JP2018166035A - Microwave heating device and image recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress influences caused by thermal expansion of a heating chamber upon alignment of microwaves.SOLUTION: A microwave heating device comprises: a microwave generation part which radiates a microwave into a heating chamber; a short-circuit plate which reflects the microwave; and an aligner which re-reflects a microwave reflected by the short-circuit plate. The short-circuit plate is fixed and held by a support member, and the support member is coupled to a wall of the heating chamber by a coupling member. A thermal expansion coefficient of the support member and the coupling member is equal to or greater than a thermal expansion rate coefficient of a member forming the heating chamber. Thus, even in a case where thermal expansion occurs in the heating chamber, the support member and the coupling member are also thermally expanded together, thereby suppressing the thermal expansion of the heating chamber, and influences upon alignment of microwaves can be suppressed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a microwave heating apparatus that heats an object to be heated by microwaves, and an image recording apparatus including the microwave heating apparatus.

  Conventionally, a microwave heating apparatus that outputs microwaves and heats an object to be heated is known (for example, Patent Document 1). Such a microwave heating apparatus includes a conductive heating chamber in which microwaves are guided and a terminal portion in a microwave entering direction is short-circuited.

  According to such a configuration, the microwave guided to the heating chamber (hereinafter referred to as an incident wave) matches the microwave reflected in the heating chamber (hereinafter referred to as a reflected wave). The object to be heated can be efficiently heated. In this case, it is important to match the wavelengths of the incident wave and the reflected wave so as to strengthen each other most.

  However, as the temperature of the heated object rises, the temperature of the heating chamber itself also rises. For this reason, the casing constituting the heating chamber is thermally expanded, and the entire length of the casing is increased. Thereby, the reflection timing of the reflected wave with respect to the incident wave is different in advance, and there is a problem that the heating efficiency is lowered.

  Thus, for example, Patent Document 2 discloses means for preventing the influence of the member due to thermal expansion due to temperature rise. Specifically, in order to prevent the position of the aperture hole from changing due to thermal expansion in the electron microscope and causing an axial shift, the electron beam aperture plate is folded in half. Then, by fixing the lower diaphragm plate, the upper electron beam diaphragm plate and the lower electron beam diaphragm plate are thermally expanded in opposite directions, respectively, so that a change in the position of the diaphragm hole can be prevented.

JP 2013-97976 A JP-A-6-139981

  In the microwave heating apparatus, it is necessary to resonate the microwave in order to efficiently heat the object to be heated. However, it is not disclosed until the technique of Patent Document 2 is applied to the microwave heating apparatus, and the influence of the thermal expansion of the heating chamber cannot be prevented.

  The present invention has been made in view of the above problems, and provides a microwave heating apparatus and an image recording apparatus including the microwave heating apparatus that can suppress the influence on the matching of the microwaves due to the thermal expansion of the heating chamber. For the purpose.

  A microwave heating apparatus according to a first aspect of the present invention, which is installed in a heating chamber that houses an object to be heated, a microwave generator that radiates microwaves into the heating chamber, and a microwave traveling direction. The short-circuit plate that reflects the microwave and partitions the heating chamber and the space to be heated is provided between the microwave generator and the heating chamber, and the reflected microwave reflected by the short-circuit plate is heated in the heating space. A matching unit that re-reflects in, a support member that supports the short-circuit plate from the non-heating space side, and a connection member that holds the support member fixedly and connects to the wall of the heating chamber facing the microwave generation unit, A position adjusting mechanism that adjusts the distance of the short-circuit plate with respect to the matching device by changing the position where the supporting member is fixedly held by the connecting member, and the coefficient of thermal expansion of the supporting member and the connecting member forms a heating chamber. Less than the coefficient of thermal expansion And characterized in that.

  A 2nd aspect is a microwave heating device which concerns on a 1st aspect, Comprising: A supporting member and a connection member are members which have the same thermal expansion coefficient, It is characterized by the above-mentioned.

