Frequency variable speaker

Abstract

The present invention relates to a frequency-variable speaker, comprising: a front case on which a main speaker and a side speaker are installed; a rear case coupled to the rear of the front case; a port portion forming a passage through which sound travels to the outside of the rear case; an extension conduit portion in the shape of a conduit that slides in the longitudinal direction of the port portion; a length adjustment portion that receives electrical energy and moves the extension conduit portion in the longitudinal direction of the port portion; and a first adjustment portion that is installed in the extension conduit portion and adjusts the open cross-sectional area of ​​an inner passage provided in the extension conduit portion by means of a plate shape that rotates upon receiving electrical energy.

Description

Technology Field

[0001] The present invention relates to a frequency-variable speaker capable of being tuned to a frequency value desired by the user. Background Technology

[0002] Generally, a speaker is an acoustic device that radiates sound waves by converting electrical signals into vibrations of a diaphragm, thereby generating compressional waves in the air. Speakers convert electrical pulses into sound waves.

[0003] Speakers in which the diaphragm is placed directly in the air are called radiating speakers, while those in which the diaphragm is placed inside a horn are called horn speakers. Direct radiating speakers are mostly cone speakers commonly used in radios and stereo systems, although some use metal diaphragms.

[0004] Depending on the principle and method of converting electrical signals into sound waves, there are dynamic, electromagnetic, electrostatic, dielectric, and magnetostrictive types. The dynamic type, which offers good performance, is widely used for music playback and voice applications. The dynamic type utilizes the principle that when a voice signal current is passed through a coil located within the magnetic field of a permanent magnet, a mechanical force acts on the coil according to the strength of the current, thereby causing motion.

[0005] A port section may be installed in the speaker to amplify low frequencies. The port section is tubular in shape and forms a conduit connecting the inner and outer sides of the speaker. Low frequencies generated by the speaker are amplified through the port section and then travel to the outer side of the speaker.

[0006] Conventional speakers have the problem that it is difficult to change the frequency of the output sound because the shape of the port cannot be changed.

[0007] In addition, conventional port sections cannot change their length, making it difficult to change the low-frequency range of the output sound.

[0008] In addition, conventional port sections have difficulty changing the low-frequency of the output sound because they cannot adjust the cross-sectional area of ​​the passage provided on the inside.

[0009] The background technology of the present invention is disclosed in Korean Registered Patent Publication No. 10-2027478 (Registered September 25, 2019, Title of Invention: Speaker with Improved Effect of Port Resonance). The problem to be solved

[0010] The objective of the present invention is to provide a frequency-variable speaker capable of changing the frequency of sound output from the speaker.

[0011] In addition, the objective of the present invention is to provide a frequency-variable speaker capable of changing the length of the port portion.

[0012] In addition, the objective of the present invention is to provide a frequency-variable speaker capable of changing the frequency by opening and closing the inner passage of the port portion or by adjusting the open cross-sectional area of ​​the inner passage.

[0013] The objects of the present invention are not limited to those mentioned above, and other unmentioned objects and advantages of the present invention may be understood from the following description and will be more clearly understood by the embodiments of the present invention. Furthermore, it will be readily apparent that the objects and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims. means of solving the problem

[0014] A frequency-variable speaker according to the present invention for solving the problem described above is characterized by changing the frequency of the output sound by changing the shape of the port portion.

[0015] Specifically, since the linear drive unit is operated to vary the position of the extension conduit connected to the port, the frequency of the sound output through the port can be adjusted. In addition, since the linear drive unit is operated to rotate the screw bar, the linear length movement of the movable body connected to the screw bar can be precisely controlled, thereby allowing for fine adjustment of frequency tuning.

[0016] In addition, the present invention is characterized by the technical feature of changing the frequency of the output sound by adjusting the open cross-sectional area of ​​the inner passage provided in the port portion.

[0017] Specifically, when the first driving unit is operated to rotate the rotating member, the opening area of ​​the inner passage is adjusted so that the frequency of the sound output through the port can be changed.

[0018] In addition, the present invention allows the frequency of sound output through the port to be changed by adjusting the opening area of ​​the inner passage through the movement of the moving wing when the second driving unit is operated to rotate the opening / closing gear unit.

[0019] In addition, the present invention is characterized by a technical feature of setting the frequency by moving the position of the extension conduit connected to the port and by adjusting the open cross-sectional area of ​​the extension conduit.

[0020] A frequency-variable speaker according to the present invention comprises: a front case on which a main speaker and a side speaker are installed; a rear case coupled to the rear of the front case; a port portion installed in a mounting space provided between the front case and the rear case and forming a passage through which sound travels to the outside of the rear case through a connecting hole provided in the rear case; an extension conduit portion in the shape of a conduit connected to the end of the port portion located in the mounting space and sliding in the longitudinal direction of the port portion; a length adjustment portion connected to both sides of the port portion and the extension conduit portion, receiving electrical energy to move in the longitudinal direction of the port portion and moving the extension conduit portion; and a first adjustment portion installed in the extension conduit portion and adjusting the open cross-sectional area of ​​the inner passage provided in the extension conduit portion by means of a plate shape that rotates by receiving electrical energy.

[0021] Additionally, the length adjustment unit comprises a housing unit connected to a port unit, a linear drive unit installed in the housing unit that generates rotational power using electrical energy, a transmission gear unit equipped with multiple gears that rotate by receiving power from the linear drive unit, a driven gear that rotates by meshing with the transmission gear unit, a screw bar having the same rotational center as the driven gear and connected to the driven gear in a rod shape with a spiral gear formed on its outer side, a movable body unit having an inner hole into which the screw bar is inserted and which moves in a linear direction inside the housing unit by the rotation of the screw bar, and a rod member extending from the movable body unit and connected to an extension conduit unit.

[0022] Additionally, the first adjustment unit includes a fixed bracket fixed to the movable body, a first driving unit fixed to the fixed bracket and receiving electrical energy to supply rotational power, and a rotating member connected to the first output shaft of the first driving unit and adjusting the opening area of ​​the inner passage provided in the movable body by means of a rotating operation.

[0023] A frequency-variable speaker according to the present invention comprises: a front case on which a main speaker and a side speaker are installed; a rear case coupled to the rear of the front case; a port portion installed in a mounting space provided between the front case and the rear case and forming a passage through which sound travels to the outside of the rear case through a connecting hole provided in the rear case; an extension conduit portion in the shape of a conduit connected to the end of the port portion located in the mounting space and sliding in the longitudinal direction of the port portion; a length adjustment portion connected to both sides of the port portion and the extension conduit portion, receiving electrical energy to move in the longitudinal direction of the port portion and move the extension conduit portion; and a second adjustment portion installed in the extension conduit portion, which moves toward the center of an inner passage provided in the extension conduit portion or moves toward the outside of the extension conduit portion and adjusts the open cross-sectional area of ​​the extension conduit portion.

[0024] Additionally, the second control unit includes a motor bracket fixed to the extension conduit, a second drive unit fixed to the motor bracket and receiving electrical energy to supply rotational power, an output gear connected to the second output shaft of the second drive unit and rotating together with the second output shaft, with a gear formed along the outer circumference, and an opening / closing gear unit installed at the end of the extension conduit and moved by a gear that meshes with the output gear to adjust the open cross-sectional area of ​​the inner passage.

