JP2019113741A - Medium support device and image formation apparatus - Google Patents

Abstract

To suppress a speed difference from being generated between a continuous medium and a rotary body that the medium contacts as compared with a case in which a support member is fixedly arranged.SOLUTION: An intermediate transfer belt is extended among a plurality of rolls to rotate at a constant speed. A secondary transfer device is arranged to contact and leave the intermediate transfer belt across continuous paper. When the secondary transfer device contacts the intermediate transfer belt, the intermediate transfer belt and secondary transfer device vary in speed with the extension state of the continuous paper. A pulley roll 65 which supports the continuous paper with a constant load is arranged upstream from the secondary transfer device in a moving direction of the continuous paper so as to suppress the speed variation when the secondary transfer device contacts the intermediate transfer belt.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a medium support device and an image forming apparatus.

  Conventionally, as an image forming apparatus, an apparatus configured to form an image on a so-called web such as continuous paper as a recording medium has already been disclosed as a recording medium in order to meet diversification of needs of users.

  Patent Document 1 discloses a feed spool, a winding spool, a winding motor operatively connected to the winding spool, a winding control system for controlling the torque of the winding motor, and the feed spool. And a drive roller system disposed between the take-up spool, and a drive motor operatively connected to the drive roller system, and in use, the take-up motor using the take-up control system The webs supplied from the drive roller system to the take-up spool can be maintained under substantially constant tension by adjusting the torque of.

Japanese Patent Application Publication No. 2009-507681

  An object of the present invention is to suppress the occurrence of a speed difference between a continuous medium and a rotating body with which the medium contacts, as compared with the case where the support member is fixedly arranged.

  In addition, the object of the present invention is to suppress the occurrence of the speed difference between the continuous recording medium and the image carrier or the transfer means with which the recording medium is in contact as compared with the case where the support member is fixed and disposed. It is to do.

The invention described in claim 1 is a first rotating body moving at a constant speed,
A second rotor that contacts and separates from the first rotor via a medium continuous with the first rotor;
A support member disposed on the upstream side along the moving direction of the medium of the second rotating body, and supporting the medium with a constant load;
A media support device.

  In the invention described in claim 2, the support member is mounted on a first arm member rotatable around a fulcrum, and the first arm member is given an elastic force by a first elastic member. The medium support device according to claim 1.

  In the invention described in claim 3, the support member is arranged at a first position spaced apart from the first rotating body and at a second position closer to the first rotating body than the first position, the first arm The medium support apparatus according to claim 2, wherein the medium support is movable by a first eccentric cam that rotates the member.

  The invention described in claim 4 is the medium support device according to claim 3, wherein the support member is switched from constant displacement to constant load when moving from the first position to the second position.

  In the invention described in claim 5, the second rotating member is mounted on a second arm member rotatable around a fulcrum, and the second arm member is a first elastic member by a second elastic member. The medium support device according to claim 1, wherein an elastic force in the direction of pressing against the rotating body is applied.

  In the invention described in claim 6, the second rotating body is connected to a third position spaced from the first rotating body, and a fourth position in which the second rotating body is in contact with the first rotating body via a continuous medium. 6. The medium support device according to claim 5, wherein the medium support device is movable by a second eccentric cam that rotates the second arm member to a fifth position in pressure contact with the first rotating body via a medium.

  The invention recited in claim 7 is any one of claims 1 to 6, further comprising a second support member disposed downstream of the second rotating body along the moving direction of the medium and supporting the medium. It is a medium support apparatus as described.

According to an eighth aspect of the present invention, there is provided an image carrier which holds a toner image and moves at a constant speed.
A transfer unit that contacts and separates from the image carrier via a recording medium continuous with the image carrier and transfers the toner image held by the image carrier to the recording medium;
A support member disposed upstream of the transfer means along the direction of movement of the recording medium and supporting the recording medium with a constant load;
An image forming apparatus comprising:

  In the invention described in claim 9, the support member is mounted on a first arm member rotatable around a fulcrum, and the first arm member is given an elastic force by a first elastic member. The image forming apparatus according to claim 8.

  In the invention described in claim 10, the support member has the first arm member at a first position spaced from the image carrier and at a second position closer to the image carrier than the first position. The image forming apparatus according to claim 9, wherein the image forming apparatus is movable by a first eccentric cam that is rotated.

  In the invention described in claim 11, the second rotary member is mounted on a second arm member rotatable around a fulcrum, and the second arm member holds the image by a second elastic member. The image forming apparatus according to claim 8, wherein an elastic force is applied in a direction in which the body is in pressure contact.

  In the invention described in claim 12, the transfer means comprises a third position spaced from the image carrier, a fourth position in contact with the image carrier via a recording medium connected to the image carrier, and the image carrier 12. The image forming apparatus according to claim 11, wherein the image forming apparatus is movable by a second eccentric cam that rotates the second arm member to a fifth position in pressure contact via a continuous recording medium.

  The invention recited in claim 13 is any one of claims 8 to 12, further comprising a second support member disposed downstream of the transfer means along the direction of movement of the recording medium and supporting the recording medium. It is an image forming apparatus as described.

According to a fourteenth aspect of the present invention, there is provided an intermediate transfer member to which the toner image is transferred from a plurality of image forming means for forming toner images of different colors.
A secondary transfer unit that transfers the toner image transferred to the intermediate transfer body to a continuous recording medium;
Contact and separation means for causing the secondary transfer means to contact and separate from the image carrier via the recording medium;
A support member disposed upstream of the secondary transfer means along the direction of movement of the recording medium and supporting the recording medium with a constant load;
An image forming apparatus comprising:

  In the invention described in claim 15, the support member is mounted on a first arm member rotatable about a fulcrum, and the first arm member is given an elastic force by a first elastic member. The image forming apparatus according to claim 14.

  The invention described in claim 16 is that the support member has the first arm member at a first position separated from the intermediate transfer body and a second position closer to the intermediate transfer body than the first position. The image forming apparatus according to claim 15, wherein the image forming apparatus is movable by a first eccentric cam that is rotated.

  The invention described in claim 17 is the image forming apparatus according to claim 16, wherein the support member is switched from constant displacement to constant load when moving from the first position to the second position.

  In the invention described in claim 18, the secondary transfer means is mounted on a second arm member rotatable about a fulcrum, and the second arm member is the intermediate transfer member by a second elastic member. The image forming apparatus according to claim 14, wherein an elastic force is applied in a direction in which the body is in pressure contact.

  According to a nineteenth aspect of the present invention, in the intermediate transfer member, the secondary transfer unit may contact a third position spaced from the intermediate transfer member, a fourth position in contact with the intermediate transfer member via a recording medium, and the intermediate position. 19. The image forming apparatus according to claim 18, wherein the image forming apparatus is movable by a second eccentric cam that rotates the second arm member to a fifth position in pressure contact with a transfer medium via a recording medium.

  The invention recited in claim 20 is any one of claims 14 to 19, further comprising a second support member disposed downstream of the secondary transfer means along the moving direction of the medium and supporting the recording medium. The image forming apparatus according to

  According to the first aspect of the present invention, compared to the case where the support member positioned on the upstream side along the moving direction of the continuous medium of the second rotating body is fixed and disposed, the continuous medium and the relevant medium It is possible to suppress the occurrence of the speed difference between the medium and the rotating body with which it contacts.

  According to the second aspect of the present invention, the support member is mounted on the first arm member rotatable around the fulcrum, and the first arm member is given elastic force by the first elastic member. The configuration for supporting the support member can be simplified as compared to the case where it is not used.

