JP2009133515A - Dryer and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dryer capable of quickly drying a body to be dried, and a printer capable of achieving high-speed printing with favorable printing quality. <P>SOLUTION: In this dryer, a microwave head 50 radiating microwaves to paper includes a pair of pole plates 51A, 52A disposed in parallel, the radii r of the paired pole plates 51A, 52A are set to X<SB>1</SB>×v/ω, and paper is made to pass between the paired pole plates 51A, 52A to dry the paper (wherein 2.3<X<SB>1</SB><2.5, the angular frequency of the microwave :ω=2πf, the frequency of the microwave: f, and the speed of the microwave: v.). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a drying device and a printer including the drying device.

Conventionally, in order to increase the printing speed and resolution of an ink jet printer, there has been a problem of “bleeding” due to further application of ink before the applied ink is sufficiently dried. In order to avoid this, it is effective to optimize the ink application amount by detecting the paper quality (moisture amount and material) before printing, or to dry the applied ink at high speed. .
From the viewpoint of energy efficiency to be used, for example, heating by microwaves such as a microwave oven can directly give energy to a substance, and thus is more efficient than heating by heat transfer. A microwave transmission source such as a magnetron has low power utilization efficiency. However, if a microwave power source using a solid oscillation source is used, power saving and high efficiency excitation can be achieved.

For example, as disclosed in Patent Document 1, there has been proposed a method of heating and drying ink adhering to printing paper using a microwave.
Special Table 2003-534164

  However, in the method of Patent Document 1, since the ink is dried without detecting the amount of moisture contained in the paper, depending on the amount of moisture, it may take a long time to dry, which is not efficient. It was difficult to perform high-speed printing. In addition, if the amount of water contained in the paper is large, depending on the type of paper, the ink may penetrate to the back side of the paper, and ink bleeding may occur. When this ink bleed occurs, it becomes difficult to print the back surface cleanly, which is not preferable in the case of printing such as double-sided printing. In addition, if a magnetron is used as a microwave transmission source for generating microwaves, the device becomes enormous, and a structure suitable for a printer with a high demand for miniaturization used in the workplace or at home. I can not say.

  The present invention has been made in view of the above-described problems of the prior art, and aims to provide a drying apparatus capable of quickly drying an object to be dried and a printer capable of high-speed printing with good print quality. Yes.

In order to solve the above problems, the drying apparatus of the present invention is a drying apparatus that dries an object to be dried. In the drying apparatus, a microwave radiating unit that radiates microwaves to the object to be dried is a pair of electrode plates arranged in parallel. And a radius r of the pair of electrode plates is set to X ₁ × v / ω, and the object to be dried passes between the pair of electrode plates (provided that 2.3 <X ₁ <2.5, angular frequency of the microwave: ω = 2πf, frequency of the microwave: f, velocity of the microwave: v).

ADVANTAGE OF THE INVENTION According to this invention, a to-be-dried body can be effectively dried by the effect | action of the electric field which generate | occur | produces between electrode plates. In addition, by appropriately setting the radius r of the electrode plate, it is possible to contain the microwave in the microwave radiation portion (cylindrical resonator) without using a shield. Thereby, energy density improves and highly efficient drying can be performed in a short time.
Here, X ₁ is preferably the first root of the Bessel function (X> 0 and the root closest to X = 0).

Moreover, it is preferable that the distance between the inner surfaces of the pair of electrode plates is approximately half the wavelength of the microwave.
According to the present invention, microwave energy can be most concentrated at a substantially central portion between the substrates. By passing the material to be dried there, the temperature of the material to be dried can be raised immediately, and the drying efficiency is improved.

The drying apparatus according to the present invention is a drying apparatus for drying an object to be dried, wherein the microwave radiating unit for radiating microwaves to the object to be dried is a pair of cylindrical antennas arranged with their axes aligned and spaced apart. The to-be-dried body passes between the cylindrical antennas in a direction perpendicular to the axis.
ADVANTAGE OF THE INVENTION According to this invention, a to-be-dried body can be heated more effectively by the effect | action of the electric field which generate | occur | produces between a pair of antennas. Since the energy of the microwave is most concentrated between the pair of antennas, the drying efficiency can be increased by arranging the object to be dried between the antennas.

The drying apparatus according to the present invention is a drying apparatus for drying an object to be dried, wherein the microwave radiating unit for radiating microwaves to the object to be dried is a pair of cylindrical antennas arranged with their axes aligned and spaced apart. And a conductor disposed near the antenna, and the object to be dried passes between the pair of antennas and the conductor in a direction parallel to the axis.
ADVANTAGE OF THE INVENTION According to this invention, a to-be-dried body can be heated more effectively by the effect | action of the electric field which generate | occur | produces between a pair of antenna and conductor. In the microwave, energy is most concentrated between the pair of antennas and the conductor, and the drying efficiency can be increased by disposing an object to be dried between the antenna and the conductor. Moreover, in this invention, since the longitudinal direction of the microwave radiation | emission part is made parallel to the passing direction of a to-be-dried body, the microwave radiation | emission part can be made low-profile and size reduction of a drying apparatus can be achieved. Furthermore, it can be easily incorporated into other devices, and the degree of freedom in design is improved.

