JP2000274426A - Heating device and fixing device having the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an economical and highly reliable heating device capable of obtaining the desired generation of heat at low power consumption by preventing the deflection of a heating member and shortening rising time with a relatively simple structure, and a fixing device capable of obtaining a high image quality when this heating device is applied thereto. SOLUTION: In a heating device 100 having a pressing member 3 disposed to be abutted on a pressure roller 2 side pressed into contact with a heating member 1 in the inner peripheral surface of a cylindrical heating member and passing a sheet 17 between the heating member 1 and the pressure roller 2, the pressing member 3 is in contact with a position other than a portion A corresponding to a press-contact portion between the heating member 1 and the pressure roller 2 in the inner peripheral surface of the heating member 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating apparatus having a heating member such as a heating roller and a pressure roller, and a sheet passing between the heating member and the pressure roller for heating. Heating device having a pressing member for preventing excessive deformation of the heating member due to pressure contact with a pressure roller, and wrinkling of a sheet such as a bill and a fixing device in an image forming apparatus such as an electrophotographic copying machine, a printer, and a facsimile having the same. It relates to a removing device.

[0002]

2. Description of the Related Art In the above-described image forming apparatus, generally,
The unfixed toner image on the sheet as the recording paper is fixed on the recording paper by heating and melting. This heating and melting is performed by passing a recording paper with an unfixed toner image adhered between these rollers in a heating device called a heating roller system having a heating roller as a heating member and a pressure roller pressed against the heating roller. Do. Such a heating device is generally used for reasons such as safety and stability.

A typical configuration of a heating device of a heating roller type is such that a pressure roller is disposed in contact with a heating roller having a halogen lamp as a heat source therein.
The temperature of the heating roller is raised to a predetermined temperature by the heat of the halogen lamp, and the recording paper having the unfixed toner image adhered is passed through a mutual pressing portion called a nip portion which is a pressing portion between the heating roller and the pressing roller. The sheet is conveyed, and the toner image is fixed on the recording medium.

Generally, an aluminum or iron-based metal roller having a thickness of 1 mm or more is used as a heating roller, and a pressure roller generally has a metal core covered with rubber as an elastic body. However, in this configuration, since the heat roller has a large heat capacity, it takes several minutes to raise the temperature to a temperature necessary for melting the toner, and the startup time after turning on the power or canceling the standby mode is long. In order to ensure the operability of prompt recording start after the start, it is necessary to supply power to the fixing unit and maintain the heating roller at a constant temperature even in a standby mode in which a recording operation is not performed, that is, in a standby mode. However, the standby power consumption occupies a large proportion of the total power consumption of the image forming apparatus, which hinders reduction in power consumption, which has recently been an issue, such as compliance with energy conservation regulations in various countries.

In order to reduce the power consumption of the image forming apparatus, it is effective to reduce the power supply at the time of standby and to reduce the temperature rise time when the heating roller rises. It is effective to reduce the heat capacity of the heating roller to reduce the power supply during standby and to shorten the heating time. To reduce the volume of the heating roller, it is necessary to use a roller. It is effective to reduce the heat capacity by reducing the diameter and the thickness of the film. However, in order to satisfactorily fix unfixed toner, a sufficiently large nip width and uniform nip width in the longitudinal direction of the roller are required to secure a predetermined heating time, but in order to obtain a sufficient nip, When a pressing force is applied by the pressing roller, the pressing force is applied to the heating roller, so that the heating roller having a reduced volume is held in a deflected state during non-printing,
It is a problem in terms of mechanical strength, such as deterioration and breakage of the heating roller.In addition, since the heating roller bends in the longitudinal direction, the nip width is significantly different between both ends and the center of the roller, and the image quality obtained is reduced. Problems arise. In other words, in the conventional heating device, when the diameter is reduced and the wall thickness is simply advanced and a large pressing force is applied to secure a wide nip width, the nip width is significantly different between both ends and the center of the heating roller. There is a problem that it is difficult to obtain good image quality due to different fixing properties depending on paper portions.

Therefore, Japanese Patent Application Laid-Open No. Hei 9-114296 proposes a technique for reducing the deflection of a thin-walled heating roller having a fast rise. This technique is to provide a pressing member that is pressed against and abuts on the inner peripheral surface of the heating roller and corresponding to the pressing portion, and bears the pressing force of the pressing roller against the heating roller.
Excessive bending of the heating roller is reduced, and both low heat capacity of the heating roller and prevention of excessive bending are achieved. Also,
Japanese Patent Application Laid-Open No. 10-48983 also proposes a technique having a similar pressing member that is pressed against and abuts on a portion corresponding to the pressed portion of the inner peripheral surface of the heating roller during standby.

