JP3967855B2 - Object levitation device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an object levitating apparatus that levitates an object using a radiation pressure such as a sound wave.
[0002]
[Prior art]
As an object levitating apparatus for levitating an object in the air, an object levitating apparatus for levitating an object on the surface of the vibrating body by the radiation pressure of the sound wave of the vibrating body vibrated by the vibrating means is disclosed in Japanese Patent Laid-Open Nos. 7-24415 and 7 -137824. In this apparatus, a flat vibrating body is used, the surface of the object to be levitated facing the surface of the flat vibrating body is a flat surface, and the object is levitated by the radiation pressure of sound waves generated by the vibration of the vibrating body. In addition, each of the above publications discloses that in a state where an object is levitated by an object levitating device, compressed air is jetted toward the levitated object or ultrasonic waves are emitted to cause the levitated object to travel. Further, as a method of moving a floating object, a vibrating body is formed long, and a vibrating means is provided at one end of the vibrating body to cause the vibrating body to bend and vibrate, and an energy conversion means is connected to the other end of the vibrating body. Thus, a method of running an object in a levitating state using a wave of flexural vibration as a traveling wave is disclosed.
[0003]
However, in the object levitation device, it is difficult to hold the object in a predetermined position when the surface of the vibrating body is inclined from the horizontal, and when a lateral force acts on the object, the levitation object can be easily moved horizontally. There is a problem of moving and falling off the position facing the vibrating body. In addition, when a levitation object is caused to travel, it is difficult to cause the propulsive force acting on the levitation object to act in the traveling direction with high accuracy. Therefore, a guide or a regulating member that regulates the movement in the horizontal direction is required.
[0004]
In JP-A-7-137824, as means for solving the above problem, as shown in FIG. 7, a pair of flat plate-like vibrating bodies 51 are arranged in a substantially V shape, and each vibrating body 51 is connected to a horn 52. An object levitating apparatus is disclosed in which the vibrator 53 is coupled to the vibrator 53 and electrically connected to an oscillator (not shown). The horn 52 is formed with a flange portion 52a, and the flange portion 52a is fastened to the case 54 containing the vibrator 53 and the horn 52 via a packing 52b. In this object levitation apparatus, the object 55 has a bottom surface (side surface) that forms an angle equal to the angle formed by both vibrating bodies 51, and is floated in a state of receiving an equal radiation pressure from the vibrating body 51 on both bottom surfaces.
[0005]
Japanese Patent Application Laid-Open No. 9-202425 discloses a configuration in which a vibrating body having a narrower width than an object is arranged in parallel in a horizontal state, and the object is levitated and conveyed by the sound pressure of the vibrating body, as an object conveying device provided with an object levitation device Is disclosed. If a notch with a rectangular cross-section is formed on the outer lower surface of the vibrating bodies arranged in parallel over almost the entire length, the radiant pressure of the sound wave emitted by the vibrating body is smaller than the center on both edges in the width direction of the object conveying path. It is disclosed that it becomes large.
[0006]
[Problems to be solved by the invention]
As an advantage of the method of levitation and transportation of objects using the radiation pressure of sound waves, compared to the method of levitation and transportation of objects using compressed air such as compressed air, the so-called clean room atmosphere is cleaned. When used under conditions to be maintained, it may be easy to reduce the size of the apparatus, such as eliminating the need for means for preventing the diffusion of air injected from the pressurized gas supply means.
[0007]
As in the object conveying device disclosed in Japanese Patent Laid-Open No. 9-202425, the method of increasing the radiation pressure of sound waves on both sides in the width direction of the object conveying path by changing the thickness of the vibrating body in the width direction Is not sufficient to keep it from moving out of position. In addition, there is a problem that it takes time to process the vibrating body.
