Method for Locating Touch Points on a Touch Screen

Abstract

The present invention provides a touch screen, in which a plurality of detection areas defined in a grid pattern are defined in a touch area. Each of the detection areas respectively corresponds to a plurality of emitting diodes and receiving diodes at the edge of the touch screen. The emitting diodes and the receiving diodes are in one-to-one correspondence to form an opposed matrix, and the scanning of each detection area is independently controllable. The present invention also discloses a method for positioning touch points on a touch screen, which is particularly suitable for multi-touch point positioning. By dividing the touch area into a plurality of detection areas in a grid pattern and making the scanning of each detection area independently controllable, the present invention can solve the problem of increased algorithm complexity caused by size increase, and enable the system to quickly realize multi-point recognition and positioning and trajectory tracking.

Description

Technical Field

[0001] The present invention belongs to the technical field of touch control, and particularly relates to a touch screen and a positioning method for touch points on the touch screen, and is particularly applicable to large-size infrared touch screens. Background Art

[0002] In recent years, with the popular application of electronic devices such as smart phones and tablet computers, touch operations have become people's behavioral habits. Touch scenarios such as shared screens in conference rooms, touch payment terminals in hospitals, virtual touch keyboards on mobile phones, and multi-person interactive games on tablets have become people's daily life. The above multi-scenario applications and good human-computer interaction experiences are inseparable from multi-touch recognition technology. At the same time, in order to pursue more application scenarios and better user experiences, people's requirements for touch products are also constantly increasing, such as increasing the size of touch terminals. Currently, common touch systems are implemented by means of resistance, capacitance, surface acoustic wave, electromagnetic induction, and infrared technology, etc., and all of them can recognize multiple points within a short response time. However, as the size of the touch terminal continues to increase and the touch area expands, the complexity of the original multi-point recognition algorithm increases sharply, resulting in an increase in the response time, leading to delays, unsmoothness, and omissions during the recognition process. At the same time, the increase in size causes problems such as high costs, inconvenient transportation, and high post-maintenance costs for touch terminals.

[0003] Compared with resistive screens and capacitive screens, the infrared touch system has certain advantages in realizing large-size touch systems due to its simple principle, stable performance, low hardware material cost, easy splicing and assembly, and high cost performance.

[0004] The infrared touch system includes infrared emission and reception sensing elements. The infrared emission elements are installed on the outer frame of the touch screen to form an infrared detection network on the panel surface. Any touch body can change the infrared rays at the touch point and then convert them into the coordinates of the touch point to achieve the operation of the touch screen. A number of emission and reception diodes are closely arranged around the infrared touch system panel. As Figure 1 shown, white represents infrared emission tubes, and black represents infrared reception tubes. When the system is working properly, the infrared emission tubes are lit in sequence and received by the infrared reception tubes at the same time, forming an infrared cross-fire matrix network at this time. When there is a touch point moving in this matrix network, the infrared light is blocked, and at this time, the light intensity received by the infrared reception tube will change, causing a change in the voltage at the receiving end. By comparing and calculating with the voltage value of the infrared diode when there is no touch point blocking, the position of the current touch point can be determined.

[0005] In applications of touch systems such as virtual keyboards and multi-player interactive games, functions such as multi-touch point recognition, positioning, and trajectory tracking need to be implemented. As the number of touch points increases, the touch point scanning time will increase, which in turn affects the system response time and may cause problems such as system delays, breakpoints, and unsmoothness.

[0006] The easiest multi-touch recognition to implement is two-touch recognition. After horizontal and vertical scans, two different x 1 and x 2 coordinates, and two different y 1 and y 2 coordinates will be collected. After freely combining the horizontal and vertical coordinates, pseudo points are generated, making it impossible to accurately determine the position of the touch points. As shown in Figure 2 , where the black dots are touch points and the white dots are pseudo points. Therefore, removing pseudo points is the most important step in two-touch and above multi-touch recognition.

