SHEET FEEDING APPARATUS AND IMAGE FORMING SYSTEM

Abstract

A sheet feeding apparatus includes an accommodating unit, and a conveyance unit. The conveyance unit includes a first guide member, a second guide member, walls on both sides, a conveyance roller, and a first cover. The walls on both sides are arranged on both sides of the first guide member and the second guide member in a width direction perpendicular to a sheet conveyance direction. Together with the first guide member and the second guide member, the walls on both sides forms a space of a conveyance path through which a sheet is conveyed. The conveyance roller is disposed to project toward the conveyance path via a first opening of the first guide member and conveys the sheet in the conveyance path. The first cover encloses the space of the conveyance path in such a manner that the first cover covers the first opening and the conveyance roller.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

This disclosure relates to a sheet feeding apparatus feeding a stored sheet, and an image forming system utilizing this sheet feeding apparatus.

Description of the Related Art

In recent years, the printing industry is seeking industrial inkjet printers capable of achieving high productivity and high quality deliverables. While, in the industrial inkjet printers, printing is performed on a sheet by a print head, image quality is largely affected by a print gap that is clearance between the print head and the sheet. Further, a state in which the print gap is eliminated due to such as the deformation of the sheet is referred to as a head-touch. There is a risk that such a state leads to not only a decrease in the quality of deliverables but also inflicts damage on the print head.

Here, in a case where an area around the printer becomes a highly humid environment, the sheet stored in a sheet feeding apparatus before printing is more likely to develop waviness by absorbing moisture in an installation environment. Deformation caused by the waviness created in the sheet may lead to a risk of decreasing the print gap. Therefore, it is desired that, even in a case where the area around the printer becomes the highly humid environment, the sheet stored in the sheet feeding apparatuses remains protected against the moisture absorption. For a purpose of achieving this, for example, a sheet cassette which includes a moisture proof structure at every contact portion where a cassette casing is in contact with covers that enclose an interior of the cassette casing is suggested (refer to Japanese Patent Laid-open No. H9-132330).

However, in the sheet cassette described in Japanese Patent Laid-open No. H9-132330 mentioned above, a guide portion guiding the sheet stored in the sheet cassette to an image forming unit is disposed, and, sometimes, a conveyance roller conveying the sheet is disposed in adjacent to the sheet cassette. In this case, since an opening is formed in the guide portion so as to allow the conveyance roller to directly engage with the sheet, there is a possibility that airflow may occur between the inside and outside of the cassette because of the opening, and moisture resistance within the interior of the cassette casing may not be maintained.

The purpose of this disclosure is to provide a sheet feeding apparatus and an image forming system capable of improving the moisture resistance with respect to the sheet that is stored.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, a sheet feeding apparatus includes an accommodating unit including a case forming an enclosed accommodating space configured to accommodate a sheet, a sheet discharge port formed in a part of the case and through which the sheet is discharged outside from the case, and a sheet feed portion configured to feed the sheet accommodated in the case to an outside of the case through the sheet discharge port, and a conveyance unit connected to the sheet discharge port of the accommodating unit and configured to convey the sheet discharged from the sheet discharge port. The conveyance unit includes a first guide member, a second guide member, walls on both sides, a conveyance roller, and a first cover. The first guide member includes a first opening. The second guide member is arranged to face the first guide member. The walls on both sides are arranged on both sides of the first guide member and the second guide member in a width direction perpendicular to a sheet conveyance direction. Together with the first guide member and the second guide member, the walls on both sides forms a space of a conveyance path through which the sheet is conveyed. The conveyance roller is disposed to project toward the conveyance path via the first opening and configured to convey the sheet in the conveyance path. The first cover encloses the space of the conveyance path in such a manner that the first cover covers the first opening and the conveyance roller.

According to a second aspect of the present invention, a sheet feeding apparatus includes an accommodating unit including a case forming an enclosed accommodating space configured to accommodate a sheet, a sheet discharge port formed in a part of the case and through which the sheet is discharged outside from the case, and a sheet feed portion configured to feed the sheet accommodated in the case to an outside of the case through the sheet discharge port, and a conveyance unit connected to the sheet discharge port of the accommodating unit and configured to convey the sheet discharged from the sheet discharge port. The conveyance unit includes a first guide member, a second guide member, walls on both sides, a detection portion, and a cover. The first guide member includes an opening. The second guide member is arranged to face the first guide member. The walls on both sides are arranged on both sides of the first guide member and the second guide member in a width direction perpendicular to a sheet conveyance direction. Together with the first guide member and the second guide member, the walls on both sides forms a space of a conveyance path through which the sheet is conveyed. The detection portion is configured to detect the sheet conveyed in the conveyance path via the opening. The cover encloses the space of the conveyance path in such a manner that the cover covers the opening and the detection portion.

