JP4706726B2 - Fixing apparatus and image forming apparatus - Google Patents

Description

The present invention relates to a fixing device and an image forming equipment.

As a device that contacts the surface of a medium and transfers heat to the medium, for example, a fixing device that is used in an image forming apparatus such as an electrophotographic copying machine or a printer and fixes a transferred unfixed toner image is known. Yes (Patent Documents 1 to 5 below).

Japanese Patent Laid-Open No. 11-24469 discloses a fixing device having a cylindrical heating roller (2) in which a heater (3) is housed and a pressure roller (102). The thickness value in the radial direction of (2) is made as thin as possible, and the central portion is thicker than both ends, and the heat capacity of the central portion is increased. Techniques for reducing the occurrence are described. In Patent Document 1, the thickness value is 3 mm at the center and 2 mm at both ends, or a protrusion (5a) with a thickness of 4 mm and a recess (5b) with a thickness of 2 mm are formed in the center. Or a technique in which the thickness of both ends is set to 2 mm and the thickness is gradually increased toward the center.

In Patent Document 2 (Japanese Patent Laid-Open No. 2002-196602), in a fixing device having a heat ray fixing roller (17a) and a pressure roller (47a), the heat ray fixing roller (17a) has a thickness of 0.5 mm. An elastic layer (0.5 mm to 5 mm thick) on the surface of the substrate (171a) of ˜5 mm
171d) is formed, a heat ray absorbing layer (171b) of 25 μm to 200 μm is formed on the surface, and a release layer (171a) of 25 μm to 75 μm is formed on the surface thereof. In the technique described in Patent Document 2, the outer surfaces of both ends of the heat ray fixing roller (17a) are directly supported by bearings (B5, B6).

In Patent Document 3 (Japanese Patent Laid-Open No. 2001-215829), in a fixing device having a fixing roller (17a) and a pressure roller (47a), the fixing roller (17a) has a wall thickness of 0.07.
It is composed of a thin plate elastic roller (171a) of mm to 0.7 mm, and a thin plate elastic roller (17
Press member (PVa, PVb, PVc) facing the pressure roller (47a) from the inside of 1a)
Is arranged. In Patent Document 3, the outer surfaces of both ends of the fixing roller (17a) are directly supported by resin bearings (171j).

In Patent Document 4 (Japanese Patent Laid-Open No. 2004-52994), an elastic layer (3) is formed on the surface of a shaft (2) as a heating roller or a pressure roller for a fixing device, and 0.0 0.0 is formed on the surface.
In the metal hollow cylinder pair (4) thinned to 2 mm to 0.15 mm, a plurality of cylindrical cavities (6) are formed in the elastic body layer (3) along the axial direction of the shaft. The technology is described.

In Patent Document 5 (Japanese Patent Application Laid-Open No. 2004-144971), both ends of a metal sleeve (13) having a thickness of 20 μm to 100 μm in a fixing device having a metal sleeve (13) and a pressure roller (20) are disclosed. The protective cap (15) is rotatably supported, and the heat insulating stay holder (12) and the heater (11) are supported inside the metal sleeve (13) so as to face the pressure roller (20). Techniques related to the device are described. Moreover, in the said patent document 5, the length of the axial direction both ends of metal sleeve (13) protrudes from the heating nip part formed in pressure contact with the pressure roller (20), and is formed in the edge part. The heat insulating stay holder (12) and the heater (11) extend further outward than the metal sleeve (13).

In addition to image forming apparatuses such as the electrophotographic copying machines and printers, as an apparatus that contacts the surface of the medium and transfers heat to the medium, ink that is used in an ink jet type image forming apparatus and protrudes ink. A heating device or the like that is provided on the upstream side of the head in the medium conveyance direction and applies heat to the medium is known.

Japanese Patent Laid-Open No. 11-24469 (“0046” to “0049”, “0063”, “0075”, FIG. 1, FIG. 3, FIG. 5) JP 2002-196602 A (“0060” to “0063”, “0065”, FIG. 2, FIG. 4 to FIG. 6) JP 2001-215829 A (“0036”, “0040” to “0041”, FIG. 3, FIG. 4, FIG. 6 to FIG. 8) JP 2004-52994 A (“0016”) JP 2004-144971 A ("0039" to "0075", FIGS. 2 to 4)

  An object of the present invention is to reduce wasteful consumption of electric power.

In order to solve the technical problem, a fixing device according to claim 1 is provided.
A heat fixing member that is rotatably supported and heated;
A pressure fixing member supported in a state of being pressed against the heat fixing member;
A fixing device for fixing an unfixed image on a medium surface between the heat fixing member and the pressure fixing member,
The heat fixing member is
A metal cylindrical and elastically deformable base extending in the medium width direction intersecting the medium conveying direction;
A base body insertion portion having an outer peripheral surface having a circular cross section perpendicular to the axial direction and inserted into the base body from an axial end portion of the cylindrical base body; and an axial outer end of the base body insertion portion. The bearing portion is disposed and supported rotatably by the bearing member, and is supported between the outer peripheral surface of the base body insertion portion and the inner peripheral surface of the base body, and is elastically deformed according to the elastic deformation of the base body. A buffer member that relieves stress concentration on the substrate, the buffer member having an axially inner end disposed on the same side or on the inner side with respect to the axially inner end of the substrate insertion portion , A holding member that holds the axial end in a cylindrical shape;
A heat source member extending in the axial direction of the cylindrical base body and spaced from the inner surface of the base body;
Have
The heat fixing member, when passing through the fixing portion to be rotated to fix the unfixed image of the medium surface is elastically deformed without placing member inscribed in the metal cylindrical inner surface of the fixing unit Then, pressure is applied to the medium, heat is applied by increasing the contact area with the medium, and after being rotated and passed through the fixing unit in contact with the medium, elastic recovery is performed.

In order to solve the technical problem, a fixing device according to claim 2 is provided.
A heat fixing member that is rotatably supported and heated;
A pressure fixing member supported in a state of being pressed against the heat fixing member;
A fixing device for fixing an unfixed image on a medium surface between the heat fixing member and the pressure fixing member,
The heat fixing member is
A metal cylindrical and elastically deformable base extending in the medium width direction intersecting the medium conveying direction;
A base body insertion portion that is inserted into the inside of the base body from an axial end portion of the cylindrical base body and has a circular outer peripheral surface in a cross section orthogonal to the axial direction, and goes in the axial direction inside the base body. The base insertion portion formed so that the outer diameter of the outer surface becomes smaller and the inner end in the axial direction is arranged on the inner side of the outer end in the axial direction of the pressure fixing member, and the shaft of the base insertion portion A bearing member disposed at an outer end in the direction and rotatably supported by a bearing member, and holding the axial end of the base body in a cylindrical shape,
A heat source member extending in the axial direction of the cylindrical base body and spaced from the inner surface of the base body;
Have
The pressure fixing member has an axial outer end disposed between the axial outer end of the base and the axial inner end of the holding member in the axial direction,
The heat fixing member, when passing through the fixing portion to be rotated to fix the unfixed image of the medium surface is elastically deformed without placing member inscribed in the metal cylindrical inner surface of the fixing unit Then, pressure is applied to the medium, heat is applied by increasing the contact area with the medium, and after being rotated and passed through the fixing unit in contact with the medium, elastic recovery is performed.

In order to solve the technical problem, a fixing device according to a third aspect of the present invention includes:
A heat fixing member that is rotatably supported and heated;
A pressure fixing member supported in a state of being pressed against the heat fixing member;
A fixing device for fixing an unfixed image on a medium surface between the heat fixing member and the pressure fixing member,
The heat fixing member is
A metal cylindrical and elastically deformable base extending in the medium width direction intersecting the medium conveying direction;
A base body insertion portion that is inserted into the inside of the base body from the axial end portion of the cylindrical base body and has a circular outer peripheral surface in a cross section perpendicular to the axial direction, and goes inward in the axial direction of the base body. The base insert portion formed so that the thickness in the radial direction becomes thinner and the inner end in the axial direction is disposed inside the outer end in the axial direction of the pressure fixing member; A bearing member disposed at an end and rotatably supported by a bearing member, and holding the axial end of the base body in a cylindrical shape,
A heat source member extending in the axial direction of the cylindrical base body and spaced from the inner surface of the base body;
Have
The pressure fixing member has an axial outer end disposed between the axial outer end of the base and the axial inner end of the holding member in the axial direction,
The heat fixing member, when passing through the fixing portion to be rotated to fix the unfixed image of the medium surface is elastically deformed without placing member inscribed in the metal cylindrical inner surface of the fixing unit Then, pressure is applied to the medium, heat is applied by increasing the contact area with the medium, and after being rotated and passed through the fixing unit in contact with the medium, elastic recovery is performed.

  According to a fourth aspect of the present invention, in the fixing device according to the third aspect,
  The base body insertion portion in which a plurality of grooves extending from an inner end to an outer end portion along the axial direction of the base body are formed;
  It is provided with.

According to a fifth aspect of the present invention, in the fixing device according to any one of the first to fourth aspects,
The substrate is elastically deformed in a flat shape along the medium conveyance direction in the fixing unit.

In order to solve the technical problem, an image forming apparatus according to a sixth aspect of the present invention provides:
An image carrier,
A latent image forming apparatus for forming a latent image on the surface of the image carrier;
A developing device for developing the latent image on the surface of the image carrier into a visible image;
A transfer device for transferring a visible image on the surface of the image carrier to a medium;
A fixing device according to any one of claims 1 to 5 for fixing the visible image of the medium surface,
It is provided with.

According to the invention described in claim 1, as compared to the case not having the constitution of the present invention, it is possible to warm the heat capacity is smaller heat fixing member promptly, heat capacity by members inscribed in the cylindrical inner surface of the fixing unit Increase can also be reduced, and wasteful consumption of heat and power can be reduced. In addition, according to the first aspect of the present invention, the cylindrical shape can be held by the holding members at both ends of the elastically deforming base as compared with the case where the configuration of the present invention is not provided, and the base can be reliably rotated. it can. Furthermore, according to the first aspect of the present invention, the stress concentration of the substrate can be reduced as compared with the case where the buffer member is not provided.

  According to the invention described in claim 2, the heat capacity is small as compared with the case where the configuration of the present invention is not provided.
A member that can quickly heat a heat-fixing member that is inscribed in the cylindrical inner surface of the fixing portion
The increase in heat capacity due to the heat can be reduced, and wasteful consumption of heat and power can be reduced. Further, according to the invention described in claim 2, the cylindrical shape can be held by the holding members at both ends of the elastically deforming base as compared with the case without the configuration of the present invention, and the base can be reliably rotated. it can. Furthermore, according to the second aspect of the present invention, the base body is easily elastically deformed along the base body insertion portion, and the stress concentration of the base body can be reduced as compared with the case where the structure of the present invention is not provided.

