JP5492673B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus including a fixing device that fixes a toner image transferred on one or both sides of a transfer material such as roll paper.

  As a configuration of an image forming apparatus including a fixing device that fixes a toner image transferred on one or both sides of a transfer material such as roll paper, there are configurations of Patent Documents 1 and 2, for example.

  This configuration is disclosed in Patent Document 1, as shown in FIGS. 1 to 4 of Patent Document 1, in which black toner 15, magenta toner 16, cyan toner 17, and yellow toner positively charged by the manufacturing devices 1, 2, 3, and 4 are used. After transferring 18 to the surface of the paper 14, toner of each color is collectively fixed to the paper 14 by the heat rolls 23 and 24.

Further, as shown in FIG. 1, Patent Document 2 discloses a heating roll 1 and a pressure roll 2 so that a toner image formed on one side of a continuous paper 4 or a toner image formed on both sides can be fixed. In the case of fixing two surfaces of the continuous paper 4 by fixing two image forming apparatuses each including a fixing device, a photoconductor 8, and a transfer device 9, the first surface is first fixed and the other surface is fixed. It will be established.
JP-A-10-207133 JP 2004-258568 A

  However, such a configuration has the following problems. Since Patent Document 1 has a configuration in which one side or both sides are fixed together, the paper 14 sent to the heat rolls 23 and 24 evaporates the moisture contained in the paper 14 due to the heat of the heat rolls 23 and 24. The sheet 14 contracts. As a result, there is a problem that the roll paper is easily pulled toward the fixing device, and the transfer position of the toner image is shifted.

  Further, as shown in FIG. 1, in Patent Document 2, when both sides of the continuous paper 4 are fixed, the toner image transferred to one side of the continuous paper 4 is continuously heated in a state where heat is accumulated. Since the toner image is transferred to the image forming apparatus that transfers the toner image to the other surface of the paper 4, the heat affects the photoconductor 8 and the devices disposed around it. As a result, for example, there is a problem that the photosensitive member or the like deteriorates relatively quickly.

  Further, as a configuration for solving the problem of Patent Document 2, it is conceivable to dispose the image forming apparatus in a sufficiently separated state (specifically, a state in which heat is removed when fixing to one side of the continuous paper 4). However, the entire apparatus becomes large.

  In order to solve the above-described problem, the present invention provides a toner on any one surface of a roll paper fed out from the feed means, the other surface of the roll paper, or both sides of the roll paper. An image forming unit for forming an image, a first fixing unit including a heating roller for fixing a toner image formed on one surface of the roll paper, and a toner image formed on the other surface of the roll paper are fixed. A fixing unit comprising a second fixing unit including a heating roller, and a conveying means for feeding out a roll paper on which the toner image is fixed by the fixing unit, the heating roller of the first fixing unit and the second fixing unit The heating roller is arranged so that the roll paper is wound around the half circumferential surface of each heating roller, and furthermore, the first fixing unit and the second fixing unit are each heated roller and a roll that substantially winds around each heating roller. Air blowing means is provided between the paper and the wind. A suction means for sucking the roll paper from each heating roller is provided on the side where the roll paper is wound around each heating roller, and the roll paper is provided with a feeding means, a first fixing portion, a second fixing portion, and a conveying means. And a release mechanism for releasing and returning the constant tension of the roll paper is provided in the transfer means.

  Further, in the invention according to claim 2, the conveying means has two or more rollers for applying a constant tension to the roll paper, and the toner image is fixed in order to wind the roll paper around one of the heating rollers. It is characterized by having a pair of conveying rollers for feeding roll paper at a constant pressure.

  Furthermore, in the invention according to claim 3, the release mechanism is provided in each heating roller, and a roller moving unit that releases and returns the heating roller to a predetermined position, and the tension of the roll paper conveyed from the fixing unit is released and A pressing unit for returning, and a roller moving unit and an interlocking unit for operating the pressing unit when the apparatus is stopped or operated, and the interlocking unit is configured to start from a predetermined position of each heating roller by the roller moving unit when the apparatus is stopped. And releasing the tension of the roll paper by the pressing portion, and operating the suction of the suction means and the blowing of the blower means.

  In the image forming apparatus of the present invention, the roll paper is transported with a constant tension by the feeding means, the first fixing section, the second fixing section, and the transport means. A release mechanism for releasing and returning the tension is provided. Based on this configuration, the first fixing unit and the second fixing unit are configured by a heating roller, and are arranged so that the roll paper is wound around the half circumferential surface of the heating roller. With this arrangement, the contact area of the roll paper with the heating roller is enlarged, and fixing can be performed reliably. In particular, the toner image transferred to the roll paper can be uniformly fixed by using the same configuration of the heating roller.

  In addition, since the contact area of the roll paper with the heating roller is enlarged, the heat of the heating roller is less likely to escape to the outside, and the temperature of the heating roller is reduced to such an extent that the transfer position of the toner image is not affected. Can be suppressed.

  Furthermore, each heating roller is provided with a blowing means, and when roll paper jam processing or the like, the roll paper wound around the heating roller is heated by feeding air between the heating roller and the roll paper wound around the heating roller. And can be easily subjected to jamming of roll paper.

  Further, the release mechanism is constituted by a roller moving unit, a pressing unit, and an interlocking unit, and a suction unit that sucks the roll paper from each heating roller is provided on the side where the roll paper is wound around each heating roller, for example, When the jamming process occurs and the device stops, the interlocking unit is actuated, the pressure roller is released from the predetermined position by the roller moving unit and the tension of the roll paper is released by the pressing unit, and the heating roller and the heating unit are heated. Air is sent between the roll paper wound around the roller and the blowing means is operated by the suction means to suck the roll paper wound around the heating roller from the heating roller. Thereby, the roll paper wound around the heating roller is more reliably separated from the heating roller, and the roll paper can be easily jammed.

1 is a schematic diagram of an image forming apparatus of the present invention. The figure which shows the detail of a fixing | fixed part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 schematically shows an image forming apparatus according to the present invention. First, the image forming apparatus of the present invention fixes a feeding unit 100 that feeds a roll paper P from a supply unit (not shown), an image forming unit 200 that transfers a toner image to the roll paper P, and a toner image transferred to the roll paper P. A fixing unit 300 that performs fixing, and a transport unit that transports the fixed roll paper P. The roll paper P is conveyed with a constant tension by the feeding unit 100, the image forming unit 200, the fixing unit 300, and the conveying unit 400.

  The feeding unit 100 includes a pair of rollers, and holds the roll paper P with a constant contact pressure so that the roll paper P does not shift or slip when the roll paper P is fed to the image forming unit 200 side. ing.

  Further, an auxiliary conveyance roller 110 is provided between the feeding unit 100 and the image forming unit 200. The auxiliary conveyance roller 110 applies a certain tension to the roll paper P that moves from the feeding means 100 to the fixing unit 300 in cooperation with the roll paper P biasing means 120 described later.

  The image forming unit 200 forms a toner image on one side of the roll paper P fed from the feeding unit 100, the other side of the roll paper P, or both sides of the roll paper P.

  More specifically, the image forming unit 200 forms a color image, and a first image forming unit 210 and a roll for forming a color image on the surface (the lower surface in the drawing) of the roll paper P. The second image forming unit 220 forms a color image on the back surface (upper surface in the drawing) of the paper P.

  Further, when the transfer is released from the transfer position of the first image forming unit 210 (the color toner (toner) image is not transferred onto the surface of the roll paper P), the roll paper P is kept in a certain tension and the auxiliary is maintained. The roller 110 is configured to be separated from the first image forming unit 210.

  As shown in the figure, the first image forming unit 210 and the second image forming unit 220 have a substantially symmetrical configuration, and the first image forming unit 210 is viewed from below with respect to the intermediate transfer belt 211. In order, black (BK), cyan (C), magenta (M), and yellow (Y) images are formed, and the color image formed on the top of the intermediate transfer belt 211 (first support means) is rolled. Transfer to the surface of the paper P.

  Further, the second image forming unit 220 forms black (BK), cyan (C), magenta (M), and yellow (Y) images on the intermediate transfer belt 221 in order from the top. An image is transferred to the back surface of the roll paper P at the lower end.

  In this embodiment, the image is formed in black (BK), cyan (C), magenta (M), and yellow (Y) in this order from the top, but is not limited to this. (Y), magenta (M), cyan (C), and black (BK) may be used.

  The photosensitive drums BK1, C1, M1, Y1 and BK2, C2, M2, Y2 that form toner images of the respective colors are the toner colors (Y, M, C, BK) used, and various set values such as charging and transfer. Except that they are different from each other, they are physically the same configuration.

  Therefore, in the following, the formation of a black image on the black toner photoconductor BK1 of the first image forming unit 210 will be described with respect to an image forming apparatus disposed around the black image photosensitive member BK1, but other photosensitive drums Y1, M1, Similar image forming devices are arranged around C1, Y2, M2, C2, and BK2.

  The photosensitive drum Y1 has a configuration in which a known photosensitive member such as an OPC photosensitive member or an amorphous silicon photosensitive member is provided on the surface of a cylindrical substrate such as aluminum, and when viewed in FIG. 1, it rotates clockwise at a predetermined speed during operation. .

  Although not shown in FIG. 1, an eraser lamp for removing residual charges on the photosensitive drum Y1 around the photosensitive drum Y1 in order of operation, a corona charger for uniformly charging the surface of the photosensitive drum Y1 to a specific polarity, An LED exposure device for forming an electrostatic latent image based on desired information by projecting a digital light signal corresponding to a black signal onto the surface of the charged photosensitive drum Y1, formed on the surface of the photosensitive drum Y1. A developing device that develops the electrostatic latent image with black toner, and transferring the toner image formed on the photosensitive drum Y1 to the surface of the intermediate transfer belt 211 by charging the toner with a reverse polarity to the toner from the back side of the intermediate transfer belt. A transfer roller (or transfer corona discharger) and a cleaner for removing toner powder remaining on the surface of the photosensitive drum Y1 after transfer are disposed.

  The photosensitive drums C1, M1, and BK1 are also provided with the eraser lamp, the corona charger, the exposure device, the developing device, the transfer roller, and the cleaner, respectively, like the photosensitive drum Y1. The photosensitive drums Y1 use exposure based on color image signals corresponding to cyan for C1, magenta for M1, and black for BK1, and toner of the corresponding color.

  Each intermediate transfer belt (211, 221) is composed of a wide endless belt, and is supported by support means (230, 240) described later. At the time of image formation, the peripheral speeds of the respective photosensitive drums BK 1, C 1, M 1, Y 1 are counterclockwise. Move at the same speed as.

  Along with this movement, a black toner image formed on the photosensitive drum BK1 on the surface of the intermediate transfer belt 211, and then a cyan toner image and a magenta toner image formed on each of the photosensitive drums C1, M1, and Y1. Then, the yellow toner images are sequentially transferred and laminated to form a full-color toner image or a multi-color toner image. In the following, a full color toner image and a multi-color toner image are referred to as toner images.

As shown in FIG. 1, the support means (230, 240) includes first support means (231, 241) and second support means (232, 242), and is provided at an interval in the vertical direction. The first support means (231, 241) is a roller. The second support means (232, 242) are two auxiliary means for applying a certain tension to the top rollers (231a, 241a) facing the first support means (231, 241) and the intermediate transfer belts (211, 221). Roller ((232a, 232b), (242a, 242b)).

  The transfer unit 212 on the first image forming unit 210 side and the transfer unit 222 of the second image forming unit 220 are connected to a bias power source (not shown), and a transfer device to which a predetermined transfer bias is applied during image formation ( Includes a transfer charger) and a peeling device (charger). Further, the transfer device (transfer charging device) and the peeling device (static charge device) on the second image forming unit 220 side include a corona wire and a corona house that covers the corona wire.

  The transfer unit 212 on the first image forming unit 210 side and the transfer unit 222 on the second image forming unit 220 side are provided with contact / separation unit 213 for retracting away from the toner carrying surface (second image). (Not shown in the transfer means on the forming unit 220 side). Specifically, the contact / separation unit 213 on the first image forming unit 210 side attaches the transfer unit 212 and each guide roller (215a, 215b) to the frame, and the frame so as to swing within a predetermined range. Is supported by a frame of a device (not shown).

  In this way, the contact / separation means 213 releases the transfer means independently or in conjunction with each other from the transfer position at which the toner image is transferred to the front and back surfaces of the roll paper P. With this configuration, either one side of the roll paper P or both sides of the roll paper P can be selected and an image can be output to the roll paper P.

  The roll paper urging unit 120 applies an appropriate tension to the roll paper P that moves between the feeding unit 100 and the fixing unit 300 to eliminate sagging of the roll paper P, and the first image forming unit 210. And the second image forming unit 220. The roll paper urging means 120 includes an arm part 121 and a frame part 122.

  A contact roller 123 is provided on one end side of the arm portion 121. On the other hand, the other end of the arm part 121 is attached to the frame part 122. As described above, the frame portion 122 covers the side plate 122a attached to the frame of the apparatus (not shown), the top plate 122b that covers the upper surface of the side plate 122a and bridges between the side plates 112a, and the side plate 112a. The fixed roller 122c.

  The fixing unit 300 fixes the color toner image (toner image) transferred on one side of the roll paper P or both sides of the roll paper P by the image forming unit 200. Specifically, as shown in FIG. 2, the fixing unit 300 includes a first fixing unit 310, a second fixing unit 320, and a transport unit 400. The roll paper P onto which the toner image has been transferred is conveyed with a constant tension by the first fixing unit 310, the second fixing unit 320, and the conveying unit 400.

  The fixing unit 300 includes a first fixing unit 310 that fixes the toner image transferred onto the surface of the roll paper P, and a second fixing unit 320 that fixes the toner image transferred onto the back surface of the roll paper P. The Further, the first fixing unit 310 and the second fixing unit 320 are made of a cylindrical tube made of, for example, aluminum having good thermal conductivity, and heating means (311 and 321) such as an infra red lamp (or halogen lamp) are provided inside. The outer periphery is composed of heating rollers (310, 320) on which a Teflon (registered trademark) film is formed. The first fixing unit 310 and the second fixing unit 320 are respectively provided in a roller moving unit 510 constituting a release mechanism 500 described later.

  The first fixing unit 310 and the second fixing unit 320 are arranged so that the roll paper P2 is wound around the substantially half circumference. With this arrangement, the contact area between the roll paper P and each fixing unit 300 is increased as compared with the fixing devices described in Patent Document 1, Patent Document 2, and the like, and the heat of the heating unit 311 is efficiently fixed. Can be used.

  Further, since the fixing devices described in Patent Document 1, Patent Document 2, and the like are fixed between the nips of the rollers, the heat of the heating unit 311 escapes from the periphery of each fixing unit 300 other than the nip portion to the outside. Therefore, in these configurations of Patent Documents 1 and 2, etc., in order to keep the temperature in the heating roller constant, it is necessary to set the heat of the heating temperature higher than necessary.

  As a result, the temperature between the nips of the rollers becomes higher than necessary, and the moisture of the roll paper P evaporates more than necessary during fixing, and the transfer position of the toner image is shifted. In this regard, according to the present invention, since the roll paper P is wound around the substantially half circumference of each heating roller (312, 322), and the contact area between the roll paper P and each fixing unit 300 increases, Patent Document 1, Patent Document 2, and the like The temperature of the heating rollers (312 and 322) can be suppressed from shrinkage to such an extent that the temperature does not affect the transfer position of the toner image.

  Further, around each of the first fixing unit 310 and the second fixing unit 320, a release agent supply device 800, a blowing unit 600, and a suction unit 700 are provided. The release agent supply device 800 removes residues such as toner adhering to the surface of the heating roller (312, 322) and applies the release agent to the surface of the heating roller (312, 322).

  As shown in FIG. 2, the release agent supply device 800 is detachably provided on the roller moving unit 510, and the first fixing unit 310, the second fixing unit 320, and the respective release agent supply devices 800 corresponding thereto are provided. It is unitized.

  Specifically, the release agent supply device 800 includes a web 810 that contacts the circumferential surface of the heating roller (312 and 322), a feeding roller that feeds the web 810 along the heating roller (312 and 322), and a feeding roller. A winding roller for winding the fed web 810 and pressing means for pressing the web 810 against the peripheral surface of the heating rollers (312, 322) are provided (reference numerals are omitted). The web 810 is a non-woven belt-like material and is impregnated with a release agent in advance.

  When the apparatus is stopped, the blowing unit 600 sends air between the heating rollers (312 and 322) (first fixing unit 310 and second fixing unit 320) and the roll paper P, and the heating rollers (312 and 322). Separating roll paper P adsorbed on the surface of (first fixing unit 310, second fixing unit 320) from the surface of heating rollers (312, 322) (first fixing unit 310, second fixing unit 320) It is.

  With this configuration, the heating rollers (312 and 322) (first fixing unit 310, second fixing unit 320) and the heating rollers (312 and 322) (first fixing unit 310) are used for jam processing of the roll paper P. The roll paper P wound around the heating rollers 312 and 322 (the first fixing unit 310 and the second fixing unit 320) by sending air between the roll paper P and the roll paper P wound around the second fixing unit 320). Is separated from the heating rollers (312, 322) (first fixing unit 310, second fixing unit 320), and the jam treatment of the roll paper P can be easily performed.

  The suction means 700 sucks the roll paper P from the heating rollers (312 and 322) when the apparatus is stopped, and is provided on the side where the roll paper P is wound around each heating roller (312 and 322). Yes. By the suction unit 700 and the blowing unit 600, the roll paper P wound around the first fixing unit 310 and the second fixing unit 320 can be efficiently separated.

  In order to wind the roll paper P around one of the heating rollers (312 and 322), the transport unit 400 includes two or more rollers 410 that apply a certain tension to the roll paper P, and a roll on which the toner image is fixed. It comprises a pair of conveying rollers 420 that feeds the paper P at a constant pressure.

  The release mechanism 500 releases the tension acting on the roll paper P when the apparatus is stopped. The release mechanism 500 includes a roller moving unit 510, a pressing unit 520, and an interlocking unit 530.

  The roller moving unit 510 releases and returns the first fixing unit 310 and the second fixing unit 320 to predetermined positions. Specifically, the roller moving unit 510 houses the first fixing unit 310 and the second fixing unit 320, respectively. The frame 511, a slide rail 512 for moving the frame 511, and a biasing means 513 attached to the frame 511 and biasing the first fixing unit 310 and the second fixing unit 320 in a predetermined direction. .

  The slide rail 512 is provided in a housing of a device (not shown) and guides 514 that guides the movement of the frame 511 in a predetermined direction, and a guide receiver that is provided on the frame 511 and moves the frame 511 along the guide 514. 515. The urging means 513 always acts in the direction in which the frame body 511 moves to the side opposite to the direction in which the roll paper P and the heating rollers (312 and 322) are in contact with each other. For this reason, during operation of the apparatus, each heating roller (312 and 322) is fixed at a predetermined position by an interlocking unit 530 described later.

  The pressing unit 520 releases and restores the tension of the roll paper P conveyed from the fixing unit 300, and is provided on a roller 410 disposed on the conveying roller pair 420 side. Specifically, the pressing portion 520 includes an attachment portion 521 that pivotally supports the roller 410, a second guide portion 514 that guides the movement of the roller 410 in a certain direction, and a rapid movement of the roller when the tension of the roll paper P is released. And a brake 523 for preventing a serious movement. In addition, the pressing unit 520 is provided with a regulating unit (not shown) for preventing unnecessary pressing and dropping of the roll paper P.

  The brake 523 includes a one-way clutch 524 provided with an elastic body such as rubber on the peripheral surface, and a damper roller 525 provided with an elastic body such as rubber on the peripheral surface in the same manner as the one-way clutch 524. The one-way clutch 524 is configured not to rotate when the elastic body presses against the attachment portion 521 and the attachment portion 521 shifts downward. This prevents a sudden downward shift of the mounting portion 521. Further, the damper roller 525 is disposed so as to press against the elastic body of the one-way clutch 524, and the action and effect of the brake 523 is enhanced.

  The attachment portion 521 is a thin metal plate formed in a frame shape, and a rack for transmitting the drive of the interlocking portion 530 described later to the attachment portion 521 is provided. Furthermore, both sides of the attachment portion 521 are formed so as to fit into the second guide portion. Further, the brake 523 is configured to abut against the attachment portion 521, and when the action of the interlocking portion 530 described later is released, the brake 523 receives the weight of the attachment portion 521 and moves the attachment portion 521 slowly.

  Note that the degree of “slow”, that is, slowly moving, specifically, when the action of the interlocking portion 530 is released and the attachment portion 521 is shifted downward as shown in FIG. That is, the degree of collision with a not-shown restricting part does not produce a large collision sound. With this configuration, the weight of the mounting portion 521 prevents the mounting portion 521 from colliding with a restriction portion (not shown) in a state where the weight of the mounting portion 521 is applied, and prevents damage to the mounting portion 521 or the restriction portion. Can do.

  The interlocking unit 530 is provided in each of the frame body 511 of the first fixing unit 310, the frame body 511 of the second fixing unit 320, and the pressing unit 520, and each heating roller (312, 322) when the apparatus is stopped or operated. ) And the mounting portion 521 are released and returned to a predetermined position. The interlocking unit 530 includes a driving unit 531 and a transmission unit 532.

  The drive unit 531 serves as a power source for releasing and returning the heating rollers (312 and 322) and the attachment unit 521 to predetermined positions. Specifically, the drive unit 531 is a motor including a drive shaft 533. The transmission unit 532 transmits the driving of each driving unit 531 to the heating rollers (312 and 322) and the mounting unit 521 corresponding to each driving unit 531, and a driving gear 534 attached to the driving shaft 533 and , And a clutch gear 535.

  The clutch gear 535 contacts and separates the drive transmission of the drive unit 531 with respect to the guide receiving unit 515 of the first fixing unit 310, the guide receiving unit 515 of the second fixing unit 320, and the rack of the mounting unit 521. . Note that the clutch gear 535 is brought into and out of contact with a control means (not shown) that detects that the apparatus has been stopped or operated.

  Based on the above configuration, the operation of the present invention will be described. First, when the control means determines that the apparatus has stopped due to a jam or the like of the roll paper P, the control means activates the clutch gear 535 of the mounting portion 521 to cut off the drive transmission from the drive source. By shifting the transmission of the driving force of the driving source, it shifts downward due to the weight of the mounting portion 521. At this time, the shift of the attachment portion 521 slowly moves downward until it hits a restriction portion (not shown) by the action of the brake 523.

  Although not described in this embodiment, during the above-described operation, the auxiliary roller 110 is separated from the first image forming unit 210, and the transfer unit on the second image forming unit 220 side is set to a predetermined position. It is separated from the position. Accordingly, the roller pivotally supported by the attachment portion 521 is also shifted downward from the predetermined position, the state where the pressing portion 520 is pressed against the roll paper P is released, and the tension of the roll paper P is released. Further, the state in which the roll paper P is wound around each heating roller (312, 322), that is, the first fixing unit 310 and the second fixing unit 320, is slightly loosened.

  Further, after the above operation or substantially simultaneously, the clutch gear 535 of the first fixing unit 310 and the clutch gear 535 of the second fixing unit 320 are turned off. Each clutch gear 535 does not transmit the driving force of the driving source corresponding to the clutch gear 535. At this time, each of the frame body 511 of the first fixing unit 310 and the frame body 511 of the second fixing unit 320 works in the direction opposite to the direction in which the roll paper P is wound (arrow method). . By this action, the frame body 511 moves along the slide rail 512 until it comes into contact with the restricting portion.

