JP2002370836A - Paper feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper feeder provided with a rear end regulating plate with a simple composition needing no resetting even when sizes of recording mediums are changed. SOLUTION: A paper feeding tray 20 is provided with a lifting plate 22 supported rotatably around a shaft 21, and it is composed so it can approach a paper feeding roller 26 and so that a paper feeding roller 26 side tip of the lifting plate 22 is constantly energized upward by a spring. A side regulating plate 24 regulating a width direction position of a recording medium and the rear end regulating plate 25 regulating a conveyance direction rear end of the recording medium are fixedly arranged on the lifting plate 22. Since a plurality of step parts 25a, 25b, 25c, 25d, 25e or the like corresponding to the sizes of recording mediums are provided on the rear end regulating plate and a conveyance direction rear end position of at least a recording medium positioned in a lowest layer on the paper feeding tray is regulated, deviation is suppressed even when a position of the recording medium is deviated in the direction opposite to a conveyance direction following paper feeding action and the recording medium can be fed stably.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeding device for a printer, a copying machine, and the like.

[0002]

2. Description of the Related Art In a paper feeding device such as a printer or a copying machine, a paper feeding roller is disposed on a paper feeding tray for storing a recording medium, and the recording medium is supplied by rotating the paper feeding roller in frictional contact with the recording medium. A paper feeder configured to feed paper is generally used.

In this type of paper feeder, there is a paper feeder which uses a replaceable paper feed cassette as a paper feed tray for storing recording media of a plurality of sizes. Such a paper feed cassette includes a side regulating plate that regulates a position in a lateral direction with respect to the transport direction according to a size of a recording medium, and a rear end regulating plate that regulates a position rearward with respect to the transport direction. There are a type in which these regulating plates are slidable, and a type in which the regulating plates are screwed.

Further, in a printer or the like, there is a paper feeder in which the inner surface of the door becomes a paper feed tray when the door of the apparatus is opened, but in such a configuration, the position behind the recording medium in the conveyance direction is set. Generally, a rear end regulating plate for regulating is not provided.

[0005]

In such a paper feeding device, a paper feeding roller is disposed on a paper feeding tray or a paper feeding cassette for storing a recording medium, and the paper feeding roller is brought into frictional contact with the recording medium. In general, a sheet feeding device configured to feed a recording medium by rotation is operated. Each time one sheet of recording medium is fed, a push-up plate provided on the sheet feeding tray is operated to move the leading end of the sheet feeding tray in the conveying direction. The recording medium located at the uppermost part of the paper feed tray is pressed against the rotating paper feed roller, and the two are brought into frictional contact to feed paper.

In this paper feed system, the recording medium on the push-up plate tends to shift in the direction opposite to the transport direction due to the vertical movement of the push-up plate which is repeated each time one recording medium is fed. The provision of the rear end regulating plate prevents the recording medium from shifting in the direction opposite to the conveying direction.

There is also a paper feeding method which does not use the above-mentioned push-up plate. However, in order to store recording media of different sizes,
Generally, a rear end regulating plate is provided in addition to the side regulating plate. In this case, recording media of different sizes are arranged at predetermined positions, and the position of the recording medium stacked by rotation of the sheet feeding roller is changed. This is to prevent deviation.

On the other hand, the configuration having such a rear end regulating plate has some disadvantages. In other words, in the configuration in which the rear end regulating plate is screwed to the paper feed tray, every time the size of the recording medium to be stored is changed, the set screw is loosened, the rear end regulating plate is set again, and the fixing screw is tightened again. There is a disadvantage that work is required.

Further, in the configuration in which the rear end restricting plate is slid to an arbitrary position, a configuration for sliding the rear end restricting plate is required, which increases the cost and increases the space for the sliding mechanism. There are inconveniences such as necessity.

Further, in a configuration in which the door itself becomes a paper feed tray when the door of the apparatus is opened, the configuration in which the rear end regulating plate is slid to an arbitrary position may be changed depending on the maximum size of the recording medium to be stored. It became necessary to slide the regulating plate to the door, which was almost impossible in view of the mounting structure of the door.

