TWI457817B - Zoom gesture determination method and touch control chip - Google Patents

Description

Zoom gesture determination method and touch sensing control chip

The present invention relates to a zoom gesture determination method and a touch sense control chip, and more particularly to a zoom gesture determination method that can be used for a self-capacitative touch sensing device, and a related touch sensing control chip.

The touch device has the advantages of convenient operation, fast response speed and space saving, and can provide a more intuitive and convenient control mode for the user, and thus becomes an important input interface, and is widely used in various consumer electronic products. Specifically, the touch device is a sensing circuit and a plurality of traces arranged in a matrix manner, and the sensing circuit can sense the electrical signals of the traces and convert them into digital sensing data values. Interpret the touch event. However, the conventional touch device is mainly suitable for single touch, and if it is for multi-touch, it may face the problem of misjudgment.

For example, please refer to FIG. 1 , which is a schematic diagram of a conventional projected capacitive sensing device 10 . The projected capacitance sensing device 10 includes an inductive capacitance series X ₁ to X _m and Y ₁ to Y _n , and each of the sensing capacitance series is a one-dimensional structure in which a plurality of sensing capacitors are connected in series. The conventional touch detection method is to detect the capacitance value of each sensing capacitor string to determine whether a touch event occurs. Assuming that the sense capacitor series X ₁ has a sense capacitor, and the capacitance of each sense capacitor is C, the capacitance value of the sense capacitor string X ₁ is normally aC. If the human body (for example, a finger) touches a certain sensing capacitance on the sensing capacitor string X ₁ , the capacitance change amount is ΔC, and when the capacitance value of the sensing capacitor string X ₁ is detected (aC+ΔC), That is to say, the finger is currently in contact with somewhere on the sensing capacitor string X ₁ . However, in the case of multi-touch, as shown in FIG. 1, since two fingers are in contact with the projected capacitance sensing device 10, the sensing capacitance series X ₃ , X _m-1 , Y ₃ , Y _n-1 At the same time, a change in capacitance is sensed, and thus it will be judged as being at (X ₃ , Y ₃ ), (X ₃ , Y _n-1 ), (X _m-1 , Y ₃ ), (X _m-1 , Y _{n- 1} ) There is a touch event happening. However, in reality, only (X ₃ , Y ₃ ) and (X _m-1 , Y _n-1 ) are true touch points, while (X ₃ , Y _n-1 ), (X _m-1 , Y ₃ ) Not a real touch point. In this case, the projected capacitance sensing device 10 has a result of erroneous determination, and the detection result falsely reports two non-real touch points, that is, a situation called a ghost key. Therefore, when there is a multi-touch situation (such as when performing a zoom gesture), it is only known that there may be a touch event at the intersection of the sensing capacitors, and the actual touch point and zoom cannot be surely determined. gesture.

Therefore, the main object of the present invention is to provide a zoom gesture determination method and a touch sensing control chip.

The invention discloses a zoom gesture judging method for a touch sensing device. The zoom gesture determining method includes detecting a first touch point and a second touch point, determining a position difference between the first touch point and a second touch point, and determining the position difference according to the position difference. The change of the value determines a zoom gesture represented by the first touch point and the second touch point.

The invention further discloses a touch sensing control chip for a touch sensing device. The touch sensing control chip includes a detecting unit for detecting a first touch point and a second touch point, and a determining unit for determining the first touch point and a second touch point A position difference between the two, and a determining unit, configured to determine a zoom gesture represented by the first touch point and the second touch point according to the change of the position difference.

