JP3639693B2 - Sheet material feeding apparatus and image processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sheet material feeding apparatus that separates and feeds sheet materials one by one and an image processing apparatus such as an image forming apparatus and an image reading apparatus using the sheet material feeding apparatus.
[0002]
[Prior art]
7 and 8 are schematic views of a conventional sheet material feeding apparatus that separates and feeds sheet materials such as documents and recording sheets one by one to an image reading apparatus, an image forming apparatus, and the like. FIG. 7 shows an example of an image reading apparatus, FIG. 7 is a schematic sectional view of a conventional sheet material feeding apparatus, and FIG. 8 shows a pressure release state of a separation pad of the sheet material feeding apparatus. It is a schematic explanatory drawing which shows.
[0003]
In the figure, reference numeral 50 denotes a feeding roller that applies a feeding force to the document S as a sheet material, 51 denotes a frame, 52 denotes an image reading sensor for reading information written on the document S, and 53 denotes the reading sensor. Reference numeral 52 denotes a scan roller that rotates while pressing the document S. Reference numeral 54 denotes a separation pad that is a separation friction member that has a friction member and presses the document S against the feeding roller 50. The feed roller 50 is urged by. 56 is a separation pad pressure release lever for separating the separation pad 54 from the feeding roller 50, and 57 is a conveyance guide for guiding the document S.
[0004]
In the sheet material feeding apparatus, a bundle of documents S is stacked on a feeding tray (not shown), and the stacked documents S are subjected to the effect of the inclined portion upstream of the feeding nip portion of the conveyance guide 57 and the feeding roller 50. The sheet is fed into the nip formed by the feeding roller 50 and the separation pad 54 by the rotation operation. Several (2, 3) documents S fed to the nip between the feeding roller 50 and the separation pad 54 are separated by the separation pad 54 at the nip portion, and only one sheet is fed. The sheet is conveyed while being pressed against the feeding roller 50 due to the shape on the downstream side of the nip portion. In the case of the image reading apparatus, the fed document S enters the nip between the image reading sensor 52 and the scan roller 53, and is conveyed and discharged.
[0005]
Further, when the document S is jammed (paper jam), the release lever 56 of the separation pad 54 is moved in the direction of the arrow in FIG. 7, so that the separation pad 54 and the feeding roller 50 are moved as shown in FIG. The nip of the sheet is opened, and the jammed paper can be processed by pulling out the jammed document in the document transport direction or the counter-transport direction.
[0006]
[Problems to be solved by the invention]
However, in the configuration of the sheet material feeding apparatus described above, when a plurality of sheet materials are set, the apparent thickness of the sheet material is so thick that it is not greatly affected by the back tension of the separation pad 54. When only one sheet is set and fed, or in the case of a sheet material in the vicinity of the last sheet material (the last two or three sheets) when a plurality of sheets are set, the rear end of the fed sheet material is fed The sheet is conveyed while always in contact with the separation pad 54 until it passes through the nip between the roller 50 and the separation pad 54. Therefore, a minute loop or the like is likely to occur in the width direction of the sheet material, and the back tension acts on the sheet material to be conveyed.
[0007]
However, the position of the back tension is offset from the center in the width direction of the sheet material due to the influence of the loop or the like, and the conveyance of the sheet material is not stable and causes skewing.
[0008]
In particular, when a thin sheet material (for example, a sheet material of 52.7 g / m ² or less) is transported, the sheet material itself is not affected by the back tension and easily has a loop in the width direction of the sheet material.
[0009]
In the case of a sheet material of normal weight (for example, a sheet material of 64 g / m ² ), even when the sheet material is going to be skewed, a width regulating plate (see FIG. It is conceivable to endure skewing with the waist of the sheet material. However, in the case of thin sheet material, there is no waist, so it is not possible to rely on the width regulation plate, and the sheet material buckles in the width direction on the feeding tray, causing skew in the feeding unit. Become.
[0010]
Furthermore, when the thin sheet material is skewed, the end of the sheet material is likely to be scratched or damaged, which causes a large jam. In addition, skewing in the feeding unit may deteriorate the image reading accuracy when the sheet material enters the image reading unit or the like.
[0011]
SUMMARY OF THE INVENTION The present invention solves the above-described problems, and an object of the present invention is to provide a sheet material feeding apparatus capable of feeding a thin sheet material without skewing the sheet material even when only one sheet material is used. And an image processing apparatus using the same.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, a representative configuration according to the present invention is a sheet material feeding device that separates and feeds a sheet material, a feeding rotating body that applies a feeding force to the sheet material, Separating friction member having a friction member for separating sheet materials fed by the feeding rotating body in pressure contact with the sheet material, and for separating the friction member from the feeding rotating body And a resilient member for bringing the sheet material into contact with the feeding rotating body in a state where the friction member is separated from the feeding rotating body by the separating means.
[0013]
In the above configuration, when feeding only one sheet material or the remaining several sheet materials, the sheet material is fed by the feeding rotator while the separation friction member is separated from the feeding rotator. By feeding, even a thin sheet material having no waist can be fed without buckling.
[0014]
For this reason, by using the sheet material feeding device, it is possible to accurately read information written on a thin sheet material or to form an image on the sheet material.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of a sheet material feeding apparatus and an image processing apparatus using the same according to the present invention will be described with reference to the drawings.
[0016]
[First Embodiment]
1 to 4 show examples in which a sheet material feeding device is applied to an image reading device as an image processing device. FIG. 1 is a cross-sectional explanatory view of the sheet material feeding device in which the separation friction member presses the sheet material against the feeding rotating body, and FIG. 2 is a cross section of the state in which the separation friction member is separated from the feeding rotation body. FIG. 3 is a schematic front view of a state in which the separation friction member presses the sheet material against the feeding rotator and is separated from the feeding rotator, and FIG. 4 is a schematic explanation of the overall configuration of the image reading apparatus. FIG.
[0017]
Here, the overall configuration of the image reading apparatus will be described first, and then the configuration of the sheet material feeding apparatus used in the reading apparatus will be described.
[0018]
{Overall configuration of image reading apparatus}
As shown in FIG. 4, the image reading apparatus according to the present embodiment has a feeding tray 1 that is attachable and detachable by the locking portions 1 a and 1 b attached to the image processing apparatus main body A, and is set on the feeding tray 1. A plurality of sheets S of documents S is supplied from the feeding port 2 to the sheet material feeding device B.
[0019]
Although the configuration of the sheet material feeding device B will be described in detail later, an image is read from a plurality of documents S by a feeding roller 3 that is a feeding rotating body and a separation pad 4 that is a separation friction member. Separately feed one by one to the image processing means 5. The image processing means 5 includes a contact image sensor 5a and a scan roller 5b that presses the document S against the sensor 5a and conveys the document S. When the document S passes the sensor 5a, the document description information Is read optically. Then, the document S from which the image has been read is discharged from the discharge port 6 to the outside of the apparatus.
[0020]
{Configuration of sheet material feeding device}
As shown in FIGS. 1 to 3, the sheet material feeding device B is provided with a feeding roller 3 which is a feeding rotating body so as to be driven to rotate, and is fed coaxially on both sides of the roller 3. A roller 3a (see FIG. 3) is provided. A separation pad 4 is attached to the feed roller 3 so as to be rotatable about a shaft 4a. A friction member 4 b is attached to the separation pad 4, and the friction member 4 b can be pressed against the feeding roller 3 by being pressed by a compression spring 7.
[0021]
The separation pad 4 has a conveyance guide 8 that guides the document S to the nip portion between the feeding roller 3 and the separation pad 4 and guides the document S fed from the nip portion to the image processing means 5. Is provided. The conveyance guide 8 is located on both sides of the friction member 4 b of the separation pad 4.
[0022]
When the feeding roller 3 is rotated by the feeding start signal, only the uppermost one of the plurality of documents S set on the feeding tray 1 is separated by the frictional force of the friction member 4b. Is fed to the image processing means 5.
[0023]
A pressure release lever 4c constituting a separating means is integrally provided at one end of the separation pad 4. When the original S is jammed, the lever 4c is rotated in the direction of arrow a in FIG. By doing so, as shown in FIG. 2, the separation pad 4 is separated from the feeding roller 3, and the jammed original can be removed.
[0024]
As shown in FIG. 3, an elastically deformable locking claw 4d is provided below the separation pad 4, and the separation pad 4 is separated from the feeding roller 3 by the release lever 4c as described above. In this case, the locking claw 4d is locked in the locking recess 9a provided in the frame 9 of the apparatus main body A, and the separation pad 4 is maintained in a state of being separated from the feeding roller 3.
[0025]
The release amount of the separation pad 4 by the release lever 4 c is determined by the tangent L of the feeding roller 3 drawn by the apex P existing at the downstream side of the nip portion of the conveyance guide 8 shown in FIG. Or at a position slightly closer to the feeding roller 3 side than the tangent line L and set to a minimum amount necessary for jam processing.
