Microphone senitivity inspection apparatus and microphone senitivity inspection method using the same

Abstract

The present invention relates to a microphone inspection device, and more specifically, to a microphone sensitivity inspection device capable of simultaneously and precisely inspecting the sensitivity of a plurality of microphones. The sensitivity testing device for a microphone according to the present invention comprises a sealed chamber, a frequency generator installed at one end of the chamber to generate a frequency band signal into the chamber, a reference microphone installed at the other end of the chamber to receive a frequency band signal that has passed through the chamber, at least one microphone to be tested installed at the other end of the chamber together with the reference microphone to receive a frequency band signal that has passed through the chamber, a signal generator that provides a frequency band signal and power required by the frequency generator, and a signal analyzer that calculates the sensitivity of the microphone to be tested by comparing the frequency band signal received by the reference microphone with the frequency band signal received by the microphone to be tested.

Description

Technology Field

[0001] The present invention relates to a microphone inspection device, and more specifically, to a microphone sensitivity inspection device capable of simultaneously and precisely inspecting the sensitivity of a plurality of microphones. Background Technology

[0003] Generally, a microphone is a device that converts external voice signals into electrical signals and is widely used in mobile communication terminals, information and communication devices, medical devices such as hearing aids, and miniaturized smart sensors or precision instruments.

[0004] When such microphones are manufactured or require periodic calibration during use due to lifespan and environment, they must undergo an inspection process to verify whether the sensitivity (V / Pa) of the microphone is within the upper and lower limits of the standard specifications.

[0005] However, conventionally, microphone sensitivity testing is performed as an individual process for each microphone, which takes a long time to test and requires multiple inspection devices. Furthermore, since the testing must be conducted in an anechoic chamber made of sound-absorbing material to prevent the ingress of external sound or the reflection of electromagnetic waves, there was a problem in that the cost of equipping the testing facilities was excessively high.

[0006] In addition, there is a problem that sensitivity testing is difficult to perform normally in the low-frequency range where the output of the sound source is low, because the sound source is easily dispersed due to the characteristics of the anechoic chamber. The problem to be solved

[0008] The present invention was devised to solve the aforementioned problems, and aims to provide a microphone sensitivity testing device and method capable of simultaneously and precisely performing sensitivity testing on a plurality of microphones.

[0009] The problems of the present invention are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below. means of solving the problem

[0011] To achieve the above objective, the microphone sensitivity testing device of the present invention comprises a sealed chamber, a frequency generator installed at one end of the chamber to generate a frequency band signal into the chamber, a reference microphone installed at the other end of the chamber to receive a frequency band signal that has passed through the chamber, at least one microphone to be tested installed at the other end of the chamber together with the reference microphone to receive a frequency band signal that has passed through the chamber, a signal generator that provides a frequency band signal and power required by the frequency generator, and a signal analyzer that calculates the sensitivity of the microphone to be tested by comparing the frequency band signal received by the reference microphone with the frequency band signal received by the microphone to be tested.

[0012] Additionally, a first fixing member having a first through hole formed therein to which a frequency generator is closely coupled is attached to one end of the chamber, a second through hole corresponding to the first through hole is formed on one end of the chamber, a second fixing member having a plurality of third through holes formed therein to which a reference microphone and a microphone to be inspected are detachably fitted and coupled is attached to the other end of the chamber, and fourth through holes corresponding one-to-one with each of the third through holes may be formed on the other end of the chamber.

[0013] In addition, the method for testing the sensitivity of a microphone using the microphone sensitivity testing device of the present invention includes the step of a frequency generator generating a frequency band signal into the interior of a chamber, the step of the reference microphone and the microphone to be tested receiving the frequency band signal that has passed through the chamber, and the step of the signal analyzer calculating the sensitivity of the microphone to be tested by comparing the frequency band signal received by the reference microphone with the frequency band signal received by the microphone to be tested.

[0014] Additionally, the step of the signal analyzer calculating the sensitivity of the microphone to be tested by comparing the frequency band signal received by the reference microphone with the frequency band signal received by the microphone to be tested may include the step of calculating the sound pressure inside the chamber by frequency using the sensitivity of the reference microphone, and the step of calculating the sensitivity of the microphone to be tested by frequency using the calculated sound pressure inside the chamber by frequency.

[0015] In this case, in the step of calculating the sound pressure inside the chamber by frequency using the sensitivity of the reference microphone, the value obtained by dividing the magnitude of the frequency band signal received by the reference microphone by the sensitivity of the reference microphone can be calculated as the sound pressure inside the chamber by frequency.

[0016] In addition, in the step of calculating the frequency-specific sensitivity of the microphone to be tested using the sound pressure inside the chamber for each frequency calculated above, the value obtained by dividing the magnitude of the frequency band signal received by the microphone to be tested by the calculated sound pressure inside the chamber for each frequency may also be calculated as the frequency-specific sensitivity of the microphone to be tested.

