JPH11338288A - Fixing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize instantaneous heating by providing a heat absorption layer on the outside of a light transmissive base substance so that a roll type rotating member for heat ray fixing may be formed and providing a heat uniformizing roller having elasticity to abut on the rotating member for heat ray fixing. SOLUTION: A 1st heat ray fixing roller 17a functioning as the rotating member for heat ray fixing which fixes a toner image being a surface image is provided with the cylindrical light transmissive base substance 171a, the heat absorption layer 171b and a releasing layer 171c on the outside of the base substance 171a in this order. It is constituted as a hard roller where a heat ray irradiation member 171g being a heat ray irradiation means using a halogen lamp or a xenon lamp, for example, is arranged inside the base substance 171a. A heat ray emitted from the member 171g is absorbed by the layer 171b, whereby the roll-type rotating member for heat ray fixing capable of realizing the instantaneous heating is formed. On the outside of the roller 17a functioning as the roll type rotating member for heat ray fixing, the heat uniformizing roller TA1 is arranged to abut on the roller 17a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device and an image forming apparatus for a copying machine, a printer, a facsimile, etc., and more particularly to a fixing device for quick start fixing capable of instantaneous heating and an image forming apparatus using the same.

[0002]

2. Description of the Related Art Conventionally, as a fixing device used in an image forming apparatus such as a copying machine, a printer, a facsimile, etc., a heat roller fixing method has been used as a fixing device having high technical perfection and stability. Machine to full-color machine,
Has been widely adopted.

However, in the conventional heat roller fixing type fixing device, it is necessary to heat the fixing roller having a large heat capacity when heating the transfer material or the toner. Further, there is a problem that it takes time to warm up the fixing device during printing, and the printing time (warming up time) becomes longer.

In order to solve this, a film (heat fixing film) is used, the heat roller is brought to the ultimate thickness of the heat fixing film to reduce the heat capacity, and a temperature-controlled heater (ceramic heater) is directly applied to the heat fixing film. A fixing device of a film fixing type and an image forming device using the same have been proposed, which greatly improve the heat conduction efficiency by being brought into contact with a pressure and achieve a quick start that requires little energy and a little warm-up time. Have been

Further, as a modification of the heat roller, a light-transmissive substrate is used as a fixing roller, and the toner is heated and fixed by irradiating a toner with a heat ray from a halogen lamp provided therein, so that a quick start is achieved without requiring a warm-up time. The fixing method is described in JP-A-52-106741 and JP-A-57-82.
Nos. 240, 57-102736 and 57-
No. 102741 discloses this.

[0006]

However, the method disclosed in Japanese Patent Application Laid-Open No. 52-106741 or the like for irradiating the heat rays of a halogen lamp through a light-transmissive substrate to heat and fix the toner involves energy saving and warming-up. Although a quick start with a reduced time was achieved, the heat conductivity of the light-transmitting substrate was poor, and the temperature of the fixing roller (roll-shaped rotating member for hot-wire fixing) was not uniform, so that especially the transfer material passed through Due to the difference in the size, a temperature fluctuation occurs between the paper passing portion and the non-paper passing portion, causing a problem that fixing unevenness occurs.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, uniforms the temperature of the roll-shaped rotating member for hot-wire fixing, prevents temperature fluctuation of the rotating member for hot-wire fixing, and enables instantaneous heating or heating time. It is an object of the present invention to provide a fixing device using a heat ray for quick start fixing.

Further, the present invention solves the above-mentioned problems, uniforms the temperature of the roll-shaped rotating member for hot-wire fixing using a hot wire, and prevents the temperature fluctuation of the rotating member for hot-wire fixing to prevent fusing. Another object of the present invention is to provide an image forming apparatus capable of instantaneous heating or quick start fixing with a short heating time while preventing the occurrence of unevenness.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a fixing device for fixing a toner image on a transfer material to the transfer material by heating and pressurizing. A heat-absorbing layer is provided on the outside of the light-transmitting substrate to form a roll-shaped heat-ray fixing rotating member, and a heat uniform roller having elasticity is applied to the heat-ray fixing rotating member. This is achieved by a fixing device characterized by being provided in contact with the fixing device (first invention).

Another object of the present invention is to provide a fixing device for fixing a toner image on a transfer material to the transfer material by heating and pressurizing, wherein a cylindrical heat-transmissive means for internally radiating heat rays is provided. A heat-absorbing layer and an elastic layer are provided on the outside of the base and the light-transmitting base to form a roll-shaped rotating member for fixing a heat ray, and a heat equalizing roller is brought into contact with the rotating member for fixing the heat ray. This is achieved by a fixing device characterized in that the fixing device is provided (second invention).

Another object of the present invention is to form an image by forming a toner image on an image forming body, transferring the toner image onto a transfer material, and fixing the toner image on the transfer material by heating and pressing. In the apparatus, a cylindrical light-transmitting substrate in which a heat-ray irradiating means for emitting heat rays is disposed, and a heat-ray absorbing layer is provided outside the light-transmitting substrate to form a roll-shaped heat-ray fixing rotating member. The image forming apparatus is characterized in that a fixing device is provided in which a heat uniform roller having elasticity is provided in contact with the rotating member for fixing heat rays, and heating is controlled in accordance with the passage of the transfer material. (Third invention).

Another object of the present invention is to form an image by forming a toner image on an image forming body, transferring the toner image onto a transfer material, and fixing the toner image on the transfer material by heating and pressing. In the apparatus, there is provided a cylindrical light-transmissive substrate in which a heat-ray irradiating means for emitting heat rays is disposed, and a heat-ray absorbing layer and an elastic layer provided outside the light-transmissive substrate to form a roll-shaped heat ray fixing rotation. An image forming apparatus is provided, wherein a fixing device is provided for forming a member and a heat uniformizing roller is disposed in contact with the rotating member for fixing heat rays, and heating is controlled in accordance with the passage of the transfer material. (4th invention).

[0013]

Embodiments of the present invention will be described below. Note that the description in this column does not limit the technical scope of the claims and the meaning of terms. Also, the following assertive description in the embodiment of the present invention indicates the best mode, and does not limit the meaning of the terms of the present invention or the technical scope. In the following description of the embodiment, in the transfer area, the surface (upper surface) of the transfer material on the side facing the image forming body is the front surface, and the other surface of the transfer material, that is, the transfer material on the side facing the intermediate transfer body. The surface (lower surface) is called a back surface, an image transferred to the front surface of the transfer material is called a front image, and an image transferred to the back surface of the transfer material is called a back image.

An image forming process and each mechanism of an embodiment of a fixing device and an image forming apparatus using the same according to the present invention will be described with reference to FIGS. FIG. 1 is a cross-sectional view of a color image forming apparatus showing an embodiment of a fixing device according to the present invention and an image forming apparatus using the same. FIG. 2 shows a toner image forming state in the image forming apparatus of FIG. FIG. 2A is a diagram showing a toner image forming state when a back surface image formed on an image forming body is transferred onto an intermediate transfer body, and FIG. 2B is a view showing the intermediate transfer body. FIG. 2 is a diagram showing a toner image forming state when a front image is formed on an image forming body in synchronization with an upper back image.
(C) is a diagram showing the formation of a double-sided image on a transfer material,
FIG. 3 is a diagram showing an example of a document image reading unit.
5 is a control circuit block diagram of the image forming apparatus, and FIG.
FIG. 6 is an explanatory view showing a structure of a first example of a fixing device. FIG. 6 is an enlarged cross-sectional configuration diagram of a first example of a roll-shaped rotating member for heat ray fixing, and FIG. FIG. 8 is a diagram showing the concentration distribution of the heat ray absorbing layer of the heat ray fixing rotating member, and FIG.
It is a figure which shows the outer diameter and thickness of the translucent base | substrate of the rotating member for heat ray fixing of a roll shape.

As shown in FIGS. 3 and 4, a document image reading device 500 as a document image reading means includes a reading device main body 501, a document storage plate 505 for storing a document PS, a document sending roller 502, and a transparent plate 503. , Document feed roller 504, document discharge tray 506, and transparent plate 503
And a line-shaped document image reading sensor PS1 and PS2 for reading the document image of the document PS from above and below. The control unit is controlled by a signal line incorporated in an external device or a color image forming apparatus described below. Connected.

When the original PS sent by the original sending roller 502 passes through the transparent plate 503, the original PS is converted to a one-sided original by original image reading sensors PS1 and PS2 provided above and below the transparent plate 503. Determination of whether the document is a double-sided document (single-sided or double-sided) and reading of image data of the document PS are performed.

In the present embodiment, one-sided and two-sided discrimination and image data reading are performed by one set of upper and lower sensors. For example, image data may be read after a single-sided or double-sided discrimination has been performed using a plurality of sensors respectively corresponding to each other. Original image reading sensor PS1
Alternatively, the image data of one bundle of originals PS is read by PS2 and stored in the RAM through the control unit.

According to the above, when it is determined that the image is a double-sided image,
The image data of the document PS is read by the document image reading means shown in FIG. 3, and the double-sided image forming program P1 stored in the ROM shown in FIG. P1 is executed, and the image forming process is performed.

1 and 2, reference numeral 10 denotes a photosensitive drum as an image forming body, 11 denotes a scorotron charger as a charging unit for each color, and 12 denotes an exposure optical system as an image writing unit for each color. , 13 are developing devices as developing means for each color, 14
a is an intermediate transfer belt that is an intermediate transfer member, 14c is a transfer device that is a first and a second transfer unit, 14g is a back surface transfer device that is a third transfer unit, 14m is a charge remover that is a charge removing unit,
Reference numeral 150 denotes a paper charger serving as a transfer material charging unit, 14 h denotes a paper separation AC static eliminator serving as a transfer material separating unit, 160 denotes a transport unit having a separation claw 210 serving as a claw member and a spur 162 serving as a spur member, and 169 denotes a spur member. An entry guide plate 17 as an entry guide member is the fixing device of the first example.

The photosensitive drum 10, which is an image forming body, has a transparent conductive layer, a, on the outer periphery of a cylindrical substrate formed of a transparent member such as optical glass or transparent acrylic resin.
A photosensitive layer (also referred to as a photoconductive layer) such as an Si layer or an organic photosensitive layer (OPC), which is rotated clockwise as indicated by an arrow in FIG. 1 with the conductive layer grounded.

A scorotron charger 11, which is a charging unit for each color, an exposure optical system 12, which is an image writing unit for each color, and a developing unit 13, which is a developing unit for each color, form a set of yellow (Y) ), Magenta (M), cyan (C) and black (K) are provided for the image forming processes, and four sets are provided.
With respect to the 0 rotation direction, they are arranged in the order of Y, M, C, and K.

The scorotron charger 11, which is a charging means for each color, has a control grid maintained at a predetermined potential and a discharge electrode 11a composed of, for example, a sawtooth electrode. And installed
The charging operation (in the present embodiment, negative charging) is performed by corona discharge having the same polarity as that of the toner.
A uniform potential is given to 0. As the discharge electrode 11a, a wire electrode or a needle electrode may be used.

Exposure optical system 1 as image writing means for each color
2 indicates that the exposure position on the photosensitive drum 10 is the photosensitive drum 1 with respect to the scorotron charger 11 for each color described above.
It is arranged inside the photoconductor drum 10 so as to be located on the downstream side in the rotation direction of 0. Each exposure optical system 12
Is a linear exposure element 12a in which a plurality of LEDs (light emitting diodes) as light emitting elements of image exposure light arranged in the main scanning direction are arranged in parallel with the drum axis, and a light focusing element as an imaging element. Exposure unit composed of an optical transmission body (trade name: Selfoc lens array) 12b and a lens holder (not shown), which is attached to the holding member 20. In addition to the exposure optical system 12 for each color, a transfer simultaneous exposure unit 12d and a uniform exposure unit 12e are attached to the holding member 20, and are housed integrally within the light-transmitting substrate of the photosensitive drum 10. The exposure optical system 12 for each color performs image exposure of the photosensitive layer of the photosensitive drum 10 from the back side in accordance with image data of each color read by a separate image reading device and stored in the memory, and electrostatically exposes the photosensitive layer on the photosensitive drum 10. Form a latent image. As the exposure element 12a, besides LED, FL (phosphor emission), EL (electroluminescence), PL
It is also possible to use a plurality of light-emitting elements such as (plasma discharge) arranged in an array. The emission wavelength of the image exposure light emitting element usually ranges from 780 to 900 nm, which is highly transparent to the Y, M, and C toners.
In the present embodiment, since the image exposure is performed from the back surface, a shorter wavelength of 400 to 780 nm, which does not have sufficient transparency to the color toner, may be used. Most of the image exposure light is absorbed by the photosensitive layer.

The developing unit 13 which is a developing means for each color keeps a predetermined gap with respect to the peripheral surface of the photosensitive drum 10 and rotates in a forward direction with respect to the rotating direction of the photosensitive drum 10, for example, 0.5 to 1 mm in thickness. And a developing casing 131 formed of a cylindrical nonmagnetic stainless steel or aluminum material having an outer diameter of 15 to 25 mm, and a developing casing 138. Inside the developing casing 138, yellow (Y) and magenta ( M), cyan (C) and black (K) one-component or two-component developers. Each developing unit 13
Is maintained in a non-contact state with the photosensitive drum 10 with a predetermined gap, for example, 100 to 500 μm, by an abutting roller (not shown), and applies a developing bias in which a DC voltage and an AC voltage are superimposed on the developing sleeve 131. By doing
Non-contact reversal development is performed to form a toner image on the photosensitive drum 10.

The intermediate transfer belt 14a is an intermediate transfer member is an endless belt having a volume resistivity of ¹⁰ 10 ~10 ¹⁶ Ω · cm, for example modified polyimide, thermal curing polyimide, ethylene tetrafluoroethylene copolymer, polyvinylidene fluoride A fluorine coating having a thickness of 5 to 50 μm is preferably formed on the outside of a semiconductive film substrate having a thickness of 0.1 to 1.0 mm in which a conductive material is dispersed in an engineering plastic such as nylon alloy or the like, preferably as a toner filming prevention layer. This is a seamless belt having a two-layer structure. As a base of the belt, in addition to the above, a thickness of 0.5 to 2.0 mm in which a conductive material is dispersed in silicon rubber or urethane rubber or the like.
May be used. The intermediate transfer belt 14a is stretched in contact with a driving roller 14d, a ground roller 14j, a driven roller 14e, and a tension roller 14i, which are roller members, and is rotated in a counterclockwise direction indicated by an arrow in FIG. Intermediate transfer belt 14
a, the driven roller 14e, the ground roller 1
4j, a driving roller 14d, and a tension roller 14i are provided in this order. The driven roller 14e, the ground roller 14j, and the driving roller 14d are fixedly rotated, and the tension roller 14i is movably supported by elasticity of a spring (not shown). The tension roller 14i is rotated while stretching the intermediate transfer belt 14a. The drive roller 14d is rotated by a drive from a drive motor (not shown), and drives and rotates the intermediate transfer belt 14a. Intermediate transfer belt 14
a of the ground roller 14j and the driven roller 14e
And the tension roller 14i is driven to rotate. Belt slack of the rotating intermediate transfer belt 14a is tensioned by the tension roller 14i. The recording paper P is separated from the intermediate transfer belt 14a at a curvature portion KT at the end of the intermediate transfer belt 14a stretched around the drive roller 14d on the fixing device 17 side.

Transfer device 14 as first and second transfer means
c denotes the photosensitive drum 10 with the intermediate transfer belt 14a interposed therebetween.
A transfer area 14b is formed between the intermediate transfer belt 14a and the photosensitive drum 10. A DC voltage having a polarity opposite to that of the toner (positive polarity in the present embodiment) is applied to the transfer device 14c, and the toner image on the photosensitive drum 10 is transferred onto the intermediate transfer belt 14a or onto the surface of the recording paper P as a transfer material. Transcribe.

The back transfer unit 14g, which is a third transfer unit, is preferably constituted by a corona discharger, and is a conductive ground roller 14 grounded with the intermediate transfer belt 14a interposed therebetween.
j, a DC voltage having a polarity opposite to that of the toner (positive polarity in the present embodiment) is applied, and the toner image on the intermediate transfer belt 14a is transferred to the back surface of the recording paper P.

The charge eliminator 14m, which is a charge eliminator, is preferably constituted by a corona discharger. 14c is provided in parallel with
An AC voltage on which a DC voltage having the same polarity or opposite polarity to the toner is superimposed is applied, and the charge of the intermediate transfer belt 14a charged by the voltage application of the transfer device 14c is eliminated.

The paper charger 150, which is a transfer material charging means, is preferably constituted by a corona discharger, and is provided to face the driven roller 14e with the intermediate transfer belt 14a interposed therebetween.
Same polarity as toner (minus polarity in this embodiment)
Is applied, and the recording paper P is charged and attracted to the intermediate transfer belt 14a. In addition to the corona discharger, a paper charging brush or a paper charging roller that can abut and release the intermediate transfer belt 14a can be used as the paper charger 150.

Paper separation AC static eliminator 1 as transfer material separating means
4h is preferably formed of a corona discharger, and is provided at an end of the intermediate transfer belt 14a on the side of the fixing device 17 as needed, facing the conductive drive roller 14d grounded with the intermediate transfer belt 14a interposed therebetween. If necessary, an AC voltage in which a DC voltage having the same polarity or opposite polarity to the toner is superimposed is applied, and the recording paper P conveyed by the intermediate transfer belt 14a is discharged and separated from the intermediate transfer belt 14a.

The transport section 160 includes a separation claw 210 which is a claw member.
And a spur member 162 serving as a spur member. The spur member 162 is provided between the fixing device 17 and the curvature portion KT at the end of the intermediate transfer belt 14a on the fixing device 17 side. The transport unit 160 includes the fixing device 1
7, the intermediate transfer belt 14a is deformed, the toner image carried on the intermediate transfer belt 14a tends to be fused, and the transfer is difficult.
4a is prevented from sticking to the toner.

The separation claw 210, which is a claw member, is close to the curvature portion KT of the intermediate transfer belt 14a.
The recording paper P is fixed to the support shaft 221 with a predetermined interval, preferably 0.1 to 2.0 mm, provided when the recording paper P is separated from the intermediate transfer belt 14a.
The leading end of the recording paper P that is to be conveyed while being bent in the direction a is brought into contact with the recording paper P to assist the separation of the recording paper P.

The spur 162, which is a spur member, has a plurality of projections 162a on its peripheral surface, and is provided rotatably about a rotation support shaft 165. The spur 162 guides the back side of the recording sheet P to convey the recording sheet P, prevents the back side toner image of the recording sheet P having the toner image on both sides from being disturbed, and transfers the recording sheet P to the fixing device 17. The recording paper P is stably conveyed to the fixing device 17 while keeping the entering direction constant.

The separation claw 210 and the spur 162 are connected to the curvature portion KT of the intermediate transfer belt 14a and the nip portion T of the fixing device 17.
The surface of the photoconductor drum 1 with respect to a surface PL1 (hereinafter referred to as a transfer material transport surface PL1) connecting an entrance portion (entry portion) of the transfer material to the photoconductor drum 1
On the side opposite to 0, it is disposed in contact with or close to the transfer material transport surface PL1. It is also possible to provide spurs 162 as spur members on both sides of the transfer material transport surface PL1.

An entry guide plate 169 serving as an entry guide member
Is disposed in contact with or close to the transfer material transport surface PL1 on the opposite side of the photosensitive drum 10, and the leading end guides the recording paper P so that the leading end of the recording paper P is prevented from wrinkling during fixing. The fixing device 17 is caused to enter the nip portion T.

The fixing device 17 of the first example is an upper side (front side) for fixing a toner image of a front side image (upper side image).
A first heat ray fixing roller 17a as a roll-shaped heat ray fixing rotating member, and a lower (back side) roll-shaped fixing rotating member for fixing a toner image of a back side image (lower side image). , A first hot-wire fixing roller 17a and a first fixing roller 47a.
The toner image on the recording paper P is fixed by sandwiching the recording paper P in a nip portion T formed between the recording paper P and applying heat and pressure. The first heat ray fixing roller 17a has a heat ray irradiating member 171g as a heat ray irradiating means inside and a first heat ray irradiating member 171g outside.
Heat uniformizing roller TA1 in contact with heat ray fixing roller 17a
Is provided.

Next, the image forming process will be described.

The photosensitive drum 10 is rotated clockwise as indicated by an arrow in FIG. 1 by starting a photosensitive member driving motor (not shown) at the start of image recording, and is simultaneously exposed to light by the charging action of a yellow (Y) scorotron charger 11. Body drum 1
Application of a potential to 0 starts.

After a potential is applied to the photosensitive drum 10, image writing is started by the first exposure signal, that is, an electric signal corresponding to the Y image data, by the Y exposure optical system 12. An electrostatic latent image corresponding to the Y image of the original image is formed on the front surface.

The latent image is reversal-developed in a non-contact state by the Y developing device 13, and a yellow (Y) toner image is formed on the photosensitive drum 10.

Next, a potential is applied to the photosensitive drum 10 from above the Y toner image by the charging action of the magenta (M) scorotron charger 11, and the second color signal, that is, the M color signal, is applied by the M exposure optical system 12. Image writing is performed by an electric signal corresponding to the image data, and the magenta (M) toner image is superimposed on the yellow (Y) toner image by non-contact reversal development by the M developing unit 13. It is formed.

By the same process, the cyan (C) toner image corresponding to the third color signal is further superimposed by the cyan (C) scorotron charger 11, the exposure optical system 12 of C, and the developing device 13 of C. The black (K) toner image corresponding to the fourth color signal is sequentially superimposed thereon by a black (K) scorotron charger 11, an exposure optical system 12 for K, and a developing device 13 for K. A superimposed color toner image of four colors of yellow (Y), magenta (M), cyan (C) and black (K) is formed on the peripheral surface within one rotation of the photosensitive drum 10. (Toner image forming means).

These Y, M, C and K exposure optical systems 12
Image writing on the photosensitive layer of the photosensitive drum 10 is performed from the inside of the drum through the above-described translucent substrate. Therefore, the writing of the images corresponding to the second, third and fourth color signals is performed without any influence from the previously formed toner image, and is equivalent to the image corresponding to the first color signal. Can be formed.