Moreover, it is preferable that the length and the aperture diameter of the microwave radiation portion coincide with an integral multiple or a fraction of an integer of a half wavelength of the microwave.
According to the present invention, microwave energy can be most concentrated at the place where the object to be dried is disposed. Therefore, the drying efficiency of the object to be dried can be improved and the drying can be performed in a short time.

Further, it is preferable that the pair of antennas have the same length, and the object to be dried passes through the central portion in the length direction of the microwave radiation portion.
According to the present invention, the object to be dried passes through the central portion in the length direction of the microwave radiating part, that is, between the antennas, and the microwave energy is most concentrated between the antennas where the object to be dried is disposed. be able to.

Moreover, it is preferable that the front-end | tip part which a pair of antenna mutually opposes is diameter-reduced.
ADVANTAGE OF THE INVENTION According to this invention, the energy of the microwave between antennas with which a to-be-dried body is arrange | positioned can be improved further.

In addition, a microwave power supply unit that supplies microwaves to the microwave radiating unit is provided, and the microwave power supply unit amplifies the microwave and a reflected wave detection unit that detects a reflected wave according to the dry state of the object to be dried It is preferable to include an amplification circuit, a reflected wave detection unit that detects a reflected wave according to a dry state of the object to be dried, and a control unit that controls the amplification circuit based on the output of the reflected wave detection unit.
According to the present invention, by irradiating the object to be dried with microwaves, the moisture content contained in the object to be dried can be examined and dried almost simultaneously, so that the object can be dried in a short time. Efficient. Moreover, it can be dried neatly with less blur. Moreover, since the energy of the microwave can be adjusted according to the moisture content of the object to be dried, it is possible to suppress wasteful power consumption.

In addition, the microwave radiating unit includes an inductor connected to the microwave radiating unit, and the complex impedance of the microwave radiating unit when the object to be dried contains moisture and the complex impedance obtained by combining the impedances of the inductors. It is preferably conjugate with the complex impedance at the output terminal.
ADVANTAGE OF THE INVENTION According to this invention, it can grasp | ascertain that the moisture content of the to-be-dried body which exists in a microwave radiation | emission part decreased, and can detect the time of a to-be-dried body drying. Thereby, since drying can be completed when a to-be-dried body dries, drying deficiency can be reduced.

A printer according to the present invention includes a droplet discharge head that discharges droplets onto an object to be dried, and the drying device according to any one of claims 1 to 9.
According to the present invention, as described above, according to the present invention, the liquid droplet drying capable of detecting the amount of moisture contained in the object to be dried and drying the liquid droplets disposed on the object to be dried. Since the apparatus is mounted, even in the case of double-sided printing such as printing on the front and back surfaces of the pessimistic apparatus, there is little blur and beautiful printing can be performed. Moreover, since the detection of the amount of moisture contained in the object to be dried and the drying of the droplets can be performed substantially simultaneously, a printer capable of realizing high-speed printing can be provided.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[Printer]
FIG. 1 is a perspective view showing a configuration of a printer equipped with the droplet drying apparatus of the present embodiment.
As shown in FIG. 1, the printer 1 is schematically configured by a recording head 2, a microwave head 50, a carriage 4, a guide member 5, a paper feed roller 21, and a housing 40.
The recording head 2 has a function of printing on paper (recording paper) 10 as a material to be dried.
The carriage 4 can carry the ink cartridge 11. The carriage 4 is connected to a timing belt 8 that spans between a drive pulley 6 and an idle pulley 7.
The driving pulley 6 is joined to the rotating shaft of the pulse motor 9, and the carriage 4 can move the paper 10 in the main scanning direction, which is the width direction, by driving the pulse motor 9.
The recording head 2 attached to the surface of the carriage 4 facing the paper 10 is a type of ejection head that ejects liquid ink. An ink cartridge 11 is mounted on the carriage 4.
The guide member 5 has a function capable of moving the carriage 4 and the microwave head 50.
The paper feed roller 21 has a function capable of feeding the paper 10 in a predetermined direction. Further, the printer 1 includes a paper feed motor 39 that rotates the paper feed roller 21 to feed the paper 10 in the main scanning direction.

FIG. 2 is a schematic diagram showing the configuration of the printer. In addition, the figure has shown the state seen from the direction of the arrow of FIG.
As shown in FIG. 2, the microwave head 50 as a microwave radiation | emission part is arrange | positioned so that the paper 10 may be pinched | interposed. The microwave head 50 includes an upper head 51 disposed on the upper side of the paper 10 and a lower head 52 disposed on the lower side of the paper 10, and the microwave head 50 is interposed between the upper head 51 and the lower head 52. Paper 10 is arranged. The microwave head 50 is disposed beside the recording head 2 and is configured such that the recording head 2 and the microwave head 50 move simultaneously (in this case, in the left-right direction).

(Droplet dryer)
FIG. 3 is a block diagram showing an electrical configuration of the droplet drying apparatus.
As shown in FIG. 3, a droplet drying apparatus 500 is an embodiment of a drying apparatus according to the present invention, and an oscillator 100 as a microwave generation unit that oscillates a microwave 100a, and amplifies the microwave 100a. An amplifier 120, a control unit 36 for controlling the amplifier 120 by obtaining the reflectance from the reflection intensity of the reflected wave 100b, a power monitor 560 as a detection unit, a circulator 570 for limiting the direction of signal flow, and a microwave head 50 is roughly constituted. In the droplet drying apparatus 500, the microwave 100 a introduced into the circulator 570 is configured to be guided to the microwave head 50. Further, the reflected wave 100 b reflected from the paper 10 is configured to be guided to the power monitor 560. The reflected wave 100b guided to the power monitor 560 is guided to the control unit 36, and the control unit 36 is configured to control the amplifier 120 according to the degree of reflection intensity of the reflected wave 100b.

