Pickup unit of photoacoustic microphone

Abstract

The photoacoustic microphone pickup unit comprises an acoustic cavity, a vibrating diaphragm is fixed to the open end face of the acoustic cavity through a fixing ring, the fixing ring and the acoustic cavity are fastened through a screw, a collimator is arranged at the center of the end face, corresponding to the open end, of the acoustic cavity, a damping plate is arranged in the acoustic cavity, and the damping plate is arranged in the acoustic cavity. And a plurality of through holes are formed in the damping plate. Through the design of the acoustic cavity and the damping plate structure, sound waves can be better collected and form coherent interference with optical signals, and the sound transmission effect is further improved.

Description

Technical Field

[0001] The disclosed embodiments relate to the technical field of recording equipment, and in particular to a photoacoustic microphone pickup unit. Background Art

[0002] The information disclosed in this background technology section is only intended to increase the understanding of the overall background of the present disclosure, and shall not necessarily be regarded as an admission or any form of suggestion that the information constitutes the relevant technology that has been known to ordinary technicians in the field.

[0003] In the related technology, the condenser microphone is an active device that completes acoustic-electrical energy conversion by applying an external polarization voltage. Its excellent acoustic performance makes it widely used. The reliability of the condenser microphone will be seriously affected in harsh environments such as high temperature, high humidity, and salt spray. Due to the effect of sound wave pressure, the traditional microphone pickup unit has a poor effect on the collection of sound waves, resulting in weak sound amplitude, which affects the sound transmission effect;

[0004] In addition, certain specific outdoor sound pickup scenarios have extremely strict requirements on product reliability. In this usage scenario, the sound pickup noise problem caused by humidity is a key factor affecting the reliability of condenser microphones, and also restricts the application of condenser microphones in outdoor and other occasions. At present, the industry hopes to solve the problem of condenser microphone pickup reliability by studying the structure of the pickup unit, improving the preparation and molding methods of the diaphragm and the plate, and optimizing the assembly and manufacturing process of the pickup unit. Utility Model Content

[0005] To this end, the embodiments of the present disclosure provide a photoacoustic microphone pickup unit and a photoacoustic microphone to solve the problem of poor sound transmission effect caused by poor sound wave focusing effect in the related art.

[0006] In order to achieve the above objectives, the embodiments of the present disclosure provide the following technical solutions:

[0007] In a first aspect of an embodiment of the present disclosure, there is provided a photoacoustic microphone pickup unit, comprising an acoustic cavity, a diaphragm, a collimator, and a fixing ring;

[0008] The diaphragm is fixed to the open end face of the acoustic cavity by a fixing ring, the fixing ring and the acoustic cavity are fastened by screws, the collimator is arranged at the center of the end face of the acoustic cavity corresponding to the open end, a damping plate is arranged inside the acoustic cavity, and a plurality of through holes are arranged on the damping plate.

[0009] In one embodiment of the present disclosure, the through hole includes a central hole corresponding to the collimator and evenly arranged acoustic holes.

[0010] In one embodiment of the present disclosure, the diameter of the central hole is larger than the diameter of the acoustic hole and is the same as the diameter of the corresponding collimator.

[0011] In one embodiment of the present disclosure, a polyester gasket is provided between the contact surface of the fixing ring and the acoustic cavity, the inner diameter of the polyester gasket is smaller than the inner diameters of the acoustic cavity and the fixing ring, and the diameters of the acoustic cavity and the fixing ring are the same.

[0012] In one embodiment of the present disclosure, the diaphragm is fixed between the acoustic cavity and the fixing ring and contacts the polyester gasket, the diaphragm is arranged on a side close to the fixing ring, and a vibration output detection port of the diaphragm is provided on the side of the acoustic cavity.

[0013] In an embodiment of the present disclosure, the fixing ring is provided with a plurality of through holes, and the through holes correspond to the areas corresponding to the diaphragm.

