JP2004294488A - Fixing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify the assembly of a coil for induction heating and to facilitate the handling thereof. <P>SOLUTION: The coil for induction heating which is housed inside a heating roller is constituted of a plurality of coil units, and a plurality of coil units are constituted to be separated to a 1st coil positioned nearly in the center of carried paper and 2nd coils arranged at both sides of the 1st coil in a state where they are housed in the heating roller. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fixing device that is mounted on an image forming apparatus such as a copying machine or a printer and fixes a developer image on paper.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an image forming apparatus using digital technology, for example, an electronic copying machine, has a fixing device for fixing a developer image on a sheet by heating under pressure. For example, in an electronic copying machine, a document table on which a document is placed is exposed, and light reflected from the document is guided to a photoelectric conversion element, for example, a CCD (charge coupled device). The CCD outputs an image signal corresponding to the image of the document. The photosensitive drum is irradiated with a laser beam corresponding to the image signal to form an electrostatic latent image on the peripheral surface of the photosensitive drum. This electrostatic latent image is visualized by the adhesion of a developer (toner). A sheet is sent to the photosensitive drum in synchronization with the rotation of the photosensitive drum, and a visible image (developer image) on the photosensitive drum is transferred to the sheet. The sheet on which the developer image has been transferred is sent to a fixing device.
[0003]
The fixing device includes a heating roller, and a pressure roller that rotates together with the heating roller while being in contact with the heating roller in a pressurized state. The heat fixes the developer image on the paper.
[0004]
As a heat source of the heating roller of the fixing device, there is induction heating. In this method, a coil is housed in a heating roller, a capacitor is connected to the coil to form a resonance circuit, and the resonance circuit is excited at one frequency for one resonance circuit, so that a high-frequency current is applied to the coil. Then, a high-frequency magnetic field is generated from the coil, an eddy current is generated in the heating roller by the high-frequency magnetic field, and the heating roller self-heats by Joule heat generated by the eddy current.
[0005]
In recent years, shortening of warm-up has become a technical issue as an energy-saving technology, but as a countermeasure, the thickness of a heating roller has been reduced.
[0006]
By the way, various paper sizes are used in an electronic copying machine. Therefore, in the fixing device, when narrow paper is continuously passed, the outside of the paper size on the heating roller is not deprived of heat by the paper and becomes higher than the temperature within the paper width, When a wide sheet is passed after a narrow sheet, fixing failure due to high-temperature offset occurs. Such a phenomenon becomes more conspicuous as the thickness of the heating roller is smaller (as the heat capacity is smaller).
[0007]
Therefore, a method has been proposed in which a coil for induction heating is divided into a plurality of portions and, for example, the central portion and the end portion of the heating roller are separately energized and heated.
[0008]
However, in order to produce such an induction heating coil, the bobbin is also divided, and a wire (such as a stranded wire) used for the coil is wound around each bobbin, so that it takes time and effort. Further, when the bobbin is disconnected for some reason, it is necessary to unwind and rewind all the windings in order to reuse the bobbin.
[0009]
[Problems to be solved by the invention]
As described above, in a fixing device using a coil for induction heating, it is troublesome and time-consuming to make the induction heating coil because the bobbin is divided and the wire used for the coil is wound around each bobbin. Further, when the wire is broken for some reason, it is necessary to unwind and rewind all the windings, and there is a problem that handling is difficult.
[0010]
Therefore, an object of the present invention is to provide a fixing device using an induction heating coil that can simplify the assembly of the induction heating coil and facilitate the handling.
[0011]
[Means for Solving the Problems]
According to the present invention, in a fixing device having a heating member that generates heat by eddy current due to a change in a magnetic field generated by an induction heating coil and fixing a developing material on a sheet, a plurality of coil units having a predetermined number of coils are provided. A fixing device is provided in which the coils are arranged and housed inside the heating member, and the coils of the respective coil units are connected as induction heating coils.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows an internal configuration of a composite electronic copying machine as an image forming apparatus. First, a transparent platen (glass plate) 2 for placing a document is provided on the upper surface of the main body 1, and the exposure lamp 5 provided on the carriage 4 is turned on, so that the platen 2 is placed on the platen 2. The placed document D is exposed.