[0007] The currently common method for two-touch recognition is to add a diagonal scan to exclude pseudo points. Li Jun proposed in 2012 to change the direction of diodes through a hardware circuit to form different coordinate systems to exclude pseudo points; Zeng Yixiong proposed in 2013 to use software to control diodes to form different coordinate systems to achieve diagonal scanning, and then exclude pseudo points through the offset of each point in different coordinate systems; Hu Yuehui et al. proposed in 2013 to set the intersection of the connections between all diodes as pixels and determine the touch points by detecting the shape of the pixel formation area; Liu Zhimin proposed a special "dart throwing" algorithm in 2015 that can effectively exclude pseudo points. However, the above algorithms are mostly for two-touch recognition. When the number of touch points increases, the computational complexity of the algorithms increases continuously, and the algorithm complexity is further deepened. Therefore, an identification algorithm for multi-touch points is needed to effectively reduce the algorithm complexity while achieving the goal of multi-touch recognition. Summary of the Invention

[0008] The purpose of the present invention is to provide a touch screen and a method for positioning touch screen contact points to solve the problems in the prior art.

[0009] To achieve the above purpose, the technical solution provided by an embodiment of the present invention is as follows:

[0010] A touch screen, in which a plurality of grid-shaped detection areas are defined in the touch area, and each of the detection areas corresponds to a plurality of emitting diodes and receiving diodes at the edge of the touch screen respectively. The emitting diodes and the receiving diodes are in one-to-one correspondence to form a pair of radiation matrices, and the scanning of each detection area is independently controllable.

[0011] In one embodiment, the emitting diodes and the receiving diodes are infrared diodes or laser diodes.

[0012] A touch screen, comprising a touch panel, wherein a plurality of independently controllable transmitting units or receiving units are respectively installed at each edge of the touch panel.

[0013] Each of the transmitting units respectively includes a plurality of light-emitting diodes.

[0014] Each of the receiving units respectively includes a plurality of receiving diodes.

[0015] The light-emitting diodes and the receiving diodes correspond to each other one by one to form an opposed light matrix.

[0016] In one embodiment, the transmitting unit and / or the receiving unit is detachably connected to the touch panel.

[0017] In one embodiment, each of the transmitting units further respectively includes a bracket, and the plurality of light-emitting diodes are installed on the bracket; and / or

[0018] Each of the receiving units further respectively includes a bracket, and the plurality of receiving diodes are installed on the bracket.

[0019] In one embodiment, the brackets of the transmitting unit or the receiving unit respectively have a linear groove, and the light-emitting diodes or the receiving diodes are installed in the linear groove.

[0020] In one embodiment, the light-emitting diodes and the receiving diodes are infrared diodes or laser diodes.

[0021] A method for positioning touch points of a touch screen, comprising:

[0022] Dividing the touch area of the touch screen into a plurality of detection areas in a grid pattern, each detection area corresponding to a plurality of light-emitting diodes and receiving diodes, and the light-emitting diodes and the receiving diodes corresponding to each other one by one to form an opposed light matrix;

[0023] Independently scanning each detection area to obtain the coordinate information of the touch points in each detection area.

[0024] In one embodiment, if there are multiple touch points, false points need to be excluded by diagonal scanning.

[0025] A method for positioning touch points of a touch screen, which determines the touch points by controlling light scanning in a first direction and a second direction intersecting the first direction, comprising:

[0026] Controlling a plurality of groups of light scanning in the first direction to determine a first intermediate coordinate of the touch point in the first direction, and the plurality of groups of light in the first direction respectively include a plurality of scanning units;

[0027] Controlling a plurality of groups of light scanning in the second direction to determine a second intermediate coordinate of the touch point in the second direction, and the plurality of groups of light in the second direction respectively include a plurality of scanning units;

[0028] Control multiple scanning units associated with the first intermediate coordinate and the second intermediate coordinate simultaneously to scan, so as to respectively determine the first determined coordinate and the second determined coordinate of the contact point in the first direction and the second direction.