The superimposed color toner image, which is the back image formed on the photosensitive drum 10 as the image forming body by the above image forming process, is transferred to the transfer area 14b.
By the transfer device 14c as a first transfer unit, the transfer (1) is collectively performed on the intermediate transfer belt 14a as the intermediate transfer body.
The next transfer is performed (FIG. 2A). At this time, uniform exposure may be performed by the simultaneous transfer exposure device 12d provided inside the photoconductor drum 10 so that good transfer is performed.

After the toner remaining on the peripheral surface of the photosensitive drum 10 after the transfer is subjected to static elimination by the photosensitive drum AC static eliminator 16, the toner is transferred to a cleaning device 19 as image forming body cleaning means, The toner is cleaned by a cleaning blade 19a made of a rubber material in contact with the toner, and collected by a screw 19b in a toner discharge container (not shown). Further, the peripheral surface of the photosensitive drum 10
For example, a uniform exposure device 12 before charging using a light emitting diode
The history of the photosensitive drum 10 in the previous image formation is eliminated by the exposure by e.

The charge on the intermediate transfer belt 14a charged by the transfer unit 14c is removed by a charge removal unit 14m, which is a charge removal unit provided in parallel with the transfer unit 14c.

After the superimposed color toner image (second toner image) serving as the back surface image is formed on the intermediate transfer belt 14a as described above, the above-described color image forming process is performed on the photosensitive drum 10. Similarly, a superimposed color toner image (first toner image) to be a surface image continuously
Is formed (FIG. 2B). At this time, the photosensitive drum 1
The image data is changed so that the front side image formed on 0 is a mirror image of the back side image formed on the photosensitive drum 10.

With the formation of a surface image on the photosensitive drum 10, recording paper P, which is a transfer material, is sent out by a feed roller 15a from a paper feed cassette 15 which is a transfer material storage means. Timing roller 1
5b, and driven by the timing roller 15b, the first toner image formed on the photosensitive drum 10 is a surface toner color toner image and the intermediate transfer belt 14
The sheet is fed to the transfer area 14b in synchronization with the color toner image of the back side image, which is the second toner image carried on the transfer area 14b. At this time, the fed recording paper P is charged to the same polarity as the toner by a paper charger 150 which is a transfer material charging means provided on the surface side of the recording paper P, and the intermediate transfer belt 14a
And is fed to the transfer area 14b. By charging the paper with the same polarity as that of the toner, the toner is prevented from being attracted to the toner image on the intermediate transfer belt 14a and the toner image on the photosensitive drum 10, thereby preventing the toner image from being disturbed.

In the transfer area 14b, a second voltage to which a voltage having a polarity opposite to that of the toner (positive polarity in this embodiment) is applied.
The surface image on the photosensitive drum 10 is collectively transferred to the surface of the recording paper P by the transfer device 14c as the transfer means (2).
Next transfer). At this time, the back side image on the intermediate transfer belt 14a is not transferred to the recording paper P, and the intermediate transfer belt 1
4a. Transfer device 14 as second transfer means
In the case of secondary transfer by c, so that good transfer is performed,
The uniform exposure may be performed by a simultaneous transfer exposure device 12d using, for example, a light emitting diode, provided inside the photosensitive drum 10 so as to face the transfer area 14b. Further, the intermediate transfer belt 14a charged by the transfer device 14c
Is removed by the charge remover 14m.

The recording paper P on which the color toner image has been transferred to the front surface is conveyed to a back transfer device 14g as a third transfer means to which a voltage having a polarity opposite to that of the toner (positive polarity in this embodiment) is applied. Then, the back side image on the peripheral surface of the intermediate transfer belt 14a is collectively transferred (tertiary transfer) to the back side of the recording paper P by the back side transfer unit 14g (FIG. 2C).

The recording paper P on which the color toner images are formed on both sides is formed by the curvature of the curvature portion KT of the intermediate transfer belt 14a and the paper as transfer material separating means provided at the end of the intermediate transfer belt 14a as necessary. The spur 162 provided on the transport unit 160 is separated from the intermediate transfer belt 14a by the static elimination action of the separation AC neutralizer 14h and the separation claw 210 provided on the transport unit 160 at a predetermined interval from the intermediate transfer belt 14a. Then, the toner image is stably conveyed to the fixing device 17 through the entry guide plate 169, and the leading end portion is sent to the nip portion T of the fixing device 17 by the entry guide plate 169 to fix the toner image of the surface image (upper image). A first heat ray fixing roller 17a disposed on an upper side, and a first fixing roller disposed on a lower side for fixing a toner image of a back image (lower image) The toner image on the recording sheet P is fixed by being added to the heat and pressure at the nip portion T between 7a. The recording paper P on which double-sided image recording has been performed is sent upside down, and is discharged by a discharge roller 18 to a tray outside the apparatus. Further, as shown by a dashed line in FIG. 1, a switching member (not shown) may be provided at the exit of the fixing device 17 so that the sheet is discharged to a tray outside the device without turning over.

The toner remaining on the peripheral surface of the intermediate transfer belt 14a after the transfer is provided opposite to the driven roller 14e with the intermediate transfer belt 14a interposed therebetween, and is applied to the intermediate transfer belt 14a with the support shaft 142 as a rotation fulcrum. The intermediate transfer member is cleaned by an intermediate transfer member cleaning device 140 which is an intermediate transfer member cleaning unit having an intermediate transfer member cleaning blade 141 capable of contacting and releasing contact.

The toner remaining on the peripheral surface of the photoreceptor drum 10 after the transfer is removed by a photoreceptor drum AC static eliminator 16 and then cleaned by a cleaning device 19. By 12e, the history of the photosensitive drum 10 in the previous image formation is canceled, and the next image formation cycle is started.

Since the superimposed color toner images are collectively transferred by using the above-described method, color shift of the color image on the intermediate transfer belt 14a, scattering or rubbing of the toner, and the like are less likely to occur, and the image deterioration is small. Double-sided color image formation is performed.

In the original image reading apparatus 500,
When the image data of the document PS read by the document image reading unit shown in FIG. 3 is copied as a single-sided image of only the surface of the photosensitive drum 10 when the image is determined to be a single-sided image or a double-sided image The RO shown in FIG.
A single-sided image forming program P2 of the front surface by the photosensitive drum 10 as an image forming body stored in M is read into the RAM through the control unit, and the single-sided image forming program P2 of the front surface is executed by the control unit. The described image forming process of only the surface by the photosensitive drum 10 is continuously performed.

The image data of the document PS read by the document image reading means shown in FIG. 3 when it is determined that the image is a single-sided image or when it is determined that the image is a double-sided image is a single-sided image of only the back surface by the intermediate transfer belt 14a. In the case of copying as an image, a single-sided image forming program P3 on the back side by the intermediate transfer belt 14a as an intermediate transfer body stored in the ROM shown in FIG. The image forming program P3 is executed, and the image forming process for only the back surface by the intermediate transfer belt 14a described in FIG. 1 is continuously performed.

Although the embodiment of the fixing device and the image forming apparatus of the present invention has been described with reference to color image formation, the present invention is not necessarily limited to this, and is described with reference to FIGS. The present invention is also applicable to monochrome single-sided or double-sided image formation by the same process. Further, although the embodiments of the fixing device and the image forming apparatus of the present invention have been described with reference to the double-sided image forming apparatus, the present invention is not necessarily limited to this, and the fixing device described below is also applicable to the double-side fixing. However, the present invention is not limited to this, and may be used as a single-side fixing device.

As shown in FIG. 5, the fixing device 1 of the first example
Reference numeral 7 denotes an upper (front side) first heat ray fixing roller 17a as a roll-shaped heat ray fixing rotating member for fixing a toner image of a front side image (upper side image), and a back side image (lower side image). Fixing roller 47 as a lower (back side) roll-shaped fixing rotating member for fixing the toner image
a, the first heat ray fixing roller 17a and the first
The recording paper P is nipped by a nip portion T formed between the recording paper P and the fixing roller 47a, and heat and pressure are applied to the recording paper P to thereby fix the recording paper P.
The upper toner image is fixed.

The first heat ray fixing roller 17a as a heat ray fixing rotating member for fixing the toner image of the front image is
Cylindrical translucent substrate 171a, and translucent substrate 171a
The heat ray absorbing layer 171b and the release layer 171
c are provided in that order, and a hard roller having a heat ray irradiating member 171g serving as a heat ray irradiating means using, for example, a halogen lamp or a xenon lamp is arranged inside the translucent substrate 171a. The heat ray emitted from the heat ray irradiating member 171g is absorbed by the heat ray absorbing layer 171b to form a roll-shaped heat ray fixing rotating member capable of instantaneous heating (the first heat-fixing roll-shaped rotating member for instant heating). Example).
A heat uniformizing roller TA1 is provided outside the first heat ray fixing roller 17a as a roll-shaped heat ray fixing rotating member in contact with the first heat ray fixing roller 17a.

The first fixing roller 4 as a roll-shaped fixing rotating member for fixing the toner image of the back side image.
7a is a cylindrical metal pipe 4 made of, for example, an aluminum material.
And a rubber roller 471b having a thickness of 2 to 20 mm using, for example, a silicon material on the outer peripheral surface of the metal pipe 471a.
And a soft roller in which a halogen heater 471c is disposed inside a metal pipe 471a. A nip portion T having a convex lower side is formed between the upper hard roller and the lower soft roller, and the toner image is fixed.

TS1 is an upper first heat ray fixing roller 17a.
Is a temperature sensor using, for example, a thermistor for performing temperature control, and TS2 is a temperature sensor using, for example, a thermistor for performing temperature control, which is mounted on the lower first fixing roller 47a.

In the above, the first heat ray fixing roller 1 as a heat ray fixing rotating member formed as a hard roller
As the heat equalizing roller TA1 to be in contact with 7a, for example, metal powder having good thermal conductivity, such as aluminum, iron, and stainless steel, or titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate, etc. A soft type (elastic) rubber roller mixed with metal oxide fine particles and having good thermal conductivity, or a rubber roller with a heat pipe inside is used. First heat ray fixing roller 17 due to elasticity of heat equalizing roller TA1
a, the heat transfer between the first heat ray fixing roller 17a and the heat equalizing roller TA1 is performed satisfactorily, and the heat uniformizing roller TA1 having a uniform surface temperature distributes heat to be described later. The temperature unevenness on the surface of the first heat ray fixing roller 17a using the translucent substrate 171a having a low efficiency is made uniform. Further, the temperature variation between the paper passing portion and the non-paper passing portion is made uniform by the difference in the size of the transfer material to be passed. Thus, the occurrence of uneven fixing of the toner image on the transfer material to be fixed is prevented.

The heat uniformizing roller TA1 is a hard type metal roller having good thermal conductivity, for example, using an aluminum material or a stainless steel material. And the temperature of the surface of the first heat ray fixing roller 17a can be made uniform in the same manner as described above by using a hard type metal roller including a heat pipe in the heat equalizing roller TA1. However, since both the first heat ray fixing roller 17a and the heat equalizing roller TA1 are of a hard type, the contact between them becomes a line contact or a discontinuous line contact, and the mutual heat transfer is not performed well. Not very good.

