JPH09160416A - Induction-heated roller device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To deal with various kinds of paper sizes and to stably feed paper sheets. SOLUTION: This device is provided with an induction-heated roller having a roller 6 with a jacket chamber filled with a heating medium. An induction- heating mechanism is constituted of at least two or more independent induction- heating mechanisms 11-1n which are arranged in the axial direction of the roller 6 and independently energized and the jacket chamber is constituted of at least two or more independent jacket chambers 101-10n which are arranged in the axial direction of the roller 6 in positions facing two or more induction- heating mechanisms 11-1n in the circumferential direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating roller device used in image forming apparatuses such as copiers, facsimiles and printers.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, a facsimile or a printer, a toner image is formed on a sheet by an image signal obtained by reading an original image or an image signal from the outside, and the toner image on the sheet is formed. It is fixed on the paper by a heat fixing device. In the heat fixing device, usually, two fixing rollers are pressed against each other by a pressing means such as a spring to heat the fixing roller by a fixing heater, and when the paper passes through a nip portion of the two fixing rollers, the toner on the paper is The image is fixed on the paper by heating with a fixing roller. Further, the surface temperature of the fixing roller is detected by a thermistor, and the control unit controls the energization of the fixing heater according to the detected temperature to control the surface temperature of the fixing roller to a constant temperature.

Japanese Patent Laid-Open No. 53-50844 discloses a winding wound around a core, a heat-resistant and heat-insulating layer which is divided into a plurality of pieces on the outer periphery of the winding, and the heat-resistant and heat-insulating layer. A heating roller having an induction heating layer for heating, wherein a heat-resistant heat insulating layer is arranged only at each end of the induction heating layer to bend the central portion of the heating roller in a concave shape, and a force is applied to spread the paper when the paper is conveyed. There is described a heating roller adapted to perform stable paper feeding. This heating roller is used as a fixing roller of a heat fixing device.

In Japanese Unexamined Patent Publication (Kokai) No. Hei2-12791, a jacket chamber in which a gas-liquid two-phase heat medium is uniformly enclosed in the axial direction of the roller is provided on the peripheral wall of the roller which is rotatably supported. A plurality of induction heating mechanisms are arranged inside in the axial direction, and an expansion / contraction mechanism for expanding or contracting the rollers in the radial direction is provided on the inner peripheral wall surface of the roller between the plurality of induction heating mechanisms. An induction heating roller is described which is used as a fixing roller of a heating and fixing device to correct the amount of deflection due to the pressure at the nip portion.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The heating roller described in Japanese Patent No. 844 includes a winding wound around a core, a heat-resistant heat insulating layer which is divided into a plurality of pieces around the outer circumference of the winding, and an induction heating layer which covers the heat-resistant heat insulating layer. A heat roller having a heat-resistant heat-insulating layer disposed only at each end of the induction heat-generating layer to bend the center of the heat roller in a concave shape, and a force for spreading the paper is applied when the paper is conveyed to stabilize the paper feeding. However, since the optimum amount of curving the central portion of the heating roller varies depending on the paper conditions such as the paper size, it cannot be applied to various paper sizes.

Further, in the induction heating roller described in the above-mentioned Japanese Patent Laid-Open No. 12791/1990, a jacket in which a peripheral wall of a roller which is rotatably supported is filled with a two-phase gas-liquid heat medium uniformly in the axial direction of the roller. A chamber is provided, a plurality of induction heating mechanisms are arranged inside the roller in the axial direction, and the roller is expanded or contracted in the radial direction on the inner peripheral wall surface of the roller between the plurality of induction heating mechanisms. Since the expansion / contraction mechanism is provided, even if an attempt is made to expand or contract the roller in the radial direction by a plurality of induction heating mechanisms arranged inside the roller in the axial direction, the jacket chamber is moved in the axial direction of the roller. Since it is uniform, the roller cannot be partially expanded or contracted, the deflection amount of the roller cannot be corrected sufficiently, and stable sheet feeding cannot be performed.

SUMMARY OF THE INVENTION An object of the present invention is to provide an induction heating roller device which can cope with various paper sizes, can improve paper feeding stability and can save energy.

[0008]

In order to achieve the above object, the invention according to claim 1 has a roller having a jacket chamber in which a heat medium is enclosed, and an induction heating for the roller provided inside the roller. In an induction heating roller device having an induction heating roller configured to be rotatable including an induction heating mechanism, the induction heating mechanism is arranged in an axial direction of the roller and is independently energized by at least two or more. The jacket chamber comprises an independent induction heating mechanism, and the jacket chamber comprises at least two or more independent jacket chambers arranged in the axial direction of the roller at positions circumferentially opposed to the two or more induction heating mechanisms. The roller partially expands and contracts to improve the paper feeding stability.

