JP3659258B2 - Paper transport path structure - Google Patents

Description

  The present invention relates to a paper transport path structure used in printers, copiers, facsimiles, and the like.

  A paper conveyance path of an image forming apparatus or the like is provided with an opening mechanism so that paper jammed during conveyance can be removed.

  As one of the paper transport path opening mechanisms, there is a type in which a transport path surface on one side of the paper transport path is rotated about a support shaft and divided and developed (see Patent Document 1, Patent Document 2, and Patent Document 3).

  In this type, since a large force is applied to the support shaft, it is necessary to increase the member strength.

  In order to eliminate such inconvenience, a copying machine capable of unitizing a sheet conveying mechanism and a sheet cassette disposed opposite to the photosensitive drum and sliding the unit out of the apparatus. Has also been proposed.

However, in this type, since the transport mechanism itself and the paper cassette arranged opposite to the photosensitive drum are pulled out, the weight of the unit increases, and a large-scale mechanism such as a guide rail is required. Also, it is a burden for the user to pull out a heavy unit.
Japanese Patent Laid-Open No. 62-153866 JP-A-3-293255 JP-A-4-39238

  In view of the above facts, an object of the present invention is to slide and move one conveyance path surface of a sheet conveyance path to open the sheet conveyance path with a light and simple structure.

The invention according to claim 1 is a sheet conveyance path structure used in a sheet reversing unit for forming images on both sides of a sheet, and a fixed conveyance path surface constituting one of the conveyance path surfaces of the conveyance path to which the sheet is conveyed. A movable body that can be extracted in parallel to the fixed conveyance path surface without stacking and storing the paper and that includes the other conveyance path surface of the conveyance path; and And a sheet reversing chute that guides the sheet conveyed by a switchback roller that is provided separately and can rotate forward and backward.

  According to the above configuration, since the movable body excluding the paper reversing chute is provided so as to be able to be pulled out in parallel to the fixed conveyance path surface, the movable body can be easily flattened and the movable body can be reduced in weight. For this reason, a slide mechanism can also be simplified. Further, since the conveyance path can be opened only by the extraction operation, it is excellent in maintainability and operability. Furthermore, paper jam can be easily handled by pulling out in parallel.

In the invention described in claim 2 , the moving body is pulled out in the same direction as the paper cassette. As a result, useless dead space does not occur in the moving body extraction direction.

In the third aspect of the present invention, the driving roller is provided on the fixed conveyance path surface. The moving body is provided with a driven roller. When the moving body is slid and pushed into the apparatus, the driven roller serves as a guide roller, so that the moving body can be operated smoothly without providing a guide rail or the like.
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  When the moving body is loaded in the apparatus, the driven roller faces the drive roller and sandwiches and conveys the sheet sent to the conveyance path.

The invention described in claim 4 is characterized in that the movable body has a rectangular shape and the width is substantially the same as the opening width of the loading portion in which the movable body is loaded.

The invention according to claim 5 is characterized in that a guide is provided on the movable body along a conveyance direction in which a sheet is conveyed.

The invention described in claim 6 is characterized in that the moving body has a handle for sliding the moving body.

The invention according to claim 7 is characterized in that the movable body stops at a predetermined position when both ends of the handle abut against the housing.

The invention described in claim 8 is characterized in that a pair of transport rollers is disposed at the end of the movable body.

According to the ninth aspect of the present invention, when the movable body is loaded in the loading portion, the pair of transport rollers has a rotational force caused by a gear provided on one shaft of the transport rollers meshing with the drive gear. It is characterized by being transmitted.

  Since the present invention has the above-described configuration, it is possible to open the sheet conveyance path by slidingly moving one conveyance path surface of the sheet conveyance path. Therefore, the mechanism can be simplified and the paper jam handling operation can be facilitated.

  FIG. 1 shows an image forming apparatus 10 using a paper conveyance path structure according to this embodiment.