[0013]
The reflected light from the document D due to the exposure is projected onto a photoelectric conversion element, for example, a CCD (charge coupled device) 10 to output an image signal. The image signal output from the CCD 10 is converted into a digital signal, and the digital signal is appropriately processed and then supplied to the laser unit 27. The laser unit 27 emits a laser beam B according to an input signal.
[0014]
A control panel (not shown) for setting operating conditions is provided on the upper surface of the main body 1 at a position not covered by the automatic document feeder 40. The control panel includes a touch panel type liquid crystal display unit, numeric keys for numeric input, a copy key, and the like.
On the other hand, a photosensitive drum 20 is rotatably provided at a substantially central portion in the main body 1. Around the photosensitive drum 20, a charging device 21, a developing unit 22, a transfer device 23, a peeling device 24, a cleaner 25, and a static eliminator 26 are sequentially disposed, and the photosensitive drum 20 is formed by a known process method. A toner image is formed thereon, the toner image is transferred onto the sheet, and the toner on the sheet is heated and pressed and fixed by a fixing device 100 described later.
[0015]
FIG. 2 shows a schematic configuration of the fixing device 100.
In FIG. 2, the fixing device 100 includes a heating roller 101 and a pressure roller 102 at positions vertically sandwiching the conveyance path of the copy sheet S. The pressure roller 102 is in pressure contact with the peripheral surface of the heating roller 101 by a pressure mechanism (not shown). The contact portions of the rollers 101 and 102 have a constant nip width.
[0016]
The heating roller 101 is formed by forming a conductive material, for example, iron into a cylindrical shape, and coating the outer peripheral surface of the iron with, for example, a fluororesin such as tetrafluoroethylene resin. The heating roller 101 is driven to rotate rightward in the figure by a drive motor (not shown). The pressure roller 102 rotates to the left in the drawing in response to the rotation of the heating roller 101. When the copy sheet S passes through the contact portion between the heating roller 101 and the pressure roller 102 and the copy sheet receives heat from the overheating roller 101, the developer image T on the copy sheet S is fixed on the copy sheet S. Is done.
[0017]
Around the heating roller 101, a peeling claw 103 for peeling the copy sheet S from the heating roller 101, a cleaning member 104 for removing toner and paper debris remaining on the heating roller 101, An application roller 105 for applying a release agent to the surface is provided.
[0018]
Although described later in detail, a plurality of coil units 110 for induction heating are housed inside the heating roller 101. The plurality of coil units 110 are supplied with high-frequency power by a circuit described later, and generate a high-frequency magnetic field for induction heating. When this high-frequency magnetic field is generated, an eddy current is generated in the heating roller 101, and the heating roller 101 self-heats by Joule heat due to the eddy current.
[0019]
Note that the heating roller 101 may be in the form of a belt, in other words, any heating member may be used as long as it can heat toner on paper.
[0020]
FIG. 3 shows a control circuit of the composite electronic copying machine. That is, the scan CPU 70, the control panel CPU 80, and the print CPU 90 are connected to the main CPU 50.
The main CPU 50 controls the scan CPU 70, the control panel CPU 80, and the print CPU 90, and controls a copy mode according to an operation of a copy key, and responds to an image input to the network interface 59. A printer mode control unit and a facsimile mode control unit in response to image reception by the facsimile transmission / reception unit 60 are provided.
[0021]
The main CPU 50 includes a ROM 51 for storing a control program, a RAM 52 for storing data, a pixel counter 53, an image processing unit 55, a page memory controller 56, a hard disk unit 58, a net interface 59, and a FAX transmitting / receiving unit 60. It is connected.
[0022]
The page memory controller 56 controls writing and reading of image data to and from the page memory 57. Further, the image processing unit 55, the page memory controller 56, the page memory 57, the hard disk unit 58, the net interface 59, and the FAX transmitting / receiving unit 60 are mutually connected by the image data bus 61. .
[0023]
The net interface 59 functions as an input unit for a printer mode to which an image (image data) transmitted from an external device is input. The network interface 59 is connected to a communication network 201 such as a LAN or the Internet, and external devices such as a plurality of personal computers 202 are connected to the communication network 201. These personal computers 202 include a controller 203, a display 204, an operation unit 205, and the like.
[0024]
The FAX transmitting / receiving unit 60 is connected to a telephone line 210 and functions as a facsimile mode receiving unit that receives an image (image data) transmitted by facsimile via the telephone line 210.
[0025]
The scan CPU 70 includes a ROM 71 for storing a control program, a RAM 72 for storing data, a signal processing unit 73 for processing the output of the CCD 10 and supplying it to the image data bus 61, a CCD driver 74, a scan motor driver 75, and an exposure lamp 5. , An automatic document feeder 40, a plurality of document sensors 11, and the like.
[0026]
The CCD driver 74 drives the CCD 10. The scan motor driver 75 drives a scan motor 76 for driving the carriage. The automatic document feeder 40 has a document D set on a tray 41 and a document sensor 43 for detecting its size.
[0027]
The control panel CPU 80 is connected to a touch panel type liquid crystal display unit 14, a numeric keypad 15, an all reset key 16, a copy key 17, and a stop key 18 of the control panel.
[0028]
The print CPU 90 is connected to a ROM 91 for storing a control program, a RAM 92 for storing data, a print engine 93, a paper transport unit 94, a process unit 95, and a fixing device 100. The print engine 93 includes the laser unit 27 and its drive circuit. The paper transport unit 94 includes a paper transport mechanism extending from the paper feed cassette 30 to the tray 38 and a drive circuit thereof. The process unit 95 includes the photosensitive drum 20 and a peripheral portion thereof.
[0029]
A print unit for printing the image processed by the image processing unit 55 on a sheet P is mainly composed of the print CPU 90 and its peripheral configuration.
[0030]
FIG. 4 shows an electric circuit of the fixing device 100.
[0031]
The coil in the heating roller 101 has a coil 111 composed of a plurality of coil units 110. For example, in the example shown in FIG. 4, the coil 111 is divided into three coils 111a, 111b, and 111c. In the example shown in FIG. 4, the coil 111a is located at the center of the heating roller 101. The coils 111b and 111c are located on both sides of the heating roller 101 with the coil 111a interposed therebetween. These coils 111a, 111b, 111c are connected to a high frequency generation circuit 120.
[0032]
A temperature sensor 112 is provided at the center of the heating roller 101. The temperature sensor 112 detects the temperature at the center of the heating roller 101. A temperature sensor 113 is provided at one end of the heating roller 101. The temperature sensor 113 detects the temperature of one end of the heating roller 101. These temperature sensors 112 and 113 are connected to the print CPU 90 together with a drive unit 160 for driving the heating roller 101 to rotate.
[0033]
The print CPU 90 has a function of controlling the drive unit 160, an operation of a later-described first resonance circuit (output power P1) having the coil 111a as a component, and a later-described second feature having the coils 111b and 111c as a component. It has a function of issuing a P1 / P2 switching signal for designating the operation of the resonance circuit (output power P2), and a function of controlling the output power of each resonance circuit and the temperature detected by the temperature sensors 112 and 113.
[0034]
The high-frequency generation circuit 120 generates high-frequency power for generating a high-frequency magnetic field, and includes a rectifier circuit 121 and a switching circuit 122 connected to an output terminal of the rectifier circuit 121. The rectifier circuit 121 rectifies the AC voltage of the commercial AC power supply 130. In the switching circuit 122, a first resonance circuit is formed by the coil 111a, and a second resonance circuit is formed by the coils 111b and 111c. Further, the first resonance circuit and the second resonance circuit are selectively excited by a switching element (for example, a transistor such as an FET) (not shown) provided in the switching circuit 122.
[0035]
The first resonance circuit has a resonance frequency f1 determined by the inductance of the coil 111a, the capacitance of a capacitor (not shown) in the switching circuit 122, and the like. The second resonance circuit has a resonance frequency f2 determined by the inductance of the coils 111b and 111c, the capacitance of a capacitor (not shown) in the switching circuit 122, and the like.
[0036]
The switching circuit 122 is turned on and off by the controller 140 in accordance with a P1 / P2 switching signal from the print CPU 90. The controller 140 includes an oscillation circuit 141 and a CPU 142. The oscillation circuit 141 issues a drive signal of a predetermined frequency to the switching circuit 122. The CPU 142 controls the oscillation frequency (frequency of the drive signal) of the oscillation circuit 141. The CPU 142 has, for example, the following means (1) and (2) as main functions.