  According to the third aspect of the present invention, the support member can be reliably moved to the first position and the second position by rotating the first arm member with the first eccentric cam.

  According to the invention described in claim 4, when the support member is moved from the first position to the second position, the constant load can be reliably switched.

  According to the fifth aspect of the present invention, the second rotating member is mounted on the second arm member rotatable about the fulcrum, and the second arm member is formed of the second elastic member by the second elastic member. The configuration for supporting the second rotating body can be simplified as compared to the case where the elastic force in the direction of pressing against the one rotating body is not applied.

  According to the invention described in claim 6, by rotating the second arm member by the second eccentric cam, it is possible to reliably move the second rotating body from the third position to the fifth position.

  According to the invention described in claim 7, in comparison with the case where the second support member disposed on the downstream side along the moving direction of the medium of the second rotating body and supporting the medium is not provided, The angle at which the medium separates from the first rotating body can be changed according to the type of medium.

  According to the invention described in claim 8, the continuous recording medium and the recording are compared as compared to the case where the support member positioned on the upstream side along the moving direction of the continuous medium of the transfer means is fixedly arranged. It is possible to suppress the occurrence of a speed difference between the medium and the image carrier or transfer means with which it comes in contact.

  According to the invention described in claim 9, the support member is mounted on the first arm member rotatable about the fulcrum, and the first arm member is given elastic force by the first elastic member. The configuration for supporting the support member can be simplified as compared to the case where it is not used.

  According to the tenth aspect of the present invention, the support member can be reliably moved to the first position and the second position by rotating the first arm member by the first eccentric cam.

  According to the invention described in claim 11, the transfer means is mounted on the second arm member rotatable around the fulcrum, and the second arm member is the image carrier by the second elastic member. The configuration for supporting the transfer means can be simplified as compared with the case where no elastic force in the direction of pressure contact is applied.

  According to the twelfth aspect of the present invention, the second rotary member can be reliably moved from the third position to the fifth position by rotating the second arm member with the second eccentric cam.

  According to the invention described in claim 13, as compared with the case where the transfer means is disposed on the downstream side along the moving direction of the recording medium and does not have the second support member for supporting the recording medium, The angle at which the recording medium is separated from the image carrier can be changed according to the type of recording medium.

  According to the invention described in claim 14, as compared with the case where the support member positioned on the upstream side along the moving direction of the continuous medium of the secondary transfer means is fixedly arranged, the continuous recording medium is obtained It is possible to suppress the occurrence of a speed difference between the recording medium and the intermediate transfer member or the secondary transfer unit with which the recording medium contacts.

  According to the invention described in claim 15, the support member is attached to the first arm member rotatable around the fulcrum, and the first arm member is given elastic force by the first elastic member. The configuration for supporting the support member can be simplified as compared to the case where it is not used.

  According to the invention described in claim 16, the support member can be reliably moved to the first position and the second position by rotating the first arm member with the first eccentric cam.

  According to the invention described in claim 17, when the support member is moved from the first position to the second position, the constant load can be reliably switched.

  According to the eighteenth aspect of the present invention, the transfer means is mounted on the second arm member rotatable around the fulcrum, and the second arm member is the image carrier by the second elastic member. The configuration for supporting the transfer means can be simplified as compared with the case where no elastic force in the direction of pressure contact is applied.

  According to the nineteenth aspect, by rotating the second arm member by the second eccentric cam, the second rotating body can be reliably moved from the third position to the fifth position.

  According to the invention described in claim 20, as compared with the case where the transfer means is disposed on the downstream side along the moving direction of the recording medium and does not have the second support member for supporting the recording medium, The angle at which the recording medium is separated from the image carrier can be changed according to the type of recording medium.

FIG. 1 is a schematic configuration view showing an image forming apparatus to which a medium support device according to Embodiment 1 of the present invention is applied. FIG. 1 is a configuration diagram showing an image forming unit of an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is a configuration diagram showing a secondary transfer device of the image forming apparatus according to Embodiment 1 of the present invention. FIG. 1 is a perspective view of a medium supporting device according to a first embodiment of the present invention. FIG. 1 is a perspective view of a medium supporting device according to a first embodiment of the present invention. It is a block diagram which shows a 1st support arm. It is a block diagram which shows a 2nd support arm. It is a block diagram which shows a drive arm. It is a block diagram which shows operation | movement of a 2nd support arm. It is a block diagram which shows operation | movement of a 1st support arm. FIG. 6 is a configuration diagram showing an operation of the medium support device according to Embodiment 1 of the present invention. It is a block diagram which shows operation | movement of a 1st support arm. FIG. 6 is a configuration diagram showing an operation of the medium support device according to Embodiment 1 of the present invention. FIG. 6 is a configuration diagram showing an operation of the medium support device according to Embodiment 1 of the present invention. It is a block diagram which shows the medium support apparatus which concerns on Embodiment 2 of this invention. It is a schematic block diagram which shows the image forming apparatus to which the medium support apparatus concerning Embodiment 3 of this invention is applied. It is a block diagram which shows the principal part of the medium support apparatus which concerns on Embodiment 3 of this invention. FIG. 14 is a configuration diagram showing an operation of an image forming apparatus to which a medium support device according to Embodiment 3 of the present invention is applied. It is a schematic block diagram which shows the image forming apparatus to which the medium support apparatus concerning Embodiment 4 of this invention is applied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment
1 and 2 show an image forming apparatus to which the medium supporting device according to the first embodiment is applied. FIG. 1 shows an outline of the whole of the 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, for example, a color printer. The image forming apparatus 1 includes an image output device 2 that forms an image using five color toners of yellow (Y), magenta (M), cyan (C), black (K), and special color (# 1); A feeder 3 for feeding a continuous paper (web) 5 as an example of a continuous recording medium; a discharger 4 for discharging and storing the continuous paper 5 on which an image is formed by the image output device 2; The control device 100 is provided on the upper side and controls the image output device 2, the supply device 3, and the discharge device 4.

  The image output device 2 includes an electrophotographic image forming unit 106 that forms an image on the continuous paper 5 based on image information. The image forming unit 106 holds a plurality of image forming apparatuses 10 as an example of an image forming unit for forming a toner image to be developed with toner constituting a developer and a toner image formed by each image forming apparatus 10 And an intermediate transfer device 20 for conveying to a secondary transfer position where secondary transfer is finally performed on the continuous paper 5, and fixing means for fixing the toner image on the continuous paper 5 secondary transferred by the intermediate transfer device 20. And a conveying device 60 as an example of conveying means for conveying the required continuous paper 5 to be supplied to the secondary transfer position of the intermediate transfer device 20.

  The image output device 2 can be configured as a color copier, for example, when an image reading device as an image reading unit (not shown) for inputting a document image to be formed on the continuous paper 5 is additionally provided. In FIG. 1, reference numeral 2a denotes an apparatus main body of the image output apparatus 2, and the apparatus main body 2a is composed of a supporting component, an exterior cover, and the like.

  The imaging device 10 is a five imaging device 10 Y, which exclusively forms five color toner images of yellow (Y), magenta (M), cyan (C), black (K) and special color (# 1), respectively. 10 M, 10 C, 10 K, and 10 # 1 are configured. These five image forming devices 10 (Y, M, C, K, # 1) are arranged in a line in the internal space of the device body 2a of the image output device 2.

  The toner used in the special color (# 1) image forming apparatus 10 # 1 is not particularly limited, and, for example, metal toner such as gold or silver or transparent toner, or foam toner or white toner Etc. are optional.

