U.S. patent application number 10/135519 was filed with the patent office on 2003-11-06 for antenna layout and coordinate positioning method for electromagnetic-induction systems.
Invention is credited to Yeh, Chia-Jui.
Application Number | 20030206142 10/135519 |
Document ID | / |
Family ID | 28791042 |
Filed Date | 2003-11-06 |
United States Patent
Application |
20030206142 |
Kind Code |
A1 |
Yeh, Chia-Jui |
November 6, 2003 |
ANTENNA LAYOUT AND COORDINATE POSITIONING METHOD FOR
ELECTROMAGNETIC-INDUCTION SYSTEMS
Abstract
A 4-4 distribution antenna layout and a five-stage coordinate
positioning method of electromagnetic induction systems being
provided by the present invention is disclosed. The 4-4
distribution antenna layout of the present invention divides
antenna circuitries into x-axis and y-axis groups. The antenna
circuitries within the same group are in equal distance
displacements and in the same direction, which further comprise a
plurality of antenna loops. The formation of each antenna loop
comprises a dense multiple duplicate self-looping method. Moreover,
the five-stage coordinate positioning method of electromagnetic
induction systems comprising, first, carrying out a first procedure
to confirm any signal with voltage amplitude greater than a
standard minimum signal recognition value. Second, carrying out a
second procedure to confirm signal existence of the previous scan
as well as to confirm the nearest antenna loop to the transmission
source. Third, carrying out a third procedure to obtain coordinate
values. And, final, using an internal micro-processing
sub-circuitry of the electromagnetic-induction system to calculate
an absolute coordinate.
Inventors: |
Yeh, Chia-Jui; (Taipei City,
TW) |
Correspondence
Address: |
ROSENBERG, KLEIN & LEE
3458 ELLICOTT CENTER DRIVE-SUITE 101
ELLICOTT CITY
MD
21043
US
|
Family ID: |
28791042 |
Appl. No.: |
10/135519 |
Filed: |
May 1, 2002 |
Current U.S.
Class: |
343/867 ;
343/742 |
Current CPC
Class: |
G06F 3/046 20130101;
H01Q 21/061 20130101; H01Q 7/00 20130101 |
Class at
Publication: |
343/867 ;
343/742 |
International
Class: |
H01Q 021/00 |
Claims
What is claimed is:
1. A coordinate positioning method for electromagnetic-induction
systems, said coordinate positioning method comprising: providing
an antenna layout, said antenna layout comprises a plurality of
antenna loops; carrying out a first scanning procedure for scanning
said plurality of antenna loops, and obtaining a largest voltage
amplitude as well as an antenna position for providing said largest
voltage amplitude from said plurality of antenna loops, said
largest voltage amplitude is greater than a standard minimum signal
recognition value; taking said antenna position as a center of
scanning to proceed a second scanning procedure for scanning said
antenna loops at said antenna position and said antenna position's
neighboring positions, thus obtaining at least three voltage
amplitudes; and taking said at least three voltage amplitudes to
proceed a coordinate calculating procedure for obtaining a
coordinate value.
2. The coordinate positioning method according to claim 1, wherein
said antenna layout further comprises a plurality of antenna groups
in different coordinate axis.
3. The coordinate positioning method according to claim 1, wherein
said antenna layout further comprises a 4-4 distributed antenna
layout.
4. The coordinate positioning method according to claim 3, wherein
said 4-4 distribution antenna layout comprises an x-axis antenna
group and a y-axis antenna group.
5. The coordinate positioning method according to claim 4, wherein
said x-axis antenna group and said y-axis antenna group each
comprises a plurality of antenna circuitries in equal distance
displacements and in the same direction.
6. The coordinate positioning method according to claim 5, wherein
said plurality of antenna circuitries comprises said plurality of
antenna loops.
7. The coordinate positioning method according to claim 6, wherein
the formation of said antenna loops comprises a dense multiple
duplicate self-looping method.
8. The coordinate positioning method according to claim 1, wherein
said first scanning procedure is proceeded by using time-division
method.
9. The coordinate positioning method according to claim 1, wherein
said first scanning procedure further comprises: activating and
deactivating said plurality of antenna loops sequentially and
obtaining a plurality of said voltage amplitudes from said
plurality of antenna loops accordingly; comparing said plurality of
said voltage amplitudes from said plurality of antenna loops to
said standard minimum signal recognition value; and comparing among
said voltage amplitudes which are greater than said standard
minimum signal recognition value, thus obtaining said largest
voltage amplitude as well as said antenna position for providing
said largest voltage amplitude.
10. The coordinate positioning method according to claim 1, wherein
said first scanning procedure further comprises a confirmation
scanning procedure.
11. The coordinate positioning method according to claim 10,
wherein said confirmation scanning procedure comprises: taking said
antenna position as a center of scanning and scanning a half of
said plurality of antenna loops sequentially for obtaining said
plurality of voltage amplitudes of said half of said plurality of
antenna loops; and comparing said plurality of voltage amplitudes
of said half of said plurality of antenna loops to said standard
minimum signal recognition value for obtaining the largest voltage
amplitude of said plurality of voltage amplitudes as well as said
antenna position for providing said largest voltage amplitude.
12. The coordinate positioning method according to claim 1, wherein
said coordinate calculating procedure comprises a logical judgment
procedure for discriminating the source of signal transmission in a
border region of said antenna layout.
13. The coordinate positioning method according to claim 1, wherein
said coordinate calculating procedure comprises a calculation step,
said calculation step is used to calculate the differences between
said largest voltage amplitude and the voltage amplitudes of
neighboring antenna loops.
14. An antenna layout method for electromagnetic-induction systems,
said antenna layout method comprising: providing a plurality of
antenna loops; using said plurality of antenna loops to form a
plurality of antenna circuitries, wherein each of said plurality of
antenna circuitries comprises four antenna loops; using said
plurality of antenna circuitries to form a plurality of antenna
groups in different directions, wherein each of said plurality of
antenna groups in different directions comprises one antenna loop;
and placing said plurality of antenna groups of different
directions into an antenna sub-circuitry of said
electromagnetic-induction system in an equal spacing manner for
forming said antenna layout of said electromagnetic-induction
system.
