by Nikolaj Lund
From all the years that have come, television is probably the first most advanced projects in the United States. About 98% of people in the US at least one television set. The average family watches television for seven hours per day, which helps to explain why advertisers love television. Not just advertisers, the tv can also be used for education for children. That way television is not only for entertainment but also kind of like a small school.
One of first people to make that project true was Paul Nipkow. Paul Nipkow was a German inventor, who made the first raw television in 1884. His television system used a disk with small holes to pick up image fragments and put them on a tube. Another person who tried to make the television was a man named Wilhelm hallwachs (in 1888). What he did was that he applied cells in cameras which were demonstrated as devices for reassembling the images at the receiver by the people of Russia. A third person who tried was a person named Campbell Swinton, he was from Scotland, working by himself in 1907 also made a crude kind of a tv, but didn’t get it. Countless radio Anchors including Thomas Edison invented methods of broadcasting tv signals.
The development of the television happens over many years. In fact it took about 150 years to make it. Their were all these inventors who tried to make it and used each others notes. But the person who finally got it was 21 years old Philo T Farnsworth in September 1927, 43 years after Paul Nipkow’s disk. The first thing on the air was a speech from the president at the time, Franklin D Roosevelt.
Franklin D Roosevelt was on the air at the World's Fair in New York. The show only broadcast to a handful of television sets in the area, and his speech was about the Great Depression. He was on a lot of radio so he was used to talking on people that was not face to face. Although, Franklin D Roosevelt was in a wheelchair because of Polio which was a disease back then that would take away your ability to walk. He wanted to keep that knowledge away from the people of the United States, so being on tv was pretty hard since he wanted to keep it a secret.
In the same century, Charles F. Jenkins, an American inventor also made a real television set by combining Paul Nipkows disk with amplifiers. The 1920s were critical years in television development because a number of major corporations including AT&T began serious television research. By 1935, mechanical systems for transmitting images were replaced by electronic methods that could make hundreds of horizontal bands (525) at 30 frames per second. Philo T. Farnsworth and Allen B. Dumont, both Americans, developed a tube that became the face of television by 1939.
Charles Jenkins also made contributions to transmission study during the 1920s. During 1922-23, he constructed mechanical disc scanners to transfer images. These disk focused and reflected light through disks into the edges of glass discs. As the discs rotated, a point of light scanned across a surface. This made electrical signals ready to move. In 1922 Jenkins sent photographs from the phone, and the next year images were being sent to television.
Charles Jenkins publicly broadcasted moving pictures with equipment in 1925. His first 10 minute broadcast showed in silhouette moving. By 1931, he had television stations operating in New York and Washington D.C. He sold receiver kits to people that wanted to watch his broadcast encouraged participation. With other companies, Jenkins contributed to a small, short lived mechanical television ‘boom’. By 1933, however, the poor image quality of scanning convinced larger manufacturers to continue the possibilities of technologies, and the mechanical television era ended.
About 30 years later, CBS had entered the color TV competition and battled with the RCA (Radio Corporation of America) to discover and invent color television. Initially with mechanical methods until an all-electronic color system could be made. Rival broadcasts appeared throughout the 1940s although the competition was slowed by both World War II and the Korean War. The first CBS color broadcast in June 1951, featured Ed Sullivan and other members of the network. Commercial color television broadcasts were underway in the United States by 1954.
Television actually just a receiver. It works by having satellites providing the actual content and the tv just broadcasts it. The US television screen has 525 horizontal lines that are put onto screens with a ratio. 30 images per second are each broken in to the 525 lines and then scanned onto the tv. After that the content that is on is put into the screen.
The television consists of principle sets of parts. Including the exterior, the audio, reception and speaker system, the picture tube, and a electronics including cable. A television set is made of plastic, although wood cabinets are still available for some sets. The picture needs glass, chemicals and electronic attachments. The antennae is made out of metal and used to get better quality.
The design of the television requires input on the part of a range of design engineers. Audio, video, plastics, fiber optics, and electronics engineers all are needed in a new television design. A new design of television may have one or many new of technology as features. It may only be a different size of, or it may include new features such as an improved sound system, a remote control that also controls other devices, and an improved screen or picture, such as the flat black screens that have been put on the marketplace recently.
Plans for the new set are produced by a team of engineers. The concept may change and be redrawn many times before the design is approved for manufacture. The engineers then select and design the components of the set, and a prototype is made to prove out the design. The prototype is not only for confirming the design, appearance, and function of the set, but also for production engineers to determine the production processes, machining, tools, robots, and modifications to existing production lines that also have to be designed or modified to fit the
Almost all television housings are made of plastic by the process of molding, in which molds are made and liquid plastic is injected under high pressure to fill the molds. The pieces are released from the molds, trimmed, and cleaned. They are then assembled to complete the housing. The molds are designed so that brackets and supports for the various components are part of the housing. The television picture tube, or cathode ray tube, is made of glass that is shaped to have a slightly curved at the front or screen. It may also have a added glass, either during production of the glass or by application directly to the inside of the screen. Darker plates produce improved picture contrast. When the tube is manufactured,is allowed to settle on the inside of the face plate, and this coating is then overlaid with a thin film of aluminum that lets electrons pass through. The aluminum serves as a mirror to prevent light from bouncing back into the tube.
Glass for picture tubes is supplied by a limited number of manufacturers in Japan and Germany. Quantities of the quality of glass needed for picture tubes are limited, and the emergence of large screen sets has created a shortage in this portion of the industry. The large screens are also very heavy, so flat-panel displays using plasma addressed liquid crystal displays were developed in the 1980s. This gas plasma technology uses electrodes to layers of neon or magnesium so they release radiation that activates the on the back of the television screen. Because the gas is trapped in a thin layer, the screen can also be thin and lightweight. Projection TVs use digital mirror devices to project their picture
A mask with 200,000 holes lies behind the screen, the holes are precisely machined to align the colors emitted by three beams. Today's best picture tubes have masks that are manufactured from Invar; lesser quality sets have masks of iron. The tube to operate at a higher temperature without distorting the picture, and higher temperatures allow brighter pictures. Rare earth elements have also been added to the coating inside the tube to improve brightness.
The electrons are fired by three tubular, metal electron guns that are carefully seated in the neck, or narrow end, of the tube. After the electron guns are placed inside the tube, the picture tube is evacuated to a near vacuum so air does not interfere with the movement of the electrons. The small opening at the rear of the tube is sealed with a fitted electrical plug that will be positioned near the back of the set. A deflection yoke, consisting of several electromagnetic coils, is fitted around the outside of the neck of the picture tube. The coils cause pulses of high voltage to direct the scanning electron beams in the proper direction and speed
The housing also contains fittings for speakers, wiring, and other parts of the audio system. The speakers are usually made by a specialized manufacturer to the specifications of the television manufacturer. so they are assembled in the set as components or a sub-assembly. Electronic sound controls and integrated circuitry are assembled in panels in the set as it travels along the assembly line.
When the picture tube and the audio speakers and attachments are assembled in the set, other electronic elements are added to the rear of the set. The antennae, cable jacks, other input and output jacks, the electronics for receiving remote control signals, and other devices are prepared by s contractors or as sub assemblies elsewhere on the assembly line. They are then mounted in the set, and the housing is closed. As with all devices, quality control for the manufacture of the television is a rigid process. Inspections, laboratory testing, and field testing are performed during the development of prototypes and throughout manufacture so the resulting television is not only technologically sound but safe for use in homes and businesses.