Konica Minolta bizhub C658 Service Manual page 1796

bizhub C658/C558/C458/C368/C308/C258
[1] IDC sensor/Rr (IDCS/Rr)
(2) Types of color shift
• Color shift is misalignment of the images of three different colors, yellow (Y), magenta (M), and cyan (C), with respect to the image of
black (K).
• Four different types of color shift can occur: color shift in the main scan direction, color shift due to overall scaling error in the main scan
direction, color shift in the sub scan direction, and image skew.
(3) Correction of color shift in the main scan direction
• If the image of each color (Y, M, C) is misaligned with respect to the image of black (K) in the main scan direction, changing the write
start timing in the main scan direction can correct the color shift. Color shift correction needs to be performed separately for the
respective colors (Y, M, C).
• Color shift correction control is activated when the image stabilization sequence is started.
* When the image of magenta is misaligned with respect to the image of black (K) in the sub scan direction
[2]
[1]
[1] Rotational direction of the transfer belt
[3] Before correction
[5] Magenta (M)
[7] After correction
Correction of color shift due to overall scaling error in the main scan direction
• If the image of each color (Y, M, C) and the image of black (K) vary in length in the main scan direction, changing the clock frequency of
the laser diode can correct the length difference in the main scan direction. Color shift correction needs to be performed separately for
the respective colors (Y, M, C).
• Color shift correction control is activated when the image stabilization sequence is started.
O THEORY OF OPERATION bizhub C658/C558/C458/C368/C308/C258 > 3. WRITE
[2]
[2]
[3] [7]
[6]
[8]
[5]
[4]
[2]
[4]
[6]
[8]
O-21
[1]
IDC sensor/Fr (IDCS/Fr)
Transfer belt
Color shift
Black (K)
No color shift
SECTION (PH SECTION)