[0029] Compared with the prior art, the advantages of the present invention are as follows: The present invention adopts the design of a large-size touch terminal implemented by an infrared touch system. At the same time, in order to solve the problem of increased algorithm complexity caused by the increase in size, an optimized multi-point recognition algorithm is proposed, enabling the system to achieve multi-point recognition positioning and trajectory tracking within a short response time. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0031] Figure 1 Shown is a schematic diagram of the multi-point positioning principle of the infrared touch system;

[0032] Figure 2 Shown is a schematic diagram of false points in infrared touch;

[0033] Figure 3 Shown is a schematic diagram of the principle of a large-size infrared multi-point touch system in an embodiment of the present application;

[0034] Figure 4 Is a schematic diagram of the structure of a touch screen in an embodiment of the present invention;

[0035] Figure 5 Is a side view of a transmitting unit in an embodiment of the present invention;

[0036] Figure 6 Is a schematic diagram of the basic structure, numbering and re-splicing of a touch screen in an embodiment of the present invention;

[0037] Figure 7 Is a schematic diagram of the maximum number of false points in multi-point touch in an embodiment of the present invention;

[0038] Figure 8 Is a schematic diagram of the general arrangement form of multi-point touch in an embodiment of the present invention;

[0039] Figure 9 Is a flowchart of an infrared touch multi-point recognition method in an embodiment of the present invention;

[0040] Figure 10It is a schematic diagram of 45° oblique scanning in an embodiment of the present invention;

[0041] Figure 11 It is a schematic diagram of the set of points to be determined after 45° oblique scanning in an embodiment of the present invention;

[0042] Figure 12 It is a schematic diagram of 135° oblique scanning in an embodiment of the present invention;

[0043] Figure 13 It is a schematic diagram of the set of points to be determined after 135° oblique scanning in an embodiment of the present invention;

[0044] Figure 14 It is a schematic diagram of the angle between points to be determined in an embodiment of the present invention;

[0045] Figure 15 It is a schematic diagram of calculating the opening length of the receiving tube in an embodiment of the present invention;

[0046] Figure 16 It is a flowchart of the multi-point recognition algorithm in an embodiment of the present invention;

[0047] Figure 17 It is a schematic diagram of the blind area in an embodiment of the present invention;

[0048] Figure 18 It is a schematic diagram of horizontal scanning in an embodiment of the present invention;

[0049] Figure 19 It is a schematic diagram of vertical scanning in an embodiment of the present invention. Specific embodiments

[0050] The present invention will be described in detail below with reference to the embodiments shown in the drawings. However, these embodiments do not limit the present invention, and any structural, method, or functional transformation made by those of ordinary skill in the art based on these embodiments is included in the protection scope of the present invention.

[0051] Refer Figure 3 As shown, an embodiment of the present application provides a large-size infrared multi-touch system, which is mainly used for scanning experiments on the positions of multiple contact points. The system mainly includes a touch screen, wireless communication, and a human-computer interaction display terminal.

[0052] The wireless communication methods include wireless local area network (WLAN), Wi-Fi, Bluetooth, ZigBee connection, etc. In this case, since the system needs to continuously perform scanning and has no high requirements for communication distance and security performance, the ZigBee wireless communication method is preferably used, which can reduce the system power consumption and cost under the conditions of meeting data transmission and communication distance.

[0053] Specifically, in combination with Figure 4As shown in the figure, the touch screen 10 includes a touch screen 11, and a plurality of transmitting units 12 or receiving units 13 that are detachably installed at each edge of the touch screen 11 and are connected end to end.

[0054] The touch screen 11 can be a display screen or a flat panel. The flat panel material can be common acrylic, aluminum alloy, etc.

[0055] The transmitting unit 12 or the receiving unit 13 uses common infrared diodes or laser diodes, preferably infrared diodes. The diodes are arranged at equal intervals around the touch screen, and it is ensured that there is exactly one receiving diode facing each transmitting diode. The transmitting diodes and the receiving diodes are arranged in a crisscross manner.

