Detecting The Size Of Copy Paper In The Cassette; Outline; Detecting The Size Of Paper - Canon NP6045 Service Manual

C. Detecting the Size of Copy Paper in the Cassette

1. Outline

The size of the copy paper inside the cassette is detected by the paper size sensor
installed to the rear of the cassette holder.
When the cassette is slid into the cassette holder, the paper size sensor is pushed
by the boss on the cassette, enabling the identification of the width and the length of the
copy paper.
The copier identifies the paper size in relation to the combination of paper width and
length and, at the same time, determines the point at which the scanner is reversed and
how to control blank exposure.
The boss on the cassette used to press the paper size sensor operates in
conjunction with the guide plate inside the cassette, and its position is determined when
the guide plate is adjusted to the paper size.

2. Detecting the Size of Paper

The copy paper length sensor consists of two photointerrupters, and the outputs of
these two photointerrupters are used to identify the length of paper.
The copy paper width sensor, on the other hand, is a variable resistor, and its output
(resistance) is used to determine the width of paper.
Figure 5-206 shows the relationship between paper widths and outputs of the
variable resistors. To ensure that the relationship is maintained, it is important that you
register the paper width basic value whenever you have replaced the DC controller PCB.
(See "Registering Paper Width Basic Value" on p. 10-53.)
COPYRIGHT © 1997 CANON INC.
A4/A3
A4R
STMT-R
STMT-R
(139.7mm)
Paper width
Figure 5-206
CANON NP6045 REV. 1 MAR. 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 5 PICK-UP/FEEDING SYSTEM
A4R A4
(210mm) (297mm)
5-7