KR20140115013A - Diaphragm of Electrowetting Speaker Having Petal Pattern - Google Patents

Diaphragm of Electrowetting Speaker Having Petal Pattern Download PDF

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Publication number
KR20140115013A
KR20140115013A KR1020130029518A KR20130029518A KR20140115013A KR 20140115013 A KR20140115013 A KR 20140115013A KR 1020130029518 A KR1020130029518 A KR 1020130029518A KR 20130029518 A KR20130029518 A KR 20130029518A KR 20140115013 A KR20140115013 A KR 20140115013A
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South Korea
Prior art keywords
diaphragm
droplet
petal
pattern
speaker
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KR1020130029518A
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Korean (ko)
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심정보
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심정보
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Priority to KR1020130029518A priority Critical patent/KR20140115013A/en
Publication of KR20140115013A publication Critical patent/KR20140115013A/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/42—Combinations of transducers with fluid-pressure or other non-electrical amplifying means
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
    • H04R7/04—Plane diaphragms
    • H04R7/06—Plane diaphragms comprising a plurality of sections or layers
    • H04R7/08—Plane diaphragms comprising a plurality of sections or layers comprising superposed layers separated by air or other fluid
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R2499/00—Aspects covered by H04R or H04S not otherwise provided for in their subgroups
    • H04R2499/10—General applications
    • H04R2499/11—Transducers incorporated or for use in hand-held devices, e.g. mobile phones, PDA's, camera's

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)

Abstract

The present invention relates to a diaphragm of an electrowetting speaker for driving a diaphragm using an electrowetting effect of a droplet, wherein the diaphragm includes a petal pattern for providing a petal effect for fixing the droplet, And to prevent departure. The electrowetting loudspeaker diaphragm according to the present invention vibrates due to the surface tension of the liquid droplet which is changed by applying an electric field generated by a driving voltage in which the magnitude of the voltage changes according to an audio signal to the liquid droplet, Wherein at least a portion of the surface is in contact with the droplet, and the surface in contact with the droplet comprises a petal pattern providing a petal effect for fixing the droplet.

Description

[0001] The present invention relates to a diaphragm of Electrowetting Speaker Having Petal Pattern,

The present invention relates to an electrowetting loudspeaker diaphragm including a petal pattern. More particularly, the present invention relates to an electrowetting loudspeaker diaphragm for driving a diaphragm using an electrowetting effect of a droplet, The present invention relates to an electrowetting loudspeaker diaphragm including a petal pattern capable of preventing dropout of a liquid droplet by including a petal pattern provided thereto.

 Speakers are electric devices that generate sound by converting an audio signal into vibration of a diaphragm. The speaker is classified into a dynamic speaker, a piezoelectric speaker, and an electrostatic speaker according to the driving method of the diaphragm. can do.

The coaxial speaker 10 is a speaker for driving a diaphragm by electromagnetic force, and Fig. 1 shows a general coaxial speaker 10. When the driving current according to the audio signal is applied to the voice coil 11, the voice coil 11 is urged upward by the magnetic field of the magnet 13 and the electric field of the voice coil 11 to drive the diaphragm 14 upward do.

The coaxial speaker 10 is the most widely used speaker and is a speaker used as a micro speaker mounted on a mobile device because the driving current is not high. However, there is a problem that the speaker structure including the magnetic circuit and the vibration systems 11, 12, 14, and 15 is complicated, so that the miniaturization and thinning are limited and the production process is difficult to automate. Since the driving force is locally transmitted only to a certain region of the diaphragm 14 to which the bobbin 12 or the voice coil 11 is adhered, the linearity of the output sound is degraded and the vibration of the diaphragm 14, There is a problem that distortion occurs in the output sound due to interference. Finally, the magnet 13 providing the magnetic field is manufactured by using rare earth. The production cost of the coaxial type speaker 10 is increased due to the increase of the raw material price of rare earth.

The piezoelectric speaker 20 is a speaker for driving the diaphragm 22 using a change in shape of the piezoelectric body 21 according to the driving voltage. FIGS. 2A and 2B show a general piezoelectric speaker 20. The piezo-electric speaker 20 includes a piezoelectric body 21 disposed on an upper portion of a diaphragm 22 formed of a metal thin film. When a driving voltage corresponding to an audio signal is applied to the piezoelectric body 21, The diaphragm 22 vibrates up and down as shown in Figs. 2A and 2B to generate a negative pressure.

