Patent Description:
In a field of manufacturing electronic devices, an ultrasonic atomization apparatus is used in some cases. In the field of the electronic device manufacturing, the ultrasonic atomization apparatus atomizes a solution by using ultrasonic waves that are oscillated from an ultrasonic vibrator, and sends out the atomized solution to the outside by using transfer gas. When the source solution mist transferred to the outside is sprayed onto a substrate, a thin film for the electronic device is formed on the substrate.

Various solvents are used for the source solution used in the film formation, and in order to prevent erosion of the ultrasonic vibrator, a double chamber method, in which the source solution and the ultrasonic vibrator do not come into contact with each other, is used. In the double chamber method, in order to separate the ultrasonic vibrator and the source solution, a separator cup for accommodating the source solution is used separately for a water tank provided with the ultrasonic vibrator in its bottom surface. The separator cup is required to allow transmission of ultrasonic waves; however, a part of the ultrasonic waves is reflected. Note that an ultrasonic wave conveyance solvent is accommodated in the water tank.

One example of the ultrasonic atomization apparatus employing the double chamber method described above is an atomization apparatus disclosed in <CIT>.

Other examples of ultrasonic atomization apparatuses are known from <CIT>, <CIT>, <CIT>, <CIT>, and <CIT>. <CIT> discloses an ultrasonic atomization apparatus as specified in the preamble of claims <NUM> and <NUM>.

When ultrasonic waves from the ultrasonic vibrator provided in the bottom surface of the water tank enter (impinge on) the bottom surface of the separator cup through the ultrasonic wave conveyance solvent being an inert liquid, transmission waves and reflected waves are generated. The transmission waves transmit through the bottom surface of the separator cup to enter the source solution, and the reflected waves travel toward the bottom surface of the water tank.

In order to entirely obtain the transmission waves without generating the reflected waves, constituent materials having the same acoustic impedance need to be used as the constituent materials of the ultrasonic wave conveyance solvent and the separator (the bottom surface thereof). However, it is practically extremely difficult to have the acoustic impedances of both of the constituent materials completely match each other, and reflected waves are inevitably generated.

The reflected waves are radiated toward the bottom surface side of the water tank. Thus, along with reception of the reflected waves, the water tank (the bottom surface thereof) may be melted or the ultrasonic vibrator provided in the bottom surface of the water tank may have a failure, which is a cause of reducing the life of the ultrasonic atomization apparatus. Thus, there is a problem in that a conventional ultrasonic atomization apparatus has poor durability.

The present invention has an object to solve the problem as described above and provide an ultrasonic atomization apparatus with enhanced durability.

An ultrasonic atomization apparatus according to a first aspect of the present invention includes the features specified in claim <NUM>. An ultrasonic atomization apparatus according to a second aspect of the present invention includes the features specified in claim <NUM>.

In the ultrasonic atomization apparatus according to the first and second aspects of the present invention, the separator cup and the plurality of ultrasonic vibrators are provided to satisfy the reflected wave avoidance condition and the plurality of ultrasonic wave absorption members or ultrasonic wave reflection members are provided in the plurality of reflected wave reception regions.

As a result, in the ultrasonic atomization apparatus according to the first and second aspects of the present invention, negative influence such as failure caused by the fact that the ultrasonic vibrators receive the bottom surface-reflected waves does not occur. Consequently, durability can be enhanced.

These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

<FIG> is an explanatory diagram schematically illustrating a configuration of an ultrasonic atomization apparatus <NUM> being a first embodiment not encompassed by the wording of the claims but useful for understanding the invention.

As illustrated in <FIG>, the ultrasonic atomization apparatus <NUM> includes a container <NUM>, an ultrasonic vibrator <NUM> being an atomizer, an internal hollow structure body <NUM>, and a gas supply unit <NUM>. The container <NUM> has a structure in which an upper cup <NUM> and a separator cup <NUM> are coupled together by a connector <NUM>. Further, the ultrasonic vibrator <NUM> includes an ultrasonic vibration plate <NUM> as its main component.

The upper cup <NUM> may have any shape as long as the upper cup <NUM> is a container having a space formed inside. In the ultrasonic atomization apparatus <NUM>, the upper cup <NUM> has a substantially cylindrical shape, and in the upper cup <NUM>, a space surrounded by a side surface being formed in a circular shape in plan view is formed. Meanwhile, in the separator cup <NUM>, a source solution <NUM> is accommodated.

The ultrasonic vibrator <NUM> applies ultrasonic waves to the source solution <NUM> in the separator cup <NUM> from the internal ultrasonic vibration plate <NUM>, and thereby atomizes the source solution <NUM>. Four ultrasonic vibrators <NUM> (only two of them are illustrated in <FIG>) are disposed in a bottom surface of a water tank <NUM>. Although only schematically illustrated in <FIG>, the upper side of the ultrasonic vibrator <NUM> is opened. Note that the number of ultrasonic vibrators <NUM> is not limited to four. One ultrasonic vibrator <NUM> or two or more ultrasonic vibrators <NUM> may be provided.

