US 2015/0091472 A1Published application

Lighting device

AssigneePanasonic Corporation

InventorsKazuyoshi KADOTANI, Minoru MAEHARA

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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.

Claims10

Dependent claims

A lighting device comprising:

a first light source composed of first light emitting diodes, each being configured to emit light with a first color temperature;
a second light source composed of second light emitting diodes, each being configured to emit light with a second color temperature lower than the first color temperature, the number of second light emitting diodes being less than the number of first light emitting diodes;
a lighting circuit configured to cause the first light source and the second light source to light on by supplying a first drive current and a second drive current to the first light source and the second light source, respectively;
and
a control circuit configured to control lighting conditions of the first light source and the second light source so that:
total light intensity of the first light source varies in response to variation in a dimming level instructed by a dimming signal;
and total light intensity of the second light source is kept constant whether the dimming level is varied or not.

4 more elements

Dependencies are inferred from the claim text.