Crt - Panasonic BT-M1950Y Service Manual

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CRT
1. CRT outline
The cathode ray tube is an in-line dot trio type used in computer displays in order to obtain high resolution. The dot pitch
is 0.40 mm.
A finer dot pitch is related to horizontal resolution. In addition, when the circuit frequency response fully matches the
CRT performance, the horizontal resolution is increased.
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Pa: Dot pitch
Pth: Horizontal pitch
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Pth=--
xPa
2
In this case, the horizontal resolution (TV lines) can be derived by the following formula.
N
=
(Wh/Pth) x (V/H)
Wh : Effective horizontal screen (mm)
Pth: Horizontal dot pitch (mm)
V/H: Screen aspect ratio (3/4)
These are derived as follows.
Horizontal dot pitch (Pih):
Pth=(./3/2)XPa=(./3/2)X0.40=Approx. 0.346
N=(399/0.346)X(3/4)=Approx. 865 TV lines
Althouth the BT-M 1950Y CRT's can produce 865 lines, in practice, due to the monitor frequency response, these
become 750 lines.
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