TWI495325B - A sheet conveyance device, an image reading device, and an image forming device - Google Patents

Description

Sheet conveying device, image reading device and image forming device

The present invention relates to a sheet conveying device, an image reading device, and an image forming device.

Patent Document 1 describes an original document reading device which is constructed by using one of two conventional driving sources, thereby achieving downsizing and cost reduction.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Japanese Patent No. 3546822

An object of the present invention is to provide a sheet conveying apparatus having a driving means that can selectively rotate in the first direction and the second direction, in a rotation period other than when the driving means has to stop in order to change the rotation direction. The frequency of stopping the rotation due to the conveyance stop instruction from the external device including the image reading unit can be suppressed.

In the sheet conveying device according to the first aspect of the invention, the first conveying path of the sheet is provided, and the image of the sheet is read from the supply position of the sheet by the image reading unit. Reading position until the sheet is ejected a discharge position of the material; a second transport path of the sheet from the first position to the second position on the first transport path, wherein the second position is located on the first transport path more than the first position The upstream side of the sheet conveying direction; the driving means selectively rotating in the first direction and the second direction to generate a driving force; and the first conveying roller is driven by the driving means at the second position The second conveyance roller rotates by the driving force generated by the driving means at a position on the downstream side of the first conveyance direction in the conveyance direction on the first conveyance path. And rotating the sheet; the rotation mechanism rotates the sheet in the rotation direction of the sheet from the second position to the first position on the first conveyance path regardless of the rotation direction of the driving means a first transporting roller; an obtaining means for obtaining an instruction to start and stop the conveyance of the sheet from an external device including the image reading unit; and a control means for the driving means In the above-described control means, the driving means rotates in the first direction to start the conveyance of the sheet supplied from the supply position, and the sheet passes the position of the first conveying roller on the first conveying path. Further, when the conveyance means is moved to the position of the second conveyance roller, the drive means is rotated in the second direction to change the rotation direction of the second conveyance roller, and the sheet is conveyed to the above via the second conveyance path. When the position of the first conveyance roller is stopped, the drive means is stopped, and when the instruction to stop the conveyance of the sheet is obtained by the acquisition means, the instruction to start the conveyance of the sheet is obtained. On the other hand, when the instruction to start the conveyance of the sheet is obtained by the acquisition means, the driving means is rotated in the first direction to change the rotation direction of the second conveyance roller. After the sheet passes the position of the first conveyance roller, it is conveyed by the second conveyance roller and discharged.

The sheet conveying device according to the second aspect of the invention, comprising: a first guiding member that guides a conveying direction of the sheet along the first conveying path; and a second guiding member The first guiding member guides the conveying direction of the sheet along the first conveying path on the upstream side in the sheet conveying direction, and the connecting portion such that the second guiding member can move away from the first The first guiding member and the second guiding member are coupled to each other in a direction in which the guiding member rotates, and the control means contacts the sheet with the first conveying roller, and the leading end of the sheet is in the first conveyance When the path is located on the downstream side in the transport direction from the connecting portion, the driving means is stopped.

In the sheet conveying device according to the third aspect of the invention, the third conveying roller is provided on the first conveying path, and is closer to the downstream side in the conveying direction than the connecting portion. (2) The conveyance roller is rotated on the upstream side in the conveyance direction by the driving force generated by the driving means, and is conveyed while the sheet is interposed between the third conveyance roller and the opposing roller facing the opposite direction. In the above-mentioned control means, when the sheet is in contact with the first conveyance roller and the leading end of the sheet is located on the upstream side of the third conveyance roller in the conveyance direction on the first conveyance path, the driving is performed. The means stop.

The image reading apparatus according to any one of the first to third aspects of the present invention, characterized in that the sheet reading apparatus according to any one of the first to third aspect of the present invention The sheet conveyed by the material conveying device reads an image.

The image forming apparatus according to the fifth aspect of the present invention, characterized in that the image reading apparatus according to the fourth aspect of the invention, and an image forming apparatus that reads the image read by the image reading apparatus The image is formed on a recording medium.

According to the invention of the first aspect of the invention, the instruction to start the conveyance of the sheet and the stop of the conveyance when the driving means is stopped in order to change the rotation direction thereof may be stopped in order to change the rotation direction in addition to the driving means. In the rotation period other than the time, the frequency of stopping the rotation due to the instruction to stop the conveyance from the external device including the image reading unit is suppressed.

According to the invention of the second aspect of the invention, the configuration in which the driving means is stopped when the sheet is in contact with the first conveying roller and the leading end of the sheet is located on the downstream side in the conveying direction of the connecting portion is not provided. It can suppress the occurrence of sheet jam.

According to the invention of the third aspect of the invention, when the sheet is stopped, the sheet can be prevented from being sandwiched between the third conveyance roller and the counter roller.

According to the invention of the fourth aspect of the invention, in addition to the case where the sheet conveying device according to any one of the first to third inventions is not provided, In the rotation period other than when it is necessary to stop the rotation direction, the frequency of stopping the rotation due to the instruction to stop the conveyance from the external device including the image reading unit is suppressed.

According to the invention of the fifth aspect of the invention, in the case of the image reading apparatus according to the fourth aspect of the invention, it is possible to suppress the rotation period other than when the driving means has to stop in order to change the rotation direction thereof. The frequency of the chance of stopping the rotation due to an instruction to stop the conveyance from the external device including the image reading unit.

(structure)

FIG. 1 is a schematic configuration diagram of an image forming apparatus 100 including a sheet conveying device 10 according to an embodiment of the present invention as seen from the front side. Here, the front side refers to a surface on which the user operates the image forming apparatus 100 by operating means such as a touch panel and an operation key. On the other hand, the back side refers to a surface that is opposite to the front side. An XYZ rectangular coordinate system is set in the image forming apparatus 100. Here, when the image forming apparatus 100 is viewed from the front side, the side in the width direction of the image forming apparatus 100 corresponds to the X axis, and the side in the depth direction of the image forming apparatus 100 corresponds to the Y axis. A straight line orthogonal to the X axis and the Y axis is defined as a Z axis. That is, the Z axis corresponds to a coordinate axis in the vertical direction with respect to a plane indicated by the X axis corresponding to the width direction and the Y axis corresponding to the depth direction.

The image forming apparatus 100 mainly includes a sheet conveying device 10 and a paper feeding unit 20, The image forming unit 30 and the image reading unit 40 are configured. The sheet conveying device 10 is a paper conveying device that conveys paper that has been read as a document to a reading position of the image reading unit 40 and discharges the paper after the image is read. Paper is an example of the sheet of the present invention. The paper feed unit 20 supplies the paper to the image forming position of the image forming unit 30. The image forming unit 30 forms an image on the sheet fed by the paper feed unit 20 after each step of an electrophotographic method such as charging, exposure, development, transfer, and fixing. In the present embodiment, the image forming unit 30 is a means for forming a color image, but may be a means for forming a monochrome image. The image reading unit 40 reads an image formed on the sheet conveyed to the reading position in the sheet conveying device 10, and supplies the reading result to a control unit (not shown). The control unit supplies the reading result to the image forming unit 30 as necessary, and the image forming unit 30 forms an image corresponding to the supplied reading result on the sheet. The image reading unit 40 is an example of the image reading means of the present invention. Further, a device including at least the sheet conveying device 10 and the image reading unit 40 is an example of the image reading device of the present invention.

The sheet conveying device 10 includes a document placing unit 11 , a discharge paper loading unit 12 , and a conveying unit 13 . The document placing unit 11 is a tray on which sheets to be read as originals are placed. The conveying unit 13 is composed of a plurality of rollers for conveying paper. The sheet conveying device 10 is detachably attached to the image reading unit 40 via an opening and closing mechanism (not shown). A slit glass 14 is embedded in a part of the surface of the sheet conveying device 10 that is in contact with the image reading unit 40. If When the paper is conveyed to the slit glass 14 by the conveyance unit 13, the image reading unit 40 passes through the slit glass 14 to read an image formed on the paper. The paper imaged by the image is discharged by the transport unit 13 to the discharge paper loading unit.

