JP2001010731A - Paper sheet feeding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent generation of overlapping feeding caused by a change in number of sheets of paper to be stored and paper sheet feeding defectives by always actuating substantially constant energizing force on a loading plate and paper sheet, regardless of a change in increase or decrease of number of sheets of paper to be stored. SOLUTION: In this device, a loading plate 32 on which a paper sheet P is mounted is journalled at an upstream side end part of a paper sheet feeding direction and a guide plate 30 journalled by an intermediate part 30b of the paper sheet feeding direction is arranged on an upper side of the loading plate 32, within a body of equipment 31 of a paper sheet feeding cassette 20. In the guide part 30, an abutting roller 30a is supported at an upstream side end part of the paper sheet feeding direction and a locking part 30c is formed at a downstream side end part. On the locking part 30c, a state of a tension spring 33 with a lower end locked on the loading plate 30 is locked. An inclined angle of the guide plate 30 is changed according to the number of sheets of paper P to be stored, space of the locking part 30c and the loading plate 32 is made substantially constant, regardless of the number of sheets of paper P to be stored, and elastic force Ka, Kb of the tension spring 33 is made substantially constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a sheet processing apparatus which performs a predetermined process on a sheet in a processing section, such as an image forming apparatus such as a copying machine or a printer, and supplies a plurality of sheets. The present invention relates to a sheet feeding device that feeds sheets one by one from a paper unit to a processing unit.

[0002]

2. Description of the Related Art In an image forming apparatus for performing an image forming process on a sheet, a sheet cassette storing a plurality of sheets in consideration of easiness of replacement and replenishment of a sheet to be fed to an image forming processing unit. Is detachably attached to the paper feeding unit. As shown in FIG. 5, a conventional paper feed cassette 50 includes a stacking plate 52, a pressing spring 53, and a separation claw 54 in a housing 51 opened to the upper surface.
And a front end guide 55 and a rear end guide 56 including

[0005] The loading plate 52 is provided inside the housing 51.
The upstream end in the sheet feeding direction is pivotally supported. This loading plate 5
A predetermined number of sheets P are placed on the upper surface of the sheet 2. Press spring 5
Reference numeral 3 denotes a compression coil spring, for example.
The stacking plate 52 is urged upward so that the upper surface of the sheet comes into contact with the sheet feeding roller 61 of the image forming apparatus with a predetermined pressing force when the sheet No. 0 is attached to the sheet feeding section of the image forming apparatus. Separation claw 54
Separates one sheet to be fed from another sheet when feeding a sheet. The front end guide 55 defines a front end position of the sheet in the sheet cassette 50. Also, the rear end guide 5
Reference numeral 6 designates the position of the rear end of the sheet in the sheet cassette 50.

In the paper feed cassette 50 configured as described above, the paper P placed on the upper surface of the loading plate 52 is pushed upward together with the loading plate 52 by the elastic force of the pressing spring 53 to supply the uppermost surface of the paper P. The paper roller 61 is brought into contact with the peripheral surface. By rotating the paper feed roller 61 in this state, the uppermost position 1 in the paper feed cassette 50 is set.
Sheets of paper are fed in the direction of arrow A.

[0005]

However, in the conventional paper feed cassette, the sheet and the stacking plate are urged upward by a pressing spring, which is a compression spring. Therefore, the number of sheets to be stacked on the upper surface of the stacking plate is increased. The pressing spring expands and contracts in accordance with the pressure, and the elastic force acting on the stacking plate and the sheet from the pressing spring changes, so that the contact force of the upper surface of the sheet with the feed roller changes, and in particular, the number of sheets to be stacked on the stacking plate. When the number of sheets is small, a sufficient sheet feeding force cannot be applied to the sheet from the sheet feeding roller, and there has been a problem that sheet feeding failure occurs.

That is, as shown in FIGS. 6A and 6B, in the paper feed cassette 50, the urging force F acting on the stacking plate 52 and the sheet P from the pressing spring 53 in the upward direction is applied to the pressing spring 53. It can be expressed as a value obtained by subtracting the load W of the stacking plate 52 and the sheet P from the generated elastic force K, and the magnitude of the urging force F determines the sheet feeding force of the sheet feeding roller 61. As shown in FIG.
In a state where the number of stored sheets P at 0 is relatively large, the space between the lower surface of the stacking plate 52 and the bottom surface of the housing 51 is relatively narrow, and the pressing spring 53 is in a contracted state. On the other hand, FIG.
As shown in (B), when the number of sheets P stored in the sheet cassette 50 is relatively small, the distance between the lower surface of the stacking plate 52 and the bottom surface of the housing 51 is relatively wide, and the pressing spring 5
3 is in an extended state.

