Patent Description:
An actuator which winds a tensioned dielectric elastomer soft actuator around a spring and expand and contract or bend to be deformed by application of a voltage is suggested (refer to, for example, Patent Document <NUM>). This actuator is characterized in generating large displacement having a small size and a light weight.

Patent Document <NUM> discloses a flexible actuator attached to the tip of a catheter.

Patent Document <NUM> describes a bendable portion for an endoscope including a bending mechanism.

Patent Document <NUM> relates to an endoscope insertion aiding device which has a flexible tube.

Patent Document <NUM> describes a deflection cover for a medical endoscope comprising a tubular covering that protects an articulation system of the endoscope.

Patent Document <NUM> discloses an insertion aid for an endoscope which can be arranged at a distal end of the endoscope tube.

Patent Document <NUM> relates to the field of inflatable devices capable of self propelled motion through tubes, especially for endoscopic and vascular use.

Patent Document <NUM> discloses a bending device including a bendable unit which has a bendable body extending in a direction and a soft pipe extending in the same direction and fixed to the bendable body. The soft pipe is stretchable in said direction relative to the bendable body in response to changes of pressure inside the soft pipe, which results in the bendable body and the soft pipe bending.

Patent Document <NUM> relates to a respiratory hose for delivering a breathing air flow to a patient and that can be easily collapsed to a shorter length for the purpose of packing and/or storing, when not in use.

However, the actuator described above might cause insulation breakdown.

An object of the present technology is to provide an actuator, an actuator module, an endoscope, an endoscope module, and a controlling method capable of improving insulation resistance.

According to a first aspect the invention provides an actuator module in accordance with claim <NUM>. According to a second aspect the invention provides an endoscope module in accordance with claim <NUM>. All further aspects are set forth in the dependent claims, the drawings, and the following description.

The following first, second, fifth and sixth technologies are not according to the invention and are present for illustration purposes only.

In order to solve the above problem, a first technology is an actuator provided with a tubular actuator element, and a supporting body which supports an inner peripheral surface of the actuator element, in which an internal pressure of the actuator element is higher than an external pressure of the actuator element.

A second technology is an endoscope provided with the actuator of the first technology.

A third technology is an actuator module as defined in claim <NUM> provided, inter alia, with an actuator including a tubular actuator element, and a supporting body which supports an inner peripheral surface of the actuator element, a control unit which controls drive of the actuator, and a pressurizing unit which pressurizes an internal space of the actuator.

A fourth technology is an endoscope module as defined in claim <NUM> provided with the actuator module of the third technology.

A fifth technology is an actuator provided with an actuator element, and a supporting body which supports the actuator element, in which an internal pressure of the actuator element is higher than an external pressure of the actuator element.

A sixth technology is a controlling method provided with detecting a pressure in an internal space of an actuator, and pressurizing the internal space of the actuator on the basis of a result of the detection.

According to the present technology, insulation resistance of the actuator may be improved.

The embodiments of the present technology are described in the following order.

In order to figure out a cause of occurrence of insulation breakdown, the inventors of the present invention performed finite element method (FEM) analysis regarding an actuator provided with a tubular actuator element and a coil spring (supporting body) which supports an inner peripheral surface of the actuator element. As a result, the following was found. In other words, in the actuator having the above-described configuration, the actuator element covering a side surface of the coil spring bites into a space between the coil spring and a constriction might occur on the side surface of the actuator element. When such constriction occurs, a thickness of the actuator element becomes nonuniform, and the insulation breakdown tends to occur at a portion where the thickness is small.

Therefore, the inventors of the present invention conducted intensive studies to suppress the constriction occurring on the side surface of the actuator element. As a result, a configuration in which an internal pressure of the actuator is made higher than an external pressure of the actuator was found. Hereinafter, the actuator having such a configuration is described.

An actuator <NUM> according to a first embodiment of the present technology is a so-called electrostrictive actuator, and is provided with a cylindrical actuator element <NUM>, a cylindrical coil spring <NUM> which supports an inner peripheral surface of the actuator element <NUM>, and sealing members <NUM> and <NUM> which close openings at both ends of the actuator element <NUM> as illustrated in <FIG>. The actuator <NUM> may further be provided with a cylindrical protective layer not illustrated which covers an outer peripheral surface of the actuator element <NUM>.

The actuator <NUM> is suitably used in a medical instrument such as an endoscope, an industrial instrument, an electronic device, a speaker, an artificial muscle, a robot, a robot suit and the like. The actuator <NUM> may be continuously usable or disposable. In a case where the actuator <NUM> is applied to the medical instrument such as the endoscope, it is preferable that the actuator <NUM> is disposable from a hygienic viewpoint.

The actuator <NUM> includes a sealed cylindrical internal space and the coil spring <NUM> is provided in the internal space. The internal space is filled with gas as a fluid. The gas is at least one type of air, a rare gas, carbon dioxide and the like, for example. An internal pressure of the actuator <NUM> is higher than an external pressure of the actuator <NUM>. For this reason, it is possible to suppress occurrence of constriction as indicated by a dashed-two dotted line in <FIG> on the peripheral surface of the actuator element <NUM>, so that insulation resistance of the actuator <NUM> may be improved. In this specification, the pressure in the internal space of the actuator <NUM> is referred to as the internal pressure of the actuator <NUM>, and the pressure of the external space of the actuator element <NUM> is referred to as the external pressure of the actuator <NUM>.