[0056] As the size of the infrared touch screen continues to increase, the length of the transmitting unit 12 or the receiving unit 13 used will continue to increase, bringing inconvenience in transportation, installation, and maintenance. To solve the above problems, as shown in Figure 4 and Figure 6 This embodiment designs a splicing scheme, dividing the large-sized detection area into a grid of small-sized infrared detection areas, such as areas (1a, 1b, 1c, 1d), (5a, 4b, 5c, 4d), and each area can perform independent scanning, determine the real-time positioning of multiple points, and depict a two-dimensional trajectory. Splicing scheme for a large-sized infrared multi-touch system. When there is a touch point in the detection area, the main control chip MCU (STM32) controls the diodes to perform different scanning methods to determine the specific coordinates of the object, and then transmits them to the host computer through wireless communication, and displays the position of the object on the display terminal.

[0057] To illustrate that there are multiple transmitting or receiving units connected end to end distributed on the same edge of the touch screen, Figure 4 There is a certain gap between the transmitting units or receiving units in

[0058] As shown in Figure 5 and Figure 6 Each of the transmitting units 12 (corresponding to 1a, 2a, 3a... and 1b, 2b, 3b...) respectively includes a bracket 121 and a plurality of transmitting diodes 122 installed on the bracket ( Figure 6 Each unit in

[0059] Figure 6Among them, white represents the emitting diode, and black represents the receiving diode. According to the principle of light beam opposition, the emitting unit should be installed on any two adjacent sides, and the receiving unit is opposite to the emitting unit. The receiving or emitting units are connected end to end in sequence. According to the actual distribution of light intensity, the light intensity emitted by one emitting diode will be reflected on the receiving diodes within a certain range, and the infrared light intensity received by the receiving diode directly opposite the emitting diode will reach the peak value.

[0060] In order to enable independent scanning for each area, the emitting unit and the receiving unit can be numbered or labeled, and the control module reads the address information of each emitting unit or receiving unit and controls the scanning of the diodes in the corresponding control unit.

[0061] In one embodiment, in combination with Figure 5 As shown, the bracket 121 can be made of U-shaped aluminum alloy profile, and the emitting or receiving diodes are linearly installed in the groove 123 of the bracket 121. The bottom plate of the U-shaped aluminum alloy profile serves as the mounting plate for the emitting or receiving diodes, and the two extending arms of the U-shaped aluminum alloy profile serve as the light-shielding materials for the emitting or receiving diodes, which can exclude the interference of external ambient light.

[0062] The bracket 121 is detachably connected to the touch screen 11, and the detachable manner can be plugging, buckling or other ways.

[0063] Corresponding to the emitting unit, each of the receiving units includes a bracket and a plurality of receiving diodes installed on the bracket. The plurality of receiving diodes are linearly arranged, and the emitting diodes and the receiving diodes are in one-to-one correspondence.

[0064] The working principle of the touch screen is that the emitting diodes and the receiving diodes form a crisscross light matrix in one-to-one correspondence. When the user touches the screen, the contact object (finger or other object) will block the crisscross light passing through that position, and the controller can determine the position of the contact point on the screen through calculation.

[0065] The emitting diodes and the receiving diodes can selectively use infrared diodes or laser diodes according to requirements. In this embodiment, infrared light-emitting diodes are preferably used.

[0066] In one embodiment, the aspect ratio of the touch screen 11 is 16:9.

[0067] Based on the above structure, on the one hand of this case, by grouping the emitting diodes and the receiving diodes, each group includes a plurality of diodes and is integrally arranged, and each integrated unit is detachably arranged with the touch screen. When applied to a large-size touch screen, it is convenient for transportation and assembly, and different numbers of units can be installed according to needs.

[0068] Based on the above structure, on the other hand of this case, through the setting of the splicing method, it is beneficial to set different types of units. Different numbers of diodes can be set in different types of units, or different types of diodes can be selected, such as infrared diodes or laser diodes. In this way, users can select different types of units according to the requirements of resolution and response speed.

