Sunday, February 5, 2012

THOMAS ALFA EDISON





Nearly all of Edison's patents were utility patents, which were protected for a 17-year period and included inventions or processes that are electrical, mechanical, or chemical in nature. About a dozen were design patents, which protect an ornamental design for up to a 14-year period. As in most patents, the inventions he described were improvements over prior art. The phonograph patent, in contrast, was unprecedented as describing the first device to record and reproduce sounds. Edison did not invent the first electric light bulb, but instead invented the first commercially practical incandescent light. Many earlier inventors had previously devised incandescent lamps, including Henry Woodward and Mathew Evans. Others who developed early and commercially impractical incandescent electric lamps included Humphry Davy, James Bowman Lindsay, Moses G. Farmer, William E. Sawyer, Joseph Swan and Heinrich Göbel. Some of these early bulbs had such flaws as an extremely short life, high expense to produce, and high electric current drawn, making them difficult to apply on a large scale commercially. In 1878, Edison applied the term filament to the element of glowing wire carrying the current, although the English inventor Joseph Swan had used the term prior to this. Swan developed an incandescent light with a long lasting filament at about the same time as Edison, as Swan's earlier bulbs lacked the high resistance needed to be an effective part of an electrical utility. Edison and his co-workers set about the task of creating longer-lasting bulbs. In Britain, Joseph Swan had been able to obtain a patent on the incandescent lamp; though Edison had already been making successful lamps for some time, his patent application was incompletely prepared and failed. Unable to raise the required capital in Britain because of this, Edison was forced to enter into a joint venture with Swan (known as Ediswan). Swan acknowledged that Edison had anticipated him, saying "Edison is entitled to more than I ... he has seen further into this subject, vastly than I, and foreseen and provided for details that I did not comprehend until I saw his system".By 1879, Edison had produced a new concept: a high resistance lamp in a very high vacuum, which would burn for hundreds of hours. While the earlier inventors had produced electric lighting in laboratory conditions, dating back to a demonstration of a glowing wire by Alessandro Volta in 1800, Edison concentrated on commercial application, and was able to sell the concept to homes and businesses by mass-producing relatively long-lasting light bulbs and creating a complete system for the generation and distribution of electricity.
On February 11, 2011, on Thomas Edison's 164th birthday, Google's homepage featured an animated Google Doodle commemorating his many inventions. When the cursor was hovered over the doodle, a series of mechanisms seemed to move, causing a lightbulb to glow.

No comments:

Post a Comment