Patent Application
20160216689
This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2015-014595 filed Jan. 28, 2015.
The present invention relates to a cooling device, an image forming apparatus, and a cooling method.
According to an aspect of the invention, there is provided a cooling device that cools a continuous resin film, which is transported and onto which a toner image is transferred, after the toner image is heated so that the toner image is fixed to the resin film, the resin film to which the toner image is fixed being cooled in such a manner that an image surface side of the resin film is convexly curved.
Exemplary embodiments of the present invention will be described in detail based on the following figure, wherein:
A cooling device 80 and an image forming apparatus 10 according to a first exemplary embodiment of the present invention will be described with reference to
As illustrated in
The feeder device 12 feeds the film F to the image forming section 14. The feeder device 12 includes a feed roller 20 around which the film F is wound into a roll.
The container device 16 contains the film F having the toner image formed thereon by the image forming section 14. The container device 16 includes a take-up roller 22 that is rotated by a driving unit (not shown) and around which the film F having the toner image formed thereon is wound into a roll, and a dancer roller 23 that adjusts the tension applied to the film F. The take-up roller 22 is an example of a transport unit that transports the film F.
The image forming section 14 forms a toner image on the film F on the basis of image information by using toners of four colors, which are yellow (Y), magenta (M), cyan (C), and black (K).
The image forming section 14 includes image forming devices 24, which are examples of image forming units that form a toner image, and an intermediate transfer device 26, which is an example of a transfer unit. The toner images formed by the image forming devices 24 are transferred onto the intermediate transfer device 26 in a first transfer process, and are then transferred onto the film F by the intermediate transfer device 26 in a second transfer process. The image forming section 14 also includes a fixing device 28 that fixes, by applying heat and pressure, the toner images that have been transferred onto the film F by the intermediate transfer device 26 in the second transfer process, and a cooling device 80 that cools a portion of the film F to which the toner images have been fixed.
Four image forming devices 24Y, 24M, 24C, and 24K that form the toner images of the respective colors, which are yellow (Y), magenta (M), cyan (C), and black (K), are provided as the image forming devices 24. The image forming devices 24 of the respective colors have similar structures except for the toner that is used. In the following description, when it is not necessary to distinguish the image forming devices, the letters “Y”, “M”, “C”, and “K” appended to the reference numeral 24 will be omitted.
As illustrated in
The image forming device 24 also includes a transfer roller 40 and a cleaning device 42. The transfer roller 40 transfers the toner image on the image carrier 30 onto a transfer belt 46 in the first transfer process. The transfer belt 46 is included in the intermediate transfer device 26, and rotates in the direction of arrow B in
As illustrated in
With this structure, the toner images formed by the image forming devices 24 are successively transferred onto the transfer belt 46 that rotates in the first transfer process, so that the toner images are superposed on the transfer belt 46.
As illustrated in
The roller 48C is arranged so that the transfer belt 46 is in contact with the film F that is transported. The intermediate transfer device 26 also includes a transfer roller 50 that transfers the toner images formed on the transfer belt 46 onto the film F in the second transfer process.
In this structure, the intermediate transfer device 26 transfers the toner images formed on the transfer belt 46 onto the film F in the second transfer process.
As illustrated in
The heating unit 54 includes a pair of rollers 54A and a fixing belt 54C arranged so as to extend around the rollers 54A. At least one of the rollers 54A has a halogen heater (not shown) disposed therein. In addition, at least one of the rollers 54A receives a rotating force from a driving member (not shown).
In this structure, the fixing device 28 fixes the toner images that have been transferred onto the film F in the second transfer process to the film F while the film F is nipped and transported. At this time, the film F is heated to a temperature higher than the softening temperature of the film F.
Next, an operation performed by the image forming apparatus 10 to form a toner image on the film F will be described.
The controller 18 controls each of the devices so that the image forming devices 24 form toner images of the respective colors. The toner images formed by the image forming devices 24 are successively transferred onto the transfer belt 46 that rotates in the first transfer process, so that the toner images are superposed on the transfer belt 46.
The intermediate transfer device 26 transfers the toner images formed on the transfer belt 46 onto the film F fed from the feeder device 12 in the second transfer process. The fixing device 28 fixes the toner images to the film F, and the cooling device 80 cools the film F.
The container device 16 receives the film F that has been cooled by the cooling device 80. Thus, the process of forming a toner image on the film F is completed.
The cooling device 80 and other devices will now be described.
As illustrated in
As illustrated in
The support surface 84A is convexly curved upward when viewed in the depth direction of the apparatus (width direction of the film F). When viewed in the depth direction of the apparatus, the curvature of the support surface 84A gradually decreases from the upstream side to the downstream side in a transporting direction in which the film F is transported.
