TWI502416B - Sensing apparatus for touch panel and sensing method thereof - Google Patents

觸控面板的感測裝置以及其感應方法Touch panel sensing device and sensing method thereof

本發明係有關於一種感測裝置，特別是有關於一種用於觸控面板的感測裝置及其感應方法。The present invention relates to a sensing device, and more particularly to a sensing device for a touch panel and a sensing method thereof.

藉由降低或減少機械按鈕、鍵盤以及指標裝置的需要，觸碰感應裝置允許使用者便利地介接電子系統與顯示器。舉例來說，藉由簡單地觸碰在顯示裝置上的觸控螢幕的圖像所識別的位置，使用者可實施複雜的順序指令。The touch sensing device allows the user to conveniently interface between the electronic system and the display by reducing or reducing the need for mechanical buttons, keyboards, and indicator devices. For example, the user can implement complex sequential instructions by simply touching the location identified by the image of the touch screen on the display device.

有數種型態的技術用於實施觸控感測裝置，舉例來說，包括電阻式、紅外線、電容式、表面聲波、電磁以及近場影像(near field imaging)技術等。電容式觸控感測裝置已經可在很多應用運作很好。在許多觸控感測裝置之中，當在感測器中導電物件電容地耦合到導電觸控工具，例如使用者的手指時，可感應到輸入。There are several types of techniques for implementing touch sensing devices, including, for example, resistive, infrared, capacitive, surface acoustic, electromagnetic, and near field imaging techniques. Capacitive touch sensing devices are already working well in many applications. Among many touch sensing devices, an input can be sensed when a conductive object is capacitively coupled to a conductive touch tool, such as a user's finger, in the sensor.

通常，不管何時電子導電元件互相接近而沒有實際接觸，它們的電場互動而形成電容。在電容式觸控感測裝置的案例中，當一個物件如手指，接觸觸控感測介面，微小電容形成於物件與接近物件的感應點之間。藉由偵測在每個感測點的電容的變化且指明感測點的位置，當物件移動經過觸控表面時，感測電路可辨認多個物件且決定物件的特性(例如位置、壓力、方向、速度、加速等等)。Generally, whenever the electronically conductive elements are in close proximity to one another without actual contact, their electric fields interact to form a capacitance. In the case of a capacitive touch sensing device, when an object such as a finger touches the touch sensing interface, a minute capacitance is formed between the object and the sensing point of the object. By detecting the change in capacitance at each sensing point and indicating the location of the sensing point, the sensing circuit can identify the plurality of objects and determine the characteristics of the object (eg, position, pressure, when the object moves past the touch surface). Direction, speed, acceleration, etc.).

然而，當在同一時間兩手指接觸觸控感測表面時，電容式觸控感測裝置可能不能精確地偵測在接觸瞬間的兩個感測點。相反地，可以偵測到四個感應點(兩個所謂的鬼點)，如第1a圖所示。第一感測電路110與第二感測電路120分別感應沿著觸控表面的兩個不同的軸的兩個感應點的電容變化。因此，有四個可能感測點會被電容式觸控感測裝置所感測。However, when the two fingers touch the touch sensing surface at the same time, the capacitive touch sensing device may not accurately detect the two sensing points at the moment of contact. Conversely, four sensing points (two so-called ghost points) can be detected, as shown in Figure 1a. The first sensing circuit 110 and the second sensing circuit 120 respectively sense capacitance changes of two sensing points along two different axes of the touch surface. Therefore, there are four possible sensing points that are sensed by the capacitive touch sensing device.

