JPH06271170A - Sheet discharging and loading device and image forming device - Google Patents

Abstract

PURPOSE:To provide a sheet discharging and loading device, which can be miniaturized while maintaining the sheet loading performance. CONSTITUTION:A sheet discharging and loading device is provided with a base tray 10a having a coefficient of friction for making the frictional force to the document smaller than the frictional force between the documents, and a slide tray 10b having a coefficient of friction for making the frictional force to the document larger than the frictional force between the documents, and the base tray 10a is arranged in the upstream of the document discharging direction, and the slide tray 10b is arranged in the downstream of the document discharging direction so that it does not contact with the document at the initial time of the discharging and that it contacts with the back surface of the document when the document is curved by a dead weight thereof with the discharging operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet discharging and stacking device for mounting a sheet such as a document or a recording sheet on an image forming apparatus for reading and recording, discharging and stacking the sheet.

[0002]

2. Description of the Related Art Conventionally, an image forming apparatus for carrying an original or a recording paper for reading or recording has been required to be downsized, and accordingly, the discharge tray should be made as short as possible within the range where the performance is exhibited. Is configured. Also, in order to eliminate jams (paper jams) in the external appearance and discharge and to convey paper smoothly, when the material of the discharge tray is SUS (stainless steel) or piano wire, the surface is plated. In the case of a mold material or the like that has undergone processing, ribs are provided upright on the stacking surface to reduce the contact area of the paper and make it slippery.

[0003]

However, in the above-mentioned prior art, when only one sheet is discharged, even if the discharge tray has a short length capable of stacking sheets,
When a plurality of sheets are discharged, the previously stacked sheets may drop.

For example, FIG. 16 shows the state of the leading end of the discharge tray 51 when the discharge of the first sheet is completed and the second sheet is discharged, and shows the force exerted by the weight of the sheet. Here, the self-weight of the sheet is N, the component force in the sheet advancing direction is n _x , and the component force in the direction perpendicular to the sheet advancing direction is n _y . Further, the self-weight of the _first sheet P ₁ is N ₁ , the component forces in the sheet advancing direction and the direction perpendicular to the sheet advancing direction are n _1x and n _1y , respectively, and the self-weight of the _second sheet P ₂ is N ₂ . The component force in the sheet advancing direction and the component force in the direction perpendicular to the sheet advancing direction are n _2x and n _2y , respectively.

FIG. 17 shows the force acting on the _first discharged sheet P ₁ . Here, the friction coefficient between the discharge tray and the paper is μ _m , and the friction coefficient between the paper is μ _p .
The force acting on the _first sheet P ₁ from the force due to the own weight of the sheet shown in FIG. 16 is as follows. First force to keep hold the sheet P ₁ on the catch tray 51, the frictional force mu _m n _1y and n _1x and the paper P ₁ of the self-weight component of the sheet P ₁ and the discharge tray 51
A n _1x + μ _m n _1y the combined. The force to Susumeyo paper P ₁ is a frictional force mu _p n _2y between the sheets.

When the discharge tray 51 is shortened, the angle α between the stacking surface of the discharge tray 51 and the back surface of the paper sheet becomes large as shown in FIG. 16, so that the component force n _{1x in the} traveling direction due to the weight of the paper sheet P ₁ becomes small. In order to ensure a smooth discharge without jamming is as small as possible a mu _m. However, the steadily reducing paper length of the discharge direction of the discharge tray _{51, n 1x + μ m n} 1y <μ p n 2y , and the first sheet with the discharge of the second sheet P ₂ There is a possibility that P ₁ may be transported and fall from the discharge tray 51.

Therefore, in order to satisfy the performance of the discharge tray 51, the length of the discharge tray 51 must be sufficiently long to effectively use the force of retaining the paper due to the weight of the paper itself. In some cases, the entire occupied area becomes large, which hinders miniaturization.

