JPH0840582A - Sheet feeding device and image forming device provided with this sheet feeding device - Google Patents

Abstract

PURPOSE:To enable the feeding of sheets without the generation of double feed by supporting the rear end parts of partial sheets out of sheets to be stacked by a sheet supporting means positioned over a sheet stacking means. CONSTITUTION:In the case of sheets carried into a sheet stacking means 5 being the specified quantity or less, a sheet supporting means 4a is positioned in a retreat position, and the whole of the sheets is stacked on the sheet stacking means 5. When the carried-in sheets exceed the specified quantity, the sheet supporting means 4a moves into an operating position from the reteat position, and the rear end parts of the sheets carried in by a sheet carry-in means 108 are stacked on the sheet supporting means 4a. At the time of feeding the sheets, the rear end parts of the sheets are supported by the sheet supporting means 4a, so that the weight of a sheet sheaf is reduced to ensure the separative conveyance of one sheet in the lowest position, and air flowing between the lowest sheet and the upper side sheet reaches the rear end part, so that the lowest sheet is separated and fed without the generation of double feed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet feeding apparatus for feeding the sheets on the sheet stacking means, which are carried in from the sheet carrying-in means and temporarily stacked, by separating them one by one from the lowermost part. More particularly, the present invention relates to a sheet feeding apparatus used in an image forming apparatus such as a copying machine, a printer, and a facsimile, and particularly suitable for an intermediate tray thereof, and an image forming apparatus using the sheet feeding apparatus.

[0002]

2. Description of the Related Art Conventionally, a sheet feeding device (paper feeding device) provided in an image forming apparatus such as a copying machine, a printer or a facsimile is loaded on a sheet loading tray due to a rotational friction of a paper feeding roller. A method of conveying a sheet is generally used.

In this type of paper feeding device, the surface of the roller is made of an elastic material such as rubber, and the paper feeding performance is largely dependent on the friction coefficient of the surface of the paper feeding roller. Therefore, the feeding performance may not be stable due to changes in the outer shape of the feeding roller due to wear, changes in the material of the feeding roller with time, changes in the friction coefficient of the surface of the feeding roller due to adhesion of paper powder, etc. It had the drawback of not being able to handle sheets in different states.

For these reasons, these days, a sheet feeding apparatus of the type that conveys while separating and adsorbing the sheets stacked on the sheet stacking tray by utilizing the suction of air, the blowing of air, etc. An air feeding device) has been proposed.

The conventional air feeding device sucks the uppermost sheet of the sheet bundle by the suction force of the air and conveys it by the belt, and the nozzle between the uppermost sheet and the sheet below the uppermost sheet is used. There is no one that blows air to separate and can separate and convey the sheet from the bottom of the sheet bundle.

The applicant of the present application has proposed a sheet feeding device for feeding the air feeding device separately from the lowermost sheet of the sheet bundle so that the air feeding device can be used for an intermediate tray, for example ( Unpublished).

The sheet feeding apparatus is shown in FIGS.
As shown in FIG. 3, the sheet is mounted on a duplex unit that carries in an image-formed sheet and then re-feeds it. 19 is a vertical sectional side view of the duplex unit, FIG. 20 is a plan view of the duplex unit,
FIG. 21 shows a front view of the duplex unit, respectively.

The sheet S on which an image is formed is transferred to the carry-in roller 10
The sheet is carried into the sheet tray (intermediate tray) 110 by 8, and hits the paper contact plate 109 arranged on the upstream side thereof, and then falls by its own weight and is stacked on the sheet tray 110. The sheet tray 110 is inclined by 10 ° so that the downstream side in the transport direction is located above, and the sheet S that is carried in and dropped falls on the trailing edge regulating plate 111 and the trailing edge portion is aligned. Reference numeral 119 denotes a side regulation plate that regulates both side portions of the sheet S to be carried in.

In FIG. 19, a sheet conveying section (separating / conveying means) 112 is arranged on the downstream side of the sheet tray 110 on which the sheets S are stacked in the conveying direction.

The sheet conveying section 112 is arranged on the first sheet suction section 113 and on the downstream side of the first sheet suction section 113 in the sheet conveying direction, and the first sheet suction section 113 is provided.
The second sheet suction portion 114 which is inclined downward with respect to the extension line by about 10 ° and a plurality of suction holes 115a.
A conveyor belt (conveying means) 115 hung on each of the sheet suction portions 113 and 114, and the suction hole 115.
a, first sheet suction section 113, second sheet suction section 1
Blower for sucking air through 14 (air sucking means) 1
It is composed of 16.

The conveyor belt 115 includes a plurality of rollers 1.
It is guided by 21, 122, 123, 124, 125. The conveyor belt 115 includes rollers 124, 12
The suction portion 115A of No. 5 abuts on the suction surface of the first sheet suction portion 113, and the suction portion 115B of the rollers 125 and 121 abuts on the suction surface of the second sheet suction portion 114.

Further, as shown in FIGS. 20 and 21, the sheet tray 110 is formed with a cutout portion 110a.
The sheet conveying unit 112 is arranged inside the cutout 110a. The sheet tray 110 includes a base portion 110b and both side portions 110c formed so as to form an angle upward from both ends in the width direction of the base portion 110b.