上述電容式觸控感測裝置也稱為自容式(self capacitor)觸控感測裝置100。顯示於第1b圖中的另一電容式觸控感測裝置稱為互容式(mutual capacitor)觸控感測裝置。互容式觸控感測裝置150有一個掃描驅動電路160、感測電路170以及類比數位轉換器180。舉例來說，掃描驅動電路160掃描沿著Y軸排列的第一電極，其中感測電路170沿著X軸感測對應掃描的第一電極的電容的變化。類比數位轉換器180轉換感測自感測電路170的感測的類比信號成為數位信號。因此，互容觸控感測裝置150可能需要更多時間感測兩個感測點，因為它總是必須花費2ms*8=16ms(有8列的電極分別沿著X軸與Y軸)去精確地掃描與感測兩個點，但是自容只要花費2ms*2=4ms掃描與感測兩個感測點。此外，互容式觸控感測裝置可能也佔據更多儲存容量(大約8*8=16=1024位元)，因為當電極被掃描與感測時，許多感測結果需要被儲存。The capacitive touch sensing device is also referred to as a self-capacitance touch sensing device 100. Another capacitive touch sensing device shown in FIG. 1b is called a mutual capacitive touch sensing device. The mutual capacitive touch sensing device 150 has a scan driving circuit 160, a sensing circuit 170, and an analog digital converter 180. For example, the scan driving circuit 160 scans the first electrodes arranged along the Y axis, wherein the sensing circuit 170 senses a change in capacitance of the corresponding first electrode of the scan along the X axis. The analog to digital converter 180 converts the sensed analog signal sensed from the sense circuit 170 into a digital signal. Therefore, the mutual-capacitive touch sensing device 150 may need more time to sense two sensing points because it always takes 2ms*8=16ms (the electrodes of 8 columns are respectively along the X-axis and the Y-axis) Accurately scan and sense two points, but self-contained as long as it takes 2ms*2=4ms to scan and sense two sensing points. In addition, the mutual capacitive touch sensing device may also occupy more storage capacity (about 8*8=16=1024 bits) because many sensing results need to be stored when the electrodes are scanned and sensed.

因此，有必要提供一種可用較少時間與較少儲存空間精確降低鬼點且偵測實際兩個觸碰點的感測裝置。Therefore, it is necessary to provide a sensing device that can reduce ghost points with less time and less storage space and detect actual two touch points.

本揭露提供一種觸控面板的感測裝置，適用於當以二個物件觸碰觸控面板時感應二觸碰點，包括：複數個第一電極，係沿著一第一軸形成；複數個第二電極，係沿著一第二軸形成；複數個感測電容，係形成於該第一電極與該第二電極的交叉點，其中當該觸控面板以物件觸碰時，該感測電容的電容值改變；一第一感測電路，藉由感測對應於該第一電極的二位置的該感測電容之變化的電容值定位二物件所觸碰的該第一電極的該二位置；一第二感測電路，藉由感應對應於該第二電極的二位置的該感測電容之變化的電容值定位二物件所觸碰的該第二電極的該二位置，且與該第一感測電路同步致動；一掃描驅動電路，用以順序掃描該第一電極與該第二電極的其中一個；以及一第三感測電路，藉由感測對應於該掃描的電極的二位置的該感測電容之變化的電容值定位二物件所觸碰的該掃描電極的該二位置；其中根據該第一電極的該二位置、該第二電極的該二位置以及該掃描電極的該二位置決定該二觸碰點。The present disclosure provides a sensing device for a touch panel, which is adapted to sense two touch points when two objects touch the touch panel, including: a plurality of first electrodes formed along a first axis; The second electrode is formed along a second axis; a plurality of sensing capacitors are formed at an intersection of the first electrode and the second electrode, wherein the sensing is performed when the touch panel is touched by the object The capacitance value of the capacitor is changed; a first sensing circuit positions the second electrode of the first electrode touched by the two objects by sensing a capacitance value corresponding to the change of the sensing capacitance of the two positions of the first electrode a second sensing circuit, the two positions of the second electrode touched by the two objects are located by sensing a capacitance value corresponding to the change of the sensing capacitance corresponding to the two positions of the second electrode, and a first sensing circuit is synchronously actuated; a scan driving circuit for sequentially scanning one of the first electrode and the second electrode; and a third sensing circuit for sensing an electrode corresponding to the scan The capacitance value of the change of the sensing capacitance at the two positions The two-bit position of the scanning electrodes two touched by the object; wherein the second position in accordance with the first electrode, and the position of the two electrodes of the second scanning electrode determined by the position of the two touch points.