The paper feed unit 20 includes a paper storage unit 21 for accommodating paper sheets and a paper feed unit 22 that transports the paper sheets stored in the paper storage unit 21 to a plurality of image forming positions of the image forming unit 30. Made up of rollers.

The image forming unit 30 forms an image using toners of four colors of yellow (Y), magenta (M), cyan (C), and black (K) by a so-called intermediate transfer method. The image forming unit 30 includes a photoreceptor drum 31, a charger 32, an exposure device 33, a developing device 34, toner cartridges 35Y, 35M (magenta), 35C (cyan), 35K, an intermediate transfer belt 36, and Fixing device 37. Further, among the constituent elements shown in FIG. 1, a letter (Y, M, C or K) is attached to the end of the component symbol, indicating that the constituent element corresponds to one of the above four colors. These constituent elements have the same main structure and function although the colors of the toners used are different. Therefore, in the following description of these constituent elements, when it is not necessary to distinguish colors, the end of the component symbol is omitted, and these are collectively referred to as "toner cartridge 35".

The photoreceptor drum 31 is a cylindrical member in which a photoconductive film is laminated on the surface and rotated about the axis, and is an image holder that holds an electrostatic latent image formed on the surface. The charger 32 causes the photoreceptor drum 31 to have a predetermined charged potential. The exposure device 33 exposes the photoreceptor drum 31 to form an electrostatic latent image. The developing device 34 develops the electrostatic latent image by supplying the toner to the electrostatic latent image An image is formed on the surface of the photoreceptor drum 31. The toner cartridge 35 accommodates toner of various colors and supplies it to the developing device 33 as needed. The intermediate transfer belt 36 is a means for holding the toner image transferred from the photoreceptor drum 31. The intermediate transfer belt 36 is supported by a plurality of support rollers and moves around one side in the direction indicated by an arrow A1 in the drawing. The fixing device 37 fixes the image on the sheet by heating and pressurizing the sheet on which the image is transferred from the intermediate transfer belt 34. The photoreceptor drum 31, the charger 32, the exposure device 33, the developing device 34, the intermediate transfer belt 36, and the fixing device 37 function as an example of the image forming means of the present invention by the cooperation.

FIG. 2 is a block diagram showing a hardware configuration of the sheet conveying device 10 and the main body of the image forming apparatus 100. The sheet conveying device 10 includes a control unit 101, a storage unit 102, and a communication unit 103. Each department is electrically connected by a bus bar. The control unit 101 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a time measuring unit for measuring time. The CPU controls each unit connected to the control unit 101 by executing a control program stored in the ROM or the storage unit 102. The control unit 101 is an example of the control means of the present invention. The storage unit 102 is a storage device such as a flash memory for storing, for example, a control program. The communication unit 103 communicates with the communication unit 183 of the main body of the image forming apparatus 100 under the control of the control unit 101.

The image forming apparatus 100 includes a control unit 181, a storage unit 182, a communication unit 183, a UI unit 184, and an image forming unit 30. Each part is connected by a bus bar. The control unit 181 has a CPU, a ROM, and a RAM. The CPU controls each unit connected to the control unit 181 by executing a control program stored in the ROM or the storage unit 182. The storage unit 182 is a storage device such as a hard disk for storing, for example, a control program and image data. Under the control of the control unit 181, the communication unit 183 communicates with the communication unit 103 of the sheet conveying device 10 and the communication terminal operated by the user. The UI (User Interface) unit 184 includes, for example, a touch panel or a plurality of buttons, and notifies the control unit 181 of an instruction based on the user's operation. The control unit 181 performs processing in accordance with an instruction notified by the UI unit 184. The image forming unit 30 forms an image based on image data on paper as described above.

FIG. 3 is an enlarged view of the conveying unit 13 in the sheet conveying device 10 from the front side. The transport unit 13 includes a paper pull-in roller 111, a paper reading sensor 112, a feed roller 113, a pull-out transport roller 114, a paper passing sensor 116, a resist roller 117, and an image reading timing sensor 119. The output roller 121, the paper passing sensor 123, the discharge roller 125, the sdenoid 127, the plurality of driven rollers 115, 118, 122, 126, the normal transport path 130, the connecting transport path 131, and the reverse The transport path 132, the upper transport guide 135, and the lower transport guide 136. The conveying unit 13 has a driving mechanism (not shown in Fig. 3) for driving the rollers in addition to the plurality of rollers shown in Fig. 2 . However, for convenience of explanation, first, the main part of the conveying unit 13 and the description of each roller are performed, and then Then explain the drive mechanism.

In the normal transport path 130, in FIG. 3, the paper is pulled from the paper, and the paper is fed through the feed roller 113, the pull-out transport roller 114, the resist roller 117, the slit glass 14, the output roller 121, and the discharge roller 125. The path when transporting to the position of each roller. On the other hand, the connection conveyance path 131 is connected to the connection portion L1 (an example of the first position) from the normal conveyance path 130 and the connection conveyance path 131 in the vicinity of the discharge roller 125, and to the pull-out conveyance roller 114. A path of the adjacent normal transport path 130 and the connection portion L2 (an example of the second position) of the connection transport path 131. In the normal conveyance path 130, the connection portion L2 is located on the upstream side of the paper conveyance direction from the connection portion L1. The reverse conveyance path 132 is a portion that is located downstream of the connection portion L2 in the paper conveyance direction in the normal conveyance path 130, and the conveyance direction of the paper is reversed in the reverse conveyance path 132. In the following description, when it is simply referred to as "paper conveyance direction", it means a direction in which the paper is conveyed toward the discharge roller 125 on the normal conveyance path 130.

The sheet conveying device 10 of the present embodiment is a double-sided reader. In the conveyance unit 13, the control unit 101 rotates the drive source of the drive mechanism in the normal rotation direction, and temporarily transports the paper to the position of the discharge roller 125 on the reverse conveyance path 132 via the normal conveyance path 130, and then By rotating the drive source in the reverse direction, the paper is returned to the normal conveyance path 130 again via the connection conveyance path 131. When the paper is transported to the position where the transport roller 114 is pulled out on the transport path 131, the control unit 101 drives the drive mechanism. The direction of rotation of the source becomes the forward direction. Then, the paper is conveyed on the normal conveyance path 130 and reaches the position of the discharge roller 125 again. At this time, the paper has a surface on the upper surface, and if the paper discharged in this state is placed on the discharge paper loading portion 12, the arrangement order of the papers is opposite to that before the conveyance. Therefore, in order to discharge the paper surface as a lower surface, the control unit 101 causes the rotation direction of the drive source of the drive mechanism to be reversed again, thereby transporting the paper on the connection transport path 131. Then, the paper is conveyed on the normal conveyance path 130, and when the surface reaches the lower state, the paper conveys to the discharge paper placement unit 12 by the discharge roller 125. By combining the normal transport path 130 and the reverse transport path 132, it can function as an example of the first transport path of the present invention. In addition, the connection transport path 131 is an example of the second transport path of the present invention.

