JP2001125409A - Fixing method, fixing device and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing device by which the damage of a fixing roller is prevented, a service life is prolonged, stable fixing performance can be realized for a long time, power saving performed by the improvement of the heating efficiency of a heating source can be attained, and an image forming device provided with the same. SOLUTION: As to this fixing device heating and fixing a toner image formed on a transfer material surface by making a transfer material P pass through a press-contacting position between the fixing roller 71 driving and rotating and a pressuring roller 72 brought into press-contact with the roller 71 and rotating ; the roller 71 is constituted of a translucent base body 71a inside of which the heating source 73 is arranged, which is hollow cylindrical shape and which has translucency, and a flexible driving and transmitting member 79 connecting the inside peripheral surface of a driving member 78 connected to a driving source and the outside peripheral surface of the one end part of the roller 71 is arranged on the one end part of the roller 71.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device used in an image forming apparatus such as a copying machine, a printer, a facsimile, and a multifunction machine having these functions, and an image forming apparatus provided with the fixing device.

[0002]

2. Description of the Related Art Conventionally, a fixing device used in an electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile, and a multifunction machine having these functions includes a fixing roller maintained at a predetermined temperature, an elastic roller, A heat roller fixing method, in which a sheet having an unfixed toner image formed thereon is heated while being pinched and conveyed by a pressure roller having a layer and pressed against the fixing roller, from a low-speed machine to a high-speed machine, from a monochrome machine. It is widely used, even in color machines.

However, in a conventional heat roller fixing type fixing device, it is necessary to heat a fixing roller having a large heat capacity when heating a transfer material or toner, so that the power saving effect is poor and disadvantageous in power saving. In addition, there is a problem that it takes time to warm up the fixing device at the time of printing, and the print start time (warming up time) becomes longer.

To solve this problem, a 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 brought into direct pressure contact with the heat fixing film. By doing so, a heat fixing efficiency is greatly improved, and a film fixing type fixing device or an image forming device which achieves power saving and quick start requiring almost no warm-up time has been proposed and recently used.

As another type of the quick start fixing method, there is a method in which a fixing roller member is formed using a translucent substrate, and a toner image is heated and fixed by irradiating a toner image with heat rays from a halogen lamp provided inside. JP-A Nos. 52-106741 and 57-82240 and 57-10273.
No. 6, No. 57-102741, and the like.

[0006]

In the above-mentioned fixing device using a translucent substrate as a fixing roller, when the driving member for driving and rotating the fixing roller and the end of the fixing roller are directly connected, the driving member is not used. It is difficult to connect without looseness and to drive with high accuracy due to the difference in the thermal expansion coefficient between the fixing member and the fixing roller, and insufficient accuracy of the light-transmitting substrate.

Even if a heat insulating member is interposed between the drive member and the end of the fixing roller, the means for preventing damage during heating and the tightening means for preventing relative movement are complicated. Further, it is difficult to perform key groove processing or key processing for engaging the driving member at the end of the fixing roller.

SUMMARY OF THE INVENTION The present invention solves a problem at a connecting portion between a fixing roller using a light-transmitting substrate and a driving member at an end portion of the fixing roller.
An object of the present invention is to provide a fixing device for quick start fixing with a short heating time.

According to the present invention, there is provided an image forming apparatus having the above-described fixing device, which achieves a quick start with a reduced warm-up time and a means for driving the fixing roller with high accuracy. It is an object of the present invention to provide an image forming apparatus having the same.

[0010]

According to the present invention, there is provided a fixing method in which a sheet is passed through a pressing position between a driving and rotating fixing roller and a pressing roller which is pressed against the fixing roller and rotated. Thus, in the fixing method of heating and fixing the toner image formed on the paper surface, the outer peripheral surface of one end of the fixing roller made of a hollow cylindrical light-transmitting substrate having a heating source disposed therein. A space between the inner peripheral surface of the driving member connected to the driving source, and a flexible drive transmission for connecting one end of the fixing roller and the driving member in the space. A member is arranged, and the fixing roller is rotated via the drive transmission member by rotation of the drive member (claim 1).