  An image recording apparatus according to a third aspect of the present invention, wherein the head unit ejects a plurality of ink droplets toward the base material based on the image data, and is ejected from the head unit and adheres to the surface of the base material A microwave heating unit that irradiates the ink with microwaves to heat and dry the ink, and a moving unit that moves the substrate relative to the head unit and the microwave heating unit. A heating chamber having a substrate carrying-in port for carrying in the material, a substrate carrying-out port for carrying out the substrate, and a microwave orthogonal to the direction of carrying the substrate into the heating chamber and parallel to the surface of the substrate A microwave generation unit that radiates, a short-circuit plate that is installed in the traveling direction of the microwave, reflects the microwave, and partitions the heating space and the space to be heated, and between the microwave generation unit and the heating chamber Reflected by the short-circuit plate A matching unit that re-reflects the reflected microwave into the heating space, a support member that supports the short-circuit plate from the non-heating space side, and a support member that is fixedly held and connected to the wall of the heating chamber that faces the microwave generation unit. And a position adjusting mechanism that adjusts the distance of the short-circuit plate with respect to the aligner by changing the position where the support member is fixedly held by the connection member, and the coefficient of thermal expansion of the support member and the connection member is The thermal expansion coefficient of the member forming the heating chamber is equal to or higher than that.

  A 4th aspect is an image recording device which concerns on a 3rd aspect, Comprising: The microwave heating part has two or more along the conveyance direction of a base material, The short circuit board and matching device with which each microwave heating part is provided The thickness of the dielectric layer to be configured is adjusted so that the peak positions where the microwaves are matched differ from each other in the width direction of the base material.

  In the invention configured as described above, since the influence of the thermal expansion of the heating chamber can be suppressed, stable heating and drying can be performed.

It is a perspective view showing a schematic structure of one embodiment of a microwave heating device concerning the present invention. It is a schematic sectional drawing in the XZ plane of a microwave heating device. It is the front view which looked at the microwave heating device from the X direction. It is a figure which shows the state before thermal expansion by heating in a microwave heating apparatus, and after thermal expansion. It is a figure which shows schematic structure of the image recording apparatus which shows 2nd Embodiment. It is a perspective view which shows schematic structure of the microwave heating part of FIG. It is a figure which shows the schematic cross section of the microwave heating part which concerns on 3rd Embodiment. It is a top view which shows schematic structure of the microwave heating part of FIG. It is a figure which shows the temperature distribution of the base material in 3rd Embodiment.

  A first embodiment of the present invention will be described with reference to the drawings.

  An embodiment of a microwave heating apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a schematic configuration of the microwave heating apparatus 10. FIG. 2 shows a schematic cross section of the microwave heating apparatus 10 on the XZ plane. FIG. 3 is a front view of the microwave heating apparatus 10 as viewed from the X direction.

  The microwave heating apparatus 10 mainly includes a microwave generation unit 20 composed of a magnetron or the like, and an object to be heated, and heats the object to be heated by the microwave radiated from the microwave generation unit 20. A heating chamber 40, a matching unit 30 provided between the microwave generator 20 and the heating chamber 40, a short-circuit plate 44 disposed in the traveling direction of the microwave in the heating chamber 40, and the matching unit 30 And a position adjusting mechanism 42 for adjusting the distance of the short-circuit plate 44 with respect to. Note that an isolator for converting the microwave power into heat energy and causing the microwave generator 20 to operate stably may be provided between the microwave generator 20 and the matching unit 30. In addition, various members such as a semiconductor substrate and a liquid crystal substrate can be heat-treated as an object to be heated.

  The microwave generation unit 20 is attached at a position corresponding to a microwave introduction port (not shown) of the wall W <b> 1 (FIG. 2) of the heating chamber 40. Then, the microwave generator 20 generates a microwave MW. By attaching the microwave generation unit 20 to a position corresponding to the microwave inlet of the wall W <b> 1 of the heating chamber 40, the microwave generation unit 20 radiates the microwave MW into the heating chamber 40 via the matching unit 30. be able to.

  The heating chamber 40 is a housing having a hollow structure that is long in the X direction, and an opening 41 that allows a heated object to be taken in and out is formed in the wall W3. That is, the opening 41 is provided on a surface (wall W3) different from the surface (wall W1) where the microwave introduction port is formed and the surface (wall W2) facing the microwave introduction port. The opening 41 is provided with a shutter (not shown).

  A microwave introduction port for guiding the microwave MW to the inside is provided on the wall W1 that is the side surface of the heating chamber 40 on the microwave generation unit 20 side. Therefore, the microwave output from the microwave generation unit 20 is guided into the heating chamber 40 from the microwave introduction port in the X direction from the microwave generation unit 20 side. The inside of the heating chamber 40 functions as a waveguide. As such a constituent material of the heating chamber 40, for example, aluminum, copper, stainless steel, or the like can be used. Therefore, the entire heating chamber 40 is heated by heat conduction. The heating chamber 40 has a shield structure. Thereby, the outflow of the microwave from the heating chamber 40 can be prevented.

  The matching unit 30 is made of a material having a high dielectric constant. For example, the matching unit 30 is made of a resin material such as high density polyethylene (UHMW) or polytetrafluoroethylene, quartz, or other high dielectric constant material. It is the adjusted plate-shaped member. In the present embodiment, the thickness of the dielectric layer is adjusted to be 1/3 of the microwave wavelength in the matching unit 30. By arranging the matching unit 30, which is a member made of a high dielectric constant material, at the microwave inlet of the heating chamber 40, the matching unit 30 generates the electric field strength of the microwave generated by the microwave generator 20. It can be larger than twice. The matching unit 30 is preferably made of a material that is not easily heated as much as possible. From the viewpoint of processability and cost, it is preferable to use high-density polyethylene practically.

  The short-circuit plate 44 is a plate-like member formed of high-density polyethylene and is short-circuited. The short-circuit plate 44 is installed inside the heating chamber 40 in the traveling direction of the microwave MW, reflects the microwave MW, accommodates the object to be heated in the heating chamber 40, and heats the heating space HS. It is partitioned into a non-heating space NHS that accommodates a part of a position adjusting mechanism 42 that adjusts the position of a short-circuit plate 44 described later without accommodating an object. The surface on the heating space HS side of the short-circuit plate 44 forms a reflection surface that reflects the microwave MW. Further, a slider is provided between the peripheral edge of the short-circuit plate 44 and the inner wall surface of the heating chamber 40, and the short-circuit plate 44 can slide in the length direction of the heating chamber 40 within the heating chamber 40. It has become.

  When the object to be heated is heat-treated in the heating space HS, the atmosphere inside the object is also heated, and the entire wall of the heating chamber 40 is heated by heat conduction. Accordingly, the non-heated space NHS is also heated as a result.

  The position adjustment mechanism 42 is formed on a support member 43 that supports the short-circuit plate 44 from the non-heating space NHS side, and is formed on the wall W2 of the heating chamber 40 that holds the support member 43 fixed and faces the microwave generation unit 20. The connecting member 45 is connected to the opening to be omitted.

  The support member 43 is connected to the short-circuit plate 44 and has a length protruding from the wall W2 of the heating chamber 40, and the shape thereof is a quadrangular column. Note that the shape of the support member 43 is not limited to a quadrangular prism, and may be a cylindrical shape or other shapes.

  The connecting member 45 is connected to an opening formed in the wall of the heating chamber 40 and has a ring shape. Therefore, the periphery of the support member 43 can be fixed and held. The connecting member 45 can be switched between a state in which the support member 43 is fixedly held and a state in which the support member 43 is released.

  Therefore, the distance of the short-circuit plate 44 relative to the matching device 30 can be adjusted by changing the position where the support member 43 is fixedly held in the connecting member 45. Thereby, the phase shift between the phase of the incident wave IW of the microwave and the phase of the reflected wave RW can be arbitrarily adjusted, and the phase can be adjusted so that the resonance between the incident wave IW and the reflected wave RW becomes maximum. .

  The position adjustment of the short-circuit plate 44 with respect to the aligner 30 by the position adjustment mechanism 42 is performed before the heat treatment is performed. During the heat treatment, the connecting member 45 is in a state where the support member 43 is fixedly held.

  Further, the support member 43 and the connecting member 45 are configured by members having a thermal expansion coefficient equal to or higher than the thermal expansion coefficient of the members constituting the heating chamber 40. Specifically, for example, when the heating chamber 40 is made of aluminum, the support member 43 and the connecting member 45 are preferably made of polytetrafluoroethylene. When these members are employed, the linear expansion coefficient of polytetrafluoroethylene is about 4 times larger than that of aluminum. In the present embodiment, the thermal expansion coefficient is equivalent to the linear expansion coefficient in consideration of elongation in the length direction. Moreover, it is preferable that the support member 43 and the connection member 45 are members having the same thermal expansion coefficient.