  The oscillator 100 is a diamond SAW oscillator to which a surface acoustic wave (SAW) that is a solid high-frequency oscillator is applied.

  The amplifier 120 can amplify the microwave 100a by amplifying the signal output from the oscillator 100 and outputting a 2.45 GHz band high-frequency signal. The amplifier 120 and the oscillator 100 are electrically connected.

  The power monitor 560 as a detection unit has a function of detecting the reflection intensity of the reflected wave 100b reflected from the paper 10, and the power monitor 560 as the detection unit and the circulator 570 are electrically connected. It is connected to the.

  The circulator 570 has a function of supplying the signal amplified by the amplifier 120 to the microwave head 50 and limiting the direction in which the signal flows. The circulator 570 and the microwave head 50 are electrically connected. It is connected to the.

  The microwave head 50 includes an upper head 51 and a lower head 52, and is disposed so as to be able to insert the paper 10 therebetween. The microwave head 50 includes a capacitor C that is a capacitor and an inductor L that is a coil. The capacitor C and the inductor L are arranged to form an LC resonator (in this case, the capacitor C, The inductor L is a series resonance circuit arranged in series, and may include a resistance component R).

4A and 4B are diagrams showing a schematic configuration of a droplet drying apparatus according to an embodiment of the present invention and showing distribution of an electric field and a magnetic field, wherein FIG. 4A is a perspective view and FIG. 4B is a cross-sectional view. FIG. 5 is a graph of the Bessel function for showing the electric field intensity distribution.
As shown in FIGS. 4A and 4B, the capacitor C is a parallel plate capacitor composed of a pair of circular electrode plates, and includes a first electrode plate 51A provided in the upper head 51, and a lower electrode 51A. A second electrode plate 52 </ b> A provided in the head 52. The first electrode plate 51A and the second electrode plate 52A are arranged such that the distance h between the opposing surfaces is λ / 2 (61.2 mm). Further, the radius r of the electrode plates 51A and 52A is set by X ₁ × v / ω (formula 1), and X ₁ is in the range of 2.3 to 2.5. Here, ω is the angular frequency of the microwave, f is the frequency of the microwave, v is the velocity of the microwave, and the angular frequency of the microwave is represented by ω = 2πf.

  The first electrode plate 51A and the circulator 570 are electrically connected, and the second electrode plate 52A and one terminal of the inductor L are electrically connected. The other terminal of the inductor L is electrically connected to the ground GND.

  Furthermore, the value of the capacitor C and the value of the inductor L can be arbitrarily selected and set, and the ink drying conditions can be determined.

When a microwave is applied to the capacitor C, the distribution of the electric field E and the magnetic field B is as shown in FIGS. 4 (a) and 4 (b). The internal electric field strength distribution is a first type Bessel function as shown in FIG. That is, the center of the electrode plate has the strongest strength, the strength gradually decreases toward the outer side (outer periphery) in the radial direction, and the number of places where the microwave does not occur (the place where the amplitude is 0 in the Bessel function graph). Or exist. Therefore, the electrode plate 51A, the radius r of 52A, first the set to such that the roots _{X 1} X coordinate (X = 2.405), a microwave energy (electric field strength) plates 51A, It can be made zero at the periphery of 52A. This eliminates the need for a shield to contain the microwave (to prevent leakage). For example, when the frequency is 2.45 GHz, the radius r of the electrode plates 51A and 52A is 4.7 cm according to the above equation 1. In addition, since there is no region where the electric field E becomes zero in the middle of the radial direction, the heating efficiency is improved.

Here, for example, plates 51A, if the radius r of 52A is a second root _{X 2} x coordinate (X = 5.52), the electrode plate 51A, are places where no microwave is generated in the radial direction of the 52A There will be a plurality of fields, and the distribution of the electric field E will be uneven. Therefore, the electrode plate 51A, it is preferable that the radius r of the 52A and the first X-coordinate of the root _{X 1.}

  When the paper 10 to be dried passes through the microwave head 50, it is heated by the action of the electric field generated between the electrode plates 51A and 52A, and the contained water rapidly evaporates and becomes high. Efficient drying will be performed.

FIG. 6 is a block diagram showing the electrical configuration of the printer.
As shown in FIG. 6, the printer 1 is schematically configured by a printer controller 31 and a print engine 32. The control unit 36 included in the printer controller 31 is configured to be able to perform control of the printer 1 and control of the droplet drying device 500 (see FIG. 3).

  The printer controller 31 generates an I / F (interface) 33, a RAM (Random Access Memory) 34, a ROM (Read Only Memory) 35, a control unit 36 including a CPU (Central Processing Unit), etc., and a clock signal. The oscillation circuit 37, the drive signal generation circuit 3, and the I / F (interface) 38 are provided.

  The I / F 33 can receive, for example, print data including any one or more of character code, graphic code, and image data from a host computer (not shown). The I / F 33 can output a busy signal, an acknowledge signal, and the like to the host computer.

  The RAM 34 has a function of storing various data and is used as a reception buffer, an intermediate buffer, an output buffer, a work memory (not shown), and the like. Print data from the host computer received by the I / F 33 is temporarily stored in the reception buffer. In the intermediate buffer, intermediate code data converted into an intermediate code by the control unit 36 is stored. Print data for each dot is developed in the output buffer.

  The ROM 35 has a function of storing various control routines executed by the control unit 36, font data and graphic functions, various procedures, and the like.

  The control unit 36 reads the print data in the reception buffer, converts it into an intermediate code, and stores this intermediate code data in the intermediate buffer. The control unit 36 has a function of analyzing the intermediate code data read from the intermediate buffer and developing the intermediate code data into print data by referring to the font data and graphic functions in the ROM 35. This print data is composed of, for example, 2-bit gradation information. The expanded print data is stored in the output buffer, and when print data corresponding to one line of the recording head 2 is obtained, the print data for one line is stored in the recording head 2 via the I / F 38. Serially transmitted. When one line of print data is transmitted from the output buffer, the contents of the intermediate buffer are erased and conversion to the next intermediate code is performed. The control unit 36 constitutes a part of the timing signal generating means. It has a function of supplying a latch signal and a channel signal to the recording head 2 through the I / F 38. These latch signals and channel signals have a function of defining the supply start timing of each pulse signal constituting the drive signal. Moreover, the control unit 36 has a function capable of controlling the droplet drying apparatus 500 shown in FIG.

The drive signal generation circuit 3 is a kind of drive signal generation means, generates a series of drive signals including a drive pulse constituted by a plurality of waveform elements, and supplies these drive signals to the recording head 2.
It has a function to do.

  The I / F (interface) 38 has a function of transmitting print data developed in dot pattern data, drive signals, and the like to the print engine 32.

  The print engine 32 includes an electric drive system of the recording head 2, a pulse motor 9 that moves the carriage 4 (see FIG. 1), a paper feed motor 39 that rotates the paper feed roller 21 (see FIG. 1), and the like. Yes.

  The electric drive system of the recording head 2 includes a shift register circuit including a first shift register 41 and a second shift register 42, a latch circuit including a first latch circuit 43 and a second latch circuit 44, a decoder 45, and control logic. 46, a level shifter 47, a switch circuit 48, and a piezoelectric vibrator 15 are provided.

  The printer 1 shown in FIG. 1 is equipped with a droplet drying device 500 according to this embodiment.

Next, the operation of the droplet drying apparatus will be described.
FIG. 7 is a flowchart showing an operation procedure of the droplet drying apparatus according to the present embodiment. In addition, it demonstrates for every step, referring FIG. 3, including the advancing direction of a microwave.

  In step S1 of FIG. 7, the emission of the microwave 100a is started. The oscillator 100 as the microwave generation unit generates a high-frequency signal and starts emitting the microwave 100a.

  In step S2, the microwave 100a is amplified. The microwave 100a is amplified by an amplifier 120 as an amplifier.

  In step S3, the microwave 100a is emitted. The microwave 100a output from the amplifier 120 is guided to a microwave head 50 as a microwave radiating unit via a circulator 570. Of the microwave 100a guided to the microwave head 50, the reflected wave 100b reflected by the impedance mismatch is transmitted to the other end of the circulator 570 to the power monitor 560 as a detection unit that detects the reflected wave 100b. Led. In general, when the reflected wave 100b returns to the amplifier 120, there is a possibility that the amplifier circuit may be destroyed. Therefore, a circulator 570 is often inserted as a protection circuit. The emitted microwave 100 a is a substantially plane wave, and is emitted from the upper head 51 constituting the microwave head 50 toward the lower head 52. The microwave 100 a is radiated from the front surface of the paper 10 inserted between the upper head 51 and the lower head 52 toward the back surface.

  In step S4, the moisture content of the paper 10 is detected and the ink is dried. When the paper 10 is wet, the impedance of the LC resonance circuit is at the output end of the microwave power supply unit at the oscillation frequency of the microwave source while the wet paper 10 is in the microwave head 50 as the microwave radiating unit. The element constants are set so as to be conjugate (matching) with the impedance. When the moisture content of the paper 10 existing between the capacitors C decreases (when the humidity is low), the LC resonance circuit (in this case, the series resonance circuit) is less likely to resonate, and the reflection intensity of the reflected wave 100b increases. This reflection intensity varies depending on the dielectric constant of the paper 10. Since the LC resonance circuit is set in advance so that impedance is matched when the paper 10 is wet, the dielectric constant of the paper 10 decreases as the paper 10 is dried and the amount of moisture in the paper 10 decreases. By detecting this reflection intensity, the dielectric constant of the paper 10 can be obtained, and the water content of the paper 10 can be calculated from the obtained dielectric constant.

  By this method, the time when the paper 10 is dried can be detected. Then, when the drying of the paper 10 is detected, the heating is finished, and the drying shortage can be reduced. Conversely, when the amount of water in the paper 10 increases (when the humidity is high), the LC resonance circuit starts to resonate, and the microwave 100a is radiated in a concentrated manner to efficiently dry the water. Further, when the moisture contained in the paper 10 or ink as droplets approaches a dry state, the output of the microwave 100a can be reduced to reduce wasteful power consumption. Furthermore, it is possible to suppress scorching of the paper 10 due to excessive heating and deterioration of the ink. The ink used here is for printing on paper 10 (including printing). For example, when printing in six colors, cyan, light cyan, magenta, light magenta, yellow, A material having a pigment such as black is used. In addition, it is convenient to select the conditions for drying if the correspondence data of the moisture content and the dielectric constant for each type of commonly used paper (printing paper) 10 is prepared in advance.

  In step S5, the reflection intensity of the reflected wave 100b is detected and the amplifier 120 is controlled. The intensity of the reflected wave 100b from the microwave head 50 serving as the microwave radiation unit is detected using a power monitor 560 serving as a detection unit. It is desirable that the detection operation for detecting the intensity of the reflected wave 100b is always performed during the operation of the printer 1 shown in FIG. By always performing this detection operation, a more accurate detection result can be obtained. Here, when the amount of water contained in the paper 10 decreases, the dielectric constant between the capacitors C changes, and the value of the capacitance changes. Then, the impedance changes and the intensity of the reflected wave 100b increases (this state is referred to as a mismatched state). Therefore, the dielectric constant of the paper 10 can be obtained by using the increase / decrease in the intensity of the reflected wave 100b. If the correspondence data between the moisture content and the dielectric constant for each type of paper 10 is prepared in advance, the moisture content of the paper 10 can be calculated from the obtained dielectric constant. By this method, the amount of moisture contained in the paper 10 is detected, and the control unit 36 controls the output of the amplifier 120 accordingly. The control unit 36 can increase the amplification factor of the amplifier 120 when the intensity of the reflected wave 100b is low, and conversely reduce the amplification factor of the amplifier 120 as the intensity of the reflected wave 100b increases.

  In step S6, the ink can be dried, and when the ink ejection from the recording head 2 shown in FIG. 1 is completed, the emission of the microwave 100a is stopped. The oscillation of the high frequency signal oscillated from the oscillator 100 as the microwave generation unit is stopped.

  By using a single microwave source, detection of the amount of water contained in the paper 10 and drying of the ink can be performed almost simultaneously. The detection of the amount of water contained in the paper 10 can be confirmed by a change in impedance accompanying a change in the dielectric constant of the capacitor, and can be performed by a change in the reflection intensity of the reflected wave 100b. Then, by detecting the amount of water contained in the paper 10, the output intensity of the microwave 100a can be controlled to an appropriate value, leading to shortening of drying time and power consumption.

According to the configuration of the droplet drying apparatus and the printer in the embodiment as described above, the following effects can be obtained.
Since the present embodiment includes the microwave head 50 that radiates the microwave 100 a to the paper 10, detecting the amount of moisture contained in the paper 10 by radiating the microwave 100 a to the paper 10 It is possible to provide a droplet drying apparatus 500 that can dry ink as droplets disposed on the substrate substantially simultaneously. In the droplet drying apparatus 500, the microwave head 50 is composed of a pair of circular electrode plates 51A and 52A, so that a uniform electric field distribution is obtained between the electrode plates 51A and 52A. In the present embodiment, the radius r of the electrode plates 51A and 52A of the microwave head 50 is set using the Bessel function described above, and as a result, the microwave can be contained in the microwave head 50 without using a shield. Can do. Thereby, it can produce using the conventional manufacturing method, and cost does not increase. Further, since the radius r of the electrode plates 51A and 52A is set appropriately, there is no portion where the electric field E becomes zero in the microwave head 50. Therefore, the drying efficiency can be improved by improving the energy density, and the time can be shortened. Can perform highly efficient drying.

  In addition, since the LC resonator (in this case, a series resonant circuit) is configured in the microwave head 50, the function as a heating antenna and the function as a detection element can be combined, and the device configuration is Can be simple. In particular, since the microwave head 50 also serves as a moisture amount detection sensor, the number of components added to the recording head 2 is minimized. For this reason, the restrictions on the design of the head portion are reduced. Further, compared to a case where a separate sensor is provided for detecting the amount of moisture, since the wiring to the sensing unit is reduced, the configuration can be simplified.

  In addition, since the process of radiating the microwave 100 a to the paper 10 is provided, the microwave 100 a is radiated to the paper 10 to detect the amount of moisture contained in the paper 10 and the liquid disposed on the paper 10. Since the drying of ink as droplets can be performed almost simultaneously, there is little blurring and the ink can be dried neatly. Moreover, since it can be dried in a short time, it is efficient. Furthermore, if the LC resonator that also functions as a detection element and a function as a heating antenna is oscillated, the amount of moisture contained in the paper 10 is detected and disposed on the paper 10. Since drying of ink as droplets can be performed substantially simultaneously, it is efficient.

  In addition, since the material to be dried is the paper 10, if the correspondence data of the moisture content and the dielectric constant is prepared in advance in the order of frequency of use, even if the quality of the paper 10 changes, it is arranged on the paper 10. The conditions for drying the droplets to be dried can be quickly selected, so that the droplets can be dried more quickly and high-speed printing can be realized.

  In addition, since a droplet drying device 500 that detects the amount of moisture contained in the paper 10 and dries ink as droplets disposed on the paper 10 is mounted, Even in the case of double-sided printing such as printing on the back side, it is possible to perform beautiful printing with less blur. In addition, since the detection of the amount of water contained in the paper 10 and the drying of the ink as droplets can be performed almost simultaneously, the printer 1 capable of realizing high-speed printing can be provided. Furthermore, since a microwave power source using a solid-state oscillation source such as a diamond SAW oscillator is used as the oscillator 100, power saving and high-efficiency excitation are possible, so that energy consumption can be suppressed. If energy consumption can be suppressed, it can also contribute to reduction of environmental load.

  In the above embodiment, the microwave head that constitutes the LC resonator using the parallel plate capacitor has been described. In the embodiment described below, a microwave head that constitutes an LC resonator using a cylindrical cavity resonator having a variable axial length will be described.

(Second Embodiment of Liquid Drying Device)
Next, a second embodiment of the liquid drying apparatus according to the present invention will be described. In the present embodiment, the same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted. Here, FIG. 8 is a diagram showing a schematic configuration of the microwave head of the droplet drying apparatus according to the present embodiment, where (a) is a sectional view along the axial direction, and (b) is a sectional view in the radial direction. It is. FIG. 9 is a diagram showing the energy density of the microwave head.
As shown in FIGS. 8A and 8B, the microwave head 60 of the droplet drying apparatus in the present embodiment constitutes a cylindrical cavity resonator 64 having a dipole antenna 63 used as a capacitor C therein. To do.

  The cylindrical cavity resonator 64 includes a pair of resonators 61 and 62 having a cylindrical shape, and has one opening surface 61a and one opening surface 62a facing each other in the longitudinal direction and arranged at a predetermined interval from each other. . Specifically, the resonator 61 is disposed in the upper head 51 shown in FIG. 2, and the resonator 62 is disposed in the lower head 52. The length h and the diameter d1 of the cylindrical cavity resonator 64 coincide with an integral multiple or a fraction of the half wavelength of the microwave. For example, the length h in the longitudinal direction is λ / 2, and the diameter d1 is λ /. 2 to λ / 8.

  In each of the resonators 61 and 62, columnar antennas 63A and 63B are provided that are aligned with the axis of the resonators 61 and 62 and extend perpendicular to the paper 10 passing direction. The dipole antenna 63 is constituted by the first antenna 63A for transmission disposed in the resonator 61 and the second antenna 63B for reception disposed in the resonator 62. Further, the resonators 61 and 62 and the antennas 63A and 63B are electrically separated from each other.

  The first antenna 63A and the circulator 570 are electrically connected, and the second antenna 63B and one terminal of the inductor L are electrically connected. The other terminal of the inductor L is electrically connected to the ground GND as in the above embodiment.

  In the present embodiment, for example, when the wavelength of the microwave is 2.45 GHz, the diameter d1 of each of the resonators 61 and 62 is λ / 8 (about 15.3 mm), and the longitudinal length h of the microwave head 60 is λ. / 2 (about 61.2 mm). Further, by setting the lengths of the antennas 63A and 63B to about 29 mm, the gap g between the first antenna 63A and the second antenna 63B is about 3 mm. Since this is a sufficiently short distance compared to the wavelength of the microwave, an effect that the leakage of the microwave hardly occurs can be obtained.

  When the paper 10 to be dried passes between the antennas 63A and 63B in the cylindrical cavity resonator 64 that excites a strong electric field in the thickness direction of the paper 10, the electric field generated in the cavity (FIG. 9). The water contained therein is rapidly evaporated and drying is performed efficiently. As shown in FIG. 9, the electric field is extremely strong between the antennas 63A and 63B of the cylindrical cavity resonator 64. Thereby, since the energy density of a microwave improves and the paper 10 can be heated up rapidly, heating efficiency can be raised more.

(Third embodiment of liquid drying apparatus)
Next, a third embodiment of the liquid drying apparatus according to the present invention will be described. In the present embodiment, the same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted. Here, FIG. 10 is a diagram showing a schematic configuration of the microwave head of the droplet drying apparatus according to the present embodiment, and is a cross-sectional view along the axial direction. FIG. 11 is a diagram showing the energy density of the microwave head.

The basic configuration of the microwave head 70 of the present embodiment described below is substantially the same as that of the second embodiment, but the shape of the dipole antenna is different from that of the second embodiment. Specifically, as shown in FIG. 10, the diameters d2 of the end portions 73a and 73b (opposite end portions) of the cylindrical antennas 73A and 73B constituting the dipole antenna 73 are reduced (d2 <d1). Is formed.
Thus, by narrowing the tip portions 73a and 73b of the antennas 73A and 73B, the electric field is strengthened, and a higher energy density can be obtained (see FIG. 11).

(Fourth embodiment of liquid drying apparatus)
Next, a fourth embodiment of the liquid drying apparatus according to the present invention will be described. In the present embodiment, the same components as those in the above embodiment are denoted by the same reference numerals and description thereof is omitted. Here, FIG. 12 is a diagram showing a schematic configuration of the microwave head of the droplet drying apparatus according to the present embodiment, where (a) is a sectional view along the axial direction, and (b) is a sectional view in the radial direction. It is. FIG. 13 is a diagram showing the energy density of the microwave head according to the present embodiment.

  In the liquid drying apparatus of the second and third embodiments, the axial direction of the cylindrical cavity resonator is perpendicular to the paper surface of the paper 10 (passing direction of the paper 10). This is different from the above-described embodiment in that the longitudinal direction of the mold cavity resonator is parallel to the paper surface.

  As shown in FIGS. 12A and 12B, the microwave head 80 of the droplet drying apparatus according to the present embodiment includes a pair of resonators 81 and 82, and a dipole antenna disposed in the resonator 81. 83 and a cylindrical cavity resonator 84 including a conductor 85 disposed in the resonator 82.

  As shown in FIG. 12 (b), the resonator 81 and the resonator 82 have a semicircular arc shape in cross section, and the openings 81b and 82b that are opened in the radial direction are opposed to each other and are arranged at a predetermined interval. That is, it has a cylindrical shape. Here, the resonator 81 is disposed in the upper head 51 shown in FIG. 2, and the resonator 82 is disposed in the lower head 52.

  The first and second cylindrical antennas 83A and 83B constituting the dipole antenna 83 are aligned with each other on the opening 81b side of the resonator 81, and the axial directions of the antennas 83A and 83B are paper. Are arranged so as to be parallel to the direction in which they pass, and are separated from each other by a predetermined distance.

  The conductor 85 is made of a conductive metal material and has a predetermined axial length and diameter. In the vicinity of the region s formed between the antennas 83A and 83B and in the vicinity of the center in the longitudinal direction of the resonator 82, the gap G with the antennas 83A and 83B is arranged to be about 3 mm. The conductor 85 may be connected to the resonator 82, but is separated from the antennas 83A and 83B. The conductor 85 in the present embodiment has a diameter d3 that is larger than the gap G between the antennas 83A and 83B.

  The first antenna 83A and the second antenna 83B and the circulator 570 are electrically connected, and the conductor 85 and one terminal of the inductor L are electrically connected. As described above, in this embodiment, the pair of antennas 83A and 83B are used for transmission, and the conductor 85 is used for reception, and discharge occurs between the antennas 83A and 83 and the conductor 85 (see FIG. 13). ). The paper 10 passes between the resonator 81 and the resonator 82, that is, between the pair of antennas 83A and 83B and the conductor 85.

  In the microwave head 80 of the present embodiment, for example, when the wavelength of the microwave is 2.45 GHz, the diameter d4 of the opening end in the axial direction is λ / 4 (about 30.6 mm), and the length of the cylindrical cavity resonator 84 is long. The direction length h is λ / 2 (about 61.2 mm). Further, the length of the antennas 83A and 83B is about 29 mm, and the gap g between the first antenna 83A and the second antenna 83B is about 3 mm. In order to prevent leakage of microwaves, the gap G between the antennas 83A and 83B and the conductor 85 is preferably about 3 mm. Therefore, the cylindrical cavity resonator 84 is designed to satisfy the gap G condition. The diameter d4 and the length of the conductor 85 are set.

  According to the present embodiment, since the cylindrical cavity resonator 84 is disposed on its side so that its axial direction is parallel to the paper surface of the paper 10, the microwave head 80 can be reduced in height. A conductor 85 is disposed in the vicinity of the region s between the antennas 83A and 83B so as to face both ends of the opposing antennas 83A and 83B. Therefore, as shown in FIG. 13, microwaves are generated between the antennas 83 </ b> A and 83 </ b> B and the conductor 85, and when the paper 10 passes between the antennas 83 </ b> A and 83 </ b> B and the conductor 85, Will be emitted.

  In this way, the location where the microwave energy is concentrated is not between the antennas 83A and 83B but between the antennas 83A and 83B and the conductor 85, so that the drying efficiency can be improved even when the cylindrical cavity resonator 84 is turned over. The axial length of each of the resonators 81 and 82 (longitudinal length h of the microwave head 80) can be shortened. Accordingly, the microwave head 80 (cylindrical cavity resonator 84) can be reduced in height and can be easily incorporated into a printer. Furthermore, since the degree of freedom in designing the entire apparatus is improved, it is possible to reduce the size.

  As described above, the present invention has been described with reference to preferred embodiments, but the present invention is not limited to the above-described embodiments, and includes modifications as described below, as long as the object of the present invention can be achieved. It can be set to any other specific structure and shape.

(Modification 1)
In the above-described embodiment, the series resonance circuit in which the capacitor C and the inductor L are arranged in series is adopted in the droplet drying device 500, but the present invention is not limited to this. For example, as in a droplet drying device 501 shown in FIG. 14, a configuration using a parallel resonance circuit (which may include a resistance component R) in which a capacitor C and an inductor L are arranged in parallel may be adopted. Even in this case, since the upper head 51 and the lower head 52 constituting the microwave head 50 are configured so as to sandwich the paper 10, the same effects as in the present embodiment can be obtained.

(Modification 2)
In the above-described embodiment, the configuration in which one microwave head 50 is mounted on the printer 1 is not limited thereto. For example, a configuration in which a plurality of microwave heads 50 are mounted may be employed. In this way, if a large number of microwave heads 50 are mounted on the printer 1, it can be expected that the time from the detection of the amount of water to the drying of the ink will be faster.

(Modification 3)
In the above-described embodiment, the droplet drying apparatus 500 equipped with the microwave head 50 is employed in the printer 1, but the present invention is not limited to this. For example, the present invention may be adopted in a printing apparatus other than the printer 1 and other various apparatuses necessary for drying the paper 10. If it does in this way, since it can be used in various fields, the use can be expanded.

