JP2002211770A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeder capable of preventing a paper misalignment during paper feeding cassette insertion without unnecessarily enhancing rigidity of a paper feeding cassette casing and manually recomposing a tilting preventing member to every paper size. SOLUTION: When size of printing paper housed in the paper feeder 9 is changed and side regulating plates 22A and 22B are arranged in positions corresponding to the desired paper size, the tilting preventing member 40 moves in association with the movements of the side regulating plates to a position corresponding to the desired paper size. When a paper feeding cassette 20 is attached to the paper feeder 9, the tilting preventing member 40 protrudes from a cutout part 51 provided in a side wall 20A of the paper feeding cassette 20 and it abuts on an abutting part 50 provided on the casing 9A of the paper feeder 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a sheet feeding device used for an image forming apparatus such as a printer or a copying machine. More specifically, the present invention relates to a sheet feeding device including a regulating member for regulating both end positions of a sheet bundle. In particular, the present invention is suitable for a paper feed device of a claw saw type.

[0002]

2. Description of the Related Art In a sheet feeding apparatus in which a sheet feeding direction is orthogonal to a sheet feeding direction, a side regulating plate is provided for regulating both end positions of a sheet bundle in the sheet feeding direction. The side regulating plate regulates the position of the sheet bundle to prevent the sheet from shifting. However, when inserting the paper cassette into the paper feeder,
Due to the inertial force of the sheet bundle contained in the paper cassette, the side regulating plate moves, or in the worst case, the side regulating plate falls, resulting in misalignment of the paper stored in the paper cassette. There was a case.

[0005] When a sheet position shift occurs, an image position shift (reference position shift in the main scanning direction) occurs, and in the worst case, an image defect occurs. Further, in the paper feeding device of the claw saw type, since the claw attached to the side regulating plate also moves at the same time, the amount of hook of the claw on the paper changes (FIG. 12). In some cases, sheets of paper came off the nail (FIG. 13).
In such a state, sufficient paper reversing performance cannot be obtained, and skew occurs due to double feeding or an imbalance in the resistance balance of the claws, and jams due to the skew frequently occur.

[0004] Conventionally, measures have been taken into the sheet feeding device to prevent the side regulating plate from moving or falling when the sheet feeding cassette is inserted. As one of the paper feeding devices in which the preventive measures are incorporated, for example, a device in which the rigidity of the side regulating plate and the holding member thereof is increased can be cited. In this paper feeding device, the rigidity of the side regulating plate and the holding member is increased to prevent the side regulating plate from moving or falling due to the inertia of the paper generated when the paper feeding cassette is inserted. As another sheet feeding device, for example,
No. 34022 is disclosed. In this paper feeder, a side-prevention member for preventing the side control plate from moving or falling is manually arranged between the side-restriction plate and the paper-feed cassette housing, so that a side-reduction member generated when the paper-feed cassette is inserted is provided. The restriction plate is prevented from moving or falling.

[0005]

However, in the former conventional sheet feeding device, the side regulating plate and the holding member are expensive in order to increase the rigidity of the side regulating plate and the holding member. There was a problem that would. On the other hand, in the latter case, it is not necessary to increase the rigidity of the side regulating plate, but it is necessary to increase the rigidity of the sheet cassette housing. Further, it is necessary for the user to manually reassemble the fall prevention member for each sheet size. For this reason, there is a problem that the rearrangement operation is troublesome, and it is not possible to avoid the occurrence of skew due to an erroneous operation by the user and the occurrence of a jam due to the skew.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and does not increase the rigidity of the sheet cassette housing more than necessary, and manually operates the falling prevention member for each sheet size. It is an object of the present invention to provide a sheet feeding device capable of preventing a sheet from being displaced when a sheet feeding cassette is inserted without re-arrangement.

[0007]

SUMMARY OF THE INVENTION A paper feeder according to the present invention, which has been made to solve the above-mentioned problems, has a paper feed cassette for accommodating and pulling out a paper bundle, and both end positions of the paper bundle in the pull-out direction. Has a pair of regulating members that can move in the pulling-out direction while restricting the movement of the regulating members caused by the inertial force of the sheet bundle when the sheet cassette is inserted. When the regulating member is moved to a position corresponding to a predetermined paper size, the regulating member moves to a position corresponding to the predetermined paper size in conjunction with the movement of the regulating member.