[0026]
Further, an elastic member 10 capable of bringing the document S into contact with the feed roller 3 is provided upstream of the nip portion between the feed roller 3 and the separation pad 4 in the document transport direction. The elastic member 10 is constituted by a sheet-like member such as a mylar, a plastic plate, a metal plate, and the elastic force is set to a strength that can press several originals S against the feeding roller 3. ing.
[0027]
In the above-described configuration, when a large number of documents S are set on the feeding tray 1, the separation pad 4 is set so as to be pressed against the feeding roller 3 and fed. Then, as shown in FIG. 3 (a), only the uppermost document S is separated by the frictional force of the friction member 4 b of the separation pad 4 and fed by the feeding roller 3 as in the conventional friction separation. The image is read by the image processing means 5 and discharged from the discharge port 6.
[0028]
Then, when the feeding of the document S proceeds and the last one or several documents are fed, the release lever 4c is operated as shown in FIG. Is separated from the feeding roller 3, and the original is fed in this state.
[0029]
Even when the separation pad 4 is separated from the feeding roller 3, the original S is urged by the feeding roller 3 by the action of the elastic member 10, so that the feeding operation is possible. Further, even after the feeding by the feeding roller 3, the apex P (see FIG. 2) of the conveyance guide 8 is equal to the tangent line L of the feeding roller 3 or closer to the feeding roller 3 than the tangent line L. Is urged to the feeding roller 3 and the feeding roller 3a by the elastic member 10 and the apex P of the conveying guide 8, and is supplied to the image processing means 5 with sufficient conveying force.
[0030]
When the remaining several originals are fed, the pressure applied by the separation pad 4 is released, so that even if the original is a thin sheet material, a minute loop does not occur in the original. Back tension does not act. For this reason, the document is stably fed without being skewed to the image processing means 5, and the image is read with high reading accuracy. In addition, since it is possible to feed only one thin sheet with a very low stiffness, the margin for the sheet material is increased and the range of sheet materials that can be fed is expanded.
[0031]
[Second Embodiment]
Next, FIGS. 5A and 5B show a second embodiment of the present invention. 5 is a schematic front view showing the nip portion between the feeding roller and the separation pad. FIG. 5A is a diagram for explaining the state in which the separation pad presses the sheet material against the feeding roller. FIG. 5B is the separation pad. FIG. 6 is an explanatory diagram of a state where the is separated from the feeding rotating body. The configuration of the image reading apparatus using the sheet material feeding apparatus B is the same as that of the first embodiment described above, and members having the same functions as those of the first embodiment described above are denoted by the same reference numerals. .
[0032]
In the present embodiment, as shown in FIG. 5, ribs 11 are provided on the frame 9 as conveyance guides on both sides of the feeding roller 3. The height of the rib 11 is configured such that the top portion thereof is slightly closer to the feeding roller 3 side than the position of the nip portion between the feeding roller 3 and the separation pad 4 (set as high as A in the figure). .
[0033]
By doing so, the sheet material S fed by the action of the elastic member 10 described above, the nip portion of the feeding roller 3a, the feeding roller 3, and the separation pad 4, as shown in FIG. In this embodiment, the rib 11 is biased toward the feeding roller 3 side even after separation by the action of the tension in the width direction of the sheet material S and the vertex P of the conveyance guide 8 even after separation.
[0034]
In this embodiment, even when the feeding operation is performed with the separation pad 4 fixed in the pressure release state, as shown in FIG. 5B, the height A of the rib 11 and the action of the feeding roller 3a. The fed sheet material S bends in the width direction and has a tension in the width direction. The tension and the apex P of the conveyance guide 8 are biased toward the feeding roller 3 side. Thereby, even if there is no contact with the separation pad 4, the feeding force of the feeding roller 3 is applied and the sheet is fed. Therefore, even when only one sheet is fed, the sheet material S is fed more stably than in the first embodiment described above.
[0035]
Accordingly, it becomes possible to convey the sheet material more stably than in the first embodiment described above, and since the tension in the width direction of the sheet material S is used, the apparent stiffness of the fed sheet material is increased. Therefore, the margin of the thin paper feeding performance is also increased compared to the first embodiment described above, and the types of sheet materials that can be fed are increased.
[0036]
[Third Embodiment]
Next, FIGS. 6A and 6B show a third embodiment of the present invention. FIG. 6 is a schematic front view showing a nip portion between the feeding roller and the separation pad, (a) is a diagram illustrating a state in which the separation pad presses the sheet material against the feeding roller, and (b) is a separation pad. FIG. 6 is an explanatory diagram of a state where the is separated from the feeding rotating body. In this embodiment, the configuration of the image reading apparatus using the sheet material feeding apparatus B is the same as that of the first embodiment described above, and members having the same functions as those of the first embodiment described above are used. The same reference numerals are given.