[0037]
(1) When the operation of the first resonance circuit (using only the coil 111a) is specified by the P1 / P2 switching signal from the print CPU 90, the CPU 142 sets the first resonance circuit to a plurality of signals near the resonance frequency f1. (F1-Δf), (f1 + Δf).
[0038]
(2) When the operations of the first and second resonance circuits (use of all the coils 111a, 111b, 111c) are specified by the P1 / P2 switching signal from the print CPU 90, the CPU 142 performs the first and second resonance circuits. There is a control means for sequentially exciting the two-resonance circuit at a plurality of frequencies near the respective resonance frequencies f1 and f2, for example, (f1−Δf), (f1 + Δf), (f2−Δf), (f2 + Δf). .
[0039]
Next, the operation of the electric circuit of the fixing device 100 configured as described above will be described.
When a driving signal having the same frequency (or a frequency close to the resonance frequency) as the resonance frequency f1 of the first resonance circuit is generated from the oscillation circuit 141, the switching signal 122 is turned on / off by the driving signal, and the first resonance circuit is turned on. Get excited. By this excitation, a high-frequency magnetic field is generated from the coil 111a, and the high-frequency magnetic field generates an eddy current in the axial central portion of the heating roller 101, and the axial central portion of the heating roller 101 self-heats by Joule heat due to the eddy current. .
[0040]
When a drive signal having the same frequency (or a frequency close to) the resonance frequency f2 of the second resonance circuit is generated from the oscillation circuit 141, the switching signal 122 is turned on and off by the drive signal, and the second resonance circuit is turned on. Get excited. Due to this excitation, high-frequency magnetic fields are generated from the coils 111b and 111c, and the high-frequency magnetic fields generate eddy currents on both sides of the heating roller 101 in the axial direction. I do.
[0041]
FIG. 5 shows the relationship between the output power P1 of the first resonance circuit and the frequency for exciting the first resonance circuit, and the relationship between the output power P2 of the second resonance circuit and the frequency for exciting the second resonance circuit. Is shown.
[0042]
As shown in FIG. 5, the output power P1 of the first resonance circuit has a peak level when excited at the same frequency as the resonance frequency f1 of the first resonance circuit, and the excited frequency is separated from the resonance frequency f1. , The pattern gradually decreases like a mountain.
[0043]
Similarly, when the output power P2 of the second resonance circuit is excited at the same frequency as the resonance frequency f2 of the second resonance circuit, the output power P2 has a peak level, and becomes higher as the excited frequency becomes farther from the resonance frequency f2. The pattern gradually decreases.
[0044]
When fixing a large-sized sheet S, both the first and second resonance circuits are excited, and high-frequency magnetic fields are emitted from all the coils 111a, 111b, and 111c. An eddy current is generated in the entire heating roller 101 by the high frequency magnetic field, and the entire heating roller 101 self-heats by Joule heat generated by the eddy current. In this case, drive signals having two frequencies (f1−Δf) and (f1 + Δf) separated by a predetermined value Δf up and down about the resonance frequency f1 of the first resonance circuit are sequentially output from the oscillation circuit 141, and subsequently, A drive signal having two frequencies (f2−Δf) and (f2 + Δf) vertically separated by a predetermined value Δf around the resonance frequency f2 of the second resonance circuit is sequentially output from the oscillation circuit 141.
[0045]
With these drive signals, the first resonance circuit is sequentially excited at two frequencies (f1−Δf) and (f1 + Δf) sandwiching the resonance frequency f1, and subsequently, the second resonance circuit is excited at two frequencies sandwiching the resonance frequency f2. Excited sequentially at (f2−Δf), (f2 + Δf). The excitation for each frequency is repeated.
[0046]
As shown in FIG. 5, the output power P1 of the coil 111a in the first resonance circuit becomes a value P1a slightly lower than the peak level P1c at the time of excitation at the frequency (f1−Δf), and is excited at the frequency (f1 + Δf). At this time, the value P1b is slightly lower than the peak level P1c.
[0047]
The output power P2 of the coils 111b and 111c in the second resonance circuit becomes a value P2a slightly lower than the peak level P2c at the time of excitation at the frequency (f2−Δf), and also at the time of excitation at the frequency (f2 + Δf). Is slightly lower than the value P2b.
