HP 1100AHP - Manual (Page 55)

C4224-90962 Printer paper feed system 53
Printer paper feed system
The paper input bin and the single-sheet input slot merge into one, main input area. Paper
placed in either of these areas enables the paper-out sensor (PS001), which informs the
ECU that paper is present. The following steps occur when the printer receives a print job:
Step 1 The ECU enables the laser/scanner assembly and the motor. Paper motion begins
when the ECU energizes the solenoid (SL001).
Step 2 The paper pickup roller rotates once. The paper kick plate pushes the paper against
the pickup roller.
Step 3 The pickup roller grabs the top sheet and advances it to the feed assembly drive
rollers. To ensure that only one sheet is fed, a main separation pad and two subpads
hold the remainder of the stack in place.
Step 4 The feed assembly drive rollers advance the paper to the paper top photosensor
(PS002). This sensor informs the ECU of the exact location of the paper's leading
edge, so that the image being written on the photosensitive drum can be precisely
positioned on the page.
Step 5 The feed assembly drive rollers then advance the paper to the transfer area where
the toner image on the photosensitive drum is transferred to paper.
Step 6 After the image is transferred, the paper enters the fusing assembly where heat
from the fuser and pressure from the pressure roller permanently bond the toner
image to paper. The paper exit sensor (PS201) determines that paper has
successfully moved out of the fusing area.
Step 7 The fusing assembly exit rollers deliver paper to either the paper output bin or the
front paper output slot, depending upon the position of the face-up/face-down lever.
Figure 3-6 Simplified paper path
1 Paper input bin
2 Single sheet input slot