Fixing device and image forming system using the same

Abstract

By reusing some of the heat dissipated to cool the belt-shaped conveying and fixing mechanism for heating, the amount of heat required for heating and cooling itself is reduced. [Solution] The system comprises a heating and fixing means 1, a belt-shaped transport and fixing means 2 stretched over the heating and fixing means 1 and transporting the medium S in contact with the image surface of the medium S, a rotatable pressurizing and fixing means 3 that pressurizes the transport and fixing means 2 to form a fixing area FA between it and the heating and fixing means 1, a cooling means 4 provided downstream of the fixing area FA in the transport direction of the medium S and in contact with the back surface of the transport and fixing means 2 to cool the transport and fixing means 2, and a heat transfer means 6 provided in the internal space on the back surface of the transport and fixing means 2 in a non-contact state between the cooling means 4 and the heating and fixing means 1, and in contact with a first position P1 located in the region of the transport and fixing means 2 before heating and after cooling, and a second position P2 located in the region of the transport and fixing means 2 before heating and after cooling, and moves a portion of the heat of the transport and fixing means 2 from the first position P1 to the second position P2.

Description

Technical Field

[0001] The present invention relates to a fixing device and an image forming system using the same.

Background Art

[0002] As a conventional fixing device, for example, the one described in Patent Document 1 is already known. Patent Document 1 discloses a fixing device that performs good fixing without generating gloss unevenness due to blisters. This fixing device includes an endless fixing belt that rotates in a certain direction, heating means for heating this fixing belt, a pressure conveying belt that rotates in the same direction by a predetermined distance while being in pressure contact with the surface of this fixing belt and sandwiches and conveys a recording paper carrying an unfixed toner image to be fixed between the fixing belt, a first cooling means for cooling the recording paper that is in pressure contact with this pressure conveying belt and remains in close contact with the fixing belt, and a second cooling means for cooling the pressure conveying belt in a section from when it separates from the fixing belt until it contacts again. In this example, the first cooling means is constituted by a heat circulator, and it recovers the heat in the region where the fixing belt contacts the pressure conveying belt and returns it to the region where it does not contact the pressure conveying belt of the fixing belt and the recording paper.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] <00000​​[Means for solving the problem]

[0005] A first technical feature of the present invention is a fixing device comprising: a rotatable heating and fixing means having a heating source; a belt-shaped transport and fixing means stretched over the heating and fixing means and circulatingly provided, which transports a medium in contact with the image surface of a medium holding an unfixed image; a rotatable pressurizing and fixing means positioned opposite the heating and fixing means with the transport and fixing means in between, which pressurizes to form a fixing area for fixing the unfixed image between itself and the heating and fixing means; a cooling means provided in contact with the back surface of the transport and fixing means in the transport area of ​​the medium of the transport and fixing means downstream of the fixing area in the transport direction of the medium, and which cools the transport and fixing means; and a heat transfer means provided in the internal space of the back surface of the transport and fixing means in a non-contact state between the cooling means and the heating and fixing means, which contacts a first position located in the area of ​​the transport and fixing means before heating and before cooling, and a second position located in the area of ​​the transport and fixing means before cooling, and which moves a portion of the heat of the transport and fixing means from the first position to the second position.

[0006] A second technical feature of the present invention is a fixing device having the first technical feature, wherein the heat transfer means is equipped with a heat transfer component that transfers heat from a high-temperature part to a low-temperature part. A third technical feature of the present invention is a fixing device having the second technical feature, wherein the heat transfer means comprises: a first contact member made of a heat conductive material disposed in contact with the first position on the back surface of the transport fixing means and extending along an intersecting direction intersecting the direction of movement of the transport fixing means; a second contact member made of a heat conductive material disposed in contact with the second position on the back surface of the transport fixing means and extending along an intersecting direction intersecting the direction of movement of the transport fixing means; and a heat transfer component joined between the first contact member and the second contact member. A fourth technical feature of the present invention is a fixing device having the second technical feature, wherein the heat transfer components are provided in a plurality at intervals in a direction intersecting the conveying direction of the medium. A fifth technical feature of the present invention is a fixing device having the second technical feature, wherein the heat transfer component is a heat pipe. A sixth technical feature of the present invention is a fixing device having the first technical feature, wherein the heat transfer means is positioned closer to the cooling means than to the heating fixing means.

[0007] A seventh technical feature of the present invention is a fixing device having the first technical feature, characterized in that a holding means is provided to maintain the contact state between the heat transfer means and the conveying fixing means. The eighth technical feature of the present invention is a fixing device having the seventh technical feature, wherein the holding means is provided upstream of the second position of the transport fixing means in the direction of movement of the transport fixing means, and is a positioning means that positions the transport fixing means such that the heat transfer means maintains contact with the second position. The ninth technical feature of the present invention is a fixing device having the seventh technical feature, wherein it is provided with an opposing rotating means that is positioned opposite to the entrance of the cooling area by the cooling means, with the transport fixing means in between, and rotates in accordance with the transport fixing means, the holding means also serves as the opposing rotating means, and the heat transfer means maintains a state of contact with the first position. A tenth technical feature of the present invention is a fixing device having the first technical feature, wherein the heat transfer means has a thermal conductivity that reduces the temperature of the transport fixing means entering the cooling region by the cooling means by 5°C or more at the first position. The eleventh technical feature of the present invention is a fixing apparatus having the tenth technical feature, wherein the heat transfer means has a thermal conductivity such that, taking into account the amount of heating by the heating fixing means and the amount of heat dissipated by the cooling means, the temperature at the point where the medium is peeled from the transport fixing means is below the threshold temperature necessary to obtain a high-gloss fixed image.

[0008] The twelfth technical feature of the present invention is an image forming system comprising: an imaging means for creating an unfixed image on a medium; and a fixing device having any of the first to eleventh technical features for fixing the unfixed image held on the medium. [Effects of the Invention]

[0009] According to the first technical feature of the present invention, when fixing an unfixed image on a medium by heating and cooling a belt-shaped transport and fixing means, a portion of the heat dissipated to cool the transport and fixing means can be reused for heating, thereby reducing the amount of heat required for heating and cooling itself. According to a second technical feature of the present invention, a heat transfer means can be easily constructed by utilizing heat transfer components. According to the third technical feature of the present invention, a portion of the heat of the conveying and fixing means can be circulated substantially evenly over the entire area in the intersecting direction that intersects the direction of movement of the conveying and fixing means. According to the fourth technical feature of the present invention, compared to the case where a single heat transfer component is used, a portion of the heat of the transport and fixing means can be efficiently circulated by distributing it over the entire area in the intersecting direction that intersects the direction of movement of the transport and fixing means. According to the fifth technical feature of the present invention, a heat transfer means can be easily constructed by utilizing existing heat pipes as heat transfer components. According to the sixth technical feature of the present invention, the influence of heat from the heating and fixing means on the heat transfer means can be suppressed compared to a configuration in which the heat transfer means is arranged closer to the heating and fixing means. According to the seventh technical feature of the present invention, the heat transfer action by the heat transfer means can be stabilized compared to an embodiment without a holding means. According to the eighth technical feature of the present invention, even if the transport and fixing means vibrates or flexes under its own weight during movement, the contact state between the heat transfer means and the second position of the transport and fixing means can be stabilized. According to the ninth technical feature of the present invention, by using opposing rotating means in combination, the contact state between the heat transfer means and the first position of the conveying and fixing means can be stabilized. According to the tenth technical feature of the present invention, the performance of the heat transfer means can be easily selected based on the degree of temperature reduction at the first position of the transport and fixing means. According to the eleventh technical feature of the present invention, in order to obtain a high-gloss fixed image, the performance of the heat transfer means can be easily selected based on the temperature at the point where the medium is peeled from the transport and fixing means. According to the twelfth technical feature of the present invention, when fixing an unfixed image on a medium by heating and cooling a belt-shaped transport and fixing means, it is possible to construct an image forming system that includes a fixing device capable of reusing a portion of the heat dissipated to cool the transport and fixing means for heating, thereby reducing the amount of heat required for heating and cooling itself. [Brief explanation of the drawing]

[0010] [Figure 1] (a) is an explanatory diagram showing an overview of an embodiment of an image forming system including a fixing device to which the present invention is applied, and (b) is an explanatory diagram showing a typical embodiment of the heat transfer means shown in (a). [Figure 2] This is an explanatory diagram showing the overall configuration of the image forming system according to Embodiment 1. [Figure 3] (a) is an explanatory diagram showing the main parts of the second fixing device according to Embodiment 1, and (b) is an explanatory cross-sectional view of the conveyor fixing belt. [Figure 4] (a) is an explanatory diagram showing special paper for photographic images as an example of a medium, (b) is an explanatory diagram showing the state in which a toner image has been fixed onto the special paper, and (c) is an explanatory diagram showing the state in which a toner image has been fixed onto plain paper as an example of a medium. [Figure 5] (a) is an explanatory diagram showing a heat transfer device used in Embodiment 1, (b) is a view taken from direction B in (a), (c) is an explanatory cross-sectional view taken along line CC in (a), (d) is an explanatory diagram showing an example of the configuration of heat transfer components that are components of the heat transfer device, and (e) is an explanatory diagram schematically showing the operation of the heat transfer components. [Figure 6] This is an explanatory diagram showing the control system of the second fuser according to Embodiment 1. [Figure 7] This is an explanatory diagram showing the operation of the second fuser according to Embodiment 1. [Figure 8] (a) is an explanatory diagram showing the temperature change before and after the heat transfer device of the fixing conveyance belt of the second fixing device, (b) is an explanatory diagram showing the state where the medium passing through the second fixing device peels off from the fixing conveyance belt, and (c) is an explanatory diagram showing the state where the medium passing through the second fixing device according to Comparative Form 1 peels off from the fixing conveyance belt. [Figure 9] (a) is an explanatory diagram showing the main part of the second fixing device according to Embodiment 2, and (b) is an explanatory diagram showing the defect in the aspect without the holding roll shown in (a). [Figure 10] It is an explanatory diagram showing Modification 2-1 of the second fixing device according to Embodiment 2. [Figure 11] It is a graph showing the relationship between the peeling temperature of the medium and the glossiness of the medium image in the second fixing device according to Example 1. [Figure 12] (a) is a graph showing a measurement example of the first temperature T1 before the fixing conveyance belt passing through the fixing area reaches the heat transfer device and the second temperature T2 after passing through the heat transfer device in the second fixing device according to Example 2, and (b) is a graph showing a measurement example verifying the influence of the length in the medium conveyance direction of the cooling area CA of the cooler as a condition for reaching the peeling temperature Ts of the medium necessary for obtaining high gloss in the second fixing device according to Example 2.