[0069] Based on the above structure, on the third aspect of this case, it is beneficial to the development of the touch screen industry. The unitized diode module can be used as an independent industrial link. End customers can selectively use units of different sizes and different diode categories according to their needs. At the same time, it is also beneficial to the development of the software system in this field. In order to adapt to this structure, the software needs to provide more selective functions.

[0070] Based on the above structure, on the fourth aspect of this case, when a certain unit is damaged, it will not affect other units, reducing the maintenance cost and having a fast maintenance speed.

[0071] After analyzing the existing common two-point recognition algorithms in this embodiment, a multi-point recognition algorithm for an infrared touch system is proposed to achieve multi-point recognition from three points to ten points.

[0072] When performing touch point positioning, if there is only one touch point, after one horizontal scan and one vertical scan, the exact position of the touch point can be obtained.

[0073] In one embodiment, the way of horizontal scan can refer to Figure 18 As shown, due to the large screen size, each emitting unit can independently perform a scan along the horizontal direction. Specifically, 8 diodes in each emitting unit are sequentially scanned horizontally, and the scans of all emitting units can be independently synchronized. Similarly, the way of vertical scan can refer to Figure 19 As shown, due to the large screen size, each emitting unit can independently perform a scan along the vertical direction.

[0074] According to the splicing scheme of the large size of the system, each small size detection area can perform independent scans simultaneously. Therefore, in the multi-point recognition problem, after horizontal and vertical scans, multiple horizontal and vertical coordinates will be obtained simultaneously. The free combination between the horizontal coordinates and the vertical coordinates generates a large number of pending points, forming a set of pending points. The pending points are discrete from each other and their coordinates are determined, including touch points and false points. If it is assumed that there are n touch points, at most n(n - 1) pending points can be generated. As Figure 7 shown, where the black dots are touch points and the white dots are false points. For a more general multi-point arrangement form, such as Figure 8 shown, at this time, due to the unknown number of touch points, the number of false points cannot be accurately calculated. Therefore, oblique scanning is required to exclude false points.

[0075] In summary, the process of the infrared touch multi-point recognition method provided in this embodiment is as follows Figure 9 As shown, first, through horizontal and vertical scans, all horizontal and vertical coordinates are determined, and a set of pending points is obtained by combination; then, through oblique scans at a specific angle, the touch points and pseudo points in the set of pending points are distinguished and classified; finally, the pseudo points can be eliminated to obtain the touch points.

[0076] Now, the multi-point recognition method will be described in detail. Taking the lower left corner vertex of the touch area as the coordinate origin, a rectangular coordinate system xoy is established.

[0077] In the first step, horizontal and vertical scans are performed. After the scans are completed, m x abscissas, m y ordinates, and the number of pending points are obtained. If , the accurate coordinates of the touch point can be output. If the number of abscissas or the number of ordinates , at this time, the touch point is a horizontal row or a vertical column, and there are no pseudo points. If it does not belong to the above special cases, then enter the second step.

[0078] In the second step, a 45° oblique scan is performed. During the oblique scan, when a certain oblique ray passes through pending points that contain both touch points and pseudo points, as shown by the solid lines in Figure 7 and Figure 8 , from the change in the electrical signal at the receiving end, it can be known that there are touch points on this ray, but the number of touch points and pseudo points cannot be determined. Therefore, it is considered that the angles formed by the connections between the points in the set of pending points can be used for scanning to eliminate pseudo points.

