Display device having a light source with transparent/scattering state switching element
View Patent ↗A display device is provided with a light source, an light-guide plate, a prism sheet, a transparent/scattering state switching element, and a transmissive liquid crystal display panel. In the transparent/scattering state switching element, two transparent substrates are provided parallel to and separated from each other, and an electrode is provided to the surface of each transparent substrate. A scattering seal member is also provided between external peripheral portions of the transparent substrates, and a PDLC layer is enclosed in a space sealed by the scattering seal member between the transparent substrates. The scattering seal member is endowed with scattering properties whereby incident light is transmitted in a scattered state, and the degree of scattering thereof is equal to the degree of scattering of the PDLC layer during the scattering state.
1. A light source device comprising:
a planar light source for emitting light in a plane; and
a transparent/scattering state switching element capable of switching between a state for transmitting light emitted from the planar light source, and a state for scattering the light;
wherein:
said transparent/scattering state switching element comprises:
two transparent substrates;
a seal member disposed between external peripheral portions of the two transparent substrates; and
a transparent/scattering state switching layer that is capable of switching between a state for transmitting incident light and a state for scattering incident light and that is enclosed in a region sealed by said seal member between said two transparent substrates;
the luminance of light that has passed through the region in which the seal member is disposed in the transparent/scattering state switching element is lower than before the light passed through this region; and
a frontal luminance of light that has passed through the region in which the seal member is disposed is not greater than a frontal luminance of light that has passed through the transparent/scattering state switching layer in the scattering state,
wherein said transparent/scattering state switching element has a light-shielding layer for blocking light; and
wherein a cross-sectional area of said light-shielding layer is the same as a cross-sectional area of said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.
2. The light source device according to claim 1 , wherein
a region in which said seal member is disposed in said transparent/scattering state switching element is not transparent, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.
3. The light source device according to claim 1 , wherein
said seal member has scattering properties that yield a degree of scattering equal to a degree of scattering of said transparent/scattering state switching layer in said scattering state.
4. The light source device according to claim 1 , wherein
said seal member has scattering properties that yield a degree of scattering greater than a degree of scattering of said transparent/scattering state switching layer in said scattering state.
5. The light source device according to claim 1 , wherein
light is scattered by a region overlapping said seal member in at least one of said transparent substrates, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.
6. The light source device according to claim 1 , wherein
an uneven shape is formed in a region overlapping said seal member in a surface of at least one of said transparent substrates, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.
7. The light source device according to claim 1 , further comprising;
a scattering double-sided adhesive tape that is non-transparent and is disposed on a side of a light-emitting surface of said planar light source; wherein
the scattering double-sided adhesive tape has a shape that is identical to the shape of the seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.
8. The light source device according to claim 1 , further comprising;
a scattering double-sided adhesive tape that has scattering properties and is disposed on a side of a light-emitting surface of said planar light source; wherein
the scattering double-sided adhesive tape has a shape that is identical to the shape of the seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and the scattering double-sided adhesive tape has a degree of scattering that is equal to the degree of scattering of the transparent/scattering state switching layer in the scattering state.
9. The light source device according to claim 1 , further comprising;
a scattering double-sided adhesive tape that has scattering properties and is disposed on a side of a light-emitting surface of said planar light source; wherein
the scattering double-sided adhesive tape has a shape that is identical to the shape of the seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and a degree of scattering of said scattering double-sided adhesive tape is greater than a degree of scattering of said transparent/scattering state switching layer in said scattering state.
10. The light source device according to claim 1 , further comprising;
a transparent/scattering double-sided adhesive tape disposed on a side of a light-emitting surface of said planar light source; wherein
light is scattered by a portion overlapping said seal member in said transparent/scattering double-sided adhesive tape, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and a portion overlapping said transparent/scattering state switching layer is transparent.
