Television Earns Pair of IEEE Milestones

Learn about the history of two TV developments that recently earned IEEE Milestones in Electrical Engineering and Computing

6 November 2009

The TV set has become a standard household appliance for many. It’s estimated that about 2 billion people around the world own at least one television. Two early achievements that helped make the television the popular device it is today are being honored with IEEE Milestones in Electrical Engineering and Computing: the development of electronic television and the first transpacific TV signal telecast via satellite.

The development of television is credited to a number of individuals. These latest Milestones honor breakthroughs made by Japanese innovators.

SPINNING DISK
The first recognizes Kenjiro Takayanagi, whose work from 1924 to 1941 helped pave the way for the development of modern television in Japan. He built the world’s first all-electronic TV system. Although Takayanagi didn’t receive much global recognition, he is known as “the father of Japanese television.”

The first TV sets depended on a mechanical device. German inventor Paul Nipkow received the first patent for a TV-like machine in 1884. It was actually a hybrid system of mechanical and electromechanical components. It was referred to as mechanical TV only after the development of all-electronic systems. The distinguishing feature of mechanical TV is the Nipkow disk, which had a series of holes arranged in a spiral. To transmit an image, an electric motor would spin the disk, and bright light would be sent from the camera through each hole to focus on a different part of the subject being broadcast. Photoelectric cells would transform the lines of light reflected off the subject into electrical signals, which were then sent to a receiver. At the receiver, the signals were converted back into lines of light. A complete picture of the subject was produced by a stack of lines, which appeared to the viewer as a continuous picture because of a phenomenon known as the persistence of vision. Images tend to remain in the brain for a fraction of a second after they are perceived.

But mechanical TV had several problems. Very bright light was needed to produce a strong enough electrical signal for transmitting the images. Nevertheless, the broadcast appeared so dimly on the receiver that images could be viewed only in a darkened room. By the mid-1920s, Takayanagi and other engineers had begun researching a better alternative.

Electronic television works by broadcasting moving pictures out of a fast stream of still pictures, each one slightly different from the one before it. A TV camera breaks each still picture into tiny lines and pixels and sends them to a transmitter that converts them to signals and sends them to a receiver. The signals control an electron gun in the receiver that shoots out electrons, which hit a picture tube coated with phosphors, causing them to glow. The gun sweeps across the screen, hitting row after row of phosphor pixels with electrons. It all happens so quickly that it appears as one continuous picture to the human eye.

In 1924, Takayanagi, who taught at Hamamatsu Technical College (now the Faculty of Engineering at Shizuoka University), began experimenting with electronic television. He had become interested in the medium after reading about it a few years earlier in a French magazine. He developed a system using a Nipkow disk to scan a subject and generate electric signals. However, unlike others, Takayanagi took the pioneering step of using a cathode ray tube to display the received signal. On 25 December 1926, Takayanagi successfully demonstrated his system at his school by transmitting a Japanese katakana character. In 1935, he developed Japan’s first all-electronic television.

A ceremony is scheduled for 12 November at Shizuoka University, with a plaque to be placed beside a bronze statue of Takayanagi in front of the university’s Electronics Research Institute. The inscription reads:

“Professor Kenjiro Takayanagi started his research program in television at Hamamatsu Technical College (now Shizuoka University) in 1924. He transmitted an image of the Japanese character イ(i) on a cathode-ray tube on 25 December 1926 and broadcast video over an electronic television system in 1935. His work, patents, articles, and teaching helped lay the foundation for the rise of Japanese television and related industries to global leadership.”

TRANS-PACIFIC SIGNALS
Today we can watch live TV pictures from around the world. But more than 45 years ago, video clips from opposite ends of the Earth had to be transported on airplanes, taking days to be broadcast. The second IEEE Milestone honors a breakthrough that helped change that.

In the early 1960s, telecommunications between the United States and Japan relied on narrow-band coaxial submarine cables and high-frequency radio signals. In 1962, the first successful transatlantic TV relay—between Maine and England—was made via the Telstar 1 telecommunications satellite. The transmission, which also earned an IEEE Milestone, created a craving in Japan for transpacific satellite communications—especially because the country was preparing for the 1964 Summer Olympics in Tokyo and hoped to broadcast the events around the world. Government officials and engineers from Japan’s major telecommunications companies, including KDD (now KDDI), Nippon Telegraph and Telephone, NEC, and Mitsubishi Electric, teamed up to build the country’s first satellite communications center to televise the Olympics. In 1963, the engineers completed the Ibaraki Satellite Communication Center, which communicated with NASA’s Relay 1 satellite via the world’s first Cassegrain antenna.

The first U.S.-Japan satellite telecast from the center took place that year, on 23 November. It was to be a prerecorded address from U.S. President John F. Kennedy to the Japanese people. Tragically, Kennedy was assassinated, so an announcement of his death was the first transmission. Almost a year later, the Olympics were successfully broadcast from Japan to the rest of the world.

The Ibaraki center continued to play a key role for decades as the gateway for communications between Japan and the United States as well as countries along the Pacific Rim. In the late 1990s, satellite communications gave way to underwater high-capacity fiber-optic systems.

A ceremony is scheduled for the anniversary of the TV signal transmission—23 November—and a plaque is to be placed in the Ibaraki center’s exhibition hall. The plaque’s inscription says:

“On 23 November 1963, this site received the first transpacific transmission of a TV Signal from Mojave earth station in California, U.S.A., via the Relay 1 communications satellite. The Ibaraki earth station used a 20m Cassegrain antenna, the first use of this type of antenna for commercial telecommunications. This event demonstrated the capability and impact of satellite communications and helped open a new era of intercontinental live TV programming relayed via Satellite.”

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