Sheet storage device and image forming apparatus

Abstract

To provide a sheet storage device equipped with a warm air mechanism that can reliably handle sheet bundles.SOLUTION: A sheet storage device 13 includes a body part 31 in which sheet bundles sent out along a predetermined feeding direction are stored, a lifting plate 33 which is provided in the body part 31 in a liftable manner, and on which sheet bundles are to be placed and a warm air mechanism 37 that blows warm air from the outside in the width direction orthogonal to the feeding direction toward the side surface of the sheet bundles placed on the lifting plate 33 and handles the sheet bundles. The warm air mechanism 37 includes a rotating body 57 which is positioned at the warm air out-blowing opening, and has a rotating shaft and blades fixed to the rotating shaft, and the rotating body 57 is rotated by the warm air blown out and changes the quantity of warm air.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a sheet storage device in which sheets are stored, and an image forming apparatus. [Background technology]

[0002] In image forming devices such as multifunction devices and printers, sheets are fed from a sheet storage device such as a paper feed cassette to a transport path along a predetermined feeding direction. The outer periphery of the sheet stack stored in the paper feed cassette is exposed to the outside air and is therefore prone to moisture. When the sheet stack absorbs moisture, the sheets tend to stick together, which may prevent them from being fed stably to the transport path. Specialty papers such as coated paper are particularly prone to sticking together.

[0003] Therefore, some image forming apparatuses are equipped with a hot air mechanism that blows hot air onto the sheet stack, as described in Patent Document 1. The hot air mechanism blows hot air onto the sides of the sheet stack from the outside in the width direction of the sheets perpendicular to the feeding direction. This evaporates the moisture contained in the sheet stack, and separates the sheets. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-111502 A Summary of the Invention [Problem to be solved by the invention]

[0005] The hot air mechanism of the paper feed cassette described in the above-mentioned Patent Document 1 blows hot air at a constant strength against the sides of the sheet stack. When the sheets contain a large amount of moisture and tend to stick together, there is a risk that the sheets cannot be separated properly just by blowing hot air in this manner.

[0006] SUMMARY OF THE PRESENT DISCLOSURE In consideration of the above circumstances, an object of the present invention is to provide a sheet storage device and an image forming apparatus that are provided with a hot air mechanism that can reliably separate a stack of sheets. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, the sheet storage device of the present invention is a sheet storage device comprising: a main body portion in which a stack of sheets sent out along a predetermined feeding direction is stored; a lifting plate that is movable within the main body portion and on which the stack of sheets is placed; and a hot air mechanism that blows hot air from the outside in a width direction perpendicular to the feeding direction toward the side of the stack of sheets placed on the lifting plate to handle the stack of sheets, wherein the hot air mechanism comprises a rotating body that is arranged at a hot air outlet and has a rotating shaft and a plurality of blades fixed to the rotating shaft, and the rotating body rotates due to the blown out hot air to vary the volume of the hot air.

[0008] In the sheet storage device of the present invention, the plurality of blades may be rectangular and have different lengths along a radial direction of the rotation shaft.

[0009] In the sheet storage device of the present invention, the hot air mechanism may include a load applying member that applies a load to the rotation of the rotating body.

[0010] In the sheet storage device of the present invention, the load applying member may be a damper connected to the rotating shaft.

[0011] In the sheet storage device of the present invention, the load applying member may be a variable speed motor connected to the rotary shaft.

[0012] The sheet storage device of the present invention may further comprise a pair of side cursors that are supported on the main body portion so as to be slidable in the width direction and that position the sheet stack placed on the lifting plate in the width direction, and the hot air mechanism may be supported by one of the pair of side cursors.

[0013] The image forming apparatus of the present invention is characterized in that it comprises the sheet storage device, an apparatus main body to which the sheet storage device is removably attached, a paper feeding device that feeds sheets from the sheet storage device attached to the apparatus main body, and an image forming unit that forms an image on the sheet fed from the sheet storage device by the paper feeding device. Effect of the Invention

[0014] According to the present invention, the strength of the hot air blown against the side of the paper stack is varied, so that the effect of diffusing the air flow is greater than when the strength of the hot air is constant, and the effectiveness of sorting the paper stack can be improved. [Brief description of the drawings]

