JP4405192B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus represented by a copying machine, a printer, and the like.
[0002]
[Prior art]
Some image forming apparatuses represented by copying machines, printers, and the like are provided with a paper supply unit that can be pulled out from the main body in the horizontal direction. Sheets are stacked and stored in the sheet supply unit. This paper supply unit is often provided below the inside of the image forming apparatus main body, and a paper transport unit may be formed on the ceiling of the space that houses the paper supply unit. Such a configuration is often used when a duplex printing unit is provided in an image forming apparatus.
[0003]
In the double-sided printing unit, the paper on which one side is printed is pulled out from the fixing unit by a roller, and the other side can be printed by rotating the roller in the reverse direction to switch the paper transport direction. The paper transport unit is used to send the paper whose transport direction has been switched in this way to the transfer unit again. An example of an image forming apparatus having such a paper supply unit and a double-sided printing unit can be seen in Patent Document 1.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-183554
[Problems to be solved by the invention]
In the image forming apparatus described in Patent Document 1, the double-sided printing unit is unitized so that it can be pulled out from the main body. When a paper jam occurs in the double-sided printing unit, the double-sided printing unit is pulled out from the main body and jammed. Process. However, such a jam processing method cannot be adopted in a model in which the duplex printing unit is fixed to the apparatus main body.
[0006]
FIG. 4 shows a printer as an example of a conventional image forming apparatus in which a double-sided printing unit is fixed to the main body. FIG. 4 is a schematic vertical sectional view showing a schematic structure of the printer. A paper cassette 10 serving as a paper supply unit is disposed below the inside of the main body 2 of the printer 1. The paper cassette 10 can be extracted from the main body 2 in the horizontal direction (in the direction of the arrow in the figure), and the paper P is stacked and accommodated therein. The paper P is sent out toward the upper right of the paper cassette 10 in FIG. Subsequently, a registration roller 3, an image forming unit 4, a fixing unit 5, a branching unit 6, and a sheet discharging unit 7 are disposed downstream of the sheet conveyance direction. The paper discharge unit 7 is provided on the upper surface of the main body 2.
[0007]
A duplex printing unit 20 is disposed above the paper cassette 10 and below the image forming unit 4 and the fixing unit 5. When performing duplex printing, the transport direction of the paper P that has passed through the branching section 6 is switched to feed the paper to the duplex printing section 20 and pass over the paper guide member 22 provided at the bottom of the paper transport section 21. Then, the sheet P is conveyed again to the image forming unit 4 through the registration roller 3.
[0008]
5 and 6 show a schematic configuration of the paper guide member 22 and its periphery. FIG. 5 is a schematic perspective view of the paper guide member 22 and its periphery as viewed from below, and FIG. 6 is a schematic vertical sectional view showing the paper guide position and jam processing position of the paper guide member 22. FIG. 6A shows a state where the paper guide member 22 is in the paper guide position, and FIG. 6B shows a state where the paper guide member 22 is in the jam processing position. The paper guide member 22 can be lowered about the fulcrum F by holding the knob 23 by hand (see FIG. 6B). When a paper jam occurs in the paper transport unit 21, the paper guide member 22 can be lowered into the space after the paper cassette 10 serving as the paper supply unit is removed to perform jam processing. The fulcrum F is provided with a torsion spring 24, and the paper guide member 22 is always biased to the paper guide position. In addition, a conveyance roller 25 is embedded in the paper guide member 22 so as to be exposed on both the lower surface and the upper surface (paper conveyance surface).
[0009]
In the structure of the paper transport unit 21 of the printer 1, the user removes the jammed paper and then releases the knob 23 to set the paper guide member 22 at the paper guide position by the action of the torsion spring 24. become. Therefore, when the spring force of the spring is reduced due to secular change or the like, the paper guide member 22 cannot be constantly urged to the paper guide position. As a result, the paper guide member 22 is lowered by its own weight, and there is a high possibility that paper conveyance failure and paper jam frequently occur.
[0010]
The present invention has been made in view of the above points, and includes a paper supply unit that can be pulled out from the main body in a horizontal direction. In the paper transfer unit disposed above the paper supply unit, a paper transfer failure or a paper jam occurs. It is an object of the present invention to provide a highly reliable image forming apparatus that does not cause any problems.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, in an image forming apparatus including a paper supply unit that can be extracted from a main body in a horizontal direction, and a paper transport unit disposed above the paper supply unit,
A paper guide member that can be lowered into the space after the paper supply unit is pulled out to perform paper jam processing is provided at the lowermost part of the paper transport unit. The paper supply unit is provided with a support surface that contacts and supports the paper guide member from below when the paper supply unit is inserted into the main body. The paper guide member is brought into contact with the paper supply member on the downstream side in the insertion direction of the paper supply unit with respect to the fulcrum shaft of the paper guide member provided in a direction orthogonal to the transport direction and the attachment / detachment direction of the paper supply unit.
[0012]
According to this configuration, it is possible to hold the paper guide member at the paper guide position even when the spring force of the spring is reduced. Therefore, since the paper transport unit is configured correctly, paper transport failure and paper jam do not occur. Thereby, a highly reliable image forming apparatus can be provided.
[0013]
Further, the paper guide member is in contact with the support surface of the paper supply unit via a rolling member.
[0014]
According to this configuration, when the paper supply unit is inserted into the image forming apparatus main body, the paper guide member can be held at the correct paper guide position, and the paper supply unit can be smoothly inserted. In addition, no significant wear occurs at the portion where the paper guide member and the paper supply unit come into contact with each other. Therefore, dust due to wear does not occur, and the paper stored in the paper supply unit can be managed cleanly.
[0015]
Further, the rolling member is supported by the paper guide member via an elastic member.
[0016]
According to this configuration, even when the paper transport unit or the paper supply unit rattles or the like due to secular change due to long-term use of the image forming apparatus, the insertion of the paper supply unit becomes tight. There is nothing. Therefore, it is possible to always smoothly insert the paper supply unit.
[0017]
Further, at least one of the support surface of the paper supply unit and the contact surface of the rolling member with the support surface is made of an elastic member.
[0018]
According to this configuration, the insertion of the paper supply unit can be prevented from being cramped, and the friction generated between the support surface of the paper supply unit and the rolling member can be further reduced. Therefore, it is possible to provide a high-performance image forming apparatus that can smoothly insert the paper supply unit indefinitely and can cleanly manage the paper stored therein.
[0019]
Further, the paper guide member is in contact with a plurality of support surfaces of the paper supply unit.
[0020]
According to this configuration, the paper supply unit can support the paper guide member at a plurality of locations. As a result, the paper guide member does not tilt and can be stabilized at the paper guide position, and the paper conveyance performance can be further improved.
[0021]
Furthermore, in the present invention, since the paper transport unit is used for double-sided printing, there is no paper transport failure or paper jam at the time of double-sided printing by the image forming apparatus. It becomes possible to improve.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to FIGS. Since the basic configuration of this embodiment is the same as the conventional structure introduced in FIGS. 4 to 6, the same reference numerals are given to the components common to the conventional structure, and the description will be omitted.
[0023]
FIG. 1 is a schematic perspective view of the paper guide member and its periphery as viewed from below, FIG. 2 is a schematic cross-sectional view of the principal part showing the operation of the paper guide member when the paper supply unit is inserted into the printer body, and FIG. It is the schematic perspective view which looked at the guide member and the paper cassette from the upper part.
[0024]
A rotatable guide roller 26 is provided below the fulcrum F of the paper transport guide 22 and upstream of the paper transport direction. The guide rollers 26 are formed of an elastic material such as synthetic rubber or elastomer, and are provided on both the left and right sides with respect to the paper transport direction. Similar to the conventional structure, the paper guide member 22 can be lowered about the fulcrum F by holding the knob 23 by hand (see FIG. 6B).
[0025]
In FIG. 2, after the paper jam generated in the paper transport unit 21 is processed, it is necessary to insert the paper cassette 10 into the space of the main body 2 of the printer 1 (arrow in FIG. 2A). At this time, the paper guide member 22 is constantly urged to the paper guide position by the torsion spring 24, but the paper guide member 22 may be lowered by its own weight due to a decrease in the elastic force of the torsion spring 24 (FIG. 2 (a)). Subsequently, when the paper cassette 10 is inserted, the upper surface 11a of the side plate 11 which is a support surface provided in the paper cassette 10 comes into contact with the guide roller 26 (FIG. 2B). The side plates 11 are provided on both the left and right sides of the paper cassette 10 with respect to the paper transport direction, and the upper surfaces 11 a are in contact with the two guide rollers 26 of the paper transport unit 21. Then, the paper guide member 22 is supported from below so that the guide roller 26 rides on the side plate upper surface 11a of the paper cassette 10, and the paper guide member 22 is set at the correct paper guide position (FIG. 2C). FIG. 3).
[0026]
According to the above configuration, even when the resilience of the torsion spring 24 is reduced, the paper guide member 22 can be held at the paper guide position, and the paper transport unit 21 is configured correctly. There is no paper conveyance failure or paper jam. Thereby, the highly reliable printer 1 can be provided.
