JP2003246480A - Image forming device - Google Patents

Abstract

(57) [Problem] To prevent a conveyance failure of a sheet material caused by the leading edge of the sheet material climbing on a separation slope and displacing a stacking position when the sheet material stacking device is inserted into an image forming apparatus main body. I do. A regulating member is formed by projecting a part of a main body of an image forming apparatus downward, and a leading end portion of the regulating member is located at a leading end side of an uppermost sheet material on a sheet material stacking device from above. It should be arranged at the position facing. When the sheet material stacking device 3 is inserted in the direction of arrow K and stopped at a predetermined position, the sheet material S rides up along the separation slope 4 due to inertia, but comes into contact with the regulating member 10 to be further moved. The vehicle is stopped without climbing, and is returned to the normal position by the elastic force of the sheet material itself.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a printer, a copying machine and a facsimile.

[0002]

2. Description of the Related Art FIG. 6 shows the overall structure of a conventional laser beam printer (hereinafter referred to as "image forming apparatus") using an electrophotographic process.

In FIG. 1, reference numeral 1 is an image forming apparatus main body, 2 is a movably provided feeding roller, and 3 is a detachably mounted sheet material S on the image forming apparatus main body 1 for stacking the sheet material S. The sheet material stacking devices 4 and 4 respectively indicate inclined slopes for separating the sheet materials S provided in the image forming apparatus main body one by one.

An arrow K in the figure indicates the insertion direction of the sheet material stacking device 3 into the image forming apparatus main body 1.

Reference numeral 5 indicates a process cartridge. The process cartridge 5 includes at least a photosensitive drum 5a, a developing device (not shown), a charging device (not shown), a toner accommodating portion (not shown), and a drum cleaning. A device (not shown) is included.

Reference numeral 6 indicates a fixing device. The fixing device 6 is composed of a fixing roller 6a containing a heater and a pressure roller 6b. The toner image on the sheet S is fixed to the fixing roller 6a and the applying roller. It is melted and fixed by heat and pressure applied from the pressure roller 6b. Reference numerals 7a and 7b denote discharge roller pairs.

Reference numeral 8 is a scanner unit (exposure device) for writing an electrostatic latent image on the photosensitive drum 5a by reflecting light generated by a laser oscillator (not shown) by a rotating mirror. Reference numeral 9 denotes a paper discharge tray for stacking the sheet materials S discharged by the paper discharge roller pairs 7a and 7b.

Next, an image forming operation in the image forming apparatus having the above-mentioned structure will be described. When a print signal (image forming signal) is input by a host computer (not shown), the sheet material S is taken out from the sheet material stacking device 3 by the feeding roller 2 and separated one by one by the separation slope 4. Be transported.

The electrostatic latent image formed by the scanner unit 8 on the photosensitive drum 5a after the uniform charging is developed as a toner image after toner is attached by the developing device,
The image is transferred onto the sheet material S.

The sheet material S to which the toner image is transferred is discharged onto the discharge tray 9 by the discharge rollers 7a and 7b after the toner image is fixed on the surface by the fixing device 6. This completes the image formation.

[0011]

However, in the image forming apparatus having the structure shown in the conventional example, the following problems occur when the sheet material stacking device 3 is inserted into the image forming device main body 1 so as to be strongly pushed. May occur.

When the sheet material stacking device 3 is inserted to a predetermined position in the image forming apparatus main body 1, the sheet material stacking device 3
Will stop. At this time, the sheet material S moving together with the sheet material stacking device 3 moves toward the slope provided on the insertion direction side due to the inertial force. As a result, as shown in FIG. 7, the sheet material S shifts from the regular stacking position to the separation slope 4 side, and the leading end of the sheet material rides on the separation slope 4.

At this time, if the amount of deformation of the leading end of the sheet material is small, the sheet material S is pushed back by the elasticity of the sheet material S itself to return to the regular stacking position.

However, when the amount of deformation of the leading edge of the sheet material is large, the elastic deformation exceeds the limit, causing buckling and the like, and it is not possible to return to the regular stacking position, and it remains at that position. Will end up.

When the feeding operation of the sheet material S is performed in this state, the sheet material S is not separated by the separation slope 4 and there is a risk of causing feeding failure such as double feeding.

The present invention has been made in view of the above circumstances, and the sheet material is caused by the leading edge of the sheet material riding on the separation slope when the sheet material stacking device is inserted into the main body of the image forming apparatus. It is an object of the present invention to provide an image forming apparatus capable of preventing the conveyance failure of the above.

