JP2011151673A - Acoustic generation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acoustic generation apparatus which is thinned and generates sound of a sufficient volume in a simple configuration. <P>SOLUTION: The acoustic generation apparatus comprises: two substrates 2 and 3 which are two opposed substrates and in which at least one side of each of the substrates is formed to be conductive; an inter-substrate gap securing member 11 for securing a spatial gap between the opposed substrates; and an acoustic generation trigger 6 which is disposed between the opposed substrates and has a charging property. An electric field generated between opposed conductive sides 4 and 5 moves the acoustic generation trigger from one substrate to the other substrate, to generate sound. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sound generator used to generate sound, and more particularly to a sound generator capable of being thinned.

  2. Description of the Related Art Conventionally, speakers having various configurations are known as sound generating devices used for generating sound. Among such speakers, in the system using magnetism, it is necessary to use components such as magnets and coils, and there is a limit to reducing the thickness. In addition, the method using the piezoelectric ceramic can achieve a relatively thin thickness, but is expensive because the piezoelectric ceramic is used.

  Conventionally, an electrostatic speaker is known as an example of a speaker that can solve these problems and can be thinned (see, for example, Patent Document 1).

JP 2009-17337 A

  According to the electrostatic speaker described in Patent Document 1, a speaker that can be thinned can be obtained. However, in the electrostatic speaker described in Patent Document 1, a voltage corresponding to the sound desired to be generated is applied between the electrodes, and one of the vibrating electrodes is vibrated by the suction force generated between the electrodes to generate sound. Therefore, there is a problem that the volume is insufficient. In addition, the electrostatic speaker described in Patent Document 1 has a problem that it is expensive because of the large number of constituent members and a complicated structure, such as the use of a large number of thin film transistors (TFTs).

  An object of the present invention is to solve the above-described problems, and to provide a sound generator that can be thinned and can generate a sound having a sufficient volume with a simple configuration.

  The acoustic generator according to the present invention is two substrates facing each other, in which at least one surface of each substrate is conductively formed and a space gap between the substrates facing each other is secured. An inter-substrate gap securing member and an acoustic generation trigger having charging properties disposed between opposing substrates, and the acoustic generation trigger is moved to one side by an electric field generated between the opposing conductive surfaces. The sound is generated by moving from one substrate to the other substrate.

  As a preferred example of the sound generator of the present invention, the sound generation trigger is a particle having charging property or a fiber having charging property, and the inter-substrate gap securing member is used as a member for securing the inter-substrate gap. A partition for securing the gap and sealing the sound generation trigger in a predetermined space between the opposing substrates is provided so as to surround at least the periphery of the predetermined space, and between the opposing substrates surrounded by the partition In the predetermined space, a spacer for ensuring a space gap between the opposing substrates is further provided, the spacer is provided in a rib shape, and a cell structure is formed in the predetermined space between the opposing substrates together with the partition walls, and the acoustic The generation trigger is disposed in the cell, and the two substrates on which at least one surface is formed to be conductive are configured flexibly. A sound generation drive voltage waveform generation device that generates a voltage having a voltage waveform corresponding to the sound generation trigger drive voltage, and the drive voltage generated by the sound generation drive voltage waveform generation device Applying to the conductive surface, the two substrates as insulating substrates, the conductive surface as a conductive film formed on one surface of each of the two insulating substrates, and the conductive film of at least one substrate as Have been divided into a plurality of regions.

  According to the present invention, two substrates that are opposed to each other, wherein at least one surface of each substrate is conductively formed, and between the substrates for securing a space gap between the opposed substrates. A gap securing member and a sound generation trigger having charging properties disposed between opposing substrates, and the sound generation trigger is separated from one substrate by an electric field generated between the opposing conductive surfaces. By moving to the other substrate to generate sound, it is possible to obtain a sound generator that can be thinned and can generate high-volume sound with a simple configuration.

  As a preferred example of the present invention, the sound generation trigger is a particle having charging property or a fiber having charging property, so that a better sound can be generated. Furthermore, as a preferred embodiment of the present invention, as a member for securing the gap between the substrates, at least a predetermined partition wall for securing the gap between the opposed substrates and sealing the sound generation trigger in a predetermined space between the opposed substrates is used. A space provided between the opposing substrates surrounded by the partition walls, a spacer for ensuring a space gap between the opposing substrates, and a spacer provided in a rib shape; At the same time, a cell structure is formed in the predetermined space between the opposing substrates, and the sound generation trigger is disposed in the cell, so that it is possible to prevent uneven distribution of particle groups in the opposing space between the substrates. Furthermore, as a preferred example of the present invention, the flexible construction of the sound generator itself can be achieved by flexibly configuring two substrates on which at least one surface is made conductive. In addition, as a preferred example of the present invention, a sound generation drive voltage waveform generation device that generates a voltage having a voltage waveform corresponding to the sound to be generated as a drive voltage of the sound generation trigger is provided. By applying the generated drive voltage to the conductive surface of the counter substrate, a desired sound can be generated more suitably. Further, as a preferred example of the present invention, two substrates are used as insulating substrates, conductive surfaces are formed as conductive films formed on one surface of each of the two insulating substrates, and a plurality of conductive films are provided on at least one substrate. By dividing the area, the position where the sound is generated can be made variable, and further, the individual sound can be generated from the individual area.

