Sheet transport device

Abstract

The purpose is to suppress abnormal noises caused by paper dust being rubbed against the separation rollers and separation pads. [Solution] The sheet transport device comprises a feed roller that feeds sheets from a paper tray in a predetermined transport direction Z, a separation pad 48 provided downstream of the feed roller in the transport direction Z, a separation roller that holds the sheets fed by the feed roller between itself and the separation pad 48 and transports them in the transport direction Z, and a groove 48A provided on the surface of the separation pad 48 that comes into contact with the sheets.

Description

Technical Field

[0001] The present invention relates to a sheet conveying device.

Background Art

[0002] There is known a document conveying device that conveys a document along a conveyance path passing through a reading position of a document reading device. The document conveying device includes a tray on which documents are stacked and a feeding roller that feeds out the documents from the tray. The feeding roller contacts the documents stacked on the tray. However, when the feeding roller is worn or when the documents are stuck to each other due to static electricity or the like, there is a possibility that double feeding occurs, in which two or more documents are fed out in an overlapping state. Therefore, conventionally, techniques for separating double-fed documents have been studied. For example, in the document conveying device disclosed in Patent Document 1, a separating roller and a separating pad are provided on the downstream side in the feeding direction from the feeding roller. By sandwiching and conveying the document between the separating roller and the separating pad, the double-fed document is separated.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the configuration disclosed in Patent Document 1, when paper dust is caught between the separating roller and the separating pad during a period when the document is not sandwiched between the separating roller and the separating pad, there is a possibility that the paper dust rubs against the separating roller or the separating pad and abnormal noise occurs.

[0005] In consideration of the above circumstances, an object of the present invention is to suppress abnormal noise generated by paper dust rubbing against a separating roller or a separating pad.

Means for Solving the Problems

[0006] To solve the above problems, the sheet transport device according to the present invention comprises a feed roller that feeds sheets from a paper tray in a predetermined transport direction, a separation pad provided downstream of the feed roller in the transport direction, a separation roller that holds the sheets fed by the feed roller between itself and the separation pad and transports them in the transport direction, and a groove provided on the surface of the separation pad that comes into contact with the sheets.

[0007] The groove may be formed in a straight line along the conveying direction.

[0008] Multiple types of the aforementioned separation pads, each with different groove specifications, may be interchangeable.

[0009] The system may also include a separation pad holder for holding the separation pad, and a transport guide member for guiding the transport of the sheet and for detachably supporting the separation pad holder. [Effects of the Invention]

[0010] According to the present invention, it is possible to suppress abnormal noises that occur when paper dust is rubbed against the separation roller or separation pad. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view showing the external appearance of an image forming system according to one embodiment of the present invention. [Figure 2] This is a schematic front view showing the configuration of a document transport device and a document reading device according to one embodiment of the present invention. [Figure 3] This is a schematic right-side view showing the configuration of a printing apparatus according to one embodiment of the present invention. [Figure 4] This is a cross-sectional view showing the configuration of a document transport device according to one embodiment of the present invention. [Figure 5] This is a cross-sectional view showing a dispensing unit and a separation pad according to one embodiment of the present invention. [Figure 6]A cross-sectional view showing a feeding unit and a separation pad according to an embodiment of the present invention. [Figure 7] A cross-sectional view showing a feeding unit and a separation pad according to an embodiment of the present invention. [Figure 8] A perspective view showing a cross-section of a conveyance guide member and a separation pad according to an embodiment of the present invention. [Figure 9] A perspective view showing a cross-section of a conveyance guide member and a separation pad according to an embodiment of the present invention. [Figure 10] A perspective view showing a feeding unit according to an embodiment of the present invention. [Figure 11] A perspective view showing a separation pad holder according to an embodiment of the present invention. [Figure 12] A perspective view showing a separation pad holder according to an embodiment of the present invention. [Figure 13] A front view showing a separation pad holder according to an embodiment of the present invention. [Figure 14] A perspective view showing a separation pad according to an embodiment of the present invention. [Figure 15] A perspective view showing a separation pad according to an embodiment of the present invention. [Figure 16] A perspective view showing a separation pad according to an embodiment of the present invention. [Figure 17] A front view showing a state where a separation pad holder according to an embodiment of the present invention is flipped up. [Figure 18] A front view showing a state where a separation pad holder is removed from a hinge shaft according to an embodiment of the present invention.

