Iconoscope – 1923


IconoscopeThe iconoscope was an early electronic camera tube used to scan an image for the transmission of television. No other practical television scanning device prior to it was completely electronic, although some, such as the Nipkow disc, combined electronic elements with mechanical ones. Within glass housing, the iconoscope contained a photosensitive plate or “mosaic,” which divided the image to be televised into tiny sections called pixels. An electron gun, also placed in the housing, projected a scanning beam of electrons toward the plate. Deflecting coils directed the electron beam, which charged the plate’s pixels. The charge of individual pixels was proportional to the brightness of light initially focused on them, so that the electrical signal produced derived from the original image. From the output of the camera tube, the signal traveled to an amplifier before being transmitted to a receiver.

A Russian-born American, Vladimir Zworykin, invented the iconoscope in 1923. Now commonly referred to as the “father of television,” Zworykin worked at the Westinghouse Electronic Company at the time he filed a patent for the iconoscope. According to the patent, he planned for the device to be part of a completely electronic television system. It would take Zworykin six more years, however, before he could actually construct an effective electronic receiver, which he dubbed the kinescope. The Radio Corporation of America (RCA), the parent company of Westinghouse, funded Zworykin’s television research. In 1939, RCA finally reaped the benefits from their investment when they used Zworykin’s system to broadcast TV to the public for the first time.

In the decades following the iconoscope’s invention, improved camera tubes appeared and gradually replaced Zworykin’s version. Many of them, however, were based on the same basic principles as the iconoscope and featured somewhat similar designs. As TV broadcasting was refined and the technology involved became more affordable, more and more people became familiar with television.

Television eventually became fully integrated into the daily lives of Americans. Today in the United States, people watch more than four hours of TV each day on average, and a typical American household contains at least two television sets. Despite his role in its development, Zworykin, who lived into the early 1980s, became concerned with the direction television had taken and its affect on society. He had hoped TV would serve to educate the public and to broadcast cultural events. Dismayed at the trivial and counterproductive materials often featured on television, Zworykin lamented in his later years, "I hate what they've done to my child ... I would never let my own children watch it."

Last modified on 10 December 2014
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