The 2017 prize was awarded for the invention of an innovative method for manufacturing polarizing film, an indispensable component for displaying images on liquid crystal displays and organic electroluminescent displays. The invention was highly praised for significantly contributing to the development of the display industry.
By suppressing the contractile force to less than half of its conventional value, the ultrathin polarizing film produced by this method has a greatly improved potential for reducing panel warping and optical distortion, both of which can lead to deterioration of display image quality. Polarizing film has been actively adopted in smartphones, tablet PCs, TVs, etc., which continue to become thinner. They can be expected to be used in flexible display applications, which is said to be the next generation of display technology.

Conventional polarizing films are manufactured by heating and stretching an iodine-dyed polyvinyl alcohol film in a boric acid solution until it reaches five or six times its original size. However, polarizing film manufactured with this method can easily shrink, and the effort to improve this defect has powered Nitto’s drive for technological innovation.
One method of suppressing shrinkage is ultra-thinning of the polarizing film, a technique that has attracted attention due to the recent trend toward thinner displays. However, thin polarizing films made using conventional manufacturing methods can break in the middle of production or lead to insufficient optical properties, resulting in increased demand for a technology that can address these problems at an even higher level.
It was with this in mind that Nitto invented the industry’s first process for stretching the polarizing film in two stages, under different conditions, by using a polyvinyl alcohol resin layer laminated on a thermoplastic resin substrate.
As a result, Nitto succeeded in producing a polarizing film with a thickness of approximately 5 μm — the thinnest polarizing film in the industry, capable of exhibiting excellent optical characteristics. By keeping the contractile force to less than half its conventional value, almost all optical distortion was eliminated and panel warping was significantly decreased. This manufacturing method can save resources compared to the conventional method by using smaller amounts of rare materials such as iodine and boric acid.
Ultra thin polarizing film manufactured by this method was awarded the Display Component of the Year Award last year by the Society for Information Display, the most prestigious organization in the display industry, as a product that greatly impacted the global display industry. The innovation is currently used in many flat screen TVs, smartphones and other products.

2017 National Commendation for Invention, Prime Minister’s Prize

Invention of manufacturing method for ultra-thin polarizing film (Japanese Patent No. 4691205)