Recording material conveying device and image reading device

Abstract

To achieve higher image reading accuracy of a recording material during carrying travel than when the displacement of a recording material in such a direction as to cross the carrying direction is not suppressed.SOLUTION: A recording material carrier device includes: a first carrier roll pair 4 for carrying paper P to be carried; and a first carrier unit 3A having a carrier belt 31 for receiving paper P from the first carrier roll pair 4 and carrying paper P toward a first reading unit 2A for reading an image on the paper P, in which frictional coefficients are different from each other between the carrier direction (paper face right direction) which is a carrier direction in the carrier surface of the carrier belt 31 and the crossing direction (paper surface vertical direction) which is the direction crossing the carrier direction, and a frictional coefficient in the crossing direction is smaller than the frictional coefficient in the carrying direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a recording material transport device and an image reading device. [Background technology]

[0002] For example, Patent Document 1 discloses a sheet conveying device that conveys a sheet by using an endless conveying belt. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-82505 A Summary of the Invention [Problem to be solved by the invention]

[0004] Here, the recording material to be conveyed is conveyed by being transferred from the conveying means on the upstream side to the conveying means on the downstream side. For example, if the upstream conveying means is a roller conveying means and the downstream conveying means is a belt conveying means, the conveying direction of the conveying belt may change. The running stability of the recording material during transportation is impaired. For this reason, For example, when reading an image on a recording material while it is being transported, it becomes difficult to improve the accuracy of image reading. The object of the present invention is to Conveyor belt Suppresses the displacement of the recording material in the direction crossing the transport direction do The object of the present invention is to improve the accuracy of image reading of the recording material during transport as compared with the conventional case. [Means for solving the problem]

[0005] The invention described in claim 1 includes a first conveying means for conveying a recording material to be conveyed, and a second conveying means having a conveying belt that receives the recording material from the first conveying means and conveys the recording material toward a reading unit that reads an image on the recording material, the conveying belt being configured such that a friction coefficient is different between a conveying direction that is a direction of conveyance and a cross direction that is a direction crossing the conveying direction on a conveying surface of the conveying belt, and the friction coefficient in the cross direction is smaller than the friction coefficient in the conveying direction.、 The conveyor belt of the second conveyor means is formed of a woven fabric woven with warp and weft threads. 、 The woven fabric forms the conveying surface of the conveyor belt by having the weft threads protruding from the surface of the warp threads, and the cross direction of the conveyor belt is a weft thread direction in which the weft threads extend. 、 This is a recording material transport device. Claim 2 The invention described in a second conveying means having a first conveying means for conveying a recording material to be conveyed, and a conveying belt for receiving the recording material from the first conveying means and conveying the recording material toward a reading unit for reading an image on the recording material, the second conveying means being configured so that a friction coefficient is different between a conveying direction, which is a direction of conveyance, and a cross direction, which is a direction crossing the conveying direction, on a conveying surface of the conveying belt, and the friction coefficient in the cross direction is smaller than the friction coefficient in the conveying direction, the conveying belt of the second conveying means being formed of a fabric woven with warp threads and weft threads, the fabric forming the conveying surface of the conveying belt by the warp threads protruding above the weft threads, and the cross direction of the conveying belt being the warp thread direction in which the warp threads extend, A recording material conveying device 。 Claim 3 The invention described in claim 1 is characterized in that the first conveying means has a larger frictional force than the conveying belt of the second conveying means. or 2 2 is a recording material conveying device according to the first embodiment. Claim 4 The invention described in is characterized in that the first transport means is composed of a transport roll that is driven and a driven roll that faces the transport roll and is driven by the transport roll. 3 2 is a recording material conveying device according to the first embodiment. Claim 5 The invention described in a second conveying means having a conveying belt which receives the recording material from the first conveying means and conveys the recording material towards a reading section which reads an image on the recording material, the second conveying means being configured so that a friction coefficient is different between a conveying direction which is a direction of conveyance of the recording material and a cross direction which is a direction crossing the conveying direction on a conveying surface of the conveying belt, the friction coefficient in the cross direction being smaller than the friction coefficient in the conveying direction; and a third conveying means which is located downstream of the second conveying means in the conveying direction and has a friction force larger than that of the second conveying means. the third conveying means is located away from the first conveying means so that a state in which the recording material is conveyed by both the third conveying means and the first conveying means is formed. 、 A recording material conveying device 。 Claim 6 The invention described in The recording material conveying device according to claim 1, 2 or 5 is included. It is an image reading device. Effect of the Invention

