Differences between OLED displays on TVs and smartphones

OLED, short for Organic Light Emitting Diodes, is temporarily translated into Vietnamese as organic light-emitting diodes, being the best display technology in the present.

OLEDs possess a deeper black color, providing much superior images than traditional LCDs, and it does not require backlighting as on a traditional LCD screen, so it has a slimmer design. Because of these advantages of OLED, they can be compatible with both small and large screens.

OLED possesses deeper black color, providing superior image.

Many current flagship smartphones have used this OLED display technology . Samsung is a supplier of small size OLED displays for phones. We can easily see OLED not only on Samsung Galaxy but also on Apple iPhone X, Google Pixel 2 and even OnePlus 5T.

CNET also found that good performance TVs use OLED technology. LG Display is currently the only company to offer large-size OLED displays for TVs. This technology is currently applied to TVs from LG, Sony, Panasonic and Phillips.

LG also produces OLED displays for phones, especially the Pixel 2 XL, but the phone is having burn-in problems and the image quality is quite bad. This does not happen on Samsung OLED display phones, including iPhone X. On TV, LG does very well and is greatly praised, while Samsung has no longer sold OLED TVs. since 2013, they switched to QLED - a technology that is still an improvement from LCD.

So what is the difference between OLED on phones and TVs?

AMOLED and POLED

Not every OLED has an AMOLED and vice versa.

Both Samsung and LG talk about AMOLED and P-OLED. Both are different parts of OLED.

"AM" in "AMOLED" stands for "Active Matrix". It describes how each pixel is controlled individually. OLEDs with passive matrices will be more suitable for health monitors, but if you want to watch videos, you need an active matrix. So obviously, every OLED on TV or phone is an active matrix. Samsung named "AMOLED" for its OLED which is quite redundant. It is like calling "AMLCD" for LCD monitors, because all of them are active matrices.

The "P" in LG's "P-OLED" symbolizes "Plastic" (plastic), as opposed to glass. This name refers to the material of the OLED screen (surface), not the front part that you touch. They are separated and often use Gorilla Glass. The plastic is lighter and works better for phones, and allows for easier bending of the screen - something that both Samsung and LG have been using.

The bottom line, not every OLED has AMOLED or vice versa, but at the moment, almost all OLED displays have both. Alternatively, Samsung and LG can call OLED screens on phones, OLED, POLED, AMOLED, or even PAMOLED.

Subpixel RGB and WRGB: different, but not really better

Every screen is made up of tiny, single image elements, called pixels. Every pixel is composed of subpixel, usually each subpixel will have main colors like red, green and blue.

Each subpixel starts with "sandwich" (roughly translating) the OLED RGB (1), producing white light (2).Color filters (3) specify the color for the subpixel, creating the red, green, and blue colors you see (4).Subpixel output without a color filter, allowing through white light, will aid in brightness and color mixing.

This is the biggest difference between different OLED types.

Samsung's OLED TVs and phones use OLED red, green and blue OLEDs to create subpixels. LG's OLED phones and TVs are not. Instead, they mix the RGB color system to create white, and use this color filter to create red, green, blue and white.

Or to put it another way, every subpixel in LG's OLED is "white", then the upper color filter will determine which part of white you will see. In the first few years, LG's OLED screen used blue / yellow to mix. According to LG, they currently use RGB.

It seems that this complexity is not necessary. After all, if you use red, green, blue OLEDs, why not make red, green, blue and subpixels subtract this ineffective color filter? Based on the aforementioned and said OLED experts, the mixer allows it to minimize the aging blue effect on OLED materials faster than other colors.

Because every subpixel is similar, the entire panel has the same lifetime. These panels will be dimmer after use, but will not change color. LG has claimed that its OLED TVs have a life similar to LCD panels.

Compare OLED RGB and WRGB.

The production process is also simpler and therefore cheaper. In the size of the TV, this is quite important, since LG made the OLED panel become bigger and put into practice, no manufacturer dared to jump in. With phone size, it doesn't seem to have a lot of problems, as Samsung did.

Large and small pixels

As you know, the pixels on a phone are much smaller than on a TV. The real reason is not the complexity in production, because both are quite complex, but to create light is like.

OLED is a luminous technology, it will create its own light. And LCD is transmissive (it is a light transmission). The main function of liquid crystals is to block light, creating gray levels to create images. Removable backlight sets, usually including LEDs, will produce light.

OLED is a luminous technology, it will create its own light.

Because the pixels on the OLED light themselves. The smaller they are, the less light is supplied. Manufacturers can control them. They can increase their energy to make them brighter, but this will create a variety of other problems, such as battery life, heat generation, image storage and many problems with the overall life expectancy of the device.

To do this, OLED on the phone uses "PenTile" or diamond arrangement. This means that, instead of simply arranging red, green, and blue subpixels, they use less red and blue subpixels than green. We can understand that with a phone with a resolution of 2436x1125 there will be 2436x1125 (equal to 2,740,500) green subpixel, but only 1.370.250 red and blue subpixel. Red and blue subpixels are basically "shared" with green nearby. The bottom arrangement, used on the screen on the iPhone X, is manufactured by Samsung, which is a wing to do so, but can still be arranged.

A close-up of the diamond subpixel arrangement on OLEDs is manufactured by Samsung for iPhone X, or another name is Raymond Sonara / DisplayMate.Pay attention to the green, they are the majority, but the smallest, while the blue is less than the largest.

TVs rarely use this method. The latest Plasma TV uses this, because it can see larger pixels. It works well with small screens and high resolution, so your eyes can't recognize it and are much more efficient in production.

Future

OLED is the best technology in the present and will definitely be used in the near future, however, it's not perfect. Image retention, longevity, brightness, wide color range, efficiency and cost - all can improve. All of this has actually improved over the past decade, so it is quite difficult for them to get better the next time, because they are almost reaching their limit.

What would be interesting if Samsung, or other manufacturers, could participate in the OLED TV market? LG, with their WRGB design, seems to have found a way to reduce the cost of OLED effectively. As for the phone, obviously, we see that there are many other manufacturers who have played. Because really, no manufacturer wants to go back to using LCD on their flagship smartphones.

Once you're enjoying OLED image quality, it's hard to get back to the old LCD technology.