Modes for Carrying Out the Invention

[0011] ◎ Outline of Embodiment FIG. 1(a) shows an outline of an embodiment of an image forming system including a fixing device to which the present invention is applied. In the figure, the image forming system includes an image forming means 11 for creating an unfixed image G on a medium S, and a fixing device 10 for fixing the unfixed image G held on the medium S. In this example, the fixing device 10 is a fixing device that heats and pressurizes a medium S holding an unfixed image G, then cools it to fix the unfixed image G, and comprises a rotatable heating and fixing means 1 having a heating source 1a, a belt-shaped transport and fixing means 2 stretched over the heating and fixing means 1 and circulatingly provided, which transports the medium S in contact with the image surface of the medium S, a rotatable pressurizing and fixing means 3 positioned opposite the heating and fixing means 1 with the transport and fixing means 2 in between, which pressurizes to form a fixing area FA between itself and the heating and fixing means 1, and the transport area of ​​the medium S of the transport and fixing means 2 The system includes a cooling means 4 provided in contact with the back surface of the transport fixing means 2 in the area downstream of the fixing area FA in the transport direction of the medium S, and for cooling the transport fixing means 2; and a heat transfer means 6 provided in a non-contact state between the cooling means 4 and the heating fixing means 1 in the internal space on the back surface of the transport fixing means 2, and for contact with a first position P1 located in the area of ​​the transport fixing means 2 before heating and before cooling, and a second position P2 located in the area of ​​the transport fixing means 2 before cooling and before heating, and for transferring a portion of the heat of the transport fixing means 2 from the first position P1 to the second position P2. In this example, the tensioning method of the transport and fixing means 2 includes a peeling means 5 that tensions the transport and fixing means 2 together with the heating and fixing means 1, as shown in Figure 1(a). This peeling means 5 is located downstream of the cooling means 4 in the transport direction of the medium S and is positioned to peel the medium S from the transport and fixing means 2. Note that the tensioning method of the transport and fixing means 2 is not limited to the configuration shown in Figure 1(a), and additional tensioning means not shown may be added.

[0012] In such technical means, the fixing device 10 of this embodiment may be incorporated into an image forming apparatus that includes an imaging means 11 for producing an unfixed image G, or it may be incorporated into a post-processing device separate from the image forming apparatus and configured as an image forming system consisting of multiple units. Furthermore, the heating and fixing means 1 includes, for example, a heating and fixing roll. The heating source 1a can be built-in or external. In addition, the conveying and fixing means 2 includes a belt-shaped member. Here, in order to obtain a highly glossy image such as a photograph, it is preferable that the belt-shaped member be, for example, an endless film made of thermosetting polyimide resin with a highly smooth coating layer formed on its surface. Furthermore, the pressure fixing means 3 can be roll-shaped or belt-shaped as long as it is pressurized to form a fixing area FA between itself and the heating and fixing means 1. The pressure fixing means 3 may have a heating source not shown if necessary. Furthermore, the cooling means 4 broadly includes any means that cools by contacting the back surface of the medium transport area of ​​the transport and fixing means 2. Primarily, a heat dissipation means that dissipates absorbed heat, such as a heat sink, is used.

[0013] In this example, the heat transfer means 6 can be installed between the cooling means 4 and the heating and fixing means 1. In this case, the heat transfer means 6 primarily focuses on transferring heat from the first position P1 to the second position P2 of the conveying and fixing means 2. For this reason, the heat transfer means 6 is installed in a non-contact manner with the cooling means 4 and the heating and fixing means 1. Furthermore, when installing the heat transfer means 6, it is not necessary for the entire heat transfer means 6 to be housed between the cooling means 4 and the heating and fixing means 1. For example, a portion of the heat transfer means 6 may be positioned in contact with the conveying and fixing means 2 while protruding into the space between the cooling means 4 and the conveying and fixing means 2.

[0014] Here, the first position P1 is located within the medium transport area of ​​the transport and fixing means 2, between the time the transport and fixing means 2 passes through the fixing area FA and before it reaches the cooling area CA provided by the cooling means 4. Furthermore, the second position P2 is generally located between the cooling means 4 and the heating and fixing means 1. However, in configurations where a portion of the heat transfer means 6 protrudes into the space between the cooling means 4 and the transport and fixing means 2, the second position P2 may be located in an exceptional position. In this case, the second position P2 may be located in the space between the cooling means 4 and the transport and fixing means 2, or beyond that space. However, it is undesirable for the medium S to be heated in the region between the cooling of the transport and fixing means 2 by the cooling means 4 and the peeling position of the medium S at the second position P2. For this reason, in this example, the second position P2 is selected to be located downstream in the rotational direction of the transport and fixing means 2 from the peeling position of the medium S.

[0015] Furthermore, in this example, a typical embodiment of the heat transfer means 6 is one that includes a heat transfer component 6c that transfers heat from a high-temperature section to a low-temperature section. A heat pipe is a typical example of the heat transfer component 6c, but it is not limited to a heat pipe and can be selected as appropriate. In addition, the heat transfer means 6 can be configured such that the heat transfer component 6c is in direct or indirect contact with the high-temperature section and the low-temperature section of the transport and fixing means 2. In this case, it is preferable that the heat from the high-temperature section and the low-temperature section of the transport and fixing means 2 is transferred substantially equally in a crossing direction that intersects the transport direction of the medium S of the transport and fixing means 2. Here, as an example of a preferred embodiment, as shown in Figure 1(b), there is an embodiment that includes a first contact member 6a, a second contact member 6b, and a heat transfer component 6c. In this example, the first contact member 6a is positioned in contact with a first position P1 on the back surface of the transport and fixing means 2 and is made of a heat conductive material that extends along an intersecting direction that intersects the direction of movement of the transport and fixing means 2. The second contact member 6b is positioned in contact with a second position P2 on the back surface of the transport and fixing means 2 and is made of a heat conductive material that extends along an intersecting direction that intersects the direction of movement of the transport and fixing means 2. One or more heat transfer components 6c are used and are joined between the first contact member 6a and the second contact member 6b.

[0016] Furthermore, in order to stabilize the heat transfer action by the heat transfer means 6, it is preferable to maintain good contact between the heat transfer means 6 and the transport and fixing means 2. In this case, as shown by the dashed line in Figure 1(a), the contact between the heat transfer means 6 and the transport and fixing means 2 can be maintained by the holding means 8. Here, the holding means 8 is provided, for example, upstream of the second position P2 of the transport and fixing means 2 in the direction of movement. The holding means 8 should function as a positioning means that positions the transport and fixing means 2 so that the heat transfer means 6 maintains contact with the second position P2.

[0017] Furthermore, in this example, the medium S is peeled off at a peeling position where the movement trajectory of the transport fixing means 2, which is stretched over the peeling means 5, changes from a straight shape to a curved shape. At this time, by setting the peeling temperature Ts of the medium S to below a predetermined threshold, a high-gloss image is obtained as the fixed image on the medium S. For this reason, in this example, it is preferable that the heat transfer means 6 has a thermal conductivity such that the peeling temperature Ts of the medium S is below the aforementioned threshold temperature. In this case, the thermal conductivity of the heat transfer means 6 should be selected based on the amount of heating by the heating fixing means 1 and the amount of heat dissipated by the cooling means 4.

[0018] Next, the operation of the fixing device 10 according to this embodiment will be described. In this example, the medium S passes through the fixing area FA of the fixing device 10. At this time, the unfixed image G on the medium S is heated and pressurized in the fixing area FA by the heating fixing means 1 and the pressurizing fixing means 3 to fix it. The medium S, having passed through the fixing area FA, is transported by the transport fixing means 2. At this time, the medium S undergoes a cooling treatment by the cooling means 4, and then is peeled off from the transport fixing means 2 at the peeling position by the peeling means 5. Thus, in this example, the unfixed image G on the medium S undergoes a series of fixing treatments: heating and pressurizing followed by cooling. Therefore, by using a special paper suitable for obtaining high-gloss images as the medium S and going through the series of fixing processes described above, it is possible to obtain high-gloss images.