[0079] Taking the arrangement of touch points shown in Figure 8 as an example for illustration, as shown in Figure 10 . To ensure the normal implementation of the oblique scan, when the light is emitted from side AB, side CD is turned on while side BC is turned off. Similarly, when the light is emitted from side AD, side BC is turned on while side CD is turned off. Therefore, the solid lines in Figure 10 are the actually existing rays. To ensure a 45° scan, when the light is emitted from side AD, only the BQ section is turned on, where . Since the distance a between the diodes is equal, the equation of the actually existing ray is , where n is a natural number representing different rays, and is the equivalent spatial distance after quantifying the voltage value between adjacent diodes into 50 equal parts. When it is determined that there is no occlusion on a certain ray, by substituting the coordinates of the pending points into this ray equation, the pseudo points in the set of pending points can be determined and these points can be eliminated. For example, all the points on the ray PB in Figure 10 are pseudo points, through the PB ray equation Two spurious points passed by it can be removed. After this scan, the remaining set of points to be determined is as follows Figure 11 as shown.

[0080] In the third step, perform a 135° oblique scan, as shown in Figure 12 . Using the same method as in the second step, the remaining points to be determined are as shown in Figure 13 as shown.

[0081] In the fourth step, perform an oblique scan at an angle θ. After the previous steps, the number of points to be determined has been greatly reduced. At this time, a reference point M can be arbitrarily selected from the set of points to be determined, and the angle θ between the line connecting the remaining points and point M and the positive x-axis direction is calculated to obtain an angle set, as shown in Figure 14 as shown.

[0082] Since the light rays on side AB are only received by side CD, and the light rays on side AD are only received by side BC. For a certain angle θ, the receivable range on side BC is , as shown in Figure 15 as shown. Therefore, when side AD is turned on, only the BQ section is turned on. At the same time, the actual existing light ray angle θ will also be restricted by the aspect ratio of the touch area, that is , where, taking a touch area with an aspect ratio of 16:9 as an example, . At the same time, in order not to repeat the scanned angles, 0°, 45°, 90°, 135°, 180° and the same θ values in the angle set are excluded. Finally, there are j θ angles in the angle set. Arrange θ in descending order of number. Sequentially select the angles in the angle set for oblique scan. At this time, the equation of the actually existing light ray is . After the scan, spurious points can be excluded based on the points to be determined and the actual light ray equation to determine the touch points. At this time, the number of points in the set of points to be determined will continue to decrease. After one scan, in the remaining set of points to be determined, reselect the reference point M, and loop through the operations of solving and sorting the angle set, selecting the θ angle for scanning, and determining the touch points to exclude spurious points. Until the number of points in the set of points to be determined is 2, at this time there will be only one angle value in the angle set, that is, the angle corresponding to the line connecting the two points to be determined. At this time, select any angle except and 45°, 135° for one scan to determine all the points to be determined. In particular, when the number of θ in the angle set , it means that the points to be determined are on the 45° or 135° straight line, and all the points to be determined are touch points.

[0083] According to the above multi-point recognition method, the algorithm flow chart is as shown in Figure 16 .

[0084] In the above embodiment, BC is used as the x-axis. At this time, there are blind areas that cannot be scanned near the edges of AB and CD, as shown in Figure 17As shown, AB should be used as the x-axis and AD as the y-axis for diagonal scanning. However, due to the limitation of the aspect ratio (16:9), 45° and 135° scans cannot be performed at this time. Therefore, only one more diagonal scan at an angle θ, that is, the process of the fourth step above, is needed to determine whether there is a touch point in the blind area.

[0085] In another embodiment, a method for positioning touch points on a touch screen is also provided. The touch points are determined by controlling light scans in a first direction and a second direction intersecting the first direction, including:

[0086] (1) Controlling several groups of light scans in the first direction to determine a first intermediate coordinate of the touch point in the first direction, where each of the several groups of light in the first direction includes multiple scanning units;

[0087] (2) Controlling several groups of light scans in the second direction to determine a second intermediate coordinate of the touch point in the second direction, where each of the several groups of light in the second direction includes multiple scanning units;

[0088] (3) Controlling multiple scanning units associated with both the first intermediate coordinate and the second intermediate coordinate to scan, so as to respectively determine a first determined coordinate and a second determined coordinate of the touch point in the first direction and the second direction.