[0037]
In this embodiment, a roller 12 is provided instead of the rib 11 in the second embodiment described above. With this configuration, the same effect as that of the second embodiment described above can be obtained, and the friction between the sheet material S and the roller 12 is smaller than that of the rib 11. Therefore, the sheet material can be fed more stably.
[0038]
[Other Embodiments]
In the embodiment described above, an example in which a document is fed as a sheet material and an image described in a document is read and processed by a reading sensor as an image processing unit has been described. However, the sheet material feeding apparatus according to the present invention separates and feeds a recording sheet material. The image forming apparatus that feeds and records and forms a predetermined image on the sheet material by an image forming unit as an image processing unit can be suitably used.
[0039]
Further, the feeding rotating body is not necessarily a roller-shaped one, and may be a rotating body such as a rotating belt.
[0040]
【The invention's effect】
Since the present invention is configured as described above, when feeding only one sheet material or several sheet materials, the sheet material is rotated while the separation friction member is separated from the feeding rotating body. By feeding with a body, even a thin sheet material without a waist can be fed without buckling.
[0041]
For this reason, by using the sheet material feeding device, it is possible to accurately read information written on a thin sheet material or to form an image on the sheet material.
[Brief description of the drawings]
FIG. 1 is an explanatory cross-sectional view of a state in which a separation pad of a sheet material feeding device presses a sheet material against a feeding rotating body.
FIG. 2 is a cross-sectional explanatory view showing a state in which a separation pad is separated from a feeding rotating body.
3A is a schematic front view of a state in which the separation pad presses the sheet material against the feeding rotator, and FIG. 3B is a schematic front view of the state in which the separation pad is separated from the feeding rotator. It is.
FIG. 4 is a schematic explanatory diagram of an overall configuration of the image reading apparatus.
FIG. 5 is a schematic front view illustrating a nip portion between a feeding roller and a separation pad according to a second embodiment, and (a) is a diagram illustrating a state in which the separation pad presses a sheet material against the feeding roller. b) is an explanatory view showing a state in which the separation pad is separated from the feeding rotating body.
FIG. 6 is a schematic front view illustrating a nip portion between a feeding roller and a separation pad according to a third embodiment. FIG. 6A is a diagram illustrating a state in which the separation pad presses the sheet material against the feeding roller. b) is an explanatory view showing a state in which the separation pad is separated from the feeding rotating body.
FIG. 7 is a schematic cross-sectional explanatory view of a conventional sheet material feeding device.
FIG. 8 is a schematic explanatory diagram illustrating a pressure release state of a separation pad of a sheet material feeding device.
[Explanation of symbols]
A ... apparatus main body B ... sheet material feeding apparatus S ... document 1 ... feeding trays 1a, 1b ... locking portion 2 ... feeding port 3 ... feeding roller 3a ... feeding roller 4 ... separation pad 4a ... shaft 4b ... Friction member 4c ... release lever 4d ... locking claw 5 ... image processing means 5a ... image sensor 5b ... scan roller 6 ... discharge port 7 ... compression spring 8 ... transport guide 9 ... frame 9a ... locking recess
10… Elastic member
11… ribs
12… Colo

Claims (5)

In the sheet material feeding device that separates and feeds the sheet material,
A feeding rotating body for applying a feeding force to the sheet material;
A separation friction member having a friction member for pressing the sheet material and separating the sheet material fed by the feeding rotating body one by one;
A separating means for separating the friction member from the feeding rotating body;
An elastic member for bringing the sheet material into contact with the feeding rotator in a state where the friction member is separated from the feeding rotator by the separating means;
A sheet material feeding device comprising: The elastic member is provided on the upstream side in the sheet material conveyance direction with respect to the nip portion between the feeding rotating body and the friction member, and the sheet material conveyance guide is provided on the downstream side with respect to the nip portion. 2. The sheet material feeding device according to claim 1, wherein the sheet material is urged toward the feeding rotating body by a guide. The sheet material feeding apparatus according to claim 2, wherein the conveyance guide is provided on the separation friction member. The sheet feeding apparatus according to claim 2, wherein the conveyance guide is a roller member. In an image processing apparatus that feeds a sheet material and processes an image,
The sheet material feeding device according to any one of claims 1 to 4, for feeding a sheet material,
An image processing means for reading an image described on the fed sheet material or forming an image on the sheet material;
An image processing apparatus comprising:

Images