Thanks to the growth of LCD HD displays in recent years, DisplaySearch finds that demand for so-called "brightness improvement films" used in LCD backlights will grow by up to 30 percent over a year ago, to about 116 million units.
Brightness improvement films are sheets that are used in TFT LCD backlight units in order to improve luminance efficiency inside the backlight units (or to recycle luminance within a backlight system).
DisplaySearch said its projected sharp growth will be driven by expansion of LCD's share of HD sets sold, which it expects to grow by nearly 20 percent in the current calendar year. The researcher said by 2012 the market is expected to grow by "double digits annually"—representing what it said is a good business opportunity for more film makers to participate, and to improve LCD backlight technology.
The four major types of brightness improvement films include:
- • Normal Prism Sheet—enhances luminance by directing light from the light source.
- • Multi-Functional Prism Sheet—combines prism and diffuser functions by using beads, doping or surface micro-lens structures to direct light with higher efficiency than a normal prism sheet.
- • Micro-Lens Film—combines diffuser and prism functions in one film by using a micro-lens array structure. (Many LCD panel makers replace conventional prism sheets with micro-lens films.)
- • Reflective Polarizer (DBEF)—reflective polarizer or DBEF (dual brightness enhancement film) is a proprietary technology owned by 3M that reflects insufficiently polarized light back into the backlight unit, in effect, "recycling" the light.