According to a second aspect of the present invention, in the induction heating roller device according to the first aspect, there is provided means for varying the amount of electricity supplied independently to the two or more independent induction heating mechanisms. The heat generation distribution and the uneven shape of the roller surface can be arbitrarily changed.

[0010] The third aspect of the present invention is the first or second aspect.
In the induction heating roller device described above, a sheet size detecting unit that detects the size of the sheet on which the toner image is to be fixed, and a sheet size that is detected by the sheet size detecting unit of the two or more independent induction heating mechanisms are used. It is provided with a means for energizing only the corresponding induction heating mechanism, and the portion outside the paper size of the roller does not generate heat, and energy saving can be achieved.

According to a fourth aspect of the invention, in the induction heating roller device according to the second aspect, means for detecting or instructing the thickness of the paper on which the toner image is to be fixed, and thickness of the paper detected or instructed by this means. Correspondingly, the difference in the energization amount between the induction heating mechanism at both ends in the width direction and the induction heating mechanism at the center in the width direction among the two or more independent induction heating mechanisms and the two or more independent induction heating mechanisms. And a means for changing the energization amount of the induction heating mechanism so that the two or more independent induction heating mechanisms generate heat amounts suitable for the thickness of the sheet, and the roller is optimally expanded and contracted. As a result, it is possible to improve the paper feeding stability and save energy.

According to a fifth aspect of the present invention, in the induction heating roller device according to the second aspect, the detection means detects the humidity or the moisture content of the paper on which the toner image is to be fixed, and the detection result of the detection means. Of the two or more independent induction heating mechanisms, and a means for changing the difference in the energization amount between the induction heating mechanism at both ends in the width direction and the induction heating mechanism at the center in the width direction. Is expanded and contracted to the optimum amount according to the paper conditions, and the paper feeding stability is improved and energy saving is achieved.

According to a sixth aspect of the present invention, in the induction heating roller device according to the first or second aspect, which is used in an image forming apparatus that reads an image of a document and forms a toner image on a sheet, a margin portion of the document is detected. And a means for turning on / off the power supply to the two or more independent induction heating mechanisms corresponding to the blank area of the original detected by the original blank area detecting means. , The roller expands and contracts in accordance with the portion of the paper on which the toner image is present, thereby saving energy.

According to a seventh aspect of the present invention, in the induction heating roller device according to the first aspect, at least one temperature which is arranged in accordance with the two or more independent jacket chambers and detects the surface temperature of the roller is provided. It is equipped with a detecting means, and the surface temperature of the roller can be independently detected for each portion heated by induction heating mechanism, and the surface temperature of the roller is heated by induction heating mechanism by each induction heating mechanism. It is possible to control each independently.

According to an eighth aspect of the present invention, in the induction heating roller device according to the first aspect, a temperature fuse for detecting the surface temperature of the roller is provided in the entire area of the two or more independent induction heating mechanisms. Therefore, it is possible to operate the safety function by the thermal fuse even if any of two or more independent induction heating mechanisms run out of control.

According to a ninth aspect of the present invention, in the induction heating roller device according to the seventh aspect, the surface temperature of the roller provided rotatably is sequentially detected corresponding to the two or more independent jacket chambers. Since the temperature detecting means is provided, the surface temperature of the roller can be detected even if the induction heating mechanism is small, and the cost can be reduced.

[0017]

FIG. 1 shows a first embodiment of the present invention. The first embodiment is an embodiment of the invention described in claims 1 and 2, and is an embodiment of an induction heating roller device used in an image forming apparatus such as a copying machine, a facsimile, and a printer. In the first embodiment, the two or more independent induction heating mechanisms 11 to 1n are provided in the iron core 2 respectively.
1 to 2n are wound around the induction coils 31 to 3n, and the electric wires 41 to 4n for supplying current to the induction coils 31 to 3n are built in. And are placed independently.

A conductive cylindrical roller 6 made of a magnetic material having a hollow interior is rotatably attached to a fixed shaft 5 by bearings 7 and 8, and both ends of the fixed shaft 5 are a pair of machine bases 9 and 10. Fixed to. The induction heating mechanisms 11 to 1n are provided inside the roller 6, and two or more jacket chambers 101 to 10n are independently provided in the roller 6 at positions facing the induction heating mechanisms 11 to 1n along the axial direction. It is provided.

The jacket chambers 101 to 10n are filled with a gas-liquid two-phase heat medium, and the induction heating mechanisms 11 to 1n are independent from each other by bushes 111 to 11n-1. A cylinder is attached to the fixed shaft 5 so as to be located between the iron cores 21 to 2n, and pistons 171 to 17n-1 which are operated by hydraulic pressure are inserted into the cylinder.
A bush 1 is attached to the tip of each of the pistons 171 to 17n-1.
11-11n-1 are provided, and the bushes 111-1
The bearing mechanism is composed of inner cylinders 181 to 18n-1 embedded in 1n-1 and rolling elements 191 to 19n-1 made of rollers arranged between the outer circumference of the inner cylinders 181 to 18n-1 and the inner circumference of the roller 6. ing.

Further, the fixed shaft 5 is provided with a hydraulic hole 20 communicating with the cylinder, and the piston 17 is driven by hydraulic oil of a constant pressure supplied from the oil supply means through the hydraulic hole 20.
A force in the direction of pushing outward acts on 1 to 17n-1.
As a result, a force that pushes the roller 6 outward acts from the pistons 171 to 17n-1 via the bushes 111 to 11n-1, the inner cylinders 181 to 18n-1, and the rolling elements 191 to 19n-1.

The power sources 121 to 12n which are independent of each other are induction heating mechanisms 11 to 1n via electric wires 41 to 4n, respectively.
Of the induction coils 31 to 3n.
3n is driven by an alternating current to generate an alternating magnetic flux.
In the roller 6, an induction current flows due to the alternating magnetic flux generated by the induction coils 31 to 3n to generate Joule heat, that is, induction heating is performed to generate heat, and the surface temperature is made uniform by the heat medium in the jacket chambers 101 to 10n. .

Induction coil 31 from each power supply 121-12n
The amount of electricity to be supplied to .about.3n is controlled and determined by the control device 13, whereby the amount of heat generated on the surface of the roller 6 is independently determined for each induction heating mechanism 11 to 1n. Power supply 121-
12n can be set by varying the amount of electricity supplied to each of the induction coils 31 to 3n, and the heat generation amount on the surface of the roller 6 can be instantaneously changed by utilizing the fact that the temperature rises quickly, which is a characteristic of induction heat generation. Switching can be performed for each of the mechanisms 11 to 1n.

The induction heating roller in the induction heating roller device of the first embodiment is used as a fixing roller of a heating and fixing device. In this heating and fixing device, two induction heating rollers are pressed against each other by a pressing means such as a spring. It Copier,
An image forming apparatus such as a facsimile or a printer forms a toner image on a sheet from a sheet feeding device by an image forming unit according to an image signal obtained by reading an image of an original with an image reading unit or an image signal from the outside. When the sheet on which the image is formed passes through the nip portion of the two induction heating rollers, the toner image is fixed by heating by the induction heating roller.

As described above, the first embodiment is an embodiment of the invention described in claim 1, and is the roller 6 having the jacket chamber in which the heat medium is enclosed, and the roller 6 provided inside the roller 6. In the induction heating roller device including the rotatably formed induction heating roller including the induction heating mechanism that induction-heats the roller 6, the induction heating mechanism is arranged in the axial direction of the roller 6 and is independently energized. And at least two independent induction heating mechanisms 11 to 1n, and the jacket chamber includes two or more induction heating mechanisms 11 to 1n.
At least two independent jacket chambers 101 arranged in the axial direction of the roller 6 at positions opposed to each other in the circumferential direction.
Since it is composed of 10 to 10n, the roller can be partially expanded and contracted arbitrarily, the deflection amount of the roller can be sufficiently corrected, and the sheet feeding stability can be improved.

The first embodiment is an embodiment of the invention according to claim 2, and in the induction heating roller device according to claim 1, two or more independent induction heating mechanisms 11 to 1n. Since the power sources 121 to 12n as means for varying the energization amount independently energized are provided, the heat generation distribution and the uneven shape of the roller surface can be arbitrarily changed according to the image forming conditions, and the deflection amount of the roller can be changed. Can be sufficiently corrected, and the paper feeding stability can be improved.

FIG. 2 shows part of a second embodiment of the present invention. The second embodiment is an embodiment of the invention described in claim 3. In the second embodiment, the known paper size detecting device 14 for detecting the size of the paper conveyed from the paper feeding device to the heat fixing device in the first embodiment is used.
Is provided in the image forming apparatus. And the control device 13
In response to the paper size detection signal from the paper size detection device 14, the induction heating mechanism 11 is supplied to the power supplies 121 to 12n.
In 1n, the power supply to the induction heating mechanism for inductively heating the portion of the roller 6 on which the paper is not passed (the portion where the paper does not pass) is turned off, and the roller 6 is rotated in the induction heating mechanism 11-1n.
The power supply for energizing the induction heating mechanism for inductively heating the upper portion where the paper is passed (the portion where the paper passes) is turned on. As a result, it is possible to save energy by eliminating wasteful power consumption.

