Chia Pin Hsu

US Patent:

20170184849, Jun 29, 2017

Filed:

Aug 16, 2016

Appl. No.:

15/237800

Inventors:

Chia Wei Hsu - Cambridge MA, US
Wenjun Qiu - Chicago IL, US
Bo Zhen - Cambridge MA, US
Ofer Shapira - Cambridge MA, US
Marin Soljacic - Belmont MA, US

International Classification:

G02B 27/01
G02B 5/02

Abstract:

Transparent displays enable many useful applications, including heads-up displays for cars and aircraft as well as displays on eyeglasses and glass windows. Unfortunately, transparent displays made of organic light-emitting diodes are typically expensive and opaque. Heads-up displays often require fixed light sources and have limited viewing angles. And transparent displays that use frequency conversion are typically energy inefficient. Conversely, the present transparent displays operate by scattering visible light from resonant nanoparticles with narrowband scattering cross sections and small absorption cross sections. More specifically, projecting an image onto a transparent screen doped with nanoparticles that selectively scatter light at the image wavelength(s) yields an image on the screen visible to an observer. Because the nanoparticles scatter light at only certain wavelengths, the screen is practically transparent under ambient light. Exemplary transparent scattering displays can be simple, inexpensive, scalable to large sizes, viewable over wide angular ranges, energy efficient, and transparent simultaneously.

US Patent:

20160216600, Jul 28, 2016

Filed:

Apr 4, 2016

Appl. No.:

15/090348

Inventors:

Chia Wei Hsu - Cambridge MA, US
Wenjun Qiu - Chicago IL, US
Bo Zhen - Cambridge MA, US
Ofer Shapira - Cambridge MA, US
Marin Soljacic - Belmont MA, US

International Classification:

G03B 21/62
G02B 5/02

Abstract:

Transparent displays enable many useful applications, including heads-up displays for cars and aircraft as well as displays on eyeglasses and glass windows. Unfortunately, transparent displays made of organic light-emitting diodes are typically expensive and opaque. Heads-up displays often require fixed light sources and have limited viewing angles. And transparent displays that use frequency conversion are typically energy inefficient. Conversely, the present transparent displays operate by scattering visible light from resonant nanoparticles with narrowband scattering cross sections and small absorption cross sections. More specifically, projecting an image onto a transparent screen doped with nanoparticles that selectively scatter light at the image wavelength(s) yields an image on the screen visible to an observer. Because the nanoparticles scatter light at only certain wavelengths, the screen is practically transparent under ambient light. Exemplary transparent scattering displays can be simple, inexpensive, scalable to large sizes, viewable over wide angular ranges, energy efficient, and transparent simultaneously.

US Patent:

20140185282, Jul 3, 2014

Filed:

Oct 30, 2013

Appl. No.:

14/067471

Inventors:

CHIA WEI HSU - CAMBRIDGE MA, US
WENJUN QIU - CAMBRIDGE MA, US
BO ZHEN - CAMBRIDGE MA, US
OFER SHAPIRA - CAMBRIDGE MA, US
MARIN SOLJACIC - BELMONT MA, US

Assignee:

MASSACHUSETTS INSTITUTE OF TECHNOLOGY - Cambridge MA

International Classification:

F21V 33/00
F21V 5/00

US Classification:

362231, 362235, 427164, 977773

Abstract:

Transparent displays enable many useful applications, including heads-up displays for cars and aircraft as well as displays on eyeglasses and glass windows. Unfortunately, transparent displays made of organic light-emitting diodes are typically expensive and opaque. Heads-up displays often require fixed light sources and have limited viewing angles. And transparent displays that use frequency conversion are typically energy inefficient. Conversely, the present transparent displays operate by scattering visible light from resonant nanoparticles with narrowband scattering cross sections and small absorption cross sections. More specifically, projecting an image onto a transparent screen doped with nanoparticles that selectively scatter light at the image wavelength(s) yields an image on the screen visible to an observer. Because the nanoparticles scatter light at only certain wavelengths, the screen is practically transparent under ambient light. Exemplary transparent scattering displays can be simple, inexpensive, scalable to large sizes, viewable over wide angular ranges, energy efficient, and transparent simultaneously.

US Patent:

20140185284, Jul 3, 2014

Filed:

Dec 30, 2013

Appl. No.:

14/143558

Inventors:

CHIA WEI HSU - Cambridge MA, US
WENJUN QIU - Cambridge MA, US
BO ZHEN - Cambridge MA, US
OFER SHAPIRA - Cambridge MA, US
MARIN SOLJACIC - Belmont MA, US

International Classification:

F21V 33/00
F21V 9/12
F21V 9/08

US Classification:

362231, 362260, 427595, 977773

Abstract:

Disclosed herein are transparent color displays with nanoparticles made with nonlinear materials and/or designed to exhibit optical resonances. These nanoparticles are embedded in or hosted on a transparent substrate, such as a flexible piece of clear plastic or acrylic. Illuminating the nanoparticles with invisible light (e.g., infrared or ultraviolet light) causes them to emit visible light. For example, a rare-earth doped nanoparticle may emit visible light when illuminated simultaneoulsy with a first infrared beam at a first wavelength λand a second infrared beam at a second wavelength λ. And a frequency-doubling nanoparticle may emit visible light when illuminated with a single infrared beam at the nanoparticle's resonant frequency. Selectively addressing these nanoparticles with appropiately selected pump beams yields visible light emitted from the nanoparticles hosted by the transparent substrate in a desired pattern.