CN105808019B - Contact coordinate detection method for infrared touch screen - Google Patents
Contact coordinate detection method for infrared touch screen Download PDFInfo
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- CN105808019B CN105808019B CN201410854155.1A CN201410854155A CN105808019B CN 105808019 B CN105808019 B CN 105808019B CN 201410854155 A CN201410854155 A CN 201410854155A CN 105808019 B CN105808019 B CN 105808019B
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Abstract
A touch point coordinate detection method for an infrared touch screen is characterized by comprising a step of executing infrared sector scanning, a step of calculating the coordinate of a quasi touch point by using a scanning line, a step of checking a touch point, a step of weighted averaging and a step of transmitting a real touch point. Various scanning lines (including non-orthogonal scanning lines and possibly orthogonal scanning lines) with various slopes can be obtained at one time by the sector scanning technology, so that the number of times of infrared scanning is reduced, the time is saved, and the touch response speed is improved; because the scanning lines used for calculating the coordinate values of the touch points are nearly orthogonal, the correlation among data is small, and the positioning accuracy is improved; more importantly, since the coordinate values calculated from the scan line groups from different orientations are used in calculating the touch point, when the number of the coordinate values is large enough, the result of the weighted average (i.e., the touch point coordinates) can approach the real touch point infinitely, and the accuracy is guaranteed.
Description
Technical Field
The invention relates to a touch point coordinate detection method for an infrared touch screen, a corresponding device, a chip for executing the method and a corresponding infrared touch screen.
Background
The infrared touch screen in the application mainly refers to an infrared interactive multimedia all-in-one machine (hereinafter referred to as an infrared large screen) and an infrared interactive electronic whiteboard (hereinafter referred to as an infrared whiteboard). Infrared coordinate detection (touch point location) principle: the existing infrared large screen or electronic whiteboard realizes touch identification by means of infrared frames arranged around the screen. And a transmitting tube, a receiving tube, a transmitting circuit, a receiving circuit and a control IC for controlling the receiving and transmitting circuit and carrying out centralized processing on signals are integrated on the infrared frame. When a user touches the screen, infrared light emitted by the transmitting tube cannot reach the corresponding receiving tube due to the blockage of a touch object, so that optical signals are lost, and the touch point is positioned by the light loss mechanism. The blocked, missing light rays are called scan lines; the process of sequentially lightening each transmitting tube and the corresponding receiving tube for data acquisition is called infrared scanning; the time to complete one scan is referred to as one scan cycle. The mechanism for realizing the infrared scanning is described in detail in U.S. Pat. No. 5162783(patent number) and Chinese patent 201210226494.6 (FIG. 11), which are incorporated herein by reference.
In the existing infrared touch equipment, regardless of whether a one-to-one or one-to-many infrared frame is used, the touch point is generally positioned by combining orthogonal scanning and non-orthogonal scanning technologies. Chinese patent application No. 200710100010 (reference 1) discloses a one-to-one type of off-axis scanning, see fig. 12. The scheme obtains inclined scanning lines through off-axis scanning, and the real position of a touch point is determined by the inclined scanning lines and orthogonal scanning lines (vertical or horizontal). Patent 201110436294.9 (reference 2) discloses a one-to-many type of scanning, see fig. 13, where the effective reception angle of each receiver tube covers multiple emitter tubes on the opposite side frame, and each point on the screen is covered by the "field of view" of exactly two receiver tubes. For one touch point, after the scanning is completed, 4 groups of scanning lines (each group includes a plurality of scanning lines) on the X axis and the Y axis are obtained.
One coordinate detection in the comparison document 1 needs to perform infrared scanning for many times, and the scanning period may be long. In addition, since the touch objects all have a certain volume and size, they are not necessarily ideal points; therefore, each touch can shield a continuous group of emission tubes to generate a plurality of clusters of scanning lines from different visual angles; therefore, in the sector scanning scheme disclosed in reference 2, the amount of information available for coordinate positioning is multiplied. Since any two straight lines can uniquely calculate one coordinate value, a plurality of different coordinate points can be obtained certainly when different straight line groups are selected for calculation. How to fully utilize the data to reflect the real position of the touch point to the maximum degree becomes a technical problem which needs to be solved.
Disclosure of Invention
The invention aims to provide a data processing scheme for improving the coordinate detection precision of an infrared touch screen aiming at the problems of longer scanning period, large data volume and the like in the prior art.
First aspect of the inventionThe touch point coordinate detection method for the infrared interaction equipment comprises the following steps:
performing infrared sector scanning to obtain a plurality of scanning lines which are not orthogonal or possibly orthogonal; combining every two scanning lines to calculate the coordinate of a quasi-touch point; a quasi-touch point detection step of using the effective working angle to cover the scanning data of the infrared receiving tube of the detected coordinate point to align whether the touch point causes real shielding or not for detection; and outputting the real touch point to the main control computer or the touch point coordinate of the subsequent processing program.
Optionally, the scanning lines for calculating the coordinates of the touch points are all from infrared transceiving lamps in the same direction of the infrared interaction device.
Optionally, the two lines for calculating the coordinate of any touch point come from the infrared transceiving lamps in the two directions of the infrared interaction device respectively. Further, when it is detected in the touch point detecting step that a certain coordinate point indeed causes light shielding, the coordinate point is marked as a real point; otherwise, the point is eliminated.
