CN101339480A - Projection type capacitive touch device and method for identifying different contact positions - Google Patents

Abstract

The invention relates to a projection type capacitive touch device and a method for identifying different contact positions. The different contact positions are generated on the projected capacitive touch panel, and the method comprises the following steps: step 1, generating a first group of reference values according to a first contact position; step 2, generating a plurality of second group reference values according to the second contact position, wherein the plurality of second group reference values have an actual (Real) second group reference value and at least one shadow (Ghost) second group reference value, and the at least one shadow second group reference value comprises a part of values of the first group reference value; and 3, filtering the at least one shadow second set of reference values. The touch device and the identification method can realize the function of detecting multi-point touch and are suitable for being used on a thin or small-sized screen.

Description

Projected capacitive touch device and method for identifying different contact positions

technical field

The present invention relates to a projected capacitive touch device and a method for identifying a contact position thereof; in particular, to a projected capacitive touch device for identifying different contact positions and a method for identifying a contact position thereof.

Background technique

In the past, the communication interface between human and computer or machine was mainly based on keyboard and mouse. With the advancement of science and technology, product design is developing towards a more friendly human-machine interface. Touch panel devices have become quite common input devices and are widely used in personal computers, notebook computers, personal digital assistants, mobile phones, and automatic teller machines. And all kinds of ticket machines, etc. This intuitive input method allows users to easily perform the required functions directly on the screen, which can save the need for keyboards, mice or other additional input devices, thereby reducing the size and weight of application products, and Has a better design.

Currently common touch technologies can be roughly divided into five types of touch technologies: Resistive, Capacitive, Surface Acoustic Wave, Optics, and Electromagnetic. Each control technology has its advantages and disadvantages and is applicable to different fields.

With the development of touch technology, the concept of multi-touch has been proposed and developed. Compared with the traditional single-point input method, the multi-touch input method can allow the user to perform more complex and diversified functional operations, and thus has received considerable attention. Among many touch technologies, resistive and sonic touch technologies are limited by their sensing principles and cannot achieve multi-touch functions. The electromagnetic induction touch technology needs to use a special electromagnetic pen to operate, so it is not conducive to the application of multi-touch. Although the optical sensing touch technology can detect different positions of the multi-touch, but because the corresponding space configuration is required to install the reflective light receiver, the touch system has a large volume, so it is not suitable for thin or small size on the screen.

Based on the above, the capacitive sensing touch technology has become a better choice for achieving multi-touch. Compared with other touch technologies, the capacitive touch technology only needs to be lightly touched by a finger and does not need to apply pressure to touch. In addition, the screen using the capacitive touch technology has the advantages of high resolution and good light transmittance, and is suitable for It can be used on thin and small-sized screens, and can also realize multi-touch functions, so it has become the focus of industry development.

Generally speaking, the capacitive sensing touch technology uses the capacitance change generated by the electrostatic induction between the transparent electrode and the finger, and the current generated at the touch position to detect the coordinates. According to its sensing method, it can be divided into two types: surface capacitive and projective capacitive. However, surface capacitive touch technology can only detect single-point touch at present, and only projected capacitive touch technology The function of detecting multi-touch can be realized.

FIG. 1 is a schematic structural diagram of a known projected capacitive touch device 1 . The projected capacitive touch device 1 includes a protective layer 11 , a display device 12 , a projected capacitive touch panel 13 and a controller 14 . The protection layer 11 is a transparent material, located on the uppermost layer of the projected capacitive touch device 1 . The display device 12 is located at the bottom layer of the projected capacitive touch device 1 and projects an image upward. The projected capacitive touch panel 13 is located between the protective layer 11 and the display device 12 , and is electrically connected to the controller 14 .

Please refer to FIG. 2 , the projected capacitive touch panel 13 has two sets of sensing electrodes that are not parallel to each other. The two sets of sensing electrodes cross each other and correspond to different coordinate axes. Each set of sensing electrodes has a plurality of sensing electrodes. For example, the projected capacitive touch panel 13 has a plurality of X-axis sensing electrodes 131 and a plurality of Y-axis sensing electrodes 132 , wherein one X-axis sensing electrode 131 x and the Y-axis sensing electrode 132 y intersect at the contact position 133 .

