Manuscript conveying device

Abstract

To increase the capacity of a paper feeding tray without increasing the vertical size of a wall on the downstream side in a paper feeding direction of the paper feeding tray.SOLUTION: A manuscript conveying device includes a top plate part 22 which is provided downstream in a paper feeding direction Z from a paper feeding tray and with which the underside of the manuscripts to be fed comes into contact, a fixed wall part 27 that is provided below the upstream end of the top plate part 22 in the paper feeding direction Z and is fixed in position, and a lifting wall part 29 that is provided above the downstream end of the paper feeding tray in the paper feeding direction Z, faces the fixed wall part 27 upstream of the fixed wall part 27 in the paper feeding direction Z and rises and falls together with the paper feeding tray along the fixed wall part 27. The lifting wall part 29 has slits 29S1 to 10 that extend vertically. The fixed wall part 27 has fins 27F1 to 10 that extend vertically. The upper ends of the slits 29S1 to 10 are open in a vertical direction. The fins 27F1 to 10 protrude upstream in the paper feeding direction Z and are positioned inside the slits 29S1 to 10.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present invention relates to a document transport device. [Background technology]

[0002] A document transport device that transports a document to a reading position of an image reading device is known. The document transport device includes, for example, a paper feed tray on which the document is loaded, a discharge tray provided below the paper feed tray, and a transport mechanism that transports the document from the paper feed tray to the reading position of the document reading device and then to the discharge tray.

[0003] The greater the capacity (the amount of documents that can be loaded) of the paper feed tray and discharge tray of a document transport device, the more convenient it becomes. Therefore, technologies for realizing a document transport device with a larger capacity have been studied. For example, Patent Documents 1 and 2 disclose a device in which the paper feed tray is configured as a lifting type that moves up and down in a roughly parallel manner, and the paper feed tray is raised as stacked sheets on the paper feed tray are transferred to the discharge tray, thereby expanding the stacking space for discharged sheets between the paper feed tray and the discharge tray. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-167545 [Patent Document 2] Patent Publication No. 2021-66547 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, a document transport device has a wall portion that contacts the downstream end of a document on a paper feed tray. In order to increase the capacity of the paper feed tray, it is necessary to increase the vertical size of the wall portion, but in that case, the vertical size of the document transport device also increases.

[0006] SUMMARY OF THE INVENTION In consideration of the above circumstances, an object of the present invention is to increase the capacity of a paper feed tray without increasing the vertical size of the wall of the paper feed tray on the downstream side in the paper feed direction. [Means for solving the problem]

[0007] In order to solve the above problem, the document transport device of the present invention comprises a paper feed tray on which documents are loaded, a paper feed mechanism that feeds the documents loaded in the paper feed tray in a predetermined paper feed direction, a paper feed tray lifting mechanism that raises and lowers the paper feed tray, a top plate portion that is located downstream of the paper feed tray in the paper feed direction and with which the underside of the fed document comes into contact, a fixed wall portion that is located below the upstream end of the top plate portion in the paper feed direction and is fixed in position, and a lifting wall portion that is located above the downstream end of the paper feed tray in the paper feed direction and faces the fixed wall portion upstream of the fixed wall portion in the paper feed direction and rises and falls together with the paper feed tray along the fixed wall portion, wherein the lifting wall portion has a slit that extends vertically, and the fixed wall portion has fins that extend vertically, the upper end of the slit is open vertically, and the fins protrude upstream in the paper feed direction and are positioned inside the slit.

[0008] The slits may be provided at multiple locations in the width direction of the document that intersects with the paper feed direction, and the fins may be provided at multiple locations corresponding to each of the slits, with at least two of the fins coming into contact with the document loaded in the paper feed tray.

[0009] The edge of the slit may protrude upstream in the paper feed direction, and the tip of the fin and the tips of the edges on both sides of the fin may form the same plane.

[0010] The upper end of the fin may be inclined so that the downstream side in the paper feed direction is higher. [Effects of the Invention]

[0011] According to the present invention, the capacity of the paper feed tray can be increased without increasing the vertical size of the wall on the downstream side of the paper feed tray in the paper feed direction. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a front view schematically showing the internal configuration of an image forming apparatus according to a first embodiment of the present invention. [Figure 2] 1 is a perspective view showing the appearance of a document transport device according to a first embodiment of the present invention. [Figure 3] FIG. 2 is a front view schematically showing a paper feed mechanism and a transport mechanism according to the first embodiment of the present invention. [Figure 4] FIG. 2 is a front view schematically showing a conveyance mechanism and a paper feed tray lifting mechanism according to the first embodiment of the present invention. [Figure 5] FIG. 2 is a rear view schematically showing the paper feed tray lifting mechanism according to the first embodiment of the present invention. [Figure 6] FIG. 2 is a front view schematically showing a conveyance mechanism and a paper feed tray lifting mechanism according to the first embodiment of the present invention. [Figure 7] FIG. 2 is a perspective view showing a fixed wall portion, a liftable wall portion, and a paper feed tray according to the first embodiment of the present invention. [Figure 8] FIG. 2 is a perspective view showing a fixed wall portion, a liftable wall portion, and a paper feed tray according to the first embodiment of the present invention. [Figure 9] FIG. 2 is a perspective view showing a fixed wall portion, a liftable wall portion, and a paper feed tray according to the first embodiment of the present invention. [Figure 10] FIG. 2 is an exploded view showing a fixed wall portion and a liftable wall portion according to the first embodiment of the present invention. [Figure 11] 2 is an exploded view showing a fixed wall portion and a liftable wall portion according to the first embodiment of the present invention. FIG. [Figure 12] FIG. 2 is a perspective view showing a cross section of a liftable wall portion and a front portion of a paper feed tray according to the first embodiment of the present invention. [Figure 13] FIG. 10 is an exploded view showing a fixed wall portion and a liftable wall portion according to a second embodiment of the present invention. [Figure 14] FIG. 10 is a perspective view showing a state in which a liftable wall portion according to a second embodiment of the present invention is located at a lower limit position. [Figure 15] FIG. 10 is a perspective view showing a state in which a liftable wall portion according to a second embodiment of the present invention is located at an upper limit position. [Figure 16] 3 is a diagram showing a fixed wall portion, a liftable wall portion, and a paper feed tray according to the first embodiment of the present invention, viewed obliquely from above on the right. FIG. [Figure 17] 10 is a diagram showing a fixed wall portion, a liftable wall portion, and a paper feed tray according to a second embodiment of the present invention, viewed from diagonally above right. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] [First embodiment] Hereinafter, a document transport device 120 and an image forming apparatus 100 according to a first embodiment of the present invention will be described with reference to the drawings.

