Sheet feeding device and image forming device

Abstract

To accurately execute a feeding operation even for a small size document.SOLUTION: A sheet feeding device includes a feeding unit having: an arm; a feeding roller 17 rotatably supported by the arm; a feeding clutch 25 that switches connection and disconnection of a driving force transmitted from a drive source to the feeding roller 17; and a stopper pressing part 19 that presses a stopper 10 against a biasing force. The feeding unit 21 is made movable up and down by driving the drive source to elevate and lower the arm so that the feeding roller 17 contacts and separates from the uppermost document supported by a document tray, when the arm is lowered to bring the feeding roller 17 into contact with the uppermost document supported by the document tray, the stopper pressing part 19 presses the stopper 10 so that the stopper 10 is positioned in an allowable position. The stopper pressing part 19 is arranged between the feeding roller 17 and the feeding clutch 25 in a width direction orthogonal to a feeding direction.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a sheet feeding device for feeding sheets and an image forming apparatus using the same.

Background Art

[0002] Conventionally, an image reading device capable of reading image information of a document (sheet) being fed while automatically feeding the documents (sheets) stacked on a document tray or the like one by one has been used. As a sheet feeding device used in the image reading device, an ADF (Auto Document Feeder) that automatically feeds documents has become widespread. In this type of sheet feeding device, the leading edge of the document is abutted against a stopper and placed on the document tray, and in this state, the document is detected by a detection sensor. Then, the document is fed by the rotation of the feeding roller, and when a plurality of sheets are fed, they are separated one by one by a separation roller (see Patent Document 1). In this sheet feeding device, the configuration of the stopper is advantageous in terms of cost and downsizing of the device because the number of component parts is small. Further, as the configuration of the feeding unit of the sheet feeding device, in addition to the above-described feeding roller, detection sensor, separation roller, and stopper, a stopper pressing unit that releases the stopper during feeding and a clutch that controls the driving of the feeding roller and the separation roller are provided. These are arranged in the order of the clutch, the feeding roller and the separation roller, the stopper and the stopper pressing unit, and the detection sensor in the main scanning direction (width direction) of the document (see FIG. 7).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, in image reading devices, it has been required to feed original documents of various sizes. Among them, a sheet feeding device of an image reading device capable of feeding an original document such as a business card size original document is required. In order to feed a small-size original document, it is necessary to shorten the distances among a detection sensor, a feeding roller, a stopper, and a stopper pressing portion in the main scanning direction (width direction) of the original document.

[0005] However, in the sheet feeding device described in Patent Document 1, they are arranged in the order of a clutch, a feeding roller and a separating roller, a stopper and a stopper pressing portion, and a detection sensor. Further, the feeding roller and the separating roller need to be arranged at the feeding center. For this reason, it is difficult to arrange the detection sensor, the feeding roller, and the stopper within the limited range of the main scanning direction of the small-size original document. As a result, for example, for an original document having a short length in the main scanning direction such as a business card size, the detection sensor, the stopper, the feeding roller, and the separating roller are not arranged at appropriate positions, and there is a possibility of inhibiting the original functions. Therefore, there has been a concern that the detection, feeding, and separation of the original document cannot be accurately performed for a small-size original document.

[0006] An object of the present invention is to provide a sheet feeding device and an image forming device capable of accurately performing a feeding operation even for a small-size original document.

Means for Solving the Problems

[0007] The sheet feeding device of the present invention includes a support portion that supports a sheet, a drive source, a regulation position where the sheet supported by the support portion abuts to regulate the feeding of the sheet, a stopper that is movable to a permission position that permits the feeding of the sheet supported by the support portion, a biasing means that biases the stopper so as to be located at the regulation position, an arm that can move up and down, a feeding rotating body that is rotatably supported by the arm and feeds the uppermost sheet supported by the support portion, a clutch that switches the connection and disconnection of the driving force transmitted from the drive source to the feeding rotating body, and a stopper pressing portion that presses the stopper against the biasing force of the biasing means. The feeding unit is configured such that the driving of the drive source raises and lowers the arm, thereby enabling the feeding rotating body to move up and down so as to contact and separate from the uppermost sheet supported by the support portion. When the arm is lowered and the feeding rotating body is brought into contact with the uppermost sheet supported by the support portion, the stopper pressing portion presses the stopper to position the stopper at the permission position. The stopper pressing portion is disposed between the feeding rotating body and the clutch in the width direction orthogonal to the sheet feeding direction.

