Patent Application
20220043384
This application is based on and claims the benefit of Japanese Patent Application No. 2020-132184 filed on Aug. 4, 2020, the contents of which are hereby incorporated by reference.
The present disclosure relates to a sorting device that is provided in an in-body discharge space in an image forming apparatus to sort sheets discharged from the image forming apparatus in the sheet width direction orthogonal to the sheet discharge direction. The present disclosure also relates to an image forming apparatus that incorporates such a sorting device.
There are known trays that are provided in an in-body discharge space in an image forming apparatus and on which sheets discharged from the image forming apparatus are stacked. A user retrieves the sheets stacked on the tray from one side in the sheet width direction orthogonal to the sheet discharge direction, that is, from the front side of the in-body discharge space. To permit the user easy retrieval of sheets, a cutout portion is provided in one end part of the tray in the sheet width direction. The cutout portion is formed by cutting away an end part of the tray from one side in the sheet width direction inward in the sheet width direction. The cutout portion is provided at such a position as to overlap the sheets stacked on the tray. The user can put a hand into the cutout portion and grab a bundle of sheets on the tray by holding it from opposite sides in the up-down direction.
Also known are sorting devices that are provided in an in-body discharge space in an image forming apparatus and that sort sheets discharged from the image forming apparatus in the sheet width direction orthogonal to the sheet discharge direction. Such a sorting device includes a base portion provided in a bottom portion of the in-body discharge space and a tray portion provided so as to be reciprocatable in the sheet width direction with respect to the base portion. The sheets discharged from the image forming apparatus are stacked on the tray portion. While the sheets are discharged, the sorting device moves the tray portion in the sheet width direction to displace the stacking position of the sheets, and thereby sorts the sheets.
According to one aspect of the present disclosure, a sorting device is provided in a sheet discharge space in an apparatus body, and shifts the stacking position of discharged sheets in the sheet width direction orthogonal to the sheet discharge direction, thereby to sort the sheets. The sorting device includes a base portion and a tray portion. The base portion is attached to a bottom portion of the sheet discharge space in the apparatus body. The tray portion is supported on the base portion so as to be reciprocatable between a first shift position, in which the tray portion is located at one side in the sheet width direction, and a second shift position, in which the tray portion is located at an other side in the sheet width direction. On the tray portion, the sheets discharged from the apparatus body are stacked. The sheets on the tray portion can be retrieved from one side in the sheet width direction. The tray portion has a cutout portion. The cutout portion is formed by cutting away, with a predetermined width, an end part of the tray portion at one side in the sheet width direction inward across the tray portion. When the tray portion is in the second shift position, the cutout portion is located under the end edge, at one side in the sheet width direction, of the sheets stacked on the tray portion.
An embodiment of the present disclosure will be described below with reference to the accompanying drawings.
As shown in
In the image forming portion 6, along the rotation direction (counter-clockwise in
The photosensitive drum 1 is, for example, a drum of aluminum that has a photosensitive layer deposited on it, and its surface is electrostatically charged uniformly by the charging portion 2.
The charging portion 2 electrically charges the surface of the photosensitive drum 1 uniformly. Usable as the charging portion 2 is, for example, a corona discharge device. Instead of a corona discharge device, use is also possible of a contact-type charging device The exposure unit 3 shines a light beam (e.g., a laser beam) on the photosensitive drum 1 based on document image data read in an image reading portion 18, and thereby forms an electrostatic latent image on the surface of the photosensitive drum 1.
The developing device 4 attaches toner to the electrostatic latent image on the photosensitive drum 1, and thereby forms a toner image. The developing device 4 is supplied with toner from a toner container 5.
The transfer roller 7 transfers the toner image formed on the surface of the photosensitive drum 1 to a sheet conveyed along a sheet conveyance passage 11. The cleaning device 8 includes a cleaning roller, a cleaning blade, or the like that makes line contact with the photosensitive drum 1 in its longitudinal direction. The cleaning device 8 removes residual toner that is left behind on the surface of the photosensitive drum 1 after the transfer of the toner image to the sheet.
The image reading portion 18 includes a scanning optical system, a condenser lens, a CCD sensor, and the like (of which none are illustrated).
Copying operation proceeds as follows. In the image reading portion 18, the image data of a document is read and is converted into an image signal. On the other hand, in the image forming portion 6, the charging portion 2 electrostatically charges uniformly the surface of the photosensitive drum 1. Next, based on the document image data read in the image reading portion 18, the exposure unit 3 shines a laser beam on the photosensitive drum 1. Thus an electrostatic latent image based on the image data is formed on the surface of the photosensitive drum 1. Then the developing device 4 attaches toner to the electrostatic latent image, and thereby forms a toner image.
From a sheet storage portion 10, a sheet is conveyed toward the image forming portion 6 with predetermined timing via the sheet conveyance passage 11 and a pair of registration rollers 13. The toner image formed on the surface of the photosensitive drum 1 in the image forming portion 6 is then transferred to the sheet by the transfer roller 7. The sheet having the toner image transferred to it is conveyed to a fixing portion 9, where the sheet is heated and pressed. Thus the toner image is fixed to the sheet.
The sheet having passed through the fixing portion 9 is conveyed through the sheet conveyance passage 11 to a pair of discharge rollers 14a or 14b. When an image is formed only on one side of the sheet, the sheet is conveyed by the pair of discharge rollers 14a to be discharged into the sorting device 20 mounted in an in-body discharge space 16.
On the other hand, when images are formed on both sides of the sheet, the leading end of the sheet having passed through the fixing portion 9 is momentarily jutted out from the pair of discharge rollers 14b into the in-body discharge space 16. Next the pair of discharge rollers 14b is rotated reversely so that the sheet is switched back and guided into a reverse conveyance passage 19; thus the sheet is then conveyed, with the image side turned over, once again to the pair of registration rollers 13. Then the next image formed on the surface of the photosensitive drum 1 is transferred by the transfer roller 7 to the side of the sheet on which no image has been formed yet. Thereafter the sheet is conveyed to the fixing portion 9, where the toner image is fixed, and is then discharged by the pair of discharge rollers 14a into the sorting device 20.
As shown in
As shown in
As shown in
In an end part of the base portion 21 at its far side in the sheet width direction (at the rear side of the image forming apparatus 100, i.e., in the arrow-B direction in the illustration), a connection portion 26 is provided upright. The connection portion 26 includes a connector (not illustrated). To the connector are connected cables for feeding electric power and control signals to the sorting device 20. Between the base portion 21 and the tray portion 22, there is arranged a driving mechanism (not illustrated) including a motor and gears for reciprocating the tray portion 22.
Next, with reference to
As shown in
The second inclined portion 29 is located so as to overlap at least part of the sheets P discharged from the pairs of discharge rollers 14a and 14b. Thus the discharged sheets P slide down along the second inclined portion 29 of the tray portion 22. The second upright wall portion 30 makes contact with and thereby aligns the trailing ends of the sheets P that have slid down.
In an end part of the tray portion 22 at one side in the sheet width direction, that is, in an end part of the tray portion 22 at the front side of the in-body discharge space 16, a cutout portion 33 is formed. The cutout portion 33 has the shape of a recess depressed from the sheet stacking surface 32 toward the bottom portion 16a of the in-body discharge space 16. The cutout portion 33 has a tapered shape that extends inward across the tray portion 22 in the sheet width direction while becoming increasingly narrow. That is the width of the cutout portion 33 in the sheet width direction decreases from its end at one side in the sheet width direction inward across the tray portion 22 in the sheet width direction.
The cutout portion 33 has an edge portion 34 that defines the boundary between the sheet stacking surface 32 and the inner surface of the cutout portion 33. The edge portion 34 has the shape of a round surface that connects between the sheet stacking surface 32 and the inner surface of the cutout portion 33 with an arch-shaped curve (see
The edge portion 34 has a downstream edge portion 34a, an upstream edge portion 34b, and a far edge portion 34c. The downstream edge portion 34a forms a downstream part of the edge portion 34 in the sheet discharge direction, and the upstream edge portion 34b forms an upstream part of the edge portion 34 in the same direction. The far edge portion 34c connects together the upstream and downstream edge portions 34b and 34a along the sheet discharge direction. The downstream edge portion 34a extends from an end part of the tray portion 22 in the sheet width direction inward in the sheet width direction, that is, inward across the sheet stacking surface 32 while inclining so as to be increasingly upstream in the sheet discharge direction.
In a plan view in the stacking direction of sheets P (in the direction into the plane of
On the sheet stacking surface 32, a plurality of ribs 35a to 35e are formed. The ribs 35a to 35e project from the sheet stacking surface 32 in the height direction and extend along the sheet discharge direction. The ribs 35a to 35e are arrayed at predetermined intervals in the sheet width direction.