The piezoelectric speaker 20 is advantageous in downsizing and thinning because of its extremely simple structure, and its power consumption and heat generation are small because of a small driving voltage. However, the piezoelectric material 21 of the ceramic material is vulnerable to impact, which makes it difficult to use it in a mobile environment. In addition, since the weight of the diaphragm 22 and the piezoelectric body 21 is heavy, there is a problem that the low-frequency characteristic of the output sound is low, so that it is generally used as a buzzer for outputting only a sound of a specific frequency band.

The electrostatic speaker 30 is a speaker for driving the diaphragm 32 with an electric field, and FIGS. 3A and 3B show a typical single-ended single diaphragm-type electrostatic speaker 30. The electrostatic speaker 30 is a capacitor in which a fixed electrode (stator) 31 and a diaphragm 32 are opposed to each other. When a driving voltage corresponding to an audio signal is applied to the fixed electrode 31 and the diaphragm 32, 33 operate in such a manner that the diaphragm 32 is driven.

The electrostatic speaker 30 is also advantageous in size and thickness because the structure is extremely simple in the same manner as the piezoelectric speaker 20 and the linearity of the output sound is excellent because the driving force is uniformly transmitted to the entire diaphragm 30, (32) is extremely light in weight, which is advantageous in that the response characteristic is excellent. The electrostatic speaker 30 has been commercialized as an expensive music listening speaker by QUAD, Martin-Logan and Stax, which are acoustical speaker companies.

The greatest disadvantage of the electrostatic speaker 30 is that the dielectric 33 is used as the air having a very low dielectric constant to ensure free vibration of the diaphragm 32. Therefore, in order to generate the driving force of the diaphragm 32, It is necessary to apply a voltage. Due to such high voltage characteristics, the electrostatic speaker 30 is almost impossible to be applied in a mobile environment using a limited power source. An expensive transformer that generates a high voltage between the input terminal of the audio signal and the fixed electrode 31 is required even in a non-mobile environment, which increases the manufacturing cost of the electrostatic speaker 30 and increases the power consumption. The patent specification of Henk-Albert Hiensch's "Electrostatic Speaker System" (WO 2009/070004, published on June 4, 2009) In detail.

Sihong Ahn and Sergey Potapov, "The surface sound speaker using electrowetting" (Korean Patent Laid-Open No. 10-2009-0043707, 5.7) discloses an electrowetting speaker that drives a diaphragm using a shape change due to a change in the surface energy of a liquid due to application of an electric field, using electrowetting (electrowetting) characteristics of the droplet .

4A and 4B show the electrowetting phenomenon of the droplet 43. Fig. When a voltage is applied to the droplet 43, the surface tension with respect to the fixed electrode 41 changes. The height h 2 of the droplet 43 applied with the voltage shown in FIG. 4B becomes relatively low as compared with the height h 1 of the droplet 43 to which the voltage shown in FIG. 4A is not applied. The electrowetting phenomenon is mainly utilized in an electrowetting display field that replaces a liquid lens that changes the focal distance using the change in surface tension of the droplet 43 or an electronic ink having a slow reaction speed.

5A and 5B show an electrowetting speaker 50 using an electrowetting phenomenon. The droplet 53 positioned between the fixed electrode 51 and the diaphragm 52 remains attached to the diaphragm 52 by surface tension. The surface tension of the droplet 53 changes and the contact angle between the fixed electrode 51 and the droplet 53 changes as a result of application of a driving voltage according to an audio signal as shown in FIG. (52) toward the fixed electrode (51) to provide a driving force to the diaphragm (52).

The electrowetting speaker 50 can operate at a low voltage and maintains the merits of the conventional electrostatic speaker 30 as it is. Therefore, the electro-wetting speaker 50 can be easily miniaturized and thinned, is suitable for mass production through automation, It is expected to be able to replace the conventional coin type speaker 10, the piezoelectric type speaker 20 and the electrostatic type speaker 30 because it is linear and small in distortion.