Further, according to FIG. 6, the first heat ray fixing roller 1
As shown in the cross section in FIG. 6A, the configuration of 7a is such that a heat ray irradiating member 171g is used as the cylindrical translucent substrate 171a.
For example, a ceramic material such as Pyrex glass, sapphire (Al ₂ O ₃ ), or CaF ₂ that transmits heat rays such as infrared rays or far infrared rays, or a translucent resin using polyimide, polyamide, or the like is used. Since the wavelength of the heat ray passing through the light-transmitting substrate 171a is 0.1 to 20 μm, and preferably 0.3 to 3 μm, an adjuster for hardness and thermal conductivity is added as a filler. 1 / wavelength of
2, preferably 1/5 or less, titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate having a heat ray transmission (mainly infrared or far infrared transmission) of 1 μm or less, preferably 0.1 μm or less The light-transmitting substrate 171a may be formed by dispersing fine particles of a metal oxide such as a metal oxide in a resin binder. 1 in layer φ
Next, it is preferable that the average particle diameter including the secondary particles is 1 μm or less, preferably 0.1 μm or less, for preventing light scattering and reaching the heat ray absorbing layer 171b. Therefore, the light-transmitting substrate 171a has poor heat conductivity.

As the heat ray absorbing layer 171b, 90 to 100%, preferably 95 to 100%, of the heat rays emitted from the heat ray irradiating member 171g and substantially 100% of the heat rays transmitted through the translucent substrate 171a are applied to the heat ray absorbing layer 171b. Carbon black, graphite, iron black (Fe ₃ O ₄ ) and various ferrites and their ferrites and their compounds, copper oxide, cobalt oxide, Using a heat ray absorbing member mixed with a powder such as Fe ₂ O ₃ ), the heat ray absorbing member having a thickness of 10 to 200 μm, preferably 20 to 100 μm is baked or applied to the outside (outer peripheral surface) of the light-transmitting substrate 171a. And the like. The heat ray absorption rate of the heat ray absorption layer 171b is 9
If it is lower than about 0%, for example, about 20 to 80%, the heat ray leaks, and when the first heat ray fixing roller 17a as a heat ray fixing rotating member is used for monochrome image formation due to the leaked heat ray, filming occurs. When black toner adheres to the surface of the first heat ray fixing roller 17a at a specific position due to, for example, heat is generated from the adhering portion due to the leaked heat rays, and heat generated by heat ray absorption is further superimposed on that portion, resulting in the heat ray absorbing layer 171.
b is damaged. When used for color image formation,
Since the absorption efficiency of the color toner is generally low, and there is a difference in the absorption efficiency between the color toners, fixing failure occurs or fixing unevenness occurs. Therefore, the heat ray emitted from the heat ray irradiating member 171g and transmitted through the translucent substrate 171a is the first heat ray.
The heat ray absorbing layer 171b has a heat ray absorption rate of about 100%, which is about 100%, so that it is completely absorbed in the heat ray fixing roller 17a.
To 100%, preferably 95 to 100%. Also,
When the thickness of the heat ray absorbing layer 171b is less than 10 μm and thin, the heating rate by the absorption of the heat ray by the heat ray absorbing layer 171b is high, but the heat ray absorbing layer 171b by the local heating by the thin film.
If the thickness of the heat ray absorbing layer 171b exceeds 200 μm and becomes too thick, heat conduction becomes poor or the heat capacity becomes large and instantaneous heating becomes difficult to be achieved. The heat ray absorption rate of the heat ray absorption layer 171b is set to 90 to 100%, which is about 100%, preferably 95 to 100%, or the thickness of the heat ray absorption layer 171b is set to 10 to 200 μm, preferably 20 to 100 μm. Local heat generation in the absorption layer 171b is prevented, and uniform heat generation is performed. Further, the wavelength of the heat ray projected on the heat ray absorbing layer 171b is 0.1 to 20 μm, preferably 0.3 to 3 μm.
Therefore, an adjuster for hardness and thermal conductivity is added as a filler, but the average particle size including primary and secondary particles having a particle size of 、, preferably １ ／ or less of the wavelength of the heat ray is included. Is 1μ
m or less, preferably 0.1 μm or less, fine particles of a metal oxide such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate, etc., having a heat ray transmission property (mainly infrared or far infrared ray transmission property) of resin binder. 5 to 50% by weight dispersed in the heat ray absorbing layer 1
71b may be formed. In this way, the heat capacity of the heat ray absorbing layer 171b is reduced so that the temperature rises immediately, so that the temperature of the first heat ray fixing roller 17a as a heat ray fixing rotating member decreases, and fixing unevenness occurs. Prevent problems.

Further, a PFA (fluororesin) tube having a thickness of 30 to 100 μm is coated on the outer side (outer peripheral surface) of the heat ray absorbing layer 171 b separately from the heat ray absorbing layer 171 b in order to improve the releasability from the toner. Or fluorinated resin (PF
(A or PTFE) A release layer 171c coated with a paint of 20 to 30 μm is provided (separation type).

Further, as shown in cross section in FIG. 6B, carbon black, graphite, iron black (Fe ₃ O ₄ ), various ferrites and their compounds, copper oxide, cobalt oxide, red iron oxide (Fe ₂ O ₃ ), etc. Heat-absorbing member mixed with powder of PTFE, and a fluororesin (PFA or PT) that also serves as a binder and a release agent
FE) A paint is mixed and mixed, and the heat ray absorbing layer 171b and the release layer 171c described above with reference to FIG. To form a roll-shaped rotating member for heat ray fixing. In the same manner as described above, the integrated heat ray absorbing layer 1 is so formed that the heat rays emitted from the heat ray irradiating member 171g and transmitted through the translucent substrate 171a are completely absorbed.
The heat ray absorptivity of 71B is approximately 100%, which is 90 to 100.
%, Preferably 95 to 100%. When the heat ray absorptivity of the integrated heat ray absorbing layer 171B is lower than about 90%, for example, about 20 to 80%, the heat ray leaks, and the heat ray fixing rotary member is used for monochrome image formation due to the leaked heat ray. In the case, when the black toner adheres to the surface of the heat ray fixing rotating member at a specific position due to filming or the like, heat is generated from the adhering portion due to the leaked heat rays, and heat is further generated by heat ray absorption in that portion, and the integrated heat ray absorbing layer is generated. Damage 171B. Further, when used for forming a color image, the absorption efficiency of the color toner is generally low, and there is a difference in the absorption efficiency between the color toners, resulting in poor fixing or uneven fixing. Therefore, the heat ray absorption rate of the integrated heat ray absorbing layer 171B is about 100% so that the heat ray emitted from the heat ray irradiating member 171g and transmitted through the light transmitting base 171a is completely absorbed in the heat ray fixing rotating member. -10
0%, preferably 95 to 100%. In addition, local heat generation in the integrated heat ray absorbing layer 171B is also prevented, and uniform heat generation is performed. In addition, since the wavelength of the heat ray projected on the integrated heat ray absorbing layer 171B is 0.1 to 20 μm, and preferably 0.3 to 3 μm, a hardness or heat conductivity modifier is added as a filler. The diameter is 1 / the wavelength of the hot wire
2. Titanium oxide having an average particle diameter of 1 μm or less, preferably 0.1 μm or less including primary and secondary particles, preferably 1/5 or less, and having a heat ray transmission property (mainly infrared or far infrared ray transmission property). The integrated heat ray absorbing layer 171B may be formed by dispersing 5 to 50% by weight of fine particles of a metal oxide such as aluminum, zinc oxide, silicon oxide, magnesium oxide, and calcium carbonate in a resin binder.

According to FIG. 7, the heat ray absorbing layer 1 of the first heat ray fixing roller 17a as a rotating heat ray fixing rotating member is used.
It is preferable to generate heat inside the heat ray absorbing layer 171b by providing the above-described concentration distribution of the heat ray absorbing member in the heat ray absorbing layer 171b. As shown in the graph (A), the concentration distribution of the heat ray absorbing layer 171b is set such that the interface on the side of the transparent substrate 171a in contact is made low in concentration and is gradually inclined toward the outer peripheral surface side so as to be higher. The thickness is set so as to be 100% absorbed by the light-transmissive substrate 171a (at a position approximately 2/3 to 4/5 from the thickness of the heat ray absorbing layer 171b) so that the heat ray absorbing layer 171b is saturated. Accordingly, the heat generation distribution due to the absorption of the heat rays in the heat ray absorbing layer 171b has a maximum value near the center of the heat ray absorbing layer 171b as shown in the graph (b).
The heat ray absorbing layer 171b is formed in a parabolic shape having a minimum value near the interface and the outer peripheral surface. Thereby, heat generation due to absorption of heat rays at the interface is reduced, and damage to the adhesive layer and damage to the heat ray absorbing layer 171b at the interface are prevented. Further, the concentration distribution from the near side of the outer peripheral surface side (about ２ to ／ of the thickness t of the heat ray absorbing layer 171b from the transparent substrate 171a side) to the outer peripheral surface is saturated. For example, in the case where the integrated heat ray absorbing layer 171B is used, there is no influence even if the outer peripheral surface layer is shaved. Note that a saturated layer may be formed as shown by a dotted line. In short, if the absorption is sufficiently performed inside, the influence of the concentration on the outside disappears. There is no influence of shaving. Further, the concentration distribution is provided with the inclination, and the heat generation distribution can be adjusted by changing the inclination angle.

As shown in FIG. 8, the outer diameter φ of the cylindrical light-transmitting substrate 171a of the first heat-ray fixing roller 17a as a roll-shaped heat-ray fixing rotating member is 15 to 60.
mm, the thickness t is better in terms of strength and the thickness t is better in terms of heat capacity. However, due to the relationship between strength and heat capacity, the thickness t is outside Diameter φ
The relationship between the thickness and the thickness t is 0.05 ≦ t / φ ≦ 0.20, preferably 0.07 ≦ t / φ ≦ 0.14. When the outer diameter φ of the translucent substrate 171a is 40 mm, the thickness t of the translucent substrate 171a is 2 mm ≦ t ≦ 8 mm, preferably 2.8 mm ≦ t ≦ 5.6 mm. When t / φ is less than 0.05 in the translucent substrate 171a, the strength becomes insufficient, and when t / φ exceeds 0.20, the heat capacity increases and the heating of the first heat ray fixing roller 17a is prolonged. Further, depending on the material, a light-transmitting substrate may absorb about 1 to 20% of heat rays, and it is preferable that the substrate be thin as long as the strength can be maintained.

As described above, the fixing device 1 described with reference to FIG.
The use of No. 7 is strong against deformation at the fixing portion (nip portion) and enables a fixing device for quick start fixing by instantaneous heating. Instantaneous heat-fixing of a toner image at the time of quick-start of single-sided image formation on a frequently used surface becomes possible, and an energy saving effect is obtained.

FIGS. 9 and 1 show another example of the fixing device.
Explanation will be made using 0. FIG. 9 is an explanatory diagram showing the structure of a second example of the fixing device, and FIG. 10 is an enlarged cross-sectional configuration diagram of a second example of a roll-shaped rotating member for heat ray fixing.