[0014] First, the overall configuration of image forming apparatus 100 will be described. Fig. 1 is a front view that schematically shows the internal configuration of image forming apparatus 100. In the following description, the front side of the paper in Fig. 1 is the front side (front side) of image forming apparatus 100, and left and right directions will be described based on the direction when image forming apparatus 100 is viewed from the front. In each figure, U, Lo, L, R, Fr, and Rr represent up, down, left, right, front, and rear, respectively.

[0015] The image forming apparatus 100 includes a printing device 1, a document reading device 110, and a document transport device 120. The document reading device 110 is provided above the printing device 1, and the document transport device 120 is provided above the document reading device 110. The document transport device 120 transports a document G via a reading position A of the document reading device 110. The document reading device 110 is a flatbed image scanner that reads the document G and generates image data. The printing device 1 forms an image on a sheet S based on the image data. Note that, although this embodiment shows an example in which the printing device 1 forms an image using an electrophotographic method, the printing device 1 may also be configured to form an image using another method (for example, an inkjet method).

[0016] The printing device 1 includes a rectangular parallelepiped main body housing 3. At the bottom inside the main body housing 3 are a paper feed cassette 4 that stores sheets S, and a paper feed roller 5 that feeds sheets S from the paper feed cassette 4 to the right. Above the paper feed cassette 4 is an image creating device 6 that forms a toner image using an electrophotographic method, and above and to the right of the image creating device 6 is a fixing device 7 that fixes the toner image to the sheet S. Above the fixing device 7 are an ejection roller 8 that ejects the sheet S with the fixed toner image, and an ejection tray 9 on which the ejected sheet S is stacked.

[0017] Inside the main body housing 3, there is provided a conveyance path 10 that runs from the paper feed roller 5 through the image forming device 6 and the fixing device 7 to the discharge roller 8. The conveyance path 10 is mainly formed of plate-like members that face each other with a gap therebetween to allow the sheet S to pass through, and conveyance rollers 17 that sandwich and convey the sheet S are provided at multiple locations in the conveyance direction Y. A registration roller 18 is provided upstream of the image forming device 6 in the conveyance direction Y. To the right of the fixing device 7, there is provided a reversing conveyance path 10R that branches off from the conveyance path 10 downstream of the fixing device 7 in the conveyance direction Y and merges with the conveyance path 10 upstream of the registration roller 18 in the conveyance direction Y.

[0018] The control unit 2 includes a calculation unit and a storage unit (not shown). The calculation unit is, for example, a CPU (Central Processing Unit). The storage unit includes storage media such as a ROM (Read Only Memory), a RAM (Random Access Memory), and an EEPROM (Electrically Erasable Programmable Read Only Memory). The calculation unit performs various processes by reading and executing control programs stored in the storage unit. Note that the control unit 2 may be realized by an integrated circuit only, without using software.

[0019] A display operation unit (not shown) is provided on the front side of the document reading device 110. The display operation unit includes a display panel, a touch panel provided on top of the display surface of the display panel, and a keypad adjacent to the display panel (not shown). The control unit 2 displays screens showing operation menus and statuses of the printing device 1 and the document reading device 110 on the display panel, and controls each unit of the printing device 1 and the document reading device 110 in response to operations detected by the touch panel and the keypad.

[0020] The basic image formation operation of the printing device 1 is as follows: When a print job for single-sided printing is input to the printing device 1 from the display operation unit, an external computer, or the like, the paper feed rollers 5 feed the sheet S from the paper feed cassette 4 to the transport path 10, the registration rollers 18, which have stopped rotating, correct any skew in the sheet S, and the registration rollers 18 feed the sheet S to the imaging device 6 at a predetermined timing. The imaging device 6 forms a toner image on the sheet S using an electrophotographic method. Next, the fixing device 7 fuses the toner image onto the sheet S while clamping and transporting the sheet S, and the discharge rollers 8 discharge the sheet S onto the discharge tray 9. In the case of double-sided printing, the sheet S with the toner image fixed on its first side is sent into the transport path 10 via the reverse transport path 10R, where the toner image is transferred to the second side.

[0021] [Document reader] The document reading device 110 includes a first carriage 81 equipped with a light source and a reflecting mirror, a second carriage 82 equipped with two reflecting mirrors, a lens 83 that focuses the light, an imaging element 84 that converts the focused light into image data, and a contact glass 85 on which the document G is placed.

[0022] The basic document reading operation of document reading device 110 is as follows: When a user places document G on the upper surface of contact glass 85 and gives document reading instruction to document reading device 110, first carriage 81 moves to the right at speed V, and in conjunction with this, second carriage 82 moves to the right at speed V / 2. During this time, a light source irradiates light onto document G, and the light reflected by document G is reflected by the reflecting mirrors of first carriage 81 and second carriage 82 and directed to lens 83, where it is focused on image sensor 84 and converted into an image signal. The image signal is output to control unit 2 of printing device 1 and converted into image data.

[0023] [Document transport device] Next, the document transport device 120 will be described. Fig. 2 is a perspective view showing the appearance of the document transport device 120. Fig. 3 is a front view schematically showing the paper feed mechanism 31 and the transport mechanism 32. Figs. 4 and 6 are front views schematically showing the transport mechanism 32 and the paper feed tray lifting / lowering mechanism 33. Fig. 5 is a rear view schematically showing the paper feed tray lifting / lowering mechanism 33. Of these, Figs. 3, 4, and 5 show the paper feed tray 44 positioned near the upper limit position, and Fig. 6 shows the paper feed tray 44 positioned near the lower limit position.

