Dai Nippon Printing Co., Ltd.

Dainippon Ink and Chemicals, Incorporated

Michiko Takeuchi

Toshikazu Nishio

Nobu Masubuchi

Hisanori Ishida

Hiroyuki Amemiya

Haruo Ono

Rika Ando

Hiroshi Kojima

Hidenobu Ishikawa

Yoshiyuki Yamashita

Taiji Ishii

Kazuko Etou

Eiji Ichinose

Youichi Abe

Flat light source using light-diffusing sheet with projections thereon

A lens array sheet according to the present invention, comprising a transparent substrate, a lens array having lens elements that are one-dimensionally or two-dimensionally formed on the front surface of the transparent substrate, and a cluster having a large number of cluster members randomly formed in a prism shape on the rear surface of the transparent substrate, each of the length, the width, and the height of each of the cluster members being in the range from the wave length of source light to 500 .mu.m. Thus, a lens array sheet that effectively uses light energy of the light source, maintains the light condensing effect, prevents the luminance from deteriorating, homogeneously distributes the luminance on the light emitting surface, prevents equal-thickness interference fringes and wasteful light dispersion to out of the angular range of visual angle can be provided. In addition, a surface light source having the lens array sheet is provided. Moreover, a bright transmission type display device having the surface light source is provided.

Lens array sheet, surface light source, and transmission type display

Lens array sheet surface light source, and transmission type display

An ionizing radiation-curable resin composition which provides a cured product having no yield point in the stress-strain diagram in tension is disclosed. An optical article prepared from the ionizing radiation-curable resin composition and a surface light source using the optical article are also disclosed. The present invention provides an excellent ionizing radiation-curable resin composition, an excellent optical article comprising a cured product of the resin composition, and an excellent surface light source using the optical article, which have high surface hardness and a high refractive index and are free from deformation, permanent sets, and reduction in weather resistance after curing.

Ionizing radiation-curable resin composition for optical article,

A film lens comprises a light transmitting base having one side and an opposite side, a plurality of concave or convex unit lenses formed on the one side of the light transmitting base, and a plurality of projections formed on the opposite side of the light transmitting base and having a profile height not smaller than the wavelength of a source light and not greater than 100 .mu.m. In this arrangement, when the film lens is placed on a smooth surface of a light guide plate of a surface light source of the edge-light type, the projections on the reverse side of the light transmitting base can secure a gap with a width not smaller than the wavelength of the source light between the film lens and the light guide plate. Thus, the source light can be uniformly distributed without hindrance throughout the light guide plate as it is totally reflected by the surface of the guide plate. In the surface light source using the film lens, moreover, the lens can provide a uniform luminance in a desired angular range, and a uniform luminance distribution can be obtained for the whole surface without concentration in the vicinity of the light source.

Film lens and a surface light source using the same

A lenticular lens has a light transmitting substrate and a plurality of lens elements formed on the light transmitting substrate. The lens elements are defined in such a way that ridges thereof are aligned in parallel with each other, wherein 30.degree..ltoreq..theta..sub.10% .ltoreq.100.degree. and R.ltoreq.20%, where .theta..sub.10% is a diffusing angle range with respect to normal of the one surface in the case that when light is entered from the opposite surface and transmitted from the one surface, the intensity of the light transmitted is equal to or more than 10% of the intensity of the light transmitted in a peak direction of a main lobe; and R is the ratio of side lobes to main lobe. The intensity of side lobes which causes light loss and light stray can be remarkably reduced. Light can be equally and isotropically focused on in a predetermined diffusing angle range.

Renticular lens, surface light source, and liquid crystal display

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Tokyo-to, Japan

Michiko Takeuchi