Display technologies are one of the biggest drivers in advances in entertainment. From televisions and Home Theaters, to Virtual and Augmented reality applications – thinner displays, higher pixel densities, increased response times and improved color accuracy play a big part in how we experience these technologies.
As display technologies improve, we are seeing an exponential decline in the size of display components and as a result – exciting new applications on the horizon.
The current winner – OLED
Recent advancements in display technologies brought with it curved, flexible and foldable LED & OLED displays.
Organic light-emitting diode, also referred to as OLED or Organic LED is a LED layer of organic compound that emits light in response to an electric current. The benefits of this technology include an increase in power efficiency (meaning longer battery life in handheld devices), a slimmer profile, large viewing angles and vibrant colors paired with pure blacks.
The benefits of OLED:
- Superior viewing angles
- High brightness and contrast
- Fast response times
- Small size form factors
- Well suited for battery driven applications
OLED does bring with is some disadvantages, like color burn-in and the fragile nature of organic materials used.
Enter Micro-LED.
Micro-LED
Like OLED, Micro-LED is a self-emitting display constructed from Light Emitting Diodes producing their own light. The difference is that Micro-LED use inorganic materials, like Gallium Nitride (GaN). This means they do not need an encapsulation layer, allowing for even thinner panels.
Micro-LED components are incredibly small, with each measuring less than 100µm –thinner than a human hair!
While OLED is currently the display technology of choice, it does come with some issues:
- Color Burn-In is still a problem
- It has a shorter lifetime compared to other display technologies
- OLED panels are generally fragile, with the organic materials being susceptible to oxidation in vulnerable environments
Micro-LED shares the benefits of OLED, while also addressing the above issues. These benefits include:
- Improved brightness to power ratio, achieving the same level of luminance as an OLED with less power
- 180° viewing angles
- No fading and 100,000+ hours lifetime
- Higher resolutions in smaller form factors
- Extremely high response times, measured in nanoseconds
The first Micro-LED TV debut was Samsung’s “The Wall” – a frameless, modular screen that offers industry-leading resolution and an industry-first modular capability that allows end-users to expand their TVs as applications change.
Stretchable Displays
The latest innovation leading from the advances made through Micro-LED technology, is stretchable displays.
Prototypes of these displays have already been manufactured, with reports of displays with 130% stretchability, convex bending up to 40° and resolutions up to 120 PPI (Pixels per inch). The displays are not only foldable and rollable, but also capable of 3D freeform shaping – including pulling, twisting, convex and concave deformations.
A team at Stanford University announced the development of “a method to produce a high-brightness elastic light-emitting polymer, which functions like a filament in a lightbulb. The group’s resulting display is made entirely of stretchy polymers – synthetic plastic materials. Their device has a maximum brightness at least two times that of a cellphone and can be stretched up to twice its original length without tearing.
Beyond the cosmetic applications, this technology can be used to improve health and even save lives. For example, the Samsung Advanced Institute of Technology (SAIT) has been able to integrate a stretchable organic LED (OLED) display and a photoplethysmography (PPG) sensor in a single device to measure and display the user’s heart rate in real-time, thus creating the ‘stretchable electronic skin’ form factor.
So far, the various stretchable displays under development offer only low-resolution, basic image capabilities, but this will undoubtably change in the future.
One benefit of this technology is that it relies on existing semiconductor fabrication processes – bringing the prospect of commercially available stretchable displays tantalizingly close.
Virtual Reality
The advances made through Micro-LED – most notably pixel density increases – are hugely beneficial for Virtual Reality applications. In fact, the biggest separator between professional VR headsets and consumer headsets is pixel density.
Higher pixel densities allow you to see finer details, like seeing the fabric details more clearly on furniture or spotting a target at a greater distance. Achieving ‘Retinal resolution’ – 60 pixels/degree, or 60px x 60px in a 1°x1° area – is the ultimate goal for headsets, where even people with perfect vision can’t discern any additional detail.
Micro-LED brings us one step closer to this vision.
The Future
The future of screen technology is almost certainly Micro-LEDs. As with every new technology, there is a learning curve for manufacturers and manufacturing processes need to catch up to the theoretical potential of the technology.
Once manufacturing potential catches up to the rendering benefits of Micro-LEDs, the leap from OLED to Micro-LED could be rapid – leaving OLEDs behind as a single-generation technology that served as an interesting bridge to a new standard for screens from smartphones to televisions.