The heat dissipation plates 86, which have surfaces that face in the width direction of the apparatus, are connected to the back surface of the support plate 84 (surface opposite the support surface 84A) at the proximal ends thereof. The heat dissipation plates 86 are arranged with constant intervals therebetween in the width direction of the apparatus.
As illustrated in
More specifically, the fan 91 cools the film F at the non-image surface side of the film F to a temperature lower than or equal to the softening temperature of the film F. The softening point of the film F is close to the glass transition point of the film F.
The pressing member 92 is located downstream of the support member 82 in the transporting direction of the film F, and includes a roller 94 capable of rotating while being in contact with the film F at the upper side of the film F.
In this structure, when the roller 94 is at a pressing position, which will be described below, the roller 94 presses the film F downward so that the non-image surface side of the film F comes into contact with the support surface 84A of the support plate 84 and the film F is supported by the support plate 84. Accordingly, the image surface side of the film F is convexly curved when viewed in the depth direction of the apparatus.
The image forming apparatus 10 includes a switching unit 88 that switches a path of a recording medium between a first transport path (see
The switching unit 88 includes rails 96 that are disposed on both sides of the roller 94 and that support the roller 94 such that the roller 94 is movable in the vertical direction, and a driving member 98 that moves the roller 94 along the rails 96. The operation of the driving member 98 is controlled by the above-described controller 18 (see
In this structure, the controller 18 operates the driving member 98 so as to move the roller 94 between the pressing position illustrated in
The image forming apparatus 10 also includes an input unit 62 (see
In this structure, when the medium type input through the input unit 62 differs from the film F, and when the roller 94 is at the pressing position, the controller 18 operates the driving member 98 to move the roller 94 to the separating position, as illustrated in
The operation will now be described. In the initial state, the roller 94 is at the pressing position, and the film F is transported along the first transport path.
The fixing device 28 fixes the toner image that has been transferred onto the film F in the second transfer process to the film F by applying heat and pressure. More specifically, the film F is transported while being nipped between the fixing belt 54C that is heated and the pressing roller 56, so that the toner image is fixed to the film F. Since the film F is heated by the fixing device 28 at the image surface side thereof, the temperature of the film F at the image surface side becomes higher than that at the non-image surface side.
After the toner image has been fixed to the film F, the roller 94 causes the non-image surface side of the film F to come into contact with the support surface 84A, as illustrated in
A case in which a recording medium of the type other than the film F (label paper) is used will now be described. A label paper is a sheet in which backing paper, an adhesive layer, and a surface material are stacked together.
In the case where the medium type input through the input unit 62 is label paper R, which differs from the film F, the controller 18 controls the driving member 98 so as to move the roller 94 to the separating position, as illustrated in
The controller 18 does not activate the cooling member 90.
An image forming apparatus including the cooling device according to the present exemplary embodiment is evaluated. In addition, an image forming apparatus which does not include the cooling device is also evaluated as an image forming apparatus according to a comparative example to be compared with the present exemplary embodiment.
1. Color 1000 Press manufactured by Fuji Xerox Co., Ltd. is used as each of the image forming apparatuses. The cooling device 80 is disposed downstream of a fixing device in the image forming apparatus according the present exemplary embodiment, and the cooling device 80 is not included in the image forming apparatus according to the comparative example. The fixing device heats the toner image on the film F (recording medium) at 160° C.
2. The film F used as the recording medium is Bonset (EPS45T) manufactured by C.I. Kasei Co., Ltd., which is a 50 μm thick polystyrene resin film having a softening point of 100° C. Here, Bonset (EPS45T) is a shrink film that shrinks in a transporting direction (longitudinal direction) when heated.
3. With regard to the shape of the support plate 84 of the support member 82, in
4. In the state in which the film F that is transported is supported by the support member 82, the fan 91 cools the support member 82 such that the temperature of the support surface 84A is 120° C. in an upstream region thereof and 90° C. in a downstream region thereof.
5. A black solid image (area coverage (image density) 100%) is formed on the film F as the toner image.
6. The speed at which the film F is transported is 60 m/min.
The shrinkage ratio in the transporting direction and warping of the film F output from each image forming apparatus are evaluated. The shrinkage ratio is determined by cutting out a portion of the film F that has been output and measuring the distance between predetermined two points.
When the shrinkage ratio of the film F output from the image forming apparatus is less than 3.0% in the transporting direction of the film F, the film F is evaluated as “Good” since the commercial value thereof is not affected. When the shrinkage ratio is 3.0% or more, the film F is evaluated as “Bad” since the commercial value thereof is affected. Warping of the film F output from the image forming apparatus is visually evaluated.