The base portion 110b of the sheet tray 110
And the first sheet suction portion 113 are substantially parallel to each other, and the conveyor belt 115 is arranged so as to uniformly contact the sheet S. To blow air from above toward the downstream side of the sheet tray 110 in the sheet conveying direction, between the suction surface extension line of the first sheet suction portion 113 and the suction surface of the second sheet suction portion 114. A plurality of blowing nozzles (air blowing means) 117 are provided in the width direction. In the width direction, the spray nozzle 117 is
It is located in the suction area of the conveyor belt 115, and air is blown to the area of the hatched portion 118 in FIG.

Next, the operation of the sheet feeding device (unpublished) proposed by the present applicant will be described.

First, by the suction force of the blower 116, the first
Sheet suction section 113 and second sheet suction section 114
The lowermost sheet S of the sheet bundle stacked on the sheet tray 110 is adsorbed by the transport belt 115 according to the above.

Since the first sheet suction portion 113 and the second sheet suction portion 114 have an angle of about 10 °, only the lowermost first sheet S is separated and the second sheet suction portion 113 is separated. Although it tends to be attracted to the attracting portion 114, a plurality of sheets may tend to be attracted to the second sheet attracting portion 114 due to the entanglement of fibers of the sheets.

Even in such a case, the spray nozzle 11
The air 7 flows into the space between the first and second sheets S, so that the first and second sheets S are separated.

Next, the conveyor belt 115 is driven to convey the sheet S to the downstream side. At this time, the spray nozzle 117
The air flowing out of the sheet flows between the first and second sheets toward the rear end of the sheet and floats the second and subsequent sheets, so that only the lowermost sheet is conveyed to the downstream side. .

[0019]

The above-described sheet feeding apparatus is arranged such that the long sides of the large size sheets such as the third and B4 sheets among the sheets S to be used are perpendicular to the conveying direction. In a device that conveys the sheet, that is, a so-called large-size lateral feed device, the lateral feed of the sheet S can be performed well.

However, in the large-size transverse feed device described above, the increase in the depth of the main body of the device also increases the size of consumable items such as the photosensitive drum and the fixing roller for forming an image on the sheet S. There are problems such as high service costs.

Therefore, in order to avoid these problems, an apparatus for vertically feeding a large size sheet S has been conventionally provided.

However, in the so-called large-size vertical feed apparatus, in which large size sheets such as A3 and B4 are placed so that their long sides are parallel to the transport direction and the sheets are transported, In the case of a large size, the air flow blown from the nozzle 117 toward the tip of S is difficult to reach the rear end. Therefore, at the trailing edge of the sheet S, a gap due to the air flow is not formed between the lowermost sheet and the sheets S and above.

The area of the separation region where the air from the spray nozzle 1117 is introduced and the sheets S are separated from each other is equal to the area of the non-separation region at the rear end of the sheet where the sheets S are in close contact with each other. In comparison, it becomes relatively small. Therefore, when the lowermost sheet S is adsorbed by the conveyor belt 7 and conveyed, the second sheet S is taken out due to the frictional force in the non-separation region at the rear end of the sheet, so-called double feeding occurs. Will be done.

At this time, the blowing nozzle 117 is arranged so that the air flow reaches the rear end of the large size sheet.
It is also conceivable to increase the pressure and flow rate of the air from.

However, in this case, as the flow rate and the pressure of the air flow rise, the blade shape and the rotation speed of the blower for generating the air flow also increase. Therefore, in proportion to this,
This causes a problem that noise from the blower becomes large.

Furthermore, the increase in the flow rate and pressure of the air flow for reaching the rear end of the large size sheet causes the air flow in the small size sheet to become excessive, which disturbs the lamination state. On the contrary, it may lead to a paper feed failure. Also, the sheet tray 11
The number of sheets S stacked on 0 gradually decreases,
When the number of sheets is small, the disorder of the laminated state of the laminated sheets S becomes particularly remarkable. This becomes a more serious problem in thin paper or small size paper having a small basis weight among the sheets S used.

As a measure for avoiding this, it is conceivable to adjust the air flow by a valve provided in the duct according to the size and basis weight of the sheets S or the number of laminated sheets, but in this case, Since the flow rate and pressure are set so that the air flow reaches the rear end of the vertically placed large size sheet, the flow rate and pressure of the air flow increase significantly compared to the above-mentioned sheet feeding device. Becomes

For this reason, even if the valve is used for adjustment, the flow rate and pressure of the air flow can be adjusted delicately so as to cope with even the most problematic case, for example, when a small number of thin small-sized sheets are left. It is impossible to do.

Even if such a delicate adjustment is possible, the structure for achieving it is inevitably complicated, and on the contrary, the reliability of the entire apparatus is lowered. It could be connected.

The present invention reduces the load of the rear end of the sheet due to its own weight, and further allows the air blown to the front end of the sheet to pass through to the rear end of the sheet, thereby making it possible to feed the sheet without causing double feeding. The purpose is to provide a feeding device.