  According to the invention described in claim 3, the heat capacity is small as compared with the case where the configuration of the present invention is not provided.
A member that can quickly heat a heat-fixing member that is inscribed in the cylindrical inner surface of the fixing portion
The increase in heat capacity due to the heat can be reduced, and wasteful consumption of heat and power can be reduced. Further, according to the invention described in claim 3, as compared with the case where the configuration of the present invention is not provided, the cylindrical shape can be held by the holding members at both ends of the elastically deformable base, and the base can be reliably rotated. it can. Furthermore, according to the invention described in claim 3, the base body insertion portion whose thickness in the radial direction becomes thinner toward the inner side in the axial direction of the base body is easily deformed little by little toward the inner side in the axial direction. Compared with the case where the configuration of the present invention is not provided, the stress concentration of the substrate can be relaxed.

According to invention of Claim 4, compared with the case where the some groove part is not formed, a base | substrate insertion part can be made to be elastically deformed easily.
According to the fifth aspect of the present invention, the medium conveyance performance can be improved compared to the case where the configuration of the present invention is not provided.
According to the invention described in 請 Motomeko 6, compared to the case not having the constitution of the present invention, it is possible to reduce wasteful consumption of heat and electricity, lower power consumption during use, the power saving An image forming apparatus can be provided.

Next, specific examples of embodiments of the present invention (hereinafter referred to as examples) will be described with reference to the drawings, but the present invention is not limited to the following examples.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The direction indicated by Z and -Z or the indicated side is defined as the front side, the rear side, the right side, the left side, the upper side, the lower side, or the front side, the rear side, the right side, the left side, the upper side, and the lower side, respectively.
In the figure, “•” in “○” means an arrow pointing from the back of the page to the front, and “×” in “○” is the front of the page. It means an arrow pointing from the back to the back.
In the following description using the drawings, illustrations other than members necessary for the description are omitted as appropriate for easy understanding.

1 is a perspective explanatory view of an image forming apparatus according to a first embodiment of the present invention.
FIG. 2 is an overall explanatory view of the image forming apparatus according to the first embodiment of the present invention.
FIG. 3 is an explanatory perspective view of the image forming apparatus according to the first exemplary embodiment of the present invention with the side cover opened.
1 to 3, a printer U as an example of an image forming apparatus according to a first embodiment of the present invention is
A sheet feeding container TR1 that accommodates a sheet S as an example of a medium on which an image is recorded is accommodated in the lower part, and a paper discharge part TRh is provided on the upper surface. In addition, an operation unit UI for performing various operations such as button input is provided on the upper portion of the printer U.

The printer U according to the first exemplary embodiment includes an image forming apparatus main body U1, a front cover U2 as an example of an openable opening / closing unit provided on the front side of the image forming apparatus main body U1, and the image forming apparatus U1.
And a side cover U3 as an example of an openable / closable opening / closing portion provided on the side surface. The front cover U2 is opened when the inside of the image forming apparatus main body U1 is opened in order to remove an image carrier cartridge, a developing device, replacement of a failed member, cleaning maintenance, and a sheet S that is jammed. The cover U3 is opened when the developer supply container, so-called toner cartridge, is replaced.
In FIG. 3, when the side cover U3 of the printer U is moved to the open position, the printer U
The toner cartridges TCy, TCm, and the like as an example of the developer container are opened.
TCc and TCk can be handled.

2, the printer U includes a control unit C that performs various controls of the printer U, an image processing unit IPS that is controlled by the control unit C, an image writing device driving circuit DL, a power supply device E, and the like. ing. The power supply device E includes charging rollers CRy to CRk as an example of a charger described later, a developing roller as an example of a developer holder, and a transfer roller T1y as an example of a transfer device.
A voltage is applied to T1k and the like.
The image processing unit IPS converts print information input from an external image information transmission device or the like into K (
It is converted into latent image forming image information corresponding to four color images of black, Y (yellow), M (magenta), and C (cyan), and output to the image writing device drive circuit DL at a predetermined timing. To do. The image writing device drive circuit DL sends a drive signal to the latent image forming device RO according to the input image information of each color.
Output to S. The latent image forming device ROS emits laser beams Ly, Lm, Lc, and Lk as an example of image writing light for image writing of each color in accordance with a drive signal.

In FIG. 2, Y (yellow), M (in front of the latent image forming device ROS (+ X direction)).
Visible image forming devices UY, UM, UC, and UK that form toner images as examples of visible images of colors of magenta, C (cyan), and K (black) are disposed.
The K (black) visible image forming apparatus UK has a photoconductor Pk as an example of a rotating image carrier. Around the photosensitive member Pk, a charging roll CRk as an example of a charger, a developing device Gk that develops an electrostatic latent image on the surface of the photosensitive member into a visible image, and a developer remaining on the surface of the photosensitive member Pk are removed. A photoconductor cleaner CLk as an example of an image carrier cleaner is disposed.

The surface of the photosensitive member Pk is uniformly charged by the charging roll CRk in the charging area facing the charging roll CRk, and then the latent image is written by the laser beam Lk in the latent image forming area.
The written electrostatic latent image is visualized in the developing area facing the developing device Gk.
The black visible image forming apparatus UK according to the first exemplary embodiment includes an exchangeable image carrier cartridge in which the photoconductor Pk, the charger CRk, and the photoconductor cleaner CLk are integrally formed and exchangeable, and the developing device Gk. And a possible developing cartridge.
The visible image forming apparatuses UY, UM, and UC of other colors are configured by an image carrier cartridge and a developing cartridge that can be attached to and detached from the image forming apparatus main body U1 in the same manner as the black visible image forming apparatus UK. ing. In the first embodiment, the four visible image forming devices UY to UK are supported by a detachable frame Ut, a so-called exchange frame Ut.
Y to UK are configured to be interchangeable with the image forming apparatus main body U1.

In FIG. 2, a belt module BM as an example of a recording medium transport device supported by the opening / closing portion U2 is disposed in front of the photoconductors Py to Pk (+ X direction). The belt module BM includes a medium conveying belt B as an example of a recording medium holding and conveying member, a belt driving roll Rd as an example of a driving member that supports the medium conveying belt B, and a driven roll Rj as an example of a driven member. Belt support roll (Rd +) as an example of a holding and conveying member support system
Rj) and a transfer roll T as an example of a transfer device arranged to face each of the photoconductors Py to Pk
1y, T1m, T1c, T1k, and belt cleaner C as an example of a holding and conveying member cleaner
Lb, and a medium adsorbing roll Rk as an example of a recording medium adsorbing member that is disposed to face the driven roll Rj and adsorbs the sheet S to the medium conveying belt B. However, the medium adsorption roll Rk is not always necessary and can be omitted. The medium transport belt B is rotatably supported by the belt support roll Rd + Rj.

The image density sensor SN1 is for detecting the density of a density detection image, that is, a so-called patch image, formed by an image density adjusting means (not shown) of the control unit C at a predetermined time. The adjusting means adjusts the voltage applied to the chargers CRy to CRk, the developing devices Gy to Gk, and the transfer rolls T1y to T1k based on the image density detected by the image density detecting member, and the latent image writing light Ly to By adjusting the intensity of Lk, image density adjustment and correction, so-called process control is performed.

The sheet S as an example of the recording medium in the paper supply container TR1 disposed below the medium conveyance belt B is taken out by the paper supply member Rp and conveyed to the medium conveyance path SH.
The sheet S in the medium conveyance path SH is conveyed by a medium conveyance roll Ra as an example of a medium conveyance member, and is sent to a registration roll Rr as an example of a sheet feeding timing adjustment member. Regiroll Rr
Transports the sheet S to a recording medium suction position Q6, which is a region where the driven roll Rj and the medium suction roll Rk face each other at a predetermined timing. The sheet S conveyed to the recording medium adsorption position Q6 is electrostatically adsorbed to the medium conveyance belt B.

The sheet S adsorbed to the medium conveying belt B sequentially passes through the transfer areas Q3y, Q3m, Q3c, and Q3k that are in contact with the photoreceptors Py to Pk.
The transfer rolls T1y, T1m, T1c, and T1k disposed on the back side of the medium conveying belt B in the transfer areas Q3y, Q3m, Q3c, and Q3k include a power supply circuit E controlled by the controller C.
A transfer voltage having a polarity opposite to the charging polarity of the toner is applied at a predetermined timing.
In the case of a multicolor image, the toner images on the respective photoreceptors Py to Pk are transferred to the transfer rolls T1y and T1m.
, T1c, and T1k, the image is transferred onto the sheet S on the medium conveying belt B in an overlapping manner. In the case of a monochromatic image, so-called monochrome image, only a K (black) toner image is formed on the photoreceptor Pk, and only the K (black) toner image is transferred to the sheet S by the transfer device T1k.
The photoreceptors Py to Pk after the toner image transfer are cleaned by the toner remaining on the surface being collected by the photoreceptor cleaners CLy to CLk, and charged again by the charging rolls CRy to CRk.

The sheet S on which the toner image is transferred is an example of a heat fixing member of the fixing device F, and is a heating roll Fh as an example of a cylindrical rotating member, and a pressure roll F as an example of a pressure fixing member.
Fixing is performed in a fixing region Q5 formed by pressure contact with p. The sheet S on which the image is fixed is discharged from a discharge roller Rh as an example of a medium discharge member to the medium discharge unit TRh.
The medium conveying belt B after the sheet S is separated is cleaned by the belt cleaner CLb.
The medium according to the first embodiment includes the medium conveyance path SH, the medium conveyance roll Ra, the registration roll Rr, the medium conveyance belt B, the heating roll Fh and the pressure roll Fp as an example of the medium conveyance member of the fixing device F, and the discharge roll Rh. A transport device is configured.

(Fixing device)
FIG. 4 is an enlarged cross-sectional view of the fixing device according to the first exemplary embodiment.
FIG. 5 is an explanatory view of the main part of the cross section taken along the line VV of FIG.
4 and 5, in the fixing device F according to the first embodiment, the heating roll Fh includes a base body 1 formed of a thin metal cylinder extending in the left-right direction. The substrate 1 of Example 1 is made of nickel steel having an outer diameter of 25 mm and a wall thickness of 0.1 mm, and is configured to be elastically deformable and to maintain a cylindrical shape with its own rigidity. Therefore, the substrate 1 is
It is elastically deformed by contact with the pressure roll Fp to increase the area of a contact area that is an example of a contact portion along the medium conveyance direction, that is, a nip area that is an example of a so-called fixing section, and the pressure roll Fp Pressure is applied to a medium in a contact area, which is an example of a contact part, and a nip area, which is an example of a so-called fixing part, and is not in contact with the pressure roll Fp. It is configured so as to be restored to a cylindrical shape by elastically restoring with the rigidity.

That is, the base 1 of the heating roll Fh of the first embodiment is different from a configuration in which a cylindrical shape cannot be maintained with its own rigidity like an endless member so-called belt member, and the base 1 is flat in the fixing region Q5. There is no pressing member, so-called support member, for deforming into a predetermined shape or applying a predetermined contact pressure.
In addition, although the said thickness illustrated 0.1 mm, it is not limited to this, The thickness of 0.15 mm or less thinner than 0.16 mm which is the minimum of the thickness of the heating roll currently generally used, and Preferably in the range of 0.07 mm to 0.12 mm. Nickel steel with a wall thickness of 0.1 mm can be produced by any method. For example,
It can be configured by electroforming, deep drawing, or the like.

