Fig. 440 Squeezing Roller Main Components - Canon NP-70 Service Manual

4-34
NP•70
Two pairs of springs are located beneath the tray to press it upward against the drum. How-
ever, the tray can be lowered by turning the assembly release handle. This handle, when turn-
ed, draws the developing tray downward by means of wires connecting the two. The wires are
connected to the underside of the developing tray.
The scraper blade, located to the Copier-Front end of the tray, cleans off developer from that
portion of the drum surface which comes into contact with the separation belt of the Paper
Separating Subassembly. This "scrape-off ' is performed to prevent the accumulation of toner
on the belt.
3) SQUEEZING ROLLER
The squeezing roller, located at the "after-development" edge of the developing tray, serves
two functions. The primary function is to remove free-floating toner particles from the dis-
persant on the drum surface, as the drum departs the developing tray. Without this "cleaning"
action, contamination of the image background will result as the drum passes in front of the
negative corona.
As a secondary function, this roller physically limits, or "squeezes", the amount of dis-
persant on the drum surface to 0.2 mm. The squeezing action performed here is repeated as
the drum passes in front of the negative corona.
Tray Release Wire
Roller Pivot Housing
Tension Spring
Roller Cleaner
Retainer
Squeezing Roller
Roller Drive
Gear
Spring Tiedown Bracket
Roller Cleaner Sheet
Fig. 4-40 Squeezing roller Main Components
Second Printing,lune, 1974
©CANON INC.