EP2648479B1 - Four à micro-ondes - Google Patents

Four à micro-ondes Download PDF

Info

Publication number
EP2648479B1
EP2648479B1 EP11845252.3A EP11845252A EP2648479B1 EP 2648479 B1 EP2648479 B1 EP 2648479B1 EP 11845252 A EP11845252 A EP 11845252A EP 2648479 B1 EP2648479 B1 EP 2648479B1
Authority
EP
European Patent Office
Prior art keywords
microwave
waveguide
radiating portions
propagation
slits
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
EP11845252.3A
Other languages
German (de)
English (en)
Other versions
EP2648479A1 (fr
EP2648479A4 (fr
Inventor
Daisuke Hosokawa
Koji Yoshino
Hiroshi Fukuda
Masayuki Kubo
Masafumi Sadahira
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Panasonic Corp
Original Assignee
Panasonic Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Panasonic Corp filed Critical Panasonic Corp
Publication of EP2648479A1 publication Critical patent/EP2648479A1/fr
Publication of EP2648479A4 publication Critical patent/EP2648479A4/fr
Application granted granted Critical
Publication of EP2648479B1 publication Critical patent/EP2648479B1/fr
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/70—Feed lines
    • H05B6/704—Feed lines using microwave polarisers
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/70—Feed lines
    • H05B6/707—Feed lines using waveguides
    • H05B6/708—Feed lines using waveguides in particular slotted waveguides
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/64—Heating using microwaves
    • H05B6/80—Apparatus for specific applications
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B2206/00—Aspects relating to heating by electric, magnetic, or electromagnetic fields covered by group H05B6/00
    • H05B2206/04—Heating using microwaves
    • H05B2206/045—Microwave disinfection, sterilization, destruction of waste...