As described above, the second embodiment is an embodiment of the invention according to claim 3, and in the induction heating roller device according to claim 1 or 2, the paper on which the toner image is to be fixed. A paper size detecting device 14 as a paper size detecting means for detecting the size and only the induction heating mechanism corresponding to the size of the paper detected by the paper size detecting means 14 among the two or more independent induction heating mechanisms 11 to 1n are energized. Since the control device 13 is provided as a means for doing so, energy can be saved without heating the portion of the roller outside the paper size.

FIG. 3 shows part of a third embodiment of the present invention. The third embodiment is an embodiment of the invention described in claim 4. In general, when thick paper is used as the paper, the paper is less likely to cause wrinkles and may have a small concave (hand-shaped) shape of the roller 6. Further, the thick paper must give a large amount of heat for fixing the toner image in order to secure the fixing property.

Therefore, in the third embodiment, the known paper thickness detecting device 15 for detecting the thickness of the paper conveyed from the paper feeding device to the heat fixing device in the second embodiment is used.
Is provided in the image forming apparatus. And the control device 13
Is based on the paper size detection signal from the paper size detection device 14 and the paper thickness detection signal from the paper thickness detection device 15.
21 to 12n are the energization differences of the induction heat generating mechanism 11 to 1n between the induction heat generating mechanism at both ends in the width direction and the induction heat generating mechanism at the central portion in the width direction, and the amount of current to the induction heat generating mechanism 11 to 1n is optimum. The induction difference heating mechanism 11 to 1n is controlled to generate the optimum heat generation amount for the size and the thickness of the paper when the amount difference Δ and the optimum power supply amount are reached.

As a result, the surface of the roller 6 instantly becomes an optimum amount of heat generation and an optimum drum shape due to the characteristic of induction heat generation.
Stable fixability and paper feeding stability can be secured. Here, for example, the drum-like shape of the roller 6 is for injecting the pressure of the nip portion in the direction of expanding the sheet passing through the nip portion of the two induction heating rollers to the outside, and is effective for the wrinkling of the sheet.
Wrinkles occur on the paper regardless of whether the roller 6 has a large or small hourglass shape. However, since the surface of the roller 6 has the optimum amount of heat generation and the optimum drum shape, wrinkling of the paper does not occur, and stable fixing property and paper feeding stability can be secured.

The fourth embodiment of the present invention is defined in claim 4.
It is another embodiment of the described invention, and in the third embodiment, a known paper thickness indicating device for instructing the thickness of the paper by the user is used instead of the paper thickness detecting device 15. is there.

As described above, the third embodiment and the fourth embodiment are embodiments of the invention described in claim 4, and the toner image should be fixed in the induction heating roller device described in claim 2. Means 15 for detecting or instructing the thickness of paper
And two or more independent induction heating mechanisms 11 to 1n corresponding to the thickness of the sheet detected or indicated by the means 15.
Of the induction heating mechanism at both end portions in the width direction and the induction heating mechanism at the center portion in the width direction, and the energization amounts of the two or more independent induction heating mechanisms 11 to 1n are two or more independent inductions. Since the heat generating mechanisms 11 to 1n are provided with the control device 13 as a means for changing the heat generation amount suitable for the thickness of the paper, the rollers are optimally expanded and contracted to provide stable fixing and paper feeding stability. Can be secured and energy saving can be achieved.

FIG. 4 shows part of a fifth embodiment of the present invention. The fifth embodiment is an embodiment of the invention described in claim 5. In general, paper containing water is likely to have wrinkles. For this reason, the larger the hourglass shape of the roller 6 is, the more stable the sheet conveying property is. However, when a sheet containing normal water is sent to the roller 6 having a large hourglass shape, wrinkles are generated in the opposite direction.

Therefore, in the fifth embodiment, in the second embodiment, the known paper moisture content detecting device 16 for detecting the moisture content of the paper conveyed from the paper feeding device to the heat fixing device forms an image. Provided in the device. Then, the control device 13 controls the power sources 121 to 12n among the induction heating mechanisms 11 to 1n based on the paper size detection signal from the paper size detection device 14 and the paper moisture content detection signal from the paper moisture content detection device 16. The difference in energization amount Δ between the induction heating mechanism at both end portions in the width direction and the induction heating mechanism at the center portion in the width direction is the optimum energization amount difference, and the induction heating mechanisms 11 to 1n are optimal for the size of the paper and the moisture content of the paper. It is controlled to generate heat according to the heat generation amount.

As a result, the surface of the roller 6 instantly becomes an optimum amount of heat generation and an optimum drum shape due to the characteristic of induction heat generation.
The paper feeding stability can be secured. Here, for example, generally, the smaller the paper size is, the more difficult the paper is to be wrinkled. However, even if the paper size is small due to factors such as crevices in the paper, wrinkles occur in the paper, and the optimum drum-shaped shape of the roller 6 differs depending on the paper size. In the fifth embodiment, the induction amount difference Δ between the induction heating mechanism at both ends in the width direction and the induction heating mechanism at the central portion in the width direction of the induction heating mechanisms 11 to 1n becomes an optimal difference in the amount of induction. Since the heat generating mechanisms 11 to 1n generate the optimum amount of heat for the size of the paper and the moisture content of the paper,
Wrinkles on the paper will not occur.