[0008] Further, the image forming apparatus of the present invention includes the above-described sheet feeding device, an image reading unit that reads an image of the sheet fed by the sheet feeding device, and an image forming unit that forms an image on a recording material based on the image read by the image reading unit.

Effects of the Invention

[0009] According to the present invention, the feeding operation can be accurately executed even for small-sized originals.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 6. In this embodiment, a case where a document reading device 1 equipped with a sheet feeding device is mounted on an image forming device 100 will be described. This image forming device 100 includes an image forming unit 101 that forms an image on a recording material based on the image read by the document reading device 1.

[0012] [Document Reading Device] FIG. 1 is a perspective view of the document reading device 1 according to this embodiment, FIG. 2 is a cross-sectional view of the document reading device 1, and FIG. 3 is a plan view of the document reading device 1. In this embodiment, the main scanning direction (width direction) orthogonal to the document feeding direction of the document reading device 1 is the front-rear direction. A document reading device 1, which is an example of an image reading unit, has a document feeding device 20, which is an example of a sheet feeding device, and a document table scanner 50. The document table scanner 50 is a document table scanning type document reading device capable of reading a document placed on a document table glass, and has a housing 51 and a first reading unit 52. The first reading unit 52 irradiates light from an LED array as a light source onto the image information surface of the document D1, and forms an image of the reflected light reflected by the image information surface on a sensor element with a self-focus (registered trademark) lens to read image information. That is, the document reading device 1 reads the image of the document fed by the document feeding device 20.

[0013] [Document Feeding Device] The original document feeding device 20 is an ADF and has an original document tray 4 for placing an original document which is an example of a sheet, a feeding unit 21, etc. The original document tray 4 is an example of a supporting portion for supporting the original document. As shown in FIG. 2, the original document feeding device 20 has a substantially U-shaped U-turn path 7 (original document feeding path). The U-turn path 7 is formed by an upper guide surface 7a that contacts the upper surface of the original document to guide the original document and a lower guide surface 7b that contacts the lower surface of the original document to guide the original document. The U-turn path 7 is provided with a separation roller 8 and a separation pad 9 which are examples of separation rotating bodies, and a stopper 10 for restricting the leading edge position of the original document D1. Further, the U-turn path 7 is provided with a feeding roller 17 that contacts the uppermost one of the stacked original documents D1 to pick it up, and an original document presence / absence sensor 11 for detecting the presence or absence of the original document D1. Further, the U-turn path 7 is provided with conveying rollers 13, 14 for conveying the original document D1, a discharge roller 15, an edge sensor 16 for detecting the leading end portion and the trailing end portion of the original document D1, etc.

[0014] The stopper 10 is movably provided between a restricting position where the original document supported by the original document tray 4 abuts to restrict the feeding of the original document and a permitting position where the feeding of the original document supported by the original document tray 4 is permitted. When the stopper 10 is in the restricting position, it protrudes upward from below the U-turn path 7 through a hole provided in the lower guide surface 7b. On the other hand, when the stopper 10 is in the permitting position, it is located below the lower guide surface 7b and thus is in a retracted state from the U-turn path 7. Further, a biasing spring 12 which is an example of biasing means for biasing the stopper 10 to be in the restricting position is provided. In the present embodiment, the stopper 10 is arranged such that the restricting position is above and the permitting position is below, and it moves to the permitting position by being pushed downward from the restricting position by a stopper pressing portion 19 described later. However, the vertical relationship between the restricting position and the permitting position of the stopper 10 is not limited to this and may be the opposite.

[0015] An example of the detection unit, the document presence sensor 11, has a detection section for detecting a document. This detection section is disposed on the opposite side of the stopper 10 sandwiching the feed roller 17 in the main scanning direction. Further, the detection position of the detection section is disposed upstream of the stopper 10 in the feed direction, and detects the presence or absence of a document supported on the document tray 4.

[0016] The document feeding device 20 has a feeding unit 21. As shown in FIG. 4, the feeding unit 21 has a liftable arm 21a, a feed roller 17, a separation roller 8, a feed clutch 25, and a separation clutch 26. The feed roller 17 is an example of a feed rotating body, is rotatably supported by the arm 21a, and feeds the uppermost document supported on the document tray 4. Further, the feeding unit 21 has a stopper pressing portion 19 that presses the stopper 10 against the biasing force of the biasing spring 12.

[0017] The document feeding device 20 is provided with a second reading unit 18. Similar to the first reading unit 52, the second reading unit 18 irradiates light from an LED array as a light source onto the image information surface of the document D1, and forms an image of the reflected light reflected by the image information surface on the sensor element with a Selfoc (registered trademark) lens to read the image information. In the document feeding device 20 of the present embodiment, when the user places the document D1 on the document tray 4 and the sub-tray 5, the leading edge position of the document D1 is regulated by the stopper 10, and the document presence sensor 11 detects that the document D1 is present.

[0018] When the user instructs the reading start from the operation unit, a drive motor (not shown), which is an example of a drive source, rotates. As a result, the feeding unit 21 descends, and the stopper pressing portion 19 descends. Thereby, the stopper 10 is pushed down, and the document D1 is fed by the feeding roller 17. That is, the feeding unit 21 can move up and down the feeding roller 17 so as to be in contact with and separated from the uppermost document placed on the document tray 4 by moving the arm 21a up and down by driving the drive motor. When the feeding unit 21 lowers the arm 21a and brings the feeding roller 17 into contact with the uppermost document, the stopper pressing portion 19 presses the stopper 10 to position the stopper 10 at the allowable position.

[0019] Due to the rotation of the feeding roller 17, the document D1 is fed to the separation portion of the separation roller 8 and the separation pad 9, the document D1 is separated one by one, and the uppermost document D1 is separated and fed. Further, the separated document D1 is fed along the U-turn path 7 by the conveying roller 13 and conveyed to the reading portions of the first reading unit 52 and the second reading unit 18.

[0020] When the leading end portion of the document D1 is detected by the edge sensor 16, reading of the image information on the front surface of the document D1 is started by the first reading unit 52 at a position conveyed a predetermined amount from that position, and reading of the image information on the back surface of the document D1 is started by the second reading unit 18. After the start of reading, the document travels toward the conveying roller 14. Then, when the trailing end portion of the document D1 is detected by the edge sensor 16, reading of the image information by the first reading unit 52 and the second reading unit 18 is terminated at a position conveyed a predetermined amount from that position. Then, the document D1 is discharged to the discharge tray 24 by the discharge roller 15. In this way, in the document feeding device 20, the above-described reading operation is repeated until the document presence / absence sensor 11 detects the absence of a document.

[0021] [Document Tray] The document tray 4 will be described with reference to FIGS. 2 and 3. FIG. 3 is a plan view of the document feeding device 20. The document feeding device 20 has a document tray 4 for stacking documents. The document tray 4 has a pair of document regulating plates 30 and 31 that can contact both sides of the document in order to regulate the position of the set document in the main scanning direction to the feeding center. The document regulating plates 30 and 31 are connected by a gear train (not shown). When one of the document regulating plates is operated, the other document regulating plate also operates in conjunction. For example, when the document regulating plate 30 is operated in the B direction in FIG. 3, the document regulating plate 31 moves in the C direction. The amount of movement of the document regulating plates 30 and 31 is always the same, and it is possible to regulate the document to the feeding center regardless of the width of the document.

[0022] Confirmation windows 41 and 42 are provided at the central portion of the document tray 4 so that mainly small-sized documents stacked on the discharge tray 24 can be confirmed. By making it easier to confirm the upstream side of the discharge tray 24 through the confirmation windows 41 and 42, it is possible to prevent forgetting to pick up small-sized documents such as business card size or A6R size from the discharge tray 24.

[0023] A sub-tray 5 is provided on the upstream side of the document tray 4. The sub-tray 5 has a rotating portion 5b and is rotatable with respect to the document tray 4. By providing the sub-tray 5, it is possible to support documents with a long feeding direction. In addition, since the sub-tray 5 is rotatable, the sub-tray 5 can be closed so as to overlap the document tray 4. This improves the visibility and extractability of the documents discharged to the discharge tray 24, and by covering the document feeding port, it is possible to suppress the deposition and intrusion of foreign matters such as dust on the document tray 4 and in the U-turn path 7 when not in use.

[0024] [Feeding Unit] Hereinafter, the configuration including the stopper pressing portion 19 in the feeding unit 21, which is a feature of the present invention, will be described in detail with reference to FIGS. 4 to 6. FIG. 5 is a view of the feeding unit 21 as seen from the direction of arrow A in FIG. 3.

[0025] The feeding unit 21 includes a feeding clutch 25 which is an example of a clutch that switches the connection and disconnection of the driving force transmitted from the drive source to the feeding roller 17, and a feeding shaft 27 that connects the feeding roller 17 and the feeding clutch 25. Further, the feeding unit 21 includes a separating clutch 26 that switches the connection and disconnection of the driving force transmitted from the drive source to the separating roller 8, and a separating shaft 28 that connects the separating roller 8 and the separating clutch 26. In the present embodiment, the feeding clutch 25 is arranged coaxially with the feeding roller 17, and the separating clutch 26 is arranged coaxially with the separating roller 8.

[0026] In the feeding unit 21, the stopper pressing portion 19 is arranged between the feeding roller 17 and the feeding clutch 25 in the main scanning direction. That is, as the configuration of the feeding unit 21 of the present embodiment, the feeding roller 17 is provided at the central portion in the main scanning direction. Then, the original presence / absence sensor 11 is arranged on the right side in the feeding direction of the feeding roller 17, and the feeding clutch 25 and the separating clutch 26 are provided on the left side in the feeding direction of the feeding roller 17 on the opposite side of the original presence / absence sensor 11. Further, a stopper pressing portion 19 is provided between the feeding roller 17 and the feeding clutch 25 and the separating clutch 26, and a stopper 10 is arranged below the stopper pressing portion 19.

[0027] The stopper pressing part 19 is attached so as to be supported across the feeding shaft 27 and the separating shaft 28. The stopper pressing part 19 has a first fitting part 19a detachably attached to the feeding shaft 27, a second fitting part 19b detachably attached to the separating shaft 28, and a connecting part 19c bridging and connecting the first fitting part 19a and the second fitting part 19b. The connecting part 19c has a flat part 19d facing the stopper 10, and the flat part 19d presses the stopper 10 downward when the arm 21a is lowered. Note that the first fitting part 19a and the second fitting part 19b are not limited to being directly detachable from the feeding shaft 27 and the separating shaft 28, and may be indirectly detachable via shaft covers provided on the feeding shaft 27 and the separating shaft 28. Thus, since the stopper pressing part 19 is detachable from the feeding unit 21, the mounting work can be facilitated, and it can be easily removed and remounted during maintenance or the like.

[0028] Next, the effects of the present embodiment will be described. FIG. 7 shows a schematic view of the feeding unit 121 of the comparative example as viewed from the front. As shown in FIG. 7, in the main scanning direction, a feeding roller 117 is provided at the center, a stopper 10 is provided on the right side in the feeding direction, and a document presence / absence sensor 11 is provided on the right side of the stopper 10 and away from the feeding roller 117. Further, a stopper pressing part 119 is provided outside the arm 121a of the feeding unit 121. The feeding clutch 125 is provided adjacent to the feeding roller 117. However, in this case, since the document presence / absence sensor 11 is disposed outside the main scanning width of the document D2, which is a small-size document, there is a possibility that the document D2 cannot be detected by the document presence / absence sensor 11.

[0029] In contrast, in this embodiment, as shown in FIG. 5, the document presence / absence sensor 11 is arranged on the right side in the feeding direction of the feeding roller 17, and the stopper pressing portion 19 is provided on the left side in the feeding direction of the feeding roller 17 on the opposite side of the document presence / absence sensor 11. Further, in this embodiment, with respect to the main scanning direction, the distance from the feeding center to the document presence / absence sensor 11 is set to be equal to or less than the distance from the feeding center to the stopper 10. Furthermore, in this embodiment, an example of a small-size document is a business card, and with respect to the main scanning direction, the distance from the feeding center to the stopper 10 is set to be equal to or less than half of the business card size. The business card size in this embodiment is a document with a length of 55 [mm] in the main scanning direction and a length of 91 [mm] in the sub-scanning direction. That is, the distance from the conveyance center to the stopper 10 in the main scanning direction is set to be 22.5 [mm] or less. Thereby, within the main scanning direction of the document width of the small-size document, the feeding roller 17, the stopper 10, and the document presence / absence sensor 11 can be efficiently arranged, and it becomes possible to surely detect and separate the feeding of the small-size document.

[0030] As described above, according to the document feeding device 20 of this embodiment, with respect to the main scanning direction, the document presence / absence sensor 11 and the stopper pressing portion 19 are provided with the feeding roller 17 interposed therebetween. Thereby, the feeding operation can be accurately executed even for small-size documents. That is, according to this embodiment, it becomes possible to arrange the document presence / absence sensor 11, the feeding roller 17, the stopper 10, and the stopper pressing portion 19 within the range of the main scanning direction of the small-size document. For this reason, since the configurations necessary for detecting, feeding, and separating the document can be efficiently arranged in the main scanning direction of the small-size document, it becomes a configuration capable of surely detecting, feeding, and separating the small-size document.

[0031] Also, according to the document feeding device 20 of this embodiment, the feeding clutch 25 is arranged coaxially with the feeding roller 17, and at least a part of the stopper pressing portion 19 is arranged coaxially with the feeding roller 17. For this reason, the feeding operation can be accurately executed even for small-size documents with a simple configuration.

[0032] The manuscript feeding device 20 of the above-described embodiment has been described with the manuscript presence / absence sensor 11 provided on the right side in the feeding direction of the feeding roller 17 and the stopper pressing portion 19 provided on the left side in the feeding direction of the feeding roller 17. However, the present invention is not limited to this. For example, the left and right may be reversed, and the manuscript presence / absence sensor 11 may be provided on the left side in the feeding direction of the feeding roller 17, and the stopper pressing portion 19 may be provided on the right side in the feeding direction of the feeding roller 17.

[0033] In the manuscript feeding device 20 of the present embodiment, the feeding clutch 25 has been described as being arranged coaxially with the feeding roller 17, and the separation clutch 26 has been described as being arranged coaxially with the separation roller 8. However, the present invention is not limited to this. For example, the feeding clutch 25 and the feeding roller 17 may be on different axes, and similarly, the separation clutch 26 and the separation roller 8 may be on different axes.

[0034] In the manuscript feeding device 20 of the present embodiment, the stopper pressing portion 19 has been described as being attached so as to be supported across the feeding shaft 27 and the separation shaft 28. However, the present invention is not limited to this. For example, the stopper pressing portion may be supported by only one shaft, or may be provided on the arm 21a.

[0035] In the manuscript feeding device 20 of the present embodiment, the feeding roller 17 is applied as an example of the feeding rotating body, and the separation roller 8 is applied as an example of the separation rotating body. However, the present invention is not limited to this. In either case, a rotating belt or the like may be applied instead of the roller.

[0036] In the manuscript feeding device 20 of the present embodiment, the case where the manuscript feeding device 20 is applied to the manuscript reading device 1 has been described. However, the present invention is not limited to this, and it can be applied to the entire sheet feeding device.

