JP3739567B2 - Automatic document feeder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic document feeder mounted on a copying machine or the like, and more particularly to a circulation type automatic document feeder.
[0002]
[Prior art]
In a general automatic document feeder, the documents stacked on the document table are fed and separated one by one, conveyed onto the contact glass, and after a desired number of copies are copied at the reading position on the contact glass, Is discharged to the paper discharge tray. For this reason, only one pass is required regardless of the number of copies, and the durability of the apparatus is about 600,000. On the other hand, in the circulation type automatic document feeder that circulates the fed and separated documents according to the number of copies, it is necessary to increase the durability of the device, and about 10 million sheets, which is about 17 times that of a general automatic document feeder. It is. In such an apparatus, the side fence for positioning in the document width direction is a part that is always touched by the user. Therefore, in consideration of electric shock caused by charging and discharging, the side fence may be made of resin from the viewpoint of safety. Many.
[0003]
Examples of devices of this type include Japanese Patent Laid-Open Nos. 4-169437 and 3-166139.
[0004]
[Problems to be solved by the invention]
In the above prior art, the positioning surface in the document width direction of the side fence is severely worn, and in reality, the positioning accuracy in the document width direction deteriorates at about 1 million sheets, and problems such as document skew occur. is there.
An object of the present invention is to provide an automatic document feeder that improves such problems, has excellent durability, and can realize stable conveyance quality. More specifically, the wear of the original positioning surface due to the original passing can be reduced, the position of the original on the original table can be prevented from being shifted, and the occurrence of skew or the like can be suppressed. An object of the present invention is to make it possible for a document that has been returned to fall smoothly on the document table. In addition to the above, another object of the present invention is to provide an automatic document feeder that is easy to assemble and low in cost and is suitable for downsizing.
[0006]
In order to achieve the above object, an automatic document feeder according to the present invention is mounted on a copying machine, feeds and separates documents stacked on a document table one by one, and circulates them according to the number of copies. An apparatus for changing a distance between at least one pair of side fences for positioning a document stacked on the document table in the document width direction and the pair of side fences according to the width direction size of the document. A part of the original positioning surface of the pair of side fences is formed of a metal wear-resistant member, and the metal wear-resistant member is formed of the side fence. It is characterized by being integrated with the moving means.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of an automatic document feeder showing an embodiment of the present invention, FIG. 2 is a perspective view showing a configuration of a side fence in the automatic document feeder of FIG. 1, and FIG. Sectional drawing ( FIG.3 (b) is an enlarged view of Fig.3 (a) ), FIG.4 is a figure which shows the assembly method of the side fence of FIG. The automatic document feeder of this embodiment is mounted on a copying machine main body (not shown), and a document 4 stacked on the document table 3 in the document setting unit 23 is fed to a paper feed belt 6 and a pull-out roller 7. The sheet is fed and separated one by one, etc., and circulated according to the number of copies. Further, as shown in FIG. 2, at least one pair of side fences 1 (side fences 1a and 1b) for positioning the originals 4 stacked on the original table 3 in the original width direction are provided in the original setting unit 23. And an end fence 2 for positioning the trailing edge of the document. As shown in FIGS. 3 (a) and 4, the side fence 1a has a part of the original positioning surface of the side fence 1 (the metal wall 39 formed on the rack 36 has a rectangular window 46 of the side fence 1a. (Exposed portion) is formed from a metal wear-resistant member. In addition, the other part of the side fence 1a is comprised with the member which consists of resin etc. The rack 36 (= side fence moving means) slides and moves a pair of side fences 1a and 1b via a gear 36a as shown in FIG. As shown in FIGS. 3 and 4, the wall 39 is formed integrally with the rack 36. When assembling these parts 36 and 39, as shown in FIG. 4, the wall 39 is inserted into the through-hole 40 having a square cross section provided in the side fence 1a, the rack 36 is set in the side fence 1a, and the screws 37 are used. Fix it. According to this embodiment, since the rack 36 and the side fence 1a are integrated, it is easy to assemble, is low in cost, and contributes to downsizing of the apparatus. In addition, a rectangular window 46 is provided on the surface 38 for determining the position of the side fence 1a in the document width direction. As shown in FIG. 46 is recessed by a depth x (specifically, 1 mm or less). That is, there is a step of 1 mm or less between the original positioning surface formed by the wall 39 and the surface 38. In addition to this embodiment, a rectangular separate part having a size corresponding to the window 46 made of a metal wear-resistant member is pasted without providing the window 46 on the surface 38 and without being integrated with the rack 36. Or it may be attached. In this case, when the original 4 returned to the original table 3 after circulating through the conveying path in the apparatus falls, it is formed thinner so as not to be caught by the separate parts. In the present embodiment, the side fence 1a has been described, but the side fence 1b paired with the side fence 1a is configured in the same manner.
