WO2011038581A1 - 一种电容式触控屏 - Google Patents

一种电容式触控屏 Download PDF

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Publication number
WO2011038581A1
WO2011038581A1 PCT/CN2010/070313 CN2010070313W WO2011038581A1 WO 2011038581 A1 WO2011038581 A1 WO 2011038581A1 CN 2010070313 W CN2010070313 W CN 2010070313W WO 2011038581 A1 WO2011038581 A1 WO 2011038581A1
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WO
WIPO (PCT)
Prior art keywords
touch
electrode
signal
circuit
excitation source
Prior art date
Application number
PCT/CN2010/070313
Other languages
English (en)
French (fr)
Inventor
陈其良
Original Assignee
智点科技有限公司
智点科技（深圳）有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 智点科技有限公司, 智点科技（深圳）有限公司 filed Critical 智点科技有限公司
Priority to EP10819810A priority Critical patent/EP2466430A1/en
Priority to JP2012531215A priority patent/JP2013506211A/ja
Publication of WO2011038581A1 publication Critical patent/WO2011038581A1/zh
Priority to US13/415,853 priority patent/US20120162132A1/en

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Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
    • G06F3/0446—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
    • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
    • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
    • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
    • G06F3/044—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means
    • G06F3/0445—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by capacitive means using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F2203/00—Indexing scheme relating to G06F3/00 - G06F3/048
    • G06F2203/041—Indexing scheme relating to G06F3/041 - G06F3/045
    • G06F2203/04112—Electrode mesh in capacitive digitiser: electrode for touch sensing is formed of a mesh of very fine, normally metallic, interconnected lines that are almost invisible to see. This provides a quite large but transparent electrode surface, without need for ITO or similar transparent conductive material

Definitions

  • the present invention relates to a touch screen, and more particularly to a capacitive touch screen. Background technique
  • Touch is the most important way of human perception, the most natural way for people to interact with machines. Touch screen development has been widely used in many fields such as personal computers, smart phones, public information, smart home appliances, industrial control, and the like. In the current touch field, there are mainly resistive touch screens, photoelectric touch screens, ultrasonic touch screens, and flat capacitive touch screens. In recent years, projected capacitive touch screens have developed rapidly.
  • Resistive touch screen is still the leading product on the market, but the structure of the two-layer substrate of the resistive touch screen makes the reflection of the touch screen greatly affect the brightness of the display when the touch screen and the display panel are stacked together. Display quality such as contrast, color saturation, etc., greatly degrades the overall display quality, and increases the brightness of the backlight of the display panel, which also causes the power consumption to rise; the analog resistive touch screen also has the problem of positioning drift, from time to time. Position calibration; In addition, the working mode of the resistive touch screen electrode makes the life of the touch screen shorter.
  • Infrared touch screens and ultrasonic touch screens do not affect display quality.
  • the infrared touch screen and the ultrasonic touch screen are costly, and water droplets and dust can affect the reliability of the touch screen operation, especially the infrared touch screen and the ultrasonic touch screen mechanism are complicated, and the power consumption is large, so that the infrared Touch screens and ultrasonic touch screens are basically not available on portable products.
  • the structure of the single-layer substrate of the flat capacitive touch screen makes the touch screen have little effect on the display quality when the touch screen and the display panel are stacked together.
  • the planar capacitive touch screen also has the problem of positioning drift. Position calibration is performed from time to time. Water droplets also affect the reliability of the touch screen operation; especially the planar capacitive touch screen consumes a lot of power and costs, and also makes the plane Capacitive touch screens are basically not available on portable products.
  • the projected capacitive touch screen can still be a single-layer substrate structure, and when the touch screen and the display panel are stacked together, the touch screen has little effect on the display quality.
  • the projected capacitive touch screen measures the influence of the finger or other touch object on the coupling capacitance between the electrodes of the touch screen.
  • the finger is detected by measuring the influence of the finger or other touch object on the charging and discharging of the touch screen electrode. Or the location of other touch objects on the touch screen.
  • the anchor point needs to be simulated, not a real digital touch screen.
  • the distributed capacitance in the manufacturing and use environment will affect the reliability of the touch screen operation.
  • the interference of the display drive signal and other electrical signals will affect the operation of the touch screen. Water droplets will also affect the reliability of the touch screen operation.
  • projection The capacitive touch screen has high requirements on the resistance value of the detecting electrode line, so that the detecting electrode line of the projected capacitive touch screen used in combination with the display panel cannot have only a low conductivity transparent electrode layer such as ⁇ .
  • a high-conductivity electrode layer such as metal, which is complicated in manufacturing process and high in cost, especially in the case of large-size, even ultra-large-size touch screens.
  • the current capacitive touch screen whether it is a flat capacitive touch screen or a projected capacitive touch screen, when used in overlap with the display screen, if no shielding layer is provided between the display screen and the touch screen, the display screen
  • the display signal or display state interferes with the touch signal through the coupling capacitance between the display screen and the touch screen, which affects the reliability of the touch screen operation. If a shield is placed between the display and the touch screen, the shield will be reduced.
  • the transmittance of the touch screen affects the display quality, and the cost is increased. If the shielding layer is not provided between the display screen and the touch screen, the calculation and discrimination software is used to eliminate the display interference, which is also consumed. A considerable amount of computing resources makes the detection speed slower and the cost increases.
  • capacitive touch screens Another weakness of capacitive touch screens is that the touch screen can only be operated with a finger as a touch object. When the operator puts on the glove for touch, the response of the capacitive touch screen becomes very sluggish, even not working properly, and the touch screen cannot be operated with a conventional non-metallic stylus.
  • the capacitive touch screen also has the problem of poor waterproof performance. Water droplets on the touch screen and even moisture make the dielectric constant of the capacitive touch screen environment change, which makes the reliability of the capacitive touch screen problem.
  • the present invention is to provide a technical solution, which allows the capacitive touch screen to eliminate the interference of the display on the touch detection, and allows the operator to bring the gloves to work smoothly; the interference of the display on the touch detection can be eliminated. It can work normally in wet or dripping environments; achieve high resolution of capacitive touch screens.
  • the basic technical idea of the present invention is to: establish a return electrode of a touch signal on a capacitive touch screen or an application product having a capacitive touch screen, and use a touch detection electrode and a touch reflow for detecting a change of the touch signal.
  • the electrodes are respectively connected to different output ends of the touch excitation source, and form a closed touch loop between the touch excitation source, the touch detection electrode, the touch return electrode, and the coupling capacitance between the touch detection electrode and the touch return electrode.
  • the touch signal flowing from the touch excitation source into the touch detection electrode flows back to the touch excitation source from the touch return electrode; and the touch system is isolated from other systems to prevent crosstalk between signals between different systems.
  • the control signal flows in the closed system; the touch information is acquired by detecting changes in the touch signal current of a specific frequency or other specific features, thereby preventing interference of other signals or other environmental substances on the touch detection.
  • the basic working principle of the capacitive touch screen of the present invention is: two sets of intersecting touch electrode groups are respectively arranged on different layers of the touch panel separated by an insulating layer, and the touch circuit has a touch excitation source and touch signal detection
  • the two adjacent touch electrodes on the touch screen are respectively connected to two different output terminals of the touch excitation source, one as a touch detection electrode and one as a touch return electrode.
  • the touch signal flowing out from one output end of the touch excitation source flows into the touch electrode line connected thereto through the touch signal sampling component, and flows into the touch sensor through the coupling capacitance between the different touch electrode lines.
  • the finger or other touch object changes the coupling capacitance between the different touch electrode lines, and the coupling capacitance changes.
  • the current of the touch signal on the touch loop is also changed accordingly.
  • the touch circuit sequentially connects two adjacent touch electrode lines of the touch screen to two different output ends of the touch excitation source in a scanning manner, and at the same time, the touch signal detection circuit detects the change of the touch signal current on the output end. Find the touch electrode line with the largest change in the touch signal current or the current change exceeding a certain threshold, so as to find the position of the finger or other touch object on the touch panel.
  • the non-metal touch object Since the touch signal flows on a closed loop formed between the touch circuit and the different touch electrode lines on the touch panel, the non-metal touch object having a different dielectric constant and air dielectric coefficient approaches or touches the touch screen.
  • the coupling capacitance between different touch electrode lines can also be changed, resulting in a change in the touch signal current on the touch loop.
  • a common non-metallic stylus can also be used to operate a capacitive touch screen; when a metal touch object approaches or touches the touch screen, the metal touch object changes the effective coupling distance of the coupling capacitor electrodes between different touch electrodes. Thereby changing the coupling capacitance between the touch electrode lines, causing a change in the touch signal current on the loop, so that the metal touch object can also be used to operate the capacitive touch screen.
  • the touch object Since the touch signal flows on the closed loop formed between the touch circuit and the different touch electrode lines on the touch panel, the touch object changes the coupling capacitance between the different touch electrode lines, thereby causing touch on the touch loop.
  • the change of the signal current that is, as long as the characteristics and parameters of the device in the loop are changed, the change of the touch signal current on the touch loop can be caused, and the leakage current is not required to be drawn from the touch electrode line of the touch screen. Let the touch signal detection circuit obtain touch information.
  • the touch system touchpad and touch circuit;
  • the display system including the display screen, the backlight and its driving circuit
  • the host circuit can be isolated, in particular, the touch circuit power and touch
  • the display circuit power supply used for the screen overlap is isolated from the host power supply; the so-called isolation is to provide an isolator between the touch circuit and the host computer and the display circuit, so that the touch signal cannot smoothly flow between the two circuits.
  • the touch screen is overlapped with the display screen, the touch signal cannot flow from the touch screen and the touch circuit to the display circuit or the host circuit and then flows back to the touch circuit, thereby avoiding the touch screen, the touch circuit and the display.
  • the coupling between the circuits and the host circuitry interferes with touch detection.
  • the touch signal loop on the touch screen causes the change of the touch signal current on the touch loop to be affected only when the touch object touches the touch detection electrode and the touch return electrode at the same time, thereby reducing the touch signal touch.
  • the crosstalk flow between the touch electrodes of the control panel; and the touch excitation signal can be applied to the plurality of electrode lines at the same time, further reducing the crosstalk flow of the touch signal, improving the accuracy of the judgment of the touched electrodes, and realizing the space digitization Capacitive touch screen.
  • the touch electrode line is made fine enough, and the touch loop on the touch screen is very small in space, realizing a high-precision capacitive touch screen. By detecting the relative value of the amount of change of the touch signal on each electrode line to determine the touched electrode line, the resistance value of the electrode line can be reduced, and a large-sized or even large-sized capacitive touch screen can be realized.
  • the touch circuit is misjudged as the operator's touch.
  • an electrode is arranged on the outer casing of the hand-held application product, and the electrode on the outer casing is selected as a touch reflow electrode, and the operator holds the palm of the application product to contact the outer casing of the product, and the finger approaches or touches the touch screen.
  • a coupling capacitor is formed between the finger and the touch electrode line, and the touch excitation signal on the electrode line flows into the finger through the coupling capacitor portion, and flows into the touch return electrode on the outer casing of the application product by the palm of the application product. Then, the touch return electrode flows back to the touch excitation source to form a flow of the touch signal on the closed loop.
  • the water droplet on the surface of the touch screen does not cause the connection between the touch electrode and the touch reflow electrode on the outer casing of the application product, and the closed loop of the touch excitation source, the touch detection electrode and the touch return electrode cannot be formed. It does not affect the judgment of the touch circuit on the touch signal.
  • a capacitive touch screen includes a touch substrate and a touch circuit.
  • the touch circuit has a touch excitation source and a touch signal detection circuit.
  • the touch substrate is provided with a touch electrode group. When there are less than two sets of touch electrodes, each group of touch electrodes is disposed on different touch substrates or is separated on the same touch substrate by an insulating layer; the touch substrate is disposed on the application product, and the application product has a display system.
  • a first output end of the touch excitation source is used for at least part of the detection period Applying a touch signal to the connected electrode lines at a time;
  • the touch signal detecting circuit is configured to select at least part of the electrode lines as the touch detection electrodes during at least part of the detection period to detect whether the partial electrode lines are touched;
  • the touch detection electrode refers to an electrode that detects a change of a touch signal flowing through the electrode while applying a touch signal to the electrode; and the touch control circuit selects a touch substrate while selecting a part of the electrode as a detection electrode
  • the part of the electrode line is a touch reflow electrode;
  • the touch reflow electrode is a second connected to the touch excitation source when a touch signal is applied to the touch detection electrode and the change of the touch signal is detected.
  • the output terminal is connected to another touch excitation source, and provides a touch electrode for providing a return path for the touch signal on the detection electrode.
  • a capacitive touch screen comprising a touch substrate and a touch circuit, the touch circuit has a touch excitation source and a touch signal detection circuit, and the touch substrate is provided with a touch electrode group;
  • each set of touch electrodes is disposed on different touch substrates or is separated on the same touch substrate by an insulating layer; the touch substrate is disposed on the application product.
  • the application product has a display system (including a display screen and a driving circuit thereof, a backlight and a driving circuit thereof); the first output end of the touch excitation source is used to apply touch to the connected electrode lines at least part of the detection period
  • the touch signal detecting circuit is configured to select at least part of the electrode lines as the touch detecting electrodes to detect whether the partial electrode lines are touched during at least part of the detecting period; the touch detecting electrodes refer to While the electrode is applied with the touch signal, the electrode that changes through the touch signal of the electrode is also detected; the electrode is disposed on the outer casing of the application product; the touch circuit selection application is applied
  • the electrode on the outer casing of the product is a touch reflow electrode; the touch reflow electrode is connected to the touch excitation source when a touch signal is applied to the touch detection electrode and the change of the touch signal is detected.
  • the second output end is connected to another touch excitation source, and provides a touch electrode for providing a return path for the touch signal on the detecting electrode.
  • the touch reflow electrode is part or all of an electrode line that does not intersect the touch detection electrode, or part or all of the electrode line that intersects the touch detection electrode, or It is part or all of the electrode lines that intersect and do not intersect with the touch detection electrodes.
  • the touch reflow electrode that does not intersect the touch detection electrode is an electrode line on one side or both sides adjacent to the touch detection electrode.
  • the touch substrate is a flexible or rigid transparent substrate. According to another specific aspect of the present invention, the touch substrate and the flat panel display are combined with a substrate.
  • the touch electrode is a display electrode.
  • an electrode line connected to the touch circuit on the touch substrate is disposed on a touch surface or a non-touch surface of the touch substrate.
  • the touch substrate has an electrode not connected to the touch circuit, in addition to the electrode line connected to the touch circuit.
  • the touch circuit simultaneously performs touch detection on a plurality of touch detection electrodes on the touch substrate.
  • the plurality of touch detection electrodes on the touch substrate are connected in parallel for detection.
  • the plurality of touch detection electrodes on the touch substrate are independently detected.
  • the output of the touch excitation source connected by the plurality of independently detected touch detection electrodes is different.
  • the touch detection signals are different from the touch signals on the different output terminals of the same touch excitation source and the different touch excitation sources.
  • the difference in the touch signal refers to at least one of a magnitude, a phase, and a frequency of the touch signal.
  • At least one output end of the same touch excitation source or different touch excitation source output ends connected to different electrode lines is connected to the ground end of the touch circuit.
  • a signal isolation device is disposed between the touch excitation source and the host circuit power supply and the display system power supply of the application product; the signal isolation device is a high resistance device of the touch signal.
  • the touch electrodes on the touch substrate are a set of non-intersecting electrode lines
  • the touch circuit determines the touched electrodes by comparing the magnitudes of the touch signals on different electrode lines. The position of the touched point on the touched electrode is located by the magnitude of the change in the touch signal on the touched electrode.
  • the touch electrodes on the touch substrate are a set of non-intersecting electrode lines, and the different electrode lines have lead ends in different directions, and the electrode lines in different directions are taken as detection electrodes;
  • the control circuit determines the touched electrode by comparing the magnitudes of the touch signals on different touch electrodes, and compares the size of the touch signal on the detecting electrodes of the different directions to locate the position of the touched point on the touched electrode.
  • the non-intersecting electrode lines are fold lines.
  • the technical solution of the present invention establishes a reflow electrode of a touch signal on a touch screen or an application product with a touch screen, forms a closed loop of the touch signal between the touch circuit and the touch electrode, and then touches
  • the system is isolated from other systems, reducing crosstalk between signals from different systems, and preventing other signals, especially display signals, from affecting touch detection.
  • a closed loop of the touch signal is formed between the touch circuit and the touch electrode on the touch screen, and the touch object changes the coupling capacitance between the different electrode lines, so that the operator can bring the glove smoothly. Work, let the non-metallic pen and metal pen can operate the touch screen.
  • the touch signal loop on the touch screen also reduces the crosstalk flow between the touch signals on the touch electrodes of the touch screen, improves the accuracy of the touched electrodes, and realizes the space digitalized capacitive touch screen. .
  • the technical solution of the present invention provides a touch reflow electrode on the outer casing of the application product, and establishes a closed loop of the touch signal between the touch circuit, the touch electrode on the touch screen and the touch reflow electrode of the outer casing, thereby avoiding The effect of water droplets on the touch circuit to determine the touch signal.
  • FIG. 1 is a schematic diagram of electrical connections according to a first embodiment and a second embodiment of the present invention
  • FIG. 2 is a schematic diagram of electrical connections according to a third embodiment of the present invention.
  • FIG. 3 is a schematic diagram of electrical connections according to a fourth embodiment of the present invention.
  • 4 is a schematic diagram of electrical connections according to a fifth embodiment of the present invention.
  • Figure 5 is a schematic view showing the electrical connection of a sixth embodiment of the present invention.
  • FIG. 6 is a schematic diagram of electrical connections according to a seventh embodiment of the present invention.
  • Figure 7 is a schematic view showing the electrical connection of the eighth embodiment of the present invention.
  • Fig. 8 is a schematic view showing the electrical connection of a ninth embodiment of the present invention. detailed description
  • the capacitive touch screen 100 shown in FIG. la includes a touch panel 110 and a touch circuit 140.
  • the touch panel 110 is provided with two sets of mutually orthogonal row electrode groups 120 spaced apart by an insulating layer (the row electrode lines 121, 122, ..., 12i-2 12i-l 12i, 12i+l, 12i+) 2 ..., 12m) and column electrode group 130 (the column electrode lines 131, 132, ..., 13j-2, 13j-1, 13j, 13j+1, 13j+2, ..., 13n).
  • the touch circuit 140 has a touch excitation source 150 and a touch signal detection circuit 160.
  • the touch signal frequency of the touch excitation source 150 is selected to be ⁇ or above.
  • the touch signal detecting circuit 160 is composed of a signal detecting channel 161, a data sampling channel 162, a data processing and timing controller 163; the signal detecting channel 161 has a touch signal sampling component 1611, a buffer 1612, a differential amplifying circuit 1613, and the like;
  • the sampling channel 162 has an analog-to-digital conversion circuit;
  • the data processing and timing control circuit 163 is a central processing unit (CPU MCU) having a data computing capability and a data output input interface, and the central processing unit has control software and data processing software.
  • the touch signal detecting circuit 160 of the touch circuit 140 selects the electrode line 12i of the row electrode group 120 as a detecting electrode, and allows the electrode line 12i to communicate with the output end 151 of the touch excitation source 150 through the touch signal sampling component 1611.
  • the other circuits of the signal detecting circuit 160 are connected to the two ends of the touch signal sampling component 1611; the electrode wires 12i-1 and 12i+1 in the row electrode group 120 are connected to the output end 152 of the touch excitation source 150 as a touch.
  • the touch signal flowing out from the touch excitation source output end 151 flows into the row electrode line 12i via the touch signal sampling component 1611, and flows into the electrode line 12i-1 via the coupling capacitance d_r between the electrode line 12i and the electrode line 12i-1.
  • the coupling capacitor C 1+ r between the electrode line 12i and the electrode line 12i+1 flows into the electrode line 12i+1, and then flows back from the electrode lines 12i-1 and 12i+1 to the touch excitation source output terminal 152, and the touch signal is The flow on the closed touch loop, the equivalent circuit is shown in Figure lb.
  • the touch circuit 140 sequentially connects the electrode lines of the touch screen 100 to the output end 151 of the touch excitation source 150 through the touch signal sampling component 1611 in a scanning manner, and simultaneously connects the touch electrode lines adjacent to each other at the same time.
  • the output end 152 of the excitation source 150 is controlled so that all the remaining electrode lines are also connected to the output end 151 of the touch excitation source 150, and the touch signal detecting circuit 160 detects the change of the touch signal current flowing through the touch signal sampling element 1611. And finding that the touch electrode line whose touch current current changes the most and exceeds a certain threshold is the touched electrode line; and the intersection position of the touched electrode line in the row electrode group 120 and the touched electrode line in the column electrode group 130 For the touch position of the finger.
  • the condition of the touched electrode line is determined, and only the electrode line whose detected touch signal change exceeds a certain threshold is detected as the touched electrode line, so that the capacitive touch screen loo allows simultaneous multi-touch.
  • the touch object 170 Since the touch signal flows on the closed loop formed between the touch control circuit 140 and the different touch electrode lines on the touch panel 110, the touch object 170 is close to a non-metallic object having a different dielectric constant and air dielectric constant. Or touching the touch screen 100, it is also possible to change the coupling capacitance between the adjacent touch electrode lines, causing a change in the touch signal current on the touch loop, so that a non-metallic touch object (such as a normal stylus) It can also be used to operate the capacitive touch screen 100; when the touch object 170 approaches or touches the touch screen 100 with a metal object, the metal object changes the effective coupling distance between adjacent touch electrode lines, thereby changing the touch. The coupling capacitances Cw and C 1+1 between the electrode lines cause a change in the touch signal current on the loop, so that a metal touch object (such as a metal stylus) can also be used to operate the capacitive touch screen 100.
  • the row electrode line 12i in the row electrode group 120 can be communicated with the output end 151 of the touch excitation source 150 through the touch signal sampling component 1611 during the detection period, and other circuits of the touch signal detecting circuit 160 are connected to the touch signal. Both ends of the sampling element 1611; all the remaining row electrode lines (including the row electrode lines 12i-1 and 12i+1) in the row electrode group 120 are connected to the output end 152 of the touch excitation source 150 as a touch signal. The return electrode; all the column electrode lines of the column electrode group 130 are directly connected to the output end 151 of the touch excitation source 150.
  • the touch object 170 approaches or contacts the row electrode line 12i, the coupling capacitance and the change of C 1+1 are also changed, and the touched electrode can be found by detecting the change of the touch signal current flowing through the touch signal sampling component 1611. line.
  • the row electrode line 12i in the row electrode group 120 can be communicated with the output end 151 of the touch excitation source 150 through the touch signal sampling component 1611 during the detection period, and other circuits of the touch signal detecting circuit 160 are connected to the touch signal. Both ends of the sampling element 1611; all remaining row electrode lines (including the row electrode lines 12i-1 and 12i+1) in the row electrode group 120 are connected to the output end 152 of the touch excitation source 150; the column electrode group 130 is disposed. All of the column electrode lines are also in communication with the output 152 of the touch excitation source 150.
  • the touch object 170 approaches or contacts the row electrode line 12i, the coupling capacitance and the change of C 1+1 are also changed, and the touched electrode can be found by detecting the change of the touch signal current flowing through the touch signal sampling component 1611. line.
  • the row electrode line 12i is connected to the output end 151 of the touch excitation source 150 through the touch signal sampling component 1611, and other circuits of the touch signal detecting circuit 160 are connected to both ends of the touch signal sampling component 1611; All the remaining row electrode lines in the row electrode group 120 are also connected to the output end 151 of the touch excitation source 150, and all the column electrode lines of the column electrode group 130 are connected to the output end 152 of the touch excitation source 150 as a touch.
  • the return electrode of the control signal When the touch object 170 approaches or contacts the row electrode line 12i, the coupling capacitance between the row electrode line 12i and the column electrode group 130 changes, and the change of the touch signal current flowing through the touch signal sampling element 1611 is detected.
  • the row electrode line 12i is connected to the output end 151 of the touch excitation source 150 through the touch signal sampling component 1611, and other circuits of the touch signal detecting circuit 160 are connected to both ends of the touch signal sampling component 1611; All the remaining row electrode lines in the row electrode group 120 are also connected to the output end 151 of the touch excitation source 150, and the electrode lines 131, 132, ..., 13j-1 in the column electrode group 130 are also touched.
  • the output end 151 of the excitation source 150 is connected; the electrode lines 13j, ..., 13n in the column electrode group 130 are all connected to the output end 152 of the touch excitation source 150 as a return electrode of the touch signal.
  • the coupling capacitance between the electrode line 12i and the electrode lines 12i-1, 121+1 is changed.
  • the coupling capacitance between the row electrode line 12i and the column electrode group 130 is also changed, but since the output end of the touch excitation source 150 connected to each electrode is at the same output end 151 at the touched position, the flow
  • the change of the touch signal current on the touch signal sampling component 1611 is very small; when the touch object 170 approaches or contacts the portion where the row electrode line 12i is located between the column electrode lines 13j to 13n, the row electrode line 12i and the column electrode are caused.
  • the coupling capacitance between the groups 130 is changed.
  • the output terminals of the touch excitation source 150 connected to the row electrode lines 12i and the column electrode lines 13j, ..., 13n are different.
  • the change of the touch signal current on the control signal sampling component 1611 is large; by detecting the change of the touch signal current flowing through the touch signal sampling component 1611, the touched electrode line can be found.
  • the capacitive touch screen 100 shown in FIG. la includes a touch panel 110 and a touch circuit 140.
  • the touch panel 110 is provided with two sets of mutually orthogonal row electrode groups 120 spaced apart by an insulating layer (the row electrode lines 121, 122, ..., 12i-2 12i-l 12i, 12i+l, 12i+) 2 ..., 12m) and column electrode group 130 (the column electrode lines 131, 132, ..., 13j-2, 13j-1, 13j, 13j+1, 13j+2, ..., 13n).
  • the touch circuit 140 has a touch excitation source 150 and a touch signal detection circuit 160.
  • the touch signal frequency of the touch excitation source 150 is selected to be ⁇ or above.
  • the touch signal detecting circuit 160 is composed of a signal detecting channel 161, a data sampling channel 162, a data processing and timing controller 163; the signal detecting channel 161 has a touch signal sampling component 1611, a buffer 1612, a differential amplifying circuit 1613, and the like;
  • the sampling channel 162 has an analog-to-digital conversion circuit;
  • the data processing and timing control circuit 163 is a central processing unit (CPU MCU) having a data computing capability and a data output input interface, and the central processing unit has control software and data processing software.
  • the touch signal detecting circuit 160 of the touch circuit 140 causes the electrode line 12i in the row electrode group 120 to communicate with the output end 152 of the touch excitation source 150 as a return electrode of the touch signal; and select the electrode in the row electrode group 120.
  • the lines 12i-1 and 12i+1 are detection electrodes, and the electrode lines 12i-1 and 12i+1 are connected to the output end 151 of the touch excitation source 150 through the touch signal sampling component 1611, and the touch signal detecting circuit 160 is further The circuit is connected to both ends of the touch signal sampling component 1611; and the coupling capacitor C1 +1 between the electrode line 12i-1 and the electrode line 12i and the electrode line 12i forms a touch signal.
  • the touch circuit is closed; all the remaining row electrode lines of the row electrode group 120 and all the column electrode lines of the column electrode group 130 are directly connected to the output end 152 of the touch excitation source 150.
  • the touch signal from the touch excitation source output end 151 through the touch signal sampling component 1611 flows into the row electrode lines 12i-1 and 12i+1, and a part of the touch signal flows into the electrode line via the coupling capacitance d_r between the electrode line 12i-1 and the electrode line 12i.
  • the coupling capacitance C 1+1 between the electrode line 12i+1 and the electrode line 12i also flows into the electrode line 12i, and then flows back from the electrode line 12i to the touch excitation source output end 152; the other part passes through the row electrode line 12i-l And the coupling capacitance between the 12i+l and the column electrode lines flows into the column electrode line, and then flows back from the column electrode line to the touch excitation source.
  • the output 152, the flow of the touch signal on the closed touch loop, the equivalent circuit is shown in Figure Id.
  • the dielectric constant of the human body It is much larger than the dielectric constant of air, which makes the coupling capacitance and the capacitance of C 1+1 increase the capacitive reactance, and the current of the touch signal on the touch loop becomes correspondingly larger.
  • the equivalent circuit is shown in FIG.
  • the touch circuit 140 sequentially connects the electrode lines of the touch screen 100 to the output end 151 of the touch excitation source 150 in a scanning manner, and simultaneously connects the touch electrode lines adjacent to the two sides through the touch signal sampling component 1611.
  • the output end 152 of the excitation source 150 is controlled to connect all the remaining electrode lines to the output end 152 of the touch excitation source 150, and the touch signal detection circuit 160 detects the change of the touch signal current flowing through the touch signal sampling element 1611. And finding that the touch electrode line whose touch current current changes the most and exceeds a certain threshold is the touched electrode line; and the intersection position of the touched electrode line in the row electrode group 120 and the touched electrode line in the column electrode group 130 For the touch position of the finger.
  • the condition of the touched electrode line is determined.
  • the electrode line that detects that the amount of change of the touch signal exceeds a certain threshold is detected as the touched electrode line, so that the capacitive touch screen 100 allows simultaneous multi-touch.
  • the touch object 170 Since the touch signal flows on the closed loop formed between the touch control circuit 140 and the different touch electrode lines on the touch panel 110, the touch object 170 is close to a non-metallic object having a different dielectric constant and air dielectric constant. Or touching the touch screen 100, it is also possible to change the coupling capacitance between the adjacent touch electrode lines, causing a change in the touch signal current on the touch loop, so that a non-metallic touch object (such as a normal stylus) It can also be used to operate the capacitive touch screen 100; when the touch object 170 approaches or touches the touch screen 100 with a metal object, the metal object changes the effective coupling distance between adjacent touch electrode lines, thereby changing the touch. The coupling capacitances Cw and C 1+1 between the electrode lines cause a change in the touch signal current on the loop, so that a metal touch object (such as a metal stylus) can also be used to operate the capacitive touch screen 100.
  • the row electrode lines 12i-2, 12i and 12i+2 in the row electrode group 120 can communicate with the output end 151 of the touch excitation source 150 during the detection period as a return electrode of the touch signal;
  • the lines 12i-1 and 12i+1 are connected to the output end 152 of the touch excitation source 150 through the touch signal sampling component 1611, and the other circuits of the touch signal detecting circuit 160 are connected to both ends of the touch signal sampling component 1611; All of the remaining row electrode lines in the electrode set 120 and all of the column electrode lines of the column electrode set 130 are also in communication with the output end 152 of the touch excitation source 150.
  • the application product 200 of the capacitive touch screen shown in FIG. 2 includes a transparent touch panel 210 and a touch circuit.
  • the touch panel 210 is provided with two sets of mutually orthogonal row electrode groups 220 (having row electrode lines 221, 222, ..., 22 ⁇ - ⁇ 22 22 ⁇ + ⁇ ..., 22m) spaced apart by an insulating layer.
  • Column electrode group 230 (having column electrode lines 231, 232, ..., 23j-1, 23j, 23j+1, ..., 23n;).
  • the touch circuit 240 has a touch excitation source 250 and a touch signal detection circuit 260.
  • the output port of the touch excitation source 250 is 251.
  • the touch signal frequency of the touch excitation source 250 is selected;
  • the touch signal detection circuit 260 is composed of a signal detection channel 261, a data sampling channel 262, a data processing and timing controller 263; and the signal detection channel 261 has a touch Control signal sampling component 2611, buffers 2612 and 2613, signal filter 2614, differential amplification circuit 2615, etc., wherein signal filter 2614 has the ability to block the passage of frequency non- ⁇ signals; data sampling channel 262 has an analog to digital conversion circuit;
  • the timing control circuit 263 is a central processing unit (CPU, MCU) having data computing capability and a data output input interface, and the central processing unit has control software and data processing software.
  • the display system has a display screen 271, a display drive circuit 272, a backlight 273, a backlight drive circuit 274, a display system power supply 275, and the like.
  • the transparent touch panel 210 abuts on the front side of the display screen 271, and the backlight 273 also abuts the back side of the display screen 271.
  • the host circuit 280 has a host power source 281 and the like.
  • the touch signal detecting circuit 260 of the touch circuit 240 selects the electrode line 22i of the row electrode group 220 as a detecting electrode, and allows the electrode line 22i to communicate with the output end 251 of the touch excitation source 250 through the touch signal sampling component 2611.
  • the buffers 2612 and 2613 of the signal detecting circuit 260 are connected to both ends of the touch signal sampling element 2611, the signal filter 2614 is connected to the buffers 2612 and 2613, the differential amplifying circuit 2615 is connected to the signal filter 2614, and the electrodes in the row electrode group 220 are arranged.
  • the lines 22i-1 and 22i+1 are both connected to the output end 252 of the touch excitation source 250 as a return electrode of the touch signal; the coupling capacitance Cw between the electrode line 22i and the electrode line 22i-1, and the electrode line 22i a coupling capacitor C 1+1 between +1 forms a closed touch loop for the touch signal; all the remaining row electrode lines of the row electrode group 220 and all the column electrode lines of the column electrode group 230 are directly connected to the touch excitation source
  • the output 251 of 250 is in communication.
  • the host power supply 281 is connected to the display system power supply 275 of the display system.
  • the display system power supply 275 is connected to the display drive circuit 272 and the backlight drive circuit 274.
  • the display drive circuit 272 and the backlight drive circuit 274 are connected to the display screen 271 and the backlight 273, respectively.
  • the power supply end of the touch control circuit 250 and the power supply end of the touch signal detection circuit 260 are connected to the host power supply 281 through two inductive components 241 and 242.
  • the data processing of the touch signal detection circuit 260 is connected to the timing controller 263.
  • the data sampling channel 262 is connected to the signal detecting channel 261.