  As shown in FIG. 2, each image forming apparatus 10 includes a photosensitive drum 11 as an example of a rotating image carrier, and the following apparatuses are mainly disposed around the photosensitive drum 11. Is located in The main devices are a charging device 12 for charging the peripheral surface (image holding surface) of 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 Exposure device 13 as an example of an electrostatic latent image forming unit that forms an electrostatic latent image (for each color) having a potential difference by irradiating a laser beam LB based on the signal) and the corresponding color of the electrostatic latent image A developing device 14 as an example of developing means for developing the toner with a developer toner to form a toner image, a primary transfer device 15 for transferring each toner image to the intermediate transfer device 20, and a photosensitive drum 11 after the primary transfer. The drum cleaning device 16 or the like removes and cleans up the adhering substance such as toner remaining on the image holding surface of the toner.

  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 cylindrical base material to be grounded. The photosensitive drum 11 is supported so as to rotate in the direction indicated by the arrow A when power is transmitted from a driving device (not shown).

  The charging device 12 is configured of a non-contact charging device such as a corona discharger disposed in a state of not contacting the photosensitive drum 11. The charging device 12 is supplied with a charging voltage. When the developing device 14 performs reversal development as the charging voltage, a voltage or current of the same polarity as the charging polarity of the toner supplied from the developing device 14 is supplied. Of course, as the charging device 12, a contact type charging device such as a charging roll disposed in contact with the photosensitive drum 11 may be used.

  The exposure device 13 irradiates the peripheral surface of the photosensitive drum 11 after being charged with a laser beam LB configured according to the information of the image input to the image output device 2 to generate an electrostatic latent image. It forms. When it is time to form a latent image, information (signals) of an image processed by an image processing unit (not shown) is transmitted to the exposure device 13 by an arbitrary means. Image information to be subjected to image processing in the image processing unit includes full-color images of yellow (Y), magenta (M), cyan (C) and black (K) including the image of the special color (# 1) Used. The exposure device 13 emits light corresponding to image information to the photosensitive drum 11 by means of LEDs (Light Emitting Diodes) as a plurality of light emitting elements arranged along the axial direction of the photosensitive drum 11. An LED print head or the like that forms an electrostatic latent image may be used.

  Each developing device 14 holds the developer 4 and transports it to the developing area facing the photosensitive drum 11 in the developing device main body 140 in which the opening and the developer storage chamber are formed; The amount (layer thickness) of the developer 4 held by the developing roller 141 and the stirring and feeding members 142 and 143 such as two screw augers and the like that transport the developer 4 to be supplied to the developing roller 141 while stirring the developer 4 It is configured by arranging a layer thickness regulating member 144 or the like to regulate. The developing device 14 is supplied with a bias voltage for development between a developing roller 141 and the photosensitive drum 11 from a power supply device (not shown). Further, the developing roller 141, the stirring supply member 142, and the stirring conveyance member 143 are rotated in a predetermined direction by transmitting power from a rotation driving device (not shown). As the developer 4, for example, a two-component developer containing nonmagnetic toner and magnetic carrier is used.

  The primary transfer device 15 is a contact type transfer device provided with a primary transfer roll that contacts and rotates with the intermediate transfer belt 21 interposed on the circumferential surface of the photosensitive drum 11 and is supplied with a primary transfer voltage. As the primary transfer voltage, a direct current voltage having a polarity opposite to the charge polarity of the toner is supplied from a power supply (not shown).

  The drum cleaning device 16 is disposed so as to come into contact with the container-like main body 160 which is partially open and the circumferential surface of the photosensitive drum 11 after the primary transfer with a required pressure, and removes deposits such as residual toner. A cleaning plate 161 to be cleaned, and a cleaning brush 162 arranged to be in contact with the peripheral surface of the photosensitive drum 11 after the primary transfer and rotated by a required pressure, and scraping and cleaning off deposits such as residual toner; The cleaning plate 161 and the collection member 163 and the like for collecting the deposits removed by the cleaning brush 162 are included.

  The intermediate transfer device 20 is disposed below the image forming devices 10 (Y, M, C, K, # 1), as shown in FIG. This intermediate transfer device 20 is an intermediate transfer member (a first rotating member) that rotates in the direction indicated by the arrow B while passing through the primary transfer position between the photosensitive drum 11 and the primary transfer device 15 (primary transfer roll). An intermediate transfer belt 21 as an example of an image carrier, a plurality of belt support rolls 22 to 26 rotatably holding the intermediate transfer belt 21 in a desired state from its inner periphery, and a belt support roll 25 An example of a secondary transfer unit, which is a second rotating member arranged on the outer peripheral surface (image holding surface) side of the supported intermediate transfer belt 21 to secondarily transfer the toner image on the intermediate transfer belt 21 onto the continuous paper 5 Secondary cleaning device 30 and belt cleaning device 27 that removes and removes extraneous matter such as toner and paper dust remaining on the outer peripheral surface of the intermediate transfer belt 21 after passing through the secondary transfer device 30. Constitution It has been.

  As the intermediate transfer belt 21, for example, an endless belt made of a material in which a resistance regulator such as carbon black is dispersed in a synthetic resin such as a polyimide resin or a polyamide resin is used. Further, the belt support roll 22 is configured as a drive roll, the belt support rolls 23, 24 are configured as an facing roll of the intermediate transfer belt 21, and the belt support roll 25 is configured as a secondary transfer backup roll. The reference numeral 26 denotes a back support roll of the belt cleaning device 27. The intermediate transfer belt 21 is driven at a constant rotational speed by a belt support roll 22 functioning as a drive roll. The intermediate transfer belt 21 may be driven at a constant rotational speed, and a plurality of different rotational speeds may be set according to the image forming mode or the like.

  As shown in FIG. 1, the secondary transfer device 30 has an intermediate transfer belt 21 at a secondary transfer position T2 which is an outer peripheral surface portion of the intermediate transfer belt 21 supported by the belt support roll 25 in the intermediate transfer device 20. The contact type transfer device is provided with a secondary transfer belt 31 which is rotated by being driven by a secondary transfer roll 32 and a driven roll 33 which are rotated in contact with the circumferential surface of the belt and supplied with a secondary transfer voltage. Further, to the secondary transfer roll 32 or the belt supporting roll 25 of the intermediate transfer device 20, a direct current voltage having a polarity opposite to or the same as the charging polarity of the toner is supplied as a secondary transfer voltage. As will be described later, the secondary transfer device 30 is in a direction to contact and separate the intermediate transfer belt 21 supported by the belt support roll 25 at a required timing by the medium support device 80 (see FIGS. 4 and 5). It is configured to be movable. The secondary transfer device 30 and the medium support device 80 will be described in detail later.

  Fixing device 40 is heated by a heating means so that the surface temperature is maintained at a predetermined temperature in a housing (not shown) having an inlet for introducing continuous paper 5 and a delivery opening for delivering continuous paper 5. A heating rotary body 41 in the form of a roll or a belt, and a pressure rotary body 42 in the form of a roll or a belt that rotates in contact with the heating rotary body 41 at a required pressure It is. In this fixing device 40, a fixing processing unit (nip performing a necessary fixing process (heating and pressing) including a heating process in which the contact portion where the heating rotary body 41 and the pressure rotary body 42 contact contact the continuous paper 5) Part). The pressurizing rotary body 42 is configured to be movable in a direction in which it contacts or separates from the heating rotary body 41 by contact / separation means (not shown) at a required timing.

  The conveyance device 60 includes a supply device 3 for supplying the continuous paper 5, a discharge device 4 for discharging the continuous paper 5, and further, conveyance rolls 62 to 69 for conveying the continuous paper 5 inside the image output device 2. ing.

