Reading device, image forming device

Abstract

To provide a reading device and an image forming apparatus capable of preventing a state in which a document of a threshold length or more is sandwiched in a discharge roll from maintaining compared to a case in which a halt state of a plurality of conveying rolls maintains when a document jam occurs in a configuration in which rotation and non-rotation of the plurality of conveying rolls are interlocked.SOLUTION: When a document jam occurs inside a device body 62, a control device 80 temporarily stops a plurality of conveying rolls 70. When a discharge sensor 76c does not detect a document G and when the document G is equal to or longer than a threshold length, the control device 80 rotates the conveying rolls 70 for a predetermined time.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a reading device and an image forming apparatus. [Background technology]

[0002] The image reading device described in Patent Document 1 reads the document image of the document being conveyed by a scanner unit and a CCD sensor unit. A post-separation sensor, a lead sensor, and a paper discharge sensor provided in the conveying path detect the occurrence of a jam. There are two methods for resuming the document reading process after a jam occurs: a first resuming method in which all documents are reloaded on the document tray, and a second resuming method in which only unread documents are reloaded on the document tray, and both methods are set by the user. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-107566 A Summary of the Invention [Problem to be solved by the invention]

[0004] The reading device for reading an image formed on a document includes a plurality of transport rolls that transport the document along a transport path and rotate and non-rotate in conjunction with each other, a reading unit that reads the image formed on the document, and a plurality of detection units that are spaced apart along the transport path. The discharge detection unit that is disposed most downstream of the transport path among the plurality of detection units is disposed upstream in the transport direction of the document with respect to the discharge roll that is disposed most downstream of the transport path among the plurality of transport rolls.

[0005] In such a configuration, if a document jam occurs inside the device body, the multiple transport rolls that transport the document stop. This may cause a situation in which the document that has passed through the discharge detection unit is sandwiched between the discharge rolls. In such a case, it is conceivable that the document sandwiched between the discharge rolls can be discharged to the outside of the device body by rotating the discharge rolls for a predetermined time after the multiple transport rolls stop.

[0006] However, because the rotation and non-rotation of the multiple transport rolls are linked, when the discharge roll is rotated, the other transport rolls also rotate. When the other transport rolls rotate, the document jammed inside the device body moves. Here, for example, in the case of a short document, the jammed document may move to a location where it is difficult to remove.

[0007] The objective of the present invention is to prevent a document longer than a threshold length from being kept clamped between the discharge rolls in a configuration in which the rotation and non-rotation of multiple transport rolls are linked, compared to a case in which the multiple transport rolls are kept stopped when a document jam occurs. [Means for solving the problem]

[0008] The reading device according to a first aspect of the present invention is characterized in that it comprises: a plurality of transport rolls that transport an original along a transport path, including an output roll arranged at the most downstream side of the transport path, and whose rotation and non-rotation are linked; an opening / closing unit that opens and closes an upstream portion of the transport path; a plurality of detection units that are spaced apart along the transport path and detect the transported original, including an output detection unit arranged at the most downstream side of the transport path, and the output detection unit is arranged upstream of the output roll in the transport direction of the original; a reading unit that reads an image formed on the transported original in the downstream portion of the transport path; and a control unit that controls the transport rolls to temporarily stop the plurality of transport rolls when a document jam occurs inside the device body, and rotates the transport rolls for a predetermined time if the output detection unit does not detect the original and the original is equal to or longer than a threshold length.

[0009] A reading device according to a second aspect of the present invention is characterized in that, in the reading device described in the first aspect, the control unit determines that the document is longer than a threshold length when the length of the document is longer than a predetermined length for the longest roll-to-roll distance between a pair of adjacent transport rolls along the transport path.

[0010] A reading device according to a third aspect of the present invention is characterized in that it comprises: a plurality of transport rolls that transport an original along a transport path, including an output roll arranged at the most downstream side of the transport path, and whose rotation and non-rotation are linked; an opening / closing unit that opens and closes an upstream portion of the transport path; a plurality of detection units that are spaced apart along the transport path and detect the transported original, including an output detection unit arranged at the most downstream side of the transport path, and the output detection unit is arranged upstream of the output roll in the transport direction of the original; a reading unit that reads an image formed on the transported original in the downstream portion of the transport path; and a control unit that controls the transport rolls to temporarily stop the plurality of transport rolls when an original jam occurs inside the device body, and rotates the transport rolls for a predetermined time when the output detection unit does not detect an original and the original jammed in the upstream portion of the transport path is stopped.

[0011] A reading device according to a fourth aspect of the present invention is characterized in that, in the reading device described in the third aspect, the detection unit is arranged in an upstream portion of the transport path, and the control unit determines that the document jammed in the upstream portion of the transport path is stopped when the document passing time at which the document is detected by the detection unit arranged in the upstream portion of the transport path differs by more than a threshold time before and after the document jam occurs.

[0012] A reading device according to a fifth aspect of the present invention is characterized in that, in the reading device described in the third aspect, a pair of detection units are provided at a distance from each other in a downstream portion of the transport path and upstream of a reading position where an image is read by the reading units, and the control unit determines that when a document jam occurs, the document jammed in the upstream portion of the transport path is stopped if the upstream detection unit of the pair of detection units detects the document and the downstream detection unit does not detect the document.

[0013] An image forming apparatus according to a sixth aspect of the present invention is characterized in that it comprises a reading device as defined in any one of claims 1 to 5, and an image forming unit which forms an image read by the reading device on a recording medium. Effect of the Invention

[0014] According to the reading device of the first aspect of the present invention, in a configuration in which the rotation and non-rotation of multiple transport rolls are linked, it is possible to prevent a document longer than a threshold length from being kept clamped between the discharge rolls, compared to a case in which the multiple transport rolls are kept stopped when a document jam occurs.

[0015] According to the reading device of the second aspect of the present invention, an appropriate threshold length can be determined for each reading device, as compared with the case where the threshold length is always constant regardless of the distance between the rolls.

[0016] According to the reading device of the third aspect of the present invention, in a configuration in which the rotation and non-rotation of multiple transport rolls are linked, it is possible to prevent the document from remaining clamped between the discharge rolls when a document jam occurs, compared to a case in which the multiple transport rolls are kept stopped.

[0017] According to the reading device of the fourth aspect of the present invention, it is possible to determine that the document is stopped at an upstream portion of the transport path without increasing the number of detection units in order to determine the position at which the document is stopped.

