JP2006267177A - Sheet cooling transport device and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet cooling transport device capable of cooling a sheet by efficiently discharging heat of the sheet after fixation, and transporting the sheet without causing complication or size increase of the transport device by simple structure and an image forming apparatus using the same. <P>SOLUTION: The sheet cooling transport device is provided with: an endless belt 61, a rotary member 62 which is arranged opposite to the endless belt 61; and a highly thermal conductive fixed slide member 64 which is arranged at a position opposite to the rotary member 62 in the endless belt 61 and forms a nip part 63 for cooling at a pressure contact part between the endless belt 61 and the rotary member 62 by pressure-contacting the endless belt 61 with the rotary member 62, and the sheet cooling transport device transports the sheet 33 so that a fixed image surface of the sheet 33 contacts one of a body of rotation or the endless belt 61. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet cooling / conveying device used in an image forming apparatus such as a printer, a copying machine, or a facsimile and an image forming apparatus using the same, and more particularly to a sheet cooling / conveying method that cools and conveys a sheet heated and fixed by an image fixing device. The present invention relates to an apparatus and an image forming apparatus using the same.

JP 2003-233227 A JP-A-4-260065

  Conventionally, as an image fixing apparatus used in this type of image forming apparatus such as a printer, a copying machine, or a facsimile, for example, an apparatus disclosed in Japanese Patent Application Laid-Open No. 2003-233227 has already been proposed. An image forming apparatus according to Japanese Patent Laid-Open No. 2003-233227 includes a latent image carrier that carries a latent image, a developing unit that visualizes the latent image on the latent image carrier as a developer image, and the developer image. In an image forming apparatus comprising: a transfer unit that transfers an unfixed image to a recording material; and a fixing unit that fixes the unfixed image to the recording material by heating the recording material. A conveying member that is a pair of rotating bodies that press and contact each other in the recording material conveying path to form a conveying nip region and rotate to sandwich and convey the recording material in the conveying nip region, and one rotating member of the conveying member A heat conductive member that conducts heat directly or indirectly and rotates at a predetermined position around an axis substantially parallel to the axis of the one rotating body, wherein the one rotating body is a cored bar. And covering the outer peripheral surface of the cored bar It is configured to have a high thermal conductive layer formed by coating the outer peripheral surface of the formed elastic layer and elastic layer is.

  Such an image forming apparatus is capable of forming a nip by nipping and conveying a pair of rotating bodies composed of an endothermic roll having an elastic layer and a heat pipe by pressing each other, and cooling can be performed at the nip portion. It was.

  Further, in order to increase the cooling effect in the image forming apparatus, it is necessary to widen the nip portion. However, in the apparatus that is nipped and conveyed by the pair of rotating bodies described above, the nip width cannot be widened, and the nip portion In order to widen the width, it is necessary to set the diameter of the conveyance roll made of an elastic layer to be large, or to set the pressing load high to deform the elastic layer of the conveyance roll.

  In view of this, a technique disclosed in Japanese Patent Laid-Open No. 4-260065 has already been proposed as a technique that makes it possible to increase the nip width. In such a recording sheet cooling apparatus according to Japanese Patent Laid-Open No. 4-260065, at least one roll is sandwiched and conveyed by pressing an endless belt stretched by a roll made of a heat pipe against a rotating body having an elastic layer. A nip portion is formed, and the nip portion can be efficiently cooled.

  However, the conventional technique has the following problems. That is, in the case of the recording sheet cooling apparatus according to the above Japanese Patent Laid-Open No. 4-260065, it is configured to sandwich and convey the stretched endless belt against the rotating body having the elastic layer. Compared to the method of nipping and transporting with a pair of rotating bodies, the nip width is wider and the cooling efficiency can be improved, but since the endless belt is stretched, the belt moves in the axial direction of the stretch roll It is necessary to control the so-called “walk”, and in order to prevent the endless belt from walking, a sensor for detecting the walk of the endless belt and a mechanism for swinging the stretching roll are required. There was a problem of incurring an increase in size.

  Accordingly, the present invention has been made to solve the above-described problems of the prior art, and the object of the present invention is to make the apparatus simple and without causing complication of the apparatus or enlargement of the apparatus. Another object of the present invention is to provide a sheet cooling / conveying apparatus capable of efficiently discharging, cooling, and conveying the heat of the sheet after fixing, and an image forming apparatus using the same.

In order to achieve the above object, an invention described in claim 1 is provided in an endless belt, a rotating member disposed to face the endless belt, and a position facing the rotating member in the endless belt, A high thermal conductivity fixed sliding member that forms a nip portion for cooling at the pressure contact portion between the endless belt and the rotating member by pressing the endless belt to the rotating member;
The sheet cooling and conveying apparatus is characterized in that the sheet is conveyed so that the fixed image surface of the sheet is in contact with either the rotating body or the endless belt.

The invention described in claim 2 is the sheet cooling and conveying apparatus according to claim 1,
In the sheet cooling and conveying apparatus, the endless belt is made of a metal material.

Furthermore, the invention described in claim 3 is the sheet cooling and conveying apparatus according to claim 1,
In the sheet cooling and conveying apparatus, a lubricant is applied to an inner peripheral surface of the endless belt.

The invention described in claim 4 is the sheet cooling and conveying apparatus according to claim 1,
The rotating member is a sheet cooling / conveying device formed by covering the outer peripheral surface of an elastic layer coated on the surface of a cored bar member with a high thermal conductive layer.

Furthermore, the invention described in claim 5 is the sheet cooling and conveying apparatus according to claim 1,
The rotating member is a sheet cooling / conveying device formed by covering an outer peripheral surface of an elastic layer coated on a surface of a cored bar member with a highly releasable layer.

The invention described in claim 6 is the sheet cooling and conveying apparatus according to claim 1,
The fixed sliding member is a sheet cooling / conveying device having a cooling means at an end portion in an axial direction thereof.

  Further, the invention described in claim 7 is an image forming apparatus characterized in that the sheet cooling and conveying apparatus according to any one of claims 1 to 6 is arranged on the downstream side of the fixing unit in the sheet conveying direction. is there.

  In the present invention, the fixed sliding member disposed on the inner surface of the endless member is pressed by the rotating body having the elastic layer via the endless belt, so that the nip width between the endless belt and the rotating body can be increased. In addition, since the endless belt is not stretched by a roll or the like, it is possible to prevent complication of the apparatus due to belt walk control or the like. In addition, since the fixed image on the sheet is conveyed while being in contact with the rotating body toward the rotating body having the elastic layer, the image surface can be prevented from being disturbed. By using an endless belt made of metal, the heat of the sheet after fixing can be transferred. Further, by applying a lubricant to the inner peripheral surface of the endless belt, sliding friction between the endless belt and the fixed sliding member can be reduced, and various problems due to friction can be suppressed.

  Further, in the rotating member, by having the high thermal conductive layer on the outer peripheral surface of the elastic layer, the heat of the sheet after fixing can be transferred also from the fixed image surface, and the sheet can be cooled more effectively. it can. In addition, by having a highly releasable layer on the outer peripheral surface of the elastic layer, it is possible to prevent the rotating member from being soiled, and to prevent image disturbance due to the surface of the rotating member coming into contact with the fixed image surface. .

  According to the present invention, the sheet cooling that can efficiently discharge, cool, and convey the heat of the sheet after fixing with a simple configuration without incurring the complexity of the apparatus or the enlargement of the apparatus. A conveyance device and an image forming apparatus using the same can be provided.

  Embodiments of the present invention will be described below with reference to the drawings.

Embodiment 1
FIG. 2 is a schematic configuration diagram showing a tandem type color electrophotographic copying machine as an image forming apparatus to which the sheet cooling and conveying apparatus according to the first embodiment of the present invention is applied. Although this tandem type color electrophotographic copying machine is provided with an image reading device, the image forming device is not provided with an image reading device, and is based on image data output from a personal computer (not shown). Of course, a color printer, a facsimile, or the like that forms an image may be used.

  In FIG. 2, reference numeral 1 denotes a main body of a tandem type color electrophotographic copying machine. The color electrophotographic copying machine main body 1 has an image reading device (IIT) for reading an image of a document 2 at an upper portion on one end side thereof. : ImageInputTerminal) 4, and the image data output from the image reading device 4 or a personal computer (not shown), or the like is sent to the inside of the color electrophotographic copying machine main body 1 via a telephone line or a LAN. An image processing apparatus (IPS: Image Processing System) 12 that performs predetermined image processing on the received image data, and an image output apparatus that outputs an image based on the image data that has been subjected to predetermined image processing by the image processing apparatus 12 (IOT: ImageOutputTerminal) 100 There.

  In the image reading device 4, an image of the original 2 pressed on the platen glass 5 by the platen cover 3 or an original conveyed automatically by an ADF (not shown) is read. The image reading device 4 illuminates a document 2 placed on a platen glass 5 with a light source 6, and reflects a reflected light image from the document 2 from a full-rate mirror 7, half-rate mirrors 8 and 9, and an imaging lens 10. The image reading element 11 composed of a CCD or the like is scanned and exposed through a reduction optical system, and the color material reflected light image of the document 2 is formed at a predetermined dot density (for example, 16 dots / mm) by the image reading element 11. It is configured to read.

  The color material reflected light image of the document 2 read by the image reading device 4 is subjected to image processing as, for example, document reflectance data of three colors of red (R), green (G), and blue (B) (8 bits each). The image processing apparatus 12 sends a predetermined correction such as shading correction, position shift correction, brightness / color space conversion, gamma correction, frame erasing, color / moving editing, etc., to the reflectance data of the document 2. Image processing is performed.

  The image data that has been subjected to the predetermined image processing by the image processing apparatus 12 as described above is a four-color document of yellow (Y), magenta (M), cyan (C), and black (K) (each 8 bits). Converted to color material gradation data (raster data), as will be described below, yellow (Y), magenta (M), cyan (C), and black (K) image forming units 13Y, 13M, 13C, 13K laser writing devices 14Y, 14M, 14C, and 14K, and these laser writing devices 14Y, 14M, 14C, and 14K perform image exposure with laser light LB in accordance with original color material gradation data of a predetermined color. Done.

  By the way, inside the tandem type color electrophotographic copying machine main body 1, as described above, four image forming units 13Y of yellow (Y), magenta (M), cyan (C), and black (K), 13M, 13C, and 13K are arranged in parallel at regular intervals in the horizontal direction.

  These four image forming units 13Y, 13M, 13C, and 13K are all configured in the same manner, and roughly divided, a photosensitive drum as a latent image carrier that is rotationally driven at a predetermined speed along the arrow A direction. 15, a scorotron 16 for primary charging as charging means for uniformly charging the surface of the photosensitive drum 15, and a laser beam corresponding to the image information of each color on the surface of the photosensitive drum 15 by scanning exposure. The image forming apparatus (image forming means) includes a laser writing device 14 that forms an electrostatic latent image, a developing device 17 that develops the electrostatic latent image formed on the photosensitive drum 15, a cleaning device 18, and the like. ing.

  As shown in FIG. 2, the laser writing device 14 modulates the semiconductor laser 19 according to the original color material gradation data, and emits a laser beam LB from the semiconductor laser 19 according to the gradation data. The laser beam LB emitted from the semiconductor laser 19 is deflected and scanned by the rotary polygon mirror 22 via the reflection mirrors 20 and 21, and again carries an image via the reflection mirrors 20 and 21 and the plurality of reflection mirrors 23 and 24. Scanning exposure is performed on the photosensitive drum 15 as a body.

  From the image processing device 12, the laser writing devices 14Y, 14M, 14C of the image forming units 13Y, 13M, 13C, and 13K for each color of yellow (Y), magenta (M), cyan (C), and black (K) are provided. Image data (raster data) of each color is sequentially output to 14K, and laser beams LB emitted according to the image data from these laser writing devices 14Y, 14M, 14C, and 14K are supplied to the respective photosensitive drums 15Y, 15M, The surfaces of 15C and 15K are scanned and exposed to form an electrostatic latent image. The electrostatic latent images formed on the photosensitive drums 15Y, 15M, 15C, and 15K are respectively yellow (Y), magenta (M), and cyan (C) by the corresponding developing devices 17Y, 17M, 17C, and 17K. , And developed as a toner image of each color of black (K).

  Yellow (Y), magenta (M), cyan (C), and black (K) sequentially formed on the photosensitive drums 15Y, 15M, 15C, and 15K of the image forming units 13Y, 13M, 13C, and 13K. The unfixed toner images of the respective colors are superimposed on the surface of the intermediate transfer belt 25 at a primary transfer position where the photosensitive drums 15Y, 15M, 15C, and 15K are in contact with the intermediate transfer belt 25 as an intermediate transfer member. Sequentially transferred. Semiconductive bias rolls 26Y, 26M, 26C, and 26K are disposed on the back surface side of the intermediate transfer belt 25 at the primary transfer position, and the intermediate transfer belt is provided by these bias rolls 26Y, 26M, 26C, and 26K. 25 abuts on the surfaces of the photosensitive drums 15Y, 15M, 15C, and 15K. The primary transfer bias rolls 26Y, 26M, 26C, and 26K are applied with a voltage having a polarity opposite to the charging polarity of the toner, and the respective colors formed on the photosensitive drums 15Y, 15M, 15C, and 15K are undetermined. The contact toner images are sequentially electrostatically attracted onto the intermediate transfer belt 25 to form a full-color image.

