1. Field of the Invention
The present invention relates to a touch display device, and, more particularly, to a touch display device capable of determining the plurality of touching points.
2. Description of the Related Art
With technology improvement, many electronic devices have touch display devices, such as PDAs, mobile phones, or panel computers. Due to its operation convenience, the touch display device has become more and more common on different electronic devices. The resistive touch display device requires lower manufacturing cost and easier operation manner, therefore, the resistive touch display device is more popular.
However, in prior art technology, the resistive touch display device does not have a control module capable of determining two or a plurality of touching points at the same time, and users can only control one touching point while operating the touch display device. If the touch display device can have different touching control methods, it might have more various control manners and performance.
Therefore, it is desirable to provide a touch display device capable of determining the plurality of touching points to mitigate and/or obviate the aforementioned problems.
A main objective of the present invention is to provide a touch display device capable of determining the plurality of touching points.
Another objective of the present invention is to provide a method of determining the plurality of touching points for a touch display device.
In order to achieve the above-mentioned objectives, a touch display device a control module, and a resistive touch panel. The resistive touch panel comprises a first electrical conductive layer and a second electrical conductive layer. The first electrical conductive layer and the second electrical conductive layer have a first electrode, a second electrode, a third electrode, and a fourth electrode, a control module, and a resistive touch panel. The control module electrically connected to the first electrode, the second electrode, the third electrode and the fourth electrode. Wherein when a plurality of touching points are generated between the first electrical conductive layer and the second electrical conductive layer, the control module repeatedly selects two electrodes in non-repeated combinations among the first electrode, the second electrode, the third electrode and the fourth electrode, applies a voltage value difference to the two selected electrodes, and measures two voltage values from the non-selected electrode, to obtain two voltage values, and then utilizing the same way to obtain a plurality of voltage values; the control module utilizes the plurality of voltage values to calculate a plurality of equivalent resistive values formed among the first electrode, the second electrode, the third electrode, the fourth electrode and the plurality of touching points and obtains the positions of the plurality of touching points according to the plurality of equivalent resistive values.
The method of the present invention comprises the steps of: when the first and the second electrical conductive layers have a plurality of touching points, selecting two electrodes in non-repeated combinations among the first electrode, the second electrode, the third electrode or the fourth electrode, applying a voltage value difference to the two selected electrodes, and obtaining two voltage values from the non-selected electrode to obtain two voltage values, and then utilizing the same way to obtain a plurality of voltage values; according to the plurality of voltages, calculating a plurality of equivalent values of resistors; and obtaining the position of the plurality of touching points.
Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
Please refer to
In one embodiment of the present invention, a touch display device 10 can be used for determining a plurality of touch points. As shown in
As shown in
An inputting object (not shown), such as a touch pen, applies pressure onto the first electrical conductive layer 31 to touch the second electrical conductive layer 32 and generate at least one touching point. Since the first electrical conductive layer 31 touches the second electrical conductive layer 32 and causes a short circuit, a voltage drop is generated. The measuring unit 22 measures the voltage value of the third electrode 321 or the fourth electrode 322 to determine whether the first electrical conductive layer 31 touches the second electrical conductive layer 32. Moreover, the switching circuit 23 enables the control module 21 to control the connection between the first electrode 311, the second electrode 312, the third electrode 321 or the fourth electrode 322 on the resistive touch panel 30 and the measuring unit 22, the power supply end or the grounded end. The control module 21 repeatedly selects two electrodes in non-repeated combinations to be connected to the power supply end or the grounded end, applies a voltage value difference to the two selected electrodes, and measures two voltage values from the non-selected electrode by the measuring unit 22, to obtain two voltage values, and then utilizes the same way to obtain a plurality of voltage value. Therefore, it is determined whether there are a plurality of touching point between the first electrical conductive layer 31 and the second electrical conductive layer 32; and the positions of the plurality of the touching points are further identified. Following description will explain how to identify the position of the plurality of touching points.
As shown in
An inputting object (not shown), such as a touch pen, applies pressure onto the first electrical conductive layer 31′ to touch the second electrical conductive layer 32′ and generate at least one touching point. Since the first electrical conductive layer 31′ touches the second electrical conductive layer 32′ and causes a short circuit, a voltage drop is generated. The measuring unit 22′ measures the voltage value of the sensing electrode 311′ to determine whether the first electrical conductive layer 31′ touches the second electrical conductive layer 32′. Moreover, the switching circuit 23 enables the control module 21 to control the connection between the first electrode 321′, the second electrode 322′, the third electrode 323′ or the fourth electrode 324′ the on the resistive touch panel 30′ and the power supply end or the grounded end. The control module 21 repeatedly selects two electrodes in non-repeated combinations to be connected to the power supply end or the grounded end, applies a voltage value difference to the two selected electrodes, and measures two voltage values from the non-selected electrode by the measuring unit 22, to obtain two voltage values, and then utilizes the same way to obtain a plurality of voltage value. Therefore, it is determined whether there are a plurality of touching point between the first electrical conductive layer 31′ and the second electrical conductive layer 32′; and the positions of the plurality of the touching points are further identified. Following description will explain how to identify the position of the plurality of touching points.
