TWI783268B - Method of switch debouncing - Google Patents

Abstract

A method of switch debouncing is provided. The method is to detect electronic signals triggered by a contact switch, output a corresponding switch signal when the contact switch is operated, time a threshold time, stop determining whether the contact switch is operated, and recover to determining whether the contact switch is operated after the threshold time elapsed. The present disclosed example can eliminate a delay of triggering switch, and suppress the contact bounce noise.

Description

Method of Suppressing Bounce Noise

The invention relates to suppressing bouncing noise, in particular to a method for suppressing bouncing noise.

Existing switch devices (such as keyboard keys or buttons of electronic devices) mostly trigger electrical signals through the contact of multiple electronic contacts. The above-mentioned triggering method will generate contact bounce noise at the moment of contact of the electronic contact, and the above-mentioned contact bounce noise will cause the switch device to misjudge the state of the button and output a wrong switch signal.

Please refer to FIG. 10 , which is a schematic diagram of monitoring electrical signals of a contact switch in the prior art. As shown in the figure, when the user presses the button (time point T0), the electrical signal of the button will rise to a high potential immediately, and trigger a series of contact bounce noises (that is, the electrical signal between time point T0 and time point T1 ).

Moreover, when the user releases the button (time point T3), the electrical signal of the button will drop to a low potential immediately, and trigger a series of contact bounce noises (that is, the electrical signal between time point T3 and time point T4).

The aforementioned contact bouncing noise will cause the switch device to misjudge that the button is continuously released and pressed in a short period of time, and continuously output the press signal and release signal of the button in a short period of time (that is, the wrong switch signal), causing the user inconvenient.

In order to suppress the above-mentioned contact bouncing noise and avoid outputting wrong switching signals, a technology for suppressing bouncing noise has been proposed.

Specifically, the existing technology for suppressing bouncing noise is to continuously monitor the potential of the electrical signal after the user presses the button (time point T0), and start counting the preset stabilization time ( For example, 4 ms), the pressing signal of the button is output when the electric potential maintains a stable state and reaches the preset stable time (time point T2).

In addition, when the user releases the button (time point T3), the existing bouncing noise suppression technology will also continue to monitor the potential of the electrical signal, and start counting the preset stabilization time when the potential remains stable (time point T4) ( For example, 4 ms), the release signal of the button is output when the electric potential maintains a stable state and reaches the preset stable time (time point T5).

The existing bouncing noise suppression mainly has two deficiencies: "the trigger delay time is too long" and "the trigger delay time is not fixed".

Regarding the trigger delay time being too long, when the user presses/releases the button, the existing technology for suppressing bouncing noise must maintain a stable potential state for a preset stabilization time before outputting the corresponding press/release signal (take Figure 10 as an example, The compression delay is 12ms and the release delay is 11ms).

As for the trigger delay time is not fixed, with the aging of electronic contacts, the duration of the aforementioned contact bounce noise may increase, which makes the existing techniques for suppressing bounce noise have to spend more time waiting for the potential to maintain a stable state, making the trigger Latency increased. In addition, due to the different states of the electronic contacts of different buttons (that is, the duration of contact bounce noise is different), the existing technology for suppressing bounce noise will make the trigger delay time of different buttons different, making it difficult for users to adapt to different buttons. different trigger delays.

In view of this, there is an urgent need for a solution that can solve the above technical problems to be proposed.

The invention provides a method for suppressing the bouncing noise, which can trigger the switch signal immediately and suppress the bouncing noise.

In one embodiment, a method for suppressing bouncing noise is used in a switch device. The switch device includes a contact switch, a processing unit and a transmission unit for connecting to a computer host. The method for suppressing bouncing noise includes the following steps: The unit continuously monitors the electrical signal triggered by the contact switch; when it judges that the contact switch is operated according to the electrical signal, it immediately outputs the switch signal corresponding to the electrical signal through the transmission unit; when the contact switch is operated, the critical time is counted, and Stop judging whether the contact switch is operated again within the critical time; and, after the critical time passes, continue to judge whether the contact switch is operated again according to the electrical signal.

The present invention can eliminate the delay of button triggering and suppress the bouncing noise caused by button triggering, thereby improving user experience.

