Canon imageRUNNER Advance 8585i

To correct uneven image density caused by uneven potential on the surface of the Drum.

NOTE:

This machine performs two dimensional shading which replaces uneven potential of the Photosensitive Drum to the exposure amount to correct. (Default: two dimensional shading is disabled.) As the data of Drum’s uneven potential, the data measured at the shipment of the Drum is used. Therefore, as the life of the Photosensitive Drum advances, it gets deteriorated, so the uneven potential becomes different from the one at the shipment of the Drum. Although the uneven potential of the Drum is changed due to the deterioration, the data can be corrected per horizontal/vertical scanning direction line by outputting a test pattern image with the following procedure.

CAUTION:

This adjustment is executed when the preferred image is not output even if the Primary Charging Wire height adjustment and secure watermark adjustment * are performed. *Secure watermark adjustment: Function Settings>Common>Print Settings>Secure Watermark Settings>Adjust Background/Character Contrast

1. Check that the two dimensional shading is enabled.
   1:When uneven image occurs
   2:When low edge density occurs
   COPIER>OPTION>IMG-LSR>2D-SHADE
   1: Enabled(VD)
   2: Enabled(VL)
2. Read the two dimensional shading ROM data.
   COPIER>FUNCTION>2D-SHADE>2D-READ
3. Read the two dimensional shading ROM data.
   CAUTION:
   Be sure to turn OFF and then ON the main power switch after step 2. Uneven density may be reduced by the two dimensional shading correction at the startup.
4. Output a halftone image with the following conditions and check if uneven density occurs.
   COPIER > TEST > PG > TYPE 6
   COPIER > TEST > PG > PG-PICK A3 (LDR)
   Select the cassette which the following paper is set or larger.
   When uneven density is seen: Go to step 5.
   When uneven density is not seen: Procedure is ended.
5. Output a test pattern for two dimensional shading.
   COPIER > FUNCTION > 2D-SHADE > SHD-P1
   1. Set the cassette.Select the cassette which A3 (LDR) or larger paper is set. Select "SHD-P1" and cassette using "numeric keypad".
   2. Output 3 sheets of the test pattern. Press OK, output 1 sheet of the test pattern.
   CAUTION:
   It is difficult to judge whether uneven potential of the Photosensitive Drum causes uneven density of the output image, so output 3 sheets of the test print and adjust the area where all. (If the same symptom is seen on the same spot of all 3 sheets, it is possibly caused from the Drum.)
   NOTE:
   For the test print, the following 3 types can be output, but basically set SHD-P1 to output. The following shows the use case of each test print.
   • When the image which uneven density occurs is the halftone image with light density COPIER>FUNCTION>2D-SHADE>SHD-P1
   • When the image which uneven density occurs is the halftone image with dark density COPIER>FUNCTION>2D SHADE>SHD-P2
   • When the image which uneven density occurs is the halftone image with dark density COPIER>FUNCTION>2D SHADE>SHD-P3
6. Check (T-shaped) halftone area of the output test print visually and adjust the area of uneven density.
   1. Take a note to write down the values of the following service mode(Lv.2).
   When the adjustment cannot be performed appropriately, these values are required to return to the initial values.
   COPIER>FUNCTION>2D-SHADE>M-LINE1
   COPIER>FUNCTION>2D-SHADE>M-LINE2
   2. Adjust the target horizontal scanning direction (A to O) which uneven density is seen.
   After selecting "M-LINE1/M-LINE2", select the target horizontal scanning window (A to O), and enter the numerical
   value using "numerical keypad".(Lv.2)
   • Horizontal scanning direction A to H
   COPIER>FUNCTION>2D-SHADE>M-LINE1
   • Horizontal scanning direction I to O
   COPIER>FUNCTION>2D-SHADE>M-LINE2
   3. Turn OFF and then ON the main power switch to reflect the setting value.
   CAUTION:
   • Be sure to switch the screen after entering the value. Unless the screen is switched, the numerical value is not reflected. (Actually, the value is not reflected on the screen, but it is retained internally.)
   • When the horizontal scanning direction (H line) is adjusted, the adjustment value of the vertical scanning direction (1 to 27) is also changed.
   • As the value is larger, the density becomes lighter. As the value is smaller, the density becomes darker.
   • Enter the adjustment value in a unit of +/- 30 gradually, output the test pattern and make adjustment while checking the test pattern. If the value is changed dramatically, the image error (while line) may occur.
   • Entering 96 or larger value can generate an error in potential control (E061). In the case of an error, adjust the setting value between 0 and 95.
   4. After the adjustment, output a test print and check the image to complete the procedure.
   CAUTION:
   If the image cannot be adjusted correctly even with this adjustment procedure, reenter the values written in step 6-1.