[0019] In particular, in this example, a heat transfer means 6 is provided between a first position P1 and a second position P2 of the transport and fixing means 2. Here, the first position P1 is a high-temperature area, and the second position P2 is a low-temperature area after cooling by the cooling means 4. Therefore, heat is transferred from the high-temperature area, the first position P1, to the low-temperature area, the second position P2, through the heat transfer means 6. In this heat transfer process, heat Qin is absorbed from the transport and fixing means 2 to the heat transfer means 6 at the first position P1. Also, heat Qout is released from the heat transfer means 6 to the transport and fixing means 2 at the second position P2. At this time, the amount of heat Qout released is approximately the same as the amount of heat Qin absorbed. Here, if we denote the temperatures before and after the first position P1 of the transport and fixing means 2 as T1 and T2, respectively, the temperature T2 of the transport and fixing means 2 is lower than the temperature T1. Therefore, the transport and fixing means 2 enters the cooling region CA of the cooling means 4 at a lower temperature T2 than in the configuration without the heat transfer means 6. As a result, the degree of cooling by the cooling means 4 is kept to a minimum compared to the configuration without the heat transfer means 6. Furthermore, if the temperatures before and after the second position P2 of the transport and fixing means 2 are T3 and T4, respectively, then the temperature T4 of the transport and fixing means 2 rises above temperature T3. As a result, the transport and fixing means 2 returns to the heating range of the heating and fixing means 1 at a higher temperature T4 than in the configuration without the heat transfer means 6. Consequently, the degree of heating by the heating and fixing means 1 is kept to a minimum compared to the configuration without the heat transfer means 6.

[0020] Hereinafter, representative and preferred embodiments of a fixing device embodying the present invention will be described based on the embodiments shown in the attached drawings. ◎Embodiment 1 Figure 2 shows the overall configuration of the image forming system according to Embodiment 1. -Overall configuration of the image forming system- In the figure, the image forming system 15 has a main body 16 equipped with an image forming unit capable of forming color images. An optional post-processing device 50 is added to the top of the main body 16. On the other hand, a multi-stage media supply container 81 (81a, 81b) for supplying media such as paper is provided below the main body 16 and is retractable.

[0021] -Image Forming Unit- The image forming unit used in this embodiment employs, for example, an electrophotographic method and has a plurality of image forming units 20. The plurality of image forming units 20 form images of four colors, for example, yellow (Y), magenta (M), cyan (C), and black (K). In this example, each image forming unit 20 (20a to 20d) is arranged in parallel with a belt-shaped intermediate transfer body 30 in a so-called tandem configuration. Therefore, the toner images of each color formed in each image forming unit 20 (20a to 20d) are sequentially transferred onto, for example, the intermediate transfer body 30 and multiplexed. The multiplexed toner images are then transferred collectively onto a medium S transported from a medium supply container 81 and fixed onto the medium S. Note that the color arrangement of the four image forming units 20 is not limited to this order and may be in other orders.

[0022] <Image Forming Section> In this embodiment, the image forming unit 20 (20a to 20d) has a photoreceptor 21 as an image holder that forms and holds toner images of each color component. Around the photoreceptor 21 are a charger 22, an exposure unit 23, a developer unit 24, a primary transfer unit 25, a photoreceptor cleaner 26, and a static eliminator 27, etc. The charger 22 is composed of a charging roll or the like that charges the photoreceptor 21. The exposure unit 23 is composed of a laser scanner or LED array or the like that forms a latent image on the photoreceptor 21 that has been charged by the charger 22. Furthermore, the developer unit 24 includes a developing roll or the like that that develops the electrostatic latent image formed on the photoreceptor 21 with toners of each color component. The primary transfer unit 25 is positioned opposite the photoreceptor 21, with an intermediate transfer unit 30 in between. The primary transfer unit 25 is composed of, for example, a primary transfer roll or a corona discharge unit that primary transfers the toner image on the photoreceptor 21 onto the intermediate transfer unit 30. Furthermore, the photoreceptor cleaner 26 includes a cleaning member for cleaning residual toner remaining on the photoreceptor 21. In addition, the static eliminator 27 consists of a static elimination roll and a corona discharger that remove residual charge on the photoreceptor 21. In this embodiment, the exposure unit 23 is configured to expose the entire four-color image forming unit 20 (20a to 20d) with a single exposure unit.

[0023] <Intermediate Transfer Material / Secondary Transfer Device> The intermediate transfer body 30 is stretched over multiple tension rolls 31 and 32. For example, tension roll 31 acts as a drive roll to circulate and transport the intermediate transfer body 30. Tension roll 32 is positioned opposite to the secondary transfer unit 33, for example, as a backup roll. Furthermore, an intermediate transfer body cleaner 34 is installed at a position opposite the tension roll 31 of the intermediate transfer body 30 to remove residual toner from the intermediate transfer body 30. In this example, the secondary transfer unit 33 has, for example, a secondary transfer roll 33a that contacts the surface side of the intermediate transfer body 30 facing the tension roll 32. In this example, the secondary transfer unit 33 applies a secondary transfer electric field between the secondary transfer roll 33a and the tension roll 32 to transfer the image on the intermediate transfer body 30 to the medium S in one go (secondary) transfer. Furthermore, within the main body 16 of the device, toner boxes 35 corresponding to each developer 24 of each image forming unit 20 are provided above the intermediate transfer body 30. Each toner box 35 supplies toner to the developer 24 corresponding to the respective color via a transport path (not shown).

[0024] <Media transport system> Furthermore, the media transport system 80 in this embodiment is configured as follows: Media is fed from each media supply container 81 by a pickup roll 82. The media is then handled by a feed roll 83 and a retard roll 84, and only one sheet of media is transported into the downstream transport path. Alignment rolls 85 and a first fuser 40 are provided in the transport path. Alignment rolls 85 position and align the media S transported from the media supply container 81 before it enters the secondary transfer unit 33. The first fuser 40 fixes the unfixed toner image transferred onto the media by the secondary transfer unit 33. A switching member 86 for switching the transport path is provided downstream of the first fuser 40. In this example, the switching member 86 switches between two transport paths: one for the post-processing device 50 and the other for the first discharge receiver 87 which accommodates media directly discharged from the device body 16. In addition, two media supply containers 81a and 81b for accommodating media of different sizes are shown as media supply containers 81. However, the media supply containers 81 are not limited to these, and there may be three or more, or just one. Furthermore, a manual feeder (not shown) may be provided, and the media may be guided from the manual feeder to the transport path.

[0025] <First Fuser> The first fuser 40 of this embodiment includes, for example, a heating fuser roll 41 and a pressure fuser roll 42. Here, the heating fuser roll 41 is equipped with a heating source (not shown), such as a halogen lamp. The pressure fuser roll 42 is positioned opposite the heating fuser roll 41 and transports the medium by clamping it in the fixing area formed between the heating fuser roll 41 and the pressure fuser roll 42. Therefore, when the medium holding the unfixed toner image passes through the fixing area of ​​the first fuser 40, the unfixed toner image on the medium is fixed onto the medium by heat and pressure. In this example, the first fuser 40 is a roll-pair configuration with a heating and pressing method, but it is not limited to this and can be selected as appropriate. For example, one configuration is to hold the medium in a fixing area formed between a heating and fixing roll and a pressure fixing belt and heat and press fixing it. In this case, a pressure pad can be placed opposite the heating and fixing roll, and a pressure fixing belt can be interposed between the heating and fixing roll and the pressure pad. In this example, it is sufficient that the pressure fixing belt is rolled by the heating and fixing roll.

[0026] -Example configuration of post-processing device- In this embodiment, the post-processing device 50, as shown in Figure 2, is provided in the middle of the media transport path 51 and includes a second fuser 60 that makes the toner image surface of the media highly glossy, and a cutting device 70 that cuts the media that has passed through the second fuser 60. In this embodiment, a second discharge receiver 88 is provided downstream of the post-processing device 50 to receive the media that has passed through the cutting device 70. Before describing the second fuser 60 in detail, we will first explain the cutting device 70.

[0027] -Cutting machine- In this embodiment, the cutting device 70 is capable of cutting the edges of the medium, for example, to produce borderless prints. Therefore, as shown in Figure 2, the cutting device 70 includes a slitter 71 and circular cutters 72 (72a, 72b). Here, the slitter 71 is a component that cuts the medium in the width direction, and the circular cutters 72 are components that cut the medium in the feed direction length. Furthermore, the cutting device 70 is equipped with a plurality of transport rolls 73, 74 for transporting the medium. In this example, the slitter 71 has a number of blades corresponding to the required number of cuts in the axial direction and cuts the material in the feeding direction while conveying it. The circular cutter 72 cuts the material by temporarily stopping the conveyance of the material and moving the upper rolling cutter along the lower blade. Alternatively, the circular cutter 72 may be provided with, for example, a roller cutter in the axial direction and cut the material while conveying it.

[0028] Furthermore, the cutting device 70 not only has the function of cutting a medium into multiple sheets (for example, four sheets), but also other functions. Other functions include, for example, printing one L-size image on a postcard-sized medium (100 x 150 mm) to create a borderless print. Another function is to obtain any number of L-size images (for example, photographic images taken with a digital camera). In this case, one can combine printing four images on an A4-sized medium with printing one image each on any number of postcard-sized mediums. Moreover, by making the widthwise position of the blade of the slitter 71 variable, it becomes possible to cut to various sizes such as 4-cut, 6-cut, and 8-cut.

[0029] -Basic configuration of the second fuser- The second fuser 60 has a basic configuration similar to that of the fuser device 10 shown in Figure 1(a). In other words, as shown in Figures 2 and 3, the second fuser 60 comprises a heated fuser roll 61, a conveyor fuser belt 62, a pressurized fuser roll 63, and a cooler 64. Here, the heated fixing roll 61 corresponds to the heated fixing means (see Figure 1(a)), and in this example, it has a heating source 65 inside. The conveying fixing belt 62 also corresponds to the conveying fixing means (see Figure 1(a)), and is stretched over the heated fixing roll 61 so as to be circulating. The conveying fixing belt 62 conveys the medium S in contact with the image surface of the medium S. Furthermore, the pressurized fixing roll 63 corresponds to the pressurized fixing means (see Figure 1(a)). The pressurized fixing roll 63 is positioned opposite the heated fixing roll 61, with the conveying fixing belt 62 in between. The pressurized fixing roll 63 is pressed against the heated fixing roll 61 so as to form a fixing area FA between it and the heated fixing roll 61. Furthermore, the cooler 64 corresponds to a cooling means (see Figure 1(a)) and is installed within the conveyor fixing belt 62 to cool the conveyor fixing belt 62. In this example, the cooler 64 is installed on the conveyor fixing belt 62 downstream of the fixing area FA in the conveyor direction of the medium S, and is in contact with the back surface of the medium conveying area SA of the conveyor fixing belt 62.