FIG. 3 is a perspective view illustrating a configuration of a printer equipped with the droplet drying apparatus according to the embodiment. FIG. 2 is a schematic diagram illustrating a configuration of a printer. The block diagram which shows the electric constitution of a droplet drying apparatus. 1A and 1B are diagrams showing a schematic configuration of a droplet drying apparatus according to one embodiment and showing distribution of an electric field and a magnetic field, in which FIG. 1A is a perspective view, and FIG. The figure which shows a Bessel function. FIG. 2 is a block diagram illustrating an electrical configuration of the printer. The flowchart which shows the operation | movement procedure of a droplet drying apparatus. It is a figure which shows schematic structure of the microwave head of the droplet drying apparatus which concerns on 2nd Embodiment, Comprising: (a) is sectional drawing which follows an axial direction, (b) is sectional drawing which follows a radial direction. The figure which shows the electric field and magnetic field distribution of the droplet drying apparatus which concerns on 2nd Embodiment. It is a figure which shows schematic structure of the microwave head of the droplet drying apparatus which concerns on 3rd Embodiment, Comprising: Sectional drawing which follows an axial direction. The figure which shows distribution of the electric field and magnetic field of the droplet drying apparatus which concern on 3rd Embodiment. It is a figure which shows schematic structure of the microwave head of the droplet drying apparatus which concerns on 4th Embodiment, (a) is sectional drawing which follows an axial direction, (b) is sectional drawing which follows a radial direction. The figure which shows distribution of the electric field and magnetic field of the droplet drying apparatus which concerns on 4th Embodiment. The block diagram which shows the electrical constitution of the droplet drying apparatus which concerns on the modification 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Printer, 2 ... Recording head as droplet discharge head, 10 ... Paper as to-be-dried body, 36 ... Control part, 50 ... Microwave head as a microwave radiation | emission part, 51 ... Upper head, 52 ... Lower head DESCRIPTION OF SYMBOLS 100 ... Oscillator as a microwave generation part, 100a ... Microwave, 100b ... Reflected wave, 101 ... Printer, 102 ... Printer, 120 ... Amplifier, 500 ... Droplet drying apparatus, 501 ... Droplet drying apparatus, 560 ... Detection power monitor as part, 570 ... circulators, X 1 _... first zero point, X 2 _... second zero point, 60 ... microwave head in the second embodiment, 61 ... resonator, 62 ... resonator, 63A ... first antenna, 63B ... second antenna, 63 ... dipole antenna, 64 ... cylindrical cavity resonator, 70 ... microwave head of the third embodiment, 73A ... first 1 antenna 73B second antenna 73a tip 73b tip 73 dipole antenna 80 microwave head according to the fourth embodiment 81 resonator 81 82 resonator 81b 82b ... Open surface, 83A ... first antenna, 83B ... second antenna, 83 ... dipole antenna, 85 ... conductor.

Claims (10)

In a drying apparatus for drying a body to be dried,
The microwave radiating unit that radiates microwaves to the object to be dried includes a pair of electrode plates arranged in parallel,
The radius r of the pair of electrode plates is X ₁ × v / ω,
A drying apparatus in which the object to be dried passes between the pair of electrode plates (provided that 2.3 <X ₁ <2.5, the angular frequency of the microwave: ω = 2πf, the frequency of the microwave : F, speed of the microwave: v.)   The drying apparatus according to claim 1, wherein the distance between the inner surfaces of the pair of electrode plates is substantially half of the wavelength of the microwave. In a drying apparatus for drying a body to be dried,
The microwave radiating portion that radiates microwaves to the object to be dried is composed of a pair of columnar antennas that are spaced apart with their axes aligned.
The drying apparatus, wherein the object to be dried passes between the antennas in a direction perpendicular to the axis. In a drying apparatus for drying a body to be dried,
The microwave radiating part that radiates microwaves to the object to be dried is composed of a pair of columnar antennas that are arranged apart from each other with the axes aligned, and a conductor that is arranged in the vicinity of the antennas,
The drying apparatus is characterized in that the object to be dried passes between the pair of antennas and the conductor in a direction parallel to the axis.   5. The drying apparatus according to claim 3, wherein a length and an aperture diameter of the microwave radiating unit coincide with an integral multiple or a fraction of an integer of a half wavelength of the microwave.   The drying apparatus according to any one of claims 3 to 5, wherein the pair of antennas have the same length.   The drying device according to any one of claims 3 to 6, wherein tip portions of the pair of antennas facing each other are reduced in diameter. A microwave power supply unit for supplying the microwave to the microwave radiation unit;
The microwave power supply unit includes a reflected wave detection unit that detects a reflected wave according to a dry state of the object to be dried, an amplification circuit that amplifies the microwave, and the amplification circuit based on an output of the reflected wave detection unit The drying apparatus according to claim 1, further comprising: a control unit that controls the apparatus. An inductor connected to the microwave radiating unit;
The complex impedance of the microwave radiating unit when the object to be dried contains moisture and the complex impedance obtained by synthesizing the impedance of the inductor are conjugate with the complex impedance at the output end of the microwave radiating unit. The drying apparatus according to any one of claims 1 to 8, wherein: A liquid droplet ejection head for ejecting liquid droplets onto a body to be dried;
A printer comprising: the drying device according to claim 1.

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