15. The antenna layout method according to claim 14, wherein the
material of said plurality of antenna loops comprises copper foil
conducting wire.
16. The antenna layout method according to claim 14, wherein said
plurality of antenna loops further comprises a multiple looping
induction antenna.
17. The antenna layout method according to claim 16, wherein said
multiple looping induction antenna is formed by a dense multiple
duplicate self-looping method.
18. The antenna layout method according to claim 16, wherein said
multiple looping induction antenna further comprises a four-looping
type induction antenna.
19. The antenna layout method according to claim 14, wherein each
of said antenna circuitries can receive an
electromagnetic-induction signal from a signal transmission source
through at least three of said antenna loops.
20. The antenna layout method according to claim 14, wherein the
allocation of said plurality of antenna loops of each of said
antenna groups is in equal distance displacements and in the same
direction.
21. The antenna layout method according to claim 20, wherein the
layout method of said antenna groups comprises a two-dimensional
array allocation method.
22. The antenna layout method according to claim 21, wherein the
coordinating method of said two-dimensional array allocation method
further comprises a two-dimensional Cartesian coordinate.
23. A five-stage coordinate positioning method of
electromagnetic-inductio- n systems, said five-stage coordinate
positioning method comprising: carrying out a first universal
scanning procedure for scanning an universal antenna group of
having a first coordinate direction, and obtaining a first largest
voltage amplitude of each antenna signal accordingly; using a
micro-processing sub-circuitry to carry out a first comparative
procedure for comparing said first largest voltage amplitude to a
standard minimum signal recognition value, and confirming a first
antenna position of having said first largest voltage amplitude
greater than said standard minimum signal recognition value; using
said first antenna position as a first scanning basis to proceed a
mid-terrain confirmation scanning procedure for scanning said
antenna group having said first coordinate direction in a half
region, thus obtaining a plurality of second largest voltage
amplitudes within said half region; using said micro-processing
sub-circuitry to carry out a second comparative procedure for
comparing said second largest voltage amplitudes to said standard
minimum signal recognition value, and reconfirming a second antenna
position of having said second largest voltage amplitude greater
than said standard minimum signal recognition value; using said
second antenna position as a second scanning basis to proceed a
first partial confirmation scanning procedure for scanning said
antenna group having said first coordinate direction in a first
partial region, thus obtaining a plurality of third largest voltage
amplitudes within said first partial region; carrying out a second
universal scanning procedure for scanning an universal antenna
group of having a second coordinate direction, and obtaining a
fourth largest voltage amplitude of each antenna signal
accordingly; using said micro-processing sub-circuitry to carry out
a third comparative procedure for comparing among said fourth
largest voltage amplitudes, and obtaining a third antenna position
of having the largest voltage amplitude; using said third antenna
position as a second scanning basis to proceed a second partial
confirmation scanning procedure for scanning said antenna group
having said second coordinate direction in a second partial region,
thus obtaining a plurality of fifth largest voltage amplitudes
within said second partial region; using said second antenna
position and said plurality of third largest voltage amplitudes to
proceed a first coordinate positioning procedure for obtaining a
first coordinate value of said first coordinate direction; and
using said third antenna position and said plurality of fifth
largest voltage amplitudes to proceed a second coordinate
positioning procedure for obtaining a second coordinate value of
said second coordinate direction.
24. The five-stage coordinate positioning method according to claim
23, wherein said first universal scanning procedure is accomplished
by using a time-division basis method to scan said antenna groups
of having said first coordinate direction.
25. The five-stage coordinate positioning method according to claim
24, wherein said time-division basis method is to activate one
antenna loop at a time and keep the remaining antenna loops
deactivated or open-circuited.
26. The five-stage coordinate positioning method according to claim
23, wherein the scanning coverage of said first partial
confirmation scanning procedure includes said second antenna
position and four other closest antenna positions.
27. The five-stage coordinate positioning method according to claim
23, wherein said second universal scanning procedure is
accomplished by using a time-division basis method to scan said
antenna groups of having said second coordinate direction.
28. The five-stage coordinate positioning method according to claim
27, wherein said time-division basis method is to activate one
antenna loop at a time and keep the remaining antenna loops
deactivated or open-circuited.
29. The five-stage coordinate positioning method according to claim
23, wherein the scanning coverage of said second partial
confirmation scanning procedure includes said third antenna
position and four other closest antenna positions.
30. The five-stage coordinate positioning method according to claim
23, wherein said first coordinate positioning procedure further
comprises: using said plurality of third largest voltage amplitudes
to proceed a fourth comparative procedure for obtaining a sixth
largest voltage amplitude and a fourth antenna position
accordingly; using said fourth antenna position and said sixth
largest voltage amplitude to proceed a first logical judgment
procedure for discriminating said fourth antenna position in an
ex-border region of said antenna group in said first coordinate
direction; using said sixth largest voltage amplitude and a seventh
and eighth largest voltage amplitude of neighboring said fourth
antenna position to proceed a first calculation procedure for
obtaining a first coordinate value of said first coordinate
direction; and using said first coordinate value to proceed a
second calculation procedure for obtaining a first absolute
coordinate value of said first coordinate direction.
31. The five-stage coordinate positioning method according to claim
30, wherein said first logical judgment procedure once judged said
fourth antenna position is within the border region of said antenna
group of having said first coordinate direction, then the source of
signal transmission is within the border region of said
electromagnetic-inductio- n system.
32. The five-stage coordinate positioning method according to claim
30, wherein said first calculation procedure further comprises:
using said sixth largest voltage amplitude and said seventh largest
voltage amplitude to proceed a first subtraction for obtaining a
first voltage amplitude difference; using said sixth largest
voltage amplitude and said eighth largest voltage amplitude to
proceed a second subtraction for obtaining a second voltage
amplitude difference; taking the sum of said first voltage
amplitude difference and said second voltage amplitude difference
as a denominator and said first voltage amplitude difference as a
numerator to proceed a first division for obtaining a first voltage
amplitude gradient; and using said first voltage amplitude gradient
and a standard resolution constant to proceed a first
multiplication for obtaining a first relative coordinate value.
33. The five-stage coordinate positioning method according to claim
32, wherein said standard resolution constant is the coordinate
points within every constant distance.
