Sheet discharging apparatus and a sheet discharging method

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a sheet discharging apparatus included in an image forming apparatus or a sheet post-processing apparatus connected with the image forming apparatus.

2. Discussion of the Background

In a background sheet post-processing apparatus, for example, as illustrated in

FIG. 23

, a sheet discharging device is provided at a discharging exit, which includes a sheet discharging roller

200

as a driving roller, and a driven roller

202

which can contact and separate from the sheet discharging roller

200

. The sheet discharging device is configured to discharge a sheet or a set of stapled sheets on a sheet discharging tray

206

with the sheet or the set of stapled sheets sandwiched and conveyed between the sheet discharging roller

200

and the driven roller

202

.

The height of the sheets stacked on the sheet discharging tray

206

is detected by a sheet surface detecting device which includes a sheet surface detecting lever

208

positioned at substantially a center of a sheet discharging tray

206

, and sensors

210

and

212

. When the height of the sheets stacked on the sheet discharging tray

206

reaches a predetermined height, the sheet discharging tray

206

is driven to move down so as to receive additional discharging sheets. If the sheet discharging tray

206

is fixed to the sheet post-processing apparatus, the above-described sheet surface detecting device functions as a full stacked sheets detecting device which detects that the sheets are stacked to the full capacity on the sheet discharging tray

206

.

Referring to

FIG. 23

, a reference numeral

214

designates a guide plate which guides the sheet or the set of stapled sheets to the discharging exit of the sheet post-processing apparatus, a reference numeral

216

designates a discharging sensor, and a reference numeral

218

designates a pullback roller which pulls back the discharged sheet to an end fence (not shown) of the sheet discharging tray

206

so as to align the trailing edge of the discharged sheet.

As illustrated in

FIG. 23

, when the set of stapled sheets

204

is discharged on the sheet discharging tray

206

, the stapled sheets

204

are prone to have so-called back curls, i.e., the tip portion of the stapled sheets

204

is curled downward by gravity depending on thickness, weight, or material of the stapled sheets

204

. The back curl increases an angle (α) formed between the stapled sheets

204

and the surface of the sheet discharging tray

206

at the contact point of the tip portion of the stapled sheets

204

with the surface of the sheet discharging tray

206

.

If the discharging operation of the set of stapled sheets

204

continues in the above back curl condition, the stapled sheets

204

may be stacked on the sheet discharging tray

206

with its tip portion bent inward, i.e., the tip portion of the stapled sheets

204

U-shaped, as illustrated in FIG.

24

. The above-described bend of the stapled sheets

204

may cause inadequate stacking and a detection error of the sheet surface detecting device.

The above-described sheet tip portion bending problem occurs not only in the discharged set of stapled sheets but also in the sheet which is discharged one by one on the sheet discharging tray

206

.

In order to address the above-described sheet tip portion bending problem, as illustrated in

FIG. 25

, a known sheet discharging apparatus includes a protrusive member

220

on the surface of the sheet discharging tray

206

such that a relatively small angle is formed between the tip portion of a sheet or a stapled sheets

204

and the surface of the protrusive member

220

. Thereby, bending of the sheet or the set of stapled sheets

204

is avoided. The protrusive member

220

is made detachable from the sheet discharging tray

206

.

However, in the above-described sheet discharging apparatus with the protrusive member

220

, when a sheet is discharged on the sheet discharging tray

206

one by one (hereinafter called a shift stack mode), the surface of a trailing end part of the stacked sheets is projected due to the protrusive member

220

as illustrated in FIG.

26

. In addition, the trailing edge of some sheets does not reach a position to contact a surface of the pullback roller

218

so as to be pulled down by the pullback roller

218

to be abutted against the end fence. As a result, some of the sheets cannot be pulled back surely to be abutted against the end fence, and thereby inadequate stacking is caused.

Moreover, because the surface of the stacked sheets is projected on the protrusive member

220

, as illustrated in

FIG. 27

, a sheet stacking on the stacked sheets does not slide on the surface of the stacked sheets to the end fence by gravity after the trailing edge of the sheet falls down to the surface of the stacked sheet. As a result, the trailing edge of the sheet does not reach a position to contact a surface of the pullback roller

218

so as to be pulled down by the pullback roller

218

to be abutted against the end fence. Thereby, the sheet is not pulled back to be abutted against the end fence, and the sheet is stacked with its leading edge positioned forward.

Further, in the shift stack mode, when the sheet has so-called face curls at the trailing end portions thereof in the sheet discharging direction (i.e., the trailing end portions of the sheet are curled upward), and when the sheet is discharged on the protrusive member

220

, the trailing edge of the sheet is positioned above the surface of the sheet discharging tray

206

. As a result, the trailing edge of the sheet contacts the sheet discharging roller

200

and is pulled by the sheet discharging roller

200

.

In light of the above-described inadequate sheet stacking, when the sheet is discharged in the shift stack mode or the sheet is prone to have face curls, the protrusive member

220

is detached from the sheet discharging tray

206

in the sheet discharging apparatus.

As stated above, in the background sheet discharging apparatus with the protrusive member

220

, an operator is inconvenienced by having to detach and attach the protrusive member

220

according to the types of sheets and stacking mode. Further, when the protrusive member

220

is detached from the sheet discharging tray

206

, the advantage of preventing the sheet tip portion bending problem may be abandoned.

In Japanese Laid-open Patent Publication No. 6-329320 of 1994, an image recording apparatus is described in which a recording condition of a sheet can be visually confirmed one by one in a sheet facedown discharging method.

As illustrated in

FIG. 28

, the characteristic of the above image recording apparatus is that a hook member

224

including a latch part

224

a

at its tip portion, is swingably provided in the vicinity of a downstream side of the sheet discharging device

222

. The hook member

224

swings upward by being pushed by a recorded sheet P, and the sheet P is directed in the sheet discharging direction with the leading edge of the sheet P caught by the latch part

224

a

of the hook member

224

. As the tip portion of the sheet P is turned up by being caught by the latch part

224

a

toward the front side, the recording condition on the underside of the sheet P can be confirmed visually. As the sheet P advances in the sheet discharging direction, the hook member

224

is pushed to swing upward, and then the leading edge of the sheet P is released from the latch part

224

a

and the sheet P falls down to be stacked.

In the above-described image recording apparatus of JP No. 6-329320, the sheet tip portion bending problem can be avoided because the tip portion of the sheet is turned up. However, when a sheet having a strong tension, such as a thick paper or a set of stapled sheets is discharged, the sheet or the set of stapled sheets configured to stretch between the latch part

224

a

and a discharging exit of the image recording apparatus due to the strong tension and the leading edge of the above sheet or sheets may not be released from the latch part

224

a

in an appropriate manner. As a result, inadequate discharging of the sheet or the sheets may be caused.