It is a conceptual diagram for demonstrating an example of the sound generator of this invention. (A), (b) is a figure which shows the partial cross section of an apparatus, in order to demonstrate an example of the movement of the particle group used as the acoustic trigger in the acoustic generator of this invention, respectively. (A), (b) is a figure which shows the partial cross section of an apparatus, in order to demonstrate the other example of the movement of the particle group used as the acoustic trigger in the acoustic generator of this invention, respectively. (A), (b) is a figure for demonstrating an example of the voltage waveform applied to the electroconductive surface of the board | substrate in the acoustic generator of this invention, respectively. It is a figure which shows the partial cross section of an apparatus, in order to demonstrate the other suitable example of the sound generator of this invention. It is a conceptual diagram for demonstrating the further another suitable example of the sound generator of this invention. (A)-(d) is a figure for demonstrating an example which each divides | segments the electrically conductive film provided as an electroconductive surface in the acoustic generator of this invention. It is a figure for demonstrating an example of a structure of the sound generator of this invention. It is a figure for demonstrating the other example of a structure of the sound generator of this invention. It is a figure for demonstrating the further another example of a structure of the sound generator of this invention. It is a figure for demonstrating the further another example of a structure of the sound generator of this invention. (A)-(i) is a figure for demonstrating the relationship between the partition and the spacer in the acoustic generator of this invention, respectively.

  FIG. 1 is a conceptual diagram for explaining an example of the sound generator of the present invention. In the sound generator 1 of the present invention shown in FIG. 1, reference numeral 2 denotes an upper first panel substrate, 3 denotes a lower second panel substrate, and 4 denotes an entire first inner surface of the first panel substrate 2. 1 is a conductive surface, 5 is a second conductive surface disposed on the entire inner surface of the second panel substrate 3, 6 is a positively or negatively charged sound generation trigger (shown here are charged particles), It is. In the sound generator 1 of the present invention, the sound generating trigger 6 having charging property is disposed in the facing space 7 facing the first panel substrate 2 and the second panel substrate 3 facing each other, and the first conductive surface 4 is disposed. The sound generation trigger 6 is moved by an electric field generated between the conductive surfaces by applying a voltage from the power source 8 between the second conductive surface 5 and the second conductive surface 5 to generate sound. Here, the first panel substrate 2 and the second panel substrate 3 are insulating substrates, and the first conductive surface 4 and the second conductive surface 5 are provided on one surface thereof, respectively. The first panel substrate 2 and the second panel substrate 3 may be conductive substrates.

  Next, referring to FIGS. 2 (a), 2 (b), 3 (a), 3 (b) and 4 (a), 4 (b), the movement of the sound generation trigger in the sound generation apparatus of the present invention is performed. A mechanism for generating sound will be described. In the examples shown in FIGS. 2A and 2B and FIGS. 3A and 3B, the same members as those in the example shown in FIG.

  FIGS. 2A and 2B are views showing partial cross sections of the device in order to explain an example of the movement of the sound generation trigger in the sound generation device of the present invention. In the example shown in FIGS. 2A and 2B, the sound generation trigger 6-1 configured as a particle group including positively charged particles is used. Then, as shown in FIG. 2 (a), the first conductive surface 4 is negative and the second conductive surface 5 is positive, so that the sound generation is configured as a particle group including positively charged particles. The trigger 6-1 moves to the first panel substrate 2 side. Also, as shown in FIG. 2 (b), the first conductive surface 4 is positive and the second conductive surface 5 is negative, so that the sound generation is configured as a particle group including positively charged particles. The trigger 6-1 moves to the second substrate 2 side. When the sound generation trigger moves and collides with the first panel substrate 2 or the second substrate 3, it is assumed that the first panel substrate 2 or the second substrate 3 vibrates to generate sound.