However, due to the fluidity of the droplet 53 in an actual use environment, the electrowetting speaker 50 may be operated in an environment in which gravity continues to act as shown in FIG. 6, 7, the droplet 53 may be separated from the diaphragm 52 and the fixed electrode 51 and flow down or may be deflected to one side in a mobile environment where abrupt movement occurs. When the droplet 53 is completely deviated, the electrowetting speaker 50 loses its function. When the droplet 53 is tilted to one side, uneven vibration is generated in the diaphragm 52, . Therefore, in order to commercialize the electrowetting speaker 50, it is necessary to solve the problem of separating and separating the droplet 53.

In order to solve the above problems, the present invention provides an electrowetting loudspeaker diaphragm including a petal pattern according to the present invention, in which a diaphragm provides a petal effect for fixing a liquid droplet to a surface in contact with the liquid droplet The present invention aims at preventing deterioration of performance and loss of function of the electrowetting speaker by maintaining the liquid droplet stably even in an environment in which gravity continuously acts or in a mobile environment where sudden movement occurs.

The electrowetting loudspeaker diaphragm including the petal pattern according to the embodiment of the present invention can be formed by forming a petal pattern on the surface of the diaphragm through a commercialized surface treatment technique such as plasma surface treatment technique, electrochemical surface treatment technique, and nanoimprint surface treatment technique In order to facilitate the operation of the apparatus.

According to an aspect of the present invention, there is provided a diaphragm for use in an electrowetting speaker comprising a diaphragm and a liquid droplet contacting the diaphragm, wherein an electric field generated by a driving voltage, The surface contacting the liquid droplet is in a petal pattern that provides a petal effect that fixes the liquid droplet, the surface being in contact with the liquid droplet, And a control unit.

In an electrowetting loudspeaker diaphragm including a petal pattern according to an embodiment of the present invention, the petal pattern may be any one of a fine surface pattern of rose petals, a fine surface pattern of a petal of petals, and a fine surface pattern of a sunflower petal .

In an electrowetting loudspeaker diaphragm including a petal pattern according to an embodiment of the present invention, the petal pattern is formed by applying a plasma surface treatment to the surface of the diaphragm.

In an electrowetting loudspeaker diaphragm including a petal pattern according to an embodiment of the present invention, the petal pattern is formed by applying an electrochemical surface treatment to the surface of the diaphragm.

In an electrowetting loudspeaker diaphragm including a petal pattern according to an embodiment of the present invention, the petal pattern is formed by a method of nano-imprinting the petal pattern on the surface of the diaphragm.

In the electro-wetting speaker diaphragm according to the embodiment of the present invention, the diaphragm is a metal thin film, and the petal pattern is formed on a surface of the metal thin film in contact with the liquid droplet.

In an electrowetting loudspeaker diaphragm including a petal pattern according to an embodiment of the present invention, the diaphragm is an organic film including a metal layer on at least one side thereof, the metal layer is in contact with the liquid droplet, Is formed on a surface of the substrate facing the liquid droplet.

In an electrowetting loudspeaker diaphragm including a petal pattern according to an embodiment of the present invention, the diaphragm is an organic film including a metal layer on at least one side thereof, the organic film is in contact with the liquid droplet, And is formed on the surface of the organic film which is in contact with the droplet.

In an electrowetting loudspeaker diaphragm including a petal pattern according to an embodiment of the present invention, the diaphragm may further include a hydrophobic insulating layer on at least one side thereof, and the petal pattern may be formed on a surface of the hydrophobic insulating layer, Is formed.

An electrowetting loudspeaker diaphragm comprising a petal pattern according to the present invention includes a petal pattern that provides a petal effect that fixes the droplet to a surface in contact with the droplet, The liquid droplet stably maintains its position even in a mobile environment where an environment or a sudden movement occurs, thereby preventing deterioration of performance and loss of function of the electrowetting speaker.

The electro-wetting loudspeaker diaphragm including the petal pattern according to the embodiment of the present invention can be easily formed on the surface of the diaphragm by using the plasma surface treatment technique, the electrochemical surface treatment technique, the nano imprint surface treatment technique, Of the present invention.

1 is a configuration diagram showing a conventional coin type speaker.
FIG. 2A and FIG. 2B are diagrams showing the operation of a conventional piezoelectric speaker. FIG.
Figs. 3A and 3B are diagrams showing the operation of a conventional electrostatic speaker. Fig.
4A and 4B are diagrams showing electro-wetting phenomenon of droplets.
5A and 5B are diagrams showing the operation of a conventional electrowetting speaker.
6 is a configuration diagram showing a case where gravity acts on a conventional electrowetting speaker.
7 is a configuration diagram showing a case where a sudden movement occurs in a conventional electrowetting speaker.
8 is a configuration diagram of an electrowetting speaker including a diaphragm according to an embodiment of the present invention.
9 is a configuration diagram of an electrowetting speaker including a diaphragm according to another embodiment of the present invention.
10 is a configuration diagram of an electrowetting speaker including a diaphragm according to another embodiment of the present invention.
11A and 11B are diagrams showing a petal effect by a petal.
12 is a view showing a petal pattern;
13 is a sectional view of a diaphragm according to an embodiment of the present invention.
14 is a sectional view of a diaphragm according to another embodiment of the present invention;
15 is a sectional view of a diaphragm according to another embodiment of the present invention;
16 is a sectional view of a diaphragm according to another embodiment of the present invention.

Hereinafter, a diaphragm 120 of an electrowetting speaker 100 including a petal pattern according to the present invention will be described with reference to the drawings.

Figure 8 shows an electrowetting loudspeaker diaphragm 120 comprising a petal pattern 121 according to the present invention. 8 illustrates an electrowetting speaker 100 having a single diaphragm 120 and a fixed electrode 110 as a single-ended structure, the diaphragm 120 according to the present invention is limited only to this structure 9, instead of the fixed electrode 110 as a single-ended structure, an electrowetting speaker 200 having diaphragms 220 and 240 on both sides and a diaphragm 320 interposed therebetween Pull type electrowetting speaker 300 in which the fixed electrodes 310 and 350 are formed on the upper and lower sides of the electrowetting speaker 300, respectively. Hereinafter, for convenience of explanation, the electrowetting loudspeaker diaphragm 120 according to the present invention will be described, focusing on the embodiment of Fig. 8 in which the structure is the simplest.

The electrowetting loudspeaker diaphragm 120 according to the present invention is used in an electrowetting loudspeaker 100 including a diaphragm 120 and a droplet 130 in contact with the diaphragm 120. [ The electrowetting loudspeaker diaphragm 120 vibrates due to the surface tension of the droplet 130 changed by application of the electric field generated by the drive voltage whose magnitude varies according to the audio signal to the droplet 130, At least a portion of the surface is configured to abut the droplet (130). The droplet 130 may be in contact with a part of the surface of the diaphragm 120 as shown in FIG. 8, the droplet 130 may be in contact with the entire surface of one or both sides of the diaphragm 120, The droplets 130 of the diaphragm 120 may be in contact with a plurality of partial areas of the surface of the diaphragm 120.

The surface of the diaphragm 120 in contact with the droplet 130 is configured to include a petal pattern that provides a petal effect that fixes the droplet 130.

Artificial reproduction of biological microstructures such as plants, insects, and the like is being actively carried out. The petal effect is one of such biological microstructures. As shown in FIG. 11A, when the dew 420 is formed on the rose petal surface 410, even if the rose is inverted as shown in FIG. 11B, Which means the phenomenon of falling or falling. The cause of the petal effect was found to be a phenomenon in which the petal pattern 121 made of fine protrusions as shown in Fig. 12 formed on the surface of petals such as rose petals, horse mackerel, sunflower, etc. invades the surface of water and fixes moisture. The opposite phenomenon has been found in the Lotus lotus effect, in which the leaves of the lotus are not well-watered and fall down.

The paper describes the principle of petal effect, the structure of petal pattern (121), the structure of petal effect (121), and the structure of petal effect (121), such as Lin Feng et al., "Petal Effect: A Superhydrophobic State with High Adhesive Force" And the method of reproducing the artificial petal pattern 121 through the nanoimprinting in detail, detailed description of the petal effect and the patal pattern 121 will be omitted in the present patent specification.

The petal pattern 121 of the present invention may be implemented by any one of a fine surface pattern of rose petals, a fine surface pattern of a petal of petroglyphs, and a fine surface pattern of a sunflower petal, and the petal pattern 121 of the present invention is not limited thereto And a fine concavo-convex pattern capable of fixing moisture.

Examples of the method of forming the petal pattern include a plasma surface treatment method which intensifies a desired pattern on the surface of a target object through a corona discharge, an electrochemical surface treatment method or a method of using the "Petal effect: super- The nanoimprint method disclosed in US Pat.

Figs. 13 to 16 show the pattern 121 of the diaphragm 120 according to the type of the diaphragm 120. Fig.

13, a diaphragm pattern 121 is formed on a surface of the metal thin film 122 that is in contact with the droplet 130. In this embodiment, the diaphragm 120 is formed of a metal thin film 122 as shown in FIG.

Next, as shown in FIG. 14, the diaphragm 120 is an organic film 124 having a metal layer 123 formed on one side thereof by sputtering or plating, and the metal layer 123 is in contact with the droplet 130, The petal pattern 121 is formed on the surface of the metal layer 123 in contact with the droplet 130. [

Next, as shown in FIG. 15, the diaphragm 120 is an organic film 126 having a metal layer 125 formed on one side thereof by sputtering or plating, and the organic film 126 is in contact with the droplet 130 In an example, a petal pattern 121 is formed on a surface of the organic film 126 which is in contact with the droplet 130. [

16, in the embodiment in which the diaphragm 120 further includes a hydrophobic insulating layer 127 such as a Teflon coating layer on at least one side thereof, the surface of the hydrophobic insulating layer 127, which is in contact with the droplet 130 of the hydrophobic insulating layer 127, A pattern 121 is formed. In the embodiment of FIG. 16, the diaphragm 120 may be embodied as a metal thin film 122 as shown in FIG. 13 or organic films 123 and 126 including metal layers 124 and 125 as shown in FIG. 14 and FIG.

100: electrowetting speaker 110: fixed electrode
120: diaphragm 121: petal pattern
122: metal thin film 123, 126: organic film
124, 125: metal layer 127: hydrophobic insulating layer
130: droplet

Claims (9)

A diaphragm for use in an electrowetting speaker comprising a diaphragm and a droplet in contact with the diaphragm,
An electric field generated by a driving voltage varying in magnitude of a voltage according to an audio signal is oscillated by a surface tension of the liquid droplet which is changed by being applied to the liquid droplet,
At least a portion of the surface abuts the droplet,
Wherein the surface in contact with the droplet comprises a petal pattern providing a petal effect for securing the droplet. ≪ Desc / Clms Page number 13 >
The method according to claim 1,
Wherein the petal pattern is one of a fine surface pattern of rose petals, a fine surface pattern of a petal, a fine surface pattern of a sunflower petal.
The method according to claim 1,
Wherein the petal pattern is formed by applying a plasma surface treatment to the surface of the diaphragm.
The method according to claim 1,
Wherein the petal pattern is formed by applying an electrochemical surface treatment to the surface of the diaphragm.
The method according to claim 1,
Wherein the petal pattern is formed by a method of nano-imprinting the petal pattern on the surface of the diaphragm.
The method according to claim 1,
The diaphragm is a thin metal film,
Wherein the petal pattern is formed on a surface of the metal thin film that is in contact with the liquid droplet.
The method according to claim 1,
The diaphragm is an organic film including a metal layer on at least one side thereof,
Wherein the metal layer is in contact with the droplet,
Wherein the petal pattern is formed on a surface of the metal layer that is in contact with the liquid droplet.
The method according to claim 1,
The diaphragm is an organic film including a metal layer on at least one side thereof,
Wherein the organic film is in contact with the droplet,
Wherein the petal pattern is formed on a surface of the organic film that is in contact with the liquid droplet.
The method according to claim 1,
Wherein the diaphragm further comprises a hydrophobic insulating layer on at least one side thereof,
And the petal pattern is formed on a surface of the hydrophobic insulating layer that is in contact with the liquid droplet.
KR1020130029518A 2013-03-20 2013-03-20 Diaphragm of Electrowetting Speaker Having Petal Pattern KR20140115013A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113710037A (en) * 2021-09-16 2021-11-26 维沃移动通信有限公司 Cover plate assembly and electronic equipment

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113710037A (en) * 2021-09-16 2021-11-26 维沃移动通信有限公司 Cover plate assembly and electronic equipment

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