GB2248608A - Stapling stacks of sheets - Google Patents

Abstract

Stacks of sheets delivered from a printer or photocopier are stapled at desired positions by a single stapler which is moved from one of the desired positions to another by control means acting in accordance with the selected stapling mode. When each of a plurality of stacks is to be stapled at two positions, the last stapling position for each stack is the first stapling position for the next stack to minimise stapler movement.

Description

FINISHER FOR IMAGE FORMING EQUIPMENT The present invention relates to a

finisher for stapling or otherwise finishing sheets which are sequentially driven out of a copier, printer or similar image forming equipment.

A finisher of the type stacking sheets sequentially discharged from image forming equipment on a tray and binding them at a predetermined position by a stapler is extensively used today. This type of finisher may be constructed to staple a sheet stack only at a predetermined position by a. single stapler which is fixed in place at one corner of the finisher, as disclosed in, for example, Japanese Patent Laid-Open Publication Nos.

82263/1981, 290669/1987, and 101268/1988. While this kind of finisher is inherently simple in construction, it cannot staple a sheet stack at a position other than the predetermined position.

To eliminate this problem, a finisher having two staplers has been proposed, as taught in, for example, Japanese Patent Lid-Open Publication Nos. 13364/1989 and 185774/1988.

Although such a dual stapler type finisher enhances productivity by stapling a sheet stack at two positions at the same time, it is expensive due to the two staplers.

It is an object of the present invention to provide an improved finisher which reduces the production cost.

According to the present invention there is provided a finisher capable of binding a stack of sheets sequentially discharged from image forming equipment at a plurality of desired positions comprising a staple section having a single stapler for binding the stack of sheets at the desired positions, a moving device for moving the staple section via the desired positions, and a control unit for controlling the staple section and moving device such that the stack of sheets is stapled at particular positions selected in natching relation to a designated staple node.

Thus with the present invention the finisher is capable of binding a sheet stack at a plurality of desired positions by a single stapler and it is possible to reduce the stapling time.

The invention will be further described by way of non-limitative example with reference to the accompanying drawings in which:

FIG. I is an elevation of image forming equipment in the form of a copier to which a finisher embodying the present invention is applied; FIG. 2 is a section of the embodiment; FIG. 3 is a section along line III-III of FIG. 2; FIG. 4 is a flowchart demonstrating a specific operation of the embodiment; FIGS. 5 and 6 are views showing an alternative embodiment of the present invention; FIGS. 7A-7D each shows a particular position or positions for stapling a stack of sheets; FIG. 8 shows staple mode keys arranged on the copier; FIG. 9 is a block diagram schematically showing a control system for controlling the movement of a stapler; and FIG. 10 is a timing chart showing the interval between successive jobs particular to each mode.

Referring to FIG. I of the drawings, afinisher embodying the present invention is shown and applied to a copier by way of example. As shown, the copier, generally 10, is made up of a body 12, an automatic document feeder (ADF) 14, a mass sheet feeder 16, and a sheet discharging section 18. A finisher, generally 20, is operatively connected to the dicharging section 18. The ADF 14 automatically feeds a stack of documents one by one from a tray 22 to a predetermined illuminating position while driving them out to a table 26. In a two-sided copy mode, the ADF 14 turns over each document and feeds it again to the illuminating position before driving it out to the table 26. To produce a plurality of copies with each of the documents, the ADF 14 cyclically feed the documents a number of times corresponding to the desired number of copies. The mass sheet feeder 16 stores a great amount of sheets which sheet feeding sections 28 and 30 incorporated in the copier body 12 cannot accommodate. The discharging section 16 has a plurality of trays 32 arranged one above another and distributes sheets, or copies, coming out of the copier body 12 in a particular manner matching a sort mode or a stack mode. The finisher 20 functions when a staple mode is selected for stapling stakcs of sheets one by one. When a staple mode is selected, sheets carrying images thereon are routed through the discharging section 16 to the finisher 20 and not to the tray 32.Each stack of sheets having been bound, i. e., a copy is discharged to a tray 34. The copier body 12 executes a conventional arrangement for illuminating a document 24, developing the resulting latent image representative of the document 24, transferring the developed image to a sheet, and fixing the image on the sheet, although not described specifically herein.