Hereinafter, the actuator element <NUM>, the coil spring <NUM>, the sealing members <NUM> and <NUM>, and the protective layer included in the actuator <NUM> are sequentially described.

The actuator element <NUM> has a sheet shape. The actuator element <NUM> may be formed into a cylindrical shape in advance, or may be wound around the coil spring <NUM> to have the cylindrical shape.

The actuator element <NUM> is a so-called dielectric elastomer actuator element and is provided with, as illustrated in <FIG>, a cylindrical dielectric layer 11a, a plurality of electrodes (first electrodes) 11b provided on an inner peripheral surface of the dielectric layer 11a, and a plurality of electrodes (second electrodes) 11c provided on an outer peripheral surface of the dielectric layer 11a. The electrode 11b may be directly formed on the inner peripheral surface of the dielectric layer 11a or may be bonded via a bonding layer. Furthermore, the electrode 11c may be directly formed on the outer peripheral surface of the dielectric layer 11a or may be bonded via a bonding layer. Herein, an adhesive layer is defined as one type of the bonding layer.

The dielectric layer 11a is a sheet having a stretching property. The dielectric layer 11a includes, for example, an insulating elastomer as an insulating stretching material. The dielectric layer 11a may contain an additive as necessary. As the additive, for example, one or more types of a crosslinking agent, a plasticizer, an antioxidant, a surfactant, a viscosity adjusting agent, a reinforcing agent, a coloring agent and the like may be used. As the insulating elastomer, for example, an elastomer containing one or more types of acrylic rubber, silicone rubber, ethylene-propylene-diene terpolymer (EPDM), natural rubber (NR), butyl rubber (IIR), isoprene rubber (IR), acrylonitrile-butadiene copolymer rubber (NBR), hydrogenatedacrylonitrile-butadiene copolymer rubber (H-NBR), hydrin rubber, chloroprene rubber (CR), fluororubber, urethane rubber, and the like may be used. Pre-strain may be applied to the dielectric layer 11a.

The electrodes 11b and 11c are opposed to each other with the dielectric layer 11a interposed therebetween and extend in a height direction of the actuator element <NUM>. A plurality of electrodes 11b and a plurality of electrodes 11c are arranged at regular intervals in a circumferential direction of the dielectric layer 11a. <FIG> illustrate an example in which four electrodes 11b and four electrodes 11c are arranged at regular intervals in the circumferential direction of the dielectric layer 11a. A wire not illustrated is connected to the electrodes 11b and 11c, and voltage is applied between the electrodes 11b and 11c opposed to each other with the dielectric layer 11a interposed therebetween.

The electrodes 11b and 11c are thin films having a stretching property. Since the electrodes 11b and 11c have the stretching property, the electrodes 11b and 11c may be deformed following deformation of the dielectric layer 11a. The electrodes 11b and 11c may be any of thin films produced by either a dry process or a wet process. The electrodes 11b and 11c include a conductive material and a binder (binding agent) as necessary. The electrodes 11b and 11c may further include an additive as necessary.

The conductive material may also be a conductive particle. A shape of the conductive particle may be, for example, a spherical shape, an ellipsoidal shape, a needle shape, a plate shape, a scale shape, a tubular shape, a wire shape, a bar shape (rod shape), an irregularly shape, and the like, but the shape is not especially limited thereto. Note that two or more types of particles having the above-described shape may be used in combination.

As the conductive material, one or more types of metal, a metal oxide, a carbon material, and a conductive polymer may be used. Here, it is defined that the metal includes semi metal. The metal includes metal such as copper, silver, gold, platinum, palladium, nickel, tin, cobalt, rhodium, iridium, steel, ruthenium, osmium, manganese, molybdenum, tungsten, niobium, tantalum, titanium, bismuth, antimony, and lead, an alloy thereof or the like, for example; however, the metal is not limited thereto. The metal oxide includes an indium tin oxide (ITO), a zinc oxide, an indium oxide, an antimony-added tin oxide, a fluorine-added tin oxide, an aluminum-added zinc oxide, a gallium-added zinc oxide, a silicon-added zinc oxide, a zinc oxide-tin oxide system, an indium oxide-tin oxide system, a zinc oxide-indium oxide-magnesium oxide system and the like, for example; however, the metal oxide is not limited thereto.

The carbon material includes carbon black, porous carbon, carbon fiber, fullerene, graphene, a carbon nanotube, a carbon micro coil, nanohorn and the like, for example; however, the material is not limited thereto. As the conductive polymer, for example, a conductive polymer such as a linear conjugated system, an aromatic conjugated system, a mixed conjugated system, a heterocyclic conjugated system, a hetero atom-containing conjugated system, a double stranded conjugated system, or a two-dimensional conjugated system; however, the polymer is not limited thereto.

As the binder, it is preferable to use at least one type of an elastomer, a gel, and oil. This is because the stretching property may be imparted to the electrodes 11b and 11c. As the elastomer, for example, one or more types of silicone-based, acrylic-based, urethanebased, and styrene-based elastomers and the like may be used. As the additive, for example, one or more types of a crosslinking agent, a plasticizer, an antioxidant, a surfactant, a viscosity adjusting agent, a reinforcing agent, a coloring agent and the like may be used.

The electrodes 11b and 11c may include a composite material of the conductive polymer and a block copolymer. Specific examples of the composite material include a composite material of polyaniline and styrene-ethylene butylene-styrene (SEBS) copolymer. Furthermore, the electrodes 11b and 11c may contain a polymer gel material and an electrolyte. As a specific example of a combination of these materials, there may be a combination of a polyacrylamide gel and a LiF aqueous solution.

