
For color displays the "twisted nematic"(TN) liquid crystals are most common. TN technology has been widely used in the industrial equipment. However, the disadvantages of TN-LCD type are narrow viewing angles and gray scale inversion. Fortunately, we have different ways overcoming gray scale inversion, such as Voltage Adjustment, Contrast Adjusting, Changing LCD Design, Using Better Polarizer and Changing Display Mode.
Gray Scale Inversion Issue
Gray bars are from gray level G0 (black) to G255 (white). Theoretically, the higher gray level is, the higher brightness is. However, you can see low gray level is brighter than high gray level at some specific angles and that is called gray scale inversion. Therefore, when you look at the LCD from a large angle, you can't see the original color, and even just white or black color can be seen.
Types of Panels: TN vs. IPS vs. VA
When the electric field interacts with the liquid crystal molecules, it will align in a variety of ways and permit light to pass through from the backlight of the device to the surface. The illustration below shows the principle of different LCD panels ↓
Wide Viewing Angle Technologies for TFT LCD
In view of the increasing requirements for TFT LCD panel with wider viewing angle. To meet customer’s needs, EVERVISION provides many different types of technology including, for example, MVA technology (Multi-domain Vertical Alignment), IPS technology (In-Plane Switching) and AAS technology (Azimuthal Anchoring Switch).
☛ Product List of Wide Viewing Angle TFT LCD Modules.pdf
IPS (In-Plane Switching) TFT LCD
When it comes to color performance and wide viewing angles, IPS panels are really great. It has 178/178 viewing angle ratings. The reason why IPS displays have better clarity of color than traditional TFT displays is its arrangement of electrodes and orientation layers.
IPS (In-Plane Switching) technology gives both horizontally and vertically wider viewing angle while maintaining consistent image quality and colors from all viewing positions. We provide a wide range of sizes from 3.5", 4.3", 7" to 10.3 inch for TFT LCD Module. Also, touch screen is available depending on client's application.
✦ HDMI Interface IPS TFT Display Modules
This TFT Display Series is designed with a control board with HDMI signal interface output. It allows developers to quickly add a TFT LCD display to their designs using a standard HDMI cable. Also. it features with IPS technology and USB touch.
● 7.0" HDMI Interface IPS LCM:VGG804833-L(WV)
● 10.4" HDMI Interface IPS LCM:VGG107620-C(SR)
● 12.1" HDMI Interface IPS LCM:VGG128020-C(WV)
MVA (Multi-domain Vertical Alignment) TFT LCD
MVA technology improves viewing angles above 160 degrees and has better contrast ratios. However, the one of disadvantages of MVA panel is slightly worse response times than TN or IPS. In recent developments of the MVA TFT LCD, contrast ratio, brightness, and response times have all improved in quality.
TN Film (O-Film)
In addition to wide viewing angle TFT modules, EVERVISION offers a full series of TFT LCD module with optional relative Wide View Film (O-Film). This O-film is affixed to polarizer, so we uphold our attachment process without purchasing new machine, adjusting production processes and adding jigs. Comparing to MVA technology or IPS technology, O-film has higher price competitive strengths.
TN vs. O-Film vs. VA vs. IPS
Feature |
TN |
TN Film (O-Film) |
VA |
IPS |
Viewing Angle |
TN display suffers from its limited viewing angles, particularly on the vertical axis. |
It features with a special film to widen the TN-LCD viewing angle. However, it can only improve viewing angle slightly. |
VA panel has better viewing angles and it is between the quality of TN and IPS panels. |
★★★ |
Contrast |
TN panels tend to have the lowest contrast ratios and inferior image quality. |
Same as TN-LCD Type |
VA Panel gives deeper blacks and higher contrast ratios. |
★★★ |
Response Time |
★★★ |
★★★ |
VA has slower response times than TN and IPS panels. |
IPS Panels are not known for their low response time. |
Cost |
$ |
$ |
$$$ |
$$$$ |
Best For |
This LCD type is used for simple electrical faster control panel such as HMI and POS. |
It is well suited for industrial application requiring a wider viewing angle. |
If your application requires wide viewing angles, VA panel is probably the alternative to cheaper TN-LCD as the technology. |
Suitable for many applications requiring a high-visibility display image or high resolution needs like patient monitor. |