Liang Weihong Chen

US Patent:

8149493, Apr 3, 2012

Filed:

Sep 1, 2009

Appl. No.:

12/552043

Inventors:

Liang Chen - Woburn MA, US

Assignee:

Sifotonics Technologies (USA) Inc. - Woburn MA

International Classification:

G02F 1/03
G02B 6/10

US Classification:

359250, 385130

Abstract:

In a general aspect, a device includes a substrate, a light transmission formed on a top surface of the substrate, a first contact, and a second contact. The light transmission structure includes a first doped region; a second doped region doped oppositely to the first region; a lateral junction between a part of the first doped region and a part of the second doped region, the lateral junction oriented substantially perpendicular to the top surface of the substrate; and a vertical junction between a part of the first doped region and a part of the second doped region, the vertical junction oriented substantially parallel to the top surface of the substrate. The first contact is in electrical contact with the first region and the second contact is in electrical contact with the second region.

US Patent:

8257997, Sep 4, 2012

Filed:

Oct 17, 2008

Appl. No.:

12/253497

Inventors:

Liang Chen - Woburn MA, US
Chingyin Hong - Lexington MA, US
Fuwan Gan - Woburn MA, US
Dong Pan - Andover MA, US

Assignee:

Sifotonics Technologies (USA) Inc. - Woburn MA

International Classification:

H01L 31/062
H01L 31/113
H01L 21/00

US Classification:

438 71, 257290, 257E31032

Abstract:

In one aspect, a method includes forming a pit in a top surface of a substrate by removing a portion of the substrate and growing a semiconductor material with a bottom surface on the pit, the semiconductor material different than the material of the substrate. The pit has a base recessed in the top surface of the substrate. In another aspect, a structure includes a substrate having a top surface, the substrate including at least one pit having a base lower than the top surface of the substrate, and a semiconductor material having a bottom surface formed on the base of the pit.

US Patent:

20070040516, Feb 22, 2007

Filed:

Aug 15, 2005

Appl. No.:

11/204307

Inventors:

Liang Chen - McKinney TX, US

International Classification:

H05B 41/36

US Classification:

315291000

Abstract:

An AC-to-DC converter with PFC or without PFC generates an output constant voltage at any predetermined value (no matter less or more than input line peak voltage, or even equal to input line peak voltage) with an input line AC voltage with wide range (Typical sinusoidal 110 VAC, 60 Hz or 220 VAC, 50 Hz). It is mainly used as power supply for lamp. Previous power supply for lamp has low frequency component or high frequency component. (1) Low frequency light cause eyes pupil and crystalline lens will adjust 60 times, 120 or many times per second to cause eyes tired. Pupil open wide and crystalline lens adjust to collect more light to focus on retina for seeing clearly at weak light while pupil open narrow and crystalline lens adjust to collect less light to focus on retina at strong light to prevent retina from strong light harm and hurt. In the long run, muscles to control pupil and crystalline lens become very tired and become flabby. Then the muscle can't adjust pupil and crystalline according to distance and brightness so that myopia is caused. (2) High frequency voltage causes lamp brightness changes too fast. Eyes can not adjust fast enough to follow the brightness change of lamp for high frequency voltage. But high frequency large current on the secondary cause high EMI that has risk to harm people's health. High frequency light causes EMI issue. Peoples' eyes can't keep up with high frequency light. Peak strong light shine on the retina for pupil can't shrink at high frequency light. In the long run, retina will be harmed and affect eyesight is affected, cornea dryness or crystalline lens opacity is caused. My invention of power supply lamp has only DC constant voltage on lamp. Lamp's brightness is constant and has no low frequency or high frequency component Thus peoples' eyes and health are protected to maximum extent. The output voltage is regulated at predetermined DC constant value by feedback. You can adjust feedback potentiometer value to set output voltage. Potentiometer and resistor voltage divider with auxiliary winding, (opto-coupler, digital isolator or direct feedback) compose the dimming feedback circuit. It is convenient to adjust the brightness of lamp for eyes' comfort by adjusting the potentiometer resistance value. My invention can be used directly on second category lamp that doesn't need high voltage with ballast to start the lamp. Most of them use heat generated by filament or diode etc to create light. Such as Halogen, Incandescent, LED, PAR lamp, miniature sealed beam lamp, Projection lamp, automotive lamp, some stage and studio lamp, DC fluorescent lamp etc. The converter realized pulse-by-pulse or other current limit protection by sense the current sense resistor or signal transformer. One stage DC sinusoidal to DC constant converter can be implemented by all kinds of topologies other than the following topologies as long as they can convert DC sinusoidal voltage to DC constant voltage. Buck, Boost, Buck-boost, Noninverting buck-boost ,H-Bridge, Watkins-Johnson, Current-fed bridge, Inverse of Watkins-Johnson, Cuk, SEPIC, Inverse of SEPIC, Buck square, full bridge, half bridge, Forward, Two-transistor Forward, Push-pull, Flyback, Push-pull converter basedon Watkins-Johnson, Isolated SEPIC, Isolated Inverse SEPIC, Isolated Cuk, Two-transistor Flyback etc One stage AC to DC converter can be realized by discrete components without controller , active startup circuit, feedback circuit or sample circuit. Main switch and active startup circuit can be integrated in IC controller. The AC to DC converter is not used only for lamp. It is can also be used for any device requires DC power supply in all the industrial areas. (Telecommunication, Storage, Personal computer, cell phone power supply and charger, video game etc) For example, Bus AC to DC converter, PFC converter, PFC converter for lighting Computer power supply, Monitor power supply, notebook adapter, LCD TV, AC/DC adapter, adjusted voltage charger, Power tool charger, Electronic ballast, Video game power supply etc.

