The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Jun. 21, 2016

Filed:

Sep. 26, 2014
Applicant:

Panasonic Corporation, Osaka, JP;

Inventors:

Kazuyoshi Kadotani, Osaka, JP;

Minoru Maehara, Osaka, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H05B 37/02 (2006.01); H05B 33/08 (2006.01);
U.S. Cl.
CPC ...
H05B 33/0815 (2013.01); H05B 33/083 (2013.01); H05B 33/086 (2013.01); H05B 33/0845 (2013.01); H05B 33/0857 (2013.01);
Abstract

A lighting device includes a first light source composed of first LEDs each configured to emit light with a first color temperature, a second light source composed of second LEDs each configured to emit light with a second color temperature lower than the first color temperature, a lighting circuit, and a control circuit. The number of second LEDs is less than that of the first LEDs. The lighting circuit is configured to cause the first and second light sources to light on by supplying first and second drive currents to the first and second light sources, respectively. The control circuit is configured to control lighting conditions of the first and second light sources so that: total light intensity of the first light source varies in response to a dimming signal; and total light intensity of the second light source is kept constant independently of the dimming signal.


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