34. The five-stage coordinate positioning method according to claim
30, wherein said first absolute coordinate value is the sum of said
first relative coordinate value and a first fundamental coordinate
value.
35. The five-stage coordinate positioning method according to claim
34, wherein the calculation method of said first fundamental
coordinate value comprises: subtracting one from said fourth
antenna position for obtaining a first difference; and multiplying
said first difference and said standard resolution constant to
obtain said first fundamental coordinate value.
36. The five-stage coordinate positioning method according to claim
23, wherein said second coordinate positioning procedure further
comprises: using said plurality of fifth largest voltage amplitudes
to proceed a fifth comparative procedure for obtaining a ninth
largest voltage amplitude and a fifth antenna position accordingly;
using said fifth antenna position and said ninth largest voltage
amplitude to proceed a second logical judgment procedure for
discriminating said fifth antenna position in an ex-border region
of said antenna group in said second coordinate direction; using
said ninth largest voltage amplitude and a tenth and eleventh
largest voltage amplitude of neighboring said fifth antenna
position to proceed a third calculation procedure for obtaining a
second coordinate value of said second coordinate direction; and
using said second coordinate value to proceed a fourth calculation
procedure for obtaining a second absolute coordinate value of said
second coordinate direction.
37. The five-stage coordinate positioning method according to claim
36, wherein said second logical judgment procedure once judged said
fifth antenna position is within the border region of said antenna
group of having said second coordinate direction, then the source
of signal transmission is within the border region of said
electromagnetic-inductio- n system.
38. The five-stage coordinate positioning method according to claim
36, wherein said third calculation procedure further comprises:
using said ninth largest voltage amplitude and said tenth largest
voltage amplitude to proceed a third subtraction for obtaining a
third voltage amplitude difference; using said ninth largest
voltage amplitude and said eleventh largest voltage amplitude to
proceed a fourth subtraction for obtaining a fourth voltage
amplitude difference; taking the sum of said third voltage
amplitude difference and said fourth voltage amplitude difference
as a denominator and said third voltage amplitude difference as a
numerator to proceed a second division for obtaining a second
voltage amplitude gradient; and using said second voltage amplitude
gradient and a standard resolution constant to proceed a second
multiplication for obtaining said second relative coordinate
value.
39. The five-stage coordinate positioning method according to claim
36, wherein said second absolute coordinate value is the sum of
said second relative coordinate value and a second fundamental
coordinate value.
40. The five-stage coordinate positioning method according to claim
39, wherein the calculation method of said second fundamental
coordinate value comprises: subtracting one from said fifth antenna
position for obtaining a second difference; and multiplying said
second difference and said standard resolution constant to obtain
said second fundamental coordinate value.
41. A five-stage coordinate positioning method of
electromagnetic-inductio- n systems, said five-stage coordinate
positioning method comprising: providing a 4-4 distribution antenna
layout, said 4-4 distribution antenna layout comprising a x-axis
antenna group and a y-axis antenna group; carrying out a x-axis
universal scanning procedure for scanning a plurality of antenna
loops within said x-axis antenna group on a time-division basis,
and obtaining a plurality of first voltage amplitude; using a
micro-processing sub-circuitry to carry out a first comparative
procedure for comparing each of said first voltage amplitude to a
standard minimum signal recognition value, thus obtaining a first
antenna position of having a first largest voltage amplitude
greater than said standard minimum signal recognition value; using
said first antenna position as the center of scanning to proceed a
x-axis mid-terrain confirmation scanning procedure for scanning a
half of said antenna loops within said x-axis antenna group, and
obtaining a plurality of second voltage amplitudes; using said
micro-processing sub-circuitry to carry out a second comparative
procedure for comparing each of said second voltage amplitudes to
said standard minimum signal recognition value, thus obtaining a
second antenna position of having a second largest voltage
amplitude greater than said standard minimum signal recognition
value; using said second antenna position as the center of scanning
to proceed a x-axis partial confirmation scanning procedure for
scanning said second antenna position and four other antennas
neighboring said second antenna position, thus obtaining five third
voltage amplitudes and the relative antenna positions; carrying out
a y-axis universal scanning procedure for scanning another
plurality of antenna loops within said y-axis antenna group on a
time-division basis, and obtaining a plurality of fourth voltage
amplitude; using said micro-processing sub-circuitry to carry out a
third comparative procedure for comparing among said fourth voltage
amplitudes, thus obtaining a third antenna position of having a
fourth largest voltage amplitude using said third antenna position
as the center of scanning to proceed a y-axis partial confirmation
scanning procedure for scanning said third antenna position and
four other antennas neighboring said third antenna position, thus
obtaining five fifth voltage amplitudes and the relative antenna
positions; using said second antenna position and said five third
voltage amplitudes to proceed a fourth comparative procedure for
obtaining first, second and third largest values of said five third
voltage amplitudes, and a fourth antenna position of the largest
value accordingly; using the first, second and third largest values
of said five third voltage amplitudes to proceed a first
calculation procedure for obtaining a x-axis relative coordinate
value; using said fourth antenna position to proceed a second
calculation procedure for obtaining a x-axis fundamental coordinate
value; using said x-axis relative coordinate value and said x-axis
fundamental coordinate value to proceed a third calculation
procedure for obtaining a x-axis absolute coordinate value; using
said second antenna position and said five fifth voltage amplitudes
to proceed a fifth comparative procedure for obtaining first,
second and third largest values of said five fifth voltage
amplitudes, and a fifth antenna position of the largest value of
said five fifth voltage amplitudes accordingly; using the first,
second and third largest values of said five fifth voltage
amplitudes to proceed a fourth calculation procedure for obtaining
a y-axis relative coordinate value; using said fourth antenna
position to proceed a fifth calculation procedure for obtaining a
y-axis fundamental coordinate value; and using said y-axis relative
coordinate value and said y-axis fundamental coordinate value to
proceed a sixth calculation procedure for obtaining a y-axis
absolute coordinate value.
42. The five-stage coordinate positioning method according to claim
41, wherein each of said antenna groups in the same direction
comprises a plurality of antenna circuitries in equal distance
displacements and in the same direction.