Embodiments for Carrying Out the Invention

[0012] Hereinafter, an image forming system 100 according to an embodiment of the present invention will be described while referring to the drawings.

[0013] FIG. 1 is a perspective view showing the appearance of the image forming system 100. FIG. 2 is a front view schematically showing the configurations of the document conveying device 120 and the document reading device 110. FIG. 3 is a right side view schematically showing the configuration of the printing device 1. In each figure, U, Lo, L, R, Fr, and Rr indicate up, down, left, right, front, and rear, respectively. Note that these directions are merely defined for convenience of explanation.

[0014] The image forming system 100 (see FIG. 1) includes a printing device 1, a document reading device 110, and a document conveying device 120. The document reading device 110 is provided above the printing device 1, and the document conveying device 120 is provided above the document reading device 110. The document conveying device 120 conveys the document through the reading position of the document reading device 110. The document reading device 110 is a flatbed type image scanner that reads the document and generates image data. The printing device 1 forms an image based on the image data on a sheet S. The document conveying device 120 is an example of the sheet conveying device according to the present invention. The document is an example of the sheet conveyed by the sheet conveying device.

[0015] [Printing Device] The printing device 1 (see FIG. 3) includes a rectangular parallelepiped main body housing 3. Inside the lower part of the main body housing 3, a paper feed cassette 4 for accommodating the sheet S and a paper feed roller 5 for feeding the sheet S rearward from the paper feed cassette 4 are provided. Above the paper feed cassette 4, an image forming device 6 for forming a toner image by an electrophotographic method is provided, and above the rear of the image forming device 6, a fixing device 7 for fixing the toner image on the sheet S is provided. Above the fixing device 7, a discharge roller 8 for discharging the sheet S on which the toner image is fixed and a discharge tray 9 on which the discharged sheet S is stacked are provided.

[0016] Inside the main housing 3, a transport path 10 is provided, which runs from the paper feed roller 5 through the image creation device 6 and the fixing device 7 to the discharge roller 8. The transport path 10 is mainly formed of plate-shaped members that face each other with gaps between them to allow the sheet S to pass through, and transport rollers 17 that grip and transport the sheet S are provided at multiple locations in the transport direction Y. A registration roller 18 is provided upstream of the image creation device 6 in the transport direction Y. To the right of the fixing device 7, a reversal transport path 10R is provided. The reversal transport path 10R branches off from the transport path 10 at a branching point located downstream of the fixing device 7 in the transport direction Y, and rejoins the transport path 10 at a confluence point located upstream of the registration roller 18 in the transport direction Y.

[0017] The imaging device 6 comprises four sets of imaging units 6U and an intermediate transfer unit 15. Each imaging unit 6U includes a photoreceptor drum 11 whose potential changes upon irradiation with light, a charging device 12 that charges the photoreceptor drum 11, an exposure device 13 that emits laser light corresponding to the image data, a developing device 14 that supplies toner to the photoreceptor drum 11, and a cleaning device 16 that removes toner remaining on the photoreceptor drum 11. The intermediate transfer unit 15 includes an endless intermediate transfer belt 15B wrapped around a drive roller 15D and a driven roller 15N, a primary transfer roller 151 that faces the inner surface of the intermediate transfer belt 15B at a position corresponding to the photoreceptor drum 11 and generates a primary transfer bias, and a secondary transfer roller 152 that faces the outer surface of the intermediate transfer belt 15B at a position corresponding to the drive roller 15D and generates a secondary transfer bias. A toner container 20 that supplies toner to the developing device 14 is connected to the developing device 14. The imaging device 6 forms a color image by superimposing four-color toner images onto the intermediate transfer belt 15B. The printing device 1 may be equipped with two, three, or five or more imaging units 6U.