In particular, in an image forming apparatus for reducing the installation area for downsizing, there is a tendency for the vertical direction to be long and the depth direction to be thin. It is often provided in the lower part, and the paper discharge port is often provided in the upper part of the back surface of the apparatus. Therefore, when the discharge tray is provided on the upper portion of the rear surface of the apparatus, if the tray extends upward in the length direction, the apparatus as a whole requires a considerable length in the height direction, which leads to an increase in the size of the apparatus.

If the entire discharge tray is made of a material having a high friction coefficient, it is possible to solve the paper drop.
On the other hand, there was a risk of causing a jam when discharging.

An object of the present invention is to solve the above-mentioned problems of the prior art and to provide a sheet discharging and stacking apparatus which contributes to downsizing of the apparatus while maintaining the sheet stacking performance.

[0011]

A typical means for solving the above-mentioned problems of the prior art and applied to the embodiments described below is a sheet discharging and stacking apparatus for discharging and stacking sheets, which is shorter than the total sheet length. A first stacking member having a coefficient of friction such that the frictional force on the sheets is smaller than the frictional force between the sheets, and a second stacking member having a coefficient of friction such that the frictional force on the sheets is larger than the frictional force between the sheets. And the first stacking member is arranged on the upstream side in the sheet discharge direction, and the second stacking member is on the downstream side in the sheet discharge direction, and the sheets are discharged according to the discharge operation without contact at the initial stage of sheet discharge. It is characterized in that it is arranged so as to come into contact with the back surface side of the sheet when curved due to its own weight.

[0012]

According to the above means, when the first sheet is discharged, it is first discharged along the first stacking member arranged on the upstream side in the sheet discharge direction, and then the second stack arranged on the downstream side in the sheet discharge direction. The member does not come into contact with the sheet at the initial stage of sheet ejection, but comes into contact with the back surface side of the sheet when curved due to the weight of the sheet in accordance with the sheet ejection operation.

Since the first sheet is discharged along the slippery first stacking member having a low friction coefficient, it is smoothly discharged without causing a jam at the time of discharging.

Further, since the first sheet is held by the second stacking member having a large friction coefficient, the sheet curving due to its own weight and the back side contacting the second stacking member, even if the second sheet is discharged, the space between the sheets is increased. It will not be dropped due to being carried by the frictional force of.

[0015]

【Example】

[First Embodiment] Next, a sheet discharging and stacking apparatus according to an embodiment of the present invention to which the above means is applied will be described. 1 is a sectional view of the discharge tray, FIG. 2 is a perspective view of the discharge tray, and FIG.
FIG. 4 is an explanatory view showing an initial discharging operation of the A4 size first sheet, FIG. 4 is an explanatory view showing an intermediate discharging operation of the A4 size first sheet, and FIG. 5 is a drawing showing the A4 size second sheet. 8 is an explanatory diagram showing an initial ejection operation, FIG. 6 is an explanatory diagram showing an initial ejection operation of a B4 size second sheet, and FIG. 7 is an explanatory view showing a force acting by the weight of the document near the leading end of the ejection tray. FIG. 6 is an explanatory diagram showing a force acting on the first original.

First, with reference to FIG. 3, a schematic structure of a document feeding path in an image reading apparatus equipped with a discharge tray will be described. Reference numeral 1 denotes a document stack in which a plurality of documents for reading an image are stacked, and is set on the document table 2 with the document surface facing downward. When the document stack 1 is set on the document table 2, a document detection sensor (not shown) is turned on, and the pre-conveyance roller 3 rotates in the direction of the arrow in the drawing to pull the document stack 1 to the downstream side and stop it. In this stopped state, it becomes a standby and waits for a read start command.

Next, when a reading start command is given by a controller (not shown), the pre-conveyance roller 3, the separation roller 4, the conveyance roller 5, the platen roller 6 and the discharge roller 7 rotate in the arrow directions. The original stack 1 is separated one by one from the lowermost side by the separating roller 4 and the separating pad 8 pressed against the separating roller 4. The separated original 1a is read by being conveyed to the reading position by the conveying roller 5 and being conveyed while being in close contact with the reading sensor 9 by the platen roller 6. The original 1a after image reading is conveyed by a discharge roller 7 to a discharge tray 10 provided outside the apparatus and discharged.

