Gunze Limited

Other

Sumitomo Chemical Company, Limited

Yukio Murakami

Shunsuke Hirano

Keiichi Minakuchi

A touch panel is constructed of a top sheet member having a resistive membrane on its inner surface and a base sheet member having a resistive membrane on its inner surface, the top and base sheet members facing each other with dot spacers being located in between. The top sheet member is formed by laminating a PET film, a polarizing film, a &frac14;&lgr; retardation film, and a light isotropic film in this order from its outer surface. The PET film has a thermal expansion coefficient lower than the other films underneath, such as the polarizing film. Accordingly, the PET film serves to keep the other films of the top sheet member from bulging outward when the temperature rises.

Glare-resistant touch panel

A touch panel is constructed of a top sheet member having a resistive membrane on its inner surface and a base sheet member having a resistive membrane on its inner surface, the top and base sheet members facing each other with dot spacers being located in between. The top sheet member is formed by laminating a bulge-resistant film, a polarizing plate, a quarter wavelength plate, and a light isotropic film in this order from above. The base sheet member is constructed of a glass sheet and a reinforcement film whose thermal linear expansion coefficient is almost the same as the thermal linear expansion coefficient of the polarizing plate or the quarter wavelength plate included in the top sheet member, the reinforcement film being adhered to the lower surface of the glass sheet.

Touch panel with high operability in low temperature environments

A touch panel is constructed of a top sheet member having a resistive membrane on its inner surface and a base sheet member having a resistive membrane on its inner surface, the top and base sheet members facing each other with dot spacers being located in between. The top sheet member is formed by laminating a bulge-resistant film, a polarizing plate, a quarter wavelength plate, and a light isotropic film in this order from above. A PET film which is not heat-treated so as to have a higher thermal contraction rate than the other members of the top sheet member underneath such as the polarizing plate, is used as the bulge-resistant film. Since the bulge-resistant film contracts more than the polarizing plate under a high ambient temperature, after the ambient temperature returns to normal, the bulge-resistant film does not become slack against the polarizing plate. Accordingly, the top sheet member can be kept from bulging outward.

Growing community of inventors

Kameoka, Japan

Yukio Murakami