The paper pull-in roller 111 is located on the normal conveyance path 130 at the most upstream of the paper conveyance direction. The paper pull-in roller 111 is rotated by the rotation of the feed roller 113 by the belt that is stretched between the feed roller 113 and the feed roller 113, and the paper placed on the document placing portion 11 is pulled into the inside of the transport unit 13. . The feed roller 113 is located on the upstream side of the paper conveyance direction of the connection portion L2 on the normal conveyance path 130, and conveys the paper by the rotation of the driving force generated by the drive source. An electromagnetic clutch to be described later is connected to the feed roller 113, whereby the electromagnetic clutch controls the transmission of the driving force from the drive source. Hereinafter, as the electromagnetic clutch, the state in which the electromagnetic clutch is driven on the non-driving side by the on/off control of the electromagnet is referred to as the electromagnetic clutch being connected. On the other hand, the state in which the driving side of the electromagnetic clutch is not connected to the non-driving side is referred to as a state in which the electromagnetic clutch is not connected. That is, when the electromagnetic clutch is not connected, the feed roller 113 does not rotate. Further, the position of the feed roller 113 is a supply position of the supply paper.

The paper reading sensor 112 is disposed between the paper pull-in roller 111 and the feed roller 113 on the normal transport path 130. If paper is detected at this position, the fact that the paper is detected is notified to the control unit 101. . Upon receiving this notification, the control unit 101 causes the electromagnetic clutch connected to the feed roller 113 to be in a connected state to transport the paper.

The pull-out conveyance roller 114 is located at the portion of the connection portion L2, and is rotated by the driving force generated by the drive source to convey the paper. A separate electromagnetic clutch different from the electromagnetic clutch connected to the feed roller 113 is connected to the pull-out conveyance roller 114, whereby the electromagnetic clutch controls the transmission of the driving force from the drive source. That is, when the electromagnetic clutch is in the non-connected state, the pull-out conveyance roller 114 does not rotate. The pull-out conveyance roller 114 is an example of the 1st conveyance roller of this invention. The driven roller 115 rotates in accordance with the rotation of the pull-out conveyance roller 114 to convey the paper. The paper passing sensor 116 is located on the normal transport path 130 on the upstream side of the paper transport direction of the pull-out transport roller 114 and the driven roller 115. If the paper passes the position, the detected fact is notified. The control unit 101 is provided. When the control unit 101 receives the notification, the electromagnetic clutch connected to the pull-out conveyance roller 114 is brought into a connected state when the time counted by the timer unit has elapsed for a predetermined period of time. Thereby pulling out and transporting The roller 114 rotates, and the driven roller 115 rotates to convey the paper. The predetermined time is the approximate time that the paper passing through the position of the paper passing sensor 116 abuts the pull-out conveyance roller 114 until the position of the leading end of the paper in the width direction is aligned with the position of the pull-out conveyance roller 114. time.

The resist roller 117 is located on the downstream side of the paper conveying direction of the connecting portion 137, and is rotated by the driving force generated by the driving source on the upstream side of the discharge roller 125 in the sheet conveying direction. The driven roller 118 rotates in conjunction with the rotation of the resist roller 117 to convey the paper. The resist roller 117 conveys the paper in a state in which the paper is held between the driven roller 118, and conveys the paper to the slit glass 14 at a predetermined timing, and is read by the image reading unit 40. An image formed on paper. The resist roller 117 is an example of the third transport roller of the present invention. Moreover, the driven roller 118 is an example of the opposing roller which opposes a 3rd conveyance roller of this invention. Further, the position of the slit glass 14 is a reading position at which an image of the paper can be read by the image reading unit 40.

The image reading timing sensor 119 is located on the downstream side of the sheet conveying direction of the blocking roller 117 and the driven roller 118 on the normal conveying path 130. If the leading end of the sheet is detected, the fact is notified to the control. Part 101. The control unit 101 receives this notification and controls the manner in which the driving by the driving means is stopped until the image reading unit 40 becomes a time at which the image can be read. As a result, since the resist roller 117 does not rotate during this driving stop period, the paper is not conveyed and is positioned on the slit glass 14. The control unit 101 receives the communication unit 183 from the communication unit 183 of the main body of the image forming apparatus 100. The notification of the readable timing is controlled in such a manner that the drive generated by the driving means starts again. As a result, the image formed on the sheet is read by the image reading unit 40 by the sheet slit glass 14 conveyed by the resist roller 117 and the driven roller 118.

The output roller 121 is for conveying paper that has finished image reading. The driven roller 122 rotates in accordance with the rotation of the output roller 121, and conveys the paper. The paper passing sensor 123 is located on the normal transport path 130 on the downstream side of the paper transport direction by the output roller 121 and the driven roller 122, and is a timing for determining the rotation direction of the driving force of the drive source to be the reverse direction. Sensor. If the paper passes the sensor 123 to detect that the trailing end of the sheet passes the position, the fact is notified to the control unit 101. After receiving the notification, the control unit 101 controls the timing of the driving force of the driving mechanism to be the reverse direction when the timing of the timer unit is only a predetermined time. At this time, one end portion of the paper is located at the position of the discharge roller 125, and is located on the reverse conveyance path 132.

In order to move the sheet conveyed on the normal conveyance path 130 toward the discharge roller 125, the normal conveyance path 130 must communicate with the position of the discharge roller 125. Downstream of the output roller 121, a press bar 124 is provided in the vicinity of the normal transport path 130 side of the connection portion L2. In a state where no physical force is applied, the press bar 124 hangs down due to its own weight, and the portion where the normal transport path 130 is connected to the reverse transport path 132 is closed at the connection portion L2. If the paper conveyed on the normal transport path 130 reaches the pressing rod 124, the pressing rod 124 It will become the state of pushing up from the paper. Then, when the paper passes, the presser bar 124 is lowered by its own weight, and the path from the connection portion L2 toward the normal conveyance path 130 is blocked, and the paper conveyed backward is moved toward the connection conveyance path 131.

The discharge roller 125 is located on the downstream side of the paper conveyance direction on the normal conveyance path 130, and is located on the reverse conveyance path 132, and is rotated by the driving force generated by the drive source to convey the paper. When the discharge roller 125 rotates in the normal rotation direction, the paper that has been read on both sides of the image that has been completed by the image reading unit 40 is discharged to the discharge paper loading portion 12, and when rotated in the reverse direction, The paper is conveyed toward the connection transport path 131. Further, in the paper on which the image is read on both sides of the unfinished image, the discharge roller 125 causes the rotation direction of the driving force to be reversed in the reverse direction, and the paper is conveyed along the connecting path 131. The discharge roller 125 is an example of the second conveyance roller of the present invention. Further, the position at which the discharge roller 125 is located is the discharge position at which the paper is discharged. The driven roller 126 rotates in accordance with the rotation of the discharge roller 125 to convey the paper. The solenoid 127, more specifically, a solenoid actuator, for example, is obtained by spirally winding a coil around the outer circumference of a metal core. The solenoid 127 moves the metal core up and down by flowing an electric current. The solenoid 127 is disposed at a position where the driven roller 126 is lifted when the metal core thereof moves up and down. When the paper is conveyed along the transport path 131 and the leading end of the paper reaches the position where the transport roller 114 is pulled out, the control unit 101 causes a current to flow through the solenoid 127, thereby lifting the driven roller 126 upward. The discharge roller 125 and the driven roller 126 are separated. Thereby, the pull-out conveyance roller 114 and the discharge roller 125 that rotate in opposite directions are not pulled in the opposite direction, and the paper is not caught in the position of the discharge roller 125 and the driven roller 126, since it acts at this position. The resistance on the paper is reduced, so that the paper can be smoothly conveyed by the pull-out conveyance roller 114.

The upper conveyance guide 135 and the lower conveyance guide 136 are guide members that guide the conveyance direction of the paper along the normal conveyance path 130. When the paper is conveyed, it reaches the upper conveyance guide 135 and the lower conveyance guide 136, and is guided in the forward direction. The upper conveyance guide 135 is located on the upper side of the lower conveyance guide 136 in the vertical direction. Further, as shown in the figure, the lower conveyance guide 136 guides the conveyance of the paper along the normal conveyance path 130 on the upstream side of the upper conveyance guide 135 in the sheet conveyance direction. The upper conveyance guide 135 and the lower conveyance guide 136 are coupled to each other by a connection portion 137 at a position where the end portions on the far side from the discharge roller 125 are in contact with each other. The connecting portion 137 is located on the downstream side of the sheet conveying direction of the pull-out conveying roller 114 on the normal conveying path 130.

