JP2003026348A - Paper feeder and image forming device therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To separate and convey a plurality of types of paper sheets one by one without no feeding or double feed. SOLUTION: One end of a sheet material 2 loaded on a bottom plate 1 of a cassette 11 is brought into pressure contact with a paper feeding roller 4 to approach the pressure-contact section. An inclined member 6 is brought into pressure contact with the paper feeding roller 4 so as to advance and retreat in parallel, so that the area of a contact surface 6b with the paper feeding roller 4 of the inclined member 6 is reduced, thus minimizing turning together with the sheet material 2. The top sheet material 2a delivered by the counter-clockwise rotation of the paper feeding roller 4 pushes the inclined member 6 aside and is supplied by the friction with the paper feeding roller 4. The second sheet material 2b, having small friction between the sheet materials, is stopped by the inclined material 6, thus preventing double feed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device for feeding a stacked sheet material separately from the uppermost sheet material and feeding the sheets, and an image forming apparatus such as a facsimile machine, a printer, and a copying machine. Regarding the device.

[0002]

2. Description of the Related Art Conventionally, in a sheet feeding device for separating a stacked sheet material from an uppermost sheet material positioned at the top one by one and feeding the separated sheet material to an image forming section, Corner claw separation method that separates both widthwise ends at the front end in the feeding direction with claw members, separation pad method that separates the sheet material by pressing the friction member, and a fixed gate member that has a sloped surface. There is a bank separation method that separates them by abutting. Of these, the well-known separation method has a small number of parts, is low cost, and can be applied to a wide variety of sheet materials (for example, postcards, envelopes, OHP paper, etc.) including thick paper and thin paper with the same configuration but different sizes. Pad system,
Alternatively, for example, there is a bank separation system as disclosed in Japanese Patent Laid-Open No. 8-91612.

[0003]

However, in the conventional sheet feeding device adopting such a separation system, the former separation pad system has a particularly low cost of 10 PPM (image forming speed of 10 per minute). In the case of a low-speed machine of (sheets) or less, the sheet material held between the feed roller and the friction member causes an abnormal noise due to sticking slip during conveyance.Therefore, it is necessary to take measures to make the feed roller half-moon shaped. Occurs. Therefore, it is necessary to additionally provide a pair of cylindrical collars having a diameter slightly smaller than the diameter of the above-mentioned paper feed roller on the both sides of the paper feed roller so as to be coaxial with the paper feed roller. As a result, the number of parts increases and the production cost rises.

Further, recently, with the increase in the use of recycled paper, there are many things such as postcards, envelopes, and the like, in which the leading end of the sheet material in the conveying direction is blunted, and burrs are generated during cutting. However, there is also a problem in that the separation pad method easily causes the sheet material not to be fed. In addition, the reuse of backing paper is increasing due to the reuse of copy paper, and the variation in the coefficient of friction between stacked sheet materials may increase, resulting in double-feeding. As a result, the sheet material is curled, and depending on the curling direction, a load may occur at the tip of the sheet material at the sheet material separating portion, or the sheet material may not be conveyed to the separating portion and may not be fed.

In the case of the separation pad system, since the flat portion of the pad is pressed against the paper feed roller, it corresponds to the conveying direction of the sheet material fed from the stacked state (corresponding to the displacement angle of the sheet material stacking member such as the bottom plate). ), The angle of the separation pad must be within a predetermined range. For that reason, the roller diameter of the paper feed roller is limited, and the flexibility of the layout is restricted, so that the paper feed device can be downsized. There is also a problem in that it cannot be planned. On the other hand, in the case of the latter bank separation method,
Japanese Patent Application Laid-Open No. 8-91612 discloses that the upper edge portion of the inclined member which is in contact with the sheet feeding roller is flat, the nip portion with the sheet feeding roller is wide, and the inclined surface is formed due to variations in the member. It becomes difficult to arrange at a predetermined inclination angle.

Further, normally, when the uppermost sheet material is being conveyed in the image forming section, the drive of the sheet feeding roller is cut off, but the preceding sheet material is nipped between the sheet feeding roller and the gate member. During the interval, the paper feed roller is rotated by the frictional force with the sheet material, and when the trailing edge of the preceding sheet material passes through the nip portion, the leading edge of the next sheet material is tilted by the rotation of the paper feeding roller. Sent to the member. At this time,
When the coefficient of friction between sheet materials is high or varies widely, and the coefficient of friction between the next sheet material and the next sheet material is lower than the coefficient of friction between the preceding sheet material and the next sheet material. However, there is a risk that the next sheet material will get over the inclined member, resulting in double feeding.

Generally, in a paper feeding device in which a cassette having a sheet material stacking member whose one end is swingably supported and whose free end is biased upward is removably mounted through an opening of the apparatus main body. It is usual that a separating portion of the sheet material, which is in pressure contact with the tilting member and the sheet feeding roller, is disposed on the inner side of the apparatus main body. Therefore, when the cassette is pulled out for replenishment with the sheet material reduced, the sheet material stacking member may be caught inside the apparatus main body and cannot be pulled out. In order to solve such a problem, conventionally, for example, as shown in FIG. 59, one end of the compression spring 3 is supported in the cassette 11 by a support shaft 1a so as to be swingable.
A pair of arms 1c, 1c are provided on both sides of the bottom plate 1 which is a sheet material stacking member whose free end is always urged upward.
(Only one of them is shown in the figure)
Correspondingly, a guide rail 10c is provided on the apparatus main body 10 side, and when the cassette 11 is pulled out in the Y direction shown by the arrow, the arm 1c is brought into sliding contact with the guide rail 10c and the bottom plate 1 is resisted against the urging force of the compression spring 3. It is also known that the cassette 11 is lowered as shown in FIG. 3 and is held at that position when the cassette 11 is pulled out by a well-known locking means.

However, in such a sheet feeding device,
Although the bottom plate 1 is prevented from being caught when the cassette 11 is pulled out, the tilting member 6 causes the sheet feeding roller 4 to press the compression spring 5 when the sheet has been fed before the cassette 11 is pulled out.
Since the sheet is pressed by, the leading end of the next sheet material 2n remains nipped by the sheet feeding roller 4 after the sheet is fed (see FIG. 60). Cassette 1 in this state
When 1 is pulled out to replenish the sheet material and the sheet is re-set, the sheet material 2n remaining in the apparatus main body 10 is crushed by the reset cassette 11 to close the separation portion by the inclined member 6, The problem that paper cannot be generated occurs.

In order to solve this point, conventionally, a means for releasing the pressure of the inclined member is provided in association with the drawer of the cassette, a method of drawing the sheet material that has been nipped together with the cassette, and a tip of the sheet material that is nipped is scraped out. There are a method of separately providing an arm in the cassette, a method of detecting the drawer of the cassette and rotating the paper feeding roller in the direction opposite to the paper feeding direction to separate the leading end of the sheet material from the nip portion. However, among these, the first and third methods cause a decrease in production efficiency due to an increase in the number of parts and assembly man-hours, and in the second method, the sheet material presses the inclined member and presses the tip of the bottom plate. Since the sheet is attempted to be scraped out while being nipped by the pressure, the sheet material may be damaged and remain in the vicinity of the nip portion depending on the material.

Further, in the paper feeding device in which the bottom plate for stacking the sheet material is inclined and is located on the back surface of the image forming apparatus or the like, the sheet material conveying guide is fixed on one side and the sheet material is fixed on one side for mechanical reasons. There are some concerns about skew, and there was a desire to solve it. Further, in an image forming apparatus having a simple structure, the paper feeding device is driven by a single motor that is commonly used for driving the image forming unit, so that the load on the drive motor can be reduced. Was requested. In addition, in this type of paper feeding device, when a large number of sheet materials with uneven ends are set, the sheet material cannot be set between the paper feed roller and the bottom surface, and the conveyed sheet material is If the paper is caught on the paper feed roller and the tip portion is damaged, and if the paper is left without noticing it, a jam may occur at the time of paper feeding. The present invention has been made in order to solve these problems, and provided with a sheet feeding device capable of surely separating and transporting a wide variety of sheet materials one by one without feeding or double feeding An object is to provide an image forming apparatus.

[0011]

SUMMARY OF THE INVENTION The present invention provides a sheet feeding device for feeding sheet materials stacked on a swingable sheet material stacking member by separating them one by one from the uppermost sheet material.
In order to achieve the above object, a sheet feeding roller which presses the uppermost sheet material and feeds this sheet material to a separating portion,
An inclined member is provided which is in pressure contact with the sheet feeding roller and has an inclined surface against which the front end of the sheet material in the feeding direction abuts. The inclined member has a contact surface with the sheet feeding roller in the axial direction of the sheet feeding roller. It is formed as a ridge extending along. Further, in the paper feeding device, the tilting member may be in pressure contact with the paper feeding roller in a swingable manner, and has a parallel moving means for moving the paper feed roller back and forth in parallel. It is also possible to do so, and it is preferable that the parallel moving means comprises a rib provided on one of the tilting member and the apparatus main body and a guide rail provided on the other side.

Further, in such a sheet feeding device, it is preferable that the length of the contact surface of the inclined member is smaller than the length of the sheet feeding roller in the axial direction, and the inclined member is formed of synthetic resin, It is more preferable to cover at least the contact surface with the paper feed roller with a metal plate, and it is preferable that the metal plate has elasticity. It is more preferable that the elastic metal plate is mounted from the inclined surface side so as to hold the inclined member from both upper and lower surfaces. further,
In the above-described sheet feeding device, the distance along the sheet material conveying direction between the portions where the sheet materials stacked on the inclined member and the sheet material stacking member are in pressure contact with the sheet feeding roller is set to 2 mm to 6 mm, and The angle of the inclined surface of the inclined member with respect to the sheet material conveying direction is 50 ° to 70 °.
Set to °.

Further, in the above-mentioned sheet feeding device, it is possible to provide a thin plate elastic member which intersects the tangential direction of the abutting portion downstream of the abutting portion between the sheet feeding roller and the inclined member. The thin plate elastic members may be provided on both sides of the sheet feeding roller, or may be provided substantially at the center of the sheet feeding roller. It should be noted that a thin plate having a hook-shaped bent portion at the rear end portion, which intersects the tangential direction of the contact portion and is bent toward the feed roller, is provided downstream of the contact portion between the feed roller and the inclined member. Elastic members may be provided, and the thin plate elastic members may be provided on both sides of the sheet feeding roller, or may be provided at substantially the center of the sheet feeding roller. Also, the thin plate elastic member is 20 ° to 60 ° with respect to the tangential direction.
To cross at. Further, in the above-described paper feeding device, downstream of the contact portion between the paper feeding roller and the inclined member,
It is also possible to provide a friction member that intersects the tangential direction of the contact portion, and the friction member may be provided on both sides of the paper feed roller, or may be provided substantially at the center of the paper feed roller.