  FIGS. 3A and 3B are views showing partial cross sections of the device in order to explain another example of the movement of the sound generation trigger in the sound generation device of the present invention. In the example shown in FIGS. 3A and 3B, an acoustic generation trigger 6-1 configured as a particle group including positively charged particles and an acoustic generation trigger 6 configured as a particle group including negatively charged particles are used. Two types, 2 and 2, are used as sound generation triggers. Then, as shown in FIG. 3 (a), the first conductive surface 4 is negative and the second conductive surface 5 is positive, so that sound generation is configured as a particle group including positively charged particles. The trigger 6-1 moves to the first panel substrate 2 side, and the sound generation trigger 6-2 configured as a particle group including negatively charged particles moves to the second substrate 3 side. Further, as shown in FIG. 3 (b), the first conductive surface 4 is positive, and the second conductive surface 5 is negative, so that the sound generation is configured as a particle group including positively charged particles. The trigger 6-1 moves to the second substrate 3 side, and the sound generation trigger 6-2 configured as a particle group including negatively charged particles moves to the first panel substrate 2 side. When two kinds of sound generation triggers move and collide with the first panel substrate 2 and the second substrate 3, and the first panel substrate 2 and the second substrate 3 vibrate to generate sound. I guess.

  FIGS. 4A and 4B are diagrams for explaining an example of a voltage waveform applied to the conductive surface of the substrate in the acoustic generator of the present invention. The example shown in FIG. 4A shows an example of an analog waveform, and the example shown in FIG. 4B shows an example of a pulse waveform. In the sound generator of the present invention, both the analog waveform shown in FIG. 4A and the pulse waveform shown in FIG. 4B can be used. By changing the size and frequency of the waveform in the analog waveform, In the pulse waveform, the pitch, volume, rhythm, etc. can be arbitrarily changed by changing the waveform size, pulse interval, pulse width, and the like.

  Next, with reference to FIG. 5, FIG. 6, and FIG. 7 (a)-(d), the other suitable example in the sound generator of this invention is demonstrated. In the examples shown in FIGS. 5, 6, and 7 (a) to 7 (d), the same members as those shown in FIG. Moreover, although the example shown in FIGS. 5 and 6 shows an example in which one type of sound generation trigger 6 is used, two or more types of sound generation triggers can be used.

  FIG. 5 is a diagram showing a partial cross section of the device for explaining another preferred example of the sound generator of the present invention. The example shown in FIG. 5 shows an example in which spacers 11 are formed in a rib shape in the facing space 7 between the first panel substrate 2 and the second substrate 3 to form, for example, a lattice cell structure. . Then, by enclosing an almost equal amount of the sound generating trigger 6 for each cell structure formed by the rib-shaped spacer 11, the sound generating device can be placed against a wall, placed on a flat surface, or any other method. In addition, it is possible to prevent the uneven distribution of the sound generation trigger in the space between the substrates, and to generate a uniform sound over the entire surface of the apparatus.

  FIG. 6 is a conceptual diagram for explaining still another preferred example of the sound generator of the present invention. In the example shown in FIG. 6, the power supply 8 shown in FIG. 1 includes a sound generation drive voltage waveform generation device 21 that generates a voltage having a voltage waveform corresponding to the sound to be generated as a drive voltage of the sound generation trigger, and generates sound. The drive voltage generated by the drive voltage waveform generator 21 is applied between the first conductive surface 4 and the second conductive surface 5. The sound generation drive voltage waveform generation device 21 includes a sound source 22 and an amplifier 23. As the sound source 22, a microphone, MP player, PC, television, game machine, or the like can be used. The amplifier 23 is an electric signal amplifier, and may be equipped with a sound quality correction function configured by a digital signal processor (DSP) or the like. When the sound generation trigger has a threshold voltage characteristic, it does not respond to a minute voltage, and thus correction is particularly necessary. Also, by converting to a pulse waveform, it is possible to effectively generate a sound even in a sound generation trigger having a threshold value. When converting to a pulse waveform, delta-sigma modulation or the like can be used.

  FIGS. 7A to 7D are diagrams for explaining an example of dividing a conductive film provided as a conductive surface in the acoustic generator of the present invention. In the example shown in FIG. 7A, an example in which the conductive surface 4 (5) is not divided is used. In the example shown in FIG. In the example shown in FIG. 7C, the conductive surface 4 (5) is divided into multiple parts, and in the example shown in FIG. 7D, the conductive surface 4 (5) is divided into upper and lower parts. In addition, an example in which an image corresponding to a sound generated in each divided region is printed and pasted corresponding to the divided region is shown. As shown in FIGS. 7B to 7D, the conductive surface is divided, and a drive voltage is applied to each conductive surface separately so that the sound generation trigger can be driven separately for each region. Then, the sound generation position can be changed. If it is not necessary to devise dynamic driving and reduce the number of amplifier outputs, the conductive surface may be divided only on one panel substrate side. As shown in FIG. 7B, a stereo speaker can be easily constructed by dividing it into left and right, and it is possible to further finely divide and control the sound generation point more finely as shown in FIG. 7C. As shown in FIG. 7D, a combined effect can be realized in combination with a fixed image or an image displayed on a display device.