[0018] According to the reading device of the fifth aspect of the present invention, it is possible to accurately determine whether a document is stopped in the upstream part of the transport path, compared to a case in which it is determined that a document is stopped in the upstream part of the transport path based on whether or not a single detection unit arranged in the downstream part of the transport path detects a document.

[0019] According to the image forming apparatus of the sixth aspect of the present invention, maintenance is easier than when the image forming apparatus is not provided with the reading device according to any one of the first to fifth aspects. [Brief description of the drawings]

[0020] [Figure 1] 1 is a schematic configuration diagram showing an image forming apparatus according to a first embodiment of the present invention. [Diagram 2] 1 is a configuration diagram showing a toner image forming unit provided in an image forming apparatus according to a first embodiment of the present invention. [Diagram 3] FIG. 2 is a configuration diagram showing a reading section according to the first embodiment of the present invention. [Figure 4] 1 is a configuration diagram showing a reading unit according to a first embodiment of the present invention with an access cover open; [Diagram 5] 3 is a functional block diagram showing functions of a control device provided in a reading unit according to the first embodiment of the present invention. FIG. [Figure 6] FIG. 2 is a configuration diagram showing the configuration of a control device provided in a reading unit according to the first embodiment of the present invention. [Figure 7] FIG. 2 is a diagram showing a state in which a document is being transported in the reading section according to the first embodiment of the present invention. [Figure 8] FIG. 2 is a diagram showing a state in which a document is being transported in the reading section according to the first embodiment of the present invention. [Figure 9] FIG. 2 is a diagram showing a state in which a document is being transported in the reading section according to the first embodiment of the present invention. [Figure 10] FIG. 2 is a diagram showing a state in which a document is being transported in the reading section according to the first embodiment of the present invention. [Figure 11]FIG. 2 is a diagram showing a state in which a document is being transported in the reading section according to the first embodiment of the present invention. [Figure 12] FIG. 4 is an operation flow diagram when a document jam occurs in the reading unit according to the first embodiment of the present invention. [Figure 13] FIG. 11 is a state diagram showing a state in which a document is being conveyed in a reading section according to a comparative example with respect to the first embodiment of the present invention. [Figure 14] FIG. 11 is a state diagram showing a state in which a document is being conveyed in a reading section according to a comparative example with respect to the first embodiment of the present invention. [Figure 15] FIG. 11 is an operation flow diagram when a document jam occurs in a reading unit according to the second embodiment of the present invention. [Figure 16] FIG. 10 is a state diagram showing a state in which a document is being transported in a reading section according to a second embodiment of the present invention. [Figure 17] FIG. 11 is a functional block diagram showing functions of a control device provided in a reading unit according to a second embodiment of the present invention. [Figure 18] FIG. 11 is an operation flow diagram when a document jam occurs in a reading unit according to a third embodiment of the present invention. [Figure 19] FIG. 11 is a state diagram showing a state in which a document is being transported in a reading section according to a third embodiment of the present invention. [Figure 20] FIG. 11 is a state diagram showing a state in which a document is being transported in a reading section according to a third embodiment of the present invention. [Figure 21] FIG. 11 is a functional block diagram showing functions of a control device provided in a reading unit according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] First Embodiment An example of a reading device and an image forming device according to a first embodiment of the present invention will be described with reference to Figures 1 to 14. Note that arrow H shown in the figures indicates the up-down direction (vertical direction) of the device, and arrow W indicates the width direction (horizontal direction) of the device.

[0022] (Image forming apparatus 10) 1, the image forming apparatus 10 includes a storage section 14 in which a sheet material P serving as a recording medium is stored, a transport section 16 that transports the sheet material P stored in the storage section 14, an image forming section 20 that forms an image on the sheet material P transported from the storage section 14 by the transport section 16, and a reading device 22 that reads an image formed on a document G. The storage section 14, the image forming section 20, and the reading device 22 are arranged in this order from bottom to top.

[0023] [Storage section 14, conveying section 16] As shown in FIG. 1, the storage section 14 includes a storage member 14a that can be pulled out from the device main body 10a toward the front in the device depth direction and in which the sheet material P is loaded, and a feed roll 14b that sends out the sheet material P loaded in the storage member 14a to a conveying path 28 for the sheet material P.

[0024] The conveying section 16 includes a separation roll 16a that separates and conveys the sheet members P one by one, an adjustment roll 16b that temporarily stops the sheet members P to adjust the conveying timing, and a discharge roll 16c that discharges the sheet members P to the outside of the apparatus main body 10a. The separation roll 16a, the adjustment roll 16b, and the discharge roll 16c are disposed in this order along a conveying path 28 from the upstream side to the downstream side in the conveying direction of the sheet members P.

[0025] [Reading device 22] 1, the reading device 22 is disposed above the discharge roller 16c and is configured to read an image formed on the document G. The reading device 22 will be described in detail later.

[0026] [Image forming unit 20] The image forming section 20 is disposed above the storage section 14, as shown in Fig. 1. The image forming section 20 includes a circular image holder 30, a charging member 32 that charges the surface of the image holder 30, and an exposure device 34 (see Fig. 1) that irradiates the charged surface of the image holder 30 with exposure light to form an electrostatic latent image. The image forming section 20 further includes a developing device 36 that develops the electrostatic latent image formed on the surface of the image holder 30 into a toner image, and a transfer roll 24 that transfers the toner image formed on the surface of the image holder 30 to a sheet member P that is transported along a transport path 28.

[0027] As shown in FIG. 1, the image forming unit 20 also includes a fixing device 38, which is composed of a heating roll 38h and a pressure roll 38n, and fixes the toner image on the sheet member P to the sheet member P by applying heat and pressure.

[0028] (Function of Image Forming Apparatus 10) In the image forming apparatus 10, an image is formed on the sheet member P in the following manner. First, the charging member 32 shown in Fig. 2 uniformly charges the surface of the image carrier 30 negatively at a predetermined potential. Next, based on the image data read by the reading device 22 shown in Fig. 1 or data input from an external source, the exposure device 34 irradiates the charged surface of the image carrier 30 with exposure light to form an electrostatic latent image. Furthermore, the developing device 36 develops the electrostatic latent image formed on the surface of the image carrier 30 and visualizes it as a toner image.

[0029] Thus, the sheet member P sent from the storage member 14a to the transport path 28 by the delivery roll 14b is sent to a transfer position T formed by the image holder 30 and the transfer roll 24 at a timing determined by the adjustment roll 16b. At the transfer position T, the sheet member P is sandwiched and transported between the image holder 30 and the transfer roll 24, so that the toner image formed on the surface of the image holder 30 is transferred to the sheet member P.

