Light source assembly and display device

1. A light source assembly, comprising: a first substrate and a second substrate arranged opposite to each other; a waveguide layer arranged between the first substrate and the second substrate; and a side-incident collimated light source arranged on a side of the waveguide layer, wherein:

a refractive index of the waveguide layer is higher than a refractive index of the first substrate, and a refractive index of the second substrate respectively; and

light of the side-incident collimated light source is incident onto a side of the waveguide layer at a preset angle, wherein the incident light is totally reflected only at an interface between the first substrate and the waveguide layer;

wherein the refractive index of the first substrate is equal to the refractive index of the second substrate, and the light source assembly further comprises a grating coupling structure arranged between the waveguide layer and the first substrate, wherein:

the grating coupling structure comprises a plurality of grating bars arranged at an interval, and grating gaps between adjacent two of the grating bars, wherein a refractive index of a grating bar is higher than the refractive index of the first substrate, and wherein the incident light is refracted out of the waveguide layer from an interface between the second substrate and the waveguide layer;

the first substrate overlies the grating gaps; and

a width of each of the plurality of grating bars is the same, a thickness of each of the plurality of grating bars is the same, and the thickness of each of the plurality of grating bars is no more than the width of each of the plurality of the grating bars.

2. The light source assembly according to claim 1 , wherein a material of the grating coupling structure is the same as that of the waveguide layer.

3. The light source assembly according to claim 2 , wherein the grating coupling structure and the waveguide layer are formed in an integral structure.

4. The light source assembly according to claim 1 , wherein a grating periodicity of the grating coupling structure is more than 1000 nm, and a duty ratio of the grating coupling structure ranges from 0.1 to 0.9.

5. The light source assembly according to claim 1 , wherein a thickness of the grating coupling structure ranges from 100 nm to 1.5 μm.

6. The light source assembly according to claim 1 , wherein a material of the waveguide layer comprises at least one of resin, glass, ITO, or Si 3 N 4 .

7. The light source assembly according to claim 1 , wherein a thickness of the waveguide layer ranges from 100 nm to 100 μm.

8. The light source assembly according to claim 1 , wherein light from the collimated light source is light into which monochromatic light emitted from at least three types of monochromatic laser chips is mixed; or the light from the collimated light source is light into which monochromatic light emitted from at least three types of monochromatic light-emitting diode chips is mixed after a collimating structure; or the light from the collimated light source is white light, emitted by a white light-emitting diode chip, which is collimated by a collimating structure; or the light from the collimated light source is light emitted by a cold cathode fluorescent lamp bar and collimated by a collimating structure.

9. A display device, comprising a display panel, and a front light source located at a light exiting side of the display panel, wherein the front light source is the light source assembly according to claim 1 ; and

the second substrate of the light source assembly is located on a side thereof proximate to the display panel.

10. A display device, comprising a liquid crystal display panel, and a backlight source configured to provide a light source for the liquid crystal display panel, wherein the backlight source is the light source assembly according to claim 1 ; and

the second substrate of the light source assembly is located on a side thereof proximate to the liquid crystal display panel.

11. A light source assembly, comprising: a first substrate and a second substrate arranged opposite to each other; a waveguide layer arranged between the first substrate and the second substrate; and a side-incident collimated light source arranged on a side of the waveguide layer, wherein:

a refractive index of the waveguide layer is higher than a refractive index of the first substrate, and a refractive index of the second substrate respectively; and

light of the side-incident collimated light source is incident onto a side of the waveguide layer at a preset angle, wherein the incident light is totally reflected only at an interface between the first substrate and the waveguide layer;

wherein the refractive index of the first substrate is equal to the refractive index of the second substrate, and the light source assembly further comprises a grating coupling structure arranged between the waveguide layer and the first substrate, wherein:

the grating coupling structure comprises a plurality of grating bars arranged at an interval, and grating gaps between adjacent two of the grating bars, wherein a refractive index of a grating bar is higher than the refractive index of the first substrate, and wherein the incident light is refracted out of the waveguide layer from an interface between the second substrate and the waveguide layer;

the first substrate overlies the grating gaps;

a width of each of the plurality of grating bars is the same, a thickness of each of the plurality of grating bars is the same, and the thickness of each of the plurality of grating bars is no more than the width of each of the plurality of the grating bars;

a thickness of the grating coupling structure ranges from 100 nm to 1.5 μm;

a thickness of the waveguide layer ranges from 100 nm to 100 μm; and

light from the collimated light source is light into which monochromatic light emitted from at least three types of monochromatic laser chips is mixed; or the light from the collimated light source is light into which monochromatic light emitted from at least three types of monochromatic light-emitting diode chips is mixed after a collimating structure; or the light from the collimated light source is white light, emitted by a white light-emitting diode chip, which is collimated by a collimating structure; or the light from the collimated light source is light emitted by a cold cathode fluorescent lamp bar and collimated by a collimating structure.

12. The light source assembly according to claim 11 , wherein a material of the grating coupling structure is the same as that of the waveguide layer.

13. The light source assembly according to claim 12 , wherein the grating coupling structure and the waveguide layer are formed in an integral structure.

14. The light source assembly according to claim 11 , wherein a grating periodicity of the grating coupling structure is more than 1000 nm, and a duty ratio of the grating coupling structure ranges from 0.1 to 0.9.

15. The light source assembly according to claim 11 , wherein a material of the waveguide layer comprises at least one of resin, glass, ITO, or Si 3 N 4 .

16. A display device, comprising a display panel, and a front light source located at a light exiting side of the display panel, wherein the front light source is the light source assembly according to claim 11 ; and

the second substrate of the light source assembly is located on a side thereof proximate to the display panel.

17. A display device, comprising a liquid crystal display panel, and a backlight source configured to provide a light source for the liquid crystal display panel, wherein the backlight source is the light source assembly according to claim 11 ; and

the second substrate of the light source assembly is located on a side thereof proximate to the liquid crystal display panel.