Operating Precautions And Recommendations; About Pseudo-Contour; Cautions - Pioneer PDP-501MX Technical Manual

About the Pseudo-Contour
6.1 About the Pseudo-Contour
When images representing a series of different brightness or color tones (such as human skin tones) move at a certain
speed, they are sometimes accompanied by striped shadows. This pattern is known as pseudo-contour.
This phenomenon is an optical illusion deriving from the plasma display's characteristic tone wedge, and is not found
with still images.
Using our new driver method, we've succeeded in significantly reducing pseudo-contour, making it possible to achieve
quality video, particularly for motion pictures.
However, this phenomenon may appear when
• MP mode is switched OFF for PC input
• A 1028 x 768, 87-Hz (interlaced) signal is supplied, whether MP mode is switched OFF or ON.

6.2 Cautions

1) If the display shuts down on its own and will not power up again for some time, an abnormal condition (parts
breakdown, for example) is the likely cause. Turn off the main power switch for the plasma display and switch it on
again after waiting several seconds. If the display shuts down, it needs to be repaired. If it remains powered up,
there is no problem, and you may continue using it.
2) Displaying the same images (still images, telops, etc.) for extended periods may cause them to be burned on to the
screen. You can avoid this problem by remaining aware of the software content in use, playback method, system
configuration, and other factors.
3) The following signals may damage the screen:
• Multifold-generated copy of VTR signals
• Copyright-protected VTR signals
• Scrambled CATV signals
• Signals with significantly phase-shifted sync and video signals
4) Images are blacked out for approximately one to three seconds when input is switched, to permit the plasma display
driver to temporarily suspend operation while video memory to refresh. When you switch input between different
frequencies, a longer black-out interval is needed (approximately up to three seconds) due to the array of data to be
changed in video memory. Allow for this interval when "staging" video.
5) The fan will begin spinning faster as ambient temperature rises beyond 25°C. This is normal.
6) About the plasma panel's screen-saver feature (Detection of still images)
Brightness will drop slightly when photo images or slow-moving images, such as those supplied by PCs, are shown
for extended periods. The unit detects the lack of motion and automatically dims the screen brightness to protect
the plasma display panel. This is normal and does not indicate a problem.
The feature generally kicks in approximately five minutes after powering-up or switching input in Normal operating
mode. This feature does not function in RS-232C adjustment mode (AJY) or in Integrator mode.
7) Software problems
We have encountered the following problems with the microcomputer software version 5435A:
• The still-image detector functions in RS-232C adjustment mode (AJY) = Make adjustments while performing
• The still-image detector does not function after exiting Integrator mode = Switch power off, then switch it back
We apologize for these problems. You may compensate for them using the methods described above.
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<AJN> every five minutes.
on after exiting Integrator mode.