(12) United States Patent
`Chang et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 8,546,705 B2
`Oct. 1, 2013
`
`US008546705B2
`
`(54) DEVICE AND METHOD FOR PREVENTING
`THE INFLUENCE OF CONDUCTING
`MATERAL FROM POINT DETECTION OF
`PROJECTED CAPACTIVE TOUCH PANEL
`
`(75) Inventors: Chin-Fu Chang, Taipei (TW); Yu-Han
`Lin, Taipei (TW); Cheng-Han Lee,
`Taipei (TW)
`(73) Assignee: Egalax Empia Technology Inc., Taipei
`(TW)
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 586 days.
`(21) Appl. No.: 12/407,100
`(22) Filed:
`Mar 19, 2009
`
`(*) Notice:
`
`(65)
`
`(30)
`
`Prior Publication Data
`US 2009/0255737 A1
`Oct. 15, 2009
`Foreign Application Priority Data
`
`(TW) ............................. O971.09691 A
`(TW) ............................. O981OO567 A
`
`Mar. 19, 2008
`Jan. 9, 2009
`(51) Int. Cl.
`G06F 3/44
`G06F 3/04
`G06F 3/045
`G08C 2L/00
`(52) U.S. Cl.
`USPC ......................... 178/18.06:345/173; 34.5/174
`(58) Field of Classification Search
`USPC .............. 345/173–174; 178/1806; 204/416;
`250/208.2: 348/308: 341/26
`See application file for complete search history.
`
`(2006.01)
`(2006.01)
`(2006.01)
`(2006.01)
`
`(56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`2007/0240914 A1* 10, 2007 Lai et al. .................... 178/1806
`2008/0048997 A1* 2/2008 Gillespie et al. .............. 345,174
`2008/0277171 A1* 11/2008 Wright ............
`... 178.18.06
`2008/0309633 A1* 12/2008 Hotelling et al. ............. 345,173
`2009 OOO2336 A1* 1/2009 Choi et al. .........
`... 345,174
`2009.0109.190 A1* 4/2009 Elias ............................. 345,174
`2009/0159344 A1* 6/2009 Hotelling et al. .......... 178/1806
`* cited by examiner
`
`Primary Examiner — Quan-Zhen Wang
`Assistant Examiner — Lin Li
`(74) Attorney, Agent, or Firm — WPAT, PC; Justin King
`
`ABSTRACT
`(57)
`This invention provides a device for preventing the influence
`of conducting material from point detection of projected
`capacitive touch panel. The device includes a first sensing
`layer having a plurality of first axial conductive lines isolated
`from each other and electrically connected to a plurality of
`first outside-connection conducting wires correspondingly, a
`second sensing layer having a plurality of second axial con
`ductive lines isolated from each other and electrically con
`nected to a plurality of second outside-connection conducting
`wires correspondingly, a signal driving line electrically con
`necting to the first and the second outside-connection con
`ducting wires to provide a first sensing signal, and a sensing
`unit electrically connecting the first and the second outside
`connection conducting wires to sense the sensing signal on
`the first and the second axial conductive lines. Wherein, the
`second sensing layer is on a dielectric layer, the first sensing
`layer, and a Substrate in sequence.
`
`24 Claims, 8 Drawing Sheets
`
`
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`U.S. Patent
`
`Oct. 1, 2013
`
`Sheet 1 of 8
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`US 8,546,705 B2
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`100
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`130
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`120
`
`FIG. 1A
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`U.S. Patent
`
`Oct. 1, 2013
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`Sheet 2 of 8
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`US 8,546,705 B2
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`150
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`- 146
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`
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`OZ
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`TP six-8-8-
`Boo &ooooo
`144 P33S3888-83)
`ol{}SS of og () og
`CKKSok K.K.K.K.
`OHCNNSNS-O--d--O--0--OHO
`338c: ...
`FC)-()--()--C-C)-(X-C)--(X-()--C)
`CKKKKKKKKK
`OX-HOX-HOX-HOX-HOX-HOX-HOX-HOX-HOX-HO
`CKKKKKKKKK
`1001-C-C-C-C-T-C-T-C-T-C-K) () {
`... .