The sixth embodiment of the present invention is defined in claim 5.
It is another embodiment of the invention described above, and in the fifth embodiment, an in-apparatus humidity device for detecting the humidity in the image forming apparatus is used instead of the paper moisture content detecting apparatus 16. .

As described above, the fifth embodiment and the sixth embodiment are embodiments of the invention according to claim 5, and in the induction heating roller device according to claim 2, the humidity or the toner image is fixed. The detection means 16 for detecting the moisture content of the paper to be formed, and the induction heat generation mechanism and the width at both ends in the width direction of the two or more independent induction heat generation mechanisms 11 to 1n corresponding to the detection result of the detection means 16. Since the controller 13 is provided as a means for changing the difference in the amount of electricity supplied to the induction heating mechanism in the central portion of the direction, the rollers can be expanded and contracted to an optimum amount that matches the paper conditions, and the paper feeding stability can be improved. It is possible to improve and save energy.

FIG. 5 shows a part of the seventh embodiment of the present invention. The seventh embodiment is an embodiment of the invention described in claim 6. In an image forming apparatus such as a digital copying machine or a Fukushimari, it is possible to identify the position of the margin of the document on the sheet. Even in the analog copying machine, it is possible to identify the position of the margin portion of the document on the sheet by the reduction ratio with respect to the document size, the margin portion setting on the copy, and the like. It is useless to give a heat amount for fixing the toner image to the margin of the paper.

Therefore, in the seventh embodiment, the document margin detecting device 17 and the paper size detecting device 1 for detecting or identifying at which position on the paper the margin portion of the document is located.
In the induction heating roller device according to the first embodiment, which has No. 4 and is used for an image forming apparatus that reads an image of a document by an image reading unit and forms a toner image on a sheet by an image forming unit, the control device 13 , The paper size detection signal from the paper size detection device 14, the document margin detection signal from the document margin detection device 17, and the image formation condition (copy condition) data such as the document size and the magnification from the main body of the image forming apparatus. The position on the roller 6 corresponding to the blank area on the copy and the time taken for the blank area on the copy to pass are calculated, and based on this calculation result, the power sources 121 to 12n are operated by the induction heating mechanisms 11 to 1n. In the induction heating mechanisms 11 to 1n, the power supply to the induction heating mechanism for inductively heating the portion of the roller 6 on which the paper is not passed (the portion where the paper does not pass) is turned off, and the paper is passed on the roller 6 in the induction heating mechanisms 11 to 1n. In part to turn on the power supply for energizing the induction heating mechanism for induction heating (a portion through which sheet) only when the paper passes. As a result, the portion of the roller 6 necessary for fixing the toner image generates heat only during fixing, and it is possible to eliminate wasteful power consumption and save energy.

As described above, the seventh embodiment is characterized by claim 6.
The induction heating roller device according to claim 1 or 2, which is an embodiment of the described invention, and is used in an image forming apparatus that reads an image of a document and forms a toner image on a sheet.
A document margin detecting device 17 as a document margin detecting unit for detecting a margin of the document, and two or more independent induction heating mechanisms 11 to 11 corresponding to the margins of the document detected by the document margin detecting unit 17. Since the control device 13 is provided as a means for turning on / off the 1n energization, it is possible to save energy without heating the portion corresponding to the document margin portion on the roller.

FIG. 6 shows an eighth embodiment of the present invention. The eighth embodiment is an embodiment of the invention described in claim 7. In the first embodiment, the induction heating mechanism 1 including the iron cores 21 to 2n and the induction coils 31 to 3n.
1 to 1n are independent from each other in the axial direction of the roller 6 and are respectively energized by independent power supplies 121 to 12n. Therefore, each induction heating mechanism 1 on the roller 6
Each of the parts corresponding to 1 to 1n and the jacket chambers 101 to 10n generates heat with an independent heat generation amount.

Therefore, in the eighth embodiment, in each of the induction heating mechanisms 11 to 11 on the roller 6 in the first embodiment.
In order to control the heat generation amount of each portion corresponding to 1n by the control device 13, the temperature detection is performed at a position facing each induction heating mechanism 11 to 1n on the roller 6 and each portion corresponding to the jacket chambers 101 to 10n. The devices 211 to 21n are arranged, and the temperature detecting devices 211 to 21n are the induction heating mechanisms 11 to 1n on the roller 6 and the jacket chamber 10.
The temperature of each part corresponding to 1 to 10n is detected. The control device 13 controls the power sources 121 to 12n by the temperature detection signals from the temperature detection devices 211 to 21n to control the temperatures of the respective portions corresponding to the induction heating mechanisms 11 to 1n on the roller 6 and the jacket chambers 101 to 10n, respectively. By controlling so as to reach the set temperature, each induction heating mechanism 11-
Control 1n independently.

