Panasonic DP-150 Service Manual page 34

(2) Semiconductor laser
1)The laser beam is switched ON/OFF with or without the electric current on the two
semiconductor lasers. This "ON/OFF" is based on the digital signals corresponding
to the image data and the beam is emitted onto the drum to form the image.
(Letter "P" image data)
— Semiconductor laser ON
— Semiconductor laser OFF
(3) Collimator lens
1)The emanative beam of the semiconductor laser is converted to the parallel beam
here to stabilize scanning and improve the beam convergence.
Semiconductor laser
(4) Polygon scanner
1)The polygon scanner consists of the hexagon-shaped mirror that converts laser
beam to scanning beam. To perform the high resolution recording, it is important
to pay attention to the scanning speed irregularity from the reflection on each
surface. The tilt difference of each reflection against the axis is checked at startup
performance.
2-16
Collimator lens
Polygon scanner
Hexahedron mirror