JP3740275B2 - Sheet feeding apparatus and image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile, and more particularly to a sheet feeding apparatus such as a paper deck disposed on a side surface of the apparatus body in order to feed a sheet such as a document or recording paper. is there.
[0002]
[Prior art]
In recent years, in an image forming apparatus such as a copying machine, an improvement in image forming speed is desired in order to obtain a more comfortable operating environment. On the other hand, downsizing of the apparatus is also progressing in order to reduce the installation space.
[0003]
For this reason, it is desired to provide a sheet feeding device capable of supplying a large volume of sheets in order to eliminate the trouble of supplying sheets even in a small-sized image forming apparatus that has been increased in speed.
[0004]
In response to these demands, as a conventional technique, as shown in FIG. 8, a paper deck 2 as a sheet feeding device capable of storing and feeding a large capacity sheet S in a sheet storage C on the side surface of the apparatus main body 1. And the sheet S is fed from the paper deck 2.
[0005]
[Problems to be solved by the invention]
However, in this configuration, the space of the entire apparatus is increased by the amount that the paper deck 2 protrudes laterally from the side of the apparatus.
[0006]
Further, since the sheet S is replenished to the paper deck 2 as shown in FIG. 9 because the front loading is performed after the sheet storage case C is pulled out from the paper deck 2, a working space for this is required, and the installation space is further increased. .
[0007]
Further, in order to process the sheet S jammed between the paper deck 2 and the apparatus main body 1 due to the sheet feeding failure of the paper deck 2, the paper deck 2 is released from the apparatus main body 1 as shown in FIG. Thus, it is movable in a direction away from the apparatus main body 1.
[0008]
However, in this method, since the paper deck 2 is separated from the apparatus main body 1 by the space for processing the jammed sheet S, a substantial work area is required, and the installation space is increased. Furthermore, due to the increase in the maximum weight when the sheets are stacked with the increase in the capacity of the sheet storage case C, the load during the opening / closing operation when the sheets are fully loaded increases. The strength of the support member that supports the sheet storage C on the paper deck 2 is also required.
[0009]
Therefore, it is necessary to reduce the sliding resistance and improve the load resistance of the slide rail of the sheet storage case C, leading to an increase in cost.
[0010]
Further, when the sheet storage C is pulled out when the sheets are full, the paper deck 2 itself tilts due to the movement of the center of gravity, and the alignment between the paper deck 2 and the apparatus main body 1 is out of alignment, which may cause a conveyance failure such as skew. is there.
[0011]
Therefore, it is necessary to increase the strength of the support member for the apparatus main body 1 of the paper deck 2, which also leads to an increase in cost.
[0012]
This tendency becomes more pronounced as the image forming speed of the apparatus main body 1 increases and the capacity of the paper deck 2 increases.
[0013]
The present invention has been made in order to solve the above-described problems of the prior art, and the object of the present invention is to provide a highly reliable sheet feeding that improves space efficiency, sheet replenishment operability, and sheet feeding performance. An apparatus and an image forming apparatus are provided.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, in the present invention, a feeding unit having a feeding unit that feeds stacked sheets one by one at the top of a sheet storage configured to be able to store stacked sheets. wherein the feeding unit is slidably configured in the horizontal direction, characterized in that the feed unit can be retracted to a position that allows the supply of sheets in the sheet storage case.
[0015]
Therefore, when replenishing sheets, it is possible to replenish sheets by simply retracting the feeding unit, there is no need to move the stack of stacked sheets, the installation space of the apparatus can be reduced, and sheet replenishment operability is improved. In addition, it is possible to prevent the conveyance failure caused by the shift of the center of gravity of the storage when the storage of the stacked sheets is moved, and to prevent the sheet feeding performance from deteriorating. In addition, since the sheet can be replenished by sliding the feeding unit when the sheet is replenished, the installation space of the apparatus can be reduced and the sheet replenishment operability can be improved.
[0016]
It is preferable that a guide member that slidably supports the feeding unit is provided.
[0018]
It is preferable that the feeding unit slides in a direction opposite to the sheet feeding direction.
[0019]
As a result, the feeding unit can slide in a space opposite to the sheet feeding direction.
[0020]
It is preferable that the feeding unit slides in a direction perpendicular to the sheet feeding direction.
[0021]
As a result, the feeding unit can slide in a space perpendicular to the sheet feeding direction.
[0022]
The feeding unit preferably includes a feeding roller for feeding a sheet and a pair of separation rollers for separating the sheet.
[0023]
Thereby, when the sheet is replenished, the pair of the feeding roller and the separation roller moves, so that handling becomes easy and maintenance can be easily performed.