[0008]
In the configuration shown in FIG. 7, the levitated object is stably levitated in a state where it receives uniform radiation pressure from both vibrating bodies 51. However, it is necessary for the floating object to have a bottom surface having the same angle as the angle formed by both vibrating bodies 51, and it has been difficult to apply to an object having a flat bottom surface such as a flat plate. There are liquid crystal substrates (glass substrates) and silicon wafers as objects to be conveyed in a clean room, but these objects are all thin plates. In order to float an object having a flat bottom surface, it is necessary to place the object on a case or board having a V-shaped bottom surface, which is troublesome and difficult to place stably.
[0009]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an object levitation apparatus capable of levitating and holding an object having a flat bottom surface such as a flat plate in a stable state.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, an object having a flat bottom surface is formed on the surface of the vibrating body by exciting the flat vibrating body with the excitation means and emitting the sound pressure of the vibrating body. An object levitation device for levitation, the surface of which is inclined inward in the opposite direction with respect to the bottom surface of the object, and is arranged so that the radiation pressure acting on the object is balanced , The inclination angle was formed such that the angle formed between the horizontal plane and the surface of the vibrating body was 3 ° or less with respect to the horizontal plane .
[0011]
According to a second aspect of the present invention, in the first aspect of the present invention, the pair of vibrators are arranged such that the edges on the side away from each other extend along the edges in the vicinity of the opposing edges of the object. Has been.
[0012]
According to a third aspect of the present invention, in the first or second aspect of the present invention, the excitation means includes a horn having the vibrating body attached to the tip thereof so as to be able to vibrate integrally. The horn and the vibrator are disposed in a state inclined at the same angle as the angle formed by the horizontal plane and the vibrating body with respect to the vertical direction.
[0013]
According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the excitation means includes a horn having the vibrating body attached to the tip thereof so as to be able to vibrate integrally. In a state where the child is arranged so as to extend in the vertical direction, the child is formed so as to be inclined at the same angle as the angle formed by the horizontal plane and the vibrating body with respect to the horizontal plane, and the horn and the vibrator are arranged so as to extend in the vertical direction.
[0014]
Therefore, in the first aspect of the present invention, an object having a flat bottom surface is levitated on the surface of the vibrating body by the radiation pressure of the sound wave from the flat vibrating body excited by the excitation means. Radiation pressure acts obliquely on the object from at least one set of vibrating bodies, and the object floats stably in a state where the horizontal component forces facing each other are balanced. When radiation pressure acts in a direction perpendicular to the bottom surface of the object, when a horizontal force is applied to the object, the object easily moves horizontally due to the force and falls off the position facing the vibrating body. However, when the vibrating body is placed in an inclined state with respect to the bottom surface of the object, an inward air flow is generated between the floating object and the vibrating body, and there is a horizontal force facing each other due to the air flow. Thus, the object remains in a stable state at a predetermined position as long as a small horizontal force is applied to the object.
[0015]
In the second aspect of the invention, in the first aspect of the invention, the object is less likely to move outward from the position where the edge faces the edge of the vibrating body in the levitated state. When the object is disposed in the vicinity of the edge along the edge of the pair of vibrators away from each other, the object is stably held at a position corresponding to the edge of the vibrator.
[0016]
According to a third aspect of the present invention, in the first or second aspect of the present invention, the excitation means includes a horn having the vibrating body attached to the tip thereof so as to be able to vibrate integrally. Are arranged so as to be inclined at a predetermined angle with respect to the horizontal axis, and the vibrating body is inclined at a predetermined angle with respect to the horizontal plane.
[0017]
According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the excitation means includes a horn having the vibrating body attached to the tip thereof so as to be able to vibrate integrally. Since the child is arranged so as to extend in the vertical direction, it is formed so as to be inclined at the same angle as the angle formed by the horizontal plane and the vibrating body with respect to the horizontal plane. It arrange | positions so that it may become a predetermined | prescribed inclination | tilt angle with respect to an object.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
A first embodiment in which the present invention is embodied in an object levitating apparatus for levitating and holding a flat plate will be described below with reference to FIGS.