[0025] Additionally, the opening and closing gear section includes a fixed plate that is fixed to the end of the port section and has a first guide projection, a rotating plate that is installed in a position facing the fixed plate and has a first guide hole section in the shape of an elongated hole into which the first guide projection is inserted and caught, and a gear that rotates by meshing with the output gear and is formed along the outer surface, and a moving wing section located between the fixed plate and the rotating plate, having a center projection protruding toward the fixed plate that is inserted into a hole provided in the fixed plate to become the center of rotation and a second guide projection protruding toward the rotating plate. Effects of the invention

[0026] The frequency variable speaker according to the present invention can also satisfy various consumer preferences by operating the length adjustment unit and the first adjustment unit, or by operating the length adjustment unit and the second adjustment unit to adjust the low-frequency range using the port unit.

[0027] In addition, the present invention allows the length adjustment unit to operate and vary the position of the extension conduit unit connected to the end of the port unit, thereby adjusting the frequency of the sound output through the port unit to satisfy various user preferences.

[0028] In addition, the present invention allows for fine tuning of the frequency by precisely controlling the movement of the movable body part for changing the frequency through the operation of a linear drive unit using a motor.

[0029] In addition, the present invention allows the first or second control unit to operate to adjust the opening area of ​​the inner passage, thereby adjusting the frequency of the sound output through the port unit to satisfy various preferences of the user.

[0030] In addition, the present invention allows for fine tuning of the frequency by precisely controlling the rotation of a rotating member for changing the frequency when the first driving unit is operated.

[0031] In addition, the present invention allows for fine tuning of the frequency by precisely controlling the rotation of a rotating plate for changing the frequency through the operation of a second driving unit.

[0032] In addition to the effects described above, the specific effects of the present invention are described together with the specific details for implementing the invention below. Brief explanation of the drawing

[0033] FIG. 1 is a perspective view illustrating a frequency-variable speaker according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of a frequency-variable speaker according to one embodiment of the present invention. FIG. 3 is a front view illustrating the internal configuration of a frequency-variable speaker according to one embodiment of the present invention. FIG. 4 is a perspective view illustrating a length adjustment unit according to one embodiment of the present invention. FIG. 5 is a perspective view illustrating the main configuration of a length adjustment unit according to one embodiment of the present invention. FIG. 6 is a perspective view illustrating a transmission gear section according to one embodiment of the present invention. FIG. 7 is a cross-sectional view illustrating a screw bar and a moving body part according to one embodiment of the present invention. FIG. 8 is a perspective view illustrating the state in which a first control unit is installed according to one embodiment of the present invention. FIG. 9 is a perspective view illustrating a state in which the extension pipe section and the first adjustment section are moved by operating the length adjustment section according to one embodiment. FIG. 10 is a perspective view illustrating the state in which the first control unit is operated according to one embodiment of the present invention. FIG. 11 is a perspective view illustrating the state in which a second control unit is installed according to one embodiment of the present invention. FIG. 12 is a perspective view showing the rear side of a port section in which a second adjustment section and a length adjustment section are installed according to one embodiment of the present invention. FIG. 13 is an exploded perspective view of an opening / closing gear unit according to one embodiment of the present invention. FIG. 14 is an exploded perspective view showing a fixed plate and a movable wing part according to one embodiment of the present invention. FIG. 15 is a perspective view illustrating a state in which a movable wing part is coupled to a fixed plate according to one embodiment of the present invention. FIG. 16 is a perspective view of an opening / closing gear unit according to one embodiment of the present invention. FIG. 17 is a perspective view illustrating a state in which a moving wing portion according to one embodiment of the present invention is moved outward so that the opening and closing area of ​​the inner passage is increased. FIG. 18 is a perspective view illustrating a state in which a movable wing portion according to one embodiment of the present invention is moved outward and the inner passage is opened to the maximum extent. FIG. 19 is a perspective view illustrating a state in which the extension pipe section and the second adjustment section are moved by operating the length adjustment section according to one embodiment of the present invention. FIG. 20 is a perspective view illustrating the state in which the second control unit is operated according to one embodiment of the present invention. Specific details for implementing the invention

[0034] The aforementioned objectives, features, and advantages are described in detail below with reference to the attached drawings, thereby enabling those skilled in the art to easily implement the technical concept of the present invention. In describing the present invention, detailed descriptions of known technologies related to the present invention are omitted if it is determined that such descriptions would unnecessarily obscure the essence of the invention. Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the attached drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0035] FIG. 1 is a perspective view illustrating a frequency-variable speaker (1) according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of a frequency-variable speaker (1) according to one embodiment of the present invention, and FIG. 3 is a front view illustrating the internal configuration of a frequency-variable speaker (1) according to one embodiment of the present invention.

[0036] As illustrated in FIGS. 1 to 3, a frequency-variable speaker (1) according to one embodiment of the present invention can change the output frequency of the low frequency range by adjusting the protruding length of the extension conduit section (90) connected to the port section (50) or by adjusting the cross-sectional area of ​​the open passage of the extension conduit section (90). In addition, the frequency-variable speaker (1) can achieve more precise frequency tuning by simultaneously adjusting the protruding length of the extension conduit section (90) connected to the port section (50) and the cross-sectional area of ​​the open conduit section (90). Furthermore, the frequency change range can be increased by simultaneously adjusting the protruding length of the extension conduit section (90) connected to the port section (50) and the cross-sectional area of ​​the extension conduit section (90).

[0037] In a frequency-variable speaker (1) according to one embodiment of the present invention, a pipe-shaped port section (50) for reinforcing bass is installed, and a passage through which air and sound travel is provided inside the port section (50). The port section (50) is installed in a fixed state, and the extension conduit section (90) is installed in a state where it can slide at the free end of the port section (50).

[0038] The length adjustment unit (100) provided in the frequency variable speaker (1) uses a linear actuator and adjusts the protruding length of the extension tube section (90) which is formed in a tubular shape. Since the length adjustment unit (100) is operated to control the movement of the extension tube section (90) protruding outward from the port section (50), the tuning frequency value of the frequency variable speaker (1) can be changed so that the user can set it to a desired frequency.

[0039] In addition, a frequency-variable speaker (1) according to one embodiment of the present invention changes the low-frequency range by adjusting the opening area of ​​an inner passage (97) provided in an extension conduit (90) through a first adjustment unit (500) or a second adjustment unit (600). The port unit (50) is installed in a fixed state, and the first adjustment unit (500) or the second adjustment unit (600) is installed at the end of the extension conduit (90) to adjust the opening area of ​​the inner passage (97).

[0040] The first control unit (500) moves the rotating member (530) by operating the first driving unit (520) which utilizes the power of the motor. Since the rotating member (530) adjusts the opening area of ​​the inner passage (97) provided in the extension conduit (90), the frequency can be adjusted.

[0041] The second control unit (600) operates in an aperture manner to control the opening area of ​​the inner passage (97), thereby allowing the frequency to be controlled.

[0042] A frequency-variable speaker (1) according to one embodiment of the present invention can adjust the range of output frequencies by operating the length adjustment unit (100) and the first adjustment unit (500) together. Alternatively, the range of output frequencies can be adjusted by operating the length adjustment unit (100) and the second adjustment unit (600) together.

[0043] The front case (10) can be modified in various ways within the technical concept of installing the speaker. The speaker installed in the front case (10) may include a main speaker (20) and side speakers (30). In the present invention, the main speaker (20) responsible for the main output and the side speakers (30) installed on both sides of the main speaker (20) are described separately, but various modifications are also possible, such as using only the main speaker (20) in the front case (10).