In the image forming apparatus according to the present exemplary embodiment, the shrinkage ratio is 1.5% and the result of the evaluation is “Good”. In the image forming apparatus according to the comparative example, the shrinkage ratio is 4.0% and the result of the evaluation is “Bad”.
With regard to warping of the film F output from each image forming apparatus, warping of the film F output from the image forming apparatus according to the present exemplary embodiment is smaller than warping of the film F output from the image forming apparatus according to the comparative example.
In the image forming apparatus according to the comparative example, as illustrated in
Since the film F is heated by the fixing device at the image surface side thereof, the temperature of the film F is higher at the image surface side than at the non-image surface side. Therefore, as illustrated in
In the image forming apparatus according to the present exemplary embodiment, similar to the comparative example, since the film F is heated by the fixing device at the image surface side thereof, the temperature of the film F is higher at the image surface side than at the non-image surface side. However, in this state, as illustrated in
Therefore, shrinking of the film F is suppressed, and warping of the film F such that the image surface side thereof is concavely curved when viewed in the depth direction of the apparatus is also suppressed (see
In the case where the film F is cooled at the non-image surface side thereof, the film F may be more effectively cooled compared to the case where the film F is cooled at the image surface side thereof. In addition, warping of the film F due to the temperature of the film F being higher at the image surface side than at the non-image surface side is suppressed.
Moreover, since the film F is cooled in the state in which the image surface side of the film F is convexly curved, compared to the case in which the film F is not curved, warping of the film F due to the temperature of the film F being higher at the image surface side than that at the non-image surface side is more effectively suppressed.
The support surface 84A of the support member 82 is convexly curved when viewed in the depth direction of the apparatus. Therefore, in the case where the film F that shrinks in the transporting direction (longitudinal direction) when heated is used, compared to the case in which the support surface is convexly curved when viewed in the transporting direction of the film F, warping of the film F is more effectively suppressed.
The curvature of the support surface 84A gradually decreases from the upstream side to the downstream side in the transporting direction of the film F. Therefore, compared to the case in which the support surface has a constant curvature, warping of the film F along the support surface 84A is reduced.
In the image forming apparatus 10, when a recording medium of the type other than the film F (for example, label paper R) is used, the label paper R that is transported is separated from the support member 82. Therefore, in the case where, for example, an adhesive layer of the label paper R is partially exposed at the backing-paper side, the risk that the adhesive layer of the label paper R will adhere to the support member 82 is reduced.
A cooling device 100 and an image forming apparatus according to a second exemplary embodiment of the present invention will now be described with reference to
As illustrated in
The support surface 104A is convexly curved when viewed in the transporting direction of the film F. The curvature of the support surface 104A gradually decreases from the upstream side to the downstream side in the transporting direction of the film F.
The heat dissipation plates 106, which have surfaces that face in the width direction of the apparatus, are connected to the back surface of the support plate 104 (surface opposite the support surface 104A) at the proximal ends thereof. The heat dissipation plates 106 are arranged with constant intervals therebetween in the width direction of the apparatus.
In this structure, in the case where the film F that shrinks in the width direction of the film F when heated is used, compared to the case in which the support surface is convexly curved when viewed in the depth direction of the apparatus, warping of the film F is more effectively suppressed.
The effects of the second exemplary embodiment are similar to those of the first exemplary embodiment except for the effect provided because the support surface is convexly curved when viewed in the depth direction of the apparatus.
Although specific exemplary embodiments of the present invention have been described in detail, the present invention is not limited to the above-described exemplary embodiments. It is obvious to a person skilled in the art that various exemplary embodiments are possible within the scope of the present invention. For example, in the above-described first and second exemplary embodiments, the recording medium cooled by the cooling device 80 is the film F (shrink film). However, the recording medium is not limited to a shrink film as long as the recording medium is a resin-made film (resin film).
In addition, although the support member 82, 102 includes plural heat dissipation plates 86, 106 in the first and second exemplary embodiments, the heat dissipation plates may be omitted when a support member having a high thermal conductivity is used.
Although not described in the first and second exemplary embodiments, a member that directly presses the film F against the support surface 84A, 104A from above the support member 82, 102 by nipping the film F between itself and the support surface 84A, 104A may be additionally provided.
In addition, although not described in the first and second exemplary embodiments, the support surface 84A, 104A of the support member 82, 102 may be convexly curved not only when viewed in the depth direction of the apparatus but also when viewed in the transporting direction of the film F. Such a structure is effective in the case where the recording medium is a shrink film that shrinks in all directions when heated.
Although the roller 94 is moved by the driving member 98 in the above-described exemplary embodiments, the roller 94 may instead be moved by the user.
The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2015-014595 | Jan 2015 | JP | national |