[0019]
As shown in FIGS. 1A and 1B, the object levitation apparatus 1 includes a pair (one pair) of vibrators 2a and 2b formed in a rectangular plate shape. Each of the vibrating bodies 2a and 2b has a width that is less than 1/2 (approximately 1/3 in this embodiment) of the width W of the rectangular plate-like object 3 (the length in the left-right direction in FIG. 1A). 3 is formed to be approximately the same length as 3. The vibrating bodies 2 a and 2 b are arranged such that the edges 4 a and 4 b on the side away from each other extend along the edges 3 a and 3 b in the vicinity of the facing edges 3 a and 3 b of the object 3. Each vibrating body 2a, 2b is disposed so as to incline downward from the edge 4a, 4b side toward the opposite edge.
[0020]
The vibrating bodies 2a and 2b are fastened to the tip of the horn 5 constituting the excitation means by screws (not shown). The horn 5 is formed in a flat rectangular parallelepiped shape having the same length as the widths of the vibrating bodies 2a and 2b, and is attached in a state perpendicular to the longitudinal direction at the center in the longitudinal direction of the vibrating bodies 2a and 2b.
[0021]
The horn 5 is fixed to the vibrator 6 on the surface opposite to the surface to which the vibrating bodies 2a and 2b are fastened. A so-called Langevin-type vibrator is used as the vibrator 6 and includes a pair of ring-shaped piezoelectric elements 7a and 7b, a ring-shaped electrode plate 7c disposed between the piezoelectric elements 7a and 7b, and piezoelectric elements 7a and 7b. The metal blocks 8a and 8b arranged at positions where they come into contact with the outer surface are fastened and fixed by bolts (not shown). The bolt is screwed into a screw hole (not shown) formed in the metal block 8a from the metal block 8b side. Both metal blocks 8a and 8b are in a state of being electrically connected to each other via bolts.
[0022]
The electrode plate 7c is connected to the oscillator 10 via the wiring 9a, and the ground terminal of the oscillator 10 is connected to the metal block 8b via the wiring 9b. The oscillator 10 is driven by a control signal from a control device (not shown). The horn 5, the vibrator 6, and the oscillator 10 constitute excitation means for exciting the vibrating bodies 2 a and 2 b.
[0023]
The front end surface 5a of the horn 5 is formed on a plane perpendicular to the axial direction of the vibrator 6, and the central axis of the horn 5 and the vibrator 6 with respect to the vertical direction is a predetermined angle θ between the horizontal plane and the vibrating bodies 2a and 2b. It is arranged in a state inclined at the same angle. The predetermined angle θ is an angle at which a radiation pressure is generated that acts to balance the horizontal component forces facing each other with respect to the object 3, and the appropriate value varies depending on the mass of the object 3, the areas of the vibrating bodies 2a and 2b, and the like. However, it is, for example, approximately 1 °, and usually 3 ° or less.
[0024]
Next, the operation of the apparatus configured as described above will be described.
The object levitation apparatus 1 is mounted on, for example, a transport vehicle, and is transported to a target position by moving the transport vehicle while holding the object 3 to be transported in a floating state.
[0025]
The object 3 is placed on both vibrators 2a and 2b so that both edges 3a and 3b in the width direction thereof are aligned with the edges 4a and 4b of both vibrators 2a and 2b. In this state, the oscillator 10 is driven at a predetermined resonance frequency (for example, around 20 kHz) by driving the oscillator 10, the horn 5 is longitudinally vibrated, and the vibrators 2 a and 2 b are excited via the horn 5 to cause flexural vibration. Do. When the vibrating bodies 2a and 2b bend and vibrate, sound waves are emitted from the vibrating bodies 2a and 2b.
