This application claims priority under 35 U.S.C. ยง119 from Japanese Patent Application No. 2007-155835 filed on Jun. 13, 2007. The entire subject matter of the application is incorporated herein by reference.
1. Technical Field
The following description relates to one or more document feeders provided to an image forming device.
2. Related Art
Japanese Patent Provisional Publication No. 2007-51005 (hereinafter referred to as '005 Publication) discloses an automatic document feeder, which is applied to an image forming device having a scanner unit and provided with a tray having a loading surface on which a document is placed.
Further, the automatic document feeder is provided with a spindle, holder, paper feed roller, and separation roller so as to supply the document on the loading surface to the scanner unit on a sheet-by-sheet basis (see FIG. 2 of '005 Publication).
The spindle is provided to extend, above the tray, in a direction that is parallel to the loading surface and perpendicular to a carrying direction in which the document is conveyed, and to be rotated to carry the document. The holder is swingably provided to the spindle. The paper feed roller is rotatably provided to the holder at an upstream side in the carrying direction so as to be driven in accordance with the rotation of the spindle. The separation roller is provided at a downstream side in the carrying direction within the holder so as to be rotated integrally with the spindle.
Further, the automatic document feeder includes a detecting unit configured to detect whether a document is placed in the tray (see FIGS. 2 to 4 of '005 Publication). Specifically, the detecting unit has an actuator protruding upward from the tray in a position away from the paper feed roller obliquely toward an upstream side in the carrying direction. The actuator is swingably supported at a backside of the loading surface so as to be moved owing to contact with the document on the loading surface. The detecting unit checks whether a document is placed in the tray by detecting, with a sensor, the downward movement of the actuator caused by the weight of the document in the tray.
The automatic document feeder configured as above checks with the detecting unit whether a document is placed in the tray, when receiving an instruction to supply the document to the scanner. When detecting the document placed in the tray, the aforementioned automatic document feeder causes the spindle, paper feed roller, and separation roller to rotate and feeds the document to the scanner on a sheet-by-sheet basis.
However, sometimes the aforementioned automatic document feeder cannot certainly detect whether a document is placed in the tray.
Specifically, a document set in the automatic document feeder is sometimes curled when the document is bent by a user or colorant is transferred widely onto one side of the document for photographic image printing. When the curled document is placed on the loading surface, the actuator, which is located away from the paper feed roller, might not be moved down since the document is curled up above the actuator. In this case, even though the document is placed in the tray, the detecting unit cannot detect it, and it is impossible to perform an automatic paper feeding operation. This kind of failure is particularly likely to be caused when the document is curled in a direction perpendicular to the carrying direction.
Aspects of the present invention are advantageous to provide one or more improved document feeders and image forming devices that make it possible to more certainly detect whether a document is placed in a tray.
According to aspects of the present invention, a document feeder, which is configured to feed a document in a first direction, includes a tray configured to load a document or a set of documents on a loading surface thereof, a spindle rotatably provided over the tray to extend in a second direction that is parallel to the loading surface and perpendicular to the first direction, a holder swingably provided to the spindle, a feed roller rotatably provided to the holder at an upstream side in the first direction, the feed roller being configured to be driven by the spindle in contact with the document on the loading surface and feed the document in the first direction, a separation roller provided at a downstream side in the first direction within the holder, the separation roller being configured to be rotated integrally with the spindle and separate a document from the documents on the loading surface on a sheet-by-sheet basis, first and second contact portions disposed along the second direction to contact the document on the loading surface, and a detecting unit configured to detect whether a document is loaded on the loading surface, the detecting unit including an actuator provided between the first contact portion and the second contact portion, the actuator projecting upward from the loading surface and being configured to be moved down due to contact with the document on the loading surface.
In some aspects of the present invention, it is possible to press the document against the loading surface of the tray with the first and second contact portions. Further, the actuator establishes contact with the document between the first and second contact portions. Therefore, even though a curled document is placed on the loading surface of the tray, the actuator contacts the document made flat by the first and second contact portions, and is certainly moved down. Accordingly, the detecting unit of the document feeder can certainly detect whether a document is loaded on the loading surface, even when the document is curled at both ends thereof in the second direction.
According to another aspect of the present invention, an image forming device includes a scanner unit configured to scan an image formed on a document, and a document feeder configured to feed a document in a first direction to the scanner unit. The document feeder includes a tray configured to load a document or a set of documents on a loading surface thereof, a spindle rotatably provided over the tray to extend in a second direction that is parallel to the loading surface and perpendicular to the first direction, a holder swingably provided to the spindle, a feed roller rotatably provided to the holder at an upstream side in the first direction, the feed roller being configured to be driven by the spindle in contact with the document on the loading surface and feed the document in the first direction, a separation roller provided at a downstream side in the first direction within the holder, the separation roller being configured to be rotated integrally with the spindle and separate a document from the documents on the loading surface on a sheet-by-sheet basis, first and second contact portions disposed along the second direction to contact the document on the loading surface, and a detecting unit configured to detect whether a document is loaded on the loading surface, the detecting unit including an actuator provided between the first contact portion and the second contact portion, the actuator projecting upward from the loading surface and being configured to be moved down due to contact with the document on the loading surface.
