Sharp FO-2970M Service Manual page 54

FO-2970MU
k. Top margin control
Top margin is set according to the number of lines (the number of HSYNC
interrupt) from detail paper Pin On to LASER input.
The interval between Pin On and point D is 52.6747 mm.
The interval between Point D and point B is: 27.33 (C-D) + 8.3769 (B-C)
= 35.7069 mm
If top margin is 4 mm,
52.6747 - 35.7069 + 4 = 20.9678 m
In case of the actual software processing, chattering of the sensor is
considered to be observed for 9 msec.
The processing speed is 50 mm/sec; while chattering is being observed,
paper is fed by 0.45 mm (9 x 50/1000 = 0.45 mm).
In order to gain top margin of 4 mm, printing data should be processed
after paper is fed by 20.5178 mm (20.9678 – 0.45 = 20.5178 mm) fol-
lowing PIN On detection.
The base machine resolution in the sub-scanning direction is 391.16
dpi; If the value 20.5178 mm is converted into the number of lines, 315.9
lines are obtained from 391.16 x 20.5178/25.4. Accordingly the soft-
ware set value is considered to be based on 316 lines.
Similarly, considering from the fact that resolution of PC printing is 600
dpi, the number of lines is 484.6 lines (600 x 20.5178/25.4=484.6).
The software set value is based on 485 lines.
Pout sensor
Discharge
9.3389mm(A-B)
brush
nip 5.7523mm
A
Paper exit roller
Fusing
Diameter ø24mm
30.3522mm(D-A)
Transfer
roller
ø13.4(13.7)
100.4mm(from Pin On)
123.8410mm(from Pin On until Pout On)
207.875mm(from Pin Off)
Fig. 21
Process speed 50mm/sec
LASER
OPC drum speed 49mm/sec=(50x0.98)
8.3769mm(B-C)
Pin sensor
B
C
Developing
roller
Paper feed
OPC drum
nip 2.7693mm
roller
27.33mm(C-D)
D
37.2mm
(until Pin On)
52.6747mm(from Pin On)
40.0697mm(from Pin Off)
(4) MODEM control block
1) INTRODUCTION
Conexant's FM336 modem is a V.34 half-duplex modem. It supports
Group 3 facsimile transmission/reception at speeds up to 33,600bps in
the V.34 half-duplex mode. In order to optimize the modem configura-
tion for the line conditions, this modem uses V.34 technology. It con-
nects at an optimally selected data rate so that speeds from 2,400bps to
33,600bps can be supported.
This modem can be used on the general public telephone network using
a network control unit (NCU) line termination device. This modem con-
forms to ITU-T V.17, V.21, V.23, V.27ter, V.29, and V.34 specifications. It
also complies with V.8 and T.30 binary signaling conditions. This mo-
dem supports HDLC internally. Therefore, products using built-in error
correction and the T.30 protocol do not need an external serial input/
output (SIO) line on DTE. This modem can execute HDLC framing, as
specified in T.30, at all data rates. Since it can perform zero insertion/
deletion and CRC tasks, this allows enhanced SDLC/HDLC frame op-
eration. The FSK flag pattern detector facilitates FSK detection during
high-speed reception.
This modem features a programmable DTMF transmitter/receiver that
operates in tone mode, and three programmable tone detectors. This
modem is primarily suited to use in small system designs in such envi-
ronments as work plants, offices, and homes because of its low power
consumption and small size. This modem is packaged in a 100-pin PQFP.
2) FEATURES
• Two-wire, half-duplex fax modem that supports transmission/recep
tion speeds up to 33,600bps
- V.17, V.27ter, V.29, V.34, and V.21 2 channel
- Short train option in V.17 and V.27ter
• Two-wire, full-duplex data modem mode
V.21 and V.23 (75bps TX/1,200bps RX or 1,200bps TX/75bps RX)
• PSTN session start
- V.8 signaling
• HDLC supported at all the speeds
- Flag sending, 0 bit insertion, ITU CRC-16 or CRC-32 calculation
and sending
- Flag detection, 0 bit deletion, ITU CRC-16 or CRC-32 checksum
error detection
- FSK flag pattern detection (during high-speed reception)
• Tone mode and function
- Programmable single or dual tone transmission
- DTMF reception
- Tone detection using three programmable tone detectors
• Serial synchronous data
• Parallel synchronous data
• V.34 half-duplex and Automatic Rate Adaptation (ARA)
• TTL- and CMOS-compatible DTE interface
- ITU-T V.24 (EIA/TIA-232-E) (data/control)
- Microprocessor bus (data/configuration/control)
• Reception dynamic range: 0dBm ~ –43dBm (V.17, V.33, V.29, V.27ter,
and V.21)
–9dBm ~ –43dBm (V.34 half-duplex)
• Programmable RLSD turn-on and turn-off thresholds
• Programmable transmission level: 0 ~ –15dBm
• Adjustable speaker output for monitoring communication signals
• DMA support interrupt line
• 16 byte FIFO data buffer (2) for transferring burst data, can be ex
panded up to 255 bytes
• NRZ1 encoding/decoding
• Diagnostic function
• +3.3V operation (+5V input possible)
• +5V analog signal interface
• Standard power consumption:
- Sleep mode: 20mW
- Normal mode: 250mW
• 100-pin PQFP package
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