Toner Density Adjustment Mode - Ricoh B230 Service Manual

Step 4: Toner Amount Calculation
The machine calculates the amount of toner on the transfer belt that is required to make
each of the 10 grades of the sensor pattern. To do this, the machine uses the output values
of the ID sensor from each grade of the pattern.
2
The amounts of toner are expressed as M/A (mass per unit area, mg/cm )
Step 5: V , V , V Selection and V Adjustment
D B L TREF
The machine determines the relationship between the amount of toner on the transfer belt
and the development bias for each of the 10 grades.
From this, the machine determines the best V to get the target M/A for each color. Then,
D
based on this V , the machine determines the best V and V . This process ensures that
D B L
enough toner is deposited to make black pixels.
The machine also adjusts V (toner density target) at the same time so that the
TREF
development gamma used by the machine fall within the target development gamma range
stored in the machine's software. If it does not fall within this range, the amount of toner
deposited on the latent image will be too high or too low.

6.2.4 TONER DENSITY ADJUSTMENT MODE

If the toner density becomes too high or too low because of an incorrect development
gamma, this is corrected by process control (see the previous section). But sometimes, it
takes many copies before the toner density comes to the correct value.
Toner density adjustment mode can be used to bring the toner concentration to the correct
level much more quickly, if users complain about the toner density.
SP 3-043 controls when the toner density adjustment mode is done.
To do the toner density adjustment mode manually, execute SP 3-011-2.
It is also done automatically before ACC, if SP3-041-4 is set to "2: TC Control" (this is the
default setting).
During this procedure, the machine generates ID sensor patterns and detects the current
development gamma. The gamma must be within ± 0.2 of the target development gamma.
If the current gamma is too high (above the target by 0.2 or more: 0.2 limit is set with
SP3-239-009), the machine consumes toner in the development unit until the development
gamma is within the correct range. To consume toner, the machine generates solid
patterns.
If the current gamma is too low (below the target by more than 0.2: 0.2 limit is set with
SP3-239-012), the machine supplies toner to the development unit until the development
gamma is within the correct range.
B230/B237 6-12 SM