In another Japanese Utility Model Publication No. 7-45498, a sheet discharging apparatus is described in which a tip portion of a sheet is pinched by a claw on a chain and the sheet is transferred by driving the chain. The sheet is released from the claw at a predetermined position with a cam mechanism.

In the above-described sheet discharging apparatus of JP No. 7-45498, the sheet is discharged adequately without being bent, because the sheet is released from the claw at a designated position. However, a chain driving mechanism, and the cam mechanism which regulates the sheet release from the claw, increase the cost of the sheet discharging apparatus. In addition, because the sheet is transferred with the leading edge of the sheet pinched by the claw, a pinching mark remains at the leading edge of the sheet.

SUMMARY OF THE INVENTION

Accordingly, an object of this invention is to overcome the above-described and other problems with background sheet discharging apparatuses by providing a novel sheet discharging apparatus and method for discharging a sheet or sheets adequately, in which a sheet tip portion bending problem can be prevented with a simple configuration.

According to a preferred embodiment of the present invention, a sheet discharging apparatus includes a sheet discharging device which discharges a sheet on a sheet discharging tray. A sheet tip portion guide device holds a tip portion of the sheet discharged from the sheet discharging device, guides the sheet in a sheet discharging direction while holding the tip portion of the sheet, and releases the sheet by releasing the tip portion of the sheet held.

According to the present invention, the sheet tip portion guide device may include a holding member which holds the tip portion of the sheet and which moves in the sheet discharging direction with the tip portion of the sheet held by a pushing force of the sheet discharged from the sheet discharging device. Thus, the sheet is guided in the sheet discharging direction.

In addition, the holding member may be configured to swing so as to release the tip portion of the sheet by the pushing force of the sheet discharged from the sheet discharging device. The sheet discharging apparatus includes a swing regulation member so as to regulate swings of the holding member for a predetermined distance after the holding member starts to move by the pushing force of the sheet discharged from the sheet discharging device. The swing regulation member may include a shape curved upward in the sheet discharging direction. The sheet discharging apparatus may further include a catch device which catches the holding member at a position in which the holding member does not interfere with the discharged sheet.

The sheet discharging apparatus may further include a displacing device which displaces the swing regulation member such that the holding member is swung at an arbitrary position in the sheet discharging direction to release the tip portion of the sheet. Further, a plurality of the arbitrary positions may be set.

According to the present invention, the tip portion of the sheet may be released by making a moving speed of the holding member faster than a sheet discharging speed of the sheet discharging device. Further, a plurality of arbitrary positions to make the moving speed of the holding member faster than the sheet discharging speed of the sheet discharging device may be set.

The sheet discharging apparatus may further include a sheet release position switch device to select one of the plurality of the arbitrary sheet release positions.

According to the present invention, the sheet tip portion guide device may be configured so as to move to a position in which the sheet tip portion guide device does not interfere with the discharged sheet. The sheet discharging apparatus may further include a shifting device which shifts the sheet tip portion guide device to the position.

The sheet discharging apparatus may further include a control device which controls the shifting device so as to shift the sheet tip portion guide device selectively between a sheet guide position and the position in which the sheet tip portion guide device does not interfere with the discharged sheet according to a sheet process mode.

According to the present invention, the sheet discharging apparatus may further include a sheet correction member provided in the vicinity of the sheet discharging device to regulate a change of a shape of the sheet at substantially a central part of the sheet in the direction perpendicular to the sheet discharging direction.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete appreciation of the present invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

FIG. 1

is a side view illustrating an overall structure of a finisher including a sheet discharging apparatus of the present invention;

FIG. 2

is an explanatory view of an operation of a sheet surface detecting device of the finisher of

FIG. 1

;

FIG. 3

is a perspective view illustrating a moving up and down mechanism of a sheet discharging tray of the finisher of

FIG. 1

;

FIG. 4

is an explanatory view of an operation of an upper limit switch of the sheet discharging tray of the finisher of

FIG. 1

;

FIG. 5

is a side view illustrating a sheet discharging apparatus according to a first embodiment of the present invention;

FIG. 6

is a schematic plan view of a sheet tip portion guide device according to the first embodiment of the present invention;

FIG. 7

is a block diagram illustrating configurations of control parts of the finisher and a copying machine for the sheet discharging apparatus of the present invention;

FIG. 8

is a side view illustrating a condition of the sheet discharging apparatus of

FIG. 5

when a tip portion of a set of stapled sheets is released;

FIG. 9

is a side view illustrating a sheet discharging apparatus according to a second embodiment of the present invention;

FIG. 10

is a perspective view illustrating a main part of a sheet tip portion guide device of the sheet discharging apparatus of

FIG. 9

;

FIG. 11

is a side view illustrating a sheet discharging apparatus according to a third embodiment of the present invention;

FIG. 12

is a side view illustrating a sheet discharging apparatus according to a fourth embodiment of the present invention;

FIG. 13

is a perspective view illustrating a main part of a sheet tip portion guide device of the sheet discharging apparatus of

FIG. 12

;

FIG. 14

is a perspective view illustrating a sheet discharging apparatus according to a fifth embodiment of the present invention;

FIG. 15

is a perspective view illustrating a modification of the sheet discharging apparatus of

FIG. 14

;

FIG. 16

is a perspective view illustrating a condition of the sheet discharging apparatus of

FIG. 15

, when a holding member is caught at a position in which the holding member does not interfere with a discharged sheet or sheets;

FIG. 17

is a side view illustrating a sheet discharging apparatus according to a sixth embodiment of the present invention;

FIG. 18

is a perspective view illustrating a condition of the sheet discharging apparatus of

FIG. 17

, when a sheet tip portion guide device is positioned at a sheet guide position;

FIG. 19

is a block diagram illustrating configurations of control parts of the finisher and the copying machine for the sheet discharging apparatus of

FIG. 17

;

FIG. 20

is a flowchart illustrating steps of a control operation according to the sixth embodiment of the present invention;

FIG. 21

is a side view illustrating a condition of the sheet discharging apparatus of

FIG. 17

, when the sheet tip portion guide device is positioned at a position in which the sheet tip portion guide device does not interfere with a discharged sheet or sheets;

FIG. 22

is a perspective view illustrating a condition of the sheet discharging apparatus of