Further, in the above-mentioned sheet feeding device, a pressure lever whose free end can be brought into contact with and separated from the sheet material stacking member, and a cassette having the sheet material stacking member axially mounted coaxially with the pressure lever. It is also possible to provide a detection lever that rotates by insertion and removal and an elastic member that is engaged between the detection lever and the pressure lever. The pressure lever may be configured to be rotatable in conjunction with the detection lever when the angle with the detection lever becomes larger than a predetermined angle, and the detection lever has the free end at the free end. It is further preferable to form a pair of arm portions extending on both sides of the inclined member and to allow the arm portion to pass on both sides of the contact surface of the inclined member by rotating the detection lever. Further, it is preferable that the detection lever is provided with a spring pressure varying portion capable of adjusting the biasing force of the compression spring that presses the inclined member against the sheet feeding roller, and the spring pressure varying portion is the detection lever. Is rotated to engage with and disengage from a spring pedestal provided on the opposite side of the compression spring to the inclined member so as to be slidable in the axial direction of the compression spring, thereby engaging the spring pedestal with the inclined member. It is better to be able to drive in the direction.

Further, it is preferable that a first cam is provided coaxially with the sheet feeding roller so as to come into contact with both side ends of the leading end portion of the sheet material stacking member to separate the sheet material stacking member from the sheet feeding roller. It is more preferable that the sheet material stacking member is provided with restraining ribs at both ends of the tip end portion thereof, with which the first cam can come into contact. Further, in the above-mentioned paper feeding device, a second cam may be provided coaxially with the paper feeding roller so as to come into contact with both side ends of the tilting member to separate the tilting member from the paper feeding roller. It is preferable that the member is provided with ribs at both ends which the second cam can contact. Furthermore, in the paper feeding device, the second
Between the cam and the tilting member, a tilting member restraining plate that escapes a portion where the paper feeding roller and the tilting member come into contact with each other is provided, and a tip portion of the tilting member restraining plate is provided upstream of the paper feeding roller from the sheet material stacking member. It is preferable to make it open.

Then, a large amount of the sheet material stacked on the sheet material stacking member that rises and lowers in a horizontal state is raised to a predetermined sheet feeding position and held at that position, and the sheet material is placed one by one from the uppermost sheet material. In a sheet feeding device that separates and feeds, a sheet feeding roller that presses the uppermost sheet material and feeds this sheet material to a separating portion, and a separating roller that is provided in the separating portion with an axial position fixed, The separation roller is provided with an inclined surface that is in pressure contact with the front end of the sheet material in the feeding direction,
An inclined member having a contact surface with the separation roller formed on a protrusion extending along the axial direction of the separation roller is provided, and the paper feed roller and the separation roller are provided at positions different in the sheet material conveyance width, respectively. There is also provided a sheet feeding device arranged symmetrically with respect to the center line of the sheet material conveying width. Further, in the paper feeding device, the separation roller may be arranged at the center of the sheet material conveying width and the paper feeding rollers may be arranged on both sides of the separation roller, respectively. It is also possible to dispose the separation roller at both sides of the paper feed roller at the center of the width, and the material of the separation roller is preferably a synthetic resin material.

An image forming apparatus provided with such a sheet feeding device and an image forming means for forming an image on a sheet material fed from the sheet feeding device is also provided. The sheet feeding device and the image forming apparatus including the same according to the present invention are configured as described above, and with a simple configuration, the influence of the bending elastic modulus of a wide variety of sheet materials can be drastically reduced, and various sheet materials can be used. The sheets can be separated one by one and reliably fed without causing non-feeding or double feeding, and image formation can be reliably performed.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below with reference to the drawings. 1 is a longitudinal sectional view showing a first embodiment of the present invention, FIG. 2 is an exploded perspective view showing the entire structure thereof, and FIG. 3 is an explanatory view showing a part of FIG. 1 in an enlarged manner. First, the overall configuration of the sheet feeding device according to the present invention will be described with reference to FIGS. The shallow box-shaped device body 10 having low-profile wall surfaces on four sides has a side opening 10b.
The cassette 11 is detachably attached through the through. A bottom plate 1 which is a sheet material stacking member capable of stacking a plurality of sheet materials 2 shown in FIG. 1 is rotatably supported at one end by a spindle 1 a in the cassette 11 and is attached to the cassette 11. The free end is constantly biased upward in FIG. 1 by the compressed spring 3.

A compression spring 3 is attached to the main body 10 of the apparatus as shown in FIG.
In the paper feed roller 4, a paper feed roller 4 is provided so as to be in pressure contact with the leading end portion of the uppermost sheet material 2a of the sheet material 2 stacked on the bottom plate 1 having a biasing force in the counterclockwise direction. The contact surface 6 of the inclined member 6 having the inclined surface 6a
b is pressed by the urging force of the compression spring 5, and these constitute a separating portion for the sheet material. As shown in FIG. 2 and FIG. 10 in which a part of the tilt member 6 is enlarged, ribs 6d, 6d projecting from the left and right side surfaces are slidable on the guide rails 8, 8 on the apparatus body 10 side. It is mounted so that it can be moved in parallel in the direction in which it is pressed against the paper feed roller 4 while being guided by, and a pair of hooks 6f, 6f for preventing slipping out are provided in the lower part.
Are extended, and they are engaged with a locking portion (not shown) of the apparatus main body 10 to regulate the rising limit. On the downstream side of the inclined member 6, a pair of transport rollers 7 (only one is shown in FIG. 2) for transporting the sheet material 2 fed by the paper feed roller 4 to an image forming unit of an image forming apparatus (not shown). ) Is rotatably supported. The parallel moving means of the tilting member 6 includes a guide rail on the tilting member 6 side, and a main body 10 of the apparatus.
It does not matter if ribs are provided on the side.

Now, with reference to FIG. 3, the relationship among the sheet material 2 stacked on the bottom plate 1, the paper feed roller 4 and the inclination member 6 will be described in more detail. The inclined surface 6a of the inclined member 6 is
The uppermost sheet material 2a of the plurality of sheet materials 2 stacked on the bottom plate 1 is set at a predetermined angle θ with respect to the feeding direction S of the sheet feeding roller 4. The contact surface 6b, which is continuous with the inclined surface 6a and contacts the sheet feeding roller 4, is formed as a ridge extending in the axial direction of the sheet feeding roller 4, and its width is extremely narrow. It should be noted that the above-mentioned ridge may be formed of a continuous single piece or may be formed of a plurality of intermittent pieces. Then, the pressure-contacting portion A of the uppermost sheet material 2a on the bottom plate 1 which pressure-contacts the sheet feeding roller 4.
The distance between the inclined surface end 6c at which the inclined surface 6a of the inclined member 6 and the contact surface 6b intersect and the press contact portion B of the sheet feeding roller 4 along the sheet material feeding direction are made as close as possible to each other. When the paper feed start signal is issued from the control unit, the paper feed roller 4 is allowed to rotate until the feeding of the uppermost sheet material 2a is completed.

As described above, by reducing the distance between the two pressure contact portions A and B, the bending range of the tip end of the sheet material becomes narrow even with various sheet materials having different bending elastic coefficients.
As a result of the bending elastic moduli approaching each other, variation in component force generated on the inclined surface 6a of the inclined member 6 is suppressed, and needless to say in the case of thick paper, postcard, envelope, etc. having a large bending elastic coefficient, thin paper having a small bending elastic coefficient. It becomes possible to separate even such sheet materials, and it is possible to correspond to a wide variety of sheet materials.

Next, the operation of the embodiment configured as described above will be described with reference to FIGS. 4 to 7 as needed. FIG. 4 shows the force relationship of the uppermost sheet material 2a. As a force for feeding out a plurality of stacked sheet materials 2 to the separating portion by the sheet feeding roller 4, the tip of the uppermost sheet material 2a is used. The force F acts on the inclined surface 6 a of the inclined member 6. Inclined surface 6a
Is set to form an angle θ with respect to the feeding direction S of the uppermost sheet material 2a. The component force F1 is perpendicular to the inclined surface 6a and the component force F is parallel to the inclined surface 6a.
2 occurs. Further, the separation pressure Q of the compression spring 5 that presses the inclined member 6 against the sheet feeding roller 4 is set at a predetermined angle α with respect to the feeding direction S of the sheet material 2, and this separation pressure Q is the above-mentioned component force. By setting it to be smaller than the α component F1α of F1, the uppermost sheet material 2a gets over the inclined surface 6a of the inclined member 6 and is fed in the direction of the conveying roller pair 7 shown in FIG.

FIG. 5 shows the force relationship of the next sheet material 2b. The force Fp acts on the next sheet material 2b due to the friction load with the next sheet material 2c. F
p generates a component force Fp1 in the vertical direction on the inclined surface 6a of the inclined member 6 and a component force Fp2 along the inclined surface 6a. However, since the coefficient of friction between the sheet materials is generally about 50% of the coefficient of friction between the sheet feeding roller and the sheet material, the force Fp is also about 50% of the force F shown in FIG. No force is generated over the inclined surface 6a of the sheet 6, and the sheet is stopped by the inclined member 6 and separated from the uppermost sheet material 2a.

Further, even when the contact surface 6b of the inclined member 6 with the sheet feeding roller 4 is abraded by the friction with the sheet material to become the abrasion contact surface 6b 'shown by the broken line in FIG. 6, the inclined member 6 is formed. Since the compression spring 5 only moves in parallel to the direction of the separation pressure Q, the separation condition can be maintained without changing the predetermined inclination angle θ (FIG. 3) of the inclined surface 6a. Further, by reducing the contact surface 6b of the inclined member 6 with the sheet feeding roller 4, the nip portion with the uppermost sheet material 2a is reduced from the conventional nip width D to the nip width C, and the uppermost sheet material 2a is reduced. After the trailing edge of the sheet material 2a has passed through the nip portion, the feed amount of the nip width that gives the feeding force to the next sheet material 2b is reduced by the rotation of the sheet feeding roller 4, so that the sheet material 2 is double-fed. It becomes possible to suppress.

