IGZO and IPS are common terminologies that you will often see get thrown around by people talking about display technologies. One is a panel type that is used on LCDs while the other is a backplane technology that is used on LCD and OLED displays.
IGZO is an acronym for a thin-film transistor (TFT) semiconductor material that stands for Indium Gallium Zinc Oxide. This material can be used on LCD and OLED backplanes. IPS, on the other hand, stands for In-plane Switching and is a type of panel used on LCDs.
So, as you can see IGZO and IPS are two different things but are related in that they can be used on the same display.
IGZO can be used on IPS panels to greatly improve performance and as a replacement for the widely used hydrogenated amorphous silicon thin-film transistor (a-S:H TFT) material used on most LCDs.
So, how do all these terms and heavy jargon affect you as the consumer? To better answer that question we should look at each of these terms in more detail for a better understanding.
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What is an IPS panel?
As I mentioned above an IPS panel stands for an In-Plane Switching panel in full. It is used as an alternative for TN panels (Twisted Nematic) and VA panels (Vertical Alignment).
This is a panel that is used on LCD FPDs (flat-panel displays) from monitors, TVs, tablets, Nintendo switches, smartphones, and so on.
IPS panels are known for their broader color gamuts which are crucial for displaying rich and accurate colors and wide viewing angles. These are some of the features that make IPS panels better than TN and VA panels.
However, they have slower response times than TN panels which are not as color accurate and do not have wider viewing angles. IPS panels have wider viewing angles because they eliminate the drastic color shifting found on VA and TN panels.
Keep the slower response times in mind as this is something that IGZO backplane transistors greatly improve on IPS panels and other display technologies.
What is a display backplane?
A backplane is a display assembly that is responsible for driving a display. This is done with the help of thin-film transistors such as IGZO, A-Si, and LTPS which determine the refresh rate, power efficiency, and resolution of a display.
These TFTs (thin-film transistors) are made up of thousands of transistors that turn individual pixels on and off by determining how much charge goes into each pixel. This, therefore, affects the characteristics and quality of a said display.
But in this guide am only going to touch on a-Si and IGZO thin-film transistors since they are related to what we are talking about.
IGZO vs a-Si backplanes and why they matter
Hydrogenated amorphous silicon (a-Si:H) backplanes are accredited for the massive success that LCDs have had on the market and their ability to replace cathode ray tube displays.
A-Si TFT is an active matrix backplane technology that was developed to improve viewing angles, resolution, and pixel density.
However, a-Si backplanes have two major drawbacks, high power consumption, and a lack of great transparency.
Because amorphous silicon materials are not that transparent, they have to be etched to make them as thin as possible for more transparency which allows more light from the backlighting panel to pass through them.
This lack of transparency and the higher energy consumption is where IGZO TFT technology comes in.
IGZO stands for Indium Gallium Zinc Oxide and is a semiconductor material used on thin-film transistors. It was developed by a Japanese professor known as Hideo Hosono in collaboration with his team at JST in the early 2000s.
These backplanes are active-matrix backplanes that can greatly improve the performance of LCDs on all panels from IPS, TN, VA, and OLED panels.
This is because IGZO is transparent and can deliver faster response times, refresh rates, more pixel density, and better color accuracy. What’s more; IGZO TFTs use 80 to 90 percent less power than amorphous silicon TFTs while being 20 to 50 times more efficient.
All this is made possible by the fact that IGZO backplanes have incredible electron mobility and can retain charge on individual pixels for extended periods on a still image. The charge retention means that a display does not have to refresh each time it is displaying a still image.
Advantages of IGZO TFT on IPS panels
When implemented on IPS and OLED panels, IGZO will offer one major advantage and take is high power efficiency as these backplanes do not need as much power from the backlight on LCDs. This is because of the high electron mobility, charge retention (due to low current leakage), and transparency.
With a display with an IGZO TFT, you can keep the charge on your device for longer whether it is a Nintendo Switch, an iPad, or a laptop, and save on your energy cost when used on a TV or a monitor.
The second advantage pertains to PC gamers and gamers in general due to the faster response time. You do not have to sacrifice color accuracy for faster response times by using a TN panel (are also making major advances).
This is because the IGZO backplane significantly improves response times on IPS panels from several milliseconds to less than 5 milliseconds (up to 1ms), similar or faster to what you would find on a TN monitor.
Response time is not the only thing that IGZO makes fast on a display as it also increases the refresh rates which come in handy when it comes to playing competitive and high FPS games.
The third main advantage of IGZO to the average consumer is a higher pixel density on the display. Pixel density is measure in PPI or pixel per inch and the number of pixels available on one-inch square of the display.
The higher pixel density is accredited to the transparency of IGZO TFTs and high efficiency which means that the transistors can be etched and made even smaller for more pixels without loss in performance. With a higher PPI, the clarity and level of details are increased improving the overall experience.
There is also the improved sensitivity on touch-sensitive devices thanks to the reduced noise influence that IGZO semiconductors offer. This is why drawing or writing on an OLED iPad mini or pro with an IGZO backplane feels more lifelike and satisfactory.
The problem with IGZO implementation and what it means for a consumer
One of the main problems with IGZO TFTs is integration on displays.
The methods of depositing IGZO on backplanes are expensive and not that widely adopted which when coupled with the cost of Indium and Gallium which are rare earth minerals makes the implementation of IGZO an expensive endeavor.
What this translates to is a higher cost for consumers who are interested in displays that have adopted the technology.
This is why the technology only has a major foothold on smaller displays such as smartphones, iPads, and so on but the use of this material on larger displays is yet to be widely adopted.
Larger displays such as TVs and monitors that use IGZO backplanes are expensive but we can expect the cost to drop once more companies license the technology and the methods of implementation on TFTs continues to advance and improve.
IGZO is a backplane technology that can be implemented on different LCD panels such as VA, TN, and IPS. This technology can also be used on OLED devices and would greatly improve the already incredible display technology.
Meanwhile, IPS is a type of panel that can be combined with an a-Si, LTPS, or IGZO TFT which are transistors that control the pixels on a screen.