Sound-generating device and display device

Abstract

This invention discloses a sound-generating device and a display device, relating to the field of subwoofer technology. The sound-generating device includes a housing and two sound-generating units. The housing contains an independent first cavity and a second cavity, the first cavity having a larger volume than the second cavity. The first cavity communicates with the outside through a first opening on the housing, and the second cavity communicates with the outside through a second opening on the housing. The two sound-generating units are respectively installed at the first opening and the second opening. The technical solution provided by this invention uses two cavities of different sizes. The cavity with a smaller volume has a higher resonant frequency, resulting in a more powerful bass response; while the cavity with a larger volume has a lower resonant frequency, resulting in a more deep bass response. These two elements complement each other to create a deep and powerful bass performance, achieving the technical effect of satisfying both low-frequency depth and bass power in the sound-generating device.

Description

Technical Field

[0001] This invention relates to the field of bass speaker technology, and in particular to a sound-generating device and a display device. Background Technology

[0002] Driven by technological advancements and consumer demand, television sets are becoming increasingly thinner. Data shows that shrinking living spaces in modern homes are prompting televisions to evolve towards ultra-thin designs, which are better suited for smaller apartments or older neighborhoods.

[0003] The trend towards ultra-thin TVs has led to a similar trend in TV speaker design, which presents a significant challenge to TV sound quality, especially in the low frequencies. Due to limitations in volume and unit thickness, it is difficult to achieve both deep bass extension and powerful bass. Summary of the Invention

[0004] The main objective of this invention is to provide a sound-generating device and a display device, which aims to enable the sound-generating device to satisfy both low-frequency extension and bass intensity.

[0005] To achieve the above objectives, the present invention proposes a sound-generating device comprising: a housing and two sound-generating units; the housing having an independent first cavity and a second cavity formed therein, the volume of the first cavity being larger than the volume of the second cavity, the first cavity communicating with the outside through a first opening provided on the housing, and the second cavity communicating with the outside through a second opening provided on the housing; and the two sound-generating units being respectively installed in the first opening and the second opening.

[0006] In one embodiment, the inner wall of the first cavity surrounds the outer side of the inner wall of the second cavity.

[0007] In one embodiment, the sound-generating unit is sealed to the first opening, and the first cavity is also connected to the outside via a phase-reversing tube formed in the housing; and / or,

[0008] The sound-generating unit is sealed to the second opening so that the second cavity is in a sealed configuration.

[0009] In one embodiment, the cross-sectional area of ​​the phase inverter is S, and the effective vibration area of ​​the sound-generating unit at the first opening is Sd, where 0.1 ≤ S / Sd ≤ 0.4.

[0010] In one embodiment, the total length of the phase inverter satisfies the following formula: ,in: The total length of the phase inverter is L; The net volume of the shell is Vb; The free air resonance frequency of the sound-generating unit is Fs; The speed of sound is c; The cross-sectional area of ​​the phase inverter is S.

[0011] In one embodiment, the phase inverter includes two phase inverter sub-pipes, which are arranged opposite to each other.

[0012] In one embodiment, the phase inverter is bent and extended.

[0013] In one embodiment, a portion of the sidewall of the housing is used to form a portion of the cavity wall of the phase inverter.

[0014] In one embodiment, the sound-generating device further includes a passive radiator, and the housing is provided with a mounting port corresponding to the first cavity, and the passive radiator is mounted in the mounting port.

[0015] The present invention also proposes a display device, which includes a sound-emitting device, comprising: a housing and two sound-emitting units; the housing having an independent first cavity and a second cavity formed therein, the volume of the first cavity being larger than the volume of the second cavity, the first cavity communicating with the outside through a first opening provided on the housing, and the second cavity communicating with the outside through a second opening provided on the housing; and the two sound-emitting units being respectively installed in the first opening and the second opening.

[0016] The technical solution of this invention sets up two cavities of different sizes. The cavity with a smaller volume has a higher resonant frequency, making the sound more powerful; while the cavity with a larger volume has a lower resonant frequency, making the sound more deep. The two complement each other to form a deep and powerful bass performance, thus achieving the technical effect of enabling the sound-producing device to meet both the requirements of low-frequency depth and bass power. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0018] Figure 1 A schematic diagram of the structure of an embodiment of the sound-generating device provided by the present invention; Figure 2 for Figure 1 A full cross-sectional schematic diagram of the central sound-generating device; Figure 3 This is a schematic diagram of a structure of an embodiment of the display device provided by the present invention.