The internal hollow structure body <NUM> is a structure body including a hollow in side. In an upper surface part of the upper cup <NUM> of the container <NUM>, an opening part is formed, and as illustrated in <FIG>, the internal hollow structure body <NUM> is disposed in a manner of being inserted in to the upper cup <NUM> through the opening part. Here, in a state in which the internal hollow structure body <NUM> is inserted in the opening part, a part between the internal hollow structure body <NUM> and the upper cup <NUM> is hermetically closed. In other words, the part between the internal hollow structure body <NUM> and the opening part of the upper cup <NUM> is sealed.

For the shape of the internal hollow structure body <NUM>, any shape may be adopted as long as the shape is a shape in which a hollow is formed inside. In the configuration example of <FIG>, the internal hollow structure body <NUM> has a flask-like cross-sectional shape without a bottom surface. More specifically, the internal hollow structure body <NUM> illustrated in <FIG> includes a tubular part 3A, a circular truncated cone part 3B, and a cylindrical part 3C.

The tubular part 3A is a tubular path part having a cylindrical shape, and the tubular part 3A extends from the outside of the upper cup <NUM> to the inside of the upper cup <NUM> in a manner of being inserted through the opening part provided in the upper surface of the upper cup <NUM>. More specifically, the tubular part 3A is divided into an upper tubular part disposed on the outside of the upper cup <NUM> and a lower tubular part disposed on the inside of the upper cup <NUM>. Further, the upper tubular part is attached from the outside of the upper surface of the upper cup <NUM>, and the lower tubular part is attached from the inside of the upper surface of the upper cup <NUM>, and in a state in which these are attached together, the upper tubular part and the lower tubular part communicate to each other through the opening part disposed on the upper surface of the upper cup <NUM>. One end of the tubular part 3A is connected to, for example, the inside of a thin-film film forming apparatus that forms a thin film by using a source solution mist MT, which is present on the outside of the upper cup <NUM>. In contrast, another end of the tubular part 3A is connected to an upper end side of the circular truncated cone part 3B inside the upper cup <NUM>.

The circular truncated cone part 3B has its external appearance (side wall surface) of a circular truncated cone shape, and has a hollow being formed inside. The circular truncated cone part 3B has its upper surface and bottom surface being opened. In other words, the hollow being formed inside is closed, and there are no upper surface and bottom surface. The circular truncated cone part 3B is present in the upper cup <NUM>, and as described above, the upper end side of the circular truncated cone part 3B connects (communicates) to the another end of the tubular part 3A, and a lower end portion side of the circular truncated cone part 3B is connected to the upper end side of the cylindrical part 3C.

Here, the circular truncated cone part 3B has a cross-sectional shape that is widened toward the end, that is, from the upper end side toward the lower end side. In other words, the diameter of the side wall on the upper end side of the circular truncated cone part 3B is the smallest (the same as the diameter of the tubular part 3A), the diameter of the side wall on the lower end side of the circular truncated cone part 3B is the largest (the same as the diameter of the cylindrical part 3C), and the diameter of the side wall of the circular truncated cone part 3B is smoothly increased from the upper end side toward the lower end side.

The cylindrical part 3C is a part having a cylindrical shape, and as described above, the upper end side of the cylindrical part 3C connects (communicates) to the lower end side of the circular truncated cone part 3B, and the lower end side of the cylindrical part 3C faces the bottom surface of the upper cup <NUM>. Here, in the configuration example of <FIG>, the lower end side of the cylindrical part 3C is opened (specifically, does not have a bottom surface).

Here, in the configuration example of <FIG>, central axis in a direction extending from the tubular part 3A to the cylindrical part 3C through the circular truncated cone part 3B in the internal hollow structure body <NUM> substantially matches a central axis of the upper cup <NUM> of the cylindrical shape. Note that the internal hollow structure body <NUM> may be an integral structure, or may be, as illustrated in <FIG>, configured by combining each member of the upper tubular part constituting a part of the tubular part 3A, the lower tubular part constituting the other part of the tubular part 3A, the circular truncated cone part 3B, and the cylindrical part 3C. In the configuration example of <FIG>, a lower end portion of the upper tubular part is connected to an outer upper surface of the upper cup <NUM>, an upper end portion of the lower tubular part is connected to an inner upper surface of the upper cup <NUM>, and a member consisting of the circular truncated cone part 3B and the cylindrical part 3C is connected to a lower end portion of the lower tubular part, and the internal hollow structure body <NUM> consisting of a plurality of members is thereby configured.

When the internal hollow structure body <NUM> having the above-described shape is disposed in a manner of being inserted into the upper cup <NUM>, the inside of the upper cup <NUM> is divided into two spaces. The first space is a hollow part being formed inside the internal hollow structure body <NUM>. The hollow part is hereinafter referred to as an "atomization space <NUM>". The atomization space <NUM> is a space surrounded by the inner side surface of the internal hollow structure body <NUM>.

The space is a space formed by an inner surface of the upper cup <NUM> and an outer side surface of the internal hollow structure body <NUM>. The space is hereinafter referred to as a "gas supply space <NUM>". As described above, the inside of the upper cup <NUM> is sectioned into the atomization space <NUM> and the gas supply space <NUM>.

Further, the atomization space <NUM> and the gas supply space <NUM> are connected through a lower opening part of the cylindrical part 3C.

