JP2015106019A - Conveyance device, cooling device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveyance device capable of improving the conveyability of a belt conveying a member to be conveyed and an image forming apparatus.SOLUTION: A recording paper 5 is cooled by a heat sink 74 arranged on the inner peripheral side of a first conveyance belt 73, while the recording paper 5 after fixation processing is performed is conveyed by the first conveyance belt 73 and a second conveyance belt 75 in a state of being held between the first conveyance belt 73 and the second conveyance belt 75. First and second driving rolls 731 and 751 driving the first and second conveyance belts 73 and 75 are provided in a discharge part for the recording paper 5 located on the downstream side of the heat sink 74 in a blet moving direction. The second driving roll 751 includes an elastic body layer 751b as a surface layer and the first and second conveyance belts 73 and 74 are arranged in a press-contact state, so that the elastic body layer 751b of the second driving roll 751 is elastically deformed. Thus, the conveyability of the first and second conveyance belts 73 and 75 is improved.

Description

  The present invention relates to a conveyance device, a cooling device, and an image forming apparatus.

  As a technique related to the transport apparatus, the technique disclosed in Patent Document 1 has already been proposed. Patent Document 1 drives a first belt that circulates in contact with a cooling body on an inner peripheral side, and also brings a second belt that conveys a recording material with the first belt to the first belt. Are configured to circulate.

JP-A-5-27603

  Incidentally, the problem to be solved by the present invention is to improve the transportability of a belt that transports a member to be transported.

  Another object of the present invention is to provide a transport device, a cooling device, and an image forming apparatus that can be reduced in size by reducing the number of parts that circulate and move the belt.

The invention described in claim 1 includes an endless first belt that circulates and moves,
An endless second belt that is disposed on the outer peripheral side of the first belt, circulates and moves with the conveyed member sandwiched between the first belt, and conveys the conveyed member;
A contact member disposed on the inner peripheral side of the first belt and in contact with the transported member transported by the second belt via the first belt;
The elastic member layer provided on one side is disposed so as to be elastically deformed to the discharge portion of the transported member located on the downstream side of the contact member in the belt moving direction, and the first and second members First and second driving rotating bodies that respectively drive the belt;
It is the conveyance apparatus characterized by including.

  According to a second aspect of the present invention, in the transport device according to the first aspect, the first and second driving rotating bodies are arranged in a state in which an inter-axis distance is fixed. is there.

  The invention described in claim 3 is the conveying apparatus according to claim 1 or 2, wherein the elastic body layer is provided on a second driving rotating body that drives the second belt. is there.

  According to a fourth aspect of the present invention, the driving means for rotationally driving the second driving rotating body includes torque limiting means for limiting the driving torque of the second driving rotating body, and the second belt. 4. The transport device according to claim 3, wherein a moving speed of the first belt is set to be equal to or higher than a moving speed of the first belt. 5.

  The invention described in claim 5 includes a first unit to which the first belt is attached and a second unit to which the second belt is attached, and the first unit is connected to the second unit. The conveying device according to any one of claims 1 to 4, wherein the conveying device is configured to be movable in a direction of contacting or separating.

  According to a sixth aspect of the present invention, the contact member comprises a cooling member that cools the transported member via the first belt, and cooling as the transport device according to any one of the first to fifth aspects. Device.

The invention described in claim 7 is an image forming unit that forms an image on a recording medium;
Fixing means for fixing by heating a recording medium on which an image is formed by the image forming unit;
The image forming apparatus including the cooling device according to claim 6, wherein the recording medium on which the image is fixed by the fixing unit is cooled as the transported member.

  According to the first aspect of the present invention, it is possible to improve the transportability of the belt as compared with the case where the first belt is driven and the second belt is driven.

  According to the second aspect of the present invention, the first and second driving rotating bodies can be reliably connected to the first and second driving rotating bodies as compared with the case where the inter-axis distance of the first and second driving rotating bodies can be changed. A driving force can be transmitted.

  According to the third aspect of the present invention, it is possible to suppress fluctuations in the rotational speed of the first driving rotating body as compared with the case where the elastic body layer is provided on the first driving rotating body.

  According to the fourth aspect of the present invention, even when the elastic layer of the second driving rotating body is worn, it is possible to suppress the occurrence of speed fluctuation in the rotation of the second driving rotating body. .

  According to the fifth aspect of the present invention, it is possible to cope with the conveyance abnormality of the conveyed member that occurs between the first and second belts.

  According to the invention described in claim 6, it is possible to reduce the size of the cooling device for cooling the member to be transported.

  According to the invention described in claim 7, it is possible to reduce the size of the image forming apparatus as compared with the case where the cooling apparatus described in claim 6 is not provided.

