Heating device and device for utilizing heated object

Abstract

To provide a heating device equipped with a heating element in which a plurality of heating units differing in calorific power in the width direction that crosses a conveyance direction in which a heated object is conveyed, and a plurality of temperature uniformizing members that are arranged to the heating element, with which it is possible to suppress an unnecessary rise of temperature in a non-passage region of a maximum passage region in which the heated object does not pass through during heating, and to reduce the required time during startup heating of the heating element as well.SOLUTION: A heating device comprises a heating element in which a plurality of heating parts differing in calorific power in the width direction are provided, and a plurality of temperature uniformizing members that are arranged along the width direction by being spaced apart in the conveyance direction of the heating element, and that uniformize the temperature of the heating element in the width direction. One of the plurality of temperature uniformizing members has a length equal to or greater than the width of a maximum passage region of the heating element when a heated object of maximum width is passed through, and the rest of the plurality of temperature uniformizing members has a length shorter than the one of the plurality of temperature uniformizing members.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a heating device and a device for using a heated object.

Background Art

[0002] Patent Document 1 describes a heating and fixing device that has a heating means and a heat-resistant film that can slide while contacting the heating means, and passes a heating area together with the heat-resistant film while bringing a heated material into close contact with the surface of the heat-resistant film on the side opposite to the heating means arrangement side, thereby permanently fixing an unfixed image on the heated material. Patent Document 1 also describes that the heating and fixing device has a temperature rise prevention means for suppressing a temperature rise at the downstream end of the heated material passing direction of the heating means and the support member that supports the heating means.

[0003] Patent Document 2 describes a heating means in which at least one surface of a heat pipe made of a plate-shaped heat pipe has a concave shape, a heating element is printed via an insulating layer on a substrate made of the plate-shaped heat pipe, and the outermost surface is coated with an insulating layer. A heating element is printed via an insulating layer on the surface opposite to the concave-shaped surface, and the uppermost surface is coated with an insulating layer.

[0004] Patent Document 3 describes a fixing device that has a heater having a linear heating element on a substrate, an endless belt having a metal layer and an inner peripheral surface that contacts the heater, and a pressing member that contacts the outer peripheral surface of the endless belt and forms a nip portion that sandwiches and conveys a recording material together with the heater via the endless belt, and heats and fixes an image on the recording material at the nip portion. Patent Document 3 also describes that in the fixing device, there are a contact area that contacts the endless belt and a non-contact area that does not contact the endless belt on the contact surface of the heater with the endless belt, the width of the contact area is narrower than the width of the nip portion in the endless belt rotation direction, and the area of the linear heating element of the heater entirely overlaps the contact area.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 10-232576 (Claim 1, Figure 8, etc.) [Patent Document 2] Japanese Patent Publication No. 2013-142834 (Claim 3, Figure 5, etc.) [Patent Document 3] Japanese Patent Publication No. 2005-149952 (Claim 3, Figure 3, etc.) [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention provides a heating device comprising a heating element having multiple heating sections with different heat generation amounts in the width direction intersecting the conveying direction of the object to be heated, and multiple temperature uniformizing members arranged on the heating element. Compared to a case where multiple temperature uniformizing members, each having a length equal to or greater than the width of the maximum passage area of ​​the heating element when the object to be heated passes through, are arranged in a positional relationship that overlaps with the maximum passage area, the present invention provides a heating device that can suppress unnecessary temperature rise in the non-passing area of ​​the maximum passage area that the object to be heated does not pass through during the heating process, and can reduce the time required for the start-up heating of the heating element. [Means for solving the problem]

[0007] The present invention (1) is, A heating element having multiple heating elements with different heat generation amounts in the width direction intersecting the conveying direction in which the object to be heated is transported, The transport They are spaced apart in the direction and arranged along the width direction, The aforementioned Multiple temperature equalizing members that equalize the temperature of the heating element in the width direction, Equipped with, One of the multiple temperature uniformizing members has a length equal to or greater than the width of the maximum passage area of ​​the heating element when passing the object to be heated with the maximum width through it. The remaining temperature uniformizing members of the plurality of temperature uniformizing members are the Width of the maximum passage area of ​​the heating element It is a heating device with a shorter length than [a certain length].

[0008] The present invention (2) relates to the heating device of the above invention (1), As one of the multiple heating elements, a first heating element is provided, in which the amount of heat generated in the portion of the maximum passage area that does not pass through the object to be heated is relatively high during the heating process. The remaining temperature uniformizing member is a heating device positioned closer to the first heating element than the one temperature uniformizing member.

[0009] The present invention (3) relates to the heating device of the above invention (1), As another heating element in addition to the aforementioned multiple heating elements, a second heating element is provided in which the amount of heat generated during the heating process is relatively higher in the portion of the maximum passage area excluding the non-pass area through which the object to be heated does not pass. The aforementioned one temperature uniformizing member is a heating device positioned closer to the second heating element than the remaining temperature uniformizing members.

[0010] The present invention (4) relates to the heating device of the above invention (2), The remaining temperature uniformizing member is a heating device having a length less than or equal to the width of the region excluding the non-pass region of the maximum passage region.

[0011] The present invention (5) relates to the heating device of the above invention (2), The remaining temperature uniformizing member is a heating device positioned so as not to enter the non-pass region within the maximum pass region.

[0012] The present invention (6) relates to the heating device of the above invention (2), The remaining temperature uniformizing member is a heating device having a length longer than the width of the region excluding the non-pass region of the maximum passage region.

[0013] The present invention (7) relates to the heating device of the above invention (2), The remaining temperature equalization member is a heating device arranged to enter the non-passage area in the maximum passage area.

