Black is Clear and other Design Considerations for Transparent OLED Displays

Getting the most out of technology often requires learning some new techniques and ideas. When photography was first invented, people would need to stand still for minutes to capture a portrait instead of the hours it took for a painter. When moving pictures were new, actors had to learn how to emote for the camera without using any words or sounds. When color movies first came along, directors had to begin thinking about palettes and hues and saturation. The Planar® LookThru™ OLED transparent display brings the same type of challenges along with its exciting new possibilities.

Black is Clear

What makes a transparent display unique is, of course, its transparency. On the Planar LookThru OLED transparency is achieved by giving it black content while brightly colored, fully saturated content appears opaque. Unlike liquid crystal displays where black is achieved by turning on all the crystals so that they fully obscure the backlight, organic light emitting diode displays achieve black by turning all the OLED pixels off. On a traditional OLED screen that looks black, but on a transparent screen black is clear. 

Tip: Make sure you’re using true black and not a dark gray if you want full transparency.

Brightness is a an Illusion

If you look at the technical specifications for the Planar LookThru OLED transparent display, you might think that it’s not a very bright display, and it’s true that it doesn’t emit as much light as a traditional LCD with a backlight. But the transparency of the black colors on the screen emphasize the luminosity of the other colors making them appear much brighter to the eye. 

When you want to make something appear bright, use a broad color gamut. Like white text on a black background seems brighter than the same text in red or blue, using high-contrast colors against the transparent background will create the illusion of brightness.

Color is Power

Since each pixel on the Planar LookThru OLED transparent display emits its own light, the more pixels that are lit, the more power the display takes. If you think about each pixel as a light bulb that can be independently turned on or off, you’ll get an idea of how content is related to power consumption. If every pixel on the screen is lit up all the time the display will use much more power than if only a quarter of the pixels are lit up. By the same token, the longevity of the display is dependent on how long the pixels are active. So, based on the content used, the power use and life of the display can vary widely. 

Tip: Try to average having the screen transparent 75% of the time.

Transparency is Variable

What’s behind the display is as important as what’s on the display – otherwise it wouldn’t need to be transparent. But you can use different lighting effects to change the relative transparency of the display independently of the content being shown. 

Think about looking out the window on a dark night. If you have the lights on inside, you’ll just see your reflection in the glass, but if you turn off the lights inside you can see outside clearly. By adjusting the lighting both in front of the Planar LookThru OLED transparent display and behind it, you can emphasize different object or obscure them until you’re ready for them to be seen. All content is an exercise in moving people’s attention; a transparent display simply gives more places for that attention to be focused. 

Look Around – No Really

Unlike any other display, the Planar LookThru OLED transparent display has a nearly 360-degree viewing angle. People can see from the back just as well as from the front (though the content is reversed, like in a mirror). So if the display is installed in a place where people can look at it from both sides, the content should reflect that. Minimizing the use of text and focusing on compelling images will help people from every side to engage with the content.

Keep Experimenting

Just like when the camera was new, or film, or color movies, it was the ingenuity and creativity of the people who used the new technology that drove its adoption and innovation. You have the chance to not only embrace a completely new type of content, but to pioneer its use and help shape the future.


Watch Planar LookThru OLED transparent display video to see more of this new, exciting product.