CN101739185A - Capacitive touch device and method thereof - Google Patents

Abstract

The present invention is a capacitive touch device and a method thereof. The capacitive touch device comprises a signal generator and a signal processor. The signal generator can provide at least one test signal to a capacitive sensor, so that the capacitive sensor responds with at least one response signal after receiving the test signal. The signal processor can analyze the electric field change of the capacitive sensor according to the response signal.

Description

Capacitive touch device and method thereof

technical field

The present invention relates to a sensing device, and in particular to a capacitive touch device.

Background technique

Touch screens are used in a wide range of applications, such as automated teller machines, point-of-sale terminals, industrial control systems, and more. The market continues to grow because of the interface's ease of use, durability, and low cost.

Touch screens can be classified into three types according to their physical principles for detecting touch points: resistive screens, capacitive screens, and wave screens. Resistive screens that generate voltage when lightly pressed with a finger or other contact. With a capacitive screen, your finger draws a small amount of current (commonly used in laptop trackpads). As for the third type of undulating screen, the entire surface is covered with sound waves or infrared rays, and the standing wave pattern is blocked by a finger or tactile tip.

Capacitive touch products are favored by consumers for their advantages of dustproof, fireproof, scratchproof, durable and high resolution. The capacitive touch products currently on the market all use the charging and discharging time or variation to detect capacitance changes in their sensing methods, but it is impossible to distinguish small changes in proximity sensing. In other words, when the charged object does not touch the capacitive touch product, the general capacitive touch product cannot sense.

In view of this, the industry is eagerly looking forward to a new capacitive touch device, which can be used to sense lower sensing capacitance and even sense charged objects in space.

Contents of the invention

The purpose of the present invention is to provide a capacitive touch device, which can achieve the effect of sensing a charged object through space.

A capacitive touch device according to one aspect of the present invention includes a signal generator and a signal processor. The signal generator can provide at least one test signal to a capacitive sensor, so that the capacitive sensor responds to at least one response signal after receiving the test signal. The signal processor can analyze the electric field change of the capacitive sensor according to the response signal.

Thus, according to the effect of capacitive coupling, when the charged object approaches the capacitive sensor, the electric field of the capacitive sensor will change. The proximity sensing device of this embodiment can be used to analyze the electric field change of the capacitive sensor, so as to sense the information that the charged object approaches the capacitive sensor.

Another object of the present invention is to provide a capacitive touch method, which can sense a lower inductive capacitance and even achieve the effect of inducting charged objects in space.

A capacitive touch method according to another aspect of the present invention includes the following steps:

(1) providing at least one test signal to a capacitive sensor, so that the capacitive sensor responds to at least one response signal after receiving the test signal; and

(2) Analyze the electric field change of the capacitive sensor according to the response signal.

Thus, according to the effect of capacitive coupling, when the charged object approaches the capacitive sensor, the electric field of the capacitive sensor will change. The proximity sensing method of the present invention can be used to analyze the electric field change of the capacitive sensor, so as to sense the information of the charged object approaching the capacitive sensor.

Description of drawings

The above-mentioned solution of the present invention will be described below in detail with various embodiments of the accompanying drawings, so that the purpose, characteristics and advantages of the present invention have a further understanding, wherein:

FIG. 1 is a functional block diagram of a proximity sensing device according to an embodiment of the invention.

FIG. 2 is a functional block diagram of a proximity sensing device according to another embodiment of the invention.

FIG. 3 is a flowchart of a proximity sensing method according to an embodiment of the invention.

FIG. 4 is another flowchart of a proximity sensing method according to an embodiment of the invention.

FIG. 5 is another flowchart of a proximity sensing method according to an embodiment of the present invention.

Detailed ways

In order to make the description of the present invention more detailed and complete, reference may be made to the drawings and various embodiments described below, and the same reference numerals in the drawings represent the same or similar elements. On the other hand, well-known elements and steps have not been described in the embodiments in order to avoid unnecessary limitations of the invention.

The technical aspect of the present invention is a capacitive touch device, which can be applied to a capacitive touch screen, or widely used in touch technology. It is worth mentioning that the touch device of this technical aspect can sense a lower inductive capacitance and even achieve the effect of inducting charged objects in space. The specific implementation of the touch device will be described below with reference to FIGS. 1-2 .