In this paper feeder, the positions of both ends of the sheet bundle stored in the paper feed cassette are regulated by the pair of regulating members. This prevents the sheet from being displaced in the sheet cassette. Further, the falling prevention member prevents the regulating member from moving or falling caused by the inertia of the sheet bundle when the sheet cassette is inserted. For this reason, even when the sheet cassette is inserted, the positional deviation of the sheet in the sheet cassette is reliably prevented. Then, when the falling prevention member moves the regulating member to a position corresponding to the predetermined paper size,
It moves to a position corresponding to a predetermined paper size in conjunction with the movement of the regulating member. Therefore, there is no need for the user to perform the operation of changing the fall prevention member for each sheet size. Therefore, erroneous operation by the user does not occur, so that skew due to erroneous operation by the user, and furthermore, occurrence of jam due to the skew can be reliably avoided.

In the paper feeder according to the present invention, the fall prevention member may be provided between the regulating member disposed on the back side in the pull-out direction and the housing on the back side of the paper feeder. Then, the falling prevention member is moved relative to the regulating member in a direction intersecting with the movement direction of the regulating member, or is formed on an arc centered on a fulcrum provided on the regulating member within the plane of the regulating member. It is preferable to move along.

Further, in the paper feeder according to the present invention,
It is desirable that a notch is provided on the side wall of the sheet cassette facing the falling prevention member so as to correspond to the moving range of the falling prevention member. Then, it is preferable to provide a support portion to which the fall prevention member comes in contact when the paper feed cassette is inserted into the housing on the back side of the paper feed device. Here, it is preferable that a plurality of contact portions corresponding to a plurality of types of paper sizes are formed on at least one of the support portion and the fall prevention member.

With this configuration, when the sheet cassette is mounted, the fall prevention member projects from the notch provided in the sheet cassette. For this reason, the fall prevention member does not abut on the paper cassette housing, but comes into contact with the support portion provided on the paper feeding device housing. In other words, the fall prevention member prevents movement and fall of the regulating member by abutting on the support provided on the sheet feeding device housing. The support portion with which the fall prevention member abuts is provided on the housing of the sheet feeding device having inherently high rigidity. Therefore, the movement of the regulating member and the falling of the regulating member are reliably prevented by the falling prevention member without increasing the rigidity of the sheet cassette housing. Further, a plurality of abutting portions corresponding to a plurality of types of paper sizes are formed on the support portion or the fall prevention member. Therefore, in the paper feeding device according to the present invention, the positional deviation of the paper is reliably prevented regardless of the paper size set in the paper feed cassette.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a sheet feeding device according to a first embodiment of the present invention; This embodiment is a printer equipped with the paper feeding device of the present invention.

First, FIG. 1 shows a schematic configuration of a printer according to the present embodiment. The printer 100 includes a photosensitive drum 1, a laser scanning optical system 3, a full-color developing device 4, an endless intermediate transfer belt 5, a fixing device 8, a paper feeding device 9, and the like. Also, at the top of the printer 100,
Output tray 1 for storing printed out print paper
3 are provided. And around the photosensitive drum 1,
Charging charger 2, developing device 4, primary transfer roller 51,
And a cleaning device 6.

The laser scanning optical system 3 moves clockwise (arrow A).
The electrostatic latent image is formed on the photosensitive drum 1 rotating in the direction
Includes well-known components such as -θ lenses. The control unit receives image data for each color of yellow (Y), magenta (M), cyan (C), and black (K) from a host device connected to the printer 100.
Then, the laser scanning optical system 3 irradiates the photosensitive drum 1 with a laser beam corresponding to image data for each color from between the charger 2 and the developing device 4.

The developing device 4 develops an electrostatic latent image on the photosensitive drum 1 to form a toner image. And
Four color developing units 4Y, 4M, 4C, and 4K containing developers containing toners of yellow (Y), magenta (M), cyan (C), and black (K) are attached to the developing rack 400. . The developing rack 400 is rotatable counterclockwise about the support shaft 4a. Each time an electrostatic latent image corresponding to each color is formed on the photosensitive drum 1, the developing device 4 rotates the developing rack 400 so that the corresponding color developing device is located at the developing position, and An electrostatic latent image of each color on the body drum 1 is developed by a developing device corresponding to the color.