[0031]

The present invention has been made in view of the above circumstances, and is a sheet stacking means (5) capable of stacking a plurality of sheets (S), and the sheet stacking means (5). A sheet carrying-in means (10) for carrying the sheet (S) into
8) and the lowermost sheet (S) stacked on the sheet stacking means (5) are separated by blowing air from the tip side of the sheet (S), and the separated sheet (S) ) Transporting and separating means (112)
And a sheet feeding device for feeding a sheet bundle on the sheet stacking means (5) loaded by the sheet loading means (108) to the separating / transporting means (112) by the air. At the upstream side of the sheet stacking means (5) in the feeding direction, at a predetermined height above the sheet stacking means (5) stacking surface, and at the rear end of the sheet being carried in by the sheet carrying-in means (108). A sheet supporting means (3a, 4a) that can move to an operating position that supports a portion and a retracted position that does not support the rear end portion of the sheet, and the sheet supporting means (3a, 4a), the operating position and the retracted position. The driving means (9) moving to the sheet and the sheet (S) carried into the sheet stacking means (5) by the sheet carrying-in means (108).
Is less than a predetermined amount, the seat supporting means (3a, 4)
a) (14c, 15c) is in the retracted position, and when the predetermined amount is exceeded, the control means (30) for controlling the driving means (9) so that the sheet supporting means (3a, 4a) becomes the operating position. ), And are provided.

Desirably, side regulating means (3, 4) for regulating the side portions of the sheets (S) on the sheet stacking means (5) are provided, and the sheet supporting means (3a, 4).
a) is integrally formed with the side regulating means (3, 4).

[0033]

Based on the above construction, for example, a plurality of large-sized sheets (S) are carried into the sheet stacking means (5) and stacked by the sheet carrying-in means (108) in the longitudinal feed state. When the number of sheets (S) carried into the sheet stacking means (5) by the sheet carrying-in means (108) is less than a predetermined amount, the sheet supporting means (3a, 4a) (14c,
15c) is located at the retracted position, and the entire sheet (S) is stacked on the sheet stacking means (5).

When the number of sheets (S) to be carried in exceeds a predetermined amount, sheet supporting means (3a, 4a) (14c, 15)
c) moves from the retracted position to the operating position. By this movement, the rear end portion of the sheet (S) carried in by the sheet carrying-in means (108) is stacked and supported on the sheet supporting means.

Then, the lowest sheet (S) separated by blowing air to the leading end of the sheet bundle stacked on the sheet stacking means (5) is separated by the separating / conveying means (112). Will be delivered.

At the time of feeding the sheet (S) by the separating / conveying means (112), the rear end portion of a part of the sheet (S) is moved to the sheet supporting means (3a, 4a) (14c, 15).
By being supported by c), the weight of the rear end portion of the sheet bundle is reduced to ensure the separation and conveyance of the lowest one sheet (S), and at the same time, the sheet is blown to the front end portion of the sheet bundle, Lower sheet (S) and upper sheet (S)
The air flowing between and can reliably reach the rear end portion, and the separation and feeding of the lowest sheet (S) can be reliably performed without causing double feeding.

The side portions of the sheets (S) stacked on the sheet stacking means (5) along the sheet conveying direction are restricted by the side restricting means (3, 4) (14, 15). The side regulating means and the sheet supporting means (3a, 4a) (14c, 15c) capable of supporting the rear end portion of the sheet are integrally formed. The integrated sheet supporting means and sheet supporting means are driven by a driving means (9). With this, the side regulating means and the sheet supporting means can be driven by one driving means (9), and the structure of the apparatus can be simplified.

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

[0039]

【Example】

<First Embodiment> FIG. 1 is a vertical sectional front view showing an entire copying machine main body 1 to which a sheet feeding apparatus of the present invention is applied. First, the configuration and operation of a copying machine (image forming apparatus) equipped with a sheet feeding device as a duplex unit will be described.

A document (not shown) is fed by the automatic document feeder 135 to the platen glass 136 provided on the upper part of the copying machine main body 1, and the document is scanned by the optical system 137 to form an image forming unit. A latent image is formed on the photosensitive drum 130. By developing this latent image with a developing device, a toner image is formed on the photosensitive drum 130.

At the time of one-sided copying, the sheets S stored in the cassette 100 which can be pulled out to the front side in the drawing are fed to the sheet feeding unit 1.
The sheet is fed by 32, passes through the transport path 133, and is fed by the sheet feeding unit 13.
Then, the toner image is formed by being transported to 2. Carrier 135
After the toner image is fixed on the sheet S conveyed by the fixing device 101, the plurality of bins 1 are discharged by the discharging roller 102.
It is discharged to the sorter 140 including 41.

During double-sided copying, the operator presses the double-sided copy key on the operation unit (not shown) of the copying machine main body 1 to set the number of double-sided copies. Image formation is performed. After that, the sheet S enters the double-sided reversing path 105 by the flapper 104, the sheet is reversed by the reversing wrapper 106, and the path is changed in the direction of the double-sided unit 2 and conveyed.

Then, the sheet S is carried into the duplex unit 2 by the carry-in roller 108 of the duplex unit.
The sheet contact plate 1 is provided on the upstream side of the duplex unit 2 in the transport direction.
09 is arranged, the discharged sheet hits the sheet contact plate 109, and then the sheet falls due to gravity, and the sheet tray of the double-sided unit 2 (sheet stacking unit).
5 is loaded on top.

