TWI472971B - An electronic device and sensing method - Google Patents

Description

Electronic device and detection method

The present invention relates to a touch device, and more particularly to a touch panel having a proximity sensor having a multiplexer circuit and a proximity sensing method.

Today's mobile phones or tablets have a proximity sensing device, and the proximity sensing application is differentiated according to the size of the touch panel. For example, the size of the mobile phone is small, and the size of the tablet is large. . On small-sized mobile phones, the proximity sensing application is to turn the display panel on or off, and to turn off the touch function to avoid user malfunction.

Figure 1A is a schematic diagram showing the proximity sensing device interface of a conventional mobile phone using an infrared sensor and receiver (Infrared Ray Sensor/Receiver). Figure 1B is a schematic diagram showing the proximity sensing device interface of a conventional mobile phone using a capacitive sensor. Traditional mobile phones detect objects in two ways, one is an infrared sensor/receiver, and the other is a capacitive proximity sensor. For example, as shown in FIG. 1A, the infrared sensor 110 emits infrared light, and the infrared receiver 120 receives the light reflected from the object, thereby detecting the distance between the object and the emission source. The infrared receiver 120 in FIG. 1A communicates with the baseband module of the mobile phone through the I2C interface, and when the infrared receiver 120 transmits, the controller needs an interrupt. The I2C signal from the touch panel 130 may cause the transmission and processing speed of the baseband module to be slow, and the signal may be blocked. As shown in FIG. 1B, the capacitive sensor 140 utilizes the amount of increase in the sense capacitance of the conductive object to determine the relative distance of the object from the capacitive sensor 140. The capacitive sensor 140 and the touch panel 150 in FIG. 1B share the same I2C channel, so that there is no problem of signal interruption and blockage. The sensing distance of the capacitive proximity sensor is related to the overall capacitance of the conductive object, and the capacitive proximity sensor is usually placed in a small area above the touch panel in the mobile phone, so the sensing distance is quite limited.

In view of the above, the present invention provides an electronic device, including: a touch panel, comprising a plurality of sensing electrodes for sensing a touch action on the touch panel to output a corresponding touch signal or sensing proximity An object moving action of the touch panel outputs a corresponding sensing signal; a multiplex circuit coupled to the sensing electrode for outputting a driving signal to the sensing electrode; and a control circuit for switching the signal according to a mode The electronic device switches to a touch sensing mode or a proximity sensing mode, and sends a corresponding control signal to the multiplex circuit according to the mode switched by the electronic device, to control the multiplex circuit coupling output to the sensing electrodes. The way.

The invention further provides a detection method for an electronic device, the electronic device comprising a touch panel having a plurality of sensing electrodes. The method includes the following steps: switching the electronic device to a touch sensing mode or a proximity sensing mode according to a mode switching signal; and cutting according to the electronic device The changed mode emits a corresponding control signal to control the manner in which the output of a driving signal to the sensing electrodes is coupled.

2 is a block diagram showing a proximity sensing device in accordance with an embodiment of the present invention. The proximity sensing device 200 is for a handheld device (eg, a smart phone, tablet, or other similar electronic device). In an embodiment, the proximity sensing device 200 includes a touch panel 210, a multiplex circuit 220, and a control circuit 230. The touch panel 210 has a plurality of sensing electrodes 211 213 213 for sensing a touch action on the touch panel 210 to output a corresponding touch signal or to sense an object moving motion of the touch panel. A corresponding sensing signal is output, wherein each of the sensing electrodes 211 213 213 can be respectively a conductive channel, so that a plurality of inductors can be connected in series. In this embodiment, the touch panel 210 can be a capacitive touch panel, and each of the sensing electrodes 211 213 can be a capacitive sensor, but the invention is not limited thereto. . Generally, the size of the touch panel of the handheld device is quite limited. Therefore, the relative distance and action of the capacitive touch panel to detect the object are also limited to a distance (about 3 cm) which is relatively close to the touch panel. It is difficult to use gestures to control the phone. The multiplex circuit 220 is coupled to the sensing electrodes (eg, the sensing electrodes 211 213 213 ) and the control circuit 230 in the touch panel 210 (for example, on the glass of the touch panel, on the thin film transistor substrate of the liquid crystal panel, or on the electronic device) a circuit board or the like) receives a control signal (in this embodiment, 2 bits) from the control circuit 230 for outputting a driving signal 221 to the touch The sensing electrodes (eg, sensing electrodes 211 to 213) in the control panel 210. The control circuit 230 sends a corresponding control signal 231 to the multiplex circuit 220 according to the mode switched by the electronic device to control the manner in which the multiplex circuit 220 is coupled to the sensing electrodes in the touch panel. In another embodiment, control circuit 230 can be implemented with a processor or a digital circuit. It should be noted that the driving signal 221 output by the multiplex circuit 220 may be from a reference voltage or from the control circuit 230.

