Loewe Q2500B Serviceanleitung Seite 229

Technology of Q 2500 colour TV set
VPC 3233 /I 2151 and the PIP memory I
2161/71 The video processor PIP is the same
IC type as the main video processor I 2271.
With the VPC 3233 various PIP representa-
tions are possible. Our device controls support
3 PIP representations.
Split Screen
The screen is split into two halves. On the left
side the half picture is displayed and on the
right side the picture of the PIP electronics.
Both pictures are the same size and quality. In
the horizontal level, sections of a picture on
the left and right are naturally cut off. The core
area, however, is correctly displayed.
PIP small
The picture in picture, which is reduced to 1/9
of its normal size, can be positioned in any of
the four corners.
PIP large
The same is true as for PIP small, only the
size is 1/4 of the normal picture.
For 4:3 devices Split Screen is not possible.
For small and large PIP display the PIP pic-
ture must be correspondingly compressed.
Document Q 2500
This occurs at the vertical level by the interpo-
lation of picture lines. For the small setting, 3
lines are compressed and for large setting 2
lines, and for each a new line is calculated by
interpolation. In the horizontal level these lines
are then compressed accordingly. The writing
of the picture in picture data to the PIP mem-
ory is controlled completely by the PIP-VPC.
Reading from memory is controlled fully from
the main VPC.
Writing to and reading from memory is there-
fore independent. There is no synchronisation
between the two VPC's.
The PIP processor processes FBAS as well
as Y/C signals. The video transfer applies the
FBAS/Y signal to pin 73 and the associated
chroma signal to pin 72. All possible signal
sources can therefore be displayed as PIP.
If an online module is integrated into the TV
set, the picture can also be displayed by the
online module as PIP. The Y/C signal from the
online module reaches the pin connector W
1531 on the signal board. The TVO/Y signal is
applied to pin 74, and the associated chroma
signal to pin 71 of I 2151.
For the basic and medium signal board vari-
ants a single chip PIP processor SDA 9488 is
used.
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