[0006] According to claim 1 、 The manufacturing cost of the transport belt can be reduced as compared to a case in which the transport surface is formed by warp threads extending in the transport direction. Claim 2 According to this, stretching of the conveyor belt in the cross direction can be suppressed as compared with a case in which the conveying surface is formed by weft threads extending in the conveying direction. Claim 3According to this, compared to a case where the frictional force of the first conveying means is smaller than that of the conveying belt of the second conveying means, the posture of the recording material during conveyance can be controlled by the first conveying means. Claim 4 According to this, the frictional force can be increased with a simple configuration, compared to a case in which the first transport means is not configured by a driven transport roll and a driven roll that faces the transport roll and follows the transport roll. Claim 5 According to the above, it is possible to suppress deviation of the conveyed recording material in the cross direction, compared to a case where the recording material is not conveyed by both the third conveying means located downstream of the second conveying means in the conveying direction and the first conveying means. 。 Claim 6 According to The invention has the following advantages. That is, in an image reading device including the recording material conveying device according to claim 1, Transport direction The conveying surface is formed by the warp yarns extending in the direction Compared to the case of Reduce belt manufacturing costs It is possible. In addition, in an image reading device including the recording material conveying device described in claim 2, stretching of the conveying belt in the cross direction can be suppressed compared to a case where the conveying surface is formed by weft threads extending in the conveying direction. Furthermore, in an image reading device including the recording material conveying device described in claim 5, deviation in the cross direction of the conveyed recording material can be suppressed compared to a case where the recording material is not conveyed by both the third conveying means located downstream of the second conveying means in the conveying direction and the first conveying means. [Brief description of the drawings]

[0007] [Figure 1] 1 is a schematic configuration diagram showing an image inspection device to which the present embodiment is applied; [Diagram 2] FIG. 2 is an explanatory diagram of the configuration of a second conveying unit, and is an enlarged view of a portion II in FIG. [Diagram 3] FIG. 3 is a view of FIG. 2 as seen from direction III. [Figure 4] 1 is a diagram showing a schematic configuration of a conveyor belt to which the present embodiment is applied; [Diagram 5] 1A and 1B are diagrams for explaining the case where a conveyor belt is formed from a woven fabric, in which (a) is a schematic cross-sectional view of a conveyor belt when a woven fabric of a first weaving pattern is used, (b) is an enlarged view showing the weave of the warp and weft threads in the case of (a), (c) is a schematic cross-sectional view of a conveyor belt when a woven fabric of a second weaving pattern is used, and (d) is an enlarged view showing the weave of the warp and weft threads in the case of (c). [Figure 6] 1A to 1C are diagrams illustrating a state in which a sheet is transported in a section from a first transport roll pair to a second transport roll pair, and are shown in chronological order from (a) to (c). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. (Overall configuration of image inspection device 1) FIG. 1 is a schematic diagram showing the configuration of an image inspection device 1 to which this embodiment is applied. The image inspection device 1 is an example of an image reading device, and is used to read an image formed on a sheet P by an image forming device (not shown) and inspect this image.

[0009] The image inspection device 1 is provided with a transport path R along which paper P, which is an example of a recording material discharged from an image forming device, is transported. In this example, the paper P is transported along the transport path R from the left side to the right side in FIG. 1 by a first transport unit 3A and a second transport unit 3B, which will be described later. In the following description, the direction in which the paper P is transported along the transport path R (the direction from the left side to the right side in FIG. 1) may be referred to as the transport direction of the paper P. Also, the direction intersecting the transport direction of the paper P (the depth direction in FIG. 1) may be referred to as the width direction of the paper P. The image inspection device 1 has a first reading unit 2A that reads an image formed on one side (the lower side of the paper P shown in FIG. 1) of the paper P transported on the transport path R, and a second reading unit 2B that reads an image formed on the other side (the upper side of the paper P shown in FIG. 1) of the paper P transported on the transport path R. In the image inspection device 1 of this embodiment, the first reading unit 2A and the second reading unit 2B are arranged side by side in the transport direction of the paper P on the transport path R. Also, in this embodiment, the first reading unit 2A is an example of a reading section, and the second reading unit 2B is an example of a reading section.

[0010] The first reading unit 2A and the second reading unit 2B have the same structure, except for the orientation with respect to the paper P transported along the transport path R. The first reading unit 2A and the second reading unit 2B are configured by a so-called reduction optical system. Specifically, the first reading unit 2A and the second reading unit 2B have a light source 21 that irradiates light onto the paper P, a mirror 22 that reflects the reflected light from the paper P, an imaging lens 23 that optically reduces the light from the mirror 22 to form an image, and an image sensor 24 that converts the optical image formed by the imaging lens 23 into an electrical signal. In the following description, the area where the light is irradiated by the light source 21 and the light is reflected from the paper P (i.e., the area where the image formed on the paper P is read) may be referred to as a reading area 20 (see FIG. 2). In addition, the first reading unit 2A and the second reading unit 2B are not particularly limited as long as they are capable of reading the image formed on the paper P, and in addition to the reduction optical system described above, a so-called contact optical system using, for example, a CIS (Contact Image Sensor) may be adopted.

[0011] The image inspection device 1 also has a first transport unit 3A disposed opposite the reading area 20 of the first reading unit 2A and transporting the paper P toward the reading area 20, and a second transport unit 3B disposed opposite the reading area 20 of the second reading unit 2B and transporting the paper P toward the reading area 20. In the first reading unit 2A and the second reading unit 2B, the paper P does not stop in the reading area 20, but reads the image on the paper P as it passes through the reading area 20. The configurations of the first transport unit 3A and the second transport unit 3B will be described in detail later.

