WO2013013634A1

WO2013013634A1 - Touch detecting method, touch sensitive device and portable electronic apparatus

Info

Publication number: WO2013013634A1
Application number: PCT/CN2012/079220
Authority: WO
Inventors: Zhengang Li; Chen Huang; Yun Yang
Original assignee: Shenzhen Byd Auto R&D Company Limited; Byd Company Limited
Priority date: 2011-07-26
Filing date: 2012-07-26
Publication date: 2013-01-31
Also published as: WO2013013637A1; CN102902427B; CN102902434A; TWM449305U; CN102902433A; CN102902437B; CN102902398A; CN202615359U; CN202795312U; CN102902442A; TWM451595U; CN202548804U; TWM457238U; CN202795311U; WO2013013625A1; CN202795310U; CN102902436A; CN102902399A; TWI486848B; CN102902441B

Abstract

A touch detecting method, a touch sensitive device, and a portable electronic apparatus are provided. The touch detecting method comprises: applying high level signals to the first electrode and/or the second electrode of one induction unit to charge a self capacitor generated by a touch on the one induction unit; grounding the first electrode and the second electrode of the one induction unit respectively; detecting from the first electrode and the second electrode of the one induction unit to obtain a first detecting value and a second detecting value respectively; calculating a ratio between a first resistor between the self capacitor and the first electrode and a second resistor between the self capacitor and the second electrode according to the first detecting value and the second detecting value; and determining a touch position according to the ratio between the first resistor and the second resistor.

Description

TOUCH DETECTING METHOD, TOUCH SENSITIVE DEVICE AND PORTABLE

ELECTRONIC APPARATUS CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and benefits of the following applications:

1) Chinese Patent Application Serial No. 201110211018.2, filed with the State Intellectual Property Office of P. . China on July 26, 2011;

2) Chinese Patent Application Serial No. 201110210959.4, filed with the State Intellectual Property Office of P. R. China on July 26, 2011; and

3) Chinese Patent Application Serial No. 201110459292.1, filed with the State Intellectual Property Office of P. R. China on December 31, 2011.

The entire contents of the above applications are incorporated herein by reference. FIELD

The present disclosure relates to an electronic apparatus design and fabrication field, and more particularly to a touch detecting method, a touch sensitive device, and a portable electronic apparatus. BACKGROUND

Currently, a touch screen has been spread from being applied in a small minority commercial market, such as an ATM (automatic teller machine) in a bank and an industrial control computer quickly to being applied in a mass consumption electronic apparatuses, such as mobile phones, PDA (personal digital assistant), GPS (global positioning system), PMP (such as MP3 or MP4) and panel computers. The touch screen, which has advantages of simple, convenient and humanized touch operations, will be a best human-computer interaction interface and be widely applied in portable apparatus.

A capacitance touch screen is generally divided into two types: self-capacitance type and mutual-capacitance type. Fig. 1 shows a conventional self-capacitance type touch screen. The self-capacitance type touch screen comprises a plurality of induction units 100' and 200' which have a diamond structure and are located in two different layers. A scanning is conducted along an X axis and a Y axis respectively, and if a capacitance variation of a certain intersection point exceeds a predetermined range, the intersection point is made as a touch point. Although a linearity of the self-capacitance type touch screen is good, ghost touch points still appear frequently, and thus it is difficult to realize a multipoint touch. In addition, since a double-layer screen is used, the structure is complicated and the cost is increased. Moreover, under a condition of a slight capacitance variation, the diamond structure may cause a coordinate drift, that is, the diamond structure may be easily affected by an external factor.

Fig. 2a shows another conventional self-capacitance type touch screen. The self-capacitance type touch screen uses a triangular screen structure. The self-capacitance type touch screen comprises: a substrate 300', a plurality of triangular induction units 400' disposed on the substrate 300', and a plurality of electrodes 500' connected with the triangular induction units 400' respectively. Fig. 2b shows a detecting principle of the self-capacitance type touch screen shown in Fig. 2a. As shown in Fig. 2b, an ellipse represents a finger which contacts with two adjacent triangular induction units, SI represents a contact area between the finger and one of the two adjacent triangular induction units, and S2 represents a contact area between the finger and the other. Provided that an origin of coordinate is located at the lower-left corner, an X coordinate may be obtained by X=S2/(S 1+S2)*P, where P is a resolution ratio. When the finger moves rightwards, because S2 does not increase linearly, there is a deviation of the X coordinate. It may be known from the detecting principle that a single end detecting is conducted for the conventional triangular induction unit, that is, the detecting is conducted only from one direction, and coordinates in the two directions are calculated by an algorithm. Although the self-capacitance type touch detecting assembly has a simple structure, an induction capacitance of the screen is not optimized, so that the capacitance variation is small, thus reducing a signal-to-noise ratio. In addition, because each induction unit has a triangular shape, when the figure moves horizontally, the contact area may not increase linearly, thus causing the deviation of the X coordinate and a poor linearity accordingly.

In addition, because the capacitance variation of a conventional capacitance induction unit is small to a femtofarad order of magnitude, a measure circuit needs to satisfy a higher requirement because of an existence of a stray capacitance. Moreover, because the stray capacitance may vary because of many factors, such as temperature, position, and distribution of internal and external electric field, the stray capacitance may interfere with or even bury a tested capacitance signal. In addition, for a single-layer capacitance, because the induction capacitance may be seriously interfered by an influence of a level signal Vcom, which is used for preventing a liquid crystal of a LCD screen from aging. SUMMARY

Embodiments of the present disclosure seek to solve at least one of the problems existing in the prior art to at least some extent, particularly to solve at least one defects of a conventional self capacitance type touch screen.