Of the ribs 35a to 35e, the rib 35e located farthest to one side in the sheet width direction is divided into two parts with the cutout portion 33 in between in the sheet discharge direction. Of the two parts of the rib 35e, the one located upstream in the sheet discharge direction is referred to as the upstream rib 36, and the one located downstream in the sheet discharge direction is referred to as the downstream rib 37. The upstream and downstream ribs 36 and 37 are arrayed on a straight line along the sheet discharge direction. That is, on an extension line of the upstream rib 36 extending downstream of it in the sheet discharge direction, the downstream rib 37 is located.
As shown in
Here, the sheet storage portion 10 of the image forming apparatus 100 can accommodate sheets of varying sizes. Of such sheets of varying sizes, those with the maximum dimension in the width direction can be, for example, sheets of A4 size (210 mm×97 mm). To follow is a detailed description of, among others, the positional relationship between the discharge position of sheets P and the relevant parts of the tray portion 22 as observed during discharge of sheets P with the maximum dimension in the width direction in the landscape orientation (the orientation with the longer sides of the sheets P aligned along the sheet width direction).
A sheet P discharged from the image forming apparatus 100 is stacked on the sheet stacking surface 32. Meanwhile, as shown in
The part of the leading end Pa of the sheet P in contact with the rib 35e farthest to one side in the sheet width direction, when it makes contact with the third inclined part 38, runs on a projecting end part of the downstream rib 37 so as to move along the third inclined part 38 away from the sheet stacking surface 32 and the downstream edge portion 34a of the cutout portion 33.
Sorting by the sorting device 20 proceeds as follows. For example, with the tray portion 22 arranged at one side (in the arrow-B′ direction) of the base portion 21 in the sheet width direction, sheets P are discharged from the pair of discharge rollers 14a (or from the pair of discharge rollers 14b) onto the tray portion 22. When a predetermined number of sheets P have been discharged, the tray portion 22 is moved to the other side in the sheet width direction (in the arrow-B direction) and a predetermined number of sheets are discharged. When the predetermined number of sheets P have been discharged, the tray portion 22 is moved back to one side in the sheet width direction (in the arrow-B′ direction). Such operation is repeated, so that bundles of sheets are stacked in units of a predetermined number of sheets on the tray portion 22.
When the tray portion 22 is located in the first shift position SP1, sheets P are discharged so as to overlap the cutout portion 33. In this case, side end parts of the sheets P at one side in the sheet width direction overlap the cutout portion 33. Here, the position at which the sheets P are stacked is father from the cutout portion 33 in the sheet width direction when the tray portion 22 is located in the first shift position SP1 than when the tray portion 22 is located in the second shift position SP2. Accordingly, the cutout portion 33 is arranged such that, when sheets P are discharged in the landscape orientation (i.e., with the long sides of sheets aligned along the sheet width direction), regardless of the position of the tray portion 22 in the sheet width direction, the cutout portion 33 overlaps the discharge position of sheets P.
Thus, with the sorting device 20, regardless of the position of the tray portion 22 in the sheet width direction, the user can, by putting a hand in the cutout portion 33, grab a bundle of sheets P with the maximum dimension in the sheet width direction that was discharged from the image forming apparatus 100.
Moreover, as mentioned above, a gap is left between the sheets P discharged from the image forming apparatus 100 and the sheet stacking surface 32. The gap makes the sheets P less susceptible to the friction and the like that they suffer against the sheet stacking surface 32. Thus the sorting device 20 prevents untidy sorting of sheets P and permits easy retrieval of bundles of sheets P on the tray portion 22.
Moreover, as mentioned above, in an upstream end part of the downstream rib 37 in the sheet discharge direction, the third inclined part 38 is provided. When a sheet P makes contact with the upstream end part of the downstream rib 37, it runs on the top end surface of the downstream rib 37 along the third inclined part 38, and this makes the sheet P being discharged less likely to be caught on the downstream rib 37. Thus the sorting device 20 suppresses untidy sorting of sheets P and permits easy retrieval of bundles of sheets P on the tray portion 22 easily.