Further, in the configuration example of <FIG>, as can be seen from the shape of the internal hollow structure body <NUM> and the shape of the upper cup <NUM>, the gas supply space <NUM> is the widest on the upper side of the upper cup <NUM> and is gradually narrower toward the lower side of the upper cup <NUM>. In other words, a part of the gas supply space <NUM> that is surrounded by an outer side surface of the tubular part 3A and an inner side surface of the upper cup <NUM> is the widest, and a part of the gas supply space <NUM> that is surrounded by an outer side surface of the cylindrical part 3C and an inner side surface of the upper cup <NUM> is the narrowest.

The gas supply unit <NUM> is disposed in the upper surface of the upper cup <NUM>. Through the gas supply unit <NUM>, a carrier gas G4 for transferring the source solution mist MT (see <FIG>) being atomized by the ultrasonic vibrator <NUM> to the outside through the tubular part 3A of the internal hollow structure body <NUM> is supplied. As the carrier gas G4, for example, a high-concentration inert gas can be adopted. Further, as illustrated in <FIG>, the gas supply unit <NUM> is provided with a supply port 4a, and the carrier gas G4 is supplied into the gas supply space <NUM> of the container <NUM> through the supply port 4a present in the container <NUM>.

The carrier gas G4 supplied from the gas supply unit <NUM> is supplied into the gas supply space <NUM> and fills the gas supply space <NUM>, and is then introduced to the atomization space <NUM> through the lower opening part of the cylindrical part 3C.

In the ultrasonic atomization apparatus <NUM> of the first embodiment, the separator cup <NUM> of the container <NUM> has a cup-like shape, and accommodates the source solution <NUM> inside. A bottom surface BP1 of the separator cup <NUM> is inclined from a side surface part toward the center, and is formed into a spherical surface shape having a set curvature K1 other than "<NUM>".

In this manner, the bottom surface BP1 of the separator cup <NUM> is formed into a spherical surface shape with the center projecting downward, which is defined by the set curvature K1. One of the purposes for forming the bottom surface BP1 of the separator cup <NUM> into the spherical surface shape is an air bubble retention prevention purpose of preventing air bubbles of the source solution <NUM> from remaining near the bottom surface BP1 when the source solution mist MT is generated.

Further, the water tank <NUM> is filled with ultrasonic wave conveyance water <NUM>, which serves as an ultrasonic wave conveyance medium. The ultrasonic wave conveyance water <NUM> has a function of conveying ultrasonic vibration that is generated from the ultrasonic vibration plate <NUM> of the ultrasonic vibrator <NUM> disposed in the bottom surface of the water tank <NUM> to the source solution <NUM> in the separator cup <NUM>.

In other words, the ultrasonic wave conveyance water <NUM> is accommodated in the water tank <NUM> so as to be able to convey, to the inside of the separator cup <NUM>, vibration energy of ultrasonic waves (incident wave W1 thereof) applied from the ultrasonic vibrator <NUM>.

As described above, in the separator cup <NUM>, the source solution <NUM> to be atomized is accommodated, and a liquid level 15A of the source solution <NUM> is positioned lower than the position at which the connector <NUM> is disposed (see <FIG>).

Further, regarding the separator cup <NUM>, the positions of the separator cup <NUM> and the water tank <NUM> are set so that the entire bottom surface BP1 is immersed in the ultrasonic wave conveyance water <NUM>. Specifically, the bottom surface BP1 of the separator cup <NUM> is disposed above the bottom surface of the water tank <NUM> without touching the bottom surface of the water tank <NUM>, and the ultrasonic wave conveyance water <NUM> is present between the bottom surface BP1 of the separator cup <NUM> and the bottom surface of the water tank <NUM>.

In the ultrasonic atomization apparatus <NUM> having the configuration as described above, when application of ultrasonic vibration is caused from the ultrasonic vibration plate <NUM> of each of the four ultrasonic vibrators <NUM>, four incident waves W1 generated by the ultrasonic waves transmit through the ultrasonic wave conveyance water <NUM> and the bottom surface BP1 of the separator cup <NUM> and enter the source solution <NUM> in the separator cup <NUM> as transmission waves W11.

Then, liquid columns <NUM> are raised from the liquid level 15A, and the source solution <NUM> transition to liquid particles and to mist, producing the source solution mist MT in the atomization space <NUM>. The source solution mist MT generated in the gas supply space <NUM> is supplied to the outside through an upper opening part of the tubular part 3A by the carrier gas G4 supplied from the gas supply unit <NUM>.

In the ultrasonic atomization apparatus <NUM> of the first embodiment, when a part of the four incident waves (at least one incident wave; a plurality of incident waves) transmitted from the four ultrasonic vibrators <NUM> (at least one ultrasonic vibrator) is reflected on the bottom surface of the bottom surface BP1 of the separator cup <NUM>, four reflected waves W2 (at least one bottom surface-reflected wave) are obtained.

The separator cup <NUM> and the four ultrasonic vibrators <NUM> of the ultrasonic atomization apparatus <NUM> are provided so as to satisfy the following reflected wave avoidance condition.