[0026]
The object 3 is levitated from the surfaces of the vibrating bodies 2a and 2b by the radiation pressure of the sound waves emitted from the vibrating bodies 2a and 2b. Radiation pressure acts diagonally on the object 3 from both vibrating bodies 2a, 2b, and the object 3 is stably levitated in a state where the horizontal component forces facing each other are balanced. The floating height is several tens to several hundreds μm.
[0027]
When the vibrating bodies 2a and 2b vibrate in a state of being inclined downward toward the center of the object 3, the space between the vibrating bodies 2a and 2b and the object 3 is directed inward from the edges 4a and 4b. Air flows A1 and A2 are generated, and the air flows A1 and A2 apply a horizontal force to the object 3. When the edges 4a and 4b of the vibrating bodies 2a and 2b and the edges 3a and 3b of the object 3 are aligned, the action of the air flow is increased.
[0028]
When radiation pressure is applied in a direction perpendicular to the bottom surface of the object 3 as in a conventional object levitation device configured to levitate a flat plate, when an external force is applied to the object 3 in the horizontal direction, the object 3 is caused by the force. It easily moves horizontally and falls off the position facing the vibrating body. However, in this embodiment, since there are horizontal forces facing each other due to the air flows A1 and A2, the object 3 remains in a stable state at a predetermined position as long as a small horizontal external force acts on the object 3. This is because an external force acts on the object 3 in a state where the horizontal forces of the airflows A1 and A2 against the object 3 are balanced. For example, when the object 3 is moved in a direction that protrudes outside the vibrating body 2a, 3, the force of the air flow A1 on the side of the vibrating body 2a acting on the power source 3 increases, and the force of the air flow A2 on the side of the vibrating body 2b decreases. As a result, a force is applied to the object 3 so as to move to the vibrating body 2b side, that is, to return to the original position, and when no external force is applied, the object 3 returns to the original position.
[0029]
This embodiment has the following effects.
(1) A pair of vibrators 2a and 2b are arranged such that the surfaces thereof are inclined inward in the opposite direction with respect to the bottom surface of the flat object 3 and the radiation pressure acting on the object 3 is balanced. did. As a result, airflows A1 and A2 from the edges 4a and 4b to the inside are generated in the space sandwiched between the vibrating bodies 2a and 2b and the object 3, and the object 3 floats to a predetermined position in a stable state. Held in a state. In addition, a cover that restricts the movement of the object 3 in the width direction (the direction orthogonal to both vibrating bodies 2a and 2b) is provided, or the object floating device is activated by detecting that the object has moved in the width direction by a predetermined amount or more. It is possible to eliminate the need for preventive measures such as stopping the fall.
[0030]
(2) The pair of vibrating bodies 2 a and 2 b are arranged such that the edges 4 a and 4 b on the side away from each other extend along the edges 4 a and 4 b in the vicinity of the facing edges 3 a and 3 b of the object 3. Therefore, as compared with the case where the edges 3a, 3b and the edges 4a, 4b are separated from each other, the air flows A1, A2 are stronger, and the function of holding the object in a predetermined position is enhanced.
[0031]
(3) The front end surface 5a of the horn 5 is formed on a plane orthogonal to the axial direction of the vibrator 6, and the horn 5 and the vibrator 6 are at a predetermined angle θ between the horizontal plane and the vibrating bodies 2a and 2b with respect to the vertical direction. It is arranged in a state inclined at the same angle. Therefore, it is not necessary to process the vibrating bodies 2a and 2b so that the thicknesses differ depending on the location, and the manufacturing is simplified.
[0032]
(4) Since the flat plate-like object 3 having the opposite edges 3a and 3b parallel to each other can be floated and held in a stable state, for example, a liquid crystal substrate or the like can be transported while being floated and held without using a case.
[0033]
(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. In this embodiment, the point that the object 3 is large and the point that the object levitation apparatus 1 is provided with means for traveling the levitated object 3 are greatly different from the above-described embodiment. Parts that are basically the same as in the above embodiment are given the same reference numerals, and detailed description thereof is omitted.