Moreover, as mentioned above, the downstream edge portion 34a extends inward across the sheet stacking surface 32 while inclining so as to be increasingly upstream in the sheet discharge direction. Thus, even when the leading end Pa of a sheet P discharged from the image forming apparatus 100 makes contact with the downstream edge portion 34a, the downstream edge portion 34a is less prone to resist the discharge of the sheet P, and the leading end Pa of the sheet P moves along the inclination downstream in the sheet discharge direction. That is, when the sheet P is discharged, it is prevented from being misaligned. Thus it is possible to prevent untidy sorting of sheets P resulting from their being caught on the downstream edge portion 34a, and to permit easy retrieval of bundles of sheets on the tray portion 22.
Moreover, as mentioned above, the third inclined part 38 is located upstream of the middle of the downstream edge portion 34a in the sheet discharge direction. Thus the position at which the leading end Pa of a sheet P makes contact with the third inclined part 38 is located upstream of the middle of the downstream edge portion 34a in the sheet discharge direction. That is, the position at which the leading end Pa of the sheet P moves away from the cutout portion 33 is located upstream of the middle of the downstream edge portion 34a in the sheet discharge direction. This makes the leading end Pa of the sheet P less likely to make contact with the downstream edge portion 34a. In this way, of the ribs 35a to 35e, the rib 35e located farthest to one side in the sheet width direction keeps the sheet P discharged from the image forming apparatus 100 away from the downstream edge portion 34a of the cutout portion 33. Thus the sorting device 20 prevents untidy sorting of sheets P and permits easy retrieval of the sheets P on the tray portion 22.
The present disclosure is not limited by the embodiments described above and allows for any modifications without departure from its spirit. For example, the downstream edge portion 34a does not need to have the shape of an arch-shaped curve: it may instead be so configured as to be composed of a straight part formed in the middle of the downstream edge portion 34a in the sheet width direction and curved parts formed one on each end of the straight part. In that case, the inclination angle θ is formed between the straight part and the imaginary straight line drawn along the sheet width direction. The downstream edge portion 34a may instead be configured to describe a straight line extending from a side end part of the tray portion 22 at one side in the sheet width direction inward in the sheet width direction. Also in that case, the inclination angle θ is formed between the straight part and the imaginary straight line drawn along the sheet width direction.
The effects of the present disclosure will now be described in further detail by way of examples.
Verification experiments were performed to study, with respect to sheets P discharged from the image forming apparatus 100 using the sorting device 20 according to the present disclosure, the misalignment of the sheets P observed when they made contact with the downstream edge portion 34a. Used as the test machine was an image forming apparatus 100, like the one shown in
Plain-paper sheets P of A4 size (210 mm×97 mm) were used, with the sheets P discharged in the landscape orientation (the orientation with the longer sides of sheets P aligned along the sheet width direction). The leading end Pa of a sheet P is the longer side of it located downstream in the sheet discharge direction.
On the sorting device 20 of Comparative Example 1, the inclination angle θ of the downstream edge portion 34a was set at 0° (such that the downstream edge portion 34a is perpendicular to the sheet discharge direction); in Comparative Example 2, the inclination angle θ was set at 10°. In Practical Example 1 according to the present disclosure, the inclination angle θ was set at 20°, and in Practical Example 2 according to the present disclosure, the inclination angle θ was set at 30°. Thus the inclination angle θ was set to vary in 10° steps from Comparative Example 1 to Practical Example 2.
Evaluation was done as follows. When a sheet P in the middle of being discharged moved downward in the sheet discharge direction with the leading end Pa of the sheet P in contact with the downstream edge portion 34a, if the sheet P deformed (if the sheet P became misaligned), this was evaluated as “NG”; if the sheet did not deform (if it did not become misaligned), this was evaluated as “OK”. The results are shown in Table 1.
As shown in Table 1, in Comparative Examples 1 and 2, misalignment of sheets P was observed. By contrast, in Practical Examples 1 and 2, no misalignment of sheets P was observed. From the observation it is seen that, with the inclination angle θ larger than 10°, even when the leading end Pa of a sheet P discharged from the image forming apparatus 100 makes contact with the downstream edge portion 34a of the cutout portion 33, the sheet P can be prevented from being misaligned. It is thus understood that the inclination angle θ of the downstream edge portion 34a should preferably be larger than 10° to suppress misalignment of sheets P during their discharge and to allow the user easy retrieval of bundles of sheets P on the tray portion 22.
The present disclosure finds application in sorting devices that are mounted in an in-body discharge space in image forming apparatuses. Based on the present disclosure, it is possible to provide a sorting device that allows the user easy retrieval of sheets with the maximum dimension in the sheet width direction that are stacked on a tray portion.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2020-132184 | Aug 2020 | JP | national |