  The feeding device 3 includes a feeding roll 61 in which a long continuous paper 5 made of plain paper as an example of a continuous medium is wound in a roll. The supply roll 61 is driven at a required rotational speed in the clockwise direction in the drawing by drive means (not shown). The continuous paper 5 is supplied from a supply roll 61. The continuous medium is not limited to the continuous paper 5 made of plain paper, and a continuous synthetic resin thin film or sheet, or a material made of another material such as continuous label paper may be used.

  The feeding device 3 includes transport rolls 62 and 63 for transporting the continuous paper 5 from the feeding roll 61 to the image output device 2 and a tension applying roll unit 64, in addition to the feeding roll 61 rotationally driven by a driving unit (not shown). ing. The tension applying roll unit 64 is a moving roll that applies a required tension to the continuous paper 5 by being urged in a direction away from the pair of fixed rolls 64a and 64c fixedly arranged and the fixed rolls 64a and 64c. It consists of 64b.

  A pre-roll 65 as an example of a support member (support roll) for supporting the continuous paper 5 conveyed to the secondary transfer position T2 is disposed on the upstream side along the moving direction of the continuous paper 5 of the secondary transfer device 30 ing. Further, on the downstream side of the secondary transfer device 30 along the moving direction of the continuous paper 5, a post roll 66 as an example of a second support member (support roll) for supporting the continuous paper 5 that has passed the secondary transfer position. Is arranged.

  Further, on the downstream side of the image output device 2, a discharge device 4 for discharging and storing the continuous paper 5 on which the image is formed by the image output device 2 is mounted. The discharge device 4 includes a tension application roll unit 67 for applying tension to the continuous paper 5 discharged from the image output device 2 and transport rolls 68 and 69. The tension applying roll unit 67 includes a pair of fixed rolls 67a and 67c fixedly disposed, and a moving roll 67b biased in a direction away from the fixed rolls 67a and 67c to apply the required tension to the continuous paper 5. It consists of Further, the discharge device 4 includes a take-up roll 70 which is disposed rotatably in the clockwise direction in the drawing and takes up the continuous paper 5 in a roll shape. The take-up roll 70 is driven at a required rotational speed in the clockwise direction in the drawing by drive means (not shown).

<Basic Operation of Image Forming Apparatus>
Hereinafter, a basic image forming operation by the image output device 2 of the image forming apparatus 1 will be described.

  Here, using the five image forming devices 10 (Y, M, C, K, # 1) of the image output device 2, toner images of five colors (Y, M, C, K, # 1) are combined. An image forming operation when forming an image in which the toner image of the special color (# 1) is added to a normal full color image configured as described above will be described. In addition, using the five image forming devices 10 (Y, M, C, K, # 1) of the image output device 2, any one of five colors (Y, M, C, K, # 1) is used. The image forming operation when forming the above toner image is the same.

  When the control device 100 receives command information for a request for an image forming operation (print) by the operation of the user interface 104, the image output device 2 generates five image forming devices 10 (Y, M, C, K, # 1), The intermediate transfer device 20, the secondary transfer device 30, the fixing device 40 and the like start up.

  Then, in each image forming apparatus 10 (Y, M, C, K, # 1), as shown in FIG. 2, first, each photosensitive drum 11 rotates in the direction indicated by arrow A, and each charging device 12 The surface of each photosensitive drum 11 is charged to a desired polarity (minus polarity in the first embodiment) and potential. Subsequently, the exposure device 13 converts normal image information input to the image output device 2 into each color component (Y, M, C, K, # 1) on the surface of the photosensitive drum 11 after charging. The laser beam LB emitted based on the signal of the image obtained is irradiated to form an electrostatic latent image of each color component constituted by a required potential difference on the surface.

  Subsequently, each developing device 14 (Y, M, C, K, # 1) is charged to a required polarity (minus polarity) with respect to the electrostatic latent image of each color component formed on the photosensitive drum 11 Toners of corresponding colors (Y, M, C, K, # 1) are respectively supplied and electrostatically attached to perform development. The electrostatic latent image of each color component formed on each photosensitive drum 11 by this development is a toner image of five colors (Y, M, C, K, # 1) developed with the toner of the corresponding color. It is visualized as

  Subsequently, when the toner images of the respective colors formed on the photosensitive drums 11 of the image forming apparatuses 10 (Y, M, C, K, # 1) are conveyed to the primary transfer position, the primary transfer device 15 The toner images of the respective colors are primarily transferred in such a manner as to be sequentially superimposed on the intermediate transfer belt 21 rotating in the direction indicated by the arrow B of the intermediate transfer device 20.

  In addition, in each of the image forming apparatuses 10 (Y, M, C, K, # 1) where the primary transfer is completed, the drum cleaning device 16 scrapes the adhering matter such as toner remaining on the surface of the photosensitive drum 11. It is removed to clean the surface of the photosensitive drum 11. As a result, each image forming apparatus 10 (Y, M, C, K, # 1) is made ready for the next image forming operation.

  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. On the other hand, in the feeding device 3 and the discharging device 4, prior to the image forming operation, the continuous paper 5 is introduced from the feeding device 3 into the device main body 2 a of the image output device 2 through manual work of the user as needed. The leading end of the continuous paper 5 is taken out from the transport rolls 62 to 69 of the transport device 60 through the secondary transfer device 30 and the fixing device 40 to the outside of the device body 2 a of the image output device 2. It is wound around 70. At the time of normal image formation, the continuous paper 5 supplied from the supply device 3 is conveyed at a required conveyance speed inside the image output device 2 via the conveyance device 60, and then accommodated in the discharge device 4.

  At the secondary transfer position T2, the secondary transfer device 30 collectively and secondarily transfer the toner image on the intermediate transfer belt 21 onto the continuous paper 5. Further, in the intermediate transfer device 20 after the completion of the secondary transfer, the belt cleaning device 27 removes and cleans the extraneous matter such as toner remaining on the surface of the intermediate transfer belt 21 after the secondary transfer.

  Subsequently, the continuous paper 5 on which the toner image has been secondarily transferred is separated from the intermediate transfer belt 21 and the secondary transfer belt 31 and then conveyed to the fixing device 40. In the fixing device 40, necessary fixing processing (heating and pressing) is performed to fix the unfixed toner image on the continuous paper 5. Finally, the continuous paper 5 after the fixing is finished is discharged to the outside of the device main body 2 a of the image output device 2 and taken up by the winding roll 70 provided inside the discharge device 4.

  By the above-described operation, the continuous paper 5 on which the image obtained by adding the toner image of the special color to the normal full-color image formed by combining the four color toner images is output.

<Configuration of Secondary Transfer Device>
FIG. 3 is a block diagram showing a secondary transfer device of the image forming apparatus to which the medium support device according to Embodiment 1 of the present invention is applied.

  As shown in FIG. 3, the secondary transfer device 30 is a secondary transfer belt 31 as an example of an endless belt member that circularly moves (rotates) in the direction indicated by the arrow C while passing through the secondary transfer position T2. And the secondary transfer roll 32 and the driven roll 33 that support the secondary transfer belt 31 in a desired state from its inner periphery and support it so as to circulate freely, and adhere to the outer peripheral surface of the secondary transfer belt 31 It mainly comprises a belt cleaning device 34 that removes and cleans the toner, paper dust and the like.

  The secondary transfer roll 32 is configured as a drive roll and a belt support roll that constitute a drive portion of the secondary transfer belt 31, and the driven roll 33 is a belt support that rotatably holds the winding portion of the secondary transfer belt 31. The roll and the secondary transfer belt 31 are configured as a peeling roll for peeling the recording sheet 5. The outer diameter of the driven roller 33 is set smaller than that of the secondary transfer roller 32. Further, to the secondary transfer roll 32 or the belt supporting roll 25 of the intermediate transfer device 20, a direct current voltage having a polarity opposite to or the same as the charging polarity of the toner is supplied as a secondary transfer voltage. In this embodiment, a DC voltage having the same polarity (minus polarity) as the charging polarity of the toner is supplied to the belt support roll 25 of the intermediate transfer device 20 as a secondary transfer voltage through the energizing roll 28. Is configured.

  As the secondary transfer belt 31, for example, an endless belt made of a material in which a resistance regulator such as carbon black is dispersed in a synthetic resin such as polyimide resin or polyamide resin is used.

  The secondary transfer roll 32 functioning as a drive roll is configured by covering the outer periphery of a metal rotating shaft 321 with a conductive elastic layer 322 whose resistivity is adjusted.

  The belt cleaning device 34 includes a first fur brush 341 having conductivity, a first recovery roll 342, a second fur brush 343 having conductivity, and a second recovery roll 344.

  On the upstream side of the secondary transfer position T2, as shown in FIG. 3, a pre-roll 65 functioning as a resist roll is disposed in contact with the back surface (non-image surface) side of the continuous paper 5.

<Configuration of Characteristic Portion of Image Forming Apparatus>
As shown in FIGS. 4 and 5, the image forming apparatus 1 includes a medium support device 80 for supporting the continuous paper 5 as a continuous medium from the upstream side to the downstream side of the secondary transfer position T2. The medium support device 80 functions as contact / separation means for movably supporting the secondary transfer device 30 and the pre-roll 65, and further, the post-roll 66 in a direction in which the intermediate transfer belt 21 of the intermediate transfer device 20 is moved. Also has. The intermediate transfer device 20 is disposed in a fixed state on the device main body 2 a side of the image output device 2. The medium support device 80 also includes an intermediate transfer device 20 including an intermediate transfer belt 21 with which the secondary transfer device 30 contacts and separates via the continuous paper 5 as a continuous medium.

  In the image forming apparatus 1, as shown in FIGS. 1 and 3, during image formation, the intermediate transfer belt 21 as an example of the first rotating member circulates at a constant speed equal to the process speed of the image forming apparatus 1. It is rotationally driven by a belt support roll 22 as a drive roll so as to rotate. In the image forming apparatus 1, the intermediate transfer belt 21 is formed on the intermediate transfer belt 21 via the continuous paper 5 as an example of a medium in which the secondary transfer belt 31 as an example of the second rotating body and the secondary transfer roll 32 are continuous at the time of image formation. The secondary transfer belt 31 and the secondary transfer roll 32 move together with the continuous paper 5 so as to be separated from the intermediate transfer belt 21 while moving so as to be in contact by the medium support device 80 functioning as contact / separation means. Do.

  The medium supporting device 80 is disposed at each end along the axial direction of the pre-roll 65 and the post-roll 66 as shown in FIGS. 4 and 5, and the pre-roll 65 and the post-roll 66 against the intermediate transfer belt 21. A first support arm 81 is provided as an example of a first arm member that supports in a direction to approach and separate. As shown in FIG. 6, the first support arm 81 is rotatably mounted centering on a pivot 82 acting as a fulcrum arranged in a fixed state to the secondary transfer device main body 95 (see FIG. 4). ing.

  The pre-rolls 65 are rotatably supported by first bearing members 83 respectively disposed at both ends along the axial direction of the pre-rolls 65, as shown in FIGS. 4 and 5. The first bearing member 83 is attached to an attachment portion 84 provided on the upper end portion of the first support arm 81 so as to be bent outward via the first support plate 85 disposed along the axial direction of the pre-roll 65. It is fixed by means such as screwing.

  Similarly, the post rollers 66 are rotatably supported by second bearing members 86 respectively disposed at both ends along the axial direction of the post rollers 66. The second bearing member 86 is provided at an attachment portion 87 provided on the upper end portion of the first support arm 81 so as to be bent outward, via a second support plate 88 disposed along the axial direction of the pre-registration roll 66. It is fixed by means such as screwing.

  Further, the secondary transfer roll 32 of the secondary transfer device 30 is rotatably supported by third bearing members 89 respectively disposed at both ends along the axial direction of the secondary transfer roll 32. The third bearing member 89 is fixed to the upper end portion of the second support arm 90 as an example of the second arm member by means such as screwing. The third bearing member 89 is attached to a mounting plate 90 a having a relatively large thickness. Mounting plates 90a respectively disposed at both ends along the axial direction of the secondary transfer roll 32 are connected and fixed to each other by a second support plate 91, as shown in FIGS. 4 and 5. The axial distance between the secondary transfer roll 32 and the belt support roll 25 is maintained at a required value by engaging with a positioning pin (not shown) provided on the side of the intermediate transfer belt 21 at the upper end of the mounting plate 90a. The positioning member 92 provided with the recessed part which carries out is provided. The driven roller 33 is rotatably attached to the mounting plate 90a via a bearing member (not shown). 4 and 5, the secondary transfer belt 31 is omitted for the sake of convenience.

  Between the first support arm 81 and the second support arm 90, as shown in FIGS. 4 and 8, the first support arm 81 and the second support arm 90 are brought into contact with or separated from the intermediate transfer belt 21. A drive arm 93 as an example of a third arm member provided with drive means for driving in the direction is disposed. The drive arms 93 are respectively disposed at both ends along the axial direction of the secondary transfer roll 32, and are fixed to the secondary transfer device main body 95 in a state of being axially supported by the support shaft 82. The lower ends of the left and right drive arms 93 are connected to each other by a connecting plate 94, as shown in FIGS. Between the connection plate 94 and the secondary transfer device main body 95, a coil spring 96 for grounding the drive arm 93 is interposed.

  Further, as shown in FIG. 8, first and second rotation shafts 97 and 98 are rotatably provided on the left and right drive arms 93. The first and second rotation shafts 97 and 98 are required by a drive source such as a drive motor (not shown) provided on the connection plate 94 of the drive arm 93 via the drive gears 201 and 202 and the driven gears 203 to 206, respectively. It is rotationally driven by the required amount of rotation in the direction of. The first eccentric cam 207 is attached to the first rotation shaft 97 in a fixed state. The first eccentric cam 207 is arranged to be in contact with an abutting portion 81 a (see FIGS. 4 and 5) provided on the tip of the first support arm 81 so as to be bent outward. Further, the second eccentric cam 208 is attached to the second rotation shaft 98 in a fixed state. The second eccentric cam 208 is arranged to be in contact with the contact portion 209 (see FIG. 7) of the second support arm 90. The contact portion 209 is provided so as to be located between the drive arm 90 and the first support arm 81. The contact portion 209 is for contacting the second eccentric cam 208 to rotate the second support arm 90. The contact portion 209 does not necessarily have to be provided integrally with the second support arm 90, and via a link mechanism or the like not shown. It may be connected with the second support arm 90. In addition, the contact portion 209 may be bent at both ends along the width direction in order to increase the rigidity.

  As shown in FIGS. 4 and 5, the drive arm 93 includes a biasing frame portion 210 provided to surround the inside and the outside of the second support arm 90 in the form of a substantially rectangular frame. A second coil spring 211 composed of a tension spring as an example of a second elastic member is interposed between the distal end portion 90 b of the second support arm 90 and the biasing frame portion 210 of the drive arm 93. The second support arm 90 is biased in a direction in which it is in pressure contact with the intermediate transfer belt 21 by the elastic force of the second coil spring 211.