[0024] The document transport device 120 (see FIGS. 2 and 3) has a flat, generally rectangular bottom 40, and a first wall 41 and a second wall 42 that face each other in the front-to-rear direction (the width direction intersecting with the feed direction Z of the document G). The rear edge of the bottom 40 is hinged to the rear of the contact glass 85 (see FIG. 1) of the document reading device 110. The bottom 40 also functions to hold down the document G on the contact glass 85. The first wall 41 is provided from the left end of the front edge of the bottom 40 to the center. The second wall 42 is provided across the entire rear edge of the bottom 40. The cover 46 covers the upper and left sides of the space between the first wall 41 and the second wall 42. The lower left end of the cover 46 is hinged to the left end of the bottom 40.

[0025] [Paper Tray] The paper feed tray 44 (see FIGS. 2 and 3) is provided to the right of the center in the left-right direction of the document transport device 120 and in front of the second wall portion 42. The paper feed tray 44 is a plate-shaped member that is inclined so that the left side is lower. A pair of cursors 45 that align the front-to-rear edges of the document G are provided on the top surface of the paper feed tray 44. The cursors 45 are slidable in the front-to-rear direction.

[0026] [Output tray] The discharge tray 43 is provided below the paper feed tray 44. The discharge tray 43 is integral with the bottom portion 40.

[0027] [Paper feed mechanism] The paper feed mechanism 31 (see FIG. 3) is provided in the space between the first wall portion 41 and the second wall portion 42. The paper feed mechanism 31 has a box-shaped holder 53 that is open at the bottom. Inside the holder 53, a feed roller 51, a driven roller 55, a drive roller 52, and a retard roller 57 are arranged with their axial direction aligned in the front-to-rear direction. The driven roller 55 is provided to the left of the feed roller 51. The drive roller 52 is provided to the left of the driven roller 55. The endless belt 56 is wound around the drive roller 52 and the driven roller 55. The retard roller 57 is pressed against the underside of the lower part of the endless belt 56.

[0028] The front and rear ends of the drive shaft 54 ​​of the drive roller 52 are supported by the first wall portion 41 and the second wall portion 42, and are connected to a drive unit (not shown) including a motor and a reduction gear. The holder 53 is supported by the drive shaft 54 ​​and can swing around the drive shaft 54. The driving force is transmitted from the drive shaft 54 ​​to the feed roller 51 and the retard roller 57 by a transmission mechanism (not shown), such as a gear train or an endless belt.

[0029] Sensor 58 is a transmission or reflection type optical sensor, and is provided on the inner surface of cover part 46. A light shielding plate 59 that protrudes upward or to the side is provided on the upper part of holder 53. Sensor 58 outputs a detection signal to control part 2 at a different level depending on whether light from sensor 58 is blocked by light shielding plate 59 or not.

[0030] [Paper feed tray lifting mechanism] The paper feed tray lifting mechanism 33 (see FIGS. 4 and 5) is provided on the front surface of the first wall portion 41 and the rear surface of the second wall portion 42. The drive pulley 71 and the driven pulley 72 (see FIG. 5) are provided at the upper and lower central portions of the rear surface of the second wall portion 42, respectively. The driven pulley 73 is provided at a height between the drive pulley 71 and the driven pulley 72 and to the left of the drive pulley 71 and the driven pulley 73. The guide pulley 76 is provided above and to the left of the driven pulley 72 and to the right of the driven pulley 73. The endless belt 70 is wound around the drive pulley 71, the driven pulleys 72 and 73, and the guide pulley 76. The drive unit 78 includes a motor 78M, a worm gear 78W, an idler gear 78i, and a drive gear 71G. The drive gear 71G is attached to the shaft of the drive pulley 71.

[0031] The driven pulleys 91, 92, 93 and the guide pulley 96 (see FIG. 4) are provided on the front surface of the first wall portion 41 at positions facing the drive pulley 71, the driven pulleys 72, 73 and the guide pulley 76, respectively. The endless belt 90 is wound around the driven pulleys 91, 92, 93 and the guide pulley 96. The driven pulley 93 and the driven pulley 73 are provided on a common shaft.

[0032] The sliding portion 74 (see FIG. 5) is provided at the left end of the rear edge of the paper feed tray 44. The second wall portion 42 is provided with a slit 42S with the vertical direction as the longitudinal direction. The slit 42S is provided at a position corresponding to the left end of the rear edge of the paper feed tray 44. The sliding portion 74 passes through the slit 42S and is coupled to a portion of the endless belt 70 between the drive pulley 71 and the driven pulley 72.

[0033] A lift guide 75 is provided on the rear surface of the second wall 42. The lift guide 75 is a rail-shaped member with its longitudinal direction extending in the vertical direction. The sliding part 74 is slidable in the vertical direction along the lift guide 75.

[0034] The sliding portion 94 (see FIG. 4) is provided at the left end of the front edge of the paper feed tray 44. The sliding portion 94 is coupled to the endless belt 90 at a portion between the driven pulley 91 and the driven pulley 92.

[0035] An elevation guide portion 95 is provided on the front surface of the first wall portion 41. The elevation guide portion 95 is a rail-shaped member whose longitudinal direction is the up-down direction. The sliding portion 94 is slidable in the up-down direction along the elevation guide portion 95.

[0036] The basic operation of the paper feed tray lifting mechanism 33 is as follows: The driving force generated by the motor 78M is transmitted to the drive gear 71G via the worm gear 78W and the idler gear 78i. The rotation of the drive pulley 71 together with the drive gear 71G causes the endless belt 70 to rotate, which in turn causes the driven pulleys 72 and 73 to rotate. The rotation of the driven pulley 93 together with the driven pulley 73 causes the endless belt 90 to rotate in synchronization with the endless belt 70. Because the paper feed tray 44 is connected to the endless belts 70 and 90 via the sliding portions 74 and 94, the forward and reverse rotation of the motor 78M causes the paper feed tray 44 to move up and down.

[0037] The control unit 2 causes the paper feed tray 44 to rise using the paper feed tray lifting mechanism 33. When the top surfaces of the documents G loaded on the paper feed tray 44 are pressed against the feed roller 51, the holder 53 swings upward. When the holder 53 swings upward by a predetermined amount, the light shielding plate 59 blocks the light from the sensor 58. At this time, an appropriate load acts between the top surfaces of the documents G and the feed roller 51, allowing the feed roller 51 to feed out the documents G. In other words, the control unit 2 controls the paper feed tray lifting mechanism 33 to raise the paper feed tray 44 as the amount of documents G loaded on the paper feed tray 44 decreases.

[0038] [Transport mechanism] The transport mechanism 32 (see FIG. 3) includes a transport path 61 extending from the paper feed mechanism 31 to a discharge roller 69 via an opening 40A, and a plurality of transport rollers 62 arranged on the transport path 61. The transport path 61 is formed primarily of plate-like members facing each other with a gap therebetween that allows the document G to pass through. The opening 40A is a slit with its longitudinal direction extending in the front-to-rear direction, provided in an area of ​​the bottom 40 that faces the first carriage 81 (see FIG. 1) located at the home position. The opening 40A is an example of a reading position A, where the document reading device 110 reads the document G. At the reading position A, an opening 61A corresponding to the opening 40A is provided in the plate-like member below the transport path 61, and the underside of the document G being transported is exposed downward through the opening 40A and the opening 61A.

[0039] The transport roller 62 includes a drive roller 62D and a driven roller 62N (see FIG. 3). A driven pulley 63N (see FIG. 4) is provided on the shaft of the drive roller 62D. The drive pulley 63D is connected to a drive unit (not shown) including a motor and a reduction gear. The endless belt 60 is wound around the drive pulley 63D, multiple driven pulleys 63N, and a guide pulley 63G. When the drive pulley 63D is driven, the multiple driven pulleys 63N rotate synchronously as the endless belt 60 rotates, and therefore the multiple transport rollers 62 also rotate synchronously.

[0040] A guide portion 64 (FIG. 3) is provided in a portion of the transport path 61 downstream of the opening 40A in the paper feed direction Z. The guide portion 64 is an integrated pair of plate-shaped members facing each other in the vertical direction, and can swing around the drive roller 62D or driven roller 62N of the transport roller 62 adjacent to the right side of the opening 40A. A description of the mechanism for swinging the guide portion 64 will be omitted.

[0041] [Configuration of fixed wall and lifting wall] Next, the configurations of the fixed wall portion 23 and the lift-up wall portion 25 will be described. Figures 7 to 9 are perspective views showing the fixed wall portion 23, the lift-up wall portion 25, and the paper feed tray 44. Of these, Figure 7 shows the lift-up wall portion 25 and the paper feed tray 44 in their lowest positions. Figure 8 shows the lift-up wall portion 25 in their highest position, and the paper feed tray 44 in their intermediate position. Figure 9 shows the lift-up wall portion 25 in their highest position, and the paper feed tray 44 in their highest position. Figures 10 and 11 are exploded views showing the fixed wall portion 23 and the lift-up wall portion 25.

[0042] The document transport device 120 includes a paper feed tray 44 on which documents G are loaded, a paper feed mechanism 31 that feeds the documents G loaded on the paper feed tray 44 in a predetermined paper feed direction Z, a paper feed tray lifting mechanism 33 that raises and lowers the paper feed tray 44, a top plate portion 22 that is adjacent to the paper feed tray 44 on the downstream side in the paper feed direction Z and with which the underside of the document G to be fed comes into contact, a fixed wall portion 23 that is provided below the upstream end of the top plate portion 22 in the paper feed direction Z and has a fixed position, and a lifting wall portion 25 that is provided above the downstream end of the paper feed tray 44 in the paper feed direction Z and rises and falls along the fixed wall portion 23 together with the paper feed tray 44.

[0043] [Top panel] The top panel 22 (see FIGS. 7 to 11) is disposed generally horizontally. An opening 22A is provided in the center of the top panel 22 in the front-to-rear direction. A retard roller 57 included in the paper feed mechanism 31 described above is disposed in the opening 22A. The document G fed by the feed roller 51 is transported along the upper surface of the top panel 22 while the lower surface of the document G contacts the upper surface of the top panel 22.

[0044] [Fixed wall] The fixed wall portion 23 is a rectangular member whose longitudinal direction is the front-to-rear direction as a whole, and is provided in an upright position downward from the upstream end of the top panel portion 22 in the paper feed direction Z and is integrated with the top panel portion 22. The fixed wall portion 23 includes a plurality of protrusions 23T1, 23T2, 23T3, 23T4, 23T5, 23T6, and 23T7 and a plurality of recesses 23U1, 23U2, 23U3, 23U4, 23U5, and 23U6. The plurality of protrusions 23T1 to 23T7 are provided at intervals along the upstream end of the top panel portion 22 in the paper feed direction Z, protrude toward the paper feed tray 44, and have a hollow structure with an open lower end. The plurality of recesses 23U1 to 23U6 are provided alternately with the plurality of protrusions 23T1 to 23T7. From the front side, the convex portion 23T1, the concave portion 23U1, the convex portion 23T2, the concave portion 23U2, the convex portion 23T3, the concave portion 23U3, the convex portion 23T4, the concave portion 23U4, the convex portion 23T5, the concave portion 23U5, the convex portion 23T6, the concave portion 23U6, and the convex portion 23T7 are arranged in this order.

[0045] The multiple protrusions 23T1 to 23T7 are formed in a generally rectangular parallelepiped shape with a smaller horizontal dimension than the vertical dimension. The upper ends of the multiple protrusions 23T1 to 23T7 and the multiple recesses 23U1 to 23U6 are inclined so that the height increases downstream in the paper feed direction Z. The shapes and dimensions of the multiple protrusions 23T1 to 23T7 may be different from each other as shown in the figures, or may be the same. Furthermore, the shapes and dimensions of the multiple recesses 23U1 to 23U6 may be different from each other as shown in the figures, or may be the same.

