JP2014224935A - Fixing method, fixing apparatus, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing method configured to prevent a defect of a toner image on a recording medium which has partially reached a fixing nip, in a configuration having a vibration member which vibrates in contact with a fixing belt in a position other than the fixing nip, and to provide a fixing apparatus and an image forming apparatus including the fixing apparatus.SOLUTION: A fixing apparatus 100 includes: a fixing belt 2; a pressure roller 3 which forms a fixing nip 9 in contact with a surface of the fixing belt 2; and a vibrator 1 which vibrates in contact with the fixing belt 2 in a position other than the fixing nip 9. In a moving direction of the fixing belt 2, a distance from a vibration application unit 109, with which a vibration member comes into contact, to the fixing nip 9 is equal to or less than a distance from the fixing nip 9 to the vibration application unit 109. A vibration absorbing member 4 which absorbs the vibration in contact with the fixing belt 2 is arranged downstream of the vibration application unit 109 and upstream of the fixing nip 9 in the moving direction of the fixing belt.

Description

  The present invention relates to a fixing method, a fixing device, and an image forming apparatus.

  Image forming apparatuses such as printers, facsimile machines, and copying machines are apparatuses that form images including characters and symbols on recording media such as paper, cloth, and OHP sheets based on image information. In particular, electrophotographic image forming apparatuses are widely used in offices because they can form high-definition images on plain paper at high speed. In such an electrophotographic image forming apparatus, the toner on the recording medium is heated at 120 [° C.] to 160 [° C.] to be softened or melted, and the softened or melted toner is pressurized to thereby apply the toner. A thermal fixing method for fixing on a recording medium is widely used. This thermal fixing method is preferably used because it can provide a high fixing speed and high fixed image quality.

  In general, a fixing device of a heat fixing system includes a heating member that includes a heat source such as an infrared heater for heating, and a pressure member that contacts the heating member to form a fixing nip for fixing. By passing a recording medium such as transfer paper onto which a toner image has been transferred through a fixing nip formed by a heating member and a pressure member, the toner image is fixed on the recording medium by heating and pressing. It has become. In addition, since it takes time to set the heating member to a temperature necessary for fixing, there is also a case where the heating member is continuously energized so that the heating member does not become a certain temperature or less even when the apparatus is not fixed.

  About half or more of the power consumption in the electrophotographic image forming apparatus having such a heat fixing type fixing device is consumed in heating the toner in the fixing device. On the other hand, from the viewpoint of countermeasures for environmental problems in recent years, an image forming apparatus that can save energy by suppressing power consumption is desired. For this reason, there is a demand for energy saving in the fixing device that consumes more than half of the power consumption in the conventional image forming apparatus.

As a heat source of the heat fixing method, a fixing device that uses ultrasonic vibration without using a heater is disclosed in Patent Document 1, Patent Document 2, and the like.
In Patent Document 1, either a fixing roller that contacts a surface carrying a toner image of a recording medium at a fixing nip or a pressure roller that contacts a surface opposite to the surface carrying a toner of a recording medium at a fixing nip. A configuration including an ultrasonic generator that transmits the ultrasonic vibration is described. In this fixing device, the vibration energy of ultrasonic vibration is transmitted to the toner image, and the vibration energy becomes impact energy or friction energy, which is finally converted into thermal energy, and the toner image is fixed on the recording medium. In this fixing device, it is only necessary to apply ultrasonic vibration only when a recording medium carrying unfixed toner is in the fixing device, which leads to energy reduction.

  Patent Document 2 discloses a fixing belt that contacts a surface carrying a toner image of a recording medium at a fixing nip, and a pressure roller that contacts a surface opposite to the surface carrying a toner of a recording medium at the fixing nip. A fixing device including a vibrating member that vibrates in contact with the fixing belt is described. In this fixing device, the vibration member is in contact with the fixing belt at a position other than the fixing nip, and the vibration energy of the vibration member is converted into heat energy at the contact portion between the vibration member and the fixing belt, and the fixing belt is heated. The As the fixing belt moves endlessly, the heated portion of the fixing belt reaches the fixing nip, and the toner image is fixed on the recording medium.

  In the fixing device described in Patent Document 1, since the ultrasonic vibration is transmitted to the toner by vibrating the fixing roller or the pressure roller that forms the fixing nip, the ultrasonic vibration is not limited to the toner that has reached the fixing nip. It is also transmitted to the recording medium on which the toner is placed. When ultrasonic vibration is transmitted to a recording medium that partially reaches the fixing nip and the recording medium vibrates, the unfixed toner carried on the portion not reaching the fixing nip on the upstream side in the conveyance direction of the recording medium vibrates. There is a problem that the image is disturbed by the scattering.

  On the other hand, in the fixing device described in Patent Document 2, vibration energy is converted into thermal energy at a position other than the fixing nip, and the converted thermal energy is transmitted to the fixing nip by movement of the surface of the fixing belt. For this reason, it is possible to suppress transmission of ultrasonic vibration to the recording medium at the fixing nip, compared to a configuration in which vibration energy is applied to the toner at the fixing nip. However, at the contact portion between the vibration member and the fixing belt, only a part of the vibration energy of the vibration member may be converted into heat energy to heat the fixing belt, and the remaining vibration energy may vibrate the fixing belt. When the vibration of the fixing belt is transmitted to the fixing nip, the recording medium vibrates, and the unfixed toner carried on the portion not reaching the fixing nip on the upstream side in the conveyance direction of the recording medium is scattered by the vibration. There is a risk that the problem will be disturbed.

  The trouble that the toner image is disturbed by the vibration described above is not limited to the case where the frequency of vibration is a frequency at which ultrasonic vibration is generated, but the same problem occurs if the toner is heated by converting vibration energy into heat energy. .

  The present invention has been made in view of the above problems, and the objects thereof are as follows. That is, a fixing method, a fixing device, and a fixing device capable of suppressing the occurrence of a disturbance of a toner image on a recording medium that partially reaches the fixing nip with a vibration member that vibrates in contact with the fixing belt at a position other than the fixing nip, and An object of the present invention is to provide an image forming apparatus provided with this fixing device.

  In order to achieve the above object, the invention of claim 1 of the present application provides a fixing device comprising: a fixing belt that moves endlessly; and a pressure member that forms a fixing nip in contact with the surface of the fixing belt. A vibration member that vibrates in contact with the fixing belt at a position other than the position and a vibration absorbing member that absorbs vibration in contact with the fixing belt, and the vibration absorbing member is moved in the moving direction of the fixing belt. The distance from the vibration applying portion to the fixing nip in the moving direction of the fixing belt is arranged at a position downstream of the vibration applying portion that contacts the vibration member and upstream of the fixing nip. The distance is less than or equal to the distance from the fixing nip to the vibration applying portion.

  According to the present invention, in a fixing device including a vibrating member that vibrates in contact with the fixing belt at a position other than the fixing nip, the occurrence of toner image disturbance on a recording medium partially reaching the fixing nip is suppressed. There is an excellent effect of being able to.

FIG. 3 is an explanatory diagram of a fixing device according to the first embodiment. 1 is a schematic configuration diagram of a copier according to an embodiment. FIG. 3 is a partially enlarged view showing a part of a tandem type image forming unit. Explanatory drawing of Experimental example 1 which observed the temperature distribution when the ultrasonic vibration was provided to the belt member which comprises a fixing belt. FIG. 4 is an explanatory diagram of a fixing device according to a second embodiment. FIG. 6 is an explanatory diagram of a fixing device according to a modification. FIG. 6 is an explanatory diagram of a fixing device having the configuration described in Patent Document 4.

  Hereinafter, an embodiment in which the present invention is applied to an electrophotographic copying machine (hereinafter simply referred to as a copying machine 500) will be described. The copier 500 described below is an example of an image forming apparatus to which the present invention can be applied, and the present invention is not limited to this.

