TW201740253A - Touch sensing device - Google Patents

Abstract

The invention provides a touch sensing device. The touch sensing device includes a sensing circuit, a charging and discharging circuit, and a processor. The sensing circuit includes a plurality of sensing pads, which are spaced apart from each other and not connected, and forming a capacitor between each of the sensing pad and the ground. The charging and discharging circuit electrically connects to each of the capacitor. Each of the capacitor is charged and discharged by the charging and discharging circuit. The processor compares a charging and discharging time of each capacitor and a predetermined time to generate a touching signal.

Description

Touch sensing device

The present invention relates to a sensing device, and more particularly to a touch sensing device.

Touch circuits have been widely used in many electronic devices, such as touch screens of electronic devices. Touch screens can detect touch input, and users can touch touches by using fingers, stylus or other objects. The screen performs various functions of the electronic device. In some electronic devices, touch circuits have even replaced keyboards and mice as a new generation of input devices.

In the conventional touch detection technology, for example, the wave touch detection technology, the touch detection principle transmits a high frequency electromagnetic wave signal in real time through a transmitter, and the electromagnetic wave signal is received by a receiver. And detecting whether the frequency of the electromagnetic wave signal is attenuated to detect the touch input. However, the wave-type touch detection technology is mainly realized by high inductance capacitance, which causes the touch circuit to have high energy consumption and high cost.

In view of this, the present invention provides a touch sensing device.

In some embodiments, the touch sensing device includes a sensing circuit, a charge and discharge circuit, and a processing unit. The sensing circuit has a plurality of sensing pads spaced apart from each other without being connected, and a capacitance is formed between each sensing pad and a ground; the charging and discharging circuit is electrically connected to each capacitor, and the charging and discharging circuit is used for each The capacitor is charged and discharged; the processing unit is configured to calculate a charge and discharge time of each capacitor, and the processing unit compares whether each charge and discharge time is greater than a reference time to generate a touch signal.

In some embodiments, the touch sensing device further includes a housing, and the surface of the housing is formed with at least one card slot, and each of the card slots accommodates the sensing circuit.

In some embodiments, the touch sensing device further includes at least one card, and one surface of each card is formed with a conductive pattern, and each card can be disposed in each card slot, and at least one card is disposed in at least one The card slot, the conductive pattern shields at least one of the sensing pads.

In some embodiments, the foregoing conductive pattern may be made of conductive carbon ink; or the conductive pattern may also be made of a metal material.

In some embodiments, the sensing circuit further includes a test pad for electrically connecting to the ground.

In some embodiments, the sensing circuit further includes a test pad, another capacitance is formed between the test pad and the ground, the test pad receives a reference signal, and the processing unit calculates a charge and discharge time of the other capacitor as a reference time. The logic level of the reference signal is a low logic level or a high logic level.

In some embodiments, the foregoing charging and discharging circuit charges and discharges each capacitor in real time and sequentially. The processing unit includes a counter that sequentially counts one charge and discharge cycle of each capacitor to calculate a charge and discharge time.

In some embodiments, the charging and discharging circuit includes a first current source, a second current source, a control circuit, and a switching circuit. The processing unit is electrically connected to the switching circuit, and the switching circuit is electrically connected to the first current source. And between each capacitor, and the switch circuit is electrically connected between the second current source and each capacitor. Moreover, the first current source is electrically connected between the switch circuit and a power supply end, and the second current source is electrically connected between the switch circuit and the ground.

In some embodiments, the touch sensing device further includes an audio and video playback circuit and a database. The audio and video playback circuit searches the database according to the touch signal to play an audio and video signal corresponding to the touch signal.

In summary, according to an embodiment of the touch sensing device of the present invention, the capacitance between the sensing pad and the ground is detected by detecting the change of the charging and discharging time before and after the sensing pad is touched. Touching the input to reduce the energy consumption of the touch sensing device to achieve energy saving and carbon reduction in response to the green energy industry. In addition, the production cost of the touch sensing device is further reduced.

1 is a block diagram of an embodiment of a touch sensing device according to the present invention. A touch sensing device is disclosed, including a sensing circuit 11, a charging and discharging circuit 12, and a processing unit 13. The charge and discharge circuit 12 is electrically connected between the sensing circuit 11 and the processing unit 13.