[0030] The fixing device 38 heats and presses the conveyed sheet member P, thereby fixing the toner image transferred to the sheet member P to the sheet member P. Then, the discharge roll 16c discharges the sheet member P with the fixed toner image to the outside of the apparatus main body 10a.

[0031] (Main part configuration) Next, the reading device 22 will be described. 3, the reading device 22 includes an original transport device 60 (ADF device) that transports a plurality of stacked originals G in sequence, a platen glass 40 on which one original G is placed, and a platen cover 42 that opens and closes the platen glass 40. Furthermore, the reading device 22 includes a reading section 44 that reads an image formed on the original G, a moving section 50 that moves the reading section 44, and a control device 80 (see FIG. 5) that controls each section.

[0032] [Platen glass 40, platen cover 42] 3, the platen glass 40 is fitted into the upper part of the device body 10a of the image forming apparatus 10. In addition, a platen cover 42 that opens and closes the platen glass 40 is disposed above the platen glass 40.

[0033] In addition, with the platen cover open to expose the platen glass 40, the document G can be placed on the platen glass 40. The document transport device 60 (ADF device) is provided on the platen cover .

[0034] [Reading unit 44] As shown in FIG. 3, the reading unit 44 is disposed below the platen glass 40 and inside the device main body 10a.

[0035] The reading unit 44 includes a rectangular parallelepiped housing 44a extending in the device depth direction (depth direction of the paper), a light source 44b, and plane mirrors 44c and 44d that reflect the light emitted from the light source 44b and reflected from the document G to a predetermined position. The reading unit 44 further includes a photoelectric conversion element 44e that converts light into an electrical signal, an imaging lens 44f that focuses the light reflected by the plane mirrors 44c and 44d on the photoelectric conversion element 44e, and a reading circuit board 44g on which the photoelectric conversion element 44e is mounted.

[0036] In this configuration, a light source 44b provided in the reading unit 44 emits light toward the document G. Then, the plane mirrors 44c and 44d reflect the light reflected from the document G toward the photoelectric conversion element 44e. The imaging lens 44f forms an image on the photoelectric conversion element 44e of the light reflected toward the photoelectric conversion element 44e. Furthermore, the photoelectric conversion element 44e sends image information to the image forming unit 20 (see FIG. 1) via the reading circuit board 44g.

[0037] [Moving unit 50] The moving unit 50 is attached to the rear and front sides of the reading unit 44 in the device depth direction, and as shown in Figure 3, is equipped with a pair of rail members 52 extending in the device width direction, and a drive unit (not shown) that moves the reading unit 44 in the device width direction along the rail members 52.

[0038] In this configuration, when the reading unit 44 reads an image formed on a document G placed on the platen glass 40, the moving unit 50 moves the reading unit 44 in the device width direction along the platen glass 40. On the other hand, when the reading unit 44 reads an image formed on a document G transported by the document transport device 60, the moving unit 50 moves the reading unit 44 to a transport reading position (position shown by a solid line in FIG. 3) opposite to the reading position R where the image formed on the document G transported by the document transport device 60 is read.

[0039] [Document transport device 60] 3, the document transport device 60 includes a device body 62 disposed on one side (left side in the figure) in the device width direction, and a loading section 56 disposed on the other side (right side in the figure) in the device width direction and on which documents G are loaded. Furthermore, the document transport device 60 includes a feed roll 74 that feeds the documents G loaded on the loading section 56 to a transport path 68 for the documents G, and a drive source 75 (see FIG. 5) that drives the feed roll 74.

[0040] Furthermore, the document transport device 60 includes a loading sensor 77 that detects the presence or absence of a document G loaded on the loading section 56, a plurality of transport rolls 70 that transport the document G along a transport path 68, and a drive source 72 (see FIG. 5) that drives the plurality of transport rolls 70. Furthermore, the document transport device 75 includes a plurality of transport sensors 76 that detect the presence or absence of a document G being transported, and a discharge section 58 that is disposed below the loading section 56 and into which the document G transported by the transport rolls 70 is discharged.

[0041] [Send Role 74] 3, the delivery roll 74 is disposed inside the device body 62 so as to contact the leading end of the uppermost document G loaded on the loading section 56. The delivery roll 74, which rotates by a driving force transmitted from a driving source 75 (see FIG. 5), delivers the documents G loaded on the loading section 56 to the transport path 68 in order.

[0042] [Transport roll 70] As shown in Fig. 3, a plurality of transport rolls 70 are provided inside the device body 62, and are arranged at intervals along a U-shaped transport path 68 that is open on the other side in the device width direction when viewed from the device depth direction. The plurality of transport rolls 70 rotated by a driving force transmitted from a drive source 72 (see Fig. 5) transport the document G sent to the transport path 68 by a delivery roll 74 along the transport path 68. Here, the rotation and non-rotation of the plurality of transport rolls 70 rotated by a driving force transmitted from the drive source 72 (see Fig. 5) are linked. In other words, a specific transport roll does not rotate alone.

[0043] In this embodiment, five transport rolls 70 are provided. Then, from the upstream side to the downstream side in the transport direction of the document G (hereinafter, "document transport direction"), a separation roll 70a, a first transport roll 70b, a second transport roll 70c, a third transport roll 70d, and an ejection roll 70e are arranged in this order.

[0044] Specifically, the separation roll 70a and the first transport roll 70b are disposed in an upstream portion 68a of the transport path 68, and the second transport roll 70c, the third transport roll 70d, and the discharge roll 70e are disposed in a downstream portion 68b of the transport path 68. The upstream portion 68a and the downstream portion 68b of the transport path 68 will be described in detail later.

[0045] -Separation roll 70a, first transport roll 70b- The separation roll 70a is disposed downstream of the delivery roll 74 in the document transport direction so as to receive the document G from the delivery roll 74. The separation roll 70a prevents the document G from being fed multiple times and transports the document G one by one downstream in the document transport direction.

[0046] The first transport roll 70b is disposed downstream of the separation roll 70a in the document transport direction so as to receive the document G from the separation roll 70a.

[0047] -Second transport roll 70c, third transport roll 70d, discharge roll 70e-

[0048] The second transport roll 70c is disposed downstream of the first transport roll 70b in the document transport direction and upstream of the reading position R so as to receive the document G from the first transport roll 70b. In this embodiment, the reading position R is located in the upstream portion of the downstream portion 68b of the transport path 68 in the document transport direction.