[0007]

However, in any of the above-mentioned techniques, the heating time is relatively short because the heating roller is sufficiently thin, but the pressing member is in contact with the portion corresponding to the pressure contact portion. In addition, heat energy for fixing is transmitted not only to the toner and the sheet but also to the pressing member, and a loss is caused by the pressing member, so that there is a problem that efficiency is low. This problem is conspicuous in the former technique, particularly in fixing immediately after startup, in which the temperature of the pressing member is low, and causes a problem that the quality of a fixed image is deteriorated because the heating roller is a thin roller having a small heat capacity.
Further, in the latter technique, there is a problem that a mechanism for supporting the pressing member to be able to freely contact and separate from the heating roller is complicated. Such a problem is caused not only when the heating device is used in the fixing device provided in the above-described image forming apparatus,
The same applies, for example, when a wrinkle removing device for a sheet such as a banknote is used, the wrinkles of the sheet cannot be sufficiently removed.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and achieves desired heat generation with low power consumption by shortening the rising time while preventing the deflection of the heating roller with a relatively simple configuration, and is economical and reliable. The present invention provides a heating device having a high image quality and a fixing device capable of obtaining high image quality when the heating device is applied to the fixing device.

[0009]

According to the first aspect of the present invention,
A heating member having a cylindrical shape, a pressing roller pressed against the heating member, and a pressing member disposed in contact with the inner peripheral surface of the heating member on the pressing roller side; In a heating device that passes and heats a sheet between rollers, the pressing member abuts on a position other than a portion of the inner peripheral surface of the heating member corresponding to a pressure contact portion between the heating member and the pressure roller. It is characterized by having.

According to a second aspect of the present invention, in the heating device of the first aspect, the pressing member is in contact with the inner peripheral surface of the heating member at a plurality of contact positions.

According to a third aspect of the present invention, in the heating device according to the second aspect, the pressing member contacts the inner peripheral surface of the heating member at an upstream side of the pressing portion in a rotation direction of the heating member. And a second pressing member that abuts on the inner peripheral surface of the heating member on the downstream side of the pressing portion in the rotation direction of the heating member, and the contact position is such that the first pressing member is It is characterized by comprising a first contact position in contact with the inner peripheral surface of the heating member, and a second contact position in which the second pressing member contacts the inner peripheral surface of the heating member.

According to a fourth aspect of the present invention, in the heating device of the third aspect, a distance between the press contact portion and the first contact position is larger than a distance between the press contact portion and the second contact position. It is characterized by the following.

According to a fifth aspect of the present invention, in the heating device of the third or fourth aspect, the first pressing member and / or the second
Is a rotating body parallel to the heating member.

According to a sixth aspect of the present invention, in the heating device according to the second aspect, the pressing member contacts the inner peripheral surface of the heating member upstream of the pressing portion in a rotation direction of the heating member. And a second pressing portion that abuts on the inner peripheral surface of the heating member on the downstream side of the pressing portion in the rotation direction of the heating member. It is characterized by comprising a first contact position in contact with the inner peripheral surface of the heating member and a second contact position in which the second pressing portion contacts the inner peripheral surface of the heating member.

According to a seventh aspect of the present invention, in the heating device of the sixth aspect, a distance between the press contact portion and the first contact position is larger than a distance between the press contact portion and the second contact position. It is characterized by the following.

According to an eighth aspect of the present invention, in the heating device of the sixth or seventh aspect, the pressing member has a slit between the first pressing portion and the second pressing portion. .

According to a ninth aspect of the present invention, in the heating device according to the sixth or seventh aspect, the pressing member is characterized in that at least a portion between the first pressing portion and the second pressing portion is heat-permeable. Features.

According to a tenth aspect of the present invention, in the heating device according to any one of the third to ninth aspects, the pressing member at the first contacting position and the pressing member at the second contacting position are provided. Are set such that heat absorption by the pressing member at the first contact position is smaller than heat absorption by the pressing member at the second contact position.

According to an eleventh aspect of the present invention, in the heating device according to any one of the first to tenth aspects, the pressing member has a heat insulating member for suppressing heat absorption by the pressing member. And

According to a twelfth aspect of the present invention, there is provided the heating apparatus according to any one of the first to eleventh aspects, wherein a sheet is passed between the heating member and the pressure roller to heat the sheet. And a fixing device for heating and fixing the toner image on the sheet.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 denotes a hollow cylindrical heating roller as a heating member, reference numeral 2 denotes a pressing roller which presses against the heating roller 1, and reference numeral 3 denotes a pressing roller 2 on the inner peripheral surface of the heating roller 1. Pressing member inserted so as to abut the side, reference numeral 1
Reference numeral 00 denotes a heating device having a heating roller 1, a pressure roller 2, and a pressing member 3, respectively. Hereinafter, the heating device 10
Although a case where 0 is used as a fixing device will be described, the heating device 100 can be appropriately applied to a wrinkle removing device for a sheet such as a bill.

The heating roller 1 is supported by a stationary member 15 as a side plate via a cylindrical bearing 4 and is driven to rotate by a driving means (not shown) via a gear 5 provided at an end thereof. The heating roller 1 is formed by forming a release layer of PFA which is a fluororesin on the outer surface of an iron base material. The base material may be made of aluminum or other metal instead of iron. The release layer may be made of a fluororesin such as PTFE as long as it has good releasability such as a molten toner or ink, or may be made of silicone rubber. And the like. The heating member may be a belt-shaped endless member as long as it is cylindrical, and may not be a cylindrical member such as the heating roller 1. In this case, the axial direction of the heating roller 1, that is, the direction perpendicular to the paper surface of FIG. 2 and the like corresponds to the width direction of the belt-shaped heating member. Hereinafter, the case where the heating member is the heating roller 1 will be described. However, the heating roller 1 can be replaced with a belt-shaped member, and the axial direction of the heating roller 1 and the width direction of the belt-shaped heating member are set in the axial direction. This will be described.

The heating roller 1 has a well-known rod-shaped heater 6 which is a halogen lamp as a heat source inserted at the center of rotation, and is heated by the heat generated by the heater 6. As a heat source,
Not only halogen lamps, but also those in which an insulating layer such as an oxide film such as a ceramic layer, a heat-resistant polymer layer, or alumite is formed on the heating roller 1, or those in which an insulator such as ceramic, glass, or heat-resistant plastic is formed, A heating element such as a ceramic heating element, nichrome, Ta2N, RuO2, Ag / Pd, etc., is formed into a sheet or line by thermal spraying, coating, printing, etc., and a sheet heating element or a line which generates heat when energized. A heating element may be used, or a coil may be wound around an iron core to use induction heating.

The pressure roller 2 is heated by an urging means 11 provided on a bearing 10 at the end of a center shaft 9 of the heating roller 1.
At a constant pressure, and is supported by the stationary member 15 with a certain degree of freedom in the vertical direction by a long hole provided in the stationary member 15 as a side plate. The pressure roller 2 has a cored bar 12 integrally having a central shaft 9 and an elastic layer 13 formed around the cored bar. The metal core 12 is made of iron, but may be made of aluminum or another metal, or may be made of an alloy of these metals. The elastic layer 13 has a heat resistant material such as silicon rubber. High materials are used. A release layer is formed on the surface of the elastic layer 13 in consideration of the releasability of the molten toner, ink, and the like. In this embodiment, a spring is used as the urging means, but another elastic body may be used.

The pressing member 3 is made of iron, but may be formed of a metal such as aluminum or a nonmetal such as ceramic or plastic. In consideration of high Young's modulus, heat resistance and cost, it is desirable that the metal is made of aluminum, another metal, or an alloy of these metals, in addition to iron in this embodiment. The length of the pressing member 3 is longer than that of the heating roller 1, and is disposed so as to penetrate the heating roller 1. The pressing member 3 is supported by a stationary member 15 as a side plate via bearings 7 provided at both ends of the pressing member 3. Pressing member 2
Is longer than the heating roller 1 and is entirely in contact with the inner peripheral surface of the heating roller 1 in the axial direction. Compared to the case where the pressure roller 1 alone receives the pressure contact force from the pressure roller,
The amount of deflection of the heating roller 1 decreases.

As shown in FIG. 2, the pressing member 3 is provided on an inner peripheral surface of the heating roller 1 except for a region A which is a portion corresponding to a nip portion which is a pressure contact portion between the heating roller 1 and the pressure roller 2. Abuts the position. Note that the heater 6 is not shown in FIGS. The contact portion of the pressing member 3 with the heating roller 1 may be located upstream or downstream in the direction A indicated by the arrow a which is the rotation direction of the heating roller 1 with respect to the region A. Considering that the temperature of the heating roller 1 heated by the heating is reduced, the contact portion is moved in the direction a with respect to the region A as in the present embodiment.
Is desirably provided in the vicinity of the downstream side. This is because, in order to increase the heating time of the heating roller 1 by the heater 6, it is desirable that the distance from the contact portion to the region A is large in the rotational movement distance of the heating roller 1. The pressing member 3 has a semicylindrical cross section, and the portion forming an arc is the heating roller 1.
, So that the rotation of the heating roller 1 is not hindered, and the heating roller 1 is not damaged or damaged.

In FIG. 2, reference numeral 17 denotes a heating device 10.
0 indicates a sheet such as a sheet carrying unfixed toner 18 when used as a fixing device as in this embodiment, and a sheet such as a banknote when used as a wrinkle removing device. A guide for guiding the sheet 17 to the nip is shown. In the present embodiment, other than the above, detecting means (not shown) for detecting the size and the number of sheets passing between the heating roller 1 and the pressure roller 3 by inputting fixing information by an operator's instruction or a known mechanism. And

Since the present embodiment has the above configuration,
A copy start button provided on an image forming apparatus (not shown) having a fixing device using the heating device 100 is pressed,
Alternatively, when fixing information is input and fixing is started, the sheet 17 is supplied into the image forming apparatus main body,
A predetermined image is formed on a photoreceptor provided in the image forming apparatus by an electrostatic recording process, and is transferred onto a supplied sheet, whereby an unfixed toner image is formed on the sheet 17. After the heating roller 1 reaches the fixing temperature, the sheet 17 on which the unfixed toner image is formed is conveyed to the nip by the guide 16, and the sheet and the unfixed toner are passed through the nip and heated and pressurized.
The unfixed toner image on the sheet is heat-fixed to the sheet.

Since the pressing member 3 bears the pressing force of the pressing roller 2 against the heating roller 1, the strength of the heating roller 1 can be reduced. Therefore, the thickness of the heating roller 1 is reduced to reduce the heat capacity. Therefore, the heating time can be shortened, the rising time can be shortened, and the waiting time of the user can be shortened. Further, since the pressing member 3 is in contact with the inner peripheral surface of the heating roller 1 in a region other than the region A, when the temperature of the heating roller 1 rises, the thermal energy of the nip portion is absorbed by the pressing member 2 and the temperature of the nip portion is reduced. Since the heat energy supplied by the heater 6 is efficiently supplied to the sheet 17 and the unfixed toner 18 without a problem of lowering, the heating time can be further reduced, and the rise time can be further reduced. The waiting time of the user can be shortened. Further, since the pressing member 3 is disposed on the downstream side in the direction a with respect to the area A, even if the heat energy of the heating roller 1 is absorbed by the pressing member 3 and the temperature of the heating roller 1 decreases, the heating roller 1
Is heated by the heater sufficiently until the portion where the temperature is lowered by rotating in the direction a reaches the nip portion, so that fixing failure does not occur.

The pressing member 3 is a member other than the region A,
May be in contact with the inner peripheral surface of the heating roller 1 at two or more contact positions.
FIG. 3 shows a case where the pressing member 3 is in contact with the inner peripheral surface of the heating roller 1 at two points in the area A, near the upstream side and near the downstream side in the direction a. The pressing member 3 contacts the inner peripheral surface of the heating roller 1 at a first contact position near the upstream side of the area A in the direction a.
And a second pressing member 3b contacting the inner peripheral surface of the heating roller 1 at a second contact position near the downstream side of the area A in the direction a. Thus, the pressing member 3
However, by contacting the heating roller 1 on both sides of the region A, the apparent radius in the vicinity of the nip portion becomes larger and the nip width becomes wider than when the pressing member 3 contacts the heating roller 1 at one place. Even if the diameter of the heating roller 1 is small, the nip width is widened, and the heat energy supplied to the sheet can be increased.

FIG. 3 shows that the pressing member 3 is in the area A
In contact with the heating roller 1 on both sides of the
In this case, the distance from the center of the region A to the first contact position and the second contact position is substantially the same, but as shown in FIG. An angle between a straight line connecting the rotation center and a straight line connecting the first contact position and the rotation center of the heating roller 1 is θ1, and connects the center of the area A in the direction a and the rotation center of the heating roller 1 in the direction a. Assuming that an angle between a straight line and a straight line connecting the second contact position and the rotation center of the heating roller 1 is θ2, approximately θ1 = θ
2 so that the distance from the center of the region A in the direction a to the first contact position is larger than the distance from the center of the region A in the direction a to the second contact position. You may do it.

Thus, the pressing members 3a and 3b
By contacting the heating roller 1 on both sides of the region A, the apparent radius in the vicinity of the nip portion can be increased as compared with the case where the pressing member 3 contacts the heating roller 1 at one place, and the pressing member 3a can be heated. Even if the temperature of the roller 1 is lowered, the portion where the temperature is lowered is sufficiently raised before reaching the nip portion, so that the amount of heat required for fixing can be secured, and The pressure from the roller 2 is mainly received by the pressing member 3b, and the deflection of the heating roller 1 can be kept small.

The pressing member 3 is not in the shape of a cross section as shown in FIGS. 2 to 4, but is arranged in parallel with the heating roller 1, that is, in parallel with the axial direction, as shown in FIG. It is a rotating body having a cylindrical shape, and can be driven to rotate by the heating roller 1 or driven to rotate in accordance with the rotation speed of the heating roller 1. FIG. 5 shows the pressing member 3.
Is composed of a first pressing member 3a and a second pressing member 3b that are in contact with the heating roller 1 on both sides of the region A, and the first contact position and the second contact position are determined from the center of the region A in the direction a. 2 shows a case where the distance to the contact position is substantially the same, but as shown in FIG. 2, the contact may be made on one side of the area A, or as shown in FIG. The distance from the center of the region A to the first contact position may be larger than the distance from the center of the region A in the direction a to the second contact position. By eliminating the sliding friction with the heating roller 1 using the pressing member 3 as a rotating body, the rotational load on the drive source of the heating roller 1 can be reduced.

In this embodiment having a heater 6 inserted into the heating roller 1 as a heat source, in particular, when the pressing member 3 rotates, the surface of the pressing member 3 heated by the heater 6 is applied to the heating roller 1. The non-rotating or fixed type pressing member 3 shown in FIGS.
Compared to the case of using the heat roller, the heat roller 1 advantageously works to raise the temperature of the heating roller 1 and is particularly effective for raising the temperature of the heating roller 1 immediately after startup. This is because both the heating roller 1 and the pressing member 3 are hidden from the heater 6 at the contact position, so that when the fixed type pressing member 3 is used, the pressing member 3 at the contact position is used.
Is raised by heat transfer from the heater 6 side and heat supply from the heating roller 1, the pressing member 3 prevents the temperature of the heating roller 1 from rising at the time of rising, but the pressing member 3 Then, since the heated and high temperature surface of the pressing member 3 comes into contact with the heating roller 1 by rotation,
This is because the pressing member 3 is prevented from absorbing the heat energy of the heating roller 1.

As shown in FIG. 7, when the pressing member 3 comes into contact with the inner peripheral surface of the heating roller 1 at a plurality of abutting positions, the pressing member 3 may have a semicircular cross section or a circular cross section. They can be used in combination. Also in this case, considering that the temperature of the heating roller 1 at the contact position is lowered and that the lowered temperature portion needs to be raised before reaching the nip portion, the region A is located on the upstream side in the direction a with respect to the region A. Arranging the pressing member having a circular cross section, and the distance from the center of the region A in the direction a to the first contact position is larger than the distance from the center of the region A in the direction a to the second contact position. It is also desirable to make it larger.

When the pressing member 3 contacts the inner peripheral surface of the heating roller 1 at a plurality of contact positions, the pressing member 3a disposed on the upstream side in the direction a with respect to the area A, and the pressing member 3a disposed on the downstream side. Shape and / or material of the pressing member 3b
Is desirably set so that the heat absorption by the pressing member 3a at the contact position is smaller than the heat absorption by the pressing member 3b at the second contact position. Region A in direction a
The heating roller 1 whose temperature has been decreased by the pressing member 3b disposed downstream of the heating roller 1 may have a large thermal conductivity because it has room to heat up to reach the nip portion, but the heating roller 1 may have a large thermal conductivity. Unless the thermal conductivity of the pressing member 3a disposed on the upstream side of the region A is reduced, heat is taken from the heating roller 1 and the temperature in the nip portion is reduced, thereby increasing the temperature raising time. As described above, it is desirable that the heating member 1 take less heat energy than the pressing member 3b disposed downstream. for that purpose,
When aluminum having good thermal conductivity is used for the pressing member 3b, a material such as iron having a lower thermal conductivity than aluminum is used as the material of the pressing member 3a, or a heat insulating material such as silicon rubber is used. You can also
The width of the pressing member 3a in the direction a can be made smaller than the width of the pressing member 3b in the direction a, and the volume of the pressing member 3a can be made smaller than the volume of the pressing member 3b. By doing so, the transmission of heat energy in the axial direction of the heating roller 1, that is, in the longitudinal direction is improved,
Temperature uniformity in the longitudinal direction of the heating roller 1 is improved.

Conventionally, it has been difficult to make the temperature distribution in the axial direction of the heating roller and the pressure roller uniform in the heat fixing device having a fast temperature rising time as in the present invention. The unfixed toner and the non-fixed toner are applied to the surface of the recording medium at the passage portions of both rollers through which a recording medium (hereinafter, referred to as a small size medium) having a relatively small size in the axial direction, that is, a width direction, of both rollers passes. Heat is consumed for heating the recording medium having
Since heat is not deprived by the recording medium in the non-passing portion other than the passing portion, the heat of the heating roller accumulates and the temperature of the nip portion of the non-passing portion is maintained at a predetermined temperature. The temperature becomes higher than the temperature, and a so-called non-passing portion temperature rise occurs. Therefore, if the recording medium passes through a recording medium having a larger width (hereinafter, referred to as a large-sized recording medium) after continuously passing through the small-sized recording medium (for example, continuously passing through a B5-sized recording medium and then passing through an A4-sized recording medium) If you do),
Fixing unevenness and wrinkles occur in large-sized bodies, and the toner in the portion corresponding to the non-passing portion of the unfixed toner image is excessively melted, adheres to the fixing roller, and stains the surface of the recording medium. Had occurred. Further, when a large temperature difference occurs between the non-passing portion and the passing portion, there is also a problem that distortion occurs due to a difference in thermal expansion between the high-temperature portion and the low-temperature portion, resulting in deterioration. In particular, in the case of a heating roller in which a heating resistor is formed on the surface of a glass or ceramic pipe, the diameter of the heating roller differs between the passing portion and the non-passing portion due to thermal expansion due to a rise in the temperature of the non-passing portion. There is also a problem of being damaged. However, the transmission of heat energy in the longitudinal direction of the heating roller 1 is improved at a low cost without adding any special means by such a pressing member,
By improving the temperature uniformity of the heating roller 1 in the longitudinal direction, such a problem is solved. Therefore, the pressing member 3
a, 3b, the length of at least the pressing member 3b in the axial direction of the heating roller 1, that is, in the direction perpendicular to the plane of FIG. 2 to FIG. It is desirable to arrange so that it straddles.

In order to raise the temperature of the heating roller 1 quickly, the pressing member 3 contacts the heating roller 1 and the heating roller 1
Since it is effective to suppress the temperature from being lowered, the pressing member 3 is, as shown in FIGS.
It is desirable to have a heat insulating member 19 for suppressing heat absorption by the pressing member 3. The pressing member 3 shown in FIGS. 8 to 10 is obtained by integrating a heat insulating member 19 made of a material having a lower thermal conductivity than the metal core 20 with the metal core 20 described above. The heat insulating member 19 is formed of a phenol resin which is a heat-resistant resin, but may be another heat-resistant resin, or may be a heat-resistant elastic material such as silicon rubber or fluorine rubber in addition to an asbestos-like material. It may be.