[0044] A main speaker (20), which has a larger diameter than the side speaker (30), is installed in a central hole (12) that forms a hole in the center of the front panel (11). The side speakers (30) are installed on each side of the main speaker (20). According to one embodiment of the present invention, two side speakers (30) are installed on each side of the main speaker (20). Of course, the number and location of the main speaker (20) and the side speaker (30) can be changed according to the usage environment or the needs of the customer.

[0045] The front case (10) is in the shape of a rectangular box with an open rear and forms the front of the frequency-variable speaker (1). The front case (10) according to one embodiment of the present invention includes a front panel (11) and a side panel (17).

[0046] The front panel (11) is formed in a plate shape and has holes for installing a main speaker (20) and a side speaker (30). In one embodiment of the present invention, the front panel (11) is a rectangular plate, and a central hole portion (12) for mounting a main speaker (20) is provided in the center in the width direction. Side hole portions (13), which are holes for installing a side speaker (30), are provided on both sides of the central hole portion (12).

[0047] The side panel (17) extends from the edge of the front panel (11) toward the rear case (70). The side panel (17) has a rectangular frame shape, and the side panel (17) and the front panel (11) are manufactured as a single unit.

[0048] The port section (50) is installed in a mounting space (74) provided between the front case (10) and the rear case (70), and forms a passage through which sound travels to the outside of the rear case (70) through a connecting hole (72) provided in the rear case (70).

[0049] The port section (50) is a passage through which air in the space formed between the front case (10) and the rear case (70) moves to the outside of the frequency variable speaker (1). Air on the outside of the frequency variable speaker (1) may also move to the inside of the frequency variable speaker (1) through the port section (50).

[0050] The waves coming out of the frequency-variable speaker (1) through the port (50) reinforce the waves output to the front of the frequency-variable speaker (1). The port (50) sets the inherent resonant frequency of the frequency-variable speaker (1) even lower, thereby reinforcing the bass characteristics.

[0051] The port section (50) is located on the upper side of the main speaker (20) and is in the shape of a circular pipe bent into an "L" shape. One end of the port section (50) is connected to the rear case (70), and the other end of the port section (50) is connected to the extension tube section (90).

[0052] Since the cross-section of the port portion (50) is formed as a circular cross-section, the fluid resistance is reduced compared to a square cross-section, thereby reducing friction during fluid flow and improving energy loss, which can reduce sound source loss.

[0053] One end of the port portion (50) is in communication with a connection hole (72) provided in the rear case (70), and the other end of the port portion (50) is in communication with the inside of the frequency variable speaker (1). The port portion (50) according to one embodiment of the present invention includes a first conduit portion (52), a second conduit portion (54), and a first protruding projection (58).

[0054] The first conduit section (52) is installed on at least one of the upper and lower sides of the main speaker (20) and extends in the width direction of the front case (10). The first conduit section (52) is in the shape of a circular pipe.

[0055] The second conduit section (54) extends from the end of the first conduit section (52) toward the rear case (70) and communicates with the connection hole (72). The second conduit section (54) is a conduit shaped like an "L" bent from the first conduit section (52), and emits sound to the rear of the frequency variable speaker (1) through the connection hole (72) provided in the rear case (70).

[0056] The first conduit section (52) and the second conduit section (54) are connected, and since the total length of the port section (50) is increased compared to the conduit extended in a straight direction, the bass can be further reinforced. Since the part where it bends from the first conduit section (52) to the second conduit section (54) is formed as a curved surface, the loss of fluid energy can be minimized.

[0057] The first protruding projection (58) protrudes upward from the first conduit section (52) and forms a projection connected to the length adjustment section (100).

[0058] The extension pipe section (90) is connected to the end of the port section (50) located in the mounting space (74) and is shaped like a pipe that slides along the length of the port section (50). The extension pipe section (90) is shaped like a circular pipe and is installed so that it can slide when inserted into the inside of the port section (50).

[0059] Both the first conduit section (52) and the extension conduit section (90) are in the shape of circular pipes, and the inner diameter of the first conduit section (52) is formed to be equal to or larger than the outer diameter of the extension conduit section (90). Accordingly, the extension conduit section (90) is installed with the extension conduit section (90) inserted into the inside of the first conduit section (52), and the extension conduit section (90) is moved in the longitudinal direction of the first conduit section (52) by the operation of the length adjustment section (100).

[0060] The extension conduit section (90) is connected to the end of the port section (50), and various modifications are possible within the technical concept of sliding along the longitudinal direction of the port section (50). The second protruding projection (95) provided on the extension conduit section (90) is installed at a position facing the first protruding projection (58) and is connected to the length adjustment section (100) together with the first protruding projection (58).

[0061] The following explains that the tuning frequency changes according to the length of the port section (50) and the extension conduit section (90). It explains the change in frequency according to the change in the length of the port installed in the speaker.

[0062]

[0063] Factor output of power L 36.04810267 cm input D 9 cm input N 1 Opening input V(b) 31 Liter input f(b) 38 Hz input k 0.732 (constant)

[0064] In the above, the port is not a port part (50) according to one embodiment of the present invention, but is described using a general port used in a speaker as an example. This is a calculation formula to understand that the tuning frequency changes according to the change in the length of the port. The box volume is the volume of the case in which the speaker is installed. The formula for calculating the port length is defined as above, and if the above formula is rearranged for the tuning frequency F, it is as follows.

[0065]

[0066] Factor output of power f(b) 38 Hz input D 9 cm input N 1 Opening input V(b) 31 Liter input L 36.04810267 cm input k 0.732 (constant)

[0067] The above equation for the tuning frequency F can be verified, and based on this, the tuning frequency for ports of different lengths is verified. The lengths of the ports are set to 310mm, 325mm, and 360mm, and the respective tuning frequencies are calculated. Through this, it was confirmed that the tuning frequency decreases as the length of the port increases. If the tuning frequency is low, the frequency-variable speaker (1) can be set to allow hearing lower tones. As shown in the table below, when the length of the port is 310mm, the tuning frequency is 40.47135Hz.

[0068] Factor output of power f(b) 40.47135 Hz input D 9 cm input N 1 Opening input V(b) 31 Liter input L 31 cm input k 0.732 (constant)

[0069] As shown in the table below, when the length of the port is 325mm, the tuning frequency is 39.68721Hz.

[0070] Factor output of power f(b) 39.68721 Hz input D 9 cm input N 1 Opening input V(b) 31 Liter input L 32.5 cm input k 0.732 (constant)

[0071] As shown in the table below, when the length of the port is 360mm, the tuning frequency is 38.02145Hz.

[0072] Factor output of power f(b) 38.02145 Hz input D 9 cm input N 1 Opening input V(b) 31 Liter input L 36 cm input k 0.732 (constant)

[0073] The graph of the tuning frequency according to port length is as follows. As shown in the graph above, the result indicates that the port length decreases when the tuning frequency is high, and increases when the tuning frequency is low. The longer the port length, the more possible it is to set the low-frequency range of the tuning frequency.

[0074] When the length of the port is changed from 310mm to 360mm, the tuning frequency change range is 38Hz to 40.5Hz, with a change of 2.5Hz.

[0075] The following explains that the tuning frequency changes according to the opening area of ​​the inner passage (97) provided in the port section (50).

[0076]

[0077] The above equation for the tuning frequency F can be verified, and based on this, the tuning frequency for different port diameters (D) is verified. The diameter lengths were set to 7cm, 8cm, and 9cm to calculate the respective tuning frequencies, and through this, it can be seen that the tuning frequency increases as the diameter of the port increases. If the tuning frequency is low, the frequency-variable speaker (1) can be set to allow hearing a lower sound. As shown in the table below, when the diameter of the port is 7cm, the tuning frequency is 30.07643Hz.

