Lighting component including switchable diffuser

• US 10,598,349 B2
• Filed: 10/22/2015
• Issued: 03/24/2020
• Est. Priority Date: 11/07/2014
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Du, Guanglei, Wheatley, John A., Brott, Robert L.
• Primary Examiner(s): Fallahkhair, Arman B
• Application Number:
  US15/514,861
• Publication Number:
  US 20170241622A1
• Time in Patent Office: 1,615 Days
• CPC Class Codes: F21K 9/69 Details of refractors forming part of the light source
• CPC Class Codes: F21V 14/003 by interposition of elements with electrically controlled variable light transmissivity, e.g. liquid crystal elements or electrochromic devices
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21V 7/22 characterised by materials, surface treatments or coatings, e.g. dichroic reflectors
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]

Abstract

A lighting component including an optical volume and a switchable diffuser disposed at least partially within the optical volume is described. The optical volume includes a light injection region, at least one reflective or transflective outer major surface, and an output major surface. The at least one reflective or transflective outer major surface defines opposing boundaries of the optical volume. The output major surface is adjacent one or more distal edges of the at least one reflective or transflective outer major surface. The switchable diffuser has at least a first state and a second state. The switchable diffuser may have a surface normal that is not parallel to an optical axis of the optical volume. The at least one reflective or transflective outer major surface may have a spatially varying reflective property.

Claims

1. A lighting component comprising:

an optical volume including a light injection region, at least one reflective or transflective outer major surface defined by a film reflecting at least 10 percent of a light energy incident on the at least one reflective or transflective outer major surface, and an output major surface, the output major surface adjacent one or more distal edges of the at least one reflective or transflective outer major surface; and

a first switchable diffuser disposed at least partially within the optical volume, the first switchable diffuser having at least a first state and a second state, the first state characterized by a first haze and the second state characterized by a second haze different from the first haze, wherein at least a portion of the first switchable diffuser has a surface normal that is not parallel to an optical axis of the optical volume; and

wherein the at least one reflective or transflective outer major surface defines opposing boundaries of the optical volume, wherein the first switchable diffuser includes a plurality of independently addressable regions, each region independently capable of being in the first state or in the second state; and

wherein the at least one reflective or transflective outer major surface includes a plurality of zones having a reflective property that varies discretely from zone to zone by spatial variation in a perforation density of the film, the zones being in one-to-one correspondence with the regions such that when each region is in the first state and for each zone, light injected into the light injection region is incident on the zone after being transmitted through a region of the first switchable diffuser corresponding to the zone.

2. The lighting component of claim 1, wherein the optical volume has boundaries which substantially converge or diverge but not both from the light injection region to the output major surface.

3. The lighting component of claim 1, wherein the first switchable diffuser includes smectic A liquid crystal.

4. The lighting component of claim 1, further comprising a light source having a plurality of LEDs, wherein the independently addressable regions of the first switchable diffuser are registered with the plurality of LEDs.

5. The lighting component of claim 1, further comprising a segmented layer adjacent the first switchable diffuser, wherein segments of the segmented layer are registered with the independently addressable regions of the first switchable diffuser.

6. The lighting component of claim 1 further comprising at least one sensor and a controller, wherein the controller is configured to receive at least one input from the at least one sensor and to provide a control signal to the first switchable diffuser.

7. The lighting component of claim 1, wherein the at least one reflective or transflective outer major surface includes a first axially symmetric surface extending from the light injection region to the output major surface and includes a second axially symmetric surface physically separate from the first axially symmetric surface and disposed adjacent the output major surface opposite the light injection region.

8. The lighting component of claim 1, wherein each surface in the at least one reflective or transflective outer major surface is a surface of a reflective or transflective film.

9. A lighting component comprising:

an optical volume including a light injection region, at least one reflective or transflective outer major surface defined by a film reflecting at least 10 percent of a light energy incident on the at least one reflective or transflective outer major surface, and an output major surface, the output major surface adjacent one or more distal edges of the at least one reflective or transflective outer major surface; and

a first switchable diffuser disposed at least partially within the optical volume, the first switchable diffuser having at least a first state and a second state, the first state characterized by a first haze and the second state characterized by a second haze different from the first haze, wherein the at least one reflective or transflective outer major surface defines opposing boundaries of the optical volume, wherein the first switchable diffuser includes a plurality of independently addressable regions, each region independently capable of being in the first state or in the second state; and

wherein the at least one reflective or transflective outer major surface includes a plurality of zones having a reflective property that varies discretely from zone to zone by spatial variation in a perforation density of the film, the zones being in one-to-one correspondence with the regions such that when each region is in the first state and for each zone, light injected into the light injection region is incident on the zone after being transmitted through a region of the first switchable diffuser corresponding to the zone.

10. The lighting component of claim 9, wherein the reflective property includes one or more of reflectivity of unpolarized light in a first wavelength band, reflectivity of polarized light having a first polarization state in the first wavelength band, a ratio of diffuse to specular reflectivity of unpolarized light in the first wavelength band, and a ratio of diffuse to specular reflectivity of polarized light having the first polarization state in the first wavelength band.

11. The lighting component of claim 9 further comprising at least one sensor and a controller, wherein the controller is configured to receive at least one input from the at least one sensor and to provide a control signal to the first switchable diffuser.

12. A lighting component comprising:

an optical volume having at least one reflective or transflective outer major surface defined by a film reflecting at least 10 percent of a light energy incident on the at least one reflective or transflective outer major surface, a light injection region adjacent the at least one reflective or transflective outer major surface, and a distal surface opposite the light injection region; and

a first switchable diffuser disposed at least partially within the optical volume, the first switchable diffuser having at least a first state and a second state, the first state characterized by a first haze and the second state characterized by a second haze different from the first haze, wherein the at least one reflective or transflective outer major surface defines opposing boundaries of the optical volume, and wherein the opposing boundaries substantially converge from the light injection region to the distal surface, wherein the first switchable diffuser includes a plurality of independently addressable regions, each region independently capable of being in the first state or in the second state; and

wherein the at least one reflective or transflective outer major surface includes a plurality of zones having a reflective property that varies discretely from zone to zone by spatial variation in a perforation density of the film, the zones being in one-to-one correspondence with the regions such that when each region is in the first state and for each zone, light injected into the light injection region is incident on the zone after being transmitted through a region of the first switchable diffuser corresponding to the zone.

13. The lighting component of claim 12 further comprising at least one sensor and a controller, wherein the controller is configured to receive at least one input from the at least one sensor and to provide a control signal to the first switchable diffuser.