Toshiba ESTUDIO170F, Руководство по обслуживанию

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e-STUDIO170F Circuit Description January 2005 © TOSHIBA TEC
7 - 38
7.3.11 Document Detect Circuit
Fig.7-29
The document detect circuit consists of the ASIC (I/O port: IC38) as the central component. It detects
the presence or absence of a document through the document sensor installed on the Operation panel
PBA, and the scanning position through the document position sensor.
When a document is loaded in the machine, the actuator of the document sensor is pushed down by
the document to turn on the sensor. This causes the DDET signal to go LOW and input to the ASIC to
detect the presence of a document.
When the document loaded is transported by the TX motor to the scanning position, the actuator of the
document position sensor is pushed down by the document to turn on the sensor.
This causes the SCNP signal to go LOW and input to the ASIC (I/O port for operation panel: IC4) on the
Operation panel PBA to detect that the transport of the document to the scanning position is completed.
If the SCNP signal does not return to HIGH level even after the scanning of the document has started
and a fixed time has elapsed, the occurrence of a document jam will be assumed.
Signal Name Type Active Description Destination
DDET I L Document detect signal Document
sensor
SCNP I L Document scanning position detect signal Document
position sensor
+5VPS
Document
sensor
Document
position
sensor
Main PBA Operation panel PBA
DDET
18
SCNP
35
25
19-22
1-8
26
1-8
25
19-22
26
IC22
Main-CPU
IC38
ASIC
(I/O port)
IC4
ASIC
(I/O port)
IC7
Gate
OPD0-7 D0-7
CN1 CN4