Editing Cathode-ray tube (section)

====Limits imposed by deflection====
At high deflection angles, resolutions and refresh rates (since higher resolutions and refresh rates require significantly higher frequencies to be applied to the horizontal deflection coils), the deflection yoke starts to produce large amounts of heat, due to the need to move the electron beam at a higher angle, which in turn requires exponentially larger amounts of power. As an example, to increase the deflection angle from 90 to 120°, power consumption of the yoke must also go up from 40 watts to 80 watts, and to increase it further from 120 to 150°, deflection power must again go up from 80 to 160 [[watt]]s. This normally makes CRTs that go beyond certain deflection angles, resolutions and refresh rates impractical, since the coils would generate too much heat due to resistance caused by the [[skin effect]], surface and [[eddy current]] losses, and/or possibly causing the glass underneath the coil to become conductive (as the electrical conductivity of glass increases with increasing temperature).{{cn|date=December 2024}} Some deflection yokes are designed to dissipate the heat that comes from their operation.<ref name="auto38"/><ref>{{cite thesis |last1=Harberts |first1=D. W. |title=Dissipation and ringing of CRT deflection coils |date=2001 |url=https://research.tue.nl/en/publications/dissipation-and-ringing-of-crt-deflection-coils }}</ref><ref name="auto99"/><ref>{{Cite web|url=https://www.freepatentsonline.com/5204649.html|title=Deflection yoke|accessdate=18 December 2022}}</ref><ref>{{Cite web|url=https://patents.google.com/patent/US6650040B2/en|title=Cathode ray tube having a deflection yoke with heat radiator|accessdate=18 December 2022}}</ref><ref>{{cite journal |last1=Masuda |first1=Y. |last2=Akiyama |first2=T. |last3=Kitaoka |first3=M. |last4=Otobe |first4=S. |last5=Takei |first5=H. |last6=Kitaoka |first6=M. |title=23.2: Development of New Ferrite Material for Deflection Yoke Core |journal=SID Symposium Digest of Technical Papers |date=1998 |volume=29 |issue=1 |pages=343 |doi=10.1889/1.1833763 |s2cid=137042132 }}</ref> Higher deflection angles in color CRTs directly affect convergence at the corners of the screen which requires additional compensation circuitry to handle electron beam power and shape, leading to higher costs and power consumption.<ref>{{Cite web|url=https://www.extremetech.com/electronics/53826-crt-innovations/3|title=CRT Innovations - Page 3 of 7 - ExtremeTech|website=www.extremetech.com|access-date=8 December 2020|archive-date=8 October 2020|archive-url=https://web.archive.org/web/20201008230709/https://www.extremetech.com/electronics/53826-crt-innovations/3|url-status=dead}}</ref><ref>{{Cite web|url=https://www.latimes.com/archives/la-xpm-2005-sep-14-fi-tubes14-story.html|title=Samsung Refusing to Pull Plug on CRT Televisions|first1=Elliot|last1=Spagat|date=September 14, 2005|website=Los Angeles Times}}</ref> Higher deflection angles allow a CRT of a given size to be slimmer, however they also impose more stress on the CRT envelope, specially on the panel, the seal between the panel and funnel and on the funnel. The funnel needs to be long enough to minimize stress, as a longer funnel can be better shaped to have lower stress.<ref name="auto34"/><ref>{{cite web |url=https://www.koreascience.or.kr/article/CFKO200524282635548.pdf |archive-url=https://web.archive.org/web/20210706120621/https://www.koreascience.or.kr/article/CFKO200524282635548.pdf |archive-date=2021-07-06 |url-status=live |title= The Design of Glass for Vixlim |website=www.koreascience.or.kr |access-date=2020-12-11}}</ref>