Next, the structure of the discharge tray will be described with reference to FIGS. The discharge tray 10 is composed of the following three parts. First, the base tray 10a (first stacking member), which can be said to be the main body of the discharge tray, the slide tray 10b (second stacking member) that fits into the tip end side of the base tray 10a and is slidable in the length direction, and the slide tray. At the tip of the slide tray 10b, which is one step lower than the stacking surface of the slide tray 10b, there is a holding rubber 10c attached at two positions in the width direction at intervals smaller than the width of the document.

The above base tray 10a and slide tray 10
b is made of a molding material. As shown in FIG. 2, a plurality of ribs 10d are provided on the original stacking surface of the base tray 10a so as to project in the lengthwise direction to reduce the frictional force due to the contact between the original and the tray. Above slide tray
10b is stored in a bag-shaped storage portion 10e formed on the tip side of the base tray 10a, and a locking groove 10 formed on the slide tray 10b side is provided on a protrusion 10f projecting on the base tray 10a side.
It is held by locking g. Therefore,
The loading surface of the slide tray 10b is the base tray 10a.
It is held at a position one step lower than the loading surface. The projection 10f and the locking groove 10g are A4 or B.
The slide tray 10b is configured to be held at the positions shown by the solid line and the chain double-dashed line in FIG. 1 according to the four sizes of sheets.

Next, the operation of discharging the original document on the discharge tray 10 will be described with reference to FIGS. In this embodiment, an operation of discharging an A4 size document will be described, and the discharge tray 10 is set so as to stack an A4 size document. In FIG. 3, the first original 1a is conveyed by the discharge roller 7, abuts on the rib 10d of the base tray 10a of the discharge tray, slides, and is smoothly discharged. As shown in FIG. 3, in the initial discharge state, the document 1a is discharged in a substantially straight state without being bent by the strainer, and the document is discharged without being caught by the holding rubber 10c attached to the tip of the slide guide 10b.

Next, as shown in FIG. 4, when the discharging operation of the original 1a progresses, the leading end of the original 1a goes beyond the leading end of the discharge tray 10 and is curved by its own weight, and the back side of the holding rubber 10c is held.
To contact. Here, the new friction between the original 1a and the holding rubber 10c increases the load on the discharging operation, but the contacting portion is minute, and the frictional force between the original 1a and the holding rubber 10c is also the frictional force between the originals. Since the load is slightly larger than the above, the increase in load is extremely small and there is no problem in the discharging operation. As described above, the first original 1a is completely discharged and stacked on the discharge tray 10.

The second document 1b is separated by coming into contact with the separation roller 4 by the trailing edge of the first document 1a passing between the separation roller 4 and the separation pad 8, and the conveyance roller 5 reading position. Be transported to. Then, the original 1b is read by being conveyed while being brought into close contact with the reading sensor 9 by the platen roller 6. The original 1b after the image is read is conveyed to the discharge tray 10 by the discharge roller 7. At this time, as shown in FIG. 5, the leading edge of the original 1b contacts the first original 1a and pushes it up. That is, 1
For the first original 1a, frictional force between the originals is generated between the second original 1a and the second original 1b. Further, a new frictional force is generated between the original 1a and the holding rubber 10c located below the base tray 10a. The force acting on the original 1a at this time will be described with reference to FIGS.

