567-line television system
The 567-line television system was an experimental proposal by Philips of the Netherlands for Europe. The system ran at 50 fields (25 frames) per second.[1]
The first mention of the system appeared in an article from 1938, published in the Philips' technical bulletin, on a transportable demonstration TV station, but no details were provided.[2]
Most of the technology was to be borrowed from NTSC, the difference from NTSC being the reducing of the horizontal scan frequency from 15,750 to 14,175 Hz.[3]
This would have meant that the NTSC sound carrier frequency of 4.5 MHz above the picture carrier, would have also been the standard for Europe, and hence a lot more common worldwide.
System | Lines | Frame rate | Channel bandwidth (in MHz) | Visual bandwidth (in MHz) | Sound offset | Vestigial sideband | Vision mod. | Sound mod | Aspect ratio | Effective resolution (4:3). |
---|---|---|---|---|---|---|---|---|---|---|
567-line | 567 | 25 | 6 | 4.2 | +4.5 | LSB cut @ -0.75 MHz | Neg. | FM | 4:3 | 740 x 485 (theoretical) |
The proposal was defeated as Russian engineers had already shown how NTSC could be easily adapted to a higher resolution by breaking with NTSC bandwidth restrictions, and moving the sound carrier up 2 MHz from 4.5 to 6.5 MHz, along with 625-line scanning.
References
- "Philips Netherland 567 line TV Standard" (in German). Radiomuseum.org. Retrieved 2011-06-20.
- J. van der Mark (January 1938). "A transportable television installation" (PDF). Philips Technical Review. 3 (1): 2.
The installation is suitable for the broadcasting of 25 pictures per second, with 405 or 567 lines per complete picture, while interlaced scanning is employed. (If 567 lines are used, a frequency spectrum must be dealt with which extends from about 50 cycles per second to about 5 × 106 cycles per second, for 405 lines the necessary frequency spectrum extends only to 2.5·106 cycles per second.
- "Philips 567 Zeilen Standard - The Philips 576 line TV system". Scheida.at. 1951-10-02. Retrieved 2011-06-20.