[0024]
It is preferable that the pressure contact between the rollers of the separation roller pair is released in conjunction with the movement of the feeding unit to the retracted position.
[0025]
Thereby, the handling of the pair of separation rollers is facilitated, and maintenance can be easily performed.
[0026]
The feeding unit preferably includes the feeding roller and one roller of a separation roller pair.
[0027]
Thereby, since one roller of the feed roller and the separation roller pair moves, the handling becomes easy and the maintenance can be easily performed.
[0028]
It is preferable that the feeding unit moves to the retracted position and the rollers of the separation roller pair are separated from each other.
[0029]
Thereby, the handling of the pair of separation rollers is facilitated, and maintenance can be easily performed.
[0030]
An image forming apparatus according to the present invention includes the above sheet feeding device and feeds a sheet to an image forming unit.
[0031]
Therefore, when the sheet is replenished, the sheet can be replenished by simply retracting the feeding unit, the installation space of the apparatus can be improved, the sheet replenishment operability is improved, and the sheet feeding performance and the apparatus Maintainability can be improved.
[0032]
DETAILED DESCRIPTION OF THE INVENTION
Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. Absent.
[0033]
(First embodiment)
A first embodiment of the present invention will be described below.
[0034]
In general, a sheet feeding device provided in an image forming apparatus such as a copying machine, a printer, or a facsimile uses a separation roller pair composed of a feed roller and a retard roller because the separation performance of the fed sheet is high. Many so-called retard separation type sheet feeding units are employed.
[0035]
FIG. 1 is a configuration diagram showing an image forming apparatus according to the first embodiment having a retard separation type sheet feeding unit. A paper deck 2 as a sheet feeding apparatus is provided on the right side of the apparatus main body 1. It shows the state of wearing. First, the schematic configuration of the image forming apparatus will be described with reference to FIG.
[0036]
The image forming apparatus includes a paper deck 2 as a sheet feeding apparatus in which a large amount of sheets S are stacked and stored on the right side surface of the apparatus main body 1, and a predetermined amount of sheets S are stacked and stored in the lower part of the apparatus main body 1. A plurality of feeding cassettes 3 and 4 are provided.
[0037]
The paper deck 2 for feeding the sheet S and the installation parts of the feeding cassettes 3 and 4 are respectively provided with retard separation type feeding units 5, 6 and 7.
[0038]
As shown in FIG. 3, a feeding unit 5 serving as a feeding unit is provided at an installation site of the sheet paper deck 2. Note that the feeding units 6 and 7 provided at the installation sites of the feeding cassettes 3 and 4 have the same configuration as the feeding unit 5.
[0039]
As shown in FIG. 3, the feeding unit 5 includes a feeding roller (pickup roller) 23 that rotates and feeds the uppermost sheet of the sheets S stacked on the lifter plate 22 of the paper deck 2 in the direction of the arrow. In the case of a plurality of sheets, the sheet S fed by the feeding roller 23 is separated one by one and conveyed downstream, and a separation roller pair on the downstream side of the separation roller pair 25 in the sheet conveying direction. And a sheet detection sensor (sheet detection means) 26 that detects the sheet S that has passed through 25.
[0040]
Note that the sheet detection sensor 26 has a function of detecting a jam of the sheet S and a remaining state of the separation roller pair 25 in addition to confirming the feeding state of the sheet S.
[0041]
A sheet detection sensor is provided in the main part of the sheet conveyance path of the image forming apparatus in order to detect a jam everywhere. When a jam detection signal is input from these sheet detection sensors, the image forming apparatus stops its operation. It is like that.
[0042]
The illustrated sheet detection sensor 26 includes a detection lever 29 that can rotate around a support shaft 27 and an optical sensor 30 that outputs a detection signal when the detection lever 29 blocks light.
[0043]
The separation roller pair 25 includes a feed roller 31 that rotates in a direction in which the sheet S is conveyed (arrow direction), and a retard that rotates in a direction in which the sheet S is returned by contacting the feed roller 31 with a predetermined pressure (arrow direction). And roller 32.
[0044]
When only one sheet S fed by the feeding roller 23 enters the nip portion of the separation roller pair 25, the retard roller 32 is idled and is driven by the feed roller 31 to convey the sheet S downstream. To do.
[0045]
When a plurality of sheets S fed by the feeding roller 23 enter, the retard roller 32 rotates in the direction of the arrow, so that the sheets S other than the uppermost sheet S are returned to the retard roller 32, and the feed roller Only one uppermost sheet S is separated by 31 and conveyed downstream.