[0089] In this embodiment, since each detection area scan is independently controllable, a two-step method can be used to determine multiple touch points. In the first step, horizontal and vertical rough scans are first performed to obtain the detection area A where all touch points are located. In the second step, only the detection area A is independently scanned to further determine the specific positions of the touch points.

[0090] In summary, for the problems of current common touch control terminals such as resistive and capacitive screens, with the increase in size, it is difficult to achieve both good response time and high resolution, inconvenient transportation, high cost and high later maintenance cost. The present invention uses an infrared touch control system to implement a large-size touch control terminal. At the same time, aiming at the disadvantages of common multi-point recognition algorithms, such as the increase in algorithm complexity and response time with the increase in the number of points, the multi-point recognition algorithm is optimized. Finally, the design of a large-size infrared multi-point touch control system is completed, realizing multi-point recognition and multi-point trajectory tracking, better meeting people's needs for large-size, multi-point recognition and trajectory tracking of touch control terminals, and can be applied to fields such as office, teaching, medical treatment, and entertainment.

[0091] It is obvious to those skilled in the art that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, in any aspect, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be embraced within the present invention. Any reference signs in the claims should not be construed as limiting the claims involved.

[0092] In addition, it should be understood that although this specification is described in terms of embodiments, not every embodiment only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementation manners that can be understood by those skilled in the art.

Claims

1. A method for positioning touch points of a touch screen, the touch screen comprising a touch panel, and a plurality of independently controllable transmitting units or receiving units are respectively installed on each edge of the touch panel. Each of the transmitting units respectively includes a plurality of light-emitting diodes; each of the receiving units respectively includes a plurality of receiving diodes ； The light-emitting diodes and the receiving diodes are in one-to-one correspondence to form an opposed matrix; It is characterized in that The positioning method includes: The touch area of the touch screen is divided into a plurality of detection areas in a grid pattern. Each detection area respectively corresponds to a plurality of light-emitting diodes and receiving diodes. The light-emitting diodes and the receiving diodes are in one-to-one correspondence to form an opposed matrix, and the scanning of each detection area is independently controllable; Each detection area is scanned independently to obtain the contact point coordinate information of each detection area; If there are multiple contact points, false points are excluded through diagonal scanning; Among them, first, through horizontal and vertical scanning, all horizontal and vertical coordinates are determined, and a set of pending points is obtained by combination; then, through diagonal scanning at a specific angle, the touch points and false points in the set of pending points are distinguished and classified; finally, the false points are removed to obtain the touch points; During diagonal scanning, when a certain diagonal ray passes through pending points that contain both touch points and false points, the angles formed by the connections between the points in the set of pending points are used for scanning to exclude false points; During diagonal scanning, first perform a 45° diagonal scan, then perform a 135° diagonal scan to exclude some false points. Arbitrarily select a reference point M from the remaining set of points to be determined, calculate the angle θ of the line connecting the remaining points to point M with respect to the positive x-axis direction, obtain an angle set, number and arrange θ from large to small, and sequentially select the angles for diagonal scanning to exclude false points and determine the touch point. After one round of scanning, in the remaining set of points to be determined, re-select the reference point M, and loop through the operations of solving and sorting the angle set, selecting the θ angle for scanning, and determining the touch point and excluding false points.

2. The method for positioning touch points of a touch screen according to claim 1, It is characterized in that The light-emitting diodes and the receiving diodes are infrared diodes or laser diodes.

3. The method for positioning touch points of a touch screen according to claim 1, It is characterized in that The transmitting unit and / or the receiving unit is detachably connected to the touch panel.

4. The method for positioning touch points of a touch screen according to claim 1, It is characterized in that Each of the transmitting units further respectively includes a bracket, and the plurality of light-emitting diodes are installed on the bracket; and / or Each of the receiving units further respectively includes a bracket, and the plurality of receiving diodes are installed on the bracket.

5. The method for positioning touch points of a touch screen according to claim 4, It is characterized in that The brackets of the transmitting unit or the receiving unit respectively have a linear groove, and the light-emitting diodes or the receiving diodes are installed in the linear groove.

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