According to a first aspect of the present disclosure, a touch detecting method for a touch screen is provided. The touch screen comprises a plurality of induction units not intersecting with each other, both ends of each induction unit having a first electrode and a second electrode respectively. The method comprising steps of: applying a high level signal to the first electrode and/or the second electrode of one induction unit to charge a self capacitor generated by a touch on the one induction unit; grounding the first electrode and the second electrode of the one induction unit respectively; detecting from the first electrode and the second electrode of the one induction unit to obtain a first detecting value and a second detecting value respectively; calculating a ratio between a first resistor between the self capacitor and the first electrode of the one induction unit and a second resistor between the self capacitor and the second electrode of the one induction unit according to the first detecting value and the second detecting value; and determining a touch position according to the ratio between the first resistor and the second resistor.

According to a second aspect of the present disclosure, a touch sensitive device is provided. The touch sensitive device comprises: a substrate; a plurality of induction units disposed on the substrate and not intersecting with each other, each induction unit comprising a first electrode and a second electrode; and a control chip, comprising: a charging module connected with the first electrode and the second electrode of each induction unit respectively, and configured to apply a high level signal to the first electrode and/or the second electrode of one induction unit to charge a self capacitor generated by a touch on the one induction unit; a discharging module connected with the first electrode and the second electrode of each induction unit respectively, and configured to ground the first electrode and the second electrode of the one induction unit respectively after the charging module charges the self capacitor; a first detecting module and a second detecting module connected with the first electrode and the second electrode of each induction unit respectively, and configured for detecting from the first electrode and the second electrode of the one induction unit to obtain a first detecting value and a second detecting value respectively when the discharging module discharges the self capacitor; and a control and calculating module configured for controlling the charging module, the discharging module, the first detecting module and the second detecting module; for calculating a ratio between a first resistor between the self capacitor and the first electrode of the one induction unit and a second resistor between the self capacitor and the second electrode of the one induction unit according to the first detecting value and the second detecting value; and for determining a touch position according to the ratio between the first resistor and the second resistor.

According to a third aspect of the present disclosure, a portable electronic apparatus comprising the touch sensitive device according to the second aspect of the present disclosure is provided.

Detections are performed at two ends of the induction unit in the touch sensitive device according to the embodiments of the present disclosure. The two ends of the induction unit have electrodes respectively and each electrode is connected with a corresponding pin of the control chip. When the touch detection is performed, the touch position may be determined on the induction unit.

More importantly, the touch position is determined according to the ratio between the first resistor and the second resistor. Compared with the conventional diamond or triangular designs, the self capacitor doesn't need to be calculated when determining the touch position and the magnitude of the self capacitor will not influence the precision of the touch position, and thus the detecting precision and the linearity may be improved.

According to an embodiment of the present discourse, level signals are applied to electrodes of the induction unit at both ends of the induction unit. If the induction unit is touched, a self capacitor may be generated by the touch of a touch object (for example, a finger) on the induction unit touched. Therefore, the self capacitor may be charged by the applied level signals, and a touch position may be determined according to a ratio between the first resistor and the second resistor. Moreover, with the touch detecting method according to an embodiment of the present discourse, by first applying a high level signal to the first electrode and/or the second electrode to charge the self capacitor, and then grounding the first electrode and the second electrode respectively to discharge the self capacitor, the touch position on the touch screen may be detected precisely, thus effectively improving a detecting precision while guaranteeing a detecting speed.

The touch sensitive device according to an embodiment of the present disclosure adopts a novel self capacitor detecting method. When the induction unit is touched, a self capacitor is generated at the touch position on the touch sensitive device, and the touch position may divide the induction unit into two resistors. When the self capacitor detection is performed, the touch position on the induction unit may be determined by taking into account the two resistors. The touch sensitive device according to an embodiment of the present disclosure is simple in structure. Moreover, for one induction unit, the detection may be performed during the charging or discharging, which may not only reduce a C constant, save time and improve an efficiency, but also ensure that a coordinate may not drift. In addition, with the touch sensitive device according to an embodiment of the present disclosure, the signal-to-noise ratio of a circuit may be effectively increased, the noise of the circuit may be reduced, and a linearity of an induction may be improved. Furthermore, because the induction unit touched is charged during the detection, small current may be generated in the induction unit touched, and an influence of a level signal Vcom on the self capacitor generated by a touch on an induction unit on the touch screen may be eliminated by the small current. Accordingly, a screen shielding layer and related procedures thereof may be eliminated, thus further reducing a cost while enhancing an anti-interference capability.

Additional aspects and advantages of the embodiments of the present disclosure will be given in part in the following descriptions, become apparent in part from the following descriptions, or be learned from the practice of the embodiments of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects and advantages of the disclosure will become apparent and more readily appreciated from the following descriptions taken in conjunction with the drawings in which:

Fig. 1 is a schematic structural view of a conventional self capacitor type touch screen;

Fig. 2a is a schematic structural view of another conventional self capacitor type touch screen;

Fig. 2b is a diagram showing a detecting principle of the another conventional self capacitor type touch screen shown in Fig. 2a;

Fig. 3 is a diagram showing a detecting principle of a touch sensitive device according to an embodiment of the present disclosure;

Fig. 4 is a flow chart of a touch detecting method according to an embodiment of the present disclosure;

Fig. 5 is a schematic structural view of an induction unit according to an embodiment of the present disclosure;

Fig. 6a is a schematic structural view of an induction unit according to an embodiment of the present disclosure;

Fig. 6b is a schematic structural view of an induction unit according to another embodiment of the present disclosure;

Fig. 7a is a schematic structural view of an induction unit according to an embodiment of the present disclosure;

Fig. 7b is a schematic structural view of an induction unit according to another embodiment of the present disclosure;

Fig. 8 is a schematic view showing that an induction unit is touched according to an embodiment of the present disclosure;

Fig. 9a is a schematic structural view of an induction unit according to still another embodiment of the present disclosure;

Fig. 9b is a schematic structural view of an induction unit according to yet another embodiment of the present disclosure;

Fig. 10 is a schematic view showing that an induction unit is touched according to an embodiment of the present disclosure;

Fig. 11 is a schematic view of a touch sensitive device according to an embodiment of the present disclosure; and

Fig. 12 is a block diagram of a control chip according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

Reference will be made in detail to embodiments of the present disclosure. The embodiments described herein with reference to drawings are explanatory, illustrative, and used to generally understand the present disclosure. The embodiments shall not be construed to limit the present disclosure. The same or similar elements and the elements having same or similar functions are denoted by like reference numerals throughout the descriptions.

A touch sensitive device according to an embodiment of the present disclosure adopts a novel self capacitor detecting method. When an induction unit is touched, a self capacitor is generated at a touch position on the touch sensitive device and the touch position may divide the induction unit into two resistors. When the self capacitor detection is performed, the touch position on the induction unit may be determined by taking into account the two resistors. Fig. 3 is a diagram showing a detecting principle of a touch sensitive device according to an embodiment of the present disclosure. When a finger touches the induction unit, the induction unit is divided into a first resistor l and a second resistor R2 and a ratio between Rl and R2 is related to the touch position. For example, as shown in Fig. 3, when the touch position is closer to a first electrode 210, the first resistor Rl is comparatively small and the second resistor R2 is comparatively large; in contrast, when the touch position is closer to a second electrode 220, the first resistor Rl is comparatively large and the second resistor R2 is comparatively small. Therefore, by detecting the first resistor Rl and the second resistor R2, the touch position on the induction unit 2 may be determined.

In the embodiments of the present disclosure, the first resistor Rl and the second resistor R2 may be determined in various ways, for example, by detecting one or more of a current detecting value, a self capacitance detecting value, a level signal detecting value, a charge variation, the first resistor Rl and the second resistor R2 may be obtained based on the above detecting values.

It should be noted that in the embodiments of the present disclosure, a function of the first electrode 210 and the second electrode 220 are the same and the first electrode 210 and the second electrode 220 are interchangeable. Therefore, in the above embodiments, the detection may be performed from the first electrode 210 or from the second electrode 220, as long as there is a current flowing through the first resistor Rl and the second resistor R2 during the charging, discharging and detection.

In the embodiments of the present disclosure, corresponding voltages may be applied to the plurality of induction units sequentially and the detection may be performed for the plurality of induction units sequentially.

Fig. 4 is a flow chart of a touch detecting method according to an embodiment of the present disclosure. The touch detecting method will be described with reference to the principle view of Fig. 3. The touch detecting method comprises the following steps. In step S401, a high level signal is applied to the first electrode and/or the second electrode of one induction unit to charge a self capacitor generated by a touch on the one induction unit. In one embodiment, the high level signals applied to the first electrode and the second electrode may be identical or different.

If the induction unit is touched by a finger or other objects at this time, the self capacitor CI will be generated in the induction unit (referring to Fig. 3). The self capacitor CI may be charged by the applied high level signal. In addition, in the embodiments, by charging the self capacitor CI, the detecting precision of the self capacitor CI may be improved.

In one embodiment, if the induction unit is not touched, an existence of the self capacitor will not be detected, and thus it is determined that the induction unit is not touched.

In one embodiment, the high level signal is applied to the first electrode and the second electrode is disconnected; or the high level signal is applied to the second electrode and the first electrode is disconnected; or the high level signals are applied to both the first electrode and the second electrode. In one embodiment, the high level signals may be applied to the first electrode and the second electrode simultaneously or separately. It should be noted that the amplitude of the high level signals applied to the first electrode and the second electrode may be equal or unequal. In one embodiment, the amplitude of the high level signals applied to the first electrode and the second electrode is equal, such as Vcc.

Similarly, in one embodiment, corresponding voltages may be applied to the plurality of induction units sequentially, and the detection may be performed for the plurality of induction units sequentially.

In step S402, the first electrode and the second electrode of the one induction unit are grounded respectively to discharge the self capacitor.

In step S403, a first detecting value and a second detecting value are obtained by detecting from the first electrode and the second electrode of the one induction unit respectively. In the following description, charge variations AQl and AQ2 are taken as the first detecting value and the second detecting value respectively. However, other detecting values, such as level signals or currents, which may reflect the relation between the first resistor l and the second resistor R2, may also be adopted. In the embodiment of the present disclosure, the detections from the first electrode and from the second electrode may be performed simultaneously.

It should be noted that, in this embodiment, two capacitance detecting modules are needed to detect from both ends of the induction unit.

In step S404, a ratio between a first resistor between the self capacitor and the first electrode of the one induction unit and a second resistor between the self capacitor and the second electrode of the one induction unit is calculated according to the first detecting value and the second detecting value, and a touch position of a touch object (for example, a finger) is determined according to the ratio between the first resistor and the second resistor. In one embodiment, the ratio between the first resistor and the second resistor may be calculated according to the charge variations AQ l and AQ2 which are obtained by detecting from the first electrode and the second electrode respectively. Since a shape of each induction unit has a regular linearity, an X coordinate of the touch position may be calculated, and finally a position of the self capacitor CI may be obtained. A coordinate of the self capacitor CI on the induction unit is AQ2/(AQ1+AQ2).

In one embodiment, if the induction unit has a U shape or an L shape, the touch position on a touch screen may be determined according to the ratio between the first resistor Rl and the second resistor R2, which will be described in details with reference to examples.