Further, the touch point detecting step in the touch point coordinate detecting method further includes a step of averaging a plurality of coordinate values of the same touch point by weight, that is: firstly, judging whether a plurality of touch point coordinates belong to the same touch point, when all the points belong to the same touch point, carrying out weighted average calculation on a plurality of coordinate values and taking a weighted average result as the touch point coordinates.
Further, the step of determining the touch point using the scan lines that are approximately orthogonal includes a step of determining whether two scan lines involved in the coordinate calculation of the touch point are approximately orthogonal: and if the touch points are close to be orthogonal, calculating the coordinates of the touch points, otherwise, not calculating the coordinates of the touch points.
Furthermore, when the scanning lines for calculating the coordinates of the touch points are all from the infrared transceiving lamps in the same direction of the infrared interaction device, an area judgment step is also included before the coordinates of the touch points are calculated, the step firstly judges whether two straight lines which possibly form a scanning line group and are used for calculating the coordinates of the points are positioned in a certain area, and if the two straight lines are positioned in the certain area, group matching calculation is carried out; otherwise, the scan line group is discarded.
According to the touch point coordinate method disclosed by the invention, various scanning lines with various slopes can be obtained at one time through a sector scanning technology, and the touch point coordinate method not only comprises non-orthogonal scanning lines, but also possibly comprises orthogonal scanning lines, so that the infrared scanning times are reduced, the time is saved, and the touch response speed is improved; the touch point coordinates are calculated by adopting the scanning lines which are close to orthogonal (for example, the scanning lines which participate in the touch point coordinate operation are selected from the first direction and the second direction respectively and/or the orthogonal degree judgment is carried out by adopting slope comparison or inner product calculation), so that the relevance among groups of data for calculating the touch point coordinates is reduced, the system error is reduced, the operation efficiency is improved, and the positioning precision is further improved; more importantly, in the technical solution including the step of weighted average operation, since the coordinate values calculated from scan line groups from different orientations are used in calculating the touch points, when the number of the coordinate values is large enough, the result of weighted average (i.e. the touch point coordinates) can approach the real touch point infinitely, and the accuracy is relatively guaranteed.
Second aspect of the inventionIt is characterized in that the control chip internally stores or records the program codes or functional modules which can execute the method and steps in the first aspect of the invention. Furthermore, the chip also comprises a plurality of system memories, and the program codes or the functional modules are burned in the system memories.
Third aspect of the inventionIt is an object of the present invention to provide a touch point coordinate detecting apparatus corresponding to the method or step in the first aspect of the present invention, which includes a sector scanning module, a touch point coordinate calculating module, a touch point verifying module, and a touch point outputting module, wherein:
the sector scanning module is used for executing infrared sector scanning to obtain a plurality of scanning lines, and the scanning lines comprise non-orthogonal scanning lines and possibly orthogonal scanning lines; the touch point coordinate calculation module is used for arranging the obtained scanning lines pairwise to form scanning line groups and calculating the coordinate of a quasi-touch point;
the touch point detection module detects whether the coordinate point is really shielded or not by using the scanning data of the infrared receiving tube of which the effective working angle can cover the coordinate point to be detected, and marks the coordinate point as a real point when the point is detected to really shield the light; otherwise, rejecting the point; and the touch point output module is used for outputting the obtained real touch point to the main control computer or the subsequent processing module. Furthermore, the touch point coordinate detection device also comprises a weighted average calculation module which is arranged between the touch point inspection module and the touch point output module and is used for judging whether the coordinates of a plurality of touch points belong to the same touch point and carrying out weighted average calculation on the coordinate values belonging to the same touch point.
Fourth aspect of the inventionThe touch screen comprises a touch panel and an infrared frame, wherein the touch panel is used for receiving touch signal input, the infrared frame is used for detecting a touch position and outputting the touch position to a main control computer or a subsequent processing program, and the infrared frame is arranged on at least one opposite side of the touch panel; the infrared frame comprises an infrared transmitting tube, an infrared receiving tube, a receiving and transmitting control circuit and a control unit, wherein the infrared transmitting tube and the infrared receiving tube are connected to the receiving and transmitting control circuit, and the receiving and transmitting control circuit is connected to the control unit; the control unit is used for controlling the receiving and sending of the infrared light and processing the collected signals, and is characterized in that the control unit comprises a sector scanning module, a touch point coordinate calculation module, a touch point inspection module and a touch point output module, wherein:
the sector scanning module is used for executing infrared sector scanning to obtain a plurality of scanning lines which not only comprise non-orthogonal scanning lines but also can comprise orthogonal scanning lines;
the touch point coordinate calculation module is used for arranging the scanning lines obtained by scanning pairwise into scanning line groups and calculating the coordinate of a quasi-touch point; the touch point detection module detects whether the coordinate point is really shielded or not by using the scanning data of the infrared receiving tube of which the effective working angle can cover the coordinate point to be detected, and marks the coordinate point as a real point when the point is detected to really shield the light; otherwise, rejecting the point; and the touch point output module is used for outputting the obtained real touch point to the main control computer or the subsequent processing module. Furthermore, the infrared touch screen further comprises a weighted average module, wherein the weighted average module is positioned between the touch point detection module and the touch point output module and is used for judging whether the coordinates of the multiple touch points belong to the same touch point and carrying out weighted average calculation on the coordinate values belonging to the same touch point.
The technical scheme of the invention is explained in detail in the following by combining the drawings and the specific embodiments of the specification.