Because there is static electricity on the finger, when the user touches the protective layer 11 with the finger, at the contact position 133 corresponding to the touch position on the projected capacitive touch panel 13, a change in the sensing capacitance value and a potential difference will be generated, and This makes the X-axis sensing electrode 131x and the Y-axis sensing electrode 132y passing through the contact position 133 generate a potential change and a small induced current. By detecting this potential change and/or induced current, the projected capacitive touch panel 13 can generate a set of reference signals, and transmit the set of reference signals to the controller 14, and the controller 14 generates a set of coordinate values according to the set of reference signals . According to the set of coordinate values, the application program can determine the function that the user wants to execute.

FIG. 3 is a schematic diagram of a user simultaneously touching two points on the projected capacitive touch device 1 . When the user touches two different positions on the protection layer 11 at the same time, a sensing capacitance will be generated on the projected capacitive touch panel 13 corresponding to the first contact position 133 a and the second contact position 133 b. Therefore, the first X-axis sensing electrode 131a and the first Y-axis sensing electrode 132a intersecting at the first contact position 133a will respectively generate potential changes and induced currents, and the second X-axis sensing electrode 131b and the first Y-axis sensing electrode 132a intersecting at the second contact position 133b The two Y-axis sensing electrodes 132b also generate induced currents respectively.

However, in this situation, the projected capacitive touch panel 13 will simultaneously detect potential changes and/or induced currents respectively corresponding to two X coordinate axes and two Y coordinate axes, which respectively correspond to two X coordinate values and Two Y coordinate values. The plurality of X coordinate values and Y coordinate values can be arbitrarily combined into four contact positions respectively representing the first contact position 133a, the second contact position 133b, the third contact position 133c and the fourth contact position 133d, wherein the first The third contact position 133c and the fourth contact position 133d are shadow contact positions, which means they are not actually clicked by the user. Since the controller 14 cannot distinguish which of the aforementioned four contact positions is the position actually clicked by the user according to the multiple X coordinate values and Y coordinate values, that is, it has no ability to distinguish the first contact position 133a and the second contact position 133b, The projected capacitive touch device 1 cannot perform the multi-touch operation function.

In view of this, it is an urgent problem to be solved in the industry to provide a projected capacitive touch device with the function of identifying different contact positions and a method for identifying different contact positions.

Contents of the invention

The object of the present invention is to provide a method for identifying different contact positions generated on a projected capacitive touch panel. The method includes the following steps: Step 1. Generate a first set of reference values according to the first contact position ; Step 2 generates a plurality of second sets of reference values according to the second contact position, wherein the plurality of second sets of reference values has an actual second set of reference values and at least one shadow second set of reference values, and the at least one The shadow second set of reference values includes a part of the first set of reference values; and step 3 filtering out the at least one shadow second set of reference values.

In said method, wherein the step 1 is to generate a first set of coordinate values according to the first contact position; the step 2 is to generate a plurality of second set of coordinate values according to the second contact position.

In said method, wherein the step 1 is to generate a first group of two-dimensional coordinate values according to the first contact position; the step 2 is to generate three second group of two-dimensional coordinate values according to the second contact position, It has the actual second set of two-dimensional coordinate values and two shadow second set of two-dimensional coordinate values, each of the shadow second set of two-dimensional coordinate values includes one of the first set of two-dimensional coordinate values.

In said method, after step 2, the following step is further included: confirming that the difference between the actual second set of reference values and the first set of reference values is greater than a threshold value.

In said method, step 1 includes the following steps: confirming the first contact position in a first scan cycle.

In said method, the step 2 includes the following steps: confirming the second contact position in a second scanning cycle.

In said method, the following steps are further included: generating a first set of continuous reference value series according to the first trajectory of the movement of the first contact position.

In said method, the following steps are further included: generating a second set of continuous reference value sequences according to the second trajectory of the movement of the second contact position.