In FIG. 7, the discharge of the first original 1a is completed,
It shows the state of the leading end of the discharge tray when the second original 1b is being discharged, and shows the force acting by the weight of the original 1a. Here, if the original weight of the original document is N, the component force in the original document advance direction is n _x , and the component force in the direction perpendicular to the original document advance direction is n _y , the original weight of the _first original document 1a is N ₁ , the original document advance direction, and The component forces in the direction perpendicular to the document moving direction are n _1x and n _1y , the own weight of the _second document 1b is N ₂ , and the component forces in the document moving direction and the direction perpendicular to the document moving direction are n _2x and n respectively.
_2y

FIG. 8 is a diagram showing the force acting on the discharged first original 1a. Here, holding rubber 10c and original 1
The friction coefficient with a is μ _r , and the friction coefficient between documents is μ _p . Due to the force of the original document shown in FIG.
The force acting on a is as follows. First, the force for _{holding the} document 1a on the discharge tray 10 is the frictional force μ _r between the document 1a and the discharge tray 10, n _{1x which} is the weight component of the document 1a.
a n _1x + μ _r n _1y the combined n _1y. The force to Susumeyo document 1a is a frictional force mu _p n _2y between the sheets.
Since μ _r > μ _p , it follows that n _1x + μ _r n _1y > μ _p n _2y (a), so that the first original 1a is fed along with the discharge of the second original 1b. Absent. In this way, the first original document 1a is surely stacked on the discharge tray 10 and the second original document 1b is smoothly discharged onto it.

When the third original 1c is discharged,
The original weight of the _second original 1b is N ₂ , and the component of N ₂ is n _2x , n
_2y , the weight of the _third original 1c is N ₃ , and the N ₃ component is n _{3.
If 3x} and n _3y , then μ _p n _2y + n _2x > μ _p n _3y is established, and the force for retaining the original 1b becomes larger, so that the original 1b is reliably stacked on the discharge tray 10.
Since the fourth and subsequent documents are similarly discharged, the documents are not dropped from the discharge tray 10.

The operation of ejecting an A4 size document has been described above. Next, the operation of ejecting a B4 size document will be described. When the document is discharged, the relative length between the discharged document and the discharge tray also occupies a large weight. In particular, if there are many parts that hang down on the discharge tray without hanging on the discharge tray, the drop easily occurs.
This is because n _1x described in the force relationship (a) acting on the original 1a becomes small, and in some cases, the force for holding the original and the force for moving the original may be reversed. is there. Therefore, even if the A4 size document has a sufficient stacking performance, the risk of dropping the B4 document from the discharge tray increases, and the sufficient stacking performance may not be obtained.

Therefore, as shown in FIG. 6, when the B4 original is discharged, the slide guide 10b of the discharge tray 10 is slid from the bag-shaped storage portion 10e of the base tray 10a to extend its length, and the A4 size document is discharged. Sufficient stacking performance can be obtained by discharging the document under the same conditions as when discharging the document. That is, the length of the discharge tray 10 is increased by the length of the document, and the B4 size document can be discharged under the same conditions as the A4 size document discharging operation.

With the above construction, the length of the discharge tray 10 can be shortened as compared with the conventional one, and especially when the A4 size is used, the miniaturization can be promoted as compared with the conventional one, and the size of the A4 or B4 can be improved. Even if the document is discharged, the discharging operation can be performed smoothly and the sufficient stacking performance can be maintained without dropping due to the feeding.

In the above embodiment, the holding rubber 10c is 2
Although it is provided at any position, any number of documents may be provided as long as the document discharge operation progresses and the document comes into contact with the back surface of the document in a curved state. Further, the end portion of the slide tray 10b is not limited to being attached to rubber, but any other material may be used as long as the resistance is such that the first original 1a is not pushed and dropped by the second and subsequent originals. It may be. In addition, the output tray
Although 10 is configured to be expandable and contractible, when only one type of document size is used, it may be an integrated discharge tray in the main body of the device, and if the stacking performance is sufficient even if the document size is changed, an integrated discharge tray May be

Although the image reading apparatus is used as the image forming apparatus in the above description, the image forming apparatus is not limited to this and may be another apparatus such as a printer, a copying machine or a facsimile apparatus.