The sheet tray 5 has about 1 downstream side in the conveying direction.
It is arranged so as to incline upward by 0 °. The sheet S that is carried in by the carry-in roller (sheet carrying-in means) 108 and falls is abutted against the trailing edge regulating plate 111, and the trailing edge of the sheet S is aligned. The carry-in roller 108 and the rear end regulation plate 111 of the duplex unit 2 are
The small size sheet S is configured to move in the left-right direction in the drawing according to the size of the sheet S.
When the sheet is loaded into the duplex unit 2, the sheet is moved to the downstream side in the transport direction and loaded.

The widthwise regulation of the conveyed sheet S is performed by disposing side regulation plates (side regulation means) 3 and 4 on both outer sides of the maximum size of the sheet S in the widthwise direction. It is prevented from protruding outside the tray 5.

When the stacking of the set number of double-sided sheets is completed in the double-sided unit 2, the stacked sheets S are separated and conveyed by the sheet conveying section 112, and then conveyed to the photosensitive drum 130 via the conveying path 133. Image formation on the second side is performed. After that, it is fixed by the heat and pressure of the fixing device 101, and is ejected outside the copying machine main body 1 by the paper ejection roller 102.

2 to 4 are views showing a double-sided unit 2 equipped with a sheet feeding apparatus according to the first embodiment of the present invention. FIG. 2 is a vertical sectional side view of the double-sided unit 2. 3 and 4 are plan views of the double-sided unit 2, and FIG. 5 is a view on arrow B in FIG.

In FIG. 2, on the downstream side in the conveying direction of the sheet tray 5 on which the sheets S are stacked, a sheet conveying section 112,
And a spray nozzle 117 are arranged respectively,
Since these are configured in the same manner as the sheet conveying unit 112 and the spray nozzle 117 according to <Related Art> described above, description thereof will be omitted.

In FIG. 5, reference numerals 3 and 4 denote side regulation plates (side regulation means) for regulating the width of the sheets stacked on the duplex unit 2, and 5 denotes a sheet tray (sheet stacking means). The regulation plates 3 and 4 are arranged at two positions in the width direction of the sheet tray 5. The sheet tray 5 functions as an intermediate tray that stacks image-formed sheet materials S and re-feeds them.

The side regulating plate 3 is composed of an L-shaped member having a bottom plate portion and a side plate portion, and faces the center of the sheet tray 5 at a position of a predetermined height on the inner surface of the side plate portion. A sheet supporting member 3a is provided.

Further, on the back surface side of the side regulating plate 3, a pair of pins 3b along the stacking direction (conveying direction) of the sheets S are provided.
Is provided. By loosely fitting the pins 3b into the pair of elongated holes 5a (see FIG. 3) formed in the sheet tray 5, the side regulating plate 3 becomes movable along the width direction of the sheet tray 5. There is. In addition, the side regulation plate 3
The sheet supporting member 3a and the pin 3b provided on the sheet are integrally formed by molding.

The other side regulating plate 4 is also constructed in the same manner, and has a sheet supporting member 4a similar to the sheet supporting member 3a and a pair of pins loosely fitted in a pair of elongated holes 5a of the sheet tray 5. 4b and. However, only this side regulation plate 4 has a light shielding portion 4c on the outer surface of the side plate, and this light shielding portion 4c is detected by the side regulation plate sensor 13 when the side regulation plate 4 is located outside. The side regulating plate 4 and the sheet supporting members 4a, pins 4b, light-shielding portions 4c and the like provided on the side regulating plate 4 are integrally formed of a mold, and are movable along the width direction of the sheet tray 5. .

The sheet tray 5 is provided with the carry-in roller 10
8 is a tray for stacking the sheets S carried in by 8 and has an inclination of about 10 ° upward in the sheet stacking direction. As shown in FIG. 3, the sheet tray 5 is formed with a cutout portion 5b. The sheet conveying unit 112 is arranged inside the cutout 5b.

Further, as shown in FIG. 5, the sheet tray 5
A pair of wings 6 that are inclined upward from the vicinity of both sides of the sheet conveying unit 112 are attached to the. The sheet tray 5 and the first sheet suction section 113
2 are substantially parallel to each other as shown in FIG. 2, and the suction portion 115A of the conveyor belt 115 wound around the first sheet suction portion 113 is arranged so as to uniformly contact the sheet S. The wings 6 are arranged at the same position as the sheet conveying section 112 in the sheet stacking direction.

Next, the drive mechanism for the side regulating plates 3 and 4 will be described.

FIG. 6 and FIG. 7 show views as seen from the arrow C in FIG.

In FIG. 6, reference numeral 7 denotes side plates provided on both sides of the double-sided unit 2, and drive stays 8 having front and rear side plates 8a are fixed to the side plates 7 with screws. As shown in FIG. 2, a stepping motor (driving means) 9 is fixed to a central portion of the drive stay 8, and a pinion gear 10 is fixed to an output shaft 9a of the stepping motor 9.

On both sides of the pinion gear 10, as shown in FIG. 6, the rack 1 is provided on the side surface facing the pinion gear 10.
A pair of molded sliders 11 on which 1a is formed are provided. The elongated hole 11b formed in the slider 11 is crimped to the drive stay 8
The slider 11 is configured to be movable in the width direction of the seat by being fitted into the pin 12 at the position.

The pinion gear 10, the slider 11 and the like constitute drive transmission means (interlocking mechanism) for transmitting the drive of the stepping motor 9 to the side regulating plates 3 and 4 and the sheet supporting members 3a and 4a.