本揭露另提供一種觸控面板的感測方法，適用於當該觸控面板以二物件觸碰時感測二觸控點，其中複數個感測電容形成於複數個第一電極與第二電極的交叉點，且當以物件觸碰面板時，該感測電容的電容值變化，包括：藉由一第一感測電路感測對應於該第一電極的二位置的該感測電容之變化的電容值定位二物件所觸碰的該第一電極的該二位置；藉由一第二感測電路感測對應於該第二電極的二位置的該感測電容之變化的電容值定位二物件所觸碰的該第二電極的該二位置；藉由一掃描驅動電路順序掃描該第一電極與該第二電極的其中一個；以及藉由一第三感測電路感測對應於該掃描的電極的二位置的該感測電容之變化的電容值定位二物件所觸碰的該掃描電極的該二位置；根據該第一電極的該二位置、該第二電極的該二位置以及該掃描電極的該二位置決定該二觸碰點。The present disclosure further provides a sensing method for a touch panel, which is suitable for sensing two touch points when the touch panel is touched by two objects, wherein a plurality of sensing capacitors are formed on the plurality of first electrodes and second electrodes And a change in the capacitance value of the sensing capacitor when the object touches the panel, comprising: sensing a change of the sensing capacitance corresponding to the two positions of the first electrode by a first sensing circuit The capacitance value locates the two positions of the first electrode touched by the two objects; and the capacitance value corresponding to the change of the sensing capacitance corresponding to the two positions of the second electrode is sensed by a second sensing circuit The two positions of the second electrode touched by the object; sequentially scanning one of the first electrode and the second electrode by a scan driving circuit; and sensing corresponding to the scan by a third sensing circuit The capacitance value of the change of the sensing capacitance at the two positions of the electrode positions the two positions of the scan electrode touched by the two objects; according to the two positions of the first electrode, the two positions of the second electrode, and the The two positions of the scan electrode The two touch points.

為使本發明之上述目的、特徵和優點能更明顯易懂，下文特舉較佳實施例，並配合所附圖式，作詳細說明如下：第2圖顯示發明的觸控面板的感測裝置的示意圖。感測系統200包括複數個第一電極202(例如d1-d8)、複數個第二電極204(例如p1-p8)、第一感測電路210、第二感測電路220、掃描驅動電路230以及第三掃描電路240。第三感測電路240可能是低解析度的類比數位轉換器，但不限於此。The above described objects, features and advantages of the present invention will become more apparent from the following description of the preferred embodiments of the invention. Schematic diagram. The sensing system 200 includes a plurality of first electrodes 202 (eg, d1-d8), a plurality of second electrodes 204 (eg, p1-p8), a first sensing circuit 210, a second sensing circuit 220, a scan driving circuit 230, and The third scan circuit 240. The third sensing circuit 240 may be a low-resolution analog digital converter, but is not limited thereto.

複數個第一電極202沿著第一軸形成，且複數個第二電極204沿著第二軸形成。複數個感測電容206因此形成於第一電極與第二電極的交叉點之間。當觸控面板以物件或手指觸碰時，感測電容206的電容值變化。藉由感測對應於第一電極的二位置的感測電容之變化的電容值，第一感測電路210用於定位二物件所觸碰的第一電極的二位置。藉由感測對應於第一電極的二位置的感測電容之變化的電容值，第二感測電路220用於定位二物件所觸碰的第二電極的二位置，且第一感測電路210與第二感測電路220同步致動。也就是說，第一感測電路210與第二感測電路220可能同時感測在觸控面板上的碰觸點。A plurality of first electrodes 202 are formed along the first axis, and a plurality of second electrodes 204 are formed along the second axis. A plurality of sensing capacitors 206 are thus formed between the intersections of the first electrode and the second electrode. When the touch panel is touched by an object or a finger, the capacitance value of the sensing capacitor 206 changes. The first sensing circuit 210 is configured to locate two positions of the first electrode touched by the two objects by sensing a capacitance value corresponding to a change in the sensing capacitance of the two positions of the first electrode. The second sensing circuit 220 is configured to locate two positions of the second electrode touched by the two objects by sensing a capacitance value corresponding to a change of the sensing capacitance of the two positions of the first electrode, and the first sensing circuit 210 is actuated in synchronization with the second sensing circuit 220. That is, the first sensing circuit 210 and the second sensing circuit 220 may simultaneously sense the touch contacts on the touch panel.