[0012] Furthermore, the image inspection device 1 has a first transport roll pair 4 that transports the paper discharged from the image forming device toward the first transport unit 3A, a second transport roll pair 5 that transports the paper P transported through the first transport unit 3A toward the second transport unit 3B, and a third transport roll pair 6 that transports the paper P transported through the second transport unit 3B further downstream. In this embodiment, the first transport roll pair 4 is an example of a first transport means, the first transport unit 3A is an example of a second transport means, and the second transport roll pair 5 is an example of a third transport means. Also, the second transport roll pair 5 is an example of a first transport means, the second transport unit 3B is an example of a second transport means, and the third transport roll pair 6 is an example of a third transport means. In the present embodiment, the first transport roll pair 4, the first transport unit 3A, and the second transport roll pair 5 are an example of a recording material transport device, and the second transport roll pair 5, the second transport unit 3B, and the third transport roll pair 6 are an example of a recording material transport device.

[0013] The first conveying roll pair 4 is rotated in a predetermined direction (counterclockwise in Figure 1) by a motor not shown, and has a conveying roll 41 that conveys the paper P, and an opposing roll 42 that faces the conveying roll 41 across the paper P and rotates in conjunction with the conveying roll 41. Similarly, the second conveying roll pair 5 is rotated in a predetermined direction (counterclockwise in Figure 1) by a motor not shown, and has a conveying roll 51 that conveys the paper P, and an opposing roll 52 that faces the conveying roll 51 across the paper P and rotates in conjunction with the conveying roll 51. Furthermore, the third conveying roll pair 6 is rotated in a predetermined direction (counterclockwise in Figure 1) by a motor not shown, and has a conveying roll 61 that conveys the paper P, and an opposing roll 62 that faces the conveying roll 61 across the paper P and rotates in conjunction with the conveying roll 61. In this embodiment, the transport roll 41 of the first transport roll pair 4 is an example of a transport roll, and the opposing roll 42 is an example of a driven roll. Also, the transport roll 51 of the second transport roll pair 5 is an example of a transport roll, and the opposing roll 52 is an example of a driven roll.

[0014] Furthermore, the image inspection device 1 has a control unit 7 that controls each part of the image inspection device 1. The control unit 7 has a central processing unit (CPU), a read only memory (ROM), a random access memory (RAM), etc. (not shown). The ROM stores a basic program (operation system) executed by the CPU, various settings, etc. The CPU uses the RAM as a working area and executes application programs read from the ROM or a storage unit (not shown) such as a semiconductor memory or a hard disk drive (HDD). The functions of the control unit 7 described below are realized by the CPU executing the programs.

[0015] Image data from the image forming apparatus is input to the control unit 7. Furthermore, read data acquired by the first reading unit 2A and the second reading unit 2B is input to the control unit 7. Then, the control unit 7 divides each of the image data and the read data into a plurality of predetermined regions, and performs a pattern matching process for each region, thereby inspecting whether or not there is a defect in the image formed on the paper P. Each of the first transport roll pair 4, the second transport roll pair 5 and the third transport roll pair 6 is equipped with an encoder (not shown) for creating a reference signal for paper transport and image reading, and the paper P transported between the first transport roll pair 4 and the third transport roll pair 6 is always transported by either one or adjacent two of the first transport roll pair 4, the second transport roll pair 5 and the third transport roll pair 6.

[0016] (Configuration of the first transport unit 3A and the second transport unit 3B) Next, the configurations of the first transport unit 3A and the second transport unit 3B will be described. Fig. 2 is a diagram for explaining the configuration of the first transport unit 3A, and is an enlarged view of part II in Fig. 1. Fig. 3 is a view seen from the direction III in Fig. 2. The light source 21 is omitted in Fig. 3. The first transport unit 3A and the second transport unit 3B have the same structure, except for the orientation with respect to the paper P transported along the transport path R. Here, the first transport unit 3A will be described as an example. In the following description, the same components of the second transport unit 3B as those of the first transport unit 3A may be described using the same reference numerals as those used for the first transport unit 3A.

[0017] The first transport unit 3A includes an endless transport belt 31 that transports the paper P while adsorbing it, a drive roll 32 that contacts the inner peripheral surface 31B of the transport belt 31 and rotates by a motor (not shown) to move the transport belt 31 around, and a driven roll 33 that is disposed upstream of the drive roll 32 in the transport direction of the paper P, contacts the inner peripheral surface 31B of the transport belt 31 to support the transport belt 31 and rotates following the transport belt 31. The first transport unit 3A also includes support rolls 34 and 35 that contact the inner peripheral surface 31B of the transport belt 31 and support the transport belt 31 together with the drive roll 32 and the driven roll 33. The first transport unit 3A also includes a fan 36 that sucks air and generates an airflow from the outer periphery to the inner periphery of the transport belt 31, and a support member 37 that houses the fan 36 and contacts the inner peripheral surface 31B of the transport belt 31 to support the transport belt 31.

[0018] (Description of conveyor belt 31) The conveyor belts 31 of the first conveyor unit 3A and the second conveyor unit 3B will be described. FIG. 4 is a diagram showing a schematic configuration of a conveyor belt 31 to which the present embodiment is applied. The conveyor belt 31 is made of a sheet-like material having air permeability that allows airflow to pass between the outer periphery and the inner periphery of the conveyor belt 31. In this example, as shown in FIG. 4, the conveyor belt 31 has a mesh-like shape having air permeability. More specifically, the conveyor belt 31 is made of a woven fabric made of fibers made of resin such as polyamide. More specifically, the conveyor belt 31 is a woven fabric made of warp threads 71 ​​and weft threads 72 (see FIG. 5). This makes it easy to meet the conditions required of the conveyor belt 31. In addition, the conveyor belt 31 is not limited to a mesh-like material as long as it has air permeability. For example, the conveyor belt 31 may be a sheet-like member other than a woven material, such as a nonwoven fabric or a rubber belt, provided with a plurality of through holes that allow the outer periphery and the inner periphery to communicate with each other. Hereinafter, the direction in which the paper P is transported by the transport belt 31 will be referred to as the transport direction of the transport belt 31, and the direction intersecting the transport direction will be referred to as the intersecting direction of the transport belt 31.

[0019] In the first transport unit 3A and the second transport unit 3B having the above-mentioned suction transport function and image reading function, the friction coefficient of the surface of the transport belt 31 may be increased in order to improve the efficiency of transporting the paper P. However, for example, in the case of the first transport unit 3A, the first transport roll pair 4 is located on the upstream side of the transport belt 31, and the second transport roll pair 5 is located on the downstream side. If the transport direction of the transport roll pairs 4, 5 and the transport direction of the transport belt 31 are not the same and an angular misalignment occurs between them, the amount of misalignment in the intersecting direction increases toward the downstream side of the transport belt 31. For this reason, there is a risk that the paper P will move in the intersecting direction due to the transport belt 31 while being read by the image reading function. In such a case, it becomes difficult to read with high accuracy. On the other hand, when comparing the misalignment in the conveying direction caused by the conveying roll pairs 4, 5 and the conveying belt 31 during conveyance, the amount of misalignment is smaller for the conveying roll pairs 4, 5 than for the conveying belt 31 due to their structures.

[0020] Therefore, in this embodiment, in order to address the difficulty of high-precision reading caused by changes in the conveying direction by the conveying belt 31, the friction coefficients on the conveying surface 311 (see Figure 5), which is the surface along which the paper P is conveyed by the conveying belt 31, are made different in the conveying direction and the intersecting direction, and the friction coefficient of the conveying belt 31 in the intersecting direction is configured to be smaller than the friction coefficient in the conveying direction. That is, by making the friction coefficient in the cross direction on the conveying surface 311 of the conveying belt 31 smaller than that in the conveying direction, the friction force in the cross direction that the conveying belt 31 acts on the paper P is reduced, and the paper P being conveyed by the first conveying roll pair 4 or the second conveying roll pair 5 and the conveying belt 31 is allowed to be displaced in the cross direction relative to the conveying belt 31. This prevents the paper P from moving in the cross direction of the conveying belt 31 even if the conveying direction of the conveying belt 31 differs from the conveying direction of the conveying roll pair 4 or the conveying roll pair 5. figure This enables highly accurate readings. The specific configuration of the conveyor belt 31 will be described below.

[0021] FIG. 5 is a diagram illustrating the case where the conveyor belt 31 is formed from a woven fabric, where (a) is a schematic cross-sectional view of the conveyor belt 31 when a woven fabric of a first weaving pattern is used, (b) is an enlarged view showing the weave of the warp threads 71 ​​and weft threads 72 in the case of (a), (c) is a schematic cross-sectional view of the conveyor belt 31 when a woven fabric of a second weaving pattern is used, and (d) is an enlarged view showing the weave of the warp threads 71 ​​and weft threads 72 in the case of (c). As shown in Figures 5(a) to (d), a woven fabric is a fabric made by aligning warp threads 71 ​​straight and stretching them tightly, and weaving weft threads 72 between them, so that the warp threads 71 ​​and weft threads 72 cross each other. The warp threads 71 ​​refer to threads that are stretched vertically when weaving a woven fabric, and are also referred to as warp threads or vertical threads. The weft threads 72 refer to threads that are inserted horizontally when weaving a woven fabric, and are also referred to as weft threads or horizontal threads. In the woven fabric, the warp threads 71 ​​are less stretchable than the weft threads 72, which allows the warp threads 71 ​​and the weft threads 72 to be distinguished from each other.

[0022] The fabrics shown in FIGS. 5(a) to (d) are all plain weave fabrics in which one warp thread 71 crosses one weft thread 72, and the appearance of the crepe texture is almost similar, with the texture running in the direction of the warp thread 71. More specifically, the first weaving pattern shown in (a) and (b) is a crepe made of silk with a clearly embossed surface, in which the warp threads 71 ​​have a larger crimp (fiber shrinkage) than the weft threads 72, and as shown in (a) and (b), the warp threads 71 ​​are more prominent on the surface than the weft threads 72. Therefore, when the conveyor belt 31 is formed from a fabric having the first weaving pattern, the conveyor surface 311 of the conveyor belt 31 can be formed by the warp threads 71 ​​that are more prominent on the surface. In this case, the coefficient of friction is higher in the direction in which the weft threads 72 extend than in the direction in which the warp threads 71 ​​extend, i.e., in the direction intersecting the direction in which the warp threads 71 ​​extend. Therefore, in the conveyor belt 31 according to the first aspect, the direction in which the weft threads 72 extend is the conveying direction of the conveyor belt 31, and the direction in which the warp threads 71 ​​extend is the cross direction of the conveyor belt 31, thereby realizing the above-mentioned "configuration in which the friction coefficient in the cross direction on the conveyor surface 311 is smaller than the friction coefficient in the conveying direction."