4 is a perspective view of the upper conveyance guide 135 and the lower conveyance guide 136 as seen from the front side. The upper conveyance guide 135 and the lower conveyance guide 136 have a serrated shape on the end portion close to the connection portion 137 side. In a state in which the teeth are engaged with each other, the rotation shaft penetrates the center position of the coupling portion 137 in the depth direction. Thereby, the upper conveyance guide 135 can rotate in the direction away from the lower conveyance guide 136 centering on the rotation axis of the connection part 137. For example, if a jam occurs in the sheet conveying device 10, the user causes the upper conveying guide 135. The paper is rotated away from the lower conveyance guide 136, and the jammed paper is removed from the sheet conveyance device 10 in an opened state. The upper conveyance guide 135 is an example of the second guide member of the present invention. The lower conveyance guide 136 is an example of the first guide member of the present invention. Next, the drive mechanism will be described.

Fig. 5 is a schematic enlarged plan view showing the drive mechanism of the conveying unit 13 from the front side. In FIG. 5, in order to show the position of each member in the depth direction, a step is provided in the depth, and the members located at the depth positions of the respective stages are respectively indicated by lines of different shapes. First, the member located on the innermost side when the conveying unit 13 is viewed from the front side is indicated by a solid line. Further, a member which is located more outward than the member indicated by the solid line in the direction of the abutting direction is indicated by a broken line. Further, a member which is located one step further toward the outer side of the paper surface is indicated by a chain line. Further, a two-dot chain line indicates a member which is located one step further toward the paper surface than the member indicated by the one-dot chain line. The members of the drive mechanism represented by the differently shaped wires are located closer to the back side than the respective rollers. Further, each roller is indicated by a solid line thicker than the member of the drive mechanism. Further, for convenience of explanation, the description of the portions already explained in FIG. 3 will be omitted.

The conveyance unit 13 includes a motor 140, a large diameter gear 141, a small diameter gear 142, gears 144, 145, 146, 147, and 160, electromagnetic clutches 143 and 148, a fixed direction rotation mechanism 149, and a belt 161. Further, the motor 140 shown in the drawing actually represents a gear that is directly coupled to the drive shaft of the motor. The gear 144 is coupled to the rotating shaft of the discharge roller 125, and the gear 147 The electromagnetic clutch 148 is connected to the rotating shaft of the pull-out conveying roller 114, and is connected to the rotating shaft of the feed roller 113. The gears 144, 147 and the electromagnetic clutch 148 transmit the driving force generated by the motor 140 to the connected rollers. The large diameter gear 141 and the small diameter gear 142 have the same rotation axis, for example, a double gear. Further, the electromagnetic clutch 143 and the gear 145 have the same rotating shaft, for example, a double-layer gear. The electromagnetic clutches 143 and 148 have gears that are connected/separated from the drive side by the action of the electromagnet. This gear becomes engaged with each gear.

The motor 140 is selectively rotatable in the normal rotation direction and the reverse direction opposite to the normal rotation direction to generate a driving force. The motor 140 is an example of a driving means of the present invention. Further, the forward rotation direction is an example of the first direction of the present invention, and the reverse rotation direction is an example of the second direction of the present invention. Here, the case where the motor 140 rotates in the normal rotation direction will be described as an example, and the transmission of the driving force between the respective rollers and the gears will be described. When the motor 140 rotates in the normal rotation direction, the gear directly coupled to the drive shaft of the motor 140 rotates in the direction of the arrow R1 shown in the figure. Thereby, the large-diameter gear 141 that meshes with the gear of the motor 140 rotates in the direction of the arrow R2, and accordingly, the small-diameter gear 142 also rotates in the same direction, that is, in the R3 direction. The small diameter gear 142 meshes with the gear 144. Thereby, the gear 144 is rotated in the direction of the arrow R4. The gear 144 transmits the driving force to the discharge roller 125, whereby the discharge roller 125 is rotated in the direction in which the sheet is discharged.

In addition, the small diameter gear 142 meshes with the gear of the electromagnetic clutch 143. Thereby, the drive side gear of the electromagnetic clutch 143 is rotated in the direction of the arrow R5. The electromagnetic clutch 143 controls the transmission of the driving force to the gear 145. That is, everywhere When the driving side gear of the electromagnetic clutch 143 is separated from the driven side (ie, the non-connected state), the driving force is not transmitted to the gear 145, and on the other hand, the driving side gear of the electromagnetic clutch 143 is connected to the driven side. In the state (ie, the connected state), the driving force is transmitted to the gear 145, and the gear 145 is rotated in the direction of the arrow R6. Gear 145 meshes with gear 146, which meshes with gear 147. Thereby, the gear 146 is rotated in the direction of the arrow R7, and the gear 147 is rotated in the direction of the arrow R8 shown. The gear 147 transmits the driving force to the feed roller 113, and the feed roller 113 rotates in the direction in which the sheet is conveyed. That is, the electromagnetic clutch 143 switches between a state in which the driving force is transmitted from the motor 140 to the feed roller 113 and a state in which the transmission is not performed.

The electromagnetic clutch 148 controls the transmission of the driving force transmitted from the fixed-direction rotating mechanism 149 to the pull-out conveying roller 114. That is, when the electromagnetic clutch 148 is in the non-connected state, the driving force is not transmitted to the pull-out conveyance roller 114. On the other hand, when the electromagnetic clutch 148 is in the connected state, the driving force is transmitted to the pull-out conveyance roller 114, and the pull-out conveyance roller 114 rotates in the direction in which the sheet is conveyed. That is, the electromagnetic clutch 148 switches the state in which the driving force is transmitted from the motor 140 to the pull-out conveyance roller 114 and the state in which the transmission is not performed. The fixed-direction rotating mechanism 149 is a mechanism for rotating the electromagnetic clutch 148 and the pull-out conveying roller 114 having the same rotating shaft as the electromagnetic clutch 148 in the fixed direction by the planetary gear mechanism. A belt 161 is placed on the gear 160, the resist roller 117, and the output roller 121. Thereby, the driving force is transmitted from the gear 160 to the resist roller 117 and the output roller 121. Next, the fixed direction rotating mechanism 149 Be explained.

FIG. 6 is a perspective view of the fixed direction rotation mechanism 149 and the electromagnetic drive (drive side gear) 148 as seen from the back side of the sheet conveying device 10. The fixed-direction rotating mechanism 149 is composed of an internal gear 150, a sun gear 151, a planetary gear holder 152, and planetary gears 153, 154, and 155. The internal gear 150 is a disk-shaped member and has a gear on the outer peripheral side. In FIG. 6, for convenience of explanation, the shape of the gear is omitted and drawn as a circle. This is also the same for the sun gear 151. A sun gear 151 is provided on the same rotating shaft as the internal gear 150. That is, the internal gear 150 and the sun gear 151 constitute a double-layer gear. On the outer circumference of the sun gear 151, a planetary gear holder 152 which is a groove in which the rotation shafts of the planetary gears 153 and 154 are fitted is cut in a circular shape. When the sun gear 151 rotates, the planetary gears 153 and 154 rotate around the respective rotation axes by meshing with the sun gear 151, and move circumferentially around the planetary gear holder 152 around the sun gear 151.

