In early 2019, LG Display started producing 55” transparent OLED TV panels, and these are slowly entering the market - in commercial displays, transportation displays, and perhaps even the consumer market - with Xiaomi’s first “consumer” transparent OLED TV (although at over $7,000 for a 55” display, it is not really priced at consumer level - and its usability is also not clear).
An OLED display is an emissive display, and some of our readers asked us - how is it possible for a transparent OLED TV to show a black color? Is the image above, released by Xiaomi, a fake?
In fact each transparent OLED display pixel can either be “off” or it can emit light - which means that any image you wish to show on such a display will have to be brighter than the background behind the screen when it is off.
It is also important to note that the OLED display is not entirely transparent. LG’s transparent OLED TV panels offer a transparency of 38% (which means that 62% of the light that come from behind the display is blocked). OLED developers are looking to increase the fill factor of the OLED display in order to increase the transmittance - and are also looking for other technologies (for example highly conductive and highly transparent electrode materials).
Interestingly, a transparent LCD can only block light, which means that such a display will only be able to show images that are darker than the background. Transparent LCD implementations usually include a back lighting solution in addition to the LCD panel. Perhaps in the future it will be possible to combine a transparent LCD with a transparent OLED to enable displays that can both emit light and block it - although this will lower the transmittance of the panel and of course increase the complexity and production costs.
LG Display is leading the large-area transparent OLED market - and other display makers are developing smaller transparent AMOLEDs, and some PMOLED makers are producing simple transparent displays. To learn more about the current status of this interesting market, and what the future holds, consult our Transparent OLED Market Report.