[0049] The third transport roll 70d is disposed so as to receive the document G from the second transport roll 70c downstream in the document transport direction with respect to the reading position R. In other words, the third transport roll 70d is disposed on the opposite side of the second transport roll 70c with the reading position R therebetween.

[0050] The discharge roll 70e is disposed downstream of the third transport roll 70d in the document transport direction so as to receive the document G from the third transport roll 70d. The discharge roll 70e is configured to sequentially discharge the document G transported along the transport path 68 to the discharge section 58.

[0051] [Device body 62, others] 3, the device body 62 includes an opening / closing cover 64 that opens the inside of the device body 62, and a shaft portion 66 that rotatably supports the opening / closing cover 64. The device body 62 also includes guide surfaces (reference numbers omitted) that are arranged on both sides of the device body 62 with the transport path 68 therebetween when viewed from the device depth direction, and that guide the transported document G. The opening / closing cover 64 is an example of an opening / closing portion.

[0052] In this configuration, by rotating the opening / closing cover 64 around the shaft 66, the opening / closing cover 64 moves between an open position (see FIG. 4) where the upstream portion 68a of the U-shaped transport path 68 is opened upward, and a closed position (see FIG. 3) where the upstream portion 68a of the transport path 68 is covered from above. Specifically, the opening / closing cover 64 is disposed in the open position and the closed position by hitting a stopper (not shown). Note that the device body 62 is provided with guide surfaces (reference numerals omitted) on both sides of the transport path 68 when viewed from the device depth direction, for guiding the transported document G.

[0053] Here, the upstream portion 68a of the transport path 68 refers to the portion of the transport path 68 that is opened by the opening / closing cover 64, and is the portion of the transport path 68 that includes the opposing portion that faces the shaft portion 66 in the device width direction and is upstream of the opposing portion in the document transport direction. On the other hand, the downstream portion 68b of the transport path 68 refers to the portion of the transport path 68 that is not opened by the opening / closing cover 64, and is the portion of the transport path 68 that does not include the opposing portion that faces the shaft portion 66 in the device width direction and is downstream of the opposing portion in the document transport direction.

[0054] Furthermore, the document transport device 60 is provided with an opening / closing sensor 65 that detects the open / closed state of the opening / closing cover 64. The opening / closing sensor 65 detects whether the opening / closing cover 64 is disposed in the open position or the closed position.

[0055] [Load Sensor 77] The loading sensor 77 is an optical sensor that is arranged inside the device main body 62, downstream of the feed roll 74 in the document transport direction, as shown in Figure 3, and is configured to detect the presence or absence of a document G loaded in the loading section 56.

[0056] [Transport sensor 76] 3, a plurality of transport sensors 76 are provided inside the device body 62, and are spaced apart so as to face the U-shaped transport path 68 when viewed from the device depth direction. The transport sensors 76 detect the presence or absence of the document G on the opposing portion of the transport path 68. The transport sensors 76 are an example of a detection unit.

[0057] There are three transport sensors 76, and an upstream sensor 76a, a registration sensor 76b, and a discharge sensor 76c are arranged in this order from the upstream side to the downstream side in the document transport direction. The discharge sensor 76c is an example of a discharge detection unit.

[0058] Specifically, the upstream sensor 76a is disposed downstream of the separation roll 70a and upstream of the first transport roll 70b in the upstream portion 68a of the transport path 68 in the document transport direction. The registration sensor 76b is disposed downstream of the second transport roll 70c in the downstream portion 68b of the transport path 68 in the document transport direction and upstream of the reading position R. The discharge sensor 76c is disposed upstream of the discharge roll 70e in the downstream portion 68b of the transport path 68 in the document transport direction and in close proximity to the discharge roll 70e.

[0059] [Control device 80] 6, the control device 80 includes a CPU (Central Processing Unit) 81, a ROM (Read Only Memory) 82, a RAM (Random Access Memory) 83, a storage 84, and a communication interface (I / F) 85. Each component is connected to each other via a bus 88 so as to be able to communicate with each other.

[0060] The CPU 81 is a central processing unit, and executes various programs and controls each part. That is, the CPU 81 reads out a program from the ROM 82 or the storage 84, and executes the program using the RAM 83 as a working area. The CPU 81 controls each component and performs various arithmetic processing according to the program recorded in the ROM 82 or the storage 84. In this embodiment, the ROM 82 or the storage 84 stores a control program for when a document G is jammed inside the device main body 62.

[0061] 5, the control device 80 acquires detection information from each unit. For example, the control device 80 derives the length of the transported document G in the transport direction based on the detection result of the upstream sensor 76a. Furthermore, the control device 80 controls the reading unit 44 based on the detection result of the registration sensor 76b, and causes the reading unit 44 to read the document G. The control device 80 also controls the drive source 72 to rotate the transport roll 70. The control device 80 is an example of a control unit. Other configurations of the control device 80 will be described below together with the operation thereof.

[0062] (Function of main components) Next, the operation of the reading device 22 will be described. Specifically, the operation of each part when the reading device 22 shown in Fig. 3 reads an image formed on the document G loaded on the loading section 56 will be described. More specifically, the operation of each part of the reading device 22 will be described separately for a normal time when the images formed on the document G being transported are read in order, and a time when the document G becomes jammed inside the device main body 62.

[0063] The operation of each part described below is performed by controlling each part through the control device 80. When no image reading instruction is given to the reading device 22, the drive sources 72 and 75 are not operated, and the reading unit 44 is disposed at a transport reading position opposite the reading position R where the image is read.

[0064] [Normal time] 3, when a user places a plurality of documents G on the stacking unit 56, a stacking sensor 77 detects the documents G stacked on the stacking unit 56. Furthermore, when the user issues an instruction to read an image from a user interface (UI) (not shown), a control device 80 shown in FIG. 5 operates a driving source 75 to rotate the delivery roll 74. Furthermore, the control device 80 operates a driving source 72 to rotate all of the transport rolls 70.

[0065] 7, the rotating feed roll 74 sends out the topmost document G to the transport path 68. The rotating separation roll 70a receives the document G sent out to the transport path 68, and when the documents G are overlapped, transports only one document G downstream in the document transport direction. When the separation roll 70a receives the document G from the feed roll 74, the driving force transmitted from the drive source 75 to the feed roll 74 stops.

[0066] Furthermore, the rotating first transport roll 70b receives the original G from the separation roll 70a and transports the received original G downstream in the original transport direction. Also, an upstream sensor 76a disposed between the separation roll 70a and the first transport roll 70b in the transport path 68 detects the transported original G. Then, the control device 80 derives the length of the original G in the transport direction based on the time during which the upstream sensor 76a detects the original G. Here, the control device 80 derives the length of the original G in the transport direction every time the upstream sensor 76a detects the original G.