In the sheet feeding device having such a structure, since the slanting member 6 has a complicated shape, it is preferable to integrally mold it with a synthetic resin. In that case, as shown in FIGS. 8 and 9, if the length L of the contact surface 6b of the inclined member 6 is larger than the axial length L2 of the sheet feeding roller 4, the sheet is fed at the time of conveyance of the sheet material (not shown). The contact surface 6b of the inclined member 6 that is pressed in the direction of the roller 4 and is in sliding contact with the sheet material.
Since the separation pressure is applied to the central portion of the sheet, only the central portion of the contact surface 6b pressed by the sheet feeding roller 4 through the sheet material is worn and depressed. When the inclination member 6 is deformed in this way, when the sheet material enters between the sheet feeding roller 4 and the inclination member 6, the sheet material is curved while following the deformed contact surface 6b of the inclination member 6. To be done. Therefore, the conveyance load of the sheet material is significantly increased, or the sheet material having a high rigidity cannot be bent, and the sheet is not fed.

FIG. 10 is an exploded perspective view showing a second embodiment of the present invention which solves the above problems. In this embodiment, the length of the contact surface 6b of the inclined member 6 is smaller than the length of the paper feed roller 4 in the axial direction so that the entire length of the contact surface 6b can always contact the paper feed roller 4. The other configurations are the same as those in the first embodiment described above. According to this structure, the contact surface 6b of the inclined member 6 is pressed by the sheet feeding roller 4 through the sheet material over the entire length, so that a partial depression is formed in the contact surface 6b. The contact surface 6b is linearly averaged and worn. Since the inclined member 6 moves in parallel to the direction of the sheet feeding roller 4, the inclined surface 6a of the inclined member 6 maintains a predetermined angle with respect to the sheet material conveying direction even if the contact surface 6b is worn. It is possible.

FIG. 11 is an exploded perspective view showing a third embodiment of the present invention which solves the above problems, and FIG. 12 is a vertical sectional view thereof. In this embodiment, the inclined surface 9a is engaged with the inclined surface 6a and the contact surface 6b of the inclined member 6, respectively.
Then, the thin elastic metal plate 9 having the contact surface 9b bent is inserted from the inclined surface 6a side of the inclined member 6. As a result, the elastic metal plate 9 is expanded from the state shown by the phantom line in FIG. 12 against its elastic force and then contracted and fixed as shown by the solid line. In the third embodiment, since the surfaces of the inclined surface 6a and the contact surface 6b of the inclined member 6 are closely adhered and covered by the elastic metal plate 9, the sheet material conveying direction and the inclined surface 6a.
It is possible to greatly reduce the wear of the tilting member 6 due to the friction with the seat plate while keeping the angles .theta.
In the above embodiment, the inclined surface 6a is also covered at the same time for the reason of mounting the elastic metal plate 9, but this is not always necessary. Further, in the case of the third embodiment, the wear itself of the inclined member 6 is suppressed, so that the length of the contact surface 6b is free and can be determined independently of the length of the paper feed roller 4 in the axial direction.

From the results of repeated experiments, the conditions for good separation of the sheet material 2 in these embodiments are, as shown in FIG. 7, on the bottom plate 1 pressed against the paper feed roller 4. The distance X in the sheet material feeding-out direction between the pressure-contacting portion A of the sheet material 2 and the pressure-contacting portion B of the inclined member 6 that presses the sheet feeding roller 4 is set to 2 to 6 mm, and the feeding direction S of the sheet material 2 to be fed is set. It was found that the angle θ formed by the inclined surface 6a of the inclined member 6 should be 50 ° to 70 °. By doing so, it has been confirmed that good separation quality can always be obtained as long as the paper feed roller 4 has a size that is normally used, for example, in the range of φ16 to 36 mm.

Further, in the above embodiment, the metal plate covering the contact surface 6b of the inclined member 6 is not limited to the elastic metal plate, and a metal plate having no elasticity may be used. In that case, the metal plate 9 ′ (see FIG. 13) in which the elastic metal plate 9 shown in FIGS. 11 and 12 is removed on the downstream side of the portion covering the contact surface 6b of the tilting member 6 is stopped from the lower surface of the tilting member 6. Screw 1
It should be screwed with 6. As described above, in the inclined member 6 in which the contact surface 6b with the sheet feeding roller 4 is covered with the elastic metal plate 9 or the metal plate 9 ', the wear is practically negligible, so that the supporting method is not always parallel. No need to move,
As shown in the fourth embodiment of FIG. 13, there is no problem even if the support shaft 6e of the tilting member 6 and the shaft hole 10a of the apparatus body 10 swing, and the tilting member 6 is given a biasing force in the direction of the paper feed roller 4. The separation compression spring may be the torsion spring 15 attached by mounting the support shaft 6e.

In the third and fourth embodiments shown in FIGS. 11 to 13, the inclined member made of a synthetic resin material, which is relatively easily worn, is covered with the metal plate. The same effect can be obtained by molding with a hard synthetic resin reinforced with carbon fiber or glass fiber and further applying a thick metal plating to the contact surface with the paper feed roller. In the above-described first to fourth embodiments, the double feeding and the non-feeding of the sheet material are prevented by specifying the shape and the configuration of the inclined member. However, due to an unexpected situation, the two sheet materials may not be fed. When the contact portion between the paper feed roller and the tilting member is crossed over, 2
Since there is no load member that suppresses the first sheet material,
Both sheets may be double-fed to the image forming unit.

FIG. 14 is a longitudinal sectional view showing a fifth embodiment of the present invention made to solve the above-mentioned point, and FIG. 15 is an exploded perspective view thereof. In addition, in the following embodiments, in order to simplify the configuration and the illustration, although not particularly shown,
The tilting member 6 is provided with the elastic metal plate 9 or the metal plate 9'as described above, or the tilting member 6 itself is made of a material resistant to wear, and its supporting method is swing support by the support shaft 6e. The case will be described, but it goes without saying that it is also possible to make parallel movement.

14 and 15, the tilting member 6
The pair of support shafts 6e, 6e and the shaft hole 10 of the device body 10.
a, 10a (only one of them is shown in FIGS. 14 and 15)
And pivotally support the support shaft 6e so that the position of the support shaft 6e is located on the tangent line E of the paper feed roller 4 at the contact surface 6b.
In addition, a pair of thin plate elastic members (hereinafter referred to as "mylar") 1
The base portions 2 and 12 are fixed to the inner surface of the rear wall of the apparatus main body 10, and the tip portions thereof intersect the tangent line E on both sides of the paper feed roller 4. The thin plate elastic member is preferably made of a synthetic resin material, but may be made of a metal plate. With such a configuration, when the two sheet materials are transported over the contact surface 6b of the inclined member 6, the two sheet material tip portions press the tip portions of the mylars 12 to bend the sheets. The second sheet material is dammed at two points on the tip of the mylar 12, and only the first sheet material is fed to prevent double feeding.

In the above-described embodiment, the tip portions of the two sheet materials that have passed over the contact surface 6b of the inclined member 6 are subjected to a load that causes the pair of mylars 12 and 12 to bend against the elasticity thereof.
Since I tried to stop the first sheet material, myra 1
The load of pressing and bending the tips of the Nos. 2 and 12 can be doubled to ensure the double feed preventing effect, but the positions where the pair of Mylars 12 and 12 are arranged are back and forth, or the elasticity is different. In this case, the second sheet material stands by in the skewed state, and there is a possibility that the sheet material may be skewed and conveyed in that state during the next sheet feeding. FIG. 16 is a longitudinal sectional view showing a sixth embodiment of the present invention in consideration of this point, and FIG. 17 is an exploded perspective view thereof.

That is, the base of the mylar 12 is fixedly provided on the inner surface of the rear wall of the apparatus main body 10 substantially in the center of the paper feed roller 4 in the axial direction, and the tip of the mylar 12 is provided substantially at the center of the inclined member 6 for escape. It is inserted through the opening 6f and projected upward, and intersects with the tangent line E. In addition, by providing the opening 6f, the torsion springs 15 and 15 for connecting the support shafts 6e and 6e in place of the coil springs as the separation compression springs for pressing the tip end of the inclined member 6 against the sheet feeding roller 4 are provided. To use.
According to such a configuration, even if two sheet materials are conveyed by passing through between the sheet feeding roller 4 and the contact surface 6b of the inclined member 6, the sheet material comes into contact with the mylar 12 and bends. The second sheet material is dammed and double feeding is prevented.
At this time, since the mylar 12 locks almost the center of the tip of the second sheet material, it is possible to further suppress the skew waiting.

Next, FIGS. 18 and 19 show a seventh embodiment of the present invention in which the shape of a pair of Mylars provided downstream of the contact surface 6b of the inclined member 6 is changed. In this embodiment, an obtuse-angled bent portion is formed in the middle of the pair of mylars 13, 13 whose base is fixedly provided on the inner surface of the rear wall of the apparatus body 10, and a bent portion of which the tip is in the direction of the paper feed roller 4 is substantially a right angle. Is provided to form a first bending piece 13a and a minute second bending piece 13b, and the first bending piece 13a intersects the tangent E of the contact portion between the sheet feeding roller 4 and the tilting member 6 at an angle α. They are arranged on both sides of the paper feed roller 4. Here, as a result of experiments, it has been found that the angle α is appropriate to be 20 ° to 60 ° with respect to the tangent line E, although it is related to the bending rigidity of the mylar 13. Note that other configurations are shown in FIGS.
Is the same as.

In the above structure, when the two sheet materials are conveyed over the abutting portion of the sheet feeding roller 4 and the slanting member 6, the tip of the second bending piece 1 is the tip of the mylar 13.
The sheet material collides with 3b and becomes a conveyance load, and the two sheet materials are separated. At this time, in the case of a thin sheet material, the uppermost first sheet material escapes from the second bending piece 13b of the bending mylar 13 and is conveyed, and the thick thick sheet material is the first sheet material of the mylar 13. The bent sheet 13a is bent and conveyed, and the second sheet material is stopped by the second bent piece 13b of the mylar 13.