  • the touch signal sampling component 2611 of the signal detecting channel 261 is connected between the touch excitation source 250 and the electrode line of the touch panel 210, and the signal detecting channel 261 is differential.
  • the amplifying circuit 2615 is connected to the buffers 2612 and 2613 through the signal filter 2613, and the buffer 2612 is connected to the end of the touch signal sampling component 2611 connected to the electrode line of the touch panel 210.
  • the buffer 2613 is connected to the touch signal sampling component 2611 to connect the touch.
  • the end of the excitation source 250; the data processing and timing controller 263 is simultaneously coupled to the host circuit 280.
  • the body's dielectric constant is much larger than that of the air.
  • the dielectric constant makes the coupling capacitance and the capacitance of c 1+1 increase the capacitive reactance, and the current of the touch signal on the touch loop becomes correspondingly larger.
  • the detected electrode line can be found by detecting a change in the current of the touch signal flowing through the touch signal sampling element 2611.
  • the touch excitation source 250 outputs a touch signal to the electrode line of the touch panel 210, and flows into the display 271 electrode through the coupling capacitor C TD , flows into the display system power supply 275, flows into the host power supply 281, and then flows from the host power supply 281.
  • the tendency of the touch source to be excited is 250; however, since the inductance elements 241 and 242 are disposed on the connection line between the touch circuit 240 and the host power supply 281, the higher frequency touch signals cannot pass smoothly; the touch signals are in touch.
  • Excitation source 250, touch pad 210 electrode line and display screen 271 The smooth loop can not be obtained, which prevents the touch signal from flowing between the touch system and the display system, and avoids the coupling capacitance between the touch screen and the display screen to interfere with the touch detection; meanwhile, the signal detection channel 261
  • the signal filter 2614 also blocks the passage of other non- ⁇ interference signals, further reducing the impact of the interference signals on the touch detection.
  • the touch signal sampling component 2611 of the signal detecting channel 261 is connected between the touch excitation source 250 and the electrode line of the touch panel 210.
  • the differential amplifying circuit 2615 in the signal detecting channel 261 is connected to the buffers 2612 and 2613 through the signal filter 2614.
  • the buffer 2612 is connected to the end of the touch signal sampling component 2611 connected to the electrode line of the touch panel 210, and the buffer 2613 is connected to the end of the touch signal sampling component 2611 connected to the touch excitation source 250.
  • the end point of the touch signal sampling component 2611 connected to the touch excitation source 250 is a signal measurement reference point of the signal detection channel 261, and the signal measurement reference point can also be selected at other positions, that is, the buffer 2613 can be connected to the touch circuit 240.
  • the application product 300 of the capacitive touch screen shown in FIG. 3 includes a transparent touch panel 310 and a touch circuit.
  • the touch panel 310 is provided with two sets of mutually orthogonal row electrode groups 320 spaced apart by an insulating layer (the row electrode lines 321, 322, ..., 32 ⁇ - ⁇ 32i, 32 ⁇ + ⁇ ..., 32m) And column electrode group 330 (having column electrode lines 331, 332, ..., 33j-1, 33j, 33j+1, ..., 33n;).
  • the touch circuit 340 has a touch excitation source 350 and a touch signal detection circuit 360.
  • the output ports of the touch excitation source 350 are 351 and 352, and the touch signal frequency of the touch excitation source 350 is selected to be 400 ⁇ ; the output port of the touch excitation source 350 has a strobe filter 353 for the 400 ⁇ frequency signal; the touch signal
  • the detecting circuit 360 is composed of a signal detecting channel 361, a data sampling channel 362, a data processing and timing controller 363; the signal detecting channel 361 has a touch signal sampling component 3611, buffers 3612 and 3613, a differential amplifying circuit 3614, etc.;
  • the channel 362 has an analog-to-digital conversion circuit;
  • the data processing and timing control circuit 363 is a central processing unit (CPU, MCU) having a data operation capability and a data output input interface, and the central processing unit has control software and data processing software.
  • the display system has a display 371, a display driving circuit 372, a backlight 373, a backlight driving circuit 374, and a display system power supply 375.
  • the transparent touchpad 310 abuts the display 371, and the backlight 373 also abuts the back of the display 371.
  • the host circuit 380 has a host power source 381 and the like.
  • the touch signal detecting circuit 360 of the touch circuit 340 selects the electrode line 32i of the row electrode group 320 as a detecting electrode, and allows the electrode line 32i to communicate with the output end 351 of the touch excitation source 350 through the touch signal sampling component 3611.
  • the other circuits of the signal detecting circuit 360 are connected to both ends of the touch signal sampling component 3611; the electrode wires 32i-1 and 32i+1 in the row electrode group 320 are passed through the output of the gate filter 353 and the touch excitation source 350.
  • 352 is connected as a return electrode of the touch signal; and the coupling capacitance Cw between the electrode line 32i and the electrode line 32i-1 and the coupling capacitance C 1+1 between the electrode line 32i +1 form a closed touch of the touch signal.
  • the control circuit is configured to allow all of the remaining row electrode lines of the row electrode group 320 and all of the column electrode lines of the column electrode group 330 to directly communicate with the output terminal 351 of the touch excitation source 350.
  • the display system power supply 375 of the display system is connected to the host power supply 381 through two inductive components 376 and 377.
  • the display system power supply 375 is connected to the display driving circuit 372 and the backlight driving circuit 374.
  • the display driving circuit 372 and the backlight driving circuit 374 are respectively connected to the display screen. 371 and backlight 373.
  • the host power supply 381 is connected to the power supply end of the touch excitation circuit 350 and the touch signal detection circuit of the touch control circuit 340
  • the data processing and timing controller 363 of the touch signal detecting circuit 360 is connected to the data sampling channel 362, the data sampling channel 362 is connected to the signal detecting channel 361; the differential amplifying circuit 3614 in the signal detecting channel 361 is connected to the buffers 3612 and 3613.
  • the buffers 3612 and 3613 are connected to both ends of the touch signal sampling component 3611, and the touch signal sampling component 3611 of the signal detecting channel 361 is connected between the touch excitation source 350 and the electrode line of the touch panel 310; data processing and timing
  • the controller 363 is simultaneously connected to the host circuit 380.
  • the dielectric constant of the human body is much larger than that of the air.
  • the dielectric constant makes the coupling capacitance and the capacitance of C 1+1 increase and the capacitive reactance decreases, and the current of the touch signal on the touch loop becomes correspondingly larger.
  • the detected electrode line can be found by detecting a change in the current of the touch signal flowing through the touch signal sampling element 3611.
  • the touch excitation source 350 outputs a touch signal to the electrode line of the touch panel 310, and flows into the display 371 electrode through the coupling capacitor C TD , flows into the display system power supply 375, flows into the host power supply 381, and then flows from the host power supply 381.
  • the tendency to switch back to the excitation source 350 since the inductance elements 376 and 377 are disposed on the connection line between the display system power supply 375 and the host power supply 381, the higher frequency touch signals cannot pass smoothly; the touch signals are in touch.
  • the smooth circuit can not be obtained between the excitation source 350, the touch panel 310 electrode line and the display screen 371, thereby preventing the touch signal from flowing between the touch system and the display system, and avoiding the coupling capacitance between the touch screen and the display screen.
  • the touch detection generates interference; at the same time, the gate filter 353 in the touch loop also prevents other non-400KHZ interference signals from passing, further reducing the influence of the interference signal on the touch detection.
  • the hand-held application product 400 of the capacitive touch screen shown in FIG. 4 includes a transparent touch panel 410, a touch circuit 440, a display system, a host circuit 480, an outer casing 490, and the like.
  • the touch panel 410 is provided with two sets of mutually orthogonal row electrode groups 420 spaced apart by an insulating layer (the row electrode lines 421, 422, ..., 42 ⁇ - ⁇ 42i, 42i+1, ..., 42m) And the column electrode group 430 (the column electrode lines 431, 432, ..., 43j-1, 43j, 43j+1, ..., 43n).
  • the touch circuit 440 has a touch excitation source 450 and a touch signal detection circuit 460.
  • the touch signal frequency of the touch excitation source 450 is selected to be at or above; the touch signal detection circuit 460 is composed of a signal detection channel 461, a data sampling channel 462, a data processing and timing controller 463; and the signal detection channel 461 has a touch.
  • the data processing and timing control circuit 463 is a central processing unit (CPU) having a data computing capability and a data output input interface. , MCU), the central processing unit has control software and data processing software.
  • the display system has a display 471, a display driving circuit 472, a backlight 473, a backlight driving circuit 474, and a display system power supply 475.
  • the transparent touchpad 410 abuts the front side of the display 471, and the backlight 473 also abuts the back of the display 471.
  • the host circuit 480 has a host power source 481 and the like.
  • An electrode 491 is disposed on the outer casing 490.
  • the host power supply 481 is connected to the display system power supply 475 of the display system 470.
  • the display system power supply 475 is connected to the display drive circuit 472 and the backlight drive circuit 474.
  • the display drive circuit 472 and the backlight drive circuit 474 are connected to the display screen 471 and the backlight 473, respectively.
  • the touch circuit 440 touches the power end of the excitation source 450 and the touch
  • the power supply terminal of the signal detecting circuit 460 is connected to the host power source 481 through two inductive elements 441 and 442.
  • the data processing and timing controller 463 of the touch signal detecting circuit 460 is connected to the data sampling channel 462, and the data sampling channel 462 is connected to the signal detecting channel 461; the differential amplifying circuit 4614 in the signal detecting channel 461 is connected to the buffers 4612 and 4613, and the buffer 4612
  • the touch signal sampling component 4611 of the signal detecting channel 461 is connected between the touch excitation source 450 and the electrode line of the touch panel 410; the data processing and timing controller 463 are simultaneously connected.
  • the host circuit 480 is connected.
  • the touch signal detecting circuit 460 of the touch circuit 440 selects the electrode line 42i of the row electrode group 420 as a detecting electrode, and allows the electrode line 42i to communicate with the output end 451 of the touch excitation source 450 through the touch signal sampling component 4611.
  • the other circuits of the signal detecting circuit 460 are connected to both ends of the touch signal sampling element 4611; all the remaining row electrode lines of the row electrode group 420 and all the column electrode lines of the column electrode group 430 are directly connected to the output of the touch excitation source 450.
  • the end 451 is connected; the electrode 491 on the outer casing 490 serves as a return electrode of the touch signal, and the electrode 491 is connected to the output end 452 of the touch excitation source 450; when the human finger 4100 approaches or contacts the row electrode line 42i, the finger A coupling capacitor d is generated between the 4100 and the row electrode line 42i, and the touch excitation signal outputted by the touch excitation source 450 to the row electrode line 42i flows into the finger through the coupling capacitor G, and then flows into the product casing through the palm of the holding product.
  • the return electrode 491 on the body flows back from the return electrode 491 back to the touch excitation source 450; the touch excitation source, the touch panel electrode line, the finger and the electricity Coupling capacitance between the lines, a return electrode on the housing body composition touch circuit.
  • the detected electrode line can be found by detecting a change in the touch signal current flowing through the touch signal sampling element 4611.
  • the touch excitation source 450 outputs a touch signal to the electrode line of the touch panel 410, and flows into the display 471 electrode through the coupling capacitor C TD , flows into the display system power supply 475, flows into the host power supply 481, and then flows from the host power supply 481.
  • the tendency of the touch excitation source 450 is back; however, since the inductance elements 441 and 442 are disposed on the connection line between the touch circuit 440 and the host power source 481, the higher frequency touch signals cannot pass smoothly; the touch signals are in touch.
  • the excitation circuit 450, the touch panel 410 electrode line and the display screen 471 cannot obtain a smooth loop, thereby preventing the touch signal from flowing between the touch system and the display system, and avoiding the coupling capacitance between the touch screen and the display screen. Touch detection produces interference.
  • the water droplets on the surface of the touch panel 410 do not cause the connection between the touch panel electrode lines and the electrodes 491 on the outer casing 490, and the touch panel electrode lines and contacts cannot be formed.
  • the touch panel display 500 shown in FIG. 5 includes a display screen 510, a display driving circuit 540, a touch circuit 550, and a display/touch signal strobe circuit 560.
  • the display screen 510 is provided with two sets of mutually orthogonal row electrode groups 520 spaced apart by an insulating layer (the row electrode lines 521, 522, ..., 52 ⁇ - ⁇ 52i, 52i+1, ..., 52m) And column electrode group 530 (with column electrode lines 531, 532, ..., 53j-1, 53j, 53j+1, ..., 53n;).
  • the touch circuit 550 has a touch excitation source 570 and a touch signal detection circuit 580.
  • Touch signal detection circuit 580 It is composed of a signal detection channel 581, a data sampling channel 582, a data processing and timing controller 583; the signal detection channel 581 has a touch signal sampling component 5811, buffers 5812 and 5813, a differential amplification circuit 5814, etc.; the data sampling channel 582 has The analog-to-digital conversion circuit; the data processing and timing control circuit 583 is a central processing unit (CPU, MCU) having data computing capability and a data output input interface, and the central processing unit has control software and data processing software.
  • CPU central processing unit
  • the display driving circuit 540 and the touch circuit 550 are connected to the display screen 510 through the display/touch signal gating circuit 560; the display/touch signal gating circuit 560 or the display driving circuit 540 is connected to the display screen 510, or touch Circuit 550 is in communication with display screen 510.
  • the display/touch signal gating circuit 560 causes the display driving circuit 540 to communicate with the display screen 510 to transmit a display driving signal to the display screen 510, and the display screen 510 is in a display state.
  • the display/touch signal gating circuit 560 causes the touch circuit 550 to communicate with the display screen 510 to transmit a touch signal to the display screen 510, and the display screen 510 is in the touch detection state.
  • the touch signal detecting circuit 580 of the touch circuit 550 selects the electrode line 52i in the row electrode group 520 as the detecting electrode, and lets the electrode line 52i pass the touch signal sampling element 5811 and the touch excitation source.
  • the output end 571 of the 570 is connected, and the other circuits of the touch signal detecting circuit 580 are connected to both ends of the touch signal sampling component 5811.
  • the electrode wires 52i-1 and 52i+1 in the row electrode group 520 are connected to the touch excitation source 570.
  • the output end 572 is connected to serve as a return electrode of the touch signal; and the touch signal is formed by the coupling capacitance Cw between the electrode line 52i and the electrode line 52i-1 and the coupling capacitance C 1+1 between the electrode line 52i+1
  • the closed touch loop is closed; all the remaining row electrode lines of the row electrode group 520 and all the column electrode lines of the column electrode group 530 are also in communication with the output end 571 of the touch excitation source 570.
  • the touch signal flowing out from the touch excitation source output terminal 571 flows into the row electrode line 52i via the touch signal sampling component 5811, and flows into the electrode line 52i-1 through the coupling capacitance d_r between the electrode line 52i and the electrode line 52i-1.
  • the coupling capacitance C 1+ r between the electrode line 52i and the electrode line 52i+1 flows into the electrode line 52i+1, and then flows back from the electrode lines 52i-1 and 52i+1 to the touch excitation source output terminal 572, and the touch signal is The flow on the closed touch loop.
  • the dielectric constant of the human body It is much larger than the dielectric constant of air, which makes the coupling capacitance and the capacitance of C 1+1 increase the capacitive reactance, and the current of the touch signal on the touch loop becomes correspondingly larger.
  • the touch control circuit 550 sequentially connects the electrode lines of the display screen 510 through the touch signal sampling component 5811 to the output end 571 of the touch excitation source 570 in a scanning manner, and simultaneously connects the touch electrode lines adjacent to each other on the touch electrodes.
  • the output terminal 572 of the excitation source 570 is configured to connect all the remaining electrode lines to the output end 571 of the touch excitation source 570, and the touch signal detection circuit 580 detects the change of the touch signal current flowing through the touch signal sampling component 5811.
  • the touch electrode line that finds that the touch signal current changes the most and exceeds a certain threshold is the touched electrode line; the intersection position of the touch electrode line in the row electrode group 520 and the touched electrode line in the column electrode group 530 is the finger Touch location.
  • the condition of the touched electrode line is determined, and only the electrode line that detects that the amount of change of the touch signal passing through exceeds a certain threshold is detected as the touched electrode line, so that the touch panel display 500 allows simultaneous multi-touch.
  • the touch signal is formed between the touch control circuit 550 and the different touch electrode lines on the display screen 510.
  • the coupling capacitance ⁇ and ⁇ + between adjacent touch electrode lines can also be changed.
  • the change of the touch signal current on the touch circuit causes the non-metallic touch object (such as the usual stylus) to be used to operate the touch panel display 500; the touch object 580 approaches or touches the display with the metal object.
  • the metal object changes the effective coupling distance between adjacent touch electrode lines, thereby changing the coupling capacitance Cw and between the touch electrode lines. 1+1 , causing a change in the touch signal current on the loop, so that a metal touch object (such as a metal stylus;) can also be used to operate the touch panel display 500.
  • FIG. 6 shows a handheld application product 600 with a touch panel display, including a display screen 610, a display driving circuit 640, a touch circuit 650, a display/touch signal strobe circuit 660, a host circuit 670, and a housing. Body 680 and so on.
