Sheet transport device, and image reading device and image forming device equipped therewith.

Abstract

To improve detection of a small-sized paper sheet by a sensor, according to a configuration of setting the small-sized paper sheet by using an auxiliary tray.SOLUTION: An image reader 20 comprises a document tray 4 on which documents are stacked, and an auxiliary tray 40 attachable to / detachable from the document tray 4. The document tray 4 comprises a first regulation plate 30 and a second regulation plate 31 for regulating end portions in a width direction of the documents. The auxiliary tray 40 comprises a third regulation plate 41 and a fourth regulation plate 42 for regulating movement in the width direction of the documents. A central position CL2 between the third regulation plate 41 and the fourth regulation plate 42 is located on a first regulation plate 30 side with respect to a central position CL1 between the first regulation plate 30 and the second regulation plate 31.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a sheet conveying device, an image reading device provided with the same, and an image forming device.

Background Art

[0002] Conventionally, there is known an image reading device that can automatically feed and convey the originals stacked on an original tray or the like one by one, and sequentially read the image information of the conveyed originals. An automatic document feeder (hereinafter referred to as ADF) of the image reading device has a pair of regulating plates that can move in interlock with each other in the width direction. The user moves the regulating plates so as to abut against both end portions in the width direction of the original, and sets the original so that the center of the original coincides with the center of the original tray. With such a configuration, skew of the original generated when the ADF feeds the original is suppressed.

[0003] Furthermore, in the ADF, as described in Patent Document 1, there is one having a detachable auxiliary tray for specific small-sized originals. By using such an auxiliary tray, it is possible to stably feed small-sized originals.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, because transport components such as pickup rollers are located in the center in the width direction, the detection position of sensors for detecting documents located in the document tray or transport path may be offset from the center in the width direction. In such cases, there was a problem in that small-sized paper could not be detected when small-sized paper was set in the center in the width direction using an auxiliary tray. [Means for solving the problem]

[0006] One aspect of the present invention is a sheet loading section having a first support surface for supporting a sheet; a feeding section for feeding the sheet loaded on the sheet loading section in a feeding direction; a first restricting section provided so as to be movable in a width direction perpendicular to the feeding direction and restricting the position of a first end of the sheet supported on the first support surface in the width direction; a second restricting section provided so as to be movable in conjunction with the movement of the first restricting section so as to move in the width direction opposite to the direction of movement of the first restricting section and restricting the position of a second end of the sheet loaded on the first support surface on the width direction opposite to the first end; and a section supporting the sheet The sheet loading unit comprises an auxiliary loading unit which is detachable from the sheet loading unit and has two support surfaces, a third restricting portion which abuts against the first end of the sheet supported by the second support surface and restricts the movement of the sheet in the width direction, and a fourth restricting portion which abuts against the second end of the sheet supported by the second support surface and restricts the movement of the sheet in the width direction, and when the auxiliary loading unit is attached to the sheet loading unit, the second position which is the center position between the third restricting portion and the fourth restricting portion in the width direction is located on the side of the first restricting portion with respect to the first position which is the center position between the first restricting portion and the second restricting portion in the width direction. Ori , The auxiliary loading section is positioned on the sheet loading section by being sandwiched from both sides in the width direction by the first restricting section and the second restricting section. This is a sheet conveying device characterized by the following features. [Effects of the Invention]

[0007] According to the present invention, in a configuration in which small-sized paper is set using an auxiliary tray, a sheet transport device can be provided that improves the detection of small-sized paper by a sensor. [Brief explanation of the drawing]

[0008] [Figure 1] (a) is a perspective view of the image forming apparatus according to this embodiment. (b) is a schematic cross-sectional view of the image forming apparatus according to this embodiment. [Figure 2] This is a perspective view of the image reading device according to this embodiment. [Figure 3] This is a substantially cross-sectional view of the image reading device according to this embodiment, as seen from the front. [Figure 4] This is a top view of the image reading device according to this embodiment. [Figure 5] (a) is a perspective view of the auxiliary tray from above. (b) is a perspective view of the auxiliary tray from below. [Figure 6] (a) is a diagram showing the state before the auxiliary tray is placed in the document tray. (b) is a diagram showing the state after the auxiliary tray has been placed in the document tray. [Figure 7] (a) is a top view of the document tray with the auxiliary tray not installed. (b) is a top view of the document tray with the auxiliary tray installed. [Figure 8] This is a perspective view of the image scanner with the document tray closed. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described in detail below with reference to the attached drawings. Note that the following embodiments are merely examples of the present invention and do not limit the technical scope of the present invention.

[0010] <Image forming apparatus> First, the image forming apparatus 100 according to this embodiment will be described with reference to Figure 1. Figure 1(a) is a perspective view of the image forming apparatus 100 according to this embodiment, and Figure 1(b) is a cross-sectional view of the image forming apparatus 100. As shown in Figure 1, the image forming apparatus 100 comprises an image forming apparatus body (hereinafter referred to as the apparatus body) 100A equipped with an image forming function, and an image reading device 20 that reads image information from a document. The image reading device 20 comprises a reading unit 21 that is integrally provided with the apparatus body 100A and constitutes the upper part of the apparatus body 100A, and an automatic document feeder (Auto Document Feeder, hereinafter referred to as ADF) 22 that can be opened and closed relative to the reading unit 21. The ADF 22 is a sheet transport device in this embodiment. An operation panel 111 for the user to operate the image forming apparatus 100 is provided on one side of the reading unit 21, which is the image reading unit.

[0011] As shown in Figure 1(b), the main body of the apparatus 100A comprises a feeding unit 103, a process unit 104 as an image forming unit, and a fixing unit 108. The feeding unit 103 feeds sheets P, which are recording materials, one by one using a feeding roller 103a, which are loaded onto a feeding tray 113. The process unit 104 performs an electrophotographic process to create a toner image based on image information transmitted from the image reading device 20 or an external computer. The process unit 104 charges a photosensitive drum 105, which is a photoreceptor, and exposes it with a laser scanner 106 based on the image information to form an electrostatic latent image on the surface of the photosensitive drum 105, and develops the electrostatic latent image into a toner image.

[0012] The toner image supported on the photosensitive drum 105 is transferred to the sheet P in the transfer unit 112, which is composed of the photosensitive drum 105 and the transfer roller 107, and fixed to the sheet P in the fixer unit 108. The fixer unit 108 includes a fixer film 108b for heating the sheet P and a pressure roller 108a for pressing the sheet P against the fixer film 108b, applying heat and pressure to the toner image transferred to the sheet P. This causes the toner to melt and then solidify, fixing the image to the sheet P. The sheet P, on which the image has been fixed in the fixer unit 108, is discharged from the main body 100A by the discharge roller 109 and loaded onto the discharge tray 110. When performing double-sided printing, the discharge roller 109 transports the sheet P a predetermined distance and then reverses direction, sending the sheet P to the double-sided transport unit 129. After that, the sheet P, with the image formed on the other side, reaches the discharge roller 109 again and is discharged into the discharge tray 110. The process unit 104 described above is just one example of an image forming means for forming an image on a sheet. For example, an intermediate transfer type electrophotographic unit or an inkjet type image forming unit may be mounted on the main body 100A of the apparatus.

[0013] <Image reading device> Next, the image reading device 20 will be described using Figures 2 and 3. Figure 2 is a perspective view of the image reading device 20, and Figure 3 is a cross-sectional view of the image reading device 20.

[0014] The reading unit 21 comprises a reading unit 17, a document glass 26, and a scanning glass 27. The reading unit 17 irradiates the document with light using an LED array as a light source, and reads the image information of the document by focusing the reflected light reflected from the document onto a sensor element using a lens. The reading unit 17 is provided to be movable in the sub-scanning direction (left and right direction in Figure 3) and reads the image of the document placed on the document glass 26 (fixed reading). The ADF 22 is supported by a hinge (not shown) located at the rear of the device so as to be rotatable relative to the reading unit 21. When a user places a document on the document glass 26, the user opens the ADF 22 to expose the document glass 26. Then, after the user places the document on the document glass 26, the user closes the ADF 22, and the document is fixed to the document glass 26 by the bottom surface of the ADF 22.

[0015] The ADF22 comprises a document tray 4, which serves as a sheet loading section for stacking documents, and a paper output tray 24, which serves as a paper output section for ejecting documents. The paper output tray 24 is located below the document tray 4 in the vertical direction. The ADF22 has, in order from the upstream side in the transport direction, a pickup roller 6, a separation roller 8, a transport roller pair 13, a transport roller pair 14, and a paper output roller pair 15, and transports documents along a roughly U-shaped document transport path (U-turn path) 7. Transport members such as the pickup roller 6 are held in the housing 22a of the ADF22. The ADF22 also has a document presence sensor 11, which serves as a detection section for detecting documents on the document tray 4, a document edge sensor 16, which detects documents in the document transport path 7, and a reading unit 18 that reads the image of the document. The reading unit 18 in this embodiment has the same configuration as the reading unit 17.

[0016] Next, we will explain the operation of the image reading device 20 in which it reads an image while transporting the document (smooth reading). First, the user places the document D1 on the document tray 4. At this time, the user sets the document so that the leading edge (the downstream end in the feeding direction) of the document abuts against the document stopper 10 located on the downstream side of the document tray 4. The document D1 set on the document tray 4 is detected by the document presence sensor 11.

[0017] When the user gives a reading start instruction using the operation panel 111, the fixing of the document stopper 10 is released, and the document D1 stacked on the document tray 4 is fed in the conveyance direction F by the pickup roller 6 which is a feeding unit. The document D1 fed by the pickup roller 6 is separated into single sheets by the separation roller 8 and the separation pad 9. The document D1 separated into single sheets is conveyed by the pair of conveyance rollers 13 along the document conveyance path 7 to the reading areas of the reading units 17 and 18.

[0018] After the leading edge of the document D1 is detected by the document edge sensor 16 and the document D1 has been conveyed a predetermined amount, the reading of the front surface of the document D1 by the reading unit 17 is started. At this time, the reading unit 17 reads the image on the front surface of the document D1 through the platen glass 27. Further, after the reading by the reading unit 17 is started and the document D1 is conveyed further, the reading of the back surface of the document D1 by the reading unit 18 is started. Then, the document D1 whose both-sided images have been read is conveyed by the pair of conveyance rollers 14 to the pair of discharge rollers 15 and discharged by the pair of discharge rollers 15. The document D1 discharged by the pair of discharge rollers 15 is stacked on the discharge tray 24. The image reading device 20 repeats such a continuous reading operation until the document presence / absence sensor 11 stops detecting the document D1. Thereby, the image reading device 20 can read the images of all the documents D1 stacked on the document tray 4. Note that the image reading device 20 can also execute only the reading of the front surface by the reading unit 17 for the conveyed document D1.

[0019] <Document Tray> Next, the configuration of the document tray 4 will be described using FIGS. 2, FIG. 4, and FIG. 8. FIG. 4 is a view of the ADF 22 seen from above. FIG. 8 is a perspective view of the image reading device 20 with the document tray 4 closed.

[0020] The document tray 4 has an opening 4a in the center of the width direction perpendicular to the transport direction F. The opening 4a is positioned so that the user can see a portion of the output tray 24 below the document tray 4 through the opening 4a. In other words, a portion of the output tray 24 is exposed upward through the opening 4a. This allows the user to see the documents discharged into the output tray 24 through the opening 4a. Furthermore, the document tray 4 has a sub-tray 5 as a rotatable support part that is rotatably mounted relative to the first support surface 4b that supports the documents. The sub-tray 5 can move between a closed position (Figure 8) that overlaps with the first support surface 4b and an open position (Figure 2) that opens the first support surface 4b by rotating in directions A and B as shown in Figure 3. When the sub-tray 5 is in the closed position, the surface of the sub-tray 5 that supports the documents and the first support surface 4b are positioned opposite each other. Furthermore, when the sub-tray 5 is in the open position, the surface of the sub-tray 5 that supports the document and the first support surface 4b are located on approximately the same plane, and in this state, the user can place a document in the document tray 4. In this way, the sub-tray 5 is in the open position when the user is using the image reader 20, and in the closed position when the user is not using the image reader 20, thereby preventing foreign objects from entering the document transport path 7 when not in use.

[0021] The document tray 4 is provided with a first restricting plate 30 (first restricting part) that restricts the position of one end (first end) of a document supported on the first support surface 4b in the width direction, and a second restricting plate 31 (second restricting part) that restricts the position of the other end (second end) of the document on the opposite side. The first restricting plate 30 and the second restricting plate 31 are movable in the width direction on the first support surface 4b. The first restricting plate 30 and the second restricting plate 31 are connected by a gear (not shown) and are configured to move in conjunction with each other in the opposite direction to the direction of movement of the other. For example, if the first restricting plate 30 moves in direction C, the second restricting plate 31 moves the same distance in direction D in conjunction with the movement of the first restricting plate 30. In this way, because the first restricting plate 30 and the second restricting plate 31 move in conjunction with each other, the central position CL1 (see Figure 7 described later) of the first restricting plate 30 and the second restricting plate 31 in the width direction always coincides with the central position of the first support surface 4b. When the user places a document in the document tray 4, they move the first regulating plate 30 and the second regulating plate 31 so that each of them contacts the edge of the document in the width direction. This suppresses the skewing of the document that occurs when the document is fed.

[0022] <Auxiliary tray> Next, the auxiliary tray 40, which serves as an auxiliary loading section, will be explained using Figures 5 to 7. Figure 5(a) is a perspective view of the auxiliary tray 40 viewed from above, and Figure 5(b) is a perspective view of the auxiliary tray 40 viewed from below. The image reading device 20 of this embodiment has an auxiliary tray 40 that is detachable from the document tray 4. The auxiliary tray 40 is attached to the document tray 4 by the user when setting small-sized documents in the ADF 22. Here, a small-sized document is a document whose width is smaller than the distance between the first regulating plate 30 and the second regulating plate 31 at the position where the first regulating plate 30 and the second regulating plate 31 are closest to each other. In other words, without the auxiliary tray 40, the first regulating plate 30 and the second regulating plate 31 cannot regulate the edges of a small-sized document. Therefore, in this embodiment, by attaching the auxiliary tray 40 to the document tray 4, both ends of the small-sized document in the width direction are regulated by the auxiliary tray 40. Small-sized documents placed in the auxiliary tray 40 attached to the document tray 4 are fed by the pickup roller 6 and scanned, just like other documents.

[0023] As shown in Figure 5, the auxiliary tray 40 has a notch 40a cut out in the transport direction F and a second support surface 40b for supporting small-sized documents. On both sides of the second support surface 40b in the width direction, there is a third restricting plate 41 (third restricting section) that abuts against one end of the first restricting plate 30 of the small-sized document, and a fourth restricting plate 42 (fourth restricting section) that abuts against the other end of the second restricting plate 31 of the small-sized document. The third restricting plate 41 and the fourth restricting plate 42 are wall surfaces that extend perpendicularly from the second support surface 40b and restrict the movement of small-sized documents in the width direction. When the auxiliary tray 40 is attached to the document tray 4, the third restricting plate 41 and the fourth restricting plate 42 are located between the first restricting plate 30 and the second restricting plate 31 in the width direction. The auxiliary tray 40 also has recesses 43 and 44 for the user to grasp when attaching the auxiliary tray 40 to the document tray 4. The user can grasp the auxiliary tray 40 by pinching the recesses 43 and 44 with their fingers from both sides.

[0024] Furthermore, the third regulating plate 41 and the fourth regulating plate 42 of the auxiliary tray 40 are each provided with upper surface regulating sections 45 and 46 that regulate the upper surface of the document supported on the second support surface 40b. By placing the document below the upper surface regulating sections 45 and 46, the document is prevented from floating up during feeding. In addition, since the upper surface regulating sections 45 and 46 are positioned at the maximum height of the document that can be loaded into the auxiliary tray 40, it is possible to prevent the user from accidentally loading more documents than the maximum number of documents allowed for use into the auxiliary tray 40.

[0025] As shown in Figure 5(b), the notch 40a of the auxiliary tray 40 has an engaging portion 47 that protrudes downward from the lower surface of the auxiliary tray 40. The engaging portion 47 engages with the opening 4a when the auxiliary tray 40 is attached to the document tray 4.

[0026] Next, the method for attaching the auxiliary tray 40 will be described with reference to Figure 6. Figure 6 is a diagram showing the method for attaching the auxiliary tray 40, where Figure 6(a) shows the direction in which the auxiliary tray 40 is attached, and Figure 6(b) shows the direction in which the auxiliary tray 40 is fixed. First, the user places the auxiliary tray 40 on the first support surface 4b so that the notch 40a of the auxiliary tray 40 aligns with the opening 4a of the document tray 4. At this time, the engaging portion 47 is inserted into the opening 4a. Next, with the auxiliary tray 40 on the first support surface 4b, the user sandwiches the auxiliary tray 40 from both sides in the width direction using the first regulating plate 30 and the second regulating plate 31. At this time, the sides 48 and 49 of the auxiliary tray 40 contact the first regulating plate 30 and the second regulating plate 31, respectively. In this way, the auxiliary tray 40 is positioned by the engaging portion 47 engaging with the opening 4a and the sides 48 and 49 contacting the first regulating plate 30 and the second regulating plate 31.

[0027] Next, the document transport center will be explained using Figure 7. Figure 7 is a diagram for comparing the central position of the first regulating plate 30 and the second regulating plate 31 with the central position of the auxiliary tray 40. Figure 7(a) shows the first support surface 4b with the auxiliary tray 40 removed, and Figure 7(b) shows the first support surface 4b with the auxiliary tray 40 attached.

[0028] In the auxiliary tray 40, the distance W1 between the third regulating plate 41 and the side surface 48 is smaller than the distance W2 between the fourth regulating plate 42 and the side surface 49. Therefore, the central position CL1 (first position) between the first regulating plate 30 and the second regulating plate 31 in the width direction does not coincide with the central position CL2 (second position) between the third regulating plate 41 and the fourth regulating plate 42. Specifically, because W1 is smaller than W2, the central position CL2 between the third regulating plate 41 and the fourth regulating plate 42 is located on the first regulating plate 30 side (first regulating section side) relative to the central position CL1 between the first regulating plate 30 and the second regulating plate 31. Therefore, in this embodiment, compared to an original document set without the auxiliary tray 40, a small-sized original document set in the auxiliary tray 40 will be shifted towards the first regulating plate 30. In this embodiment, the amount of shift between the central position CL1 and the central position CL2 is approximately 5 [mm].

[0029] As mentioned above, the document stopper 10 is positioned near the pickup roller 6, and therefore may not be able to be positioned in the center in the width direction. For this reason, in this embodiment, the document stoppers 10 are positioned on both sides of the pickup roller 6 with a gap between them. Also, the detection positions of the document presence sensor 11 and the document edge sensor 16 may not be able to be positioned in the center of the document transport path 7 in the width direction due to the interaction with other components. For this reason, in this embodiment, the detection positions of the document presence sensor 11 and the document edge sensor 16 are positioned closer to the first regulating plate 30 than the center in the width direction. In this way, if the components that contact the document or the components for detecting the document are not in the center of the document transport path 7, there is a risk that these components will not function if a small-sized document is set with the center as the reference point. For example, the document presence sensor 11, which is positioned off-center in the width direction, may not be able to detect a small-sized document set with the center as the reference point because the edges of the document may not reach the document presence sensor 11.

[0030] However, in this embodiment, since the central position CL2 of the third regulating plate 41 and the fourth regulating plate 42 of the auxiliary tray 40 is shifted towards the first regulating plate 30, the document presence sensor 11 can detect even small-sized documents. Similarly, the document edge sensor 16 can also detect small-sized documents.

[0031] Furthermore, in this embodiment, with the auxiliary tray 40 attached to the document tray 4, the sub-tray 5 can be moved from the open position to the closed position. This eliminates the need for users who primarily use small-sized documents to remove the auxiliary tray 40, improving user convenience.

[0032] In this embodiment, the detection positions of the document presence sensor 11 and the document edge sensor 16 are located on the side of the first regulating plate 30 rather than the center in the width direction. However, these detection positions may also be located on the side of the second regulating plate 31. In such cases, it is preferable that the central position CL2 of the third regulating plate 41 and the fourth regulating plate 42 is also on the side of the second regulating plate 31 (W1 > W2). [Explanation of Symbols]

[0033] 4. Document tray 20 Image reading device 21 Reading section 22 ADF 40 auxiliary trays 100 Image forming apparatus

Claims

1. A sheet loading section having a first support surface for supporting the sheet, A feeding unit that feeds the sheets loaded in the sheet loading unit in the feeding direction, A first restricting portion is provided so as to be movable in the width direction perpendicular to the feeding direction, and restricts the position of the first end of the sheet supported on the first support surface in the width direction, A second restricting portion is provided so as to be movable in conjunction with the movement of the first restricting portion that it moves in the width direction opposite to the movement direction of the first restricting portion, and restricts the position of the second end of the sheet loaded on the first support surface in the width direction opposite to the first end, The sheet loading unit has a second support surface for supporting the sheet, a third restricting portion that abuts against the first end of the sheet supported by the second support surface to restrict the sheet's movement in the width direction, and a fourth restricting portion that abuts against the second end of the sheet supported by the second support surface to restrict the sheet's movement in the width direction, and an auxiliary loading unit that is detachable from the sheet loading unit, Equipped with, In the state in which the auxiliary loading section is attached to the sheet loading section, the second position, which is the center position between the third and fourth restricting sections in the width direction, is located on the side of the first restricting section with respect to the first position, which is the center position between the first restricting section and the second restricting section in the width direction. The auxiliary loading section is positioned on the sheet loading section by being sandwiched from both sides in the width direction by the first restricting section and the second restricting section. A sheet conveying device characterized by the following features.

2. The sheet loading section has a detection unit that detects sheets loaded on it, The detection position at which the detection unit detects the sheet is located on the first restricting unit side with respect to the first position in the width direction. The sheet conveying device according to feature 1.

3. In the state in which the auxiliary loading section is attached to the sheet loading section, the third restricting section and the fourth restricting section are located between the first restricting section and the second restricting section in the width direction. The sheet conveying device according to feature 1 or 2.

4. A discharge section is provided below the sheet loading section in the vertical direction, and the sheets supplied by the supply section are discharged from there. An opening provided on the first support surface, the opening being such that a part of the discharge section is exposed upward through the opening, It has, The auxiliary loading section has an engaging portion that engages with the opening, A sheet conveying device according to any one of claims 1 to 3.

5. The sheet loading section is rotatably provided with respect to the first support surface and has a rotatable support section that can move between a closed position where it overlaps with the first support surface and an open position where it opens the first support surface. With the auxiliary loading section attached to the sheet loading section, the rotating support section is movable from the open position to the closed position. A sheet conveying device according to any one of claims 1 to 4.

6. The third and fourth regulating sections are provided with upper surface regulating sections that regulate the position of the upper surface of the document supported on the second support surface. A sheet conveying device according to any one of claims 1 to 5.

7. A sheet conveying device according to any one of claims 1 to 6, An image reading unit reads an image of a sheet fed by the aforementioned feeding unit, An image reading device characterized by comprising the following:

8. The image reading device according to claim 7, An image forming unit forms an image on a recording material based on the image of the sheet read by the image reading unit, An image forming apparatus characterized by comprising:

Images