Nipkow, now considered the forefather of the television age, received little recognition for his contribution during his lifetime. Italian physicist Guglielmo Marconi demonstrated a device that could transmit an audio signal in the late 1890s. Nipkow was born on August 22, 1860, in Lauenberg, Germany. Inspired by the work of Marconi, Nipkow began thinking about the challenge of transmitting a visual image while still a student in Germany. It was well known that any successful transmission device required three essential components: a device to translate the visual image into an electronic impulse, a second device to reassemble that impulse into an image, and a third device by which to transmit the impulse from the first device to the second. In 1884, even before completing his degree, Nipkow had developed and patented a transmissions system that achieved all three requirements.
Nipkow's television was based upon an ingenious device called a Nipkow disk, which was a metal or cardboard disk that was perforated with twenty square holes arranged in a spiral so that each hole was a little closer to the center than the last. As Nipkow spun the disk, he shined a strong light through the holes and onto the subject. Because each hole was slightly offset, the image was scanned in a series of twenty horizontal lines.
In order to translate these lines into an electrical signal, Nipkow employed a selenium photoelectric cell (a device with which he had previously worked with extensively). The cell recorded the light and dark areas within each of the twenty scanned lines, converting these into a transmittable signal. In order to view the signal, Nipkow essentially reversed the process. He used a light source that flashed brightly or dimly according to the incoming signal. To this he added a second scanning disk, placed in front of the flashing light and synchronized with the first disk, so that the light shone through the holes and projected twenty scanned lines onto a screen.
The main drawback to Nipkow's invention was not its design but its timing: the concept of television was so advanced that no producer or investor could envision a practical use for it. Though Nipkow used his device to transmit a visual image via telegraph wire from London to Paris, his mechanical television never quite caught on. Nipkow himself eventually abandoned electronics and spent the rest of his life as a railway engineer. He died in Berlin, Germany, on August 24, 1940.
It was not until 1929 that another scientist, the Scottish engineer John Logie Baird, made certain improvements upon the Nipkow design and reintroduced it to the world. While Baird's design was still essentially mechanical, it came at a time when the world was ready to embrace the concept of television. Photomechanical televisions were soon replaced by completely electronic devices, but even today's models rely upon the horizontal-scanning method first conceived of by Nipkow.
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