[0078] Factor output of power f(b) 30.07643 Hz input D 7 cm input N 1 Opening input V(b) 31 Liter input L 36.0481 cm input k 0.732 (constant)

[0079] As shown in the table below, when the diameter of the port is 8 cm, the tuning frequency is 34.07152 Hz.

[0080] Factor output of power f(b) 34.07152 Hz input D 8 cm input N 1 Opening input V(b) 31 Liter input L 36.0481 cm input k 0.732 (constant)

[0081] As shown in the table below, when the diameter of the port is 9 cm, the tuning frequency is 38 Hz.

[0082] Factor output of power f(b) 38 Hz input D 9 cm input N 1 Opening input V(b) 31 Liter input L 36.0481 cm input k 0.732 (constant)

[0083] The graph of the tuning frequency according to port length is as follows.

[0084]

[0085] As shown in the graph and table above, the tuning frequency can be determined by changing the value D, which is the diameter of the port, to verify the correlation between the cross-sectional area of ​​the port and the tuning frequency. As mentioned above, the tuning frequency increases as the diameter of the port increases. If the tuning frequency decreases, the speaker can be set to allow for lower tones to be heard. As the diameter of the port decreases, it is possible to set the tuning frequency to a lower frequency range.

[0086] When the cross-sectional area of ​​the port changes from 70mm to 90mm, the tuning frequency change band changes from 30Hz to 38Hz, a change of 8Hz.

[0087] The diameter of the port has a greater effect on frequency change than the length of the port. When the length of the port and the cross-sectional area of ​​the port are changed together, the tuning frequency change band is 30Hz to 40.5Hz, and changes by 10.5Hz.

[0088] The inner enclosure (60) can be varied in various ways within the technical concept of being installed in a shape that surrounds the rear side of the side speaker (30). The inner enclosure (60) according to one embodiment of the present invention is a cuboid shape with a front opening facing the front case (10).

[0089] The inner enclosure (60) functions to prevent the front and rear spaces of the side speaker (30) from communicating with each other. Since the energy from the front and rear of the side speaker (30) does not meet, the sound of the side speaker (30) can be reproduced smoothly. Additionally, installing the inner enclosure (60) adds resonance inside the enclosure, so the bass can be reinforced and the sound characteristics can be changed.

[0090] The inner enclosure (60) can be modified into various shapes, including a cuboidal shape and a circular shape. The inner enclosure (60) according to one embodiment of the present invention is installed in a shape that surrounds the rear side of the second speaker (34) and is fixed in a state in contact with the rear side of the front case (10).

[0091] The rear case (70) can be modified in various ways within the technical concept of being coupled to the rear of the front case (10). The rear case (70) according to one embodiment of the present invention has a square plate shape and is fixed to the front case (10). Between the front case (10) and the rear case (70), a mounting space (74) is formed for installing a port part (50), an inner enclosure (60), a reinforcing part (80), an extension conduit part (90), a length adjustment part (100), and a first adjustment part (500).

[0092] The rear case (70) is provided with a connection hole (72) that communicates with the second conduit section (54) of the port section (50). Accordingly, sound transmitted through the extension conduit section (90) and the port section (50) can be propagated to the outside of the rear case (70) through the connection hole (72).

[0093] The reinforcing member (80) is installed in the shape of a plate with holes on the upper and lower sides of the inner enclosure (60), and restricts the vertical movement of the inner enclosure (60). In addition, the reinforcing member (80) reinforces the structural rigidity of the front panel (11), the side panel (17), the inner enclosure (60), and the rear case (70), and allows stress distribution to be achieved more easily, thereby reducing vibration and improving the durability of the parts.

[0094] An inner hole (82), which is a hole for air to move through, is formed in the plate-shaped reinforcing part (80). Accordingly, the spaces located on both sides of the reinforcing part (80) are connected to each other through the inner hole (82).

[0095] Reflected waves or standing waves generated inside the frequency-variable speaker (1) pass through the inner hole (82) and their speed is reduced. As the reflected waves and standing waves enter the inner hole (82) and then exit the inner hole (82), they generate vortices. These vortices act as aerodynamic drag, reducing the speed of the standing waves. The opening of the inner hole (82) also functions as an expanded resonance space.

[0096] FIG. 4 is a perspective view illustrating a length adjustment unit (100) according to one embodiment of the present invention.

[0097] As illustrated in FIGS. 3 and 4, the length adjustment unit (100) is connected to both ends of the port unit (50) and the extension conduit unit (90), and various modifications are possible within the technical concept of receiving electrical energy to move along the length direction of the port unit (50) and moving the extension conduit unit (90).

[0098] The length adjustment unit (100) can adjust the low frequency range by using an actuator to adjust the length of the extension conduit (90) protruding from the end of the port unit (50). The length adjustment unit (100) can be operated automatically or by the user setting an equalizer. Since the length of the extension conduit (90) protruding from the end of the port unit (50) is adjusted by the operation of the length adjustment unit (100), the characteristics of the low frequency range change.

[0099] A length adjustment unit (100) according to one embodiment of the present invention includes a housing unit (110), a linear drive unit (120), a transmission gear unit (130), a driven gear (140), a screw bar (150), a moving body unit (160), and a rod member (170).

[0100] The housing portion (110) is connected to the port portion (50) and is installed in a shape that encloses the main components of the length adjustment portion (100). The housing portion (110) according to one embodiment of the present invention includes a housing body (112) and a protruding body (114).

[0101] The housing body (112) is installed in a shape that encloses the driven gear (140), the screw bar (150), and the moving body part (160). Since the housing body (112) is installed in a shape that encloses the driving gear (122), the transmission gear part (130), and the driven gear (140), it is possible to prevent foreign matter from entering during gear operation.

[0102] The protruding body (114) extends from the housing body (112) and is connected to the first protruding projection (58) provided in the port portion (50). The protruding body (114) protrudes from the end of the housing body (112) and has a hole into which the first protruding projection (58) is inserted. Since the first protruding projection (58) protruding upward from the port portion (50) is inserted into the protruding body (114), the first protruding projection (58) and the housing portion (110) are connected.

[0103] FIG. 5 is a perspective view illustrating the main configuration of a length adjustment unit (100) according to one embodiment of the present invention, FIG. 6 is a perspective view illustrating a transmission gear unit (130) according to one embodiment of the present invention, and FIG. 7 is a cross-sectional view illustrating a screw bar (150) and a moving body unit (160) according to one embodiment of the present invention.

[0104] As illustrated in FIGS. 5 to 7, the linear drive unit (120) is installed in the housing unit (110) and can be modified in various ways within the technical concept of generating rotational power using electrical energy.

[0105] A linear drive unit (120) according to one embodiment of the present invention uses a stepper motor or a servo motor, and a drive gear (122) is connected to the output shaft of the linear drive unit (120). By operating the linear drive unit (120), the extension pipe unit (90) can be moved by a set distance.

[0106] The driving gear (122) is equipped with a gear on its outer surface and rotates by the operation of the driving gear (122) to rotate the transmission gear part (130).

[0107] The transmission gear unit (130) is equipped with a plurality of gears that rotate by receiving power from the linear drive unit (120), and various modifications are possible within the technical concept of rotating the driven gear (140). The transmission gear unit (130) according to one embodiment of the present invention includes a first transmission gear (132), a second transmission gear (134), a third transmission gear (136), and a fourth transmission gear (138).