Description of Reference Numerals

[0037] 1…Original document reading device (image reading unit), 4…Original document tray (support unit), 8…Separation roller (separation rotating body), 10…Stopper, 11…Original document presence sensor (detection unit), 12…Biasing spring (biasing means), 17…Feeding roller (feeding rotating body), 19…Stopper pressing part, 19a…First fitting part, 19b…Second fitting part, 19c…Connecting part, 19d…Flat part, 20…Original document feeding device (sheet feeding device), 21…Feeding unit, 21a…Arm, 25…Feeding clutch (clutch), 26…Separation clutch, 27…Feeding shaft, 28…Separation shaft, 100…Image forming device, 101…Image forming part, D1, D2…Original document (sheet)

Claims

1. a support portion for supporting a sheet; a drive source; a stopper movable between a regulation position where the sheet supported by the support portion abuts to regulate feeding of the sheet and a permission position where feeding of the sheet supported by the support portion is permitted; biasing means for biasing the stopper to be located at the regulation position; a liftable arm, a feed rotator rotatably supported by the arm for feeding the uppermost sheet supported by the support portion, a clutch for switching connection and disconnection of a driving force transmitted from the drive source to the feed rotator, and a stopper pressing portion for pressing the stopper against the biasing force of the biasing means, and a feed unit having the same; the feed unit is liftable so that the feed rotator approaches and separates from the uppermost sheet supported by the support portion by lifting and lowering the arm by driving of the drive source, and when the arm is lowered to bring the feed rotator into contact with the uppermost sheet supported by the support portion, the stopper pressing portion presses the stopper to position the stopper at the permission position; the stopper pressing portion is disposed between the feed rotator and the clutch in a width direction orthogonal to a sheet feeding direction; A sheet feeding device characterized by the above.

2. the clutch is disposed coaxially with the feed rotator; at least a part of the stopper pressing portion is disposed coaxially with the feed rotator; The sheet feeding device according to claim 1, characterized by the above.

3. comprising a detection unit having a detection portion for detecting a sheet; the detection portion is disposed on the opposite side of the stopper across the feed rotator in the width direction; The sheet feeding device according to claim 1 or 2, characterized by the above.

4. the detection portion is disposed upstream of the stopper in the feeding direction at its detection position and detects the presence or absence of a sheet supported by the support portion; The sheet feeding device according to claim 3, characterized by the above.

5. in the width direction, a distance from a sheet feeding center to the detection unit is equal to or less than a distance from the sheet feeding center to the stopper; The sheet feeding device according to claim 3 or 4, characterized by the above.

6. the clutch is a feed clutch; The sheet feeding unit includes a separating rotating body that separates a plurality of sheets one by one when the sheets are fed by the feeding rotating body, a separating clutch that switches the connection and disconnection of the driving force transmitted from the driving source to the separating rotating body, a feeding shaft that connects the feeding rotating body and the feeding clutch, and a separating shaft that connects the separating rotating body and the separating clutch. The stopper pressing portion is attached so as to be supported across the feeding shaft and the separating shaft. The sheet feeding device according to any one of claims 1 to 5, characterized in that.

7. The stopper pressing portion includes a first fitting portion detachably attached to the feeding shaft, a second fitting portion detachably attached to the separating shaft, and a connecting portion that connects the first fitting portion and the second fitting portion and has a flat portion facing the stopper. The connecting portion presses the stopper when the arm is lowered. The sheet feeding device according to claim 6, characterized in that.

8. The stopper moves to the allowable position by being pushed downward from the regulated position by the stopper pressing portion. The sheet feeding device according to any one of claims 1 to 7, characterized in that.

9. The sheet supported by the support portion is of business card size. In the width direction, the distance from the feeding center of the sheet to the stopper is equal to or less than half of the business card size. The sheet feeding device according to any one of claims 1 to 8, characterized in that.

10. The sheet feeding device according to any one of claims 1 to 9, an image reading unit that reads an image of the sheet fed by the sheet feeding device, and an image forming unit that forms an image on a recording material based on the image read by the image reading unit. An image forming apparatus, characterized in that.

Images