The present invention solves the above-mentioned problems, and is applicable not only to a fixed type paper feed tray and a detachable paper feed cassette, but also to a configuration in which an apparatus door itself is used as a paper feed tray. It is an object of the present invention to provide a sheet feeding device having a low-cost rear end regulating plate with a simple configuration.

[0012]

SUMMARY OF THE INVENTION The present invention attains the above object. According to a first aspect of the present invention, there is provided a paper feed tray capable of storing a plurality of sizes of recording media, and a paper tray accommodated in the paper feed tray. A sheet feeding roller having a sheet feeding roller disposed close to the leading end of the recording medium in the conveying direction, wherein the sheet feeding tray is provided at least on the sheet feeding tray in accordance with the size of the stored recording medium. A rear end regulating member formed with a plurality of steps having different heights in the stacking direction of the recording medium for regulating the rear end position of the recording medium located in the lowermost layer in the conveying direction. And

When the sheet feeding device is based on the center sheet feeding, the rear end regulating member is provided on the bottom surface of the sheet feeding tray on the recording medium loading side along the recording medium sheet passing reference line at the center of the sheet feeding tray. It is good to arrange in.

When the sheet feeding device is based on one-sided sheet passing, the trailing end regulating member is disposed on the recording medium loading side of the sheet feeding tray along the recording medium passing reference line on the side of the sheet feeding tray. It is good to arrange on the bottom.

Further, the rear end regulating member may be formed integrally with a side regulating member arranged on the push-up plate to regulate a position in a direction perpendicular to a recording medium conveying direction.

[0016] The plurality of steps of the rear end regulating member may include:
The larger the size of the recording medium, the higher the height of the recording medium in the stacking direction, and a plurality of steps arranged rearward with respect to the recording medium transport direction.

Preferably, the height of each of the plurality of steps of the rear end regulating member is set such that the projecting corners of the plurality of steps are located substantially on a straight line.

The paper feed tray presses the leading end of the stored recording medium in the conveying direction toward the paper feed roller when feeding paper, and moves away from the paper feed roller when paper is not fed. A push-up plate constituting a part of the paper feed tray may be provided. In this case, the rear end regulating member is arranged on the push-up plate.

The paper feed tray may be fixedly arranged on the paper feeder, or may be a paper feed cassette detachable from the paper feeder.

Further, the rear end regulating member may be arranged on an extension tray attached to a paper feed tray.

Further, in the configuration in which the inner side surface of the door of the sheet feeding device is used as a sheet feeding tray, the rear end regulating member is set at a position for regulating the rear end position in the conveying direction of the recording medium when the door is opened. Shall be.

[0022]

Embodiments of the present invention will be described below.

FIG. 1 shows a printer 1 according to an embodiment of the present invention.
FIG. 11 is a cross-sectional view for explaining the outline of the configuration of the reference numeral 0. Reference numeral 11 denotes a photosensitive drum;
8 is a laser beam projection device, 18a is a laser oscillator, 18b
Denotes a scanning mirror and 19 denotes a discharge tray.

Reference numeral 20 denotes a paper feed tray, 20e denotes an extension tray, 22 denotes a push-up plate constituting a part of the paper feed tray,
Denotes a side regulating plate, 25 denotes a trailing end regulating plate, 26 denotes a sheet feeding roller, and 29 denotes a sheet feeding cassette as a second sheet feeding unit.
In the following description, it is assumed that the recording medium is fed from the paper feed tray 20.

An outline of the operation of the above configuration will be described. An electrostatic charge is applied to the photosensitive drum 11 by the main charger 12 to prepare for an image forming process. When image data output from a personal computer or the like (not shown) is input to the laser light projecting device 18, laser light modulated by the image data is projected from the laser oscillator 18a onto the photosensitive drum 11 via the scanning mirror 18b. An image latent image is formed.

On the other hand, in response to the feed command,
Is pushed up by the push-up plate 22 toward the paper feed roller 26. When the leading end of the recording medium P comes into contact with the sheet feeding roller 26, the sheet feeding of the recording medium P is started, conveyed to the timing roller 14, and temporarily stopped.

