The Television: A History

This achievement served as the foundation stone for other scientists who emulated and improved upon Baird’s work in the following years. Simultaneously, research had been continuing into the improvement of the design of cathode ray tubes. With the help of the triode, by 1933 it had become possible for the Cathode Ray Tube to be used in receiving equipment. Direct scanning of scenes was not possible using the Cathode Ray Tube since the natural light proved to be too bright. The solution to this was to first shoot the scenes onto a film and then scanning the film using a ‘flying spot’ cathode ray tube. This method was used for many years until improvements were discovered. In 1930 interlaced scanning was introduced in order to improve frame rate without otherwise altering equipment. This involved splitting the lines into two sets; odd and even lines. By alternating their placement on the screen, a doubling of frame rate was achieved. However, this was not without its drawbacks.

The first Public Transmission of Television Signals Baird conceived the first public transmission was conceived in UK during 1929. He was able to convince the BBC to make television broadcasts outside of normal radio program hours, using the existing radio channels. He used a mechanical system of 30 lines with 12 frames per second. No interlacing was used in this early system. The BBC adopted the system as their standard and began transmitting in 1932, despite higher definition systems being available. This first BBC service ran until the 11th September 1935 and had an almost national coverage. A new, higher definition system was introduced in November 1936. This required its own infrastructure, rather than relying on radio channels. This and the expensive new receiving equipment caused coverage to be reduced to the London area.

In 1936 Baird’s 240 line, 25 frame per second mechanical system was in competition with a newly developed electronic system with 405 lines and 25 frames per second. The two systems were used in turn, alternating weeks, and in February 1937, the electronic system was adopted as the standard for the BBC; the Baird system proved to be unreliable since it was pushing the capability of mechanical equipment used.

Although the Second World War affected the expansion of television in Europe, extensive research into related areas continued. This allowed improvements in the cathode ray tube and higher frequency transmitting equipment to be made.

Go To Page: 1 2 3