The intermediate transfer belt 5 is wound around a roller group including a rotatable primary transfer roller 51 and a support roller 52. The intermediate transfer belt 5 is driven counterclockwise (in the direction of arrow B). The primary transfer roller 51 is provided at a position facing the photosensitive drum 1 with the intermediate transfer belt 5 interposed therebetween. By applying a primary transfer voltage to the primary transfer roller 51,
The toner image on the photosensitive drum 1 is primarily transferred to the intermediate transfer belt 5. Further, the intermediate transfer belt 5
Is supported by the support roller 52, and the secondary transfer roller 7 is disposed while being pressed against the support roller 52. And
By applying a secondary transfer voltage to the secondary transfer roller 7, the toner image on the intermediate transfer belt 5 is transferred onto printing paper.

The paper feeding device 9 is provided with a paper feeding cassette 20 for stacking and storing printing paper on which a toner image is transferred. In addition, a semicircular paper feed roller 10 is provided to feed out the print paper stored in the paper feed cassette 20 one by one. Further, a timing roller 11 for supplying printing paper to the secondary transfer position in synchronization with the toner image on the intermediate transfer belt 5 is disposed in the paper transport path. Further, a fixing device 8 is provided at a position downstream of the timing roller 11, and a sheet discharge roller 12 is provided at a position further downstream.

Here, the sheet feeding device 9 which is a feature of the present invention is described.
Will be described in detail with reference to FIG. The paper feeding device 9 includes the paper feeding cassette 20 that can be pulled out as described above. Then, in order to accommodate the printing paper bundle in the paper feeding cassette 20, a loading plate 21 (see FIG. 1) for loading the printing paper, and a pair of side regulating plates 22A for regulating both end positions in the width direction of the printing paper bundle. , 22B (see FIG. 2) and a rear end regulating plate 2 for regulating the rear end position of the printing paper bundle.
3 (see FIG. 1). Here, the loading plate 21
Is attached to the sheet cassette 20 so as to be rotatable up and down around a support shaft 24, and is urged upward by a spring 25 (see FIG. 1).

The side regulating plates 22A and 22B are L
It is a thin plate having a U-shaped cross section, and includes side portions 26A and 26B for regulating a print sheet bundle, and bottom portions 27A and 27B located on the bottom surface of the sheet feeding cassette 20. The side surfaces 26A and 26B are substantially rectangular, and the bottom surfaces 27A and 27B are substantially T-shaped. The racks 30A and 30B are formed on the bottom portions 27A and 27B. Nonwoven fabrics 32, 32 are attached to the lower surfaces of the bottom portions 27A, 27B (see FIG. 4), and the side regulating plates 22A, 22B are moved by a frictional force that does not hinder the movement of the side regulating plates 22A, 22B. 22A, 22B
Holding the position.

Such side regulating plates 22A, 22B
Are arranged such that the respective side surfaces 26A and 26B face each other, and the respective bottom surfaces 27A and 26B.
The racks 30A and 30B formed in 27B are also arranged so as to face each other. A pinion gear 31 is attached to the bottom surface of the sheet cassette 20 so as to mesh with the respective racks 30A and 30B. The racks 30A and 30B and the pinion gear 31 form a mechanism for moving the side regulating plates 22A and 22B.

With such a configuration, when one side regulating plate 22A (22B) is moved, the other side regulating plate 22B (22A) is also moved. At this time, when the one side regulating plate 22A (22B) is moved in a direction approaching the sheet bundle, the other side regulating plate 22B is moved.
(22A) also moves in the direction approaching the sheet bundle. When the one side regulating plate 22A (22B) is moved in a direction away from the sheet bundle, the other side regulating plate 22B (22B) is moved.
A) also moves away from the sheet bundle. At this time, the amount of movement of each side regulation plate 22A, 22B is the same. That is, the pinion gear 31 causes the side regulating plate 22
The movement amount and movement direction of A and 22B are regulated. Thus, in the paper feed cassette 20, even if the size of the printing paper to be stored changes, the side regulating plate 22
A and 22B regulate the positions of both ends of the printing paper at the center of the paper transport path when the paper cassette 20 is mounted.