[0067] The length of the document G obtained by the upstream sensor 76a is stored in the ROM 82 shown in FIG.

[0068] 8, the rotating second transport roll 70c receives the document G from the first transport roll 70b and transports the received document G downstream in the document transport direction. A registration sensor 76b disposed between the second transport roll 70c and the reading position R in the transport path 68 detects the transported document G. The control device 80 controls the reading unit 44 to read the image formed on the document G based on the timing (time point) when the document G is detected by the registration sensor 76b.

[0069] 9, the rotating third transport roll 70d receives the document G from the second transport roll 70c and transports the received document G downstream in the document transport direction. Then, the discharge sensor 76c detects the document G transported downstream in the document transport direction by the third transport roll 70d.

[0070] Furthermore, the rotating discharge roll 70e receives the original G from the third transport roll 70d, and discharges the received original G to the discharge section 58, as shown in FIGS.

[0071] Furthermore, the control device 80 operates the drive source 75 to rotate the delivery roll 74 at the timing (time point) when the previously transported document G passes the registration sensor 76b, and sends out the topmost document G to the transport path 68 as shown in Fig. 7. Then, by repeating the above-mentioned process, the reading unit 44 sequentially reads the images formed on the documents G stacked on the stacking unit 56.

[0072] [When a document jam occurs] The document G transported during normal operation may become jammed inside the device body 62. Specifically, when the time during which the document G is detected by the upstream sensor 76a, the register sensor 76b, or the discharge sensor 76c is equal to or longer than a threshold time, the control device 80 determines that a document jam has occurred. Also, when the time from when the upstream transport sensor 76 detects the document G in the document transport direction until the downstream transport sensor 76 detects the document G is equal to or longer than a threshold time, the control device 80 determines that a document jam has occurred.

[0073] The operation of each part when the control device 80 determines that a document jam has occurred will be described with reference to the flow chart shown in Fig. 12. When the control device 80 determines that a document jam has occurred, it puts the drive source 72 into a non-operating state and stops the rotation of all the transport rolls 70. Then, the process proceeds to step S100.

[0074] In step S100, the control device 80 determines whether the discharge sensor 76c is in a non-detection state in which it is not detecting the document G. If the discharge sensor 76c is in a non-detection state, the process proceeds to step S200, and if the discharge sensor 76c is not in a non-detection state (if it is in a detection state), the process proceeds to step S400.

[0075] In step S200, the control device 80 determines whether the length of the document G being transported in the transport direction is equal to or greater than a threshold. Specifically, the control device 80 determines that the length of the document G in the transport direction is equal to or greater than the threshold length when the length of the document G in the transport direction is equal to or greater than a predetermined length for the longest inter-roll distance among the distances between a pair of transport rolls 70 adjacent to each other in the document transport direction. Furthermore, the control device 80 determines that the length of the document G in the transport direction is less than the threshold length when the length of the document G in the transport direction is less than a predetermined length for the longest inter-roll distance among the distances between a pair of transport rolls 70 adjacent to each other in the document transport direction.

[0076] In this embodiment, the longest inter-roll distance is the distance between the separation roll 70a and the first transport roll 70b. For example, when the distance between the separation roll 70a and the first transport roll 70b is 100 and the length of the document G is 140 or more, the control device 80 determines that the length of the document G in the transport direction is equal to or greater than the threshold length. In other words, the control device 80 determines that the length of the document G in the transport direction is not less than the threshold length.

[0077] If the length of the document G in the transport direction is equal to or greater than the threshold length, the process proceeds to step S300, and if the length of the document G in the transport direction is less than the threshold length, the process proceeds to step S400.

[0078] In step S300, the control device 80 controls the driving source 72 to rotate all the transport rolls 70 for a predetermined time.

[0079] Here, the "predetermined time" will be described. As shown in Fig. 10, when the document G has passed the discharge sensor 76c but is caught between the discharge rolls 70e, and the control device 80 determines that a document jam has occurred, all the transport rolls 70 including the discharge rolls 70e are stopped. In other words, the document G that has already passed the reading position R and has had its image read may be caught between the discharge rolls 70e and not be discharged to the discharge section 58. The user may consider the document G that has not been discharged to the discharge section 58 as a document G whose image has not been read, and may return the document G to the stacking section 56 again.

[0080] In order to avoid such a case, all the transport rolls 70 including the discharge roll 70e are rotated for the time required for the document G that has passed the discharge sensor 76c and is sandwiched between the discharge rolls 70e to be discharged to the discharge section 58. In other words, "for the predetermined time" means "for the time required for the document G that has passed the discharge sensor 76c and is sandwiched between the discharge rolls 70e to be discharged to the discharge section 58". This time is stored in advance in the ROM 82 shown in FIG. 6. For example, the predetermined time is the time required for the discharge roll 70e with the larger diameter to rotate half a turn. Although the time is expressed as "time", the time here has the same meaning as the "amount" of half a turn and the "length" of half the circumference of the roll.

[0081] Here, the reason why the control device 80 rotates the transport roll 70 for a predetermined time only when the document G is equal to or longer than the threshold length will be described. Specifically, a reading device 522 according to a comparative embodiment in which the control device 580 rotates the transport roll 70 for a predetermined time regardless of the length of the document G will be described with reference to Figs. 13 and 14. Regarding the reading device 522 according to the comparative embodiment, differences from the reading device 22 will be mainly described.

[0082] In the reading device 522, the rotation and non-rotation of all the transport rolls 70 are linked. Therefore, when the discharge roll 70e is rotated, the other transport rolls 70 also rotate. For example, when it is determined that a document jam has occurred, as shown in FIG. 13, a document G whose rear end portion is located at the upstream portion 68a of the transport path 68 and whose front end portion is located at the downstream portion 68b of the transport path 68 may stop midway along the transport path 68.

[0083] Here, in the reading device 522 according to the comparative embodiment, the control device 580 rotates all the transport rolls 70 for a predetermined time regardless of the length of the document G. In other words, the control device 580 rotates all the transport rolls 70 even when the length of the document G in the transport direction is less than the threshold value. As a result, when there is a document G that has passed the discharge sensor 76c and is sandwiched between the discharge rolls 70e, this document G is discharged to the discharge section 58.

