1. SEMINOR
ON
A PAPERLESS FAX MACHINE
WITH A SINGLE-TOUCH PANEL

2. CONTENTS
• INTRODUCTION
• HARDWARE CONFIGURATION
• OPERATING PROCEDURES
• HANDWRITING RECONSTRUCTION
• CONCLUSIONS
• REFERENCES

3. INTRODUCTION
 Fax machines became popular around the
world in the 1980s.
 In order to reduce paper consumption we
use paperless fax machine.
 In this paperless fax machine single-touch
panel is used as input and output device.

4.  Transmitted and received fax documents are
stored in memory.
 A pressure sensitive stylus is used to write
on the touch panel.
 Handwriting reconstruction algorithm is
used.

5. HARDWARE CONFIGURATION

6.  The modem module for sending and receiving
faxes.
 The touch panel displays the fax documents and
accepts the handwriting signatures.
 The tip of the pressure sensitive stylus is
connected to a pressure sensor through a spring
coil.
 During a signing act, the pressure at the tip is
measured, digitalized by an ADC, and finally sent
to MCU for subsequent processing.

7. OPERATING PROCEDURES
 The touch panel fax machine can operate in one
of the three modes:
1. Fax receiving mode
2. Browsing and handwriting mode
3. Fax transmitting mode

8. HANDWRITING
RECONSTRUCTION
 The handwriting reconstruction algorithm, turn an
user’s signing act into a digital signature as close
to the original as possible.
 During the signing act, the data from the pressure
sensitive stylus and the touch panel are sampled
by using timer interrupts in MCU.

9.  The sampled analog
values are then converted
into digital values by
ADCs and buffered in two
FIFO queues in order as
shown in figure.

10.  Some issues that are considered in data
collection and processing.
1. Resolution of touch panel
2. Signal synchronization
3. Pressure and Strokes
4. Handwriting Reconstruction

11. Resolution of touch panels:
A single-touch panel is composed of two major parts,
an LCD screen for displaying and a thin touch layer
for inputs.
The resolution of an LCD screen is specified explicitly
by enumerating the number of pixels both in width
and height.
The resolution of the touch panel is determined by
the number of bits used in the ADCs adopted.

12. Signal synchronization:
Single-touch panels can response exact one location
that is being touched at a time.
Timer interrupt intervals are made set to be constant.
According to changes in the pressure data measured,
handwriting reconstruction algorithm can generate the
strokes with different thickness.

13. Pressure and Strokes:
 A simple two-step calibration
procedure for the stylus is
performed before writing.
 First, press the pen tip all the way
down and record the pressure
reading as PF .
 Next, let the tip off the touch panel
and record the pressure again as
PE.
 For any pressure P, the pressure
ratio(PR) is calculated as
PR=(P-PE)/(PF-PE)

14. Handwriting reconstruction:
 There are two types of methods to generate
thickness of the stroke
1. line extension
2. circular extension

15. Circular extension is used in handwriting
reconstruction.

17. CONCLUSION
 By using handwriting reconstruction algorithm the
signature can be exactly reproduced.
 Consumption of paper can be reduced.

18. REFERENCES
• http://ieee.ieeexplore.org/
• ITU-T.37: Procedures for the Transfer of Facsimile Data via
Store-and forward on the Internet, 1998.
• ITU-T.38: Procedures for Real-time Group 3 Facsimile
Communication over IP Networks, Amendment 1, 1999.
• Handwriting Recognition Group, <hwr.nici.kun.nl>, May,
2008.

19. QUERIES ?

20. THANK YOU