The image latent image formed on the photosensitive drum 11 is developed by the toner of the developing device 13, and the timing roller 14 is rotated by the rotation of the photosensitive drum 11 so that the toner image on the photosensitive drum 11 comes to the transfer position. Operates, and the recording medium P is transported to the transfer position. The toner image on the photosensitive drum 11 is transferred onto the recording medium P conveyed to the transfer position by the operation of the transfer roller 15. The recording medium P on which the toner image has been transferred is conveyed to the fixing device 16 where the fixing process of the toner image is performed, and is discharged to the discharge tray 19.

FIG. 2 is a perspective view illustrating the configuration of the paper feed tray and its vicinity, and FIG. 3 is a side view illustrating the configuration of the paper feed tray and related parts.

Referring to FIG. 2 and FIG.
Includes a push-up plate 22 rotatably supported around a shaft 21 a provided on the frame 21, and a leading end of the push-up plate 22 in the transport direction of the recording medium P is provided between the rear surface of the push-up plate 22 and the frame. The push-up spring 23 (see FIG. 3) disposed between the push-up plate 22 and the push-up plate 22 rotates around the shaft 21a so that the leading end of the push-up plate 22 in the conveyance direction of the recording medium P is fed to the feed roller. 26 is configured to be accessible. In addition, 21
c denotes an empty sensor for detecting whether or not the recording medium P is present on the paper feed tray 20.

The push-up plate 22 is provided with a side regulating plate 24 for regulating the position of the recording medium P in the horizontal direction, that is, the direction perpendicular to the conveying direction, so that the position can be adjusted. Is provided with a rear end regulating plate 25 for regulating the rear end position of the recording medium P in the transport direction. The rear end regulating plate 25 will be described later in detail.

At the leading end of the paper feed tray 20 in the direction of transport of the recording medium P, a paper feed roller 26 driven by a drive shaft 28 is disposed. 3 and 5, it is clear that the paper feed roller 26 is located inside the working surface 26a that comes into contact with the recording medium P and is involved in paper feeding and the working surface 26a that is not involved in paper feeding. And a non-working surface 26b. The working surface 26a has a large friction coefficient.
It is formed on a rough surface, or a friction plate made of rubber or the like is stuck thereon, so that the recording medium P is securely grasped.

A push-up plate operating cam 30 is coaxially provided on the drive shaft 28, and is engaged with push-up plate cams 22a provided on the left and right side surfaces of the push-up plate 22. The rotation of the push-up plate operation cam 30 moves the distal end of the push-up plate 22 urged upward by the push-up spring 23 via the push-up plate cam 22a in a direction to approach and separate from the sheet feeding roller 26.

A separating table 41 is disposed at a position facing the paper feed roller 26, and a separating pad 41 is provided on the upper surface of the separating table 41.
p is provided so that the recording medium P fed between the sheet feeding roller 26 and the sheet feeding roller 26 is separated, and the recording medium P is fed one by one even when a plurality of recording mediums P are multi-fed. Activate The material of the separation pad 41p is a material having a large coefficient of friction.
For example, rubber or the like is used.

FIG. 4 is a front view for explaining a drive mechanism of a drive shaft 28 for driving the paper feed roller 26. FIG. 4A shows a non-drive state in which the drive shaft 28 is separated from a drive source. FIG. 4B shows a driving state in which the driving shaft 28 is coupled to a driving source.

4 (a) and 4 (b), a toothless gear 31 having a toothless portion 31a and a cam 32 having a stepped portion 32a are coaxially fixed to the drive shaft 28. , The pin 32p on the cam 32 and the pin 3 on the frame (not shown)
A spring member 32c is bridged between the cam 32 and 2q, and when in the state shown in FIG. 4A, the cam 32 is urged to rotate clockwise (direction of arrow a).

A drive gear 35 is attached to a main drive shaft 38 extending from a main motor of the apparatus main body (not shown).
b.

On the other hand, a solenoid mechanism 33 is arranged close to the cam 32. The solenoid mechanism 33 urges the yoke 33a, the lever 33b rotatably held around a pin 33p provided on the yoke 33a, and the locking portion 33c at the tip of the lever 33b toward the step 32a of the cam 32. A spring member 33d and an exciting coil 33e are provided.

In the above configuration, in the state of waiting for sheet feeding, each member is at the position shown in FIG. That is, since the excitation coil 33e is in a non-excitation state, the lever 33
b is rotated clockwise by the spring member 33d,
The locking portion 33c at the tip of 3b is engaged with the step 32a of the cam 32.