[0046] [Restriction section] The side wall portion 23W is provided in an upright position downward from both the front and rear ends of the top plate portion 22. The side wall portion 23W is integrated with the top plate portion 22 and the fixed wall portion 23. The limiting portion 23R is a slit provided in the side wall portion 23W along the up-down direction. The upper end of the limiting portion 23R is closed and the lower end is open.

[0047] [Lifting wall section] The bottom plate 24 faces the top plate 22 below the top plate 22. The lift-up wall 25 is provided in an upright position extending upward from the upstream end of the bottom plate 24 in the paper feed direction Z and is integrated with the bottom plate 24. The lift-up wall 25 includes a plurality of protrusion fitting portions 25T1, 25T2, 25T3, 25T4, 25T5, 25T6, and 25T7 and a plurality of recess fitting portions 25U1, 25U2, 25U3, 25U4, 25U5, and 25U6. The protrusion fitting portions 25T1, 25T2, 25T3, 25T4, 25T5, 25T6, and 25T7 fit into the insides of the protrusions 23T1, 23T2, 23T3, 23T4, 23T5, 23T6, and 23T7, respectively. The recessed portion fitting portions 25U1, 25U2, 25U3, 25U4, 25U5, and 25U6 fit into the insides of the recessed portions 23U1, 23U2, 23U3, 23U4, 23U5, and 23U6, respectively. As the paper feed tray 44 moves up and down, the protruding portion fitting portions 25T1 to 25T7 slide along the protruding portions 23T1 to 23T7, and the recessed portion fitting portions 25U1 to 25U6 slide along the recessed portions 23U1 to 23U6.

[0048] End The front and rear end portions 25E of the lift-up wall portion 25 are inserted into the aforementioned limiting portion 23R and slide along the limiting portion 23R. Because the upper end portion of the limiting portion 23R is closed, the lift-up wall portion 25 stops moving upward when the end portion 25E comes into contact with the upper end portion of the limiting portion 23R. When the end portion 25E comes into contact with the upper end portion of the limiting portion 23R, the upper end portion of the lift-up wall portion 25 becomes flush with the upper end portion of the fixed wall portion 23. The protrusions 25B protrude in the front-rear direction from the front and rear end portions 25E of the lift-up wall portion 25.

[0049] [Biasing member] The biasing member 26 (see FIGS. 10 and 11) is a tension coil spring arranged in an upright position between the top plate portion 22 and the bottom plate portion 24. The upper end of the biasing member 26 is attached to the underside of the top plate portion 22, and the lower end is attached to the upper surface of the bottom plate portion 24. Because the top plate portion 22 is fixed, the bottom plate portion 24 and the lift-up wall portion 25 are biased upward.

[0050] [Engagement part] FIG. 12 is a perspective view showing a cross section of the lift-up wall portion 25 and the front portion of the paper feed tray 44. The engagement portions 44R (see FIG. 12) protrude in the paper feed direction Z from both the front and rear ends of the downstream end of the paper feed tray 44 in the paper feed direction Z. While only the front engagement portion 44R is shown in the figure, the rear engagement portion 44R is configured in the same way. The engagement portion 44R has a recess 44G that opens downward. By accommodating the protrusion 25B of the lift-up wall portion 25 in the recess 44G, the engagement portion 44R engages with the protrusion 25B.

[0051] As described above, the lift-up wall portion 25 is biased upward by the biasing member 26, so that the protrusion 25B is pressed against the recess 44G. This configuration restricts the lift-up wall portion 25 from rising, and the lift-up wall portion 25 is kept protruding upward by a predetermined height from the downstream end of the paper feed tray 44 in the paper feed direction Z.

[0052] Next, the operation of this embodiment will be described. When the lift-up wall portion 25 is located at the lowest position (see FIG. 7), the upper end of the lift-up wall portion 25 is located slightly higher than the lower end of the fixed wall portion 23, so that no gap is created in the vertical direction between the lift-up wall portion 25 and the fixed wall portion 23. In this case, the height of the wall formed by the lift-up wall portion 25 and the fixed wall portion 23 is at its maximum, and the capacity of the paper feed tray 44 (the amount of documents G that can be loaded) is at its maximum.

[0053] Because the lifting wall 25 is biased upward by the biasing member 26, when the sheet feed tray 44 is raised by the sheet feed tray lifting mechanism 33, the lifting wall 25 also rises together with the sheet feed tray 44. At this time, the convex portion fitting portions 25T1 to 25T7 of the lifting wall 25 slide along the convex portions 23T1 to 23T7 of the fixed wall 23, and the concave portion fitting portions 25U1 to 25U6 of the lifting wall 25 slide along the concave portions 23U1 to 23U6 of the fixed wall 23.

[0054] When both front and rear ends 25E of the lift-up wall 25 come into contact with the upper end of the limiting portion 23R (see FIG. 8), the lift-up wall 25 stops rising and reaches the upper limit position. At this time, the paper feed tray 44 is located at an intermediate position between the lower limit position and the upper limit position. When the paper feed tray 44 rises further, the recess 44G of the engaging portion 44R separates from the protrusion 25B of the lift-up wall 25, and only the paper feed tray 44 rises.

[0055] When the paper feed tray 44 reaches its upper limit position (see FIG. 9), the downstream end of the top surface of the paper feed tray 44 in the paper feed direction Z is positioned slightly lower than the top surface of the top plate 22. In this case, the height of the wall formed by the lift-up wall 25 and the fixed wall 23 is minimized, and the capacity of the paper feed tray 44 is minimized. As described above, the upper ends of the convex portions 23T1 to 23T7 and concave portions 23U1 to 23U6 of the fixed wall 23 are inclined so that the downstream side in the paper feed direction Z is higher, so that the document G is smoothly fed from the paper feed tray 44 toward the top plate 22.

[0056] When the paper feed tray 44 starts to descend from the upper limit position and reaches the intermediate position (see FIG. 8), the recess 44G of the engagement portion 44R comes into contact with the protrusion 25B of the lift-up wall portion 25. When the paper feed tray 44 further descends, the recess 44G presses down the protrusion 25B, and the lift-up wall portion 25 descends together with the paper feed tray 44.