  By this movement, the heating rollers (312 and 322) provided in the first fixing unit 310 and the second fixing unit 320 are released from predetermined positions, and the tension of the roll paper P is reliably released. Further, when the movement of the heating roller (312, 322) starts or during the movement, or when the drive of the clutch gear 535 of the mounting portion 521 is turned off, the blowing unit 600 and the suction unit 700 are operated.

  The air blowing means 600 sends air between the wound heating rollers (312 and 322) and the roll paper P, and the suction means 700 winds the portion of the roll paper P wound around the heating rollers (312 and 322). The roll paper P is separated from the heating rollers (312 and 322).

  While the air blowing means 600 and the suction means 700 are operating, the heating roller (312 and 322) does not apply tension to the roll paper P from the predetermined position where the roll paper P is wound by the biasing force of the biasing means 513. Since it moves to the position, the roll paper P is easily sucked into the suction means 700.

  The roll paper P separated from the heating rollers (312, 322) is removed from the apparatus, and the jam processing is completed. Thereafter, the roll paper P is again passed over the respective heating rollers (312 and 322) and the conveyance roller, and the drive transmission of the drive unit 531 is connected by the clutch gear 535 to operate the drive unit 531.

  At substantially the same time, the control unit connects the clutch gears 535 of the first fixing unit 310 and the second fixing unit 320 to the driving gear 534 so that the driving of the driving unit 531 is transmitted to the frame body 511. When each drive unit 531 is driven, the drive is transmitted to the drive gear 534 and the clutch gear 535.

  This transmission is performed until the frame body 511 is moved from the rotational motion to the linear motion by the rack and the heating rollers (312 and 322) return to the predetermined position. By this operation, the pressing unit 520, the first fixing unit 310, and the second fixing unit 320 are returned to predetermined positions, and a tension is applied to the roll paper P.

100 Feeding unit 200 Image forming unit 300 Fixing unit 400 Conveying unit 500 Release mechanism 600 Blower unit 700 Suction unit P Roll paper

Claims (3)

A feeding unit that feeds the roll paper; and an image forming unit that forms a toner image on one of the one side of the roll paper fed from the feeding unit, the other side of the roll paper, or both sides of the roll paper; A first fixing unit including a heating roller for fixing the toner image formed on one side of the roll paper, and a heating roller for fixing the toner image formed on the other side of the roll paper. A fixing unit composed of two fixing units, and a conveying unit for feeding out the roll paper on which the toner image is fixed by the fixing unit,
The heating roller of the first fixing unit and the heating roller of the second fixing unit are arranged so that the roll paper is wound around the half circumferential surface of each heating roller,
Furthermore, the first fixing unit and the second fixing unit are provided with a blowing unit that sends air between the heating rollers and the roll paper that is substantially wound around the heating rollers,
Suction means for sucking the roll paper from each heating roller is provided on the side where the roll paper is wound around each heating roller,
The roll paper is conveyed with a constant tension by the feeding unit, the first fixing unit, the second fixing unit, and the conveying unit,
The image forming apparatus according to claim 1, wherein the transport unit is provided with a release mechanism for releasing and returning a constant tension of the roll paper.   In order to wrap the roll paper around one of the heating rollers, the transport unit is configured to fix two or more rollers that apply a constant tension to the roll paper and the roll paper on which the toner image is fixed. The image forming apparatus according to claim 1, further comprising a pair of conveying rollers that are fed by pressure. The release mechanism is provided in each of the heating rollers, and a roller moving unit that releases and returns the heating roller to a predetermined position; a pressing unit that releases and returns the tension of the roll paper conveyed from the fixing unit; When the apparatus is stopped or operated, the roller moving unit and the interlocking unit that operates the pressing unit are provided.
The interlocking unit releases the heating roller from a predetermined position by the roller moving unit and releases the tension of the roll paper by the pressing unit when the apparatus is stopped, and sucks the suction unit and blows the unit. The image forming apparatus according to claim 1, wherein the air blowing is activated.

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