[0014] According to the embodiments of the present disclosure, the pickup unit has the following advantages: it includes an acoustic cavity, the diaphragm is fixed to the open end face of the acoustic cavity by a fixing ring, the fixing ring and the acoustic cavity are fastened by screws, a collimator is arranged at the center of the end face of the acoustic cavity corresponding to the open end, a damping plate is arranged inside the acoustic cavity, and a plurality of through holes are arranged on the damping plate. By designing the acoustic cavity and the damping plate structure, the sound waves can be better collected and form coherent interference with the optical signal, thereby improving the sound transmission effect;

[0015] The photoacoustic microphone provided by the present disclosure achieves a better sound transmission effect and improves the stability of the microphone under the cooperation of the sound pickup unit and the control board. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present disclosure or the technical solutions in the related technologies, the following briefly introduces the drawings required for the embodiments or the related technical descriptions. Obviously, the drawings described below are only exemplary, and for ordinary technicians in this field, other implementation drawings can be derived from the provided drawings without creative work.

[0017] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present disclosure can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present disclosure, should still fall within the scope of the technical contents disclosed in the present disclosure.

[0018] Figure 1 A stereoscopic diagram of a photoacoustic microphone pickup unit provided by an embodiment of the present disclosure;

[0019] Figure 2 A front view of a photoacoustic microphone pickup unit provided in an embodiment of the present disclosure;

[0020] Figure 3 for Figure 2 Sectional view of the structure along the AA axis;

[0021] Figure 4 for Figure 3 A magnified view of the structure at position I in the middle;

[0022] Figure 5 A front view of the interior of an acoustic cavity in a pickup unit of a photoacoustic microphone provided in an embodiment of the present disclosure;

[0023] Figure 6 A frequency displacement amplitude curve of an acoustic cavity in a pickup unit of a photoacoustic microphone provided in an embodiment of the present disclosure;

[0024] In the figure: 1. acoustic cavity; 2. diaphragm; 3. collimator; 4. fixing ring; 5. damping plate; 6. center hole; 7. sound hole; 8. polyester gasket; 9. vibration output detection port; 10. through hole. DETAILED DESCRIPTION

[0025] The following is a description of the implementation methods of the present disclosure by specific specific embodiments. People familiar with the technology can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present disclosure, but not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present disclosure.

[0026] The terms such as "upper", "lower", "left", "right", "middle", etc. cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present disclosure. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present disclosure without substantially changing the technical content.

[0027] like Figure 1-5 As shown, it shows a stereoscopic view of the photoacoustic microphone pickup unit provided by the embodiment of the present disclosure. The pickup unit includes an acoustic cavity 1, a diaphragm 2, a collimator 3 and a fixing ring 4;

[0028] The diaphragm 2 is fixed to the open end face of the acoustic cavity 1 by a fixing ring 4, and the fixing ring 4 and the acoustic cavity 1 are fastened by screws. A collimator 3 is arranged at the center of the end face of the acoustic cavity 1 corresponding to the open end, and a damping plate 5 is arranged inside the acoustic cavity 1, and a plurality of through holes are arranged on the damping plate 5.

[0029] By designing the acoustic cavity 1 and the damping plate 5 structure, the sound waves can be better gathered and form coherent interference with the optical signal, thereby improving the sound transmission effect.

[0030] In one embodiment of the present disclosure, the through hole includes a central hole 6 corresponding to the collimator 3 and evenly arranged acoustic holes 7 .

[0031] In one embodiment of the present disclosure, in order to ensure the maximum effect of coherent interference to guarantee the stable output of the sound signal, the diameter of the central hole 6 is larger than the diameter of the sound hole 7 and is the same as the diameter of the corresponding collimator 3 .

[0032] In one embodiment of the present disclosure, in order to reduce the vibration resonance formed between the fixing ring 4 and the acoustic cavity 1 under the action of sound waves and affect the sound transmission effect, a polyester gasket 8 is provided between the contact surfaces of the fixing ring 4 and the acoustic cavity 1. The inner diameter of the polyester gasket 8 is smaller than the inner diameters of the acoustic cavity 1 and the fixing ring 4, and the diameters of the acoustic cavity 1 and the fixing ring 4 are the same.