As shown in FIG. 2, the discharging section 18 of the copier 10 has an inlet 38 for receiving a sheet driven out by a discharge roller, not shown, incorporated in the copier body 12.

A transport roller 40 transports the sheet into the discharging section 18. A selector in the form of a pawl 42 steers the sheet from the transport roller 40 toward either one of the tray 32 and finisher 20. A sensor 44 is located at the inlet 38 for sensing the leading and trailing edges of the sheet coming in through the inlet 38. The selector 42 is actuated by a solenoid and a spring, not shown.

As also shown in FIG. 2, the finisher 20 has a downwardly extending transport path 46 for guiding the sheet steered into the finisher 20 downward, and a staple section 48 held in an inclined position for stapling sheets successively guided along the transport path 46. As shown in FIGS. 2 and 3, the staple section 48 has a pair of jogger fences 52a and 52b which are each disposed between opposite side panels 50a and 50b of the stapling section 48 in an inclined position. An endless belt 54 is located between the side panels 50a and50b perpendicularly to the lengthwise direction of the jogger fences 52a and 52b. The jogger fences 52a and 52b are affixed to opposite runs of the belt 54. As the belt 54 is moved by a motor 56, it causes the jogger fences 52a and 52b to move back and forth symmetrically to each other. While moving in such a reciprocating motion, the jogger fences 52a and 52b neatly position the right and left ends of a stack of sheets. In addition, the jogger fences 52a and 52b extend from the neighborhood of a discharge roller 58 located at the end of the downward transport path 46 to the neighborhood of the staple tray 34, serving as a guide member for guiding a stapled stack of sheets or copy to the tray 34. An piece 60 is mounted on the rear and in a lower portion of the jogger fence 52a while a home position sensor 62 is mounted on the body of the finisher 20.

is When the piece 60 acts on the sensing section of the home position sensor 62, the sensor 62 determines that the jogger fences 52a and 52b have reached their home position (HP). The jogger fences 52a and 52b are brought to the home position before they start on a sheet positioning operation.

An endless discharge belt 64 is located at the intermediate between the side panels 50a and 50b, FIG. 3, and contained in the same plane as the jogger fences 52a and 52b.

The belt 64 is passed over an upper or drive pulley 66, an intermediate or idle pulley 68, and a lower or driven pulley 70 and driven by a motor 72, FIG. 2.A pawl 74 protrudes from the surface of the belt 64 to sustain a stack of sheets from below. A home position sensor 76 is responsive to the home position of the pawl 74. Guide plates 76a and 76b are located to guide the belt 64. Binding means in the form of stapler S is affixed to a stapler support 78 which is disposed below the jogger fences 52a and 52b. Although not shown in the figures, the rotation of a motor is transmitted to an eccentric crank via a gear and then transformed to a linear movement by a lever, so that the stapler S drives a staple into sheets. The stapler support 78 has a guide slot 84 in which a guide pin 82 studded on a stapler slider 80 is movably received. The stapler slider 80 is disposed below the stapler support 78. In this configuration, the stapler support 78 is movable in one direction, i. e., toward the jogger fence 52a or 52b.

Specifically, the stapler slider 80 is mounted on a guide rod 86 which is affixed to the side panels 50a and 50b. The stapler slider 80 is slidable along the guide rod 86 in a direction perpendicular to the sheet surface of FIG. 2. A guide roller 88 is mounted on a lower portion of the stapler slider 80 to roll on the surface of a stay 9 0 which is mounted on the finisher body.

