Lens, light source device, backlight unit, and electronic device

Patent metadata

Field	Value
Publication number	US-11467446-B2
Application number	US-202117338605-A
Country	US
Kind code	B2
Filing date	Jun 3, 2021
Priority date	Jul 21, 2017
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

The present disclosure relates to a light diffusion characteristic and a light reflection characteristic, and a light source device, a backlight unit, and an electronic device that include the lens. By causing the light emitted from the light source of the light source device to have both light diffusibility and light directivity using the lens including a lower layer portion having a light diffusion characteristic and an upper layer portion having a light reflection characteristic, it is possible to improve a light emission characteristic of the light source device, and when an optical gap is reduced due to the thickness reduction of the backlight unit, the image quality of the backlight unit can be improved.

First claim

What is claimed is:

1. A lens for a light source device, the lens comprising:
a lower layer portion having a light-incident portion configured such that light emitted from a light source is incident thereon; and
an upper layer portion positioned on the lower layer portion, the upper layer portion having a reflective portion inclined inward or concave on a part or whole of a top surface,
wherein an outer surface of the lower layer portion of the lens has a convex shape and an outer surface of the upper layer portion of the lens has a concave shape,
wherein based on an axis perpendicular to a bottom of the lens, a curvature of the outer surface of the lower layer portion of the lens decreases in absolute value from the bottom to the top of the lens and a curvature of the outer surface of the upper layer portion of the lens increases in absolute value from the bottom to the top of the lens,
wherein the lower layer portion is configured to directly refract the light incident through the light-incident portion on the outer surface of the lower layer portion so as to diffuse the light outward, and the upper layer portion is configured to reflect at least a part of the light incident through the light-incident portion from the reflective surface to send out the light from the outer surface of the upper layer portion, and
wherein the light-incident portion has a concave portion in which the light source is disposed.

2. The lens of claim 1 , wherein the light-incident portion is provided on a bottom surface of the lens.

3. The lens of claim 1 , wherein a lowest point of the reflective portion is located higher than a point where the outer surface of the lower layer portion and the outer surface of the upper layer portion meet.

4. The lens of claim 3 , wherein the point is at a middle point of the lens.

5. The lens of claim 1 , wherein the upper layer portion is a first material having a first refractive index, and the lower layer portion is a second material having a second refractive index.

6. The lens of claim 5 , wherein the first material and the second material is the different from each other.

7. The lens of claim 6 , wherein the first refractive index and the second refractive index is the same, or the first refractive index and the second refractive index is different from each other.

8. A backlight unit comprising:
a light source;
a lens;
a diffuser plate disposed on the lens and spaced apart from the lens; and
a cover bottom accommodating the light source, the lens, and the diffuser plate,
wherein the lens comprising:
a lower layer portion having a light-incident portion configured such that light emitted from the light source is incident thereon; and
an upper layer portion positioned on the lower layer portion, the upper layer portion having a reflective portion inclined inward or concave on a part or whole of a top surface,
wherein an outer surface of the lower layer portion of the lens has a convex shape and an outer surface of the upper layer portion of the lens has a concave shape,
wherein based on an axis perpendicular to a bottom of the lens, a curvature of the outer surface of the lower layer portion of the lens decreases in absolute value from the bottom to the top of the lens and a curvature of the outer surface of the upper layer portion of the lens increases in absolute value from the bottom to the top of the lens,
wherein the lower layer portion is configured to directly refract the light incident through the light-incident portion on the outer surface of the lower layer portion so as to diffuse the light outward, and the upper layer portion is configured to reflect at least a part of the light incident through the light-incident portion from the reflective surface to send out the light from the outer surface of the upper layer portion, and
wherein the light-incident portion has a concave portion in which the light source is disposed.

9. The backlight unit of claim 8 , wherein the light-incident portion is provided on a bottom surface of the lens.

10. The backlight unit of claim 8 , wherein a lowest point of the reflective portion is located higher than a point where the outer surface of the lower layer portion and the outer surface of the upper layer portion meet.

11. The backlight unit of claim 10 , wherein the point is at a middle point of the lens.

12. The backlight unit of claim 8 , wherein the upper layer portion is a first material having a first refractive index, and the lower layer portion is a second material having a second refractive index.

13. The backlight unit of claim 12 , wherein the first material and the second material is the different from each other.

14. The backlight unit of claim 13 , wherein the first refractive index and the second refractive index is the same, or the first refractive index and the second refractive index is different from each other.

Assignees

• Lg Display Co Ltd

Inventors

• Park Kiduck
• Kim Younghyun

Classifications

• G02B19/0061

  the light source comprising a LED · CPC title

• G02B19/0028

  refractive and reflective surfaces, e.g. non-imaging catadioptric systems · CPC title

• G02F1/133603 Primary

  with LEDs · CPC title

• G02F1/133607

  the light controlling member including light directing or refracting elements, e.g. prisms or lenses · CPC title

• G02F1/133614

  using photoluminescence, e.g. phosphors illuminated by UV or blue light · CPC title