LIGHT-EMITTING UNIT AND LIGHT-EMITTING DEVICE INCLUDING THE SAME
A light-emitting unit and a light-emitting device including the same are provided. The light-emitting unit includes a substrate, a light-emitting element, a light-guiding element, and a light-adjusting element. The light-emitting element is disposed on the substrate. The light-guiding element has a top surface. The light-guiding element is disposed on the light-emitting element. The light-guiding element includes a central portion, a first portion, and a second portion. The first portion has a first roughness. The second portion has a second roughness. The light-adjusting layer is disposed on the top surface of the light-guiding element. The light-adjusting layer is disposed on the central portion of the light-guiding element. The first roughness of the first portion is lower than the second roughness of the second portion.
1 . A light-emitting unit, comprising:
a substrate;
a light-emitting element disposed on the substrate;
a light-guiding element having a top surface, disposed on the light-emitting element, and comprising:
a central portion;
a first portion having a first roughness; and
a second portion having a second roughness; and
a light-adjusting layer disposed on the top surface of the light-guiding element and disposed on the central portion of the light-guiding element,
wherein the first roughness of the first portion is lower than the second roughness of the second portion.
2 . The light-emitting unit as claimed in claim 1 , wherein a distance from a center of the first portion to a center of the central portion is smaller than a distance from a center of the second portion to the center of the central portion.
3 . The light-emitting unit as claimed in claim 1 , wherein the second portion is disposed on a virtual extending line of a diagonal line of the central portion.
4 . The light-emitting unit as claimed in claim 1 , wherein the first roughness and the second roughness are greater than or equal to 0.35 um.
5 . The light-emitting unit as claimed in claim 1 , wherein the first roughness is greater than or equal to 0.35 um and lower than or equal to 5 um.
6 . The light-emitting unit as claimed in claim 1 , wherein a ratio of the second roughness to the first roughness is greater than 2.
7 . The light-emitting unit as claimed in claim 1 , wherein the light-guiding element further comprises:
a bottom recess disposed on a bottom surface of the light-guiding element, wherein the light-emitting element is accommodated in the bottom recess.
8 . The light-emitting unit as claimed in claim 7 , wherein the bottom recess of the light-guiding element has a recess roughness, and the recess roughness is greater than the first roughness and the second roughness.
9 . The light-emitting unit as claimed in claim 8 , wherein a ratio of the recess roughness to the first roughness is greater than 3.
10 . The light-emitting unit as claimed in claim 7 , wherein the bottom recess of the light-guiding element is separated from the light-emitting element by a gap.
11 . The light-emitting unit as claimed in claim 1 , wherein the light-guiding element has a top recess.
12 . The light-emitting unit as claimed in claim 11 , further comprising:
a reflective material disposed on the top recess of the light-guiding element.
13 . The light-emitting unit as claimed in claim 11 , wherein the light-guiding element has a light-emitting area, the top recess surrounds the light-emitting area, and a ratio of a width of the light-emitting area to a width of the light-adjusting layer is greater than 1.5.
14 . The light-emitting unit as claimed in claim 11 , wherein the top recess has a depth, and the light-guiding element has a height, and a ratio of the depth to the height is less than 0.5.
15 . The light-emitting unit as claimed in claim 1 , wherein a ratio of a width of the light-adjusting layer to a width of the light-emitting element is greater than 2.
16 . The light-emitting unit as claimed in claim 1 , wherein the first portion is in direct contact with the central portion.
17 . The light-emitting unit as claimed in claim 1 , wherein the first portion surrounds the central portion.
18 . The light-emitting unit as claimed in claim 1 , wherein the light-guiding element further comprises:
a third portion disposed between the first portion and the second portion and having a third roughness between the first roughness and the second roughness.
19 . The light-emitting unit as claimed in claim 18 , wherein the light-guiding element further comprises:
a fourth portion disposed between the third portion and the second portion and having a fourth roughness between the third roughness and the second roughness.
20 . A light-emitting device comprising the light-emitting unit as claimed in claim 1 .