[0011] The fixing device of the present invention for solving the above-mentioned problems includes:
In a fixing device for heating and fixing a toner image formed on a sheet surface by passing a sheet to a pressure contact position between a driving roller and a fixing roller that rotates while being pressed against the fixing roller, The roller is formed of a hollow cylindrical light-transmitting substrate having a heating source disposed therein,
At one end of the fixing roller, a flexible drive transmission member that connects an inner peripheral surface of a driving member connected to a driving source and an outer peripheral surface of one end of the fixing roller is arranged. (Claim 2).

In the image forming apparatus of the present invention, the image forming apparatus including the fixing device including the fixing roller, the pressure roller, the heating source, and the drive transmitting member has a driving member connected to the driving source during an image forming operation. By rotating the fixing roller via the drive transmission member, except during the image forming operation,
The driving system of the image forming apparatus including the fixing roller reversely rotates by a predetermined amount or disconnects at least a part of the driving system to reduce a force of the drive transmission member pressing the fixing roller. It is a feature (claim 14).

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a fixing device according to the present invention and an image forming apparatus equipped with the fixing device will be described with reference to the drawings.

FIG. 1 is a configuration diagram showing a color printer which is an image forming apparatus equipped with a fixing device of the present invention.

In this color printer, a flexible endless belt-shaped photoconductor (hereinafter, referred to as a photoconductor) 1 serving as an image carrier is provided.
, Four sets of scorotron chargers (hereinafter referred to as chargers) 2Y, 2M, 2C, 2K, four sets of image exposure devices 3
Y, 3M, 3C, 3K, four sets of developing units 4Y, 4M, 4
The image forming units C and 4K (four sets as shown) are arranged in tandem. The illustrated image exposure apparatus 3
Y, 3M, 3C, and 3K use a laser beam scanning optical device.

The photosensitive member 1 is stretched around a driving roller 11, a lower roller 12, and an upper roller 13, and a tension roller 14
And is rotated clockwise as shown in the drawing while being locally brought into contact with the backup member 15 provided on the inner peripheral surface. The backup member 15 is in contact with the back surface of the photoreceptor 1 and develops the developing areas of the developer carriers 41Y, 41M, 41C, and 41K of the developing units 4Y, 4M, 4C, and 4K and the image exposure devices 3Y, 3M, 3C, and 4K. The photoconductor 1 is regulated at the 3K image forming position.

At the start of image recording, a drive motor (not shown) is rotated to rotate the photosensitive member 1 clockwise through a drive roller 11, and the photosensitive member is charged by a charging action of a charger 2Y. Application of the potential to 1 is started. Photoconductor 1
Is the first in the image exposure apparatus 3Y after the potential is applied.
Exposure is started by an electrical signal corresponding to the color signal of the photoconductor 1, ie, the yellow (Y) image signal, and the rotation (sub-scanning) of the photoconductor 1 causes the photosensitive layer on the surface to correspond to the yellow (Y) image of the developed image. An electrostatic latent image is formed. The developing device 4Y reversely develops the latent image in a non-contact state on the developer carrying member 41Y by the developing device 4Y to form a yellow (Y) toner image.

Next, the photoreceptor 1 is further provided with a potential on the yellow (Y) toner image by the charging action of the charger 2M, and is converted into a second color signal of the image exposure device 3M, that is, an image signal of magenta (M). Exposure is performed by the corresponding electric signal, and a magenta (M) toner image is formed on the yellow (Y) toner image by non-contact reversal development by the developing device 4M.

By the same process, a cyan (C) toner image corresponding to the third color signal is further formed by the charger 2C, the image exposure device 3C, and the developing device 4C. Further, a black (K) toner image corresponding to the fourth color signal is sequentially superimposed and formed by the charger 2K, the image exposure device 3K, and the developing device 4K, and is formed on the peripheral surface within one rotation of the photoconductor 1. A color toner image is formed.

The color toner image formed on the peripheral surface of the photoreceptor 1 reaches the transfer area after the potential of the attached toner is adjusted by the charger 2F. From the paper feed cassette 51 or the manual paper feed table 53 of the paper feed device 5,
The transfer material P sent out by the registration rollers 2 and 54 and conveyed to the registration roller pair 55 is fed by the driving of the registration roller pair 55 in synchronization with the passage of the toner image area on the photoconductor 1, and the lower portion of the drive roller 11 The toner image is transferred by the transfer means 6 disposed opposite to the toner image.

