Patent Application
20210400155
The present disclosure relates to an image reading apparatus that reads an image of a document and an image forming apparatus that includes the image reading apparatus.
An image reading apparatus, such as a scanner, and an image reading apparatus mounted on, for example, a copying machine, have been provided with an auto document feeder (hereinafter referred to as an ADF) that continuously feeds sheets of a document stacked on a document tray, conveys the document to an image reading position, reads an image of the document, and thereafter discharges the document onto a discharge tray. Examples of the ADF include an ADF that aligns a width direction of a document by a user placing the document on the document tray and operating a side regulating plate arranged on the document tray.
Meanwhile, a known technology regarding the document tray to be used for the ADF is to incline the document tray toward a front side when the user sets a document to align the document using its own weight. With a configuration discussed in Japanese Patent Application Laid-Open No. H07-072685, a document tray is supported to be rotationally movable about a rotating shaft, and can be inclined toward the front side when the user sets a document on the document tray. With this configuration, the document set by the user moves under its own weight, and the document is aligned along a document abutment portion on the front side of the document tray.
In a case where the document tray is largely inclined toward the front side, a large space is required in an upper portion or a lower portion of the document tray, thereby upsizing an apparatus. Hence, the document tray has preferably a small inclination angle when the user sets the document on the document tray.
According to the configuration discussed in Japanese Patent Application Laid-Open No. H07-072685, however, since a sheet stacking surface of the document tray is a flat surface, a contact area between the document and the sheet stacking surface is equal in size to the document, and large frictional force that prevents the document from moving under its own weight occurs. There is therefore an issue that the configuration causes a large inclination angle necessary for moving the document set on the document tray under its own weight and aligning the document.
The present disclosure is directed to providing an image reading apparatus capable of decreasing an inclination angle of a document tray necessary for moving a document set on a document tray under its own weight and aligning the document, and an image forming apparatus that includes the image reading apparatus.
According to an aspect of the present disclosure, an image reading apparatus includes a first stacking unit including a sheet stacking surface on which a document is to be stacked, and an abutment portion on which one end portion of the document stacked on the sheet stacking surface in a width direction of the document abuts, a feeding unit configured to feed the document stacked on the first stacking unit in a feed direction orthogonal to the width direction, a reading unit configured to read an image of the document conveyed by the feeding unit, a second stacking unit onto which the document whose image is read by the reading unit is to be discharged, a rotating shaft that extends in the feed direction and configured to support the first stacking unit so as to be rotationally movable, and a plurality of protrusions that extends in a direction at a predetermined angle with respect to the feed direction, is arranged on the sheet stacking surface, and protrudes from the sheet stacking surface.
Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
An exemplary embodiments of the present disclosure will now be described with reference to the accompanying drawings.
A schematic configuration of an image forming apparatus 101 according to an exemplary embodiment will be described with reference to
The image forming apparatus 101 includes an apparatus body 101A and an image reading apparatus 103, as illustrated in
The apparatus body 101A includes an image forming unit 133 for forming an image on the sheet P, which is the recording material, and a sheet feeding unit 34 that feeds the sheet P to the image forming unit 133. The sheet feeding unit 34 includes sheet storage units 137a, 137b, 137c, and 137d, which are capable of storing sheets in mutually different sizes. Sheets stored in each sheet storage unit are sent out by a pickup roller 32, separated sheet by sheet by a feed roller 33a and a retard roller 33b, and handed over to a corresponding pair of conveying rollers 131. The sheet P is sequentially handed over to a plurality of pairs of conveying rollers 131 arranged along a sheet conveying path, and then conveyed to a pair of registration rollers 136.
The sheet P loaded on a manual feed tray 137e by a user is fed to the inside of the apparatus body 101A by a feed roller 138 and conveyed to the pair of registration rollers 136. The pair of registration rollers 136 stops a leading end of the sheet P to correct skew feed, and also resumes conveyance of the sheet P in accordance with progress of an image formation operation, which is a process of forming a toner image performed by the image forming unit 133.