[0108] The first transmission gear (132) rotates by meshing with the drive gear (122) connected to the linear drive unit (120), and the gear ratio changes. In one embodiment of the present invention, the first transmission gear (132) has two circular gears installed in succession that have the same rotational center axis but different outer diameters. The outer diameter of the circular gear meshed with the drive gear (122) in the first transmission gear (132) is larger than the outer diameter of the circular gear meshed with the second transmission gear (134). Therefore, the second transmission gear (134) rotates at a reduced speed compared to the first transmission gear (132).

[0109] The second transmission gear (134) rotates by meshing with the first transmission gear (132), and the gear ratio changes. In one embodiment of the present invention, the second transmission gear (134) has two circular gears installed in succession with the same rotational center axis and different outer diameters. In the second transmission gear (134), the outer diameter of the circular gear meshed with the first transmission gear (132) is larger than the outer diameter of the circular gear meshed with the third transmission gear (136). Therefore, the third transmission gear (136) rotates at a reduced speed compared to the second transmission gear (134).

[0110] The third transmission gear (136) rotates by meshing with the second transmission gear (134) and changes the gear ratio, thereby rotating the fourth transmission gear (138). The fourth transmission gear (138) rotates by meshing with the third transmission gear (136) and the driven gear (140) and changes the gear ratio.

[0111] The driving gear (122) can rotate by directly meshing with the driven gear (140), and a plurality of gears can be installed between the driving gear (122) and the driven gear (140) to transmit the power of the driving gear (122) to the driven gear (140).

[0112] When power is applied to the linear drive unit (120), the power of the linear drive unit (120) is transmitted in the order of the first transmission gear (132), the second transmission gear (134), the third transmission gear (136), and the fourth transmission gear (138), and then rotates the driven gear (140).

[0113] The driven gear (140) is a gear that rotates by meshing with the transmission gear section (130). In one embodiment of the present invention, the driven gear (140) is meshed with the fourth transmission gear (138), and the rotational center of the driven gear (140) is the same as the rotational center of the screw bar (150). The screw bar (150) is connected to the center of the driven gear (140).

[0114] The screw bar (150) has a rotational center similar to that of the driven gear (140) and is in the shape of a rod connected to the driven gear (140), with a spiral gear formed on its outer side. Therefore, when the driven gear (140) rotates by the transmission gear section (130), the screw bar (150) also rotates together.

[0115] The movable body part (160) is provided with an inner hole part (164) into which a screw bar (150) is inserted, and various modifications are possible within the technical concept of moving in a straight direction inside the housing part (110) by the rotation of the screw bar (150). The movable body part (160) according to one embodiment of the present invention includes a first movable body (162) and a second movable body (166).

[0116] The first movable body (162) is a square bar shape installed inside the housing part (110) in a state where rotation is restricted and linear movement is possible. The shape of the first movable body (162) is not limited to a square bar, and within the technical concept of being installed inside the housing part (110) in a state where rotation is restricted, it can be modified into various shapes including a triangular prism. An inner hole part (164) for coupling with a screw bar (150) is formed inside the first movable body (162).

[0117] When a male screw is formed in the screw bar (150), a female screw is formed in the inner hole portion (164), so when the screw bar (150) rotates, the first movable body (162), whose rotation is restricted, can only move in a straight direction along the housing portion (110).

[0118] The second movable body (166) connects the first movable body (162) and the rod member (170) and extends in the shape of a circular bar. One end of the second movable body (166) is connected to the first movable body (162), and the other end of the second movable body (166) extends to the outside of the housing part (110) and is connected to the rod member (170).

[0119] The rod member (170) can be modified in various ways within the technical concept of extending from the movable body part (160) and connecting to the extension pipe part (90). A rod member (170) according to one embodiment of the present invention includes a rod body (172) and a rod connecting projection (174).

[0120] The rod body (172) is a rod-shaped structure extending from the movable body. According to one embodiment of the present invention, the rod body (172) is cylindrical in shape and extends from the movable body portion (160). The rod body (172) is located on the outside of the housing portion (110), and the end of the rod body (172) is connected to the rod connecting projection (174).

[0121] The rod connecting projection (174) extends from the rod body (172) and is connected to the second protruding projection (95) protruding from the extension pipe section (90). The rod connecting projection (174) has a hole into which the second protruding projection (95) is inserted.

[0122] As illustrated in FIG. 1, the display (200) is installed on the front of the front case (10) and conveys various information to the user through the screen. The display (200) can notify the user of changes in low frequency. The display (200) uses a liquid crystal panel and outputs the operating status of the frequency variable speaker (1) through the screen.

[0123] FIG. 8 is a perspective view showing the state in which the first adjustment unit (500) according to one embodiment of the present invention is installed, FIG. 9 is a perspective view showing the state in which the length adjustment unit (100) according to one embodiment is operated and the extension pipe unit (90) and the first adjustment unit (500) are moved, FIG. 10 is a perspective view showing the state in which the first adjustment unit (500) according to one embodiment of the present invention is operated.

[0124] As illustrated in FIGS. 8 to 10, the first adjustment unit (500) is located inside the mounting space (74) formed between the front case (10) and the rear case (70) and is installed at the end of the extension conduit unit (90). The first adjustment unit (500) can be modified in various ways within the technical concept of adjusting the open cross-sectional area of ​​the inner passage (97) provided in the extension conduit unit (90) by means of a plate shape that rotates by receiving electrical energy. The first adjustment unit (500) according to one embodiment of the present invention includes a fixed bracket (510), a first driving unit (520), a rotating member (530), and a rotating support unit (540).

[0125] The fixed bracket (510) is fixed to the extension pipe section (90) and can be modified in various ways within the technical concept of supporting the first driving section (520). Additionally, the fixed bracket (510) is fixed to the movable body section (160). The fixed bracket (510) according to one embodiment of the present invention includes a first fixed bracket (512) and a second fixed bracket (514).

[0126] The first fixing bracket (512) is located in the mounting space (74) formed between the front case (10) and the rear case (70). Additionally, the first fixing bracket (512) is fixed to one side (right side according to FIG. 8) of the extension pipe section (90). The first fixing bracket (512) according to one embodiment of the present invention is a panel with an "L" shape and is fixed to the upper side of the extension pipe section (90).

[0127] The second fixed bracket (514) is installed in succession to the first fixed bracket (512) and has a space on its inner side for the first driving unit (520) to be seated. A guide hole is provided on the bottom surface of the second fixed bracket (514) for installing the first output shaft of the first driving unit (520). The first driving unit (520) uses a motor, and the second fixed bracket (514) has an inner space for the first driving unit (520) to be inserted.

[0128] The side of the second fixed bracket (514) having an inner space is open, and the first driving unit (520) is inserted into the side of the second fixed bracket (514) and mounted on the inside of the second fixed bracket (514).

[0129] The first drive unit (520) is fixed to the fixed bracket (510) and can be modified in various ways within the technical concept of supplying rotational power by receiving electrical energy. The first drive unit (520) according to one embodiment of the present invention uses a stepper motor capable of precise angle control and rotates the rotating member (530) to a set angle. The first drive unit (520) may also use a servo motor.

[0130] The first output shaft protruding outward from the first drive unit (520) is installed in a state where it is inserted into the guide hole.

[0131] The rotating member (530) is connected to the first output shaft (not shown) of the first driving unit (520), and can be modified into various shapes within the technical concept of adjusting the opening area of ​​the inner passage (97) provided in the movable body part (160) by the rotating operation. The rotating member (530) according to one embodiment of the present invention includes a rotating plate (532) and a rotating connecting part (534).

