JP7110716B2 - Fixing device and image forming device - Google Patents

Description

The present invention relates to fixing devices and image forming apparatuses.

In Patent Document 1, in a fixing device that heats a transfer material on which a toner image has been transferred and fixes the toner image, an electrode is arranged at a transfer material conveying outlet for discharging the transfer material from the fixing device, and the transfer material is transferred to the electrode. A configuration is disclosed that pulls the material and separates the transfer material from the fuser roll.

JP-A-2006-58493

Here, when a continuous recording medium such as continuous paper conveyed in a predetermined conveying direction is heated and softened in the fixing section, the continuous recording medium expands or contracts. The recording medium may expand and contract.

An object of the present invention is to suppress expansion and contraction of a continuous recording medium heated in a fixing section, compared to a configuration in which the continuous recording medium contacts a member arranged immediately downstream of the fixing section in the conveying direction without being adsorbed. do.

In the first mode, a fixing unit heats and fixes an image on a continuous recording medium conveyed in a predetermined conveying direction, and the continuous recording medium is fixed by electrostatic force directly downstream of the fixing unit in the conveying direction. and an adsorption part for adsorbing to.

In the second aspect, the suction section causes the non-image surface of the continuous recording medium to adhere to itself.

In the third aspect, a voltage is applied to the attraction portion.

In the fourth aspect, the attraction section is applied with a voltage having a voltage value smaller in absolute value than the voltage value of the transfer voltage applied when the image is transferred to the continuous recording medium.

In the fifth aspect, the adsorption section is grounded via a resistor.

In the sixth aspect, the suction section is rotationally driven with a speed difference with respect to the conveyed continuous recording medium.

In a seventh aspect, the attraction section is charged by friction with the continuous recording medium.

In the eighth aspect, the adsorption section has a cooling mechanism for cooling the continuous recording medium.

In a ninth aspect, a first suction portion as the suction portion and a surface of the continuous recording medium opposite to the suction surface of the first suction portion immediately downstream of the first suction portion in the conveying direction and a second attracting portion that attracts to itself by electrostatic force.

In the tenth aspect, the first adsorption portion and the second adsorption portion are charged to opposite polarities.

In the eleventh aspect, the second adsorption section has a cooling mechanism for cooling the continuous recording medium.

In a twelfth aspect, a conveying unit conveys the continuous recording medium while tension is applied to the continuous recording medium along the conveying direction; and a fixing device according to any one of the first to eleventh modes for fixing the image.

In a thirteenth aspect, a transfer section is provided to transfer the image onto the continuous recording medium by applying a transfer voltage, and the fixing device determines the polarity of the continuous recording medium charged by the transfer of the image in the transfer section. It has the attraction part that is charged to the opposite polarity.

According to the configuration of the first mode , compared with the configuration in which the continuous recording medium contacts the member arranged immediately downstream of the fixing section in the conveying direction without being adsorbed, the expansion and contraction of the continuous recording medium heated in the fixing section is suppressed. can.

According to the configuration of the second aspect , the continuous recording medium can be cooled earlier than the image compared to the configuration in which the suction unit attracts the image surface of the continuous recording medium to itself.

According to the configuration of the third aspect , the continuous recording medium can be attracted to the attracting portion by electrostatic force without electrifying the attracting portion by friction with the continuous recording medium.

According to the configuration of the fourth aspect , it is possible to suppress poor adsorption of the continuous recording medium to the adsorption portion, compared to a configuration in which a voltage having an absolute value equal to or greater than the voltage value of the transfer voltage is applied.

According to the configuration of the fifth aspect , the continuous recording medium can be attracted to the attracting portion by electrostatic force without applying a voltage to the attracting portion.

According to the configuration of the sixth aspect , the continuous recording medium can be attracted to the attracting portion by electrostatic force without applying a voltage to the attracting portion.

According to the configuration of the seventh aspect , the continuous recording medium can be attracted to the attracting portion by electrostatic force without applying a voltage to the attracting portion.

According to the configuration of the eighth aspect , the continuous recording medium can be cooled in a short time compared to the configuration in which the adsorption section naturally cools the continuous recording medium.

According to the configuration of the ninth aspect , expansion and contraction of the continuous recording medium heated in the fixing section can be suppressed compared to the configuration in which the continuous recording medium is adsorbed only by the first adsorption section.

According to the configuration of the tenth aspect , a continuous recording medium having different polarities on the front surface and the back surface can be attracted to the first suction portion and the second suction portion.

According to the configuration of the eleventh aspect , the continuous recording medium can be cooled in a short time compared to the configuration in which the second adsorption section naturally cools the continuous recording medium.

According to the configuration of the twelfth mode , compared to the configuration in which the continuous recording medium contacts the member arranged immediately downstream of the fixing section in the conveying direction without being adsorbed, the continuous recording medium heated in the fixing section moves in the conveying direction. elongation can be suppressed.

According to the configuration of the thirteenth aspect , the adsorption section can adsorb the continuous recording medium charged by the transfer of the image in the transfer section by electrostatic force.

1 is a schematic configuration diagram showing an image forming apparatus according to an embodiment; FIG. 2 is a schematic configuration diagram showing a toner image forming section used in the image forming apparatus according to the exemplary embodiment; FIG. 4 is a schematic diagram showing how a continuous recording medium is charged in a transfer section according to the present embodiment; FIG. 1 is a schematic configuration diagram showing a fixing device according to an exemplary embodiment; FIG. 4 is a schematic perspective view showing an example of a cooling mechanism for a first adsorption section (second adsorption section) of the fixing device; FIG. 6 is a schematic enlarged cross-sectional view showing a toner image before fixing on paper when the continuous recording medium is paper in a fixing device of a comparative example; FIG. FIG. 7 is a schematic enlarged cross-sectional view showing a process of fixing a toner image on paper with a fixing roll when the continuous recording medium is paper in the fixing device of the comparative example. 6 is a schematic enlarged cross-sectional view showing a state in which a toner image is fixed on paper when the continuous recording medium is paper, in a fixing device of a comparative example; FIG. 6 is a schematic enlarged cross-sectional view showing a state in which a toner image on a resin film is fixed by a fixing roll in a fixing device of a comparative example when the continuous recording medium is a resin film; FIG. 6 is a schematic enlarged cross-sectional view showing a state in which a toner image is fixed on a resin film when the continuous recording medium is a resin film in a fixing device of a comparative example; FIG. FIG. 11 is a schematic configuration diagram showing an image forming apparatus according to a modified example;

An example of an embodiment according to the present invention will be described below with reference to the drawings. Note that the arrow H shown in each figure is vertical and indicates the vertical direction of the device, and the arrow W is horizontal and indicates the width direction of the device.

<Image forming apparatus 10>
A configuration of the image forming apparatus 10 will be described. FIG. 1 shows the configuration of the image forming apparatus 10 viewed from the front side.