[0014] Also, the present invention (8) is transport means for transporting the object to be heated, a heating device for heating the object to be heated transported by the transport means, and is provided with a device for using an object to be heated, in which the heating device is constituted by any one of the heating devices of the above inventions (1) to (7).

Advantages of the Invention

[0015] According to the heating device of the above invention (1), when arranging a plurality of temperature equalization members having a length equal to or greater than the width of the maximum passage area of the heating element when passing the object to be heated with the maximum width as a plurality of temperature equalization members in a positional relationship overlapping with the maximum passage area, compared with the case of suppressing unnecessary temperature rise in the non-passage area where the object to be heated does not pass in the maximum passage area during the heat treatment, and the required time during the start-up heating of the heating element can be reduced.

[0016] According to the above invention (2), compared with the case where one temperature equalization member is arranged closer to the first heating part than the remaining temperature equalization members, it becomes easier to suppress unnecessary temperature rise in the non-passage area.

[0017] According to the above invention (3), compared with the case where the remaining temperature equalization members are arranged closer to the second heating part than one temperature equalization member, it becomes easier to reduce the required time during the start-up heating of the heating element.

[0018] According to the above invention (4), compared with the case where the remaining temperature equalization members have a length longer than the width of the area excluding the non-passage area of the maximum passage area, it becomes easier to reduce the required time during the start-up heating of the heating element.

[0019] According to the above invention (5), compared to the case where the remaining temperature uniformizing member is arranged so that it enters the non-pass region in the maximum pass region, the time required for the start-up heating of the heating element can be easily reduced.

[0020] According to the above invention (6), compared to the case where the remaining temperature uniformizing member has a length less than or equal to the width of the region excluding the non-pass region of the maximum pass region, it becomes easier to suppress the unnecessary temperature rise in the non-pass region.

[0021] According to the above invention (7), compared to the case where the remaining temperature uniformizing member is arranged so that it does not enter the non-pass region in the maximum pass region, it becomes easier to suppress unnecessary temperature rise in the non-pass region.

[0022] According to the heated material utilization device of the above invention (8), in the heating device, it is possible to suppress unnecessary temperature rise in the non-passing region of the maximum passage region that the heated material does not pass through during the heating process, and to reduce the time required for the start-up heating of the heating element. [Brief explanation of the drawing]

[0023] [Figure 1] This is a schematic diagram of the image forming apparatus according to Embodiment 1. [Figure 2] This is a schematic cross-sectional view of the heating device according to Embodiment 1. [Figure 3] Figure 2 is a schematic cross-sectional view of a part of the main components of the heating device. [Figure 4] (A) is a schematic cross-sectional view of a part of the heating unit in the heating device shown in Figure 2, and (B) is an exploded view of the heating unit in (A). [Figure 5] This is a schematic diagram of a part of the heating unit. [Figure 6] (A) is a schematic diagram of the heating element in the heating unit, and (B) is a schematic diagram of a heat pipe as an example of a temperature uniformizing member. [Figure 7] (A) is a graph showing the results of a comparative test regarding the time required to start up the heating element, and (B) is a graph showing the results of a comparative test regarding the temperature rise in the non-pass region. [Figure 8] This is a schematic diagram of a part of the heating unit in the heating device according to Embodiment 2. [Figure 9] (A) is a schematic diagram of the heating element in the heating device of Comparative Example 1, and (B) is a schematic diagram of the heating element in the heating device of Comparative Example 2. [Modes for carrying out the invention]

[0024] The embodiments for carrying out the present invention will be described below with reference to the drawings.

[0025] Embodiment 1. Figures 1 and 2 show an example configuration of Embodiment 1 of the present invention. Figure 1 shows an image forming apparatus 1 according to Embodiment 1, and Figure 2 shows a heating apparatus 5 according to Embodiment 1.

[0026] (Image forming apparatus) Image forming apparatus 1 is a device that forms an image by first forming an image on a sheet of paper 9, which is an example of a heated object, using a developer, which is an example of a powder, and then heating it. This image forming apparatus 1 is also an example of a heated object utilization device that utilizes a heated object.

[0027] As shown in Figure 1, the image forming apparatus 1 has a housing 10 with a required external shape, and the image forming apparatus 2, paper feeding apparatus 4, heating apparatus 5, etc. are arranged in the internal space of the housing 10. The dashed line in Figure 1 shows the main transport path when the paper 9 is transported within the housing 10.

[0028] The image-forming device 2 is a device that creates a toner image composed of toner as a developer and transfers it to the paper 9. This image-forming device 2 has a photosensitive drum 21 that rotates in the direction indicated by arrow A, and is configured by arranging equipment such as a charging device 22, an exposure device 23, a developing device 24, a transfer device 25, and a cleaning device 26 around the photosensitive drum 21.

[0029] Of these, the photosensitive drum 21 is an example of an image holder, and is a photoreceptor in the form of a drum having an image-forming surface and a photosensitive layer that serves as the image-holding surface. The charging device 22 is a device that charges the outer surface (image-forming surface) of the photosensitive drum 21 to a required surface potential. This charging device 22 is configured to include a charging member, for example, a roll-shaped member that is in contact with the image-forming surface of the outer surface of the photosensitive drum 21 and to which a charging current is supplied.

[0030] The exposure device 23 is a device that exposes the charged outer surface of the photosensitive drum 21 to image information to form an electrostatic latent image. This exposure device 23 operates by receiving an image signal generated by processing image information input from an external source using image processing means (not shown). Image information refers to information related to the image to be formed, such as characters, figures, photographs, and patterns. The developing device 24 is a device that develops the electrostatic latent image formed on the outer surface of the photosensitive drum 21 with a developer (toner) of a corresponding predetermined color (e.g., black) to reveal it as a monochrome toner image.

[0031] Next, the transfer device 25 is a device that electrostatically transfers the toner image formed on the outer surface of the photosensitive drum 21 to the paper 9. This transfer device 25 is configured to include a transfer member, such as a roll, that contacts the outer surface of the photosensitive drum 21 and to which a transfer current is supplied. The cleaning device 26 is a device that cleans the outer surface of the photosensitive drum 21 by removing unwanted toner, paper dust, and other unwanted materials adhering to the outer surface of the photosensitive drum 21. In the imaging device 2, the area where the photosensitive drum 21 and the transfer device 25 face each other becomes the transfer position TP where the toner image is transferred.

[0032] The paper feeder 4 is a device that receives and feeds the paper 9 to be supplied to the transfer position TP in the imaging device 2. This paper feeder 4 is composed of one or more containers 41 for receiving the paper 9 and one or more feeding devices 43 for feeding the paper 9. The storage unit 41 is a storage member having a stacking plate (not shown) for stacking and storing multiple sheets of paper 9 in the required orientation. The feeding device 43 is a device that feeds out the sheets of paper 9 stacked on the stacking plate of the storage unit 41 one by one using multiple rolls or other devices. The paper feeding device 4 in Embodiment 1 has, for example, two storage units 41A and 41B that can individually store sheets of paper 9A and 9B with different widths during transport, and two feeding devices 43A and 43B that individually feed out the sheets of paper 9A and 9B stored in the storage units 41A and 41B, respectively.

[0033] The paper feed device 4 is connected to the transfer position TP in the imaging device 2 by a paper feed transport path 45, which is an example of a transport means. This paper feed transport path 45 is a paper transport path that transports and supplies the paper 9 (9A or 9B) sent out from the paper feed device 4 to the transfer position TP, and is configured with a plurality of transport roll pairs 46a, 46b that grip and transport the paper 9, and a plurality of guide members (not shown) that secure a transport space for the paper 9 and guide the transport of the paper 9. Furthermore, the paper 9 can be any sheet-like recording medium that can be transported within the housing 10 and is capable of transferring and heat-fixing toner images; there are no particular restrictions on its material, form, etc.

[0034] The heating device 5 is a device that performs heating and pressurizing processes to fix the unfixed toner image transferred at the transfer position TP of the imaging device 2 onto the paper 9. This heating device 5 is constructed by arranging equipment such as a heating rotating body 51 and a pressurizing rotating body 52 in the internal space of a housing 50, which is provided with an inlet 50a and an outlet 50b for the paper 9. Furthermore, in the heating device 5, as shown in Figures 1 and 2, the heating rotating body 51 and the pressurizing rotating body 52 are arranged to rotate in contact with each other, and the paper 9 or the like that passes through the contact area FN is heated and pressurized. Details of this heating device 5 will be described later.

[0035] Then, in this image forming apparatus 1, images are formed, for example, as follows.

[0036] In other words, in the image forming apparatus 1, when a control means (not shown) receives a command to form an image, the image forming apparatus 2 performs necessary operations such as charging, exposure, development, transfer, and cleaning, while the paper feeding apparatus 4 performs a paper feeding operation in which it sends out the required paper 9 (9A or 9B) and transports it through the paper feeding path 45 to the transfer position TP. As a result, a toner image corresponding to the image information is formed on the photosensitive drum 21, while this toner image is transferred to the paper 9 that has been transported from the paper feeder 4 and supplied to the transfer position TP. At this time, the paper 9 on which the toner image has been transferred is detached from the photosensitive drum 21 while sandwiched between the rotating photosensitive drum 21 and the transfer device 25, and then fed towards the heating device 5.

[0037] Next, in the image forming apparatus 1, as shown in Figure 2, the heating device 5 introduces the paper 9 on which the toner image 92 has been transferred to it into the contact area FN between the heating rotating body 51 and the pressurizing rotating body 52, and passes it through. During this passage, a fixing operation is performed in which heating and pressurizing occur. As a result, the unfixed toner image 92 is heated and melted under pressure, fixing it to the paper 9. At this time, the heating rotating body 51 and the pressurizing rotating body 52 function as transport means for transporting the paper 9. After fixing, the paper 9 is discharged from the housing 50 while sandwiched between the heating rotating body 51 and the pressurizing rotating body 52 in the heating device 5, and then transported to the paper discharge port 12 via the paper discharge transport path. As a result, the paper 9 is finally sent by the discharge roll 48 to the paper discharge storage section 13 provided in a part of the housing 10 and stored there.

[0038] With the above steps completed, the basic image forming operation of the image forming apparatus 1, which forms a monochrome image on one side of a single sheet of paper 9, is finished.

[0039] (heating device) Next, we will describe the heating device 5 in detail.

[0040] As shown in Figures 2 and 3, the heating device 5 uses a belt-nip type heating unit 55 as the heating rotating body 51 and a roll type pressure roll 56 as the pressurizing rotating body 52.

[0041] The heating unit 55 is the part that heats the paper 9 at the portion FN (an example of a contact area) that comes into contact with the paper 9 in the width direction D (see Figure 3, etc.) which intersects with the transport direction C of the paper 9. This heating unit 55 is configured as a unit comprising a rotatable heating belt 53, a heating element 54 that generates heat to form a contact portion (nip) FN by pressing the heating belt 53 against the pressurizing rotating body 52 from its inner circumferential surface and thereby heating it, and a plurality of temperature equalization members 7 arranged on the heating element 54 to equalize the temperature in the width direction D of the heating element 54.

[0042] As shown in Figures 3 and 4, the heating unit 55 holds the heating element 54 in contact with the inner surface of the heating belt 53 by the contact holder 61, and the heating belt 53 is rotatably held by a part of the contact holder 61 and the left and right end holders 62A and 62B in Figure 3. Furthermore, the heating unit 55 is supported by a support 63, which holds its contact holder 61 and its left and right end holders 62A and 62B.

[0043] The heating belt 53 is an endless heat-conducting belt that is flexible and heat-resistant. This heating belt 53 is, for example, a belt molded from a synthetic resin such as polyimide or polyamide so that its original shape is cylindrical.

[0044] The heating element 54 is shown in the figure. 5 As shown, the heating element is configured to have a maximum passage area E1 that allows heating of paper 9 usable in the image forming apparatus 1, where the width (width dimension) W in the width direction D intersecting the transport direction C is the maximum width W1. As shown in Figures 4 to 6, the heating element 54 comprises a substrate 541, a plurality of heating elements 542, 543 (two in this example) and a wiring element 545 provided on the substrate 541.

[0045] The substrate 541 is a rectangular plate-shaped member having a length longer than the width of the maximum passage area E1. This substrate 541 is made of an electrically insulating material, for example, a ceramic substrate is used. The side (one side) 541a of the substrate 541 that contacts the inner circumferential surface of the heating belt 53 is covered by a coating layer formed after the heating elements 542 and 543 are provided.

[0046] As shown in Figure 6(A), the heating elements 542 and 543 are resistance heating wires provided in a straight line on one side 541a of the substrate 541, along its longitudinal direction (the direction along the width direction D of the paper 9) and at intervals, approximately parallel to the paper transport direction C of the paper 9. Furthermore, the heat-generating sections 542 and 543 are configured such that the amount of heat generated in the width direction D of the paper 9, which is also the longitudinal direction of the substrate 541, is relatively different.

[0047] The heating element 542 is configured as a first heating element in which the amount of heat generated is relatively highest in the portion 542a corresponding to the non-passing regions E2 and E3 of the maximum passing region E1 through which the paper 9 does not pass. In the heating device 5, the non-passing regions E2 and E3 are located at both ends in the width direction D of the maximum passing region E1, because the heating device 5 employs a central reference conveying system (center register system). The central reference transport method is a method of transporting paper 9 by guiding it so that the central position in the width direction D of the paper 9 during transport approximately coincides with the central reference position (central reference line) CL in the width direction D of the maximum passage area E1 of the paper 9 in the contact portion FN of the heating device 5.

[0048] The heat-generating section 543 is configured as a second heat-generating section in which the amount of heat generated is relatively highest in the portion 543a corresponding to the region E4 (normal passage region) of the maximum passage region E1 excluding the non-passing regions E2 and E3. The area E4, excluding the non-passing areas E2 and E3, corresponds to the width W2 of paper 9 that is narrower than the maximum width W1 and is pre-selected as frequently used. For this reason, in the image forming apparatus 1 or heating apparatus 5, for example, paper 9 with a width narrower than width W2 during transport may be used.

[0049] Heat generation from heating elements 542 and 543 of The relatively higher portions 542a and 543a are achieved, for example, by making at least one of the width and thickness of the resistive heating wire portion narrower or thinner than the other portion (the heat-suppressing portions 542b and 543b), or both, so that the electrical resistance value becomes relatively higher. In Embodiment 1, the first heating element 542 is configured to generate heat such that the amount of heat generated in the portion 542b corresponding to region E4, excluding the non-passing regions E2 and E3, is less than half the amount of heat generated in the portion 542a corresponding to the non-passing regions E2 and E3. Furthermore, the second heating element 543 in Embodiment 1 corresponds to the non-pass-through regions E2 and E3, part 54 3 The configuration is such that the amount of heat generated in b is less than half the amount of heat generated in portion 543a, which corresponds to region E4 excluding the non-pass-through regions E2 and E3.

[0050] The wiring section 545 is the part used as the ground wire when supplying power. As shown in Figure 6(A), the heating elements 542 and 543 are wired and connected to the respective power supply terminals of the power supply connection section 57, and are powered via the power supply connection section 57. In addition, the heating elements 542 and 543 are connected to the wiring section 545 from the end opposite to the end on which the power supply connection section 57 is located. The wiring section 545 is wired and connected to a dedicated terminal of the power supply connection section 57.

[0051] The heating element 54 is used to heat both the first heating section 542 and the second heating section 543 when heating paper 9 with a maximum width W1. It is also used to heat only the first heating section 542 when heating paper 9 with a width W2 or less, corresponding to the area E4 excluding the non-pass-through areas E2 and E3.

[0052] Furthermore, the heating element 54's temperature during heating is measured by a temperature sensor 58 positioned to contact a necessary location on the back surface 541b of the substrate 541 shown in Figure 4. The information measured by the temperature sensor 58 is then fed back to a heating control unit (not shown) to control the on / off operation of the heating units 542 and 543.

[0053] As shown in Figure 5, the power supply connection section 57 is located at the end of the substrate 541 that extends from one end to, for example, the right end holder 62B in Figure 5. The power supply connection section 57 is also connected to a power source connection section 14, which extends from a power supply section (not shown) in the image forming apparatus 1 or heating apparatus 5, and becomes energized.

[0054] As shown in Figure 4, the contact holder 61 is a plate-shaped member that is long in one direction and has a receiving recess 61a on one side that contacts the inner circumferential surface of the heating belt 53 for housing and holding the heating element 54. Furthermore, the contact holder 61 is provided with mounting grooves 61b and mounting contacts 61c on one side and the other side opposite it, which are used when attaching it to the support 63. Furthermore, the contact holder 61 has a long edge end on one side of which a receiving recess 61a is provided, which is formed as an introduction guide portion 61d consisting of a curved surface that guides the heating belt 53 to be introduced into the contact portion FN. The other long edge end on the other side of the contact holder 61 has a curved surface that guides the heating belt 53 in a direction away from the contact portion FN, which is formed as an exit guide portion 61e.

[0055] Both the left and right end holders 62A and 62B are components with guide and holding portions 622 on the inner surface of a disc-shaped body 621, with a portion of the disc facing the pressure roll 56 missing, as shown in Figures 2 and 3. The guide and holding portions 622 are curved parts that guide and hold both ends of the heating belt 53 in the width direction so that they can rotate from their inner circumferential surface. In addition, the left and right end holders 62A and 62B are provided with mounting recesses (not shown) on the inside of the guide and holding portions 622 of their body 621, which are fitted onto the ends of the support 63 for attachment.

[0056] As shown in Figure 3, the support 63 is a member that is longer than the longitudinal length of the heating element 54. As the support 63, as shown in Figure 4(A), for example, a member in the form of a long plate with the long side end bent at approximately a right angle in the same direction so that the cross-section becomes concave is applied. When attaching the support 63 to the contact holder 61, as shown in Figure 4(B), one bent end 63b is fitted into the mounting groove 61b of the contact holder 61, while the other bent end 63c is kept in contact with the mounting contact portion 61c of the contact holder 61. In this way, the support 63 supports a portion of the contact holder 61 by sandwiching it along its longitudinal direction.

[0057] Multiple temperature equalization members 7 are positioned in contact with the surface (back surface) 541b of the substrate 541 of the heating element 54, opposite to the surface 541a that contacts the heating belt 53.

[0058] As shown in Figures 4 to 6, the multiple temperature uniformizing members 7 are arranged such that one of them, the temperature uniformizing member 7A, has a length L1 that is equal to or greater than the width of the maximum passage area E1 of the heating element 54 when a sheet of paper 9 with a maximum width W1 passes through it. Furthermore, among the multiple temperature uniformizing members 7, the remaining temperature uniformizing member 7B is a temperature uniformizing member having a shorter length L2 than the single temperature uniformizing member 7A. Here, the length of the multiple temperature uniformizing members 7 is their length in the longitudinal direction. ru.

[0059] In Embodiment 1, a heat pipe 71 is used as one temperature uniformizing member 7A, and a heat pipe 72 is used as the remaining temperature uniformizing member 7B. Both heat pipes 71 and 72 are sealed tubes with both ends closed, made of a material with excellent thermal conductivity such as copper or stainless steel, and have a body with a capillary structure (so-called wick) on its inner wall, with a volatile working fluid (for example, pure water) sealed inside the body.

[0060] The heat pipe 71 has a length L1 that is greater than or equal to the width of the maximum passage region E1 of the heating element 54. In Embodiment 1, the heat pipe 71 has a length L1 (>E1) that is greater than the width of the maximum passage region E1. Furthermore, as shown in Figure 5, the heat pipe 71 is positioned closer to the second heat-generating section 543 of the heating element 54 than the heat pipe 72. Furthermore, as shown in Figure 5, the heat pipe 71 is positioned in a location that overlaps with the maximum heat passage area E1 of the heat-generating element 54. So In other words, the heat pipe 71 is positioned such that both its one end 71b and its other end 71c are located outside the ends of the maximum passage region E1.

[0061] Since the heat pipe 72 only needs to be shorter than the heat pipe 71, the length L2 of the heat pipe 72 must be at least shorter than the width of the maximum passage area E1 of the heat element 54. <E1)であればよい。 However, in Embodiment 1, the heat pipe 72 has a length L2 that is less than or equal to the width of region E4, which is the maximum passage region E1 of the heating element 54 excluding the non-passing regions E2 and E3. In practice, the length L2 is shorter than the width of region E4.

[0062] Furthermore, as shown in Figure 5, the heat pipe 72 is positioned closer to the first heat-generating section 542 of the heating element 54 than the heat pipe 71. Furthermore, as shown in Figure 5, the heat pipe 72 is positioned so that it does not enter the non-passing regions E2 and E3 within the maximum passing region E1. In other words, in this configuration, both one end 72b and the other end 72c of the heat pipe 72 are located within region E4, which is outside the non-passing regions E2 and E3 of the maximum passing region E1.

[0063] Furthermore, the heat pipes 71 and 72 are arranged on the back surface 541b of the substrate 541 of the heating element 54, along the longitudinal direction (along the width direction D of the paper 9), and parallel to the paper transport direction C with the required spacing between them. In this configuration, the heat pipes 71 and 72 are used in a parallel arrangement, and therefore relatively small diameter pipes (for example, with an outer diameter of a few millimeters) are used.

[0064] Furthermore, the heat pipes 71 and 72 are mounted in the heating unit 55 as follows. Specifically, as shown in Figure 4, the heat pipes 71 and 72 are housed in mounting grooves 65A and 65B provided in the housing recess 61a of the contact holder 61. Then, the heating element 54 is fitted into the housing recess 61a. As a result, the heat pipes 71 and 72 are mounted while being pressed against the back surface 541b of the heating element 54. In this case, the heat pipes 71 and 72 may be partially bonded and fixed to the back surface 541b of the heating element 54 with a thermally conductive adhesive.

[0065] As shown in Figure 3, the heating unit 55 is fixed by attaching both ends 63d and 63e of the support 63 in the longitudinal direction to mounting parts (not shown) provided on the inner wall surface of the housing 50 of the heating device 5. In this way, the heating unit 55 is mounted on the heating device 5.

[0066] The pressure roll 56, which serves as the rotating body 52 for pressurization, may be, for example, a cylindrical roll base made of metal or the like, with an elastic layer and a release layer provided on its outer surface. As shown in Figure 3, the pressure roll 56 is rotatably supported at both axial ends 56c and 56d relative to a pressure mechanism (not shown) located in the housing 50. The pressure roll 56 is also subjected to pressure from the pressure mechanism, which presses it against the heating unit 55.

[0067] As a result, the pressure roll 56 is kept in a state in which its outer surface is pressed against one side 541a of the heating element 54 with the required pressure over the longitudinal direction via the heating belt 53 in the heating unit 55, as shown in Figures 2 and 3. The portion of this pressure roll 56 that presses against the heating unit 55 via the heating belt 53 is the contact portion FN described above.

[0068] Furthermore, as shown in Figure 3, a powered passive gear 59, which is an example of a drive input means, is attached to one of the shaft portions 56c of the pressure roll 56. This powered passive gear 59 meshes with a powered passive gear (not shown) in a drive transmission device 15 located on the housing 10 side of the image forming apparatus 1.

[0069] As a result, when it is time for necessary operations such as image formation, the pressure roll 56 is driven to rotate at the required speed in the direction indicated by arrow B1, as rotational power is transmitted and input from the drive transmission device 15, as shown in Figure 2. When the pressure roll 56 rotates and is driven, the heating belt 53 in the heating unit 55 rotates in the direction indicated by arrow B2, as shown in Figure 2.

[0070] (Heating operation of the heating device) When the power is turned on or the heating device 5 is in use, both the first heating element 542 and the second heating element 543 of the heating element 54 are supplied with power. As a result, the heating device 5 starts a startup operation in which it generates heat in the first heating section 542 and the second heating section 543 until the temperature in the width direction D of the maximum passage area E1 of the heating element 54 reaches the required set temperature.

[0071] Furthermore, when the heating device 5 performs heating during the image forming operation, it adjusts the area of ​​the heating element 54 of the heating unit 55 to be heated according to the difference in width W of the paper 9 passing through the contact area FN, and performs the heating process. In Embodiment 1, the heating process becomes the fixing operation.

[0072] For example, when passing a sheet of paper 9 with a maximum width W1 during transport, power is supplied to both the first heating element 542 and the second heating element 543 of the heating element 54 to heat the maximum passage area E1 of the paper 9 corresponding to the maximum width W1 of the paper 9 in the heating element 54. As a result, the heating device 5 heats the portion of the heating belt 53 corresponding to the maximum passage area E1 via the heating element 54 at this time, thereby heating the paper 9 with the maximum width W1.

[0073] When passing a paper 9 with a narrower width W2, which is frequently used, power is supplied only to the second heating element 543 of the heating element 54, causing the area of ​​the heating element 54 corresponding to the width W2 of the paper 9 (area E4 excluding the non-passing areas E2 and E3) to heat up. As a result, the heating device 5 heats the portion of the heating belt 53 corresponding to area E4 excluding the non-passing areas E2 and E3 via the heating element 54, thereby heating the paper 9 with a width of W2.

[0074] Incidentally, when the paper 9 with a width of W2 passes through the heating element 54, power is supplied only to the second heating element 543 to generate heat, but the first heating element 542 also heats up to some extent the portion 543b corresponding to the non-passing regions E2 and E3 of the first heating element 542. In this way, the heating device 5 efficiently generates heat by adjusting the heating element 54 of the heating unit 55 to match the difference in the width W of the paper 9, thereby performing the heating process.

[0075] (Unwanted temperature rise in non-pass regions) Furthermore, in this heating device 5, for example, when heating by continuously passing a sheet of paper 9 with a width W2 narrower than the maximum width W1, regions E2 and E3 are created within the contact area FN that the paper 9 does not pass through. Therefore, in the non-pass regions E2 and E3 of the heating element 54 located in the contact area FN, heat is not lost by the passing paper 9, and the heating continues from the heat-suppressed portion 542a of the first heating element 542, thus the temperature but Unnecessary to It can sometimes reach an elevated state.

[0076] In contrast, in the heating device 5, the heat transfer action of the heat pipe 71, which is located in the maximum passage region E1 including the non-passing regions E2 and E3, causes the heat generated by the temperature rise in the non-passing regions E2 and E3 of the heating element 54 to be transferred to the region of the heating element 54 through which the paper 9 passes (region E4, excluding the non-passing regions E2 and E3). In other words, at this time, the region of the heating element 54 through which the paper 9 passes temporarily loses heat as the paper 9 passes, becoming colder than the non-passing regions E2 and E3, and thus the heat from the non-passing regions E2 and E3 is transferred by the heat pipe 71.

[0077] As a result, in the heating device 5, the temperature rise in the non-pass-through regions E2 and E3 is suppressed compared to when the temperature uniformizing member is not placed. In addition, in the heating device 5, the heat pipe 71 is placed close to the second heating element 543, which makes it easier to suppress the temperature rise in the non-pass-through regions E2 and E3. Furthermore, this allows the heating element 54 to achieve uniform temperature distribution in the width direction D of the maximum passage region E1, particularly through the arrangement of the heat pipes 71.

[0078] (Time required for the heating element to start up) Furthermore, when the heating device 5 is powered on or when the heating operation is restarted, the time required for the start-up heating is reduced compared to when multiple temperature uniformizing members 7A, each having a length equal to or greater than the width of the maximum passage area E1 of the heating element 54, are arranged in a positional relationship that overlaps with the maximum passage area E1. This is presumed to be because, instead of arranging two heat pipes 71 having a length equal to or greater than the width of the maximum passage region E1, one heat pipe 72 having a shorter length than the heat pipe 71 was placed in its place, resulting in a decrease in the heat capacity of the heat pipe 72 that is in contact with the heat-generating element 54.

[0079] (Comparative study) A comparative test was conducted using the heating device 5 according to Embodiment 1 (Example 1) and the heating devices of the following Comparative Examples 1 and 2. The comparative test investigated the temperature fluctuations of the non-passing regions E2 and E3 in the heating element 54 (contact portion FN) of each heating device, and the time required for the start-up heating of the heating element 54 of each heating device. The results at this time are shown in a simplified form in Figure 7.

[0080] The heating device in Comparative Example 1 used the heating element 540A shown in Figure 9(A). In the heating element 540A, instead of the heat pipe 72 of the temperature uniformizing member 7B placed in the heating element 54 in Embodiment 1, a heat pipe 71 as a temperature uniformizing member 7A having a length equal to or greater than the width of the maximum passage region E1 is placed close to the first heating section 542. Furthermore, both heat pipes 71, 71 in the heating element 540A are positioned in a positional relationship that overlaps with the maximum passage region E1.

[0081] The heating device in Comparative Example 2 used the heating element 540B shown in Figure 9(B). In the heating element 540B, instead of the heat pipe 71 of the temperature uniformizing member 7A placed in the heating element 54 in Embodiment 1, a heat pipe 72 acting as a temperature uniformizing member 7B is placed close to the second heating element 543. The heat pipe 72 has a length shorter than the width of the maximum passage region E1 and slightly shorter than the width of the region E4 excluding the non-passing regions E2 and E3. Furthermore, both heat pipes 72, 72 in the heating element 540B are positioned so that they do not enter the non-passing regions E2 and E3 within the maximum passage region E1.

[0082] As shown in Figure 7(A), the time T1 required for the heating element 54 of Example 1 to reach the target temperature during startup heating is slightly longer than the time required for the heating device of Comparative Example 2, but shorter than the time T2 (>T1) required for the heating device of Comparative Example 1. This indicates that the heating device 5 of Example 1 can reduce the target temperature during startup of the heating element 54 compared to the heating device of Comparative Example 1.

[0083] As shown in Figure 7(B), the heating device 5 of Example 1 suppresses the temperature rise in the non-pass regions E2 and E3 to a slightly lesser degree than the heating device of Comparative Example 1, but it keeps the temperature below the target temperature in the non-pass regions compared to the heating device of Comparative Example 2. This indicates that the heating device 5 of Example 1 is able to suppress the unwanted temperature rise in the non-pass regions E2 and E3 of the heating element 54 more effectively than the heating device of Comparative Example 2.

[0084] Embodiment 2. Figure 8 shows a part (mainly the heating element) of the heating device 5B according to Embodiment 2 of the present invention. The heating device 5B according to Embodiment 2 differs in that it uses a heating element 54B which has heat pipes 73 of different lengths instead of the heat pipe 72 which serves as a temperature uniformizing member 7B arranged in the heating element 54 in Embodiment 1, but otherwise has the same configuration as the heating device 5 according to Embodiment 1. Therefore, in the following explanation and in Figure 8, the same reference numerals are used for components common to the heating element 54 in Embodiment 1, and their descriptions are omitted unless necessary.

[0085] As shown in Figure 8, the heating element 54B in the heating device 5B includes a heat pipe 73 as a temperature uniformizing member 7B, in addition to a heat pipe 71 as a temperature uniformizing member 7A.

[0086] The heat pipe 73 has a length shorter than the width of the maximum passage region E1, but as shown in Figure 8, it has a length L3 longer than the width of region E4, which is the maximum passage region E1 excluding the non-passing regions E2 and E3. Furthermore, the heat pipe 73 is similar to the heat pipe 72 in Embodiment 1, The first heat-generating section 542 of the heating element 54B is positioned closer to the heat pipe 71 than the heat pipe 71.

[0087] Furthermore, the heat pipe 73 is positioned so that it enters the non-passing regions E2 and E3 in the maximum passing region E1. In other words, in this case, both the one end 73b and the other end 73c of the heat pipe 73 are positioned so that they extend from region E4, which is outside the non-passing regions E2 and E3, into the non-passing regions E2 and E3. In this case, the length of the portion of the heat pipe 73 that enters the non-passing regions E2 and E3 is preferably less than or equal to half the width of the non-passing regions E2 and E3, for example, to make it easier to reduce the time required during startup heating.

[0088] Furthermore, the heating device 5B according to Embodiment 2 performs the same heating operation as the heating device 5 according to Embodiment 1.

[0089] Furthermore, using the heating device 5B according to Embodiment 2 (Example 2), the temperature fluctuations of the non-pass regions E2 and E3 in the heating element 54B and the time required for the start-up heating of the heating element 54B were investigated, similar to the comparative test described above. The results of this Example 2 are also shown in Figure 7.

[0090] With this heating device 5B, compared to the case where multiple temperature uniformizing members 7A having a length equal to or greater than the width of the maximum passage region E1 of the heating element 54 are arranged in a positional relationship that overlaps with the maximum passage region E1, similar to the case of the heating device 5 according to Embodiment 1, unnecessary temperature rise in the non-passing regions E2 and E3 of the maximum passage region E1 is suppressed during the heating process, and the time required for the start-up heating of the heating element 54B is reduced. In particular, the heating device 5B makes it easier to suppress unnecessary temperature rises in the non-pass-through regions E2 and E3 compared to the heating device 5 according to Embodiment 1.

[0091] Variant expression. The present invention is not limited to the configuration examples illustrated in each of the above embodiments, and necessary modifications and combinations may be made as long as they do not alter the gist of the invention as described in the claims. The present invention also includes, for example, the following modifications.

[0092] The heating elements 54 and 54B may be configured with three or more heating elements. If three or more heating elements are used, one of the heating elements shall be a first heating element configured to generate relatively high heat in the portion corresponding to the non-passing regions E2 and E3 within the maximum passage region E1. Another heating element shall be a second heating element configured to generate relatively high heat in the portion corresponding to region E4 within the maximum passage region E1, excluding the non-passing regions E2 and E3. Furthermore, other heat-generating elements besides these two can be configured as a third heat-generating element, where the heat generation in a narrower area is relatively higher than that of the second heat-generating element, or a fourth heat-generating element, where the heat generation in a wider area is relatively higher than that of the second heat-generating element.

[0093] Regarding the temperature uniformizing member 7, if the heating elements 54, 54B are heating elements with three or more heating elements, two members may be provided, but three or more temperature uniformizing members 7 may also be provided. When three or more temperature uniformizing members 7 are arranged, it is preferable that one of them be a temperature uniformizing member 7A with a width equal to or greater than the width of the maximum passage area E1, and that the other temperature uniformizing members 7B have a shorter length than temperature uniformizing member 7A. Even in this case, temperature uniformizing member 7A is arranged close to the second heat-generating section. However, even in this case, multiple temperature uniformizing members 7A may be used. However, even when using multiple temperature uniformizing members 7A, it is preferable to use fewer of them than the number of temperature uniformizing members 7B.

[0094] In addition to a heat pipe, a vapor chamber, graphite sheet, copper, or the like may be used as the temperature uniformizing member 7. Furthermore, the heat pipes 71, 72, and 73 are not limited to cylindrical shapes, but may also be, for example, flattened plate shapes.

[0095] The heating devices 5 and 5B according to Embodiments 1 and 2 were configured such that a heating unit 55, which is an example of a heating rotating body 51, and a pressure roll 56, which is an example of a pressurizing rotating body 52, are in contact with each other and rotate in a nearly horizontal position, but the device is not limited to this configuration. In other words, the heating device 5 may be configured such that, for example, the heating unit 55 and the pressure roll 56 are positioned vertically (in the direction of gravity) and brought into contact and rotated, or the heating unit 55 and the pressure roll 56 are positioned vertically in an obliquely inclined direction and brought into contact and rotated. Furthermore, the pressurizing rotating body 52 is not limited to a roll type; for example, a belt-nip type may also be used. The drive input means for the pressurizing rotating body 52 is not limited to a powered passive gear 59; other types may also be used.

[0096] Furthermore, the heating devices 5 and 5B are, so to speak, heating and pressurizing devices equipped with a pressurizing rotating body 52, but they do not need to be equipped with a pressurizing rotating body 52 as long as they can move the object to be heated so that it comes into contact with the heating part of the heating unit 55 and is heated. The object to be heated by the heating devices 5,5B is not limited to the paper 9.

[0097] Furthermore, the heating unit 55 may also treat the heating belt 53 as an example or part of the object to be heated. Moreover, the heating unit 55 may have a configuration that does not include the heating belt 53.

[0098] Furthermore, while embodiments 1 and 2 show examples in which the heating device 5 is applied to the image forming apparatus 1, the invention is not limited to these examples. In other words, the heating device 5 can also be applied to other image forming devices, paper drying devices that heat or dry paper 9 transported by paper transport means (an example of a device using a heated material), and devices that have a process of heating or drying a sheet-like material (an example of a heated material) that does not form an image while being transported by transport means (an example of a device using a heated material). Furthermore, the image forming apparatus 1 may be an apparatus that forms a multi-color image by combining multiple toners, and there are no particular limitations on its form or other specifications. [Explanation of Symbols]

[0099] 1. Image forming apparatus (an example of an apparatus that utilizes a heated object) 5,5B…Heating device 7 ... Temperature homogenizing material 7A…One temperature uniformizing component 7B... Remaining temperature equalization components 9. Paper (an example of an object to be heated) 542...First heating element (an example of a heating element) 543...Second heating element (an example of a heating element) 71… Heat pipe (an example of a temperature uniformizing component) 72, 73… Heat pipes (an example of the remaining temperature equalization components) C ... Conveying direction D…Width direction E1…Maximum passing area E2,E3…non-passing area E4…The area of ​​the maximum pass-through region excluding the non-pass-through region. L...length

Claims

1. A heating element having multiple heating elements with different heat output in the width direction intersecting the conveying direction in which the object to be heated is transported, A plurality of temperature equalizing members are arranged at intervals in the transport direction and along the width direction to equalize the temperature of the heating element in the width direction, Equipped with, One of the multiple temperature uniformizing members has a length equal to or greater than the width of the maximum passage area of ​​the heating element when the object to be heated with the maximum width passes through it. The heating device wherein the remaining temperature uniformizing members of the plurality of temperature uniformizing members have a length shorter than the width of the maximum passage area of ​​the heating element.

2. As one of the multiple heating elements, a first heating element is provided, in which the amount of heat generated in the portion of the maximum passage area that does not pass through the object to be heated is relatively high during the heating process. The heating device according to claim 1, wherein the remaining temperature uniformizing member is positioned closer to the first heating element than the one temperature uniformizing member.

3. As another heating element in addition to the aforementioned multiple heating elements, a second heating element is provided in which the amount of heat generated during the heating process is relatively higher in the portion of the maximum passage area excluding the non-passing area through which the object to be heated does not pass. The heating device according to claim 1, wherein the one temperature uniformizing member is positioned closer to the second heating element than the remaining temperature uniformizing members.

4. The heating device according to claim 2, wherein the remaining temperature uniformizing member has a length less than or equal to the width of the region excluding the non-pass region of the maximum passage region.

5. The heating device according to claim 2, wherein the remaining temperature uniformizing member is arranged so as not to enter the non-pass region in the maximum pass region.

6. The heating device according to claim 2, wherein the remaining temperature uniformizing member has a length longer than the width of the region excluding the non-pass region of the maximum passage region.

7. The heating device according to claim 2, wherein the remaining temperature uniformizing member is arranged to enter the non-pass region in the maximum pass region.

8. A conveying means for transporting the object to be heated, A heating device for heating the object to be heated, which is transported by the transport means, Equipped with, A device for utilizing a heated object, wherein the heating device is the heating device described in any one of claims 1 to 7.

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