For example, the sun gear 151 is rotated in the direction of the arrow L1a. In this case, the planetary gear 153 rotates in the L2a direction and performs a circular motion in the direction approaching the electromagnetic clutch 148. Moreover, since the gears of the planetary gear 153 and the electromagnetic clutch 148 are meshed, the electromagnetic clutch 148 is rotated in the direction of the arrow L3a. On the other hand, the sun gear 151 is rotated in the direction opposite to the arrow L1a, that is, in the direction of L1b. In this case, the planetary gear 154 rotates in the L2b direction and performs a circular motion toward the planetary gear 155. Moreover, since the planetary gear 154 and the planetary gear 155 are meshed, This planetary gear 155 rotates in the direction of the arrow L3b. Moreover, since the gears of the planetary gear 155 and the electromagnetic clutch 148 are meshed, the electromagnetic clutch 148 is rotated in the direction of the arrow L4b. As described above, since the arrow L3a and the arrow L4b indicate the same rotation direction, in the fixed direction rotation mechanism 149, the (the drive side gear) 148 of the electromagnetic clutch always rotates in the fixed direction regardless of the direction in which the sun gear 151 rotates. Thereby, the fixed-direction rotation mechanism 149 rotates the pull-out conveyance roller 114 on the normal conveyance path 130 in the rotation direction of the position where the paper is conveyed from the position of the connection part L2 to the connection part L1. The fixed direction rotation mechanism 149 is an example of the rotation mechanism of the present invention.

(action)

Next, the operation of the sheet conveying device 10 will be described. 7 and 8 are schematic views for explaining the operation of the sheet conveying device 10. In FIGS. 7 and 8, a schematic diagram in which the sheet conveying apparatus 10 is enlarged from the front side is assigned a serial number in an ascending order according to the timing of the operation. Hereinafter, for example, the map assigned in FIG. 7 and having the number "1" is referred to as No. 1 of FIG. If the flow from the start of the conveyance of the paper and the double-sided reading is performed, the flow is sequentially shown, and it becomes the No. 1 of FIG. 7, No. 2 of FIG. 7, No. 3 of FIG. 7, and No. 4 of FIG. No. 5 of Fig. 8, No. 6 of Fig. 8, No. 3 of Fig. 7, No. 4 of Fig. 7, No. 5 of Fig. 8, No. 6 of Fig. 8, No. 7 of Fig. 8, and No. 8 of Fig. 8. The reason for repeating No. 3 of Fig. 7, No. 4 of Fig. 7, No. 5 of Fig. 8, and No. 6 of Fig. 8 is as described above in order to adjust the order of the discharged sheets to be the same as before. Correct The drawings relating to these operations are not described repeatedly. In addition, in FIGS. 7 and 8, the rotation direction of each roller is indicated by an arrow. A roller that does not indicate the direction of rotation by an arrow indicates a driven roller or a roller that is not driven at the time.

No. 1 in Fig. 7 indicates a case where the sheet P1 is pulled in and the conveyance is started. First, if the paper reading sensor 112 detects the leading end of the sheet P1, it notifies the control unit 101 of the fact. Upon receiving the notification, the control unit 101 causes the electromagnetic clutch 143 to be in the connected state when the timing unit has notified that the predetermined time has elapsed. Thereby, the driving force generated by the rotation of the motor 140 in the normal rotation direction is transmitted to the large diameter gear 141, the small diameter gear 142, the electromagnetic clutch 143, the gear 145, the gear 146, and the gear 147, and the feed roller 113 is shown in the figure. The direction of the arrow rotates. Along with this, the paper pull-in roller 111 connected by the feed roller 113 and the pulley also rotates in the direction of the arrow shown. Further, at this time, the driving force generated by the forward rotation of the motor 140 is transmitted to the large diameter gear 141, the small diameter gear 142, and the gear 144, and the discharge roller 125 is rotated in the direction of the arrow shown. Further, at this time, the driving force generated by the rotation of the motor 140 in the normal rotation direction is transmitted to the internal gear 150 and the sun gear 151, and further transmitted from the gear 160 to the resist roller 117 and the output roller 121 on which the belt 160 is placed. Thereby, the resist roller 117 and the output roller 121 are rotated in the direction of the arrow shown. Further, at this time, since the electromagnetic clutch 148 is in the non-connected state, the driving force generated by the rotation of the motor 140 is not transmitted, and the pull-out conveying roller 114 does not rotate.

No. 2 of FIG. 7 shows a case where the paper P1 is conveyed by the pull-out conveyance roller 114. If the paper detects the leading end of the sheet P1 by the sensor 116, the fact is notified to the control unit 101. Upon receiving the notification, the control unit 101 causes the electromagnetic clutch 148 to be in a connected state and the electromagnetic clutch 143 to be in a disconnected state when the time counted by the timer unit is only a predetermined time. As a result, since the driving force is not transmitted, the feed roller 113 stops its rotation. Further, along with this, the paper pull-in roller 111 also stops its rotation. On the other hand, since the electromagnetic clutch 148 is in the connected state, the driving force is transmitted by the fixed-direction rotating mechanism 149, and the pull-out conveying roller 114 is rotated in the direction of the arrow shown. Here, the control unit 101 counts the number of times the electromagnetic clutch 148 is in the connected state as the variable C, and stores it in the RAM. The initial value of the variable C is zero. In order to read both sides of the paper and discharge the surface as the lower surface, the same paper must be conveyed three times at the position where the conveyance roller 114 is pulled out, that is, the surface reading conveyance, the back surface reading conveyance, and the inside and outside reversal. Use to transfer. Since the value of the variable C is "3", only the paper currently being conveyed has been ejected, so that the next sheet can be transported. When the transfer of the next paper is started, the control unit 101 clears the variable C to the initial value. At the timing of No. 2 in Fig. 7, the value of the variable C is "1". If the paper passes the sensor 116 to detect the rear end of the sheet P1, the fact is notified to the control unit 101. Upon receiving the notification, the control unit 101 causes the electromagnetic clutch 148 to be in a non-connected state when the time counted by the timer unit has passed only a predetermined time.

No. 3 of FIG. 7 indicates that the image reading unit 40 reads the sheet formed on the sheet P1. The image shows the case where the leading end of the next sheet P2 abuts against the feed roller 113. When the sheet P1 is conveyed to the position of the resist roller 117 and the image reading timing sensor 119 detects the leading end of the sheet P1, the image reading timing sensor 119 notifies the control unit 101 of this fact. Upon receiving the notification, the control unit 101 temporarily stops the driving of the motor 140 until the image reading unit 40 receives the notification of the preparation for reading the completed image. When the control unit 101 receives the notification of the preparation for reading the completed image from the communication unit 183 of the image forming apparatus 100 main body, the control unit 101 restarts the driving of the motor 140. As a result, the paper P1 is conveyed again, and when it passes through the slit glass 14, the image reading unit 40 reads the image formed on the paper P1, and supplies the reading result to the control unit 181. The control section 181 stores the reading result in the RAM, and instructs the image forming section 30 to form an image of the reading result on the sheet as needed.

The sheet P1 passing through the slit glass 14 is conveyed by the output roller 121. In No. 3 of Fig. 7, since the leading end of the paper reaches the pressing rod 124, the pressing rod 124 is raised. Here, if the paper passes the sensor 123 to detect the trailing end of the sheet P1, the fact is notified to the control unit 101. After receiving the notification, the control unit 101 causes the rotation direction of the motor 140 to be the reverse direction when the time counted by the timer unit is only a predetermined time. This predetermined time is, for example, the time required from the end of the paper P1 detected by the paper passing sensor 123 until the rear end of the paper P1 is conveyed to the position of the discharge roller 125. The raised pressure bar 124 will accompany the passage of the paper due to its own weight. decline.