Please refer to FIG. 1 . FIG. 1 is a functional block diagram of a capacitive touch device 100 according to an embodiment of the present invention. As shown in the figure, the proximity sensing device 100 includes a signal generator 110 and a signal processor 120 .

In this embodiment, the signal generator 110 can provide at least one test signal to the capacitive sensor 190, so that the capacitive sensor 190 responds to at least one response signal after receiving the test signal. The signal processor 120 can analyze the change of the electric field of the capacitive sensor 190 according to the response signal.

Thus, according to the effect of capacitive coupling, when a charged object (such as a finger) approaches the capacitive sensor 190 , the electric field of the capacitive sensor 190 will change. The capacitive touch device 100 can be used to analyze the change of the electric field of the capacitive sensor 190 so as to sense the information that the charged object approaches the capacitive sensor 190 .

In the initial state of the capacitive touch device 100 , a “trigger voltage” scan can be performed on the capacitive sensor 190 . For a further description of the scan trigger voltage, please continue to refer to FIG. 1 . As shown in the figure, the capacitive touch device 100 may further include a counter 130 , a detector 140 , an adjuster 150 and a setter 160 .

In this embodiment, the counter 130 can count the number of test signals. The detector 140 can detect the number of response signals. The regulator 150 can reduce the voltage of the test signal when the quantity of the response signal is equal to the quantity of the test signal. The setter 160 may preset the voltage of the test signal as the trigger voltage when the quantity of the response signal is less than the quantity of the test signal.

After the trigger voltage is determined, the capacitive sensor 190 can be detected periodically or irregularly. If multiple pulse waves are sent to the capacitive sensor 190, they are used as multiple test signals. According to the effect of capacitive coupling, if the charged object approaches the capacitive sensor 190 , a coupling capacitance will be generated between the charged object and the capacitive sensor 190 . This causes the electric field of the capacitive sensor 190 to change, thereby changing the charging and discharging trigger times of the capacitive sensor 190 . Among the plurality of response signals responded by the capacitive sensor 190 according to the plurality of test signals, the voltage of some response signals decreases. Moreover, since the capacitance is inversely proportional to the distance, when the charged object is closer to the capacitive sensor 190 , the coupling capacitance between the charged object and the capacitive sensor 190 is more significant, resulting in more response signals whose voltage drops.

In view of this, please continue to refer to Figure 1. As shown, the signal generator 110 may include a PWM module 112 . In addition, the signal processor 120 may include a detection module 121 , a calculation module 122 and a quantity analysis module 123 .

In this embodiment, the WWM module 112 can generate at least one pulse wave as a test signal, wherein the voltage of the test signal is higher than the trigger voltage. Next, the capacitive sensor 190 responds to at least one response signal after receiving the test signal. Next, the detection module 121 can detect a response signal whose voltage is higher than the trigger voltage as a sampling signal. The calculation module 122 can count the number of sampled signals. The quantity analysis module 123 can analyze the change of the electric field of the capacitive sensor 190 according to the quantity of the sampled signal.

In this way, the WWM module 112 can send a plurality of pulse waves to the capacitive sensor 190 as a plurality of test signals. If the charged object is closer to the capacitive sensor 190 , the number of sampled signals counted by the calculation module 122 is smaller. The quantity analysis module 123 can analyze the distance between the charged object and the capacitive sensor 190 according to the quantity of the sampled signal.

In addition, the voltage of the pulse wave generated by the WWM module 112 should be higher than the trigger voltage. Moreover, the closer the voltage of the pulse wave is to the trigger voltage, the higher the sensitivity of the capacitive touch device 100 is. In other words, if the voltage of the pulse wave is slightly higher than the trigger voltage, when the charged object approaches the capacitive sensor 190 , the voltage of the response signal released by the capacitive sensor 190 is more likely to be lower than the trigger voltage. Therefore, the number of sampled signals counted by the computing module 122 is significantly reduced. The quantity analysis module 123 can analyze the change of the electric field of the capacitive sensor 190 according to the quantity of the sampled signal.

Please refer to FIG. 2 , which is a functional block diagram of a capacitive touch device 200 according to another embodiment of the present invention. As shown in the figure, the capacitive touch device 200 includes a signal generator 210 and a signal processor 220 .