[0132] The rotating plate (532) has a shape corresponding to the end surface of the inner passage (97), and various modifications are possible within the technical concept of controlling the opening rate of the inner passage (97) by rotating motion. The rotating plate (532) according to one embodiment of the present invention is a circular plate, and the inner side of the inner passage (97) of the corresponding port part (50) also has a circular passage.

[0133] The shape of the rotating plate (532) can be changed by the shape of the inner passage (97). If the shape of the inner passage (97) has a rectangular cross-section, the rotating plate (532) is also formed in the shape of a rectangular plate. The rotating plate (532) rotates around the first output axis, and the inner passage (97) can be opened and closed or the degree of opening of the inner passage (97) can be adjusted by the rotational movement.

[0134] The rotary connecting part (534) protrudes from the side of the rotating plate (532) and extends in the vertical direction, and various modifications are possible within the technical concept of being connected to the first output shaft of the first driving part (520). The rotary connecting part (534) according to one embodiment of the present invention is in the shape of a pipe extending in the vertical direction and is fixed to the side of the rotating plate (532).

[0135] Since the first driving unit (520) uses a stepper motor, accurate rotation angle control is possible, and the opening rate of the inner passage (97) can be adjusted by the operation of the first driving unit (520). Low frequency can be adjusted by adjusting the open cross-sectional area of ​​the port unit (50).

[0136] The rotational support member (540) is fixed to the movable body member (160) and can be modified in various ways within the technical concept of rotatably supporting the upper and lower sides of the rotational member (530). The rotational support member (540) uses an oil-less bearing and serves to support and guide the rotation of the rotational connection member (534) which is the center of rotation. The rotational support member (540) according to one embodiment of the present invention includes a first bearing (542) and a second bearing (544).

[0137] The first bearing (542) is a ring-shaped bearing that rotatably supports the upper side of the rotating member (530) and is fixed to the end of the movable body part (160). The second bearing (544) is a ring-shaped bearing that rotatably supports the lower side of the rotating member (530) and is fixed to the end of the movable body part (160).

[0138] The first bearing (542) and the second bearing (544) are ring-shaped and are fixed to the end of the first conduit section (52) which forms a concave groove. The upper side of the rotational connection section (534) is inserted into the inner side of the first bearing (542), and the lower side of the rotational connection section (534) is inserted into the inner side of the second bearing (544). Accordingly, the rotating member (530) rotates around the rotational support section (540).

[0139] Hereinafter, the operating state of a frequency variable speaker (1) according to one embodiment of the present invention will be described in detail with reference to the attached drawings.

[0140] Sound generated from the main speaker (20) and the side speaker (30) is output toward the front of the front case (10). The sound output to the rear of the main speaker (20) and the sound output to the rear of the first speaker (32) are discharged to the outside of the frequency variable speaker (1) through the extension tube section (90) and the port section (50), thereby reinforcing the bass.

[0141] In addition, the sound output from the rear of the second speaker (34) remains inside the inner enclosure (60) which is sealed, thereby improving the sound quality of the second speaker (34).

[0142] A control unit installed inside the frequency-variable speaker (1) can determine the position of the moving body part (160) or the load member (170) by means of a sensor and calculate the position of the extension conduit part (90) based on this. Alternatively, since the measurement value of a sensor installed in the movement path of the extension conduit part (90) is transmitted to the control unit, the control unit can determine the position of the extension conduit part (90).

[0143] The measured length of the extension pipe section (90) protruding outward from the first pipe section (52) provided in the port section (50) is transmitted to the control section, and the measured low-frequency value generated from the frequency variable speaker (1) is also transmitted to the control section.

[0144] The control unit operates the length adjustment unit (100) by comparing the tuning frequency set by the user with the actual frequency. The length adjustment unit (100) is operated to move the extension pipe unit (90). When the linear drive unit (120) of the length adjustment unit (100) is operated to rotate the drive gear (122), the first transmission gear (132) engaged with the drive gear (122) rotates. The first transmission gear (132) rotates the second transmission gear (134), and the second transmission gear (134) rotates the third transmission gear (136). Then, the third transmission gear (136) rotates the fourth transmission gear (138), and the fourth transmission gear (138) rotates the driven gear (140).

[0145] As the screw bar (150) fixed to the driven gear (140) rotates, the movable body part (160) moves linearly inside the housing part (110). Since the rod member (170) connected to the movable body part (160) moves the second protruding projection (95), the extension pipe part (90) connected to the second protruding projection (95) moves along the longitudinal direction of the first pipe part (52), and the length of the pipe guiding the movement of air is adjusted.

[0146] A control unit built into the inner side of a frequency-variable speaker (1) calculates the difference between the frequency set by the user and the actual frequency and operates the length adjustment unit (100) to adjust the low frequency.

[0147] The frequency change value adjusted by the length adjustment unit (100) can be displayed through the display (200) or the user's smartphone app.

[0148] In addition, the control unit installed on the inside of the frequency variable speaker (1) can determine the rotation angle and position of the rotating member (530) by means of a sensor and calculate the opening area of ​​the inner passage (97) based on this.

[0149] In addition, the value of the low-frequency range generated by the frequency-variable speaker (1) is also transmitted to the control unit.

[0150] The control unit operates the first driving unit (520) by comparing the tuning frequency set by the user with the actual frequency. The rotating member (530) rotates by the rotational power of the first driving unit (520), and the opening rate of the inner passage (97) provided in the extension conduit (90) is adjusted by the rotation of the rotating member (530).

[0151] The frequency change value adjusted by the length adjustment unit (100) and the first adjustment unit (500) can be displayed through the display (200) or the user's smartphone app.

[0152] As illustrated in FIG. 9, when the frequency output through the port section (50) is set high, the first driving unit (520) is operated to increase the opening rate of the inner passage (97) provided in the port section (50).

[0153] The rotating member (530) is rotated by the operation of the first driving unit (520), and the rotating member (530) is positioned vertically with respect to the inner passage (97) provided at the entrance of the first conduit unit (52). Since the blockage of the inner passage (97) by the rotating member (530) is minimized, the opening area of ​​the inner passage (97) can be maximized, and the opening rate of the inner passage (97) is also increased.

[0154] The larger the open area of ​​the inner passage (97) that is not blocked by the rotating member (530), the higher the tuning frequency. Therefore, when the tuning frequency is set high, the first driving unit (520) is operated so that the rotating member (530) is perpendicular to the cross-section of the inner passage (97) formed at the entrance of the first conduit (52).

[0155] As illustrated in FIG. 10, when the frequency output through the port section (50) is set to a value in the low frequency range, the first driving unit (520) is operated to adjust the opening rate of the inner passage (97) provided in the port section (50) to the lower range.

[0156] The rotating member (530) is rotated by the operation of the first driving unit (520), and the rotating member (530) rotates in a direction that blocks the inner passage (97) provided at the entrance of the first conduit unit (52). At this time, the opening rate of the inner passage (97) by the rotating member (530) reaches between 0% and 29%.

[0157] Since most of the inner passage (97) is blocked by the rotating member (530), the tuning frequency becomes lower.

[0158] As illustrated in FIGS. 2 and 3, a frequency variable speaker (1) according to one embodiment of the present invention can structurally change the bass sound compared to a speaker with only a port (50) installed, so it can satisfy various tastes of users.

