Sharp AR-280 Service Manual page 111

AR-405
50
50 - 1 Purpose Adjustment
Function Used to adjust the copy image position and the void area (image loss) on the print paper in the copy mode. (The
(Purpose) same adjustment can be made with SIM 50-2 (simple method).)
Section
Item Picture quality
Operation/ 1. Select the adjustment item with [↑] [↓] keys.
Procedure
2. Enter the adjustment value with the 10-key.
3. Press the [OK] key. (The adjustment value entered in procedure 2 is set.)
(RRC-A)
This set value is used to align the document image lead edge ad the scan image data lead edge in the document
table scan mode.
After starting scanning, the image lead edge position is determined by using the scanner home position detection
signal (MHPS) OFF timing as the reference.
RRC-A set value = Time (distance) from the output of the scanner home position detection signal (MHPS OFF) to the
image lead edge position.
(0 ~ 99: Default value 50)
If this setting is not made properly, the image lead edge position (image loss) varies depending on the copy
magnification ratio.
When the set value is increased, the image position is shifted in the advancing direction on the paper.
When the set value is changed by 1, the image lead edge position is varied by about 0.24mm (about 0.29mm for
AR-4XX series).
(SPF)
This set value is used to align the document image lead edge position and the scan image data lead edge position in
the SPF scan mode.
After starting scanning, the can image lead edge position is determined by using the resist sensor detection signal
(REGS ON) timing as the reference.
RRC-A set value = Time (distance) from the output (resist sensor detection signal (REGS ON) to the image lead edge
position.
(0 ~ 99: Default 50)
If this setting is not made properly, the image lead edge position (image loss) on the copy paper may vary depending
on the copy magnification ratio.
When the set value is increased, the image position is shifted in the advancing direction of the copy paper.
When the set value is changed by 1, the image lead edge position is changed by about 0.1mm.
(RRC-B)
This set value is used to adjust the relative positions of the image position on the OPC drum and the copy paper.
This adjustment is made by adjusting the time from the output timing of the image lead edge signal (LD START
signal) to RRC ON.
At the timing of LD START signal output, the print image is made on the OPC drum at an optional position with the
laser beam.
(0~99: Default 50)
Actually the RRC ON timing is determined as follows:
RRC ON timing = This set value (RRC-B) - Lead edge void set value (DEN-A)
When the set value is increased, the RRC ON timing is delayed, decreasing the led edge void area.
When the set value is changed by 1, the lead edge void area is changed by about 0.17mm (about 0.21mm for
AR-4XX series).
(Note)
The value of RRC-A must be properly set in advance to this adjustment.
(IMAGE LOSS)
This set value (timing adjustment value) is used to determine the lead edge image loss and the image lead edge
reference position by using the scan image lead edge position set with RRC-A.
Effective print data is determined from the image lead edge position data scanned with this set value.
The image lead edge reference position on the document is at 2mm from the right of the document position alignment
plate.
The effective image (effective image data) is determined by scanning the image.
(0~99: Default 20)
When the set value is increased, the image loss becomes greater.
When the set value is changed by 1, the image loss is changed by about 0.1mm.
1/21/1999
Image position
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