# US 11,306,878 B2 · Smart-home device light rings with scalloped transmissive sections for uniform output

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- Number: US 11,306,878 B2
- Document ID: US11306878B2
- Status: Granted
- Kind: B2
- Application number: 17/170,235
- Filed: 2021-02-08
- Published: 2021-06-03
- Granted: 2022-04-19
- Earliest claimed: 2017-12-31
- Assignees: Google Inc.
- Applicants: Google LLC
- Inventors: Mark Kraz; Amber Volmering; Bryan Macomber; Jacobi Grillo; Adam Kilgore
- Web page: https://patentgrep.com/patent/US11306878B2

## CPC

- F21K 9/61: using light guides
- F21K 9/237: Details of housings or cases, i.e. the parts between the light-generating element and the bases; Arrangement of components within housings or cases (F21K9/238 takes precedence)
- F21K 9/62: using mixing chambers, e.g. housings with reflective walls
- F21K 9/65: specially adapted for changing the characteristics or the distribution of the light, e.g. by adjustment of parts
- F21V 3/0625: {the material diffusing light, e.g. translucent plastics}
- F21V 5/004: {using microlenses}
- F21V 5/046: {the lens having a rotationally symmetrical shape about an axis for transmitting light in a direction mainly perpendicular to this axis, e.g. ring or annular lens with light source disposed inside the ring}
- F21V 13/12: Combinations of only three kinds of elements
- F21V 14/06: by movement of refractors {(in vehicle head lamps F21S41/635)}
- F21V 33/00: Structural combinations of lighting devices with other articles, not otherwise provided for
- G02B 6/0021: {for housing at least a part of the light source, e.g. by forming holes or recesses}
- G02B 6/005: {provided by one optical element, or plurality thereof, placed on the light output side of the light guide}
- G02B 6/0051: {Diffusing sheet or layer}
- G02B 6/0068: {Arrangements of plural sources, e.g. multi-colour light sources}
- H04N 7/183: {for receiving images from a single remote source}
- H04N 23/56: provided with illuminating means
- H05B 47/19: via wireless transmission
- H05B 47/1965: {using handheld communication devices}
- F21Y 2103/33: annular
- F21Y 2115/10: Light-emitting diodes [LED]
- G02B 6/0036: {2-D arrangement of prisms, protrusions, indentations or roughened surfaces}
- G02B 6/0046: {Tapered light guide, e.g. wedge-shaped light guide}
- G02B 6/009: {of the light source in the package (G02B6/0021 takes precedence)}
- Y02B 20/40: Control techniques providing energy savings, e.g. smart controller or presence detection
- F21K: NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
- 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
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION
- H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
- 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
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

A light ring assembly for a smart-home device may include a plurality of light-emitting diodes (LEDs) and a light guide, where the light guide may include a plurality of cutouts that receive the plurality of LEDs, and a plurality of transmissive sections between the plurality of cutouts where a thickness of the transmissive sections tapers as the transmissive sections extend away from the plurality of cutouts. The light ring assembly may also include an output surface that receives light emitted from the plurality of LEDs through the plurality of transmissive sections, where the output surface is substantially circular.

## Claims

### Claim 1

A light guide for a smart-home device, the light guide having a substantially cylindrical shape and comprising: a transparent middle layer comprising a plurality of cutouts configured to receive a plurality of light-emitting diodes (LEDs); a plurality of transmissive sections that extend away from the plurality of cutouts, wherein the plurality of transmissive sections have scalloped profiles that radiate outward from the plurality of cutouts, such that light from the LEDs is gradually reflected as it travels through the middle layer towards a substantially circular output surface of middle layer; and the substantially circular output surface that receives the light received through the plurality of cutouts through the plurality of transmissive sections.

### Claim 2 (depends on 1)

The light guide of claim 1, wherein the light guide comprises a cylindrical shape with a bottom substantially circular surface and a top substantially circular surface.

### Claim 3 (depends on 2)

The light guide of claim 2, wherein the plurality of cutouts are evenly spaced around the bottom substantially circular surface of the cylindrical shape.

### Claim 4 (depends on 3)

The light guide of claim 3, wherein the plurality of cutouts extend into the bottom substantially circular surface of the cylindrical shape.