The transfer material P on which the toner image has been transferred is separated from the peripheral surface of the photoreceptor 1 and then conveyed to the fixing device 7. The fixing device 7 melts the toner image and fixes it to the transfer material P. After the completion of the fixing process, the transfer material P is conveyed by a conveyance roller 81 and a pair of paper discharge rollers 82 and 83, and is discharged to a paper discharge tray 84 provided at an upper portion.

On the other hand, the photoreceptor 1 from which the transfer material P has been separated is cleaned by removing the residual toner by the cleaning blade 91 of the cleaning device 9. When the formation of the toner image of the next original image is subsequently performed, the pre-charging static eliminator 92 exposes the photoconductor surface of the photoconductor 1 to remove the previous charge.

FIG. 2 is a sectional view showing an embodiment of the fixing device of the present invention, and FIG. 3 is a plan sectional view of the fixing device. FIG.
3 is an enlarged sectional view of a main part of a fixing roller 71, a pressure roller 72, and a halogen heater 73. FIG.

The fixing device 7 includes a fixing roller 71 using a translucent substrate, a pressure roller 72, and a halogen heater 7 as a heat source.
3, cleaning roller 74, cleaning pad 7
5, an oil applying means 76, a paper discharge roller 77 and the like.

The fixing roller 71 includes a hollow cylindrical translucent substrate 71a and an elastic layer 71 made of transparent silicone rubber.
b and the heat ray absorbing layer 71c are sequentially laminated and covered.

The translucent substrate 71a is a hollow cylindrical body made of heat-resistant glass or heat-resistant resin. As the translucent substrate 71a, Pyrex glass (manufactured by Corning Corporation, USA) or sapphire glass CaF ₂ that transmits heat rays such as infrared rays or far infrared rays emitted from the halogen heater 73 serving as a heating source.
And a translucent resin using polyimide (PI), polyamide imide (PAI), or the like.

The elastic layer 71b is a transparent silicone rubber layer coated on the outer peripheral surface of the translucent substrate 71a. The heat ray absorbing layer 71c is the outermost layer in which polytetrafluoroethylene (PTFE) containing carbon is laminated on the outer peripheral surface of the elastic layer 71b.

Both ends of the translucent base 71a are fitted to heat-resistant bearing members 71d held on the left and right fixing device body side plates 70, and are rotatable.

The heat rays emitted from the halogen heater 73 pass through the light-transmitting base 71a and the elastic layer 71b, are absorbed by the heat ray absorbing layer 71c, and can be rapidly heated.
1 is formed.

The pressure roller 72 is formed by coating an outer peripheral surface of a hollow cylindrical core member 72a made of a metal such as an aluminum alloy with an elastic member 72b such as silicone rubber. Both ends of the core member 72a are connected to the bearing member 72c.
Are supported rotatably. The bearing member 72c is
The pressure roller 72 is pressed against the fixing roller 71 by being urged by a spring 72d (see FIG. 3).

The cleaning roller 74 has a rotating shaft 74a.
And an elastic member 74b. Both shaft ends of the rotation shaft 74a are fitted to bearing members 74c held on the left and right fixing device body side plates 70, and are rotatable. The elastic member 74b is a roller made of a heat-resistant resin such as foamed silicone rubber (see FIG. 3).

The translucent substrate 71a is driven and rotated by a driving member via driving means connected to a driving source. In FIG. 3, a flexible drive transmission member 79 that connects the outer peripheral surface of one end of the translucent base 71a to the inner peripheral surface of a drive member 78 such as a gear is disposed.

FIG. 5 is an enlarged perspective view of the drive transmission means connected to the end of the fixing roller 71. FIG. 6 is an enlarged sectional view of the drive transmission means, and FIG.
8, shows a stopped state in which the translucent base 71a is not driven. FIG.
(B) shows a driving rotation state of the driving member 78 and the translucent base 71a.

A driving member 78 having an inner diameter larger than the outer diameter of the light-transmitting base 71a is provided at one end of the light-transmitting base 71a having a hollow cylindrical shape to form a space around the light-transmitting base 71a. It is installed concentrically with the translucent base 71a so as to cover it.

The drive member 78 has a key or a key groove for integrally transmitting the drive, which is formed integrally with the gear or fitted to a separate gear.

