JPH0840584A - Sheet feeding device and image forming device provided with this sheet feeding device - Google Patents

Abstract

PURPOSE:To enable the optional setting of the size and capacity of sheets to be fed by a sheet feeding device according to the demand of a user. CONSTITUTION:A sheet stacking-feeding means 8 freely elevated and formed of a sheet stacking base 7 and a second sheet feeding means 6 is removably disposed between a sheet stacking base 2 that can be elevated and can stack a large capacity of sheets, and a first sheet feeding means 13 that can feed the stacked sheets S. A conveyor belt 5 is provided opposedly to the stacked sheets. The sheets from the sheet stacking base 2 is fed by the second sheet feeding means 6, and the sheets on the sheet stacking base 7 are fed by the first sheet feeding means 13. The fed sheets are conveyed by the conveyor belt 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding device in an image forming apparatus such as a copying machine, and more particularly to a sheet feeding device capable of stacking a large amount of sheets and feeding various sizes of sheets. Regarding the sending device.

[0002]

2. Description of the Related Art Conventionally, when an image is formed by a copying machine,
2. Description of the Related Art A copier capable of feeding sheets of various sizes, or a copier capable of feeding a specific size to a large capacity is provided. FIG. 6 shows a copying machine capable of feeding sheets of various sizes. In the figure, the copying machine body 4 of the copying machine 1
A photosensitive drum (image forming portion) 43 is provided in the area 0. A document placed on the document table 41 is scanned by the optical system 42, and the document image is projected onto the photosensitive drum 43, whereby a latent image is formed on the photosensitive drum 43. By developing this, a toner image is formed on the photosensitive drum 43.

Further, in the main body 40 of the copying machine, a plurality of sheet feeding cassettes 7 respectively accommodating sheets S of various sizes are provided.
1, 72, 73 are detachably mounted, and the sheet S is fed to the photosensitive drum 43 by the sheet feeding rollers 75, 76, 77 provided respectively, and the toner image is transferred. The sheet S after the transfer of the toner image is conveyed to the fixing device by the conveying unit 52 and fixed, and is ejected to the outside of the apparatus by the ejection roller 56.

The copying machine 1 shown in FIG. 7 is equipped with a paper feed deck 77 that accommodates a large number of frequently used size sheets. This paper feed deck 77 is a sheet stacking table 2 that stacks sheets and can be raised and lowered, a paper feed roller 79 that feeds the uppermost sheet S, and a separation / conveyance that separates and conveys the fed sheets S. A roller 80 and the like are provided. The sheet S fed from the paper feed deck 77 has a toner image transferred from the photosensitive drum 43 in the same manner as in the copying machine 1 of FIG.

[0005]

However, the above-mentioned conventional example has the following problems.

A large number of paper feed cassettes 71, 7 shown in FIG.
In the copying machine 1 having the Nos. 2 and 73, since the capacity of the sheets S of each size is small, the copy job had to be temporarily stopped to replenish the sheets each time the sheets S were exhausted. There is a problem that productivity is significantly reduced.

Further, in the large-capacity sheet feeding apparatus shown in FIG. 7, a sheet replenishment problem does not occur for a sheet of a certain specific size, but the type of the size of the sheet S is limited, so that the user can There is a problem that it cannot respond to the diversification of the needs of

In any case, it is difficult to satisfy the sheet size and the capacity required by the needs of a plurality of users in one copying machine 1 at the same time.

It is an object of the present invention to provide a sheet feeding device in which the size and capacity of a sheet to be fed can be arbitrarily set according to a user's request, and an image forming apparatus including the sheet feeding device. is there.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and includes a first sheet stacking means (2) for stacking sheets, which can be moved up and down, and the sheet stacking means (2). A first sheet feeding means (13) arranged above, for separating and feeding the stacked sheets (S).
And a second sheet stacking means (7) for feeding sheets, and a second sheet provided below the sheet stacking means (7) and capable of separating and feeding the lower sheet (S) At least one sheet stacking / feeding means (8) obtained by unitizing the feeding means (6), and the first sheet stacking means (2) and the second sheet stacking means (7) are respectively moved up and down. A plurality of raising / lowering driving means (9), the first sheet stacking means (2) and the second sheet stacking means (7)
A transporting means (5) for transporting the sheet (S) fed by.