[0018] [Document scanning device] The document reading device 110 (see Figure 2) comprises a rectangular housing 30, a first carriage 32 equipped with a light source and a reflector, a second carriage 33 equipped with two reflectors, a lens 34A for imaging light, an image sensor 34 for converting the imaged light into image data, and a contact glass 31 on which the sheet G is placed. The contact glass 31 is provided on the upper surface of the housing 30.

[0019] [Document transport device] Figure 4 is a cross-sectional view showing the configuration of the document transport device 120. Figures 5 to 7 are cross-sectional views showing the feed unit 40 and the separation pad 48. Figures 8 and 9 are perspective views showing a cross-section of the transport guide member 39A and the separation pad 48. Figure 10 is a perspective view showing the feed unit 40. Figures 11 and 12 are perspective views showing the separation pad holder 50. Figure 13 is a front view showing the separation pad holder 50. Figures 14 to 16 are perspective views showing the separation pad 48. Figure 17 is a front view showing the separation pad holder 50 in the flipped-up position. Figure 18 is a front view showing the separation pad holder 50 removed from the hinge shaft 55.

[0020] The document transport device 120 (see Figures 2 and 4) is equipped with a generally rectangular bottom plate 35 formed in a flattened shape. The rear end of the bottom plate 35 is connected to the rear portion of the contact glass 31 on the upper surface of the housing 30 via a hinge (not shown), and the bottom plate 35 can be opened and closed around the hinge. The bottom plate 35 serves both to support the various parts of the document transport device 120 and to hold down the sheet G on the contact glass 31.

[0021] The document transport device 120 comprises a paper feed tray 36, a transport unit 38, and an output tray 37. The paper feed tray 36 is located from near the center to the right end of the document transport device 120. The paper feed tray 36 is inclined so that the left side is lower, and is equipped with a cursor 36A for aligning the front and rear edges of the sheet G. The output tray 37 is located below the paper feed tray 36. The output tray 37 is inclined so that the left side is lower.

[0022] [Conveying Section] The transport unit 38 comprises a feeding unit 40, a drive roller 41, a supply roller 42, an discharge roller 43, and a transport path 39. The feeding unit 40 is located above and to the left of the left end of the paper feed tray 36, and near the center of the paper feed tray 36 in the front-to-back direction. The drive roller 41, supply roller 42, and discharge roller 43 are arranged with the front-to-back direction as their axial direction. The drive roller 41 is located below and to the left of the feeding unit 40. The supply roller 42 is located above the drive roller 41. The discharge roller 43 is located below the drive roller 41. The supply roller 42 and the discharge roller 43 are in contact with the drive roller 41. The drive roller 41 is driven by a driving force transmitted from a motor 45 via a gear train (not shown), and the supply roller 42 and the discharge roller 43 are driven by the drive roller 41.

[0023] The bottom plate 35 has an opening 35A. The opening 35A is located in the area facing the first carriage 32 in the home position, and is an elongated rectangle in the front-to-back direction, penetrating in the vertical direction. The transport section 38 is covered by an outer cover 38A. The lower left part of the outer cover 38A is connected to the left end of the bottom plate 35 via a hinge 38B, and the outer cover 38A can be opened and closed using the hinge 38B as a pivot point. The upper right part of the outer cover 38A faces the upstream end of the transport guide member 39A in the transport direction Z.