Definitions

  • the present invention relates to microwave heaters such as microwave ovens and, more particularly, relates to microwave heaters including microwave radiating portions with characteristic structures.
  • Microwave ovens are adapted to radiate microwaves generated from a microwave generating portion, within a heating chamber made of a metal, thereby performing heating processes on objects to be heated within the heating chamber, through microwaves radiated therein.
  • magnetrons As microwave generating portions in conventional microwave ovens, magnetrons have been employed. A magnetron creates microwave, and the microwave is radiated within a heating chamber through a waveguide. When there is a non-uniform microwave electromagnetic-field distribution within the heating chamber, it is impossible to perform uniform microwave heating on objects to be heated.
  • ordinary microwave heaters have included structures for rotating tables which place objects to be heated thereon for rotating the objects to be heated, structures for rotating antennas which radiate microwaves while fixing objects to be heated, or structures for causing phase shifts in microwaves generated from microwave generating portions, as means for uniformizing heating of objects to be heated.
  • conventional microwave heater has been provided with a rotational antenna, an antenna shaft and the like within a waveguide and, further, have been adapted to drive a magnetron while rotating the rotational antenna through an antenna motor, in order to alleviate non-uniformity in the microwave distribution within the heating chamber.
  • Patent Literature 1 it has been suggested microwave heater having a rotatable antenna provided to a magnetron.
  • the microwave heater in Patent Literature 1 is adapted to direct cooling air flows from a blower fan to the blades in the rotatable antenna, in order to rotate the antenna by wind power from the blower fan, thereby changing the microwave distribution within the heating chamber.
  • Patent Literature 2 As an example of provision of a phase shifter, there has been a microwave heater described in U.S. Patent No. 4,301,347 (Patent Literature 2), which attains cost reduction and reduction of the space of feeding portions, in addition to alleviation of heating unevenness in objects to be heated during microwave heating. As described in Patent Literature 2, there have been suggested microwave heaters provided with a rotational mechanism for causing phase shifts and with a single microwave radiating portion for radiating circularly-polarized waves within a heating chamber.
  • Microwave heaters such as microwave ovens have been required to perform heating on objects to be heated with simple structures and with higher efficiency, and without inducing heating unevenness.
  • conventional structures which have been suggested in the past as described above have had various problems.
  • microwave heaters particularly microwave ovens
  • commercial products with rated high-frequency outputs of 1000 W have been on sale in Japan.
  • a striking feature of microwave heaters, as commercial products, is convenience of directly heating food through induction heating, rather than heating food through heat conduction.
  • microwave ovens are adapted to generate higher outputs in states where heating unevenness has not overcome, this makes the problem of heating unevenness more obvious.
  • the first point is that there is a need for a mechanism for rotating a table or an antenna for alleviating heating unevenness. Therefore, conventional microwave heaters have been required to secure a rotation space for rotating the table or the antenna, and an installation space for a driving mechanism such as a motor for rotating the table or the antenna, which has obstructed size reduction of microwave heaters.
  • the second point is that, in order to stably rotate the table or the antenna, it is necessary to provide this rotational antenna at an upper portion or a lower portion in the heating chamber, which has imposed restrictions on the structure.
  • microwave heaters adapted to radiate circularly-polarized waves within a heating chamber from a single microwave radiating portion in order to attain cost reduction and reduction of the space of feeding portions in addition to alleviation of heating unevenness in objects to be heated during microwave heating, as described in Patent Literature 2, have the advantage of having no rotational mechanism for a table or an antenna, but have the problem of necessity of a rotational mechanism for causing phase shifts, and the problem of impossibility of realization of sufficiently-uniform heating on objects to be heated through microwave radiation from the single microwave radiating portion.
  • US-4,301,347 B relates to a feed system for a microwave oven.
  • the heating uniformity of a microwave oven is significantly improved by a feed that radiates rotating elliptically polarized electromagnetic waves.
  • a pair of crossed slots in the feed rectangular waveguide has directional characteristics and radiates energy with right-hand and left-hand circular polarization.
  • a variable phase shifter in the waveguide changes the phase of one of the polarizations. Both polarizations interfere in the oven cavity and produce rotating elliptically polarized waves.
  • the circular polarizing element can be a 3-dB hybrid coupler or a turnstile junction.
  • CH 684 373 A relates to a device for injection (input coupling) of microwaves.
  • the device consists of a waveguide which is coupled to a microwave source and has one or more coupling elements using which microwaves can be injected into an application volume.
  • the coupling elements are disposed and arranged so that waves coming from the source generate circular-polarised waves in the application volume. If these waves are reflected in the application volume and coupled back through the coupling elements, they generate in the waveguide waves which propagate away from the microwave source towards an artificial load where they are absorbed.
  • US-4,336,434 B relates to a microwave oven cavity excitation system which introduces circularly-polarized electromagnetic wave energy into a cooking cavity through a plurality of feed points appropriately phased to provide a concentrated beam.
  • the relative phasing of the feed points is varied as a function of time to steer the concentrated beam to sweep the interior of the cavity, improving the time-averaged energy distribution.
  • phase shift element disclosed is a dielectric vane rotated by airflow through a feed waveguide within which the dielectric vane is rotatably mounted.
  • US-5,948,310 B describes a microwave oven for radiating microwaves generated from a magnetron into a cavity to heat and cook foodstuff disposed therein, the microwave oven comprising an antenna disposed between a magnetron and the cavity for converting the microwaves to circularly polarized waves to radiate same into the cavity, the microwave oven having the advantage in that the foodstuff in the cavity is heated by radiation of the circularly polarized waves, thereby enabling a uniform heating of the foodstuff and improving an absorption efficiency of microwave energy.
  • US-3,210,511 relates to ovens for heating articles of food and the like, using microwave electromagnetic radiation as the heating energy.
  • the invention is defined by the subject-matter of independent claim 1.
  • the dependent claims are directed to advantageous embodiments.
  • the present invention overcomes the aforementioned problems in conventional microwave heaters and provides a microwave heater capable of performing uniform and efficient microwave heating on objects to be heated, without using a rotational mechanism.
  • a heating chamber adapted to house an object to be heated; a placement portion which forms a bottom surface of the heating chamber and is adapted to accommodate and place, thereon, the object to be heated within the heating chamber; a microwave generating portion adapted to generate a microwave; a waveguide adapted to propagate the microwave from the microwave generating portion; and a plurality of microwave radiating portions which are provided in a surface of the waveguide which is faced to the heating chamber and are adapted to radiate a circularly-polarized wave within the heating chamber.
  • the microwave heater having the aforementioned structure is enabled to suppress the occurrence of standing waves due to interference of microwaves radiated within the heating chamber with microwaves having been reflected by the inner walls and the like of the heating chamber, which has been regarded as a problem in microwave heating through conventional microwave heaters. This can realize uniform microwave heating.
  • the microwave heater is capable of performing uniform and efficient microwave heating on objects to be heated with a simple structure and without using a rotational mechanism and, also, is capable of having a feeding portion with a reduced size and having improved reliability.
  • a first invention comprises a heating chamber adapted to house an object to be heated; a placement portion which forms a bottom surface of the heating chamber and is adapted to accommodate and place, thereon, the object to be heated within the heating chamber; a microwave generating portion adapted to generate a microwave; a waveguide adapted to propagate the microwave from the microwave generating portion; and a plurality of microwave radiating portions which are provided in a surface of the waveguide which is faced to the heating chamber and are adapted to radiate a circularly-polarized wave within the heating chamber.
  • the microwave heater having the aforementioned structure according to the first invention is enabled to suppress the occurrence of standing waves due to interference of microwaves radiated within the heating chamber with microwaves having been reflected by the inner walls and the like of the heating chamber, which has been regarded as a problem in microwave heating through conventional microwave heaters. This can realize uniform microwave heating.
  • a second invention is configured that the plurality of the microwave radiating portions are placed just under the placement portion.
  • the microwave heater having the structure according to the second invention is enabled to perform uniform microwave heating on the object to be heated.
  • a microwave heater of a third invention is configured that the respective plurality of the microwave radiating portions are adapted to radiate substantially the same amount of microwaves.
  • the microwave heater having the structure according to the third invention is enabled to perform uniform microwave heating on the object to be heated.
  • a fourth invention is configured that, especially in the third invention, the plurality of the microwave radiating portions are placed, in such a way as to be arranged at least in a direction of propagation in the waveguide.
  • the microwave heater having the structure according to the fourth invention is enabled to perform uniform and efficient microwave heating on the object to be heated, since the microwave radiating portions are properly placed at desired positions.
  • a fifth invention is configured that, especially in the third invention, the plurality of the microwave radiating portions are placed, in such a way as to be arranged at least in a direction orthogonal to a direction of an electric field and to a direction of propagation in the waveguide.
  • the microwave heater having the structure according to the fifth invention is enabled to perform uniform and efficient microwave heating on the object to be heated.
  • a sixth invention is configured that, especially in the fourth or the fifth invention, the plurality of the microwave radiating portions comprise two slits intersected with each other, and each slit is shaped to have a longer side inclined with respect to the direction of propagation in the waveguide.
  • the microwave heater having the structure according to the sixth invention is enabled to perform uniform and efficient microwave heating on the object to be heated.
  • a seventh invention is configured that, especially in the fourth or the fifth invention, the plurality of the microwave radiating portions comprise two slits intersected with each other, each slit is shaped to have a longer side inclined with respect to the direction of propagation in the waveguide, and the longer sides of the slits have lengths which are varied depending on their positions in the direction of propagation in the waveguide.
  • the microwave heater having the structure according to the seventh invention is enabled to control the amount of microwave radiations and, thus, is enabled to perform uniform and efficient microwave heating on the object to be heated, by varying the respective lengths of the slits in the microwave radiating portions, as well as through the placement of the microwave radiating portions.
  • An eighth invention is configured that, especially in the fourth or the fifth invention, the plurality of the microwave radiating portions comprise two slits intersected with each other, each slit is shaped to have a longer side inclined with respect to the direction of propagation in the waveguide, and the longer sides of the slits have lengths which are varied depending on their positions in a direction orthogonal to the direction of the electric field and to the direction of propagation in the waveguide.
  • the microwave heater having the structure according to the eighth invention is enabled to perform uniform and efficient microwave heating on the object to be heated.
  • a ninth invention is configured that, especially in the fourth or the fifth invention, the plurality of the microwave radiating portions comprise two slits intersected with each other, each slit is shaped to have a longer side inclined with respect to the direction of propagation in the waveguide, and the slits have widths which are varied depending on their positions in the direction of propagation in the waveguide.
  • the microwave heater having the structure according to the ninth invention is enabled to change the microwave distribution within the heating chamber, thereby ensuring uniformity of the microwave distribution within the heating chamber, by varying the widths of the slits in the microwave radiating portions, as well as through the placement of the microwave radiating portions.
  • a tenth invention is configured that, especially in the fourth or the fifth invention, the plurality of the microwave radiating portions comprise two slits intersected with each other, each slit is shaped to have a longer side inclined with respect to the direction of propagation in the waveguide, and the slits have widths which are varied depending on their positions in a direction orthogonal to the direction of the electric field and to the direction of propagation in the waveguide.
  • the microwave heater having the structure according to the tenth invention is enabled to perform uniform and efficient microwave heating on the object to be heated.
  • An eleventh invention is configured that, especially in the fourth or the fifth invention, the plurality of the microwave radiating portions comprise two slits intersected with each other, each slit is shaped to have a longer side inclined with respect to the direction of propagation in the waveguide, and the slits have been subjected to round chamfering (R) or chamfering (C) at their intersection portions.
  • the microwave heater having the structure according to the eleventh invention is enabled to reduce microwave losses in the microwave radiating portions and, thus, is enabled to perform efficient microwave heating on the object to be heated.
  • a twelfth invention is configured that, especially in the fourth or the fifth invention, the plurality of the microwave radiating portions comprise two slits intersected with each other, each slit is shaped to have a longer side inclined with respect to the direction of propagation in the waveguide, and the slits have been subjected to round chamfering (R) or chamfering (C) at their distal end portions.
  • the microwave heater having the structure according to the twelfth invention is enabled to reduce microwave losses in the microwave radiating portions and, thus, is enabled to perform efficient microwave heating on the object to be heated.
  • a thirteenth invention is configured that, especially in the fourth or the fifth invention, the plurality of the microwave radiating portions comprise two slits intersected with each other, each slit is shaped to have a longer side inclined with respect to the direction of propagation in the waveguide, and in terms of the positions of the intersection portions of the slits, a microwave radiating portion at a larger propagation distance from the position at which the microwave generating portion is installed is shaped to have a higher rate of radiation of a microwave to the heating chamber through the waveguide, than that of a microwave radiating portion at a smaller propagation distance from the position at which the microwave generating portion is installed.
  • the microwave heater having the structure according to the thirteenth invention is enabled to perform uniform and efficient microwave heating on the object to be heated.
  • a fourteenth invention is configured that, especially in the third invention, the placement portion adapted to accommodate and place, thereon, the object to be heated within the heating chamber includes a microwave transmission portion which is penetrated by microwaves, the microwave transmission portion is placed oppositely to the microwave radiating portions, and the microwave transmission portion is provided at least just above the microwave radiating portions.
  • the microwave heater having the structure according to the fourteenth invention, the placement portion can be formed to have a smaller area which is penetrated by microwaves.
  • the microwave heater is enabled to reduce the amount of microwave energy losses caused by absorption of microwaves in the placement portion, which can increase the efficiency of heating of the object to be heated through microwaves, thereby realizing excellent energy saving performance.
  • this microwave heater is of a type for radiating circularly-polarized microwaves within the heating chamber, which eliminates the necessity of providing a rotational antenna, and a motor for driving the rotational antenna. This can eliminate the necessity of providing a driving space and an installation space for such mechanisms, which can attain size reduction of the microwave heater, thereby making the installation space smaller.
  • a fifteenth invention is configured that, especially in the fourteenth invention, the microwave transmission portion has a shape conforming to the microwave radiating portions.
  • the microwave heater having the structure according to the fifteenth invention is enabled to have a minimum necessary area which is penetrated by microwaves, which further reduces microwave absorption losses in the microwave transmission portion. As a result thereof, the microwave heater is enabled to have an increased efficiency of supply of microwaves to the heating chamber.
  • a sixteenth invention is configured that, especially in the fifteenth invention, the placement portion includes the microwave transmission portion, and a microwave reflection portion for reflecting microwaves.
  • the microwave reflection portion is structured to reflect microwaves which have not been absorbed by the object to be heated, which facilitates absorption of microwaves by the object to be heated, thereby further increasing the efficiency of heating through microwaves.
  • a seventeenth invention is configured that, especially in the sixteenth invention, the microwave transmission portion is made of a crystallized glass containing at least one material, out of silicon oxide, aluminum oxide, zirconium oxide, and lithium oxide.
  • the microwave heater having the structure according to the seventeenth invention, it is possible to improve the microwave transmission performance, which can increase microwave energy radiated within the heating chamber, thereby increasing the efficiency of heating of the object to be heated through microwaves.
  • An eighteenth invention is configured that, especially in the sixteenth invention, the microwave transmission portion is mainly made of a plastic material.
  • the microwave heater having the structure according to the eighteenth invention it is possible to improve the microwave transmission performance in comparison with cases of using a crystallized glass, which can increase the efficiency of heating the object to be heated.
  • a nineteenth invention is configured that, especially in the sixteenth invention, the microwave reflection portion is made of a metal material.
  • the microwave heater having the structure according to the nineteenth invention it is possible to improve the microwave reflection performance, which can increase the efficiency of heating the object to be heated through microwaves.
  • microwave heaters according to the present invention will be described with respect to microwave ovens, but these microwave ovens are merely illustrative, and the microwave heater according to the present invention is not limited to such microwave ovens and is intended to include microwave heaters which utilize induction heating. Further, the present invention is not limited to the concrete structures according to the following embodiments and is intended to cover structures based on technical concepts similar thereto.
  • Fig. 1 is a perspective view illustrating a microwave oven as a microwave heater according to a first embodiment of the present invention.
  • Fig. 2 is a cross-sectional view of the microwave heater according to the first embodiment of the present invention, taken along a plane parallel with the front surface thereof, at a substantially-middle position in the depthwise direction, illustrating main structural portions therein.
  • Fig. 3 is a top view of a waveguide as a waveguide portion, illustrating the positions of microwave radiation portions which are antennas for radiating circularly-polarized microwaves, in the microwave heater according to the first embodiment of the present invention.
  • the microwave oven as the microwave heater 1 includes a door 7 having a window in its front surface, a heating chamber 2 which is enclosed by the door 7 being closed and is adapted to house, therein, an object to be heated through microwave heating, and a placement portion 3 for housing and placing, thereon, the object to be heated, within the heating chamber 2.
  • microwave radiating portions 6 are provided as microwave radiating means for radiating microwaves within the heating chamber 2.
  • Each of the microwave radiating portions 6 is adapted to radiate circularly-polarized waves within the heating chamber 2.
  • the microwave heater 1 includes a microwave generating device 4 as a microwave generating portion which is constituted by a magnetron and the like for generating microwaves, and the waveguide 5 as the waveguide portion for propagating microwaves generated from the microwave generating device 4, to the respective microwave radiating portions 6.
  • the microwave heater 1 in the microwave heater 1 according to the first embodiment, there are formed, on the upper surface of the waveguide 5, the plurality of the microwave radiating portions 6 which are adapted to radiate substantially the same amount of circularly-polarized microwaves within the heating chamber 2.
  • the microwave radiating portions 6 are placed such that the object to be heated on the placement portion 3 is uniformly and efficiently heated by microwaves.
  • microwave heater provided with only a single microwave radiating portion with higher directivity is enabled to intensively heat only the vicinity of the microwave radiating portion. This results in the problem of occurrences of heating unevenness in objects to be heated.
  • the plurality of the microwave radiating portions 6 are provided in the waveguide 5 as the waveguide portion in its surface faced to the heating chamber 2, and the respective microwave radiating portions 6 are adapted to radiate substantially the same amount of circularly-polarized microwaves within the heating chamber 2. Therefore, even in cases where microwaves from the respective microwave radiating portions 6 have higher directivity, it is possible to realize uniform microwave heating for the object to be heated.
  • the microwave radiating portions 6 are adapted to radiate circularly-polarized microwaves.
  • Conventional ordinary microwave heaters have been structured to radiate linearly-polarized microwaves (having electric fields with constant polarization planes) from microwave radiating portions within heating chambers, which has induced standing waves due to interference of microwaves radiated within the heating chambers with microwaves having been reflected by the inner walls and the like of the heating chambers, thereby causing heating unevenness in objects to be heated.
  • the microwave heater 1 according to the first embodiment can suppress the occurrence of standing waves due to the interference of radiated microwaves with microwaves having been reflected by the inner walls and the like of the heating chamber, which has been regarded as a problem in microwave heating through conventional microwave heaters. This can realize uniform microwave heating.
  • Circular polarization is a technique which has been widely utilized in the fields of mobile communications and satellite communications. Examples of familiar usages thereof include ETCs (Electronic-Toll Collection Systems) "Non-Stop Automated Fee Collection Systems”.
  • a circularly-polarized wave is a microwave having an electric field with a polarization plane which is rotated, with time, with respect to the direction of propagation of radio waves.