Further, FIG. 20 shows the first embodiment of the present invention in which the above-mentioned mylar 13 is provided substantially at the center of the sheet feeding roller 4, and correspondingly, an opening 6f for escape of the mylar 13 is provided at the center of the inclined member 6. It is a disassembled perspective view which shows 8th Embodiment. Also in this case, since the opening 6f is formed in the central portion of the inclined member 6, the torsion springs 15 and 15 for supporting the support shafts 6e and 6e are used as the separation compression springs instead of the coil springs. The other configurations are the same as those in FIGS. 18 and 19. According to this embodiment, similarly to the case shown in FIGS. 16 and 17, the skew waiting of the second sheet material stopped by the mylar 13 can be avoided, and the skew of the next sheet material can be avoided. It becomes possible to prevent transportation. Since the above-mentioned mylar 13 can firmly suppress the second sheet material by the second bent piece 13b at the tip, the effect can be sufficiently obtained with only one mylar 13 at the central portion. You can

21 and 22 show a ninth embodiment of the present invention in which a friction member is used instead of Mylar.
In the ninth embodiment, a pair of plate-shaped friction members 14, on the sheet material guide surface of the apparatus main body 10, on the downstream side of the contact surface 6b between the paper feed rollers 4 on both sides of the inclined member 6. 14
Is provided so as to intersect the tangent line E at an angle β, and the angle β is set to 20 ° to 30 °. Note that other configurations are shown in FIG.
This is similar to the previous fifth and seventh embodiments shown in FIG. With such a configuration, when two sheets of material are conveyed over the contact surface 6b of the inclined member 6, the leading end of the double-fed sheet material collides with the friction member 6 and the conveyance load is increased. Then, the front ends of the two sheet materials are separated and separated. In this case, since the mylar is not used, the sound of flipping the mylar after the sheet material is conveyed can be eliminated.

FIG. 23 shows a tenth embodiment of the present invention in which the above-mentioned friction member 14 is provided on the downstream side of the contact surface 6b in the central portion of the inclined member 6, and other configurations are as follows.
This is similar to the ninth embodiment shown in FIGS. 21 and 22.
According to the tenth embodiment, in the ninth embodiment, the pair of friction members 14 and 14 are arranged at positions that are forward and backward with respect to the sheet material conveyance direction, and the friction members 14 and 14 at the leading end of the sheet material. When the abutting position is moved back and forth, it is possible to avoid the possibility that the second sheet material of the overlapped sheet material is skewed and transported as it is after waiting in a skewed state with respect to the transport direction. It is also possible to use the above-mentioned friction member and mylar together, and it is possible to separate the two sheet materials that could not be separated by either one, and the other can be separated, further reducing the risk of double feeding of sheet materials. be able to.

In the sheet feeding device in which the sheet material separating portion is arranged on the back side of the apparatus main body side with respect to the insertion direction of the cassette as in the above-described first to tenth embodiments, the sheet material is reduced. When the cassette is pulled out for replenishment, the bottom plate under the upward feeding pressure of the compression spring is caught inside the main body of the apparatus and cannot be pulled out. Therefore, as shown in FIG. 59 and FIG. It is necessary to provide a guide rail for pushing down the bottom plate by pulling out the sheet or to take a means for releasing the sheet feeding pressure, which increases the number of parts and tends to increase the size of the apparatus. Further, in such a sheet feeding device, the bottom plate is usually made of a metal plate, and the compression spring is also made of metal, so that it is necessary to ground it. Therefore, it is common to expose the metal plate attached to the bottom of the cassette to the outside of the cassette and connect it to the grounding part of the main body of the cassette.However, the metal plate for grounding may be deformed or contaminated to prevent grounding. There was a risk of incompleteness.

24 to 28 are explanatory views showing the operating state of the eleventh embodiment of the present invention which solves such a point,
FIG. 29 is an exploded perspective view showing the relationship between the detection lever that detects insertion / removal of the cassette and the pressure lever that drives the bottom plate upward. In this eleventh embodiment, the cassette 11
A tip protrusion 11a is provided at the tip of the device, and correspondingly, a base of a detection lever 17 for detecting insertion / removal of the cassette 11 is rotatably attached to the apparatus body 10 side by a support shaft 50. In a state where the pair of arms 17a, 17a bent in the direction of the inclined member 6 are provided on both sides of the free end of the detection lever 17 and the cassette 11 is completely inserted into the apparatus main body 10,
As shown in FIG. 26, the detection lever 17 is pressed by the tip protrusion 11a of the cassette 11 and its arm portions 17a, 17
The positions and shapes of the respective parts are set so that a becomes a position where both sides of the contact surface 6b of the inclined member 6 pass from the left side to the right side in the figure.

The base of the pressure lever 18 is integrally fixed to the center of the support shaft 50 in the longitudinal direction by screwing or the like, and the roller 18a is axially supported by the free end of the pressure lever 18 to support the cassette 11. At the time of insertion into the apparatus main body 10, the roller 18a described above is used.
To be able to sneak into the lower part of the bottom plate 1. Also, the support shaft 5
A pair of torsion springs 51, 51, which are elastic members, are attached between the detection lever 17 and the pressure lever 18 in accordance with 0, and the detection lever 17 and the pressure lever 18 come to a predetermined angular position. When the pressing lever 18 is urged, the roller 1
8a applies a sheet feeding pressure to the bottom plate 1 in the ascending direction.
Note that the other configurations are the same as the configurations shown in FIGS. 1 and 2, but in this embodiment, the pressure lever 18 and the torsion spring 5 that applies an upward biasing force to the pressure lever 18 are used.
By providing 1, 51, the compression spring 3 shown in FIGS. 1 and 2 is omitted.

When the predetermined number of sheets 2 are stacked on the bottom plate 1 with the above-described structure, the bottom plate 1 descends due to its own weight and the weight of the sheet material 2 as shown in FIG. Is kept. In this state, when the cassette 11 is inserted into the apparatus body 10 from the Y direction shown by the arrow, the cassette 11
The front end projection 11a presses the free end side of the detection lever 17 to rotate the detection lever 17 clockwise about the support shaft 50. When the detection lever 17 rotates to the position shown in FIG. 25 and the angle with the pressure lever 18 reaches a predetermined value, the biasing force of the torsion spring 51 begins to be generated and the pressure lever 18 rotates clockwise. The roller 18a contacts the lower surface of the bottom plate 1. When the cassette 11 is completely inserted into the apparatus main body 10 and is in the state shown in FIG. 26, the biasing force of the torsion spring 51 increases and a required sheet feeding pressure is generated. The reference boss on the cassette 11 side (not shown) is fitted into the reference groove on the apparatus main body 10 side, and the cassette 11 is held at the insertion position shown in FIG.

In this state, a series of image formation progresses, the sheet material 2 on the bottom plate 1 decreases, and the state shown in FIG.
When the cassette locking means is released and the cassette 11 is pulled out in the Z direction shown by the arrow for supplementing the sheet material, the tip projection 11
The restraint of the detection lever 17 by a is released, and the torsion spring 5
The biasing force of 1 causes the detection lever 17 to tilt counterclockwise, and the pressing lever 18 also acts on the torsion spring 51.
The urging force due to is eliminated and it rotates counterclockwise due to its own weight, and the bottom plate 1 descends due to its own weight, and the state shown in FIG. 28 is obtained. At this time, the sheet material 2n remaining in front of the nip between the sheet feeding roller 4 and the inclined member 6 is scraped out by the arm portion 17a of the detection lever 17 and placed on the cassette 11.
There is no possibility that the cassette 11 and the cassette 11 are pulled out from the apparatus body 10 and remain inside the apparatus body 1. Further, since the pressure lever 18 itself is formed of a metal plate, it is not necessary to separately ground the pressure unlike the conventional cassette, and the ground connection with the apparatus main body 10 side is easy and reliable.

In the eleventh embodiment, when the cassette 11 is pulled out, the leading edge of the next sheet material is in the state of being nipped between the sheet feeding roller 4 and the tilting member 6, so that depending on the type of sheet material, the detection lever 17 is used. If both sides of the tilting member 6 are scraped out by the arm portions 17a, the sheet material may be broken and the vicinity of the nip portion may remain inside. 30 to 35 show a twelfth embodiment of the present invention which solves the above problems.
FIG. 36 is an exploded perspective view showing a relationship between a detection lever for detecting the insertion / removal of the cassette and a pressure lever for driving the bottom plate upward, which is a cross-sectional view of an essential part showing an operating state of the embodiment.

In the twelfth embodiment, a spring holder 19 having a cross section of a right triangle is provided at the lower portion of the compression spring 5 for applying a separation pressure to the inclined member 6, and a guide pin 19a and a guide groove 10d are provided.
By means of and, the compression spring 5 is slidably mounted in the axial direction, and the common support shaft 50 for the detection lever 17 and the pressure lever 18 is moved to the right in the figure from the eleventh embodiment. A bent portion 17b is provided in a portion of the detection lever 17 near the support shaft 50 so that the bent portion 17b can be brought into contact with and separated from the inclined surface of the spring receiving base 19, and the bent portion 17b serves as a spring pressure varying portion of the compression spring 5. Constitute. The other configurations are the same as those of the eleventh embodiment shown in FIGS. In the twelfth embodiment, in the state shown in FIG. 30 in which the cassette 11 in which the sheet material 2 is stacked on the bottom plate 1 is being inserted into the apparatus main body 10 from the X direction shown by the arrow, the bent portion 17b of the detection lever 17 is not spring-loaded. Since the spring receiving base 19 is lowered to keep the compression spring 5 in the non-compressed state, the contact surface 6b of the inclined member 6 is slightly separated from the sheet feeding roller 4 because it is located away from the slope of the base 19. is there.

In the state shown in FIG. 31 in which the cassette 11 is further inserted from this state, the detection lever 17 is set to the cassette 1
1 is pressed by the front surface of 1 to rotate clockwise, the torsion spring 51 shown in FIG. 36 operates, the pressure lever 18 rotates in the same direction, and the roller 18a contacts the lower surface of the bottom plate 1.
Even in this state, the bent portion 17b of the detection lever 17 is still kept separated from the inclined surface of the spring support 19.
In the state shown in FIG. 32 in which the insertion of the cassette 11 is completed,
The detection lever 17 is further rotated in the clockwise direction, and the bent portion 17b is brought into sliding contact with the inclined surface of the spring receiving base 19 to press the spring receiving base 19 upward, and the biasing force of the compression spring 5 is increased to increase the inclination member. The contact surface 6b of 6 is brought into pressure contact with the paper feed roller 4 to generate a separation pressure. In this state, similarly to the eleventh embodiment, the arm portions 17a, 17a of the detection lever 17 are held at the positions passing both sides of the contact surface 6b of the inclined member 6.