11. The light source device according to claim 1 , further comprising;
a transparent/scattering double-sided adhesive tape disposed on a side of a light-emitting surface of said planar light source; wherein
light is scattered by a portion overlapping said seal member in said transparent/scattering double-sided adhesive tape, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element;
a portion overlapping said transparent/scattering state switching layer is transparent; and
a degree of scattering of said portion overlapping the seal member is the same as a degree of scattering of said transparent/scattering state switching layer in said scattering state.
12. The light source device according to claim 1 , further comprising;
a transparent/scattering double-sided adhesive tape disposed on a side of a light-emitting surface of said planar light source; wherein
light is scattered by a portion overlapping said seal member in said transparent/scattering double-sided adhesive tape, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element;
a portion overlapping said transparent/scattering state switching layer is transparent; and
a degree of scattering of said portion overlapping the seal member is greater than a degree of scattering of said transparent/scattering state switching layer in said scattering state.
13. The light source device according to claim 1 , further comprising;
said seal member has light absorption properties whereby light is absorbed.
14. The light source device according to claim 13 , wherein said seal member is colorless.
15. The light source device according to claim 13 , wherein said seal member is black.
16. The light source device according to claim 1 , further comprising;
said seal member has light absorption properties whereby light is absorbed, and an optical density of said seal member is set so that a frontal luminance of light emitted from the seal member is equal to a frontal luminance of light emitted from said transparent/scattering state switching layer in said scattering state.
17. The light source device according to claim 1 , further comprising;
said seal member has light absorption properties whereby light is absorbed, and an optical density of said seal member is set so that a frontal luminance of light emitted from the seal member is lower than a frontal luminance of light emitted from said transparent/scattering state switching layer in said scattering state.
18. The light source device according to claim 1 , wherein said light-shielding layer is formed on a surface of one of said transparent substrates that is opposite the other of said transparent substrates.
19. The light source device according to claim 1 , further comprising;
a light-absorbing double-sided adhesive tape that absorbs light and is disposed on a side of a light-emitting surface of said planar light source; wherein
a shape of said light-absorbing double-sided adhesive tape is the same as a shape of said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.
20. The light source device according to claim 1 , further comprising;
a light-absorbing double-sided adhesive tape that absorbs light and is disposed on a side of a light-emitting surface of said planar light source; wherein
a shape of said light-absorbing double-sided adhesive tape is the same as a shape of said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and an optical density of said light-absorbing double-sided adhesive tape is set so that a frontal luminance of light emitted from the light-absorbing double-sided adhesive tape is equal to a frontal luminance of light emitted from said transparent/scattering state switching layer in said scattering state.
21. The light source device according to claim 1 , further comprising;
a light-absorbing double-sided adhesive tape that absorbs light and is disposed on a side of a light-emitting surface of said planar light source; wherein
a shape of said light-absorbing double-sided adhesive tape is the same as a shape of said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and an optical density of said light-absorbing double-sided adhesive tape is set so that a frontal luminance of light emitted from the light-absorbing double-sided adhesive tape is lower than a frontal luminance of light emitted from said transparent/scattering state switching layer in said scattering state.
22. The light source device according to any one of claims 19 , 20 and 21 , wherein said light-absorbing double-sided adhesive tape is colorless.
23. The light source device according to any one of claims 19 , 20 and 21 , wherein said light-absorbing double-sided adhesive tape is black.
24. The light source device according to claim 1 , further comprising;
a transparent/light-absorbing double-sided adhesive tape disposed on a side of a light-emitting surface of said planar light source; wherein
light is scattered by a portion overlapping said seal member in said transparent/light-absorbing double-sided adhesive tape, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and a portion overlapping said transparent/scattering state switching layer is transparent.
25. The light source device according to claim 24 , wherein said portion of the transparent/light-absorbing double-sided adhesive tape that overlaps said seal member is colorless.
26. The light source device according to claim 24 , wherein said portion of the transparent/light-absorbing double-sided adhesive tape that overlaps said seal member is black.