FIG. 7 is a diagram after each slider 11 has moved to the inside (the central portion of the drive stay 8). Also,
An urging member 11c integral with the slider 11 is provided on the opposite side of the slider 11 from the rack 11a, and the urging member 11c always contacts the side plate 8a of the drive stay 8 while the slider 11 is moving. As a result, the slider 11 is biased toward the pinion 10 side. As a result, the tooth contact between the rack 11a and the pinion 10 is kept constant.

FIG. 8 is a sectional view taken along the line DD in FIG. 3, and FIG. 9 is a sectional view taken along the line DD in FIG. 4 when the slider 11 moves to the central portion of the drive stay 8.
In FIG. 8, the pin 4b attached to the side regulating plate 4
However, it is fitted in the round hole 11d of the slider 11 of FIG. 6 and is prevented from coming off from the round hole 11d. The side regulating plate 3 on the opposite side has the same configuration. That is, the side regulation plates 3 and 4 move similarly to the sliders 11 to which they are fixed.

Next, the operation until the sheets S are stacked on the duplex unit 2 and separated and conveyed will be described.

(1). Operation unit of the copying machine body 1 (not shown)
In the case where a large-sized multiple-sided copy (for example, the maximum stackable number N) is selected in.

As shown in FIG. 3, the side regulating plates 3, 4
Retreat to both sides of the sheet tray 5,
The sheet support members 3a and 4a of No. 4 are in the retracted position where they do not contact the sheet S carried in by the carry-in roller 108 for the duplex unit.

At this time, the light shielding portion 4c of the side regulating plate 4 is
The side regulating plate sensor 13, which is a photo sensor, is shielded from light, and it is detected that the sheet supporting members 3a and 4a are in the retracted position. In this state, a predetermined number of sheets, for example N /
Two sheets S are stacked on the sheet tray 5.

After the stacking of N / 2 sheets S is completed,
A control device (control means) 30 controls the stepping motor 9 to rotate by a predetermined amount. By the normal rotation of the stepping motor 9 by a predetermined number of rotations, the side regulating plates 3 and 4 move to positions where the spacing is slightly wider than the width of the sheet S, as shown in FIG. Due to the movement of the side regulating plates 3 and 4, these integral sheet supporting members 3a and 4a are located at the operating positions for supporting both side portions of the sheet S, respectively.

Thereafter, the remaining N / 2 sheets S are stacked on the sheets S already stacked on the sheet tray 5 and the sheet supporting members 3a and 4a, as shown in FIG. That is, the remaining succeeding sheets S have their front portions stacked on the conveyor belt 115 and the wings 6, and their rear portions are the sheet supporting members 3 a, 4 of the side regulating plates 3, 4.
It is loaded so as to be supported on a. After the N sheets S have been stacked on the sheet tray 5, the side regulating plates 3 and 4 align the sheets S in the width direction by repeating the forward / reverse rotation of the stepping motor 9.

In this manner, among the sheets S stacked on the sheet tray 5, the lowermost sheet S is sucked by the first belt adsorbing section 113 to the transport belt 115, and the leading end of the sheet S is the second sheet. Due to the suction force of the sheet suction unit 114, the second and subsequent sheets S are sucked by the transport belt 115 and separated, and are transported to the downstream side by the rotation of the transport belt 115.

When the lowest sheet S is separated and conveyed,
The own weight of the sheet S loaded on the rear end portion of the sheet S is N / 2 of the N sheets S stacked on the sheet tray 5.
Since it is a single sheet S, even though the sheet S is a large size sheet, the lowest sheet S can be easily separated and conveyed, and the double feeding of the sheets S can be prevented.

When the lowest sheet S is separated and conveyed,
By blowing air to the lowest sheet S portion by the blowing nozzle 117, air is supplied between the lowest first sheet S and the second sheet S, and the lowest sheet S It is possible to easily separate and convey S.

In this case, the flow of air blown between the first and second sheets S is such that the self-weight of the rear end of the sheet S causes the sheet supporting member 3a, Four
The reduction in the sheet supporting action of a allows the sheet S to easily reach the rear end portion. This allows
The lowermost sheet S is reliably separated and conveyed, and the sheet S
Double feed is prevented.

After the separation and conveyance of the sheet S below the sheet support members 3a and 4a are all completed as described above, the separation and conveyance of the sheet S whose rear end is supported by the sheet support members 3a and 4a. Is performed as shown in FIG. The separation and conveyance of the sheets S are surely performed by the same action as in the case of FIG. 10, and the double feeding of the sheets S is prevented.

When all the sheets on the sheet tray 5 are separated and conveyed as described above, the stepping motor 9
Reverse, the side restriction plates 3 and 4 move to the retracted position,
The light-shielding portion 4c of the side regulating plate 4 has the side regulating plate sensor 13
When is blocked, the stepping motor 9 is stopped T, and the next sheet S is prepared for stacking.

(2). Operation unit of the copying machine body 1 (not shown)
, A small number of large size (for example, M <N /
When double-sided copying in 2) is selected.

When the above selection is made, the M sheets S are stacked with the side regulating plates 3 and 4 and the sheet supporting members 3a and 4a in the retracted position as shown in FIG. When the stacking of the sheets S is completed, the side regulating plates 3 and 4 reciprocate to align the stacked sheets S in the width direction. That is, in this case, the above-mentioned supporting portion 3
The rear end of the sheet is not supported by a and 4a. The separating / conveying operation after stacking the sheets S is performed in the same manner as in (1).