The sensing circuit 11 includes at least one sensing pad, and the sensing circuit 11 shown in FIG. 1 includes eight sensing pads 111-118. However, the present invention is not limited thereto, and the number of sensing pads can be determined according to circuit design requirements. Increase or decrease. The eight sensing pads 111-118 are spaced apart from each other without being connected, that is, the sensing pads 111-118 are independent. Capacitors 21-28 are formed between the sensing pads 111-118 and the ground respectively, and the capacitance values of the capacitors 21-28 differ depending on whether the sensing pads 111-118 are touched. In detail, when the sensing pads 111-118 are touched, the capacitance values of the corresponding capacitors 21-28 respectively rise. For example, when the sensing pad 115 is touched, the sensing pad 115 and the grounding end The capacitance value of the capacitor 25 rises; when the sensing pad 118 is touched, the capacitance value of the capacitor 28 between the sensing pad 118 and the ground terminal rises; when the sensing pads 111, 117 are touched, the sense The capacitance values of the capacitors 21, 27 between the pads 111, 117 and the ground terminal rise, and the rest are analogous. In some implementations, the capacitors 21-28 can be parasitic capacitances or additional physical capacitors.

The charge and discharge circuit 12 and the processing unit 13 can detect whether the capacitance value of the capacitor 21-28 changes. The charge and discharge circuit 12 charges and discharges the capacitors 21-28 in a real-time manner, the processing unit 13 calculates the charge and discharge times of the capacitors 21-28, and the processing unit 13 compares the charge and discharge times of each of the capacitors 21-28. Whether it is greater than a reference time to determine whether the capacitance value of the capacitor 21-28 changes, thereby determining whether each of the sensing pads 111-118 is touched. For example, when the processing unit 13 calculates that the charging and discharging time of the capacitor 28 is greater than the reference time, and the charging and discharging time of the capacitors 21-27 is less than or equal to the reference time, the processing unit 13 determines that the sensing pad 118 is touched. The sensing pads 111-117 are not touched; or, when the processing unit 13 calculates that the charging and discharging time of the capacitors 28, 26 is greater than the reference time, and the charging and discharging time of the capacitors 21-25, 27 is less than or equal to the reference time, the processing The unit 13 determines that the sensing pads 118, 116 are touched and the sensing pads 111-115, 117 are not touched, and the rest are not repeated; therefore, the processing unit 13 generates a touch signal to indicate One, two, three or even four of the sensing pads 111-118 are touched, that is, the touch combination of the sensing pads 111-118.

In some implementations, the touch sensing device can generate the aforementioned reference time after powering up its power source. In detail, the touch sensing device has a calibration program and a sensing program. The touch sensing device enters the calibration process after the power is turned on, and the processing unit 13 can generate the reference time according to the charging and discharging time of the capacitor 21-28, for example, the average charging and discharging time of the capacitor 21-28 plus an error. range. After the reference time is generated, the touch sensing device enters the sensing procedure. In the sensing program. The processing unit 13 compares the reference time generated in the verification procedure with the charge and discharge times of the capacitors 21-28 to generate a touch signal.

In some embodiments, the charge and discharge circuit 12 sequentially charges and discharges the capacitors 21-28, and the charge and discharge circuit 12 charges and discharges the capacitors 21-28 in an uninterrupted manner. That is to say, the charging and discharging circuit 12 can charge and discharge the capacitors 21-28 at different time points. For example, the charge and discharge circuit 12 can charge and discharge the capacitors 21-28 in an uninterrupted manner in accordance with the order of the capacitors 21, 22, 23, 24, 25, 26, 27, and 28. Here, the processing unit 13 can calculate the total number of charge and discharge times of the capacitors 21-28 for a fixed time to represent the charge and discharge time of the capacitors 21-28 to generate a touch signal. For example, taking a fixed time of 1 ms as an example, assume that the number of charge and discharge times of the reference time is 500 times. In 1 ms, if the capacitor 21 is charged and discharged 519 times, the capacitor 22 is charged and discharged 515 times. In this case, The charging and discharging times of the capacitors 21 and 22 are all smaller than the reference time. That is to say, the touch signal generated by the processing unit 13 indicates that the sensing pads 111 and 112 are not touched.

The charge and discharge circuit 12 can include a first current source 121, a second current source 122, and a switch circuit 123. The switch circuit 123 is electrically connected to the processing unit 13 , and the switch circuit 123 is electrically connected between the first current source 121 and the capacitor 21-28 and electrically connected between the second current source 122 and the capacitor 21-28. The first current source 121 is electrically connected between the power supply terminal and the switch circuit 123, and the second current source 122 is electrically connected between the ground terminal and the switch circuit 123. The switch circuit 123 is used to establish a charging path between the power supply terminal, the first current source 121 and any one of the capacitors 21-28, or establish a ground terminal, a second current source 122 and any one of the capacitors 21-28. The discharge path between. When the switch circuit 123 is switched to be connected between the first current source 121 and the capacitor 21-28, the power supply terminal charges the capacitor 21-28 via the first current source 121; when the switch circuit 123 is switched, the second current source 122 is turned on. Between capacitors 21-28, capacitors 21-28 discharge the ground via a second current source 122.

Accordingly, the processing unit 13 can control the conduction state of the switching circuit 123 to calculate the charging and discharging time of the capacitor 21-28, and the processing unit 13 can calculate the average or sum of the charging time and the discharging time of the capacitor 21-28 as the charging and discharging. time. 2 is a schematic diagram showing the change of the voltage across the capacitor 21 during the charging and discharging process. Referring to FIG. 2, the sensing pad 111 is taken as an example, and the average value of the two intervals t1 and t2 indicates that the reference time of the charging and discharging of the capacitor 21 is For example, the interval t3 indicates the charging time of the capacitor 21 after the sensing pad 111 is touched, and the interval t4 indicates the discharging time of the capacitor 21 after the sensing pad 111 is touched. The processing unit 13 counts the clock cycle of the interval t3 to generate a count value as the charging time, and the processing unit 13 counts the clock period of the interval t4 to generate another count value as the discharge time. Next, the processing unit 13 calculates an average of the aforementioned two count values to generate a charge and discharge time of the capacitor 21. Finally, the processing unit 13 compares the charge and discharge time of the capacitor 21 with the aforementioned reference time and generates a comparison signal to indicate whether the sensing pad 111 is touched. In addition, as is apparent from FIG. 2, the charging time and the discharging time of the capacitor 21 are increased after the sensing pad 111 is touched. After the sensing pads 111-118 are discharged at least once, the processing unit 13 generates a touch signal according to the eight comparison signals.

In practice, the processing unit 13 can be implemented by a microcontroller, a central processing unit, a microprocessor, or an application specific integrated circuit (ASIC) having a counting function, an arithmetic function, and a comparison function. The switch circuit 123 can be implemented in a plurality of switches.

In some embodiments, as shown in FIG. 1 , the touch sensing device further includes a database 15 and a video playback circuit 14 , and the audio and video playback circuit 14 is electrically connected to the processing unit 13 and the data library 15 . The video playback circuit 14 can be a light-emitting circuit, an audio circuit, an image circuit or a combination of the foregoing items. The audio-visual playback circuit 14 receives the touch signal to generate a corresponding video signal according to the touch signal search database 15. For example, taking the lighting circuit as an example, the video playback circuit 14 can generate a corresponding blinking pattern according to the touch signal. Alternatively, taking the audio circuit as an example, the video playback circuit 14 can generate corresponding audio according to the touch signal. Alternatively, taking the image circuit as an example, the video playback circuit 14 can generate a corresponding image according to the touch signal.

3 is a schematic view of another embodiment of a touch sensing device according to the present invention, and FIGS. 4 and 5 are schematic views respectively showing an embodiment of the touch sensing device of FIG. Referring to FIG. 3, the touch sensing device further includes a casing 30, and the surface of the casing 30 is formed with at least one card slot. The surface of the housing 30 of FIG. 3 includes five card slots 31-35. However, the present invention is not limited thereto, and the number of the card slots 31-35 may be increased or decreased according to circuit design requirements. The card slot 31-35 houses the sensing circuit 11, and the charging and discharging circuit 12, the processing unit 13, and the video playback circuit 14 can be disposed in the surface of the housing 30 or in the housing 30.

