Nipkow’s mechanical disk served as the foundation for experiments on the transmission of visual images for several decades.
The number of scanned lines equaled the number of perforations, and each rotation of the disk produced a television frame.
As the disk rotated, light passed through the holes, separating pictures into pinpoints of light that could be transmitted as a series of electronic lines. Created by German inventor Paul Nipkow, the scanning disk was a large, flat metal disk with a series of small perforations arranged in a spiral pattern. The other key invention during the 1880s was the mechanical scanner system. It had a fluorescent screen that emitted a visible light (in the form of images) when struck by a beam of electrons. Initially created as a scanning device known as the cathode ray oscilloscope, the CRT effectively combined the principles of the camera and electricity. The invention of the cathode ray tube (CRT) by German physicist Karl Ferdinand Braun in 1897 played a vital role as the forerunner of the TV picture tube. As early as 1876, Boston civil servant George Carey envisioned complete television systems, putting forward drawings for a “selenium camera” that would enable people to “see by electricity” a year later (Federal Communications Commission, 2005).ĭuring the late 1800s, several technological developments set the stage for television. Early pioneers speculated that if audio waves could be separated from the electromagnetic spectrum to create radio, so too could TV waves be separated to transmit visual images. Inventors conceived the idea of television long before the technology to create it appeared.
Today, as Internet technology and satellite broadcasting change the way people watch television, the medium continues to evolve, solidifying its position as one of the most important inventions of the 20th century. Kennedy and Martin Luther King assassinations and the Vietnam War in the 1960s, the Challenger shuttle explosion in 1986, the 2001 terrorist attacks on the World Trade Center, and the impact and aftermath of Hurricane Katrina in 2005 have all played out on television, uniting millions of people in shared tragedy and hope. Both reflecting and shaping cultural values, television has at times been criticized for its alleged negative influences on children and young people and at other times lauded for its ability to create a common experience for all its viewers.
Since replacing radio as the most popular mass medium in the 1950s, television has played such an integral role in modern life that, for some, it is difficult to imagine being without it.