  • the direction of its electric field continuously changes with time.
  • the microwaves radiated within the heating chamber continuously change in terms of the direction of their electric fields, so that they have an electric field intensity with a magnitude which is substantially uniform regardless of the positions, thereby providing the property of suppressing the occurrence of standing waves, even in consideration of reflections at the inner walls and the like of the heating chamber.
  • the microwave heater 1 according to the first embodiment is provided with the plurality of the microwave radiating portions 6 and, further, is adapted to cause the respective microwave radiating portions 6 to radiate circularly-polarized microwaves within the heating chamber 2.
  • the microwave heater 1 having this structure according to the first embodiment is enabled to perform microwave heating more uniformly on the object to be heated within the heating chamber 2, since microwaves are radiated more uniformly within the heating chamber 2, than in cases of microwave heating with linearly-polarized microwaves, which have been utilized in conventional ordinary microwave heaters.
  • Circularly-polarized waves are sorted into two types, which are right-handed polarized waves (CW : clockwise) and left-handed polarized waves (CCW : counter to clockwise), based on the direction of rotations thereof.
  • the heating performance is not varied, depending on whether the circularly-polarized waves radiated within the heating chamber 2 are right-handed polarized waves (CW : clockwise) or left-handed polarized waves (CCW : counter to clockwise).
  • the waveguide adapted to propagate microwaves from the microwave generating device constituted by a magnetron or the like there are linearly-polarized microwaves with electric fields and magnetic fields which are oscillating in constant directions.
  • conventional ordinary microwave heaters have been adapted to radiate linearly-polarized microwaves through waveguides within heating chambers.
  • a mechanism for rotating a table for placing an object to be heated thereon a mechanism for rotating an antenna for radiating microwaves through a waveguide within the heating chamber, or a phase shifter for causing a phase shift inside the waveguide.
  • the microwave heater 1 according to the first embodiment is structured to overcome all of them.
  • the microwave heater 1 according to the first embodiment is structured to have the plurality of the microwave radiating portions 6 provided on the surface of the waveguide 5 which is faced to the heating chamber 2 and to cause the respective microwave radiating portions 6 to radiate substantially the same amount of circularly-polarized microwaves within the heating chamber 2. Therefore, the microwave heater 1 according to the first embodiment forms a device which is capable of performing uniform and efficient microwave heating on objects to be heated, while having a simple and reliable structure and imposing less restrictions on its structure.
  • the microwave heater 1 according to the first embodiment is capable of realizing uniform microwave heating for objects to be heated within the heating chamber 2, without being provided with a mechanism for rotating a table or an antenna or being provided with a phase shifter. Accordingly, the microwave heater 1 according to the first embodiment is capable of certainly avoiding the problem of heating unevenness and the like in objects to be heated during heating operations, which are induced in the event of failures of the rotating mechanism and in the event of abnormal operations.
  • the amounts of microwaves radiated within the heating chamber 2 from the respective microwave radiating portions 6 are varied by the following three conditions.
  • the first condition is the distance (the position) in the direction X of propagation (see Fig. 2 ) to the microwave radiating portions 6 from the microwave generating device 4 constituted by a magnetron and the like.
  • the amount of microwaves is varied depending on the distance (the position) in the direction X of propagation, for the following reason.
  • microwaves generated from the microwave generating device 4 are in un-stabilized propagation states.
  • at positions at larger propagation distances from the microwave generating device 4 they are in stabilized states.
  • the microwave radiating portions 6 placed in the periphery of the bent portion are made to radiate larger amounts of microwaves than those from the microwave radiating portions 6 at sufficient distances from the periphery of the bent portion, wherein the amount of microwaves radiated therefrom is largely increased or decreased with varying position in the direction X of propagation.
  • the second condition is the distance in the direction X of propagation to the microwave radiating portions 6 from a termination end surface 15 which is a termination end of the waveguide 5 in Fig. 2 .
  • Microwaves propagating within the waveguide 5 are linearly-polarized waves. Therefore, due to the interference of them with waves having been reflected by the termination end surface 15 of the waveguide 5, there are induced standing waves within the waveguide 5.
  • the electric field is zero at the termination end surface of the waveguide 5 and, thus, the electric field intensity varies with the distance from the termination end surface 15 in the direction X of propagation. Therefore, the amount of microwaves radiated within the heating chamber 2 is increased and decreased with the distance in the direction X of propagation to the microwave radiating portions 6 from the termination end surface 15 of the waveguide 5.
  • the electric field intensity is maximized, at the position at a distance equal to 1/4 the wavelength of standing waves, in the direction X of propagation, from the termination end surface 15 of the waveguide 5. Further, the electric field intensity is minimized, at the position at a distance equal to 1/2 the wavelength of standing waves, in the direction X of propagation, from the termination end surface 15 of the waveguide 5.
  • the microwave radiating portions 6 have the same shape, if they are at different distances from the termination end surface 15 of the waveguide 5 in the direction X of propagation, the respective microwave radiating portions 6 are caused to radiate increased or decreased amounts of microwaves.
  • the third condition is the position in the direction (the widthwise direction Z of the waveguide 5: see Fig. 3 ) which is orthogonal to the direction X of propagation and to the direction Y of the electric field (see Fig. 2 ), in the waveguide 5. This is due to the fact that the electric field intensity is varied in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field, in the waveguide 5 through which microwaves are propagating.
  • microwave heaters such as microwave ovens are adapted to propagate microwaves in the TE10 mode. Therefore, there exists an electric-field-distribution symmetry axis which extends in the direction X of propagation, such that it passes through the center of the waveguide in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field.
  • the microwave radiating portions adjacent to each other in the direction X of propagation are made to be equal to the wavelength of standing waves induced within the waveguide, the microwave radiating portions adjacent to each other are caused to radiate microwaves with the same electric field intensity.
  • the respective microwave radiating portions are caused to radiate microwaves with different electric field intensities corresponding to the length differences.
  • the microwave radiating portions 6 are placed on the surface of the waveguide 5 which is faced to the heating chamber 2, in such a way as to uniformize the microwave distribution within the heating chamber. Accordingly, even when the microwave radiating portions 6 are placed at symmetric positions with respect to the center of the internal space in the heating chamber 2, if the microwave radiating portions 6 are placed without taking account of the aforementioned three conditions, the microwave distribution within the heating chamber 2 can not be uniformized, in many cases.
  • the technique for properly placing the plurality of the microwave radiating portions 6 at desired positions for uniformizing the microwave distribution within the internal space in the heating chamber 2 is necessary.
  • the structures of the microwave radiating portions 6 for radiating circularly-polarized waves in the microwave heater according to the first embodiment.
  • the structures of the microwave radiating portions 6 can be any structures capable of radiating circularly-polarized waves and are not particularly limited. Examples of their concrete shapes will be described, with reference to Fig. 4.
  • Fig. 4 illustrates concrete shapes of the microwave radiating portions 6 for use in the microwave heater according to the first embodiment.
  • the microwave radiating portions 6 illustrated in Fig. 4 are constituted by at least two or more slits (elongated opening portions).
  • each of the microwave radiating portions 6 is constituted by two or more slits (elongated opening portions). Only at least a single slit, out of them, is required to have a shape with a longer side inclined with respect to the direction X of propagation of microwaves.
  • the shapes of the microwave radiating portions 6 can be any shapes capable of creating circularly-polarized waves and, also, can be shapes formed by slits which are not intersected with each other as illustrated in (e) and (f) in Figs. 4 , or shapes formed by integrated three slits as illustrated in (d) in Fig. 4 .
  • the microwave radiating portion 6 for radiating circularly-polarized waves which is constituted by the two slits (the elongated opening portions) illustrated in (a) in Fig. 4 , for example, in the microwave heater according to the first embodiment.
  • each slit should have a longer side with a length equal to or more than about 1/4 the in-tube wavelength ⁇ g within the waveguide 5.
  • the second point is that the two slits should be orthogonal to each other and, also, each slit should have a longer side inclined by an angle of 45 degrees with respect to the direction X of propagation.
  • the third point is as follows. That is, the electric field distribution should not be formed symmetrically with respect to an axis which is coincident to a straight line which is parallel with the direction X of propagation in the waveguide 5 and, also, passes through a substantially-center portion of the microwave radiating portion 6.
  • the slits (the elongated opening portions) can be intersected with each other such that they are inclined rather than being made orthogonal to each other.
  • the microwave radiating portion 6 can radiate circularly-polarized waves, which enables bringing the center position at which the slits intersect with each other closer to an end portion of the waveguide 5 in the widthwise direction, without narrowing the slit opening portions for radiating circularly-polarized waves.
  • each of the two or more slits can be placed in such a way as to be spaced apart from the others.
  • the slits can be also inclined by only an angle of about 30 degrees, rather than being orthogonal to each other.
  • the shapes of the slits in the microwave radiating portion 6 are not limited to rectangular shapes.
  • the opening portions in the slits can be also formed to have curved surfaces (R) or cut surfaces (C) at their corners. By shaping them as described above, it is possible to generate circularly-polarized waves and, also, it is possible to alleviate concentrations of electric fields, thereby enabling microwave heating with higher efficiency.
  • microwave heater according to a second embodiment of the present invention is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 5 is a perspective view illustrating a microwave oven as a microwave heater according to the second embodiment of the present invention.
  • Fig. 6 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves, in the microwave heater according to the second embodiment of the present invention.
  • the microwave oven as the microwave heater 1 according to the second embodiment includes a heating chamber 2 adapted to house an object to be heated therein, and a placement portion 3 for housing and placing, thereon, the object to be heated. Further, just under the placement portion 3, there are placed a plurality of microwave radiating portions 6 for radiating circularly-polarized microwaves within the heating chamber 2, such that they are arranged at least in the direction X of propagation, on the upper surface of the waveguide 5.
  • the microwave heater 1 in the microwave heater 1 according to the second embodiment, there are provided the plurality of the microwave radiating portions 6 adapted to radiate substantially the same amount of circularly-polarized waves within the heating chamber 2, as microwave radiating means, on the upper surface (the surface faced to the heating chamber 2) of the waveguide 5, such that they are arranged in the direction X of propagation. Due to this placement of the microwave radiating portions 6, it is possible to realize uniform and efficient microwave heating for objects to be heated within the heating chamber 2.
  • the microwave heater according to the second embodiment it is necessary only that a plurality of microwave radiating portions 6 be placed such that they are arranged at least in the direction X of propagation.
  • the structure according to the second embodiment also covers structures having a plurality of microwave radiating portions 6 which are placed in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field, as well as in the direction X of propagation.
  • the upper-limit size and the lower-limit size of the waveguide 5 in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field are restricted by the frequency of microwaves generated from the employed microwave generating device 4 and by the size of the waveguide 5 in the direction Y of the electric field (see Fig. 5 ).
  • the TE10 mode with H waves (TE waves ; Transverse Electric Waves) is used as a propagation mode, wherein the TE10 mode is a propagation mode having only magnetic-field components while having no electric-field component in the direction of the tube axis of the waveguide. Further, other propagation modes than the TE10 mode are hardly employed in waveguides in microwave heaters.
  • a rectangular waveguide 301 as a representative waveguide which is mounted in a microwave oven.
  • a simplest ordinary waveguide is a rectangular-parallelepiped member having a constant rectangular-shaped cross section (width a x height b) which is extended in the direction X of propagation, as illustrated in Fig. 7 .
  • the width a of the waveguide 301 is selected within the range of ( ⁇ >a> ⁇ /2)
  • the height b of the waveguide 301 is selected within the range of (b ⁇ /2).
  • the TE10 mode refers to a propagation mode with H waves (TE waves ; Transverse Electric Waves) having only magnetic-field components while having no electric-field component in the direction X of propagation in the rectangular waveguide 301, within the rectangular waveguide 301. Further, other propagation modes than the TE10 mode are hardly employed in the waveguide 5 in the microwave heater 1 according to the first embodiment.
  • H waves TE waves ; Transverse Electric Waves
  • microwaves In microwave ovens, microwaves have wavelengths ⁇ of about 120 mm.
  • the width a of the waveguide is selected within the range of about 80 to 100 mm, and the height b thereof is selected within the range of about 15 to 40 mm, in many cases.
  • H planes 302 which mean planes in which magnetic fields are eddied in parallel
  • E planes 303 which mean planes parallel to the electric field.
  • the in-tube wavelength ⁇ g is varied depending on the size of the width a, but is unrelated to the size of the height b.
  • the microwave generating device 4 constituted by a magnetron and the like is coupled to the waveguide 5 at the center thereof in the widthwise direction (Z), at which the electric field is maximized.
  • the microwave heater according to the third embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement and the concrete structure of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 8 is a perspective view illustrating the microwave heater according to the third embodiment of the present invention.
  • Fig. 9 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves, in the microwave heater according to the third embodiment.
  • the microwave oven as the microwave heater 1 according to the third embodiment includes a heating chamber 2 adapted to house an object to be heated therein, and a placement portion 3 for housing and placing, thereon, the object to be heated. Further, just under the placement portion 3, there are placed a plurality of microwave radiating portions 6 adapted to radiate substantially the same amount of circularly-polarized microwaves within the heating chamber 2, such that they are arranged at least in the direction X of propagation, on the upper surface of the waveguide 5.
  • the microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are constituted by two slits (elongated opening portions) intersected with each other in an X shape, wherein each slit has a longer side inclined (by an angle of 45 degrees) with respect to the direction X of propagation in the waveguide 5.
  • the plurality of the microwave radiating portions 6 with the X shape for radiating circularly-polarized waves are placed such that they are arranged in the direction X of propagation. Due to this placement of the plurality of the microwave radiating portions 6, it is possible to realize uniform and efficient microwave heating for objects to be heated within the heating chamber 2.
  • Fig. 9 there is illustrated an example where at least two microwave radiating portions 6 with an X shape are provided at positions deviated from a line vertically above the tube axis P of the waveguide 5, with a predetermined interval L interposed therebetween, such that they are arranged in the direction X of propagation in the waveguide 5.
  • the line connecting the respective points at which the slits intersect with each other in the plurality of the X-shaped microwave radiating portions 6 to each other is coincident to the direction X of propagation in the waveguide 5.
  • the microwave heater according to the third embodiment it is necessary only that a plurality of microwave radiating portions 6 be placed such that they are arranged at least in the direction X of propagation.
  • the present invention also covers cases where a plurality of microwave radiating portions 6 are placed in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field, as well as in the direction X of propagation.
  • the microwave heater according to the third embodiment similarly, as described in the aforementioned second embodiment, in cases of propagating microwaves generated from a microwave generating device 4 as a microwave generating portion constituted by a magnetron and the like, using the waveguide 5, the upper-limit size and the lower-limit size of the waveguide 5 in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field are restricted by the frequency of microwaves generated from the employed magnetron and by the size of the waveguide 5 in the direction Y of the electric field.
  • the slits (the elongated opening portions) illustrated in Fig. 9 should have a length (2p) which is equal to or more than about 1/4 the in-tube wavelength ⁇ g of microwaves being propagated within the waveguide 5, the two slits should intersect with each other at their centers in the lengthwise directions, and each of the slits should be inclined by an angle of 45 degrees with respect to the direction X of propagation.
  • the microwave radiating portions 6 constituted by the two slits intersected with each other are structured such that an axis which is parallel to the direction X of propagation and, further, passes through the intersection portions of the slits in the microwave radiating portions 6 is not at a position about which the electric-field distribution within the waveguide 5 is symmetric.
  • the electric-field distribution within the waveguide 5 is symmetric about an axis which is coincident with the tube axis P which extends in the direction X of propagation and, further, passes through the center of the waveguide 5 in the direction Z orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5. Therefore, in the structure according to the third embodiment, the intersection portions of the slits in the microwave radiating portions 6 are placed at positions deviated from a line vertically above the symmetry axis in the waveguide 5, namely the tube axis P of the waveguide 5. By placing the slits in the microwave radiating portions 6 as described above, the microwave radiating portions 6 are enabled to certainly radiate circularly-polarized waves.
  • the microwave radiating portions 6 for radiating circularly-polarized waves as the intervals between the microwave radiating portions 6 adjacent to each other are decreased, the concentrations of electric fields between the microwave radiating portions 6 are increased, which increases microwave losses, thereby degrading the heating efficiency. It is preferable that the microwave radiating portions 6 adjacent to each other are placed with intervals of 5 mm or more interposed therebetween. Therefore, in the structure according to the third embodiment, the microwave radiating portions 6 adjacent to each other are placed in such a way as to provide largest possible intervals interposed therebetween, in the widthwise direction Z in the waveguide 5.
  • the microwave heater 1 having the aforementioned structure according to the third embodiment is capable of realizing uniform microwave heating for objects to be heated within the heating chamber 2, without being provided with a mechanism for rotating a table or an antenna or being provided with a phase shifter. Accordingly, the microwave heater 1 according to the third embodiment is capable of preventing the problem of heating unevenness and the like in objects to be heated during heating operations, which are induced in the event of failures of the rotating mechanism and in the event of abnormal operations.
  • the amounts of microwaves radiated within the heating chamber 2 from the microwave radiating portions 6 are increased or decreased, according to three conditions, as described in the aforementioned first embodiment.
  • the first condition is the distance in the direction X of propagation from the microwave generating device 4 to the microwave radiating portions 6.
  • the second condition is the distance in the direction X of propagation from the termination end surface 15 of the waveguide 5 to the microwave radiating portions 6.
  • the third condition is the position in the direction (the widthwise direction Z of the waveguide 5) orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5 (see Fig. 2 ).
  • the microwave radiating portions 6 are not placed in such a way as to uniformize the microwave distribution within the heating chamber 2, in consideration of the aforementioned conditions, even when the microwave radiating portions 6 are placed symmetrically with respect to the center of the heating chamber 2, the microwave distribution within the heating chamber 2 may not be uniformized, in many cases.
  • the technique for varying the microwave distribution within the heating chamber 2 is necessary.
  • the microwave heater according to the fourth embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement and the concrete structure of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 10 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves, in the microwave heater according to the fourth embodiment of the present invention.
  • a plurality of microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are placed on the upper surface (the surface faced to the heating chamber 2) of the waveguide 5, such that they are arranged at least in the direction X of propagation.
  • the microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are constituted by two slits (elongated opening portions) intersected with each other in an X shape, wherein each slit has a longer side inclined (by an angle of 45 degrees) with respect to the direction X of propagation the waveguide 5.
  • the lengths 2p of the slits in the microwave radiating portions 6 are varied depending on their positions in the direction X of propagation in the waveguide 5.
  • Fig. 10 there is illustrated an example where, among two microwave radiating portions 6, the microwave radiating portion 6 (the microwave radiating portion in the right side in Fig.
  • the microwave heater according to the fourth embodiment is structured to perform uniform and efficient microwave heating on objects to be heated within the heating chamber 2.
  • the microwave heater 1 it is necessary only that a plurality of microwave radiating portions 6 be placed such that they are arranged at least in the direction X of propagation.
  • the structure according to the fourth embodiment also covers cases where a plurality of microwave radiating portions 6 are placed in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field, as well as in the direction X of propagation.
  • the plurality of the microwave radiating portions 6 are not always placed symmetrically with respect to the center of the heating chamber 2, due to the relationship thereof with other designed components. Further, even when the plurality of the microwave radiating portions 6 are placed symmetrically with respect to the center of the heating chamber 2, a non-uniform microwave distribution may be formed within the heating chamber 2, in many cases, since various types of members such as heaters, a door glass are mounted inside the chamber of the microwave heater 1 such as a microwave oven.
  • the microwave heater 1 according to the fourth embodiment is adapted to ensure a uniform microwave distribution within the heating chamber 2, by varying the lengths 2p of the slits in the microwave radiating portions 6, in addition to the placements of the plurality of the microwave radiating portions 6.
  • the microwave radiating portion 6 In general, in a microwave radiating portion 6 having two slits intersected with each other, if the length 2p of the slits is decreased to make the opening area of the microwave radiating portions 6 smaller, the microwave radiating portion 6 is caused to radiate a decreased amount of microwaves within the heating chamber 2.
  • the length 2p of the slits in the microwave radiating portion 6 in the right side can be made smaller for making the opening area in the microwave radiating portion 6 in the right side smaller, which can reduce the amount of microwaves radiated within the heating chamber 2 from the microwave radiating portion 6 in the right side, thereby causing the respective microwave radiating portions 6 to radiate substantially the same amount of microwaves. This can ensure uniformity of the microwave distribution within the heating chamber 2.
  • the plurality of the microwave radiating portions 6 are each constituted by two slits intersected with each other, each slit is shaped to have a longer side inclined with respect to the direction X of propagation in the waveguide 5, and the lengths 2p of the longer sides of the slits are varied depending on their positions in the direction of propagation in the waveguide 5.
  • the microwave heater having the aforementioned structure according to the fourth embodiment is enabled to control the amount of radiation of microwaves and, thus, is enabled to perform microwave heating uniformly and efficiently on the objects to be heated, by varying the respective lengths 2p of the slits in the microwave radiating portions 6, as well as the placements of the microwave radiating portions 6.
  • the microwave radiating portions 6 should have different structures, according to specifications, structures and the like of respective microwave heaters. Therefore, by varying the shapes of the slits in the microwave radiating portions 6, which are to be provided in the waveguide 5 according to respective microwave heaters, it is possible to ensure uniformity of the microwave distribution within the heating chamber 2.
  • the upper-limit size and the lower-limit size of the waveguide 5 in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field are restricted by the frequency of microwaves generated from the employed magnetron and by the size of the waveguide 5 in the direction Y of the electric field.
  • the slits (the elongated opening portions) illustrated in Fig. 10 should have lengths 2p which are equal to or more than about 1/4 the in-tube wavelength ⁇ g of microwaves being propagated within the waveguide 5, the two slits should intersect with each other at their centers in the lengthwise directions, and each of the slits should be inclined by an angle of 45 degrees with respect to the direction X of propagation.
  • an axis which is parallel to the direction X of propagation and, further, passes through the intersection portions of the slits in the microwave radiating portions 6 is not at a position about which the electric-field distribution within the waveguide 5 is symmetric.
  • the electric-field distribution within the waveguide 5 is symmetric about an axis which is coincident with the tube axis P which extends in the direction X of propagation and, further, passes through the center of the waveguide 5 in the direction Z orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5. Therefore, in the structure according to the fourth embodiment, the intersection portions of the slits in the microwave radiating portions 6 are placed at positions deviated from a line vertically above the symmetry axis in the waveguide 5, namely the tube axis P of the waveguide 5. By placing the slits of the microwave radiating portions 6 as described above, the microwave radiating portions 6 are enabled to certainly radiate circularly-polarized waves.
  • the microwave radiating portions 6 for radiating circularly-polarized waves as the intervals between the microwave radiating portions 6 adjacent to each other are decreased, the concentrations of electric fields between the microwave radiating portions 6 are increased, which increases microwave losses, thereby degrading the heating efficiency. It is preferable that the microwave radiating portions 6 adjacent to each other are placed with intervals of 5 mm or more interposed therebetween. Therefore, in the structure according to the fourth embodiment, the microwave radiating portions 6 adjacent to each other are placed in such a way as to provide largest possible intervals interposed therebetween, in the widthwise direction Z in the waveguide 5.
  • the amounts of microwaves radiated within the heating chamber 2 from the microwave radiating portions 6 are increased or decreased, according to three conditions, as described in the aforementioned first embodiment.
  • the first condition is the distance in the direction X of propagation from the microwave generating device 4 to the microwave radiating portions 6.
  • the second condition is the distance in the direction X of propagation from the termination end surface 15 of the waveguide 5 to the microwave radiating portions 6.
  • the third condition is the position in the direction (the widthwise direction Z of the waveguide 5) orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5 (see Fig. 2 ).
  • microwave radiating portions 6 are not placed in such a way as to uniformize the microwave distribution within the heating chamber 2, in consideration of the aforementioned conditions, even when the microwave radiating portions are placed symmetrically with respect to the center of the heating chamber 2, the microwave distribution within the heating chamber 2 may not be uniformized, in many cases.
  • the technique for varying the microwave distribution within the heating chamber 2 is necessary.
  • the microwave heater according to the fifth embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement and the concrete structure of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 11 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves, in the microwave heater according to the fifth embodiment of the present invention.
  • a plurality of microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are placed on the upper surface (the surface faced to the heating chamber 2) of the waveguide 5 such that they are arranged at least in the direction X of propagation.
  • the microwave radiating portions 6 for radiating circularly-polarized waves (left-handed polarized waves or right-handed polarized waves) within the heating chamber 2 are constituted by two slits (elongated opening portions) intersected with each other in an X shape, wherein each slit has a longer side inclined (by an angle of 45 degrees) with respect to the direction X of propagation in the waveguide 5.
  • the widths 2q of the slits in the microwave radiating portions 6 are varied depending on their positions in the direction X of propagation in the waveguide 5.
  • Fig. 11 there is illustrated an example where, among two microwave radiating portions 6, the microwave radiating portion 6 (the microwave radiating portion in the right side in Fig. 11 ) closer to the microwave generating portion 4 constituted by a magnetron is formed to have an opening portion which is smaller than the opening portion of the microwave radiating portion 6 (the microwave radiating portion in the left side in Fig. 11 ) farther from the microwave generating portion 4, thereby suppressing the amount of microwaves radiated therefrom.
  • the microwave heater according having the aforementioned structure according to the fifth embodiment is enabled to control the amount of radiation of microwaves, by varying the relationship among the placements of the plurality of the microwave radiating portions 6, and the widths (the opening areas) of the slits in the respective microwave radiating portions 6. Accordingly, the microwave heater according to the fifth embodiment is structured to perform uniform and efficient microwave heating on objects to be heated within the heating chamber 2.
  • the microwave heater according to the fifth embodiment it is necessary only that a plurality of microwave radiating portions 6 be placed such that they are arranged at least in the direction X of propagation.
  • the structure according to the fifth embodiment also covers structures having a plurality of microwave radiating portions 6 which are placed in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field, as well as in the direction X of propagation.
  • the plurality of the microwave radiating portions 6 are not always placed symmetrically with respect to the center of the heating chamber 2, due to the relationship thereof with other designed components. Further, even when the plurality of the microwave radiating portions 6 are placed symmetrically with respect to the center of the heating chamber 2, the microwave distribution within the heating chamber 2 may be made non-uniform, since various types of members such as heaters, a door glass are mounted inside the chamber of the microwave heater 1 such as a microwave oven.
  • the microwave heater 1 according to the fifth embodiment is adapted to ensure a uniform microwave distribution within the heating chamber 2, by varying the widths 2q of the slits in the microwave radiating portions 6, in addition to the placements of the plurality of the microwave radiating portions 6.
  • the microwave radiating portion 6 In general, in a microwave radiating portion 6 having two slits intersected with each other, if the width 2q of the slits is decreased to make the opening area of the microwave radiating portions 6 smaller, the microwave radiating portion 6 is caused to radiate a decreased amount of microwaves within the heating chamber 2.
  • the width 2q of the slits in the microwave radiating portion 6 in a left-side area can be made larger for making the opening area in the microwave radiating portion 6 in the left-side area larger.
  • the microwave radiating portion 6 in the left-side area is caused to radiate an increased amount of microwaves within the heating chamber 2, which can ensure uniformity of the microwave distribution within the heating chamber 2.
  • the upper-limit size and the lower-limit size of the waveguide 5 in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field are restricted by the frequency of microwaves generated from the employed magnetron and by the size of the waveguide 5 in the direction Y of the electric field.
  • the slits (the elongated opening portions) illustrated in Fig. 11 should have lengths (2p) which are equal to or more than about 1/4 the in-tube wavelength ⁇ g of microwaves being propagated within the waveguide 5, the two slits should intersect with each other at their centers in the lengthwise directions, and each of the slits should be inclined by an angle of 45 degrees with respect to the direction X of propagation.
  • an axis which is parallel to the direction X of propagation and, further, passes through the intersection portions of the slits in the microwave radiating portions 6 is not at a position about which the electric-field distribution within the waveguide 5 is symmetric.
  • the electric-field distribution within the waveguide 5 is symmetric about an axis which is coincident with the tube axis P which extends in the direction X of propagation and, further, passes through the center of the waveguide 5 in the widthwise direction Z. Therefore, in the structure according to the fifth embodiment, the intersection portions of the slits in the microwave radiating portions 6 are placed at positions deviated from a line vertically above the symmetry axis in the waveguide 5, namely the tube axis P of the waveguide 5. By placing the slits of the microwave radiating portions 6 as described above, the microwave radiating portions 6 are enabled to certainly radiate circularly-polarized waves.
  • the microwave radiating portions 6 for radiating circularly-polarized waves as the intervals between the microwave radiating portions 6 adjacent to each other are decreased, the concentrations of electric fields between the microwave radiating portions 6 are increased, which increases microwave losses, thereby degrading the heating efficiency. It is preferable that the microwave radiating portions 6 adjacent to each other are placed with intervals of 5 mm or more interposed therebetween. Therefore, in the structure according to the fifth embodiment, the microwave radiating portions 6 adjacent to each other are placed in such a way as to provide largest possible intervals interposed therebetween, in the widthwise direction Z in the waveguide 5.
  • the amounts of microwaves radiated within the heating chamber 2 from the microwave radiating portions 6 are increased or decreased, according to three conditions, as described in the aforementioned first embodiment.
  • the first condition is the distance in the direction X of propagation from the microwave generating device 4 to the microwave radiating portions 6.
  • the second condition is the distance in the direction X of propagation from the termination end surface 15 of the waveguide 5 to the microwave radiating portions 6.
  • the third condition is the position in the direction (the widthwise direction Z of the waveguide 5) orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5 (see Fig. 2 ).
  • microwave radiating portions 6 are not placed in such a way as to uniformize the microwave distribution within the heating chamber 2, in consideration of the aforementioned conditions, even when the microwave radiating portions are placed symmetrically with respect to the center of the heating chamber 2, the microwave distribution within the heating chamber 2 may not be uniformized, in many cases.
  • the technique for varying the microwave distribution within the heating chamber 2 is necessary.
  • the plurality of the microwave radiating portions 6 are each constituted by two slits intersected with each other, each slit is shaped to have a longer side inclined with respect to the direction X of propagation in the waveguide 5, and the widths 2q of the slits are varied depending on their positions in the direction of propagation X in the waveguide 5.
  • the microwave heater having the aforementioned structure according to the fifth embodiment is enabled to change the microwave distribution within the heating chamber 2 and, thus, is enabled to ensure uniformity of the microwave distribution within the heating chamber 2, by varying the widths 2q of the slits in the microwave radiating portions 6, as well as the placements of the microwave radiating portions 6.
  • the microwave heater according to the sixth embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement and the concrete structure of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 12 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves, in the microwave heater according to the sixth embodiment of the present invention.
  • a plurality of microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are placed on the upper surface (the surface faced to the heating chamber 2) of the waveguide 5 such that they are arranged at least in the direction X of propagation.
  • the microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are constituted by two slits (elongated opening portions) intersected with each other in an X shape, wherein each slit has a longer side inclined (by an angle of 45 degrees) with respect to the direction X of propagation in the waveguide 5.
  • the microwave radiating portions 6 are shaped such that their intersection portions 12 (see Fig. 12 ) have been subjected to round chamfering (R) or chamfering (C) at their corners.
  • microwave heater 1 having the aforementioned structure according to the sixth embodiment, it is possible to reduce microwave losses in the microwave radiating portions 6, which enables performing microwave heating on objects to be heated, with higher efficiency.
  • Microwaves have the property of being concentrated at corners, and portions with sharp tip ends. Therefore, if the microwave radiating portions 6 constituted by the two slits intersected with each other are made to have sharp shapes at their intersection portions, this induces concentrations of electric fields of microwaves, thereby inducing the problem of reduction of the heating efficiency.
  • the microwave radiating portions 6 constituted by the two slits intersected with each other have been subjected to round chamfering (R) or chamfering (C) at the corner portions in their intersection portions 12, which alleviates concentrations of electric fields, thereby increasing the heating efficiency.
  • the microwave heater according to the seventh embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement and the concrete structure of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 13 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves, in the microwave heater according to the seventh embodiment of the present invention.
  • a plurality of microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are placed on the upper surface (the surface faced to the heating chamber 2) of the waveguide 5 such that they are arranged at least in the direction X of propagation.
  • the microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are constituted by two slits (elongated opening portions) intersected with each other in an X shape, wherein each slit has a longer side inclined (by an angle of 45 degrees) with respect to the direction X of propagation in the waveguide 5.
  • the microwave radiating portions 6 are shaped such that the distal end portions 13 of the respective slits have been subjected to round chamfering (R) or chamfering (C).
  • microwave heater 1 having the aforementioned structure according to the seventh embodiment, it is possible to reduce microwave losses in the microwave radiating portions 6, which enables performing microwave heating on objects to be heated, with higher efficiency.
  • Microwaves have the property of being concentrated at corners, and portions with sharp tip ends. Therefore, if the microwave radiating portions constituted by the two slits intersected with each other are made to have sharp shapes at the distal end portions 13 of the slits, this induces concentrations of electric fields of microwaves, thereby inducing the problem of reduction of the heating efficiency.
  • the microwave radiating portions 6 constituted by the two slits intersected with each other have been subjected to round chamfering (R) or chamfering (C) at the distal end portions 13 of the slits, which alleviates concentrations of electric fields, thereby increasing the heating efficiency.
  • Fig. 14 is a view illustrating a concrete structure of a microwave radiating portion 6 according to the aforementioned sixth and seventh embodiments, illustrating an example of a microwave radiating portion 6 constituted by two slits (elongated opening portions) intersected with each other in an X shape.
  • Fig. 14 there is illustrated an example where the intersection portion 12 of the slits in the microwave radiating portion 6 has been subjected to round chamfering (R) or chamfering (C), while the distal end portions 13 of the slits have been subjected to round chamfering (R) or chamfering (C).
  • R round chamfering
  • C chamfering
  • the microwave heater according to the eighth embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement and the concrete structure of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 15 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves, in the microwave heater according to the eighth embodiment of the present invention.
  • the microwave heater 1 includes a plurality of microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2, at least in the direction X of propagation.
  • the microwave radiating portions 6 are constituted by two slits intersected with each other, wherein each slit is shaped to have a longer side inclined with respect to the direction X of propagation in the waveguide 5.
  • the microwave radiating portion 6 (the microwave radiating portion at the center in Fig. 15 ) at a larger propagation distance from the position at which the microwave generating device 4 as the microwave generating portion is installed is structured to have a higher rate of radiation of microwaves to the heating chamber 2 through the waveguide 5, than that of the microwave radiating portion 6 (the microwave radiating portion at the right end in Fig.
  • the microwave radiating portions 6 at larger propagation distances from the position at which the microwave generating device 4 is installed can be structured to have higher rates of radiation of microwaves to the heating chamber 2 through the waveguide 5, than those of the microwave radiating portions 6 at smaller propagation distances from the position at which the microwave generating device 4 is installed.
  • the respective microwave radiating portions 6 are caused to radiate substantially the same amount of microwaves, which enables uniform microwave heating on the object to be heated within the heating chamber 2, thereby enabling efficient microwave heating on the object to be heated.
  • the term "the rate of radiation” refers to the ratio of the amount of microwaves radiated from each microwave radiating portion 6 to the amount of microwaves being propagated through the waveguide 5.
  • the microwave heater 1 it is necessary only that a plurality of microwave radiating portions 6 be placed such that they are arranged at least in the direction X of propagation.
  • the structure according to the eighth embodiment also covers cases where a plurality of microwave radiating portions 6 are placed in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field, as well as in the direction X of propagation.
  • the plurality of the microwave radiating portions 6 are not always placed symmetrically with respect to the center of the heating chamber 2, due to the relationship thereof with other designed components. Further, even when the plurality of the microwave radiating portions 6 are placed symmetrically with respect to the center of the heating chamber 2, the microwave distribution within the heating chamber 2 may be made non-uniform, since various types of members such as heaters, a door glass are mounted inside the chamber of the microwave heater 1 such as a microwave oven.
  • microwave radiating portions 6 in the direction X of propagation, even when the respective microwave radiating portions 6 have the same rate of radiation of microwaves to the heating chamber 2 through the waveguide 5, the microwave radiating portions 6 at smaller propagation distances from the position at which the microwave generating device 4 is installed are caused to radiate larger amounts of microwaves.
  • microwave radiating portions 6 are caused to radiate microwaves within the heating chamber 2, in ascending order of their propagation distances from the position at which the microwave generating device 4 is installed and, in the direction X of propagation in the waveguide 5, the amount of microwaves being propagated therethrough is gradually decreased.
  • the microwave heater according to the eighth embodiment is enabled to certainly ensure uniformity of the microwave distribution within the heating chamber 2, by making the respective microwave radiating portions 6 have different rates of radiation of microwaves to the heating chamber 2 through the waveguide 5, as well as through the placements of the plurality of the microwave radiating portions 6.
  • the microwave radiating portions 6 are constituted by two slits (elongated opening portions) intersected with each other, wherein each slit is shaped to have a longer side inclined with respect to the direction X of propagation in the waveguide 5.
  • the microwave radiating portions 6 having this structure are made to have different radiation rates, there is an example where the lengths (2p) of the slits or the widths (2q) of the slits are varied to increase or decrease their opening areas for radiating microwaves.
  • microwave radiating portions 6 arranged in series in two rows in the direction X of propagation and, further, there are provided microwave radiating portions 6 arranged in series, in three rows, in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field, namely there are provided, in total, six microwave radiating portions 6.
  • Microwaves are propagated through the rectangular waveguide 5 provided with the six microwave radiating portions 6 as described above.
  • the following equation (1) is an equation for determining the coupling factor Cu of a cruciform directional coupler. Based on the equation (1) for determining the coupling factor Cu of a cruciform directional coupler, there will be described a method for determining the shapes of microwave radiating portions 6.
  • the coupling factor Cu of the cruciform directional coupler means the rate of radiation of microwaves from each microwave radiating portion 6 to the heating chamber 2 through the waveguide 5.
  • Cu ⁇ 20 log 10 2 ⁇ M / a 2 b ⁇ 1 / 1 ⁇ f 2 / fr 2 ⁇ sin 2 ⁇ X 0 / a ⁇ sin 4 ⁇ X 0 / ⁇ g + 27.3 1 ⁇ 4 p / ⁇ 2 ⁇ t / 2 p dB
  • the respective microwave radiating portions 6 should be caused to radiate the same amount of microwaves within the heating chamber 2, and traveling waves generated from the microwave generating device 4 should be all radiated within the heating chamber 2, namely there should be induced no reflected wave at the termination end surface 15 of the waveguide 5.
  • each of the microwave radiating portions 6 is required to radiate microwaves in an amount of about 16.7 % of the amount of microwaves generated from the microwave generating device 4.