43. The five-stage coordinate positioning method according to claim
42, wherein each of said plurality of antenna circuitries in equal
distance displacements and in the same direction comprises four
antenna loops.
44. The five-stage coordinate positioning method according to claim
43, wherein each of said antenna loops can receive an
electromagnetic-inducti- on signal from a signal transmission
source through at least three of said antenna loops.
45. The five-stage coordinate positioning method according to claim
43, wherein each of said antenna loops comprises a four-looping
type induction antenna.
46. The five-stage coordinate positioning method according to claim
41, wherein said first comparative procedure further comprises a
step of repeating said x-axis universal scanning procedure once all
of said plurality of first voltage amplitudes are smaller than said
standard minimum signal recognition value.
47. The five-stage coordinate positioning method according to claim
41, wherein said second comparative procedure further comprises a
step of repeating said x-axis universal scanning procedure once all
of said plurality of second voltage amplitudes are smaller than
said standard minimum signal recognition value.
48. The five-stage coordinate positioning method according to claim
41, wherein said fourth comparative procedure comprises a first
logic step.
49. The five-stage coordinate positioning method according to claim
48, wherein said first logic step is to judge a signal source to be
located in a border region of said x-axis antenna group within said
4-4 distribution antenna layout when the antenna position of the
largest value of said five third voltage amplitudes is the
outermost antenna position.
50. The five-stage coordinate positioning method according to claim
48, wherein said first logic step carries out said first
calculation procedure when the antenna position of the largest
value of said five third voltage amplitudes is not the outermost
antenna position.
51. The five-stage coordinate positioning method according to claim
41, wherein said first calculation procedure comprises a standard
resolution constant, said standard resolution constant is a one
inch expected resolution point divided by the number of antennas
within one inch.
52. The five-stage coordinate positioning method according to claim
41, wherein said second calculation procedure comprises a standard
resolution constant.
53. The five-stage coordinate positioning method according to claim
41, wherein said x-axis absolute coordinate value is the sum of
said x-axis relative coordinate value and said x-axis fundamental
coordinate value.
54. The five-stage coordinate positioning method according to claim
41, wherein said fifth comparative procedure comprises a second
logic step.
55. The five-stage coordinate positioning method according to claim
54, wherein said second logic step is to judge a signal source to
be located in a border region of said y-axis antenna group within
said 4-4 distribution antenna layout when the antenna position of
the largest value of said five fifth voltage amplitudes is the
outermost antenna position.
56. The five-stage coordinate positioning method according to claim
54, wherein said second logic step carries out said fourth
calculation procedure when the antenna position of the largest
value of said five fifth voltage amplitudes is not the outermost
antenna position.
57. The five-stage coordinate positioning method according to claim
41, wherein said fourth calculation procedure comprises a standard
resolution constant.
58. The five-stage coordinate positioning method according to claim
41, wherein said fifth calculation procedure comprises a standard
resolution constant.
59. The five-stage coordinate positioning method according to claim
41, wherein said y-axis absolute coordinate value is the sum of
said y-axis relative coordinate value and said y-axis fundamental
coordinate value.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to an
electromagnetic-induction system, and more particularly, relates an
antenna layout and its coordinate positioning method of the
electromagnetic-induction system.
[0003] 2. Description of the Prior Art
[0004] Because a handwriting recognition system could replace the
mouse, and is more suitable than the mouse to let the user input
words and patterns by user's hands, improvement of the handwriting
recognition system is a hot and important field of current computer
technology. The original intention of the handwriting recognition
system is to replace the mouse. As usual, to enhance the user's
convenience, a handwriting recognition system would usually replace
the mouse by both wireless pen and tablet. Herein, the pen nib of
the wireless pen usually corresponds to the left button of the
mouse. Conventional handwriting recognition systems have been
developed for many years, but these products are applied to perform
only one function, such as drawing or inputting a word.
[0005] In the conventional electromagnetic-induction systems, there
are usually a digitizer tablet and a transducer/cursor in the form
of a pen or a puck. As is well known, there are two operation modes
for determining the position of a pointing device on the surface of
a digitizer tablet, wherein one is a relative mode, and the other
is an absolute mode. A mouse device operates in a relative mode.
The computer sensing the inputs from a mouse recognizes only
relative movements of the mouse in X and Y directions as it is slid
over the surface on which it is resting. If the mouse is lifted and
repositioned on the surface, no change in the signal to the
computer will be detected. A common approach uses a sensing
apparatus inside the mouse to develop a pair of changing signals
corresponding to the longitudinal and transversal movements of the
mouse. On the contrary, a cursor device in a digitizer tablet
system, such as electromagnetic-induction pen, operates in an
absolute mode. If a cursor device is lifted and moved to a new
position on its supporting surface, its signal to a computer will
change to reflect the new absolute position of the cursor device.
Nowadays, various methods have been used to determine the position
of a cursor device on the surface of its supporting tablet, wherein
one common skill which is applied for the absolute mode is
electromagnetic field sensing.
[0006] Early transducer/cursors were connected to the tablet by
means of a multi-conductor cable through which the position and
button/pressure information are transferred virtually without any
problem. The cordless transducer/cursors in some of the prior arts
have attempted to use frequency and/or phase changes to transmit
the non-positional status of the transducer/cursor functions such
as buttons pushed, pen pressure, or the like. However, if there is
no sophisticated processing, frequency and phase changes are very
prone to false reading resulting from several outside factors such
as metal objects, noise, wireless electromagnetic wave and so on.
These problems become more apparent, especially in a larger
digitizer tablet. Improvements have also been made in the prior
arts to allow a user to use pointing devices on a digitizer tablet
system in dual modes of operation that can provide information of
either a relative movement or an absolute position under the
control of the user.
[0007] Usually, a handwriting recognition system is a device with
cordless pressure-sensitivity and electromagnetic-induction. Refer
to FIG. 1, it shows a circuit block diagram of a conventional
cordless pressure-sensitive and electromagnetic-induction device.
Conventional cordless pressure-sensitivity and
electromagnetic-induction device comprises: an
electromagnetic-induction pen and a tablet. There is an oscillating
circuit that consists of LC in the electromagnetic-induction pen.
If the pen point is touched, the amount of inductance will be
changed that results in the variation of oscillating frequency. The
amount of inductance is increased when touching the pen point and
increasing pressure so the variation of oscillating frequency is
also increased. Therefore, the variation of the pressure on the pen
point can be detected by way of the variation of oscillating
frequency. There are two switches on the sidewall of the
electromagnetic-induction pen, the emitted frequency of the
electromagnetic-induction pen can be changed with the capacitance
variation of the LC device that is produced by pushing down or
setting free the switches. Furthermore, the tablet comprises a
detector, an amplifier and an analog-digital converter. In the
conventional tablet, there is a detected loop in the center region
of the tablet, with one-way antennas located on the double faces of
the detected loop, wherein the one-way antennas are equidistantly
arranged in order by way of using array. The main purpose of the
one-way detected loop is only applied to receive the
electromagnetic wave that is emitted by the
electromagnetic-induction pen. When the electromagnetic-induction
pen emits the electromagnetic wave, the one-way antennas receive
the electromagnetic wave, and then the tablet can obtain
correlative information by the electromagnetic induction.
[0008] Therefore, for those conventional antenna layout and signal
detection methods, the obtained coordinate accuracy is normally
low, hence reduces CPU efficiency and the return rate. Thus, an
improvement in coordinate accuracy is still one of the most crucial
goals of development in the industry.
[0009] In accordance with the above description, the present
invention provides an antenna layout and its coordinate positioning
method for electromagnetic induction systems, so as to increase the
coordinate positioning accuracy and strengthen the efficiency of
electromagnetic induction systems.
SUMMARY OF THE INVENTION
[0010] In accordance with the above description of the prior art,
the present invention provides an antenna layout and its coordinate
positioning method of electromagnetic-induction systems for
improving the coordinate accuracy and the efficiency of the
conventional electromagnetic induction systems.
[0011] An object of the present invention is to provide a
coordinate positioning procedure of the electromagnetic-induction
system. The present invention uses a five-stage coordinate
positioning method to increase the coordinate positioning accuracy
and to speed up the coordinate return rate. Thus, the present
invention satisfies the industrial utility.
[0012] Another object of the present invention is to provide a
five-stage coordinate positioning method of the
electromagnetic-induction system. The present invention uses a
coordinate calculation formula to ensure a highly accurate
coordinate calculation. Hence, the present invention can reduce CPU
processing time, as well as can avoid the problem of line defect
when using hand-writing input, thus, can strengthen the
electromagnetic induction system efficiency.
[0013] A further object of the present invention is to provide an
antenna layout of the electromagnetic-induction system. The present
invention uses a 4-4 distribution antenna layout the antenna layout
density. Therefore, the present invention can reduce the area of
printed circuit boards, thus, reducing the production time and
achieving the product size reduction target. Hence, the present
invention satisfies an economical efficiency.
[0014] In accordance with the above description of the objects, the
present invention discloses a 4-4 distribution antenna layout and a
five-stage coordinate positioning method of the
electromagnetic-induction system. The 4-4 distribution antenna
layout of the present invention distributes the electromagnetic
induction system's induction antennas on both sides of the printed
circuit board in a equal space manner and uses two-dimension array
method to form an antenna circuitry for obtaining a clearer signal
when the electromagnetic field changes.
[0015] The antenna circuitries are divided into x-axis and y-axis
groups. The antenna circuitries within the same group are in equal
distance displacements and in the same direction, and further
comprise a plurality of antenna loops. In order to allocate the
antenna circuitries uniformly and to reduce the antenna layout
density, each antenna circuitry within the same direction group
comprises a plurality of antenna loops. For example, an antenna
circuitry consisted of four antenna loops, only three of the
antenna loops surround the transmission source when a signal
transmission source is placed directly above the prime region of
the antenna loops. The formation of each antenna loop comprises a
dense multiple duplicate self-looping method. Therefore, when the
electromagnetic field changes, an antenna with more loops can
induce a stronger induction signal.
[0016] Moreover, the five-stage coordinate positioning method of
electromagnetic induction systems comprising, first, carrying out a
first procedure, the universal scanning procedure, to confirm any
signal with voltage amplitude greater than a standard minimum
signal recognition value. Second, carrying out a second procedure,
the mid-terrain confirmation scanning procedure, to confirm signal
existence of the previous scan as well as to confirm the nearest
antenna loop to the transmission source. Third, carrying out a
third procedure, a partial confirmation scanning procedure, to
obtain coordinate values. And, final, using an internal
micro-processing sub-circuitry of the electromagnetic-induction
system to calculate an absolute coordinate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The foregoing aspects and many of the attendant advantages
of this invention will become more readily appreciated as the same
becomes better understood by reference to the following detailed
description, when taken in conjunction with the accompanying
drawings, wherein:
[0018] FIG. 1 depicts a circuit block diagram of a conventional
electromagnetic induction system;
[0019] FIG. 2A depicts a simplified circuit block diagram of an
electromagnetic induction system of a preferred embodiment of the
present invention;
[0020] FIG. 2B depicts a x-axis antenna layout diagram of the
electromagnetic induction system of the preferred embodiment of the
present invention;
[0021] FIG. 2C depicts a y-axis antenna layout diagram of the
electromagnetic induction system of the preferred embodiment of the
present invention;
[0022] FIG. 2D depicts a structural diagram of an antenna looping
formed by the antenna layout of the electromagnetic induction
system of the preferred embodiment of the present invention;
[0023] FIG. 2E depicts a flowchart of a coordinate positioning
method of the electromagnetic induction system of the preferred
embodiment of the present invention;
[0024] FIG. 2F depicts a mid-terrain confirmation scanning
procedure of the coordinate positioning method of the
electromagnetic induction system of the preferred embodiment of the
present invention;
[0025] FIG. 2G depicts an x-axis coordinate positioning flowchart
of the coordinate positioning method of the electromagnetic
induction system of the preferred embodiment of the present
invention; and
[0026] FIG. 2H depicts a y-axis coordinate positioning flowchart of
the coordinate positioning method of the electromagnetic induction
system of the preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Some sample embodiments of the present invention will now be
described in greater detail. Nevertheless, it should be recognized
that the present invention can be practiced in a wide range of
other embodiments besides those explicitly described, and the scope
of the present invention is expressly not limited except as
specified in the accompanying claims.