The side surface 26A of the side regulating plate 22A
As shown in FIG. 3, a fall prevention member 40 is attached to prevent the side regulating plate 22A from moving or falling when the sheet cassette 20 is mounted. This fall prevention member 40 is a rectangular parallelepiped,
It is held by an L-shaped holding member 41. The fall prevention member 40 is movably attached to the side regulating plate 22A via the holding member 41.

The holding member 41 has a side surface portion 42 for holding the fall prevention member 40 and a bottom surface portion 4 located on the bottom surface of the sheet cassette 20 and attached to the side regulating plate 22A.
And 3. Note that the bottom surface 43 of the holding member 41 is located below the bottom surface 27A of the side regulating plate 22A. The side surface 42 of the holding member 41 is in contact with the side surface 26A of the side regulating plate 22A.
The bottom surface portion 43 of one is in contact with the bottom surface portion 27A of the side regulating plate 22A.

The rack 4 is attached to the tip of the bottom 43.
4 are formed. The bottom surface 43 is provided with a linear guide hole 45 for moving the fall prevention member 40 held by the holding member 41 in parallel with the side regulating plate 22A. In this guide hole 45, two pins 46, 46 for attaching the holding member 41 to the side regulating plate 22A are located. The two pins 46 are arranged on a straight line with a certain interval. For this reason, the holding member 41 is provided with the side regulating plate 22A.
On the other hand, it is possible to move only in the direction in which the guide hole 45 is provided (the direction orthogonal to the moving direction of the side regulating plates 22A and 22B).

Further, a pinion gear 47 is attached to the bottom surface of the sheet cassette 20 so as to mesh with the rack 44 and the rack 30B. For this reason, the side regulating plate 22
When B moves, the pinion gear 47 rotates, and the rotation of the pinion gear 47 causes the holding member 41 to move. That is, the fall prevention member 40 moves in conjunction with the movement of the side regulating member 22B. Of course, the fall prevention member 40 is also linked to the movement of the side regulating plate 22A. This is because the side regulating plate 22A moves in conjunction with the side regulating plate 22B. At this time, the fall prevention member 40
Moves in the direction perpendicular to the direction of movement of the side regulating plate 22B (22A).

As described above, since the fall prevention member 40 moves in conjunction with the movement of the side regulating plates 22A and 22B, it is not necessary to rearrange the fall prevention member 40 every time the user changes the paper size. Therefore, an erroneous operation of the fall prevention member 40 by the user does not occur. Therefore, the occurrence of a skew due to an erroneous operation by the user and the occurrence of a jam due to the skew can be reliably avoided.

The side surface 26 of the side regulating plate 22A
The housing 9 </ b> A of the sheet feeding device 9 facing A is provided with a support portion 50 to which the fall prevention member 40 contacts when the sheet feeding cassette 20 is mounted. The support portion 50 is provided corresponding to a range in which the fall prevention member 40 can move. A notch 51 is provided on the side wall 20A of the sheet feeding cassette 20 facing the side surface 26A of the side regulating plate 22A so as to correspond to the range in which the fall prevention member 40 moves. Thus, when the sheet cassette 20 is mounted, the fall prevention member 40 comes into contact with the support portion 50 and the side regulating plate 22A.
The amount of falling is regulated. As described above, the fall prevention member 40 is brought into contact with the supporting portion 50 provided on the housing 9A of the paper feeding device 9 instead of the side wall 20A of the paper feeding cassette 20, so that the side wall (housing) 20 of the paper feeding cassette 20 is formed.
It is possible to reliably prevent the side regulation plate 22A from falling down without increasing the rigidity of A.

In the present embodiment, the support portion 50 has a B5 size contact surface so as to correspond to three types of paper sizes, B5 size, A4 size, and LT size, which can be accommodated in the sheet cassette 20. 50A, A4 size contact surface 50B, and LT size contact surface 50C are formed. Then, when the side regulating plate 22A (22B) is moved to each paper size position, the pinion gear 31 is moved such that the fall prevention member 40 is moved by a distance necessary to make it contact the contact surface of each paper size. And the gear ratio of the racks 30A, 30B and 44 are set.