[0019] Explanation of icon numbers: 100. Sound-generating device; 1. Housing; 11. First cavity; 12. Second cavity; 13. First opening; 14. Second opening; 2. Phase inverter; 3. Sound-generating unit; 1000. Display device.

[0020] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0022] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0023] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0024] The trend towards ultra-thin TVs has led to a similar trend in TV speaker design, which presents a significant challenge to TV sound quality, especially in the low frequencies. Due to limitations in volume and unit thickness, it is difficult to achieve both deep bass extension and powerful bass.

[0025] This invention proposes a sound-generating device.

[0026] Please see Figure 1 and Figure 2In one embodiment of the present invention, the sound-generating device 100 includes: a housing 1 and two sound-generating units 3; the housing 1 has an independent first cavity 11 and a second cavity 12 formed inside it, the volume of the first cavity 11 is larger than the volume of the second cavity 12, the first cavity 11 communicates with the outside through a first opening 13 provided on the housing 1, and the second cavity 12 communicates with the outside through a second opening 14 provided on the housing 1; and the two sound-generating units 3 are respectively installed in the first opening 13 and the second opening 14.

[0027] In the technical solution of this invention, the sound-generating device 100 employs a dual-cavity design and dual-sound-generating units 3. The first cavity 11—a large cavity—is essential for achieving deep bass response, while the second cavity 12—a small cavity—can concentrate bass energy, optimize bass power, and prevent distortion. The two complement each other to create a powerful bass performance. Specifically, deep bass response is characterized by: the lower the frequency, the "deeper and more atmospheric" the sound; bass power is characterized by: the sound having impact and tightness.

[0028] For the larger first cavity 11: it provides the physical basis for "low-frequency extension". The essence of low-frequency sound waves is the large-amplitude vibration of air. Its propagation and reproduction require two key conditions, which the large cavity is well-suited for: First, sufficient air load reduces vibration resistance; when the diaphragm of the sound-generating unit 3 vibrates, it needs to push the air inside the cavity to form sound waves. Low frequencies have extremely long wavelengths. If the cavity is too small, the amount of internal air is small and the rigidity is high, the diaphragm will be subject to increased air resistance, causing the diaphragm to be unable to vibrate fully and unable to reproduce the large-amplitude vibration of low frequencies, resulting in insufficient low-frequency extension. The larger cavity has a larger volume and sufficient internal air volume, resulting in less resistance to the diaphragm, allowing the diaphragm to vibrate fully and achieve the effect of sound extension. Second, it reduces standing waves and lowers low-frequency distortion. Standing waves are interference signals formed by the superposition of reflected sound waves inside the cavity, which can cause low-frequency muddiness and peak-valley distortion. The larger cavity size makes it easier to avoid the integer multiples of half the wavelength of low-frequency sound waves, and when combined with sound-absorbing cotton, it can further absorb reflected sound waves, making the low-frequency reproduction purer and avoiding the problem of deep but blurry sound.

[0029] While using only the first cavity 11 can achieve a deep bass response, a large cavity can lead to a problem: the large amount of air inside can cause insufficient energy dispersion and concentration when the diaphragm vibrates, resulting in a less powerful sound. To achieve a stronger bass response, a second cavity 12—a smaller cavity—is also included. The core function of this smaller cavity is to enhance bass power. With less air and higher rigidity, the diaphragm experiences greater air resistance, allowing it to stop vibrating quickly, reducing unnecessary vibrations, preventing a sluggish sound, and making the sound crisper and more powerful. The second cavity 12 has higher air resistance, creating stronger "elastic support" within the cavity when the driver unit vibrates, resulting in a faster vibration response and more direct energy transfer, manifesting as better bass impact and transient response. The independent design of the first cavity 11 and the second cavity 12 avoids sound wave interference, preventing energy dispersion or cancellation, thereby increasing the bass energy density for a more powerful sound, and preventing bass distortion and reduced power caused by sound wave interference. This ensures that the two acoustic properties do not cancel each other out, but rather complement each other and work simultaneously. It meets the requirement of delivering a deep and powerful sound.

