TW201305892A - Touch detecting method, touch sensitive device, and portable electronic apparatus - Google Patents

Abstract

A touch detecting method, a touch sensitive device and a portable electronic apparatus are provided. The touch detecting method comprises: applying a high level signal to one of a first electrode and a second electrode of one of a plurality of induction units, and grounding the other of the first electrode and the second electrode to charge a self capacitor for a first time; applying a high level signal to the first electrode and the second electrode to charge the self capacitor for a second time; grounding the first electrode and the second electrode of the one induction unit, or grounding one of the first electrode and the second electrode and breaking the other to discharge the self capacitor for a first time; detecting at the corresponding first electrode or the corresponding second electrode to obtain a second detecting variation between the second time charging and the first time discharging; and calculating a touch position according to a first detecting variation and the second detecting variation.

Description

Touch detection method, touch device and portable electronic device

The present invention relates to the field of electronic device design and manufacturing technology, and in particular, to a touch detection method for a touch screen, a touch device, and a portable electronic device.

At present, the application range of touch screens has been rapidly expanded from mobile phone ATMs such as bank ATMs and industrial computer computers to mobile phones, PDAs (personal digital assistants), GPS (Global Positioning System), PMP (MP3, MP4, etc.) and even tablets. Computer and other fields of mass consumer electronics. The touch screen has the advantages of simple, convenient and user-friendly touch operation, so the touch screen is expected to be the best interface for human-computer interaction and has been widely used in portable devices.
Capacitive touch screens are usually divided into two types: self-capacitance and mutual capacitance. As shown in FIG. 1, it is a structural diagram of a self-capacitive touch screen that is common in the prior art. The self-capacitive touch screen mainly has double-layered diamond-shaped structure sensing units 100' and 200'. The detection principle is to scan the X-axis and the Y-axis respectively. If the capacitance change of a certain intersection is detected beyond the preset range, then Use the intersection of the row and column as the touch coordinates. Although the self-capacitance touch screen has a good linearity, there are often ghost points that make it difficult to achieve multi-touch. In addition, due to the use of a double-layer screen, the structure and cost are greatly increased, and the rhombic structure may have coordinate shifts when the amount of capacitance change is small, which is greatly affected by external interference.
As shown in Fig. 2a, it is a structural diagram of another self-capacitive touch screen that is common in the prior art. The self-capacitive touch screen adopts a triangular graphic screen structure. The self-capacitive touch screen includes a substrate 300', a plurality of triangular sensing units 400' disposed above the substrate 300', and a plurality of electrodes 500' connected to each of the triangular sensing units 400'. As shown in Figure 2b, it is the detection principle of the triangular self-capacitance touch screen. As shown, the ellipse represents the finger, and S1, S2 represent the contact area of the finger with the two triangular sensing units. Assuming that the coordinate origin is in the lower left corner, the abscissa X = S2 / (S1 + S2) * P, where P is the resolution. When the finger moves to the right, there is a deviation in the X coordinate since S2 does not increase linearly. It can be seen from the above principle that the current triangular sensing unit is single-ended detection, that is, detecting only from one direction, and then calculating the coordinates in two directions by an algorithm. Although the self-capacitive touch screen structure is simpler, it is not optimized for the capacitive sensing of the screen, and the capacitance variation is small, resulting in insufficient signal-to-noise ratio. In addition, since the sensing unit is triangular, the area does not increase linearly when the finger moves laterally, so the linearity is poor, resulting in offset calculation of the coordinates, and the linearity is not good enough.
In addition, the capacitance sensing unit has a small amount of change in the output capacitance, reaching the flying level, and the presence of the stray capacitance of the cable puts higher requirements on the measuring circuit. Moreover, the stray capacitance will vary with temperature, position, internal and external electric field distribution and other factors, and even interfere with the measured capacitance signal. In addition, for a single-layer capacitor, the influence of the Vcom level signal may cause serious interference to the sensing capacitor, wherein the Vcom level signal is a level signal for preventing the LCD screen from aging and not flipping.

