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IN1401 Operation Manual - v1.5 7/12/02 11:18 AM
© 2002 - INLINE, Inc.
In Figure 3, the active area is adjusted incorrectly, as shown by the dashed lines. If the active pixels are set less
that the actual active pixels, the IN1401 will only look for the active area inside this smaller region. This results
in an active area containing fewer pixels than are really present. This gives the apparent effect that the picture is
stretched horizontally. Similarly, if the active lines are set less than the actual active lines, the IN1401 will again
only look for the active area inside the smaller region. This results in an active area containing fewer lines than
are really present. This gives the apparent effect that the image is stretched vertically.
Blanking
Active Area
Active Pixels
Ac
tiv
e
Lin
e
s
Incorrect Active
Figure 3. Incorrect Active Area
Depending on the video source, the following input modes may have the same horizontal scan rate and
vertical refresh rate. The differences between these input modes will not be detected. The input aspect
ratio will automatically be maintained at the output by inserting blank borders around the image. However,
if you want to fill the entire monitor, the input aspect ratio may be set by adjusting the active pixels or
active lines, according to the input mode. This will stretch the image to fill the entire monitor. The total
pixels may also be adjusted to match the input mode as shown in the tables below:
Table 1. Input Modes for Horizontal Scan Rate = 31.5 KHz and Vertical Refresh Rate = 60 Hz
Active Pixels
Active Lines
Aspect Ratio
Total Pixels
640 480 4:3 780
(progressive
NTSC)
640 350 64:35 800
640 400 8:5 800
640 480 4:3 800
(factory
default)
720 350 72:35 900
720 400 9:5 900
Table 2. Input Modes for Horizontal Scan Rate = 15.7 KHz and Vertical Refresh Rate = 60 Hz
Active Pixels
Active Lines
Aspect Ratio
Total Pixels
768 480 8:5 910
NTSC
14.3
720 480 3:2 858
NTSC
13.5
640
480
4:3
780
NTSC 12.3 (default)