[0034]
FIG. 3A is a rear view of the object levitation apparatus 1, that is, FIG. 3B viewed from above. A pair of vibrating bodies 2a, 2b, 2c for applying radiation pressure to the flat object 3 are provided, and are arranged in an inclined state with respect to the object 3, as shown in FIG. A third vibrating body 2c is arranged at the center of 2a, 2b so as to extend in parallel with the bottom surface of the object 3 and in parallel with both vibrating bodies 2a, 2b. As shown in FIG. 3B, the vibrating bodies 2a, 2b, and 2c are fastened to the horn 5 at both ends. The vibrating body 2c is formed wider than both vibrating bodies 2a and 2b, and a horn 5 to which the vibrating body 2c is fastened has a slit 5b extending in the vertical direction.
[0035]
The vibrator 6 for exciting the horn 5 fastened to one end of each vibrating body 2a, 2b, 2c is connected to an oscillator 10 (shown only in FIG. 3B). The vibrator 6 that excites the horn 5 fastened to the other end of each of the vibrating bodies 2a, 2b, and 2c is connected to a load circuit 11 that is an energy conversion means including a resistor R and a coil L.
[0036]
In the apparatus of this embodiment, when the vibrator 6 connected to the oscillator 10 is excited, the vibrating bodies 2a, 2b, 2c are flexed and vibrated through the horn 5, and the object 3 is on the vibrating bodies 2a, 2b, 2c. Levitating at. The vibrations of the vibrating bodies 2a, 2b, and 2c are transmitted to the vibrator 6 connected to the load circuit 11, and the vibration energy that is mechanical energy is converted into electric energy by the piezoelectric elements 7a and 7b that constitute the vibrator 6. . This electrical energy is converted into Joule heat by the resistance R of the load circuit 11 and is dissipated. Therefore, the vibration wave generated in each vibrating body 2a, 2b, 2c becomes a traveling wave, and the object 3 is conveyed in a floating state from the side corresponding to the vibrator 6 on the side connected to the oscillator 10 to the other side. The conveyance is stopped by stopping the driving of the oscillator 10.
[0037]
This embodiment has the following effects in addition to the effects (1) to (4) of the first embodiment.
(5) Since the vibrating body 2c disposed in parallel with the object 3 is provided at the center of the vibrating bodies 2a and 2b inclined in opposite directions, the bending of the object 3 is suppressed even if the width of the object 3 is wide. Then, it is smoothly transported while being kept floating.
[0038]
(6) As a means for moving the object 3 in a levitated state, the vibrators 2a, 2b, 2c are configured to generate a traveling wave that travels in a certain direction, so that the vibrators 2a, 2b, 2c bend to become standing waves. The configuration is simplified compared to a configuration in which an object is levitated by vibration and the compressed air is jetted onto the object 3 to travel.
[0039]
(7) When the object 3 is transported, the movement in the width direction is effectively restricted by the action of the airflows A1 and A2 from the edges 4a and 4b to the inside. And a mechanism for preventing the displacement of the object 3 in the width direction and holding it within a predetermined range by providing an air or sound wave reflecting member disclosed in Japanese Patent Application Laid-Open No. 7-137824 outside the vibrating bodies 2a and 2b. It becomes unnecessary.
[0040]
(8) Although the three vibrators 2a, 2b, and 2c are arranged, if the position adjustment of the vibrators 2a and 2b arranged on both sides is performed accurately, the position adjustment of the center vibrator 2c is about the difference. It does not have to be performed accurately, and adjustment of initial installation is simplified as compared with a conventional apparatus in which all the vibrators are arranged parallel to the bottom surface of the object.
[0041]
The embodiment is not limited to the above, and may be embodied as follows, for example.
As shown in FIGS. 4 (a) and 4 (b), the front end surface 5a of the horn 5 is placed in a horizontal plane with respect to the horizontal plane and the vibrators 2a and 2b with the vibrator 6 arranged in a vertical direction. And the horn 5 and the vibrator 6 are arranged so as to extend in the vertical direction. In this case, by fixing the vibrator 6 to a frame or the like so as to be vertical, the angle formed between the horizontal plane and the vibrating bodies 2a and 2b becomes the predetermined angle θ, and the horn 5 and the whole vibrator 6 are inclined by the predetermined angle θ. Work is easier than installing.
[0042]
○ When levitating a large object 3, particularly a wide object 3, the number of vibrating bodies 2 c provided between the vibrating bodies 2 a and 2 b provided on both sides in the width direction of the object is set to It is good also as two or more according to the space | interval of 2b. Further, as shown in FIGS. 5A and 5B, vibrators 2d and 2e that are inclined in opposite directions may be disposed between the vibrators 2a and 2b. As in the case of the vibrating bodies 2a and 2b, the method of inclining the vibrating bodies 2d and 2e is performed by inclining the horn 5 and the entire vibrator 6 by a predetermined angle with respect to the vertical direction as shown in FIG. There are a method of disposing and a method of FIG. 5B in which the front end surface 5a of the horn 5 is inclined. In these cases, the effect of holding the object 3 at a predetermined position is improved as compared with the case where the vibrating body 2c is disposed horizontally between the vibrating bodies 2a and 2b.
[0043]
The vibrating bodies 2a, 2b, 2d, 2e arranged in an inclined state are not necessarily limited to the configuration in which the same shape is arranged in pairs, and the numbers on the left and right are different as shown in FIG. As a whole, any structure may be used as long as the balance of the force of the airflow acting in the horizontal direction is achieved.
[0044]
The edges 4a and 4b of the vibrators 2a and 2b arranged on both sides are not necessarily arranged at positions aligned with the edges 3a and 3b of the object 3, and the object 3 has a size that protrudes from both edges 4a and 4b. Alternatively, the size may be such that the object 3 is located inside both edges 4a and 4b.
[0045]
A structure in which the object 3 is levitated by a pair of vibrating bodies 2a and 2b and a vibrating body 2c disposed horizontally between the pair of vibrating bodies 2a and 2b or vibrating bodies 2d and 2e disposed in an inclined state are provided. Any of the above configurations may be applied to either a configuration in which the object 3 is simply held in a floating state or a configuration in which a traveling wave is generated and the object 3 is conveyed in a floating state.
[0046]
In the apparatus for transporting the object 3 in a levitated state using traveling waves as in the second embodiment, each vibration is replaced with a method for stopping the driving of the oscillator 10 as a method for stopping the transport of the object 3. The vibrators 6 provided at both ends of the bodies 2a, 2b, and 2c are configured to be selectively switchable to the oscillator 10 and the load circuit 11, respectively. Then, the state connected to the oscillator 10 and the state connected to the load circuit 11 are switched at high speed, and the traveling direction of the traveling wave is switched in a short time, so that the object 3 is substantially floated. You may make it stop at a fixed position. In this case, the object 3 can be held in a levitating state even when stopped.
[0047]
○ As a means for moving the object 3 in the levitation state, instead of the configuration in which the vibration wave generated in the vibration bodies 2a to 2e becomes a traveling wave, the vibration wave generated in the vibration bodies 2a to 2e is a standing wave, It is good also as a structure which sprays compressed air with respect to the object 3 of this, or radiates | emits an ultrasonic wave and makes the object 3 drive | work. This configuration is disclosed in JP-A-7-137824.
[0048]
○ As long as the object has a shape with a flat bottom and opposing edges, the object is not limited to a flat object and can stably hold objects of other shapes in a levitated state.
The fixing of the vibrating bodies 2a to 2e to the horn 5 is not limited to fastening with screws, and an adhesive may be used, or may be fixed by brazing or welding.
