Buzzer device, buzzer drive system and method thereof

Abstract

This invention provides a buzzer device, a drive system, and a drive method thereof that improve the sound quality of a buzzer by driving the buzzer using an analog signal. [Solution] The buzzer drive system 1 comprises a signal processing circuit 10, a filter circuit 20, and a drive circuit 30, and generates an analog drive voltage to improve the output sound quality of the buzzer 2. The signal processing circuit 10 performs signal processing on the audio signal and outputs an audio playback signal. The filter circuit 20 may include a low-pass filter and converts the audio playback signal into an analog signal and outputs an analog playback signal. The drive circuit 30 generates a drive voltage for the buzzer 2 based on the analog playback signal.

Description

Technical Field

[0005] , ,

[0001] The present invention relates to a buzzer device, a drive system and a method for driving the buzzer. More specifically, the present invention relates to a buzzer device, a drive system, and a driving method thereof configured to drive a buzzer using an analog signal.

Background Art

[0002] A buzzer is a device that generates sound and is widely used in products such as alarm devices, multimedia devices, car electronics devices, toys, etc. Buzzers are usually classified into piezoelectric types and electromagnetic types. When the buzzer is energized, a metal diaphragm inside the buzzer vibrates in a resonance chamber, generating sound.

Summary of the Invention

Problems to be Solved by the Invention

[0003] However, since conventional buzzers are mainly driven by digital signals, many buzzers can only generate single tones. Also, the details of the sound are often filtered by the buzzer, resulting in an output sound quality that is much lower compared to speakers. However, compared to speakers, buzzers still have advantages such as being small, having a large volume, low cost, and durability that cannot be substituted. Therefore, how to overcome the limitations of conventional buzzers has become an important issue for those with ordinary knowledge in this technical field.

[0004] Therefore, the inventor of the present invention considered that the above disadvantages could be improved and, as a result of intensive studies, arrived at the proposal of the present invention that reasonably and effectively improves the problems.

[0005] The present invention has been made in view of the above circumstances, and one of its objectives is to solve the problems described above. Specifically, the main objective of the present invention is to provide a buzzer device, a buzzer driving system, and a driving method that can drive a buzzer using an analog signal, improve the sound quality of the buzzer, and enable the buzzer to reproduce the sound details contained in the audio signal. [Means for solving the problem]

[0006] To achieve the above objective, a buzzer drive system according to one aspect of the present invention comprises a filter circuit and a drive circuit. The filter circuit is configured to receive an audio playback signal, filter the audio playback signal, and output an analog playback signal. The drive circuit is electrically connected to the filter circuit and is configured to output a drive voltage to the buzzer based on the analog playback signal.

[0007] In accordance with the object of the present invention, another embodiment of the present invention is a buzzer device further comprising a buzzer, a signal processing circuit, a filter circuit, and a drive circuit. The signal processing circuit is configured to perform a bandpass filter on an audio signal based on a first frequency band to generate an audio playback signal. The filter circuit is electrically connected to the signal processing circuit and is configured to filter the audio playback signal and output an analog playback signal. The drive circuit is electrically connected to the filter circuit and is configured to output a drive voltage to the buzzer based on the analog playback signal. The drive circuit operates at an operating voltage higher than the operating voltage of the filter circuit.

[0008] Based on the object of the present invention, a method for driving a buzzer, which is a further different aspect of the present invention, includes the steps of: receiving an audio signal; performing a bandpass filter on the audio signal based on a first frequency band to generate an audio playback signal; filtering the audio playback signal to output an analog playback signal; generating a single-ended signal based on the analog playback signal; generating a first voltage and a second voltage based on the single-ended signal; and generating a drive voltage for the buzzer based on the voltage difference between the first voltage and the second voltage. [Effects of the Invention]

[0009] As the present invention is configured as described above, it produces the following effects. Compared to conventional techniques that drive a buzzer using pulse width modulation (PWM) signals, the buzzer device, the buzzer drive system, and the drive method according to the present invention generate the drive voltage in response to the buzzer's demands using an analog signal. As a result, the buzzer is not limited to generating only single tones in response to digital signals, and can achieve speaker-like sound quality and reproduce sound details through analog signal drive. Furthermore, the filter circuit ensures the output sound quality of the buzzer by filtering out noise from the original audio signal.