In an embodiment, the proximity sensing device 200 selectively includes a switching unit 240 for receiving a mode switching signal, and switching the proximity sensing device 200 to a touch sensing mode or a proximity sensing mode. A mode signal 241 is input to the control circuit 230, wherein the mode switching signal can be from a software (such as an application) or a hardware (such as a cell phone button). In another embodiment, the switching unit 240 can be integrated into the control circuit 230, but the invention is not limited thereto.

FIG. 3A is a simulation diagram showing the sensing distance of the touch panel according to an embodiment of the invention. 3B, 3C are diagrams showing active areas in accordance with an embodiment of the present invention. For example, if the sensing distance is 3 cm, an area of 300 mm ² is required on the 4.3-inch touch panel, and a small area above the touch panel can be achieved, such as the sensing area 310 of FIG. 3B. If a sensing distance (for example, 5 cm or more) is required, the area of the sensing area of the touch panel needs to be at least 500 mm ² , so that the proximity sensing device 200 needs to use the active area in the touch panel 210 (active). The area is used as the sensing area, such as the sensing area 320 in FIG. 3C.

In more detail, the control circuit 230 can switch the proximity sensing device 200 in two modes, one is a touch sensing mode, and the other is a proximity sensing mode. When the proximity sensing device 200 is switched to the touch sensing mode, the control circuit 230 sends a control signal 231 to the multiplex circuit 220 corresponding to the touch sensing mode for the multiplex circuit 220 to output the driving signal 221 in a time division manner. To the corresponding sensing electrodes for scanning detection. When the proximity sensing device 200 switches to the proximity sensing mode, the control circuit sends a control signal corresponding to the proximity sensing mode to the multiplex circuit 220 for the multiplex circuit 220 to connect at least three sensing electrodes in the touch panel 210. (For example, the sensing electrodes 211 to 213) are connected in parallel, and the driving signal 221 is output to the sensing electrodes connected in parallel. For example, as shown in Table 1, the control signal 231 issued by the control circuit 230 is 2 bits. When the touch panel 210 is in the touch sensing mode, the control circuit 230 sequentially outputs the control signals 231 to 01, 00, and 10, and the multiplex circuit 220 outputs the driving signals 221 to the sensing electrodes 211 and 212, respectively. 213 to perform scanning detection. When the touch panel 210 is in the proximity sensing mode, the control signal 231 outputted by the control circuit 230 is 11, and the multiplex circuit 220 connects the sensing electrodes 211 to 213 in parallel, and outputs the driving signal 221 to the parallel sensing electrodes. 211~213. For a 4.3-inch touch panel, one sensing electrode has 11 inductors, and each sensor has an area of about 11.13 mm ² , so the total area of the three sensing electrodes in parallel can reach 15.13 × 11 × 3=500mm ² . Compared with the simulation result of FIG. 4, when the sensing area of the proximity sensing device reaches 500 mm ² , it indicates that the sensing capability can reach a height of 50 mm, which is more convenient for the user to operate the handheld device by using gestures. It should be noted that the above embodiment is exemplified by a 4.3-inch touch panel, and the touch panel has at least three sensing electrodes, but the present invention is not limited thereto. If a tablet computer with a 7-inch touch panel is taken as an example, the total area of the three sensing electrodes can be greatly increased, that is, the sensing distance can be greatly increased. In the present invention, more than three sensing electrodes can be used, and only additional control signal bits need to be added to the control circuit 230. For example, four sensing electrodes require a 3-bit control signal.