First, the basic configuration of the copying machine 500 will be described.
FIG. 2 is a schematic configuration diagram showing the copying machine 500. In the following, an image forming apparatus according to an embodiment of the present invention will be described. The copier 500 is a tandem type color image forming apparatus, and includes a printer unit 150 as a toner image forming unit that is a main body of the image forming apparatus, a paper feeding device 200, a scanner 300, and an automatic document feeder (ADF) 400. And.

The printer unit 150 is provided with an endless belt-shaped intermediate transfer belt 50 at the center. The intermediate transfer belt 50 is stretched around three support rollers, that is, a belt driving roller 14, a cleaning counter roller 15, and a secondary transfer counter roller 16, and can rotate clockwise in FIG. In the vicinity of the cleaning counter roller 15, an intermediate transfer belt cleaning device 17 that is an intermediate transfer belt cleaning unit for removing residual toner on the intermediate transfer belt 50 is disposed.
In addition, four image forming units corresponding to toners of yellow, cyan, magenta, and black are provided along the outer stretched surface between the belt driving roller 14 and the cleaning counter roller 15 of the intermediate transfer belt 50. 18 (Y, C, M, K) are juxtaposed. The four image forming units 18 (Y, C, M, K) are arranged in the order of yellow (Y), cyan (C), magenta (M), and black (K) from the upstream side in the moving direction of the intermediate transfer belt 50. And tandem type image forming unit 120.

  An exposure device 21 is disposed above the tandem type image forming unit 120. The secondary transfer device 22 is disposed on the opposite side (below the intermediate transfer belt 50) to the side where the tandem image forming unit 120 is disposed with the intermediate transfer belt 50 interposed therebetween. In the secondary transfer device 22, a transfer conveyance belt 24 that is an endless belt is stretched around a pair of transfer conveyance support rollers 23, and one of the pair of transfer conveyance support rollers 23 is rotationally driven as a drive roller. The transfer / conveying belt 24 is driven to rotate counterclockwise in FIG. Further, the right side transfer conveyance support roller 23 and the secondary transfer counter roller 16 in FIG. 2 are in contact with each other with the intermediate transfer belt 50 and the transfer conveyance belt 24 interposed therebetween. A contact portion with the conveyance belt 24 becomes a secondary transfer nip.

A fixing device 100 for fixing the toner image on the transfer paper S is disposed on the downstream side (left side in FIG. 2) of the transfer paper S that is a recording medium by the secondary transfer device 22 in the printer unit 150. . The fixing device 100 includes a fixing belt 2, which will be described in detail later, and a pressure roller 3 that is pressed by a pressing unit (not shown) such as a spring and forms a fixing nip at a contact portion with the fixing belt 2. Yes.
Below the secondary transfer device 22 and the fixing device 100 in the printer unit 150, a reversing device 28 that reverses the transfer paper S when an image is formed on both sides of the transfer paper S is disposed.

  Next, formation of a full color image (color copy) using the copying machine 500 will be described. First, a document is set on the document table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and a document is set on the contact glass 32 of the scanner 300. close up.

  When the user presses the start switch on the operation panel (not shown), when the document is set on the automatic document feeder 400, the document is transported and moved onto the contact glass 32, and then the scanner 300 is driven. The first traveling body 33 and the second traveling body 34 travel. On the other hand, when a document is set on the contact glass 32, the scanner 300 is immediately driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, the light from the light source is irradiated by the first traveling body 33 so that the light is reflected by the document surface, and the reflected light is reflected by the mirrors in the first traveling body 33 and the second traveling body 34, Light is received by the reading sensor 36 through the imaging lens 35. As a result, a color original (color image) is read and used as black, yellow, magenta, and cyan image information.

  Each image information of black, yellow, magenta, and cyan is transmitted to the exposure device 21, and exposure light corresponding to each image information is directed to each photoreceptor 10 of each image forming unit 18 in the tandem type image forming unit 120. Each is irradiated. As a result, black, yellow, magenta, and cyan toner images are formed in each image forming unit 18.

  FIG. 3 is a partially enlarged view showing a part of a tandem type image forming unit 120 including four image forming units 18 (Y, C, M, K). The four image forming units 18 (Y, C, M, and K) have substantially the same configuration except that the colors of the toners to be used are different from each other. Therefore, in FIG. , K are omitted. As shown in FIG. 3, the image forming unit 18 includes a drum-shaped photoconductor 10, and a charging device 160 as a charging unit, a developing device 61, and a primary transfer roller as a primary transfer unit around the photoconductor 10. 62, a photoconductor cleaning device 63, a charge removal device 64, and the like.

  As the photosensitive member 10, a drum-shaped member is used in which a photosensitive organic layer is applied to a base tube made of aluminum or the like to form a photosensitive layer. However, an endless belt may be used. Further, as the charging device 160 that uniformly charges the surface of the photoconductor 10, a device that rotates a charging roller to which a charging bias is applied while contacting the photoconductor 10 is used. As the charging means, a scorotron charger or the like that performs a non-contact charging process on the photoreceptor 10 may be used. The photosensitive member 10 uniformly charged by the charging device 160 is irradiated with the exposure light L by the exposure device 21 based on the image information corresponding to each color, and the electrostatic latent image corresponding to the image information of each color on the surface thereof. Is formed.

  The developing device 61 develops the electrostatic latent image formed on the photoconductor 10 using a two-component developer containing a magnetic carrier and a nonmagnetic toner. An agitating unit 66 that conveys the two-component developer contained therein and supplies the developer sleeve 65 with stirring, and development that transfers toner of the two-component developer attached to the developing sleeve 65 to the photoreceptor 10. Part 67.

  The stirring unit 66 is provided at a position lower than the developing unit 67, and is provided on the bottom surface of the two conveying screws 68 arranged in parallel with each other, a partition plate provided between the conveying screws 68, and the developing case 70. The toner density sensor 71 is provided.

  The developing unit 67 includes a developing sleeve 65 that faces the photoreceptor 10 through the opening of the developing case 70, a magnet roller 72 that is non-rotatably provided inside the developing sleeve 65, a doctor blade 73 that approaches the developing sleeve 65, and the like. ing. The distance at the closest portion between the doctor blade 73 and the developing sleeve 65 is set to about 500 [μm].

  The developing sleeve 65 has a non-magnetic rotatable sleeve shape. Further, the magnet roller 72 that does not rotate with the developing sleeve 65 has, for example, five magnetic poles N1, S1, N2, S2, and S3 in the rotation direction of the developing sleeve 65 from the position of the doctor blade 73. These five magnetic poles act on the two-component developer on the developing sleeve 65 at a predetermined position in the rotational direction. As a result, the two-component developer sent from the stirring unit 66 is attracted and carried on the surface of the developing sleeve 65, and a magnetic brush is formed on the surface of the developing sleeve 65 along the lines of magnetic force.

  The magnetic brush is transported to a developing region facing the photoreceptor 10 after being regulated to an appropriate layer thickness when passing through a position facing the doctor blade 73 as the developing sleeve 65 rotates. Then, due to the potential difference between the developing bias applied to the developing sleeve 65 and the electrostatic latent image on the photoconductor 10, it is transferred onto the electrostatic latent image and contributes to development. Further, as the developing sleeve 65 rotates, the developing sleeve 65 returns to the developing portion 67 again. In the stirring unit 66, an appropriate amount of toner is supplied to the two-component developer based on the detection result by the toner density sensor 71. The developing means used in the image forming apparatus to which the present invention is applied may be one that uses a one-component developer that does not contain a magnetic carrier instead of using a two-component developer as in the developing device 61. Good.

  The toner image developed by the developing device 61 and formed on the photoconductor 10 is in contact with the photoconductor 10 via the intermediate transfer belt 50 and a primary transfer roller 62 that forms a primary transfer nip. The image is transferred onto the intermediate transfer belt 50 by a primary transfer electric field formed by a potential difference.

