JP3300072B2 - Paper storage device in image forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for storing printed sheets in an image forming apparatus such as a copying machine, a printer, a plotter or the like.

[0002]

2. Description of the Related Art In general, this type of apparatus is provided with a tray for sequentially stacking and storing sheets in a discharge port of an image forming apparatus, and stacking and storing sheets fed from the discharge port on the tray. Is widely known. Also, there is known a sorter device in which a plurality of paper storage trays are provided vertically and the paper from a paper discharge port is sorted in page order.

[0003]

However, since all of the conventional storage devices are configured to stack and store sheets in a substantially flat tray provided at a paper discharge port, the image forming apparatus is required to store an image on a large-size sheet. As a storage device for forming it, it has to be enlarged. For example, Japanese Industrial Standard A0
Taking a plotter for forming an image on a sheet such as a plate, an A1 plate, or an A2 plate as an example, there is a drawback that such a sheet storage device is an inconvenient device that does not fit the actual situation requiring an extremely large installation area.

[0004] In view of the above drawbacks, the present invention has been made based on the knowledge that large-size paper having a predetermined size or more is folded and stored in a U-shape. That is, the object of the present invention is to
The storage area for the paper discharged from the image forming apparatus at a predetermined speed is divided into large-size sheets and smaller-size sheets. Another object of the present invention is to provide a sheet storage device that can store the image forming surface in either an upper side or a lower side.

[0005]

In order to achieve the above object, a paper storage device according to the present invention is provided adjacent to a paper discharge port of an image forming apparatus such as a copying machine, a printer, a plotter, etc., and is discharged from the paper discharge port. A sheet storage device for sequentially stacking and storing sheets to be stacked, a hanger means for bending and supporting the sheet in a substantially inverted U-shape in a sheet discharging direction, and a sheet hanger provided in the middle of a sheet transport path from the sheet discharging port to the hanger means. A switchable guide means for guiding the paper to one side or the other side of the hanger means and storing the image forming surface on either the upper surface or the lower surface, and a predetermined length of the hanger means has entered one side or the other side. And a shift means for displacing the paper ejection attitude direction of the hanger means to a side opposite to the entrance side of the hanger means.

[0006]

According to the above-mentioned means, the large-size paper fed out from the paper discharge port at a predetermined speed is guided to the hanger means through the paper transport path, but the guide means for guiding the paper to the hanger means. By switching the direction, the guide direction of the leading end of the sheet is selected in either the front or rear direction of the hanger means,
As a result, when the paper is finally supported on the hanger means in a substantially inverted U-shape, a so-called face-down state in which the image forming surface of the paper faces downward or a so-called face-up state in which the image forming surface faces upward. Can be stored.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a case where the present invention is applied to an image forming apparatus A including a raster plotter. The sheet storage device B configured as a unit separate from the image forming apparatus A is attached to a sheet discharge port of the image forming apparatus A.

The image forming apparatus A shown in FIG. 2 shows a thermal plotter as an example, and a roll-shaped thermal paper 1 is wound around a drum 2 and stored. The thermal paper 1 is cut at a predetermined length by cutter means 3. Reference numeral 4 denotes a pair of transport rollers, which feed out the roll-shaped thermal paper 1 and transport it to a printing point. A platen 5 is prepared at a printing point, and an overheating head 6 is provided in pressure contact with the platen 5. The paper printed by the heating head 6 is discharged from the discharge port 8 by a discharge roller 7 at a predetermined speed. Reference numeral 9 denotes a stand of the image forming apparatus A that supports the above-described image forming unit.

[0009] The usual thermal plotter as described above,
A transport motor (not shown) is connected to a drive motor (not shown) so that the transport roller 4 for feeding out the thermal paper 1 in roll form, the roll platen 5, and the discharge roller 7 transport the paper at a predetermined speed synchronized with each other. It has been done. An application controller is electrically connected to the heating head 6, which converts a computer or other image forming command into raster data and performs thermal printing in synchronization with the sheet speed of the platen 5 portion.