`.
`. .N.
`
`...
`
`122 124
`
`FIG. 1B
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`U.S. Patent
`
`Oct. 1, 2013
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`Sheet 3 of 8
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`US 8,546,705 B2
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`U.S. Patent
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`Oct. 1, 2013
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`Sheet 4 of 8
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`US 8,546,705 B2
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`126
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`146
`--
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`126
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`146
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`U.S. Patent
`
`Oct. 1, 2013
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`Sheet 5 of 8
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`US 8,546,705 B2
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`providing a first sensing signal to a plurality of first axial Conductive
`lines and a plurality of second axial conductive lines
`302
`
`sensing a plurality of second and third sensing signals of the first and
`the second axial conductive lines simultaneously
`304
`
`utilizing at least one bigger change of the second and the third
`sensing signals respectively to match a corresponding Coordinate to
`get the position of at least one touch point
`on the corresponding coordinate
`306
`
`FIG. 3A
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`U.S. Patent
`
`Oct. 1, 2013
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`Sheet 6 of 8
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`US 8,546,705 B2
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`providing a first sensing signal to a plurality of first axial conductive
`lines and a plurality of second axial conductive lines
`312
`
`sensing a plurality of second sensing signals of the first axial
`COnductive lines
`314
`
`sensing a plurality of third sensing signals of the second axial
`COnductive lines
`316
`
`utilizing at least one bigger change of the second and the third
`sensing signals respectively to match a corresponding Coordinate to
`get the position of at least one touch point
`on the corresponding coordinate
`318
`
`FIG. 3B
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`U.S. Patent
`
`Oct. 1, 2013
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`Sheet 7 of 8
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`US 8,546,705 B2
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`providing a first sensing signal to a plurality of first axial
`Conductive lines
`322
`
`Sensing a plurality of Second Sensing signals of the first axial
`conductive lines and a plurality of third sensing signals of a
`plurality of Second axial Conductive lines simultaneously
`324
`
`utilizing at least one bigger change of the second and the third
`Sensing signals respectively to match a corresponding Coordinate
`to get the position of at least one touch point on the
`corresponding coordinate
`326
`
`FIG. 3C
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`U.S. Patent
`
`Oct. 1, 2013
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`Sheet 8 of 8
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`US 8,546,705 B2
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`providing a first sensing signal to a
`plurality of first axial conductive lines
`332
`
`sensing a plurality of second
`sensing signals of the first axial
`Conductive lines
`334A
`y
`sensing a plurality of third sensing
`signals of a plurality of Second axial
`COnductive lines
`336A
`
`Sensing a plurality of Second
`sensing signals of a plurality of
`Second axial Conductive lines
`334B
`y
`sensing a plurality of third sensing
`signals of the first axial Conductive
`lines
`336B
`
`—
`
`utilizing at least one bigger change of the second and the third
`Sensing signals respectively to match a corresponding Coordinate to
`get the position of at least one touch point
`on the corresponding coordinate
`338
`
`FIG. 3D
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`

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`US 8,546,705 B2
`
`1.
`DEVICE AND METHOD FOR PREVENTING
`THE INFLUENCE OF CONDUCTING
`MATERAL FROM POINT DETECTION OF
`PROJECTED CAPACTIVE TOUCH PANEL
`
`BACKGROUND OF THE INVENTION
`
`2
`layer (not shown), and a protecting layer (not shown) from
`bottom-up to stack up with the same shape. Herein, these
`elements mentioned above are transparent. The first sensing
`layer 120 has a plurality of first patterned electrodes 122
`serially connected by a plurality of first axial conductive lines
`124 correspondingly, and then electrically connected to a
`plurality of first outside-connection conducting wires 126
`correspondingly. The second sensing layer 140 has a plurality
`of second patterned electrodes 142 serially connected by a
`plurality of second axial conductive lines 144 correspond
`ingly, and then electrically connected to a plurality of second
`outside-connection conducting wires 146 correspondingly. In
`the present diagram, the axial direction of the first axial con
`ductive lines 124 is Y-axial and the axial direction of the
`second axial conductive lines 144 is X-axial, but not limited
`to, the first axial direction could also be X-axial and the
`second axial direction could be Y-axial as well.
