Light emitting module, surface light source, liquid crystal display, and illuminating device

• US 9,091,882 B2
• Filed: 11/12/2010
• Issued: 07/28/2015
• Est. Priority Date: 11/30/2009
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Hineno, Mitsuru, Tatsumi, Masaki
• Primary Examiner(s): COUGHLIN, ANDREW J
• Application Number:
  US13/508,868
• Publication Number:
  US 20120320309A1
• Time in Patent Office: 1,719 Days
• Field of Search: 349/64, 362/231, 362/268, 362/308, 362/328
• US Class Current: 1/1
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133609 including means for improving the color mixing, e.g. white

Abstract

The purpose of the present invention is providing a light emitting module capable of emitting illumination light having a nearly uniform color tone as a whole. The invention also provides a surface light source having such light emitting modules, and a liquid crystal display and an illuminating device having such a surface light source.

In a light emitting module (50), adjacent dot light sources (17, 17) satisfy the relationships ΔX1+ΔX2=ΔX×2 and ΔY1+ΔY2=ΔY×2, so that the resultant mixed color can fall within a target chromaticity rank area (M), and the center (gc) of a first chromaticity rank area g and the center (Ec) of a second chromaticity rank area (E) are axisymmetric with respect to virtual straight lines (gE1, gE2) that pass through the center (Mc) of the target chromaticity rank area (M) and parallel to one side or another side of the target chromaticity rank area (M).

Claims

1. A light emitting module comprising:

a substrate; and

a plurality of dot light sources placed on the substrate and configured to emit white light,

wherein each of the dot light sources is classified into a chromaticity rank on CIE 1931 coordinates according to its chromaticity,

one dot light source, out of adjacent dot light sources, belongs to a parallelogram-shaped first chromaticity rank area, and the other dot light source belongs to a parallelogram-shaped second chromaticity rank area,

one side, or another side not in parallel with the one side, of each of the first and second chromaticity rank areas is parallel to one side, or another side not in parallel with the one side, of a parallelogram-shaped target chromaticity rank area,

assuming that an x-coordinate difference that is a chromaticity coordinate difference of the one side of the target chromaticity rank area projected on the x-axis is Δ

X, the one side being on the side allowed be directly projected on the x-axis, and a y-coordinate difference that is a chromaticity coordinate difference of the another side of the target chromaticity rank area projected on the y-axis is Δ

Y, the another side being the side that can be directly projected on the y-axis,

that an x-coordinate difference that is a chromaticity coordinate difference of the one side of the first chromaticity rank area projected on the x-axis is Δ

X1, the one side being the side that can be directly projected on the x-axis, and a y-coordinate difference that is a chromaticity coordinate difference of the another side of the first chromaticity rank area projected on the y-axis is Δ

Y1, the another side being the side that can be directly projected on the y-axis, and

that an x-coordinate difference that is a chromaticity coordinate difference of the one side of the second chromaticity rank area projected on the x-axis is Δ

X2, the one side being the side that can be directly projected on the x-axis, and a y-coordinate difference that is a chromaticity coordinate difference of the another side of the second chromaticity rank area projected on the y-axis is Δ

Y2, the another side being the side that can be directly projected on the y-axis,

the adjacent dot light sources satisfy relationships

Δ

X1+Δ

X2=Δ

X×

2

and

Δ

Y1+Δ

Y2=Δ

Y×

2

 

so that the resultant mixed color can fall within the target chromaticity rank area, and

the center of the first chromaticity rank area and the center of the second chromaticity rank area are axisymmetric with respect to a virtual straight line that passes through the center of the target chromaticity rank area and is parallel to the one side or the another side of the target chromaticity rank area.

2. The light emitting module of claim 1,

wherein the one dot light source belongs to a third chromaticity rank area that is included in the first chromaticity rank area and smaller in size than the first chromaticity rank area, and the other dot light source belongs to a fourth chromaticity rank area that is included in the second chromaticity rank area and smaller in size than the second chromaticity rank area.