  As the photoconductor cleaning device 63, a system that presses the cleaning blade 75 made of polyurethane rubber against the photoconductor 10 is used, but another system may be used. The photoconductor cleaning device 63 employs a cleaning device having a contact conductive fur brush 76 whose outer peripheral surface is brought into contact with the photoconductor 10 to be rotatable in the direction of the arrow in the drawing for the purpose of improving the cleaning property. A metal electric field roller 77 for applying a bias to the fur brush 76 is provided so as to be rotatable in the direction of the arrow in the figure, and the tip of the scraper 78 is pressed against the electric field roller 77. The toner removed from the electric field roller 77 by the scraper 78 falls on the collecting screw 79 and is collected.

  The photoconductor cleaning device 63 having such a configuration removes residual toner on the photoconductor 10 with a fur brush 76 that rotates in a counter direction with respect to the photoconductor 10. The toner adhering to the fur brush 76 is removed by the electric field roller 77 to which a bias that rotates in contact with the fur brush 76 in the counter direction is applied. The toner adhering to the electric field roller 77 is cleaned by the scraper 78. The toner recovered by the photoconductor cleaning device 63 is brought to one side of the photoconductor cleaning device 63 by the recovery screw 79 and returned to the developing device 61 by the toner recycling device 80 for reuse.

  The static eliminator 64 includes a static elimination lamp or the like, and removes the surface potential of the photoconductor 10 by irradiating light. The surface of the photoreceptor 10 that has been neutralized in this way is uniformly charged by the charging device 160, and then an optical writing process for forming an electrostatic latent image is performed by the exposure device 21.

As described above, the four image forming units 18 (Y, C, M, and K) of the tandem type image forming unit 120 generate a single color toner image on the surface of each photoconductor 10 based on the corresponding color image information. It can be formed on top.
The yellow, magenta, cyan, and black toner images formed in this manner are sequentially primary-transferred onto the intermediate transfer belt 50 that moves on the surface.
Then, yellow, cyan, magenta, and black toner images are superimposed on the intermediate transfer belt 50 to form a color toner image.

On the other hand, in the paper feeding device 200, one of the paper feeding rollers 142 is selectively rotated to feed the transfer paper S from one of the paper feeding cassettes 144 provided in multiple stages in the paper bank 143, and one sheet at a time by the separation roller 145. Separated and sent to the paper feed path 146. Then, the sheet is conveyed by the conveyance roller 147 and guided to the main body side paper feed path 148 in the printer unit 150, and is abutted against the registration roller 49 and stopped. Alternatively, the manual sheet feeding roller 51 is rotated to feed the transfer paper S on the manual tray 54, separated one by one by the manual separation roller 52, put into the manual sheet feeding path 53, and abutted against the registration roller 49 in the same manner as described above. Stop.
The registration roller 49 is generally used while being grounded, but may be used in a state where a bias is applied to remove the paper dust of the transfer paper S.

  After abutting against the registration roller 49 and stopping, the registration roller 49 is rotated in synchronization with the color toner image synthesized on the intermediate transfer belt 50, and the transfer sheet S is sent out to the secondary transfer nip. . A color toner image on the intermediate transfer belt 50 is transferred onto the transfer sheet S by a transfer electric field formed between the transfer conveyance support roller 23 on the secondary transfer device 22 side and the secondary transfer counter roller 16 in the secondary transfer nip. Secondary transfer is performed, and a color toner image is carried on the transfer paper S. The transfer residual toner on the intermediate transfer belt 50 after passing through the secondary transfer nip is cleaned by the intermediate transfer belt cleaning device 17.

  The transfer sheet S on which the color image is formed is conveyed by the secondary transfer device 22 and sent to the fixing device 100. In the fixing device 100, heat and pressure are applied at a fixing nip formed by the fixing belt 2 and the pressure roller 3 to fix the above-described color toner image on the transfer paper S.

  The transfer sheet S that has passed through the fixing device 100 is given a conveying force by the post-fixing conveying roller pair 56 and reaches the position of the switching claw 55. The transfer sheet S is discharged by the discharge roller pair 156 by being switched in the transport direction by the switching claw 55 and stacked on the discharge tray 57. Alternatively, the conveyance direction is switched by the switching claw 55 so that the reversing device 28 is conveyed. Then, the image is reversed by the reversing device 28 and led to a position where it again strikes the registration roller 49, and an image is formed on the back surface at the secondary transfer nip and fixed by the fixing device 100, and then discharged by the discharge roller pair 156. Stacked on the paper tray 57.

Embodiment 1
Next, a first embodiment of the fixing device 100 to which the present invention is applied (hereinafter referred to as the first embodiment) will be described.
FIG. 1 is an explanatory diagram of a fixing device 100 according to the first embodiment.
As shown in FIG. 1, the fixing device 100 according to the first embodiment includes a vibrator 1 that is a vibration member, an endless belt-like fixing belt 2, and a pressure member that forms a fixing nip 9 in contact with the fixing belt 2. The pressure roller 3 and the vibration absorbing member 4 are provided.

The vibrator 1 vibrates in contact with the fixing belt 2 by the vibration applying unit 109. The vibrator 1 includes a vibrator (not shown) that generates ultrasonic vibration and a horn member 101 that amplifies the amplitude of vibration generated by the vibrator. As the vibrator, an electrostrictive vibrator such as PZT (lead zirconate titanate) or a ferrite magnetostrictive vibrator can be used. Here, PZT is used. The material of the horn member 101 is preferably a metal, and aluminum, stainless steel, titanium, or the like can be used, but the fixing device 100 uses aluminum for ease of processing.
When a voltage having the same frequency as the resonance frequency of the vibrator (for example, 28 [kHz]) is applied to the PZT from the drive circuit (not shown), the vibrator 1 resonates due to the electrostriction of the PZT, and the electric energy becomes vibration energy. Converted.

The fixing belt 2 is stretched around a first stretching roller 5 and a second stretching roller 6 which are stretching members. Then, the first stretching roller 5 or the second stretching roller 6 is driven and rotated in the clockwise direction (arrow A1 direction) in FIG. 1, so that the fixing belt 2 is also rotated in the clockwise direction (arrow A direction in FIG. 1). ) Move endlessly.
The first stretching roller 5 is a roller-shaped stretching member in which a rubber layer is formed on the outer periphery of the core material, and is opposed to the end surface of the horn member 101 that is the output end surface of the vibrator 1 with the fixing belt 2 interposed therebetween. It is arranged at the position to do.

  When the end surface of the horn member 101 comes into contact with the fixing belt 2 and vibrates, the surface layer of the first stretching roller 5 vibrates and generates heat, and the fixing belt 2 is heated. Thus, the vibration energy generated in the vibrator 1 is converted into heat energy. However, in the vibration applying unit 109 that is a contact portion between the horn member 101 and the fixing belt 2, not all vibration energy is converted into heat energy, and the fixing belt 2 that has passed through the contact portion is in a vibrating state.

  The core material of the first tension roller 5 is desirably a metal such as aluminum, iron, and stainless steel or a hard material such as ceramics. This is because if a flexible material is used for the core material, when the vibrator 1 vibrates, the elastic material formed on the outer periphery of the core material cannot be sufficiently compressed, and heat cannot be generated efficiently. Because. Silicone rubber, chloroprene rubber, or the like can be used as the elastic material provided on the outer periphery of the core member and formed on the surface layer of the roller member.

As the fixing belt 2, a metal material such as nickel or stainless steel, or a resin material such as polyimide, polyetheretherketone, or aramid fiber can be used. Furthermore, in order to smoothly convey the transfer sheet S at the fixing nip, it is more preferable that the surface of the fixing belt 2 is formed with a fluorine-based resin layer such as silicone resin, PFA, or PTFE.
The second tension roller 6 and the pressure roller 3 have the same configuration as the first tension roller 5, and an elastic layer is formed on the surface of a core material of a hard material such as a metal such as aluminum, iron or stainless steel or ceramics. And made a roller. The pressure roller 3 is rotationally driven in the direction of arrow C in FIG. 1 when rotational drive is input from a drive motor (not shown).
The fixing nip 9 is a portion where the fixing belt 2 is sandwiched between the second stretching roller 6 and the pressure roller 3 facing the second stretching roller 6.

