Canon 2163B002 service manual Paper path system, Humidity sensor

Chapter 2

Multi sensor

The photoreflector-based multi sensor consists of four LEDs (red, blue, green, infrared) and two light-receiving sensors to detect the leading edges and width of paper and skews in it, and to adjust its registration, head height and calibration.

At head height adjustment, the two light-receiving sensors detect infrared light reflected upon the paper to work out the head height from differences in its meas- urement.

LED(red) LED(green) LED(blue)

Infrared sensor	Infrared LED
	Media

Platen

F-2-31

2.5.4 Paper path system

Feed roller HP sensor Media sensor

Feed roller encoder

F-2-32

Media sensor

The photoreflector-based media sensor detects the presence or absence of paper on the platen.

The sensor detects the presence of paper when it receives sensor light reflected upon the paper.

Feed roller HP sensor

The feed roller HP sensor detects transitions from white (transmitted), or a reference, to black (shielded) when the printer is switched on, thereby setting the home position of feed roller eccentricity correction.

Feed roller encoder

The feed roller encoder is driven to detect the length of paper feeding for each rotation of the feed roller from encoder slits.

2.5.5 Humidity sensor

Humidity sensor

F-2-33

2-24