[0049]
The vibrator 6 is not limited to the Langevin type vibrator, and other vibrators may be used.
The shape of the horn 5 is not limited to a flat rectangular parallelepiped shape, and may be a shape with a narrowed tip side such as a truncated cone shape.
[0050]
Technical ideas (inventions) other than the claims that can be grasped from the embodiment will be described below together with the effects thereof.
(1) The object levitation apparatus according to any one of claims 1 to 4 includes traveling means for traveling an object in a levitation state. In this case, the object can be conveyed in a levitated state.
[0051]
(2) In the invention of (1), the traveling means includes two vibrators fixed to both ends of each vibrator, an oscillator for exciting one vibrator of the two vibrators, and the other vibration. Energy conversion means connected to the child for converting vibration energy into electric energy and generating a traveling wave in the vibrating body. In this case, the object can be conveyed in a floating state with a simple configuration.
[0052]
【The invention's effect】
As described in detail above, according to the first to fourth aspects of the invention, an object having a flat bottom surface such as a flat plate can be levitated and held in a stable state.
[0053]
In the invention described in claim 2, the function of holding the object in a predetermined position is enhanced.
In the invention according to claim 4, it is easier to install the horn and the vibrator so that the angle formed by the horizontal surface and the vibrating body becomes a predetermined angle compared to the case where the horn and the entire vibrator are inclined at a predetermined angle. Become.
[Brief description of the drawings]
FIG. 1A is a schematic plan view of an object levitation apparatus according to a first embodiment, and FIG. 1B is a schematic front view of the same.
FIG. 2 is a schematic perspective view showing a fixed state of a vibrating body and a horn.
3A is a schematic rear view of an object levitation apparatus according to a second embodiment, and FIG. 3B is a schematic plan view of the same.
4A and 4B are schematic front views of an object levitation apparatus according to another embodiment, respectively.
FIGS. 5A and 5B are schematic front views of an object levitation apparatus according to another embodiment. FIG.
FIG. 6 is a schematic front view of an object levitation device according to another embodiment.
FIG. 7 is a partial cross-sectional view of a conventional object levitation device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Object levitation apparatus, 2a-2e ... Vibrating body, 3 ... Object, 3a, 3b, 4a, 4b ... Edge, 5 ... Horn which comprises excitation means, 6 ... Similarly vibrator, 5a ... Tip surface, 10 ... Excitation An oscillator constituting the means.

Claims (4)

An object levitation device that excites a flat vibrating body with an excitation means and levitates an object having a flat bottom surface on the surface of the vibrating body by the radiation pressure of sound waves of the vibrating body,
Arranging at least one set of vibrating bodies in a state in which the surface thereof is inclined inward in the opposite direction with respect to the bottom surface of the object, and the radiation pressure acting on the object is balanced ;
An object levitation apparatus in which an inclination angle of the vibrating body is set such that an angle formed between a horizontal plane and the surface of the vibrating body is 3 ° or less with respect to a horizontal plane . 2. The object levitation apparatus according to claim 1, wherein the pair of vibrators are arranged such that edges on the sides away from each other extend along the edges in the vicinity of the opposing edges of the object. The excitation means includes a horn attached to the tip so that the vibrating body can vibrate integrally, the tip end surface of the horn is formed in a plane perpendicular to the axial direction of the vibrator, and the horn and the vibrator are in a vertical direction, The object levitation apparatus according to claim 1, wherein the object levitation apparatus is disposed in a state where the angle is the same as an angle formed by the horizontal plane and the vibrating body. The excitation means includes a horn having the vibrating body attached to the tip thereof so that the vibrator can vibrate integrally, and the tip surface of the horn is arranged so that the vibrator extends in the vertical direction, The object levitation apparatus according to claim 1 or 2, wherein the levitation device is formed so as to be inclined at the same angle as the angle formed by the horn and the horn and the vibrator so as to extend in a vertical direction.

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