[0030] <Heat fixing roll> The heated fixing roll 61 has a structure in which a release layer (not shown) made of PFA tubing or the like is formed around a metal core 61a with high thermal conductivity. A heating source 65, such as a halogen lamp, is provided inside the core 61a, and the heating source 65 is controlled to heat the surface of the heated fixing roll 61 to a predetermined temperature. The heated fixing roll 61 is also rotated by a drive motor 69 (see Figure 6) and rotates in a circulating manner on the conveyor fixing belt 62.

[0031] <Conveyor fixing belt> The conveyor fixing belt 62 consists of an endless film substrate 62a made of, for example, thermosetting polyimide resin, with a highly smooth coating layer 62b made of fluororubber or silicone rubber formed on its surface. The film substrate 62a and coating layer 62b of the conveyor fixing belt 62 are selected to have appropriate thicknesses in order to maintain mechanical strength and effectively utilize thermal energy. For example, a substrate of about 75 μm with a coating layer of about 35 μm is used. Furthermore, the conveying and fixing belt 62 is stretched over the heating and fixing roll 61 and the peeling roll 67, and is designed to circulate as the heating and fixing roll 61 rotates. Here, the peeling roll 67 corresponds to a peeling means (see Figure 1(a)) that peels the medium S from the conveyor fixing belt 62. This peeling roll 67 rotates in accordance with the movement of the conveyor fixing belt 62, and as the peeling roll 67 wraps around the conveyor fixing belt 62 and stretches it, the direction of movement of the conveyor fixing belt 62 is abruptly changed. As a result, the medium S on the conveyor fixing belt 62 is naturally peeled off from the conveyor fixing belt 62 at the position of the peeling roll 67 due to the rigidity of the medium S itself.

[0032] Furthermore, in this example, the conveyor fixing belt 62 is stretched over the heating fixing roll 61 and the peeling roll 67, but it is not limited to this configuration. For example, a steering roll (not shown) may be provided on the side of the conveyor fixing belt 62 that returns from the peeling roll 67 to the heating fixing roll 61. In this case, the steering roll maintains the tension of the conveyor fixing belt 62 by pressing it outward. The steering roll then corrects any misalignment that occurs when the conveyor fixing belt 62 moves in a circular motion by tilting its axial position. Here, "misalignment" refers to the phenomenon in which the conveyor fixing belt 62 moves toward one of the ends of the steering roll.

[0033] <Pressure fixing roll> On the other hand, the pressurized fixing roll 63 has a metal core 63a with high thermal conductivity, surrounded by an elastic layer 63b made of silicone rubber or the like. A release layer (not shown) similar to the release layer of the heated fixing roll 61 is formed on the surface of the elastic layer 63b. In this embodiment, a heating source 66, such as a halogen lamp, is also provided inside the core 63a of the pressurized fixing roll 63. This heating source 66 is controlled to heat the surface of the pressurized fixing roll 63 to a predetermined temperature. As a result, the medium S conveyed to the second fixing unit 60 passes through the fixing area FA between the heated fixing roll 61 and the pressurized fixing roll 63. At this time, the toner image on the medium S is heated and pressurized with the toner image surface in contact with the conveying fixing belt 62.

[0034] <Cooler> In this embodiment, the cooler 64 is provided in contact with the back surface of the conveying and fixing belt 62 between the heating and fixing roll 61 and the peeling roll 67 (corresponding to the media conveying region SA). The cooler 64 contacts a portion of the media conveying region SA of the conveying and fixing belt 62, and this contact region is designated as the cooling region CA. In other words, the cooler 64 cools the conveying and fixing belt 62 by absorbing heat from the conveying and fixing belt 62 in the cooling region CA. As a result, the media S that is conveyed in close contact with the conveying and fixing belt 62 is cooled. In this embodiment, the cooler 64 corresponds to a so-called heat sink and is composed of a fin member 64a and a cover member 64b. Here, the fin member 64a has a number of heat dissipation fins that extend in a direction substantially perpendicular to the surface along the conveyor fixing belt 62. The cover member 64b is formed in a rectangular cross-section cylindrical shape so as to cover the fin member 64a. This cooler 64 forcibly releases heat from the fin member 64a by circulating air inside with a blower (not shown). Furthermore, the cooler 64 is equipped with a temperature sensor 641 (see Figure 6) on a part of the fin member 64a, for example. Based on the detection result of the temperature sensor 641, the cooler 64 is configured to turn a blower (not shown) on or off, or to adjust the strength of the airflow.

[0035] <Close transportability of the medium> In this embodiment, the measures shown in Figure 3 have been taken to ensure the cooling effect of the cooler 64. Specifically, in this example, the medium S conveyed by the conveyor fixing belt 62 is positioned in close proximity to the cooling area CA of the cooler 64. In this example, an inlet-side opposing roll 111 is provided on the surface side of the conveyor fixing belt 62 at a location corresponding to the inlet (upstream starting point A) of the cooling area CA of the cooler 64. This inlet-side opposing roll 111 is positioned in contact with the conveyor fixing belt 62 and rotates in accordance with the conveyor fixing belt 62. Furthermore, an outlet-side opposing roll 112 is provided on the surface side of the conveyor fixing belt 62 at a location corresponding to the outlet (downstream endpoint B) of the cooling area CA of the cooler 64. This outlet-side opposing roll 112 is positioned in contact with the conveyor fixing belt 62 and rotates in accordance with the conveyor fixing belt 62.

[0036] Thus, both the inlet-side opposing roll 111 and the outlet-side opposing roll 112 function as opposing rotation means. In this example, the inlet-side opposing roll 111 must be positioned at a location corresponding to the entrance of the cooling area CA. As a result, the medium S conveyed by the conveyor fixing belt 62 is drawn in by the inlet-side opposing roll 111 at the entrance of the cooling area CA so as to be in close contact with the conveyor fixing belt 62. On the other hand, the outlet-side opposing roll 112, together with the inlet-side opposing roll 111, is effective in bringing the medium S into close contact with the conveying and fixing belt 62 at two locations, front and rear, in the conveying direction of the medium S. However, although the outlet-side opposing roll 112 is provided at a location corresponding to the outlet of the cooling area CA, it is not limited to this, and may be provided upstream of the outlet of the cooling area CA.

[0037] <Selection of media> Typically, to obtain high-gloss images such as photographic images, it is preferable to use a special paper as the medium S, as shown in Figure 4(a). The special paper has a base layer L1 with moisture-proof layers L2 on both sides, and an image-receiving layer L3 on the recording surface (toner image-forming surface). This is similar in structure to photographic paper used in silver halide photography, for example. The moisture-proof layer L2 is made of an airtight resin such as polyethylene, and a thickness of a few μm is sufficient to provide the moisture-proof effect of the base layer L1. The image-receiving layer L3 is mainly composed of a thermoplastic resin such as polyester with a melting point of approximately 130°C, and is made with a layer thickness of 5 to 20 μm, preferably about 10 μm. On the other hand, the base layer L1 is made of a composition similar to ordinary paper, mainly composed of cellulose, but it is also possible to use a dedicated base layer L1 with a different composition.

[0038] Therefore, when selecting a medium S, one possible configuration is one in which a moisture-proof layer L2 is provided on both sides of the base layer L1, and an image-receiving layer L3 similar to that of toner material is provided. By using such a medium S, the following advantages can be obtained. (1) By eliminating air permeability, it is possible to prevent problems that occur when the substrate layer L1 absorbs moisture in a high-humidity environment. Examples of such problems include the substrate layer L1 stretching and curling, or the toner image being stretched and cracking. (2) The toner image can be well embedded in the image receiving layer L3, and a smooth print surface can be obtained. This is because the presence of the image receiving layer L3 melts the toner image together with the image receiving layer L3, and by applying pressure, it becomes possible to embed the toner image into the image receiving layer L3.

[0039] When using this special paper in photo print mode, fixing is performed by the second fuser 60, and as shown in Figure 4(b), the toner image is embedded in the image receiving layer L3. At this time, the surface properties of the transport fixing belt 62 of the second fuser 60 are transferred, and the surface of the image receiving layer L3 and the toner image surface become nearly uniform, resulting in a glossy image. On the other hand, Figure 4(c) shows the state in plain paper print mode where the toner image is fixed on plain paper as the medium S by the first fuser 40 only. In this case, the toner image is placed on the substrate layer L1, and the image surface is poorly glossy because the toner image protrudes.

[0040] -Characteristic configuration of the second fuser- In this example, the second fuser 60 is equipped with a heat transfer device 100 within the conveyor fixing belt 62, as shown in Figure 3. This heat transfer device 100 transfers some of the heat from the high-temperature section of the conveyor fixing belt 62 to the low-temperature section. Here, the "high-temperature section" refers to the part of the conveyor fixing belt 62 from the fixing area FA downstream in the direction of movement to the cooling area CA. The "low-temperature section" refers to the part of the conveyor fixing belt 62 from the peeling roll 67 downstream in the direction of movement to the heating area by the heating fixing roll 61.