Another object of the present invention is to provide a projected capacitive touch device, comprising: a projected capacitive touch panel, used to generate a reference signal according to a contact position; a controller, connected to the projected capacitive touch panel, for According to the first reference signal generated by the first contact position, a first set of reference values is generated, and according to the second reference signal generated by the second contact position, a plurality of second sets of reference values are generated, wherein the plurality of second sets a reference value having an actual second set of reference values and at least one shadow second set of reference values, the at least one shadow second set of reference values comprising a portion of the first set of reference values; and a processor configured to filter out The at least one shadow second set of reference values.

In the projected capacitive touch device, the controller generates a first set of coordinate values and a plurality of second set of coordinate values respectively according to the first contact position and the second contact position.

In the projected capacitive touch device, wherein the controller generates a first two-dimensional coordinate value and three second two-dimensional coordinate values respectively according to the first contact position and the second contact position, It has the actual second set of two-dimensional coordinate values and two shadow second set of two-dimensional coordinate values, each of the shadow second set of two-dimensional coordinate values includes one of the first set of two-dimensional coordinate values.

In the projected capacitive touch device, the processor is further configured to confirm that the difference between the actual second set of reference values and the first set of reference values is greater than a threshold.

In the projected capacitive touch device, the controller confirms the first contact position within a first scan period.

In the projected capacitive touch device, the controller confirms the second contact position in a second scanning period.

In the projected capacitive touch device, the controller further generates a first set of continuous reference value series according to the first trajectory of the movement of the first contact position.

In the projected capacitive touch device, the controller further generates a second set of continuous reference value sequences according to the second trajectory of the second contact position movement.

In the projected capacitive touch device, the first scanning period is greater than 80 Hz.

In the projected capacitive touch device, the second scanning period is greater than 80 Hz.

Another object of the present invention is to provide a projected capacitive touch device, comprising: generating means for generating a first set of reference values according to the first contact position, and generating a plurality of second reference values according to the second contact position A set of reference values, wherein the plurality of second set of reference values has an actual second set of reference values and at least one shadow second set of reference values, and the at least one shadow second set of reference values includes the first set of reference values a part of the values; and filtering means for filtering out the at least one shadow second set of reference values.

In the projected capacitive touch device, the generating means respectively generates a first set of coordinate values and a plurality of second sets of coordinate values according to the first contact position and the second contact position.

In the projected capacitive touch device, wherein the generating means respectively generates a first group of two-dimensional coordinate values and three second group of two-dimensional coordinate values according to the first contact position and the second contact position, It has the actual second set of two-dimensional coordinate values and two shadow second set of two-dimensional coordinate values, each of the shadow second set of two-dimensional coordinate values includes one of the first set of two-dimensional coordinate values.

In the projected capacitive touch device, the generating means is further used to confirm that the difference between the actual second set of reference values and the first set of reference values is greater than a threshold value.

In the projected capacitive touch device, the generating means confirms the first contact position in a first scan period.

In the projected capacitive touch device, the generating means confirms the second contact position in a second scanning period.

In the projected capacitive touch device, the generating means is further used to generate a first set of continuous reference value series according to the first trajectory of the first contact position movement.

In the projected capacitive touch device, the generating means is further used to generate a second set of continuous reference value sequences according to the second trajectory of the second contact position movement.

In the projected capacitive touch device, the first scanning period is greater than 80 Hz.

In the projected capacitive touch device, the second scanning period is greater than 80 Hz.

The invention realizes the function of detecting multi-point touch, and is suitable for use on thin or small-size screens.

In order to make the above objects, technical features, and advantages of the present invention more comprehensible, preferred embodiments are described in detail below with accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram of a known projected capacitive touch device;

2 is a schematic diagram of a single-point touch of a known projected capacitive touch device;

FIG. 3 is a multi-touch schematic diagram of a known projected capacitive touch device;

4 is a schematic diagram of a projected capacitive touch device of the present invention;

5 is a schematic diagram of the operation of the projected capacitive touch device of the present invention;

Fig. 6 is a flow chart of the method for identifying different contact positions according to the present invention.

