Technology is always changing. As we lead increasingly busy lives, where digital information is everywhere, technology of all shapes and sizes is getting smaller. This is true on both a macro and micro scale: while our portable devices have decreased in size, so too has the technology that powers them. Most components have also grown even more powerful as they’ve grown smaller.  

This rise of small, powerful components has also led to significant developments in display technology. The most recent of which, AMOLED, is now the main competitor for the most common display used in quality portable electronics – the TFT–LCD IPS (In-Plane Switching) display. As more factories in the Far East begin to produce AMOLED technology, it seems likely we will enter a battle of TFT IPS versus AMOLED, or LCD vs LED. Where a large percentage of a product’s cost is the display technology it uses, which provides best value for money when you’re designing a new product?

TFT IPS displays improved on previous TFT LCD technology, developed to overcome limitations and improve contrast, viewing angles, sunlight readability and response times. Viewing angles were originally very limited – so in-plane switching panels were introduced to improve them.

Modern TFT screens can have custom backlights turned up to whatever brightness that their power limit allows, which means they have no maximum brightness limitation. TFT IPS panels also have the option for OCA bonding, which uses a special adhesive to bond a touchscreen or glass coverlens to the TFT. This improves sunlight readability by preventing light from bouncing around between the layers of the display, and also improves durability without adding excess bulk; some TFT IPS displays now only measure around 2 mm thick. 

AMOLED technology is an upgrade to older OLED technology. It uses organic compounds that emit light when exposed to electricity. This means no backlight, which in turn means less power consumption and a reduction in size. AMOLED screens tend to be thinner than TFT equivalents, often produced to be as thin as 1 mm. AMOLED technology also offers greater viewing angles thanks to deeper blacks. Colours tend to be greater, but visibility in daylight is lower than IPS displays. 

As manufacturers increasingly focus on smaller devices, such as portable smartphones and wearable technology, the thinness and high colour resolution of AMOLED screens have grown desirable. However, producing AMOLED displays is far more costly as fewer factories offer the technology at a consistent quality and minimum order quantities are high; what capacity there is is often taken up the mobile phone market Full HD TFT IPS displays have the advantage of being offered in industry standard sizes and at a far lower cost, as well as offering superior sunlight visibility. 

The competition between displays has benefitted both technologies as it has resulted in improvements in both. For example, Super AMOLED, a marketing brand by Samsung, involves the integration of a touchscreen layer inside the screen, rather than overlaid on it.  The backlight in TFT technology means they can never truly replicate the deep blacks in AMOLED, but improvements have been made in resolution to the point where manufacturers like Apple have been happy to use LCD screens in their smartphones, even as they compete with Samsung’s Super AMOLED. 

What does this mean for OEMs?

Aside from smartphones, many technologies utilise displays to offer direct interaction with customers. To decide whether TFT LCD will survive the rise of AMOLED technology, we must first recap the advantages of LCD. The backlit quality means that whites are bright and contrast is good, but this will wear down a battery faster than AMOLED. Additionally, cost is a significant factor for LCD screens. They are cheaper, more freely available and are offered in industry standard sizes so can be ordered for new products without difficulty. 

It seems hard to deny that AMOLED will someday become the standard for mobile phones, which demand great colour performance and are reliant on battery life. Where size is an issue, AMOLED will also grow to dominance thanks to its superior thinness. But for all other technologies, particularly in industrial applications, TFT-LCD offers bright, affordable display technology that is continually improving as the challenge from AMOLED rises.

 

Clive Dickinson is our business manager for Optoelectronics.

Follow Clive on LinkedIn