JP6064823B2 - Fixing apparatus and image forming apparatus - Google Patents

Description

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

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for transferring an image from an intermediate transfer medium to a transfer medium by a transfer roller with a part of the transfer object sandwiched between a base sheet and a peeling prevention sheet.

JP-A-9-30015

  An object of the present invention is to make it easy to remove a raised portion on the surface of a medium formed by peeling an adhesive layer by heat applied by a fixing unit.

  The fixing device according to claim 1 of the present invention applies heat to a toner image formed on a medium having a first sheet member and a second sheet member bonded via an adhesive layer containing an adhesive, and the toner image Fixing means for fixing the medium to the medium, and a shape before peeling of the adhesive layer provided downstream of the fixing means in the transport direction in which the medium is transported and peeled by the heat applied by the fixing means And a pressure member that pressurizes the first and second sheet members in a direction in which the first and second sheet members are pressed against the adhesive layer.

  A fixing device according to a second aspect of the present invention is the fixing device according to the first aspect, wherein the pressure member is a line represented by a rear end on the upstream side in the transport direction of a portion in contact with the medium. The minute portion is provided to be inclined with respect to the width direction of the medium.

  According to a third aspect of the present invention, in the fixing device according to the second aspect, the line segment is positioned on the downstream side in the transport direction as it approaches the end portion from the center in the width direction of the medium. As described above, the pressure member is provided.

  According to a fourth aspect of the present invention, in the fixing device according to any one of the first to third aspects, the toner image is formed on a portion of the medium that is pressed by the pressure member. Determination means for determining whether or not the toner image is formed, and control means for controlling the pressure member to pressurize the medium when the determination means determines that the toner image is formed. Features.

  According to a fifth aspect of the present invention, in the fixing device according to the fourth aspect, the control unit adds the medium when the determination unit determines that the toner image is not formed. The pressure member is controlled so as not to press.

  A fixing device according to a sixth aspect of the present invention is the fixing device according to the fourth aspect, wherein the control unit determines that the toner image is not formed when the determination unit determines that the toner image is not formed. The pressurizing member is controlled so as to pressurize with a pressure stronger than when it is determined that it is formed.

  According to a seventh aspect of the present invention, in the fixing device according to any one of the first to sixth aspects, the pressure member does not include means for heating the member.

  The fixing device according to an eighth aspect of the present invention is the fixing device according to any one of the first to seventh aspects, wherein the pressure member includes a first rotating member that forms a nip region through which the medium passes, and It has a 2nd rotation member, and the mutually opposing surface of the said 1st rotation member and the 2nd rotation member deform | transforms in the said nip area | region, It is characterized by the above-mentioned.

  A fixing device according to a ninth aspect of the present invention is the fixing device according to the eighth aspect, wherein the first rotating member and the second rotating member are moved at a speed higher than that when the medium passes through the fixing unit. It rotates at a speed that passes through the region.

  An image forming apparatus according to a tenth aspect of the present invention includes a fixing device according to any one of the first to ninth aspects, a conveying unit that conveys a medium, and a toner image on the medium conveyed by the conveying unit. And forming means for forming.

According to the first and tenth aspects of the present invention, it is possible to make it easier to remove the raised portion on the surface of the medium formed by peeling off the adhesive layer by the heat applied by the fixing means, compared to the case where no pressure member is provided. .
According to the second aspect of the present invention, it is possible to make the air in the medium less likely to get in the way when removing the raised portions on the surface of the medium as compared with the case where there is no inclination of the line segment.
According to the third aspect of the present invention, it is possible to make it easier to remove the raised portion on the surface of the medium as compared with a case where the end portion is not provided with a configuration in which the line segment is inclined so as to be located on the downstream side in the transport direction.

According to the fourth aspect of the present invention, the surface of the medium is raised as compared with the case where the pressure control based on the result of determining whether or not the toner image is formed on the portion to be pressed of the medium is not performed. The portion can be made difficult to remain on the toner image after fixing.
According to the fifth aspect of the present invention, the adhesive force of the adhesive layer is less likely to be smaller than when the pressure is continuously applied even if it is determined that the toner image is not formed on the portion to be pressed. be able to.
According to the sixth aspect of the present invention, the medium after fixing the toner image can be stored in a smaller space as compared with the case where no pressure is applied as in the present invention.

According to the invention which concerns on Claim 7, it is made difficult to peel the part which the contact bonding layer peeled and adhered again compared with the case where a pressurizing member heats its own member and applies the heat to a medium. it can.
According to the eighth aspect of the present invention, it is possible to prevent the first rotating member and the second rotating member from bending the medium passing through the nip region.
According to the ninth aspect of the present invention, compared to the case where the first rotating member and the second rotating member are not rotated at the speed shown in the present invention, the raised portion of the medium surface caused by the peeled portion is less likely to remain. can do.

1 is a diagram illustrating an example of a hardware configuration of an image forming system according to a first embodiment. The figure which shows an example of the hardware constitutions of an image formation part. The figure for demonstrating the protruding part of the medium surface. The figure for demonstrating the shape of a pressurization member. The figure which shows an example of a mode that a gap | interval passes a nip area | region. The figure which shows an example of a mode that a gap | interval passes a nip area | region. The figure which shows an example of a mode that a gap | interval passes a nip area | region. The figure which shows an example of the hardware constitutions of the pressurization member of 2nd Embodiment. 1 is a diagram illustrating an example of a functional configuration of an image forming system. The figure which shows an example of the protruding part of the medium surface. FIG. 6 is a flowchart showing an example of the operation of the image forming system in the pressure control process. The figure which shows an example of the pressurization member of a modification. The flowchart which shows an example of the operation | movement in the pressurization control processing of a modification.