`Referring to FIG. 1B, the active circuit 150 of the projected
`capacitive touch panel 100 shown in FIG. 1A is depicted. A
`plurality of first and second outside-connection conducting
`wires 126, 146 electrically connect to a sensing unit 160. The
`relations among the first and the second patterned electrodes
`122, 142, the first and the second axial conductive lines 124,
`144, and the first and the second outside-connection conduct
`ing wires 126, 146 are described in FIG. 1A, and shall not be
`repeated here. When the circuit is active, the sensing unit 160
`sequentially provides a sensing signal to every first axial
`conductive line 124 by each corresponding first outside-con
`nection conducting wire 126, and then sequentially provides
`the sensing signal to every second axial conductive line 144
`by each corresponding second outside-connection conduct
`ing wire 146. In the meanwhile, the first and the second axial
`conductive lines 122, 144 which do not receive the sensing
`signal are electrically connected to ground or a fixed voltage
`level. Since the stray capacitance exists between the first and
`the second axial conductive lines 124, 144, when a user uses
`his/her finger or conducting material to approach or touch a
`touch point TP on the projected capacitive touch panel 100,
`the finger or the conducting material on the touch point TP
`forms an extra capacitance with the first and the second axial
`conductive lines 124,144. This causes the value of the equiva
`lent capacitance to be changed. The sensing unit 160 senses
`the relatively bigger change of corresponding current or
`charges to decide the position of the touch point, Such as (X3.
`Y5). In short, the measuring control circuit sequentially
`drives a sensing signal to each first and second axial conduc
`tive line, and senses the relatively bigger change of corre
`sponding current or charges generated by driving the sensing
`signal to decide the position of the point. Wherein, when any
`axial conductive line is driven by the sensing signal and is
`sensed to get its current change or charge change, other axial
`conductive lines are electrically connected to ground or a
`fixed voltage level to make the effect of stray capacitance
`consistent.
`However, when the projected capacitive touch panel 100
`has a conducting material area OZ on, Such as water or other
`conducting material, the equivalent circuit and the equivalent
`Stray capacitance between the axial conductive lines on the
`conducting material area OZ will be changed. This change
`makes the measuring control circuit, such as sensing unit 160,
`sense the current change or charge change on the axial con
`ductive lines, and then results in misjudgment and mal-op
`eration. Or, when the axial conductiveline related to the touch
`point TP is provided the sensing signal and is sensed change
`in current or charges, the current change or the charge change
`are affected by the conducting material area OZ. That is, those
`relatively bigger changes of the current or charges are
`
`1. Field of the Invention
`This invention generally relates to the field of touch panel,
`and more particularly, to a device and method for preventing
`the influence of conducting material from point detection of
`projected capacitive touch panel.
`2. Description of the Prior Art
`Nowadays, the common touch technologies used by elec
`tronic devices include resistive, Surface capacitive, projected
`capacitive, Surface acoustic wave, optics imaging, infrared,
`bending wave, active digitizer, and so forth. Since the pack
`aging Volumes of the first three technologies are Smaller, their
`precision can be done relatively high. And they are suitable to
`those smaller mobile device or portable consumer electronic
`products.
`In terms of resistive touch technology, the techniques from
`pressing a touch screen to the contact detection, data opera
`tions, and the contact position confirmed have the technical
`limitations from the physical conditions. That is, in order to
`increase the detection area or resolution, it is necessary to
`increase the number of lines. However, the increase in the
`number of lines means that the data is also related increase in
`processing and computing. This causes a heavy load to the
`processor. In addition, touch-pressure mechanism is con
`firmed by the mechanical action completely, a PET film, no
`matter how to improve its pressure-resistance, wear-resis
`tance, anti-deformation and so on, after all, the PET film has
`its limits. So the performance of the transparency is getting
`worse with the use of time and frequency. As for contact
`detection, Some specific areas will be worn by excessively
`use, and thus, the conduction efficiency of an ITO conductive
`film is reduced. Besides, the ITO conductive film must
`reserve borders, and thus the optional of the industrial design
`is restricted. Still, the resistive touch technology is unable to
`achieve approach sense (fingers approach but not touch), as
`well as more difficult to deal with multi-touch.