  • the microwave heater according to the eighth embodiment of the present invention there will be described, as an example, a case where the aforementioned respective parameters are determined as follows, and only the lengths of the slits in the respective microwave radiating portions 6 are varied, in order to adjust the rates of radiations from the respective microwave radiating portions 6.
  • the respective parameters in the equation (1) are determined as follows, for example, and the length of the slits is determined.
  • the microwave radiating portions 6 at the same propagation distance from the position at which the microwave generating device 4 is installed are required to have the same rate of radiation of microwaves within the heating chamber 2.
  • each of the microwave radiating portions 6 is caused to radiate, within the heating chamber 2, microwaves in an amount of about 16.7 % of the amount of microwaves generated from the microwave generating device 4.
  • the equation (1) regarding a cruciform directional coupler is an equation for cases where there are two microwave radiating portions.
  • the respective microwave radiating portions 6 should have slit lengths 2p of 53.6 mm, 55.0 mm, and 57.0 mm, in ascending order to their propagation distances from the position at which the microwave generating device 4 is installed.
  • microwave heater according to the eighth embodiment of the present invention has been described with respect to a case where the number of microwave radiating portions 6 is six, the present invention is not limited to the case of six microwave radiating portions and can be also applied to cases where there are a plurality of microwave radiating portions 6 in the direction X of propagation.
  • the microwave heater according to the eighth embodiment has been described with respect to a case where the respective microwave radiating portions 6 are varied in terms of only the slit lengths 2p, for adjusting the radiation rates of the respective microwave radiating portions 6, the present invention is not limited to this structure.
  • the present invention also covers structures adapted to vary other parameters, such as the longer-side (A) size of the aforementioned rectangular waveguide 301 (see Fig. 7 ), the shorter-side (B) size of the rectangular waveguide, the length of 1/2 the slit width, for adjusting the radiation rates of the respective microwave radiating portions 6.
  • the respective microwave radiating portions 6 radiate non-uniform amounts of microwaves within the heating chamber 2, such as in cases where there are a plurality of microwave radiating portions 6 in the direction X of propagation, and the microwave radiating portions 6 are desired to radiate gradually-increased amounts of microwaves in descending order of their propagation distances from the position at which the microwave generating device 4 is installed, it is possible to adjust these parameters for adjusting them.
  • the parameters are varied for adjusting them, in consideration of such reflected waves, in such a way as to uniformize the amounts of radiations of microwaves within the heating chamber 2 from the respective microwave radiating portions 6.
  • the microwave heater according to the ninth embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 17 is a perspective view illustrating a microwave oven as the microwave heater according to the ninth embodiment of the present invention.
  • Fig. 18 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves (left-handed polarized waves or right-handed polarized waves), in the microwave heater according to the ninth embodiment of the present invention.
  • the microwave oven as the microwave heater 1 according to the ninth embodiment includes a door 7 having a window in its front surface, a heating chamber 2 adapted to house an object to be heated therein, and a placement portion 3 made of a non-metal material for housing and placing, thereon, the object to be heated.
  • microwave radiating means for radiating microwaves within the heating chamber 2.
  • microwave radiating means there are provided a plurality of microwave radiating portions 6 for radiating circularly-polarized waves (left-handed polarized waves or right-handed polarized waves) within the heating chamber 2, such that they are arranged in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field.
  • the microwave heater 1 in the microwave heater 1 according to the ninth embodiment, there are provided the plurality of the microwave radiating portions 6 for radiating circularly-polarized waves (left-handed polarized waves or right-handed polarized waves) within the heating chamber 2, in the direction (the widthwise direction Z) orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5, which enables performing uniform and efficient microwave heating on the object to be heated within the heating chamber 2.
  • the microwave heater according to the ninth embodiment it is necessary only that a plurality of microwave radiating portions 6 be placed such that they are arranged at least in the direction Z orthogonal to the direction X of propagation and to the direction Y of the electric field.
  • the structure according to the ninth embodiment also covers structures having a plurality of microwave radiating portions 6 which are placed in the direction X of propagation, as well as in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field.
  • the microwave heater according to the tenth embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement and the concrete structure of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 19 is a perspective view illustrating a microwave heater according to the tenth embodiment of the present invention.
  • Fig. 20 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves (left-handed polarized waves or right-handed polarized waves), in the microwave heater according to the tenth embodiment of the present invention.
  • the microwave oven as the microwave heater 1 includes a door 7 having a window in its front surface, a heating chamber 2 adapted to house an object to be heated therein, and a placement portion 3 made of a non-metal material for housing and placing, thereon, the object to be heated.
  • microwave radiating portions 6 for radiating microwaves as circularly-polarized waves (left-handed polarized waves or right-handed polarized waves) within the heating chamber 2.
  • the microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are constituted by two slits (elongated opening portions) intersected with each other in an X shape, wherein each slit has a longer side inclined (by an angle of 45 degrees) with respect to the direction X of propagation in the waveguide 5.
  • the microwave heater 1 in the microwave heater 1 according to the tenth embodiment, there are provided the plurality of the microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2, such that they are arranged at least in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field.
  • the plurality of the microwave radiating portions 6 By placing the plurality of the microwave radiating portions 6 as described above, it is possible to realize uniform and efficient microwave heating on the object to be heated within the heating chamber 2.
  • At least two microwave radiating portions 6 with an X shape are placed at symmetric positions in the opposite sides with respect to a line vertically above the tube axis P of the waveguide 5, with a predetermined interval interposed therebetween.
  • the two microwave radiating portions 6 are provided such that they are arranged in the widthwise direction Z of the waveguide 5.
  • the line connecting the points of the intersections of the slits in the two microwave radiating portions 6 with the X shape is coincident with the widthwise direction Z of the waveguide 5.
  • the microwave heater according to the tenth embodiment it is necessary only that a plurality of microwave radiating portions 6 be placed such that they are arranged at least in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field.
  • the present invention also covers cases where there are placed a plurality of microwave radiating portions 6 in the direction X of propagation, as well as in the widthwise direction Z.
  • the microwave heater according to the tenth embodiment similarly, as described with respect to the aforementioned second embodiment, in cases of propagating microwaves generated from the microwave generating device 4 constituted by a magnetron and the like, using the waveguide 5, the upper-limit size and the lower-limit size of the waveguide 5 in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field are restricted by the frequency of microwaves generated from the employed magnetron and by the size of the waveguide 5 in the direction Y of the electric field.
  • the slits (the elongated opening portions) illustrated in Fig. 20 should have lengths (2p) which are equal to or more than about 1/4 the in-tube wavelength ⁇ g of microwaves being propagated within the waveguide 5, the two slits should intersect with each other at their centers in the lengthwise directions, and each of the slits should be inclined by an angle of 45 degrees with respect to the direction X of propagation.
  • an axis which is parallel to the direction X of propagation and, further, passes through the intersection portions of the slits in the microwave radiating portions 6 is not at a position (on the tube axis) about which the electric-field distribution within the waveguide 5 is symmetric.
  • the tube axis P which extends in the direction X of propagation such that it passes through the center of the waveguide 5 in the direction (the widthwise direction Z) orthogonal to the direction Y of the electric field and to the direction X of propagation within the waveguide 5. Therefore, the intersection portions of the slits should be provided at positions deviated from the position of the center of the waveguide 5 in the widthwise direction Z.
  • the electric-field distribution within the waveguide 5 is symmetric about an axis which is coincident with the tube axis P which extends in the direction X of propagation and, further, passes through the center of the waveguide 5 in the direction Z orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5. Therefore, in the structure according to the tenth embodiment, the intersection portions of the slits in the microwave radiating portions 6 are placed at positions deviated from a line vertically above the symmetry axis in the waveguide 5, namely the tube axis P of the waveguide 5. By placing the microwave radiating portions 6 as described above, the microwave radiating portions 6 are enabled to certainly radiate circularly-polarized waves (left-handed polarized waves or right-handed polarized waves).
  • the microwave radiating portions 6 adjacent to each other are placed with intervals of 5 mm or more interposed therebetween. Therefore, in the structure according to the tenth embodiment, the microwave radiating portions 6 adjacent to each other are placed in such a way as to provide largest possible intervals interposed therebetween, in the widthwise direction Z in the waveguide 5.
  • the microwave heater 1 having the aforementioned structure according to the tenth embodiment is enabled to realize uniform microwave heating for objects to be heated within the heating chamber 2, without being provided with a mechanism for rotating a table or an antenna or being provided with a phase shifter. Accordingly, the microwave heater 1 according to the tenth embodiment is capable of certainly avoiding the problem of heating unevenness and the like in objects to be heated during heating operations, which are induced in the event of failures of the rotating mechanism and in the event of abnormal operations.
  • the microwave heater according to the eleventh embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement and the concrete structure of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 21 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves (left-handed polarized waves or right-handed polarized waves), in the microwave heater according to the eleventh embodiment of the present invention.
  • a plurality of microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are placed on the upper surface (the surface faced to the heating chamber 2) of the waveguide 5 such that they are arranged at least in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field.
  • the microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are constituted by two slits intersected with each other in an X shape, wherein each slit has a longer side inclined (by an angle of 45 degrees) with respect to the direction X of propagation in the waveguide 5.
  • the lengths 2p of the slits in the microwave radiating portions 6 are varied depending on their positions in the direction (the widthwise direction Z) orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5.
  • the microwave heater 1 having the aforementioned structure according to the eleventh embodiment is enabled to control the amount of radiation of microwaves, by varying the relationship among the placements of the plurality of the microwave radiating portions 6, and the lengths 2p (the opening areas) of the slits in the respective microwave radiating portions 6. Accordingly, the microwave heater according to the eleventh embodiment is enabled to perform uniform and efficient microwave heating on objects to be heated within the heating chamber 2.
  • the microwave heater 1 it is necessary only that a plurality of microwave radiating portions 6 be placed such that they are arranged at least in the widthwise direction Z of the waveguide 5.
  • the structure according to the eleventh embodiment also covers structures having a plurality of microwave radiating portions 6 which are placed in the direction X of propagation, as well as in the widthwise direction Z.
  • the plurality of the microwave radiating portions 6 are not always placed symmetrically with respect to the center of the heating chamber 2, due to the relationship thereof with other designed components. Further, even when the plurality of the microwave radiating portions 6 are placed symmetrically with respect to the center of the heating chamber 2, the microwave distribution within the heating chamber 2 may be made non-uniform, since various types of members such as heaters, a door glass are mounted inside the chamber of the microwave heater 1 such as a microwave oven.
  • the microwave heater according to the eleventh embodiment is adapted to ensure a uniform microwave distribution within the heating chamber 2, by varying the lengths 2p of the slits in the microwave radiating portions 6, in addition to the placements of the plurality of the microwave radiating portions 6.
  • the microwave radiating portion 6 In general, in a microwave radiating portion 6 having two slits intersected with each other, if the length 2p of the slits is decreased to make the opening area of the microwave radiating portions 6 smaller, the microwave radiating portion 6 is caused to radiate a decreased amount of microwaves within the heating chamber 2.
  • the microwave radiating portion 6 in the rear-surface-side area is caused to radiate a decreased amount of microwaves within the heating chamber 2, which can ensure uniformity of the microwave distribution within the heating chamber 2.
  • the plurality of the microwave radiating portions 6 are each constituted by two slits intersected with each other, each slit is shaped to have a longer side inclined with respect to the direction X of propagation in the waveguide 5, and the lengths 2p of the longer sides of the slits are varied depending on their positions in the direction Z orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5.
  • the microwave heater having the aforementioned structure according to the eleventh embodiment is enabled to perform microwave heating uniformly and efficiently on the objects to be heated.
  • the upper-limit size and the lower-limit size of the waveguide 5 in the direction (the widthwise direction Z) orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5 are restricted by the frequency of microwaves generated from the employed magnetron and by the size of the waveguide 5 in the direction Y of the electric field.
  • the slits (the elongated opening portions) illustrated in Fig. 21 should have lengths (2p) which are equal to or more than about 1/4 the in-tube wavelength ⁇ g of microwaves being propagated within the waveguide 5, the two slits should intersect with each other at their centers in the lengthwise directions, and each of the slits should be inclined by an angle of 45 degrees with respect to the direction X of propagation.
  • the microwave radiating portions 6 constituted by the two slits intersected with each other are structured such that an axis which is parallel to the direction X of propagation and, further, passes through the intersection portions of the slits in the microwave radiating portions 6 is not at a position about which the electric-field distribution within the waveguide 5 is symmetric.
  • the electric-field distribution within the waveguide 5 is symmetric about an axis which is coincident with the tube axis P which extends in the direction X of propagation and, further, passes through the center of the waveguide 5 in the direction Z orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5. Therefore, in the structure according to the eleventh embodiment, the intersection portions of the slits in the microwave radiating portions 6 are placed at positions deviated from a line vertically above the symmetry axis in the waveguide 5, namely the tube axis P of the waveguide 5. By placing the slits in the microwave radiating portions 6 as described above, the microwave radiating portions 6 are enabled to certainly radiate circularly-polarized waves (left-handed polarized waves or right-handed polarized waves).
  • the microwave radiating portions 6 for radiating circularly-polarized waves as the intervals between the microwave radiating portions 6 adjacent to each other are decreased, the concentrations of electric fields between the microwave radiating portions 6 are increased, which increases microwave losses, thereby degrading the heating efficiency. It is preferable that the microwave radiating portions 6 adjacent to each other are placed with intervals of 5 mm or more interposed therebetween. Therefore, in the structure according to the eleventh embodiment, the microwave radiating portions 6 adjacent to each other are placed in such a way as to provide largest possible intervals interposed therebetween, in the widthwise direction Z in the waveguide 5.
  • the microwave heater according to the twelfth embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement and the concrete structure of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 22 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves (left-handed polarized waves or right-handed polarized waves), in the microwave heater according to the twelfth embodiment of the present invention.
  • a plurality of microwave radiating portions 6 for radiating circularly-polarized waves (left-handed polarized waves or right-handed polarized waves) within the heating chamber 2 are placed, such that they are arranged at least in the direction Z orthogonal to the direction X of propagation and to the direction Y of the electric field.
  • the microwave radiating portions 6 for radiating circularly-polarized waves (left-handed polarized waves or right-handed polarized waves) within the heating chamber 2 are constituted by two slits intersected with each other in an X shape, wherein each slit has a longer side inclined (by an angle of 45 degrees) with respect to the direction X of propagation in the waveguide 5.
  • the widths 2q of the slits in the microwave radiating portions 6 are varied depending on their positions in the direction Z orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5.
  • the microwave radiating portion 6 in a rear-surface-side area (an area in a right side when viewed in the direction of propagation : in an upper side in Fig. 22 ) is formed to have an opening portion larger than the opening area of the microwave radiating portion 6 in a front-surface-side area (in an area in a left side viewed in the direction of propagation : in a lower side in Fig. 22 ). Therefore, in Fig. 22 , there is illustrated an example where the microwave radiating portion 6 in the rear-surface side area (the area in the right side when viewed in the direction of transmission) is caused to radiate, from its opening portion, an increased amount of microwaves.
  • the microwave heater having the aforementioned structure according to the twelfth embodiment is enabled to control the amount of microwaves radiated therefrom, through the relationship between the placements of the microwave radiating portions 6, and by varying the widths (the opening areas) of the slits in the respective microwave radiating portions 6. Accordingly, the microwave heater according to the twelfth embodiment is enabled to perform microwave heating on the object to be heated within the heating chamber 2, uniformly and efficiently.
  • the microwave heater according to the twelfth embodiment it is necessary only that a plurality of microwave radiating portions 6 be placed such that they are arranged at least in the direction Z.
  • the structure according to the twelfth embodiment also covers structures having a plurality of microwave radiating portions 6 placed in the direction X of propagation, as well as in the widthwise direction Z.
  • the plurality of the microwave radiating portions 6 are not always placed symmetrically with respect to the center of the heating chamber 2, due to the relationship thereof with other designed components. Further, even when the plurality of the microwave radiating portions 6 are placed symmetrically with respect to the center of the heating chamber 2, the microwave distribution within the heating chamber 2 may be made non-uniform, since various types of members such as heaters, a door glass are mounted inside the chamber of the microwave heater 1 such as a microwave oven.
  • the microwave heater according to the twelfth embodiment is enabled to ensure a uniform microwave distribution within the heating chamber 2, by varying the widths 2q of the slits in the microwave radiating portions 6, as well as through the placements of the plurality of the microwave radiating portions 6.
  • the microwave radiating portion 6 In general, in a microwave radiating portion 6 having two slits intersected with each other, if the width 2q of the slits is decreased to make the opening area of the microwave radiating portions 6 smaller, the microwave radiating portion 6 is caused to radiate a decreased amount of microwaves within the heating chamber 2.
  • the slit width 2q in the microwave radiating portion 6 constituted by the two slits intersected with each other in the rear-surface-side area (the upper side in Fig. 22 ) is made larger, in order to make the microwave radiating portion 6 in the rear-surface-side area have a larger opening area.
  • the microwave radiating portion 6 in the rear-surface-side area is caused to radiate an increased amount of microwaves within the heating chamber 2, which can ensure uniformity of the microwave distribution within the heating chamber 2.
  • the upper-limit size and the lower-limit size of the waveguide 5 in the widthwise direction Z are restricted by the frequency of microwaves generated from the employed magnetron and by the size of the waveguide 5 in the direction Y of the electric field.
  • the slits (the elongated opening portions) illustrated in Fig. 22 should have lengths (2p) which are equal to or more than about 1/4 the in-tube wavelength ⁇ g of microwaves being propagated within the waveguide 5, the two slits should intersect with each other at their centers in the lengthwise directions, and each of the slits should be inclined by an angle of 45 degrees with respect to the direction X of propagation.
  • the microwave radiating portions 6 constituted by the two slits intersected with each other are structured such that an axis which is parallel to the direction X of propagation and, further, passes through the intersection portions of the slits in the microwave radiating portions 6 is not at a position about which the electric-field distribution within the waveguide 5 is symmetric.
  • the electric-field distribution within the waveguide 5 is symmetric about an axis which is coincident with the tube axis P which extends in the direction X of propagation and, further, passes through the center of the waveguide 5 in the widthwise direction Z. Therefore, in the structure according to the twelfth embodiment, the intersection portions of the slits in the microwave radiating portions 6 are placed at positions deviated from a line vertically above the symmetry axis in the waveguide 5, namely the tube axis P of the waveguide 5. By placing the slits in the microwave radiating portions 6 as described above, the microwave radiating portions 6 are enabled to certainly radiate circularly-polarized waves.
  • the microwave radiating portions 6 adjacent to each other are placed with intervals of 5 mm or more interposed therebetween. Therefore, in the structure according to the twelfth embodiment, the microwave radiating portions 6 adjacent to each other are placed in such a way as to provide largest possible intervals interposed therebetween, in the widthwise direction Z in the waveguide 5.
  • the plurality of the microwave radiating portions 6 are each constituted by two slits intersected with each other, wherein each slit is shaped to have a longer side inclined with respect to the direction X of propagation in the waveguide 5, and the slit widths 2q are varied depending on their positions in the direction Z orthogonal to the direction Y of the electric field and to the direction X of propagation in the waveguide 5.
  • the microwave heater having the aforementioned structure according to the twelfth embodiment is enabled to perform microwave heating uniformly and efficiently on the objects to be heated.