Figure 4A is a logic block diagram showing a multiplex circuit in accordance with an embodiment of the present invention. Figure 4B is a circuit diagram showing a multiplex circuit in accordance with an embodiment of the present invention. As shown in FIG. 4A, the multiplex circuit 220 can be a multiplexer, and the control signal 231 sent by the control circuit 230 can control the multiplex circuit 220 to output the driving signal 221 to the sensing electrodes 211 to 231. (Touch sensing mode) or output driving signal 221 to parallel sensing electrodes 211~213 (near sensing mode). In more detail, the multiplex circuit 220 can be implemented by the circuit in FIG. 4B, and its truth table is as shown in Table 1. As shown in FIG. 4B, the multiplex circuit 220 includes the transistors T1 to T6, and the touch panel includes the sensing electrodes 1 to 3. The first end of the transistor T1 is coupled to the reference voltage V _ref , and the control thereof is controlled. The end is coupled to the bit 0 (first bit) of the control signal; the first end of the transistor T2 is coupled to the second end of the transistor T1, and the control end is coupled to the bit 1 of the control signal The second end is coupled to the sensing electrode 2; the first end of the transistor T3 is coupled to the reference voltage V _ref , and the control end is coupled to the bit 1 of the control signal. The second end is coupled to the sensing electrode 3; the first end of the transistor T4 is coupled to the reference voltage V _ref , the control end is coupled to the bit 1 of the control signal; the first end of the transistor T5 is coupled Connected to the second end of the transistor T4, the control end is coupled to the bit 0 of the control signal, and the second end is coupled to the sensing electrode 2; the first end of the transistor T6 is coupled to the reference voltage V _Ref , the control end is coupled to the bit 0 of the control signal, and the second end is coupled to the sensing electrode 1 . In this embodiment, the transistors T1, T2, T3 and T6 are N-type transistors, and the transistors T4 and T5 are P-type transistors, but the invention is not limited thereto.

When the touch panel 210 is in the touch sensing mode, the control circuit 230 sequentially outputs the control signals 01, 00, and 10, and the multiplex circuit 220 sequentially outputs the driving signals 221 to the sensing electrodes 211 and 212, respectively. 213 to perform scanning detection. When the touch panel 210 is in the proximity sensing mode, the control signal 231 outputted by the control circuit 230 is 11, and the multiplex circuit 220 connects the sensing electrodes 211 to 213 in parallel, and outputs the driving signal 221 to the parallel sensing electrodes. 211~213. It will be apparent to those skilled in the art that the present invention can group sensing electrodes in a touch panel (e.g., a set of three sensing electrodes, but not limited) to configure a corresponding multiplex circuit 220. When the touch operation is performed by the touch panel 210 in the touch sensing mode, the control circuit 230 can control the multiplex circuit 220 to sequentially output the driving signal 221 to the sensing electrodes. When the user operates with the gesture in the proximity sensing mode, the control circuit 230 controls the multiplex circuit 220 to touch At least three sensing electrodes in the control panel 210 are connected in parallel, and the driving signal 221 is output to the parallel sensing electrodes. It should be noted that the touch signal or the sensing signal generated by the sensing electrode in the touch panel 210 can be output to a back-end circuit (not shown in FIG. 2) for subsequent processing, that is, the back-end circuit can be The touch signal and the sensing signal are converted into corresponding control commands.

