KR101112630B1 - Digital Apparatus for Touch Screen and Method for Compensating its distorted coordinate Therefore - Google Patents

Abstract

The digital device having the disclosed touch screen includes a touch screen vertically intersecting with a plurality of strip lines, a detector for measuring a voltage applied to a preset reference node of the strip line when a touch occurs on the touch screen, and a preset reference voltage. And a coordinate corrector configured to compare the voltage of the reference node measured by the detector and measure an unintentional coordinate shift value to correct coordinates of an intended contact point.

Touch screen, palm touch, pen touch

Description

Digital Apparatus with Touch Screen and Method of Compensating Touch Coordinates

The present invention relates to a digital device, and more particularly, to a digital device having a touch screen and a coordinate correction method therefor.

Digital devices such as personal computers, portable telephones, and portable small terminals such as portable multimedia playback devices have been increasingly used. Therefore, input devices such as a keyboard and a mouse have limitations in satisfying the needs of consumers.

A touch screen has been introduced as an input device that can solve such a desire. The digital device to which the touch screen is applied includes a touch panel as a monitor, a control unit for controlling various application programs included in the digital device in response to a signal detected by the touch panel, and various devices driven by the control unit. . When a hand or a pen touches the surface of the touch panel, the touch panel recognizes the coordinates of the contact point and processes a function corresponding to the calculated position signal.

The conventional touch screen recognizes only when a single touch point occurs and performs a corresponding function. As the performance of digital devices to which the touch screen is applied varies, recently, even when two or more contacts occur at the same time, the touch screen may be recognized. A multi-touch screen has been developed.

The multi-touch screen is, for example, the upper substrate is divided into a plurality of strip lines, the lower substrate is arranged in a direction perpendicular to the strip line of the upper substrate and the insulation formed between the upper substrate and the lower substrate divided into a plurality of strip lines It can be configured to include a dot, and calculates the coordinates of the contact point by the resistive film method.

1 is a view for explaining the principle of operation of a general multi-touch screen.

1, a vertical touch sensing unit 220 is connected to an upper electrode 12 of an upper substrate 10 including a plurality of strip lines, and a left end of the lower substrate 20 including a plurality of strip lines. The horizontal touch sensing unit 210 is connected to the electrode 22.

The horizontal touch sensing unit 210 includes a plurality of horizontal stripline touch sensing units 212 corresponding to each of the left end electrodes 22, and the vertical touch sensing unit 220 corresponds to each top electrode 12. A plurality of vertical stripline touch sensing unit 222 is included.

Meanwhile, the vertical coordinate calculator 240 is connected to the lower electrode 14 of the upper substrate 10, and the horizontal coordinate calculator 230 is connected to the right electrode 24 of the lower substrate 20.

In order to detect a position where contact is made to the screen, as an example, the upper electrode 12 may be connected to the ground terminal VSS, and the left electrode 22 may be configured as a pull-up. When the screen is in contact with the screen in such a state, the upper substrate 10 in the ground state and the lower substrate 20 in the pull-up state are in contact, so that the potential of the lower substrate 20 is in a ground state, that is, a logical low state. Is changed. The electrical change state change due to the physical change is detected by the horizontal touch detector 210, and when the electrical change is detected, the touch point where the touch is made by the horizontal coordinate calculator 230 and the vertical coordinate calculator 240 is detected.

In addition, since the upper substrate 10 and the lower substrate 20 are composed of a plurality of strip lines, even when a plurality of contact points occur, the plurality of contact points may be individually detected by measuring contact resistance for each strip line.

2 is a view for explaining a method of extracting coordinates when a single contact point occurs.

When a touch is detected on a particular grid cell, an interrupt signal is generated and corresponding striplines of the upper and lower substrates are identified. In order to extract the x-axis coordinate of the touch point P (x, y), a reference voltage is applied to any one of the electrodes 22A and 24A of the horizontal stripline 20A where the touch is sensed and the other electrode is a ground terminal. Connect to (VSS). In addition, either one of the electrodes 12A and 14A of the touch-sensitive vertical stripline 10A is in a floating state, and a resistance extraction circuit is connected to the other electrodes. In the resistance extracting circuit, the x-axis coordinate may be extracted based on the voltage ratio between the third resistor R3 and the fourth resistor R4.