The translucent base 71a and the driving member 78 are connected by a drive transmitting member 79 having a length equal to or more than one circumference of the translucent base 71a. That is, one end of the drive transmission member 79 is fixed to the outer peripheral surface of the translucent base 71a with an adhesive or a clip.

The end of the drive transmitting member 79 and the drive member 78 are firmly fixed by screws or inserted into fixing grooves or the like via fixing members.

The drive transmission member 79 has a band shape and is formed of a bundle of metal wires or a braided metal wire. Alternatively, it is formed by bundling heat-resistant resin fibers or knitting heat-resistant resin fibers.

At the time of the fixing process by the fixing device 7, a driving force is transmitted from the driving member 78 to the driving transmitting member 79 in a direction in which the belt-shaped driving transmitting member 79 is wound around the translucent base 71a. The belt-shaped drive transmission member 79 includes a light-transmitting base 71a.
Of the outer peripheral surface of the driving member 7
8, the belt-shaped drive transmission member 79 is turned into a form that tightens the outer peripheral surface of the translucent base 71a by the counterclockwise rotation shown, and the drive transmission member 79 and the translucent base 71a are driven without slipping. The driving force from the member 78 can be transmitted smoothly and reliably.

During non-driving time other than during image forming operation, the belt-like drive transmitting member 79 causes the light-transmitting base 71a to be driven by a no-load condition of the driving means of the fixing device 7 or a small amount of reverse rotation.
Bondage is eased. In particular, when heating is released from the state where the light transmitting base 71a is heated and cooled,
When the belt-shaped drive transmission member 79 is tightly wound around the translucent base 71a, the belt-shaped drive transmission member 79 having a large thermal expansion coefficient contracts by cooling, so that the translucent base 71a is tightened. Crack.

In order to prevent the translucent substrate 71a from being damaged,
The drive transmission member 79 may be made of a material having a spring property. When the drive transmission member 79 is placed in a free state, the binding is released by having a radius of curvature larger than the radius of curvature of the drive transmission member 79.

If one end of the drive transmitting member 79 fixed to the light transmitting base 71a has a curvature larger than the curvature of the outer peripheral surface of the light transmitting base 71a, another member, an adhesive or the like is used. Instead, the drive transmission member 79 can be fixed to the outer peripheral surface of the translucent base 71a by its own spring property.

Further, the drive transmitting member 79 and the light transmitting substrate 71
It is preferable to interpose a flaw preventing member such as a resin member, a glass fiber or a metal fiber member between the outer peripheral surface of a.

The length of the belt-like drive transmission member 79 is
It is necessary that the distance be equal to or more than one round of the outer peripheral surface of the light transmitting substrate 71a. As the length of the drive transmitting member 79 becomes longer, the binding force on the outer peripheral surface of the light transmitting base 71a increases, and the driving member 78
Although the driving force transmitted to the light-transmitting base 71a increases, it takes time for the reverse rotation of the relaxation of the binding during non-driving, and at the start of driving, the belt-shaped driving transmitting member 79 is mutually There is a possibility that a loose binding state will occur, and the inside of the drive transmitting member 79 will not be caught in the outer peripheral surface of the translucent base 71a. Therefore, although it depends on the configuration conditions of the fixing device 7, the length of the drive transmitting member 79 is approximately 1.5 to 4 times the length of the outer peripheral surface of the translucent base 71a.

The fixing device of the present invention having the above configuration is
By driving the belt-shaped drive transmission member 79 around the outer peripheral surface of the light-transmitting substrate 71a, the drive is transmitted from the driving member 78 to the light-transmitting substrate 71a. , Drive member 78
A gap is secured between the inner peripheral surface and the outer peripheral surface of the translucent substrate 71a.

[0046]

According to the present invention, the following effects can be obtained by the configuration described above.

(1) There is provided a fixing device for quick-start fixing, in which damage at the end of the fixing roller using a light-transmissive substrate and the connection with the driving member is prevented, and the heating time is short.

(2) An image forming apparatus equipped with the above-mentioned fixing device can save power by improving thermal efficiency, shorten warm-up time, fix at high speed and fix high-quality images, stabilize and maintain images with a long service life and excellent maintainability. A forming device is provided.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a color printer which is an image forming apparatus provided with a fixing device of the present invention.

FIG. 2 is a sectional view showing an embodiment of the fixing device of the present invention.

FIG. 3 is a cross-sectional plan view of the fixing device.

