CN100419657C - Multi-object detection method of capacitive touchpad - Google Patents

Abstract

The invention relates to a multi-object detection method of a capacitive touch pad, which distinguishes noise interference or operation of an object on the touch pad by at least one preset time so as to correctly judge whether the object touches or leaves the touch pad and further accurately detect various operations of different gestures.

Description

Translated fromChinese

电容式触控板的多物件检测方法Multi-object detection method for capacitive touch panel

技术领域technical field

本发明有关一种电容式触控板的检测方法，特别是关于一种抗噪音的多物件检测方法。The invention relates to a detection method of a capacitive touch panel, in particular to a noise-resistant multi-object detection method.

背景技术Background technique

电容式触控板是一种可供手指在平滑的面板上滑动以控制游标移动的输入装置。因为电容式触控板的厚度非常薄，所以能够设计于超薄的笔记型电脑、键盘、数字播放器或其他装置之中，而且由于其不是机械式的设计，所以在维护上非常简便。A capacitive touchpad is an input device that allows a finger to slide across a smooth surface to control cursor movement. Because the thickness of the capacitive touch panel is very thin, it can be designed in ultra-thin notebook computers, keyboards, digital players or other devices, and because it is not a mechanical design, it is very easy to maintain.

图1为现有的二维电容式触控板100，其包括面板102、Y轴感应层104、绝缘层106、X轴感应层108及底板110。当手指112触碰面板102时，其所触碰位置的感应量(电容量)将产生改变，而连接触控板100的控制电路可将触控板上的电容量转换为感应量，如图2所示，以判断手指的位置、位移量及移动的方向。在现有技术中，要确认物件是否触碰电容式触控板100是以所检测到的感应量大小作为判断的依据，如图3所示，当感应量大于临界值th时，表示物件触碰触控板100，反之，当感应量小于临界值th时，表示物件离开触控板100或是触控板100上没有物件存在。FIG. 1 shows a conventional two-dimensionalcapacitive touch panel 100 , which includes apanel 102 , a Y-axis sensing layer 104 , aninsulating layer 106 , anX-axis sensing layer 108 and abottom plate 110 . When thefinger 112 touches thepanel 102, the sensing value (capacitance) of the touched position will change, and the control circuit connected to thetouch panel 100 can convert the capacitance on the touch panel into sensing value, as shown in the figure 2, to determine the position, displacement and direction of movement of the finger. In the prior art, it is determined whether the object touches thecapacitive touch panel 100 based on the detected sensing value. As shown in FIG. 3 , when the sensing value is greater than the critical value th, it means the object touch Touch thetouchpad 100 , otherwise, when the sensing value is less than the threshold value th, it means that the object leaves thetouchpad 100 or there is no object on thetouchpad 100 .

然而，触控板100可能受到如手机等无线装置信号的干扰而产生噪音，使触控板100误判有物件在其上进行触碰、点击、移动或其他的手势操作。图4A是在触控板100上所产生的噪音示例，该噪音经模拟数字转换(ADC)得到感应量，如图4B所示，最后再经取样得到图4C的波形，这样的波形类似两只手指触碰触控板100时所产生的波形，如图5所示，因此图4A的噪音可能被误判为两只手指触碰触控板100，造成错误的操作。However, thetouchpad 100 may be interfered by signals from wireless devices such as mobile phones to generate noise, which makes thetouchpad 100 misjudge that there is an object on which touches, clicks, moves or other gestures are performed. Fig. 4A is an example of the noise generated on thetouch panel 100. The noise is converted by analog-to-digital conversion (ADC) to obtain the induction value, as shown in Fig. 4B, and finally the waveform in Fig. 4C is obtained by sampling, such a waveform is similar to two The waveform generated when a finger touches thetouchpad 100 is shown in FIG. 5 , so the noise in FIG. 4A may be misjudged as two fingers touching thetouchpad 100 , resulting in an erroneous operation.

因此，一种能防止噪音干扰的检测方法，乃为所冀。Therefore, a detection method that can prevent noise interference is desired.

发明内容Contents of the invention

本发明的目的在于，提供一种电容式触控板的多物件检测方法，其可避免噪音的干扰。The object of the present invention is to provide a multi-object detection method for a capacitive touch panel, which can avoid noise interference.

