Operation Panel Control - Minolta Di850 Service Manual

OTHER KINDS OF CONTROL

[4] Operation Panel Control

PRCB
The operation panel consists of OB1 (operation board
1), OB2 (operation board 2), and LCD (indicator
board). On the backlight control board is mounted an
LCD. The LCD has a backlight which is driven by the
OBINVB (OB inverter board) and touch switches which
correspond to the display messages.
The operation panel is controlled by the OB1 based on
the serial data output from the ICB (image control
board).
1. Operation
a. LED ON operation
The LED on the OB2 are turned ON/OFF by shift
register/latch driver. Each IC is turned ON/OFF
according to the serial data from the PRCB.
OB1 TXD
OB1 RXD
OB1 TXD ACK
OB1 RXD ACK
OB1 TXD REQ
OB1 RXD REQ
OB1
ICB
OB2
5VDC
JAM L1
JAM L2
JAM L3
JAM L4
JAMIB
JAM L5
SGND
ADUSDB
b.
(1) LCD display operation
(2) Backlight ON operation
(3) Touch switch control
2-P-6
LCD
OBINVB
WT LED
ST LED
PSMB
SGND
DCPS1
LCD control
The LCD displays various information according
to the 4-bit parallel data from the OB1.
The LCD has a backlight (cold cathode tube) to
facilitate viewing. The backlight is driven by the
OBINVB, and controlled by the OB1 via the OB2.
The LCD has touch switches, enabling you to
directly select items displayed on the screen.
These touch switches are controlled by the OB1.
12VDC
5VDC
SGND