In this state, the sheet material 2 on the bottom plate 1 is reduced to the state shown in FIG. 33. When the cassette 11 is pulled out in the Z direction shown by the arrow to supplement the sheet material, the detection lever 17 is restrained by the cassette 11. When it is released, the detection lever 17 is tilted counterclockwise by the biasing force of the torsion spring 51. As a result, the bent portion 17b is separated from the inclined surface of the spring receiving base 19, the spring receiving base 19 is lowered by the biasing force of the compression spring 5, the biasing force of the compression spring 5 is lost, and the tilting member 6 is lowered by its own weight. The sheet material 2n separated from the paper feed roller 4 and having the leading end nipped is released. At the same time, the rotation of the detection lever 17 in the counterclockwise direction causes the arm portion 1 to move.
7a scrapes sheet material 2n onto cassette 11 and
The state shown in FIG. When the cassette 11 is further pulled out, the biasing force of the torsion spring 51 disappears and the pressure lever 1
8 also rotates counterclockwise, and the bottom plate 1 descends due to its own weight to be in the state shown in FIG. According to the twelfth embodiment, the pressing force of the inclined member 6 can be released with almost no increase in the number of parts, the remaining sheet material 2n can be removed, and the sheet feeding failure can be prevented more reliably. It will be possible.

In the first to twelfth embodiments of the present invention described so far, as shown in FIG.
On the bottom plate 1 whose one end is rotatably supported by the support shaft 1a in the unit 1 and the compression end 3 is engaged with the cassette 11 so that the free end is always biased upward (for example, 500
The sheet feeding device in which the sheet materials 2 (less than one sheet) are stacked has been described. On the other hand, depending on the sheet feeding device, there is also a sheet feeding device having a sheet material stacking member capable of stacking a large amount (for example, 1000 sheets or more) of sheet materials. In such a sheet feeding device, it is difficult to raise the sheet material stacking member by the biasing means including the coil spring as described above because of a large load due to a large amount of sheet material, and normally, a wire is attached to the sheet material stacking member. To drive the motor to a predetermined paper feed position while maintaining the horizontal state by the motor drive, detect the position by the paper surface detection means, and stop the motor drive to hold the sheet material stacking member at that position. It has become.

In this case, in order to generate a sheet material conveying force by the sheet feeding roller, pressure from the sheet feeding roller side is required, and the self-weight of the sheet feeding roller is generally used as this pressing force. With such a configuration, as described in the first embodiment, the sheet material 2 and the inclined member 6 are pressed against one sheet feeding roller 4, and the sheet material is fed between the pressing points A and B. When the constituent requirements of the present invention that regulates the distance X in the direction and the inclination angle θ of the inclined surface 6a of the inclined member 6 with respect to the feeding direction S are applied, an attempt is made to secure the separation pressure Q of the compression spring 5 of the inclined member 6. Therefore, it becomes difficult for the sheet feeding roller 4 to generate a conveying force for the sheet material 2. Therefore, in general, the separation method using the inclined member is abandoned, and the separation method in which the sheet material fed by the paper feed roller is composed of a separation reverse rotation roller and a pair of feed rollers is adopted. 37 to 41
Shows a thirteenth embodiment and a fourteenth embodiment of the present invention, which solves such a problem and enables the present invention to be applied to a paper feeding device loaded with a large amount of this type of sheet material. FIG. 37 is a longitudinal sectional view showing a configuration common to the thirteenth and fourteenth embodiments, FIG. 38 is a plan view of the thirteenth embodiment, FIG. 39 is an exploded perspective view thereof, and FIG. 14
FIG. 41 is a plan view of the embodiment and an exploded perspective view thereof.

In the thirteenth embodiment, FIGS.
As shown in FIG. 5, a separation roller 54, which is separate from the sheet feeding roller 4, is provided at a position B where the sheet feeding roller 4 and the sheet material 2 are brought into pressure contact with the end 6c of the inclined surface of the inclined member 6 downstream of the pressure contact portion A. ing. Then, the separation roller 54 is connected to the apparatus main body 10
As shown in FIG. 38, the separation roller 54 is rotatably supported by a pair of fixed bearings 55, 55 fixed to (FIG. 2), and the sheet material feeding direction (sheet material feeding direction shown in FIGS. 3 to 7). (S is the same as S) and is symmetrical with respect to the center portion of the sheet material conveyance width orthogonal to the center line SC of the sheet material conveyance width. Correspondingly, as shown in FIG.
The tilting member 6 is pivotally supported by e, and the contact surface 6b at the tip thereof is pressed against the separating roller 54 by the compression spring 5 to form a separating portion. Further, a pair of paper feed rollers 4 and 4 are provided on both sides of the separation roller 54, and a pair of movable bearings 57 and 57 (FIG. 38) pivotally pivotally mount the pair of paper feed rollers 4 and 4 on a shaft 56. While supporting and transmitting counterclockwise rotation by a drive motor (not shown) to the sheet feeding rollers 4 and 4 by belt conduction, the sheet material 2 is conveyed by the weight of the sheet feeding rollers 4 and 4 and is conveyed to the separating portion. Is configured as follows. The pair of paper feed rollers 4 and 4 are also arranged symmetrically with respect to the center line SC of the sheet material conveyance width shown in FIG. 38, and other configurations and separation parameters are the same as those in the first embodiment.

With such a structure, a large amount of sheet material 2 raised to a predetermined sheet feeding position by a sheet material stacking member (not shown) is pressed against the pair of sheet feeding rollers 4 and 4 by its own weight, and a pair of sheet feeding rollers 4 and 4 are fed. By rotating the paper rollers 4 and 4 in the counterclockwise direction, a plurality of sheet materials 2 are fed to the separating portion, and separated by the separating roller 54 located in the separating portion and the slanting member 6 in pressure contact with the separating roller 54, one by one. It is transported to the forming unit. According to the thirteenth embodiment, a fixed separation roller 54 is provided only in a sheet feeding device that is equipped with a sheet material stacking member that stacks a large amount of sheet paper and moves up and down by a motor drive while maintaining a horizontal state. It becomes possible to use an inclined member having a simple structure and excellent separation performance in place of a complicated structure composed of a conventional separation reverse rotation roller and a pair of feed rollers,
The number of parts can be reduced.

In the above thirteenth embodiment, the separating roller 54 is made of a rubber material instead of a rubber material, and is generally widely used, such as polyacetal POM, which has high impact resistance, heat resistance, chemical resistance, and weather resistance. It is also possible to use the above synthetic resin material. Even in this case, the feeding force of the uppermost sheet material 2a over the inclined member 6 by the sheet feeding rollers 4 and 4 and the force of feeding the next sheet material 2b by the frictional force with the uppermost sheet material 2a are There is no difference from the case of the first embodiment, and the distance X between the pressure contact portion A between the sheet material 2 and the sheet feeding roller 4 and the pressure contact portion B between the inclined member 6 and the separation roller 54.
Can be set to be equal to the value of the distance X shown in FIG. 7, and good separation quality of the sheet material can be maintained,
At the same time, the cost of the separating roller can be reduced by reducing the cost of parts.

Next, a fourteenth embodiment of the present invention will be described with reference to FIG.
As shown in FIG. 0 and FIG. 41, the sheet feeding roller 4 is supported at the center of the sheet material conveying width by the swingable movable bearings 57, 57 whose one end is pivotally supported by the shaft 56, and a pair of inclinations is provided on both sides thereof. The members 6 and 6 are provided, and the inclined members 6 and 6 are provided.
Corresponding to the pair of separating rollers 54, 54 are rotatably supported by a pair of fixed bearings 55, 55, respectively. The pair of separating rollers 54, 54 are provided on both sides of the sheet feeding roller 4.
All 54 are provided symmetrically with respect to the center line SC of the sheet material conveyance width. Note that the other configurations and operations are the same as those of the first
This is similar to the third embodiment, and in the case of the fourteenth embodiment as well, the material of the separation roller 54 can be a synthetic resin material. In the fourteenth embodiment as described above, the inclination member 6 and the separation roller 54 are provided at two places respectively,
If the material of the separation roller 54 is synthetic resin material, the paper feed roller 4 having a rubber material can be provided at one place, so that the parts cost of the entire apparatus can be reduced. In the thirteenth and fourteenth embodiments as well, the paper feeding roller that is in pressure contact with the inclined member 6 is read as a separation roller, so that the above-described second to twelfth embodiments of the present invention can be applied without any trouble. It will be possible.

In the above-described first to fourteenth embodiments, the case where a plurality of sheet materials 2 are stacked on the bottom plate 1 in a substantially horizontal state in the paper feeding cassette has been described. There is also a paper feeding device in which the sheet is inclinedly provided on the back surface of the image forming apparatus. FIG. 42 is a cross-sectional view of a principal part showing a fifteenth embodiment of the present invention for this type of paper feeding device, FIG. 43 is a perspective view thereof, and FIG. 44 is a perspective view showing the inclined member. In the fifteenth embodiment, the restraining ribs 1b and 1b are integrally provided on both sides of the front end portion of the bottom plate 1, and correspondingly, the first cams 21 and 21 are attached to the rotary shaft 20 of the sheet feeding roller 4.
And the second cams 22, 22 are fixed on both sides of the paper feed roller 4 of the rotary shaft 20. The tilting member 26 rotatably supported by the support shaft 26e has a contact surface 26b at its tip end contacting the sheet feeding roller 4 by the urging force of the compression spring 5, and the sheet feeding roller is located downstream of the contact surface 26b. 4 is formed with a recessed portion 26f, and ribs 26g, 26 which can contact the second cams 22, 22 are formed on both side portions thereof.
forming g. Further, a spring clutch portion 23 capable of interrupting the rotation of a drive motor (not shown) is provided at one end (the right end portion in FIG. 43) of the rotary shaft 20 and is intermittently controlled by a solenoid 24 so that one rotation control can be performed.
42 can be rotationally driven clockwise in FIG.