FIG. 17

, when the sheet tip portion guide device is positioned at a position in which the sheet tip portion guide device does not interfere with a discharged sheet or sheets;

FIG. 23

is a side view illustrating a condition of a background sheet discharging apparatus, when an angle (α) is formed between a tip portion of a set of stapled sheets and a surface of a sheet discharging tray of the background sheet discharging apparatus;

FIG. 24

is a side view illustrating a condition of a background sheet discharging apparatus, when a tip portion of stapled sheets is bent;

FIG. 25

is a side view illustrating a condition of a background sheet discharging apparatus, when an angle is formed between a tip portion of a set of stapled sheets and a surface of a protrusive member of the background sheet discharging apparatus;

FIG. 26

is an explanatory view of inadequate stacking in a background sheet discharging apparatus including a protrusive member;

FIG. 27

is an explanatory view of another inadequate stacking in a background sheet discharging apparatus including a protrusive member; and

FIG. 28

is an explanatory view of an operation of a background sheet discharging apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and more particularly to

FIG. 1

thereof, there is illustrated an overall structure of a sheet post-processing apparatus (hereinafter called a finisher) including a sheet discharging apparatus of the present invention.

In the embodiments of the present invention, the finisher is connected to a side of a photocopying machine

2

as an image forming apparatus. In the vicinity of a sheet transfer portion J which transfers a sheet from the photocopying machine

2

to the finisher, there arc provided an entrance sensor S

1

and entrance rollers

4

. A sheet transferred into the finisher by the entrance rollers

4

is discharged by one of the following three sheet discharging routes according to the sheet processing modes:

(1) the sheet is conveyed through a sheet discharging route A and is discharged from a discharging exit E

1

to a proof tray

6

which is provided at an upper part of the finisher;

(2) the sheet is conveyed through a non-staple route B and is discharged from a discharging exit E

2

to a sheet discharging tray

8

without a stapling operation; and

(3) the sheet is conveyed through a staple route C and is discharged from the discharging exit E

2

to the sheet discharging tray

8

after a stapling operation.

The sheet conveyed by transfer rollers

12

is directed to the sheet discharging route A leading to the proof tray

6

by a separation guide pick

10

, which is disposed downstream from the entrance rollers

4

. The sheet is conveyed by transfer rollers

12

and

14

in the sheet discharging route A and is then discharged on the proof tray

6

by discharging rollers

16

. The separation guide pick

10

is driven by a solenoid (not shown). For directing the sheet to the sheet discharging route A and the proof tray

6

, the separation guide pick

10

is positioned in a position illustrated by a two-dots-and-dash line in FIG.

1

. The above-described rollers (i.e., the entrance rollers

4

, the transfer rollers

12

and

14

, and the discharging rollers

16

), respectively include a drive and driven roller pair. Other transfer rollers and discharging rollers hereinafter denoted by a single numeral also include a drive and driven roller pair.

A separation guide pick

18

is disposed downstream of the separation guide pick

10

, and directs a sheet, which is directed in the horizontal direction by the separation guide pick

10

that is illustrated by a solid line in

FIG. 1

, selectively to the non-staple route B in which a staple operation is not performed and to the staple route C in which a staple operation is performed. The separation guide pick

18

is also driven by a solenoid (not shown) and switches its position selectively between the position illustrated by a solid line in

FIG. 1

(i.e., the position for forming the non-staple route B), and the position illustrated by a two-dots-and-dash line in

FIG. 1

(i.e., the position for forming the staple route C).

In a non-staple mode (i.e., in a sort/stack mode), a sheet is conveyed in the non-staple route B by transfer rollers

20

, and is then discharged to the sheet discharging tray

8

by a sheet discharging device

70

and a sheet tip portion guide device

72

A (both described later). The sheet discharged on the sheet discharging tray

8

is pulled back to an end fence

50

by a sponge-made pullback roller

48

with the trailing edge of the sheet abutted against the end fence

50

, so that the sheet is stacked on the sheet discharging tray

8

with the trailing edge of the sheet aligned.

In a staple mode, a sheet is conveyed in the staple route C by transfer rollers

24

,

26

, and

28

to a staple unit

30

in which a staple operation is performed. A set of stapled sheets is discharged to the sheet discharging tray

8

by the sheet discharging device

70

and the sheet tip portion guide device

72

A.

A detailed operation of the finisher in the staple mode will now be described. The sheet directed to the staple route C is stacked on a staple tray (not shown) by discharging rollers

32

. On the staple tray, the sheet is aligned in the sheet conveying direction one by one by a striking roller

34

. The sheet is aligned in the sheet width direction (i.e., in the direction perpendicular to the sheet conveying direction) by a jogger fence pair

36

. A stapler

38

is driven based on a staple signal transmitted from a control device (not shown) during an interval between jobs. That is, an interval between a time when a last sheet of a set of sheets is stacked and a time when a first sheet of a subsequent set of sheets is stacked in the staple tray. The set of stapled sheets is pushed up by a release belt

42

including a release pick

40

in the direction indicated by an arrow U in

FIG. 1

, and is then discharged to the sheet discharging tray

8

by the sheet discharging device

70

and the sheet tip portion guide device

72

A. The set of stapled sheets discharged on the sheet discharging tray

8

is pulled back to the end fence

50

by the pullback roller

48

with the trailing edge of the sheets abutted against the end fence

50

, so that the sheets are stacked on the sheet discharging tray

8

with the trailing edge of the sheets aligned.

The striking roller

34

is driven and swung by a solenoid (not shown) around a supporting point

34

a,

and periodically strikes the sheet fed to the staple tray so as to abut the sheet against an end fence

44

. The striking roller

34

rotates in a counterclockwise direction. In

FIG. 1

, a reference numeral

46

indicates a guide plate, and a reference character S

2

indicates a discharging sensor.

A sheet surface detecting device

52

is provided above the sheet discharging device

70

. When the height of the stacked sheets on the sheet discharging tray

8

reaches a predetermined height, the sheet discharging tray

8

is driven to move down so as to receive additional discharged sheets. That is, the finisher according to the embodiments of the present invention adopts a configuration in which a large number of sheets can be discharged on the sheet discharging tray

8

.

The sheet surface detecting device

52

includes a sheet surface detecting lever

54

which is aligned with substantially the widthwise center of the sheet discharging tray

8

. Also included are sensors

56

and

58

provided above the sheet discharging device

70

. The sheet surface detecting operation of the sheet surface detecting device

52

is illustrated in FIG.