Moreover, the touch sensing device further includes at least one card corresponding to the card slot 31-35. As shown in FIG. 3, FIG. 3 illustrates five cards 41-45, and each card 41-45 can be separately disposed in the card slot. 31-35. Furthermore, a surface of one of the cards 41-45 is formed with a conductive pattern. When at least one of the cards 41-45 is disposed in the card slot 31-35, the conductive pattern on the surface of the card 41-45 shields the sensing pad 111-118. At least one of the conductive patterns, that is, the conductive pattern can mask one, two, three, or even more than four of the sensing pads 111-118 to form a plurality of masking combinations. The processing unit 13 generates a corresponding touch signal according to the sensing pad (ie, the touch combination) that is shielded by the conductive pattern.

In some implementations, the conductive pattern of each of the cards 41-45 can correspond to a letter, a pattern, or a combination of the foregoing. Referring to FIG. 4, it is assumed that the conductive pattern of the card 41 (hereinafter referred to as the first conductive pattern for convenience of description) corresponds to the English letter "B", and the first conductive pattern shields the sensing pad 117 when the card 41 is disposed in the card slot. In any of the 31-35, for example, the card slot 31, the processing unit 13 determines that the sensing pad 117 is shielded after each of the capacitors 21-28 is charged and discharged, and the touch signal output by the processing unit 13 can be corresponding to The English letter "B" causes the video playback circuit 14 to search the database 15 for the touch signal to play the pronunciation of the English letter "B". Furthermore, if the conductive pattern of the card 42 (hereinafter referred to as a second conductive pattern for convenience of description) corresponds to the English letter "E", and the second conductive pattern shields the sensing pads 113, 116, when the card 42 is disposed in the card slot In any of 31-35, for example, the card slot 32, the processing unit 13 determines that the sensing pads 113, 116 are shielded after each of the capacitors 21-28 is charged and discharged once. At this time, the touch signal output by the processing unit 13 can correspond to The English letter "E" is used to cause the video playback circuit 14 to search the database 15 and play the pronunciation of the English letter "E".

Furthermore, as shown in FIG. 1, the sensing circuit 11 further includes a test pad 119. The test pad 119 can be connected to the ground. When the card 41-45 accommodates the card slot 31-35, the test pad 119 provides the capacitor 21-28 to ground. This can improve the accuracy of the processing unit 13 to calculate the charge and discharge time of the capacitor 21-28. degree. Moreover, in other implementations, the test pad 119 can be electrically connected to one of the general-purpose input/output (GPIO) output pins, and the test pad 119 is also formed between the ground and the ground. A capacitor. The test pad 119 receives a reference signal from the output pin, and the reference signal can be a logic "1" or a logic "0". As such, the test pad 119 can serve as a reference for sensing whether the pads 111-118 are shaded. For example, taking the reference signal in the test pad 119 of the card slot 35 as an example, the processing unit 13 can compare the charge and discharge time of the capacitor connected to the test pad 119 with the charge and discharge time of the capacitor 21-28 to detect the card. Whether the 41-45 is accommodated in the card slot 35; and, the processing unit 13 can compare the charge and discharge time of the capacitor connected to the test pad 119 with the charge and discharge time of the capacitors 21-28 in the other card slots 31-34 to detect Whether the cards 41-45 are accommodated in the card slots 31-34.

In practice, the touch signal can be a digital signal, and the number of bits can be arbitrarily selected according to the actual application. Taking the conductive pattern corresponding to the English alphabet as an example, in order to cover 26 English letters, the number of bits of the touch signal can be 5, and one of the 32 combinations can be selected to correspond to an English letter. For example, the touch signal corresponding to the English letter "A" may be 00001, the touch signal corresponding to the English letter "B" may be 00010, and the digital signal corresponding to the English letter "E" may be 00101.

Furthermore, when the plurality of cards in the cards 41-45 are disposed in the card slots 31-35, please refer to FIG. 5. The three cards 41-43 are respectively disposed in the card slots 31-33, and the surface of the cards 41-43 is three. The conductive patterns correspond to the letters "B", "E", and "E" respectively. At this time, the processing unit 13 determines that the three conductive patterns are respectively determined according to the touch combinations of the sensing pads accommodated in each of the card slots 31-35. Corresponding to the letters "B", "E", and "E", at this time, the processing unit 13 outputs a touch signal corresponding to the English word "BEE", for example, 11101, so that the video playback circuit 14 searches the database 15 and plays the English. The pronunciation of the word "BEE".

In some embodiments, the conductive pattern formed on the surface of each of the cards 41-45 may be made of conductive carbon ink; or the conductive pattern may be made of a metal material such as gold, silver, copper, iron, or the like.

