- HP All-in-One Printer Manual

76 Theory of operation Q2431-90912
Laser/scanner assembly
The laser/scanner produces the latent electrostatic image on the photosensitive drum in the print
cartridge.The main components of the laser/scanner assembly are the laser driver PCA, the
scanner motor, various mirrors, and the focusing lenses.
Figure 12. Laser/scanner assembly
The laser scanner uses two laser diodes to scan two lines simultaneously producing high speed
laser scanning. After receiving the print command from the host computer, the DC controller
PCA activates the scanner motor which rotates the six-sided scanner mirror. The laser driver
PCA emits light from the two laser diodes according to signals from the DC controller PCA. The
two laser beams strike the six-sided scanning mirror and are directed through the focusing
lenses and down onto the photosensitive drum. The modulated laser beams generate the latent
electrostatic image on the photosensitive drum according to the image data signals received
from the DC controller PCA.
Scanner motor PCA
Scanner motor
Scanner mirror
Focusing lens
BD mirror
Mirror
Photosensitive drum
(inside the print cartridge)
Laser beams
BD PCA