[0010] The following information will become clear from the description in the specification and drawings described later. [Brief explanation of the drawing]

[0011] [Figure 1] This is a block diagram showing a buzzer drive system according to one embodiment of the present invention. [Figure 2] This is a block diagram showing a buzzer drive system according to another embodiment of the present invention. [Figure 3] This is a block diagram showing a buzzer device according to one embodiment of the present invention. [Figure 4]This is a flowchart showing a method for driving a buzzer according to one embodiment of the present invention. [Modes for carrying out the invention]

[0012] The present invention will be described below through embodiments, but these embodiments are not intended to limit the scope of the claims. Furthermore, not all combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0013] The drive system and method according to the present invention are characterized in that the buzzer 2 can be driven using an analog signal, and therefore the buzzer 2 operates without being limited by whether the input signal is analog or digital. Furthermore, due to the characteristics of the analog signal, the audio output from the buzzer 2 includes richer sound detail than that of a system limited to a single tone.

[0014] Possible embodiments of the present invention will be described in detail below with reference to the drawings. However, the details of the embodiments described below are not intended to limit the scope of the claims of the present invention, but are merely intended to facilitate understanding for those who are ordinarily skilled in the art.

[0015] As shown in Figure 1, a buzzer drive system 1 according to one embodiment of the present invention is electrically connected to a buzzer 2 and comprises a signal processing circuit 10, a filter circuit 20, and a drive circuit 30. The buzzer drive system 1 is implemented as a system independent of the buzzer 2 and is arranged separately from the buzzer 2. In this way, the buzzer drive system 1 can be directly applied to a conventional buzzer 2 without the need to modify the structure of the buzzer 2.

[0016] The signal processing circuit 10 receives an audio signal corresponding to the buzzer 2 and performs signal processing on the audio signal. The audio signal according to one embodiment of the present invention may be a digital audio signal or an analog audio signal from an external device. In one embodiment, the audio signal may include a human voice signal, a spoken audio signal, or a musical audio signal. In one embodiment, the analog audio signal may include an audio signal generated by performing audio signal processing in a specific frequency band on a human voice signal, a spoken audio signal, or a musical audio signal, and the above-described audio signal processing may include attenuation or enhancement of the intensity of the audio signal in a specific frequency band. In one embodiment, the analog audio signal may include an audio signal generated by applying a low-pass filter to a digital signal (e.g., a PWM signal). The above description is merely an example and does not limit the scope of protection of the present invention.

[0017] On the one hand, the signal processing circuit 10 performs a bandpass filter on the audio signal based on a first frequency band to generate an audio playback signal, filtering out components of the audio signal outside the first frequency band. The first frequency band corresponds to the audible frequency range of the human ear, such as 20 Hz to 20,000 Hz. The signal processing circuit 10 filters the audio signal using the first frequency band to remove audio components that are inaudible to the human ear.

[0018] On the other hand, the signal processing circuit 10 performs gain augmentation of the audio signal in the frequency domain based on a second frequency band to generate the audio playback signal. The signal processing circuit 10 increases the gain and strengthens the signal intensity of the components of the audio signal by adjusting the components of the audio signal within the second frequency band. The second frequency band corresponds to a frequency range in which the buzzer 2 exhibits a relatively weak frequency response, and the frequency response in that range is lower than a predetermined response threshold. The predetermined response threshold may be adjusted based on the type of buzzer 2 and specific application requirements.

[0019] In a preferred embodiment, the signal processing circuit 10 may perform at least one of the following types of signal processing on the audio signal so as to generate the audio reproduction signal. Execute a band-pass filter using the first frequency band, perform gain enhancement on the frequency domain based on the second frequency band, and remove components (or parts) of the audio signal having a gain lower than the predetermined gain. When the signal processing circuit 10 performs one or more types of signal processing on the audio signal, the present invention is not limited to the execution order of these processing methods, and the order of different signal processing steps may be mutually interchanged.