[0046]
Rotational power from a drive source (not shown) is transmitted to the feed roller 31 and the retard roller 32 of the separating roller pair 25 that function in this way.
[0047]
That is, as shown in FIG. 2, the rotational power of the drive source is transmitted to the roller shaft 36 of the feed roller 31 via the electromagnetic clutch 35. The rotational power transmitted to the roller shaft 36 of the feed roller 31 is transmitted to the relay shaft 39 via the relay gear 37, and further transmitted to the roller shaft 42 of the retard roller 32 via the torque limiter 40 and the coupling 41. Yes.
[0048]
The electromagnetic clutch 35 is disposed at one end of the roller shaft 36, and the roller shaft 36 is coupled to the rotor portion 43. The armature portion 45 of the electromagnetic clutch 35 is attached to the roller shaft 36 so as to freely rotate. When a predetermined voltage is applied to the electromagnetic clutch 35, it is attracted to the rotor portion 43 and integrated with the rotor portion 43. The rotational force of the drive source is transmitted to this amateur part 45.
[0049]
Therefore, when a predetermined voltage is applied to the electromagnetic clutch 35, the rotational power of the drive source is transmitted to the roller shaft 36, and the feed roller 31 rotates in the direction in which the sheet S is conveyed (arrow direction). The electromagnetic clutch 35 is ON / OFF controlled according to the feeding timing.
[0050]
The rotation of the roller shaft 36 is transmitted to the relay shaft 39 via the relay gear 37 and further transmitted to the roller shaft 42 via the torque limiter 40 and the coupling 41, so that the retard roller 32 rotates the feed roller 31. Synchronously, the sheet S is rotated in the direction of returning (arrow direction).
[0051]
However, the body 46 of the torque limiter 40 is connected to the relay shaft 39 via a friction member 47 such as magnetic powder, and the coupling 41 is connected to the body 46 of the torque limiter 40. When a torque of a predetermined value T or more is applied to the portion 46, a slip state is generated between the body portion 46 and the relay shaft 39. As a result, the retard roller 32 is idled and rotated by the feed roller 31.
[0052]
Here, the friction coefficient between the feed roller 31 and the sheet S and between the retard roller 32 and the sheet S is μ1, the friction coefficient between the sheet S and the sheet S is μ2, and the feed roller 31 and the retard roller 32 If the radius is R and the contact force between the feed roller 31 and the retard roller 32 is P, and μ1, μ2, P, and T are set so that μ1> μ2, T / μ1R <P <T / μ2R, the separation roller The retard roller 32 functions as described above when one sheet S enters the nip portion of the pair 25 and when a plurality of sheets S enter.
[0053]
By the way, when the image forming apparatus stops the image forming operation by the input of the jam detection signal, the position of the sheet S remaining in the apparatus main body 1 is displayed on the display unit on the operation panel, the indicator unit on the electric board, or the like. Jam processing is easy to perform.
[0054]
When the sheet S fed from the paper deck 2 remains (or jams) in the separation roller pair 25 portion of the feeding unit 5 due to the stop of the image forming operation described above, the state is detected by the sheet detection sensor 26. Displayed on the display unit of the operation panel.
[0055]
As shown in FIG. 3, when a jam detection signal is input from any of the sheet detection sensors in the apparatus main body 1, the lifter plate 22 of the paper deck 2 moves the distance L from the feeding roller 23 to the uppermost sheet S position. It descends to the lowered position to form a predetermined space in the paper deck 2 portion.
[0056]
Accordingly, the sheet S remaining in the separation roller pair 25 portion can be easily removed by inserting a hand in the direction of the arrow.
[0057]
In this way, the sheet S remaining on the separation roller pair 25 portion is processed. However, when the jammed sheet S is processed, the lifter plate 22 is raised by the jam recovery signal, and the uppermost sheet S is fed by the feeding roller 23. Return to the feeding system in contact with a predetermined pressure.
[0058]
As shown in FIG. 1, when the sheets S in the paper deck 2 and the feeding cassettes 3 and 4 are fed by the feeding units 5, 6, and 7, the registration roller pair that stops rotating first. The skewed state is corrected here.
[0059]
Next, the photosensitive drum 9 is sent between the photosensitive drum 9 and the transfer charger 10 by the registration roller pair 8 that rotates in synchronization with the latent image formed on the photosensitive drum 9. The upper toner image is transferred to form an image.
[0060]
Thereafter, the sheet S is sent to the fixing device (fixing roller pair) 12 by the conveying belt 11, and a fixing process for fixing the transferred toner image on the sheet surface is performed.