As shown in FIG. 9, the fixing device 1 of the second example
Reference numeral 7A denotes an upper (front side) second heat ray fixing roller 17b serving as a roll-shaped heat ray fixing rotating member for fixing a toner image of a front side image (upper side image), and a back side image (lower side image). Lower side (back side) for fixing toner image of
Fixing roller 4 as a roll-shaped fixing rotating member
7b, the recording paper P is sandwiched by a nip portion T formed between the second heat ray fixing roller 17b and the second fixing roller 47b, and the toner on the recording paper P is applied by applying heat and pressure. Fix the image.

The second heat ray fixing roller 17b as a heat ray fixing rotating member for fixing the toner image of the front surface image is
Cylindrical translucent substrate 171a, and translucent substrate 171a
The elastic layer 171d and the heat ray absorbing layer 171
b and the release layer 171c are provided in this order.
For example, a soft roller having a heat ray irradiating member 171g, which is a heat ray irradiating means using a halogen lamp or a xenon lamp, is arranged inside 1a. Heat ray irradiation member 171
The heat ray emitted from g is absorbed by the heat ray absorbing layer 171b to form a roll-shaped heat ray fixing rotating member capable of instantaneous heating (second example of the instantaneous heating roll-shaped heat ray fixing rotating member). . A heat equalizing roller TA2 is provided outside the second heat ray fixing roller 17b serving as a roll-shaped heat ray fixing rotating member in contact with the second heat ray fixing roller 17b.

The second fixing roller 47b as a fixing rotating member for fixing the toner image of the back side image is made of, for example, an aluminum material, a steel material or the like having a Teflon coat applied to its outer peripheral surface by baking or coating. It is formed of a cylindrical metal pipe 472a which has been wound, and is configured as a hard roller in which a halogen heater 471c is disposed inside the metal pipe 472a. A nip portion T having a convex upper side is formed between the upper soft roller and the lower hard roller, and the toner image is fixed.

TS1 is the upper second heat ray fixing roller 17b
Is a temperature sensor using, for example, a thermistor for performing temperature control, and TS2 is a temperature sensor using, for example, a thermistor for performing temperature control, mounted on the lower second fixing roller 47b.

In the above, the second heat ray fixing roller 1 as a heat ray fixing rotating member formed as a soft roller
As the heat equalizing roller TA2 to be in contact with 7b, for example, metal powder having good thermal conductivity such as aluminum, iron, and stainless steel, or titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate, etc. A soft type (elastic) rubber roller mixed with metal oxide fine particles and having good thermal conductivity, or a rubber roller with a heat pipe inside is used. The second heat ray fixing roller 17b and the heat uniformizing roller T are formed as soft rollers and have good mutual contact between the second heat ray fixing roller 17b and the heat equalizing roller TA2, which are mutually elastic.
A surface of the second heat ray fixing roller 17b, which uses a light-transmissive substrate 171a having a low thermal conductivity, which will be described later, is used by the heat uniformizing roller TA2 in which heat transfer with A2 is performed well and the surface temperature is uniformly distributed. Temperature uniformity. Further, the temperature variation between the paper passing portion and the non-paper passing portion is made uniform by the difference in the size of the transfer material to be passed. Thus, the occurrence of uneven fixing of the toner image on the transfer material to be fixed is prevented.

The heat equalizing roller TA2 is a hard metal roller having good thermal conductivity, for example, using an aluminum material or a stainless steel material. And the temperature of the surface of the second heat ray fixing roller 17b is made uniform in the same manner as described above by using a hard type metal roller including a heat pipe in the heat equalizing roller TA2. Alternatively, the heat equalizing roller TA2 is brought into contact with the soft type second heat ray fixing roller 17b, and the mutual heat transfer is favorably performed, and the temperature of the surface of the second heat ray fixing roller 17b is equalized.

According to FIG. 10, the configuration of the second heat ray fixing roller 17b is such that, as shown in the cross section in FIG.
Pyrex glass, sapphire (Al ₂ O ₃ ), CaF ₂ that transmits heat rays such as infrared rays or far infrared rays from 1 g
Or a translucent resin using polyimide, polyamide, or the like. In addition, the light-transmitting substrate 171a
Since the wavelength of the heat ray passing through the wire is 0.1 to 20 μm, preferably 0.3 to 3 μm, an adjuster for hardness and thermal conductivity is added as a filler.
/ 2, preferably 1/5 or less, a titanium oxide having an average particle diameter of 1 μm or less, preferably 0.1 μm or less, including primary and secondary particles, and having a heat ray transmitting property (mainly infrared ray or far infrared ray transmitting property); The light-transmitting base 171a may be formed by dispersing fine particles of a metal oxide such as aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, and calcium carbonate in a resin binder. It is preferable that the average particle diameter including the primary and secondary particles is 1 μm or less, preferably 0.1 μm or less to prevent light scattering and reach the heat ray absorbing layer 171b. Therefore, the light-transmitting substrate 171a has poor heat conductivity.

The elastic layer 171d is formed of a rubber layer (base layer) that transmits heat rays (mainly infrared rays or far infrared rays) and is made of, for example, silicon rubber having a thickness of about 2 to 20 mm. For the elastic layer 171d, in order to cope with high speed, a method of improving thermal conductivity by blending a base rubber (silicone rubber) with a powder of a metal oxide such as silica, alumina or magnesium oxide as a filler is employed. Preferably, the rubber layer has a conductivity of 8.4 × 10 ^-1 W / (m ° C.) or more. Increasing the thermal conductivity generally tends to increase the rubber hardness, for example, typically 40 Hs
Is high up to near 60 Hs (JIS, A rubber hardness). Most of the elastic layer 171d of the heat ray fixing rotating member is occupied by the base layer, and the amount of compression during pressurization is determined by the rubber hardness of the base layer. Elastic layer 171d
The intermediate layer is coated with a fluorine-based rubber having a thickness of 20 to 300 μm as an oil-resistant layer to prevent oil swelling. As the silicon rubber of the top layer of the elastic layer 171d, HTV
(High temperature volcani
RTV (roomtem) with better releasability than zing)
quality volcanizing) and LTV
(Low temperature volcaniz
ing) is coated with a thickness similar to that of the intermediate layer. The wavelength of the heat ray passing through the elastic layer 171d is 0.1 to 20 μm.
m, preferably 0.3 to 3 μm, and includes primary and secondary particles having a particle diameter of 、, preferably １ ／ or less of the wavelength of the heat ray, as an agent for adjusting the hardness or thermal conductivity. Metal oxides such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate and the like having an average particle diameter of 1 μm or less, preferably 0.1 μm or less, and having a heat ray transmission property (mainly infrared or far infrared ray transmission property). The elastic layer 171d may be formed by dispersing fine particles of the above in a resin binder. Average particle size including primary and secondary particles is 1μ
m or less, preferably 0.1 μm or less is preferable for preventing light scattering and reaching the heat ray absorbing layer 171b.

As the heat ray absorbing layer 171b, 90 to 100% of the heat rays emitted from the heat ray irradiating member 171g and transmitted through the translucent substrate 171a and the elastic layer 171d are used.
Carbon black, graphite, iron black (Fe ₃ O _{4) is used} in the resin binder so that a heat ray absorbing layer 171b absorbs 100%, preferably 95% to 100%, of heat rays to form a heat ray fixing rotating member capable of instantaneous heating. ) And various ferrites and their compounds, copper oxide, cobalt oxide, red iron oxide (Fe
A heat ray absorbing member mixed with powder such as ₂ O ₃ )
The heat ray absorbing member having a thickness of 0 to 200 μm, preferably 20 to 100 μm is formed on the outer side (outer peripheral surface) of the elastic layer 171d by spraying or coating. The heat ray absorption rate in the heat ray absorption layer 171b is lower than about 90%, for example, 20 to 80.
%, The heat ray leaks, and when the second heat ray fixing roller 17b as the heat ray fixing rotating member is used for monochrome image formation due to the leaked heat ray, a specific position of the second heat ray fixing roller 17b by filming or the like. When black toner adheres to the surface of the, heat is generated from the adhered part due to the leaked heat rays,
Heat generation due to heat ray absorption occurs again at that portion, and the heat ray absorption layer 171b is damaged. When used for color image formation, the color toner absorption efficiency is generally low,
In addition, since there is a difference in absorption efficiency between the color toners, a fixing failure or a fixing unevenness occurs. Therefore, the heat ray absorption rate of the heat ray absorbing layer 171b is substantially 100%, which is 90 to 100%, so that the heat ray emitted from the heat ray irradiating member 171g and transmitted through the elastic layer 171d is completely absorbed in the second heat ray fixing roller 17b. , Preferably 95 to 100%. When the thickness of the heat ray absorbing layer 171b is less than 10 μm and thin, the heating rate due to the absorption of heat rays in the heat ray absorbing layer 171b is high, but the heat ray absorbing layer 171b is damaged by local heating by the thin film and the strength of the heat ray absorbing layer 171b may be insufficient. When the thickness of the heat ray absorbing layer 171b exceeds 200 μm and is too thick, poor heat conduction or large heat capacity makes instant heating difficult. The heat ray absorption rate of the heat ray absorption layer 171b is about 10
90% to 100%, preferably 95 to 100%
% Or the thickness of the heat ray absorbing layer 171b is 10 to 200%.
μm, preferably 20 to 100 μm,
Local heat generation in the heat ray absorbing layer 171b is prevented, and uniform heat generation is performed. Further, the wavelength of the heat ray projected on the heat ray absorbing layer 171b is 0.1 to 20 μm, preferably 0.3 to 20 μm.
３3 μm, an additive for hardness and thermal conductivity is added as a filler. Fine particles of a metal oxide such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate, etc., having a particle size of 1 μm or less, preferably 0.1 μm or less, having a heat ray transmission property (mainly infrared or far infrared ray transmission property). May be dispersed in a resin binder in an amount of 5 to 50% by weight to form the heat ray absorbing layer 171b. Since the heat capacity of the heat ray absorbing layer 171b is reduced so that the temperature rises immediately, the first heat ray rotating member for fixing the heat ray is used.
It is possible to prevent a problem that the temperature of the heat ray fixing roller 17a is lowered and the fixing unevenness occurs.

Further, a PFA (fluororesin) tube having a thickness of 30 to 100 μm is coated on the outer side (outer peripheral surface) of the heat ray absorbing layer 171b separately from the heat ray absorbing layer 171b in order to improve the releasability from the toner. Or fluorinated resin (PF
(A or PTFE) A release layer 171c coated with a paint of 20 to 30 μm is provided (separation type).