An image forming apparatus 10 shown in FIG. 1 is an apparatus for forming an image on a continuous recording medium. Specifically, as shown in FIG. 1, the image forming apparatus 10 conveys the continuous recording medium P previously arranged on the conveying path in a predetermined conveying direction (direction of arrow B in FIG. 1), and It is an apparatus for forming an image on a continuous recording medium P. In other words, the image forming apparatus 10 can also be said to be a conveying device that conveys the continuous recording medium P. Hereinafter, the "conveyance direction in which the continuous recording medium P is conveyed" may be simply referred to as the "conveyance direction".

More specifically, the image forming apparatus 10 has a conveying section 50 , an image forming section 12 , a fixing device 60 and a control section 100 . The continuous recording medium P on which images are formed by the image forming apparatus 10 and each section (the control section 100, the conveying section 50, the image forming section 12, and the fixing device 60) of the image forming apparatus 10 will be described below.

(Continuous recording medium P)
The continuous recording medium P is an example of a continuous recording medium transported in a predetermined transport direction. This continuous recording medium P is a recording medium that is continuous in the transport direction. Specifically, the continuous recording medium P is a recording medium on which images can be formed on a plurality of pages that are continuous in the transport direction.

As the continuous recording medium P, for example, a resin film made of a resin material such as PET (polyethylene terephthalate) or PP (polypropylene) is used.

Furthermore, the continuous recording medium P is a recording medium that is transported from a state that has been arranged in advance on the transport path. Further, the continuous recording medium P is also a recording medium that is conveyed while being tensioned along the conveying direction. The continuous recording medium P is also a recording medium that softens and expands and contracts when heated. The continuous recording medium P has, for example, an image surface 2A (see FIG. 4) on which an image is formed on the front surface, and a non-image surface 2B (see FIG. 4) on which no image is formed on the back surface.

The continuous recording medium P is not limited to a resin film, and may be plain paper (manufactured by gluing vegetable fibers or other fibers) or metal foil (for example, aluminum foil). The material of medium P does not matter. Also, the continuous recording medium P may be a recording medium in which a resin film and a metal foil are laminated. As a recording medium in which a resin film and a metal foil are laminated, for example, there is a recording medium having a metal foil on one of the image surface 2A and the non-image surface 2B and a resin film on the other surface.

(control unit 100)
The control section 100 is a section having a function of controlling the operation of each section of the image forming apparatus 10 including the conveying section 50 , the image forming section 12 and the fixing device 60 . Each section of the image forming apparatus 10 including the conveying section 50 , the image forming section 12 and the fixing device 60 is connected to the control section 100 .

(Conveyor 50)
The transport unit 50 is an example of a transport unit that transports the continuous recording medium while applying tension to the continuous recording medium along the transport direction. Specifically, as shown in FIG. 1, the conveying section 50 includes an unwinding roll 51, a winding roll 53, a driving section 55, and winding rolls 52, 54, and 56. .

The unwinding roll 51 is a roll for unwinding the continuous recording medium P. As shown in FIG. A trailing end portion (an upstream portion in the conveying direction) of the continuous recording medium P is wound in advance around the feed roll 51 . The unwinding roll 51 rotates in one direction (direction of arrow C in FIG. 1) to unwind the wound continuous recording medium P toward the transfer section 35 (secondary transfer position NT) described later. In other words, the unwinding roll 51 functions as a supply section that supplies the continuous recording medium P toward the transfer section 35 (secondary transfer position NT), which will be described later.

Winding rolls 52, 54, and 56 are rolls around which the continuous recording medium P is wound. Specifically, the winding rolls 52, 54, and 56 are wound around the continuous recording medium P between the unwinding roll 51 and a transfer section 35 (secondary transfer position NT) described later. As a result, a conveying path of the continuous recording medium P from the unwinding roll 51 to the transfer section 35, which will be described later, is determined.

The winding roll 53 is a roll on which the continuous recording medium P is wound. A leading end portion (downstream portion in the conveying direction) of the continuous recording medium P is wound around the take-up roll 53 . The take-up roll 53 is rotationally driven in one direction (the direction of arrow D in FIG. 1) by the drive unit 55 . As a result, the winding roll 53 winds the continuous recording medium P. In other words, the take-up roll 53 functions as a recovery section that recovers the continuous recording medium P from the transfer section 35 (secondary transfer position NT) described later.

Then, the continuous recording medium P is pulled by the winding roll 53 winding the continuous recording medium P, and the unwinding roll 51 unwinds the continuous recording medium P. In this manner, the winding roll 53 winds the continuous recording medium P and the unwinding roll 51 unwinds the continuous recording medium P by the rotational driving of the drive unit 55, thereby applying tension to the continuous recording medium P. It is conveyed in the conveying direction (the direction of arrow B in FIG. 1).

(Image forming unit 12)
The image forming section 12 is a section having a function of forming an image on the continuous recording medium P by electrophotography. Specifically, the image forming section 12 has a toner image forming section 20 that forms a toner image, and a transfer device 30 that transfers the toner image formed by the toner image forming section 20 onto the continuous recording medium P. ing.

A plurality of toner image forming units 20 are provided so as to form a toner image for each color. In this embodiment, a total of four color toner image forming units 20 of yellow (Y), magenta (M), cyan (C), and black (K) are provided. (Y), (M), (C), and (K) shown in FIG. 1 indicate components corresponding to the respective colors. In the image forming apparatus 10, when it is necessary to distinguish between yellow (Y), magenta (M), cyan (C), and black (K), Y, M, C, and K are added after each member code. Y, M, C, and K may be omitted if there is no need to distinguish between colors.

[Toner image forming unit 20]
The toner image forming units 20 for each color are basically configured in the same manner except for the toner used. Specifically, as shown in FIG. 2, the toner image forming unit 20 for each color includes a photoreceptor drum 21 (photoreceptor) that rotates clockwise in FIG. 22 and an exposure device 23 that exposes the photosensitive drum 21 charged by the charger 22 to form an electrostatic latent image on the photosensitive drum 21 . Further, the toner image forming unit 20 for each color includes a developing device 24 that develops the electrostatic latent image formed on the photosensitive drum 21 by the exposure device 23 to form a toner image, and a toner image onto a transfer belt 31, which will be described later. and a blade 25 as a remover for removing toner remaining on the surface of the photosensitive drum 21 after the transfer.

The charger 22 negatively charges the surface (photosensitive layer) of the photosensitive drum 21, for example. The negatively charged surface of the photosensitive drum 21 becomes positive in the portion irradiated with the exposure light L by the exposure device 23 , and an electrostatic latent image is formed on the surface of the photosensitive drum 21 . Then, the toner triboelectrically charged to have a negative polarity in the developing device 24 adheres to the electrostatic latent image exhibiting a positive polarity to develop the electrostatic latent image. Thus, a toner image is formed on the surface (peripheral surface) of the photosensitive drum 21 . The blade 25 contacts the surface of the photoreceptor drum 21 and scrapes off the toner remaining on the surface of the photoreceptor drum 21 .

[Transfer device 30]
The transfer device 30 superimposes and primarily transfers the toner images of the photosensitive drums 21 of each color onto a transfer belt 31 as an intermediate transfer member, and continuously transfers the superimposed toner images at a secondary transfer position NT (nip portion). Secondary transfer is performed on the recording medium P. Specifically, the transfer device 30 includes a transfer belt 31, a primary transfer roll 33, and a transfer section 35, as shown in FIG.

[Transfer belt 31]
As shown in FIG. 1, the transfer belt 31 has an endless shape and is wrapped around a plurality of rolls 32 to determine its posture. In this embodiment, the transfer belt 31 is in the shape of an inverted obtuse triangle elongated in the width direction of the device when viewed from the front. Among the plurality of rolls 32, the roll 32D shown in FIG. 1 functions as a driving roll that rotates the transfer belt 31 in the arrow A direction by the power of a motor (not shown). The transfer belt 31 rotates in the direction of arrow A to convey the primarily transferred image to the secondary transfer position NT.

Among the plurality of rolls 32 , the roll 32 T shown in FIG. 1 functions as a tension imparting roll that imparts tension to the transfer belt 31 . Among the plurality of rolls 32, the roll 32B shown in FIG. 1 functions as the opposing roll 32B of the secondary transfer roll 34. As described above, the opposite roll 32B is wrapped around the top of the lower end of the transfer belt 31, which forms an obtuse angle and is in the shape of an inverted obtuse triangle. The transfer belt 31 is in contact with the photoreceptor drums 21 of the respective colors from below at the upper side portion extending in the width direction of the apparatus in the posture described above.

[Primary transfer roll 33]
The primary transfer roll 33 is a roll that transfers the toner image of each photosensitive drum 21 onto the transfer belt 31, and is arranged inside the transfer belt 31 as shown in FIG. Each primary transfer roll 33 is arranged to face the photosensitive drum 21 of the corresponding color with the transfer belt 31 interposed therebetween. A primary transfer voltage is applied between the primary transfer roll 33 and the photoreceptor drum 21 by a power supply section 37 (see FIG. 2). As a result, the toner image formed on the photoreceptor drum 21 is transferred to the transfer belt 31 at the primary transfer position T (see FIG. 2) between the photoreceptor drum 21 and the primary transfer roll 33 .

[Transfer section 35]
The transfer section 35 is an example of a transfer section to which a transfer voltage is applied to transfer an image onto a continuous recording medium. Specifically, the transfer section 35 has a function of transferring the toner image onto the continuous recording medium P by applying a transfer voltage. More specifically, the transfer section 35 has a secondary transfer roll 34 , the opposing roll 32</b>B described above, and an application section 39 .

As shown in FIG. 1, the secondary transfer roll 34 is arranged so as to sandwich the transfer belt 31 between itself and the opposing roll 32B. are in contact with A secondary transfer position NT is defined between the secondary transfer roll 34 and the transfer belt 31 that are in contact with each other in this way. The continuous recording medium P is supplied from the unwind roll 51 to the secondary transfer position NT. The secondary transfer roll 34 is rotated clockwise in FIG.

Further, a secondary transfer voltage is applied by the applying section 39 between the secondary transfer roll 34 and the opposing roll 32B. As a result, a potential difference is generated between the toner image transferred onto the transfer belt 31 and the continuous recording medium P conveyed to the secondary transfer position NT. That is, a voltage is applied along the thickness direction of the continuous recording medium P between the continuous recording medium P and the toner image at the secondary transfer position NT. As a result, an electrostatic force acts on the negative toner image superimposed on the transfer belt 31, and the toner image is transferred from the transfer belt 31 onto the continuous recording medium P passing through the secondary transfer position NT.

By transferring the toner image onto the continuous recording medium P in the transfer unit 35 in this manner, the image surface 2A of the continuous recording medium P to which the negative toner image is transferred is negative, as shown in FIG. The non-image surface 2B is positively charged. In FIG. 3, in order to make the configuration easier to understand, a gap is provided between the transfer belt 31 and the continuous recording medium P, and between the continuous recording medium P and the secondary transfer roll 34. there is

(Fixing device 60)
Fixing device 60 is an example of a fixing device that fixes an image onto a continuous recording medium. Specifically, the fixing device 60 is an example of a fixing device that fixes the image onto the continuous recording medium conveyed to the conveying section and onto which the image has been transferred.

As shown in FIG. 1, the fixing device 60 is arranged downstream of the secondary transfer position NT in the conveying direction of the continuous recording medium P. As shown in FIG. The fixing device 60 has a first support portion 57, a fixing portion 61, a first adsorption portion 82, a second adsorption portion 84, and a second support portion 102, as shown in FIG. ing. Each part (the first support portion 57, the fixing portion 61, the first adsorption portion 82, the second adsorption portion 84, and the second support portion 102) of the fixing device 60 will be described below.

[First support portion 57]
The first support portion 57 shown in FIG. 4 is a portion having a function of supporting the continuous recording medium P. As shown in FIG. Specifically, the first support portion 57 has a function of supporting the continuous recording medium P between the secondary transfer position NT (see FIG. 1) and the fixing portion 61 . More specifically, the first support section 57 has support rolls 58, 59 as shown in FIG.

The support rolls 58 and 59 are arranged between the secondary transfer position NT and the fixing section 61 in this order from the upstream side in the transport direction. The support rolls 58 and 59 support the continuous recording medium P by contacting the non-image surface 2B of the continuous recording medium P with their outer peripheral surfaces. As a result, the continuous recording medium P is transported from the secondary transfer position NT to the fixing section 61 along a predetermined transport path.

Further, the support rolls 58 and 59 are configured to rotate as the continuous recording medium P moves. Further, the support roll 59 is configured to apply tension to the continuous recording medium P by moving in the thickness direction (arrow H direction) of the continuous recording medium P by a moving mechanism (not shown).

[Fixing unit 61]
A fixing unit 61 shown in FIG. 4 is an example of a fixing unit that heats and fixes an image on a continuous recording medium conveyed in a predetermined conveying direction.

Specifically, the fixing unit 61 heats the non-image surface 2B of the continuous recording medium P, and then presses and heats the image surface 2A and the non-image surface 2B of the continuous recording medium P to continuously record toner images. It has a function of fixing to the medium P. More specifically, the fixing section 61 has a first heating section 62 and a second heating section 63, as shown in FIG.

[First heating unit 62]
The first heating section 62 shown in FIG. 4 is a section having a function of heating the non-image surface 2B of the continuous recording medium P. As shown in FIG. The first heating section 62 starts heating the non-image surface 2B of the continuous recording medium P before the second heating section 63 heats the continuous recording medium P. In other words, the first heating section 62 starts heating the non-image surface 2B on the upstream side of the second heating section 63 in the transport direction.

Specifically, the first heating unit 62 is composed of a heating roll that heats the non-image surface 2B of the continuous recording medium P. As shown in FIG. The first heating unit 62, which is a heating roll, is in contact with the non-image surface 2B of the continuous recording medium P at its outer peripheral surface. Specifically, the non-image surface 2B of the continuous recording medium P is wrapped around the first heating section 62 within a predetermined range.

The first heating unit 62 includes, for example, a cylindrical roll 62A and a heat source 62B arranged inside the roll 62A. The roll 62A is configured to rotate as the continuous recording medium P moves. The heating source 62B is composed of, for example, a single halogen lamp or multiple halogen lamps.