  According to the above-described sound generator of the present invention, since it can be constituted by the first panel substrate 2 and the second panel substrate 3 which are arranged in close proximity to each other, the thickness can be reduced. Actually, a thin sound generator with a thickness of 0.29 mm could be obtained. Further, since the sound is generated by causing the sound generation trigger to collide with the panel substrate, it is possible to generate a sound having a sufficient volume with a simple configuration. Furthermore, the generation of sound in the range of about 1.5 octaves has been confirmed.

  Next, an example of the configuration of the sound generator of the present invention will be described with reference to FIG. 8, FIG. 9, FIG. 10, and FIG. In the example shown in FIGS. 8 to 11, the same members as those in the example shown in FIG. Moreover, in the example shown in FIGS. 8-11, the example using two types, the positively charged black particle 6B-1 and the negatively charged black particle 6B-2, as the sound generation trigger 6 is shown.

  8-11 is a figure for demonstrating an example of a structure of the sound generator of this invention, respectively. In the example shown in FIG. 8, the first panel substrate 2 and the second panel substrate 3, both of which are flat and have a conductive surface, are placed with the conductive surface on the inside by a spacer 11 that secures the inter-substrate spacing. An example is shown in which oppositely arranged parallel, positively charged black particles 6B-1 and negatively charged black particles 6B-2 are arranged between substrates. In this example, the arrangement of the spacers 11 is arbitrary, and the spacers 11 may be in the form of ribs or dots, and cells can be formed in the shape of ribs as shown in FIG. 8, but the cells need not be formed.

  In the example shown in FIG. 9, the first panel substrate 2 and the second panel substrate 3, both of which are stepped and have conductive surfaces, are secured by spacers 11 that serve as partition walls that secure the inter-substrate spacing and partition the space. In this example, the conductive surfaces are arranged in parallel and facing each other, and positively charged black particles 6B-1 and negatively charged black particles 6B-2 are arranged between the substrates. In this example, the partitioning method and arrangement of the spacer 11 are free. Further, in this example, the stepped shape gradually increases from the left side and gradually decreases on the right side with respect to the cell shown in the center. In this example, the frusto-conical shape having a convex center part is used, so that the generated sound is easily propagated in the direction of 360 degrees, so that an effect of generating a realistic sound can be obtained.

  In the example shown in FIG. 10, the staircase-shaped first panel substrate 2 and the flat plate-like second panel substrate 3 both having conductive surfaces serve as partition walls that secure a space between the substrates and partition the space. In this example, the spacers 11 are arranged in parallel and facing each other with the conductive surface facing inward, and the positively charged black particles 6B-1 and the negatively charged black particles 6B-2 are arranged between the substrates. In this example, the partitioning method and arrangement of the spacer 11 are free. In this example, the shape of the first panel substrate 2 is a stepped shape that gradually increases from the left side to the cell shown in the center and gradually decreases on the right side. In this example, the center portion has a frustoconical shape and the moving distance of the acoustic trigger at the center portion is increased, so that the generated sound can easily propagate in the 360 degree direction, and at the center portion. Since a louder sound can be generated, an effect of generating a realistic sound can be obtained.

  In the example shown in FIG. 11, both the rigid first panel substrate 2 and the rigid second panel substrate 3 having the same curvature and a conductive surface are secured between the substrates. An example is shown in which spacers 11 serving as partition walls that partition the space are arranged in parallel and facing each other with the conductive surface facing inward, and positively charged black particles 6B-1 and negatively charged black particles 6B-2 are arranged between the substrates. . In this example, the partitioning method and arrangement of the spacer 11 are free. Further, in this example, a flat panel substrate having a fixed curvature is used. However, a similar structure can be obtained by flexing two opposing panel substrates and bending the structure shown in FIG. It is done. In this example, spacer ribs are formed according to the curvature of the panel, and this curved state is fixed, so the rigid panel substrate that can obtain a curved structure with a rigid panel substrate and the sound quality that can be obtained with a flexible panel substrate Since they are slightly different, it is possible to obtain the effect that both can be selected depending on the sound quality to be obtained.