(3). Operation unit of the copying machine body 1 (not shown)
In, when small size double-sided copy is selected.

At the time of stacking the large size sheets, the carry-in roller 108 for the duplex unit and the trailing edge regulating plate 111 at the positions shown in FIG. 2 and FIG.
It is designed to move in the direction of arrow F in FIGS. 12 and 13, and when discharging small size sheets S, they are moved to the downstream side in the transport direction (direction of arrow F) and then discharged. Done. As shown in FIG. 12, when the side regulating plates 3 and 4 are retracted to the retracted position, the sheet S
When the loading is completed and the loading is finished, the side regulation plates 3 and 4
Moves reciprocally with respect to the sheet S to align the sheet in the width direction. Also in this case, the rear end of the sheet is not supported by the supporting members 3a and 4a. The subsequent separation / conveyance operation of the sheet S is performed in the same manner as (1). <Second Embodiment> A second embodiment of the present invention will be described with reference to FIGS.

FIG. 14 is a vertical sectional side view of the duplex unit 16, and FIGS. 15 and 16 are plan views of the duplex unit 16.
7 is a view on arrow G in FIG. 15, and FIG. 18 is a view on G in FIG. In addition, regarding the same parts as the first embodiment,
The same reference numerals are given and the description thereof is omitted.

In FIG. 16, 14 and 15 are side regulating units for regulating the width of the sheets stacked on the double-sided unit 16, which are provided at two positions of the sheet tray 5 in the width direction of the sheets.

The side regulating unit 14 has a base portion fixed to the ring 14a and a side regulating plate 14b fixed to the drive shaft 14a. The side regulating plate 14b is located inside the side regulating plate 14b (on the side of the central portion of the sheet tray 5). ) Is integrally formed with a seat support member 14c that is inclined with respect to the mold. The other side regulation unit 15 is also similar, and is formed by integrally forming a side regulation plate 15b and a sheet support member 15c, the bases of which are fixed to the ring 15a.

The side regulating plate 15b of the drive shaft 15a
A light blocking portion 15d is provided at the free end of the light blocking portion 15d, and when the side regulating plate 15b is located at the side regulating position, the light shielding portion 15d is detected by the side regulating plate sensor 13.

The drive shaft 23 to which the ring 14a is fixed and the drive shaft 17 to which the ring 15a is fixed are
As will be described later, the sheet tray 5 is mounted so as to rotate in conjunction with each other.

Next, the drive means for the side regulating plates 14 and 15 will be described.

17 and 18, reference numeral 18 denotes a stepping motor (driving means) for driving the side regulating units 14 and 15, and the stepping motor 18 is
The drive stays 19 are fixedly arranged at both ends of the sheet tray 5. Stepping motor 18
The drive shaft 17 is the same as the drive shaft of the side regulation unit 15 described above, and therefore the drive of the stepping motor 18 is directly transmitted to the side regulation unit 15.

A timing belt 22 is wound around a timing pulley 21 fixed to the drive shaft 17 and the support shaft 20, respectively, so that the drive shaft 17 is rotationally driven by the support shaft 2.
0, and the support shaft 20 is rotatably mounted on the sheet tray 5 and the drive stay 19. The gears 24 fixed to the support shaft 20 and the drive shaft 23 mesh with each other, and the rotational drive of the support shaft 20 is
The rotation direction is changed and transmitted to the drive shaft 23.

The drive shaft 17, the timing pulley 21,
The timing belt 22, the drive shaft 23, the gear 24, and the like constitute drive transmission means (interlocking mechanism) that transmits the drive of the stepping motor 18 to the side regulating units 14 and 15.

In this way, the stepping motor 18
Is rotated, the side regulating units 14 and 15 are interlocked with each other to rotate, and the stepping motor 18
During normal rotation of the seat, the side regulating plates 14b and 15b are seated on the seat S.
To the side regulation position of the sheet support member 14c, 1
5c moves to an operating position for supporting the sheet S (FIG. 15).
reference). Further, when the stepping motor 18 is rotated in the reverse direction,
The side regulating units 14 and 15 move from the operating position shown in FIG. 15 to the retracted position shown in FIG. 16 and retract.

Next, the operation of the side regulating units 14 and 15 will be described.

First, when a large number of large-sized sheets S are stacked (for example, the maximum stackable number = N), FIG.
4, as shown in FIG. 16, the side regulating units 14, 1
The sheets 5 are retracted to the outside of the sheet tray 5.

In this state, when the N / 2 large size sheets S have been stacked on the sheet tray 5, the control device 30 controls the stepping motor 18 to rotate normally. The normal rotation of the stepping motor 18 causes the side regulating units 14 and 15 to rotate in conjunction with the operating position shown in FIG. When the light blocking portion 15d of the side regulating unit 15 shields the id regulating plate sensor 13, the stepping motor 18 stops.

The side regulating units 14, 1 shown in FIG.
No. 5 is operated so that the side regulating plates 14b and 15b regulate the sheet side at intervals slightly wider than the sheet width, and the sheet supporting members 14c and 15c support N / 2 and subsequent succeeding sheets S. Project into position.