The reflected wave avoidance condition is a condition that "the four reflected waves W2 are not received by any of the four ultrasonic vibrators <NUM>". Note that, here, "not received" means that the four ultrasonic vibrators <NUM> are not disposed in a propagation path of the four reflected waves W2. In the following, the reflected wave avoidance condition will be described in detail.

<FIG> is an explanatory diagram schematically illustrating a configuration of a conventional ultrasonic atomization apparatus <NUM>. In <FIG>, parts similar to those of the ultrasonic atomization apparatus <NUM> of the first embodiment are denoted by the same reference signs and general description thereof will be omitted.

A container <NUM> corresponding to the container <NUM> of the ultrasonic atomization apparatus <NUM> includes a structure of a combination of an upper cup <NUM> and a separator cup <NUM>.

Further, in the ultrasonic atomization apparatus <NUM>, a bottom surface BP6 of the separator cup <NUM> of the container <NUM> is gently inclined from the side surface part toward the center, and is formed into a spherical surface shape defined by a set curvature K6 (< K1). The set curvature K6 is set to a relatively small value to the extent of allowing the air bubble retention prevention purpose to be achieved.

In the conventional ultrasonic atomization apparatus <NUM>, when a part of the four incident waves transmitted from the four ultrasonic vibrators <NUM> is reflected on the bottom surface of the bottom surface BP6 of the separator cup <NUM>, the four reflected waves W2 are obtained.

In the conventional ultrasonic atomization apparatus <NUM>, the set curvature K6 of the bottom surface BP6 of the separator cup <NUM> is considerably smaller than the set curvature K1, and the four ultrasonic vibrators <NUM> are closely disposed so as to be relatively close to the center of the bottom surface of the water tank <NUM>. The reason why the four ultrasonic vibrators <NUM> are closely disposed as described above is to cause the four incident waves W1 to securely reach the source solution <NUM> in the separator cup <NUM>.

Thus, the separator cup <NUM> and the four ultrasonic vibrators <NUM> of the ultrasonic atomization apparatus <NUM> fail to satisfy the reflected wave avoidance condition unlike the first embodiment. Specifically, the four reflected waves W2 are securely received by the four ultrasonic vibrators <NUM>. This is because the angle of reflection of the reflected waves W2 (angle of incidence of the incident waves W1) is inevitably small due to the shape of the bottom surface BP6 of the separator cup <NUM> and the disposition state of the four ultrasonic vibrators <NUM>.

In the following, the reflected wave avoidance condition will be considered. Note that each of the incident waves W1 and the reflected waves W2 to W4 illustrated in <FIG> and <FIG> described above and the figures to be described later is schematically illustrated. In actuality, the area of the ultrasonic vibration plate <NUM> to be described later in detail corresponds to an ultrasonic wave output size. In the figures, however, the ultrasonic wave output from the center point of the ultrasonic vibration plate <NUM> is schematically illustrated with arrows. Further, each of the incident waves W1 and the reflected waves W2 to W4 of the ultrasonic waves has rectilinear propagation property, and is beam-like.

<FIG> are each an explanatory diagram illustrating details of a surrounding structure of one ultrasonic vibrator <NUM>. As illustrated in the figures, the ultrasonic vibrator <NUM> is provided in a state of being embedded into the bottom surface of the water tank <NUM>. An open region OP2 is provided above the ultrasonic vibrator <NUM>. In this case, setting is made to a liquid level height H15 from the ultrasonic vibration plate <NUM> to the liquid level 15A of the source solution <NUM>.

When the ultrasonic vibration plate <NUM> inside the ultrasonic vibrator <NUM> is vibrated, the ultrasonic waves are applied. Thus, to be precise, the liquid level height H15 is height from the center of the ultrasonic vibration plate <NUM> to the liquid level 15A. Note that a cooling pipe <NUM> allows cooling water to flow inside in order to cool the ultrasonic wave conveyance water <NUM>.

The ultrasonic vibration plate <NUM> of the ultrasonic vibrator <NUM> has a disk-like shape having an outer diameter of approximately <NUM>, and ultrasonic waves of the same size as the disk-like ultrasonic vibration plate <NUM> are generated due to vibration of the ultrasonic vibration plate <NUM>. The ultrasonic waves have high directivity, and travel without spreading within a near field length DL and spread at a certain angle beyond the near field length DL. Note that the near field length DL can be calculated according to the following equation (<NUM>).

Note that, in equation (<NUM>), "ED" represents the outer diameter of the ultrasonic vibration plate <NUM>, and "λ" represents speed of sound (<NUM>/sec in water).

It is experientially known that, based on factors such as the near field length DL described above, the atomization amount of the source solution mist MT can be brought to the maximum level when the liquid level height H15 is set to <NUM> to <NUM>. Thus, the distance between the bottom surface BP1 (BP6) of the separator cup <NUM> (<NUM>) and the ultrasonic vibration plate <NUM> of the ultrasonic vibrator <NUM> is inevitably reduced.

<FIG> is an explanatory diagram schematically illustrating a curvature radius r6 of the bottom surface BP6 of the conventional separator cup <NUM>. As illustrated in the figure, the cross-sectional shape of the bottom surface BP6 is formed into an arc shape having a relatively long curvature radius r6 with respect to an imaginary center point C6, and the set curvature K6 (= <NUM>/r6) is sufficiently small.