A guide roller 94 is rotatably mounted on the stapler slider 80 and rollably contacts the cam surface of guide cam 92. The guide cam 92 is affixed to the stay 90 and has the cam surface at the upper end thereof. As a result, the stapler slider 80 is movable together with the stapler support 78 in a reciprocating motion in a direction indicated by an arrow K in FIG. 3. The intermediate portion of the guide cam 92 is concave downward to cause the stapler slider 80 to assume an upper position at opposite sides or a lower position at an intermediate section. A piece 94 is affixed to the upper end of the stapler slider 80 while a home position sensor 96 is mounted on the finisher body. That the stapler S is in a home position is determined when the piece 94 acts on the sensing portion of the home position sensor 96. A stepping motor 98 is mounted on the side panel 50b to move the stapler S in the right-and-left direction via a belt 100. Specifically, the belt 100 to be driven b-.,, the motor 98 is affixed to the stapler slider 80, so that the stapler slider 80 may move in a. reciprocating motion in the right-and-left direction as viewed in FIG. 3. The stapler slider 15 80, guide roller 88, stay 90, guide cam 92, motor 98 and belt 100 constitute a moving device 102 in combination. Reference fences 104a and 104b are interposed between the stapler S and the jogger fences 52a and 52b in such a manner as to be movable in the right-and- left direction independently of the 20 jogger fences 52a and 52b. The lower end of each reference fence 104a or 104b has a hook-like configuration to form a pair of holding portions 106a or 106b which-hold the trailing end of a sheet stack with respect to the transport direction. The holding portions 106a and the holding portions 106b define therebetween engaging portions 108a and 108b, respectively. The stapler S is -g- selectively engageable with the engaging portions 108a. or 108b. The reference fences 104a and104b are movable in the right-and-left direction by being guided by a guide member, not shown. Springs 110 and 112 constantly bias respectively the reference fences 104a. and 104b toward the intermediate between the side panels 50a and 50b. In the specific condition shown in FIG. 3, the left reference fence 104a is located at a home position thereof by the spring 110 because the stapler S is engaged with the engaging portion 108a of the fence 104a, while the right reference fence 104b is returned away from a home position thereof by the spring 112.

As stated above, the reference fences 104a and 104 for positioning the trailing end of a sheet stack are physically separate from the jogger fences 52a and 52b and a constantly biased by the springs 110 and 112 toward the center. This, coupled with the fact that the -reference fences 104a and 104b are each movable together with the stapler S, allows the stapler S to staple a sheet stack at any desired position. When the reference fences 104a and 104b are intentionally dislocated to, for example, remove a jamming sheet, they will automatically return toward the center due to the springs 110 and 112, insuring the engagement of the stapler S with the reference fence 104a or 104b. When the stapler S moves in the previously mentioned upper position at either side of the finisher, the engaging portion 108a. or 108b of the reference fence 104a or 104b is engaged with the stapler S. On the other hand, when the stapler S moves in the lower position at the center of the finisher, the engaging portions 108a and 108b are released from the stapler S. While the stapler S and reference fence 104a or 104b is connected together by the associated engaging portion 108a or 108b, the movement of the stapler S is transferred to the associated reference fence 104a or 104b, causing the reference fence to move together with the stapler S. A control unit for controlling the stapling position is 10 located in the vicinity of an operation board provided on the copier body 12, FIG. 12. Although not shown, the control unit has a CPU for delivering various control signals on the basis of a predetermined program, an input circuit for transforming the output signals of the sensors 44 and 76, home position sensors 15 and inputs on the operation board of the copier 12 to a format which the CPU can handle, a RAM for storing output data of the CPU, and drivers for driving the motors 56, 72 and 98, solenoids, etc. The CPU drives the solenoids, motors 56, 72 and 98 and so forth via the associated drivers while 20 interchanging signals with the RAM, and operation board, according to a predetermined program.

The operation of the illustrative embodiment will be described. The sheet feed by the ADF 14, the copying procedure by the copier 12 and the operation of the discharging section 18 are conventional and will not be described.

Referring to FIG. 4, how the staple section 48 of the finisher 20 staples a stack of sheets is demonstrated. The rest of the operation of the finisher 20 is also conventional and will not be described. Assume that the copier 10 produce K copies of M documents, and that each ccopy is stapled at two positions A and B, FIG. 3.

