WO2008154792A1

WO2008154792A1 - Infrared touch screen and multi-point touch positioning method

Info

Publication number: WO2008154792A1
Application number: PCT/CN2008/000847
Authority: WO
Inventors: Ruxi Lu; Chunjing Zhou; Junming Li
Original assignee: Vtron Technologies Ltd.
Priority date: 2007-06-15
Filing date: 2008-04-25
Publication date: 2008-12-24

Abstract

An infrared touch screen and multi-point touch positioning method. That is, in at least one detect direction of the touch screen, a beam emitted from an infrared emission component is received and detected by an infrared receiving component, and also received and detected by another infrared receiving component.

Description

Infrared touch screen and multi-touch positioning method

[Technical Field]

The invention relates to an infrared touch screen, in particular to an infrared touch screen and a multi-touch positioning method capable of distinguishing a plurality of touch points and simultaneously operating.

【Background technique】

As an interactive device with simple production process and low production cost, the infrared touch screen has been developed rapidly and has been widely used in many fields. The basic structure of the infrared touch screen is to install a plurality of pairs of infrared emitting and infrared receiving elements in a certain order on a peripheral edge of a display surface suitable for mounting. The transmitting and infrared receiving components form a transmitting and receiving pair in a one-to-one correspondence manner, and form a mutually perpendicular transmitting and receiving array along the edge of the display surface, and each pair of transmitting is respectively turned on in a certain order under the control of the microcomputer system. And an infrared receiving component that detects whether infrared rays between each pair of infrared emitting and infrared receiving elements are blocked, thereby determining whether a touch event occurs. The detailed principles are described in U.S. Patent 5,162,783 and many domestic patents.

In the existing infrared touch screen system, light forms a grid structure on the display surface, and when a touch is detected, the position of the grid node where the touch occurs is determined to calculate the position coordinate at which the touch event occurs. This touch detection mode allows the existing infrared touch screen to receive only a unique set of position coordinate data for a given period of time, so when there is only one touch point, the touch screen can work normally, for two or more touch points At the same time, the system will calculate the wrong position coordinates, resulting in the reported touch location not being the actual touch location.

For the above reasons, the existing infrared touch screen technology will be ineffective in some situations where multi-touch is required, such as multi-player simultaneous games, multiple people writing at the same time, etc., which greatly limits the field of use of the infrared touch screen. At present, there are some solutions for identifying a plurality of touch points by detecting the order in which the touch events occur, but it is easy to occur when there is no relative movement between the plurality of touch points, and no shape size value of the touch points can be referred to. Misjudgment.

In view of the above-mentioned shortcomings of the infrared touch screen system, it is necessary to provide a structure and method that can achieve multi-touch positioning and reduce misjudgment.

[Summary of the Invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a circuit structure and method for an infrared touch screen system that can recognize two or more touch operations and achieve a multi-point simultaneous touch that can also report an effective touch position.

In order to achieve the above object, the present invention proposes three technical solutions based on a general inventive concept. The common features of the three technical solutions are: In at least one detecting direction of the touch screen, an infrared emitting element emits light by an infrared receiving element. The reception detection is also detected by another infrared receiving component.

- 1- Confirmation Technical solution one

A circuit structure for an infrared touch screen system has the following changes in the circuit structure design of the conventional infrared touch screen circuit: In the at least one detection direction of the touch screen, there is a set of infrared emission scanning circuits corresponding to two 3⁄4 infrared receiving scanning circuits In a small local area, a set of infrared emission scanning circuits corresponds to a set of infrared receiving scanning circuits. Thus, a set of receive scanning circuits can be corresponding to two sets of transmit scan circuits at different times. The scanning detection method is: a light emitted by an infrared emitting component in an infrared transmitting scanning circuit is received and detected by an infrared receiving component of a set of infrared receiving scanning circuits, and there is another set of infrared receiving scanning circuits. The infrared receiving component receives the detection. A set of infrared emission scanning circuits includes a plurality of infrared emitting elements, and a set of infrared receiving scanning circuits includes the same number of infrared receiving elements. During operation, the infrared emitting elements of the same scanning circuit are turned on one by one, and the corresponding infrared receiving elements of a set of scanning circuits are also connected one by one to receive.

The reason for adopting this method is as follows: If a plurality of receiving elements in the infrared receiving scanning circuit are simultaneously received, it is necessary to add more analog-to-digital conversion circuits, and at the same time, the single-chip microcomputer is required to simultaneously acquire multiple analog signals, thus making the touch screen circuit The system is complicated, which increases the difficulty of circuit implementation. It is not conducive to the development of touch screens in the direction of miniaturization and portability.

The infrared transmission/reception scanning circuit referred to in the present invention may be an independent circuit board divided by hardware, or may be a circuit unit or a scanning unit which is logically divided on the same circuit board.

Corresponding to the circuit structure, the touch screen algorithm program of the present invention includes a touch point pre-detection algorithm module for determining the touch point range in advance, and can detect the position of the touch point according to the calculation formula by detecting the change of the output value of the corresponding infrared receiving element. Thereby achieving multi-touch positioning.

The circuit structure of the present invention can take the form that: the infrared emitting circuit board has the same total length as the receiving circuit board, and the length of the single infrared transmitting circuit board is twice that of the single receiving circuit board, so that there is one or two receiving circuit boards and one Corresponding to the transmitting circuit board; the corresponding relationship between the infrared emitting element and the infrared receiving element is from the original pair of strains, and one infrared emitting element corresponds to one or two infrared receiving elements, and the corresponding relationship between the infrared emitting element and the infrared receiving element includes positive correspondence A non-positive correspondence of a certain angle, the size of the angle can be determined according to actual needs.

The circuit structure of the present invention may also adopt another form: the number and length of the infrared transmitting circuit board and the infrared receiving circuit board are equal, and the infrared emitting circuit board is divided into a plurality of transmitting scanning units, each of which contains a certain number of The infrared emitting element, the infrared receiving circuit board is also divided into a plurality of receiving scanning units, the number of divided scanning units divided is twice that of the transmitting scanning unit, and one transmitting scanning unit corresponds to one or two receiving scanning units. Thus, the corresponding relationship between the infrared emitting element and the infrared receiving element is also one infrared receiving element corresponding to one or two infrared receiving elements, and the corresponding relationship between the infrared emitting element and the infrared receiving element includes a non-correspondence of positive correspondence and a certain angle, the clip The size of the corner can be determined according to actual needs.

The circuit structure of the present invention can also take another form: the number of infrared transmitting circuit boards and infrared receiving circuit boards The lengths are equal, the infrared emitting circuit board is divided into a plurality of transmitting scanning units, each of the transmitting scanning units includes a certain number of infrared emitting elements, and the infrared receiving circuit board is also divided into the same number of receiving scanning units, and one transmitting scanning unit corresponds to one Or two receiving scanning units. Thus, the corresponding relationship between the infrared emitting element and the infrared receiving element is also one infrared receiving element corresponding to one or two infrared receiving elements, and the corresponding relationship between the infrared emitting element and the infrared receiving element includes a non-correspondence of positive correspondence and a certain angle, the clip The size of the corner can be determined according to actual needs.

As described above, the correspondence between the infrared emitting element and the infrared receiving element, including the positive correspondence and the non-positive correspondence, may be performed by using all or most of the infrared emitting elements and/or the infrared receiving elements to be deflected at a certain angle. By means of this method, the signal of the infrared emitting component can be prevented from interfering with other infrared receiving components symmetrical with the corresponding component, so as to avoid interference with the normal operation of the system and cause misjudgment. This correspondence can also be achieved by selecting a component having a larger emission angle than a normal infrared component.

The circuit board equipped with the infrared emitting element and the circuit board equipped with the infrared receiving component respectively operate according to their respective timings, and the correspondence between the timings can be adjusted as needed; the timing correspondence between the transmitting board and the receiving board includes but is not limited to The following two:

1. The timing of adjacent emitter boards is different, and the timing of the separated emitter boards is the same. In this case, only half of the number of receiving boards has the same timing as the transmitting board. The receiving boards with the same timing can be odd-numbered receiving boards or even-numbered receiving boards, depending on the circuit structure. The design needs; and the timing of the other half of the receiving board needs to change as the corresponding relationship of the transmitting board changes, and the timing of the transmitting board corresponding to the moment remains the same.

Second, the timing of the transmitting board changes stepwise, and the timing of the receiving board is consistent with the corresponding transmitting board timing according to the corresponding relationship.

The purpose of the above-mentioned timing design is to prevent the interference of adjacent infrared components, so that the method of the present invention can be smoothly implemented, and the design principle of the timing is in the patent of the application no. 200610126079. 8 anti-interference type infrared touch device and positioning method There is a detailed description in the file, which is not discussed here.