Drawings
FIG. 1: a coordinate detection cycle flow chart;
FIG. 2: sector scanning flow chart;
FIG. 3: a coordinate determination flowchart;
FIG. 4: a coordinate inspection flowchart;
FIG. 5: example 1 infrared frame schematic;
FIG. 6: example 2 infrared frame schematic;
FIG. 7: opening part or all of the lamp tube schematic diagram;
FIG. 8: an orthogonal judgment flow chart;
FIG. 9: an inner product calculation explanatory diagram;
FIG. 10: an area judgment explanatory diagram;
FIG. 11: background art 1 accompanying drawings;
FIG. 12: background art 2 accompanying drawings;
FIG. 13: background art 3 figure.
DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION
The invention relates to a touch point coordinate detection method and a corresponding device applied to an infrared touch screen, the method is suitable for interactive display equipment comprising the infrared touch screen, such as an infrared large screen, an infrared electronic whiteboard and the like, and the interactive display equipment is shown in figure 11. The emission control circuit is connected to the emission tube and the control unit and is used for driving the infrared emission tube to emit infrared rays; the receiving control circuit is connected to the receiving tube and the control unit and used for driving the infrared receiving tube to receive infrared rays and sample; the control unit is used for carrying out coordination control on the receiving and sending of the infrared light and processing the collected signals so as to determine the position of the touch point. All embodiments in this specification have the basic structure described in this paragraph, and are not described in detail when describing specific embodiments.
In addition, the same reference numerals in the embodiments and the drawings denote the same steps or modules in different embodiments.Preference is given to Practice of
Example 1
The present embodiment relates to a single-pair-frame infrared electronic whiteboard, as shown in fig. 5 (in the figure, black squares represent receiving tubes, and a plurality of infrared emitting tubes (not shown in the figure) are installed between every two black receiving tubes at equal intervals (6 mm)), the electronic whiteboard includes only a pair of infrared frames, and the two infrared frames are arranged on a pair of opposite sides of a touch area of the electronic whiteboard, and the orientations are aligned.
As shown in fig. 1a, a complete touch point coordinate detection process of this embodiment includes a sector scanning step 10, a coordinate determining step 20, a coordinate checking step 30, a weighted average step 40, and a touch point output step 50:
a sector scanning step 10 for performing infrared sector scanning to obtain a plurality of scanning lines that include both non-orthogonal and possibly orthogonal scanning lines;
the coordinate determination step 20 is used for combining every two scanning lines to calculate a plurality of quasi-touch point coordinates;
the coordinate inspection step 30 is used for judging the authenticity of the plurality of point coordinates obtained in the coordinate determination step so as to eliminate ghost points;
the weighted average step 40 is used for carrying out weighted average calculation on a plurality of coordinate values of one touch point to obtain real touch point coordinates;
and the output display step 50 is used for outputting the real touch point coordinates to the main control computer or a subsequent processing module.
Fig. 2 is a flowchart of the sector scanning step 10 in fig. 1a, and as can be seen from fig. 2, the sector scanning step 10 in this embodiment includes a step 101 of sequentially lighting each transmitting tube, a step 102 of opening a receiving tube having an effective working angle capable of covering the currently lighted infrared transmitting tube simultaneously with the step 101, and a step 103 of recording and analyzing the photoelectric signal received by the receiving tube to obtain a scanning line. Wherein, take two touch points as an example: in step 101, infrared light emitted by any one of the emitting tubes (except for a very small number of emitting tubes at the edge) can be received by four opposite receiving tubes (that is, the number of the receiving tubes capable of covering most of the emitting tubes on the opposite frame is four); during scanning, sequentially lightening each transmitting tube and simultaneously opening 4 receiving tubes on the opposite side frame to receive light (step 102); step 103, judging the received electric signal, and if the electric signal is smaller than a threshold value set in the system, considering that the light is shielded by the touch point to obtain a scanning line; each shielded receiving tube can detect a plurality of scanning lines, the invention selects the connecting line of the middle point of the connecting line of the transmitting tube corresponding to the plurality of scanning lines detected by a certain receiving tube and the receiving tube as the scanning line participating in the coordinate calculation (step 20) of the touch point (in principle, the positioning of the touch point can be realized by selecting any one scanning line, in the embodiment of the specification, the middle point of the connecting line of the transmitting tube corresponding to the plurality of scanning lines and the connecting line of the receiving tube are all adopted as the scanning line participating in the coordinate calculation of the quasi touch point in the step 20, furthermore, the coordinate values of the plurality of shielded transmitting tubes obtained by scanning the scanning group can be further operated (such as weighted average value calculation) to reflect the real position of the touch point as much as possible, or further, the waveform variation amplitude of the scanning group can be taken into consideration to synthesize the abscissa information of the shielded transmitting tubes, further improving the accuracy of the positioning); based on this mechanism, l is obtained in the present example1-l8Eight scan lines (see fig. 5).
Fig. 3 is a flowchart of the coordinate determining step 20 in fig. 1a, and it can be seen from fig. 3 that the coordinate determining step 20 in this embodiment includes a sub-step 201 of sequentially selecting each scan line on the X axis (in the first direction) and a step 202 of calculating a coordinate point by using the selected scan line and the other scan lines on the X axis to form a pair of scan lines. With touch point P (x) in FIG. 5p，yp) And Q (x)q，yq) For example, touch point P (x)p，yp) A co-formation denoted by1-l44 scan lines of (1), touch point Q (x)q，yq) A co-formation denoted by5-l84 scan lines, 8 lines are arranged to calculate the point coordinates
For each scan line group, a total of about 28 coordinate points can be obtained (the parallel lines have no intersection, and the intersection may fall off the screen, and has no practical meaning), and then step 30 is performed. The coordinate points obtained in step 20 may also be referred to as quasi-touch points because they include both true touch points and ghost points. The ghost points are also referred to as pseudo touch points in reference 1 (patent application No. 200710100010).
As shown in fig. 4, in step 30, when checking the coordinate point, first, a plurality of pairs of transceiver tubes capable of covering the checked coordinate point with effective working angles are selected, and then the infrared scanning data is "checked" to determine whether the calculated coordinate point causes real occlusion, if so, the point is an actual touch point, otherwise, the point is a "ghost point", and the ghost point is to be removed. In this example due to the scan lines l coming from different orientations1-l4Together may be arranged into
A pair of scan lines, and thus, each touch point P (x)p，yp) And Q (x)q，yq) There are about 6 sets of coordinate values, and further processing of sets of coordinate values belonging to a touch point is required.
As shown in fig. 1a, weightingThe averaging step 40 is used for performing a weighted average calculation on a plurality of coordinate values of the same touch point to obtain a real touch point coordinate P (x)p，yp) And Q (x)q，yq) (ii) a Namely: firstly, judging whether a plurality of touch point coordinates belong to the same touch point, when each point belongs to the same touch point, carrying out weighted average calculation on the plurality of coordinate values belonging to the same touch point, and taking the weighted average result as the final touch point coordinate. Because the point coordinates calculated by each scanning line pair from different directions surround the real touch point, the coordinate values after weighted average can approach the center of the real touch point infinitely along with the increase of the scanning line pairs, and the accuracy is relatively guaranteed. Since the method belongs to a conventional data processing method, only the meaning of the method when the method is used for infrared touch screen coordinate positioning is simply introduced, and further discussion on the mechanism is not needed. In particular, one straightforward way of weighted average calculation is direct averaging.
As shown in FIG. 1a, a touch point output step 50 is used to obtain touch point coordinates P (x)p，yp) And Q (x)q，yq) And outputting the touch point to a computer connected to the electronic whiteboard, and displaying the touch point (such as generating a track) or performing further processing (such as calling a function module) by the computer. If the method is used for the infrared large screen, step 50 is used for directly outputting the detected touch points to the large screen host or the computer connected to the large screen, and then the large screen host or the computer connected to the large screen performs corresponding processing on the touch operation. Or, if the infrared electronic whiteboard and the infrared large screen are provided with a main control board, and the functional modules corresponding to the steps in fig. 1a are stored or burned in the main control board, the touch point outputting step 50 is configured to output the real touch point coordinates to a subsequent processing module in the main control board.
More specifically, in step 20, the first formula may be used to calculate the intersection point of any two lines (scan line group), or other formulas may be derived to calculate the intersection point of the scan line group according to the specific structures of the touch area and the infrared frame, for example, two straight lines are directly used to form an equation set or a matrix is used to solve the intersection point.
The formula I is as follows:
the first formula explains that: as shown in FIG. 5, the touch points P (x, y) are collectively denoted as l1-l44 scanning lines of (a), y0Representing the length of the touch screen area, point O representing the corner point (origin of coordinates) of the lower left corner of the touch area, x1、x3、x4And x7Respectively representing the abscissas, x, of four receiving tubes2、x5、x6And x8Respectively, the abscissas of the four shielded emitter tubes.
It should be noted that in some other embodiments, if there is only one pair of scan lines for calculating the coordinate value of each touch point, that is, there is only one set of touch point coordinates calculated in step 30, the touch point will be uniquely determined by the pair of scan lines, so that step 40 of weighted averaging multiple sets of coordinate values belonging to the same touch point is omitted. Alternatively, although there are more than one pair of scan line groups (e.g. 6 pairs in the preferred embodiment 1) for calculating the coordinate value of each touch point, only one pair is selected for calculating the coordinate value, and then the touch point will be uniquely determined by the selected pair of scan lines, and step 40 may also be omitted. This applies to the other embodiments in the present specification as well.
Fig. 6 is an infrared structural diagram of a preferred embodiment 2 of the present invention, in this embodiment, a "four-side buried" type infrared frame is adopted, the infrared frames with aligned orientations are disposed on four sides of a touch area, black squares in the drawing represent infrared receiving tubes, white squares represent infrared emitting tubes (not shown in fig. 6), a plurality of infrared emitting tubes are disposed at equal intervals (5mm) between the infrared receiving tubes, and any point on a screen (touch area) can be simultaneously covered by two receiving tubes on an X axis (first direction) and effective "views" of two receiving tubes on a Y axis (second direction). When the coordinates are detected, any touch point can be positioned by four scanning lines.
The implementation method of this embodiment is similar to that of the preferred embodiment 1, and the difference is that the coordinate determination step 20 includes: select in turn
Substep 201' of taking each scan line on the X-axis (first direction); and the number of the first and second groups,
and a step 202' of calculating coordinate points by using the selected scanning lines in the first direction and the selected scanning lines in the Y axis (the second direction) to form pairs of scanning lines.
Taking the touch points T1 and T2 in FIG. 6 as examples, the sum of the touch points l can be obtained after the sector scan is completed1-l8For the point coordinates calculation, 4 lines l in the first direction (X axis) are formed1、l2、l5、l6Sequentially with four scanning lines l in the second direction (Y axis)3、l4、l7、l8Are arranged into
For each scan line group, a total of about 16 coordinate points can be obtained, and then step 30 is performed.
It should be noted that, in this embodiment, only the scan line group consisting of the scan lines in the first direction and the scan lines in the second direction is used to calculate the possible touch point coordinates, such as i between the scan lines in the same direction1、l2、l5、l6And l3、l4、l7、l8No combination calculations are made in between. This is because, when calculating the intersection of two straight lines, the closer the two straight lines are to being orthogonal, the more accurate the coordinates of the intersection are (because the correlation between data is low).
In step 20 of this embodiment, any one set of formula in the second formula may be used to calculate the intersection point of any two other lines (scan line group), or other formulas may be derived to calculate the intersection point of the scan line group according to the specific structures of the touch area and the infrared frame, for example, two straight lines are directly used to form an equation set or a matrix is used to solve the intersection point.
The formula II is as follows:
The second formula explains that: touch points T1(x, y) in FIG. 6 together form l1-l4Four scanning lines, x0，y0Representing the length and width of the touch screen area, point O representing the corner point (origin of coordinates) at the lower left corner of the touch area, (x)2，0)、(x4，y0)、(0，y2) And (x)0，y4) Coordinates of four receiving tubes are respectively expressed, (x)1，0)、(x3，y0)、(0，y1) And (x)0，y3) Respectively representing the coordinates of the four transmit tubes that are occluded.
In another embodiment of the present invention, the difference from the preferred embodiment 2 is that the coordinate determination step 20 further includes an orthogonality judgment step, as shown in fig. 8, which first judges orthogonality of two straight lines that are likely to constitute scan line groups for point coordinate calculation, then pairs and calculates scan line groups that satisfy the orthogonality condition set by the system, and discards those scan line groups that do not satisfy the orthogonality condition. The orthogonality determination may be performed by slope comparison (for example, the difference between the slopes is greater than a certain value) or by a method of calculating an inner product of vectors as shown in fig. 9, where in fig. 9, vectors AC and BD respectively represent one scan line, and AC ═ d-b) i + y0j，BD＝(c-a)i+y0j, the dot product of vectors AC and BD is:
if AC ⊥ BD, the dot product is zero, i.e.:
therefore, the orthogonality of the two scanning lines can be judged according to whether the inner product of the two scanning lines is close to zero or smaller than a certain threshold value. Only scanning line groups with inner products smaller than a certain value are adopted to calculate the point coordinates, and those line groups which are close to parallel are discarded. Because a large number of scanning line groups which are close to parallel are abandoned, not only the calculation precision is improved, but also the calculation amount is greatly reduced, and the performance of the system is improved. This method is applicable to all embodiments of the present invention.
In another embodiment of the present invention, the difference from the preferred embodiment 1 is that the coordinate determining step 20 further includes a region determining step, which first determines whether two straight lines that are likely to form a scanning line group for point coordinate calculation are located in a certain region, and if so, performs group matching calculation; otherwise, the scan line group is discarded. In preferred embodiment 1 comprising1For example, since the same as l is possible1The scan line for solving the actual touch point coordinate necessarily exists in the same position as the touch point coordinate1Adjacent and effective working angle of which can be compared with1Those receiving tubes that overlap are in the scan line detected, so1The coordinate detection can be completed only by solving the scanning line group formed by the scanning lines detected by the receiving tube in the dotted line frame in fig. 10, and the missing detection of the touch points can not occur. In particular, the scan lines that can be subjected to the point coordinate solving operation with a certain straight line constituting the scan line group should be those scan lines detected by the receiver tubes that can be covered by the effective working angles of the "receiver tubes" at which the two end points are located (the receiver tube at one end point is true, and the other may be assumed). When the screen is large and/or the distance between each touch point is long, the touch screen is practicalThe technical scheme in the embodiment can greatly reduce the times of coordinate solving operation, the number of generated ghost points and the judgment times of eliminating ghost points, can reduce the reaction time to a certain extent, and improves the operation efficiency. In addition, in some other embodiments, the coordinate determining step may also include both the orthogonality determining step and the area determining step.
It should be noted that:
each touch point in example 1 is covered by approximately four receiving tubes from different orientations (distributed in the same direction), and each touch point in example 2 is covered by four receiving tubes from different directions (two first directions, two second directions); in other embodiments, different arrangements of the transmitting and receiving lamp tubes may be adopted, and theoretically, the detection of the touch point can be realized as long as the number of the receiving tubes covering any point on the screen exceeds 2.
In the above embodiments, a pair of multi-type infrared frames is adopted, that is: the infrared frames on the two sides of the touch area are provided with transmitting tubes and receiving tubes, the transmitting tubes are densely arranged, the receiving tubes are sparsely arranged, and the effective working angle of each receiving tube can cover a plurality of opposite transmitting tubes; the receiving tubes are arranged densely, the transmitting tubes are arranged sparsely, and the effective working angle of each transmitting tube can cover a plurality of opposite receiving tubes. When the method disclosed by the invention is applied to the structure, other steps can be the same except that the infrared sector scanning is slightly different. The sector scanning step in this case is: a step 101 'of opening each receiving tube in turn, a step 102' of opening the transmitting tube with an effective working angle capable of covering the currently opened infrared receiving tube at the same time of the step 101', and a step 103' of recording and analyzing photoelectric signals received by the receiving tubes to obtain scanning lines. In addition, the method disclosed by the invention can also be applied to the traditional one-to-one infrared frame, and in this case, the steps can be the same except that the infrared sector scanning is slightly different. As shown in fig. 7, black represents a receiving tube, white represents a transmitting tube, and the following steps are performed during infrared scanning: step 101 'of opening each transmitting tube in turn, step 102' of opening a receiving tube with an effective working angle capable of covering the currently opened infrared transmitting tube simultaneously with step 101 'and step 103' of recording and analyzing photoelectric signals received by the receiving tube to obtain scanning lines.
In addition to the above scanning sequence or scanning logic, other scanning sequences or scanning logic may be applied to complete the infrared scanning, and the object of the present invention can be achieved as long as a plurality of scanning lines, which reflect the actual position of the touch point, including non-orthogonal scanning lines and possibly orthogonal scanning lines can be obtained by scanning.
In addition, in the sector scanning step 102 or 102' or 102 ″ of each of the above embodiments, after any one of the transmitting tubes or receiving tubes is opened, all the receiving tubes or transmitting tubes capable of covering the transmitting tube or receiving tube by an effective working angle are opened at the same time. As shown in fig. 7, the receiver tubes within the 34 ° angle range (effective working angle) can receive the infrared light emitted from the emitter tube at the opposite vertex, and in consideration of the operation speed and the system load, when the data amount is enough to realize the touch point positioning, only the receiver tubes within the 17 ° range or the receiver tubes between the 17 ° range and the 34 ° range on the opposite receiving frame can be opened (this case has higher accuracy because the scanning lines for calculating the coordinates of the touch point are closer to orthogonal).
In addition, the coordinate detection method disclosed by the invention can be widely applied to various infrared structural products introduced in the specification and various deformation or replacement which is not introduced and is made without departing from the principle of the invention and/or the realization principle of the infrared touch device, such as the case that infrared transmitting and receiving lamp tubes are arranged at unequal intervals or the case that a one-to-one frame and a one-to-many frame are arranged in a mixed manner and the case of other irregular infrared frames (such as an annular infrared frame).
Corresponding to the above methods and steps, the invention also provides a touch point coordinate detection device applied to the infrared touch screen, which comprises a sector scanning module, a touch point coordinate calculation module, a touch point inspection module and a touch point output module, wherein: the sector scanning module is used for executing infrared sector scanning to obtain a plurality of scanning lines, and the scanning lines comprise non-orthogonal scanning lines and possibly orthogonal scanning lines; the touch point coordinate calculation module is used for arranging the obtained scanning lines pairwise to form scanning line groups and calculating the coordinate of a quasi-touch point; the touch point detection module detects whether the coordinate point is really shielded or not by using the scanning data of the infrared receiving tube of which the effective working angle can cover the coordinate point to be detected, and marks the coordinate point as a real point when the point is detected to really shield the light; otherwise, rejecting the point; and the touch point output module is used for outputting the obtained real touch point to the main control computer. Furthermore, the touch point coordinate detection device also comprises a weighted average calculation module which is arranged between the touch point inspection module and the touch point output module and is used for judging whether the coordinates of a plurality of touch points belong to the same touch point and carrying out weighted average calculation on the coordinate values belonging to the same touch point.
The above-mentioned methods and steps are generally performed by a control unit as shown in fig. 1b, which is connected to the transmitting and receiving circuits of the infrared touch screen for controlling the transmission and reception of infrared light and processing the collected data. Specifically, the control unit may be represented as a single chip microcomputer or a control motherboard integrated in the infrared frame or existing as an independent module, and has at least one data transmission interface connected to the receiving circuit and the transmitting circuit, and a data processing unit, and the control unit includes a sector scanning module, a touch point coordinate calculating module, a touch point checking module, and a touch point output module, where: the sector scanning module is used for executing infrared sector scanning to obtain a plurality of scanning lines, and the scanning lines comprise non-orthogonal scanning lines and possibly orthogonal scanning lines; the touch point coordinate calculation module is used for arranging the obtained scanning lines pairwise to form scanning line groups and calculating the coordinate of a quasi-touch point; the touch point detection module detects whether the coordinate point is really shielded or not by using the scanning data of the infrared receiving tube of which the effective working angle can cover the coordinate point to be detected, and marks the coordinate point as a real point when the point is detected to really shield the light; otherwise, rejecting the point; and the touch point output module is used for outputting the obtained real touch point to the main control computer. Furthermore, the control unit also comprises a weighted average module which is positioned between the touch point detection module and the touch point output module and is used for judging whether the coordinates of the multiple touch points belong to the same touch point and carrying out weighted average calculation on the coordinate values belonging to the same touch point.
Further, the control unit further comprises a system memory, and the sector scanning module, the touch point coordinate calculation module, the touch point inspection module, the weighted average module and the touch point output module are stored or burned in the system memory. Furthermore, the control unit also comprises a plurality of other communication interfaces, and the sector scanning module, the touch point coordinate calculation module, the touch point inspection module, the weighted average module and the touch point output module can also be stored in various types of computer-readable storage media and can be called by the control unit through the communication interfaces of the control unit or integrated in the control unit; the control unit is in data transmission with the external equipment through the communication interface.
While the technical solutions and innovative concepts of the present invention have been described in detail with reference to the embodiments and the accompanying drawings, it should be understood by those skilled in the art that the embodiments and the accompanying drawings disclosed in the specification are not intended to limit the scope of the present invention, and any substitutions, modifications, omissions, changes, deletions, substitutions and the like that do not depart from the spirit of the inventive concepts and the innovative concepts of the present invention are included in the scope of the present invention. The claims are to be regarded as illustrative in nature and not as restrictive in any way as the preferred embodiments described in the specification.
Claims (22)
1. A touch point coordinate detection method for an infrared touch screen is characterized by comprising the following steps:
performing infrared sector scanning to obtain a plurality of scanning lines which are not orthogonal or possibly orthogonal;
judging whether two straight lines which possibly form a scanning line group and are used for calculating point coordinates are positioned in a certain area, and if so, performing group matching calculation; otherwise, the coordinate calculation of the quasi-touch point is not carried out;
the pairing calculation comprises: combining every two scanning lines to calculate the coordinate of a quasi-touch point, wherein the scanning lines are connecting lines between the connecting middle points of the transmitting tubes and the receiving tubes, which correspond to a plurality of scanning lines detected by a certain receiving tube;
a quasi-touch point detection step of using the effective working angle to cover the scanning data of the infrared receiving tube of the detected coordinate point to align whether the touch point causes real shielding or not for detection;
and a touch point output step of outputting the real touch point.
2. The method as claimed in claim 1, wherein the scan lines for calculating the coordinates of the quasi-touch points are all from the infrared transceiver lamps in the same direction of the infrared touch screen.
3. The touch point coordinate detection method for the infrared touch screen as claimed in claim 1, wherein the two lines for calculating the coordinate of any quasi-touch point are respectively from the infrared transceiving lamps in two directions of the infrared touch screen.
4. The touch point coordinate detection method for the infrared touch screen according to claim 3, wherein the step of calculating the quasi touch point coordinates using the scan lines comprises the step of calculating the touch point coordinates with each scan line in the first direction and a part or all of the scan lines in the second direction, respectively.
5. The contact coordinate detection method for the infrared touch screen according to any one of claims 1 to 4, wherein the infrared touch screen is a one-to-one type or a one-to-many type infrared transceiver.
6. The touch point coordinate detection method for the infrared touch screen according to any one of claims 1 to 4, wherein the infrared sector scanning step is:
sequentially lightening each infrared emission tube according to a certain sequence; and opening all or part of receiving tubes covering the transmitting tube at the effective working angle and collecting data while lighting each transmitting tube.
7. The touch point coordinate detection method for the infrared touch screen according to claim 5, wherein the infrared sector scanning step is: sequentially lightening each infrared emission tube according to a certain sequence; and opening all or part of receiving tubes covering the transmitting tube at the effective working angle and collecting data while lighting each transmitting tube.
8. The contact coordinate detecting method for the infrared touch screen according to any one of claims 1 to 4, wherein the quasi-touch point detecting step marks as a real point when it is detected that the detected coordinate point does cause light obstruction; otherwise, the point is eliminated.
9. The touch point coordinate detecting method for an infrared touch screen according to any one of claims 1 to 4, wherein the touch point coordinate detecting method further comprises a weighted average step of determining whether the coordinates of the plurality of touch points belong to the same touch point and then performing a weighted average calculation on the coordinate values belonging to the same touch point, which is provided after the quasi touch point detecting step.
10. The method as claimed in claim 9, wherein the determining whether the touch point coordinates belong to the same touch point is performed by checking whether the touch point coordinates are located in the same area or are spaced apart from each other by a distance less than a threshold value.
11. The touch point coordinate detection method for the infrared touch screen according to claim 9, wherein the weighted average calculation in the weighted average calculation of the plurality of coordinate values belonging to the same touch point is an average value calculation.
12. The touch point coordinate detecting method for an infrared touch screen according to claim 8, wherein the touch point coordinate detecting method further comprises a weighted average step disposed after the quasi touch point detecting step, the weighted average step first determining whether the coordinates of the plurality of touch points belong to the same touch point, and then performing weighted average calculation on the coordinate values belonging to the same touch point.
13. The method as claimed in claim 12, wherein the determining whether the touch point coordinates belong to the same touch point is performed by checking whether the touch point coordinates are located in the same area or are spaced apart from each other by a distance less than a threshold value.
14. The touch point coordinate detection method for the infrared touch screen according to claim 12, wherein the weighted average calculation in the weighted average calculation of the plurality of coordinate values belonging to the same touch point is an average value calculation.
15. The touch point coordinate detection method for an infrared touch screen according to any one of claims 1 to 4, wherein the step of determining the coordinates of the touch point using the scan lines further comprises a step of determining whether the two scan lines involved in the calculation of the coordinates of the touch point are nearly orthogonal: and if the touch points are close to be orthogonal, calculating the coordinates of the touch points, otherwise, not calculating the coordinates of the touch points.
16. The method as claimed in claim 15, wherein in the step of determining whether the two scan lines involved in the calculation of the coordinates of the touch point are approximately orthogonal, the determination condition is that an inner product of vectors formed by the two scan lines is approximately zero or not greater than a threshold.
17. An infrared touch screen comprises a touch panel and an infrared frame, wherein the touch panel is used for receiving touch signal input, the infrared frame is used for detecting touch point coordinates and outputting the touch point coordinates to a subsequent processing module and/or a main control computer, and the infrared frame is arranged on at least one opposite side of the touch panel; the infrared frame comprises an infrared transmitting tube, an infrared receiving tube, a receiving and transmitting control circuit and a control unit, wherein the infrared transmitting tube and the infrared receiving tube are connected to the receiving and transmitting control circuit, and the receiving and transmitting control circuit is connected to the control unit; the control unit is used for controlling the transceiving control circuit and processing the acquired signals, and is characterized in that the control unit comprises a sector scanning module, a touch point coordinate calculation module, a touch point inspection module and a touch point output module, wherein:
the sector scanning module is used for executing infrared sector scanning to obtain a plurality of scanning lines, and the scanning lines comprise non-orthogonal scanning lines and possibly orthogonal scanning lines;
the touch point coordinate calculation module is used for judging whether two straight lines which possibly form a scanning line group and are used for calculating point coordinates are positioned in a certain area, and if the two straight lines are positioned in the certain area, the group matching calculation is carried out; otherwise, the coordinate calculation of the quasi-touch point is not carried out; the pairing calculation comprises: arranging the obtained scanning lines pairwise to scanning line groups, and calculating the coordinates of quasi-touch points, wherein the scanning lines are the connecting lines between the connecting middle points of the transmitting tubes and the receiving tubes, which correspond to a plurality of scanning lines detected by a certain receiving tube;
the touch point detection module detects whether the coordinate point is really shielded or not by using the scanning data of the infrared receiving tube of which the effective working angle can cover the coordinate point to be detected, and marks the coordinate point as a real point when the point is detected to really shield the light; otherwise, rejecting the point;
and the touch point output module is used for outputting the obtained real touch point.
18. The infrared touch screen according to claim 17, wherein the control unit further comprises a weighted average module, which is located between the touch point detection module and the touch point output module, and is configured to determine whether the coordinates of the multiple touch points belong to the same touch point, and perform a weighted average calculation on the coordinate values belonging to the same touch point.
19. A control unit for an infrared touch screen comprises at least one data transmission interface, a memory unit and a data processing unit, wherein the data transmission interface is connected with a receiving circuit and a transmitting circuit, the memory unit is characterized in that the memory unit comprises a sector scanning module, a touch point coordinate calculating module, a touch point checking module and a touch point output module, and the control unit comprises:
the sector scanning module is used for executing infrared sector scanning to obtain a plurality of scanning lines, and the scanning lines comprise non-orthogonal scanning lines and possibly orthogonal scanning lines;
the touch point coordinate calculation module is used for judging whether two straight lines which possibly form a scanning line group and are used for calculating point coordinates are positioned in a certain area, and if the two straight lines are positioned in the certain area, the group matching calculation is carried out; otherwise, the coordinate calculation of the quasi-touch point is not carried out; the pairing calculation comprises: arranging the obtained scanning lines pairwise to scanning line groups, and calculating the coordinates of quasi-touch points, wherein the scanning lines are the connecting lines between the connecting middle points of the transmitting tubes and the receiving tubes, which correspond to a plurality of scanning lines detected by a certain receiving tube;
the touch point detection module detects whether the coordinate point is really shielded or not by using the scanning data of the infrared receiving tube of which the effective working angle can cover the coordinate point to be detected, and marks the coordinate point as a real point when the point is detected to really shield the light; otherwise, rejecting the point;
and the touch point output module is used for outputting the obtained real touch point.
20. The control unit of claim 19, wherein the memory unit further comprises a weighted average module, disposed between the touch point checking module and the touch point output module, for determining whether the coordinates of the touch points belong to a same touch point and performing a weighted average calculation on the coordinates of the touch points.
21. The utility model provides a contact coordinate detection device for infrared touch-sensitive screen, includes sector scanning module, touch point coordinate calculation module, touch point check module and touch point output module, wherein:
the sector scanning module is used for executing infrared sector scanning to obtain a plurality of scanning lines, and the scanning lines comprise non-orthogonal scanning lines and possibly orthogonal scanning lines;
the touch point coordinate calculation module is used for judging whether two straight lines which possibly form a scanning line group and are used for calculating point coordinates are positioned in a certain area, and if the two straight lines are positioned in the certain area, the group matching calculation is carried out; otherwise, the coordinate calculation of the quasi-touch point is not carried out; the pairing calculation comprises: arranging the obtained scanning lines pairwise to scanning line groups, and calculating the coordinates of quasi-touch points, wherein the scanning lines are the connecting lines between the connecting middle points of the transmitting tubes and the receiving tubes, which correspond to a plurality of scanning lines detected by a certain receiving tube;
the touch point detection module detects whether the coordinate point is really shielded or not by using the scanning data of the infrared receiving tube of which the effective working angle can cover the coordinate point to be detected, and marks the coordinate point as a real point when the point is detected to really shield the light; otherwise, rejecting the point; and the touch point output module is used for outputting the obtained real touch point.
22. The touch coordinate detecting device for an infrared touch screen according to claim 21, further comprising a weighted average calculating module disposed between the touch point verifying module and the touch point outputting module, for determining whether the coordinates of the plurality of touch points belong to the same touch point and performing a weighted average calculation on the coordinate values belonging to the same touch point.
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| CN107783695B (en) * | 2017-09-27 | 2021-01-12 | 深圳市天英联合教育股份有限公司 | Infrared touch screen arrangement method and device and display equipment |
| CN110262698A (en) * | 2019-06-27 | 2019-09-20 | 深圳市康冠商用科技有限公司 | A kind of infrared touch panel scan method and relevant apparatus |
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