Returning to FIG. 2, the paper feed cassette 20 is provided with separation claws 28A and 28B for regulating the height position of the leading end of the printing paper bundle and separating the paper. The separation claws 28A, 28B are connected to the side regulating plates 22A, 22B.
, Respectively, and the side regulating plates 22A,
It moves integrally with 22B. The loading plate 21 and the spring 25 (see FIG. 1) always cause both ends of the leading end of the printing paper positioned at the top of the printing paper bundle accommodated in the paper feeding cassette 20 to be separated from each other by separation claws 28A and 28B.
To come into contact with.

Next, a printing operation for forming an image in the printer 100 having the above configuration will be briefly described. First, image data for each color component of yellow (Y), magenta (M), cyan (C), and black (K) is input to the printer 100 from the host device.
Then, the photosensitive drum 1 is rotated and their peripheral devices are driven. Then, an exposure control signal is output based on the image data of yellow (Y), and the electrostatic latent image of yellow (Y) is written on the photosensitive drum 1 by the laser scanning optical system 3. A toner image is formed on the latent image by the developing device 4Y, and the toner image is primarily transferred onto the intermediate transfer belt 5 by the primary transfer roller 51. Thereafter, similar processing is performed for the components of magenta (M), cyan (C), and black (K). As a result, the four color toner images are transferred onto the intermediate transfer belt 5 in a superimposed manner.

Next, in synchronism with the rotation of the intermediate transfer belt 5 on which the four color toner images are transferred in an overlapping manner, the sheet feeding device 9
, One print sheet is taken out by the sheet feed roller 10 and is conveyed toward the secondary transfer position. The fed printing paper is fed to the intermediate transfer belt 5 by the timing roller 11.
After being synchronized with the upper toner image, the toner image is sent to the secondary transfer roller 7. Then, the toner image on the intermediate transfer belt 5 is secondarily transferred onto the printing paper by the secondary transfer roller 7. Next, the printing paper to which the toner image has been transferred is thermally fixed by the fixing device 8, and then discharged to the discharge tray 13 by the discharge roller 12. This completes image formation for one sheet. Thereafter, the same operation is repeated, and the printing paper is continuously fed one by one from the paper feeding device 9, thereby forming an image of a plurality of sheets.

Here, the operation when changing the size of the printing paper stored in the paper feeding cassette 20 will be described. First, the sheet cassette 20 is pulled out of the sheet feeding device 9. Then, the remaining printing paper stored in the paper cassette 20 is taken out. Next, the side regulating plate 22A is moved to a position corresponding to a desired paper size. At this time, the pinion gear 3 is moved by the movement of the side regulating plate 22A.
1 rotates. Then, the rotation of the pinion gear 31 also moves the side regulating plate 22B. At this time, when changing to a paper size larger than the previous paper size, the side regulating plates 22A and 22B move away from each other. On the other hand, when changing to a paper size smaller than the previous paper size, the side regulating plates 22A and 22A
B move closer to each other.

When the side regulating plate 22B moves as described above, the pinion gear 47 rotates. Then, the holding member 41 moves by the rotation of the pinion gear 47. For this reason, the fall prevention member 40 also moves. At this time, since the moving direction of the holding member 41 is regulated by the guide hole 45, the fall prevention member 40 moves in the direction regulated by the guide hole 45, that is, the direction orthogonal to the moving direction of the side regulating plates 22A and 22B.

Next, when the side regulating plates 22A and 22B have been installed at the positions corresponding to the desired paper size, the rear end regulating plate 23 is installed at the position corresponding to the desired paper size. Then, when the installation of the side regulating plates 22A, 22B and the rear end regulating plate 23 is completed, the printing paper of a desired size is stored in the paper feed cassette 20. Thus, the printing paper bundle is stored in the paper feeding cassette 20. At this time, both ends of the printing paper bundle are regulated by the side regulating plates 22A and 22B, the rear end is regulated by the rear end regulating plate 23, and the front end is regulated by the separation claws 28A and 28B. For this reason, the printing paper is stored in the paper feed cassette 20 in a state where there is no positional deviation of the printing paper.