Here, the sheet P in the sheet cassette 50 is
The load W of the paper P is
However, since the weight per unit number of sheets P is relatively light and the weight of the loading plate 52 is constant, the changes in the loads W1 and W2 The change is small compared to changes in the elastic forces K1 and K2. Therefore, the sheet P in the sheet cassette 50 is
The urging forces F1 and F2 on the stacking plate 52 and the paper P when the storage amount of the paper P increases and decreases are determined mainly by the magnitude of the elastic forces K1 and K2 of the pressing spring 53, and the number of stored paper P is relatively large. The urging force F2 in a state where the number of stored sheets P is relatively small compared to the urging force F1.
Becomes smaller. For this reason, when the number of sheets of paper P stored in the paper feed cassette 50 is small, the contact force of the upper surface of the paper P against the peripheral surface of the paper feed roller 61 becomes insufficient, and the uppermost paper P in the paper feed roller 61 is removed. The rotational force becomes relatively large as compared with the separating force separating from other sheets, and the leading end of the sheet P is bent due to the double feed in which a plurality of sheets P are fed at the same time or the contact with the separation claw 54. And other problems.

An object of the present invention is to enable a substantially constant urging force to always be applied to the stacking plate and sheets regardless of the increase or decrease in the number of sheets to be stored. An object of the present invention is to provide a sheet feeding device capable of reliably preventing occurrence of a sheet feeding failure.

[0009]

The present invention has the following arrangement as means for solving the above-mentioned problems.

(1) A paper feed roller that rotatably supports a loading plate on which a plurality of sheets are stacked and placed on the upper surface with the upstream end in the paper feeding direction as a fulcrum, and opposes the upper surface of the loading plate. In the sheet feeding device that feeds a plurality of sheets in order from the one located at the uppermost position by the rotation of the sheet, the sheet is rotatably supported at an intermediate portion in the sheet feeding direction above the stacking plate, and the upstream side in the sheet feeding direction. An abutting portion that abuts on the uppermost surface of the paper placed on the stacking plate is formed, and a locking portion that locks the upper end of a tension spring whose lower end is locked to the stacking plate on the downstream side in the paper feeding direction. It is characterized in that the formed guide member is provided.

In this configuration, a guide member is rotatably supported above the stacking plate at an intermediate portion in the sheet feeding direction, and a contact portion formed on the upstream side of the guide member in the sheet feeding direction is mounted on the stacking plate. The upper end of a tension spring, which is in contact with the upper surface of the placed sheet and is formed at the downstream side of the guide member in the paper feeding direction, is locked at the lower end by a tension spring whose lower end is locked by the loading plate. The elastic force of the spring acts as an upward urging force. Therefore, when the amount of paper placed on the upper surface of the stacking plate increases or decreases, the contact portion formed on the upstream side in the sheet feeding direction of the guide member moves upward or downward, so that the guide member moves through the intermediate portion. By rotating about the fulcrum, the locking portion formed on the downstream side of the guide member in the paper feeding direction moves downward or upward. Since the direction of movement of the locking portion is the same as the direction of movement of the stacking plate, the gap between the locking portion of the guide plate and the stacking plate when the stacking amount of paper increases or decreases does not significantly change. The biasing force acting on the loading plate from the tension spring does not change significantly.

(2) The guide plate rotates about the intermediate portion as a fulcrum according to the position of the contact portion which changes according to the amount of paper loaded on the stacking plate, and locks the locking portion and the tension spring in the stacking plate. It is characterized in that the distance from the position is kept constant.

In this configuration, the distance between the locking portion of the guide member at which both ends of the tension spring is locked and the locking position of the stacking plate is determined irrespective of the amount of paper on the stacking plate. It is always kept constant. Therefore, even when the amount of paper placed on the loading plate changes, the loading plate is urged upward together with the paper by a constant urging force acting from the tension spring.

(3) The guide plate is characterized in that a locking portion is formed at a position facing both ends of the upper surface of the stacking plate in a direction perpendicular to the sheet feeding direction.