[0017]

The invention according to claim 1 is
A sheet material stacking device that stores sheet materials in a stacked state and is insertable in the sheet material feeding direction with respect to the image forming apparatus main body,
Movable feeding means for feeding the sheet material to the uppermost position on the sheet material stacking device, and the position of the leading end of the sheet material stacked on the sheet material stacking device provided on the image forming apparatus main body side And a separation slope for separating the sheet materials one by one when the sheet material is fed by the feeding means, in the image forming apparatus main body side,
When the sheet material stacking device is inserted, a regulation member is provided to prevent the leading edge of the stacked sheet material from riding on the separation slope and disturbing the posture, and the leading end portion of the regulating member is stacked on the sheet material stacking device. The uppermost sheet material among the sheet materials is arranged at a position facing the leading end portion in the sheet material transport direction from above.

According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the regulating member is a protrusion provided on the image forming apparatus main body side.

According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the regulating member is composed of a member having elasticity.

According to a fourth aspect of the present invention, in the image forming apparatus according to the first aspect, the regulating member is rotatably supported by the leading end portion and is a roller member which is driven to rotate by a sheet material at the time of sheet feeding. It is characterized by having.

According to a fifth aspect of the present invention, in the image forming apparatus according to the first aspect, the regulating member is swingably attached to the main body of the image forming apparatus, and when the sheet material is fed. It is characterized by retreating to the retreat position.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In addition, in each of the drawings, components denoted by the same reference numerals have similar configurations or actions, and repeated description thereof will be appropriately omitted.

<First Embodiment> FIG. 1 shows an example of a sheet material feeding apparatus according to the present invention and an image forming apparatus having the same. The figure is a vertical cross-sectional view of the image forming apparatus as viewed from the front side. It should be noted that members having the same configurations and functions as those of the image forming apparatus shown in FIGS. 6 and 7 described above are denoted by the same reference numerals, and description thereof will be appropriately omitted. Reference numeral 13 in the figure denotes a transfer roller for transferring the toner image formed on the photosensitive drum 5a onto the sheet material S.
Reference numeral 14 indicates that the base end side (right end side in the figure) is swingably supported by the image forming apparatus main body 1, and the paper feed roller 2 is rotatably supported by the tip end side (left end side in the figure). The arm member is shown.

In this embodiment, in order to prevent the posture of the sheet material S from being disturbed when the sheet material stacking device 3 is pushed (inserted) in the image forming apparatus main body 1 in the direction of arrow K, A regulation member 10 is provided. In the present embodiment, the regulating member 10 is the image forming apparatus main body 1
It is configured by projecting a part of the component parts.

The regulating member 10 has a tip portion (lower end portion) 1
0a is a sheet material S stacked on the sheet material stacking device 3.
Is disposed at a position facing the leading end of the uppermost sheet material S in the transport direction. Tip portion 10 of the regulating member 10
The height position of a is located near the uppermost sheet material S. That is, when the sheet material stacking device 3 in a state in which the sheet materials S are fully loaded is inserted into the image forming apparatus main body 1, the leading end portion 10 a of the regulating member 10 is the uppermost sheet material S on the sheet material stacking device 3. It is placed in a position where there is a slight gap between

Next, the behavior of the sheet material S when the sheet material stacking device 3 loaded with the sheet material S is inserted into the image forming apparatus main body 1 and the behavior change of the sheet material S by the regulating member 10 will be described.

When the sheet material stacking device 3 is inserted in the same direction as the conveying direction of the sheet material S and stopped at a predetermined position in the image forming apparatus main body 1, the sheet material S is, as shown by the dotted line in FIG. The tip end is separated by the inertial force due to its own weight.
Ride along.

When the leading edge of the sheet material S has climbed up to an arbitrary position on the separation slope 4, the leading edge side of the uppermost sheet material S contacts the leading edge 10a of the regulating member 10 and is stopped without riding further. .

The sheet material S whose riding on the separation slope 4 has been stopped is a regular loading position (in FIG. 1) due to the repulsive force generated by the fall of the riding portion due to its own weight and the accumulation of elastic force due to the curved tip. (Solid line) will push itself back.

As described above, even if the sheet material S rides on the separation slope 4 due to the impact when the sheet material stacking device 3 is inserted, it is returned to the regular stacking position by the regulating member 10, so that the stable stacking posture is obtained. Can be held.

<Second Embodiment> FIG. 2 shows a second embodiment. In the present embodiment, the regulation member 15 is composed of a member having elasticity. The configuration other than the regulation member 15 is the same as that of the image forming apparatus according to the first embodiment described above.

The restricting member 15 of the present embodiment is formed in a J shape as a whole, and with respect to the uppermost sheet material S among the plurality of sheet materials S stacked in the sheet material stacking device 3. , Is arranged on the image forming apparatus main body 1 side so as to face the leading end in the transport direction. The tip portion 15a of the regulating member 15 is arranged so as to be located near the uppermost sheet material surface of the uppermost sheet material S.

The material forming the regulating member 15 is
Resin, metal, graphite or the like having a high elasticity is used.

Next, the behavior of the sheet material S when the sheet material stacking device 3 loaded with the sheet material S is inserted into the image forming apparatus main body 1 and the behavior change of the sheet material S by the regulating member 15 will be described. .

When the sheet material stacking device 3 is inserted in the same direction as the conveying direction and stopped at a predetermined position in the image forming apparatus main body 1, as shown by the dotted line in FIG. The tip portion thereof rides up along the separation slope 4.

When the leading end of the sheet material S rides up to an arbitrary position on the separation slope 4, the leading end side of the uppermost sheet material S contacts the leading end 15a of the regulating member 15.

At this time, since the regulating member 15 is an elastic body,
The separation slope 4 of the sheet material S is curved by the moving force of the sheet material S (one-dot chain line in FIG. 2) and reaches a certain deformation amount.
Stop riding.

The sheet material S whose riding on the separation slope 4 has been stopped is a regular loading position (in FIG. 2) due to the repulsive force generated by the fall of the riding portion due to its own weight and the accumulation of elastic force due to the curved tip. (Solid line) will push itself back.

As described above, even if the sheet material S rides on the separation slope 4 due to the impact when the sheet material stacking device 3 is inserted, it is returned to the regular stacking position by the restricting member 15, so that the stable stacking posture is achieved. Can be held.

Further, in the present embodiment, even when the sheet material S having a small thickness and poor elasticity due to deformation is loaded, the sheet material S is pushed back to the normal position by the repulsive force due to the elasticity of the regulating member 15. Therefore, it is possible to maintain a stable stacking position for various sheet materials S.

<Third Embodiment> FIG. 3 shows a third embodiment. In the present embodiment, the regulation member 16 has a protrusion 16a and a roller member 17. The configuration other than the regulation member 16 is the same as that of the image forming apparatus according to the first embodiment described above.

The projecting portion 16a of the regulating member 16 is formed by projecting a part of the image forming apparatus main body 1, and the leading end portion thereof is the uppermost sheet material S stacked on the sheet material stacking device 3. It is arranged so as to face the front end portion in the conveyance direction from above. Further, a roller member 17 is rotatably supported at the tip (lower end) of the protrusion 16a.

Next, the behavior of the sheet material S when the sheet material stacking device 3 loaded with the sheet material S is inserted into the image forming apparatus main body 1 and the behavior change of the sheet material S by the regulating member 16 will be described.

When the sheet material stacking device 3 is inserted in the same direction as the sheet material conveying direction and stopped at a predetermined position in the image forming apparatus main body 1, the leading end portion of the sheet material S is separated by the inertia force due to its own weight. Ride along the slope 4.

When the leading end of the sheet material S runs up to the position where the separation slope 4 is present, the uppermost sheet material S comes into contact with the roller member 17 supported by the leading end of the projecting portion 16a, and runs further. To stop without.

The sheet material S that has stopped riding on the separation slope 4 is pushed back to the regular loading position by the repulsive force generated by the fall of the riding portion due to its own weight and the elastic force accumulated due to the curved tip portion. It will be.

Next, the behavior of the roller member 17 when the sheet material S is fed will be described. Sheet material stacking device 3
The uppermost sheet material S stacked on the sheet is separated one by one by the separation slope 4, and is fed by the feeding roller 2.

The sheet material S being fed advances while being in contact with the roller member 17, and this roller member 17 is moved by the sheet material S during the contact with the sheet material S being fed. Rotates following the direction. Therefore, the regulation member 16 hardly imparts the conveyance resistance to the conveyed sheet material S.

As described above, even if the sheet material S rides on the separation slope 4 due to the impact when the sheet material stacking device 3 is inserted, it is returned to the regular stacking position by the restricting member 16, so that the stable stacking posture is achieved. Can be held.

Further, since the sheet material S being conveyed is conveyed while being in contact with the roller member 17 which can be driven and rotated, the influence of the contact resistance on the image forming apparatus (for example, the transfer of the toner image) can be reduced. It is possible to provide an image forming apparatus that can always maintain a stable stacking position and can form a high-quality image.

<Fourth Embodiment> FIGS. 4 and 5 show a fourth embodiment. The regulating member 18 in the present embodiment is configured to be rotatable (swingable). The regulation member 1
Other configurations except 8 are the same as those of the image forming apparatus according to the first embodiment described above.

The restricting member 18 of this embodiment is formed in a J shape as a whole, and its base end is rotatably supported by a shaft 18b provided on the image forming apparatus main body 1 side. . Further, the leading end portion 18a of the regulation member 18 is arranged at a position facing the leading end portion on the transport direction side of the uppermost sheet material S on the sheet material stacking device 3 from above.