The above-mentioned image forming apparatus A is generally a well-known thermal plotter. However, in the present invention, an electrophotographic image forming apparatus may be used instead. In this case, the electrophotographic image forming apparatus forms an image on a photoreceptor with a laser scanning unit or an LED light emitting unit known as an optical printer, electrically adheres toner ink to develop, and develops an image on the photoreceptor. The structure of an ordinary optical printer that fixes an image after transferring it to paper may be used. Also, in the electrostatic image forming apparatus, a method of forming an image on a sheet surface with an electrostatic head and then applying and developing a toner ink to fix the sheet using a static electricity which is sensitive to the static electricity of the paper itself is also known. However, the present invention can be adopted.

A paper storage device B is provided adjacent to the paper discharge port 8 of the image forming apparatus A as described below.

The paper storage device B is provided with a receiving port 11 connected to the paper discharge port 8, and behind the receiving port 11, a flapper 12 which can be switched in two directions is provided. By switching the flapper 12, two different paper transport paths 13 and 14 following the flapper 12 can be alternatively selected. One sheet transport path 13 is a path for storing small-size paper, and forms a path extending in a substantially horizontal direction from the receiving port 11. I have. As shown in FIG. 1, the tray 16 is configured by arranging a plurality of linear members in a horizontal direction, and stacks and stacks, for example, sheets cut to A3 size or less. The other paper transport path 14 is a path for storing large-size paper, and forms a path extending in a substantially vertical direction, which is immediately turned downward from the flapper 12, and is formed in the middle of the path. Is a discharge roller 20, a guide member 21,
22, a pair of holding parts 23 and 24 are arranged in this order, and a hanger part 25 is arranged below the holding parts 23 and 24.

The discharge rollers 15 and 20 provided in the paper transport paths 13 and 14 are rotationally driven by a motor M which can rotate forward and reverse. That is, each discharge roller 1
Belts 26 and 2 between motors 5 and 20 and motor M, respectively.
7, and when one of the discharge rollers 15 rotates in the forward direction (counterclockwise in FIG. 2) when the motor M rotates forward by the action of a clutch mechanism (not shown) provided on the main shaft of the motor M. ), And when the motor M rotates in the reverse direction, only the other discharge roller 20 rotates in the reverse direction (clockwise direction in FIG. 2). Further, in this embodiment, the discharge rollers 15, 20 and the flapper 1 are used.
Belt (not shown) between the second rotating shaft 28
The flapper 12 also rotates about a rotation shaft 28 in conjunction with the rotation of the discharge rollers 15 and 20, and the paper transport paths 13 and 14 are automatically switched. In addition, in this embodiment, a pair of stopper members (not shown) for regulating the amount of rotation of the flapper 12 when switching is provided, respectively, at positions near the upper and lower sides of the flapper 12, and a torque limiter ( (Not shown), and when the flapper 12 hits the stopper member and the rotation is restricted, the rotation of the rotation shaft 28 is given by the action of the torque limiter. In addition,
In this embodiment, when the motor M stops, the flapper 12 maintains the previous switching state.

As described above, in this embodiment, the flapper 12
Switching is performed in conjunction with the rotation of the discharge rollers 15 and 20, so that a solenoid generally used as switching means is not required, and a switching direction determination circuit and a switching timing determination circuit are provided. There is also an advantage that it becomes unnecessary.

The discharge roller 20 disposed on the paper transport path 14 on the large size side has a pair of rollers 20a and 20a.
b, and one roller 20a is connected to the motor M via a torque limiter, and a rotary encoder is attached to the other roller 20b driven by the roller 20a. In this embodiment, the peripheral speed V1 of the discharge roller 20 is controlled by the discharge roller 7 of the image forming apparatus A.
(For example, about 10%). As a result, when the sheet to be discharged is restrained by both the discharge roller 7 and the discharge roller 20, the roller 20a slips due to the action of the torque limiter, and the discharge roller 20a and the discharge roller 20b associated therewith are decelerated. Then, the sheet is conveyed at the speed of the conveying roller 7 by changing to the peripheral speed V2 of the sheet discharging roller 7.

The detection of the leading edge of the sheet is performed by detecting a change when the peripheral speed of the discharge roller 20 is reduced from V1 to V2 by a rotary encoder. After the leading edge is detected, when the rotary encoder counts the number of rotations of the discharge roller 20 and counts up to a preset number of pulses, it is detected that the rotary encoder has reached the predetermined position of the approximate center of the sheet from the rotary encoder. Give a signal. The number of pulses set by the rotary encoder differs depending on the paper size.
When a paper size signal is sent from the
The side selects the set value according to the size and performs the above operation.