For this reason, the cam 3 urged by the spring member 32c to rotate clockwise (direction of arrow a).
2 is prevented, the toothless portion 31a of the toothless gear 31 is located at a position facing the drive gear 35, and the drive gear 35 and the toothless gear 31 are not meshed with each other. Is not transmitted to the drive shaft 28, and the paper feed roller 26 stops rotating.

Next, when the sheet feeding command signal is output and the exciting coil 33e is excited, the lever 33b is
The lever 33b rotates counterclockwise against the urging force of the lever 33b.
The locking portion 33c at the tip of the cam 32 is separated from the step portion 32a of the cam 32.

Therefore, as shown in FIG. 4B, the cam 32 is rotated clockwise (in the direction of arrow a) by the urging force of the spring member 32c, and the tooth 31b of the toothless gear 31 is driven by the drive gear. It moves to the position where it meshes with 35. Thus, the rotational power of the main motor (not shown) is transmitted from the drive gear 35 to the drive shaft 28 via the toothless gear 31, and
Is rotated to feed paper.

According to the above configuration, when the exciting coil 33e of the solenoid mechanism 33 is excited based on the sheet feed command signal, the drive shaft 28 makes one rotation each time the exciting coil 33e is excited, and the push-up plate operating cam 30 is pushed up. By operating the plate cam 22a, the push-up plate 22
Of the push-up plate 2
The recording medium P on 2 is fed by the rotation of the feed roller 26.

When the paper feeding is completed, the exciting coil 33e is de-energized, and the locking portion 33c at the tip of the lever 33b is
Engage with the second step 32a. The rotation of the cam 32 is prevented, the toothless portion 31a of the toothless gear 31 also stops at the position shown in FIG. 4A, and the drive gear 35 and the toothless gear 31 do not mesh with each other. Then, the paper feed roller 26 stops rotating and returns to the paper feed standby state.

Next, the rear end regulating plate 25 for regulating the rear end position of the recording medium P in the transport direction will be described. Recording medium P
When the sheet is fed, the push-up plate of the sheet feed tray moves up and down every time sheet feeding is performed. This up-and-down movement gradually moves the recording medium P on the push-up plate in the direction opposite to the transport direction. Therefore, if the rear end position of the recording medium P is not regulated, the recording medium P does not contact the sheet feeding roller, and the sheet feeding fails.

In order to solve this inconvenience, a rear end regulating plate is provided. However, since the lowermost recording medium P of the push-up plate is most easily moved, at least the rear end of the lowermost recording medium P can be regulated. Proved to be enough.

FIG. 5 is a sectional view for explaining the structure of the rear end regulating plate 25. The rear end regulating plate 25 has a plurality of steps 25a, 25b, 25 corresponding to the size of the loaded recording medium P.
c, 25d, 25e, and the like are provided, and are fixedly disposed at a central portion above the push-up plate 22. The position of the step is set to a position retracted by the length of the recording medium P loaded from the leading end of the push-up plate in the transport direction.

For example, the step 25a shown in FIG. 5 is a step corresponding to a 5.5 × 8.5 inch paper size and horizontally (indicated by Y) recording medium, and the step 25b is a sheet of A5 size. Step, step 2 corresponding to the horizontal (Y) recording medium
5c is a stepped portion corresponding to a recording medium of B5 size and horizontally (Y), a stepped portion 25d is a recording medium of A4 size and horizontally (Y), and a stepped portion 25e is 8. This is a step portion corresponding to a recording medium of 5 × 11 inches and placed horizontally (Y).

FIG. 6 is a plan view for explaining another example of the configuration of the rear end regulating plate, which is suitable for a central paper feed reference type paper feed tray with the center of the paper feed tray as the paper feed reference. In addition to fixedly arranging a rear end regulating plate 25 having a step at the center portion on the push-up plate 22, a step 24 is also provided at a portion 24a of the two side regulating plates 24 arranged on the left and right in parallel with the push-up plate 22. Is provided.

According to this configuration, the rear end of the recording medium P is
Rear end regulating plate 2 arranged at the center on top of push-up plate 22
5, the two side regulating plates 24 arranged on the left and right sides also regulate, so that the rear end position of the recording medium P can be regulated reliably.

FIG. 7 is also a plan view for explaining another example of the configuration of the trailing end regulating plate. This configuration is suitable for a paper tray, and has a step on the push-up plate 22 on the side serving as a paper passing reference.

FIG. 8 is a side view for explaining the shape of the step of the rear end regulating plate. As described above, the position of the step is set to a position retracted by the length of the recording medium P from the leading end of the push-up plate in the transport direction, so that the large-sized recording medium P is arranged across a plurality of steps. Will be.

At this time, the interval between the steps is determined by the size of the recording medium P and is not a fixed interval. Therefore, when all the heights h of the plurality of steps are made uniform, (a) in FIG. ), A plurality of steps 25a, 25b,
The corners of 25c, 25d and 25e are not aligned on the straight line L,
The surface of the recording medium P arranged over a plurality of steps may undulate, which may hinder stable paper feeding.

Therefore, as shown in FIG. 8B, a plurality of steps 25a, 25b, 25c, 25d,
The heights of the steps 25a to 25e are not uniform, and the heights of the steps are varied as h1 to h5.
The corners of 5e were arranged substantially on the straight line L. In addition,
For the step portion for the minimum size recording medium, the height of the step portion may be reduced, or may be set one step lower than the line L on which the corners of the step portion are substantially aligned.

As described above, the plurality of steps of the rear end regulating plate 25 become larger as the size of the loaded recording medium P increases.
It is assumed that the height of the recording medium in the stacking direction is high and that the recording medium is arranged rearward with respect to the conveying direction of the recording medium.

FIG. 9 is a sectional view for explaining a step portion of the rear end regulating plate when a recording medium having a size larger than the size of the push-up plate 22 is used. The push-up plate 2 is provided on the paper feed tray 20.
An extension tray 20e is attached to the rear of the recording medium 2, that is, on the opposite side to the recording medium transport direction, so that a large-sized recording medium can be loaded.

The extension tray 20e is mounted on the paper feed tray 20 independently of the push-up plate 22, and the movement of the tip of the push-up plate 22 that moves up and down each time paper is fed is not transmitted. In order to restrict the backward movement of the recording medium P due to the movement, the ribs 20f of the extension tray 20e have the same steps 25f, 25g, and 25 as those provided on the push-up plate 22 described above.
h, 25i and 25j are formed.

With this configuration, the trailing edge position can be regulated even for a large-sized recording medium positioned above the extension tray 20e.

In the above-described embodiment, the paper feed device having the rear end regulating plate is described as the paper feed device in which the rear end regulating plate is applied to the paper feed tray having the push-up plate. The regulation can also be applied to a paper feeder that does not have a push-up plate in the paper feed tray, a fixed paper feed tray fixed to the paper feeder, or a paper feeder that is detachable from the paper feeder. It goes without saying that the present invention can be applied not only to the cassette but also to a sheet feeding device configured to use the door itself of the device as a sheet feeding tray.

[0059]

As described above in detail, according to the present invention, the rear end regulating plate is formed with a plurality of steps having different heights in the stacking direction of the recording medium in accordance with the size of the recording medium to be stored. Since at least the rear end position in the transport direction of the recording medium positioned at the lowermost layer on the paper feed tray is regulated, the recording paper stacked on the paper Even if the position of the medium is shifted in the direction opposite to the transport direction, the shift can be suppressed by the rear end regulating plate fixedly arranged on the sheet feeding tray, and the recording medium can be stably fed.

According to this configuration, a complicated operation of resetting the position of the rear end regulating plate even when the size of the recording medium is changed becomes unnecessary, and a configuration for sliding the rear end regulating plate to an arbitrary position is also omitted. This eliminates the need for space for the slide mechanism. Further, even in a configuration in which the door itself of the apparatus serves as a paper feed tray, the rear end regulating plate can be easily provided on the door.

As described above, according to the present invention, it is possible to provide a paper feeder having a rear end regulating plate capable of always stably feeding a recording medium with a simple configuration, low cost, and low cost.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an outline of a configuration of a main part of a printer according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating a configuration of a sheet feeding tray and its vicinity.

