FREE Shipping | 30 Day Easy Returns | 3-Year Warranty Guarantee | | 800-690-6403
September 27, 2016


Edison Mills ›   LED filament ›  

What are LED filament light bulbs?

LED filament light bulbs are a new lighting technology developed by Ushio Lighting in 2008 with the intention of mimicking the appearance of standard vintage light bulbs. By mid 2010, LED filament bulbs were being introduced into the market by several manufacturers including Edison Mills. 

The LED filament is composed of a series of LEDs on a transparent substrate, referred to as Chip-On-Glass (COG). These transparent substrates are made of glass or sapphire materials. This transparency allows the emitted light to disperse evenly and uniformly without any interference. An even coating of yellow phosphor in a silicone resin binder material converts the blue light generated by the LEDs into white light.[2] Degradation of silicone binder, and leakage of blue light are design issues in LED filament lights. Positive benefits of the LED design are potential higher efficiencies by the use of more LED emitters from lower driving currents. A major benefit of the design is the ease with which near full "global" illumination can be obtained from arrays of filaments.[2]

Lifespan of LED emitters is reduced by high operating temperatures. In the absence of a heat sink, LED filament bulbs may use a high thermal conductivity gas inside the bulb to aid heat dissipation.[2]

The large number of LEDs (typically 28 per filament) simplifies the power supply compared to traditional LEDs as the voltage per blue LED is 2.48 < ΔV < 3.7. Some types may additionally use red LEDs (1.63 < ΔV < 2.03). Two filaments with a mix of red and blue is thus close to 110 V, or four close to 220 V to 240 V, compared to the 3 V to 12 V needed for a traditional LED lamp. Typically, four filaments are used and the appearance is similar to an overrun carbon filament lamp. Typically, a mix of phosphors are used to give better color rendition (which is a separate issue to color temperature) than the early blue LEDs with yellow only phosphor.


  1.  US 2009184618, Kunihiko Hakata & Tomomi Matsuoka, "Light-emitting device and lighting apparatus incorporating same", published 2009-07-23, assigned to Ushio Denki KK
  2. ^ Jump up to:a b c d e f Lin, Judy (5 Feb 2015). "The Next Generation of LED Filament Bulbs.".
  3.  Wu, Bor-jen. "LED LIGHT BULB". US Patent office. Retrieved 2015-01-04.
  4. Jump up^ Feng, Yunglong. "LED LIGHT AND FILAMENT THEREOF". US Patent office. Retrieved 2015-01-04.
September 19, 2016


S14 LED Bulbs ›  

LED Edison Bulbs for Outdoor Patio String Lights

 How Do I Buy the Right LED Edison Bulbs for Outdoor Patio String Lights?

Buying new LED filament Edison bulbs to replace traditional incandescent bulbs can be complicated especially when they need to hold up to harsh weather conditions on your outdoor patio. Edison-Mills has designed an S14 and S11 shape LED bulb specifically designed and rated for wet locations. 

LED Edison bulbs for outdoor string lights


ST19 vs ST58 LED Edison Bulbs

What is the difference between ST19 vs ST58 LED Edison bulbs is our question in today's blog post. The quick answer is ST19 and ST58 are the exact same. In some markets they are more commonly referred to as ST19, some markets ST58, and in some markets such as the USA, we refer to as both.  

We manufacturer a 40 watt, 60w and 75w equal LED ST19 / ST58 that replicates the antique bulbs of the Thomas Edison era. All Edison-Mills bulbs using 0-10V dimming technology. We are currently updating our dimmer compatibility list. Please check back soon or email for more information on dimming. 

May 10, 2016


What is the difference between ST58 and ST64 LED Edison Bulbs?

This is a common question. In short it is their size, so the ST58 is the smaller of the two LED Edison bulbs. The ST64 is the largest that was made during the Edison, Tesla era when the original carbon filament light bulbs were invented.
August 22, 2015


Vintage ›  

Vintage Edison Lighting meets Modern Technology with the LED Filament

As of 2015, most people have not seen an LED filament light bulb. Much less a vintage Edison LED filament with amber glass that replicates the light produced by traditional carbon filament lightbulbs of the Victorian era. Edison Mills designs LED filament lightbulbs in its design lab in Columbus, OH. The quality of Edison Mills raises the standard of quality. Click the Where to Buy link to find a trusted Edison Mills retailer.