1: switch device

10: Processing unit

11: Contact switch

12:Transmission unit

13: switch array

14: Circuit board

15: Indication unit

2: Computer host

30: Keycap

31: Axis structure

32: Switch housing

320: upper shell

321: lower shell

33: Reset element

34: The first conductive sheet

35: The second conductive sheet

40: The first conductive sheet

400: first contact

41: The second conductive sheet

410: second contact

42: Barrier film

43: Positioning hole

S10-S16: Monitoring and suppression steps

S20-S22: Manual adjustment steps

S30-S34: Automatic adjustment steps

S0-S3: time point

T0-T5: time point

Fig. 1 is a structural diagram of a switching device according to an embodiment of the present invention; Fig. 2 is a structural diagram of a switching device according to another embodiment of the present invention; Fig. 3 is a bouncing noise suppression method according to a first embodiment of the present invention The flow chart of the method; Fig. 4 is the flow chart of the manual adjustment critical time of the second embodiment of the present invention; Fig. 5 is the flow chart of the automatic adjustment critical time of the third embodiment of the present invention; Fig. 6 is the flow chart of the present invention A schematic diagram of the appearance of a touch switch in an embodiment; FIG. 7A is a schematic cross-sectional view of the touch switch in FIG. 6 in a released state; FIG. 7B is a schematic cross-sectional view of the touch switch in FIG. 6 in a pressed state; A schematic cross-sectional view of a release state of a touch switch according to an embodiment of the invention; 8B is a schematic cross-sectional view of the touch switch of FIG. 8A in a pressed state; FIG. 9 is a schematic diagram of an electrical signal of a monitoring touch switch according to an embodiment of the present invention; Schematic diagram of the number.

The technical solution of the present invention will be described in detail below in conjunction with the drawings and specific examples to further understand the purpose, solution and effect of the present invention, but it is not intended to limit the scope of the patent application attached to the present invention.

First please refer to FIG. 1 , which is a structural diagram of a switch device according to an embodiment of the present invention. As shown in the figure, the present invention proposes a switch device 1 , which mainly includes at least one contact switch 11 , a transmission unit 12 and a processing unit 10 electrically connected to the contact switch 11 and the transmission unit 12 .

The contact switch 11 (such as a toggle switch, button, button or other digital switch) is used to accept user operations (such as pressing or releasing operations), and trigger corresponding electrical signals when receiving user operations (such as changing the electrical signal potential).

The transmission unit 12 is used for wired/wireless connection to an external computer host 2 (such as a mobile device, a notebook computer, a desktop computer, etc.) for signal transmission. Specifically, the transmission unit 12 can be a wireless transmission module (such as a Bluetooth wireless transmission module or an infrared wireless transmission module), and can directly establish a wireless connection with the computer host 2, or via a detachable connection with the computer host 2 The wireless transmitter (dongle) establishes a wireless connection to connect to the host computer 2 . Alternatively, the transmission unit 12 can be detachably connected to the host computer 2 via a transmission line (such as a USB transmission line).

The processing unit 10 is used for controlling the switch device 1 . Specifically, the processing unit 10 continuously monitors whether the contact switch 11 triggers the electrical signal, and when receiving the electrical signal triggered by the contact switch 11, outputs a corresponding off-off signal to the computer host 2 through the transmission unit 12, so as to Make the host computer 2 execute corresponding functions (such as inputting corresponding character symbols).

Please refer to FIG. 2 , which is a structural diagram of a switch device according to another embodiment of the present invention. In this embodiment, the switch device 1 (such as a keyboard) further includes a switch array 13 and a circuit board 14 . The switch array 13 includes a plurality of touch switches 11 (such as a plurality of keys).

Moreover, the processing unit 10 , the transmission unit 12 and the switch array 13 are jointly disposed on the same circuit board 14 , and the processing unit 10 is electrically connected to each contact switch 11 of the transmission unit 12 and the switch array 13 through the circuit board 14 .

In one embodiment, the switch device 1 further includes one or more indicating units 15 (such as light-emitting elements or sound-emitting elements). The indicating unit 15 is used to indicate the state of the switch device 1 (such as lighting or sound when the switch device 1 is connected to the computer host 2) or the state of the corresponding contact switch 11 (such as lighting or sound when the contact switch 11 is ready). , or turn off or beep when pressed).