In a similar manner, a reference voltage is applied to any one of the electrodes 12A and 14A of the vertical stripline 10A where the touch is sensed to extract the y-axis coordinates, and the other electrodes are grounded. In addition, any one of the electrodes 22A, 24A of the horizontal stripline 20A on which the touch is sensed is made floating, and a resistance extraction circuit is connected to the remaining electrodes. In the resistance extracting circuit, a resistance value may be calculated using a voltage ratio of the first resistor R1 and the second resistor R2 or a ratio of time delay, and the y-axis coordinate is detected therefrom.

Even when a plurality of contact points are generated, two-dimensional positional information of each contact point can be detected in the same manner as described with reference to FIG. 2. That is, when the lower substrate and the upper substrate are divided into a plurality of strip lines, the position information of each contact point can be accurately detected even when a plurality of contact points are generated by the detection method by the separated strip lines.

By the way, an intended touch and an unintentional touch may simultaneously occur on the multi-touch screen. For example, when a user places a hand on a multi-touch screen for a digitizer work and works with a touch pen, an unintentional touch (hereinafter, palm touch) may serve as an input signal.

FIG. 3 is a diagram for explaining an example in which a pen touch and a palm touch occur at the same time.

As shown in FIG. 3, when the palm touch A occurs simultaneously with the pen touch P (x, y), the horizontal and vertical striplines where the pen touch P (x, y) occurs are palm touches. (A) is independent of the horizontal and vertical stripline that occurred. That is, the change in resistance of the horizontal and vertical striplines in which the palm touch A has occurred does not affect the resistance of the horizontal and vertical striplines in which the pen touch P (x, y) has occurred.

4 is a view for explaining another example when a pen touch and a palm touch occur at the same time.

In comparison with FIG. 3, the horizontal stripline X of the portion where the pen touch P (x, y) occurs is independent of the partial stripline where the palm touch A occurs, but the pen touch P (x, y) The vertical strip line Y of the portion where) is generated overlaps with the strip line of the portion where the palm touch A has occurred.

In this case, the parallel parasitic resistance may be generated by the palm touch A, and an error may occur when calculating the coordinates of the actual pen touch P (x, y) by the parasitic resistance component.

As described above, the resistive touch screen has the advantage that a coil or a dedicated pen is unnecessary as compared to the capacitive touch screen. However, since the input tool is not limited to the pen, it cannot be free from unintentional input signals such as palm touch. .

Moreover, in recent years, touch screens have been applied to electronic books, electronic notes, and the like, and when underlining or writing a book, the influence of palm touch cannot be excluded. Therefore, when the resistance of the stripline is changed by the palm touch as shown in FIG. 4, there is a problem in that the pen touch coordinates cannot be accurately calculated and the user cannot accurately perform the intended operation.

The present invention provides a digital device having a touch screen capable of accurately calculating coordinates by detecting when an unintentional input signal is applied together with a pen touch, and a coordinate correction method for the same.

Another technical problem of the present invention is to provide a digital device having a touch screen capable of accurately performing a user's intended operation when a touch occurs and a coordinate correction method therefor.

A digital device having a touch screen according to an embodiment of the present invention for achieving the above technical problem is a touch screen vertically intersecting a plurality of strip lines; A detector configured to measure a voltage applied to a preset reference node of a corresponding stripline when a touch occurs on the touch screen; And a coordinate corrector configured to compare a preset reference voltage with a voltage of the reference node measured by the detector to correct a coordinate of an intended contact point.

Meanwhile, a coordinate correcting method for a digital device having a touch screen according to an embodiment of the present invention includes a touch screen including a detector connected to a stripline constituting the touch screen and a coordinate corrector connected to the detector. A method of correcting coordinates in a digital device, the method comprising: measuring a reference voltage applied to a preset reference node of the strip line by the coordinate correcting unit when no touch occurs on the touch screen; Measuring an interrupt voltage applied to the reference node by the coordinate corrector when a touch occurs on the touch screen; Comparing the reference voltage with the interrupt voltage; And correcting the coordinates of the intended contact point according to the comparison result.

According to the present invention, when a palm touch occurs together with a pen touch to affect the pen touch, the coordinates of the pen touch may be corrected based on a parasitic component caused by the palm touch. Therefore, the position intended by the user can be detected accurately.

In addition, it is possible to improve the detection reliability of the input signal on the touch screen, and there is an excellent effect that the user can perform the intended operation without error.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

5 is a configuration diagram of a digital device having a touch screen according to an embodiment of the present invention.

