Image pickup device development - from image pickup tube to CCD
Although the iconoscope was an epoch-making invention, the later image-orthicon (developed by RCA in 1946) was actually what was needed for TV to advance. The image orthicon has a sensitivity 100 times higher than that of the iconoscope. Small image pickup tubes, including the Plumbicon and the Saticon, spurred development of color TV and miniaturized cameras. Since the mid 1980’s, the most common image pickup device has been the CCD. Backed by the semiconductor industry, CCD capabilities advanced rapidly, eventually resulting in the present small high-performance cameras.
Appearance of high-sensitivity image pickup tube
Iconoscope |
STRL’s image-orthicon |
Although the iconoscope was an epoch-making invention, the later image-orthicon (developed by RCA in 1946) was actually what was needed for TV to advance. The image orthicon has a sensitivity 100 times higher than that of the iconoscope. Small image pickup tubes, including the Plumbicon and the Saticon, spurred development of color TV and miniaturized cameras. Since the mid 1980’s, the most common image pickup device has been the CCD. Backed by the semiconductor industry, CCD capabilities advanced rapidly, eventually resulting in the present small high-performance cameras.
Appearance of high-sensitivity image pickup tube
During sensitivity studies on the generation of a phototransistor-like amplification effect within a photoconductive film, an avalanche-multiplication phenomenon was observed that was unexplainable by the conventional image pickup theory. This discovery resulted in the development of the highly sensitive HARP image pickup tube. A high-sensitivity camera using this image pickup tube produces clear video images in the dark, and has been employed in reporting breaking news and in the shooting of aurora phenomena.
Source and Credit :- http://www.nhk.or.jp/strl/aboutstrl/evolution-of-tv-en/p13/column/index1.html
Contributed by :- Shri. D Narayana Swamy,dns_v@yahoo.com