[1] First Embodiment [1-1] Hardware Configuration [1-1-1] Forming Unit and Conveying Unit FIG. 1 is a diagram illustrating an example of a hardware configuration of an image forming system according to the first embodiment. . In FIG. 1A, an image forming system 1 including a paper feeding device 2, an image forming device 3, and a post-processing device 4 is shown. The sheet feeding device 2 supplies the medium P1 to the image forming apparatus 3, and the image forming apparatus 3 forms an image on the supplied medium P1 by electrophotography. The post-processing device 4 performs post-processing such as winding of the medium P1 on which the image is formed. That is, the medium P1 is transported in the direction indicated by the arrow in the drawing (hereinafter referred to as “transport direction”) A1.

  In the present embodiment, the medium P1 is a belt-like medium that has a sheet shape and is elongated in the transport direction A1, and is a so-called continuous paper. The medium P1 is conveyed in a continuous manner from a place where the medium P1 is supplied (paper feeding device 2) to a place where the image is formed and stored (post-processing device 4). Images are continuously formed by the image forming apparatus 3 while the medium P1 is being conveyed. The image forming apparatus 3 includes a control device 5 and an image forming unit 6.

  The control device 5 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a real-time clock, and the CPU stores a program stored in the ROM or the storage unit using the RAM as a work area. To control the operation of each device. The real time clock calculates the current date and time and notifies the CPU. The control device 5 includes a hard disk and stores data and programs used by the CPU for control. The control device 5 is connected to an external device via a network (not shown). When image data is transmitted from the external device, the control device 5 controls the paper feeding device 2, the image forming device 3, and the post-processing device 4. An image forming process for forming an image indicated by the image data on the medium P1 is performed. As described above, the image forming system 1 is a computer that mainly processes information called an image by a CPU. The image forming unit 6 will be described with reference to FIG.

  FIG. 2 is a diagram illustrating an example of a hardware configuration of the image forming unit 6. The image forming unit 6 forms a color image by fixing four types of toners of yellow (Y), magenta (M), cyan (C), and black (K), respectively, on a recording medium such as paper. In the image forming unit 6, a photosensitive drum 11, a charging device, a developing unit 12, and a primary transfer roll 14 are intermediately transferred in the direction of an arrow A 2 for each of Y, M, C, and K colors in order. It is provided along the belt 15. In FIG. 2, alphabets (Y, M, C, K) are added to the end of the reference numerals of these parts, indicating that each part is related to image formation of colors corresponding to the alphabets. In the case where it is not necessary to distinguish each of these components, the description will be made with the alphabet at the end of the reference numerals omitted.

  The photosensitive drum 11 rotates in the direction of the arrow A3 and holds an electrostatic latent image and a toner image formed on the surface. The surface of the photosensitive drum 11 is charged to a predetermined potential by a charging device. The exposure unit 13 irradiates (exposes) the surface of the photosensitive layer charged with light (exposure light) whose intensity and irradiation position are controlled according to the above-described image data, and displays an electrostatic latent image representing the image indicated by the image data. Form an image. The developing unit 12 supplies a developer containing charged toner to the photosensitive drum 11 to develop the electrostatic latent image into a toner image. The primary transfer roll 14 is provided at a position facing the photosensitive drum 11 with the intermediate transfer belt 15 interposed therebetween. Due to the voltage applied to the primary transfer roll 14 and the photosensitive drum 11, a potential difference is generated between the photosensitive drum 11 and the intermediate transfer belt 15, and the charged toner moves to the intermediate transfer belt 15 (primary transfer).

  The image forming unit 6 includes an intermediate transfer belt 15, a secondary transfer roll 16, a backup roll 17, a transport roll 20, and a fixing device 7. The intermediate transfer belt 15 is an endless belt and holds the toner image that has been primarily transferred. The intermediate transfer belt 15 is rotatably supported by a plurality of support rolls, and is rotated in the direction of arrow A2 by being given a driving force. To the intermediate transfer belt 15, toner images having colors K, C, M, and Y are primarily transferred in order from the photosensitive drum 11 </ b> K. The secondary transfer roll 16 and the backup roll 17 are provided to face each other with the intermediate transfer belt 15 in between, and form a nip portion.

  The transport roll 20 transports the medium P1 in the transport direction A1 in cooperation with the paper feeding device 2 and the post-processing device 4 shown in FIG. The paper feeding device 2, the transport roll 20, and the post-processing device 4 are examples of a transport unit that transports the medium P1. The transport roll 20 transports the medium P1 to the nip portion. The medium P1 contacts the intermediate transfer belt 15 at the nip portion. A voltage is applied to the secondary transfer roll 16 so as to generate a potential difference with the backup roll 17, and the toner image is secondarily transferred from the intermediate transfer belt 15 to the medium P1 by this voltage. Thus, a toner image is formed on the medium P1. As described above, the photosensitive drum 11, the exposure unit 13, the developing unit 12, the primary transfer roll 14, the intermediate transfer belt 15, the secondary transfer roll 16, and the backup roll 17 form a toner image on the medium conveyed by the conveyance unit. It is an example of the forming means.

[1-1-2] Fixing Device The fixing device 7 is provided downstream of the secondary transfer roll 16 and the backup roll 17 in the transport direction A1, and the toner image formed on the medium P1 by the forming unit is applied to the medium P1. This is a fixing device. As described above, the image forming system 1 includes the conveying unit, the forming unit, and the fixing device 7, and these cooperate to form an image (fixed toner image) on the medium P <b> 1. The fixing device 7 includes a fixing unit 30 and a pressure member 40.

[1-1-2-1] Fixing Unit The fixing unit 30 is an example of a fixing unit that applies heat and pressure to the toner image formed on the medium P1 and fixes the toner image on the medium P1. The fixing unit 30 includes, for example, two rotating bodies (for example, rollers and endless belts) and a heating unit (for example, a halogen lamp) for heating them. The fixing unit 30 applies heat and pressure to the toner image when the rotating body heated by the heating unit contacts the medium P1. The heat applied at this time is also transmitted to the medium P1. In the present embodiment, the surface of the medium P1 heated by the fixing unit 30 may be raised. Hereinafter, the raised portion of the surface of the medium is referred to as “the raised portion of the medium surface”. The raised portion on the surface of the medium will be described with reference to FIG.