[0023] 5(c) and (d) is a crepe made of polyester, in which the weft 72 has a larger crimp (fiber shrinkage) than the warp 71, and unlike the first weaving mode, the weft 72 protrudes from the surface of the warp 71 as shown in FIG. 5(c) and (d). Therefore, when the conveyor belt 31 is formed of a fabric having the second weaving mode, the conveyor surface 311 of the conveyor belt 31 can be formed by the weft 72 protruding from the surface. In this case, the coefficient of friction is higher in the direction in which the warp 71 extends than in the direction in which the weft 72 extends, i.e., in the direction intersecting the direction in which the weft 72 extends. Therefore, in the conveyor belt 31 according to the second aspect, the direction in which the warp threads 71 ​​extend is the conveying direction of the conveyor belt 31, and the direction in which the weft threads 72 extend is the intersecting direction of the conveyor belt 31, thereby realizing the above-mentioned "configuration in which the friction coefficient in the intersecting direction on the conveying surface 311 is smaller than the friction coefficient in the conveying direction."

[0024] In this way, when the conveyor belt 31 is formed from the first type of woven fabric and when it is formed from the second type of woven fabric, the extension directions of the warp threads 71 ​​and the weft threads 72 are opposite to each other, thereby reducing the friction coefficient in the cross direction on the conveying surface 311 of the conveyor belt 31.

[0025] When the first weaving pattern is used, the conveying direction of the conveyor belt 31 is set to the direction in which the warp threads 71, which have a property of being less stretchable than the weft threads 72, extend. This makes it possible to suppress the stretching of the conveyor belt 31 in the conveying direction. In addition, by making the warp direction, in which the warp threads 71 ​​extend, the conveying direction the same as the warp direction, makes it possible to reduce the manufacturing cost of the conveyor belt 31. Furthermore, when the second weaving mode is used, the conveying surface 311 is formed by the weft threads 72, and therefore the crossing direction of the conveying belt 31 is the warp direction. That is, the crossing direction of the conveying belt 31 is the warp direction in which the warp threads 71, which have a property of being less stretchable than the weft threads 72, extend. Therefore, the stretching of the conveying belt 31 in the crossing direction can be suppressed.

[0026] Here, the first and second weaving patterns of the fabric used for the conveyor belt 31 are used to make the friction coefficients different in the conveying direction and the cross direction of the conveyor belt 31, but this is not limited to the above. For example, it is possible to realize different friction coefficients by using a fabric woven so that the warp threads 71 ​​and weft threads 72 have different thicknesses.

[0027] (Other configurations of the first transport unit and the second transport unit) 2, the driving roll 32 has a shaft 321 extending in the width direction and an elastic layer 322 formed on the outer circumferential surface of the shaft 321. The driving roll 32 rotates when the shaft 321 is rotated in a predetermined direction (clockwise in this example) by a motor (not shown). In this embodiment, the conveyor belt 31 is driven by the driving roll 32 that contacts the inner peripheral surface 31B of the conveyor belt 31 on the most downstream side in the conveying direction. In addition, the driving roll 32 contacts the inner peripheral surface 31B of the conveyor belt 31 downstream in the conveying direction of the driven roll 33 and the support rolls 34 and 35 that support the conveyor belt 31 together with the driving roll 32. This prevents the conveyor belt 31 from sagging around the reading area 20 located between the driven roll 33 and the driving roll 32.

[0028] The fan 36 draws in air to generate an airflow from the outer periphery to the inner periphery of the conveyor belt 31. The structure of the fan 36 is not particularly limited as long as it can draw in air, and for example, a sirocco fan, a propeller fan, or the like can be used. The fan 36 is disposed on the inner circumference of the conveyor belt 31 so as to face the reading area 20 across the conveyor belt 31. In the first conveying unit 3A of the present embodiment, the fan 36 generates an airflow from the outer circumference to the inner circumference of the conveyor belt 31, so that the paper P conveyed onto the conveyor belt 31 is attracted to the outer circumferential surface 31A of the conveyor belt 31. In this manner, the fan 36 is an example of an airflow generating section that generates an airflow from the outer circumference to the inner circumference of the conveyor belt 31, and brings the paper P into close contact with the outer circumferential surface 31A of the conveyor belt 31 that faces the reading area 20. The outer circumferential surface 31A of the conveyor belt 31 faces the reading area 20 via a gap.

