Ricoh A156 - Page 63

Determination of TSC
TSC is an estimate of the proportion of black area in the image that is made
by the machine.
(1) Detect Supply Mode
In detect supply mode, TSC is determined from outputs from both the TD
and ID sensors, in conjunction with the toner supply ratio that has been
selected for this mode.
- Toner Supply Ratio -
This is selected with SP2-222. The settings are 1 (7%), 2 (15%), 3 (30%), or
4 (60%). The default is 15%.
- TD and ID Sensor Outputs -
The machine calculates a value for V
T
-V
TREF.
•
V
T
: Current TD sensor output
• V
TREF
: TD sensor output at the latest V
SP
detection corrected for ID
sensor output (V
SP
/V
SG
); this is calculated every 10 or so copies (see
V
SP
/V
SG
Detection for more on V
SP
and V
SG
)
.
V
TREF
is determined as follows.
V
TREF
= V
TP
+
∆
V
REF (Formula 2)
•
V
TP
= TD sensor output at V
SP
detection
•
∆
V
REF
= Correction factor based on V
SP
/V
SG
(from the ID sensor
output), determined by the following table.
Table 7.
V
SP
/V
SG
∆ V
REF
[V]
~ 0.075 +4 x 0.0196
0.076 ~ 0.090 +2 x 0.0196
0.091 ~ 0.105
±
0
0.106 ~ 0.125 –2 x 0.0196
0.126 ~ 0.160 –4 x 0.0196
0.161 ~ 0.205 –6 x 0.0196
0.206 ~ 0.500 –8 x 0.0196
0.501 ~ The previous V
TREF
TSC [%] is then determined from V
T
-V
TREF
and the toner supply ratio, as
shown by table 8.
V
SP
pattern
darker
V
SP
pattern
lighter
Detailed
Descriptions
STM 2-15 A156/A160/A162