WO2005081580A1

WO2005081580A1 - Multi-way plate speaker system

Info

Publication number: WO2005081580A1
Application number: PCT/KR2005/000469
Authority: WO
Inventors: Ok-Jung Yoo
Original assignee: Jin Young Acoustic Co., Ltd.
Priority date: 2004-02-20
Filing date: 2005-02-21
Publication date: 2005-09-01
Also published as: KR20050082887A; KR100676422B1

Abstract

The invention relates to a multi-way plate speaker system cable of reproducing wide range sound source. The invented speaker system comprises a plurality of first vibration plate for reproducing mid and high range sound by direct driving of a voice coil and a second vibration plate for reproducing low range sound by the driving force of a plurality of magnetic circuit portion integrally connected thereto.

Description

[DESCRIPTION]

[INVENTION TITLE] MULTI-WAY PLATE SPEAKER SYSTEM

[Technical Field] The present invention relates, in general, to a muti- point drive type multi-way slim plate speaker system and, more particularly, to a muti-point drive type multi-way slim plate speaker system in which a plurality of vibration bodies each independently having sound reproduction capability are combined, so that a sound reproduction range is extended.

[Background Art] A conventional two-way speaker system has a form in which a plurality of speaker units independently having sound reproduction capability, such as a woofer and a tweeter, are installed in a wooden cabinet box. Furthermore, the conventional speaker system assigns and supplies Alternative Current (AC) electrical signals, which have varying frequencies, to the speaker units, using a network, that is, a passive type frequency filter. It is relatively difficult to make the outer size of the conventional speaker system slim. Furthermore, in the case where the size of the conventional speaker system is smaller than a predetermined size, it is impossible to extend the reproduced sound range to a low sound range. Furthermore, the conventional speaker system must use a network because a speaker unit for reproducing a high sound range is damaged if a large electrical signal is input into the speaker unit. The plate speaker was disclosed in International Publication No. WO 97/09846 (title of the invention: Panel Type Loudspeaker), by New Transducers Ltd. The construction of the conventional plate speaker is shown in FIG. 1. The conventional plate speaker includes a quadrangular frame 1 having an elastic damper, and a dispersion mode sound emission plate 2 is supported along the inner periphery of the damper. A transducer 4 is securely mounted on the plate at a predetermined location that is indicated by the variables, X and Y, or inside the plate. The coordinates of the location are calculated using a method that is disclosed in the invention filed by New Transducers Ltd. so that sound output is radiated by resonating the plate in such a way as to pass bending waves to the inside of the plate. The transducer 4 is driven by a signal amplifier 6, for example, an audio amplifier, which is connected thereto through a conductor 5. As in a conventional cone type speaker, the load of the amplifier and required power may be at a standard level. The sensitivity of the transducer is 86 ~ 88 db/watt in an indoor load state. Amplifier load impedance is generally 6 ohms, and processing power is 20 ~ 80 watts. In the case where a plate core and/or a surface portion are metal, the plate core and/or the surface portion function to absorb heat, so that processing power is improved because the transducer 4 can eliminate heat generated by the motor coil thereof. However, in the conventional plate speaker described above, sound distortion increases in proportion to the distance from a part to which the transducer is attached due to a plate resonance phenomenon, that is, the intrinsic resonance of a plate itself. Accordingly, the conventional plate speaker cannot reproduce clear sounds. Generally, the sound distortion increases excessively in proportion to the size of the plate or extension to a low sound range. For this reason, the conventional plate speaker is being used as a low price-oriented auxiliary speaker. Furthermore, the conventional plate speaker is problematic in that it is actually difficult to design to be less than 18 mm in total thickness. Furthermore, a multi-point drive type plate speaker is already well known and is configured in such a way as to operate a single vibration plate using a plurality of coils and magnetic circuits. Accordingly, the multi-point drive type plate speaker allows the implementation of sounds from a predetermined low sound range to a predetermined high sound range, but it is impossible to implement sounds ranging from a predetermined low sound range to a predetermined high sound due to a plate shaped vibration plate, the combined weight of the drive sources, and the weight of the vibration plate . As a result, the full-range sounds can be reproduced only when lower sounds in a low sound range and higher sounds in a high sound range are reproduced with the help of separate speakers.

[Detailed Description of the Invention] Disclosure of the Invention Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a multi-point drive type muli-way slim plate ^' speaker system, in which a second vibration plate, which is dedicated to low range sound reproduction and vibrated by the drive force of a plurality of magnetic circuit units integrated with each other, and a plurality of first vibration plates, which reproduce intermediate and high range sounds by directly driving voice coils, are combined, thus being capable of reproducing a wide range of sound. In order to accomplish the above object, the present invention provides a plate speaker system, including an exterior frame; a plurality of magnetic circuit units that are disposed at regular intervals, and that each include a yoke, a permanent magnet and a plate; a plurality of first vibration plates for high sound reproduction that correspond to the plurality of magnetic circuit units, respectively, and that are provided with voice coils; and a second vibration plate, an edge of which is connected to the exterior frame through an exterior damper and are connected to the magnetic circuit units through interior dampers, and that is configured to reproduce a low sound range by vibration of the magnetic circuit units. Preferably, the interior dampers are coupled to the outer sides of yokes of the magnetic circuit units, the interior dampers are integrated with interior frames, and the second vibration plate is coupled to the interior frames . Preferably, an auxiliary exterior damper for preventing the cancellation of low sounds is attached to a lower side of the exterior damper. Preferably, the exterior frame, the exterior damper, the second vibration plate, the interior frames, the interior dampers and the yokes are manufactured in a single body through a single injection molding process. Preferably, the second vibration plate is configured in such a way that a plurality of spaces is formed such that a section of the second vibration plate has a honeycomb shape. Preferably, the second vibration piste is separately manufactured such that an edge thereof i s coupled to the exterior damper integrated with the exterior frame, and a section of the exterior damper has a wave shape. Preferably, the plate speaker system further includes signal supplying means for supplying signals to the voice coils, the signal supply means being configured to connect the voice coils in series, in parallel or in series- parallel in such a way that main signal supply lines are disposed along both sides of the signal supply means, sub signal supply lines having a number identical to a number of the magnetic circuit units are placed inside the main signal supply lines, connection lines of the voice coils are coupled to the sub signal supply lines, and some of the sub signal supply lines are coupled to ^" the main signal supply lines .

Brief Description of the Drawings FIG. 1 is a view showing a conventional plate speaker system; FIG. 2 is a view showing a plate speaker system according to an embodiment of the present invention; FIG. 3 is a sectional view illustrating a speaker unit used for the plate speaker system according to the embodiment of the present invention; FIG. 4 is a sectional view showing a plate speaker system according to another embodiment of the present invention; FIG. 5 is a view illustrating a speaker unit used for the plate speaker system according to another embodiment of the present invention; FIG. 6 is a view illustrating the interior electrodes of the plate speaker system according to the present invention and the pattern thereof; and FIGS. 7a to 7c are views showing examples of connecting muti-point drive units in various forms using the interior electrodes of the plate speaker system according to the present invention.

[Best Mode for Carrying Out the Invention]

