TWI426434B - Surface capacitive touch device and control method thereof - Google Patents

Description

Surface capacitive touch device and control method thereof

The present invention relates to a surface capacitive touch device, and more particularly to a surface capacitive touch device capable of reducing current consumption.

With the rapid development of technology, the performance requirements for electronic products are also increasing day by day, such as miniaturization of size, convenience of carrying, and ease of operation. Because touch technology can save the use of the keyboard. Therefore, electronic products with touch technology have gradually been applied to automatic deposit and withdrawal machines (ATMs) and mobile phones.

One of the touch technologies is surface capacitive touch technology. Such a surface capacitive touch device utilizes a current flowing to one of the four corners of the panel to determine the position of the finger. However, the current use of medium-sized surface capacitive touch devices, such as automatic depositors, consumes at least about 50 milliamps (mA). If the portable surface capacitive touch device still has such a large current consumption, it is not suitable for long-term use.

In view of this, the embodiment of the present invention provides a surface capacitive touch device having a power saving mode and a control method thereof, which greatly reduces the current consumption by reducing the output power of the driving circuit to the surface capacitive touch panel. The use time of the portable surface capacitive touch device.

According to an embodiment of the present invention, a method for controlling a surface capacitive touch panel is provided, the method comprising: providing a first output power to the surface capacitive touch panel to discharge the four corners of the surface capacitive touch panel; An object touch surface capacitive touch panel is not detected within a predetermined time period, and a second output power is provided to the surface capacitive touch panel, wherein the second output power is less than the first output power.

According to another embodiment of the present invention, a surface capacitive touch device is proposed. The surface capacitive touch device comprises a surface capacitive touch panel and a driving circuit. The driving circuit is coupled to the surface capacitive touch panel for providing an output power to the surface capacitive touch panel touch panel, so that the four corners of the surface capacitive touch panel are discharged, wherein the predetermined time is not An object is detected to touch the surface capacitive touch panel, and the driving circuit reduces the output power.

In order to make the above-mentioned contents of the present invention more comprehensible, the following specific embodiments, together with the drawings, are described in detail below:

Please refer to FIGS. 1 and 2 together. FIG. 1 is a diagram showing a surface capacitive touch device 10 according to an embodiment of the present invention. FIG. 2 is a diagram showing a control method of the surface capacitive touch device 10 of FIG. As shown in FIG. 1 , the surface capacitive touch device 10 includes a surface capacitive touch panel 12 and a driving device 14 . The four corners 122, 124, 126 and 128 of the surface capacitive touch panel 12 are electrically connected to the driving circuit 14.

When the surface capacitive touch device 10 is in the normal mode, the driving circuit 14 provides a first output power to the surface capacitive touch panel 12 (step S210), so that the four corners 122, 124 of the surface capacitive touch panel 12 The 126 and 128 discharges allow the surface capacitive touch device 10 to sense the object. For example, if the user's finger 13 touches the position of the surface capacitive touch panel 12, the surface capacitive touch device 10 can perform an operation to detect the position of the touch contact.

The surface capacitive touch device 10 detects whether the object touches the surface capacitive touch panel 12 (for example, step S220) within a predetermined time period, for example, 5 minutes. If so, the drive circuit 14 continues to provide the first output power. If the object does not detect that the surface capacitive touch panel 12 is touched within the preset time, the surface capacitive touch device 10 enters a power saving mode, such as a sleep mode. In the power saving mode, the driving circuit 14 provides the second output power to the surface capacitive touch panel 12, wherein the second output power is less than the first output power (step S230). That is, when the surface capacitive touch device 10 enters the power saving mode from the normal mode, the driving circuit 14 reduces its output power to reduce the current consumption.

The driving circuit 14 can reduce the output voltage/current output to the surface capacitive touch panel 12 (as in step S231) or can reduce the scanning frequency of the surface capacitive touch panel 12 (as in step S232) to reduce the output power.

If the driving circuit 14 reduces the output voltage output to the surface capacitive touch panel 12 to reduce the output power, the driving circuit 14 can stop the output power of at least one of the four corners 122, 124, 126 and 128 of the surface capacitive touch panel 12. And the normal output power is given to at least one corner to reduce the output voltage. For example, when in the normal mode, the output current of the driving circuit 14 to the four corners 122, 124, 126, and 128 of the surface capacitive touch panel 12 is 10 milliamperes (mA), respectively; in the surface capacitive touch device 10 After entering the power saving mode, the driving circuit 14 stops outputting the voltage to one corner of the surface capacitive touch panel 12 (such as the corner 122), but for other triangles 124, 126 and 128, the normal output voltage (for example, its current is 10 mA), The drive circuit 14 is caused to reduce the output voltage to the surface capacitive touch panel 12.

Alternatively, the driving circuit 14 can stop the output voltage to the triangle of the surface capacitive touch panel 12 (eg, 122, 124, 126), and only output the voltage to the corner 128 of the surface capacitive touch panel 12 to further reduce the voltage. The output voltage of the surface capacitive touch panel 12.