The coil spring <NUM> is an example of a supporting body which may be curved in an arbitrary direction and elastically deformed. The coil spring <NUM> is a coil-shaped spring obtained by winding a linear member such as a metal wire into a cylindrical spiral shape, and a space is formed between the linear member. Therefore, the coil spring <NUM> supports the inner peripheral surface of the actuator element <NUM> discretely in the height direction of the actuator element <NUM>. By thus supporting the inner peripheral surface of the actuator element <NUM>, the actuator element <NUM> is easily deformed, and the actuator <NUM> may easily perform expanding operation and bending operation. Here, "the inner peripheral surface of the actuator element <NUM> is supported discretely in the height direction of the actuator element <NUM>" means that the inner peripheral surface of the actuator element <NUM> is supported at separated positions in the height direction of the actuator element <NUM>. Here, intervals between the separated positions may be constant or may be changed.

The sealing members <NUM> and <NUM> have a disk shape. The sealing members <NUM> and <NUM> include metal or a polymer material. The sealing members <NUM> and <NUM> may include an elastomer and the like and elastically deformable. The sealing members <NUM> and <NUM> may be a device (for example, an electronic device such as a camera) provided at an end of the actuator <NUM> or an operating unit of the actuator <NUM>.

The protective layer is for protecting the electrode 11c and is a sheet having a stretching property. The protective layer contains a polymer resin having an insulating property. As the polymer resin, for example, vinyl chloride may be used. In the actuator <NUM> according to the first embodiment, the occurrence of the constriction in the actuator element <NUM> is suppressed, so that entry of air between the outer peripheral surface and the protective layer of the actuator element <NUM> may be suppressed.

An example of the operation of the actuator <NUM> according to the first embodiment of the present technology is described below.

When drive voltage is applied between the electrodes 11b and 11c opposed to each other with the dielectric layer 11a interposed therebetween, an attractive force due to the Coulomb force is applied to both the electrodes 11b and 11c. Therefore, the dielectric layer 11a arranged between the electrodes 11b and 11c is pressed in a thickness direction thereof to become thin and stretched.

On the other hand, when the drive voltage applied between the electrodes 11b and 11c opposed to each other with the dielectric layer 11a interposed therebetween is canceled, no attractive force due to the Coulomb force acts on the electrodes 11b and 11c. Therefore, due to a restoring force of the dielectric layer 11a, the dielectric layer 11a has its original thickness and contracts to return to its original size.

In a case where the drive voltage is applied to one set of electrodes 11b and 11c out of a plurality of sets of electrodes 11b and 11c opposed to each other with the dielectric layer 11a interposed therebetween, the actuator <NUM> bends by the stretch of the dielectric layer 11a arranged between the electrodes 11b and 11c. When the drive voltage applied to one set of electrodes 11b and 11c is canceled, the actuator <NUM> returns to its original cylindrical shape.

Next, a method of manufacturing the actuator <NUM> is described. First, a rectangular actuator element <NUM> is wound around a peripheral surface of the coil spring <NUM> to form a tubular shape, or the coil spring <NUM> is inserted into the actuator element <NUM> formed in advance in the tubular shape. The constriction occurs on the peripheral surface of the actuator element <NUM> after the winding or insertion.

Next, one opening of the actuator element <NUM> is closed by fitting the sealing member <NUM> into one opening of the actuator element <NUM> and the like. Next, the other opening of the actuator element <NUM> is closed by fitting the sealing member <NUM> into the other opening of the actuator element <NUM> and the like. As a result, the actuator <NUM> having the sealed internal space is obtained. Next, a gas injection means such as a syringe is stuck into one of the sealing members <NUM> and <NUM>, gas is injected into the internal space of the actuator <NUM> to increase the internal pressure of the actuator <NUM> to be higher than the external pressure, and thereafter the gas injection means is pulled out. As a result, the actuator <NUM> illustrated in <FIG> in which the constriction on the peripheral surface of the actuator element <NUM> is suppressed may be obtained.

In the actuator <NUM> according to the first embodiment, since the internal pressure of the actuator <NUM> is higher than the external pressure of the actuator <NUM>, the occurrence of the constriction on the actuator element <NUM> may be suppressed (refer to <FIG>). This makes it possible to suppress nonuniformity of the thickness of the actuator element <NUM>. Therefore, the insulation resistance of the actuator <NUM> may be improved.

Furthermore, by suppressing the constriction of the actuator element <NUM>, the following effect is also obtained.

A deformation amount (bending amount) per electric field strength of the actuator <NUM> may be improved.

A side surface of the actuator <NUM> becomes smoother, so that the side surface of the actuator <NUM> is less likely to be caught by the surroundings during use. Therefore, in a case where the actuator <NUM> is applied to the endoscope, operability of the endoscope is improved such that the endoscope is easily inserted into a human body or the like.

In a case where surface treatment by spray coating and the like is applied to the side surface of the actuator element <NUM>, the surface treatment may be performed more uniformly.

Since the constriction of the actuator element <NUM> may be suppressed without adding a part having a weight, the above-described effect may be obtained without deteriorating bendability of the actuator <NUM>.

Although the configuration of using the coil spring <NUM> as the supporting body is described in the first embodiment, the supporting body is not limited to the coil spring <NUM>, and the supporting body may be used as long as this may support the inner peripheral surface of the actuator element <NUM> discretely in the height direction of the actuator element <NUM>. An example of the supporting body other than the coil spring <NUM> is hereinafter described.