It is an object of the present invention to address at least one of the above-mentioned technical deficiencies, and in particular to solve or avoid the above-mentioned disadvantages of existing self-capacitive touch screens.
A first aspect of the present invention provides a touch detection method for a touch screen, the touch screen including a plurality of disjoint sensing units, each of which has a first electrode and a second electrode, respectively, the method comprising the following Step: applying a high level signal to one of the first electrode and the second electrode of one of the plurality of sensing units, and grounding the other of the first electrode and the second electrode to The first self-capacitance generated by the one sensing unit is first charged when a sensing unit is touched; the high level signal is applied to the first electrode and the second electrode of one of the plurality of sensing units, or Applying a high level signal to one of the first electrode and the second electrode and disconnecting the other of the first electrode and the second electrode to perform a second on the self capacitance Sub-charging; detecting from the corresponding first electrode or second electrode to obtain a first detected change value between the first charging and the second charging; The electrode and the second electrode are grounded, or one of the first electrode and the second electrode is grounded and the other of the first electrode and the second electrode is disconnected to Capacitor performing a first discharge; detecting from the corresponding first electrode or second electrode to obtain a second detected change value between the second charge and the first discharge; according to the first Detecting a change value and a second detected change value calculating a proportional relationship between the first resistance between the self-capacitance to the first electrode and the second resistance between the self-capacitance and the second electrode; A proportional relationship between the first resistance and the second resistance determines a touch position.
According to a second aspect of the present invention, a touch device includes: a substrate; a plurality of disjoint sensing units, wherein the plurality of sensing units are formed on the substrate, and each of the sensing units has a first end An electrode and a second electrode; a touch screen control chip, the touch screen control chip includes a charging module, a discharging module and a detecting module, wherein the charging module is used for the first charging process Applying a high level signal to one of the first electrode and the second electrode of one of the plurality of sensing units, and grounding the other of the first electrode and the second electrode to be in the one sensing Capturing a self-capacitance generated by the one sensing unit for a first time when the unit is touched; applying a high voltage to the first electrode and the second electrode of one of the plurality of sensing units during the second charging process Level signal, or applying a high level signal to one of the first electrode and the second electrode and disconnecting the other of the first electrode and the second electrode to perform the The charging module is configured to ground the first electrode and the second electrode of the one sensing unit after the charging module performs the second charging of the self-capacitor, or One of the electrodes and the second electrode is grounded and the other of the first electrode and the second electrode is disconnected to perform a first discharge of the self-capacitor, and the detection module, Detecting from the corresponding first or second electrode to obtain a first detected change value between the first charge and the second charge, and from the corresponding first electrode or The second electrode performs detection to obtain a second detection change value between the second charge and the first discharge, and a control and calculation module for the charging module, the discharge module, and the detection Controlling, and calculating, according to the first detection change value and the second detection change value, the first resistance between the self-capacitance to the first electrode and the self-capacitance to the second electrode a proportional relationship between the two resistors, and according to the first resistor The ratio between the second resistor to determine the touch location.
A third aspect of the present invention also provides a portable electronic device comprising the touch device as described above.
The sensing unit in the touch device of the present invention adopts double-end detection, that is, both ends of the sensing unit have electrodes, and each electrode is connected to a corresponding pin of the touch screen control chip, and passes through the sensing unit itself when performing touch detection. The positioning of the touch points can be achieved.
More importantly, the present invention achieves the determination of the touch position by calculating the ratio between the first resistance and the second resistance, so that compared to the current diamond or triangle design, since the touch position is determined, there is no need to calculate the self-capacitance. The size and the size of the self-capacitance do not affect the accuracy of the touch position, thereby improving measurement accuracy and improving linearity.
The present invention applies a level signal to the electrodes at both ends of the sensing unit. If the sensing unit is touched, touching an object (such as a finger) will form a self-capacitance with the sensing unit, so the present invention can apply the level signal by applying the level signal. The self-capacitance is charged, and the touch position on the touch screen is determined according to a proportional relationship between the first resistance and the second resistance. And the detection method of charging the self-capacitance twice by the embodiment of the invention to cancel some unmeasurable physical parameters or reduce the measurement of the physical quantity, thereby effectively improving the detection precision under the premise of ensuring the detection speed.
The invention provides a novel self-capacitance detection method. When the sensing unit is touched, the touch point can divide the sensing unit into two resistors, so that the two resistors can be determined while taking the self-capacitance detection. The position on the sensing unit. The structure of the embodiment of the invention is simple, and for a sensing unit, detecting when charging or discharging can not only reduce the RC constant, save time and improve efficiency, but also ensure that the coordinates are not offset. In addition, the embodiment of the invention can effectively improve the performance-to-noise ratio of the circuit, reduce circuit noise, and improve the linearity of the induction. In addition, since the touched sensing unit is charged during the detection process, a small current is generated therein, which can well eliminate the influence of the Vcom level signal on the self-capacitance generated by the sensing unit in the touch screen, and thus can be eliminated accordingly. The screen mask layer and related processes can further reduce the cost while enhancing the anti-interference ability.
The additional aspects and advantages of the invention will be set forth in part in the description which follows.

