Controlling The Concentration Of Black Toner; Outline; Controlling The Supply Of Black Toner - Canon CLC 1120 Service Manual

D. Controlling the Concentration of Black Toner

1. Outline

The concentration of black toner is measured, the density of the sample image on the
photosensitive drum is measured, and the change in toner concentration is computed to determine
the amount of black toner to supply (in terms of a length of time). The amount of toner supplied by
the hopper is controlled to suit the change in toner concentration detected this way.
To enable measurement of the concentration of color toner, further, a sample color image is
formed on the photosensitive drum and measured. (See p. 6-34.)
Item
Measuring the concentration
Controlling the initial concentration
(reference concentration)
Measuring the concentration of toner
Controlling the supply of toner
Controlling LED deterioration

2. Controlling the Supply of Black Toner

The density of a black image developed on the photosensitive drum is measured, the change in
concentration is computed, and the result is used to correct the amount of black toner to supply.
COPYRIGHT © 1999 CANON INC.
Table 6-404
CANON CLC1120/1130/1150 REV.0 MAR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 6 IMAGE FORMATION SYSTEM
Description
Light is directed to a sample image, and the reflected
light is measured (photo detection).
The concentration of a sample image is measured
at time of installation or replacement of developer.
The concentration of the sample image during
copying operation is measured.
Compares the initial concentration and the
concentration during copying operation to determine
the amount of toner to supply.
Light coming directly from the LED is measured by
the photodiode used to generate the reference signal,
detecting the degree of deterioration in the intensity
of the LED (at all times).
6-35