[0029] The support member 37 has an elongated shape extending along the width direction intersecting with the conveying direction of the paper P. The support member 37 has a guide surface 371 that contacts the inner circumferential surface 31B of the conveyor belt 31 and guides the movement of the conveyor belt 31. The guide surface 371 is configured as a flat surface extending along the conveying direction of the paper P. The guide surface 371 is provided so as to face the first reading unit 2A (see FIG. 1) across the conveyor belt 31. In addition, the guide surface 371 is provided so as to face the first reading unit 2A at a predetermined distance. The distance between the guide surface 371 and the first reading unit 2A is determined according to the irradiation distance of light from the light source 21 of the first reading unit 2A, the focal length of the imaging lens 23, and the like. Furthermore, the guide surface 371 has a plurality of through holes formed therein, penetrating from the side in contact with the conveyor belt 31 to the side facing the fan 36. This allows air to pass through the conveyor belt 31 and the guide surface 371 and be sucked into the fan 36 when the fan 36 rotates.

[0030] In the first transport unit 3A of this embodiment, the height of the guide surface 371 of the support member 37 is equal to the height of the top of the drive roll 32 and the driven roll 33. In addition, in the first transport unit 3A, the transport belt 31 moves in a circular motion while maintaining a horizontal state with respect to the transport direction from the driven roll 33 through the guide surface 371 of the support member 37 to the drive roll 32. This makes it difficult for the paper P to float from the outer peripheral surface 31A of the transport belt 31, and suppresses fluctuations in the distance between the first reading unit 2A and one side of the paper P.

[0031] FIG. 6 is a diagram for explaining a state in which the paper P is transported in the section from the first transport roll pair 4 to the second transport roll pair 5, and is shown in chronological order from (a) to (c). As shown in Fig. 6(a), the leading edge of the paper P transported by the first transport roll pair 4 is on the transport surface of the transport belt 31 of the first transport unit 3A. An encoder (not shown) of the first transport roll pair 4 creates a reference signal for paper transport and image reading.

[0032] When the paper P is transported in the transport direction, as shown in Fig. 6(b), the trailing end side is transported by the first transport roll pair 4, and the leading end side is transported by the second transport roll pair 5. A reference signal for paper transport and image reading is generated by an encoder (not shown) of the second transport roll pair 5. The frictional forces of the first transport roll pair 4 and the second transport roll pair 5 located downstream thereof are not the same, and the frictional force of the second transport roll pair 5 is greater than the frictional force of the first transport roll pair 4.

[0033] In this manner, in the present embodiment, the second transport roll pair 5 located downstream of the first transport unit 3A in the transport direction has a larger frictional force than the transport belt 31 of the first transport unit 3A, and the second transport roll pair 5 is located away from the first transport roll pair 4 so that a state is created in which the paper P is transported by both the second transport roll pair 5 and the first transport roll pair 4. This makes it possible to suppress deviation in the cross direction of the paper P transported by the first transport unit 3A.

[0034] As the paper P is further transported, as shown in FIG. 6(c), the trailing end of the paper P is transported by the second transport roll pair 5 and handed over to the subsequent second transport unit 3B. In the second transport unit 3B, too, it is preferable that the third transport roll pair 6 located downstream of the second transport unit 3B in the transport direction has a larger frictional force than the transport belt 31 of the second transport unit 3B, and that the third transport roll pair 6 is located away from the second transport roll pair 5 so that a state is created in which the paper P is transported by both the third transport roll pair 6 and the second transport roll pair 5. This makes it possible to suppress deviation in the cross direction of the paper P transported by the second transport unit 3B.

[0035] (Operation of image inspection device 1) Next, the operation of the image inspection device 1 of this embodiment will be described. When inspecting an image formed on a paper P in the image inspection device 1, the first transport roll pair 4, the second transport roll pair 5, the third transport roll pair 6, the first transport unit 3A, and the second transport unit 3B are driven. Specifically, power is supplied to a motor (not shown) that drives the transport roll 41 of the first transport roll pair 4, the transport roll 51 of the second transport roll pair 5, and the transport roll 61 of the third transport roll pair 6. As a result, the transport roll 41 of the first transport roll pair 4, the transport roll 51 of the second transport roll pair 5, and the transport roll 61 of the third transport roll pair 6 rotate in a predetermined direction.

[0036] In the first transport unit 3A and the second transport unit 3B, power is supplied to a motor (not shown) that drives the drive roll 32, causing the drive roll 32 to rotate in a predetermined direction. This causes the transport belt 31 to move in a circular motion in the first transport unit 3A and the second transport unit 3B. Furthermore, in the first transport unit 3A and the second transport unit 3B, power is supplied to the fan 36, causing the fan 36 to rotate and suck in air.

[0037] Next, a sheet of paper P on which an image has been formed by an image forming device (not shown) or the like is fed into the image inspection device 1. The sheet of paper P fed into the image inspection device 1 is fed downstream in the feed direction by the first feed roll pair 4. Then, when the leading edge of the sheet of paper P reaches the feed belt 31 of the first feed unit 3A, the sheet of paper P is adsorbed to the outer peripheral surface 31A of the feed belt 31 by the airflow generated by the fan 36. Then, while being adsorbed to the outer peripheral surface 31A of the feed belt 31, the sheet of paper P is further fed downstream in the feed direction as the feed belt 31 rotates.