The embodiments of the present invention are described in detail below, and the examples of the embodiments are illustrated in the drawings, wherein the same or similar reference numerals are used to refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are intended to be illustrative of the invention and are not to be construed as limiting.
The embodiment of the invention provides a novel self-capacitance detection method. When the sensing unit is touched, the touch point can divide the sensing unit into two resistors, and the two resistors can be used to determine the touch while performing self-capacitance detection. The position on the sensing unit. FIG. 3 is a schematic diagram of a detection principle of a touch device according to an embodiment of the present invention. When the finger touches the sensing unit, it will be equivalent to splitting the sensing unit into two resistors, and the resistance values of the two resistors are related to the position of the touch point. For example, as shown in the figure, when the touch point is closer to the first electrode 210, the resistor R1 is smaller and the resistor R2 is larger; conversely, when the touch point is closer to the second electrode 220, the resistor R1 is It is larger and the resistance R2 is smaller. Therefore, the present invention can determine the position of the touch point on the sensing unit by detecting the resistors R1 and R2. In an embodiment of the present invention, the resistors R1 and R2 are detected in various ways, for example, by detecting a current detection change value of the first electrode and the second electrode, a self-capacitance detection change value, a level signal detection change value, and a charge change amount. One or more of them, thereby obtaining resistors R1 and R2 based on these detected change values. And the present invention improves the measurement accuracy by charging the self-capacitance formed by the touch point twice to offset some unmeasurable physical parameters or to reduce the measurement of the physical quantity.
It should be noted that, in the embodiment of the present invention, the functions of the first electrode and the second electrode are the same, and the two are interchangeable. Therefore, in the above embodiment, the first electrode may be detected from the first electrode or the second The electrode detection can be performed as long as it satisfies the requirement that a current needs to pass through the first resistor and the second resistor during charging, discharging or detecting.
In the embodiment of the present invention, the corresponding voltages may be sequentially applied to the plurality of sensing units in a scanning manner, and may also be sequentially detected in a scanning manner during the detection.
As shown in FIG. 4, it is a flowchart of a touch detection method according to an embodiment of the present invention, which is described together with the schematic diagram shown in FIG. The method includes the following steps:
Step S401, applying a high level signal to one of the first electrode and the second electrode of one of the plurality of sensing units, and grounding the other of the first electrode and the second electrode to When the sensing unit is touched, the self-capacitance generated by the sensing unit is charged for the first time. In this embodiment, a high level signal Vcc is applied to one of the first electrode and the second electrode.
If the sensing unit is touched by a finger or other object at this time, the sensing unit will generate a self-capacitance C1 (refer to FIG. 3), so the self-capacitance can be charged by the applied high-level signal Vcc. At this time, in one embodiment of the present invention, if a high level signal is applied to the first electrode, the voltage applied to the self capacitance is V2 = VccR2 / (R1 + R2). In one embodiment of the invention, if a high level signal is applied to the second electrode, the voltage applied to the self capacitance is V1 = VccR1/(R1 + R2).
Further, in the embodiment of the present invention, by charging the self-capacitance, the detection accuracy of the self-capacitance can also be improved.
In one embodiment of the present invention, if the sensing unit is not touched, the presence of self-capacitance will not be detected subsequently, so it can be judged that it is not touched.
Step S402, applying a high level signal to the first electrode and the second electrode of one sensing unit, or applying a high level signal to one of the first electrode and the second electrode and in the first electrode and the second electrode The other is disconnected to charge the self capacitor a second time.
In the embodiment of the present invention, a high level signal may be applied to both the first electrode and the second electrode; or, a high level signal may be applied to the first electrode to disconnect the second electrode; or, to the second electrode A high level signal turns off the first electrode. It should also be noted that since the applied high level signal is a known amount, the two high level signals applied may be the same or different, and the derivation process is not affected. In this embodiment, the same high level signal Vcc as that in step S401 is applied to the first electrode and/or the second electrode. The voltage applied to the self-capacitance at this time is Vcc.
Step S403, detecting from the corresponding first electrode or the second electrode to obtain a first detection change value between the first charge and the second charge. In the embodiment of the present invention, the correspondence refers to a case where, for example, when both the first electrode and the second electrode of one sensing unit are connected to a high level signal for charging, both the first electrode and the second electrode are The detection can be performed; for example, when the first electrode is connected to the high level signal and the second electrode is disconnected, it can only be detected from the first electrode; conversely, when the second electrode is connected to the high level signal and the first electrode is disconnected, It can only be detected from the second electrode.