In another embodiment, if the induction unit has a substantially rectangular shape or a snakelike shape (whose overall shape is substantially equivalent to a rectangular shape), only the touch position on the touch screen in a first direction, which may be a length direction of the induction unit (for example, a horizontal direction of the touch screen), may be determined in step S404. If the induction unit has a rectangular shape or a snakelike shape (whose overall shape is substantially equivalent to a rectangular shape), the touch position in the second direction needs to be determined according to a position of the induction unit. In one embodiment, the first direction is the length direction of the induction unit, the second direction is the direction vertical to the induction unit, and the induction unit is disposed horizontally or vertically.

In the embodiments of the present disclosure, the capacitance detecting module may be any known capacitance detecting module in the art. In an embodiment, if two capacitance detecting modules are used, they may share many means, so that the overall power consumption of a control chip may not be increased.

In one embodiment, the induction units may have various shapes. Preferably, a plurality of induction units not intersecting with each other are disposed in a same layer, thus greatly lowering a cost while guaranteeing a detection precision. Fig. 5 is a schematic view of an induction unit according to an embodiment of the present disclosure. As shown in Fig. 5, the touch screen comprises a plurality of induction units 200 disposed on a substrate 100 and not intersecting with each other, both ends of each induction unit 200 having a first electrode 210 and a second electrode 220 respectively. Each induction unit 200 has a rectangular shape, and is parallel to the first direction of the touch screen, and thus the touch position is a touch position in the first direction.

Fig. 6a is a schematic view of an induction unit showing an induction unit according to an embodiment of the present disclosure. As shown in Fig. 6a, the induction unit 200 comprises: a plurality of first parts 230 and a plurality of parallel second parts 240. Every two adjacent first parts 230 are connected via one second part 240 to form a plurality of first trenches 1000 and a plurality of second trenches 2000 alternating with each other one by one. An opening direction of the plurality of first trenches 1000 is opposite to an opening direction of the plurality of second trenches 2000, and the touch position is a touch position in the first direction. In one embodiment, each second part 240 is arranged in the first direction. The plurality of first parts 230 may be parallel with each other, or may not be parallel with each other. In one embodiment, each second part 240 may have a rectangular shape, and each first part 230 may have a rectangular shape or other various shapes. In the embodiment, an impedance of a resistor may be increased by the first part 230, thus increasing an impedance of the induction unit 200. Therefore, detections of the first resistor and the second resistor may be easier, thus further improving the detection precision. In the embodiment, preferably, distances between every two adjacent second parts 240 are identical so as to increase the impedance of the induction unit 200 uniformly, thus improving the detection precision. In one embodiment, the first direction is the length direction of each induction unit 200, and the second direction is the direction vertical to each induction unit 200. Specifically, each induction unit 200 is disposed horizontally or vertically.

In one embodiment, a size of each induction unit 200 in the length direction thereof is substantially identical with a size of the substrate 100. Therefore, a structure complexity of a touch sensitive device may be reduced, and the touch sensitive device is easy to manufacture, thus reducing a manufacturing cost.

In one embodiment, the first electrode 210 and the second electrode 220 are connected with two of the plurality of first parts 230 respectively, as shown in Fig. 6a. In another embodiment, the first electrode 210 and the second electrode 220 are connected with two of the plurality of second parts 240 respectively, as shown in Fig. 6b.

Moreover, in one embodiment, each second part 240 is vertical to each first part 230, that is, an angle between each second part 240 and each first part 230 is 90 degree in this embodiment, but certainly, the angle is not limited to 90 degree. As shown in Fig. 6a, a plurality of first parts 230 are connected end to end via a plurality of second parts 240, and the first electrode 210 and the second electrode 220 of each induction unit 200 are connected with two first parts 230 at two ends of the each induction unit 200. In terms of an overall structure, the induction unit 200 has a rectangular shape with a large length-to-width ratio. It should be noted that, although each induction unit 200 is disposed along an X axis in Fig. 6a, those skilled in the art should understand that each induction unit 200 may be disposed along a Y axis. With the touch detecting assembly comprising the above induction unit according to an embodiment of the present disclosure, a noise may be effectively reduced and a linearity of an induction may be improved.

Fig. 7a is a schematic structural view of an induction unit according to an embodiment of the present disclosure. As shown in Fig. 7a, in this embodiment, each induction unit 200 has a U shape, and lengths of the plurality of induction units 200 are different from each other, and the plurality of induction units 200 are partly embedded one by one. Each induction unit 200 comprises: a third part 250, a fourth part 260, and a fifth part 270 not intersecting with the fourth part 260. In one embodiment, each third part 250 is parallel with a first side 110 of the substrate 100, and each fourth part 260 and each fifth part 270 are parallel with a second side 120 of the substrate 100 respectively. One end of the fourth part 260 is connected with one end of the third part 250, one end of the fifth part 270 is connected with the other end of the third part 250, the other end of the fourth part 260 is connected with the first electrode 210, and the other end of the fifth part 270 is connected with the second electrode 220. Each first electrode 210 and each second electrode 220 are connected with corresponding pins of the control chip 300.

In the embodiment, "partly embedded one by one" means an outer induction unit partly surrounds an inner induction unit, for example, as shown in Fig. 7a, so as to achieve a comparatively large contact area while guaranteeing the detecting precision, reducing computing complexity and improving a responding speed of the touch screen. Certainly, those skilled in the art may adopt other embedding methods to arrange the induction units according to principles shown in Fig. 7a. In one embodiment, the third parts 250 of the plurality of induction units 200 are parallel with each other, the fourth parts 260 of the plurality of induction units 200 are parallel with each other, and the fifth parts 270 of the plurality of induction units 200 are parallel with each other. In one embodiment, at least one of the third part 250, the fourth part 260 and the fifth part 270 of each induction unit 200 has a rectangular shape. Preferably, all of the third part 250, the fourth part 260 and the fifth part 270 of each induction unit 200 have a rectangular shape. In this embodiment, because of the rectangular shape, when the finger moves horizontally or vertically, the linearity may be good. In addition, distances between every two adjacent rectangular structures are identical so as to improve a computing speed.