[0038] Then, when the paper P reaches the reading area 20 of the first reading unit 2A, the first reading unit 2A reads the image formed on one side of the paper P facing the first reading unit 2A (the lower side in FIG. 1). Specifically, light is irradiated onto the paper P by the light source 21 of the first reading unit 2A, and the reflected light is input to the image sensor 24 via the mirror 22 and the imaging lens 23. The control unit 7 performs a pattern matching process on the read data input to and acquired by the image sensor 24 and the image data input from the image forming device, and it is inspected whether or not there is a defect in the image formed on one side of the paper P.

[0039] Here, in the first transport unit 3A of the present embodiment, when the paper P passes through the reading area 20 of the first reading unit 2A, it is adsorbed to the outer circumferential surface 31A of the conveyor belt 31 by the airflow generated by the fan 36. This makes it difficult for the paper P to float from the outer circumferential surface 31A of the conveyor belt 31, and the variation in the distance between the first reading unit 2A and one side of the paper P is suppressed compared to when the paper P is not adsorbed to the outer circumferential surface 31A of the conveyor belt 31. As a result, the deterioration of the reading accuracy of the image by the first reading unit 2A is suppressed.

[0040] Next, the paper P that has passed through the first transport unit 3A is transported further downstream in the transport direction by the second transport roll pair 5. Then, when the leading edge of the paper P reaches the transport belt 31 of the second transport unit 3B, the paper P is attracted to the outer peripheral surface 31A of the transport belt 31 by the airflow generated by the fan 36. Then, while being attracted to the outer peripheral surface 31A of the transport belt 31, the paper P is transported further downstream as the transport belt 31 rotates.

[0041] Then, when the paper P reaches the reading area 20 of the second reading unit 2B, the second reading unit 2B reads the image formed on the other side of the paper P facing the second reading unit 2B (the upper side in FIG. 1). Specifically, light is irradiated onto the paper P by the light source 21 of the second reading unit 2B, and the reflected light is input to the image sensor 24 via the mirror 22 and the imaging lens 23. The control unit 7 performs a pattern matching process on the read data input to and acquired by the image sensor 24 and the image data input from the image forming device, and it is checked whether or not there is a defect in the image formed on the other side of the paper P.

[0042] Here, in the second transport unit 3B of the present embodiment, similarly to the first transport unit 3A, when the paper P passes through the reading area 20 of the second reading unit 2B, it is adsorbed to the outer circumferential surface 31A of the conveyor belt 31 by the airflow generated by the fan 36. This makes it difficult for the paper P to float from the outer circumferential surface 31A of the conveyor belt 31, and the variation in the distance between the second reading unit 2B and the other side of the paper P is suppressed compared to when the paper P is not adsorbed to the outer circumferential surface 31A of the conveyor belt 31. As a result, the deterioration of the reading accuracy of the image by the second reading unit 2B is suppressed.

[0043] Thereafter, the paper P that has passed through the second transport unit 3B is further transported downstream in the transport direction by the third transport roll pair 6, and is discharged from the image inspection device 1. With the above, a series of processes in the image inspection device 1 is completed.

[0044] (Functions of the First Conveyor Unit 3A and the Second Conveyor Unit 3B) However, in the image inspection device 1 that operates as described above, the direction in which the conveying belt 31 of the first conveying unit 3A or the second conveying unit 3B conveys the paper P may be shifted relative to the direction in which the first conveying roll pair 4 or the second conveying roll pair 5 that conveys the paper P to the conveying belt 31 conveys the paper P. For example, if the direction in which the conveyor belt 31 of the second conveying unit 3B conveys the paper P is misaligned with the direction in which the second conveyor roll pair 5 conveys the paper P, the paper P that enters the conveyor belt 31 from the second conveyor roll pair 5 may be conveyed while shifting in the width direction and meandering, as shown by the dashed line in Fig. 3. As a result, the position of the paper P relative to the reading area 20 may be shifted in the width direction, reducing the reading accuracy of the paper P by the second reading unit 2B, and making it impossible to accurately inspect the image. Although not shown in the drawings, a similar problem may occur between the first transport unit 3A and the first transport roll pair 4.

[0045] In contrast, in the first transport unit 3A of the present embodiment, as described above, the friction coefficient in the cross direction on the transport surface 311 of the transport belt 31 (see FIG. 5) is smaller than the friction coefficient in the transport direction. This allows for displacement of the paper P on the transport surface 311 in the cross direction compared to, for example, a case where the friction coefficient in the cross direction is the same as or larger than the friction coefficient in the transport direction. In other words, because the friction coefficient in the cross direction of the transport belt 31 is smaller than the friction coefficient in the transport direction, the paper P is more likely to slide in the cross direction on the transport surface 311 of the transport belt 31. As a result, when the direction in which the first transport roll pair 4 transports the paper P and the direction in which the transport belt 31 transports the paper P is misaligned, the paper P that has entered the transport belt 31 from the first transport roll pair 4 is transported in the direction in which the first transport roll pair 4 transports the paper P on the transport surface 311 of the transport belt 31. This prevents the paper P from being transported in a direction that is misaligned with respect to the reading area 20. figure Therefore, the deterioration of the reading accuracy by the first reading unit 2A is suppressed.

[0046] Although not shown in the drawings, in the second transport unit 3B as well, the friction coefficient in the cross direction on the transport surface 311 of the transport belt 31 is smaller than the friction coefficient in the transport direction, so that the paper P that enters the transport belt 31 from the second transport roll pair 5 is transported in the direction in which the second transport roll pair 5 transports the paper P on the transport surface 311 of the transport belt 31. This prevents the paper P from being misaligned in the cross direction relative to the reading area 20. figure Therefore, the deterioration of the reading accuracy by the second reading unit 2B is suppressed.

[0047] The conveyor belt 31 in this embodiment is formed of a fabric woven with warp threads 71 ​​and weft threads 72, but is not limited to this. The conveyor belt 31 may be formed of a nonwoven fabric or a mesh rubber belt and provided with wires extending in the intersecting direction, so that the friction coefficient in the intersecting direction is smaller than that in the conveying direction.

[0048] In this embodiment, it is preferable that the frictional force of the first transport roll pair 4 is greater than that of the transport belt 31 in the first transport unit 3A. This makes it possible for the first transport roll pair 4 to regulate the posture of the paper P during transport in the first transport unit 3A. Similarly, it is preferable that the second transport roll pair 5 has a larger frictional force than the transport belt 31 in the second transport unit 3B. This makes it possible for the second transport roll pair 5 to regulate the posture of the paper P during transport in the second transport unit 3B. The frictional force referred to here means a value obtained by multiplying the friction coefficient by the normal force.

[0049] In the present embodiment, the first transport roll pair 4 located on the upstream side of the first transport unit 3A is preferably configured with a driven transport roll 41 and an opposing roll 42 that faces the transport roll 41 and is driven by the transport roll 41. This makes it possible to increase the frictional force with a simple configuration. Similarly, it is preferable that the second transport roll pair 5 located on the upstream side of the second transport unit 3B is configured with a driven transport roll 51 and an opposing roll 52 that faces the transport roll 51 and is driven by the transport roll 51. This makes it possible to increase the frictional force with a simple configuration. [Explanation of symbols]

[0050] REFERENCE SIGNS LIST 1...image inspection device, 2A...first reading unit, 4...first transport roll pair, 5...second transport roll pair, 3A...first transport unit, 20...reading area, 31...transport belt, 41...transport roll, 42...opposing roll, 71...warp thread, 72...weft thread, 311...transport surface

Claims

1. a first conveying means for conveying a recording material to be conveyed; a second conveying means including a conveying belt which receives the recording material from the first conveying means and conveys the recording material toward a reading section which reads an image on the recording material, the conveying belt being configured such that a friction coefficient is different between a conveying direction which is a direction of conveying the recording material and a cross direction which is a direction crossing the conveying direction on a conveying surface of the conveying belt, the friction coefficient being smaller than the friction coefficient in the conveying direction; Equipped with The conveyor belt of the second conveyor means is formed of a woven fabric made of warp and weft yarns, the weft yarns of the woven fabric are exposed to a surface higher than the warp yarns, thereby forming the conveying surface of the conveying belt; The recording material conveying device, wherein the cross direction of the conveying belt is a weft direction in which the weft threads extend.

2. A first conveying means for conveying a recording material to be conveyed; a second conveying means including a conveying belt which receives the recording material from the first conveying means and conveys the recording material toward a reading section which reads an image on the recording material, the conveying belt being configured such that a friction coefficient is different between a conveying direction which is a direction of conveying the recording material and a cross direction which is a direction crossing the conveying direction on a conveying surface of the conveying belt, the friction coefficient being smaller than the friction coefficient in the conveying direction; Equipped with The conveyor belt of the second conveyor means is formed of a woven fabric made of warp and weft yarns, the woven fabric forms the conveying surface of the conveying belt by having the warp yarns protruding from the surface of the woven fabric relative to the weft yarns; A recording material conveying device, wherein the intersecting direction of the conveying belt is a warp direction in which the warp threads extend.

3. The first conveying means has a larger friction force than the conveying belt of the second conveying means, 3. The recording material transport device according to claim 1, wherein the recording material transport device is a recording material conveying device.

4. The first conveying means is composed of a driving conveying roll and a driven roll facing the conveying roll and driven by the conveying roll, 4. The recording material transport device according to claim 3.

5. A first conveying means for conveying a recording material to be conveyed; a second conveying means including a conveying belt which receives the recording material from the first conveying means and conveys the recording material toward a reading section which reads an image on the recording material, the conveying belt being configured such that a friction coefficient is different between a conveying direction which is a direction of conveying the recording material and a cross direction which is a direction crossing the conveying direction on a conveying surface of the conveying belt, the friction coefficient being smaller than the friction coefficient in the conveying direction; a third conveying means located downstream of the second conveying means in the conveying direction and having a larger frictional force than the second conveying means; Equipped with a recording material conveying device, the recording material conveying device being disposed away from the first conveying device so that a state is formed in which the recording material is conveyed by both the third conveying device and the first conveying device;

6. An image reading device including a recording material conveying device as described in claim 1, 2 or 5.

Images