Next, the remaining N / 2 sheets S are stacked on the sheet tray 5 with their rear ends supported on the sheet supporting members 14c and 15c (FIG. 14), and thereafter,
The stepping motor 18 repeats forward / reverse rotation so that the side regulating plates 1 of the side regulating units 14 and 15
4b and 15b align the stacked sheets S in the width direction.

In this way, as shown in FIG. 14, the sheets S stacked on the sheet tray 5 are separated in the same manner as the separating operation described in the first embodiment, and conveyed to the outside of the duplex unit 16. To be done.

When all the sheets S in the double-sided unit 16 have been separated and conveyed, the stepping motor 18 rotates in the reverse direction by a predetermined number of revolutions, and the side regulating units 14 and 15 retract to prepare for the next stacking (see FIG. 16). ).

Large size sheet S to the sheet tray 5
When the number M of sheets to be stacked is M <N / 2 and the small size sheets S are stacked,
The same operation as (2) and (3) of the embodiment
In this case, the rear end of the sheet is not supported by the supporting members 14c and 15c.

In the second embodiment and this embodiment, the number or size of the sheets S to be supported at the trailing edge of the sheet and the number of sheets to be operated by the sheet supporting member are half of the maximum number N of sheets that can be stacked. It goes without saying that the setting can be made not only at the time of reaching (N / 2 sheets), but also appropriately.

Further, the seat supporting member does not necessarily have to be integrally formed with the side regulating plate, but may be separately formed.

Furthermore, the first and second embodiments are notable for their effects in the large size vertical feed device, but they can also be applied to the large size horizontal feed device.

[0099]

As described above, according to the present invention,
It has the following effects.

(1) Since the rear end portion of some of the stacked sheets is located above the sheet stacking means and is supported by the sheet supporting means,
For example, even when feeding large size sheets,
The weight of the rear end portion of the sheet is reduced, and the flow of air blown to the front end portion of the sheet easily reaches the rear end portion of the sheet, ensuring separation of the lowermost sheet and reducing the weight of the sheet. It is possible to prevent the occurrence of sending and non-sending.

(2) Since the weight of the rear end of the sheet can be reduced and the air flow can reach the rear end of the sheet, a large number of sheets can be stacked on the sheet stacking means. For example, when performing double-sided copying and multiplex copying of a large number of sheets, the time required for copying can be shortened, and the productivity of double-sided copying and multiplex copying can be improved.

Further, the sheet supporting means for supporting the rear end portion of some of the sheets stacked on the sheet stacking means and the side regulating plate for regulating the side portions of the stacked sheets are integrally formed. As a result, the following effects are obtained.

(3) Since the driving of the seat supporting means and the side regulating means can be constituted by the same driving means and the same driving transmission means, the driving means and the driving transmission means can be simplified. Further, by simplifying the drive means and the drive transmission means, for example, cost reduction and space saving of the sheet feeding device used as the double-sided unit can be realized.

(5) Since the sheet supporting function at the rear end of the sheet and the aligning function of the sheet can be achieved by the same integrally formed component, the number of components of the sheet stacking means can be reduced, and accordingly, the components can be reduced. It is possible to reduce the manufacturing cost and the assembly cost. (6) The operating position (and the alignment position) of the sheet supporting means (and the side regulating plate) can be set to an arbitrary position, and it is possible to cope with the feeding of sheets of various sizes.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of an image forming apparatus to which a sheet feeding apparatus according to a first exemplary embodiment of the present invention is applied.

FIG. 2 is a vertical sectional side view of the sheet feeding device.

FIG. 3 is a plan view of the sheet feeding device.

FIG. 4 is a functional diagram of the apparatus of FIG.

FIG. 5 is a front view of the sheet feeding device.

FIG. 6 is a plan view of a drive portion of the seat supporting member and the side regulating plate.

FIG. 7 is a plan view of a seat supporting portion and a driving portion of the side regulating plate.

8 is a vertical sectional side view of the side regulating plate and the sheet supporting member portion (sectional view taken along line D-D in FIG. 3).

9 is a vertical sectional side view of the side regulating plate and the sheet supporting member portion (sectional view taken along line D-D in FIG. 4).

FIG. 10 is a vertical cross-sectional side view of the sheet feeding device in which the large size sheets are also stacked.

FIG. 11 is a vertical cross-sectional side view of the sheet feeding device in which the large size sheets are also stacked.

FIG. 12 is a plan view of the sheet feeding device showing the movement state of the trailing edge regulation plate and the carry-in roller when the small size sheets are stacked.

FIG. 13 is a vertical sectional side view of the apparatus shown in FIG.

FIG. 14 is a vertical sectional side view of the sheet feeding device according to the second embodiment of the present invention.

FIG. 15 is a plan view of the sheet feeding device.

FIG. 16 is a plan view of the sheet feeding device.

FIG. 17 is a view taken along the line GG in FIG.

FIG. 18 is a view taken along the line GG in FIG.

FIG. 19 is a vertical sectional side view of a sheet feeding device according to a technique related to the present invention.

FIG. 20 is a plan view of the sheet feeding device.

FIG. 21 is a front view of the sheet feeding device.