  In FIG. 4, the state of the microwave heating device 10 before the heat treatment is shown in FIG. 4A, and the state of the microwave heating device 10 in a state where thermal expansion is caused by the heat treatment is shown in FIG. Yes. In any of the drawings, the heating chamber 40 is made of aluminum, and the position adjusting mechanism 42 is made of polytetrafluoroethylene.

  In FIG. 4A, the influence of the heat treatment does not occur, and the dimension in the X direction of the heating chamber 40 (in other words, the distance between the matching unit 30 and the short-circuit plate 44) remains set in advance. However, when the object to be heated is irradiated with the microwave MW, the temperature in the heating space HS rises, and the temperature of the heating chamber 40 rises. The heating chamber 40 is made of aluminum, and thermal expansion occurs due to a temperature rise. In particular, the heating chamber 40 extends in the X direction due to thermal expansion.

  On the other hand, in this embodiment, since the position adjusting mechanism 42 is made of polytetrafluoroethylene, thermal expansion occurs in the support member 43 and the connecting member 45 as shown in FIG. However, since polytetrafluoroethylene has a larger coefficient of thermal expansion than aluminum, the support member 43 and the connecting member 45 made of polytetrafluoroethylene have a thermal expansion so as to suppress displacement due to the thermal expansion generated in aluminum. Do. Thereby, the displacement of the distance of the matching device 30 and the short circuit board 44 which were set beforehand can be suppressed. Therefore, it is possible to suppress the occurrence of misalignment due to thermal expansion and perform stable continuous operation.

  A second embodiment of the present invention will be described with reference to the drawings.

  An embodiment of an image recording apparatus provided with a microwave heating unit according to the present invention will be described with reference to FIGS. FIG. 5 is a diagram showing a schematic configuration of the image recording apparatus 1. 6 is a perspective view showing a schematic configuration of a microwave heating unit 10A provided in the image recording apparatus 1. FIG.

  The image recording apparatus 1 records an image on the surface of the substrate P by ejecting ink droplets toward the substrate P such as a long strip of printing paper by an inkjet method.

  The image recording apparatus 1 includes a moving unit 3 that moves the base material P, a head unit 4, a microwave heating unit 10A, and a control unit 7.

  The moving unit 3 includes an unwinding unit 5 on which the roll-shaped substrate P is disposed, and a winding unit 6 that is unwound from the unwinding unit 5 and then horizontally transported in the longitudinal direction and wound up in a roll shape. And a plurality of auxiliary rollers 3a that support the base material P in the middle of conveyance. The moving unit 3 rotates, for example, a drive motor provided in the winding unit 6 and detects the conveyance speed, position information, and the like of the substrate P with a rotary encoder or the like.

  In the section in which the base material P is horizontally transported, the head unit 4 and the microwave heating unit 10A are provided along the transport direction of the base material P. The head unit 4 includes a first head 4C, a second head 4M, a third head 4Y, and a fourth head 4K that are arranged above the base material P that is horizontally transported and arranged in the transport direction of the base material P. For example, the first head 4C produces C (cyan) ink drops, the second head 4M produces M (magenta) ink drops, the third head 4Y produces Y (yellow) ink drops, and the fourth head 4K produces K ink. A plurality of (black) ink droplets are ejected toward the surface (upper surface) of the substrate P. In addition, the first head 4C, the second head 4M, the third head 4Y, and the fourth head 4K are configured to selectively eject large, medium, and small ink droplets of three different sizes, for example. Yes.

  The first head 4C is arranged on the bottom surface facing the base material P over a direction (also referred to as the width direction of the base material P) that is orthogonal to the transport direction of the base material P and parallel to the top surface of the base material P. A plurality of ejection openings (not shown) are provided, and C ink droplets are respectively ejected from the plurality of ejection openings. The plurality of ejection openings are provided over the dimension in which an image is to be recorded in the width direction of the substrate P. Similarly, the second head 4M, the third head 4Y, and the fourth head 4K are also provided with a plurality of ejection openings, respectively.