[Second Embodiment] Next, another example of the sheet discharging and stacking apparatus will be described with reference to FIGS. still,
Since the schematic configuration of the entire apparatus is the same as that of the first embodiment, the same members are designated by the same reference numerals and the description thereof will be omitted. 9 is a sectional view of the discharge tray, FIG. 10 is a perspective view when the discharge tray is used for A4 size, and FIG. 11 is the discharge tray of B4 size.
It is a perspective view at the time of using for size.

In this embodiment, the discharge tray 11 is constructed as a center folding type tray, and the construction will be described below. As shown in FIG. 9, the discharge tray 11 is composed of a base tray 11a that is a tray body and an auxiliary tray 11b that is a middle bent portion. The auxiliary tray 11b is rotatably attached to the tip of the base tray 11a. ing. The base tray 11a and the auxiliary tray 11b are molded with a molding material. The auxiliary tray 11b is a base tray as shown by the solid line in FIG.
The A4 size output tray is closed when it is closed so that it overlaps with 11a.
The state in which the tray is rotated so that the top is opened serves as a discharge tray for the B4 size.

Further, at the front and rear ends of the auxiliary tray 11b, holding rubbers 11c and 11d for stopping the first original on the tray when used for A4 size and B4 size are projected, respectively. It is installed. Two of these holding rubbers 11c and 11d are attached in the width direction at a position lower than the guide surface of the auxiliary tray 11b by a distance shorter than the document width. Also, the base tray 11a is
When using for 4 sizes, the end of the auxiliary tray 11b should not be caught in the leading edge of the original so that the auxiliary tray 11b is not caught.
The stepped portion 11e is provided so that the guide surface of the base tray 11a is higher than the guide surface of.

Next, the document discharging operation for the discharge tray 11 will be described. First, when ejecting an A4 size document, it is used with the auxiliary tray 11b closed as shown in FIG. When the first document is discharged, the leading edge of the document hits the guide surface of the base tray 11a and advances. The leading edge of the above document is the stepped portion 11 of the base tray 11a.
Go over the e to the guide surface of the auxiliary tray 11b. At this time,
The guide surface of the base tray 11a is higher than the guide surface of the auxiliary tray 11b, the holding rubber 11d attached to the auxiliary tray 11b is attached to a position lower than the guide surface of the auxiliary tray 11b, and By the saw, the document advances almost straight on the base tray 11a, so that the leading end of the document is ejected without being caught.

Further, the document is sent along the guide surface of the auxiliary tray 11b and goes over the leading end portion. Even at this time, the leading edge of the document advances along the extension of the guide surface of the auxiliary tray 11b due to the document scraping, so that the leading edge of the document does not get caught on the holding rubber 11c attached at a position lower than the guide surface. As described above, the discharging operation is performed smoothly, the first document is curved due to its own weight, and the back side is the holding rubber.
11c is contacted and loaded.

In this state, the discharging operation of the second and subsequent originals is similar to that of the first embodiment described above, and the stacking performance can be maintained without the first original being dropped.

In the case of discharging a B4 size document, as shown in FIG. 11, the auxiliary tray 11b is rotated to be opened, and the document size becomes longer as the discharge tray 11 extends. The discharging operation is performed in the same manner as the original. Even at this time, since the document tip advances on the extension of the guide surface of the auxiliary tray 11b due to the document scraping, the document tip is not caught on the holding rubber 11d attached at a position lower than the guide surface. .

Therefore, it is possible to provide a small-sized discharge tray having a good stacking performance for both A4 and B4 size originals. Also, when attaching the rotating shaft of the auxiliary tray 11b to the bearing hole of the base tray 11a,
Since it can be attached with a slight deflection, it is easy to assemble.

[Third Embodiment] Next, another example of the sheet discharging and stacking apparatus will be described with reference to FIGS.
Since the schematic structure of the entire apparatus is the same as that of the first embodiment, the same members are designated by the same reference numerals and the description thereof will be omitted. Figure
12 is a sectional view of the discharge tray, and FIG. 13 is a perspective view of the discharge tray.

In this embodiment, the discharge tray is a rotary tray, and the structure will be described below. As shown in FIG. 12, the discharge tray 12 is composed of a base tray 12a which is a tray body and an auxiliary tray 12b which is a rotating portion. The auxiliary tray 12b is a rotation tray provided on the back surface of the tip of the base tray 12a. It is rotatably attached to the shaft 12e. The base tray 12a and the auxiliary tray 12b are molded with a molding material. As shown by the solid line in FIG. 12, the auxiliary tray 12b overlaps the back side of the base tray 12a so that it does not protrude from the base tray 12a and becomes a discharge tray for A4 size, which is rotated by 180 ° as shown by the chain double-dashed line. Let B in the state that it is protruding from the base tray 12a.
It becomes a discharge tray for 4 sizes.

Further, at the tip of the base tray 12a,
Holding rubbers 12c are attached at two positions in the width direction at a position shorter than the guide surface and at intervals shorter than the document width.
The holding rubber 12c is attached to a position where the original tray 12a and the guide surface of the auxiliary tray 12b are not touched with the original when the auxiliary tray 12b is rotated to project from the base tray 12a. There is.

Further, at the tip of the auxiliary tray 12b, holding rubbers 12d are attached at two positions in the width direction at intervals lower than the guide surface at intervals shorter than the width of the original.

The document discharging operation to the discharge tray 12 is the same as that of the first embodiment regardless of whether the size is A4 or B4, and the discharging operation is performed smoothly and the stacking performance is achieved without dropping the document. Can be maintained.

The base tray 12a and the auxiliary tray 12 are
Although the holding rubbers 12c and 12d are provided on each of b, the auxiliary tray
A holding rubber capable of holding a document may be attached to the front and rear ends of 12b for both A4 and B4.

[Fourth Embodiment] Next, another example of the sheet discharging and stacking apparatus will be described with reference to FIGS. 14 and 15.
Since the schematic structure of the entire apparatus is the same as that of the first embodiment, the same members are designated by the same reference numerals and the description thereof will be omitted. Figure
14 is a sectional view of the discharge tray, and FIG. 15 is a perspective view of the discharge tray.

In this embodiment, the discharge tray 13 is made of a single SUS rod and has its surface plated. As shown in FIG. 14, the discharge tray 13 has a body guide portion 13a.
The front end guide portion 13b (second stacking member) is formed in a shape (a V-shaped cross section) slightly bent counterclockwise with respect to the (first stacking member), and the tip end thereof is covered with SUS material. A rubber member 13c having a tubular shape and a slit in the axial direction is attached at two positions.

Since the bending of the discharge tray 13 is near the tip of the discharge tray, the leading edge of the first document discharged does not touch the leading end guide portion 13b of the discharging tray 13 and follows the main body guide portion 13a. Go straight. Then, when the discharging operation progresses, the original is curved by its own weight and the back surface of the original is a rubber member.
The first original is stacked in contact with 13c.

The operation of ejecting the second and subsequent originals is the same as the first operation.
Similar to the embodiment, the discharging operation is performed smoothly, and the stacking performance can be maintained without causing the documents to drop.

According to this embodiment, the discharge tray 13 is set to SUS.
Since it can be molded with a rod-shaped material such as a material, the weight feeling is lighter than that of the molding material, and downsizing in design can be realized. Further, even when the slitted rubber member 13c is attached, since the leading end of the document is discharged without touching the leading end of the tray, the original can be attached without worrying about the position of the slit, and the attachment is easy. In this embodiment, the discharge tray 13 is made of SUS material plated, but if the wire material itself is slippery, the manufacturing cost can be further reduced.

[0050]

As described above, according to the present invention, the length of the sheet discharging and stacking device for discharging sheets can be further shortened to promote the downsizing of the device, and even if sheets of various sizes are discharged. It is possible to maintain a sufficient stacking performance without causing a drop operation due to the smooth discharging operation.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a discharge tray according to a first embodiment.

FIG. 2 is a perspective view of the discharge tray.

FIG. 3 is an explanatory diagram showing an initial discharging operation of an A4 size first sheet.

FIG. 4 is an explanatory diagram showing a medium-term discharge operation of an A4 size first sheet.

FIG. 5 is an explanatory diagram showing an initial discharge operation of an A4 size second sheet.

FIG. 6 is an explanatory diagram showing an initial discharging operation of a B4 size second sheet.

FIG. 7 is an explanatory diagram showing a force acting by the weight of a document near the tip of the discharge tray.

FIG. 8 is an explanatory diagram showing a force acting on a first original.

FIG. 9 is a sectional view of a discharge tray according to a second embodiment.

FIG. 10 is a perspective view when the discharge tray is used for A4 size.

FIG. 11 is a perspective view when the discharge tray is used for B4 size.

FIG. 12 is a sectional view of a discharge tray according to a third embodiment.

FIG. 13 is a perspective view of the discharge tray.

FIG. 14 is a sectional view of a discharge tray according to a fourth embodiment.

FIG. 15 is a perspective view of the discharge tray.

FIG. 16 is an explanatory diagram showing a force acting on a document near the tip of a conventional discharge tray.

FIG. 17 is an explanatory diagram showing a conventional force acting on a document to be ejected on the first sheet.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Document bundle 1a, 1b, 1c ... Document 2 ... Document table 3 ... Preliminary transport roller 4 ... Separation roller 5 ... Transport roller 6 ... Platen roller 7 ... Ejection roller 8 ... Separation pad 9 ... Read sensor 10, 11, 12, 13 ... Ejection tray 10a, 11a, 12a ... Base tray 10b ... Slide tray 10c, 11c, 11d, 12c, 12d ... Retaining rubber 10d ... Rib 10e ... Bag-shaped storage section 10f ... Projection 10g ... Locking groove 11b, 12b ... Auxiliary Tray 12e ... Rotating shaft 13a ... Main body guide 13b ... Tip guide 13c ... Rubber member

Claims (6)

[Claims] 1. A sheet discharging and stacking apparatus for discharging and stacking sheets, the sheet stacking and stacking apparatus having a length shorter than a total sheet length, and a first stacking member having a friction coefficient such that a frictional force against the sheets is smaller than a frictional force between the sheets. A second stacking member having a friction coefficient such that the frictional force against the sheet is larger than the frictional force between the sheets, the first stacking member is disposed upstream in the sheet discharge direction, and the second stacking member is the sheet. A sheet discharging and stacking apparatus, which is arranged on the downstream side in the discharging direction so as not to come into contact with the sheet at the initial stage of discharging the sheet and to come into contact with the back surface side of the sheet when the sheet is bent by its own weight according to the discharging operation. 2. The sheet discharging and stacking apparatus according to claim 1, wherein the second stacking member is housed so as to be slidable in the lengthwise direction of the first stacking member. 3. The first stacking member has a shape in which stepped portions having different heights are formed on a sheet stacking surface, and the second stacking member is rotatably attached to the stepped portion so as to be folded. The sheet discharging and stacking apparatus according to claim 1. 4. The sheet discharging and stacking apparatus according to claim 1, wherein the length in the sheet discharging direction is variable according to the size of the sheet. 5. The sheet discharging and stacking apparatus according to claim 1, wherein the first stacking member and the second stacking member are integrally formed of a bent bar material. 6. A first stacking member having a coefficient of friction such that a frictional force on a sheet is smaller than a frictional force between sheets, and a first stacking member having a frictional coefficient such that a frictional force on a sheet is larger than a frictional force between sheets. Two stacking members, wherein the first stacking member is arranged on the upstream side in the sheet discharge direction, and the second stacking member is on the downstream side in the sheet discharge direction and does not come into contact with the discharge operation at the initial stage of sheet discharge. Accordingly, the image forming apparatus includes a sheet discharging and stacking device arranged so as to come into contact with the back surface side of the sheet when the sheet is bent due to its own weight.