  The intermediate transfer belt 25 is fixed between a driving roll 27, a driven roll 28, a tension roll 29, an opposing roll (backup roll) 30 for secondary transfer, a driven roll 31, and an idle roll 32. The drive roll 27 is stretched by a tension roller and is rotated by a dedicated drive motor (not shown) having excellent constant speed, and is circulated at a predetermined speed in the direction of arrow B.

  When a single color image is formed, only the desired color image forming units 13Y, 13M, 13C, and 13K are operated, and a desired single color unfixed toner image is formed on the intermediate transfer belt.

  In this way, the unfixed toner images of the respective colors of yellow (Y), magenta (M), cyan (C), and black (K) that have been primary-transferred multiple times on the intermediate transfer belt 25 are intermediate transfer belt 25. Is rotated to the secondary transfer position facing the conveyance path of the recording paper 33 (sheet), and an unfixed toner image is transferred from the intermediate transfer belt 25 to the recording paper 33 at the secondary transfer position. Transcribed. The recording paper 33 is fed from the print paper tray 34 by the feed roller 35, transported to the registration roller 38 by a paper transport path 37 having a plurality of transport rollers 36, and temporarily stopped. Next, the recording paper 33 is conveyed by the registration roller 38 at a predetermined timing, and is sandwiched between the secondary transfer bias roll 39 and the intermediate transfer belt 25. Further, on the back side of the intermediate transfer belt 25 at the secondary transfer position, a backup roll 30 that is opposed to the bias roll 39 and a metal roll 41 that contacts the backup roll 30 are disposed. At the secondary transfer position, by applying a voltage (normal transfer bias) having the same polarity as the toner charging polarity to the metal roll 41, the bias roll 39 forms a transfer electric field as a counter electrode, and an intermediate transfer belt. The unfixed toner image carried on 25 is electrostatically transferred to the recording paper 33 at the secondary transfer position. The secondary transfer bias roll 39 is cleaned by a brush roll 42.

  The recording sheet 33 on which the unfixed toner image is transferred is discharged from the intermediate transfer belt 25 while being discharged by a flat plate discharging device 43, and then is used as a double transfer material transporting unit via the chute 44. Are fed to the fixing device 47 by the paper transport belts 45 and 46, and the fixing process of the unfixed toner image is performed. The paper transport belts 45 and 46 are composed of an endless rubber belt 45c stretched between a driving roller 45a and a driven roller 45b, and five rubber belts are stretched in parallel by one paper transport belt. ing.

  The fixing device 47 includes a pair of fixing rolls (fixing members) including a heating roll 48 having a heater (not shown) therein and a pressure roll 49 disposed in pressure contact with the heating roll 48. is doing. When the recording paper 33 on which the unfixed toner image is formed passes through the fixing area between the heating roll 48 and the pressure roll 49, the fixing device 47 generates a toner image on the recording paper 33 by heat and pressure. It has become established.

  During the fixing process, the unfixed toner surface of the recording paper 33 is usually in direct contact with the outer peripheral surface of the heating roll 48, so that a part of the unfixed toner on the recording paper 33 is transferred to the heating roll 48 side. A phenomenon (toner offset phenomenon) in which the toner re-transfers to the recording paper 33 after one rotation of the heating roll 48 occurs.

  Therefore, in this embodiment, in order to prevent the toner offset phenomenon, a release agent coating device 50 that applies a release agent to the surface of the heating roll 48 is provided. As shown in FIG. 2, the release agent coating apparatus 50 includes a release agent supply roll 51, a release agent application roll 52, a release agent supply amount regulating blade 53, and a release agent tank 54. The release agent supplied from the release agent tank 54 to the surface of the release agent supply roll 51 is regulated by the release agent supply regulation blade 53, and the release agent supply roll 51 and the release agent application roll. By the contact of 52 and the contact between the release agent coating roll 52 and the heating roll 48, amine oil or silicone oil as a release agent is uniformly applied to the surface of the heating roll 48.

  On the other hand, residual toner is removed from the intermediate transfer belt 25 after the secondary transfer of the unfixed toner image is completed, as shown in FIG. 1, by a belt cleaner 55 positioned downstream of the secondary transfer portion.