In order to improve the anti-interference performance of the present invention, in the infrared radiation receiving and receiving array of the infrared touch screen, the infrared transmitting and receiving elements in the horizontal array are different from the infrared transmitting and receiving elements in the vertical array to avoid the infrared emitting between the infrared receiving elements. interference. For example, a 940 nm infrared emission receiving element is used in the lateral array, and an 850 nm infrared emission receiving element is used in the vertical array, so that in the detection area of the corner, adjacent infrared transmitting and receiving elements do not interfere with each other. For the specific method, refer to the infrared touch device of the infrared tube with different frequency of the adjacent infrared scanning unit application number 200610037391.

According to the above circuit structure, in the touch detection algorithm of the touch screen system of the present invention, in addition to the position coordinate calculation program for calculating the position where the touch event occurs, there is also a touch point pre-detection algorithm module capable of detecting the output value of the corresponding infrared receiving element. Change, predetermine the position of the touch point according to the calculation formula. In this way, for simultaneous multi-touch events, the touch screen system can predetermine a certain nearby area while determining the occurrence of a touch event. Whether there are additional touch points in the domain and marking them, combined with further detection data, the position coordinates of the plurality of touch points can be calculated.

Corresponding to the above circuit structure change, the method for realizing multi-touch positioning of the present invention mainly includes the following steps:

1. Start the scan generator to complete the normalization and/or initialization of each infrared receiving component;

2. In one scan cycle, the infrared emitting elements are sequentially turned on, and the corresponding infrared receiving elements are turned on according to a certain timing correspondence;

3. reading the infrared receiving component output value corresponding to the infrared emitting component for the first time, and comparing with the normalized value and/or the initializing value; if the infrared receiving component output value is inconsistent with the normalized value and/or the initializing value, Then determining that a touch event has occurred, marking the location;

4. Read the output value of the next infrared receiving element corresponding to the same infrared emitting element, and compare it with the normalized value and/or the initial value; if the other infrared receiving element outputs the value and the normalized value If the initialization values are inconsistent, it is determined that a touch event occurs in an area where the same infrared emitting element is respectively at an angle with the connection of the two infrared receiving elements, and a touch point pre-detection algorithm is started to mark the area where the touch event occurs, leaving further Judge

5. determining and calculating the position coordinates of each touch point according to the position of the infrared receiving element corresponding to the first time of the infrared emitting element and the position of the area of the pre-detection algorithm mark, according to the output value recorded in the scanning period, and Send coordinate data to the computer for processing;

6. Follow the steps 2 through 5 to start a new cycle.

In step 3, after determining that a touch event has occurred, the touch position coordinates may be calculated using a normal touch position detection algorithm. In step 4, the touch point pre-detection algorithm is used to predetermine the area where the touch event occurs and calculate the possible touch point position. The main steps are as follows:

(1) The output value of another infrared receiving element corresponding to the infrared emitting element is read in accordance with the operation timing of the infrared receiving element.

(2) When it is judged that the output value changes, the area where the touch event occurs is marked, and this area is the area between the infrared receiving elements corresponding to the infrared emitting elements that are turned on at that time.

(3) Use the formula to calculate the possible location of the touch event:

Y= X [sin a . sin ( α + β ) ] /sin P ,

Wherein, X represents the distance between the two infrared receiving elements corresponding to the infrared emitting element, a represents the angle between the line connecting the infrared receiving element and the horizontal line of the infrared emitting element, and P represents the infrared emitting element and the corresponding two infrared rays. The angle between the wires connecting the receiving components.

The above formula can be simplified when the position of the infrared receiving element corresponding to the infrared emitting element for the first time corresponds to the infrared emitting element, and the position of the infrared receiving element corresponding to the infrared emitting element is at an angle with the infrared emitting element. for- Y= X · ctg θ ,

Wherein, X represents the distance between the infrared receiving element corresponding to the infrared emitting element to the infrared receiving element at a certain angle with the infrared emitting element, and the non-positive corresponding infrared receiving element, and Θ represents the connection between the infrared emitting element and the corresponding corresponding infrared receiving element The angle between the line and the infrared emitting element and the line connecting the non-positive corresponding infrared receiving element.

(4) According to further scan detection, the true position of the touch event in the marked area is obtained, and the coordinate value of the possible touch point is calculated using the above formula.

Using the structure and method of the present invention, in some cases, multi-touch positioning can be achieved with only one direction of detection. When it is difficult to calculate the position coordinates of the touch point using one direction touch detection, the two directions can be used to comprehensively judge the data. For example, when the touch point is close to the corner area, the pre-detection algorithm cannot be used or when the plurality of touch points approach the overlap of the mark area in a small area, it is necessary to perform comprehensive judgment in combination with the detection data of the two directions. :

Through the above-mentioned circuit structure change and using the corresponding multi-point positioning algorithm, the infrared touch screen system can distinguish multiple touch points that are simultaneously touched, so that multi-touch positioning can be realized on the infrared touch screen. On the basis of this, further, according to the change of the position coordinates, the moving tendency of each touch point can be determined, according to which different touch operation functions can be defined, for example, the opposite directions of the two touch points indicate that the zooming or zooming operation is performed; The touch point does not move, and the other touch point performs an arc motion, indicating that the rotation operation is performed, etc., and the functions that the single touch system cannot perform are completed, and all of these functions can be flexibly defined by the corresponding application software. Technical solution II

An infrared touch screen comprising an infrared emitting element disposed on an infrared emission scanning circuit board and an infrared receiving element disposed on the infrared receiving scanning circuit board, wherein the infrared emitting element on the infrared emitting scanning circuit is in at least one detecting direction The emitted light can be received by the infrared receiving element on the infrared receiving scanning circuit at a position perpendicular to its vertical position, and can be received by at least one infrared receiving element on the scanning circuit which is obliquely opposed to the vertically opposite position, that is, obliquely opposite. Received at different times.

The infrared elements are vertically opposite and obliquely opposed, but merely indicate the corresponding relationship of the infrared elements in the actual mounting position, and do not require precise adjustment of the position of the infrared elements such that their optical axes maintain the above corresponding relationship. Due to the mounting position, at the corners of the transmitting scanning circuit, some of the infrared emitting elements have no infrared receiving elements inclined to oppose them, and the light emitted by the infrared emitting elements can only be received by a vertically opposite receiving element; likewise, receiving At the corners of the scanning circuit, a part of the infrared receiving elements are not inclined with respect to the infrared emitting elements, and the infrared receiving elements only receive light from a vertically opposite transmitting element.

There are two ways for the corresponding relationship between the infrared emitting element and the infrared receiving element. One is that the infrared receiving element that is vertically opposite to the part of the infrared emitting element and the oppositely facing infrared receiving element are on the same infrared receiving scanning circuit board. The remaining infrared emitting elements are vertically opposite the infrared receiving elements and the obliquely opposite infrared receiving elements are on different infrared receiving scanning circuit boards; the other way is that the infrared receiving elements and the tilting are directly opposite to the same infrared emitting element. The infrared receiving components are respectively located on different infrared receiving scanning circuit boards.

When a portion of the infrared emitting element vertically facing the infrared receiving element and the tilting opposite infrared receiving element are on the same infrared receiving scanning circuit board, the infrared emitting scanning circuit board operates at the same timing, and one detecting scanning period is at least two. stage. In the first half or the second half of the scanning period, the light emitted by one of the infrared emitting elements is received and detected by an infrared receiving element that is perpendicularly opposite thereto, and the infrared emitting elements are turned on one by one, and the infrared receiving elements that are perpendicular to each other are aligned one by one. Receive detection. This process is similar to the ordinary infrared touch screen detection method, which is called vertical scan detection; the scanning continues to another half cycle, when the infrared emitting element is lit again, the light emitted by the infrared emitting element is received by another infrared light obliquely opposite thereto. The component receives the detection, and the infrared emitting elements are turned on one by one, and the infrared receiving elements that are opposite to each other are received and detected one by one. To distinguish it from vertical scan detection, this process is referred to herein as tilt scan detection. Thus, in one scan period, the light from one of the infrared emitting elements can be received by the infrared receiving elements at two different locations at different times.

To achieve the above solution, the infrared receiving scanning circuit board can also be operated with the same timing, and one detection scanning period is also divided into at least two stages. In the first half or the second half of the scanning period, an infrared receiving component receives the light emitted from an infrared emitting element that is vertically aligned, and the infrared receiving elements are turned on one by one, and the infrared emitting elements vertically opposite thereto are point by point. bright. This is called vertical scan detection; continue scanning to another half cycle, when the infrared receiving element is turned on again, the light it receives is detected from another infrared emitting element that is obliquely opposite thereto, and the infrared receiving element is turned on one by one. The infrared emitting elements that are inclined with respect to them are illuminated one by one. This process is called tilt scan detection. Thus, in one scan period, an infrared receiving element can receive light from two different positions of the infrared emitting elements at different times.