As illustrated in <FIG>, the actuator <NUM> may be provided with a connected body <NUM> including a plurality of supporting units 21a and a plurality of joint mechanisms 21b in place of the coil spring <NUM>. The plurality of supporting units 21a supports the inner peripheral surface of the actuator element <NUM> discretely in the height direction of the actuator element <NUM>. The joint mechanism 21b has, for example, a spherical shape and connects adjacent supporting units 21a so as to be rotatable in an arbitrary direction. Note that the joint mechanism 21b may be a part of the supporting unit 21a.

As illustrated in <FIG>, the actuator <NUM> may be provided with a connected body <NUM> including a plurality of disk-shaped supporting units 22a and a plurality of ball joint mechanisms 22b in place of the coil spring <NUM>. The plurality of ball joint mechanisms 22b connects adjacent supporting units 22a so as to be rotatable in an arbitrary direction. The plurality of supporting units 22a is provided so as to be spaced apart from each other by a predetermined distance and supports the inner peripheral surface of the actuator element <NUM> discretely in the height direction of the actuator element <NUM>. A shaft portion 22c is perpendicularly erected at the center of one surface of the supporting unit 22a, and a spherical portion (so-called ball stud) 22d is provided at a tip end thereof. On the other hand, a shaft portion 22e is perpendicularly erected at the center of the other surface of the supporting unit 22a, and a socket 22f which is in spherical contact with the spherical portion 22d is provided at a tip end thereof. The socket 22f is in spherical contact with the spherical portion 22d to support the spherical portion 22d so as to be rotatable in an arbitrary direction. The spherical portion 22d and the socket 22f form the ball joint mechanism 22b. The openings at both ends of the actuator element <NUM> are closed by the supporting units 22a.

As illustrated in <FIG>, the actuator <NUM> may be provided with a connected body <NUM> including a plurality of disk-shaped supporting units 23a and a plurality of joint mechanisms 23b imitating a joint structure of a human body in place of the coil spring <NUM>. The plurality of joint mechanisms 23b connects adjacent supporting units 23a so as to be rotatable in an arbitrary direction. The plurality of supporting units 23a is provided so as to be spaced apart from each other by a predetermined distance and supports the inner peripheral surface of the actuator element <NUM> discretely in the height direction of the actuator element <NUM>. A shaft portion 23c is perpendicularly erected at the center of one surface of the supporting unit 23a, and a spherical portion (so-called ball stud) 23d is provided at a tip end thereof. On the other hand, a shaft portion 23e is also perpendicularly erected at the center of the other surface of the supporting unit 23a, and a spherical portion (so-called ball stud) 23f is provided at a tip end thereof. The spherical portions 23d and 23f abut each other so as to be rotatable in an arbitrary direction. By adopting a configuration in which the spherical portions 23d and 23f abut in this manner, friction during rotation may be reduced. Furthermore, the abutted spherical portions 23d and 23f are covered with a membrane <NUM>. By covering the spherical portions 23d and 23f with the membrane <NUM> in this manner, it is possible to suppress displacement between the abutted spherical portions 23d and 23f. An inner side of the membrane <NUM> may be filled with liquid, a gel and the like. The spherical portions 23d and 23f and the membrane <NUM> form the joint mechanism 23b. The openings at both ends of the actuator element <NUM> are closed by the supporting units 23a.

As illustrated in <FIG>, the actuator <NUM> may be provided with a connected body <NUM> including a plurality of disk-shaped supporting units 24a and a plurality of joint mechanisms 24b imitating a joint structure of insects in place of the coil spring <NUM>. The joint mechanism 24b connects adjacent supporting units 24a so as to be rotatable in an arbitrary direction. The plurality of supporting units 24a is provided so as to be spaced apart from each other by a predetermined distance and supports the inner peripheral surface of the actuator element <NUM> discretely in the height direction of the actuator element <NUM>. A shaft portion 24c is perpendicularly erected at the center of one surface of the supporting unit 24a, and a shaft portion 24d is perpendicularly erected also at the center of the other surface of the supporting unit 24a. Tip ends of the shaft portions 24c and 24d are separated by a predetermined distance, and the tip ends of the shaft portions 24c and 24d are connected by an elastic body 24e. Therefore, the shaft portions 24c and 24d are rotatable in an arbitrary direction. The elastic body 24e is of a material of low rigidity (material of high flexibility) such as an elastomer, a cushion material, or a spring. The shaft portions 24c and 24d and the elastic body 24e form the joint mechanism 24b. The openings at both ends of the actuator element <NUM> are closed by the supporting units 24a.

As illustrated in <FIG>, the actuator <NUM> may be provided with a connected body <NUM> including a plurality of disk-shaped supporting units 25a and a plurality of joint mechanisms 25b imitating a joint structure of a human body in place of the coil spring <NUM>. The plurality of joint mechanisms 25b connects adjacent supporting units 25a so as to be rotatable in an arbitrary direction. The plurality of supporting units 25a is provided so as to be spaced apart from each other by a predetermined distance and supports the inner peripheral surface of the actuator element <NUM> discretely in the height direction of the actuator element <NUM>. Between the adjacent supporting units 25a, a bar-shaped shaft portion 25c having a spherical portion 25d at one end and a spherical portion 25e at the other end is provided. The shaft portion 25c is a magnet in which a side on the spherical portion 25d is a north pole and a side of the spherical portion 25e is a south pole. The spherical portion 25d is located at the center of one surface of the supporting unit 25a and the spherical portion 25e is located at the center of the other surface of the supporting unit 25a. The spherical portions 25e and 25d having different polarities attract each other across the supporting unit 25a. Therefore, the shaft portion 25c adjacent across the supporting unit 25a may rotate in an arbitrary direction. The spherical portions 25e and 25d may be covered with a membrane 25f, but unlike the joint mechanism 23b illustrated in <FIG>, in the joint mechanism 25b, the spherical portions 25e and 25d attract by a magnetic force, so that it is not required that the spherical portions 25e are 25d are covered with the membrane 25f. The openings at both ends of the actuator element <NUM> are closed by the supporting units 25a.