45 to 50 show the operating state thereof, and FIG. 50 shows the sheet feed standby state. The bottom plate 1 and the inclined member 26 are separated from the paper feed roller 4 by the first and second cams 21 and 22 against the biasing forces of the compression springs 3 and 5, respectively. When the sheet feeding is started and the sheet feeding roller 4 is rotated in the clockwise direction, the first and second cams 2 are synchronized therewith.
1, 2 and 22 also start to rotate, and first, as shown in FIG.
The top dead center of the cam 22 is separated from the tilting member 26, and the tilting member 26 comes into contact with the sheet feeding roller 4. Then, as shown in FIG. 47 through the state shown in FIG. 46, the top dead center of the first cam 21 separates from the restraining rib 1b of the bottom plate 1 and the bottom plate 1 swings in the direction of the sheet feeding roller 4, so that the bottom plate 1 The sheet material (not shown) stacked on the sheet is conveyed to the inclination member 26, and the uppermost sheet material is separated and conveyed to the conveying roller pair 7. here,
As shown in FIG. 48, the first cam 21 again comes into contact with the restraining rib 1b of the bottom plate 1 to swing the bottom plate 1 in the counterclockwise direction, and then the second cam 22 moves the tilting member as shown in FIG. 26
After abutting against and swinging in the clockwise direction, the standby state shown in FIG.

In this way, the second member is provided on both sides of the tilting member 26.
The ribs 26g, 26g capable of contacting the cam 22 are provided, and the tilting member 26 is pushed down by one rotation of the sheet feeding roller 4 to separate the sheet material in the sheet feeding standby state (the sheet material conveying state by the conveying roller pair 7). When the rear sheet feeding roller 4 is rotated together, the sheet material is conveyed between the second cam 22 and the ribs 26g and 26g of the inclination member 26, and the contact surface 26b of the inclination member 26 and the sheet material are rubbed against each other. It is possible to reduce the risk that the contact surface 26b will be worn. First mentioned above
When setting a large number of sheet materials in the fifth embodiment,
If the tip ends are not uniform, there is a possibility that the sheet material cannot be set in the lower part of the paper feed roller 4.

FIG. 51 is a perspective view showing a tilting member restraining plate 25 provided between the second cam 22 and the tilting member 26 to solve the above problem. The pair of bearing portions 25a, 25a are pivotally supported on the shaft 27 of the opposing roller 7b of the conveying roller pair 7 shown in FIG. 52, and the part where the sheet feeding roller 4 and the inclined member 26 are in contact with each other is escaped to the middle portion in the longitudinal direction. The opening 25b is provided. The rest of the configuration is the same as in the previous 15th embodiment. In the sixteenth embodiment having such a configuration, FIG. 57 shows a paper feed standby state, in which the first cam 21 presses the holding rib 1b of the bottom plate 1 and the second cam 22 holds the inclined member holding plate 25. The ribs 26g of the tilting member 26 are pressed through the bottom plate 1 and the tilting member 26 so as to be separated from the sheet feeding roller 4. The free end portion of the inclined member restraining plate 25 is located upstream of the sheet feeding roller 4 and widens in the sheet material insertion direction between itself and the bottom plate 1. This makes it possible to reliably set the sheet material on the lower portion of the paper feed roller 4 even if the leading ends of a large number of sheet materials vary.

When paper feed is started from the state shown in FIG. 57 and the paper feed roller 4 rotates clockwise, the first and second cams 21 and 22 also start to rotate in synchronization therewith, and first shown in FIG. As described above, the top dead center of the second cam 22 is disengaged from the inclination member restraining plate 25, and the inclination member 26 abuts on the sheet feeding roller 4. Further, as shown in FIG. 54 through the state shown in FIG. 53, the top dead center of the first cam 21 is separated from the restraining rib 1b of the bottom plate 1, and the bottom plate 1 swings in the direction of the paper feed roller 4 to move to the bottom plate. The sheet material stacked on No. 1 is conveyed to the inclination member 26, and the uppermost sheet material is separated and conveyed to the conveying roller pair 7. Here, as shown in FIG. 55, the first cam 21 is replaced by the bottom plate 1 again.
After the bottom plate 1 is swung counterclockwise by abutting against the restraining rib 1b, the second cam 22 abuts the tilting member restraining plate 25 and swings clockwise as shown in FIG. It will be in the standby state shown. In this way, between the tilting member 26 and the second cam 22, the tilting member restraining plate 25 which escapes the portion where the contact surface 26b of the feeding roller 4 and the tilting member 26 abuts is provided, and the tip thereof is fed. By locating the sheet material upstream of the paper roller 4, it becomes possible to reliably set a large number of sheet materials having different leading ends to the lower portion of the paper feed roller 4 by being guided to the inclined member restraining plate 25.

Next, FIG. 58 is a block diagram of a copying machine which is an example of an image forming apparatus having the above-described paper feeding device. The copying machine 30 includes an optical reading system 3 provided in a copying machine main body 31.
Optical writing system 3 based on the image data read by 2
3 forms a latent image on the photoconductor 35 provided in the image forming system 34,
The developing device 36 of the image forming system 34 forms the latent image into a visible image with toner. The above-mentioned paper feeding device P is provided below the main body of the copying machine 31, and the sheet material 2 stacked on the bottom plate 1 is fed from the cassette 11 of the paper feeding device P one by one by the paper feeding roller 4. , The transport path 37 by the transport roller pair 7.
The image is conveyed to the image forming system 34 through the sheet, and the visible image on the photoconductor 35 is transferred onto the sheet material 2.

When the transfer is completed, the sheet material 2 is conveyed to the fixing device 38 to fix the visible image, and then discharged to the external discharge tray 40 by the discharge roller pair 39. Further, at the time of double-sided image formation, the sheet material 2 is conveyed from the reverse conveyance path 41 to the double-sided device 42 by a sheet discharge branching claw not shown,
After being temporarily stored in the double-sided tray 43, the traveling direction is reversed, the sheet is fed again from the double-sided transport path 44 to the image forming system 34, an image is formed on the back side, and the sheet is discharged onto the sheet discharge tray 40 through the fixing device 38. It Although only one sheet feeding device P is shown in FIG. 58 for simplification of the drawing, it is possible to provide a plurality of sheet feeding devices of different sizes as necessary, and this sheet feeding device P can be provided. The image forming apparatus having the apparatus is not limited to the copying machine, but can be applied to a facsimile, a printer, etc. without any trouble.

[0062]

As described above, according to the present invention, the following effects can be obtained. According to the paper feeding device of the first aspect, even if the leading edge of the sheet material can be a carrying load at the time of paper feeding, since there is no friction member, the sheet is not caught by the separating portion, and no feeding occurs. That's not it. Further, even if there is a large variation in the coefficient of friction between the stacked sheet materials, the next sheet material does not get over the inclined member due to the frictional force of the preceding sheet material, so that double feeding does not occur. It is possible to improve the quality of feeding and conveying. Further, the nip portion of the sheet material between the sheet feeding roller and the tilting member becomes small, and after the trailing edge of the leading sheet material passes through the sheet feeding tray nip, the sheet feeding roller causes friction due to friction with the leading sheet material. It is possible to suppress the double feeding of the sheet material due to the entrainment and to maintain the good transportation quality for a long time.

According to the paper feeding apparatus of the second aspect, the tilting member is pressed against the paper feeding roller so that it can swing freely. Therefore, the method of supporting the tilting member and the method of urging the paper feeding roller are extremely simple and reliable. Can be configured to. According to the paper feeding device of the third aspect, since the tilting member advances and retracts in parallel with the paper feeding roller, even when the contact surface of the tilting member with the paper feeding roller is worn due to friction with the sheet material. The angle of the inclined surface with respect to the sheet material feeding direction can always be kept at a predetermined value. According to the paper feeding device of the fourth aspect, the tilting member is surely parallel to the paper feeding roller with a very simple structure in which one of the tilting member and the apparatus main body is provided with a rib and the other is provided with a guide rail. It can be moved. According to the paper feeding device of the fifth aspect, since the length of the contact surface of the inclined member is smaller than the length of the paper feeding roller in the axial direction,
The friction with the sheet material causes the contact surface to be worn in a straight line on average over the entire length, and there is no fear that the conveyance load increases at the contact surface and the sheet material is not fed.

According to the paper feeding apparatus of the sixth aspect, since the tilting member is made of synthetic resin and at least the contact surface with the paper feeding roller is covered with the metal plate, tilting due to friction with the sheet material is performed. The wear of the member can be significantly reduced, and the inclined member having a complicated shape can be produced at low cost. According to the sheet feeding device of the seventh aspect, since the metal plate covering the inclined member has elasticity, the metal plate can be firmly mounted on the inclined member by its own elasticity. According to the paper feeding device of the eighth aspect, since the elastic metal plate is attached from the inclined surface side so as to hold the inclined member from both upper and lower surfaces, the attachment to the inclined member can be performed by one operation. The operability is extremely good, and since the metal plate is pressed in the direction in which the metal plate comes into close contact with the inclined member after the sheet material is conveyed, there is no possibility that the mounting position is displaced.

According to the paper feeding device of the ninth aspect, the influence of the bending elastic coefficient of the sheet material to be used is drastically reduced by bringing the distance between the sheet material which is in pressure contact with the sheet feeding roller and the pressure contact member of the inclined member close to each other. Therefore, it is possible to handle various sheet materials without increasing the number of parts. According to the paper feeding device of the tenth aspect, since the thin plate elastic member that intersects the tangential direction of the abutting portion is provided downstream of the abutting portion between the paper feeding roller and the inclined member, two sheet materials are temporarily provided. Even when the sheet is conveyed over the abutting surface of the inclined member, it is possible to prevent the double feed by blocking the second sheet material due to the load of bending the thin plate elastic member by these sheet materials. .

According to the paper feeding apparatus of the eleventh aspect, since the thin plate elastic members are provided on both sides of the paper feeding roller,
The elastic force of each thin plate elastic member can be weakened to prevent damage to the leading end of the sheet material, while ensuring the double feed prevention effect. According to the paper feeding device of the twelfth aspect, since the thin plate elastic member is provided substantially in the center of the paper feeding roller, the second sheet material can be stopped at one central point.
It is possible to prevent skew waiting of the sheet material and skew conveyance associated therewith. According to the paper feeding device of claim 13,
A thin plate elastic member having a hook-shaped bent portion at the rear end, which intersects the tangential direction of this contact portion and is bent toward the paper feed roller, is provided downstream of the contact portion between the paper feed roller and the inclined member. Therefore, it has passed over the abutting part between the paper feed roller and the inclined member.
The leading edge of the sheet of paper hits the hook-shaped bent portion of the thin plate elastic member and becomes a transport load, and is separated one by one.