In more detail, the usage mode of the touch panel 210 can be controlled by the switching unit 240, and the touch sensing mode and the proximity sensing mode can also be performed simultaneously. In this embodiment, the control circuit 230 of the integrated switching unit 240 is taken as an example. For example, a person makes a call to the handheld device where the proximity sensing device 200 is located. Before the user has not answered the call, the control circuit 230 causes the touch panel to process the touch sensing mode. Before the user answers the call but the face is not close to the touch panel 210, the control circuit 230 controls the sensing electrodes in the touch panel 210 to be in the touch sensing mode and the proximity sensing mode at the same time, and the user can The operation is performed on the touch panel 210. The touch panel 210 also continuously detects whether the user brings the face closer to the touch panel 210. When the user's face is close to the touch panel 210, the control circuit 230 switches the touch panel 210 to the proximity sensing mode to prevent the user from accidentally touching. When the touch panel 210 is in the touch sensing mode and the proximity sensing mode, the control signals sent by the control circuit 230 are sequentially 01, 00, 10, and 11, meaning that the sensing electrodes 211 213 213 can simultaneously detect Measure the touch action and gesture action on the touch panel. In another embodiment, when the user wants to switch the proximity sensing device 200 from the touch sensing mode to the proximity sensing mode to perform a remote sensing operation, the user can operate the proximity sensing device 200. The software or button inputs a mode switching signal to the control circuit 230 for switching the corresponding mode.

FIG. 5A is a schematic diagram showing a touch key on a touch panel according to an embodiment of the invention. Figure 5B is a logic block diagram showing a multiplex circuit in accordance with another embodiment of the present invention. . In another embodiment, on the 4.3 inch touch panel 210, one of the sensing buttons has a size of 7 mm x 7 mm, meaning that the area of one sensor is 49 mm ² as shown in FIG. 5A. In the embodiment, the touch panel 210 has four sensing buttons 610-640. Therefore, the total area of the sensing electrodes a to d corresponding to the four sensing buttons 610-640 is approximately 200 mm ^{2 .} And its sensing distance can reach a height of 20mm. In more detail, the multiplex circuit 220 in this embodiment may be a multiplexer, but has a 3-bit control signal as shown in FIG. 5B.

The multiplex circuit 220 of the present invention can also parallelly connect the sensing electrodes a~d corresponding to the four sensing buttons, thereby increasing the area of the proximity sensing area and increasing the sensing distance. In addition, please refer to Table 2, the processing manner of the sensing electrodes a~d of the sensing button is similar to the foregoing embodiment, that is, when the touch panel 210 is in the touch sensing mode, the control circuit 230 is sequentially issued. A control signal 001, 010, 000 and 100 to the multiplex circuit 220. At this time, the multiplex circuit 220 sequentially outputs the driving signal 221 to the sensing electrodes a~d corresponding to the sensing buttons 610-640. When the touch panel 210 is in the proximity sensing mode, the control signal 231 sent by the control circuit 230 is 111. At this time, the multiplex circuit 220 connects the sensing electrodes a~d corresponding to the sensing buttons 610-640 in parallel, and The drive signal is output to the parallel sense electrodes a~d. It should be noted that this embodiment is exemplified by four sensing buttons, and those skilled in the art will understand that the present invention is equally applicable to different numbers of sensing buttons.

Figure 6 is a flow chart showing a method of detecting according to an embodiment of the present invention. In step S710, the control circuit 230 switches the proximity sensing device 200 to a touch sensing mode or a proximity sensing mode according to a mode switching signal. In step S720, the control circuit 230 sends a corresponding control signal 231 according to the mode switched by the proximity sensing device 200, and is configured to control the multiplex circuit 220 to couple the driving signal 221 to the sensing electrode in the touch panel 210. the way.