As illustrated in <FIG>, the actuator <NUM> may also be provided with a supporting body <NUM> including a plurality of spherical bodies 26a accommodated in the tubular actuator element <NUM> in place of the coil spring <NUM>. The plurality of spherical bodies 26a is accommodated in the actuator element <NUM> such that the spherical bodies 26a adjacent to each other in the height direction of the actuator element <NUM> come into contact with each other. As a result, the inner peripheral surface of the actuator element <NUM> is supported discretely in the height direction of the actuator element <NUM> by the plurality of spherical bodies 26a, and the actuator <NUM> is rotatable in an arbitrary direction.

The actuator <NUM> may be provided with a supporting body including a polymer resin capable of supporting the inner peripheral surface of the actuator element <NUM> discretely in the height direction of the actuator element <NUM> in place of the coil spring <NUM>. As a specific example of the polymer resin, for example, there may be an insulating elastomer similar to that of the dielectric layer 11a.

As illustrated in <FIG>, a supporting body <NUM> including a polymer resin may include a plurality of supporting units 27a and a plurality of shaft portions 27b. The supporting unit 27a and the shaft portion 27b are integrally molded of the polymer resin. The supporting unit 27a has a disk shape and supports the inner peripheral surface of the actuator element <NUM> by an outer peripheral portion thereof. The shaft portion 27b connects the supporting units 27a adjacent to each other in the height direction of the actuator element <NUM>. The sealing members <NUM> and <NUM> and the supporting body <NUM> may be integrally molded of the polymer resin.

The actuator <NUM> may also be manufactured in the following manner. First, as illustrated in <FIG>, the actuator <NUM> is assembled in a state in which the coil spring <NUM> is stretched. At that time, a volume of the internal space of the actuator <NUM> is larger than the volume of the internal space of the actuator <NUM> finally obtained, and the constriction occurs on the side surface of the actuator element <NUM>. Next, as illustrated in <FIG>, the stretch of the coil spring <NUM> is released to reduce the volume of the internal space of the actuator <NUM>, thereby increasing the internal pressure of the actuator <NUM>. As a result, an intended actuator <NUM> in which the constriction on the peripheral surface of the actuator element <NUM> is suppressed is obtained.

Note that it is also possible to increase the internal pressure of the actuator <NUM> by reducing the volume of the internal space of the actuator <NUM> by pressurizing one or both ends of the actuator <NUM> to decrease a height of the actuator <NUM> after assembling the actuator <NUM> in a state in which the coil spring <NUM> is not stretched.

The actuator element <NUM> may also include stacked sheets of dielectric elastomer actuator elements. In this case, a plurality of dielectric elastomer actuator elements formed in advance into a cylindrical shape may be concentrically stacked around the coil spring <NUM>, or a single dielectric elastomer actuator element having a band shape may be wound around the coil spring <NUM> to be stacked. As described in the first embodiment, the occurrence of the constriction on the peripheral surface of the actuator element <NUM> is suppressed, so that it is possible to suppress entry of air between the stacked dielectric elastomer actuator elements in a case where the dielectric elastomer actuator elements are stacked.

The actuator <NUM> may also be provided with first and second electrodes provided on entire or substantially entire both surfaces of the dielectric layer 11a in place of the electrodes 11a and 11b.

In the first embodiment, the configuration in which the actuator element <NUM> and the coil spring <NUM> have the cylindrical shape is described as an example; however, the actuator element <NUM> and the coil spring <NUM> may have a rectangular tubular shape such as a square tubular shape.

The internal space of the actuator <NUM> may be filled with liquid or a solid in place of gas. Here, the liquid is, for example, water, saline solution, or the like. Furthermore, the solid is, for example, a sol, a gel, or the like.

As illustrated in <FIG>, an endoscope module according to a second embodiment of the present technology is provided with an endoscope <NUM>, a control unit <NUM>, a bending drive circuit <NUM>, an internal pressure detection circuit <NUM>, a pressurizing unit <NUM>, and a depressurizing unit <NUM>. The control unit <NUM> is connected to a power supply <NUM>. Note that, in the second embodiment, a portion similar to that in the first embodiment is assigned with the same reference sign and the description thereof is omitted.

The endoscope <NUM> is provided with an operating unit <NUM>, a supporting unit <NUM>, an actuator <NUM> being a bending unit, a tip end <NUM>, and a pressure-sensitive sensor <NUM>. The actuator <NUM>, the pressure-sensitive sensor <NUM>, the control unit <NUM>, the bending drive circuit <NUM>, the internal pressure detection circuit <NUM>, the pressurizing unit <NUM>, and the depressurizing unit <NUM> form an actuator module. The pressure-sensitive sensor <NUM> and the internal pressure detection circuit <NUM> form a detecting unit which detects a pressure in an internal space of the actuator <NUM>.

