A real touch point recognition method of an infrared touch screen and an infrared touch screen

Abstract

The present application relates to a kind of infrared touch screen real touch point recognition method and infrared touch screen, method includes: the slope k of all n pieces of blocked light in first coordinate system is calculated with intercept b, obtain n groups of numerical combinations;N groups of numerical combinations are filled into kob second coordinate system, obtain n coordinate points;Identify alternative touch area in first coordinate system;The number of internal blocked light of each alternative touch area centroid point coordinate value is calculated, from the alternative touch area that is not selected, the number of internal blocked light most is selected as target alternative touch area, the centroid point coordinate value thereof is mapped as a virtual straight line in second coordinate system, all coordinate points in the range of the virtual straight line and both sides are marked as cleared, stop until the coordinate point marked as cleared reaches preset proportion, with the X coordinate value and Y coordinate value of the virtual straight line each corresponding as the coordinate of each point, realize the coordinate of each real point when multi-point touch is quickly and accurately judged.

Description

Technical Field

[0001] This invention relates to the field of infrared touch screen technology, specifically to a method for recognizing real touch points on an infrared touch screen and an infrared touch screen itself. Background Technology

[0002] When performing a single-point touch on an infrared touchscreen, since there is only one touch point, this touch point is the true touch point (real touch point), and its touch position can be directly determined. However, when performing multi-point touch on an infrared touchscreen, in addition to the true touch point, there are often false touch points. False touch points are formed when the light rays corresponding to the true touch point intersect at other locations. Before the true and false attributes of true and false touch points are determined, they are all suspicious points where a touch occurred. Existing technologies typically use complex algorithms to calculate each suspicious point simultaneously in multiple processes. Only after each false touch point is eliminated through calculation can the number of true touch points and the coordinate positions of each true touch point be accurately determined. Because the algorithm is relatively complex, it takes a long time. When there are a large number of false touch points, the touch latency becomes more noticeable, affecting the user's touch operation experience. Summary of the Invention

[0003] Based on the above situation, the main objective of this invention is to provide a real touch point recognition method and an infrared touch screen, which can efficiently, quickly and accurately determine the coordinate position of each real point during multi-touch, significantly improving the user's touch operation experience.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0005] In a first aspect, the present invention provides a method for recognizing real touch points on an infrared touchscreen, the method comprising the following steps:

[0006] Determine the blocked light rays: Calculate the slope k and intercept b of all n blocked light rays in the first coordinate system, obtaining n sets of numerical combinations (k1, b1), (k2, b2), (k3, b3)...(k n ,b n );

[0007] Perform coordinate transformation: Using k as the x-coordinate of the second coordinate system and b as the y-coordinate, combine the n sets of values ​​and fill them into the second coordinate system to obtain n coordinate points (k1, b1), (k2, b2), (k3, b3)...(k... n ,b n );

[0008] identifying candidate touch areas in the first coordinate system, each candidate touch area being enclosed by a plurality of boundary occluded rays, each boundary occluded ray being adjacent to a non-occluded ray, and the number of occluded rays inside each candidate touch area being no less than a preset number;

[0009] determining real touch point coordinates, calculating the coordinates of the center of gravity of each candidate touch area (X1, Y1), (X2, Y2), (Xn, Yn), and the number of occluded rays inside each candidate touch area, T being the total number of candidate touch areas; selecting one candidate touch area with the largest number of occluded rays from the unselected candidate touch areas as a target candidate touch area, mapping the coordinates of the center of gravity of the target candidate touch area to a virtual straight line in the second coordinate system, the virtual straight line having the X value of the coordinates as the slope and the Y value of the coordinates as the intercept; marking all coordinate points in the n coordinate points that are on the virtual straight line and within the allowable range on both sides of the virtual straight line as cleared until the number of coordinate points marked as cleared in the n coordinate points reaches a preset proportion; and taking the X and Y coordinates of the virtual straight line as the position coordinates of each real touch point in the first coordinate system. T T

[0010] Preferably, the infrared touch screen comprises an infrared emission-receiving lamp group, the infrared emission-receiving lamp group comprising at least a plurality of pairs of oppositely arranged infrared emission lamps and infrared receiving lamps, wherein the infrared light emitted by each emission lamp can be received by a plurality of continuously arranged receiving lamps on the opposite side.

