US Patent No. 10,602,597

SOLID-STATE LIGHTING WITH A REDUCED TEMPORAL LIGHT ARTIFACT


Patent No. 10,602,597
Issue Date March 24, 2020
Title Solid-state Lighting With A Reduced Temporal Light Artifact
Inventorship Chungho Hsia, Bellevue, WA (US)
Assignee ALEDDRA INC., Renton, WA (US)

Claim of US Patent No. 10,602,597

1. A light-emitting diode (LED) luminaire, comprising:one or more LED arrays;
at least one full-wave rectifier configured to couple to alternate-current (AC) mains and convert a line voltage from the AC mains into a first direct-current (DC) voltage;
at least one input filter coupled to the at least one full-wave rectifier, the at least one input filter configured to suppress an electromagnetic interference (EMI) noise;
a power switching converter comprising a first control device configured to correct a power factor, a transformer comprising a primary winding and a secondary winding, a first ground reference, a second ground reference electrically isolated from the first ground reference, a first electronic switch controlled by the first control device, a first at least one current sensing resistor coupled between the first electronic switch and the first ground reference, and at least one rectifier circuit coupled to the secondary winding, wherein the power switching converter is coupled to the at least one full-wave rectifier via the at least one input filter and configured to convert the first DC voltage into a second DC voltage via the transformer and the at least one rectifier circuit; and
an LED driving circuit comprising a second control device, a second electronic switch, an inductor with current charging and discharging controlled by the second electronic switch, a first diode coupled between the second electronic switch and the second ground reference, a second at least one current sensing resistor coupled between the second electronic switch and the second control device, and an output capacitor connected between the inductor and the second ground reference, wherein the LED driving circuit is coupled to the at least one rectifier circuit and configured to convert the second DC voltage into a third DC voltage with an LED driving current to drive the one or more LED arrays with a flicker-reduced light emission,
wherein:
the second electronic switch is configured to modulate the second DC voltage at a switching frequency controlled by the second control device; and
the LED driving circuit is further configured to output a reduced low-frequency current ripple to drive the one or more LED arrays.