  • the display screen 610 is provided with two sets of mutually orthogonal row electrode groups 620 spaced apart by an insulating layer (the row electrode lines 621, 622, ..., 62 ⁇ - ⁇ 62i, 62i+1, ..., 62m) And column electrode group 630 (with column electrode lines 631, 632, ..., 63j-1, 63j, 63j+1, ..., 63n;).
  • the touch circuit 650 has a touch excitation source 651 and a touch signal detection circuit 652.
  • the touch signal detection circuit 652 has a touch signal sampling component 6521 and the like.
  • the host circuit 670 has a host power source 671 and the like.
  • An electrode 681 is disposed on the outer casing 680. The power supply end of the touch circuit 650 touch excitation source 651 and the power supply end of the touch signal detection circuit 652 are connected to the host power supply 671 through two inductance elements 653 and 654.
  • the display driving circuit 640 and the touch control circuit 650 are connected to the display screen 610 through the display/touch signal strobe circuit 660; the display/touch signal strobe circuit 660 or the display driving circuit 640 is connected to the display screen 610, or touch Circuitry 650 is in communication with display screen 610.
  • the display/touch signal gating circuit 660 causes the display driving circuit 640 to communicate with the display screen 610 to transmit a display driving signal to the display screen 610, and the display screen 610 is in a display state.
  • the display/touch signal strobe circuit 660 causes the touch circuit 650 to communicate with the display screen 610 to transmit a touch signal to the display screen 610, and the display screen 610 is in a touch detection state.
  • the touch signal detecting circuit 652 of the touch circuit 640 selects the electrode line 62i in the row electrode group 620 as the detecting electrode, and lets the electrode line 62i pass the touch signal sampling element 6521 and the touch excitation source.
  • the output end 6511 of the 651 is connected, and other circuits of the touch signal detecting circuit 652 are connected to both ends of the touch signal sampling element 6521; all the remaining row electrode lines of the row electrode group 620 and all the column electrode lines of the column electrode group 630 are also Both are connected to the output end 6511 of the touch excitation source 651; the electrode 681 on the outer casing 680 serves as a return electrode of the touch signal, and the electrode 681 is connected to the output end 6512 of the touch excitation source 651; when the human finger 690 is close to Or when the row electrode line 62i is contacted, a coupling capacitor d is generated between the finger 690 and the row electrode line 62i, and the touch excitation signal outputted by the touch excitation source 651 to the row electrode line 62i flows into the finger through the coupling capacitor G, and then The palm of the product holding the product flows into the return electrode 681 on the outer casing of the product, and then flows back from the return electrode 681 to the touch excitation source 651;
  • the water droplets on the surface of the display screen 610 do not cause the connection between the display electrode line and the electrode 681 on the outer casing 680 of the product, and the display electrode line and the surface of the display screen cannot be formed.
  • the outer casing electrode and the touch signal loop of the touch excitation source Only the operator holding the application When the finger touches the touch panel, the touch excitation source, the touch panel electrode line, the coupling capacitance between the finger and the electrode line, and the touch signal loop formed by the return electrode on the outer casing are formed.
  • the water droplets on the surface of the display screen 610 will not affect the judgment of the touch circuit by the touch circuit.
  • the application product 700 of the capacitive touch screen shown in FIG. 7 includes a touch electrode group 710, a touch circuit 720, a display system, and a host circuit 760.
  • the display system has a display 751, a display driving circuit 752, a backlight 753, a backlight driving circuit 754, a display system power supply 755, and the like, and the backlight 753 abuts against the back of the display screen 751.
  • the host circuit 760 has a host power source 761 and the like.
  • a set of mutually dissimilar line-shaped electrode groups 710 are provided (the line-shaped electrode lines 711, 712, ..., 71i-1, 71i, 71i+1, ...
  • the touch circuit 720 has a touch excitation source 730 and a touch signal detection circuit 740.
  • the output ports of the touch excitation source 730 are 731 and 732, the touch signal frequency of the touch excitation source 730 is selected to be 400 KHz, and the output filter 732 of the touch excitation source 730 has a gate filter 733 for the 400 KHz frequency signal;
  • the control signal detecting circuit 740 is composed of a signal detecting channel 741, a data sampling channel 742, a data processing and timing controller 743; the signal detecting channel 741 has a touch signal sampling component 7411, buffers 7412 and 7413, a signal filter 7414, and a difference.
  • CPU central processing unit
  • MCU central processing unit
  • the touch signal detecting circuit 740 of the touch circuit 720 selects the electrode line 71i of the electrode group 710 as a detecting electrode, and allows the electrode line 71i to communicate with the output end 731 of the touch excitation source 730 through the touch signal sampling element 7411 to allow the electrode group
  • the electrode lines 71i-1 and 71i+1 in 710 are both connected to the output end 732 of the touch excitation source 730 as a return electrode of the touch signal; and the coupling capacitance Cw between the electrode line 71i and the electrode line 71i-1, and The coupling capacitance C 1+1 between the electrode lines 71i+ 1 forms a closed touch loop of the touch signal; and all the remaining electrode lines in the electrode group 710 are also connected to the output end 731 of the touch excitation source 730.
  • the host power supply 761 is connected to the display system power supply 755 of the display system, the display system power supply 755 is connected to the display drive circuit 752 and the backlight drive circuit 754, and the display drive circuit 752 and the backlight drive circuit 754 are connected to the display screen 751 and the backlight 753, respectively.
  • the touch control circuit 720 touches the power supply end of the excitation source 730 and the power supply end of the touch signal detection circuit 740, and connects to the host power supply 761 through two signal isolation devices 721 and 722 that can not smoothly pass the 400-inch touch signal;
  • the data processing and timing controller 743 of the circuit 740 is connected to the data sampling channel 742, and the data sampling channel 742 is connected to the signal detecting channel 741.
  • the touch signal sampling component 7411 of the signal detecting channel 741 is connected to the touch excitation source 730 and the touch electrode group 710. Between the electrode lines, the differential amplifying circuit 7415 in the signal detecting channel 741 is connected to the buffer 7412 and the buffer 7413 via the signal filter 7414, and the buffer 7412 is connected to the touch signal sampling element 7411 connected to the electrode line of the touch electrode group 710. The end point, the buffer 7413 is connected to the end of the touch signal sampling component 7411 connected to the touch excitation source 730; the data processing and timing controller 743 is simultaneously connected to the host circuit 760.
  • the dielectric constant of the human body is much larger than the dielectric constant of the air.
  • the capacitance of the coupling capacitors Ci-1 and Ci+1 is increased, and the capacitive reactance is reduced, and the current of the touch signal on the touch loop is correspondingly increased.
  • the electrode line Since the detecting end of the detecting electrode and the return electrode are located in the same direction of the touch electrode group 710, the electrode line has a certain resistance value, and when the finger touches different positions of the electrode line, the electrode line segment from the touch excitation source output port to the touch point The line resistance value is different, and the resistance value on the touch circuit is different.
  • the current of the touch signal varies with the position of the finger 770 on the touched electrode line.
  • the touch circuit 720 selects the electrode lines of the electrode group 710 as detection electrodes one by one in a scanning manner, and determines the size of the touched electrodes by comparing the magnitudes of the touch signals on different electrode lines to change the size of the touch signals flowing through the touched electrodes. Position the touch point on the touched electrode.
  • the electrode lines of the touch electrode group 710 also have a coupling capacitance C TD between the electrodes of the display screen 751.
  • the touch signal outputted by the touch excitation source 730 to the touch electrode line has a contact capacitance C TD flowing into the display 751 electrode, then flowing into the display system power supply 755, flowing into the host power supply 761, and then flowing back from the host power supply 761.
  • the tendency of the excitation source 730 is controlled; however, since the host power supply 761 is connected to the power supply end of the touch excitation source 730 and the power supply end of the touch signal detection circuit 740 through the signal isolation devices 721 and 722, the touch signal of 400 KHz frequency cannot pass smoothly.
  • the touch signal cannot obtain a smooth loop between the touch excitation source 730, the touch electrode group 710 electrode line, the display screen 751, the display system power source 755, and the host power source 761, thereby preventing the touch signal from being in the touch system and the display.
  • Streaming between systems prevents the coupling capacitance between the touch screen and the display screen from interfering with the touch detection.
  • the gate filter 733 in the touch loop also prevents other non-400KHZ interference signals from passing, further reducing the interference.
  • the effect of the signal on the touch detection; the signal filter 7414 in the touch signal detection circuit 740 also allows the non-400KHz interference signal to not affect the touch detection. Effect.
  • the touch points of different electrode lines can be distinguished by comparing the sizes of touch signals on different electrode lines in adjacent areas; for different touch points on the same electrode line, The touch points are distinguished by the order of time; when there are two touch points moving in the direction parallel to the electrode group 710, since the electrode lines in the electrode group 710 are broken lines, the movement of the touch points in any direction is different. Time passes through different electrode lines, allowing us to determine the position and direction of the touch point.
  • the handheld application product 800 of the capacitive touch screen shown in FIG. 8 includes a transparent touch panel 810, a touch circuit 830, a display system, a host circuit 870, and an outer casing 880.
  • the display system has a display 861, a display drive circuit 862, a backlight 863, a backlight drive circuit 864, and a display system power supply 865.
  • the transparent touch panel 810 abuts the display 861 and the backlight 863 abuts the back of the display 861.
  • the host circuit 870 has a host power source 871 and the like.
  • An electrode 881 is disposed on the outer casing 880.
  • a transparent planar electrode 811 is disposed on a surface of the touch panel 810 facing the display screen 861; a set of folded-line electrode groups 820 (with a polygonal electrode line) that are not intersecting each other are disposed on the surface of the touch panel 810 facing the user. 821, 822, ..., 82 ⁇ - ⁇ 82i, 82i+l, ..., 82m), adjacent electrode lines have lead ends in different directions, and the electrode lines are made of ITO transparent material having a certain resistance value.
  • the touch circuit 830 has a touch excitation source 840 and a touch signal detection circuit 850.
  • the output ports of the touch excitation source 840 are 841 and 842, and the touch signal frequency of the touch excitation source 840 is selected at 400 KHz; the touch signal detection circuit 850 is composed of signal detection channels 851 and 852, data sampling channels 853 and 854, and data.
  • the processing and timing controller 855 is composed; the signal detecting channel 851 has a touch signal sampling component 8511, buffers 8512 and 8513, a signal filter 8514, and a difference The sub-amplifier circuit 8515 and the like; the signal detecting channel 852 has a touch signal sampling component 8521, buffers 8522 and 8523, a signal filter 8524, a differential amplifying circuit 8525, etc.; the data sampling channel 853 has an analog-to-digital conversion circuit, and the data sampling channel 854 has The analog-to-digital conversion circuit; the data processing and timing control circuit 855 is a central processing unit (CPU, MCU) having a data operation capability and a data output input interface, and the central processing unit has control software and data processing software.
  • CPU central processing unit
  • the touch signal detecting circuit 850 of the touch circuit 830 simultaneously selects the electrode line 82i-1 and the electrode line 82i in the electrode group 820 as the detecting electrode, and the electrode line 82i-1 passes through the touch signal sampling element 8511 and the touch excitation source 840.
  • the output terminal 841 is connected, and the electrode line 82i is also connected to the output end 841 of the touch excitation source 840 through the touch signal sampling component 8512, so that the remaining electrode lines in the electrode group 820 are directly connected to the output end of the touch excitation source 840.
  • the electrode 881 on the outer casing 880 serves as a return electrode of the touch signal, and the electrode 881 is connected to the output end 842 of the touch excitation source 840.
  • the host power supply 871 is connected to the display system of the display system.
  • Power supply 865, display system power supply 865 is connected to the display drive circuit 862 and the backlight drive circuit 864, the display drive circuit 862 and the backlight drive circuit 864 are connected to the display 861 and the backlight 863, respectively.
  • the power supply terminal of the touch excitation source 840 and the power supply terminal of the touch signal detection circuit 850 are connected to the host power supply 871 through two signal isolation devices 831 and 832 that fail to pass the 400KHz touch signal.
  • the touch signal sampling component 8511 of the signal detection channel 850 of the touch signal detection circuit 850 is connected between the touch excitation source 840 and the electrode line 82i-1 of the touch electrode group 820, and the buffer 8512 is connected to the touch signal sampling component 8511. The end of the electrode line 82i-1 is connected.
  • the buffer 8513 is connected to the end of the touch signal sampling component 8511 connected to the touch excitation source 840.
  • the input of the differential amplifier circuit 8515 in the signal detection channel 851 is connected to the buffer 8512 through the signal filter 8514.
  • the output end of the differential amplifying circuit 8515 is connected to the input end of the data sampling channel 853; the touch signal sampling component 8521 of the signal detecting channel 852 is connected between the touch excitation source 840 and the electrode line 82i of the touch electrode group 820,
  • the buffer 8522 is connected to the end of the touch signal sampling component 8521 connecting the electrode line 82i.
  • the buffer 8523 is connected to the end of the touch signal sampling component 8521 connected to the touch excitation source 840, and the input end of the differential amplification circuit 8525 in the signal detection channel 852.
  • the buffers 8522 and 8523 are connected through a signal filter 8524, and the output terminal of the differential amplifying circuit 8525 is connected.
  • Data sampling input channel 854; and data sampling channel 853 are respectively connected to the output terminal 854 and the timing control data processing unit 855 of two different ports; data processing and timing control circuit 870 to connect the host 853 simultaneously.
  • a coupling capacitor Cw is generated between the finger 890 and the electrode line 82 ⁇ -1, and the touch excitation signal output from the touch excitation source 840 to the electrode line 82i-1 is output.
  • the coupling capacitor flows into the finger, and then flows into the return electrode 881 on the outer casing of the product through the palm of the holding product, and then flows back from the return electrode 881 to the touch excitation source 840; a coupling is formed between the finger 890 and the electrode line 82i.
  • the touch circuit is composed of a touch excitation source, a touch panel electrode line, a coupling capacitance between the finger and the electrode line, and a return electrode on the outer casing.
  • the detected electrode line can be found by detecting a change in the current of the touch signal flowing through the touch signal sampling elements 8511 and 8512. Since the electrode lines 82i-1 and 82i have the terminals in different directions, the electrode lines have a certain resistance value, and when the fingers touch different positions of the electrode lines 82i-1 and 82i, from the touch excitation source output port to the electrode line 82i- l When the line resistance value of the touch point is large, from the touch excitation source output port to the touch point on the electrode line 82i The line resistance value is small, and the ratio of the current of the touch signals on the electrode lines 82i-1 and 82i varies depending on the position of the finger 890 on the touched electrode line.
  • the touch circuit 830 sequentially selects the pair of electrode lines of the electrode group 820 as the detecting electrodes in a scanning manner, and determines the touched electrodes by comparing the sizes of the touch signals on different electrode lines to flow through the pair of touched electrodes. The ratio of the signals positions the touch point on the touched electrode.
  • the touch panel 810 is in close proximity to the display screen 861. Since the touch panel 810 has a planar electrode 811 facing the display screen 861, the planar electrode 811 is connected to the ground end of the host power supply 871 to prevent touch.
  • the signal is streamed between the touch system and the display system to prevent the coupling capacitance between the touch screen and the display screen from interfering with the touch detection. Meanwhile, the signal filters 8514 and 8524 in the touch signal detection circuit 850 also allow non-400KHz. The interference signal cannot affect the effect of touch detection.
  • the touch points of different electrode lines can be distinguished by comparing the sizes of touch signals on different electrode lines in adjacent areas; for different touch points on the same electrode line, The touch points are distinguished by the order of time; when there are two touch points moving in the direction parallel to the electrode group 820, since the electrode lines in the electrode group 820 are broken lines, the movement of the touch points in any direction is different. Time passes through different electrode lines, allowing us to determine the position and direction of the touch point.