Please refer to FIG. 6 to FIG. 7B and FIG. 9 together. FIG. 6 is a schematic view of the appearance of a touch switch according to an embodiment of the present invention. FIG. 7A is a schematic cross-sectional view of the release state of the touch switch in FIG. 6 . 7B is a schematic cross-sectional view of the pressed state of the touch switch in FIG. 6 , and FIG. 9 is a schematic diagram of monitoring electrical signals of the touch switch according to an embodiment of the present invention.

In this embodiment, each of the aforementioned touch switches 11 can be a mechanical digital switch, and is electrically connected to the circuit board 14 , and a corresponding indicating unit 15 (LED here) is disposed on the circuit board 14 .

In one embodiment, each touch switch 11 includes a keycap 30 , a shaft structure 31 , a switch case 32 , a first conductive sheet 34 , a second conductive sheet 35 and a reset element 33 . The switch housing 32 may include an upper housing 320 and a lower housing 321 .

The first conductive sheet 34 and the second conductive sheet 35 are electrically connected to the processing unit 10, when the first conductive sheet 34 and the second conductive sheet 35 contact or separate (such as the first conductive sheet 34 and the second conductive sheet 35 are connected to form Loop, or separation to form an open circuit), can trigger electrical signals of different potentials. The axis structure 31 is used to move between the reset position and the trigger position to change the contact state between the first conductive sheet 34 and the second conductive sheet 35 . The reset element 33 is used to provide a restoring force to move the axis structure 31 toward the reset position. The keycap 30 is disposed above the shaft structure 31 for receiving an external force to move the shaft structure 31 toward the trigger position.

In one embodiment, the first conductive sheet 34 and the second conductive sheet 35 are conductive metal sheets, and at least one of the first conductive sheet 34 and the second conductive sheet 35 has flexibility, and can be placed on the shaft When the core structure 31 is pushed, it deforms and changes the contact state between the first conductive sheet 34 and the second conductive sheet 35 , thereby triggering electrical signals of different potentials.

For example, as shown in FIG. 7A, when the user does not press the touch switch 11, the axial structure 31 is simultaneously subjected to the upward restoring force of the reset element 33 and the downward positive force of the upper housing 320, so that the static force is balanced at Reset position. In this state, the first conductive sheet 34 and the second conductive sheet 35 are not connected, so the electrical signal of the touch switch 11 presents a low potential (such as the potential before time point S0 in FIG. 9 ).

As shown in FIG. 7B , the user can press the touch switch 11 to make the keycap 30 move down to the trigger position in conjunction with the shaft structure 31 . At this time, the first conductive sheet 34 is connected to the second conductive sheet 35 , so the electrical signal of the touch switch 11 changes to a high potential (such as the potential between time points S0 - S2 in FIG. 9 ). Moreover, at the moment when the first conductive sheet 34 contacts the second conductive sheet 35 , bouncing noise (such as the noise between time points S0 - S1 in FIG. 9 ) will be generated.

Then, when the user releases the touch switch 11 , the axis structure 31 is simultaneously moved back to the reset position by the upward restoring force of the reset element 33 . In this state, the first conductive sheet 34 and the second conductive sheet 35 are disconnected, and at the moment when the first conductive sheet 34 and the second conductive sheet 35 are disconnected, a bouncing noise (such as time point S2 of FIG. 9 ) will be generated. -Noise between S3).

Please refer to FIG. 8A to FIG. 8B and FIG. 9. FIG. 8A is a schematic cross-sectional view of a touch switch according to an embodiment of the present invention in a released state, and FIG. 8B is a schematic cross-sectional view of the touch switch in FIG. 8A in a pressed state. .

In this embodiment, each of the aforementioned touch switches 11 can be a film-type digital switch. The first conductive sheet 40 and the second conductive sheet 41 are conductive films. A barrier film 42 is laid between the first conductive sheet 40 and the second conductive sheet 41 . The barrier film 42 is used to isolate the first conductive sheet 40 (including the first contact 400 electrically connected to the processing unit 10 ) and the second conductive sheet 41 (including the second contact 410 electrically connected to the processing unit 10 ). A positioning hole 43 vertically aligned with the first contact 400 and the second contact 410 is formed on the barrier film 42 .