In summary, according to an embodiment of the touch sensing device of the present invention, the capacitance between the sensing pad and the ground is detected by detecting the change of the charging and discharging time before and after the sensing pad is touched. Touching the input to reduce the energy consumption of the touch sensing device to achieve energy saving and carbon reduction in response to the green energy industry. In addition, the production cost of the touch sensing device is further reduced.

While the present invention has been described above in the foregoing embodiments, it is not intended to limit the scope of the invention, and the invention may be modified and modified without departing from the spirit and scope of the invention. Therefore, the scope of patent protection of the present invention is defined by the scope of the claims appended hereto.

11‧‧‧Sensor circuit
111-118‧‧‧Sense pad
119‧‧‧ test pad
12‧‧‧Charge and discharge circuit
121‧‧‧First current source
122‧‧‧second current source
123‧‧‧Switch circuit
13‧‧‧Processing unit
14‧‧‧Video playback circuit
15‧‧‧Database
21-28‧‧‧ Capacitance
30‧‧‧Shell
31-35‧‧‧ card slot
41-45‧‧‧ card
T1, t2, t3, t4‧‧

FIG. 1 is a block diagram showing an embodiment of a touch sensing device according to the present invention. [Fig. 2] is a schematic diagram showing the change of the voltage across the capacitor of Fig. 1 over time during charging and discharging. FIG. 3 is a schematic view of another embodiment of a touch sensing device according to the present invention. FIG. 4 is a schematic view showing an embodiment of the touch sensing device illustrated in FIG. 3. FIG. FIG. 5 is a schematic view of another embodiment of the touch sensing device illustrated in FIG. 3 .

11‧‧‧Sensor circuit

111-118‧‧‧Sense pad

119‧‧‧ test pad

12‧‧‧Charge and discharge circuit

121‧‧‧First current source

122‧‧‧second current source

123‧‧‧Switch circuit

13‧‧‧Processing unit

14‧‧‧Video playback circuit

15‧‧‧Database

21-28‧‧‧ Capacitance

Claims (9)

A touch sensing device comprises: a sensing circuit having a plurality of sensing pads spaced apart from each other without being connected, each of the sensing pads and a grounding end forming a capacitance; a charging and discharging circuit, electrical Connecting each of the capacitors, the charge and discharge circuit is for charging and discharging the capacitor; and a processing unit for calculating a charge and discharge time of each of the capacitors, the processing unit comparing whether each of the charge and discharge times is greater than one Reference time to generate a touch signal. The touch sensing device of claim 1, further comprising a casing, the surface of the casing being formed with at least one card slot, each of the card slots receiving the sensing circuit. The touch sensing device of claim 2, further comprising at least one card, each of the cards having a conductive pattern formed on a surface thereof, and each of the cards is disposed in each of the card slots, and at least one of the cards And disposed in at least one of the card slots, the conductive pattern shielding at least one of the sensing pads. The touch sensing device of claim 3, wherein the conductive pattern is made of a conductive carbon ink or a metal material. The touch sensing device of claim 1 or 3, wherein the sensing circuit further comprises a test pad for electrically connecting the ground. The touch sensing device of claim 1 or 3, wherein the sensing circuit further comprises a test pad, another capacitance is formed between the test pad and the ground, the test pad receives a reference signal, and the processing The unit calculates the charge and discharge time of the other capacitor as the reference time, wherein the logic level of the reference signal is a low logic level or a high logic level. The touch sensing device of claim 1 or 3, wherein the charging and discharging circuit charges and discharges each of the capacitors in real time and sequentially, and the processing unit sequentially counts one of the charging and discharging cycles of each of the capacitors. Calculate the charge and discharge time. The touch sensing device of claim 1 or 3, wherein the charging and discharging circuit comprises a first current source, a second current source and a switching circuit, the processing unit is electrically connected to the switching circuit, the switching circuit Electrically connected between the first current source and each of the capacitors, and the switch circuit is electrically connected between the second current source and each of the capacitors, the first current source is electrically connected to the switch circuit And a power supply terminal, and the second current source is electrically connected between the switch circuit and the ground. The touch sensing device of claim 1 or 3, further comprising a video playback circuit and a database, the video playback circuit searching the database according to the touch signal to play one of the touch signals Audio and video signals.