In this configuration, the locking portions for locking the tension springs for supplying the urging force to the stacking plate are formed at positions facing both ends of the guide plate in a direction orthogonal to the sheet feeding direction. Therefore, the stacking plate is urged toward the sheet feeding roller in a stable state by the tension spring on both sides in the direction perpendicular to the sheet feeding direction.

(4) The guide plate does not oppose the sheet placement range on the upper surface of the stacking plate in a predetermined range including the downstream end in the sheet feeding direction.

In this configuration, the sheet placement range on the upper surface of the stacking plate is opened upward without facing a predetermined range including the downstream end of the guide plate in the sheet feeding direction.
Accordingly, the upper portion of the loading range on the upper surface of the loading plate is not closed by the guide plate, and the paper can be easily loaded on the loading range on the upper surface of the loading plate.

[0018]

FIG. 1 is a schematic front sectional view showing the structure of a copying machine to which a sheet feeding apparatus according to an embodiment of the present invention is applied. The copying machine 1 includes a scanner unit 2, an image forming processing unit 3, a paper feeding unit 4, and a paper discharging unit 5. The scanner unit 2 includes a transparent glass platen 6 on the upper surface.
It has. The upper surface of the document table 6 is openably and closably covered with a document cover 7. Inside the scanner section 2, an exposure lamp 8, mirrors 9a to 9c, a lens 10, and a photoelectric conversion element (CCD) 11 are arranged. The exposure lamp 8 and the mirrors 9a to 9c move the lower surface of the document table 6 at a predetermined speed, and scan the image of the document placed on the upper surface of the document table 6 with the light of the exposure lamp 8. Exposure lamp 8
Are reflected by the mirrors 9a to 9a.
An image is formed on the light receiving surface of the CCD 11 via the lens c and the lens 10. The CCD 11 outputs an electric signal corresponding to the amount of received light as an image signal.

The image forming processing section 3 supports a photosensitive drum 12 having a photoconductive layer formed on the surface so as to be rotatable in the direction of arrow A. Around the photosensitive drum 12, a charger 13,
The writing unit 14, the developing device 15, the transfer device 16, and the cleaner 17 are arranged in this order along the rotation direction of the photosensitive drum 12. The charger 13 uniformly applies a charge of a single polarity to the surface of the photosensitive drum 12. The writing unit 14 receives image data obtained by subjecting an image signal output from the CCD 11 to predetermined image processing and inputs image data modulated based on the image data to the photosensitive drum 1.
Irradiate the surface of No. 2. Thereby, the photosensitive drum 12
An electrostatic latent image corresponding to the image data is formed on the surface by photoconductive action. The developing device 15 includes the photosensitive drum 12
Supplying developer to the electrostatic latent image formed on the surface of
The electrostatic latent image is visualized into a developer image.

The paper supply unit 4 is provided with a paper supply cassette 20 which stores a plurality of sheets of the same size in a stacked state. In the paper supply unit 4, a paper supply roller 21 facing the uppermost surface of the paper stored in the paper supply cassette 20 is disposed. A paper conveyance path is formed between the paper supply unit 4 and the photosensitive drum 12 of the image forming processing unit 3 and the transfer unit 16, and between the paper supply unit 4 and the paper discharge unit 5.
The paper feed unit 4 drives the paper feed roller 21 prior to the rotation of the photoconductor drum 12 and removes one of the plurality of sheets stored in the paper feed cassette 20 from the uppermost sheet. Feed paper into the paper transport path. The fed sheet is stopped with the front end thereof in contact with the registration roller 22. The registration roller 22 starts to rotate in synchronization with the rotation of the photosensitive drum 12, and the developer image having the front end portion of the paper carried on the surface of the photosensitive drum 12 between the photosensitive drum 12 and the transfer unit 16. The sheet is conveyed to the image forming processing unit 3 at a timing facing the front end of the sheet.

The transfer unit 16 transfers the developer image carried on the surface of the photosensitive drum 12 to the surface of the sheet by, for example, electrostatic force generated by corona discharge. The sheet on which the developer image has been transferred in this manner is guided to the fixing device 18 and is heated and pressed. The developer image transferred onto the sheet is melted by heating by the fixing device 18 and firmly fixed on the surface of the sheet by pressing. The sheet that has passed through the fixing device 18 is discharged to the upper surface of a discharge tray 24 by a discharge roller 23.

