1. Field of the Invention
The present invention relates to a click gesture determination method, and more particularly, to a click gesture determination method, a touch control chip, a touch control system and a computer system utilizing the touch control chip capable of simply and flexibly determining a single click gesture.
2. Description of the Prior Art
Generally, touch sensing devices such as capacitive, resistive and other types of touch sensing devices, are capable of generating detecting signals related to a user's touch event in a touch sensing chip; the chip then compares the signal values of the detecting signals with threshold values, and determines, according to a result of the comparison, a touch point, and in turn, a gesture. In an example of capacitive touch sensing devices, touch events are determined by detecting the capacitance difference generated when the human body touches a touch point on the touch panel; in other words, capacitive touch sensing can be realized through determining a touch point, and in turn, a touch event, by detecting the variations in capacitance characteristics when the human body touches the touch point.
Specifically, please refer to FIG. 1, which illustrates a conventional projected capacitive touch sensing device 10. The projected capacitive touch sensing device 10 includes sensing capacitor strings X1-Xm, Y1-Yn. Each of the sensing capacitor strings X1-Xm, Y1-Yn is a one-dimensional structure formed by a plurality of sensing capacitors connected in series. Conventional touch sensing methods resort to detecting the capacitance of each of the sensing capacitor strings to determine whether a touch event occurs. The sensing capacitor strings X1-Xm and Y1-Yn are utilized to determine vertical and horizontal touch events, respectively. In the case of horizontal operations, assume the sensing capacitor string X1 has Q sensing capacitors each with a capacitance of C, then under normal circumstances, the sensing capacitor string X1 has a capacitance of QC; and when the human body (e.g. a finger) comes in contact with a sensing capacitor of the sensing capacitor string X1, assume the difference in capacitance is ΔC. It follows that, if the capacitance of the sensing capacitor string X1 is detected to be greater than or equal to a predefined value (e.g. QC+ΔC), it can be inferred that a finger is touching a certain point on the sensing capacitor string X1. Likewise, a determination may be similarly asserted for vertical operations. As illustrated in FIG. 1, when the finger touches a touch point TP1 (i.e. coordinates (X3, Y3)), the capacitances of the sensing capacitor strings X3 and Y3 are concurrently modified, and it may therefore be determined that the touch point falls at coordinates (X3, Y3). Note that, however, the threshold capacitances of the sensing capacitor strings X1-Xm for determining vertical directions, and the threshold capacitance of the sensing capacitor strings Y1-Yn for determining horizontal directions, do not have to be the same, depending on practical requirements.
Conventionally, under the aforementioned configurations, determining a single click gesture requires concurrently satisfying both time and distance constraints for a single click gesture to be established. Specifically, please refer to FIG. 2, which illustrates a time constraint for a conventional single click gesture determination. In determining single click gestures, the time constraint requires that for a certain touch point, the time Td during which the touch occurs must be longer than a predefined time T1 and shorter than a predefined time T2, e.g. the time Td during which capacitance is greater than the threshold capacitance QC+ΔC must be longer than 150 ms and shorter than 500 ms. Constraining the time Td to be greater than the predefined time T1 precludes faulty determinations; and constraining the time Td to be shorter than the predefined time T2 means that a single click gesture must be performed within a predefined time T2. On the other hand, the distance constraint requires an entering point and a leaving point to have identical positions. The distance constraint represents that the movement of a single click gesture must be less than a certain distance. If both time and distance constraints are met, the determination for a single click gesture can be established.
However, conventional methods for determining a single click gesture impose both time and distance constraints, resulting in a determination process that is overcomplicated and inflexible for various application needs. Hence, an improvement over the prior art is necessary.