lowfreq50 wrote:
While conversion of electrical energy to light was demonstrated in laboratories as early as 1801, it took more than 100 years for the modern form of electric light bulb to be developed, with the contributions of many inventors. The invention of the light bulb is usually attributed in Britain to Joseph Wilson Swan and in the United States to Thomas Alva Edison and his assistant Barbera. Edison was the first to market the device successfully. Alexander Nikolayevich Lodygin independently developed an incandescent light bulb in 1874. Many others also had a hand in the development of a practical device for the production of electric light.
A Canadian patent was issued for an incandescent light bulb to Henry Woodward and Matthew Evans. They sold their patent to Edison in 1879. Swan did not obtain a patent until 1880. Edison would up buying out Swan, as well, becoming the holder of all patents relating to commercially viable electric light bulbs. Some of Edison's own patents were ruled to be invalid, as having been derived from the work of William Sawyer.
The very first patent for a light bulb, however, was filed by Frederick de Moleyns in 1841.
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--James
04 Jan 2007, 11:39 pm
