JPH0755753B2 - Sheet sorter - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a sheet sorter used by being mounted on an image forming apparatus such as a copying machine, a printing machine, and a page printer.

[Conventional technology]

Conventionally, as a tray in a sheet sorting apparatus used in an image forming apparatus such as a copying machine, a printing machine or a page printer, for example, Japanese Utility Model Publication No. 56-10751 proposes a tray having the following structure. That is, the tray main body and the bottom plate for stacking the sheets discharged from the sorting apparatus main body are provided, and the bottom plate is supported on the tray main body so that the leading edge of the bottom plate is rotatable. The rear part is elastically supported so as to gradually descend due to the weight of the stacked sheets. Also, the bottom plate is inclined so that the leading end side in the sheet discharge direction is higher than in the initial state, and the discharged sheets fall while sliding on the slope of the bottom plate, and the trailing edge of the tray body or the sorting device with the tray attached. There is known a structure in which the main body is brought into contact with a wall portion to be stacked.

[Problems to be solved by the invention]

By the way, generally, when the speed of the image forming apparatus is increased, the speed of discharging the sheet is increased, and the discharged sheet jumps out of the tray, and if there is, a problem that the discharged sheet stops on the slope of the bottom plate of the discharged sheet occurs. The inclination is increased to prevent the above problems.

In the tray having the above-described conventional configuration, when the inclination of the bottom plate in the sheet discharging direction is increased for such a purpose, the component force of the sheet weight acting on the wall of the tray body or the sorting apparatus body due to the contact of the sheet rear end is large. Due to the frictional force generated at the abutting portion, even if the sheets are stacked on the bottom plate, the bottom plate does not go down, and the sheet overflows and scatters. The tray body or the wall of the sorting device is not lowered due to the frictional force, so that the central portion of the stacked sheets in the discharging direction has a concave shape, and the stacking of the sheets is uneven.

In order to improve this drawback, the inventors of the present application, as shown in FIG. 15, integrally form a wall surface 70 that abuts and supports the rear end edge of the stacking sheet 72 with the tray bottom surface 71, and By adopting a structure in which the wall surface 70 descends together with the bottom surface 71 due to the above, the above-mentioned drawbacks have been solved, but another problem has occurred.

That is, the upper end position of the sheet supporting wall surface 70 in contact with the trailing edge of the sheet is the sheet discharge port of the sorting apparatus body when the sheets are not stacked and the tray is not lowered.
Must be lower than 73 and therefore wall 70
The height of the sheet cannot be increased so much that the number of sheets stacked cannot be increased. Further, when the trailing edge of the sheet is to be supported not only by the tray wall surface 70 but also by the wall portion 74 of the sorting apparatus main body, the leading end of the stacked sheets 72 is displaced by m at the boundary portion, as shown in FIG. Moreover, since the sheets to be stacked suddenly shift in the middle of the sheets, an unfavorable state occurs in the sorting mode.

The present invention has been made to solve the above-mentioned problems in the conventional sheet sorting apparatus and the above-mentioned configuration proposed by the inventors of the present application. It is an object of the present invention to provide a sheet sorting apparatus including a tray that can stack a large number of sheets in an orderly manner without causing deformation of the stacked sheets.

[Means and Actions for Solving Problems]

In order to solve the above-mentioned problems, the sheet sorter of the present invention is configured so that the bottom surface of the sorter main body, which rises in the discharge direction of the sheet discharged from the sheet discharge port, contacts the rear edge of the discharged sheet. A discharge sheet stacking tray integrally formed with a supporting wall surface and having a notch in the upper portion of the wall surface, and the tray is gradually lowered with respect to the discharge port according to the amount of stacked sheets, and the lowering operation is performed for the stacking sheets. The tray elastic supporting means set to complete before the height exceeds the height of the wall surface of the tray, and the sorting device main body, which is fitted into the notch before the tray is lowered, and is provided with the stacking sheets of the tray. When the height is higher than the wall surface, a projection portion that abuts and supports the rear end edge of the seat on substantially the same plane as the wall surface is provided.

With this configuration, when the tray can be lowered, the trailing edge of the discharged sheet is supported by the wall surface of the tray, and after the lowering of the tray, the trailing edge of the sheet stacked beyond the wall surface of the tray is stacked. Since the edge is supported at the same position as the wall surface by the protruding portion provided in the sorting apparatus main body, in any case, the trailing edge of the sheet and its supporting member do not move relative to each other, and therefore the tray is lowered. Is performed smoothly by being controlled only by the weight of the stacked sheets, the deformation of the sheets does not occur due to the descending operation, and the deviation of the stacked sheets does not occur, so that a large number of sheets can be stacked in an orderly manner.

〔Example〕

Hereinafter, the present invention will be described in detail based on the illustrated embodiments. FIG. 1 shows a sheet sorter 2 according to the present invention,
Image forming apparatus 1 such as a copying machine, a printing machine, and a page printer
It is a perspective view showing the state where it was attached to. The sorting device 2 is composed of a device body 3 and a tray 4, and is fixed to the image forming device 1 by a mounting bracket (not shown). In the present embodiment, the sorting apparatus 2 is configured to receive a signal from the image forming apparatus 1 and control the sorting of discharged sheets. The sorting apparatus 2 is provided with a control circuit in the apparatus main body 3 to discharge the discharged sheets. The number of sheets may be counted and sorted according to a preset number.

FIG. 2 is a partially omitted enlarged sectional view of the sorting device 2. In the figure, reference numeral 5 denotes a main body frame, on which a sorting driven roller 6 is attached along a sheet conveying path 10 so as to be rotatable around a support shaft 36 which is substantially vertical to the conveying direction. On the other hand, a sub-frame 7 is attached to the main body frame 5 so as to be rotatable around a support shaft 8, and a sorting drive roller 9 is attached to the sub-frame 7 so as to be substantially perpendicular to the conveying direction of the discharged sheet. 6 rotation support shaft 36
It is mounted so as to be rotatable about a support shaft 26, which is coaxial with. The sorting drive roller 9 is paired with the sorting driven roller 6 to form a sorting roller that cooperates.

An upper sheet conveyance guide 11 is provided on the side of the subframe 7 along the sheet conveyance path 10, and a lower sheet conveyance guide 12 is fixedly provided to the main body frame 5 so as to face the upper sheet conveyance guide 11. There is.

A sheet detector made up of an LED 13 and a phototransistor 14 is provided outside the both conveyance guides 11 and 12 with the sheet conveyance path 10 interposed therebetween, and through a through hole provided in both the sheet conveyance guides 11 and 12. The passing of the seat can be detected.

Guide pins 15 are disposed on both sides of the lower sheet conveying guide 12 on the sheet carrying-in side so as to project to the sheet conveying path 10 and fixed to support members 16 that support the lower sheet conveying guide 12. The support member 16 is fixed to the body frame 5.

In the tray 4, a tray holding portion 18 formed integrally with the tray 4 so as to project from a hole formed in the sheet discharge side cover 17 is inserted into a tray holding member 19 arranged in the main body frame 5. By doing so, it is configured to be fixed. The tray holding member 19 is vertically movably held by the main body frame 5 by a guide roller (see FIG. 11), and is biased upward by a spring 20 having one end attached to the main body frame 5 and the other end attached to the tray holding member 19. There is.

FIG. 3 is an enlarged perspective view showing the sorting roller portion in detail. The sorting drive roller 9 is pivotally supported by fitting both ends of the roller shaft 21 into bearings 23 provided on the frame A22. A drive motor 24 is provided on one side surface of the frame A22, and the number of rotations and the direction of rotation are adjusted by a gear train 25 to rotate the sorting drive roller 9. Further, a supporting shaft 26 is fixed to the frame A22 by caulking or the like, and the supporting shaft 26 is rotatably supported by the sub-frame 7 coaxially with a supporting shaft 36 described later coaxially. .

A spring A27 is hooked on the end of the arm 22a of the frame A22, and constantly urges the sorting drive roller 9 so that it is directed in a fixed direction. Further, a stopper pin A28 is provided on the arm 22a, and the stopper pin A28 is passed through an arc-shaped hole that restricts the swing range of the stopper pin A28 provided on the sub-frame 7 (not shown). Drive roller 9 by hitting hopper pin A28 against both ends of the hole
I am trying to set the direction. Further, one end of a link 29 is rotatably attached to the arm 22a by a pin 30, and the other end of the link 29 is attached to a plunger 31 'of a solenoid 31 fixed to the subframe 7.

At both ends of the sorting driven roller 6 which is arranged so as to face the sorting driving roller 9, waist rollers 32 having a diameter slightly larger than that of the sorting driven roller 6 are provided.
And these sorting driven roller 6 and waisted roller 32
Is made of a material having a small coefficient of friction such as polyacetal, and is configured to be rotatable with a shaft 33 penetrating therethrough. Both ends of shaft 33 are frame B34
It is fitted in the notch formed in the above and is held by the spring 35, and the sorting driven roller 6 is brought into pressure contact with the sorting driving roller 9. The frame B34 is provided with a support shaft 36 having the same axis as the support shaft 26 provided in the frame A22, and the support shaft 36 is rotatably supported by the main body frame 5. At the end of the arm 34a of the frame B34, the frame A2
Similar to 2, a spring B37 and a stopper pin B38 are provided to regulate the swing range of the sorting driven roller 6 and to urge the sorting driven roller 6 so as to face a fixed direction. Further, one end of a link 39 is rotatably attached to the arm 34a of the frame B34 by a pin 40, and the other end of the link 39 is attached to a plunger 41 'of a solenoid 41 fixed to the main body frame 5. .

Next, the operation of the sorting roller will be described with reference to FIG. FIG. 4 is a diagram showing a sheet discharging operation as viewed from above. Hereinafter, the right side or the left side means the right side or the left side in FIG.

At the start, since the sorting signal is not sent from the image forming apparatus 1, the solenoids 31 and 41 do not operate. Therefore, the springs A27 and B37 cause the sorting rollers 6 and 9 to move the sorting rollers 6 and 9 in solid lines in FIG. As shown in, it is turned to the right side. In this case, assuming that the operator is on the right side, the solenoids 31 and 41 are arranged on the right side and the springs 27 and 28 are arranged on the left side in order to make it easier to take out the discharge sheet. If so, the solenoids and springs may be left and right interchanged, or the solenoids may be operated from the initial state so that the sorting rollers 6 and 9 are directed to the left side. Further, when the solenoids 31 and 41 for driving the drive roller 9 and the driven roller 6 are arranged on opposite sides, the respective solenoids are alternately operated, so that the peak of the operating current value can be kept low. A small-capacity power transformer can be used, and the device can be downsized. However, this method is
There is a risk that it will not be possible to sort discharged sheets, or to stack them on one side.

In the above initial state, the sorting roller is used in this embodiment.
6, 9 are inclined to the right by α degrees (8.5 ° in this embodiment).
In this state, the sheet A discharged from the image forming apparatus is eaten by the sorting rollers 6 and 9, but the leading edge of the sheet remains at a right angle to the central axis 42, and the sheet B is at the position indicated by the sheet B in the direction of α degrees. Proceed towards. When the discharged sheet reaches the position of the sheet B, the right side edge of the discharged sheet contacts the guide pin 15. In the state where the sheet B is abutting against the guide pin 15, it is impossible to proceed to the right side of α degree with the tip of the sheet kept at right angles to the central axis 42, so that the sheet B is centered around the guide pin 15.
The discharge sheet at the position of rotates. Then, when the sheet C reaches the state where the direction of the sheet coincides with the direction of α degree, the rotation is stopped and the sheet is discharged in the α degree direction. Then, it is stored in the position indicated by the sheet D on the tray 4.

By the way, in order to rotate the discharged sheet from the state of the sheet B to the state of the sheet C, the sheet has to slip at the nip portion of the sorting rollers 6 and 9, but if it is slippery with the nip portion, for example, the conveyance guides 11 and 12. The sheet rotates due to a load caused by friction between the sheet and the sheet, and the stacking of the discharged sheets on the tray 4 becomes uneven.

The elements that rotate the sheet are the width of the sorting roller,
Although there are materials and nip pressure, the feed is stable, and it rotates under the load caused by contact with the guide pin 15 and does not rotate under other loads. It was found that the shape shown in FIG. 5 is preferable.

First, since the drive roller 9 and the driven roller 6 are separately supported by separate frames, it is difficult to keep the contact in a line contact state at all times during operation. The sheet may come into contact with each other, and the sheet feeding direction may become extremely unstable. In the present embodiment, in order to prevent the occurrence of this point contact state, the diameter of the central portion of the drive roller 9 is made smaller than the diameter of the outer portion so that both rollers 6 and 9 always contact at two points. Configured. And specifically, the width 1 of the drive roller 9 is 20 to 70.
mm, the outer contact width l ₁ with the driven roller 6 is 3 to 10 mm, and the diameter of the central part is made small so as not to contact, and the material is rubber such as chloroprene rubber or ethylene propylene rubber, and the hardness is 40 to 70 °. Things were good. The material of the driven roller 6 is polyacetal, and the total nip pressure is 50 to 200g.
Was suitable.

Further, on the driven roller side, a waisted roller 32 is provided in order to attach a waist to the discharged sheet. The waisted roller 32 is arranged near both ends of the sorting driven roller 6,
The sorting driven roller 6 has a diameter slightly larger than that of the driven roller 6. Then, the sheet 53 is formed into a wavy shape by the shapes of the driven roller 6 and the waisted roller 32,
The sheet 53 is prevented from bending in the discharging direction by its own weight, and is effective for stably discharging and stacking the sheet 53. It should be noted that the provision of the waisted roller is a technique generally used in the discharging device of the image forming apparatus.

In the present embodiment, the diameter D ₂ of the waisted roller 32 is set to be ₂ to 8 mm larger than the diameter D _{1 of} the sorting driven roller, and the waisted roller is positioned at l ₂ = 5 to 10 mm from the end surface of the sorting driven roller. It was optimal to have 32 end faces.

Now, when a series of sheets have been discharged to the right side of the tray 4, that is, at the time when, for example, a certain data is printed out and the next data is printed out, a signal from the image forming apparatus main body causes The solenoids 31,41 are energized, which causes the plungers 31 ', 41'
Is sucked, the frame A22 and the frame B34 are rotated about the support shaft 26 and the support shaft 36 via the links 29 and 39, respectively, and the sorting rollers 6 and 9 are moved to the left by α degrees (in this embodiment,
8.5 °) Can be tilted. Stopper pin A28 and stopper pin
Since each frame rotation angle is regulated by B38, even if it is tilted to the left, the shaft 21 of the sorting drive roller 9
And the shaft 33 of the sorting driven roller 6 are held parallel to each other. The solenoid remains energized until the next printout is completed, that is, while the sheet is discharged to the left side. The discharging mechanism to the left side of the sheet in this case is the same as the discharging mechanism to the right side.

When discharging to the left side is completed and the next data is printed out, the solenoids 31 and 41 are de-energized by a signal from the image forming apparatus such as a printer, and the sorting rollers are again set by the springs A27 and B37. 6,9 are tilted to the right. This series of discharges is called a job, and an operation of sorting jobs (in the present invention, an operation of sorting left and right)
Is called a job separator, and such a sorting device is generally called a job separator.

The sheets that have been sorted into the left and right on the tray 4 and discharged are partly overlapping with each other on the central axis 42, so that the sheets serve as bookmarks. Therefore, it is possible to distinguish the jobs even if they are repeated many times, and it becomes extremely convenient to organize the discharged sheets after printing.
In the present embodiment, the left and right distribution angles are set to 8.5 °, but the present invention is not limited to this, and in order to sort, the left and right distribution angles are set in the range of 5 ° to 45 °. be able to.

Next, the structure of the tray will be described. FIG. 6 is a perspective view showing the overall construction of an embodiment of the tray, FIG. 7 is a partial sectional view showing the inclination of the ridgeline on the central axis of the tray, and FIG. 8 is a view showing the tray shown in FIG. It is an end view seen along with the inclination of the ridge.

As can be seen from these figures, in this embodiment, the shape of the tray 4 is such that the central portion is raised in a mountain shape, the ridge line 43 thereof is inclined upward along the discharging direction, and the tip portion is gradually widened. It is configured. Ridge 43 is θ from horizontal
₁ = 20 ° to 40 °, and the left and right bottom surfaces 44 and 45 have an inclination of θ ₂ = 5 ° to 20 ° with respect to the horizontal plane. In addition, a sheet side edge guide member 48 having a chevron cross section is arranged near the right and left side ends toward the outside at an angle of θ ₃ = 0 to 10 ° with respect to the perpendicular. Further, a notch concave portion 49 is provided at the center of the bottom end of the sheet in the sheet discharge direction so that the sheets stacked on the tray 4 can be easily taken by one hand so that the stacked sheets can be collectively taken out by one hand. . A wall portion 50 is integrally formed on the sheet discharge port side of the tray 4, and a pair of convex portions 69 [FIG. 12-1 to FIG. 12-3]], a pair of concave portions 51 into which the convex portions 69 can be fitted are formed. Further, on the wall portion 50, a pair of tray holding portions 18 for fixing to the sorting apparatus main body 3 are integrally formed so as to project toward the sheet discharge port side. Horizontal surfaces 46 and 47 are formed at the left and right corners of the bottom surfaces 44 and 45 on the sheet discharge port side.

Next, the sheet discharging and stacking operation will be described with reference to FIG. The sheet 53 ejected from the sorting rollers 6 and 9 is ejected substantially horizontally without bending and sagging due to the action of the waist roller and the like, and contacts the tray 4 at a point b on the ridgeline 43 of the tray 4. After that, the sheets are further sorted by rollers 6,
The sheet is discharged by 9, and the leading edge of the sheet reaches point c due to the momentum of the discharging speed v ₀ . The sheet that reached point c is
Since air is accumulated between the sheet and the bottom surface of the tray 4, the sheet gradually drops, and the inclination angle θ _{1 of the} ridgeline and the inclination θ of the bottom surface θ
₂ slides on the tray bottom surfaces 44 and 45, contacts the sheet side edge guide member 48 and the ridge 52 of the wall portion 50, and stops.

In this way, the discharged sheets are sequentially stacked on the tray 4, but if one of the stacked sheets is significantly displaced or if the displacement is about 1 mm, a considerable number of sheets will be displaced. When the user is present, it gives a very uneven feeling to the user. Therefore, the stacked sheets are required to be neatly aligned without a shift of about 1 mm.

In the tray configured as in this embodiment, the sheet discharging speed v ₀ and the discharging angle θ _{4 of the} sorting rollers 6 and 9 are set.
When, the inclination angle theta ₁ of the ridge line 43 of the tray 4, and the inclination theta ₂ of the bottom surface 44 and 45 each other interrelated, it was found that the influence on the stacking aspect of the sheet.

As a result of the experiment, the sheet discharge speed v ₀ is 300 to 900 mm / sec.
Then, the inclination angle of the ridge line θ ₁ = 20 to 40 °, the inclination angle of the bottom surface θ ₂ =
It was found that the range of 5 to 20 ° and the discharging angle of the sorting roller θ ₄ = 0 to 15 ° are preferable. However, since the sheet discharge speed v ₀ by the sorting roller is determined by the sheet discharge speed of the image forming apparatus, other factors will be set accordingly.

The ejection speed of the page printer we tested this time is 160 mm /
Since it is sec, the sheet ejection speed of the sorting device is 550
When set to mm / sec, the inclination angle of the ridge line is θ ₁ = 29 °, the inclination angle of the bottom surface is θ ₂ = 10 °, and the discharge angle of the sorting roller is θ ₄ = 5 °.
In this case, the best stacking state of sheets was obtained.

Next, the relationship between the respective elements that affect the sheet stackability will be further described. If the first or too fast sheet discharge speed v ₀ to the inclination angle θ ₁ of the ridge line, or with respect to the sheet discharge speed v ₀ small inclination angle θ ₁ of the ridge line is, or sheet've jumped from tray 4, or By the time the trailing edge of the sheet reaches the wall 50, the trailing edge of the sheet has fallen completely onto the bottom of the tray or the lower sheet,
The frictional resistance with the bottom surface or the lower sheet causes the slippage to stop, causing a problem that it stops before reaching the wall portion 50.

The most desirable mode is that the trailing edge of the sheet falls on the tray bottom or the lower sheet until the trailing edge of the sheet reaches the wall 50, and the sliding resistance is braked by the frictional resistance between the sheet and the bottom sheet or the lower sheet. When it reaches 50, the seat collides with the wall 50 with the sliding speed of the seat becoming considerably small. Contrary to this, when the sheet hits the wall portion 50 at a high speed, the recoil of the sheet causes the sheet to bounce, which causes uneven stacking of the sheets. Therefore, it is not good to set the inclination angle θ ₁ of the ridge more than necessary. In particular, when the inclination angle θ _{1 of the} ridgeline becomes large, in addition to the phenomenon that the sheet is rebounded, the sheet has no rigidity in the thickness direction, so that the sheet easily buckles, and the stacked state deteriorates.

The discharge angle θ ₄ of the sorting rollers 6 and 9 is for adjusting the position of the point b where the tray 4 and the sheet first come into contact with each other. Although the relationship with the inclination angle θ ₁ of the ridge line 43 of the tray is deep,
The angle θ ₅ formed by 43 (This is the inclination angle θ ₁ of the ridge 43 and the discharge angle θ
₄ ) is large, the sheet below may be pushed out by the discharged sheet.

A proper inclination angle θ ₂ of the bottom surface is necessary to prevent the sorted sheets from shifting in the left-right direction. That is, when the discharged sheet falls on the bottom surface, air is accumulated between the sheet and the bottom surface. Then, as the air escapes, it gradually drops with the sheet, but when the bottom of the tray is horizontal, the sheet falls while swinging left and right, back and forth just like the leaves of the tree, so it was loaded. The sheets will be uneven. Therefore, it is necessary to tilt the bottom surface of the tray to the left, right, front and back, and slide the sheets on the bottom surface to improve the alignment.

The front-back inclination of the tray is obtained from the inclination angle θ _{1 at the} ridge line, and the left-right inclination of the tray is obtained from the inclination angle θ ₂ of the bottom surface. Since the discharged sheet is already in contact with the tray at the portion beyond the contact b, the left and right shakes are suppressed and the sheet falls but is not perfect. In this embodiment, since the vertical sheet (sheet in which the fibers extend in the conveying direction) is used, the rigidity in the thickness direction in the horizontal direction is further weaker than that in the vertical direction, and therefore the inclination angle θ _{2 of the} bottom surface is set. If the value is increased, it will buckle and the loading condition will deteriorate. Therefore, the tilt angle θ of the bottom surface
₂ cannot be as large as the inclination angle θ ₁ of the ridge.

Further, if the inclination angle θ _{2 of the} bottom surface is large, as shown in FIG. 10-1, the sheet does not bend along the bottom surface 44, 45 on the ridge line 43, and therefore the ridge line is set in consideration of the number of sheets to be stacked.
If the distance e ₁ to the upper surface of the stacked sheets is larger than 43 and the inclination angle θ _{2 of the} bottom surface is smaller than 43, the distance e ₂ from the ridge line 43 to the upper surface of the sheet can also be small, as shown in FIG. 10-2. Further, when the inclination angle θ _{2 of the} bottom surface is large, as shown in FIG. 10-1, the side edge 56 of the stacked sheets 54 and the leading edge of the first sheet 55 sorted on the opposite side are in contact with each other. Therefore, the stacking sheet 54 may be pushed out. In particular, since fibers are protruding from the end surface of the sheet, the sheet is easily caught, and this phenomenon easily occurs. For the above reason, the tilt angle θ of the bottom surface
₂ was not large, and as described above, θ ₂ = 10 ° was the most preferable value.

When the sheet sorter equipped with such a tray is used by being connected to an image forming apparatus such as a medium speed page printer, the number of trays required to be stored is 500 or more. As the number of stored and loaded trays increases, the position of the contact b between the leading edge of the discharged sheet and the ridgeline of the tray shown in FIG. 9 changes, so the number of stored and loaded sheets is 200 depending on the distribution of the number of sheets to be sorted into left and right. When the number of sheets is about 300 or more, the already stacked sheets may be pushed out, or the ridge line 52 of the tray wall portion 50 may not be slid down and the sheets may stop midway due to frictional resistance between the sheets. Therefore, it is necessary to lower the tray downward as the number of sheets loaded on the tray increases.

It is possible to arrange the self-weight lowering mechanism for lowering the tray at the lower part of the tray, but if the mechanism is arranged at the lower part of the tray, a space for that is required, which is an obstacle to downsizing of the device. Occurs.

In the embodiment of the present invention, in order to improve this point, the self-weight lowering mechanism of the tray is arranged in the lower part of the sheet sorting apparatus main body, and the entire apparatus is made compact.

FIG. 11 is a perspective view showing such a tray self-weight lowering mechanism applied in the sorting apparatus of the present invention. The first
In FIG. 11, the body frame 5 and the sheet discharge side cover 17 are not shown. The tray 4 has its tray holder 18
The tray holding member 19 arranged inside the main body frame 5.
It is inserted into the insertion hole provided in and fixed with screws 58. Guide rollers 59 are provided on the left and right sides of the tray holding member 19.
Two of each are rotatably attached by a shaft 60. And the guide roller 59 is the main body frame 5 (second
(See the drawing) and is configured to move up and down along a guide hole 61. Also, two guide rollers 62 are rotatably attached to the side surface of the tray holding member 19 opposite to the tray insertion side by a shaft 63 so as to move up and down along a guide hole 64 provided in the main body frame 5. I am configuring. Then, the tray holding member 19 is urged toward the upper surface of the main body frame 5 by the spring 20 (see FIG. 2), and when no sheets are stacked on the tray 4, the guide rollers 59, 62 have guide holes 61, It is stopped while being pushed up to the uppermost position of 64.

When the sheets are stacked on the tray 4, the spring 20 extends due to the weight of the sheets, and the guide rollers 5 are guided along the guide holes 61 and 64.
9, 62 move while rolling, and the tray holding member 19 descends. Therefore, the tray 4 supported by the tray holding member 19 also descends according to the number of stacked sheets.

Generally, a sheet used in a page printer is a high quality paper having a thickness of 60 to 120 g / m ² and a thickness of 70 to 120 μm. When using a sheet of A4 size (210 x 297 mm), assuming that the unit weight is 90 g / m ² and the thickness is 95 μm, the spring constant k of the spring 20 is k = 90 g / m ² x (0.21 m x 0.297 m ) × (1 / 0.00095m) = 590
0g / m = 5.9g / mm. However, the weight of the sheet actually used is 60 to 120 g
The spring constant k does not necessarily have such a value because it varies from / m ² , but the tray is lowered almost in proportion to the sheet loading amount, and the sheet to be ejected and the tray or the sheet is loaded on the tray. If the contact point b with the sheet (see FIG. 9) does not greatly shift, a good stacking state can be obtained.

If the discharged sheets are not sorted, the sheets are stacked on the right side of the tray. Alternatively, depending on how to sort, many sheets may be stacked on the left side. In these cases, the load applied to the tray becomes unbalanced left and right, but since the tray holding member 19 is supported in the left and right direction by the guide rollers 62 and the guide holes 64, the tray 4 does not tilt and the descent thereof is smooth. To be done.

By the way, in order to stack the discharged sheets sorted by the sorting device without shifting, the sheet stacking bottom surface of the tray and the wall portion supporting the sheet rear end are integrally formed, and the tray is elastically supported. When the tray is configured to descend by the sheet weight, the height of the wall portion 50 of the tray is mainly the contact point b between the tray 4 and the discharged sheet and the ridge line 43.
Is determined by the inclination of. Therefore, if the tray and the lowering mechanism having such a structure are used, the stacking sheet amount becomes large and the tray lowers.
As shown in the figure, the trailing edge of the eject sheet 72 is
After that, the sheets come into contact with the wall portion 74 of the sorting apparatus body to be stacked. In this case, the leading edge of the stacked sheet 72 is displaced from the leading edge of the sheets stacked in the tray by m,
Moreover, it suddenly shifts in the middle of the stacked sheets,
It is not preferable in terms of sorting. Further, the drawbacks described above also occur.

In order to solve this point, in the present invention, as shown in FIG. 12-1, a perspective view, FIG. 2-2 showing the upper surface of the main part and FIG. A pair of convex portions 69 are arranged on the sheet discharge side cover 17 so as to correspond to the pair of cutout concave portions 51 formed in the central portion of the wall portion 50. That is, the upper end position of the convex portion 69 is set so that the upper end position, that is, the height of the wall portion 50 of the tray 4 in the state where no stacked sheets are present is set to be the same.
The convex portion 69 is inserted into the concave portion 51 provided on the wall, the inner surface of the wall portion 50 and the surface of the convex portion 69 coincide with each other, and the length of the convex portion 69 is set larger than the descending amount k of the tray 4. There is. The tray self-weight lowering mechanism is configured so that the lowering operation of the tray 4 is completed by the sheet weight before the height of the stacked sheets exceeds the wall portion 50.

With this configuration, when the amount of stacked sheets increases and the operation of lowering the tray 4 by k ends, the discharged sheets are stacked over the wall portion 50 of the tray 4, but the wall portion The rear end of the sheets stacked over 50 is supported by the central corner portion 69a of the surface of the convex portion 69. Further, since the surface of the convex portion 69 is arranged so as to coincide with the surface of the wall portion 50, it is supported together with the discharge sheet supported by the ridge 52 of the wall portion 50. The displacement as shown in the figure does not occur, and the user does not feel uncomfortable.

Further, the trailing end of the discharged sheet is supported by abutting against the ridge 52 of the wall portion 50 that descends together during the tray lowering operation, and after the lowering is completed, the surface of the convex portion 69 provided on the sheet discharge side cover 17 is Since the sheet is abutted against and supported by the central corner 69a, in any case, the rear end of the sheet is prevented from moving relative to the abutting and supporting member, and therefore the tray is lowered when the sheet falls. The weight is controlled only by the weight, and the lowering operation does not deform the trailing edge of the sheet, so that a large number of sheets can be stacked in an orderly manner.

In the embodiment shown in FIGS. 12-1 to 12-3, a protrusion for contacting and supporting the rear end of the stacked sheets after the completion of the lowering operation of the tray is separately provided on the sheet discharge side cover 17. However, as shown in the perspective view of FIG. 13-1 and the top view of the main parts of FIG. 13-2, the contact support protrusion is integrated with the sheet discharge side cover 17. It can also be formed. That is, the protrusion 69 ′ may be integrally formed with the sheet discharge side cover 17 so as to have the same protrusion surface shape as the protrusion 69. Further, the abutment support protrusions are not limited to the block-like ones as in the above-described embodiment, but may be constituted by strip-like protrusions, and similar operational effects can be obtained.

Unless the operator removes the sheets stacked on the tray, they will accumulate, and when they reach the discharge port, the sheets will be pushed out of the tray. Therefore, when the operator forgets to remove the sheets, it is necessary to detect that a predetermined number of sheets are stacked on the tray and stop the operation of the image forming apparatus such as the page printer.

14-1 and 14-2 are diagrams showing a configuration example of means for detecting the amount of sheets stacked on the tray. 14th-
In the configuration example shown in FIG. 1, the tray holding member 19 comes into contact with the actuator 66 at the lowered position, and the micro switch 65
Is configured to operate. That is, as the sheets are stacked on the tray 4, the weight of the tray 4 and the tray holding member 19 lowers against the spring 20, and when a predetermined number of sheets are stacked, the lower end of the holding member 19 contacts the actuator 66. When the sheets are further stacked, the micro switch 65 operates to send a detection signal. This detection signal is transmitted to the CPU of the image forming apparatus main body, and is configured to control the operation of the image forming apparatus to stop after printing a predetermined number of sheets.

FIG. 14-2 shows the actuator 68 on the tray holding member 19 when the tray holding member 19 is in the raised position, that is, when no sheets are stored on the tray.
The micro switch 67 is arranged so that the contacts are pressed against each other. In this configuration example, as the sheets are stacked on the tray 4, the tray 4 and the tray holding member 19 are lowered due to the weight thereof, the actuator 68 moves, and the micro switch 67 operates to send a detection signal. The main body of the image forming apparatus starts counting the number of prints by the detection signal of the micro switch 67, and terminates the operation of the image forming apparatus after counting the predetermined number. In this configuration example, a micro switch is used as the detection means, but any sensor that can detect the operation of the tray holding member can be used.

〔The invention's effect〕

As described above with reference to the embodiments, according to the present invention, when the tray is in the descent state, the trailing edge of the discharge sheet is supported by the wall portion of the tray, and after the descent of the tray is completed, the wall portion of the tray is The trailing edge of the sheets stacked over
In any case, the rear end of the sheet and its supporting member do not move relative to each other because they are supported by the protrusions provided in the main body of the sorting apparatus, and therefore the tray lowering is governed only by the weight of the stacked sheets. Therefore, the descending operation does not cause deformation of the sheets and the deviation of the stacked sheets does not occur, so that a large number of sheets can be stacked in an orderly manner.

[Brief description of drawings]

FIG. 1 is a perspective view showing a state in which a sheet sorter according to the present invention is mounted on an image forming apparatus, and FIG. 2 is an enlarged cross-sectional view of a main body part of an embodiment of the sorter according to the present invention. FIG. 4 is an enlarged perspective view of a part of FIG. 2, FIG. 4 is an explanatory view showing a sorting operation of the sorting apparatus shown in FIG. 2, and FIG.
A plan view of the sorting roller, FIG. 6 is a perspective view of the tray,
FIG. 7 is a partial sectional view thereof, FIG. 8 is an end view thereof, FIG. 9 is an explanatory view showing a sheet discharging / stacking operation in a tray, and FIGS. 10-1 and 10-2 are trays. Showing a stacking mode of discharged sheets due to a difference in inclination of the bottom surface of the tray, FIG. 11 is a perspective view showing a tray weight lowering mechanism, and FIG. 12-1 is
FIG. 12-2 is a perspective view showing the arrangement of the tray and the convex portion for supporting the rear end of the sheet, FIG. 12-2 is a top view of a main part thereof, FIG. 12-3 is a cross-sectional view of the main part, and FIG. , A perspective view showing a modified example of the embodiment shown in FIG. 12-1, FIG. 13-2 is a top view of a main part thereof, and FIGS. 14-1 and 14-2 are tray load detection, respectively. FIG. 15 is a diagram showing a configuration example of the means, and FIG. 15 is a diagram showing a stacking mode of discharged sheets when the tray is lowered in the sheet sorting apparatus proposed by the present inventors. In the figure, 1 is an image forming apparatus, 2 is a sorting apparatus, 3 is a sorting apparatus body, 4 is a tray, 5 is a body frame, 17 is a sheet discharge side cover, 18 is a tray holding portion, 19 is a tray holding member, and 20 is a tray holding member. Springs, 44 and 45 are the bottom of the tray, 50 is the wall, 51
Is a notched concave portion, 52 is a ridge, 69 is a convex portion, and 69 'is an integrally projecting portion.

Claims (1)

[Claims] 1. A bottom surface of a sorting apparatus main body, which rises in the discharge direction of a sheet discharged from a sheet discharge port, and a wall surface which abuts and supports a rear end edge of the discharged sheet, are integrally formed. A discharge sheet stacking tray having a notch in the upper portion of the wall surface, and the tray is gradually lowered to the discharge port according to the amount of stacked sheets, and the lowering operation is performed such that the height of the stacked sheet exceeds the height of the wall surface of the tray. Tray elastic supporting means set to be completed before, and provided in the sorting apparatus main body, fitted into the notch before the tray is lowered, and when the height of the stacked sheets in the tray is higher than the wall surface, the sheet is rearward. A sheet sorting device, comprising: a protrusion that abuts and supports an edge on substantially the same plane as a wall surface.