According to a third aspect of the present invention, an image forming system includes the sheet feeding apparatus, and an image forming apparatus forming an image on the sheet fed from the sheet feeding apparatus.

Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating an image forming system of the present embodiment.

FIG. 2 is a perspective view illustrating a feed module of the present embodiment.

FIG. 3 is a perspective view illustrating a case of the present embodiment.

FIG. 4 is a cross-sectional view illustrating the case taken along the line A-A of FIG. 3.

FIG. 5 is a detail cross-sectional view of a section B of FIG. 4.

FIG. 6 is a perspective view illustrating a mounting configuration of a conveyance unit of the present embodiment.

FIG. 7 is a detail cross-sectional view of a section C of FIG. 6.

FIG. 8 is a perspective view illustrating a mounting configuration of a sheet sensor of a variant example.

FIG. 9 is a detail cross-sectional view of a section D of FIG. 8.

FIG. 10 is a perspective view illustrating the mounting configuration of the sheet sensor of the variant example.

FIG. 11 is a cross-sectional view illustrating a mounting configuration of a sheet sensor of another variant example.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, using drawings, the present embodiment will be described. In the present embodiment, a case where an image forming system is applied to an inkjet recording system 1 will be described. FIG. 1 is a schematic view illustrating an example of a schematic configuration of the inkjet recording system 1. This inkjet recording system 1 is a single wafer type inkjet recording system that forms an ink image on a sheet S by using two liquids: a reaction liquid and ink. As illustrated in FIG. 1, the inkjet recording system 1 is constituted from a feed module 100, a print module 200, a drying module 300, a fixing module 400, a cooling module 500, a reverse module 600, and a sheet discharge module 700. The sheet S, shaped in a cut sheet and fed from the feed module 100, is conveyed along a conveyance path, and, after having been processed in each module, is discharged by the sheet discharge module 700.

The feed module 100 that is an example of a sheet feeding apparatus includes three storage compartments 110a, 110b, and 110c storing the sheet S. Each of the storage compartments 110a, 110b, and 110c is drawable toward the front side of the apparatus. In each of the storage compartments 110a, 110b, and 110c, the sheet S is fed by a separation belt and a conveyance roller one sheet at a time, and is conveyed to the print module 200. To be noted, the feed module 100 is not limited to including the three storage compartments 110a, 110b, and 110c, and the feed module 100 may include one, or two, or equal to or more than four storage compartments.

The print module 200 that is an example of an image forming apparatus includes a pre-image forming registration correction unit, not shown, a print belt unit 220, and a recording unit 230. The skew and a position of the sheet S that has been conveyed from the feed module 100 are corrected by the pre-image forming registration correction unit, and the sheet S is conveyed to the print belt unit 220. The recording unit 230 is located at a position facing the print belt unit 220 with respect to the conveyance path. The recording unit 230 is a sheet processing unit that forms an image on the sheet S by performing recording processing (printing) with respect to the sheet S by recording heads from above. The plurality of recording heads are arranged along a sheet conveyance direction. In the present embodiment, the recording unit 230 includes total of five line-type recording heads, corresponding to four colors: yellow (Y), magenta (M), cyan (C), and black (K), along with a recording head for the reaction liquid in addition to the four colors. To be noted, the variety of colors and number of the recording heads are not respectively limited to four and five. To an inkjet method, methods using such as a heating element, a piezoelectric element, a micro electromechanical system (MEMS) element can be adopted. The ink of each color is supplied from an ink tank, not shown, to each of the recording heads through an ink tube. By being adsorptively conveyed by the print belt unit 220, the sheet S printed in the recording unit 230 is conveyed while maintaining clearance with the recording heads. The sheet S printed in the recording unit 230 is detected for the misalignment and the color density of the image formed on the sheet S by an inline scanner, not shown, located downstream of the recording unit in the sheet conveyance direction. Detection results are utilized for the correction of the printed image.