Please refer to FIG. 2 , which is a block diagram of a touch sensing system 20 according to an embodiment of the present invention. The touch sensing system 20 is composed of a touch sensing device 200 and a touch sensing control chip 202. The touch sensing control chip 202 includes a detecting unit 206, a determining unit 208, and a determining unit 210. The detecting unit 206 is configured to detect a first touch point T1 and a second touch point T2 according to the detection signals CX ₁ - CX _m and CY ₁ - CY _n from the touch sensing device 200. The determining unit 208 further determines a position difference D between the first touch point T1 and the second touch point T2. Finally, the determining unit 210 determines one of the zoom gestures ZG represented by the first touch point T1 and the second touch point T2 according to the change of the position difference D. The detecting unit 206 detects the first touch point T1 and the second touch point T2 according to the detection signals CX ₁ ～ CX _m and CY ₁ ～ CY _n from the touch sensing device 200. The projected capacitance sensing device 10 is similar. However, unlike the case where the conventional capacitive sensing device generates a ghost key in the case of multi-touch, so as to cause a misjudgment of the zoom gesture, the determining unit 210 transmits the first touch point T1 and the second touch point T2. The change in position difference D between them determines the zoom gesture ZG. Therefore, the touch sensing control chip 202 can be combined with two sensing modes of the touch sensing device 200 such as self-capacitance or mutual-capacitance to determine the zoom gesture ZG.

For details, please refer to FIG. 3 . FIG. 3 is a schematic diagram of the touch sensing control chip 202 in FIG. 2 detecting the position difference D between the two touch points T1 and T2 . As shown in FIG. 3, the determining unit of the touch sensing control chip 202 determines a horizontal position difference ΔX and a vertical position difference ΔY between the first touch point T1 and the second touch point T2, respectively. To determine the position difference D between the first touch point T1 and the second touch point T2. When the position difference D is continuously incremented or decremented, the touch sensing control chip 202 can determine a zoom gesture ZG represented by the first touch point T1 and the second touch point T2, respectively, or a zoom-in or a Zoom out gestures. The purpose of judging the zoom gesture ZG by continuously increasing or decreasing the position difference D is to avoid a coordinate bounce phenomenon during the zoom gesture operation, resulting in a false positive. Taking FIG. 3 as an example, when the first touch point T1 and the second touch point T2 move to the upper left and lower right directions respectively, the horizontal position difference between the first touch point T1 and the second touch point T2 The value ΔX and the vertical position difference ΔY are respectively increased, and the position difference D is also increased. Therefore, the determining unit 210 can determine that the zoom gesture ZG represented by the first touch point T1 and the second touch point T2 is a zoom-in gesture. However, if one of the first touch point T1 and the second touch point T2 leaves the touch sensing device 200, the determining unit 210 determines that the position difference D does not exhibit a continuous change, and thus determines that the zoom gesture ZG is not present. occur.

In addition, when the self-capacitance sensing mode is used, the diagonal direction of the two-finger touch touch sensing device 200 may occur, so that the determining unit 210 misjudges the two horizontal touch points or the two vertical touch points. Please refer to FIG. 4A and FIG. 4B. FIG. 4A and FIG. 4B are schematic diagrams showing a misjudgment situation when the touch sensing chip 202 of FIG. 2 is combined with a self-capacitance sensing touch sensing device. In FIG. 4A, two fingers touch two points (X _m-1 , Y ₃ ), (X ₃ , Y _n+1 ) on the touch sensing device 200, respectively, but one of the vertical coordinates Y _{n +1} has exceeded the detection range of one of the vertical sensing capacitor strings Y ₁ ～ Y _n of the touch sensing device 200. Therefore, at this time, only the sense capacitor series X ₃ , X _m-1 , and Y ₃ will sense the capacitance change at the same time, and thus the error is judged at two points (X ₃ , Y ₃ ), (X _m-1 , Y ₃ ). A touch event has occurred. That is to say, when determining the position difference between the two touch points, the determining unit 208 will misjudge the vertical position difference ΔY between the two points to be zero, which will cause misjudgment when the subsequent zoom gesture is judged. . For the same reason, please refer to FIG. 4B. When the two fingers touch the two points (X ₀ , Y _n-1 ), (X _m-1 , Y ₃ ) on the touch sensing device 200 respectively, the horizontal coordinates of one of the fingers X ₀ has exceeded the detection range of the horizontal sensing capacitor series X ₁ to X _n of the touch sensing device 200. Therefore, only the sense capacitor series X _m-1 , Y ₃ , and Y _n-1 will sense the change of capacitance at the same time, so the error is judged at (X _m-1 , Y ₃ ), (X _m-1 , Y _N-1 ) Two touch events occurred. That is to say, when judging the position difference between the two touch points, the judging unit 208 will misjudge the horizontal position difference ΔX between the two points to be zero, which will cause a misjudgment when the subsequent zoom gesture is judged.

Therefore, the determining unit 210 of the embodiment of the present invention further utilizes a de-bounce mechanism to filter out the diagonally opposite angles of the two-finger touch sensing device 200, but the two horizontal touch points or the two vertical touches have a short error. Point to the situation, and thereby overcome the innate physical characteristics of the self-capacitance sensing method. Specifically, the detecting unit 206 first detects whether the first touch point T1 and the second touch point T2 are both present. If the detecting unit 206 detects that there is only a single touch point or no touch point on the touch sensing device 200, the bounce mechanism can be directly ended, and no subsequent judgment is needed. If the detecting unit 206 detects that both the first touch point T1 and the second touch point T2 are present, the determining unit 208 determines the horizontal position difference between the first touch point T1 and the second touch point T2. The X or the vertical position difference ΔY is not zero, which means that the two touch points are located at an oblique diagonal position on the touch sensing device 200, and both are in the horizontal and vertical sensing capacitance series X ₁ ～X _n , Y The detection range of ₁ ~ Y _n can also end the bounce mechanism for normal zoom gesture judgment. However, if the determining unit 208 determines that one of the horizontal position difference ΔX or the vertical position difference ΔY between the first touch point T1 and the second touch point T2 is zero, the first touch needs to be further determined. Whether the handle point T1 and the second touch point T2 are actually arranged horizontally or vertically, or one of them has exceeded the detection range of the touch sensing device 200, causing a false positive. Therefore, a counter can be used to count the number of times the horizontal position difference ΔX or the vertical position difference ΔY between the first touch point T1 and the second touch point T2 is zero to generate an accumulated value. If the accumulated value is greater than a threshold, it is determined that the first touch point T1 and the second touch point T2 are actually horizontally or vertically aligned.

For example, if the first touch point T1 and the second touch point T2 are respectively located at the position shown in FIG. 4A and the threshold value is 3, at the beginning, the determining unit 208 determines the first touch. The horizontal position difference ΔX between the point T1 and the second touch point T2 is zero, and the cumulative value of the counter is incremented. If the first touch point T1 and the second touch point T2 are gradually approaching, when the first touch point T1 enters the vertical detection range of the touch sensing device 200 again, the accumulated value is reset to zero, and the determining unit 208 is correct. It is determined that the first touch point T1 and the second touch point T2 are arranged diagonally diagonally instead of horizontally. Therefore, the determining unit 210 can also correctly determine that the ZG gesture is a zoom-out gesture. On the other hand, if the two touch points are located at the positions of T1' and T2 shown in FIG. 4A and are away from each other in the horizontal direction, the counter will gradually count the number of times the vertical position difference ΔY between T1' and T2 is zero. When the accumulated value exceeds the critical value of 3, the determining unit 208 and the determining unit 210 can correctly determine that T1' and T2 are indeed horizontally arranged, and represent a zoom-in gesture without a misjudgment. In this way, the two-finger touch sensing device 200 can be filtered diagonally, but the two horizontal touch points or the two vertical touch points of the short-term error occur.

It should be noted that the main purpose of the present invention is to determine the zoom gesture by using the change in the position difference, and all the changes made in this manner are within the scope of the present invention. In addition, the determining unit 210 determines the zoom gesture ZG according to the change of the position difference, which can be summarized into a zoom gesture determining process 50. As shown in FIG. 5, the method includes the following steps:

Step 500: Start.

Step 502: Detect the first touch point T1 and the second touch point T2.

Step 504: Determine a position difference D between the first touch point T1 and the second touch point T2.

Step 506: When the position difference D is continuously incremented or decremented, it is determined that the zoom gesture ZG represented by the first touch point T1 and the second touch point T2 is an enlargement or reduction gesture.

Step 508: End.

Similarly, the operation of the De-bounce mechanism can be summarized as a bounce mechanism process 60, as shown in Figure 6, which includes the following steps:

Step 600: Start.

Step 602: Determine whether there is a first touch point T1 and a second touch point T2 on the touch sensing device 200. If yes, go to step 604; if no, go to step 610.

Step 604: Determine whether the horizontal position difference ΔX and the vertical position difference ΔY between the first touch point T1 and the second touch point T2 are not zero. If yes, go to step 610; if no, go to step 606.

Step 606: Count the number of times the horizontal position difference ΔX and the vertical position difference ΔY between the first touch point T1 and the second touch point T2 are not zero, to generate an accumulated value. If the accumulated value is greater than a threshold, proceed to step 608; if no, proceed to step 612.

Step 608: Determine that the first touch point T1 and the second touch point T2 are horizontal according to the horizontal position difference ΔX and the vertical position difference ΔY between the first touch point and the second touch point. Or arranged vertically.

Step 610: Zero the accumulated value.

Step 612: End.

For a detailed description or change of the zoom gesture determination process 50 or the bounce jump mechanism process 60, reference may be made to the foregoing, and details are not described herein.

Further, the touch sensing system 20 of the above embodiment can be expanded to achieve a computer system by appropriately matching a touch sensing device and a host. Please refer to FIG. 7. FIG. 7 is a functional block diagram of a computer system 70 according to an embodiment of the present invention. As shown in FIG. 7, the computer system 70 is mainly composed of the touch sensing system 20 and a host 704 in FIG. The touch sensing device 200 can sense an object to be measured (such as a finger, a pen, etc.) and generate a detection signal representing a position of the object to be tested on a detecting panel (not shown). The touch sensing control chip 202 can determine the zoom gesture ZG represented by the two touch points by using the zoom gesture determination method to change the position difference between the two touch points on the touch sensing device 200. Finally, the touch sensitive control wafer 202 can transmit a packet Pac representing the zoom gesture ZG to the host 704. Preferably, the packet Pac may include a zoom ID code and a zoom direction code to indicate that the zoom gesture occurs on the host 704, and the zoom gesture The direction is zoom-in or zoom-out. However, the format of the packet Pac is not limited thereto, and those skilled in the art can modify or change it according to the knowledge.

It should be noted that the above embodiment uses the change of the position difference between the two touch points to determine the multi-touch gesture, and the general knowledge in the field can be relied upon. Make modifications or changes. For example, the determining unit 208 and the determining unit 210 may further determine that the gesture represented by the two touch points is a rotation gesture according to the change of the position difference between the two touch points. For example, in FIG. 3, if the position difference D between T1 and the second touch point T2 is constant, and the vertical position difference ΔY is decreased, it can be judged that T1 and T2 represent a counterclockwise (counter -clockwise) Rotate the gesture.

In summary, the zoom gesture judging method of the present invention determines the zoom gesture represented by the two touch points by detecting the change of the position difference between the two touch points, so that it can be matched with self-capacitance. Or two sensing methods such as mutual-capacitance, which improve the problem that the touch sensing device using the self-capacitance sensing method is limited by the innate physical characteristics and is misjudged.

The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the present invention should be within the scope of the present invention.

10. . . Projected capacitance sensing device

20. . . Touch sensing system

70. . . computer system

200‧‧‧ touch sensing device

202‧‧‧Touch sensor control chip

206‧‧‧Detection unit

208‧‧‧judging unit

210‧‧‧Decision unit

704‧‧‧Host

CX1~CXm, CYI~CYn‧‧‧ detection signals

T1, T2, T1', T2'‧‧‧ touch points

D‧‧‧ position difference

△X‧‧‧ horizontal position difference

△Y‧‧‧Vertical position difference

ZG‧‧‧ zoom gesture

X1~Xm, Y1~Yn‧‧‧Inductance Capacitor Series

Pac‧‧‧Package

FIG. 1 is a schematic diagram of a conventional projection capacitance sensing device.

