Recording material cooling device

Abstract

To provide a recording material cooling device that can prevent electrification of a belt.SOLUTION: A static eliminating needle 600 is in contact with an outer peripheral surface of a rotating first belt 501 to prevent electrification of the first belt 501. A static eliminating needle 601 is in contact with an outer peripheral surface of a rotating second belt 502 to prevent electrification of the second belt 502. In this way, since the static eliminating needle 600 and the static eliminating needle 601 are in direct contact with the outer peripheral surface of the first belt 501 and the outer peripheral surface of the second belt 502, respectively, and are always in contact with the rotating first belt 501 and the rotating second belt 502, electrification of the first belt 501 and the second belt 502 can be effectively prevented.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a recording material cooling device that cools a recording material via a belt. [Background technology]

[0002] In an image forming apparatus, a toner image formed on a recording material is heated and pressurized by a fixing device to fix the toner image to the recording material. Therefore, the temperature of the recording material conveyed from the fixing device becomes higher than that before fixing. If the recording material after the toner image is fixed is discharged and stacked on an output tray while still at a high temperature, there is a risk that the stacked recording materials will stick to each other due to the toner. In order to prevent such sticking of the recording material, a recording material cooling device is provided that lowers the temperature of the recording material after the toner image is fixed (Patent Document 1). The recording material cooling device described in Patent Document 1 is a belt cooling type device, in which one of a pair of belts that sandwich and convey the recording material that has passed through the fixing device is cooled by a heat sink, and the temperature of the recording material is lowered via the cooled belt. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2009-181055 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned recording material cooling device, the belt cooled by the heat sink becomes charged due to friction with the heat sink, or the pair of rotating belts become charged due to contact with each other. However, if the belt remains charged, there is a risk that the recording material whose temperature has been lowered through the belt will be discharged in a curled state, or that the recording material will get stuck in the belt, causing a so-called jam.

[0005] SUMMARY OF THE PRESENT DISCLOSURE In view of the above problems, an object of the present invention is to provide a recording material cooling device capable of suppressing charging of a belt. [Means for solving the problem]

[0006] A recording material cooling device according to an embodiment of the present invention includes: Equipped with a fixing device It is attached to the main body of the image forming apparatus, The fixing device a cooling member for cooling a recording material on which a toner image has been fixed by a toner fixing device, the cooling member comprising: an endless belt that contacts a toner image forming surface of the recording material when an image is formed on one side of the recording material; a plurality of rollers that stretch the belt; a cooling member that contacts an inner peripheral surface of the belt to cool the belt; a transport unit that forms a first nip portion together with the belt and transports the recording material; and a charge suppressing member that contacts an outer peripheral surface of the belt and suppresses charging of the belt. A pair of side plates supporting the plurality of rollers; and a connecting member connecting the pair of side plates. Equipped with the static electricity suppressing member is provided on the connecting member, It is characterized by: Effect of the Invention

[0007] According to the present invention, the charge suppressing member in contact with the outer circumferential surface of the belt can effectively suppress the charge buildup on the belt. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram illustrating a configuration of an image forming apparatus. [Diagram 2] FIG. 2 is a schematic diagram showing a recording material cooling device according to the embodiment. [Diagram 3] FIG. 4 is a perspective view showing the recording material cooling device when the first unit is in the contact position. [Figure 4] FIG. 4 is a perspective view showing the recording material cooling device when the first unit is in the separated position. [Diagram 5] FIG. 4 is an exploded perspective view for explaining a pressure release lever. [Figure 6] FIG. 4 is an enlarged view for explaining a static eliminator needle. [Figure 7] FIG. 4 is a perspective view showing the recording material cooling device as viewed from the rear support plate side. [Figure 8] FIG. [Figure 9]11A and 11B are diagrams for explaining roller adjustment by the adjustment mechanism, in which (a) the adjustment plate is rotated in the J direction for adjustment, (b) the adjustment plate is rotated in the M direction for adjustment, and (c) after adjustment. [Figure 10] FIG. 1 is a schematic diagram showing an image forming system in which a recording material cooling device is provided outside an image forming apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <Image forming device> The recording material cooling device of this embodiment will be described below. First, a schematic configuration of an image forming apparatus suitable for using the recording material cooling device of this embodiment will be described with reference to FIG. 1. The image forming apparatus 100 shown in FIG. 1 is a tandem-type full-color printer of an electrophotographic system. The image forming apparatus 100 has image forming units Pa, Pb, Pc, and Pd that form images of yellow, magenta, cyan, and black, respectively. The image forming apparatus 100 forms a toner image on a recording material S in response to image information from a document reading device (not shown) connected to the apparatus main body 100A or an external device (not shown) such as a personal computer connected to the apparatus main body 100A in a communicable manner. Examples of the recording material S include various types of sheet materials such as plain paper, thick paper, rough paper, textured paper, coated paper, plastic film, and cloth. In this embodiment, the image forming sections Pa to Pd, primary transfer rollers 6a to 6d, intermediate transfer belt 80, secondary transfer inner roller 14, secondary transfer outer roller 11, and tension rollers 15 and 16 constitute an image forming unit 200 that forms a toner image on recording material S.

[0010] The conveying process of the recording material S of the image forming apparatus 100 will be described. The recording material S is stored in a stacked form in a paper feed cassette 10, and is sent out from the paper feed cassette 10 by a paper feed roller 13 in accordance with the image formation timing. The recording material S sent out by the paper feed roller 13 is conveyed to a registration roller 12 arranged in the middle of a conveying path 114. Then, after the registration roller 12 performs skew correction and timing correction on the recording material S, the recording material S is sent to a secondary transfer portion T2. ​​The secondary transfer portion T2 is a transfer nip portion formed by a secondary transfer inner roller 14 and a secondary transfer outer roller 11, and a toner image is transferred onto the recording material in response to the application of a secondary transfer voltage to the secondary transfer outer roller 11.

[0011] The process of forming an image sent to the secondary transfer portion T2 at the same timing as the process of conveying the recording material S to the secondary transfer portion T2 described above will be described. First, the image forming portions will be described. The image forming portions Pa, Pb, Pc, and Pd for each color are configured almost the same except that the toner colors used in the developing devices 1a, 1b, 1c, and 1d are different, that is, yellow, magenta, cyan, and black. Therefore, the following description will be given of the black image forming portion Pd as a representative, and the description of the other image forming portions Pa, Pb, and Pc will be omitted.

[0012] The image forming section Pd is mainly composed of a developing device 1d, a charging device 2d, a photosensitive drum 3d, a photosensitive drum cleaner 4d, and an exposure device 5d. The surface of the photosensitive drum 3d, which is rotated in the direction of the arrow R1, is uniformly charged in advance by the charging device 2d, and then an electrostatic latent image is formed on the surface of the photosensitive drum 3d by the exposure device 5d, which is driven based on a signal of image information. Next, the electrostatic latent image formed on the photosensitive drum 3d is developed into a toner image by the developing device 1d using a developer. Then, the toner image formed on the photosensitive drum 3d is primarily transferred onto the intermediate transfer belt 80 in response to the application of a primary transfer voltage to a primary transfer roller 6d, which is disposed with the image forming section Pd and the intermediate transfer belt 80 sandwiched therebetween. A small amount of primary transfer residual toner remaining on the photosensitive drum 3d is collected by the photosensitive drum cleaner 4d.

[0013] The intermediate transfer belt 80 is stretched by the inner secondary transfer roller 14 and tension rollers 15 and 16, and driven in the direction of the arrow R2. In this embodiment, the tension roller 16 also serves as a drive roller for driving the intermediate transfer belt 80. The image forming processes for each color, which are processed in parallel by the image forming units Pa to Pd, are performed at a timing when the image is sequentially superimposed on the toner image of the upstream color that has been primarily transferred onto the intermediate transfer belt 80. As a result, a full-color toner image is finally formed on the intermediate transfer belt 80, and is conveyed to the secondary transfer unit T2. Note that the secondary transfer residual toner after passing through the secondary transfer unit T2 is removed from the intermediate transfer belt 80 by the belt cleaner 22.

[0014] As described above, the timing of the recording material S and the full-color toner image coincides at the secondary transfer portion T2 through the conveying process and the image forming process, and the secondary transfer is performed. After that, the recording material S is conveyed to the fixing device 30, where a predetermined pressure and heat are applied to fix the toner image on the recording material. The fixing device 30 pinches and conveys the recording material S on which the toner image has been formed, and heats and presses the conveyed recording material S to fix the toner image on the recording material S. The fixing device 30 has a heating roller 301 (heating rotatable body) that heats the recording material S, and a pressure roller 302 (pressure rotatable body) that contacts the heating roller 301 and forms a fixing nip portion (second nip) that heats and presses the recording material S while pinching and conveying it. The toner of the toner image formed on the recording material S is melted and mixed by the heating and pressure, and is fixed on the recording material S as a full-color image. In this way, a series of image forming processes is completed. In the case of this embodiment, the recording material S on which the toner image has been fixed is conveyed from the fixing device 30 to the recording material cooling device 50 and cooled. For example, the temperature of the recording material S is about 90° C. immediately before the recording material cooling device 50, but is reduced to about 60° C. after passing through the recording material cooling device 50.

[0015] In the case of single-sided image formation, the recording material S cooled by the recording material cooling device 50 is sandwiched and conveyed between a pair of discharge rollers 105, and is directly discharged onto a discharge tray 120. On the other hand, in the case of double-sided image formation, a switching member 110 (also called a flapper, etc.) switches the conveying path from the path continuing to the discharge tray 120 to a double-sided conveying path 111, and the recording material S sandwiched and conveyed between the discharge rollers 105 is sent to the double-sided conveying path 111. Thereafter, the leading and trailing ends are switched by a reversing roller 112, and the recording material S is again sent to a conveying path 114 via a double-sided path 113. The subsequent conveyance and the image formation process on the back side (second side) are the same as those described above, and therefore will not be described.

[0016] <Recording material cooling device> Next, the recording material cooling device 50 of this embodiment will be described with reference to Figs. 2 to 9(c). The recording material cooling device 50 of this embodiment is a belt-cooling type recording material cooling device. As shown in Fig. 2, the recording material cooling device 50 includes a first unit 501U and a second unit 502U. The first unit 501U includes an endless first belt 501, first belt tension rollers (501a to 501e) as first rollers, a heat sink 503, a sensor unit 390, and the like. On the other hand, the second unit 502U includes an endless second belt 502, second belt tension rollers (502a to 502e) as second rollers, pressure rollers (509a, 509b), a sensor unit 390, and the like.

[0017] Both the first belt 501 and the second belt 502 are endless film belts formed, for example, using a high-strength polyimide resin. The second belt 502 is wound around a plurality of second belt tension rollers 502a to 502e, and one of the second belt tension rollers 502a to 502e is rotated by a belt drive motor 511. In the case of this embodiment, the second belt tension roller 502e rotated by the belt drive motor 511 corresponds to a drive roller that drives the second belt 502. The second belt tension roller 502e is, for example, an aluminum roller having a diameter of 24.8 mm, and a silicone rubber having a thickness of 100 μm is formed on the outer circumferential surface thereof, so that the friction coefficient with the second belt 502 is set to "1.1".

[0018] The second belt tension roller 502a corresponds to a steering roller described later, and is, for example, an aluminum roller having a diameter of 25 mm, and has a friction coefficient with the second belt 502 set to "0.5" which is smaller than that of the second belt tension roller 502e (drive roller). The second belt tension rollers 502b to 502d correspond to idler rollers that tension the second belt 502, and are, for example, aluminum rollers having a diameter of 25 mm, and have a friction coefficient with the second belt 502 set to "0.1". The second belt tension roller 502e is rotated by the belt drive motor 511, so that the second belt 502 rotates in the direction of the arrow C in the figure.

[0019] In this embodiment, a drive train 504a is provided on the shaft end of the second belt tension roller 502e. The drive train 504a forms a part of a drive gear train for transmitting the rotational drive force of the belt drive motor 511 to rotate the first belt 501.

[0020] On the other hand, the first belt 501 is wound around a plurality of first belt tension rollers 501a to 501e so as to be able to come into contact with the second belt 502. At least one of the first belt tension rollers 501a to 501e is rotated by the driving force of a belt drive motor 511 via a drive gear train consisting of drive trains 504a to 504d. In the case of this embodiment, the first belt tension roller 501e rotated by the drive train 504d corresponds to the drive roller that drives the first belt 501. The first belt tension roller 501e is, for example, an aluminum roller having a diameter of 24.8 mm, and a silicone rubber having a thickness of 100 μm is formed on the outer circumferential surface, so that the friction coefficient with the first belt 501 is set to "1.1". As a result, the first belt 501 rotates in the direction of the arrow B in the figure. That is, the first belt 501 and the second belt 502 are rotated in the same direction in the cooling nip portion T4 by the belt drive motor 511, which is the same drive source.

[0021] The first belt tension roller 501a corresponds to a steering roller described later. The first belt tension roller 501a is, for example, an aluminum roller having a diameter of 25 mm, and an acrylic layer having a thickness of 100 μm is formed on the outer peripheral surface, so that the friction coefficient with the first belt 501 is set to "0.5" which is smaller than that of the first belt tension roller 501e (drive roller). The first belt tension rollers 501b to 501d correspond to idler rollers that tension the first belt 501, and are, for example, aluminum rollers having a diameter of 25 mm, and the friction coefficient with the first belt 501 is set to "0.1". The first belt tension roller 501e and the second belt tension roller 502e do not form a nip with each other. Note that, when the friction coefficient of the drive rollers (501e, 502e) is larger than that of the steering rollers (501a, 502a) as described above, if the drive roller is inclined relative to the other rollers, the belt deviation becomes more noticeable.

[0022] <One-way clutch> Each of the drive trains 504a to 504d that transmit the rotational driving force of the belt driving motor 511 is a gear. Any of the drive trains 504a to 504d has a one-way clutch 505 that blocks the transmission of the driving force depending on the direction of the driving force. In this embodiment, the one-way clutch 505 is press-fitted into the inner periphery of the drive train 504d and is disposed so that the center of rotation of the drive train 504d and the center of rotation of the one-way clutch 505 are the same. That is, the drive train 504d is provided on the rotation shaft of the first belt tension roller 501e via the one-way clutch 505.

[0023] When the first belt tension roller 501e and the drive train 504d move in the opposite directions relative to each other, the one-way clutch 505 does not transmit the driving force of the drive train 504d to the rotating shaft of the first belt tension roller 501e. That is, when the moving speed of the first belt 501 becomes faster than the moving speed of the second belt 502, the one-way clutch 505 cuts off the driving force between the drive train 504d and the rotating shaft of the first belt tension roller 501e. In that case, the first belt tension roller 501e rotates freely (idle) with respect to the drive train 504d. That is, regardless of the driving force transmission by the drive trains 504a to 504d, the first belt tension roller 501e and therefore the first belt 501 rotate.

[0024] In the case where the one-way clutch 505 is provided, when the moving speed of the first belt 501 becomes faster than the moving speed of the second belt 502, the drive train 504d rotates by receiving the driving force of the belt driving motor 511, and the first belt tension roller 501e rotates by receiving the rotation of the first belt 501. In this case, the first belt 501 is simply rotated together with the second belt 502 that contacts it at the cooling nip portion T4, and no driving force is applied by the belt driving motor 511. Therefore, the moving speed of the first belt 501 gradually decreases to be equal to the moving speed of the second belt 502, following the moving speed of the second belt 502.

[0025] As described above, as the moving speed of the first belt 501 decreases, the circumferential speed of the first belt stretching roller 501e decreases to or below the circumferential speed of the drive train 504d driven by the belt driving motor 511 via the drive trains 504a to 504c. Then, the one-way clutch 505 again puts the drive train 504d and the rotating shaft of the first belt stretching roller 501e into a drive transmission state. When the one-way clutch 505 puts the drive train 504d and the rotating shaft of the first belt stretching roller 501e into a drive transmission state, the driving force of the belt driving motor 511 is transmitted to the first belt stretching roller 501e, and the first belt stretching roller 501e is rotated according to the force. At this time, the moving speed of the first belt 501 and the moving speed of the second belt 502 are the same. Then, when the moving speed of the first belt 501 becomes faster than the moving speed of the second belt 502 again, the one-way clutch 505 puts the drive into a drive interruption state as described above.

[0026] In this way, the one-way clutch 505 is provided so as to be able to change between transmission and interruption of the drive force between the drive train 504d and the rotating shaft of the first belt tension roller 501e. In this way, when a speed difference occurs between the moving speed of the first belt 501 and the moving speed of the second belt 502, the one-way clutch 505 repeatedly switches between transmission and interruption of the drive force between the drive train 504d and the rotating shaft of the first belt tension roller 501e. This makes it possible to suppress the occurrence of a speed difference between the first belt 501 and the second belt 502.

[0027] <Heat sink> The recording material S on which the toner image is fixed is sandwiched between the first belt 501 and the second belt 502, and is conveyed in the conveying direction (arrow D direction) by the rotation of these belts. At that time, the recording material S passes through a cooling nip portion T4 formed by the first belt 501 and the second belt 502. In the case of this embodiment, the first belt 501 is cooled by a heat sink 503. The heat sink 503 is arranged so as to abut against the inner circumferential surface of the first belt 501 at a location forming the cooling nip portion T4 in order to efficiently cool the recording material S. The recording material S is cooled through the first belt 501 when passing through the cooling nip portion T4. For example, if the temperature of the recording material S is about 90° C. before passing through the recording material cooling device 50, the recording material S is cooled so that the temperature becomes about 60° C. after passing through the recording material cooling device 50. As the recording material S is cooled, the toner on the recording material S is cooled and fixed.

[0028] The heat sink 503 as a cooling member is a heat dissipation plate made of metal such as aluminum. The heat sink 503 has a heat receiving portion 503a for contacting the first belt 501 to take heat from the first belt 501, a heat dissipation portion 503b for dissipating heat, and a fin base 503c for conducting heat from the heat receiving portion 503a to the heat dissipation portion 503b. The heat dissipation portion 503b is formed of a large number of heat dissipation fins to increase the contact area with the air and promote efficient heat dissipation. For example, the heat dissipation fins are set to a thickness of 1 mm, a height of 100 mm, and a pitch of 5 mm, and the fin base 503c is set to a thickness of 10 mm. In order to forcibly cool the heat sink 503 itself, one or more cooling fans 513 are provided to blow air toward the heat sink 503 (more specifically, the heat dissipation portion 503b). The air volume of the cooling fan 513 is, for example, 2 m 3 The cooling of the heat sink 503 is not limited to the cooling fan 513.

[0029] On the other hand, pressure rollers 509a and 509b are provided on the inner circumferential side of the second belt 502 to pressurize the second belt 502 toward the heat sink 503 of the second unit 502U. The pressure rollers 509a and 509b as pressure members press the second belt 502 with a pressure of, for example, 9.8 N (1 kgf). This ensures that the first belt 501 is in contact with the heat sink 503 (a heat receiving portion 503a described later in detail) via the second belt 502.

[0030] <Steering control> In such a recording material cooling device 50, when an endless belt such as the first belt 501 and the second belt 502 is supported and rotated by a plurality of rollers, a meandering phenomenon in which the rotating belt moves in the width direction may occur. Therefore, one of the plurality of rollers that stretch the first belt 501 and the second belt 502 is tilted as a steering roller, and the first belt 501 and the second belt 502 are moved back and forth in the width direction to suppress the meandering phenomenon.

[0031] In this embodiment, the first belt tension roller 501a and the second belt tension roller 502a are steering rollers provided to control the deviation of the first belt 501 and the second belt 502, respectively. These steering rollers (501a, 502a) press the first belt 501 and the second belt 502 from the inner circumferential side toward the outer circumferential side so that the tension of the first belt 501 and the second belt 502 is, for example, about 39.2 N (about 4 kgf). To achieve this, the first belt tension roller 501a is biased by a spring 507a, and the second belt tension roller 502a is biased by a spring 508a. The steering rollers (501a, 502a) are separately steered by the steering mechanism 400 with the center of the rotation axis direction (width direction) as a pivot point, thereby controlling the meandering of the first belt 501 and the second belt 502 (steering control).

[0032] A sensor unit 390 for detecting the end positions of the first belt 501 and the second belt 502 is provided at one point on each of the rotation paths of the first belt 501 and the second belt 502. Based on a detection signal from this sensor unit 390, the end positions of the first belt 501 and the second belt 502 during rotation are detected. Then, the steering mechanism 400 described above is operated based on the detected end positions, thereby adjusting the steering angle of the steering rollers (501a, 502a).

[0033] <About belt connection and disconnection> The first unit 501U is provided so as to be movable between a contact position where the first belt 501 and the second belt 502 are in contact with each other to form the cooling nip T4, and a separation position where the first belt 501 and the second belt 502 are spaced apart so as not to form the cooling nip T4. Fig. 3 shows the first unit 501U in the contact position, and Fig. 4 shows the first unit 501U in the separation position.

[0034] In the present embodiment, the first unit 501U is provided to be rotatable up and down with respect to the second unit 502U about a rotation axis (not shown) of a rotation mechanism 510 as a rotation means as a rotation center. This is to enable an operator to separate the first belt 501 and the second belt 502 and remove the recording material S sandwiched in the cooling nip portion T4 when a so-called jam occurs in the recording material cooling device 50, in which the recording material S is retained in the device. This is also to enable an operator to loosen the first belt 501 and the second belt 502 in order to replace the first belt 501 and the second belt 502, as described later.

[0035] As shown in Fig. 3 and Fig. 4, a first front support plate 524 is disposed on one end side of the first belt tension rollers 501a to 501e. The first front support plate 524 rotatably supports one end side of the first belt tension rollers 501a to 501e and supports one end side of the heat sink 503. A first rear support plate 525 is disposed on the other end side of the first belt tension rollers 501a to 501e, and the first rear support plate 525 rotatably supports the other end side of the first belt tension rollers 501a to 501e and supports the other end side of the heat sink 503. The first front support plate 524 as the third support member and the first rear support plate 525 as the fourth support member are each a single member formed of sheet metal.

[0036] On the other hand, a second front support plate 526 is disposed on one end side of the second belt tension rollers 502a to 502e, and the second front support plate 526 rotatably supports one end side of the second belt tension rollers 502a to 502e and the pressure rollers 509a, 509b (see FIG. 2). A second rear support plate 527 is disposed on the other end side of the second belt tension rollers 502a to 502e and the pressure rollers 509a, 509b. The second rear support plate 527 rotatably supports the other end side of the second belt tension rollers 502a to 502e and the pressure rollers 509a, 509b. The second front support plate 526 as the first support member and the second rear support plate 527 as the second support member are each a single member formed of sheet metal.

[0037] <Pressure release lever> In the recording material cooling device 50 of this embodiment, in order to facilitate an operator's replacement of the first belt 501, the steering roller (501a) can be moved between a tensioned position where the first belt 501 is tensioned and a non-tensioned position where the first belt 501 is loosened. When the steering roller (501a) is in the non-tensioned position, the contact pressure on the first belt 501 is smaller than when the steering roller (501a) is in the tensioned position, and the tension of the first belt 501 is loosened. Similarly, in order for an operator to replace the second belt 502, the steering roller (502a) can be manually moved between a tensioned position where the second belt 502 is tensioned and a non-tensioned position where the second belt 502 is loosened.

[0038] As shown in Fig. 5, in each of the first unit 501U and the second unit 502U, a pressure release lever (560, 570) is rotatably provided on one end side of the steering roller (501a, 502a). When an operator grips and rotates the pressure release lever (560, 570), the steering roller (501a, 502a) moves between a tensioned position and a non-tensioned position. For example, when the operator rotates the pressure release lever 560 of the first unit 501U in the direction of arrow V, the first belt 501 is in a tensioned state, and when the pressure release lever 560 is rotated in the opposite direction to the direction of arrow V, the first belt 501 is in a slackened state. On the other hand, when the operator rotates the pressure release lever 570 of the second unit 502U in the direction of the arrow W, the second belt 502 becomes tensioned, and when the pressure release lever 570 is rotated in the opposite direction to the direction of the arrow W, the second belt 502 becomes slack and not tensioned.

[0039] In this embodiment, the front surface of the first unit 501U is covered by a front cover 550 attached by screws or the like to each of the cover attachment parts 530, 531 provided on the first front support plate 524. The front cover 550 can be detachably attached to the cover attachment parts 530, 531 so as to cover the pressure release lever 560 of the first unit 501U. Therefore, in the case of the first unit 501U, the operator needs to remove the front cover 550 in order to access and operate the pressure release lever 560.

[0040] On the other hand, the front of the second unit 502U is covered by a sheet metal cover 555 attached to a body frame (not shown). The sheet metal cover 555 is detachably attached to the body frame in a state in which it is arranged so as to cover the pressure release lever 570 of the second unit 502U. Therefore, in order for an operator to access the pressure release lever 570, it is necessary to remove the sheet metal cover 555. However, in the second unit 502U, in order to suppress the rotation of the pressure release lever 570, a gripping portion 570a of the pressure release lever 570 held by an operator is fitted into a fitting hole 851a formed in a front holding plate 851 of a unit holding portion 850 (described later). This fitting hole 851a is formed in a shape following the outer shape of the gripping portion 570a. In other words, when the gripping portion 570a is fitted into the fitting hole 851a, the pressure release lever 570 is prevented from rotating in either the direction of the arrow W or the direction opposite to the direction of the arrow W. Therefore, in the case of the second unit 502U, the worker needs to remove not only the sheet metal cover 555 but also the front holding plate 851 in order to access and operate the pressure release lever 570.

[0041] Thus, in the case of this embodiment, in the first unit 501U, the worker can operate the pressure release lever 560 by simply removing the front cover 550. On the other hand, in the second unit 502U, the worker cannot operate the pressure release lever 570 unless he removes the sheet metal cover 555 and the front holding plate 851. This is because the pressure release lever 560 of the first unit 501U is used more frequently than the pressure release lever 570 of the second unit 502U. That is, since the first belt 501 rubs against the heat sink 503, it is more likely to wear out than the second belt 502 which does not rub against the heat sink 503. Therefore, the replacement frequency of the first belt 501 is higher than that of the second belt 502, and from the viewpoint of improving the replaceability of the first belt 501 which is replaced frequently by the worker, the pressure release lever 560 is made easy to operate in the first unit 501U as described above.

[0042] <Static charge removal needle> In the case of the belt-cooling type recording material cooling device 50, the first belt 501 is likely to be charged by rubbing against the heat sink 503 during rotation, and the second belt 502 is likely to be charged by rotating in contact with the first belt 501. When the first belt 501 or the second belt 502 is charged, the recording material S may stick to the first belt 501 or the second belt 502 or curl, and the recording material S may easily become stuck in the device, i.e., a so-called jam. In addition, when the first belt 501 or the second belt 502 is in a charged state, the recording material S that has passed through the cooling nip portion T4 (see FIG. 2) may become charged. When the recording material S is charged, it becomes difficult for the recording material S to be discharged to the discharge tray 120 (see FIG. 1) in the correct posture, and there is a risk that the recording material S may not be properly stacked on the discharge tray 120.

[0043] 6, the first unit 501U and the second unit 502U are provided with static elimination needles 600, 601, respectively, downstream of the cooling nip portion T4 (see FIG. 2) in the conveying direction of the recording material S. Specifically, in the first unit 501U, the static elimination needle 600 is attached to a connecting metal plate 701 that connects the first front support plate 524 and the first rear support plate 525 by an attaching member 602 (e.g., a sticker or the like). The tip of the static elimination needle 600 comes into contact with the outer circumferential surface of the rotating first belt 501, thereby suppressing the charging of the first belt 501.

[0044] Similarly, in the second unit 502U, the static elimination needle 601 is attached by an attaching member 603 (e.g., a sticker) to a connecting metal plate 702 that connects the second front support plate 526 and the second rear support plate 527. The tip of the static elimination needle 601 comes into contact with the outer circumferential surface of the rotating second belt 502, thereby suppressing the charging of the second belt 502. Note that a pair of discharge guides 700 are provided on each of the connecting metal plates 701 and 702 in order to discharge the recording material S that has passed through the cooling nip portion T4 while holding it from both sides.

[0045] 7, in this embodiment, the above-mentioned steering mechanism 400 and cooling fan 513 (one in this embodiment) are attached to the first rear support plate 525 of the first unit 501U. On the other hand, the steering mechanism 400 is also attached to the second rear support plate 527 of the second unit 502U. In addition, the turning mechanism 510 is attached across the first rear support plate 525 of the first unit 501U and the second rear support plate 527 of the second unit 502U. Therefore, as the turning mechanism 510 turns the first unit 501U, the steering mechanism 400 and the cooling fan 513 turn together with the first unit 501U.

[0046] The second rear support plate 527 is provided with a positioning portion 590 for positioning the recording material cooling device 50 when it is attached to the apparatus main body 100A (see FIG. 1). The positioning portion 590 has a plurality of fitting portions 591 arranged at intervals in the recording material transport direction and extending in the width direction. These fitting portions 591 are formed, for example, in the shape of a cylindrical shaft, and are fitted into fitting portions formed on the main body frame of the apparatus main body 100A. In this way, the recording material cooling device 50 is attached to the apparatus main body 100A with the second rear support plate 527 side of the second unit 502U as a reference.

[0047] The recording material cooling device 50 has a unit holding part 850. The unit holding part 850 forms a holding frame that holds the second unit 502U by a front holding plate 851 that holds the second front support plate 526, a rear holding plate 853 that holds the second rear support plate 527, and two connecting plates 852 that connect the front holding plate 851 and the rear holding plate 853.

[0048] The front holding plate 851 and the connecting plate 852 are each formed with a plurality of mounting holes through which mounting screws are inserted. In this embodiment, the front holding plate 851 and the two connecting plates 852 are each screwed to the main body frame with mounting screws in a state in which the plurality of fitting portions 591 are fitted to the respective fitting portions, and thus the recording material cooling device 50 is fixed to the apparatus main body 100A. As will be described in detail later, the second front support plate 526 is provided so as to be movable relative to the front holding plate 851 (see Figs. 8 to 9(c) described later). The front holding plate 851 is provided so as to be detachable from the connecting plate 852. This is because, as described above, in this embodiment, the front holding plate 851 prevents the pressure release lever 570 from turning, and the operator needs to remove the front holding plate 851 in order to operate the pressure release lever 570.

[0049] Incidentally, in a conventional belt-cooling type recording material cooling device, even though steering control is performed, the belt may shift too far, resulting in damage to the belt and the front and rear support plates that support the rollers around which the belt is stretched. This was particularly noticeable in the second unit 502U that does not have the heat sink 503. This is due to the following reasons.

[0050] In the first unit 501U having the heat sink 503, the first front support plate 524 and the first rear support plate 525 are formed of high-rigidity metal plate in order to support the heavy heat sink 503. In contrast, in the second unit 502U, since there is no need to support the heat sink 503, the second front support plate 526 is formed of low-rigidity metal plate. The second rear support plate 527 is formed of high-rigidity metal plate in order to mount the pivot mechanism 510. Therefore, in the past, the recording material cooling device was sometimes mounted to the device main body 100A in a state in which the second front support plate 526 was deformed and inclined relative to the second rear support plate 527 due to component tolerances at locations that affect mounting in the recording material cooling device and the device main body 100A.

[0051] For example, the second front support plate 526 is deformed due to component tolerances of the fitting portion 591 of the positioning portion 590 in the recording material cooling device, the mounting hole of the unit holding portion 850, the fitted portion that fits into the fitting portion 591 in the apparatus main body 100A, and the hole into which the mounting screw is screwed. In such a case, a relative inclination greater than expected occurs in each roller that stretches the second belt 502, and it becomes difficult to suppress the deviation of the second belt 502 even if steering control is performed to tilt the steering roller (502a) in the second unit 502U.

[0052] As shown in Fig. 2, it is assumed that the recording material cooling device is fixed to the apparatus main body 100A in a state in which the second front support plate 526 is inclined in the direction of the arrow G relative to the second rear support plate 527 (see Fig. 3). Then, the steering roller (502a) is inclined toward the outside of the second belt 502 so that one end of the steering roller (502a) supported by the second front support plate 526 is positioned lower than the other end of the steering roller (502a) supported by the second rear support plate 527. Therefore, the second belt 502 stretched around the steering roller (502a) is easily moved toward the second rear support plate 527.

[0053] Conversely, suppose that the recording material cooling device is fixed to the apparatus main body 100A in a state in which the second front support plate 526 is inclined in the direction of the arrow H relative to the second rear support plate 527 (see FIG. 3). Then, the steering roller (502a) is inclined toward the inside of the second belt 502 so that one end of the steering roller (502a) supported by the second front support plate 526 is positioned higher than the other end of the steering roller (502a) supported by the second rear support plate 527. Therefore, the second belt 502 stretched around the steering roller (502a) is easily moved toward the second front support plate 526.

[0054] The greater the inclination of the second front support plate 526 in the direction of the arrow G relative to the second rear support plate 527, the faster the moving speed of the second belt 502 moving toward the second front support plate 526 due to steering control than the moving speed of the second rear support plate 527. Conversely, the greater the inclination of the second front support plate 526 in the direction of the arrow H relative to the second rear support plate 527, the slower the moving speed of the second belt 502 moving toward the second front support plate 526 due to steering control than the moving speed of the second rear support plate 527. In this way, when the inclination of the second front support plate 526 relative to the second rear support plate 527 becomes large, the difference between the moving speed of the second belt 502 moving toward the second front support plate 526 side and the moving speed of the second belt 502 moving toward the second rear support plate 527 side becomes large. Furthermore, if the moving speed of the second belt 502 becomes too high, even if steering control is performed to reverse the moving direction of the second belt 502 in the width direction, the second belt 502 may experience transient slippage and end up shifting to the other side without reversing.

[0055] <Adjustment operation mechanism> In view of the above, in this embodiment, when an operator attaches the recording material cooling device 50 to the apparatus main body 100A, the operator can adjust the relative inclination of the rollers supported by the second front support plate 526 (and the second rear support plate 527). The operator can adjust the relative inclination of the rollers supported by the second front support plate 526 after fixing the unit holding part 850 (specifically, the front holding plate 851, the connecting plate 852, and the rear holding plate 853) to the apparatus main body 100A. In order to enable this, the recording material cooling device 50 is provided with an adjustment mechanism 800. When the adjustment mechanism 800 is operated by the operator, the second front support plate 526 is rotated relative to the front holding plate 851, and the relative inclination of the rollers supported by the second front support plate 526 changes accordingly. This point will be described below with reference to FIGS. 8 to 9(c).

[0056] 8, in the second unit 502U, the second front support plate 526 is attached to a front support plate 851 which is screwed to the main body frame. The front support plate 851 as a holding member is formed with a plurality of mounting holes 970 (two in this example) through which mounting screws (not shown) are inserted when the front support plate 851 is screwed to the main body frame. The mounting holes 970 are elongated holes that are long in the width direction, and allow the front support plate 851 to be fixed to the main body frame by correcting misalignment in the width direction of the second front support plate 526 caused by component tolerances on the upstream and downstream sides in the recording material transport direction.

[0057] The second front support plate 526 is formed with a first protruding shaft 520 and a second protruding shaft 521 having a shaft shape protruding toward the front support plate 851. The first protruding shaft 520 has a tip fitted into a fitting hole 529 formed in the front support plate 851 so that the second front support plate 526 can rotate with respect to the front support plate 851 around the first protruding shaft 520 as a rotation center. The second front support plate 526 is also formed with two support holes 957 to sandwich the second protruding shaft 521, and one mounting portion 952 between the first protruding shaft 520 and the second protruding shaft 521. After adjusting the relative inclination of the rollers as described below, the operator can fix the second front support plate 526 to the front support plate 851 at any rotation position by attaching a fixing screw 950 as a fixing member to the mounting portion 952. The front holding plate 851 is formed with an elongated through hole 951 through which a fixing screw 950 used to fix the second front support plate 526 is inserted.

[0058] An adjustment operation mechanism 800 is rotatably provided on the front holding plate 851 on the side opposite to the side facing the second front support plate 526. The adjustment operation mechanism 800 as an operation member has an adjustment plate 801 and an eccentric cam 802. The adjustment plate 801 as a rotating part is formed in a substantially L-shape and has a gripping part 801a that is gripped by a user. The adjustment plate 801 is formed with a substantially D-shaped fitting hole 801b into which the eccentric cam 802 is fitted, and two arc-shaped insertion holes 801c into which the screws 955 are inserted, sandwiching the fitting hole 801b. The eccentric cam 802 is fitted into the fitting hole 801b, so that it rotates and displaces together with the adjustment plate 801 in accordance with the rotation of the adjustment plate 801. A cam surface 802b of the eccentric cam 802 engages with a hole 518a formed in the front holding plate 851. The eccentric cam 802 is formed with a support hole 802a that supports the tip of the second protruding shaft 521 of the second front support plate 526. That is, the second front support plate 526 and the eccentric cam 802 are connected to each other so as to be able to operate together by the second protruding shaft 521 serving as a connecting member.

[0059] The rotation range of the adjustment operation mechanism 800 is limited by two screws 955 inserted into insertion holes 801c formed in the adjustment plate 801. The screws 955 are passed through the insertion holes 801c and through holes 956 formed in the front holding plate 851, and are attached to support holes 957 formed in the second front support plate 526.

[0060] According to the above-mentioned configuration, when the second front support plate 526 is not fixed to the front holding plate 851 by the fixing screw 950, the user operates the adjustment plate 801 to rotate the first protruding shaft 520 relative to the front holding plate 851 as the rotation center. Specific examples are shown in Figures 9(a) to 9(c).

[0061] As shown in Fig. 9(a), it is assumed that the unit holding part 850 is fixed to the apparatus main body 100A in a state where the second front support plate 526 supporting the second belt tension rollers 502a to 502e (see Fig. 2) is deformed in the direction of the arrow L. In this case, the second front support plate 526 is deformed due to the component tolerance of the second unit 502U or the apparatus main body 100A (see Fig. 1), so that at least one of the second belt tension rollers 502a to 502e may be inclined relatively. In addition, the position (initial position) of the adjustment operation mechanism 800 at this time changes depending on the degree of deformation of the second front support plate 526, more specifically, depending on the degree of inclination of the second front support plate 526 with respect to the second rear support plate 527.

[0062] In the state shown in Fig. 9(a), an operator rotates the adjustment plate 801 of the adjustment operation mechanism 800 in the direction of arrow J before fixing the second front support plate 526 to the front holding plate 851 with the fixing screw 950. When the operator rotates the adjustment plate 801 in the direction of arrow J, the eccentric cam 802 pushes up the second protruding shaft 521 of the second front support plate 526 in the direction of gravity. This causes the second front support plate 526 to rotate in the direction of arrow M. Note that Fig. 9(a) shows a state in which the rotation of the adjustment plate 801 in the direction of arrow K is restricted by two screws 955.

[0063] 9(b), the unit holding part 850 is fixed to the apparatus main body 100A in a state in which the second front support plate 526 is deformed in the direction of the arrow M. Even in this case, the second front support plate 526 may be deformed due to the component tolerances of the second unit 502U and the apparatus main body 100A, causing at least one of the second belt tension rollers 502a to 502e to tilt relatively.

[0064] In the state shown in Fig. 9(b), an operator rotates the adjustment plate 801 of the adjustment operation mechanism 800 in the direction of arrow K before fixing the second front support plate 526 to the front holding plate 851 with the fixing screw 950. When the operator rotates the adjustment plate 801 in the direction of arrow K, the eccentric cam 802 presses the second protruding shaft 521 of the second front support plate 526 down in the direction of gravity. This causes the second front support plate 526 to rotate in the direction of arrow L. Note that Fig. 9(b) shows a state in which the rotation of the adjustment plate 801 in the direction of arrow J is restricted by two screws 955.

[0065] As described above, when the operator rotates the adjustment plate 801 in the direction of the arrow J or the direction of the arrow K, the second front support plate 526 is rotated in the direction of the arrow M or the direction of the arrow L, and the deformation of the second front support plate 526 caused by the part tolerance of the second unit 502U or the device main body 100A is corrected. When the deformation of the second front support plate 526 is corrected, even if the second belt tension rollers 502a to 502e supported by the second front support plate 526 are relatively inclined before the correction, the second belt tension rollers 502a to 502e are adjusted to be substantially parallel as shown in FIG. 9(c). After that, the operator fixes the second front support plate 526 to the front holding plate 851 using the fixing screw 950. By fixing the second front support plate 526 to the front holding plate 851 with the fixing screw 950, the second front support plate 526 is maintained in a corrected state in which the deformation caused by the part tolerance is suppressed. In this manner, by adjusting the second belt tension rollers 502a to 502e to be substantially parallel to each other, it is possible to suppress the belt deviation of the second belt 502 by the steering control.

[0066] In the above-described embodiment, the second unit 502U is provided with the adjustment mechanism 800, and when an operator attaches the recording material cooling device 50 to the apparatus main body 100A, the deformation of the second front support plate 526 caused by the component tolerance of the second unit 502U or the apparatus main body 100A can be corrected. In contrast, the first unit 501U is not provided with the adjustment mechanism 800. This is because, as described above, the first unit 501U uses the first front support plate 524 and the first rear support plate 525, which have high rigidity, to support the heat sink 503, and the first belt tension rollers 501a to 501e are supported by these. If the first front support plate 524 and the first rear support plate 525 have high rigidity, the first front support plate 524 and the first rear support plate 525 are unlikely to deform even if the first unit 501U is attached to the apparatus main body 100A. Therefore, in the first belt tension rollers 501a-501e of the first unit 501U, the relative inclination of the rollers is less likely to occur to the extent that it becomes difficult to suppress the belt shift by steering control, compared to the second belt tension rollers 502a-502e of the second unit 502U. In the case of the first unit 501U having the heat sink 503, the belt shift of the first belt 501 can be sufficiently suppressed by steering control. For this reason, the adjustment operation mechanism 800 is not provided in the first unit 501U.

[0067] As described above, in the present embodiment, the charge removal needle 600 (charge suppression member) is provided so as to be in contact with the outer circumferential surface of the first belt 501 rotating in the first unit 501U. The charge removal needle 600, which is in direct contact with the outer circumferential surface of the first belt 501, is always in contact with the rotating first belt 501, so that the charge of the first belt 501 can be effectively suppressed. In addition, the charge removal needle 601 (charge suppression member) is provided so as to be in contact with the outer circumferential surface of the second belt 502 rotating in the second unit 502U. The charge removal needle 601, which is in direct contact with the outer circumferential surface of the second belt 502, is always in contact with the rotating second belt 502, so that the charge of the second belt 502 can be effectively suppressed. Therefore, it is possible to suppress the occurrence of jams and curls of the recording material S caused by the charging of the belt.

[0068] <Other embodiments> In the above embodiment, in order to rotate the second front support plate 526 relative to the front support plate 851, the first protruding shaft 520 and the second protruding shaft 521 are provided on the second front support plate 526, and the fitting hole 529 and the hole portion 518a are formed on the front support plate 851 (see FIG. 8), but the present invention is not limited thereto. For example, instead of the first protruding shaft 520, a rotation shaft protruding from the front support plate 851 toward the second front support plate 526 may be provided, and a hole portion for rotatably supporting the rotation shaft may be formed in the second front support plate 526. Also, instead of the second protruding shaft 521, a cam protruding shaft protruding from the eccentric cam 955 toward the second front support plate 526 may be provided, and a hole portion for fixing the cam protruding shaft may be formed in the second front support plate 526.

[0069] In the above-described embodiment, the recording material cooling device 50 is provided inside the image forming apparatus 100 (see FIG. 1), but the present invention is not limited to this. For example, the recording material cooling device 50 may be provided outside the apparatus main body 100A. FIG. 10 shows an image forming system 1X in which the recording material cooling device 50 is provided outside the image forming apparatus 100.

[0070] 10 includes an image forming apparatus 100 and an external cooling unit 101 connected to the image forming apparatus 100. The external cooling unit 101 is configured to be connectable to the image forming apparatus 100 as one of peripheral devices (called an optional unit, etc.) that can be added later to expand the functions of the image forming apparatus 100. The external cooling unit 101 is disposed to cool the recording material S discharged from the image forming apparatus 100 and to lower the temperature of the recording material S, which is higher than that before fixing, to a predetermined temperature or lower. The external cooling unit 101 includes the above-mentioned recording material cooling device 50 for cooling the recording material S.

[0071] The recording material S cooled by the external cooling unit 101 is discharged from the external cooling unit 101 by a discharge roller 85 and is stacked on a discharge tray 120. The discharge tray 120 is provided so as to be detachable from the external cooling unit 101 and the image forming apparatus 100. That is, when the external cooling unit 101 is not connected to the image forming apparatus 100, the discharge tray 120 is attached to the image forming apparatus 100 (see FIG. 1). When the external cooling unit 101 is connected to the image forming apparatus 100, the discharge tray 120 is removed from the image forming apparatus 100 by an operator and replaced with the external cooling unit 101. Note that a plurality of external cooling units 101 may be connected as peripheral devices. An operator can easily improve the cooling capacity of the recording material S of an existing image forming apparatus 100 by increasing the number of external cooling units 101 to be connected. [Explanation of symbols]

[0072] 1X...image forming system, 30...fixing device, 50...recording material cooling device, 100...image forming device, 100A...apparatus main body, 200...image forming unit, 400...steering means (steering mechanism), 501...first belt, 501a to 501e...first rollers (first belt tension rollers), 501U...first unit, 502...second belt, 502a to 502e...second rollers (second belt tension rollers), 502U...second unit, 503...cooling member (heat sink, heat sink) ), 510...rotating means (rotating mechanism), 521...connecting member (second protruding shaft), 524...third support member (first front support plate), 525...fourth support member (first rear support plate), 526...first support member (second front support plate), 527...second support member (second rear support plate), 800...operating member (adjusting operation mechanism), 801...rotating portion (adjusting plate), 801a...gripping portion, 802...eccentric cam, 851...holding member (front holding plate), 950...fixing member (fixing screw), S...recording material, T4...nip portion (cooling nip portion)

Claims

1. A recording material cooling device that is attached to an apparatus body of an image forming apparatus having a fixing device and cools a recording material on which a toner image has been fixed by the fixing device, an endless belt that comes into contact with a toner image forming surface of the recording material when an image is formed on one side of the recording material; A plurality of rollers around which the belt is stretched; a cooling member that contacts an inner circumferential surface of the belt to cool the belt; a conveying unit that forms a first nip portion together with the belt and conveys the recording material; a charge suppressing member that contacts an outer peripheral surface of the belt and suppresses charging of the belt; A pair of side plates supporting the plurality of rollers; A connecting member that connects the pair of side plates, The static electricity suppressing member is provided on the connecting member. A recording material cooling device comprising:

2. the charge suppressing member is provided downstream of the first nip portion in a conveying direction of the recording material in the first nip portion, 2. The recording material cooling device according to claim 1,

3. The charge suppressing member is provided downstream of the cooling member in a conveying direction of the recording material in the first nip portion.

2. The recording material cooling device according to claim 1,

4. The charge suppressing member is a charge eliminating needle.

4. The recording material cooling device according to claim 1, wherein the recording material cooling device is a cooling device for cooling a recording material.

5. a guide member that is provided downstream of the first nip portion in a conveying direction of the recording material in the first nip portion and that guides the recording material discharged from the first nip portion, The guide member is provided on the connecting member.

2. The recording material cooling device according to claim 1,

6. the conveying unit includes another belt that forms the first nip portion together with the belt, a plurality of rollers that stretch the other belt, and another charge suppressing member that contacts an outer circumferential surface of the other belt and suppresses charging of the other belt, 6. The recording material cooling device according to claim 1, wherein the recording material cooling device is a cooling device for cooling a recording material.

7. a first unit having the belt, the plurality of rollers, and the cooling member; A second unit having the transport unit; a rotation mechanism that rotatably supports the first unit with respect to the second unit, 7. The recording material cooling device according to claim 1, wherein the recording material cooling device is a cooling device for cooling a recording material.

8. the image forming apparatus includes a fixing device having a heating rotator that heats a recording material, and a pressure rotator that contacts the heating rotator to form a second nip portion that fixes a toner image onto the recording material; the recording material cooling device is disposed downstream of the second nip portion in a conveying direction of the recording material; 8. The recording material cooling device according to claim 1, wherein the recording material cooling device is a cooling device for cooling a recording material.

9. The connecting member is made of sheet metal.

9. The recording material cooling device according to claim 1, wherein the recording material cooling device is a cooling device for cooling a recording material.

Images