The operating unit <NUM> is provided with a button, a knob, and the like for operating the endoscope. The supporting unit <NUM> is provided between the operating unit <NUM> and the actuator <NUM> to support the actuator <NUM>. The supporting unit <NUM> has rigidity and is provided with a vent hole therein which connects the pressurizing unit <NUM> and the actuator <NUM>.

The actuator <NUM> is provided with an actuator element <NUM> and a coil spring <NUM>, and the internal space of the actuator <NUM> is sealed. One opening of the actuator element <NUM> is closed by the tip end <NUM> and an opening at the other end is closed by the supporting unit <NUM>. As illustrated in <FIG>, an illumination lens 34a and an objective lens 34b are provided on a tip end surface of the tip end <NUM>. A portion of the illumination lens 34a and the objective lens 34b on the surface of the tip end <NUM> is of, for example, stainless steel or the like. The illumination lens 34a and the objective lens 34b are, for example, glass lenses. An illumination device is provided inside the illumination lens 34a, and an imaging element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) is provided inside the objective lens 34b. The imaging element is connected to a display device not illustrated via an image processing unit not illustrated.

The tip end <NUM> and the operating unit <NUM> are connected to each other by a cable arranged in the internal space of the actuator <NUM>, and an operation signal is supplied from the operating unit <NUM> to the tip end <NUM> via this cable. Furthermore, the tip end <NUM> and the image processing unit are connected by a cable arranged in the internal space of the actuator <NUM>, and a video signal is supplied from the tip end <NUM> to the image processing unit via this cable. However, the operating unit <NUM> may wirelessly supply the operation signal to the tip end <NUM>, or the tip end <NUM> may wirelessly supply the video signal to the image processing unit.

The pressure-sensitive sensor <NUM> is arranged in a portion to close the opening on one end of the actuator element <NUM> out of the tip end <NUM>. However, an arrangement position of the pressure-sensitive sensor <NUM> is not limited to there as long as this is a position where the sensor may detect the internal pressure of the actuator <NUM>. The pressure-sensitive sensor <NUM> outputs an electric signal corresponding to the internal pressure of the actuator <NUM> to the internal pressure detection circuit <NUM>. As the pressure-sensitive sensor <NUM>, for example, a diaphragm gauge or the like may be used.

The internal pressure detection circuit <NUM> detects the internal pressure of the actuator <NUM> on the basis of the electric signal supplied from the pressure-sensitive sensor <NUM> and supplies the same to the control unit <NUM>. The pressurizing unit <NUM> is a pump, a regulator or the like, and supplies gas to the internal space of the actuator <NUM> under the control of the control unit <NUM> to pressurize the internal space of the actuator <NUM>. The gas is at least one type of air, a rare gas, carbon dioxide and the like, for example. The depressurizing unit <NUM> is a solenoid valve such as a diaphragm valve and discharges the gas in the internal space of the actuator <NUM> to decrease the pressure in the internal space of the actuator <NUM> under the control of the control unit <NUM>.

The control unit <NUM> controls the bending drive circuit <NUM> and the pressurizing unit <NUM> on the basis of the control signal supplied from the operating unit <NUM>. On the basis of the internal pressure supplied from the internal pressure detection circuit <NUM>, the control unit <NUM> feedback-controls the pressurizing unit <NUM> and the depressurizing unit <NUM> such that the internal pressure of the actuator <NUM> becomes a prescribed pressure. Here, the prescribed pressure is a pressure at which occurrence of constriction of the actuator <NUM> is suppressed. Note that, when the internal pressure of the actuator <NUM> is too high, there is a possibility that swelling might occur in the actuator element <NUM>, so that an upper limit value of the internal pressure of the actuator <NUM> is preferably a pressure at which the swelling of the actuator element <NUM> does not occur. The bending drive circuit <NUM> drives the actuator <NUM> to bend on the basis of the control signal supplied from the control unit <NUM>.

Next, with reference to <FIG>, a method of controlling the internal pressure at power on is described. First, when the power supply <NUM> is put on at step S11, the control unit <NUM> drives the pressurizing unit <NUM> at step S12 to pressurize the actuator <NUM>, thereby increasing the internal pressure of the actuator <NUM>. Next, at step S13, the internal pressure detection circuit <NUM> detects the internal pressure of the actuator <NUM> on the basis of the electric signal supplied from the pressure-sensitive sensor <NUM>, and supplies a detection result to the control unit <NUM>.

Next, at step S14, the control unit <NUM> determines whether or not the internal pressure of the actuator <NUM> reaches the prescribed pressure on the basis of the internal pressure supplied from the internal pressure detection circuit <NUM>. In a case where it is determined at step S14 that the internal pressure of the actuator <NUM> reaches the prescribed pressure, the control unit <NUM> stops the pressurizing unit <NUM> at step S15, and at step S16, the control unit <NUM> is put into a stand-by state for operation on the endoscope <NUM>. On the other hand, in a case where it is determined at step S14 that the internal pressure of the actuator <NUM> does not reach the prescribed pressure, the control unit <NUM> returns the process to step S12.

Next, with reference to <FIG>, a method of controlling the internal pressure at the time of operation is described. First, when the operation of the endoscope <NUM> is started at step S21, the internal pressure detection circuit <NUM> detects the internal pressure of the actuator <NUM> on the basis of the electric signal supplied from the pressure-sensitive sensor <NUM> at step S22, and supplies a detection result to the control unit <NUM>. Next, at step S23, the control unit <NUM> determines whether or not the internal pressure of the actuator <NUM> is lower than the prescribed pressure on the basis of the internal pressure supplied from the internal pressure detection circuit <NUM>.

In a case where it is determined at step S23 that the internal pressure of the actuator <NUM> is lower than the prescribed pressure, at step S24, the control unit <NUM> drives the pressurizing unit <NUM> to pressurize the interior of the actuator <NUM>, thereby increasing the internal pressure of the actuator <NUM>. Next, at step S25 the internal pressure detection circuit <NUM> detects the internal pressure of the actuator <NUM> on the basis of the electric signal supplied from the pressure-sensitive sensor <NUM>, and supplies a detection result to the control unit <NUM>.

Next, at step S26, the control unit <NUM> determines whether or not the internal pressure of the actuator <NUM> reaches the prescribed pressure on the basis of the internal pressure supplied from the internal pressure detection circuit <NUM>. In a case where it is determined at step S26 that the internal pressure of the actuator <NUM> reaches the prescribed pressure, at step S27, the control unit <NUM> stops the pressurizing unit <NUM> and returns the procedure to step S22. On the other hand, in a case where it is determined at step S26 that the internal pressure of the actuator <NUM> does not reach the prescribed pressure, the control unit <NUM> returns the process to step S24.

In a case where it is determined at step S23 that the internal pressure of the actuator <NUM> is not lower than the prescribed pressure, at step S28, the control unit <NUM> determines whether or not the internal pressure of the actuator <NUM> is higher than the prescribed pressure on the basis of the internal pressure supplied from the internal pressure detection circuit <NUM>. In a case where it is determined at step S28 that the internal pressure of the actuator <NUM> is higher than the prescribed pressure, at step S29, the control unit <NUM> drives the depressurizing unit <NUM> to depressurize the interior of the actuator <NUM>, thereby decreasing the internal pressure of the actuator <NUM>. On the other hand, in a case where it is determined at step S28 that the internal pressure of the actuator <NUM> is not higher than the prescribed pressure, the control unit <NUM> returns the procedure to step S22.

Next, at step S30, the internal pressure detection circuit <NUM> detects the internal pressure of the actuator <NUM> on the basis of the electric signal supplied from the pressure-sensitive sensor <NUM>, and supplies a detection result to the control unit <NUM>. Next, at step S31, the control unit <NUM> determines whether or not the internal pressure of the actuator <NUM> reaches the prescribed pressure on the basis of the internal pressure supplied from the internal pressure detection circuit <NUM>. In a case where it is determined at step S31 that the internal pressure of the actuator <NUM> reaches the prescribed pressure, at step S32, the control unit <NUM> stops the depressurizing unit <NUM> and returns the procedure to step S22. On the other hand, in a case where it is determined at step S31 that the internal pressure of the actuator <NUM> does not reach the prescribed pressure, the control unit <NUM> returns the process to step S29.

Since the endoscope module according to the second embodiment is provided with the pressurizing unit <NUM> for increasing the internal pressure of the actuator <NUM>, the internal pressure of the actuator <NUM> may be made higher than the external pressure of the actuator <NUM>. Therefore, an effect similar to that of the first embodiment may be obtained.

Furthermore, since the pressurizing unit <NUM> for increasing the internal pressure of the actuator <NUM> and the depressurizing unit <NUM> for decreasing the internal pressure of the actuator <NUM> are provided, the internal pressure of the actuator <NUM> may be adjusted to the prescribed pressure at the time of the operation of the endoscope module.

As illustrated in <FIG>, the endoscope module may also be provided with a heating unit <NUM> in place of the pressurizing unit <NUM>. As the heating unit <NUM>, for example, an infrared heater or the like may be used. The control unit 41a controls the heating unit <NUM> to heat the internal space of the actuator <NUM> to expand the gas, thereby increasing the internal pressure of the actuator <NUM>.

The endoscope module may also be provided with both the pressurizing unit <NUM> and the heating unit <NUM>. In this case, both the pressurizing unit <NUM> and the heating unit <NUM> may be operated at the same time, or the pressurizing unit <NUM> and the heating unit <NUM> may be selectively operated by mode switching.

The endoscope module is not required to be provided with the depressurizing unit <NUM>. In this case, the control unit <NUM> executes only the operation of increasing the internal pressure of the actuator <NUM> in a flowchart illustrated in <FIG>.

Pressure detecting operations at steps S22, S25, and S30 illustrated in <FIG> may be repeatedly performed at predetermined time intervals when the endoscope module is operated.

As illustrated in <FIG>, an endoscope module according to a third embodiment of the present technology is provided with an endoscope <NUM>, a control unit 41b, a bending drive circuit <NUM>, a bending angle detection circuit <NUM>, an internal pressure detection circuit 43b, a pressurizing unit <NUM>, and a depressurizing unit <NUM>. The control unit 41b is connected to a power supply <NUM>. Note that, in the third embodiment, a portion similar to that in the second embodiment is assigned with the same reference sign and the description thereof is omitted.

Electrodes 11b and 11c (refer to <FIG>) provided on an inner peripheral surface and an outer peripheral surface, respectively, of a dielectric layer 11a included in an actuator element <NUM> are deformed by bending or a change in internal pressure of the actuator <NUM>. The internal pressure detection circuit 43b detects the internal pressure of the actuator <NUM> from a change in electrostatic capacitance (change in distance) between the electrodes 11b and 11c opposed to each other with the dielectric layer 11a interposed therebetween and supplies a detection result to the control unit 41b. The bending angle detection circuit <NUM> detects a bending angle of the actuator <NUM> from a change in electric resistance caused by the deformation of the electrodes 11b and 11c and supplies a detection result to the control unit 41b. On the basis of the internal pressure supplied from the internal pressure detection circuit 43b and the bending angle supplied from the bending angle detection circuit <NUM>, the control unit 41b feedback-controls the pressurizing unit <NUM> and the depressurizing unit <NUM> such that the internal pressure of the actuator <NUM> becomes a prescribed pressure.