Further, as shown in the cross section in FIG.
A heat ray absorbing member mixed with powders such as carbon black, graphite, iron black (Fe ₃ O ₄ ), various ferrites and compounds thereof, copper oxide, cobalt oxide, and red iron (Fe ₂ O ₃ ); a binder and a release agent; Resin (PFA or P
TFE) paint is mixed, and the heat ray absorbing layer 171b and the release layer 171c described above with reference to FIG. Elastic layer 1 formed outside (outer peripheral surface) of 171a
It is formed outside (outer peripheral surface) of 71d to form a roll-shaped rotating member for fixing heat rays. In the same manner as described above, the heat ray absorptivity of the integrated heat ray absorbing layer 171B is about 100% so that the heat rays emitted from the heat ray irradiating member 171g and transmitted through the translucent substrate 171a and the elastic layer 171d are completely absorbed. 90 to 100%, preferably 95 to 100%. The heat ray absorption rate of the integrated heat ray absorbing layer 171B is 90%.
If it is lower than about 20% to 80%, for example, the heat ray leaks, and when the heat ray fixing rotary member is used for monochrome image formation due to the leaked heat ray, a specific position of the heat ray fixing rotary member is determined by filming or the like. When the black toner adheres to the surface, heat is generated from the adhering portion due to the leaked heat rays, and the heat generated by the absorption of the heat rays is further superimposed at that portion, thereby damaging the integrated heat ray absorbing layer 171B. When used for color image formation, the color toner absorption efficiency is generally low,
In addition, since there is a difference in absorption efficiency between the color toners, a fixing failure or a fixing unevenness occurs. Accordingly, the heat ray absorption rate of the integrated heat ray absorbing layer 171B is set to approximately 100% so that the heat rays emitted from the heat ray irradiating member 171g and transmitted through the translucent substrate 171a are completely absorbed in the heat ray fixing rotating member.
90 to 100%, preferably 95 to 100%. In addition, local heat generation in the integrated heat ray absorbing layer 171B is also prevented, and uniform heat generation is performed. The wavelength of the heat ray projected on the integrated heat ray absorbing layer 171B is 0.1 to 2
Since the thickness is 0 μm, preferably 0.3 to 3 μm, an adjuster for hardness and thermal conductivity is added as a filler, but the particle size is ２, preferably １ ／ or less of the wavelength of the heat ray.
Next, titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide having an average particle diameter of 1 μm or less, preferably 0.1 μm or less, including secondary particles, having a heat ray transmission property (mainly infrared or far infrared ray transmission property). The integrated heat ray absorbing layer 171B may be formed by dispersing fine particles of a metal oxide such as calcium carbonate in a resin binder.

Further, as shown in the cross section in FIG.
A heat ray absorbing member mixed with powders such as carbon black, graphite, iron black (Fe ₃ O ₄ ), various ferrites and compounds thereof, copper oxide, cobalt oxide, and red iron (Fe ₂ O ₃ ); a binder and a release agent; Resin (PFA or P
TFE) paint is further mixed with silicone rubber and blended, and the elastic layer 171d and the integral heat ray absorbing layer 171B described above with reference to FIG. 10B are integrated to form an integral elastic layer 171D also serving as a heat ray absorbing layer. A roll-shaped heat ray fixing rotating member is formed outside (outer peripheral surface) of the light transmitting substrate 171a. In the same manner as described above, the integrated elastic layer 171D also serving as a heat ray absorbing layer is provided so that heat rays emitted from the heat ray irradiating member 171g and transmitted through the translucent substrate 171a are completely absorbed in the heat ray fixing rotating member. The heat ray absorptivity is set to 90 to 100%, which is approximately 100%, preferably 95 to 100%. When the heat ray absorption rate of the integrated elastic layer 171D is lower than about 90%, for example, about 20 to 80%, the heat ray leaks, and the heat ray fixing rotary member is used for monochrome image formation due to the leaked heat ray. When the black toner adheres to the surface of the heat ray fixing rotating member at a specific position due to filming or the like, heat is generated from the adhering portion due to the leaked heat rays, and heat generated by heat ray absorption is further superimposed on that portion, causing the integrated elastic layer 171D to be removed. fall into disrepair. Further, when used for forming a color image, the absorption efficiency of the color toner is generally low, and there is a difference in the absorption efficiency between the color toners, resulting in poor fixing or uneven fixing. Therefore, the heat ray irradiation member 171
g, the heat ray absorption of the integrated elastic layer 171D is set to 90-100%, which is about 100%, and preferably 95-100%, so that the heat rays transmitted through the translucent substrate 171a are completely absorbed. In addition, local heat generation in the integrated elastic layer 171D is also prevented, and uniform heat generation is performed. In addition, since the wavelength of the heat ray projected on the integrated elastic layer 171D is 0.1 to 20 μm, preferably 0.3 to 3 μm, a hardness or thermal conductivity modifier is added as a filler. Has an average particle diameter of 1 μm or less including primary and secondary particles having a wavelength of 熱, preferably １ ／ or less, of the heat ray,
Preferably, fine particles of metal oxides such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate and the like having a heat ray transmission of preferably 0.1 μm or less (mainly transmission of infrared rays or far infrared rays) are dispersed in a resin binder. Alternatively, the integrated elastic layer 171D may be formed.

The heat ray absorbing layer 17 of the second heat ray fixing roller 17b as a roll-shaped heat ray fixing rotating member described above.
1b, the integrated heat ray absorbing layer 171B and the integrated elastic layer 171
Also in D, it is preferable to generate heat inside the heat ray absorbing layer 171b by providing the concentration distribution of the heat ray absorbing member described above with reference to FIG. Thereby, heat generation due to absorption of heat rays at the interface with each light-transmitting substrate 171a is reduced, and the damage of the adhesive layer and the heat ray absorbing layer 171b at the interface are reduced.
And the heat ray absorbing layer 171B and the elastic layer 171D are prevented from being damaged. In addition, just before the outer peripheral surface side of the integrated heat ray absorbing layer 171B and the integrated elastic layer 171D (2/3 from the side of the transparent substrate 171a with respect to the thickness t of the integrated heat ray absorbing layer 171B and the integrated elastic layer 171D). (About 4/5 position) so as to obtain a concentration that absorbs 100% so as to saturate, and when the integrated heat ray absorbing layer 171B or the integrated elastic layer 171D is used, the outer peripheral surface layer is shaved. Also have no effect. In the case of the separation type, it is not necessary to form a saturated layer. Further, the concentration distribution is provided with the inclination, and the heat generation distribution can be adjusted by changing the inclination angle. Also, the outer diameter φ
The relationship between the outer diameter φ and the thickness t of the cylindrical light-transmitting substrate 171a for which a thickness of 15 to 60 mm is used is the same as described above with reference to FIG. And preferably 0.07 ≦ t / φ ≦ 0.14. When the outer diameter φ of the translucent substrate 171a is 40 mm, the thickness t of the translucent substrate 171a is 2 mm ≦ t ≦ 8 mm, preferably 2.8 mm ≦ t ≦ 5.6 mm. If t / φ is less than 0.05 in the translucent substrate 171a, the strength will be insufficient. If t / φ exceeds 0.20, the heat capacity will increase and the heating of the second heat ray fixing roller 17b will be prolonged. Further, depending on the material, a light-transmitting substrate may absorb about 1 to 20% of heat rays, and it is preferable that the substrate be thin as long as the strength can be maintained.

As described above, the fixing device 1 described with reference to FIG.
By using 7A, the fixing device (nip portion) is resistant to deformation, and a fixing device for quick start fixing by instantaneous heating becomes possible. In particular, by using the image forming device described with reference to FIG. Instantaneous heat-fixing of the toner image at the time of frequently forming a one-sided image on the front surface can be performed instantaneously, and an energy saving effect can be obtained.

The fixing device for double-sided fixing using the roll-shaped rotating member for hot-wire fixing for instant heating described in FIG. 9 or FIG. 5 and the temperature control thereof will be described with reference to FIG. 11 to FIG. explain. FIG. 11 shows a second example of a double-sided fixing roll using the instantaneous heating roll-shaped hot-wire fixing rotary member of the first example and the instant example roll-shaped hot-wire fixing rotary member of the second example. FIG. 12 is a diagram showing a fixing device of a third example, and FIG. 12 is a diagram showing a fixing device of a fourth example for double-sided fixing using a roll-shaped rotating member for hot-wire fixing for instantaneous heating of the second example as a pair. FIG. 13 is a temperature control timing chart at the time of double-sided image formation using the fixing device of the third example or the fourth example, and FIG. 14 is a timing chart of the third example or the fourth example. FIG. 15 is a temperature control timing chart when forming a single-sided image on the front surface using the fixing device. FIG. 15 is a temperature control timing chart when forming a single-sided image on the back surface using the fixing device of the third example or the fourth example. is there.

As shown in FIG. 11, a fixing device 17B of a third example as an example of a fixing device using a roll-shaped rotating member for hot-wire fixing for instantaneous heating for double-sided fixing, as shown in FIG. The first hot-wire fixing roller 17a (roll-like hot wire for instantaneous heating) similar to the first hot-wire fixing roller 17a described in FIG. 5 as an upper (front-side) hot-wire fixing rotary member for fixing the toner image of FIG. FIG. 9 illustrates a first example of a fixing rotating member) and a lower (back side) roll-shaped heat ray fixing rotating member for fixing a toner image of a back side image (lower side image). Second heat ray fixing roller 17b similar to the above (second example of roll-shaped heat ray fixing rotating member for instantaneous heating)
The recording paper P is sandwiched by a nip portion T formed between the upper and lower heat ray fixing rotating members, and heat and pressure are applied to fix the toner image on the recording paper P.
A heat equalizing roller TA1 is provided outside the first hot-wire fixing roller 17a as an upper roll-shaped hot-wire fixing rotating member in contact with the first hot-wire fixing roller 17a, and the lower roll-shaped hot wire is provided. Outside the second heat ray fixing roller 17b as a fixing rotating member, a heat uniformizing roller TA2 is provided in contact with the second heat ray fixing roller 17b.

The first heat ray fixing roller 17a used as an upper heat ray fixing rotating member for fixing the toner image of the front surface image includes a cylindrical light transmitting base 171a and an outer side (outer periphery) of the light transmitting base 171a. A hard roller having a heat ray absorbing layer 171b and a release layer 171c provided in this order on the surface, and a heat ray irradiating member 171g as a heat ray irradiating means using, for example, a halogen lamp or a xenon lamp is provided inside the translucent substrate 171a. Be composed. The heat ray emitted from the heat ray irradiating member 171g is absorbed by the heat ray absorbing layer 171b to form a roll-shaped heat ray fixing rotating member capable of instantaneous heating (the first heat-fixing roll-shaped rotating member for instant heating). Example). The above-described heat-fixing rotary member in the form of a roll for instant heating using the integrated heat-ray absorbing layer 171B is also used as the upper heat-fixing rotary member.

As the heat uniformizing roller TA1 which is in contact with the first heat ray fixing roller 17a as a heat ray fixing rotating member formed as a hard roller, a metal such as aluminum, iron, stainless steel or the like having good heat conductivity is used. A soft (elastic) rubber roller with good thermal conductivity mixed with powder or fine particles of metal oxide such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate, or the inside of the rubber roller Used a heat pipe. Heat uniformizing roller TA
Due to the good contact between the first heat ray fixing roller 17a and the first heat ray fixing roller 17a due to the elasticity of 1, the heat transfer between the first heat ray fixing roller 17a and the heat equalizing roller TA1 is performed well, and the heat uniformity in which the surface temperature is uniformly distributed. The temperature unevenness on the surface of the first heat ray fixing roller 17a using the translucent substrate 171a having low thermal conductivity is made uniform by the forming roller TA1. Further, the temperature variation between the paper passing portion and the non-paper passing portion is made uniform by the difference in the size of the transfer material to be passed. Thus, the occurrence of uneven fixing of the toner image on the transfer material to be fixed is prevented.

The heat equalizing roller TA1 is a hard type metal roller using, for example, an aluminum material or a stainless steel material having a good thermal conductivity. And the temperature of the surface of the first heat ray fixing roller 17a can be made uniform in the same manner as described above by using a hard type metal roller including a heat pipe in the heat equalizing roller TA1. However, since both the first heat ray fixing roller 17a and the heat equalizing roller TA1 are of a hard type, the contact between them becomes a line contact or a discontinuous line contact, and the mutual heat transfer is not performed well. Not very good.

The second heat ray fixing roller 17b used as a lower heat ray fixing rotating member for fixing the toner image of the back side image has a cylindrical light-transmitting base 171a and an outer side of the light-transmitting base 171a. An elastic layer 171d, a heat ray absorbing layer 171b, and a release layer 171c are provided in this order on the outer peripheral surface), and a heat ray irradiating member 17 as a heat ray irradiating means using, for example, a halogen lamp or a xenon lamp is provided inside the translucent substrate 171a.
It is configured as a soft roller in which 1 g is disposed. The heat ray emitted from the heat ray irradiating member 171g is a heat ray absorbing layer 171b.
Thus, a rotating member for hot-wire fixing capable of being instantaneously heated and absorbed is formed (second example of a rotating member for hot-wire fixing for instantaneous heating). The above-described heat-fixing rotary member in the form of a roll for instant heating using the integrated heat-ray absorbing layer 171B and the integrated elastic layer 171D is also used as the lower heat-ray fixing rotary member.

As the heat equalizing roller TA2 which is in contact with the second heat ray fixing roller 17b as a heat ray fixing rotating member formed as a soft roller, a metal such as aluminum, iron, stainless steel or the like having good heat conductivity is used. A soft (elastic) rubber roller with good thermal conductivity mixed with powder or fine particles of metal oxide such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate, or the inside of the rubber roller Used a heat pipe. Second heat ray fixing roller 17 formed as a soft roller and having mutual elasticity
The heat transfer between the second heat ray fixing roller 17b and the heat equalizing roller TA2 is favorably performed by the good contact between the second heat ray fixing roller 17b and the heat uniformizing roller TA2, and the heat uniformizing roller TA2 having a uniform surface temperature distribution. Translucent substrate 17 having poor thermal conductivity
The temperature unevenness on the surface of the second heat ray fixing roller 17b using 1a is made uniform. Further, the temperature variation between the paper passing portion and the non-paper passing portion is made uniform by the difference in the size of the transfer material to be passed. Thus, the occurrence of uneven fixing of the toner image on the transfer material to be fixed is prevented.

The heat equalizing roller TA2 is a hard type metal roller having good thermal conductivity, for example, using an aluminum material or a stainless steel material. And the temperature of the surface of the second heat ray fixing roller 17b is made uniform in the same manner as described above by using a hard type metal roller including a heat pipe in the heat equalizing roller TA2. Alternatively, the heat equalizing roller TA2 is brought into contact with the soft type second heat ray fixing roller 17b, and the mutual heat transfer is favorably performed, and the temperature of the surface of the second heat ray fixing roller 17b is equalized.

A nip portion T having a convex lower side is formed between the heat ray fixing rotating member of the upper hard roller and the heat ray fixing rotating member of the lower soft roller, and the toner image is fixed. TS1 is a temperature sensor using, for example, a thermistor for controlling the temperature attached to the upper first heat ray fixing roller 17a, and TS2 is for controlling the temperature attached to the lower second heat ray fixing roller 17b. For example, a temperature sensor using a thermistor.

In the above, by providing the heat equalizing rollers TA1 and TA2 on the upper and lower heat ray fixing rotating members,
The temperature of each heat ray fixing rotating member is made more uniform.

A fixing device 17C of a fourth example as another example of a fixing device using a roll-shaped rotating member for hot-wire fixing for instantaneous heating for double-sided fixing, as shown in FIG.
An upper (front side) roll-shaped heat ray fixing rotating member for fixing a toner image of a front side image (upper side image) or a lower side (fixing of a back side image (lower side image) toner image) The second heat ray fixing roller 17b (the second example of the instantaneous roll heat ray fixing rotary member for instantaneous heating) is the same as the roll heat ray fixing rotating member on the back side (FIG. 9). The recording paper P is sandwiched by a nip portion T formed between the upper and lower heat ray fixing rotating members,
The toner image on the recording paper P is fixed by applying heat and pressure. Outside the second hot-wire fixing roller 17b as an upper and lower roll-shaped hot-wire fixing rotating member, a heat equalizing roller TA2 is provided in contact with each of the second hot-wire fixing rollers 17b.

A second heat ray fixing rotating member for fixing the toner image of the front side image or a lower heat ray fixing rotating member for fixing the toner image of the rear side image.
The heat ray fixing roller 17b is formed of a cylindrical translucent substrate 171a.
And an elastic layer 1 on the outer side (outer peripheral surface) of the light-transmitting substrate 171a.
71d, a heat ray absorbing layer 171b, and a release layer 171c are provided in this order, and are configured as a soft roller in which a heat ray irradiating member 171g which is a heat ray irradiating means using, for example, a halogen lamp or a xenon lamp is disposed inside a light transmitting base 171a. Is done. A heat ray emitted from the heat ray irradiating member 171g is absorbed by the heat ray absorbing layer 171b to form a roll-shaped heat ray fixing rotating member capable of instantaneous heating (second of the instantaneous heating roll-shaped heat ray fixing rotating member). Example). The above-described heat-fixing rotary member in the form of a roll for instant heating using the integrated heat-ray absorbing layer 171B and the integrated elastic layer 171D is also used as the upper or lower heat-ray fixing rotary member. A flat nip portion T is formed between the heat ray fixing rotating members of the upper and lower soft rollers, and the toner image is fixed.

The heat uniformizing roller TA2 which is in contact with the upper and lower heat ray fixing rollers 17b as the upper and lower heat ray fixing rotating members formed as soft rollers, for example, aluminum, iron, stainless steel, etc. having good heat conductivity. Or a soft (elastic) rubber roller with good thermal conductivity mixed with fine particles of metal oxide such as titanium oxide, aluminum oxide, zinc oxide, silicon oxide, magnesium oxide, calcium carbonate, etc. A rubber roller containing a heat pipe is used. The second heat ray fixing roller 17b and the heat uniformizing roller T are formed as soft rollers and have good mutual contact between the second heat ray fixing roller 17b and the heat equalizing roller TA2, which are mutually elastic.
A second heat ray fixing roller 1 using a light-transmissive substrate 171a having a low thermal conductivity is formed by the heat equalizing roller TA2 in which heat transfer with A2 is performed well and the surface temperature is uniformly distributed.
The temperature unevenness on the surface of 7b is made uniform. Further, the temperature variation between the paper passing portion and the non-paper passing portion is made uniform by the difference in the size of the transfer material to be passed. Thus, the occurrence of uneven fixing of the toner image on the transfer material to be fixed is prevented.

The heat equalizing roller TA2 is a hard metal roller having good thermal conductivity, for example, made of aluminum, stainless steel, or the like. And the temperature of the surface of the second heat ray fixing roller 17b is made uniform in the same manner as described above by using a hard type metal roller including a heat pipe in the heat equalizing roller TA2. Alternatively, the heat equalizing roller TA2 is brought into contact with the soft type second heat ray fixing roller 17b, and the mutual heat transfer is performed well, and the temperature of the surface of the second heat ray fixing roller 17b is equalized.

In the above, by providing the heat equalizing roller TA2 to each of the upper and lower heat ray fixing rotating members,
The temperature of each heat ray fixing rotating member is made more uniform.

TS1 is an upper second heat ray fixing roller 17b.
Is a temperature sensor using, for example, a thermistor for performing temperature control, and TS2 is a temperature sensor using, for example, a thermistor for performing temperature control, which is mounted on the lower second heat ray fixing roller 17b. .

The fixing device 17B shown in FIG. 11 or FIG.
Alternatively, fixing temperature control when applying the fixing device 17C to the image forming apparatus for forming a double-sided image in FIG. 1 will be described below.

As shown in FIG. 13, when forming a double-sided image, the recording sheet P passing through the fixing device 17B or the fixing device 17C in response to the image formation on the front and back sides by the photosensitive drum 10 has a single-sided image on the front surface. Unlike the continuous printing by forming, the printing is performed intermittently every other sheet. However, an upper roll-shaped heat ray fixing rotating member for fixing the toner image of the surface image (the first heat ray fixing roller 17a in the case of the fixing device 17B). The second heat ray fixing roller 1 in the case of the fixing device 17C.
7b) The heating ray irradiating member 171g serving as the upper heating ray irradiating means is heated in an on state in synchronization with the passage timing of the recording paper P, and the fixing temperature set value T during the image forming pause and the proper fixing temperature during the image forming are heated. The temperature control of the upper heat ray fixing rotary member at an alternate level with the set value T2 is performed.

Similarly, the lower roll-shaped heat ray fixing rotating member for fixing the toner image on the back side image (in both the fixing device 17B and the fixing device 17C, the second heat ray fixing roller). 17b) a heat ray irradiating member 171 as a heat ray irradiating means in accordance with the passage timing of the recording paper P
g is turned on, and the temperature control of the lower heat ray fixing rotating member at the level of the fixing temperature set value T during the image forming pause and the appropriate fixing temperature set value T2 during the image forming is performed. Will be At this time, since the formation of the double-sided image is performed intermittently every other sheet, the non-passing time of the recording paper P is long, so that the temperature control and the temperature can be made uniform and the heat capacity is small. The double-sided image can also be fixed by the heat ray fixing rotating member.

The temperature control is performed by fixing temperature setting values T, T1, T2 stored in advance in the ROM and temperature sensors TS1, T2.
The detection is performed through the control unit via the comparison circuit by the detection in S2 (see FIG. 4).

In FIG. 13, the temperature control of the upper and lower heat ray fixing rotary members is performed in a region sandwiching the front and rear ends of the recording paper P. However, when the linear velocity is high, the temperature control timing is set earlier. It is necessary to always set T1 and T2 during the printing operation.

As shown in FIG. 14, when forming a single-sided image on the front surface, the recording paper P passing through the fixing device 17B or 17C for forming the image on the front surface by the photosensitive drum 10 is used.
Is different from the continuous printing in the double-sided image formation or the image formation on the back side of only one side, and is continuously performed in accordance with the image formation on the continuous front side by the photosensitive drum 10, but the toner image of the front side image is formed. The upper roll-shaped rotating member for heat ray fixing (first heat ray fixing roller 17a in the case of the fixing device 17B, second heat ray fixing roller 17b in the case of the fixing device 17C) for fixing the recording paper P is used for fixing. At the same time, the heat ray irradiating member 171g, which is the upper heat ray irradiating means, is heated in the on state, and the upper side of the alternate level of the fixing temperature set value T during the image forming pause and the proper fixing temperature set value T1 during the image forming is changed. The temperature of the heat ray fixing rotary member is controlled. During copying by single-sided image formation on the front surface, the heat ray irradiating member 171g is turned on before the recording paper P passes.
Heating is performed as a state, and heating temperature control of the upper heat ray fixing rotating member is performed so as to maintain an appropriate fixing temperature set value T1 during image formation.

