JPH0544354Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is an automatic document feeder (reversible automatic document feeder) that is installed in an image forming apparatus such as a copying machine or a facsimile machine and is capable of reversing a document. RADF).

(Prior art) In recent years, image forming apparatuses equipped with automatic document feeders have become more and more popular. Document feeders (RADF) are now available that have a function that allows image formation to be performed with a single touch.

By the way, such a RADF is equipped with a document reversing mechanism that reverses the transported document and sends it back, but the document path has to be undone three times along the way.
The conveyor roller has a multi-layered shape that rotates, and when a document jam occurs in the internal passage, it is extremely difficult to remove the document that has been jammed by the conveyance roller from within the passage. Moreover, in the case of transfer paper jams, even if the transfer paper is damaged, you can copy it again, but originals cannot be damaged, so extreme care must be taken when disposing of jams. No. Therefore, there is a need for a structure that can easily take out the jam paper without damaging it as much as possible.

Conventionally, in order to meet such demands, for example, in Japanese Utility Model Application Publication No. 60-167032, the upper guide plate forming the document reversing path was configured to be openable and closable.
A pinch roller that comes into pressure contact with the roller attached to the main body side is attached to this upper guide plate, and by opening the upper guide plate, the document path is opened upward and the pressure contact between the pinch roller and the conveyance roller is released. What has been done is disclosed.

However, in this structure, the pinch roller is supported by the upper guide plate that is operated to open and close, and the pinch roller and the conveyance roller come into contact with and separate from each other, so compared to a structure in which the pinch roller and the conveyance roller are always in pressure contact, both There was a problem in that the relative positions of the two and the pressure force tended to vary, making it difficult to set the dimensions.

(Purpose of the invention) In view of the above-mentioned circumstances, the present invention is designed to facilitate manufacturing, stabilize the relative position and pressing force between the transport roller and the pinch roller, and easily remove jammed originals from the original path without damaging them. An object of the present invention is to provide a document reversing mechanism for an automatic document feeder that is capable of reversing documents.

(Structure of the invention) The present invention has a document reversing path for reversing a document, a guide plate forming a part of the document reversing path, a transport roller for transporting the document in the document reversing path, and a transport roller for transporting the document within the document reversing path. In the automatic document feeder, the guide plate is configured to be rotatable so as to open and close a part of the document reversing path, and the guide plate is configured to rotate in conjunction with the rotation of the guide plate. The apparatus is provided with an interlocking mechanism that rotates the conveyance roller only in the direction in which the document is fed into the path formed by the guide plate.

In such a configuration, if a document jams in the path formed by the guide plate, repeating the rotating operation of the guide plate will cause the transport roller to feed the document to the path. It rotates intermittently only in the ejecting direction, and as a result, the document that has been bitten by the conveyance roller comes off from the roller, so that the jammed document can be easily taken out from the opened passage.

(Example) An embodiment of the present invention will be described based on the drawings.

FIG. 1 schematically shows an automatic document feeder. In the figure, 1 is a document tray, and 2 is a roller disposed above the document tray. Also, on the downstream side, there are two pairs of feed rollers 3 and 4.
is installed. A conveyor belt 6 is provided above the contact glass 5 of the image forming apparatus, and a document reversing mechanism 7 for reversing the document is provided downstream thereof.

The document reversing mechanism 7 includes guide members 9, 10 and guide plates 11, 12, 13 fixed to the main body side.
and further includes a rotation guide plate (guide plate) attached to the main body so as to be rotatable about the shaft 14.
15, a cover 17 similarly rotatably mounted around a shaft 16, and a switching guide plate 18. The passage 19 is formed by the guide plates 11 and 12, and the passage 20 is formed by the rib 17a of the cover 17 in the closed state and the upper surface of the rotation guide plate 15.
The rib 17b of the cover 17 and the guide member 10
The passage 21 is opened by the switching guide plate 18, the passage 22 is opened by the switching guide plate 18, and the passage 2 is opened by the guide members 9 and 10.
3, a passage 24 is formed by the rib 15a of the rotation guide plate 15 and the guide member 9, and a passage 25 is formed by the guide plate 13 and the rib 9a of the guide member 9. The passages 20 and 21 are opened and closed by the rotation guide plate 15, and the passage 24 is opened and closed by the rotation of the rotation guide plate 15. And the above passages 19-25
The entire document reversing path is constituted by.

On the upstream side of the passage 19, a conveyance roller 26 and a roller 30 on the image forming apparatus main body side are provided, and on the upstream side of the passage 20, a conveyance roller 27 and a roller 31 are placed on the passage 20.
1, there are a conveyance roller 28 and a roller 32 on the upstream side.
However, there is a return conveyance roller 2 on the upstream side of the passage 22.
9 and rollers 33, the conveyance roller 28 and rollers 34 on the upstream side of the passage 24, the conveyance roller 27 and rollers 35 on the upstream side of the passage 25,
In the passage 25, the conveying rollers 26 and rollers 36 are in pressure contact with each other, and the conveying rollers 26 to 29 are rotated and the rollers 36 are driven accordingly.
By the synchronous rotation of 0 to 36, the original is moved to the path 19,
The objects are conveyed sequentially through passages 20, 21, 22, 23, 24, and 25. In addition, these conveyance rollers 26 to 2
9 and rollers 30 to 36 are all pivotally supported on the main body side.

The switching guide plate 18 is configured to be switched between a position shown by a solid line and a position shown by a chain double-dashed line in FIG. , a document ejection path is formed together with the cover 17 at the position indicated by the two-dot chain line. Further, a discharge roller 37 and a roller 38 are provided on the downstream side of the document discharge path, and a discharge tray 39 is arranged on the downstream side thereof.

Furthermore, in this device, as shown in FIGS. 2 to 4, a gear 41 is fixed to a portion of the rotating shaft 40 of the conveying roller 28 that protrudes from the side wall W (FIG. 4) of the device main body. , a gear 42 that meshes with this is attached to the shaft 14, which is the center of rotation of the rotation guide plate 15.

A one-way clutch 43 is press-fitted between the shaft 14 and the gear 42, as shown in FIG. This one-way clutch 43 is configured to transmit only the rotation of the shaft 14 in the counterclockwise direction to the gear 42 in FIG. ing. Note that this one-way clutch 43 may be a commonly used one, such as a spring type or a ball type.

Therefore, when opening and closing the rotating guide plate 15 as shown in FIG. is transmitted to the conveying roller 28 via the one-way clutch 43, gears 42, 41, and rotating shaft 40, so that the conveying roller 28 rotates clockwise in the figure. That is, the gears 41, 42 and the one-way clutch 43 constitute an interlocking mechanism 44 that rotates the conveying roller 28 only in the direction of conveying the original toward the passage 24 in conjunction with the opening and closing of the rotation guide plate 15. has been done. In addition, in FIG. 2 and FIG. 3, 45 is a support plate that supports the rotation guide plate 15 in the closed state.

First, the operation of such an apparatus when performing one-sided copying of a document will be described.

First, the rotation guide plate 15 and cover 17 are closed. Then, when the copy start button is turned on with a document set in the document tray 1, the roller 2 comes into contact with the top surface of the document and sends out the top document. This document is sent to a conveyor belt 6 by feed rollers 3 and 4. The conveyance belt 6 stops after conveying the document to a predetermined position on the contact glass 5, and in this state, an image is formed on the document.

After the image is formed, the conveyor belt 6 operates again, and the document is conveyed into the document reversing mechanism 7. At this time, the switching guide plate 18 has been switched to the position indicated by the two-dot chain line in FIG.
8 to the discharge tray 39. below,
By repeating the same operation, the originals on the original tray 1 are sequentially fed and one-sided copies are performed.

Next, the operation when performing double-sided copying of a document will be explained. All originals are set on the original tray 1 with the front side facing downward. When the copy button is turned on from this state, the document is conveyed to the conveyor belt 6 by the rollers 2 and feed rollers 3 and 4 in the same way as above, but the conveyor belt 6 does not stop and transfers the document into the document reversing mechanism 7. transport. At this time, the switching guide plate 18 has been switched to the position shown by the solid line in FIG. 1, and the original is conveyed back through the passages 19 to 25 to the conveyor belt 6, which is already in a stopped state. By passing through the document reversing path in this manner, the document is returned onto the contact glass 5 in an inverted state, and an image is first formed on the back surface of the document. Note that while the document is being reversed, the transport roller 28 and the gear 41 are driven to rotate clockwise in FIG. 2, and in conjunction with this, the gear 42 is rotated counterclockwise in the diagram. One-way clutch 43 configured as follows.
does not transmit this rotation to the shaft 14.

When the image is formed on the back side, the conveyor belt 6 is operated again and the document is sent into the document reversing mechanism 7. Then, in the same manner as described above, the original passes through the original reversing path, is reversed, and is sent onto the contact glass 5, where an image is formed on the surface thereof.
When image formation on this surface is completed, the conveyor belt 6 operates again, but at this time the switching guide plate 1
8 is switched to the position indicated by the two-dot chain line in FIG. By repeating the same operation, double-sided copying of all documents is performed.

During double-sided copying of such a document, if a document jam occurs in the path 24 with the document being jammed by the conveyance rollers 28 and rollers 34 and the conveyance rollers 27 and rollers 35, first open the cover 17. , then open the rotation guide plate 15 to open the passage 2.
4 opens upward. Furthermore, when this rotation guide plate 15 is repeatedly rotated as shown in FIG. 2 and gradually feeds the jammed document D as shown in FIG. The end becomes free.

That is, according to this structure, even if a document jam occurs in the passage 24, which is a part of the document reversing passage having a complicated shape, the cover 17 and the rotation guide plate 15 are opened, and the guide plate 15 is not opened or closed. By simply repeating the operation, the document D can be removed from the conveying rollers 28 and the rollers 34 that are in pressure contact with each other, and thus the jammed document D can be easily taken out without damaging it. Moreover, since the conveyance roller 28 and the roller 34 are always in pressure contact,
The relative positions of the two and the pressure contact force can be easily set, and stabilization can be achieved. In addition,
If a document jam occurs in the passage 20 or 21, the jammed document can be easily removed by simply opening the cover 17.

The present invention is not limited to the structure described above; for example, in the above embodiment, a one-way clutch 43 is provided between the shaft 14 and the gear 42; The above effect can also be obtained by a structure in which the clutch 43 is provided.

(Effects of the invention) As described above, according to the invention, by rotating the guide plate that forms the document reversing passage, the passage can be opened and closed freely, and in conjunction with the rotation of this guide plate, the document reversing passage is Since the rollers are designed to rotate only in the direction in which the original is fed into the path formed by the guide plate, even if a document jam occurs in the path formed by the guide plate, the guide plate can be rotated. The effect is that the document can be easily taken out without damaging the document by simply opening it and repeating the opening and closing operations. Furthermore, since the rollers and the conveyance roller are constructed to be in constant pressure contact with each other, the relative positions thereof and the pressure contact force can be easily set and stabilized.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an automatic document feeder according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing the main parts of the automatic document feeder with the passage formed by the guide plate closed, and FIG. Figure 3 is a sectional view showing the main parts of the automatic document feeder when the passage is opened and closed, Figure 4 is a plan view of the interlocking mechanism in the automatic document feeder, and Figure 5 is a diagram of the gears in the interlocking mechanism. and a cross-sectional view of the one-way clutch. 15...Rotation guide plate (guide plate), 24...
Passage formed by rotation guide plate, 28... Conveyance roller, 34... Roller, 44... Interlocking mechanism, D
...Manuscript.

Claims (1)

[Scope of utility model registration request] It has an original reversing path for reversing the original, a guide plate forming a part of this original reversing path, a transport roller for transporting the original within the original reversing path, and a roller that is in pressure contact with the transport roller and rotates synchronously. In the automatic document feeder, the guide plate is configured to be rotatable so as to open and close a part of the document reversing path, and the conveyance roller is formed by a guide plate in conjunction with the rotation of the guide plate. An automatic document feeder characterized in that it is equipped with an interlocking mechanism that rotates the document only in the direction in which the document is fed into the path.