`Surface capacitive touch technology does not have to use
`the ITO conductive film with high-precision, so the touch side
`has no the similar mechanical structure like the resistive touch
`technology has. Thus, a Surface capacitive touch screen will
`not be worn nor has a similar touch-mechanical fatigue which
`results in the sensitivity drop, and can also perform approach
`sense. However, the Surface capacitive touch technology has
`the problem of hand-shadow effect. That is, when a surface
`capacitive touch screen is active, if user's wrist and fingers
`approach the screen Surface together, it will make the Surface
`of the ITO conductive film and the inside of the screen gen
`erate excessive charges. These excessive charges lead to pro
`duce coupling capacitance and make the Surface capacitive
`touch screen sense error. Also, because the Surface capacitive
`technology senses the contact by the change of the electric
`field, the accuracy of contact detection will be affected when
`the use of environment has the problem of electromagnetic
`interference. Still, after a prolonged use, the contact detection
`also easily offset, so regular or frequent calibration is
`required.
`Referring to FIG. 1A, a three-dimensional decomposition
`diagram of a well-known projected capacitive touch panel
`100 is depicted. The projected capacitive touch panel 100 at
`least includes a substrate 110, a first sensing layer 120, a
`dielectric layer 130, a second sensing layer 140, a bonding
`
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`US 8,546,705 B2
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`3
`bypassed to the adjacent axial conductive line to ground
`through the conducting material area OZ. Therefore, the posi
`tion of the touch point TP cannot be correctly sensed.
`In view of the drawbacks mentioned with the prior art of
`touch point detection, there is a continuous need to develop a
`new and improved device and method for touch point detec
`tion that overcomes the shortages associated with the prior
`art. The advantages of the present invention are that it solves
`the problems mentioned above.
`
`SUMMARY OF THE INVENTION
`
`In accordance with the present invention, a device and
`method for preventing the influence of conducting material
`from point detection of projected capacitive touch panel Sub
`stantially obviates one or more of the problems resulted from
`the limitations and disadvantages of the priorartmentioned in
`the background.
`One of the purposes of the present invention is to provide a
`sensing signal to the axial conductive lines of a touch panel,
`whereby the current and charges among the axial conductive
`lines can be eliminated.
`The present invention provides a device for preventing the
`influence of conducting material from point detection of pro
`jected capacitive touch panel. The device includes a first
`sensing layer having a plurality of first axial conductive lines
`isolated from each other and electrically connected to a plu
`rality of first outside-connection conducting wires corre
`spondingly, a second sensing layer having a plurality of sec
`ond axial conductive lines isolated from each other and
`electrically connected to a plurality of second outside-con
`nection conducting wires correspondingly, a signal driving
`line electrically connecting to the first and the second outside
`connection conducting wires to provide a first sensing signal,
`and a sensing unit electrically connecting the first and the
`second outside-connection conducting wires to sense the
`sensing signal on the first and the second axial conductive
`lines. Wherein, the second sensing layer is on a dielectric
`layer, the first sensing layer, and a Substrate in sequence.
`The present invention provides a method for preventing the
`influence of conducting material from point detection of pro
`jected capacitive touch panel. The method includes (a) pro
`viding a first sensing signal to a plurality of first and second
`axial conductive lines, wherein the first and second axial
`conductive lines are electrically isolated from each other; (b)
`sensing a plurality of second and third sensing signals simul
`taneously, wherein the second and the third sensing signals
`are correspondingly generated by the first and the second
`axial conductive lines receiving the first sensing signal
`respectively; and (c) utilizing at least one bigger change of the
`second and the third sensing signals respectively to match a
`corresponding coordinate to get the position of at least one
`touch point on the corresponding coordinate.
`The present invention provides a method for preventing the
`influence of conducting material from point detection of pro
`jected capacitive touch panel. The method includes (a) pro
`viding a first sensing signal to a plurality of first and second
`axial conductive lines, wherein the first and second axial
`conductive lines are electrically isolated from each other; (b)
`sensing a plurality of second sensing signals; (c) sensing a
`plurality of third sensing signals, wherein the second and the
`third sensing signals are correspondingly generated by the
`first and the second axial conductive lines receiving the first
`sensing signal respectively; and (d) utilizing at least one big
`ger change of the second and the third sensing signals respec
`tively to match a corresponding coordinate to get the position
`of at least one touch point on the corresponding coordinate.