2

. The sheet surface detecting lever

54

is supported so as to seesaw. One end of the sheet surface detecting lever

54

is disposed to contact the sheet discharging tray

8

when no sheet is stacked thereon as illustrated by a solid line in FIG.

2

. As sheets are stacked on the sheet discharging tray

8

, the one end of the sheet surface detecting lever

54

contacting the surface of the sheets stacked on the sheet discharging tray

8

is raised as illustrated by a two-dots-and-dash line in FIG.

2

. Another end of the sheet surface detecting lever

54

is disposed so as to be detected by the sensors

56

and

58

. The sensors

56

and

58

detect that the sheet discharging tray

8

is at the home position, the height of the stacked sheets on the discharging tray

8

exceeds a predetermined height, and so on, in cooperation with the sheet surface detecting lever

54

.

As illustrated in

FIG. 3

, the sheet discharging tray

8

is provided with a pair of up-down lift belts

62

which are driven by an up-down motor

60

via gears and a timing belt. The discharging tray

8

moves up and down by forward and reverse rotations of the up-down motor

60

. In the vicinity of a lower part of the up-down lift belts

62

, a lower limit sensor

64

is provided. When an interception board

66

, which is provided at one side of the sheet discharging tray

8

, intercepts the lower limit sensor

64

, the up-down motor

60

stops. Thereby, the sheet discharging tray

8

stops moving down at the position of the lower limit sensor

64

, which is the lowest moving position of the sheet discharging tray

8

.

When the sheet discharging tray

8

is moved up, and the pullback roller

48

is pushed up by the sheet discharging tray

8

, as illustrated by a solid line in

FIG. 4

, one end portion of the pullback roller

48

contacts an upper limit switch

68

. Thereby, the upper limit switch

68

is turned off and the up-down motor

60

stops so that the sheet discharging tray

8

stops moving. Thus, breakage of the sheet discharging tray

8

which may be caused by its overrun is prevented.

Referring back to

FIG. 1

, the sheet discharging device

70

includes a discharge drive roller

74

and a discharge driven roller

76

which contacts and presses the discharge driver roller

74

by its gravity or a bias force of a spring (not shown) or the like. The driven roller

76

is provided so as to contact and separate from the drive roller

74

via a supporting plate

78

such that both a sheet and a set of stapled sheets can be discharged through the drive roller

74

and the driven roller

76

. In the staple mode, the supporting plate

78

shifts upward, as illustrated by a two-dots-and-dash line in

FIG. 1

, so as to adjust a nip part between the discharging roller

74

and the driven roller

76

to the thickness of a set of stapled sheets.

Hereinafter, a sheet discharging apparatus according to a first embodiment of the present invention is described. Referring to

FIG. 5

, the sheet tip portion guide device

72

A includes timing pulleys

80

and

82

which are supported by a bracket (not shown) fixed to the finisher; a timing belt

84

which is spanned around the timing pulleys

80

and

82

; a holding member

86

which is provided to the timing belt

84

to receive and hold a tip portion of a sheet or a set of sheets discharged from the finisher; a home position detecting sensor

87

which detects a standby position (i.e. a home position), of the holding member

86

; and a stepping motor

88

which drives the timing pulley

80

located at the upstream side in the sheet discharging direction.

As illustrated in

FIG. 6

, the sheet tip portion guide device

72

A includes a pair of guide plates and is disposed such that the sheet surface detecting lever

54

is positioned in the middle of the pair of guide plates. The sheet tip portion guide device

72

A is configured so as to hold and guide both ends of a leading edge of a sheet or a set of sheets in the sheet discharging direction. The distance between the pair of guide plates of the sheet tip portion guide device

72

A is set to be shorter than the length of the minimum size sheet in the direction perpendicular to the sheet discharging direction.

Referring to

FIG. 7

, a control device

90

including a microcomputer controls the sheet tip portion guide device

72

A. Information from each of the home position detecting sensor

87

, the discharging sensor S

2

and the stepping motor

88

is input to the control device

90

.

In the first embodiment of the present invention, there are two sheet release operation modes to release a sheet or a set of sheets held by the holding member

86

depending on a position at which the sheet or sheets are released from the holding member

86

. The modes are as follows:

(1) a short distance sheet release mode; and

(2) a long distance sheet release mode.

Specifically, in the short distance sheet release mode, the sheet or sheets are released from the holding member

86

by making the moving speed of the holding member

86

faster than the sheet discharging speed of the sheet discharging device

70

after the holding member

86

holds and guides the sheet or sheets through a short distance in the sheet discharging direction. In the long distance sheet release mode, the sheet or sheets are released after the holding member

86

holds and guides the sheet or sheets through a long distance in the sheet discharging direction. The above-described two sheet release operation modes may be selected by manipulating a sheet release position switch device

92

provided to the finisher. When a certain sheet release position is selected with the sheet release position switch device

92

, the control device

90

controls the sheet tip portion guide device

72

A based on the selected sheet release position. Though it is not shown in figures, the control device

90

is configured to display the selected sheet release operation mode, for example, on an operation panel

94

(illustrated in

FIG. 7

) provided to the photocopying machine

2

.

Referring to

FIG. 7

, the information of sheet size, which is set by the manipulation of the operation panel

94

of the photocopying machine

2

or which is detected by a sheet size detecting sensor

96

of the photocopying machine

2

, is input from a control device

98

of the photocopying machine

2

to the control device

90

of the finisher. The above-described two sheet release operation modes may be selected based on the above-described sheet size information as an alternative to the selection with the sheet release position switch device

92

. Specifically, when a small size sheet is set on the operation panel

94

or is detected by the sheet size detecting sensor

96

, the control device

90

controls the sheet tip portion guide device

72

A to release a sheet or a set of sheets in the short distance sheet release mode, and when a large size sheet is set on the operation panel

94

or is detected by the sheet size detecting sensor

96

, the control device

90

controls the sheet tip portion guide device

72

A in the long distance sheet release mode.

Next, a guide operation of the sheet tip portion guide device

72

A is described. Referring to

FIG. 5

, when the discharging sensor S

2

detects the tip portion of the set of stapled sheets

100

, the control device

90

starts to drive the stepping motor

88

so as to move the holding member

86

in the sheet discharging direction after a predetermined time (i.e., when the tip portion of the set of stapled sheets

100

rides on the holding member

86

and is held thereby). At this time, the holding member

86

is controlled to move in the sheet discharging direction at substantially the same speed as the sheet discharging speed of the sheet discharging device

70

. Therefore, the tip portion of the set of stapled sheets

100

is guided in the sheet discharging direction, while being held by the holding member

86

(i.e., riding on the holding member

86

).