  Further, in the moving direction of the fixing belt 2, the vibration absorbing member is in contact with the inner peripheral surface of the fixing belt 2 on the downstream side of the vibration applying unit 109 with which the vibrator 1 contacts and on the upstream side of the fixing nip 9. 4 is arranged. As will be described in detail later, the vibration absorbing member 4 generates heat by absorbing the vibration of the fixing belt 2, and heats the fixing belt 2 by applying the generated heat to the fixing belt 2.

In the fixing device 100, ultrasonic vibration is applied to the fixing belt 2 by the vibrator 1. At this time, the vibration propagates to the fixing belt 2 and the vibration is transmitted to the elastic layer of the first stretching roller 5 so that the elastic layer generates heat. Further, the vibration propagating through the fixing belt 2 is absorbed by the vibration absorbing member 4 and the vibration absorbing member 4 generates heat.
The fixing belt 2 is heated by the heat generated by the first stretching roller 5 and the vibration absorbing member 4, and the fixing nip 9 of the fixing belt 2 is transferred by heat transfer from the heated portion and endless movement of the fixing belt 2. The temperature of the part that forms is increased. Then, the fixing belt 2 whose temperature has been raised and the transfer sheet S on which the unfixed toner image is formed by the unfixed toner 7 enter the fixing nip 9, and the pressure by the second stretching roller 6 and the pressure roller 3 Heat from the fixing belt 2 is applied to fix the toner on the transfer paper S. As a result, the toner on the transfer paper S becomes the fixing toner 8 and a fixed image is obtained.

  The vibration absorbing member 4 is flexible and needs to absorb the vibration of the fixing belt 2, but preferably has a high thermal conductivity in order to efficiently transmit heat generated by the vibration absorption to the fixing belt 2. Specifically, λGEL (trade name: Taika Co., Ltd.) is preferable because of its high thermal conductivity and heat resistance.

  In the fixing device 100, the distance from the vibration applying unit 109 to the fixing nip 9 on the downstream side in the moving direction of the fixing belt 2 with respect to the vibration applying unit 109 is downstream in the moving direction of the fixing belt 2 with respect to the fixing nip 9. The distance from the fixing nip 9 to the vibration applying unit 109 is equal to or less than the distance. Since the vibration transmission speed is faster than the moving speed of the fixing belt 2, the vibration is also transmitted to the vibration applying unit 109 toward the upstream side in the moving direction of the fixing belt 2. However, since the fixing belt 2 moves in the opposite direction to the vibration from the vibration applying unit 109 to the upstream side, the distance that the vibration is transmitted to the fixing belt 2 becomes longer than the apparent distance, and the fixing nip 9 Vibrations tend to attenuate before transmission. On the other hand, the vibration toward the downstream side in the movement direction of the fixing belt 2 with respect to the vibration applying unit 109 is such that the vibration transmission direction and the movement direction of the fixing belt 2 coincide with each other. The transmission distance is shortened and vibrations are difficult to attenuate.

Therefore, if the distance from the vibration applying unit 109 to the fixing nip 9 is equal to or less than the distance from the fixing nip 9 to the vibration applying unit 109 in the moving direction of the fixing belt 2, the vibration from the vibration applying unit 109 toward the downstream side. Is less likely to attenuate during transmission to the fixing nip 9.
In the fixing device 100 according to the first exemplary embodiment, the vibration transmission path in which the vibration is difficult to attenuate before the vibration is transmitted to the fixing nip 9, that is, the downstream side of the vibration applying unit 109 and the upstream side of the fixing nip 9. The vibration absorbing member 4 is disposed on the surface. The vibration absorbing member 4 is arranged at such a position and the vibration is absorbed to suppress the toner image disturbance. Further, since the portion of the fixing belt 2 to which heat generated by vibration absorption is applied is directed to the fixing nip 9 by endless movement of the fixing belt 2, heat generated by vibration absorption can be efficiently transmitted to the fixing nip 9, The toner can be softened or melted efficiently.

[Experimental Example 1]
Next, Experimental Example 1 in which heat generation by the vibration absorbing member 4 is confirmed will be described.
FIG. 4 is an explanatory diagram of Experimental Example 1 in which the temperature distribution is observed when ultrasonic vibration is applied to the belt member 201 constituting the fixing belt 2.
In Experimental Example 1, the belt member 201 is placed on the base 202 of the hard member, the tip of the vibrator 1 is brought into contact with one end of the upper surface of the belt member 201, and the arrangement condition of the vibration absorbing member 4 is changed. Thus, the temperature distribution of the belt member 201 when the vibrator 1 was ultrasonically vibrated was observed. In Experimental Example 1, the position of the belt member 201 is fixed with respect to the base 202 and the vibrator 1, and heat does not move due to the movement of the belt member 201.

An elastic member (not shown) such as a silicone sheet is laid under the belt member 201 at a portion where the vibrator 1 contacts the upper surface of the belt member 201.
When the vibrator 1 is vibrated in this state, the elastic member in the vicinity of the vibrator 1 is repeatedly subjected to compression and release forces, and as a result, the vibration energy is converted into heat energy. The energy conversion at this time is considered to occur as follows. That is, the elastic member is repeatedly deformed by vibration, so that the contact position between the surface of the belt member 201 and the surface of the elastic member and the contact position between the surface of the belt member 201 and the surface of the vibrator 1 are repeatedly minutely displaced. To do. When the contact position is slightly displaced, dynamic friction acts on the contact position to generate frictional heat, and the faster the frequency, the higher the relative velocity of displacement of the contact position and the higher the frictional heat. It is done. Further, the belt member 201 and the elastic member are repeatedly subjected to minute deformation due to vibration, and it is considered that frictional heat is also generated due to internal friction of each member due to the deformation.
The temperature distribution when ultrasonic vibration was applied to the belt member 201 was observed with a thermoviewer. In FIG. 4, the temperature level is schematically indicated by the color intensity, and the dark color indicates a high temperature.

  4A, the vibration absorbing member 4 is attached to the other end of the upper surface of the belt member 201, and the vibration absorbing member 4 is not disposed under the condition of FIG. 4B. 4C, the first vibration absorbing member 4a is attached to the same position as the vibration absorbing member 4 of FIG. 4A, and the position where the vibrator 1 contacts and the first vibration absorbing member 4a are set. The second vibration absorbing member 4b is pasted on the upper surface of the belt member 201 between the pasted position.

The temperature of the belt member 201 shown in FIG. 4A is the highest in the vicinity of the first heat generating portion H1 where the temperature of the belt member 201 is increased by the vibration of the vibrator 1, and the temperature becomes lower as the distance increases. However, although the portion where the vibration absorbing member 4 is attached is farthest from the vibrator 1, it becomes higher in temperature than the vicinity thereof, and the second heat generating portion H2 is formed.
When the present inventors diligently investigated about this cause, when the vibration energy which propagated the belt member 201 was absorbed by the vibration absorption member 4, the hypothesis that it was converted into thermal energy was derived.

  In order to verify this hypothesis, an experiment was performed under the conditions shown in FIG. When the vibration absorbing member 4 is peeled off and the vibrator 1 is vibrated as in the condition shown in FIG. 4B, the portion where the vibration absorbing member 4 is attached under the condition of FIG. There wasn't. From the experimental results under the conditions shown in FIGS. 4A and 4B, it was confirmed that the vibration absorbing member 4 absorbs vibration and generates heat. When the vibration absorbing member 4 absorbs vibration, the vibration absorbing member 4 repeats minute deformation to generate internal friction, which is considered to generate heat due to frictional heat generated by the internal friction.

Next, an experiment was performed under the conditions shown in FIG. When the vibration of the vibrator 1 is applied under the condition shown in FIG. 4A as in the condition shown in FIG. 4C, the portion where the second vibration absorbing member 4b is attached becomes hotter than its vicinity, and the vibrator 1 became the 2nd heat generating part H2 of the temperature equivalent to the 1st heat generating part H1 which 1 contacts. Further, on the side away from the vibrator 1 (left side in the figure), no heat was generated at all even though the first vibration absorbing member 4a was arranged. From the result of the condition shown in FIG. 4C, if all the vibration of the vibrator 1 is absorbed and converted into heat by the second vibration absorbing member 4b, the vibration is transmitted to the side farther from the vibrator 1 than the position. It was confirmed that there was no.
From the experimental results of Experimental Example 1, in the fixing device using ultrasonic vibration, if the vibration part, the vibration absorption part, and the fixing nip part are separated from each other, the toner can be efficiently softened or melted, and It was found that toner scattering can be prevented.

  In the fixing device 100 according to the first embodiment illustrated in FIG. 1, a vibration unit in which the vibrator 1 is in contact with the fixing belt 2, a vibration absorbing unit in which the vibration absorbing member 4 is in contact, and a fixing nip 9 are provided. Each is a separate configuration. With such a configuration, the vibration energy is converted into heat energy by the vibration part and the vibration absorption part, and the temperature of the fixing belt 2 is raised and heat fixing at the fixing nip 9 can be performed. Since the temperature of the fixing belt 2 is raised while absorbing the vibration by the vibration absorbing portion, the toner can be efficiently softened or melted. Further, since the vibration is absorbed by the vibration absorbing unit, the vibration is not transmitted to the side farther from the vibrator 1 than the vibration absorbing unit, that is, the downstream side in the moving direction of the fixing belt 2, and therefore the transfer sheet S passing through the fixing nip 9. It is possible to suppress the vibration from being transmitted. As a result, toner scattering caused by vibration of the transfer sheet S can be suppressed.

The vibration frequency of the vibration applied by the vibrator 1 is desirably in the range of 20 [kHz] or more and 1 [MHz]. When the frequency is 20 [kHz] or lower, it is a human audible sound range, and when the fixing device 100 is operated, noise is generated to the surroundings. Further, the heat generation interval due to vibration becomes long, and heat dissipation to the surroundings cannot be ignored, and the temperature required for fixing cannot be obtained. Further, at a frequency of 1 [MHz] or more, the amplitude of the vibration tool is reduced, so that the amount of heat generation is reduced, and the temperature necessary for fixing cannot be obtained.
Further, the vibration absorbing member 4 is preferably disposed at a position upstream of the fixing nip 9 in the moving direction of the fixing belt 2 and in the vicinity of the fixing nip 9. This is to prevent heat generated by being converted into thermal energy by the vibration absorbing member 4 from being dissipated before reaching the fixing nip 9.

[Embodiment 2]
Next, a second embodiment (hereinafter, referred to as a second embodiment) of the fixing device 100 to which the present invention is applied will be described.
FIG. 5 is an explanatory diagram of the fixing device 100 according to the second embodiment.
Similar to the fixing device 100 of the first embodiment, the fixing device 100 of the second embodiment forms a fixing nip 9 by contacting the vibrator 1 as a vibration member, the endless belt-like fixing belt 2, and the fixing belt 2. A pressure roller 3 that is a pressure member to be operated, and a vibration absorbing member 4.
The fixing device 100 according to the second embodiment is a pair of rollers, unlike the fixing device 100 according to the first embodiment, in the shape of the vibration absorbing member 4. Since other points are common, description of common points is omitted.
Since the shock absorbing material constituting the vibration absorbing member 4 is generally made of a material having an adhesive surface, the fixing belt 2 is difficult to move smoothly. Therefore, in the second embodiment, the vibration absorbing member 4 is a roller pair composed of two rollers in which an impact absorbing material is wound around the outer periphery of a hard core material. The vibration absorbing member 4 composed of the roller pair comes into contact with the fixing belt 2 and rotates along with the endless movement of the fixing belt 2, so that the movement of the fixing belt 2 is smoothed by the roller while absorbing vibration.

Here, a conventional fixing device will be described.
In Patent Document 3, a temporary fixing device for temporarily fixing unfixed toner, which is carried on a recording medium before reaching the fixing nip and to which no ultrasonic vibration is applied, to the recording medium is provided rather than the fixing nip. A fixing device disposed on the upstream side in the conveyance direction is described. In this fixing device, the unfixed toner before reaching the fixing nip is temporarily fixed to the recording medium, thereby preventing the image from being disturbed due to the vibration of the recording medium. As the temporary fixing device, a device using magnetic force, fixing solution, and preheating is shown.

  Among the temporary fixing devices described in Patent Document 3, in the configuration using magnetic force, since the toner for temporary fixing needs to be magnetic toner, the application range is limited. In general, magnetic toners have a problem that they are not suitable for color toners and can only be applied for monochrome use due to the influence of coloring resulting from the inclusion of the magnetic substance contained in the metal powder.

  In addition, among the temporary fixing devices described in Patent Document 3, as a configuration using a fixing solution, a configuration in which a fixing solution is applied to unfixed toner by an ultrasonic spray method or an inkjet method is described. As the ultrasonic spray method, a configuration is described in which the fixing liquid is atomized by applying ultrasonic vibration to the fixing liquid to scatter droplets of the fixing liquid, and the fixing liquid is applied to the unfixed toner. . In the case of such an ultrasonic spray method, there is a possibility that the fixing liquid reaches not only on the toner but also everywhere in the image forming apparatus, and the parts inside the apparatus are damaged by the fixing liquid and may fail.

  As an ink jet system, Patent Document 3 describes a configuration in which a fixing liquid is applied to unfixed toner by discharging the fixing liquid toward unfixed toner on a recording medium. In such an ink jet method, there is a problem that the unfixed toner moves in the landing portion of the fixing liquid due to the landing of the fixing solution, and the toner image is disturbed on the crater. With respect to this problem, Patent Document 3 describes that since the fixing can be surely performed by the thermal energy generated by the ultrasonic vibration, the turbulent toner image can be immediately corrected. The area where the area of the toner image is wide may be restored by applying thermal energy of ultrasonic vibration to the toner image disordered in a crater shape, and fixing it by melting or softening the toner. There is. However, in a portion having a small area such as a thin line portion, there is a problem that the toner image in which the toner has moved due to the landing of the fixing liquid cannot be restored, and the image is lost.

Further, among the temporary fixing devices described in Patent Document 3, in the configuration using preheating, a heating source such as a halogen lamp or a ceramic heater for preheating is separately required, and ultrasonic vibration is not used without using a heater. The advantage of the configuration used is lost.
Thus, as described in Patent Document 3, there is a problem that it is difficult to realize a configuration that uses ultrasonic vibration and includes a temporary fixing device.

  Japanese Patent Application Laid-Open No. H10-228561 describes a fixing device configured by arranging a vibrating member inside a fixing belt portion forming a fixing nip. In this fixing device, the recording medium is fed so as to come into contact with the surface portion of the fixing belt upstream of the fixing nip in the moving direction of the fixing belt. Vibration absorption that absorbs the vibration of the fixing belt on the downstream side in the movement direction of the fixing belt with respect to the surface portion where the recording medium to be fed first contacts the fixing belt and on the upstream side in the movement direction of the fixing belt with respect to the fixing nip. The member is arranged. In the fixing device described in Patent Document 4, the ultrasonic vibration of the fixing belt at the fixing nip transmits the vibration to the surface portion where the recording medium upstream from the position where the vibration absorbing member is disposed first contacts the fixing belt. Can be prevented. For this reason, it is possible to prevent the toner image from being disturbed when a recording medium carrying unfixed toner comes into contact. However, since the ultrasonic vibration is transmitted to the recording medium in the fixing nip in the thickness direction of the fixing belt, the unfixed toner carried on the portion of the recording medium that has not reached the fixing nip is scattered by the vibration, The problem of distorted images cannot be solved.

  Patent Document 4 describes the configuration of the fixing device 100 shown in FIG. 7 including an endless belt to which vibration of a vibration member is applied and a member for preventing vibration from propagating through the endless belt.

