Television Dr inż. ZDZISŁAW PÓLKOWSKI Polkowice, 2015 University of Pitesti Dolnośląska Wyższa Szkoła Przedsiębiorczości i Techniki w Polkowicach Simedre Mirel-Adrian

What isTelevision? Television is a way of sending and receiving moving images and sounds over wires or through the air by electrical impulses. The big breakthrough in technology was the ability to send sound and pictures over the air. The word television comes from the Greek prefix tele and the Latin word vision or “seeing from a distance.” The TV camera converts images into electrical impulses, which are sent along cables, or by radio waves, or satellite to a television receiver where they are changed back into a picture. As with most inventions, television’s development depended upon previous inventions, and more than one individual contributed to the development of television, as we know it today.

The Birth of Television Electronic television was first successfully demonstrated in San Francisco on Sept. 7, The system was designed by Philo Taylor Farnsworth, a 21-year-old inventor who had lived in a house without electricity until he was 14. While still in high school, Farnsworth had begun to conceive of a system that could capture moving images in a form that could be coded onto radio waves and then transformed back into a picture on a screen. Boris Rosing in Russia had conducted some crude experiments in transmitting images 16 years before Farnsworth's first success. Also, a mechanical television system, which scanned images using a rotating disk with holes arranged in a spiral pattern, had been demonstrated by John Logie Baird in England and Charles Francis Jenkins in the United States earlier in the 1920s. However, Farnsworth's invention, which scanned images with a beam of electrons, is the direct ancestor of modern television. The first image he transmitted on it was a simple line. Soon he aimed his primitive camera at a dollar sign because an investor had asked, "When are we going to see some dollars in this thing, Farnsworth?"

How Television Works? The first principle is this: If you divide a still image into a collection of small colored dots, your brain will reassemble the dots into a meaningful image. This is no small feat, as any researcher who has tried to program a computer to understand images will tell you. The only way we can see that this is actually happening is to blow the dots up so big that our brains can no longer assemble them. The human brain's second amazing feature relating to television is this: If you divide a moving scene into a sequence of still pictures and show the still images in rapid succession, the brain will reassemble the still images into asingle, moving scene.

Additive Color: the RGB Color System If we are working on a TV, the colors we see on the screen are created with light using the additive color method. Additive color mixing begins with black and ends with white, meaning that as more color is added, the result is lighter and tends to white. The RGB color system is an example the light primaries and creates color with light. Percentages of red, green, & blue light are used to generate color on a computer screen. The basic colors of light are red, green and blue.

Subtractive Color: Red Green Blue Subtractive color is created when light is reflected off a surface. Pigment colors are created through such reflected light. As with the actual red apple, a painted red apple appears when the red wavelengths of light are reflected while the other colors are absorbed. When we mix colors using paint, or through the printing process, we are using the subtractive color method. Subtractive color mixing means that one begins with white and ends with black; as one adds color, the result gets darker and tends to black. In subtractive color, red, yellow and blue are the 3 basic primary colors. These primaries are the pure colors which can not be created by mixing any other colors. Secondary hues are the result of mixing any of the two primaries. Tertiary colors result from mixing the secondary hues.

Color Television History The Development of Color Television A German patent in 1904 contained the earliest recorded proposal for a color television system. In 1925, Zworykin filed a patent disclosure for an all-electronic colour television system. Both of these systems were not successful, however, they were the first for color television. A successful color television system began commercial broadcasting, first authorized by the FCC on December 17, 1953 based on a system designed by RCA. "Between 1946 and 1950 the research staff of RCA Laboratories invented the world's first electronic, monochrome compatible, color television system." - From IEEE Milestone Plaque. quite true to life, the first program was a success.

Inventors and Their Contributions Charles Francis Jenkins - In May of 1920, Jenkins introduced prismatic rings that would replace the shutter on a film projector (Early Television Museum). Allen B. DuMont - In the 1920’s, DuMont developed a cheaper version of the cathode ray tube (CRT), which would last for thousands of hours - much longer than the German version of the CRT, which would only last for 25 to 30 hours (Early Television Museum).

Vladimir Zworykin - In December of 1923, Zworykin applied for a patent for the iconoscope, which would scan pictures to produce images. He later developed a new tube called the kinescope, which is the basis of modern day televisions. The first entirely electronic television system was formed using these two inventions (Early Television Museum). John Logie Baird - In 1924, Baird was able to transmit simple face shapes using a mechanical television (Early Television Museum). Dr. E.W. Alexanderson - On June 5, 1924, Alexanderson was able to transmit a facsimile message across the Atlantic Ocean for the first time. In 1927, Alexanderson used high frequency neon lamps and a perforated scanning disk to demonstrate the first home reception of the.