`
`4
`The present invention provides a method for preventing the
`influence of conducting material from point detection of pro
`jected capacitive touch panel. The method includes (a) pro
`viding a first sensing signal to a plurality of first axial con
`ductive lines, wherein the first axial conductive lines are
`electrically isolated from each other; (b) sensing a plurality of
`second sensing signals of the first axial conductive lines and
`a plurality of third sensing signals of a plurality of second
`axial conductive lines, wherein the second axial conductive
`lines are electrically isolated from each other and are isolated
`from the first axial conductive lines, the second and the third
`sensing signals are correspondingly generated by the first and
`the second axial conductive lines receiving the first sensing
`signal and capacitively coupling the second sensing signals
`respectively; and (c) utilizing at least one bigger change of the
`second and the third sensing signals respectively to match a
`corresponding coordinate to get the position of at least one
`touch point on the corresponding coordinate.
`The present invention provides a method for preventing the
`influence of conducting material from point detection of pro
`jected capacitive touch panel. The method includes (a) pro
`viding a first sensing signal to a plurality of first axial con
`ductive lines, wherein the first axial conductive lines are
`electrically isolated from each other; (b) sensing a plurality of
`second sensing signals of the first axial conductive lines; (c)
`sensing a plurality of third sensing signals of a plurality of
`second axial conductive lines, wherein the second axial con
`ductive lines are electrically isolated from each other and are
`isolated from the first axial conductive lines, the second and
`the third sensing signals are correspondingly generated by the
`first and the second axial conductive lines receiving the first
`sensing signal and capacitively coupling the second sensing
`signals respectively; and (d) utilizing at least one bigger
`change of the second and the third sensing signals respec
`tively to match a corresponding coordinate to get the position
`of at least one touch point on the corresponding coordinate.
`The present invention provides a method for preventing the
`influence of conducting material from point detection of pro
`jected capacitive touch panel. The method includes (a) pro
`viding a first sensing signal to a plurality of first axial con
`ductive lines, wherein the first axial conductive lines are
`electrically isolated from each other; (b) sensing a plurality of
`second sensing signals of a plurality of second axial conduc
`tive lines, wherein the second axial conductive lines are elec
`trically isolated from each other and are isolated from the first
`axial conductive lines; (c) sensing a plurality of third sensing
`signals of the first axial conductive lines, wherein the second
`sensing signals are correspondingly generated by the second
`axial conductive lines capacitively coupling the third sensing
`signals, the third sensing signals are correspondingly gener
`ated by the first axial conductive lines receiving the first
`sensing signal; and (d) utilizing at least one bigger change of
`the second and the third sensing signals respectively to match
`a corresponding coordinate to get the position of at least one
`touch point on the corresponding coordinate.
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`60
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`The accompanying drawings incorporated in and forming
`a part of the specification illustrate several aspects of the
`present invention, and together with the description serve to
`explain the principles of the disclosure. In the drawings:
`FIG. 1A illustrates a three-dimensional decomposition dia
`gram of a well-known projected capacitive touch panel;
`FIG.1B illustrates an active circuit of the projected capaci
`tive touch panel shown in FIG. 1A:
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`US 8,546,705 B2
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`5
`FIG. 2A illustrates an active circuit of one preferred
`embodiment in accordance with the present invention;
`FIG. 2B illustrates a part of circuit for another preferred
`embodiment shown in FIG. 2A;
`FIG. 2C illustrates a part of circuit for further another
`preferred embodiment shown in FIG. 2A;
`FIG. 3A illustrates a flow chart of a preferred embodiment
`in accordance with the present invention;
`FIG. 3B illustrates a flow chart of another preferred
`embodiment in accordance with the present invention;
`FIG.3C illustrates a flow chart of further another preferred
`embodiment in accordance with the present invention; and
`FIG. 3D illustrates two flow charts of still other preferred
`embodiments in accordance with the present invention.
