JPH089099Y2 - Sheet transport device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a copying machine for forming images on both sides of a sheet,
The present invention relates to an image forming apparatus such as a laser printer, a liquid crystal printer, and a printing machine, and a sheet conveying apparatus such as a sheet accommodating apparatus that reverses and accommodates a sheet supplied from the image forming apparatus.

[Conventional technology]

Generally, in an image forming apparatus such as a copying machine, when copying on both sides of a sheet, the sheet copied on one side is switched back and turned upside down, and then temporarily stored in an intermediate tray, and then the intermediate tray is transferred to the copying machine again. Double-sided copying is performed by feeding a sheet and making a copy on the opposite side that has not been copied.

In such a double-sided copying machine, a pair of forward / reverse rollers are used to switch back the sheet as in Japanese Patent Publication No. 61-1864, and when a sheet copied on one side is supplied to the switchback section. , Rotate the forward / reverse roller forward,
When the sheet supplied to the switchback unit is conveyed to the intermediate tray, the forward / reverse rotation roller is rotated in the reverse direction.

[Problems to be solved by the invention]

However, in order to rotate the forward / reverse rotation roller in the forward / reverse direction, the control becomes complicated, and it is difficult to obtain the driving force from another driving system. Further, since the peripheral surfaces of the pair of forward / reverse rotation rollers are in contact with each other, it is difficult for the sheet to enter between the forward / reverse rotation rollers.

[Purpose of device]

An object of the present invention is to obtain a sheet conveying apparatus in which a sheet easily enters a conveying direction changing path and sheet jamming is prevented.

[Example of device]

An embodiment of the present invention will be described below with reference to the drawings.

<Overall Configuration> As shown in FIG. 1, an image forming apparatus including a sheet take-in unit 3 and an image forming unit 5, such as a copying machine 7, is placed on a placing table 1 that accommodates a plurality of sheet feeding cassettes 9. A sheet storage device 99 is attached to the discharge port 97 of the copying machine 7. An automatic document feeder 75 is mounted on the copying machine 7.

<Structure of Copying Machine 7> The sheet taking-in section 3 of the copying machine 7 is provided with two taking-in ports 47 and 49. The paper feed cassette 9 is inserted into these take-in ports 47 and 49, and sheets are selectively taken in by the take-in rollers 51 and 53 provided inside. Then, the taken-in sheet is sent to the image forming section 5 by the registration roller 55 and the conveyance belt 57.

The image forming section 5 is provided with a photosensitive drum 59. Around the photosensitive drum 59, a charging device 61, an unnecessary charge eraser 63, a developing device 65, a transfer device 67, a separation charging device 69, a separation claw 71, and a drum cleaner 73 are arranged.

A platen 77 is provided below the automatic document feeder 75,
A slit illuminating device 79 is provided below it so as to be movable in the left-right direction along the platen 77.

An exposure optical device including two movable reflecting mirrors 81 and 83, a lens 85, and two fixed reflecting mirrors 87 and 89 forms an optical image of the original image illuminated by the slit illumination device 79 on the photosensitive drum 59. It is designed to be transmitted and exposed.

The photosensitive drum 59 forms an electrostatic latent image corresponding to the image of the original on its outer peripheral surface, and the latent image is visualized by toner by the developing device 65.

The visible image formed on the photosensitive drum 59 is taken in by the taking-in roller 51 or 53, the paper feed timing is adjusted by the registration roller 55, and the sheet P is sent between the photosensitive drum 59 and the transfer device 67. Is transcribed to.

The sheet on which the visible image is transferred in this way is discharged by the separation charging device 69 and separated by the separation claw.
It is separated from the photosensitive drum 59 by the mechanical separating action of 71, and is sent to the fixing device 93 by the conveying roller 91.

The transfer sheet is discharged from the discharge port 97 by the discharge roller 95 with the visible image facing upward, and is stored in the sheet storage device 99.

A paper discharge sensor 94 including, for example, a light emitting element and a light receiving element is provided near the discharge roller 95. The paper discharge sensor 94 is for confirming whether or not the sheet is discharged from the copying machine 7. When the object (sheet or the like) is detected for a predetermined time or longer, the sheet conveying operation is stopped.