As described above, the eighth embodiment is an embodiment of the invention according to claim 7, and in the induction heating roller device according to claim 1, two or more independent jacket chambers 101 to 101 are provided. Since the temperature detectors 211 to 21n as at least one temperature detector for detecting the surface temperature of the roller 6 arranged according to 10n are provided, the surface temperature of the roller is induction-heated by each induction heating mechanism. The surface temperature of the roller can be independently controlled for each part, and the surface temperature of the roller can be independently controlled for each part that is induction-heated by each induction heating mechanism.

FIG. 7 shows a ninth embodiment of the present invention. The ninth embodiment is an embodiment of the invention described in claim 8. In the ninth embodiment, since the induction heating mechanisms 11 to 1n are independent from each other in the first embodiment,
A temperature fuse 30 for preventing runaway of heat generation of the roller 6 is arranged over the entire area of the induction heating mechanisms 11 to 1n.
In the thermal fuse 30, the resin 301 that melts at a constant temperature is arranged in the outer tube 302 over the entire area of the induction heating mechanisms 11 to 1n.

The outer tube 302 is composed of metal cylinders 311 to 31n at positions corresponding to the induction heating mechanisms 11 to 1n, and the other part is composed of a cylinder 321 made of a heat insulating member. The resin 301 in the outer tube 302 is pressed toward the inner side of the outer tube 302 by a spring 323 by a partition wall 322 that is movably provided in the outer tube 302 and that can be energized.
2 and the spring 323 are connected so that the safety function is activated and the power is supplied.

Since the outer tube 302 is arranged over the entire area of the induction heating mechanisms 11 to 1n, if the outer tube 302 is made entirely of metal, the heat capacity is large. It takes time for the resin 301 to melt and the damage to the roller 6 increases. Therefore,
The metal cylinders 311 to 31n are divided into lengths corresponding to the lengths of the induction heating mechanisms 11 to 1n to suppress the heat capacity.

When the heat generated by the roller 6 runs away, the metal cylinder 3
Out of the outer tubes 30 to 31n, the temperature of the metal cylinder facing the heat runaway portion of the roller 6 rises abnormally.
The resin 301 in 2 melts inside the metal cylinder. As a result, when the partition wall 322 is retracted toward the inside of the outer tube 302 and separated from the spring 323, the thermal fuse 3
When 0, the power is cut off and it operates, and the safety function works.

As described above, the ninth embodiment is an embodiment of the invention according to claim 8, and in the induction heating roller device according to claim 1, two or more independent induction heating mechanisms 11 are provided. Since the temperature fuse 30 for detecting the surface temperature of the roller 6 is provided in the entire range from 1 to 1n, it is possible to operate the safety function by the temperature fuse even if any of the independent induction heating mechanisms run out of control.

FIG. 8 shows a tenth embodiment of the present invention.
The tenth embodiment is an embodiment of the invention described in claim 9. In the tenth embodiment, in the first embodiment, the light source 324, the mirror 325, and the light receiving section 32 are provided.
The temperature detecting means consisting of 6 is used. The light source 324 is rotationally driven by a rotational drive source (not shown) and emits infrared rays while rotating in the axial direction of the roller 6.

Infrared rays from the light source 324 are emitted to and reflected by the roller 6, and infrared rays reflected between points 327 and 328 on the roller 6 corresponding to both ends of the induction heating mechanisms 11 to 1n are received by the mirror 325. It is focused on the part 326. The light receiving section 326 is formed on the roller 6 by the induction heating mechanisms 11 to 11.
The amount of infrared light received via the mirror 325 is sequentially detected from the respective portions corresponding to 1n and the jacket chambers 101 to 10n.

The control device 13 controls each of the rollers 6 on the roller 6 detected by the light receiving section 326 based on the output signal of the light receiving section 326 corresponding to each of the induction heating mechanisms 11 to 1n on the roller 6 and the portions corresponding to the jacket chambers 101 to 10n. Induction heating mechanism 11
˜1n and the amount of infrared light from each part corresponding to the jacket chambers 101 to 10n is converted into the temperature on the roller 6, and the induction heating mechanisms 11 to 1 on the roller 6 are converted by the temperatures.
n and power sources 121 to 12n so that the temperature of each part corresponding to the jacket chambers 101 to 10n becomes a constant set temperature.
By controlling each of the induction heating mechanisms 11 to 1n independently. Thus, even if the induction heating mechanisms 11 to 1n are finely divided, the temperature of each portion corresponding to the induction heating mechanisms 11 to 1n and the jacket chambers 101 to 10n on the roller 6 can be measured, and a temperature detecting element such as a thermistor can be used. Since it is not necessary to arrange the induction heating mechanisms 11 to 1n in number, it is possible to reduce the cost.