The sheet stacking / feeding means (8)
Is detachable from the lifting drive means (9).

Further, the first sheet stacking means is capable of stacking a large amount of sheets.

The sheet stacking / feeding means (8)
Is a sheet feeding drive means (63) for driving a second sheet feeding means (6) provided in the sheet stacking / feeding means (8).
It is characterized by having.

A sheet surface detecting means (61) for detecting the upper surfaces of the sheets (S) stacked on the first sheet stacking means (2) and the second sheet stacking means (7), respectively.
And the drive operation of the elevation drive means (9) is controlled by detecting the seat surface by the seat surface detection means (61).

[0015]

According to the above configuration, the sheet (S) is fed from either the first sheet stacking means (2) or the second sheet stacking means (7) based on the selected sheet size. .

When the sheets (S) on the first sheet stacking means (2) are fed, the stacked sheets (S) are the second sheet feeding means of the sheet stacking / feeding means (8). By (6), the sheets are separated and fed one by one. When feeding the upper sheet (S) of the second sheet stacking means (7), the sheets (S) are separated and fed one by one by the first sheet feeding means (13). . The fed sheet (S) is further conveyed by the conveying means (5).

Thus, for example, a large-capacity sheet (S) is stacked on the first sheet stacking means (2), and a sheet (S) of a size requested by the user is placed on the sheet stacking / feeding means (8) above it. By stacking S), it becomes possible to feed a large capacity sheet (S) and also feed a desired size sheet (S).

A large-capacity sheet (S) that is frequently used is stacked on the first sheet stacking means (2), and a sheet (S) of any desired size (S) is stacked on the sheet. It is loaded on the feeding means (8).

Further, if another sheet stacking / feeding means (8) is additionally attached to the lifting drive means (9), small-capacity, multi-size sheets (S) can be fed. You can

When the number of stacked sheets (S) is reduced by feeding the sheets (S), the position of the uppermost sheet (S) is detected by the sheet surface detecting means (61). As a result, the elevating drive means (9) is driven to move the first sheet stacking means (2) or the second sheet stacking means (7) to a predetermined position.

The reference numerals in parentheses are shown for reference to the drawings and do not limit the structure of the present invention.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the same parts as those shown in FIG. 6 are designated by the same reference numerals. The sheets S stored in the paper feed cassettes 45 and 46 in the copying machine main body 40 are fed by the paper feed rollers 47, and the separation / conveyance rollers 4 on the downstream side.
It is conveyed to the photosensitive drum 43 by 9.

A sheet stacking base (first sheet stacking means) 2 capable of stacking a large amount of sheets S is arranged in the main body 40 of the copying machine so as to be vertically movable as will be described later. A supporting member 14 is fixedly installed above the sheet stacking table 2, and a first sheet feeding means 13 is arranged below the supporting member 14. The first sheet feeding means 1
Reference numeral 3 denotes a sheet feeding roller 13a located below the sheet feeding roller 13a for feeding a sheet and a separating / conveying roller pair 13b for separating / conveying the fed sheet S.

A sheet stacking / feeding means 8 is arranged between the first sheet feeding means 13 and the sheet stacking base 2 so as to be vertically movable as will be described later. This sheet stack
The feeding unit 8 is a sheet stacking platform (second sheet stacker) on which the sheets S are stacked.
Sheet stacking means 7) and a second sheet feeding means 6 disposed below the sheet stacking means 7).

The second sheet feeding means 6 comprises a sheet feeding roller 6a for feeding the sheet S on the sheet stacking table 2 and a separating / conveying roller pair 6b for separating / conveying the structured sheet S. ing.

The sheet stacking table 7 of the sheet stacking / feeding means 8 is provided with a sheet feeding motor 63 for driving the second sheet feeding means 6. Since the sheet feeding motor 63 for driving the second sheet feeding means 6 is provided on the sheet stacking table 7, it is not necessary to provide a sheet feeding driving means for driving the sheet stacking table 7 on the copying machine main body 40 side. Thus, it is possible to prevent the structure of the copying machine main body 40 from becoming complicated.

The sheet S on the sheet stacking table 2 and the sheet S on the sheet stacking table 7 are opposed to each other, that is, the first sheet feeding means 13 and the sheet stacking table 2 descending to the lowest position. A conveyor belt (conveying means) 5 for conveying the fed sheet S is arranged at a position extending between the spaces. Thereby, the second sheet feeding means 6 can feed the sheet S at an arbitrary position.

The conveyor belt 5 is stretched around a driving roller 17 and a driven roller to rotate counterclockwise in the drawing. The transport roller 20 is pressed against the drive roller 17 via the transport belt 5, and the sheet S transported by the transport belt 5 is further transferred to the photosensitive drum 43.
Transport to Reference numeral 19 denotes a guide plate that guides the sheet S between the drive roller 17 and the transport roller 20.

Further, an air suction means 4 is arranged between the conveyor belts 5. The sheet S fed by the second sheet feeding means 6 or the first sheet feeding means 13 is conveyed by the conveyance belt by the air suction force obtained by discharging the air in the air suction means 4 by the fan 3. 5 is sucked and conveyed.

2 to 4 show the drive units of the sheet stacking table 2 and the sheet stacking table 7, FIG. 2 is a perspective view, FIG. 3 is a front view, and FIG. 4 is a side view.

In the figure, the pair of feed screws (elevation drive means) are driven by an elevation motor (elevation drive means) 62 controlled by the control means 60. Each of the holding members 10 mounted on the control means 62 has a notch in which the sheet stacking table 2 is detachably mounted, and is moved up and down by the forward and reverse rotation of the holding member 10.

The sheet stacking table 2 has a sheet S at the front thereof.
A slit 2a for attaching a front end regulating member 12 (see FIG. 4) for regulating the front end portion of the sheet S is formed.
Two pairs of slits 2b and 2c (see FIG. 3) for detachably mounting (see FIG. 3) are provided.

In addition to the feed screw 9A, the sheet stacking table 7
Is further provided with a feed screw (elevation drive means) 9B for driving by an elevation motor 62 different from the control means 62 for the sheet stacking table 2. The sheet stacking base 7 is detachably mounted on the holding member 10 mounted on the feed screw 9B similarly to the sheet stacking base 2. The sheet stacking base 7 also has a slit 7a for mounting the leading edge regulating member 12 and two pairs of slits 7b, 7c for mounting the leading edge regulating member 12, respectively.

As described above, the sheet stacking table 2 and the sheet stacking table 7 are raised and lowered by the dedicated feed screws 9A and 9B, respectively, and the feed screws 9A and 9B are also driven by the dedicated lifting motors 62, respectively. Has become.

A sheet detecting sensor (sheet detecting means) 61 for detecting the uppermost sheet surface of the sheets S stacked on the sheet stacking base 7 is provided below the support member 14 (on both sides). It is provided. Similarly, a similar sheet detection sensor 61 is provided below the sheet stacking table 7 to detect the uppermost sheet surface of the sheets S stacked on the sheet stacking table 2.

The sheet detection sensor 61 of the support member 14 is
When the sheet stacking table 7 moves up and the distance between the sheet and the supporting member 14 reaches a predetermined distance, this is detected. Based on this detection, the control means 60 stops the drive of the lifting motor 62 and stops the lifting of the sheet stacking base 7.

Similarly, when the sheet detection sensor 61 of the sheet stacking base 7 detects the sheet surface of the sheet S on the sheet stacking base 2, the control means 60 stops the lift motor 62 to cause the sheet stacking base 7 to move. Stop the descending motion.

The feeding operation of the sheet S by the sheet feeding device configured as described above will be described.

The feeding of the sheet S by the above-mentioned sheet feeding device provided outside the main body 40 of the copying machine is usually performed for the large-capacity sheet S loaded on the sheet loading table 2. In this case, the sheet stacking / feeding means 8 is in a state of being removed from the feed screw 9B. Then, the sheets S on the sheet stacking table 2 are fed one by one by the first sheet feeding means 13 of the support member 14.

The fed sheet S is conveyed by the conveyor belt 5, and further the driving roller 17 and the conveyor roller 20.
Are conveyed to the photosensitive drum 43. This sheet S is
The toner image is transferred by the transfer charger 50, and the conveying unit 5
Then, the toner image is fixed to the fixing device 53, and after the toner image is fixed, the toner image is discharged to the outside by the inner discharge roller 55 and the discharge roller 56.

When the user wants to feed a sheet S having a size different from the large-capacity sheet S loaded on the sheet loading table 2, as shown in FIG. 1, the sheet loading / feeding is performed with respect to the feed screw 9B. The feeding unit 8 is mounted and the sheets S having a desired size are stacked.

When the user selects the sheet S of the sheet stacking / feeding means 8 at the time of feeding the sheet S, the feed screw 9B operates to raise the sheet stacking / feeding means 8.
When the sheet stacking / feeding unit 8 moves up to a predetermined position, the sheet detection sensor 61 provided on the support member 14 detects the sheet surface of the sheet S. Based on this detection, the control means 60 controls the lifting motor 62 to stop, and the lowering of the sheet stacking table 7 by the feed screw 9B stops.

With the sheet stacking / feeding means 8 stopped at a predetermined position, the first sheet feeding means 13 of the support member 14 is provided.
Is activated, the sheets S stacked on the sheet stacking base 7 are
Is fed and conveyed to the photosensitive drum 43 by the conveyor belt 5, the driving roller 17, and the conveyor roller 20. The sheet S has the same image formation as the sheet S described above and is discharged to the outside of the machine. When the sheet surface of the sheet S on the sheet stacking table 7 becomes low due to the feeding of the sheet S, the sheet detection sensor 61 detects this and slightly raises the sheet stacking table 7 to a predetermined position.

In the above feeding operation, the case where the supporting member 14 carries out the fixed state data is described, but even if the supporting member 14 is moved up and down while the sheet stacking / feeding means 8 is stopped, The sheets S on the sheet stacking base 7 can be fed.

Next, when the sheet stacking / feeding means 8 is mounted on the feed screw 9B and the sheet S is fed from the sheet stacking base 2, the sheet stacking / feeding means is used. When the sheet detecting sensor 61 of the sheet stacking base 7 detects the sheet surface of the sheet S on the sheet stacking base 2, the operation of the feed screw 9A is stopped, and the sheet stacking / feeding unit 8 is lowered. 8 stops in place.

In this state, the sheet S on the sheet stacking table 2 is
Is set by the second sheet feeding means 6 of the sheet stacking table 7.
The photosensitive drum 4 is fed by the operation of feeding the sheets one by one, carrying the carrying belt 5 to the driving roller 17, the carrying roller 20, and the like.
Then, the image is formed in the same manner as described above.
In this case, when the sheet S on the sheet stacking table 2 is gradually reduced by the sheet feeding operation and is detected by the sheet detection sensor 61, the sheet stacking / feeding means 8 descends,
When the sheet detection sensor 61 detects the sheet surface, the sheet stacking / feeding unit 8 stops at a predetermined position.

When the sheet S is fed from the sheet stacking table 2 with the sheet stacking / feeding means 8 attached to the sheet feeding device, the sheet stacking / feeding is performed in the above-described feeding operation. Although the example in which the feeding unit 8 is lowered and the sheet stacking table 2 is stopped has been described, the present invention is not limited to this, and the sheet stacking table 2 may be raised while the sheet stacking / feeding unit 8 is stopped, for example. The same feeding operation can be performed.

As described above, the sheet stacking / feeding means 8 capable of stacking sheets S of various sizes is provided for the sheet feeding device capable of feeding the large capacity sheets S stacked on the sheet stacking table 2. By being detachably provided, it is possible to feed a large-capacity sheet S and also to feed a sheet S of a size desired by the user, thereby realizing large-capacity feeding and multi-size feeding. it can.

In the above-described embodiment, the case where the number of the sheet stacking / feeding means 8 which can be detachably attached to the sheet feeding device is one has been described. You can also

FIG. 5 shows a copying machine body provided with this type of sheet feeding device. In the figure, a plurality of sheet stacking / feeding means 8 are detachably arranged between the first sheet feeding means 13 and the sheet stacking base 2 below the first sheet feeding means 13. The respective sheet stacking / feeding means 8 are
Each is attached to and detached from a dedicated feed screw 9B.
The lifting motors 62 for driving the feed screws 9B are also provided for exclusive use.

As described above, by arranging a plurality of sheet stacking / feeding means 8 with respect to the sheet feeding device, a large capacity sheet S can be fed and a desired size different from this large capacity sheet can be fed. Various types of sheets S can be fed.