<Structure of Automatic Document Feeding Device 75> The automatic document feeding device 75 includes a document tray 207, a separation feeding unit 209 that separates and feeds a document set on the document tray 207 into one sheet, and this separation feeding unit. A conveyance unit 211 that conveys the document sent from the unit 209 on the platen 77, and a reversal discharge unit 213 that reverses and ejects the document that has been copied.
And a storage tray 215 for storing the document discharged from the reverse discharge unit 213, so that the document can be automatically fed and discharged.

<Structure of Sheet Accommodating Device 99> In the sheet accommodating device 99, as shown in FIG. 2, a first conveyance path 101 formed by guides 11 and 12 for taking in the sheet discharged from the discharge port 97, and the conveyance path 101. The conveyance direction changing path 103 (switchback section) formed by the guides 13 and 14 for changing the conveyance direction of the sheet supplied to the sheet, and the sheet with the rear end of the sheet supplied to the conveyance direction changing path 103 as the leading end. A second transport path 105 formed by guides 14 and 15 for transporting the sheet, and a tray 107 for accommodating the reversed sheet discharged from the transport path 105 are provided. The guide 14 is the guide means of the present application.

Further, an optical sensor 109 for detecting passage of a sheet is provided in the conveyance path 101. This sensor 109
When the leading edge of the sheet is detected, the drive motor of the sheet storage device 99 is activated, and a predetermined time after the trailing edge of the sheet is detected (the trailing edge of the sheet passes through the pressure contact portion between the transport roller 111 and the elastic sheet 113. This is for exciting the solenoid 127 which will be described later).

At the branch portion of the first transport path 101 and the second transport path 105, the transport roller 111 is spread over both the transport paths 101 and 105.
(Rotating body) is provided.

An elastic sheet 113 (auxiliary conveying means) formed of a synthetic resin or the like is in contact with the conveying roller 111 on the first conveying path 101 side, and a driven roller 115 is in contact with the second conveying path 105 side. .

The elastic sheet 113 is attached to the guide 11, and together with the conveying roller 111, the first conveying path 101 to the conveying direction changing path 10
The sheet is fed to the sheet 3, and the trailing edge of the sheet is guided to the entrance side of the second conveyance path 105. This elastic sheet 113
The contact point between the transport roller 111 and the transport roller 111 is not located on the extension line of the transport path 101, and the trailing edge of the sheet discharged from the transport path 101 is not caught between the transport roller 111 and the driven roller 115. In addition, it is provided on the transport path 105 side.

The conveyance direction change path 103 is supplied to the conveyance direction change path 103 with a conveyance roller 117 (driving rotator) that rotates in a direction of sending the sheet supplied from the first conveyance path 101 to the second conveyance path 105. The sheet is brought into contact with the conveyance roller 117, and a pressing unit 119 for guiding the sheet to the entrance side of the second conveyance path 105 is provided.

The pressing unit 119 rotates about an elastically deformable elastic body 121 that guides the sheet supplied from the first conveying path 101 to the conveying direction changing path 103, and a shaft 123 that elastically deforms the elastic body 121. A lever 125, a solenoid 127 that drives this lever 125, and a driven roller 129 (driven rotor) that is attached to the shaft 123 via a leaf spring 128 and is brought into pressure contact with the transport roller 117 by excitation of the solenoid 127 are provided. There is.
The lever 125, the leaf spring 128, and the solenoid 127 are the driving means of the present application.

The elastic body 121 is attached to the guide 13 so as to be swingable about a position in a direction away from the first transport path 101 from a position where the transport roller 117 and the driven roller 129 face each other.

The second transport path 105 is provided with, for example, an optical sensor 131 that detects a sheet to be discharged, and discharge rollers 133 and 135 that discharge the sheet. The sensor 131 is for deenergizing the solenoid 127 when detecting the leading edge of the sheet, and for stopping the drive motor if the sensor 109 has not detected the next sheet after a predetermined time has elapsed after detecting the trailing edge. .

By the way, if the sensors 109 and 131 are not turned on within a predetermined time after they are turned on, a sheet jam occurs.

<Operation> With the above-mentioned configuration, this device operates as follows.

When the copy button is pressed, the document set on the document tray 207 of the automatic document feeder 75 is sent out onto the platen 77. This original is copied by the copying machine 7. This copied sheet is fed from the discharge port 97 of the copying machine 7 to the sheet storage device.
When the leading edge of the sheet is detected by the sensor 109 and the sensor 109 detects the leading edge of the sheet, the drive motor is activated to rotate the transport rollers 111 and 117 and the discharge roller 133 in one direction.

The sheet that has passed through the sensor 109 is gripped by the conveyance roller 111 and the elastic sheet 113, conveyed by the conveyance roller 111 while being guided to the guide 14 side by the elastic sheet 113, and sent to the conveyance direction changing path 103.

After a lapse of a predetermined time from the detection of the rear end of the sheet by the sensor 109, the solenoid 127 is excited. For this reason,
The lever 125 and the driven roller 129 rotate about the shaft 123,
The elastic body 121 is pushed by the lever 125 and the conveyance direction changing path 103
While pushing the upper end side of the sheet supplied to the guide 14,
The driven roller 129 is pressed against the conveyance roller 117 via the sheet.

Therefore, a conveying force is generated in the conveying roller 117, and the sheet sandwiched between the guide 14 and the elastic body 121 is changed in the conveying direction by the conveying roller 117 and the driven roller 129 and is raised. As a result, the trailing end of the sheet supplied to the transport direction changing path 103 is gripped by the transport roller 111 and the driven roller 115, and transported on the transport path 105. When the sensor 131 detects the leading edge of the sheet, the solenoid 127 is deenergized.

The sheet is discharged by the discharge rollers 133 and 135,
If the trailing edge of the sheet passes the sensor 131 and the sensor 109 does not detect the next sheet after a predetermined time, the drive motor is stopped.

By repeating such operations, the sheets are stored on the tray 107 in the page order.

According to this embodiment, a transport roller 111 is provided at a branch portion of the first transport path 101 and the second transport path 105 so as to straddle both the transport paths 101, 105, and the transport roller 111 has the first transport path 101. Since the elastic sheet 113 is contacted at a position closer to the second transport path 105 than on the extension line of the elastic sheet 113,
It is possible to feed the sheet from the first conveying path 101 to the conveying direction changing path 103 together with the conveying roller 111 and guide the trailing end of the sheet to the entrance side of the second conveying path 105.

Further, since the pressing means 119 for bringing the sheet supplied to the conveying direction changing path 103 into contact with the conveying roller 117 and moving the sheet to the entrance side of the second conveying path 105, the sheet is moved when the conveying direction of the sheet is changed. It is easy to guide to the second transport path 105.

Therefore, the transport roller 117 provided on the transport direction changing path 103
Even if there is no means for rotating the sheet supplied from the first conveyance path 101 to the second conveyance path 105 and taking the sheet into the conveyance direction changing path 103, the above-mentioned conveyance roller By the action of 111 and the elastic sheet 113, the trailing edge of the sheet from the first conveying path 101 is easily cut, and the movement of the sheet by the pressing means 119 prevents the sheet from jamming in the conveying direction changing path 103 when the conveying direction is changed. It becomes possible to convey to the second conveying path 105.

[Modification]

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and the following modifications can be made.

(1) The auxiliary conveying means may be the roller 137 in contact with the conveying roller 111 as shown in FIG.

(2) The auxiliary transporting means may be a rotating body 141 having a plurality of elastic pieces 139 contacting the transporting roller 111 as shown in FIG.
The use of this rotating body 141 has the effect of kicking out the rear end of the seat.

(3) In the above embodiment, the example in which the sheet conveying device of the present invention is applied to the sheet accommodating device is shown. However, an image forming device that forms an image on both sides of a sheet, or a plurality of sheets that are aligned and bound at one end, It can also be applied to a sheet processing apparatus that switches back to perform cutting.

(4) The transport rollers 111 and 117 that are rotating bodies are not limited to rollers, but may be belts or the like.

[Effect of device]

This invention is directed to the moving direction of a sheet in the transport direction changing path depending on when the sheet is supplied from the first transport path to the transport direction changing path and when the sheet is supplied from the transport direction changing path to the second transport path. , The drive rotator provided in the transport direction changing path rotates only in the direction in which the sheet supplied to the transport direction changing path is transported to the second transport path, and is provided to face the drive rotator. The driven rotating body is separated from the driving rotating body when the sheet is supplied from the first conveying path to the conveying direction changing path, and is moved from the conveying direction changing path to the second side.
When the sheet is conveyed to the conveyance path, the driving rotor is pressed against the rotating rotor through the sheet, so the control of the driving rotor is easy and the sheet conveying direction can be changed smoothly. it can.

Further, when the sheet is supplied to the conveyance direction changing path, the drive rotor rotates in the direction in which the sheet is prevented from entering. However, the drive rotor and the driven rotor are located at the first position from the position where the drive rotor and the driven rotor face each other. An elastic body is provided so as to be swingable around a position in the direction away from the transport path, and the first position and the second position are determined depending on whether the drive rotating body and the driven rotating body are separated from each other or are in pressure contact with each other. Since the sheet fed from the first conveying path is guided between the drive rotating body and the driven rotating body, the drive rotating body and the driven body are driven between the guide means and the elastic body. The sheet is opened in a V shape around the position in the direction away from the first transport path from the position facing the rotating body, and the movement of the sheet supplied from the first transport path is restricted by the elastic body. Instead, it can be inserted between the drive rotating body and the driven rotating body, and the sheet can be prevented from being jammed.

[Brief description of drawings]

1 and 2 are views showing an embodiment of the present invention. FIG. 1 is a sectional view showing the overall construction of a copying machine, an automatic document feeder, and a sheet storage device, and FIG. 2 is a sheet storage device. It is a cross-sectional view showing the structure of. 3 and 4 are views showing a modified example. 1 ... Mounting table 7 ... Copying machine 14 ... Guide (guide means) 75 ... Automatic document feeder 99 ... Sheet accommodating device 101 ... First conveying path 103 ... Conveying direction changing path 105 ... Second conveying path 111 ... Conveying roller 113 ... Elastic sheet 117 ... Conveying roller (driving body) 121 ... Elastic body 125 ... Lever (driving means) 127 ... Solenoid (driving means) 128 ... Leaf spring (driving means) 129 ... Driven roller (driven rotation body)

 ─────────────────────────────────────────────────── --- Continued from the front page (56) References JP-A-60-6550 (JP, A) JP-A-58-172154 (JP, A) JP-A-57-77154 (JP, A) JP-A 61- 162457 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A sheet is sent from a first conveying path to a conveying direction changing path and is conveyed along a second conveying path with the trailing end of the sheet supplied to this conveying direction changing path as the leading end. In the sheet conveying device, the sheet supplied to the conveying direction changing path is provided so as to contact the surface of the sheet supplied from the first conveying path to the conveying direction changing path on the side of the second conveying path. A drive rotating body that rotates in a direction in which the sheet is conveyed to the second conveying path, and a sheet that is provided so as to face the driving rotating body and that is fed from the first conveying path to the conveying direction changing path. When the sheet is conveyed from the conveying direction changing path to the second conveying path, the sheet is pressed against the driving rotating body that is rotating through the sheet, and is driven by the driving rotating body. Second A driven rotating body that rotates following the sheet conveyed in the conveying path direction, and a surface of the sheet supplied to the conveying direction changing path on the side of the driving rotor, and contact this sheet with the driving rotating body and the driven rotation. Guide means for guiding the sheet conveyed to the second conveyance path by the drive rotation body to the second conveyance path while guiding between the drive rotation body and the body; and the drive rotation body and the driven rotation body. A first position when the drive rotor and the driven rotor are separated from each other and when they are in pressure contact with each other with the position in the direction away from the first conveyance path from the facing position as the center. A sheet, which is provided so as to be swingable between a second position and the guide unit, is provided to face the guide means, and the sheet supplied from the first transport path at the first position is fed to the drive rotating body and the driven rotating body. And lead in the second position An elastic body that guides the sheet supplied to the transport direction changing path to the second transport path; and a position at which the driven rotating body and the elastic body supply the sheet from the first transport path to the transport direction changing path. A sheet conveying device comprising: a driving unit that moves a sheet on the conveying direction changing path to a position for supplying the sheet to the second path.