Immediately behind the discharge roller 20, a pair of guide members 21 and 22 are disposed facing each other with the sheet transport path 14 interposed therebetween. These members 21 and 22 are each disposed with an appropriate inclination angle, and
Are linked by Also, one guide member 22
The pivot shaft 42 provided at the upper end of the paper storage device B is supported by the frame of the paper storage device B, so that both the guide members 21 and 22 are supported.
Swings integrally about the rotation shaft 42, and the swing range w is between the solid line position and the virtual line position as shown in FIG.

As shown in FIG. 3A, one guide member 21 guides the leading end of the sheet fed from the discharge roller 20 to one side of the hanger 25 (arrow a side). . Therefore, in this case, the image forming surface 51 of the sheet
Since the side is fed so as to be in direct contact with the hanger 25, the hanger 25 is ultimately supported in a so-called face-down state. As shown in FIG. 3B, the other guide member 22 moves the leading end of the sheet fed from the discharge roller 20 when swinging to the opposite side to the other side of the hanger 25 (arrow b). Side). Accordingly, in this case, since the image forming surface 51 side of the sheet is sent upward to the hanger portion 25,
Conversely, the hanger 25 is supported face-up. Whether face-down or face-up can be easily selected by switching the guide members 21 and 22, and differs depending on the form in which the sheets accumulated in the hanger section 25 are to be collected. For example, face-down may be selected when paper is to be collected in the order in which images are formed, and face-up may be selected when printing is desired while checking the image forming surface.

Further, the guide member 2 in this embodiment
1 and 22 also serve as a shift member at the same time.
When the sheet is guided by the guide member 21 as shown in FIG. 2A, the other guide member 22 functions as a shift member. That is, the sheet is hung by the guide member 21 to the hanger 25.
Guide members 21 and 2 when guided to one side to a substantially central portion.
2 swings in the direction of the arrow, and the lower end of the guide member 22 presses the substantially central portion of the paper against the other side of the hanger portion 25 to change the direction of the paper discharge attitude, and the remaining second half from the substantially central portion of the paper. Part is led into the other side of the hanger part 25. On the other hand, FIG.
As shown in (1), when the leading end side of the sheet is guided by the guide member 22, the guide portion 21 on the opposite side acts as a shift member with the same operation as described above. In this embodiment, an example in which the guide members 21 and 22 also serve as the shift member has been described. However, the guide member and the shift member may be configured by separate members.

The hanger portion 25 includes the guide members 21 and
2, and has a substantially inverted U-shaped cross-sectional shape having a curved upper support surface. The hanger portion 25 extends in the left-right direction with the above-described cross-sectional shape, and one end or both ends thereof are attached to the frame frame of the paper storage device B. Since the hanger portion 25 according to this embodiment has a substantially inverted U-shaped cross-sectional shape and does not extend downward, the suspended end of the paper may interfere with the hanger portion 25 when the paper is suspended. Absent. Therefore,
Even if a large number of papers having curled edges are accumulated, the edges of the papers do not swell, and the papers can be accumulated smoothly. In addition, the cross-sectional shape of the hanger part 25 is not limited to the above-mentioned substantially inverted U-shape,
For example, a mountain-folded shape or a semi-elliptical shape can be appropriately selected.

The hanger portion 25 and the above-described guide member 2
A pair of holding parts 23 and 24 are provided between the hanger part 25 and the holding parts 23 and 24 for holding the paper hung on the hanger part 25 so as not to slide down. Each of these holding portions 23 and 24 is constituted by an arm member that swings around the rotation shafts 45 and 46, and each of the holding portions 23 and 24 is a retreat that does not interfere with the paper entering the hanger portion 25. It swings between a position and a hold position where the support surface of the hanger part 25 is pressed. Further, a rubber piece 47 is fixed to the tip of one of the holding portions 23, and the rubber piece 47 abuts a position slightly below the curved portion of the hanger 25 to hold the sheet. The other holding unit 24
The tip of the arm is formed by a rubber roller 48, and abuts against the curved portion on the other side of the hanger portion 25 to hold the sheet.

The pair of holding portions 23 and 24 alternately occupy the retracted position and the holding position, and one of them always holds the sheet. Paper can be prevented from slipping off the paper. The operation timings of the holding sections 23 and 24 are controlled between the holding sections 23 and 24 and the guide members 21 and 22.

Next, the operation of the paper storage device B having the above configuration will be described with reference to FIGS. First, a sheet size signal of the sheet discharged from the image forming apparatus A and a sheet discharge instruction signal are sent to the sheet storage apparatus B. In response to this, in the sheet storage device B, the motor M rotates in either the forward or reverse direction. For example, if a large-size paper signal is received,
The motor M rotates in the reverse direction, and the discharge roller 20 rotates clockwise in conjunction with the rotation. Then, the flapper 12 is further switched to one of the paper transport paths 14 in conjunction with the flapper 12. When the face-down mode is selected as the paper storage mode, the guide members 21 and 22 and the holding units 23 and 24 are set in the state shown in FIG.

The sheet conveyed from the sheet discharge port 8 of the image forming apparatus A to the receiving port 11 of the sheet storage apparatus B is conveyed into the sheet conveyance path 14 on the large plate size side selected by the flapper 12. The paper transport speed at this time depends on the peripheral speed V2 of the paper discharge roller 7 of the image forming apparatus A. However, since the paper transport path 14 extends in a substantially vertical direction, the leading end of the paper has its own weight. With the help, the sheet is smoothly guided downward in the sheet transport path 14. On the other hand, when the leading edge of the sheet is nipped by the discharge roller 20, the sheet is pulled by the discharge roller 20 due to the speed difference between the discharge roller 7 and the discharge roller 20, but the slippage occurs in the torque limiter. In synchronization with the peripheral speed V2 of the discharge roller 7. The change in the deceleration at this time is detected as a change in the cycle of the pulse generated by the rotary encoder, and the arrival of the leading end of the sheet at the discharge roller 20 is detected. Thereafter, the rotary encoder counts a predetermined number of pulses to recognize that the sheet has reached a predetermined center.

The image forming apparatus A is used instead of the above method.
, The paper discharge speed information and the paper size information are received as electrical signals, for example, a paper leading edge detection sensor is disposed near the upper side of the discharge roller 20, and the timer means is started by a signal from the leading edge detection sensor, It is also possible to calculate that the paper has reached a predetermined center.

The leading end of the sheet passing through the discharge roller 20 is guided to one side of the hanger 25 with the image forming surface facing down along the guide member 21. Then, when the sheet enters the arrow a side shown in FIG. 4A for a predetermined length and the substantially central portion of the sheet reaches the position of the discharge roller 20, the motor M is stopped instantaneously to stop the discharge roller 20. Stop rotation.

When the discharge roller 20 stops, the paper is not conveyed on the leading end side. Therefore, the trailing end of the paper fed by the rotation of the discharge roller 7 is on the paper transport path 1.
4, the guide roller 49 provided in the middle of the paper transport path 14 escapes backward as shown by a virtual line in FIG. Allows the paper to form a loop.

Next, in this state, the guide member 2
4A and 4B swing from the guide position shown in FIG. 4A in the direction of the arrow c and move to the shift position shown in FIG. Therefore, the paper is pressed in a substantially U-shape by the lower end of the guide member 22, but the paper guided to one side of the hanger 25 is not yet held by the hold 23 and is in a free state. The side is pulled back slightly. Then, in this state, the rubber piece 47 of the hold portion 23 is
Presses the hanger 25 to hold the sheet. At substantially the same time when the hold part 23 presses one side of the hanger part 25,
The other holding portion 24 releases the holding on the other side of the hanger portion 25 and starts to separate from the hanger portion 25. When the motor M is rotated at the same time, the paper is discharged from the discharge roller 2.
It is paid out again by 0. The fed-out sheet is changed in the discharging direction by the guide of the guide member 22, and the holding unit 24 returning to the retracted position also assists the loop formation. Further, since the leading end side of the sheet is held by the holding unit 23, As shown in FIG. 4C, the fed-out sheet rides over the hanger 25 while drawing a loop on the other side of the hanger 25, and the hanger 25 is moved downward with the image forming surface facing down. Guided along the other side. When the trailing end of the sheet comes off the discharge roller 20, the sheet falls by its own weight to the other side of the hanger portion 25 indicated by the arrow b, and the hanger portion 25 faces down in a substantially inverted U-shape. It will be suspended and held. Note that a series of operations described above,
That is, the guide members 21, 22,
The swing of the hold unit 23, the restart of the discharge roller 20, and the operation of the hold unit 24 are executed in a relatively short time.

In this embodiment, the guide member 22 is moved before the leading end side of the sheet is held by the holding portion 23, but the guide member 22 is first held by both the discharge roller 20 and the holding portion 23. If this is the case, it is not possible to obtain the necessary sheet margin when shifting the sheet, and the sheet may be damaged when the guide member 22 is moved to the shift position. In the above embodiment, the discharge roller 20 is used.
Although the guide member 22 is operated in a state in which the feeding of the sheet is stopped, the guide member 22 can be operated in a state in which the discharge roller 20 is kept rotating and the sheet is fed.

When the trailing edge of the sheet comes off the discharge roller 20, the guide members 21 and 22 are simultaneously or slightly delayed.
2 and the holding units 23 and 24 return to the original preparation state. Therefore, the paper is held again by the holding unit 24. After the discharge of all the sheets is completed, the face-down state paper suspended from the discharge side to the hanger 25 in an inverted U-shape is pulled obliquely downward, so that the sheets can be collected in the order of image formation. When a face-up signal is received from the image forming apparatus A, the guide members 21 and 22 and the hold members 23 and 24 are set at positions opposite to those described above. By operating the above members at the timing described above, the paper can be hung on the hanger 25 in a face-up storage mode.

On the other hand, when the small-size sheet is discharged from the image forming apparatus A, the motor M rotates in the forward direction as shown in FIG. , And the flapper 12 is switched to the paper transport path 13 side in conjunction with the rotation. Then, the sheet conveyed from the sheet discharge port 8 of the image forming apparatus A to the receiving port 11 of the sheet storing apparatus B is conveyed into the sheet conveying path 13 on the small plate size side selected by the flapper 12 and is discharged. Is discharged onto the tray 16.

[0032]

As described above, according to the sheet storage device in the image forming apparatus according to the present invention, the image forming apparatus ejected from the image forming apparatus can be formed simply by switching the guide member provided in the middle of the sheet conveying means. The finished paper can be stored in the hanger portion in either face-up or face-down form, and the paper can be quickly collected in accordance with the specifications.

[Brief description of the drawings]

FIG. 1 is an explanatory perspective view of a paper storage device according to the present invention connected to a plotter.

FIG. 2 is an explanatory cross-sectional view of a paper storage device according to the present invention.

FIG. 3 is a diagram showing a positional relationship of a guide member at the time of face-down and face-up.

FIG. 4 is an explanatory diagram illustrating an operation state when a large-size sheet is stored.

FIG. 5 is an explanatory diagram illustrating an operation state when small-size sheets are stored.

[Explanation of symbols]

 Reference Signs List A Image forming device B Paper storage device 8 Discharge port 21 Guide unit (guide unit, shift unit) 22 Guide unit (guide unit, shift unit) 23 Hold unit 24 Hold unit 25 Hanger unit 51 Image forming surface

Continuation of the front page (51) Int.Cl. ⁷ identification code FI G03G 15/00 530 G03G 15/00 530 550 550 (58) Field surveyed (Int.Cl. ⁷ , DB name) B65H 29/60 B43L 13 / 00 B65H 29/22 B65H 29/26 B65H 29/52 G03G 15/00 530 G03G 15/00 550

Claims (1)

(57) [Claims] 1. A paper storage device provided adjacent to a paper discharge port of an image forming apparatus such as a copying machine, a printer, a plotter, etc., for sequentially stacking and storing sheets discharged from the paper discharge port. A hanger means bent and supported in a substantially inverted U-shape; and a hanger means provided in the middle of a paper transport path from the paper discharge port to the hanger means for guiding a sheet to one side or the other side of the hanger means to raise the image forming surface to the upper side. Or a switchable guide means for storing on either of the lower surfaces, and displacing the paper discharge attitude direction of the paper which has entered a predetermined length on one side or the other side of the hanger means to a side opposite to the entrance side of the hanger means. A sheet storage device in the image forming apparatus, comprising: