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Transparent Display Technology
The technology for making a transparent display is not secret. Basically, TFT electrons and TFT pixels are transparent. However, the color filter is not transparent because the RGB color pixels and black matrix are arrayed on the color filter sheet. The backlight unit is also not transparent because of the many optical films (such as brightness enhancement films, prism sheet, diffuser, and reflectors) and the LED light sources. The trick to making a transparent display is basically to remove the backlight unit and transform the color filter structure.
A transparent display is similar to an LCD module without a backlight assembly. The RGB color pixels and the black matrix array in the color filter are reduced to the minimum size for transparency. Therefore, the resolution and color gamut cannot be high. In many cases, panel makers remove the color filter, making the transparent display monochrome. However, the emphasis is on transparency, so sacrificing resolution or color saturation is not a problem. In other words, the transparent display can be considered a value-added open cell panel with a frame bezel because panel makers don’t need to assemble the backlight unit.
TFT LCD makers have been developing transparent displays since pioneers like Samsung and LG Display started making them, as the following table shows:

Table 1-  Panel Makers’ Transparent Display Products

Panel Maker	Size	Resolution	Color Gamut
AUO	65”	FHD (1920 × 1080)	72%
Innolux Corp	55”	FHD (1920 × 1080)	72%
LG Display	26”	HD (1366 × 768)	68%
	32”	FHD (1920 × 1080)	68%
	37”	FHD (1920 × 1080)	68%
	42”	FHD (1920 × 1080)	72%
	47”	FHD (1920 × 1080)	72%
Samsung	22”	WSXGA (1680 × 1050)	5%
	46”	HD (1366 × 768)	72%
	55”	FHD (1920