[0011] The step of determining the occluded rays comprises:

[0012] According to the signal feedback of the receiving lamps, the rays with a signal strength less than a predetermined threshold value are determined as the occluded rays caused by the touch, so as to identify the n occluded rays.

[0013] For each occluded ray, the slope k and the intercept b of the ray in the first coordinate system are calculated according to the respective coordinates of the emission lamp and the receiving lamp of the ray in the first coordinate system.

[0014] Preferably, the predetermined threshold value is 15% of the signal strength of the rays that should be received under normal non-occluded conditions.

[0015] Preferably, in the step of determining the real touch point coordinates, the allowable range is a range in which the horizontal and vertical distances from the virtual straight line are both less than 3% of the minimum cell length of the corresponding coordinate axis.

[0016] ​​In a second aspect, the present invention provides an infrared touch screen, the touch screen comprising:

[0017] The module for determining the obstructed light rays is used to calculate the slope k and intercept b of all n obstructed light rays in the first coordinate system, obtaining n sets of numerical combinations (k1, b1), (k2, b2), (k3, b3)...(k n ,b n );

[0018] The coordinate transformation module is used to combine the n sets of values ​​into the second coordinate system, using k as the x-coordinate and b as the y-coordinate, to obtain n coordinate points (k1, b1), (k2, b2), (k3, b3)...(k...). n ,b n );

[0019] The alternative touch area recognition module is used to recognize alternative touch areas in the first coordinate system. The alternative touch area is formed by the intersection of multiple occluded light rays. The light ray that is closely adjacent to each occluded light ray is an unoccluded light ray. The number of occluded light rays inside the alternative touch area is not less than a preset number.

[0020] The actual touch point coordinate determination module is used to calculate the centroid coordinates (X1, Y1), (X2, Y2), ..., (X...) of each candidate touch area. T ,Y T The number of light blocks inside the selected touch area is T, where T is the total number of candidate touch areas. The candidate touch area with the largest number of light blocks inside is selected from the unselected candidate touch areas as the target candidate touch area. The centroid coordinates of the target candidate touch area are mapped to a virtual straight line in the second coordinate system. The virtual straight line has an X-value as its slope and a Y-value as its intercept. All coordinate points located on or within the allowable range on either side of the virtual straight line are marked as cleared until the number of cleared coordinate points reaches a preset proportion. The X and Y coordinates corresponding to the virtual straight lines are used as the position coordinates of each real touch point in the first coordinate system.

[0021] Preferably, the infrared touch screen includes an infrared emitting and receiving light group, which includes at least multiple sets of infrared emitting lights and infrared receiving lights arranged opposite each other, wherein the infrared light emitted by each emitting light can be received by several consecutively arranged receiving lights opposite each other;

[0022] The blocked light determination module includes:

[0023] A determining sub-module is configured to determine the light rays with received signal strength less than a predetermined threshold as the light rays blocked by the multi-point touch trigger according to the signal feedback of the receiving lamps, so as to find all n blocked light rays.

[0024] A calculating sub-module is configured to calculate the slope k and the intercept b of each blocked light ray in the first coordinate system according to the respective coordinate values of the emitting lamp and the receiving lamp of the light ray in the first coordinate system.

[0025] Preferably, the predetermined threshold is 15% of the signal strength of the light ray that should be received in the normal non-blocked case.

[0026] Preferably, when the corresponding coordinate point is recorded as cleared, the allowable range is a range in which the horizontal and vertical distances from the virtual straight line are both less than 3% of the minimum cell edge length of the corresponding coordinate axis.

[0027] In a third aspect, the present application provides an electronic display device comprising the touch screen as described above.

[0028] Preferably, the electronic display device is a touch all-in-one machine, a smart interactive screen, a smart electronic whiteboard, a smart electronic blackboard or a smart home appliance.