When the storage of the printing paper in the paper cassette 20 is completed, the paper cassette 20 is moved to the paper feeding device 9.
And insert it. Here, for example, if the paper size is LT
If the size is set to the size, as shown in FIG.
Contact 0C. If the paper size is set to B5 size, the fall prevention member 40 comes into contact with the B5 size contact surface 50A of the support portion 50. Also, if the paper size is set to A4 size, the fall prevention member 40 is
It comes in contact with the 4 size contact surface 50B.

For this reason, even if the inertia of the printing paper bundle is applied to the side regulating plate 22A when the paper cassette 20 is mounted,
The side regulating plate 22A is supported by the supporting portion 50 (the housing 9A of the sheet feeding device 9) via the fall prevention member 40. Therefore,
When the sheet cassette 20 is mounted, the side regulating plate 22A is reliably prevented from moving or falling down. As a result, the printing paper accommodated in the paper cassette 20 does not shift. Therefore, the paper feeding device 9 can supply the printing paper without causing a problem such as skew.

Next, a modification will be described. In the following description, the same components as those in the above-described embodiment will be denoted by the same reference numerals, and description of the configuration, operation, and the like will be omitted.

First, a first modification will be described. In the first modification, as shown in FIG.
Paper feeder housing 9 against which the fall prevention member 40 comes in contact with the
A contact surface corresponding to each paper size is not formed on the support portion 50 provided on the
The contact surface with respect to 0 is flat. For this reason,
As shown in FIG. 6, the side regulating plate 22A (the side surface portion 26)
In (A), a tapered projection 60 is formed. Further, a taper of a shape opposite to the taper of the tapered protrusion 60 is formed on a surface of the fall prevention member 40 facing the tapered protrusion 60. The fall prevention member 40 is held by the holding member 41 so as to be in contact with the tapered projection 60. Thus, the fall prevention member 40 moves while always in contact with the tapered projection 60.

Here, the taper of the convex portion 60 is in the direction in which the side regulating plate 22A approaches the printing paper bundle (the H direction in FIG. 5).
5, the shape is such that the falling prevention member 40 expands in the moving direction (V direction in FIG. 5). For this reason, the contact surface of the fall prevention member 40, more precisely, the contact surface of the holding member 41 always moves at a fixed distance from the side wall 20 </ b> A of the sheet cassette 20. That is, with the position of the sheet cassette 20 fixed, the side regulating plate 22A
When (22B) is moved, the fall prevention member 40 moves in parallel to the housing 9A of the sheet feeding device 9 to which the side regulating plate 22A faces.

The tapered projection 6 having such a shape is used.
0 is provided, and the fall prevention member 40 is moved along the tapered surface. In this modified example, the support portion 50 against which the fall prevention member 40 comes into contact when the sheet cassette 20 is mounted is provided.
In addition, there is no need to provide a separate contact surface for each paper size. For this reason, the contact surface of the support part 50 can be made flat. Thus, no matter where the fall prevention member 40 is located, the fall prevention member 40 comes into contact with the contact surface of the support portion 50 when the paper feed cassette 20 is inserted. Therefore,
Even when printing paper of a non-standard size is set in the paper feed cassette 20, when the paper feed cassette 20 is inserted, the fall prevention member 40 comes into contact with the support portion 50, so that the side regulating plate 22A moves or falls. Is reliably prevented.

Also, instead of using two pinion gears for interlocking the movement of the side regulating plate 22A and the fall-preventing member 40, a two-stage pinion gear 61 (FIG. 7) is also different. The upper gear 62 meshes with the rack 30A and the rack 30B, and the lower gear 63
Is engaged with the rack 44 so that the side regulating plate 2
The movement of 2A, 22B and the fall prevention member 40 is linked.

Here, by changing the diameter of the pinion gear 62 and the diameter of the pinion gear 63, the side regulating plate 2
The amount of movement of 2A and 22B and the amount of movement of fall prevention member 40 can be adjusted. For example, by making the diameter of the pinion gear 63 larger than the diameter of the pinion gear 62,
The amount of movement of the fall prevention member 40 can be made larger than the amount of movement of the side regulating plates 22A and 22B. For this reason,
By adjusting the diameter of the pinion gear 62 and the diameter (gear ratio) of the pinion gear 63, the side restriction plates 22A, 22
The moving amount of the fall prevention member 40 with respect to the moving amount of B can be determined. However, when changing the movement amount, it is necessary to change the set value of the taper of the tapered convex portion 60. It is not always necessary to use the two-stage gear 61,
By adjusting (enlarging) the taper angle of the convex portion 60, it is also possible to use a single-stage gear.

Next, a second modification will be described. In the second modified example, as shown in FIG.
Does not move linearly, but moves on an arc 71 drawn about the support shaft 70. Therefore, as shown in FIG. 9, the side regulating plate 22A (the side surface 26A).
, A lever 72 (corresponding to a holding member) for holding the fall prevention member 40 is installed so as to be rotatable around the support shaft 70. The lever 72 has a spring mounting portion 75.
And a wire mounting portion 76 are provided. A spring 73 whose one end is fixed to the side regulating plate 22A is attached to the spring attaching portion 75. For this reason, the lever 72 is always pulled in the paper rear end direction (counterclockwise). A wire 74 having one end fixed to the side regulating plate 22B is attached to the wire attaching portion 76. Note that the lever 72 and the side regulating plate 22B may be connected via a pulley without being directly connected by the wire 74.

Here, since the length of the wire 74 is constant, the position of the lever 72 is determined when the tension of the wire 74 and the force of the spring 73 are balanced. Specifically, when the side regulating plate 22B is moved in a direction to approach the printing paper bundle, the distance from the lever 72 is shortened, so that the wire 74 is loosened. Then, the lever 72 rotates counterclockwise by the urging force of the spring 73. Therefore, the wire mounting portion 76 of the lever 72 moves to a position higher than the previous position. Then, when the wire 73 is no longer loose and the force of the spring 73 and the tension of the wire 74 are balanced, the rotation of the lever 72 stops.

Conversely, when the side regulating plate 22B is moved away from the printing paper bundle, the distance from the lever 72 becomes longer. However, since the length of the wire 74 is constant, the wire attachment portion 76 of the lever 72 moves to a position lower than the previous position. That is, the lever 72 rotates clockwise against the urging force of the spring 73. When the force of the spring 73 and the tension of the wire 74 are balanced, the lever 72
Stops rotating.

As described above, by moving the side regulating plate 22B, the lever 72 (the fall prevention member 40) rotates about the support shaft 70 in conjunction with the movement. A notch 51 is provided in the side wall 20A of the sheet cassette 20 corresponding to the rotation range of the fall prevention member 40 (see FIG. 10). Further, as shown in FIG.
The housing 9 </ b> A of the paper feeding device 9 is provided with a support portion 50 with which the fall prevention member 40 contacts. Thus, when the sheet cassette 20 is mounted, the fall prevention member 40 comes into contact with the support portion 50, and the amount of fall of the side regulating plate 22A is regulated. The support portion 50 includes a B5 size contact member 150A corresponding to the B5 size, an A4 size contact member 150B corresponding to the A4 size, and an LT size contact member 150C corresponding to the LT size.
The contact members of these sizes are installed on an arc on which the fall prevention member 40 moves.

As described above in detail, according to the printer 100 according to the embodiment including the modified examples, when the size of the printing paper accommodated in the paper feeding device 9 is changed, the side regulating plates 22A and 22B Is set at a position corresponding to the desired paper size, the fall prevention member 4
0 moves to a position corresponding to the desired paper size. When the paper cassette 20 is mounted on the paper feeding device 9,
The fall prevention member 40 protrudes from a cutout portion 51 provided on the side wall 20 </ b> A of the paper feed cassette 20 and abuts on a support portion 50 provided on the housing 9 </ b> A of the paper feed device 9. For this reason,
The falling prevention member 40 prevents the side regulating plate 22A from moving or falling. Thereby, the displacement of the printing paper in the paper feed cassette 20 is reliably prevented.

Further, the rigidity of the side wall 20A of the paper feed cassette 20 needs to be increased in order for the fall prevention member 40 to abut on the support portion 50 provided on the housing 9A of the paper feeder 9 having inherently high rigidity. There is no. Furthermore, there is no need for the user to perform an operation of rearranging the fall prevention member 40 for each paper size. Therefore, there is no erroneous operation by the user.
The occurrence of a skew due to an erroneous operation by the user and the occurrence of a jam due to the skew can be reliably avoided.