[0033] In one embodiment of the present disclosure, the diaphragm 2 is fixed between the acoustic cavity 1 and the fixing ring 4 and is in contact with the polyester gasket 8. The diaphragm 2 is arranged on the side close to the fixing ring 4. The side of the acoustic cavity 1 is provided with a vibration output detection port 9 of the diaphragm 2, which can check the vibration effect of the diaphragm 2 during the pickup unit test.

[0034] In one embodiment of the present disclosure, in order to ensure the stability between the fixing ring 4 and the acoustic cavity 1 of the diaphragm 2 and improve the effect, the fixing ring 4 is provided with a plurality of through holes 10, and the through holes 10 correspond to the corresponding areas of the diaphragm 2. It is mainly the tension formed by the vibration that pulls the diaphragm 2, and the diaphragm 2 at the through holes 10 is in a relaxed state and can form resonance, thereby improving the sound transmission effect. There are four through holes 10 and they are evenly distributed on the fixing ring 4.

[0035] In the present disclosure, the fixing ring 4 is a metal ring with an outer diameter of 20 mm and an inner diameter of 17.4 mm; the diaphragm 2 is a polymer flexible film with a thickness of 6 μm, and the material is PET; the thickness h of the polyester gasket 8 is 30 μm; the damping plate 5 has an outer diameter of 20 mm, an inner diameter of 17.6 mm, and a thickness of B=1.5 mm, the diameter of the center hole 6 is 2 mm, the number of sound holes 7 is 20, and the diameter of the sound holes 7 is 1.6 mm.

[0036] According to the pickup unit of the above structure, the frequency displacement amplitude of the acoustic cavity filter structure is obtained by using the electric power acoustic analog simulation software (Multisim) as follows: Figure 6 As shown, the maximum vibration displacement of the vibration system composed of the diaphragm 2 and the acoustic cavity 1 is less than 75nm by fixing the various parameter values ​​of the acoustic cavity filter structure. By adjusting the physical parameters such as the aperture and the hole depth, the maximum displacement without aliasing of the modulated signal can be obtained to improve the sound transmission effect.

[0037] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0038] Although the present disclosure has been described in detail above with general descriptions and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made to the present disclosure. Therefore, these modifications or improvements made without departing from the spirit of the present disclosure are within the scope of protection claimed by the present disclosure.

Claims

1. A photoacoustic microphone pickup unit, characterized in that: It includes an acoustic cavity, a diaphragm, a collimator and a fixing ring; The diaphragm is fixed to the open end face of the acoustic cavity by a fixing ring, the fixing ring and the acoustic cavity are fastened by screws, the collimator is arranged at the center of the end face of the acoustic cavity corresponding to the open end, a damping plate is arranged inside the acoustic cavity, and a plurality of through holes are arranged on the damping plate.

2. The photoacoustic microphone pickup unit according to claim 1, characterized in that: The through hole includes a central hole corresponding to the collimator and evenly arranged acoustic holes.

3. The photoacoustic microphone pickup unit according to claim 2, characterized in that: The diameter of the central hole is larger than the diameter of the acoustic hole and is the same as the diameter of the corresponding collimator.

4. The photoacoustic microphone pickup unit according to claim 1, characterized in that: A polyester gasket is provided between the contact surface of the fixing ring and the acoustic cavity, the inner diameter of the polyester gasket is smaller than the inner diameters of the acoustic cavity and the fixing ring, and the diameters of the acoustic cavity and the fixing ring are the same.

5. The photoacoustic microphone pickup unit according to claim 4, characterized in that: The diaphragm is fixed between the acoustic cavity and the fixing ring and is in contact with the polyester gasket. The diaphragm is arranged on a side close to the fixing ring. A vibration output detection port of the diaphragm is arranged on the side of the acoustic cavity.

6. The photoacoustic microphone pickup unit according to claim 1, characterized in that: The fixing ring is provided with a plurality of through holes, and the through holes correspond to the corresponding areas of the diaphragm.

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