FIG. 4 is an enlarged cross-sectional view of main parts of a fixing roller, a pressure roller, and a halogen heater.

FIG. 5 is an enlarged perspective view of a drive transmission unit connected to an end of a fixing roller.

FIG. 6 is an enlarged sectional view showing a non-drive stop state and a drive rotation state of the drive transmission means.

[Explanation of symbols]

 7 Fixing Device 70 Fixing Device Main Body Side Plate 71 Fixing Roller 71a Translucent Base 71b Elastic Layer 71c Heat Ray Absorbing Layer 71d Heat Resistant Bearing Member 72 Pressure Roller 72a Core Metal Member 72b Elastic Member 72c Bearing Member 72d Spring 73 Halogen Heater (Heat Source) ) 74 cleaning roller 75 cleaning pad 76 oil application means 77 paper discharge roller 78 drive member 79 drive transmission member P transfer material

Claims (14)

[Claims] 1. A fixing device that heats and fixes a toner image formed on a sheet surface by passing a sheet through a pressure contact position between a driving roller that rotates and a pressure roller that presses and rotates against the fixing roller. The method according to claim 1, wherein the fixing roller comprises a light-transmitting base having a hollow cylindrical shape and a heating source disposed therein. The fixing roller includes an outer peripheral surface at one end thereof and an inner peripheral surface of a driving member connected to the driving source. A space is formed, and a flexible drive transmission member that connects one end of the fixing roller and the drive member is disposed in the space, and the drive transmission member is rotated by rotation of the drive member. A fixing roller rotating the fixing roller via the fixing device. 2. A fixing device for heating and fixing a toner image formed on a surface of a sheet by passing the sheet through a pressure contact position between a driving roller that rotates and a pressure roller that presses and rotates against the fixing roller. In the apparatus, the fixing roller includes:
The fixing roller is formed of a hollow cylindrical light-transmitting base in which a heating source is disposed, and an inner peripheral surface of a driving member connected to a driving source and one end of the fixing roller are provided at one end of the fixing roller. A fixing device, wherein a flexible drive transmission member for connecting to an outer peripheral surface of the portion is provided. 3. The fixing device according to claim 2, wherein the translucent substrate is a hollow cylindrical body made of heat-resistant glass. 4. The fixing device according to claim 2, wherein the light-transmitting base is a hollow cylindrical body made of a heat-resistant resin. 5. The fixing device according to claim 2, wherein the heating source is a halogen heater. 6. An end of the drive transmission member is wound around an outer peripheral surface of one end of the fixing roller while being locked, and the other end of the drive transmission member is attached to an inner peripheral surface of the drive member. The fixing device according to claim 2, wherein the fixing device is locked. 7. The fixing device according to claim 2, wherein the drive transmission member has a length that makes one or more turns around the outer periphery of one end of the fixing roller. 8. The fixing device according to claim 2, wherein the drive transmission member has a belt shape. 9. The fixing device according to claim 8, wherein the drive transmission member is a bundle of metal wires or a braided metal wire. 10. The fixing device according to claim 8, wherein the drive transmission member is formed by bundling heat-resistant resin fibers or knitting heat-resistant resin fibers. 11. The fixing device according to claim 2, wherein the drive transmission member has a spring property on an outer peripheral surface of one end of the fixing roller. apparatus. 12. An outer peripheral radius of curvature of the fixing roller when the end of the drive transmitting member is placed in a free state over a length equal to or more than a half circumference of an outer peripheral surface of one end of the fixing roller. The fixing device according to claim 11, wherein the fixing device has a larger radius of curvature. 13. The fixing device according to claim 12, wherein a resin member, a glass fiber, or a metal fiber member is interposed between the drive transmission member and an outer peripheral surface of the fixing roller. 14. An image forming apparatus comprising a fixing device comprising a fixing roller, a pressure roller, a heating source, and a drive transmitting member according to claim 2, wherein the image forming apparatus is driven during an image forming operation. A driving member connected to a power source rotates the fixing roller through the driving transmission member, and when the image forming operation is not being performed, the driving system of the image forming apparatus including the fixing roller reversely rotates the fixing roller by a predetermined amount. An image forming apparatus, wherein at least a part of a drive system is disconnected to reduce a force of the drive transmission member pressing the fixing roller.