1 is a configuration diagram showing an outline of an image forming apparatus to which a conveying device according to Embodiment 1 of the present invention is applied. 2 is a configuration diagram illustrating an image forming unit of the image forming apparatus. FIG. It is a block diagram which shows the cooling device as a conveying apparatus which concerns on Embodiment 1 of this invention. It is a schematic block diagram which shows the drive system of the cooling device as a conveying apparatus which concerns on Embodiment 1 of this invention. It is a schematic perspective view which shows the contacting / separating mechanism of the cooling device as a conveying apparatus which concerns on Embodiment 1 of this invention. It is a schematic perspective view which shows the contacting / separating mechanism of the cooling device as a conveying apparatus which concerns on Embodiment 1 of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, modes for carrying out the present invention (simply referred to as “embodiments”) will be described with reference to the accompanying drawings.

  1 and 2 show an image forming apparatus to which the conveying apparatus according to the first embodiment is applied. FIG. 1 shows an outline of the entire image forming apparatus, and FIG. 2 shows an enlarged main part (image forming apparatus, etc.) in the image forming apparatus.

<Overall Configuration of Image Forming Apparatus>
The image forming apparatus 1 according to the first embodiment is configured as a color printer, for example. The image forming apparatus 1 holds a plurality of image forming apparatuses 10 that form toner images developed with toner constituting the developer 4 and the toner images formed by the respective image forming apparatuses 10 and finally An intermediate transfer device 20 that transports the recording sheet 5 as an example of a transported member (recording medium) to a secondary transfer position for secondary transfer, and a required recording sheet 5 to be supplied to the secondary transfer position of the intermediate transfer device 20 A sheet feeding device 50 that accommodates and conveys the toner, and a fixing device 40 that fixes the toner image on the recording paper 5 secondarily transferred by the intermediate transfer device 20.

  The image forming apparatus 1 includes a first housing 1a and a second housing 1b, and the first and second housings 1a and 1b are formed of a support structure member, an exterior cover, and the like. In addition, a two-dot chain line in the figure indicates a main conveyance path through which the recording paper 5 is conveyed inside the first and second casings 1a and 1b.

  The image forming apparatus 10 exclusively forms four color toner images of yellow (Y), magenta (M), cyan (C), and black (K) and two types of toner images of special colors S1 and S2. It is composed of six image forming apparatuses 10Y, 10M, 10C, 10K, 10S1, and 10S2. The six image forming devices 10 (S1, S2, Y, M, C, and K) are arranged in a line in the internal space of the first housing 1a. As the developer 4 (S1, S2) of the special color (S1, S2), for example, those composed of color materials that are difficult or impossible to express with the above four colors are used. Is a toner of a color other than the above four colors, a toner having the same color as that of the above four color toners and having a different saturation, a transparent toner for improving gloss, a foaming toner for Braille, a fluorescent color toner, and the like. In addition, the image forming apparatuses 10 (S1, S2, Y, M, C, and K) have substantially the same configuration as described below except that the types of developers to be handled are different.

  Each image forming apparatus 10 (S1, S2, Y, M, C, and K) includes a photosensitive drum 11 as an example of a rotating image carrier, as shown in FIG. 1 and FIG. The following devices are mainly arranged around the photosensitive drum 11. The main devices are a charging device 12 that charges a peripheral surface (image holding surface) on the photosensitive drum 11 on which an image can be formed to a required potential, and image information (on the charged peripheral surface of the photosensitive drum 11). The exposure device 13 as an electrostatic latent image forming unit that irradiates the light LB based on the signal) to form an electrostatic latent image (for each color) having a potential difference, and the corresponding electrostatic latent image (S1, S1). A developing device 14 (S1, S2, Y, M, C, K) as developing means for developing a toner image by developing with the toner of the developer 4 (S2, Y, M, C, K) and each toner image thereof A primary transfer device 15 that transfers the toner to the intermediate transfer device 20, a drum cleaning device 16 that removes and removes adhering matter such as toner remaining on the image holding surface of the photoconductor drum 11 after the primary transfer, and a photoconductor A static eliminator 17 or the like that neutralizes the image holding surface after cleaning the drum 11. .

  The photosensitive drum 11 is formed by forming an image holding surface having a photoconductive layer (photosensitive layer) made of a photosensitive material on the peripheral surface of a cylindrical or columnar base material to be grounded. The photosensitive drum 11 is supported so as to rotate in a direction indicated by an arrow A when power is transmitted from a rotation driving device (not shown).

  The charging device 12 is configured by a non-contact type charging device such as a corona discharger that is disposed without being in contact with the photosensitive drum 11.

  The exposure device 13 irradiates light (solid line with arrows) LB configured according to image information input to the image forming device 1 onto the peripheral surface of the charged photosensitive drum 11 to statically. It forms an electrostatic latent image. When the latent image is formed, image information (signal) input to the image forming apparatus 1 by any means is transmitted to the exposure apparatus 13.

  As shown in FIG. 2, each of the developing devices 14 (S1, S2, Y, M, C, and K) includes a developer in a housing 140 in which an opening and a storage chamber for the developer 4 are formed. 4, a developing roll 141 that conveys the developer 4 to a developing area facing the photosensitive drum 11, a stirring conveyance member such as a screw auger (not shown) that conveys the developer 4 while passing the developing roll 141 while stirring, and a developing roll A layer thickness regulating member (not shown) that regulates the amount (layer thickness) of the developer held at 141 is arranged. A developing voltage is supplied to the developing device 14 from a power supply device (not shown) between the developing roll 141 and the photosensitive drum 11. Further, the developing roller 141 and the agitating / conveying member (not shown) are rotated in a required direction by receiving power from a rotation driving device (not shown). Further, as the four color developers 4 (Y, M, C, K) and the two special color developers 4 (S1, S2), a two-component developer containing a non-magnetic toner and a magnetic carrier is used. Is done. In FIG. 1, reference numeral 142 denotes a toner cartridge that contains a developer containing at least the corresponding color toner to be supplied to the developing device 14 (S1, S2, Y, M, C, K).

  The primary transfer device 15 is in contact with the peripheral surface of the photosensitive drum 11 at the primary transfer position T1 via the intermediate transfer belt 21 and rotates, and a contact type transfer device including a primary transfer roll to which a primary transfer voltage is supplied. It is. As the primary transfer voltage, a DC voltage having a polarity opposite to the charging polarity of the toner is supplied from a power supply device (not shown).

  As shown in FIG. 2, the drum cleaning device 16 is disposed inside a container-shaped main body (not shown), removes adhered matters such as residual toner, and cleans the toner, and the toner removed by the cleaning plate 161. It is configured by a delivery member such as a screw auger (not shown) that conveys the adhering matter to collect it and send it to a collection system (not shown). As the cleaning plate 161, a plate-like member (for example, a blade) made of a material such as rubber is used.

  As shown in FIG. 1, the intermediate transfer device 20 is disposed so as to exist at a position below each image forming device 10 (S1, S2, Y, M, C, K). The intermediate transfer device 20 includes an intermediate transfer belt 21 that circulates in a direction indicated by an arrow B while passing through a primary transfer position between the photosensitive drum 11 and the primary transfer device 15 (primary transfer roll), and an intermediate transfer belt. A plurality of belt support rolls 22 to 28 that hold the belt 21 in a desired state from the inner surface and support the belt 21 in a freely circulating manner, and an outer peripheral surface (image holding surface) side of the intermediate transfer belt 21 supported by the belt support roll 26 And a secondary transfer device 30 that secondary-transfers the toner image on the intermediate transfer belt 21 to the recording paper 5 and remains on the outer peripheral surface of the intermediate transfer belt 21 after passing through the secondary transfer device 30. The belt cleaning device 29 mainly removes the adhering matter such as toner and paper dust and cleans it.

  As the intermediate transfer belt 21, for example, an endless belt made of a material in which a resistance adjusting agent such as carbon black is dispersed in a synthetic resin such as polyimide resin or polyamide resin is used. The belt support roll 22 is configured as a drive roll, the belt support rolls 23, 25, 27, and 28 are configured as driven rolls that hold the travel position of the intermediate transfer belt 21, and the belt support roll 24 is configured as a tension applying roll. The belt support roll 26 is configured as a secondary transfer backup roll.

  As shown in FIG. 1, the secondary transfer device 30 rotates at a secondary transfer position T <b> 2 that is an outer peripheral surface portion of the intermediate transfer belt 21 supported by the belt support roll 26 in the intermediate transfer device 20. Consists of roles. Further, a DC voltage having a polarity opposite or the same as the charging polarity of the toner is supplied as a secondary transfer voltage to the secondary transfer roll 30 or the support roll 26 of the intermediate transfer device 20.

  In this embodiment, the image forming device 10 (S1, S2, Y, M, C, K), the intermediate transfer device 20, and the secondary transfer device 30 constitute an image forming unit.

  A fixing device 40 as an example of a fixing unit is disposed inside a casing 41 and is rotated by a driving roll 42 in a direction indicated by an arrow, and an inner surface as an example of a heating unit so that the surface temperature is maintained at a predetermined temperature. A fixing belt 45 heated by the heating roll 43 and the external heating roll 44, and a pressure roll 46 that rotates in contact with the fixing belt 45 wound around the driving roll 42 at a required pressure are arranged. It is a thing. In the fixing device 40, a contact portion where the fixing belt 45 and the pressure roll 46 come into contact becomes a fixing processing portion that performs a required fixing process (heating and pressing).

  The paper feeding device 50 is disposed so as to exist at a position below the intermediate transfer device 20 and the secondary transfer device 30. The paper feeding device 50 includes a plurality (or a single) of paper storage bodies 51 and 51 for storing recording paper 5 of a desired size and type, and the recording paper 5 from the paper storage body 51 one by one. It is mainly comprised by the sending-out apparatus 52 to send out. The paper container 51 is attached, for example, so that it can be pulled out to the front side (side surface on which the user faces during operation) of the first housing 1a.

  Between the paper feeding device 50 and the secondary transfer device 30, a plurality of paper conveyance roll pairs 53 and 54 for conveying the recording paper 5 delivered from the paper feeding device 50 to the secondary transfer position T2 and a conveyance guide material (not shown). Are provided. A pair of paper transporting rolls 54 disposed at a position immediately before the secondary transfer position T2 in the paper feed transporting path 56 is configured as a roll (registration roll) that adjusts the transporting timing of the recording paper 5, for example. At a middle position of the paper feed transport path 56, a paper feed transport path 57 that receives and transports the recording paper 5 supplied from a large-capacity paper feed device (not shown) disposed adjacent to the first housing 1a. Are joined. Further, since the recording paper 5 after the secondary transfer fed from the secondary transfer roll 30 is conveyed to the fixing device 40 between the secondary transfer device 30 and the fixing device 40, in the illustrated example, a quadruple belt configuration is used. The sheet transport devices 58a to 58d such as are provided inside the second housing 1b.

  On the downstream side of the fixing device 40, a cooling device 70 is disposed as an example of a conveying device that cools the recording paper 5 on which the toner image is fixed by the fixing device 40 via a paper conveying device 59 such as a belt shape. . Further, on the downstream side of the cooling device 70, the recording paper 5 is conveyed while being sandwiched by a plurality of rolls, belts, and the like, thereby correcting the curving of the recording paper 5, and the recording paper 5 A detection device 90 is sequentially provided for detecting a toner density defect, an image defect, an image position defect, and the like of the toner image fixed on the toner image. The detection device 90 irradiates light onto the recording paper 5 from the light source, and reads reflected light reflected upward by the recording paper 5 with an image reading element such as a CCD image sensor, thereby causing toner density defects, image defects, and image positions. Detect defects and the like.

  Furthermore, in a portion near the paper discharge port formed in the second housing 1b, the paper discharge section 60 in which the recording paper 5 after passing through the detection device 90 is disposed outside the second housing 1b. A paper discharge path 62 having a paper discharge roll pair 61 for discharging the paper is provided. Below the pair of paper discharge rolls 61, a reverse path 63 is disposed that reverses and conveys the recording paper 5 when forming images on both sides of the recording paper 5. The reversing path 63 temporarily accommodates the double-sided conveyance path 64 that switches the conveyance direction of the recording sheet 5 downward, and the recording sheet 5 that is conveyed along the double-sided conveyance path 64, and changes the conveyance direction of the recording sheet 5. A reverse feed path 65 that reverses and feeds paper to the paper feed conveyance path 53 is provided.

  In FIG. 1, reference numeral 101 denotes an image processing unit that performs image processing on image data sent from an external device such as a computer provided in the upper part of the second housing 1 b, and 102 denotes an operation of the image forming apparatus 1. A control unit 103 performs overall control, and a user interface unit 103 allows a user to operate the image forming apparatus 1.

<Basic operation of image forming apparatus>
Hereinafter, a basic image forming operation by the image forming apparatus 1 will be described.

  Here, first, a full-color image constituted by combining toner images of four colors (Y, M, C, K) using the four image forming devices 10 (Y, M, C, K). The image forming operation at the time of forming will be described as a representative.

  When the image forming apparatus 1 receives command information for requesting an image forming operation (printing), the four image forming apparatuses 10 (Y, M, C, K), the intermediate transfer apparatus 20, the secondary transfer apparatus 30, and the fixing apparatus. 40 etc. starts.

  In each image forming device 10 (Y, M, C, K), each photoconductor drum 11 is first rotated in the direction indicated by an arrow A, and each charging device 12 makes a required surface of each photoconductor drum 11 on the surface. Each is charged to a polarity (negative polarity in the first embodiment) and a potential. Subsequently, the exposure apparatus 13 converts the image information input to the image forming apparatus 1 into each color component (Y, M, C, K) with respect to the surface of the photosensitive drum 11 after charging. The light LB emitted based on this signal is irradiated, and an electrostatic latent image of each color component composed of a required potential difference is formed on the surface thereof.

  Subsequently, each developing device 14 (Y, M, C, K) has a corresponding color charged with a required polarity (minus polarity) with respect to the electrostatic latent image of each color component formed on the photosensitive drum 11. (Y, M, C, K) toners are respectively supplied and electrostatically adhered to perform development. By this development, the electrostatic latent images of the respective color components formed on the respective photosensitive drums 11 are visualized as toner images of four colors (Y, M, C, K) respectively developed with the corresponding color toners. It becomes.

  Subsequently, when the toner images of the respective colors formed on the photosensitive drums 11 of the respective image forming devices 10 (Y, M, C, K) are conveyed to the primary transfer position T1, the primary transfer device 15 causes the respective colors. Are transferred to the intermediate transfer belt 21 rotating in the direction indicated by the arrow B of the intermediate transfer device 20 in such a manner that the toner images are sequentially superimposed.

  Further, in each image forming device 10 for which the primary transfer has been completed, the drum cleaning device 16 removes the adhering material so as to scrape off and cleans the surface of the photosensitive drum 11. Finally, the static eliminator 17 performs the photosensitive operation after the cleaning. The surface of the body drum 11 is neutralized. Thereby, each image forming apparatus 10 is brought into a state in which the next image forming operation can be performed.

  Subsequently, in the intermediate transfer device 20, the toner image primarily transferred by the rotation of the intermediate transfer belt 21 is held and conveyed to the secondary transfer position T2. On the other hand, the paper feeding device 50 sends out the required recording paper 5 to the paper feeding conveyance paths 55 and 56 in accordance with the image forming operation. In the paper feeding / conveying path 56, a pair of paper conveying rolls 54 as resist rolls feeds the recording paper 5 to the secondary transfer position T2 in accordance with the transfer timing.

  At the secondary transfer position T <b> 2, the secondary transfer roll 30 performs secondary transfer of the toner image on the intermediate transfer belt 21 onto the recording paper 5 at once. Further, in the intermediate transfer device 20 that has finished the secondary transfer, the belt cleaning device 29 removes the adhering matter such as toner remaining on the surface of the intermediate transfer belt 21 after the secondary transfer, and cleans it.

  Subsequently, the recording sheet 5 on which the toner image is secondarily transferred is peeled off from the intermediate transfer belt 21 and the secondary transfer roll 30 and then conveyed to the fixing device 40 by the conveying devices 58a to 58d. In the fixing device 40, necessary recording processing (heating and pressing) is performed by introducing and passing the recording paper 5 after the secondary transfer through a contact portion between the rotating fixing belt 45 and the pressure roll 46. Then, the unfixed toner image is fixed on the paper 5. The recording paper 5 after the fixing is finished is cooled by the cooling device 70, and the curvature (curl) is corrected and made flat by the correction device 80, and then an image defect or the like is detected by the detection device 90. When the image forming operation is performed only to form an image on the sheet, the sheet is discharged to the discharge container 60 disposed outside the second casing 1b by the sheet discharge roll pair 61 via the sheet discharge path 62, for example. The

  When forming images on both sides of the recording sheet 5, the recording sheet 5 is introduced into the reversing path 63 via the duplex conveying path 64, and the reversing paper feeding path 65 provided in the middle of the reversing path 63. Thus, the recording paper 5 passes through the paper feed conveyance path 56 and is conveyed again to the secondary transfer position T2 in a state where the traveling direction of the recording paper 5 is reversed (the front and back are reversed). Then, as described above, after the toner image is fixed by the fixing device 40, the recording paper 5 on which the image is transferred to the back surface at the secondary transfer position T2 is cooled by the cooling device 70, and the correction device 80 and the detection device are detected. The paper is discharged to the discharge container 60 by the paper discharge roll pair 61 through the device 90.

  Through the above operation, the recording paper 5 on which a full color image formed by combining four color toner images is output.

  Next, the operation when the image forming apparatus 1 forms a special color toner image composed of the developer of the special colors S1 and S2 when performing the normal image formation described above, for example, will be described.

  In this case, first, in the image forming apparatuses 10S1 and 10S2, the same image forming operation as that of the image forming apparatus 10 (Y, M, C, K) described above is performed. Special color toner images (S1, S2) are formed on the photosensitive drum 11, respectively. Subsequently, the special color toner images formed by the image forming devices 10S1 and 10S2 are primarily transferred to the intermediate transfer belt 21 of the intermediate transfer device 20 in the same manner as the image forming operation related to the four color toner images described above. After that, the secondary transfer device 30 performs secondary transfer from the intermediate transfer belt 21 to the recording paper 5 (along with toner images of other colors). Finally, the recording paper 5 on which the special color toner image and the toner image of the other color are secondarily transferred is subjected to the fixing process in the fixing device 40, and then passes through the required devices 70, 80, 90 to the second casing. It is discharged outside the body 1b.

  Through the above operation, the recording paper 5 formed so that the two special color toner images are overlapped on the entire surface or a part of the full color image formed by combining the above-described four color toner images is output. The

  The image forming apparatus 1 directly records toner images formed by the image forming apparatuses 10 (S1, S2, Y, M, C, and K) without using the intermediate transfer belt 21 of the intermediate transfer apparatus 20. It may be configured to transfer onto the paper 5.

<Configuration of cooling device>
FIG. 3 is a block diagram showing a cooling device of the image forming apparatus according to the first embodiment.

  As shown in FIG. 3, the cooling device 70 is roughly divided into an upper unit 71 as an example of a first unit disposed above and a lower unit 72 as an example of a second unit disposed below. Prepare. The upper unit 71 includes a first conveyor belt 73 as an example of a first belt that circulates and a heat sink (cooling member) 74 as an example of a contact member disposed on the inner peripheral side of the first conveyor belt 73. have. The lower unit 72 is disposed on the inner side of the second conveyor belt 75 as an example of the second belt that circulates and moves on the inner periphery side of the second conveyor belt 75. A pressing roll 76 as an example of a pressing member that presses against the heat sink 74 with a belt 73 interposed therebetween is provided.

  As the first conveying belt 73, for example, an endless belt made of a synthetic resin material such as polyimide is used. The first conveyor belt 73 is supported so as to circulate and move by a plurality of belt support rolls 731 to 735 in a state where a required tension is applied.