The pressing member 3 shown in FIG. 8 has a semi-cylindrical cross section, and has a portion in contact with the heating roller 1 formed by a heat insulating member 19. The heat insulating member 3 is fixed to the surface such that the arc-shaped surface faces outward. The pressing member 3 shown in FIG.
The heat insulating member 19 of the pressing member 3 shown in FIG. 8 is added with a heat insulating member 19 that covers the other side of the quadrangular core 20, thereby suppressing the absorption of the heat energy generated by the heater 6 and correspondingly. This contributes to an increase in the temperature of the heating roller 1. The pressing member 10 shown in FIG. 10 has a circular cross section, and the circumferential surface of a cylindrical
9 covered. Thereby, it is possible to suppress the heat absorption when contacting the heating roller 1 and the absorption of the thermal energy generated by the heater 6. The heat insulating member 19 is a metal core 20
They may rotate integrally with each other, or may rotate independently.

When the pressing member 3 has the heat insulating member 19,
The heat insulating member 19 may have a length shorter than the length of the heating roller 1 and fit inside the heating roller 1, or a length longer than the heating roller 1 and having both ends exposed from the heating roller 1. To avoid stress concentration in the part,
It is desirable to arrange the heating roller 1 so as to be shorter than the length of the heating roller 1 and to fit inside the heating roller 1. Also, the heat insulating member 19
May be provided inside the pressing member 3 so as to substantially reduce the heat capacity. However, it is considered that heat absorption when contacting the heating roller 1 and absorption of heat energy generated by the heater 6 are suppressed. In this case, it is desirable that the heat insulating member 19 be formed as an outer layer when the pressing member is used.

FIGS. 3 to 7 show a case where the pressing member 3 comprises a plurality of members when the pressing member 3 contacts the inner peripheral surface of the heating roller 1 at a plurality of contact positions. 11, one pressing member 3 as shown in FIG.
A first pressing portion 3c that contacts the inner peripheral surface of the heating roller 1 at a first contact position near the upstream side of the region A in the direction a, and a second pressing portion 3c near the downstream side of the region A in the direction a. The second contacting the inner peripheral surface of the heating roller 1 at the contact position
May be provided. The first pressing portion 3c and the second pressing portion 3d are connected at both ends. The pressing member 3 shown in FIG. 11 has a slit 21 between the first pressing portion 3c and the second pressing portion 3d,
The pressing member 3 shown in FIG. 12 has a heat permeable member 22 between the first pressing portion 3c and the second pressing portion 3d.
The slit 21 and the member 22 contribute to the heat energy of the heater 6 heating the region A. The shape of the slit 21 and the member 22 and the material of the member 22 include heating the region A and the nip portion. Are selected to ensure the temperature rise in Further, in these pressing members 3, as shown in FIG. 4 and the like, the distance between the nip portion and the first contact position is set to be larger than the distance between the nip portion and the second contact position. Alternatively, a configuration having a heat insulating member as shown in FIG.

Although the present embodiment has been described above, the pressing member 3 is fixed at a constant pressure necessary and sufficient to prevent the excessive deflection of the heating roller 1 to prevent the heating roller 1 from being deteriorated or damaged. It is. As the sheet, in addition to ordinary paper, an envelope, cardboard, or an OHP sheet can be used.
The driving roller may be the pressure roller 3 instead of the heating roller 1. By using a combination of the heating roller and the pressure roller as a driving roller and a driven roller, when the heating device is used as a fixing device, it is undecided. Fixing can be performed without disturbing the formed toner image. Heating roller 1 and pressure roller 2
The position other than the portion corresponding to the pressure contact portion includes a position that does not excessively hinder the temperature of the heating roller 1 or absorbs heat energy in the pressure contact portion. ADVANTAGE OF THE INVENTION According to the sheet wrinkle removal apparatus which has a heating apparatus to which this invention is applied, wrinkles can be extended efficiently and favorably. The heating device and the fixing device to which the present invention is applied can be applied to an image forming apparatus such as a copying machine, a fax, and a printer. In this case,
The image forming apparatus is capable of obtaining a high quality formed image with energy saving.

[0043]

According to the first aspect of the present invention, a cylindrical heating member, a pressure roller that presses against the heating member, and an abutting arrangement are provided on the inner peripheral surface of the heating member on the side of the pressure roller. A heating member that passes a sheet between the heating member and the pressure roller to heat the heating member. Since it is in contact with a position other than the part corresponding to the pressure contact part with the roller, it is possible to prevent the bending of the heating member with a relatively simple configuration while reducing the thickness of the heating member, preventing the damage of the heating member As a result, the life of the device can be extended, and the pressing member corresponds to the press-contact portion immediately after the start-up of the device in which the temperature of the heating member has sufficiently risen but the temperature of the pressing member has not risen or in other cases. Reduce the temperature of the part heating element Since there is no Rukoto it can be shortened waiting time of the user by shortening the rise time, thus obtained the desired heating with low power consumption, economy and reliability to provide a high heating device.

According to the second aspect of the present invention, in the heating device according to the first aspect, the pressing member contacts the inner peripheral surface of the heating member at a plurality of contact positions. It is possible to provide a heating device capable of distributing the pressing force applied by the pressing roller in a distributed manner, balancing the pressing force load, and favorably pressing the sheet at the pressing portion.

According to a third aspect of the present invention, in the heating device according to the second aspect, the pressing member abuts on the inner peripheral surface of the heating member on the upstream side of the pressing portion in the rotation direction of the heating member. A first pressing member, and a second pressing member that abuts on the inner peripheral surface of the heating member on the downstream side of the pressing portion in the rotation direction of the heating member,
The contact position includes a first contact position where the first pressing member contacts the inner peripheral surface of the heating member, and a second contact position where the second pressing member contacts the inner peripheral surface of the heating member. Since the contact portion is provided, the width of the pressure contact portion can be widened even when the diameter of the heating member is small, and a heating device capable of sufficiently supplying heat to a sheet or a toner image can be provided.

According to a fourth aspect of the present invention, in the heating device of the third aspect, the distance between the press contact portion and the first contact position is equal to the distance between the press contact portion and the second contact position. Therefore, even if the pressing member lowers the temperature of the heating member at the contact position, the temperature of the portion where the temperature has decreased is sufficiently increased by the time the pressure member reaches the pressure contact portion. Therefore, it is possible to provide a heating device capable of securing a necessary amount of heat.

According to the fifth aspect of the present invention, in the heating device according to the third or fourth aspect, the first pressing member and / or the second pressing member is a rotating body parallel to the heating member. It is possible to reduce the rotational resistance of the heating member and the pressure roller, and to obtain a stable rotational drive between the heating member and the pressure roller with a small rotational load. A long-life heating device that can save energy and save heat, prevent the heating member from being scratched or damaged, and reduce the generation of powder such as metal due to wear of the heating member and pressing member. Can be provided.

According to a sixth aspect of the present invention, in the heating device according to the second aspect, the pressing member contacts the inner peripheral surface of the heating member at an upstream side of the pressing portion in a rotation direction of the heating member. A first pressing portion, and a second pressing portion that abuts on the inner peripheral surface of the heating member on the downstream side of the pressing portion in the rotation direction of the heating member, wherein the abutting position is the first pressing portion. Since the first contact portion has a first contact position where the second contact portion contacts the inner peripheral surface of the heating member, and the second contact portion has a second contact position where the second contact portion contacts the inner peripheral surface of the heating member. It is possible to provide a heating device that can provide the same effect as that of the case including the first member and the second member and can simplify the mechanism for supporting the pressing member.

According to a seventh aspect of the present invention, in the heating device of the sixth aspect, the distance between the press contact portion and the first contact position is equal to the distance between the press contact portion and the second contact position. Therefore, even if the pressing member lowers the temperature of the heating member at the contact position, the temperature of the portion where the temperature has decreased is sufficiently increased by the time the pressure member reaches the pressure contact portion. Therefore, it is possible to provide a heating device capable of securing a necessary amount of heat.

According to the invention described in claim 8, in the heating device according to claim 6 or 7, since the pressing member has a slit between the first pressing portion and the second pressing portion,
Even when the heat source is a heater such as a halogen lamp inserted into the heating member, it is possible to provide a heating device capable of quickly raising the temperature of the press contact portion.

According to a ninth aspect of the present invention, in the heating device of the sixth or seventh aspect, the pressing member is heat-permeable at least between the first pressing portion and the second pressing portion. Therefore, even when the heat source is a heater such as a halogen lamp inserted into the heating member, it is possible to quickly increase the temperature of the press contact portion and to provide a heating device in which the strength of the pressing member itself is increased. Can be.

According to the tenth aspect, the third aspect is provided.
10. The heating device according to any one of claims 9 to 9, wherein the shape and / or material of the pressing member at the first contact position and the pressing member at the second contact position are changed to the first contact position. Is set to be smaller than the heat absorption by the pressing member at the second contact position, so that the temperature rises more quickly and the temperature distribution in the axial direction, that is, the longitudinal direction of the heating member can be made uniform. Therefore, when a sheet having a width smaller than the length of the heating member is continuously passed through a thin heating member, the heat of the end portion serving as the sheet non-passing area is not taken away and the temperature rises, so that the center of the heating member in the axial direction is increased. It is possible to provide a heating device that can solve the problem that the temperature of the end portion rises as compared with the temperature of the portion.

According to the eleventh aspect, the first aspect is provided.
In the heating device according to any one of to 10,
Since the pressing member has a heat insulating member for suppressing the heat absorption by the pressing member, the pressing member absorbs the heat energy generated by the heat source and the loss of the heat energy is suppressed, and the heat supply efficiency is further increased. A heating device capable of increasing the temperature can be provided.

According to a twelfth aspect of the present invention, there is provided the heating device according to any one of the first to eleventh aspects, wherein the sheet is heated by passing a sheet between the heating member and the pressure roller. Since there is a fixing device that heats and fixes a toner image on a sheet, the effects that can be achieved by the heating device according to any one of claims 1 to 11 can be obtained, and heating during standby can be reduced, or Since it can be eliminated and the power consumption during standby can be greatly reduced, the total power consumption in combination with the operation can be significantly reduced, and a high-quality fixed image can be obtained. An apparatus can be provided.

[Brief description of the drawings]

FIG. 1 is a partially sectional front view of a heating device to which the present invention is applied.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a side sectional view showing an example when there are two pressing members.

FIG. 4 is a side sectional view showing another example in which there are two pressing members.

FIG. 5 is a side sectional view showing an example of a case where the pressing member has a cylindrical shape.

FIG. 6 is a side sectional view showing another example in which the pressing member has a columnar shape.

FIG. 7 is a side sectional view in a case where the pressing member is formed of a kamaboko-shaped member and a cylindrical member.

FIG. 8 is a cross-sectional view illustrating an example where the pressing member has a heat insulating member.

FIG. 9 is a cross-sectional view showing another example when the pressing member has a heat insulating member.

FIG. 10 is a cross-sectional view showing a case where a cylindrical pressing member has a heat insulating member.

FIG. 11 is a perspective view showing a case where the pressing member has first and second pressing portions and a slit.

FIG. 12 is a perspective view showing a case where the pressing member has first and second pressing portions and a heat-permeable member.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Heating member 2 Pressure roller 3 Pressing member 3a 1st pressing member 3b 2nd pressing member 3c 1st pressing part 3d 2nd pressing part 17 Sheet 19 Heat insulation member 21 Slit 22 Heat permeable member a Heating member Rotation direction of A A portion of the inner peripheral surface of the heating member corresponding to the pressure contact portion between the heating member and the pressure roller

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H033 AA06 AA15 AA21 AA30 AA32 BB12 BB28 BB33 BB34 BB38 3J103 AA02 AA14 AA41 AA71 BA03 BA17 BA19 BA34 FA01 FA03 FA20 GA02 GA57 GA58 GA60 GA66 HA03 HA04 HA32 HA37 A43A53A AA45 AA81 BA18 CA23 CE02 CE12 CE13 CE17 CE19 DA02 DA03 GA06

Claims (12)

[Claims] 1. A heating device comprising: a cylindrical heating member; a pressing roller for pressing against the heating member; and a pressing member disposed in contact with the inner peripheral surface of the heating member on the pressing roller side. In a heating device that passes a sheet between a member and the pressure roller to heat the sheet, the pressing member is other than a portion of the inner peripheral surface of the heating member corresponding to a pressure contact portion between the heating member and the pressure roller. A heating device, which is in contact with the position of (1). 2. The heating device according to claim 1, wherein the pressing member is in contact with the inner peripheral surface of the heating member at a plurality of contact positions. 3. The heating device according to claim 2, wherein the pressing member includes a first pressing member that contacts an inner peripheral surface of the heating member at an upstream side of the pressing portion in a rotation direction of the heating member. A second abutment on the inner peripheral surface of the heating member on the downstream side of the pressing portion in the rotation direction of the heating member.
The contact position is a first contact position where the first pressing member contacts the inner peripheral surface of the heating member, and the second pressing member is an inner peripheral surface of the heating member. And a second abutting position that abuts against the heating device. 4. A heating apparatus according to claim 3, wherein a distance between said press contact portion and said first contact position is larger than a distance between said press contact portion and said second contact position. apparatus. 5. The heating device according to claim 3, wherein
A heating device, wherein the first pressing member and / or the second pressing member is a rotating body parallel to the heating member. 6. The heating device according to claim 2, wherein the pressing member has a first pressing portion that contacts an inner peripheral surface of the heating member on an upstream side of the pressing portion in a rotation direction of the heating member. A second pressing portion abutting on the inner peripheral surface of the heating member on the downstream side of the pressing portion in the rotation direction of the heating member, wherein the abutting position is such that the first pressing portion has an inner peripheral surface of the heating member. A heating device comprising: a first contact position in contact with a surface; and a second contact position in which the second pressing portion contacts an inner peripheral surface of the heating member. 7. A heating apparatus according to claim 6, wherein a distance between said press contact portion and said first contact position is larger than a distance between said press contact portion and said second contact position. apparatus. 8. The heating device according to claim 6, wherein
The heating device, wherein the pressing member has a slit between the first pressing portion and the second pressing portion. 9. The heating device according to claim 6, wherein
The heating device according to claim 1, wherein at least a portion between the first pressing portion and the second pressing portion is heat-permeable. 10. The heating device according to claim 3, wherein the pressing member at the first contact position and the pressing member at the second contact position have different shapes and / or materials. Wherein the heat absorption by the pressing member at the first contact position is set smaller than the heat absorption by the pressing member at the second contact position. 11. The heating device according to claim 1, wherein the pressing member has a heat insulating member for suppressing heat absorption by the pressing member. 12. A toner image on a sheet having the heating device according to claim 1, wherein the sheet is heated by passing the sheet between the heating member and the pressure roller. A fixing device for fixing the toner by heating.