As shown in FIG. 8A , when no external force is applied to the keycap 30 , the axis structure 31 is in the reset position, and the first contact 400 and the second contact 410 are not electrically connected. In this state, since the first conductive sheet 40 and the second conductive sheet 41 are not connected, the electrical signal of the touch switch 11 presents a low potential (such as the potential before time point S0 in FIG. 9 ).

Moreover, as shown in FIG. 8B , when an external force is applied to the keycap 30 , the axial structure 31 presses the first conductive sheet 40 , and the first conductive sheet 40 is deformed so that the first contact 400 passes through the positioning hole 43 and contacts the first contact point 400 . The second contact 410 reaches the trigger position. At this moment, the first contact 400 is connected to the second contact 410 , so the electrical signal of the touch switch 11 changes to a high potential (such as the potential between time points S0 - S2 in FIG. 9 ). Moreover, at the moment when the first contact 400 contacts the second contact 410 , bouncing noise (such as the noise between time points S0 - S1 in FIG. 9 ) will be generated.

Then, when the user releases the touch switch 11 , the shaft center structure 31 returns upward to the reset position at the same time. In this state, the first contact 400 and the second contact 410 are disconnected, and at the moment when the first contact 400 and the second contact 410 are disconnected, a bouncing noise will be generated (as shown at time point S2 in FIG. 9 ). -Noise between S3).

Although in the foregoing embodiments, the touch switch 11 triggers a high-potential electrical signal when pressed, and triggers a low-potential electrical signal when released, it is not limited thereto.

In one embodiment, the touch switch 11 can also be modified to trigger an electrical signal of low potential when pressed, and trigger an electrical signal of high potential when released.

Next, how the present invention suppresses the aforementioned bouncing noise will be described in detail. The methods for suppressing bouncing noise in various embodiments of the present invention can be realized by any switch device 1 shown in FIG. 1 , FIG. 2 , FIG. 6 to FIG. 8B .

Please also refer to FIG. 3 , which is a flow chart of the method for suppressing bouncing noise according to the first embodiment of the present invention. Specifically, the method for suppressing bouncing noise in this embodiment includes the following steps.

Step S10: The processing unit 10 continuously monitors the electrical signal triggered by the contact switch 11, such as monitoring the potential of the electrical signal.

Step S11: The processing unit 10 judges whether the touch switch 11 is operated according to the received electric signal, for example, it is determined that the touch switch 11 is operated when the potential of the electric signal changes (time point S0 or S2 as shown in FIG. 9 ).

In one embodiment, the touch switch 11 lowers the potential of the electrical signal from a high level to a low level when the user presses the switch (if it falls below the lower limit of the potential, the lower limit of the potential can be 0.3V); or At When receiving the user's release operation, the potential of the electrical signal is raised from a low level to a high level (if it rises above the upper limit of the potential, the upper limit of the potential can be 0.7V). In this way, the processing unit 10 can determine what kind of operation the touch switch 11 has received according to the potential change of the electrical signal.

If the processing unit 10 determines that the contact switch 11 is operated, step S12 is executed. Otherwise, the processing unit 10 executes step S11 again.

Step S12: The processing unit 10 generates a corresponding switch signal according to the state of the operated contact switch 11 and the electrical signal, and immediately outputs the switch signal through the transmission unit 12 .

For example, if the touch switch 11 is a button of the letter "K", when the processing unit 10 detects that the touch switch 11 is pressed, the output switch signal is used to instruct the computer host 2 to "start inputting K", When it is detected that the contact switch 11 is released, the output switch signal is used to instruct the computer device 2 to "stop input K".

Please refer to FIG. 9 and FIG. 10 at the same time. The present invention directly outputs the switch signal when the contact switch 11 is operated (that is, at time point S0 or S2). (time point T0 or T3), the switching signal must be delayed until time point T2 or T5. Thereby, the present invention can indeed eliminate the delay of key triggering.

It is worth mentioning that, at the same time, before or after sending out the switch signal, the processing unit 10 starts counting the preset critical time.

In one embodiment, the critical time may be 10 ms, any time value not greater than 15 ms, or any time value not less than 10 ms, without limitation.

In one embodiment, the critical time must not be less than the noise time of the bouncing noise, and the aforementioned noise time can be obtained through experimental testing, experience accumulation or statistics.

Step S13: The processing unit 10 stops judging whether the touch switch 11 is operated again within a critical time, that is, suspends monitoring the touch switch 11 . For example, the processing unit 10 can directly ignore the potential change of the electrical signal within the critical time.

As shown in FIG. 9, the processing unit 10 starts counting the critical time (10 ms in this example) at the time point S0 or S2, and ignores the electrical signal within the critical time (that is, ignores the time point S0-S1 or the time point S2-S3 between electrical signal changes).

It is worth mentioning that since the bouncing noise is usually generated during this critical time, the present invention can effectively suppress the bouncing noise by directly ignoring the electrical signal change during this critical time.

Step S14: The processing unit 10 judges whether the critical time has elapsed. If the processing unit 10 determines that the critical time has elapsed, step S15 is executed. Otherwise, the processing unit 10 executes step S14 again.

Step S15: After the critical timing time elapses, the processing unit 10 continues to judge whether the contact switch 11 is operated again according to the electric signal, that is, resumes monitoring the contact switch 11 .

Step S16: The processing unit 10 determines whether to terminate the noise suppression function, for example, the user removes the switch device 1 or manually turns off the noise suppression function.

If the processing unit 10 determines to terminate the noise suppression function, the execution of the method ends. Otherwise, the processing unit 10 executes step S11 again to continuously execute the noise suppression function.

It is worth mentioning that although in the foregoing example, a set of touch switches 11 and the critical time are taken as an example for illustration, it is not limited thereto.

In one embodiment, the bouncing noise suppression method of the present invention can be applied to a plurality of contact switches 11 (eg, to the switch array 13 ). Moreover, the aforementioned plurality of contact switches 11 correspond to a plurality of critical times, and the critical times corresponding to each of the contact switches 11 may be the same or different.

Please refer to FIG. 3 and FIG. 4 together. FIG. 4 is a flow chart of manually adjusting the critical time according to the second embodiment of the present invention. This embodiment further provides a function of manually adjusting the critical time, allowing the user to adjust the aforementioned critical time according to personal preference, so as to achieve the best operating experience.

For example, when the user feels that the current critical time is too short to suppress all bouncing noises (such as the phenomenon of jumping keys on the same key), the critical time can be manually increased; when the user feels that the current critical time is too long (If the same button cannot be operated continuously), the critical time can be manually reduced.

Compared with the method for suppressing bouncing noise shown in FIG. 3 , the method for suppressing bouncing noise in this embodiment further includes the following steps for realizing the function of manually adjusting the critical time.

Step S20: The processing unit 10 switches to the manual adjustment mode according to the user operation. In one embodiment, the user operates the computer host 2 to make the computer host 2 control the switch device 1 through the driver program to enter the manual adjustment mode.

Step S21 : the processing unit 10 receives a critical time setting signal via the transmission unit 12 . In one embodiment, the user inputs the desired time by operating the computer mainframe 2 , and the computer mainframe 2 generates a critical time setting signal according to the desired time input by the user, and sends it to the switch device 1 .

Step S22: The processing unit 10 adjusts the critical time to the desired time input by the user according to the critical time setting signal, thereby completing the manual adjustment of the critical time.

Please refer to FIG. 3 and FIG. 5 together. FIG. 5 is a flowchart of the automatic adjustment of the critical time according to the third embodiment of the present invention. This embodiment further provides a function of automatically adjusting the critical time, which can automatically detect the state of the touch switch 11 and automatically set the optimal critical time to achieve the best continuous operation experience.

Step S30: The processing unit 10 switches to the automatic adjustment mode according to the user operation or automatically. In the automatic adjustment mode, the processing unit 10 continuously monitors the electrical signal triggered by the contact switch 11 .

In one embodiment, the user operates the computer host 2 to make the computer host 2 control the switch device 1 to enter the automatic adjustment mode through the driver program.

Step S31: The processing unit 10 determines whether the contact switch 11 is operated according to the received electrical signal.

If the processing unit 10 determines that the contact switch 11 is operated, step S32 is executed. Otherwise, the processing unit 10 executes step S31 again.

In one embodiment, the driver program can control the host computer 2 to prompt the user to operate the touch switches 11 in sequence on the display, so that the processing unit 10 can obtain the electrical signals of the touch switches 11 .

Step S32: The processing unit 10 analyzes and detects the electrical signals triggered continuously by the touch switch 11 .

Step S33: The processing unit 10 identifies the bouncing noise in the electrical signal, and calculates the noise time of the bouncing noise, that is, the duration of the bouncing noise.

Step S34: The processing unit 10 adjusts the critical time according to the noise time, wherein the adjusted critical time must not be less than the noise time to achieve the function of suppressing bouncing noise, thereby completing the automatic adjustment of the critical time. .

In one embodiment, the processing unit 10 can calculate the corresponding multiple noise times according to the electrical signal triggered multiple times by the same contact switch 11, and then adjust the critical time according to the multiple noise times, such as using multiple The average or maximum value of the noise time is used as the critical time.

Certainly, the present invention also can have other multiple embodiments, without departing from the spirit and essence of the present invention, those skilled in the art of the present invention can make various corresponding changes and deformations according to the present invention, but these Corresponding changes and deformations should all belong to the appended patent scope of the present invention.

S10-S16: Monitoring and suppression steps

Claims (10)

A method for suppressing bouncing noise is used for a switch device, the switch device includes a contact switch, a processing unit and a transmission unit for connecting to a computer host, the method for suppressing bouncing noise includes the following steps: a ) when the processing unit continuously monitors the electrical signal triggered by the contact switch; b) when it is judged that the contact switch is operated according to the electrical signal, immediately output the information corresponding to the contact switch and the electrical signal through the transmission unit c) count a critical time when the contact switch is operated, and stop judging whether the contact switch is operated again within the critical time; and d) continue to follow the critical time after the critical time passes The electrical signal determines whether the contact switch is operated again. The method for suppressing bouncing noise as claimed in item 1, wherein the step b) is to determine that the contact switch is operated when the potential of the electrical signal drops from a high level to a low level, or rises from a low level to a high level. The method for suppressing bouncing noise as described in claim 2, wherein the step b) is to determine the contact switch when the potential of the electrical signal drops below a potential lower limit or rises above a potential upper limit be manipulated. The method for suppressing bouncing noise as claimed in Claim 1, wherein the critical time is not greater than 15 milliseconds. The method for suppressing bouncing noise as claimed in claim 1, wherein the critical time is not less than 10 milliseconds. The method for suppressing bouncing noise as described in claim 1, which further includes the following steps before the step a): e1) receiving a critical time setting signal through the transmission unit in a manual adjustment mode; and e2) according to the The critical time setting signal adjusts the critical time. The method for suppressing bouncing noise as described in claim 1, further comprising the following steps: f1) when the contact switch is operated in an automatic adjustment mode, detecting the electrical signal triggered continuously by the contact switch; f2 ) identifying a bouncing noise in the electrical signal, and calculating a noise time of the bouncing noise; and f3) adjusting the critical time according to the noise time, wherein the adjusted critical time is not less than the noise time . The method for suppressing bouncing noise as claimed in item 1, wherein the contact switch includes a first conductive sheet, a second conductive sheet, an axis structure, a reset element and a keycap arranged above the axis structure ; The step a) is that the processing unit continuously monitors the electrical signal triggered when a contact state between the first conductive sheet and the second conductive sheet changes, wherein between the first conductive sheet and the second conductive sheet The contact state is that the keycap accepts an external force to move the axis structure toward a trigger position or the reset element provides a restoring force to move the axis structure toward a reset position, so that the axis structure is at the reset position and the trigger Changed when moving between locations. The method for suppressing bouncing noise as claimed in claim 1, wherein the processing unit, the transmission unit and a switch array comprising a plurality of the contact switches are arranged on the same circuit board; the step a) is that the processing unit passes The circuit board continuously monitors each contact switch touched The electrical signal sent; the step b) is that the processing unit controls the transmission unit to output the switch signal through the circuit board. The method for suppressing bouncing noise as claimed in item 9, wherein a plurality of the touch switches correspond to different critical times, and the step c) is to time the operated touch switch when the touch switch is operated The critical time corresponding to the touch switch, and stop judging whether the touch switch is operated again within the critical time.

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