  FIG. 3 is a diagram for explaining a raised portion on the surface of the medium. FIG. 3 shows a state in which the medium P1 transported in the transport direction A1 is viewed from the side. As shown in FIG. 3A, the medium P1 includes a first sheet member P11, a second sheet member P12, and an adhesive layer P13. The first sheet member P11 and the second sheet member P12 are sheet-like members formed of paper, film, PET (Polyethylene terephthalate), or the like. The adhesive layer P13 is a layer containing an adhesive. The first sheet member P11 and the second sheet member P12 are bonded via an adhesive layer P13. The medium P1 is, for example, label paper, and the first sheet member P11 is cut. When the first sheet member P11 is peeled along the notch, the adhesive layer P13 bonded to one surface is also peeled off. The first sheet member P11 and the adhesive layer P13 thus peeled off are used as labels to be attached to arbitrary places. The cut into the first sheet member P11 may be made after image formation.

  FIG. 3B shows a state where the raised portion Q1 is generated on the medium P1. When heat is applied to the medium P1 by the fixing unit 30, the adhesive layer P13 may be softened by the heat. In such a state, a force is applied in a direction in which the medium P1 is contracted along the transport direction A1, or a pulling force is applied in a direction A4 along the perpendicular to the surface of the medium P1 (hereinafter referred to as “vertical direction”). The adhesive layer P13 may peel off. There are three states of peeling here. For example, as shown in FIG. 3B, the adhesive layer P13 is separated in the vertical direction A4, and the separated one and the other are separated from each other. In addition to this, the adhesive layer P13 is not separated and is peeled from the second sheet member P12 while being adhered to the first sheet member P11, and is peeled from the first sheet member P11 while being adhered to the second sheet member P12. There is. Regardless of which peeling occurs, a gap (R1 in the example of FIG. 3) occurs in the portion where the adhesive layer P13 peels. That is, the gap R1 is a space generated in the peeled portion where the adhesive layer P13 is softened and peeled off by the heat applied by the fixing unit 30.

  When the gap R1 is generated inside the medium P1, the first sheet member P11 and the second sheet member P12 are projected in the vertical direction A4 by that amount, and the protruding portions like streaks on the surface of the medium P1, that is, the raised portions Q11 and Q12 are formed. Each will occur. FIG. 3C shows a state in which the medium P1 is viewed along the vertical direction. In FIG. 3C, the width direction A5 of the medium P1 is shown. The width direction A5 is a direction that intersects the transport direction A1.

  Raised portions Q11, Q21, and Q31 are formed on the medium P1. Each of these raised portions extends linearly along the width direction A5. The raised portion Q11 extends from one end in the width direction of the medium P1 to the other end. The raised portion Q21 extends from one end in the width direction of the medium P1 to the center and is interrupted there. The raised portion Q31 is not connected to the end in the width direction of the medium P1, and extends from the middle to the middle in the width direction. When the medium P1 is heated by the fixing unit 30, such a raised portion may occur.

[1-1-2-2] Pressure Member The pressure member 40 is provided downstream of the fixing unit 30 in the transport direction A1, and presses the first sheet member P11 and the second sheet member P12 against the adhesive layer P13. It is an example of the member pressurized in a direction.
FIG. 4 is a view for explaining the shape of the pressure member 40. FIG. 4A shows a state in which the pressing member 40 is viewed in the transport direction A1. The pressure member 40 includes a first rotating member 410 and a second rotating member 420 (hereinafter referred to as “rotating member 400” unless they are particularly distinguished). The first rotating member 410 and the second rotating member 420 are members that rotate about axes B1 and B2 extending along the width direction A5, respectively. The first rotating member 410 and the second rotating member 420 are arranged with the medium P1 interposed therebetween, and form a nip region N1 through which the medium P1 passes. In this embodiment, the rotating member 400 has a cylindrical shape and is a roller that is deformed when pressure is applied. Note that the rotating member 400 may be, for example, an endless belt as long as it is rotatably supported and forms a nip region.

  The first rotating member 410 and the second rotating member 420 are supported so as to press each other in the direction along the vertical direction A4 with the medium P1 interposed therebetween. Therefore, the rotating member 400 shown in FIG. 4A is deformed at the portion in contact with the medium P1. In FIG.4 (b), the rotation member 400 of the state which is not deform | transforming is shown. The rotating member 400 has a dimension in which the cross-sectional diameter at the center C1 in the width direction A5 is L1, the diameter at the end C2 is L2 (L1> L2), and the length in the width direction from the end C2 to the center C1 is L3. ing. The diameter of the rotating member 400 becomes smaller than L1 by a length proportional to the distance from the center C1 as it approaches the end C2 from the center C1, and becomes L2 at the end C2. That is, the rotating member 400 has a shape in which the lower bases of two truncated cones having a lower base diameter of L1, an upper base diameter of L2 and a height of L3 are connected to each other.

  FIG. 4C shows the pressing member 40 and the end face of the medium P1 as viewed in the direction of arrows II shown in FIG. As shown in FIGS. 4A and 4C, in the nip region N1, the first rotating member 410 and the second rotating member 420 are deformed and the surfaces facing each other are flat. The first rotation member 410 rotates about the axis B1 in the rotation direction A6 indicated by the arrow in the drawing, and the second rotation member 420 rotates about the axis B2 in the rotation direction A7 indicated by the arrow in the drawing. . As the first rotating member 410 and the second rotating member 420 rotate in this manner, the pressure member 40 transports the medium P1 in the transport direction A1.