[0061]
The image forming apparatus includes a double-sided image forming mode for forming a double-sided image on the sheet S and a multiple image forming mode for performing multiple image formation. The paper is discharged onto a discharge tray 15 outside the apparatus by the discharge roller pair 13 and the outer discharge roller pair 14.
[0062]
In the double-sided image forming mode and the multiple image forming mode, the paper is temporarily stacked and stored on the intermediate tray 17 via the refeed path 16 by the inner discharge roller pair 13 or the outer discharge roller pair 14.
[0063]
Next, sheet replenishment with the paper deck 2 according to the present embodiment will be described.
[0064]
As shown in FIG. 4, when the sheet is replenished to the paper deck 2, the feeding unit opening / closing handle 20 a is rotated to release the association between the feeding unit 20 including the feeding unit 5 and the sheet storage case 19. Then, the feeding unit 20 supported by the slide rail 20b as the guide member is slid from the feeding position to the retracted position in the direction of arrow A in the direction opposite to the sheet feeding direction.
[0065]
At this time, the press contact between the feed roller 31 of the separation roller pair and the retard roller 32 is released by a release member (not shown) interlocked by a link mechanism (not shown) by the operation of the feeding unit opening / closing handle 20a, and the lifter plate 22 is not shown. By driving the lifter motor, the sheet supply position sensor 21 provided in the sheet storage case 19 is lowered to the sheet supply position. In this state, the user can replenish sheets from the upper part of the sheet storage case 19.
[0066]
Even when a jam occurs in which the sheet S stays between the paper deck 2 and the apparatus main body 1, the feeding roller opening / closing handle 20a is rotated to release the pressure roller 31 and the retard roller 32 by the interlocking release member. Then, the feeding unit 20 supported by the slide rail 20b is slid to the retracted position in the direction of arrow A in the figure, and the jammed sheet is removed.
[0067]
By making the feeding unit 20 movable in this way, it becomes possible to prevent deterioration in operability of sheet replenishment and sheet feeding performance. At the same time, it is possible to reduce the work space required for jam processing and sheet supply between the paper deck 2 and the apparatus main body 1.
[0068]
Further, since the feeding unit 5 itself slides, the handling of the feeding roller 23 and the separation roller pair 25 is facilitated, and maintenance can be easily performed.
[0069]
(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG.
[0070]
In the first embodiment, the feeding roller 23, the feed roller 31, and the retard roller 32 that constitute the feeding unit 5 are all provided on the feeding unit 20 side. However, in the second embodiment, The feed roller 123 and the feed roller 131 as one roller of the separation roller pair are provided on the feed unit 120 side and move with the slide of the feed unit 120, but the retard roller as the other roller of the separation roller pair 132 is supported on the sheet storage case 19 side and does not move even when the feeding unit 120 is slid.
[0071]
Since other configurations and operations are the same as those in the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.
[0072]
Thereby, the pressure roller of the feed roller 131 and the retard roller 132 is released by the sliding operation of the feeding unit 120.
[0073]
As a result, not only the same effects as in the first embodiment can be obtained, but also a release member for releasing the pressure contact between the feed roller 131 and the retard roller 132 is not required, and the apparatus can be simplified and the retard roller 132 can be simplified. Therefore, maintenance work such as replacement of the retard roller 132 becomes easier.
[0074]
(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG.
[0075]
In the first embodiment, the feeding unit 20 is configured to slide in the direction of arrow A in the drawing, but in the third embodiment, feeding in the direction of arrow B in the drawing is perpendicular to the sheet feeding direction. The unit 220 is configured to slide.
[0076]
Since other configurations and operations are the same as those in the first embodiment, the same components are denoted by the same reference numerals and description thereof is omitted.
[0077]
Even with such a configuration, the same effect as in the first embodiment can be obtained, and when the feeding unit 220 of the paper deck 2 cannot slide in the direction of the arrow A because there is no work space or the like. Even in such a case, the feeding unit 320 can be slid in the direction of arrow B in the figure.
[0078]
(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to FIG.
[0079]
In the second embodiment, the feeding unit 120 is configured to slide in the direction of arrow A in the figure, but in the fourth embodiment, the feeding unit 320 is configured to slide in the direction of arrow B in the figure. .
[0080]
Since other configurations and operations are the same as those of the second embodiment, the same components are denoted by the same reference numerals, and description thereof is omitted.
[0081]
Even with such a configuration, the same effect as in the second embodiment can be obtained, and when the feeding unit 320 of the paper deck 2 cannot slide in the direction of the arrow A because there is no work space or the like. Even in such a case, the feeding unit 320 can be slid in the direction of arrow B in the figure.