[0053]

As described above, according to the present invention,
A second sheet stacking unit capable of stacking sheets and a lower sheet are fed between the first sheet feeding unit and a first sheet stacking unit provided to be movable up and down in one of a plurality of lifting drive units. Since the sheet stacking / feeding means including the possible second sheet feeding means can be arranged, for example, a large-capacity sheet is stacked on the first sheet stacking means and the second sheet stacking / feeding means is provided. Sheets of a desired size can be stacked on this sheet stacking means. That is, both the size and the capacity of the sheet to be fed can be set randomly, and it becomes possible to meet the diversifying demands of the user.

Further, since the sheet stacking / feeding means is detachably attached to the elevating / lowering means, it is possible to arbitrarily feed a sheet of a desired size desired by the user.

Further, since the large-capacity sheets can be stacked on the first sheet stacking means, it is possible to feed sheets of a desired size, but the large-capacity sheets that are frequently used are used. Can also be fed, and can meet the diversifying needs of users.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of a copying machine main body including a sheet feeding device according to an embodiment of the present invention.

FIG. 2 is a perspective view of the sheet stacking table and the feed screw portion of the sheet feeding device.

FIG. 3 is a front view of the sheet stacking table and the feed screw portion of the sheet feeding device.

FIG. 4 is a side view of the sheet stacking table and the feed screw portion of the sheet feeding device.

FIG. 5 similarly has a plurality of sheet stacking / feeding means. Longitudinal front view of copying machine body with advantages

FIG. 6 is a vertical sectional front view of a copying machine body including a conventional sheet feeding device.

FIG. 7 is a vertical sectional front view of a copying machine main body including another conventional sheet feeding device.

[Explanation of symbols]

S sheet 1 copy machine (image forming apparatus) 2 sheet stacking platform (first sheet stacking unit) 4 air suction unit 5 transport belt (transporting unit) 6 second sheet feeding unit 7 sheet stacking platform (second sheet) Stacking means) 8 Sheet stacking / feeding means 9A, 9B Feed screw (elevating drive means) 13 First sheet feeding means 14 Support member 40 Copier main body 43 Photosensitive drum (image forming means) 60 Control means 61 Sheet detection sensor (Sheet Surface Detecting Means) 62 Elevating Motor for Feed Screws 9A, 9B 63 Feed Motor for Driving Second Sheet Feeding Means 6

Claims (8)

[Claims] 1. A first sheet stacking unit for stacking sheets, which is vertically movable, and a first sheet feeding unit disposed above the sheet stacking unit for separating and feeding the stacked sheets. And a second sheet stacking means for stacking sheets, and a second sheet feeding means provided under the sheet stacking means and capable of separating and feeding lower sheets, as one unit. At least one sheet stacking / feeding unit, a plurality of lifting drive units for respectively lifting and lowering the first sheet stacking unit and the second sheet stacking unit, the first sheet stacking unit and the second sheet stacking unit A sheet feeding device for feeding the sheet fed by the sheet feeding device. 2. The sheet stacking / feeding means is detachable from the driving means.
The sheet feeding device described in. 3. The sheet feeding apparatus according to claim 1, wherein the first sheet stacking unit can stack a large amount of sheets. 4. The sheet stacking / feeding means comprises a sheet feeding drive means for driving a second sheet feeding means provided in the sheet stacking / feeding means.
The sheet feeding device according to any one of items 1 to 3. 5. A sheet surface detecting means for detecting an upper surface of sheets stacked on each of the first sheet stacking means and the second sheet stacking means is provided, and the sheet surface is detected by the sheet surface detecting means. 4. The sheet feeding device according to claim 1, wherein a driving operation of the lifting drive means is controlled. 6. The sheet feeding apparatus according to claim 1, wherein the conveying unit is a conveying belt that is arranged to face a front end portion of the stacked sheets. 7. The conveyor belt has air suction means for adsorbing the sheet fed from the first sheet feeding means or the second sheet feeding means to the conveyor belt. 6. The sheet feeding device according to item 6. 8. An image forming apparatus comprising: the sheet feeding device according to claim 1; and an image forming unit that forms an image on a sheet fed by the sheet feeding device. apparatus.