Referring to

FIG. 8

, when the short distance sheet release mode is selected with the sheet release position switch device

92

, the control device

90

controls to change a stepping signal input to the stepping motor

88

such that the moving speed of the holding member

86

becomes higher than the sheet discharging speed of the sheet discharging device

70

, when the holding member

86

reaches a position P

1

. As a result, the holding member

86

releases the tip portion of the set of stapled sheets

100

and thereby the set of stapled sheets

100

is left behind, and the tip portion of the set of stapled sheets

100

falls down to the surface of the sheet discharging tray

8

. Because the tip portion of the set of stapled sheets

100

falls down to the surface of the sheet discharging tray

8

after having been guided through a certain distance, an angle (α) formed between the stapled sheets

100

and the surface of the sheet discharging tray

8

at the contact point of the tip portion of the stapled sheets

100

with the surface of the sheet discharging tray

8

becomes much smaller than the angle (α) which is formed when the set of stapled sheets

100

falls down to the surface of the sheet discharging tray

8

immediately after having been discharged from the sheet discharging device

70

as in the background sheet discharging apparatus. Thereby, the bending of the tip portion of the stapled sheets

100

is avoided. The longer the holding member

86

guides the tip portion of the stapled sheets

100

, the smaller the above-described angle (α) becomes. The control device

90

controls the position P

1

by counting the step number of the stepping motor

88

. After the holding member

86

releases the tip portion of the stapled sheets

100

, the control device

90

reverses the stepping motor

88

, and thereby the holding member

86

returns to the home position to wait for the next set of stapled sheets discharged from the sheet discharging device

70

.

Because the moving speed of the holding member

86

and the sheet discharging speed of the sheet discharging device

70

are substantially the same until the tip portion of the stapled sheets

100

is released from the holding member

86

, the holding member

86

may hold the tip portion of the stapled sheets

100

on the surface of the holding member

86

. Therefore, the holding part of the holding member

86

has an L-shaped form and its flat part is formed in a slightly downward slanting condition looking from the side so that the holding member

86

can smoothly release the tip portion of the stapled sheets

100

.

When the long distance sheet release mode is selected with the sheet release position switch device

92

, the control device

90

controls the stepping motor

88

such that the moving speed of the holding member

86

becomes higher than the sheet discharging speed of the sheet discharging device

70

when the holding member

86

arrives at a position P

2

. Even when a sheet is long and curled downward, bending of the sheet is surely avoided with the above long distance sheet release mode.

If the long and curled sheet is discharged in the short distance sheet release mode, the tip portion of the long sheet is pushed up along the surface of the sheet discharging tray

8

after falling down to the sheet discharging tray

8

until the end portion of the sheet is discharged completely, and the tip portion of the sheet may be bent while being pushed up.

If a sheet is not prone to be curled strongly by the finisher and the sheet is discharged adequately without being bent even when the sheet is long, the short distance sheet release mode may be sufficient in the sheet discharging apparatus. This is because the sheet may be pushed up along the surface of the sheet discharging tray

8

after falling down to the sheet discharging tray

8

until the end portion of the sheet is discharged completely. Therefore, the length of the sheet tip portion guide device

72

A in the sheet discharging direction may be short, and accordingly the sheet tip portion guide device

72

A may be made compact.

When the holding member

86

moves a distance longer than the length of the set of stapled sheets

100

in the sheet discharging direction, the tail end of stapled sheets

100

falls down from the sheet discharging device

70

to the sheet discharging tray

8

after the tail end of the stapled sheets

100

passes through the nip portion of the discharging rollers

74

and

76

. Therefore, the tip portion of stapled sheets

100

is released from the holding member

86

in due course without speeding up the movement of the holding member

86

. However, speeding up the movement of the holding member

86

enables the holding member

86

to return to the home position at a relatively short interval. Accordingly, a sheet discharging interval of the sheet discharging device

70

for the set of stapled sheets

100

can be made shorter.

The above-described configuration of the sheet discharging apparatus according to the first embodiment of the present invention is particularly effective in preventing the sheet tip bending problem when the sheet discharging tray

8

is fixed and does not move up and down and when a distance H between the discharging exit E

2

and the surface of the sheet discharging tray

8

is relatively long. This is because the angle between the stapled sheets

100

discharged from the sheet discharging device

70

and the surface of the sheet discharging tray

8

at the contact point between the tip portion of the stapled sheets

100

and the surface of the sheet discharging tray

8

becomes greater as the distance H becomes longer, and thereby the tip of the stapled sheets

100

is prone to be bent.

Though the stepping motor

88

is used as a separate driving source for the sheet tip portion guide device

72

A in the first embodiment of the present invention, other separate driving sources may be used or a driving source for the finisher may be used via a clutch or the like.

Next, a sheet discharging apparatus according to a second embodiment of the present invention is described referring to

FIGS. 9 and 10

. For the sake of clarity, the members having substantially the same functions as the ones used in the above-described first embodiment will be designated with the same code and their description will be omitted.

A sheet tip portion guide device

72

C of the second embodiment has a different configuration from that of the sheet tip portion guide device

72

A of the first embodiment. The characteristic of the sheet tip portion guide device

72

C is that a driving source is not required to drive the holding member. Rather, the holding member moves by a pushing force of the discharged sheet or sheets.

Referring to

FIG. 9

, the sheet tip portion guide device

72

C includes a rail member

120

which is fixed slantwise to the finisher via brackets (not shown), and a holding member

122

which moves through the rail member

120

.

As illustrated in

FIG. 10

, the holding member

122

includes a rectangular U-shaped slider

124

which slides along the inside of the rail member

120

, and a Z-shaped holding section

126

which is swingably supported by the slider

124

. Provided on both sides of a vertical portion

126

a

of the holding section

126

are convex portions

126

b.

The holding section

126

is supported by the slider

124

by engaging the convex portions

126

b

with holes formed in the slider

124

.

Referring further to

FIG. 10

, the rail member

120

is formed by a pair of channel members. Between upper parts of the pair of channel members, a plate cam

128

is sandwiched and is fixed to the channel members as a swing regulation member to regulate swings of the holding section

126

. Further, as illustrated in

FIG. 9

, a stopper

130

is formed at the upstream end of the rail member

120

in the sheet discharging direction to position the holding member

122

at a home position.

