Kimoto Co, Ltd.

Hideharu Nagami

Yasumaro Toshima

Masashi Takai

An anti-Newton ring sheet includes an anti-Newton ring layer containing binder resin and particles, and formed on at least one surface of a transparent polymer film, wherein the particles are monodisperse spherical particles having a mean particle diameter of not less than 0.4 &#x3bc;m and not more than 2.0 &#x3bc;m and are contained in an amount of not less than 0.5 parts by weight and not more than 3 parts by weight based on 100 parts by weight of the binder resin. The anti-Newton ring sheet can prevent scratching of a contact surface even if it is brought into contact with a light guide plate or the like made of a softer material, without loss of the anti-Newton ring effect. The anti-Newton ring sheet can be utilized for an optical film having an anti-Newton ring effect by providing an optical function layer such as a light diffusing layer on the surface opposite the anti-Newton ring layer.

Anti-newton ring sheet

A light diffusive sheet of the present invention comprises a transparent polymer sheet provided with a light diffusion layeron one side and an uneven surfacehaving arithmetical mean deviation of 0.5 &#x3bc;m or less and mean spacing of 80 &#x3bc;m or narrower on the opposite side. Such an uneven surface can be made by forming a backcoat layerincluding a mixture of particles having particular mean diameters in a particular proportion to a binder resin on the transparent polymer sheet. An area light source elementof the present invention is produced by laminating a prism sheeton a light guide plateso that the prism surfaceof the prism sheetis opposed to the light-emitting surfaceof the light guide plateand laminating the light diffusive sheet on the prism sheetso that the uneven surface (backcoat layer) of the light diffusive sheet is opposed to the surface opposite of the prism surface. The light diffusive sheet of the present invention can prevent occurrence of a rainbow-like annular pattern without deteriorating the front luminance and view angle of the area light source even when combined with a downward-facing prism sheet.

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Mie-ken, Japan

Hideharu Nagami