# US 10,371,353 B2 · Light-emitting device

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- Number: US 10,371,353 B2
- Document ID: US10371353B2
- Status: Granted
- Kind: B2
- Application number: 15/285,595
- Filed: 2016-10-05
- Published: 2017-04-13
- Granted: 2019-08-06
- Earliest claimed: 2015-10-13
- Assignees: Enplas Corporation
- Applicants: Enplas Corporation
- Inventors: Tomohiro Saito
- Web page: https://patentgrep.com/patent/US10371353B2

## CPC

- F21V 5/045: {the lens having discontinuous faces, e.g. Fresnel lenses}
- F21V 7/00: Reflectors for light sources (characterised by cooling arrangements F21V29/505)
- F21V 13/04: the elements being reflectors and refractors {(for vehicle rear lights F21S43/40)}
- G02B 3/00: Simple or compound lenses
- G02B 3/08: with discontinuous faces, e.g. Fresnel lens {(diffractive Fresnel lenses G02B5/1876)}
- G02B 19/0014: {at least one surface having optical power}
- G02B 19/0061: {the light source comprising a LED}
- G03B 15/03: Combinations of cameras with lighting apparatus; Flash units
- G03B 15/05: Combinations of cameras with electronic flash apparatus; Electronic flash units
- F21Y 2115/10: Light-emitting diodes [LED]
- G03B 2215/0592: installed in front of light emitter
- F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D)
- F21Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED

## Abstract

A light-emitting device includes: a light emitting element; and a light flux controlling member configured to allow incidence of light from the light emitting element and emit light incident on the light flux controlling member. The light flux controlling member includes an incidence region and an emission region. The incidence region includes a fresnel lens part having a plurality of projected lines formed to surround a central axis of the light flux controlling member. The projected line includes an incidence surface configured to allow incidence of the light from the light emitting element, and a reflecting surface paired with the incidence surface and configured to reflect the light incident on the incidence surface toward the emission region. An angle between the incidence surface and a line parallel to the central axis is greater than an angle between the reflecting surface and a line parallel to the central axis.

## Claims

### Claim 1

A light-emitting device comprising:
a light emitting element; and
a light flux controlling member disposed to cover the light emitting element such that a central axis of the light flux controlling member is parallel to an optical axis of the light emitting element, the light flux controlling member being configured to allow incidence of light emitted from the light emitting element and emit light incident on the light flux controlling member while controlling a light distribution of the light incident on the light flux controlling member, wherein:
the light flux controlling member includes an incidence region and an emission region, the incidence region being disposed on the light emitting element side and configured to allow the incidence of the light emitted from the light emitting element, the emission region being disposed on a side opposite to the incidence region of the light flux controlling member and configured to emit the light incident on the incidence region,
the incidence region includes a fresnel lens part having a plurality of projected lines which are similar to each other in plan view and are formed to surround the central axis,
at least a part of the fresnel lens part faces at least a part of a light emitting surface of the light emitting element,
a projected line of the plurality of projected lines includes an incidence surface configured to allow incidence of a part of the light emitted from the light emitting element, and a reflecting surface paired with the incidence surface and configured to reflect the light incident on the incidence surface towards the emission region,
the incidence surface of the projected line directs, mainly toward the reflecting surface, light that is incident on the incidence surface of the projected line after being emitted from a light emission center of the light emitting element,
the reflecting surface of the projected line reflects, toward the emission region side, at least the light that is incident on the incidence surface after being emitted from the light emission center of the light emitting element such that the light approaches the optical axis of the light emitting element,
the reflecting surface of the projected line allows incidence of light emitted from the light emitting element in a direction parallel to the optical axis, and
an angle between the incidence surface of the projected line and a line parallel to the central axis is greater than an angle between the reflecting surface of the projected line and a line parallel to the central axis.

### Claim 2 (depends on 1)

The light-emitting device according to claim 1, wherein the fresnel lens part includes a plurality of annular projected lines concentrically formed around the central axis of the light flux controlling member.

### Claim 3 (depends on 1)

The light-emitting device according to claim 1, wherein the incidence region further includes a refraction part disposed to intersect with the optical axis of the light emitting element and configured to allow incidence of a part of the light emitted from the light emitting element.

### Claim 4 (depends on 2)

The light-emitting device according to claim 2, wherein the incidence region further includes a refraction part disposed to intersect with the optical axis of the light emitting element and configured to allow incidence of a part of the light emitted from the light emitting element.