Refresh rate on CRT

[hitendra_11]

Hello,
hi i m a student of instrumentation science.i m going to give a seminar on display technology.on my second seminar i m taking a CRT.so i want information about shadow mask and refresh rate?

 

[number13]

Google

 

[RetiredChief]

Going back a few years - US and televisions.
525 lines from top to bottom. The lines were scaned at a rate of 60 Hz. Starting at line one then line 3, then line 5 ect to the bottom. It then restarted at the top line 2, then line 4. This was basicly one frame, True refresh was 30 Hz. reason it was called interlaced. Scan was from left to rigtht. Also the decay time of Phosphorus dots came into play.
Added: England whent from 400+ to 600+ and Germany was around 800 I think. Both were better than US, was do to a later date in standarization. Us Did not increase do to consummer cost.

With Computer monitors, you had a choise of interlaced and non-interlaced intially and could go above 60 Hz ie 75 Hz. In noninterlaced the scan just goes from line 1 to line 2 ect.

With LCD this still applies, except you can change all the pixels at the same time. This rate is normally limitted to 60 Hz. The 60 hz is a limitation of the On/off time off the Pixel. Phosphorus has a faster on/off time than LCD crystal. However LCD improvements have decreased this on/off time down to 2 mS

For shadow mask
http://en.wikipedia.org/wiki/Shadow_mask