In the paper feeding section 4 of the copying machine 1, the paper feeding cassette 20 and the paper feeding roller 21 constitute the paper feeding device of the present invention.

FIG. 2 is an external view showing a configuration of a paper feed cassette mounted on a paper feed unit of the copying machine. The paper feed cassette 20 includes a guide plate 30,
A loading plate 32, a tension spring 33 and a separation claw 34 are provided. The guide plate 30 is pivotally supported inside the housing 31 at both ends in a direction perpendicular to the sheet feeding direction at an intermediate portion 30c in the sheet feeding direction. A contact roller 30a, which is a contact portion, is pivotally supported at an end of the guide plate 30 on the upstream side in the sheet feeding direction. At the downstream end of the guide plate 30 in the sheet feeding direction, locking portions 30b are formed near both ends in a direction perpendicular to the sheet feeding direction. The loading plate 32 is pivotally supported on the bottom surface of the housing 31 at the upstream end in the sheet feeding direction. At both ends of the stacking plate 32 parallel to the paper feeding direction, locking portions 32a are formed at intermediate portions in the paper feeding direction. Locking part 3 of guide plate 30
0b and the locking portion 32a of the loading plate 32,
Upper and lower ends are locked. The separation claw 34 is attached to the housing 3
1 is fixed to the upper end of a front end guide (35) (not shown) arranged at the downstream end in the paper feeding direction. A rear end guide (36) (not shown) is disposed at the upstream end in the sheet feeding direction inside the housing 31.

FIG. 3 is a view showing a state in which sheets are stored in the sheet cassette. The above paper cassette 20 is
A plurality of sheets P are stacked and stored on the upper surface of the stacking plate 32. At this time, the storage position of the paper P in the paper feeding direction in the housing 31 is defined by the front end guide 35 and the rear end guide 36. The vertical storage position of the paper P in the housing 31 is defined by the separation claw 34. Loading plate 3
A peripheral surface of a contact roller 30 a pivotally supported on the upstream end of the guide plate 30 in the sheet feeding direction comes into contact with the uppermost surface of the plurality of sheets P stacked and placed on the upper surface of the sheet 2. When the paper cassette 20 is mounted on the paper feed unit 4 of the copying machine 1, the vicinity of the downstream end of the uppermost surface of the paper P in the paper feed direction faces the peripheral surface of the paper feed roller 21. The stacking plate 32 on which the plurality of sheets P are placed is urged upward together with the sheets P by the elastic force of the tension spring 33. Therefore, the downstream end of the uppermost surface of the sheet P in the sheet feeding direction is in contact with the lower surface of the separation claw 34.

In this configuration, assuming that the rotation speed of the paper feed roller 21 is constant, the conveyance force of the paper P by the paper feed roller 21 is determined by the contact force F of the paper P against the peripheral surface of the paper feed roller 21. The contact force F is approximately determined by the difference between the elastic force K of the tension spring 33 and the weight P of the sheet P placed on the loading plate 32 and the weight W of the loading plate 32.

As shown in FIG. 2, since the elastic force of the tension spring 33 acts on both ends of the stacking plate 32 in the direction perpendicular to the sheet feeding direction, the stacking plate 32
In addition, it can be urged upward in a stable state.

FIG. 4 is a cross-sectional view showing a state when the number of sheets stored in the sheet cassette changes.
As shown in FIG. 4A, when the number of sheets P stored in the sheet cassette 20 is relatively small, the stacking plate 32
From the upper surface of the sheet P to the uppermost surface of the sheet P is relatively low, and the position of the contact roller 30a pivotally supported on the upstream end of the guide plate 30 in the sheet feeding direction is relatively low. Thus, the inclination angle from the horizontal direction of the guide plate 30 pivotally supported by the intermediate portion 30b above the loading plate 32 in the housing 31 increases. Therefore, the guide plate 30
The locking portion 30 formed at the downstream end in the paper feeding direction
The position of c in the housing 31 is relatively high, and the position of the downstream end in the sheet feeding direction of the stacking plate 32 connected to the locking portion 30c via the tension spring 33 is also relatively high.

On the other hand, as shown in FIG. 4B, when the number of sheets P stored in the sheet cassette 20 is relatively large, the height from the upper surface of the stacking plate 32 to the uppermost surface of the sheets P is compared. The position of the contact roller 30a in the housing 31 is relatively high, and the inclination angle of the guide plate 30 from the horizontal direction is small. Therefore, the position of the locking portion 30c in the housing 21 is relatively low, and the loading plate 32
At the downstream end in the paper feeding direction is relatively low.

As described above, the number of sheets P stored in the sheet cassette 20, that is, from the upper surface of the stacking plate 32,
Of the guide plate 30 according to the height up to the top surface of the
The vertical position of 0c changes, and accordingly, the vertical position of the downstream end of the stacking plate 32 in the paper feeding direction also changes. Thus, even when the number of sheets of paper P placed on the stacking plate 32 increases or decreases, the uppermost surface of the paper P always contacts the peripheral surface of the paper feed roller 21.

That is, the sheet P in the sheet cassette 20
When the number of stored sheets increases or decreases, the uppermost surface of the sheet P comes into contact with the peripheral surface of the sheet feeding roller 21 so that the stacking plate 32
The vertical position at which the downstream end in the paper feed direction should be located changes, but the locking portion 30c of the guide plate 30 matches the vertical position at which the downstream end in the paper feed direction should be located on the stacking plate 32. The vertical position also moves. Therefore,
Regardless of the number of sheets P stored in the sheet cassette 20, the rotation of the sheet feeding roller 21 can move the uppermost sheet P in the sheet feeding direction, and the locking portion of the guide plate 30. The distance between the end 30c and the downstream end of the stacking plate 32 in the sheet feeding direction can be made substantially constant.

Here, the conveying force of the paper P by the paper feed roller 21 is, as described above, the peripheral surface of the paper feed roller 21 obtained by subtracting the weight W of the stacking plate 32 and the paper P from the elastic force K of the tension spring 33. The elastic force K of the tension spring 33 is proportional to the length of the tension spring 33, but the guide plate is not affected by the number of sheets P stored in the paper cassette 20. Since the distance between the locking portion 30c of the sheet feeding cassette 30 and the downstream end of the stacking plate 32 in the paper feeding direction is substantially constant, the paper P
Elastic force K of the tension spring 33 even when the number of stored
Is made substantially constant.

On the other hand, the paper P in the paper feed cassette 20
Although the weight of the paper P naturally changes as the number of stored papers changes, the weight of the stacking plate 32 is constant and the weight per unit number of the paper P is relatively light. The weight W of the stacking plate 32 and the sheet P to be subtracted from the elastic force K when calculating the contact force F is determined by the feed cassette 2
There is no significant change due to a change in the number of sheets of paper P stored within zero.

Therefore, even when the number of sheets of paper P stored in the paper feed cassette 20 increases or decreases, the tension spring 33
And the weight W of the loading plate 32 and the paper P
Do not change significantly. For this reason, FIG.
As shown in (A), when the number of sheets of paper P stored in the paper cassette 20 is relatively small, the contact force Fa = Ka−Wa of the uppermost surface of the paper P against the peripheral surface of the paper feed roller 21.
4B, the contact force Fb of the uppermost surface of the sheet P with respect to the peripheral surface of the sheet feeding roller 21 in a state where the number of sheets P stored in the sheet cassette 20 is relatively large, as shown in FIG.
-Wb substantially matches. Thus, regardless of the number of sheets P stored in the sheet cassette 20, the uppermost surface of the sheet P can be brought into contact with the peripheral surface of the sheet feeding roller 21 with a substantially constant contact force F. It is possible to reliably prevent the paper P from being double-fed or a paper feed failure while maintaining the paper P in a stable state.

In the guide plate 30, the loading plate 32
By removing a predetermined range including a downstream end in the paper feeding direction from a portion of the upper surface facing the mounting range of the paper P,
The work of placing the paper P on the loading plate 32 can be facilitated.

In the above-described embodiment, the case where the paper feeding apparatus of the present invention is applied to a copying machine has been described. However, a plurality of stacked and stored sheets are fed one by one to perform predetermined processing. The paper feeder of the present invention can be similarly applied to a general paper processing apparatus that performs the following.

[0036]

The present invention has the following effects.