`
`DETAILED DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
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`signal CS to control the first sensing signal Vref received by
`its second end 234. Then the first sensing signal Vref is
`transmitted to the first and the second outside-connection
`conducting wires 126, 146. A sensing unit 220 electrically
`connects to the first and the second outside-connection con
`ducting wires 126, 146 through a multiplexer 210 to sense the
`sensing signals on the correspondingly electrical connections
`of the first and the second axial conductive lines 124, 126. In
`this embodiment, the control switch 230 could be an elec
`tronic switch (such as BJT, CMOS or photo-coupler) or could
`be an electromechanical Switch (such as electromagnetic reed
`switch). The sensing unit 220 could be a current detector or a
`charge detector. The number of the multiplexer 210 and the
`sensing unit 220 could be increased or decreased depend on
`the limit of total cost and the speed of touch position sensing.
`This part, however, can be figured out by those skilled in the
`art according to the present embodiment. Thus, no more detail
`will be described.
`Referring to FIG. 2A again, when the control switch 230
`receives the control signal CS to make itself close, the first
`and the second outside-connection conducting wires 126,146
`receive the first sensing signal Vrefby the signal driving line
`232. This makes the entire first and second axial conductive
`lines 124, 144 have the same Voltage level, the first sensing
`signal Vref. In the meantime, there is no voltage difference
`among the first and the second axial conductive lines 124.
`144, so there is no current loop among them as well. If a
`conducting material area OZ exists on the projected capaci
`tive touch panel 100 in the meanwhile, the conducting mate
`rial area OZ will not form current loops with the first and the
`second axial conductive lines 124, 144 because there is no
`voltage difference among the first and the second axial con
`ductive lines 124, 144. Therefore, the conducting material
`area OZ does not change the current among the first and the
`second axial conductive lines 124, 144. In the present inven
`tion, the conducting material area OZ means those conduct
`ing material areas existing on the protecting layer of the touch
`panel (such as water, other conducting material etc.) before a
`user uses his/her finger or other conducting material to touch
`the touch panel.
`When a user uses his/her finger or conducting material to
`approach or touch a touch point TP2 on the projected capaci
`tive touch panel 100, the axial conductive lines 124, 144 and
`the outside-connection conducting wires 126, 146 related to
`the touch point TP2, such as X7, X8 and Y4,Y5, have current
`formed on them, because the touch point TP2 forms a loop to
`ground through the user body. When the sensing unit 220
`senses each outside-connection conducting wire 126,146, the
`current or the charge change on the outside-connection con
`ducting wires 126,146 (X7, X8, Y4,Y5) can be sensed. If the
`current change or the charge change on X8 is bigger than
`those on X7, and the current change or the charge change on
`Y5 is bigger than those onY4, that means the touch point TP2
`near the coordinate position (X8, Y5).
`When a user uses his/her finger or conducting material to
`approach or touch a touch point TP1 on the projected capaci
`tive touch panel 100, the axial conductive lines 124, 144 and
`the outside-connection conducting wires 126, 146 related to
`the touch point TP1 and the conducting material area OZ.
`such as X2, X3 and Y2, Y3, will not be affected by the
`conducting material area OZ. That is, the axial conductive
`lines 124, 144 and the outside-connection conducting wires
`126, 146 have the same voltage level, so when the touchpoint
`TP1 causes bigger current or charge changes on X2, Y3 of the
`outside-connection conducting wires 126, 146, the bigger
`current and charge will not be bypassed to ground through
`X3, Y2 of the outside-connection conducting wires 126, 146.
`
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`35
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`45
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`Some embodiments of the present invention will now be
`described in greater detail. Nevertheless, it should be noted
`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.
`Moreover, some irrelevant details are not drawn in order to
`make the illustrations concise and to provide a clear descrip
`tion for easily understanding the present invention.
