Sharp SF-A55 Service Manual page 14

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C. Detection of document size

Document size is sensed in either of three ways, which correspond to

a different operation.

1) Sensing of document size by the document set tray

Sensing of document sizing in the document set tray is used, in

automatic paper size and automatic magnification selection mode,

in order to recognize the document size when document is set on

the document tray, enabling the automatic selection of paper size

and magnification ratio of copy.

When a document is comprising sheets of different sizes are set,

this sensing method recognizes the largest sheet as the document

size, which is determined by the width measured by the document

width sensors (DWS1 ~ DWS4) and the length measured by the

document length sensors (DLS1, DLS2).

Document size is determined in the timing of document sensing

by the document set sensor (DSD).

DWS1 DWS2 DWS3 DWS4

DLS1

DLS2

– 13 –

Sensor status by document size

F: ON or L output (sensed)

Document size, setting

orientation

DWS1 DWS2 DWS3 DWS4 DLS1

A/B

standard

A4R

B5R

11" x 8.5"

8.5" x 5.5"

Inch

standard

11" x 8.5"R

14" x 8.5

11" x 17"

: OFF or H output

—

DLS2

—

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