  As shown in FIG. 9, when the second support arm 90 moves so as to be pushed down by the second eccentric cam 208, the secondary transfer roll 32 attached to the second support arm 90 becomes the intermediate transfer belt 21 and the belt. It moves (displaces) away from the support roll 25.

  Detection means such as an encoder (not shown) for detecting the rotation direction and the amount of rotation of the first and second rotation shafts 97 and 98 are provided on the first and second rotation shafts 97 and 98, respectively. Is controlled by the control device 100.

  Also, the first support arm 81 on which the pre-roll 65 and the post-roll 66 are rotatably supported is bridged between the lower end 81 a and the left and right drive arms 93 as shown in FIGS. 4 and 5. It connects via the 1st coil spring 221 which consists of a tension spring as an example of the 1st elastic member arranged between holding rods 220. Therefore, as shown in FIG. 10, when the first support arm 81 moves so as to be pushed down by the first eccentric cam 207, the pre-roll 65 and the post-roll 66 attached to the first support arm 81 also move downward. Then, the pre-roll 65 and the post-roll 66 move (displace) in the direction away from the intermediate transfer belt 21.

Further, as shown in FIG. 6, when the first eccentric cam 207 rotates so as to separate from the contact portion 81 a as shown in FIG. 6, the elastic force of the first coil spring 221 causes clockwise rotation in the drawing. It rotates along and moves in the direction approaching the intermediate transfer belt 21. At this time, when the pre-roll 65 and the post-roll 66 attached to the first support arm 81 stretch the continuous paper 5, the tension of the continuous paper 5 causes the pre-roll 65 and the post roll 66 to be pushed down. The first support arm 81 is stopped in a state where the elastic force of the coil spring 221 and the tension of the continuous paper 5 are balanced. At that time, in the first support arm 81, the first eccentric cam 207 is separated from the contact portion 81a, and the position is not restricted by the first eccentric cam 207, and a constant load is applied by the elastic force of the first coil spring 221. It is in a supported state. Similarly, the pre-roll 65 and the post-roll 66 attached to the first support arm 81 are also supported by a constant load by the elastic force of the first coil spring 221.
As shown in FIGS. 4 and 5, when the first support arm 81 is rotated in the clockwise direction in the drawing by the elastic force of the first coil spring 221, the pre-roll 65 or the like is loosened or the continuous paper 5 is loosened. In order to prevent the intermediate transfer belt 21 from being damaged by unintentional contact with the intermediate transfer belt 21 due to cutting or the like, the first support arm 81 is provided with a restricting portion 81 b for restricting the position. The restricting portion 81 b of the first support arm 81 abuts on a restricting rod 81 c fixedly provided on the secondary transfer device main body 95 to restrict the upward movement. The first support arm 81 normally operates at a position where the restricting portion 81 b does not abut on the restricting rod 81 c.

<Operation of Characteristic Portion of Image Forming Apparatus>
In the image forming apparatus 1 according to the first embodiment, as described below, contact and separation via the continuous paper 5 as a medium continuous with the intermediate transfer belt 21 as the first rotating body rotating at a constant speed. When the secondary transfer belt 31 and the secondary transfer roll 32 as the second rotating body to contact are brought into contact with the intermediate transfer belt 21 via the continuous paper 5, the secondary transfer with which the continuous paper 5 and the continuous paper 5 are in contact The occurrence of the speed difference between the belt 31 and the secondary transfer roll 32 is suppressed.

  That is, in the image forming apparatus 1 according to Embodiment 1 of the present invention, as shown in FIGS. 10 and 11, the secondary transfer device 30 is the intermediate transfer belt 21 in the standby state before the image forming operation starts. The pre-roll 65 is also moved to the retracted position (first position) separated from the normal operating position (second position).

  More specifically, in the image forming apparatus 1, the service engineer performs a work or the like in the adjustment mode in which the image forming operation is adjusted at the time of replacement work in which the image forming operation is stopped or interrupted and the replacement work is performed. At the time of non-image formation such as in the work mode, the imaging device 10, the intermediate transfer device 20, the secondary transfer device 30, the fixing device 40, etc. are stopped, and the conveyance of the continuous paper 5 is also stopped.

  During the non-image formation, as shown in FIGS. 10 and 11, the continuous paper 5 is separated from the intermediate transfer belt 21, and the secondary transfer device 30 is also separated from the continuous paper 5. At the time of non-image formation, the intermediate transfer belt 21 is stopped, and the continuous paper 5 is also not conveyed and is stopped. At this time, an operation of removing the continuous paper 5 on which an image is formed from the image output device 2 or an operation of loading a new continuous paper 5 into the image output device 2, the supply device 3, and the discharge device 4 is performed. .

  At that time, assuming that the moving speed of the intermediate transfer belt 21 during non-image formation is T1, the conveying speed of the continuous paper 5 is P1, and the moving speed of the secondary transfer belt 31 is B1, the moving speed T1 of the intermediate transfer belt 21 is arbitrary. It may be stopped (T1 = 0) as described above. Further, the conveyance speed P1 of the continuous paper 5 is also arbitrary, and may be stopped (P1 = 0). Furthermore, the moving speed B1 of the secondary transfer belt 31 is also arbitrary, and may be stopped (B1 = 0). In this embodiment, the intermediate transfer belt 21, the continuous paper 5, and the secondary transfer belt 31 are all stopped at the time of non-image formation, and the moving speed is set to zero (T1 = P1 = B1 = 0). .

  At this time, as shown in FIG. 10, the medium support device 80 is mounted on the first support arm 81 by driving the first eccentric cam 207 to rotate the first support arm 81 in the counterclockwise direction. The pre-roll 65 and the post-roll 66 are moved to the standby position (first position) where the continuous paper 5 is separated from the intermediate transfer belt 21.

  At the same time, as shown in FIG. 9, the medium support device 80 is mounted on the second support arm 90 by driving the second eccentric cam 208 to rotate the second support arm 90 in the same counterclockwise direction. The second transfer device 30 is moved to a third position separated from the intermediate transfer belt 21.

  Next, when the image forming operation is started or restarted in the image forming apparatus 1, as shown in FIG. 12, the first eccentric cam 207 is driven to rotate the first support arm 81 clockwise. As a result, the continuous paper 5 is moved to the second position where it contacts the intermediate transfer belt 21. At this time, the intermediate transfer belt 21 is driven to move at a required transport speed T2 before the continuous paper 5 contacts. Similarly, before the continuous paper 5 comes into contact with the intermediate transfer belt 21, the supply device 3 and the discharge device 4 are driven to be transported at a required transport speed P2. Here, the moving speed T2 of the intermediate transfer belt 21 and the conveying speed P2 of the continuous paper 5 are set to an equal value (T2 = P2). Assuming that the moving speed of the secondary transfer belt 31 is B2, the moving speed B2 of the secondary transfer belt 31 is arbitrary and may be stopped (B2 = 0).

  In this embodiment, as shown in FIG. 12, while the continuous paper 5 supported by the pre-roll 65 moves to a position where it contacts the intermediate transfer belt 21, the pre-roll 65 and the post-roll 66 are first The position of the support arm 81 is regulated by the first eccentric cam 207 and is in a constant displacement state. Further, as shown in FIG. 9, the secondary transfer device 30 is also supported in a constant displacement state by restricting the position of the second support arm 90 by the second eccentric cam 208. However, at this time, the pre-roll 65 is not limited to being supported in a constant displacement state, and may be configured to be supported in a constant load state. Similarly, at this time, the post roll 66 is not limited to being supported in a constant displacement state, and may be configured to be supported in a constant load state.

  Thereafter, as shown in FIG. 13, the secondary transfer device 30 is driven so that the secondary transfer belt 31 is driven and the second support arm 90 is rotated by the second eccentric cam 208, and the secondary transfer is carried out. The belt 31 is moved to the fourth position where it contacts the intermediate transfer belt 21 via the continuous paper 5. At this time, the moving speed B3 of the secondary transfer belt 31 of the secondary transfer device 30 is driven at a speed (T3 = P3 = B3) equal to that of the continuous paper 5 and the intermediate transfer belt 21.

  Furthermore, as shown in FIGS. 7 and 14, the secondary transfer device 30 is driven to rotate the second support arm 90 clockwise by the second eccentric cam 208, and the secondary transfer belt 31 and the secondary The transfer roll 32 is moved to the fifth position in pressure contact with the intermediate transfer belt 21 via the continuous paper 5, and the preparation operation for starting the image forming operation is completed.

  At this time, if the position of the pre-roll 65 is fixed, after the secondary transfer belt 31 and the secondary transfer roll 32 contact the continuous paper 5, the secondary transfer belt 31 and the secondary transfer roll 32 are continuous. When the intermediate transfer belt 21 is in pressure contact with the paper 5, the transport path of the continuous paper 5 becomes longer by the amount by which the secondary transfer belt 31 and the secondary transfer roll 32 press against the intermediate transfer belt 21. The tension of 5 and the speed of the continuous paper 5 increase momentarily.

  At that time, as shown in FIG. 1, the continuous paper 5 is conveyed at a constant conveying speed by the supply roll 61 of the supply device 3 having a relatively large outer diameter and mass and relatively large inertia. Although the tension applying roll unit 64 is disposed in the feeding device 3, tension fluctuation of the continuous paper 5 occurs instantaneously. Therefore, the feeder 3 can not cope with the instantaneous tension fluctuation of the continuous paper 5, and between the continuous paper 5 and the intermediate transfer belt 21 and between the continuous paper 5 and the secondary transfer belt 31. As the speed of the continuous paper 5 increases, rubbing occurs. As a result, abrasion may occur between the continuous paper 5 and the intermediate transfer belt 21 or the secondary transfer belt 31, or the conveyance load of the secondary transfer belt 31 having a circumferential length shorter than that of the intermediate transfer belt 21 may be in the axial direction. In some cases, the secondary transfer belt 31 may be displaced in the axial direction, that is, so-called belt walk may occur. In order to suppress the belt walk of the secondary transfer belt 31, it is necessary to newly provide a belt walk suppression device, which leads to an increase in the size of the device.

  On the other hand, in the case of the first embodiment, as shown in FIG. 6, the secondary transfer belt 31 and the secondary transfer roll 32 of the secondary transfer device 30 are supported by the belt support roll via the continuous paper 5. When pressing the intermediate transfer belt 21 supported by 25 in pressure contact, the pre-roll 65 in contact with the continuous paper 5 has a constant load even if the tension is going to increase as the speed of the continuous paper 5 fluctuates. It is supported. Therefore, the pre-roll 65 moves so as to offset the increase in tension of the continuous paper 5 to act to maintain the tension of the continuous paper 5 constant, as shown by the broken line in FIG. The occurrence of speed fluctuation is suppressed or prevented.

  Therefore, it is possible to suppress or prevent the occurrence of wear between the continuous paper 5 and the intermediate transfer belt 21 or the secondary transfer belt 31 or the occurrence of belt walk on the secondary transfer belt 31. Moreover, the enlargement of the apparatus accompanying provision of a belt walk suppression apparatus is avoided.

Second Embodiment
FIG. 15 shows an image forming apparatus to which the medium supporting device according to the second embodiment is applied. In this second embodiment, unlike the first embodiment described above, the state in which only the intermediate transfer belt 21 and the continuous paper 5 are in contact is omitted.

  That is, in the first embodiment, as shown in FIG. 9, after temporarily shifting to a state in which only the intermediate transfer belt 21 and the continuous paper 5 are in contact, as shown in FIG. The state is shifted to a state in which the paper 5 and the secondary transfer roll 32 of the secondary transfer device 30 are in contact with each other.

  On the other hand, in the second embodiment, as shown in FIG. 15, the intermediate transfer belt 21 and the continuous paper 5 are not immediately shifted to the state where only the intermediate transfer belt 21 and the continuous paper 5 are in contact. The secondary transfer roll 32 of the secondary transfer device 30 is configured to shift to a contact state.

  At that time, assuming that the moving speed of the intermediate transfer belt 21 is T2, the conveying speed of the continuous paper 5 is P2, and the moving speed of the secondary transfer belt 31 is B2, the moving speed T2 of the intermediate transfer belt 21 and the conveying of the continuous paper 5 The speed P2 and the moving speed B2 of the secondary transfer belt 31 are set to, for example, equal speeds.

  Thereafter, in the second embodiment, as shown in FIG. 14, the secondary transfer roll 32 of the secondary transfer device 30 is driven by the belt support roll 25 through the continuous paper 5 as in the first embodiment described above. The state shifts to a state of being in pressure contact with the supported intermediate transfer belt 21.

  In the second embodiment, since the state in which the intermediate transfer belt 21 and the continuous paper 5 are in contact with each other can be omitted, it is possible to shorten the time for transition to the image formable state, such as when the continuous paper 5 is replaced. .

Third Embodiment
FIG. 16 shows an image forming apparatus to which the medium supporting device according to the third embodiment is applied.

  In the third embodiment, as shown in FIG. 16, the pre-roll 65 as an example of the support member is in contact with the front surface (upper surface) side of the continuous paper 5, not the back surface (lower surface) side of the continuous paper 5. It is arranged to support the continuous paper 5. Therefore, the pre-roll 65 is supported so that an elastic force in the direction of separating from the intermediate transfer belt 21 acts. Further, on the upstream side along the moving direction of the continuous paper 5 of the pre-roll 65, a fixed roll 64d that regulates the transport position of the continuous paper 5 is disposed.

  Further, in the third embodiment, as shown in FIG. 17, in the first support arm 81 on which the pre-roll 65 is rotatably supported, the first coil spring 221 has an upper end 81 e of the first support arm 81. , And the other end of the first coil spring 221 is locked to the holding rod 220 disposed below. The first support arm 81 is biased in the counterclockwise direction by the elastic force of the first coil spring 221. The first eccentric cam 207 is arranged to rotate the first support arm 81 in the clockwise direction against the elastic force of the first coil spring 221.

  In the medium support device 80 according to the third embodiment, as shown in FIG. 18, when the tension of the continuous paper 5 is increased when the continuous paper 5 moves to the state of pressing against the intermediate transfer belt 21, the continuous paper 5 is By moving the pre-registration roll 65 upward in the direction approaching the intermediate transfer belt 21 with the increase of the tension of the paper, the constant tension of the continuous paper 5 is supported so as to be substantially constant. .

Fourth Embodiment
FIG. 19 shows an image forming apparatus to which the medium supporting device according to the fourth embodiment is applied. In the fourth embodiment, the post roll 66 as a second support member disposed downstream of the secondary transfer position along the moving direction of the continuous sheet moves in a direction in which it contacts and separates from the intermediate transfer belt 21. It is configured to be possible.

