JP2005306548A - Image formation device furnished with sheet loading device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive multi-bin page printer capable of eliminating a solenoid for bin selection in a bin-fixing multiple-bin sheet discharging tray. <P>SOLUTION: Selection of a bin tray is carried out by one driving source by eliminating a motive power source of each of flappers to select each bin in selecting the bin tray. For example, it is carried out by one rotary shaft and a bin selecting arm integrally rotating with the rotary shaft and pushing up each of the flappers of the bins in sequence. The selection of each of the bins is controlled by a rotating angle of the rotary shaft. Additionally, electric parts special for changing the bins are eliminated by driving the rotary shaft by reversely rotating a carrier motor. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sheet stacking apparatus including a plurality of bin trays that selectively perform processing such as sheet stacking, and more particularly to a sheet stacking apparatus used in an image forming apparatus including an image forming unit that forms an image. It is.

  Conventionally, a large number of sheet stacking apparatuses that have been arranged on an upper part of an image forming apparatus such as a printer and that have a plurality of bin trays for distributing and stacking sheets have been proposed.

Among the sheet stacking devices, the tray bin fixed type sheet stacking device in which the bin tray does not move up and down is configured to stack sheets on the selected bin tray by switching the sheet transport path simultaneously with transporting the sheets. Yes. A switching flapper or the like is used as means for selecting a bin tray on which sheets are stacked (for example, see Patent Document 1).
JP 2000-272821 A (see FIG. 6)

  As shown in FIG. 12, in the sheet stacking apparatus 1 arranged on the upper part of the image forming apparatus 2, a switching flapper 25 (35 to 39) that switches the conveyance path so that sheets are stacked on the bin tray 23 (231 to 235). Is arranged. The switching flapper 25 is driven by a solenoid (not shown), and as many solenoids as the number of switching flappers are required.

  Therefore, if a solenoid is used as the switching flapper driving means, a high-cost sheet stacking apparatus results.

  Therefore, an object of the present invention is to newly propose a switching flapper driving means for switching a conveyance path for stacking on a bin tray in an image forming apparatus including a sheet stacking apparatus that selectively performs processing such as sheet stacking. The object is to realize a low-cost sheet stacking apparatus by reducing driving parts.

In order to achieve the above object, a typical configuration of the present invention includes a plurality of bin trays for stacking sheets discharged from the image forming apparatus, and a transport unit for transporting the sheets discharged from the image forming apparatus. At least one of a first driving means for driving the conveying means, at least one conveying direction switching means for switching the sheet conveying direction conveyed by the conveying means, and the conveying direction switching means. In a sheet stacking apparatus provided with a switching direction selection means for selecting and moving one conveyance direction switching means,
The switching member selecting means is driven by a second driving means, and has the transport direction switching means according to the driving amount of the second driving means.

  As described above, according to the present invention, in the sheet stacking apparatus for stacking sheets discharged from the image forming apparatus, the selection of the switching flapper for switching the conveyance path for stacking on the bin tray is performed by the driving amount of one driving unit. By doing so, it is possible to realize a low-cost sheet stacking apparatus in which driving parts such as a solenoid for driving the flapper are reduced.

(First embodiment)
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, and the like of components described in the following embodiments should be changed as appropriate according to the configuration of the apparatus to which the present invention is applied and various conditions, and particularly specific descriptions are provided. Unless otherwise specified, the scope of the present invention is not limited to these.

  An embodiment of a sheet stacking apparatus to which the present invention is applied will be described in detail with reference to FIGS. In this embodiment, an image forming apparatus provided with a sheet stacking apparatus will be described as an example.

  FIG. 1 is a cross-sectional view of an image forming apparatus including a sheet stacking apparatus according to an embodiment.

  As shown in FIG. 1, the image forming apparatus 100 includes an image forming unit that forms an image on a sheet such as paper and an operation unit 120, and discharges the sheet to the upper surface of the image forming unit. The operation unit 120 includes operation keys (not shown) and an operation screen (not shown). The operation unit 120 performs processing for selecting a sheet size set in the cassette 114, processing for displaying a developer replenishment message, and the like.

  Further, a sheet stacking device 200 that selectively stacks sheets discharged from the image forming unit is provided above the image forming unit.

  Image data is sent to the exposure control unit 110 by a computer (not shown). The exposure control unit 110 outputs laser light corresponding to the image signal. The laser beam is irradiated onto the photosensitive drum 111, and an electrostatic latent image is formed on the photosensitive drum 111. The electrostatic latent image on the photosensitive drum 111 is developed by the developing unit 113, and the developer on the photosensitive drum 111 is transferred to the sheet fed from the cassette 114 by the transfer unit 116.

  The sheet onto which the developer has been transferred is subjected to a fixing process of the developer by the fixing roller 117. The sheet that has passed through the fixing roller 117 is guided to the discharge roller 118, and is discharged from the image forming apparatus 100 by the discharge roller 118 with the surface onto which the developer is transferred facing down (face down). The sheet discharged from the discharge roller 118 is sent to the sheet stacking apparatus 200. The sheet stacking apparatus 200 stacks sheets on the selected bin tray.

  The image forming apparatus 100 includes a motor M1 (not shown) that drives a paper feed roller 115, a registration roller 112, a fixing roller 117, and a discharge roller 118.

  The sheet stacking apparatus 200 includes a first conveying roller 211, a second conveying roller 212, a third conveying roller 213, a first discharging roller 221, a second discharging roller 222, a third discharging roller 223, a reverse switching mylar 281 and a first switching. A flapper 232, a second switching flapper 233, a first bin tray 241, a second bin tray 242, a third bin tray 243, an inlet sensor 251 for detecting a sheet, a reversing sensor 252, a reversing path 261 for reversing the sheet, and a flapper drive A device 270, a motor M2 (not shown), and a motor M3 (not shown) are provided.

  The motor M2 drives the reverse roller 201. The motor M2 drives the first transport roller 211, the second transport roller 212, the third transport roller 213, the first discharge roller 221, the second discharge roller 222, and the third discharge roller 223. The motor M3 drives the switching flapper driving device 270.

  2 to 6 are cross-sectional views of the sheet stacking apparatus 200 arranged on the upper part of the image forming apparatus 100.

  Here, the operation for discharging the sheets in the first bin tray 241 will be described. The second switching flapper 233 is deflected so as to guide the sheet to the second bin tray 242 in advance by an operation described later.

  When the image formation by the image forming apparatus 100 is finished and the sheet that has passed through the discharge roller 118 is positioned at the position of the reverse switching mylar 281 in FIG. Selected. The sheet is conveyed in the direction of arrow a along the reverse switching mylar 281.

  When the leading edge of the sheet turns on the reverse sensor 252 (FIG. 3), the reverse roller 201 is rotated in the direction (arrow b) in which the sheet is conveyed to the reverse path 261.

  When the sheet is conveyed to the reverse path 261 and the rear end of the sheet turns off the reverse sensor 252 (FIG. 4), the rotation of the reverse roller 201 is stopped. At this time, the sheet is switched upward by the action of the reverse switching mylar 281 and heads toward the first conveying roller 211.

  Here, the selection of the bin tray to be loaded is determined by the operator selecting the discharge tray in advance, and the bin tray is selected for each job by the operation unit of the apparatus or a personal computer connected to the apparatus. Although it may be performed from the host computer, it may be set in advance according to the type and contents of the job.

  After switching the second switching flapper 233, the reverse roller 201 is rotated so that the sheet is conveyed in the direction of arrow c, and the sheet is conveyed in the direction of arrow d and e and stacked on the second bin tray 242. As described above, the first conveying roller 211 and the first discharge roller pair 221 are rotated.

  By performing the above processing, the sheets are stacked on the second bin tray 242 as shown in FIGS. For the next sheet, when the leading edge of the sheet turns on the inlet sensor 251, the same processing is performed while the first and second switching flappers are switched to the positions shown in FIG. To go. In this way, the sheets are reversed and discharged face down, so that the correct page order is obtained when images are formed in order from the first page.

  Here, driving of the switching flapper will be described. 7 and 8 are diagrams illustrating the flapper driving device 270. FIG. FIG. 7 describes the operations of the switching flappers 232 and 233 and the switching flapper driving device 270 in FIGS. The switching flappers 232 and 233 in FIG. 7 and FIGS. 2 to 6 are the same state.

  Each flapper is normally urged clockwise (in the direction of arrow A) by a spring (not shown) and abuts against a stopper 285. In this figure, the first switching flapper 232 is in this state.

  The switching flapper driving device 270 is formed integrally with switching arms 270a and 270b around each axis. The switching flapper drive device 270 can be rotated in the direction of arrow B by a motor (not shown). The switching flapper driving device 270 starts rotating by driving the motor that receives the selection signal of the second bin tray 242, and stops in the state shown in FIG. At this time, the switching arm 270a is in a state in which the angle of the second switching flapper 233 is switched, and the second switching flapper 233 is held in a state in which it leaves the stopper 285 and guides the sheet to the second bin tray 242.

  When the first bin tray 241 is selected, the switching flapper driving device 270 is rotated 180 ° from the state shown in FIG. In this case, the switching arm 270 b switches the angle of the first switching flapper 232, and conversely, the second switching flapper 233 hits the stopper 285. In this state, the sheet can be guided to the first bin tray 241.

  When the sheet is guided to the third bin tray 243, the switching flapper driving device 270 is brought into a state other than the above two examples, for example, a state rotated 90 ° from FIG. The two switching flappers are in contact with the stopper, and the sheet is guided to the uppermost bin tray 243 without being switched to the flapper.

  In this configuration, the case where the bin tray is 3 bins and the switching flapper is 2 has been described, but the present embodiment is not limited to this. When the bin tray is 5 bins and the switching flappers are three as shown in FIG. 13, the switching flapper driving device 270 integrally forms four switching arms 270a, 270b, 270c, and 270d around each axis as shown in the figure. In this case, each tray can be selected by rotating the switching flapper driving device 270 every 90 °. By increasing the number of switching arms in this way, it is possible to increase the number of bins selected without increasing the number of solenoids.

(Second embodiment)
In the above embodiment, a dedicated motor is used for the flapper driving device 270, but this patent is not limited to this configuration. In this embodiment, an example is shown in which the flapper driving device 270, the transport rollers 211 to 213, and the paper discharge rollers 221 to 223 are driven by a single motor.

  FIG. 9 is a schematic diagram of drive transmission of this configuration. As shown in the figure, each transport roller and each paper discharge motor are connected to the drive motor via a drive system such as a pulley and a gear, and the switching flapper drive device 270 includes a one-way gear and a brake in the drive system. It is connected so that the drive is connected only when the motor is reversely rotated.

  When the bin tray selection operation of the above-described embodiment, that is, the rotation operation of the flapper driving device 270 is performed, the drive motor is reversed and the drive is transmitted to the flapper driving device 270.

  In this case, each conveyance roller and each paper discharge roller rotate in reverse, but there is no problem because the sheet is not being conveyed and each roller is not touching the sheet.

  The flapper driving device 270 is rotated by a predetermined amount to stop the motor when selection is completed. The drive motor is rotated forward in conjunction with the sheet receiving and discharging operations. In this case, the motor is not connected to the flapper drive device 270 by the action of the one-way gear between the drive motor and the flapper drive device 270, and the flapper drive device 270 is held at a fixed rotational position by the frictional force of the brake. Is done. As a result, the sheet is reliably discharged to the selected bin tray. FIG. 10 shows a chart in which this operation is arranged.

  In this embodiment, a multi-stage bin tray can be selected without using any solenoid or motor dedicated to bin tray selection.

(Third embodiment)
In the first and second embodiments, the switching flapper driving device 270 is a single shaft, and an example in which the switching flapper driving device 270 rotates and sequentially selects the flapper has been shown, but this patent is not limited to this form. FIG. 11 shows a third embodiment.

  The figure corresponds to FIG. 8 described above, and shows a state where the bin tray 244 is selected and the flapper 235 is deflected.

  In this embodiment, pulleys 291 and 292, a belt 293 that circulates around the pulleys 291 and 292, and a protrusion 294 integrally formed with the belt 293 are configured as a flapper driving device. In this embodiment, the pulley 292 is driven by a drive motor (not shown), and the belt 293 and the protrusion 294 move around along with the operation. The protrusions 294 sequentially push up the flappers 232 to 235. Also in this configuration, as in the first and second embodiments, an arbitrary flapper can be deflected by stopping the motor at a predetermined rotational position. In the drawing, the flapper 235 is deflected by stopping the motor at a position where the flapper 235 and the protrusion 294 are engaged, and the bin 244 is selected. Thus, the flapper can be selected according to the drive amount of the drive motor.

  Secondly, as in the embodiment, the drive motor can be shared by using a reverse rotation of the transport motor by interposing a one-way gear and a brake member between the motor and the pulley 292.

1 is a cross-sectional view of an image forming apparatus including a sheet stacking apparatus according to an embodiment. FIG. 3 is a partial cross-sectional view illustrating a detailed configuration of the sheet stacking apparatus. FIG. 3 is a partial cross-sectional view illustrating a detailed configuration of the sheet stacking apparatus. FIG. 3 is a partial cross-sectional view illustrating a detailed configuration of the sheet stacking apparatus. FIG. 3 is a partial cross-sectional view illustrating a detailed configuration of the sheet stacking apparatus. FIG. 3 is a partial cross-sectional view illustrating a detailed configuration of the sheet stacking apparatus. FIG. 3 is a partial perspective view illustrating a detailed configuration of the sheet stacking apparatus. FIG. 3 is a partial perspective view illustrating a detailed configuration of the sheet stacking apparatus. FIG. 6 is a diagram illustrating a second embodiment of the sheet stacking apparatus. FIG. 6 is a diagram illustrating a second embodiment of the sheet stacking apparatus. FIG. 6 is a diagram illustrating a third embodiment of the sheet stacking apparatus. The side view of the image forming apparatus provided with the sheet | seat stacking apparatus which concerns on a prior art form. 1 is a cross-sectional view of an image forming apparatus including a sheet stacking apparatus according to an embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Image forming apparatus 110 Exposure control part 111 Photosensitive drum 112 Registration roller 113 Developing device 114 Feed cassette 115 Paper feed roller 117 Fixing roller 118 Discharge roller 120 Operation part 200 Sheet stacking apparatus 201 Reverse roller 211 First conveyance roller 212 Second conveyance roller 213 Third transport roller 221 First discharge roller 222 Second discharge roller 223 Third discharge roller 232 First switching flapper 233 Second switching flapper 241 First bin tray 242 Second bin tray 243 Third bin tray 251 Inlet sensor 252 Inversion sensor 261 Inversion Path 270 Switching flapper driving device 281 Reverse switching mylar 285 Flapper abutting plate 291 Switching flapper driving pulley 292 Switching flapper driving pulley 293 Toggles Furappaberuto 294 switching flapper driving projection

Claims (6)

A plurality of bin trays for stacking sheets discharged from the image forming apparatus; a conveying means for conveying the sheets discharged from the image forming apparatus; a first driving means for driving the conveying means; At least one conveyance direction switching unit for switching the sheet conveyance direction conveyed by the conveyance unit; and a switching member selection unit for selecting and moving at least one conveyance direction switching unit among the conveyance direction switching units. In the sheet stacking device
The sheet stacking apparatus, wherein the switching member selecting unit is driven by a second driving unit, and selects the conveying direction switching unit according to a driving amount of the second driving unit.   The switching direction selection means includes a rotating shaft and an engaging portion that rotates integrally with the rotating shaft and engages with each of the conveying direction switching means, and the engaging portion is one of the rotating shafts. 2. The sheet stacking apparatus according to claim 1, wherein the conveyance direction switching unit is selected by sequentially engaging with each conveyance direction switching unit during rotation. The switching direction selection means includes a rotating member that rotates about a rotating shaft, an endless belt member that is driven by the rotating member to move, and an endless belt member that moves integrally with the endless belt member. It is composed of an engaging part that engages with
The said engaging part performs selection of the said conveyance direction switching means by engaging with each conveyance direction switching means sequentially in the said endless belt member one rotation. Sheet stacking device. First driving means for driving the conveying means;
In a sheet stacking apparatus comprising: a second driving unit that drives the switching control unit;
4. The sheet stacking apparatus according to claim 1, wherein the first driving unit and the second driving unit are the same driving unit.   The first driving means and the second driving means are the same motor, and when the motor is driven as the first driving means and the second driving means, the rotation directions thereof are different. The sheet stacking apparatus according to claim 4. The bin trays are arranged in a vertical arrangement;
The sheet stacking apparatus according to claim 1, wherein the sheet stacking apparatus is disposed above the image forming apparatus.

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