JPH05297741A - Heat fixing device - Google Patents

Abstract

(57) [Summary] [Purpose] The heat distribution is made uniform over the length of the heating roller 1 without increasing the power consumption, and the heating roller 1 and other components are thermally insulated by a simple structure. Providing a heat fixing device. [Structure] A heating roller 1 composed of a hollow cylindrical body 3 having a heating element 4 inside and an elastic roller 2 arranged in proximity to the heating roller 1 in parallel are used to record an unfixed toner image on a recording sheet. A heat fixing device for heating and fixing to a sheet, wherein the hollow cylindrical body 3 includes a fitting portion 5a into which both ends of the hollow cylindrical body 3 are fitted, and a lid portion 5b in which both end openings of the hollow cylindrical body 3 are sealed. Is held by a bearing 5 made of a heat insulating material, and the elastic roller 2 constitutes a drive roller,
The heating roller 1 constitutes a driven roller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat fixing device for fixing a toner image formed on a recording sheet by an electrophotographic recording method to the recording sheet by heating and pressurizing the toner image. The present invention relates to the above-described heating and fixing device in which the heat transfer efficiency is uniform in the lengthwise direction and the heat use efficiency at the time of fixing is improved.

[0002]

2. Description of the Related Art Generally, a heat fixing device is used to heat and fix a toner image formed on a recording sheet by an electrophotographic recording method onto the recording sheet. The heating and fixing device is composed of a heating roller having a heating element therein and an elastic roller arranged in close proximity to the heating roller. The recording paper on which a toner image is formed is heated by the heating and elastic roller. The toner image is fixed on the recording sheet by heating and applying pressure during the insertion.

FIG. 8 is a sectional view showing an example of the structure of one bearing portion in a conventional heat fixing device.

In FIG. 8, 50 is a heating roller, 51 is an elastic roller, 52 is a hollow cylindrical body, 53 is a heating element, 54 is a sliding bearing, 55 is a drive unit, 56 is a spring, and 57 is a frame of a heat fixing device. Reference numerals 58 denote heating element support portions.

The heating roller 50 is a hollow cylindrical body 5.
2 and a rod-shaped heating element 53 arranged at the axial center of the hollow cylindrical body 52. In this case, both ends of the hollow cylindrical body 52 form openings, and both ends of the heat generating element 53 are supported by the heat generating element supporting portion 58 in the opening. An elastic roller 51 is disposed in proximity to the heating roller 50, and the elastic roller 51 is always in contact with the heating roller 50 by pressing a spring 56. A slide bearing 54 for holding the heating roller 50 on the frame 57 of the heat fixing device and a drive unit 55 for rotating the heating roller 50 are arranged side by side on the outer peripheral portion near both ends of the heating roller 50. The heating element support portion 58 is also held by the frame 57 of the heat fixing device.

The heat-fixing device having the above-described structure operates as follows.

Now, the heating element 5 is connected through the heating element supporting portion 58.
3 is supplied with electric power to heat the heating element 53 to bring the heating roller 50 into a heated state, and then the heating roller 50 is rotationally driven through the drive unit 55. The elastic roller 51 in contact with the heating roller 50 also rotates at the same speed. At this time, when a recording paper (not shown) on which a toner image is formed is conveyed between the heating roller 50 and the elastic roller 51, the toner image on the recording paper is heated by the heating roller 50 (heat (The transmission direction is indicated by arrow A) and the pressure is applied from the two rollers 50, 51 when passing between the heating roller 50 and the elastic roller 51, so that it is fixed on the recording sheet. Become so.

In this case, the heat generated by the heating element 53 is transmitted through the hollow cylindrical body 52 in the direction of the elastic roller 51 (direction of arrow A), whereby the toner image is fixed. In addition, the heat of the heating element 53 is passed through the hollow cylindrical body 52 in the direction of the bearing 54 of the heat insulating material (direction of arrow B), and also through the hollow cylindrical body 52 in the direction of the drive unit 55 (direction of arrow C). Is also transmitted, and further, since both ends of the hollow cylindrical body 52 are open, they are also transmitted to the outside (direction of arrow D). As described above, the heat of the heating element 53 is particularly lost at both ends of the heating roller 50. Therefore, in the heat fixing device, the heat is uniform over the length of the heating roller 50. For example, it becomes difficult to uniformly heat the entire recording sheet.