On the other hand, the lower roll-shaped rotatable member for fixing heat rays (in the case of the fixing device 17B, the fixing device 17C
In both cases, the second heat ray fixing roller 17b) does not perform heating control during copying by forming a single-sided image on the front surface, or the fixing temperature setting value T during image formation suspension.
, The temperature of the lower heat ray fixing rotary member is controlled.

The temperature control is performed through a control unit via a comparison circuit based on fixing temperature set values T and T1 stored in advance in a ROM and detection by temperature sensors TS1 and TS2 (see FIG. 4).

In FIG. 14, the temperature control of the upper heat ray fixing rotating member is performed in a region sandwiching the leading and trailing ends of the recording paper P, but when the linear velocity is high, the temperature control timing is set earlier. It is necessary to always set T1 during the printing operation.

As shown in FIG. 15, when forming the one-sided image on the back side, the conveyance timing of the recording paper P passing through the fixing device 17B or the fixing device 17C in response to the image formation on the back side by the intermediate transfer belt 14a is as follows. Unlike continuous printing by forming a single-sided image on the front side, the printing is performed intermittently every other sheet. However, a lower roll-shaped heat ray fixing rotating member for fixing the toner image of the back side image (also in the case of the fixing device 17B,
Also in the case of the fixing device 17C, the second heat ray fixing roller 17
In b), the heat ray irradiating member 171g, which is the lower heat ray irradiating means, is heated to the ON state in synchronization with the passage timing of the recording paper P, and the fixing temperature set value T during the image forming pause and the proper fixing during the image forming. The temperature control of the lower heat ray fixing rotating member at an alternate level with the temperature set value T2 is performed.
During the copying by the one-sided image formation on the back side, the heating ray irradiating member 171g is turned on and heated before passing the recording paper P, and the lower heating ray fixing rotation is maintained so as to maintain the proper fixing temperature set value T2 during the image formation. The heating temperature of the member is controlled.

On the other hand, the upper roll-shaped rotatable member for fixing heat rays (the first heat ray fixing roller 17a in the case of the fixing device 17B, the second heat ray fixing roller 17b in the case of the fixing device 17C) has a single-sided back surface. During the copying by the image formation, the heating control is not performed, or the temperature of the lower heat ray fixing rotating member is controlled so as to maintain the fixing temperature set value T during the pause of the image formation.

As shown by the dashed line in FIG. 15, the upper heat ray fixing rotating member turns off the heat ray irradiating member 171g before passing the recording paper P during copying by single-sided image formation on the back side.
More preferably, heating is performed so as to maintain an appropriate fixing temperature set value T1 during image formation as the n state, and the tip of the nip portion T is overheated by heating the upper heat ray fixing rotating member to the on state, thereby recording. When the leading edge of the paper P is added to the nip portion, the toner image is not disturbed, and the toner image of the single-sided image on only the back surface is fixed favorably.

The temperature control is performed by setting the fixing temperature set values T, T2, (T1) stored in advance in the ROM and the temperature sensor TS.
1, through the control unit via the comparison circuit by the detection by TS2 (see FIG. 4).

In FIG. 15, the temperature control of the lower heat ray fixing rotary member and the upper heat ray fixing rotary member is performed in an area sandwiching the front and rear ends of the recording paper P. It is necessary to set the timing earlier, and to always set T1 and T2 during the printing operation.

According to FIGS. 13 to 15 described above, when forming a single-sided image on the front surface, forming a single-sided image on the back surface, or forming a double-sided image, the fixing of the toner image has a small heat capacity and can be performed quickly and quickly. The fixing is performed by the roll-shaped rotating member for heat ray fixing, so that good fixing can be performed without providing a warm-up time. In particular, since image formation on both sides or image formation on the back side of only one side is performed intermittently every other sheet, the fixing of the toner image on the back side has a lower heat ray fixing rotating member having a smaller heat capacity than a conventional heat fixing roller. Accordingly, the heat capacity is sufficient, and the fixing of the rear surface image by the lower heat ray fixing rotating member can be performed.

The image forming apparatus is set so that temperature control is automatically performed in the state of double-sided image formation at the time of initial operation when the power switch is turned on, or when the mode is changed from the pause mode to the print operation mode. Further, it is also possible to control the heating control of the upper and lower heat ray fixing rotating members to be turned off when the unused time elapses a predetermined time.

With the configuration described above, different energy consumption is performed when forming a single-sided image only on the front surface, when forming a single-sided image only on the back surface, or when forming a double-sided image.
Compared to conventional fixing devices that use heating elements for the upper and lower rollers, proper energy consumption is performed during single-sided image formation and double-sided image formation, respectively, so that both consume less energy and heat is generated by the conventional upper and lower rollers. In addition to a fixing device using a body or a film fixing device using a ceramic heater, a high nip width in the fixing area can be obtained and high fixing performance can be obtained. An image forming apparatus is provided.

As described above, by using the fixing device 17B or the fixing device 17C described with reference to FIG. 11 or FIG. 12, the fixing device (nip portion) is resistant to deformation and the fixing device for quick start fixing by instantaneous heating However, as described above, the use of the toner in the image forming apparatus described with reference to FIG. Can be

[0120]

According to the first to sixth aspects, at least one of the roll-shaped rotatable member for heat ray fixing and the heat equalizing roller is made of an elastic member, and is made uniform with the rotatable member for heat ray fixing. The heat transfer with the roller is performed well, the temperature of the hot-wire fixing rotary member is made uniform, and the temperature fluctuation and temperature drop of the hot-wire fixing rotary member are prevented. A fixing device using a heat ray for quick quick start fixing is provided.

According to the seventh to twelfth aspects, at least one of the roll-shaped rotating member for heat ray fixing and the heat equalizing roller is constituted by a member having elasticity. Heat transfer is performed well, the temperature of the heat ray fixing rotating member is made uniform, and the temperature fluctuation and temperature drop of the heat ray fixing rotating member are prevented to prevent the occurrence of fixing unevenness. There is provided an image forming apparatus capable of quick start fixation which is possible or has a short heating time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus showing an embodiment of a fixing device and an image forming apparatus using the fixing device according to the present invention.

FIG. 2 is a diagram illustrating a toner image forming state in the image forming apparatus of FIG. 1;

FIG. 3 is a diagram illustrating an example of a document image reading unit.

FIG. 4 is a block diagram of a control circuit of the image forming apparatus.

FIG. 5 is an explanatory diagram illustrating a structure of a first example of a fixing device.

FIG. 6 is an enlarged cross-sectional configuration diagram of a first example of a roll-shaped rotating member for heat ray fixing.

FIG. 7 is a diagram showing a concentration distribution of a heat ray absorbing layer of a roll-shaped heat ray fixing rotating member.

FIG. 8 is a diagram showing an outer diameter and a thickness of a light-transmitting substrate of a roll-shaped rotating member for fixing heat rays.

FIG. 9 is an explanatory diagram illustrating a structure of a second example of the fixing device.

FIG. 10 is an enlarged cross-sectional configuration diagram of a second example of a roll-shaped rotating member for heat ray fixing.

FIG. 11 shows a second example of a double-sided fixing device using a pair of the instantaneous heating roll-shaped hot-wire fixing rotary member for instantaneous heating and the second example of instantaneous heating roll-shaped hot-wire fixing rotary member. FIG. 11 is a diagram illustrating a fixing device according to a third example.

FIG. 12 is a diagram showing a fourth example of a fixing device for double-sided fixing using a roll-shaped hot-wire fixing rotating member for instantaneous heating of the second example as a pair.

FIG. 13 is a temperature control timing chart during double-sided image formation using the fixing device of the third example or the fourth example.

FIG. 14 is a temperature control timing chart when a single-sided image is formed on the front surface using the fixing device of the third example or the fourth example.

FIG. 15 is a temperature control timing chart when a single-sided image is formed on the back surface using the fixing device of the third example or the fourth example.

[Explanation of symbols]

 Reference Signs List 10 photoconductor drum 11 scorotron charger 12 exposure optical system 13 developing device 14a intermediate transfer belt 14c transfer device 14g back transfer device 17, 17A, 17B, 17C fixing device 17a first heat ray fixing roller 17b second heat ray fixing roller 171a Base 171B Integrated heat ray absorbing layer 171b Heat ray absorbing layer 171c Release layer 171D Integrated elastic layer 171d Elastic layer 171g Heat ray irradiating member P Recording paper TA1, TA2 Heat uniformizing roller

Claims (12)

[Claims] 1. A fixing device for fixing a toner image on a transfer material to the transfer material by applying heat and pressure, comprising: a cylindrical light-transmitting base in which a heat ray irradiating means for emitting heat rays is arranged; A heat ray absorbing layer is provided outside the translucent substrate to form a roll-shaped heat ray fixing rotating member, and an elastic heat equalizing roller having elasticity is provided in contact with the heat ray fixing rotating member. Fixing device. 2. The fixing device according to claim 1, wherein the heat equalizing roller has a heat pipe. 3. A fixing device for fixing a toner image on a transfer material to the transfer material by applying heat and pressure, comprising: a cylindrical light-transmitting base in which a heat ray irradiating means for emitting heat rays is arranged; A heat ray absorbing layer and an elastic layer are provided on the outside of the translucent substrate to form a roll-shaped heat ray fixing rotating member, and a heat uniforming roller is provided in contact with the heat ray fixing rotating member. Fixing device. 4. The fixing device according to claim 3, wherein the heat equalizing roller has elasticity. 5. The fixing device according to claim 3, wherein the heat equalizing roller is a hard roller. 6. The fixing device according to claim 3, wherein the heat equalizing roller is a heat pipe. 7. An image forming apparatus for forming a toner image on an image forming body, transferring the toner image onto a transfer material, and fixing the toner image on the transfer material by applying heat and pressure. A cylindrical light-transmissive substrate on which a heat-ray irradiating means for emitting heat rays is disposed; and a heat-ray absorbing layer provided outside the light-transmissive substrate to form a roll-shaped rotating member for fixing heat rays and heat having elasticity. An image forming apparatus, comprising: a fixing device provided with a uniforming roller in contact with the rotating member for fixing heat rays, wherein heating control is performed in accordance with the passage of the transfer material. 8. The image forming apparatus according to claim 7, wherein the heat equalizing roller has a heat pipe. 9. An image forming apparatus for forming a toner image on an image forming body, transferring the toner image onto a transfer material, and fixing the toner image on the transfer material by applying heat and pressure. A cylindrical light-transmissive substrate on which a heat-ray irradiating means for emitting heat rays is disposed; and a heat-ray absorbing layer and an elastic layer provided outside the light-transmissive substrate to form a roll-shaped rotating member for fixing heat rays. An image forming apparatus, further comprising a fixing device for disposing a heat uniformizing roller in contact with the heat ray fixing rotating member, and performing heating control in accordance with the passage of the transfer material. 10. The image forming apparatus according to claim 9, wherein the heat equalizing roller has elasticity. 11. The image forming apparatus according to claim 9, wherein the heat equalizing roller is a hard roller. 12. The image forming apparatus according to claim 9, wherein the heat equalizing roller is a heat pipe.