Moreover, although nickel steel was illustrated as a material, it is not limited to this material, For example, stainless steel, what is called SUS: Stainless Used Steel, nickel-cobalt alloy, copper, gold | metal | money, nickel-iron alloy etc. can be used. In Example 1, the substrate 1 alone is used, but a surface layer of about several μm to several tens of μm, that is, a so-called coat layer can be formed on the surface in order to improve the releasability. As the coat layer, it is preferable to use a fluororesin having good releasability. In the first embodiment, the contact area is a portion that comes into contact with the medium, which is a Q5 area in FIG. 4 and an R2 area in FIG.

4 and 5, a pair of left and right substantially cylindrical holding members 2 and 3 are provided at both ends of the base 1.
Is supported. The holding members 2 and 3 are arranged on the inner end side and are integrally formed on cylindrical base body insertion portions 2a and 3a to be inserted into the base body 1 and on the outer end side of the base body insertion portions 2a and 3a. Further, it has cylindrical bearing parts 2b and 3b having a diameter larger than that of the base body 1 and thicker than that of the base body insertion parts 2a and 3a. In addition, heater passing holes 2c and 3c penetrating in the axial direction are formed in the central portions of the holding members 2 and 3, respectively. Each of the left and right holding members 2 and 3 is rotatably supported at its outer periphery by a bearing member Fha, and a driven force from a driving source (not shown) is transmitted to the outer end portion of the left holding member 3. The gear 4 is fixedly supported.

The heating roll Fh includes therein a small-size sheet heater h1 and a large-size sheet heater h2 as an example of a heat source member that extends in the axial direction through the base 1 and the heater passage holes 2c and 3c. Yes. In FIG. 5, the heater h1 for small size sheets is
The sheet width in the direction perpendicular to the sheet conveying direction is configured to heat substantially the same width as the small size sheet fixing region R1, which is a region through which a small size sheet of A4SEF or less passes, and LetterS
E: When fixing a sheet having a width equal to or less than the width of the letter size sheet short edge, only the small size sheet heater h1 is controlled to be turned on / off.

The large-size sheet heater h2 has a sheet width in the direction perpendicular to the sheet conveying direction of A4S.
Although it has substantially the same width as the large-size sheet fixing region R2, which is a region through which a large-sized sheet longer than EF passes, the small-size sheet fixing region R1 at the center thereof does not generate heat,
Only both ends generate heat. LetterSE: When fixing a sheet having a width larger than the width of the letter size sheet short edge, both the large size sheet heater h2 and the small size sheet heater h1 are independently controlled to be turned on / off.
In FIG. 3, for example, “LEF” in A4LEF is an abbreviation for long edge feed, meaning a sheet conveyed with the long side of the paper at the front end, and “S” in A3SEF.
“EF” is an abbreviation for short edge feed, and means a sheet conveyed with the short side of the paper at the front edge. Therefore, in the first exemplary embodiment, in the fixing device F, the medium passing area which is the length in the sheet width direction of the fixing area Q5 is set as the large size sheet fixing area R2.

4 and 5, in the fixing device F according to the first embodiment, the pressure roll Fp includes a shaft 11 as an example of a rotating shaft and an elastic body layer 12 formed on the outer periphery of the shaft 11.
The shaft 11 of Example 1 is made of a metal material such as SUS having a diameter of 10 mm, and the thickness of the elastic body layer 12 is set so that the outer diameter of the pressure roll Fp is 25 mm.
Both ends of the shaft 11 are rotatably supported by a bearing member Fpa, and the bearing member Fpa is urged toward the heating roll Fh by a coil spring 14 as an example of an urging member. The coil spring 14 is set so that the total load of the pressure roll Fp on the heating roll side is within a range of about 200 [N] to about 300 [N].
The pressure, which is a force per unit area, is set to be about 4 kgf / cm 2.
The elastic layer 12 can be made of any elastic material such as rubber, and can have a single layer structure or a multi-layer structure in which a plurality of elastic layers or surface layers are laminated. It is preferable to use fluorine rubber or the like having a good mold release.

Therefore, in the fixing device F according to the first embodiment, the heating roll Fh includes the heaters h1 and h2 in the so-called sleeve heating roll main body 1 + 2 + 3 in which the holding portions 2 and 3 are attached to both ends of the cylindrical base body 1, respectively. The heaters h <b> 1 and h <b> 2 are arranged in a state of being separated from the inner surface of the substrate 1. The heating roll Fh includes heaters h1,
Heat is generated while h2 is fixed without rotating, and the holding members 2 and 3 and the base 1 are rotated. Therefore, in the heating roll Fh of Example 1, in the fixing region Q5, the support member as in the related art that contacts the inner surface of the substrate 1 from the inside is not disposed, but is disposed separately from the inner surface of the substrate 1. Heat is directly supplied from the heaters h1 and h2 to the base 1 in the fixing region Q5. The pressure roll Fp is a heating roll Fh rotated by the driven gear 4.
The rotation follows the rotation of, i.e., rotates.

FIG. 6 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the first exemplary embodiment.
5 and 6, in the fixing device F of the first embodiment, the axis of the region R3 where the elastic body layer 12 of the pressure roll Fp contacts the base body 1 along the medium width direction of the fixing region Q5, that is, the axial direction. The direction end is set to overlap the region R4 in which the base body insertion portions 2a and 3a are inserted. Further, the axial end of the medium passage region R2 through which the sheet S passes is the inner side in the base axis direction of the region R4 in which the base insertion portions 2a and 3a are inserted, that is, the region R4 and the region R2 do not overlap each other. Is set.

(Operation of Example 1)
In the printer U as an example of the image forming apparatus of Example 1 having the above-described configuration, the pressure roll Fp is pressed against the thin metal cylindrical base 1, and the base in the fixing region Q5 as shown in FIG. 1 and the elastic layer 12 are elastically deformed with each other. At this time, it is elastically deformed in a substantially flat shape with respect to the sheet conveyance direction, the fixing region Q5 is widened, and the conveyance performance of the sheet S is improved.
Stable fixing is performed. As a result, for example, when an envelope as an example of a medium is used, the occurrence of paper folds in the envelope is reduced, and when thick paper is used as an example of a medium, the curvature of the thick paper is reduced.

Then, when the base body 1 rotates and the portion that has been elastically deformed in the fixing region Q5 is separated from the fixing region Q5, the elastically deformed portion is elastically restored to a cylindrical shape. Therefore, in Example 1, when the base body 1 is rotated and passes through the fixing region Q5 in contact with the sheet S, the base body 1 is elastically deformed without disposing a member inscribed in the metal cylindrical inner surface in the fixing region Q5. Then, the pressure is applied to the sheet S, the contact area with the sheet S is increased, heat is applied, and after rotating and passing through the fixing region Q5, the sheet S is elastically restored.
Further, in the fixing device F of Example 1, there is no need for a member that presses the substrate 1 from the inside and deforms it into a predetermined shape corresponding to the fixing region Q5, and the number of members increases or increases as in the prior art. The increase in heat capacity due to the components and the increase in power consumption for heating the increased heat capacity are reduced. That is, the heaters h1 and h2 are efficiently heated as compared with the case where other members having heat capacity are arranged and heated through them.

Therefore, in the fixing device F, the heaters h1 and h2 are efficiently heated to reduce wasteful heat and electric power consumption, and the fixing region Q5 is heated efficiently and quickly, and rises until the start of fixing. The time required for temperature is reduced. Furthermore, in the fixing device F of Example 1, the substrate 1 is
A layer such as an elastic layer is not formed as in the prior art, and the increase in heat capacity due to these layers is reduced. Therefore, in the image forming apparatus U according to the first embodiment, wasteful consumption of heat and power is reduced, power consumption and cost during use, so-called running cost is reduced, and power is saved.

In FIG. 6, in the heating roll Fh, the holding members 2 and 3 hold a cylindrical shape so that the driving force is transmitted by the driven gear 4 and can be rotated, so that the base member 1 is hardly deformed. The cylindrical shape is distorted by elastic deformation at Q5. If the pressure roll Fp contacts only the base 1 and the pressure roll Fp does not contact in the region R4, the holding member 2
, 3 at the holding member inner end position R4a corresponding to the inner end portion, stress concentration is likely to occur. In particular, in a base body on which no elastic body layer is provided, when the thickness is reduced, repeated elastic deformation, Due to elastic recovery, there is a risk of fatigue and damage. On the other hand, in Example 1, the region R4
The pressure roll Fp is in contact with the base 1 at a position corresponding to the holding members 2 and 3 holding the cylindrical shape, and stress concentration at the holding member inner end position R4a is alleviated. That is, in the heating roll Fh of the first embodiment, fatigue due to stress concentration and repeated elastic deformation / restoration at the holding member inner end position R4a, and damage such as bending, bending, and breakage due to repeated fatigue are reduced, and the life is extended. Has been.

Next, a second embodiment of the present invention will be described. In the description of the second embodiment, the first embodiment will be described.
Constituent elements corresponding to those constituent elements are denoted by the same reference numerals, and detailed description thereof is omitted.
The second embodiment is different from the first embodiment in the following points, but in other points, the first embodiment.
It is configured in the same way.

FIG. 7 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the second embodiment, and corresponds to FIG. 6 according to the first embodiment.
In FIG. 7, in the fixing device F according to the second embodiment, the bearing portions 2 b ′ of the holding members 2 ′ and 3 ′,
3 b ′ is formed so as to have a diameter larger than the inner diameter of the substrate 1 and the same diameter as the outer diameter of the substrate 1. The elastic layer 12 ′ of the pressure roll Fp is formed such that the length of both end portions in the axial direction is longer than that of the elastic layer 12 of Example 1, and the outer surface of the elastic layer 12 is the bearing portion. 2b ', 3
It is supported in contact with the outer surface of b '.
Therefore, the pressure roll F along the medium width direction of the fixing region Q5, that is, the axial direction.
The region R3 ′ where p contacts the substrate 1 overlaps the region R4 where the substrate insertion portions 2a and 3a are inserted, and the outer surface of the pressure roll Fp is disposed in contact with the bearing portions 2b ′ and 3b ′. Has been.

(Operation of Example 2)
In the fixing device F of the second embodiment having the above-described configuration, the stress concentration is eased similarly to the first embodiment, and the pressure roll Fp is not only the base 1 but also the holding member 2 ′ to which the driving force is transmitted. Compared with the case where only the substrate 1 is in contact with the substrate 3 and remains thin and easily deformed, and there is a possibility that the driving force is not sufficiently transmitted, an efficient and sufficient driving force is applied from the heating roll Fh. The sheet S is conveyed to the pressure roll Fp and reliably conveyed.

Next, the third embodiment of the present invention will be described. In the description of the third embodiment, the first embodiment will be described.
Constituent elements corresponding to those constituent elements are denoted by the same reference numerals, and detailed description thereof is omitted.
The third embodiment is different from the first embodiment in the following points, but the first embodiment is different in other points.
It is configured in the same way.

FIG. 8 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the third embodiment, and corresponds to FIG. 6 according to the first embodiment.
In FIG. 8, in the fixing device F according to the third embodiment, the base insertion portions 22a of the holding members 22 and 23,
23a has a smaller diameter than the base insertion portions 2a and 3a of the first embodiment. A cylindrical ring-like elastically deformable buffer rubber 24 is supported as an example of a buffer member between the outer peripheral surfaces of the base body insertion portions 22 a and 23 a and the inner peripheral surface of the base body 1. Therefore, Example 3
In the fixing device F, the holding members 22 and 23 include base body insertion portions 22a and 23a, and a bearing portion 22.
b, 23b and the buffer rubber 24. For the buffer rubber 24, any rubber such as silicone rubber can be used, and heat resistant rubber material is preferable because it receives heat from the heaters h1 and h2.

(Operation of Example 3)
In the fixing device F according to the third embodiment having the above-described configuration, the buffer rubber 24 is elastically deformed according to the force received at both ends of the base body 1 that is elastically deformed by contact with the pressure roll Fp, and absorbs the received force. And
It functions as a so-called cushion. Thereby, the stress concentration in the substrate 1 is relaxed.

Next, the fourth embodiment of the present invention will be described. In the description of the fourth embodiment, the first embodiment will be described.
Constituent elements corresponding to the constituent elements 3 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.
The fourth embodiment is different from the first to third embodiments in the following points, but is configured in the same manner as the first to third embodiments in other points.
FIG. 9 is an enlarged explanatory view of the main part of the axial end of the fixing device according to the fourth embodiment, and corresponds to FIG. 6 according to the first embodiment.
In FIG. 9, in the fixing device F of the fourth embodiment, the holding members 22 and 23 of the fourth embodiment have the same cushion rubber 24 as that of the third embodiment, and the bearing portion 22 b ′ having the same shape as that of the second embodiment. ,
23b '.

(Operation of Example 4)
In the fixing device F according to the fourth embodiment having the above-described configuration, as in the third embodiment, the stress concentration is alleviated by the buffer rubber 24 so that the base 1 and the fixing device F have a long service life. Similarly to the above, the driving force is reliably transmitted.

Next, the fifth embodiment of the present invention will be described. In the description of the fifth embodiment, the first embodiment will be described.
Constituent elements corresponding to those constituent elements are denoted by the same reference numerals, and detailed description thereof is omitted.
The fifth embodiment is different from the first embodiment in the following points, but in other points, the first embodiment.
It is configured in the same way.

FIG. 10 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the fifth embodiment, and corresponds to FIG.
In FIG. 10, in the fixing device F of Example 5, in the pressure roll Fp of Example 1, a heating roll is formed on the surface of the pressure roll Fp corresponding to the region R4 in which the base insertion portions 2a and 3a are inserted. A high friction part Fp1 having a higher friction coefficient than the outer surface of the medium passing region R2 of Fp is formed. That is, the region R3 where the pressure roll Fp contacts the substrate 1 and the substrate insertion portion 2a.
, 3a, the high friction part Fp1 is arranged on the outer surface of the pressure roll Fp so as to correspond to the region where the region R4 is inserted. The high friction part Fp1 is, for example, a heating roll Fp.
Increase the friction by roughening the surface of the surface to form a rough surface, or form a good release layer only in the medium passage area and increase the friction by not forming the surface layer at both ends. By doing so, it can be formed.

(Operation of Example 5)
In the fixing device F according to the fifth embodiment having the above-described configuration, the stress concentration is reduced as in the first embodiment, and the friction is increased between the base body 1 and the high friction portion Fp1, so that they are difficult to slip. The drive from the heating roll Fp is reliably transmitted to the pressure roll Fp.

Next, the sixth embodiment of the present invention will be described. In the description of the sixth embodiment, the first embodiment will be described.
Constituent elements corresponding to the constituent elements 5 to 5 are denoted by the same reference numerals, and detailed description thereof is omitted.
Example 6 is different from Examples 1 to 5 in the following points, but is configured in the same manner as Examples 1 to 5 in other points.
FIG. 11 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the sixth embodiment, and corresponds to FIG. 6 according to the first embodiment.
In FIG. 11, in the fixing device F of the sixth embodiment, high friction portions Fp1 are formed at both ends of the pressure roll Fp as in the fifth embodiment, and holding members 22 ′ and 23 for the heating roll Fh.
'Is configured in the same manner as in the fourth embodiment.

(Operation of Example 6)
In the fixing device F of Example 6 having the above-described configuration, the stress concentration is alleviated due to the contact area between the buffer rubber 24 and the pressure roll Fp and the base 1, and the base 1 and the bearing 22b.
The drive from the heating roll Fp is reliably transmitted to the pressure roll Fp by the high frictional contact between ', 23b' and the high friction part Fp1.

Next, the seventh embodiment of the present invention will be described. In the description of the seventh embodiment, the first embodiment will be described.
Constituent elements corresponding to constituent elements 6 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted.
Example 7 is different from Examples 1 to 6 in the following points, but is configured in the same manner as Examples 1 to 6 in other points.

FIG. 12 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the seventh embodiment. FIG. 12A is a diagram corresponding to FIG. FIG.
In FIG. 12, in the fixing device F of the seventh embodiment, the holding members 32 and 33 are the base body insertion portion 32.
a and 33a are formed so that the outer diameters of the outer surfaces of the base body insertion portions 32a and 33a become smaller toward the inner side in the axial direction of the base body 1. In Example 7, the base body insertion portions 32a, 33
The outer surface of a is formed in an outer surface shape that is convexly curved outward in the radial direction in the cross section shown in FIG.

(Operation of Example 7)
In the fixing device F of Example 7 having the above-described configuration, the pressure roll Fp is provided at the end of the base 1.
Is pressed and the base body 1 is elastically deformed, the inner surface of the base body 1 has a base insertion portion 32a,
It is deformed in such a manner that it is guided along the outer surface of 33a. That is, the stress concentration is alleviated as compared with the case where the outer diameter is the same and the stress concentration is generated by being bent at the inner end position of the holding member at the end of the base insertion portion.

Next, an eighth embodiment of the present invention will be described. In the description of the eighth embodiment, the first embodiment will be described.
Constituent elements corresponding to the constituent elements ˜7 are denoted by the same reference numerals, and detailed description thereof is omitted.
Example 8 is different from Examples 1 to 7 in the following points, but is configured in the same manner as Examples 1 to 7 in other points.
FIG. 13 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the eighth embodiment, and corresponds to FIG. 6 according to the first embodiment.
In FIG. 13, in the fixing device F of the eighth embodiment, the base insertion portions 32 a ′ and 33 a ′ having cylindrical outer diameters of the holding members 32 ′ and 33 ′ move inward in the axial direction of the base 1.
The inner surfaces of a ′ and 33a ′ have a large diameter, and the base insert portions 32a ′ and 33a ′ are formed so that the radial thickness, that is, the wall thickness is reduced.

(Operation of Example 8)
In the fixing device F of Example 8 having the above-described configuration, the base body insertion portions 32a ′ and 33a ′ are configured so that the base body 1 is elastically deformed when the pressure roll Fp is pressed against the end of the base body 1.
The base body insertion portions 32a 'and 33a' that come into contact with the inner surface are thinner toward the inner side in the axial direction, and the radial rigidity and elastic coefficient of the base body insertion portions 32a 'and 33a' and the base body 1 are axially outer. It gets bigger little by little as you go to. Therefore, as compared with the case where the base insertion portion is not thinned toward the inner side and the elastic coefficient changes discontinuously at the inner end position of the holding member, the base body 1 is easily deformed little by little from the inner side to the outer side in the axial direction. Stress concentration is relaxed.

Next, the ninth embodiment of the present invention will be described. In the description of the ninth embodiment, the eighth embodiment will be described.
Constituent elements corresponding to those constituent elements are denoted by the same reference numerals, and detailed description thereof is omitted.
The ninth embodiment differs from the eighth embodiment in the following points, but in the other points, the ninth embodiment.
It is configured in the same way.

FIG. 14 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the ninth embodiment. FIG. 14A is a sectional view of the holding member, and FIG. 14B is a side view of the holding member.
In FIG. 14, in the fixing device F of Example 9, the base body insertion portion 3 of the holding members 32 ″, 33 ″.
Similar to the eighth embodiment, 2a ″ and 33a ″ are formed such that the diameter of the inner surface becomes larger and the thickness becomes thinner toward the inner side in the axial direction of the substrate 1. And the holding member 32 of Example 9
In ", 33", the base body insertion portions 32a ", 33a" are formed with a plurality of groove portions extending from the inner end to the outer end portion along the axial direction, so-called slits 32d, 33d.
The outer surfaces of a ″ and 33a ″ are formed in a comb-teeth shape as a whole.

(Operation of Example 9)
In the fixing device F of Example 9 having the above-described configuration, comb-like base body insertion portions 32a ″ and 33a
″ Has a shape in which each of the comb teeth is independent, and can be elastically deformed individually. That is, in the case of being configured in a cylindrical shape as in Example 8, the substrate Insertion part 32a ',
Although the cylindrical base body insertion portions 32a ′ and 33a ′ are deformed so as to be distorted when the base plate 33a ′ is deformed, the base body insertion portions 32a ″ and 33a ″ are not easily deformed. The deformation is configured relatively easily along the deformation, and the stress concentration and the breakage such as bending and bending are reduced.

Next, a description will be given of a tenth embodiment of the present invention. In the description of the tenth embodiment, the same reference numerals are given to the components corresponding to the components of the first to ninth embodiments, and the detailed description thereof will be made. Description is omitted.
Example 10 is different from Examples 1 to 9 in the following points, but is configured in the same manner as Examples 1 to 9 in other points.

FIG. 15 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the tenth embodiment.
It is a figure corresponding to.
In FIG. 15, in the fixing device F of Example 10, the base body insertion portion 42 of the holding members 42 and 43.
a and 43a are comprised so that the outer diameter of an outer surface may become a small diameter as it goes to an axial direction inner side. And according to the shape of the outer diameter of the base body insertion portions 42a, 43a, the base body insertion portions 42a,
As an example of a buffer member, a buffer rubber 44 having an inner diameter that increases toward the inner side in the axial direction is mounted between 43a and the inner surface of the base 1.

(Operation of Example 10)
In the fixing device F of Example 10 having the above-described configuration, the buffer rubber 44 becomes thicker toward the inner side in the axial direction of the base body insertion portions 42a and 43a, and the inner side is more easily elastically deformed. Compared with the case of Example 3, stress concentration, bending, and the like are alleviated more efficiently.