[0029] The present application calculates the slope k and intercept b of each light ray blocked by touch in the first coordinate system, converts each blocked light ray from a straight line in the first coordinate system to a corresponding point in the kob coordinate system as the second coordinate system, then selects an area with no less than a preset number of internal blocked light rays as a candidate touch area in the first coordinate system, calculates the centroid coordinates of each candidate touch area, sorts the centroid coordinates according to the number of blocked light rays in the corresponding area, and draws a virtual straight line in the second coordinate system with the horizontal coordinate as the slope and the vertical coordinate as the intercept, marks all coordinate points on the virtual straight line and within the allowable range on both sides as cleared, stops reading and drawing the virtual straight line when the marked coordinate points reach a preset proportion, and uses the X and Y coordinate values of the virtual straight line as the position coordinates of the true point in the infrared touch screen. Because the number of blocked light rays in the candidate touch area with a true point is often significantly more than the number of blocked light rays in the candidate touch area with a false point, the coordinate points on the virtual straight line drawn first in the second coordinate system and within the allowable range on both sides can be considered as blocked light rays in the real touch area (candidate touch area with a true point) after enough coordinate points in the second coordinate system are marked as cleared, and it can be considered that all blocked light rays in the real touch area are found and cleared, and the X and Y coordinate values of the virtual straight line drawn in the second coordinate system are the position coordinates of the true point in the infrared touch screen.

[0030] The present application directly starts from the candidate touch area with a true point, stops after enough coordinate points in the second coordinate system are marked as cleared, obtains the number of true points and their position coordinates when multi-point touch occurs, and effectively saves the operation steps and significantly improves the operation efficiency and user touch operation experience compared to the prior art which needs to exclude false points one by one.

[0031] Other benefits of the present application will be described in the specific embodiments through the introduction of specific technical features and technical solutions, and those skilled in the art should be able to understand the benefits brought by the technical features and technical solutions. BRIEF DESCRIPTION OF DRAWINGS

[0032] The preferred embodiments of the present application will be described below with reference to the accompanying drawings. In the drawings:

[0033] Figure 1Flow chart of one embodiment of the real touch point recognition method of the infrared touch screen of the present application;

[0034] Figure 2 Schematic diagram of one embodiment of all n blocked light rays in the vertical direction of the present application;

[0035] Figure 3 Schematic diagram of one embodiment of an alternative touch area (internal blocked light rays not shown) of the present application;

[0036] Figure 4 Schematic diagram of one embodiment of the second coordinate system after coordinate conversion of the present application;

[0037] Figure 5 is a schematic diagram of the first virtual straight line made to the second coordinate system of Figure 4 DETAILED DESCRIPTION

[0038] The present application is described below based on embodiments, but the present application is not limited to only these embodiments. In the following detailed description of the present application, some specific details are described in detail in order to avoid obscuring the essence of the present application, and well-known methods, processes, procedures, elements are not described in detail.

[0039] In addition, those of ordinary skill in the art will understand that the drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale.

[0040] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

[0041] In the description of the present application, it should be understood that the terms "first", "second", etc. are only for the purpose of description and cannot be understood as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise stated, the meaning of "multiple" is two or more.

[0042] Description: The infrared touch screen in the present application includes an infrared emission and reception lamp group, the infrared emission and reception lamp group includes oppositely arranged infrared emission lamps and infrared reception lamps, wherein the infrared light emitted by each emission lamp can be received by the opposite several continuously arranged reception lamps.

[0043] The first coordinate system in the present application is an XOY coordinate system, the X axis corresponds to one horizontal edge or one vertical edge of the infrared touch screen, the Y axis corresponds to one vertical edge or one horizontal edge of the infrared touch screen, and the origin O is the intersection of the one horizontal edge and the one vertical edge. ​

[0044] The blocked light rays in the present application are the light rays emitted by the infrared emitting lamps towards the opposite infrared receiving lamps, and the light rays are blocked and cannot be normally received by the infrared receiving lamps due to the occurrence of touch.

[0045] The blocked light rays in the vertical direction mentioned in the present application not only include the blocked light rays perpendicular to the horizontal edges of the infrared touch screen, but also include the light rays with angles other than 90 degrees with the horizontal edges of the infrared touch screen, as long as the light rays are emitted by the vertical infrared emitting lamps towards the opposite infrared receiving lamps. Similarly, the blocked light rays in the horizontal direction are not limited to the light rays perpendicular to the vertical edges of the infrared touch screen.

[0046] In a first aspect, in combination with the drawings Figures 1-5 The present application provides a real touch point recognition method of an infrared touch screen,

[0047] The method comprises the following steps:

[0048] Determining the blocked light rays: calculating the slopes k and intercepts b of all n blocked light rays in the first coordinate system (see the drawings) Figure 2 Taking the X axis as corresponding to a horizontal edge of the infrared touch screen and the Y axis as corresponding to a vertical edge of the infrared touch screen, n blocked light rays in the vertical direction are shown), n sets of numerical combinations (k1, b1), (k2, b2), (k3, b3) … (kn, bn) are obtained. n n ;

[0049] Coordinate conversion: taking k as the horizontal coordinate of the second coordinate system and b as the vertical coordinate of the second coordinate system, filling the n sets of numerical combinations into the second coordinate system, and obtaining n coordinate points (k1, b1), (k2, b2), (k3, b3) … (kn, bn). n n ;

[0050] Identifying the alternative touch area: identifying the alternative touch area in the first coordinate system, the alternative touch area is enclosed by the intersection of multiple boundary blocked light rays, each boundary blocked light ray is closely adjacent to a non-blocked light ray, and the number of the blocked light rays in the interior of the alternative touch area is not less than a preset number.

[0051] Determining the coordinates of the real touch point: calculating the centroid point coordinate values (X1, Y1), (X2, Y2) … (Xn, Yn) of each alternative touch area. T T ​​​) and the number of the inside blocked light rays, T is the total number of the alternative touch areas; one of the alternative touch areas with the largest number of inside blocked light rays is selected as a target alternative touch area from the alternative touch areas that are not selected, a centroid point coordinate value of the target alternative touch area is mapped as a virtual straight line in the second coordinate system, the virtual straight line has an X value in the coordinate value as a slope and a Y value in the coordinate value as an intercept; all coordinate points in the n coordinate points that are located on the virtual straight line and within a permissible range on both sides of the virtual straight line are marked as cleared until the coordinate points marked as cleared in the n coordinate points reach a preset proportion; and the X coordinate value and the Y coordinate value corresponding to each virtual straight line are taken as position coordinates of each real touch point in the first coordinate system.

[0052] The application provides a novel and highly feasible real point position coordinate determination method for a multi-touch infrared touch screen.

[0053] The infrared touch screen used in the application comprises a plurality of infrared emitting and receiving lamp groups arranged around the frame, and at least a plurality of groups of oppositely arranged infrared emitting lamps and infrared receiving lamps, wherein infrared light emitted by each emitting lamp can be received by a plurality of continuously arranged receiving lamps on the opposite side.

[0054] Specifically, first, the application calculates the slope k and the intercept b of each blocked light ray in the XOY coordinate system as the first coordinate system, and represents each blocked light ray by a straight line in the first coordinate system, and then converts the blocked light ray to a corresponding point in the kob coordinate system as the second coordinate system through coordinate transformation.

[0055] Then in the first coordinate system, select the region with the number of internal blocked light rays no less than the preset number as the candidate touch region, and each candidate touch region is enclosed by the intersection of multiple boundary blocked light rays (see FIG. 2, in which each inclined straight line is a boundary blocked light ray, and the rhombus enclosed by the dashed oval is a candidate touch region, and the blocked light rays inside the candidate touch region are not shown). Figure 3 The preset number can be determined according to actual conditions and accuracy requirements. In most cases, the preset number is 3-4. Understandably, if there is no blocked light ray inside a region or the number of blocked light rays is too small, it is impossible that the region is the touch region of the true point, and basically no false point is formed. Therefore, the region with the number of internal blocked light rays greater than or equal to 3 or 4 is usually selected as the candidate touch region. These candidate touch regions actually include the touch region of the true point and the touch region of the false point.

[0056] The total number of candidate touch regions is counted as T, the centroid coordinates of each candidate touch region are calculated, and if a candidate touch region is determined to be the touch region of the true point, the centroid coordinates are regarded as the position coordinates of the true point. According to the number of blocked light rays inside each candidate touch region from more to less, the T sets of centroid point coordinate values are sorted. The sorting is used to provide the order of drawing multiple virtual straight lines for the operation steps of "determining the real touch point coordinates" below.

[0057] The following is an introduction related to the step of determining the real touch point coordinates combined with a specific example. In the example, there are 7 candidate touch regions, and according to the number of blocked light rays inside the corresponding region from more to less, the sorted order of the centroid point coordinate values of each candidate touch region is (X2, Y2), (X4, Y4), (X5, Y5), (X1, Y1), (X3, Y3), (X6, Y6), (X7, Y7).

[0058] Then, in the subsequent operation step, the two coordinate values in (X2, Y2) are read first, and a virtual straight line is made in the second coordinate system with X2 as the slope and Y2 as the intercept, and all coordinate points located on the virtual straight line and within the allowable range on both sides of the virtual straight line are marked as cleared. The reason why the coordinate points within the allowable range on both sides of the virtual straight line are also marked as cleared is that not all the occluded light rays in each candidate region pass through the centroid point, and only the corresponding points of the light rays passing through the centroid point are on the virtual straight line made with the horizontal coordinate and vertical coordinate values of the centroid point in the first coordinate system as the slope and intercept in the second coordinate system. Therefore, the coordinate points within the allowable range on both sides of the virtual straight line are also marked as cleared, that is, the straight line corresponding to the coordinate points within the allowable range on both sides of the virtual straight line in the first coordinate system is also identified as the occluded light rays of the candidate touch region. Through such a compensation method, all the corresponding points of the occluded light rays in the candidate touch region with centroid coordinates (X2, Y2) in the second coordinate system are marked as cleared.

[0059] Then, a virtual straight line is made in the second coordinate system with X4 as the slope and Y4 as the intercept, and all coordinate points located on the virtual straight line and within the allowable range on both sides of the virtual straight line are marked as cleared, and it is calculated whether the coordinate points marked as cleared among the n coordinate points have reached the preset proportion. If they have reached the preset proportion, the next virtual straight line is stopped, because the number of virtual straight lines made in the second coordinate system is 2 at this time, and it is known that the number of true points in this multi-point touch is 2, with (X2, Y2) and (X4, Y4) as the coordinates of the two true points in the first coordinate system. If it is found through calculation that the coordinate points marked as cleared among the n coordinate points have not reached the preset proportion, then a virtual straight line is made in the second coordinate system with X5 as the slope and Y5 as the intercept, and all coordinate points located on the virtual straight line and within the allowable range on both sides of the virtual straight line are marked as cleared, until the coordinate points marked as cleared among the n coordinate points reach the preset proportion, and the reading and making of virtual straight lines is stopped. The number of virtual straight lines made in the second coordinate system is the number of true points, and the respective X and Y coordinate values of the made virtual straight lines are taken as the position coordinates of each true point in the first coordinate system.

[0060] The preset proportion can be determined according to actual conditions and precision requirements, for example, 95% or 90%. The preset proportion is not required to be 100% because the infrared touch screen is usually relatively large in size, and a certain tolerance is inevitably generated in the manufacturing process. Therefore, the slope and intercept of each blocked light in the first coordinate system have very low deviations in the calculation results, and thus there are always a small number of points in the second coordinate system that cannot be eliminated.