[0159] In addition, the frequency-variable speaker (1) has tuning frequencies for each area of ​​the inner passage (97) input into the control unit, and the low frequency output through the sensor can be measured. Therefore, when a user inputs a desired low frequency into the device, the control unit operates the first adjustment unit (500) accordingly to adjust the opening area of ​​the inner passage (97). When the opening rate of the inner passage (97) provided in the port unit (50) is adjusted, the value of the output low frequency is also adjusted, so that the user can obtain the desired output value.

[0160] Meanwhile, the current tuned frequency information can be received using the display (200) or the user's smartphone app, and the output frequency can also be changed.

[0161] The control unit can operate the length adjustment unit (100) and the first adjustment unit (500) simultaneously, and various modifications can be implemented, such as operating only one of them or changing the order of operation as needed.

[0162] FIG. 11 is a perspective view showing the state in which a second adjustment unit (600) according to one embodiment of the present invention is installed, and FIG. 12 is a perspective view showing the rear side of a port unit (50) in which the second adjustment unit (600) and the length adjustment unit (100) according to one embodiment of the present invention are installed.

[0163] As illustrated in FIGS. 11 and 12, a second control unit (600) is installed in the extension conduit section (90) to control the opening and closing rate of the inner passage (97). The second control unit (600) is installed in the extension conduit section (90) and moves toward the center of the inner passage (97) provided in the extension conduit section (90) or toward the outside of the extension conduit section (90) to control the open cross-sectional area of ​​the extension conduit section (90). The second control unit (600) according to one embodiment of the present invention is located inside the mounting space (74) formed between the front case (10) and the rear case (70) and is installed at the end of the port section (50) to control the opening area of ​​the inner passage (97).

[0164] A second control unit (600) according to one embodiment of the present invention includes a motor bracket (610), a second driving unit (620), an output gear (630), and an opening / closing gear unit (640).

[0165] The motor bracket (610) is fixed to the extension conduit section (90) and can be modified in various ways within the technical concept of supporting the second drive unit (620). According to one embodiment of the present invention, the motor bracket (610) is fixed near the free end of the extension conduit section (90). The motor bracket (610) surrounds the outside of the second drive unit (620) and is fixed to the outside of the first conduit section (52).

[0166] The second drive unit (620) is fixed to the motor bracket (610), and various types of drive devices can be used within the technical concept of supplying rotational power by receiving electrical energy. The second drive unit (620) according to one embodiment of the present invention uses a stepper motor, and an output gear (630) is connected to the second output shaft (622) of the second drive unit (620).

[0167] The second drive unit (620) rotates the output gear (630) to a set angle, and the opening / closing gear unit (640) engaged with the output gear (630) is operated to adjust the open cross-sectional area of ​​the inner passage (97).

[0168] The output gear (630) is connected to the second output shaft (622) of the second drive unit (620) and rotates together with the second output shaft (622), and a gear is formed along the outer circumference of the output gear (630). The output gear (630) is a gear in the shape of a circular plate.

[0169] FIG. 13 is an exploded perspective view of an opening / closing gear unit (640) according to one embodiment of the present invention.

[0170] As illustrated in FIGS. 11 and 13, the opening / closing gear section (640) is installed at the end of the extension conduit section (90) and is moved by a gear that rotates by engaging with the output gear (630) to adjust the open cross-sectional area of ​​the inner passage (97), allowing for various modifications within the technical concept.

[0171] An opening / closing gear unit (640) according to one embodiment of the present invention includes a fixed plate (650), a rotating plate (670), and a moving wing unit (680). The moving wing unit (680) is located between the fixed plate (650) and the rotating plate (670) and operates in an aperture manner to adjust the opening area of ​​the inner passage (97).

[0172] The fixed plate (650) is a ring-shaped plate fixed to the end of the extension pipe section (90), and has a hole connected to the inner passage (97) on the inside. The fixed plate (650) is fixed to the end of the extension pipe section (90) so that rotation is restricted. The fixed plate (650) according to one embodiment of the present invention includes a fixed body (652), a fixed hole (654), and a first guide projection (656).

[0173] The fixed body (652) is extended in a ring shape and fixed at the entrance of the extension conduit section (90). The inner side of the fixed body (652) is provided with a hole communicating with the inner passage (97), and the outer side of the fixed body (652) is formed in a circular shape.

[0174] A plurality of fixing holes (654) are formed along the circumference of the fixed body (652). The fixing holes (654) are holes into which the central projection (684) of the movable wing part (680) is inserted. A plurality of first guide projections (656) are installed along the circumferential direction of the fixed body (652). The first guide projections (656) have a projection shape that protrudes from the fixed body (652) toward the rotating plate (670).

[0175] The rotating plate (670) is installed in a position facing the fixed plate (650). The rotating plate (670) is a plate extended in a ring shape like the fixed plate (650), and a hole connected to the inner passage (97) is provided on the inside. On the outside of the rotating plate (670), a gear that meshes with the output gear (630) is provided, and a hole portion that guides the movement of the moving wing portion (680) is provided on the inside.

[0176] A rotating plate (670) according to one embodiment of the present invention includes a rotating body (672), a first guide hole portion (674), a second guide hole portion (676), and an outer gear (678).

[0177] The rotating body (672) is a plate shape extended in a ring shape, and a first guide hole portion (674) and a second guide hole portion (676) are provided on the inner side of the rotating body (672).

[0178] The first guide hole portion (674) forms an elongated hole into which the first guide projection (656) of the fixed plate (650) is inserted and caught. The first guide hole portion (674) is provided in multiple numbers along the circumferential direction and forms an elongated hole in the rotating body (672). The rotating plate (670) can rotate by the length of the first guide hole portion (674).

[0179] The outer gear (678) that rotates in mesh with the output gear (630) forms a gear along the outer circumference of the rotating body (672). When the output gear (630) rotates, the rotating plate (670) rotates together with the outer gear (678) that is meshed with the output gear (630).

[0180] The second guide hole portion (676) forms an elongated hole in the rotating body (672) into which the second guide projection (686) of the movable wing portion (680) is inserted. The first guide hole portion (674) forms an elongated hole along the circumferential shape, and the second guide hole portion (676) forms an elongated hole toward the inside of the rotating body (672) at an acute angle to the first guide hole portion (674). The second guide hole portion (676) may also be installed obliquely in a spiral shape toward the center of the rotating body (672).

[0181] The first guide hole section (674) limits the angle at which the rotating plate (670) rotates, and the second guide hole section (676) guides the moving wing section (680) to move toward the center of the inner passage (97) or to move away from the center of the inner passage (97).

[0182] FIG. 14 is an exploded perspective view showing a fixed plate (650) and a movable wing part (680) according to one embodiment of the present invention, FIG. 15 is a perspective view showing the state in which the movable wing part (680) is coupled to the fixed plate (650) according to one embodiment of the present invention, and FIG. 16 is a perspective view of an opening / closing gear part (640) according to one embodiment of the present invention.

[0183] As illustrated in FIGS. 14 to 16, the movable wing portion (680) is located between the fixed plate (650) and the rotating plate (670), and various modifications are possible within the technical concept of moving by the rotation of the rotating plate (670) to adjust the opening area of ​​the inner passage (97).

[0184] The movable wing portion (680) is provided with a central projection (684), and the central projection (684), which protrudes toward the fixed plate (650), is inserted into a hole provided in the fixed plate (650) to become the rotation center of the movable wing portion (680). Additionally, the movable wing portion (680) is provided with a second guide projection (686), and the second guide projection (686), which protrudes toward the rotating plate (670), is inserted into the second guide hole portion (676) to guide the movement of the movable wing portion (680).

