FO-50A
FO-70A
3. Operational description
CHAPTER 5. CIRCUIT DESCRIPTION
Operational descriptions are given below:
YTransmission operation
[1] Circuit description
When a document is loaded in standby mode, the state of the docu-
ment sensor is sensed via the 1 chip fax engine (FC200). If the sen-
1. General description
sor signal was on, the motor is started to bring the document into the
The compact design of the control PWB is obtained by using CONEXANTstandby position. With depression of the START key in the off-hook
fax engine in the main control section and high density printing of sur-state, transmission takes place.
face mounting parts. Each PWB is independent according to its functionThen, the procedure is sent out from the modem and the motor is
as shown in Fig. 1.rotated to move the document down to the scan line. In the scan
processor, the signal scanned by the CIS is sent to the internal im-
2. PWB configurationage processor and the AD converter to convert the analog signal into
binary data. This binary data is transferred from the scan processor
to the image buffer within the RAM and encoded and stored in the
transmit buffer of the RAM. The data is then converted from parallel
TEL/LIUto serial form by the modem where the serial data is modulated and
PWBsent onto the line.
CIS
YReceive operation
CONTROLThere are two ways of starting reception, manual and automatic.
PWB
LCDDepression of the START key in the off-hook mode in the case of
PWBmanual receive mode, or CI signal detection by the LIU in the auto-
matic receive mode.
POWER
SUPPLYFirst, the FC200 controls the procedure signals from the modem to
PWBbe ready to receive data. When the program goes into phase C, the
PANEL
AC CORDserial data from the modem is converted to parallel form in the mo-
PWB
dem interface of the 1 chip fax engine (FC200) which is stored in the
TX/RXreceive buffer of the RAM. The data in the receive buffer is decoded
MOTOR
software-wise to reproduce it as binary image data in the image buffer.
The data is DMA transferred to the recording processor within the
FC200 which is then converted from parallel to serial form to be sent
Fig. 1
to the thermal head. The data is printed line by line by the FC200
1) Control PWBwhich is assigned to control the motor rotation and strobe signal.
The control PWB controls peripheral PWBs, mechanical parts, trans-YCopy operation
mission, and performs overall control of the unit.To make a copy on this facsimile, the COPY key is pressed when the
This machine employs a 1 chip modem (FM209) which is installed onmachine is in stand-by with a document on the document table and
the control PWB.
the telephone set is in the on-hook state.
First, depression of the COPY key advances the document to the
2) TEL/LIU PWBscan line. Similar to the transmitting operation, the image signal from
This PWB controls connection of the telephone line to the unit.the CIS is converted to a binary signal in the DMA mode via the 1
chip fax engine (FC200) which is then sent to the image buffer of the
RAM. Next, the data is transferred to the recording processor in the
3) Power supply PWB
DMA mode to send the image data to the thermal head which is
This PWB provides voltages of +5V and +24V to the other PWBs.printed line by line. The copying takes place as the operation is re-
peated.
4) Panel PWB
The panel PWB allows input of the operation keys.
5) LCD PWB
This PWB controls the LCD display.
5 � 1 |
ACEC
SHARP