Description

说 明 书 一种电容式触控屏
技术领域
本发明涉及触控屏， 尤其涉及电容式触控屏。 背景技术
触摸是人类最重要的感知方式,是人与机器进行互动的最自然的方式。 触控屏发 展至今已广泛用于个人计算机、 智能电话、 公共信息、 智能家电、 工业控制等众多 领域。 在目前的触控领域， 主要有电阻式触控屏、 光电式触控屏、 超声波式触控屏、 平面电容式触控屏， 近年来投射电容式触控屏发展迅速。
电阻式触控屏仍是目前市场上的主导产品，但电阻式触控屏的双层基板的结构， 使得触控屏和显示面板层叠在一起使用时， 触控屏的反光非常影响显示的亮度、 对 比度、 色饱和度等显示品质， 使整个显示质量大大下降， 而加大显示面板背光的亮 度， 还会使功耗大涨； 模拟式电阻触控屏还存在定位漂移的问题， 不时要进行位置 校准； 另外， 电阻式触控屏电极接触的工作方式， 又使得触控屏的寿命较短。
红外线式触控屏和超声波式触控屏不会影响显示质量。 但红外线式触控屏和超 声波式触控屏成本高， 水滴和尘埃都会影响触控屏工作的可靠性， 特别是红外线式 触控屏和超声波式触控屏机构复杂、 功耗大， 使得红外线式触控屏和超声波式触控 屏基本无法应用在便携式产品上。
平面电容式触控屏的单层基板的结构， 使得触控屏和显示面板层叠在一起使用 时， 触控屏对显示质量的影响不大。 但平面电容式触控屏也存在定位漂移的问题， 不时要进行位置校准； 水滴也会影响触控屏工作的可靠性； 特别是平面电容式触控 屏功耗大、 成本高， 也让平面电容式触控屏基本无法应用在便携式产品上。
投射电容式触控屏仍然可以是单层基板结构， 也使得触控屏和显示面板层叠在 一起使用时， 触控屏对显示质量的影响不大。 但投射电容式触控屏是通过测量手指 或其他触控物对触控屏电极间耦合电容的影响， 实际是通过测量手指或其他触控物 对触控屏电极充放电的影响， 来探测手指或其他触控物在触控屏上的位置。 定位点 需要经过模拟计算， 而非真正的数字式触控屏。 制造和使用环境中的分布电容都会 影响触控屏工作的可靠性， 显示驱动信号及其他电信号的干扰都会影响触控屏的工 作， 水滴也会影响触控屏工作的可靠性； 另外， 投射电容式触控屏对探测电极线的 电阻值方面有较高要求， 使得和显示面板层叠在一起使用的投射电容式触控屏的探 测电极线， 不能只有如 ιτο样的低电导率透明电极层， 还要有如金属类的高电导率 电极层， 制做工艺复杂、 成本高， 特别是在大尺寸、 甚至超大尺寸触控屏方面成本 过高。
目前的电容式触控屏， 无论是平面电容式触控屏还是投射电容式触控屏， 在与 显示屏重叠使用时， 如果没有在显示屏与触控屏之间设置屏蔽层， 显示屏上的显示 信号或显示状态， 会通过显示屏与触控屏间的耦合电容对触控信号产生干扰， 影响 到触控屏工作的可靠性。 如果在显示屏与触控屏之间设置屏蔽层， 屏蔽层有会减低 触控屏的透射率影响显示质量， 还会带来成本的增加； 如果不在显示屏与触控屏之 间设置屏蔽层， 而是以计算和甄别判断软件来消除显示的干扰， 也会耗用相当的计 算资源， 使探测速度变慢成本增高。
电容式触控屏的另一个的弱点是， 只可以用手指作为触控物来操作触控屏。 当 操作者带上手套进行触控时， 电容式触控屏的反应会变得非常迟钝， 甚至不能正常 工作， 更不可以用常规的非金属触控笔操作触控屏。
另外， 电容式触控屏还存在着防水性能差的问题。 触控屏上的水滴甚至是水气 使得电容式触控屏周边环境的介电系数发生变化， 使得电容式触控屏的可靠性出现 问题。 发明内容
本发明就是为了提供一种技术解决方案， 让电容式触控屏既可以排除显示对触 控探测的干扰， 又可以让操作者带上手套顺利工作； 既可以排除显示对触控探测的 干扰， 又可以在潮湿或有水滴的环境下正常工作； 实现电容式触控屏的高分辨率。
本发明的基本技术思路是： 在电容式触控屏或具有电容式触控屏的应用产品上 建立触控信号的回流电极， 将用于探测触控信号变化的触控检测电极和触控回流电 极分别连接在触控激励源的不同输出端， 在触控激励源、 触控检测电极、 触控回流 电极、 以及触控检测电极与触控回流电极间的耦合电容间形成闭合的触控回路， 从 触控激励源流入触控检测电极的触控信号再从触控回流电极流回触控激励源； 再将 触控系统与其他系统隔离开来， 防止不同系统间信号的串扰， 让触控信号在封闭系 统中流动； 通过检测特定频率的或其他特定特征的触控信号电流的变化来获取触控 信息， 从而防止其他信号或其他环境物质对触控探测的干扰。
本发明的电容式触控屏基本工作原理是： 在触控板以绝缘层相间隔的不同层上 分别设置两组相交的触控电极组， 触控电路具有触控激励源和触控信号检测电路； 让触控屏上的两条邻近的触控电极线分别连通触控激励源两个不同的输出端， 一条 作为触控检测电极， 一条作为触控回流电极。 从触控激励源一个输出端流出的触控 信号， 经触控信号采样元件流入与其相连的触控电极线上， 经不同触控电极线间的 耦合电容流入与检测触控电极所连通的触控激励源不同输出端的触控电极线， 再从 与被检测的触控电极所连通的触控激励源不同输出端流回到触控激励源， 触控信号 在闭合的触控回路上的流动。 当人的手指或其他触控物靠近或接触两条连通触控激 励源不同输出端的触控电极线时， 手指或其他触控物改变了不同触控电极线间的耦 合电容， 耦合电容的改变让触控回路上触控信号的电流也相应发生改变。 触控电路 以扫描方式顺序地让触控屏相邻的两条触控电极线连通触控激励源两个不同的输出 端， 并同时触控信号检测电路检测输出端上触控信号电流的变化， 找出触控信号电 流变化最大的或电流变化超过某阈值的触控电极线， 从而找出手指或其他触控物在 触控板上的位置。
由于触控信号是在触控电路与触控板上的不同触控电极线间所形成的闭合回路 上流动， 介电系数与空气介电系数不同的非金属触控物靠近或接触触控屏时， 也可 以改变不同触控电极线间的耦合电容， 造成触控回路上触控信号电流的变化， 让通 常的非金属触控笔也可以用于操作电容式触控屏；金属触控物靠近或接触触控屏时， 金属触控物改变了不同触控电极线间耦合电容电极的有效耦合距离， 从而改变了触 控电极线间的耦合电容， 造成回路上触控信号电流的变化， 让金属触控物也可以用 于操作电容式触控屏。
由于触控信号是在触控电路与触控板上的不同触控电极线间所形成的闭合回路 上流动， 触控物改变不同触控电极线间的耦合电容， 造成触控回路上触控信号电流 的变化； 也就是只要改变回路内器件的特性和参数， 就可以造成触控回路上触控信 号电流的变化， 并不需要从触控屏的触控电极线上引走泄漏电流， 来让触控信号检 测电路获得触控信息。 这样就可以将触控系统 (触控板和触控电路；)与显示系统 (包括 显示屏、 背光源及其驱动电路)和与主机电路隔离开来， 特别是将触控电路电源与触 控屏重叠使用的显示电路电源和与主机电源隔离开来； 所谓隔离就是在触控电路与 主机和与显示电路间设置隔离器， 让触控信号不能顺利地在两个电路间流动。这样， 在触控屏与显示屏重叠使用时， 触控信号就无法从触控屏和触控电路上流入显示电 路或主机电路再流回触控电路， 避免触控屏、 触控电路与显示电路间和与主机电路 间所存在的耦合对触控探测产生干扰。
触控屏上的触控信号回路使得， 只有在触控物同时触及触控检测电极和触控回 流电极时， 才会影响触控回路上触控信号电流的变化， 减少了触控信号在触控屏各 条触控电极之间的串扰流动； 并且可以同时对多条电极线施加触控激励信号， 进一 步地减少触控信号的串扰流动， 提高对被触电极判断的准确性， 实现空间数字化的 电容式触控屏。 将触控电极线做得足够细密， 触控屏上的触控回路在空间上就非常 细小， 实现高精度的电容式触控屏。 以检测各条电极线上触控信号变化量的相对值 来确定被触电极线， 可以降低对电极线的电阻值方面的要求， 实现大尺寸、 甚至超 大尺寸的电容触控屏。
当触控屏的表面落有水滴时， 由于水的介电系数比空气的介电系数大很多， 有 水滴处触控电极间的耦合电容就会发生变化， 从而改变触控信号电流的大小， 造成 触控电路误判为操作者的触控。 为避免误判的产生， 在手持式应用产品外壳体上设 置电极， 并选择外壳体上的电极为触控回流电极， 操作者持握应用产品手掌接触产 品外壳体， 手指靠近或触摸触控屏时， 手指与触控电极线间形成耦合电容， 电极线 上的触控激励信号就会通过此耦合电容部分流入手指， 通过持握应用产品的手掌流 入应用产品外壳体上的触控回流电极， 再从触控回流电极流回到触控激励源， 形成 触控信号在闭合回路上的流动。 触控屏表面的水滴并不会造成触控电极与应用产品 外壳体上触控回流电极间的连接， 就无法形成触控激励源、 触控检测电极和触控回 流电极的闭合回路， 也就不会影响到触控电路对触控信号的判断。
本发明的技术问题通过以下的技术方案予以解决：
一种电容式触控屏， 包括触控基板和触控电路， 触控电路具有触控激励源和触 控信号检测电路， 触控基板上设置有触控电极组； 触控基板上设置有不少于两组触 控电极时， 各组触控电极设置在不同的触控基板上或以绝缘层相隔离设置在同一触 控基板上； 触控基板设置在应用产品上， 应用产品具有显示系统 (包括显示屏及其驱 动电路、 背光源及其驱动电路)； 触控激励源的第一输出端用于在检测时段的至少部 分时刻对连接的电极线施加触控信号； 触控信号检测电路用于在检测时段的至少部 分时刻选择其中至少部分电极线为触控检测电极，来探测该部分电极线是否被触碰; 所述触控检测电极是指在对该电极施加有触控信号的同时， 还检测流经该电极触控 信号变化的电极； 触控电路在选择部分电极为检测电极的同时， 还选择触控基板的 部分电极线为触控回流电极； 所述触控回流电极是指， 在对触控检测电极施加触控 信号并检测流经其触控信号变化的时刻， 连通于触控激励源的第二输出端或连通于 另一触控激励源， 为检测电极上的触控信号提供回流通路的触控电极。
另一种方案是： 一种电容式触控屏， 包括触控基板和触控电路， 触控电路具有 触控激励源和触控信号检测电路， 触控基板上设置有触控电极组； 触控基板上设置 有不少于两组的触控电极时， 各组触控电极设置在不同的触控基板上或以绝缘层相 隔离设置在同一触控基板上； 触控基板设置在应用产品上， 应用产品具有显示系统 (包括显示屏及其驱动电路、背光源及其驱动电路)；触控激励源的第一输出端用于在 检测时段的至少部分时刻对连接的电极线施加触控信号； 触控信号检测电路用于在 检测时段的至少部分时刻选择其中至少部分电极线为触控检测电极， 来探测该部分 电极线是否被触碰； 所述触控检测电极是指在对该电极施加有触控信号的同时， 还 检测流经该电极触控信号变化的电极； 应用产品外壳体上设置有电极； 触控电路选 择应用产品外壳体上的电极为触控回流电极； 所述触控回流电极是指， 在对触控检 测电极施加触控信号并检测流经其触控信号变化的时刻， 连通于触控激励源的第二 输出端或连通于另一触控激励源， 为检测电极上的触控信号提供回流通路的触控电 极。
本发明的技术问题通过以下的技术方案进一步予以解决：
根据本发明的另一个具体方面， 所述触控回流电极是部分的或所有的与触控检 测电极不相交的电极线， 或是部分的或所有的与触控检测电极相交的电极线， 或是 部分的或所有的与触控检测电极相交的和不相交的电极线。
根据本发明的另一个具体方面， 所述与触控检测电极不相交的触控回流电极是 与触控检测电极相邻的一侧或两侧的电极线。
根据本发明的另一个具体方面， 所述触控基板是挠性的或硬性的透明基板。 根据本发明的另一个具体方面， 所述触控基板与平板显示屏合用基板。
根据本发明的另一个具体方面， 所述触控电极是显示屏电极。
根据本发明的另一个具体方面， 所述触控基板上连接触控电路的电极线设置于 触控基板的触摸面或非触摸面。
根据本发明的另一个具体方面， 所述触控基板上除具有连接触控电路的电极线 外， 还具有不连接触控电路的电极
根据本发明的另一个具体方面， 所述触控电路同时对触控基板上的多条触控检 测电极进行触控探测。
根据本发明的另一个具体方面， 所述触控基板上多条触控检测电极是并联在 起进行检测的。
根据本发明的另一个具体方面， 所述触控基板上多条触控检测电极是分别独立 进行检测的。 根据本发明的另一个具体方面， 所述多条独立检测的触控检测电极所连通的触 控激励源输出端是不同的。
根据本发明的另一个具体方面， 所述触控检测电极与触控回流电极所连通的同 一触控激励源不同输出端上的或不同触控激励源输出端上的触控信号是不同的。
根据本发明的另一个具体方面， 所述触控信号的不同是指触控信号的幅值、 相 位、 频率中至少一项不同。
根据本发明的另一个具体方面， 所述连通不同电极线的同一触控激励源不同输 出端或不同触控激励源输出端中， 至少有一个输出端连通触控电路的接地端。
根据本发明的另一个具体方面， 所述触控电路与应用产品的主机电路和显示系 统之间， 或触控电路电源与应用产品的主机电路电源和显示系统电源之间， 或触控 电路的触控激励源与应用产品的主机电路电源和显示系统电源之间， 设置有信号隔 离器件； 所述信号隔离器件是触控信号的高阻器件。
根据本发明的另一个具体方面， 所述触控基板上的触控电极是一组不交的电极 线， 触控电路通过比较不同电极线上触控信号变化的大小确定被触电极， 以流经被 触电极上触控信号变化的大小定位触摸点在被触电极上的位置。
根据本发明的另一个具体方面， 所述触控基板上的触控电极是一组不交的电极 线， 不同电极线在不同方向具有引出端， 取不同方向引出端的电极线为检测电极； 触控电路通过比较不同触控电极线上触控信号变化的大小确定被触电极， 通过比较 不同方向引出端的检测电极上触控信号变化的大小定位触摸点在被触电极上的位 置。
根据本发明的另一个具体方面， 所述不交的电极线是折线。
本发明与现有技术对比的有益效果是：
本发明的技术解决方案， 在触控屏或具有触控屏的应用产品上建立了触控信号 的回流电极， 在触控电路和触控电极间形成触控信号的闭合回路， 再将触控系统与 其他系统隔离开来， 降低了不同系统间信号的串扰， 防止了其他信号特别是显示信 号对触控探测的影响。
本发明的技术解决方案， 触控电路和触控屏上的触控电极间形成了触控信号的 闭合回路， 触控物改变不同电极线间的耦合电容， 让操作者带上手套也可以顺利工 作， 让非金属笔和金属笔都可以操作触控屏。 触控屏上的触控信号回路， 还减少了 触控信号在触控屏各条触控电极之间的串扰流动， 提高对被触电极判断的准确性， 实现空间数字化的电容式触控屏。
本发明的技术解决方案， 在应用产品外壳体上设置触控回流电极， 在触控电路、 触控屏上的触控电极和外壳体触控回流电极间建立触控信号的闭合回路， 避免了水 滴对触控电路判断触控信号产生的影响。 附图说明
图 1是本发明具体实施方式一和方式二的电气连接示意图；
图 2是本发明具体实施方式三的电气连接示意图；
图 3是本发明具体实施方式四的电气连接示意图； 图 4是本发明具体实施方式五的电气连接示意图；
图 5是本发明具体实施方式六的电气连接示意图；
图 6是本发明具体实施方式七的电气连接示意图；
图 7是本发明具体实施方式八的电气连接示意图；
图 8是本发明具体实施方式九的电气连接示意图。 具体实施方式
以下各附图中的连接线并不只代表单线连接， 也代表多线的连接关系。 具体实施方式一
如图 la所示的电容式触控屏 100， 包括触控板 110和触控电路 140等。 触控板 110 上设置有两组以绝缘层相间隔的相互正交的行电极组 120(有行电极线 121、 122、 ...、 12i-2 12i-l 12i、 12i+l、 12i+2 ...、 12m)和列电极组 130(有列电极线 131、 132、 ...、 13j-2、 13j-l、 13j、 13j+l、 13j+2、 ...、 13n)。 触控电路 140具有触 控激励源 150 和触控信号检测电路 160。 触控激励源 150 的触控信号频率选择在 ΙΟΟΚΗζ或以上。触控信号检测电路 160是由信号检测通道 161、数据采样通道 162、 数据处理和时序控制器 163组成； 信号检测通道 161具有触控信号采样元件 1611、 缓冲器 1612、 差分放大电路 1613等； 数据采样通道 162具有模数转换电路； 数据 处理和时序控制电路 163 是具有数据运算能力、 数据输出输入接口的中央处理器 (CPU MCU), 中央处理器具有控制软件、 数据处理软件。
触控电路 140的触控信号检测电路 160选择行电极组 120中的电极线 12i为检 测电极， 让电极线 12i通过触控信号采样元件 1611与触控激励源 150的输出端 151 连通， 触控信号检测电路 160的其他电路连接触控信号采样元件 1611的两端； 让行 电极组 120中的电极线 12i-l和 12i+l都与触控激励源 150的输出端 152连通，作为 触控信号的回流电极； 再通过电极线 12i与电极线 12i-l间的耦合电容 Cw、 与电极 线 12i+l间的耦合电容 C1+1，形成触控信号的闭合触控回路；让行电极组 120中所有 其余的行电极线和列电极组 130的所有列电极线也都与触控激励源 150的输出端 151 连通。从触控激励源输出端 151流出的触控信号， 经触控信号采样元件 1611流入行 电极线 12i上， 经电极线 12i与电极线 12i-l间的耦合电容 d_r流入电极线 12i-l、 经 电极线 12i与电极线 12i+l 间的耦合电容 C1+r流入电极线 12i+l， 再从电极线 12i-l 和 12i+l流回触控激励源输出端 152，触控信号在闭合的触控回路上的流动，等效电 路如图 lb所示。
