Digital Image Control Qualitative Reasoning Based Adaptive Controller - Panasonic FP-D250 User Manual

1. 10 Digital Image Control Qualitative Reasoning
Based Adaptive Controller
• Even if the toner density is at it's standard level, the copy image may vary with
time depending on the characteristics of the drum and environmental variations.
To prevent this change, the copy density sensor, which is installed to the left of the
drum unit, controls the copy process to stabilize the image.
• Controlling the image
During initialization, after turning on the power, the copy density sensor reads the
medium density and black density marks which are produced electrically using
laser beams on the drum surface.
These two values are compared with the ideal gamma curve stored in the copiers
memory.
The copier detects the amount offset from the standard gamma curve (such as "a
little background" or "light image") and calculates the variables for copy density
control in accordance with Qualitative Reasoning Based Adaptive Controller. In
this way it finds the optimum compensation values to tighten the gamma curve by
changing laser power, and grid voltage for maintaining peak copy quality.
• The control of the gamma curve stabilizes copy quality by monitoring two points of
copy quality (medium density and black density) and has a direct effect on
background, solid area density and good reproduction of fine lines regardless of
environmental changes and variation with time and copy volume.
• Qualitative Reasoning Based Adaptive Controller (Digital QUANTUM)
Qualitative Reasoning Based Adaptive Controller is adaptive control on the basis
of quantitative reasoning theory. While successively reasoning and learning the
change of process characteristics regardless of environmental changes and the
variations with time and the number of copies on the copier, the system reads the
patch marks and determines the best values of laser power and drum surface
potential to establish the best gamma curve for optimum copy quality.
• Qualitative Reasoning Based Adaptive Controller is applied at the following intervals.
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