27. The light source device according to claim 1 , further comprising;
a transparent/light-absorbing double-sided adhesive tape disposed on a side of a light-emitting surface of said planar light source; wherein
light is absorbed by a portion overlapping said seal member in said transparent/light-absorbing double-sided adhesive tape, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element;
a portion overlapping said transparent/scattering state switching layer is transparent; and
an optical density of said portion overlapping the seal member is set so that a frontal luminance of light emitted from this portion is equal to a frontal luminance of light emitted from said transparent/scattering state switching layer in said scattering state.
28. The light source device according to claim 1 , further comprising;
a transparent/light-absorbing double-sided adhesive tape disposed on a side of a light-emitting surface of said planar light source; wherein
light is absorbed by a portion overlapping said seal member in said transparent/light-absorbing double-sided adhesive tape, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element;
a portion overlapping said transparent/scattering state switching layer is transparent; and
an optical density of said portion overlapping the seal member is set so that a frontal luminance of light emitted from this portion is lower than a frontal luminance of light emitted from said transparent/scattering state switching layer in said scattering state.
29. The light source device according to claim 1 , wherein,
a transmittance of light in a region in which said seal member is interposed in a light path that extends from said planar light source to said display panel is lower than a transmittance of light when said transparent/scattering state switching layer is in said transparent state in the area in which said transparent/scattering state switching layer is interposed.
30. The light source device according to claim 1 , further comprising;
a light-direction regulating element which is disposed between said planar light source and said transparent/scattering state switching element to regulate a direction of light emitted from the planar light source and output light into said transparent/scattering state switching element, and wherein
an uneven shape is formed in a region of a surface of said light-direction regulating element that overlaps said seal member, as viewed from a direction perpendicular to a surface of said display panel.
31. The light source device according to claim 1 , wherein said planar light source comprises a light source; and a light-guiding member for emitting in a plane light that is incident from the light source.
32. A display device comprising:
the light source device according to claim 1 ; and
a display panel for displaying an image by transmitting light emitted from the transparent/scattering state switching element.
33. The display device according to claim 32 , further comprising;
a scattering double-sided adhesive tape that is non-transparent and is disposed on a side of a light-emitting surface of said planar light source; wherein
said scattering double-sided adhesive tape has a shape that is identical to the shape of the seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element;
said scattering double-sided adhesive tape is disposed between said transparent/scattering state switching element and said display panel; and
said transparent/scattering state switching element and said display panel are fixed relative to each other by said scattering double-sided adhesive tape.
34. The display device according to claim 32 , further comprising;
a scattering double-sided adhesive tape that has scattering properties and is disposed on a side of a light-emitting surface of said planar light source; wherein
said scattering double-sided adhesive tape has a shape that is identical to the shape of the seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and the scattering double-sided adhesive tape has a degree of scattering that is equal to the degree of scattering of the transparent/scattering state switching layer in the scattering state;
said scattering double-sided adhesive tape is disposed between said transparent/scattering state switching element and said display panel; and
said transparent/scattering state switching element and said display panel are fixed relative to each other by said scattering double-sided adhesive tape.
35. The display device according to claim 32 , further comprising;
a scattering double-sided adhesive tape that has scattering properties and is disposed on a side of a light-emitting surface of said planar light source; wherein
said scattering double-sided adhesive tape has a shape that is identical to the shape of the seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and a degree of scattering of said scattering double-sided adhesive tape is greater than a degree of scattering of said transparent/scattering state switching layer in said scattering state;
said scattering double-sided adhesive tape is disposed between said transparent/scattering state switching element and said display panel; and
said transparent/scattering state switching element and said display panel are fixed relative to each other by said scattering double-sided adhesive tape.
36. The display device according to claim 32 , further comprising;
a light-absorbing double-sided adhesive tape that absorbs light and is disposed on a side of a light-emitting surface of said planar light source; wherein
a shape of said light-absorbing double-sided adhesive tape is the same as a shape of said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element;
said light-absorbing double-sided adhesive tape is disposed between said transparent/scattering state switching element and said display panel; and
said transparent/scattering state switching element and said display panel are fixed relative to each other by said light-absorbing double-sided adhesive tape.
37. The display device according to claim 32 , further comprising;
a light-absorbing double-sided adhesive tape that absorbs light and is disposed on a side of a light-emitting surface of said planar light source; wherein
a shape of said light-absorbing double-sided adhesive tape is the same as a shape of said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and an optical density of said light-absorbing double-sided adhesive tape is set so that a frontal luminance of light emitted from the light-absorbing double-sided adhesive tape is equal to a frontal luminance of light emitted from said transparent/scattering state switching layer in said scattering state;
said light-absorbing double-sided adhesive tape is disposed between said transparent/scattering state switching element and said display panel; and
said transparent/scattering state switching element and said display panel are fixed relative to each other by said light-absorbing double-sided adhesive tape.
38. The display device according to claim 32 , further comprising;
a light-absorbing double-sided adhesive tape that absorbs light and is disposed on a side of a light-emitting surface of said planar light source; wherein
a shape of said light-absorbing double-sided adhesive tape is the same as a shape of said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and an optical density of said light-absorbing double-sided adhesive tape is set so that a frontal luminance of light emitted from the light-absorbing double-sided adhesive tape is lower than a frontal luminance of light emitted from said transparent/scattering state switching layer in said scattering state;
said light-absorbing double-sided adhesive tape is disposed between said transparent/scattering state switching element and said display panel; and
said transparent/scattering state switching element and said display panel are fixed relative to each other by said light-absorbing double-sided adhesive tape.
39. A terminal device comprising the display device according to claim 32 .
40. The terminal device according to claim 39 , comprising a mobile telephone, a personal information terminal, a gaming device, a digital camera, a video camera, a video player, a notebook-type personal computer, a cash dispenser, or a vending machine.
41. An optical member comprising:
a transparent/scattering state switching element capable of switching between a state for transmitting incident light, and a state for scattering the light; wherein:
said transparent/scattering state switching element comprises:
two transparent substrates;
a seal member disposed between external peripheral portions of the two transparent substrates; and
a transparent/scattering state switching layer that is capable of switching between a state for transmitting incident light and a state for scattering incident light and that is enclosed in a region sealed by said seal member between said two transparent substrates;
the luminance of light that has passed through the region in which the seal member is disposed in the transparent/scattering state switching element is lower than before the light passed through this region; and
a frontal luminance of light that has passed through the region in which the seal member is disposed is not greater than a frontal luminance of light that has passed through the transparent/scattering state switching layer in the scattering state,
wherein said transparent/scattering state switching element has a light-shielding layer for blocking light; and
wherein a cross-sectional area of said light-shielding layer is the same as a cross-sectional area of said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.
42. The optical member according to claim 41 , wherein
said seal member has scattering properties that yield a degree of scattering equal to a degree of scattering of said transparent/scattering state switching layer in said scattering state.
43. The optical member according to claim 41 , wherein
said seal member has scattering properties that yield a degree of scattering greater than a degree of scattering of said transparent/scattering state switching layer in said scattering state.
44. The optical member according to claim 41 , wherein
light is scattered by a region overlapping said seal member in at least one of said transparent substrates, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.
45. The optical member according to claim 41 , wherein
an uneven shape is formed in a region overlapping said seal member in a surface of at least one of said transparent substrates, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.
46. The optical member according to claim 41 , further comprising;
a scattering double-sided adhesive tape that is non-transparent and is affixed to said transparent/scattering state switching element; wherein
the scattering double-sided adhesive tape has a shape that is identical to the shape of the seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.
47. The optical member according to claim 41 , further comprising;
a scattering double-sided adhesive tape that has scattering properties and is affixed to said transparent/scattering state switching element; wherein
the scattering double-sided adhesive tape has a shape that is identical to the shape of the seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and the scattering double-sided adhesive tape has a degree of scattering that is equal to the degree of scattering of the transparent/scattering state switching layer in the scattering state.
48. The optical member according to claim 41 , further comprising;
a scattering double-sided adhesive tape that has scattering properties and is affixed to said transparent/scattering state switching element; wherein
the scattering double-sided adhesive tape has a shape that is identical to the shape of the seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and a degree of scattering of said scattering double-sided adhesive tape is greater than a degree of scattering of said transparent/scattering state switching layer in said scattering state.
49. The optical member according to claim 41 , further comprising;
a transparent/scattering double-sided adhesive tape affixed to said transparent/scattering state switching element; wherein
light is scattered by a portion overlapping said seal member in said transparent/scattering double-sided adhesive tape, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and a portion overlapping said transparent/scattering state switching layer is transparent.
50. The optical member according to claim 41 , further comprising;
a transparent/scattering double-sided adhesive tape affixed to said transparent/scattering state switching element; wherein
light is scattered by a portion overlapping said seal member in said transparent/scattering double-sided adhesive tape, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element;
a portion overlapping said transparent/scattering state switching layer is transparent; and
a degree of scattering of said portion overlapping the seal member is the same as a degree of scattering of said transparent/scattering state switching layer in said scattering state.
51. The optical member according to claim 41 , further comprising;
a transparent/scattering double-sided adhesive tape affixed to said transparent/scattering state switching element; wherein
light is scattered by a portion overlapping said seal member in said transparent/scattering double-sided adhesive tape, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element;
a portion overlapping said transparent/scattering state switching layer is transparent; and
a degree of scattering of said portion overlapping the seal member is greater than a degree of scattering of said transparent/scattering state switching layer in said scattering state.
52. The optical member according to claim 41 , wherein
said seal member has light absorption properties whereby light is absorbed.
53. The optical member according to claim 52 , wherein said seal member is colorless.
54. The optical member according to claim 52 , wherein said seal member is black.
55. The optical member according to claim 41 , wherein said light-shielding layer is formed on a surface of one of said transparent substrates, said surface being opposite the other of said transparent substrates.
56. The display device according to claim 41 , further comprising;
a light-absorbing double-sided adhesive tape that absorbs light and is affixed to said transparent/scattering state switching element; wherein
a shape of said light-absorbing double-sided adhesive tape is the same as a shape of said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.
57. The optical member according to claim 56 , wherein said light-absorbing double-sided adhesive tape is colorless.
58. The optical member according to claim 56 , wherein said light-absorbing double-sided adhesive tape is black.
59. The optical member according to claim 41 , further comprising;
a transparent/light-absorbing double-sided adhesive tape affixed to said transparent/scattering state switching element; wherein
light is scattered by a portion overlapping said seal member in said transparent/light-absorbing double-sided adhesive tape, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element, and a portion overlapping said transparent/scattering state switching layer is transparent.
60. The optical member according to claim 59 , wherein said portion of the transparent/light-absorbing double-sided adhesive tape that overlaps said seal member is colorless.
61. The optical member according to claim 59 , wherein said portion of the transparent/light-absorbing double-sided adhesive tape that overlaps said seal member is black.
62. An optical member comprising:
a light-direction regulating element for regulating a direction of incident light; and
a transparent/scattering state switching element capable of switching between a state for transmitting light emitted from the light-direction regulating element, and a state for scattering the light; wherein:
said transparent/scattering state switching element comprises:
two transparent substrates;
a seal member disposed between external peripheral portions of the two transparent substrates; and
a transparent/scattering state switching layer that is capable of switching between a state for transmitting incident light and a state for scattering incident light and that is enclosed in a region sealed by said seal member between said two transparent substrates;
an uneven shape is formed in a region of a surface of said light-direction regulating element that overlaps said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element; and
a frontal luminance of light that has passed through the region in which the seal member is disposed is not greater than a frontal luminance of light that has passed through the transparent/scattering state switching layer in the scattering state,
wherein said transparent/scattering state switching element has a light-shielding layer for blocking light; and
wherein a cross-sectional area of said light-shielding layer is the same as a cross-sectional area of said seal member, as viewed from a direction perpendicular to a surface of said transparent/scattering state switching element.