Why can Switchable PDLC film be used as projection screen?

2018-09-10
InnoGlass | Smart Privacy LC Glass and Film Factory > Q&A > Why can Switchable PDLC film be used as projection screen?

smart film for projection

Switchable PDLC film, Polymer Dispersed Liquid Crystal (PDLC) is a kind of liquid crystal which is mixed with prepolymer gel to form micron-sized liquid crystal droplets uniformly dispersed in the polymer network under certain conditions. The dielectric anisotropy of the molecule obtains materials with electro-optic response characteristics. It mainly works between the scattering state and the transparent state and has a certain gray level. Polymer dispersed liquid crystal (PDLC) membrane is a kind of membrane material with excellent comprehensive properties, which is obtained by combining liquid crystal with polymer.

Principle of switchable PDLC film optical switch

In the absence of applied voltage, regular electric field can not be formed between the films. The optical axis orientation of the liquid crystal particles is random and disordered. Its effective refractive index N0 does not match the refractive index NP of the polymer. The incident light is strongly scattered and the film is opaque or translucent.

When the external voltage is applied, the optical axis of the liquid crystal particles is perpendicular to the surface of the film, which is consistent with the electric field direction. The refractive index of the ordinary light of the particles matches the refractive index of the polymer basically, and there is no obvious interface between the particles and the polymer, so the incident light does not scatter and the film is transparent. Therefore, driven by an external electric field, PDLC has optical switching characteristics.

Projection imaging principle of switchable PDLC film

Because the liquid crystal polymer has the optical conductivity, so the liquid crystal layer because of the liquid crystal molecule good light conductivity, projection image brightness, loss is small, about 40%, so the projection image can be clearly presented, all when projected onto the liquid crystal film, in the case of power failure, white background, so that the film has a good formation. Like function, liquid crystal film imaging is the best with rear projection.

Advantages list:

  1. High definition ,projection clarity, can be compared with TFT-LCD;
  2. Switchable PDLC film can be cut according to the actual needs, and the use of self-adhesive mold can be pasted on the glass surface, simple installation;
  3. Switchable PDLC film can be used as a privacy glass without projection, and it can isolate UV and IR, safe and green.

So more and more customer want to use switchable PDLC film as projection screen for shopping window, meeting room, building advertisement wall and so on!

 

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