As illustrated, the digital device 100 according to an embodiment of the present invention is a digital device having a touch screen 120, and the touch screen 120 may be, for example, a multi-touch screen. The signal input from the touch screen 120 is detected by the touch sensor 130 and the coordinate calculator 140 under the control of the controller 110.

The touch screen 120 may be configured as a stripline type as illustrated in FIG. 1, and the touch sensing unit 130 and the coordinate calculating unit 140 may generate a contact in the manner described above with reference to FIGS. 1 and 2. The stripline can be identified and the coordinates for the contact point can be detected. However, the configuration and coordinate detection method of the touch screen 120 is just an example, and of course, all possible multi-touch screens and coordinate detection methods having a multi-contact point detection function may be introduced.

Meanwhile, the digital device 100 according to the present invention includes a detector 150 and a coordinate corrector 160. When a touch occurs in the touch screen 120, the detector 150 connects the stripline to the ground terminal or measures a voltage applied to a preset reference node.

Meanwhile, when a touch occurs on the touch screen 120, the coordinate corrector 160 receives a voltage of the reference node from the detector 160, and sets a voltage (reference voltage) of the preset reference node and a reference extracted when the touch occurs. By comparing the voltage (interrupt voltage) of the node, it is determined whether an unintended touch has occurred. If an unintended touch occurs, the coordinates of the contact point are corrected based on the changed resistance value.

6 is a configuration diagram of the detector illustrated in FIG. 5.

In an embodiment of the present invention, the detector 150 may include a first switch SW1 connected between the stripline and the ground terminal VSS, a first line connected between the stripline and the reference resistor Rref, as shown in FIG. 6. 2, the switch SW2 may be configured to include an analog / digital converter ADC that measures a voltage applied to the reference resistor Rref, that is, a voltage value applied to the reference node K.

The detector 150 may be connected to the horizontal stripline and the vertical stripline, respectively, or may be shared by the horizontal stripline and the vertical stripline.

When a touch occurs on the touch screen 120, the first switch SW1 is turned on and the second switch SW2 is turned off to calculate the coordinates of the touch point. That is, in the coordinate calculation of the contact point, one electrode of the stripline is connected to the ground terminal and a specific voltage is applied to the other electrode to calculate the coordinates of the contact point by a voltage gradient method.

The first switch SW1 is turned off and the second switch SW2 is turned on to check whether an unintended contact has occurred on the touch screen 120. Accordingly, the voltage applied to the reference node K in the state where no touch occurs and the voltage change state applied to the reference node K when the touch occurs.

FIG. 7 is a configuration diagram of the coordinate correcting unit illustrated in FIG. 5.

As shown in FIG. 7, the coordinate corrector 160 includes a reference voltage determination module 162, an interrupt voltage determination module 164, a comparison module 166, and a correction module 168.

When no contact occurs on the touch screen, the reference voltage determination module 162 turns off the first switch SW1 shown in FIG. 6 and turns on the second switch SW2 to turn on the reference node K. Measure the voltage Vr. On the other hand, when a touch occurs on the touch screen, the interrupt voltage determination module 164 measures the reference node K measured by turning off the first switch SW1 and turning on the second switch SW2 shown in FIG. 6. Measure the voltage Vr '.

The comparison module 166 checks whether the difference between the reference voltage Vr and the interrupt voltage Vr 'is greater than the preset threshold ΔV, and if the threshold is greater than the threshold, the intended touch is affected by the unintended touch. Judging from the situation. That is, it is determined that at least one of the horizontal or vertical strip lines where the pen touch has occurred is overlapped with the horizontal or vertical strip lines where the palm touch has occurred.

Accordingly, the correction module 168 corrects the coordinates with respect to the actual coordinates calculated by the coordinate calculating unit based on the voltage values due to parasitic components generated by the unintended touch.

FIG. 8 is a view for explaining a principle of correcting coordinates according to the present invention and is described with a flowchart for explaining a coordinate correction method for a digital device having a touch screen according to an embodiment of the present invention shown in FIG. 9. Is as follows.

The reference voltage determination module 162 of the coordinate corrector 160 first turns off the first switch SW1 of the detector 150 and turns on the second switch SW2 in a state where a touch does not occur. In operation S10, the voltage Vr applied to the reference node K is measured.