The above-described embodiment is merely an example, and does not limit the present invention in any way. Needless to say, various improvements and modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the support portion 50 is provided with the contact surface corresponding to a plurality of paper sizes. However, the support portion 50 is flattened as in the first modification, and the plurality of the fall prevention members 40 are provided. The contact portion corresponding to the sheet size may be formed. Also,
In the first modified example, similarly, the tapered projection 6
0 is provided on the support portion 50 without being provided on the side regulating plate 22A,
You may make it move the fall prevention member 40 along the surface of the side surface part 26A in the side regulating plate 22A.

Further, in the above-described embodiment, the case where the present invention is applied to a printer has been described. However, the present invention can also be applied to an image forming apparatus other than a printer, such as a copying machine or a facsimile. Needless to say, the paper sizes exemplified in the above-described embodiment are merely examples.

[0051]

As described above, according to the present invention, the paper feeding can be performed without increasing the rigidity of the paper feeding cassette housing more than necessary and without manually changing the fall prevention member for each paper size. There is provided a sheet feeding device capable of preventing a sheet shift when a cassette is inserted.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a printer according to an embodiment.

FIG. 2 is a perspective view illustrating a schematic configuration of the sheet feeding device of FIG. 1;

FIG. 3 is an enlarged view of a part of FIG. 2;

FIG. 4 is a top view illustrating a state in which the sheet cassette is mounted in the sheet feeding device.

FIG. 5 is a top view showing a first modification.

FIG. 6 is a perspective view showing a first modification.

FIG. 7 is a perspective view showing a modification of the pinion gear.

FIG. 8 is a side view showing a second modification.

FIG. 9 is a perspective view showing a second modification.

FIG. 10 is a top view showing a second modification.

FIG. 11 is a perspective view showing a contact portion in a second modified example.

FIG. 12 is a diagram for describing a problem in a conventional sheet feeding device.

FIG. 13 is a view for explaining a problem in the conventional sheet feeding device.

[Explanation of symbols]

 Reference Signs List 9 paper feeding device 9A housing (paper feeding device) 20 paper feeding cassette 20A side wall (paper feeding cassette) 22A, 22B side regulating plate 30A, 30B, 44 rack 31, 47 pinion gear 40 fall prevention member 41 holding member 50 support portion 51 Notch

Continued on the front page F term (reference) 3F343 FA02 FB02 FB04 FC30 GA01 GB01 GC01 GD02 HE04 HE16 HE23 HE24 JA01 KB03 LA04 LA12 LA13 LD22

Claims (7)

[Claims] 1. A sheet cassette that can receive and pull out a sheet bundle, a pair of regulating members that regulate both end positions of the sheet bundle in the pull-out direction and move in the pull-out direction, A fall prevention member for preventing movement and fall of the regulation member caused by the inertial force of the sheet bundle. The fall prevention member controls the regulation when the regulation member is moved to a position corresponding to a predetermined paper size. A sheet feeding device that moves to a position corresponding to a predetermined sheet size in conjunction with the movement of a member. 2. The sheet feeding device according to claim 1, wherein the fall prevention member is installed between a regulating member that is disposed on the back side in the pull-out direction and a housing on the back side of the sheet feeding device. A sheet feeding device characterized by being performed. 3. The paper feeding device according to claim 2, wherein the falling prevention member moves relative to the restriction member in a direction intersecting a movement direction of the restriction member. 4. The paper feeding device according to claim 2, wherein the falling prevention member moves along an arc around a fulcrum provided on the restriction member along a plane of the restriction member. Characteristic paper feeder. 5. The sheet feeding device according to claim 3, wherein a notch is formed in a side wall of the sheet cassette facing the tipping prevention member so as to correspond to a moving range of the tipping prevention member. Is provided. 6. The paper feeding device according to claim 5, wherein a support portion with which the fall prevention member abuts when the paper feeding cassette is inserted is provided in a housing on the back side of the paper feeding device. A sheet feeding device characterized by the above-mentioned. 7. The paper feeding device according to claim 6, wherein at least one of the support portion and the fall prevention member has a plurality of contact portions corresponding to a plurality of types of paper sizes. A sheet feeding device characterized by the above-mentioned.