[0041] <Necessity of heat transfer devices> Here, assuming an embodiment without a heat transfer device 100, the following fixing operation is performed. The second fuser 60 heats the transport fixing belt 62 with a heating fixing roll 61 and heats and pressurizes the toner image in the fixing area FA to fix it. Then, in order to obtain a high-gloss image, the second fuser 60 cools the medium S via the transport fixing belt 62 in the cooler 64 to a predetermined temperature. In this manner, as the conveyor fixing belt 62 circulates between the heated fixing roll 61 and the peeling roll 67, heating and cooling (heat dissipation) are repeatedly performed. At this time, the cooling capacity of the cooler 64 is predetermined depending on the temperature of the conveyor fixing belt 62 just before it enters the cooling region CA. Furthermore, the heating power for the heated fixing roll 61 is determined depending on the temperature of the conveyor fixing belt 62 just before it enters the heating region after being cooled by the cooler 64.

[0042] In such a heating and cooling cycle, the heat corresponding to the decrease in temperature of the conveyor fixing belt 62 during cooling is simply wasted. Furthermore, the power required to heat the heating and fixing roll 61 is necessary to raise the temperature of the conveyor fixing belt 62, which has decreased in temperature in the cooler 64, to a temperature at which it can be fixed. Therefore, in an embodiment without a heat transfer device 100, it becomes difficult to miniaturize the cooler 64 from the standpoint of ensuring sufficient cooling capacity by the cooler 64. Also, regarding the power required to heat the heating and fixing roll 61, it becomes difficult to reduce the heating power from the standpoint of ensuring sufficient heat to heat the conveyor fixing belt 62. This example aims to reduce the cooling capacity of the cooler 64 and the heating power supplied to the heating and fixing roll 61 for the second fuser 60.

[0043] <Location of heat transfer equipment installation> In this example, the heat transfer device 100 is installed in the internal space on the back surface of the conveyor fixing belt 62, as shown in Figure 3(a). At this time, the heat transfer device 100 only needs to be installed in a non-contact state between the cooler 64 and the heating fixing roll 61. The heat transfer device 100 in this example transfers a portion of the heat from the conveyor fixing belt 62 from the first position P1 to the second position P2. Here, the first position P1 is selected in the high-temperature region of the conveyor fixing belt 62 after heating by the heating fixing roll 61 and before cooling by the cooler 64. The second position P2 is selected in the low-temperature region of the conveyor fixing belt 62 downstream of the peeling roll 67 in the direction of movement, up to the heating region of the heating fixing roll 61. As a location for selecting the second position P2, even after cooling by the cooler 64, the media conveying region SA or the tensioned region of the peeling roll 67 is undesirable. This is because even if the conveyor fixing belt 62 and the media S are cooled by the cooler 64, there is a concern that the media S will be reheated before or during peeling. In particular, in this example, the heat transfer device 100 is positioned closer to the cooler 64 than the heating and fixing roll 61.

[0044] <Example of heat transfer appliance configuration> In this example, the heat transfer device 100 includes a first contact member 101, a second contact member 102, and a heat transfer component 103. Here, the first contact member 101 is positioned in contact with a first position P1 on the back surface of the conveyor fixing belt 62. The first contact member 101 is made of a metal plate made of a heat-conducting material such as aluminum and extends along a direction that intersects the direction of movement of the conveyor fixing belt 62. Furthermore, the second contact member 102 is positioned in contact with a second position P2 on the back surface of the conveyor fixing belt 62. The second contact member 102 is made of a metal plate made of a heat-conducting material such as aluminum and extends along a direction that intersects the direction of movement of the conveyor fixing belt 62. Furthermore, the heat transfer component 103 is joined between the first contact member 101 and the second contact member 102. In this example, multiple heat transfer components 103 are provided in intersecting directions that intersect the conveying direction of the medium S.

[0045] As the heat transfer component 103, a heat pipe 104 as shown in Figures 5(c) and 5(d) is used. The heat pipe 104 has a hollow (for example, cylindrical) pipe body 105 made of copper or aluminum with good thermal conductivity. Both ends of this pipe body 105 are sealed, and a highly volatile working fluid 106 is sealed inside the pipe body 105. A wick 107 is provided on the inner wall of the pipe body 105, leaving a cavity 108 inside. This wick 107 is made up of bundled core materials with a capillary structure and is a functional component that moves the condensed working fluid 106 using capillary action.

[0046] In this example, when a temperature difference is applied to both ends of the heat pipe 104, the following processes (1) to (4) occur. Note that in Figure 5(d), the temperature T of the high-temperature part is set to T. H The temperature T of the low-temperature part is T L Let's assume that. (1) The working fluid 106 absorbs heat and evaporates at the inner wall of the high-temperature part of the heat pipe 104. (2) The vapor of the working fluid 106 moves to the low-temperature section through the cavity 108. (3) The vapor of the working fluid 106, which has been cooled in the low-temperature section, condenses back into a liquid and is absorbed by the wick 107 on the inner wall. (4) The working fluid 106 returns to the high-temperature section via the wick 107 by capillary action. In this way, the working fluid 106 circulates within the heat pipe 104, and heat transfer occurs from the high-temperature area to the low-temperature area.

[0047] In this embodiment, as shown in Figure 5(e), the first position P1 of the conveyor fixing belt 62 is a high-temperature area, and the second position P2 is a low-temperature area. In this case, the heat transfer device 100 has a first contact member 101 in contact with the first position P1, which is a high-temperature area, and a second contact member 102 in contact with the second position P2, which is a low-temperature area. In this state, the first contact member 101 absorbs a portion of the heat Qin of the conveyor fixing belt 62, which is a high-temperature area. As a result, the first contact member 101 becomes high-temperature, and a temperature difference is created in which the second contact member 102 becomes lower in temperature compared to the first contact member 101. The heat Qin absorbed by the first contact member 101 is transferred to the second contact member 102, which is in a low-temperature state, by the heat conduction action of the heat pipe 104, which is a heat transfer component. As a result, the transferred heat Qout is released to the low-temperature portion (second position P2) of the conveyor fixing belt 62 that is in contact with the second contact member 102. Through this heat transfer process, at the first position P1 of the conveyor fixing belt 62, heat Qin is absorbed by the heat transfer device 100, and the conveyor fixing belt 62 is cooled accordingly. Meanwhile, at the second position P2 of the conveyor fixing belt 62, heat Qout is transferred from the heat transfer device 100 to the conveyor fixing belt 62, and the conveyor fixing belt 62 is heated accordingly. Here, the degree of cooling or heating of the conveying and fixing belt 62 by the heat transfer device 100 depends on the thermal conductivity of the heat transfer device 100. For example, in order to reduce the temperature of the conveying and fixing belt 62 by 5°C or more at the first position P1, it is sufficient to provide the heat transfer device 100 with a thermal conductivity that can achieve this.

[0048] <Peripheral structure of the second fuser> In this example, as shown in Figure 6, an inlet guide member 52 is provided near the inlet of the second fuser 60 to guide the medium S to the inlet of the second fuser 60. Furthermore, a position sensor 53 is provided to detect the position of the leading or trailing end of the medium S as it passes through the transport path 51. Furthermore, an outlet guide member 54 is provided near the outlet of the second fuser 60 to guide the medium S discharged from the outlet of the second fuser 60. A conveyor roll 55 is provided downstream of this outlet guide member 54. Furthermore, in this example, in order to obtain a high-gloss image, the peeling temperature Ts of the medium S at the peeling position of the second fuser 60 is adjusted to be below a predetermined threshold temperature. For this reason, a temperature sensor 56 is provided near the peeling position of the second fuser 60 to measure the peeling temperature Ts of the medium S at the peeling position in a non-contact manner. A radiation thermometer is used as the temperature sensor 56.

[0049] -Control system for the second fuser- In this example, the control system of the second fuser 60 has a control device 150 composed of a microcomputer including various processors, as shown in Figure 6. Here, "processor" refers to a processor in a broad sense, and includes general-purpose processors (e.g., CPU: Central Processing Unit, etc.) and dedicated processors (e.g., GPU: Graphics Processing Unit, ASIC: Application Specific Integrated Circuit, FPGA: Field Programmable Gate Array, programmable logic device, etc.). Furthermore, the control device 150 is connected to the operation panel 151 of the image forming system 15. The operation panel 151 is equipped with a start switch to initiate the image formation process on the medium S, a mode switch to specify the image formation mode such as single-sided printing, double-sided printing, or high-resolution printing, and a medium type indicator to indicate the type of medium to be used. Furthermore, the ROM, which serves as the memory device of the control device 150, has programs related to the fixing process of the second fuser 60 (heating and pressurizing process in the fixing area FA, cooling process by the cooler 64, etc.) pre-installed. In addition, various detectors such as a position sensor 53 and temperature sensors 56, 641 are connected to the control device 150. Furthermore, various control targets (drive motor 69, heating sources 65, 66, etc.) are connected to the control device 150. The processor of the control device 150 receives instruction signals from the operation panel 151 and detection signals from various detectors, executes the aforementioned program, and sends appropriate control signals to each controlled object.

[0050] -Basic operation of the image forming system- Next, the basic operation of this image forming system 15 will be described. As shown in Figure 2, each toner image produced by each image forming unit 20 (20a to 20d) is first transferred onto the intermediate transfer body 30 and transported to the secondary transfer area. Meanwhile, the multiple toner images held on the intermediate transfer body 30 are secondarily (all at once) transferred to the medium S delivered from the medium supply container 81 by the secondary transfer unit 33. The unfixed toner image transferred to the medium S is then fixed by the first fuser 40. After that, the medium S holding the fixed toner image is guided by the switching member 86 to the second discharge receiver 88 via the first discharge receiver 87 or the post-processing device 50.