  When creating a double-sided print, as shown in FIG. 2, the recording paper 33 does not pass through the fixing device 47 and the first side is fixed, and then is not discharged outside the image forming apparatus. Then, a switching gate 56 disposed on the downstream side of the fixing device 47 switches to the direction of the sheet reversing unit 57 and the double-sided sheet conveying unit 58. In the paper reversing unit 57, the recording paper 33 is reversed by switchback, passes through the paper conveying unit 58, and is conveyed again to the registration roller 38. While the recording paper 33 is conveyed to the registration roller 38, an image for the second surface is formed on the intermediate transfer belt 25 in the same manner as the image forming process for the first surface. The first recording sheet 33 on which the first side is imaged at the timing is conveyed to the secondary transfer unit, and the image is transferred to the second side in the same manner as the first side. Thereafter, the recording paper 33 having the toner image transferred onto the second surface is conveyed to the fixing device 47 by the paper conveying belts 45 and 46, and after fixing processing, is provided outside the image forming apparatus. The sheet is discharged onto the discharge tray 59, and the image forming process for a series of double-sided printing is completed.

As the intermediate transfer belt 25, a synthetic resin such as polyimide or polyamide containing an appropriate amount of an antistatic agent such as carbon black and formed into an endless belt shape is used, and its volume resistivity is 10 ⁶ to 10 ^14. For example, the thickness is set to 0.1 mm.

The primary transfer bias roll 26 is made of foamed urethane rubber in which carbon black is dispersed, and has a volume resistance of 10 ⁶ to 10 ¹⁰ Ω, a roll diameter of φ28 mm, and a hardness of 35 °, for example. (Asuka C) is set.

Further, the bias roll 39 for secondary transfer is made of urethane rubber tube with carbon black dispersed on the surface, the inside is made of foamed urethane rubber with carbon black dispersed, and the roll surface is coated with fluorine, It is formed so that the resistance is 10 ³ to 10 ¹⁰ Ω and the roll diameter is φ28 mm, and the hardness is set to 30 ° (Asuka C), for example. On the other hand, the backup roll 30 is made of EPDM and NBR blend rubber tube with carbon black dispersed in the surface and EPDM rubber inside, and has a surface resistivity of 10 ⁷ to 10 ¹⁰ Ω / □ and a roll diameter. It is formed to have a diameter of 28 mm, and the hardness is set to 70 ° (Asuka C), for example.

  The rubber belts of the paper conveying belts 45 and 46 are made of rubber made of EPDM and are endless, and the thickness of the belt is set to about 1 mm.

  Further, the heating roll 48 and the pressure roll 49 are formed by coating a silicone rubber on the surface of a cylindrical core made of a metal having high thermal conductivity such as aluminum.

  Furthermore, the release agent supply roll 51 and the release agent application roll 52 are composed of silicone rubber rolls. The release agent supply amount regulating blade 53 is made of fluoro rubber.

  By the way, the sheet cooling and conveying apparatus according to the first embodiment is disposed at a position facing the endless belt, the rotating member disposed to face the endless belt, and the rotating member in the endless belt, and the endless belt. And a fixed sliding member with high thermal conductivity that forms a nip portion for cooling at the pressure-contact portion between the endless belt and the rotating member, and the fixing image surface of the sheet is the rotating body or the endless belt. It conveys so that either one may be touched.

  That is, the sheet cooling / conveying device 60 according to this embodiment is disposed in the vicinity of the downstream side of the fixing device 47 in the color electrophotographic copying machine main body 1 as shown in FIG. The tandem type color electrophotographic copying machine is a high-speed machine with a large number of prints per unit time, and the fixed toner image is still completely solidified on the recording paper 33 immediately after passing through the fixing device 47. In particular, in a full color image having a large amount of toner, there is a possibility that a roll mark is attached when it comes into contact with the paper transport roll immediately after fixing.

  Therefore, in this embodiment, the sheet cooling and conveying device 60 is disposed in the vicinity of the downstream side of the fixing device 47. As shown in FIG. 1, the sheet cooling and conveying device 60 is roughly divided into an endless belt 61, a roll-shaped rotating member 62 disposed at a position facing the endless belt 61 (upper part in the illustrated example), The endless belt 61 is disposed at a position facing the rotating member 62, and the endless belt 61 is pressed against the rotating member 62, whereby a cooling nip 63 is formed on the pressing portion between the endless belt 61 and the rotating member 62. And a fixed sliding member 64 having high thermal conductivity.