In this embodiment, the signal generator 210 can provide at least one test signal to the capacitive sensor 190, so that the capacitive sensor 190 responds to at least one response signal after receiving the test signal. The signal processor 220 can analyze the change of the electric field of the capacitive sensor 190 according to the response signal.

Thus, according to the effect of capacitive coupling, when a charged object (such as a finger) approaches the capacitive sensor 190 , the electric field of the capacitive sensor 190 will change. The capacitive touch device 200 can be used to analyze the change of the electric field of the capacitive sensor 190 so as to obtain information that an object with static electricity approaches the capacitive sensor 190 .

If a sine wave is sent to the capacitive sensor 190, it is used as a test signal. According to the effect of capacitive coupling, when the charged object approaches the capacitive sensor 190 , a coupling capacitance will be generated between the charged object and the capacitive sensor 190 . This causes the electric field of the capacitive sensor 190 to change, thereby changing the charging and discharging trigger times of the capacitive sensor 190 . This reduces the intensity of the response signal released by the capacitive sensor 190 . Moreover, since the capacitance is inversely proportional to the distance, when the charged object is closer to the capacitive sensor 190 , the coupling capacitance between the charged object and the capacitive sensor 190 becomes more significant, resulting in lower strength of the response signal.

In view of this, please continue to refer to Figure 2. As shown in the figure, the signal generator 210 may include a sine wave modulation module 212 . In addition, the signal processor 220 may include an intensity measurement module 222 and an intensity analysis module 224 .

In this embodiment, the sine wave modulation module 212 can generate a sine wave as a test signal. Next, the strength measurement module 222 can measure the strength of the response signal. The intensity analysis module 224 can analyze the electric field change of the capacitive sensor according to the intensity of the response signal.

In this way, the capacitive touch device 200 can analyze the distance between the charged object and the capacitive sensor according to the intensity of the response signal.

On the other hand, if a sine wave is sent to the capacitive sensor 190 as a test signal. According to the effect of capacitive coupling, when the charged object approaches the capacitive sensor 190 , a coupling capacitance will be generated between the charged object and the capacitive sensor 190 . This causes the electric field of the capacitive sensor 190 to change, thereby changing the charging and discharging trigger times of the capacitive sensor 190 . The frequency of the response signal released by the capacitive sensor 190 is changed. Moreover, since the capacitance is inversely proportional to the distance, when the charged object is closer to the capacitive sensor 190 , the coupling capacitance between the charged object and the capacitive sensor 190 becomes more significant, resulting in a greater change in the frequency of the response signal.

In view of this, please continue to refer to Figure 2. As shown in the figure, the signal processor 220 may include a frequency measurement module 226 and a frequency analysis module 228 .

In this embodiment, the sine wave modulation module 212 can generate a sine wave as a test signal. Next, the frequency measurement module 226 can measure the frequency of the response signal. The frequency analysis module 228 can analyze the electric field variation of the capacitive sensor according to the frequency of the response signal.

In this way, the capacitive touch device 200 can analyze the distance between the charged object and the capacitive sensor according to the frequency change of the response signal.

The technical aspect of the present invention is a proximity sensing method, which can be applied to capacitive touch screens, or widely used in touch technology. It is worth mentioning that the touch method of this technical aspect can achieve the purpose of sensing a charged object through space. The specific implementation of the touch device will be described below with reference to FIGS. 3-5 .

Please refer to FIG. 3 . FIG. 3 is a flowchart of a capacitive touch method 300 according to an embodiment of the present invention. As shown in the figure, the capacitive touch method 300 includes the following steps 310 to 320 (it should be understood that the steps mentioned in this embodiment can be adjusted according to actual needs unless the order is specifically stated. sequentially, even concurrently or partially concurrently).

Step 310: Provide at least one test signal to a capacitive sensor, so that the capacitive sensor responds to at least one response signal after receiving the test signal.

Step 320: Analyze the electric field variation of the capacitive sensor according to the response signal.

Thus, according to the effect of capacitive coupling, when a charged object (such as a finger) approaches the capacitive sensor, the electric field of the capacitive sensor will change. The capacitive touch method 300 can be used to analyze the electric field change of the capacitive sensor, so as to sense the information of the charged object approaching the capacitive sensor.