US Patent:

20070138971, Jun 21, 2007

Filed:

Feb 15, 2007

Appl. No.:

11/706645

Inventors:

Liang Chen - McKinney TX, US

International Classification:

H05B 39/04

US Classification:

31520900R

Abstract:

An AC-to-DC voltage converter as power supply for lamp converts an AC input voltage to a constant DC voltage at predetermined value set by potentiometer. The converter includes input power supply input protection circuit EMI filter rectifier filter converter output filter lamp start circuit control circuit biasing circuit sampling circuit output protection circuit feedback and dimming circuit and input monitor circuit This version is a flyback converter; versions from other topologies etc are also provided. The converter has feedback function that can regulate output voltage at predetermined value. The converter has dimming function and can adjust lamp brightness for conformability. The output constant brightness decreases peoples' eyes fatigue to minimum level.

US Patent:

20100285081, Nov 11, 2010

Filed:

Nov 12, 2008

Appl. No.:

12/741478

Inventors:

Liang Chen - Cambridge MA, US
Lev E. Bromberg - Swampscott MA, US
Trevor Alan Hatton - Sudbury MA, US
Gregory C. Rutledge - Newton MA, US

Assignee:

MASSACHUSETTS INSTITUTE OF TECHNOLOGY - CAMBRIDGE MA

International Classification:

A01N 25/00
A01N 47/44
A01P 1/00

US Classification:

424405, 514635

Abstract:

One aspect of the invention relates to an antimicrobial fiber formed from an electroprocessed blend of at least one polymer, at least one antimicrobial agent, and at least one crosslinker. Another aspect of the invention relates to an antimicrobial fiber formed from an electroprocessed blend of at least one polymer and at least one crosslinker, which is then coated with an antimicrobial compound or antimicrobial polymer.

US Patent:

20100290060, Nov 18, 2010

Filed:

May 14, 2010

Appl. No.:

12/780389

Inventors:

Masoud Mohazzab - Andover MA, US
Liang Chen - Woburn MA, US

Assignee:

Andover Photonics, Inc. - Woburn MA

International Classification:

G01B 9/02
G01B 11/24

US Classification:

356492, 356511

Abstract:

A system for measuring a shape of a target object includes a photonic integrated circuit and a light detector. The photonic integrated circuit includes a phase shifter configured to change a phase difference between a first portion of light and a second portion of light within the phase shifter, and an output element configured to output the light from the phase shifter directly toward the target object. The output element includes a first output waveguide configured to act as a first point source; and a second output waveguide configured to act as a second point source. The light detector is positioned to receive reflected light from the target object.

US Patent:

20110174720, Jul 21, 2011

Filed:

Jul 21, 2010

Appl. No.:

12/840916

Inventors:

Liang Chen - Cambridge MA, US
Lev E. Bromberg - Swampscott MA, US
T. Alan Hatton - Sudbury MA, US
Gregory C. Rutledge - Newton MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

B01D 39/00

US Classification:

2103231, 21050035, 21050042, 21050027, 21050033, 21050029, 2105003

Abstract:

Described is the application of layer-by-layer (LbL) electrostatic assembly techniques to electrospun nanofibers in order to fabricate novel, breathable electrospun fiber-based chemical and biological detoxifying protective fabrics and filters. The combination of layer-by-layer electrostatic assembly and electrospinning technique allows one to take advantage of high specific surface area, light weight and breathability of electrospun fiber mats while simultaneously providing the versatility to incorporate different functional polyelectrolytes to achieve multifunctional coatings for both chemical and biological protection together. The functionalized fiber mats can be incorporated into breathable chemical and biological protective fabrics, filters and masks. In addition, LbL electrostatic coating of porous non-woven materials provides the versatility to generate multifunctional polymer-based membrane materials for other applications.

US Patent:

20220180918, Jun 9, 2022

Filed:

Dec 9, 2020

Appl. No.:

17/116634

Inventors:

- Boise ID, US
Liang Chen - Allen TX, US

International Classification:

G11C 11/4096
G11C 11/4076
G06F 3/06

Abstract:

A host device and memory device perform internal write leveling of a data strobe with a write command. The memory device includes an input-output interface that receives the data strobe from the host device. The memory device also includes internal write circuitry configured to launch an internal write signal. The internal write circuitry includes an emulation loop configured to emulate circuitry in a clock path of a write clock generated from the clock and used to generate a feedback clock. The internal write circuitry includes a write delay lock loop configured to receive the write clock and the feedback clock to determine a number of cycles used for the loop, transmit the number of cycles to the host device to be used as a cycle adjust in an internal write leveling process, and complete the internal write leveling process with the host device using the cycle adjust.