The image forming unit 133 that forms an image on the sheet P is an electrophotography image forming unit that includes a photosensitive drum 121, which is a photosensitive body. The photosensitive drum 121 is rotatable along a conveying direction of the sheet P. A charger 118, an exposure device 123, a developing device 124, a transfer charger 125, a separating charger 126, and a cleaner 127 are arranged around the photosensitive drum 121. The charger 118 uniformly charges the surface of the photosensitive drum 121. The exposure device 123 exposes the photosensitive drum 121 with light based on image information input from, for example, the image reading apparatus 103, and forms an electrostatic latent image on the photosensitive drum 121.
The developing device 124 contains developer including toner, and supplies charged toner to the photosensitive drum 121 to develop the electrostatic latent image to a toner image. The toner image carried by the photosensitive drum 121 is transferred to the sheet P, which is conveyed from the pair of registration rollers 136, by a bias electric field formed by the transfer charger 125. The sheet P to which the toner image is transferred is separated from the photosensitive drum 121 by the bias electric field formed by the separating charger 126, and is conveyed to a fixing unit 129 by a pre-fixing conveying unit 128. Attached materials, such as transfer residual toner that has not being transferred to the sheet P and left on the photosensitive drum 121, is removed by the cleaner 127, and the photosensitive drum 121 prepares itself for the next image formation operation.
The sheet P conveyed to the fixing unit 129 undergoes fixing processing including pressing and heating of the toner image while being nipped and conveyed by a pair of rollers. Toner is melted by this processing and thereafter fixated, whereby an image is fixed on the sheet P. In a case where image-output has been completed, the sheet P provided with the fixed image is discharged onto a discharge tray 130 protruding outward from the apparatus body 101A, via a pair of discharge rollers 40. In a case where an image is formed on the back surface of the sheet P in double-sided printing, the sheet P that has passed through the fixing unit 129 is flipped over by a reverse unit 139 such that the front surface and the back surface are replaced with each other, and then conveyed to the pair of registration rollers 136 by a double-sided conveying unit 140. The sheet P on which the image is formed again by the image forming unit 133 is discharged onto the discharge tray 130.
The image forming unit 133 described above is one example of an image forming unit, and an image forming unit of an inkjet method or a print mechanism of an offset print method may be used as the image forming unit.
A schematic configuration of the image reading apparatus 103 will now be described with reference to
As illustrated in
Rotating the rotating shaft 11 also enables the document tray 2 to rotationally move about the rotating shaft 11 as a rotation center in an integral manner A motor 13 serving as a drive unit is arranged inside the conveying unit 12, and the document tray 2 is rotationally moved by rotational drive force of the motor 13. While the motor 13 is arranged inside the conveying unit 12 in the present exemplary embodiment, the arrangement of the motor 13 is not limited thereto. For example, the motor 13 may be arranged inside the document tray 2, or may be arranged close to the drive unit for providing rotational drive force to each conveying roller described below. The document tray 2 is configured such that the whole of the document tray 2 rotationally moves in the present exemplary embodiment, but may be configured such that only part of the document tray 2 (e.g., the sheet stacking surface 2a) rotationally moves.
The ADF 1 is provided with the pickup roller 4, a feed roller 5, a separating roller 6, a conveying roller 7, a conveying roller 8, a conveying roller 9, and a discharge roller 10. Further, an image reading section E is arranged on a downstream side in a conveying direction of the conveying roller 8. The image reading section E includes a front surface reading unit 14 mounted in the reader 20 and a back surface reading unit 15 mounted in the ADF 1.
The document D on the document tray 2 is sent out by the pickup roller 4 serving as a feeding unit, to the feed roller 5. The document is separated sheet by sheet by frictional force occurring between the feed roller 5 and the separating roller 6 urged by a spring from below the separating roller 6. The separated document D is sent to the image reading section E by the conveying rollers 7 and 8. Images on both sides of the document D sent to the image reading section E are read by the front surface reading unit 14 and the back surface reading unit 15, which constitute the reading unit. The document D is then conveyed to the discharge roller 10 by the conveying roller 9, and discharged onto the discharge tray 3 by the discharge roller 10.