[0051] In this embodiment, the switching direction of media transport by the switching member 86 is performed as follows: it differs between the plain paper print mode (low gloss print) which forms a normal image and the photo print mode (high gloss print) which forms a high gloss image such as a photograph. In plain paper printing mode, the media S, after being fixed in the first fuser 40, is discharged to the first discharge tray 87 by the switching member 86. On the other hand, in photo printing mode, the media S, after being fixed in the first fuser 40, is transported to the second fuser 60 by the switching member 86. After that, the media S is further fixed by the second fuser 60 and then discharged to the second discharge tray 88 via the cutting device 70. In particular, the cutting device 70 should be used when borderless prints such as photographic images are preferred. If cutting is not necessary, the media should be discharged to the second discharge tray 88 without cutting.

[0052] Generally, to obtain high-gloss images such as photographs, it is preferable to use a special paper as the medium S, as shown in Figure 4(a). When using this special paper in photo print mode, fixing is performed by the second fuser 60, and as shown in Figure 4(b), the toner image is embedded in the image receiving layer L3. At this time, the surface properties of the transport fixing belt 62 of the second fuser 60 are transferred, and the surface of the image receiving layer L3 and the toner image surface become nearly uniform, resulting in a glossy image.

[0053] - Fixing action by the second fuser - The fixing process by the second fixing unit 60 is carried out as follows. As shown in Figure 3, the medium S, which has been guided to the post-processing device 50 via the first fuser 40, is about to enter the second fuser 60. In this state, in the second fuser 60, the heating fuser roll 61 and the pressure fuser roll 63 are heated to a temperature at which they can be fixed by the heating sources 65 and 66, respectively. Also, the conveyor fuser belt 62 is in a state of circulating rotation in accordance with the driving rotation of the heating fuser roll 61. Furthermore, the cooler 64 is in a standby state, ready to perform cooling operations by driving the air blower. In this state, the medium S is heated and pressure-fixed in the fixing area FA of the second fuser 60, and then transported by the conveyor fixing belt 62. After the heated medium S is cooled by the cooler 64, it is peeled off at the peeling position of the second fuser 60. Therefore, the second fuser 60 performs a series of fixing processes, including heating and pressurizing followed by cooling. As a result, by using the special paper shown in Figure 4 as the medium S, it is possible to obtain high-gloss images similar to photographic images.

[0054] -Effects of heat transfer devices- <Heat dissipation from the conveyor belt> In this example, before the cooling process by the cooler 64 is carried out, the heat transfer process by the heat transfer device 100 is carried out on the conveyance and fixing belt 62. As shown in FIG. 7, the heat transfer device 100 absorbs heat Qin at the first position P1 of the conveyance and fixing belt 62 and moves it to the second position P2 side. At this time, when the conveyance and fixing belt 62 passes through the first position P1, heat Qin is taken away by the heat transfer device 100. Therefore, if the temperatures before and after the first position P1 of the conveyance and fixing belt 62 are T1 and T2, the relationship T2 < T1 is satisfied. In such a situation, the conveyance and fixing belt 62 enters the cooling area CA by the cooler 64 in a state where the temperature has decreased by the temperature difference ΔT (T1 - T2). Also, the cooling capacity of the cooler 64 needs to release the amount of heat necessary to lower the temperature of the medium S that has passed through the cooling area CA to the target temperature.

[0055] Here, the cooler 64 of this example is compared with the cooler 64' of the second fixing device 60' according to the comparative form 1 shown in FIG. 8(c) in terms of cooling capacity. As shown in FIG. 8(b), the cooler 64 of this example needs to have the cooling capacity to lower the medium S on the conveyance and fixing belt 62 at temperature T2 to a predetermined temperature. On the other hand, the cooler 64' according to the comparative form 1 needs to have the cooling capacity to lower the medium S on the conveyance and fixing belt 62 at temperature T1 (T1 > T2) to a predetermined temperature. The cooling capacities of the coolers 64 and 64' are selected so that the peeling temperature Ts of the medium S at the peeling position is below a predetermined threshold temperature Tth in order to obtain a high-gloss image. Therefore, the cooling capacity of the cooler 64 of this example can be less than that of the cooler 64' according to the comparative form 1. In this example, the cooling capacity of the cooler 64 depends on the contact area between the conveyance and fixing belt 62 and the cooler 64, or the air volume of the blower.

[0056] First, the contact area between the conveyance and fixing belt 62 and the cooler 64 is considered. Now, for the cooler 64' according to the comparative form 1 and the cooler 64 of this example, let the contact lengths with the conveyance and fixing belt 62 along the moving direction of the conveyance and fixing belt 62 be D0 and D1. At this time, the contact area of the cooler 64 of this example with respect to the conveyance and fixing belt 62 can be smaller than that of the cooler 64' according to Comparative Form 1. Therefore, the relationship D0 > D1 is satisfied. As a result, in this example, it is possible to make the contact length D1 of the cooler 64 shorter than the contact length D0 of the cooler 64' according to Comparative Form 1. Thus, in this example, it becomes possible to miniaturize the cooler 64 along the moving direction of the conveyance and fixing belt 62. As a result, the length of the medium conveyance area SA of the conveyance and fixing belt 62 can be designed to be shorter, and accordingly, the second fixing device 60 itself can be miniaturized. Details of this point will be described in detail in the examples. Also, considering the air volume of a blower (not shown), it is possible to reduce the air volume of the cooler 64 of this example compared to the cooler 64' according to Comparative Form 1. Therefore, the cooler 64 of this example can suppress the drive power of the blower to a smaller amount.

[0057] <Heat absorption action on the conveyance and fixing belt> Also, as shown in FIG. 7, the heat transfer device 100 transfers the heat Qin absorbed from the conveyance and fixing belt 62 and releases it as heat Qout to the conveyance and fixing belt 62 at the second position P2. At this time, when the conveyance and fixing belt 62 passes through the second position P2, the heat Qout is given from the heat transfer device 100. Therefore, if the temperatures before and after the first position P1 of the conveyance and fixing belt 62 are T3 and T 4, the relationship T3 < T4 is satisfied. In such a situation, the conveyance and fixing belt 62 enters the heating area of the heating and fixing roll 61 in a state where the temperature has risen by the temperature difference ΔT (T4 - T3). Also, in the heating and fixing roll 61, heating power is supplied to the heating source 65 so as to raise the temperature condition of the fixing area FA to a temperature at which fixing is possible. In this example, heating power is also supplied to the heating source 66 of the pressure fixing roll 63. Here, the heating and fixing roll 61 in this example requires the heating power necessary to raise the temperature of the conveyance and fixing belt 62 at temperature T4 to a temperature at which fixing is possible. On the other hand, a heating and fixing roll (not shown) according to Comparative Form 1 requires the heating power necessary to raise the temperature of the conveyance and fixing belt 62 at temperature T3 (T3 < T4) to a temperature at which fixing is possible. Therefore, in this example, the heating power required for the heating and fixing roll 61 can be less than the heating power required for the heating and fixing roll (not shown) according to Comparative Form 1.

[0058] <Device layout ideas for heat transfer devices> In this example, the heat transfer device 100 is disposed closer to the cooler 64 than the heating and fixing roll 61 within the conveyance and fixing belt 62. For this reason, the heat transfer device 100 is less likely to be affected by the heat from the heating and fixing roll 61 than when it is disposed closer to the heating and fixing roll 61. If the heat transfer device 100 is disposed closer to the heating and fixing roll 61, the vicinity of the approximate center in the length direction of the heat transfer device 100 approaches the heating and fixing roll 61 and is likely to be heated. For this reason, there is a concern that the vicinity of the center in the length direction of the heat pipe 104 as the heat transfer component 103 is partially heated, and the mobility of the internal working fluid is impaired. In this example, the heat transfer from the heating and fixing roll 61 is mainly radiation, and electromagnetic waves are emitted radially. For this reason, it is presumed that the amount of radiant heat acting on the heat pipe 104 decreases when the distance between the heating and fixing roll 61 and the heat pipe 104 is separated to some extent.

[0059] ◎ Embodiment 2 FIG. 9(a) shows a main part of the second fixing device according to Embodiment 2. In the figure, the basic configuration of the second fixing device 60 is substantially the same as that of Embodiment 1. However, unlike Embodiment 1, the second fixing device 60 includes a holding member 120 that holds the contact state between the heat transfer device 100 and the conveyance and fixing belt 62. Note that the same reference numerals as those in Embodiment 1 are given to the same components as in Embodiment 1, and the detailed description thereof is omitted here. In this example, the second fuser 60 has the first position P1 of the conveyor fixing belt 62 positioned above the second position P2. The upper belt portion 621 of the conveyor fixing belt 62, located in the media conveying area SA, is positioned to be in contact with the cooler 64 midway along its length. Therefore, in the upper belt portion 621, the position of the surface of the conveyor fixing belt 62 is determined between the heating fixing roll 61 and the cooler 64. Thus, the conveyor fixing belt 62 maintains a stable contact state with the first contact member 101 of the heat transfer device 100 at the first position P1. In contrast, the lower belt portion 622 of the conveyor fixing belt 62, which is located in the return direction, does not have a supporting member in the middle. Therefore, in the lower belt portion 622 of the conveyor fixing belt 62, as shown in Figure 9(b), the distance from the peeling roll 67 to the heat transfer device 100 is long. Consequently, the conveyor fixing belt 62 flaps at the second position P2, and the contact state with the second contact member 102 of the heat transfer device 100 tends to become unstable.