[0048]
FIG. 6 shows a configuration of the coil unit 110. The coil unit 110 includes a coil bobbin 110A around which an electric wire serving as a coil 111 is wound around the periphery.
[0049]
FIG. 7 shows a basic configuration of a holding member 110B for holding the coil bobbin 110A.
[0050]
FIG. 8 shows a state where the coil unit 110 is held by the holding member 110B, and is constituted by a plurality of coil units 110 such as six or twelve.
[0051]
FIG. 9 shows a configuration example using twelve induction heating coil units 110 housed inside the heating roller 101 according to the first embodiment. In the configuration example of FIG. 9, the coil 111b shown in FIG. 4 is formed on the holding member 110B with three coil units 110 from the left in the figure, and the coil 111a shown in FIG. The following three coil units 110 constitute the coil 111c shown in FIG.
[0052]
Each coil unit 110 can be connected to form a plurality of coils (111a, 111b, 111c) as described above. That is, the coils of each coil unit 110 are connected in series or in parallel to constitute the above-described coils 111a, 111b, and 111c.
[0053]
The coil unit 110 of the present invention is, for example, a single wire made of copper and having a wire diameter of about 1 mm or less and about 0.5 mm as a coil, and is driven at a high frequency of 2 MHz.
[0054]
As described above, according to the first embodiment, the induction heating coil housed inside the heating roller 101 is composed of a plurality of coil units, thereby simplifying the configuration and facilitating the assembly. Can be.
[0055]
Next, a second embodiment will be described.
[0056]
10 and 11 show coil units having different coil bobbin widths. That is, the coil bobbin width used in the coil unit 210 shown in FIG. 10 is smaller than the coil bobbin width used in the coil unit 220 shown in FIG.
[0057]
Further, the number of wire turns of the coil unit 210 and the number of wire turns of the coil unit 220 are different.
[0058]
In the first embodiment shown in FIG. 9, the same coil unit 110 is used, but in the second embodiment, different coil units 210 and 220 are used.
[0059]
In the second embodiment, for example, the total length of the induction heating coil when the heating width is changed can be easily set by combining the coil units 210 and 220.
[0060]
In the second embodiment, for example, the coil units 210 and 220 make it easy to combine coils having two types of turns.
[0061]
Further, by combining the coils having two types of turns using the coil units 210 and 220, the temperature distribution can be made symmetric in the axial direction.
[0062]
In the above-described second embodiment, two types of coil units are used, but two or more types of coil bobbin widths and the number of turns may be used.
[0063]
As described above, according to the second embodiment, by combining two or more types of coil units having different coil bobbin widths, it is possible to eliminate the complexity of assembly and to provide a coil for induction heating having a heating width of various characteristics. Can be configured.
[0064]
In addition, by combining two or more types of coil units having different numbers of turns, it is possible to eliminate the complexity of assembly and to configure a coil for induction heating having a heating width of various characteristics.
[0065]
Further, by combining two or more types of coil units having different numbers of windings, the coils for induction heating can be arranged symmetrically in the axial direction to make the temperature distribution symmetrical.
[0066]
Next, a third embodiment will be described.
[0067]
In the induction heating coil in which a plurality of coils are connected in parallel, the coils are wound coaxially with the heating roller 101, and the arrangement of the coils in parallel complicates the connection of the individual coils.
[0068]
Therefore, also in the third embodiment, as shown in FIG. 9, a coil for induction heating is configured using a plurality of coil units.
[0069]
FIG. 12 shows a configuration example using eight induction heating coil units 110 housed inside the heating roller 101 according to the third embodiment. That is, the induction heating coil of the third embodiment is disposed at the both ends of the first coil located substantially at the center of the sheet conveyed to the heating roller 101 while being housed in the heating roller 101. And a second coil.
[0070]
In the example of FIG. 12, the first coil includes four coil units 110, and the second coil includes two coil units 110 on the left end in the figure and two coil units 110 on the right end in the figure. It is configured.
[0071]
In the third embodiment, the number of coil units of the first coil is four and the number of second coil units is four, which is the same. As a result, the excitation circuit of the high-frequency generation circuit 120 that drives these coils can be configured with the same circuit, and the circuit can be simplified and configured at low cost.