[0185] A movable wing portion (680) according to one embodiment of the present invention includes a wing body (682), a central projection (684), and a second guide projection (686).

[0186] The wing body (682) is located between the fixed plate (650) and the rotating plate (670), and multiple wing bodies are installed along the fixed body (652). The wing body (682) is plate-shaped and forms an outer shape with three curved surfaces. The wing body (682) is formed in a shape that is approximately triangular, and the part corresponding to the vertex is installed facing the center of the inner passage (97).

[0187] The central projection (684) protrudes from the wing body (682) and is inserted into a fixing hole (654) provided in the fixing plate (650). Accordingly, the wing body (682) rotates around the central projection (684).

[0188] The second guide projection (686) protrudes from the wing body (682) and is inserted into the second guide hole portion (676) provided in the rotating plate (670). When viewed from the perspective of the wing body (682), the second guide projection (686) protrudes in a direction opposite to that of the center projection (684).

[0189] When the second guide projection (686) is inserted into the second guide hole (676) and the second guide projection (686) is moved by the rotation of the rotating plate (670), the wing body (682) moves together with the second guide projection (686) to adjust the opening area of ​​the inner passage (97).

[0190] To explain the operation of the first adjustment unit (500) in more detail, when the second driving unit (620) is operated to rotate the output gear (630) to a set angle, the outer gear (678) engaged with the output gear (630) rotates. The rotating plate (670) rotates together with the outer gear (678), and the second guide projection (686) located inside the second guide hole unit (676) also moves due to the rotation of the rotating plate (670).

[0191] When the second guide projection (686) moves inward toward the second guide hole portion (676), the second guide projection (686) catches on the end of the second guide hole portion (676), and the moving wing portion (680) blocks the inner passage (97) as much as possible. Since the entrance of the inner passage (97) provided in the extension conduit portion (90) is almost completely blocked, the open area of ​​the port portion (50) becomes smaller, and thus the value of the tuning frequency is lowered.

[0192] FIG. 17 is a perspective view illustrating a state in which the movable wing portion (680) according to one embodiment of the present invention is moved outward so that the opening and closing area of ​​the inner passage (97) is increased. As shown in FIG. 17, when the rotating plate (670) is rotated counterclockwise (based on FIG. 17), the first guide projection (656) is inserted into the first guide hole portion (674), thereby guiding the counterclockwise rotation of the rotating plate.

[0193] Additionally, the second guide projection (686) moves along the second guide hole (676) toward the outside of the rotating plate (670). Since the central projection (684) of the movable wing portion (680) is inserted into the fixed hole (654) of the fixed plate (650), each movable wing portion (680) rotates around the central projection (684). As the movable wing portion (680) rotates counterclockwise, the opening area of ​​the inner passage (97) gradually expands.

[0194] For example, when the rotating plate (670) rotates 5.3°, the movable wing part (680) rotates 15° around the central projection (684) to adjust the opening rate of the inner passage (97). The central projection (684) of the movable wing part (680) and the second guide projection (686) are installed at a set distance apart, and while the rotation of the fixed plate (650) connected to the central projection (684) is constrained, only the rotating plate (670) connected to the second guide projection (686) rotates. Accordingly, the movable wing part (680) provided in multiples opens the inner passage (97) by unfolding into an aperture shape.

[0195] FIG. 18 is a perspective view illustrating a state in which a moving wing portion (680) according to an embodiment of the present invention is moved outward so that the inner passage is maximally opened. As shown in FIG. 18, when the rotating plate (670) is additionally rotated in a counterclockwise direction (based on FIG. 18), the first guide projection (656) catches on the end of the rotating first guide hole portion (674), so the rotation of the rotating plate (670) is stopped.

[0196] Additionally, the second guide projection (686) moves along the second guide hole portion (676) toward the outside of the rotating plate (670) and catches on the end of the second guide hole portion (676). The moving wing portion (680) is further rotated counterclockwise to maximize the opening area of ​​the inner passage (97).

[0197] For example, when the rotating plate (670) rotates 10.6°, the moving wing part (680) rotates 30° around the central projection (684) and adjusts the opening rate of the inner passage (97).

[0198] FIG. 19 is a perspective view illustrating a state in which the length adjustment unit (100) according to one embodiment of the present invention is operated so that the extension pipe unit (90) and the second adjustment unit (600) are moved.

[0199] As illustrated in FIG. 19, when the length adjustment unit (100) is operated to move the extension conduit unit (90), the length of the extension conduit unit (90) protruding outward from the port unit (50) is changed, thereby changing the output low-frequency range.

[0200] FIG. 20 is a perspective view illustrating the state in which the second control unit (600) is operated according to one embodiment of the present invention.

[0201] As illustrated in FIG. 20, the second control unit (600) can be operated to change the low-frequency output by adjusting the opening area of ​​the inner passage (97) provided in the extension conduit (90).

[0202] As described above, the second adjustment unit (600) is operated to adjust the frequency value to be tuned to match the target frequency value set by the user, thereby adjusting the opening area of ​​the inner passage (97). When the second driving unit (620) is operated to rotate the opening / closing gear unit (640), the opening area of ​​the inner passage (97) is adjusted by the movement of the moving wing unit (680), so that the frequency of the sound output through the port unit (50) can be changed.

[0203] Meanwhile, the fixed plate (650), the rotating plate (670), and the moving wing (680) constituting the opening / closing gear unit (640) are installed inside a separate housing, so the moving wing (680) and the rotating plate (670) can be installed in a stacked shape in front of the fixed plate (650).

[0204] As described above, the invention can satisfy various consumer preferences by operating the length adjustment unit (100) and the first adjustment unit (500) or by operating the length adjustment unit (100) and the second adjustment unit (600) to adjust the low-frequency range using the port unit (50).

[0205] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration of the present invention were not explicitly described while explaining the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized. Explanation of the symbols

[0206] 1: Frequency-variable speaker 10: Front case 11: Front panel 12: Center hole area 13: Side hole area 17: Side panel 20: Main Speaker 30: Side Speaker 32: 1st Speaker 34: 2nd Speaker 50: Port section 52: First pipeline section 54: Second pipeline section 56: Port bracket 58: First protrusion 60: Internal enclosure 70: Rear case 72: Connection hole 74: Mounting space 80: Reinforcement part 82: Inner hole 90: Extension pipe section 95: Second protrusion 97: Internal passage 100: Length adjustment part 110: Housing part 112: Housing body 114: Protruding body 120: Linear drive unit 122: Drive gear 130: Transmission gear section 132: 1st transmission gear 134: 2nd transmission gear 136: 3rd transmission gear 138: 4th transmission gear 140: Driven gear 150: Screw bar 160: Movable body part 162: First movable body 164: Inner hole part 166: Second movable body 170: Rod member 172: Rod body 174: Rod connecting projection 200: Display 500: First control unit 510: Fixing bracket 512: First fixing bracket 514: Second fixing bracket 520: 1st drive unit 530: Rotating member 532: Rotating plate 534: Rotating connection part 540: Rotating support 542: First bearing 544: Second bearing 600: Second control unit 610: Motor bracket 620: Second drive unit 622: Second output shaft 630: Output gear 640: Opening / closing gear section 650: Fixed plate 652: Fixed body 654: Fixed hole 656: First guide projection 670: Rotating plate 672: Rotating body 674: First guide hole section 676: Second guide hole section 678: Outer gear 680: Movable wing section 682: Wing body 684: Central projection 686: Second guide projection

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