LED filament light bulb is a LED lamp which is designed to resemble a traditional incandescent light bulb with visible filaments for aesthetic and light distribution purposes,but with the high efficiency of lighting-emitting diodes(LEDs).It produces its light using LED filaments,which are series-connected string of diodes that resemble in appearance the filaments of incandescent light bulbs.
They are direct replacement for conventional clear(or frosted) incandscent bulbs,as they are made with the same envelopes shapes,the same bases that fit the same sockets,and work at the same supply voltage.They may be used for their appearance,similar when lit to a clear incandescent bulb,or for their wide angle of light distribution,typically 300°.They are also more efficient than many other LED lamps.
A LED filament type design light bulb was produced by Ushio LIghting in 2008,intended to mimic the appearance of a standard light bulb.
Contemporary bulbs typically used a single large LED or matrix of LED attached to one large heatsink.As a consequence,these bulbs typically produced a beam only 180 degrees wide.By about 2015,LED filament bulbs had been introduced by several manufacturers.These designs used several LED filament light emitters,similar in appearance when lit to the filament of a clear,standard incandescent bulb,and very similar in detail to the multiple fillaments of the early Edison incandescent bulbs.
LED filament bulbs were patented by Ushio and Sanyo in 2008.Pansonic described a flat arrangement with modules similar to filament in 2013.Two other independent patent applications were filed in 2014 but were never granted.The early filed patents included a heat drain under the LEDs.Ath that time,luminous efficacy of LEDs was under 100 lm/W.By the late 2010s,this had risen to near 160 lm/W.The simple linear regulator used by some cheaper bulbs will cause some flickering at twice the frequency of the mains alternating current,which can be difficult to detect,but possibily contributes to eyestrain and headaches.
Post time: Feb-13-2023