In the embodiment of the present invention, as long as the second charging is performed in a different manner from the first charging, a change in the amount of charge in the self-capacitance may be caused. In addition, the self-capacitance is discharged after the detection to perform the next charge and discharge process.
In this embodiment, it is assumed that the first detection change value is Q1. Hereinafter, the first detection change value and the second detection change value are described as an example of the charge change amount, but other detection change values such as a level signal, a current, and the like which can react the relationship between the resistances R1 and R2 can also be employed.
Wherein, if a high level signal is applied to the first electrode in step 401, then Q1 = V1C1 = VccC1R1/(R1 + R2) (1a), where V1 = VccR1/(R1 + R2). At this time, the voltage of the self-capacitance at the time of the first charge is V2, and the self-capacitance voltage can be detected or calculated at the time of the first charge.
Wherein, if a high level signal is applied to the second electrode in step 401, then Q1 = V2C1 = VccC1R2 / (R1 + R2) (1b), where V2 = VccR2 / (R1 + R2). At this time, the voltage of the self-capacitance at the time of the first charge is V1, and the self-capacitance voltage can be detected or calculated at the time of the first charge.
Step S404, grounding the first electrode and the second electrode of one sensing unit, or grounding one of the first electrode and the second electrode and disconnecting the other of the first electrode and the second electrode to The capacitor is discharged for the first time.
Specifically, the first electrode and the second electrode of one sensing unit may be grounded, or the first electrode may be grounded, and the second electrode may be grounded, or the second electrode may be grounded, and the first electrode may be disconnected. The first discharge is performed on the self-capacitance.
Step S405, detecting from the corresponding first electrode or the second electrode to obtain a second detection change value between the second charge and the first discharge.
In this embodiment, it is assumed that the second detection change value is Q2. The second detected change value needs to adopt the same detected change value as the first detected change value in step S403, that is, the charge change amount in the embodiment of the present invention. Likewise, the term "corresponding" as used herein is also a relative concept, for example, in the first discharge, if the second electrode is broken, detection can only be performed from the first electrode.
among them, Q2= VccC1 (2)
Step S406, calculating a proportional relationship between the first resistance between the self-capacitance to the first electrode and the second resistance between the self-capacitance and the second electrode according to the first detection change value and the second detection change value, and according to the first resistance The proportional relationship with the second resistance determines the touch position. In one embodiment of the present invention, the ratio of R1 to R2 can be calculated by the amount of change in self-capacitance charge expressed by equations (1a) (or 1b) and (2), which can be calculated due to the regular linear relationship of the graph. The position of the abscissa where the touch point is located, and the position where the self-capacitance C1 is located.
In an embodiment of the invention, if a high level signal is applied to the first electrode in step 401, then R1/R2= Q1 / ( Q2- Q1), therefore, the proportional relationship between R1 and R2 can be obtained by the embodiment of the present invention.
In an embodiment of the invention, if a high level signal is applied to the second electrode in step 401, then R1/R2 = ( Q2- Q1)/ Q1, therefore, the proportional relationship between R1 and R2 can be obtained by the embodiment of the present invention.

In the embodiment of the present invention, if the sensing unit is a gate sensing unit or an L-shaped sensing unit, the touch position on the touch screen can be determined by the ratio between the first resistor and the second resistor, and the following will be combined The examples are detailed. However, in other embodiments of the present invention, if the sensing unit is a rectangular sensing unit or a serpentine (but generally rectangular) sensing unit, step S406 can only calculate the touch position in the first direction of the touch screen. The first direction may be the length direction of the sensing unit (eg, the level of the touch screen).
If the sensing unit is a rectangular sensing unit or a serpentine (but overall equivalent to a rectangular) sensing unit, it is also necessary to determine the touch position in the second direction according to the position of the sensing unit. In an embodiment of the invention, the first direction is a length direction of the sensing unit, the second direction is a direction perpendicular to the sensing unit, and the sensing unit is horizontally or vertically disposed.
In the embodiment of the present invention, the self-capacitance detecting module can be a self-capacitance detecting module that is currently known, and thus will not be described herein.
In one embodiment of the present invention, if two self-capacitance detection modules are used, since the two self-capacitance detection modules can share a plurality of devices, the overall power consumption of the wafer is not increased.
In one embodiment of the invention, the sensing unit can take a different shape. Preferably, the plurality of disjoint sensing units are located in the same layer, so that in the case of ensuring the detection accuracy, the cost can be greatly saved.
In the above embodiment of the present invention, although the first charging, the second charging, and the first discharging are taken as an example, in the present invention, as long as there are three different states, by measuring any two different states. The proportional relationship between R1 and R2 can be obtained by the difference in state (i.e., the detected change value). In this embodiment, the three different states are the state after the first charge, the state after the second charge, and the state after the discharge.