As one means for improving these points,
There has already been proposed a heat fixing device which uses a heating element having a larger heat generation distribution in both end portions than in the central portion and performs uniform heating along the length direction of the heating roller.

However, the heat fixing device according to the above-mentioned proposal has a problem that the amount of heat that does not directly contribute to fixing increases and power consumption increases. There is also a problem in that the arranged equipment is heated and various functional problems occur.

As another means for improving the above points, a heating roller whose both ends are closed is used, and a sliding bearing made of a heat insulating material and a drive gear made of a heat insulating material are arranged on the rotary shaft of the heating roller. When combined with each other, a heating and fixing device capable of uniformly heating the heating roller in the longitudinal direction with low power consumption is disclosed in Japanese Patent Publication No. 3-2467.
It is newly proposed as No. 2.

FIG. 9 is a sectional view showing the structure of one bearing portion of the newly proposed heat fixing device.

In FIG. 9, 60 is a heating roller, 61 is a pressure roller, 62 is a heater for heating, 63 is a rotating shaft, and 64 is a rotating shaft.
Is a slide bearing made of a heat insulating material, 65 is a support frame of the heat fixing device, 66 is a heat resistant gear made of a heat insulating material, 67 is a transmission gear, and 6
Reference numeral 8 is a drive source, and 69 is a bearing.

The heating roller 60 has a hollow cylindrical body whose both ends are closed, a rod-shaped heater 62 arranged at the axial center of the hollow cylindrical body, and closed portions at both ends of the hollow cylindrical body. And a rotary shaft 63 that protrudes outward in the axial direction. Both ends of the heater 62 for heating are inserted and supported in the rotary shaft 63, and the pressure roller 61 is arranged in proximity to the heating roller 60. A slide bearing 64 for holding the heating roller 60 on a supporting frame 65 of the heat fixing device and a heat-resistant gear 66 for driving the heating roller 60 to rotate are arranged and connected to the outer periphery of the rotating shaft 63. Has been done. The tip of the rotary shaft 63 is pivotally supported by the support frame 65, and the rotary shaft of the pressure roller 61 is also supported by the support frame 6 via a bearing 69.
It is supported by 5. The heat resistant gear 66 is the transmission gear 6
It is coupled to the drive source 68 via 7.

The newly proposed heat fixing device having the above-described structure operates as follows.

Electric power is supplied to the heater 62 for heating through the rotary shaft 63 so that the heater 62 generates heat and the heating roller 6 is heated.
After heating 0, the rotational driving force from the driving source 68 is transmitted through the transmission gear 67 and the heat resistant gear 66 to the heating roller 6
When the heating roller 60 is driven to rotate,
The heating roller 6 corresponds to the rotation of the heating roller 60.
The pressure roller 61 in contact with 0 also rotates at the same speed. At this time, when a recording sheet (not shown) on which a toner image is formed is conveyed between the heating roller 60 and the pressure roller 61, the toner image on the recording sheet is heated by the heating roller 60, Upon receiving pressure between the heating roller 60 and the pressure roller 61, the toner is fixed on the recording sheet.

Also in this case, the heat generated by the heating heater 62 is transmitted to the pressure roller 61 through the hollow cylindrical body of the heating roller 60, thereby fixing the toner image. The heat of the heater 62 is transmitted to the plain bearing 64 via the hollow cylinder and also to the heat resistant gear 66 via the hollow cylinder. However, in the newly proposed heat fixing device, since the slide bearing 64 and the heat resistant gear 66 are made of a heat insulating material, the slide bearing 64 and the heat resistant gear 66 are interposed via the hollow cylindrical body. The heat transferred in the direction becomes small, and a large amount of the heat is used for fixing the toner image.