Wherein, the reference signs are explained as follows:

1 Projected capacitive touch device 11 Protective layer

12 Display device 13 Projected capacitive touch panel

131X-axis sensing electrode 131xX-axis sensing electrode

131a The first X-axis sensing electrode 131b The second X-axis sensing electrode

132Y-axis induction electrode 132yY-axis induction electrode

132a The first Y-axis sensing electrode 132b The second Y-axis sensing electrode

133 contact position 133a first contact position

133b second contact position 133c third contact position

133d fourth contact position 14 controller

2 Projected capacitive touch device 21 Projected capacitive touch panel

22 Controllers 23 Processors

24 First contact position 25 Second contact position

25a First shadow contact position 25b Second shadow contact position

Detailed ways

FIG. 4 is a schematic structural diagram of a projected capacitive touch device of the present invention. The projected capacitive touch device 2 includes a projected capacitive touch panel 21 , a controller 22 and a processor 23 . The projected capacitive touch panel 21 can sense the user's touch, and generate a reference signal according to the touch position. The controller 22 is connected to the projected capacitive touch panel 21 and the processor 23 respectively, and can generate at least one reference value according to the reference signal generated by the projected capacitive touch panel 21 . Processor 23 may receive and filter the reference value.

FIG. 5 is a schematic diagram of multi-touch operation. When the user touches different first contact positions 24 and second contact positions 25 on the projected capacitive touch device 2 at the same time, usually there is a time difference between the two touches, that is, different fingers of the user will first It touches the first contact position 24 and then touches the second contact position 25 . In order to realize the function of identifying different contact positions, the projected capacitive touch device 2 of the present invention has a scanning period. By reducing the scanning period to less than the contact time difference, the projected capacitive touch device 2 can make different contacts fall on different positions. In the scan cycle, to identify the contact sequence of different contact positions. That is, the controller 22 confirms the first contact position 24 in the first scan period, and confirms the second contact position 25 in the second scan period. In practice, the scanning period is preferably less than 0.0125 seconds, that is, the scanning frequency is preferably greater than 80 Hz, so that the projected capacitive touch device 2 can more effectively identify the contact sequence of different contact positions.

When the first contact position 24 is touched within the first scanning period, the projected capacitive touch panel 21 generates a first reference signal according to the first contact position 24 and transmits the first reference signal to the controller 22 . After the controller 22 confirms the first reference signal of the first contact position 24 in the first scan period, it generates a corresponding first set of reference values according to the first reference signal generated by the first contact position. The first set of reference values may be a first set of coordinate values, and the first set of coordinate values may be one of a set of two-dimensional coordinate values, a set of three-dimensional coordinate values, and other dimensional coordinate values. In this embodiment, the first set of reference values is the first set of two-dimensional coordinate values.

Next, when the second contact position 25 is touched within the second scanning period, the projected capacitive touch panel 21 will generate and transmit a second reference signal including the second contact position 25 to the controller 22 . The controller 22 generates a plurality of second sets of reference values according to the second reference signal. Likewise, the multiple second sets of reference values can be multiple second sets of coordinate values, and any of the multiple second sets of coordinate values can be a set of two-dimensional coordinate values, a set of three-dimensional coordinate values, and other dimensions One of the coordinate values. In this embodiment, the multiple second sets of reference values are multiple second sets of two-dimensional coordinate values.

Based on the above, analyzing the above-mentioned first set of reference values and multiple second sets of reference values, it can be known that they include the first set of reference values corresponding to the first contact position 24 and the actual first set of values corresponding to the second contact position 25. Two sets of reference values, and at least one shadow second set of reference values. The at least one shadow second set of reference values includes a part of the first set of reference values and corresponds to a shadow contact position that is not actually touched.

Please refer to FIG. 5 , the second set of reference values in this embodiment includes two sets of shadow second reference values, which correspond to the first shadow contact position 25a and the second shadow contact position 25b respectively. Specifically, the second set of reference values of the two sets of shadows is the second set of two-dimensional coordinate values of the two sets of shadows, and each of the second set of two-dimensional coordinate values of the shadows includes a part of the first set of two-dimensional coordinate values coordinate value.

After receiving the second set of reference values generated by the controller 22, the processor 23 will refer to the coordinates of the first set of reference values to identify and filter out the shadow second set of reference values among the second set of reference values. numerical values to derive the actual second set of reference values.