In one embodiment, lengths of the fourth part 260 and the fifth part 270 of each induction unit 200 are identical.

In one embodiment, the substrate 100 has a rectangular shape, the first side 110 and the second side 120 are vertical to each other, the fourth part 260 and the third part 250 of each induction unit 200 are vertical to each other, and the fifth part 270 and the third part 250 of each induction unit 200 are vertical to each other.

In one embodiment, distances between the third parts 250 of every two adjacent induction units 200 are identical, distances between the fourth parts 260 of every two adjacent induction units 200 are identical, and distances between the fifth parts 270 of every two adjacent induction units 200 are identical. Therefore, the plurality of induction units 200 may be used to uniformly divide the first side 110 and the second side 120 of the substrate 100 to improve the computing speed. Of course, in other embodiments, distances between the third parts 250 of every two adjacent induction units 200 may be different, or distances between the fourth parts 260 of every two adjacent induction units 200 may be different, as shown in Fig. 7b. For example, since a user usually touches a central part of the touch screen, a distance between the induction units 200 at the central part of the touch screen may be reduced to improve the detecting precision at the central part of the touch screen.

In one embodiment, each induction unit 200 is symmetrical with respect to a central axis Y of the substrate 100, as shown in Fig. 7a, and the central axis Y of the substrate 100 is vertical to the third part 250 of each induction unit 200, thus improving a precision.

As shown in Fig. 7a, in this embodiment, both the first electrode 210 and the second electrode

220 of each induction unit 200 are located at the first side 110 of the substrate 100. In this embodiment, after a touch position on an induction unit is detected, a touch position on the touch screen may be obtained. It should be noted that the substantially U-shaped induction units 200 shown in Fig. 7a are only examples of the induction unit, which may achieve a comparatively larger contact area. However, there may be variations to the embodiments shown in Fig. 7a. For example, the fourth part 260 and the fifth part 270 of each induction unit 200 may not be parallel to each other.

With the substantial U-shaped induction unit 200 according to the above embodiment of the present disclosure, a structure complexity of a device may be reduced and the device is easy to manufacture. All the electrodes are located at one side, which are easy to manufacture, thus reducing a manufacturing cost.

Fig. 8 is a schematic view showing that an induction unit of a touch screen is touched according to an embodiment of the present disclosure. As shown in Fig. 8, the touch position A is near the second electrode 220. Assume the length of the induction unit 200 has a length of ten units by which the induction unit 200 is uniformly divided into 10 parts. The third part 250 has a length of 4 units, and each of the fourth part 260 and the fifth part 270 has a length of 3 units. After detection, it is obtained that a ratio between the first resistor l and the second resistor R2 is 4: 1, that is, a distance from the first electrode 210 to the touch position (reflected by the first resistor) accounts for 80% of the whole length of the induction unit 200. In other words, the touch point is at a position whose distance to the first electrode 210 is 8 units, or the touch point is at a position whose distance to the second electrode 220 is 2 units. Since the touch position will move accordingly when the finger moves, a moving track of the finger may be judged according to a movement of the touch position, thus judging an input instruction of a user.

From the examples shown in Fig. 8, it is clear that a computing method of the touch screen according to an embodiment of the present disclosure is simple, which may improve the responding speed of the detection of the touch screen. In some embodiments, a finger or other objects will touch a plurality of induction units 200. At this time, a touch position in each of the plurality of induction units 200 touched may be obtained first, and then a final touch position on the touch screen may be calculated by averaging.

Fig. 9a is a schematic structural view of an induction unit according to an embodiment of the present disclosure. In this embodiment, lengths of the plurality of induction units 200 increase gradually, and each induction unit 200 comprises a sixth part 280 and a seventh part 290. One end of the sixth part 280 comprises the first electrode 210, one end of the seventh part 290 is connected with the other end of the sixth part 280, and the other end of the seventh part 290 comprises the second electrode 220.

Specifically, each sixth part 280 is parallel with the first side 110 of the substrate 100, each seventh part 290 is parallel with the second side 120 of the substrate 100, and the first side 110 and the second side 120 are adjacent to each other. Each first electrode 210 and each second electrode 220 are connected with corresponding pins of the control chip 300.

In one embodiment, the sixth parts 280 of the plurality of induction units 200 are parallel with each other, and the seventh parts 290 of the plurality of induction units 200 are parallel with each other, which may effectively increase the coverage rate of the induction units 200 on the touch screen. In one embodiment, at least one of the sixth part 280 and the seventh part 290 of each induction unit 200 has a rectangular shape. Preferably, both the sixth part 280 and the seventh part 290 of each induction unit 200 have a rectangular shape. In this embodiment, because of the rectangular shape, when the finger moves horizontally or vertically, the linearity may be good. In addition, distances between every two adjacent rectangular structures are identical so as to improve the computing speed.

Detections are performed at two ends of each induction unit in the touch sensitive device according to an embodiment of the present disclosure. The two ends of the induction unit have electrodes respectively and each electrode is connected with a corresponding pin of the control chip. When the touch detection is performed, the touch position may be determined on the induction unit.

More importantly, the touch position is determined according to the ratio between the first resistor Rl and the second resistor R2. Compared with the conventional diamond or triangular designs, the self capacitor doesn't need to be calculated when determining the touch position and the magnitude of the self capacitor will not influence the precision of the touch position, and thus the self capacitor detection doesn't need to be as precise as before and the detecting precision and the linearity may be improved. In addition, since any one of the sixth part 280 and the seventh part 290 may have a regular rectangular shape, compared with the conventional diamond or triangular designs, the linearity may be further improved.

