HP Color LaserJet CM2320 Service Manual - Page 113

Drum cleaning stage, Step 9: drum cleaning, Developing roller engagement/disengagement control

Page 113 highlights

Drum cleaning stage Not all of the toner is removed from the photosensitive drum during the transfer stage. During the cleaning stage, the residual, or waste, toner is cleared from the drum surface to prepare the surface for the next latent-image formation. Step 9: drum cleaning The cleaning blade scrapes the residual toner off the surface of the photosensitive drum and deposits it in the waste-toner container. The drum is now clear, and is ready for the next image-formation process. Figure 5-20 Drum cleaning Cleaning blade Photosensitive drum Waste toner container Sweeper strip Developing roller engagement/disengagement control The developing roller engagement/disengagement control engages the required developing roller with the photosensitive drum according to the print mode-full-color mode or monochrome mode. The necessary developing roller is engaged with the photosensitive drum only when required, preventing a deterioration of the drums and making maximum use of the life. The engagement/disengagement of the developing roller is controlled by the DC controller rotating the main motor and changing the direction of the developing disengagement cam. The DC controller controls the developing roller state, whether engaged or disengaged, by detecting the output signal from the developing home position sensor. All four color developing rollers disengage from the photosensitive drums when the product is turned on and when a print operation is completed. The color developing rollers engage with the photosensitive drums when the full-color mode is designated. Only the black developing roller engages with the photosensitive drum when the monochrome mode is designated. The DC controller determines an abnormality of the developing roller engagement/disengagement function and notifies the formatter when it does not sense the signal from the developing home-position sensor for a specified period during the developing roller engagement/disengagement operation. ENWW Image-formation system 101

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Drum cleaning stage
Not all of the toner is removed from the photosensitive drum during the transfer stage. During the
cleaning stage, the residual, or waste, toner is cleared from the drum surface to prepare the surface for
the next latent-image formation.
Step 9: drum cleaning
The cleaning blade scrapes the residual toner off the surface of the photosensitive drum and deposits
it in the waste-toner container. The drum is now clear, and is ready for the next image-formation process.
Figure 5-20
Drum cleaning
Sweeper strip
Waste toner container
Photosensitive
drum
Cleaning blade
Developing roller engagement/disengagement control
The developing roller engagement/disengagement control engages the required developing roller with
the photosensitive drum according to the print modeā€”full-color mode or monochrome mode.
The necessary developing roller is engaged with the photosensitive drum only when required, preventing
a deterioration of the drums and making maximum use of the life. The engagement/disengagement of
the developing roller is controlled by the DC controller rotating the main motor and changing the direction
of the developing disengagement cam. The DC controller controls the developing roller state, whether
engaged or disengaged, by detecting the output signal from the developing home position sensor.
All four color developing rollers disengage from the photosensitive drums when the product is turned
on and when a print operation is completed. The color developing rollers engage with the photosensitive
drums when the full-color mode is designated. Only the black developing roller engages with the
photosensitive drum when the monochrome mode is designated.
The DC controller determines an abnormality of the developing roller engagement/disengagement
function and notifies the formatter when it does not sense the signal from the developing home-position
sensor for a specified period during the developing roller engagement/disengagement operation.
ENWW
Image-formation system
101