In FIG. 4, after M documents 24 have been stacked on the tray 22 of the ADF 14, a staple key provided on the operation board of the copier body 12 is pressed to select a staple mode (step P1). It is determined that a stack of sheets should be stapled at the two positions A and B (P2). -Numeral keys also provided on the operation board are operated to enter a desired number of copies K (P3). Initially, the number of copies produced N is reset to zero (P4). In this condition, a copy start button provided on the operation board is pressed (or not pressed when a copying operation is not to be started) (PS). Then, the control unit drives the motor 98 to thereby move the belt 100 (P6). As a result, the belt 100 moves the stapler S from the home position (RP) to the position A corresponding to the stapling position A shown in FIG. 3.

Subsequently, whether or not one copy of the documents has been completed is determined (P7) and, if the answer is negative, this decision is repeated until the answer changes to positive. On the completion of one copy, the control unit sends a staple signal to the motor associated with the stapler S (PS) with the result that the stapler S staples the copy or sheet stack at the position A. Then, the copy number N is incremented by one (P9) and whether or not the resulting N is odd is determined (P10). Because N is odd at this moment, the control unit causes the motor 98 to move the stapler S from the position A to the other position B (P11) via the belt 100. Thereafter, the control unit drives the motor ass6ciated with the stapler S to cause the stapler S to staple the sheet stack at the position B (P13). As the motor 72 drives the discharge belt 64, the pawl 74 of the belt 64 engages with the stapled sheet stack and moves it upward along the jogger fences 52a and 52b due to the movement of the belt 64 until the sheet stack has been discharged to the staple tray 34 (PM. Whether or not N reached K is determined (P1 5). If N is not K, i. e., if N is 1, the program returns to the step P7.

When the next copy of the documents is completed as determined in the step P7, the control unit again causes the stapler S to staple the second copy at the position B in the previous stated manner (P8). As N is incremented to 2 (P2), whether or not the resulting N is odd is determined (P10).

Because N is even (N = 2) at this moment, the control unit causes the motor 98 to move the stapler S from the position B to the position A (S12). After the stapler S has stapled the second copy at the position A (P13), the stapled copy is driven out to the staple tray 34 (P14). Then, whether or not N is K is determined (P15). The steps P7-P14 are repeated until N reaches K. When N reaches K (N = K) as determined in the step P15, the stapler S returns to the home position (P15) to end the stapling operation.

As stated above, the finisher 20 is capable of stapling a stack of sheets at any desired position by the control unit which freely controls the stapling position of a single stapler S. when it is desired to staple each of K copies at two positions A and B, the control unit causes the stapler S having stapled a copy at the positions A and B in this order to staple the next copy at the position B and then the position A. This saves the time otherwise needed for the stapler S to move after stapling the first copy at the position B and thereby allows the stapler S to staple the second copy rapidly. The finisher 20, therefore, achieves an efficient stapling operation despite a single stapler S. Moreover, the finisher 20 is cost-effective because it is operable efficiently as if it were provided with two staplers.

Referring to FIGS. 5 and 6, an alternative embodiment of the present invention is shown. In the figures, the same or similar components and structural elements are designated by the same reference numerals,and redundant description will be avoided for simplicity. As shown, the finisher, generally 20A, has the staple section 48, reference fences 104a and 104b, and jogger fences 52a and 52b. The staple section 48 includes the stapler S. The jogger fences 52a and 52b are automatically positioned in matching relation to the size of sheets to be used.

Specifically, the jogger fences 52a and 52b are movable toward and away from each other over the same distance as each other as measured from the center line 120, i. e., the reference for sheet transport. The stapler S has a stapler driving portion, not shown, which is movable with the staple section 48 independently of the jogger fences 5& and 52b along a line 122 on which the stapling positions are located. Specifically, the staple section 48 is moved by the staple motor along a. guide rod, not shown, which is parallel to the line 122. Part of the is members supporting the jogger fences 52a and 52b are each configured as a holding portion 124& or 124b which extends across the line 122 for supporting the end of a sheet stack. The staple section 48 is selectively retracted so that the holding portions 124a and 124b may not interfere with the section 48 while the latter is in movement.