掃描驅動電路230用於藉由感測對應於掃描電極的二位置的感測電容之變化的電容值順序地掃描第一電極與第二電極的其中一個。第三感測電路240用於順序地定位二物件所觸碰的掃描電極的二位置。當掃描驅動電路230掃描第一電極(測試信號依序地傳送到第二電極p1-p8)，然後第三感測電路240感測第一電極(d1-d8)。第三感測電路240可能整合到第一感測電路210。相對地，當掃描驅動電路230掃描第二電極(測試信號依序地傳送到第一電極d1-d8)，則第三感測電路240感測第二電極(p1-p8)。第三感測電路240可能整合到第二感測電路220。The scan driving circuit 230 is configured to sequentially scan one of the first electrode and the second electrode by sensing a capacitance value corresponding to a change in the sensing capacitance of the two positions of the scan electrode. The third sensing circuit 240 is configured to sequentially position the two positions of the scan electrodes touched by the two objects. When the scan driving circuit 230 scans the first electrodes (the test signals are sequentially transferred to the second electrodes p1 - p8), then the third sensing circuit 240 senses the first electrodes (d1 - d8). The third sensing circuit 240 may be integrated into the first sensing circuit 210. In contrast, when the scan driving circuit 230 scans the second electrodes (the test signals are sequentially transmitted to the first electrodes d1 to d8), the third sensing circuit 240 senses the second electrodes (p1 - p8). The third sensing circuit 240 may be integrated into the second sensing circuit 220.

控制電路250用於根據第一電極的二位置、第二電極的二位置以及掃描的電極的二位置決定二碰觸點。控制電路250更用於控制第一感測電路210、第二感測電路220、掃描驅動電路230以及第三感測電路240。The control circuit 250 is configured to determine the two-touch contact according to the two positions of the first electrode, the two positions of the second electrode, and the two positions of the scanned electrodes. The control circuit 250 is further used to control the first sensing circuit 210, the second sensing circuit 220, the scan driving circuit 230, and the third sensing circuit 240.

第3圖係根據發明的實施例說明觸控面板的感測方法。觸控面板的感測方法適用於當觸控面板以二物件觸碰時感測二觸碰點。首先，在步驟310，觸控面板的第一感測電路可能藉由感測對應於第一電極的二位置的感測電容之變化的電容值定位二物件所觸碰的第一電極的二位置。接著，在步驟320，觸控面板的第二感測電路可能藉由感測對應於第二電極的二位置的感測電容之變化的電容值定位二物件所觸碰的第二電極的二位置，且與第一感測電路同步致動。在步驟330，掃描驅動電路230可能藉由感測對應於掃描電極的二位置的感測電容之變化的電容值依序且快速地掃描(不必要精確掃描)第一電極與第二電極的其中一個。接著，在步驟340，觸控面板的第三感測電路可能藉由感測對應於第三感測電路的掃描的電極的二位置之感測電容的電容值，順序地且大略地(亦即低解析度)定位二物件所碰觸的掃描的電極的二位置。最後，在步驟350，根據第一電極的二位置、第二電極的二位置以及掃描電極的二位置可能決定二碰觸點。FIG. 3 illustrates a sensing method of a touch panel according to an embodiment of the invention. The sensing method of the touch panel is adapted to sense two touch points when the touch panel touches two objects. First, in step 310, the first sensing circuit of the touch panel may position the two positions of the first electrode touched by the two objects by sensing the capacitance value corresponding to the change of the sensing capacitance of the two positions of the first electrode. . Next, in step 320, the second sensing circuit of the touch panel may position the two positions of the second electrode touched by the two objects by sensing the capacitance value corresponding to the change of the sensing capacitance of the two positions of the second electrode. And being actuated synchronously with the first sensing circuit. In step 330, the scan driving circuit 230 may sequentially (sequentially scan) the first electrode and the second electrode by sensing the capacitance value corresponding to the change of the sensing capacitance of the two positions of the scan electrode. One. Next, in step 340, the third sensing circuit of the touch panel may sequentially and roughly (ie, by sensing the capacitance value of the sensing capacitance of the two positions of the electrode corresponding to the scanning of the third sensing circuit. Low resolution) locates the two positions of the scanned electrodes that the two objects touch. Finally, at step 350, the two-touch contact may be determined based on the two positions of the first electrode, the two positions of the second electrode, and the two positions of the scan electrodes.