Next, an eleventh embodiment of the present invention will be described. In the description of the eleventh embodiment, constituent elements corresponding to the constituent elements of the first to tenth embodiments are denoted by the same reference numerals, and detailed description thereof will be made. Description is omitted.
Example 11 is different from Examples 1 to 10 in the following points, but is configured in the same manner as Examples 1 to 10 in other points.
FIG. 16 is an enlarged explanatory view of the main part of the end portion in the axial direction of the fixing device according to the eleventh embodiment.
It is a figure corresponding to.
In FIG. 16, in the fixing device F of Example 11, the heating roll Fh is configured similarly to the heating roll of Example 10, and the pressure roll Fp is configured similarly to Example 5.

(Operation of Example 11)
In the fixing device F of the eleventh embodiment having the above-described configuration, it is configured such that it is more easily elastically deformed toward the inner side in the axial direction of the base body insertion portions 42a and 43a, and stress concentration, bending and the like are efficiently relieved and high friction is achieved. The driving force is efficiently transmitted by the portion Fp1.

Next, a description will be given of a twelfth embodiment of the present invention. In the description of the twelfth embodiment, components corresponding to those of the first to eleventh embodiments are denoted by the same reference numerals, and detailed descriptions thereof are given. Description is omitted.
Example 12 is different from Examples 1 to 11 in the following points, but is configured in the same manner as Examples 1 to 11 in other points.

FIG. 17 is an enlarged explanatory view of a main part of an end portion in the axial direction of the fixing device according to the twelfth embodiment.
It is a figure corresponding to.
In FIG. 17, in the fixing device F of Example 12, the heating roll Fh and the pressure roll Fp
Is configured in the same manner as in the fifth embodiment, and the driven gear 4 'is supported on the left end of the shaft 11 of the pressure roll Fp, not the holding member 3 of the heating roll Fh. The driven gear 4 'meshes with a driving gear 4b supported by a driving shaft 4a to which driving is transmitted from a driving source (not shown), and driving is transmitted.

(Operation of Example 12)
In the fixing device F according to the twelfth embodiment having the above-described configuration, the stress concentration of the heating roll Fh is alleviated and the pressure roll Fp is driven to rotate, and the rotation of the pressure roll Fp is heated by the high friction portion Fp1. Therefore, the heating roll Fh can be driven and rotated.

Next, a thirteenth embodiment of the present invention will be described. In the description of the thirteenth embodiment, constituent elements corresponding to the constituent elements of the first to eleventh embodiments are denoted by the same reference numerals, and detailed description thereof will be made. Description is omitted.
Example 13 is different from Examples 1 to 11 in the following points, but is configured in the same manner as Examples 1 to 11 in other points.

18 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the thirteenth embodiment, FIG. 18A is a view corresponding to FIG. 6 of the first embodiment, and FIG. 18B is a perspective explanatory view of a buffer member.
In FIG. 18, in the fixing device F according to the thirteenth embodiment, the holding members 52 and 53 are an example of a buffer member instead of the buffer rubber 24 in the third embodiment, and are cylindrical as an example of an annular member. This corresponds to a configuration in which the metal ring 54 is used. The metal ring 54 of the thirteenth embodiment is constituted by a so-called metal spring that is elastically deformable. Also, metal ring 54
The axial length is longer than that of the base body insertion portions 52 a and 53 a, and the medium passage region R 2 is set inside the axial inner end of the metal ring 54.

(Operation of Example 13)
In the fixing device F of the thirteenth embodiment having the above-described configuration, the metal ring 54 as an example of the buffer member is also elastically deformed when the base body 1 is elastically deformed, and the stress concentration of the base body 1 of the heating roll Fh is alleviated. In addition, the metal ring 54 of Example 13 is made of metal, and is superior in heat resistance as compared to the case of using a cushioning member made of a rubber material that deteriorates when the temperature rises and loses its properties as an elastic member. .

Next, a description will be given of a fourteenth embodiment of the present invention. In the description of the fourteenth embodiment, components corresponding to the components of the first to thirteenth embodiments are denoted by the same reference numerals, and detailed descriptions thereof are given. Description is omitted.
Example 14 is different from Examples 1 to 13 in the following points, but is configured in the same manner as Examples 1 to 13 in other points.

19 is an enlarged explanatory view of a main part of an axial end portion of the fixing device of Example 14, FIG. 19A is a diagram corresponding to FIG. 6 of Example 1, and FIG.
In FIG. 19, in the fixing device F according to the fourteenth embodiment, the holding members 52 ′ and 53 ′ are the same as those in the first embodiment.
3, a metal ring 54 ′ having a shape different from that of the metal ring of the thirteenth embodiment is used as an example of the buffer member instead of the metal ring 54. Similarly to the metal ring 54 of the thirteenth embodiment, the metal ring 54 'of the fourteenth embodiment is configured by a so-called metal spring that can be elastically deformed, and the axial length is longer than that of the base body insertion portions 52a and 53a. The medium passage region R <b> 2 is formed inside the inner end in the axial direction of the metal ring 54. Further, in the metal ring 54 'of the fourteenth embodiment, the axial length is inward from the cylindrical portion 54a' formed corresponding to the base body insertion portions 52a and 53a, and the inner end in the axial direction of the cylindrical portion 54a '. Accordingly, the inner peripheral surface has an inverted conical portion 54b 'formed along the outer peripheral surface of the cone.

(Operation of Example 14)
In the fixing device F of Example 14 having the above-described configuration, the metal ring 54 is elastically deformed when the base 1 is elastically deformed.
'Also elastically deforms. At this time, the elastic coefficient does not change discontinuously at the inner end of the metal ring 54 '.
The metal ring 5 is set so as to gradually increase as it goes outward in the axial direction.
No bending or the like occurs at the inner end of the 4 ′ axial direction, and the stress concentration of the base 1 of the heating roll Fh is further reduced as compared with the case of the thirteenth embodiment.

Next, a description will be given of a fifteenth embodiment of the present invention. In the description of the fifteenth embodiment, components corresponding to the components of the first to fourteenth embodiments are denoted by the same reference numerals, and detailed descriptions thereof are given. Description is omitted.
Example 15 is different from Examples 1 to 14 in the following points, but is configured in the same manner as Examples 1 to 14 in other points.

FIG. 20 is an enlarged explanatory view of the main part of the end portion in the axial direction of the fixing device according to the fifteenth embodiment.
It is a figure corresponding to.
In FIG. 20, in the fixing device F according to the fifteenth embodiment, the holding members 52 ″ and 53 ″ are formed according to the first embodiment.
3 are formed to have the same outer diameter as the base insertion portions 52a and 53a, and two concentric metal rings 56 and 57 are mounted as an example of a buffer member in place of the metal ring 54. The thickness of the metal rings 56 and 57 of the fifteenth embodiment is half that of the metal ring 54 of the thirteenth embodiment. The metal rings 56 and 57 are both constituted by ring-shaped metal springs that can be elastically deformed. The axial length of the inner metal ring 56 is longer than that of the base body insertion portions 52a and 53a. The axial length is longer than the inner metal ring 57. In Example 15, the medium passage region R2 is set inside the inner end in the axial direction of the outer metal ring 57.

(Operation of Example 15)
In the fixing device F of Example 15 having the above-described configuration, the double metal rings 56 and 57 are also elastically deformed when the base body 1 is elastically deformed, and the stress concentration of the base body 1 of the heating roll Fh is alleviated. At this time, the thin metal spring is doubled, and the discontinuity of the elastic modulus along the axial direction is relaxed as in the case of Example 14, and the stress is further increased compared to the case of Example 13. Concentration is eased.

Next, a description will be given of a sixteenth embodiment of the present invention. In the description of the sixteenth embodiment, components corresponding to those of the first to fifteenth embodiments are denoted by the same reference numerals, and detailed descriptions thereof will be given. Description is omitted.
Example 16 is different from Examples 1 to 15 in the following points, but is configured in the same manner as Examples 1 to 15 in other points.

FIG. 21 is an explanatory view of a buffer member of Example 16, FIG. 21A is an explanatory view of a state in which two metal rings are detached, FIG. 21B is a sectional view along the axial direction in FIG. 21A, and FIG. It is sectional drawing of the state in which the ring was piled up.
21, in the fixing device F according to the sixteenth embodiment, the metal ring 56 in which a plurality of groove portions, so-called slits 56 a ′ and 57 a ′, are formed instead of the metal rings 56 and 57 according to the fifteenth embodiment.
', 57' are used. In the sixteenth embodiment, the slits 56a 'and 57a' are formed on the inner end side in the axial direction of the base 1, and the slit 57a 'of the outer metal ring 57' corresponds to the inner end of the inner metal ring 56 '. It is composed of a slit of depth.

(Operation of Example 16)
In the fixing device F according to the sixteenth embodiment having the above-described configuration, when the double metal rings 56 ′ and 57 ′ are also elastically deformed when the base body 1 is elastically deformed, the cylinder is distorted in the cylindrical shape as in the fifteenth embodiment. In the sixteenth embodiment, the slit portions 56a ′ and 57a ′ are difficult to deform because of deformation.
Is easily deformed, and the stress concentration is efficiently relieved. Further, slits 56a 'and 57a' are formed on the inner end side in the axial direction, and the inner end side is configured to be elastically deformable so as to flexibly correspond to the elastic deformation of the base 1.

Next, Embodiment 17 of the present invention will be described. In the description of Embodiment 17, the same reference numerals are given to the components corresponding to the components of Embodiments 1 to 16, and the detailed description thereof will be made. Description is omitted.
Example 17 is different from Examples 1 to 16 in the following points, but is configured in the same manner as Examples 1 to 16 in other points.

FIG. 22 is an explanatory diagram of the buffer member according to the seventeenth embodiment and corresponds to FIG. 6 according to the first embodiment.
In FIG. 22, in the fixing device F according to the seventeenth embodiment, the heating roll Fh includes the holding members 22 and 23 having the buffer rubber 24, similarly to the heating roll Fh according to the third embodiment.
On the other hand, in Example 17, the outer end of the pressure roll Fp is the base insertion portion 22 of the holding members 22 and 23.
Unlike the first to sixteenth embodiments, the region R3 in which the pressure roll Fp is in contact with the heating roll Fh is set on the inner side in the axial direction. The medium passing area R2 where the unfixed toner image is fixed is set corresponding to the contact area R3 of the pressure roll Fp.
Therefore, in Example 17, along the medium width direction of the fixing region Q5, the region R3 where the pressure roll Fp contacts the substrate 1 is the inner side in the substrate axis direction of the region R4 where the substrate insertion portions 22a and 23a are inserted. In addition, the medium passage region R2 through which the sheet S passes is set on the inner side in the base axis direction of the region R4 in which the base insertion portions 22a and 23a are inserted.

(Operation of Example 17)
In the fixing device F of Example 17 having the above-described configuration, the buffer rubber 24 is elastically deformed according to the force received at both ends of the base body 1 that is elastically deformed by contact with the pressure roll Fp, and absorbs the received force. And it functions as a so-called cushion. Thereby, the stress concentration in the substrate 1 is relaxed. In Example 17, the stress concentration can be relaxed compared to the case where the elastic rubber cushioning rubber 24 is not provided. That is, in the heating roll Fh of Example 17, fatigue due to stress concentration and repeated elastic deformation / restoration at the holding member inner end position R4a, and damage such as bending, bending, and breakage due to repeated fatigue are reduced, and the life is extended. Has been.