Figure 7 is a flow chart showing a detection method in accordance with another embodiment of the present invention. In step S810, the control circuit 230 switches the proximity sensing device 200 to a touch sensing mode or a proximity sensing mode according to a mode switching signal. In step S820, the control circuit 230 issues a corresponding control signal 231 to the multiplex circuit 220 according to the mode switched by the proximity sensing device 200. In step S830, when the proximity sensing device 200 is in the touch sensing mode, the control circuit 230 sends a control signal 231 to the multiplex circuit 220 to allow the multiplex circuit 220 to output the driving signal 221 to the touch panel 210 in a time-sharing manner. Each of the sensing electrodes (for example, sensing electrodes 211 to 213). In the steps S840, when the proximity sensing device 200 is in the proximity sensing mode, the control circuit 230 sends a control signal 231 to the multiplexing circuit 220 to connect at least three sensing electrodes in the touch panel 210 in parallel, and causes the multiplexing circuit 220 to output a driving signal. 221 to parallel sensing electrodes (for example, sensing electrodes 211 to 213). For details of the implementation in Figures 6 and 7, refer to the foregoing embodiment, and details are not described herein again.

The above is only the embodiments of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent. In addition, any of the objects or advantages or features of the present invention are not required to be achieved by any embodiment or application of the invention. In addition, the abstract sections and headings are only used to assist in the search of patent documents and are not intended to limit the scope of the invention.

110‧‧‧Infrared sensor

120‧‧‧Infrared receiver

140‧‧‧ sensor

200‧‧‧ proximity sensing device

130, 150, 210‧‧‧ touch panels

211-213, a-d‧‧‧ sense electrodes

220‧‧‧Multiplex circuit

221‧‧‧ drive signal

230‧‧‧Control circuit

231‧‧‧Control signal

240‧‧‧Switch unit

241‧‧‧ mode signal

310-320‧‧‧ Sensing area

610-640‧‧‧Induction button

T1-T6, T61-T70‧‧‧O crystal

N1‧‧‧ node

Fig. 1A is a schematic diagram showing the interface of a proximity sensing device using a infrared sensor and a receiver in a conventional mobile phone.

Fig. 1B is a schematic view showing the interface of a proximity sensing device using a capacitive sensor of a conventional mobile phone.

2 is a block diagram showing a proximity sensing device in accordance with an embodiment of the present invention.

FIG. 3A is a simulation diagram showing the sensing distance of the touch panel according to an embodiment of the invention.

3B-3C are schematic views showing active areas in accordance with an embodiment of the present invention.

Figure 4A is a logic block diagram showing a multiplex circuit in accordance with an embodiment of the present invention.

Figure 4B is a circuit diagram showing a multiplex circuit in accordance with an embodiment of the present invention.

FIG. 5A is a schematic diagram showing a touch key on a touch panel according to an embodiment of the invention.

Figure 5B is a logic block diagram showing a multiplex circuit in accordance with another embodiment of the present invention.

Figure 6 is a flow chart showing a method of detecting according to an embodiment of the present invention.

Figure 7 is a flow chart showing a detection method in accordance with another embodiment of the present invention.

200‧‧‧ proximity sensing device

210‧‧‧Touch panel

211-213‧‧‧Induction electrode

220‧‧‧Multiplex circuit

221‧‧‧ drive signal

230‧‧‧Control circuit

231‧‧‧Control signal

240‧‧‧Switch unit

241‧‧‧ mode signal

Claims (11)