根据本发明，一种电容式触控板的多物件检测方法是由设定至少一预设时间来辨别触控板上的感应量变化是噪音还是物件在触控板上操作，以正确判断物件触碰或离开该触控板，进而准确地检测各种不同手势的操作。According to the present invention, a multi-object detection method of a capacitive touch panel is to set at least a preset time to distinguish whether the change of the sensing amount on the touch panel is noise or whether the object is operating on the touch panel, so as to correctly judge the object Touch or leave the trackpad to accurately detect the operation of various gestures.

本发明是采用以下技术方案实现：The present invention is to adopt following technical scheme to realize:

一种电容式触控板的多物件检测方法，包括：检测该触控板的感应量，至少得到一第一峰值以及一第二峰值以及在该第一及第二峰值均大于一临界值时，计算该感应量的变化量；其中，若该感应量在一预设时间内维持增加的趋势，表示有至少二物件触碰该触控板。A multi-object detection method for a capacitive touch panel, comprising: detecting the sensing value of the touch panel, obtaining at least a first peak value and a second peak value, and when the first and second peak values are greater than a critical value , calculating the variation of the sensed amount; wherein, if the sensed amount maintains an increasing trend within a preset time, it means that at least two objects touch the touch panel.

一种电容式触控板的多物件检测方法，包括：在确认至少二物件触碰该触控板后，检测该触控板的感应量，至少得到一第一峰值以及一第二峰值；以及在该第一及第二峰值中至少一个小于一临界值时，计算该感应量的变化量；其中，若小于该临界值的该第一或第二峰值在一预设时间内维持减少的趋势，表示该至少二物件中至少一个离开该触控板。A multi-object detection method for a capacitive touch panel, comprising: after confirming that at least two objects touch the touch panel, detecting the sensing value of the touch panel to obtain at least a first peak value and a second peak value; and When at least one of the first and second peak values is less than a critical value, calculate the variation of the sensing quantity; wherein, if the first or second peak value less than the critical value maintains a decreasing trend within a preset time , indicating that at least one of the at least two objects leaves the touch panel.

一种电容式触控板的多物件检测方法，包括：确认至少二物件触碰该触控板；计算触碰该触控板的物件数目；计算该至少二物件触碰该触控板的触碰时间；若该触碰时间小于一第一预设时间，则确认所有物件离开该触控板；计算所有的该物件离开该触控板的离开时间；以及若该离开时间大于一第二预设时间，则送出一单击信号；其中，在计算该触碰时间时，在该触控板上的物件数目维持不变。A multi-object detection method of a capacitive touch panel, comprising: confirming that at least two objects touch the touch panel; counting the number of objects touching the touch panel; calculating the number of touches of the at least two objects touching the touch panel touch time; if the touch time is less than a first preset time, confirm that all objects leave the touchpad; calculate the departure time of all the objects from the touchpad; and if the departure time is greater than a second preset time When the time is set, a click signal is sent; wherein, when calculating the touch time, the number of objects on the touch panel remains unchanged.

一种电容式触控板的多物件检测方法，包括：确认至少二物件触碰该触控板；计算触碰该触控板的物件数目；计算该至少二物件触碰该触控板的第一触碰时间；若在该第一触碰时间小于一第一预设时间，则确认该至少二物件离开该触控板；计算该至少二物件离开该触控板的离开时间；若该离开时间小于一第二预设时间，则确认该至少二触碰该触控板；计算该至少二物件触碰该触控板的第二触碰时间；若该第二触碰时间小于一第三预设时间，则确认该至少二物件离开该触控板；以及送出一双击信号；A multi-object detection method of a capacitive touch panel, comprising: confirming that at least two objects touch the touch panel; counting the number of objects touching the touch panel; calculating the number of the at least two objects touching the touch panel A touch time; if the first touch time is less than a first preset time, then confirm that the at least two objects leave the touch panel; calculate the departure time for the at least two objects to leave the touch panel; if the leave If the time is less than a second preset time, then confirm that the at least two people touch the touch panel; calculate the second touch time when the at least two objects touch the touch panel; if the second touch time is less than a third confirming that the at least two objects leave the touch panel at a preset time; and sending a double-click signal;

其中，在计算该第一及第二触碰时间时，触碰该触控板的物件数目维持不变。Wherein, when calculating the first and second touch times, the number of objects touching the touch panel remains unchanged.

