Samsung ML-2851ND/SEE Service Manual page 25

2.2.2.5 LSU (Laser Scanner Unit)
It is the core part of the LBP which switches from the video data received to the controller to the electro-
static latent image on the OPC drum by controlling laser beam, exposing OPC drum, and turning principle
of polygon mirror. The OPC drum is turned with the paper feeding speed. The /HSYNC signal is created
when the laser beam from LSU reaches the end of the polygon mirror, and the signal is sent to the con-
troller. The controller detects the /HSYNC signal to adjust the vertical line of the image on paper. In other
words, after the /HSYNC signal is detected, the image data is sent to the LSU to adjust the left margin on
paper. The one side of the polygon mirror is one line for scanning.
Service Manual
Product spec and feature
2-15
Samsung Electronics