In the above method, the infrared ray receiving element and the slanting opposite infrared absorbing element of the part of the infrared ray emitting element are on the same infrared receiving scanning circuit board, and the remaining infrared emitting elements are vertically opposite to the infrared receiving element and the tilting is opposite. The infrared receiving components are on different infrared receiving scanning circuit boards, and the infrared transmitting circuit board or the infrared receiving circuit board can be operated with the same timing. In fact, the infrared receiving element and the obliquely opposite infrared receiving element that are vertically opposite to the same infrared emitting element can be respectively located on different infrared receiving scanning circuit boards. In this case, in order to reduce the mutual interference between the boards, each infrared emission The board or receiver board may have different timings. The infrared emission scanning circuit board uses the same timing as the example for the vertical scanning and the oblique scanning. One detection scanning period is divided into at least two stages. To reduce interference, each infrared emission scanning circuit board, especially the adjacent infrared emission scanning circuit The board adopts different timings. In the vertical scanning stage, each infrared receiving scanning circuit board uses the same timing operation as the vertical facing infrared emission scanning circuit board to realize vertical scanning detection; in the oblique scanning stage, each infrared transmitting circuit board adopts and vertically The same timing operation in the scanning phase, and the timing of each receiving circuit board is changed to become opposite to its adjacent tilt The timing of the infrared emission board enables tilt scan detection. This timing change is easier to implement under the CPU control of the touch system. For boards or infrared components that are partially mounted on corners, since there are no tilted opposing boards or infrared components, the scan program can be pre-defined for no processing during tilt scan detection.

Similarly, the touch screen of the present invention can be implemented for the infrared receiving circuit board using the same timing for vertical scanning and tilt scanning, and the timing of the infrared transmitting circuit board is changed at different scanning stages. Similar to the previous article, a detection scan period is divided into at least two stages. The infrared reception scanning circuit board uses the same timing in both vertical scanning and oblique scanning, and each infrared receiving scanning circuit board, especially the adjacent infrared receiving scanning circuit board, is different. Timing, in the vertical scanning phase, each infrared emission scanning circuit board uses the same timing operation as the vertical positive infrared receiving scanning circuit board to realize vertical scanning detection; in the oblique scanning phase, each infrared receiving circuit board adopts the same vertical scanning stage The timing operation, and the timing of each of the transmitting circuits is changed to become the timing of the infrared receiving circuit board opposite to its adjacent tilt, thereby implementing tilt scanning detection. This timing change is easier to implement under the CPU control of the touch system. For boards or infrared components that are partially mounted on corners, since there are no tilted opposing boards or infrared components, the scan program can be pre-defined for no processing during tilt scan detection.

By adopting the same infrared emitting element corresponding to different infrared receiving elements at different times, the subsequent multi-point positioning method can be realized without increasing the circuit cost.

The infrared emitting elements on the infrared emission scanning circuit and the infrared receiving elements on the infrared receiving scanning circuit in the same detection direction are all deflected by the same angle in the same direction such that the infrared emitting elements are opposed to the infrared receiving elements. Due to the mounting position, at the corners of the transmitting scanning circuit, a part of the infrared emitting elements have no infrared receiving elements obliquely opposite to them; likewise, at the corners of the receiving scanning circuit, a part of the infrared receiving elements have no infrared emitting elements and are inclined with respect to them. These infrared emitting/receiving elements may not deflect the angle. The deflection angle can be calculated and determined according to the selected parameters of the infrared emitting element and the infrared receiving element, combined with the size of the touch detection area; or can be determined by experimental tests according to actual effects. Under the premise of satisfying the receiving energy of the infrared receiving component, the deflection angle of the infrared component should be as large as possible, so that the position of each touch point can be better distinguished, and the calculation precision of the coordinates of multiple touch points can be improved. The effect of the present invention can also be achieved by selecting a component having a larger emission angle than that of a conventional red component. This component can be used without deflecting the infrared emitting component and the infrared receiving component by a certain angle.

The infrared receiving element and the obliquely opposite infrared receiving elements vertically opposite to the same infrared emitting element are respectively located on different infrared receiving scanning circuit boards, and may also be on the same infrared receiving scanning circuit board. It depends on the magnitude of the deflection angle of the infrared emitting element and the infrared receiving element.

In the infrared radiation receiving and receiving array of the infrared touch screen, the infrared emitting elements and the infrared receiving elements in the horizontal array are different in frequency from the infrared emitting elements and the infrared receiving elements in the longitudinal array to avoid interference between the infrared emitting infrared receiving elements. For example, using a 940 nm infrared emission receiving element in a lateral array and a vertical array 850nm infrared emission receiving component, so that in the detection area of the corner, adjacent infrared transmitting and receiving components do not interfere with each other. For the specific method, refer to application number 200610037391. X adjacent infrared scanning unit has different frequency infrared Tube infrared touch device.

Corresponding to the above circuit structure change, the multi-touch positioning method of the present invention mainly comprises the following steps: a) starting the scan generator, first normalizing and/or initializing the infrared receiving component vertically opposite the infrared emitting component, and then returning Integrating and/or initializing the tilted opposite infrared receiving elements, respectively recording the tilt normalized value and/or the tilt initializing value of each of the infrared receiving elements; or first normalizing and/or initializing the tilted opposing infrared receiving elements Initializing and/or initializing vertically facing elements, respectively recording skew normalized values and/or initialization values and vertical normalization values and/or initialization values;

b), sequentially turning on and illuminating each of the infrared emitting elements, simultaneously turning on the infrared receiving element at a position directly opposite to the infrared emitting element, reading the output value of the infrared emitting element and vertically normalizing the value and/or initializing value thereof Comparison

c) calculating the possible position coordinates of each touch point according to the change obtained by comparing the output values of the infrared receiving elements with the normalized value and/or the initial value;

d), continue scanning, sequentially turn on and illuminate each of the infrared emitting elements, simultaneously turn on the infrared receiving element at a position opposite to the infrared emitting element, and read the output value of the receiving element opposite to the tilt of the infrared emitting element and normalize with the tilt Comparison of the value and / or initialization value;

e), according to the change of the output value of each infrared receiving component and the tilt normalized value and/or the initial value, obtain each position parameter, determine the relationship between the actual coordinates X and Y of the touch point, and step c The calculated possible touch point values are substituted into the formula determined by each position parameter to determine the position coordinates of each touch point, and the coordinate data is sent to the computer for processing;

f), according to the method from step b to step e, start a new cycle.

Another main method for realizing the multi-touch positioning method of the present invention is that the oblique scanning is performed first, and then the vertical scanning is performed, and the others are the same as described above.

In the above step e, the specific form of the verification formula used to determine the actual position of the touch event has various forms, one of which may be of the following form - Y = (X - 1) ctg 9 ,

Y= (L-X) tg a + h , the equation holds the actual coordinate value;

The origin of the coordinate axis is at the upper right (the selection of the actual origin can be freely selected, and can be selected at the lower left, upper left or any other position, and then the simple change of the proof formula can be performed), and the X-axis direction scan is from right to left. , Y-axis direction scan from top to bottom, X, Y represents the touch point coordinate value to be determined, L represents the total length of the touch area in the X-axis direction, 1 is the X-direction infrared receiving element output value changes and the reception The distance from the infrared ray element of the component opposite to the origin is the positional parameter in the X-axis direction, and h is the time when the output value of the infrared receiving component in the Y direction changes. The distance from the infrared ray element of the slanting element to the origin is the positional parameter in the Y-axis direction, Θ indicates the infrared ray element in the X-axis direction and the illuminating infrared receiving element line and the infrared ray element and the vertical directional infrared receiving The angle between the component wires, α represents the angle between the infrared emitting element in the Y-axis direction and the line connecting the obliquely opposite infrared receiving element and the line connecting the infrared emitting element and the vertical facing infrared receiving element. When the position of the coordinate origin is different, the expression of the formula will change, but no matter how the form of the formula changes, the meaning of the formula is still the relationship between the horizontal and vertical coordinates of the touch point.

The above-mentioned radiating elements or receiving elements mounted at the corners, since no infrared elements are obliquely opposed to them, these infrared emitting elements or infrared receiving elements can be pre-defined and not processed by the scanning program when performing tilt scan detection.

Using the structure and method of the present invention, in some cases, multi-touch positioning can be achieved with only one direction of detection. When it is difficult to calculate the position coordinates of the touch point using one direction touch detection, the two directions can be used to comprehensively judge the data. For example, when the touch point is close to the corner area or when a plurality of touch points are close to overlap in a small area, it is necessary to perform comprehensive judgment in combination with the detection data of the two directions.

The multi-touch positioning method of the present invention divides the scanning detection into two processes of vertical scanning detection and oblique scanning detection. In fact, the oblique scanning does not have to be performed all the time. When the position coordinates of the respective touch points have been determined and remain stable, Only vertical scanning detection is performed, so that multiple touch points can be identified by judging the movement tendency of each touch point. For the method of identifying multiple touch points by detecting the movement trend of the touch point, reference may be made to the application number CN 200710028038. Chinese patent for touch positioning method. At this time, the step of oblique scanning can be omitted, and the refresh rate of the touch detection can be maintained at a high level by such a method.