When the holding member

122

is located at the home position as illustrated by a solid line in

FIG. 9

, an upper flat portion

126

c

of the holding section

126

abuts against the plate cam

128

, and thereby the holding section

126

cannot swing. When the set of stapled sheets

100

is discharged from the sheet discharging device

70

and the tip portion of the stapled sheets

100

rides on a lower flat portion

126

d

of the holding section

126

while the holding member

122

is located at the home position, the holding member

122

moves by being pushed by the tip portion of the stapled sheets

100

due to the friction between the tip portion of the stapled sheets

100

and the surface of lower flat portion

126

d

of the holding section

126

. If the frictional force between the lower flat portion

126

d

of the holding section

126

and the tip portion of the stapled sheets

100

is relatively small, the holding member

122

starts to move when the tip portion of the stapled sheets

100

abuts against the vertical portion

126

a

of the holding section

126

.

First, the holding member

122

moves at substantially the same speed as the sheet discharging speed of the set of stapled sheets

100

. When the holding section

126

pushed by the stapled sheets

100

reaches the position in which the plate cam

128

does not regulate the holding section

126

, the holding section

126

swings in the clockwise direction as illustrated by a two-dots-and-dash line in FIG.

9

. Thereby, the tip portion of the set of stapled sheets

100

is released from the holding section

126

, and falls to the surface of the sheet discharging tray

8

. Thus, a relatively small angle is formed between the stapled sheets

100

and the surface of the sheet discharging tray

8

at the contact point between the tip portion of the stapled sheets

100

and the surface of the sheet discharging tray

8

. Thus, the stapled sheets

100

are discharged on the sheet discharging tray

8

without being bent.

The holding section

126

is formed such that the lower flat portion

126

d

side is heavier than the upper flat portion

126

c

side. Therefore, immediately after releasing the tip portion of the set of stapled sheets

100

, the holding section

126

swings back in the counterclockwise direction to the original position due to the weight balance between the lower flat portion

126

d

side and the upper flat portion

126

c

side. At the same time, the holding member

122

returns to the home position by its gravity, moving through the slant rail member

120

.

The above-described sheet release position of the holding member

122

can be changed by changing the length of the plate cam

128

in the sheet discharging direction.

In the second embodiment of the present invention, a driving source for moving the holding member

122

is not required, and therefore a driving control operation is not necessary. Thus, according to the second embodiment of the present invention, a sheet discharging apparatus capable of avoiding a bending of a sheet or sheets can be achieved at a relatively low cost.

Referring to

FIG. 11

, another sheet discharging apparatus according to a third embodiment, which also does not require a driving source for a holding member is described.

A sheet tip portion guide device

72

D according to the third embodiment includes a sector-shaped rail member

132

which is fixed to the finisher to serve as a swing regulation member and a holding member

133

to hold discharged sheets.

The holding member

133

includes an arm

134

whose upper end part is swingably supported by the rail member

132

, and a Z-shaped holding section

136

which is swingably supported by a lower end part of the arm

134

via a shaft

136

b.

On a rail surface

132

a

of the rail member

132

, a stopper

138

is provided to position the holding member

133

at a home position.

When the holding member

133

is located at the home position as illustrated by a solid line in

FIG. 11

, the holding section

136

cannot swing due to the regulation by the rail surface

132

a.

When the set of stapled sheets

100

is discharged from the sheet discharging device

70

and the tip portion of the stapled sheets

100

rides on a lower flat portion

136

d

of the holding section

136

while the holding member

133

is located at the home position, the holding member

133

is pushed by the tip portion of the set of stapled sheets

100

due to the friction between the tip portion of the stapled sheets

100

and the surface of the lower flat portion

136

d.

When the frictional force between the lower flat portion

136

d

and the tip portion of the stapled sheets

100

is relatively small, the holding member

133

starts to move when the tip portion of the stapled sheets

100

abuts against the vertical portion

136

a

of the holding section

136

.

Because the rail member

132

is sector-shaped and the rail surface

132

a

is curved upward in the sheet discharging direction, as the sheet or sheets push the holding section

136

of the holding member

133

, the holding member

133

is displaced upward. Thereby, the holding section

136

changes its posture to a posture in which the tip portion of the sheet or sheets can be easily released from the holding section

136

.

In the sheet discharging apparatus according to the third embodiment of the present invention, the tip portion of the sheet or sheets can be released from the holding section

136

at a shorter distance in the horizontal direction and more easily than the sheet discharging apparatus in the second embodiment

When the holding section

136

reaches a position in which the holding section

136

is not regulated by the rail surface

132

a

as indicated by a two-dots-and-dash line in

FIG. 11

, the holding section

136

starts to rotate. Thereby, the tip portion of the set of stapled sheets

100

is released from the holding section

136

and falls to the surface of the sheet discharging tray

8

forming a relatively small angle between the stapled sheets

100

and the surface of the sheet discharging tray

8

at the contact point between the tip portion of the stapled sheets

100

and the surface of the sheet discharging tray

8

. Thus, the stapled sheets

100

are discharged on the sheet discharging tray

8

without being bent.

Like the second embodiment of the present invention, the holding section

136

is formed such that the lower flat portion

136

d

side is heavier than the upper flat portion

136

c

side. Therefore, immediately after releasing the tip portion of the set of stapled sheets

100

, the holding section

136

swings back in the counterclockwise direction to the original position due to the weight balance between the lower flat portion

136

d

side and the upper flat portion

136

c

side. At the same time, the holding member

133

returns to the home position by its gravity.

A fourth embodiment of the present invention is now described referring to

FIGS. 12 and 13

. For the sake of clarity, the members having substantially the same functions as the ones used in the above-described embodiments will be designated with the same code and their description will be omitted.

The characteristics of a sheet discharging apparatus of the fourth embodiment are that it has no driving source to drive a holding member to hold discharged sheets and that it can set a sheet release position for the holding member at arbitrary positions.

Referring to

FIG. 12

, a sheet tip portion guide device

72

E includes a rail member

140

which is fixed slantwise to the finisher via brackets (not shown), a holding member

142

which moves through the rail member

140

, a bar

146

as a swing regulation member to regulate swings of the holding member

142

, and a solenoid

148

serving as a displacing device for the swing regulation member which enables the holding member

142

to swing at an arbitrary position in the sheet discharging direction.

As illustrated in

FIG. 13

, the holding member

142

includes an L-shaped holding section

150

, a pair of arms

152

which extend upward from both upper ends of the holding section

150

and then curve downward slantwise and face each other, and a cylindrically shaped abutment portion

154

which extends between the tip portions of the pair of arms

152

.