With the image forming device configured as above, the same effect as the aforementioned document feeder can be provided.
It is noted that various connections are set forth between elements in the following description. It is noted that these connections in general and, unless specified otherwise, may be direct or indirect and that this specification is not intended to be limiting in this respect.
Hereinafter, first and second embodiments according to aspects of the present invention will be described with reference to the accompanying drawings.
As shown in
<Image Forming Unit>
The image forming unit 2 is, as illustrated in
At an upper face side of the image forming unit 2, a catch tray 2A into which a paper is discharged toward the front side from the rear side thereof is provided in a recessed form. The image forming unit 2 is configured to form an image on a paper based upon image data externally transmitted or image data of an original document scanned by the scanner unit 8, and to discharge the paper with the image formed thereon into the catch tray 2A.
<Scanner Unit>
As shown in
As illustrated in
The image sensor 81 is a linear type sensor with a plurality of photodiodes aligned in the front-to-rear direction. Further, the image sensor 81, normally located at the right side in the casing 8A, is configured to be shifted in the right-to-left direction with a scanning mechanism (not shown).
As shown in
The scanner unit 8 configured as above can scan an original document on a sheet-by-sheet basis. When the document cover 8B is opened, a document is placed on the platen glass 82, and the document cover 8B is closed, the document is scanned by the image sensor 81 that is moved in the right-to-left direction.
In addition, the scanner unit 8 can scan two or more documents successively through the automatic document feeder 1. When the documents are automatically supplied to the scanner unit 8 along a carrying route P (see
<Automatic Document Feeder>
As shown in
As shown in
As shown in
As shown in
The spindle 20 is a long metal cylindrical shaft body provided to extend along the loading surface 11 perpendicularly to the carrying direction F. As shown in
As shown in
As shown in
The paper feed roller 40 is configured to be rotated in contact with an uppermost surface of the document placed on the loading surface 11 and to feed the document in the carrying direction F. The separation roller 50 is configured to carry the document fed by the paper feed roller 40 while pressing the document against a separation pad (not shown) provided at the tray 10 side to face the separation roller 50 so as to separate the document on a sheet-by-sheet basis. As described above, the upstream side of the holder 30 in the carrying direction F is configured to be normally swung down due to its own weight. Hence, as shown in
Additionally, as shown in
Further, as shown in
A driving gear 59 is fixed to a side end 50B of the separation roller 50 at the second contact portion 32 side. In addition, a driven gear 49 is fixed to the side end 40B of the paper feed roller 40 at the second contact portion 32 side. Further, an intermediate gear 48 is provided between the driving gear 59 and driven gear 49. The intermediate gear 48 is configured to transmit a driving force from the driving gear 59 to the driven gear 49, and rotatably supported by the holder 30. Therefore, when the separation roller 50 is rotated integrally with the spindle 20, the driven gear 49 is thereby rotated via the driving gear 59 and intermediate gear 48 in the same direction as the separation roller 50. As a consequence, the paper feed roller 40 is rotated in the same direction as the spindle 20 and the separation roller 50.
The detecting unit 60 is configured to detect whether a document is placed in the tray 10, and, as illustrated in
As shown in an enlarged view of
The end 70A of the actuator 70 disposed as above is located between the first contact portion 31 and second contact portion 32. Additionally, the end 70A of the actuator 70 is located between the side end 40A of the paper feed roller 40 and the first contact portion 31. Further, the end 70A of the actuator 70 is located between the side end 50A of the separation roller 50 at the first contact portion 31 side and the side end 40A of the paper feed roller 40 at the first contact portion 31 side. The reason why the end 70A of the actuator 70 is configured to be located as above is, as described below, to enable the detecting unit 60 to more certainly perform a detecting operation.
In the detecting unit 60 configured as above, when a document is placed on the loading surface 11, as shown in
As shown in
The guide plate 28 is, as shown in
As illustrated in
In the automatic document feeder 1 configured as above in the first embodiment, as shown in
Then, when receiving an instruction to supply a document to the scanner unit 8, the automatic document feeder 1 controls the detecting unit 60 to check whether a document is placed in the tray 10 by detecting the displacement of the end 70A of the actuator 70 with the photo-micro-sensor 61.
Next, the automatic document feeder 1 controls the driving mechanism 25 in response to the detection result of the detecting unit 60 to rotate the spindle 20 such that the document 7 is conveyed. Thereby, the paper feed roller 40 and separation roller 50 are as well rotated in the same direction as the spindle 20, and the document 7 placed on the loading surface 11 of the tray 10 is supplied on a sheet-by-sheet basis along the carrying route P. Thus, the document 7 is conveyed by the turning-down roller 29, driven rollers 29A and 29B, and guide plate 28, then scanned by the image sensor 81 while passing over the image sensor 81, and thereafter discharged onto the upper face of the document cover 8B by the discharge roller 27 and driven roller 27A.