(1) A guide member is rotatably supported above the loading plate at an intermediate portion in the paper feeding direction, and a contact portion formed on the upstream side of the guide member in the paper feeding direction is placed on the loading plate. The upper end of a tension spring whose lower end is locked to a loading plate is locked to a locking portion formed on the downstream side of the guide member in the paper feeding direction, and the elastic force of the tension spring is fixed to the loading plate. Acts as an upward biasing force, so that when the amount of paper placed on the upper surface of the stacking plate increases or decreases, the engaging portion moves downward or upward with the upward or downward movement of the contact portion. Can be moved upward. As a result, even when the amount of paper loaded increases or decreases, the gap between the locking portion of the guide plate and the loading plate does not greatly change, and the biasing force acting on the loading plate from the tension spring is made substantially constant. As a result, a stable paper feed state by the paper feed roller can be maintained.

(2) The distance between the locking portion of the guide member at which both ends of the extension spring is locked and the locking position of the loading plate is always constant regardless of the amount of paper loaded on the loading plate. In this way, even when the amount of paper placed on the stacking plate increases or decreases, the stacking plate is urged upward together with the sheet by a constant urging force acting from the tension spring, and the paper feed roller stabilizes the stacking plate. The maintained paper feeding state can be maintained.

(3) By forming a locking portion for locking a tension spring for supplying a biasing force to the stacking plate at a position facing both ends of the guide plate in a direction perpendicular to the sheet feeding direction,
The loading plate can be urged toward the paper feed roller in a stable state by a tension spring on both sides in a direction perpendicular to the paper feed direction.

(4) The guide plate is loaded by opening the paper loading range on the upper surface of the loading plate upward so as not to face a predetermined range including the downstream end of the guide plate in the paper feeding direction. The paper can be easily placed in the placement range on the upper surface of the stacking plate so that the upper part of the loading range on the upper surface of the plate is not closed.

[Brief description of the drawings]

FIG. 1 is a schematic front sectional view showing a configuration of a copying machine to which a sheet feeding device according to an embodiment of the present invention is applied.

FIG. 2 is an external view showing a configuration of a paper feed cassette mounted on a paper feed unit of the copying machine.

FIG. 3 is a cross-sectional view illustrating a state in which sheets are stored in the sheet cassette.

FIG. 4 is a cross-sectional view showing a state when the number of sheets stored in the paper feed cassette has increased or decreased.

FIG. 5 is a cross-sectional view illustrating a state in which sheets are stored in a conventional sheet cassette.

FIG. 6 is a cross-sectional view showing a state in which the number of stored sheets in a conventional paper feed cassette increases or decreases.

[Explanation of symbols]

 1-Copier 3-Image Forming Processing Unit (Processing Unit) 4-Paper Feeding Unit 5-Discharge Unit 20-Paper Cassette 21-Paper Feed Roller 30-Guide Plate 30a-Contact Roller (Contact Unit) 30b- Intermediate portion 30c-locking portion 31-housing 32-loading plate 32a-locking portion 33-tensile spring

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Takashi Goto 22-22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka F-term (reference) 3F343 FA02 FB02 FB04 FC01 GA03 GB01 GC01 GD01 HA27 HD09 HD10 HD18 JA01 KB04 LA04 LA15 LC06 LC07 LC20 LD04 MB04 MB12 MC11 MC12

Claims (4)

[Claims] An upper end in a sheet feeding direction rotatably supporting a stacking plate on which a plurality of sheets are stacked and mounted on an upper surface; In a sheet feeding device that feeds a plurality of sheets in order from the one positioned at the top by rotation, the sheet is rotatably supported at an intermediate portion in the sheet feeding direction above a stacking plate, and is disposed upstream in the sheet feeding direction. Forming a contact portion that contacts the top surface of the paper placed on the stacking plate, and forming a locking portion on the downstream side in the paper feeding direction that locks the upper end of a tension spring whose lower end is locked to the stacking plate. A sheet feeding device provided with a guide member. 2. The guide plate according to claim 1, wherein said guide plate rotates around an intermediate portion as a fulcrum according to a position of the contact portion which changes according to the amount of paper loaded on said stacking plate. The paper feeding device according to claim 1, wherein a distance between the sheet feeding device and the sheet feeding device is maintained constant. 3. The feeding device according to claim 1, wherein the guide plate has a locking portion formed at a position facing both ends of the upper surface of the stacking plate in a direction perpendicular to the sheet feeding direction. Paper equipment. 4. The sheet feeding apparatus according to claim 1, wherein the guide plate does not face a sheet placement area on the upper surface of the stacking plate in a predetermined range including a downstream end in the sheet feeding direction. A paper feeder according to claim 1.