In one embodiment, lengths of the sixth part 280 and the seventh part 290 of each induction unit 200 are identical so as to improve the computing speed. In one embodiment, the substrate 100 has a rectangular shape, and the first side 110 and the second side 120 are vertical to each other, which may allow a more regular design for the induction unit. For example, the sixth part 280 and the seventh part 290 of each induction unit 200 are vertical to each other, thus increasing a coverage rate of the induction units on a touch screen and improving a linearity of the detection.

In one embodiment, distances between every two adjacent induction units 200 are identical so that the plurality of induction units 200 may be used to uniformly divide the first side 110 and the second side 120 of the substrate 100 to improve a computing speed. Of course, in other embodiments, distances between every two adjacent induction units 200 may be different, as shown in Fig. 9b. For example, since a user usually touches a central part of the touch screen, a distance between the induction units 200 at the central part of the touch screen may be reduced to improve the detecting precision at the central part of the touch screen.

As shown in Fig. 9a, in this embodiment, the first electrode 210 of each induction unit 200 is located at the first side 110 of the substrate 100, the second electrode 220 of each induction unit 200 is located at the second side 120 of the substrate 100, and the first side 110 and the second side 120 are vertical to each other. In this embodiment, after a touch position on an induction unit is detected, the touch position on the touch screen may be obtained.

Fig. 10 is a schematic view showing that an induction unit of a touch screen is touched according to an embodiment of the present disclosure. As shown in Fig. 10, the touch position A is near the second electrode 220. Assume the length of the induction unit 200 has a length of 10 units by which the induction unit 200 is uniformly divided into 10 parts. The sixth part 280 has a length of 5 units, and the seventh part 290 has a length of 5 units. After detection, it is obtained that a ratio between the first resistor and the second resistor is 9: 1, that is, a distance from the first electrode 210 to the touch position (reflected by the first resistor) accounts for 90% of the whole length of the induction unit 200. In other words, the touch point is at a position whose distance to the first electrode 210 is 9 units, or the touch point is at a position whose distance to the second electrode 220 is 1 unit.

From the examples shown in Fig. 10, it is clear that a computing method according to an embodiment of the present disclosure is simple, which may improve the responding speed of the detection of the touch screen.

In one embodiment, the plurality of induction units 200 are located in a same layer. Therefore, only one ITO layer is required, thus reducing a manufacturing cost largely while guaranteeing a precision.

Detections are performed at two ends of each induction unit in the touch detecting assembly according to an embodiment of the present disclosure. The two ends of the induction unit have electrodes respectively and each electrode is connected with a corresponding pin of the control chip. When the touch detection is performed, the touch position may be determined on the induction unit.

In summary, according to an embodiment of the present discourse, level signals are applied to electrodes of the induction unit at both ends of the induction unit. A self capacitor may be generated when the induction unit is touched. Therefore, the self capacitor may be charged by the applied level signals and a touch position may be determined according to a ratio between the first resistor and the second resistor. For example, in one embodiment, the ratio between the first resistor and the second resistor is calculated by a ratio between a first detecting value and a second detecting value obtained by detecting from the first electrode and/or the second electrode when charging/discharging the self capacitor. Therefore, the first detecting value and the second detecting value may be detected from the first electrode and/or the second electrode when charging or discharging the self capacitor. Thus, the first detecting value and the second detecting value may reflect the touch position on the induction unit, and the touch position on the induction unit may be further determined.

For the induction units shown in Fig. 5 and Fig. 6, after the touch position in the first direction is determined, the touch position in the second direction needs to be further determined according to the position of the induction unit touched. In this embodiment, with reference to Fig. 5 and Fig. 6, if the first detecting value or the second detecting value of one induction unit is detected to be larger than a predetermined threshold, it is determined that the induction unit is touched. Assume that a second induction unit, of which a coordinate of the Y axis is M, is touched, the touch position in the second direction is the coordinate M of the second induction unit. Then, the position on the touch screen may be determined according to the position in the first direction and the position in the second direction.

Specifically, the touch position in the second direction may be calculated according to the centroid algorithm, which will be briefly discussed below.

In slide bar and touch pad applications, a position of a finger (or other capacitive objects) may be determined according to the induction units touched. A contact area of a finger on the slide bar or touch pad is usually larger than any induction unit. In order to use a center to calculate the touched position, it is effective to scan this array to verify the touch position, and a requirement for the number of adjacent induction units is that the signal is larger than a predetermined touch threshold. After the strongest signal has been found, the strongest signal and those adjacent signals larger than the touch threshold are used to calculate the center.

=— n, iii, (i-l ) +n_; !i + n 111 (i+1 )

Cent

η_{; ι}+η_; + n_i+1

N_Cent is an identifier of a central induction unit, n is the number of the touched induction units, i is a sequence of the touched induction unit and i is larger than or equal to 2.

For example, when the finger touches the first path, the capacitance change amount of the first path is yl, the capacitance change amount of the second path is y2 and the capacitance change amount of the third path is y3, among which y2 is the largest. Then, the coordinate Y may be calculated as:

yl * 1 + yl * 2 + yl * 3

Y=

yl + yl + y3

Fig. 11 is a schematic view of a touch sensitive device according to an embodiment of the present disclosure. The touch sensitive device comprises a touch detecting assembly constituted by the substrate 100 and the plurality of induction units 200 disposed on the substrate 100 and not intersecting with each other, and a control chip 400. The first electrodes 210 and the second electrodes 220 of the plurality of induction units 200 are connected with corresponding pins of a control chip 400. The control chip 400 is configured to apply a level signal to each first electrode 210 and/or each second electrode 220 to charge a self capacitor generated by a touch on an induction unit 200.

