Ricoh Robin Service Manual page 37

OPTICS
3.6.3 V Correction Factor
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The light intensity may decrease because of dust accumulated on the optics
parts. This may cause dirty background on copies. To compensate for this
phenomenon, V correction is done as follows:
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Whenever SP56 (ADS reference voltage adjustment) is performed, before
sampling starts for the ADS adjustment, the auto ID sensor measures the
amount of light reflected through the 1st, 2nd and 3rd mirrors from the white
plate located under the left frame. The photosensor circuit converts this light
intensity to a voltage and the CPU stores it in memory as the initial data.
The machine has a software counter for the V
copies the machine measures the light intensity reflected from the white
plate, and this is compared with the initial data stored in memory.
If the measured voltage difference is/or more than 0.1 volts, +1 will be added
to the exposure lamp data as the V
If the difference is less than 0.1 volts, no correction will be applied.
The total increase for V
optics parts, the following actions must be performed in order.
•
SP95: Clear the exposure lamp data and the software counter
by entering "1".
•
SP48: Perform the light intensity adjustment.
•
SP56: Perform the ADS adjustment (to store the new initial
data and to adjust the ADS reference voltage.)
3.6.4 Reproduction Ratio Correction Factor (A152 copier only)
Reproduction ratio (%)
61 and 62
63 to 119
120 to 129
130 to 141
The exposure lamp data is increased depending on the selected
magnification ratio in order to compensate for the change in the concentration
of light on the drum.
correction factor.
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correction cannot exceed +20. After cleaning the
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Change of exposure lamp data
+2
±0
+2
+4
2-18
correction. At every 500
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24 June 1994