JP3486290B2 - Double-sided device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided device used in an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, there are various types of double-sided devices such as copying machines and printers. As a typical format, for example, as described in JP-A-63-185747 and JP-A-63-187573, the recording paper after image formation is placed in a cassette case with the printing surface facing up. There is a type in which the recording paper is stored in the cassette case, switched back from the cassette case, inverted so that the printing surface faces downward, and re-fed to the image forming unit.

Further, as described in Japanese Patent Application Laid-Open No. 62-8957, a recording sheet discharged with a printing surface facing upward after image formation is reversed so that the printing surface faces downward. Fold it back, store it in the tray by turning it over so that the printing surface faces up, and flip the recording paper pulled out from this tray so that the printing surface faces down and re-feed it to the image forming unit. There is a format to do. The double-sided device of this type is generally disposed below the image forming unit and housed in the main body of the image forming device. However, since the recording paper is reversed in the S-shaped path, it is easy to curl and jam processing is troublesome. Therefore, a structure as shown in FIGS. 5 and 6 has been proposed.

Now, the double-sided device 1 shown in FIGS. 5 and 6 will be described. The double-sided device 1 is mainly composed of a tray 2 which is detachably attached to the main body of the image forming apparatus and is arranged substantially directly below an image forming unit (not shown). This tray 2
Is a flat box shape with an upper surface opened so that recording paper can be temporarily stored on the bottom surface. At one end (right end in the figure) of the tray 2 in the longitudinal direction, a re-feeding port 3 communicating with a paper feeding path (not shown) of the image forming unit is formed, and the vicinity of the re-feeding port 3 is formed. A reversing roller 4 driven by a motor (not shown) capable of rotating in the normal and reverse directions is rotatably supported by the.

A recording paper conveying section 6 is provided near the opening surface 5 of the tray 2. This recording paper transport unit 6
Guide plates 7 and 8 connected at a predetermined interval, a plurality of paper pressing members 10 and 11 rotatably supported by a lower guide plate 8 by pins 9 and an upper guide plate 7. And a pinch roller 12 which is axially supported. These pinch rollers 12 are pressed against the drive roller 13 or the reversing roller 4 provided on the tray 2 to rotate. Guide plates 7, 8
One end on the side of the re-feeding port 3 is opened toward the outer circumference of the reversing roller 4, and a receiving port 14 for receiving the recording paper discharged from the image forming portion is formed on the other end. The recording paper transport unit 6 is supported by a fulcrum portion 15 arranged near the reversing roller 4 so as to be vertically rotatable.

Further, the tray 2 is rotated about a rotatable driven roller 16 which comes into contact with the reversing roller 4, a recording paper placing plate 18 which is supported by a support shaft 17 so as to be up and down, and a support shaft 19. A pressure lever 20 that pushes up the recording paper plate 18 toward the reversing roller 4, a side fence 21 and an end fence 22 that regulate the position of the recording paper in the tray 2, and the like are provided.

In the state shown in FIG. 5, when the double-sided printing mode is set, the recording sheet on which an image has been formed is guided from the receiving port 14 to the guide plates 7 and 8, and is conveyed to the conveying roller 13 and the pinch roller 12. Are conveyed by the reversing roller 4 and are reversed by the reversing roller 4 driven in the clockwise direction to proceed along the bottom surface of the tray 2. In this case, the recording paper advances so as to pass under the paper pressing members 10 and 11, and the curl habit is corrected by the paper pressing members 10 and 11. When re-feeding, the rotation direction of the reversing roller 4 is switched to the counterclockwise direction, and the pressure lever 2
0 presses the recording paper mounting plate 18 to
The upper recording sheet is brought into contact with the reversing roller 4. This allows
The recording paper in the tray 2 is fed from the re-feeding port 3 toward the image forming unit by the reversing roller 4.