Fig. 12 is a block diagram of a control chip according to an embodiment of the present disclosure. As shown in Fig. 12, the control chip 300 comprises: a charging module 310, a discharging module 320, a first detecting module 330, a second detecting module 340 and a control and calculating module 350.

The charging module 310 is connected with the first electrode 210 and the second electrode 220 of each induction unit 200 respectively, and configured for applying a high level signal to the first electrode 210 and/or the second electrode 220 of one induction unit 200 to charge a self capacitor generated by a touch on the one induction unit 200

The discharging module 320 is connected with the first electrode 210 and the second electrode 220 of each induction unit 200 respectively, and configured for grounding the first electrode 210 and the second electrode 220 of the one induction unit 200 to discharge the self capacitor after the charging module 310 charges the self capacitor. The first detecting module 330 and the second detecting module 340 are connected with the first electrode 210 and the second electrode 220 of each induction unit 200 respectively, and configured for detecting from the first electrode 210 and the second electrode 220 of the one induction unit 200 to obtain a first detecting value and a second detecting value respectively when the discharging module 320 discharges the self capacitor.

The control and calculating module 350 is configured for controlling the charging module

310, the discharging module 320, the first detecting module 330 and the second detecting module 340, for calculating the ratio between a first resistor Rl between the self capacitor and the first electrode 210 of the one induction unit 200 and a second resistor R2 between the self capacitor and the second electrode 220 of the one induction unit 200 according to the first detecting value and the second detecting value, and for determining a touch position according to the ratio between the first resistor Rl and the second resistor R2. In some embodiments, the control and calculating module 350 may control the charging module 310 to apply corresponding voltages to the plurality of induction units in a scanning mode sequentially, and the detection may be performed for the plurality of induction units in a scanning mode sequentially. In other embodiments, the control and calculating module 350 may control the discharging module 320 to discharge the self capacitors generated by the touch on the induction units touched of the plurality of induction units in a scanning mode sequentially.

In one embodiment, each of the first detecting value and the second detecting value is any one of a current detecting value, a self capacitance detecting value, a level signal detecting value, a charge variation and a combination thereof.

In one embodiment, each of the first detecting module 330 and the second detecting module 340 is a capacitance detecting module.

In one embodiment, the control and calculating module 350 is further configured for determining the touch position in the second direction according to the position of the induction unit touched, and for determining the final touch position on the touch screen according to the touch position in the first direction and the touch position in the second direction. Specifically, the touch position in the second direction may be determined by the control and calculating module 350 by a centroid algorithm.

In one embodiment, the first direction is the length direction of each induction unit 200, and the second direction is the direction vertical to each induction unit 200. Specifically, each induction unit 200 is disposed horizontally or vertically.

In one embodiment, the plurality of induction units 200 are located in a same layer, thus effectively reducing a manufacturing cost while guaranteeing a precision.

According to an embodiment of the present disclosure, a portable electronic apparatus comprising the above-mentioned touch sensitive device is provided.

According to an embodiment of the present discourse, level signals are applied to electrodes of the induction unit at both ends of the induction unit. If the induction unit is touched, a self capacitor may be generated by the touch on the induction unit touched. Therefore, the self capacitor may be charged by the applied level signals, and a touch position may be determined according to a ratio between the first resistor and the second resistor. Moreover, with the touch detecting method according to an embodiment of the present discourse, by first applying a high level signal to the first electrode and/or the second electrode to charge the self capacitor, and then grounding the first electrode and the second electrode respectively to discharge the self capacitor, the touch position on the touch screen may be detected precisely, thus effectively improving the detecting precision while guaranteeing a detecting speed.

The touch sensitive device according to an embodiment of the present disclosure adopts a novel self capacitor detecting method. When the induction unit is touched, a self capacitor is generated at the touch position on the touch sensitive device, and the touch position may divide the induction unit into two resistors. When the self capacitor detection is performed, the touch position on the induction unit may be determined by taking into account the two resistors. The touch sensitive device according to an embodiment of the present disclosure is simple in structure. Moreover, for one induction unit, the detection may be performed during the charging or discharging, which may not only reduce a RC constant, save time and improve an efficiency, but also ensure that a coordinate may not drift. In addition, with the touch sensitive device according to an embodiment of the present disclosure, the signal-to-noise ratio of a circuit may be effectively increased, the noise of the circuit may be reduced, and a linearity of an induction may be improved. Furthermore, because the induction unit touched is charged during the detection, small current may be generated in the induction unit touched, and an influence of a level signal Vcom on the self capacitor generated by a touch on an induction unit on the touch screen may be eliminated by the small current. Accordingly, a screen shielding layer and related procedures thereof may be eliminated, thus further reducing a cost while enhancing an anti-interference capability.

Reference throughout this specification to "an embodiment," "some embodiments," "one embodiment", "another example," "an example," "a specific example," or "some examples," means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Thus, the appearances of the phrases such as "in some embodiments," "in one embodiment", "in an embodiment", "in another example," "in an example," "in a specific example," or "in some examples," in various places throughout this specification are not necessarily referring to the same embodiment or example of the present disclosure. Furthermore, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

Although explanatory embodiments have been shown and described, it would be appreciated by those skilled in the art that changes, alternatives, and modifications may be made in the embodiments without departing from spirit and principles of the disclosure. Such changes, alternatives, and modifications all fall into the scope of the claims and their equivalents.

