Optical sheet, surface light source and display device
First Claim
Patent Images
1. An optical sheet, comprising:
- a translucent substrate having first and second surfaces;
an optical element provided on the first surface of the translucent substrate, the optical element including a plurality of unit prisms or unit lenses arranged thereon; and
at least one light diffusion layer provided in at least one of the following locations;
between the first surface of the translucent substrate and the optical element; and
on the second surface of the translucent substrate,wherein the at least one light diffusion layer includes micro particles and gap parts which are formed around the micro particles, respectively, and each of the gap parts has an oval shape oriented in a uniaxial direction, andan image contrast value of the light diffusion layer having the gap parts is equal to or less than 15 at a slit pitch of 0.5 mm, the image contrast value being measured by a method standardized by JIS K 7374.
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Abstract
An optical sheet is structured to have a translucent substrate 12, an optical element 16 provided on one surface S1 of the translucent substrate 12, on which a plurality of unit prisms 14 or unit lenses are arranged, and a light diffusion layer provided between the one surface S1 and the optical element 16 and/or on another surface S2 of the translucent substrate 12, and at least one of the light diffusion layer 18 includes gap parts 22 as a light diffusion element. At this time, the gap parts 22 is preferably in an approximately oval shape oriented in a uniaxial direction in plan view.
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Citations
19 Claims
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1. An optical sheet, comprising:
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a translucent substrate having first and second surfaces; an optical element provided on the first surface of the translucent substrate, the optical element including a plurality of unit prisms or unit lenses arranged thereon; and at least one light diffusion layer provided in at least one of the following locations; between the first surface of the translucent substrate and the optical element; and on the second surface of the translucent substrate, wherein the at least one light diffusion layer includes micro particles and gap parts which are formed around the micro particles, respectively, and each of the gap parts has an oval shape oriented in a uniaxial direction, and an image contrast value of the light diffusion layer having the gap parts is equal to or less than 15 at a slit pitch of 0.5 mm, the image contrast value being measured by a method standardized by JIS K 7374. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 18, 19)
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2. An optical sheet, comprising:
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a translucent substrate in which micro particles and gap parts are formed near at least one of first and second surfaces of the translucent substrate, or within an area from the first surface to the second surface of the translucent substrate, the gap parts being formed around the micro particles, respectively, and each of the gap parts has an oval shape oriented in a uniaxial direction; and an optical element that is configured with a plurality of unit prisms or unit lenses provided on one of the first and second surfaces of the translucent substrate, wherein an image contrast value of the translucent substrate having the gap parts is equal to or less than 15 at a slit pitch of 0.5 mm, the image contrast value being measured by a method standardized by JIS K 7374.
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12. A surface light source device, comprising:
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a light guide body that includes a light incidence surface and a light discharge surface, that is formed of a translucent material, and that discharges light introduced from the light incidence surface; a light source that illuminates light to the light incidence surface and through the light guide body; and an optical sheet that transmits the light exiting from the light discharge surface, the optical sheet including; a translucent substrate having first and second surfaces, an optical element provided on at least one of the first and second surfaces of the translucent substrate, the optical element including a plurality of unit prisms or unit lenses arranged thereon, and at least one light diffusion layer provided in at least one of the following locations;
between the first surface of the translucent substrate and the optical element; and
on the second surface of the translucent substrate,wherein the at least one light diffusion layer includes micro particles and gap parts which are formed around the micro particles, respectively and each of the gap parts has an oval shape oriented in he uniaxial direction, and wherein an image contrast value of the at least one light fusion layer having the gap parts is equal to or less than 15 at a slit pitch of 0.5 mm, the image contrast value being measured by a method standardized by JIS K 7374. - View Dependent Claims (14, 15, 17)
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13. A surface light source device, comprising:
- an optical sheet that comprises;
a translucent substrate having first and second surfaces, an optical element provided on at least one of the first and second surfaces of the translucent substrate, the optical element including a plurality of unit prisms or unit lenses arranged thereon, and at least one light diffusion layer provided in at least one of the following locations;
between the first surface of the translucent substrate and the optical element; and
on the second surface of the translucent substrate, wherein the at least one light diffusion layer includes micro particles and gap parts which are formed around the micro particles, respectively and each of the gap parts has an oval shape oriented in the uniaxial direction;
a light source that illuminates light from a rear side of the optical sheet; and
a reflection body positioned on a side opposite from the optical sheet of the light source and reflecting the light from the light source to the optical sheet, wherein an image contrast value of the at least one light diffusion layer having the gap parts is equal to or less than 15 at a slit pitch of 0.5 mm, the image contrast value being measured by a method standardized by JIS K 7374.
- an optical sheet that comprises;
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16. A surface light source device, comprising:
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a light guide body that includes a light incidence surface and a light discharge surface, is formed of a translucent material, and discharges light introduced from the light incidence surface; a light source that illuminates light to the light incidence surface and through the light guide body; and an optical sheet that transmits the light exiting from the light discharge surface, the optical sheet including; a translucent substrate having first and second surfaces, including gap parts formed near the first surface of the translucent substrate or from the first surface to the second surface of the translucent substrate; and an optical element that is provided on the first surface of the translucent substrate, the optical element including a plurality of unit prisms or unit lenses arranged thereon, and at least one light diffusion layer provided in at least one of the following locations; between the first surface of the translucent substrate and the optical element; and
on the second surface of the translucent substrate,wherein the at least one light diffusion layer includes micro particles and, gap parts which are formed around the micro particles, respectively and each of the gap parts has an oval shape oriented in the uniaxial direction, and an image contrast value of the at least one light diffusion layer having the gap parts is equal to or less than 15 at a slit pitch of 0.5 mm, the image contrast value being cured by a method standardized by JIS K 7374.
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Specification