According to the sheet feeding device of the fourteenth aspect, since the thin plate elastic members are provided on both sides of the sheet feeding roller, the elastic force of each thin plate elastic member is weakened to prevent the leading end portion of the sheet material from being damaged. The effect of preventing double feeding of sheet materials can be enhanced.
According to the paper feeding device of the fifteenth aspect, since the thin plate elastic member is provided substantially at the center of the paper feeding roller, the second sheet material can be dammed at one central point, and the sheet material is skewed and waits. Therefore, it is possible to prevent the skew conveyance. According to the paper feeding device of the sixteenth aspect, the thin plate elastic member is 20 in the tangential direction of the contact portion between the paper feeding roller and the inclined member.
By intersecting at 60 ° to 60 °, it is possible to effectively prevent double feeding of all sheet materials from thin sheet material to thick rigid sheet material.

According to the paper feeding apparatus of the seventeenth aspect, since the friction member which intersects with the tangential direction of the abutting portion is provided downstream of the abutting portion between the paper feeding roller and the inclined member, two sheets are provided. It is possible to further improve the effect of separating the material, and it is possible to reduce the noise by eliminating the sound of flipping the thin elastic member when the sheet material is conveyed. According to the paper feeding device of the eighteenth aspect, since the friction members are provided on both sides of the paper feeding roller, the frictional force of each friction member is weakened to prevent the leading edge of the sheet material from being fed in duplicate. The prevention effect can be improved. According to the paper feeding device of claim 19,
Since the friction member is provided almost at the center of the paper feed roller, the second sheet material can be stopped at one central location, and it is possible to prevent the skew waiting of the sheet material and the accompanying skew feeding. Become.

According to the paper feeding apparatus of the twentieth aspect, a pressure lever that can be brought into and out of contact with the sheet material stacking member and a detection lever that rotates when the cassette is inserted and removed are provided coaxially, and an elastic member is provided between the levers. Since the sheet feeding device has the sheet material separating section disposed on the rear side of the apparatus main body, the drawer of the cassette and the lowering of the sheet material stacking member can be interlocked with a very simple configuration. At the same time, it is possible to reduce the size of the device. At the same time, since the pressure lever itself is made of a metal plate, it is possible to easily make a ground connection with the apparatus main body side. According to the paper feeding device of the twenty-first aspect, when the angle between the pressure lever and the detection lever becomes larger than a predetermined angle, both levers are interlocked to rotate, so that the number of parts is reduced. The sheet material stacking member can be automatically and surely lowered by pulling out the cassette without increasing the number.

According to the paper feeding apparatus of the twenty-second aspect, since the free end portion of the detection lever can pass both sides of the contact surface of the inclined member, the leading end portion is nipped before the cassette is pulled out. The sheet material can be scraped out on the cassette. At this time, since the sheet feeding pressure of the sheet material stacking member is released before the detection lever operates to scrape out the sheet material, the sheet material can be easily scraped. According to the paper feeding device of claim 23, the detection lever is provided with a spring pressure variable portion that can adjust the biasing force of the compression spring that presses the tilting member against the paper feeding roller. Since the pressing force of the member to the paper feed roller is also released, the sheet material whose front end is nipped becomes free and can be easily removed on the cassette by the rotation of the detection lever. According to the paper feeding apparatus of claim 24, the spring pressure varying portion is engaged with and disengaged from the spring pedestal slidably provided on the side opposite to the inclined member of the compression spring. With such a configuration, it becomes possible to change the spring pressure in association with the insertion / removal of the cassette.

According to the twenty-fifth aspect of the present invention, for example, even if the sheet material is inclined and there is a risk of skew in the conventional sheet feeding apparatus or the drive motor is overloaded, the sheet material is The skew feeding can be prevented, and at the same time, the first cam provided coaxially with the sheet feeding roller separates the sheet material stacking member from the sheet feeding roller for each sheet feeding, thereby acting on the drive motor. It becomes possible to reduce the load. According to the paper feeding device of the twenty-sixth aspect, since the sheet material stacking member is provided with the restraining rib with which the first cam can abut, the sheet material stacking member can be sufficiently provided without enlarging the first cam. It can be pushed down, and the lateral displacement of the sheet material can be effectively prevented.

According to the paper feeding apparatus of the twenty-seventh aspect, by providing the second cam that is in contact with both side ends of the tilting member coaxially with the paper feeding roller, the tilting member is fed every time one sheet is fed. When the sheet feeding roller is rotated after being separated from the roller and the sheet material is separated, the contact surface of the inclined member does not rub against the sheet material, and the abrasion of the contact surface of the inclined member is reduced to improve durability. It will be possible to improve. According to the paper feeding apparatus of the twenty-eighth aspect, the inclined member is provided with ribs on both side ends thereof to which the second cam can abut, so that the inclined member can be reinforced and its deformation can be prevented. According to the paper feeding device of claim 29, a tilting member restraining plate is provided between the second cam and the tilting member so that the leading end of the tilting member restraining plate is expanded from the sheet material stacking member. When setting the sheet material, it becomes possible to easily set the sheet material under the sheet feeding roller even if the leading end of the sheet material varies.

According to the sheet feeding apparatus of the thirtieth aspect, a large number of sheet materials are stacked, the rising is stopped at the sheet feeding position, and the sheet feeding roller is pressed against the uppermost sheet material. In the above, a separating roller, which is in pressure contact with an inclined member, is provided at a fixed axial position separately from the sheet feeding roller, and the sheet feeding roller and the separating roller are provided at different positions of the sheet material conveying width and the sheet material. Since they are arranged symmetrically with respect to the center line of the conveyance width, the separation pressure of the inclined member does not act on the paper feed roller. Therefore, even in a sheet feeding device loaded with such a large amount of sheet materials, a reverse rotation roller is not required in the sheet material separating portion, and a simple and reliable configuration of the separating roller and the inclined member that presses against the separating roller is used. It is possible to improve the separation quality and reduce the number of parts. According to the paper feeding apparatus of the thirty-first aspect, since the separating roller is arranged at the center of the sheet material conveying width and the paper feeding rollers are arranged on both sides of the separating roller, the sheet material feeding pressure is increased and various types are provided. It is possible to reliably convey various sheet materials.

According to the paper feeding apparatus of the thirty-second aspect, since the paper feeding roller is arranged at the center of the sheet material conveying width and the separation rollers are arranged on both sides of the paper feeding roller respectively, the separation pressure of the sheet material is increased. It is possible to maintain good separation quality.
According to the paper feeding apparatus of the thirty-third aspect, since the material of the separating roller is the synthetic resin material, the parts cost can be reduced without impairing the separating quality of the sheet material. According to the image forming apparatus of claim 34, it is possible to reliably separate sheet materials of various types from one by one without feeding or double feeding, and to feed the sheet material to the image forming section. Will be possible.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the overall structure of the same.

FIG. 3 is an explanatory diagram showing a part of FIG. 1 in an enlarged manner.

FIG. 4 is an explanatory view showing a force relationship of the uppermost sheet material.

FIG. 5 is an explanatory view showing a force relationship of the next sheet material.

FIG. 6 is an explanatory view showing a worn state of the inclined member.

FIG. 7 is an explanatory view showing the relationship between the sheet feeding roller and the tilting member.

FIG. 8 is an exploded perspective view showing a length relationship between the sheet feeding roller and the inclined member.

FIG. 9 is a vertical sectional view of the same.

FIG. 10 is an exploded perspective view showing a main part of the second embodiment of the present invention.

FIG. 11 is an exploded perspective view showing a main part of a third embodiment of the present invention.

FIG. 12 is a sectional view showing a mounting state of the inclined member and the elastic metal plate.

FIG. 13 is a vertical sectional view showing a fourth embodiment of the present invention.

FIG. 14 is a vertical sectional view showing a fifth embodiment of the present invention.

FIG. 15 is an exploded perspective view of the main part of the same.

FIG. 16 is a vertical sectional view showing a sixth embodiment of the present invention.

FIG. 17 is an exploded perspective view of the main part of the same.

FIG. 18 is a vertical sectional view showing a seventh embodiment of the present invention.

FIG. 19 is an exploded perspective view of the main part of the same.

FIG. 20 is an exploded perspective view showing a main part of an eighth embodiment of the present invention.

FIG. 21 is a vertical sectional view showing a ninth embodiment of the present invention.

FIG. 22 is an exploded perspective view of the main part of the same.

FIG. 23 is an exploded perspective view showing the main parts of the tenth embodiment of the present invention.

FIG. 24 is an explanatory diagram showing a first operating state at the time of inserting the cassette according to the eleventh embodiment of the present invention.

FIG. 25 is an explanatory diagram showing a second operating state of the same.

FIG. 26 is an explanatory view showing a state when the cassette insertion is completed similarly.

FIG. 27 is an explanatory diagram showing a first operating state when the cassette is pulled out.

FIG. 28 is an explanatory diagram showing a second operating state of the same.

FIG. 29 is an exploded perspective view showing the relationship between the detection lever and the pressure lever of the same.

FIG. 30 is an explanatory diagram showing a first operating state at the time of inserting the cassette according to the twelfth embodiment of the present invention.

FIG. 31 is an explanatory diagram showing a second operating state of the same.

FIG. 32 is an explanatory diagram showing a state at the time when the insertion of the cassette is completed.

FIG. 33 is an explanatory diagram showing a first operating state when the cassette is pulled out.

FIG. 34 is an explanatory diagram showing a second operating state of the same.

FIG. 35 is an explanatory diagram showing a third operating state of the same.

FIG. 36 is an exploded perspective view showing the relationship between the detection lever and the pressure lever of the same.

FIG. 37 is a vertical cross-sectional view showing the main parts common to the configurations of the thirteenth and fourteenth embodiments of the present invention.

FIG. 38 is a plan view showing an arrangement example of the paper feed roller and the separation roller according to the thirteenth embodiment of the present invention.

FIG. 39 is an exploded perspective view showing the same structure.

FIG. 40 is a plan view showing an arrangement example of the paper feed roller and the separation roller according to the fourteenth embodiment of the present invention.

FIG. 41 is an exploded perspective view showing the same structure.

FIG. 42 is a vertical cross-sectional view showing the main parts of the fifteenth embodiment of the present invention.

FIG. 43 is a perspective view of the same.

FIG. 44 is a perspective view showing the tilting member of the same.

FIG. 45 is an explanatory diagram showing a first operating state of the same.