As shown in FIG. 5, it is a schematic diagram of a rectangular sensing unit being touched according to an embodiment of the present invention. The sensing unit is rectangular, and the plurality of sensing units are parallel to the first direction of the touch screen, and thus the touch position is a touch position in the first direction.
As shown in Fig. 6a, it is a structural diagram of an induction unit according to an embodiment of the present invention. The sensing unit 200 includes a plurality of first portions 230 and a plurality of parallel second portions 240, wherein adjacent first portions 230 are connected by a second portion 240 to form a plurality of alternately arranged first grooves 1000 and Two grooves 2000, wherein the openings of the plurality of first grooves 1000 and the plurality of second grooves 2000 are opposite in direction. Preferably, the second portions 240 are aligned in a first direction. In one embodiment of the invention, the plurality of first portions 230 may or may not be parallel to one another. Preferably, the second portion 240 is rectangular. In other embodiments of the invention, the first portion 230 can also be rectangular, but the first portion 230 can also have a variety of other shapes. In this embodiment, the impedance of the resistor is increased by the first portion 230, thereby increasing the impedance of the sensing unit 200, making the first resistor and the second resistor easier to detect, further improving the detection accuracy. And in this embodiment, preferably, the intervals between the second portions 240 are equal, so that the impedance of the sensing unit can be uniformly increased to improve the detection accuracy. In one embodiment of the present invention, the first direction is the length direction of the sensing unit 200, and the second direction is the direction perpendicular to the sensing unit 200. Specifically, the sensing unit 200 is horizontally or vertically.
In the embodiment of the present invention, the size of the sensing unit 200 in the longitudinal direction is substantially the same as the size of the substrate. Therefore, the touch device has a simple structure, is easy to manufacture, and has low manufacturing cost.
In one embodiment of the invention, the first electrode 210 and the second electrode 220 are respectively connected to two of the plurality of first portions 230. However, in another embodiment of the invention, the first electrode 210 and the second electrode 220 are respectively coupled to two of the plurality of second portions 240, as shown in Figure 6b.
Moreover, in the embodiment of the present invention, the second portion 240 and the first portion 230 are perpendicular to each other, and the angle between them is preferably 90 degrees, and of course other angles may be selected. As shown in FIG. 6a, the sensing unit 200 connects the plurality of first portions 230 end to end through a plurality of second portions 240. The first electrode 210 and the second electrode 220 of the sensing unit 200 are respectively connected to the first portions 230 at both ends. The sensing unit 200 is a rectangle having a large aspect ratio as a whole. It should be noted that although the sensing unit 200 is disposed along the X axis in FIG. 6a, it should be understood by those skilled in the art that the sensing unit 200 can also be disposed along the Y axis. The structure of the sensing unit can effectively reduce noise and improve linearity of sensing.
As shown in Fig. 7a, there is shown a structural diagram of a sensing unit according to another embodiment of the present invention. In this embodiment, the sensing unit 200 can be gate-shaped, and each of the plurality of sensing units 200 has a different length, and the plurality of sensing units 200 are nested with each other. Wherein each of the sensing units includes a third portion 250, a non-intersecting fourth portion 260, and a fifth portion 270. Preferably, the third portion 250 is parallel to the first side 110 of the substrate 100, the fourth portion 260 and the fifth portion 270 are respectively parallel to the second side 120 of the substrate 100, and one end of the fourth portion 260 and one end of the third portion 250 Connected, one end of the fifth portion 270 is connected to the other end of the third portion 250. The other end of the fourth portion 260 of the sensing unit 200 has a first electrode 210, and the other end of the fifth portion 270 has a second electrode 220, wherein each of the first electrode 210 and the second electrode 220 is associated with a touch screen control wafer The corresponding pins are connected.
In the embodiment of the present invention, the mutual nesting means that the outer sensing unit partially surrounds the inner sensing unit, for example, as shown in FIG. 7a, which can achieve a large coverage while ensuring accuracy, and is reduced. The complexity of the operation increases the response speed of the touch screen. Of course, those skilled in the art can also arrange the sensing units in other nested manners according to the idea of FIG. 7a. In one embodiment of the invention, the third portion 250 of each sensing unit 200 is parallel to the third portion 250 of the other sensing unit 200, and the fourth portion 260 of each sensing unit 200 and the fourth portion of the other sensing unit 200 The second portion 270 of each sensing unit 200 is parallel to the fifth portion 270 of the other sensing unit 200. In one embodiment of the invention, at least one of the third portion 250, the fourth portion 260, and the fifth portion 270 of the sensing unit 200 is rectangular, preferably, the third portion 250, the fourth portion 260, and the fifth portion 270 Both are rectangular. In this embodiment, since the rectangular structure pattern is regular, the linearity is good when the finger is moved laterally or longitudinally. In addition, the spacing between the two rectangular structures is the same, which is convenient for calculation, thereby increasing the calculation speed.
In one embodiment of the invention, the fourth portion 260 of each sensing unit 200 is equal in length to the fifth portion 270.
In one embodiment of the invention, the substrate 100 is rectangular, the first side 110 and the second side 120 are perpendicular to each other, and the fourth portion 260 and the third portion 250 are perpendicular to each other, and the fifth portion 270 and the third portion The portions 250 are perpendicular to each other.
In one embodiment of the present invention, the spacing between the third portions 250 of the adjacent two sensing units 200 is equal, the spacing between the fourth portions 260 of the adjacent two sensing units 200 is equal, and the adjacent two sensing The spacing between the fifth portions 270 of unit 200 is equal. In this way, the first side 110 and the second side 120 of the touch screen can be evenly divided by the plurality of sensing units 200, thereby increasing the operation speed. Of course, in other embodiments of the present invention, the spacing between the third portions 250 of the adjacent two sensing units 200 may not be equal, or the spacing between the fourth portions 260 of the adjacent two sensing units 200 may not be Equal, as shown in Figure 7b. For example, since the user often touches the center of the touch screen, the spacing between the sensing units at the center of the touch screen can be reduced, thereby improving the detection accuracy of the center portion.
In one embodiment of the present invention, the plurality of sensing units 200 are symmetrical with respect to the central axis Y of the substrate 100. As shown in FIG. 7a, the central axis Y is perpendicular to the third portion 250, thereby being more advantageous for improving accuracy.
As shown in FIG. 7a, in this embodiment, the first electrode 210 and the second electrode 220 of the sensing unit 200 are both located on the first side 110 of the substrate 100. In this embodiment, after detecting the touch location on the sensing unit, a touch location above the touch screen is obtained.
It should be noted that the above-mentioned FIG. 7a is a preferred embodiment of the present invention, which can obtain a large coverage, but other embodiments of the present invention can perform some equivalent changes to the 7a figure, for example, the fourth portion 260. And the fifth portion 270 can be non-parallel.
The sensing unit in the embodiment of the invention adopts a gate-like structure, which is not only simple in structure, but also easy to manufacture. All the leads are on the same side, the design is convenient, the cost of the silver paste is reduced, and the production is easy, which greatly helps to reduce the production cost.
As shown in FIG. 8, it is a schematic diagram when the sensing unit of the embodiment of the present invention is touched. As can be seen from FIG. 8, the first electrode is 210, the second electrode is 220, the touch position A is close to the second electrode, and the length of the sensing unit is 10 unit lengths, and the sensing unit is evenly divided into 10 parts, wherein The length of the third portion 250 of the sensing unit is 4 unit lengths, and the lengths of the fourth portion 260 and the fifth portion 270 of the sensing unit are 3 unit lengths. After detecting, it is learned that the ratio of the first resistance to the second resistance is 4:1, that is, the length of the first electrode 210 to the touch position (reflected by the first resistance) is 80% of the length of all the sensing units. In other words, the touch point is located at a position of 8 unit lengths from the first electrode 210, and it is known that the touch point is located 2 units long from the second electrode 220. When the finger moves, the touch position moves accordingly, so the change of the touch position can determine the corresponding movement trajectory of the finger, thereby judging the user's input instruction.
As can be seen from the above example of Fig. 8, the calculation method of the present invention is very simple, so that the reaction speed of the touch screen detection can be greatly improved. In the embodiment of the present invention, usually a finger or other object touches a plurality of sensing units, and at this time, the touch position of each of the plurality of sensing units touched may be obtained first, and then calculated by averaging. Touch the touch location on the screen.