[0018]

However, even in the newly proposed heat fixing device, the heating roller 6 is used.
In order to make the heat generation distribution uniform over the length direction of 0, it is actually necessary to increase the heat generation amount at both end portions of the heating roller 60 to some extent as compared with the heat generation amount at the central portion thereof. It is necessary to make the heat generation distribution of the heater 62 for both ends larger than the central part.
And when such heat distribution is set,
Although there are differences in degree, there are still problems such as the increase in power consumption and the heating of peripheral devices due to an increase in heat radiation as described above.

In the newly proposed heat fixing device, all the members in contact with the heating roller 60, such as the slide bearing 64 and the heat resistant gear 66, are made of a heat insulating material, and Although a heat insulating structure is adopted in which heat is not transferred to devices or the like arranged around the heat fixing device through the member, in general,
The heat fixing device has a pressing means for pressing the heating roller 60 toward the pressing roller 61 facing the heating roller 60, and a mechanism for canceling a jam on the recording sheet, and includes the pressing means and the releasing mechanism. If the heat insulating structure is adopted for the parts, there is a problem that the structure part becomes complicated and the whole heat fixing device becomes large in size.

The present invention eliminates these problems, and an object thereof is to make the heat generation distribution uniform over the length of the heating roller without increasing the power consumption, and to provide the heating roller with a simple structure. Another object of the present invention is to provide a heat fixing device that is thermally insulated from other components.

[0021]

In order to achieve the above object, the present invention provides a heating roller composed of a hollow cylindrical body having a heating element therein, and an elastic roller arranged in parallel with and in parallel with the heating roller. In the heat fixing device for heating and fixing the unfixed toner image on the recording paper to the recording paper, the hollow cylindrical body has a fitting portion into which both ends of the hollow cylindrical body are fitted and both end openings of the hollow cylindrical body. Is held by a bearing of a heat insulating material having a lid part that is sealed,
Further, the elastic roller is provided with main means constituting a driving roller.

Further, in order to achieve the above object, the present invention is preferably such that a bearing of the heat insulating material holds a heating element inside the hollow cylindrical body, a heating element holding means, and the heating roller is the elastic roller. Roller pressing means abutting against the bearing for pressing to the side, heat reflecting means having the inner surface of the hollow cylindrical body and the inner surface of the hollow cylindrical body of the bearing of the heat insulating material as a heat reflecting surface, respectively. At least one or more additional means for retracting means for allowing the heating roller to move to the retracted position with respect to the elastic roller fixedly arranged during maintenance of the heat fixing device.

[0023]

According to the main means, the hollow cylindrical body has a bearing made of a heat insulating material having a fitting portion into which both ends of the hollow cylindrical body are fitted and a lid portion in which both end openings of the hollow cylindrical body are sealed. Since the hollow cylindrical body is held by the both ends, the both ends of the hollow cylindrical body are held by the fitting portions of the bearing in a heat insulating state, and the both end openings are effectively closed. For this reason, the heat transferred from the heating roller to the bearing side and the heat transferred from the inside of the heating roller to the outside through the openings at both ends are both minimized. In most cases, it can be realized with a relatively simple structure.

According to the main means, since the elastic roller constitutes the driving roller and the heating roller constitutes the driven roller, it is necessary to connect the roller driving means made of a heat insulating material to the heating roller. Disappears. For this reason, heat is not transferred from the heating roller to the roller driving means side, so that the peripheral devices are not heated by the transfer of heat, and it can be realized with a simple configuration. ..

According to the additional means, the heating element inside the hollow cylindrical body is held by the bearing of the heat insulating material. Therefore, the roller holding means for the heating roller and the heating element holding for the heating element are held. Since the means is common, the number of parts can be reduced and the structure can be simplified accordingly.

According to the additional means, since the roller pressing means for pressing the heating roller toward the elastic roller is brought into contact with the bearing made of the heat insulating material, the roller application from the heating roller is performed. The heat is hardly transferred to the pressure means side, and the peripheral devices are not heated by the heat transfer.

Further, according to the additional means, since the inner surface of the hollow cylindrical body and the surface of the bearing of the heat insulating material on the inner side of the hollow cylindrical body are heat reflecting surfaces, The heat inside the heating roller is reflected by the heat reflecting surface, and the heat transmitted and outflowed to the outside of the heating roller can be further reduced, and the peripheral equipment is heated by the heat outflow. Considerably reduced.

In addition to the above, according to the additional means, the heating roller can be moved to the retracted position with respect to the elastic roller fixedly arranged at the time of maintenance of the heating and fixing device.
For example, the elastic roller serving as a driving roller is arranged on the lower side, and the heating roller serving as a driven roller is arranged on the upper side, and at the time of the maintenance, the elastic roller side is fixed and the heating roller side is oriented upward. Since it is flipped up to be in a retractable state, the configuration is relatively simple and the overall size can be reduced.

[0029]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a constitutional view showing a first embodiment of a heat fixing device according to the present invention, in which (a) is a side view showing a partial cross section and (b) is a cross sectional view. In addition, FIG.
It is an expanded sectional view showing details of composition of one bearing part of the 1st example.

In FIGS. 1 and 2, 1 is a heating roller,
2 is an elastic roller whose surface is made of a heat insulating elastic material such as silicon rubber, 3 is a hollow cylindrical body made of a material having a high thermal conductivity such as metal, 4 is a rod-shaped heating body made of a halogen heater or the like, and 5 is Bearings made of heat insulating material, 5a are fitting portions of bearings, 5a
Reference numeral b is a cover portion of the bearing, 6 is a gear for rotationally driving the elastic roller, 7 is a roller pressing means composed of a spring, and 8 is a support frame of the heat fixing device.

The heating roller 1 comprises a hollow cylindrical body 3
And a rod-shaped heating body 4 arranged at the axial center of the hollow cylindrical body 3. Fitting portions 5a of the bearing 5 are fitted on the inner surfaces of both ends of the hollow cylindrical body 3, and openings at both ends of the hollow cylindrical body 3 are sealed by a lid portion 5b of the bearing 5. Both ends of the rod-shaped heating body 4 are fixed to the shaft center portion by the lid portion 5b of the bearing 5. An elastic roller 2 is arranged in parallel with the heating roller 1, and the elastic roller 2
Is connected to a rotation driving means (not shown) such as a motor via a gear 6 and the like, and is rotationally driven in the arrow direction of FIG. A roller pressing means 7 composed of a spring is arranged on the outer periphery of the lid 5b of the bearing 5, and the roller pressing means 7 presses the heating roller 1 toward the elastic roller 2 side via the bearing 5. Contact. For this reason,
The rotational drive of the elastic roller 2 is transmitted to the heating roller 1, and the heating roller 1 is configured to be driven to rotate by the rotational drive of the elastic roller 2. Further, the rotary shaft portions projecting at both ends of the elastic roller 2 are rotatably attached to the support frame 8 of the heat fixing device through a means such as a bearing, and the cover body portion 5b of the bearing 5 is provided.
Is also rotatably attached to the support frame 8 of the heat fixing device through a slide groove provided on the outer periphery thereof.

The heat fixing device according to this embodiment operates as described below.

Electric power is supplied to the heating body 4 through the lid portion 5b of the bearing 5 serving as a heating body supporting portion to heat the heating body 4 to bring the heating roller 1 into a heating state, and then the rotation driving means ( When the elastic roller 2 is driven to rotate via a gear (not shown) and the gear 6, etc., the heating roller 1 which is in contact with the elastic roller 2 corresponding to the rotation of the elastic roller 2 also rotates at the same speed. At this time, a recording sheet (not shown) on which a toner image is formed between the heating roller 1 and the elastic roller 2.
When the sheet is conveyed, the toner image on the recording sheet is heated by the heat from the heating roller 1 (the transfer direction thereof is shown by an arrow A in FIG. 1A), and the heating roller 1 and the elastic roller 2 are heated. The pressure applied by the two rollers 1 and 2 when passing between the sheet and the sheet is fixed on the recording sheet.

Here, in this embodiment, the constituent members directly coupled to the heating roller 1 are the elastic roller 2 and the heating roller 1 which are arranged in parallel and close to the heating roller 1. It is only the bearings 5 arranged at both ends, the roller pressing means 7 directly connected to the bearings, and the supporting frame 8 of the heat fixing device. Therefore,
The heat generated by the heating body 4 is transferred to the elastic roller 2 direction (direction of arrow A) through the hollow cylindrical body 3 and the lid of the hollow cylindrical body 3 and the bearing 5 for fixing the toner image. Only those which are transmitted in the direction of the roller pressing means 7 and the supporting frame 8 of the heat fixing device (direction of arrow B) via the body portion 5b.

In this case, with respect to the heat of the heating roller 1 transmitted in the direction of the elastic roller 2 (direction of arrow A), the surface of the elastic roller 2 is covered with a heat insulating elastic material such as silicon rubber or fluorine rubber. Therefore, the heat of the heating roller 1 is blocked from being transferred on the surface, and is hardly transferred in the axial direction of the elastic roller 2. Therefore, the rotation driving portion of the elastic roller 2, for example, the gear 6
Even if these are not made of a heat insulating material, the heat of the heating roller 1 is not transferred to the rotary drive portion, and heat loss due to the transfer can be eliminated. At the same time, since it is not necessary to directly connect the rotary drive portion to the heating roller 1, heat transfer due to the direct connection is eliminated, and heat loss due to the transfer can be eliminated.

The heat of the heating roller 1 transmitted in the direction of the roller pressing means 7 and the supporting frame 8 of the heat fixing device (direction of arrow B) is the same as in the conventional heat fixing device described above. Although the transfer of heat cannot be prevented by any means, the heat insulation distance can be made considerably longer as compared with the sliding bearing that has been conventionally used as the structure of the bearing 5, so that the amount of heat can be increased accordingly. Loss can be reduced. Further, the bearing 5 used in this embodiment
Since the both end openings of the hollow cylindrical body 3 are sealed by the lid portion 5b, there is no heat radiated through the openings, and the heat loss due to the divergence can be reduced.

By the way, in this embodiment, since the rotation driving portion is not provided on the heating roller 1 side, it is sufficient to use the hollow cylindrical body 3 having a minimum length of about the width of the recording paper. Moreover, the thickness can be reduced. For this reason, the heat capacity of the hollow cylindrical body 3 becomes small, and the time until the temperature rises to the specified temperature after the heating of the heating body 4 is started can be shortened, and the energy such as electric power for keeping at a constant temperature is small. can do.

In this case, in this embodiment, if a heat (light) reflecting surface made of a means such as plating is formed on at least a part of the inner surface of the hollow cylindrical body 3, the heat generated by the heating body 4 can be generated. It becomes possible to uniformly transmit to the surface of the hollow cylindrical body 3 with high efficiency, and in particular, not only the inner surface of the hollow cylindrical body 3 but also the fitting of the bearing 5 fitted into both end portions of the hollow cylindrical body 3. By forming the heat (light) reflecting surface also on the surface of the hollow portion 5a on the inner side of the hollow cylindrical body 3, the heat generated by the heating body 4 can be evenly distributed on the surface of the hollow cylindrical body 3 with higher efficiency. It becomes possible to communicate. On the other hand, even if the inner surface of the hollow cylindrical body 3 and the surface of the fitting portion 5a on the inner side of the hollow cylindrical body 3 are painted black or their surfaces are roughened, the heat transfer efficiency is similarly improved. You can

Further, in this embodiment, as shown in FIG. 3, a heat (light) reflecting member 9 is arranged at a portion inside the hollow cylindrical body 3 on the opposite side of the elastic roller 2 to form a heating member. If the heat radiated to the heat (light) reflecting member 9 side is reflected by the heat (light) reflecting member 9 among the heat radiated from 4, the more heat is transferred to the elastic roller 2 direction. As a result, the heat utilization efficiency at the time of heat fixing can be further enhanced. Then, in this case, if the heat (light) reflecting member 9 is arranged so that heat (light) is concentrated on the insertion side of the recording paper 10, the hollow cylindrical body 3 in the insertion portion of the recording paper 10 will be described. Since the surface temperature becomes high, it becomes possible to perform heat fixing with higher efficiency.