Next, the behavior of the sheet material S when the sheet material stacking device 3 loaded with the sheet material S is inserted into the image forming apparatus main body 1, and the sheet material S by the regulating member 18.
The behavior change of is explained.

When the sheet material stacking device 3 is inserted in the same direction as the sheet material conveying direction and stopped at a predetermined position in the image forming apparatus main body 1, the sheet material S has its tip portion separated by the inertial force due to its own weight. Ride along.

When the leading end of the sheet material S runs up to the position where the separation slope 4 is present, the uppermost sheet material S contacts the leading end 18a of the regulating member 18 and stops without riding further.

The sheet material S that has stopped riding on the separation slope 4 is dropped by the weight of the riding portion and the repulsive force generated by the accumulation of elastic force due to the bending of the tip portion, and is indicated by the normal line in FIG. It will push itself back to the loading position of.

Next, the behavior of the regulating member 18 when the sheet material S is fed will be described.

The feeding roller 2 moves to the feeding position for feeding the sheet material S. At this time, the regulation member 18
As shown in FIG. 5, it moves from the position shown by the dotted line to the upper retracted position shown by the solid line.

When the uppermost sheet material S stacked on the sheet material stacking device 3 is separated one by one by the separation slope 4 and is fed by the feeding roller 2, the regulating member 18 is already in the retracted position. Since the sheet material has been moved to, the sheet material S being fed does not come into contact with it.

From the above, even if the sheet material S rides on the separation slope 4 due to the impact when the sheet material stacking device 3 is inserted, it is returned to the regular stacking position by the restricting member 18, so that a stable stacking posture is obtained. Can be held.

Further, the sheet material S being conveyed is restricted by the regulating member 1.
Since the sheet material S is not in contact with the sheet 8 and the contact resistance does not affect the image formation, it is possible to always keep the sheet material S in a stable stacking position and form a high-quality image.

[0062]

As described above, according to the present invention,
When the sheet material stacking device is inserted into the main body of the image forming apparatus, it is possible to prevent the leading edge of the sheet material from climbing on the separation slope and shifting the stacking position, thereby effectively preventing the defective conveyance of the sheet material. it can.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a schematic configuration of an image forming apparatus according to a first embodiment.

FIG. 2 is a vertical sectional view showing a schematic configuration of an image forming apparatus according to a second embodiment.

FIG. 3 is a vertical sectional view showing a schematic configuration of an image forming apparatus according to a third embodiment.

FIG. 4 is a vertical sectional view showing a schematic configuration of an image forming apparatus according to a fourth embodiment.

FIG. 5 is a vertical sectional view for explaining the operation of the image forming apparatus according to the fourth embodiment.

FIG. 6 is a vertical sectional view showing a schematic configuration of a conventional image forming apparatus.

FIG. 7 is a diagram for explaining a stacking position deviation of a sheet material on a sheet material stacking device in a conventional image forming apparatus.

[Explanation of symbols]

1 Image forming device body 2 Feeding means (feeding roller) 3 sheet material loading device 4 separation slopes 10, 15, 16, 18 Control member 10a, 15a, 18a Restriction member tip 17 Roller member S sheet material

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Claims (5)

[Claims] 1. A sheet material stacking device in which sheet materials are stored in a stacked state and can be inserted into and removed from a main body of an image forming apparatus in a sheet material feeding direction, and a sheet material is placed at the top of the sheet material stacking device. A movable feeding means for feeding and a position of the leading end of the sheet material stacked on the sheet material stacking device provided on the image forming apparatus main body side is regulated, and the sheet material is fed by the feeding means. An image forming apparatus having a separation slope for separating the sheet materials one by one when the sheet material stacking device is inserted into the main body of the image forming apparatus, and the tip of the stacked sheet material rides on the separation slope. A regulation member for preventing the posture from being disturbed is provided, and the tip end portion of the regulation member is the topmost sheet material among the sheet materials stacked in the sheet material stacking device with respect to the tip end portion in the sheet material conveyance direction. , Facing from above That is disposed in a position, the image forming apparatus characterized by. 2. The image forming apparatus according to claim 1, wherein the restriction member is a protrusion provided on the image forming apparatus main body side. 3. The image forming apparatus according to claim 2, wherein the restriction member is made of a member having elasticity. 4. The image forming apparatus according to claim 1, wherein the regulating member includes a roller member that is rotatably supported by the leading end portion and that is driven and rotated by a sheet material at the time of sheet feeding. . 5. The regulating member is swingably attached to the image forming apparatus main body, and retracts to a retracted position when a sheet material is fed. Image forming apparatus.