US Patent No. 10,015,855

DITHERING AND DIMMING TECHNIQUES FOR LIGHT EMITTING DIODE (LED) LIGHTING SYSTEMS


Patent No. 10,015,855
Issue Date July 03, 2018
Title Dithering And Dimming Techniques For Light Emitting Diode (led) Lighting Systems
Inventorship Herman Ferrier, Scotts Valley, CA (US)
Assignee LUMENETIX, INC., Scotts Valley, CA (US)

Claim of US Patent No. 10,015,855

1. A dimming system comprising:a color string that includes one or more light emitting diodes (LEDs) of a substantially similar color;
an adjustable current source configured to provide an electric current to the color string,
wherein the adjustable current source has a minimum threshold level at which the adjustable current source is able to provide the electric current without producing leakage current;
an analog micro-pulse generator configured to provide an electric current pulse to the color string at an order smaller than the minimal threshold level;
a shunt circuit configured to short a current source at a specified frequency; and
a controller that configures the adjustable current source, the analog micro-pulse generator, the shunt circuit, or a combination thereof based on a dimming level specified by a user,
wherein, when the dimming level falls within a first dimming range, the controller configures the adjustable current source to drive the color string at an output level between a maximum threshold level and the minimum threshold level, and
wherein, when the dimming level falls within a second dimming range lower than the first dimming range, the controller configures the adjustable current source to drive the color string at an output level matching the minimum threshold level and the shunt circuit to modulate the output level at a first frequency proportional to the dimming level.