In the technical solution of the present invention, only two stages are divided in the stage of the scanning cycle. In fact, if necessary, one scanning period can be divided into three or more stages, and several scanning detections are performed, so that One transmitting element can correspond to three or more receiving elements, and accordingly, the detection system can obtain more positional parameters, and more proofing formulas are used to determine the actual position coordinates of the plurality of touched points.

Through the above-mentioned circuit structure change and using the corresponding multi-point positioning algorithm, the infrared touch screen system can distinguish multiple touch points that are simultaneously touched, so that multi-touch positioning can be realized on the infrared touch screen. On the basis of this, further, according to the change of the position coordinates, the moving tendency of each touch point can be determined, according to which different touch operation functions can be defined, for example, the opposite directions of the two touch points indicate that the zooming or zooming operation is performed; The touch point does not move, and the other touch point performs an arc motion, indicating that the rotation operation is performed, etc., and the functions that the single touch system cannot perform are completed, and all of these functions can be flexibly defined by the corresponding application software. Technical solution three

An infrared touch screen in which at least one of the infrared emitting elements and the infrared receiving elements are in contact The direction of the center of the touch screen is deflected such that the infrared emitting elements on the infrared emitting scanning circuit face the infrared receiving elements on the infrared receiving scanning circuit, forming an intersecting correspondence relationship. Specifically, one infrared emitting element A vertically corresponds to one infrared receiving element A', and the tilt corresponds to one receiving element Β '; and the infrared emitting element corresponding to the receiving element B' vertically corresponds to the corresponding B', and correspondingly The receiving element Α ', such that the transmitting elements Α, Β, and the receiving elements A ', B ' form an intersecting correspondence.

The vertical correspondence of the infrared elements described above corresponds to the tilt, and only indicates the corresponding relationship of the infrared elements in the actual mounting position. It is not required to precisely adjust the position of the infrared elements so that their optical axes maintain the above corresponding relationship. The deflection angle can be calculated and determined according to the selected parameters of the infrared emitting element and the infrared receiving element, combined with the size of the touch detection area; or can be determined by experimental tests according to actual effects. Under the premise of satisfying the receiving energy of the infrared receiving component, the deflection angle of the infrared component should be as large as possible, so that the position of each touch point can be better distinguished, and the calculation precision of the coordinates of the plurality of touch points can be improved.

The infrared touch screen adopting the above correspondence relationship may be arranged on the receiving circuit board or on the transmitting circuit board. Accordingly, there may be one or two transmitting circuit boards in a certain direction. The microprocessor and the prior art main microprocessor are arranged on the receiving circuit board, and the main microprocessor is more flexible to meet the needs of different structural forms of the touch screen. After the main microprocessor is arranged on the transmitting circuit board, the receiving board can have only one microprocessor.

With the technical solution of the present invention, the infrared emitting element and the infrared receiving element form a cross-corresponding relationship, and relative to the corresponding mode of the second technical solution, all the infrared emitting elements can be turned on and off twice, and all the receiving elements are also Corresponding reception twice, achieving a true tilt scan coverage of 100%, there will be no case where the infrared elements in the corners of the second scheme cannot be covered during the oblique scanning process and special processing must be performed.

With the technical solution of the present invention, the scanning detection method and the process and the multi-point positioning method are similar to the technical solution 2, and will not be repeatedly described herein.

Using the structure and method of the present invention, in some cases, multi-touch positioning can be achieved with only one direction of detection. When it is difficult to calculate the position coordinates of the touch point using one direction touch detection, the two directions can be used to comprehensively judge the data.

The multi-touch positioning method of the present invention divides the scanning detection into two processes of vertical scanning detection and oblique scanning detection. In fact, the oblique scanning does not have to be performed all the time. When the position coordinates of the respective touch points have been determined and remain stable, Only the vertical scan detection is performed, so that a plurality of touch points can be identified by judging the movement tendency of each touch point. A method for identifying a plurality of touch points by detecting a trend of a touch point motion: comparing a change in the number of position coordinates detected in the current period with the previous calculation period and/or a change in the coordinate value, and registering a new touch point when a new touch point is added Information, if there is a touch point to leave, cancel the left touch point information; compare the change of the coordinate value (x, y) detected in this cycle with the previous calculation cycle, and the coordinate value (x, y) and the registered Compare the current position coordinates of the touch point, Judging the movement trend of the touch point; calculating and judging the touch point where the position changes, and assigning the latest coordinate value to the touch point. At this time, the step of oblique scanning can be omitted, and the refresh rate of the touch detection can be maintained at a high level by such a method.

Compared with the existing touch technology, the present invention has the following beneficial effects:

— Multi-touch positioning can be achieved without increasing hardware costs.

Second, the application is more extensive. It can realize single touch and multi-touch, and complete the existing touch screen; the multi-person simultaneous operation function that is difficult to implement can be applied to more fields and occasions.

Third, the algorithm for realizing multi-point positioning is simple, and the coordinates of the touch point position are convenient, accurate and reliable.

Fourth, the circuit board type is small, the shape is regular, and it is easy to realize mass production.

[Description of the Drawings]

1 is a schematic structural diagram of a circuit according to an embodiment of the first technical solution of the present invention;

2 is a circuit timing diagram of an embodiment of the first technical solution of the present invention;

3 is another circuit timing diagram of an embodiment of the first technical solution of the present invention;

4 is a schematic diagram of two point touch positioning according to an embodiment of the first technical solution of the present invention;

FIG. 5 is a schematic diagram of a touch point pre-detection calculation according to an embodiment of the first technical solution of the present invention; FIG.

6 is a schematic diagram of non-positive correspondence calculation of an infrared component according to an embodiment of the first technical solution of the present invention;

7 is a schematic diagram of detecting touch points in two directions according to an embodiment of the first technical solution of the present invention;

8 is a schematic flow chart of a multi-touch positioning method according to an embodiment of the first technical solution of the present invention;

9 is a schematic structural diagram of another circuit of an embodiment of the first technical solution of the present invention;

FIG. 10 is a schematic structural diagram of another circuit according to an embodiment of the first technical solution of the present invention; FIG.

11 is a schematic structural diagram of a circuit of an embodiment of the second technical solution of the present invention;

12 is a schematic diagram of a circuit scanning operation of an embodiment of the second technical solution of the present invention;

13 is a schematic diagram of two point touch positioning according to an embodiment of the second technical solution of the present invention;

14 is a schematic flow chart of a multi-touch positioning method according to an embodiment of the second technical solution of the present invention;

Figure 15 is a schematic view showing an embodiment of an infrared touch panel according to a third aspect of the present invention.

【detailed description】

Specific implementation of technical solution one

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram showing the structure of a circuit according to an embodiment of the present invention. 101, 103 are infrared emitting elements mounted at different positions on the transmitting circuit board 111, 102, 104 are infrared emitting elements mounted on the transmitting circuit board 112, wherein the mounting position of 101 on 111 and 102 are at 112 The mounting position is the same, the mounting position of 103 on 111 is the same as the mounting position of 104 on 112. 115, 116, 117, 118 are receiving boards. As can be seen from the figure, The receiving boards 115 and 116 correspond to the transmitting board 111 in correspondence with the mounting positions, and 117 and 118 correspond to 112. Specifically, it can be seen that the infrared emitting element 101 corresponds to the infrared receiving element 105 facing the infrared receiving element 105, and also corresponds to the infrared receiving element 106, 101 and 106. The angle is at an angle with the central axis of the component. This correspondence can be achieved by selecting a component whose emission angle is larger than that of the ordinary infrared component, or by a method of deflecting the component by a certain angle during the installation process. The size of the angle can be determined according to actual needs. Similarly, the infrared emitting element 102 corresponds to the infrared receiving elements 107 and 108 at the same time, 103 corresponds to 106 and 107 at the same time, and the corresponding direction of the emission in the other direction is the same as that of the infrared receiving element, and is not repeated here.

After the above structural change, the correspondence between the transmitting boards 111, 112 and the receiving boards 115, 116, 117, 118 has been different from the one-to-one correspondence of the conventional infrared touch screen circuits. In order to coordinate the normal operation of the components, the circuit with the infrared emitting elements is equipped. The board and the board with the IR receiving components must operate at their respective timings. 2 is a timing diagram of the present example. The infrared emitting elements on the transmitting circuit boards 111 and 112 operate according to the timings shown in 201 and 202, respectively, and the corresponding receiving circuit boards 116, 118 operate according to the timings shown in 206 and 208, respectively. According to the corresponding relationship shown in FIG. 1, the receiving board 116 only corresponds to the transmitting board 111, and the receiving board 118 only corresponds to the transmitting board 112. Therefore, the timings of 201 and 206 in FIG. 2 are the same, and the timings of 202 and 208 are also the same. For the receiving boards 115 and 117, there are more than one corresponding transmitting board. Therefore, the timing of the operation changes with the corresponding situation of the transmitting board, as shown in Figs. 205 and 207.

FIG. 3 is another timing diagram of the present example. When the detection system starts scanning from the infrared emitting element 101, 101 operates according to the timing shown by 301, and at the same time, the infrared receiving elements 105, 106 corresponding to 101 are also in accordance with 301. The timing of the work. At this time, the infrared emitting element 102 and the infrared receiving elements 107, 108 operate in accordance with the timing shown at 302. When the detection system continues to scan to the infrared emitting elements 103 and 104, the timing of certain boards needs to be properly adjusted, as shown at 303, the operating timing of the infrared emitting elements 103 and corresponding infrared receiving elements 106, 107 has changed. . 304 denotes the timing of the infrared emitting element 104 and the corresponding infrared receiving element 108.

The correspondence between the timings of the infrared emitting element and the infrared receiving element shown in FIG. 2 and FIG. 3 is only two of a plurality of corresponding relationships, and the actual correspondence relationship is not limited to the two listed, but may be based on Need to adjust.

With the above circuit structure, for a multi-touch event occurring at the same time, the touch screen system can determine whether there is another touch point in a certain area nearby and mark it well in determining the occurrence of a touch event, and combine the further detection data. The position coordinates of a plurality of touch points can be calculated. A method of implementing multi-touch positioning for how to recognize multiple touch points will be described in conjunction with FIG. In order to reduce the length, only the detection process in one direction is described below. In fact, the detection process in the other direction is completely similar.

As shown in FIG. 4, touch points 410 and 411 operate simultaneously on the touch screen, 401 represents a transmitting board, and 404 represents a receiving board. Before the touch detection is started, the scan generator starts to work, and the normalization of each infrared receiving element is completed. after that Starting to turn on each of the infrared emitting elements and the corresponding infrared receiving elements, when the infrared emitting element 402 is turned on, the output value of the infrared receiving element 405 facing it does not change, and the detecting system considers that no touch event occurs at the place; However, there is a change in the output of the infrared receiving element 407 corresponding to a certain angle of 402. The system determines that a touch event occurs in the angled region, and activates the touch point pre-detection algorithm to mark the area for further judgment. When the infrared emitting element 403 is further scanned, the output of the infrared receiving element 406 corresponding thereto changes, thereby determining that a touch event occurs at the place, and in combination with the judgment of the previous pre-detection algorithm, the location is within the marked area. It is determined that there is a touch point 411 at this point, and the position coordinates of the touch point can be calculated. Continuing to scan the infrared emitting element and the corresponding infrared receiving element, the coordinate position of the touch point 410 can be determined.

With reference to FIG. 8, the process of the multi-touch implementation method of the embodiment of the present invention can be obtained. For the specific steps, refer to the corresponding part of the invention in the first technical solution.

FIG. 5 is a schematic diagram of a touch point pre-detection calculation according to an embodiment of the present invention. As shown in the figure, when the infrared emitting element 501 is scanned, the output value of the infrared receiving element 505 corresponding to a certain angle of 501 is detected to change, and the touch point pre-detection algorithm determines that the angle has a touch event, using the formula.

Y= X · ctg 6 , ( 1 )

That is, the possible location of the touch event can be calculated. Wherein X represents the distance between the infrared receiving element 503 facing the transmitting tube and the infrared receiving element 505 corresponding to the infrared emitting element, and Θ represents the angle between the infrared emitting element and the non-pairing infrared receiving element. 508. According to further scanning detection, the true position of the touch event in the marked area is obtained between the infrared emitting element 502 and the infrared receiving element 504, and the coordinate values of the possible touch points 506 are calculated using the above formula. The position coordinates of the touch point 507 can be obtained using the same method.

In this embodiment, the corresponding relationship between the infrared emitting element and an infrared receiving element is a positive correspondence relationship, and the other infrared receiving element has a non-positive correspondence relationship, and the previous calculation formula can be used. In fact, the relationship between the infrared emitting element and the infrared receiving element can be completely non-positive, as shown in Fig. 6. At this time, the above formula needs to be appropriately modified. In Fig. 6, 601, 601 are infrared emitting elements, 603, 604 are infrared receiving elements corresponding to 601, 605, 606 are receiving elements corresponding to 602, and 607 is a touch point. 608 denotes the angle between 601 and 604, denoted by α, 609 denotes the angle between the line 601 and 603 and the line connecting 601 and 604, denoted by β, in this case, the possible position of the touch point 607 It can be expressed by the following formula:

Υ = X [sin a . _s in ( α + β ) ] /sin 3 , (2)

X represents the distance between 603 and 604. Although formula (1) and formula (2) are different in form, they are essentially the same. Equation (1) can be regarded as a simpler example of formula (2). 2) When α + β = 90°, the formula ( 1 ) is exactly the same as the formula (2 ).

After the above calculation, the position of each touch point can be correctly found. After identifying the position coordinates of each touch point, various operation functions can be defined according to the movement trend of each point, and the user operation intention is recognized. For example, at a certain In the occasion, the two touch points move in the opposite direction, indicating that the zoom operation is performed; one touch point does not move, and the other touch point performs an arc motion, indicating that the rotation operation is performed, and the like. These operational functions can be flexibly defined by the corresponding application software.

In the present embodiment, to simplify the description, only one direction of detection is judged. In fact, the detection and judgment process of the other direction is exactly the same as described above. When it is difficult to calculate the position coordinates of the touch point using one direction touch detection, Use two directions to detect data to make a comprehensive judgment. As shown in FIG. 7, when the two touch points 701, 702 are relatively close and on the same horizontal line, the pre-detection algorithm will mark the regions where the two touch events occur, as can be seen from the figure, the two regions are generated. More overlap, if only one direction of touch detection data is used, the possible position of the touch point calculated by the pre-detection algorithm is 701, 702, 703, 704, and the actual position of the touch cannot be accurately determined, and there is a possibility of misjudgment. In this case, it is necessary to use the detection data of another detection direction for comparison to accurately determine the actual position of the touch points 701, 702. In addition, when the touch point is operated in a small area of the corner of the touch screen, since the pre-detection algorithm cannot be enabled, it is also necessary to use two direction detection data to calculate the position coordinates of the touch point.

FIG. 9 is a schematic diagram of another circuit structure of an embodiment of the present invention. In the figure, 921, 922 are respectively a transmitting circuit board mounted with an infrared emitting element and a receiving circuit board equipped with an infrared receiving element, and 911, 912 are 8, 16, or other numbers of infrared emitting elements on the transmitting circuit board 921. The two emission scanning units, 913, 914, 915, 916, are received scanning units on the receiving circuit board 922, and 901, 902, 903, 904, 905, 906 are infrared elements on the respective scanning units. It can be seen from the corresponding relationship in the figure that the correspondence between the infrared transmitting element and the infrared receiving element is the same as the previous description of the two receiving scanning units corresponding to the transmitting scanning unit, and the timing chart of each scanning unit works with FIG. 2 and the drawing. 3 Similar, only a small amount of changes are made according to the actual situation, and will not be discussed here.

FIG. 10 is a schematic diagram of still another circuit structure of an embodiment of the present invention. As shown by the solid line separation in the figure, 1021, 1022 respectively represent an infrared transmitting circuit board and an infrared receiving circuit board, and 1011, 1012, 1013, 1014 represent logically divided scanning units including a certain number of infrared elements on each circuit board, and 1001 represents Infrared emitting elements, 1002, 1003, represent infrared receiving elements. The 1011 emission scanning unit starts from 1001 and turns on and illuminates the respective transmitting elements one by one. Correspondingly, the 1013 receiving scanning unit starts to receive the respective receiving elements one by one from the beginning of 1002, and at the same time, corresponding to 1011, the receiving scanning unit starts from 1003 one by one. Each receiving element is turned on for reception. The timing chart of the operation of each scanning unit is similar to that of FIG. 2 and FIG. 3, and only a small number of changes are needed according to the actual situation, and will not be discussed here. Specific implementation of technical solution 2

Figure 11 is a block diagram showing the structure of a circuit according to an embodiment of the present invention. In the figure, 1121, 1122, 1123, 1124 are transmitting circuit boards on which infrared emitting elements are mounted, and 1101, 1102, 1103, 1104, 1105, 1106, 1107 are infrared emitting elements mounted on the above circuit board. 1108, 1109, 1110, 1111, 1112, 1113, 1114 are infrared receiving elements mounted on receiving circuit boards 1125, 1126, 1127, 1128. It can be seen from the figure that the correspondence between the infrared emitting element and the infrared receiving element is different from that of the ordinary infrared touch screen, and the infrared emitting element 1101 is in addition to In addition to the infrared receiving element 1108 which is perpendicular to the vertical direction, it also corresponds to the infrared receiving element 1109. Since the position of 1109 deviates from 1108 by a certain distance, in order to simplify the description, the correspondence between 1101 and 1109 is referred to as tilting, and the same 1102 is opposite to 1110 except that it is vertically opposite to 1109; 1103 is perpendicular to 1110, opposite to 1111, 1104 and 1111 are perpendicular to each other, opposite to 1112, 1105 and 1112 are perpendicular to each other, and 1113 Tilting opposite, 1106 and 1113 are vertically opposite, opposite to 1114. Due to the corners, 1107 and the infrared emitting elements behind it are only perpendicular to one receiving element, and no receiving elements are obliquely opposed to them. Similarly, some of the infrared receiving elements prior to 1109 include 1108, and no infrared emitting elements are obliquely opposed to them. The transmission in the other direction is the same as the correspondence between the infrared receiving elements and will not be repeated here.

This correspondence can be achieved by a method of deflecting the component by a certain angle during the installation process, for infrared components mounted on the corners such as the 1107 and the infrared emitting components behind it and some of the infrared receiving components before 1109 because there is no infrared The elements are inclined relative to them and can be angled without deflection. The magnitude of the deflection angle of the infrared component can be calculated and determined according to the parameters of the selected infrared emitting component and the infrared receiving component combined with the size of the touch detection area; it can also be determined experimentally according to the actual effect. For example, the emission angle of an infrared emitting element is nominally 35 degrees. In fact, its emission energy is concentrated in the range of 0-18 degrees. If it is used on a 100" touch screen, due to the working distance between the transmitting element and the receiving element. Farther, in order to ensure better results, the deflection angle of the transmitting element and the receiving element can be selected to be about 8 degrees. Of course, the actual deflection effect can also be selected by the actual effect of the experimental test. In addition to deflecting the transmitting element and the receiving element to a certain extent In addition to the above relationship, the angle can be achieved without using a deflection angle, by selecting an element having a larger emission angle than that of an ordinary infrared element, since the infrared element used in the infrared touch screen usually has a small emission angle, thus making the infrared energy It is better to focus on the opposite receiving components, and to achieve the above-mentioned correspondence, it is necessary to use an infrared component with a large emission angle. For the specific method, refer to the Chinese patent No. 200710028616.

In order to facilitate the description of the scanning detection method of the embodiment of the present invention, the scanning detection method of the ordinary infrared screen is referred to as vertical scanning detection. Unlike the ordinary infrared touch screen scanning detection process, the above circuit configuration is adopted, and each scanning detection period is used. Within, the scan detection process is divided into two phases. Taking FIG. 11 as an example, in the first half of the scanning period, the transmitting board starts to light up from 1101, at this time, 1108 is turned on, the value is output, and then the infrared element after 1101 is turned on, and the receiving element facing it is turned on at the same time. ..., each of the infrared emitting elements 110 1103, 1104, 1105, 1106, 1107, etc. is sequentially illuminated, and the receiving elements 1109, 1110, 1111, 1112, 1113, 1114 are sequentially turned on to output values. At this point, the scan is performed for half a cycle, and the vertical scan detection is completed. In the next half cycle, the infrared emitting elements illuminate in the same manner as the first half of the cycle, and the order in which the receiving elements are turned on is in a different order. When 1101 is lit, 1109 is turned on, the output value is, and the infrared after 1101 When the component is lit, the infrared receiving component after 1109 turns on, the output value, ..., 1102 lights up, 1110 turns on, the output value, 1103 lights up, 1111 turns on the output value, 1104 lights up, 1112 turns on the output value , 1105 lights up, 1113 turns on the output value, 1106 lights up, 1114 Turning on the output value, sequentially lighting each of the transmitting elements and simultaneously turning on the receiving elements opposite to their respective tilts, this process is different from vertical scanning detection, which is referred to herein as tilt scan detection, at which point a complete scan cycle is completed. As for the infrared light-emitting elements of 1107 and its rear, and some of the infrared-receiving elements before 1109, there are no infrared elements that are inclined with respect to them due to the corners. This part of the infrared elements can be pre-defined by the scanning program during tilt scan detection. Do the processing.

Figure 12 shows the process of circuit scanning. As shown in Figure 2, the scan detection is divided into two stages, a vertical scan phase and a tilt scan phase, assuming that there are n infrared emitting elements or infrared receiving elements on each circuit board, assuming a tilted opposite reception of the first transmitting element. The element is the mth receiving element, and the receiving element obliquely opposite to the second emitting element is the m+1th receiving element, ..., arranged in this way, the receiving element obliquely opposite to the η-m+l emitting element Is the nth receiving component. When performing vertical scanning, both the transmitting component and the receiving component are turned on one by one from the first to the nth; when performing the oblique scanning, the transmitting component starts from the first, and the transmitting component is from the first to the n-m. +1 turn-on and turn-on, and the receiving elements that are opposite to each other are turned on one by one from the mth to the πth, and continue scanning, and the n-th+2th to nthth emitting elements are turned on one by one. When the receiving element is turned on, the sequence is turned back to the front, and the detection is performed one by one from m1 to m-1. At this time, the first to m-1th receiving elements receive the output from another transmitting circuit board. The light emitted by the infrared emitting elements opposite to them. Similarly, the light emitted from the n-m+2th to the nth infrared emitting elements is received by the infrared receiving elements on the other receiving circuit board which are inclined with respect to them.

In the scanning method shown in FIG. 12, the infrared transmitting circuit board or the infrared receiving circuit board operates at the same timing. In fact, in order to reduce mutual interference between the boards, each of the infrared emitting circuit boards or the receiving circuit board may Use different timings. For example, adjacent infrared emission scanning circuit boards use different timings. In the vertical scanning stage, each receiving circuit board uses the same timing operation as the vertical positive infrared emission scanning circuit board to realize vertical scanning detection; in the oblique scanning stage, each The infrared transmitting circuit board operates at the same timing as the vertical scanning phase, and the timing of each receiving circuit board is changed to become the timing of the infrared transmitting circuit board which is inclined with respect to it, thereby implementing tilt scanning detection. This timing change is easier to implement under the CPU control of the touch system. For boards or infrared components that are partially mounted on the corners, since there are no oppositely facing components, the scanning program can be pre-defined for no processing during tilt scan detection.

With the circuit structure of the embodiment, for a multi-touch event occurring at the same time, the touch screen system can determine the possible position coordinates of the touch point by performing a vertical scan detection first, and then determine the coordinate relationship of each touch point position by one tilt scan detection. Then, the possible position coordinate values of the touch points obtained by the vertical scan detection are substituted into the coordinate relationship formula determined by the tilt scan detection, and the position coordinates of the respective touch points are determined. A method of realizing multi-touch positioning will be described below with reference to FIG.

As shown in FIG. 13, it is assumed that the total length of the touch area in the X-axis direction is L, and the transmitting element and the receiving element are in the X-axis direction. The deflection angles of the pieces are opposite, and the angles of the deflection elements of the x-axis direction and the direction of the deflection of the receiving elements are opposite. The scanning in the X-axis direction is performed from the right to the left, and the scanning in the γ-axis direction is performed from the top to the bottom. The coordinate origins required for the calculation are selected in the upper right X-direction scanning and the x-direction scanning start. The touch points 1301 and 1302 are simultaneously operated on the touch screen, and their coordinates on the touch screen at a certain time are (Xa, Ya), (Xb, Yb), respectively. The touch device shown in FIG. 13 needs to complete the normalization or initialization of each infrared receiving component before starting the touch detection. In this embodiment, since the circuit structure is different from the conventional touch screen, the normalization or initialization steps are divided into two. Step, first normalize or initialize the vertically facing infrared receiving component, and then normalize or initialize the receiving component opposite to the tilting of the transmitting component according to the corresponding relationship of the oblique scanning, and save the two normalized values or initial values respectively. For vertical normalization or initialization values, tilt the normalized value or initialized value. After the normalization or initialization process is completed, according to the scanning detection method described above, each of the infrared emitting elements and the infrared receiving elements perpendicular thereto are sequentially turned on, and the output values and vertical normalization values of the respective infrared elements are detected. Whether the initialization value is changed or not. In the X-axis direction, when the infrared emitting elements 1304, 1306 are turned on, the output values of the infrared receiving elements 1307, 1309 which are perpendicular to them are changed, and the detecting system considers that two touch events occur, and records their X-axis coordinates. The values X, X are also similar. When the infrared emitting elements 1313, 1314 in the x-axis direction are scanned, the output values of the infrared receiving elements 1315, 1316 which are perpendicular to them are changed, thereby judging that the two axes are in the direction of the x-axis Touch touch events occur, and their axis coordinate values Yi, Y ₂ are recorded. In this way, the system can obtain four sets of possible touch point coordinate values of touch points 1301, 1302, Υ, ), , Υ ₂ ) , , Υ , ) , ₂ , γ ₂ ) .

The scanning of the lower half cycle is continued, and the receiving component that is turned on is tilted relative to the receiving component of the infrared emitting component, and whether the output value of each infrared receiving component is compared with the tilt normalized value or the initial value is detected. In the X-axis direction, when the light is illuminating 1303, the output value of the receiving element 1308 opposite thereto is changed, thereby determining that a touch event occurs on the line connecting 1303 and 1308, and recording the distance 113 from the origin of the coordinate The same method can be used to determine that another touch event occurs on the line between 1305 and 1310, and note the distance 12 from the origin of the 1305 to the coordinate origin. In the y-axis direction, when the lights 1311, 1312 are lit, the output values of the receiving elements 1317, 1318 which are inclined with respect to them are changed, and it can be judged that the lines of 1311 and 1317 and the lines of 1312 and 1318 are connected. When a touch event occurs, the distances hl, h2 of the origins of the coordinates of 1311 and 1312 from the origin of the coordinates are recorded separately. As can be seen from the relationship in the figure, the coordinate relationship of the touch points 1301, 202 needs to satisfy the following relationship - Ya = (Xa-11) . ctg θ ,

Yb= (Xb-12) . ctg 0,

Ya= (L-Xa) . tg a +hl ,

Yb= (L-Xb) . tg a +h2,

Substituting the above four possible touch point coordinates (Χ^ Υ, ), ( XY ₂ ), ( , Υ, ), ( , Υ ₂ ) into the formula check, that can accurately determine the coordinates of 1301 as ( , Υ,) The coordinates of 1302 are (Χ ₂ , Υ ₂ ). With reference to FIG. 14, the process of the multi-touch implementation method of the embodiment of the present invention can be obtained. For the specific steps, refer to the corresponding part of the invention in the second technical solution.

In this embodiment, the scanning detection is divided into two processes: vertical scanning detection and oblique scanning detection. In fact, the oblique scanning does not have to be performed all the time. When the position coordinates of the respective touch points have been determined and remain stable, only the vertical scanning detection is performed. For determining the motion trend of each touch point, a plurality of touch points can be identified. For the method for identifying a plurality of touch points by detecting the movement trend of the touch point, reference may be made to the Chinese patent of the application number CN 200710028038. X-type multi-touch positioning method. At this time, the step of tilt scanning can be omitted, which can keep the refresh rate of touch detection at a high level.

After the above calculation, the position of each touch point can be correctly found. After identifying the position coordinates of each touch point, various operation functions can be defined according to the movement trend of each point, and the user operation intention is recognized. For example, in an application, two touch points move in the opposite direction, indicating that the zoom operation is performed; one touch point does not move, and the other touch point performs an arc motion, indicating that the rotation operation is performed, and the like. These operational functions can be flexibly defined by the corresponding application software.

In this embodiment, in order to improve the anti-interference performance of the touch screen system, some measures may be taken. For example, infrared components of different frequencies are installed in the infrared emission receiving arrays of different detection directions, infrared components of 940TM are used in the horizontal detection direction, and infrared components of 850 nm are used in the vertical direction, so that in the detection area of the corners, There is no possibility that adjacent infrared elements interfere with each other. Specific implementation of technical solution three

Figure 15 is a schematic view showing a first embodiment of the present invention, showing that the infrared emitting element and the infrared receiving element form an intersection relationship in the vertical detecting direction. In the figure, 1501, 1501, 1503, 1504 are infrared emitting elements mounted on a transmitting circuit board, and 1505, 1506, 1507, and 1508 are infrared receiving elements mounted on a receiving circuit board. As can be seen from the figure, in the detection direction where 1501, 1505 is located, the infrared emitting element and the infrared receiving element are vertically opposite, and in the detecting direction where 1503, 1508 is located, the infrared emitting elements 1503, 1504 are directed to the touch screen. The center is deflected by a certain angle, and the direction of the 1503 deflection angle is opposite to that of 1504. Accordingly, the infrared receiving elements 1507, 1508 are also deflected toward the center of the screen by a certain angle. Thus, 1503 is opposite to 1507, and 1504 is perpendicular to 1507, and opposite to 1508, 1503, 1504, 1507, 1508 form the cross-corresponding relationship shown in the figure. This correspondence can be achieved by a method of deflecting the component by a certain angle during the installation process. The magnitude of the deflection angle of the infrared component can be calculated according to the selected parameters of the infrared emitting component and the infrared receiving component combined with the size of the touch detection area. Determined; can also be determined by experimental tests based on actual results. For example, the emission angle of an infrared emitting element is nominally 35 degrees, and its emission energy is actually concentrated in the range of 0-18 degrees. If used on a 40" touch screen, due to the working distance between the transmitting element and the receiving element. Farther, in order to ensure better results, the deflection angle of the transmitting component and the receiving component can be selected to be about 12 degrees. Of course, it can also be tested experimentally. The actual effect is to choose the appropriate deflection angle.

In addition, the infrared touch screen using the circuit structure shown in FIG. 15 may be arranged on the receiving circuit board or on the transmitting circuit board, and accordingly, the transmitting circuit board in a certain direction may be There are one to two microprocessors, and the main microprocessor is arranged on the receiving circuit board in comparison with the prior art main microprocessor, and the main microprocessor is more flexible to meet the needs of different structural forms of the touch screen. After the main microprocessor is arranged on the transmitting circuit board, the receiving board can have only one microprocessor.

In a second embodiment of the present invention, the infrared emitting element and the infrared receiving element form a cross-corresponding relationship in the horizontal detecting direction.

The above two specific implementation manners can meet the multi-touch requirement in many occasions, and for the more touch points and the higher multi-touch requirements, it is necessary to adopt the third embodiment of the present invention, that is, in the vertical In the two detection directions of the horizontal and horizontal directions, the infrared emitting element forms an intersecting relationship with the infrared receiving element. In this way, the tilt scan can be performed in both detection directions of the touch screen, and the cover rate of the tilt scan can reach 100%. For simultaneous multi-touch events, the touch screen system can determine the possible position coordinates of the touch point by performing a vertical scan detection first, and then determine the relationship of the touch point coordinates in both detection directions by one tilt scan detection, thereby Accurately identify each touch point.

The scanning detection process and the multipoint positioning method according to the above specific embodiments are similar to those described in the second aspect.

The preferred embodiment of the corresponding technical solution of the above-described embodiments, in fact, the circuit structure can be more flexible. In addition, the timing of the operation of the infrared emitting element and the infrared receiving element can also be adjusted according to the actual situation. If necessary, one scanning period can be divided into three or more stages, and several scanning detections are performed. Therefore, the scope of the present invention is not limited thereto, and any insubstantial changes based on the technical solutions of the present invention are included in the scope of the present invention.

Claims

Claim

1. An infrared touch screen, characterized in that: in at least one detection direction of the touch screen, a set of infrared emission scanning circuits corresponds to two sets of infrared receiving scanning circuits; and a light emitted by an infrared emitting element in a set of infrared emitting scanning circuits is An infrared receiving component of an infrared receiving scanning circuit receives the detection, and is also detected by an infrared receiving component of another infrared receiving scanning circuit within the receiving range.

2. The infrared touch screen according to claim 1, wherein:

The length of a single infrared transmitting circuit board is twice that of a single infrared receiving circuit board, so that two infrared receiving circuit boards correspond to one infrared transmitting circuit board; or

The infrared transmitting circuit board and the infrared receiving circuit board are equal in number, and the infrared emitting circuit board is divided into a plurality of transmitting scanning units, each of the transmitting scanning units includes a certain number of infrared emitting elements, and the infrared receiving circuit board is also divided into a plurality of receiving scanning units. , one emission scanning unit corresponds to two receiving scanning units.

The infrared touch screen according to claim 1 or 2, wherein: the corresponding relationship between the infrared emitting element and the infrared receiving element comprises a positive correspondence and a non-positive correspondence; and all or most of the infrared emitting elements and/or The infrared receiving element is deflected by a certain angle to install, and can also be realized by selecting a component having a larger emitting angle than a normal infrared component.

The infrared touch screen according to claim 1 or 2, wherein: the infrared radiation receiving and receiving array of the infrared touch screen, the infrared emitting element in the horizontal array, the infrared receiving element, and the infrared emitting element in the vertical array, infrared receiving The frequency of the components is different.

The infrared touch screen according to claim 2, wherein: the timing of the transmitting circuit board/scanning unit is different or the timing of the partially adjacent transmitting circuit board/scanning unit is different, and the timing of the receiving circuit board corresponds to The transmit board timing is consistent.