Please refer to
Step 201: determining whether there are a plurality of touching points generated between the first electrical conductive layer and the second electrical conductive layer.
First, the control module 21 controls and applies a voltage value difference to two electrodes electrically connected the power supply end and the grounded end on the resistive touch panel 30. Then, the control module 21 measures the voltage value of the other two electrodes to determined whether there is a voltage value difference, as an equivalent circuit in the first embodiment shown in
However, the above mentioned connections are just examples. For example, the measuring unit 22 might be used to individually measure the voltage values of the first electrode 311 and the second electrode 312 by electrically connecting the third electrode 321 with the power supply end, and electrically connecting the fourth electrode 322 with the grounded end. Alternatively, the measuring unit 22 might be used to measure the voltage values of the third electrode 321 by separately electrically connecting the first electrode 311 and the second electrode 312 with the power supply end and the grounded end.
When it is determined that the plurality of touching points exist between the first electrical conductive layer 31 and the second electrical conductive layer 32, step 202 is performed.
Step 202: selecting two electrodes repeatedly in non-repeated combinations among the first electrode, the second electrode, the third electrode or the fourth electrode, and applying a voltage value difference to the selected electrodes.
The control module 21 utilizes the switching circuit 23 to repeatedly selects two electrodes electrically connected to the power supply end or the grounded end are in non-repeated combinations among the first electrode 311, the second electrode 312, the third electrode 321 and the fourth electrode 322, and applies a voltage value difference.
Simultaneously, step 203 is also performed: selecting the remaining electrodes electrically connected the measuring unit to obtain the plurality of voltage values.
The control module 21 utilizes the switching circuit 23 to selecting the remaining electrodes electrically connected the measuring unit 22 to obtain the plurality of voltage values. If in step 202 the first electrode 311 electrically connected to the power supply end and the second electrode 312 electrically connected to the grounded end are selected, and then the measuring unit 22 is controlled to measure the voltage value of the third electrode 321. Next, the first electrode 311 electrically connected to the grounded end and the second electrode 312 electrically connected to the power supply end selected, and then the measuring unit 22 is controlled to measure the voltage value of the third electrode 321. Therefore, two different voltage values of the third electrode 321 can be obtained. Then, the connection can be change by a non-repeated combinations selecting the third electrode 321 being electrically connected to the power supply end, the fourth electrode 322 being electrically connected to the grounded end, and the measuring unit 22 separately measures the voltage value of the first electrode 311 and the second electrode 312. By repeating the step 202 and step 203 to measure the voltage value of each electrode of the first electrical conductive layer 31 and the second electrical conductive layer 32, the plurality of voltage value is obtained.
Step 204: calculating the plurality of equivalent values of resistors among the first electrode, the second electrode, the third electrode, the fourth electrode, the first touching point and the second touching point.
After the plurality of voltage values are obtained, according to the voltage is proportional to the resistance theory, the plurality of equivalent values of resistors among the first electrode 311, the second electrode 312, the third electrode 321, the fourth electrode 322, the first touching points T1, T1′ and the second touching points T2, T2′ can be calculated out. Taking the equivalent circuit in the first embodiment shown in
However, the number of the resistor can be different than the number in the first embodiment. In order to have more accurate calculation, there can be more resistors between the first electrical conductive layer 31 and the second electrical conductive layer 32, as the second embodiment shown in
After calculating the plurality of equivalent resistors, step 205 is performed: calculating the positions of the plurality of touching points. According to the distance is proportional to the resistance theory, the positions of the plurality of touching points are obtained. In the first embodiment, since the total resistance value from the first electrode 311 to the second electrode 312 and the third electrode 321 to the fourth electrode 322 is fixed, after the eight sets of equivalent values of resistors between the first electrical conductive layer 31 and the second electrical conductive layer 32 are obtained, the positions of the first touching points T1, T1′ and the second touching points T2, T2′ can be obtained by applying equal proportion principle.
Furthermore, the method of determining the plurality of touching points of the present invention can have different step sequence than the above mentioned step sequence.
In addition, the method of determining the plurality of touching points can also be applied in the 5-wire resistive touch panel 30′ shown in
In this embodiment, the first touching point T1, T1′ and the second touching point T2, T2′ exist between the first electrical conductive layer 31′ and the second electrical conductive layer 32′. As shown in
With the above-mentioned method, the resistive touch panel 30′ can determine the plurality of touching point.
Finally, please refer to
The touch display device 10 can be installed on an electronic device 40 for the user to operate the electronic device 40. The electronic device 40 can be a panel computer, a mobile phone, a PDA or any other similar electronic devices. A user can use two touch pens to touch the touch display device 10, the touch display device 10 can obtain two touching points at the same time and perform further related procedure. Therefore, the electronic device 40 can provide more various control method.
Although the present invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed.
Number | Date | Country | Kind |
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096143436 | Nov 2007 | TW | national |