[0060] Therefore, in this example, as shown in Figure 9(a), the aforementioned holding member 120 is provided below the lower belt portion 622 of the conveying and fixing belt 62. This holding member 120 is positioned in contact with the lower belt portion 622 of the conveying and fixing belt 62 on the upstream side in the direction of movement from the second position P2. In this example, the holding member 120 is equipped with a holding roll 121 that rotates in accordance with the conveying and fixing belt 62. This holding roll 121 functions as a positioning roll that positions the lower belt portion 622 from below. As a result, the surface of the conveying and fixing belt 62 is determined between the heating and fixing roll 61 and the holding roll 121. Therefore, the conveying and fixing belt 62 maintains a stable contact with the second contact member 102 of the heat transfer device 100 at the second position P2.

[0061] Furthermore, in this example, an inlet-side opposing roll 111 is positioned on the upper belt portion 621 of the conveyor fixing belt 62, facing the inlet of the cooling area CA provided by the cooler 64. This inlet-side opposing roll 111 rotates in accordance with the conveyor fixing belt 62, guiding the medium S into the cooling area CA. At this time, the inlet-side opposing roll 111 also functions as a positioning roll that positions the upper belt portion 621 of the conveyor fixing belt 62 from above. As a result, the upper belt portion 621 of the conveyor fixing belt 62 is prevented from lifting up during movement. Thus, the inlet-side opposing roll 111 also serves as a holding member 120 that maintains the contact state of the conveyor fixing belt 62 with the first contact member 101 of the heat transfer device 100 at the first position P1.

[0062] ◎Transformation Form 2-1 Figure 10 shows the main parts of the second fuser according to the modified form 2-1. In the figure, the basic configuration of the second fuser 60 is substantially the same as that of Embodiment 2, but unlike Embodiment 2, it is positioned upside down. In this example, the second fuser 60, like in Embodiment 2, has a transport fuser belt 62 stretched between the heating fuser roll 61 and the peeling roll 67. However, unlike in Embodiment 2, the transport fuser belt 62 rotates in a clockwise direction. In this example, the lower belt portion 622 of the transport fuser belt 62 functions as a media transport area SA. Therefore, in this example, the cooler 64 is positioned in contact with the middle of the lower belt portion 622 of the conveyor fixing belt 62.

[0063] Furthermore, in this example, the first position P1 (high temperature section) of the conveyor fixing belt 62 is positioned below the second position P2 (low temperature section). Therefore, in this example, the heat transfer device 100 is positioned so that the high temperature section of the heat pipe 104, which is a heat transfer component 103, is on the vertically downward side. Positioning the heat pipe 104 in this way is preferable from the viewpoint of facilitating the movement of the working fluid within the heat pipe 104. Furthermore, in this example, an inlet-side opposing roll 111 is provided on the surface side of the conveyor fixing belt 62 at a location corresponding to the inlet of the cooling area CA of the cooler 64. In addition, an outlet-side opposing roll 112 is provided on the surface side of the conveyor fixing belt 62 at a location corresponding to the outlet of the cooling area CA of the cooler 64.

[0064] In this example, the inlet-side opposing roll 111 also serves as a holding member 120 that maintains the contact state between the conveyor fixing belt 62 and the first contact member 101 of the heat transfer device 100. Specifically, the inlet-side opposing roll 111 is positioned to contact the lower belt portion 622 of the conveyor fixing belt 62 downstream of the first position P1 in the direction of movement. Therefore, the inlet-side opposing roll 111 functions as a positioning roll that positions the lower belt portion 622 from below. As a result, the surface of the conveyor fixing belt 62 is determined between the heating fixing roll 61 and the inlet-side opposing roll 111. Thus, the conveyor fixing belt 62 maintains a stable contact state with the first contact member 101 of the heat transfer device 100 at the first position P1.

[0065] On the other hand, the upper belt portion 621 of the conveyor fixing belt 62 does not have a supporting member in the middle. Therefore, the distance from the peeling roll 67 to the heat transfer device 100 is long in the upper belt portion 621 of the conveyor fixing belt 62. Consequently, the conveyor fixing belt 62 flaps at the second position P2, and the contact state with the second contact member 102 of the heat transfer device 100 tends to become unstable. Therefore, in this example, as shown in Figure 10, a holding member 120 is provided above the upper belt portion 621 of the conveying and fixing belt 62. This holding member 120 is positioned in contact with the upper belt portion 621 of the conveying and fixing belt 62 upstream of the second position P2 in the direction of movement. In this example, the holding member 120 is equipped with a holding roll 121 that rotates in accordance with the conveying and fixing belt 62. This holding roll 121 functions as a positioning roll that positions the upper belt portion 621 from above. As a result, the surface of the conveying and fixing belt 62 is determined between the heating and fixing roll 61 and the holding roll 121. Therefore, the conveying and fixing belt 62 maintains a stable contact with the second contact member 102 of the heat transfer device 100 at the second position P2. [Examples]

[0066] ◎Example 1 Example 1 embodies the second fuser according to Embodiment 1 and verifies the relationship between the media peeling temperature and the media glossiness. In Example 1, the fixing conditions using the second fuser are as follows: • Medium: Special paper for photographic images (see Figure 4) • Toner used: Yellow, magenta, cyan, and black toner cartridges (4 colors total) Fixing temperature: 140℃ • Conveying speed of the media on the conveyor belt: 50 mm / s • Heat transfer devices: heat pipes • Variable cooling capacity of the cooler • Temperature measurement: Use an infrared thermometer as the temperature sensor. In Example 1, the fixing conditions in the fixing zone FA were kept constant, and the peeling temperature conditions of the medium were changed by changing the cooling capacity (airflow) of the cooler.

[0067] Figure 11 is a graph showing the relationship between the peeling temperature of the media and the glossiness of the media image. In the figure, the horizontal axis represents the peeling temperature Ts (°C) at the peeling position of the media in the second fuser. The vertical axis, "k100Gloss(20)", represents the specular gloss of a patch image of 100% black toner (K ​​toner) measured at a 20° tilt. According to the figure, for example, if the goal is to achieve a glossiness of 80% or higher in the media image (to obtain a high-gloss image), it is understood that the fixing conditions should be adjusted so that the media peeling temperature Ts is below the desired threshold temperature Tth (e.g., 70°C). Since the heat transfer device 100 is used in Example 1, the following advantages can be obtained compared to the embodiment without the heat transfer device 100. Firstly, in order to achieve the desired peeling temperature Ts of the medium, it is possible to reduce the cooling capacity of the cooler 64 as heat is transferred by the heat transfer device 100. Secondly, when heating the heating and fixing roll 61, the heat transfer device 100 can preheat the conveying and fixing belt 62, thereby reducing the power required to heat the heating and fixing roll.

[0068] ◎Example 2 Example 2 embodies the second fuser according to Embodiment 1 and verifies the improvement effect of using a heat transfer device. In Example 1, as shown in Figure 8(b), the temperatures T1 and T2 before and after the heat transfer device 100 of the conveyor fixing belt 62 were measured, and the results shown in Figure 12(a) were obtained. In Figure 12(a), the horizontal axis T1 (before heat transfer) represents the temperature of the conveyor and fixing belt before it passes through the heat transfer device, and T2 (after heat transfer) represents the temperature of the conveyor and fixing belt after it passes through the heat transfer device. The vertical axis, belt temperature, represents the temperature of the conveyor and fixing belt. As shown in Figure 12(a), the heat transfer device (HP) was confirmed to reduce the temperature of the conveyor fixing belt from 109°C to 104°C, a reduction of 5°C. However, the effect of reducing the temperature of the medium itself was not very significant. Next, we will examine the case where the desired peeling temperature of the medium is obtained in a comparative example without a heat transfer device, and the case where the desired peeling temperature of the medium is obtained using Example 2. Figure 12(b) shows the verification results.

[0069] In the figure, for the horizontal axis, "HS(D0) / HP None" indicates the mode (Case 1) where the length in the medium conveyance direction of the cooling area CA of the cooler (HS) in the comparative example is D0. Also, "HS(D0) / HP With" indicates the mode (Case 2) where the length in the medium conveyance direction of the cooling area CA of the cooler (HS) in Example 2 is D0. "HS(D1) / HP With" indicates the mode (Case 3) where the length in the medium conveyance direction of the cooling area CA of the cooler (HS) in Example 2 is D1 (D1 < D0). Further, the vertical axis is the peeling temperature Ts of the medium. According to Example 1, it is understood that when obtaining a high-gloss image, the peeling temperature Ts of the medium may be selected to be below a desired threshold temperature Tth (for example, 70°C). Therefore, in the comparative example (Case 1), fixing conditions were selected such that the peeling temperature Ts of the medium was, for example, 58.5°C. In contrast, in Example 2 (Case 2), the peeling temperature Ts of the medium was 56.8°C. At this time, D0 = 39 mm. Also, in Example 2 (Case 3), the length D1 of the cooler was adjusted so that the peeling temperature Ts of the medium would be substantially the same as in Case 1. When the peeling temperature Ts of the medium was 58.4°C, D1 = 36 mm. Thus, it is understood that in an aspect provided with a heat transfer device, it is possible to reduce the cooling capacity of the cooler compared to an aspect not provided with a heat transfer device. For example, it was found that the length in the medium conveyance direction of the cooler can be reduced by about 8% from D0 to D1. Thereby, it becomes possible to realize miniaturization of the second fixing device along with miniaturization of the cooler. Of course, instead of miniaturizing the cooler, the air volume of the cooler may be suppressed to reduce the cooling capacity of the cooler.