Next, Embodiment 18 of the present invention will be described. In the description of Embodiment 18, the same reference numerals are given to the components corresponding to the components of Embodiments 1 to 17, and the detailed description thereof will be made. Description is omitted.
Example 18 is different from Examples 1 to 17 in the following points, but is configured in the same manner as Examples 1 to 17 in other points.

FIG. 23 is an explanatory diagram of the buffer member of the eighteenth embodiment and corresponds to FIG. 6 of the first embodiment.
In FIG. 23, in the fixing device F of Example 18, the heating roll Fh is configured to have the holding members 42 and 43 having the buffer rubber 44 in the same manner as the heating roll Fh of Example 10. On the other hand, in Example 18, the position of the outer end of the pressure roll Fp is set inward in the axial direction from the base body insertion portions 42a and 43a, as in Example 17.

(Operation of Example 18)
In the fixing device F of Example 18 having the above-described configuration, the buffer rubber 44 is elastically deformed according to the force received at both ends of the base body 1 that is elastically deformed by contact with the pressure roll Fp, and absorbs the received force. In addition, the stress concentration in the base body 1 is relieved, and the thickness of the buffer rubber 44 is increased toward the inner side in the axial direction, so that stress concentration and bending are efficiently relieved on the inner side.

Next, the nineteenth embodiment of the present invention will be described. In the description of the nineteenth embodiment, the same reference numerals are given to the components corresponding to the components of the first to eighteenth embodiments, and the detailed description thereof will be made. Description is omitted.
Example 19 is different from Examples 1 to 18 in the following points, but is configured in the same manner as Examples 1 to 18 in other points.

FIG. 24 is an explanatory diagram of the buffer member of the nineteenth embodiment and corresponds to FIG. 6 of the first embodiment.
In FIG. 24, in the fixing device F according to the nineteenth embodiment, the holding members 62 and 63 are formed of the base body insertion portion 6.
2a and 63a are formed so that the outer diameter becomes smaller toward the inner end portion, and a metal ring 64 is mounted between the base insertion portions 62a and 63a and the base 1 as an example of a buffer member. Has been. The metal ring 64 includes an outer portion 64a corresponding to the inner end from the outer end of the base insertion portions 62a and 63a, and an inner portion 64b extending inward from the inner end in the axial direction of the base insertion portions 62a and 63a.
And have. The outer portion 64a is formed so that its inner diameter increases toward the inner side in the axial direction corresponding to the base body insertion portions 62a and 63a. On the other hand, the inner part 64b is formed so as to become thinner as the inner diameter goes inward.
In Example 19, the position of the outer end in the axial direction of the pressure roll Fp is the same as in Example 17,
It is set on the inner side in the axial direction than the base body insertion portions 42a and 43a. Further, the inner end in the axial direction of the metal ring 64 is set to be inside the outer end in the axial direction of the pressure roll Fp.

(Operation of Example 19)
In the fixing device F of Example 19 having the above-described configuration, the metal ring 64 is elastically deformed according to the force received at both ends of the base body 1 that is elastically deformed by contact with the pressure roll Fp, and absorbs the received force. As a result, the stress concentration in the substrate 1 is alleviated. At this time, in Example 19, the thickness becomes thinner as the inner part 64b of the metal ring goes inward, the elastic modulus hardly changes discontinuously, and the relaxation of stress concentration is further increased. Further, the inner end portion in the axial direction of the inner portion 64b is the pressure roll F.
The inner side 64b is arranged so as to overlap the contact area between the base body 1 and the pressure roll Fp. Therefore, compared with the case where the inner part 64b is not provided, the contact pressure is increased in the contact region Q5 between the base 1 and the pressure roll Fp, and the driving of the heating roll Fh is efficiently transmitted to the pressure roll Fp. . That is, in the nineteenth embodiment, the drive is efficiently transmitted while relaxing the stress concentration.

Next, a description will be given of a twentieth embodiment of the present invention. In the description of the twentieth embodiment, the same reference numerals are given to the components corresponding to the components of the first to nineteenth embodiments, and the details thereof will be described. Description is omitted.
Example 20 is different from Examples 1 to 19 in the following points, but is configured in the same manner as Examples 1 to 19 in other points.

FIG. 25 is an explanatory view of the buffer member of the twentieth embodiment, and corresponds to FIG. 6 of the first embodiment.
In FIG. 25, the fixing device F of Example 20 has a heating roll Fh having a metal ring 54 as in Example 13. In Example 20, the position of the outer end in the axial direction of the pressure roll Fp is set on the inner side in the axial direction with respect to the base body insertion portions 52a and 53a, as in Example 17. Further, the inner end in the axial direction of the metal ring 54 is set to be inside the outer end in the axial direction of the pressure roll Fp.

(Operation of Example 20)
In the fixing device F of the twentieth embodiment having the above-described configuration, the stress received by the metal ring 54 elastically deformed at both ends of the base body 1 that is elastically deformed by contact with the pressure roll Fp is absorbed, and the stress in the base body 1 Concentration is eased. At this time, in Example 20, the inner end in the axial direction of the metal ring 54 is inside the outer end in the axial direction of the pressure roll Fp, and the metal ring is in the contact area between the base 1 and the pressure roll Fp. 54 are arranged so as to partially overlap. Therefore, compared with the case where the metal ring 54 is not provided, the contact pressure is increased in the contact region Q5 between the base 1 and the pressure roll Fp, and the driving of the heating roll Fh is efficiently transmitted to the pressure roll Fp. .

Next, a description will be given of Embodiment 21 of the present invention. In the description of Embodiment 21, the same reference numerals are given to the components corresponding to the components of Embodiments 1 to 20, and the detailed description thereof will be made. Description is omitted.
Example 21 is different from Examples 1 to 20 in the following points, but is configured in the same manner as Examples 1 to 20 in other points.

FIG. 26 is an explanatory diagram of the buffer member of the embodiment 21, and corresponds to FIG. 6 of the embodiment 1.
In FIG. 26, in the fixing device F of the twenty-first embodiment, the metal ring 54 ′ is the same as in the fourteenth embodiment.
It has the heating roll Fh which has. In Example 21, the position of the outer end in the axial direction of the pressure roll Fp is set inward in the axial direction with respect to the base body insertion portions 52a and 53a, as in Example 17. Further, the inner end in the axial direction of the metal ring 54 is set to be inside the outer end in the axial direction of the pressure roll Fp.

(Operation of Example 21)
In the fixing device F of Example 21 having the above-described configuration, the force received by the elastic deformation of the metal ring 54 ′ at both ends of the base 1 that is elastically deformed by contact with the pressure roll Fp is absorbed by the base 1. Stress concentration is relaxed. At this time, in Example 21, the inner end in the axial direction of the metal ring 54 ′ is on the inner side of the outer end in the axial direction of the pressure roll Fp, and the metal is in the contact area between the base 1 and the pressure roll Fp. The rings 54 are arranged so as to partially overlap. Therefore, the metal ring 5
Compared with the case where 4 is not provided, the contact pressure is increased in the contact region Q5 between the base 1 and the pressure roll Fp, and the driving of the heating roll Fh is efficiently transmitted to the pressure roll Fp.

Next, a description will be given of a twenty-second embodiment of the present invention. In the description of the twenty-second embodiment, components corresponding to those of the first to twenty-first embodiments are denoted by the same reference numerals, and detailed descriptions thereof will be given. Description is omitted.
Example 22 is different from Examples 1 to 21 in the following points, but is configured in the same manner as Examples 1 to 21 in other points.

FIG. 27 is an explanatory diagram of the buffer member according to the twenty-second embodiment, and corresponds to FIG. 6 according to the first embodiment.
In FIG. 27, the fixing device F of Example 22 has a heating roll Fh having double metal rings 56 and 57 as in Example 15. In Example 22, the pressure roll F
The position of the outer end in the axial direction of p is set inward in the axial direction with respect to the base body insertion portions 52a and 53a, as in the seventeenth embodiment. Further, the inner ends in the axial direction of the metal rings 56 and 57 are both set to be inside the outer end in the axial direction of the pressure roll Fp.

(Operation of Example 22)
In the fixing device F according to the twenty-second embodiment having the above-described configuration, the base ring 1 absorbs the forces received by the metal rings 56 and 57 being elastically deformed at both ends of the base body 1 that is elastically deformed by contact with the pressure roll Fp. The stress concentration is relaxed. At this time, the thin metal spring is doubled, and Example 15
Similarly, the discontinuity of the elastic modulus along the axial direction is relaxed, and the stress concentration is further relaxed compared to the case of the twenty-first embodiment.
In Example 22, the inner ends in the axial direction of the metal rings 56 and 57 are inside the outer end in the axial direction of the pressure roll Fp, and a metal is formed in the contact area between the base 1 and the pressure roll Fp. Ring 5
6,57 are arrange | positioned so that it may overlap partially. Therefore, compared with the case where the metal rings 56 and 57 are not provided, the contact pressure is increased in the contact region Q5 between the base 1 and the pressure roll Fp, and the driving of the heating roll Fh is efficiently transmitted to the pressure roll Fp. Is done.

(Experimental example)
Next, an experiment for confirming the effect of the present invention was performed. Experiments are computer simulations,
This was done by so-called computer simulation. In the experiment, unlike the example, the axial direction of the heating roll Fh and the pressure roll Fp is the Z-axis direction, and the direction from the central axis of the pressure roll Fp to the central axis of the heating roll Fh is the + Y-axis direction. The direction orthogonal to the Z-axis direction and the Y-axis direction is taken as the X-axis direction, and a left-handed XYZ axis is assumed.
In the experiment, the configuration of Experimental Example 10 shown in FIG. 15 was adopted as the configuration of the heating roll Fh, the length of the base 1 in the axial direction was 250 mm, the outer diameter was φ25 mm, and the material was iron.

In the experiment, the pressure roll Fp has an axial length of 250 mm and a diameter of φ12 mm.
A pressure roll in which a rubber layer was formed around the iron shaft was adopted. The rubber layer has a length of 200 mm in the axial direction and an outer diameter of 25 mm, and is modeled as a rubber layer of 1.6 MPa corresponding to the Young's modulus of the member in the fixing region of a belt-type pressure member that is currently commercially available. Turned into.
A commercially available belt-type fixing device is described in, for example, Japanese Patent Application Laid-Open No. 2002-148971 and Japanese Patent Application Laid-Open No. 2002-148972, and is well known in the art, and thus detailed description thereof is omitted.
And on both ends of the shaft of the pressure roll Fp, as contact pressure, so-called nip pressure,
When a force of 100 N was applied in the + Y direction toward the central axis of the heating roll Fh, the stress and displacement acting on the heating roll Fh were measured. As the stress, Mises stress (or von Mises stress) used for determining the yield of a member or the like was adopted.

(Experimental example 1)
In Experimental Example 1, the experiment was performed with the substrate 1 having a thickness of 0.10 mm.
(Comparative Example 1)
In Comparative Example 1, the experiment was performed with the substrate 1 having a thickness of 0.16 mm.
The experimental results are shown in FIGS.

FIG. 28 is an explanatory diagram of the stress distribution in the experimental results, FIG. 28A is an explanatory diagram of Experimental Example 1, and FIG. 28B is an explanatory diagram of Comparative Example 1.
FIG. 29 is an explanatory diagram when the distribution of the displacement of the substrate in the experimental result is viewed from the + Z and + Y sides, FIG. 29A is an explanatory diagram of Experimental Example 1, and FIG. 29B is an explanatory diagram of Comparative Example 1.
FIG. 30 is an explanatory diagram when the distribution of the displacement of the substrate is viewed from the −Z, −Y side in the same experimental results as FIG. 29, FIG. 30A is an explanatory diagram of Experimental Example 1, and FIG. It is explanatory drawing.
FIG. 31 is an explanatory view showing a state in which the distribution of the displacement of the substrate is doubled in the Y-axis direction and emphasized in the same experimental result as FIG. 29, FIG. 31A is an explanatory view of Experimental Example 1, and FIG. FIG.
FIG. 32 is an explanatory view showing a state in which the distribution of the displacement of the substrate is doubled in the Y-axis direction and emphasized in the same experimental result as FIG. 30, FIG. 32A is an explanatory view of Experimental Example 1, and FIG. FIG.
FIG. 33 is an explanatory view of the deformation state in the contact region between the heating roll and the pressure roll in the experimental result, and is a sectional view taken along the line XXXIII-XXXIII of FIG. 33A. FIG. 33B is an explanatory diagram of Comparative Example 1. FIG.
FIG. 34 is an explanatory view of the deformation state in the contact region between the heating roll and the pressure roll in the experimental results, and is a sectional view taken along the line XXXIV-XXXIV of FIG. 34A. FIG. 34B is an explanatory diagram of Comparative Example 1. FIG.
FIG. 35 is an explanatory view of the deformation state in the contact region between the heating roll and the pressure roll in the experimental result, and is a sectional view taken along the line XXXV-XXXV in FIG. 35A. FIG. 35B is an explanatory diagram of Comparative Example 1. FIG.

In FIG. 28 to FIG. 35, as the experimental results, the heating roll Fh and the pressure roll Fp are symmetric with respect to the axial direction with the axial center as a boundary. That is, a half-sized portion from the axial center to the axial end on the + Z side is illustrated, and the range from the axial central to the −Z side axial end is not shown.
In this experimental example, the axial length of the rubber layer of the pressure roll Fp is 200 mm, and the heating roll F
The axial length of the base 1 of h is 250 mm, and the axial end of the rubber layer is 2 from the end of the base 1.
It is in contact with the 5 mm position. In Experimental Example 1 shown in FIG. 28A, stress is concentrated at the end portion of the base body 1 in the axially inner portion of the holding members 42 and 43 from the buffer rubber 44, whereas in FIG. In Comparative Example 1 shown, it was confirmed that the stress was applied substantially uniformly along the region where the rubber layer of the pressure roll Fp was in contact.

In Comparative Example 1 shown in FIGS. 29B to 32B, the displacement in the + Y direction is small, the three-dimensional distortion is small, and the cylindrical shape is almost maintained, whereas the experiment shown in FIGS. 29A to 32A is performed. In Example 1, the pressure roll Fp is closer to the pressure roll Fp toward the axial center side.
The displacement in the + Y direction increases and the cross-sectional shape is distorted from a circle to an ellipse that is long in the X direction. At this time, as shown by the grid-like lines in FIGS. 29 to 32, in Experimental Example 1, three-dimensional distortion is caused corresponding to the inner end portions of the buffer rubber 44 of the holding members 42 and 43. appear.

Therefore, as shown in FIG. 33B, in the conventional heating roll Fh as shown in Comparative Example 1, the base 1 is hardly deformed, and the fixing layer is formed mainly by deformation of the rubber layer of the pressure roll Fp. In contrast, as shown in FIG. 33A, in Experimental Example 1, the holding member 42 is used.
43, the fixing region is formed by deforming not only the rubber layer of the pressure roll Fp but also the base body 1 of the heating roll Fh. At this time, as shown in FIG. 33, in the comparative example 1, the fixing region is curved so as to be recessed toward the pressure roll Fp, whereas in the experimental example 1, in the X-axis direction, that is, the medium conveyance It is almost flat along the direction.

Similarly, in the comparative example 1, the fixing region in which the rubber layer of the pressure roll Fp is mainly recessed also at the position near the end from the center in the axial direction shown in FIG. 34 and the central portion in the axial direction shown in FIG. In contrast, in Experimental Example 1, the heating roll Fp and the pressure roll Fh are both deformed to form a substantially flat fixing region.

(Example 23)
Next, a description will be given of a twenty-third embodiment of the present invention. In the description of the twenty-third embodiment, the same reference numerals are given to the components corresponding to the components of the first embodiment, and the detailed description thereof will be given. Omitted.
Example 23 is different from Example 1 in the following points, but is configured in the same manner as Example 1 in other points.
FIG. 36 is an overall explanatory view of an image forming apparatus according to Embodiment 23 of the present invention.
In FIG. 36, a printer U as an example of an image forming apparatus according to a twenty-third embodiment of the present invention has sheet feed containers TR1 to TR4 in which sheets S as examples of a medium on which an image is recorded are stored. In addition, a paper discharge section TRh is provided on the upper surface.

The printer U of the twenty-third embodiment differs from the printer U of the first embodiment of the electrophotographic method in that it is configured by an ink jet recording type printer. Is arranged. The head unit HU is
It is supported by a carriage CG as an example of a scanning member, and the carriage CG is supported so as to be movable in the left-right direction along an axis CG1 extending in the medium width direction. The head unit H
U records an image by ejecting ink while the carriage CG moves in the direction of the axis CG1 on the sheet S conveyed by the registration roll Rr and passing through the image recording area Q1. The head unit HU and the carriage CG are disclosed in, for example, Japanese Patent Laid-Open No. 2005-2.
No. 25044 and the like, which are well known in the art, and will not be described in detail.

FIG. 37 is an explanatory diagram of a main part of the discharge roller of the twenty-third embodiment.
In FIG. 36, a discharge roller Rh ′ as an example of a medium transport member is disposed on the downstream side of the image recording area Q1. In FIG. 37, the discharge roller Rh ′ of Example 23 is
It has a heating roller 71 as an example of a driving member and an example of a cylindrical rotating member, and a driven roller 72 as an example of a driven member disposed to face the heating roller 71. The heating roller 71 and the driven roller 72 of the twenty-third embodiment are the heating roller F of the fixing device F of the first embodiment.
The configuration is the same as h and the pressure roller Fp.

In FIG. 37, the heating roller 71 of Example 23 is provided with power supply terminals 71a at both ends of the inner peripheral surface on the side in contact with the driven roller 72. The power supply terminal 71a includes a power supply device. Power is supplied from 73. Therefore, the heating roller 71 of the twenty-third embodiment is configured to generate heat due to power feeding and the electric resistance of the base of the heating roller 71. That is, in Example 23, the heating roller 71 itself is a heat source member.
The registration roller Rr, the medium conveyance roller Ra, the discharge roller Rh ′ and the like constitute the medium conveyance device of the twenty-third embodiment.

(Operation of Example 23)
In the printer U according to the twenty-third embodiment having the above-described configuration requirements, the sheet S on which image recording has been performed by the ink jet recording method by discharging ink from the head unit HU is performed on the discharge roller R.
It is conveyed to h ′. The sheet S conveyed to the discharge roller Rh ′ is discharged to the discharge portion TRh while being heated by the heating roller 71 when passing through the contact area between the heating roller 71 and the driven roller 72. Therefore, drying of the sheet S moistened with ink is promoted by heating, and the sheet S is discharged in a dry state to the discharge portion TRh. At this time, in Example 23,
The contact area is widened by elastic deformation of the heating roller 71, and heating is performed efficiently. Therefore, when the sheets S are stacked, image defects such as ink permeating into other sheets S are reduced, and the trouble of drying the sheets S is omitted, and the sheets S discharged to the discharge unit TRh are used quickly. It is possible.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is performed within the range of the summary of this invention described in the claim. It is possible. Modification examples (H01) to (H05) of the present invention are exemplified below.
(H01) In the above-described embodiment, the printer as the image forming apparatus has been exemplified. However, the present invention is not limited to this, and a FAX, a copying machine, or a multifunction machine having all or a plurality of functions may be used. Further, the image forming apparatus is not limited to a multi-color developing image forming apparatus, and may be configured by a monochromatic, so-called monochrome image forming apparatus. Further, the present invention is not limited to the configuration in which the image is transferred directly from the image carrier to the medium, and can be applied to a configuration using an intermediate transfer body.

(H02) In the above-described embodiments, the configurations exemplified in the embodiments can be combined and combined. For example, the configuration of the nineteenth embodiment can be applied to the third, fourth, sixth, and eleventh embodiments, and the twelfth embodiment can be applied to other embodiments.
(H03) In Examples 15 and 22, the metal ring is doubled, but it can be tripled or more.
(H04) In the above embodiment, the pressure roll Fp is exemplified as the pressure fixing member. However, the pressure roll is not limited to the roll shape, and any conventionally known shape can be used. For example, an endless belt-like pressure fixing member, a so-called pressure belt, a non-rotating massive pressure fixing member, a so-called pressure pad, or the like can be used. The pressure belt is described in Japanese Patent Application Laid-Open No. 2006-119677, Japanese Patent Application Laid-Open No. 2006-251622, Japanese Patent Application Laid-Open No. 2005-202158, or the like, and is conventionally known.

(H05) In the above-described embodiment, the case where the cylindrical rotating member is used as the heat fixing member for the fixing device F is exemplified. However, the present invention is not limited to this configuration. It is also possible to use a cylindrical rotating member having the substrate 1. For example, in an image forming apparatus, a cylindrical rotating member having a heat source member incorporated therein is disposed on the downstream side of the fixing device F, and this occurs due to variations in evaporation of moisture in the medium when passing through the fixing device F. The medium can be heated to correct curving and undulation, so-called curl, and used to remove curl.

1 is a perspective explanatory view of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is an overall explanatory view of the image forming apparatus according to the first embodiment of the present invention. FIG. 3 is an explanatory perspective view of the image forming apparatus according to the first exemplary embodiment of the present invention with the side cover opened. FIG. 4 is an enlarged cross-sectional view of the fixing device according to the first exemplary embodiment. FIG. 5 is an explanatory view of the main part of the VV line cross section of FIG. FIG. 6 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the first exemplary embodiment. FIG. 7 is a main part enlarged explanatory view of the end portion in the axial direction of the fixing device of the second embodiment, and corresponds to FIG. 6 of the first embodiment. FIG. 8 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the third embodiment, and corresponds to FIG. 6 according to the first embodiment. FIG. 9 is an enlarged explanatory view of the main part of the axial end of the fixing device according to the fourth embodiment, and corresponds to FIG. 6 according to the first embodiment. FIG. 10 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the fifth embodiment, and corresponds to FIG. 6 according to the first embodiment. FIG. 11 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the sixth embodiment, and corresponds to FIG. 6 according to the first embodiment. FIG. 12 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the seventh embodiment, FIG. 12A is a diagram corresponding to FIG. 6 of the first embodiment, and FIG. FIG. FIG. 13 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the eighth embodiment, and corresponds to FIG. 6 according to the first embodiment. FIG. 14 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the ninth embodiment. FIG. 14A is a sectional view of the holding member, and FIG. 15 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the tenth embodiment, and corresponds to FIG. 6 according to the first embodiment. FIG. 16 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the eleventh embodiment, corresponding to FIG. 6 according to the first embodiment. FIG. 17 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the twelfth embodiment, and corresponds to FIG. 5 according to the first embodiment. 18 is an enlarged explanatory view of a main part of an axial end portion of the fixing device according to the thirteenth embodiment, FIG. 18A is a view corresponding to FIG. 6 of the first embodiment, and FIG. 18B is a perspective explanatory view of a buffer member. 19 is an enlarged explanatory view of a main part of an axial end portion of the fixing device of Example 14, FIG. 19A is a view corresponding to FIG. 6 of Example 1, and FIG. 19B is a perspective explanatory view of a buffer member. FIG. 20 is an enlarged explanatory view of the main part of the axial end portion of the fixing device according to the fifteenth embodiment, corresponding to FIG. 6 according to the first embodiment. FIG. 21 is an explanatory view of a buffer member of Example 16, FIG. 21A is an explanatory view of a state in which two metal rings are detached, FIG. 21B is a sectional view along the axial direction in FIG. 21A, and FIG. It is sectional drawing of the state in which the ring was piled up. FIG. 22 is an explanatory diagram of the buffer member according to the seventeenth embodiment and corresponds to FIG. 6 according to the first embodiment. FIG. 23 is an explanatory diagram of the buffer member of the eighteenth embodiment and corresponds to FIG. 6 of the first embodiment. FIG. 24 is an explanatory diagram of the buffer member of the nineteenth embodiment and corresponds to FIG. 6 of the first embodiment. FIG. 25 is an explanatory diagram of the buffer member of the twentieth embodiment, and corresponds to FIG. 6 of the first embodiment. FIG. 26 is an explanatory diagram of the buffer member according to the twenty-first embodiment and corresponds to FIG. 6 of the first embodiment. FIG. 27 is an explanatory diagram of the buffer member according to the twenty-second embodiment, and corresponds to FIG. 6 according to the first embodiment. FIG. 28 is an explanatory diagram of the stress distribution in the experimental results, FIG. 28A is an explanatory diagram of Experimental Example 1, and FIG. 28B is an explanatory diagram of Comparative Example 1. FIG. 29 is an explanatory diagram when the distribution of the displacement of the substrate in the experimental result is viewed from the + Z and + Y sides, FIG. 29A is an explanatory diagram of Experimental Example 1, and FIG. 29B is an explanatory diagram of Comparative Example 1. FIG. 30 is an explanatory diagram when the distribution of the displacement of the substrate is viewed from the −Z, −Y side in the same experimental results as FIG. 29, FIG. 30A is an explanatory diagram of Experimental Example 1, and FIG. It is explanatory drawing. FIG. 31 is an explanatory view showing a state in which the distribution of the displacement of the substrate is doubled in the Y-axis direction and emphasized in the same experimental result as FIG. 29, FIG. 31A is an explanatory view of Experimental Example 1, and FIG. FIG. FIG. 32 is an explanatory view showing a state in which the distribution of the displacement of the substrate is doubled in the Y-axis direction and emphasized in the same experimental result as FIG. 30, FIG. 32A is an explanatory view of Experimental Example 1, and FIG. 32B is a comparative example. FIG. FIG. 33 is an explanatory view of the deformation state in the contact region between the heating roll and the pressure roll in the experimental result, and is a sectional view taken along line XXXIII-XXXIII in FIG. 33A. FIG. 33A is an explanatory view of Experimental Example 1, FIG. 33B is an explanatory diagram of Comparative Example 1. FIG. FIG. 34 is an explanatory view of the deformation state in the contact region between the heating roll and the pressure roll in the experimental result, and is a sectional view taken along the line XXXIV-XXXIV of FIG. 34A. FIG. 34A is an explanatory view of FIG. 34B is an explanatory diagram of Comparative Example 1. FIG. FIG. 35 is an explanatory view of the deformation state in the contact region between the heating roll and the pressure roll in the experimental result, and is a sectional view taken along the line XXXV-XXXV in FIG. 35A. FIG. 35A is an explanatory view of FIG. 35B is an explanatory diagram of Comparative Example 1. FIG. FIG. 36 is an overall explanatory view of an image forming apparatus according to Embodiment 23 of the present invention. FIG. 37 is an explanatory diagram of a main part of the discharge roller of the twenty-third embodiment.

1 ... Substrate,
2, 3, 2 ', 3', 22, 23, 22 ', 23', 32, 33, 32 ', 33', 32
″, 33 ″, 42, 43, 52, 53, 52 ′, 53 ′, 52 ″, 53 ″, 62, 63.
Holding part,
2a, 3a, 22a, 23a, 32a, 33a, 32a ", 33a", 42a, 43a,
52a, 53a, 52a ′, 53a ′, 62a, 63a...
2b, 3b, 2b ', 3b', 22b, 23b, 22b ', 23b', 32b, 33b,
42b, 43b, 52b, 53b, 52b ′, 53b ′, 62b, 63b...
71 ... Cylindrical rotating member,
F: Fixing device,
Fh: Heat fixing member, cylindrical rotating member, medium conveying member,
Fha ... bearing member,
Fp: Pressure fixing member,
Gy, Gm, Gc, Gk ... developing device,
h1, h2 ... heat source members,
Py, Pm, Pc, Pk ... image carrier,
Q5 ... contact area,
Rh ′: medium conveying member,
ROS ... latent image forming device,
S ... medium
SH: Medium transport path,
T1y, T1m, T1c, T1k ... transfer device,
U: Image forming apparatus.

Claims (6)

A heat fixing member that is rotatably supported and heated;
A pressure fixing member supported in a state of being pressed against the heat fixing member;
A fixing device for fixing an unfixed image on a medium surface between the heat fixing member and the pressure fixing member,
The heat fixing member is
A metal cylindrical and elastically deformable base extending in the medium width direction intersecting the medium conveying direction;
A base body insertion portion having an outer peripheral surface having a circular cross section perpendicular to the axial direction and inserted into the base body from an axial end portion of the cylindrical base body; and an axial outer end of the base body insertion portion. The bearing portion is disposed and supported rotatably by the bearing member, and is supported between the outer peripheral surface of the base body insertion portion and the inner peripheral surface of the base body, and is elastically deformed according to the elastic deformation of the base body. A buffer member that relieves stress concentration on the substrate, the buffer member having an axially inner end disposed on the same side or on the inner side with respect to the axially inner end of the substrate insertion portion , A holding member that holds the axial end in a cylindrical shape;
A heat source member extending in the axial direction of the cylindrical base body and spaced from the inner surface of the base body;
Have
The heat fixing member, when passing through the fixing portion to be rotated to fix the unfixed image of the medium surface is elastically deformed without placing member inscribed in the metal cylindrical inner surface of the fixing unit A fixing device characterized in that pressure is applied to the medium and heat is applied by increasing the contact area with the medium, and the elastic member is restored after being rotated and passed through a fixing unit in contact with the medium. A heat fixing member that is rotatably supported and heated;
A pressure fixing member supported in a state of being pressed against the heat fixing member;
A fixing device for fixing an unfixed image on a medium surface between the heat fixing member and the pressure fixing member,
The heat fixing member is
A metal cylindrical and elastically deformable base extending in the medium width direction intersecting the medium conveying direction;
A base body insertion portion that is inserted into the inside of the base body from an axial end portion of the cylindrical base body and has a circular outer peripheral surface in a cross section orthogonal to the axial direction, and goes in the axial direction inside the base body. The base insertion portion formed so that the outer diameter of the outer surface becomes smaller and the inner end in the axial direction is arranged on the inner side of the outer end in the axial direction of the pressure fixing member, and the shaft of the base insertion portion A bearing member disposed at an outer end in the direction and rotatably supported by a bearing member, and holding the axial end of the base body in a cylindrical shape,
A heat source member extending in the axial direction of the cylindrical base body and spaced from the inner surface of the base body;
Have
The pressure fixing member has an axial outer end disposed between the axial outer end of the base and the axial inner end of the holding member in the axial direction,
The heat fixing member, when passing through the fixing portion to be rotated to fix the unfixed image of the medium surface is elastically deformed without placing member inscribed in the metal cylindrical inner surface of the fixing unit A fixing device characterized in that pressure is applied to the medium and heat is applied by increasing the contact area with the medium, and the elastic member is restored after being rotated and passed through a fixing unit in contact with the medium. A heat fixing member that is rotatably supported and heated;
A pressure fixing member supported in a state of being pressed against the heat fixing member;
A fixing device for fixing an unfixed image on a medium surface between the heat fixing member and the pressure fixing member,
The heat fixing member is
A metal cylindrical and elastically deformable base extending in the medium width direction intersecting the medium conveying direction;
A base body insertion portion that is inserted into the inside of the base body from the axial end portion of the cylindrical base body and has a circular outer peripheral surface in a cross section perpendicular to the axial direction, and goes inward in the axial direction of the base body. The base insert portion formed so that the thickness in the radial direction becomes thinner and the inner end in the axial direction is disposed inside the outer end in the axial direction of the pressure fixing member; A bearing member disposed at an end and rotatably supported by a bearing member, and holding the axial end of the base body in a cylindrical shape,
A heat source member extending in the axial direction of the cylindrical base body and spaced from the inner surface of the base body;
Have
The pressure fixing member has an axial outer end disposed between the axial outer end of the base and the axial inner end of the holding member in the axial direction,
The heat fixing member, when passing through the fixing portion to be rotated to fix the unfixed image of the medium surface is elastically deformed without placing member inscribed in the metal cylindrical inner surface of the fixing unit A fixing device characterized in that pressure is applied to the medium and heat is applied by increasing the contact area with the medium, and the elastic member is restored after being rotated and passed through a fixing unit in contact with the medium. The base body insertion portion in which a plurality of grooves extending from an inner end to an outer end portion along the axial direction of the base body are formed;
The fixing device according to claim 3, further comprising: The fixing device according to claim 1, wherein the base body is elastically deformed in a planar shape along a medium conveyance direction in the fixing unit. An image carrier,
A latent image forming apparatus for forming a latent image on the surface of the image carrier;
A developing device for developing the latent image on the surface of the image carrier into a visible image;
A transfer device for transferring a visible image on the surface of the image carrier to a medium;
The fixing device according to claim 1, wherein the fixing device fixes a visible image on the surface of the medium.
An image forming apparatus comprising: