[0039] According to the multi-touch positioning method of the present invention, for the touch screen system shown in Figure 1, when touch events 102 and 103 occur at the same time, the first touch event is recorded according to the difference in the occurrence time of touch events 102 and 103. The coordinates of the location are (x1, y1), register and save the touch point. When the second touch event is superimposed on the first touch event, the system will detect multiple sets of position coordinates (x1, x2, y1, y2) to determine that a new touch point has been added, by comparing the existing registration Point position coordinates (x1, y1), excluding the possibility of other coordinates (x1, y2), (x2, y1), and thus determine the newly added touch point coordinates as (x2, y2), so that two touches can be distinguished Points 102,103.
[0040] Similarly, for the touch screen system shown in FIG. 2, the two touch points 202 and 203 can be distinguished easily by applying the method of the present invention. The methods and steps are as described above, and will not be repeated here.
[0041] Fig. 3 is a specific embodiment of the application of the method of the present invention where two points are touched at the same time. This situation usually occurs in occasions such as simultaneous writing by multiple people or multi-player games. As shown in FIG. 3, 301 is a touch screen device. The positioning detection technology adopted by the touch screen device may be infrared technology, camera positioning technology or other technologies. 302 is a touch point, and its touch operation track is 303. In another location, another touch point 304 is also operated on the same touch screen. The touch point 304 may come from the same user or from a different user. 306 is a touch position of the touch point 304 at a certain moment, and its operation track It's 305. In the touch screen in the prior art, since it can only respond to a single-point touch, when only one touch point 302 or 304 is operated on the touch screen, the touch screen can work normally. As for the situation where the two touch points are touched at the same time as shown in the figure, the touch screen will not be able to report the correct touch location, resulting in an incorrect response.
[0042] The process by which the touch event is judged and recognized will be described below in conjunction with FIG. 3.
[0043] Referring to Figure 3, touch points 302 and 304 are operated on the touch screen at the same time. When recognizing touch points 302 and touch points 304, the detection system can first determine the touch event of a touch point and register its coordinate position according to the sequence of the touch events. And save it; in the next calculation cycle, according to the calculated touch coordinate value, compare it with the registered touch coordinate value, separate the touch position coordinate value of another touch point from the calculated touch coordinate value, and also change it Register and save. In this way, the touch screen system has completed the distinction and recognition of the two touch points, and then can track and recognize the movement trends of multiple simultaneous touch points according to the change of the touch position coordinates.
[0044] 4 is a schematic flowchart of a method for implementing multi-touch according to an embodiment of the present invention, which mainly includes the following steps:
[0045] a. The touch screen detection system measures the touch signal, judges the signal change, and calculates the position coordinate ∑(X, Y) where the touch event occurs. It may contain one or more sets of coordinate data, which is a collection of coordinate data; when necessary, It can also calculate the shape and size of the touch point;
[0046] b. According to the change of the number of position coordinates, judge whether the touch information is single-point touch or multi-point touch. If there is only one set of position coordinate values (X, Y) within a period of time, it is judged as a single-point touch and the touch screen system corresponds Perform various operations of single-point touch, such as writing, clicking, etc., if the detected position coordinate value is more than one set within a period of time, it can be judged that there are multiple touch points, and go to step c;
[0047] c. Compare the change in the number of position coordinates and/or the change in coordinate values detected in this calculation cycle and the previous calculation cycle to determine whether a new touch point is added or a touch point leaves. If a new touch point is added, register New touch point information, record the position coordinates of the new touch point, if the touch point leaves, log off the information of the left touch point, in order to track and identify the position of each touch point, record the position of each touch point in the p-th calculation cycle Coordinates, the first point is recorded as T 1 (Xp, Yp), the second point is recorded as T 2 (Xp, Yp),...... The Nth point is recorded as T n (Xp, Yp);
[0048] d. Compare the changes of the coordinate values (X, Y) detected in this calculation period with the previous calculation period, compare the coordinate values (X, Y) with the current position coordinates of the registered touch points, and judge each touch point Sports
[0049] e. Calculate and determine the touch point whose position has changed, and assign the latest coordinate value to the touch point.
[0050] In this embodiment, the setting is predicted in advance to be the operation of two touch points. In step 3, the identification and registration of the new touch point can be realized by monitoring the change in the number of touch coordinate values. This process is relatively easy. However, if there are more than two touch point operations, since the increase or decrease of the touch point is random, the situation is more complicated. When the touch point is left, a new touch point may be added. The judgment of the new touch point , Registration and deregistration, it is necessary to formulate a targeted plan according to the different occasions or fields of use of the touch screen. Usually, a judgment method or mechanism that is more in line with the actual situation can be determined through trial and error. But fundamentally speaking, for events that seem to occur simultaneously, as long as the detection speed is fast enough, through subdivision, the order of occurrence of the events can always be distinguished.
[0051] As shown in FIG. 5, the method for judging the change of the position coordinate of the touch point in step 5 mainly includes the following steps:
[0052] i. Calculate the coordinate position (X, Y) of the touch position according to the measurement signal.
[0053] ii. Calculate the distance between the coordinate value (X, Y) and the current coordinate of each adjacent touch point, which is the distance from the first point T 1 The distance between is D 1 , And the second point T 2 The distance between D 2 ,..., and the nth point T n The distance between is D n ,then
[0054] D 1 = [ T 1 ( x ) - X ] 2 + [ T 1 ( y ) - Y ] 2 ,
[0055] D 2 = [ T 2 ( x ) - X ] 2 + [ T 2 ( y ) - Y ] 2 ,
[0056]......
[0057] D n = [ T n ( x ) - X ] 2 + [ T n ( y ) - Y ] 2 ,
[0058] In this embodiment, the occurrence of touch events at each touch point is continuous, and the touch point T adjacent to the coordinate value (X, Y) n The judgment method of (x, y) can use the method of detecting the range of coordinate value change or the method of detecting the rate of coordinate value change, that is, the change range of coordinate value in each calculation period is preset, when the value of (X, Y) falls When the coordinate values of certain touch points are within the change range, it can be considered that these touch points are near the coordinate values (X, Y), and it may be that one of the touch points moves. If the touch events occurring at each touch point are non-continuous, judge the touch point T adjacent to the coordinate value (X, Y) n The method of (x, y) should be determined according to the actual use of the touch screen.
[0059] iii. Compare the calculated distance value D 1 , D 2 ,..., D n , Find the minimum value D m , D m =Min(D 1 , D 2 ,...D n ), OK and D m The corresponding touch point T whose position has changed m.
[0060] iv. Replace the touch point T with the smallest distance value with the position coordinates (X, Y) detected in the current calculation cycle m The existing location coordinates.
[0061] After the above calculation, the touch point whose position has changed can be correctly found. The touch coordinates are generated by the movement of the touch point 304, indicating that the touch point 304 has moved from the last coordinate position to the position shown by 306. After correctly identifying the position coordinates of each touch point, various touch operation functions can be defined according to the movement trend of each point. For example, in an application, two touch points move in the opposite direction, which means zoom in operation; two touch points move towards each other, which means zoom out operation; while one touch point does not move, the other touch point moves in an arc, Represents rotating operations and so on. These operating functions can be flexibly defined by the corresponding application software.
[0062] This embodiment enumerates the situation where two touch points are touched at the same time. The touch operation recognition of two or more points can also be carried out according to the above method. First, distinguish each touch point, register and save the position coordinate value, and then The change of the position coordinate value determines the touch point where the position changes. If necessary, it can also detect the shape and size of the touch point, mark and further identify each touch point according to the shape and size.
[0063] The method of the present invention is applicable to various touch screen devices, including various touch screens based on infrared, camera or other technologies as the touch positioning detection technology used, although the touch screen technologies are different in the principle of detecting touch input information However, the technical concept and method of the present invention can be applied to various touch screen systems, regardless of the positioning detection technology adopted by the touch screen.
[0064] The above is only one embodiment of the present invention. In fact, multi-point touch is used in far more occasions than those mentioned in this embodiment; there are only two touch points listed in the embodiment, which can be achieved according to the method of the present invention. There may be two or more touch points, so the protection scope of the present invention is not limited to this, and any insubstantial changes based on the technical solution of the present invention by those skilled in the art are included in the protection scope of the present invention.
