Television Technology

1. Television Technology By: Andrew Nichol To: Mr. Churchill Date: Sept. 09/13

2. The HDTV Mandate! • High-definition television in the United States was introduced in 1998 and has since become increasingly popular. Dozens of HD channels are available in millions of homes and businesses both terrestrially and via subscription services such as satellite, cable and IPTV. In June 2011, Nielsen Media Research reported that 75.5 million American homes (two-thirds of all homes) contain at least one HDTV.

3. The Flat Screen Takes over! • Flat panel displays encompass a growing number of electronic visual display technologies. They are far lighter and thinner than traditional television sets and video displays that use cathode ray tubes (CRTs), and are usually less than 10 centimetres (3.9 in) thick. • The first-ever flat panel display was invented in 1964 at the University of Illinois. The first-ever active-matrix addressed display was made by T Peter Brody's Thin-Film Devices department at Westinghouse Electric Corporation in 1968.

4. Color Television! • In its most basic form, a color broadcast can be created by broadcasting three monochrome images, one each in the three colors of red, green and blue (RGB). When displayed together or in rapid succession, these images will blend together to produce a full color image as seen by the viewer. • One of the great technical challenges of introducing color broadcast television was the desire to conserve bandwidth, potentially three times that of the existing black-and-white (B&W) standards, and not use an excessive amount of radio spectrum.

5. The First Major Television Network! • A television network is a telecommunications network for distribution of television program content, whereby a central operation provides programming to many television stations or pay TV providers. Until the mid-1980s, television programming in most countries of the world was dominated by a small number of broadcast networks. Many early television networks (e.g., the BBC, NBC or CBC) evolved from earlier radio networks.

6. The First Ever TV Show! • W3XK is widely regarded as the oldest television station in the United States, possibly in the entire world.[citation needed] It was operated by Charles Jenkins of Charles Jenkins Laboratories from July 2, 1928 to 1934. It was the first station to broadcast to the general public. The station's frequency started out at 1605 kHz, but moved to 6420 kHz (6.42 MHz), and eventually moved to the 2.00-2.10 MHz Frequency. It broadcast from Wheaton, Maryland, just outside of Washington, DC, at a resolution of just 48 lines. The way to view television at the time was by Mechanical television sets, and this station operated in that way.

7. John Baird! • The television pioneer created the first televised pictures of objects in motion (1924), the first televised human face (1925) and a year later he televised the first moving object image at the Royal Institution in London. His 1928 trans-Atlantic transmission of the image of a human face was a broadcasting milestone. Color television (1928), stereoscopic television and television by infra-red light were all demonstrated by Baird before 1930. He successfully lobbied for broadcast time with the British Broadcasting Company, the BBC started broadcasting television on the Baird 30-line system in 1929. The first simultaneous sound and vision telecast was broadcast in 1930.

8. Paul Nipkow! • In 1873, the photoconductive properties of the element selenium were discovered, the fact that selenium's electrical conduction varied with the amount of illumination it received. Paul Nipkow created a rotating scanning disk camera called the Nipkow disk, a device for picture analyzation that consisted of a rapidly rotating disk placed between a scene and a light sensitive selenium element. The image had only 18 lines of resolution.

9. Alexander Graham Bell! • The photophone was similar to a contemporary telephone, except that it used modulated light as a means of wireless transmission while the telephone relied on modulated electricity carried over a conductive wire circuit. • The brightness of a reflected beam of light, as observed from the location of the receiver, therefore varied in accordance with the audio-frequency variations in air pressure—the sound waves—which acted upon the mirror.

10. George Carey! • The first used an array of selenium photocells and wires to transmit an image to an array of light, which were then used to expose a piece of photographic paper. The photograph could then be developed to create a single image. • The second invention used a large array of photocells and wires to transmit the signal to a visual display made of many individual lights. Although this approach should work in theory, each individual pixel requires its own photocell and wired circuit, making this system cumbersome and expensive for producing even a modest size image.

11. Abbe Giovanna Caselli! • Pantèlègraph is a makeup word from "pantograph", a tool that copies words and drawings, plus "telegraph", an electromechanical system that sends messages through a wire over long distances. While Caselli was teaching physics at the University of Florence he devoted much of his research in the technology of telegraphic transmission of images as well as simple words. Alexander Bain and Frederick Bakewell were also working on this technology. Casellideveloped an electrochemical technology with a "synchronizing apparatus" (regulating clock) to make the sending and receiving mechanisms work together that was far superior to any technology Bain or Bakewell had.