The machine changes the original read point or executes image correction depending on the presence/absence of dust on the stream reading glass or the platen roller

of the ADF to prevent the dust from showing up in the output. These operations are carried out only when the ADF is in use and, in addition, is closed.

[Control timing]

- At the end of a job

- Between sheets (for each reading of a sheet)

- At the start of a job (only when any of the following conditions is true.)

First job after power-on

Dust detected at all points of detection at the end of the previous job

Dust detection failed to end normally at the end of the previous job (e.g., ADF opened)

[Particulars of control]

- At the end of a job (dust detection)

CCD checks the light reflected by the surface of the platen roller of the ADF at the read point to detect the presence/absence of dust. Presence of dust is detected

at points A, B, and C in this order. The point where least dust is detected will be used as the read position for the next job.

The point selected here will be used as the read position for the next job.

Regarding the control at the end of a job, if an original is placed in the ADF with dust detected at all points (A, B, C), the machine will indicate a message on its

control panel to prompt cleaning of the glass surface. The Start key will remain invalid until this message is cleared.

CCD detection position

A B

Main power

Start key

switch

WMUP

STBY

Dust detection

control

F-5-20

Inch type