LIGHT GUIDE PLATE, LIGHT GUIDE PLATE ASSEMBLY, AND PLANAR LIGHTING DEVICE AND LIQUID CRYSTAL DISPLAY DEVICE USING THESE
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Accused Products
Abstract
A light guide plate includes a light exit plane and a light entrance end, is formed into a shape having a thickness in a direction orthogonal to the light exit plane, the thickness being gradually larger as being farther-from the light entrance end, and contains scattering particles dispersed therein, and a light guide plate assembly includes the light guide plate and a prism sheet which includes a plurality of prisms arrayed in parallel with each other, and is arranged so that vertex angles of the prisms face the light exit plane. The scattering particles scatter light entering from the light entrance end and propagating in the light guide plate, which satisfy Expressions (1) and (2) below, and vertex angles of the prisms of the prism satisfy Expression (3) and (4) below.
1.1≦ΦNPLGKC≦8.2 (1)
0.005≦KC≦0.1 (2)
55°≦θ≦80° (3)
0°≦θ1≦15° and 30°≦θ2≦45° (4)
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Citations
47 Claims
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1-23. -23. (canceled)
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24. A light guide plate assembly, comprising:
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a light guide plate which includes a light exit plane for emitting a planar light and a light entrance end disposed in one end of the light exit plane and substantially orthogonal to the light exit plane, is formed into a shape having a thickness in a direction orthogonal to the light exit plane, the thickness being gradually larger as being farther from the light entrance end, and contains scattering particles dispersed therein; and a prism sheet which includes a plurality of prisms arrayed in parallel with each other, and is arranged so that vertex angles of the plurality of prisms face the light exit plane of the light guide plate, wherein; the scattering particles scatter light entering from the light entrance end and propagating in the light guide plate, which satisfy Expressions (1) and (2) below; when lengths of two straight lines sandwiching each of the vertex angles of the plurality of prisms of the prism sheet are equal to each other, an angle formed between the two straight lines of the equal lengths satisfies Expression (3) below; and when the lengths of the two straight lines sandwiching the each of the vertex angles of the plurality of prisms are different from each other, an angle formed between the straight lines of the different lengths satisfies Expression (4) below,
1.1≦
Φ
NpLGKC≦
8.2
(1)
0.005≦
Kc≦
0.1
(2)
55°
≦
θ
≦
80°
(3)
0°
≦
θ
1≦
15° and
30°
≦
θ
2≦
45°
(4)in Expressions (1) and (2), Φ
represents a scattering cross section [m2] of the scattering particles, Np represents a density [pieces/m2] of the scattering particles, LG[m] represents a length extending from the light entrance end to a thickest part of the light guide plate in an entrance direction, and Kc represents a compensation coefficient, in Expression (3), θ
represents the angle formed between the two straight lines of the equal lengths, and in Expression (4), θ
1 represents an angle formed between a perpendicular from a vertex of each of the vertex angles of the plurality of prisms with respect to a bottom of each of the plurality of prisms and one of the straight lines of the different lengths, and θ
2 represents an angle formed between the perpendicular and another of the straight lines of the different lengths. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32)
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33. A planar lighting device, comprising:
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a light guide plate assembly; and light sources linearly arranged to face the light entrance end of the light guide plate of the light guide plate assembly, wherein said light guide plate assembly comprises; a light guide plate which includes a light exit plane for emitting a planar light and a light entrance end disposed in one end of the light exit plane and substantially orthogonal to the light exit plane, is formed into a shape having a thickness in a direction orthogonal to the light exit plane, the thickness being gradually larger as being farther from the light entrance end, and contains scattering particles dispersed therein; and a prism sheet which includes a plurality of prisms arrayed in parallel with each other, and is arranged so that vertex angles of the plurality of prisms face the light exit plane of the light guide plate, wherein; the scattering particles scatter light entering from the light entrance end and propagating in the light guide plate, which satisfy Expressions (1) and (2) below; when lengths of two straight lines sandwiching each of the vertex angles of the plurality of prisms of the prism sheet are equal to each other, an angle formed between the two straight lines of the equal lengths satisfies Expression (3) below; and when the lengths of the two straight lines sandwiching the each of the vertex angles of the plurality of prisms are different from each other, an angle formed between the straight lines of the different lengths satisfies Expression (4) below,
1.1≦
Φ
NpLGKC≦
8.2
(1)
0.005≦
Kc≦
0.1
(2)
55°
≦
θ
≦
80°
(3)
0°
≦
θ
1≦
15° and
30°
≦
θ
2≦
45°
(4)in Expressions (1) and (2), Φ
represents a scattering cross section [m2] of the scattering particles, NP represents a density [pieces/m2] of the scattering particles, LG[m] represents a length extending from the light entrance end to a thickest part of the light guide plate in an entrance direction, and KC represents a compensation coefficient, in Expression (3), θ
represents the angle formed between the two straight lines of the equal lengths, and in Expression (4), θ
1 represents an angle formed between a perpendicular from a vertex of each of the vertex angles of the plurality of prisms with respect to a bottom of each of the plurality of prisms and one of the straight lines of the different lengths, and θ
2 represents an angle formed between the perpendicular and another of the straight lines of the different lengths. - View Dependent Claims (34)
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35. A light guide plate made of a transparent resin for converting light of light sources into planar light, comprising:
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a light exit plane having a rectangular outer shape; four light entrance planes which are connected to four sides of the light exit plane and are substantially orthogonal to the light exit plane; and a backside which is planes opposed to the light exit plane and includes four inclined planes inclined to be farther from the light exit plane toward a center from the four light entrance planes, wherein a minimum thickness is in the four light entrance planes and a maximum thickness is in the center from the four light entrance planes. - View Dependent Claims (36, 37, 38, 39, 40)
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41. A planar lighting device for generating a planar illumination light, comprising:
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a light guide plate being made of a transparent resin; and
four light sources, each arranged to face the four light entrance planes of the light guide plate,wherein said light guide plate for converting light of the four light source into the planar illumination light comprises; a light exit plane having a rectangular outer shape;
four light entrance planes which are connected to four sides of the light exit plane and are substantially orthogonal to the light exit plane; anda backside which is planes opposed to the light exit plane and includes four inclined planes inclined to be farther from the light exit plane toward a center from the four light entrance planes, and wherein a minimum thickness is in the four light entrance planes and a maximum thickness is in the center from the four light entrance planes. - View Dependent Claims (42, 43, 44, 45)
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46. A liquid crystal display device, comprising:
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a planar lighting device; a liquid crystal display panel disposed on a light exit plane side of the planar lighting device; and a drive unit for driving the liquid crystal display panel, wherein said planar lighting device comprises; a light guide plate assembly; and light sources linearly arranged to face the light entrance end of the light guide plate of the light guide plate assembly, and wherein said light guide plate assembly comprises; a light guide plate which includes a light exit plane for emitting a planar light and a light entrance end disposed in one end of the light exit plane and substantially orthogonal to the light exit plane, is formed into a shape having a thickness in a direction orthogonal to the light exit plane, the thickness being gradually larger as being farther from the light entrance end, and contains scattering particles dispersed therein; and a prism sheet which includes a plurality of prisms arrayed in parallel with each other, and is arranged so that vertex angles of the plurality of prisms face the light exit plane of the light guide plate, wherein; the scattering particles scatter light entering from the light entrance end and propagating in the light guide plate, which satisfy Expressions (1) and (2) below; when lengths of two straight lines sandwiching each of the vertex angles of the plurality of prisms of the prism sheet are equal to each other, an angle formed between the two straight lines of the equal lengths satisfies Expression (3) below; and when the lengths of the two straight lines sandwiching the each of the vertex angles of the plurality of prisms are different from each other, an angle formed between the straight lines of the different lengths satisfies Expression (4) below,
1.1≦
Φ
NpLGKC≦
8.2
(1)
0.005≦
Kc≦
0.1
(2)
55°
≦
θ
≦
80°
(3)
0°
≦
θ
1≦
15° and
30°
≦
θ
2≦
45°
(4)in Expressions (1) and (2), Φ
represents a scattering cross section [m2] of the scattering particles, NP represents a density [pieces/m2] of the scattering particles, LG[m] represents a length extending from the light entrance end to a thickest part of the light guide plate in an entrance direction, and KC represents a compensation coefficient, in Expression (3), θ
represents the angle formed between the two straight lines of the equal lengths, and in Expression (4), θ
1 represents an angle formed between a perpendicular from a vertex of each of the vertex angles of the plurality of prisms with respect to a bottom of each of the plurality of prisms and one of the straight lines of the different lengths, and θ
2 represents an angle formed between the perpendicular and another of the straight lines of the different lengths.
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47. A liquid crystal display device, comprising:
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a planar lighting device for generating a planar illumination light; a liquid crystal display panel disposed on a light exit plane side of the planar lighting device; and a drive unit for driving the liquid crystal display panel, wherein said planar lighting device comprises; a light guide plate being made of a transparent resin; and
four light sources, each arranged to face the four light entrance planes of the light guide plate,wherein said light guide plate for converting light of the four light source into the planar illumination light comprises; a light exit plane having a rectangular outer shape; four light entrance planes which are connected to four sides of the light exit plane and are substantially orthogonal to the light exit plane; and a backside which is planes opposed to the light exit plane and includes four inclined planes inclined to be farther from the light exit plane toward a center from the four light entrance planes, and wherein a minimum thickness is in the four light entrance planes and a maximum thickness is in the center from the four light entrance planes.
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Specification