[0084] However, if all of the transport rolls 70 are rotated even when the length of the original G in the transport direction is less than the threshold value, the entire original G that has stopped midway along the transport path 68 may move to the downstream portion 68b of the transport path 68, as shown in Figures 13 and 14.

[0085] In this way, when the length of the document G in the transport direction is less than the threshold value, the entire document G moves to the downstream portion 68b of the transport path 68, which is not opened even when the opening / closing cover 64 is placed in the open position. When the entire document G moves to the downstream portion 68b of the transport path 68, it becomes difficult to remove the document G even when the opening / closing cover 64 is placed in the open position.

[0086] In order to avoid such a case, in this embodiment, the transport roll 70 is rotated only when the length of the document G in the transport direction is equal to or longer than a threshold length. Then, in this embodiment, when all the transport rolls 70 have rotated for a predetermined time, the process proceeds to step S400.

[0087] In step S400, the control device 80 displays the occurrence of a document jam on the user interface, and then the process proceeds to step S500.

[0088] In step S500, the control device 80 judges whether the opening / closing cover 64 has been opened or closed. The opening / closing of the opening / closing cover 64 is detected by the opening / closing sensor 65 shown in Figs. 3 and 4. Specifically, a user who sees the display indicating the occurrence of a document jam opens the opening / closing cover 64 to remove the jammed document G, and then closes the opening / closing cover 64 after removing the document G. Therefore, the control device 80 judges whether the opening / closing cover 64 has been opened or closed. If the opening / closing cover 64 has been opened or closed, the process proceeds to step S600. Note that if the opening / closing cover 64 has not been opened or closed, the process proceeds to step S400, and the control device 80 maintains the state in which the occurrence of a document jam is displayed on the user interface.

[0089] In step S600, the control device 80 determines whether or not all of the transport sensors 76 are in a non-detection state in which they are not detecting the document G. If all of the transport sensors 76 are in a non-detection state, the process proceeds to step S700. However, if any of the transport sensors 76 is in a detection state in which it is detecting the document G, the process proceeds to step S400, and the control device 80 maintains a state in which the occurrence of a document jam is displayed on the user interface.

[0090] In step S700, the control device 80 displays on the user interface a message to return the removed document G to the stacking unit 56, and ends the series of operations.

[0091] If the discharge sensor 76c is not in a non-detecting state (is in a detecting state) in step S100, the process proceeds to step S400, and the occurrence of a document jam is displayed on the user interface, and then the process proceeds to step S500.

[0092] Also, in step S200, if it is determined that the length of the document G is less than the threshold length, the process proceeds to step S400, and the occurrence of a document jam is displayed on the user interface, and then the process proceeds to step S500.

[0093] (summary) As described above, in the reading device 22, when a document jam occurs and the length of the document G in the transport direction is equal to or longer than the threshold length, all of the transport rolls 70 including the discharge roll 70e are rotated for a predetermined time. Therefore, in a configuration in which the rotation and non-rotation of multiple transport rolls are linked, a document G of equal to or longer than the threshold length is prevented from being kept sandwiched between the discharge rolls 70e, compared to a case in which the multiple transport rolls are kept stopped when a document jam occurs.

[0094] Furthermore, in the reading device 22, when a document jam occurs and the length of the document G in the transport direction is equal to or greater than the threshold length, all of the transport rolls 70 including the discharge roll 70e are rotated. This prevents the entire document G, whose length in the transport direction is less than the threshold, from moving to the downstream portion 68b in the transport path 68. In other words, when the length of the document G in the transport direction is less than the threshold, by maintaining all of the transport rolls 70 including the discharge roll 70e in a stopped state and opening the open / close cover 64, the document G whose length in the transport direction is less than the threshold can be easily removed.

[0095] Furthermore, in the reading device 22, the control device 80 determines that the length of the document G in the transport direction is equal to or greater than the threshold length when the length is equal to or greater than a predetermined length for the longest inter-roll distance between a pair of transport rolls 70 adjacent to each other in the document transport direction. Here, the inter-roll distance is determined in consideration of the shortest document G whose image can be read by the reading device 22. Therefore, compared to the case where the threshold length is always constant regardless of the inter-roll distance, an appropriate threshold length is determined for each reading device.

[0096] In addition, in the image forming device 10, if a document jam occurs, the document G whose length in the transport direction is less than the threshold value is retained in a position where it can be easily removed, making maintenance easier than when the reading device 22 is not provided.

[0097] <Second embodiment> Next, an example of a reading device and an image forming device according to a second embodiment of the present invention will be described with reference to Figures 15 to 17. Note that, regarding the second embodiment, differences from the first embodiment will be mainly described.

[0098] A control device 180 (see FIG. 17) provided in the reading device 122 according to the second embodiment controls each part. Hereinafter, the operation of each part when the control device 180 determines that a document jam has occurred will be described with reference to the flow chart shown in FIG.

[0099] [When a document jam occurs] When the control device 180 determines that a document jam has occurred, it puts the driving source 72 out of operation and stops all the transport rollers 70. Then, the process proceeds to step S1100.

[0100] In step S1100, the control device 180 determines whether the discharge sensor 76c is in a non-detecting state. If the discharge sensor 76c is in a non-detecting state, the process proceeds to step S1200, and if the discharge sensor 76c is not in a non-detecting state (if the discharge sensor is in a detecting state), the process proceeds to step S1400.

[0101] In step S1200, the control device 180 determines whether or not the original G is stopped in the upstream portion 68a of the transport path 68 shown in Fig. 16. Specifically, the control device 180 determines whether or not the original passing time at which the original G is detected by the upstream sensor 76a arranged in the upstream portion 68a of the transport path 68 differs by a threshold time or more before and after the occurrence of the original jam. The original passing time is the time at which the original G is detected by the upstream sensor 76a.

[0102] Here, the document passing time immediately before the document jam occurs and the transport roll 70 stops is defined as the "post-occurrence passing time." On the other hand, the document passing time immediately before the post-occurrence passing time is defined as the "normal passing time." If the post-occurrence passing time is, for example, 1.2 times or more the normal passing time, the control device 180 determines that the document passing time before and after the document jam occurs differs by more than the threshold time.

[0103] When the document passing time detected by the upstream sensor 76a located in the upstream portion 68a of the transport path 68 differs by more than a threshold time before and after the occurrence of a document jam, the control device 180 determines that the document G is stopped in the upstream portion 68a of the transport path 68, as shown in FIG. 16.

[0104] If the document passing time before and after the document jam occurs differs by more than the threshold time, the process proceeds to step S1300, and if the document passing time is different from the above, the process proceeds to step S1400.