As shown in FIG. 9a, it is a structural diagram of a touch screen detecting device according to still another embodiment of the present invention. In one embodiment of the invention, the lengths of the plurality of sensing units are gradually increased, and each of the sensing units includes a sixth portion 280 and a seventh portion 290. The sixth portion 280 has a first electrode 210 at one end, one end of the seventh portion 290 is connected to the other end of the sixth portion 280, and the other end of the seventh portion 290 has a second electrode 220.
Specifically, the sixth portion 280 is parallel to the first side 110 of the substrate 100, the seventh portion 290 is parallel to the second side 120 of the substrate 100, and the first side 110 and the second side 120 are adjacent. And each of the first electrode 210 and the second electrode 220 is connected to a corresponding pin of the touch screen control wafer.
In a preferred embodiment of the invention, the sixth portion 280 of each sensing unit 200 is parallel to the sixth portion 280 of the other sensing unit 200, and the seventh portion 290 of each sensing unit 200 and the seventh portion of the other sensing unit 200 290 parallel. With such an arrangement, the coverage of the touch screen by the sensing unit can be effectively improved. In one embodiment of the present invention, at least one of the sixth portion 280 and the seventh portion 290 of the sensing unit 200 is rectangular. Preferably, the sixth portion 280 and the seventh portion 290 are both rectangular. In this embodiment, since the rectangular structure pattern is regular, the linearity is good when the finger is moved laterally or longitudinally, and further, the spacing between the two rectangular structures is the same, which is convenient for calculation.
The sensing unit in the touch screen detecting device of the embodiment of the invention adopts double-end detection, that is, both ends of the sensing unit have electrodes, and each electrode is connected to a corresponding pin of the touch screen control chip, and passes through the touch detection. The sensing unit itself can realize the positioning of the touch point.
More importantly, the present invention achieves the determination of the touch position by calculating the ratio between the first resistance and the second resistance, so that compared to the current diamond or triangle design, since the touch position is determined, there is no need to calculate the self-capacitance. The size and the size of the self-capacitance do not affect the accuracy of the touch position, and the dependence on the accuracy of the self-capacitance detection is reduced, thereby improving the measurement accuracy and improving the linearity. In addition, since any one of the sixth portion 280 and the seventh portion 290 of the embodiment of the present invention may be a rectangular shape, the linearity may be further improved with respect to an irregular shape such as a current rhombus or a triangle. degree.
In one embodiment of the invention, the sixth portion 280 and the seventh portion 290 of each sensing unit are of equal length so that the speed of operation can be increased. Preferably, the substrate 100 is rectangular, and the first side 110 and the second side 120 are perpendicular to each other. The first side 110 and the second side 120 are perpendicular to each other, not only making the sensing unit design more regular, for example, the sixth portion 280 and the seventh portion 290 of the sensing unit are also perpendicular to each other, thereby improving the coverage of the touch screen, and The fact that the sixth portion 280 and the seventh portion 290 are perpendicular to each other also improves the linearity of the detection.
In one embodiment of the invention, the spacing between adjacent two sensing units 200 is equal. In this way, the first side 110 and the second side 120 of the touch screen can be evenly divided by the plurality of sensing units 200, thereby increasing the operation speed.
Of course, in another embodiment of the present invention, the spacing between adjacent two sensing units 200 may also be unequal, as shown in FIG. 9b, for example, since the user often touches the center of the touch screen, the touch can be touched. The spacing between the sensing units in the center of the screen is reduced, thereby improving the detection accuracy of the center portion.
As shown in FIG. 9a, in this embodiment, the first electrode 210 of the sensing unit 200 is located on the first side 110 of the substrate 100, the second electrode 220 is located on the second side 120 of the substrate 100, and the first side 110 The second side 120 is perpendicular to each other. In this embodiment, after detecting the touch location on the sensing unit, a touch location above the touch screen is obtained.
As shown in FIG. 10, it is a schematic diagram when the sensing unit of the embodiment of the present invention is touched. As can be seen from FIG. 10, the first electrode is 210, the second electrode is 220, and the touch position A is close to the second electrode 220. It is assumed that the length of the sensing unit is 10 unit lengths, and the sensing unit is evenly divided into 10 parts. The length of the sixth portion 280 of the sensing unit is 5 unit lengths, and the length of the seventh portion 290 of the sensing unit is 5 unit lengths. After detecting, it is known that the ratio of the first resistance to the second resistance is 9:1, that is, the length of the first electrode 210 to the touch position (reflected by the first resistance) is 90% of the length of all the sensing units. In other words, the touch point is located 9 units long from the first electrode 210, and it is known that the touch point is located 1 unit long from the second electrode 220.
As can be seen from the above example of Fig. 10, the calculation method of the present invention is very simple, so that the reaction speed of the touch screen detection can be greatly improved.
In one embodiment of the present invention, the plurality of sensing units 200 are located in the same layer, so that only one layer of ITO is required, thereby greatly reducing the manufacturing cost while ensuring accuracy.
In summary, the embodiment of the present invention applies a level signal to the electrodes at both ends of the sensing unit. If the sensing unit is touched, the sensing unit forms a self-capacitance. Therefore, the present invention can be applied by applying a level signal. The self capacitance is charged, and the touch position in the first direction is determined according to a proportional relationship between the first resistance and the second resistance. For example, in an embodiment of the present invention, the proportional relationship between the first resistance and the second resistance is obtained according to the detection of the first electrode and/or the second electrode when charging/discharging the self-capacitance. The proportional relationship between the first detected value and the second detected value is calculated. Therefore, the first detection value and the second detection value generated when the self-capacitance is charged/discharged are detected from the first electrode and/or the second electrode. In this way, the position of the touch point at the sensing unit can be reflected by the first detection value and the second detection value, thereby further determining the position of the touch point on the touch screen.
For the sensing unit of FIGS. 5 and 6, after determining the touch position in the first direction, it is further necessary to further determine the touch position in the second direction according to the position of the touched sensing unit. In the embodiment of the present invention, as shown in FIG. 5 and FIG. 6 , if it is detected that the first detection value or the second detection value of a certain sensing unit is greater than a preset threshold, the sensing unit is touched. Assuming that the second sensing unit (its ordinate is M) is touched, the touch position in the second direction is the coordinate M of the second sensing unit. Then, the position of the touch point on the touch screen is determined according to the touch position in the first direction and the touch position in the second direction.
Specifically, the centroid algorithm can be used to calculate the touch position of the touch point in the second direction. The following describes the centroid algorithm briefly.
In slider and touchpad applications, it is often necessary to determine the position of a finger (or other capacitive object) above the essential spacing of a particular sensing unit. The touch panel of the finger on the slider or touchpad is typically larger than any of the sensing units. In order to use a center to calculate the position after the touch, the array is scanned to verify that the given sensor position is valid, and the requirement for a certain number of adjacent sensing unit signals is greater than the preset touch threshold. After finding the strongest signal, this signal and those adjacent to the touch threshold are used in the calculation center:

