Patent Application
20240375893
The present disclosure relates to a sheet stacking apparatus configured to store a sheet and convey the stored sheet and an image forming apparatus.
In the image forming apparatus configured to form an image on a sheet conveyed by the sheet stacking apparatus, the sheet conveyed by the sheet stacking apparatus may be greatly deviated in a width direction orthogonal to a conveyance direction of the sheet with respect to the image formed by the image forming apparatus. A deviation in a position (hereinafter referred to as a lateral registration position) in the width direction of the sheet with respect to a reference position in which the image is formed may be 4 millimeters (mm) to 8 mm due to the component tolerance of the sheet stacking apparatus or the deviation at the time of installation. Accordingly, a sheet stacking apparatus having a registration mechanism configured to correct a deviation in the lateral registration position of a sheet and an image forming apparatus having a mechanism configured to correct a deviation in the lateral registration position of a formed image have been proposed. However, if the deviation in the lateral registration position is large, an image may not be formed in a desired position on the sheet.
Therefore, Japanese Patent Application Laid-Open No. H07-261626 discloses a sheet stacking apparatus in which a position of a sheet storage can be adjusted in a front-rear direction, which is the width direction, with respect to a main body frame of the sheet stacking apparatus. By adjusting the position of the sheet storage with respect to the main body frame in the front-rear direction, the deviation between the image and the lateral registration position of the sheet can be corrected.
In a case in which the image forming apparatus is installed in a high humidity environment, the sheet before image formation in the sheet stacking apparatus absorbs the moisture of the installation environment, and an undulation occurs in the sheet. A deformation of the sheet due to such undulation may deteriorate the image formed on the sheet.
According to an aspect of the present disclosure, a sheet stacking apparatus includes a storage configured to store a sheet, a conveyance unit configured to convey the sheet stored in the storage in a conveyance direction, a sealing member, and a holder configured to movably hold the storage in a sheet width direction orthogonal to the conveyance direction, wherein the storage includes a first unit including a pair of regulating members configured to regulate both edges of the sheet stored in the storage in the sheet width direction, and a second unit including a second sealing surface disposed opposite to a first sealing surface provided on the holder, wherein the sealing member is disposed between the first sealing surface and the second sealing surface, and wherein a relative position between the first unit and the second unit is changeable.
Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Hereinafter, the present disclosure will be described using the embodiments. It should be noted that the scope of the present disclosure is not limited to the embodiments described below, and that not all configurations described in the embodiments should be interpreted as essential configurations needed to define the present disclosure.
Hereinafter, an inkjet recording apparatus 10 will be described as an example of an image forming apparatus according to the present embodiment with reference to the accompanying drawings.
The feeding module 1000 includes three storages (sheet storages) 1100a, 1100b, and 1100c, each of which stores a plurality of sheets. The storages 1100a, 1100b, and 1100c are configured so that they can be pulled out to the front side of the feeding module 1000. The sheets stored in the storages 1100a, 1100b, and 1100c are conveyed to the print module 2000 one sheet at a time by one of feeding portions 1102a, 1102b, and 1102c as conveyance units in a conveyance direction CD. Each of the feeding portions 1102a, 1102b, and 1102c includes a separating belt and a conveying roller as a separating unit. The sheets stacked in the storages 1100a, 1100b, and 1100c are fed one by one by the separating belt and the conveying roller and conveyed to the print module 2000. The number of the storages 1100a, 1100b, and 1100c is not limited to 3, but may be 1, 2, 4 or more.
The print module 2000 includes a before-image-formation registration correcting portion 2100, a print belt unit 2200, and a recording portion (image forming portion) 2300. The sheet conveyed from the feeding module 1000 is corrected in inclination and position of the sheet by the before-image-formation registration correcting portion 2100 and conveyed to the print belt unit 2200. The recording portion 2300 is disposed in a position opposite to the print belt unit 2200 with respect to the conveyance path. The recording portion 2300 is a sheet processing portion configured to form an ink image (image) on the sheet by performing recording processing (printing) with a recording head from above the sheet to be conveyed. The sheet is sucked and conveyed by the print belt unit 2200 so that a clearance (print gap) between the recording head and the sheet is ensured.
A plurality of recording heads are disposed along the conveyance direction CD. In the embodiment, the recording portion 2300 has a total of five line-type recording heads corresponding to the reaction solution in addition to four colors of Y (yellow), M (magenta), C (cyan), and Bk (black). The number of colors and the number of recording heads are not limited to 5, but may be 1, 2, 3, 4 or 6 or more. The inkjet method may employ various methods such as a method using a heating element, a method using a piezo element, a method using an electrostatic element, a method using a Micro Electro Mechanical Systems (MEMS) element, and the like. The ink of each color is supplied from an ink tank (not shown) to the recording head through an ink tube. The sheet on which the ink image is formed by the recording portion 2300 is conveyed to an in-line scanner (not shown) disposed downstream of the recording portion 2300 by the print belt unit 2200. The in-line scanner (not shown) detects a deviation and a color density of the ink image formed on the sheet by the recording portion 2300, and a detection result is used to correct an ink image subsequently formed.
The drying module 3000 includes a decoupling portion 3200, a drying belt unit 3300, and a hot air blowing portion 3400. The drying module 3000 is a unit which reduces a liquid content contained in the ink imparted on the sheet by the recording portion 2300 and enhances a fixability between the sheet and the ink. The sheet on which the ink image is formed by the recording portion 2300 of the print module 2000 is conveyed to the decoupling portion 3200 disposed in the drying module 3000. The decoupling portion 3200 weakly holds the sheet on the belt by applying wind pressure from above and conveys the sheet by a friction force of a belt. Thus, the sheet on which the ink image is formed on the print belt unit 2200 is prevented from deviating. The sheet conveyed from the decoupling portion 3200 is sucked and conveyed by the drying belt unit 3300 and is blown by hot air from the hot air blowing portion 3400 disposed above the drying belt unit 3300 to dry an ink imparting surface of the sheet. In addition to the method of imparting the hot air, the drying method may be a method of irradiating the surface of the sheet with electromagnetic waves (ultraviolet rays, infrared rays, etc.), a method of conducting heat transfer by contact of a heating element, or a method combining these methods.
The fixing module 4000 includes a fixing belt unit 4100 and a first reversing portion 4200. The fixing belt unit 4100 allows ink to be fixed to the sheet by passing the sheet conveyed from the drying module 3000 between a heated upper belt unit and a lower belt unit. A duplex conveying portion of the fixing module 4000 is provided with the first reversing portion 4200 configured to reverse the front and back sides of the sheet.
The cooling module 5000 includes a plurality of cooling portions 5100 configured to cool a high-temperature sheet conveyed from the fixing module 4000. The cooling portion 5100 cools the sheet by taking an outside air into a cooling box by a fan to increase a pressure in the cooling box, and applying the air jetted from a nozzle formed in the conveyance guide to the sheet. The cooling portions 5100 are disposed on both sides of the conveyance path and cools the sheet from both sides.
The cooling module 5000 includes a conveyance path switching portion 5200. The conveyance path switching portion 5200 switches the conveyance path of the sheet according to a case of conveying the sheet to the reversing module 6000 and a case of conveying the sheet to a duplex conveyance path 1400 used for duplex printing. In the case of duplex printing, the sheet is conveyed to a conveyance path 5300 below the cooling module 5000 by the conveyance path switching portion 5200. The sheet is conveyed from the conveyance path 5300 to the duplex conveyance path 1400 in the feeding module 1000 via a conveyance path 4300 in the fixing module 4000, a conveyance path 3500 in the drying module 3000, and a conveyance path 2400 in the print module 2000. The sheet is conveyed again from the duplex conveyance path 1400 to the before-image-formation registration correcting portion 2100, the print belt unit 2200, and the recording portion 2300 of the print module 2000, and an ink image is formed on the sheet by the recording portion 2300.
The reversing module 6000 has a second reversing portion 6400. The second reversing portion 6400 reverses the front and back sides of the sheet to be conveyed. Thus, the reversing module 6000 can change the front and back orientations of the sheet to be discharged.
The discharge stacking module 7000 includes a top tray 7200 and a stacking portion 7500. The discharge stacking module 7000 stacks and aligns the sheets conveyed from the reversing module 6000 onto the top tray 7200 or the stacking portion 7500.
Next, the configuration of the feeding module 1000 will be described.
The storage 1100a is attached to a main body frame (feed frame) 1200 of the feeding module 1000 in a drawable manner. The storage 1100a is held by a left-side plate 1202 and a right-side plate 1203 provided on the main body frame 1200 as a holder through slide rails 1201. The storage 1100a is held by the main body frame 1200 so as to be movable in a front-rear direction FR between a closed position (mounting position) in which the storage 1100a is pushed toward a rear side of the main body frame 1200 and a pullout position in which the storage 1100a is pulled out in a pullout direction toward a front side of the main body frame 1200. In the embodiment, the front-rear direction FR is in the same direction as a sheet width direction orthogonal to the conveyance direction. In a state in which the storage 1100a is in the pullout position, sheets can be added to or replaced with other sheets in the storage 1100a.
The storage 1100a has two pullout positions. The first is a first pullout position for a user to replenish or replace the sheet. The second is a second pullout position for a service person to replace parts or perform maintenance.
Next, the configuration of the storage 1100a will be described.
The recording portion 2300 of the print module 2000 has a print head. The print gap, which is the clearance between the print head and the sheet, greatly affects the image quality. The condition in which the print gap disappears due to deformation of the sheet is called “head touch”. The head touch not only degrades the quality of the product but also can lead to the breakage of the print head. When the inkjet recording apparatus 10 is installed in a high humidity environment, a sheet before image formation in the storage 1100a absorbs moisture in the installation environment, and undulations occur. The deformation of the sheet due to the occurrence of undulations leads to reduction of the print gap. Therefore, even when the inkjet recording apparatus 10 is installed in the high humidity environment, it is necessary to seal the storage 1100a to a certain extent so that air in the high humidity environment does not flow into the storage 1100a to reduce the absorption of moisture in the installation environment by the sheet in the storage 1100a. Hereinafter, a sealing plate (front plate) 1152 configured to seal the storage 1100a will be described.
The storage 1100a is provided with the sealing plate (front plate) 1152. An exterior cover 1153 is fixed to a front side of the sealing plate 1152. A hermetic seal 1154 is fixed to a rear side of the sealing plate 1152. The feeding module 1000 is provided with a latch unit (1158, 1205 (
The sealing plate unit 1156 is integrally attached to the lateral registration adjustment plates 1151a and 1151b. For example, the sealing plate 1152 may include second engagement portions that are engageable with first engagement portions provided on the lateral registration adjustment plates 1151a and 1151b and may be integrally attached to the lateral registration adjustment plates 1151a and 1151b with the second engagement portion engaged with the first engagement portion. The sealing plate 1152 may be integrally attached to the lateral registration adjustment plates 1151a and 1151b by screws. The sealing plate 1152 is integrally held with the lateral registration adjustment plates 1151a and 1151b. Thus, the latch claws 1158 are integrally held with the lateral registration adjustment plates 1151a and 1151b and the sealing plate 1152.
Next, the structure of the sealing plate unit 1156 will be described.
The hermetic seal (sealing member) 1154 having elasticity is provided directly or through another member on an inner surface (sheet storage side sealing surface) 1152a, which is a rear side surface of the sealing plate 1152.
The packing 1167 is provided with two packing held portions 1169. The packing 1167 is held on the sealing plate 1152 by sandwiching the two packing held portions 1169. The packing 1167 is provided with an attracting face 1171. The packing 1167 is provided with a packing expansion and contraction portion 1172. The packing expansion and contraction portion 1172 may be an expansion and contraction portion which is expandable and contractable in a direction (front-rear direction FR) in which the storage 1100a is moved. As a shape of the packing expansion and contraction portion 1172 is changed, a distance between the packing held portion 1169 and the attracting face 1171 becomes variable within a range in which the shape of the packing expansion and contraction portion 1172 can be deformed. When the attracting face 1171 comes into contact with a member of a ferromagnetic material, the magnetic force of the magnet 1168 inside the packing 1167 acts as an attracting force, and the member of the ferromagnetic material is attracted to the attracting face 1171 of the packing 1167. The packing 1167 is extrusion-molded in the shape shown in the cross-sectional view of
The four (upper portion, lower portion, right portion, left portion) packing 1167 are welded at packing joints 1173 in a state in which the magnet 1168 is enclosed therein to form a hermetic seal 1154 connected into one. In the packing joint 1173, end portions of the packings 1167 are inclined at an angle of 45 degrees. The end portions of the two packings 1167 inclined at the angle of 45 degrees are welded to each other at the packing joint 1173. End portions of the magnets 1168 are inclined at the angle of 45 degrees to match the end portions of the packings 1167 inclined at the angle of 45 degrees at the packing joint 1173. However, the angle of the packing joint 1173 may be an angle other than 45 degrees.
Next, a method of fixing the hermetic seal 1154 will be described.
Next, the structure of the main body frame 1200 to which the hermetic seal 1154 is magnetically attracted and contacted will be described.
Next, an explanation will be given of a sealing state by the hermetic seal 1154 when the storage 1100a is put in the main body frame 1200.
In addition, when the storage 1100a is put in the main body frame 1200, the position of the sealing plate 1152 and the position of the frame sealing surface 1207 in the front-rear direction FR may be slightly deviated due to component tolerances and lateral registration adjustment. Even in this case, the amount of deviation in the distance between the sealing plate 1152 and the frame sealing surface 1207 can be absorbed within the range in which the shape of the packing expansion and contraction portion 1172 can be deformed. When the amount of deviation is absorbed, the shape of the packing expansion and contraction portion 1172 is deformed, but since the packing expansion and contraction portion 1172 is made of a very soft material such as PVC (or rubber), little reaction force is generated. Therefore, the hermetic seal 1154 gives little reaction force to contact portions such as the sealing plate 1152. As a result, the risk of generating a gap due to deformation of the sealing plate 1152 can be eliminated.
In the structure of the hermetic seal 1154 according to the present embodiment, the magnet 1168 is enclosed within the magnet enclosing portion 1170 inside the packing 1167. However, the packing 1167 itself may have magnetic force. Further, the method of fixing the packing 1167 to the sealing plate 1152 is not limited to the method in which the two packing held portions 1169 are sandwiched between metal plates (the sealing plate 1152, the packing holding plate (outer) 1174, the packing holding plate (inner) 1175). Another method may be used, such as fixing the packing 1167 to the sealing plate 1152 with double-sided adhesive tape. The fixing member configured to fix the hermetic seal 1154 to the inner surface (second sealing surface) 1152a of the sealing plate 1152 is not limited to the double-sided adhesive tape but may be another fixing member such as an adhesive. As described above, the structure of the hermetic seal 1154 using the magnetic force has been explained. However, the hermetic seal 1154 may not have the magnetic force. For example, the hermetic seal 1154 may be an elastic member such as rubber or a foam sponge.
At the closed position in which the storage 1100a is pushed into the main body frame 1200, the hermetic seal 1154 contacts the frame sealing surface (feed frame side sealing surface) 1207 provided in the main body frame 1200. The inner surface (second sealing surface) 1152a of the sealing plate 1152 is disposed opposite to the frame sealing surface (first sealing surface) 1207 which is a front surface of the main body frame 1200. In a state in which the hermetic seal 1154 is compressed between the frame sealing surface (first sealing surface) 1207 which is the front surface of the main body frame 1200 and the inner surface 1152a of the sealing plate 1152 by a predetermined amount, the hermetic seal 1154 seals between the storage 1100a and the outside air.
The latch claws (second positioning members) 1158 and the inner surface (second sealing surface) 1152a of the sealing plate 1152 constitute a second unit U2 (
In the embodiment, the hermetic seal 1154 is fixed to the inner surface 1152a of the sealing plate 1152. However, the hermetic seal 1154 may be fixed to the frame sealing surface 1207 of the main body frame 1200. However, in general, the hermetic seal 1154 needs a certain size in the height direction. The size of the hermetic seal 1154 in the height direction is often larger than the size in the height direction of the frame sealing surface 1207 to which the hermetic seal 1154 is attracted and contacts. In the embodiment, the hermetic seal 1154 is fixed to the sealing plate 1152. Therefore, the hermetic seal 1154 does not interfere with the components fixed to the main body frame 1200 when the storage 1100a is pulled out. On the other hand, the frame sealing surface 1207 is often smaller than the hermetic seal 1154 in the height direction. Therefore, in a case in which the hermetic seal 1154 is fixed to the frame sealing surface 1207, the hermetic seal 1154 may interfere with the internal components of the storage 1100a. Therefore, compared with the case in which the relationship is reversed (the case in which the hermetic seal 1154 is fixed to the frame sealing surface 1207 of the main body frame 1200), the present embodiment has a configuration in which the clearance margin is easily obtained against the interference of the internal components of the storage 1100a.
