Planar light source and method of manufacturing planar light source

Patent metadata

Field	Value
Publication number	US-11480725-B2
Application number	US-202117338411-A
Country	US
Kind code	B2
Filing date	Jun 3, 2021
Priority date	Jun 4, 2020
Publication date	Oct 25, 2022
Grant date	Oct 25, 2022

Abstract

A planar light source includes: a light guide plate including: a first principal face, a second principal face located opposite the first principal face, and a plurality of through holes that are open at the first principal face and the second principal face; a plurality of light sources, wherein at least one of the light sources is located in the through holes of the light guide plate; a wiring substrate on which the plurality of light sources are located; a first light transmissive member located in a first of the through holes so as to cover at least a portion of a lateral face of the at least one light source located in the first through hole; and a second light transmissive member located in the first through hole so as to cover at least an upper face of the first light transmissive member.

First claim

What is claimed is:

1. A planar light source comprising:
a light guide plate comprising:
a first principal face,
a second principal face located opposite the first principal face,
a plurality of unit regions that are arranged in one dimension or two dimensions, and
a plurality of lateral faces extending from the first principal face to the second principal face and defining a plurality of through holes that are open at the first principal face and the second principal face, wherein at least one of the through holes is located in each of the unit regions;

a plurality of light sources, wherein at least one of the light sources is located in each of the through holes of the light guide plate;
a wiring substrate on which the plurality of light sources are located, the wiring substrate being positioned on a second principal face side of the light guide plate;
a first light transmissive member located in a first of the through holes so as to cover at least a portion of a lateral face of the at least one light source located in the first through hole and contact a first of the lateral faces that defines the first through hole; and
a second light transmissive member located in the first through hole so as to cover at least an upper face of the first light transmissive member and contact the first lateral face that defines the first through hole.

2. The planar light source according to claim 1 , wherein:
the upper face of the first light transmissive member comprises a recessed part recessed towards the second principal face of the light guide plate, and
a lower face of the second light transmissive member comprises a first protrusion part that is in contact with the upper face of the first light transmissive member and protrudes towards the second principal face side of the light guide plate.

3. The planar light source according to claim 2 , further comprising:
a phosphor that is localized on a lower face side of the second light transmissive member.

4. The planar light source according to claim 1 , wherein:
the second light transmissive member further covers an upper face of the at least one light source located in the first through hole.

5. The planar light source according to claim 4 , further comprising:
a light shielding member located on an upper face of the second light transmissive member.

6. The planar light source according to claim 1 , wherein:
in at least one of the unit regions, the first light transmissive member entirely covers lateral faces of the at least one light source located in the first through hole.

7. The planar light source according to claim 1 , further comprising:
a light reflecting sheet positioned between the wiring substrate and the light guide plate, and covering the second principal face of the light guide plate.

8. The planar light source according to claim 1 , wherein:
the light guide plate comprises a plurality of sectioning grooves that are open at the first principal face and that, in a top view, surround the unit regions along perimeters of the unit regions, and
a plurality of light reflecting members are located in the sectioning grooves.

Assignees

• Nichia Corp

Inventors

• Kasai Daisuke

Classifications

• G02B6/0023

  provided by one optical element, or plurality thereof, placed between the light guide and the light source, or around the light source · CPC title

• F21Y2105/16

  square or rectangular, e.g. for light panels · CPC title

• G02F1/133603

  with LEDs · CPC title

• G02F1/133614

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

• G02B6/0083 Primary

  Details of electrical connections of light sources to drivers, circuit boards, or the like · CPC title