[0082]
【The invention's effect】
In the sheet feeding apparatus according to the present invention, the feeding unit can be retracted to a position where the sheets can be replenished. Therefore, when sheets are replenished, it is not necessary to move the stack of stacked sheets, and the installation space of the apparatus is reduced. In addition, the sheet replenishment operability can be improved, and the conveyance failure caused by the deviation of the center of gravity of the stacked sheet storage can be prevented to prevent the sheet feeding performance from deteriorating.
[0083]
By providing a guide member that slidably supports the feeding unit, the feeding unit can be slid during sheet replenishment to reduce the installation space of the apparatus and improve sheet replenishment operability. Can do.
[0084]
The feeding unit can slide in a space opposite to the sheet feeding direction, or can slide in a space perpendicular to the sheet feeding direction.
[0085]
Since the feeding unit has a feeding roller that feeds the sheet and a separation roller pair that separates the sheet, the feeding unit moves, so that maintenance can be easily performed.
[0086]
Further, when the pressure contact between the rollers of the separation roller pair is released in conjunction with the movement to the retracted position, the maintenance of the separation roller pair can be performed more easily.
[0087]
Alternatively, the feeding unit moves while having the feeding roller and one roller of the separation roller pair, so that maintenance can be easily performed.
[0088]
Further, when the rollers of the separation roller pair are separated from each other while being moved to the retracted position, the maintenance of the separation roller pair can be performed more easily.
[0089]
The image forming apparatus of the present invention includes the above sheet feeding device and feeds the sheet to the image forming unit. Therefore, when the sheet is replenished, the installation space of the apparatus can be made efficient and the sheet replenishment operability can be improved. In addition, the sheet feeding performance and the maintainability of the apparatus can be improved.
[Brief description of the drawings]
FIG. 1 is a configuration diagram illustrating an image forming apparatus according to a first embodiment.
FIG. 2 is a perspective view showing a separation roller pair according to the first embodiment.
FIG. 3 is a cross-sectional view of a main part showing the paper deck according to the first embodiment.
FIG. 4 is a perspective view showing a paper deck according to the first embodiment.
FIG. 5 is a perspective view showing a paper deck according to a second embodiment.
FIG. 6 is a perspective view showing a paper deck according to a third embodiment.
FIG. 7 is a perspective view showing a paper deck according to a fourth embodiment.
FIG. 8 is a block diagram showing an image forming apparatus according to the prior art.
FIG. 9 is a perspective view showing an image forming apparatus according to the prior art.
FIG. 10 is a perspective view showing an image forming apparatus according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Paper deck 5 Feeding part 19 Sheet storage 20 Feeding unit 20a Feeding unit opening / closing handle 20b Slide rail 21 Sheet replenishment position sensor 22 Lifter plate 23 Feeding roller 25 Separating roller pair 26 Sheet detection sensor 31 Feed roller 32 retard roller 120 feeding unit 120a feeding unit opening / closing handle 120b slide rail 123 feeding roller 131 feeding roller 132 retard roller 220 feeding unit 220a feeding unit opening / closing handle 220b slide rail 320 feeding unit 320a feeding unit opening / closing handle 320b Slide rail

Claims (9)

Provided with a feeding unit having a feeding unit that feeds the stacked sheets one by one at the top of a sheet storage configured to be able to store stacked sheets,
The sheet feeding apparatus, wherein the feeding unit is configured to be slidable in a horizontal direction, and the feeding unit can be retracted to a position where sheets can be supplied to the sheet storage.   The sheet feeding apparatus according to claim 1, further comprising a guide member that slidably supports the feeding unit.   The sheet feeding apparatus according to claim 2, wherein the feeding unit slides in a direction opposite to a sheet feeding direction.   The sheet feeding apparatus according to claim 2, wherein the feeding unit slides in a direction perpendicular to a sheet feeding direction.   5. The sheet feeding apparatus according to claim 1, wherein the feeding unit includes a feeding roller that feeds a sheet and a pair of separation rollers that separates the sheet.   The sheet feeding apparatus according to claim 5, wherein the pressure contact between the rollers of the separation roller pair is released in conjunction with the withdrawal of the feeding unit.   5. The sheet feeding according to claim 1, wherein the feeding unit includes a feeding roller that feeds a sheet and one roller of a separation roller pair that separates the sheet. apparatus.   8. The sheet feeding apparatus according to claim 7, wherein the feeding unit retracts and the rollers of the separation roller pair are separated from each other.   An image forming apparatus comprising the sheet feeding device according to claim 1, wherein the sheet is fed to an image forming unit.

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