Embodiments of the present invention are described -in detail with reference to the accompanying drawings below. FIG. 2 is a view showing a plate speaker system according to an embodiment of the present invention, and FIG. 3 is a sectional view illustrating a speaker unit used for the plate speaker system according to the embodiment of the present invention. In FIG. 2, (a) is a partially exploded front view, and (b) is a longitudinal section. In the plate speaker system according to the present invention, a plurality of magnetic circuit units 18 are disposed at regular intervals as shown in FIG. 2. A second vibration plate 12 for reproducing low sounds is integrated with the magnetic circuit units 18 through an interior damper. The edge of the second vibration plate 12 is supported by an exterior frame 11 through an exterior damper 14. In this case, the interior damper and the exterior damper have elasticity. Meanwhile, first vibration plates 13 for reproducing high sounds are placed above the magnetic circuit units 18, and voice coils are attached to the first vibration plates 13. Accordingly, the first vibration plates 13 are vibrated by the interaction between the voice coils and the magnetic circuit units 18, and the second vibration plate 12 is vibrated by the vibration of the magnetic circuit units 18. In drawings, reference numerals 15, 16 and 17 indicate a duct for introducing echoes, a lower casing, and an upper casing, respectively. Reference numeral 19 indicates a power connection line for supplying power to each of the voice coils. The detailed construction of the power supply structure will be described with reference to FIG. 6 later. The detailed construction of the speaker unit used for the multi-point drive type plate speaker system is described with reference to FIG. 3 below. As shown in FIG. 3, the speaker unit includes a single magnetic circuit unit. The magnetic circuit unit includes a yoke 25, a permanent magnet 26 provided inside the yoke 25, and a plate 27 located on the permanent magnet 26 like a general magnetic circuit unit. A first vibration plate 28 for reproducing high sounds is installed above the magnetic circuit unit. A secondary suspension 29 that was presented in PCT Appl. No. PCT/KR 03/001755 (title of the invention: Micro Speaker having Dual Suspension) previously filed by the present inventor may be coupled to the first vibration plate 28. A voice coil 31 is attached to the lower portion of the first vibration plate 28. A first damper 30 is outwardly extended and integrated with the first vibration plate 28. The first damper 30 is fastened to an interior frame 23. Since the structure and operation of the magnetic circuit unit 18, the first vibration plate 28, the voice coil 30, the secondary order suspension 29 and the first damper 30 are described in PCT Appl. No. PCT/KR 03/001755 in detail, descriptions thereof are omitted below. In the present invention, the magnetic circuit unit, the first vibration plate, the voice coil and the first damper may be constructed as in a general micro speaker. The main characteristic of the present invention is that the second vibration plate 12 is coupled to the yoke 25 of the magnetic circuit unit 18. Accordingly, the second vibration plate 12 reproduces a low range sound using the vibration of the magnetic circuit unit 18. The interior frame 23 is disposed to be spaced apart from the yoke 25 of the magnetic circuit units 18 by a certain distance. The yoke 25 is integrated with the interior frame 23 by the interior damper 24. The second vibration plate 12 for low sound range reproduction is outwardly extended and is integrated with the interior frame 23. The edge of the second vibration plate 12 is fastened to the exterior frame 11. In this case, the second vibration plate 12 and the exterior frame 11 are connected to each other by the exterior damper 14. An auxiliary exterior damper 21 for preventing the cancellation of low sounds may be provided below the exterior damper 14. A lower casing 16 for protecting the spea-ker system is fastened to the lower end portion of the external frames 11. Electrode terminals for power input may be provided on the lower case 16. In FIG. 3, a reference numeral 2-2 indicates a main signal supply line for supplying signal^'s- to the speaker units. The main signal supply line 22 is- coupled with a connection line for supplying signals to the voice coil. In the present invention, the exterior fframe 11, the exterior damper 14, the second vibration p-Late 12, the interior frame 23, the interior frame 24 and the yoke 25 may be integrated into a single body through a sin<gle injection molding process. Accordingly, the exterior frame 11, the exterior damper 14, the second vibration plate 12, the second interior frame 23, the interior damper 24 and th-e yoke 25 are manufactured of polymer material. In the present invention described above, the second vibration plate 12 is indirectly vibrated by th& vibration of the magnetic circuits 18, so that the weight of the magnetic circuit unit 18, and the thickness of the second vibration plate 12 must be taken into account. In the present invention, the resonance frequency applied to the first vibration plate 13 is based on vibration force of the voice coil, and the resonance frequency is determined to be proportional to the stiffness of the interior damper 30 itself, and inversely proportional to the effective mass of the first vibration plate, the mass of the voice coils, the added mass resulting from the reaction of air, the equivalent mass that is the sum of the masses of an adhesive and the like. Furthermore, the resonance frequency is determined in consideration of the stiffness of the magnetic circuit unit 18, the interior damper 24 that supports the magnetic circuit unit 18, the^' exterior dampers 14, and the auxiliary exterior damper 21 used for controlling the entrance and exit of air, that is, the overall stiffness of the dampers 14, 21 and 24 that support the second vibration plate 12, the total weight of the second vibration plate, including added mass resulting from the reaction of an air corresponding to the effective vibration area of the second vibration plate. In this case, the first vibration plate 13 having a low relative mass and the second vibration plate 12 having a high relative mass implement different resonance regions. As a result, the phenomenon allows the sounds of separately different frequencies to be reproduced in one channel at the same time. That is, in the present invention, the second vibration plate is coupled with the plurality of magnetic circuit units 18, which are disposed at regular intervals, through the interior damper, and indirectly receives the drive force of the magnetic circuit units, so that a low sound region is reproduced. Furthermore, the first vibration plates, to which the voice coils corresponding in number to the number of the plurality of magnetic circuit units disposed at regular intervals are coupled, are placed above the magnetic circuit units, so that the first vibration plates are directly vibrated by the interaction between the magnetic circuit units and the voice coils. Accordingly, the present invention can reproduce sounds in different ranges at the same time without using 'a frequency dividing circuit. Furthermore, since the resonance frequency varies with the weight of the magnetic circuit unit, sounds in several ranges can be reproduced when the weights of the magnetic circuit units are properly adjusted. Referring to FIG. 3, the first vibration plate is molded to have a proper angle, so that even a higher sound range above the resonance frequency can be reproduced. In contrast, the second vibration plate dedicated to low sound reproduction is a plate type, so that it reproduces only frequencies in a certain range above the resonance frequency. Accordingly, from a low sound range to a predetermined intermediate sound range is reproduced by the second vibration plate that is dedicated to low sound reproduction, and from a predetermined intermediate sound range to a high sound range is reproduced by the first vibration plate that is dedicated to intermediate and high sound reproduction. FIG. 4 is a sectional view showing a plate speaker system according to another embodiment of the present invention, and FIG. 5 is a view illustrating a speaker unit used for the plate speaker system according to another embodiment of the present invention. The main characteristic of the second embodiment of the present invention is that the vibration plate having a honeycomb shaped sectional structure, which are separately constructed, is adopted as the second vibration plate to implement the relatively low distortion and linear characteristics of the low sound range. As shown in FIG. 5, a second vibration plate 41 is manufactured by forming a plurality of spaces 43 so that the section thereof has a honeycomb shape. The second vibration plate 41 is separately manufactured because it cannot be integrated with interior and exterior frames 11 and 23 through a single injection molding process unlike the second vibration plate of FIG. 2. When the second vibration plate 41 is separately manufactured, the section of an exterior damper 42 for fastening the second vibration plate 41 to the exterior frame 11 is configured to have a wave shape, as shown in FIG. 5. Meanwhile, the edge of the second vibration plate 41 is coupled to an exterior damper 42, and is fastened to the upper portion of the interior frame 23 that is integrated with a magnetic circuit near a magnetic circuit unit. In the second embodiment of the present invention described above, a yoke 25, an interior damper 24 and the interior frame 23 are integrated into a single body through an injection molding process. The exterior frame 11 and the exterior damper 42 are integrated into a single body. Furthermore, the second vibration plate 41 is separately manufactured, and is coupled to the exterior damper 42 and the interior frame 23. Components other than the above- described components are the same as those of the first embodiment of the present invention described in FIG. 2. FIG. 6 is a view illustrating the inner electrodes of the plate speaker system according to the present invention and the pattern thereof. In the present invention, main signal supply lines 50a and 50b are disposed along both sides of the speaker system in a longitudinal direction so as to supply power to the voice coils . A protrusion 52 is formed to connect the center regions of the main signal supply lines 50a and 50b, and depressions are formed on the end portion of the protrusion 52. Furthermore, sub signal supply lines 51a, 51b and 51c, which have a number identical to the number of provided magnetic circuit units, are positioned inside the main signal supply lines 50a and 50b. Preferably, center sub signal supply lines, which are adjacent to each other, are connected into a single body, and are formed such that they can be soldered to the ends of the protrusion 52 that is formed to connect the center of the main signal supply liens. Furthermore, projections 53 are formed on upper and lower sub signal supply lines 51a, respectively so as to be soldered and connected to the main signal lines, and depressions are formed on the main signal supply lines corresponding to the projection 53. FIGS. 7a to 7c are views showing examples of connecting muti-point drive units in various forms using the interior electrodes of the plate- speaker system according to the present invention. In the drawings, parts indicated by circles are parts connected by soldering. As shown in the drawings, a plurality of speaker units are connected in series or in parallel, or connected in series and parallel depending upon which parts are soldered. Meanwhile, the speaker system according to the present invention may be manufactured in various forms, such as a circle, an oval and a quadrangle, according to necessity. Furthermore, although, in the present invention, the interior frame has been described as being coupled with the interior damper, and the second vibration plate has been described as being fixedly coupled to the interior frame, the second vibration plate may be directly coupled to the interior damper. Such a modification will be apparent to those skilled in the art based on the technical spirit of the invention. Accordingly, the scope of the invention should be defined by the appended claims rather than the detailed description.

[Industrial Applicability] As described above, the present invention is configured in such a way that the plurality of magnetic circuit units are disposed at regular intervals, the first vibration plates for high sound reproduction are installed so as to respectively correspond to the magnetic circuit units, and the second vibration plate for low sound reproduction is connected to the magnetic circuit units through the dampers, so that a wide range of sound can be reproduced even through a single signal channel, and a ultra slim and ultra large sized speaker system can be manufactured due to the reduction of its total height. Furthermore, the present invention has a reduced the number of components to be assembled, resulting in a reduced number of manufacturing processes and reduced use of adhesive.

Claims

[Claims]

[Claim 1] A plate speaker system, comprising: an exterior frame; a plurality of magnetic circuit units that are disposed at regular intervals, and that each include a yoke, a permanent magnet and a plate; a plurality of first vibration plates for high sound reproduction that correspond to the plurality of magnetic circuit units, respectively, and that are provided with voice coils; and a second vibration plate, an edge of which is connected to the exterior frame through an exterior damper and are connected to the magnetic circuit units through interior dampers, and that is configured to reproduce a low sound range by vibration of the magnetic circuit units .

[Claim 2] The plate speaker system according to claim 1, wherein the interior dampers are coupled to outer sides of yokes of the magnetic circuit units, the interior dampers are integrated with interior frames, and the second vibration plate is coupled to the interior frames.

[Claim 3] The plate speaker system according to claim 1 or 2, wherein an auxiliary exterior damper for preventing cancellation of low sounds is attached to a lower side of the exterior damper.

[Claim 4] The plate speaker system according to claim 2, wherein the exterior frame, the exterior damper, the second vibration plate, the interior frames, the interior dampers and the yokes are manufactured in a single body through a single injection molding process.

[Claim 5] The plate speaker system according to claim 2, wherein the second vibration plate is configured in such a way that a plurality of spaces is formed such that a section of the second vibration plate has a honeycomb shape .

[Claim 6] The plate speaker system according to claim 5, wherein the second vibration plate is separately manufactured such that an edge thereof is coupled to the exterior damper integrated with the exterior frame, and a section of the exterior damper has a wave shape. [Claim 7] The plate speaker system according to claim 2, further comprising: signal supplying means for supplying signals to the voice coils, the signal supply means being configured to connect the voice coils in series, in parallel or in series-parallel in such a way that main signal supply lines are disposed along both sides of the signal supply means, sub signal supply lines having a number identical to a number of the magnetic circuit units are placed inside the main signal supply lines, connection lines of the voice coils are coupled to the sub signal supply lines, and some of the sub signal supply lines are coupled to the main signal supply lines .