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AssigneeDai Nippon Printing Co., Ltd.
InventorsRika Ando, Haruo Ono, Hisanori Ishida, Michiko Takeuchi, Toshikazu Nishio, Nobu Masubuchi
Estimating the term…
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.
A lens array sheet, comprising:
Dependencies are inferred from the claim text.
Drawings are temporarily unavailable. Open the PDF at USPTO
No related US applications are recorded in the indexed filing history.
Provided by one optical element, or plurality thereof, placed on the light output side of the light guide: prismatic sheet or layer; Brightness…
Characterised by the manufacturing method: replication or moulding, e.g. hot embossing, UV-casting, injection moulding
Characterized by the distribution or form of lenses: inhomogeneous or irregular arrays, e.g. varying shape, size, height
Characterized by the distribution or form of lenses: arranged along a single direction only, e.g. lenticular sheets
Term ended 5 Sep 2015 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. Field of the Invention
The present invention relates to a lens array sheet that has a homogeneous lighting characteristic as a lighting means for use with a transmission type liquid crystal display device, a back light source for a transmission type display device for an advertisement board. In addition, the present invention relates to a surface light source and a transmission type display device with the lens array sheet.
2. Description of the Related Art
FIG. 1 is a perspective view showing a lens array sheet according to an embodiment of a first aspect and a second aspect of the present invention;
FIG. 2 is a perspective view showing the shape of a cluster member of the lens array sheet according to the embodiment of the first aspect and the second aspect of the present invention;
FIG. 3 is an enlarged perspective view for explaining cluster members formed on the lens array sheet;
First, with reference to FIGS. 1 to 6, a lens array sheet according to a first aspect of the present invention will be described.
FIG. 1 is a perspective view showing a lens array sheet according to the first aspect of the present invention. A lens array sheet 1 according to the first aspect of the present invention shown in FIG. 1 is composed of a transparent substrate sheet 31, a lens array 4, and a cluster 2. The lens array 4 is composed of a large number of triangular prisms as lens elements 41 that are adjacently and one-dimensionally arranged on a first surface of the transparent substrate sheet 31 so that the edge lines of the lens elements 41 are arranged in parallel. The cluster 2 is composed of a large number of cluster members 21 that are formed in a rectangular parallelepiped shape and randomly and two-dimensionally arranged on the entire second surface (rear surface) of the transparent substrate sheet 31. In FIG. 1, the cluster 2 is drawn on the second surface (front surface) for convenience of drawings.
The lens array sheet according to the first aspect of the present invention features the cluster formed on the opposite surface of the lens array. The cluster is composed of a large number of cluster members that are formed in a prism shape. The length of each side of each cluster member is in the range from the wave length of the light of the light source to 500 .mu.m. The cluster members are randomly and two-dimensionally disposed on the entire surface of the second surface of the lens array sheet.