In this manner, the scanner unit 8 can automatically scan two or more documents with the automatic document feeder 1.
As described above, the automatic document feeder 1 of the first embodiment can press the document 7 against the loading surface 11 of the tray 10 with the first contact portion 31 provided at one end side of the holder 30 in the direction perpendicular to the carrying direction F and the second contact portion 32 provided at the other end side of the holder 30. Further, the end 70A of the actuator 70 contacts the document 7 between the first contact portion 31 and the second contact portion 32. Therefore, as shown in
Accordingly, the automatic document feeder 1 in the first embodiment can more certainly detect whether a document is placed in the tray 10.
Additionally, in the automatic document feeder 1, the first contact portion 31 and the second contact portion 32 are provided to the holder 30 so as to be located outside both the ends 40A and 40B of the paper feed roller 40 in the direction perpendicular to the carrying direction F. Further, the end 70A of the actuator 70A is provided between the side end 40A of the paper feed roller 40 and the first contact portion 31. Thereby, in the automatic document feeder 1 of the first embodiment, the end 70A of the actuator 70 can be located so as not to overlap the paper feed roller 40 when viewed in the carrying direction F. In other words, as the end 70A of the actuator 70 is disposed within a space occupied by the holder 30, the automatic document feeder 1 can be prevented from extending long in the carrying direction F. In addition, the end 70A of the actuator 70 can be disposed within a short range between the side end 40A of the paper feed roller 40 and the first contact portion 31. Therefore, it is possible to easily make the document to be flat, even though the document is curled in the direction perpendicular to the carrying direction F. Hence, the automatic document feeder 1 in the first embodiment can certainly provide the aforementioned effect expected in the present invention.
Further, in the automatic document feeder 1 of the first embodiment, the end 70A of the actuator 70 is disposed between the side end 50A of the separation roller 50 and the side end 40A of the paper feed roller 40, when viewed in the carrying direction F. Therefore, in the automatic document feeder 1, the actuator 70 can be located at an upstream side in the carrying direction F within such a range in the direction perpendicular to the carrying direction F that the separation roller 50 presses the document 7 against the loading surface 11. Thus, the aforementioned effect can more certainly be provided.
Further, in the automatic document feeder 1 of the first embodiment, the driving gear 59 and driven gear 49 are disposed at the second contact portion 32 side. Therefore, it is possible to make short a distance between the side end 40A of the paper feed roller 40 and the first contact portion 31. Thereby, in the automatic document feeder 1, since the actuator 70 can be disposed within a short range between the both the side end 40A and the first contact portion 31 located close to each other, the aforementioned effect can further certainly be provided.
In an automatic document feeder in a second embodiment, the paper feed roller 40 of the automatic document feeder 1 in the first embodiment is changed to a paper feed roller 240 as shown in
In the second embodiment, as shown in
In the second embodiment, a cylindrical surface at the rear side of the groove 240A of the paper feed roller 240 is a first contact surface 231, and that at the front side of the groove 240A of the paper feed roller 240 is a second contact surface 232. It is noted that the first contact surface 231 and second contact surface 232 double as the first contact portion 31 and second contact portion 32, respectively, and therefore the first contact portion 31 or the second contact portion 32 may be omitted.
The opening 78 of the tray 10 is provided as a through hole beneath the groove 240A of the paper feed roller 240. The end 70A of the actuator 70 projects upward from the opening 78 of the tray 10 and located within a range in which the groove 240A extends in the front-to-rear direction.
In the automatic document feeder configured as above in the second embodiment, the first contact surface 231 and the second contact surface 232 are placed pretty close to the end 70A of the actuator 70. Therefore, the automatic document feeder of the second embodiment can further certainly provide the same effect as the automatic document feeder 1 of the first embodiment.
Hereinabove, the embodiments according to aspects of the present invention have been described. The present invention can be practiced by employing conventional materials, methodology and equipment. Accordingly, the details of such materials, equipment and methodology are not set forth herein in detail. In the previous descriptions, numerous specific details are set forth, such as specific materials, structures, chemicals, processes, etc., in order to provide a thorough understanding of the present invention. However, it should be recognized that the present invention can be practiced without reapportioning to the details specifically set forth. In other instances, well known processing structures have not been described in detail, in order not to unnecessarily obscure the present invention.
Only exemplary embodiments of the present invention and but a few examples of its versatility are shown and described in the present disclosure. It is to be understood that the present invention is capable of use in various other combinations and environments and is capable of changes or modifications within the scope of the inventive concept as expressed herein.
Number | Date | Country | Kind |
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2007-155835 | Jun 2007 | JP | national |