  In the present embodiment, the first rotating member 410 and the second rotating member 420 rotate at a speed that allows the medium to pass through the nip region N <b> 1 at a higher speed than when the medium passes through the fixing unit 30. However, the medium P1 does not actually pass through the nip region N1 at that speed. A portion of the medium P1 passing through the fixing portion 30 (hereinafter referred to as “first passage portion”) and a portion passing through the nip region N1 (hereinafter referred to as “second passage portion”) are connected. The speed of the first and second passage portions in the transport direction A1 is constant. The surfaces of both rotating members that are in contact with the second passage section move in the transport direction A1 at a speed faster than that of the medium P1, while causing slippage between the second passage section. As a result, a portion that is sandwiched between the first and second passage portions (hereinafter referred to as “sandwich portion”; for example, p1 shown in FIG. 2) is subjected to a force that pulls outward along the transport direction A1. Further, as shown in FIG. 4, the pressure member 40 does not include means for heating the member. For this reason, the pressurizing member 40 pressurizes the medium P1, that is, applies pressure, but does not heat the member and apply the heat to the medium P1.

A state when the pressing member 40 pressurizes the first sheet member P11 and the second sheet member P12, that is, the medium P1, will be described with reference to FIGS.
FIG. 5 is a diagram illustrating an example of how the gap R1 passes through the nip region N1. In this example, a state in which the nip region N1 is viewed from the direction along the width direction A5 illustrated in FIG. 4 and the like is illustrated. As shown in FIG. 5, the first rotating member 410 and the second rotating member 420, that is, the pressing member 40 pressurize the first sheet member P11 and the second sheet member P12 in a direction to press against the adhesive layer P13. Specifically, the direction in which the first sheet member P11 is pressed against the adhesive layer P13 is a downward direction in the vertical direction A4, and the direction in which the second sheet member P12 is pressed against the adhesive layer P13 is an upward direction in the vertical direction A4. It is. The first rotating member 410 and the second rotating member 420 are made of these sheet members via contact portions M11 and M12 (hereinafter referred to as contact portions M10 unless otherwise distinguished) that are in contact with the medium P1. Is pressurized.

  FIG. 5A shows the gap R1 immediately before reaching the nip region N1. In FIG. 5B, the conveyance direction A1 side of the gap R1 reaches the nip region N1, and the adhesive layer P13 that has been peeled back returns to the shape before peeling due to the pressure applied from the rotating member 400. As described above, the pressure member 40 is a first sheet having a pressure close to the shape before the adhesive layer P13 peeled by the heat applied by the fixing unit 30 is peeled (hereinafter referred to as “first pressure”). The member P11 and the second sheet member P12 are pressurized.

  In the image forming system 1, for example, when the adhesive layer P <b> 13 peels and a raised portion is generated on the medium P <b> 1, an experiment is performed to remove the raised portion by pressurization, and a pressure that can remove the raised portion is obtained in advance as the first pressure. Just keep it. The first pressure may be determined depending on the type of medium. The shape before the adhesive layer P13 is peeled is a shape when no gap or raised portion is generated, as indicated by S1 in FIG. More specifically, in the gap R1, the adhesive layer P13 that has been separated into two layers is returned to one layer, and the surfaces in contact with the first sheet member P11 and the second sheet member P12 are in the transport direction A1. It is the shape which became the surface along.

  In FIG.5 (c), all the parts in which the gap | interval R1 produced have returned to the shape before peeling. At this time, if the adhesive force of the adhesive contained in the adhesive layer P13 remains sufficiently, the shape before peeling is maintained as it is. In other words, the peeled adhesive layer P13 is bonded again. The portion bonded again in this way is referred to as a “rebonding portion” (rebonding portion S1 in the example of FIG. 5). In FIG. 5B, the gap R1 is reduced by the amount that the rebonding portion S1 is formed. In FIG.5 (c), all the part which was the space | interval R1 becomes the rebonding part S1, and the raised parts Q11 and Q12 are also lost in connection with this. In the image forming system 1, as described above, the pressure applied to each sheet member when the adhesive layer P13 that has approached the original shape is again adhered and becomes a re-adhesion portion as described above. The first pressure is determined.

  FIG. 6 is a diagram illustrating an example of how the gap R1 passes through the nip region N1. FIG. 6 shows a state in which the medium P1 is viewed from the direction along the vertical direction A4 shown in FIG. Moreover, in FIG. 6, only the contact part M10 mentioned above among the rotating members 400 is shown hatched. Since the diameter of the rotating member 400 increases as the rotating member 400 approaches the center C1 shown in FIG. 4, the contact portion M10 is centered from the end D2 in the width direction A5 as shown in FIG. As it approaches D1, the length in the transport direction A1 increases. In other words, the contact portion M10 has a shape in which the bases of two trapezoids are connected at the center D1. The contact portion M10 indicates a region where the medium P1 is pressed by the rotating member 400.

  In FIG. 6, line segments T1 and T2 represented by the rear end on the upstream side in the conveyance direction A1 of the contact portion M10 are shown. Both the line segments T1 and T2 are inclined with respect to the width direction A5. Thus, the pressure member 40 is provided such that the line segment represented by the upstream rear end of the contact portion M10 in the transport direction A1 is inclined with respect to the width direction A5 of the medium P1. More specifically, the pressurizing member 40 is provided so that the line segments T1 and T2 are positioned on the downstream side in the transport direction A1 from the center D1 in the width direction A5 of the medium P1 toward the end D2. .

  In FIG. 6, the gap R1 is not shown directly, but the gap R1 is generated at a position that substantially overlaps the raised portion Q11. In FIG. 6A, the position of the center D1 in the width direction A5 of the gap R1 and the raised portion Q11 reaches the contact portion M10, and a part of the gap R1 is pressurized to form the rebonding portion S1. 6B and 6C, the medium P1 advances in the transport direction A1, respectively, and the rebonding portion S1 spreads in the directions of arrows A8 and A9 along the width direction A5, along with the gap R1 and the raised portion. It shows how Q11 becomes smaller. At this time, the air in the gap R1 is pushed in the directions of the arrows A8 and A9 shown in the drawing and exits from the inside of the medium P1 to the outside.

  If the gap is causing the raised portion Q21 shown in FIG. 3 (c), the gap is connected to the outside at one end in the width direction A5 like the gap R1, and is thus bonded again by the pressure member 40. Sometimes the air in the gap exits from the end of the medium to the outside of the medium P1. On the other hand, the gap in which the raised portion Q31 shown in FIG. 3C is generated (this gap is referred to as gap R3) is not connected to the outside of the medium P1. Actually, when the gap R3 is generated, air has entered the gap R3 from somewhere through a certain path. If the path is connected, the gap R3 is directly as shown in the example shown in FIG. It becomes the rebonding part S3. However, after the gap R3 is generated, the path may not be able to pass. Such a case will be described with reference to FIG.

  FIG. 7 is a diagram illustrating an example of a state in which the gap R3 passes through the nip region N1. FIG. 7A shows that the gap R3 and the raised portion Q31 have started to be pressed by the contact portion M10. A part of the gap R3 is pressurized to form a rebonding portion S3. In the remaining portion of the gap R3, the internal air contracts, and the atmospheric pressure is higher than before the pressure is started. FIG. 7B shows a state in which the portion that has been pressurized and becomes the re-bonding portion S3 is increased, and the gap R3 itself is expanded in the direction of the arrow A8 by being pushed by the higher atmospheric pressure inside the gap R3. Has been. FIG. 7C shows a state where the gap R3 is expanded until it is connected to the end portion D2. Thus, the air in the gap R3 goes out of the medium P1 from the part connected to the end D2.

[1-2] Effects According to the First Embodiment In the present embodiment, the pressure member 40 is the first sheet member at the above-described first pressure (pressure close to the shape before the peeled adhesive layer P13 peels). P11 and the second sheet member P12 are pressurized. As a result, when the adhesive force of the adhesive contained in the part where the adhesive layer P13 has peeled remains sufficiently, the peeled part is bonded again, and the raised part generated in the peeled part is removed accordingly. It is. According to the present embodiment, compared with the case where the pressure member 40 is not provided, the surface of the medium formed by the separation of the adhesive layer P13 due to the heat applied by the fixing unit (the fixing unit 30 in the present embodiment). The raised portion is easily removed.

  In this embodiment, line segments T1 and T2 shown in FIG. 6 are inclined with respect to the width direction A5. Since the pressurization to the medium P1 is performed from the point where the line segment is touched, such an inclination causes the air in the gap generated along the width direction A5 to be widened as shown in FIG. The part peeled while pushing in the direction A5 can be returned to the shape before peeling. As a result, the air in the medium is less likely to get in the way when removing the raised portions on the surface of the medium as compared with the case where there is no inclination of the line segment.

  In particular, in the present embodiment, the line segments T1 and T2 are inclined so as to be positioned on the downstream side in the transport direction A1 as they approach the end D2 from the center D1 in the width direction A5 of the medium P1. Thus, the distance for pushing the air in the gap in the width direction A5 does not become longer than half of the length of the medium P1 in the width direction A5. When this distance is too long, the gap passes through the nip region N1 before all the air in the gap is pushed out of the medium P1, and the raised portion of the surface of the medium cannot easily be removed. In the present embodiment, as described above, by tilting the line segment, the protruding portion on the surface of the medium is removed as compared with the case where the end portion is not provided with a configuration in which the line segment is tilted so as to be positioned on the downstream side in the transport direction. It becomes easy.

  Further, in the present embodiment, as described above, since the pressing member 40 does not include means for heating the self member, the self member is not heated and the heat is not applied to the medium P1. When such heat is applied to the medium P1, the adhesive layer P13 is easily softened again compared to the case where the heat is not applied, and the portion that has become the re-bonded portion is easily peeled again as shown in FIG. . In this embodiment, compared with the case where the pressurizing member 40 heats its own member and applies the heat to the medium P1, the portion that has become the rebonding portion is less likely to peel off.

  Moreover, in this embodiment, as shown in FIG. 4, the mutually opposing surface of the 1st rotation member 410 and the 2nd rotation member 420 is planar in the nip area | region N1. As a result, the first rotating member 410 and the second rotating member 420 do not curve the medium P1 that passes through the nip region N1.

  In the present embodiment, the rotating member 400 rotates at a speed at which the medium P1 passes through the nip region N1 at a speed faster than when the medium P1 passes through the fixing unit 30. On the other hand, when the medium P1 passes through the nip region N1 at a slower speed than when the medium P1 passes through the fixing unit 30, the gap as shown in FIG. The height from the surface of the medium increases. As a result, as shown in FIG. 5, when passing through the nip region N1, the raised portion of the medium surface is pushed by the rotating member 400 and bent, and the raised portion may remain even if the gap is removed. According to the present embodiment, when the rotating member 400 rotates at the above speed, a force pulling outward along the transport direction A1 is applied to the sandwiched portion p1 shown in FIG. 2, and the gap extends in the transport direction A1. Thus, the height of the raised portion is reduced, so that the raised portion on the surface of the medium is less likely to remain than when the rotating member 400 is not rotated at such a speed.

[2] Second Embodiment Hereinafter, a second embodiment of the present invention will be described focusing on differences from the first embodiment. In the second embodiment, control is performed to change the pressure applied by the pressure member 40 between a region where the toner image is fixed (hereinafter referred to as “fixing region”) and a region where the toner image is fixed (hereinafter referred to as “non-fixing region”). Is called.

[2-1] Hardware Configuration FIG. 8 is a diagram illustrating an example of a hardware configuration of a pressure member according to the second embodiment. In FIG. 8, a first rotating member 410a and a second rotating member 420a (hereinafter referred to as a rotating member 400a unless they are particularly distinguished), and driving members 510 and 520 for driving the rotating member 400 in the vertical direction A4, respectively. A pressure member 40a is shown (hereinafter referred to as a drive member 500 unless these are particularly distinguished). In this example, the rotating member 400a has a cylindrical shape. The driving member 500 is controlled by the control device 5 shown in FIG. 1 to move the rotating member 400a in the vertical direction A4.

[2-2] Functional Configuration In the image forming system 1, a pressurization control process for controlling the pressurization of the medium P1 by the pressurizing member 40a is performed based on the hardware configuration described above. Specifically, the control device 5 executes a program to control each unit, and the functions described below are realized, whereby the pressurization control process is performed.

  FIG. 9 is a diagram illustrating an example of a functional configuration of the image forming system 1. The image forming system 1 includes a determination unit 101 and a control unit 102. The determination unit 101 is an example of a unit that determines whether a toner image is formed on a portion of the medium P1 that is pressed by the pressure member 40a. The fact that a toner image is formed in a portion to be pressed means a state where the toner image is pressed. Hereinafter, this state is referred to as a “toner image pressurized state”. That is, the determination unit 101 determines whether the toner image is in a pressurized state. The determination unit 101 is a function realized by, for example, the control device 5, the formation unit, and the conveyance unit described above. The control device 5 controls the transport unit to transport the medium P1, and controls the forming unit to form a toner image on the transported medium P1.

  The control device 5 determines the time (hereinafter referred to as “arrival time”) when the formed toner image reaches the nip region N1 of the pressure member 40a based on the timing of forming the toner image on the medium P1 and the speed of the conveyed medium P1. ) And the time to leave (hereinafter referred to as “leave time”). When the current time is included between the arrival time and the departure time, the control device 5 is in a toner image pressurization state (a toner image is applied to a portion of the medium P1 that is pressed by the pressurizing member 40a). If it is not included, it is determined that the toner image is not pressed (no toner image is formed in that portion). The determination unit 101 makes the above determination in this way, and notifies the control unit 102 of the determination result.

  The control unit 102 is an example of a unit that controls the pressure member 40a so as to press the medium P1 when the determination unit 101 determines that a toner image is formed. In the present embodiment, the control unit 102 controls the pressing member 40a so as not to pressurize the medium P1 when it is determined that the toner image is not formed. The control means 102 is a function realized by the control device 5. The control device 5 controls the driving member 500 shown in FIG. 8 when the result determined to be the toner image pressurization state is notified from the determination means 101 (hereinafter referred to as “second pressure”). ), The rotating member 400 is moved so as to pressurize the medium P1, and when the determination unit 101 notifies that the toner image is not pressed, the driving member 500 is controlled so that the rotating member 400 The rotating member 400 is moved so as not to contact the medium P1, that is, not pressurize the medium P1.

  The second pressure used at this time may be a pressure common to the first pressure described above, or may be a different pressure. In the image forming system, for example, when the pressure is applied by the pressure member 40a, the pressure at which the gap moves to the upstream side in the transport direction is confirmed by an experiment, and the pressure may be determined as the second pressure. The control means 102 performs the above control in this way.

The state of the raised portion on the surface of the medium when the control means 102 performs the above control will be described with reference to FIG.
FIG. 10 is a diagram illustrating an example of a raised portion on the surface of the medium. In FIG. 10, the medium P1 on which the toner images U1 and U2 are formed is transported in the transport direction A1. FIG. 10A shows fixing areas V1 and V2 where toner images U1 and U2 are formed in the width direction A5, respectively, and non-fixing areas W1 and W2 where no toner image is formed in the width direction A5. ing. In FIG. 10A, the pressing member 40a presses the medium P1 in the fixing region V1, and the contact portion M2 is shown.

  In this example, the raised portion Q41 that does not extend to either end in the width direction A5 of the medium P1 is generated on the toner image U1, but when the pressure member 40a is pressed at the contact portion M2, It moves in the direction opposite to the conveyance direction A1. This is because the air in the gap R4 is pushed in the direction opposite to the conveying direction A1 while the gap R4 causing the raised portion Q41 is pressurized by the pressure member 40a to become a re-bonding portion, and bonded by the air pressure. It represents that the layer P13 is peeled off to form a new gap R4. Thus, when the gap R4 is pressurized by the pressure member 40a, the gap R4 moves in the direction opposite to the transport direction A1. In FIG. 10, the gap R4 before the movement, that is, the position where the gap R4 is generated is indicated by a two-dot chain line rectangle X4.

  In FIG. 10B, the contact portion M2 has reached the front end on the downstream side in the transport direction A1 of the fixing region V1, and the gap R4 (and the raised portion Q41) has moved to the non-fixing region W2. When the contact portion M2 reaches the non-fixing area W2, the determination unit 101 determines that the toner image is not pressed, and the control unit 102 controls the pressing member 40a so as not to press the medium P1. For this reason, as shown in FIG. 10C, the contact portion M2 disappears, and the gap R4 stops moving and remains in the non-fixing region W2.

[2-3] Operation FIG. 11 is a flowchart showing an example of the operation of the image forming system 1 in the pressure control process. The pressure control process is performed when the image forming system 1 is performing a process of forming an image (hereinafter referred to as “image forming process”). First, the image forming system 1 starts an image forming process based on a user operation or the like (step S11). Next, the image forming system 1 determines whether or not the pressure member 40a is in a toner image pressure state (step S12). If the image forming system 1 determines that the toner image is in a pressurized state (YES), the image forming system 1 performs control to pressurize the medium P1 (hereinafter referred to as “first pressure control”) (step S13), and adds the toner image. If it is determined that the pressure state is not reached (NO), control for not pressurizing the medium P1 (hereinafter referred to as “non-pressurization control”) is performed (step S14).

  Subsequently, the image forming system 1 determines whether or not the image forming process is completed (step S15). If the image forming system 1 determines that the image forming process has not ended (NO), the image forming system 1 returns to step S12 to perform an operation. If it is determined that the image forming process has ended (YES), the image forming system 1 The pressure control process is terminated. Step S12 is an operation performed by the determination unit 101, and steps S13 and S14 are operations performed by the control unit 102 and the pressure member 40a.

[2-4] Effects According to Second Embodiment In this embodiment, as shown in FIG. 10, the gap in the region determined to be in the toner image pressurization state is pressurized by the pressurizing member 40a to add the toner image. It moves to the area determined not to be in the pressure state. As a result, compared to the case where the pressure control based on the result of determining whether the toner image is formed on the pressed portion of the medium is not performed, the protruding portion on the surface of the medium is the toner image after the fixing. It ’s harder to stay on top.

  Since the movement of the gap due to the pressurization is performed while repeatedly peeling and bonding again the adhesive layer P13, the adhesive force of the adhesive layer P13 after the gap has moved may be reduced. In the present embodiment, when the determination unit 101 determines that a toner image is not formed, the medium P1 is not pressurized. Thereby, compared with the case where pressurization is continued as it is, the adhesive force of the adhesive layer is less likely to be reduced. Note that the term "as it is" here means that pressurization is continued without changing the pressure.

[3] Modifications Each of the above-described embodiments is merely an example of the implementation of the present invention, and may be modified as follows. Moreover, you may implement each embodiment mentioned above and each modification shown below, combining each as needed.

[3-1] Shape and Arrangement of Pressure Member The pressure member is not limited to the shape and arrangement described in the first and second embodiments.
FIG. 12 is a diagram illustrating an example of the pressure member of the present modification. FIG. 12 shows a pressurizing member 40b including a rotating member 400b in the shape of a cylinder that rotates around an axis B3 inclined by an angle θ1 with respect to the width direction A5. In FIG. 12, the rotating member 400b hidden behind the rotating member 400b and the contact portion M3 where the medium P1 comes into contact are shown by broken lines and hatching.

  The contact portion M3 has a parallelogram shape having sides along the axis B3 and sides along the transport direction A1. Therefore, the line segment T3 represented by the rear end on the upstream side in the transport direction A1 of the contact portion M3 is one of the sides along the axis B3, and is therefore inclined by the angle θ1 with respect to the width direction A5. In this way, the pressure member 40b is provided such that the line segment T3 is positioned on the downstream side in the transport direction A1 as it approaches the other end from the one end in the width direction A5 of the medium P1. Yes. As a result, even in the present modified example, air in the medium is less likely to get in the way when removing the raised portions on the surface of the medium as compared to the case where there is no inclination of the line segment as in the example described in the explanation of FIG. Become.

  In this modification, a drive member that moves the pressure member 40b to change the direction of the axis B3 may be provided. When the direction of the axis B3 changes, the angle θ formed by the line segment T3 and the width direction A5 also changes accordingly. As the angle θ is larger, the force for pushing the air in the gap in the width direction A5 becomes stronger, and the time for pressurizing the gap in the width direction A5 like the gap R1 shown in FIG. 6 becomes longer. Therefore, as the angle θ is larger, the raised portion of the medium surface is more reliably removed. For example, when a sensor (for example, a sensor for detecting the undulation of the surface of an object) that detects the raised portion of the surface of the medium is provided on the downstream side in the conveying direction of the pressure member 40b, and the raised portion is detected to a certain degree or more. The angle θ is increased, and when the raised portion is not detected, the angle θ is decreased.

[3-2] Shape of Line Segment In the first embodiment and the like described above, the line segments represented by the rear end on the upstream side in the conveyance direction A1 of the contact portion are all linear, but the present invention is not limited thereto. . This line segment may be a curve or may be stepped. In either case, each line segment only needs to be inclined with respect to the width direction A5. Note that a portion along the width direction A5 may be included in the line segment. Even in that case, the air in the gap is pushed upstream in the conveyance direction A1 in that portion, but in the other portions, it is pushed in the width direction A5 as in the above example. The air in the medium is less likely to get in the way when removing.

[3-3] Pressurization in Non-fixing Area In the second embodiment, the control unit 102 may perform control different from the above. For example, when the determination unit 101 determines that the toner image is not formed, the control unit 102 forms a toner image instead of controlling the pressing member so as not to press the medium. The pressurizing member is controlled so as to pressurize with a pressure stronger than that determined.

  FIG. 13 is a flowchart showing an example of the operation of the image forming system 1 in the pressurization control process of the present modification. In this example, the image forming system 1 performs the operations of steps S11 and S12 shown in FIG. 11, and if it is determined in step S12 that the toner image is not pressed (NO), the first pressurization in step S13. In the control, control is performed to pressurize the medium P1 at a pressure stronger than the pressure applied to the medium P1 (hereinafter referred to as “second pressurization control”) (step S21). Step S21 is an operation performed by the control means 102 and the pressure member.

  The gap generated by peeling off the adhesive layer P13 is a certain pressure (for example, the second pressure described in the second embodiment) depending on the characteristics and state of the adhesive contained in the adhesive layer P13, the size of the gap, and the like. When the pressure is applied, the air in the gap causes separation of the adjacent adhesive layer P13 and moves as shown in FIG. 10, but when the pressure is increased with a higher pressure (hereinafter referred to as “third pressure”). In some cases, the air in the gap passes through the adhesive layer P13 and the cut of the sheet member to the outside, and becomes a re-bonded portion as shown in FIG. Thereby, compared with the case where the pressurization described in the present modification is not performed, the protruding portions of the medium surface are easily reduced, the media P1 are easily brought into close contact with each other, and the media P1 is stored in a smaller space.

For example, if the post-processing device 4 shown in FIG. 1 winds up the medium P1, the medium P1 is wound up at a higher density and closer to a circle. Also in this case, as in the first and second pressures, for example, a pressure at which the raised portion of the medium surface disappears in an experiment may be confirmed, and the pressure may be determined as the third pressure.
As described above, when the determination unit 101 determines that the toner image is not pressed, the control unit 102 presses the pressure member 40 so as not to press the medium P1 as described in the second embodiment. Or, as described in the present modification, the pressure member is controlled so as to pressurize at a pressure stronger than when it is determined that a toner image is formed.

[3-4] Determination of Existence of Raised Portions In the second embodiment, whether or not a toner image is formed in a toner image pressurization state, that is, a portion of the medium P1 that is pressed by the pressurizing member 40a. Although it determined, it is not restricted to this, For example, you may determine whether the protruding part has arisen in the part (that is, whether there exists a protruding part). In this case, the determination unit 101 performs this determination using, for example, a sensor that detects the height of the medium surface. When it is determined that the raised portion is generated, the control unit 102 controls the pressurizing member 40a so as to pressurize the medium P1. In the modified example 3-3, it is determined that a toner image is not formed on a portion of the medium P1 that is pressed by the pressing member 40a, and a protruding portion is generated on the portion. When the determination is made, the control member 102 may control the pressurizing member so as to pressurize with the third pressure. According to this modification, only the portion of the medium where the raised portion is generated is pressurized.

[3-5] Fixing Unit The heating unit included in the fixing unit may be an IH (Induction Heating) heater in addition to the halogen lamp described above. In addition, the fixing unit may be a unit that does not use a roller or a belt and irradiates a laser beam or the like to heat and fix a toner image (so-called flash fixing). In this case, the fixing unit functions as a fixing unit that applies heat to the toner image formed on the medium to fix the toner image on the medium. In any case, if the adhesive layer of the medium is softened and peeled off due to the heat applied from the fixing unit, the pressure member pressurizes the medium as described above, and the peeled portion (that is, the gap) May be adhered again or moved out of the fixing region.

[3-6] Medium In each of the above-described embodiments, the medium is a continuous paper having a band shape, but is not limited thereto. The medium may be a medium cut to a predetermined size such as A4 or B5 (so-called cut paper). Even if such a medium has the first and second sheet members bonded via the adhesive layer as in the medium P1 shown in FIG. 3, the heat applied from the fixing unit 30 is used. The adhesive layer may peel off. Even in that case, the pressure member pressurizes the medium as described above, so that the peeled portion (that is, the gap) may be adhered again or moved out of the fixing region.

[3-7] Image Forming Apparatus In each of the above-described embodiments, the sheet feeding device 2 and the post-processing device 4 respectively supply the medium to the image forming unit 6 and store the medium on which the image is formed. The image forming apparatus may be provided with a unit for supplying a medium and a unit for storing the medium. In this case, the image forming apparatus includes all of the conveying unit, the forming unit, and the fixing device.

  In the above-described embodiment, the image forming apparatus forms a color image by using a plurality of photosensitive drums and a plurality of developing devices arranged along the intermediate transfer belt. What is necessary is just to fix the formed toner image. For example, the image forming apparatus may include a so-called rotary developing device in which the developing device is provided along the circumferential direction of the rotating body, or directly transfers the toner image from the photosensitive drum to the recording medium. The so-called direct transfer system may be used.

[3-8] Fixing Device In each of the above-described embodiments, the fixing device is controlled by the control device 5 included in the image forming apparatus. However, the fixing device itself may function as a computer including the control device. In this case, the fixing unit realizes the determination unit 101 and the control unit 102 shown in FIG. In the case of the determination unit 101, for example, information necessary for determination (such as the arrival time and the departure time described above) is acquired from the control device 5 and the determination is performed.

[3-9] Category of Invention The present invention can be understood as, for example, the above-described fixing device, image forming apparatus, and image forming system. In addition, the present invention can also be understood as a processing method for realizing processing performed by these apparatuses and systems. The processing here is, for example, the pressurization control processing shown in FIG. The present invention can also be understood as a program for causing a computer including a control device such as these devices and system to function as the means shown in FIG. This program may be provided in the form of a recording medium such as an optical disk storing the program, or may be provided in the form of being downloaded to a computer via a network such as the Internet, and making it available for installation. You may do.

DESCRIPTION OF SYMBOLS 1 ... Image forming system, 2 ... Paper feeding apparatus, 3 ... Image forming apparatus, 4 ... Post-processing apparatus, 5 ... Control apparatus, 6 ... Image forming part, 7 ... Fixing apparatus, 101 ... Determination means, 102 ... Control means, DESCRIPTION OF SYMBOLS 20 ... Conveyance roll, 30 ... Fixing part, 40 ... Pressure member, 410 ... 1st rotation member, 420 ... 2nd rotation member, 510, 520 ... Drive member

Claims (10)

Fixing means for applying heat to a toner image formed on a medium having a first sheet member and a second sheet member bonded via an adhesive layer containing an adhesive to fix the toner image to the medium;
A pressure which is provided downstream of the fixing unit in the transport direction in which the medium is transported and approaches the shape before the adhesive layer peeled off by the heat applied by the fixing unit is peeled off. A fixing member that pressurizes the first and second sheet members in a direction in which the first and second sheet members are pressed against the adhesive layer. The pressurizing member is provided such that a line segment represented by a rear end on the upstream side in the transport direction of a portion in contact with the medium is inclined with respect to the width direction of the medium. The fixing device according to claim 1. The pressurizing member is provided such that the line segment is positioned on the downstream side in the transport direction as it approaches the end from the center in the width direction of the medium. The fixing device described. Determining means for determining whether or not the toner image is formed on a portion of the medium that is pressed by the pressure member;
4. The apparatus according to claim 1, further comprising: a control unit that controls the pressure member so as to pressurize the medium when the determination unit determines that the toner image is formed. The fixing device according to claim 1. 5. The control unit according to claim 4, wherein when the determination unit determines that the toner image is not formed, the control unit controls the pressing member so as not to press the medium. Fixing device. When the determination unit determines that the toner image is not formed, the control unit pressurizes the pressurization so as to pressurize at a stronger pressure than when it is determined that the toner image is formed. The fixing device according to claim 4, wherein the member is controlled. The fixing device according to claim 1, wherein the pressure member does not include means for heating the member. The pressure member includes a first rotating member and a second rotating member that form a nip region through which the medium passes. In the nip region, the first rotating member and the second rotating member are deformed and face each other. The fixing device according to claim 1, wherein the surface has a planar shape. The fixing according to claim 8, wherein the first rotating member and the second rotating member rotate at a speed at which the medium passes through the nip region at a speed faster than when the medium passes through the fixing unit. apparatus. A fixing device according to any one of claims 1 to 9,
Conveying means for conveying the medium;
An image forming apparatus comprising: a forming unit that forms a toner image on a medium conveyed by the conveying unit.

Images