C. Identifying the Size of Copy Paper1. OutlineThe size of copy paper inside the cassette is identified by the paper size sensorsmounted to the rear of the cassette holder.When the cassette is slid inside the cassette holder, the paper size sensors areactivated by the bosses on the cassette, enabling detection of the width and the lengthof copy paper.The copier identifies the size of paper based on combinations of paper width andlength and, at the same time, determines the point of scanner reversal and the controlmethod for blank exposure.The bosses used to push the paper size sensors operate in conjunction with theguide plate inside the cassette, and the arrangement is determined by adjusting theguide plate to the size of paper to be used.2. Identifying the Size of Copy PaperThe copy paper length sensor uses two photointerrupters, and the length of copypaper is identified based on combinations of the outputs from these twophotointerrupters.On the other hand, the copy paper width sensor uses variable resistors, and thepaper width is identified in reference to the resistance generated by these resistors.Figure 5-207 shows the relationship between paper width and outputs of the variableresistors. You must enter the basic values whenever you have replaced the DC controllerPCB or any of the sensors to ensure that the relationship remains correct.Figure 5-2075-8CHAPTER 5 PICK-UP/FEEDING SYSTEMCOPYRIGHT © 1997 CANON INC. CANON NP6330 REV.0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)STMTRA4RA4/A3Paper widthSTMTR(139.7mm)A4R(210mm)A4(297mm)Variable resistor output