[0017] Meanwhile, prior to the step in which the frequency generator generates a frequency band signal into the chamber, an additional step may be performed to calculate the frequency-specific sound pressure error rate for each inspection location and to check whether a sound pressure difference occurs according to the inspection location.

[0018] In this case, a reference microphone is connected to each of the third holes formed in the second fixed member, and then the absolute value obtained by subtracting 1 from the value obtained by dividing the frequency-dependent sound pressure value of the reference microphone on one side by the frequency-dependent sound pressure value of the reference microphone on the other side can be converted into a percentage. Effects of the invention

[0020] The present invention, configured as described above, has the effect of significantly improving productivity because it can simultaneously perform sensitivity tests on a plurality of microphones.

[0021] In addition, since the sensitivity test is performed inside a sealed chamber, the sound source is not easily dispersed unlike in a conventional anechoic chamber, allowing for precise sensitivity testing in the low-frequency range with low output. Furthermore, unlike conventional methods, there is no need to equip expensive facilities such as an anechoic chamber, which has the effect of minimizing testing costs.

[0022] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims. Brief explanation of the drawing

[0024] FIG. 1 is a cross-sectional view of a microphone sensitivity testing device according to the present invention. FIG. 2 is a right side view of a microphone sensitivity testing device according to the present invention. Figure 3 is a flowchart illustrating a method for testing the sensitivity of a microphone using a microphone sensitivity testing device. Figure 4 is a graph showing the frequency sensitivity of a microphone under inspection calculated by a signal analyzer constituting the present invention. Figure 5 is a graph showing the frequency-dependent sound pressure error rate of the microphone under inspection calculated for each location. Specific details for implementing the invention

[0025] The features and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments based on the accompanying drawings.

[0026] Prior to this, terms and words used in this specification and claims must be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0027] Furthermore, the terms and words used in this specification and claims are used merely to describe specific embodiments and are not intended to limit the invention.

[0028] For example, a singular expression includes a plural expression unless the context clearly indicates otherwise. Furthermore, terms such as "include," "equip," or "have" are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0029] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "above" another part, this includes not only the case where it is "directly above" the other part, but also the case where there is another part in between. Conversely, when a part such as a layer, membrane, region, or plate is said to be "below" another part, this includes not only the case where it is "directly below" the other part, but also the case where there is another part in between.

[0030] In addition, terms including ordinal numbers, such as "first," "second," etc., used in this specification may be used to describe various components, but said components are not limited by said terms, and said terms are used solely for the purpose of distinguishing one component from another.

[0031] Hereinafter, in describing an embodiment of the present invention in detail with reference to the drawings, the same reference numerals are used for identical components, and for clarity, only the different parts are described primarily to avoid duplication as much as possible.

[0032] As illustrated in FIGS. 1 and 2, the microphone sensitivity testing device of the present invention comprises a chamber (100), a frequency generator (200) installed at one end of the chamber (100), a reference microphone (300) installed at the other end of the chamber (100), a microphone to be tested (400) installed at the other end of the chamber (100) together with the reference microphone (300), a signal generator (500) connected to the frequency generator (200), and a signal analyzer (600) connected to the reference microphone (300) and the microphone to be tested (400).

[0033] The above chamber (100) has a sealed curved structure to prevent noise from entering from the outside and to ensure uniform transmission of sound sources.

[0034] In this embodiment, the chamber (100) is illustrated as being formed in a cylindrical shape of equal diameter with both ends closed to uniformly transmit a frequency band signal generated from one side to the other side, but it is not limited thereto.

[0035] A first fixing member (110) to which a frequency generator (200) is closely coupled may be installed at one end of the chamber (100).

[0036] In this case, the first fixing member (110) has a first through hole (111) formed in it that communicates with the frequency generator (200). Then, a second through hole (101) corresponding to the first through hole (111) is formed at one end of the chamber (100).

[0037] Accordingly, the frequency generator (200) is easily installed in a state of being connected to the chamber (100) through the first through hole (111) and the second through hole (101).

[0038] In addition, a second fixing member (120) may be installed at the other end of the chamber (100).

[0039] In this case, the second fixing member (120) is formed with a plurality of third holes (121) into which the reference microphone (300) and the microphone to be inspected (400) are detachably fitted and coupled.

[0040] And, at the other end of the chamber (100), fourth holes (102) are formed that correspond one-to-one with each third hole (121).

[0041] Accordingly, the above reference microphone (300) and the microphone to be inspected (400) can be easily installed in a state of being connected to the chamber (100) through the third through hole (121) and the fourth through hole (102).