[0028] As illustrated in FIG. 2, in a preferred embodiment of the
present invention, first of all, providing an electromagnetic
induction system 200. The electromagnetic induction system 200
comprises an antenna sub-circuitry 205, an internal circuitry 210
and a micro-processing sub-circuitry 215. Wherein, the internal
circuitry 210 comprises a filter sub-circuitry, an amplifier
sub-circuitry, a rectifier sub-circuitry, and a digital-to-analog
converter sub-circuitry. The micro-processing sub-circuitry 215
comprises a plurality of temporary storages 225, and can internally
define and store a voltage reference value. This voltage reference
value is the standard minimum signal recognition value, which is
used to distinguish whether the received signal is a noise or not.
Moreover, the standard minimum signal recognition value is defined
as the largest voltage amplitude of noises received by the
electromagnetic induction system's 200 antennas when there is no
any noticeable transmission source around the electromagnetic
induction system 200. Therefore, the standard minimum signal
recognition value is greater than ordinary noise voltage. Hence,
the micro-processing sub-circuitry 215 within the electromagnetic
induction system 200 only require to do a regular time basis check
on the received voltage values whether or not greater than the
standard minimum signal recognition value. If a received voltage
value is greater than the standard minimum signal recognition value
then one can conclude that there is a signal transmission source
nearby the electromagnetic induction system 200. Normally, the
electromagnetic induction has a characteristic of electromagnetic
signal to be inverse proportional to distance square. That is, in
the view of the receiving end, when the transmission source is far
away from the receiving antenna the signal voltage amplitude will
be smaller than the noise voltage amplitude. And when the
transmission source is close to the receiving antenna the signal
voltage amplitude will be greater than the noise voltage
amplitude.
[0029] Referring now to FIGS. 2B and 2C, in the preferred
embodiment of the present invention, the antenna sub-circuitry 205
of the electromagnetic induction system 200 comprises a 4-4
distribution antenna layout, wherein the antenna layout method of
the 4-4 distribution antenna layout can be a two-dimensional array
allocation method and the two-dimensional Cartesian coordinates can
be applied to the coordinate positions. For example, The 4-4
distribution antenna layout of the present invention uses the
two-dimension array method to distribute a plurality of different
direction antenna groups 220 on both sides of a printed circuit
board in a equal space manner for obtaining a clearer signal when
the electromagnetic field changes. Moreover, a plurality of
antennas of the antenna sub-circuitry 205 further comprises
looping-type inductors and the material of looping-type inductors
comprises copper foil conducting wire. In accordance with the
two-dimensional Cartesian coordinates, the plurality of different
direction antenna groups 220 comprises an x-axis antenna group 220A
and a y-axis antenna group 220B. Wherein, the allocation of antenna
circuitries 230A and 230B of antenna group 220A and 220B is in
equal distance displacements and in the same direction. Moreover,
the x-axis antenna group 220A and the y-axis antenna group 220B
each comprises N/4 x-axis antenna circuitries 230A and M/4 y-axis
antenna circuitries 230B. Furthermore, each x-axis antenna
circuitry and y-axis antenna circuitry includes four antenna loops
235A and 235B respectively for uniformly distributing the antenna
loops on both sides of the printed circuit board. Therefore, the
total number of antenna loops 235A of the N/4 x-axis antenna
circuitries 230A is N, and the total number of antenna loops 235B
of the M/4 y-axis antenna circuitries 230B is M. For equal
direction antenna loops 235A or 235B, only three of the antenna
loops 235A or 235B surround the transmission source when a signal
transmission source is placed directly above the prime region of an
antenna loop 235A or 235B. Apart from that, each antenna loop 235A
and 235B further comprises a multiple looping induction antenna and
the formation of it comprises a dense multiple duplicate
self-looping method. Therefore, when the electromagnetic field
changes, an antenna with more loops can induce a stronger induction
signal, as what is shown in FIG. D.
[0030] Referring now to FIG. 2E, in the preferred embodiment of the
present invention and in accordance with the two-dimensional
Cartesian coordinates, the coordinate positioning method being
carried out by the electromagnetic induction system 200 of the
present invention comprises a five-stage coordinate positioning
method. The five-stage coordinate positioning method includes,
first, carrying out a first universal scanning procedure 240 on the
x-axis antenna group 220A for confirming the positions of the
antenna loops with signal amplitudes greater than the standard
minimum signal recognition value. The first universal scanning
procedure 240 scans N antenna loops 235A within the x-axis antenna
group 220A on a time-division basis method. The time-division basis
method activates one antenna loop at a time and keep the remaining
antenna loops deactivated or open-circuited. When the first antenna
loop is activated, the largest voltage amplitude of the received
signals of the first antenna loop is obtained through the internal
circuitry 210. The largest voltage amplitude of the received
signals is then transferred to the micro-processing sub-circuitry
215 to proceed a first comparative procedure 245 for comparing the
largest voltage amplitude of the received signals of the first
antenna loop to a standard minimum signal recognition value. Each
antenna loop is then activated sequentially with the first
universal scanning procedure 240 and the first comparative
procedure 245 being repeated until N antenna loops 235A within the
x-axis antenna group 220A all being activated once and N signal
voltage amplitudes being obtained. The antenna loop label X.sub.p
of the largest voltage amplitude greater than the standard minimum
signal recognition value is then recorded in a temporary storage
X.sub.top. If there is no antenna loop signal amplitude greater
than the standard minimum signal recognition value then repeat the
first universal scanning procedure 240 and the first comparative
procedure 245 until there is an antenna loop signal amplitude
greater than the standard minimum signal recognition value.