In addition, the driving circuit 14 can reduce the output voltage (for example, halving the output voltage) output to at least one corner (eg, the angle 122) of the four corners 122, 124, 126, and 128 of the surface capacitive touch panel 12 to reduce the surface capacitance. The output power of the touch panel 12 . For example, when the surface capacitive touch device 10 is in the normal mode, the output voltage of the driving circuit 14 to the four corners 122, 124, 126 and 128 of the surface capacitive touch panel 12 is as shown in FIG. 3A. After the surface capacitive touch device 10 enters the power saving mode, as shown in FIG. 3B, the driving circuit 14 halved the output voltage of at least one corner of the four corners of the surface capacitive touch panel 12. Alternatively, the driving circuit 14 reduces the output voltage of the four corners of the four corners 122, 124, 126, and 128 of the surface capacitive touch panel 12 (such as halving the output voltage) to reduce the surface capacitive touch panel 12 Output Power.

In addition, after the surface capacitive touch device 10 enters the power saving mode, as shown in FIG. 3C, the driving circuit 14 can also reduce the scanning frequency outputted to the surface capacitive touch panel 12 by half to reduce the output power.

If the user wants to operate the surface capacitive touch device 10, the user's finger 13 touches the normal discharge angle, and the driving circuit 14 can restore the first output power to the surface capacitive touch panel 12 (step S250). The surface capacitive touch device 10 can perform an operation according to the position where the object touches.

In other embodiments, the driver circuit 14 can further reduce the output power by reducing the scan frequency and reducing the output voltage to reduce current consumption.

In the embodiment of the present invention, whether the driving circuit 14 reduces the scanning frequency or reduces the output voltage, the surface capacitive touch device 10 can still detect whether the object touches the surface capacitive touch panel 12 in this case. That is, in the power saving mode, after the surface capacitive touch device 10 detects that the object touches the surface capacitive touch panel 12, the driving circuit 14 returns to provide the first output power (such as step S250), so that the surface capacitance The touch device 10 can detect the position of the object touching the surface capacitive touch panel 12.

Therefore, after the surface capacitive touch device proposed in the embodiment of the present invention enters the power saving mode, the driving circuit reduces the output power of the surface capacitive touch panel, and the current consumption of the surface capacitive touch device is greatly reduced. When the surface capacitive touch device of the embodiment of the present invention uses a battery to supply power, the use time/standby time can be greatly increased.

In conclusion, the present invention has been disclosed in the above embodiments, but it is not intended to limit the present invention. A person skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

10. . . Surface capacitive touch device

12. . . Surface capacitive touch panel

13. . . finger

14. . . Drive circuit

122, 124, 126, 128. . . angle

S210, S220, S230, S231, S232, S250. . . step

FIG. 1 is a schematic view showing a surface capacitive touch device according to an embodiment of the invention.

2 is a flow chart showing a control method of the surface capacitive touch device of FIG. 1.

FIG. 3A is a waveform diagram showing the output voltage of the driving circuit outputted to one of the corners of the surface capacitive touch panel in the normal mode in the surface capacitive touch device of FIG. 1 .

FIG. 3B is a waveform diagram showing the output voltage of the driving circuit outputted to one corner of the surface capacitive touch panel in the power saving mode of the surface capacitive touch device of FIG. 1 , wherein the amplitude of the output voltage is decreased.

FIG. 3C is a diagram showing another waveform example of the output voltage of one corner of the surface capacitive touch panel in the power saving mode of the surface capacitive touch device of FIG. 1 , wherein the frequency of the output voltage reduce.

S210, S220, S230, S231, S232, S250. . . step

Claims (12)

A control method for a surface capacitive touch panel includes: providing a first output power to the surface capacitive touch panel to discharge the four corners of the surface capacitive touch panel; and within a preset time An undetectable object touches the surface capacitive touch panel to provide a second output power to the surface capacitive touch panel, so that at least one corner of the four corners of the surface capacitive touch panel stops discharging and at least one corner is Discharging; wherein the second output power is less than the first output power. The control method of claim 1, further comprising: when the object touches the surface capacitive touch panel, responsive to providing the first output power to the surface capacitive touch panel. The control method of claim 1, wherein the second output power is provided by lowering a scan frequency. The control method of claim 1, wherein the second output power is provided by reducing an output voltage. The control method of claim 4, wherein: touching the at least one corner of the surface capacitive touch panel to discharge the first output power to the surface capacitive touch panel. The control method of claim 4, wherein: reducing the output voltage to reduce the at least one corner discharge of the surface capacitive touch panel by half; and touching the surface capacitive touch panel to provide a response The first output power is to the surface capacitive touch panel. A surface capacitive touch device includes: a surface capacitive touch panel; and a driving circuit coupled to the surface capacitive touch panel for providing an output power to the surface capacitive touch panel, such that The four-corner discharge of the surface capacitive touch panel; wherein an object is not detected to touch the surface capacitive touch panel within a predetermined time, the driving circuit reduces the output power, so that the surface capacitive touch panel At least one of the four corners stops discharging and at least one corner is a discharge. The surface capacitive touch device of claim 7, wherein the driving circuit returns the output power to the surface capacitive touch panel when the object touches the surface capacitive touch panel. The surface capacitive touch device of claim 7, wherein the driving circuit reduces the output power by reducing a scanning frequency. The surface capacitive touch device of claim 7, wherein the driving circuit reduces the output power by reducing an output voltage. The surface capacitive touch device of claim 10, wherein the corner of the surface capacitive touch panel that touches the discharge causes the driving circuit to revert to provide the output power to the surface capacitive touch panel. . The surface capacitive touch device of claim 10, wherein the driving circuit reduces the output voltage such that the at least one corner discharge of the surface capacitive touch panel is halved; and touching the surface capacitive touch The control panel causes the driving circuit to return to provide the output power to the surface capacitive touch panel.