一种电容式触控板的多物件检测方法，包括：A multi-object detection method for a capacitive touch panel, comprising:

确认至少二物件触碰该触控板；计算触碰该触控板的物件数目；计算该至少二物件触碰该触控板的触碰时间；在该第一触碰时间大于一预设时间时，确认该至少二物件中至少一个离开该触控板；计算留在该触控板上的物件数目；以及送出一拖曳信号；其中，在计算该触碰时间时，在该触控板上的物件数目维持不变，而在至少一物件离开该触控板后，留在该触控板上的物件数目必须大于1。Confirming that at least two objects touch the touchpad; counting the number of objects touching the touchpad; calculating the touch time of the at least two objects touching the touchpad; when the first touch time is greater than a preset time , confirm that at least one of the at least two objects leaves the touch panel; calculate the number of objects left on the touch panel; and send a dragging signal; wherein, when calculating the touch time, on the touch panel The number of objects remains constant, and the number of objects remaining on the touchpad must be greater than 1 after at least one object leaves the touchpad.

附图说明Description of drawings

图1为现有的二维电容式触控板；Fig. 1 is an existing two-dimensional capacitive touch panel;

图2为图1的触控板上感应量与位置的关系图；Fig. 2 is a diagram showing the relationship between the sensing amount and the position on the touch panel of Fig. 1;

图3显示两只手指触碰触控板后所检测到的感应量变化；Fig. 3 shows the change of sensing quantity detected after two fingers touch the touchpad;

图4A显示一噪音；Figure 4A shows a noise;

图4B为图4A中噪音经类比数位转换所得到的感应量；Fig. 4B is the induction quantity obtained by analog-to-digital conversion of the noise in Fig. 4A;

图4C为将图4B取样后的波形图；Figure 4C is a waveform diagram after sampling Figure 4B;

图5为两只手指触碰触控板时所检测到的波形图；Figure 5 is a waveform diagram detected when two fingers touch the touch panel;

图6为感应量大于临界值th后所检测到的感应量变化；Fig. 6 is the change of the sensing amount detected after the sensing amount is greater than the critical value th;

图7为图6中两次感应量的差值；Fig. 7 is the difference value of two sensing quantities in Fig. 6;

图8显示一检测信号用以说明本发明；Figure 8 shows a detection signal to illustrate the present invention;

图9显示一检测信号及触碰信号；FIG. 9 shows a detection signal and a touch signal;

图10为感应量小于临界值th后所检测到的感应量变化；Fig. 10 is the change of the sensed amount detected after the sensed amount is less than the critical value th;

图11为图10中两次感应量的差值；Fig. 11 is the difference value of two sensing quantities in Fig. 10;

图12显示一检测信号；Figure 12 shows a detection signal;

图13显示一检测信号及离开信号；Figure 13 shows a detection signal and an exit signal;

图14显示一检测信号及一单击信号；Figure 14 shows a detection signal and a click signal;

图15显示一检测信号及一双击信号；以及Figure 15 shows a detection signal and a double-click signal; and

图16显示一检测信号及一拖曳信号。FIG. 16 shows a detection signal and a drag signal.

符号说明Symbol Description

100电容式触控板                    102面板100capacitive touch panel 102 panels

104Y轴感应层                       106绝缘层104 Y-axis induction layer 106 Insulation layer

108X轴感应层                       110底板108X-axis induction layer 110 bottom plate

112手指                            200这次所检测到的感应量曲线112 fingers 200 The sensing curve detected this time

202前一次所检测到的感应量曲线202 The induction curve detected last time

204检测信号                        206检测信号204detection signal 206 detection signal

208触碰信号                        210这次所检测到的感应量曲线208Touch signal 210 Sensitivity curve detected this time

212前一次所检测到的感应量曲线212 Inductance curve detected last time

214检测信号                        216检测信号214detection signal 216 detection signal

218离开信号                        220检测信号218departure signal 220 detection signal

222单击信号                        224检测信号222click signal 224 detection signal

226双击信号                        228检测信号226 double-click signal 228 detection signal

230拖曳信号230 Towing Signal

具体实施方式Detailed ways

本发明的检测方法不需要依靠硬体检测电路的改善，就可以提高噪音的抵抗能力，并且能区别多种手势。The detection method of the present invention can improve the noise resistance and distinguish various gestures without relying on the improvement of the hardware detection circuit.

