Optical sheet, backlight unit, and liquid crystal display
An optical sheet, a backlight unit including the optical sheet and a liquid crystal display including the backlight unit are disclosed. The optical sheet includes a reflective polarizing film, and a first diffusing layer on the reflective polarizing film. The first diffusing layer includes a plurality of first diffusion particles. The first diffusion particles have a volume distribution as a function of diameter. For a diameter D of a first diffusion particle corresponding to a maximum value of the volume distribution, a summation of volumes of a portion of the first diffusion particles having diameters between D−2 μm and D+2 μm is about 40% to 80% of a total volume of the first diffusion particles.
1. An optical sheet, comprising:
a reflective polarizing film;
a first diffusing layer on the reflective polarizing film, the first diffusing layer including a resin and a plurality of first diffusion particles; and
a first adhesive layer between the reflective polarizing film and the first diffusing layer,
wherein, for a diameter D of the first diffusion particles corresponding to a maximum volume, a first percentage of a volume of the first diffusing layer having first diffusion particles with diameters between D−2 μm and D+2 μm is 40% to 80%,
wherein the first diffusing layer includes substantially 10 to 50 parts by weight of the diffusion particle based on 100 parts by weight of the resin,
wherein a thickness of the first adhesive layer is substantially 1 μm to 10 μm, and
wherein D is substantially 3 μm to 6 μm.
2. The optical sheet of claim 1 , wherein a minimum diameter of the first diffusion particles is 0.5 μm.
3. The optical sheet of claim 1 , wherein a maximum diameter of the first diffusion particles is 10 μm.
4. The optical sheet of claim 1 , wherein each of the first diffusion particles is one of a cavity and a bead.
5. The optical sheet of claim 1 , wherein the first diffusion particles are formed of a material selected from the group consisting of polymethylmethacrylate (PMMA), polystyrene, silicon, and a combination thereof.
6. The optical sheet of claim 1 , further comprising a second diffusing layer under the reflective polarizing film.
7. The optical sheet of claim 6 , further comprising a second adhesive layer between the reflective polarizing film and the second diffusing layer.
8. The optical sheet of claim 6 , wherein a second percentage of a volume of the second diffusing layer having second diffusion particles with diameters between D−2 μm and D+2 μm is within a predetermined range.
9. The optical sheet of claim 8 , wherein the second percentage is 40% to 80%.
10. The optical sheet of claim 1 , wherein the reflective polarizing film includes a first layer and a second layer that are alternately stacked and have different refractive indices.
11. A backlight unit, comprising:
a light source; and
an optical sheet on the light source, the optical sheet including
a reflective polarizing film,
a first diffusing layer on the reflective polarizing film, the first diffusing layer including a resin and a plurality of first diffusion particles, and
a first adhesive layer between the reflective polarizing film and the first diffusing layer,
wherein, for a diameter D of the first diffusion particles corresponding to a maximum volume, a first percentage of a volume of the first diffusing layer having first diffusion particles with diameters between D−2 μm and D+2 μm is within 40% to 80%,
wherein the first diffusing layer includes substantially 10 to 50 parts by weight of the diffusion particle based on 100 parts by weight of the resin,
wherein a thickness of the first adhesive layer is substantially 1 μm to 10 μm, and
wherein D is substantially 3 μm to 6 μm.
12. The backlight unit of claim 11 , further comprising a second diffusing layer under the reflective polarizing film.
13. The backlight unit of claim 12 , wherein a second percentage of a volume of the second diffusing layer having second diffusion particles with diameters between D−2 μm and D+2 μm is within a predetermined range.
14. The backlight unit of claim 13 , wherein the second percentage is 40% to 80%.
15. A liquid crystal display, comprising:
a light source;
an optical sheet on the light source, the optical sheet including
a reflective polarizing film,
a first diffusing layer on the reflective polarizing film, the first diffusing layer including a resin and a plurality of first diffusion particles, and
a first adhesive layer between the reflective polarizing film and the first diffusing layer; and
a liquid crystal display panel on the optical sheet,
wherein, for a diameter D of the first diffusion particles corresponding to a maximum volume, a first percentage of a volume of the first diffusing layer having first diffusion particles with diameters between D−2 μm and D+2 μm is within 40% to 80%,
wherein the first diffusing layer includes substantially 10 to 50 parts by weight of the diffusion particle based on 100 parts by weight of the resin,
wherein a thickness of the first adhesive layer is substantially 1 μm to 10 μm, and
wherein D is substantially 3 μm to 6 μm.
16. The liquid crystal display of claim 15 , further comprising a second diffusing layer under the reflective polarizing film.
17. The liquid crystal display of claim 16 , wherein a second percentage of a volume of the second diffusing layer having second diffusion particles with diameters between D−2 μm and D+2 μm is within a predetermined range.
18. The liquid crystal display of claim 17 , wherein the second percentage is 40% to 80%.