancing the viewing angle". Riverdi (TFT Module Manufacturer). Archived from the original on 23 April 2016. Retrieved 5 November 2016. However, [twisted nematic] suffers from the phenomenon called gray scale inversion. This means that the display has one viewing side in which the image colors suddenly change after exceeding the specified viewing angle. (see image Inversion Effect) External link in |quote= (help)

tech2 News Staff (19 May 2011). "LG Announces Super High Resolution AH-IPS Displays". Firstpost.com. Archived from the original on 11 December 2015. Retrieved 10 December 2015.

"Samsung PLS improves on IPS displays like iPad"s, costs less". electronista.com. Archived from the original on 27 October 2012. Retrieved 30 October 2012.

ER-TFT019-1 is a high-quality 1.9 inch IPS TFT display with a resolution of 170x320 pixels, which offers clear and sharp images with excellent color reproduction. The display utilizes In-Plane Switching (IPS) technology, which provides a full viewing angle, ensuring that the screen content is easily visible from any direction without any color distortion or fading.

The display is equipped with an ST7789 controller, which is a popular and reliable driver chip that supports both 8080 parallel and 4-wire SPI interfaces, making it easy to integrate with various microcontrollers and systems. The 8080 parallel interface provides fast data transfer rates, while the 4-wire SPI interface allows for easier wiring and lower pin count.

ER-TFT019-1 is also designed with low power consumption in mind, making it ideal for use in portable and battery-powered devices. Additionally, the display features a built-in touch panel (optional) that provides user input and interactivity with the device.

This compact 1.9 inch IPS TFT display is an excellent choice for various electronic devices, such as wearables, portable devices, and DIY electronics projects. Its small form factor, low power consumption, and wide viewing angle make it a versatile and reliable display solution. Overall, ER-TFT019-1 offers a combination of high quality, low power consumption, and ease of integration that makes it a great choice for a wide range of applications.