Kachun P Lee

US Patent:

8598793, Dec 3, 2013

Filed:

May 12, 2011

Appl. No.:

13/106808

Inventors:

Xiantao Yan - Palo Alto CA, US
Kachun Lee - Fremont CA, US
Zequn Mei - Fremont CA, US

Assignee:

LedEngin, Inc. - San Jose CA

International Classification:

H05B 37/02

US Classification:

315151

Abstract:

The color of an LED-based lamp can be tuned to a desired color or color temperature. The lamp can include two or more independently addressable groups of LEDs associated with different colors or color temperatures and a total-internal-reflection (TIR) color-mixing lens to produce light of a uniform color by mixing the light from the different groups of LEDs. The color of the output light is tuned by controllably dividing an input current among the groups of LEDs. Tuning can be performed once, e. g. , during manufacture, and the lamp does not require active feedback components for maintaining color temperature.

US Patent:

20120286699, Nov 15, 2012

Filed:

May 12, 2011

Appl. No.:

13/106810

Inventors:

Xiantao Yan - Palo Alto CA, US
Kachun Lee - Fremont CA, US

Assignee:

LedEngin, Inc. - Santa Clara CA

International Classification:

H05B 37/02

US Classification:

315294

Abstract:

An apparatus is used to tune the color produced by an LED-based lamp to a desired color or color temperature. To support tuning, the lamp can include two or more independently addressable groups of LEDs. Color or color temperature is tuned by controllably dividing an input current among the groups of LEDs. The apparatus determines an optimal division of the input current based on a linear interpolation between measured values of color or color temperature produced by at least two different divisions of the input current.

US Patent:

20130075769, Mar 28, 2013

Filed:

Sep 22, 2011

Appl. No.:

13/240796

Inventors:

Xiantao Yan - Palo Alto CA, US
Kachun Lee - Fremont CA, US

Assignee:

LEDENGIN, INC. - San Jose CA

International Classification:

H01L 33/50
G06F 17/50

US Classification:

257 89, 438 27, 700 99, 257E33061, 901 2

Abstract:

An emitter for an LED-based lighting device has multiple groups of LEDs that are independently addressable, allowing the emitter to be tuned to a desired color bin (e.g., a specific white color) by adjusting the relative current supplied to different groups. The LED dies for the groups and a phosphor chip for each LED die are individually selected such that each LED-die/phosphor-chip combination produces light in a desired source region associated with the group to which the LED belongs. Robotic pick-and-place systems can be used to automate assembly of the emitters by selecting LED dies from a bin based on based on spectral characteristics and phosphor chips from a number of distinct phosphor chip types.

US Patent:

20130229125, Sep 5, 2013

Filed:

Feb 28, 2013

Appl. No.:

13/781162

Inventors:

Kachun Lee - Fremont CA, US
David Tahmassebi - Los Gatos CA, US

Assignee:

LEDENGIN, INC. - San Jose CA

International Classification:

H05B 33/08
H05B 33/10

US Classification:

315210, 445 3

Abstract:

A light-emitting diode (LED) emitter module includes a substrate having a plurality of base layers of an electrically insulating material, a plurality of electrical contacts disposed on a top one of the base layer, and a plurality of electrical paths coupled to the electrical contacts, wherein at least a portion of the plurality of electrical paths is disposed between the base layers. The emitter module also includes two or more groups of light-emitting diodes (LEDs), each group having one or more LEDs, and each of the LEDs is coupled to an electrical contact. The electrical paths are configured for feeding separate electrical currents to the groups of LEDs. The emitter module also includes a memory device containing information associating a plurality of output light colors with a corresponding plurality of combinations of electrical currents, each combination specifying an electric current for each of the two or more groups of LEDs.

US Patent:

20190332098, Oct 31, 2019

Filed:

May 8, 2019

Appl. No.:

16/407052

Inventors:

- San Jose CA, US
Kachun Lee - Fremont CA, US

Assignee:

LedEngin, Inc. - San Jose CA

International Classification:

G05B 19/418
F21K 9/90
F21K 9/64
F21K 9/60
H01L 33/00

Abstract:

An emitter for an LED-based lighting device has multiple groups of LEDs that are independently addressable, allowing the emitter to be tuned to a desired color bin (e.g., a specific white color) by adjusting the relative current supplied to different groups. The LED dies for the groups and a phosphor chip for each LED die are individually selected such that each LED-die/phosphor-chip combination produces light in a desired source region associated with the group to which the LED belongs. Robotic pick-and-place systems can be used to automate assembly of the emitters by selecting LED dies from a bin based on spectral characteristics and phosphor chips from a number of distinct phosphor chip types.

US Patent:

20190090323, Mar 21, 2019

Filed:

Nov 16, 2018

Appl. No.:

16/193606

Inventors:

- San Jose CA, US
Kachun Lee - Fremont CA, US
David Tahmassebi - Los Gatos CA, US

Assignee:

LedEngin, Inc. - San Jose CA

International Classification:

H05B 33/08
H05B 33/10

Abstract:

A method for making a light-emitting diode (LED) emitter module includes providing a substrate and providing two or more groups of LED dies disposed on the substrate. Each group has one or more LED dies, and each of the LED dies is coupled to an electrical contact and electrical paths are configured for feeding separate electrical currents to the groups of LED dies. The method also includes determining information associating a plurality output light colors with a corresponding plurality of combinations of electrical currents, each combination specifying a plurality of electrical current values, each electrical current value being associated with an LED die from one of the two or more groups of LED dies. The method also includes storing the information in the memory device, and providing a circuit for accessing the information in a memory device.

US Patent:

20180132329, May 10, 2018

Filed:

Nov 10, 2016

Appl. No.:

15/348940

Inventors:

- San Jose CA, US
Kachun Lee - Fremont CA, US
Shifan Cheng - Milpitas CA, US
Julio Cesar Alvarado - East Palo Alto CA, US

Assignee:

LedEngin, Inc. - San Jose CA

International Classification:

H05B 33/08
H01L 25/075
H01L 33/62
H01L 33/48
H01L 33/54
H01L 33/56
H01L 33/58

Abstract:

A light emitting device can include a substrate with LED chips disposed on a surface of the substrate. The LED chips can include chips of at least four different colors. Electrical paths disposed in part on the substrate and in part within the substrate can connect the LED chips into at least three independently addressable groups, and the number of independently addressable groups can be less than the number of colors of LED chips, so that at least one of the groups includes LED chips of two or more different colors.

US Patent:

20180007759, Jan 4, 2018

Filed:

Apr 13, 2017

Appl. No.:

15/487317

Inventors:

- San Jose CA, US
Kachun Lee - Fremont CA, US

Assignee:

LedEngin, Inc. - San Jose CA

International Classification:

H05B 33/08
H01L 25/075
H01L 33/62

Abstract:

A substrate for an LED emitter includes a body with a recess region formed therein. Bonding pads are disposed within the recess region, including LED bonding pads for LEDs and supporting chip bonding pads for one or more semiconductor chips that provide supporting circuitry (e.g., driver and/or controller circuitry) to support operation of the LEDs. External electrical contacts can be disposed outside the recess region. Electrical paths, disposed at least partially within the body of the substrate, connect the external electrical contacts to a first subset of the supporting chip bonding pads and connect a second subset of the supporting chip bonding pads to the plurality of LED bonding pads such that one or more supporting chips connected to the controller pads can be operated to deliver different operating currents to different ones of the LEDs.