Transfer Block - Canon iR C2880 Series Service Manual

7.1.6 Transfer Block

iR C3380i / iR C3380 / iR C2880i / iR C2880 / iR C3580 / iR C3580i / iR C3080 / iR C3080i
This block consists of 3 steps, in which the toner image is moved from the photosensitive drum surface to paper.
step 4: primary transfer
In this step, toner is moved from the photosensitive drum to the ITB.
A positive bias is applied to the primary transfer roller found on the inner side of the machine, thus charging the ITB to a positive potential. As a result, the negatively
charged toner on the surface of the photosensitive drum moves to the positively charged ITB. This whole process is performed for all colors (Y, M, C, Bk).
step 5: secondary transfer
In this step, the toner on the ITB is moved to paper.
A positive bias is applied to the secondary transfer outside roller to charge the back of paper to a positive potential. As a result, the toner on the ITB moves to the
paper.
To prevent soiling of the back of paper, the secondary transfer outside roller is given a positive and then a negative bias in turns at the end of secondary transfer,
thus returning the residual toner on the secondary transfer outside roller to the ITB.
Thereafter, the residual toner returned to the ITB is collected to the waste toner case in the ITB cleaning block.
step 6: separation
In this step, the rigidity of paper is used to separate paper from the ITB.
Thin paper has little body. The static eliminator decreases the charges on paper, thus weakening the static bonding and, consequently, facilitating separation.
Primary transfer roller
ITB
photosensitive drum
F-7-8
ITB
Secondary transfer inside roller
F-7-9
DC bias
Paper
Secondary transfer outside roller
DC bias
Chapter 7
0013-8467
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