No. 4 of FIG. 7 indicates a case where the motor 140 rotates in the reverse rotation direction and the paper P1 is conveyed on the connection conveyance path 131. The paper P1 is conveyed by the discharge roller 125, and its leading end moves in the direction in which the conveyance roller 114 is pulled out.

No. 5 of FIG. 8 indicates a case where the paper P1 is transported on the connection transport path 131. If the paper detects the leading end of the sheet P1 by the sensor 116, the fact is notified to the control unit 101. Upon receiving the notification, the control unit 101 causes the electromagnetic clutch 148 to be in a connected state when the time counted by the timer unit has elapsed for a predetermined period of time. The control unit 101 increments the variable C, and as a result, the value of the variable C becomes "2". At this time, although the rotation direction of the motor 140 is the reverse rotation direction, the rotation direction of the electromagnetic clutch 148 is a fixed direction, that is, a normal rotation direction by the action of the fixed-direction rotation mechanism 149. Thereby, the pull-out conveyance roller 114 also rotates in the normal rotation direction, and conveys the paper P1.

No. 6 of Fig. 8 indicates a case where the motor 140 performs forward rotation again, and the solenoid 127 lifts the driven roller 126. When the electromagnetic clutch 148 is in the connected state, the control unit 101 controls the driven roller 126 by causing a current to flow through the solenoid 127 when the value of the variable C is "2" or "3". Was raised. Further, at this time, the control unit 101 changes the rotation direction of the motor 140 from the reverse direction to the forward rotation direction. At this time, although the rotation directions of the pull-out conveyance roller 114 and the discharge roller 125 are opposite directions, since the driven roller 126 is lifted, the paper sheets are released from each other in the opposite direction, and the discharge roller is released. The position of the 125 and the driven roller 126 is not sandwiched between the sheets, and the resistance is reduced, so that the sheet P1 is conveyed by the pull-out conveyance roller 114.

In the sixth embodiment of FIG. 8, when the control unit 101 changes the rotation direction of the motor 140 from the reverse rotation direction to the normal rotation direction, the motor 140 that has been reversed is rotated in the forward rotation direction after the rotation of the motor 140 is temporarily stopped. When the motor 140 stops rotating, the control unit 101 of the sheet conveying apparatus 10 communicates with the communication unit 183 of the image forming apparatus main body by the communication unit 103, and inquires of an instruction to start and stop the conveyance of the paper, and obtains an inquiry result. . The control unit 101 functions as an example of the acquisition means of the present invention. In the image forming apparatus 100, the portion including at least the image reading unit 40 other than the sheet conveying device 10 is an example of an external device including an image reading unit.

For example, in the image forming apparatus 100, when the processing speed of each unit of the main body of the image forming apparatus 100 is less than the processing speed of the sheet conveying apparatus 10 or the problem of paper jam or communication failure occurs, even if the paper is transported to The image reading position is highly probable. Therefore, when the problem occurs, the control unit 181 notifies the sheet conveying device 10 of the instruction to stop the conveyance of the paper by the communication unit 183 in response to the inquiry from the sheet conveying device 10. When the control unit 101 of the sheet conveying apparatus 10 receives the notification by the communication unit 103, the conveyance of the paper is stopped by stopping the rotation of the motor 140. When the above problem is resolved, the control unit 181 notifies the sheet conveying device 10 of the instruction to start the conveyance of the paper by the communication unit 183. When the control unit 101 receives the notification by the communication unit 103, the motor is caused. 140 rotates in the forward direction. Next, differences between the conventional example and the above-described inquiry timing of the present embodiment will be described.

FIG. 9 is a view showing a communication timing with the control unit 181 of the image forming apparatus 100 in a conventional example. In the case where the motor 140 is temporarily stopped in the reverse rotation direction, and the paper is rotated in the normal rotation direction and the paper is conveyed, the control unit 181 of the main body of the image forming apparatus 100 is provided in each of the steps of (a) and (b). Ask. Fig. 9(a) shows a case where the notification of the inquiry result is OK at the time of the first answer, and the OK indicates that the paper can be transported without causing a problem. In this case, the motor 140 maintains its state and continues to rotate in the forward direction. On the other hand, FIG. 9(b) shows a case where the return inquiry result is once notified of NG, and the NG represents an instruction to stop the conveyance of the paper due to a problem. In this case, the control unit 101 temporarily stops the rotation of the motor 140 until the notification of the OK is obtained. Thereby, the conveyance of the paper is also stopped. When the problem is resolved, the control unit 181 of the image forming apparatus 100 returns the notification of the OK to the sheet conveying unit 10 by the communication unit 183. Thereby, the control unit 101 rotates the motor 140 in the normal rotation direction, and restarts the conveyance of the paper.

In the conventional example, the control unit 181 of the image forming apparatus 100 is inquired at the timing when the paper is conveyed. Therefore, the paper being conveyed is temporarily stopped, and the conveyance is resumed after the problem is released. In the sheet conveying apparatus 10, when the conveyed paper is temporarily stopped, when the conveyance is resumed, the leading end of the paper may be caught in the conveyance path to cause a jam. Therefore, it is hoped that after the paper is transferred at the beginning, except for the minimum necessary Outside of the timing, the paper is not stopped. On the other hand, in this embodiment, it is performed as follows.

FIG. 10 is a view showing a timing of communication with the control unit 181 of the image forming apparatus 100 in the present embodiment. In either of FIGS. 10( a ) and 10 ( b ), the control unit 181 of the main body of the image forming apparatus 100 is inquired at the timing when the motor 140 stops rotating. Fig. 10(a) shows a case where the notification of the inquiry result is OK at the time of the first answer. In this case, the control unit 101 rotates the stopped motor 140 in the normal rotation direction. Thereby, the paper is conveyed again. On the other hand, FIG. 10(b) shows a case where the notification of the return inquiry result is once NG. In this case, since the motor 140 is stopped, the control unit 101 continues to wait until the notification of OK is obtained. When the problem is resolved, the control unit 181 of the image forming apparatus 100 returns the notification of the OK to the sheet conveying unit 10 by the communication unit 183. Thereby, the control unit 101 rotates the motor 140 in the normal rotation direction, and restarts the conveyance of the paper.

As described above, in the present embodiment, when the rotation direction of the motor 140 is changed from the reverse direction to the normal rotation direction, the timing of the rotation is temporarily stopped, and an instruction to start the conveyance and the conveyance stop is performed. Therefore, even if the conveyance stop is received. Since the motor 140 has stopped, the paper conveyance is not excessively stopped. Therefore, in addition to the timing of temporarily stopping the motor 140 in changing its rotation direction, it is difficult to perform the operation of restarting the conveyance of the paper after the conveyance of the paper, and thus paper jam is less likely to occur.

In addition, in No. 6 of FIG. 8, if the motor 140 rotates in the reverse direction In the meantime, when the leading end of the paper reaches the position where the conveyance roller 114 is pulled out, the control unit 101 temporarily stops the rotation of the motor 140 when the rotation direction of the motor 140 is changed from the reverse direction to the forward rotation direction, but the timing of the stop is stopped. Set as follows. That is, the paper is in contact with the pull-out conveyance roller 114, and the leading end of the paper is located on the downstream side of the paper conveyance direction of the joint portion 137 on the normal conveyance path 130, and is located closer to the paper conveyance direction than the barrier roller 117. When the range is on the upstream side, the control unit 101 stops the rotation of the motor 140. Hereinafter, this range is referred to as a stop area. When the paper passes the sensor 116 to detect the leading end of the sheet conveyed on the continuous transport path 131, the fact is notified to the control unit 101. Upon receiving the notification, the control unit 101 stops the driving of the motor 140 when the time counted by the timer unit has elapsed for a predetermined period of time. This predetermined time refers to the time required after the leading end of the paper is detected by the paper passing sensor 116 until the leading end of the paper is in the stop area, depending on the rotational speed of the motor 140 and the sense of passing from the paper. The distance from the detector 116 to the stop region is determined in advance.