当作为触控物 170的人的手指靠近或接触行电极线 12i时， 由于手指具有一定 的宽度， 同时也就触及到行电极线 12i-l和行电极线 12i+l， 人体的介电系数远大于 空气的介电系数， 使得耦合电容 和 C1+1的容值增大容抗减小， 触控回路上触控 信号的电流相应变大，等效电路如图 lc所示。当手指靠近或接触非 12i、12i-l和 12i+l 的其他行电极线的位置时， 虽然也会使得行电极线之间、 行电极线和列电极线之间 的耦合电容都发生改变， 但由于在所触位置上， 各电极所连通触控激励源 150的输 出端都是同一输出端 151， 流经触控信号采样元件 1611上触控信号电流的变化就非 常小。
触控电路 140以扫描方式， 顺序地让触控屏 100各电极线通过触控信号采样元 件 1611连通触控激励源 150的输出端 151， 同时使其两侧相邻的触控电极线连通触 控激励源 150的输出端 152， 让所有其余的电极线也连通触控激励源 150的输出端 151， 同时触控信号检测电路 160检测流经触控信号采样元件 1611上触控信号电流 的变化， 找出触控信号电流变化最大的并超过某阈值的触控电极线为被触电极线； 以行电极组 120中的被触电极线和列电极组 130中的被触电极线的交叉位置为手指 的触控位置。
判断被触电极线的条件， 也可只以检测到流经的触控信号变化量超过某设定阈 值的电极线为被触电极线， 让电容式触控屏 loo允许同时多点触控。
由于触控信号是在触控电路 140与触控板 110上的不同触控电极线间所形成的 闭合回路上流动， 触控物 170以介电系数与空气介电系数不同的非金属物体靠近或 接触触控屏 100时，也是可以改变相邻触控电极线间的耦合电容 ^^和 ，造成触 控回路上触控信号电流的变化，让非金属触控物 (如通常的触控笔)也可以用于操作电 容式触控屏 100; 触控物 170以金属物体靠近或接触触控屏 100时， 金属物体改变 了相邻触控电极线间的有效耦合距离， 从而改变了触控电极线间的耦合电容 Cw和 C1+1， 造成回路上触控信号电流的变化， 让金属触控物 (如金属触控笔；)也可以用于操 作电容式触控屏 100。
也可以在检测时段中， 让行电极组 120中的行电极线 12i通过触控信号采样元 件 1611与触控激励源 150的输出端 151连通，触控信号检测电路 160的其他电路连 接触控信号采样元件 1611 的两端； 让行电极组 120中所有其余的行电极线 (包括行 电极线 12i-l和 12i+l)都与触控激励源 150的输出端 152连通，作为触控信号的回流 电极；让列电极组 130的所有列电极线都直接与触控激励源 150的输出端 151连通。 触控物 170靠近或接触行电极线 12i时， 同样会使得耦合电容 和 C1+1的改变，通 过检测流经触控信号采样元件 1611上触控信号电流的变化， 可找出被触电极线。
也可以在检测时段中， 让行电极组 120中的行电极线 12i通过触控信号采样元 件 1611与触控激励源 150的输出端 151连通，触控信号检测电路 160的其他电路连 接触控信号采样元件 1611 的两端； 让行电极组 120中所有其余的行电极线 (包括行 电极线 12i-l和 12i+l)都与触控激励源 150的输出端 152连通；让列电极组 130的所 有列电极线也都与触控激励源 150的输出端 152连通。 触控物 170靠近或接触行电 极线 12i时， 同样会使得耦合电容 和 C1+1的改变，通过检测流经触控信号采样元 件 1611上触控信号电流的变化， 可找出被触电极线。
也可以在检测时段中， 行电极线 12i通过触控信号采样元件 1611与触控激励源 150的输出端 151连通， 触控信号检测电路 160的其他电路连接触控信号采样元件 1611的两端； 让行电极组 120中所有其余的行电极线也与触控激励源 150的输出端 151连通， 让列电极组 130的所有列电极线都与触控激励源 150的输出端 152连通， 作为触控信号的回流电极。 触控物 170靠近或接触行电极线 12i时， 会使得行电极 线 12i和列电极组 130之间的耦合电容都发生改变， 通过检测流经触控信号采样元 件 1611上触控信号电流的变化， 可找出被触电极线。 也可以在检测时段中， 行电极线 12i通过触控信号采样元件 1611与触控激励源 150的输出端 151连通， 触控信号检测电路 160的其他电路连接触控信号采样元件 1611的两端； 让行电极组 120中所有其余的行电极线也与触控激励源 150的输出端 151连通， 让列电极组 130中的电极线 131、 132、 ...、 13j-l也都与触控激励源 150 的输出端 151连通； 让列电极组 130中的电极线 13j、 ...、 13η都与触控激励源 150 的输出端 152连通， 作为触控信号的回流电极。触控物 170靠近或接触行电极线 12i 位于列电极线 131到 13j-l之间的部分时， 虽然会使得电极线 12i与电极线 12i-l、 121+1之间的耦合电容都发生改变， 也会使行电极线 12i和列电极组 130之间的耦合 电容都发生改变， 但由于在所触位置上， 各电极所连通触控激励源 150的输出端都 是同一输出端 151， 流经触控信号采样元件 1611上触控信号电流的变化非常小； 触 控物 170靠近或接触行电极线 12i位于列电极线 13j到 13η之间的部分时，会使得行 电极线 12i和列电极组 130之间的耦合电容都发生改变， 在所触位置上， 行电极线 12i与列电极线 13j、 ...、 13η所连通触控激励源 150的输出端是不相同的， 流经触 控信号采样元件 1611上触控信号电流的变化较大；通过检测流经触控信号采样元件 1611上触控信号电流的变化， 可找出被触电极线。 具体实施方式二
如图 la所示的电容式触控屏 100， 包括触控板 110和触控电路 140等。 触控板 110 上设置有两组以绝缘层相间隔的相互正交的行电极组 120(有行电极线 121、 122、 ...、 12i-2 12i-l 12i、 12i+l、 12i+2 ...、 12m)和列电极组 130(有列电极线 131、 132、 ...、 13j-2、 13j-l、 13j、 13j+l、 13j+2、 ...、 13n)。 触控电路 140具有触 控激励源 150 和触控信号检测电路 160。 触控激励源 150 的触控信号频率选择在 ΙΟΟΚΗζ或以上。触控信号检测电路 160是由信号检测通道 161、数据采样通道 162、 数据处理和时序控制器 163组成； 信号检测通道 161具有触控信号采样元件 1611、 缓冲器 1612、 差分放大电路 1613等； 数据采样通道 162具有模数转换电路； 数据 处理和时序控制电路 163 是具有数据运算能力、 数据输出输入接口的中央处理器 (CPU MCU), 中央处理器具有控制软件、 数据处理软件。
触控电路 140的触控信号检测电路 160，让行电极组 120中的电极线 12i与触控 激励源 150的输出端 152连通， 作为触控信号的回流电极； 选择行电极组 120中的 电极线 12i-l和 12i+l为检测电极， 让电极线 12i-l和 12i+l都通过触控信号采样元 件 1611与触控激励源 150的输出端 151连通，触控信号检测电路 160的其他电路连 接触控信号采样元件 1611的两端； 再通过电极线 12i-l与电极线 12i间的耦合电容 电极线 12i+l与电极线 12i间的耦合电容 C1+1， 形成触控信号的闭合触控回路； 让行电极组 120中所有其余的行电极线和列电极组 130的所有列电极线都直接与触 控激励源 150的输出端 152连通。从触控激励源输出端 151经触控信号采样元件 1611 流入行电极线 12i-l和 12i+l的触控信号， 一部分经电极线 12i-l与电极线 12i间的 耦合电容 d_r流入电极线 12i、 经电极线 12i+l与电极线 12i间的耦合电容 C1+1也流 入电极线 12i，再从电极线 12i流回触控激励源输出端 152;另一部分经行电极线 12i-l 和 12i+l 与列电极线间的耦合电容流入列电极线， 再从列电极线流回触控激励源输 出端 152， 触控信号在闭合的触控回路上的流动， 等效电路如图 Id所示。
当作为触控物 170的人的手指靠近或接触行电极线 12i时， 由于手指具有一定 的宽度， 同时也就触及到行电极线 12i-l和行电极线 12i+l， 人体的介电系数远大于 空气的介电系数， 使得耦合电容 和 C1+1的容值增大容抗减小， 触控回路上触控 信号的电流相应变大， 等效电路如图 le所示。
触控电路 140以扫描方式， 顺序地让触控屏 100各电极线连通触控激励源 150 的输出端 151， 同时使其两侧相邻的触控电极线通过触控信号采样元件 1611连通触 控激励源 150的输出端 152， 让所有其余的电极线也连通触控激励源 150的输出端 152， 同时触控信号检测电路 160检测流经触控信号采样元件 1611上触控信号电流 的变化， 找出触控信号电流变化最大的并超过某阈值的触控电极线为被触电极线； 以行电极组 120中的被触电极线和列电极组 130中的被触电极线的交叉位置为手指 的触控位置。
判断被触电极线的条件， 也可只以检测到流经的触控信号变化量超过某设定阈 值的电极线为被触电极线， 让电容式触控屏 100允许同时多点触控。
由于触控信号是在触控电路 140与触控板 110上的不同触控电极线间所形成的 闭合回路上流动， 触控物 170以介电系数与空气介电系数不同的非金属物体靠近或 接触触控屏 100时，也是可以改变相邻触控电极线间的耦合电容 ^^和 ，造成触 控回路上触控信号电流的变化，让非金属触控物 (如通常的触控笔)也可以用于操作电 容式触控屏 100; 触控物 170以金属物体靠近或接触触控屏 100时， 金属物体改变 了相邻触控电极线间的有效耦合距离， 从而改变了触控电极线间的耦合电容 Cw和 C1+1， 造成回路上触控信号电流的变化， 让金属触控物 (如金属触控笔；)也可以用于操 作电容式触控屏 100。
也可以在检测时段中， 让行电极组 120中的行电极线 12i-2、 12i和 12i+2都与 触控激励源 150 的输出端 151 连通， 作为触控信号的回流电极； 让行电极线 12i-l 和 12i+l都通过触控信号采样元件 1611与触控激励源 150的输出端 152连通， 触控 信号检测电路 160的其他电路连接触控信号采样元件 1611的两端； 让行电极组 120 中所有其余的行电极线和让列电极组 130的所有列电极线也都与触控激励源 150的 输出端 152连通。 触控物 170靠近或接触行电极线 12i时， 同样会使得电极线 12i-2 与电极线 12i-l之间的耦合电容、 电极线 12i-l与电极线 12i之间的耦合电容、 电极 线 12i与电极线 12i+l之间的耦合电容、 电极线 12i+l与电极线 12i+2之间的耦合电 容都发生改变， 通过检测流经触控信号采样元件 1611上触控信号电流的变化， 可找 出被触电极线。 具体实施方式三
如图 2所示的电容式触控屏的应用产品 200， 包括透明触控板 210、 触控电路
240、显示系统和主机电路 280等。触控板 210上设置有两组以绝缘层相间隔的相互 正交的行电极组 220(有行电极线 221、 222、 ...、 22Ϊ-Κ 22 22Ϊ+Κ ...、 22m)和列 电极组 230(有列电极线 231、 232、 ...、 23j-l、 23j、 23j+l、 ...、 23η；)。 触控电路 240 具有触控激励源 250和触控信号检测电路 260。 触控激励源 250的输出端口为 251 和 252， 触控激励源 250的触控信号频率选择在 ΙΟΟΚΗζ; 触控信号检测电路 260是 由信号检测通道 261、 数据采样通道 262、 数据处理和时序控制器 263组成； 信号检 测通道 261具有触控信号采样元件 2611、 缓冲器 2612和 2613、 信号滤波器 2614、 差分放大电路 2615等， 其中信号滤波器 2614具有阻止频率非 ΙΟΟΚΗζ信号通过的 能力； 数据采样通道 262具有模数转换电路； 数据处理和时序控制电路 263是具有 数据运算能力、 数据输出输入接口的中央处理器 (CPU、 MCU), 中央处理器具有控 制软件、数据处理软件。显示系统具有显示屏 271、显示驱动电路 272、背光源 273、 背光源驱动电路 274和显示系统电源 275等。 透明触控板 210紧靠在显示屏 271的 正面上， 背光源 273也紧靠显示屏 271的背面。主机电路 280具有主机电源 281等。
触控电路 240的触控信号检测电路 260选择行电极组 220中的电极线 22i为检 测电极， 让电极线 22i通过触控信号采样元件 2611与触控激励源 250的输出端 251 连通，触控信号检测电路 260的缓冲器 2612和 2613连接触控信号采样元件 2611的 两端， 信号滤波器 2614连接缓冲器 2612和 2613、 差分放大电路 2615连接信号滤 波器 2614; 让行电极组 220中的电极线 22i-l和 22i+l都与触控激励源 250的输出 端 252连通， 作为触控信号的回流电极； 再通过电极线 22i与电极线 22i-l间的耦合 电容 Cw、 与电极线 22i+l间的耦合电容 C1+1， 形成触控信号的闭合触控回路； 让行 电极组 220中所有其余的行电极线和列电极组 230的所有列电极线都直接与触控激 励源 250的输出端 251连通。 主机电源 281连接显示系统的显示系统电源 275， 显 示系统电源 275连接显示驱动电路 272和背光源驱动电路 274， 显示驱动电路 272 和背光源驱动电路 274分别连接显示屏 271和背光源 273。 触控电路 240触控激励 源 250的电源端和触控信号检测电路 260的电源端通过两个电感元件 241和 242连 接主机电源 281 ; 触控信号检测电路 260的数据处理和时序控制器 263连接数据采 样通道 262， 数据采样通道 262连接信号检测通道 261 ; 信号检测通道 261的触控信 号采样元件 2611连接在触控激励源 250和触控板 210的电极线之间，信号检测通道 261 内差分放大电路 2615通过信号滤波器 2613连接缓冲器 2612和 2613、 缓冲器 2612连接在触控信号采样元件 2611连接触控板 210电极线的端点， 缓冲器 2613连 接在触控信号采样元件 2611 连接触控激励源 250 的端点； 数据处理和时序控制器 263同时连接主机电路 280。
当人的手指 290靠近或接触行电极线 22i时， 由于手指 290具有一定的宽度， 同时也就触及到行电极线 22i-l和行电极线 22i+l， 人体的介电系数远大于空气的介 电系数， 使得耦合电容 和 c1+1的容值增大容抗减小， 触控回路上触控信号的电 流相应变大。通过检测流经触控信号采样元件 2611上触控信号电流的变化， 可找出 被触电极线。
由于触控板 210是紧靠在显示屏 271上， 触控板 210上的各电极线也与显示屏 271的电极间存在耦合电容 CTD。触控激励源 250输出到触控板 210电极线上的触控 信号， 具有通过耦合电容 CTD流入显示屏 271 电极、 再流入显示系统电源 275、 再 流入主机电源 281、 再从主机电源 281流回触控激励源 250的倾向； 但由于在触控 电路 240与主机电源 281的连接线上设置有电感元件 241和 242， 使得较高频的触 控信号不能顺利通过； 触控信号在触控激励源 250、触控板 210电极线和显示屏 271 间不能获得通畅的回路， 就防止了触控信号在触控系统和显示系统间串流， 避免触 控屏与显示屏间的耦合电容对触控探测产生干扰； 同时， 信号检测通道 261 内的信 号滤波器 2614也阻止了其他非 ΙΟΟΚΗζ干扰信号的通过，进一步降低了干扰信号对 触控探测的影响。
上述信号检测通道 261的触控信号采样元件 2611连接在触控激励源 250和触控 板 210的电极线之间，信号检测通道 261内差分放大电路 2615通过信号滤波器 2614 连接缓冲器 2612和 2613、 缓冲器 2612连接在触控信号采样元件 2611连接触控板 210电极线的端点，缓冲器 2613连接在触控信号采样元件 2611连接触控激励源 250 的端点。触控信号采样元件 2611连接触控激励源 250的端点是信号检测通道 261的 信号测量参考点，而这个信号测量参考点也可以选择在其他位置，也就是缓冲器 2613 可连接如触控电路 240的接地端、 或主机电路 280的接地端、 或专设的比较电路中 的某一端， 以获得更好的测量效果。 具体实施方式四
如图 3所示的电容式触控屏的应用产品 300， 包括透明触控板 310、 触控电路
340、显示系统和主机电路 380等。触控板 310上设置有两组以绝缘层相间隔的相互 正交的行电极组 320(有行电极线 321、 322、 ...、 32Ϊ-Κ 32i、 32Ϊ+Κ ...、 32m)和列 电极组 330(有列电极线 331、 332、 ...、 33j-l、 33j、 33j+l、 ...、 33η；)。 触控电路 340 具有触控激励源 350和触控信号检测电路 360。 触控激励源 350的输出端口为 351 和 352， 触控激励源 350的触控信号频率选择在 400ΚΗζ; 触控激励源 350的输出端 口具有对 400ΚΗζ频率信号的选通滤波器 353 ;触控信号检测电路 360是由信号检测 通道 361、 数据采样通道 362、 数据处理和时序控制器 363组成； 信号检测通道 361 具有触控信号采样元件 3611、 缓冲器 3612和 3613、 差分放大电路 3614等； 数据采 样通道 362具有模数转换电路；数据处理和时序控制电路 363是具有数据运算能力、 数据输出输入接口的中央处理器 (CPU、 MCU), 中央处理器具有控制软件、 数据处 理软件。 显示系统具有显示屏 371、 显示驱动电路 372、 背光源 373、 背光源驱动电 路 374和显示系统电源 375等。 透明触控板 310紧靠在显示屏 371上， 背光源 373 也紧靠显示屏 371的背面。 主机电路 380具有主机电源 381等。
触控电路 340的触控信号检测电路 360选择行电极组 320中的电极线 32i为检 测电极， 让电极线 32i通过触控信号采样元件 3611与触控激励源 350的输出端 351 连通， 触控信号检测电路 360的其他电路连接触控信号采样元件 3611的两端； 让行 电极组 320中的电极线 32i-l和 32i+l都经过选通滤波器 353与触控激励源 350的输 出端 352连通， 作为触控信号的回流电极； 再通过电极线 32i与电极线 32i-l间的耦 合电容 Cw、 与电极线 32i+l间的耦合电容 C1+1， 形成触控信号的闭合触控回路； 让 行电极组 320中所有其余的行电极线和列电极组 330的所有列电极线都直接与触控 激励源 350的输出端 351连通。显示系统的显示系统电源 375通过两个电感元件 376 和 377连接主机电源 381， 显示系统电源 375连接显示驱动电路 372和背光源驱动 电路 374， 显示驱动电路 372和背光源驱动电路 374分别连接显示屏 371和背光源 373。主机电源 381连接触控电路 340触控激励源 350的电源端和触控信号检测电路 360的电源端； 触控信号检测电路 360的数据处理和时序控制器 363连接数据采样 通道 362， 数据采样通道 362连接信号检测通道 361 ; 信号检测通道 361内差分放大 电路 3614连接缓冲器 3612和 3613，缓冲器 3612和 3613连接触控信号采样元件 3611 的两端，信号检测通道 361的触控信号采样元件 3611连接在触控激励源 350和触控 板 310的电极线之间； 数据处理和时序控制器 363同时连接主机电路 380。
当人的手指 390靠近或接触行电极线 32i时， 由于手指 390具有一定的宽度， 同时也就触及到行电极线 32i-l和行电极线 32i+l， 人体的介电系数远大于空气的介 电系数， 使得耦合电容 和 C1+1的容值增大容抗减小， 触控回路上触控信号的电 流相应变大。通过检测流经触控信号采样元件 3611上触控信号电流的变化， 可找出 被触电极线。
由于触控板 310是紧靠在显示屏 371上， 触控板 310上的各电极线也与显示屏 371的电极间存在耦合电容 CTD。触控激励源 350输出到触控板 310电极线上的触控 信号， 具有通过耦合电容 CTD流入显示屏 371 电极、 再流入显示系统电源 375、 再 流入主机电源 381、 再从主机电源 381流回触控激励源 350的倾向； 但由于在显示 系统电源 375与主机电源 381的连接线上设置有电感元件 376和 377， 使得较高频 的触控信号不能顺利通过； 触控信号在触控激励源 350、 触控板 310 电极线和显示 屏 371 间不能获得通畅的回路， 就防止了触控信号在触控系统和显示系统间串流， 避免触控屏与显示屏间的耦合电容对触控探测产生干扰； 同时， 触控回路内的选通 滤波器 353也阻止了其他非 400KHZ的干扰信号通过， 进一步降低了干扰信号对触 控探测的影响。 具体实施方式五
如图 4所示的电容式触控屏的手持式应用产品 400， 包括透明触控板 410、触控 电路 440、 显示系统、 主机电路 480和外壳体 490等。 触控板 410上设置有两组以 绝缘层相间隔的相互正交的行电极组 420(有行电极线 421、 422、 ...、 42Ϊ-Κ 42i、 42i+l、 ...、 42m)和列电极组 430(有列电极线 431、 432、 ...、 43j-l、 43j、 43j+l、 ...、 43η)。 触控电路 440具有触控激励源 450和触控信号检测电路 460。 触控激励源 450 的触控信号频率选择在 ΙΟΟΚΗζ或以上； 触控信号检测电路 460是由信号检测通道 461、 数据采样通道 462、 数据处理和时序控制器 463组成； 信号检测通道 461具有 触控信号采样元件 4611、 缓冲器 4612和 4613、 差分放大电路 4614等； 数据采样通 道 462具有模数转换电路； 数据处理和时序控制电路 463是具有数据运算能力、 数 据输出输入接口的中央处理器 (CPU、 MCU), 中央处理器具有控制软件、 数据处理 软件。 显示系统具有显示屏 471、 显示驱动电路 472、 背光源 473、 背光源驱动电路 474和显示系统电源 475等。 透明触控板 410紧靠在显示屏 471的正面上， 背光源 473也紧靠显示屏 471的背面。 主机电路 480具有主机电源 481等。 外壳体 490上 设置有电极 491。
主机电源 481连接显示系统 470的显示系统电源 475， 显示系统电源 475连接 显示驱动电路 472和背光源驱动电路 474，显示驱动电路 472和背光源驱动电路 474 分别连接显示屏 471和背光源 473。 触控电路 440触控激励源 450的电源端和触控 信号检测电路 460的电源端通过两个电感元件 441和 442连接主机电源 481。 触控 信号检测电路 460的数据处理和时序控制器 463连接数据采样通道 462， 数据采样 通道 462连接信号检测通道 461 ; 信号检测通道 461内的差分放大电路 4614连接缓 冲器 4612和 4613， 缓冲器 4612和 4613连接触控信号采样元件 4611的两端， 信号 检测通道 461的触控信号采样元件 4611连接在触控激励源 450和触控板 410的电极 线之间； 数据处理和时序控制器 463同时连接主机电路 480。
触控电路 440的触控信号检测电路 460选择行电极组 420中的电极线 42i为检 测电极， 让电极线 42i通过触控信号采样元件 4611与触控激励源 450的输出端 451 连通， 触控信号检测电路 460的其他电路连接触控信号采样元件 4611的两端； 让行 电极组 420中所有其余的行电极线和列电极组 430的所有列电极线都直接与触控激 励源 450的输出端 451连通； 以外壳体 490上的电极 491作为触控信号的回流电极， 让电极 491与触控激励源 450的输出端 452连通；当人的手指 4100靠近或接触行电 极线 42i时， 手指 4100与行电极线 42i间产生一个耦合电容 d， 触控激励源 450输 出到行电极线 42i上的触控激励信号就会通过此耦合电容 G流入手指， 再通过持握 产品的手掌流入产品外壳体上的回流电极 491， 再从回流电极 491流回到触控激励 源 450; 由触控激励源、 触控板电极线、 手指与电极线间的耦合电容、 外壳体上的 回流电极组成触控回路。通过检测流经触控信号采样元件 4611上触控信号电流的变 化， 可找出被触电极线。
由于触控板 410是紧靠在显示屏 471上， 触控板 410上的各电极线也与显示屏 471的电极间存在耦合电容 CTD。触控激励源 450输出到触控板 410电极线上的触控 信号， 具有通过耦合电容 CTD流入显示屏 471 电极、 再流入显示系统电源 475、 再 流入主机电源 481、 再从主机电源 481流回触控激励源 450的倾向； 但由于在触控 电路 440与主机电源 481的连接线上设置有电感元件 441和 442， 使得较高频的触 控信号不能顺利通过； 触控信号在触控激励源 450、触控板 410电极线和显示屏 471 间不能获得通畅的回路， 就防止了触控信号在触控系统和显示系统间串流， 避免触 控屏与显示屏间的耦合电容对触控探测产生干扰。
当触控板 410的表面落有水滴时， 触控板 410表面的水滴并不会造成触控板电 极线与产品外壳体 490上电极 491间的连接， 就无法形成触控板电极线、 触控板表 面水滴、 外壳体电极、 触控激励源的触控信号回路。 只有持握应用产品的操作者的 手指触控触控板时， 才会形成触控激励源、 触控板电极线、 手指与电极线间的耦合 电容、 外壳体上的回流电极组成的触控信号回路。 触控板 410表面的水滴也就不会 影响到触控电路对触控信号的判断。 具体实施方式六
如图 5所示的触控式平板显示器 500， 包括显示屏 510、 显示驱动电路 540、 触 控电路 550和显示 /触控信号选通电路 560等。 显示屏 510上设置有两组以绝缘层相 间隔的相互正交的行电极组 520(有行电极线 521、 522、 ...、 52Ϊ-Κ 52i、 52i+l、 ...、 52m)和列电极组 530(有列电极线 531、 532、 ...、 53j-l、 53j、 53j+l、 ...、 53η；)。 触 控电路 550具有触控激励源 570和触控信号检测电路 580。 触控信号检测电路 580 是由信号检测通道 581、 数据采样通道 582、 数据处理和时序控制器 583组成； 信号 检测通道 581具有触控信号采样元件 5811、缓冲器 5812和 5813、差分放大电路 5814 等； 数据采样通道 582具有模数转换电路； 数据处理和时序控制电路 583是具有数 据运算能力、 数据输出输入接口的中央处理器 (CPU、 MCU), 中央处理器具有控制 软件、 数据处理软件。 显示驱动电路 540和触控电路 550通过显示 /触控信号选通电 路 560连接到显示屏 510; 显示 /触控信号选通电路 560或让显示驱动电路 540与显 示屏 510连通、 或让触控电路 550与显示屏 510连通。
在显示时段， 显示 /触控信号选通电路 560让显示驱动电路 540与显示屏 510连 通， 向显示屏 510传输显示驱动信号， 显示屏 510处于显示状态。
在检测时段， 显示 /触控信号选通电路 560让触控电路 550与显示屏 510连通， 向显示屏 510传输触控信号， 显示屏 510处于触控探测状态。 在检测时段中的某一 时刻， 触控电路 550的触控信号检测电路 580选择行电极组 520中的电极线 52i为 检测电极，让电极线 52i通过触控信号采样元件 5811与触控激励源 570的输出端 571 连通， 触控信号检测电路 580的其他电路连接触控信号采样元件 5811的两端； 让行 电极组 520中的电极线 52i-l和 52i+l都与触控激励源 570的输出端 572连通，作为 触控信号的回流电极； 再通过电极线 52i与电极线 52i-l间的耦合电容 Cw、 与电极 线 52i+l间的耦合电容 C1+1，形成触控信号的闭合触控回路；让行电极组 520中所有 其余的行电极线和列电极组 530的所有列电极线也都与触控激励源 570的输出端 571 连通。从触控激励源输出端 571流出的触控信号， 经触控信号采样元件 5811流入行 电极线 52i上， 经电极线 52i与电极线 52i-l间的耦合电容 d_r流入电极线 52i-l、 经 电极线 52i与电极线 52i+l 间的耦合电容 C1+r流入电极线 52i+l， 再从电极线 52i-l 和 52i+l流回触控激励源输出端 572， 触控信号在闭合的触控回路上的流动。
当作为触控物 590的人的手指靠近或接触行电极线 52i时， 由于手指具有一定 的宽度， 同时也就触及到行电极线 52i-l和行电极线 52i+l， 人体的介电系数远大于 空气的介电系数， 使得耦合电容 和 C1+1的容值增大容抗减小， 触控回路上触控 信号的电流相应变大。 当手指靠近或接触非 52i、 52Ϊ-1和 52i+l 的其他行电极线的 位置时， 虽然也会使得行电极线之间、 行电极线和列电极线之间的耦合电容都发生 改变， 但由于在所触位置上， 各电极所连通触控激励源 570的输出端都是同一输出 端 571， 流经触控信号采样元件 5811上触控信号电流的变化就非常小。
触控电路 550以扫描方式， 顺序地让显示屏 510各电极线通过触控信号采样元 件 5811连通触控激励源 570的输出端 571， 同时使其两侧相邻的触控电极线连通触 控激励源 570的输出端 572， 让所有其余的电极线也连通触控激励源 570的输出端 571， 同时触控信号检测电路 580检测流经触控信号采样元件 5811上触控信号电流 的变化， 找出触控信号电流变化最大的并超过某阈值的触控电极线为被触电极线； 以行电极组 520中的触电极线和列电极组 530中的被触电极线的交叉位置为手指的 触控位置。
判断被触电极线的条件， 也可只以检测到流经的触控信号变化量超过某设定阈 值的电极线为被触电极线， 让触控式平板显示器 500允许同时多点触控。
由于触控信号是在触控电路 550与显示屏 510上的不同触控电极线间所形成的 闭合回路上流动， 触控物 590以介电系数与空气介电系数不同的非金属物体靠近或 接触显示屏 510时，也是可以改变相邻触控电极线间的耦合电容 ^^和^+，造成触 控回路上触控信号电流的变化，让非金属触控物 (如通常的触控笔)也可以用于操作触 控式平板显示器 500; 触控物 580以金属物体靠近或接触显示屏 510时， 金属物体 改变了相邻触控电极线间的有效耦合距离，从而改变了触控电极线间的耦合电容 Cw 和。1+1， 造成回路上触控信号电流的变化， 让金属触控物 (如金属触控笔；)也可以用于 操作触控式平板显示器 500。 具体实施方式七
如图 6所示为安装有触控式平板显示器的手持式应用产品 600，包括显示屏 610、 显示驱动电路 640、触控电路 650、 显示 /触控信号选通电路 660、 主机电路 670和外 壳体 680等。显示屏 610上设置有两组以绝缘层相间隔的相互正交的行电极组 620(有 行电极线 621、 622、 ...、 62Ϊ-Κ 62i、 62i+l、 ...、 62m)和列电极组 630(有列电极线 631、 632、 ...、 63j-l、 63j、 63j+l、 ...、 63η；)。 触控电路 650 具有触控激励源 651 和触控信号检测电路 652， 触控信号检测电路 652具有触控信号采样元件 6521等。 主机电路 670具有主机电源 671等。 外壳体 680上设置有电极 681。 触控电路 650 触控激励源 651 的电源端和触控信号检测电路 652的电源端通过两个电感元件 653 和 654连接主机电源 671。 显示驱动电路 640和触控电路 650通过显示 /触控信号选 通电路 660连接到显示屏 610; 显示 /触控信号选通电路 660或让显示驱动电路 640 与显示屏 610连通、 或让触控电路 650与显示屏 610连通。
在显示时段， 显示 /触控信号选通电路 660让显示驱动电路 640与显示屏 610连 通， 向显示屏 610传输显示驱动信号， 显示屏 610处于显示状态。
在检测时段， 显示 /触控信号选通电路 660让触控电路 650与显示屏 610连通， 向显示屏 610传输触控信号， 显示屏 610处于触控探测状态。 在检测时段中的某一 时刻， 触控电路 640的触控信号检测电路 652选择行电极组 620中的电极线 62i为 检测电极，让电极线 62i通过触控信号采样元件 6521与触控激励源 651的输出端 6511 连通， 触控信号检测电路 652的其他电路连接触控信号采样元件 6521的两端； 让行 电极组 620中所有其余的行电极线和列电极组 630的所有列电极线也都与触控激励 源 651的输出端 6511连通； 以外壳体 680上的电极 681作为触控信号的回流电极， 让电极 681与触控激励源 651的输出端 6512连通；当人的手指 690靠近或接触行电 极线 62i时，手指 690与行电极线 62i间产生一个耦合电容 d，触控激励源 651输出 到行电极线 62i上的触控激励信号就会通过此耦合电容 G流入手指， 再通过持握产 品的手掌流入产品外壳体上的回流电极 681， 再从回流电极 681流回到触控激励源 651； 由触控激励源、 触控板电极线、 手指与电极线间的耦合电容、 外壳体上的回流 电极组成触控回路。 通过检测流经触控信号采样元件 6521上触控信号电流的变化， 可找出被触电极线。
当显示屏 610的表面落有水滴时， 显示屏 610表面的水滴并不会造成显示屏电 极线与产品外壳体 680上电极 681间的连接， 就无法形成显示屏电极线、 显示屏表 面水滴、 外壳体电极、 触控激励源的触控信号回路。 只有持握应用产品的操作者的 手指触控触控板时， 才会形成触控激励源、 触控板电极线、 手指与电极线间的耦合 电容、 外壳体上的回流电极组成的触控信号回路。 显示屏 610表面的水滴也就不会 影响到触控电路对触控信号的判断。 具体实施方式八
如图 7所示的电容式触控屏的应用产品 700， 包括触控电极组 710、 触控电路 720、 显示系统和主机电路 760等。 显示系统具有显示屏 751、 显示驱动电路 752、 背光源 753、 背光源驱动电路 754和显示系统电源 755等， 背光源 753紧靠在显示 屏 751的背面。 主机电路 760具有主机电源 761等。 在显示屏 751上基板的上表面 上设置有一组相互不相交的折线状电极组 710(有折线状的电极线 711、712、...、71i-l、 71i、 71i+l、 ...、 71m), 各电极线的引出端都是位于电极组 710 的相同方向， 电极 线以具有一定电阻值的 ITO透明材料制成。 触控电路 720具有触控激励源 730和触 控信号检测电路 740。触控激励源 730的输出端口为 731和 732， 触控激励源 730的 触控信号频率选择在 400KHz， 触控激励源 730的输出端口 732处具有对 400KHz 频率信号的选通滤波器 733 ; 触控信号检测电路 740是由信号检测通道 741、数据采 样通道 742、 数据处理和时序控制器 743组成； 信号检测通道 741具有触控信号采 样元件 7411、 缓冲器 7412和 7413、 信号滤波器 7414、 差分放大电路 7415等； 数 据采样通道 742具有模数转换电路； 数据处理和时序控制电路 743是具有数据运算 能力、 数据输出输入接口的中央处理器 (CPU、 MCU), 中央处理器具有控制软件、 数据处理软件。
触控电路 720的触控信号检测电路 740选择电极组 710中的电极线 71i为检测 电极， 让电极线 71i通过触控信号采样元件 7411与触控激励源 730的输出端 731连 通，让电极组 710中的电极线 71i-l和 71i+l都与触控激励源 730的输出端 732连通 作为触控信号的回流电极； 再通过电极线 71i与电极线 71i-l间的耦合电容 Cw、 与 电极线 71i+l间的耦合电容 C1+1，形成触控信号的闭合触控回路；让电极组 710中所 有其余的电极线也都与触控激励源 730的输出端 731连通。 主机电源 761连接显示 系统的显示系统电源 755， 显示系统电源 755连接显示驱动电路 752和背光源驱动 电路 754， 显示驱动电路 752和背光源驱动电路 754分别连接显示屏 751和背光源 753。触控电路 720触控激励源 730的电源端和触控信号检测电路 740的电源端， 通 过两个让 400ΚΗζ触控信号不能顺利通过的信号隔离器件 721和 722连接主机电源 761； 触控信号检测电路 740的数据处理和时序控制器 743连接数据采样通道 742， 数据采样通道 742连接信号检测通道 741 ; 信号检测通道 741 的触控信号采样元件 7411连接在触控激励源 730和触控电极组 710的电极线之间， 信号检测通道 741内 的差分放大电路 7415通过信号滤波器 7414连接缓冲器 7412和缓冲器 7413， 缓冲 器 7412连接在触控信号采样元件 7411连接触控电极组 710电极线的端点， 缓冲器 7413连接在触控信号采样元件 7411连接触控激励源 730的端点； 数据处理和时序 控制器 743同时连接主机电路 760。
当人的手指 770靠近或接触电极线 71i时， 由于手指 770具有一定的宽度， 同 时也就触及到电极线 71i-l和电极线 71i+l，人体的介电系数远大于空气的介电系数， 使得耦合电容 Ci-1和 Ci+1 的容值增大容抗减小， 触控回路上触控信号的电流相应 变大。 由于检测电极与回流电极的引出端位于触控电极组 710的相同方向， 电极线 又具有一定电阻值， 手指在触及电极线的不同位置时， 从触控激励源输出端口到触 摸点的电极线段的线电阻值就不同， 触控回路上的电阻值就不同， 触控信号的电流 随手指 770在被触电极线上的位置而变化。 触控电路 720以扫描方式逐条选择电极 组 710的各电极线为检测电极， 通过比较不同电极线上触控信号变化的大小确定被 触电极， 以流经被触电极上触控信号变化的大小定位触摸点在被触电极上的位置。
由于触控电极组 710位于显示屏 751上基板上， 触控电极组 710各电极线也与 显示屏 751的电极间存在耦合电容 CTD。 触控激励源 730输出到触控电极线上的触 控信号， 具有通过耦合电容 CTD流入显示屏 751 电极、 再流入显示系统电源 755、 再流入主机电源 761、 再从主机电源 761流回触控激励源 730的倾向； 但由于主机 电源 761是通过信号隔离器件 721和 722连接触控激励源 730的电源端和触控信号 检测电路 740的电源端， 使得 400KHz频率的触控信号不能顺利通过， 触控信号在 触控激励源 730、 触控电极组 710电极线、 显示屏 751、 显示系统电源 755和主机电 源 761 间不能获得通畅的回路， 就防止了触控信号在触控系统和显示系统间串流， 避免触控屏与显示屏间的耦合电容对触控探测产生干扰； 同时， 触控回路内的选通 滤波器 733也阻止了其他非 400KHZ的干扰信号通过， 进一步降低了干扰信号对触 控探测的影响；触控信号检测电路 740内的信号滤波器 7414也让非 400KHz的干扰 信号不能影响触控检测的效果。
在有多个触控点时， 对于不同电极线的触控点， 可以通过比较相邻区域内不同 电极线上触控信号的大小来区分； 对于同一电极线上的不同触控点， 以各触摸点触 及时间的先后顺序来区分； 当有两个触摸点在平行于电极组 710的方向移动时， 由 于电极组 710内的电极线是折线， 触摸点在任何方向上的移动， 就会不同时间经过 不同的电极线， 让我们可以判断触摸点的位置和移动方向。 具体实施方式九
如图 8所示的电容式触控屏的手持式应用产品 800， 包括透明触控板 810、触控 电路 830、 显示系统、 主机电路 870和外壳体 880等。 显示系统具有显示屏 861、 显 示驱动电路 862、 背光源 863、 背光源驱动电路 864和显示系统电源 865等。 透明触 控板 810紧靠在显示屏 861上，背光源 863紧靠在显示屏 861的背面。主机电路 870 具有主机电源 871等。 外壳体 880上设置有电极 881。
在触控板 810朝向显示屏 861 的面上设置有透明面状电极 811 ; 在触控板 810 朝向使用者的面上设置有一组相互不相交的折线状电极组 820(有折线状的电极线 821、 822、 ...、 82Ϊ-Κ 82i、 82i+l、 ...、 82m), 相邻的电极线在不同方向具有引出 端， 电极线以具有一定电阻值的 ITO透明材料制成。 触控电路 830具有触控激励源 840和触控信号检测电路 850。 触控激励源 840的输出端口为 841和 842， 触控激励 源 840的触控信号频率选择在 400KHz; 触控信号检测电路 850是由信号检测通道 851和 852、 数据采样通道 853和 854、 数据处理和时序控制器 855组成； 信号检测 通道 851具有触控信号采样元件 8511、 缓冲器 8512和 8513、 信号滤波器 8514、 差 分放大电路 8515等； 信号检测通道 852具有触控信号采样元件 8521、 缓冲器 8522 和 8523、 信号滤波器 8524、 差分放大电路 8525等； 数据采样通道 853具有模数转 换电路， 数据采样通道 854具有模数转换电路； 数据处理和时序控制电路 855是具 有数据运算能力、 数据输出输入接口的中央处理器 (CPU、 MCU), 中央处理器具有 控制软件、 数据处理软件。
触控电路 830的触控信号检测电路 850同时选择电极组 820中的电极线 82i-l 和电极线 82i为检测电极， 让电极线 82i-l通过触控信号采样元件 8511与触控激励 源 840的输出端 841连通， 让电极线 82i通过触控信号采样元件 8512也与触控激励 源 840的输出端 841连通， 让电极组 820中的其余电极线都直接与触控激励源 840 的输出端 841连通； 以外壳体 880上的电极 881作为触控信号的回流电极， 让电极 881与触控激励源 840的输出端 842连通。 主机电源 871连接显示系统的显示系统 电源 865， 显示系统电源 865连接显示驱动电路 862和背光源驱动电路 864， 显示驱 动电路 862和背光源驱动电路 864分别连接显示屏 861和背光源 863。触控电路 830 触控激励源 840的电源端和触控信号检测电路 850的电源端， 通过两个让 400KHz 触控信号不能顺利通过的信号隔离器件 831和 832连接主机电源 871。
触控信号检测电路 850信号检测通道 851的触控信号采样元件 8511连接在触控 激励源 840和触控电极组 820的电极线 82i-l之间， 缓冲器 8512连接在触控信号采 样元件 8511连接电极线 82i-l的端点， 缓冲器 8513连接在触控信号采样元件 8511 连接触控激励源 840的端点，信号检测通道 851内差分放大电路 8515的输入端通过 信号滤波器 8514连接缓冲器 8512和 8513， 差分放大电路 8515的输出端连接数据 采样通道 853的输入端；信号检测通道 852的触控信号采样元件 8521连接在触控激 励源 840和触控电极组 820的电极线 82i之间， 缓冲器 8522连接在触控信号采样元 件 8521连接电极线 82i的端点， 缓冲器 8523连接在触控信号采样元件 8521连接触 控激励源 840的端点，信号检测通道 852内差分放大电路 8525的输入端通过信号滤 波器 8524连接缓冲器 8522和 8523， 差分放大电路 8525的输出端连接数据采样通 道 854的输入端； 数据采样通道 853和 854的输出端分别连接数据处理和时序控制 器 855的两个不同端口； 数据处理和时序控制器 853同时连接主机电路 870。
当人的手指 890靠近或接触电极线 82Ϊ-1和 82Ϊ时， 手指 890与电极线 82Ϊ-1间 产生一个耦合电容 Cw, 触控激励源 840输出到电极线 82i-l上的触控激励信号就会 通过此耦合电容 流入手指， 再通过持握产品的手掌流入产品外壳体上的回流电 极 881， 再从回流电极 881流回到触控激励源 840; 手指 890与电极线 82i间产生一 个耦合电容 d， 触控激励源 840输出到电极线 82i上的触控激励信号就会通过此耦 合电容 G流入手指， 再通过持握产品的手掌流入产品外壳体上的回流电极 881， 再 从回流电极 881流回到触控激励源 840。 由触控激励源、 触控板电极线、 手指与电 极线间的耦合电容、 外壳体上的回流电极组成触控回路。
通过检测流经触控信号采样元件 8511和 8512上触控信号电流的变化， 可找出 被触电极线。 由于电极线 82i-l和 82i在不同方向具有引出端， 电极线又具有一定电 阻值， 手指在触及电极线 82i-l和 82i的不同位置时， 从触控激励源输出端口到电极 线 82i-l上触摸点的线电阻值大时，从触控激励源输出端口到电极线 82i上触摸点的 线电阻值就小， 电极线 82i-l和 82i上触控信号的电流的比值随手指 890在被触电极 线上的位置而变化。 触控电路 830以扫描方式顺序选择电极组 820成对的电极线为 检测电极， 通过比较不同电极线上触控信号变化的大小确定被触电极， 以流经成对 的被触电极上触控信号的比值定位触摸点在被触电极上的位置。
触控板 810虽是紧靠在显示屏 861上， 由于触控板 810朝向显示屏 861的面上 具有面状电极 811， 将面状电极 811连接在主机电源 871 的接地端， 阻止了触控信 号在触控系统和显示系统间串流， 避免触控屏与显示屏间的耦合电容对触控探测产 生干扰； 同时，触控信号检测电路 850内的信号滤波器 8514和 8524也让非 400KHz 的干扰信号不能影响触控检测的效果。
在有多个触控点时， 对于不同电极线的触控点， 可以通过比较相邻区域内不同 电极线上触控信号的大小来区分； 对于同一电极线上的不同触控点， 以各触摸点触 及时间的先后顺序来区分； 当有两个触摸点在平行于电极组 820的方向移动时， 由 于电极组 820内的电极线是折线， 触摸点在任何方向上的移动， 就会不同时间经过 不同的电极线， 让我们可以判断触摸点的位置和移动方向。
以上内容是结合具体的优选实施方式对本发明所作的进一步详细说明， 不能认 定本发明的具体实施只局限于这些说明。 对于本发明所属技术领域的普通技术人员 来说， 在不脱离本发明构思的前提下， 还可以做出若干简单推演或替换， 都应当视 为属于本发明的保护范围。

Claims

权 利 要 求 书
1、 一种电容式触控屏， 包括触控基板和触控电路， 触控电路具有触控激励源和 触控信号检测电路， 触控基板上设置有触控电极组； 触控基板上设置有不少于两组 的触控电极时， 各组触控电极设置在不同的触控基板上或以绝缘层相隔离设置在同 一触控基板上； 触控基板设置在应用产品上， 应用产品具有显示系统 (包括显示屏及 其驱动电路、 背光源及其驱动电路)； 触控激励源的第一输出端用于在检测时段的至 少部分时刻对连接的电极线施加触控信号； 触控信号检测电路用于在检测时段的至 少部分时刻选择其中至少部分电极线为触控检测电极， 来探测该部分电极线是否被 触碰； 所述触控检测电极是指在对该电极施加有触控信号的同时， 还检测流经该电 极触控信号变化的电极； 其特征在于： 触控电路在选择部分电极为检测电极的同时， 还选择触控基板的部分电极线为 触控回流电极； 所述触控回流电极是指， 在对触控检测电极施加触控信号并检测流 经其触控信号变化的时刻， 连通于触控激励源的第二输出端或连通于另一触控激励 源， 为检测电极上的触控信号提供回流通路的触控电极。
2、 根据权利要求 1所述的电容式触控屏， 其特征在于： 所述触控回流电极是部分的或所有的与触控检测电极不相交的电极线， 或是部 分的或所有的与触控检测电极相交的电极线， 或是部分的或所有的与触控检测电极 相交的和不相交的电极线。
3、 根据权利要求 2所述的电容式触控屏， 其特征在于： 所述与触控检测电极不相交的触控回流电极是触控检测电极的相邻一侧或两侧 的电极线。
4、 一种电容式触控屏， 包括触控基板和触控电路， 触控电路具有触控激励源和 触控信号检测电路， 触控基板上设置有触控电极组； 触控基板上设置有不少于两组 的触控电极时， 各组触控电极设置在不同的触控基板上或以绝缘层相隔离设置在同 一触控基板上； 触控基板设置在应用产品上， 应用产品具有显示系统 (包括显示屏及 其驱动电路、 背光源及其驱动电路)； 触控激励源的第一输出端用于在检测时段的至 少部分时刻对连接的电极线施加触控信号； 触控信号检测电路用于在检测时段的至 少部分时刻选择其中至少部分电极线为触控检测电极， 来探测该部分电极线是否被 触碰； 所述触控检测电极是指在对该电极施加有触控信号的同时， 还检测流经该电 极触控信号变化的电极； 其特征在于： 应用产品外壳体上设置有电极； 触控电路选择应用产品外壳体上的电极为触控 回流电极； 所述触控回流电极是指， 在对触控检测电极施加触控信号并检测流经其 触控信号变化的时刻， 连通于触控激励源的第二输出端或连通于另一触控激励源， 为检测电极上的触控信号提供回流通路的触控电极。
5、 根据权利要求 1或 4所述的电容式触控屏， 其特征在于： 所述触控基板是挠性的或硬性的透明基板。
6、 根据权利要求 1或 4所述的电容式触控屏， 其特征在于： 所述触控电极是显示屏电极。
7、 根据权利要求 1或 4所述的电容式触控屏， 其特征在于： 所述触控电路同时对触控基板上的多条触控检测电极进行触控探测。
8、 根据权利要求 1或 4所述的电容式触控屏， 其特征在于： 所述触控检测电极与触控回流电极所连通的同一触控激励源不同输出端上的或 不同触控激励源输出端上的触控信号是不同的。
9、 根据权利要求 8所述的电容式触控屏， 其特征在于： 所述触控信号的不同是指触控信号的幅值、 相位、 频率中至少一项不同。
10、 根据权利要求 1或 4所述的电容式触控屏， 其特征在于： 所述触控电路与应用产品的主机电路和显示系统之间， 或触控电路电源与应用 产品的主机电路电源和显示系统电源之间， 或触控电路的触控激励源与应用产品的 主机电路电源和显示系统电源之间， 设置有信号隔离器件； 所述信号隔离器件是触 控信号的高阻器件。
11、 根据权利要求 1或 4所述的电容式触控屏， 其特征在于： 所述触控基板上的触控电极是一组不交的电极线， 触控电路通过比较不同电极 线上触控信号变化的大小确定被触电极， 以流经被触电极上触控信号变化的大小定 位触摸点在被触电极上的位置。
12、 根据权利要求 1或 4所述的电容式触控屏， 其特征在于： 所述触控基板上的触控电极是一组不交的电极线， 不同电极线在不同方向具有 引出端， 取不同方向引出端的电极线为检测电极； 触控电路通过比较不同触控电极 线上触控信号变化的大小确定被触电极， 通过比较不同方向引出端的检测电极上触 控信号变化的大小定位触摸点在被触电极上的位置。
13、 根据权利要求 11或 12所述的电容式触控屏， 其特征在于： 所述不交的电极线是折线。
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