[0057] The document transport device 120 according to the present embodiment described above includes a paper feed tray 44 on which documents G are stacked, a paper feed mechanism 31 that feeds the documents G stacked on the paper feed tray 44 in a predetermined paper feed direction Z, a paper feed tray lifting mechanism 33 that lifts and lowers the paper feed tray 44, a top plate 22 adjacent to the paper feed tray 44 on the downstream side in the paper feed direction Z and with which the underside of the fed documents G comes into contact, a fixed wall 23 that is provided below the upstream end of the top plate 22 in the paper feed direction Z and is fixed in position, and a lifting wall 25 that is provided above the downstream end of the paper feed tray 44 in the paper feed direction Z and lifts and lowers together with the paper feed tray 44 along the fixed wall 23. With this configuration, the downstream end of the documents G in the paper feed direction Z is positioned by a wall formed by the fixed wall 23 and the lifting wall 25. As the paper feed tray 44 is lowered, the height of the wall increases, thereby increasing the capacity of the paper feed tray 44. Therefore, according to this embodiment, the capacity of the paper feed tray 44 can be increased without increasing the vertical size of the wall on the downstream side in the paper feed direction Z of the paper feed tray 44. As a result, the height of the discharge opening through which the document G is discharged onto the discharge tray 43 can be changed over a wide range, and the capacity of the discharge tray 43 can also be increased.

[0058] Furthermore, according to the document transport device 120 of this embodiment, the fixed wall portion 23 is provided with a plurality of convex portions 23T1 to 23T7 arranged at intervals along the upstream end of the top plate portion 22 in the paper feed direction Z, protruding toward the paper feed tray 44, and having a hollow structure with an open lower end, and a plurality of concave portions 23U1 to 23U6 arranged alternately with the plurality of convex portions 23T1 to 23T7, and the lifting wall portion 25 is provided with a plurality of convex portion fitting portions 25T1 to 25T7 that fit inside the plurality of convex portions 23T1 to 23T7, and a plurality of concave portion fitting portions 25U1 to 25U6 that fit inside the plurality of concave portions 23U1 to 23U6. According to this configuration, the plurality of convex engaging portions 25T1 to 25T7 slide against the plurality of convex portions 23T1 to 23T7, and the plurality of concave engaging portions 25U1 to 25U6 slide against the plurality of concave portions 23U1 to 23U6, so that the lifting wall portion 25 can be raised and lowered smoothly and in a stable posture.

[0059] Furthermore, the document transport device 120 according to this embodiment includes the biasing member 26 that biases the lifting wall portion 25 upward, and the paper feed tray 44 includes the engagement portion 44R that restricts the lifting of the lifting wall portion 25. With this configuration, the lifting wall portion 25 can be kept protruding upward by a predetermined height from the downstream end of the paper feed tray 44 in the paper feed direction Z.

[0060] Furthermore, according to the document transport device 120 of this embodiment, the fixed wall portion 23 includes a limiting portion 23R that limits the elevation of the lifting wall portion 25 so that the height of the upper end of the lifting wall portion 25 does not exceed the height of the upper end of the fixed wall portion 23. This configuration makes it possible to prevent the lifting wall portion 25 from interfering with the transport of the document G.

[0061] Furthermore, according to the document transport device 120 of this embodiment, the paper feed tray 44 can be raised to a predetermined height above the position of the paper feed tray 44 when the lift-up wall portion 25 reaches the upper limit position. With this configuration, even if the number of documents G stacked on the paper feed tray 44 is small, the documents can be fed.

[0062] [Second embodiment] Next, a document transport device 120 according to a second embodiment of the present invention will be described in comparison with the first embodiment. Fig. 16 is a view of the fixed wall 23, the lift-up wall 25, and the paper feed tray 44 according to the first embodiment, viewed from diagonally above right. This figure shows the lift-up wall 25 and the paper feed tray 44 in their lowest positions (see Fig. 7). The fixed wall 23, the lift-up wall 25, and the paper feed tray 44 are formed roughly symmetrically in the front-to-rear direction, so as shown in Fig. 16, only the portions forward of the center in the front-to-rear direction will be described.

[0063] In the first embodiment, as described above, the protrusion fitting portions 25T1, 25T2, and 25T3 fit into the insides of the protrusions 23T1, 23T2, and 23T3, respectively. Therefore, when the paper feed tray 44 is raised to the intermediate position (see FIG. 8), gaps A1, A2, and A3 (see FIG. 16) are provided on the upstream side of the protrusion fitting portions 25T1, 25T2, and 25T3 in the paper feed direction Z to prevent interference between the protrusions 23T1, 23T2, and 23T3 and the main body 44M of the paper feed tray 44.

[0064] When the paper feed tray 44 is raised to the intermediate position or higher (see FIGS. 8 and 9), the gaps A1, A2, and A3 are blocked by the protrusions 23T1, 23T2, and 23T3. However, when the paper feed tray 44 is lowered below the intermediate position (see FIG. 7), the gaps A1, A2, and A3 are exposed (see FIG. 16), which may cause foreign matter to enter the gaps A1, A2, and A3. Therefore, the document transport device 120 according to the second embodiment is configured as follows.

[0065] 13 is an exploded view showing the fixed wall portion 27 and the lift-up wall portion 29 according to the second embodiment. Below, differences between the second embodiment and the first embodiment will be described.

[0066] The document transport device 120 includes a paper feed tray 44 on which documents G are loaded, a paper feed mechanism 31 that feeds the documents G loaded on the paper feed tray 44 in a predetermined paper feed direction Z, a paper feed tray lifting mechanism 33 that lifts and lowers the paper feed tray 44, a top plate 22 that is provided downstream of the paper feed tray 44 in the paper feed direction Z and that comes into contact with the underside of the document G being fed, a fixed wall 27 that is provided below the end of the top plate 22 on the upstream side in the paper feed direction Z and that is fixed in position, and a fixed wall 28 that is provided above the end of the paper feed tray 44 on the downstream side in the paper feed direction Z and that is fixed in position. and a lifting wall portion 29 that faces the fixed wall portion 27 upstream of the paper feed tray 44 in the paper feed direction Z and that lifts and lowers together with the paper feed tray 44 along the fixed wall portion 27, the lifting wall portion 29 having slits 29S1 to 29S10 that run along the vertical direction, the fixed wall portion 27 having fins 27F1 to 27F10 that run along the vertical direction, the upper ends of the slits 29S1 to 29S10 that open in the vertical direction, and the fins 27F1 to 27F10 that protrude upstream in the paper feed direction Z and are arranged inside the slits 29S1 to 29S10.

[0067] The fixed wall portion 27 replaces the fixed wall portion 23 of the first embodiment. The fixed wall portion 27 includes a main body portion 27A and a plurality of fins 27F1 to 27F10 instead of the plurality of protrusions 23T1 to 23T7 and the plurality of recesses 23U1 to 23U6 of the first embodiment. The side wall portion 27W and the limiting portion 27R have the same functions as the side wall portion 23W and the limiting portion 23R of the first embodiment.

[0068] The main body 27A is a generally rectangular plate-like portion with its thickness in the left-right direction and its length in the front-rear direction. The fins 27F1, 27F2, 27F3, 27F4, 27F5, 27F6, 27F7, 27F8, 27F9, and 27F10 are plate-like portions with their length in the up-down direction and their thickness in the front-rear direction. The fins 27F1 to 27F10 are provided on the right surface (the surface upstream in the paper feed direction Z) of the main body 27A and protrude to the right (upstream side in the paper feed direction Z). The fins 27F1 to 27F10 are provided at multiple locations in the front-rear direction (the width direction of the document G, which intersects with the paper feed direction Z). The upper ends of the fins 27F1 to 27F10 are inclined so that the downstream side in the paper feed direction Z is higher. The left ends of the upper ends of the fins 27F1 to 27F10 are smoothly connected to the top panel 22.

[0069] The lift-up wall portion 29 replaces the lift-up wall portion 25 of the first embodiment. The lift-up wall portion 29 includes a main body portion 29A and a plurality of slits 29S1 to 29S10 instead of the plurality of convex portion fitting portions 25T1 to 25T7 and the plurality of concave portion fitting portions 25U1 to 25U6 of the first embodiment. The end portion 29E and the protrusion portion 29B have the same functions as the end portion 25E and the protrusion portion 25B of the first embodiment.

[0070] The main body 29A is a generally rectangular plate-like portion with its thickness in the left-right direction and its length in the front-rear direction. Slits 29S1, 29S2, 29S3, 29S4, 29S5, 29S6, 29S7, 29S8, 29S9, and 29S10 are provided at multiple locations in the front-rear direction, and fins 27F1 to 27F10 are provided at multiple locations corresponding to the slits 29S1 to 29S10. The slits 29S1 to 29S10 have their length in the up-down direction and penetrate in the left-right direction. The upper ends of the slits 29S1 to 29S10 are open in the up-down direction. The fins 27F1 to 27F10 are each disposed inside the slits 29S1 to 29S10.

[0071] The arrangement of the multiple fins 27F1 to 27F10 and the multiple slits 29S1 to 29S10 is determined according to the size of the originals G that are expected to be read by the original transport device 120. The originals G are loaded in the center of the front-to-rear direction of the paper feed tray 44. When originals G of the minimum size (e.g., A6) are loaded with their long sides parallel to the paper feed direction Z, the two fins 27F5 and 27F6 closest to the center come into contact with the short sides of the originals G. When originals G of the maximum size (e.g., A3) are loaded with their long sides parallel to the paper feed direction Z, all of the fins 27F1 to 27F10 come into contact with the short sides of the originals G. In other words, the multiple fins 27F1 to 27F10 and the multiple slits 29S1 to 29S10 are arranged so that at least two fins come into contact with the originals G loaded in the paper feed tray 44.

[0072] Edges 29R of the slits 29S1 to 29S10 protrude upstream in the paper feed direction Z. The tips of the fins 27F1 to 27F10 and the tips of the edges 29R on both sides of the fins 27F1 to 27F10 form approximately the same plane.

[0073] FIG. 14 is a perspective view showing the state in which the lift-up wall portion 29 according to the second embodiment is located at its lowest position. At this time, the paper feed tray 44 is located at its lowest position (the position corresponding to FIG. 7 of the first embodiment), and the capacity of the paper feed tray 44 is at its maximum. When the lift-up wall portion 29 is located at its lowest position, the lower ends of the fins 27F1 to 27F10 are located slightly lower than the upper ends of the slits 29S1 to 29S10. In other words, the lower ends of the fins 27F1 to 27F10 are inserted into the slits 29S1 to 29S10. Of the stacked documents G, those facing the lift-up wall portion 29 come into contact with the edges 29R of the slits 29S1 to 29S10, and those facing the fixed wall portion 27 come into contact with the fins 27F1 to 27F10. The tips of the fins 27F1 to 27F10 and the tips of the edge portions 29R on both sides of the fins 27F1 to 27F10 form roughly the same plane, so that the downstream ends of the documents G in the paper feed direction Z are aligned.

[0074] 15 is a perspective view showing the state in which the lift-up wall portion 29 according to the second embodiment is located at the uppermost position. At this time, the paper feed tray 44 is located at a height equal to or higher than the intermediate position (the position corresponding to FIG. 8 in the first embodiment). When the lift-up wall portion 29 is located at the uppermost position, the entire fins 27F1 to 27F10 are inserted into the slits 29S1 to 29S10. Because the tips of the fins 27F1 to 27F10 and the tips of the edge portions 29R on both sides of the fins 27F1 to 27F10 are generally flush with each other, the stacked documents G come into contact with the fins 27F1 to 27F10 and the edge portions 29R on both sides of the fins 27F1 to 27F10.

[0075] 17 is a view of the fixed wall portion 27, the lift-up wall portion 29, and the paper feed tray 44 according to the second embodiment, viewed from diagonally above to the right. This figure shows the lift-up wall portion 29 and the paper feed tray 44 in their lowest positions. In this embodiment, the main body portion 29A of the lift-up wall portion 29 faces the main body portion 27A of the fixed wall portion 27 on the upstream side in the paper feed direction Z of the main body portion 27A of the fixed wall portion 27, and fins 27F1 to 27F10 are disposed inside the slits 29S1 to 29S10. Therefore, there is no need to provide gaps like the gaps A1, A2, and A3 of the first embodiment on the upstream side in the paper feed direction Z of the main body portion 29A of the lift-up wall portion 29. Furthermore, when the lifting wall portion 29 is lowered below the upper limit position, the gaps B1, B2, B3, B4 of the slits 29S1, 29S2, 29S3, 29S4 are smaller than the gaps A1, A2, A3 in the first embodiment, so that the possibility of foreign matter entering the gaps B1, B2, B3, B4 is reduced.

[0076] According to the document transport device 120 of the present embodiment described above, there are provided the sheet feed tray 44 on which the documents G are stacked, the sheet feed mechanism 31 that feeds the documents G stacked on the sheet feed tray 44 in the predetermined sheet feed direction Z, the sheet feed tray lifting mechanism 33 that lifts and lowers the sheet feed tray 44, the top plate 22 that is provided downstream of the sheet feed tray 44 in the sheet feed direction Z and that comes into contact with the underside of the fed document G, the fixed wall 27 that is provided below the end of the top plate 22 on the upstream side in the sheet feed direction Z and that is fixed in position, and the fixed wall 27 that is provided above the end of the sheet feed tray 44 on the downstream side in the sheet feed direction Z. and a lifting wall portion 29 that faces the fixed wall portion 27 upstream in the paper feed direction Z and moves up and down along the fixed wall portion 27 together with the paper feed tray 44, the lifting wall portion 29 having slits 29S1 to 29S10 extending in the vertical direction, the fixed wall portion 27 having fins 27F1 to 27F10 extending in the vertical direction, the upper ends of the slits 29S1 to 29S10 opening in the vertical direction, and the fins 27F1 to 27F10 protruding upstream in the paper feed direction Z and positioned inside the slits 29S1 to 29S10.

[0077] According to this embodiment, the capacity of the paper feed tray 44 can be increased without increasing the vertical size of the wall on the downstream side in the paper feed direction Z of the paper feed tray 44. Also, in the first embodiment, gaps A1, A2, A3 (see FIG. 16) are provided on the upstream side of the protrusion fitting portions 25T1, 25T2, 25T3 in the paper feed direction Z to prevent interference between the protrusions 23T1, 23T2, 23T3 and the main body portion 44M of the paper feed tray 44 when the paper feed tray 44 is raised to the intermediate position (see FIG. 8). However, in this embodiment, there is no need to provide a gap between the lift-up wall portion 29 and the paper feed tray 44, so that foreign matter can be prevented from entering between the lift-up wall portion 29 and the paper feed tray 44.

[0078] Furthermore, according to the document transport device 120 of this embodiment, the slits 29S1 to 29S10 are provided at a plurality of locations in the width direction of the document G that intersects with the paper feed direction Z, and the fins 27F1 to 27F10 are provided at a plurality of locations corresponding to the slits 29S1 to 29S10, respectively, so that at least two fins come into contact with the document G loaded on the paper feed tray 44. According to this embodiment, the document G can be aligned parallel to the paper feed direction Z.

[0079] Furthermore, according to the document transport device 120 of this embodiment, the edges 29R of the slits 29S1 to 29S10 protrude upstream in the paper feed direction Z, and the tips of the fins 27F1 to 27F10 and the tips of the edges 29R on both sides of the fins 27F1 to 27F10 form the same plane. According to this embodiment, the document G is supported over a larger area than if the document G were supported only by the fins 27F1 to 27F10, and therefore the posture of the document G can be stabilized.

[0080] Furthermore, in the document transport device 120 according to this embodiment, the upper ends of the fins 27F1 to 27F10 are inclined so that the height increases downstream in the paper feed direction Z. According to this embodiment, the document G can be smoothly sent from the paper feed tray 44 to the top panel 22 via the upper ends of the fins 27F1 to 27F10. [Explanation of symbols]

[0081] 22 Top plate 27 Fixed wall section 27F1 to 27F10 Fins 29 Lifting wall 29S1 to 29S10 Slits 29R edge 31 Paper feed mechanism 33 Paper feed tray lifting mechanism G Manuscript Z feed direction

Claims

1. a paper feed tray on which documents are loaded; a paper feed mechanism that feeds documents loaded on the paper feed tray in a predetermined paper feed direction; a paper feed tray lifting mechanism for lifting and lowering the paper feed tray; a top plate portion provided downstream of the paper feed tray in the paper feed direction and contacting the underside of the document to be fed; a fixed wall portion provided below an end portion of the top plate portion on the upstream side in the paper feed direction and fixed in position; a lifting wall portion that is provided above an end portion of the paper feed tray on the downstream side in the paper feed direction, faces the fixed wall portion on the upstream side in the paper feed direction of the fixed wall portion, and lifts and lowers together with the paper feed tray along the fixed wall portion, The lifting wall portion has a slit extending in the up-down direction, The fixed wall portion has fins extending in the vertical direction, The upper end of the slit is open in the vertical direction, The document transport device is characterized in that the fin protrudes upstream in the paper feed direction and is disposed inside the slit.

2. the slits are provided at a plurality of locations in a width direction of the document that intersects with the paper feed direction, The fins are provided at a plurality of locations corresponding to the slits, 2. The document transport device according to claim 1, wherein at least two of the fins come into contact with the documents loaded on the paper feed tray.

3. an edge of the slit protrudes upstream in the paper feed direction; 3. The document transport device according to claim 1, wherein the tip of the fin and the tips of the edges on both sides of the fin form the same plane.

4. 2. The document transport device according to claim 1, wherein the upper end of the fin is inclined so that the downstream side in the paper feed direction is higher.

Images