In the initial state, the capacitive touch method 300 can scan the “trigger voltage” for the capacitive sensor 190 . For a further description of the scan trigger voltage, please refer to FIG. 4 . FIG. 4 is another flowchart of a capacitive touch method 300 according to an embodiment of the present invention. As shown in the figure, the capacitive touch method 300 includes the following steps 330 - 360 .

Step 330: Count the number of test signals.

Step 340: Detect the number of response signals.

Step 345: Determine whether the number of response signals is equal to the number of test signals.

Step 350 : Decrease the voltage of the test signal when the quantity of the response signal is equal to the quantity of the test signal.

Step 360: When the number of response signals is less than the number of test signals, preset the voltage of the test signal as the trigger voltage.

After the trigger voltage is determined, the capacitive sensor can be detected periodically or irregularly. It can detect the capacitive sensor periodically or irregularly. If multiple pulse waves are sent to the capacitive sensor, they are used as multiple test signals. According to the effect of capacitive coupling, if the charged object is close to the capacitive sensor, a coupling capacitance will be generated between the charged object and the capacitive sensor. This causes the electric field of the capacitive sensor to change, thereby changing the number of triggers for charging and discharging the capacitive sensor. Among the plurality of response signals responded by the capacitive sensor according to the plurality of test signals, the voltages of some response signals are reduced. Moreover, since the capacitance is inversely proportional to the distance, when the charged object is closer to the capacitive sensor, the coupling capacitance between the charged object and the capacitive sensor becomes more significant, resulting in more response signals whose voltage drops.

In view of this, please continue to refer to FIG. 4 . As shown, step 310 may include sub-step 410 . In addition, step 320 may include sub-step 420 , sub-step 430 and sub-step 440 .

Sub-step 410: Generate at least one pulse wave as a test signal, wherein the voltage of the test signal is higher than the trigger voltage.

Sub-step 420 : Among the response signals, those whose detection voltage is higher than the trigger voltage are used as sampling signals.

Sub-step 430: Count the number of sampled signals.

Sub-step 440: Analyze the electric field variation of the capacitive sensor according to the number of sampled signals.

In this way, in the sub-step 410, a plurality of pulse waves may be sent to the capacitive sensor as a plurality of test signals. If the charged object is closer to the capacitive sensor, the number of sampled signals counted in the sub-step 430 is smaller. Next, in sub-step 440 , the distance between the charged object and the capacitive sensor can be analyzed according to the quantity of the sampled signal.

In addition, the voltage of the pulse wave generated in the sub-step 410 should be higher than the trigger voltage. Moreover, the closer the voltage of the pulse wave is to the trigger voltage, the higher the sensitivity of the capacitive touch method 300 is. In other words, if the voltage of the pulse wave is slightly higher than the trigger voltage, when the charged object approaches the capacitive sensor, the voltage of the response signal released by the capacitive sensor is more likely to be lower than the trigger voltage. Therefore, the number of sampled signals counted in sub-step 430 is significantly reduced. Next, in sub-step 440 , the electric field variation of the capacitive sensor can be analyzed according to the number of sampled signals.

If a sine wave is sent to the capacitive sensor, it is used as a test signal. According to the effect of capacitive coupling, when the charged object approaches the capacitive sensor, a coupling capacitance will be generated between the charged object and the capacitive sensor. This causes the electric field of the capacitive sensor to change, thereby changing the charging and discharging trigger times of the capacitive sensor. The strength of the response signal released by the capacitive sensor is reduced. Moreover, since the capacitance is inversely proportional to the distance, when the charged object is closer to the capacitive sensor, the coupling capacitance between the charged object and the capacitive sensor becomes more significant, resulting in lower strength of the response signal.

In view of this, please refer to FIG. 5 , which is another flowchart of a capacitive touch method 300 according to an embodiment of the present invention. As shown, step 310 may include sub-step 510 . In addition, step 320 may include sub-step 520 and sub-step 530 .

Sub-step 510: Generate a sine wave as a test signal.

Sub-step 520: Measure the strength of the response signal.

Sub-step 530: Analyze the electric field variation of the capacitive sensor according to the strength of the response signal.

In this way, the distance between the charged object and the capacitive sensor can be analyzed according to the intensity of the response signal.