Further, in this embodiment, at least one end of the hollow cylindrical body 3 is provided with a portion for increasing frictional resistance with the elastic roller 2 by means such as knurling, or If the substantially effective length of the elastic roller 2 is made longer than the substantially effective length of the hollow cylindrical body 3, the frictional engagement between the end portion of the elastic roller 2 and the end portion of the heating roller 1 during rotation. As a result, the rotation force of the elastic roller 2 can be sufficiently transmitted to the heating roller 1.

As described above, according to this embodiment, the heating roller 1 is only directly connected to the elastic roller 2 whose surface is made of a heat insulating material and the bearing 5 which is also made of a heat insulating material. Therefore, the heating roller 1 is maintained in a high thermal insulation state, and the heating roller 1 has a uniform heat generation distribution in the length direction. Therefore, most of the heat from the heating roller 1 is effectively used for heat fixing, and stable heat fixing can be performed with low power consumption, and the stable heat fixing can be performed with a simple configuration. Can be achieved.

Next, FIG. 4 is a sectional view showing the construction of one bearing portion of a second embodiment of the heat fixing device according to the present invention.

In FIG. 4, the same components as those shown in FIGS. 1 and 2 are designated by the same reference numerals.

The difference between the present embodiment and the above-mentioned first embodiment is the specific structure of the bearing 5. In the above-mentioned first embodiment, the fitting portion 5a of the bearing 5 is hollow in the heating roller 1. While it is configured to be fitted into the inner surface of the cylindrical body 3, in the present embodiment, the fitting portion 5a has the hollow cylindrical body 3
There is no difference in the other points.

Further, the operation of this embodiment is exactly the same as the operation of the above-mentioned first embodiment, and the effect of this embodiment is the same as the effect of the above-mentioned first embodiment. ,
All of these explanations are omitted.

However, in the present embodiment, when the hollow cylindrical body 3 is fitted into the fitting portion 5a of the bearing 5, the outer surface of the hollow cylindrical body 3 becomes a friction engagement surface, so that the above-mentioned first embodiment is used.
Compared with the above embodiment, it has advantages such as easy processing such as polishing.

Next, FIG. 5 is a sectional view showing the construction of one bearing portion of a third embodiment of the heat fixing device according to the present invention.

In FIG. 5, the same components as those shown in FIGS. 1 and 2 are designated by the same reference numerals.

The difference between the present embodiment and the first embodiment described above is that the specific construction of the bearing 5 is the same as in the first embodiment. The fitting portion 5a of the bearing 5 is hollow in the heating roller 1 in the first embodiment. While it is configured to be fitted into the inner surface of the cylindrical body 3, in the present embodiment, the fitting portion 5a has the hollow cylindrical body 3
There is no difference in the other points except that it is configured so as to be fitted on both the inner surface and the outer surface.

Also, the operation of this embodiment is exactly the same as the operation of the above-mentioned first embodiment, and the effect of this embodiment is the same as that of the above-mentioned first embodiment. ,
Again, these explanations are omitted here.

Next, FIG. 6 is a cross-sectional view showing an example of the state of the configuration of the heat fixing device according to the present invention during maintenance.

In FIG. 6, 11 is a fixed part, 12 is a movable part, 13 is a drive part, 14 is a rotating shaft, 15 is a spring material, and other components are the same as those shown in FIG. It is marked.

The fixed portion 11 includes the elastic roller 2, the drive portion 13 for rotationally driving the elastic roller 2, the spring material 15 and the like, and is always maintained in a fixed state. Further, the movable portion 12 includes the heating roller 1, the roller pressing means 7 and the like, and is normally moved and arranged at a position in contact with the upper side of the fixed portion 11 against the elasticity of the spring material 15. During maintenance, for example, when a recording paper jam occurs,
Due to the elasticity of the spring material 15, the spring material 15 is configured to rotate around the rotation shaft 14 in the direction of the arrow in FIG. Further, when the movable portion 12 moves in the direction of the retracted position, the power supply to the heating element 4 is interrupted, and the heating roller 1
The heating operation of is stopped.

According to the above construction, the driving portion 13 for rotationally driving the elastic roller 2 is arranged on the fixed portion 11 side, while the movable portion 12 side is arranged on the heating roller 1 side.
Since a drive unit for rotating and driving is not provided, the configuration on the movable unit 12 side is simplified, and it is extremely easy to provide a configuration for opening the portion including the heating roller 1 upward.

Next, FIG. 7 is a cross-sectional view showing an example of a plain paper facsimile apparatus equipped with the heat fixing device according to the present invention.

In FIG. 7, reference numeral 16 is a reading unit, 17 is a printing mechanism unit, 18 is an elastic roller arrangement unit of a heat fixing device, and 19 is a unit.
Is a heating roller arrangement portion of the heat fixing device, 20 is a control circuit portion, 21 is a power source portion, 22 is a paper feed cassette, and 23 is a paper discharge tray.

A reading unit 16 for reading an original to be transmitted is provided above the heating roller placement unit 19 of the heating and fixing device, and the heating roller placement unit 19 of the heating and fixing device heats the reading unit 16 together. It constitutes the movable part of the fixing device. An elastic roller arrangement portion 18 of the heat fixing device and the like are provided on the fixing portion side of the heat fixing device.

In this case, since the operation of the facsimile machine is clear, the description of the operation will be omitted.

By the way, since the heat fixing device according to the present invention has a high thermal efficiency, when the heat fixing device is used not only for the facsimile device but also for a printer, a copying machine, etc., the temperature of the heating roller 1 is a specified temperature. You can shorten the waiting time before rising to the conventional one, and at the same time,
It becomes possible to reduce power consumption during heating. In particular,
In a facsimile machine in which the waiting time from receiving communication information to recording is shortened, the use of the heat fixing device according to the present invention saves internal memory.
It is extremely effective.

The heat-fixing device according to the present invention can be applied not only to the above-mentioned facsimile device but also to other devices utilizing the electrophotographic recording system such as a printer and a copying machine. ..

[0062]

As described above, according to the present invention,
Since the elastic roller 2 and the bearing 5 made of a heat insulating material are only directly connected to the heating roller 1, the heating roller 1 is maintained in a high thermal insulation state, and the heating roller 1 has a heat generation distribution in the longitudinal direction. Becomes uniform. Therefore, most of the heat from the heating roller 1 is effectively used for heat fixing, and stable heat fixing can be performed with low power consumption, and the stable heat fixing can be achieved with a simple configuration. There is an effect.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a heat fixing device according to the present invention.

FIG. 2 is an enlarged view showing the configuration of one bearing portion in the embodiment of FIG.

FIG. 3 is a cross-sectional view showing an example of a structure in which a heat reflection member is mounted inside a heating roller.

FIG. 4 is a configuration diagram showing a second embodiment of a heat fixing device according to the present invention.

FIG. 5 is a configuration diagram showing a third embodiment of a heat fixing device according to the present invention.

FIG. 6 is a transverse cross-sectional view showing an example of the configuration of the heat fixing device according to the present invention during maintenance.

FIG. 7 is a cross-sectional view showing an example of a plain paper facsimile apparatus including a heat fixing device according to the present invention.

FIG. 8 is a cross-sectional view showing an example of the configuration of one bearing portion of a conventional heat fixing device.

FIG. 9 is a cross-sectional view showing an example of the configuration of one bearing portion of another conventional heating and fixing device.