Since the conveyance is stopped when the leading end of the paper is in the stop area, there are the following advantages. For example, the joint portion 137 is likely to be jammed at the portion where it is joined. When the leading end of the paper is placed on the upstream side of the paper conveying direction from the connecting portion 137, the paper is stopped. When the paper is conveyed again, the leading end of the paper is easily caught in the connecting portion 137 and jammed. Therefore, when the leading end of the sheet is located downstream of the connecting portion 137 in the sheet conveying direction, the rotation of the motor 140 is stopped, and jamming can be suppressed.

In addition, when the leading end of the paper is stopped downstream of the resist roller 117, the conveyance of the paper is stopped, and the paper is caught by the resist roller 117. For example, when a paper jam occurs, the user rotates the upper conveyance guide 135 in a direction away from the lower conveyance guide 136, and removes the paper after the sheet conveyance device 10 is opened, but if the paper is blocked The state in which the roller 117 is sandwiched causes trouble that the user needs to remove the paper sandwiched by the resist roller 117 by hand. On the other hand, when the leading end of the sheet is positioned upstream of the sheet roller 117 in the sheet conveying direction, the rotation of the motor 140 is stopped. Therefore, it is possible to prevent the sheet from being caught by the stopper roller 117. Further, at this time, the paper is sandwiched between the pull-out conveyance roller 114 and the driven roller 115 opposed to the pull-out conveyance roller 114, but the upper conveyance guide 135 is moved away from the lower conveyance guide 136. When the sheet conveying apparatus 10 is rotated and rotated, the drawing conveyance roller 114 and the driven roller 115 are separated, and the paper is not pinched.

Return to Figure 8 again. After the sixth in FIG. 8, the same operations as those described in No. 3 of FIG. 7, No. 4 of FIG. 7, No. 5 of FIG. 8, and No. 6 of FIG. 8 are performed again. When the operation of No. 5 of Fig. 8 is completed for the second time, the value of the variable C becomes "3". When the operation of No. 6 of Fig. 8 is performed for the second time, the value of the variable C is "3", and the next sheet can be transported. Therefore, after detecting the trailing end of the sheet P1 from the sheet passing sensor 116, the control unit 101 causes the electromagnetic clutch 148 to be in a non-connected state and the electromagnetic clutch 143 to be in a connected state after a predetermined time elapses. Thereby, the feed roller 113 and the paper pull-in roller 111 Rotate in the forward direction to transport the next paper P2. In this manner, the control unit 101 controls the conveyance timing of the paper by switching the transmission state of the driving force of the electromagnetic clutch 148 and the electromagnetic clutch 143. Further, the control unit 101 clears the value of the variable C to the initial value.

No. 7 of Fig. 8 indicates a case where the sheet P1 is in the middle of discharge, and the next sheet P2 is abutted against the feed roller 113. If the paper passes the sensor 116 to detect the leading end of the sheet P2, the fact is notified to the control unit 101. When the control unit 101 receives the notification, if the time counted by the timer unit passes a predetermined time, the electromagnetic clutch 148 is brought into a connected state, and the electromagnetic clutch 143 is brought into a non-connected state.

No. 8 of Fig. 8 shows a case where the sheet P1 is discharged and the next sheet P2 is conveyed. Since the electromagnetic clutch 148 is in the connected state, the pull-out conveyance roller 114 rotates in the direction of the arrow shown to convey the paper P2. The paper P1 is conveyed by the discharge conveyance roller 125, and is discharged to the discharge paper loading unit 12.

According to the present embodiment, the control unit 101 rotates the motor 140 in the normal rotation direction, and starts the conveyance of the first paper fed from the supply position, and after the first paper passes the position of the feed roller 113 on the normal conveyance path 130, The state in which the driving force is transmitted to the feed roller 113 is switched to a state in which the transfer is not performed by the electromagnetic coupler 143. Further, the control unit 101 switches the state in which the driving force is transmitted to the drawing conveyance roller 114 by the electromagnetic clutch 148 after the position where the first paper passes the position where the conveyance roller 114 is pulled out by the electromagnetic conveyance path 138, so that the transmission is not performed. status. In addition, if the normal transport path When the first paper is transported to the discharge roller 125 at 130, the control unit 101 rotates the motor 140 in the reverse direction to change the rotation direction of the discharge roller 125, and transports the first paper to the pull-out via the connection transport path 131. The position of the conveying roller 114. Further, the control unit 101 switches the state in which the driving force is transmitted to the pull-out conveyance roller to the state in which the transmission is not performed, and the control unit 101 stops the rotation of the motor 140. In the stop period of the motor 140, the control unit 101 inquires of the control unit 181 of the image forming apparatus 100 about the start of conveyance of the paper and the instruction to stop the conveyance. When an instruction to stop the conveyance of the paper is obtained as a result of the inquiry, the control unit 101 waits for the motor 140 to wait until an instruction to start the conveyance of the paper is obtained. On the other hand, when an instruction to start the conveyance of the paper is obtained as a result of the inquiry, the control unit 101 rotates the motor 140 in the normal rotation direction to change the rotation direction of the discharge roller 125. When the first paper passes the position where the transport roller 114 is pulled out, the control unit 101 switches the state in which the driving force is transmitted to the pull-out transport roller 114 to the state in which the transfer is not performed by the electromagnetic clutch 148. In the state in which the electromagnetic clutch 143 is not used to transmit the driving force to the feed roller 113, the conveyance of the second paper to be conveyed after the first paper is started. In the forward rotation period by the motor 140 until the position where the second paper is conveyed to the discharge roller 125 by the image, the first paper is conveyed by the discharge roller 125 and discharged.

According to this embodiment, it is provided with a selective forward direction and a reverse direction. In the sheet conveying device 10 of the motor 140 that rotates in the direction, when the motor 140 is stopped to change its rotation direction, an instruction to start the conveyance of the paper and stop the conveyance is obtained. Thereby, it is possible to suppress the frequency of the chance of stopping the rotation due to the conveyance stop instruction from the image forming apparatus 100 in the rotation period other than when the motor 140 has to be stopped in order to change its rotation direction. In addition, the timing at which the control unit 101 temporarily stops the rotation of the motor 140 by changing the rotation direction of the motor 140 from the reverse rotation direction to the normal rotation direction is such that the leading end of the paper is positioned on the upper conveyance guide 135 on the normal conveyance path 130 and When the connection portion 137 of the lower conveyance guide 136 is further on the downstream side in the sheet conveyance direction, it is possible to suppress jamming of the connection portion 137 at the leading end of the sheet when the conveyance of the sheet is resumed. In addition, the timing at which the control unit 101 temporarily stops the rotation of the motor 140 by changing the rotation direction of the motor 140 from the reverse rotation direction to the normal rotation direction is such that the leading end of the paper sheet is placed on the paper on the normal conveyance path 130. When the conveyance direction is on the upstream side, when the conveyance of the paper is stopped, the paper can be prevented from being caught between the barrier roller 117 and the driven roller 118. Thereby, when the user removes the paper jammed by the jam, the trouble of removing the paper jammed by the resist roller 117 by hand operation can be saved.