[0072]
As shown in FIG. 4, the first coil corresponds to the coil 111a, the roller temperature is detected by the temperature sensor 112, the second coil corresponds to the coils 111b and 111c, and the roller temperature is detected by the temperature sensor 113. Is detected, and the temperature is controlled to be constant.
[0073]
In the energization control of the divided dielectric heating coils as described above, the lower one of the temperatures detected by the temperature sensors 112 and 113 corresponding to the first coil and the second coil is controlled to a predetermined fixing temperature. Has become.
[0074]
At that time, the distribution of energization is as follows.
[0075]
When the output of the temperature sensor 112 is low, the output ratio of the first coil to the second coil is set to 80:20 to 90:10.
[0076]
When the output of the temperature sensor 113 is low, the output ratio of the first coil to the second coil is set to 40:60 to 30:70.
[0077]
As described above, according to the third embodiment, by setting the number of coil units constituting the first coil and the number of coil units constituting the second coil to be the same, the excitation for driving these coils is performed. The circuit can be simplified with the same circuit configuration, and the circuit can be configured at low cost.
[0078]
Next, a fourth embodiment will be described.
[0079]
FIG. 13 shows a configuration example using ten induction heating coil units 110 housed inside the heating roller 101 according to the fourth embodiment. In other words, the induction heating coil of the fourth embodiment is housed in the heating roller 101, and the first coil is located at substantially the center of the conveyed sheet, and the second coil is disposed at both ends thereof. And a coil.
[0080]
In the example of FIG. 13, the first coil includes four coil units 110, and the second coil includes three coil units 110 on the left end side in the figure and three coil units 110 on the right end side in the figure. It is configured.
[0081]
In the fourth embodiment, the number of coil units of the first coil is four and the number of second coil units is six.
[0082]
Here, as described in the third embodiment, in the induction heating coil in which a plurality of coils (coil units) are connected in parallel, the first coil and the second coil are energized at the same time. It is necessary that the potential difference be the same and be on the common potential side.
[0083]
That is, when the number of coil units of the first coil is an odd number, one of them does not become the common potential. Therefore, the number of the first coils needs to be an even number. Further, the number of coil units of the second coil is not limited to an even number or an odd number, and the entire induction heating coil is constituted by an even number of coil units.
[0084]
As described above, according to the fourth embodiment, when configuring an induction heating coil in which a plurality of coils (coil units) are connected in parallel, the number of coil units is configured to be an even number. The common potential is secured by making the potential difference between the adjacent wires in the first coil and the second coil the same.
[0085]
The invention of the present application is not limited to the above embodiments, and various modifications can be made in the implementation stage without departing from the scope of the invention. In addition, the embodiments may be implemented in appropriate combinations as much as possible, in which case the combined effects can be obtained. Furthermore, the above embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some components are deleted from all the components shown in the embodiment, (at least one of) the problems described in the column of the problem to be solved by the invention can be solved, and the effect of the invention can be solved. In the case where (at least one of) the effects described in (1) is obtained, a configuration from which this component is deleted can be extracted as an invention.
[0086]
【The invention's effect】
As described above in detail, according to the present invention, it is possible to provide a fixing device using an induction heating coil which can simplify the assembly of the induction heating coil and facilitate the handling.
[Brief description of the drawings]
FIG. 1 is a diagram showing an internal configuration of a multifunction electronic copying machine as an image forming apparatus.
FIG. 2 is a diagram illustrating a schematic configuration of a fixing device.
FIG. 3 is a diagram showing a control circuit of the composite electronic copying machine.
FIG. 4 is a block diagram illustrating an electric circuit of the fixing device.
FIG. 5 is a diagram showing a relationship between output power P1 and frequency and a relationship between output power P2 and frequency.
FIG. 6 is a diagram showing a configuration of a coil unit.
FIG. 7 is a diagram showing a basic configuration of a holding member.
FIG. 8 is a diagram showing a state where the coil unit is held by a holding member.
FIG. 9 is a diagram showing a configuration example using a plurality of coil units according to the first embodiment.
FIG. 10 is a diagram showing coil units having different coil bobbin widths.
FIG. 11 is a diagram showing coil units having different coil bobbin widths.
FIG. 12 is a diagram showing a configuration example using a plurality of coil units according to a third embodiment.