  10 A of microwave heating parts are arrange | positioned in the downstream in the conveyance direction of the base material P of the head part 4. As shown in FIG. 10 A of microwave heating parts are discharged toward the base material P by the head part 4, and irradiate a microwave to the base material P to which the ink has adhered to the surface, and perform the drying process with respect to the base material P. FIG. The microwave with which the substrate P is irradiated by the microwave heating unit 10A is a microwave having a wavelength of 150 mm and a frequency of 2.45 GHz, for example.

  The control unit 7 is a computer having a CPU, a memory (ROM, RAM, etc.), and is electrically connected to the head unit 4, the microwave heating unit 10A, and the moving unit 3, respectively. Then, image data to be recorded is stored in the memory, converted into a recording signal for driving the head unit 4 by known image data processing, and controlled to eject ink droplets from the head unit 4. Further, the moving unit 3 is controlled based on an input from an encoder or the like.

  As shown in FIG. 6, the microwave heating unit 10 </ b> A contains a microwave generation unit 20 </ b> A composed of a magnetron or the like, and an object to be heated inside, and the substrate P is formed by microwaves radiated from the microwave generation unit 20. A heating chamber 40 for heating the heating chamber, a matching unit 30 provided between the microwave generator 20A and the heating chamber 40, and a short-circuit plate (not shown) disposed in the traveling direction of the microwave in the heating chamber 40 And a position adjusting mechanism 42 that adjusts the distance to the matching unit 30. In addition, in each part, the same code | symbol is provided about the same structure as the microwave heat processing apparatus in 1st Embodiment, and description is abbreviate | omitted.

  The heating chamber 40 includes a slit-shaped carry-in port (not shown) that receives the substrate P, and a slit-shaped carry-out port 41A through which the substrate P is discharged.

  And the base material P which was discharged toward the base material P by the head part 4 and the ink adheres to the surface is carried in into the entrance of the heating chamber 40 of 10 A of microwave heating parts, and the inside of the heating chamber 40 The microwave is irradiated, the ink on the substrate P is heated and dried, and the substrate P is carried out from the carry-out port 41A.

  In this embodiment, since the microwave heating unit 10A has the same configuration as that of the first embodiment, even if the thermal expansion of the heating chamber 40 occurs, the microwave alignment adjusted in advance can be maintained and stable. Continuous operation is possible.

  Next, a third embodiment of the present invention will be described with reference to the drawings. The third embodiment is different from the second embodiment in a microwave heating unit 10B. Therefore, only the microwave heating unit 10B will be described with reference to FIGS. FIG. 7 is a diagram showing a schematic cross section of the microwave heating unit 10B, and FIG. 8 is a top view showing a schematic configuration of the microwave heating unit 10B.

  In the description of the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. The differences will be mainly described.

  The microwave heating unit 10B includes a microwave generating unit 20B and three heating chambers 40A, 40B, and 40C. Moreover, the main difference in each heating chamber 40A-40C is the thickness of the dielectric material layer in short circuit board 44A-44C and matching device 30A-30C. Thus, the most resonating peak position in the microwave can be controlled in the width direction of the base material P by the thicknesses of the dielectric layers being different.

  FIG. 9 shows the temperature distribution in the width direction of the base material P in each of the heating chambers 40A to 40B. In particular, the solid line 401A indicates the temperature distribution in the width direction relative to the substrate P in the heating chamber 40A, the broken line 401B indicates the temperature distribution in the width direction relative to the substrate P in the heating chamber 40B, and the alternate long and short dash line 401C indicates the temperature distribution in the heating chamber 40C. The temperature distribution of the width direction with respect to the base material P is shown.

  As shown in FIG. 8, by adjusting the thickness of the dielectric layers in the short-circuit plates 44 </ b> A to 44 </ b> C and the matching units 30 </ b> A to 30 </ b> C included in the heating chambers 40 </ b> A to 40 </ b> C, The peak position to be made can be varied in the width direction of the substrate P. A temperature rise occurs at a position on the substrate P where the peak of the microwave is high. Therefore, the peak position of the microwave corresponds to the temperature distribution in the width direction of the substrate P. As shown in the present embodiment, by shifting the positions of the microwave peaks of the heating chambers 40A to 40C in the width direction of the base material P, it is possible to uniformly heat and dry the base materials P in the width direction.