The drying module 300 includes a decoupling portion 320, a drying belt unit 330, and a warm air blowing portion 340, and improves the fixation of the ink to the sheet S by reducing a liquid content in the ink applied onto the sheet S in the recording unit 230 of the print module 200. The sheet S printed in the recording unit 230 of the print module 200 is conveyed to the decoupling portion 320 located on an upstream side of the drying module 300 in the sheet conveyance direction. In the decoupling portion 320, it is possible to convey the sheet S through the pressure of airflow from above and the friction of a belt. By softly securing the sheet S on the belt during conveyance, the displacement of the sheet S on the print belt unit 220, where the ink image is formed, is prevented. The drying belt unit 330 and the warm air blowing portion 340 are respectively arranged below and above the belt in a manner facing each other across the belt. The sheet S conveyed from the decoupling portion 320 is adsorptively conveyed by the drying belt unit 330, and, at the same time, an ink application surface of the sheet S is dried by receiving hot air from the warm air blowing portion 340. To be noted, as a method of drying, instead of applying the hot air, it is acceptable to irradiate the surface of the sheet S with electromagnetic waves (such as ultraviolet or infrared rays), or it is acceptable to utilize combined methods that involve conductive heat transfer through contact with a heating body.

The fixing module 400 includes a fixing belt unit 410. The fixing belt unit 410 includes an upper belt unit and a lower belt unit, and can fix the ink on the sheet S by passing the sheet S conveyed from the drying module 300 through a gap between the heated upper belt unit and the lower belt unit.

The cooling module 500 includes a plurality of cooling units 510, and cools a high temperature sheet S conveyed from the fixing module 400. By drawing outside air into cooling boxes with fans to increase the internal pressure of the cooling boxes, the cooling unit 510 cools the sheet S by guiding a flow of the air emitted through nozzles formed in a conveyance guide. The cooling units 510 are arranged on both upper and lower sides, and cool the sheet S from both surfaces.

Further, the cooling module 500 includes a conveyance path switching portion, and can switch the conveyance path of the sheet S depending on whether the sheet is conveyed to the reverse module 600 or to a duplex conveyance path used during duplex printing. During the duplex printing, the sheet S is conveyed through a conveyance path located in a lower section of the cooling module 500. In this case, from the cooling module 500, the sheet S is further conveyed along duplex conveyance paths of the fixing, drying, print, and feed modules 400, 300, 200, and 100. A first reverse portion 420 reversing the front and back surfaces of the sheet S is disposed in the duplex conveyance path of the fixing module 400. Then, the sheet S is again conveyed from the feed module 100 to the pre-image forming registration correction unit of the print module 200, the print belt unit 220, and the recording unit 230, and is printed in the recording unit 230.

The reverse module 600 includes a second switching portion 640, and can reverse the front and back surfaces of the sheet S that is discharged. The sheet discharge module 700 includes a top tray 720 and a supporting portion 750, and aligns and stacks the sheet S conveyed from the reverse module 600.

Feed Module

Next, a configuration of the feed module 100 will be described. As illustrated in FIG. 3, the feed module 100 includes a storage unit 140 serving as an accommodating unit and a conveyance unit 170. FIG. 2 is a schematic diagram illustrating a state in which the storage compartment 110a of the feed module 100 is drawn out. The storage compartment 110a is drawably held with respect to a main body of the feed module 100 via slide rails 121. To be noted, since, in the present embodiment, all the storage compartments 110a, 110b, and 110c are uniformly configured, hereinafter, a configuration of an area around the storage compartment 110a will be exclusively described. To be noted, while, in the present embodiment, a case where all the storage compartments 110a, 110b, and 110c are uniformly configured is described, it is not limited to this. For example, a maximum stacking number and the height of the sheets may be different in each of the storage compartments 110a to 110c.

Storage Unit

An enclosed configuration of the storage unit 140, in particular, the storage compartment 110a will be described in detail. FIG. 3 is an overall perspective view illustrating a configuration of a case 141 that incorporates the storage compartment 110a within a predetermined space, and FIG. 4 is a cross-sectional view illustrating a state in which the case 141 is cut along the line A-A in FIG. 3. The storage unit 140 includes the case 141, a sheet discharge port 142, and a sheet feed unit 160. The case 141 forms an enclosed accommodating space for accommodating a sheet bundle or sheet. In the present embodiment, the case 141 is constituted from an enclosed frame 150 and a storage compartment cover 153.