  The rotating member 62 includes a cored bar 65 made of a metal such as iron, stainless steel, or aluminum, and an elastic layer 66 made of a sponge, silicone rubber, or the like that is coated on the outer periphery of the cored bar 65 relatively thickly. Yes. The elastic layer 66 may be appropriately filled with a filler in order to increase thermal conductivity. Further, the thickness of the elastic layer 66 and the outer diameter of the cored bar 65 are arbitrary, and the cored bar 65 is not limited to the columnar shape, and may be formed in a cylindrical shape.

  In addition, the outermost layer of the rotating member 62 may be configured to cover a high thermal conductive layer 67 having high thermal conductivity such as a metal such as stainless steel, nickel, or deralmine, if necessary. Furthermore, the outer periphery of the elastic layer 66 of the rotating member 62 may be configured to cover a high releasability layer (not shown). As the high releasability layer, a material having excellent releasability is used, and examples of the material having excellent releasability include fluororesin and silicon resin, but the rotating member 62 is a recording as a sheet. Since heat is received from the paper 33 and the temperature becomes relatively high, it is desirable to have heat resistance. As the fluororesin, PFA, PTFE, and as the silicone resin, thermosetting silicone rubber is suitable. These release materials can be coated by spraying or by coating a tubular resin.

  Further, as shown in FIG. 1, the rotating member 62 is driven to rotate at a predetermined speed equal to that of the fixing device 47 along the direction of the arrow by a driving means (not shown).

  As shown in FIG. 1, the sheet cooling / conveying device 60 is nipped and conveyed so that the fixed image T surface of the recording paper 33 is located on the rotating member 62 side, and recording is performed while passing through the cooling nip 63. The sheet 33 is configured to be deprived of heat 2 by the rotating member 62 and the endless belt 61 and cooled.

  The endless belt 61 is not particularly limited as long as it is made of a material having excellent mechanical strength and heat resistance, such as polyimide resin, but particularly heat such as metal such as stainless steel, nickel, or geralumin. It is preferable to use a material having excellent conductivity. The layer structure of the endless belt 62 may be a single layer structure, but a fluororesin made of, for example, PFA, PTFE, FEP or the like is formed by coating a resin as a release layer on the belt surface. A thing may be used.

  A lubricant is applied to the inner peripheral surface of the endless belt 62 by an application member (not shown). As a result, the endless belt 62 and the endless belt 62 are disposed on the inner side of the endless belt 62, contact the rotating member 62 via the endless belt 62, and form a nip portion 63 at the contact portion between the endless belt 61 and the rotating member 62. The sliding friction between the conductive fixed sliding members 64 can be reduced. As this lubricant, for example, silicone oil, fluorine oil, grease, and the like are used. In order to enhance the cooling effect, heat such as silicone oil compound in which silicone oil or the like is blended with powder having high thermal conductivity such as alumina is used. It is desirable to use conductive grease.

  Further, the high thermal conductivity fixed sliding member 64 uses a high thermal conductivity metal material such as stainless steel, Al, Ni, Cu, Zn or the like as a base material 68 singly or as an alloy, and heat pipes 69, 70 or heat sinks. Etc., or a combination thereof, and the shape thereof is arbitrary such as a rectangular shape in cross section, a plate shape, a roll shape, a curved shape created along the rotating member 62, and the width of the nip portion 63 to be formed. It can be set freely. In the illustrated example, two (a plurality of) heat pipes 69 and 70 are arranged inside and above the base material 68. The number of the heat pipes 69 and 70 may be one, or may be three or more.

  Further, as shown in FIG. 3, both end portions in the longitudinal direction of the heat pipes 69 and 70 are configured to protrude in opposite directions from the base material 68, and the protruding portions 69a of the heat pipes 69 and 70 are formed. 70a, a plurality of heat radiation fins 71, 72 are attached. In addition, fans 73 and 74 that blow air toward the radiation fins 71 and 72 are disposed on the projecting portions 69 a and 70 a of the heat pipes 69 and 70. In addition, you may comprise the protrusion parts 69a and 70a of the said heat pipes 69 and 70 so that it may protrude in the same direction and it may blow with the one ventilation fan 73. FIG.

  The high thermal conductivity fixed sliding member 64 is provided with a pressure contact member 75 that presses the endless belt 61 against the rotary member 62 at a position facing the rotary member 62. A material made of silicone rubber or the like fixed on the support plate 76 is used. The pressure contact member 75 may also be configured to be appropriately filled with a filler such as metal powder in order to improve thermal conductivity.