The hermetic seal 1154 may be attached to one sealing surface of the inner surface 1152a and the frame sealing surface 1207, so long as the hermetic seal 1154 can contact the other sealing surface of the inner surface 1152a and the frame sealing surface 1207 when the storage 1100a is in the closed position. In the closed position in which the storage 1100a is pushed into the main body frame 1200, the hermetic seal 1154 seals between the inner surface 1152a and the frame sealing surface 1207.
Next, the structure of the storage frame 1110 will be described.
The configuration of the operation portion 1125 configured to operate the pair of side guide portions 1121 and 1122 will now be described. The pair of side guide portions 1121 and 1122 are provided with rack members 1123 and 1124 extending parallel to the front-rear direction FR. The rack members 1123 and 1124 are held by the storage frame 1110 so as to be movable in the front-rear direction FR. The rack members 1123 and 1124 have rack teeth 1123a and 1124a engraved on side faces facing each other. The rack teeth 1123a and 1124a are engaged with a gear 1126 disposed between the rack members 1123 and 1124. When one of the pair of side guide portions 1121 and 1122 is moved in one direction in the front-rear direction FR, a force is transmitted through the gear 1126 to the other of the pair of side guide portions 1121 and 1122. The other of the pair of side guide portions 1121 and 1122 is moved in the other direction opposite to the one direction by the same distance. That is, the gear 1126 as an interlocking unit interlocks the pair of side guide portions 1121 and 1122 so that the pair of side guide portions 1121 and 1122 move in the opposite directions by the same distance.
The operation portion 1125, which is manually rotatable, is provided on an upper portion of the storage frame 1110 on the front side of the storage 1100a. The operation portion 1125 is coaxially connected to the gear 1126 by a rotation shaft 1127. When the user operates the operation portion 1125, the gear 1126 rotates, and the pair of side guide portions 1121 and 1122 move in the front-rear direction FR through the rack members 1123 and 1124. As a result, a width between the pair of side guide portions 1121 and 1122 in the front-rear direction FR can be widened or narrowed according to a width of a sheet stacked in the storage 1100a.
The lateral registration adjustment plates 1151a and 1151b provided on the right-side portion 1110a and the left-side portion 1110b, respectively, of the storage frame 1110 can be attached to the storage frame 1110 by adjusting their positions in the front-rear direction FR. The lateral registration adjustment plates 1151a and 1151b are each provided with two elongated holes (gaps) 1114 elongated in the front-rear direction FR. The two elongated holes 1114 in each of the lateral registration adjustment plates 1151a and 1151b are fitted into the lateral registration adjustment pins 1157 provided in each of the right-side portion 1110a and the left-side portion 1110b. As a result, the positions of the lateral registration adjustment plates 1151a and 1151b can be adjusted in the front-rear direction FR of the feeding module 1000 with respect to the storage frame 1110. The lateral registration adjustment plates 1151a and 1151b are fixed to the right-side portion 1110a and the left-side portion 1110b respectively by lateral registration adjustment plate screws 1166 after their positions in the front-rear direction FR have been adjusted.
Next, the configuration of the main body frame 1200 of the feeding module 1000 will be described.
In the embodiment, the latch claws 1158 having the hook shape are provided on the sealing plate 1152, and the storage positioning rollers 1205 having the substantially cylindrical shape are provided on the main body frame 1200. However, the latch claws having the hook shape may be provided on the main body frame 1200 as the feed frame side positioning portion, and the storage positioning rollers having the substantially cylindrical shape may be provided on the sealing plate 1152 as the front plate side positioning portion.
In the case in which the inkjet recording apparatus 10 as the image forming apparatus is installed in the high humidity environment, it is desirable to by seal the storage 1100a to prevent the air in the high humidity environment from flowing into the storage 1100a to reduce the absorption of moisture in the installation environment by the sheets stored in the storage 1100a. On the other hand, the storage 1100a is pulled out when a user refills the sheets. Therefore, in the present embodiment, when the storage 1100a is in the closed position in which the storage 1100a is pushed into the main body frame 1200, the storage 1100a is sealed by the hermetic seal 1154 between the storage 1100a and the main body frame 1200.
Here, it is assumed that the position of the storage 1100a is simply adjusted in the front-rear direction FR in order to correct the deviation in the lateral registration position of the position of the sheet stored in the storage 1100a. Then, there is an issue that an amount of compression of the hermetic seal 1154 provided between the storage 1100a and the main body frame 1200 changes. If the amount of compression of the hermetic seal 1154 changes, it may lead to a hermetic failure. For example, if the amount of compression of the hermetic seal 1154 is insufficient, an insufficient sealing between the storage 1100a and the main body frame 1200 occurs. Conversely, if the hermetic seal 1154 is compressed too much, a deterioration of the hermetic seal 1154 occurs. As a result, water vapor may flow from the high humidity environment in which the inkjet recording apparatus 10 is installed, into the storage 1100a, causing sheets to undulate. Therefore, in the embodiment, the lateral registration adjustment can be performed without changing the amount of compression of the hermetic seal 1154, as described below.
The first unit U1 including the storage frame 1110 and a pair of side guide portions 1121 and 1122 is configured so as to change its relative position to the second unit U2 including the latch claws 1158 and the inner surface 1152a of the sealing plate 1152. The lateral registration adjustment plates (support members) 1151a and 1151b are attached to the storage frame 1110 so as to adjust their positions in the front-rear direction FR relative to the first unit U1. Thus, the relative position of the first unit U1 with respect to the second unit U2 is changeable. Next, the adjustment mechanism of the lateral registration adjustment plate 1151a will be described.
Since the exterior cover 1153 (
In the above description, the configuration in which the position of the sealing plate 1152 and the latch claws 1158 with respect to the storage frame 1110 are adjusted through the lateral registration adjustment plates (support members) 1151a and 1151b is exemplified. However, since it is desirable to be able to adjust the lateral registration of the sheet supported by the storage frame 1110 with respect to the main body frame 1200, the following configuration may be used, for example. That is, the pair of side guide portions 1121 and 1122 and the gear 1126 are assumed to be a side regulation unit (first unit) (
Referring to
According to the present embodiment, the clearance between the sealing plate 1152 and the main body frame 1200 can be kept constant while enabling the lateral registration adjustment of the sheet supported by the storage frame 1110 with respect to the main body frame 1200. As a result, the amount of compression of the hermetic seal 1154 can be stably held at a predetermined amount, so that the sealing between the sealing plate 1152 and the main body frame 1200 can be maintained. Therefore, even when the feeding module 1000 is installed in a high humidity environment, the sheet undulations can be suppressed. According to the embodiment, while the position of the storage frame 1110 with respect to the main body frame 1200 can be adjusted, the position of the sealing plate 1152 with respect to the main body frame 1200 can be kept constant. According to the embodiment, while the relative position between the first unit U1 and the second unit U2 is changeable, the distance between the frame sealing surface 1207 and the inner surface 1152a of the sealing plate 1152 when the storage 1100a is in the closed position can be kept constant. Therefore, according to the embodiment, the moisture absorption of the sheet in the feeding module 1000 can be reduced. Although the inkjet recording apparatus 10 using the inkjet system has been described as an example of an image forming apparatus, the image forming apparatus according to the present embodiment may be an electrophotographic image forming apparatus using an electrophotographic system.
While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2023-078120, filed May 10, 2023, and Japanese Patent Application No. 2023-132890, filed Aug. 17, 2023, which are hereby incorporated by reference herein in their entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-078120 | May 2023 | JP | national |
| 2023-132890 | Aug 2023 | JP | national |