[0042] Meanwhile, for easy installation of the reference microphone (300) and the microphone to be inspected (400), a separate coupling member (130) may be attached to the third through hole (121) to which the reference microphone (300) and the microphone to be inspected (400) are fitted in close contact.

[0043] The above frequency generator (200) is a device that generates a frequency band signal into the chamber (100) and may be a speaker.

[0044] The above reference microphone (300) is a ready-made product with a known sensitivity and receives a frequency band signal that has passed through the inside of the chamber (100).

[0045] The above-mentioned reference microphone (300) is installed as a single unit at the other end of the chamber (100).

[0046] The above-mentioned microphone (400) is a product whose sensitivity is to be tested, and receives a frequency band signal that has passed through the inside of the chamber (100).

[0047] The above-mentioned inspection target microphone (400) is installed at least one together with the reference microphone (300) at the other end of the chamber (100).

[0048] In this embodiment, the microphone to be tested (400) is positioned in the center so that the frequency band signal can be received without distortion, and the microphones to be tested (400) are arranged at regular intervals on the same radius around the reference microphone (300) so that the frequency-specific sound pressure error rate between the microphones to be tested (400) is minimized. However, this is not limited to this, and the arrangement of the reference microphone (300) and the microphones to be tested (400) can be varied as long as the position minimizes distortion of the frequency band signal and the frequency-specific sound pressure error rate.

[0049] The above signal generator (500) is connected to the frequency generator (200) and provides the frequency band signal and power required by the frequency generator (200).

[0050] The above signal analyzer (600) is connected to the microphone to be tested (400) and the microphone to be tested (400) to calculate the sensitivity of the microphone to be tested (400) by comparing the frequency band signal received by the reference microphone (300) with the frequency band signal received by the microphone to be tested (400).

[0051] A method for testing the sensitivity of a microphone using the microphone sensitivity testing device of the present invention configured as described above will be explained.

[0052] As illustrated in FIG. 3, first, a frequency generator (200) is driven through a signal generator (500) to generate a frequency band signal into the chamber (100). (S1)

[0053] A frequency band signal generated at one end of the chamber (100) by a frequency generator (200) is uniformly propagated to the other end of the chamber (100), and the frequency band signal is received by a reference microphone (300) and a test target microphone (400) installed at the other end of the chamber (100). (S2)

[0054] Then, the signal analyzer (600) calculates the sensitivity of the microphone (400) by comparing the frequency band signal received by the reference microphone (300) with the frequency band signal received by the microphone (400) to be tested. (S3)

[0055] That is, the signal analyzer (600) calculates the sound pressure within the frequency-specific chamber (100) using the sensitivity of the reference microphone (300) that is already known, and then calculates the frequency-specific sensitivity of the microphone (400) to be tested using the calculated sound pressure within the frequency-specific chamber (100).

[0056] At this time, the signal analyzer (600) calculates the sound pressure in the frequency-specific chamber (100) by dividing the magnitude of the frequency band signal received by the reference microphone (300) by the sensitivity of the reference microphone (300), which is already known, as shown in Equation 1 below.

[0057]

[0058] And, the signal analyzer (600) calculates the frequency sensitivity of the microphone (400) for each frequency by dividing the magnitude of the frequency band signal received by the microphone (400) for each frequency by the calculated frequency-specific sound pressure in the chamber, as shown in Equation 2 below.

[0059]

[0060] FIG. 4 is a graph showing the frequency sensitivity of a microphone to be tested calculated by a signal analyzer constituting the present invention, and if the frequency sensitivity of the microphone to be tested (400) calculated is within the upper and lower limits of the standard specifications, it is determined to be a good product.

[0061] Meanwhile, before the frequency generator (200) generates a frequency band signal into the chamber (100), a process may be performed to calculate the frequency-specific sound pressure error rate at each inspection location and to check whether a difference in sound pressure occurs depending on the inspection location.

[0062] In this case, the frequency-specific sound pressure error rate can be calculated by connecting a reference microphone (A), whose sensitivity is known in advance, to each of the third holes (121) formed in the second fixed member (120), and then converting the absolute value obtained by subtracting 1 from the value obtained by dividing the frequency-specific sound pressure value of the reference microphone (A) on one side by the frequency-specific sound pressure value of the reference microphone (B, C, D) on the other side, as shown in Equation 3 below, into a percentage.

[0063]

[0064] The sound pressure value for each frequency can be calculated using the above-mentioned mathematical formula 1.

[0065] As shown in FIG. 5, in this embodiment, a reference inspection target microphone (A) on one side is positioned in the center, and the reference inspection target microphones (B, C, D) on the other side are changed at each inspection position to calculate the frequency-specific sound pressure error rate.

[0066] Upon reviewing the graph, it can be seen that the same sound pressure was generated for the same frequency range at each inspection location.