[0061] As can be understood by those skilled in the art, because the false points are formed by the blocked light corresponding to the actual touch true point intersecting at other positions, in the alternative touch area, the light in the alternative touch area where the false point is located actually coincides with a part of the light in the alternative touch area where the true point is located (i.e., there is no new light in the alternative touch area where the true point is located in the alternative touch area where the false point is located), but the number of blocked light in the alternative touch area where the true point is located should be much more than that in the alternative touch area where the false point is located. Therefore, in the above operation steps of clearing the coordinate points, only the horizontal coordinate and the vertical coordinate of the centroid of a part of the alternative touch area are used as the slope and intercept in the second coordinate system to draw a virtual straight line, and the number of blocked light in this part of the alternative touch area is more than that in the remaining alternative touch areas. Therefore, as long as the coordinate points exceeding the preset proportion are recorded as cleared, it means that all the blocked light in the first coordinate system has been basically checked, and all the blocked light in the alternative touch area where the true point is located is basically all the blocked light in the first coordinate system. Therefore, after all the blocked light in the first coordinate system is basically checked, it can be determined that all the true points have been found, and the position coordinates of the true points are completely satisfied with the accuracy and precision requirements.

[0062] Preferably, the infrared touch screen comprises an infrared emission-receiving lamp group, and the infrared emission-receiving lamp group comprises at least a plurality of pairs of oppositely arranged infrared emission lamps and infrared receiving lamps, wherein the infrared light emitted by each emission lamp can be received by a plurality of continuously arranged receiving lamps opposite to the emission lamp.

[0063] The step of determining the blocked light comprises:

[0064] According to the signal feedback of the receiving lamp, the light with a signal strength less than a predetermined threshold is determined as the blocked light caused by the touch, so as to identify all the n blocked lights.

[0065] For each blocked light, the slope k and the intercept b of the light in the first coordinate system are calculated according to the respective coordinate values of the emission lamp and the receiving lamp of the light in the first coordinate system.

[0066] Based on the signal feedback from the receiving light, it is easy and quick to determine which light rays are blocked, making it convenient to identify the blocked light rays.

[0067] Preferably, the predetermined threshold is 15% of the light signal intensity that should be received under normal, unobstructed conditions.

[0068] Since touch often cannot completely block light, by reasonably determining the preset threshold, all blocked light can be found with the highest possible accuracy.

[0069] Preferably, in the step of determining the coordinates of the actual touch point, the allowable range is a range in which both the horizontal and vertical spacing from the virtual straight line is less than 3% of the side length of the smallest cell of the corresponding coordinate axis.

[0070] Specifically, the allowable range can be flexibly set according to accuracy requirements. To improve accuracy, the allowable range is set to a range where both the horizontal and vertical spacing from the virtual line are less than 3% of the side length of the smallest cell on the corresponding coordinate axis. The side length of the smallest cell can also be set according to actual conditions and accuracy requirements, for example, 5mm, 10mm, etc. The shorter the side length of the smallest cell, the higher the accuracy that can be achieved.

[0071] Secondly, the present invention also provides an infrared touch screen, the touch screen comprising:

[0072] The module for determining the obstructed light rays is used to calculate the slope k and intercept b of all n obstructed light rays in the first coordinate system, obtaining n sets of numerical combinations (k1, b1), (k2, b2), (k3, b3)...(k n ,b n );

[0073] The coordinate transformation module is used to combine the n sets of values ​​into the second coordinate system, using k as the x-coordinate and b as the y-coordinate, to obtain n coordinate points (k1, b1), (k2, b2), (k3, b3)...(k...). n ,b n );

[0074] The alternative touch area recognition module is used to recognize alternative touch areas in the first coordinate system. The alternative touch area is formed by the intersection of multiple occluded light rays. The light ray that is closely adjacent to each occluded light ray is an unoccluded light ray. The number of occluded light rays inside the alternative touch area is not less than a preset number.

[0075] The actual touch point coordinate determination module is used to calculate the centroid coordinates (X1, Y1), (X2, Y2), ..., (X...) of each candidate touch area. T ,YT ) and the number of the light rays inside the alternative touch area being blocked, T is the total number of the alternative touch areas; one of the alternative touch areas with the largest number of the light rays inside being blocked is selected as a target alternative touch area from the alternative touch areas not being selected, a centroid coordinate value of the target alternative touch area is mapped as a virtual straight line in the second coordinate system, the virtual straight line has an X value in the coordinate value as a slope and a Y value in the coordinate value as an intercept; all coordinate points in the n coordinate points located on the virtual straight line and within a permissible range on both sides of the virtual straight line are marked as cleared until the coordinate points marked as cleared in the n coordinate points reach a preset proportion; and the X coordinate value and the Y coordinate value corresponding to each virtual straight line are taken as position coordinates of each real touch point in the first coordinate system.