  Next, with reference to FIG. 12 (a)-(i), the relationship between the partition and the spacer in the sound generator of this invention is demonstrated. In the example shown in FIGS. 12A to 12I, a space gap between the opposing substrates is secured in a predetermined space between the opposing substrates surrounded by the partition wall 12 for shielding the sound generation trigger placement region from the external environment. The example which provided further the spacer 11 to perform is shown.

  FIG. 12A shows an example in which rib-shaped spacers 11 are provided in a discontinuous lattice shape in a predetermined space surrounded by the partition walls 12. FIG. 12B shows an example in which dot-like spacers 11 are regularly provided in a predetermined space surrounded by the partition walls 12. FIG. 12C shows an example in which the dot spacers 11 are irregularly provided in a predetermined space between the opposing substrates surrounded by the partition walls 12. FIG. 12D shows an example in which rib-like spacers 11 are provided in a continuous staggered pattern in a predetermined space between opposing substrates surrounded by partition walls 12. FIG. 12E shows an example in which rib-shaped spacers 11 are provided in a continuous lattice shape in a predetermined space surrounded by the partition walls 12. FIG. 12 (f) shows an example in which a continuous lattice-like rib-like spacer 11-1 and dot-like spacer 11-2 are provided in a predetermined space surrounded by the partition walls 12. FIG. 12G shows an example in which rib-shaped spacers 11 are provided in a predetermined space surrounded by the partition walls 12 in a stripe shape in the vertical direction. FIG. 12 (h) shows an example in which a continuous rib-shaped spacer 11-3 and a discontinuous rib-shaped spacer 11-4 are provided in a predetermined space surrounded by the partition wall 12. FIG. 12 (i) shows an example in which a continuous rib-shaped spacer 11-3 and a discontinuous rib-shaped spacer 11-4 are provided in a predetermined space surrounded by the partition walls 12. In any example, by providing the spacer 11 in the predetermined space surrounded by the partition wall 12, it is possible to obtain an effect that the position can be prevented from being unevenly distributed every time the arranged sound generation trigger moves. it can.

  Next, each member which comprises the sound generator of this invention is demonstrated.

  The substrate used as the panel substrate may or may not be transparent, and may or may not be flexible. Furthermore, it may be a flat plate, a curved flat plate, or a stepped uneven plate. Examples of the substrate material include polymer materials such as polyethylene terephthalate, polyethylene naphthalate, polyethersulfone, polyethylene, polycarbonate, polyimide, and acrylic, glass, quartz, hard plastic, and metal. The thickness of the substrate is preferably 2 μm to 5000 μm, more preferably 5 μm to 2000 μm. If it is too thin, it will be difficult to maintain the strength and the spacing uniformity between the substrates, and if it is thicker than 5000 μm, it will not be thin.

  When the panel substrate is made insulative, the conductive film provided on the inner surface of the panel substrate includes metals such as aluminum, silver, nickel, copper, and gold, indium tin oxide (ITO), zinc-doped indium oxide (IZO), Conductive metal oxides such as aluminum doped zinc oxide (AZO), indium oxide, conductive tin oxide, antimony tin oxide (ATO), conductive zinc oxide, polyaniline, polypyrrole, polythiophene, poly (3,4-ethylenedioxythiophene) Examples include conductive polymers such as -poly- (styrenesulfonate) (PEDOT: PSS), which are appropriately selected and used. If the panel substrate is a conductive substrate such as a metal substrate, its surface can be used as a conductive surface. In order to produce a conductive film, the above exemplified materials are formed into a thin film on a panel substrate by sputtering, vacuum deposition, CVD (chemical vapor deposition), coating, or the like, or a metal foil (for example, rolled copper). And a method of laminating a conductive agent in a solvent or a synthetic resin binder and applying the mixture onto the panel substrate. In addition, the thickness as a electrically conductive film should just ensure electroconductivity, and 0.01 micrometer-10 micrometers, Preferably it is provided in 0.05 micrometer-10 micrometers.

When forming ribs (also called spacers) that secure the gap between the substrates, the two-rib method in which ribs are formed after the ribs are formed on both opposing substrates and the one-rib method in which ribs are formed only on one substrate are considered. It is done. In the present invention, any method is preferably used. The ribs may be provided continuously or intermittently. Moreover, the cell which accommodates a sound generation trigger by partitioning with a rib can also be formed.
The cells formed from these ribs are exemplified by a square shape, a triangular shape, a line shape, a circular shape, a hexagonal shape, and a stepped octagonal shape as viewed from the substrate plane direction, and the arrangement is exemplified by a lattice shape, a honeycomb shape, or a mesh shape. Is done.
Examples of the rib forming method include a mold transfer method, a screen printing method, a sand blast method, a photolithography method, and an additive method. Any of these methods can be suitably used for the information display panel of the present invention, and among these, a photolithography method using a resist film and a mold transfer method are suitably used.
If it is a dot-like spacer, spacer particles can be arranged as dots to ensure a gap between substrates. In this case, the spacer particles can be distributed and arranged in the region surrounded by the partition walls on the substrate.