When a touch occurs, the interrupt voltage determination module 164 of the coordinate corrector 160 turns off the first switch SW1 of the detector 150 and turns on the second switch SW2 to the reference node. The voltage Vr 'applied to (K) is measured (S20).

As shown in FIG. 8, when the pen touch P (x, y) and the palm touch A occur at the same time, the horizontal stripline X of the portion where the pen touch P (x, y) occurs is Independent of the partial stripline where the palm touch A has occurred, but the vertical strip line Y of the portion where the pen touch P (x, y) has occurred overlaps with the stripline of the portion where the palm touch A has occurred.

In this case, the parallel parasitic resistance is generated by the palm touch A, and an error occurs during the coordinate calculation of the actual pen touch P (x, y) by the parasitic resistance component.

Therefore, in the present invention, when the pen touch P (x, y) and the palm touch A occur at the same time, the first switch SW1 of the detection unit 150 is turned off and the second switch SW2 is turned on. In this way, the voltage of the reference node K is measured.

In addition, the comparison module 166 of the coordinate correcting unit 160 does not generate any contact with the voltage of the reference node K, that is, the reference voltage Vr and, if a touch occurs, the voltage of the reference node K. That is, the difference Vr-Vr 'of the interrupt voltage Vr' is compared with a predetermined threshold value ΔV (S30).

As a result of the comparison in step S30, when the difference between the reference voltage Vr and the interrupt voltage Vr 'is larger than the threshold value ΔV, the comparison module 166 calculates the coordinates of the pen touch P (x, y). It is determined that there is a palm touch A that affects.

Therefore, it may be determined that there is an error in the Y-axis coordinate Vy 'of the pen touch P (x, y) calculated by turning on the first switch SW1, and the coordinate corrector 160 The correction module 168 corrects the Y-axis coordinate Vy 'according to the ratio of the reference voltage Vr to the interrupt voltage Vr', and calculates the corrected Y-axis coordinate Vy (S40). That is, when the ratio of the reference voltage Vr to the interrupt voltage Vr 'is r, the corrected Y-axis coordinate Vy can be calculated as shown in Equation 1 below.

[Equation 1]

Vy = (1-r) + rVy '

On the other hand, if the palm touch A, which affects the calculation of the coordinates of the pen touch P (x, y), does not exist or only the pen touch is determined as a result of the determination in step S30, the coordinates are directly coordinated by the coordinate calculator. To calculate (S50).

In the above description, a case in which the palm touch exists in the Y-axis direction affects the coordinates of the pen touch, but an error may occur in the X-axis coordinate of the pen touch due to the palm touch generated in the X-axis direction. In this case, of course, the voltage of the reference node can be measured and the coordinates can be corrected.

As such, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without changing the technical spirit or essential features thereof. Therefore, the above-described embodiments are to be understood as illustrative in all respects and not as restrictive. The scope of the present invention is shown by the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

The touch screen has evolved into a multi-touch screen capable of recognizing a plurality of simultaneous contact points.

In this case, an error occurs in the recognition of the coordinates of the intended touch by the unintended touch, and it is necessary to correct the error.In the case of applying the present invention, an unintended touch such as a palm touch coordinates of an intended touch such as a pen touch. In the case of affecting the calculation, the influence of the parasitic component can be removed to accurately recognize the coordinates of the intended touch.

Therefore, the user's intended work can be performed without malfunction, and the operation reliability of the digital device can be improved.

1 is a view for explaining the principle of operation of a general multi-touch screen,

2 is a view for explaining a method of extracting coordinates when a single contact point occurs;

3 is a view for explaining an example when a pen touch and a palm touch occurs at the same time,

4 is a view for explaining another example when a pen touch and a palm touch occurs at the same time,

5 is a configuration diagram of a digital device having a touch screen according to an embodiment of the present invention;

6 is a configuration diagram of the detection unit illustrated in FIG. 5;

7 is a configuration diagram of a coordinate corrector shown in FIG. 5;

8 is a view for explaining the principle of coordinate correction according to the present invention;

9 is a flowchart illustrating a coordinate correction method for a digital device having a touch screen according to an embodiment of the present invention.