[0031] Referring now to FIGS. 2E and 2F, in the preferred
embodiment of the present invention, carrying out a mid-terrain
confirmation scanning procedure 250 for confirming the existence of
the signal having the largest voltage amplitude from the previous
scan on the x-axis antenna group 220A, as well as finding out the
closest antenna loop to the transmission source. This can avoid the
detection of a sudden noise spike as the largest signal voltage
amplitude. The mid-terrain confirmation scanning procedure 250
comprises: first, the micro-processing sub-circuitry 215 takes out
the antenna loop label X.sub.p from the temporary storage X.sub.top
and defines the antenna loop label X.sub.p as the mid-terrain
scanning basis. Second, taking the antenna loop label X.sub.p as
the center and re-scan a half of the antenna loops including the
antenna loop label X.sub.p within the x-axis antenna group 220A,
that is, N/2 antennas. Third, after obtaining N/2 signal amplitudes
of N/2 antenna loops within the x-axis antenna group 220A,
transferring N/2 signal amplitudes to the micro-processing
sub-circuitry 215 to proceed a second comparative procedure 255 for
comparing the largest voltage amplitude of the N/2 signals to the
standard minimum signal recognition value. If there is another
antenna loop having the signal voltage amplitude greater than the
standard minimum signal recognition value then update the antenna
loop label in the temporary storage X.sub.top. Contrary, If there
is no antenna loop having signal voltage amplitude greater than the
standard minimum signal recognition value then repeat the first
universal scanning procedure 240 and the first comparative
procedure 245 until there is an antenna loop signal amplitude
greater than the standard minimum signal recognition value.
Moreover, if p+(N/4) is greater than N or p-(N/4) is less than 1,
then the coverage of the mid-terrain confirmation scanning
procedure 250 is restricted to the edge of the antenna layout,
scanning N/2 antenna loops including the antenna loop X.sub.p.
[0032] Next, carrying out a first partial confirmation scanning
procedure 260 to scan a partial region of the antenna loop X.sub.p
having the largest signal amplitude within the x-axis antenna group
220A and to obtain an x-axis coordinate value. The antenna loop
label X.sub.p is firstly taken out from the temporary storage
X.sub.top, and from the characteristic of signal being inversely
proportional to distance square, one can conclude the closest
transmission source to the antenna loop X.sub.p, that is, the
transmission source is located directly above the antenna loop
X.sub.p. Another scanning procedure is then carried out, which
covers five antenna loops including the antenna loop X.sub.p, which
is to scan antenna loop X.sub.p-2, X.sub.p-1, X.sub.p, X.sub.p+1,
and X.sub.p+2, and to obtain five signal amplitudes. These signal
amplitudes are then stored into temporary storage X1, X2, X3, X4,
and X5 respectively. After then, carrying out a second universal
scanning procedure 265 on the y-axis antenna group 220B for
confirming the positions of the antenna loops with signal
amplitudes greater than the standard minimum signal recognition
value. The second universal scanning procedure 265 is very similar
to the first universal scanning procedure 240 which scans M antenna
loops 235B within the y-axis antenna group 220B on a time-division
basis method. A third comparative procedure 270 is then carried out
to compare among M signal amplitudes and to obtain the antenna
position of having the largest signal amplitude. The second
universal scanning procedure 265 is differ to the first universal
scanning procedure 240 by not comparing the M signal amplitudes of
M antenna loops 235B to the standard minimum signal recognition
value, but rather compare among themselves. The antenna loop label
Y.sub.p of having the largest voltage amplitude within M signal
amplitudes is then recorded in a temporary storage Y.sub.top.
[0033] Next, carrying out a second partial confirmation scanning
procedure 275 to scan a partial region of the antenna loop Y.sub.p
of having the largest signal amplitude within the y-axis antenna
group 220B and to obtain a y-axis coordinate value. The antenna
loop label Y.sub.p is firstly taken out from the temporary storage
Y.sub.top, and from the characteristic of signal being inversely
proportional to distance square, one can conclude the closest
transmission source to the antenna loop Y.sub.p, that is, the
transmission source is located directly above the antenna loop
Y.sub.p. Another scanning procedure is then carried out, which
covers five antenna loops including the antenna loop Y.sub.p, which
is to scan antenna loop Y.sub.p-2, Y.sub.p-1, Y.sub.p, Y.sub.p+1,
and Y.sub.p+2, and to obtain five signal amplitudes. These signal
amplitudes are then stored into temporary storage Y1, Y2, Y3, Y4,
and Y5 respectively.
[0034] Referring now to FIG. 2F, in the preferred embodiment of the
present invention, once the above procedures are accomplished the
amplitude values (X1, X2, X3, X4, and X5) and (Y1, Y2, Y3, Y4, and
Y5) being obtained are then used to carry out an x-axis coordinate
positioning procedure 280 and a y-axis coordinate positioning
procedure 285 respectively for calculating a set of absolute
coordinates. Therefore, in according to the largest amplitude being
obtained from the first partial confirmation scanning procedure 260
and the second partial confirmation scanning procedure 275, as well
as according to the characteristic of signal being inversely
proportional to distance square, one can conclude that the two
neighboring antenna loops of the largest amplitude antenna loop
should have the second and third largest signal amplitudes.
Accordingly, the x-axis coordinate positioning procedure 280
comprises: first, carrying out a fourth comparative procedure 280A
to compare among the signal amplitudes stored in the temporary
storage X1, X2, X3, X4, and X5 and store the largest amplitude into
a temporary storage X.sub.max and its antenna loop label into
temporary storage X.sub.top. Second, carrying out a first logical
judgment procedure 280B to judge the largest amplitude within the
voltage amplitudes stored in the temporary storage X1, X2, X3, X4,
and X5. If the largest voltage amplitude is stored in temporary
storage X1 or X5, then carry out a second logical judgment
procedure 280C to find out whether or not the antenna loop position
respective to temporary storage X1 or X5 is the first or the
N.sub.th antenna loop of the x-axis antenna group 220A. If it is,
one can conclude that the transmission source is located on the
border region 280D of the x-axis antenna group 220A. If it is not,
needs to return to the mid-terrain confirmation scanning procedure
250. When the largest voltage amplitude is not stored in temporary
storage X1 or X5, then carry out a first data storage procedure
280E for the ease of storing the second and third largest voltage
amplitude into temporary storage X.sub.2nd and X.sub.3rd
respectively. For example, the amplitudes of the neighboring two
antenna loops X.sub.p-1 and X.sub.p+1 of the largest amplitude
antenna loop X.sub.p are stored in temporary storage X.sub.2nd and
X.sub.3rd respectively.