A temperature sensor 66 is arranged at a position facing the outer peripheral surface of the first heating section 62 (the facing section through which the continuous recording medium P does not pass). The control unit 100 controls the first heating unit 62 to a predetermined temperature based on the temperature detected by the temperature sensor 66 .

[Second heating unit 63]
The second heating section 63 is a section having a function of heating the image surface 2A of the continuous recording medium P. As shown in FIG. The second heating unit 63 heats the image surface 2A of the continuous recording medium P after the first heating unit 62 starts heating the continuous recording medium P.

Specifically, the second heating section 63 has a heating roll 64 , an external heating roll 70 and a cleaning section 73 . The heating roll 64 is a roll that heats the image surface 2A of the continuous recording medium P. As shown in FIG. Specifically, the heating roll 64 is configured as follows.

The heating roll 64 is in contact with the image surface 2A of the continuous recording medium P at a position downstream of the contact area where the first heating unit 62 contacts the non-image surface 2B of the continuous recording medium P. That is, the heating roll 64 is arranged downstream from the center of the conveying direction in the contact area of the first heating section 62 with respect to the continuous recording medium P. As shown in FIG. Specifically, the heating roll 64 is in contact with the image surface 2A of the continuous recording medium P at the most downstream position of the contact area of the first heating section 62 with respect to the continuous recording medium P. As shown in FIG. As a result, the heating roll 64 and the first heating unit 62 sandwich the continuous recording medium P and apply pressure to the continuous recording medium P. As shown in FIG.

The heating roll 64 includes, for example, a cylindrical roll 64A whose surface side is made of a material having elasticity, and a heat source 64B arranged inside the roll 64A. The roll 64A is, for example, a soft roll whose surface is made of silicone rubber or the like. Further, the roll 64A is configured to rotate as the continuous recording medium P moves. The heat source 64B is composed of, for example, a single halogen lamp or multiple halogen lamps.

A temperature sensor 68 is arranged at a position facing the outer peripheral surface of the heating roll 64 (a facing portion through which the continuous recording medium P does not pass). The control unit 100 controls the first heating unit 62 to a predetermined temperature based on the temperature detected by the temperature sensor 68 .

The external heating roll 70 is a roll that heats the heating roll 64 . Specifically, the external heating roll 70 is configured as follows.

The external heating roll 70 is arranged on the side opposite to the first heating section 62 with respect to the heating roll 64 . The external heating roll 70 includes, for example, a cylindrical roll 70A made of metal and a heating source 70B such as a halogen lamp disposed inside the roll 70A. The roll 70A is configured to rotate following the rotation of the heating roll 64 . The heat source 70B is composed of, for example, a single halogen lamp or a plurality of halogen lamps.

A temperature sensor 72 is arranged at a position facing the outer peripheral surface of the external heating roll 70 . The controller 100 controls the temperature of the external heating roll 70 to a predetermined temperature based on the temperature detected by the temperature sensor 72 .

The cleaning part 73 is a part having a function of cleaning the heating roll 64 . The cleaning section 73 specifically includes a cleaning roll 74 , a cleaning web 76 and a roll 78 .

The cleaning roll 74 rotates in contact with the outer peripheral surface of the heating roll 64 to remove deposits on the outer peripheral surface of the heating roll 64 . Cleaning web 76 is pressed against the outer peripheral surface of cleaning roll 74 by roll 78 . The cleaning web 76 moves along the circumferential direction of the cleaning roll 74 such that a new surface is supplied to clean the cleaning roll 74 .

[Fixing operation of fixing unit 61]
In the fixing section 61, first, the first heating section 62 heats the continuous recording medium P and the toner image G (see FIG. 4) from the non-image surface 2B side of the continuous recording medium P. As shown in FIG. Next, on the downstream side of the first heating unit 62 in the conveying direction, the heating roll 64 and the first heating unit 62 pressurize the continuous recording medium P and the toner image G (see FIG. 4) with the continuous recording medium P interposed therebetween. heat up. As a result, the toner image G formed on the continuous recording medium P is fixed on the continuous recording medium P. As shown in FIG. In FIG. 4, only part of the toner image G formed on the continuous recording medium P is illustrated.

No peeling member is provided at the exit of the fixing section 61, that is, at the exit of the sandwiched portion (contact portion) between the first heating section 62 and the heating roll 64, which are in contact with each other with the continuous recording medium P therebetween. In other words, the outlet of the fixing section 61 is not provided with a contact member (for example, a claw or a baffle) that contacts the continuous recording medium P. FIG.

[First adsorption part 82]
The first adsorption section 82 shown in FIG. 4 is an example of an adsorption section (first adsorption section) that adsorbs the continuous recording medium to itself by electrostatic force, immediately downstream in the conveying direction with respect to the fixing section.

The term "directly downstream of the fixing section in the conveying direction" refers to a position downstream of the fixing section in the conveying direction where there is no other member that contacts the continuous recording medium between the fixing section and the fixing section. If there is no other member between the fixing section and the fixing section, the distance from the fixing section is irrelevant.

The first attracting portion 82 has a function of attracting the non-image surface 2B of the continuous recording medium P to itself by electrostatic force, directly downstream of the fixing portion 61 in the conveying direction. Specifically, the first suction unit 82 is composed of a suction roll that suctions the non-image surface 2B of the continuous recording medium P to itself. More specifically, the first adsorption portion 82 is configured as follows.

The first adsorption part 82 is composed of a cylindrical roll made of metal or the like. The outer peripheral surface of the first suction portion 82 is in contact with the non-image surface 2B of the continuous recording medium P. As shown in FIG. Specifically, the non-image surface 2B of the continuous recording medium P is wrapped around the outer peripheral surface of the first suction portion 82 within a predetermined range. The contact length (wound length) of the continuous recording medium P with respect to the first suction portion 82 is set longer than the contact length (wound length) of the continuous recording medium P with respect to the first heating portion 62. .

In other words, the adsorption time (cooling time) of the non-image surface 2B of the continuous recording medium P by the first adsorption unit 82 is longer than the heating time of the non-image surface 2B of the continuous recording medium P by the first heating unit 62. there is

The first adsorption portion 82 is provided with an application portion 83 that applies a voltage to the first adsorption portion 82 . The first attracting portion 82 is charged by voltage application by the applying portion 83, and attracts the non-image surface 2B of the continuous recording medium P to its outer peripheral surface by electrostatic force. In other words, it can be said that the applying section 83 functions as a suction unit that causes the first suction section 82 to absorb the continuous recording medium P by applying a voltage.

Here, as described above, the transfer of the toner image in the transfer section 35 charges the continuous recording medium P. Therefore, in the present embodiment, the first adsorption section 82 is charged by applying voltage from the applying section 83 to the continuous recording medium. It is charged with a polarity opposite to that of P.

Specifically, since the non-image surface 2B of the continuous recording medium P is positively charged by the transfer of the toner image in the transfer section 35, the first adsorption section 82 is negatively charged in this embodiment. More specifically, for example, the applying unit 83 applies a voltage between the second attracting unit 84 and a facing member that faces the second attracting unit 84 with the continuous recording medium P therebetween, thereby performing the second attracting operation. The portion 84 is charged positively. As a result, the non-image surface 2B of the continuous recording medium P is attracted to the first attraction section 82 by electrostatic force.