[0070] (Appendix) (((1))) Rotatable heating and fixing means having a heat source, A belt-shaped transport and fixing means is stretched over the heating and fixing means and provided to be circulating, and transports the medium in contact with the image surface of the medium on which the unfixed image is held, A rotatable pressurizing fixing means is positioned opposite the heating fixing means with the transport fixing means in between, and pressurizes to form a fixing area for fixing the unfixed image between itself and the heating fixing means, A cooling means is provided in contact with the back surface of the conveying and fixing means, located downstream of the fixing area in the conveying direction of the medium within the conveying area of ​​the conveying and fixing means, for cooling the conveying and fixing means. A heat transfer means is provided in a non-contact state between the cooling means and the heating means in the internal space on the back surface of the conveying and fixing means, and is in contact with a first position located in the region of the conveying and fixing means before heating and before cooling, and a second position located in the region of the conveying and fixing means before cooling and before heating, and transfers a portion of the heat of the conveying and fixing means from the first position to the second position, A fixing device characterized by being equipped with the following features. (((2))) In the fixing device described in (((1))), The fixing device is characterized by comprising a heat transfer component that transfers heat from a high-temperature part to a low-temperature part. (((3))) In the fixing device described in (((2))), The fixing device is characterized in that the heat transfer means comprises: a first contact member made of a heat conductive material that is positioned in contact with the first position on the back surface of the conveying and fixing means and extends along an intersecting direction that intersects the direction of movement of the conveying and fixing means; a second contact member made of a heat conductive material that is positioned in contact with the second position on the back surface of the conveying and fixing means and extends along an intersecting direction that intersects the direction of movement of the conveying and fixing means; and a heat transfer component that is joined between the first contact member and the second contact member. (((4))) In the fixing device described in (((2))) or (((3))), The fixing device is characterized in that a plurality of heat transfer components are provided at intervals in a direction intersecting the conveying direction of the medium. (((5))) In a fixing device described in any of (((2))) to (((4))), The fixing device is characterized in that the heat transfer component is a heat pipe. (((6))) In a fixing device described in any of (((1))) to (((5))), The fixing apparatus is characterized in that the heat transfer means is positioned closer to the cooling means than to the heating fixing means. (((7))) In a fixing device described in any of (((1))) to (((6))), A fixing device characterized by being provided with a holding means for maintaining the contact state between the heat transfer means and the conveying and fixing means. (((8))) In the fixing device described in (((7))), The fixing device is characterized in that the holding means is provided upstream of the second position of the conveying and fixing means in the direction of movement of the conveying and fixing means, and is a positioning means that positions the conveying and fixing means such that the heat transfer means maintains contact with the second position. (((9))) In the fixing device described in (((7))), The conveying and fixing means is positioned opposite the entrance to the cooling area provided by the cooling means, and the opposing rotating means rotates in accordance with the conveying and fixing means, The fixing device is characterized in that the holding means also serves as the opposing rotating means, and the heat transfer means maintains contact with the first position. (((10))) In a fixing device described in any of (((1))) to (((9))), The fixing device is characterized in that the heat transfer means has a thermal conductivity that reduces the temperature of the conveying and fixing means that enters the cooling region by the cooling means by 5°C or more at the first position. (((11))) In the fixing device described in (((10))), The heat transfer means is characterized by having a thermal conductivity such that, taking into account the amount of heat generated by the heating and fixing means and the amount of heat dissipated by the cooling means, the temperature at the point where the medium is peeled from the transport and fixing means is below the threshold temperature necessary to obtain a high-gloss fixed image. (((12))) A means for creating an unfixed image on a medium, A fixing device according to any one of (((1))) to (((11))) for fixing an unfixed image held on the medium, An image forming system characterized by comprising the following features.

[0071] According to the fixing device described in (((1))), when fixing an unfixed image on a medium by heating and cooling a belt-shaped transport fixing means, a portion of the heat dissipated to cool the transport fixing means can be reused for heating, thereby reducing the amount of heat required for heating and cooling itself. According to the fixing device described in (((2))), a heat transfer means can be easily constructed by utilizing heat transfer components. According to the fixing device described in (((3))), a portion of the heat from the transport fixing means can be circulated substantially evenly across the entire area in the intersecting direction that intersects the direction of movement of the transport fixing means. According to the fixing device described in (((4))), compared to the case where a single heat transfer component is used, a portion of the heat of the transport fixing means can be efficiently circulated by distributing it over the entire area in the intersecting direction that intersects the direction of movement of the transport fixing means. According to the fixing device described in (((5))), a heat transfer means can be easily constructed by utilizing existing heat pipes as heat transfer components. According to the fixing device described in (((6))), the influence of heat from the heating fixing means on the heat transfer means can be suppressed compared to the configuration in which the heat transfer means is arranged closer to the heating fixing means. According to the fixing device described in (((7))), the heat transfer action by the heat transfer means can be stabilized compared to the configuration in which a holding means is not provided. According to the fixing device described in (((8))), even if the transport fixing means vibrates or bends under its own weight while moving, the contact state between the heat transfer means and the second position of the transport fixing means can be stabilized. According to the fixing device described in (((9))), by using the opposing rotating means in conjunction with the fixing device, the contact state between the heat transfer means and the first position of the transport fixing means can be stabilized. According to the fixing device described in (((10))), the performance of the heat transfer means can be easily selected based on the degree of temperature reduction at the first position of the transport fixing means. According to the fixing apparatus described in (((11))), the performance of the heat transfer means can be easily selected based on the temperature at the point where the medium is peeled from the transport fixing means in order to obtain a high-gloss fixed image. According to the image forming system described in (((12))), when fixing an unfixed image on a medium by heating and cooling a belt-shaped transport and fixing means, it is possible to construct an image forming system that includes a fixing device that can reuse a portion of the heat dissipated to cool the transport and fixing means for heating, thereby reducing the amount of heat required for heating and cooling itself. [Explanation of Symbols]

[0072] 1…Heating fixing means, 1a…Heating source, 2…Transport fixing means, 3…Pressure fixing means, 4…Cooling means, 5…Peeling means, 6…Heat transfer means, 6a…First contact member, 6b…Second contact member, 6c…Heat transfer component, 8…Holding means, 10…Fixing device, 11…Image forming means, CA…Cooling area, FA…Fixing area, G…Unfixed image, S…Medium, P1…First position, P2…Second position

Claims

1. A rotatable heating and fixing means having a heating source, A belt-shaped transport and fixing means is stretched over the heating and fixing means and provided to be circulating, and transports the medium in contact with the image surface of the medium on which the unfixed image is held, A rotatable pressurizing fixing means is positioned opposite the heating fixing means with the transport fixing means in between, and pressurizes to form a fixing area for fixing the unfixed image between itself and the heating fixing means, A cooling means is provided in contact with the back surface of the conveying and fixing means, located downstream of the fixing area in the conveying direction of the medium within the conveying area of ​​the conveying and fixing means, for cooling the conveying and fixing means. A heat transfer means is provided in a non-contact state between the cooling means and the heating means in the internal space on the back surface of the conveying and fixing means, and is in contact with a first position located in the region of the conveying and fixing means after heating and before cooling, and a second position located in the region of the conveying and fixing means after cooling and before heating, and transfers a portion of the heat of the conveying and fixing means from the first position to the second position, A fixing device characterized by being equipped with the following features.

2. In the fixing device according to claim 1, The fixing device is characterized by comprising a heat transfer component that transfers heat from a high-temperature part to a low-temperature part.

3. In the fixing device according to claim 2, The fixing device is characterized in that the heat transfer means comprises: a first contact member made of a heat conductive material that is positioned in contact with the first position on the back surface of the conveying and fixing means and extends along an intersecting direction that intersects the direction of movement of the conveying and fixing means; a second contact member made of a heat conductive material that is positioned in contact with the second position on the back surface of the conveying and fixing means and extends along an intersecting direction that intersects the direction of movement of the conveying and fixing means; and a heat transfer component that is joined between the first contact member and the second contact member.

4. In the fixing device according to claim 2, The fixing device is characterized in that a plurality of heat transfer components are provided at intervals in a direction intersecting the conveying direction of the medium.

5. In the fixing device according to claim 2, The fixing device is characterized in that the heat transfer component is a heat pipe.

6. In the fixing device according to claim 1, The fixing apparatus is characterized in that the heat transfer means is positioned closer to the cooling means than to the heating fixing means.

7. In the fixing device according to claim 1, A fixing device characterized by being provided with a holding means for maintaining the contact state between the heat transfer means and the conveying and fixing means.

8. In the fixing device according to claim 7, The fixing device is characterized in that the holding means is provided upstream of the second position of the conveying and fixing means in the direction of movement of the conveying and fixing means, and is a positioning means that positions the conveying and fixing means such that the heat transfer means maintains contact with the second position.

9. In the fixing device according to claim 7, The conveying and fixing means is positioned opposite the entrance to the cooling area provided by the cooling means, and the opposing rotating means rotates in accordance with the conveying and fixing means, The fixing device is characterized in that the holding means also serves as the opposing rotating means, and the heat transfer means maintains contact with the first position.

10. In the fixing device according to claim 1, The fixing device is characterized in that the heat transfer means has a thermal conductivity that reduces the temperature of the conveying and fixing means that enters the cooling region by the cooling means by 5°C or more at the first position.

11. In the fixing device according to claim 10, The heat transfer means is characterized by having a thermal conductivity such that, taking into account the amount of heat generated by the heating and fixing means and the amount of heat dissipated by the cooling means, the temperature at the point where the medium is peeled from the transport and fixing means is below the threshold temperature necessary to obtain a high-gloss fixed image.

12. A means for creating an unfixed image on a medium, A fixing apparatus according to any one of claims 1 to 11 for fixing an unfixed image held on the medium, An image forming system characterized by comprising the following features.

Images