Moving pictures, color pictures, and high definition pictures were not a concern to the pioneers of television in 1862. However, they did succeed in transmitting an image using a device named a Pantelegraph. The pantelgraph could transmit at a rate of about 15 words per minute which was slower than the telegraph. Transmission would occur one scanning pass at a time. It would send a partial imprint of the image from the sending unit to a receiving unit that would print the image. It operated much like an antique fax machine. A picture was divided into lines of the image and then transmitted. It took several minutes for one image to be sent.
For movement to occur, images would have to follow one another in such rapid succession that the eye would be fooled into seeing motion. Early transmission occurred over wires. In 1907 a cathode ray tube was developed and used to transmit and receive images. By 1925 advances were made so that images were transmitted fast enough to portray a moving silhouette. The inability of a camera to clearly photograph images in motion was a major drawback. During this early period, technology was developed and a patent was issued for the transmission and reception of color images.
In 1926, advances were made that allowed 30 lines of resolution. By this time 30,000 signals per second were being transmitted. It was estimated that for television with motion and clarity to occur, 300,000 images per second would need to be sent and received. These problems were resolved and in 1930, the first commercial broadcast occurred and the BBC began broadcasting. In 1933 Iowa State University began television broadcasting.
A coaxial cable was completed between New York City and Philadelphia in 1936. There was also one completed between Minneapolis and Stevens Point, WI. These cables could carry 480 phone conversations or 1 television program. At this time there were 200 television sets worldwide.
In 1937 the BBC began broadcasting in high definition. However, images and sound were still 2 different problems and in order to coordinate sound and image, television had to be coupled with radio. Advances began to occur rapidly. In 1940 343 lines of resolution on the screen were obtained and in 1941 525 lines occurred. Microwave transmission of the images began in 1945.
By 1946 color television was possible by using a spinning wheel in front of a cathode ray tube. The wheel had panels of red, blue, and green transparencies that when spun in front of the tube produced a colored image. There were 1,000,000 homes with television by 1948. Telstar was the first satellite communication and was used in 1962. In 1970, L5 coaxial cable was used that could transmit 125,000 phone calls or 200+ television show simultaneously.
The first giant screen television was introduced in 1973 and by 1982 televisions existed with 1125 lines of resolution. Beginning in 1993 closed captioning was required by the federal government. In 1996 there were 1,000,000,000 television sets in use.
Developments continue to occur rapidly and holograms are in the future as well as other sensory appeals such as 3D and odors.