In addition, the first attraction section 82 receives a voltage whose absolute value is smaller than the voltage value of the transfer voltage applied when the toner image is transferred to the continuous recording medium P in the transfer section 35 by the application section 83 . applied. Specifically, while the transfer voltage applied at the transfer unit 35 is, for example, in the range of 1000 V to 2000 V (including 1000 V and 2000 V), the voltage applied to the first adsorption unit 82 is For example, the range is from -900V to -500V (including -900V and -500V).

The first adsorption section 82 has a cooling mechanism 81 that cools the continuous recording medium P. As shown in FIG. Cooling here refers to actively cooling the continuous recording medium P (forced cooling), and does not include cooling the continuous recording medium P simply by contacting it (natural cooling).

Specifically, the cooling mechanism 81 is a mechanism that cools the continuous recording medium P by air cooling (heat exchange with air). More specifically, the cooling mechanism 81 has a duct 81A and a fan 81B as a mechanism for cooling the inside of the first adsorption portion 82, as shown in FIG. Duct 81A is formed in a cylindrical shape. One axial end of the duct 81A is connected to one axial end of the first adsorption portion 82 . The fan 81B is provided at the other axial end of the duct 81A. Rotation of the fan 81B causes air to flow inside the first suction section 82 via the duct 81A, thereby cooling the continuous recording medium P in contact with the first suction section 82 from the non-image surface 2B. there is

In addition, in FIG. 5, in order to make the configuration of the first adsorption portion 82 easier to understand, the axial direction part of the first adsorption portion 82 is schematically shown in a cut state. Although not shown, the first suction unit 82 has shafts extending on both sides in the axial direction, and is configured to rotate following the movement of the continuous recording medium P. As shown in FIG.

Furthermore, the cooling mechanism 81 has a plurality of (two in this embodiment) fans 94 as a mechanism for cooling the first adsorption portion 82 from the outside, as shown in FIG. The plurality of fans 94 are arranged at positions facing the regions of the first suction unit 82 that do not come into contact with the continuous recording medium P. As shown in FIG. Rotation of the plurality of fans 94 lowers the temperature of the first suction portion 82 , thereby cooling the continuous recording medium P and the toner image G by the first suction portion 82 . As described above, the first suction unit 82 cools the continuous recording medium P and the toner image G from the non-image surface 2B side by contacting the non-image surface 2B of the continuous recording medium P.

Note that the cooling mechanism 81 is not limited to the configuration described above. The cooling mechanism 81 has, for example, only one of a mechanism (a duct 81A and a fan 81B) for cooling from the inside of the first adsorption portion 82 and a mechanism (a fan 94) for cooling from the outside of the first adsorption portion 82. may be As a mechanism for cooling from inside the first adsorption portion 82, for example, a mechanism (water cooling) for cooling the continuous recording medium P from the non-image surface 2B by passing water through the inside of the first adsorption portion 82 may be used.

[Second adsorption part 84]
The second attracting portion 84 shown in FIG. 4 attracts the surface of the continuous recording medium opposite to the attracting surface to the first attracting portion directly downstream in the conveying direction with respect to the first attracting portion by electrostatic force. It is an example of a second adsorption part.

It should be noted that "immediately downstream in the conveying direction with respect to the first suction section" is downstream in the conveying direction with respect to the first suction section, and there is no other member that contacts the continuous recording medium between the first suction section. say the position. If there is no other member between it and the first suction part, the distance to the first suction part is irrelevant.

The second suction portion 84 is located immediately downstream of the first suction portion 82 in the conveying direction, and is the surface of the continuous recording medium P opposite to the suction surface of the first suction portion 82 (specifically, the image surface 2A). has a function of attracting itself by electrostatic force. Specifically, the second suction unit 84 is composed of a suction roll that suctions the image surface 2A of the continuous recording medium P to itself. More specifically, the second adsorption portion 84 is configured as follows.

The second adsorption part 84 is composed of a cylindrical roll made of metal or the like. The outer peripheral surface of the second suction portion 84 is in contact with the image surface 2A of the continuous recording medium P. As shown in FIG. Specifically, the image surface 2A of the continuous recording medium P is wrapped around the outer peripheral surface of the second suction portion 84 within a predetermined range.

Note that the contact length (winding length) of the continuous recording medium P with respect to the second suction portion 84 is the contact length (wound length) of the continuous recording medium P with respect to the first suction portion 82 and the continuous recording medium It is made smaller than the contact length (winding length) of P with respect to the first heating portion 62 .

In other words, the adsorption time (cooling time) of the image surface 2A of the continuous recording medium P by the second adsorption unit 84 is the adsorption time (cooling time) of the non-image surface 2B of the continuous recording medium P by the first adsorption unit 82, Also, it is shorter than the heating time of the non-image surface 2B of the continuous recording medium P by the first heating unit 62 .

Also, the outer diameter of the second adsorption portion 84 is smaller than the outer diameter of the first adsorption portion 82 . Furthermore, in the present embodiment, the winding angle of the continuous recording medium P around the second adsorption portion 84 is larger than the winding angle of the continuous recording medium P around the first adsorption portion 82 .

The second adsorption portion 84 is provided with an application portion 85 that applies a voltage to the second adsorption portion 84 . The second attracting portion 84 is charged by voltage application by the applying portion 85, and attracts the image surface 2A of the continuous recording medium P to its own outer peripheral surface by electrostatic force. In other words, it can be said that the applying section 85 functions as a suction unit that causes the second suction section 84 to absorb the continuous recording medium P by applying a voltage.

Here, as described above, the transfer of the toner image in the transfer section 35 charges the continuous recording medium P. Therefore, in the present embodiment, the second adsorption section 84 is charged by applying voltage from the applying section 85 to the continuous recording medium. It is charged with a polarity opposite to that of P.

Specifically, since the image surface 2A of the continuous recording medium P is negatively charged by the transfer of the toner image in the transfer unit 35, the second attracting unit 84 is positively charged in this embodiment. More specifically, for example, the applying unit 85 applies a voltage between the second attracting unit 84 and a facing member that faces the second attracting unit 84 with the continuous recording medium P therebetween, thereby performing the second attracting operation. The portion 84 is charged positively. As a result, the image surface 2A of the continuous recording medium P is attracted to the second attraction portion 84 by electrostatic force. Thus, the first adsorption portion 82 and the second adsorption portion 84 are charged with opposite polarities.

Further, the voltage having a voltage value whose absolute value is smaller than the voltage value of the transfer voltage applied in the transfer portion 35 is applied by the application portion 85 to the second adsorption portion 84 . Specifically, while the transfer voltage applied at the transfer unit 35 is, for example, in the range of 1000 V to 2000 V (including 1000 V and 2000 V), the voltage applied to the second adsorption unit 84 is For example, the range is from -900V to -500V (including -900V and -500V).

The second adsorption section 84 has a cooling mechanism 87 that cools the continuous recording medium P. As shown in FIG. Cooling here refers to actively cooling the continuous recording medium P (forced cooling), and does not include cooling the continuous recording medium P simply by contacting it (natural cooling).

Specifically, the cooling mechanism 87 is a mechanism that cools the continuous recording medium P by air cooling. More specifically, the cooling mechanism 87 has a duct 87A and a fan 87B as a mechanism for cooling the inside of the second adsorption portion 84, as shown in FIG. Duct 87A is formed in a cylindrical shape. One axial end of the duct 87A is connected to one axial end of the second adsorption portion 84 . The fan 87B is provided at the other axial end of the duct 87A. Rotation of the fan 87B causes air to flow inside the second suction section 84 via the duct 87A, thereby cooling the continuous recording medium P in contact with the second suction section 84 from the image surface 2A. .

In addition, in FIG. 5 , in order to make the configuration of the second adsorption portion 84 easy to understand, the second adsorption portion 84 is schematically shown in a state in which a part of the second adsorption portion 84 is cut in the axial direction. Although not shown, the second suction unit 84 has shafts extending on both sides in the axial direction, and is configured to rotate following the movement of the continuous recording medium P. As shown in FIG.

Furthermore, the cooling mechanism 87 has a fan 95 as a mechanism for cooling the first adsorption portion 82 from the outside, as shown in FIG. The fan 95 is arranged at a position facing the area of the second suction unit 84 that does not come into contact with the continuous recording medium P. As shown in FIG. Rotation of the fan 95 lowers the temperature of the second suction portion 84 , thereby cooling the continuous recording medium P and the toner image G by the second suction portion 84 . As described above, the second suction unit 84 contacts the image surface 2A of the continuous recording medium P immediately downstream of the first suction unit 82 in the conveying direction, thereby sucking the continuous recording medium P and the toner from the image surface 2A side. Cool the image G.

Note that the cooling mechanism 87 is not limited to the configuration described above. The cooling mechanism 87 has, for example, only one of a mechanism (duct 87A and fan 87B) for cooling from inside the second adsorption portion 84 and a mechanism (fan 95) for cooling from outside the second adsorption portion 84. may be As a mechanism for cooling from inside the second adsorption portion 84, for example, a mechanism (water cooling) for cooling the continuous recording medium P from the non-image surface 2B by passing water through the inside of the second adsorption portion 84 may be used.

[Second support part 102]
The second support portion 102 is a portion having a function of supporting the continuous recording medium P. As shown in FIG. Specifically, the second support portion 102 has a function of supporting the continuous recording medium P between the second adsorption portion 84 and the winding roll 53 . More specifically, the second support section 102 has support rolls 103 , 104 , 105 .

The support roll 103 is arranged below the second adsorption section 84 . The support roll 103 supports the continuous recording medium P by contacting the image surface 2A of the continuous recording medium P with its outer peripheral surface. Then, the support roll 103 changes the direction of the continuous recording medium P conveyed downward from the second adsorption portion 84 in the horizontal direction (right side in FIG. 4).

The support roll 104 is arranged on the lateral side of the support roll 103 (on the right side in FIG. 4). The support roll 104 supports the continuous recording medium P by contacting the image surface 2A of the continuous recording medium P with its outer peripheral surface. Then, the support roll 104 turns upward the continuous recording medium P conveyed in the horizontal direction (right side in FIG. 4) from the support roll 103 .

The support roll 105 is arranged above the support roll 104 . The support roll 105 supports the continuous recording medium P by contacting the non-image surface 2B of the continuous recording medium P with its outer peripheral surface. Then, the support roll 105 turns the direction of the continuous recording medium P transported upward from the support roll 104 in the horizontal direction (right side in FIG. 4) toward the take-up roll 53 .

The support rolls 103, 104, and 105 are configured to rotate as the continuous recording medium P moves.

<Image forming operation>
Next, the image forming operation on the continuous recording medium P by the image forming apparatus 10 will be described.

In this embodiment, first, for example, the user of the image forming apparatus 10 manually places the continuous recording medium P in the transport path of the image forming apparatus 10 in advance. The continuous recording medium P is, for example, unwound from an unwinding roll 51 and arranged from the unwinding roll 51 to a winding roll 53 along a conveying path.

In the image forming apparatus 10 shown in FIG. 1, the control section 100 that receives an image forming command operates each toner image forming section 20 and the like. As shown in FIG. 2 and the like, the photosensitive drum 21 of each color is charged by the charger 22 while being rotated. Also, the control unit 100 sends image data that has undergone image processing in the image signal processing unit to each exposure device 23 . Each exposure device 23 emits each exposure light L according to image data to expose each charged photosensitive drum 21 . Thereby, an electrostatic latent image is formed on the outer peripheral surface of each photoreceptor drum 21 . The electrostatic latent image formed on each photoreceptor drum 21 is developed by a developing device 24, and yellow (Y), magenta (M), cyan (C), and black (K) are applied to the photoreceptor drums 21 of respective colors. is formed.

The toner images of each color formed on the photosensitive drums 21 of each color are sequentially primary-transferred onto the rotating transfer belt 31 at each primary transfer position T by the primary transfer rollers 33 of each color. As a result, a toner image in which toner images of four colors are superimposed is formed on the transfer belt 31 . This superimposed toner image is conveyed to the secondary transfer position NT by the rotation of the transfer belt 31 . The superimposed toner image G (see FIG. 4) is transferred from the transfer belt 31 to the continuous recording medium P at the secondary transfer position NT.

The continuous recording medium P onto which the toner image G has been secondarily transferred is conveyed toward the fixing device 60 . In the fixing device 60, in the fixing section 61, the first heating section 62 first heats the continuous recording medium P and the toner image G (see FIG. 4) from the non-image surface 2B side of the continuous recording medium P. As shown in FIG. Next, on the downstream side of the first heating unit 62 in the conveying direction, the heating roll 64 and the first heating unit 62 pressurize the continuous recording medium P and the toner image G (see FIG. 4) with the continuous recording medium P interposed therebetween. heat up. As a result, the toner image G formed on the continuous recording medium P is fixed on the continuous recording medium P. As shown in FIG.

Furthermore, the continuous recording medium P is transported toward the first adsorption section 82 on the downstream side of the second heating section 63 . In the first adsorption portion 82, the continuous recording medium P is cooled from the non-image surface 2B. Further, the toner image G is cooled by bringing the second suction portion 84 into contact with the image surface 2A of the continuous recording medium P downstream of the first suction portion 82 in the conveying direction. Then, the continuous recording medium P cooled by the second adsorption portion 84 is taken up by the take-up roll 53 .

<Action and effect>
The action and effect of this embodiment will be described.

In this embodiment, as described above, in the fixing device 60, before the continuous recording medium P is heated by the second heating unit 63, the first heating unit 62 is brought into contact with the non-image surface 2B of the continuous recording medium P. Thus, the continuous recording medium P and the toner image G are heated.

Here, in the fixing device 200 (see FIG. 7) in which the non-image surface 2B of the continuous recording medium P is not heated before the continuous recording medium P is heated by the second heating unit 63, blisters occur as follows. sometimes.

FIG. 6 shows the state of the toner image G before fixing when the paper P1 is used as the continuous recording medium. As shown in FIG. 6, before fixing, a large number of substantially elliptical particles of toner T are placed on the paper P1 in various directions.

FIG. 7 shows a state in which the fixing device 200 heats and presses the toner image G on the paper P1. As shown in FIG. 7, the fixing device 200 includes a fixing roll 202 that heats the toner T on the paper P1, and a pressure member 204 that is arranged on the opposite side of the fixing roll 202 with the paper P1 therebetween. ing. In the fixing device 200, a heating section for pre-heating the toner image G is not provided on the upstream side of the nip portion between the fixing roll 202 and the pressing member 204. FIG. The toner image G on the paper P1 is pressed by the nip portion between the fixing roll 202 and the pressure member 204, so that the directions of the large number of substantially elliptical toners T are aligned (the toners T are arranged in order). Toner T is heated and pressurized.

FIG. 8 shows a state in which the toner image G is fixed on the paper P1. As shown in FIG. 8, the toner T (see FIG. 78) on the paper P1 is melted under pressure to fix the toner image G on the paper P1. At this time, the air in the toner image G escapes into the paper P1 (between the fibers of the paper P1) as indicated by the arrow.

FIG. 9 shows the state of the toner image G during fixation when the resin film P2 is used as the continuous recording medium. The resin film P2 is made of, for example, polyethylene terephthalate (PET) or polypropylene (PP). As shown in FIG. 9, when the toner image G on the resin film P2 is heated and pressed at the nip portion between the fixing roll 202 and the pressure member 204, the resin film P2 has a low air permeability, so that the toner image G is reduced. The air A1 in G cannot escape into the resin film P2. Therefore, a large amount of air A1 is trapped in the melted toner image G. As shown in FIG.

FIG. 10 shows the state after fixing the toner image G on the resin film P2. As shown in FIG. 10, the toner image G on the resin film P2 leaves the nip portion between the fixing roll 202 (see FIG. 9) and the pressing member 204 (see FIG. 9) and the pressure is released at the same time. Air A1 (see FIG. 9) flies out of the toner image G. As shown in FIG. As a result, a plurality of crater-like holes 210, ie, blisters, are generated on the surface of the toner image G. FIG.

On the other hand, in the fixing device 60 of the present embodiment, before the continuous recording medium P is heated by the second heating unit 63, the first heating unit 62 is applied from the non-image surface 2B of the continuous recording medium P to the non-pressurized state. , the toner in the toner image G on the continuous recording medium P melts from the side closer to the continuous recording medium P. As shown in FIG. Therefore, the air in the unfixed toner image G on the continuous recording medium P easily escapes from the surface side of the toner image G. As shown in FIG. Thus, in the fixing device 60, even when a resin film is used as the continuous recording medium P, the occurrence of blisters is suppressed compared to the fixing device 200. FIG.

In this manner, in the configuration in which the non-image surface 2B of the continuous recording medium P having no toner image is heated, blistering can be suppressed, but the continuous recording medium P easily reaches the softening point. For this reason, the continuous recording medium P is likely to soften, and the continuous recording medium P is likely to expand or contract. Furthermore, in the present embodiment, the continuous recording medium P is stretched easily in the conveying direction because tension is applied to the continuous recording medium P along the conveying direction. Even if the continuous recording medium P is plain paper, it may expand or contract due to heating.

Here, in the fixing device 60 of the present embodiment, the first attracting portion 82 is charged by voltage application, and attracts the continuous recording medium P charged by the transfer of the image in the transfer portion 35 by electrostatic force. . Specifically, the first attracting portion 82 attracts the continuous recording medium P to itself by electrostatic force, directly downstream of the fixing portion 61 in the conveying direction. As a result, the continuous recording medium P is restrained by the first suction portion 82 and the shape of the continuous recording medium P is maintained in a state of being sucked by the first suction portion 82 . Therefore, expansion and contraction of the continuous recording medium P heated in the fixing section 61 is suppressed compared to a structure in which the continuous recording medium P contacts a member arranged immediately downstream of the fixing section 61 in the conveying direction without being adsorbed. . In particular, in the present embodiment, although tension is applied to the continuous recording medium P along the conveying direction, the continuous recording medium P heated in the fixing section 61 is restrained from being stretched in the conveying direction.

As described above, in the present embodiment, the first adsorption portion 82 is charged by applying a voltage. It is made to be attracted to one attraction portion 82 by electrostatic force.

Further, in the present embodiment, the continuous recording medium P is attracted to the first attraction portion 82 using electrostatic force. Here, in the configuration for suction and adsorption using negative pressure, it is necessary to suck the continuous recording medium P onto the adsorption surface by sucking air through a plurality of holes formed in the adsorption surface. For this reason, in the continuous recording medium P attracted to the attraction surface, uneven cooling occurs between the portion in contact with the attraction surface and the portion facing the hole. As a result, uneven gloss may occur on the continuous recording medium P in some cases. On the other hand, since the continuous recording medium P is attracted to the first attracting portion 82 using electrostatic force, uneven cooling of the continuous recording medium P is less likely to occur than in the case where negative pressure is used to attract and attract the continuous recording medium P. .

Further, in the present embodiment, the first suction unit 82 sucks the non-image surface 2B of the continuous recording medium P to itself, so that the first suction unit 82 has a configuration in which the image surface 2A of the continuous recording medium P is attracted to itself. , the continuous recording medium P is cooled earlier than the image. As a result, the temperature of the continuous recording medium P can be lowered to a temperature lower than the softening point in a short period of time, as compared with the configuration in which the image surface 2A of the continuous recording medium P is attracted. As a result, expansion and contraction of the continuous recording medium P is suppressed.

Further, in the present embodiment, the application section 83 applies a voltage whose absolute value is smaller than the voltage value of the transfer voltage applied in the transfer section 35 to the first adsorption section 82 . Here, in the configuration (first configuration) in which a voltage having an absolute value equal to or greater than the voltage value of the transfer voltage is applied, discharge occurs in the minute gap 89 between the continuous recording medium P and the first adsorption portion 82 . sometimes. When discharge occurs in the gap 89 , the polarity of the positively charged non-image surface 2</b>B is reversed, and the continuous recording medium P may not be attracted to the first attraction portion 82 .

On the other hand, in the present embodiment, since a voltage whose absolute value is smaller than the voltage value of the transfer voltage is applied to the first adsorption portion 82, discharge occurs in the gap 89 compared to the first configuration. hard to do. Therefore, poor adsorption of the continuous recording medium P to the first adsorption portion 82 is suppressed.

Further, in the present embodiment, the first adsorption section 82 has a cooling mechanism 81 that cools the continuous recording medium P. As shown in FIG. Therefore, the continuous recording medium P can be cooled in a short time compared to the structure in which the first adsorption unit 82 naturally cools the continuous recording medium P.

The second attracting portion 84 directly downstream of the first attracting portion 82 in the conveying direction, the surface (image surface 2A) of the continuous recording medium P on the opposite side to the attracting surface to the first attracting portion 82 by electrostatic force. to be adsorbed. As a result, the continuous recording medium P is restrained by the second suction portion 84 and the shape of the continuous recording medium P is maintained in a state of being suctioned by the second suction portion 84 . Therefore, expansion and contraction of the continuous recording medium P heated in the fixing section 61 is suppressed as compared with the configuration in which the continuous recording medium P is adsorbed only by the first adsorption section 82 .

Further, in the present embodiment, the first adsorption portion 82 and the second adsorption portion 84 are charged with opposite polarities. Therefore, the continuous recording medium P whose polarities are different between the image surface 2A and the non-image surface 2B (front surface and back surface) can be attracted to the first suction portion 82 and the second suction portion 84 .

Further, in the present embodiment, the second adsorption section 84 has a cooling mechanism 87 that cools the continuous recording medium P. As shown in FIG. Therefore, the continuous recording medium P can be cooled in a short time compared to the configuration in which the second adsorption portion 84 cools the continuous recording medium P naturally.

<Modification>
In the present embodiment, the first attracting portion 82 is configured to be applied with a voltage, thereby electrifying the first attracting portion 82 and attracting the continuous recording medium P with an electrostatic force. do not have. For example, the first adsorption portion 82 may be configured to be grounded via a resistor. In this configuration, when the first adsorption portion 82 is triboelectrically charged by friction (rolling friction) with the continuous recording medium P, the electric charge is less likely to escape compared to the configuration in which the first adsorption portion 82 is grounded without a resistor. The medium P is attracted to the first attraction portion 82 by electrostatic force. As the resistor, it is preferable to use a high resistance of 100 MΩ or more.

Further, the first suction unit 82 may be configured to be rotationally driven with a speed difference with respect to the conveyed continuous recording medium P. Specifically, the first suction unit 82 is configured to rotate in the direction of arrow E so that the peripheral speed is slightly faster than the conveying speed of the continuous recording medium P, for example. Note that the first suction unit 82 may be configured to rotate in the direction of arrow E so that the peripheral speed is slightly slower than the conveying speed of the continuous recording medium P, for example. With this configuration, the first attracting portion 82 is triboelectrically charged by friction (sliding friction) with the continuous recording medium P, and the continuous recording medium P is attracted to the first attracting portion 82 by electrostatic force.

In other words, the first adsorption section 82 may be configured to be charged by friction with the continuous recording medium P. In this configuration, the continuous recording medium P is attracted by electrostatic force without applying a voltage to the first attracting portion 82 . That is, in this configuration, the continuous recording medium P can be attracted to the first attraction section 82 by electrostatic force without applying a voltage to the first attraction section 82 .

Moreover, in the present embodiment, the first adsorption unit 82 and the second adsorption unit 84 have the cooling mechanisms 81 and 87, but this is not the only option. For example, the first adsorption section 82 and the second adsorption section 84 may be configured to naturally cool the continuous recording medium P without having a cooling mechanism. In this configuration, the first adsorption portion 82 and the second adsorption portion 84 are at room temperature. That is, the first adsorption section 82 and the second adsorption section 84 are set to a temperature lower than the temperature (fixing temperature) of the continuous recording medium P heated by the first heating section 62 and the second heating section 63 .

Further, in the present embodiment, the fixing device 60 has the first adsorption portion 82 and the second adsorption portion 84, but the fixing device 60 has only one of the first adsorption portion 82 and the second adsorption portion 84. good too. In a configuration in which the fixing device 60 has only the second attracting portion 84, the second attracting portion 84 is an example of an attracting portion that attracts the continuous recording medium to itself by electrostatic force immediately downstream in the conveying direction with respect to the fixing portion. be.

In this embodiment, before the continuous recording medium P is heated by the second heating unit 63, the continuous recording medium P and the toner image G are heated by bringing the first heating unit 62 into contact with the non-image surface 2B of the continuous recording medium P. is heated, but it is not limited to this. For example, the non-image surface 2</b>B of the continuous recording medium P may not be heated before the continuous recording medium P is heated by the second heating unit 63 .

In the present embodiment, the first suction unit 82 and the second suction unit 84 are composed of suction rolls that rotate following the movement of the continuous recording medium P, but are not limited to this. The first suction part 82 and the second suction part 84 may be fixed suction rolls or pads.

In this embodiment, the continuous recording medium P is charged only by the transfer section 35, but the present invention is not limited to this. As shown in FIG. 11, for example, a dedicated charging device 90 for charging the continuous recording medium P may be provided separately from the transfer section 35 . In the configuration in which the continuous recording medium P is charged only by the transfer section 35, the chargeability of the continuous recording medium P fluctuates when the transfer voltage at the transfer section 35 is changed in consideration of the transferability of the toner image. In the case where the dedicated charging device 90 is provided, by changing the voltage of the charging device 90 in accordance with the change of the transfer voltage of the transfer section 35, variations in the chargeability of the continuous recording medium P are suppressed.

The present invention is not limited to the above-described embodiments, and various modifications, changes, and improvements are possible without departing from the scope of the invention. For example, the modifications shown above may be configured by appropriately combining a plurality of them.

2A image surface 2B non-image surface 10 image forming device 35 transfer unit 50 conveying unit 60 fixing device 61 fixing unit 81 cooling mechanism 82 first adsorption portion (an example of an adsorption portion, an example of a first adsorption portion)
84 second adsorption part (an example of the second adsorption part)
87 Cooling mechanism P Continuous recording medium

Claims (8)

a fixing unit that heats and fixes an image onto a continuous recording medium conveyed in a predetermined conveying direction;
an attracting portion that attracts the continuous recording medium to itself by electrostatic force, immediately downstream in the conveying direction with respect to the fixing portion;
with
The adsorption part is grounded via a resistor
Fixing device. 2. The fixing device according to claim 1, wherein the suction unit suctions the non-image surface of the continuous recording medium to itself. 3. The fixing device according to claim 1 , wherein the adsorption section has a cooling mechanism for cooling the continuous recording medium . a first adsorption section as the adsorption section;
a second attracting portion that attracts the surface of the continuous recording medium opposite to the surface attracting the first attracting portion to itself by electrostatic force, immediately downstream in the conveying direction with respect to the first attracting portion;
The fixing device according to any one of claims 1 to 3, comprising: 5. The fixing device according to claim 4, wherein the first attracting portion and the second attracting portion are charged with opposite polarities . 6. The fixing device according to claim 4, wherein the second adsorption section has a cooling mechanism for cooling the continuous recording medium . a conveying unit that conveys the continuous recording medium while applying tension to the continuous recording medium along the conveying direction;
The fixing device according to any one of claims 1 to 6, which fixes the image onto the continuous recording medium conveyed to the conveying unit and onto which the image has been transferred;
An image forming apparatus comprising: a transfer unit to which a transfer voltage is applied to transfer the image onto the continuous recording medium;
The fixing device has the attraction section that is charged with a polarity opposite to the polarity of the continuous recording medium charged by the transfer of the image at the transfer section.
The image forming apparatus according to claim 7.

Images