Claims

WHAT IS CLAIMED IS:

1. A touch detecting method for a touch screen, the touch screen comprising a plurality of induction units not intersecting with each other, both ends of each induction unit having a first electrode and a second electrode respectively, the method comprising steps of:

applying a high level signal to the first electrode and/or the second electrode of one induction unit to charge a self capacitor generated by a touch on the one induction unit;

grounding the first electrode and the second electrode of the one induction unit respectively; detecting from the first electrode and the second electrode of the one induction unit to obtain a first detecting value and a second detecting value respectively;

calculating a ratio between a first resistor between the self capacitor and the first electrode of the one induction unit and a second resistor between the self capacitor and the second electrode of the one induction unit according to the first detecting value and the second detecting value; and determining a touch position according to the ratio between the first resistor and the second resistor.

2. The touch detecting method according to claim 1, wherein each of the first detecting value and the second detecting value is any one of a current detecting value, a self capacitance detecting value, a level signal detecting value, a charge variation and a combination thereof.

3. The touch detecting method according to claim 1, wherein each induction unit has a rectangular shape and is parallel to a first direction of the touch screen, and the touch position is a touch position in the first direction.

4. The touch detecting method according to claim 1, wherein each induction unit comprises: a plurality of first parts; and

a plurality of parallel second parts,

wherein every two adjacent first parts are connected via one second part to form a plurality of first trenches and a plurality of second trenches alternating with each other one by one, an opening direction of the plurality of first trenches is opposite to an opening direction of the plurality of second trenches, and the touch position is a touch position in a first direction.

5. The touch detecting method according to claim 3 or 4, further comprising:

determining a touch position in a second direction according to the position of the one induction unit touched; and determining a touch position on the touch screen according to the touch position in the first direction and the touch position in the second direction.

6. The touch detecting method according to claim 5, wherein the touch position in the second direction is determined by a centroid algorithm.

7. The touch detecting method according to any one of claims 3-6, wherein the first direction is a length direction of each induction unit, the second direction is a direction vertical to each induction unit, and each induction unit is disposed horizontally or vertically.

8. The touch detecting method according to claim 1, wherein each induction unit comprises: a third part;

a fourth part;

a fifth part not intersecting with the fourth part;

the first electrode; and

the second electrode,

wherein one end of the fourth part is connected with one end of the third part, one end of the fifth part is connected with the other end of the third part, the other end of the fourth part is connected with the first electrode, and the other end of the fifth part is connected with the second electrode.

9. The touch detecting method according to claim 1, wherein each induction unit comprises: a sixth part;

a seventh part;

the first electrode; and

the second electrode,

wherein one end of the seventh part is connected with one end of the sixth part, the other end of the seventh part is connected with the second electrode, and the other end of the sixth part is connected with the first electrode.

10. A touch sensitive device, comprising:

a substrate;

a plurality of induction units disposed on the substrate and not intersecting with each other, each induction unit comprising a first electrode and a second electrode; and

a control chip, comprising:

a charging module connected with the first electrode and the second electrode of each induction unit respectively, and configured to apply a high level signal to the first electrode and/or the second electrode of one induction unit to charge a self capacitor generated by a touch on the one induction unit;

a discharging module connected with the first electrode and the second electrode of each induction unit respectively, and configured to ground the first electrode and the second electrode of the one induction unit respectively after the charging module charges the self capacitor;

a first detecting module and a second detecting module connected with the first electrode and the second electrode of each induction unit respectively, and configured to detect from the first electrode and the second electrode of the one induction unit to obtain a first detecting value and a second detecting value respectively when the discharging module discharges the self capacitor; and

a control and calculating module configured to control the charging module, the discharging module, the first detecting module and the second detecting module; to calculate a ratio between a first resistor between the self capacitor and the first electrode of the one induction unit and a second resistor between the self capacitor and the second electrode of the one induction unit according to the first detecting value and the second detecting value; and to determine a touch position according to the ratio between the first resistor and the second resistor.

11. The touch sensitive device according to claim 10, wherein each of the first detecting value and the second detecting value is any one of a current detecting value, a self capacitance detecting value, a level signal detecting value, a charge variation and a combination thereof.

12. The touch sensitive device according to claim 11, wherein each of the first detecting module and the second detecting module is a capacitance detecting module.

13. The touch sensitive device according to claim 11, wherein each induction unit has a rectangular shape and is parallel to a first direction of the touch screen, and the touch position is a touch position in the first direction.

14. The touch sensitive device according to claim 11, wherein each induction unit comprises: a plurality of first parts; and

a plurality of parallel second parts,

wherein every two adjacent first parts are connected via one second part to form a plurality of first trenches and a plurality of second trenches alternating with each other one by one, and an opening direction of the plurality of first trenches is opposite to an opening direction of the plurality of second trenches.

15. The touch sensitive device according to claim 13 or 14, wherein the control and calculating module is further configured to determine a touch position in a second direction according to the position of the one induction unit touched; and to determine a position of a touch point on the touch screen according to the touch position in the first direction and the touch position in the second direction.

16. The touch sensitive device according to claim 15, wherein the touch position in the second direction is determined by the control and calculating module by a centroid algorithm.

17. The touch sensitive device according to any one of claims 13-16, wherein the first direction is a length direction of each induction unit, the second direction is a direction vertical to each induction unit, and each induction unit is disposed horizontally or vertically.

18. The touch sensitive device according to claim 10, wherein the plurality of induction units are located in a same layer.

19. The touch sensitive device according to claim 10, wherein each induction unit comprises: a third part;

a fourth part;

a fifth part not intersecting with the fourth part;

the first electrode; and

the second electrode,

20. The touch sensitive device according to claim 10, wherein each induction unit comprises: a sixth part;

a seventh part;

the first electrode; and

the second electrode,

21. A portable electronic apparatus, comprising a touch sensitive device according to any one of claims 10-20.