  While the embodiments have been described above, the present invention is not limited to the above, and various modifications can be made.

  In the second and third embodiments, the printing paper is taken as an example of the substrate P, but is not limited thereto, and for example, a substrate such as a film or a metal foil may be used.

  In the second and third embodiments, the heating chamber is disposed on the downstream side in the transport direction of the head unit 4. However, the present invention is not limited to this. For example, the heating chamber is disposed on the upstream side in the transport direction of the head unit 4. The base P can be used as a preheat for preheating.

  Although the present invention has been described in detail, the above description is illustrative in all aspects, and the present invention is not limited thereto. It is understood that countless variations that are not illustrated can be envisaged without departing from the scope of the present invention. Moreover, each structure demonstrated by the said embodiment can be suitably combined unless it mutually contradicts.

DESCRIPTION OF SYMBOLS 1 Image recording device 3 Moving part 4 Head part 7 Control part 10 Microwave heating apparatus 10A, 10B Microwave heating part 20, 20A, 20B Microwave generation part 30, 30A-30C Matching device 40, 40A-40C Heating chamber 42 Position Adjustment mechanism 43 Support member 44 Short-circuit plate 45 Connecting member IW Incident wave RW Reflected wave MW Microwave HS Heating space NHS Non-heating space P Base material

Claims (4)

A heating chamber for storing an object to be heated;
A microwave generator for radiating microwaves into the heating chamber;
A short-circuit plate that is installed in the traveling direction of the microwave, reflects the microwave, and partitions the heating space and the heated space in the heating chamber;
A matching unit provided between the microwave generation unit and the heating chamber and re-reflecting the reflected microwave reflected by the short-circuit plate into the heating space;
A support member that supports the short-circuit plate from the non-heating space side, and a connection member that fixes and holds the support member and connects to the wall of the heating chamber facing the microwave generation unit, and the support member A position adjusting mechanism for adjusting a distance of the short-circuit plate with respect to the matching device by changing a position to be fixedly held by the connecting member;
The microwave heating apparatus, wherein the support member and the connecting member have a thermal expansion coefficient equal to or higher than a thermal expansion coefficient of a member forming the heating chamber. The microwave heating apparatus according to claim 1,
The microwave heating apparatus, wherein the support member and the connecting member are members having the same thermal expansion coefficient. A head unit that ejects a plurality of ink droplets based on image data toward the substrate;
A microwave heating unit that irradiates the ink discharged from the head unit and adheres to the surface of the substrate with microwaves, and heats and drys the ink;
A moving unit that moves the substrate relative to the head unit and the microwave heating unit,
The microwave heating unit is
A heating chamber having a substrate carrying-in port for carrying in the substrate and a substrate carrying-out port carrying out the substrate;
A microwave generator that radiates microwaves in a direction perpendicular to the direction in which the substrate is transported into the heating chamber and parallel to the surface of the substrate;
A short-circuit plate that is installed in the traveling direction of the microwave, reflects the microwave, and partitions the heating space and the heated space in the heating chamber;
A matching unit provided between the microwave generation unit and the heating chamber and re-reflecting the reflected microwave reflected by the short-circuit plate into the heating space;
A support member that supports the short-circuit plate from the non-heating space side, and a connection member that fixes and holds the support member and connects to the wall of the heating chamber facing the microwave generation unit, and the support member A position adjusting mechanism for adjusting a distance of the short-circuit plate with respect to the matching device by changing a position to be fixedly held by the connecting member;
An image recording apparatus, wherein the support member and the connecting member have a thermal expansion coefficient equal to or greater than a thermal expansion coefficient of a member forming the heating chamber. The image recording apparatus according to claim 3,
Having a plurality of the microwave heating unit along the transport direction of the substrate,
The thickness of the dielectric layer constituting the matching plate and the short-circuit plate provided in each of the microwave heating units is adjusted so that the peak positions where the microwaves resonate are different with respect to the width direction of the substrate. An image recording apparatus.