Light emitting module and planar light source

Patent metadata

Field	Value
Publication number	US-12001044-B2
Application number	US-202218046907-A
Country	US
Kind code	B2
Filing date	Oct 14, 2022
Priority date	Oct 15, 2021
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

A light emitting module includes a light source, a light guide member, and first and second light reflective members. The light guide member is configured to transmit light from the light source. The light guide member having an upper surface and a lower surface opposite to the upper surface. The first light reflective member is arranged on a lower surface side of the light guide member. The first light reflective member has a lower surface. The first light reflective member includes a first resin, and a first reflective body having a refractive index higher than a refractive index of the first resin. The second light reflective member is arranged on a lower surface side of the first light reflective member. The second light reflective member includes a second resin, and a second reflective body having a refractive index lower than a refractive index of the second resin.

First claim

What is claimed is:

1. A light emitting module comprising:
a light source;
a light guide member configured to transmit light from the light source, the light guide member having an upper surface and a lower surface opposite to the upper surface, the light guide member defining a hole with the light source being arranged inside the hole;
a first light reflective member arranged on a lower surface side of the light guide member, the first light reflective member having a lower surface, the first light reflective member including
a first resin, and
a first reflective body having a refractive index higher than a refractive index of the first resin; and

a second light reflective member arranged on a lower surface side of the first light reflective member, the second light reflective member including
a second resin, and
a second reflective body having a refractive index lower than a refractive index of the second resin.

2. The light emitting module according to claim 1 , wherein the first reflective body is titanium oxide.

3. The light emitting module according to claim 1 , wherein the second reflective body is a gas.

4. The light emitting module according to claim 1 , wherein
the refractive index of the first resin is lower than a refractive index of the light guide member.

5. The light emitting module according to claim 1 , wherein
the first resin is one of an acrylic resin, a silicone resin, a urethane resin, and an epoxy resin.

6. The light emitting module according to claim 1 , wherein
the second resin is one of a polyethylene terephthalate resin, an olefin resin, an acrylic resin, a silicone resin, a urethane resin, and an epoxy resin.

7. The light emitting module according to claim 1 , wherein
a thickness of the second light reflective member is greater than a thickness of the first light reflective member.

8. The light emitting module according to claim 1 , wherein
in a plan view, the first light reflective member is positioned between the light source and a portion of an outer edge of the light guide member farthest from the light source.

9. The light emitting module according to claim 1 , wherein
the first light reflective member faces the lower surface of the light guide member and a lower surface of the light source.

10. The light emitting module according to claim 1 , wherein
the second light reflective member faces an entire lower surface of the first light reflective member.

11. The light emitting module according to claim 1 , wherein
the hole is a through hole extending from the upper surface to the lower surface of the light guide member.

12. The light emitting module according to claim 1 , further comprising
a third light reflective member arranged on a lower surface side of the second light reflective member, the third light reflective member including
a third resin, and
a third reflective body having a higher refractive index than the third resin.

13. The light emitting module according to claim 12 , wherein
a concentration of the third reflective body in the third light reflective member is higher than a concentration of the first reflective body in the first light reflective member.

14. The light emitting module according to claim 12 , further comprising
a fourth light reflective member arranged on an upper side of the light source, the fourth light reflective member including
a fourth resin, and
a fourth reflective body having a higher refractive index than the fourth resin.

15. The light emitting module according to claim 14 , wherein
a concentration of the first reflective body in the first light reflective member is lower than a concentration of the fourth reflective body in the fourth light reflective member.

16. The light emitting module according to claim 1 , wherein
the first light reflective member includes a plurality of light reflective particles constituting the first reflective body, the light reflective particles being dispersed in the first resin.

17. The light emitting module according to claim 1 , wherein
the light guide member further defines a light guide hole arranged between the hole and an outer edge of the light guide member in a plan view.

18. A planar light source comprising:
the light emitting module according to claim 1 ; and
a support member, wherein
the first light reflective member and the second light reflective member are arranged between the support member and the light guide member.

19. The light emitting module according to claim 1 , further comprising
an additional light reflective member arranged on one of
a lower surface side of the second light reflective member, and
an upper side of the light source,

the additional light reflective member including
a resin material, and
an additional reflective body having a higher refractive index than the resin material.

20. The light emitting module according to claim 19 , wherein
a concentration of the additional reflective body in the additional light reflective member is higher than a concentration of the first reflective body in the first light reflective member.

Assignees

• Nichia Corp

Inventors

• Nakabayashi Takuya
• Iwakura Daisuke
• Bando Yoichi
• Shinomiya Yasunori
• Yoshinaga Satoshi

Classifications

• G02B6/0045 Primary

  by shaping at least a portion of the light guide · CPC title

• G02B6/0055

  Reflecting element, sheet or layer · CPC title

• G02B6/0021 Primary

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

• G02B6/0031

  Reflecting element, sheet or layer · CPC title

• G02B6/0083

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