Planar light source with through hole and adjusting members

Patent metadata

Field	Value
Publication number	US-2023082182-A1
Application number	US-202218057006-A
Country	US
Kind code	A1
Filing date	Nov 18, 2022
Priority date	Jan 31, 2020
Publication date	Mar 16, 2023
Grant date	—

Abstract

A planar light source includes a light guide member having a through hole, a light source, a first light adjusting member, a second light adjusting member, and a light transmissive member. The first light adjusting member having reflectivity and transmissivity with respect to light from the light source is disposed on or above an upper face of the light source in the through hole. The second light adjusting member having reflectivity and transmissivity with respect to the light from the light source is disposed above and apart from the first light adjusting member. The first light transmissive member having a higher transmissivity with respect to the light from the light source than the transmissivities of the first and second light adjusting members is disposed between the first light adjusting member and the second light adjusting member, and between a lateral face of the light source and the light guide member.

First claim

What is claimed is:

1 . A planar light source comprising:
a light guide member having a first face, a second face opposing the first face, and a through hole passing through from the first face to the second face; a light source disposed in the through hole of the light guide member; a light adjusting member disposed on or above the light source in the through hole, and having a light reflectivity and a light transmissivity with respect to light emitted by the light source; a first light transmissive member disposed between a lateral face of the light source and the light guide member in the through hole, and having a higher light transmissivity with respect to the light emitted by the light source than the light transmissivity of the light adjusting member; a wiring substrate having an insulating base and a wiring layer; a light reflecting member disposed on the wiring substrate, the light reflecting member disposed between the wiring substrate and the second face of the light guide member, between the first light transmissive member in the through hole and the wiring substrate, and between the light source and the wiring substrate; and a joining member disposed through the light reflecting member and the insulating base in a region directly under the light source, the joining member connecting an electrode of the light source and the wiring layer, wherein a perimeter of the light adjusting member is positioned outward of an edge of the through hole.

2 . The planar light source according to claim 1 , wherein
the light source comprises: a light emitting element provided with the electrode on a lower face of the light emitting element; a second light transmissive member covering an upper face and a lateral face of the light emitting element; and a cover member covering the lower face of the light emitting element, and having a light reflectivity with respect to the light emitted by the light source.

3 . The planar light source according to claim 2 , wherein the second light transmissive member contains a phosphor.

4 . The planar light source according to claim 1 , wherein the light source is placed on an adhesive sheet disposed on the insulating base of the wiring substrate.

5 . The planar light source according to claim 1 , wherein grooves extend in a lattice pattern in the light guide member.

6 . The planar light source according to claim 5 , wherein the grooves extend through from the first face to the second face.

7 . The planar light source according to claim 1 , wherein the light reflecting member contains a large number of air bubbles.

8 . The planar light source according to claim 5 , wherein the light reflecting member is disposed between the grooves and the insulating base of the wiring substrate.

9 . The planar light source according to claim 1 , further comprising a phosphor sheet disposed above the first face of the light guide.

10 . The planar light source according to claim 2 , wherein the light source is placed on an adhesive sheet disposed on the insulating base of the wiring substrate.

11 . The planar light source according to claim 2 , wherein
grooves extend in a lattice pattern in the light guide member, and the grooves extend through from the first face to the second face.

12 . The planar light source according to claim 4 , wherein grooves extend in a lattice pattern in the light guide member.

13 . The planar light source according to claim 12 , wherein the grooves extend through from the first face to the second face.

14 . The planar light source according to claim 13 , wherein the light reflecting member contains a large number of air bubbles.

15 . The planar light source according to claim 12 , wherein the light reflecting member is disposed between the grooves and the insulating base of the wiring substrate.

16 . The planar light source according to claim 15 , wherein the light reflecting member contains a large number of air bubbles.

17 . The planar light source according to claim 1 , wherein
grooves extend in a lattice pattern in the light guide member, the grooves extend through from the first face to the second face, and the light reflecting member contains a large number of air bubbles.

18 . The planar light source according to claim 17 , wherein the light reflecting member is disposed between the grooves and the insulating base of the wiring substrate.

19 . The planar light source according to claim 14 , wherein the light reflecting member is disposed between the grooves and the insulating base of the wiring substrate.

20 . The planar light source according to claim 19 , further comprising a phosphor sheet disposed above the first face of the light guide.

Assignees

• Nichia Corp

Inventors

• Nakabayashi Takuya
• Hashimoto Toru

Classifications

• G02F1/133605

  including specially adapted reflectors · CPC title

• G02B6/0073

  Light emitting diode [LED] · CPC title

• G02B6/0021

  for housing at least a part of the light source, e.g. by forming holes or recesses · CPC title

• G02F1/133606 Primary

  including a specially adapted diffusing, scattering or light controlling members · CPC title

• G02F1/133611

  including means for improving the brightness uniformity · CPC title