6. A multi-touch positioning method for an infrared touch screen according to claim 1, comprising the steps of:

1) starting the scan generator to complete the normalization and/or initialization of each infrared receiving component;

2) in a scanning cycle, sequentially turn on the infrared emitting elements, and simultaneously turn on the corresponding infrared receiving elements according to a certain timing correspondence;

3) reading the infrared receiving component output value corresponding to the infrared emitting component for the first time, and comparing with the normalized value and/or the initializing value; if the infrared receiving component output value is inconsistent with the normalized value and/or the initializing value, Then determining that a touch event occurs, marking the location or calculating a position coordinate of a touch point using a normal touch position detection algorithm;

4) Read the output value of the next infrared receiving element corresponding to the same infrared emitting element, and normalize it Comparing the value and/or the initialization value; if the output value of the other infrared receiving component is inconsistent with the normalized value and/or the initialization value, determining that the same infrared emitting component is respectively at an angle with the connection of the two infrared receiving components A touch event occurs in the area, and a touch point pre-detection algorithm is activated to mark an area where the touch event occurs, which is left for further judgment;

5) judging and calculating the position coordinates of each touch point according to the position of the infrared receiving element corresponding to the first time of the infrared emitting element and the position of the area of the pre-detection algorithm mark according to the output value recorded in the scanning period, and The coordinate data is sent to the computer for processing;

6) Start the new cycle by following the steps from step 2) to step 5).

The multi-touch positioning method of the infrared touch screen according to claim 6, wherein in the step 4), the touch is used to predetermine the area where the touch event occurs and calculate the touch of the possible touch point position. The point pre-detection algorithm includes the following steps:

a reading an output value of another infrared receiving element corresponding to the infrared emitting element according to an operation timing of the infrared receiving element;

b. When it is judged that the output value changes, the area where the touch event occurs is marked, and the area is the area between the two infrared receiving elements corresponding to the infrared emitting element that is turned on at the moment;

c. Use the formula to calculate the possible location of the touch event:

Y= X [sin a - sin ( α + β ) ] / ₅ ηη β , where X represents the distance between two infrared receiving elements corresponding to the infrared emitting element, and a represents the infrared receiving element corresponding to the infrared emitting element The angle between the horizontal line and the horizontal line, e represents the angle between the line connecting the infrared emitting element and the corresponding two infrared receiving elements.

8. The multi-touch positioning method of an infrared touch screen according to claim 7, wherein: the position of the infrared receiving element corresponding to the infrared emitting element for the first time corresponds to the infrared emitting element, and the other corresponds to the infrared emitting element. The position of the infrared receiving component is at an angle with the infrared emitting component; the formula for calculating the possible position of the touch event in the touch point pre-detection algorithm is:

γ= X . ctg 9 , wherein X represents the distance between the infrared receiving element corresponding to the infrared emitting element to the infrared receiving element having a certain angle with the infrared emitting element, and the non-positive corresponding infrared receiving element, and Θ indicates the infrared emitting element and the positive Corresponding to the angle between the connection between the infrared receiving elements and the connection between the infrared emitting element and the non-positive corresponding infrared receiving element.

The multi-touch positioning method according to any one of claims 6 to 8, wherein: the scanning detection of the positioning method is performed in two directions of an infrared radiation receiving and receiving array of the infrared touch screen, and The detection data obtained in two directions is integrated into one coordinate or separately transmitted to a computer for processing.

10. An infrared touch screen comprising an infrared emitting element disposed on an infrared emission scanning circuit board and an infrared receiving element disposed on the infrared receiving scanning circuit board, wherein: the infrared emission scanning is performed in at least one detection direction The infrared emitting element on the circuit cannot meet the following correspondence except for the corner portion due to the mounting position. In addition to the relationship, the light emitted by the remaining infrared emitting elements can be received by at least one of the infrared receiving elements on the infrared receiving scanning circuit in a vertically opposite position, and can be at least one offset from the vertical position. The infrared receiving elements on the infrared receiving scanning circuit are received at different times.

11. The infrared touch panel according to claim 10, wherein: the infrared emission scanning circuit in the same detection direction except that the infrared emitting element and/or the infrared receiving element mounted at the corners are not deflectable Both the infrared emitting element on the infrared emitting element and the infrared receiving element on the infrared receiving scanning circuit are deflected at the same angle in the same direction, and the infrared emitting element is opposite to the infrared receiving element.

12. The infrared touch screen according to claim 10, wherein: the infrared radiation receiving and receiving array of the infrared touch screen, the infrared emitting element in the horizontal array, the infrared receiving element, and the infrared emitting element in the vertical array, and the infrared receiving element The frequency is different.

13. An infrared touch screen, characterized in that, in at least one detecting direction, both the infrared emitting element and the infrared receiving element are deflected toward a center of the touch screen, such that the infrared emitting element and the infrared receiving element face oppositely to form a cross-corresponding relationship. : An infrared emitting element vertically corresponds to one infrared receiving element, and is also inclined to correspond to another infrared receiving element, and the infrared receiving element vertically corresponds to one infrared emitting element, and is also inclined to correspond to another infrared emitting element.

14. An infrared touch screen according to claim 13 wherein the main microprocessor is arranged on a receiving circuit board or a transmitting circuit board.

A multi-touch positioning method using the infrared touch screen of claim 10 or 13, characterized in that it mainly comprises the following steps:

a) starting the scan generator, first normalizing and/or initializing the infrared receiving elements vertically opposite the infrared emitting elements, and normalizing and/or initializing the tilting opposite infrared receiving elements, respectively recording the respective infrared receiving elements The tilt normalization value and/or the tilt initialization value and the vertical normalization value and/or the initialization value or the first normalization and/or initialization tilt relative infrared receiving elements are renormalized and/or initialized vertically. a component, respectively recording a tilt normalization value and/or an initialization value and a vertical normalization value and/or an initialization value;

c) calculating the possible position coordinates of each touch point according to the change obtained by comparing the output values of the infrared receiving components with the normalized values and/or the initial values;

d), continue scanning, sequentially turn on and illuminate each of the infrared emitting elements, simultaneously turn on the infrared receiving element at a position opposite to the infrared emitting element, and read the output value of the receiving element opposite to the tilt of the infrared emitting element and normalize with the tilt Comparison of values and/or initialization values; e), according to the change of the output value of each infrared receiving component and the tilt normalized value and/or the initial value, obtain each position parameter, determine the relationship between the actual coordinates X and Y of the touch point, and step c The calculated possible touch point values are substituted into the formula determined by each position parameter to determine the position coordinates of each touch point, and the coordinate data is sent to the computer for processing;

f), according to the method from step b to step e, start a new cycle.

16. A multi-touch positioning method using the infrared touch screen of claim 10 or 13, characterized in that it mainly comprises the following steps:

b), sequentially turning on and illuminating each of the infrared emitting elements, simultaneously turning on the infrared receiving element at a position opposite to the infrared emitting element, and reading the output value of the infrared receiving element obliquely opposite to the infrared emitting element and the normalized value of the tilt And/or the initialization value ratio is obtained according to the change obtained by comparing the output values of the respective infrared receiving elements with the tilt normalized value and/or the initial value, and obtaining each position parameter;

c), sequentially turning on and illuminating each of the infrared emitting elements, simultaneously turning on the infrared receiving element at a position directly opposite to the infrared emitting element, reading the output value of the infrared emitting element and vertically normalizing the value and/or initializing value thereof Comparison

d) calculating the possible position coordinates of each touch point according to the change obtained by comparing the output values of the infrared receiving components with the normalized values and/or the initial values;

e) determining the relationship between the actual coordinates X and Y of the touch point, substituting the possible coordinate values of the touched points calculated in step d into the formula determined by the position parameter of step b, determining the coordinates of each touch point position, and The coordinate data is sent to the computer for processing;

f), according to the method from step b to step e, start a new cycle.

The multi-touch positioning method according to claim 16, wherein when the position coordinates of the respective touch points have been determined according to the method of step b to step d, and are stable, only the vertical scan detection is performed, and the judgment is performed. The trend of motion of each touch point identifies multiple touch points.

18. The multi-touch positioning method according to claim 16, wherein the infrared emission scanning circuit board operates with the same timing, and one detection scanning period is divided into at least two stages, in the first half or the second half of the scanning period. The light emitted by an infrared emitting element is received and detected by an infrared receiving element directly opposite thereto, and the infrared emitting elements are turned on one by one, and the infrared receiving elements vertically opposite thereto are respectively received and detected; in the other half of the scanning Week When the infrared emitting element is lit again, the light emitted by the infrared emitting element is received and detected by another infrared receiving element that is obliquely opposite thereto, and the infrared emitting elements are turned on one by one, and the infrared receiving elements that are opposite to each other are received one by one. Or the infrared receiving scanning circuit board uses the same timing operation, one detection scanning period is divided into at least two stages; in the first half or the second half scanning period, an infrared receiving component receives and detects an infrared from the vertical direction The light emitted by the transmitting element, the infrared receiving elements are turned on one by one, and the infrared emitting elements vertically opposite thereto are illuminated one by one; in the other half of the scanning period, when the infrared receiving element is turned on again, the light it receives is detected. Another infrared emitting element opposite to the tilting, the infrared receiving elements are turned on one by one, and the infrared emitting elements opposite to each other are illuminated one by one.