`Referring to FIG. 2A, an active circuit 200 of one preferred
`embodiment in accordance with the present invention is
`depicted. A projected capacitive touchpanel 100 (referring to
`FIG. 1A) at least includes a first sensing layer 120 and a
`second sensing layer 140. The first sensing layer 120 has a
`plurality of first axial conductive lines 124 isolated from each
`other and correspondingly electrically connected to a plural
`ity of first outside-connection conducting wires 126. Herein,
`the first sensing layer 120 further has a plurality of first
`patterned transparent electrodes 122 serially connected to the
`first axial conductive lines 124 in cycle. The second sensing
`layer 140 has a plurality of second axial conductive lines 144
`isolated from each other and correspondingly electrically
`40
`connected to a plurality of second outside-connection con
`ducting wires 146. Herein, the second sensing layer 120 fur
`ther has a plurality of second patterned transparent electrodes
`142 serially connected to the second axial conductive lines
`144 in cycle. Wherein, the second sensing layer 140 is on a
`dielectric layer 130, the dielectric layer 130 is on the first
`sensing layer 120, the first sensing layer 120 is on a substrate
`110, and a bonding layer (not shown) and a protecting layer
`(not shown) are on the second sensing layer 140. In this
`embodiment, the first sensing layer 120, the first patterned
`electrodes 122, the first axial conductive lines 124, the second
`sensing layer 140, the second patterned electrodes 142, the
`second axial conductive lines 144, the substrate 110, the
`dielectric layer 130, the bonding layer and the protecting
`layer are transparent material. Besides, the axial direction of
`the first axial conductive lines 124 is Y-axial and the axial
`direction of the second axial conductive lines 144 is X-axial.
`The axial directions of the first and the second axial conduc
`tive lines 124, 144, however, could be X-axial and Y-axial,
`respectively. Or, the axial directions of the two axial conduc
`tive lines 124, 144 are not perpendicular to each other.
`Referring to FIG. 2A again, a signal driving line 232 elec
`trically connects to the first and the second outside-connec
`tion conducting wires 126, 146 and a control switch 230 to
`receive and transmit a first sensing signal Vref. Herein, the
`first end of the control switch 230 electrically connects to the
`signal driving line 232, and its third end 236 receives a control
`
`50
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`55
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`60
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`65
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`DELL EXHIBIT 1028 PAGE 12
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`DELL EXHIBIT 1028 PAGE 12
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`

`7
`Thus, the position of the touch point TP1 still can be sensed
`exactly. What is emphasized here is the coordinate system
`used above being only to explain the relation between the
`axial conductive lines 124, 144 of the present embodiment
`and their corresponding coordinate system. It is not to limit
`the coordinate system of the embodiments in accordance with
`the present invention. Besides, those skilled in the art could
`easily figure out that the position of each touch point can be
`calculated out through at least one axial conductive line near
`the touch point. For example: the interpolation uses the cur
`rent or charge change of the axial conductive line near the
`touch point as weight, referring to the coordinate of the axial
`conductive line near the touch point, and calculates out the
`center of mass.
`Moreover, the above-mentioned embodiments only use
`one conducting material area OZ and one touch point TP1 or
`TP2 as explanations. When there are many conducting mate
`rial areas and touch points existing, the embodiments men
`tioned above are still available. This part can be figured out by
`those skilled in the art according to those embodiments, and
`thus, no more detail will be described.
`Referring to FIG. 3A, a flow chart of a preferred embodi
`ment in accordance with the present invention is depicted.
`Please also refer to FIG. 2A at the same time. In step 302,
`providing a first sensing signal Vrefto a plurality of first axial
`conductive lines 124 concurrently and a plurality of second
`axial conductive lines 144 concurrently. Herein, the plurality
`of first and second axial conductive lines 124, 144 are elec
`trically isolated from each other. In step 304, the sensing unit
`220 simultaneously senses a plurality of second and third
`sensing signals of the plurality of first and second axial con
`ductive lines 124, 144. Herein, the plurality of second and
`third sensing signals are correspondingly generated by the
`plurality of first and second axial conductive lines 124, 144
`receiving the first sensing signal Vref. In step 306, the sensing
`unit 220 respectively uses at least one bigger change of the
`plurality of second and third sensing signals to match a cor
`responding coordinate to get the position of at least one touch
`point on the corresponding coordinate. In the present embodi
`ment, the first axial conductive lines 124 are X-axial, the
`second