As described above, the tenth embodiment is an embodiment of the invention according to claim 9, and in the induction heating roller device according to claim 7, the surface temperature of the roller 6 rotatably provided. 2 or more independent jacket rooms 1
Since the temperature detecting means including the light source 324, the mirror 325, and the light receiving section 326 for sequentially detecting 01 to 10n is provided, the surface temperature of the roller can be detected even if the induction heating mechanism is small, and the cost can be reduced. You can measure down.

The present invention is not limited to the above-described embodiment. For example, not only an induction heating roller device having two induction heating rollers but also one induction heating roller and another roller are provided. It can also be applied to an induction heating roller device.

[0054]

As described above, according to the first aspect of the present invention, the roller having the jacket chamber in which the heat medium is enclosed, and the induction heating mechanism provided inside the roller for inductively heating the roller are provided. In an induction heating roller device having an rotatably configured induction heating roller, the induction heating mechanism is arranged in the axial direction of the roller and has at least two independent induction heating mechanisms that are independently energized. Since the jacket chamber is composed of at least two or more independent jacket chambers arranged in the axial direction of the roller at positions circumferentially opposed to the two or more induction heating mechanisms, the rollers are partially formed. In addition, it is possible to arbitrarily expand and contract, and it is possible to sufficiently correct the amount of deflection of the roller, and it is possible to improve the paper feeding stability.

According to the second aspect of the invention, in the induction heating roller device according to the first aspect, there is provided means for varying the amount of electricity to be independently applied to the two or more independent induction heating mechanisms. Further, the heat generation distribution and the uneven shape of the roller surface can be arbitrarily changed according to the image forming condition, the deflection amount of the roller can be sufficiently corrected, and the sheet feeding stability can be improved.

According to the third aspect of the invention, in the induction heating roller device according to the first or second aspect, the sheet size detecting means for detecting the size of the sheet on which the toner image is to be fixed, and the two or more independent units are provided. Of the induction heating mechanism, means for energizing only the induction heating mechanism corresponding to the size of the paper detected by the paper size detecting means is provided, so energy can be saved without heating the portion of the roller outside the paper size. You can

According to the invention described in claim 4, in the induction heating roller device according to claim 2, means for detecting or instructing the thickness of the paper on which the toner image is to be fixed, and the paper detected or instructed by this means. 2 according to the thickness of
Among the two or more independent induction heating mechanisms, the difference in the energization amount between the induction heating mechanism at both ends in the width direction and the induction heating mechanism at the center in the width direction and the energization amount of the two or more independent induction heating mechanisms are described above. Since two or more independent induction heating mechanisms are provided with means for changing the amount of heat generation suitable for the thickness of the paper, the rollers are optimally expanded and contracted to provide stable fixing and paper feeding stability. Can be secured and energy saving can be achieved.

According to the fifth aspect of the invention, in the induction heating roller device according to the second aspect, the detection means for detecting the humidity or the moisture content of the paper on which the toner image is to be fixed, and the detection result of this detection means are used. Correspondingly, means for changing the difference in the energization amount between the induction heating mechanism at both ends in the width direction and the induction heating mechanism at the center in the width direction among the two or more independent induction heating mechanisms are provided. Can be expanded or contracted to an optimum amount according to the paper condition, and the paper feeding stability can be improved and energy saving can be achieved.

According to a sixth aspect of the invention, in the induction heating roller device according to the first or second aspect, which is used in an image forming apparatus for reading an image of a document and forming a toner image on a sheet, the margin portion of the document is used. And a means for turning on / off the energization of the two or more independent induction heating mechanisms corresponding to the blank area of the original detected by the original blank area detecting means. It is possible to save energy without heating the portion of the roller corresponding to the blank area of the document.

According to the invention described in claim 7, in the induction heating roller device according to claim 1, at least one or more of the induction heating roller devices are arranged corresponding to the two or more independent jacket chambers to detect the surface temperature of the roller. Since the temperature detecting means is provided, the surface temperature of the roller can be detected independently for each portion heated by induction heating mechanism, and the surface temperature of the roller is heated by induction heating mechanism by each portion. It is possible to control each independently.

According to an eighth aspect of the present invention, the induction heating roller device according to the first aspect is provided with a temperature fuse for detecting the surface temperature of the roller over the entire area of the two or more independent induction heating mechanisms. Therefore, even if any of the independent induction heating mechanisms run away, the safety function can be activated by the thermal fuse.