[Explanation of symbols]

 1 Heating Roller 2 Elastic Roller 3 Hollow Cylindrical Body 4 Heating Body 5 Bearing 5a Bearing Fitting Part 5b Bearing Lid Part 6 Gear 7 Roller Pressing Means (Spring) 8 Supporting Frame for Heat Fixing Device 9 Heat (Light) Reflecting member 10 Recording paper 11 Fixed part 12 Movable part 13 Driving part 14 Rotating shaft 15 Spring material 16 Reading part 17 Printing mechanism part 18 Elastic roller arranging part of heat fixing device 19 Heating roller arranging part of heat fixing device 20 Control circuit 21 Power Supply 22 Paper Feed Cassette 23 Paper Ejection Tray

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Teruaki Mitsuya 4026 Kuji Town, Hitachi City, Hitachi, Ibaraki Prefecture Hitachi Research Laboratory, Hiritsu Manufacturing Co., Ltd.

Claims (14)

[Claims] 1. An unfixed toner image on a recording sheet is recorded on the recording sheet by using a heating roller composed of a hollow cylindrical body having a heating element inside and an elastic roller arranged in parallel and close to the heating roller. In a heat fixing device for heating and fixing, the hollow cylindrical body is formed by a bearing of a heat insulating material having a fitting portion into which both ends of the hollow cylindrical body are fitted and a lid portion in which both end openings of the hollow cylindrical body are sealed. Retained,
Further, the heat fixing device is characterized in that the elastic roller constitutes a driving roller. 2. The heat fixing device according to claim 1, wherein the fitting portion of the bearing of the heat insulating material is configured to hold the inner surfaces of both ends of the hollow cylindrical body in contact with each other. 3. The heat fixing apparatus according to claim 1, wherein the fitting portion of the bearing of the heat insulating material is configured to hold the outer surfaces of both ends of the hollow cylindrical body in contact with each other. 4. The heat fixing device according to claim 1, wherein the fitting portion of the heat insulating material bearing is configured to hold the inner and outer surfaces of both ends of the hollow cylindrical body in contact with each other. 5. The heat fixing device according to claim 1, wherein the bearing of the heat insulating material is configured to hold a heat generating element inside the hollow cylindrical body. 6. The heating according to claim 1, wherein the inner surface of the hollow cylinder and the surface of the bearing of the heat insulating material on the inner side of the hollow cylinder are heat reflecting surfaces. Fixing device. 7. The driving peripheral speed of the elastic roller is set so that the peripheral speed of the heating roller is equal to or slightly slower than the surface speed of the photosensitive member. 7. The heat fixing device according to any one of 6 above. 8. The unevenness for increasing frictional engagement between the heating roller and the elastic roller is provided on at least one end of the heating roller. The heat fixing device according to any one of claims. 9. The heat-fixing device according to claim 1, wherein the heat-rolling device is arranged so that the heat-roller can be moved to a retracted position with respect to the fixed elastic roller during maintenance. A heating and fixing device as described in 1. 10. The heat fixing device according to claim 9, further comprising means for stopping the heating operation of the heating element when the heating roller moves to the retracted position. 11. The heat fixing device according to claim 1, further comprising a pressing unit that presses the heating roller toward the elastic roller and is in contact with the bearing. .. 12. The heat fixing device according to claim 1, wherein the effective effective length of the elastic roller is slightly longer than the effective effective length of the heating roller. 13. An electrophotographic apparatus comprising at least a photoconductor, a charging device, an exposing device, a developing device, a transfer device which are sequentially arranged along the photoconductor, and a fixing device which is arranged in a conveyance path of a recording sheet. In a recording apparatus, the fixing device is the fixing device.
An electrophotographic recording apparatus, characterized in that the above described heat fixing device is used. 14. The electrophotographic recording device is a printer,
14. The electrophotographic recording apparatus according to claim 13, wherein the electrophotographic recording apparatus is one of a copying machine and a facsimile machine.