  The sound generation trigger has a charging property that can be driven by an electric field. If necessary, the resin as the main component can contain a charge control agent, an inorganic additive, and the like. Examples of resins, charge control agents, and other additives will be given below.

  Examples of the resin include urethane resin, urea resin, acrylic resin, polyester resin, acrylic urethane resin, acrylic urethane silicone resin, acrylic urethane fluororesin, acrylic fluororesin, silicone resin, acrylic silicone resin, epoxy resin, polystyrene resin, styrene Acrylic resin, polyolefin resin, butyral resin, vinylidene chloride resin, melamine resin, phenol resin, fluororesin, polycarbonate resin, polysulfone resin, polyether resin, polyamide resin and the like can be mentioned, and two or more kinds can be mixed. In particular, acrylic urethane resin, acrylic silicone resin, acrylic fluororesin, acrylic urethane silicone resin, acrylic urethane fluororesin, fluororesin, and silicone resin are suitable from the viewpoint of controlling the adhesive force with the substrate.

  The charge control agent is not particularly limited. Examples of the negative charge control agent include salicylic acid metal complexes, metal-containing azo dyes, metal-containing oil-soluble dyes (including metal ions and metal atoms), and quaternary ammonium salt systems. Examples thereof include compounds, calixarene compounds, boron-containing compounds (benzyl acid boron complexes), and nitroimidazole derivatives. Examples of the positive charge control agent include nigrosine dyes, triphenylmethane compounds, quaternary ammonium salt compounds, polyamine resins, imidazole derivatives, and the like. In addition, metal oxides such as ultrafine silica, ultrafine titanium oxide, ultrafine alumina, nitrogen-containing cyclic compounds such as pyridine and derivatives and salts thereof, various organic pigments, resins containing fluorine, chlorine, nitrogen, etc. are also charged. It can also be used as a control agent.

  Examples of inorganic additives include titanium oxide, zinc white, zinc sulfide, antimony oxide, calcium carbonate, lead white, talc, silica, calcium silicate, alumina white, cadmium yellow, cadmium red, cadmium orange, titanium yellow, Examples include bitumen, ultramarine blue, cobalt blue, cobalt green, cobalt violet, iron oxide, carbon black, manganese ferrite black, cobalt ferrite black, copper powder, and aluminum powder.

  The spacer for securing the inter-substrate gap can be formed in a rib shape to be a rib for partitioning the inter-substrate space into cells. Depending on the arrangement of the ribs formed in this case, a completely enclosed cell or an incompletely enclosed cell can be obtained. The cells can be arranged in a lattice shape, a honeycomb shape, a mesh shape, or the like. The cross-sectional shape of the cell may be any polygon such as a quadrangle, triangle, or hexagon, a circle, an ellipse, a racetrack, or a combination of a plurality of shapes. From the viewpoint that the sound generation trigger can be easily moved, a shape having no corners is preferable. From the two points, a square with rounded corners and a hexagon with rounded corners are preferable.

  It is not essential to form a cell, and there may be no cell. Also in this case, it is necessary to secure a space between the two substrates, and a spacer for securing the gap between the substrates is arranged. Dot spacers and partition walls such as spherical spacers, columnar spacers, and rib-shaped spacers can be arranged regularly or randomly.

  Spacers for securing the gap between the substrates and for blocking the space where the sound generation trigger is disposed from the external environment are formed in a rib shape as a partition, and are disposed so as to surround the space between the substrates. It is preferable that a sealing material is disposed around the partition wall so that moisture does not enter from the external environment into the space in which the sound generation trigger is disposed. This is because the chargeability of the sound generation trigger is easily affected by moisture and affects its drivability.

  The gap between the substrates is determined as appropriate so that the sound generation trigger disposed between the substrates can be easily moved. When the sound generation trigger is a particle, an interval of at least twice the particle diameter is secured. In such a case, it is preferable to secure an interval having a fiber diameter that is twice or more.

  When the acoustic trigger is a particle, it is composed of one type of particle, or it is a composite particle with a structure in which another particle is fixed to the particle surface, or a multilayered structure of two or more layers in which the particle surface is coated with another material Or particles. When the acoustic trigger is a fiber, it is composed of one type of fiber, or is composed of multiple types of fibers, or is a composite fiber in which the fiber surface is coated with particles, or the fiber surface is coated with another material. It can be a multi-layer fiber having a structure or more. In the case of fibers, short fibers having a small difference between the fiber diameter and the fiber length are preferred because the mobility is enhanced.