Ncent is the label of the sensing unit at the center, n is the number of sensing units that are touched, and i is the serial number of the touched sensing unit, where i is greater than or equal to 2.
For example, when the finger touches the first channel, the capacitance change amount is y1, the capacitance change amount on the second channel is y2, and the capacitance change amount on the third channel is y3. The second channel y2 capacitance changes the most. The Y coordinate can be regarded as:

FIG. 11 is a schematic diagram of a touch device according to an embodiment of the present invention. The touch device includes a touch screen detecting device composed of a substrate 100 and a plurality of disjoint sensing units 200, and a touch screen control wafer 300. Wherein, the plurality of sensing units 200 are formed on the substrate 100, and each of the plurality of sensing units 200 has a first electrode 210 and a second electrode 220. A part of the touch screen control chip 300 is connected to the first electrode 210 of the plurality of sensing units 200, and another part of the touch screen control wafer 300 is connected to the second electrode 220 of the plurality of sensing units 200, and touches the screen. The control wafer 300 applies a level signal to the first electrode 210 and/or the second electrode 220 of the plurality of sensing units 200, which level signal charges the self-capacitance generated by the sensing unit 200 when the sensing unit 200 is touched.
As shown in FIG. 12, it is a structural diagram of a touch screen control wafer according to an embodiment of the present invention. The touch screen control chip 300 includes a charging module 310, a discharging module 320, a detecting module 330, and a control and computing module 340. The charging module 310 applies a high level signal to one of the first electrode 210 and the second electrode 220 of one of the plurality of sensing units during the first charging, and the first electrode 210 and the first electrode The other of the two electrodes 220 is grounded to first charge the self-capacitance generated by one sensing unit 200 when one sensing unit 200 is touched; to sense one of the plurality of sensing units during the second charging process The first electrode 210 and the second electrode 220 of the unit 200 apply a high level signal, or a high level signal is applied to one of the first electrode 210 and the second electrode 220 and the first electrode 210 and the second electrode 220 are The other is disconnected to charge the self capacitor for a second time. The discharge module 320 is configured to ground the first electrode 210 and the second electrode 220 of one sensing unit 200 after the second charging of the self-capacitance by the charging module 310, or to connect the first electrode 210 and the second electrode 220 One of the grounds and the other of the first electrode 210 and the second electrode 220 are disconnected to perform the first discharge of the self-capacitance. The detecting module 330 is configured to detect from the corresponding first electrode 210 or the second electrode 220 each time charging and discharging to obtain a first detection change value between the first charging and the second charging, and correspondingly The first electrode 210 or the second electrode is detected to obtain a second detected change value between the second charge and the first discharge. The control and calculation module 340 is configured to control the charging module 310, the discharging module 320, and the detecting module 330, and calculate the self-capacitance to the first electrode according to the first detection change value and the second detection change value. a ratio of a resistance and a self-capacitance to a second resistance between the second electrodes, and determining a touch position according to a proportional relationship between the first resistance and the second resistance. In the embodiment of the present invention, the control and calculation module 340 can control the charging module 310 to sequentially apply corresponding voltages to the plurality of sensing units in a scanning manner, and can also sequentially perform detection in a scanning manner during detection, or The discharge module 320 can also be controlled to discharge the self-capacitance generated by the touched sensing unit among the plurality of sensing units in sequence.
In the above embodiment of the present invention, although the first charging, the second charging, and the first discharging are taken as an example, in the present invention, as long as there are three different states, by measuring any two different states. The proportional relationship between R1 and R2 can be obtained by the difference in state (i.e., the detected change value). In this embodiment, the three different states are the state after the first charge, the state after the second charge, and the state after the discharge.
In one embodiment of the present invention, the first detected change value and the second detected change value may be one or more of a current detection change value, a self-capacitance detection change value, a level signal detection change value, and a charge change amount.
In one embodiment of the invention, the detection module 330 is a CTS (capacitance detection module).
In an embodiment of the present invention, the control and calculation module 340 is further configured to determine a touch position in the second direction according to the position of the touched sensing unit 200, and according to the touch position and the second direction in the first direction. The upper touch location determines the location of the touch point on the touch screen. Specifically, the control and calculation module 340 determines the touch location in the second direction by a centroid algorithm.
In one embodiment of the present invention, the first direction is the length direction of the sensing unit 200, and the second direction is a direction perpendicular to the length direction of the sensing unit 200, and the sensing units are horizontally arranged in parallel or vertically.
In a preferred embodiment of the invention, a plurality of disjoint sensing units are located in the same layer, thereby effectively reducing manufacturing costs while ensuring detection accuracy.
The invention also proposes a portable electronic device comprising the touch device as described above.
In the embodiment of the present invention, a level signal is applied to the electrodes at both ends of the sensing unit. If the sensing unit is touched, the sensing unit forms a self-capacitance. Therefore, the present invention can charge the self-capacitor by applying a level signal. And determining a touch position on the touch screen according to a proportional relationship between the first resistance and the second resistance. And the detection method of charging the self-capacitance twice by the embodiment of the invention to cancel some unmeasurable physical parameters or reduce the measurement of the physical quantity, thereby effectively improving the detection precision under the premise of ensuring the detection speed.
The embodiment of the invention provides a novel self-capacitance detection method. When the sensing unit is touched, the touch point can divide the sensing unit into two resistors, so that the two resistors can be considered while performing self-capacitance detection. Determine the location of the touch point on the sensing unit. The structure of the embodiment of the invention is simple, and for a sensing unit, charging or discharging can be performed from the first electrode and/or the second electrode thereof, and detecting when charging or discharging, not only can the RC constant be reduced, and the saving can be achieved. Time increases efficiency and also ensures that coordinates are not offset. In addition, the embodiment of the invention can effectively improve the performance-to-noise ratio of the circuit, reduce circuit noise, and improve the linearity of the induction. In addition, since the touched sensing unit is charged during the detection process, a small current is generated therein, which can well eliminate the influence of the Vcom level signal on the self-capacitance generated by the sensing unit in the touch screen, and thus can be eliminated accordingly. The screen mask layer and related processes can further reduce the cost while enhancing the anti-interference ability.
In the description of the present specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like means a specific feature described in connection with the embodiment or example. A structure, material or feature is included in at least one embodiment or example of the invention. In the present specification, the schematic representation of the above terms does not necessarily mean the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.
While the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art Variations, the scope of the invention is defined by the scope of the appended claims and their equivalents.

100, 300’. . . Substrate

110. . . First side

120. . . Second side

200. . . Sensing unit

210. . . First electrode

220. . . Second electrode

230. . . first part

240. . . the second part

250. . . the third part

260. . . fourth part

270. . . the fifth part

280. . . the sixth part

290. . . Part VII

300. . . Touch screen control chip

310. . . Charging module

320. . . Discharge module

330. . . Detection module

340. . . Control and calculation module

1000. . . First groove

2000. . . Second groove

100’, 200’. . . Diamond structure sensing unit

400’. . . Triangle sensing unit

500’. . . electrode

600’. . . finger

A. . . Touch location

C1. . . Self capacitance

GND. . . Ground

R1, R2. . . resistance

S1, S2. . . Contact area

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from
FIG. 1 is a structural diagram of a self-capacitance touch screen commonly seen in the prior art;
Figure 2a is a structural diagram of another self-capacitive touch screen commonly seen in the prior art;
Figure 2b is a schematic diagram of detection of another self-capacitive touch screen that is common in the prior art;
FIG. 3 is a schematic diagram of a detection principle of a touch device according to an embodiment of the present invention; FIG.
4 is a flow chart of a touch detection method according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of a rectangular sensing unit touched according to an embodiment of the present invention; FIG.
6a is a structural diagram of a sensing unit according to an embodiment of the present invention;
Figure 6b is a structural diagram of an induction unit according to an embodiment of the present invention;
FIG. 7a is a structural diagram of a touch screen detecting device according to another embodiment of the present invention;
FIG. 7b is a structural diagram of a touch screen detecting device according to another embodiment of the present invention;
FIG. 8 is a schematic diagram of the sensing unit when it is touched according to an embodiment of the present invention; FIG.
FIG. 9a is a structural diagram of a touch screen detecting device according to still another embodiment of the present invention;
FIG. 9b is a structural diagram of a touch screen detecting device according to still another embodiment of the present invention;
FIG. 10 is a schematic diagram of the sensing unit when it is touched according to an embodiment of the present invention; FIG.
11 is a schematic diagram of a touch device according to an embodiment of the present invention; and FIG. 12 is a structural diagram of a touch screen control wafer according to an embodiment of the present invention.