At the curved portions of the pair of arms

152

, a shaft

156

is passed through the pair of arms

152

. The shaft

156

is engaged with a rail groove

140

a

of the rail member

140

, and thereby the holding member

142

is swingably supported by the rail member

140

. Further, a stopper

158

is formed at the upstream end of the rail member

140

in the sheet discharging direction to position the holding member

142

at a home position.

When the holding member

142

is located at the home position as illustrated by a solid line in

FIG. 12

, the solenoid

148

is turned off, and the bar

146

is positioned within the rail member

140

and abuts against the abutment portion

154

of the holding member

142

as illustrated by a solid line in FIG.

12

. Thereby, the holding member

142

cannot swing. When the set of stapled sheets

100

is discharged from the sheet discharging device

70

and the tip portion of the stapled sheets

100

rides on the holding section

150

while the holding member

142

is located at the home position, the holding member

142

is pushed by the stapled sheets

100

due to the friction between the tip portion of the stapled sheets

100

and the surface of the holding section

150

. If the frictional force between the holding section

150

and the tip portion of the stapled sheets

100

is relatively small, the holding member

142

starts to move when the tip portion of the stapled sheets

100

abuts against a vertical portion

150

a

(illustrated in

FIG. 13

) of the holding section

150

.

The holding member

142

first moves at substantially the same speed as the sheet discharging speed of the set of stapled sheets

100

. When the solenoid

148

is turned on and the bar

146

is pulled up from the rail member

140

at a predetermined position, the abutment portion

154

becomes free from the regulation by the bar

146

. Therefore, the holding member

142

swings in the clockwise direction by being pushed by the set of stapled sheets

100

as illustrated by a two-dots-and-dash line in FIG.

12

. Thereby, the tip portion of the set of stapled sheets

100

is released from the holding section

150

and falls down on the surface of the sheet discharging tray

8

forming a relatively small angle between the stapled sheets

100

and the surface of the sheet discharging tray

8

at the contact point between the tip portion of the stapled sheets

100

and the surface of the sheet discharging tray

8

. Thus, the stapled sheets

100

are discharged on the sheet discharging tray

8

without being bent.

The holding member

142

is formed such that the holding section

150

side is heavier than the arms

152

side. Therefore, immediately after releasing the tip portion of the set of stapled sheets

100

, the holding member

142

swings back in the counterclockwise direction to the original position due to the weight balance between the holding section

150

side and the arms

152

side. At the same time, the holding member

142

returns to the home position by its gravity, moving along the slant rail groove

140

a.

In the fourth embodiment of the present invention, a sheet release position can be set at arbitrary positions by controlling a timing to turn on and off the solenoid

148

. Like the first embodiment of the present invention, the sheet discharging apparatus can be configured such that a sheet release position is switched among a plurality of sheet release positions by the sheet release position switch device. Like the other embodiments described above, a bending of a tip portion of a sheet can be prevented in the fourth embodiment.

A sheet discharging apparatus according to a fifth embodiment of the present invention is next described referring to FIG.

14

. For the sake of clarity, the members having substantially the same functions as the ones used in the above-described embodiments will be designated with the same code and their description will be omitted.

The sheet discharging apparatus of the fifth embodiment is modified from the one in the third embodiment of the present invention.

A sheet tip portion guide device

72

F according to the fifth embodiment includes a sector-shaped rail member

160

as a swing regulation member, which is fixed on the finisher, and a holding member

162

to hold discharged sheets.

The holding member

162

includes a pair of arms

166

whose upper end portions are rotatively supported by the rail member

160

via a shaft

164

, and a Z-shaped holding section

136

which is swingably supported by lower end portions of the pair of arms

166

via a shaft

168

. Though a stopper is provided on the rail member

160

, the description and illustration of the stopper are omitted.

At an end portion of a rail surface

160

a

of the rail member

160

, a pair of convex portions

170

is integrally formed with the rail member

160

such that the pair of convex portions

170

protrudes in the direction of the thickness of the rail member

160

. The pair of convex portions

170

serves as a catch device to catch the holding member

162

at the position in which the holding member

162

does not interfere with the discharged sheet.

When a thin sheet having weak tension is discharged, the holding member

162

may not be able to guide the thin sheet due to lack of pushing force of the thin sheet, and thus the holding member

162

may interfere with the discharge of the thin sheet. Therefore, when sheets are thin, in order to avoid the interference of the holding member

162

with the thin sheets, the holding member

162

is moved in advance so as to be caught by the pair of convex portions

170

at the position in which the holding member

162

does not interfere with discharged sheets.

Specifically, when an operator swings the holding member

162

upward, the top ends of the pair of arms

166

abut against the pair of convex portions

170

. When the operator further pulls up the holding member

162

strongly, the pair of arms

166

passes over the pair of convex portions

170

because the arms

166

are made of elastic and flexible materials, and is then held by the convex portions

170

with their lower ends caught by the pair of convex portions

170

as illustrated by a solid line in FIG.

16

. When the operator needs to return the holding member

162

to the original position, the pair of arms

166

can be moved by pulling down strongly enough to pass over the pair of convex portions

170

in the opposite manner.

As illustrated in

FIG. 14

, the sheet tip portion guide device

72

F is provided to guide a sheet or a set of sheets discharged from a discharging exit E

2

with both ends of the leading edge of the sheet or sheets held by the holding member

162

. However, when a set of sheets

100

is stapled a central part of the stapled sheets

100

may bulge upward due to stapling when such stapled sheets

100

are discharged. The bulged central part of the stapled sheets

100

may contact an upper edge of the discharging exit E

2

, and thereby the stapled sheets

100

may be caught due to the friction between the stapled sheets

100

and the upper edge of the discharging exit E

2

. As a result, the set of stapled sheets

100

may not be discharged adequately.

In order to avoid the above-described inadequate discharge of the stapled sheets

100

, as illustrated in

FIG. 15

, a sheet correction member

172

is provided in the vicinity of the sheet discharging device

70

(not shown in

FIG. 15

) so as to regulate the bulge of the sheet or sheets at substantially the central part of the sheet or sheets in the direction perpendicular to the sheet discharging direction.

The shape of the sheet correction member

172

is not limited to the one illustrated in

FIG. 15

, and the sheet correction member

172

may be formed in any shape suitable for suppressing a bulge at a central part of the sheet or sheets in the direction perpendicular to the sheet discharging direction. In this embodiment, the shape of the sheet correction member

172

is made similar to the sector portion of the rail member

160

so as to make the sheet discharging speed at the central part of the sheets the same as those of the pair of rail members

160

and discharge the sheet or sheets smoothly. Alternatively, an additional sheet tip portion guide device

72

F may be provided at the central part of the discharging exit E

2

as the sheet correction member

172

.