The sizes of the individual sound generation triggers may be uneven, but it is preferable that they are aligned because they are easy to move. When the sound generation trigger is particles, the particle size distribution Span represented by the following formula is set to less than 5 and preferably less than 3 with respect to the particle size distribution.
Span = (d (0.9) −d (0.1)) / d (0.5)
(However, d (0.5) is a numerical value expressing the particle diameter in μm that 50% of the particles are larger than this and 50% is smaller than this, and d (0.1) is a particle in which the ratio of the smaller particles is 10%. (Numerical value expressed in μm, and d (0.9) is a numerical value expressed in μm for a particle diameter of 90% or less.)
By keeping Span within a range of 5 or less, the size of each particle is uniform, and movement as a uniform display medium becomes possible.
Furthermore, regarding the particle size when using different types of particles as an acoustic trigger, the average particle size of the particles having the smallest average particle size with respect to the average particle size d (0.5) of the particles having the largest average particle size among the used particles. The ratio of the diameter d (0.5) is preferably 10 or less. Even if the particle size distribution Span is reduced, particles with different charging properties move in opposite directions. By making each other's particle size the same, each other's particles can easily move in the opposite direction. This is preferred and this is the range.
The particle size distribution and particle size of the display medium particles can be obtained from a laser diffraction / scattering method or the like. When laser light is irradiated onto particles to be measured, a light intensity distribution pattern of diffracted / scattered light is spatially generated, and this light intensity pattern has a corresponding relationship with the particle diameter, so that the particle diameter and particle diameter distribution can be measured. . Here, the particle size and particle size distribution in the present invention are obtained from a volume-based distribution. Specifically, using a Mastersizer2000 (Malvern Instruments Ltd.) measuring instrument, particles are introduced into a nitrogen stream, and the attached analysis software (software based on volume-based distribution using Mie theory) The diameter and particle size distribution can be measured.

  Hereinafter, an actual example will be described.

(Preparation of positively charged sound generating trigger particles)
60 parts by weight of methyl methacrylate monomer (Kanto Chemical Reagent) and 40 parts by weight (about 25 mol%) of ethylene glycol dimethacrylate (Wako Pure Chemical Reagent) as a polyfunctional monomer having a plurality of polymerization reactive groups in one molecule 3 parts by weight of a nigrosine compound (Bontron N07: manufactured by Orient Chemical) as a charge control agent for charging and 5 parts by weight of carbon black (special black: manufactured by Degussa) as a black pigment are dispersed by a sand mill (acrylic and methacrylic). ) After dissolving 5 parts by weight of resin-hydrocarbon resin block copolymer (Modiper F600: manufactured by NOF Corporation), a solution containing 2 parts by weight of lauryl peroxide (Perroyl L: manufactured by NOF Corporation) was dissolved in the interface. Sodium polyoxyethylene alkyl ether sulfate as activator LATEMUL E-118B (manufactured by Kao) is suspended in purified water to which 0.5% is added, polymerized, filtered and dried, and then average particle size 9 using a classifier (MDS-2: Nippon Pneumatic Industry). A group of positively charged black particles of 2 μm was obtained.

(Preparation of negatively charged sound generating trigger particles)
100 parts by weight of polymethylpentene polymer (TPX-R18: made by Mitsui Chemicals), 100 parts by weight of titanium dioxide (Taipaque CR-90: made by Ishihara Sangyo Co., Ltd.) as a colorant, and phenol-based condensation as a negative charge control agent 5 parts by weight of the product (Bontron E89: manufactured by Orient Chemical Co., Ltd.) was melt-kneaded with a twin-screw kneader and finely pulverized with a jet mill (Lab Jet Mill IDS-LJ type: Nippon Pneumatic Co., Ltd.). MDS-2: Nihon Numatic Kogyo Co., Ltd., classified and melt spheronized using a melt spheronizer (MR-10: Nihon Numatic Kogyo Co., Ltd.), with an average particle size of 9.5 μm Negatively charged white particles were obtained.

<Example 1>
A cell of length 300 μm × width 300 μm × height 50 μm in a space between the substrates in which two glass substrates with a thickness of 100 nm ITO film (thickness: 700 μm) face each other and the gap between the substrates is maintained at 50 μm. Is arranged in a matrix, and the positively charged sound generation trigger prepared in the cell is filled so that the volume occupancy in the cell is 25%, and the sound generation device having the configuration shown in FIG. 2 is manufactured. When assembled in the configuration shown in FIG. 6, sound could be generated.