The fixing device 100 shown in FIG. 7 includes a driving roller 212, a guide roller 211, and two tension rollers 210 as stretching members for stretching the fixing belt 2, and the fixing belt 2 is endless in the direction of arrow A in FIG. Moving.
At the fixing nip 9 where the fixing belt 2 and the pressure roller 3 abut, the vibrating tip of the vibrator 1 contacts the inside of the fixing belt 2, and the vibrator 1 vibrates in the direction indicated by the arrow B in FIG. .
In the fixing device 100 shown in FIG. 7, the transfer sheet S carrying the unfixed toner 7 is brought into close contact with the fixing belt 2 and conveyed to the fixing nip 9. At the fixing nip 9, the transfer sheet S is sandwiched between the fixing belt 2 and the pressure roller 3, and the vibrator 1 transmits ultrasonic vibration to the toner on the transfer sheet S via the fixing belt 2 to directly heat the toner. It has become established.

  Patent Document 4 describes a configuration in which the belt surface of the fixing belt 2 in the fixing device 100 shown in FIG. 7 is made of a rubber layer, or silicone oil is applied to the belt surface to prevent toner scattering. In addition, a configuration in which a vibration propagation preventing member 204 is provided upstream of the fixing nip 9 in the endless movement direction of the fixing belt 2 is described. In the fixing device 100 shown in FIG. 7, the toner can be efficiently heated because vibration is directly applied to the fixing nip 9, but the transfer paper S vibrates slightly at a high frequency. The vibration propagation preventing member 204 cannot suppress vibration of the transfer sheet S even if propagation of vibration of the fixing belt 2 is prevented. When the transfer paper S vibrates, there is a problem in that toner scattering cannot be prevented by using a rubber layer as the surface layer of the fixing belt 2 or applying silicone oil to the surface of the fixing belt 2.

  In contrast, the fixing device 100 to which the present invention shown in FIGS. 1 and 5 is applied includes a vibrator 1 that applies vibration to the fixing belt 2 at a position different from the fixing nip 9. Since the vibration is applied to the fixing belt 2 at a position different from the fixing nip 9, the vibration is transmitted in the thickness direction of the fixing belt 2 and the transfer sheet S is not vibrated. Further, since the vibration absorbing member 4 is disposed between the vibrator 1 and the fixing nip 9, it is possible to suppress the vibration from being transmitted to the fixing nip 9 by transmitting the vibration in the conveying direction of the fixing belt 2. For this reason, it is possible to suppress toner scattering caused by vibration of the transfer sheet S passing through the fixing nip 9.

[Modification]
FIG. 6 is an explanatory diagram of a fixing device 100 according to a modification.
The fixing device 100 of the modification shown in FIG. 6 is shown in FIG. 1 in that the vibration absorbing member 4 is arranged not only on the downstream side in the moving direction of the fixing belt 2 but also on the upstream side with respect to the vibration applying unit 109. Different from the fixing device 100 of the first embodiment. Since other points are common, description of common points is omitted.

  The modification fixing device 100 includes, as the vibration absorbing member 4, a vibration applying unit downstream vibration absorbing member 4 c and a vibration applying unit upstream vibration absorbing member 4 d. The vibration applying member downstream side vibration absorbing member 4 c is disposed at a position downstream of the vibration applying unit 109 and upstream of the fixing nip 9 in the moving direction of the fixing belt 2. Further, the vibration imparting portion upstream side vibration absorbing member 4 d is disposed at a position downstream of the fixing nip 9 and upstream of the vibration imparting portion 109.

As described above, since the vibration transmission speed is faster than the movement speed of the fixing belt 2, the vibration is also transmitted to the vibration applying unit 109 toward the upstream side in the movement direction of the fixing belt 2. Such a transmission path is susceptible to vibration attenuation. However, by arranging the vibration imparting portion upstream side vibration absorbing member 4d in this transmission path, it is possible to more reliably prevent vibration from being transmitted to the fixing nip 9.
The two vibration absorbing members 4 (4c and 4d) provided in the fixing device 100 of the modification shown in FIG. 6 may be a roller pair as in the fixing device 100 of the second embodiment.

[Experimental example 2]
Hereinafter, experimental examples using the fixing device 100 to which the present invention is applied will be described. A specific configuration example of the fixing device 100 will be described as each example, but the present invention is not limited to the following example.

[Example 1]
<Creation of unfixed toner image>
As the image forming apparatus, an unfixed toner image creating apparatus obtained by modifying Imagio MP C3300 (Ricoh MFP) was used. Using this apparatus, an unfixed solid monochrome image of 20 [mm] × 20 [mm] was formed on MyPaper (manufactured by Ricoh) as transfer paper S using spot toner black C3300 (manufactured by Ricoh). The formed unfixed toner image area was cut into 50 [mm] × 100 [mm] so that it was in the center, and used for the subsequent experiments.

<Fixing experiment>
In Example 1, a fixing experiment was performed using the fixing device 100 of Embodiment 1 described above.
The first stretching roller 5, the second stretching roller 6 and the pressure roller 3 have a thickness of 2 [mm] on the surface of a SUS roller having a diameter of 50 [mm] and an axial length of 100 [mm]. Those having a silicone rubber layer were used.

For the vibrator 1, an ultrasonic welder (SONOSCO 325D manufactured by Seidensha) having an output of 300 [W] and a vibration frequency of 28.5 [kHz] was used as a vibrator. Further, an aluminum alloy plate horn having a tip portion of 40 [mm] in length, 40 [mm] in width, and 10 [mm] in thickness as the horn member 101 was attached to this vibrator.
As the fixing belt 2, an endless belt made of polyimide was used. As the vibration absorbing member 4, λGEL (trade name: Taika Co., Ltd.) is used, and contacts the back surface of the fixing belt 2 at a position 3 [cm] upstream of the fixing nip 9 in the surface movement direction of the fixing belt 2. Arranged to be.

  In a state where the fixing belt 2 and the pressure roller 3 are rotated so that the transfer speed of the transfer sheet S is 100 [mm / s], the vibrator is vibrated with the set output 40 [%], and is fed to the fixing nip 9. The transfer sheet S on which an unfixed toner image was formed was inserted and a fixing operation was performed.

<Image disturbance evaluation>
Density unevenness of the fixed toner image (solid image) was measured with a reflection densitometer X-Rite 939 (manufactured by X-Rite Co., Ltd.) and evaluated according to the following evaluation criteria.
〔Evaluation criteria〕
“◎”: Density unevenness is less than 10% “◯”: Density unevenness is 10 “%” or more and less than 15 [%] “Δ”: Density unevenness is 15 “%” or more and less than 20 [%] “×” ": Density unevenness is 20% or more"

[Example 2]
A fixing experiment was performed under the same conditions as in Example 1 except that the fixing device 100 of Embodiment 2 described above was used. The vibration absorbing member 4 including the roller pair provided in the fixing device 100 according to the second embodiment has a thickness of 2 [mm] on the surface of a SUS roller having a diameter of 10 [mm] and an axial length of 100 [mm]. A λGEL sheet layer was used.

[Comparative Example 1]
A fixing experiment was performed under the same conditions as in Example 1 except that a fixing device in which the vibration absorbing member 4 was removed from the fixing device 100 shown in FIG. 1 was used as the fixing device.

[Comparative Example 2]
As the fixing device, the vibration absorbing member 4 is removed from the fixing device 100 shown in FIG. 1, and a fixing device that applies silicone oil to the surface of the fixing belt 2 is used as a measure for preventing toner scattering. The fixing experiment was conducted under the conditions.

A list of results of Experimental Example 2 is shown in Table 1.