  The image forming apparatus 10 includes a main body unit 12, a paper discharge unit 14 that is detachably mounted on the main body unit 12, and a paper reversing unit that is detachably mounted below the main body unit 12 and the paper discharge unit 14. Switchback unit 16.

  A paper cassette 18 can be loaded into the main body 12 from the direction of arrow A. A semi-circular feed roller 20 is disposed above the paper cassette 18 and rotates to move the uppermost recording paper M to the paper transport path 22 one by one.

  A plurality of conveying rollers 24 are disposed in the sheet conveying path 22 and convey the recording sheet M sent out from the sheet cassette 18 toward the photosensitive drum 26.

  The photosensitive drum 26 is charged to a predetermined potential by a charger (not shown), and an exposure unit forms an electrostatic latent image on the charged photosensitive drum 26 based on image data. The electrostatic latent image becomes a toner image by toner supplied from the developing device, and is transferred onto the recording paper M by the transfer roller 28.

  The recording sheet M on which the toner image has been transferred is sent to the fixing device 30, and the pressure roller 32 and the heating roller 34 are heated and pressed to be thermally fixed while nipping and conveying the recording sheet M.

  As a result, a copy image corresponding to the original image is formed on the recording paper M. The recording paper on which the copy image is formed (hereinafter referred to as “copied paper C”) is sent to the paper discharge unit 14 by the guide roller 36.

  The paper discharge unit 14 is provided with a guide chute 38 that receives the copied paper C sent by the guide roller 36. On the rear end side of the guide chute 38, a discharge chute 40 and a feedback chute 42 curved in a semicircular shape are branched and provided by a switching operation of a switching claw 44 disposed at the branch point. The copied paper C is distributed to each chute. A paper detection sensor 46 is provided on the upstream side of the switching claw 44.

  Further, a discharge roller 48 is provided on the downstream side of the discharge chute 40 so as to send the copied paper C to the paper discharge tray 50.

  On the other hand, the copied sheet C conveyed to the feedback chute 42 is sent to the switchback unit 16.

  The switchback portion 16 is provided with a switchback chute 52 as a sheet reversing chute that curves in a semicircular shape. A switchback roller 54 is provided on the upstream side of the switchback chute 52.

  The switchback roller 54 rotates forward (clockwise) so that the copied paper C conveyed from the feedback chute 42 is placed with the copy image surface down to a standby unit 58 of a slide unit 56 described later. It is designed to be transported.

  In addition, a switching claw 60 is provided at a joining portion of the feedback chute 42 and the switchback chute 52. By the switching operation of the switching claw 60, the copied paper C is nipped and conveyed by the switchback roller 54 from the feedback chute 42 to the standby unit 58 or from the standby unit 58 to the switchback chute 52.

  On the other hand, in the switchback unit 16, a loading unit 62 into which the slide unit 56 can be loaded extends along the conveyance direction of the copied paper C. The bottom surface of the loading unit 62 serves as a lower conveyance path surface 66 constituting the conveyance path 64 for the copied paper C. A guide surface 66A inclined toward the rear end of the switchback chute 52 is formed on the upstream side of the lower conveyance path surface 66, and the copied paper C conveyed from the switchback chute 52 is transferred to the lower conveyance path surface. It is guided smoothly to 66. In addition, a driving roller 68 is provided on the lower conveyance path surface 66 so as to be paired with a driven roller 70 to be described later so as to sandwich and convey the copied paper C.

  As shown in FIGS. 2 and 3, the slide unit 56 loaded in the loading unit 62 includes a substrate 72 having a rectangular shape and a width substantially equal to the opening width of the loading unit 62. The substrate 72 is partially recessed downward, and a guide surface 74 is extended along the longitudinal direction (conveyance direction of the copied paper). The guide surface 74 serves as an upper conveyance path surface, and a conveyance path 64 for the copied paper C is formed between the guide surface 74 and the lower conveyance path surface 66.

  An opening 78 is partially formed in the substrate 72. A leaf spring 76 whose proximal end is fixed to the upper surface of the substrate 72 projects obliquely downward into the opening 78. A driven roller 70 is rotatably supported on the free end side of the leaf spring 76. The driven roller 70 functions as a guide roller when the slide unit 56 is loaded into the loading unit 62, rides on the driving roller 68, and presses and crimps the copied paper C fed to the conveyance path 64. It is supposed to be.

  Further, ribs 80 are extended on the upper surface of the substrate 72 at predetermined intervals along the longitudinal direction (the direction in which the copied paper is transported). A gap between the upper edge portion of the rib 80 and the main body portion 12 serves as a standby portion 58 that waits for the copied paper C fed from the switchback roller 54.

  On the other hand, a transport unit 82 is provided at the end of the substrate 72. A pair of transport rollers 84 is disposed in the transport section 82, and the copied paper C is sent out toward the transport rollers 24 of the main body section 12 through an upper opening 87. A guide plate 86 is provided below the conveying roller 84, and the guide surface is curved toward the holding surface between the driving roller 68 and the driven roller 70. By this guide plate 86, the copied paper C that is nipped and conveyed by the driving roller 68 and the driven roller 70 is guided to the conveying roller 84.

  Furthermore, a handle 88 wider than the substrate 72 is provided in the transport unit 82. The slide unit 56 is slid by gripping the handle 88, and both ends of the handle 88 abut against the housing of the switchback unit 16, whereby the slide unit 56 stops at a predetermined position.

  Next, the paper conveyance path structure according to this embodiment will be described.

  As shown in FIG. 1, when the slide unit 56 is loaded in the loading unit 62 of the switchback unit 16, the gap between the upper edge portion of the rib 80 and the main body unit 12 waits for the copied paper C. 58.

  Further, the driven roller 70 rides on the driving roller 68 and sandwiches and conveys the copied paper C sent to the conveyance path 64 constituted by the guide surface 74 and the lower conveyance path surface 66 to guide the guide plate 86. To be sent out.

  Here, a gear 90 is provided on one shaft of the transport roller 84, and when the slide unit 56 is loaded, the gear 90 meshes with a drive gear (not shown) to apply a rotational force to the transport roller 84. ing.

  In the loading operation, since the driven roller 70 serves as a guide roller, the slide unit 56 can be operated smoothly without providing a guide rail or the like.

  Here, the function of the switchback unit 16 will be described.

  The switchback unit 16 is used when a copy image is formed on both sides of the recording paper M, and is not used when a copy image is formed only on one side.

  That is, when the double-sided recording mode is selected, the copied paper C on which a copy image is formed on one side is sent to the guide chute 38 by the guide roller 36. At this time, as shown in FIG. 4, the switching claw 44 rotates clockwise and closes the start end side of the discharge chute 40, and the copied paper C is guided to the switching claw 44 to the feedback chute 42. Sent.

  Here, the switching claw 60 provided at the rear end of the feedback chute 42 is pushed by the conveyed copied paper C and rotates counterclockwise to close the start end of the switchback chute 52. The copied paper C guided by the switching claw 60 is nipped and conveyed by the switchback roller 54 and sent to the standby unit 58. In this standby state, as shown in FIG. 5, the rear end of the copied paper C is held between the switchback rollers 54. The switching claw 60 rotates clockwise by its own weight after the copied paper C is sent to the standby unit 58, and closes the rear end of the feedback chute 42 and simultaneously opens the start end of the switchback chute 52.

  Next, after the copied paper C passes through the paper detection sensor 46 provided in the paper discharge unit 14 and a predetermined time has elapsed (clock count), the switchback roller 54 reverses to switch back the copied paper C. Guide to chute 52.

  As a result, the copied paper C is sent out to the conveyance path 64 with the copy image facing up, and is nipped and conveyed by the drive roller 68 and the driven roller 70. Next, the copied paper C guided by the guide plate 86 is nipped and conveyed by the conveyance roller 84 and sent to the conveyance roller 24 of the main body 12 through the opening 87 as shown in FIG.

  Next, in the main body 12, a new copy image is formed on the surface where the copy image is not formed by the photosensitive drum 26 and the fixing device 30, and is sent to the guide roller 36. Here, the switching claw 44 rotates counterclockwise by its own weight and closes the starting end of the feedback chute 42. Therefore, the copied paper on which the copy images are formed on both sides is sent out to the discharge tray 50 through the discharge chute 40 and the discharge roller 48.

  As shown in the image forming apparatus 11 shown in FIG. 7, by providing a switching claw 92, a conveyance path 94, and a discharge roller 96 on the downstream side of the guide roller 36, the copied paper is discharged onto the upper surface of the main body 12. It is also possible to select.

  Next, it is assumed that the copied paper C is jammed in the switchback unit 16 for some reason. At this time, as shown in FIG. 2, the handle 88 is grasped and the slide unit 56 is pulled out in parallel, whereby the paper jam can be easily handled. Further, since the drawing direction of the slide unit 56 is the same as the drawing direction of the paper cassette 18, no dead space is generated around the image forming apparatus 10.

  Furthermore, since the conveyance path 64 can be opened only by the extraction operation of the slide unit 56, it is excellent in maintainability and operability.

1 is a conceptual diagram of an image forming apparatus using a paper transport path structure according to the present embodiment. It is the conceptual diagram which showed the extraction state of the slide unit concerning this form. It is the whole slide unit concerning this form. FIG. 3 is a conceptual diagram illustrating functions of an image forming apparatus using a paper conveyance path structure according to the present embodiment. FIG. 3 is a conceptual diagram illustrating functions of an image forming apparatus using a paper conveyance path structure according to the present embodiment. FIG. 3 is a conceptual diagram illustrating functions of an image forming apparatus using a paper conveyance path structure according to the present embodiment. It is a conceptual diagram showing a modification of the image forming apparatus using the paper transport path structure according to the present embodiment.

Explanation of symbols

16 Switchback part (paper reversing part)
52 Switchback chute (paper reversing chute)
56 Slide unit (moving body)
58 Standby section 62 Loading section 66 Lower transport path surface (fixed transport path surface)
68 Driving roller 70 Followed roller 74 Guide surface (upper conveying path surface)

Claims (9)

In the paper transport path structure used in the paper reversing unit for forming images on both sides of the paper,
A fixed conveyance path surface constituting one of the conveyance path surfaces of the conveyance path through which the paper is conveyed; and
A movable body that can be extracted in parallel to the fixed conveyance path surface without stacking and storing the paper and has the other conveyance path surface of the conveyance path;
A sheet reversing chute that is provided separately from the moving body behind the moving body in the extraction direction and guides the sheet conveyed by a switchback roller that can rotate forward and backward,
A paper conveyance path structure characterized by comprising:   The paper transport path structure according to claim 1, wherein the moving body is pulled out in the same direction as the paper cassette.   The paper conveyance according to claim 1, further comprising: a driving roller provided on the fixed conveyance path surface; and a driven roller provided on the movable body and configured to sandwich and convey the paper while being paired with the driving roller. Road structure.   The paper transport path structure according to claim 1, wherein the movable body has a rectangular shape and a width is substantially the same as an opening width of a loading portion in which the movable body is loaded.   The paper transport path structure according to claim 1, wherein a guide along the transport direction in which the paper is transported is extended on the movable body.   The paper transport path structure according to claim 1, wherein the movable body has a handle for sliding the movable body.   The paper transport path structure according to claim 6, wherein the movable body stops at a predetermined position when both ends of the handle come into contact with the housing.   The paper transport path structure according to claim 1, wherein the movable body is provided with a pair of transport rollers at an end.   The pair of transport rollers is configured such that when the movable body is loaded in a loading unit, a rotational force is transmitted by a gear provided on one shaft of the transport roller meshing with a drive gear. Item 9. The paper conveyance path structure according to Item 8.

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