A description will now be given of a configuration of the document tray 2 with reference to
As illustrated in
The angle θ1 is assumed to be 15° in the present exemplary embodiment, but is not limited to this value. The angle θ1 is preferably in a range of 0°<θ1<40°. This is because, in a case where the sheet stacking surface 2a is inclined by 40° or larger, there is a possibility that the set document D buckles under its own weight at the time of abutting the document abutment portion 2b. Further, a length in the feed direction F of the document abutment portion 2b is assumed to be 150 mm in the present exemplary embodiment in consideration of visibility at the time of setting the document D, but is not limited to this value.
As described above, the user sets the document D in the first state in which the document tray 2 is inclined toward the front side. In the state in which the document tray 2 is inclined toward to the front side, however, the ADF 1 is unable to perform the feed operation. Thus, after the document D is set, the document tray 2, with the document D remaining to be set, rotationally moves such that the position of the document abutment portion 2b is higher than the position in the first state illustrated in
When the document tray 2 is viewed from the direction along the feed direction F, the angle θ1 of the sheet stacking surface 2a with respect to the horizontal direction at the time of the start of the feed operation is assumed to be 0° in the present exemplary embodiment. However, the arrangement is only required to smoothly connect the sheet stacking surface 2a and the conveying path of the conveying unit 12 with each other at the time of the start of the feed operation. Hence, at the time of the start of the feed operation, the sheet stacking surface 2a may be somewhat inclined with respect to horizontal direction in a range in which the feed operation can be performed.
A detailed configuration of the sheet stacking surface 2a of the document tray 2 will now be described with reference to
As illustrated in
As described above, the document tray 2 is in the first state of being inclined toward the front side when the user sets the document D on the document tray 2. The document D set by the user moves on the inclined sheet stacking surface 2a under its own weight, and one end in the width direction of the document D abuts the document abutment portion 2b. The document D is thereby aligned. In the present exemplary embodiment, the document D is in contact only with the ribs 2c arranged on the sheet stacking surface 2a when moving on the sheet stacking surface 2a, and thereby frictional force that prevents the movement of the document D is small. For this reason, the present embodiment makes the set document D to easily move under its own weight, and decreases an inclination angle of the document tray 2 necessary for moving the set document D under its own weight and aligning the document D, in comparison with a case where no rib 2c is arranged on the sheet stacking surface 2a. Furthermore, decreasing the inclination angle of the document tray 2 for aligning the document D under its own weight can decrease a space for the document tray 2 to rotationally move, and downsize the apparatus.
If there is no rib 2c, the inclination angle θ1 of the sheet stacking surface 2a for aligning the document D under its own weight is approximately 30°. According to the present exemplary embodiment in which the ribs 2c are arranged on the sheet stacking surface 2a, in contrast, the inclination angle θ1 of the sheet stacking surface 2a for aligning the document D under its own weight is about 15°.
According to the present exemplary embodiment, the inclined portion 2d is arranged in the rib 2c on the upstream side in the feed direction F. Hence, the leading end of the document D moves along the inclined portion 2d when the user sets the document D on the document tray 2 from a right side surface of the ADF 1 along the feed direction F. This configuration can prevent the document D from getting stuck with the ribs 2c and being damaged.
A modification example of the ribs 2c arranged on the sheet stacking surface 2a will now be described with reference to
The ribs 2c exemplified in the exemplary embodiment described above have a shape linearly extending in a direction having the predetermined angle θ2 with respect to the feed direction F. However, the shape of the ribs 2c is not limited thereto, and part of the ribs 2c may be inclined in another direction. Furthermore, the ribs 2c may extend in a curved line. In this case, an angle of a straight line connecting both end portions of each rib 2c in the curved line with respect to the feed direction F is assumed to be the predetermined angle θ2.
Alternatively, the ribs 2c may have such a shape as that a plurality of protrusions is linearly arranged on the sheet stacking surface 2a.
According to the present exemplary embodiment, it is possible to provide the image reading apparatus capable of decreasing the inclination angle of the document tray for moving the document set on the document tray under its own weight and aligning the document, and the image forming apparatus that includes the image reading apparatus.
While the present disclosure has been described with reference to exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2020-106244, filed Jun. 19, 2020, which is hereby incorporated by reference herein in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-106244 | Jun 2020 | JP | national |