[0030] In existing technologies, using a single cavity for sound generation presents a dilemma when both tweeter and woofer units are installed in the same cavity: On the one hand, if the cavity is too large, while it can provide sufficient low-frequency extension, excessive airflow leads to dispersed bass energy, severe reverberation, and insufficient power; furthermore, the shared air load between the tweeter and woofer causes sound wave interference and low-frequency distortion. On the other hand, if the cavity is too small, the woofer's stroke is limited, resulting in insufficient bass extension; and the excessive air damping in a small cavity leads to a harsh, lacking bass response. This embodiment effectively overcomes these problems, combining the advantages of both small and large cavities while resolving the issue of sound wave interference between the two types of cavities. It allows the superior sound characteristics emitted by both cavities to be superimposed, achieving a powerful and deep bass effect.

[0031] The housing 1 contains two independent cavities: a first cavity 11 and a second cavity 12. These cavities are separated by a partition within the housing 1, made of sound-absorbing material (such as a composite structure of rubber and sound-absorbing cotton) to prevent sound wave interference between the two cavities. Two sound-generating units 3 (such as loudspeakers) are installed at the first opening 13 and the second opening 14. The following requirements must be met: unit type compatibility; the phase consistency error between the two sound-generating units 3 must be ≤5°. Sealing requirements must also be met: the sound-generating unit 3 is interference-fitted with the opening edge via a sealing gasket and is detachably fixed to the housing 1 by screws or clips. The sealing gasket is made of silicone with a compression of 0.3-0.8mm to ensure airtightness and improve acoustic performance. The housing 1 is made of ABS engineering plastic or aluminum alloy through integral injection molding or die casting. The inner wall of the housing 1 is lined with a sound-absorbing cotton layer (1-3mm thick) to reduce cavity resonance noise.

[0032] With large and small cavities arranged side-by-side, low-frequency sound radiates only from one side, resulting in areas with strong low frequencies and areas with weak low frequencies. To create a surround sound field for low frequencies, in one embodiment, the inner wall of the first cavity 11 surrounds the outer wall of the second cavity 12. The first cavity 11 corresponds to the bass unit, and its core function is to reproduce low-frequency sound waves—low frequencies are characterized by omnidirectional diffusion. By wrapping the first cavity 11 around the second cavity 12, the sound waves from the bass unit radiate outwards from all sides of the second cavity 12. The listener can receive low-frequency sound waves from multiple directions, forming an enveloping low-frequency sound field, making the listening experience more immersive. It makes the listener feel enveloped by low-frequency sounds, rather than being impacted by sound waves from a single direction, thereby enhancing the user experience.

[0033] In addition, the high-frequency sound emitted by the second cavity 12 is clearly distinguished from the low-frequency sound emitted by the first cavity 11 (here, high frequency and low frequency are relative comparisons of the two sounds). The high-frequency sound waves (short wavelength, strong directionality) of the small cavity are concentrated in the central area for radiation. The high-frequency sound waves of the small cavity are more concentrated, which is more conducive to reflecting the strength of the sound. The high-frequency sound is in the central area and the directional propagation reduces the intersection with the low-frequency sound that spreads outward in the circumferential direction, making the sound more layered.

[0034] To enhance low-frequency extension and loudness, in one embodiment, the sound-generating unit 3 is sealed to the first opening 13, and the first cavity 11 is also connected to the outside through a bass reflex tube 2 formed in the housing 1. When the bass unit reproduces low frequencies, it needs to push a large amount of air to vibrate with a large amplitude. If the first cavity 11 is closed, the air inside the cavity will form elastic resistance. When the diaphragm vibrates backward, the air inside the cavity is compressed, the pressure increases, and it hinders the diaphragm from moving further backward, resulting in insufficient low-frequency extension. Moreover, the energy of pushing the air is consumed by the closed air, and the low-frequency loudness becomes weak. If the first cavity 11 is connected to the outside, the air inside the cavity can circulate with the outside air through the opening. When the diaphragm vibrates backward, the air inside the cavity can be discharged to the outside. When it vibrates forward, the outside air can be replenished into the cavity. This is equivalent to reducing the elastic resistance of the air to the diaphragm, allowing the diaphragm to vibrate with a larger stroke. This can both reproduce the extension of lower frequency sound waves and reduce energy loss, thereby improving low-frequency loudness.