[0105] In step S1300, the control device 180 controls the driving source 72 to rotate all of the transport rolls 70 for a predetermined time. When all of the transport rolls 70 have rotated for the predetermined time, the process proceeds to step S1400.

[0106] In step S1400, control device 180 displays the occurrence of a document jam on the user interface, and then the process proceeds to step S1500.

[0107] In step S1500, control device 180 determines whether opening / closing cover 64 has been opened or closed. Whether opening / closing cover 64 has been opened or closed is detected by opening / closing sensor 65 shown in Fig. 16. If opening / closing cover 64 has been opened or closed, the process proceeds to step S1600. If opening / closing cover 64 has not been opened or closed, the process proceeds to step S1400, and control device 180 maintains the state in which the occurrence of a document jam is displayed on the user interface.

[0108] In step S1600, the control device 180 determines whether or not all of the transport sensors 76 are in a non-detection state in which they are not detecting the document G. If all of the transport sensors 76 are in a non-detection state in which they are not detecting the document G, the process proceeds to step S1700. However, if any of the transport sensors 76 are in a detection state in which they are detecting the document G, the process proceeds to step S1400, and the control device 180 maintains a state in which the occurrence of a document jam is displayed on the user interface.

[0109] In step S1700, the control device 180 displays on the user interface a message to return the removed document G to the stacking unit 56, and ends the series of operations.

[0110] If the discharge sensor 76c is not in a non-detecting state (is in a detecting state) in step S1100, the process proceeds to step S1400, and the occurrence of a document jam is displayed on the user interface, and then the process proceeds to step S1500.

[0111] Also, in step S1200, if the document passing time does not differ by more than the threshold time before and after the document jam occurs, the process proceeds to step S1400, and the occurrence of a document jam is displayed on the user interface, and then the process proceeds to step S1500.

[0112] (summary) As described above, in the reading device 122, when a document jam occurs, all of the transport rolls 70 including the discharge roll 70e are rotated for a predetermined time while the document G is stopped in the upstream portion 68a of the transport path 68. Therefore, compared to the case where a plurality of transport rolls are kept stopped when a document jam occurs, the document G is prevented from being kept sandwiched between the discharge rolls 70e.

[0113] Furthermore, in the reading device 122, when the document G is stopped in the upstream portion 68a of the transport path 68, all the transport rolls 70 including the discharge roll 70e are rotated for a predetermined time. Therefore, even if the transport rolls 70 are rotated, at least a part of the document G that was stopped in the upstream portion 68a of the transport path 68 remains in the upstream portion 68a of the transport path 68. As a result, by placing the opening / closing cover 64 in the open position, the document G that has moved in the upstream portion 68a of the transport path 68 is removed.

[0114] Furthermore, in the reading device 122, when the document passing time detected by the upstream sensor 76a differs by a threshold time or more before and after the occurrence of a document jam, the control device 180 determines that the document G is stopped in the upstream portion 68a of the transport path 68. Therefore, it is determined that the document G is stopped in the upstream portion 68a of the transport path 68 without increasing the number of sensors to determine the position where the document G is stopped.

[0115] <Third embodiment> Next, an example of a reading device and an image forming device according to a third embodiment of the present invention will be described with reference to Figures 18 to 21. Note that, with regard to the third embodiment, differences from the second embodiment will be mainly described.

[0116] A control device 280 (see FIG. 21) provided in the reading device 222 according to the third embodiment controls each part. As shown in FIG. 19, the reading device 222 has a pair of transport sensors 76 arranged at an interval in the downstream part 68b of the transport path 68 and upstream of the reading position R in the document transport direction. Specifically, a registration sensor 76b and an auxiliary sensor 76d are arranged in this order from the upstream side to the downstream side in the document transport direction. The operation of each part when the control device 280 determines that a document jam has occurred will be described below with reference to the flow chart shown in FIG. 18.

[0117] [When a document jam occurs] When the control device 280 determines that a document jam has occurred, it puts the drive source 72 out of operation and stops all the transport rollers 70. Then, the process proceeds to step S2100.

[0118] In step S2100, the control device 280 determines whether the discharge sensor 76c is in a non-detecting state. If the discharge sensor 76c is in a non-detecting state, the process proceeds to step S2200, and if the discharge sensor 76c is not in a non-detecting state (if it is in a detecting state), the process proceeds to step S2400.

[0119] In step S2200, the control device 280 determines whether or not the document G is stopped in the upstream portion 68a of the transport path 68 shown in Fig. 19. Specifically, the control device 280 determines whether or not the upstream registration sensor 76b is in a detection state in which the document G is detected, and the downstream auxiliary sensor 76d is in a non-detection state in which the document G is not detected.

[0120] Because the upstream registration sensor 76b is in a detecting state and the downstream auxiliary sensor 76d is in a non-detecting state, the control device 280 determines that the document G is stopped in the upstream portion 68a of the conveying path 68, as shown in FIG. 19.

[0121] If the registration sensor 76b is in a detecting state and the auxiliary sensor 76d is in a non-detecting state, the process proceeds to step S2300, and otherwise the process proceeds to step S2400.

[0122] In step S2300, the control device 280 controls the drive source 72 to rotate all the transport rolls 70 for a predetermined time. Since the document G is stopped in the upstream portion 68a of the transport path 68, even if all the transport rolls 70 are rotated for the predetermined time, at least a part of the document G remains in the upstream portion 68a of the transport path 68, as shown in Fig. 20. When all the transport rolls 70 have rotated for the predetermined time, the process proceeds to step S2400.

[0123] In step S2400, control device 280 displays the occurrence of a document jam on the user interface, and then the process proceeds to step S2500.

[0124] In step S2500, control device 280 determines whether opening / closing cover 64 has been opened or closed. If opening / closing cover 64 has been opened or closed, the process proceeds to step S2600. If opening / closing cover 64 has not been opened or closed, the process proceeds to step S2400, and control device 280 maintains the state in which the occurrence of a document jam is displayed on the user interface.

[0125] In step S2600, the control device 280 determines whether or not all of the transport sensors 76 are in a non-detection state in which they are not detecting the document G. If all of the transport sensors 76 are in a non-detection state in which they are not detecting the document G, the process proceeds to step S2700. However, if any of the transport sensors 76 are in a detection state in which they are detecting the document G, the process proceeds to step S2400, and the control device 280 maintains a state in which the occurrence of a document jam is displayed on the user interface.

[0126] In step S2700, the control device 280 displays on the user interface a message to return the removed document G to the stacking unit 56, and ends the series of operations.