[0020] For example, first, the signal processing circuit 10 may perform a band-pass filter on the audio signal using the first frequency band. Next, gain enhancement is performed on the frequency domain of the filtered audio signal based on the second frequency band so as to generate the audio reproduction signal. Alternatively, first, the signal processing circuit 10 can remove components (or parts) of the audio signal having a gain lower than the predetermined gain.Next, gain enhancement is performed on the frequency domain of the audio signal based on the second frequency band.Finally, a band-pass filter is performed on the audio signal using the first frequency band so as to generate the audio reproduction signal. Incidentally, the above description is for the purpose of illustration only and is not intended to limit the embodiments of the signal processing circuit 10. The order of the signal processing steps of the audio signal is not limited to the specific embodiments described in this specification.

[0021] The filter circuit 20 is electrically connected to the signal processing circuit 10, receives the audio reproduction signal, and filters the audio reproduction signal so as to generate an analog reproduction signal. When filtering the signal, the filter circuit 20 converts the audio reproduction signal into a corresponding analog signal. The filter circuit 20 may include a low-pass filter. The audio reproduction signal may be a pulse width modulation (PWM) signal or an analog signal.

[0022] The drive circuit 30 is electrically connected to the filter circuit 20, receives the analog reproduction signal, and generates a drive voltage for the buzzer 2 based on the analog reproduction signal.

[0023] As shown in FIG. 2, in the present embodiment, the audio reproduction signal is an audio differential signal generated by the signal processing circuit 10 processing the audio signal. The filter circuit 20 includes a first filter unit 21 and a second filter unit 22. The first filter unit 21 receives the positive component of the audio differential signal, and the second filter unit 22 receives the negative component of the audio differential signal. The filter circuit 20 filters the audio differential signal by the first filter unit 21 and the second filter unit 22 to generate the analog reproduction signal. The first filter unit 21 and the second filter unit 22 may each be realized as a low-pass filter. The analog reproduction signal may be an analog differential signal.

[0024] In the example of FIG. 2, the drive circuit 30 includes a differential amplifier 31, a first-stage amplifier 32, and a second-stage amplifier 33. The differential amplifier 31 has a pair of active input terminals and an output terminal. The pair of active input terminals are electrically connected to the first filter unit 21 and the second filter unit 22 so as to receive the analog differential signal. The differential amplifier 31 amplifies the analog differential signal and generates a single-ended signal output through the output terminal. The differential amplifier 31 not only amplifies the voltage of the analog differential signal, but also reduces the common-mode noise in the analog differential signal and improves the quality of the single-ended signal.

[0025] The first-stage amplifier 32 comprises a first input terminal, a second input terminal, and an output terminal. The first input terminal of the first-stage amplifier 32 is electrically connected to the output terminal of the differential amplifier 31 to receive the single-ended signal. The second input terminal of the first-stage amplifier 32 is electrically connected to a voltage reference. The output terminal of the first-stage amplifier 32 is electrically connected to the positive terminal of the buzzer 2. The first-stage amplifier 32 amplifies the single-ended signal and outputs a first voltage via the output terminal of the first-stage amplifier 32.

[0026] The second-stage amplifier 33 comprises a first input terminal, a second input terminal, and an output terminal. The first input terminal of the second-stage amplifier 33 is electrically connected to the output terminal of the first-stage amplifier 32 to receive the first voltage. The second input terminal of the second-stage amplifier 33 is electrically connected to the reference voltage (ref). The output terminal of the second-stage amplifier 33 is electrically connected to the negative terminal of the buzzer 2. The second-stage amplifier 33 amplifies the first voltage and outputs a second voltage via the output terminal of the second-stage amplifier 33.

[0027] The drive voltage corresponds to the difference between the first voltage and the second voltage. The drive circuit 30, using the first-stage amplifier 32 and the second-stage amplifier 33, outputs the drive voltage to the buzzer 2 and drives the buzzer 2 to generate a sound corresponding to the drive voltage.