[0015] [Figure 1] 1 is a front view showing a schematic internal structure of an image forming apparatus according to an embodiment of the present invention; [Diagram 2] 1 is a front view showing a side cursor and a paper feeder of a large-capacity cassette according to an embodiment of the present invention; [Diagram 3] 1 is a plan view showing a large-capacity cassette according to an embodiment of the present invention; [Figure 4] FIG. 2 is a cross-sectional perspective view showing a hot air mechanism of the large-capacity cassette according to an embodiment of the present invention. [Figure 5A] FIG. 4 is a perspective view showing a rotating body of a hot air mechanism of the large-capacity cassette according to one embodiment of the present invention. [Figure 5B] 1 is a cross-sectional view showing a rotating body of a hot air mechanism of a large-capacity cassette according to an embodiment of the present invention; [Figure 6A] FIG. 11 is a cross-sectional view showing a first modified example of a rotating body of a hot air mechanism of a large-capacity cassette according to an embodiment of the present invention. [Figure 6B] FIG. 13 is a perspective view showing a second modified example of a rotating body of a hot air mechanism of a large-capacity cassette according to an embodiment of the present invention. [Figure 6C] FIG. 13 is a perspective view showing a second modified example of a rotating body of a hot air mechanism of a large-capacity cassette according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming apparatus and a sheet storage device according to an embodiment of the present invention will now be described with reference to the drawings.

[0017] First, the image forming apparatus will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a schematic diagram showing the internal configuration of the image forming apparatus, and Fig. 2 is a front view showing a side cursor of a large-capacity cassette and a paper feeder. In the following description, the front side of the paper in Fig. 1 is the front side (front side) of the image forming apparatus. Fr, Rr, L, and R in each figure respectively indicate the front, rear, left, and right sides of the image forming apparatus 1.

[0018] 1, the device body 3 of the image forming apparatus 1 is provided with a paper feed section 5, an inkjet type image forming section 7, and a discharge tray 9. Furthermore, the device body 3 is formed with a sheet transport path 11 that runs from the paper feed section 5 through the image forming section 7 toward the discharge tray 9.

[0019] The paper feed section 5 is provided at the bottom of the device body 3, and includes a plurality of paper feed cassettes 13 that store sheets, and a plurality of paper feed devices 15 that feed sheets S from the paper feed cassettes 13 to the transport path 11. The direction in which the paper feed devices 15 feed the sheets from the paper feed cassettes 13 to the transport path 11 is referred to as a feed direction X. In the following description, the upstream side and the downstream side refer to the upstream side and the downstream side in the feed direction X. In addition, the direction intersecting the feed direction X (front-rear direction) is referred to as the width direction Y of the sheet.

[0020] The sheet feed cassette 13 includes two small-capacity cassettes 13S capable of accommodating a small amount of sheets, and two large-capacity cassettes 13L capable of accommodating a large amount of sheets. The small-capacity cassettes 13S are arranged side by side in the vertical direction. The large-capacity cassettes 13L are formed side by side in the horizontal direction below the small-capacity cassettes 13S. The large-capacity cassettes 13L are an example of a sheet storage device of the present invention.

[0021] As shown in Fig. 2, the sheet feeding device 15 includes a pickup roller 17, a pair of sheet feeding rollers 19, and a pair of retard rollers 21. The pickup roller 17, the pair of sheet feeding rollers 19, and the pair of retard rollers 21 are arranged in this order along the feeding direction X. As shown in Fig. 1, the sheet feeding device 15 is arranged above the downstream end of the corresponding sheet feeding cassette 13. The pickup roller 17 is supported at a predetermined sheet feeding position, and rotates while abutting against the uppermost sheet of the sheets contained in the corresponding sheet feeding cassette 13, thereby feeding a sheet from the sheet feeding cassette 13. The fed sheet is fed to the conveying path 11 by the pair of sheet feeding rollers 19 and the pair of retard rollers 21.

[0022] 1, the image forming section 7 is provided on the upper part of the device body 3, and includes a head unit 25 and a transport unit 27 that can move up and down between a printing position and a retreat position. Detailed explanation of each unit will be omitted.

[0023] During image formation, the transport unit 27 rises from the retracted position to the printing position. A sheet fed by the paper feed device 15 from a predetermined paper feed cassette 13 in the paper feed section 5 is transported along the transport path 11 to the image forming section 7. In the image forming section 7, when the sheet passes under the head unit 25, ink is ejected from the head unit 25 to form an image on the sheet. The sheet with the image formed is transported along the transport path 11 and discharged to the discharge tray 9.

[0024] Next, the large-capacity cassette 13L will be described with reference to Figures 2 and 3. Figure 3 is a plan view showing the large-capacity cassette.

[0025] As shown in FIG. 3, the large-capacity cassette 13L comprises a main body 31 in which sheets are stored, a lift plate 33 provided on the main body 31 on which the sheets are placed, a pair of side cursors 35 (35F, 35R) provided on the main body 31 for positioning the sheets placed on the lift plate 33, and a hot air mechanism 37 provided on one of the side cursors 35R.

[0026] The main body 31 has a size that allows a large number of sheets (eg, 4000 sheets) of the maximum size (eg, A3 size) on which images can be formed by the image forming unit 7 to be placed on the main body 31.

[0027] The lift plate 33 is a plate-like member having a size that allows a maximum size sheet to be placed thereon, and has an upstream portion 33a on the upstream side, a downstream portion 33b on the downstream side, and a central portion 33c between the upstream portion 33a and the downstream portion 33b. The upstream portion 33a and the downstream portion 33b have a rectangular planar shape that is long in the width direction Y and short in the conveying direction X. The central portion 33c is formed in the center of the width direction Y along the conveying direction X. The central portion 33c has a width shorter than the upstream portion 33a and the downstream portion 33b, and is narrower than the width of a minimum size sheet (e.g., a postcard). With this configuration, the lift plate 33 has rectangular cutouts 41 formed on both sides of the central portion 33c in the front-rear direction.

[0028] At the four corners of the lift plate 33, pins 43 are provided along the width direction Y. A wire (not shown) is connected to each pin 43. Each wire is connected to a winding roller via a pulley or the like (not shown). By rotating the winding roller in one direction, each wire is wound around the winding roller, and the lift plate 33 rises while remaining in a horizontal position. The lift plate 33 rises to a paper feed position where the top sheet of the stacked sheets can be fed by the paper feeder 15 (see FIG. 1). As shown in FIG. 2 in detail, the lift plate 33 rises until the top sheet of the sheet stack S abuts against the pickup roller 17 of the paper feeder 15. On the other hand, by rotating the winding roller in the other direction, each wire is unwound from the winding roller, and the lift plate 33 descends while remaining in a horizontal position. The lift plate 33 descends until it reaches the bottom plate of the main body 31.

[0029] The pair of side cursors 35 includes a front cursor 35F and a rear cursor 35R, which are supported on the bottom plate of the main body 31 so as to be slidable in a synchronous manner in a direction approaching or separating from each other. The front and rear side cursors 35F, 35R slide in a direction approaching each other and abut against the side edges of the sheet placed on the lift plate 33, thereby positioning the sheet with respect to the center in the width direction Y. At this time, the front and rear side cursors 35F, 35R slide through the notches 41 of the lift plate 33.

[0030] 3, a rectangular opening 45 that is long in the vertical direction is formed in the upper corner on the downstream side of one (rear) side cursor 35R. When the sheet stack S is raised to the sheet feeding position by the lift plate 33, the opening 45 opens above the side surface and the top surface of the sheet stack S.

[0031] Next, the hot air mechanism 37 will be described with reference to Fig. 4. Fig. 4 is a cross-sectional perspective view showing the hot air mechanism.

[0032] The hot air mechanism 37 includes a housing 51 , a sirocco fan 53 supported by the housing 51 , a heater 55 , and a rotor 57 .

[0033] Housing 51 has an air intake 61 and an air outlet 63, and forms an air passage 65 curved at a substantially right angle between air intake 61 and air outlet 63. Air outlet 63 is formed in a rectangular shape that is long in the vertical direction.

[0034] Sirocco fan 53 is attached to housing 51 so that suction port 71 opens in the same direction as outlet port 63 of housing 51, and outlet port 73 communicates with intake port 61 of housing 51. When sirocco fan 53 is driven, outside air is taken in through suction port 71, passes through outlet port 73 of sirocco fan 53 and intake port 61 of housing 51, is sent into air passage 65, and is blown out from outlet port 63. Sirocco fan 53 is an example of a fan of the present invention.

[0035] Heater 55 is accommodated inside air intake 61 of housing 51. Heater 55 heats the air taken into air passage 65.

[0036] Rotating body 57 will be described with reference to Figures 5A and 5B. Figure 5A is a perspective view of the rotating body, and Figure 5B is a cross-sectional view of the rotating body.

[0037] Rotating body 57 has a rotating shaft 81 and four blades 83 fixed to the rotating shaft 81. The four blades 83 have the same rectangular shape that is long in the axial direction of the rotating shaft 81. Furthermore, the four blades 83 are arranged at the same central angle (90 degrees) on the rotating shaft 81, as shown in Fig. 5B.

[0038] As shown in FIG. 4, the rotating body 57 is positioned inside the outlet 63 of the housing 51 with the rotating shaft 81 oriented in the vertical direction, and the upper and lower ends of the rotating shaft 81 are rotatably supported on the upper and lower walls of the housing 51.

[0039] 2 again, the hot air mechanism 37 is supported by the rear side cursor 35R. In detail, the hot air mechanism 37 is supported by the outer surface of the rear side cursor 35R so that the air outlet 63 of the housing 51 communicates with the opening 45 of the rear side cursor 35R. As a result, the rotating body 57 of the hot air mechanism 37 is exposed from the opening 45 of the rear side cursor 35R.

[0040] The operation of the hot air mechanism 37 having the above configuration will be described with reference to Fig. 2. After the sheet stack S is placed on the lift plate 33, the lift plate 33 is raised until the top sheet of the placed sheet stack S reaches a sheet feeding position where it abuts against the pickup roller 17 of the sheet feeding mechanism 15.

[0041] Thereafter, when the paper feed operation by the paper feeder 15 is started, the hot air mechanism 37 is driven. That is, the sirocco fan 53 is rotated and the heater 55 is driven. Then, as described above, the outside air is taken in from the intake port 71 into the air passage 65 of the housing 51 by the sirocco fan 53, and the taken-in air is heated by the heater 55. The heated air (hot air) is blown out from the outlet port 63. When the blown out hot air hits the blades 83 of the rotor 57, the rotor 57 rotates and the strength of the hot air is weakened. In this way, the strength of the hot air changes periodically due to the rotation of the rotor 57, and strong hot air and weak hot air are blown out alternately.

[0042] Part of the hot air passes over the downstream end of the paper stack S, and part of it is blown onto the downstream side of the paper stack S. This causes the moisture in the paper stack S to evaporate and hot air is also blown into the spaces between the sheets. This separates the paper stack S, allowing the sheets to be properly fed by the paper feeder 15. Note that the pickup roller 17 of the paper feeder 15 is in contact with the top surface of the paper stack S, so the sheets do not float up excessively.

[0043] As described above, according to the present invention, the strength of the hot air blown against the side of the paper stack S is varied, which increases the effect of diffusing the air flow compared to when the strength of the hot air is constant, thereby improving the effectiveness of sorting the paper stack S. Therefore, sheets can be properly fed even in the case of special paper such as coated paper.

[0044] Furthermore, the rotor 57 is rotated by the hot air blown by the sirocco fan 53 to vary the strength of the hot air, so there is no need to provide a separate power source for varying the strength of the hot air.

[0045] The hot air mechanism 37 is supported by one of the side cursors 35. When the paper feed operation starts, the side cursor 35 slides to abut against the side of the paper stack S, so that hot air can be reliably blown against the side of the paper stack S.

[0046] Next, a first modified example of the rotor 57 of the warm air mechanism 37 will be described with reference to Fig. 6A. Fig. 6A is a perspective view of the rotor.

[0047] The rotor 57 of the first modified example has a rotating shaft 101 and four blades 103 fixed to the rotating shaft 101. The four blades 103 include two first blades 103A and two second blades 103B. The first blade 103A and the second blade 103B are rectangular and long in the axial direction of the rotating shaft 101, but the length of the first blade 103A along the radial direction of the rotating shaft 101 is greater than the length of the second blade 103B. The first blade 103A and the second blade 103B are alternately arranged at the same central angle (90 degrees) in the circumferential direction of the rotating shaft 101.

[0048] According to the first modification, the areas of the first blade 103A and the second blade 103B that the blown hot air hits are different, so the strength of the blown hot air can be changed in more stages. This further increases the effect of diffusing the air flow, and the effectiveness of sorting the stack of paper sheets S can be improved.

[0049] Next, a second modified example of the rotor 57 of the warm air mechanism 37 will be described with reference to Fig. 6B. Fig. 6B is a perspective view of the rotor.

[0050] The rotating body 57 of the second modified example has the same shape as the above embodiment. The upper end of the rotating shaft 81 of the rotating body 57 penetrates the upper wall of the housing 51. A gear 111 is fixed to the upper end of the rotating shaft 81 protruding from the upper wall. The gear 111 meshes with a rotary damper (gear damper) 113 supported by the housing 51. The rotary damper 113 is an example of a load applying member of the present invention.