An electronic device includes: a touch panel including a plurality of sensing electrodes for sensing a touch action on the touch panel to output a corresponding touch signal or sensing an object approaching the touch panel Moving a signal to output a corresponding sensing signal; a multiplexing circuit coupled to the sensing electrodes for outputting a driving signal to the sensing electrodes; and a control circuit for switching the signals according to a mode switching signal The device switches to a touch sensing mode or a proximity sensing mode, and sends a corresponding control signal to the multiplex circuit according to the mode switched by the electronic device, to control the multiplex circuit coupling output to the The method of inducing an electrode, wherein the multiplex circuit comprises: a first transistor, the first end of which is coupled to a reference voltage, and the control end is coupled to the first bit of the control signal; The second end of the first transistor is coupled to the second end of the first transistor, the control end is coupled to one of the control signals, and the second end is coupled to the second end One of the sensing electrodes a third transistor, the first end of which is coupled to the reference voltage, the control end is coupled to the second bit of the control signal, and the second end is coupled to the sensing electrode a third sensing electrode; a fourth transistor having a first end coupled to the reference voltage, a control end coupled to the second bit of the control signal; a fifth transistor; The first end is coupled to the reference voltage, the control end is coupled to the first bit of the control signal, and the second end is coupled a second sensing electrode of the sensing electrodes; and a sixth transistor, the first end of which is coupled to the reference voltage, and the control end is coupled to the first bit of the control signal, The second end is coupled to one of the sensing electrodes, wherein the first transistor, the second transistor, the third transistor, and the sixth transistor are N-type transistors. And the fourth transistor and the fifth transistor system are P-type transistors. The electronic device of claim 1, wherein when the electronic device is in the touch sensing mode, the multiplex circuit outputs the driving signal to the corresponding sensing electrodes in a time division manner. The electronic device of claim 1, wherein when the electronic device is in the proximity sensing mode, the multiplex circuit connects at least three of the sensing electrodes in parallel, and outputs the driving signal to the parallel sensing. electrode. The electronic device of claim 1, wherein when the electronic device is in the proximity sensing mode, the sensing electrodes further determine a relative distance between an object and the touch panel to generate the sensing signal. The electronic device of claim 1, wherein the sensing electrodes are a plurality of sensing buttons. The electronic device of claim 1, wherein each of the sensing electrodes is composed of a plurality of inductors connected in series. A detecting method for an electronic device, comprising: a touch panel having a plurality of sensing electrodes, comprising: switching the electronic device to a touch sensing mode or a proximity sensor according to a mode switching signal Measuring mode; emitting a corresponding control signal according to a mode switched by the electronic device The multiplexer circuit includes: a first transistor coupled to a reference voltage, wherein the multiplexer circuit includes a first transistor coupled to a reference voltage, wherein the multiplexer circuit is coupled to the multiplexer circuit The control end is coupled to the first bit of the control signal; the second end of the second transistor is coupled to the second end of the first transistor, and the control end is coupled to the control a second bit of the signal, the second end of which is coupled to one of the sensing electrodes; a third transistor having a first end coupled to the reference voltage and a control terminal The second terminal coupled to the control signal is coupled to the third sensing electrode of the sensing electrodes; the fourth transistor is coupled to the reference voltage at a first end thereof The control terminal is coupled to the second bit of the control signal; a fifth transistor has a first end coupled to the reference voltage, and a control end coupled to the first of the control signal a second end of the bit is coupled to one of the sensing electrodes and a second sensing electrode; and a sixth The first end is coupled to the reference voltage, the control end is coupled to the first bit of the control signal, and the second end is coupled to one of the sensing electrodes. The first transistor, the second transistor, the third transistor, and the sixth transistor system are N-type transistors, and the fourth transistor and the fifth transistor system are P-type transistors . The detecting method of claim 7, wherein the manner of outputting the corresponding control signal according to the mode switched by the electronic device to control output of the driving signal to the sensing electrodes comprises: When the electronic device is in the touch sensing mode, the control circuit sends the control signal to a multiplex circuit to allow the multiplex circuit to output the driving signal to the corresponding sensing electrodes in a time-sharing manner; and when the electronic device is The proximity sensing mode uses the control circuit to send the control signal to the multiplex circuit to connect at least three of the sensing electrodes in parallel, and causes the multiplex circuit to output the driving signal to the sensing electrodes connected in parallel. The method of detecting the method of claim 7, further comprising: when the electronic device is in the touch sensing mode, the sensing electrodes sense a touch action on the touch panel to output a corresponding a touch signal; and when the electronic device is in the proximity sensing mode, the sensing electrodes sense an object moving motion of the touch panel to output a corresponding sensing signal. The detecting method of claim 7, wherein the sensing electrodes are a plurality of sensing buttons. The detecting method of claim 7, wherein each of the sensing electrodes is composed of a plurality of inductors connected in series.