The above-described catch device, such as the convex portions

170

, may also be provided to the rail member

132

in

FIG. 11

of the third embodiment of the present invention. Moreover, the above-described sheet correction member

172

may be also applicable to each sheet discharging apparatus according to the first through fourth embodiments of the present invention.

A sixth embodiment of the present invention is described referring to

FIGS. 17 through 22

. A characteristic of the sixth embodiment is that a shift of the holding member

162

between a sheet guide position and a position in which the holding member

162

does not interfere with the discharged sheet is made automatically as an alternative to the manual shift by an operator according to the sheet type, which is described in the fifth embodiment.

For the sake of clarity, the members having substantially the same functions as the ones used in the above-described embodiments will be designated with the same code and their description will be omitted.

As illustrated in

FIG. 17

, a sheet tip portion guide device

72

G includes a sector-shaped rail member

160

′, which does not have the pair of convex portions

170

described in the fifth embodiment, and the holding member

162

which is guided by the rail member

160

′. The sheet tip portion guide device

72

G is configured to be shifted by a shifting device

174

to an arbitrary position in which the sheet tip portion guide device

72

G does not interfere with a sheet or sheets.

The shifting device

174

is provided to the finisher such that the shifting device

174

can slide up and down by a guide member (not shown). The shifting device

174

includes a slide base

176

to which the rail member

160

′ is fixed, a bracket

178

which is fixed to the slide base

176

, an arm

184

which is rotatively supported at a central part thereof as a fulcrum by a bracket

180

, which is fixed to the finisher via a shaft

182

, and a solenoid

186

. One end of the arm

184

is rotatively connected to the bracket

178

, and another end is rotatively connected to a tip portion of a movable rod

186

a

of the solenoid

186

.

FIG. 17

illustrates a condition of the sheet discharging apparatus where the solenoid

186

is turned off and the sheet tip portion guide device

72

G is ready to hold and guide a sheet or sheets discharged from the sheet discharging device

70

, which is also illustrated in FIG.

18

.

As illustrated in

FIG. 19

, the solenoid

186

is configured to be controlled by a control device

188

. On an operation panel

94

of the copying machine, an input device

190

(i.e., a switch) is provided to selectively turn on and off the solenoid

186

. The control device

188

includes a microcomputer including a central processing unit (CPU), a random access memory (RAM), a read-only memory (ROM), and the like.

A control operation of the control device

188

for the sheet tip portion guide device

72

G is described referring to a flowchart illustrated in

FIG. 20

, and referring to

FIGS. 21 and 22

.

Referring to the flowchart in

FIG. 20

, the control device

188

judges if a staple mode is selected based on input information from a control device

98

(illustrated in

FIG. 19

) of the copying machine in step S

1

. If the answer is YES in step S

1

, the control device

188

judges if the number of stapled sheets is X or more in step S

2

. When stapled sheets are thin and the number of stapled sheets is small, the sheet tip portion guide device

72

G may not be pushed by the stapled thin sheets and may interfere with the discharge of the stapled thin sheets. Therefore, the number of stapled sheets is judged relative to X in step S

2

to avoid an inadequate discharge of the stapled thin sheets. If the answer is YES in step S

2

, it may be possible to turn off the solenoid

186

to shift the position of the sheet tip portion guide device

72

G to a sheet guide position. However, in this embodiment, an operator's setting for turning on and off the solenoid

186

with the input device

190

is checked first, and the position of the sheet tip portion guide device

72

G is controlled based on the above-described operator's setting. Therefore, after step S

2

, the control device

188

judges if the solenoid

186

is turned off with the input device

190

in step S

3

. If the answer is YES in step S

3

, the control device

188

turns off the solenoid

186

and positions the sheet tip portion guide device

72

G at a sheet guide position in step S

4

.

If the answer is NO in step S

3

, the control device

188

turns on the solenoid

186

so as to shift the sheet tip portion guide device

72

G in step S

5

. Specifically, when the solenoid

186

is turned on, the sheet tip portion guide device

72

G is shifted upward to a position in which the sheet tip portion guide device

72

G does not interfere with a sheet or sheets discharged from the sheet discharging device

70

as illustrated in

FIGS. 21 and 22

. Thereby, as illustrated in

FIG. 22

, a thin paper P, for example, is discharged without being guided by the sheet tip portion guide device

72

G.

Returning to step S

1

or step S

2

, if the staple mode is not selected in step S

1

or if the number of stapled sheets is not X or more in step S

2

, the control device

188

judges if the solenoid

186

is turned on with the input device

190

in step S

6

. If the answer is YES in step S

6

, the control device

188

turns on the solenoid

186

and shifts the sheet tip portion guide device

72

G upward in step S

7

. If the answer is NO in step S

6

, the control device

188

turns off the solenoid

186

and positions the sheet tip portion guide device

72

G at a sheet guide position in step S

4

.

In the above-described control operation steps of the present embodiment, though the control device

188

judges based on the information of the staple mode selection, a sheet type setting device

192

may be provided on the operation panel

94

as illustrated in

FIG. 19

so as to set a sheet type, for example, a thick sheet and a thin sheet, and the control device

188

may control the operation of the sheet tip guide portion

72

G based on the information of the above-described sheet type.

Further, the above-described configuration of the sheet discharging apparatus according to the sixth embodiment may also be applied to each sheet discharging apparatus according to the first through fourth embodiments other than the fifth embodiment.

Furthermore, as an alternative to automatically shifting the position of the sheet tip portion guide device

72

G, an operator may turn on and off the solenoid

186

with a switch each time the sheet or sheets are discharged, so as to shift the position of the sheet tip portion guide device

72

G.

Obviously, numerous additional modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described herein.

This document is based on Japanese Patent Application No.10-217811 filed in the Japanese Patent Office on Jul. 31, 1998, and on Japanese Patent Application No.11-134253 filed in the Japanese Patent Office on May 14, 1999, the entire contents of which are hereby incorporated by reference.

Number	Date	Country	Kind
10-217811	Jul 1998	JP
11-134253	May 1999	JP

Number	Name	Date
4406449	Buck	Sep 1983
4629174	Wakisaka et al.	Dec 1986
6095518	Allenendinger et al.	Aug 2000

Number	Date	Country
0262644	Dec 1988	DE
0212350	Dec 1984	JP
5-43122	Feb 1993	JP
6-166456	Jun 1994	JP
6-329320	Nov 1994	JP
7-45498	Oct 1995	JP

Sheet discharging apparatus and a sheet discharging method

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

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