However, when the user performs a single touch function, if the area of a single touch point is too large, it may cause the projected capacitive touch panel 21 to judge that it is a plurality of touch positions, thereby generating a second set of reference signals, and A plurality of second sets of reference values are generated via the controller 22 . In order to avoid the above situation, the processor 23 will compare the actual second set of reference values with the first set of reference values, and only when it is confirmed that the difference between the first set of reference values and the second set of reference values is greater than the threshold Assume it is multi-touch and not false touch.

FIG. 6 is another embodiment of the present invention, which is a flowchart of a method for identifying different contact positions. This embodiment is applicable to the aforementioned projected capacitive touch device. The process of the method will be described below by taking the projected capacitive touch device 2 as an example. In step 601, the controller 22 confirms the first contact position 24 in the first scanning period, and then in step 602, the controller 22 generates a corresponding first contact position 24 according to the first reference signal generated by the first contact position 24. A set of reference values. In step 603, the controller 22 confirms the second contact position 25 in the second scanning cycle, and then in step 604, the controller 22 generates a corresponding A plurality of second sets of reference values. In step 605, the processor 23 will refer to the coordinates of the first set of reference values to identify and filter out at least one of the second set of reference values that is a shadow second set of reference values to obtain the actual second set of reference values. value. Then in step 606, the processor 23 compares the first set of reference values with the actual second set of reference values, and when it is confirmed that the difference between the first set of reference values and the second set of reference values is greater than the threshold value, it is determined It is a multi-touch and not a false touch.

Through the above projected capacitive touch device and the method for identifying the contact position, the multi-touch position on the touch device can be identified. Further applications, such as judging operation gestures on a touch device, can also be implemented by this method. When a finger performs multi-touch on the touch device and touches the touch position, the projected capacitive touch panel 21 can generate a first continuous reference signal according to the first trajectory of the movement of the first touch position, and the controller 22 can generate a first continuous reference signal according to The first continuous reference signal generates a first series of continuous reference values. Similarly, the projected capacitive touch panel 21 can generate a second continuous reference signal according to the second movement track of the second contact position, and the controller 22 can generate a second set of continuous reference value series according to the second continuous reference signal. The processor 23 performs corresponding control according to the first set of continuous reference value sequences and the second set of continuous reference value sequences, such as enlarging a partial image, closing a current image, and the like.

The above-mentioned embodiments are only used to list the implementation manners of the present invention and explain the technical features of the present invention, and are not intended to limit the scope of protection of the present invention. Any changes or equivalence arrangements that can be easily accomplished by those skilled in the art fall within the scope of the present invention, and the protection scope of the present invention should be determined by the claims.

Claims (28)