[0076] Preferably, the infrared touch screen comprises an infrared emission-reception lamp group, the infrared emission-reception lamp group comprises at least a plurality of groups of oppositely arranged infrared emission lamps and infrared reception lamps, wherein the infrared light emitted by each emission lamp can be received by a plurality of continuously arranged reception lamps on the opposite side.

[0077] The blocked light ray determining module comprises:

[0078] A determining sub-module is configured to determine, according to the signal feedback of the reception lamp, the light rays with a signal strength less than a predetermined threshold as the light rays blocked by the multi-point touch, so as to find all n blocked light rays.

[0079] A calculating sub-module is configured to calculate, for each blocked light ray, a slope k and an intercept b of the light ray in the first coordinate system according to the respective coordinate values of the emission lamp and the reception lamp of the light ray in the first coordinate system.

[0080] Preferably, the predetermined threshold is 15% of the signal strength of the light rays that should be received in the case of no blocking.

[0081] Preferably, when the real touch point coordinate determining module marks the corresponding coordinate points as cleared, the permissible range is a range in which the horizontal and vertical spacings from the virtual straight line are both less than 3% of the minimum cell edge length of the corresponding coordinate axis.

[0082] The infrared touch screen provided by the application can well implement the real touch point recognition method of the infrared touch screen as described above, so that the infrared touch screen can efficiently, quickly and accurately determine the coordinate positions of the real touch points in the case of multi-point touch, and significantly improves the touch operation experience of the user.

[0083] In a third aspect, the application further provides an electronic display device comprising the touch screen described above.

[0084] Preferably, the electronic display device is a touch all-in-one machine, a smart interactive screen, a smart electronic whiteboard, a smart electronic blackboard or a smart household appliance.

[0085] Those skilled in the art can understand that the above-mentioned preferred embodiments can be freely combined and superimposed without conflict.

[0086] It should be understood that the above embodiments are only exemplary and not limiting, and various obvious or equivalent modifications or replacements to the above details can be made by those skilled in the art without departing from the essential principles of the present application, and all of them will be included in the scope of the claims of the present application.

Claims

1. A method for recognizing real touch points on an infrared touchscreen, characterized in that, The method includes the following steps: Determine the blocked light rays: Calculate the slope k and intercept b of all n blocked light rays in the first coordinate system, obtaining n sets of numerical combinations (k1, b1), (k2, b2), (k3, b3)...(k n ,b n ); Perform coordinate transformation: Using k as the x-coordinate of the second coordinate system and b as the y-coordinate, combine the n sets of values ​​and fill them into the second coordinate system to obtain n coordinate points (k1, b1), (k2, b2), (k3, b3)...(k... n ,b n ); Identify candidate touch areas: Identify candidate touch areas in the first coordinate system. The candidate touch area is formed by the intersection of multiple occluded light rays. The light ray closely adjacent to each occluded light ray is an unoccluded light ray. The number of occluded light rays inside the candidate touch area is not less than a preset number. Determine the actual touch point coordinates: Calculate the centroid coordinates (X1, Y1), (X2, Y2), ..., (X...) of each candidate touch area. T ,Y T The number of light blocks inside the selected touch area is T, where T is the total number of candidate touch areas. The candidate touch area with the largest number of light blocks inside is selected from the unselected candidate touch areas as the target candidate touch area. The centroid coordinates of the target candidate touch area are mapped to a virtual straight line in the second coordinate system. The virtual straight line has an X-value as its slope and a Y-value as its intercept. All coordinate points located on or within the allowable range on either side of the virtual straight line are marked as cleared until the number of cleared coordinate points reaches a preset proportion. The X and Y coordinates corresponding to the virtual straight lines are used as the position coordinates of each real touch point in the first coordinate system.

2. The method according to claim 1, characterized in that, The infrared touch screen includes an infrared emitting and receiving light group, which includes at least multiple sets of infrared emitting lights and infrared receiving lights arranged opposite each other, wherein the infrared light emitted by each emitting light can be received by several consecutively arranged receiving lights opposite it. The step of determining the blocked light includes: Based on the signal feedback from the receiving light, light with a received signal strength less than a predetermined threshold is identified as blocked light caused by the touch, thereby identifying all n blocked light rays; For each blocked ray of light, the slope k and intercept b of the ray in the first coordinate system are calculated based on the coordinate values ​​of the emitting and receiving lights of the ray in the first coordinate system.

3. The method according to claim 2, characterized in that, The predetermined threshold is 15% of the light signal intensity that should be received under normal, unobstructed conditions.

4. The method according to claim 1, characterized in that, In the step of determining the coordinates of the actual touch point, the allowable range is a range in which both the horizontal and vertical spacing from the virtual line is less than 3% of the side length of the smallest cell of the corresponding coordinate axis.

5. An infrared touch screen, characterized in that, The touchscreen includes: The module for determining the obstructed light rays is used to calculate the slope k and intercept b of all n obstructed light rays in the first coordinate system, obtaining n sets of numerical combinations (k1, b1), (k2, b2), (k3, b3)...(k n ,b n ); The coordinate transformation module is used to combine the n sets of values ​​into the second coordinate system, using k as the x-coordinate and b as the y-coordinate, to obtain n coordinate points (k1, b1), (k2, b2), (k3, b3)...(k...). n ,b n ); The alternative touch area recognition module is used to recognize alternative touch areas in the first coordinate system. The alternative touch area is formed by the intersection of multiple occluded light rays. The light ray that is closely adjacent to each occluded light ray is an unoccluded light ray. The number of occluded light rays inside the alternative touch area is not less than a preset number. The actual touch point coordinate determination module is used to calculate the centroid coordinates (X1, Y1), (X2, Y2), ..., (X...) of each candidate touch area. T ,Y T The number of light blocks inside the selected touch area is T, where T is the total number of candidate touch areas. The candidate touch area with the largest number of light blocks inside is selected from the unselected candidate touch areas as the target candidate touch area. The centroid coordinates of the target candidate touch area are mapped to a virtual straight line in the second coordinate system. The virtual straight line has an X-value as its slope and a Y-value as its intercept. All coordinate points located on or within the allowable range on either side of the virtual straight line are marked as cleared until the number of cleared coordinate points reaches a preset proportion. The X and Y coordinates corresponding to the virtual straight lines are used as the position coordinates of each real touch point in the first coordinate system.

6. The touch screen according to claim 5, characterized in that, The infrared touch screen includes an infrared emitting and receiving light group, which includes at least multiple sets of infrared emitting lights and infrared receiving lights arranged opposite each other, wherein the infrared light emitted by each emitting light can be received by several consecutively arranged receiving lights opposite it. The blocked light determination module includes: The determination submodule is used to determine, based on the signal feedback from the receiving lamp, the light whose received signal strength is less than a predetermined threshold as the light that is blocked by the multi-touch, thereby finding all n blocked light rays; The calculation submodule is used to calculate the slope k and intercept b of each blocked ray in the first coordinate system based on the coordinate values ​​of the emitting and receiving lights of the ray in the first coordinate system.

7. The touch screen according to claim 6, characterized in that, The predetermined threshold is 15% of the light signal intensity that should be received under normal, unobstructed conditions.

8. The touch screen according to claim 5, characterized in that, When the real touch point coordinate determination module records the corresponding coordinate point as cleared, the allowable range is a range where both the horizontal and vertical spacing from the virtual straight line is less than 3% of the side length of the smallest cell of the corresponding coordinate axis.

9. An electronic display device, characterized in that, Including the touch screen as described in any one of claims 5-8.

10. The electronic display device as described in claim 9, characterized in that, The electronic display device is a touch screen all-in-one machine, a smart interactive screen, a smart electronic whiteboard, a smart electronic blackboard, or a smart home appliance.

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