On the other hand, if a sine wave is sent to the capacitive sensor, it is used as a test signal. According to the effect of capacitive coupling, when the charged object approaches the capacitive sensor, a coupling capacitance will be generated between the charged object and the capacitive sensor. This causes the electric field of the capacitive sensor to change, thereby changing the charging and discharging trigger times of the capacitive sensor. The frequency of the response signal released by the capacitive sensor is changed. Moreover, since the capacitance is inversely proportional to the distance, when the charged object is closer to the capacitive sensor, the coupling capacitance between the charged object and the capacitive sensor becomes more significant, resulting in a greater change in the frequency of the response signal.

In view of this, please continue to refer to FIG. 5 . As shown in the figure, step 320 further includes sub-step 540 and sub-step 550 .

Sub-step 540: Measure the frequency of the response signal.

Sub-step 550: Analyze the electric field variation of the capacitive sensor according to the frequency of the response signal.

In this way, the distance between the charged object and the capacitive sensor can be analyzed according to the frequency change of the response signal.

Although the present invention has been disclosed above with embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various equivalent changes or substitutions without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection shall prevail as defined by the appended claims of the application.

Claims (10)

1. A capacitive touch device, comprising: A signal generator for providing at least one test signal to a capacitive sensor, so that the capacitive sensor responds to at least one response signal after receiving the test signal; and A signal processor is used for analyzing the electric field change of the capacitive sensor according to the response signal. 2. The capacitive touch device according to claim 1, further comprising: A counter, used for counting the quantity of the test signal; a detector for detecting the quantity of the response signal; a regulator for reducing the voltage of the test signal when the quantity of the response signal is equal to the quantity of the test signal; and A setter is used to preset the voltage of the test signal as a trigger voltage when the quantity of the response signal is less than the quantity of the test signal. 3. The capacitive touch device according to claim 2, wherein the signal generator comprises: A pulse width modulation module is used to generate at least one pulse wave as the test signal, wherein the voltage of the test signal is higher than the trigger voltage. 4. The capacitive touch device according to claim 3, wherein the signal processor comprises: A detection module, used to detect the response signal whose voltage is higher than the trigger voltage as a sampling signal; a calculating module, used for counting the quantity of the sampled signal; and A quantity analysis module is used for analyzing the electric field variation of the capacitive sensor according to the quantity of the sampled signal. 5. The capacitive touch device according to claim 1, wherein the signal generator includes a sine wave modulation module for generating a sine wave as the test signal, and the signal processor includes an intensity measurement a module for measuring the strength of the response signal; an intensity analysis module for analyzing the electric field change of the capacitive sensor according to the strength of the response signal; a frequency measurement module for measuring the frequency of the response signal; and a The frequency analysis module is used for analyzing the electric field variation of the capacitive sensor according to the frequency of the response signal. 6. A capacitive touch method, comprising: providing at least one test signal to a capacitive sensor, so that the capacitive sensor responds to at least one response signal after receiving the test signal; and According to the response signal, the electric field change of the capacitive sensor is analyzed. 7. The capacitive touch method according to claim 6, further comprising: Count the number of the test signals; detecting the number of response signals; reducing the voltage of the test signal when the quantity of the response signal is equal to the quantity of the test signal; and When the quantity of the response signal is less than the quantity of the test signal, the voltage of the test signal is preset as a trigger voltage. 8. The capacitive touch method according to claim 7, wherein providing the test signal to the capacitive sensor comprises: At least one pulse wave is generated as the test signal, wherein the voltage of the test signal is higher than the trigger voltage. 9. The capacitive touch method according to claim 8, wherein analyzing the electric field change of the capacitive sensor according to the response signal comprises: Among the response signals, the one whose detection voltage is higher than the trigger voltage is used as a sampling signal; counting the number of the sampled signals; and According to the quantity of the sampled signal, the change of the electric field of the capacitive sensor is analyzed. 10. The capacitive touch method according to claim 6, wherein providing the test signal to the capacitive sensor comprises: generating a sine wave as the test signal, and analyzing the capacitive sensor according to the response signal The electric field change includes: measuring the strength of the response signal; analyzing the electric field change of the capacitive sensor according to the strength of the response signal; measuring the frequency of the response signal; and analyzing the electric field of the capacitive sensor according to the frequency of the response signal Variety.

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