  In this embodiment, the first and second transport belts 73 and 75 are respectively driven to the discharge portion 76 of the recording paper 5 located close to the downstream side of the heat sink 74 along the belt moving direction. As an example of the second driving rotating body, first and second driving rolls 731 and 751 are arranged in pressure contact with each other via the first and second conveying belts 73 and 75. The first and second drive rolls 731 and 751 also serve as discharge rolls that discharge the recording paper 5 cooled by the heat sink 74.

  The first driving roll 731 has a frictional force between the circumferential surface of a cylindrical or columnar base material 731a made of a material having rigidity such as a synthetic resin or metal and the inner circumferential surface of the first conveying belt 73. The coating layer (surface layer) 731b made of a urethane resin or the like for increasing the thickness is coated to a thickness of about 75 μm, for example. The first drive roll 731 is attached to the frame 711 of the upper unit 71 with the position of the rotation shaft fixed. The first drive roll 731 is wound over a winding angle of about 90 degrees or more in order to effectively transmit the driving force to the first transport belt 73. As shown in FIG. 4, the first drive roll 731 has a required rotational speed via a plurality of drive gears 772 and 773 as drive force transmission means by a first drive motor 771 as a first drive source. The driving force is transmitted so as to be rotatable. In addition, coupling members 774a and 774b that can be brought into contact with and separated from the driving source side are arranged at the end of the first driving roll 731 on the driving force transmission side.

  The second drive roll 751 is provided with an elastic layer 751b made of urethane foam (urethane sponge) or the like on the peripheral surface of a cylindrical or columnar base material 751a made of a material having rigidity such as metal. It is configured to cover a thickness (for example, about 6 mm). In addition, for example, the outer diameter of the second drive roll 751 is set to the same value (same diameter) as that of the first drive roll 731. The second drive roll 751 is attached to the frame 721 of the lower unit 72 in a state where the position of the rotation shaft is fixed. Therefore, in a state where the upper unit 71 and the lower unit 72 are positioned at required positions, the distance between the axes of the first drive roll 731 and the second drive roll 751 is fixed to a predetermined value. In this state, the elastic body layer 751b of the second drive roll 751 is elastically deformed, and is pressed against the first drive roll 731 with the elastic restoring force of the elastic body layer 751b. The second driving roll 751 is wound around a winding angle of about 90 degrees or more in order to effectively transmit the driving force to the second conveying belt 75. As shown in FIG. 4, the second drive roll 751 is rotated by a drive motor 781 as a drive source via a plurality of drive gears 782 and 783 as drive force transmission means. The driving force is transmitted so as to be rotationally driven at a speed equal to or higher than the (circumferential speed). In addition, coupling members 784a and 784b that can be brought into contact with and separated from the drive source side are disposed at the end of the second drive roll 751 on the drive force transmission side.

  Further, the second driving roll 751 is provided with a torque limiter 785 as an example of a torque limiting means at an intermediate position of the driving force transmitting means. The torque limiter 785 interrupts transmission of the rotational driving force when the driving torque of the second driving roll 751 exceeds a required value.

  Of the plurality of belt support rolls that support the first transport belt 73, the belt support rolls 732, 734, and 735 are configured as driven rolls that hold the travel position of the first transport belt 73, and the belt support rolls. Reference numeral 733 denotes a tension applying roll that applies a required tension to the first conveying belt 73. The belt support rolls 731 to 735 have a length approximately the same as the width of the first transport belt 73 along a direction (axial direction) intersecting the moving direction of the first transport belt 73.

  The belt support rolls 731 to 735 are arranged so as to surround the heat sink 74, and the size of the upper unit 71 constituting the cooling device 70 is reduced. The first to third driven rolls 732, 744, and 735 are rotatably supported by the frame 711 of the upper unit 71.

  As shown in FIG. 3, the heat sink 74 as an example of a contact member disposed on the inner peripheral side of the first transport belt 73 so as to contact a part of the inner peripheral surface of the first transport belt 73. Is provided. The heat sink 74 is in contact with the inner peripheral surface of the first conveyor belt 73 in the stretched region between the drive roll 731 and the third driven roll 735. The drive roll 731 and the third driven roll 735 are disposed above the lower end surface of the heat sink 74, and the first transport belt 73 is disposed so as to contact the lower end surface of the heat sink 74 by its tension. The heat sink 74 is made of a material having a higher thermal conductivity than that of the first transport belt 73, and is made of, for example, a metal material such as aluminum. Of course, the heat sink 74 may be made of other materials. The heat sink 74 includes a substrate 741 in contact with the first transport belt 73 at the lower end thereof. The lower end surface 741a of the substrate 741 that is in contact with the first conveying belt 73 is formed in a curved shape so as to be convex downward. Further, the upstream and downstream ends of the substrate 741 along the belt moving direction have a curved shape with a small radius of curvature.

  The substrate 741 has a width equal to or greater than that of the first conveyor belt 71 along a direction intersecting with the moving direction of the first conveyor belt 73 (hereinafter referred to as “belt width direction”). doing. Further, the length of the substrate 741 along the moving direction of the first conveying belt 71 is set in consideration of the cooling efficiency of the recording paper 5. In this embodiment, the cooling device 70 is significantly reduced in size as compared with the conventional device, and the length of the substrate 741 along the belt moving direction is set to about 75 mm, for example.

  A thin heat sink 742 formed in a thin flat plate shape is disposed on the upper end surface of the substrate 741 along the width direction of the belt and is spaced apart from the substrate 741 along the belt movement direction. A plurality are arranged so as to come into contact with each other. In addition, side plates 743 and 744 that partition a space in which the plurality of heat dissipation plates 742 are disposed are provided at upstream and downstream ends of the heat dissipation plates 742 in the belt moving direction. Further, a ceiling plate 745 is disposed at the upper end of the plurality of heat radiating plates 742 from the upstream side plate 743 to the downstream side plate 744. The heat sink 74 forms a closed space in which the bottom surface and the top surface of the plurality of heat radiating plates 742 and the upstream and downstream side surfaces are surrounded by the substrate 741, both side plates 743, 744 and the ceiling plate 745. Further, both side surfaces (the front side and the back side in the direction perpendicular to the drawing) of the heat sink 74 along the belt width direction are opened all over.

  The heat sink 74 includes a cooling fan 746 as a cooling means on the back side (the back side in the direction perpendicular to the drawing). The cooling fan 746 is rotationally driven when the cooling device 70 is operated, and discharges air sucked from the front side (the front side in the direction perpendicular to the drawing) of the image forming apparatus 1 to the back side (the back side in the direction perpendicular to the drawing). As a result, the air flow is brought into contact with each heat radiating plate 742 to dissipate heat from each heat radiating plate 742. In this embodiment, the heat sink 74 is greatly reduced in size, and the cross-sectional shape of the heat sink 74 is set smaller than the outer diameter of the cooling fan 746.

  As the second conveyor belt 75, an endless belt made of a synthetic resin material such as polyimide is used, for example, as with the first conveyor belt 73. The second conveyor belt 75 is supported so as to circulate and move by a plurality of belt support rolls 751 to 754 while being stretched with a required tension. Among the plurality of belt support rolls, the belt support rolls 752 and 754 are configured as driven rolls that hold the travel position of the second transport belt 75, and the belt support roll 753 applies a required tension to the second transport belt 75. It is comprised as a tension | tensile_strength provision roll to provide. The lengths of the belt support rolls 751 to 754 along the direction (axial direction) intersecting the moving direction of the second transport belt 75 are set to be approximately the same as the width of the second transport belt 75. The first and second driven rolls are rotatably supported by the frame 721 of the lower unit 72.

  The second conveying belt 75 has a larger width than the recording paper 5 of the maximum size along the width direction of the recording paper 5 on which an image is formed by the image forming apparatus 1.

  On the inner peripheral side of the second conveyor belt 73, the second conveyor belt 75 is connected to the end of the heat sink 74 where the first conveyor belt 73 starts to contact the heat sink 74. A pressing roll 76 as an example of a pressing member that presses against the heat sink 74 is disposed. In this embodiment, a pressing roll 76 is disposed at the upstream end of the heat sink 74 along the moving direction of the first conveyor belt 73.

  As shown in FIGS. 5 and 6, the upper unit 71 can be moved upward so as to be separated from the lower unit 72 by a link mechanism 79 disposed between the second unit 1 b of the image forming apparatus 1. Is provided. The upper unit 71 includes a lever 791 as a positioning member for positioning at a required operation position in contact with the lower unit 72. On the other hand, the lower unit 72 has a rod 792 that is engaged with an arm member (not shown) by operating the lever 791 of the upper unit 71. Then, the distance between the axes of the first and second drive rolls 731 and 751 is fixed in a state where the upper unit 71 is positioned at a required position of the lower unit 72.

<Operation of cooling device>
Next, the operation of the cooling device of the image forming apparatus 1 will be described.

  In the cooling device 70, when the image forming apparatus 1 receives command information for requesting an image forming operation (printing), the first conveying belt 73, the second conveying belt 75, and the cooling fan 746 are started.

  As shown in FIG. 3, the recording paper 5 on which the toner images of the respective colors are fixed by the fixing device 40 is conveyed to the cooling device 70 by a conveying device 59 (see FIG. 1) in the form of a belt. Is done. In the cooling device 70, the recording sheet 5 being conveyed is sandwiched between the first conveyance belt 73 and the second conveyance belt 75, and the downstream along the moving direction of the first and second conveyance belts 73 and 75. To the side.

  Meanwhile, the recording paper 5 is sandwiched between the first and second transport belts 73 and 75 by the pressing roll 76 disposed on the inner peripheral side of the second transport belt 75, and the first transport belt 73. And pressed against the surface 741a of the heat sink 74. The heat of the recording paper 5 and the toner image fixed on the surface thereof is transferred to the heat sink 74 through the first conveying belt 73 by heat conduction, and the recording paper 5 and the toner image are cooled.

  The heat transmitted to the heat sink 74 is released into the air from the heat radiating plate 742 by the air flowing so as to pass between the heat radiating plates 742 by operating the cooling fan 746, and the heat sink 74 is cooled.

  By the way, as shown in FIG. 3, the first and second drive rolls 731 and 751 for driving the first and second transport belts 73 and 75 are disposed downstream of the heat sink 74 along the belt moving direction. The first and second conveyor belts 73 and 75 are disposed in pressure contact with each other. The recording paper 5 conveyed in a state sandwiched between the first and second conveyance belts 73 and 75 and cooled by the heat sink 74 is discharged to the outside of the cooling device 70 by the first and second conveyance belts 73 and 75. Is done. Therefore, compared with the case where the discharge rolls are provided separately from the first and second drive rolls 731 and 751, the number of parts can be reduced, and the apparatus can be reduced in size and cost.

  Further, the first and second drive rolls 731 and 751 are arranged in the belt movement direction of the heat sink 74 serving as the transport load of the first transport belt 73 and the pressing roll 76 serving as the transport load of the second transport belt 75. It is arrange | positioned at the downstream edge part along. Therefore, the first and second conveyor belts 73 and 75 can be driven from the downstream end along the moving direction, and the transportability of the first and second conveyor belts 73 and 75 is improved. Can do.

  The second driving roll 751 is pressed against the first driving roll 731 by the elastic deformation force of the elastic layer 751b, and the pressing member that presses the second driving roll 751 against the first driving roll 731. It is not necessary to provide a separate device, the structure of the apparatus can be simplified, and the apparatus can be reduced in size and cost.

  The second drive roll 751 is set to have a rotational speed equal to or higher than the rotational speed of the first drive roll 731, that is, the moving speed of the first conveyor belt 73, and the driving force is transmitted. A torque limiter 785 is attached to the means. Therefore, when the drive torque of the second drive roll 751 exceeds a required value, the torque limiter 785 is operated and the drive torque of the second drive roll 751 is limited. The first drive roller 731 is rotated at a speed equal to the rotation speed of the first drive roll 731 via the first and second conveyor belts 73 and 75. Therefore, the second drive roll 751 can be rotationally driven at a speed equal to that of the first drive roll 731 even when the elastic body layer 751b is worn by use over time. Therefore, a difference in moving speed between the first and second conveying belts 73 and 75 is suppressed, and the first and second conveying belts 73 and 75 and the recording paper 5 are stably conveyed. be able to.

  In addition, the upper unit 71 is configured to be movable in a direction in which the upper unit 71 comes into contact with and separates from the lower unit 72, and there is a problem in the conveyance of the recording paper 5 by the first and second conveyance belts 73 and 75. However, it becomes easy to cope by separating the upper unit 71 from the lower unit 72.

  In the above-described embodiment, the case where the distance between the axes of the first and second drive rolls 731 and 751 is fixed has been described. However, the pressure contact force of the first and second drive rolls 731 and 751 is secured. Thus, for example, the rotation shaft of the second drive roll 751 may be movably held by the long hole.

  Moreover, although the said embodiment demonstrated the case where it applied to a cooling device as a conveying apparatus, it is not limited to this, Other conveyance which conveys to-be-conveyed members other than a cooling device within the scope of the present invention It is also possible to apply to an apparatus.

70 ... Cooling device 73 ... 1st conveyance belt 731 ... 1st drive roll 74 ... Heat sink 75 ... 2nd conveyance belt 751 ... 2nd drive roll

Claims (7)

An endless first belt that circulates;
An endless second belt that is disposed on the outer peripheral side of the first belt, circulates and moves with the conveyed member sandwiched between the first belt, and conveys the conveyed member;
A contact member disposed on the inner peripheral side of the first belt and in contact with the transported member transported by the second belt via the first belt;
The elastic member layer provided on one side is disposed so as to be elastically deformed to the discharge portion of the transported member located on the downstream side of the contact member in the belt moving direction, and the first and second members First and second driving rotating bodies that respectively drive the belt;
A conveying apparatus comprising:   The conveying device according to claim 1, wherein the first and second driving rotating bodies are arranged in a state in which an inter-axis distance is fixed.   The conveying device according to claim 1, wherein the elastic body layer is provided on a second driving rotating body that drives the second belt.   The driving means for rotationally driving the second driving rotating body includes torque limiting means for limiting the driving torque of the second driving rotating body, and the moving speed of the second belt is the speed of the first belt. The conveying apparatus according to claim 3, wherein the conveying apparatus is set to be equal to or higher than the moving speed.   A first unit to which the first belt is attached; and a second unit to which the second belt is attached. The first unit is movable in a direction in which the first unit comes into contact with or separates from the second unit. The conveying apparatus according to claim 1, wherein the conveying apparatus is configured.   The cooling device as a transport device according to claim 1, wherein the contact member includes a cooling member that cools the transported member via the first belt. An image forming unit for forming an image on a recording medium;
Fixing means for fixing by heating a recording medium on which an image is formed by the image forming unit;
The image forming apparatus comprising the cooling device according to claim 6, wherein the recording medium on which the image is fixed by the fixing unit is cooled as the transported member.

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