Backlight having light guide plate with side surface with inclination angle and image display device
A backlight comprises a light guide plate and a light emitting element. The light guide plate has a first main surface, a second main surface opposite the first main surface, and a side surface connecting the first main surface and the second main surface, the side surface having a first region and a second region different from the first region. The light emitting element emits light toward the first region of the side surface of the light guide plate. The side surface of the light guide plate includes, in the second region of the side surface of the light guide plate, a first inclined surface that extends from an outer edge of the first main surface in an inclined manner and has an inclination angle between 52° and 83° with respect to the first main surface.
1. A backlight comprising:
a light guide plate having a first main surface, a second main surface opposite the first main surface, and a side surface connecting the first main surface and the second main surface, the side surface having a first region and a second region different from the first region; and
a light emitting element that emits light toward the first region of the side surface of the light guide plate,
the side surface of the light guide plate including, in the second region of the side surface of the light guide plate, a first inclined surface that extends from an outer edge of the first main surface in an inclined manner and has an inclination angle between 52° and 70° with respect to the first main surface such that there is an increased light utilization efficiency effect of the light guide plate,
the light guide plate being formed in a rectangular shape,
the first region of the side surface of the light guide plate being disposed corresponding to one edge of the light guide plate, and
the second region of the side surface of the light guide plate being disposed corresponding to the other three edges of the light guide plate.
2. A backlight comprising:
a light guide plate having a first main surface, a second main surface opposite the first main surface, and a side surface connecting the first main surface and the second main surface, the side surface having a first region and a second region different from the first region; and
a light emitting element that emits light toward the first region of the side surface of the light guide plate,
the side surface of the light guide plate including, in the second region of the side surface of the light guide plate, a first inclined surface that extends from an outer edge of the first main surface in an inclined manner and has an inclination angle between 62° and 83° with respect to the first main surface such that there is an increased luminance effect at an end portion,
the light guide plate being formed in a rectangular shape,
the first region of the side surface of the light guide plate being disposed corresponding to one edge of the light guide plate,
the second region of the side surface of the light guide plate being disposed corresponding to the other three edges of the light guide plate.
3. The backlight according to claim 1 , wherein
the side surface of the light guide plate further includes, in the second region of the side surface of the light guide plate, a second inclined surface that extends from an outer edge of the second main surface in an inclined manner to connect the second main surface and the first inclined surface and has an inclination angle between 52° and 83° with respect to the second main surface.
4. The backlight according to claim 3 , wherein
the inclination angle of the second inclined surface is between 62° and 83° with respect to the second main surface.
5. The backlight according to claim 3 , wherein
the inclination angle of the first inclined surface and the inclination angle of the second inclined surface are equal to each other.
6. The backlight according to claim 3 , wherein
the first inclined surface and the second inclined surface are connected to each other to form an edge of the light guide plate that extends parallel to the outer edge of the first main surface or the outer edge of the second main surface.
7. The backlight according to claim 1 , wherein
the first inclined surface extends from the outer edge of the first main surface to an outer edge of the second main surface.
8. The backlight according to claim 1 , further comprising
an optical sheet arranged to cover the first main surface of the light guide plate, and
a frame member holding an outer periphery of the optical sheet against the first main surface of the light guide plate,
wherein a distance from the outer edge of the first main surface of the light guide plate to an end portion of the frame member is between 0.5 mm to 5.0 mm.
9. The backlight according to claim 1 , further comprising a reflective sheet arranged to cover the second main surface of the light guide plate.
10. The backlight according to claim 9 , wherein
the reflective sheet has an outer edge that extends along an outer edge of the second main surface of the light guide plate.
11. The backlight according to claim 1 , wherein
the second main surface of the light guide plate includes a plurality of light diffusing portions.
12. The backlight according to claim 1 , wherein
the light emitting element includes a plurality of light emitting diodes that is arranged relative to each other along the first region of the side surface of the light guide plate.
13. An image display device comprising:
a display panel configured to display image on a front surface; and
the backlight according to claim 1 .
14. The image display device according to claim 13 , wherein
the first main surface of the light guide plate of the backlight is disposed facing a back surface of the display panel.
15. The backlight according to claim 6 , wherein
the edge of the light guide plate extends along an entirety of the second region of the side surface of the light guide plate.
16. The backlight according to claim 6 , wherein
the light guide plate has an overall rectangular shape, and
the edge of the light guide plate has a linear edge portion that extends along the outer edge of the first main surface or the outer edge of the second main surface.
17. The backlight according to claim 16 , wherein
the edge of the light guide plate linearly extends along an entire width of the light guide plate.
18. The backlight according to claim 6 , wherein
the light guide plate has an overall circular shape, and
the edge of the light guide plate has a curved edge portion that extends along the outer edge of the first main surface or the outer edge of the second main surface.
19. The backlight according to claim 11 , wherein
the light diffusing portions include a plurality of dot patterns to diffuse light.