[0035] When the cavity is simply open, low-frequency sound waves within it diffuse randomly in all directions, with some energy being reflected and canceled out. To further enhance the low-frequency extension and loudness, a phase inverter 2 is installed inside the first cavity 11, which is connected to the outside via a guide tube. While a simple open cavity 11 directly connecting to the outside reduces air resistance, it results in low-frequency sound wave extraction efficiency and phase disorder. The phase inverter 2, however, guides the low-frequency energy through resonance, allowing for more concentrated and efficient radiation. The phase inverter 2 and the first cavity 11 constitute a "Helmholtz resonator": the air column within the cavity resonates at a specific frequency in the phase inverter 2 (the resonant frequency is positively correlated with the length, diameter, and volume of the phase inverter 2). By designing the parameters of the bass reflex tube 2, the resonant frequency can be matched with the "lowest resonant frequency" of the sound-generating unit 3. When the diaphragm of the woofer vibrates, it not only radiates a positive wave forward, but the back wave generated by the backward vibration pushes the air column inside the cavity, which radiates outward after resonating through the bass reflex tube 2. At this time, the sound wave radiated by the bass reflex tube 2 is in phase with the sound wave radiated from the front of the woofer, which is equivalent to a dual low-frequency energy output, greatly improving the loudness of the deep low frequencies and further extending the bass extension. When the sound is simply open, the phase between the back wave and the positive wave is difficult to control, resulting in the phenomenon that some frequencies are amplified and others are attenuated. However, after precise calculation of the length and diameter of the bass reflex tube 2, it can ensure that "the back wave and the positive wave are in phase in all key low-frequency bands". The setting of the bass reflex tube 2 avoids the distortion caused by phase cancellation, making the low-frequency response curve smoother and the listening experience more balanced.

[0036] To achieve optimal synergy between the bass reflex tube 2, the sound-generating unit 3, and the first cavity 11, ensuring both the sound wave extraction efficiency of the bass reflex tube 2 and avoiding low-frequency distortion and attenuation due to area mismatch, it is necessary to rationally design the key parameters of the bass reflex tube 2. Therefore, the cross-sectional area of ​​the bass reflex tube 2 is S, and the effective vibration area of ​​the sound-generating unit 3 at the first opening 13 is Sd, where 0.1 ≤ S / Sd ≤ 0.4. The essence of this ratio range is to match the airflow capacity of the bass reflex tube 2 with the air-driving capacity of the sound-generating unit 3—ensuring that the bass reflex tube 2 does not become a bottleneck obstructing airflow while retaining its function of adjusting the sound wave phase.

[0037] Regarding the total length of the phase inverter 2, if it is too short, the backwave path and phase delay will be insufficient, causing the backwave to be out of phase with the positive wave (phase difference 180°), canceling each other out, resulting in a sharp drop in low-frequency loudness and shallow depth. If the phase inverter 2 is too long, the backwave phase delay will be too large, also deviating from the phase of the positive wave, resulting in "partial phase outage," with some frequencies being amplified and others weakened. Only with a suitable length can the phase delay of the backwave just compensate for the path difference, ultimately being in phase with the positive wave (phase difference ≤ 5°), achieving the superposition of dual low-frequency energy, resulting in deeper depth and higher loudness. Therefore, the length of the phase inverter 2 is an important design parameter. A suitable length allows the backwave and positive wave to be superimposed in phase, avoiding cancellation, and also avoiding wind noise and low-frequency muddiness. Therefore, the total length of the phase inverter 2 needs to satisfy the following formula: Wherein: the total length of the phase inverter 2 is L, in cm; the net volume of the housing 1 is Vb, in cm3; the free air resonance frequency of the sound-generating unit 3 is Fs, in Hz; the speed of sound is c, in cm / s; and the cross-sectional area of ​​the phase inverter 2 is S, in cm2.

[0038] Based on the above formula, the length of the phase inverter 2 may be greater than the single-side dimension of the housing 1. For a smaller housing 1 and a longer phase inverter 2, the phase inverter 2 is divided into multiple sections, ensuring that the sum of the lengths of the multiple phase inverter 2 meets the length requirement. In one embodiment, the phase inverter 2 includes two phase inverter sub-pipes, which are arranged opposite to each other. When multiple phase inverters 2 are arranged, they must be symmetrically arranged and have consistent parameters (to avoid phase confusion). Arrangement position: The multiple pipes must be symmetrically distributed around the first opening 13 (e.g., left-right symmetrical, top-bottom symmetrical) to ensure that the sound wave radiation direction of each phase inverter 2 is consistent, avoiding interference between the sound waves of different phase inverters 2; The structural parameters of the multiple phase inverters 2 must be consistent: ensuring that the resonant frequency and phase delay of each phase inverter 2 are the same, avoiding the situation where "some phase inverters 2 are in phase and some are out of phase," which would lead to low-frequency cancellation.

[0039] In order to avoid structural interference and optimize space utilization while setting an appropriate length for the phase inverter tube 2, the phase inverter tube 2 is bent and extended. The bent phase inverter tube 2 is more suitable for miniaturized product forms.

[0040] In order to simplify the mold structure and reduce the material used to make the housing 1, part of the sidewall of the housing 1 is used to form part of the cavity wall of the phase inverter 2.

[0041] In another embodiment without the phase inverter 2, the sound-generating device 100 further includes a passive radiator. The housing 1 has a mounting port corresponding to the first cavity 11, and the passive radiator is mounted in the mounting port. By replacing the phase inverter 2 with a passive radiator, low-frequency performance is optimized within a limited space.

[0042] The present invention also proposes a display device 1000, which includes a sound-emitting device 100. The specific structure of the sound-emitting device 100 is as described in the above embodiments. Since the display device 1000 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here. The sound-emitting device 100 includes: a housing 1 and two sound-emitting units 3; the housing 1 has a first cavity 11 and a second cavity 12 formed inside, which are independent of each other. The volume of the first cavity 11 is larger than the volume of the second cavity 12. The first cavity 11 communicates with the outside through a first opening 13 provided on the housing 1, and the second cavity 12 communicates with the outside through a second opening 14 provided on the housing 1; and the two sound-emitting units 3 are respectively installed in the first opening 13 and the second opening 14.

[0043] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A sound-generating device, characterized in that, include: A housing having internally formed a first cavity and a second cavity, the first cavity having a larger volume than the second cavity. The first cavity communicates with the outside through a first opening on the housing, and the second cavity communicates with the outside through a second opening on the housing; and... Two sound-producing units are respectively installed in the first opening and the second opening.

2. The sound-generating device as described in claim 1, characterized in that, The inner wall of the first cavity surrounds the outer side of the inner wall of the second cavity.

3. The sound-generating device as described in claim 1, characterized in that, The sound-generating unit is sealed and installed with the first opening, and the first cavity is also connected to the outside through a phase-reversing tube formed in the housing; and / or, The sound-generating unit is sealed to the second opening so that the second cavity is in a sealed configuration.

4. The sound-generating device as described in claim 3, characterized in that, The cross-sectional area of ​​the phase inverter is S, and the effective vibration area of ​​the sound-generating unit at the first opening is Sd, where 0.1 ≤ S / Sd ≤ 0.

4.

5. The sound-generating device as described in claim 3, characterized in that, The total length of the phase inverter satisfies the following formula: ,in: The total length of the phase inverter is L; The net volume of the shell is Vb; The free air resonance frequency of the sound-generating unit is Fs; The speed of sound is c; The cross-sectional area of ​​the phase inverter is S.

6. The sound-generating device as described in claim 3, characterized in that, The phase inverter includes two phase inverter branches, which are arranged opposite to each other.

7. The sound-generating device as described in claim 3, characterized in that, The phase inverter tube is bent and extended.

8. The sound-generating device as described in claim 3, characterized in that, A portion of the sidewall of the housing is used to form a portion of the cavity wall of the phase inverter.

9. The sound-generating device as claimed in claim 1, characterized in that, The sound-generating device also includes a passive radiator, and the housing is provided with a mounting port corresponding to the first cavity, and the passive radiator is installed in the mounting port.

10. A display device, characterized in that, Includes the sound-generating device as described in any one of claims 1-9.

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