Early research and development
The story of light bulbs began long before Edison obtained the first commercially successful light bulb patent in 1879. 1800, the Italian inventor Alessandro Volta invented the first practical power generation method, namely piling. It is made of alternating zinc and copper disks, interspersed with several layers of cardboard immersed in salt water. When the two ends of copper wires are connected, the battery stack is electrified. Although it is actually the predecessor of modern batteries, Volta's luminous copper wire is also considered as one of the earliest forms of incandescent lighting.
Shortly after Walter introduced his discovery of continuous power supply to the Royal Society of London, humphry davy, a British chemist and inventor, made the world's first electric lamp by connecting a Volt reactor to a charcoal electrode. The invention of David 1802 is called arc lamp, which is named after the bright arc between two carbon rods.
Although David's arc lamp is undoubtedly an improvement on Walter's independent lampshade, it is still not a very practical lighting source. This basic lamp burns out quickly, and it is too bright to be used at home or in the workplace. But the principle behind David arc lamp has been used in the development of many other electric lamps and bulbs of 1800.
1840, the British scientist Warren de la Rue developed an efficient light bulb, which used coiled platinum wire instead of copper, but the high price of platinum prevented the light bulb from achieving commercial success. 1848, the Englishman William Staite developed a clockwork mechanism to adjust the movement of the corrosive carbon rod of the lamp, thus prolonging the life of the traditional arc lamp. However, the cost of the battery used to power Staite's lamp hindered the inventor's business activities.
Joseph swan vs Thomas Edison
1850, British chemist joseph swan solved the cost-benefit problem of the previous inventor. By 1860, he invented the light bulb and used carbonized paper wire instead of platinum wire. According to the Smithsonian Institution, Swan obtained a patent in the UK in 1878, and showed the working light in a speech in Newcastle, England in February 1879. Like the early version of the light bulb, the swan filament is also placed in a vacuum tube to minimize contact with oxygen, thus prolonging its service life. Unfortunately, for Swan, the vacuum pump of his time was not as efficient as it is now. Although his prototype can be well used for demonstration, it is not realistic in practical use.