  That is, in the fourth embodiment, as shown in FIG. 6, the post roll 66 is attached to the first support arm 81, and the first support arm 81 is attached to the intermediate transfer belt 21 by the first eccentric cam 207. And movable in the direction of contact and separation.

  In the fourth embodiment, as shown in FIG. 19, when the type of continuous paper 5 is changed, the position of post roll 66 is moved in a direction to contact and separate from intermediate transfer belt 21. The peeling angle of the continuous paper 5 to the intermediate transfer belt 21 is changed.

  To explain further, as the continuous medium, in addition to the continuous paper 5 made of plain paper, it is composed of various materials such as a continuous synthetic resin thin film or sheet, a film on which a metal layer is laminated, or a continuous label paper. Are used. When the continuous medium is a thin film or sheet made of a synthetic resin, or a film in which a metal layer is laminated, the medium passed the secondary transfer position T2 because its rigidity is smaller than that of plain paper. Is electrostatically attracted to the intermediate transfer belt 21 side, and the medium to be originally separated from the intermediate transfer belt 21 and to be sent to the fixing device 40 tends to stick to the intermediate transfer belt 21 by electrostatic attraction, and the medium There is a possibility that so-called POB jam (paper on belt jam), which is conveyed together with the intermediate transfer belt 21 as it is, may occur. In addition, when the resistance value of the medium is high, as in the case of producing a print in a low-temperature low-humidity environment, a large electrostatic attraction force acts on the medium, which is also likely to occur as a POB jam.

  Further, even if the POB jam does not occur, when the medium having passed the secondary transfer position T2 approaches the intermediate transfer belt 21 too much, the toner image secondarily transferred to the medium is retransferred to the intermediate transfer belt 21. And the phenomenon of so-called retransfer occurs, which may deteriorate the image quality of the image formed on the medium.

  Therefore, in the fourth embodiment, in the case of a medium or condition in which POB jam or retransfer is likely to occur, the post roll 66 is moved away from the intermediate transfer belt 21 as shown in FIG. And prevent or suppress the occurrence of POB jam.

  In the above embodiment, a full-color image forming apparatus for forming toner images of four colors of yellow (Y), magenta (M), cyan (C) and black (K) as an image forming apparatus has been described. Of course, the present invention can be similarly applied to an image forming apparatus for forming an image of In a monochrome image forming apparatus, a photosensitive drum is configured as an image carrier, and a unit including a transfer roll or the like contacting with the photosensitive drum via a recording medium continuous as a second rotating body.

  Further, in the above embodiment, although the secondary transfer device provided with the secondary transfer belt as the second rotating body has been described, the present invention is not limited to this, and the second rotating body may be a secondary Of course, it may be a transfer roll.

  Furthermore, in the above-described embodiment, the image forming apparatus has been described as an example, but the present invention is not limited to the image forming apparatus, and the first and second rotating bodies are in contact through a continuous medium. It can be widely applied to the apparatus provided.

1 Image forming apparatus 1a Image forming apparatus main body 11 Photosensitive drum 21 Intermediate transfer belt 30 Secondary transfer device 31 Secondary transfer belt 32 Secondary transfer roll 80 Medium supporting device

Claims (20)

A first rotating body moving at a constant speed,
A second rotor that contacts and separates from the first rotor via a medium continuous with the first rotor;
A support member disposed on the upstream side along the moving direction of the medium of the second rotating body, and supporting the medium with a constant load;
Medium support device comprising:   The medium support device according to claim 1, wherein the support member is mounted on a first arm member rotatable around a fulcrum, and the first arm member is given an elastic force by a first elastic member. .   The support member is moved by a first eccentric cam that rotates the first arm member to a first position separated from the first rotary body and a second position closer to the first rotary body than the first position. A media support apparatus according to claim 2, which is possible.   The medium support device according to claim 3, wherein the support member is switched from constant displacement to constant load when moving from the first position to the second position.   The second rotating member is mounted on a second arm member rotatable about a fulcrum, and the second arm member is elastic in a direction in which it is pressed against the first rotating member by a second elastic member. A media support apparatus according to claim 1 which is provided.   The second rotating body has a third position spaced apart from the first rotating body, a fourth position contacting with the first rotating body via a medium continuous, and a medium continuous to the first rotating body 6. The medium support device according to claim 5, wherein the medium support device is movable by a second eccentric cam that rotates the second arm member to a fifth position where pressure contact is performed.   The medium support apparatus according to any one of claims 1 to 6, further comprising: a second support member disposed downstream of the second rotating body along the moving direction of the medium and supporting the medium. An image carrier that holds a toner image and moves at a constant speed;
A transfer unit that contacts and separates from the image carrier via a recording medium continuous with the image carrier and transfers the toner image held by the image carrier to the recording medium;
A support member disposed upstream of the transfer means along the direction of movement of the recording medium and supporting the recording medium with a constant load;
An image forming apparatus comprising:   9. The image forming apparatus according to claim 8, wherein the support member is mounted on a first arm member rotatable around a fulcrum, and the first arm member is given an elastic force by a first elastic member. .   The support member is movable by a first eccentric cam that rotates the first arm member to a first position separated from the image carrier and a second position closer to the image carrier than the first position. The image forming apparatus according to claim 9.   The second rotating member is mounted on a second arm member rotatable around a fulcrum, and the second arm member is given an elastic force in a direction in which it is pressed against the image holding member by a second elastic member. The image forming apparatus according to claim 8.   The transfer means is in pressure contact with a third position separated from the image carrier, a fourth position contacted with the image carrier via a recording medium continuous with the image carrier, and a recording medium continuous with the image carrier The image forming apparatus according to claim 11, wherein the image forming apparatus is movable to a fifth position by a second eccentric cam that rotates the second arm member.   The image forming apparatus according to any one of claims 8 to 12, further comprising: a second support member disposed downstream of the transfer unit along the moving direction of the recording medium and supporting the recording medium. An intermediate transfer member to which the toner image is transferred from a plurality of image forming means for forming toner images of mutually different colors;
A secondary transfer unit that transfers the toner image transferred to the intermediate transfer body to a continuous recording medium;
Contact and separation means for causing the secondary transfer means to contact and separate from the image carrier via the recording medium;
A support member disposed upstream of the secondary transfer means along the direction of movement of the recording medium and supporting the recording medium with a constant load;
An image forming apparatus comprising:   The image forming apparatus according to claim 14, wherein the support member is mounted on a first arm member rotatable around a fulcrum, and the first arm member is given an elastic force by a first elastic member. .   The support member is movable by a first eccentric cam that rotates the first arm member to a first position separated from the intermediate transfer body and a second position closer to the intermediate transfer body than the first position. The image forming apparatus according to claim 15.   The image forming apparatus according to claim 16, wherein the support member is switched from constant displacement to constant load when moving from the first position to the second position.   The secondary transfer means is mounted on a second arm member rotatable around a fulcrum, and the second arm member is given an elastic force in a direction to press against the intermediate transfer member by a second elastic member. The image forming apparatus according to claim 14.   The secondary transfer unit is configured to receive a third position spaced from the intermediate transfer member, a fourth position in contact with the intermediate transfer member via a recording medium connected to the intermediate transfer member, and a recording medium connected to the intermediate transfer member. The image forming apparatus according to claim 18, wherein the image forming apparatus is movable by a second eccentric cam that rotates the second arm member to a fifth position to be in pressure contact.   The image forming apparatus according to any one of claims 14 to 19, further comprising: a second support member disposed downstream of the secondary transfer unit along the moving direction of the medium and supporting the recording medium.

Images