[0028] In the example shown in Figure 2, the buzzer drive system 1 may further include a voltage boosting circuit 40. The voltage boosting circuit 40 is electrically connected to an external power supply and the drive circuit 30. The voltage boosting circuit 40 outputs an operating voltage to the drive circuit 30 based on an external voltage supplied from the external power supply, such that the operating voltage of the drive circuit 30 is higher than the operating voltage of the filter circuit 20.

[0029] As shown in Figure 3, according to one embodiment of the present invention, a buzzer device 100 is provided. The buzzer device 100 differs from the buzzer drive system 1 in that the signal processing circuit 10, the filter circuit 20, and the drive circuit 30 of the buzzer drive system 1 are integrated with the buzzer 2. Thus, the buzzer device 100 comprises the signal processing circuit 10, the filter circuit 20, the drive circuit 30, and the buzzer 2. Compared to the buzzer drive system 1 for application to a conventional buzzer 2, the buzzer device 100 provides the user with another option to meet different usage requirements for the buzzer 2.

[0030] The buzzer 2 may also be a piezoelectric buzzer 2, and mainly comprises a piezoelectric element, a metal plate, and a housing. The piezoelectric element may be formed of a piezoelectric ceramic material. When a voltage is applied to the piezoelectric element, the piezoelectric element deforms due to the piezoelectric effect, driving the metal plate to vibrate in a way that generates sound. The housing not only surrounds the piezoelectric element and the metal plate, but also forms a resonance chamber for the piezoelectric element and the metal plate.

[0031] Compared to conventional speakers, the buzzer 2 offers advantages such as low power consumption, high volume output, compact size, low cost, and high durability. Furthermore, due to its structural and material properties, the buzzer 2 exhibits greater durability and stability even in harsh environments such as high temperatures and high humidity. Unlike more expensive and easily damaged speakers, the buzzer 2 possesses irreplaceable advantages.

[0032] As shown in Figure 4, the buzzer driving method according to the present invention is applied to the buzzer 2 and may be executed by the buzzer driving system 1 or the buzzer device 100. The method includes the following steps.

[0033] S101: An audio signal is received and signal processing is performed to generate an audio playback signal. Step S101 may be performed by the signal processing circuit 10. The signal processing of the audio signal may include steps of performing a bandpass filter based on a first frequency band, performing gain enhancement for the frequency domain based on a second frequency band, or removing a portion of the audio signal that has a gain lower than a predetermined gain in the frequency domain. S102: The audio playback signal is filtered and an analog playback signal is output. Step S102 may be performed by the filter circuit 20. S103: Based on the analog playback signal, a drive voltage is output to the buzzer 2. Step S103 can be performed by the drive circuit 30. In step S103, first the analog playback signal is amplified to generate a single-ended signal, and then a first voltage and a second voltage are generated based on the single-ended signal. The drive voltage corresponds to the voltage difference between the first voltage and the second voltage.

[0034] In summary, the buzzer device 100, the buzzer drive system 1, and related methods according to the present invention are capable of processing an analog signal to generate the drive voltage in response to a request from the buzzer 2. Compared to conventional methods that operate the buzzer 2 using pulse width modulation (PWM) signals, the present invention allows the buzzer 2 to be operated without being limited to generating only a single tone with a digital signal. Instead, an analog signal is used, and by preserving the sonic details of the original sound, the buzzer 2 achieves sound quality comparable to that of a typical speaker while maintaining the advantages of high volume output, low material cost, and high durability.

[0035] In addition, the signal processing circuit 10 according to the present invention is capable of performing signal processing based on the frequency response of the corresponding buzzer 2, and after the original sound is processed, it is made to better suit the operating characteristics of the buzzer 2. Furthermore, the signal processing circuit 10 and the filter circuit 20 are capable of filtering noise from the original sound, further improving the output sound quality of the corresponding buzzer 2.