Description of the Related Art [0002]

100: digital device 110: control unit

120: touch screen 130: touch detection unit

140: coordinate calculation unit 150: detection unit

160: coordinate correction unit

Claims (11)

A multi touch screen vertically intersecting with a plurality of striplines; A detector configured to measure an interrupt voltage applied to a preset reference node of a corresponding stripline when a touch occurs on the touch screen; And By comparing a predetermined reference voltage and the interrupt voltage measured by the detector, when an unintended contact point occurs, the coordinate of the intended contact point is corrected, and the intended contact point is based on the ratio of the reference voltage to the interrupt voltage. A coordinate corrector for correcting the coordinates of the coordinate; Digital device having a touch screen comprising a. The method of claim 1, The detection unit, if a touch occurs in the touch screen, a digital device having a touch screen, characterized in that for connecting the strip line to the ground terminal for the coordinate calculation of the contact point. The method of claim 2, The detection unit may include a first switch connected between the stripline and the ground terminal; A second switch connected between the stripline and a reference resistor; And An analog / digital converter for measuring a voltage applied to the reference resistor; Digital device having a touch screen comprising a. The method of claim 1, The coordinate corrector compares the reference voltage with the interrupt voltage measured by the detector to determine whether an unintended contact point has occurred, and wherein the interrupt voltage is changed beyond a preset threshold by the unintended contact point. And correcting the coordinates of the intended contact point. The method of claim 4, wherein The detection unit includes a switch connected between the stripline and the reference resistor and an analog / digital converter for measuring the voltage applied to the reference resistor, The coordinate correction unit, A reference voltage determination module for measuring a reference voltage applied to the reference resistance when no touch occurs on the touch screen; An interrupt voltage determination module configured to measure the interrupt voltage applied to the reference resistance when a touch occurs on the touch screen; A comparison module for comparing the reference voltage with the interrupt voltage to determine whether the unintended contact point has occurred; And A correction module for correcting the coordinates of the intended contact point when the unintended contact point occurs as a result of the determination of the comparison module; Digital device having a touch screen comprising a. The method of claim 1, The coordinate corrector determines whether the direction in which the unintended contact points exist is an X-axis direction or a Y-axis direction of the multi-touch screen, Based on the ratio r of the reference voltage Vr to the interrupt voltage Vr ', the Y-axis coordinate Vy' of the intended contact point measured due to the presence of an unintended contact point in the Y-axis direction [ Vy = (1-r) + rVy '], and the X-axis coordinate (Vx') of the intended contact point measured due to the unintended contact point in the X-axis direction is determined by [Vx = (1-r) + rVx '], wherein the digital device has a touch screen. A coordinate correction method in a digital device having a touch screen including a detector connected to a stripline constituting a multi-touch screen and a coordinate corrector connected to the detector, Measuring a reference voltage applied to a preset reference node of the strip line by the coordinate corrector when no contact occurs on the touch screen; Measuring an interrupt voltage applied to the reference node by the coordinate corrector when a touch occurs on the touch screen; Comparing the reference voltage with the interrupt voltage; And Correcting the coordinates of the intended contact point based on the ratio of the reference voltage to the interrupt voltage when there is an unintended contact point as a result of the comparison; Coordinate correction method for a digital device having a touch screen comprising a. The method of claim 7, wherein The detector includes a switch connected between the stripline and a reference resistor and an analog / digital converter for measuring a voltage applied to the reference resistor, and the measuring of the reference voltage and the interrupt voltage may include turning the switch on. And measuring the voltage applied to the reference resistance. The method of claim 8. The comparing of the reference voltage and the interrupt voltage may include comparing whether the difference between the reference voltage and the interrupt voltage is greater than a preset threshold value. The method of claim 7, wherein The correcting coordinates of the intended touch point may include: when the difference between the reference voltage and the interrupt voltage is greater than a preset threshold, the direction in which the unintended touch point exists is an X-axis direction of the multi-touch screen or Y-axis. Determining whether the direction; Based on the ratio r of the reference voltage Vr to the interrupt voltage Vr ', the Y-axis coordinate Vy' of the intended contact point measured due to the presence of an unintended contact point in the Y-axis direction [ Vy = (1-r) + rVy '], and the X-axis coordinate (Vx') of the intended contact point measured due to the unintended contact point in the X-axis direction is determined by [Vx = (1-r) + rVx ']; Coordinate correction method for a digital device having a touch screen comprising a. The method of claim 9, And calculating a coordinate of the intended contact point when the difference between the reference voltage and the interrupt voltage is equal to or less than a preset threshold.

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