FIG. 13 is a diagram showing a configuration example using a plurality of coil units according to a fourth embodiment.
[Explanation of symbols]
Reference numeral 50: main CPU, 90: printer CPU, 100: fixing device, 101: heating roller, 102: pressure roller, 110, 210, 220: coil unit, 111: coil, 112, 113: temperature sensor, 120: high frequency generation Circuit, 122: switching circuit, 140: controller, 141: oscillation circuit, 142: CPU, 160: drive unit.

Claims (8)

In a fixing device that has a heating member that generates heat by eddy current due to a change in a magnetic field generated by an induction heating coil and fixes a developer on paper,
A fixing device, wherein a plurality of coil units each having a predetermined number of coils are arranged and accommodated in the heating member, and the coils of each coil unit are connected as induction heating coils. In a fixing device that has a heating member that generates heat by eddy current due to a change in a magnetic field generated by an induction heating coil and fixes a developer on paper,
A plurality of coil units each having a predetermined number of coils are held by a holding member, arranged and housed inside the heating member, and are conveyed to the heating member while being housed inside the heating member. A plurality of the coil units located at substantially the center of the sheet are connected as a first induction heating coil, and a plurality of the coil units located at both ends thereof are used as a second induction heating coil. A fixing device characterized by being connected. In a fixing device that has a heating member that generates heat by eddy current due to a change in a magnetic field generated by an induction heating coil and fixes a developer on paper,
A plurality of types of coil units having a plurality of types of coil windings are arranged symmetrically in the direction perpendicular to the transport direction of the paper conveyed to the heating member inside the heating member by combining a plurality of types and a plurality of types. A fixing device wherein the coils of the respective coil units are connected as induction heating coils. In a fixing device that has a heating member that generates heat by eddy current due to a change in a magnetic field generated by an induction heating coil and fixes a developer on paper,
A plurality of first coil units having a first number of coils and a plurality of second coil units having a second number of coils, and the paper conveyed to the heating member inside the heating member; A fixing device, wherein the fixing unit is symmetrically arranged and accommodated in a direction perpendicular to the conveying direction of the fixing unit, and the coils of the respective coil units are connected as induction heating coils. In a fixing device that has a heating member that generates heat by eddy current due to a change in a magnetic field generated by an induction heating coil and fixes a developer on paper,
A plurality of coil units having a plurality of unit widths corresponding to a plurality of types of coil windings are combined in a plurality of unit widths, and inside the heating member, in the transport direction of the paper conveyed to the heating member. A fixing device, wherein the fixing units are symmetrically arranged and housed in a direction orthogonal to each other, and the coils of the respective coil units are connected as induction heating coils. In a fixing device that has a heating member that generates heat by eddy current due to a change in a magnetic field generated by an induction heating coil and fixes a developer on paper,
A first coil unit having a unit width corresponding to the first number of coil turns and a second coil unit having a unit width corresponding to the second number of coil turns correspond to the first and second coil numbers. A plurality of unit widths are combined and housed inside the heating member so as to be symmetrically arranged in a direction perpendicular to the conveying direction of the paper conveyed to the heating member, and the coils of each coil unit are induction heating coils. A fixing device characterized by being connected as follows. In a fixing device that has a heating member that generates heat by eddy current due to a change in a magnetic field generated by an induction heating coil and fixes a developer on paper,
A plurality of coil units each having a predetermined number of coils are held by a holding member, arranged and housed inside the heating member, and are conveyed to the heating member while being housed inside the heating member. A plurality of the coil units located at substantially the center of the sheet are connected as a first induction heating coil, and a plurality of the coil units located at both ends thereof are used as a second induction heating coil. A fixing device wherein the number of connected coil units connected as the first induction heating coil is equal to the number of coil units connected as the second induction heating coil. In a fixing device that has a heating member that generates heat by eddy current due to a change in a magnetic field generated by an induction heating coil and fixes a developer on paper,
A plurality of coil units each having a predetermined number of coils are held by a holding member, arranged and housed inside the heating member, and are conveyed to the heating member while being housed inside the heating member. A plurality of the coil units located at substantially the center of the sheet are connected as a first induction heating coil, and a plurality of the coil units located at both ends thereof are connected as a second induction heating coil. The number of coil units connected as the first induction heating coil is an even number.

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