The staple section 48 moves to a predetermined stapling position and then actuates the stapler S to bind a stack of sheets.

In FIG. 5, assume that the left-hand side and the right-hand side with respect to the center line 120 are the front and the rear, respectively. Then, when characters are printed out on sheets in the orientation shown in FIG. 7A, a front staple mode is selected for stapling the sheets only at the upper front corner. When characters are arranged on sheets in the orientation shown in FIG. 7B, a both-end mode are selected for stapling the sheets at the upper front and upper rear corners.

Further, when characters are arranaged on sheets in the orientation shown in FIG. 7C, a rear mode is selected for stapling the sheets only at the upper rear corner. At this instant, should the rear mode be selected forsheets oriented as shown in shown in FIG. 7D, the stapling position would be different from the ordinary one and would make the resulting copy awkward to handle.

As shown in FIG. 8, staple mode keys 126 are arranged on the copier 10. Assume that one of the staple mode keys 126 is operated to select a particular staple mode. Then, as shown in FIG. 9, the entered information is transferred to a control unit 128 built in the copier 10 and further to a control unit 128 built in the finisher 20A. As a result, a particular position matching the sheet size is calculated, and a staple motor 130 is driven to move the stapler S to such a position. As soon as a copy having a predetermined number of pages has been completed, the stapler S is driven to bind it.

In this embodiment, the single stapler S staples a copy at one position in the rear mode or at two positions in the both-side mode. In the both-side mode, after the stapler S has stapled a copy at two positions, i. e., ended one job, returns to the home position thereof while the first sheet of the next copy arrives at the staple section 48. Of course, such a movement of the stapler S, to the home position consumes a longer period of time than when the stapler S staples a copy only at one position.

It is, therefore, necessary to switch over the interval or waiting time between successive jobs depending on the number of stapling positions, so that the first sheet of the next copy may not contact the stapler S. To meet this requirement, as shown in FIG. 10, the illustrative embodiment selects an interval T, between successive jobs when the front mode or the rear mode is set up or selects another interval T2 (T) TO when the both-side mode is set up. The switchover between the intervals T, and T2 may be effected by manipulating the timing for the feed of a sheet. Alternatively, an arrangement may be made such that the copier 10 sends a staple mode to the finisher 20A over an optical fiber, and the finisher 20A in turn sends a waiting time between jobs matching the staple mode to the copier 10. Such a procedure is practicable with the system shown in FIG. 9.

After the stapling operation, the discharge belt 64 is driven in a manner shown in FIG. 6 to catch the sheet stack 132 with the pawl 74 thereof. As a result, the copy is driven out to the staple tray 34.

As stated above, the illustrative embodiment is also capable of stapling a stack of sheets at a single position or two positions by the stapler S, as desired. In addition, the embodiment prevents a sheet from entering the staple section 48 while the stapler S is in movement.

Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof.

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Claims (5)

-CLAIMS

1. A finisher capable of binding a stack of sheets sequentially discharged from image forming equipment at a plurality of desired positions, comprising:

stapling means comprising a single stapler for binding said stack of sheets at said desired positions; moving means for moving said stapling means via said desired positions; and control means for controlling said stapling means and said moving means such that said stack of sheets is stapled at particular positions selected in matching relation to a designated staple mode.

2. A finisher as claimed in claim 1, wherein said control means further controls said stapling means and said moving means such that when said stapling means staples said stack of sheet at said plurality of positions, the last stapling position of said stack is the first stapling position of the next stack of sheets.

3. A finisher as claimed in claim 1 or 2, wherein said con-trol means further controls said moving means such that the interval between the end of a stapling operation for stapling a stack of sheets at a plurality of positions and the beginning of a stapling operation for stapling the next stack of sheets is changed on the basis of a staple mode selected.

4. A finisher for binding a stack of sheets and coinstructed and arranged to operate substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

5. image forming equipment including a finisher constructed in accordance with claim 1, 2, 3 or 4.