As shown in Table 1, in Examples 1 and 2 to which the present invention was applied, vibration transmission to unfixed toner was suppressed, and the image was prevented from being disturbed.
Therefore, in the fixing device 100 to which the present invention is applied, vibration transmission to the unfixed toner on the recording medium is suppressed while preventing the occurrence of image disturbance while realizing fixing without a heater using ultrasonic vibration. I was able to.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
The fixing belt such as the fixing belt 2 that moves endlessly, the pressure member such as the pressure roller 3 that forms a fixing nip such as the fixing nip 9 in contact with the surface of the fixing belt, and the fixing belt at a position other than the fixing nip. In a fixing device such as the fixing device 100 having a vibrating member such as the vibrator 1 that vibrates in contact with the fixing belt, in the moving direction of the fixing belt, the vibration applying unit such as the vibration applying unit 109 that contacts the vibrating member to the fixing nip. The distance is equal to or less than the distance from the fixing nip to the vibration applying portion, and a vibration absorbing member such as the vibration absorbing member 4 that contacts the fixing belt and absorbs vibration is disposed downstream of the vibration applying portion in the moving direction of the fixing belt. And on the upstream side of the fixing nip.
According to this, as described in the above embodiment, the vibration member contacts the fixing belt at a position other than the fixing nip and vibrates, and the vibration energy is converted into heat energy to heat the fixing belt. The heated fixing belt portion reaches the fixing nip by endless movement, and the heat of the fixing belt is transmitted to the toner at the fixing nip, whereby heat fixing can be performed.
Further, in this aspect, since the vibration member comes into contact with the fixing belt and vibrates at a position other than the fixing nip, it is possible to prevent the vibration of the vibration member from being transmitted in the thickness direction of the fixing belt and reaching the fixing nip.
In the vibration applying unit, a part of the vibration energy is converted into heat energy, and the vibration energy that is not converted into heat energy causes the fixing belt to vibrate. The vibration transmitted from the vibration applying portion toward the upstream side in the moving direction of the fixing belt is likely to be attenuated because the moving direction of the fixing belt and the transmitting direction of the vibration are opposite to each other. On the other hand, the vibration transmitted from the vibration applying unit toward the downstream side in the moving direction of the fixing belt is less likely to be attenuated because the moving direction of the fixing belt coincides with the transmitting direction of vibration. For this reason, in the movement direction of the fixing belt, when the distance from the vibration applying unit to the fixing nip is equal to or less than the distance from the fixing nip to the vibration applying unit, the moving direction of the fixing belt from the vibration applying unit. The vibration transmitted toward the downstream side of the toner is less attenuated until it reaches the fixing nip, and is more likely to affect the vibration in the fixing nip.
In this aspect, vibration energy of vibration transmitted from the vibration applying unit toward the downstream side in the moving direction of the fixing belt is absorbed by the vibration absorbing member. For this reason, it is possible to suppress the vibration of the vibration member from being transmitted in the fixing belt conveyance direction and reaching the fixing nip.
Thus, in this aspect, transmission of vibration in the thickness direction of the fixing belt can be prevented and transmission of vibration in the conveyance direction of the fixing belt can be suppressed, so that it is possible to suppress vibration energy from reaching the fixing nip. For this reason, it is possible to suppress vibrations from being transmitted to the recording medium partially reaching the fixing nip, and to suppress the unfixed toner image on the recording medium from being disturbed due to the vibration of the vibration member. Therefore, the configuration including the vibrating member that vibrates in contact with the fixing belt at a position other than the fixing nip can suppress the occurrence of the disturbance of the toner image on the recording medium that partially reaches the fixing nip.
Furthermore, in this aspect, the vibration energy transmitted to the fixing belt without being converted into heat energy by the vibration applying unit is absorbed by the vibration absorbing member disposed on the downstream side in the moving direction of the fixing belt with respect to the vibration applying unit. The As found by the present inventors, the vibration absorbing member generates heat when absorbing vibration, converts the vibration energy into heat energy, and heats the fixing belt. By further heating the fixing belt heated by the vibration applying unit at a position where the vibration absorbing member comes into contact, the fixing belt can be heated more efficiently than in a configuration without the vibration absorbing member.
(Aspect B)
A fixing belt such as the fixing belt 2 that moves endlessly, a pressure member such as a pressure roller 3 that forms a fixing nip such as a fixing nip 9 in contact with the surface of the fixing belt, and the fixing belt at a position other than the fixing nip. In a fixing device such as the fixing device 100 having a vibrating member such as the vibrator 1 that vibrates in contact with the vibration, the vibration absorbing member 4c on the downstream side of the vibration applying unit that absorbs vibration by contacting the fixing belt and the upstream side of the vibration applying unit The vibration absorbing member such as the vibration absorbing member 4d is fixed to the position downstream of the vibration applying unit such as the vibration applying unit 109 and the upstream side of the fixing nip in the moving direction of the fixing belt. It arrange | positions in each of the position downstream from a nip and the upstream from a vibration provision part.
According to this, as described in the above embodiment, the vibration member contacts the fixing belt at a position other than the fixing nip and vibrates, and the vibration energy is converted into heat energy to heat the fixing belt. The heated fixing belt portion reaches the fixing nip by endless movement, and the heat of the fixing belt is transmitted to the toner at the fixing nip, whereby heat fixing can be performed.
Further, in this aspect, since the vibration member comes into contact with the fixing belt and vibrates at the vibration applying portion other than the fixing nip, the vibration of the vibration member is transmitted in the thickness direction of the fixing belt and reaches the fixing nip. Can be prevented.
In the vibration applying unit, a part of the vibration energy is converted into heat energy, and the vibration energy that is not converted into heat energy causes the fixing belt to vibrate.
In this aspect, the vibration energy of both the vibration transmitted from the vibration applying unit toward the upstream side and the vibration transmitted from the vibration applying unit toward the downstream side are the vibration applying unit downstream vibration absorbing member 4c and the vibration applying unit. Is absorbed by a vibration absorbing member such as the vibration absorbing member 4d. For this reason, it can suppress more reliably that the vibration of a vibration member is transmitted to the conveyance direction of a fixing belt, and reaches | attains a fixing nip.
Thus, in this aspect, transmission of vibration in the thickness direction of the fixing belt can be prevented and transmission of vibration in the conveyance direction of the fixing belt can be suppressed, so that it is possible to suppress vibration energy from reaching the fixing nip. For this reason, it is possible to suppress vibrations from being transmitted to the recording medium partially reaching the fixing nip, and to suppress the unfixed toner image on the recording medium from being disturbed due to the vibration of the vibration member. Therefore, the configuration including the vibrating member that vibrates in contact with the fixing belt at a position other than the fixing nip can suppress the occurrence of the disturbance of the toner image on the recording medium that partially reaches the fixing nip.
Further, in this aspect, the vibration energy that is not converted into heat energy by the vibration applying unit and is transmitted to the fixing belt is vibrations disposed on the downstream side and the upstream side in the moving direction of the fixing belt relative to the vibration applying unit. Absorbed by the absorbent member. As found by the present inventors, the vibration absorbing member generates heat when absorbing vibration, converts the vibration energy into heat energy, and heats the fixing belt. By further heating the fixing belt heated by the vibration applying unit at a position where the vibration absorbing member comes into contact, the fixing belt can be heated more efficiently than in a configuration without the vibration absorbing member.
(Aspect C)
In the aspect A or B, the vibration absorbing member such as the vibration absorbing member 4 is disposed in the vicinity of the fixing nip such as the fixing nip 9.
According to this, as described in the above embodiment, it is possible to prevent the heat generated by being converted into thermal energy by the vibration absorbing member from being dissipated before reaching the fixing nip.
(Aspect D)
Toner image forming means such as a printer unit 150 that forms a toner image on a recording medium such as transfer paper S using toner, and the surface of the toner image carrier that carries the toner image transferred to the recording medium, or the toner image Image forming apparatus such as a copier 500 provided with fixing means such as a fixing device 100 that heats the surface of the recording medium carrying the toner and softens or melts the toner when the toner image is formed and fixes the toner image on the recording medium. The fixing device according to any one of aspects A to C is used as a fixing unit.
According to this, as described in the above embodiment, the image quality can be reduced because the toner image disturbance caused by the vibration can be suppressed with the configuration including the fixing device that converts the vibration energy of the vibration member into the heat energy. Can be improved.
(Aspect E)
In a fixing method in which a toner image formed on a recording medium such as a transfer sheet S using toner is fixed on the recording medium, a fixing nip such as a fixing nip 9 is formed at an abutting portion with a pressure member to endlessly. A vibration applying step for applying vibration to the moving fixing belt such as the fixing belt 2 at a position other than the fixing nip by the vibration member, and a position downstream of the fixing belt in the moving direction with respect to the position to which the vibration is applied by the vibration applying step. Vibration absorption process that absorbs the vibration of the fixing belt at the position on the side, heat generation process that converts the vibration energy absorbed in the vibration absorption process into thermal energy, and gives the heat energy to the fixing belt, and vibration in the vibration absorption process The fixing belt comes into contact with the recording medium at the fixing nip on the downstream side in the moving direction of the fixing belt with respect to the position where the heat energy is applied in the heat generation process. By applying energy to a recording medium, and the toner for forming a toner image on the recording medium softened or melted, and a recording medium heat application step of fixing on the recording medium.
According to this, as described in the above embodiment, the vibration is applied to the fixing belt in the vibration applying step, so that the vibration energy of the vibration is converted into heat energy, and the fixing belt is heated. The heated fixing belt portion reaches the fixing nip by endless movement, and heat of the fixing belt is transmitted to the toner at the fixing nip, so that heat fixing can be performed in the recording medium heat applying step.
Further, in this aspect, since the vibration member comes into contact with the fixing belt and vibrates at a position other than the fixing nip, it is possible to prevent the vibration of the vibration member from being transmitted in the thickness direction of the fixing belt and reaching the fixing nip.
In the vibration applying step, part of the vibration energy is converted into thermal energy, and the vibration energy that has not been converted into heat energy vibrates the fixing belt, but this vibration energy is absorbed in the vibration absorption step. For this reason, it is possible to suppress the vibration of the vibration member from being transmitted in the conveying direction of the fixing belt and reaching the fixing nip.
Thus, in this aspect, transmission of vibration in the thickness direction of the fixing belt can be prevented and transmission of vibration in the conveyance direction of the fixing belt can be suppressed, so that it is possible to suppress vibration energy from reaching the fixing nip. For this reason, vibration can be suppressed from being transmitted to the recording medium partially reaching the fixing nip at the fixing nip in the recording medium heat application process, and the unfixed toner image on the recording medium is applied in the vibration process. Can be prevented from being disturbed. Therefore, the configuration including the vibrating member that vibrates in contact with the fixing belt at a position other than the fixing nip can suppress the occurrence of the disturbance of the toner image on the recording medium that partially reaches the fixing nip.
Furthermore, in this aspect, the vibration energy transmitted to the fixing belt without being converted into heat energy in the vibration applying step is absorbed in the vibration absorbing step at a position downstream of the fixing belt in the moving direction with respect to the vibration applying unit. The In the vibration absorbing process, as found by the present inventors, when absorbing vibration, the vibration energy is converted into heat energy to generate heat, and in the heat generating process, the fixing belt is heated. By further heating the fixing belt heated in the vibration applying step in the heat generation step, the fixing belt can be heated more efficiently than in a fixing method that does not include the vibration absorption step and the heat generation step.

DESCRIPTION OF SYMBOLS 1 Vibrator 2 Fixing belt 3 Pressure roller 4 Vibration absorbing member 4a First vibration absorbing member 4b Second vibration absorbing member 4c Vibration applying part downstream vibration absorbing member 4d Vibration applying part upstream vibration absorbing member 5 First stretching roller 6 Second tension roller 7 Unfixed toner 8 Fixing toner 9 Fixing nip 10 Photoconductor 14 Belt drive roller 15 Cleaning facing roller 16 Secondary transfer facing roller 17 Intermediate transfer belt cleaning device 18 Image forming unit 21 Exposure device 22 Secondary transfer Device 23 Transfer conveyance support roller 24 Transfer conveyance belt 28 Reverse device 32 Contact glass 33 First traveling body 34 Second traveling body 35 Imaging lens 36 Reading sensor 49 Registration roller 50 Intermediate transfer belt 51 Manual feed roller 52 Manual separation roller 53 Manual feed path 54 Manual tray 55 Switching claw 56 Carrying after fixing Feed roller pair 57 Discharge tray 61 Developing device 62 Primary transfer roller 63 Photoconductor cleaning device 64 Static elimination device 65 Developing sleeve 66 Stirring unit 67 Developing unit 68 Conveying screw 70 Developing case 71 Toner density sensor 72 Magnet roller 73 Doctor blade 75 Cleaning blade 76 Fur brush 77 Electric field roller 78 Scraper 79 Recovery screw 80 Toner recycling device 100 Fixing device 101 Horn member 120 Tandem type image forming unit 130 Document table 142 Paper feed roller 143 Paper bank 144 Paper feed cassette 145 Separation roller 146 Paper feed path 147 Conveyance Roller 148 Main body side paper feed path 150 Printer unit 156 Discharge roller pair 160 Charging device 200 Paper feed device 201 Belt member 202 Base 204 Vibration propagation preventing member 210 La 211 guide rollers 212 drive roller 300 scanner 400 automatic document feeder 500 copier H1 first heating portion H2 second heating unit L exposure light S transfer sheet

JP-A-4-195179 JP 2002-229358 A JP 2012-022016 JP JP 2001-255767 A

Claims (5)

An endlessly moving heat fixing belt,
A pressure member that contacts the surface of the fixing belt to form a fixing nip;
A fixing device having a vibration member that vibrates in contact with the fixing belt at a position other than the fixing nip;
In the moving direction of the fixing belt, the distance from the vibration applying portion where the vibrating member contacts the fixing belt to the fixing nip is equal to or less than the distance from the fixing nip to the vibration applying portion.
A vibration absorbing member that contacts the fixing belt and absorbs vibration is disposed at a position downstream of the vibration applying unit and upstream of the fixing nip in the moving direction of the fixing belt. Fixing device to do. A fixing belt that moves endlessly;
A pressure member that contacts the surface of the fixing belt to form a fixing nip;
A fixing device having a vibration member that vibrates in contact with the fixing belt at a position other than the fixing nip;
A vibration absorbing member that contacts the fixing belt and absorbs vibration is positioned downstream of the vibration applying portion in contact with the vibration member and upstream of the fixing nip in the moving direction of the fixing belt. ,
A fixing device, which is disposed at a position downstream of the fixing nip and upstream of the vibration applying unit. The fixing device according to claim 1 or 2,
A fixing device, wherein the vibration absorbing member is disposed in the vicinity of the fixing nip. Toner image forming means for forming a toner image on a recording medium using toner;
When the surface of the toner image carrier that carries the toner image to be transferred to the recording medium or the surface of the recording medium that carries the toner image is heated and the toner image is formed, the toner is softened or melted, An image forming apparatus including a fixing unit that fixes a toner image,
An image forming apparatus using the fixing device according to claim 1 as the fixing unit. In a fixing method for fixing a toner image formed on a recording medium using toner to the recording medium,
A vibration applying step of applying vibration to a fixing belt that moves endlessly by forming a fixing nip at a contact portion with a pressure member at a position other than the fixing nip by a vibration member;
A vibration absorbing step in which vibration of the fixing belt is absorbed by a vibration absorbing member at a position downstream of the moving direction of the fixing belt with respect to a position to which vibration is applied by the vibration applying step;
Converting the vibration energy of the vibration absorbed in the vibration absorption step into heat energy, and applying the heat energy to the fixing belt;
The fixing belt comes into contact with the recording medium at a fixing nip on the downstream side in the moving direction of the fixing belt with respect to a position where vibration is absorbed in the vibration absorbing step and thermal energy is applied in the heat generating step. A recording medium heat application step of softening or melting the toner that forms the toner image on the recording medium by applying the thermal energy of the belt to the recording medium and fixing the toner on the recording medium. Fixing method to do.