Panasonic has created a transparent screen that could use the glass window as a high-resolution signage and provides a clear view of products and exhibits behind the glass when not in use as a screen.

 
Panasonic transparent screen lead1 (cr) Figure 1: Image shows the clear glass window with real and projected displays in transparent and screen modes, respectively.  

Panasonic has developed the XC-CSG01G–a glass comprised of a high-contrast light-control film placed in between two sheets of glass, which when voltage is applied changes from the screen mode to the transparent mode, as well as the XC-CSC01G-A1–a control box. Images are projected (from the rear) onto the glass during the screen mode. The control box can reproduce high-resolution images on the glass to introduce information about new products or about various campaigns during the sale season, helping transform the show window into an even more captivating environment. Moreover, multiple screens may be combined to create one large screen.

 
Panasonic transparent screen fig2 (cr) Figure 2: An illustration of a high-contrast light-control film in screen mode.  

Traditionally, images have been projected onto cloudy white, electric switchable glass, but this type of glass was incapable of displaying high contrast images due to image degradation caused by external light.

Controlling projection operation

Panasonic has combined glass with a high-contrast light-control film, which is comprised of a transparent-cloudy white switching layer containing special polymers and capsules and a hue control layer. The hue control layer will absorb a great deal of external light in screen mode, thereby reducing image degradation and bringing to life images on par with digital signage, even in brightly lit environments.

 
Panasonic transparent screen fig3 (cr) Figure 3: High-contrast light-control film in screen mode.  

Realising images by absorbing external light, the XC-CSC01G-A1 then reproduces high contrast images onto a transparent XC-CSG01G glass. Panasonic’s XC-CSC01G-A1 can optimise image quality according to the installation environment, combine and project several screens and control the displays as a single large screen system. The control box will switch between transparent and screen modes, control the projector and turn on/off the lighting in the exhibition space behind the glass.

Visuals solution

When Panasonic’s XC-CSG01G glass is in transparent mode, voltage is applied to the transparent/cloudy white switching layer which will give regularity to the arrangement of the light crystal molecules inside, thereby enabling the light to directly pass through. Moreover, by applying the maximum voltage to the hue control layer, the permeability of the high-contrast light-control film will be improved.

 
Panasonic transparent screen fig4 (cr) Figure 4: Image comparison between with and without the hue control layer.  

With the optional anti-reflective (AR) film on the surface of the glass that reduces unwanted glare, Panasonic has realised a permeability of approximately 68%. This enables the glass to serve as a shop window, giving a clear view of products and exhibits behind the glass.

By adjusting the hue control layer's permeability depending on the level of lighting in the installation environment, the screen can maintain the same level of high contrast in environments of varying brightness. In brightly-lit spaces, it can reproduce images with rich blacks, and in dark environments, it can reproduce high-contrast images even with a compact projector.

 
Panasonic transparent screen fig5 (cr) Figure 5: An illustration of the system layout of Panasonic XC-CSG01G glass and XC-CSC01G-A1 control box.