10‧‧‧Sheet conveying device

11‧‧‧Original Loading Department

12‧‧‧Discharge paper loading section

13‧‧‧Transportation Department

14‧‧‧Slit glass

20‧‧‧Feeding Department

21‧‧‧ Paper Storage Department

22‧‧‧Feeding means

30‧‧‧Image Formation Department

31‧‧‧Photoreceptor roller

32‧‧‧Electrical appliances

33‧‧‧Exposure device

34‧‧‧developer

35‧‧‧Toner card

36‧‧‧Intermediate transfer belt

37‧‧‧Fixing device

40‧‧‧Image Reading Department

100‧‧‧Image forming device

101‧‧‧Control Department

102‧‧‧ Storage Department

103‧‧‧Communication Department

111‧‧‧paper pull-in roller

112‧‧‧paper reading sensor

113‧‧‧feed rolls

114‧‧‧ Pull out the transport roller

115‧‧‧ driven roller

116‧‧‧paper passing sensor

117‧‧‧Barrier roller

118‧‧‧ driven roller

119‧‧‧Image reading timing sensor

121‧‧‧ Output Roller

122‧‧‧ driven roller

123‧‧‧paper passing sensor

124‧‧‧Press

125‧‧‧ discharge roller

126‧‧‧ driven roller

127‧‧‧ Solenoid

130‧‧‧Normal transport path

131‧‧‧Connected transport path

132‧‧‧Reverse transport path

135‧‧‧Upper transport guide

136‧‧‧Lower transport guide

137‧‧‧Connecting Department

140‧‧‧Motor

141‧‧‧ Large diameter gear

142‧‧‧ Small diameter gear

143‧‧‧Electromagnetic clutch

144‧‧‧ Gears

145‧‧‧ gears

146‧‧‧ Gears

147‧‧‧ Gears

148‧‧‧Electromagnetic clutch

149‧‧‧ Fixed direction rotating mechanism

150‧‧‧Internal gear

151‧‧‧Sun Gear

152‧‧‧ Planetary gear holder

153‧‧‧ planetary gear

154‧‧‧ planetary gear

155‧‧‧ planetary gear

160‧‧‧ gears

161‧‧‧ drive belt

181‧‧‧Control Department

182‧‧‧ Storage Department

183‧‧‧Communication Department

184‧‧‧U1

A1‧‧‧ arrow

L1, L2‧‧‧ joints

L1a, L1b, L2a, L2b, L3a, L3b, L4b‧‧‧ arrows

P1, P2‧‧‧ paper

R1~R8‧‧‧ arrow

X, Y, Z‧‧‧ axes

FIG. 1 is a schematic configuration view of an image forming apparatus including a sheet conveying device according to an embodiment of the present invention as seen from the front side.

Fig. 2 is a block diagram showing a hardware structure of a sheet conveying device.

3 is a schematic view showing an enlarged portion of a conveying unit of the sheet conveying device from the front side.

4 is a perspective view of the upper conveyance guide and the lower conveyance guide as seen from the front side.

Fig. 5 is a schematic view showing the drive mechanism in an enlarged manner from the front side.

Fig. 6 is a perspective view of the fixed-direction rotating mechanism and the electromagnetic clutch as seen from the back side of the sheet conveying device.

FIG. 7 is a schematic view for explaining the operation of the sheet conveying device.

FIG. 8 is a schematic view for explaining the operation of the sheet conveying device.

(a) and (b) of FIG. 9 are diagrams showing communication timings with a control unit of the image forming apparatus of the conventional example.

(a) and (b) of FIG. 10 are diagrams showing communication timings with a control unit of the image forming apparatus according to the embodiment.

14‧‧‧Slit glass

111‧‧‧paper pull-in roller

112‧‧‧paper reading sensor

113‧‧‧feed rolls

114‧‧‧ Pull out the transport roller

115‧‧‧ driven roller

116‧‧‧paper passing sensor

117‧‧‧Barrier roller

118‧‧‧ driven roller

119‧‧‧Image reading timing sensor

121‧‧‧ Output Roller

122‧‧‧ driven roller

123‧‧‧paper passing sensor

124‧‧‧Press

125‧‧‧ discharge roller

126‧‧‧ driven roller

127‧‧‧ Solenoid

130‧‧‧Normal transport path

131‧‧‧Connected transport path

132‧‧‧Reverse transport path

135‧‧‧Upper transport guide

136‧‧‧Lower transport guide

137‧‧‧Connecting Department

L1‧‧‧ connection site

L2‧‧‧ connection site

X‧‧‧ axis

Y‧‧‧ axis

Z‧‧‧ axis

Claims (9)

A sheet conveying device comprising: a first conveying path of a sheet, wherein a reading position of an image in which the sheet can be read by the image reading unit is started from a supply position of the supply sheet; The discharge position of the sheet is discharged; the second conveyance path of the sheet is from the first position to the second position on the first conveyance path, and the second position is the first position on the first conveyance path. The driving position is further located on the upstream side in the conveying direction of the sheet; the driving means selectively rotates in the first direction and the second direction to generate a driving force; and the first conveying roller is driven by the driving means at the second position. The generated driving force is rotated to convey the sheet, and the second conveying roller is generated by the driving means at a position on the downstream side of the first conveying position in the conveying direction on the first conveying path. The driving force rotates to convey the sheet; and the rotating mechanism conveys the sheet from the second position to the first position on the first conveying path regardless of a rotation direction of the driving means a first conveying roller that rotates in the rotation direction, and an obtaining means for obtaining an instruction to start and stop the conveyance of the sheet from an external device including the image reading unit, and a control means for controlling the driving means The above control means are: The driving means is rotated in the first direction to start the conveyance of the sheet supplied from the supply position, and the sheet is conveyed to the first conveyance path by the position of the first conveyance roller. When the position of the second conveyance roller is rotated in the second direction, the rotation direction of the second conveyance roller is changed, and the sheet is conveyed to the position of the first conveyance roller via the second conveyance path. When the drive means is stopped, the instruction to stop the conveyance of the sheet is obtained by the acquisition means, and the operation is waited until the instruction to start the conveyance of the sheet is obtained. When the instruction to start the conveyance of the sheet is obtained by the obtaining means, the driving means is rotated in the first direction to change the rotation direction of the second conveying roller, and after the sheet is passed through the position of the first conveying roller The second transfer roller is transported and discharged. The sheet conveying apparatus according to the first aspect of the invention, further comprising: a first guiding member that guides a conveying direction of the sheet along the first conveying path; and a second guiding member The conveying direction of the sheet is guided along the first conveying path on the upstream side of the first conveying member in the sheet conveying direction, and the connecting portion is configured such that the second guiding member can be moved away from the above The first guiding member and the second portion are configured to rotate in the direction of the first guiding member When the guide member is connected to the first conveyance roller and the tip end of the sheet is located on the first conveyance path on the downstream side of the connection portion in the conveyance direction, the driving is performed. The means stop. The sheet conveying apparatus according to the first or second aspect of the invention, wherein the third conveying roller is provided on the first conveying path, and is located downstream of the conveying direction in the conveying direction, and The rotating member is rotated by the driving force generated by the driving means on the upstream side in the transport direction from the second transporting roller, and the sheet is interposed between the third transporting roller and the opposing roller opposed thereto. In the state in which the sheet is conveyed, the sheet is in contact with the first conveyance roller, and the tip end of the sheet is located on the upstream side of the third conveyance roller in the conveyance direction on the first conveyance path. , the above driving means is stopped. An image reading apparatus comprising: a sheet conveying device according to claim 1; and an image reading device for reading a sheet from the sheet conveying device image. An image reading apparatus comprising: a sheet conveying device of the second application of the patent application; and an image reading means for reading a sheet from the sheet conveying device image. An image reading apparatus comprising: a sheet conveying device according to claim 3; and an image reading device for reading a sheet from the sheet conveying device image. An image forming apparatus comprising: an image reading apparatus according to item 4 of the patent application; and an image forming means for forming an image read by the image reading apparatus in a recording media. An image forming apparatus comprising: an image reading apparatus according to item 5 of the patent application; and an image forming means for forming an image read by the image reading apparatus in the recording media. An image forming apparatus comprising: an image reading device of claim 6; and an image forming means for forming an image read by the image reading device in a record media.