在發明的實施例中，根據第一電極的二位置以及第二電極的二位置，會有四個可能的碰觸點。因為第一感測電路與第二感測電路是同步操作，二感測電路同時感測四個點，其中包括二個鬼點。為了排除二個鬼點。舉例來說，第一電極可能依序地且大略地藉由掃描驅動電路以測試信號掃描，然後第三感測電路可能大略地感測對應於掃描的第一電極的感測電容的變化的電容值。所以二個可能的觸碰點可能根據掃描的第一電極更進一步驗證。舉例來說，當第一電極的每一列以少於0.2ms的時間被快速掃描，則第三感測電路的總掃描與感測時間是0.2*8=1.6m(假設第一電極的列數目是8)，其少於傳統互容式感測裝置。因此，容量8*8*8位元(512位元)的低解析度類比數位轉換器足夠應用於發明。In an embodiment of the invention, there are four possible bump contacts depending on the two positions of the first electrode and the two positions of the second electrode. Because the first sensing circuit and the second sensing circuit operate synchronously, the second sensing circuit simultaneously senses four points, including two ghost points. In order to rule out two ghost points. For example, the first electrode may scan the test signal sequentially and roughly by the scan driving circuit, and then the third sensing circuit may roughly sense the capacitance corresponding to the change of the sensing capacitance of the scanned first electrode. value. Therefore, two possible touch points may be further verified based on the scanned first electrode. For example, when each column of the first electrode is quickly scanned in less than 0.2 ms, the total scan and sensing time of the third sensing circuit is 0.2*8=1.6 m (assuming the number of columns of the first electrode) It is 8), which is less than the conventional mutual capacitance sensing device. Therefore, a low resolution analog digital converter with a capacity of 8*8*8 bits (512 bits) is sufficient for the invention.

此外，於發明的實施例，當電極的對應位置被觸碰，感測電容之改變的電容值變得較大。通常，臨界電容值係使用者設定，用於決定觸控面板的靈敏度。也就是說，當臨界電容值小，電容值的小變化可能觸發感測電路辨認到觸碰點。Further, in the embodiment of the invention, when the corresponding position of the electrode is touched, the capacitance value of the change in the sense capacitance becomes larger. Generally, the critical capacitance value is set by the user to determine the sensitivity of the touch panel. That is to say, when the critical capacitance value is small, a small change in the capacitance value may trigger the sensing circuit to recognize the touch point.

最後，熟此技藝者可體認到他們可以輕易地使用揭露的觀念以及特定實施例為基礎而變更及設計可以實施同樣目的之其他結構且不脫離本發明以及申請專利範圍。In the end, it is obvious to those skilled in the art that they can easily use the disclosed concept and the specific embodiments to change and design other structures that can perform the same purpose without departing from the invention and the scope of the claims.

100．．．自容式觸控感測裝置100. . . Self-capacitive touch sensing device

110．．．第一感測電路110. . . First sensing circuit

120．．．第二感測電路120. . . Second sensing circuit

150．．．互容式觸控感測裝置150. . . Mutual touch touch sensing device

160．．．掃描驅動電路160. . . Scan drive circuit

170．．．感測電路170. . . Sense circuit

180．．．類比數位轉換器180. . . Analog digital converter

200．．．感測系統200. . . Sensing system

202．．．複數個第一電極202. . . Multiple first electrodes

204．．．複數個第二電極204. . . Multiple second electrodes

206．．．感測電容206. . . Sense capacitance

210．．．第一感測電路210. . . First sensing circuit

220．．．第二感測電路220. . . Second sensing circuit

230．．．掃描驅動電路230. . . Scan drive circuit

240．．．第三感測電路240. . . Third sensing circuit

250．．．控制電路250. . . Control circuit

310、320、330、340、350．．．方法步驟310, 320, 330, 340, 350. . . Method step

第1a圖顯示傳統觸控面板的感測裝置的示意圖；1a is a schematic view showing a sensing device of a conventional touch panel;

第1b圖顯示另一傳統觸控面板的感測裝置的示意圖；FIG. 1b is a schematic view showing a sensing device of another conventional touch panel;

第2圖顯示發明的觸控面板的感測裝置的示意圖；以及2 is a schematic view showing a sensing device of the inventive touch panel;

第3圖係根據發明的實施例說明觸控面板的感測方法。FIG. 3 illustrates a sensing method of a touch panel according to an embodiment of the invention.

200．．．感測系統200. . . Sensing system

202．．．複數個第一電極202. . . Multiple first electrodes

204．．．複數個第二電極204. . . Multiple second electrodes

206．．．感測電容206. . . Sense capacitance

210．．．第一感測電路210. . . First sensing circuit

220．．．第二感測電路220. . . Second sensing circuit

230．．．掃描驅動電路230. . . Scan drive circuit

240．．．第三感測電路240. . . Third sensing circuit

250．．．控制電路250. . . Control circuit