  • the microwave heater according to the thirteenth embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement and the concrete structure of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 23 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves (left-handed polarized waves or right-handed polarized waves), in the microwave heater according to the thirteenth embodiment of the present invention.
  • a plurality of microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are placed on the upper surface (the surface faced to the heating chamber 2) of the waveguide 5 such that they are arranged at least in the direction Z orthogonal to the direction X of propagation and to the direction Y of the electric field.
  • the microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are constituted by two slits intersected with each other in an X shape, wherein each slit has a longer side inclined (by an angle of 45 degrees) with respect to the direction X of propagation in the waveguide 5.
  • the microwave radiating portions 6 are shaped such that the intersection portions 12 have been subjected to round chamfering (R) or chamfering (C) at their corners.
  • FIG. 14 illustrates an example of the round chamfering (R) or chamfering (C) applied to the corners of the intersection portions 12 of the slits in the microwave radiating portions 6.
  • R round chamfering
  • C chamfering
  • microwave heater 1 having the aforementioned structure according to the thirteenth embodiment, it is possible to reduce microwave losses in the microwave radiating portions 6, which enables performing microwave heating on objects to be heated, with higher efficiency.
  • Microwaves have the property of being concentrated at corners, and portions with sharp tip ends. Therefore, if the microwave radiating portions 6 constituted by the two slits intersected with each other are made to have sharp shapes at their intersection portions, this induces concentrations of electric fields of microwaves, thereby inducing the problem of reduction of the heating efficiency.
  • the microwave radiating portions 6 constituted by the two slits intersected with each other have been subjected to round chamfering (R) or chamfering (C) at the corners of the intersection portions 12, which alleviates concentrations of electric fields, thereby increasing the heating efficiency.
  • the microwave heater according to the fourteenth embodiment is different from the microwave heater according to the aforementioned first embodiment, in terms of the placement and the concrete structure of microwave radiating portions, but the other structures are the same as those of the microwave heater according to the first embodiment.
  • Fig. 24 is a top view of a waveguide 5, illustrating microwave radiation portions 6 for radiating circularly-polarized microwaves (left-handed polarized waves or right-handed polarized waves), in the microwave heater according to the fourteenth embodiment of the present invention.
  • a plurality of microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are placed on the upper surface (the surface faced to the heating chamber 2) of the waveguide 5 such that they are arranged at least in the direction (the widthwise direction Z) orthogonal to the direction X of propagation and to the direction Y of the electric field.
  • the microwave radiating portions 6 for radiating circularly-polarized waves within the heating chamber 2 are constituted by two slits intersected with each other in an X shape, wherein each slit has a longer side inclined (by an angle of 45 degrees) with respect to the direction X of propagation in the waveguide 5.
  • the microwave radiating portions 6 have been subjected to round chamfering (R) or chamfering (C) at their slit distal end portions 13.
  • the aforementioned Fig. 14 illustrates an example of the round chamfering (R) or chamfering (C) applied to the slit distal end portions 13 in the microwave radiating portions 6.
  • Fig. 14 there is illustrated an example where both round chamfering (R) and chamfering (C) have been applied thereto, it is necessary only that at least one of both the processes be applied to the slit distal end portions 13 in the microwave radiating portions 6.
  • microwave heater 1 having the aforementioned structure according to the fourteenth embodiment, it is possible to reduce microwave losses in the microwave radiating portions 6, which enables performing microwave heating on objects to be heated, with higher efficiency.
  • Microwaves have the property of being concentrated at corners, and portions with sharp tip ends. Therefore, if the microwave radiating portions 6 constituted by the two slits intersected with each other are made to have angular shapes at their slit distal end portions 13, this induces concentrations of electric fields of microwaves, thereby inducing the problem of reduction of the heating efficiency.
  • the microwave radiating portions constituted by the two slits intersected with each other have been subjected to round chamfering (R) or chamfering (C) at the slit distal end portions 13, which alleviates concentrations of electric fields, thereby increasing the heating efficiency.
  • the microwave heaters according to the aforementioned first to fourteenth embodiments have been described as being structured to have a plurality of microwave radiating portions 6 for radiating circularly-polarized waves which are placed at desired positions in the surface of the waveguide 5 which is faced to the heating chamber 2 in order to perform microwave heating uniformly and efficiently on objects to be heated within the heating chamber 2.
  • microwave heaters according to the fifteenth and sixteenth embodiments will be described, with respect to structures provided with an opening-sealing means which will be described later, as the placement portion in the microwave heaters according to the aforementioned first to fourteenth embodiments, which enables microwave heating with increased efficiency.
  • microwave heaters which are adapted to propagate microwaves generated therein to a rotational antenna and, further, to radiate the microwaves within a heating chamber while stirring the microwaves through the rotational antenna.
  • Fig. 30 illustrates a conventional microwave heater described in Unexamined Japanese Patent Publication No. 2007-225186 (Patent Literature 3).
  • the conventional microwave heater illustrated in Fig. 30 includes a heating chamber 21 for housing an object to be heated therein, a magnetron 22 for generating microwaves, a waveguide 23 for propagating microwaves, a rotational antenna 24 for radiating microwaves within the heating chamber 21, and an opening sealing plate 25 provided between the heating chamber 21 and the rotational antenna 24.
  • Microwaves generated from the magnetron 22 are propagated through the waveguide 23, and the microwaves having been propagated therethrough are coupled through the rotational antenna 24 and are radiated within the heating chamber 21 through the rotational antenna 24.
  • the rotational antenna 24 is rotated by a rotational driving source such as a motor, thereby uniformizing the microwave distribution within the heating chamber 21.
  • the opening sealing plate 25 provided between the heating chamber 21 and the rotational antenna 24 is provided in order to ensure stable placement of the object to be heated and, also, in order to prevent the rotational antenna 24 and the waveguide 23 from being contaminated and corroded by gasses (water vapor, oils) generated from the object to be heated. Microwaves from the rotational antenna 24 are radiated within the heating chamber 21 by passing through the opening sealing plate 25.
  • the opening sealing plate 25 is formed from a plate member made of a ceramic, a glass and the like.
  • the opening sealing plate 25 provided between the heating chamber 21 and the rotational antenna 24 have a microwave transmission portion with a larger area.
  • the opening sealing plate 25 which allows microwaves to be penetrated has been adapted to largely absorb microwave energy.
  • a plurality of microwave radiating portions for radiating circularly-polarized waves within the heating chamber at desired positions which eliminates the necessity of providing a rotational antenna and a mechanism for rotating the rotational antenna, further, realizes uniform microwave heating on objects to be heated and, further, largely suppresses microwave absorption losses, since the placement portion 3 is constituted by an opening sealing portion as an opening sealing means. This can provide a microwave heater capable of realizing excellent heating efficiency.
  • the microwave transmission area in the opening sealing portion as the placement portion 3 is restricted to a smaller area, which can suppress microwave energy absorption losses in the opening sealing portion.
  • the microwave heaters according to the fifteenth and sixteenth embodiments are capable of increasing the efficiency of heating objects to be heated through microwaves, thereby largely improving the energy saving performance.
  • the microwave heater according to the fifteenth embodiment is different from the microwave heaters according to the aforementioned first to fourteenth embodiments, in that an opening sealing portion as a placement portion within a heating chamber has a specific structure, but the structures of the microwave heaters according to the first to fourteenth embodiments are applied to the other structures.
  • Fig. 25 is a perspective view illustrating the entire structure of a microwave oven as a microwave heater according to the fifteenth embodiment of the present invention.
  • Fig. 26 is a front cross-sectional view of the microwave heater according to the fifteenth embodiment.
  • Fig. 27 is a plan cross-sectional view illustrating the bottom-surface portion and the like in the heating chamber in the microwave heater according to the fifteenth embodiment.
  • the microwave oven 1 as the microwave heater includes the heating chamber 2, wherein the heating chamber 2 is adapted to be surrounded by a door (a front-surface wall) 7 which enables taking in and out an object to be heated, such as food, thereinto and therefrom, and respective wall surfaces (a bottom surface, an upper surface, a left side surface, a right side surface, and a back surface).
  • a door a front-surface wall 7 which enables taking in and out an object to be heated, such as food, thereinto and therefrom, and respective wall surfaces (a bottom surface, an upper surface, a left side surface, a right side surface, and a back surface).
  • an opening sealing portion 10 as an opening sealing means which is penetrated by microwaves from microwave radiating portions 6 (see Fig. 26 ) and for radiating them within the heating chamber 2.
  • the opening sealing portion 10 is constituted by a microwave transmission portion 8 which is penetrated by microwaves, and a microwave reflection portion 9 for reflecting microwaves.
  • the microwave radiating portions 6, which are constituted by opening portions with predetermined shapes which have been described in the aforementioned first to fourteenth embodiments, are provided for radiating, within the heating chamber 2, microwaves having been propagated through the waveguide 5 from the microwave generating device 4.
  • the plurality of the microwave radiating portions 6 are placed oppositely to the microwave transmission portion 8 in the opening sealing portion 10.
  • the microwave transmission portion 8 which is made of a material which is penetrated by microwaves without absorbing them, is placed just above the opening portions in the plurality of the microwave radiating portions 6 and is adapted to cover the opening portions.
  • microwave oven as the microwave heater 1 having the aforementioned structure according to the fifteenth embodiment, in terms of operations and effects thereof.
  • an object to be heated such as an object to be cooked
  • the opening sealing portion 10 which forms the bottom surface of the heating chamber 2 and, then, the door 7 is closed.
  • this activates the microwave generating device 4 through a control portion (not illustrated), thereby generating microwaves therefrom.
  • Microwaves generated therefrom are propagated through the waveguide 5, and circularly-polarized microwaves are radiated from the microwave radiating portions 6 provided in the waveguide 5.
  • Microwaves radiated from the microwave radiating portions 6 are transmitted through the microwave transmission potion 8 in the opening sealing portion 10 and are supplied (radiated) to the inside of the heating chamber 2.
  • the object to be heated is subjected to microwave heating through microwaves supplied to the inside of the heating chamber 2, so that desired cooking is performed thereon.
  • Circular polarization is a technique which has been widely utilized in the fields of mobile communications and satellite communications, as described in the aforementioned first embodiment. Examples of familiar usages thereof include ETCs (Electronic-Toll Collection Systems) "Non-Stop Automated Fee Collection Systems”.
  • a circularly-polarized wave is a microwave having an electric field with a polarization plane which is rotated, with time, with respect to the direction of propagation of radio waves.
  • a circularly-polarized wave When such a circularly-polarized wave is created, its electric field continuously changes with time in direction. Therefore, when circularly-polarized microwaves are radiated within the heating chamber, the microwaves radiated within the heating chamber exhibit the property of continuously changing in angle of radiation, while having a magnitude of electric-field intensity which is substantially unchanged with time.
  • the aforementioned problem of the occurrence of heating unevenness can be overcome, by providing a plurality of microwave radiating portions 6 for radiating circularly-polarized microwaves, as described in the aforementioned first to fourteenth embodiments. Namely, by providing a plurality of microwave radiating portions 6, it is possible to disperse the radiation of microwaves within the heating chamber 2, which can alleviate concentrations of microwaves in comparison with cases of a single microwave radiating opening portion, thereby enabling uniformly heating the object to be heated.
  • the plurality of the microwave radiating portions 6 are structured to radiate circularly-polarized waves, which prevents the occurrence of standing waves due to interferences between microwaves, in principle. Therefore, the microwave heater according to the present invention is enabled to avoid the occurrence of microwaves energy intensity differences due to standing waves within the heating chamber and, therefore, is enabled to uniformly heat the object to be heated.
  • the opening sealing portion 10 is provided as the bottom surface of the heating chamber 2, and the microwave transmission portion 8 in the opening sealing portion 10 is made of a material which is penetrated by microwaves.
  • the microwave transmission portion 8 some parts of microwaves are absorbed by the material of itself, and it is difficult to enable the microwave transmission portion 8 to transmit 100 % of microwaves.
  • the opening sealing portion 10 which forms the bottom surface of the heating chamber 2 is entirely made of the material of the microwave transmission portion 8, this increases the amount of microwaves absorbed by the material of itself, which reduces the energy available for heating the object to be heated, thereby degrading the heating efficiency.
  • the microwave transmission portion 8 as the microwave transmission area in the opening sealing portion 10 is made to be as small as possible.
  • the opening sealing portion 10 is constituted by the microwave transmission portion 8 and the microwave reflection portion 9, and the microwave transmission portion 8 is provided only at a position faced to the microwave radiating portions 6.
  • the microwave heater having the aforementioned structure according to the fifteenth embodiment the area which is penetrated by microwaves can be formed to be smaller, in the opening sealing portion 10, which can suppress absorption of microwaves in the opening sealing portion 10.
  • the microwave heater according to the fifteenth embodiment it is possible to reduce the amount of energy losses in microwaves radiated within the heating chamber 2, which can increase the efficiency of microwave heating for the object to be heated.
  • the microwave transmission portion 8 is structured to cover the opening portions of the microwave radiating portions 6 and has a shape larger than at least the opening portions of the microwave radiating portions 6.
  • the opening sealing portion 10 is made to have a smaller area which is penetrated by microwaves, while the other area is made to be a reflective area. This largely reduces microwave energy losses caused by absorption of microwaves in the microwave transmission portion 8 in the opening sealing portion 10. As a result thereof, with the structure of the microwave heater according to the fifteenth embodiment, it is possible to increase the efficiency of heating of objects to be heated through microwaves, thereby realizing excellent energy saving performance.
  • the microwave heater according to the fifteenth embodiment is of a type for radiating circularly-polarized microwaves within the heating chamber, which eliminates the necessity of providing a rotational antenna and a motor for driving the rotational antenna.
  • the microwave heater according to the fifteenth embodiment can eliminate the necessity of providing a driving space for the rotational antenna and an installation space for a rotational antenna and a mechanism for driving it, which can realize size reduction of the microwave heater.
  • the microwave heater having the reduced size has the excellent advantage of necessitating a reduced installation space in a kitchen and the like.
  • the material of the microwave transmission portion 8 it is preferable to employ a material having a high mechanical strength and high durability while inducing less losses due to microwave absorption.
  • a material having a high mechanical strength and high durability while inducing less losses due to microwave absorption.
  • crystallized glasses containing silicon oxide, aluminum oxide, zirconium oxide, and lithium oxide it is preferable to employ crystallized glasses containing silicon oxide, aluminum oxide, zirconium oxide, and lithium oxide.
  • the microwave heater is provided with no oven function and no grill function or is desired to have cooking temperatures equal to or less than 250 degrees C within the heating chamber
  • materials mainly containing plastics which induce smaller losses due to microwave absorption than those by the aforementioned crystallized glasses.
  • engineering plastics having higher heat resistance, in particular.
  • the opening sealing portion 10 is constituted by the microwave transmission portion 8 and the microwave reflection portion 9. Since the opening sealing portion 10 is provided with the microwave reflection portion 9 having the function of reflecting microwaves, microwaves reflected by the object to be heated within the heating chamber without being absorbed thereby are reflected by the microwave reflection portion 9 and, then, can be directed to the object to be heated, again.
  • the microwave heater according to the fifteenth embodiment due to the provision of the microwave reflection portion 9 therein, it is possible to further increase the efficiency of heating the object to be heated through microwaves, thereby further improving the energy saving performance.
  • the microwave reflection portion 9 by forming the microwave reflection portion 9 from a metal material, it is possible to cause it to exhibit an enhanced microwave reflection property, which can further increase the efficiency of heating of objects to be heated through microwaves.
  • the microwave reflection portion 9 can be also formed from a metal which is provided, on its surface, with a coating layer such as a fluorine coating layer, for example, which prevents microwave absorption therein, such as dielectric losses and magnetic losses.
  • a coating layer such as a fluorine coating layer, for example, which prevents microwave absorption therein, such as dielectric losses and magnetic losses.
  • the microwave heater according to the fifteenth embodiment illustrated in Fig. 27 has been described with respect to an example where it is provided with six microwave radiating portions 6, the number of the microwave radiating portions 6 is not limited and can be properly determined depending on the size of the heating chamber in the microwave heater, the microwave electric power, the types of cookings to be executed, in the structure according to the fifteenth embodiment.
  • the microwave radiating portions 6 are illustrated as having a circular shape in the microwave heater according to the fifteenth embodiment, it is also possible to employ various types of shapes as described in the aforementioned Fig. 4 , as the shapes of the microwave radiating portions 6.
  • the shapes of the microwave radiating portions 6 can be properly determined depending on the size and the shape of the microwave heater, additional members provided in the heating chamber, and the like. In order to realize a uniform heating distribution, the shapes of the microwave radiating portions 6 can be determined by selection from a circular shape, an elliptical shape, a rectangular shape, an X shape, a Y shape and other shapes.
  • the microwave heater according to the sixteenth embodiment is different from the microwave heater according to the aforementioned fifteenth embodiment, in terms of the structure of an opening sealing portion as a placement portion in a heating chamber.
  • Fig. 28 is a front cross-sectional view of the microwave heater according to the sixteenth embodiment of the present invention.
  • Fig. 29 is a plan cross-sectional view illustrating a bottom-surface portion and the like in the heating chamber in the microwave heater according to the sixteenth embodiment.
  • a microwave transmission portion 8 is placed and divided such that it conforms to the shapes of microwave radiating portions 6, in the opening sealing portion 10 as the placement portion 3.
  • the microwave transmission portion 8 in the opening sealing portion 10 as the placement portion 3 is divided into the same number of parts as the number of the plurality of the microwave radiating portions 6 and, thus, is shaped to conform to the shapes of the microwave radiating portions 6.
  • the respective parts of the microwave transmission portion 8 are placed oppositely to the different microwave radiating portions 6, and the microwave transmission portion 8 is adapted to be penetrated by microwave, circularly-polarized microwaves radiated therefrom.
  • Microwaves from a microwave generating device 4 as a microwave generating portion are propagated through a waveguide 5 and are radiated as circularly-polarized waves from the microwave radiating portions 6. Circularly-polarized microwaves radiated therefrom are transmitted through the microwave transmission portion 8 having the shape conforming to the microwave radiating portions 6 and, then, are radiated within the heating chamber 2.
  • the microwave transmission portion 8 is made to have a shape conforming to the microwave radiating portions 6, it is possible to allow the microwave transmission portion 8 in the opening sealing portion 10 to have a minimum necessary transmission area. As a result thereof, with the microwave hater according to the sixteenth embodiment, it is possible to significantly suppress absorption of microwaves by the microwave transmission portion 8, which can increase the efficiency of supply of microwave energy to the heating chamber 2, thereby further increasing the efficiency of heating of objects to be heated.
  • the shape of the microwave transmission portion 8 is preferably a shape conforming to the shapes of the opening portions of the microwave radiating portions 6, but is not particularly limited.
  • the microwave transmission portion 8 it is possible to employ one having the same shape as those of the microwave radiating portions 6. In this case, the microwave transmission portion 8 can be placed such that its shape is overlaid on the opening portions of the microwave radiating portions 6.
  • the microwave transmission portion 8 covers at least the opening portions of the microwave radiating portions 6 and, further, has a circular shape with a diameter which is equal to or slightly larger than the lengths of the longer sides of the slits, for example, in the microwave radiating portions 6.
  • the microwave heater according to the present invention includes the plurality of the microwave radiating portions for radiating circularly-polarized waves within the heating chamber and, therefore, is capable of realizing uniform and efficient microwave heating for objects to be heated.
  • the microwave heater according to the present invention is capable of performing microwave heating on objects to be heated uniformly and efficiently, without being provided with a mechanism for rotating an antenna, a mechanism for rotating a table and a phase shifter. This enables reduction of the cost for the device, reduction of the size of the electricity feeing portion and improvement of the reliability.
  • the microwave heater according to the present invention is capable of uniformly directing microwaves to objects to be heated and, therefore, can be effectively applied to apparatuses for performing heating processes, disinfections and the like and, also, can be applied to heating apparatuses which utilize induction heating and to microwave heaters in various types of appliances, such as garbage disposers, semiconductor fabrication apparatuses.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Constitution Of High-Frequency Heating (AREA)
  • Electric Ovens (AREA)