According to a ninth aspect of the present invention, in the induction heating roller device according to the seventh aspect, the surface temperature of the roller provided rotatably is sequentially set in correspondence with the two or more independent jacket chambers. Since the temperature detecting means for detecting is provided, the surface temperature of the roller can be detected even if the induction heating mechanism is small, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention.

FIG. 2 is a block diagram showing a part of a second embodiment of the present invention.

FIG. 3 is a block diagram showing a part of a third embodiment of the present invention.

FIG. 4 is a block diagram showing a part of a fifth embodiment of the present invention.

FIG. 5 is a block diagram showing a part of a seventh embodiment of the present invention.

FIG. 6 is a sectional view showing an eighth embodiment of the present invention.

FIG. 7 is a sectional view showing a ninth embodiment of the present invention.

FIG. 8 is a sectional view showing a tenth embodiment of the present invention.

[Explanation of symbols]

 11-1n Induction heating mechanism 5 Fixed shaft 6 Roller 101-10n Jacket chamber 111-11n-1 Bush 121-1 2n Power supply 13 Control device 14 Paper size detection device 15 Paper thickness detection device 16 Paper moisture detection device 17 Original margin detection device 211-21n Temperature detection device 30 Thermal fuse 324 Light source 325 Mirror 326 Light receiving part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Keizo Yasuda 1-3-6 Nakamagome, Ota-ku, Tokyo, Ricoh Co., Ltd. (72) Inventor Masahiko Sato 1-3-6 Nakamagome, Ota-ku, Tokyo・ In stock company Ricoh (72) Inventor Masahisa Ehara 1-3-6 Nakamagome, Ota-ku, Tokyo ・ In stock company Ricoh (72) Inventor Takayuki Seki 1-3-6 Nakamagome, Tokyo Inside Ricoh Company (72) Inventor Yuzo Kono 1-3-6 Nakamagome, Ota-ku, Tokyo

Claims (9)

[Claims] 1. A rotatably constructed induction heating roller comprising a roller having a jacket chamber in which a heat medium is enclosed, and an induction heating mechanism provided inside the roller for inductively heating the roller. In the induction heating roller device, the induction heating mechanism includes at least two or more independent induction heating mechanisms arranged in the axial direction of the roller and independently energized, and the jacket chamber has the two or more induction heating mechanisms. An induction heating roller device comprising at least two or more independent jacket chambers arranged in the axial direction of the roller at positions facing the mechanism in the circumferential direction. 2. The induction heating roller device according to claim 1, further comprising means for varying an energization amount for independently energizing the two or more independent induction heating mechanisms. . 3. The induction heating roller device according to claim 1 or 2, wherein the paper size detecting means for detecting the size of the paper on which the toner image is to be fixed, and the paper among the two or more independent induction heating mechanisms. An induction heating roller device comprising: means for energizing only an induction heating mechanism corresponding to the size of the sheet detected by the size detecting means. 4. The induction heating roller device according to claim 2, wherein the means for detecting or instructing the thickness of the paper on which the toner image is to be fixed, and the thickness of the paper detected or instructed by this means, Of the two or more independent induction heating mechanisms, the difference in the energization amount between the induction heating mechanism at both ends in the width direction and the induction heating mechanism at the center in the width direction, and the energization amount of the two or more independent induction heating mechanisms. And a means for changing the two or more independent induction heating mechanisms so as to generate a heat generation amount suitable for the thickness of the sheet, the induction heating roller device. 5. The induction heating roller device according to claim 2, wherein a detection unit for detecting humidity or moisture content of a sheet on which a toner image is to be fixed, and the two or more of the detection units corresponding to the detection result of the detection unit. An induction heating roller device comprising: means for changing a difference in energization amount between an induction heating mechanism at both end portions in the width direction and an induction heating mechanism at a center portion in the width direction among independent induction heating mechanisms. 6. An induction heating roller device according to claim 1, which is used in an image forming apparatus for reading an image of a document to form a toner image on a sheet, and a document margin detection unit for detecting a margin of the document. And an induction heating roller device for turning on / off the energization of the two or more independent induction heating mechanisms corresponding to the margins of the document detected by the document margin detecting means. . 7. The induction heating roller device according to claim 1, further comprising at least one temperature detecting means arranged corresponding to the two or more independent jacket chambers for detecting the surface temperature of the roller. Induction heating roller device characterized by. 8. The induction heating roller device according to claim 1, further comprising a temperature fuse for detecting a surface temperature of the roller over the entire area of the two or more independent induction heating mechanisms. Roller device. 9. The induction heating roller device according to claim 7, wherein the surface temperature of the roller is rotatably provided so that
An induction heating roller device comprising temperature detecting means for sequentially detecting one or more independent jacket chambers.