[Explanation of symbols]

S sheet 1 copier main body 2 double-sided unit 5 sheet tray (sheet stacking means) 3,4 side regulating plates (side regulating means) 3a, 4a sheet supporting member (sheet supporting means) 9 stepping motor (driving means) 10 pinion gear 11 Sliders 10 and 11 Drive transmission means (interlocking mechanism) 14c and 15c Seat support members (sheet support means) 14b and 15b Side regulating plates (side regulating means) 14,15 Side regulating units 17 Drive shafts 18 Stepping motors (driving means) 21 Timing pulley 22 Timing belt 23 Drive shaft 24 Gears 17, 21, 22, 23, 24 Drive transmission means (interlocking mechanism) 30 Control device (control means) 112 Sheet conveying section 113 First sheet suction section 114 Second sheet suction Part 115 Conveyor belt (conveying means) 1 6 blower (air suction means) 117 blowing nozzle (air blowing means) 130 a photosensitive drum (image forming unit)

Claims (10)

[Claims] 1. A sheet stacking unit capable of stacking a plurality of sheets, a sheet carrying-in unit for carrying a sheet into the sheet stacking unit, and a lowermost sheet stacked in the sheet stacking unit, Separation is performed by blowing air from the leading edge side, and separation / conveyance of the separated sheet is performed.
A sheet feeding unit configured to feed the sheet bundle on the sheet stacking unit loaded by the sheet loading unit one by one from the lowermost portion by the air separating / transporting unit. In the apparatus, a rear end portion of a sheet which is arranged upstream of the sheet stacking means in the sheet feeding direction at a predetermined height from a sheet stacking surface of the sheet stacking means and which is carried in by the sheet carry-in means is supported. And a drive means for moving the seat supporting means to the operating position and the retracted position, and a sheet carrying-in means. When the number of sheets carried into the sheet stacking unit is less than or equal to a predetermined amount, the sheet supporting unit is in the retracted position, and when the amount exceeds the predetermined amount, the sheet supporting unit is in the operating position. A sheet feeding device comprising: control means for controlling the driving means. 2. The sheet feeding device according to claim 1, further comprising side regulating means for regulating side portions of the sheets on the sheet stacking means, wherein the sheet supporting means is integrally formed with the side regulating plate. . 3. A side regulating plate integrally formed with the sheet supporting means is movably supported by the sheet stacking means in a direction orthogonal to the sheet feeding direction, and the driving means is a rotary motor. 3. The sheet feeding device according to claim 2, wherein the output shaft of the rotary motor and the side regulating plate are connected to each other via an interlocking mechanism that converts rotational movement into reciprocating movement. 4. The seat supporting means and the side regulating plate are integrally fixed to a rotary shaft, and the driving means is composed of a rotary motor. The output shaft of the rotary motor and the rotary shaft are connected to the rotary power transmission means. The sheet feeding device according to claim 1, wherein the sheet feeding device is connected via a sheet. 5. The sheet feeding apparatus according to claim 1, wherein the driving unit is a stepping motor. 6. The retreat position, the side regulating plate is in a position apart from a sheet carried in by the carrying-in means, and is carried in in the operating position. The distance is set to be slightly wider than the widthwise dimension of the sheets, and the control means sets the drive means a plurality of times in a state where at least a series of sheets by the carry-in means are stacked on the sheet stacking means. The sheet feeding device according to any one of claims 2 to 5, characterized in that the side regulating plate performs a reverse operation to align the sheet bundle. 7. The first sheet suction section, wherein the separating / conveying section is arranged so as to face a lower surface of the lowermost sheet stacked on the sheet stacking section, and which sucks the sheet by air. On the downstream side of the first sheet suction portion in the sheet feeding direction, the sheet is arranged so as to be inclined with respect to the extension line of the first sheet suction portion so as to become more distant toward the downstream side in the sheet feeding direction. A second sheet adsorbing section for adsorbing air, an air sucking means for sucking air for the first and second sheet adsorbing sections, and a plurality of suction holes, and the first and second sheet adsorbing sections. A conveyor belt that is wound around the sheet stacking unit and conveys the sheet on the sheet stacking unit in the feeding direction while sucking the sheet, and is disposed above the downstream end portion of the second sheet suction unit.
7. An air blowing unit that blows air from a sheet front end direction toward a space between the second sheet suction portion and an extension line of the first sheet suction portion, 7. The sheet feeding device according to the item. 8. A trailing edge regulating plate for aligning trailing edges of sheets stacked on the sheet stacking means is provided, and the trailing edge regulating plate is configured to be movable in the sheet carrying-in direction together with the sheet carrying-in means. In the case where the sheet stacking unit carries in a large size sheet with its long side along the carrying-in direction, the trailing edge regulating plate is located upstream of the sheet supporting unit in the sheet feeding direction, and has a small size. When carrying in the sheet of
8. The sheet feeding device according to claim 1, wherein the trailing edge regulating plate is located downstream of the sheet supporting unit in the feeding direction. 9. A sheet feeding apparatus according to claim 1, and an image forming unit for forming an image on a sheet fed by the sheet feeding apparatus. Image forming apparatus. 10. The sheet stacking means is an intermediate tray, and the sheet on which the image is formed by the image forming section is carried in and stacked on the intermediate tray by the sheet carrying-in means, and then the separating / conveying means is provided. The image forming apparatus according to claim 9, wherein the sheets that are conveyed one by one are image-formed again by the image forming unit.