The enclosed frame 150 is configured to cover the storage compartment 110a mounted to the main body of the feed module 100 on five sides, which include the top, bottom, rear, right, and left sides while excluding the front side among six sides. When mounting the storage compartment 110a, the storage cover 153 covers the front side of the sealed frame 150, and all the six sides of the enclosed frame 150 are covered. Thereby, moisture resistance within the case 141 is ensured, and the absorption of moisture by the sheet stacked and stored in the storage compartment 110a is prevented.

The sheet discharge port 142 is formed in a part of the case 141, and the sheet is discharged outside through the sheet discharge port 142. The sheet feed unit 160 is an example of a sheet feed portion, and feeds the sheet stored in the case 141 from the sheet discharge port 142 to the outside of the case 141. The sheet feed unit 160 is arranged inside of the enclosed frame 150, and conveys the sheet stacked in an interior of the storge compartment 101a while separating the sheet into one sheet at a time. FIG. 5 is a detail view of a section B in FIG. 4. The sheet feed unit 160 includes a separation belt 161, belt rollers 162, a drive motor, not shown, and a suction fan, not shown. The separation belt 161 is stretched by the belt rollers 162, and is rotated in the sheet conveyance direction by a power transmitted by the drive motor, not shown. The suction fan, not shown, is disposed above the separation belt 161, and the sheet feed unit 160 conveys the sheet stacked in the interior of the storage compartment 110a while separating the sheet into one sheet at a time by adsorptively suctioning the sheet onto the separation belt 161.

Conveyance Unit

FIG. 6 is a partial perspective view illustrating a mounting configuration of an upper roller cover 183. As illustrated in FIGS. 5 and 6, the conveyance unit 170 is connected to the sheet discharge port 142 of the storge unit 140, and conveys the sheet discharged from the sheet discharge port 142. The conveyance unit 170 includes an upper conveyance guide 181, a lower conveyance guide 191, a front side plate 173, a rear side plate 174, drive rollers 180, and driven rollers 190. The upper conveyance guide 181 that is an example of a first guide member, and the lower conveyance guide 191 that is an example of a second guide member are arranged to face each other. The front and rear side plates 173 and 174 are examples of walls on both sides, and are arranged on both sides in a width direction perpendicular to a sheet conveyance direction of the upper and lower conveyance guides 181 and 191. The front and rear side plates 173 and 174 form a space of the conveyance path for the sheet together with the upper and lower conveyance guides 181 and 191.

Roller opening portions 182 that are examples of a first opening are formed in the upper conveyance guide 181. Roller opening portions 192 that are examples of a third opening are formed in the lower conveyance guide 191.

The drive rollers 180 are examples of a conveyance roller and a first conveyance roller, and are rotatably driven by a drive unit 184 (refer to FIG. 7) including a drive motor, not shown, in the sheet conveyance direction. The drive rollers 180 are disposed to project toward the conveyance path via the roller opening portions 182, and convey the sheet in the conveyance path. The conveyance unit 170 includes a rotation shaft 180a rotatably supporting the drive rollers 180. The front and rear side plates 173 and 174 are extended in a direction from the lower conveyance guide 191 toward the upper conveyance guide 181 and support the rotation shaft 180a rotatably and hermetically.

Each of the driven rollers 190 is an example of a second conveyance roller, and, by being disposed to project toward the conveyance path via each of roller opening portions 192 formed in the lower conveyance guide 191 and being rotatably driven by each of the drive rollers 180, forms a nip nipping the sheet with each of the drive rollers 180. The conveyance unit 170 includes a rotation shaft 190a rotatably supporting the driven rollers 190. The front and rear side plates 173 and 174 are extended in a direction from the upper conveyance guide 181 toward the lower conveyance guide 191 and support the rotation shaft 190a rotatably and hermetically.

In the present embodiment, an upper roller cover 183 covering the roller opening portions 182 is mounted to the conveyance unit 170. That is, the upper roller cover 183 is an example of a first cover, and encloses the space of the conveyance path in such a manner that the upper roller cover 183 covers the roller opening portions 182, the drive rollers 180, and the rotation shaft 180a. Further, a lower roller cover 193 covering the roller opening portions 192 is mounted to the conveyance unit 170. That is, the lower roller cover 193 is an example of a third cover, and encloses the space of the conveyance path in such a manner that the lower roller cover 193 covers the roller opening portions 192, the driven rollers 190, and the rotation shaft 190a.

By mounting the upper and lower roller covers 183 and 193, it is possible to prevent the outside air from flowing into an interior of the case 141 from the roller opening portions 182 and 192. Thereby, a minimal opening gap G formed by the upper and lower conveyance guides 181 and 191, through which the sheet passes, becomes an opening gap through which the outside air adjacent to the sheet discharge port 142 of the case 141 can pass. By extending this opening gap G through which the outside air can pass, from the sheet discharge port 142 to conveyance sections 171 and 172, it is possible to minimize an exchange of the outside air in the interior of the case 141, and is possible to ensure the moisture resistance within the interior of the case 141. In cases, such as a case of a higher humidity installation environment, where the moisture resistance within the interior of the case 141 cannot be sufficiently ensured, the moisture resistance is preferably further improved by extending the length of the conveyance sections 171 and 172.

In the present embodiment, the upper roller cover 183 includes a first cover portion 183a covering the drive rollers 180 and a second cover portion 183b covering the rotation shaft 180a. The first cover portion 183a and the second cover portion 183b are formed in sectionally circular arc shapes. A diameter of the second cover portion 183b is set to be smaller than a diameter of the first cover portion 183a. Thereby, air resistance inside of the upper roller cover 183 in an axial direction is increased so as to further improve the moisture resistance.

FIG. 7 is a detail view of a section C in FIG. 6. The upper roller cover 183 is fastened with screws 185 and 186 (refer to FIG. 6) with respect to the upper conveyance guide 181. In the present embodiment, the upper roller cover 183 not only covers the roller opening portions 182 but also covers, for example, such as a gap 174a created between the rear side plate 174, which supports the upper conveyance guide 181, and the upper conveyance guide 181. That is, at a trailing edge of the upper conveyance guide 181, a curved connecting portion 181a is formed, and the connecting portion 181a is connected to the rear side plate 174 to maintain airtightness and the moisture resistance. With respect to this, since the gap 174a is formed at a part between the trailing edge of the upper conveyance guide 181 and the rear side plate 174, such a portion that cannot maintain the airtightness and the moisture resistance is covered by the upper roller cover 183 to enclose the space of the conveyance path. Further, when the upper roller cover 183 is mounted, the moisture resistance is enhanced by interposing sealing member such as a sponge 175 or urethane at contact area where the upper conveyance guide 181 and the front and rear side plates 173 and 174. To be noted, while, in the present embodiment, the upper roller cover 183 is configured to cover the gap 174a, it is not limited to this. For example, it is acceptable that the upper roller cover 183 covers the roller opening portions 182 and the drive rollers 180, but does not cover the gap 174a. Even in this case, in comparison with a case of not disposing the upper roller cover 183, it is possible to suppress the inflow of the outside air into the interior of the case 141.

As described above, according to the feed module 100 of the present embodiment, the upper roller cover 183 encloses the space of the conveyance path by covering the roller opening portions 182, the drive rollers 180, and the rotation shaft 180a. Therefore, by suppressing ventilation between the inside and outside of the case 141, it is possible to improve the moisture resistance with respect to the sheet stored in the feed module 100. As described above, according to the present embodiment, it is possible to ensure the moisture resistance within the case 141 even in a case where the drive and driven rollers 180 and 190 are arranged in adjacent to the sheet discharge port 142 of the case 141, and, thereby, it is possible to suppress the waviness of the sheet.

Here, for a purpose of dehumidifying the internal of the casing 141, it is conceivable to dispose a humidity regulation unit constituted from a dehumidifying heater and a humidifier and maintain the humidity in the interior of the case 141 within a predetermined range. However, in this configuration, the size of the apparatus is increased by the disposition of the humidity regulation unit. In contrast, according to the present embodiment, it is possible to achieve moisture prevention within the interior of the case 141 without causing an increase in the size of the apparatus.

While, in the present embodiment, the conveyance unit 170 includes the drive and driven rollers 180 and 190, it is not limited to this. For example, it is acceptable that the conveyance unit includes the drive rollers 180, but does not include the driven rollers 190. In this case, the sheet is conveyed by the drive of the drive rollers 180. Further, since the driven rollers 190 are not disposed, it is not necessary to form the roller opening portions 192 in the lower conveyance guide 191, and it is possible to eliminate the lower roller cover 193 while suppressing the ventilation between the inside and outside of the case 141.

To be noted, while, in the embodiment described above, a sheet sensor is not disposed in the conveyance unit 170, the sheet sensor may be disposed in the conveyance unit 170. Using FIGS. 8 to 10, a configuration in which a sheet sensor 176 is disposed in the conveyance unit 170 will be described. FIG. 8 is a perspective view illustrating a mounting configuration of the upper roller cover 183, the sheet sensor 176, and a sensor cover 187 in a case where the drive rollers 180 (refer to FIG. 6) and the sheet sensor 176 are arranged in the conveyance sections 171 and 172 (refer to FIG. 5). FIG. 9 is a detail view of a section D in FIG. 8, and FIG. 10 is a perspective view illustrating a mounted state of the sensor cover 187.

As illustrated in FIG. 9, a sensor opening portion 181b that is an example of a second opening, which is different from the roller opening portions 182 and communicates with the conveyance path, is formed in the upper conveyance guide 181. In the upper roller cover 183, a sensor opening portion 183c that is an example of a sensor opening is formed at a position facing the sensor opening portion 181b. The sheet sensor 176 is fastened with a screw 176a to an outer side of the upper roller cover 183 so as to enable the sheet sensor 176 to detect the sheet in the conveyance path via the sensor opening portions 181b and 181c. That is, the sheet sensor 176 is an example of a detection unit, and detects the sheet conveyed in the conveyance path via the sensor opening portions 181b and 181c.

Further, the sensor cover 187 is an example of a second cover, and encloses the space of the conveyance path by covering each of the sensor opening portions 181b and 181c, and the sheet sensor 176. The sensor cover 187 is fastened with a screw 187a to the upper roller cover 183. Thereby, it is possible to achieve the moisture prevention within the interior of the case 141 while disposing both the drive roller 180 and the sheet sensor 176. To be noted, while here the sheet sensor 176 is mounted to the upper roller cover 183, it is not limited to this, and it is acceptable to mount the sheet sensor 176 to the sensor cover 187. Further, while here the sheet sensor 176 is disposed on a side of the drive rollers 180, it is not limited to this, and it is acceptable to dispose the sheet sensor 176 on a side of the driven rollers 190.

Further, while, in the embodiment described above, the drive and driven rollers 180 and 190 are disposed in the conveyance unit 170, it is not limited to this, and, for example, it is acceptable to dispose a sheet sensor 276 in the conveyance unit 170 while not including the drive and driven rollers 180 and 190. In this case, for example, as illustrated in FIG. 11, an opening 282 is formed in an upper conveyance guide 281, and the sheet sensor 276, serving as a detection unit detecting the sheet in the conveyance path via the opening 282, is disposed. Further, a sensor cover 283 enclosing the space of the conveyance path by covering the opening 282 and the sheet sensor 276 is disposed. In this case, also, by suppressing the ventilation between the inside and outside of the case 141, it is possible to improve the moisture resistance with respect to the sheet stored in the feed module 100.

Further, while, in the embodiment described above, the rotation shafts 180a and 190a are supported by the walls on both sides, it is not limited to this. For example, by providing the driven roller 190 with a rotation shaft that is slightly longer than the roller, it is acceptable to support the rotation shafts of the driven rollers 190 by bearings disposed in the lower conveyance guide 191. In this case, the lower roller cover 193 can enclose the space of the conveyance path with the lower conveyance guide 191 in such a manner that the lower roller cover 193 covers the roller opening portions 192, the driven rollers 190, and the rotation shafts.

Further, while, in the embodiment described above, the sheet feeding apparatus is applied to the inkjet recording system 1 of an inkjet recording method, it is not limited to this, and it is acceptable to apply the sheet feeding apparatus to an image forming system of an electrophotographic system.

According to this disclosure, it is possible to improve the moisture resistance with respect to the sheet stored in the sheet feeding apparatus.

Other Embodiments

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention 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. 2023-066305, filed Apr. 14, 2023 which is hereby incorporated by reference herein in its entirety.

Claims

1. A sheet feeding apparatus comprising: an accommodating unit including a case forming an enclosed accommodating space configured to accommodate a sheet, a sheet discharge port formed in a part of the case and through which the sheet is discharged outside from the case, and a sheet feed portion configured to feed the sheet accommodated in the case to an outside of the case through the sheet discharge port; anda conveyance unit connected to the sheet discharge port of the accommodating unit and configured to convey the sheet discharged from the sheet discharge port,wherein the conveyance unit includes a first guide member, a second guide member, walls on both sides, a conveyance roller, and a first cover,wherein the first guide member includes a first opening,wherein the second guide member is arranged to face the first guide member,wherein the walls on both sides are arranged on both sides of the first guide member and the second guide member in a width direction perpendicular to a sheet conveyance direction,wherein, together with the first guide member and the second guide member, the walls on both sides forms a space of a conveyance path through which the sheet is conveyed,wherein the conveyance roller is disposed to project toward the conveyance path via the first opening and configured to convey the sheet in the conveyance path, andwherein the first cover encloses the space of the conveyance path in such a manner that the first cover covers the first opening and the conveyance roller.

2. The sheet feeding apparatus according to claim 1, wherein the conveyance unit includes a rotation shaft configured to rotatably support the conveyance roller,wherein the walls on both sides are extended in a direction from the second guide member toward the first guide member and support the rotation shaft rotatably and hermetically, andwherein the first cover encloses the space of the conveyance path with the first guide member and the walls on both sides in such a manner that the first cover covers the first opening, the conveyance roller, and the rotation shaft.

3. The sheet feeding apparatus according to claim 2, wherein the first cover includes a first cover portion covering the conveyance roller and formed in sectionally circular arc shape, and a second cover portion covering the rotation shaft and formed in sectionally circular arc shape, andwherein a diameter of the second cover portion is smaller than a diameter of the first cover portion.

4. The sheet feeding apparatus according to claim 1, wherein the first guide member includes a second opening different from the first opening and configured to communicate with the conveyance path,wherein the conveyance unit includes a detection portion and a second cover,wherein the detection portion is configured to detect the sheet conveyed in the conveyance path via the second opening, andwherein the second cover encloses the space of the conveyance path in such a manner that the second cover covers the second opening and the detection portion.

5. The sheet feeding apparatus according to claim 4, wherein the first cover includes a sensor opening that faces the second opening,wherein the detection portion is disposed on an outer side of the first cover and configured to detect the sheet conveyed in the conveyance path via the second opening and the sensor opening, andwherein the second cover encloses the space of the conveyance path in such a manner that the second cover covers the second opening, the sensor opening, and the detection portion.

6. The sheet feeding apparatus according to claim 1, wherein the conveyance roller is a first conveyance roller,wherein the conveyance unit includes a second conveyance roller and a third cover,wherein, the second conveyance roller is disposed to project toward the conveyance path via a third opening formed in the second guide member and configured to form a nip nipping the sheet with the first conveyance roller, andwherein the third cover encloses the space of the conveyance path in such a manner that the third cover covers the third opening and the second conveyance roller.

7. The sheet feeding apparatus according to claim 6, further comprising a drive unit, wherein the first conveyance roller is a drive roller driven by the drive unit, andwherein the second conveyance roller is a driven roller that is driven and rotated by the drive roller.

8. The sheet feeding apparatus according to claim 1, further comprising a sealing member that is interposed at contact area where the first guide member and the walls on both sides are in contact with the first cover.

9. A sheet feeding apparatus comprising: an accommodating unit including a case forming an enclosed accommodating space configured to accommodate a sheet, a sheet discharge port formed in a part of the case and through which the sheet is discharged outside from the case, and a sheet feed portion configured to feed the sheet accommodated in the case to an outside of the case through the sheet discharge port; anda conveyance unit connected to the sheet discharge port of the accommodating unit and configured to convey the sheet discharged from the sheet discharge port,wherein the conveyance unit includes a first guide member, a second guide member, walls on both sides, a detection portion, and a cover,wherein the first guide member includes an opening,wherein the second guide member is arranged to face the first guide member,wherein the walls on both sides are arranged on both sides of the first guide member and the second guide member in a width direction perpendicular to a sheet conveyance direction,wherein, together with the first guide member and the second guide member, the walls on both sides forms a space of a conveyance path through which the sheet is conveyed,wherein the detection portion is configured to detect the sheet conveyed in the conveyance path via the opening, andwherein the cover encloses the space of the conveyance path in such a manner that the cover covers the opening and the detection portion.

10. An image forming system comprising: the sheet feeding apparatus according to claim 1; andan image forming apparatus forming an image on the sheet fed from the sheet feeding apparatus.