确认多物件触碰的检测方法Confirm the detection method of multi-object touch

图6为感应量的两个峰值均大于临界值th后所检测到的感应量变化，其中曲线200是这次所检测到的感应量，曲线202是前一次所检测到的感应量。图7是图6中两次感应量的差值。图8显示一检测信号204。参照图6、7及8，在检测触控板上的感应量时，当所检测到的感应量的两个峰值均大于临界值th，如图6所示，检测信号204由低电位转为高电位，如图8所示，接着在时间T_DownDetect内持续检测该触控板上的感应量，并将每一次所检测到的感应量200减去前一次的感测量202，得到一感应量差值dV，如图7所示，若在时间T_DownDetect内，所得到的感应量差dV均为正值，表示有二物件触碰触控板。其中感应量的每一个峰值是对应一物件，因此在其他实施例中，如果有两个以上的物件触碰该触控板时，该感应量将对应出现两个以上的峰值。FIG. 6 shows the change of the sensed amount detected after the two peak values of the sensed amount are greater than the critical value th, wherein the curve 200 is the sensed amount detected this time, and the curve 202 is the sensed amount detected last time. Figure 7 is the difference between the two sensing values in Figure 6. FIG. 8 shows adetection signal 204 . Referring to Figures 6, 7 and 8, when detecting the inductance on the touch panel, when the two peak values of the detected inductance are greater than the critical value th, as shown in Figure 6, thedetection signal 204 changes from low potential to high Potential, as shown in Figure 8, then continuously detect the sensing amount on the touch panel within the time T_DownDetect , and subtract the sensing amount 202 of the previous sensing amount from the sensing amount 200 detected each time to obtain a sensing amount difference The value dV is as shown in FIG. 7 . If the obtained sensing difference dV is positive within the time T_DownDetect , it means that two objects touch the touch panel. Each peak of the sensing value corresponds to an object, so in other embodiments, if more than two objects touch the touch panel, the sensing value will correspond to more than two peaks.

确认多物件触碰手势(Touch Gesture)的检测方法Confirm the detection method of multi-object touch gesture (Touch Gesture)

图9显示一检测信号206及触碰信号208。在检测到至少二物件触碰触控板时，开始计算该至少二物件在触控板上的停留时间，在符合前述「确认多物件触碰的检测方法」确定物件触碰触控板后，计算触碰该触控板的物件数目，若该至少二物件连续停留在触控板上的时间大于预设时间T_Touch，送出多物件触碰信号208，并计算该至少二物件的位置送出一位置信号。其中该多物件触碰信号208可以包括物件数目的资讯。FIG. 9 shows adetection signal 206 and atouch signal 208 . When it is detected that at least two objects touch the touchpad, start to calculate the residence time of the at least two objects on the touchpad, and after confirming that the object touches the touchpad according to the aforementioned "detection method for confirming multi-object touch", Calculate the number of objects touching the touch panel, if the at least two objects stay on the touch panel continuously for longer than the preset time T_Touch , send amulti-object touch signal 208, and calculate the positions of the at least two objects and send a location signal. Themulti-object touch signal 208 may include information about the number of objects.

确认多物件离开的检测方法Confirm the detection method of multiple objects leaving

图10是感应量的两个峰值均小于临界值th后所检测到的感应量变化，其中曲线210是这次所检测到的感应量，曲线212是前一次所检测到的感应量。图11系图10中两次感应量的差值，图12显示一检测信号214。参照图10、11及12，在物件触碰触控板后，一旦检测到感应量的两个峰值至少一个小于临界值th，在此实施例中感应量的两个峰值均小于临界值，如图10所示，检测信号214由高电位转为低电位，如图12所示，接着在时间T_LiftDetect内持续检测该感应量，并将每一次所检测到的感应量210减去前一次的感测量212，得到一感应量差值dV，如图11所示，若在时间T_LiftDetect内，所得到的感应量差dV均为负值，表示该二物件中至少一个离开触控板。FIG. 10 shows the change of the detected sensing amount after the two peak values of the sensing amount are both smaller than the critical value th, wherein thecurve 210 is the sensing amount detected this time, and thecurve 212 is the sensing amount detected last time. FIG. 11 shows the difference between the two sensing values in FIG. 10 , and FIG. 12 shows adetection signal 214 . 10, 11 and 12, after the object touches the touch panel, once it is detected that at least one of the two peak values of the sensing value is less than the threshold value th, in this embodiment the two peak values of the sensing value are both smaller than the threshold value, such as As shown in Figure 10, thedetection signal 214 changes from a high potential to a low potential, as shown in Figure 12, and then continuously detects the sensing quantity within the time T_LiftDetect , and subtracts the previous sensing quantity from thesensing quantity 210 detected each time Thesensing value 212 is to obtain a sensing value difference dV, as shown in FIG. 11 , if the obtained sensing value difference dV is negative within the time T_LiftDetect , it means that at least one of the two objects has left the touch panel.