[0067] Although not shown, if the coupling (130) where the reference microphone (A, B, C, D) is not installed is sealed using a plug, external noise is not introduced into the chamber (100) through the coupling (130), so the reliability of the inspection can be greatly improved.

[0068] Therefore, the operator can conduct a sensitivity test after confirming whether the frequency-specific sound pressure error rates calculated for each location are the same or satisfy a preset normal value range.

[0069] As such, the present invention can simultaneously and precisely perform sensitivity tests on a plurality of target microphones, thereby not only improving productivity but also providing very high test reliability.

[0070] In addition, since the sensitivity test is performed in a sealed chamber (100), there is no need to equip facilities such as an anechoic chamber, which significantly reduces costs, and allows for precise sensitivity testing in the low-frequency range where the output is low.

[0071] Although preferred embodiments of the present invention have been illustrated and described above with reference to the drawings, various modifications and changes may be made without departing from the spirit or scope of the invention as defined by the following claims, and such changes should also be included within the scope of the present invention. Explanation of the symbols

[0073] 100: Chamber 101: Second Communion 102: The Fourth Communion 110: First fixed member 111: The First Communion 120: Second fixed member 121: The Third Communion 200: Frequency generator 300: Reference microphone 400: Microphone under inspection 500: Signal generator 600: Signal Analyzer

Claims

Claim 1 A sealed chamber; a frequency generator installed at one end of the chamber to generate a frequency band signal into the chamber; a reference microphone installed at the other end of the chamber to receive the frequency band signal that has passed through the chamber; at least one microphone to be tested installed at the other end of the chamber together with the reference microphone to receive the frequency band signal that has passed through the chamber; and a signal generator that provides the frequency band signal and power required by the frequency generator. A microphone sensitivity testing device comprising: a signal analyzer that calculates the sensitivity of a microphone to be tested by comparing a frequency band signal received by a reference microphone with a frequency band signal received by a microphone to be tested; a first fixing member having a first through hole formed therein to which a frequency generator is closely coupled is attached to one end of the chamber, and a second through hole corresponding to the first through hole is formed on one end of the chamber; a second fixing member having a plurality of third through holes formed therein to which a reference microphone and microphones to be tested are detachably fitted and coupled is attached to the other end of the chamber, and fourth through holes corresponding one-to-one to each of the third through holes are formed on the other end of the chamber. Claim 2 delete Claim 3 A method for testing the sensitivity of a microphone using a microphone sensitivity testing device according to claim 1, comprising: a step in which a frequency generator generates a frequency band signal into the interior of a chamber; a step in which a reference microphone and a microphone to be tested receive the frequency band signal that has passed through the chamber; and a step in which a signal analyzer calculates the sensitivity of the microphone to be tested by comparing the frequency band signal received by the reference microphone with the frequency band signal received by the microphone to be tested. Claim 4 In paragraph 3, the step of the signal analyzer calculating the sensitivity of the microphone to be tested by comparing the frequency band signal received by the reference microphone with the frequency band signal received by the microphone to be tested comprises: a step of calculating the sound pressure inside the chamber by frequency using the sensitivity of the reference microphone; and a step of calculating the frequency sensitivity of the microphone to be tested using the calculated sound pressure inside the chamber by frequency. A method for testing the sensitivity of a microphone using a microphone sensitivity testing device. Claim 5 In claim 4, the step of calculating the sound pressure inside the chamber by frequency using the sensitivity of the reference microphone is to calculate the sound pressure inside the chamber by frequency by dividing the magnitude of the frequency band signal received by the reference microphone by the sensitivity of the reference microphone. A method for testing the sensitivity of a microphone using a microphone sensitivity testing device. Claim 6 In claim 4, the step of calculating the frequency-specific sensitivity of the microphone to be tested using the calculated frequency-specific sound pressure inside the chamber is to calculate the frequency-specific sensitivity of the microphone to be tested by dividing the magnitude of the frequency band signal received by the microphone to be tested by the calculated frequency-specific sound pressure inside the chamber. Claim 7 A method for testing the sensitivity of a microphone using a microphone sensitivity testing device, wherein, in paragraph 3, prior to the step of the frequency generator generating a frequency band signal into the chamber, an additional step is taken to calculate a frequency-specific sound pressure error rate for each test position and to check whether a sound pressure difference occurs according to the test position. Claim 8 A method for testing the sensitivity of a microphone using a microphone sensitivity testing device, wherein, in claim 7, the frequency-specific sound pressure error rate is calculated by coupling a reference microphone to each of the third holes formed in the second fixed member, and then converting the absolute value obtained by subtracting 1 from the value obtained by dividing the frequency-specific sound pressure value of the reference microphone on one side by the frequency-specific sound pressure value of the reference microphone on the other side into a percentage.

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