[0051] According to the second modified example, a braking torque is generated in the rotary damper 113 according to the rotation speed of the rotor 57, and a load is applied to the rotation of the rotor 57, so that the cycle of strength is longer than in the above embodiment. Therefore, the difference between the strength of the hot air becomes clearer, and the effect of sorting the paper stack can be further improved.

[0052] Next, a third modified example of the rotor 57 of the warm air mechanism 37 will be described with reference to Fig. 6C. Fig. 6C is a cross-sectional view of the rotor.

[0053] The rotor 57 of the third modified example has the same shape as the above embodiment. The upper end of the rotary shaft 81 of the rotor 57 penetrates the upper wall of the housing 51. A gear 121 is fixed to the upper end of the rotary shaft 81 protruding from the upper wall.

[0054] A variable speed motor 123 (e.g., a stepping motor) is supported in the housing 51. An output gear (not shown) is fixed to the output shaft of the motor 123. The output gear meshes with a gear 121 fixed to the upper end of the rotation shaft 81 of the rotor 57 via an idle gear 125. The variable speed motor is an example of a load-applying member of the present invention.

[0055] According to the third modified example, the rotation speed of the rotor 57 can be changed by changing the rotation speed of the motor 123. More specifically, the speed is changed within a speed range slower than the maximum rotation speed of the rotor 57 caused by the blown hot air. Therefore, in the case of coated paper or the like, by controlling the motor 123 to reduce the rotation speed of the rotor 57, the difference in strength of the hot air becomes clearer, and the effectiveness of sorting the paper stack can be improved.

[0056] The shape, number, dimensions, and arrangement of the blades 83 of the rotor 57 of the warm air mechanism 37 are not limited to those in the above embodiment including the first to third modified examples. For example, the shape of the blades 83 is not limited to a rectangular shape, but may be a trapezoid, a triangular shape, a semicircular shape, or the like, and each of the multiple blades 83 may have a different shape or different dimensions. The number of blades 83 may be three or five or more, other than four. Furthermore, the multiple blades 83 may be arranged at different central angles with respect to the rotation shaft 81. In this way, it is sufficient that the rotor 57 has a shape that can be rotated by the air sent in by a fan such as the sirocco fan 53, that is, a shape in which the force rotating the rotor 57 in one direction and the force rotating the rotor 57 in the other direction are not balanced. For this reason, for example, it is preferable that the number of blades 83 is an odd number, or the shape (length, width) of the blades 83 is non-uniform.

[0057] Although the present invention has been described with reference to specific embodiments, the present invention is not limited to the above embodiments, and those skilled in the art may modify the above embodiments without departing from the scope and spirit of the present invention. [Explanation of symbols]

[0058] 1. Image forming device 3. Device body 7 Image forming section 13L large capacity cassette (sheet storage device) 15 Paper feeder 31 Main body 33 Lifting Plate 35 Side Cursor 37 Hot air mechanism 57 Rotating Body 81 Rotation axis 83 Feather 113 Gear damper (damper, load-applying component) 123 Variable speed motor (load applying component)

Claims

1. a main body portion that accommodates a stack of sheets to be fed along a predetermined feeding direction; a lift plate provided in the main body portion so as to be capable of lifting and lowering, on which a stack of sheets is placed; A hot air mechanism that blows hot air toward a side of the sheet stack placed on the lift plate from an outer side in a width direction perpendicular to the feeding direction to separate the sheet stack, The hot air mechanism comprises a rotating body arranged at the hot air outlet and having a rotating shaft and a plurality of blades fixed to the rotating shaft, and a load applying member that applies a load to the rotation of the rotating body, and the rotating body rotates due to the hot air being blown out, thereby varying the volume of the hot air.This sheet storage device is characterized in that:

2. 2. The sheet storage device according to claim 1, wherein the plurality of blades are rectangular and have different lengths along a radial direction of the rotation shaft.

3. 2. The sheet storage device according to claim 1, wherein the load applying member is a rotary damper connected to the rotary shaft.

4. 2. The sheet storage device according to claim 1, wherein the load applying member is a variable speed motor connected to the rotary shaft.

5. a pair of side cursors supported on the main body portion so as to be slidable in the width direction and configured to position the sheet stack placed on the lift plate in the width direction; 5. The sheet storage device according to claim 1, wherein the hot air mechanism is supported by one of the pair of side cursors.

6. A sheet storage device according to any one of claims 1 to 5, an apparatus main body to which the sheet storage device is detachably attached; a sheet feeding device that feeds sheets from the sheet storage device attached to the device body; an image forming unit that forms an image on the sheet fed from the sheet storage device by the paper feeding device.

Images