Claims (18)

  1. Four à micro-ondes (1) comprenant :
    une chambre de chauffage (2) adaptée pour abriter un objet à chauffer ;
    une partie de placement (3) qui forme une surface inférieure de la chambre de chauffage (2) et est adaptée pour accueillir et y placer un objet à chauffer dans la chambre de chauffage (2) ;
    une partie de génération de micro-ondes (4) adaptée pour générer une micro-onde ; et
    un guide d'ondes (5) adapté pour propager la micro-onde à partir de la partie de génération de micro-ondes (4) ;
    caractérisé en ce que
    le four à micro-ondes (1) comprend en outre plusieurs parties rayonnant des micro-ondes (6) qui sont disposées dans une surface du guide d'ondes (5) faisant face à la chambre de chauffage (2) et adaptées pour rayonner des ondes à polarisation circulaire dans la chambre de chauffage (2),
    la pluralité de parties rayonnant des micro-ondes (6) sont placées de manière à être agencées dans une direction orthogonale à une direction (Y) d'un champ électrique et à une direction (X) de propagation dans le guide d'ondes (5),
    et
    chacune des parties rayonnant des micro-ondes (6) est constituée d'au moins deux ou plusieurs fentes, et chacune des parties rayonnant des micro-ondes (6) est formée à des emplacements à l'écart du centre (P) du guide d'ondes (5) dans la direction orthogonale à la direction (X) de propagation et à la direction (Y) du champ électrique,
    où les fentes sont inclinées par rapport à l'axe central (P) du guide d'ondes (5) dans la direction (X) de propagation.
  2. Four à micro-ondes (1) selon la revendication 1, où
    la pluralité de parties rayonnant des micro-ondes (6) est placée juste en-dessous de la partie de placement (3).
  3. Four à micro-ondes (1) selon la revendication 2, où
    les pluralités de parties rayonnant des micro-ondes (6) respectives sont adaptées pour rayonner sensiblement la même quantité de micro-ondes.
  4. Four à micro-ondes (1) selon la revendication 3, où
    la pluralité de parties rayonnant des micro-ondes (6) est placée de manière à être agencée au moins dans une direction de propagation dans le guide d'ondes (5).
  5. Four à micro-ondes (1) selon la revendication 4, où
    la pluralité de parties rayonnant des micro-ondes (6) comprend deux fentes sécantes, et chaque fente est formée de telle manière qu'elle présente un côté plus long incliné par rapport à la direction de propagation dans le guide d'ondes (5).
  6. Four à micro-ondes (1) selon la revendication 4, où
    la pluralité de parties rayonnant des micro-ondes (6) comprend deux fentes sécantes, chaque fente est formée de telle manière qu'elle présente un côté plus long incliné par rapport à la direction de propagation dans le guide d'ondes (5), et les côtés plus longs des fentes ont des longueurs qui varient en fonction de leur position dans la direction de propagation dans le guide d'ondes (5).
  7. Four à micro-ondes (1) selon la revendication 4, où
    la pluralité de parties rayonnant des micro-ondes (6) comprend deux fentes sécantes, chaque fente est formée de telle manière qu'elle présente un côté plus long incliné par rapport à la direction de propagation dans le guide d'ondes (5), et les côtés plus longs des fentes ont des longueurs qui varient en fonction de leur position dans une direction orthogonale à la direction du champ électrique et à la direction de propagation dans le guide d'ondes (5).
  8. Four à micro-ondes (1) selon la revendication 4, où
    la pluralité de parties rayonnant des micro-ondes (6) comprend deux fentes sécantes, chaque fente est formée de telle manière qu'elle présente un côté plus long incliné par rapport à la direction de propagation dans le guide d'ondes (5), et les fentes ont des largeurs qui varient en fonction de leur position dans la direction de propagation dans le guide d'ondes (5).
  9. Four à micro-ondes (1) selon la revendication 4, où
    la pluralité de parties rayonnant des micro-ondes (6) comprend deux fentes sécantes, chaque fente est formée de telle manière qu'elle présente un côté plus long incliné par rapport à la direction de propagation dans le guide d'ondes (5), et les fentes ont des largeurs qui varient en fonction de leur position dans la direction orthogonale à la direction du champ électrique et à la direction de propagation dans le guide d'ondes (5).
  10. Four à micro-ondes (1) selon la revendication 4, où
    la pluralité de parties rayonnant des micro-ondes (6) comprend deux fentes sécantes, chaque fente est formée de telle manière qu'elle présente un côté plus long incliné par rapport à la direction de propagation dans le guide d'ondes (5), et les fentes ont été pourvues d'un chanfrein arrondi (R) ou d'un chanfrein (C) au niveau de leurs parties d'intersection.
  11. Four à micro-ondes (1) selon la revendication 4, où
    la pluralité de parties rayonnant des micro-ondes (6) comprend deux fentes sécantes, chaque fente est formée de telle manière qu'elle présente un côté plus long incliné par rapport à la direction de propagation dans le guide d'ondes (5), et les fentes ont été pourvues d'un chanfrein arrondi (R) ou d'un chanfrein (C) au niveau de leurs parties d'extrémité distales.
  12. Four à micro-ondes (1) selon la revendication 4, où
    la pluralité de parties rayonnant des micro-ondes (6) comprend deux fentes sécantes, chaque fente est formée de telle manière qu'elle présente un côté plus long incliné par rapport à la direction de propagation dans le guide d'ondes (5),
    et
    en ce qui concerne les positions des parties d'intersection des fentes, une partie rayonnant des micro-ondes (6) se trouvant à une grande distance de propagation par rapport à la position où est installée la partie de génération de micro-ondes (4) est formée de manière à avoir un débit de rayonnement de micro-ondes vers la chambre de chauffage (2) à travers le guide d'ondes (5) plus élevé que celui d'une partie rayonnant des micro-ondes (6) se trouvant à une distance de propagation plus petite par rapport à la position où est installée la partie de génération de micro-ondes (4).
  13. Four à micro-ondes (1) selon la revendication 3, où
    la partie de placement (3) adaptée pour accueillir et y placer l'objet à chauffer dans la chambre de chauffage (3) inclut une partie de transmission de micro-ondes (8) pénétrée par des micro-ondes, la partie de transmission de micro-ondes (8) est placée à l'opposé des parties rayonnant des micro-ondes (6), et la partie de transmission de micro-ondes (8) est disposée au moins juste au-dessus des parties rayonnant des micro-ondes (6).
  14. Four à micro-ondes (1) selon la revendication 13, où
    la partie de transmission de micro-ondes (8) présente une forme correspondant aux parties rayonnant des micro-ondes (6).
  15. Four à micro-ondes (1) selon la revendication 14, où
    la partie de placement (3) inclut la partie de transmission de micro-ondes (8) et une partie de réflexion de micro-ondes (9) destinée à réfléchir les micro-ondes.
  16. Four à micro-ondes (1) selon la revendication 15, où
    la partie de transmission de micro-ondes (8) est composée d'un verre cristallisé contenant au moins un matériau parmi de l'oxyde de silicium, de l'oxyde d'aluminium, de l'oxyde de zirconium et de l'oxyde de lithium.
  17. Four à micro-ondes (1) selon la revendication 15, où
    la partie de transmission de micro-ondes (8) est principalement composée d'une matière plastique.
  18. Four à micro-ondes (1) selon la revendication 15, où
    la partie de réflexion de micro-ondes (9) est composée d'un matériau métallique.
EP11845252.3A 2010-11-29 2011-11-22 Four à micro-ondes Active EP2648479B1 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP2010264551 2010-11-29
JP2010266150 2010-11-30
JP2010285588 2010-12-22
JP2011081448 2011-04-01
PCT/JP2011/006487 WO2012073451A1 (fr) 2010-11-29 2011-11-22 Four à micro-ondes