FIG. 46 is an explanatory diagram showing a second operating state of the same.

FIG. 47 is an explanatory diagram showing a third operating state of the same.

FIG. 48 is an explanatory diagram showing a fourth operating state of the same.

FIG. 49 is an explanatory diagram showing a fifth operating state of the same.

FIG. 50 is an explanatory diagram showing a paper feed standby state of the same.

FIG. 51 is a perspective view showing an inclined member restraining plate according to a sixteenth embodiment of the present invention.

FIG. 52 is an explanatory diagram showing a first operating state of the sixteenth embodiment.

FIG. 53 is an explanatory diagram showing a second operating state of the same.

FIG. 54 is an explanatory diagram showing a third operating state of the same.

FIG. 55 is an explanatory diagram showing a fourth operating state of the same.

FIG. 56 is an explanatory diagram showing a fifth operating state of the same.

FIG. 57 is an explanatory diagram showing a paper feed standby state of the same.

FIG. 58 is a configuration diagram illustrating an example of an image forming apparatus including the paper feeding device.

FIG. 59 is a vertical sectional view showing an example of a conventional paper feeding device.

FIG. 60 is an explanatory diagram showing a cassette withdrawn state in the same manner.

[Explanation of symbols]

1: Bottom plate (sheet material stacking member) 2: Sheet material 3: Compression spring 4: Paper feed roller 5: Compression spring 6, 26: Inclined member 7: Pair of transport rollers 8: Guide rail 9: Elastic metal plate 9 ': Metal plate 10: Device body 11: Cassette 12, 13: Thin plate elastic member (mylar) 14: Friction member 15: Torsion spring 17: Detection lever 18: Pressure lever 19: Spring pedestal 20: rotation axis of paper feed roller 21: first cam 22: Second cam 25: Inclined member restraining plate 30: Copier (image forming apparatus) 31: Copier body 50: Spindle 54: Separation roller 55: Fixed bearing 57: Movable bearing A: Pressure contact area between the sheet material on the bottom plate and the paper feed roller B: Pressure contact area between the inclined member and the paper feed roller S: Sheet material feeding direction E: A tangent line of the contact portion between the sheet feeding roller and the inclined member X: Distance between the pressure contact parts A and B Y: cassette insertion direction Z: cassette drawer direction

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) B65H 3/52 B65H 3/52 330M 1/24 1/24 J 1/26 314 1/26 314A 3/56 330 3/56 330E G03G 15/00 516 G03G 15/00 516 (31) Priority claim number Japanese Patent Application 2001-79040 (P2001-79040) (32) Priority date March 19, 2001 (March 19, 2001) ) (33) Priority claim country Japan (JP) (31) Priority claim number Japanese Patent Application No. 2001-142313 (P2001-142313) (32) Priority date May 11, 2001 (May 11, 2001) (33) ) Japan (JP) F-term (reference) 2H072 AB07 BA03 BA12 CA01 CA02 3F343 FA02 FB02 FB03 FC01 GA03 GB01 GC01 GD01 HA31 HB03 HC04 HC26 HD08 HD18 JA01 JD02 JD07 JD08 JD09 J20 KB18 KA05 KB18 KA06 KB18 KA06 KB16 KB17 LA04 LA15 LC11 LC12 LC20 LD26 MB 04 MB10 MB14 MC10 MC20

Claims (34)

[Claims] 1. A sheet feeding device for feeding sheet materials stacked on a swingable sheet material stacking member separately from the uppermost sheet material, and feeding the sheet material by pressing the uppermost sheet material. A sheet feeding roller for feeding the sheet material to the separating portion and an inclined member provided with an inclined surface that is in pressure contact with the sheet feeding roller and abuts a front end of the sheet material in the sheet feeding direction are provided. A sheet feeding device, characterized in that a contact surface with is formed as a protrusion along the axial direction of the sheet feeding roller. 2. The inclining member is movably pressed against the paper feeding roller.
The paper feeder described. 3. The sheet feeding device according to claim 1, wherein the tilting member includes a parallel moving unit that advances and retracts in parallel with the sheet feeding roller. 4. The sheet feeding apparatus according to claim 3, wherein the parallel moving means includes a rib provided on one of the tilting member and the apparatus main body and a guide rail provided on the other side. 5. The sheet feeding device according to claim 1, wherein a length of a contact surface of the inclined member is smaller than a length of the sheet feeding roller in an axial direction. 6. The inclined member is molded of synthetic resin,
The sheet feeding apparatus according to claim 1, wherein at least a contact surface with the sheet feeding roller is covered with a metal plate. 7. The sheet feeding device according to claim 6, wherein the metal plate that covers the inclined member has elasticity. 8. The sheet feeding device according to claim 7, wherein the elastic metal plate is mounted from the inclined surface side so as to hold the inclined member from both upper and lower surfaces. 9. The sheet feeding apparatus according to claim 1, wherein the sheet material stacked on the inclined member and the sheet material stacking member is pressed between the sheet feeding rollers. 2m along the sheet material transport direction
The sheet feeding device is characterized in that the angle is set to m to 6 mm and the angle of the inclined surface of the inclined member with respect to the sheet material conveying direction is set to 50 ° to 70 °. 10. The sheet feeding device according to claim 1, wherein a thin plate elastic member that intersects with a tangential direction of a corresponding contact portion is provided downstream of the contact portion between the paper feed roller and the inclined member. A sheet feeding device characterized in that a member is provided. 11. The sheet feeding device according to claim 10, wherein the thin plate elastic members are provided on both sides of the sheet feeding roller. 12. The sheet feeding device according to claim 10, wherein the thin plate elastic member is provided substantially in the center of the sheet feeding roller. 13. The sheet feeding device according to claim 1, wherein a trailing end of the sheet feeding roller and the inclined member intersects in a tangential direction of a corresponding contact portion downstream of the contact portion. A sheet feeding device, characterized in that a thin plate elastic member having a hook-shaped bent portion bent in the direction of the sheet feeding roller is provided in the portion. 14. The paper feeding device according to claim 13, wherein the thin plate elastic members are provided on both sides of the paper feeding roller. 15. The sheet feeding device according to claim 13, wherein the thin plate elastic member is provided substantially in the center of the sheet feeding roller. 16. The sheet feeding device according to claim 13, wherein the thin plate elastic member intersects the tangential direction at 20 ° to 60 °. 17. The sheet feeding device according to claim 1, wherein a friction member that intersects a tangential direction of a corresponding contact portion is provided downstream of a contact portion between the sheet feed roller and the inclined member. A paper feeding device characterized by being provided with. 18. The paper feeding device according to claim 17, wherein the friction members are provided on both sides of the paper feeding roller. 19. The paper feeding device according to claim 17, wherein the friction member is provided substantially at the center of the paper feeding roller. 20. The sheet feeding device according to claim 1, wherein a pressure lever whose free end can be brought into contact with and separated from the sheet material stacking member, and a shaft coaxial with the pressure lever. A detection lever that rotates in association with insertion / removal of the attached cassette having the sheet stacking member, and an elastic member that is engaged between the detection lever and the pressure lever are provided. Paper feeder. 21. The pressure lever is adapted to be rotatable in conjunction with the detection lever when the angle with the detection lever becomes larger than a predetermined angle. Paper feeder. 22. The detection lever is provided with a pair of arm portions extending on both sides of the inclined member at its free end portion,
22. The paper feeding device according to claim 20, wherein the arm portion can pass on both sides of the contact surface of the inclined member by rotating the detection lever. 23. The detection lever is provided with a spring pressure varying portion capable of adjusting the urging force of a compression spring that presses the inclined member against the sheet feeding roller in the previous period. The paper feeding device according to the item 1. 24. The spring pressure varying portion is engaged with a spring pedestal provided on the opposite side of the compression spring to the inclined member so as to be slidable in the axial direction of the compression spring by the rotation of the detection lever. 24. The paper feeding device according to claim 23, wherein the spring pedestal can be driven in the direction of the inclined member by being disengaged and engaged. 25. The sheet feeding device according to claim 1, wherein the sheet material stacking member is in contact with both side ends of a leading end portion of the sheet material stacking member coaxially with the sheet feeding roller. A sheet feeding device comprising a first cam for separating a member from the sheet feeding roller. 26. The sheet feeding device according to claim 25, wherein the sheet material stacking member is provided with restraining ribs at both ends of the leading end portion thereof, with which the first cam can come into contact. 27. The sheet feeding device according to claim 25, wherein the second cam is coaxial with the sheet feeding roller and is in contact with both ends of the inclined member to separate the inclined member from the sheet feeding roller. A paper feeding device characterized by being provided with. 28. The paper feeding device according to claim 27, wherein the tilting member is provided with ribs on both ends thereof, with which the second cam can abut. 29. The sheet feeding device according to claim 27, wherein an inclined member restraining member is provided between the second cam and the inclined member so as to escape a portion where the sheet feeding roller and the inclined member come into contact with each other. A sheet feeding device, characterized in that a plate is provided, and a front end portion of the plate is expanded from the sheet material stacking member upstream of the sheet feeding roller. 30. A large amount of sheet material stacked on a sheet material stacking member that rises and falls while maintaining a horizontal state is raised to a predetermined paper feeding position and held at that position, one by one from the uppermost sheet material. In a sheet feeding device that separates and feeds, a sheet feeding roller that presses the uppermost sheet material and feeds the sheet material to a separating section, and a separating roller that is provided in the separating section with an axial position fixed. An inclined member is provided, which is in pressure contact with the separation roller and abuts a front end of the sheet material in the feeding direction, and an inclination member in which a contact surface with the separation roller is formed as a ridge extending in the axial direction of the separation roller is provided. A sheet feeding device, wherein the sheet feeding roller and the separation roller are arranged at positions different from each other in the sheet material conveying width and symmetrically with respect to a center line of the sheet material conveying width. 31. The sheet feeding device according to claim 30, wherein the separating roller is arranged at the center of the sheet material conveying width, and the sheet feeding roller is arranged on both sides of the separating roller. 32. The paper feeding apparatus according to claim 30, wherein the paper feeding roller is arranged at the center of the sheet material conveying width, and the separation rollers are arranged on both sides of the paper feeding roller. 33. The paper feeding device according to claim 31, wherein the material of the separating roller is a synthetic resin material. 34. An image forming apparatus comprising: the sheet feeding device according to claim 1; and an image forming unit that forms an image on a sheet material fed from the sheet feeding device.