[0127] If the discharge sensor 76c is not in a non-detecting state (is in a detecting state) in step S2100, the process proceeds to step S2400, and the occurrence of a document jam is displayed on the user interface, and then the process proceeds to step S2500.

[0128] Also, in step S2200, if the register sensor 76b is in a detecting state and the auxiliary sensor 76d is not in a non-detecting state, the process proceeds to step S2400, and the occurrence of a document jam is displayed on the user interface, and then the process proceeds to step S2500.

[0129] (summary) As described above, in the reading device 222, when a document jam occurs, all of the transport rolls 70 including the discharge roll 70e are rotated for a predetermined time while the document G is stopped in the upstream portion 68a of the transport path 68. Therefore, compared to the case where a plurality of transport rolls are kept stopped when a document jam occurs, the document G is prevented from being kept sandwiched between the discharge rolls 70e.

[0130] Furthermore, in the reading device 222, when the document G is stopped in the upstream portion 68a of the transport path 68, all the transport rolls 70 including the discharge roll 70e are rotated for a predetermined time. Therefore, even if the transport rolls 70 are rotated, at least a part of the document G that was stopped in the upstream portion 68a of the transport path 68 remains in the upstream portion 68a of the transport path 68. As a result, by placing the opening / closing cover 64 in the open position, the document G that has moved in the upstream portion 68a of the transport path 68 is removed.

[0131] In addition, in the reading device 222, the control device 280 determines that the document G is stopped at the upstream portion 68a of the conveying path 68 when the upstream registration sensor 76b is in a detecting state and the downstream auxiliary sensor 76d is in a non-detecting state. In other words, the control device 280 determines that the document G is stopped at the upstream portion 68a of the conveying path 68 based on the leading end position of the document G jammed inside the device main body 62. For this reason, it is accurately determined that the document G is stopped at the upstream portion 68a of the conveying path 68 compared to a case where it is determined that the document G is stopped at the upstream portion 68a of the conveying path 68 based on whether or not one sensor arranged in the downstream portion 68b of the conveying path 68 is in a detecting state.

[0132] Although the present invention has been described in detail with respect to a specific embodiment, it is clear to those skilled in the art that the present invention is not limited to the embodiment, and various other embodiments are possible within the scope of the present invention. For example, in the above embodiment, an optical sensor is used as the transport sensor 76, but a mechanical sensor that comes into contact with the transported document G to detect the presence or absence of the document G may also be used.

[0133] In the first embodiment, when the distance between the separation roll 70a and the first transport roll 70b is 100, the length of the document G is determined to be equal to or greater than the threshold length when the length of the document G is 140 or greater, but the length may be other than 140. For example, the length may be equal to or greater than 160.

[0134] Also, although not specifically explained in the second and third embodiments above, when a document jam occurs, it may be determined that the document G is stopped in the upstream portion 68a of the transport path 68 when the upstream sensor 76a is in a detection state in which it detects the document G. [Explanation of symbols]

[0135] 10 Image forming device 20 Image forming section 22 Reading device 44 Reading unit 62 Device body 64 Opening and closing cover (example of opening and closing part) 68 Transport Route 68a upstream section 68b Downstream section 70 Transport roll 70a Separation roll (an example of a transport roll) 70b First conveying roll (an example of a conveying roll) 70c Second transport roll (an example of a transport roll) 70d Third transport roll (an example of a transport roll) 70e Discharge roll (an example of a transport roll) 76 Transport sensor (an example of a detection unit) 76a Upstream sensor (an example of a detection unit) 76b Cash register sensor (an example of a detection unit) 76c Discharge sensor (an example of a detection unit) 76d Auxiliary sensor (an example of a detection unit) 80 Control device (an example of a control unit) 122 Reading device 180 Control device (an example of a control unit) 222 Reading device 280 Control device (an example of a control unit)

Claims

1. a plurality of transport rolls that transport the document along a transport path and that include an ejection roll disposed at the most downstream side of the transport path, the transport rolls being linked in rotation and non-rotation; an opening / closing unit that opens and closes an upstream portion of the transport path; a plurality of detection units provided at intervals along the transport path, detecting the transported document, the detection unit including a discharge detection unit disposed at the most downstream side of the transport path, the discharge detection unit being disposed upstream of the discharge roll in the document transport direction; a reading unit that reads an image formed on a document being transported in a downstream portion of the transport path; a control unit that, when a document jam occurs inside the device body, controls the transport rolls to temporarily stop the transport rolls, and, when the discharge detection unit does not detect the document and the document is equal to or longer than a threshold length, rotates the transport rolls for a predetermined time; A reading device comprising:

2. the control unit determines that the length of the document is equal to or longer than a threshold length when the length of the document is equal to or longer than a predetermined length for a longest inter-roll distance between a pair of transport rolls adjacent to each other along the transport path.

2. The reading device according to claim 1.

3. a plurality of transport rolls that transport the document along a transport path and that include an ejection roll disposed at the most downstream side of the transport path, the transport rolls being linked in rotation and non-rotation; an opening / closing unit that opens and closes an upstream portion of the transport path; a plurality of detection units provided at intervals along the transport path, detecting the transported document, the detection unit including a discharge detection unit disposed at the most downstream side of the transport path, the discharge detection unit being disposed upstream of the discharge roll in the document transport direction; a reading unit that reads an image formed on a document being transported in a downstream portion of the transport path; a control unit that, when a document jam occurs inside the device body, controls the transport rolls to temporarily stop the plurality of transport rolls, and rotates the transport rolls for a predetermined time when the discharge detection unit does not detect a document and the jammed document is stopped in an upstream portion of the transport path; A reading device comprising:

4. The detection unit is disposed in an upstream portion of the transport path, the control unit determines that the document jammed in the upstream portion of the transport path is stopped when a difference between a document passing time at which the document is detected by the detection unit disposed in the upstream portion of the transport path and a document jam occurs is equal to or greater than a threshold time.

4. The reading device according to claim 3.

5. a pair of the detection units are provided at a distance from each other in a downstream portion of the transport path and upstream of a reading position where an image is read by the reading unit; When a document jam occurs, the control unit determines that the document jammed in the upstream portion of the transport path is stopped if the upstream detection unit of the pair of detection units detects the document and the downstream detection unit does not detect the document.

4. The reading device according to claim 3.

6. A reading device according to any one of claims 1 to 5, an image forming unit that forms an image read by the reading device on a recording medium; An image forming apparatus comprising:

Images