Publications (3)

Publication Number Publication Date
EP2648479A1 EP2648479A1 (fr) 2013-10-09
EP2648479A4 EP2648479A4 (fr) 2014-05-14
EP2648479B1 true EP2648479B1 (fr) 2017-10-25

Family

ID=46171425

Family Applications (1)

Application Number Title Priority Date Filing Date
EP11845252.3A Active EP2648479B1 (fr) 2010-11-29 2011-11-22 Four à micro-ondes

Country Status (3)

Country Link
EP (1) EP2648479B1 (fr)
JP (1) JP5895247B2 (fr)
WO (1) WO2012073451A1 (fr)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103477707B (zh) * 2011-04-01 2016-03-02 松下电器产业株式会社 微波加热装置
JP2014032744A (ja) * 2012-08-01 2014-02-20 Panasonic Corp マイクロ波加熱装置
JP5816820B2 (ja) * 2012-08-29 2015-11-18 パナソニックＩｐマネジメント株式会社 マイクロ波加熱装置
JP6424332B2 (ja) * 2012-09-07 2018-11-21 パナソニックＩｐマネジメント株式会社 マイクロ波加熱装置
WO2014171152A1 (fr) * 2013-04-19 2014-10-23 パナソニック株式会社 Dispositif chauffant à micro-ondes
JP2015195175A (ja) * 2014-03-25 2015-11-05 パナソニックＩｐマネジメント株式会社 マイクロ波処理装置
JP2015185409A (ja) * 2014-03-25 2015-10-22 パナソニックＩｐマネジメント株式会社 マイクロ波処理装置
EP2947961A1 (fr) * 2014-05-20 2015-11-25 Institut De Physique Du Globe De Paris (Établissement Public À Caractère Scientifique Et Technologique) Dispositif de chauffage à micro-ondes
CA3000856A1 (fr) * 2015-09-03 2017-03-09 Commonwealth Scientific And Industrial Research Organisation Appareil de chauffage par micro-onde et procede de chauffage
US10009957B2 (en) 2016-03-30 2018-06-26 The Markov Corporation Electronic oven with infrared evaluative control
EP3252381B1 (fr) 2016-05-31 2021-08-04 Samsung Electronics Co., Ltd. Four de cuisson et procédé de commande correspondant

Family Cites Families (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB977777A (en) * 1962-02-02 1964-12-16 Lyons & Co Ltd J Improvements in or relating to radio frequency ovens
US4301347A (en) * 1980-08-14 1981-11-17 General Electric Company Feed system for microwave oven
US4336434A (en) * 1980-08-15 1982-06-22 General Electric Company Microwave oven cavity excitation system employing circularly polarized beam steering for uniformity of energy distribution and improved impedance matching
JPS61294790A (ja) * 1985-06-24 1986-12-25 株式会社東芝 高周波加熱装置
CH684373A5 (de) * 1992-10-29 1994-08-31 Inwave Ag Vorrichtung zur Einkopplung von Mikrowellen.
JPH08337887A (ja) * 1995-06-12 1996-12-24 Hitachi Ltd プラズマ処理装置
US6097018A (en) * 1998-04-06 2000-08-01 Lg Electronics Inc. Circular polarization generating system for microwave oven
KR100368943B1 (ko) * 1998-07-22 2003-04-10 삼성전자 주식회사 전자렌지
JP4154606B2 (ja) * 2003-02-06 2008-09-24 松下電器産業株式会社 マイクロ波焼成炉
JP2004335304A (ja) * 2003-05-08 2004-11-25 Matsushita Electric Ind Co Ltd 高周波加熱装置
JP2005268624A (ja) * 2004-03-19 2005-09-29 Sumitomo Osaka Cement Co Ltd 加熱装置
EP2453177B1 (fr) * 2007-01-22 2013-08-28 Graphic Packaging International, Inc. Récipient à micro-ondes pour chauffage de four
JP4836965B2 (ja) * 2008-01-18 2011-12-14 三菱電機株式会社 高周波加熱装置
JP4836975B2 (ja) * 2008-02-08 2011-12-14 三菱電機株式会社 加熱調理器

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

Also Published As

Publication number Publication date
CN103229593A (zh) 2013-07-31
EP2648479A1 (fr) 2013-10-09
WO2012073451A1 (fr) 2012-06-07
JP5895247B2 (ja) 2016-03-30
JPWO2012073451A1 (ja) 2014-05-19
EP2648479A4 (fr) 2014-05-14

Similar Documents

Publication Publication Date Title
EP2648479B1 (fr) Four à micro-ondes
EP2741574B1 (fr) Dispositif de chauffage par micro-ondes
EP2824991B1 (fr) Dispositif de chauffage à micro-ondes
US10356855B2 (en) Microwave heating apparatus
EP2852251A1 (fr) Dispositif de chauffage à micro-ondes
US8803051B2 (en) Microwave oven
JP5991595B2 (ja) マイクロ波加熱装置
JP2000030853A (ja) 電子レンジおよび導波管システム
WO2016006249A1 (fr) Dispositif de chauffage à micro-ondes
JP6273598B2 (ja) マイクロ波加熱装置
JP5816820B2 (ja) マイクロ波加熱装置
WO2013001787A1 (fr) Dispositif de chauffage micro-onde
JP2015015225A (ja) マイクロ波加熱装置
JP7378019B2 (ja) マイクロ波処理装置
JP3690094B2 (ja) 高周波加熱装置
WO2016103585A1 (fr) Dispositif de chauffage aux micro-ondes
CN117425240A (zh) 微波组件和烹饪器具
JP5877304B2 (ja) マイクロ波加熱装置
JP2014053231A (ja) マイクロ波加熱装置
JP6424332B2 (ja) マイクロ波加熱装置
CN117676945A (zh) 微波加热设备
JP2013120632A (ja) マイクロ波加熱装置
JP2004063311A (ja) マイクロ波加熱装置
JP2013109987A (ja) マイクロ波加熱装置

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20130612

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAX Request for extension of the european patent (deleted)
REG Reference to a national code

Ref country code: DE

Ref legal event code: R079

Ref document number: 602011042791

Country of ref document: DE

Free format text: PREVIOUS MAIN CLASS: H05B0006720000

Ipc: H05B0006700000

A4 Supplementary search report drawn up and despatched

Effective date: 20140411

RIC1 Information provided on ipc code assigned before grant

Ipc: H05B 6/70 20060101AFI20140407BHEP

Ipc: H05B 6/74 20060101ALI20140407BHEP

Ipc: H05B 6/72 20060101ALI20140407BHEP

17Q First examination report despatched

Effective date: 20160713

GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

INTG Intention to grant announced

Effective date: 20170530

RIN1 Information on inventor provided before grant (corrected)

Inventor name: KUBO, MASAYUKI

Inventor name: HOSOKAWA, DAISUKE

Inventor name: FUKUDA, HIROSHI

Inventor name: YOSHINO, KOJI

Inventor name: SADAHIRA, MASAFUMI

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: AT

Ref legal event code: REF

Ref document number: 941041

Country of ref document: AT

Kind code of ref document: T

Effective date: 20171115

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 602011042791

Country of ref document: DE

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20171025

REG Reference to a national code

Ref country code: LT

Ref legal event code: MG4D

REG Reference to a national code

Ref country code: AT

Ref legal event code: MK05

Ref document number: 941041

Country of ref document: AT

Kind code of ref document: T

Effective date: 20171025

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: NO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180125

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180126

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180225

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180125

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: AT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 602011042791

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20171130

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20171130

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20171122

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20180731

Ref country code: BE

Ref legal event code: MM

Effective date: 20171130

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20171122

26N No opposition filed

Effective date: 20180726

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20171226

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20171122

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20171130

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20111122

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20171025

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20231123

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20231121

Year of fee payment: 13