[FPDI] Japanese Firm Develops 'Invisible Glass'

Oct 28, 2011
Satoshi Okubo, Nikkei Electronics
A normal glass substrate (left) and the new substrate (right). Because light is hardly reflected on the new substrate, it can hardly be seen.
A normal glass substrate (left) and the new substrate (right). Because light is hardly reflected on the new substrate, it can hardly be seen.
[Click to enlarge image]
A closeup shot of the normal glass substrate (left) and the new substrate (right).
A closeup shot of the normal glass substrate (left) and the new substrate (right).
[Click to enlarge image]

Nippon Electric Glass Co Ltd developed a glass substrate that it calls "invisible glass" and exhibited it at FPD International 2011.

The company reduced the reflection of light so that light can hardly be seen on the glass substrate. When I stood in front of the glass substrate, it was difficult to recognize the existence of the substrate. Many other visitors were gazing at the invisible glass with surprised looks on their faces.

Nippon Electric Glass reduced the the reflection of light by forming an anti-reflection film on each of the front and back sides of the glass substrate. In the case of a normal glass substrate, about 92% of incoming light passes through it, and the rest 8% of the light is reflected on it. On the other hand, about 99.5% of incoming light passes through the new glass substrate. So, only about 0.5% of the light is reflected on it.

Nippon Electric Glass claims that the luminous reflectance of the substrate is 0.1% or lower. For the two anti-reflection films, the company used a total of 30 or more layers. And the thickness of each layer is controlled in increments of nanometers.