3. The light emitting module of claim 2,

wherein the one and other dot light sources respectively belong to fifth and sixth chromaticity rank areas that are respectively at positions symmetric to the third and fourth chromaticity rank areas with respect to the center of the target chromaticity rank area and the same in shape as the third and fourth chromaticity rank areas.

4. The light emitting module of claim 3,

wherein either one of the third and fourth chromaticity rank areas is at least placed within the target chromaticity rank area.

5. The light emitting module of claim 4,

wherein the third chromaticity rank area is apart from the fourth chromaticity rank area.

6. The light emitting module of claim 4,

wherein the third chromaticity rank area is opposed to the fifth chromaticity rank area with the target chromaticity rank area interposed therebetween.

7. The light emitting module of claim 6,

wherein the fourth chromaticity rank area is within the target chromaticity rank area and does not overlap the sixth chromaticity rank area.

8. The light emitting module of claim 6,

wherein the one and other dot light sources of the adjacent dot light sources respectively belong to fifth and sixth chromaticity rank areas that are respectively at positions symmetric to the third and fourth chromaticity rank areas with respect to the center of the target chromaticity rank area and the same in shape as the third and fourth chromaticity rank areas.

9. The light emitting module of claim 4,

wherein the third chromaticity rank area is the same in area as the fifth chromaticity rank area.

10. The light emitting module of claim 9,

wherein the third and fourth chromaticity rank areas are quadrangular, and

the third chromaticity rank area is placed adjacent to the fourth chromaticity rank area with its side in contact with one side of the fourth chromaticity rank area.

11. The light emitting module of claim 10,

wherein the one and other dot light sources of the adjacent dot light sources respectively belong to fifth and sixth chromaticity rank areas that are respectively at positions symmetric to the third and fourth chromaticity rank areas with respect to the center of the target chromaticity rank area and the same in shape as the third and fourth chromaticity rank areas.

12. A surface light source including a plurality of light emitting modules and a housing, the surface light source being formed by arranging the light emitting modules in a matrix on the housing,

wherein the light emitting modules each have a plurality of dot light sources arranged in line on a substrate,

wherein the light emitting modules include a third light emitting module that is the light emitting module of claim 9, and

wherein at least either one of light emitting modules adjacent in a direction orthogonal to the direction of arrangement of the dot light sources is the third light emitting module.

13. A liquid crystal display comprising the surface light source of claim 12, an optical sheet, and a liquid crystal panel.

14. An illuminating device comprising the surface light source of claim 12 and a diffuser.

15. The light emitting module of claim 2,

wherein the third and fourth chromaticity rank areas are in a shape of a parallelogram of which one side and another side not in parallel with the one side are respectively parallel to the one side and the another side not in parallel with the one side of the target chromaticity rank area.

16. The light emitting module of claim 2,

wherein the third chromaticity rank area is in a shape of a trapezoid formed by cutting away part of the parallelogram.

17. The light emitting module of claim 2,

wherein the third and fourth chromaticity rank areas are smaller in size than the target chromaticity rank area.

18. The light emitting module of claim 2,

wherein the target chromaticity rank area is set within a square chromaticity rank area having vertices at four chromaticity points (Xm+0.01, Ym+0.01), (Xm−

0.01, Ym−

0.01), (Xm+0.01, Ym−

0.01), and (Xm−

0.01, Ym+0.01) defined with respect to the chromaticity point (Xm, Ym) of the center.

19. The light emitting module of claim 1,

wherein the substrate is long shaped, and the plurality of spot light sources are placed linearly along the length of the substrate.

20. The light emitting module of claim 19,

wherein the plurality of spot light sources are placed on the substrate at equal intervals.

21. The light emitting module of claim 1,

wherein the plurality of spot light sources have the same configuration.

