View control film is made of louver layer as a view control function and high transparent film as a protection part. The louver layer consists of alternate layers of transparent layer and shading layer, being constructed like a blind.
Silicone rubber is used.
Silicone rubber is used in transparent/shading layer. The crystal temp. is around -40℃. It is elastic in room temp., superior in environmental resistance and optical characteristic. Also, flexibility can be added. See the following for the flexibility effect.
- Shock absorption can be expected, as the silicone rubber is placed on the surface of LCD.
- Touch panel works well even if VC-FILM is put on it.
Low refractive index (1.43) makes the layer thinned.
Flexibility of louver layer
Louver is flexible and well workable. It keeps the dimension of the louver layer stable. Therefore, it keeps stable view angle characteristics including flatness and max. transmittance angle, as a view control film.
The design rule of the louver layer
|Thickness of louver layer||Pitch of shading layer||View angle||Illustration|
Our design rule doesn't set up cut-off parameter. Transmittance value out of the view range is set 0. On the basis of VC-FILM standard spec (view angle; 60°90°120°), the value of louver thickness and shading layer is set like the one in a chart, you can get view angle you need.
Technology for high functionality
Adhesive layer is set on view control film. During the assembly process to LCD, air is released by lamination. Refractive index moves radically and reflection surface is reduced to make high brightness. Adhesive layer has two options. (a) higher brightness. (b) Higher adhesion. You can expect app.10%-up brightness by lamination (depends on conditions).
Optical isotropic type
Outline of optical isotropic type
Optical isotropic characteristic is required when view control film is used under polarized light. As the both sides of retardation-controlled polycarbonate are laminated to louver layer at both side of louver at 90°-rotated slow axis, the retardation of polycarbonate is canceled. It has low retardation as a optical isotropic type. The value is under 10nm, which is ignorable.
Privacy protection from 4 directions
Privacy protection from 3 directions
Privacy sometimes requires to be protected not only from the left and the right sides, but also from the upper and the down sides. In the case of protection from 4 directions, two louver sheets as above are intersected at 90°. While the protection from the upper side is kept, the shading part of the louver layer as a protector from the upper and down-side is leaned toward the front to keep privacy from the upper, the left and the right directions (refer to the following illustration).
The view angle of VC-FILM is controlled by the balance between louver thickness and louver pitch. Fine pitch makes the louver layer thinned without view angle change. Thinner polyester film is available as transparent plastic film. VC-FILM can be thinned up to 50-75% of the original one.
Color louver type
Silicone rubber can be colored. Black VC-FILM is changeable into other color. Some pigments for silicone rubber are available. It is also used for functional filament such as luminescent material.
Treatment of no-stick (Newton Ring)
When VC-FILM is built in an application and there's just small space between it and other part, uneven brightness or Newton Ring may occur. As a countermeasure against it, we mat the transparent plastic film. HAZE level can be controlled for your usage, you must confirm the effectiveness under operating environment. HAZE control effects interference problem.
You can choose the following, as surface finish of transparent film on VC-FILM.
- AG+hard coating
- AR+hard coating
- AR+AG+AS+hard coating
"Veil view" and "ray direction control" will be more needed for LCD in near future. We'll meet the market needs by improving the functionality of VC-FILM.