1. A method for identifying different contact locations generated on a projected capacitive touch panel, the method comprising the following steps: Step 1. Generate a first set of reference values according to the first contact position; Step 2. According to the second contact position, a plurality of second sets of reference values are generated, wherein the plurality of second sets of reference values have an actual second set of reference values and at least one shadow second set of reference values, and the at least one a shadow second set of reference values comprising a portion of the first set of reference values; and Step 3. Filter out the at least one shadow second set of reference values. 2. The method according to claim 1, wherein the step 1 is to generate a first set of coordinate values according to the first contact position; the step 2 is to generate a plurality of second set of coordinate values according to the second contact position . 3. The method according to claim 2, wherein the step 1 is to generate a first group of two-dimensional coordinate values according to the first contact position; the step 2 is to generate three second groups of two-dimensional coordinates according to the second contact position A two-dimensional coordinate value, which has an actual second set of two-dimensional coordinate values and two shadow second set of two-dimensional coordinate values, each of the second set of shadow two-dimensional coordinate values includes one of the first set of two-dimensional coordinate values Dimensional coordinate value. 4. The method according to claim 1, wherein after the step 2, further comprising the following steps: It is confirmed that the difference between the actual second set of reference values and the first set of reference values is greater than a threshold value. 5. The method of claim 1, wherein step 1 comprises the steps of: The first contact location is identified during a first scan cycle. 6. method as claimed in claim 5, wherein this step 2 comprises the following steps: The second contact location is confirmed during a second scan cycle. 7. The method of claim 1, further comprising the steps of: According to the first trajectory of the movement of the first contact position, a first set of continuous reference value series is generated. 8. The method of claim 1, further comprising the steps of: According to the second trajectory of the movement of the second contact position, a second set of continuous reference value series is generated. 9. A projected capacitive touch device, comprising: A projected capacitive touch panel for generating a reference signal according to a touch position; The controller, connected to the projected capacitive touch panel, is used to generate a first set of reference values according to the first reference signal generated at the first contact position, and to generate multiple sets of reference values according to the second reference signal generated at the second contact position. A second set of reference values, where, the plurality of second set of reference values having an actual second set of reference values and at least one shadow second set of reference values, the at least one shadow second set of reference values comprising a portion of the first set of reference values; and A processor, configured to filter out the at least one shadow second set of reference values. 10 . The projected capacitive touch device as claimed in claim 9 , wherein the controller generates a first set of coordinate values and a plurality of second set of coordinate values according to the first touch position and the second touch position respectively. 11 . 11. The projected capacitive touch device according to claim 10, wherein the controller generates a first set of two-dimensional coordinate values and three second sets of two-dimensional coordinates according to the first touch position and the second touch position, respectively. A two-dimensional coordinate value, which has an actual second set of two-dimensional coordinate values and two shadow second set of two-dimensional coordinate values, each of the second set of shadow two-dimensional coordinate values includes one of the first set of two-dimensional coordinate values Dimensional coordinate value. 12. The projected capacitive touch device as claimed in claim 9, wherein the processor is further configured to confirm that the difference between the actual second set of reference values and the first set of reference values is greater than a threshold. 13. The projected capacitive touch device as claimed in claim 9, wherein the controller confirms the first contact position in a first scan period. 14. The projected capacitive touch device as claimed in claim 13, wherein the controller confirms the second contact position in a second scan period. 15 . The projected capacitive touch device as claimed in claim 9 , wherein the controller further generates a first set of continuous reference value series according to the first trajectory of the movement of the first contact position. 16 . The projected capacitive touch device as claimed in claim 9 , wherein the controller further generates a second set of continuous reference value series according to the second trajectory of the movement of the second contact position. 17. The projected capacitive touch device as claimed in claim 13, wherein the first scanning period is greater than 80 Hz. 18. The projected capacitive touch device as claimed in claim 14, wherein the second scanning period is greater than 80 Hz. 19. A projected capacitive touch device, comprising: generating means for generating a first set of reference values according to the first contact position, and generating a plurality of second sets of reference values according to the second contact position, wherein, the plurality of second set of reference values having an actual second set of reference values and at least one shadow second set of reference values, the at least one shadow second set of reference values comprising a portion of the first set of reference values; and The filtering means is used for filtering out the at least one shadow second set of reference values. 20 . The projected capacitive touch device according to claim 19 , wherein the generating means respectively generates a first set of coordinate values and a plurality of second set of coordinate values according to the first touch position and the second touch position. 21. The projected capacitive touch device as claimed in claim 20, wherein the generating means respectively generates a first group of two-dimensional coordinate values and three second groups of two-dimensional coordinates according to the first contact position and the second contact position. A two-dimensional coordinate value, which has an actual second set of two-dimensional coordinate values and two shadow second set of two-dimensional coordinate values, each of the second set of shadow two-dimensional coordinate values includes one of the first set of two-dimensional coordinate values Dimensional coordinate value. 22. The projected capacitive touch device as claimed in claim 19, wherein the generating means is further used to confirm that the difference between the actual second set of reference values and the first set of reference values is greater than a threshold value. 23. The projected capacitive touch device as claimed in claim 19, wherein the generating means confirms the first contact position within a first scan period. 24. The projected capacitive touch device as claimed in claim 23, wherein the generating means confirms the second contact position within a second scanning period. 25. The projected capacitive touch device as claimed in claim 19, wherein the generating means is further used for generating a first set of continuous reference value series according to the first trajectory of the movement of the first contact position. 26. The projected capacitive touch device as claimed in claim 19, wherein the generating means is further used to generate a second set of continuous reference value sequences according to the second trajectory of the second contact position movement. 27. The projected capacitive touch device as claimed in claim 23, wherein the first scanning period is greater than 80 Hz. 28. The projected capacitive touch device as claimed in claim 24, wherein the second scanning period is greater than 80 Hz.

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