[0035] Next, by means of the micro-processing sub-circuitry 215
carries out a first calculation procedure 280F which includes:
first, subtracting the second largest value X.sub.2nd and the third
largest value X.sub.3rd from the largest value X.sub.max separately
to obtain a first voltage amplitude difference
(X.sub.max-X.sub.2nd) and a second voltage amplitude difference
(X.sub.max-X.sub.3rd). Second, taking the sum of the first voltage
amplitude difference (X.sub.max-X.sub.2nd) and the second voltage
amplitude difference (X.sub.max-X.sub.3rd) as a denominator and the
first voltage amplitude difference (X.sub.max-X.sub.2nd) as a
numerator to obtain a voltage amplitude gradient for the three
neighboring antenna loops X.sub.p-1, X.sub.p, and X.sub.p+1. Third,
multiplying the voltage amplitude gradient to a standard resolution
constant K.sub.r to obtain an x-axis relative coordinate X.sub.r,
wherein the standard resolution constant K.sub.r is defined as the
resolution within a single antenna loop which is a one inch
expected resolution point divided by the number of antennas within
one inch. The standard resolution constant K.sub.r is normally
stored in the micro-processing sub-circuitry 215. Thus, the x-axis
relative coordinate X.sub.r of the present invention is calculated
by the following formula: 1 Xr = ( X max - X 2 nd ) ( X max - X 2
nd ) + ( X max - X 3 r d ) .times. Kr
[0036] Moreover, the x-axis relative coordinate X.sub.r is a
relative coordinate calculated from the partial scanning of the
three neighboring antenna loops X.sub.p-1, X.sub.p, and X.sub.p+1.
Therefore, the x-axis relative coordinate X.sub.r needs to be
transferred to a real x-axis absolute coordinate X.sub.a. A second
calculation procedure 280G is then used to calculate the x-axis
absolute coordinate X.sub.a which sums up the relative coordinate
X.sub.r and a fundamental coordinate value X.sub.base. That is:
Xa=Xr+X.sub.base where X.sub.base=(X.sub.top-1).times.Kr
[0037] In accordance with the above description, an example of
coordinate calculation procedure of the present invention is:
taking (X1,X2,X3,X4,X5) to be (30,60,85,70,45), the respective
antenna label of (X1,X2,X3,X4,X5) are (6,7,8,9,10) and K.sub.r=100;
then X.sub.top=8, X.sub.max=85, X.sub.2nd=70, X.sub.3rd=60;
Therefore 2 Xr = ( 85 - 70 ) ( 85 - 60 ) + ( 85 - 70 ) .times. 100
= 37.5 , x base = ( 8 - 1 ) .times. 100 = 700 , and x a = 700 +
37.5 = 737.5
[0038] Referring now to FIG. 2G, in the preferred embodiment of the
present invention, Accordingly, the y-axis coordinate positioning
procedure 285 comprises: first, carrying out a sixth comparative
procedure 285A to compare among the signal amplitudes stored in the
temporary storage Y1, Y2, Y3, Y4, and Y5 and store the largest
amplitude into a temporary storage Y.sub.max and its antenna loop
label into temporary storage Y.sub.top. Second, carrying out a
third logical judgment procedure 285B to judge the largest
amplitude within the voltage amplitudes stored in the temporary
storage Y1, Y2, Y3, Y4, and Y5. If the largest voltage amplitude is
stored in temporary storage Y1 or Y5, then carry out a fourth
logical judgment procedure 285C to find out whether or not the
antenna loop position respective to temporary storage Y1 or Y5 is
the first or the M.sub.th antenna loop of the y-axis antenna group
220B. If it is, one can conclude that the transmission source is
located on the border region 285D of the y-axis antenna group 220B.
If it is not, needs to return to the second universal scanning
procedure 265. When the largest voltage amplitude is not stored in
temporary storage Y1 or Y5, then carry out a second data storage
procedure 285E for the ease of storing the second and third largest
voltage amplitude into temporary storage Y.sub.2nd and Y.sub.3rd
respectively. For example, the amplitudes of the neighboring two
antenna loops Y.sub.p-1 and Y.sub.p+1 of the largest amplitude
antenna loop Y.sub.p are stored in temporary storage Y.sub.2nd and
Y.sub.3rd respectively.
[0039] Next, by means of the micro-processing sub-circuitry 215
carries out a third calculation procedure 285F which includes:
first, subtracting the second largest value Y.sub.2nd and the third
largest value Y.sub.3rd from the largest value Y.sub.max separately
to obtain a third voltage amplitude difference
(Y.sub.max-Y.sub.2nd) and a fourth voltage amplitude difference
(Y.sub.max-Y.sub.3rd). Second, taking the sum of the third voltage
amplitude difference (Y.sub.max-Y.sub.2nd) and the fourth voltage
amplitude difference (Y.sub.max-Y.sub.3rd) as a denominator and the
third voltage amplitude difference (Y.sub.max-Y.sub.2nd) as a
numerator to obtain a voltage amplitude gradient for the three
neighboring antenna loops Y.sub.p-1, Y.sub.p, and Y.sub.p+1. Third,
multiplying the voltage amplitude gradient to the standard
resolution constant K.sub.r to obtain a y-axis relative coordinate
Y.sub.r. Thus, the y-axis relative coordinate Y.sub.r of the
present invention is calculated by the following formula: 3 Yr = (
Y max - Y 2 nd ) ( Y max - Y 2 nd ) + ( Y max - Y 3 r d ) .times.
Kr
[0040] Finally, a fourth calculation procedure 285G is used to
calculate the y-axis absolute coordinate Y.sub.a which sums up the
relative coordinate Y.sub.r and a fundamental coordinate value
Y.sub.base. That is:
Ya=Yr+Y.sub.base,Y.sub.base=(Y.sub.top-1).times.Kr
[0041] Although a specific embodiment has been illustrated and
described, it will be obvious to those skilled in the art that
various modifications may be made without departing from what is
intended to be limited solely by the appended claims.
[0042] Obviously, many modifications and variations of the present
invention are possible in light of the above teachings. It is
therefore to be understood that within the scope of the appended
claims, the present invention may be practiced otherwise than as
specifically described herein.
* * * * *