### Claim 5 (depends on 2)

The light guide of claim 2, wherein the substantially circular output surface comprises the top substantially circular surface of the cylindrical shape.

### Claim 6 (depends on 1)

The light guide of claim 1, wherein the plurality of transmissive sections comprise thicknesses that taper as the plurality of transmissive sections extend away from the plurality of cutouts.

### Claim 7 (depends on 1)

The light guide of claim 1, wherein a thinnest portion of the plurality of transmissive sections is located directly above the plurality of cutouts adjacent to the substantially circular output surface.

### Claim 8 (depends on 1)

The light guide of claim 1, wherein a thickest portion of the plurality of transmissive sections is located directly above the plurality of cutouts adjacent to the plurality of cutouts.

### Claim 9 (depends on 1)

The light guide of claim 1, wherein a tapering of the plurality of transmissive sections decreases as the plurality of transmissive sections radiate outward from lines extending from directly above the plurality of cutouts.

### Claim 10 (depends on 1)

The light guide of claim 1, wherein the scalloped profiles of the plurality of transmissive sections gradually reflect light as it travels upwards through the light guide to uniformly distribute the light out of the substantially circular output surface.

### Claim 11

A method of assembling a uniform light ring in a smart-home device, the method comprising: mounting a plurality of LEDs (light emitting diodes) on a printed circuit board; placing a light guide having a cylindrical shape on top of the printed circuit board, wherein the plurality of LEDs are received by a plurality of cutouts in a transparent middle layer of the light guide of the light ring, and wherein the transparent middle layer of the light guide comprises a plurality of transmissive sections that extend away from the plurality of cutouts, wherein the plurality of transmissive sections have scalloped profiles that radiate outward from the plurality of cutouts, such that light from the LEDs is gradually reflected as it travels through the middle layer towards a substantially circular output surface of middle layer.

### Claim 12 (depends on 11)

The method of claim 11, further comprising casting a middle layer of the light guide from a transparent plastic, wherein the middle layer comprises the plurality of cutouts and the plurality of transmissive sections.

### Claim 13 (depends on 12)

The method of claim 12, further comprising, after casting the middle portion of the light guide, casting an inside layer and an outside layer around the middle layer using a 2-shot process.

### Claim 14 (depends on 13)

The method of claim 13, wherein the inside layer and the outside layer expose a circular ring along a bottom of the middle layer comprising the plurality of cutouts, and a ring around a top of the middle layer that acts as a substantially circular output surface for the light guide.

### Claim 15

A light ring assembly for a smart-home device, the light ring assembly comprising: a light guide having a cylindrical shape and comprising an inside layer comprising a first opaque material; an outside layer comprising a second opaque material; and a middle layer comprising a transparent material, wherein the transparent material of the middle layer comprises: a plurality of cutouts configured to receive a plurality of light-emitting diodes (LEDs); and a plurality of transmissive sections that extend away from the plurality of cutouts, wherein the plurality of transmissive sections have scalloped profiles that radiate outward from the plurality of cutouts, such that light from the LEDs is gradually reflected as it travels through the middle layer towards a substantially circular output surface of middle layer.

### Claim 16 (depends on 15)

The light ring assembly of claim 15, wherein the first opaque material comprises a cast from an opaque plastic.

### Claim 17 (depends on 15)

The light ring assembly of claim 15, wherein the transparent material comprises a cast from a transparent plastic.

### Claim 18 (depends on 15)

The light ring assembly of claim 15, wherein the inside layer and the outside layer form a light mask around the middle layer.

### Claim 19 (depends on 15)

The light ring assembly of claim 15, wherein
the inside layer and the outside layer expose a circular ring along a bottom of the middle layer that comprises the plurality of cutouts; and
the inside layer on the outside layer expose a substantially circular output surface along a top of the middle layer.

### Claim 20 (depends on 15)

The light ring assembly of claim 15, further comprising a printed circuit board, wherein the plurality of LEDs are mounted to the printed circuit board and the middle layer is placed adjacent to the printed circuit board such that the plurality of LEDs fit inside the plurality of cutouts.