[0024] [Transport route] The transport path 39 extends to the left from the contact area between the supply roller 42 and the drive roller 41, passes over the opening 35A, curves downward, and reaches the discharge roller 43 via the opening 35A. The transport path 39 is formed by plate-shaped transport guide members 39A and 39B (see Figure 4). Transport guide member 39A (see Figure 8) faces the lower surface of the sheet G fed out by the feed unit 40. Transport guide member 39B faces the upper surface of the sheet G fed out by the feed unit 40. The upstream end of transport guide member 39A in the transport direction Z extends further upstream in the transport direction Z than the feed unit 40 and is adjacent to the downstream end of the paper feed tray 36 in the transport direction Z. Transport guide member 39B is provided downstream in the transport direction Z than the feed unit 40. The transport path 39 is provided with one or more transport rollers 44 whose axial direction is in the front-rear direction.

[0025] [Dispensing mechanism] The dispensing section 40 (see Figures 5 and 10) is located on the inner surface (bottom surface) of the upper right part of the outer cover 38A and faces the upstream portion of the transport guide member 39A in the transport direction Z. The dispensing section 40 is positioned near the center in the front-rear direction of the transport path 39. The dispensing section 40 comprises a dispensing roller 46 and a separation roller 47 located to the left of the dispensing roller 46. The dispensing roller 46 is supported by a holder 40A. The holder 40A is supported by the outer cover 38A via the shaft 47A of the separation roller 47 and is capable of swinging up and down about the shaft 47A.

[0026] The separation roller 47 is driven by a driving force transmitted from the motor 45 via a gear train (not shown). The feed roller 46 is driven by a driving force transmitted from the separation roller 47 via a gear train 46A. The separation roller 47 has a shaft 47A, a first layer 47B provided around the shaft 47A, and a second layer 47C provided around the first layer 47B. The first layer 47B is made of, for example, polyacetal. The second layer 47C is made of, for example, silicone rubber. The outer surface of the second layer 47C is knurled (see Figure 10). The shape of the knurling is, for example, flat knurling.

[0027] [Separation Pad] The separation pad 48 (see Figures 5, 8, and 9) is made of a material with relatively high frictional resistance, such as silicone rubber. The hardness of the separation pad 48 is higher than the hardness of the second layer 47C of the separation roller 47. Therefore, vibration of the separation pad 48 is suppressed, and abnormal noise is less likely to occur.

[0028] The separation pad 48 is formed, for example, in the shape of a rectangular plate. The separation pad 48 is inclined such that the downstream side in the conveying direction Z is higher than the upstream side. The width dimension of the separation pad 48 perpendicular to the conveying direction Z is longer than that of the separation roller 47. The surface of the separation pad 48 facing the separation roller 47 (the top surface in this embodiment) is flat. One or more grooves 48A are formed on the top surface of the separation pad 48. The grooves 48A are formed in a straight line along the conveying direction Z. The grooves 48A may be inclined with respect to the conveying direction Z, but it is preferable that they are not perpendicular to the conveying direction Z. This is because if the grooves 48A are perpendicular to the conveying direction Z, the leading edge of the sheet G may get caught in the grooves 48A.

[0029] Figures 14 to 16 illustrate variations of the groove 48A. Figure 14 is an example of a separation pad 48 having a groove 48A corresponding to a standard sheet G. In contrast, Figure 15 shows an example in which the width of the groove 48A is widened, and Figure 16 shows an example in which the groove 48A is made deeper and the width of the groove 48A is narrowed. Thus, in this embodiment, multiple types of separation pads 48 with different groove 48A specifications are prepared in advance, and these multiple types of separation pads 48 are interchangeable.

[0030] [Separation pad holder] The separation pad holder 50 (see Figures 5, 11 to 13) comprises a separation pad support portion 51, an arm portion 52, and an engaging portion 56. The separation pad support portion 51 supports the separation pad 48 via a first vibration damping member 61, which will be described later. The arm portion 52 protrudes from both the left and right ends of the separation pad support portion 51 toward the upstream side in the transport direction Z. A hinge hole portion 53 that penetrates in the left-right direction is provided at the upstream end of the arm portion 52 in the transport direction Z. A hinge shaft 55 provided on the transport guide member 39A is inserted into the hinge hole portion 53. The separation pad holder 50 is pivotable about the hinge shaft 55.

[0031] The hinge shaft 55 has a pair of parallel planes 55A (see Figure 18) that are aligned axially. The hinge hole 53 is provided with an opening 54 that penetrates in the transport direction Z. The width W1 of the opening 54 is smaller than the diameter D of the hinge hole 53 and slightly larger than the thickness W2 between the pair of planes 55A. Therefore, by rotating the separation pad holder 50 so that the opening 54 is parallel to the planes 55A, the separation pad holder 50 can be attached to and detached from the hinge shaft 55.

[0032] At both the left and right ends of the downstream end in the transport direction Z of the separation pad support section 51, downwardly bent engaging sections 56 are provided. The engaging sections 56 engage with the gap 39G (see Figure 5) provided in the transport guide member 39A, thereby suppressing changes in the posture of the separation pad holder 50.

[0033] [First vibration damping member, second vibration damping member] The first vibration damping member 61 and the second vibration damping member 62 are made of a material that suppresses vibration, such as urethane. The first vibration damping member 61 is provided between the upper surface of the separation pad support portion 51 and the lower surface of the separation pad 48. The second vibration damping member 62 is provided on the lower surface of the separation pad support portion 51 and is in contact with the transport guide member 39A.

[0034] [Biasing member] The biasing member 57 is, for example, a compression coil spring, which biases the separation pad 48 toward the separation roller 47. The lower surface of the separation pad support portion 51 is provided with a biasing member engagement portion 59 (see Figure 12) into which the upper end of the biasing member 57 engages. The transport guide member 39A is provided with a biasing member support portion 58 that supports the lower end of the biasing member 57 (see Figure 5).

[0035] [Front handling pad, film] The pre-processing pad 65 is located upstream of the separation pad 48 in the conveying direction Z. The pre-processing pad 65 is inclined such that the downstream side in the conveying direction Z is higher than the upstream side, and its inclination angle is greater than that of the separation pad 48. The downstream end of the pre-processing pad 65 in the conveying direction Z is located higher than the upstream end of the separation pad 48 in the conveying direction Z. The pre-processing pad 65 is made of, for example, silicone rubber. The pre-processing pad 65 has the function of reducing the number of sheets G that enter between the separation roller 47 and the separation pad 48.

[0036] A film 66 is stretched between the upstream end of the front handling pad 65 in the conveying direction Z and the conveying guide member 39A. The film 66 is made of, for example, polyethylene terephthalate. The film 66 has the function of preventing the leading edge of the sheet G from getting caught in the gap between the upstream end of the front handling pad 65 in the conveying direction Z and the conveying guide member 39A.

[0037] [Control Unit] The control unit 2 comprises an arithmetic unit and a memory unit (not shown). The arithmetic unit is, for example, a CPU (Central Processing Unit). The memory unit includes a storage medium such as ROM (Read Only Memory), RAM (Random Access Memory), or EEPROM (Electrically Erasable Programmable Read Only Memory). The arithmetic unit performs various processes by reading and executing the control program stored in the memory unit. Note that the control unit 2 may be implemented using only integrated circuits without the use of software.

[0038] [Display operation section] A display and operation unit 19 is provided on the front side of the document scanning device 110. The display and operation unit 19 includes a display panel, a touch panel superimposed on the display surface of the display panel, and a keypad. The control unit 2 displays a screen on the display panel showing the operation menu and status of the printing device 1 and the document scanning device 110, and controls each part of the printing device 1 and the document scanning device 110 in accordance with operations detected by the touch panel and keypad.

[0039] [Operation] The basic operation of the image forming system 100 is as follows: When a user places a sheet G on the upper surface of the contact glass 31 and instructs the document reader 110 to read it, the first carriage 32 moves to the right at a speed V, and in conjunction with this, the second carriage 33 moves to the right at a speed V / 2. During this time, the light source of the first carriage 32 illuminates the sheet G, and the reflected light from the sheet G is reflected by the reflector of the first carriage 32 and the reflector of the second carriage 33, guided to the lens 34A, and formed on the image sensor 34 to be converted into an image signal. The image signal is output to the control unit 2 of the printing device 1 and converted into image data.

[0040] Meanwhile, when a user places a sheet G in the paper feed tray 36 and instructs the document scanning device 110 to scan, the feed roller 46 is driven and the sheets G are fed one by one into the transport path 39. The sheets G are transported along the transport path 39 and discharged into the output tray 37 via the opening 35A. During this time, the light source of the first carriage 32 shines light onto the sheets G through the opening 35A, and the reflected light from the sheets G is reflected by the reflector of the first carriage 32 and the reflector of the second carriage 33, guided to the lens 34A, and formed on the image sensor 34 to be converted into an image signal. The image signal is output to the control unit 2 of the printing device 1 and converted into image data.

[0041] In the printing apparatus 1, the paper feed roller 5 feeds the sheet S from the paper feed cassette 4 to the transport path 10, the registration roller 18, whose rotation has stopped, corrects the orientation of the sheet S, and the registration roller 18 feeds the sheet S to the image-making apparatus 6 at a predetermined timing. In the image-making apparatus 6, the charging device 12 charges the photoreceptor drum 11 to a predetermined potential, the exposure device 13 writes a latent image to the photoreceptor drum 11, the developing device 14 develops the latent image using toner supplied from the toner container 20 to form a toner image, the primary transfer roller 151 transfers the toner image to the intermediate transfer belt 15B, and the secondary transfer roller 152 transfers the toner image to the sheet S.

[0042] Next, the fixing device 7 holds the sheet S and transports it while melting the toner image, thereby fixing the toner image to the sheet S, and the discharge roller 8 discharges the sheet S into the discharge tray 9. In the case of double-sided printing, the sheet S with the toner image fixed to the first side is sent to the transport path 10 via the inversion transport path 10R, thereby transferring the toner image to the second side.

[0043] Next, the feeding operation of the sheet G by the feeding unit 40 will be explained. When feeding out the sheet G (see Figure 6) loaded in the paper feed tray 36, the feeding roller 46 and the separation roller 47 are driven in a clockwise direction in Figure 6. In this case, torque is also applied to the holder 40A in a clockwise direction, causing the holder 40A to swing clockwise around the shaft 47A, and the feeding roller 46 is pressed against the uppermost sheet G among the sheets G loaded in the paper feed tray 36. However, if the sheets G are stuck together due to static electricity or the like, there is a risk of double feeding, where multiple sheets G are fed out while overlapping (see Figure 7).

[0044] In this embodiment, when sheets G are fed in a double feed, first the front feed pad 65 contacts the leading edge of the sheet G. Because the front feed pad 65 is inclined, the double-fed sheet G bends upward, separating the leading edge of the sheet G, and the uppermost sheet G is preferentially fed out. Next, the double-fed sheet G enters between the separation roller 47 and the separation pad 48. Here, if the friction coefficient between the separation roller 47 and the sheet G is μ1, the friction coefficient between the sheet G and the separation pad 48 is μ2, and the friction coefficient between the sheets G themselves is μ3, then if the condition μ3 < μ2 < μ1 is met, only the topmost sheet G is conveyed, and the other sheets G remain on the separation pad 48 due to frictional resistance with the separation pad 48. After that, the topmost sheet G among the sheets G remaining on the separation pad 48 is conveyed, and this operation is repeated until there are no more sheets G on the separation pad 48.

[0045] The sheet transport device according to the embodiment described above includes a feed roller 46 that feeds sheets G from a paper tray 36 in a predetermined transport direction Z, a separation pad 48 provided downstream of the feed roller 46 in the transport direction Z, a separation roller 47 that holds the sheets G fed by the feed roller 46 between itself and the separation pad 48 and transports them in the transport direction Z, and a groove 48A provided on the surface of the separation pad 48 that contacts the sheets G. With this configuration, paper dust trapped between the separation roller 47 and the separation pad 48 falls into the groove 48A, thus suppressing abnormal noises generated by paper dust rubbing against the separation roller 47 and the separation pad 48.

[0046] Furthermore, according to the sheet conveying device of this embodiment, the groove 48A is formed in a straight line along the conveying direction Z. This configuration prevents the leading edge of the sheet G from getting caught in the groove 48A.

[0047] Furthermore, according to the sheet conveying device of this embodiment, multiple types of separation pads 48 with different groove 48A specifications are interchangeable. For example, the frequency of paper dust generation, the friction coefficient with the separation pad 48, the friction coefficient with the separation roller 47, and the friction coefficient between sheets G differ depending on the thickness, material, and surface treatment of the sheet G. Therefore, in order to prevent double feeding, it is desirable to select the friction coefficient of the separation pad 48 and the separation roller 47 according to the sheet G. Also, while a larger ratio of groove 48A to the area of ​​the separation pad 48 makes it easier to collect paper dust, the contact area between the sheet G and the separation pad 48 decreases, thus reducing separation performance. Therefore, it is desirable to select the ratio of groove 48A according to the sheet G. In this embodiment, in order to address the various conditions described above, multiple types of separation pads 48 with different groove 48A specifications are prepared in advance, and it is possible to replace the optimal separation pad 48 according to the thickness, material, and surface treatment of the sheet G. Here, the specifications of the groove 48A include the width of the groove 48A, the depth of the groove 48A, the spacing between multiple grooves 48A, the number of grooves 48A, and the shape of the groove 48A. According to this embodiment, it is possible to achieve both the prevention of double feeding and the suppression of abnormal noise.

[0048] Furthermore, the sheet conveying device according to this embodiment includes a separation pad holder 50 that holds the separation pad 48, and a conveying guide member 39A that guides the conveyance of the sheet G and detachably supports the separation pad holder 50. With this configuration, the separation pad 48 can be easily replaced.

[0049] The above embodiment may be modified as follows.

[0050] In the above embodiment, an example was shown in which the groove 48A is formed in a straight line along the conveying direction Z. However, the groove 48A may be formed in a straight line inclined at a predetermined angle with respect to the conveying direction Z. Compared to the case where the groove 48A is formed along the conveying direction Z, the probability of paper dust falling into the groove 48A can be improved. Furthermore, the shape of the groove 48A does not have to be straight; for example, it may be curved or meandering. Compared to the case where the groove 48A is straight, the probability of paper dust falling into the groove 48A can be improved.

[0051] The configuration of the above embodiment, including the separation roller 47 and separation pad 48, may also be applied to the paper feed cassette 4.

[0052] In the above embodiment, an example was shown where the document reading device 110 is a flatbed scanner; however, the document reading device 110 may also be a contact image scanner.

[0053] In the above embodiment, an example was shown where the printing device 1 is a color printer, but the printing device 1 may also be a monochrome printer or an inkjet printer. [Explanation of Symbols]

[0054] 36 Paper feed tray 39A Conveyor guide member 46. ​​Dispatch roller 47 Separation roller 48 Separation Pads 48A Groove 50 Separation Pad Holder 120 Document transport device (sheet transport device) G Seat Z-direction of transport

Claims

1. A feed roller that feeds sheets from the paper tray in a predetermined transport direction, A separation pad provided downstream of the feed roller in the conveying direction, A separation roller that holds the sheet dispensed by the aforementioned dispensing roller between itself and the separation pad and conveys it in the conveying direction, A sheet conveying device characterized by comprising a groove provided on the surface of the separation pad that comes into contact with the sheet.

2. The sheet conveying device according to claim 1, characterized in that the groove is formed in a straight line along the conveying direction.

3. The sheet conveying device according to claim 1 or 2, characterized in that multiple types of separation pads with different groove specifications are interchangeable.

4. A separation pad holder that holds the separation pad, The sheet conveying device according to claim 3, further comprising a conveying guide member that guides the conveyance of the sheet and detachably supports the separation pad holder.

Images