[0009]
Further, as shown in FIG. 2, the paper feeding belt 6 in the document setting unit 23 is formed by a plurality of endless belts in parallel with the paper feeding direction. A suction hole (not shown) for sucking the lowermost document 4 is arranged. The suction hole is provided in the vacuum tank 25 below the paper feed belt 6 and is configured to be opened and closed by a valve (not shown) in the vacuum tank 25. The valve is opened and closed by turning on / off a solenoid (not shown). On the other hand, an air knife 5 is provided above the paper feed side end of the paper feed belt 6, and is compressed from the plurality of nozzles 24 of the air knife 5 to the paper feed side end of the loaded original 4 by an ADF blower motor (not shown). By blowing air, it is configured to prevent double feeding during document feeding and separate one by one.
[0010]
Further, as shown in FIG. 5, the SADF paper feed unit in the present embodiment performs positioning in the document width direction on the SADF document table 19 for setting a document so that the image surface faces upward. Side fence 45, SADF partition claw 30 driven by a solenoid (not shown), relay lever 34 that relays the operation of the SADF partition claw 30 and interlocks the SADF pressure roller 35, and a solenoid (not shown) The SADF switching claw 31 that is driven, the SADF roller 18 that is driven by a drive motor (not shown), and the document that is driven by a drive motor (not shown) and is set on the document table 3 in conjunction with the operation of the SADF partition claw 30. It is composed of a SADF pressure roller 35 that feeds pressure. The side fence 45 is smaller than the side fence 1 and is made of, for example, resin.
[0011]
The originals 4 separated one by one in the original setting unit 23 are conveyed onto the contact glass 9 through the respective conveying paths. The contact glass 9 together with a slit glass (not shown) is used in the copying machine. It is provided on the upper surface. Further, below the contact glass 9 and the slit glass, an exposure lamp, a first mirror, and the like (not shown) are provided. The exposure lamp and the first mirror move to the left and right in FIG. 1 when reading the document 4 on the contact glass 9, and stop below the slit glass when reading the document 4 on the slit glass. The exposure lamp irradiates the image surface of the original with light. After the exposure processing is completed in this way, the reflected light is imaged on a photosensitive drum (not shown) via a first mirror and an optical system (not shown), and the electrostatic formed on the photosensitive drum. It is configured so that toner or the like adheres to the latent image and is transferred to the recording paper. Alternatively, the reflected light is imaged on an image sensor (not shown) such as a CCD through the optical system, and recording paper is recorded on an image forming means (not shown) using a signal photoelectrically converted by the image sensor. It is configured to transfer an image to.
[0012]
Next, the operation of the automatic document feeder according to this embodiment will be described. First, the case of RDH single-sided original and single-sided copying modes will be described. In the present embodiment, the document 4 is set on the document table 3 of the document setting unit 23 so that the image surface faces upward. At this time, the end fence 2 and the side fence 1 (side fences 1a and 1b) arranged on the document table 3 are positioned in the document rear end and the width direction. According to the present embodiment, as described above, a part of the document positioning surface (wall 39) of the side fence 1 is formed of a metal wear-resistant member, so that the positioning is always stable with little wear during document positioning. It can be performed. Further, since only a part of the original positioning surface, not the entire side fence 1, is made of metal, the user does not receive an electric shock due to charging or discharging, and can be used safely. After the document 4 is set at a predetermined position in this way, the partition plate 15 built in the end fence 2 is rotationally driven by pressing a copy start key of a copying machine main body operation unit (not shown). Touch the top. At the same time, a fan motor (not shown) rotates, and compressed air is blown from the plurality of nozzles 24 provided at the lower part of the air knife 5 from the leading end of the stacked originals 4 so that the originals 4 are lifted. become. At this time, when a suction force is applied by turning on a valve (not shown) in the vacuum tank 25, only the lowermost document is adsorbed to the upper surface of the paper feed belt 6 through a plurality of holes, and the documents other than the lowest document. 4 maintains the raised state. In this state, when the paper feeding belt 6 is driven to rotate counterclockwise, only the lowermost document is pulled out.
[0013]
When the IN sensor 26 detects that the leading edge of the lowermost document has been nipped by the pull-out roller 7, the drive of the paper feeding belt 6 is stopped and the valve in the vacuum tank 25 is turned off to apply a suction force. The blocking prevents the next document from being conveyed. The document nipped by the pull-out roller 7 is turned in the direction of the contact glass 9 (direction A) by a sheet feeding deflection claw 8 driven by a solenoid (not shown) and contacted by the sheet feeding roller 10 and the conveying belt 11. It is conveyed onto the glass 9. The pull-out roller 7, the paper feed roller 10, the reversing roller 17 and the SADF roller 18, which will be described later, are driven at the same speed by the same drive motor (not shown). After the exposure on the contact glass 9, the document is conveyed by the conveyance belt 11 and the discharge roller pair 12, and the direction is changed to the RDH document table 3 direction (D direction) by the discharge deflection claw 13, and the discharge belt 14 Returned to the RDH document table 3. The job is divided by the partition plate 15 in the end fence 2. According to the present embodiment, as described above, a part of the document positioning surface (wall 39) of the side fence 1 is formed in a concave shape using the metal wear-resistant member. There is little wear on the original positioning surface, and stable positioning can always be performed . In addition, when a separate member having a size corresponding to the window 46, which is made of a metal wear-resistant member, is pasted or attached as the wall 39, the original 4 that has returned through circulation on the conveyance path is When falling on the document table 3, the corners of the other members may be touched and the alignment may be disturbed. However, according to the present embodiment, the center portion and the peripheral portion of the document positioning surface of the side fence 1 may be disturbed. Since there is a step having a depth of 1 mm or less between them, the alignment is not disturbed by touching the corner of the other member .
[0014]
Next, the case of the RDH double-sided original and double-sided copy mode will be described. As in the single-sided copying mode, the original conveyed by the pull-out roller 7 is turned in the reverse direction (direction B) by the paper feed deflection claw 8 and the reverse deflection claw 16 interlocked therewith, and is conveyed by the reverse roller 17 and the SADF roller 18. Further, it is conveyed in the direction of the reverse conveyance path 32 by the SADF deflection claw 31 shown in FIG. The SADF deflection claw 31 is driven by a solenoid (not shown). The SADF deflection claw 31 is switched at the same time as receiving a signal indicating the duplex copying mode from the copying machine main body operation unit, and does not perform the switching operation until one job divided by the partition plate 15 is completed. The SADF pressure roller 35 is driven by a solenoid (not shown) in conjunction with a later-described SADF partition claw 30, and this is also switched to a pressure state simultaneously with the operation of the SADF switching claw 31. Thereafter, when the reverse sensor 20 detects the passage of the trailing edge of the document, the drive motor rotates in the reverse direction and performs a switchback operation. At the same time, since the feeding deflection claw 8 and the reverse deflection claw 16 can be changed in direction, the switched-back document is changed in the direction of the contact glass 9 (C direction). It is conveyed in a state of being inverted. Then, after the exposure of the image surface (back surface) of the inverted document is completed, the document is returned to the RDH document table 3 as in the single-sided copy mode. At this time, since the first set state is reversed, the switchback operation is performed at the same time as the exposure of the back side of all the set originals is completed. Copied and returned to the RDH document table 3 in the first set state. According to the present embodiment, as described above, a part (wall 39) of the document positioning surface of the side fence 1 is formed in a concave shape by using the metal wear-resistant member. There is little wear on the document positioning surface, and stable positioning can be performed at all times. When the document 4 circulated and returned on the conveyance path falls on the document table 3, it touches the corner of the wall 39 to cause skew. It will never be.
[0015]
Next, the SADF mode will be described. The document 4 is set on the SADF document table 19 with the image surface facing upward and the leading end being abutted against the SADF partition claw 30. The SADF partition claw 30 is in a partitioned state in a default state, and the SADF pressure roller 35 interlocked with the operation of the SADF partition claw 30 via the relay lever 34 is in a non-pressurized state. The SADF partitioning claw 30 is opened by the copy start signal from the operation unit of the copying machine, the SADF pressure roller 35 is lowered to pressurize the document 4, and at the same time, a driving motor (not shown) is driven to 4 is conveyed by the SADF roller 18 and the reverse roller 17 in the same manner as the operation after the switchback in the reverse mode, and the direction is changed to the contact glass 9 direction (C direction) by the paper feed deflection claw 8 and the reverse deflection claw 16. Then, the paper is conveyed onto the contact glass 9 by the paper feed roller 10. Further, after the exposure is finished, the document 4 is conveyed by the conveying belt 11 and the discharge roller 12, changed in the direction toward the SADF discharge table 21 (E direction) by the discharge deflection claw 13, and the SADF discharge table by the discharge roller 22. 21 is discharged.
[0016]
In the present embodiment, the circulation type automatic document feeder has been described. However, the configuration of the side fences 1, 1 a, 1 b described above is naturally applicable to a non-circulation type automatic document feeder, and similarly. The durability of the original positioning surface can be improved and stable conveyance quality can be realized.
[0017]
【The invention's effect】
As described above, according to the present invention, the document positioning surface of the side fence that performs positioning in the document width direction on the document table of the automatic document feeder is formed by the wear-resistant member different from the other members. Can increase the durability. More specifically, since a part of the original positioning surface is formed of a metal wear-resistant member, the original positioning surface is excellent in durability and stable conveyance quality can be realized. In other words, since the wear of the original positioning surface due to the original passing is reduced, the original position on the original table is prevented from being displaced, and the occurrence of skew or the like can be suppressed, so that stable conveyance quality can be realized at all times. .
[0018]
Further, according to the present invention, a part of the original positioning surface is formed in a concave shape, so that the original that circulates back on the conveyance path returns to the wear-resistant member (a square having a size corresponding to the window 46). It can be smoothly dropped onto the document table without being caught by another member attached or attached) . Therefore, it is possible to prevent the alignment of the stacked originals from being disturbed and the originals from being folded.
In addition, according to the present invention, the wear-resistant member that forms part of the document positioning surface of the side fence and the side fence moving means are integrally configured, so that assembly is easy and low cost, and the apparatus is downsized. It is suitable for.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an automatic document feeder showing an embodiment of the present invention.
2 is a perspective view showing a configuration of a side fence in the automatic document feeder of FIG. 1. FIG.
FIG. 3 is a cross-sectional view of the side fence of FIG.
4 is a view showing a method for assembling the side fence of FIG. 2; FIG.
5 is a cross-sectional view of the SADF paper feeding unit of FIG. 1. FIG.
[Explanation of symbols]
1, 1a, 1b Side fence 2 End fence 3 Document table 4 Document 6 Paper feed belt 36 Rack 37 Screw 38 Positioning surface 39 Wall 40 Through hole 46 Window

Claims (1)

An automatic document feeder that is mounted on a copying machine, feeds and separates documents placed on a document table one by one, and circulates according to the number of copies,
At least one pair of side fences for positioning the documents stacked on the document table in the document width direction, and a side fence for changing the distance between the pair of side fences according to the width direction size of the document. And moving means,
A part of the document positioning surface of the pair of side fences is formed of a metal wear-resistant member, and the metal wear-resistant member is formed integrally with the side fence moving means. Automatic document feeder.

Images