Operation Panel Pba - Toshiba e-STUDIO170F Service Manual

7.5

OPERATION PANEL PBA

This section describes the functions of the Operation panel PBA.
Main PBA
IC7
CPD0-7
Gate
IC22
Main-CPU
IC8
CPA1-3
Gate
The Operation panel PBA consists of the ASIC (I/O port: IC4), LCD (DP1), LED's (LED1-8), key
switches (SW1-56, 58-63), and other peripheral devices. It controls the display of the LCD and the light-
ing of the LED's and detects the pressed status of each key switch. The document sensor and docu-
ment position sensor are also installed on the Operation panel PBA and detect a scanning document.
The Operation panel PBA is connected to CN4 on the Main PBA.
Data communication is carried out between the Operation panel PBA and Main PBA through OPD0-7
and OPA1-3.
Display of the LCD is controlled by the drivers built in the LCD which control the display of each dot
according to the OPD0-7 signals output from the Main PBA, and the E signal, R/WX signal and RS sig-
nal which are output from the ASIC.
Lighting of the LED's is controlled by the ASIC which outputs the lighting signal for each LED (LED1-8)
according to the OD0-7 signals output from the Main PBA. The ASIC causes the HLEB0-7 signals to go
LOW. This allows voltage to be applied to each LED to turn on.
The pressed status of each key switch is detected by judging the levels of the SWS0-7 signals output to
each key switch (SW1-54, 56, 58-63) from the ASIC and the SWC0-7 signals input to the ASIC from
each key switch (SW1-56, 58-63). The ASIC causes the SWS signals to go LOW. At this time, when the
SWC signal input is at "LOW" level, it is judged that the key has been pressed.
For detection of the scanning document, refer to
chapter.
e-STUDIO170F Circuit Description
Operation panel PBA
OPD0-7
1-8 1-8
OPA1-3
13-15 13-15
Fig.7-50
7 - 68
E
74
2-9
78
72
14-16
IC4
ASIC
( I/O port )
49,50,53-55,57-59
26-33
17-24
P.7-38 "7.3.11 Document Detect Circuit" in this
IC2
2 4
DP1
LCD
R/WX
RS
LED1-8
+5V
HLEB0-7
SWS0-7
SW1-56, 58-63
SWC0-7
Key switch
January 2005 © TOSHIBA TEC