Canon 1180 - Controlling the Concentration of Color Toner; Outline

COPYRIGHT © 2002 CANON INC. CANON CLC1100/1130/1150/1160/1180 REV.2 FEB. 2002 PRINTED IN JAPAN (IMPRIME AU JAPON)
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CHAPTER 6 IMAGE FORMATION SYSTEM
C. Controlling the Concentration of Color Toner
1. Outline
To determine the length of time for color toner supply operation, the concentration of color
toner on the developing cylinder is measured, thereby computing the change in toner density.
Then, the density of the sample image on the photosensitive drum is measured to detect the change
in toner density on the photosensitive drum.
These two items of data are used to determine the amount of toner to be supplied from the
hopper.
Table 6-402 shows the major functions of the color toner concentration mechanism:
Table 6-402
The following shows the flow of operations used to supply color toner:
Item Description
Detecting the concentration Light is directed to the developer, and the reflected light
is measured (photo detection).
Controlling the initial concentration Measures the concentration of the starter developer at
(reference concentration) time of installation or replacement of the developer.
Measuring the concentration of toner Measures the concentration of the developer on the
developing cylinder during copying operation.
Controlling the toner supply operation The target concentration and the concentration during
copying operation are compared to determine the
amount of toner to supply.
Controlling LED deterioration Light coming directly from the LED is measured by the
photodiode used for the generation of reference signals
to find out the degree of deterioration in the intensity of
the LED.
Measuring and generating Measures the density of the sample image on the
the image density on the drum photosensitive drum, and determines the target
concentration of toner.
Computes the change in toner density from two items of data
(concentration on the developing cylinder and on the photo]
sensitive drum) to determine the amount of color toner to supply.
Start key ON
Measures the concentration of toner on the photosensitive drum for
every 10 copies.*
1st copy Measures the concentration of toner on the developing cylinder.
2nd copy Measures the concentration of toner on the developing cylinder.
* 10 copies in CLC1100/1120/1130/1150, 25 copies in CLC1140/1160/1180