<Example 2>
A cell of length 300 μm × width 300 μm × height 50 μm in a space between the substrates in which two glass substrates with a thickness of 100 nm ITO film (thickness: 700 μm) face each other and the gap between the substrates is maintained at 50 μm. 3 are arranged in a matrix, and the positively charged sound generation trigger and the negatively charged sound generation trigger prepared in the cell are combined in equal volumes so that the volume occupancy in the cell is 25%. When the sound generator having the configuration shown in FIG. 6 was produced and assembled in the configuration shown in FIG. 6, it was possible to generate sound.

<Example 3>
Two 100 nm thick polyethylene terephthalate substrates with an ITO film (PET substrate, thickness: 125 μm) facing each other on the ITO film forming surface and holding the gap between the substrates at 50 μm, 300 μm in length × 300 μm in width × high A 50 μm cell is arranged in a matrix, and a positively charged sound generation trigger prepared in the cell is filled so that the volume occupancy in the cell is 25%. Was fabricated and assembled into the configuration shown in FIG. 6, it was possible to generate sound.

<Example 4>
Two 100 nm thick polyethylene terephthalate substrates with an ITO film (PET substrate, thickness: 125 μm) facing each other on the ITO film forming surface and holding the gap between the substrates at 50 μm, 300 μm in length × 300 μm in width × high A cell having a thickness of 50 μm is arranged in a matrix, and the positively charged sound generation trigger and the negatively charged sound generation trigger prepared in the cell are filled so that the volume occupation ratio in the cell is 25%. When the sound generator having the configuration shown was fabricated and assembled into the configuration shown in FIG. 6, it was possible to generate sound.

  The sound generation device of the present invention includes two substrates having at least one surface formed to be conductive, and a sound generation trigger that is a particle having charging property or a fiber having charging property. The sound generation trigger is disposed in a space between the substrates facing each other with the conductive surface facing inward, and the sound generation trigger is moved to one substrate by an electric field generated between the opposite conductive surfaces. Since the sound can be generated by moving from one to the other substrate, it is possible to achieve a thin structure and a sufficient sound volume. Therefore, it can be made flexible as necessary to provide a flexible flat speaker. Further, it can be formed into a curved surface shape that matches the shape of the place to be mounted, and can be a convex curved speaker, a concave curved speaker, a wave speaker, or a staircase speaker.

DESCRIPTION OF SYMBOLS 1 Sound generator 2 1st panel board | substrate 3 2nd panel board | substrate 4 1st electroconductive surface 5 2nd electroconductive surface 6 Sound generation trigger 6-1 Positively chargeable sound generation trigger 6-2 Negative charge property Sound generation trigger 6B-1 Positively charged black particles 6B-2 Negatively charged black particles 7 Opposite space 8 Power supply 11 Spacer for securing gap between substrates 12 Bulkhead 21 Sound generating drive voltage waveform generator 22 Sound source 23 Amplifier

Claims (8)

  Two opposing substrates, at least one surface of each substrate being conductively formed, an inter-substrate gap securing member for securing a spatial gap between the opposing substrates, And an acoustic generation trigger having charging properties disposed between opposing substrates, and the acoustic generation trigger is moved from one substrate to the other by an electric field generated between the opposing conductive surfaces. And generating sound.   The sound generation device according to claim 1, wherein the sound generation trigger is a charged particle or a charged fiber.   As the inter-substrate gap securing member, a gap for securing the gap between the opposing substrates and sealing the sound generation trigger in a predetermined space between the opposing substrates is surrounded at least around the predetermined space. The sound generator according to claim 1, wherein the sound generator is provided as described above.   The sound generator according to claim 3, further comprising a spacer for ensuring a space gap between the opposing substrates in a predetermined space between the opposing substrates surrounded by the partition walls.   5. The sound generation according to claim 4, wherein the spacer is provided in a rib shape, a cell structure is formed in the predetermined space between the opposing substrates together with the partition, and the sound generation trigger is disposed in the cell. apparatus.   The sound generator according to any one of claims 1 to 5, wherein the two substrates on which the at least one surface is made conductive are configured flexibly.   A drive voltage waveform generation device for sound generation that generates a voltage having a voltage waveform corresponding to a sound to be generated as a drive voltage of the sound generation trigger, and the drive voltage generated by the drive voltage waveform generation device for sound generation is It applies to the electroconductive surface of a counter substrate, The sound generator of any one of Claims 1-6 characterized by the above-mentioned.   The two substrates are insulating substrates, the conductive surface is a conductive film formed on one surface of each of the two insulating substrates, and the conductive film of at least one substrate is divided into a plurality of regions. The sound generator according to any one of claims 1 to 7.