FIG. 2 is a block diagram of a touch sensing system according to an embodiment.

FIG. 3 is a schematic diagram showing the position difference between the two touch points detected by the touch sensing control chip in FIG. 2 .

4A and 4B are schematic diagrams of a misjudgment situation when the touch sensing chip of FIG. 2 is combined with a self-capacitance sensing touch sensing device.

FIG. 5 is a flow chart of a zoom gesture determination according to an embodiment.

Figure 6 is a flow chart of a bounce mechanism according to an embodiment.

Figure 7 is a block diagram of a computer system in accordance with an embodiment.

20. . . Touch sensing system

200. . . Touch sensing device

202. . . Touch sensing control chip

206. . . Detection unit

208. . . Judging unit

210. . . Decision unit

CX1～CXm, CY1～CYn. . . Detection signal

T1, T2. . . Touch point

D. . . Position difference

ZG. . . Zoom gesture

Claims (8)

A method for determining a zoom gesture for a touch sensing device includes: detecting a first touch point and a second touch point; determining between the first touch point and a second touch point a position difference; and determining, according to the change in the position difference, a zoom gesture represented by the first touch point and the second touch point; wherein determining the first touch point and the second touch The step of determining a position difference between the control points includes: determining a horizontal position difference and a vertical position difference between the first touch point and the second touch point; wherein, when the horizontal position difference is When the value or the vertical position difference is zero, a de-bounce mechanism is used to determine whether the first touch point and the second touch point are horizontally or vertically arranged. The method for determining a zoom gesture according to claim 1, wherein the step of determining the zoom gesture represented by the first touch point and the second touch point according to the change of the position difference includes: when the position difference is When the display is continuously incremented or decremented, it is determined that the zoom gesture represented by the first touch point and the second touch point is a zoom-in or a zoom-out gesture. The zoom gesture judging method of claim 1, wherein the bounce jump mechanism is used to determine The step of whether the first touch point and the second touch point are horizontally or vertically arranged includes: continuously detecting the first touch point and the second touch point; counting the first touch point and The horizontal position difference or the vertical position difference between the second touch points is zero to generate an accumulated value; and comparing the accumulated value with a critical value, if the accumulated value is greater than the critical value And determining that the first touch point and the second touch point are horizontally or vertically arranged. The method for judging the zoom gesture of claim 3, further comprising: when the horizontal position difference and the vertical position difference are not zero, the accumulated value is zeroed. A touch sensing device for a touch sensing device includes: a detecting unit for detecting a first touch point and a second touch point; and a determining unit for determining the first a position difference between a touch point and a second touch point; and a determining unit configured to determine, according to the change in the position difference, the first touch point and the second touch point a zooming gesture; wherein the determining unit determines a horizontal position difference and a vertical position difference between the first touch point and the second touch point to determine the first touch point and the first The position difference between the two touch points. When the horizontal position difference or the vertical position difference is zero, the determining unit further determines a first touch point by using a bounce (De-bounce) mechanism. And the second touch point is No is horizontal or vertical. The touch sensing control chip of claim 5, wherein the determining unit determines that the zoom gesture represented by the first touch point and the second touch point is enlarged when the position difference value is continuously incremented or decremented (Zoom-in) or a zoom-out gesture. The touch sensing control chip of claim 5, wherein the determining unit continuously detects the first touch point and the second touch point, and counts between the first touch point and the second touch point The horizontal position difference or the vertical position difference is zero to generate an accumulated value, and compare the accumulated value with a critical value. If the accumulated value is greater than the critical value, the first touch point is determined. And the second touch point is arranged horizontally or vertically. The touch sensing control chip of claim 7, wherein the determining unit resets the accumulated value to zero when the horizontal position difference and the vertical position difference are not zero.