Further, setting is made to the same distance D6 from a center point C10 (reference point) of the bottom surface of the water tank <NUM> to a center position of the ultrasonic vibration plate <NUM> of each of the four ultrasonic vibrators <NUM>. The distance D6 is relatively short.

Thus, it is substantially impossible that the conventional ultrasonic atomization apparatus <NUM> satisfies the reflected wave avoidance condition. This is because the reflected wave avoidance condition is not taken into consideration, and the set curvature K6 of the bottom surface BP6 of the separator cup <NUM> in consideration of the air bubble retention prevention purpose need not be set large. In addition, when the set curvature K6 is set large, there is a negative element that the amount of the source solution <NUM> accommodated in the separator cup <NUM> is reduced due to the restriction of the liquid level height H15, and thus it is desirable that the set curvature K6 be set small within the range of satisfying the air bubble retention prevention purpose.

Thus, as illustrated in <FIG> and <FIG>, in the bottom surface BP6 of the conventional separator cup <NUM> in which the set curvature K6 is set to be relatively small, the reflected waves W2 are invariably received in a partial region RS of the ultrasonic vibrator <NUM>.

<FIG> is an explanatory diagram illustrating a curvature radius r1 of the bottom surface BP1 of the separator cup <NUM> and a disposition state of the ultrasonic vibrators <NUM>.

As illustrated in the figure, the cross-sectional shape of the bottom surface BP1 is formed into an arc shape having a relatively short curvature radius r1 with respect to an imaginary center point C1, and the set curvature K1 (= <NUM>/r1) is sufficiently large as compared to the set curvature K6.

However, in a state in which the distance D6 from the center position of the ultrasonic vibration plate <NUM> of each of the ultrasonic vibrators <NUM> is relatively short, the four ultrasonic vibrators <NUM> (ultrasonic vibration plates <NUM>) are disposed at positions relatively close to the center part of the bottom surface BP1 in plan view.

In the above-described disposition state of the four ultrasonic vibrators <NUM>, the angle of reflection of the reflected waves W2 (angle of incidence of the incident waves W1) cannot be increased, which may still hinder satisfaction of the reflected wave avoidance condition. Specifically, as illustrated in <FIG>, the reflected waves W2 obtained when the incident waves W1 of each ultrasonic vibrator <NUM> (ultrasonic vibration plate <NUM>) are reflected on the bottom surface BP1 may be received in the ultrasonic vibrators <NUM>.

Note that, in the disposition state of the four ultrasonic vibrators <NUM> illustrated in <FIG> as well, the reflected wave avoidance condition can be satisfied by setting to a curvature radius rx that is even shorter than the curvature radius r1 illustrated in <FIG> and setting the set curvature Kx defining the spherical surface of the bottom surface BP1 to be larger than the set curvature K1.

<FIG> is an explanatory diagram illustrating the curvature radius r1 of the bottom surface BP1 of the separator cup <NUM> of the first embodiment and the disposition state of the ultrasonic vibrators <NUM>. <FIG> is a plan view illustrating a disposition state of the four ultrasonic vibrators <NUM> in the bottom surface of the water tank <NUM>. In <FIG>, the planar shape of the bottom surface of the water tank <NUM> exhibits a circular configuration. Note that the hatched region denotes the side surface of the water tank <NUM>.

As illustrated in <FIG>, the cross-sectional shape of the bottom surface BP1 is formed into an arc shape having a relatively short curvature radius r1 with respect to the imaginary center point C1, and the set curvature K1 is sufficiently large as compared to the set curvature K6.

Further, as illustrated in <FIG>, in the bottom surface of the water tank <NUM>, the four ultrasonic vibrators <NUM> are disposed such that the four ultrasonic vibration plates <NUM> are located to be annularly spaced apart at regular intervals (intervals of <NUM> degrees) along outer circumference of a distance D1 (> D6) about the center point C10 being a reference point.

In this manner, the four ultrasonic vibrators <NUM> (ultrasonic vibration plates <NUM>) are disposed to be separated apart from each other so as to have the same distance D1 from the center point C10 being a reference point of the bottom surface of the water tank <NUM>.

Further, the distance D1 from the center point C10 of the bottom surface of the water tank <NUM> is set to be longer than the conventional distance D6. As a result, each of the four ultrasonic vibration plates <NUM> is made far from the center point C10, and the intervals of the four ultrasonic vibrators <NUM> are also sufficiently large.

<FIG> is a cross-sectional diagram of the ultrasonic vibrator <NUM> illustrating the A-A cross-section of <FIG>. As illustrated in the figure, the ultrasonic vibration plate <NUM> in the ultrasonic vibrator <NUM> is fixed to be slightly inclined due to a support rubber <NUM> that is provided on an upper portion of a base <NUM>. Specifically, the inclination is approximately <NUM> degrees with respect to the bottom surface of the water tank <NUM>.

Specifically, the ultrasonic vibration plate <NUM> of each ultrasonic vibrator <NUM> is slightly inclined toward a direction away from the center point C10. In this manner, the four ultrasonic vibration plates <NUM> have a predetermined angle, other than "<NUM>", with respect to the bottom surface of the water tank <NUM>.

As described above, the first embodiment provides technical improvement that the set curvature K1 of the bottom surface BP1 of the separator cup <NUM> is set larger than the conventional set curvature K6, and the distance D1 from the center point C10 of the bottom surface of the water tank <NUM> of each of the four ultrasonic vibrators <NUM> (ultrasonic vibration plates <NUM>) is set longer than the conventional distance D6.

Thus, by providing the technical improvement, the set curvature K1 of the bottom surface BP1 and the distance D1 from the center point C10 of the four ultrasonic vibration plates <NUM> can be set so that the reflected wave avoidance condition is satisfied.

As a result, as illustrated in <FIG>, the angle of reflection of the reflected waves W2 (angle of incidence of the incident waves W1) can be made larger than the conventional technology, with the result that the effect that the reflected waves W2 are not received in the ultrasonic vibrators <NUM> can be achieved.

Note that, for the convenience of description, although <FIG> illustrates the incident wave W1 and the reflected wave W2 related to one ultrasonic vibrator <NUM>, the reflected waves W2 are not received in the other three ultrasonic vibrators <NUM> as well. The reason therefor is as follows.

Each of the four ultrasonic vibrators <NUM> is disposed at the same distance D1 from the center point C10, and the inclination of the four ultrasonic vibration plates <NUM> is also inclined at approximately <NUM> degrees toward a direction away from the center point C10 in common. Thus, regarding the four incident waves W1 transmitted from the four ultrasonic vibration plates <NUM>, the angle of incidence of the incident waves W1 (angle of reflection of the reflected waves W2) with respect to the bottom surface BP1 of the separator cup <NUM> is the same. Thus, the four reflected waves W2 are not received in the four ultrasonic vibrators <NUM> (ultrasonic vibration plates <NUM>).

In this manner, in the ultrasonic atomization apparatus <NUM> of the first embodiment, the separator cup <NUM> and the four ultrasonic vibrators <NUM> are set so as to satisfy the reflected wave avoidance condition. Specifically, the bottom surface BP1 of the separator cup <NUM> is set to the set curvature K1 (> K6), and is set to the distance D1 (> D6) from the center point C10 of the bottom surface of the water tank <NUM> of each of the four ultrasonic vibrators <NUM>.

Thus, in the ultrasonic atomization apparatus <NUM>, negative influence such as failure caused by the fact that the four ultrasonic vibrators <NUM> receive the four reflected waves W2 (at least one bottom surface-reflected wave) does not occur. Consequently, durability of the ultrasonic atomization apparatus <NUM> can be enhanced.

Further, the bottom surface BP1 of the separator cup <NUM> is formed into a spherical surface shape with the center projecting downward. Thus, when the set curvature K1 defining the spherical surface is set to be sufficiently larger than the conventional set curvature K6 and the angle of reflection of the four reflected waves W2 (angle of incidence of the four incident waves W1) is set large, the reflected wave avoidance condition can be satisfied.

In addition, each of the four ultrasonic vibrators <NUM> is disposed to be separated apart from each other so as to have the same distance D1 from the center point C <NUM> of the bottom surface of the water tank <NUM> with respect to the separator cup <NUM> having the bottom surface BP1 in which the spherical surface is defined by the set curvature K1.

Thus, when the distance D1 is made sufficiently longer than the conventional distance D6, the reflected wave avoidance condition can be satisfied.

<FIG> is an explanatory diagram schematically illustrating a configuration of an ultrasonic atomization apparatus <NUM> being a second embodiment of the present invention. In <FIG>, constituent parts similar to those of the ultrasonic atomization apparatus <NUM> of the first embodiment are denoted by the same reference signs and description thereof is omitted as appropriate, and features of the second embodiment will be mainly described.

As illustrated in the figure, four ultrasonic wave absorption members <NUM> (only two of them are illustrated in <FIG>) are provided on a surface of the bottom surface of a water tank 10B, so as to correspond to the four reflected waves W2. The four ultrasonic wave absorption members <NUM> are embedded in a part of the bottom surface of the water tank 10B so as to form a surface region of the water tank 10B. The difference between the water tank 10B of the second embodiment and the water tank <NUM> of the first embodiment lies in presence or absence of the four ultrasonic wave absorption members <NUM>.

The four ultrasonic wave absorption members <NUM> are provided in four reflected wave reception regions that receive the four reflected waves W2 in the bottom surface of the water tank 10B. Similarly to the bottom surface of the water tank <NUM> illustrated in <FIG>, the bottom surface of the water tank 10B has predetermined thickness. Thus, in the bottom surface of the water tank 10B, a recess portion is provided in an upper portion of each of the four reflected wave reception regions, and the ultrasonic wave absorption member <NUM> is embedded in each recess portion.

Note that possible examples of a constituent material of the ultrasonic wave absorption member <NUM> include various rubber materials including urethane rubber, silicone rubber, fluorocarbon rubber, ethylene propylene rubber, butyl rubber, and ethylene rubber.

In this manner, the ultrasonic atomization apparatus <NUM> of the second embodiment has features in that the four ultrasonic wave absorption members <NUM> (a plurality of ultrasonic wave absorption members) are provided in the four reflected wave reception regions (a plurality of reflected wave reception regions) in the bottom surface of the water tank 10B.

The four reflected wave reception regions can be recognized in advance from the disposition of the four ultrasonic vibrators <NUM> (ultrasonic vibration plates <NUM>), the inclination of the ultrasonic vibration plates <NUM>, the set curvature K1 defining the spherical surface of the bottom surface BP1 of the separator cup <NUM>, and the like.

As described above, owing to the four ultrasonic wave absorption members <NUM> (a plurality of ultrasonic wave absorption members) provided in the bottom surface of the water tank 10B, the ultrasonic atomization apparatus <NUM> of the second embodiment can securely avoid a phenomenon in which the four reflected waves W2 (a plurality of bottom surface-reflected waves) enter the bottom surface of the water tank 10B other than the four ultrasonic wave absorption members <NUM>, and can protect the bottom surface of the water tank 10B.

As a result, the ultrasonic atomization apparatus <NUM> of the second embodiment can have higher durability than that of the first embodiment.

<FIG> is an explanatory diagram schematically illustrating a configuration (including a modification thereof) of an ultrasonic atomization apparatus <NUM> being a third embodiment of the present invention. In <FIG>, constituent parts similar to those of the ultrasonic atomization apparatus <NUM> of the first embodiment are denoted by the same reference signs and description thereof is omitted as appropriate, and features of the third embodiment will be mainly described. Note that <FIG> also illustrates ultrasonic wave absorption members <NUM> as a modification to be described later.

As illustrated in the figure, four ultrasonic wave reflection members <NUM> (only two of them are illustrated in <FIG>) are provided on a surface of the bottom surface of the water tank 10C, so as to correspond to the four reflected waves W2. The four ultrasonic wave reflection members <NUM> are embedded in a part of the bottom surface of the water tank 10C so as to form a surface region of the water tank 10C. Regarding the basic configuration of the third embodiment, the difference between the water tank 10C of the third embodiment and the water tank <NUM> of the first embodiment lies in presence or absence of the four ultrasonic wave reflection members <NUM>.

The four ultrasonic wave reflection members <NUM> are provided in the four reflected wave reception regions that receive the four reflected waves W2 in the bottom surface of the water tank 10C. In the bottom surface of the water tank 10C, a recess portion is provided in an upper portion of each of the four reflected wave reception regions, and the ultrasonic wave reflection member <NUM> is embedded in each recess portion.

In this manner, the basic configuration of the ultrasonic atomization apparatus <NUM> of the third embodiment has features in that the four ultrasonic wave reflection members <NUM> (a plurality of ultrasonic wave reflection members) are provided in the four reflected wave reception regions (a plurality of reflected wave reception regions) in the bottom surface of the water tank 10C.

Note that possible examples of a constituent material of the ultrasonic wave reflection member <NUM> include stainless steel, copper, and the like.

In this manner, owing to the four ultrasonic wave reflection members <NUM> (a plurality of ultrasonic wave reflection members) provided in the bottom surface of the water tank 10C, the basic configuration of the ultrasonic atomization apparatus <NUM> of the third embodiment can securely avoid a phenomenon in which the four reflected waves W2 (a plurality of bottom surface-reflected waves) enter the bottom surface of the water tank 10C other than the four ultrasonic wave reflection members <NUM>, and can protect the bottom surface of the water tank 10C.

As a result, the basic configuration of the ultrasonic atomization apparatus <NUM> of the third embodiment can have durability higher than that of the first embodiment.

Note that, when the four reflected waves W2 are reflected on the four ultrasonic wave reflection members <NUM>, four secondary reflected waves W3 (a plurality of secondary reflected waves) are obtained.

Surfaces of the four ultrasonic wave reflection members <NUM> of the third embodiment have a predetermined angle, other than "<NUM>", with respect to the bottom surface of the water tank 10C, and are specifically inclined to a direction of the center point C10 of the bottom surface of the water tank <NUM>.

Further, the predetermined angle of the surfaces of the ultrasonic wave reflection members <NUM> is set such that the four secondary reflected waves W3 enter the source solution <NUM> as secondary transmission waves W31 through the bottom surface BP1 of the separator cup <NUM>.

In this manner, the basic configuration of the four ultrasonic wave reflection members <NUM> of the third embodiment has the predetermined angle, other than "<NUM>", with respect to the bottom surface of the water tank 10C, and can thus securely cause a part of the four secondary reflected waves W to enter the source solution <NUM> as the secondary transmission waves W31 by adjusting the predetermined angle.

As a result, the ultrasonic atomization apparatus <NUM> of the third embodiment allows the four secondary transmission waves W31 generated by the four secondary reflected waves W3 to enter the source solution <NUM> in addition to the four transmission waves W11 generated by the four incident waves W1, and thus exerts an atomization amount increase effect that the atomization amount of the source solution mist MT to be generated can be increased accordingly.

Further, in the ultrasonic atomization apparatus <NUM> of the third embodiment, when a part of the four secondary reflected waves W3 is reflected on the bottom surface of the bottom surface BP1 of the separator cup <NUM>, four tertiary reflected waves W4 are obtained.

Thus, four ultrasonic wave absorption members <NUM> (only two of them are illustrated in <FIG>) are provided on a surface of the bottom surface of the water tank 10C, so as to correspond to the four tertiary reflected waves W4. The four ultrasonic wave absorption members <NUM> are embedded in a part of the bottom surface of the water tank 10C so as to form a surface region of the water tank 10C. The difference between the water tank 10C of the modification of the third embodiment and the water tank <NUM> of the first embodiment lies in presence or absence of the four ultrasonic wave reflection members <NUM> and the four ultrasonic wave absorption members <NUM>. Note that possible examples of a constituent material of the ultrasonic wave absorption member <NUM> include constituent materials similar to those of the ultrasonic wave absorption member <NUM> of the second embodiment.

The four ultrasonic wave absorption members <NUM> are provided in four tertiary reflected wave reception regions that receive the four tertiary reflected waves W4 in the bottom surface of the water tank 10C. In the bottom surface of the water tank 10C, a recess portion is provided in an upper portion of each of the four tertiary reflected wave reception regions, and the ultrasonic wave absorption member <NUM> is embedded in each recess portion.

In this manner, the modification of the ultrasonic atomization apparatus <NUM> of the third embodiment has features in that the four ultrasonic wave absorption members <NUM> (a plurality of ultrasonic wave reflection members) are further provided in the four tertiary reflected wave reception regions (a plurality of tertiary reflected wave reception regions) in the bottom surface of the water tank 10C.

Owing to the four ultrasonic wave absorption members <NUM> (a plurality of ultrasonic wave reflection members) provided in the bottom surface of the water tank 10C, the modification of the third embodiment described above can securely avoid a phenomenon in which the four tertiary reflected waves W4 (a plurality of tertiary reflected waves) enter the bottom surface of the water tank 10C other than the four ultrasonic wave absorption members <NUM>, and can protect the bottom surface of the water tank 10C.

As a result, the modification of the ultrasonic atomization apparatus <NUM> of the third embodiment can have durability higher than that of the basic configuration of the third embodiment.

As the constituent material of the separator cup <NUM> of each of the first embodiment to the third embodiment, polypropylene (PP), which easily transmits ultrasonic waves, is generally adopted. However, fluorocarbon resin as typified by PTFE may be adopted. Specifically, the separator cup <NUM> may have the bottom surface BP1 whose constituent material is fluorocarbon resin.

The fluorocarbon resin has a property of having relatively high tolerance against various solvents (solvent of the source solution <NUM>). Accordingly, the separator cup <NUM> of the ultrasonic atomization apparatus(es) <NUM> (to <NUM>) can exert relatively high tolerance against the source solution <NUM>.

In contrast, the fluorocarbon resin is inferior to PP in transmissiveness of ultrasonic waves. Thus, in each of the ultrasonic atomization apparatuses <NUM> to <NUM>, in order to obtain ultrasonic wave characteristics at practical level, it is conceivable to set the thickness of the bottom surface BP1 to <NUM> or less, desirably <NUM> or less.

Further, the ultrasonic atomization apparatus <NUM> of the third embodiment having the four ultrasonic wave reflection members <NUM> has the atomization amount increase effect, and can accordingly improve the inferiority of the fluorocarbon resin in transmissiveness of ultrasonic waves.

Claim 1:
An ultrasonic atomization apparatus comprising:
a container (<NUM>) including a separator cup (<NUM>) configured to accommodate a source solution (<NUM>) at a lower part;
an internal hollow structure body (<NUM>) including a hollow inside being provided above said separator cup in said container;
a water tank (10B) that accommodates an ultrasonic wave conveyance medium (<NUM>) inside, said water tank and said separator cup being positioned so that a bottom surface (BP1) of said separator cup is immersed in said ultrasonic wave conveyance medium; and
a plurality of ultrasonic vibrators (<NUM>) provided in a bottom surface of said water tank, wherein
when parts of a plurality of incident waves transmitted from said plurality of ultrasonic vibrators are reflected on said bottom surface of said separator cup, a plurality of bottom surface-reflected waves (W2) is obtained,
said separator cup and said plurality of ultrasonic vibrators are provided to satisfy a reflected wave avoidance condition,
said reflected wave avoidance condition is a condition that "said plurality of ultrasonic vibrators are not disposed in a propagation path of said plurality of the bottom surface-reflected waves",
said bottom surface of said separator cup is formed into a spherical surface shape with a center projecting downward,
said plurality of ultrasonic vibrators are disposed to be separated apart from each other so as to have a same distance (D1) from a reference point (C10) of said bottom surface of said water tank,
said bottom surface of said water tank includes a plurality of reflected wave reception regions configured to receive said plurality of bottom surface-reflected waves, and
said plurality of reflected wave reception regions are different from the regions where said plurality of ultrasonic vibrators are provided,
characterized in that
said ultrasonic atomization apparatus further comprises a plurality of ultrasonic wave absorption members (<NUM>) provided in said plurality of reflected wave reception regions, a constituent material of said plurality of ultrasonic wave absorption members including at least one of urethane rubber, silicone rubber, fluorocarbon rubber, ethylene propylene rubber, butyl rubber, and ethylene rubber.