  Further, the high thermal conductivity fixed sliding member 64 is provided with a belt traveling guide 73 provided so that the endless belt 61 rotates smoothly. The belt traveling guide 73 is provided with flange-shaped flange members 74 that restrict the endless belt 61 from being moved at both ends in the axial direction.

  In the above configuration, in the color electrophotographic copying machine to which the sheet cooling and conveying apparatus according to this embodiment is applied, the apparatus is not complicated and the apparatus is not enlarged as follows. With this configuration, it is possible to efficiently release the heat of the sheet after fixing, cool it, and convey it.

  That is, in the color electrophotographic copying machine, as shown in FIG. 2, the image output device 100 provided in the copying machine body 1 causes yellow (Y), magenta (M), cyan (C), black The recording paper 33 on which a full-color image or the like is formed by superimposing the toner images of the respective colors (K) and the full-color unfixed toner image is transferred is heated and fixed by the fixing device 47 and discharged onto the discharge tray 59. Or the paper is transported to the double-sided paper transport paths 57 and 58.

  Incidentally, in the vicinity of the downstream side of the fixing device 47, as shown in FIG. As shown in FIG. 1, the sheet cooling / conveying device 60 has an endless belt 61 that is in pressure contact with the rotating member 62. The recording sheet 33 on which the unfixed toner image T is fixed includes the rotating member 62 and the endless belt. While being nipped and conveyed by the nip part 63 formed between the rotating member 62 and the endless belt 61, heat is taken away and cooled.

  As a result, the temperature of the rotating member 62 and the endless belt 61 gradually increases due to heat conduction from the plurality of recording sheets 33 when the plurality of recording sheets 33 pass continuously. At this time, since the endless belt 61 is in contact with the high thermal conductivity fixed sliding member 64, heat is efficiently transferred to the material 68 through the pressure contact member 75 of the high thermal conductive fixed sliding member 64. Is done.

  The heat transferred to the material 68 of the high thermal conductivity fixed sliding member 64 is efficiently radiated through the two heat pipes 69 and 70. The heat transmitted to the two heat pipes 69 and 70 is dissipated by the air blown by the wind fans 73 and 74 from the heat radiation fins 71 and 72 provided on the protrusions 69a and 70a.

  Therefore, the heat quantity of the recording paper 33 taken away by the endless belt 61 is efficiently radiated by the two heat pipes 69 and 70 through the material 68 of the high thermal conductive fixed sliding member 64, and the recording paper 33 Can be effectively cooled.

  Further, since the endless belt 61 is made of a thin material, heat is not stored, and the heat transmitted to the endless belt 61 is immediately transmitted to the material 68 of the high thermal conductivity fixed sliding member 64, and the endless belt 61 61 is always in a cooled state, and the recording paper 33 can be efficiently cooled.

  Further, since the endless belt 61 is in pressure contact with the rotating member 62, the conduction heat from the rotating member 62 is transmitted to the material 68 of the high heat conductive fixed sliding member 64 via the endless belt 61 and rotated. The member 62 can also be efficiently cooled.

  In addition, the nip width between the endless belt 61 and the rotating member 62 can be widened, and from this point, high cooling efficiency can be obtained as compared with an apparatus in which rolls are pressed against each other.

  Furthermore, since the endless belt 61 does not need to be rotationally driven, it is possible to prevent the belt from being displaced with a simple configuration.

  As described above, in the sheet cooling and conveying apparatus according to the above-described embodiment, it is possible to efficiently discharge the heat of the sheet after fixing and cool the apparatus with a simple configuration without causing the apparatus to be complicated or the apparatus to be enlarged. And can be transported.

EXAMPLES Examples of the present invention are shown below, but the present invention is not limited to these examples.

  The endless belt 61 was a nickel electroformed belt having an inner diameter of 30 mm, a thickness of 50 μm, and a length of 330 mm as a base material, and PFA was coated to a thickness of 30 μm on the outer peripheral surface to form a release layer. The inner peripheral surface of the endless belt 61 is coated with a clay 300 cs amino-modified silicone oil as a lubricant.

  The high heat conductive fixed sliding member 64 is made of aluminum, and two heat pipes 69 and 70 are joined therein. The heat pipes 69 and 70 were made of copper having grooves inside and containing wigs 69a. The high heat conductive fixed sliding member 64 is provided with a belt guide 74 made of resin so that the endless belt 61 rotates smoothly.

  The ends of the high heat conductive fixed sliding member 64 are as shown in FIG. 3, and cooling air is supplied to the heat radiating fins 71, 72 provided on the heat pipes 69, 70 using the cooling fans 73, 74. Cool by flowing. At this time, the air flow direction of the cooling fans 73 and 74 was parallel to the heat radiation fins 71 and 72.

  The rotating member 62 covers a sponge-like elastic layer 66 obtained by foaming silicon on a metal core 65 made of stainless steel with a high heat conductive member 67 made of stainless steel manufactured in a thin film shape having a thickness of 30 μm, and is further formed thereon. A cylindrical roller having an outer diameter of 26 mm and a length of 360 mm formed by covering a PFA tube (not shown) having a thickness of 30 μm.

  The pressure of the sliding member 64 was adjusted so that the nip width formed by the rotating member 62 and the high thermal conductive fixed sliding member 64 was 15 mm.

  Further, a driving force from a motor (not shown) was transmitted to the rotating member 62, and the rotating member 62 and the endless belt 61 were rotated at a speed of 104 mm / sec.

Using the sheet cooling / conveying device 60 of the above embodiment, the surface temperature of the toner after fixing the sample on which the unfixed toner image T is formed on the single-side coated paper 33 having a basis weight of 127 g / m ² is passed through the conveying nip 63. When measured before and after passing, there was a 9 ° C. cooling effect by passing through the sheet cooling and conveying device 60. The same experiment with the same configuration as in the above embodiment was performed by continuously passing 10,000 sheets. However, the endless belt 61 was not broken, wrinkled, or the fixed image did not occur.

  As described above, according to the first embodiment, the high thermal conductivity fixed sliding member 64 is pressed against the rotating member 62 having the elastic layer 66 via the endless belt 61 that is not stretched. As a result, the nip width can be widened, so that the cooling efficiency can be increased, and the apparatus can be simplified because there is no need for belt walk control or the like. Further, since the image surface is in contact with the rotating member 62 made of the elastic layer 66, it is possible to prevent image distortion.

Embodiment 2
FIG. 4 shows a second embodiment of the present invention. The same parts as those of the first embodiment are denoted by the same reference numerals, and in this embodiment, the endless belt and the rotating member are separated. The arrangement is different from that of the first embodiment.

  That is, in the sheet cooling and conveying apparatus 60 according to the second embodiment, as shown in FIG. 4, the endless belt 61 is disposed at the upper part and the rotating member 62 is disposed at the lower part.

  Since other configurations and operations are the same as those of the first embodiment, description thereof is omitted.

1 is a block diagram showing a sheet cooling and conveying apparatus according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing a color electrophotographic copying machine to which the sheet cooling and conveying apparatus according to Embodiment 1 of the present invention is applied. FIG. 3 is a block diagram showing the sheet cooling and conveying apparatus according to Embodiment 1 of the present invention. 4 is a block diagram showing a sheet cooling and conveying apparatus according to Embodiment 2 of the present invention.

Explanation of symbols

  60: Sheet cooling / conveying device, 61: Endless belt, 62: Rotating member, 64: High heat conductive fixed sliding member.

Claims (7)

An endless belt, a rotating member disposed to face the endless belt, and a position facing the rotating member in the endless belt, and by pressing the endless belt against the rotating member, the endless belt and the rotating member A highly-slidable fixed sliding member that forms a nip portion for cooling at the pressure contact portion of
A sheet cooling and conveying apparatus, wherein the sheet is conveyed so that a fixed image surface of the sheet is in contact with either the rotating body or the endless belt. In the sheet cooling and conveying apparatus according to claim 1,
The sheet cooling and conveying apparatus, wherein the endless belt is made of a metal material. In the sheet cooling and conveying apparatus according to claim 1,
A sheet cooling / conveying device configured to apply a lubricant to an inner peripheral surface of the endless belt. In the sheet cooling and conveying apparatus according to claim 1,
The sheet cooling and conveying device, wherein the rotating member is formed by coating a high thermal conductive layer on an outer peripheral surface of an elastic layer coated on a surface of a metal core member. In the sheet cooling and conveying apparatus according to claim 1,
The sheet cooling / conveying device, wherein the rotating member is formed by coating a highly releasable layer on an outer peripheral surface of an elastic layer coated on a surface of a cored bar member. In the sheet cooling and conveying apparatus according to claim 1,
The fixed sliding member is provided with a cooling means at an end portion in the axial direction thereof. 7. An image forming apparatus, wherein the sheet cooling and conveying apparatus according to claim 1 is disposed downstream of the fixing unit in the sheet conveying direction.

Images