[0036] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications or improvements can be made to the above embodiments. It will be clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention. [Explanation of Symbols]

[0037] 1. Buzzer drive system 2 Buzzer 10 Signal Processing Circuits 20 Filter Circuits 21 First filter unit 22 Second filter unit 30 Drive Circuit 31 Differential Amplifier 32 First Stage Amplifier 33. Second Stage Amplifier 40 Voltage Boost Circuit 100 Buzzer device S101~S103 Step

Claims

1. A buzzer drive system (1) used in buzzer (2), A filter circuit (20) is configured to receive an audio playback signal, filter the audio playback signal, and output an analog playback signal. A buzzer drive system characterized by comprising: a drive circuit (30) which is electrically connected to the filter circuit (20) and electrically connected to the buzzer (2), and which is configured to output a drive voltage to the buzzer (2) based on the analog playback signal.

2. The buzzer drive system according to claim 1, characterized in that the filter circuit (20) includes a low-pass filter.

3. The buzzer drive system according to claim 1 or 2, characterized in that the audio playback signal is a pulse-width modulated (PWM) signal or an analog signal.

4. The aforementioned audio playback signal is an audio differential signal. The filter circuit (20) comprises a first filter unit (21) and a second filter unit (22). The aforementioned drive circuit (30) A differential amplifier (31) includes a pair of operational input terminals configured to receive the analog regeneration signal and an output terminal configured to output a single-ended signal, A first-stage amplifier (32) is electrically connected to the output terminal of the differential amplifier (31) and configured to output a first voltage to the output terminal of the first-stage amplifier (32) based on the single-ended signal, and the output terminal of the first-stage amplifier (32) is electrically connected to the positive terminal of the buzzer (2). A second-stage amplifier (33) is electrically connected to the output terminal of the first-stage amplifier (32) and configured to output a second voltage to the output terminal of the second-stage amplifier (33) based on the first voltage, the output terminal of the second-stage amplifier (33) is electrically connected to the negative terminal of the buzzer (2), The buzzer drive system according to any one of claims 1 to 3, characterized in that the drive voltage corresponds to the voltage difference between the first voltage and the second voltage.

5. The buzzer drive system according to any one of claims 1 to 4, further comprising a signal processing circuit (10) electrically connected to the filter circuit (20) and configured to receive an audio signal, wherein the signal processing circuit (10) is configured to perform a bandpass filter on the audio signal based on a first frequency band in order to generate the audio playback signal.

6. The buzzer drive system according to any one of claims 1 to 5, characterized in that the signal processing circuit (10) is configured to perform gain enhancement on the frequency domain of the audio signal based on a second frequency band in order to generate the audio playback signal.

7. The buzzer drive system according to claim 5 or 6, wherein the signal processing circuit (10) is configured to remove a portion of the audio signal in order to generate the audio playback signal, and the portion of the audio signal has a gain lower than a predetermined gain in the frequency domain.

8. The buzzer drive system according to any one of claims 1 to 7, characterized in that the operating voltage of the drive circuit (30) is higher than the operating voltage of the filter circuit (20).

9. Buzzer (2), A signal processing circuit (10) is configured to perform a bandpass filter on an audio signal based on a first frequency band in order to generate an audio playback signal, A filter circuit (20) is electrically connected to the signal processing circuit (10) and configured to filter the audio playback signal and output an analog playback signal, The system includes a drive circuit (30) which is electrically connected to the filter circuit (20) and configured to output a drive voltage to the buzzer (2) based on the analog playback signal, A buzzer device characterized in that the operating voltage of the drive circuit (30) is higher than the operating voltage of the filter circuit (20).

10. The steps include receiving an audio signal and The steps include: applying a bandpass filter to the audio signal based on a first frequency band to generate an audio playback signal; The steps include filtering the audio playback signal so as to output an analog playback signal, The steps include generating a single-ended signal based on the aforementioned analog playback signal, The steps include generating a first voltage and a second voltage based on the single-ended signal, A method for driving a buzzer, comprising the step of generating a drive voltage for the buzzer (2) based on the voltage difference between the first voltage and the second voltage.

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