FIG. 3 is a side view illustrating the configuration of a paper feed tray and related parts.

FIG. 4 is a front view illustrating a drive mechanism of a drive shaft that drives a paper feed roller.

FIG. 5 is a cross-sectional view illustrating a configuration of a rear end regulating plate.

FIG. 6 is a plan view illustrating another configuration example of the rear end regulating plate.

FIG. 7 is a plan view illustrating another configuration example of the rear end regulating plate.

FIG. 8 is a side view illustrating the shape of a step portion of the rear end regulating plate.

FIG. 9 is a cross-sectional view illustrating a step portion of a rear end regulating plate for a large-sized recording medium.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Printer 11 Photoreceptor drum 12 Main charger 13 Developing device 14 Timing roller 15 Transfer roller 16 Fixing device 18 Laser beam projection device 18a Laser oscillator 18b Scanning mirror 19 Discharge tray 20 Feed tray 20e Extension tray 21 Frame 22 Push-up plate 22a Push-up plate Cam 23 Push-up spring 24 Side regulating plate 25 Rear end regulating plate 25a, 25b, 25c, 25d, 25e Step 25f, 25g, 25h, 25i, 25j Step 26 Feed roller 28 Drive shaft 29 Feed cassette 30 Push-up plate operation Cam 31 Missing tooth gear 31a Missing tooth portion 31b Tooth portion 32 Cam 33 Solenoid mechanism 33a Yoke 33b Lever 33c Locking portion 33d Spring member 33e Exciting coil 35 Drive gear 38 Main drive shaft 41 Release table 41p Release pad

Claims (11)

[Claims] 1. A paper feeder, comprising: a paper feed tray capable of storing a plurality of sizes of recording media; and a paper feed roller disposed near a leading end of the recording medium stored in the paper feed tray in the transport direction. In the paper device, the paper feed tray is configured to control a rear end position in a transport direction of a recording medium positioned at least in a lowermost layer on the paper feed tray in accordance with a size of a stored recording medium. A sheet feeding device, comprising: a rear end regulating member formed with a plurality of steps each having a different height in a stacking direction of a medium. 2. The paper feed tray according to claim 1, wherein the rear end regulating member is disposed on a bottom surface of the paper feed tray on a recording medium loading side along a recording medium passing reference line in a central portion of the paper feed tray.
Paper feeder as described. 3. The paper feed tray according to claim 1, wherein the rear end regulating member is disposed on a bottom surface of the paper feed tray on the side where the recording medium is stacked along a recording medium passing reference line of the side of the paper feed tray. Paper feeder as described. 4. The apparatus according to claim 1, wherein the rear end regulating member is integrally formed with a side regulating member disposed on the push-up plate and regulating a position in a direction perpendicular to a recording medium conveying direction. Paper feeder as described. 5. The plurality of steps of the rear end regulating member, the height of which in the stacking direction of the recording medium increases as the size of the recording medium increases, and the plurality of steps arranged rearward in the recording medium transport direction. The sheet feeding device according to claim 1, wherein the sheet feeding device is a stepped portion. 6. The height of each of the plurality of steps of the rear end regulating member is set such that the protruding corners of the plurality of steps are located substantially on a straight line. The paper feeding device according to claim 1. 7. The paper feed tray further presses the leading end of the stored recording medium in the conveyance direction toward the paper feed roller when feeding paper, and moves in a direction away from the paper feed roller when paper is not fed. The sheet feeding device according to claim 1, further comprising a push-up plate that constitutes a part of the sheet feed tray, wherein the rear end regulating member is disposed on the push-up plate. . 8. The paper feeding device according to claim 1, wherein the paper feeding tray is fixedly arranged on the paper feeding device. 9. The paper feeding device according to claim 1, wherein the paper feeding tray is a paper feeding cassette detachable from the paper feeding device. 10. The sheet feeding device according to claim 1, wherein the rear end regulating member is disposed on an extension tray attached to the sheet feeding tray. 11. In a configuration in which an inner side surface of a door of a paper feeding device is a paper feeding tray, the rear end regulating member is set to a position that regulates a rear end position in a conveyance direction of a recording medium when the door is opened. The sheet feeding device according to any one of claims 1 to 6, wherein: