US 11,994,285 B2 · Controlling off-state appearance of a light emitting device

Abstract

Systems for apparatuses formed of light emitting devices. Solutions for controlling the off-state appearance of lighting system designs is disclosed. Thermochromic materials are selected in accordance with a desired off-state of an LED device. The thermochromic materials are applied to a structure that is in a light path of light emitted by the LED device. In the off-state the LED device produces a desired off-state colored appearance. When the LED device is in the on-state, the thermochromic materials heat up and become more and more transparent. The light emitted from the device in its on-state does not suffer from color shifting due to the presence of the thermochromic materials. Furthermore, light emitted from the LED device in its on-state does not suffer from attenuation due to the presence of the thermochromic materials. Techniques to select and position thermochromic materials in or around LED apparatuses are presented.

Claims18

Dependent claims

A structure comprising:

a semiconductor light emitting device having an on-state and an off-state;
a phosphor layer disposed on the semiconductor light emitting device;
and
a thermochromic layer disposed on the phosphor layer, the thermochromic layer comprising a pigment having a transparent liquid state at a first temperature and a colored solid state at a second temperature lower than the first temperature, the pigment configured to transition from the colored solid state to the transparent liquid state within 250 milliseconds of the semiconductor light emitting device being switched from the off-state to the on-state,
wherein the pigment is a leuco dye.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application

17/964,194Filed 12 Oct 2022 · continuation

Priority

23 Jul 2015

Published

US 2023/0045625 A19 Feb 2023

Granted

28 May 2024

Term ends

Not estimatedThe source records don’t support an estimate.

Classification17 codes

F21V 9/40
Elements for modifying spectral properties, polarisation or intensity of the light emitted, e.g. filters: with provision for controlling spectral…
C09B 67/0097
Influencing the physical, e.g. the dyeing or printing properties of dyestuffs without chemical reactions, e.g. by treating with solvents…
F21K 9/00
Light sources using semiconductor devices as light-generating elements
F21K 9/20
Light sources using semiconductor devices as light-generating elements, e.g. using light-emitting diodes [LED] or lasers: light sources comprising…

Family

Application62/196,178Us provisional application · filed 23 Jul 2015

PCT/US2016/039782Parent of this continuation · filed 28 Jun 2016

Application17/028,926Parent of this continuation · filed 22 Sep 2020

US 10,797,206 B2Parent of this continuation · filed 6 Oct 2020

US 2023/0045625 A1Pre-grant publication · published 9 Feb 2023

US 11,486,562 B2Parent of this continuation

Application15/747,076Parent of this continuation

US 2018/0374999 A1Published application

US 2021/0013380 A1Published application

US 11,994,285 B2This patent

From the US filing history. Foreign family members aren’t listed.

Controlling off-state appearance of a light emitting device

Life of this patent

Controlling off-state appearance of a light emitting device

Life of this patent

Abstract

Claims18