The endoscope module according to the third embodiment feedback-controls the pressurizing unit <NUM> and the depressurizing unit <NUM> such that the internal pressure of the actuator <NUM> becomes the prescribed pressure on the basis of the internal pressure and the bending angle of the actuator <NUM>. Therefore, it is possible to appropriately control the internal pressure of the actuator <NUM> when operating the actuator <NUM> as compared with the endoscope module according to the second embodiment.

The endoscope module may be provided with a heating unit <NUM> in place of the pressurizing unit <NUM> or may be provided with the heating unit <NUM> together with the pressurizing unit <NUM>. Furthermore, the endoscope module is not required to be provided with the depressurizing unit <NUM>.

An actuator <NUM> according to a fourth embodiment of the present technology is a speaker having a sealed structure and is provided with a cylindrical actuator element <NUM> and a supporting body <NUM> which supports both ends of the actuator element <NUM> as illustrated in <FIG>. An internal pressure of the actuator <NUM> is higher than an external pressure of the actuator <NUM>.

The cylindrical actuator element <NUM> is provided with a cylindrical dielectric layer, a first electrode provided on an inner peripheral surface of the dielectric layer, and a second electrode provided on an outer peripheral surface of the dielectric layer. The first and second electrodes may be provided on the inner peripheral surface and the outer peripheral surface, respectively, of the dielectric layer in a predetermined pattern or provided on entire or substantially entire inner peripheral surface and outer peripheral surface, respectively, of the dielectric layer. The supporting body <NUM> is provided with a shaft portion 52a and disk-shaped supporting units 52b and 52c provided at both ends of the shaft portion 52a.

In the actuator <NUM> according to the fourth embodiment, since the internal pressure of the actuator <NUM> is higher than the external pressure of the actuator <NUM>, an effect similar to that of the actuator <NUM> according to the first embodiment may be obtained.

The actuator element <NUM> may have a rectangular tubular shape such as a square tubular shape and the supporting units 52b and 52c may have a polygonal shape such as a square shape.

The actuator <NUM> in the fourth embodiment, the pressure-sensitive sensor <NUM>, the control unit <NUM>, the internal pressure detection circuit <NUM>, the pressurizing unit <NUM>, and the depressurizing unit <NUM> in the second embodiment may form the actuator module. In this case, the actuator module may be provided with a heating unit <NUM> in place of the pressurizing unit <NUM>, or may be provided with the heating unit <NUM> together with the pressurizing unit <NUM>. Furthermore, the actuator module is not required to be provided with the depressurizing unit <NUM>.

An actuator <NUM> according to a fifth embodiment of the present technology is a speaker having a sealed structure and is provided with a rectangular actuator element <NUM> and a supporting body <NUM> which supports a peripheral edge of the actuator element <NUM> as illustrated in <FIG>. An internal pressure of the actuator <NUM> is higher than an external pressure of the actuator <NUM>.

The rectangular actuator element <NUM> is provided with a rectangular dielectric layer, a first electrode provided on one surface of the dielectric layer, and a second electrode provided on the other surface of the dielectric layer. The first and second electrodes may be provided on both surfaces of the dielectric layer in a predetermined pattern or may be provided on entire or substantially entire both surfaces of the dielectric layer. The supporting body <NUM> supports the actuator element <NUM> in a convexly curved state.

In the actuator <NUM> according to the fifth embodiment, since the internal pressure of the actuator <NUM> is higher than the external pressure of the actuator <NUM>, an effect similar to that of the actuator <NUM> according to the first embodiment may be obtained.

The actuator <NUM> may form the actuator module in a manner similar to that of the variation of the fourth embodiment.

Although the embodiments of the present technology are heretofore described specifically, the present technology is not limited to the above-described embodiments, and various modifications based on the technical idea of the present technology may be made.

For example, the configuration, the method, the step, the shape, the material, the numerical value and the like described in the above-described embodiments are merely examples, and the configuration, the method, the step, the shape, the material, the numerical value and the like different from those may also be used as necessary.

Claim 1:
An actuator module comprising
an actuator (<NUM>, <NUM>) including a tubular actuator element (<NUM>); and
a supporting body which supports an inner peripheral surface of the actuator element (<NUM>),
a control unit (<NUM>) configured to control drive of the actuator (<NUM>, <NUM>); and
a pressurizing unit (<NUM>) configured to pressurize a sealed cylindrical internal space of the actuator (<NUM>, <NUM>);
a detecting unit (<NUM>, <NUM>) configured to detect a pressure in the internal space,
wherein the actuator element (<NUM>) is a dielectric elastomer actuator element;
wherein the actuator element (<NUM>) is provided with a tubular dielectric layer (11a), a first electrode (11b) provided on an inner peripheral surface of the dielectric layer (11a), and a second electrode (11c) provided on an outer peripheral surface of the dielectric layer (11a); and
wherein the control unit (<NUM>) is configured to control the pressurizing unit (<NUM>) according to a detection result of the detecting unit (<NUM>, <NUM>) such that the pressure of the internal space of the actuator element (<NUM>) is higher than an external pressure of the actuator element (<NUM>).