22. A surface light source comprising:

light emitting modules including a plurality of dot light sources mounted on a substrate; and

a housing;

wherein the plurality of dot light sources emit white light, and the substrate is long shaped,

wherein, in each of the light emitting modules, the plurality of dot light sources is placed linearly along the length of the substrate, and the light emitting modules are arranged in a matrix on the housing,

wherein each of the dot light sources is classified into a chromaticity rank on CIE 1931 coordinates according to its chromaticity,

wherein one dot light source, out of adjacent dot light sources, belongs to a parallelogram-shaped first chromaticity rank area, and the other dot light source belongs to a parallelogram-shaped second chromaticity rank area,

wherein one side, or another side not in parallel with the one side, of each of the first and second chromaticity rank areas is parallel to one side, or another side not in parallel with the one side, of a parallelogram-shaped target chromaticity rank area,

wherein, assuming that an x-coordinate difference that is a chromaticity coordinate difference of the one side of the target chromaticity rank area projected on the x-axis is Δ

X, the one side being on the side allowed be directly projected on the x-axis, and a y-coordinate difference that is a chromaticity coordinate difference of the another side of the target chromaticity rank area protected on the y-axis is Δ

Y, the another side being the side that can be directly projected on the y-axis,

that an x-coordinate difference that is a chromaticity coordinate difference of the one side of the first chromaticity rank area projected on the x-axis is Δ

X1, the one side being the side that can be directly projected on the x-axis, and a y-coordinate difference that is a chromaticity coordinate difference of the another side of the first chromaticity rank area projected on the y-axis is Δ

Y1, the another side being the side that can be directly projected on the y-axis, and

that an x-coordinate difference that is a chromaticity coordinate difference of the one side of the second chromaticity rank area projected on the x-axis is Δ

X2, the one side being the side that can be directly projected on the x-axis, and a y-coordinate difference that is a chromaticity coordinate difference of the another side of the second chromaticity rank area projected on the y-axis is Δ

Y2, the another side being the side that can be directly projected on the y-axis,

the adjacent dot light sources satisfy relationships

Δ

X1+Δ

X2=Δ

X×

2

and

Δ

Y1+Δ

Y2=Δ

Y×

2

 

so that the resultant mixed color can fall within the target chromaticity rank area,

wherein the center of the first chromaticity rank area and the center of the second chromaticity rank area are axisymmetric with respect to a virtual straight line that passes through the center of the target chromaticity rank area and is parallel to the one side or the another side of the target chromaticity rank area,

wherein the light emitting modules include;

a first configuration in which the one dot light source belongs to a third chromaticity rank area that is included in the first chromaticity rank area and smaller in size than the first chromaticity rank area, and the other dot light source belongs to a fourth chromaticity rank area that is included in the second chromaticity rank area and smaller in size than the second chromaticity rank area;

a second configuration in which, in the first configuration, the one and other dot light sources respectively belong to fifth and sixth chromaticity rank areas that are respectively at positions symmetric to the third and fourth chromaticity rank areas with respect to the center of the target chromaticity rank area and the same in shape as the third and fourth chromaticity rank areas;

a third configuration in which, in the second configuration, either one of the third and fourth chromaticity rank areas is at least placed within the target chromaticity rank area;

a fourth configuration in which, in the third configuration, the third chromaticity rank area is opposed to the fifth chromaticity rank area with the target chromaticity rank area interposed therebetween; and

a fifth configuration in which, in the fourth configuration, the one and other dot light sources of the adjacent dot light sources respectively belong to fifth and sixth chromaticity rank areas that are respectively at positions symmetric to the third and fourth chromaticity rank areas with respect to the center of the target chromaticity rank area and the same in shape as the third and fourth chromaticity rank areas,

wherein the surface light source includes a first light emitting module that is the light emitting module having the fourth configuration, and a second light emitting module that is the light emitting module having the fifth configuration, and

wherein the first light emitting module and the second light emitting module are placed adjacent to each other on the housing in a direction orthogonal to the direction of arrangement of the dot light sources.

23. A liquid crystal display comprising the surface light source of claim 22, an optical sheet, and a liquid crystal panel.

24. An illuminating device comprising the surface light source of claim 22 and a diffuser.

25. A surface light source comprising;

light emitting modules including a plurality of dot light sources mounted on a substrate; and

a housing,

wherein the plurality of dot light sources emit while light, and the substrate is long shaped,

wherein, in each of the light emitting modules, the plurality of dot light sources is placed linearly along the length of the substrate, and the light emitting modules are arranged in a matrix on the housing,

wherein each of the dot light sources is classified into a chromaticity rank on CIE 1931 coordinates according to its chromaticity,

wherein one dot light source, out of adjacent dot light sources, belongs to a parallelogram-shaped first chromaticity rank area, and the other dot light source belongs to a parallelogram-shaped second chromaticity rank area,

wherein one side, or another side not in parallel with the one side, of each of the first and second chromaticity rank areas is parallel to one side, or another side not in parallel with the one side, of a parallelogram-shaped target chromaticity rank area,

wherein, assuming that an x-coordinate difference that is a chromaticity coordinate difference of the one side of the target chromaticity rank area projected on the x-axis is Δ

X, the one side being on the side allowed be directly projected on the x-axis, and a y-coordinate difference that is a chromaticity coordinate difference of the another side of the target chromaticity rank area projected on the y-axis is Δ

Y, the another side being the side that can be directly projected on the y-axis,

that an x-coordinate difference that is a chromaticity coordinate difference of the one side of the first chromaticity rank area projected on the x-axis is Δ

X1, the one side being the side that can be directly projected on the x-axis, and a y-coordinate difference that is a chromaticity coordinate difference of the another side of the first chromaticity rank area projected on the y-axis is Δ

Y1, the another side being the side that can be directly projected on the y-axis, and

that an x-coordinate difference that is a chromaticity coordinate difference of the one side of the second chromaticity rank area projected on the x-axis is Δ

X2, the one side being the side that can be directly projected on the x-axis, and a y-coordinate difference that is a chromaticity coordinate difference of the another side of the second chromaticity rank area projected on the y-axis is Δ

Y2, the another side being the side that can be directly projected on the y-axis,

the adjacent dot light sources satisfy relationships

Δ

X1+Δ

X2=Δ

X×

2

and

Δ

Y1+Δ

Y2=Δ

Y×

2

 

so that the resultant mixed color can fall within the target chromaticity rank area,

wherein the center of the first chromaticity rank area and the center of the second chromaticity rank area are axisymmetric with respect to a virtual straight line that passes through the center of the target chromaticity rank area and is parallel to the one side or the another side of the target chromaticity rank area,

wherein the light emitting modules include;

a first configuration in which the one dot light source belongs to a third chromaticity rank area that is included in the first chromaticity rank area and smaller in size than the first chromaticity rank area, and the other dot light source belongs to a fourth chromaticity rank area that is included in the second chromaticity rank area and smaller in size than the second chromaticity rank area;

a second configuration in which, in the first configuration, the one and other dot light sources respectively belong to fifth and sixth chromaticity rank areas that are respectively at positions symmetric to the third and fourth chromaticity rank areas with respect to the center of the target chromaticity rank area and the same in shape as the third and fourth chromaticity rank areas;

a third configuration in which, in the second configuration, either one of the third and fourth chromaticity rank areas is at least placed within the target chromaticity rank area;

a sixth configuration in which, in the third configuration, the third chromaticity rank area is the same in area as the fifth chromaticity rank area;

the third and fourth chromaticity rank areas are quadrangular; and

the third chromaticity rank area is placed adjacent to the fourth chromaticity rank area with its side in contact with one side of the fourth chromaticity rank area; and

a seventh configuration in which, in the sixth configuration, the one and other dot light sources of the adjacent dot light sources respectively belong to fifth and sixth chromaticity rank areas that are respectively at positions symmetric to the third and fourth chromaticity rank areas with respect to the center of the target chromaticity rank area and the same in shape as the third and fourth chromaticity rank areas,

wherein the surface light source includes a first light emitting module that is the light emitting module having the sixth configuration, and a second light emitting module that is the light emitting module having the seventh configuration, and

wherein the first light emitting module and the second light emitting module are placed adjacent to each other on the housing in a direction orthogonal to the direction of arrangement of the dot light sources.