[0008]

As described above, in the double-sided device 1 for reversing the recording paper with the S-shaped path, when a jam occurs, the tray 2 is pulled out from the main body of the image forming apparatus, and further, In order to facilitate the jam processing, the recording paper transport unit 6 is rotated upward about the fulcrum portion 15. As a result, the upper space of the tray 2 and the periphery of the reversing roller 4 are widely opened. However, when the recording paper transport unit 6 is opened, the paper pressing member 10 located on the free end side of the recording paper transport unit 6 moves above the opening surface 5 of the tray 2, so that the fulcrum 15 is centered after the jam processing. When returning the recording paper transport unit 6 opened to the original position, the paper pressing member 10 may ride on the end of the opening surface 5 of the tray 2 as shown in FIG. If it is used without knowing this state, the guide plates 7 and 8 will not be properly set and the position of the receiving port 14 will change, so that a jam will easily occur at the receiving port 14.
The position of the end portion on the side opposite to the receiving port 14 is also slightly displaced, but this may also cause a jam in the vicinity of the reversing roller 4. Further, in the state shown in FIG. 6, since the recording paper transport unit 6 projects from the opening surface 5 of the tray 2, when the tray 2 is set in the main body of the image forming apparatus, the recording paper transport unit is attached to the main body or internal parts. Part of 6 may interfere and be damaged.

[0009]

The invention according to claim 1 is
A tray having an upper surface opening having a re-feeding port formed at the leading end, which communicates with a sheet feeding path of the image forming unit, a reversing roller which is provided in the vicinity of the re-feeding port, and which is rotatable in forward and reverse directions, and the image forming unit. A recording paper conveying section for guiding the recording paper discharged from the outer periphery of the reversing roller, a fulcrum section for supporting the recording paper conveying section in a vertically rotatable manner with the vicinity of the reversing roller as a fulcrum, and this fulcrum section. On the opposite side, a paper pressing member rotatably supported in the vicinity of the end of the recording paper transport unit, the free end of which faces the bottom surface of the tray, and the recording paper transport unit above the fulcrum. And a biasing member that biases the paper pressing member toward the bottom surface of the tray so that the free end of the paper pressing member does not exceed the opening surface of the tray when rotated. Therefore, the recording sheet discharged from the image forming section is conveyed by the recording sheet conveying section and is conveyed into the tray by the reversing roller, and when the reversing roller is driven in the reverse direction, the recording sheet is ejected from the re-feeding port by the conveying roller. It is fed. When jamming, etc., the recording paper transport unit is rotated upward about the fulcrum,
The paper pressing member is biased by the biasing member and is not positioned above the opening surface of the tray.

According to a second aspect of the present invention, in the first aspect of the present invention, the urging force of the urging member causes the paper pressing member to move the tray to the tray in a normal use state in which the recording paper conveying unit is set inside the tray. It is a value sufficient to press against the bottom of
It is set to a value that does not prevent the recording paper from entering between the bottom surface of the tray and the paper pressing member. Therefore, the recording paper conveyed by the reversing roller advances to a predetermined position on the tray without being obstructed by the paper pressing member,
The paper pressing member effectively prevents the upward floating.

According to a third aspect of the present invention, in the first aspect of the invention, the urging member has a paper pressing member on the bottom surface of the tray in a normal use state in which the recording paper conveying unit is set inside the tray. The amount of bending in the pressurizing direction is limited so as not to press-contact. Therefore, the recording paper conveyed by the reversing roller advances to a predetermined position on the tray without being obstructed by the paper pressing member, and the upward lifting is restricted by the paper pressing member.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention is shown in FIG.
And it demonstrates based on FIG. In the present and subsequent embodiments, the same parts as those described with reference to FIGS. 5 and 6 are designated by the same reference numerals, and description thereof will be omitted. In the present embodiment, the paper pressing member 10 supported on the free end side of the recording paper conveying unit 6 is urged downward by the urging member 23. The biasing member 23 is a twisted coil spring fitted to the pin 9 and having a hook 24 that abuts the lower surface of the guide plate 8 and a hook 25 that presses the paper pressing member 10 downward. is there. The other paper pressing member 11 is simply urged downward by its own weight.

Here, the upward rotation range of the recording paper conveying section 6 around the fulcrum section 15 is limited to a certain range by a stopper (not shown). Then, as shown in FIG. 2, when the recording paper transport unit 6 is rotated to the upper limit position, the angle formed by the guide plate 8 and the paper pressing member 10 is α.
Stipulated in. The angle α is set within a range in which the free end portion of the paper pressing member 10 does not extend above the opening surface 5 of the tray 2. Further, as shown in FIG. 1, in a state where the recording paper transporting portion 6 is rotated downward around the fulcrum portion 15, the paper pressing members 10 and 11 rotate by receiving resistance from the bottom surface of the tray 2. That is, the paper pressing member 10 is the tray 2
By the resistance of (1), it rotates clockwise against the urging force of the urging member 23. At this time, the angle β formed by the guide plate 8 and the paper pressing member 10 is smaller than α. It should be noted that the tray 2 is provided with a clamp mechanism (not shown) that supports the recording paper transport unit 6 at a fixed position.

In such a structure, when the double-sided printing mode is set, the recording sheet on which the image is formed is guided from the receiving port 14 between the guide plates 7 and 8 and is conveyed by the conveying roller 1.
3 is conveyed by the pinch roller 12 and is reversed by the reversing roller 4 which is driven in the clockwise direction and advances along the bottom surface of the tray 2. In this case, the recording paper is the paper pressing member 1.
The paper pressing member 1 is advanced so as to pass under 0 and 11.
The curl habit is corrected by 0 and 11. At the time of re-feeding, the rotation direction of the reversing roller 4 is switched to the counterclockwise direction,
The pressure lever 20 presses the recording paper placing plate 18 to bring the recording paper on the recording paper placing plate 18 into contact with the reversing roller 4.
As a result, the recording paper in the tray 2 is fed from the re-feeding port 3 toward the image forming unit by the reversing roller 4.

At the time of jam processing or the like, the tray 2 is pulled out from the main body of the image forming apparatus, and the recording paper conveying section 6 is rotated upward about the fulcrum section 15 as shown in FIG.
The paper pressing member 10 is biased by the biasing member 23 and is not positioned above the opening surface 5 of the tray 2. Therefore,
Unlike the conventional case, the paper pressing member 10 does not ride on the end of the opening surface 5 of the tray 2. Thereby, when the tray 2 is inserted into the main body of the image forming apparatus, it is possible to avoid damage accidents due to contact between the components in the main body and the recording paper transport unit 6.

Further, since the paper pressing member 10 does not ride on the end of the opening surface 5 of the tray 2, the recording paper conveying section 6 is provided.
Can be set at a fixed position in the tray 2. As a result, it is possible to prevent the occurrence of a jam due to a setting failure.

Further, the urging force of the urging member 23 is a value sufficient to press the paper pressing member 10 against the bottom surface of the tray 2 in a normal use state in which the recording paper conveying section 6 is set inside the tray 2. The recording paper conveyed by the reversing roller 4 is prevented from advancing by the paper pressing member 10 by setting a value that does not prevent the recording paper from entering between the bottom surface of the tray 2 and the paper pressing member 10. Therefore, it is possible to effectively move the tray 2 to a predetermined position and prevent it from floating upward by the paper pressing member 10.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 and 4. The urging member 23 in the present embodiment applies the paper pressing member 10 to the range where the bottom surface of the tray 2 is not brought into pressure contact with it in a normal use state (FIG. 3) in which the recording paper conveying unit 6 is set inside the tray 2. The amount of bending in the pressure direction is limited. That is, as shown in FIG. 3, in a normal use state in which the recording paper conveyance unit 6 is set at a fixed position on the tray 2, the paper pressing member 10 and the guide plate 8 in a state where the free end contacts the bottom surface of the tray 2. The angle β is an angle α ′, and the angle that the paper pressing member 10 is rotated only by the urging force of the urging member 23 (the angle between the paper pressing member 10 and the guide plate 8) is α ′. Smaller than. The difference Δα is the rotation range of the paper pressing member 10 due to its own weight. This difference Δ
α is a small range. However, as shown in FIG. 4, the angle α ′ is a range in which the paper pressing member 10 is not rotated more than the opening surface 5 of the tray 2 when the recording paper transport unit 6 is opened upward.

In such a structure, as shown in FIG. 3, the paper pressing member 10 is urged by the urging member 2 in a normal use state.
Although it is urged downward by the urging force of 3, the range of rotation by the urging force is α ′ when converted to the angle formed with the guide plate 8, and the range beyond that is rotated by its own weight to rotate the tray 2. Since the recording paper comes into contact with the bottom surface, the recording paper can be advanced to a predetermined position of the tray 2 without hindering the progress thereof by the paper pressing member 10, and the paper pressing member 10 can restrict the upward floating.

As a structure for limiting the amount of bending of the biasing member 23 in the pressing direction, for example, there is a structure in which a stopper (not shown) that abuts the hook 25 of the biasing member 23 is provided on the guide plate 8. To be

[0021]

According to the first aspect of the invention, the reversing roller is provided in the vicinity of the re-feeding port of the tray, and the recording paper conveying section for guiding the recording paper discharged from the image forming section to the outer periphery of the reversing roller is provided. A fulcrum portion arranged near the reversing roller is provided so as to be vertically rotatable, and a paper pressing member having a free end facing the bottom surface of the tray is provided in the vicinity of the end of the recording paper conveying unit on the opposite side of the fulcrum. The paper pressing member is rotatably provided so that the free end portion of the paper pressing member does not exceed the opening surface of the tray when the recording paper conveying unit is rotated upward about the fulcrum. Since the biasing member biases the tray toward the bottom side, the jamming process or the like causes the recording paper transport unit to rotate upward about the fulcrum, but the paper pressing member moves to the end of the opening surface of the tray. It is possible to prevent riding. Accordingly, when the tray is inserted into the main body of the image forming apparatus, it is possible to avoid damage accidents due to contact between the components inside the main body and the recording paper transport unit. Further, since the paper pressing member does not ride on the end portion of the opening surface of the tray, the recording paper transport unit can be set at a fixed position in the tray. As a result, it is possible to prevent the occurrence of a jam due to a setting failure.

According to a second aspect of the present invention, in the first aspect of the present invention, the urging force of the urging member causes the paper pressing member to move the paper pressing member to the tray in a normal use state in which the recording paper conveying unit is set inside the tray. It is a value sufficient to press against the bottom of
Since it is set to a value that does not prevent the recording paper from entering between the bottom surface of the tray and the paper pressing member, the paper pressing member does not hinder the progress of the recording paper conveyed by the reversing roller. The tray can be advanced to a predetermined position, and the paper pressing member can effectively prevent upward floating.

According to a third aspect of the present invention, in the first aspect of the present invention, the urging member is such that the paper pressing member is provided on the bottom surface of the tray in a normal use state in which the recording paper conveying unit is set inside the tray. Since the amount of bending in the pressing direction is limited so as not to press contact, the recording paper conveyed by the reversing roller is advanced to a predetermined position on the tray without being obstructed by the paper pressing member, and the paper pressing member is used. It is possible to limit the upward floating.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a normal use state in a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional side view showing a state in which a recording paper conveyance unit is opened.

FIG. 3 is a vertical cross-sectional side view showing a normal use state in a second embodiment of the present invention.

FIG. 4 is a vertical cross-sectional side view showing a state in which a recording paper conveyance unit is opened.

FIG. 5 is a vertical sectional side view showing a normal use state in a conventional technique.

FIG. 6 is a vertical cross-sectional side view showing a state in which a recording paper conveyance unit is opened.

[Explanation of symbols]

2 trays 3 Refeed port 4 Reverse roller 5 Opening surface 6 Recording paper transport 10 Paper holding member 15 fulcrum 23 Biasing member

Claims (3)

(57) [Claims] 1. A tray with an upper surface opening having a re-feeding port formed at the front end that communicates with a sheet feeding path of an image forming section, and a reversing roller that is provided in the vicinity of the re-feeding port and is rotatable in the forward and reverse directions. A recording paper conveying unit that guides the recording paper discharged from the image forming unit to the outer periphery of the reversing roller; and a fulcrum portion that supports the recording paper conveying unit in a vertically rotatable manner with the vicinity of the reversing roller as a fulcrum. , A paper pressing member which is rotatably supported in the vicinity of the end portion of the recording paper transporting portion on the side opposite to the fulcrum portion, and has a free end facing the bottom surface of the tray, and the recording centering around the fulcrum portion. A biasing member that biases the paper pressing member toward the bottom surface of the tray so that the free end of the paper pressing member does not exceed the opening surface of the tray when the paper transport unit is rotated upward. A double-sided device comprising: 2. The urging force of the urging member is a value sufficient to press the paper pressing member against the bottom surface of the tray in a normal use state in which the recording paper conveyance unit is set inside the tray, 2. The double-sided device according to claim 1, wherein the double-sided device is set to a value that does not prevent the recording paper from entering between the bottom surface of the paper and the paper pressing member. 3. The urging member has a limited amount of bending in the pressing direction so that the paper pressing member does not come into pressure contact with the bottom surface of the tray in a normal use state in which the recording paper transport unit is set inside the tray. The double-sided device according to claim 1, wherein the double-sided device is provided.