确认多物件离开手势(Lift Gesture)的检测方法Confirm the detection method of multi-object lift gesture (Lift Gesture)

图13显示一检测信号216及离开信号218。在物件触碰触控板后，一旦检测到至少一物件离开触控板时，开始计算该至少一物件离开触控板的时间，计算留在该触控板上的物件数目，若仍有物件留在触控板上，计算其位置送出一位置信号，在符合前述「确认多物件离开的检测方法」且物件离开触控板的时间大于预设时间T_LiftGesture。时，送出离开信号218。同样地，该离开信号208可以包括物件数目的资讯。FIG. 13 shows adetection signal 216 and anexit signal 218 . After the object touches the touchpad, once it is detected that at least one object leaves the touchpad, start to count the time when the at least one object leaves the touchpad, calculate the number of objects left on the touchpad, if there are still objects Stay on the touchpad, calculate its position and send a position signal, when the above-mentioned "detection method for confirming the departure of multiple objects" is met and the time for the object to leave the touchpad is greater than the preset time T_LiftGesture . , send outsignal 218. Likewise, theexit signal 208 may include object number information.

多物件单击手势(Tap Gesture)的检测方法Multi-object click gesture (Tap Gesture) detection method

图14显示一检测信号220及一单击信号222。在检测到至少二物件触碰触控板时，检测信号220由低电位转为高电位，如图14所示，跟着计算该物件触碰该触控板的触碰时间以及计算物件数目，在确定符合「确认多物件触碰的检测方法」，并且在该触碰时间小于一预设时间T_TapDown便检测到所有物件离开该触控板，则检测信号220由高电位转为低电位，跟着计算该物件离开该触控板的离开时间，在确定符合「确认多物件离开的检测方法」，且该离开时间大于预设时间T_TapLift时，送出一单击信号222，同时计算该至少二物件单击的位置，送出一位置信号。FIG. 14 shows adetection signal 220 and aclick signal 222 . When at least two objects are detected to touch the touch panel, thedetection signal 220 is changed from a low potential to a high potential, as shown in FIG. It is determined that the "detection method for confirming multi-object touch" is met, and all objects are detected to leave the touchpad when the touch time is less than a preset time T_TapDown , then thedetection signal 220 is changed from a high potential to a low potential, and then Calculate the departure time of the object leaving the touch panel, and when it is determined that it meets the "detection method for confirming the departure of multiple objects", and the departure time is greater than the preset time T_TapLift , send aclick signal 222, and calculate the at least two objects at the same time The clicked position sends a position signal.

多物件双击手势(Double Tap)的检测方法Method for detecting double-tap gestures of multiple objects

图15显示一检测信号224及一拖曳信号226。在检测到至少二物件第一次触碰触控板时，检测信号224由低电位转为高电位，如图15所示，跟着计算该物件触碰该触控板的第一触碰时间以及计算物件数目，在确定符合「确认多物件触碰的检测方法」，并且在物件数目不变的情况下，该第一触碰时间小于预设时间T_TapDownn便检测到所有的物件离开该触控板，检测信号224由高电位转为低电位，跟着计算该至少二物件离开该触控板的离开时间，在确定符合「确认多物件离开的检测方法」，且在该离开时间小于预设时间T_apLift又检测到所有的物件第二次触碰该触控板，则检测信号224再次由低电位转为高电位，计算第二次触碰该触控板的第二触碰时间，在确定符合「确认多物件触碰的检测方法」，并且在物件数目不变的情况下，该第二触碰时间小于预设时间T_DoubleDown时，检测到所有的物件再次离开该触控板，则检测信号224由高电位转为低电位，在确定符合「确认多物件离开的检测方法」，送出一双击信号226，同时计算该至少二物件的位置，送出一位置信号。FIG. 15 shows adetection signal 224 and adrag signal 226 . When at least two objects are detected to touch the touch panel for the first time, thedetection signal 224 is changed from a low potential to a high potential, as shown in FIG. Calculate the number of objects, and when it is confirmed that it conforms to the "detection method for confirming multi-object touch" and the number of objects remains unchanged, the first touch time is less than the preset time T_TapDownn , and all objects are detected to leave the touch board, thedetection signal 224 changes from a high potential to a low potential, and then calculates the departure time of the at least two objects from the touch panel, and confirms that the "detection method for confirming the departure of multiple objects" is met, and the departure time is less than the preset time_TapLift detects that all objects touch the touchpad for the second time, then thedetection signal 224 changes from low potential to high potential again, and calculates the second touch time of touching the touchpad for the second time. Conforms to the "detection method for confirming multi-object touch", and under the condition that the number of objects remains unchanged, when the second touch time is less than the preset time T_DoubleDown , if all objects are detected to leave the touchpad again, then the detection Thesignal 224 changes from a high potential to a low potential. When it is determined that the "detection method for confirming the departure of multiple objects" is met, a double-click signal 226 is sent, and the positions of the at least two objects are calculated at the same time, and a position signal is sent.