Claims (21)

A touch detection method for a touch screen, wherein the touch screen comprises a plurality of disjoint sensing units, each of which has a first electrode and a second electrode respectively, the method comprising the steps of:
Applying a high level signal to one of the first electrode and the second electrode of one of the plurality of sensing units, and grounding the other of the first electrode and the second electrode to be in the one The self-capacitance generated by the one sensing unit is first charged when the sensing unit is touched;
Applying a high level signal to the first electrode and the second electrode of one of the plurality of sensing units, or applying a high level signal to one of the first electrode and the second electrode and The other of the first electrode and the second electrode is disconnected to perform a second charging of the self-capacitor;
Detecting from the corresponding first electrode or second electrode to obtain a first detected change value between the first charge and the second charge;
Grounding the first electrode and the second electrode of the one sensing unit, or grounding one of the first electrode and the second electrode and another one of the first electrode and the second electrode One disconnected to discharge the self-capacitor for the first time;
Detecting from the corresponding first or second electrode to obtain a second detected change value between the second charge and the first discharge;
Calculating a ratio of the first resistance between the self-capacitance to the first electrode and the second resistance between the self-capacitance and the second electrode according to the first detection change value and the second detection change value a relationship; and determining a touch position based on a proportional relationship between the first resistance and the second resistance. The touch detection method of the touch screen according to claim 1, wherein the first detection change value and the second detection change value are a current detection change value, a self-capacitance detection change value, and a level signal detection. One or more of a change value and a charge change amount. The touch detection method of the touch screen of claim 1, wherein the sensing unit is rectangular, and the plurality of sensing units are parallel to a first direction of the touch screen, the touch The location is a touch location of the touch object in the first direction. The touch detection method of the touch screen of claim 1, wherein the sensing unit comprises:
a plurality of first portions and a plurality of parallel second portions, wherein adjacent ones of the first portions are connected by the second portion to form a plurality of alternately arranged first and second grooves, wherein The openings of the plurality of first grooves and the plurality of second grooves are opposite in direction. The touch detection method of the touch screen of claim 3 or 4, further comprising:
Determining a touch position in the second direction according to the position of the touched sensing unit; and determining a position of the touch point on the touch screen according to the touch position in the first direction and the touch position in the second direction. The touch detection method of the touch screen of claim 5, wherein the touch position in the second direction is determined by a centroid algorithm. The touch detection method according to any one of claims 3-6, wherein the first direction is a length direction of the sensing unit, and the second direction is perpendicular to the sensing unit. In the direction, the sensing unit levels are arranged in parallel or vertically. The touch detection method of the touch screen of claim 1, wherein the sensing unit comprises:
the third part;
a fourth portion and a fifth portion that are not intersected, one end of the fourth portion is connected to one end of the third portion, and one end of the fifth portion is connected to the other end of the third portion, the fourth portion The other end has the first electrode, and the other end of the fifth portion has the second electrode. The touch detection method of the touch screen of claim 1, wherein the sensing unit comprises:
a sixth part, the first part of the sixth part has the first electrode;
In a seventh portion, one end of the seventh portion is connected to the other end of the sixth portion, and the other end of the seventh portion has the second electrode. A touch device, comprising:
Substrate
a plurality of dissimilar sensing units formed on the substrate, and each of the sensing units has a first electrode and a second electrode respectively;
Touching a screen control chip, the touch screen control chip includes a charging module, a discharging module, a detecting module, and a control and computing module, wherein
The charging module is configured to apply a high level signal to one of the first electrode and the second electrode of one of the plurality of sensing units during the first charging, and the first The other of the electrode and the second electrode is grounded to first charge the self-capacitance generated by the one sensing unit when the one sensing unit is touched; to the plurality of Applying a high level signal to the first electrode and the second electrode of one of the sensing units, or applying a high level signal to one of the first electrode and the second electrode and applying the first electrode and the first electrode The other of the two electrodes is turned off to charge the self-capacitor a second time,
The discharge module is configured to ground the first electrode and the second electrode of the one sensing unit after the charging module performs the second charging of the self-capacitor, or the first electrode and the One of the second electrodes is grounded and the other of the first electrode and the second electrode is disconnected to perform the first discharge of the self-capacitor,
The detecting module is configured to detect from the corresponding first electrode or the second electrode to obtain a first detection change value between the first charging and the second charging, and from the corresponding The first electrode or the second electrode performs detection to obtain a second detection change value between the second charge and the first discharge; and a control and calculation module for the charging module And the discharge module and the detection module perform control, and calculate the first resistance and the self-capacitance between the self-capacitance and the first electrode according to the first detection change value and the second detection change value to the first a proportional relationship between the second resistors between the two electrodes, and determining a touch position according to a proportional relationship between the first resistor and the second resistor. The touch device of claim 10, wherein the first detection change value and the second detection change value are a current detection change value, a self-capacitance detection change value, a level signal detection change value, and One or more of the amount of charge change. The touch device of claim 11, wherein the detection module is a capacitance detection module CTS. The touch device of claim 10, wherein the sensing unit is rectangular, and the plurality of sensing units are parallel to a first direction of the touch screen, and the touch position is The touch position in the first direction. The touch device of claim 10, wherein the sensing unit comprises:
a plurality of first portions and a plurality of parallel second portions, wherein adjacent ones of the first portions are connected by the second portion to form a plurality of alternately arranged first and second grooves, wherein The openings of the plurality of first grooves and the plurality of second grooves are opposite in direction. The touch device of claim 13 or 14, wherein
The control and calculation module is further configured to determine a touch position in the second direction according to the position of the touched sensing unit, and according to the touch position in the first direction and the touch position in the second direction Determine where the touch point is on the touch screen. The touch device of claim 15, wherein the control and calculation module determines the touch position in the second direction by a centroid algorithm. The touch device of claim 15, wherein the first direction is a length direction of the sensing unit, and the second direction is a direction perpendicular to the sensing unit, the sensing The unit levels are set in parallel or vertically. The touch device of claim 10, wherein the plurality of disjoint sensing units are located in the same layer. The touch device of claim 10, wherein the sensing unit comprises:
the third part;
a fourth portion and a fifth portion that are not intersected, one end of the fourth portion is connected to one end of the third portion, and one end of the fifth portion is connected to the other end of the third portion, the fourth portion The other end has the first electrode, and the other end of the fifth portion has the second electrode. The touch device of claim 10, wherein the sensing unit comprises:
a sixth part, the first part of the sixth part has the first electrode;
In a seventh portion, one end of the seventh portion is connected to the other end of the sixth portion, and the other end of the seventh portion has the second electrode. A portable electronic device, comprising the touch device according to any one of claims 10-20.