Ricoh D009, Service Manual

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Copy Process
D009/D011/D012/D013 6-10 SM
the drum by two laser beams [C], which form an electrostatic latent image on the drum
surface. The amount of charge remaining as a latent image on the drum depends on the
laser beam intensity, controlled by the BICU.
Development
The magnetic developer brush on the development roller [D] contacts the latent image on
the drum. Toner particles are electrostatically attracted to the areas of the drum surface
where the laser reduced the negative charge on the drum.
Image transfer
Paper is fed into the area between the drum surface and the transfer belt [E] at the proper
time to align it with the image on the drum. The transfer bias roller applies a high positive
charge to the reverse side of the paper through the transfer belt. This positive charge pulls
the toner particles from the drum surface onto the paper while the paper is electrostatically
attracted to the transfer belt.
Separation
Paper separates from the drum as a result of the electrical attraction between the paper and
the transfer belt. Pick-off pawls [F] help separate the paper from the drum.
ID sensor
The ID sensor [G] measures the reflectivity of the pattern formed by the laser on the surface
of the drum. This output signal is used for toner supply control and also measures the drum
surface reflectivity, which is used for charge roller voltage control.
Cleaning
The drum cleaning blade [H] removes any toner remaining on the drum surface after the
image is transferred to the paper.
Quenching
The light from the quenching lamp [I] electrically neutralizes the charge on the drum surface.
Cleaning
The 2nd drum cleaning blade [J] removes any remaining toner.