多物件拖曳手势(Drag Ges ture)的检测方法Multi-object drag gesture (Drag Gesture) detection method

图16显示一检测信号228及一拖曳信号230。检测到至少二物件第一次触碰触控板时，检测信号228由低电位转为高电位，如图16所示，跟着计算该至少二物件触碰该触控板的第一触碰时间以及计算物件数目，其中物件数目必须大于等于2，在确定符合「确认多物件触碰的检测方法」，并且在物件数目不变的情况下，该第一触碰时间大于预设时间T_TapDown时，检测到该至少二物件中至少一个离开该触控板，检测信号228由高电位转为低电位，在确定离开的物件符合「确认多物件离开的检测方法」，并且留在触控板上的物件数目大于1时，送出一拖曳信号230，同时计算该物件的位置，送出一位置信号。FIG. 16 shows a detection signal 228 and a drag signal 230 . When at least two objects are detected to touch the touch panel for the first time, the detection signal 228 is changed from a low potential to a high potential, as shown in FIG. 16 , and then the first touch time of the at least two objects touching the touch panel is calculated. And calculate the number of objects, where the number of objects must be greater than or equal to 2, when it is determined that the "detection method for confirming multi-object touch" is met, and when the number of objects remains unchanged, the first touch time is greater than the preset time T_TapDown , it is detected that at least one of the at least two objects leaves the touch panel, the detection signal 228 changes from a high potential to a low potential, and when it is determined that the departed object meets the "detection method for confirming the departure of multiple objects", and stays on the touch panel When the number of objects is greater than 1, a dragging signal 230 is sent, and the position of the object is calculated at the same time, and a position signal is sent.

在上述的各个实施例中，利用感应量的变化以及预设的时间比较，即可确认各种在触控板上的操作，避免受噪音干扰而误判。In each of the above-mentioned embodiments, various operations on the touch panel can be confirmed by using the change of the sensing value and the preset time comparison, so as to avoid misjudgment caused by noise interference.

Claims (5)

1. the multi-object detection method of a capacitive touch control plate comprises:

Detect the induction amount of this Trackpad, obtain one first peak value and one second peak value at least; And

During all greater than a critical value, calculate the variable quantity of this induction amount and preceding once detected induction amount at this first and second peak value;

Wherein, if this induction amount is kept the trend of increase in a Preset Time, expression has at least two objects to touch this Trackpad.

2. the method for claim 1 is characterized in that, more comprises:

Calculate the object number of this Trackpad of touching;

When the object number on this Trackpad remains unchanged, calculate the touching time that this at least two object is touched this Trackpad; And

When this touching time reaches one second Preset Time, send a touching signal.

3. method as claimed in claim 2 is characterized in that, after sending described touching signal, also comprises the position of calculating this at least two object, sends a position signalling.

4. the multi-object detection method of a capacitive touch control plate comprises:

After at least two objects are touched this Trackpad, detect the induction amount of this Trackpad, obtain one first peak value and one second peak value at least; And

When at least one is less than a critical value in this first and second peak value, calculate the variable quantity of this induction amount;

Wherein, as if the trend of in a Preset Time, keeping minimizing less than this first or second peak value of this critical value, represent that at least one leaves this Trackpad in this at least two object.

5. method as claimed in claim 4 is characterized in that, more comprises:

Calculate the time departure that this at least one object leaves this Trackpad;

When this time departure surpasses one second Preset Time, send one and leave signal; And

The object number on this Trackpad is stayed in calculating;

Wherein,, calculate the position of staying object on this Trackpad, send a position signalling if stay object number on this Trackpad when non-vanishing.

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