[0027]
Further, since the paper guide member 22 contacts the side plate upper surface 11a, which is the support surface of the paper cassette 10, via the guide roller 26, the paper guide member 22 is correctly set when the paper cassette 10 is inserted into the main body 2 of the printer 1. It can be held at the paper guide position, and the paper cassette 10 can be inserted smoothly. Further, no significant wear occurs at the portion where the paper guide member 22 and the paper cassette 10 come into contact with each other. Therefore, dust due to wear does not occur, and the paper P stored in the paper cassette 10 can be managed cleanly.
[0028]
Since the guide roller 26 is made of synthetic rubber or the like, even when the paper guide member 22 or the paper cassette 10 is wobbled due to aging due to the printer 1 being used for a long time, Insertion of the paper cassette 10 does not become tight. Therefore, the paper cassette 10 can be inserted smoothly indefinitely. Further, the friction generated between the side plate upper surface 11a of the paper cassette 10 and the guide roller 26 can be further reduced.
[0029]
Further, since the two guide rollers 26 of the paper guide member 22 are in contact with the side plate upper surfaces 11a provided on the left and right sides of the paper cassette 10 with respect to the paper transport direction, the paper cassette 10 has the paper guide members 22 at a plurality of locations. Can be supported. As a result, the paper guide member 22 does not tilt to the left or right, and can be stabilized at the paper guide position, and the paper transport performance can be further improved.
[0030]
Further, since the paper transport unit 21 is used for double-sided printing, it is possible to improve reliability without causing paper transport failure or paper jam during double-sided printing by the printer 1. It becomes possible.
[0031]
The insertion of the paper cassette 10 can be made tight even if a synthetic rubber sheet or foamed sponge sheet is provided on the surface of the upper surface 11a of the side plate or the guide roller 26 is attached to the paper guide member 22 via a coil spring or a leaf spring. Can be prevented.
[0032]
Although the embodiment of the present invention has been described above, various modifications can be made without departing from the spirit of the present invention.
[0033]
【The invention's effect】
According to the above configuration of the present invention, it is possible to hold the paper guide member at the paper guide position even if the spring force of the spring is reduced. Therefore, since the paper transport unit is configured correctly, paper transport failure and paper jam do not occur. Thereby, a highly reliable image forming apparatus can be provided.
[0034]
Further, the paper guide member contacts the support surface of the paper supply unit via the rolling member, so that the paper guide member can be held at the correct paper guide position when the paper supply unit is inserted into the image forming apparatus main body. In addition, the paper supply unit can be inserted smoothly.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a paper guide member and its periphery of a printer according to an embodiment of the present invention as viewed from below. FIG. 2 is a schematic cross-sectional view of a principal part showing the operation of the paper guide member shown in FIG. 3 is a schematic perspective view of the paper guide member and the paper cassette shown in FIG. 1 as viewed from above. FIG. 4 is a schematic vertical sectional view showing a schematic structure of a conventional printer. FIG. 5 shows a conventional paper guide member and its periphery. FIG. 6 is a schematic vertical sectional view showing a paper guide position and a jam processing position of a conventional paper guide member.
DESCRIPTION OF SYMBOLS 1 Printer 2 Main body 10 Paper cassette 11 Side board 11a Side board upper surface 20 Duplex printing part 21 Paper conveyance part 22 Paper guide member 23 Knob 24 Torsion spring 26 Guide roller

Claims (6)

In an image forming apparatus including a paper supply unit that can be pulled out from a main body in a horizontal direction and a paper transport unit disposed above the paper supply unit.
A paper guide member that can be lowered into the space after the paper supply unit is pulled out to perform paper jam processing is provided at the lowermost part of the paper transport unit. The paper supply unit is provided with a support surface that contacts and supports the paper guide member from below when the paper supply unit is inserted into the main body. The image is in contact with the paper guide member on the downstream side in the insertion direction of the paper supply unit with respect to a fulcrum shaft of the paper guide member provided in a direction orthogonal to the transport direction and the attachment / detachment direction of the paper supply unit. Forming equipment.   2. The image forming apparatus according to claim 1, wherein the paper guide member is in contact with a support surface of the paper supply unit via a rolling member.   3. The image forming apparatus according to claim 2, wherein the rolling member is supported by the paper guide member via an elastic member.   3. The image forming apparatus according to claim 2, wherein at least one of a support surface of the paper supply unit and a contact surface of the rolling member with the support surface is configured by an elastic member.   5. The image forming apparatus according to claim 1, wherein the sheet guide member is in contact with a plurality of support surfaces of the sheet supply unit.   6. The image forming apparatus according to claim 1, wherein the paper transport unit is used for double-sided printing.

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