IMAGE FORMING SYSTEM AND SHEET PROCESSING APPARATUS

An image forming system includes an image forming apparatus and a sheet processing apparatus having a stacking unit, a moving unit, and a thermal compression bonding unit. The stacking unit includes a stack of plural sheet having an adhesive layer for bonding the plural sheets together. The thermal compression bonding unit includes a heating member having a heat generation area. In a case where a length of the adhesive layer regarding a longer-side direction of the heating member is greater than a length of the heat generation area, an entire area of the adhesive layer on the plural sheets is heated and pressed by applying heat and pressure to the adhesive layer more than once while changing, via the moving unit, a relative position of the plural sheets having been conveyed onto the stacking unit and the heat generation area regarding the longer-side direction of the heating member.

BACKGROUND

Field

The present disclosure relates to an image forming system and a sheet processing apparatus configured to bond a plurality of sheets together by applying heat and pressure to a layer of an adhesive formed on a sheet.

Description of the Related Art

Japanese Patent Laid-Open No. 2022-075503 discloses an image forming system that includes an image forming apparatus configured to form an image on a sheet and a sheet processing apparatus configured to bond sheets together to create a booklet by heating and pressing an adhesive-use toner layer formed on a sheet. A heater configured to heat an adhesive-use toner layer is built in the sheet processing apparatus. Besides a toner image for image-forming use, an adhesive-use toner layer for gluing sheets together is formed at an end portion on a sheet by the image forming apparatus. Heat and pressure are applied to the adhesive-use toner layer of a plurality of sheets by a heater of the sheet processing apparatus, thereby gluing the sheets together.

SUMMARY

There is a demand for an image forming system and a sheet processing apparatus capable of creating a sheet stack that is longer than the heat generation area of the heater.

In this case, there is a need to create the sheet stack by properly heating and pressing a layer of an adhesive formed on a sheet. Certain aspect of the present disclosure provide an image forming system and a sheet processing apparatus capable of creating a sheet stack by performing heating and pressing properly while taking the above need into consideration.

According to an aspect of the present disclosure, an image forming system includes an image forming apparatus configured to form an image on a sheet, and a sheet processing apparatus that is configured to create a sheet stack by bonding together a plurality of sheets conveyed from the image forming apparatus and that includes a stacking unit, a moving unit, and a thermal compression bonding unit having a heating member that is elongated and a sheet cradle member that faces the heating member, wherein the stacking unit includes a stacking surface on which plural sheets, having a layer of an adhesive formed on the plural sheets by the image forming apparatus for bonding the plural sheets together, are to be stacked, wherein the moving unit is configured to move either one or both of the plural sheets and the thermal compression bonding unit in a longer-side direction of the elongated heating member, wherein the heating member of the thermal compression bonding unit includes a heat generation area configured to heat the adhesive, wherein the thermal compression bonding unit is configured to sandwich and heat the plural sheets stacked on the stacking unit between the heating member and the sheet cradle member, and to bond the plural sheets together by applying pressure while applying heat to the layer of the adhesive formed on the plural sheets by moving either one or both of the heating member and the sheet cradle member, wherein a position of the layer of the adhesive formed on the plural sheets is selectable in the longer-side direction of the heating member, and wherein, in a case where a length of the layer of the adhesive regarding the longer-side direction of the heating member is greater than a length of the heat generation area, an entire area of the layer of the adhesive on the plural sheets is heated and pressed by applying the heat and the pressure to the layer of the adhesive more than once while changing, via the moving unit, a relative position of the plural sheets having been conveyed onto the stacking unit and the heat generation area regarding the longer-side direction of the heating member.

DESCRIPTION OF THE EMBODIMENTS

With reference to the drawings, some embodiments of the present disclosure will now be described. The term “image forming apparatus” as used herein encompasses a wide variety of apparatus configured to form (record) an image on a recording material (recording medium) such as a single-function printer, a copier, a multi-function printer, a commercial printing machine, and the like. The image forming apparatus may be a system (image forming system) embodied by coupling an image forming apparatus body configured to form an image on a recording material to equipment such as a sheet processing apparatus, a sheet feeding apparatus, or the like.

First Embodiment

With reference toFIGS.1to21, a configuration of an image forming apparatus that includes a sheet processing apparatus according to the present embodiment will now be described. First, an overall configuration of an image forming apparatus according to the present embodiment is described here, which will be followed by a description of a configuration of a sheet processing apparatus according to the present embodiment next.

FIG.1is a schematic view of an image forming apparatus100according to a first embodiment. The image forming apparatus100includes a printer body101as an image forming apparatus body having an image forming function (printing function) and a sheet processing apparatus106having a sheet bonding function. That is, the image forming apparatus100can be defined as an image forming system made up of the printer body101, which functions as an image forming apparatus even when configured alone, and the sheet processing apparatus106.

The image forming apparatus100according to the present embodiment, just with a single-apparatus configuration, is capable of creating a booklet through printing and bookbinding by forming an image on sheets S, one by one, using the printer body101, and then by performing thermal compression bonding of the plurality of sheets S using the sheet processing apparatus106. Various kinds of sheet medium different in size and material can be used as the sheet S, for example, paper such as plain paper or thick paper, a surface-treated sheet medium such as coated paper, a plastic film, a cloth, a special-shaped sheet medium such as an envelope or an index sheet, or the like.

Image Forming Apparatus Body

The printer body101is an electrophotographic apparatus that includes a housing101A and an electrophotographic image forming section101B housed in the housing101A. The image forming section101B includes an intermediate transfer belt108, which is an example of an intermediate transfer member, and a process cartridge195disposed along the intermediate transfer belt108. The image forming section101B is an intermediate-transfer-type electrophotographic unit. The process cartridge195(K) includes a photosensitive drum102, which is an example of an image bearing member, a charging device103, which is an example of a charging component, and a development unit105, which is an example of a developing component. The image forming section101B further includes a scanner unit104, which is an example of an exposing component, and a primary transfer roller107.

The development unit105includes a development roller105a,which is an example of the developing component, and a toner container105b,in which a toner (developer) is contained. The development roller105ais supported rotatably by the toner container105b.The process cartridge195can be detachably attached to the housing101A. A toner cartridge196, which contains a toner to be supplied to the development unit105, is detachably mounted in the printer body101. The “housing101A” of the printer body101means a portion excluding the process cartridge195and the toner cartridge196from the printer body101. The housing101A includes a frame member such as a metal frame constituting the framework of the printer body101, and members fixed to this frame body, and forms a mounting space into which the process cartridge195and the toner cartridge196are mounted.

The process cartridge195forms a toner image for image recording on the sheet S using a toner, and forms an adhesive-use toner image for gluing the sheets S together. The printer body101according to the present embodiment has a configuration of a monochrome printer configured to record a monochrome image. The printer body101uses a black toner not only as a toner for image-recording purpose but also as a toner for adhesive purpose (powdery adhesive). As in first to third embodiments to be described later, the toner for adhesive use may be a toner other than a black toner, or may be a dedicated toner used exclusively for adhesive purpose separately from the toner used for recording an image.

The toner cartridge196and the process cartridge195that are mounted in the housing101A are connected to each other through a toner-conveying pipe197. The toner cartridge196is capable of supplying a toner for replenishment to the development unit105through the toner-conveying pipe197.

The scanner unit104, as an example of the exposing component, is disposed under the process cartridge195inside the housing101A. A cassette113(also called “sheet tray”, “storage container”), which is an example of a sheet storage portion configured to store the sheets S to be used for forming an image, is mounted under the scanner unit104in such a way as to be able to be drawn out of the housing101A. One or more optional sheet feeding apparatuses130including an additional cassette(s)113may be coupled to the lower portion of the housing101A.

The intermediate transfer belt108is a movable (rotatable) endless belt stretched on and around a drive roller109a,a stretching roller109b,and a tension roller110, which are configured to rotate on axial lines parallel to one another. Driven by rotation of the drive roller109a,the intermediate transfer belt108moves (turns, performs conveyor action) counterclockwise in the figure. The primary transfer roller107, which is an example of a primary transfer member, is disposed on the inner-side surface of the intermediate transfer belt108at a position where it faces the photosensitive drum102, with the intermediate transfer belt108interposed therebetween. A secondary transfer roller111, which is an example of a transfer member (secondary transfer member), is disposed on the outer-side surface of the intermediate transfer belt108at a position where it faces the drive roller109a,with the intermediate transfer belt108interposed therebetween. A secondary transfer section as an example of a transfer section is formed as a nip between the intermediate transfer belt108and the secondary transfer roller111. The intermediate transfer belt108, the primary transfer roller107, and the secondary transfer roller111constitute a transfer unit (transferring component) configured to transfer the toner image having been formed on the photosensitive drum102, which is an example of the image bearing member, onto the sheet S.

A belt cleaner112, which is an example of a cleaning component configured to clean the intermediate transfer belt108, is provided at a position where it faces the tension roller110, with the intermediate transfer belt108interposed therebetween. The belt cleaner112includes a cleaning member112asuch as a blade or a brush disposed in contact with the intermediate transfer belt108, and a waste toner container198functioning as a collection container. The belt cleaner112removes dregs such as an un-transferred residual toner from the intermediate transfer belt108by using the cleaning member112a,and collects the removed toner, etc. to the waste toner container198.

A fixing device118, which is an example of a fixing component, is disposed over the secondary transfer section inside the housing101A. The fixing device118has a thermal-fixing configuration of fixing a toner image by applying heat. The fixing device118includes a pair of rotary members (for example, a roller pair made up of a fixing roller and a pressing roller) configured to nip and convey the sheet S, and a heat source (for example, a halogen lamp, an induction heating mechanism) configured to heat a toner image on the sheet S via the fixing roller.

Image Forming Operation

When the printer body101performs image forming operation, the sheet S is fed by a feeding roller114functioning as a pickup feeder either from the cassette113in the lower portion of the housing101A or from the cassette113of the sheet feeding apparatus130. A pair of separation rollers115conveys the fed sheets S one by one while performing multiple-fed sheet separation. The sheet S is conveyed by a pulling roller116toward a pair of registration rollers117. A skew of the sheet S is corrected as a result of collision of the leading edge of the sheet S with a nip of the pair of registration rollers117that is in a stopped state. The pair of registration rollers117sends the sheet S to the secondary transfer section at a timing synchronized with the progress of a process of toner image generation by the image forming section101B.

Meanwhile, at the image forming section101B, the photosensitive drum102and the intermediate transfer belt108rotate. The charging device103charges the surface of the photosensitive drum102uniformly. The scanner unit104writes an electrostatic latent image by irradiating the photosensitive drum102with laser light on the basis of image information that represents an image to be recorded on the sheet S. The development unit105performs development using a black toner, thereby developing (visualizing) this electrostatic latent image as a black toner image.

In a case where thermal compression bonding to be described later is performed by the sheet processing apparatus106, the scanner unit104writes an electrostatic latent image by irradiating the photosensitive drum102with laser light on the basis of information that specifies the position of adhesive bonding of the sheets S. As a result of the development of this electrostatic latent image by using the black toner by the development unit105, an adhesive-use toner image is formed on the photosensitive drum102at an area corresponding to the position of adhesive bonding on the sheet S.

The toner image having been formed on the photosensitive drum102(image bearing member) is transferred (primarily transferred) onto the intermediate transfer belt108by the primary transfer roller107, and is then conveyed toward the secondary transfer section due to the turning of the intermediate transfer belt108. Then, a voltage is applied to the secondary transfer roller111at the secondary transfer section to cause a transfer (secondary transfer) of the toner image onto the sheet S coming from the pair of registration rollers117. The sheet S having passed through the secondary transfer section is sent to the fixing device118. Heat and pressure are applied to the toner image while the sheet S passes through the nip between the fixing roller and the pressing roller, causing the softening of the toner. The toner thereafter solidifies, as a result of which the image becomes fixed on the sheet S.

The conveyance path of the sheet S having passed through the fixing device118is switched by a switcher119. In a case where simplex printing is performed, the sheet S is guided by the switcher119onto an ejection path190, and is ejected out of the housing101A by a pair of ejection rollers191. In the present embodiment, the printer body101is coupled to the sheet processing apparatus106via a relay conveyance unit192. The sheet S having been ejected from the pair of ejection rollers191is handed over to the sheet processing apparatus106via a pair of conveyance rollers193of the relay conveyance unit192and next via a pair of conveyance rollers194thereof. In a case where the relay conveyance unit192and the sheet processing apparatus106are not coupled thereto, the pair of ejection rollers191ejects the sheet S as a print output onto a sheet-stacking tray135provided at the top portion of the housing101A.

In a case where duplex printing is performed, the sheet S on the first surface of which an image has been formed is guided by the switcher119to a pair of reversing rollers206. Then, the sheet S, after reversing conveyance (switchback conveyance) by the pair of reversing rollers206, is conveyed toward the pair of registration rollers117via a duplex conveyance path207. An image is formed on the second surface, which is the opposite of the first surface, of the sheet S by passing through the secondary transfer section and the fixing device118. The sheet S is thereafter ejected out of the housing101A by the pair of ejection rollers191.

FIG.2is a diagram illustrating an example of a toner image formed on the sheet S. On the illustrated sheet S, a recording-use toner image38for recording an image such as a text, a figure, a photograph, and/or the like, and an adhesive-use toner image (a layer of an adhesive)39for gluing sheets together, are formed. The adhesive-use toner image (a layer of an adhesive)39, in the present embodiment, is formed by means of an image-forming-use toner. However, the configuration according to the present embodiment is not limited to a configuration of forming the adhesive-use toner image39by means of the image-forming-use toner. The medium used for adhesive bonding is not limited to a toner. A powdery adhesive exclusive for adhesive purpose may be used for forming the adhesive-use toner image39. The position, shape, area size, and the like of the adhesive-use toner image39can be changed in accordance with the configuration of a thermal compression bonding unit167to be described later. In the present embodiment, it is assumed that a layer of an adhesive is formed at an end portion on the sheet S as viewed in a direction intersecting with the conveyance direction of the sheet S. In a case where the image forming apparatus100creates a simplex-printed booklet, the adhesive-use toner image39is formed on one side only of the sheet S (i.e., on the same surface as the surface on which a recording-use toner image is formed). In a case of duplex-printed booklet, the adhesive-use toner image39may be formed on one side only of the sheet S, or on both sides of the sheet S.

Sheet Processing Apparatus

The sheet processing apparatus106includes a buffer unit120configured to put a plurality of sheets S one on top of another and operating as an example of a buffer, an alignment unit156configured to edge-align the plurality of sheets S and operating as an example of an aligner, and a thermal compression bonding unit167configured to bond the sheets S to one another by means of thermal compression bonding. The thermal compression bonding unit167is an example of a sheet adhesive bonding apparatus (an adhesive bonding unit, an adhesive bonder, a thermal compression bonder, a pasting processor) configured to glue the sheets together.

The sheet processing apparatus106further includes an upper ejection tray125and a lower ejection tray137, each of which is configured to be able to move up and down, as ejection destinations where a print-processed output of the image forming apparatus100can be ejected.

The sheet processing apparatus106receives the plurality of sheets S on which an image has been formed by the printer body101one by one, performs gluing processing (thermal compression bonding), and then ejects the processing result as a stack of sheets (booklet). The buffer unit120, the alignment unit156, and the thermal compression bonding unit167will be described in detail later. The sheet processing apparatus106is not only capable of performing the above sheet processing but also capable of ejecting the sheets S on which an image has been formed by the printer body101to the upper ejection tray125or the lower ejection tray137without performing processing thereon.

Buffer Unit

With reference toFIG.3, the buffer unit120will now be explained.FIG.3is a cross-sectional enlarged view of the buffer unit120. The buffer unit120includes a pair of gateway rollers121, a pair of pre-buffer rollers122, a non-return valve123, a pair of reversing rollers124, and a pair of internal ejection rollers126. The buffer unit120further includes a gateway sensor127configured to perform sheet detection and a separation mechanism including a plunger solenoid145and the like for the purpose of opening and closing the pair of reversing rollers124(bring the rollers into contact with, and away from, each other).

Each of the pair of gateway rollers121, the pair of pre-buffer rollers122, the pair of reversing rollers124, and the pair of internal ejection rollers126is a pair of rollers configured to nip and convey a sheet. The pair of gateway rollers121and the pair of pre-buffer rollers122are disposed on a conveyance path (entrance path) where the sheet processing apparatus106receives the sheet S coming in. The pair of reversing rollers124is disposed on a conveyance path (first ejection path, seeFIG.1) that leads to the upper ejection tray125. The pair of internal ejection rollers126is disposed on a conveyance path (internal ejection path, seeFIG.1) that leads from the pair of reversing rollers124toward the thermal compression bonding unit167. The sheet processing apparatus106includes a conveyance path (second ejection path, seeFIG.1) that leads from the thermal compression bonding unit167toward the lower ejection tray137.

The entrance path is formed of an upper entrance guide140and a lower entrance guide141. The first ejection path is formed of an upper reversing guide142and a lower reversing guide143. The internal ejection path is formed of an upper internal ejection guide146and a lower internal ejection guide147. The gateway sensor127is disposed in such a way as to detect the sheet received by the pair of gateway rollers121. The following reflective-type photo sensor, for example, can be used as the gateway sensor127: a reflective-type photo sensor configured to determine whether the sheet S is present or absent by applying infrared light to the entrance path through an opening provided in the upper entrance guide140and detecting reflected light coming back from the sheet S. A hole having a diameter not less than a spot diameter of the infrared light emitted by the gateway sensor127may be provided in the lower entrance guide141so that no infrared light will be reflected when no sheet is passing along the entrance path.

The non-return valve123is disposed downstream of the pair of pre-buffer rollers122in the sheet conveyance direction at the entrance path. The non-return valve123is disposed in such a way as to be able to rotate freely on its rotation shaft123awith respect to the upper internal ejection guide146. The non-return valve123is capable of moving to a first position and a second position. The first position is a position for preventing sheet movement (returning) from the first ejection path to the entrance path. The second position is a position for tolerating sheet movement from the entrance path to the first ejection path. The non-return valve123is urged by a non-illustrated spring in a C2direction from the second position toward the first position. The non-return valve123is configured to move in a C1direction from the first position toward the second position by being pushed by a sheet and, upon the passing of the sheet, return to the first position.

When viewed in the direction of the rotational axial line of the non-return valve123, the tip portion of the non-return valve123located at the first position overlaps with the upper reversing guide142. The tip portion of the non-return valve123has a comb-teeth shape that enables overlapping with the upper reversing guide142. When viewed in the direction of the rotational axial line of the non-return valve123, a space where a sheet can pass is formed between the non-return valve123located at the second position and the upper reversing guide142.

The pair of reversing rollers124is made up of an upper reversing roller124aand a lower reversing roller124b,to both of which a driving force is supplied. The upper reversing roller124aand the lower reversing roller124bare configured such that their rotations are always in sync. A separating lever144is connected to the upper reversing roller124a.The separating lever144is supported in such a way as to be able to rotate freely on its lever fulcrum shaft144awith respect to the upper reversing guide142. The separating lever144is connected rotatably to the plunger solenoid145at its solenoid connection shaft144b.

When an electric current flows to the plunger solenoid145, a core moves in a D1direction illustrated in this figure and, therefore, the separating lever144turns in an E1direction illustrated in this figure. In this case, the pair of reversing rollers124is in a separated state (a nip-opened state), in which the upper reversing roller124aand the lower reversing roller124bare not in contact with each other. When the electric current flowing to the plunger solenoid145stops, due to an urging force of a pressing spring148, the upper reversing roller124amoves in an E2direction, and the core of the plunger solenoid145moves in a D2direction. In this case, the pair of reversing rollers124is in a contact state (a nip-formed state), in which the upper reversing roller124aand the lower reversing roller124bare in contact with each other.

Buffer Operation

Next, the operation of the buffer unit120will now be explained.FIGS.4A to4Hare diagrams illustrating the operation of the buffer unit120. In the description below, it is assumed that sheets come to the sheet processing apparatus106from the printer body101in the order of a sheet S1, a sheet S2, and a sheet S3. As will be described below, the buffer unit120performs operation of putting a new incoming sheet on top of another sheet (a stack) while moving the sheets (the stack) back and forth between the pair of reversing rollers124and the pair of internal ejection rollers126(this operation will be hereinafter referred to as “buffer operation”). In addition, the sheet processing apparatus106increases the speed of sheet conveyance inside itself. In the description below, the speed of sheet conveyance by the pair of gateway rollers121will be denoted as V1, and the speed of sheet conveyance by the pair of pre-buffer rollers122, the pair of reversing rollers124, and the pair of internal ejection rollers126(the speed of conveyance after the acceleration) will be denoted as V2.

As illustrated inFIG.4A, after the passing of the trailing edge of the sheet S1, which is the preceding one, through the gateway sensor127, the speed of conveyance of the sheet S1by the pair of pre-buffer rollers122and the pair of reversing rollers124is increased from V1to V2. Because of this acceleration, the interval of conveyance between the sheet S1and the sheet S2, which is the succeeding one, widens. This makes it possible for the pair of reversing rollers124to perform a switchback of the sheet S1without a collision of the sheet S2with the sheet S1.

As illustrated inFIG.4B, after the trailing edge of the sheet S1leaves the non-return valve123, the conveyance by the pair of reversing rollers124is temporarily stopped.

As illustrated inFIG.4C, the pair of reversing rollers124changes its direction of rotation and then conveys the sheet S1toward the pair of internal ejection rollers126.

As illustrated inFIG.4D, the conveyance of the sheet S1by the pair of reversing rollers124and the pair of internal ejection rollers126is stopped at a position where the leading edge of the sheet S1is located beyond the pair of internal ejection rollers126by a predetermined amount of conveyance after passing therethrough. In addition, after the sheet S1is nipped by the pair of internal ejection rollers126, the upper reversing roller124amoves in the E1direction. This puts the pair of reversing rollers124into a separated state, in which the sheet S2, the succeeding one, is receivable. After the separating operation of the upper reversing roller124a,the sheet S2, the succeeding one, is conveyed to the pair of reversing rollers124.

As illustrated inFIG.4E, after the passing of the trailing edge of the sheet S2, the succeeding one, through the gateway sensor127, the speed of conveyance of the sheet S2is increased from V1to V2, similarly to the sheet S1. At a timing when the sheet S2arrives at a predetermined target position, the pair of internal ejection rollers126conveys the sheet S1toward the pair of reversing rollers124. At a timing when the speed of conveyance of the sheet S1and the speed of conveyance of the sheet S2become substantially equal to each other (i.e., when a speed difference therebetween becomes substantially zero), the upper reversing roller124amoves in the E2direction to bring the pair of reversing rollers124into a contact state. The pair of reversing rollers124, when brought into a contact state, nips the sheet S1and the sheet S2simultaneously. The pair of reversing rollers124undergoes a speed adjustment in such a way as to achieve equality in the speed of conveyance of the sheet S1, S2no later than switching to a contact state from a separated state.

As illustrated inFIG.4F, after the trailing edge of the sheet S2leaves the non-return valve123, the pair of reversing rollers124is put into a temporarily-stopped state again. The target position mentioned above is set such that, at this time, the sheet S1protrudes by a predetermined amount k with respect to the sheet S2in a direction of conveyance from the pair of internal ejection rollers126toward the alignment unit156. In other words, among the sheets having been put one on top of another at the buffer unit120, the sheet S1, which is to be the lower one in the stack when located at the alignment unit156, protrudes downstream in the direction of conveyance toward the alignment unit156, as compared with the sheet S2, which is to be the upper one in the stack when located at the alignment unit156.

As illustrated inFIG.4G, the pair of reversing rollers124changes its direction of rotation and then conveys the sheet S1and the sheet S2toward the pair of internal ejection rollers126. The sheet S1and the sheet S2are conveyed by the pair of internal ejection rollers126toward the alignment unit156. After the sheet S1and the sheet S2are nipped by the pair of internal ejection rollers126, the upper reversing roller124amoves in the E1direction. This puts the pair of reversing rollers124into a separated state, in which the sheet S3, the succeeding one, is receivable.

As illustrated inFIG.4H, after the trailing edge of the sheet S2leaves the pair of reversing rollers124, the upper reversing roller124amoves in the E2direction. This puts the pair of reversing rollers124into a contact state for nipping and conveying the sheet S3.

By repeating the buffer operation described above, the buffer unit120is capable of sending a predetermined number of sheets each time in a state of being put one on top of another to the alignment unit156. Though two-ply buffer operation of putting one sheet on top of another sheet has been taken as an example above, it is possible to further put the sheet S3on top of the sheets S1and S2by temporarily stopping the conveyance of the sheets S1and S2from the state illustrated inFIG.4Gand conveying them in the reverse direction. That is, by repeating the operation fromFIGS.4D to4G, the buffer unit120is capable of creating a sheet stack made up of three or more sheets (for example, five sheets) put one on top of another.

The target position of putting sheets one on top of another is determined on the basis of the timing of detecting the trailing edge of the sheet by the gateway sensor127. For this reason, even when the length of the sheet in the direction of conveyance changes, the buffer operation according to the present embodiment makes it possible to put the sheets one on top of another in a state of being shifted by a predetermined amount k each. The stack of the sheets having been put one on top of another at the buffer unit120is, as illustrated inFIG.1, conveyed from the pair of internal ejection rollers126along an incoming conveyance path202through a pair of intermediate conveyance rollers128to a conveyance roller129. The conveyance roller129and the alignment unit156are in such a positional relationship that, upon the passing of the trailing edge of a sheet through the conveyance roller129, the sheet is stacked on the alignment unit156. InFIG.1, the conveyance roller129and the alignment unit156are located at mutually-overlapping positions in the conveyance direction of the sheet conveyance path when viewed in the axial direction of the conveyance roller129; however, the conveyance roller129and the alignment unit156may be located at mutually-non-overlapping positions in the conveyance direction of the sheet conveyance path as long as the entrance to the alignment unit156is located adjacent to the conveyance roller129. For the purpose of avoiding interference between the trailing edge of already-stacked sheets on the alignment unit156and the leading edge of a succeeding sheet coming in to the alignment unit156, a stack holder flag150configured to suppress a rise curl at the trailing edge of the already-stacked sheets is disposed downstream of the conveyance roller129.

Configuration of Alignment Unit

Next, with reference toFIGS.5and6, a configuration of the alignment unit156will now be described.FIG.5is a cross-sectional view of the alignment unit156.FIG.6is an exploded view of elements that constitute a moving unit159. In the description below and in each of the drawings, a direction in which a pressing member of the thermal compression bonding unit167moves with respect to a receiving member for the purpose of applying pressure to a stack of sheets will be referred to as “Z direction”. The Z direction is a height direction (thickness direction) of a stack of sheets on the alignment unit156. Directions that are orthogonal to each other in a virtual plane orthogonal to the Z direction are defined as an X direction and a Y direction. Where necessary, directions indicated by arrows X, Y, and Z in each of the drawings will be referred to as “+X side”, “+Y side”, and “+Z side” respectively, and their opposite directions will be referred to as “−X side”, “−Y side”, and “−Z side” respectively.

In the present embodiment, the Y direction is substantially parallel to a conveyance direction in which a sheet is conveyed to the alignment unit156by the conveyance roller129. In the present embodiment, the X direction is a sheet width direction orthogonal to the conveyance direction. In the description below, the Y direction may be referred to as “vertical direction”, and the X direction may be referred to as “width direction” or “horizontal direction”. The alignment unit156includes a lower intermediate guide152functioning as an example of a stacking portion configured to support a stack of sheets, an upper intermediate guide151facing the lower intermediate guide152, and a moving unit159including a vertical alignment reference plate154and a vertical alignment roller153.

As illustrated inFIG.6, the vertical alignment reference plate154includes a plurality of sheet contact portions154a,154b,and154carranged next to each other in the sheet width direction, and functions as an example of a restriction member configured to restrict sheet movement due to contact of the leading edge of a sheet therewith. The sheet contact portions154a,154b,and154cdefine a reference position for sheet alignment in the sheet conveyance direction (Y direction). The vertical alignment roller153is held rotatably by a roller holder160. The roller holder160is pivotable by receiving a driving force of a solenoid163. Due to the pivotal motion of the roller holder160, the vertical alignment roller153is able to move between a position of being in contact with the sheet S on the lower intermediate guide152and thus conveying the sheet S and a position of being retracted up away from the sheet S.

A drive motor161is mounted on the moving unit159. The vertical alignment roller153rotates when a driving force of the drive motor161is transmitted thereto via a gear train162. The moving unit159, as a single integrated unit, is capable of moving in the sheet conveyance direction (Y direction) with respect to the lower intermediate guide152. By this means, it is possible to change the relative position of the sheet S and the thermal compression bonding unit167in the sheet conveyance direction (Y direction).

As illustrated inFIG.5, the alignment unit156includes a width alignment member155, a drive motor158, and width alignment reference plates172aand172b(FIG.7A). By receiving the driving force of the drive motor158, the width alignment member155is movable in the sheet width direction (X direction). The width alignment member155includes a plurality of sheet pushing portions155a,155b,and155carranged next to each other in the sheet conveyance direction. As illustrated inFIG.7A, the width alignment reference plates172aand172bare configured as a plurality of plate-like members (sheet contact portions) arranged next to each other in the sheet conveyance direction. The width alignment reference plates172aand172bdefine a reference position for sheet alignment in the sheet width direction (X direction).

Operation of Alignment Unit

With reference toFIGS.7A to7D, the operation of the alignment unit156will now be described. Taken as an example in the description here is a case where the size of a sheet (for example, A4size or A5size is assumed here, but is not limited thereto) is smaller than the size of a pressing plate (plate member)169to be described later. Each ofFIGS.7A to7Dis a schematic view of the alignment unit156as viewed from above in the Z direction. The illustration of the upper intermediate guide151and driving members/components, etc. of the thermal compression bonding unit167is omitted.

When alignment of a stack of sheets on the alignment unit156is to be performed, the moving unit159is positioned to a predetermined standby position in advance in the sheet conveyance direction (Y direction) in accordance with the sheet size. The standby position is a position where the distance from the nip position of the conveyance roller129to the sheet contact portions154ato154cof the vertical alignment reference plate154in the Y direction is slightly greater than the sheet length.

The operation of the alignment unit156will be described below based on a case where an incoming sheet stack is made up of five sheets S1to S5having been put one on top of another at the buffer unit120. The number of the sheets put one on top of another at the buffer unit120is not limited to five but may be changed to any number.

FIG.7Aillustrates a state in which the sheet S1, which is the first one, and the sheet S2, which is the second one, are being conveyed toward the alignment unit156. The moving unit159(the vertical alignment reference plate154and the vertical alignment roller153) have already moved to the standby position in accordance with the sheet size. The width alignment member155is waiting at a position located slightly outward of and away from a sheet-stack-side-edge position so as not to be obstructive to the conveyance of the sheet stack. When the sheet stack passes through the conveyance roller129, it is preferable if the position of the center of the sheet stack in the X direction lies at substantially a middle position between a heating member171and the width alignment member155in the X direction, but is not limited thereto.

FIG.7Billustrates a state in which the trailing edge of the sheet S1, the first one, has left the nip of the conveyance roller129, and the leading edge of the sheet S1has arrived at the vertical alignment roller153. The vertical alignment roller153has been lowered to a contact position in advance due to electric energization to the solenoid163and is being rotated by the drive motor161. The sheet S1is transported toward the +Y side by the vertical alignment roller153and comes into contact with the vertical alignment reference plate154, thereby being aligned in the sheet conveyance direction. After that, each time the succeeding sheet S2to S5leaves the conveyance roller129, the sheet is transported toward the +Y side by the vertical alignment roller153and is brought into contact with the vertical alignment reference plate154, thereby being aligned in the sheet conveyance direction.

FIG.7Cillustrates a state in which each of the five sheets S1to S5has come into contact with the vertical alignment reference plate154, and the alignment of them in the sheet conveyance direction has completed. In this state, by supplying the driving force of the drive motor158(FIG.5), the width alignment member155is moved in the sheet width direction (+X direction). Sheet pushing portions155a,155b,and155cof the width alignment member155push one side edge of the sheets S1to S5, and, due to this pushing, the sheets S1to S5move toward the width alignment reference plates172aand172b.

FIG.7Dillustrates a state in which the other side edge of each of the sheets S1to S5has come into contact with the width alignment reference plates172aand172b.The sheets S1to S5become aligned in the sheet width direction due to this side-edge contact. After this alignment, thermal compression bonding is performed on the five sheets S1to S5by the heating member171to be described later. In a case where a booklet made up of six or more sheets is to be created, the alignment unit156performs preparation to be ready for accepting the sixth sheet (and subsequent sheets), concurrently with the thermal compression bonding of the sheets S1to S5. Specifically, the width alignment member155moves in the retracting direction (toward the-X side).

Thermal Compression Bonding Portion

With reference toFIG.8, a configuration of the thermal compression bonding unit167according to the present embodiment will now be described.FIG.8is a perspective view of the thermal compression bonding unit167. The thermal compression bonding unit167is an example of a sheet adhesive bonding apparatus (an adhesive bonding unit, an adhesive bonder, a thermal compression bonder, a pasting processor) configured to glue the sheets together. As illustrated inFIG.8, the thermal compression bonding unit167includes the heating member171including the pressing plate169, a cradle plate180(sheet cradle member) facing the pressing plate169, and a drive system including a motor177. The cradle plate180is made of an elastic material (elastomer), for example, a silicone rubber. The cradle plate180is an example of a receiving member configured to receive a pressing force of a pressing member. The cradle plate180has an elongated plate-like shape having a thickness in the Z direction and being long in the Y direction. The cradle plate180has a contact surface180aconfigured to be in contact with the lower surface of a stack of sheets. The contact surface180aaccording to the present embodiment is a planar (flat) surface extending substantially perpendicularly to the Z direction.

The heating member171includes the pressing plate169, a heater168, and a metal stay170. The pressing plate169is an example of a pressing member configured to apply pressure to a stack of sheets that is the target of adhesive bonding. The heater168is an example of a heating component configured to heat the pressing member. The pressing plate169has an elongated plate-like shape having a thickness in the Z direction and being long in the Y direction. The pressing plate169is made of, for example, aluminum. The thermal compression bonding unit167is capable of performing thermal compression bonding of a stack of sheets on the alignment unit156along one side extending in the Y direction by using the pressing plate169extending in the Y direction. The alignment unit156and the thermal compression bonding unit167according to the present embodiment are capable of performing so-called longer-side adhesive bonding, in which sheets having a size of A4 or the like are aligned in an orientation in which their longer side is parallel to the sheet conveyance direction (longer-side-feed orientation) and then are bonded using thermal compression bonding at an adhesive bonding area (FIG.2) that is along the longer side. Adhesive bonding other than the longer-side adhesive bonding may be performed by altering the shape of the pressing plate169and the cradle plate180, the arrangement of the thermal compression bonding unit167, and/or the like. For example, the apparatus may be altered to bond the sheets at a corner.

The pressing plate169has a contact surface169aconfigured to be in contact with the upper surface of a stack of sheets. The contact surface169aaccording to the present embodiment includes a ridge portion (FIG.9A) having a cross-sectional shape of protruding in a pressing direction (toward the −Z side) at its center portion in the X direction and extending in the Y direction. The heater168is a ceramic heater in which a pattern of a heat generation resistor is formed on a substrate made of ceramic. The heater168is disposed in contact with the pressing plate169. The pressing plate169and the heater168are supported by the metal stay170. A lift plate172is fixed to the metal stay170of the heating member171.

The lift plate172moves integrally with the heating member171. In the present embodiment, the width alignment reference plates172aand172bmentioned earlier are formed integrally with the lift plate172by bending a part of a metal member of which the lift plate172is made.

The heating member171includes a temperature detector such as a thermistor configured to detect a temperature of the heater168. A control unit of the sheet processing apparatus106controls a surface temperature of the pressing plate169to a predetermined temperature that is suited for thermal compression bonding by controlling power supply to the heater168in accordance with the detection result of the temperature detector.

The drive system of the thermal compression bonding unit167includes the motor177operating as a drive source, a gear train178, a pinion gear179, and a rack gear175.

The gear train178, the pinion gear179, and the rack gear175operate as an example of a drive transmission mechanism configured to transform the rotation of the motor177into a force in a direction in which the heating member171moves (Z direction) and transmit the force to the heating member171. The pinion gear179is connected indirectly to the motor177, with the gear train178interposed therebetween. The pinion gear179is in mesh with the rack gear175. The gear train178, the pinion gear179, and the rack gear175constitute a speed reduction mechanism for obtaining a pressing force required for thermal compression bonding of a stack of sheets. As the speed reduction mechanism, for example, a worm gear or a planetary gear mechanism may be used. Guided by a guide shaft173having a columnar shape and extending in the Z direction, the rack gear175reciprocates in the Z direction. The guide shaft173is fixed to a frame body of the thermal compression bonding unit167. The movement of the heating member171up and down is driven by the motor177. Since the pinion gear179is in mesh with the rack gear175, the rotation of the motor177is transmitted to the rack gear175via a non-illustrated motor gear and the gear train178.

When the thermal compression bonding unit167performs thermal compression bonding of a stack of sheets, the rack gear175moves in the pressing direction (toward the −Z side) due to the driving force transmitted from the motor177. Accordingly, the lift plate172and the heating member171move in the pressing direction (toward the −Z side), and the pressing plate169comes into contact with the sheet stack. The thermal compression bonding unit167moves away from the sheet stack after applying pressure thereto.

Operation of Thermal Compression Bonding Portion

With reference toFIGS.9A to9F, the thermal compression bonding operation of the thermal compression bonding unit167will now be described. Each ofFIGS.9A to9Fis a view of the thermal compression bonding unit167in the sheet conveyance direction (Y direction).

FIG.9Aillustrates the same state as that ofFIG.7C, that is, a state in which the alignment of the sheets S1to S5in the sheet conveyance direction (Y direction) has completed. In this state, the heating member171is located away from the sheet stack in the Z direction.

FIG.9Billustrates the same state as that ofFIG.7D, that is, a state in which the alignment of the sheets S1to S5in the width direction has completed. By being brought into contact with the width alignment reference plates172aand172b,the sheets S1to S5are aligned in the sheet width direction (X direction).

FIG.9Cillustrates a state in which, due to forward rotation of the motor177, the heating member171has moved in the pressing direction (toward the −Z side) and thus in which the contact surface169aof the pressing plate169has come into contact with the sheet S5, which is the topmost one.

FIG.9Dillustrates a state in which, due to continued driving of the motor177, the sheets S1to S5are sandwiched between the pressing plate169and the cradle plate180and thus in which thermal compression bonding of the sheets S1to S5is being performed now.FIG.9Dfurther illustrates that the next sheets S6to S10have come to the alignment unit156, concurrently with the thermal compression bonding of the sheets S1to S5.

FIG.9Eillustrates a state in which, after the completion of the thermal compression bonding of the sheets S1to S5, due to reverse rotation of the motor177, the heating member171has moved (retracted) toward the opposite side in the pressing direction (toward the +Z side) and thus in which the pressing plate169has become separated away from the sheet S5.FIG.9Efurther illustrates that the alignment of the next sheets S6to S10has been performed and, after the retracting movement of the heating member171, the sheets S6to S10have been brought into contact with the width alignment reference plates172aand172b.

FIG.9Fillustrates a state in which, due to forward rotation of the motor177, the heating member171has moved in the pressing direction (toward the −Z side) again, in which the sheets S1to S10are sandwiched between the pressing plate169and the cradle plate180, and thus in which thermal compression bonding of the sheets S6to S10is being performed now. Since an adhesive-use toner image is formed on the upper surface of the sheet S5and/or the lower surface of the sheet S6, the sheet stack made up of the sheets S1to S5, which have already been bonded together, and the sheets S6to S10are bonded to each other by using thermal compression bonding.

The thermal compression bonding unit167is capable of creating a booklet made up of sheets the number of which is greater than a predetermined number by performing the thermal compression bonding operation once each time a sheet stack made up of the predetermined number of sheets is aligned by the alignment unit156. Though an example of creating a booklet made up of ten sheets, the sheets S1to S10, has been described above, it is possible to create a booklet made up of several tens of sheets or more.

After the completion of the thermal compression bonding of all of the sheets that make up a booklet, the booklet made up of the sheets S1to S10is pushed out by the vertical alignment reference plate154and is conveyed in a direction toward a pair of stack ejection rollers136(FIG.1) regarding the sheet conveyance direction. In other words, the vertical alignment reference plate154is an example of a pushing-out member configured to push the sheet stack out of the alignment unit156and the thermal compression bonding unit167. A pushing-out member configured to push out the sheet stack having been processed may be provided separately from the vertical alignment reference plate154serving as a reference for alignment of the sheet stack.

The pair of stack ejection rollers136is a roller pair whose rollers can be opened and closed (can be brought into contact with and away from each other), and accepts the booklet via an ejection conveyance path203. After the leading edge of the booklet in the direction of pushing out the booklet by the vertical alignment reference plate154goes beyond the position of the pair of stack ejection rollers136, the movement of the vertical alignment reference plate154is stopped, and the pair of stack ejection rollers136switches into a contact state. By this means, the pair of stack ejection rollers136conveys the booklet while nipping it and ejects it to the lower ejection tray137. On the other hand, the vertical alignment reference plate154returns to the standby position again after transferring the booklet to the pair of stack ejection rollers136.

In the present embodiment, a case where the length of a sheet is greater than the length of a heat generation resistor (heat generation area)168aof the heater168to be described later is assumed. With reference toFIGS.10to12, a detailed explanation of a structure will be given below. As illustrated inFIG.10, the heater168and the cradle plate180are disposed outward of, in the width direction, a stacking surface156aof the alignment unit (stacking unit)156on which the sheets S are to be placed and stacked.

A sheet comes in to the alignment unit156through a nip between each of two roller pairs of the conveyance roller129, specifically, each pair made up of a first roller129aand a second roller129b.

A specific example of dimensions of the heating member171is illustrated inFIG.11. The length of the heater168is: L1=376.3 mm. The length of the pressing plate169is: L2=315 mm. The length of the heat generation resistor (heat generation area)168aformed in the heater168configured to give heat to the pressing plate169is: L3=311 mm. The heat generation resistor (heat generation area)168ais located inward of each of the two ends of the pressing plate169by L4=2 mm each. The length of the cradle plate180is: L6=315 mm.

In addition, a reference position C where an incoming sheet enters the alignment unit156beyond the second rollers129bof the conveyance roller129is shifted toward the vertical alignment reference plate154by LC=3.32 mm from the end of the pressing plate169in the longer-side direction of the heater168. The length of a legal-size sheet is 356 mm. The length of an A4-size sheet is 297 mm. Therefore, the length of the heat generation resistor (heat generation area)168aof the heating member171according to the present embodiment is greater than the length of an A4-size sheet but is less than the length of a legal-size sheet. The position where a legal-size sheet having come into the alignment unit156is restricted by the vertical alignment reference plate154is, for example, located slightly downward of one end of the heater168in the direction in which the sheet is conveyed to the alignment unit156.

The structure of the heating member171is not limited to a structure including the pressing plate169. The heating member171may apply heat to sheets by using a heater that includes a heat generation resistor, not via a pressing plate. In this case, the substrate of the heater may be made of ceramic as in the present embodiment or may be made of metal.

With reference toFIG.12, a relationship between the length of the heating member171and the length of a legal-size sheet will now be described. The length of a legal-size sheet is 356 mm and is therefore less than the length of the heater168according to the present embodiment, which is 376.3 mm. The length of a legal-size sheet is greater than the length of the heat generation resistor (heat generation area)168aaccording to the present embodiment, which is 311 mm, and the length of the pressing plate169according to the present embodiment, which is 315 mm.

In the present embodiment, as illustrated inFIG.12, the length L2of the heater portion is less than the maximum sheet length Ls supported by the sheet processing apparatus. In addition, the adhesive-use toner image39is arbitrarily selectable within a range Lt that is greater in length than the length L2of the heater portion. The description of the operation of the alignment unit that has been given so far is based on a case where the sheet length Ls is less than the length L2of the heater portion and where the adhesive-use toner image39on the sheet at the point in time of having come onto the lower intermediate guide152overlaps with the heater portion in the Y direction.

Described next below is a case where, as illustrated inFIG.13, the length of a sheet (for example, a legal-size sheet) is greater than the length L2of the heater portion and where the adhesive-use toner image39on the sheet at the point in time of having come onto the lower intermediate guide152does not overlap with the heating member171in the Y direction.

With reference to a block diagram ofFIG.14, control operation of communicating an area where the adhesive-use toner image39is formed to the control unit of the sheet processing apparatus106will now be described. First, when information about a sheet size, an adhesive bonding area pattern, the number of sheets of a booklet, and the like is inputted to an input unit1001, the information about them is conveyed to an image processing control unit1002. With regard to the adhesive bonding area pattern, in the present embodiment, it is assumed that a preset pattern corresponding to the sheet size and corresponding to an adhesive bonding pattern selected by the user has been set in advance. In the present embodiment, a case where the user selects a corner bonding of legal-size sheets is taken as an example. The scope of the present embodiment is not limited to this example. The apparatus may be configured such that the user can set the adhesive bonding area at any position on the sheet. The information about them is further conveyed to a printer body control unit1003. At the printer body101, a layer of an adhesive is formed at, on the sheet, a predetermined position corresponding to the sheet size and corresponding to the adhesive bonding area pattern. The sheet size is detected at the printer body control unit1003, and the detected sheet size is communicated to the image processing control unit1002where it is confirmed that the detected sheet size is the same as the sheet size inputted to the input unit1001. After that, the information about the sheet size and the adhesive bonding area pattern is conveyed to a sheet processing apparatus control unit1004, and heat and pressure are applied to the layer of the adhesive formed at the predetermined position on the sheet. Though the information about the sheet size and the adhesive bonding area pattern is conveyed to the sheet processing apparatus control unit1004from the image processing control unit1002in the above configuration, this does not imply any limitation. For example, as a configuration in which the image processing control unit1002, the printer body control unit1003, and the sheet processing apparatus control unit1004are configured as a single integrated control unit of an image forming system, the information may be conveyed directly from the input unit1001.

With reference toFIGS.15A to15G, operation for alignment and thermal compression bonding of legal-size sheets will now be described. The same description as the foregoing description of a sheet that is shorter than the heater portion will not be repeated.

Alignment Operation and Thermal Compression Bonding Operation: Length L2of Heater Portion<Sheet Length Ls

Each ofFIGS.15A to15Gis a schematic view of the alignment unit156as viewed from above in the Z direction. The illustration of the upper intermediate guide151and driving members/components, etc. of the thermal compression bonding unit167is omitted.

FIG.15Aillustrates a state in which the sheet S1, which is the first one, and the sheet S2, which is the second one, are being conveyed toward the alignment unit156. The moving unit159(the vertical alignment reference plate154and the vertical alignment roller153) have already moved to the standby position in accordance with the sheet size. The width alignment member155is waiting at a position located away in the-X direction from a sheet-stack-side-edge position so as not to be obstructive to the conveyance of the sheet stack.

FIG.15Billustrates a state in which the trailing edge of the sheet S1, the first one, has left the nip of the conveyance roller129, and the leading edge of the sheet S1has arrived at the vertical alignment roller153. The vertical alignment roller153has been lowered to a contact position in advance due to electric energization to the solenoid163and is being rotated by the drive motor161.

The sheet S1is transported toward the +Y side by the vertical alignment roller153and comes into contact with the vertical alignment reference plate154, thereby being aligned in the sheet conveyance direction. After that, each time the succeeding sheet S2to S5leaves the conveyance roller129, the sheet is transported toward the +Y side by the vertical alignment roller153and is brought into contact with the vertical alignment reference plate154, thereby being aligned in the sheet conveyance direction.

FIG.15Cillustrates a state in which each of the five sheets S1to S5has come into contact with the vertical alignment reference plate154, and the alignment of them in the sheet conveyance direction has completed.

At this point in time, the adhesive-use toner image39formed at the lower left corner portion of the sheet does not overlap with the pressing plate169in the Y direction.

FIG.15Dillustrates a state in which the sheets S1to S5have been moved in the-Y direction (the direction going toward the upstream side regarding the direction in which the sheet comes into the alignment unit156) by being pushed by the sheet contact portions154a,154b,and154c.This operation brings the adhesive-use toner image39selected to be at the lower left corner portion of the sheet to a position where it overlaps with the pressing plate169in the Y direction.

Even in a case where the sheet length Ls is greater than the length L2of the heater portion, if the adhesive-use toner image39already overlaps with the heating member171in the Y direction in the state illustrated inFIG.15C, the movement in the −Y direction illustrated inFIG.15Dis unnecessary.

FIG.15Eillustrates a state in which the sheets S1to S5have been moved in the +X direction by being pushed by the sheet pushing portions155a,155b,and155cof the width alignment member155. This operation brings the side edge of each of the sheets S1to S5into contact with the width alignment reference plates172aand172b, resulting in alignment in the sheet width direction.

FIG.15Fillustrates a state in which thermal compression bonding has been performed on the aligned sheets S1to S5by the heating member171.

FIG.15Gillustrates a state in which, in order to be ready for accepting the sixth and subsequent sheets, the width alignment member155has moved in the retracting direction (toward the −X side) and in which the vertical alignment reference plate154and the vertical alignment roller153have moved to the standby position in accordance with the sheet size. At this time, the sheets S1to S5after the thermal compression bonding are aligned in the sheet conveyance direction by being conveyed toward the +Y side and being brought into contact with the vertical alignment reference plate154by the vertical alignment roller153while being kept at the position of being in contact with the width alignment reference plates172aand172bin the X direction.

When the movement inFIG.15Dis performed, the stack holder flag150illustrated inFIG.16moves in such a way as to hold the sheets S1to S5having been moved in the-Y direction, thereby directing them toward an outgoing conveyance path203without a return to the incoming conveyance path202. Then, the same steps of alignment operation and thermal compression bonding operation as above are repeated as illustrated inFIGS.17A to17Ffor the sheets S6to S10.

Upon completion of thermal compression bonding of all of the sheets that make up one copy of a booklet, the booklet made up of the sheets S1to S10is pushed out by the vertical alignment reference plate154and is conveyed toward the pair of stack ejection rollers136(FIG.1) (toward the −Y side) regarding the sheet conveyance direction.

As explained above, with the configuration of the sheet processing apparatus according to the present embodiment, with the operation of the alignment unit according to the present embodiment, and with the thermal compression bonding according to the present embodiment, it is possible to provide a low-cost sheet processing apparatus by adopting a configuration in which the length L2of the heater portion is less than the maximum sheet length supported by the sheet processing apparatus, for example, the length of a legal-size sheet. With regard to every sheet size, even when the position of the adhesive-use toner image is selected to be a position of not overlapping with the heater portion, it is possible to create a booklet by adding an operation step of positioning the adhesive-use toner image39to the heating member171prior to thermal compression bonding.

Moreover, in the present embodiment, since a plurality of sheets S comes onto the lower intermediate guide152together through the buffer operation, it is possible to make the number of times of execution of the positioning of the adhesive-use toner image39to the heating member171in steps for creating one copy of a booklet less than the number of the sheets S that make up the booklet.

Therefore, a time loss incurred due to this operation step is minimal, and an effect on total time required for creating a booklet is small. Operation for Overlapping of Heater Portion and Adhesive-use Toner Image in Y Direction: Explanation of Other Methods

In the present embodiment, as an example, it has been described that the adhesive-use toner image39is brought to a position of overlapping with the heating member171in the Y direction by using a method of moving the sheet stack by moving the sheet contact portions154a,154b,and154cto push the sheet stack. However, any other method may be used. Specific examples of another method will be described below.

Method of Moving Heater Portion

FIG.18Aillustrates a state in which each of the five sheets S1to S5has come into contact with the vertical alignment reference plate154, and the alignment of them in the sheet conveyance direction has completed.

At this point in time, the adhesive-use toner image39selected to be at the lower left corner portion does not overlap with the heating member171in the Y direction.

FIG.18Billustrates a state in which the heating member171has moved in the +Y direction. This operation brings the heating member171to a position where it overlaps with, in the Y direction, the adhesive-use toner image39selected to be at the lower left corner portion.

Method of Moving Lower Intermediate Guide

FIG.19Aillustrates a state in which each of the five sheets S1to S5has come into contact with the vertical alignment reference plate154, and the alignment of them in the sheet conveyance direction has completed.

At this point in time, the adhesive-use toner image39selected to be at the lower left corner portion does not overlap with the heating member171in the Y direction.

FIG.19Billustrates a state in which the lower intermediate guide152has moved in the-Y direction together with the moving unit159, the width alignment member155, and the sheets S1to S5. This operation brings the adhesive-use toner image39selected to be at the lower left corner portion to a position where it overlaps with the heating member171in the Y direction.

Second Embodiment

Timing of Executing Movement Control: Explanation of Another Method

In the first embodiment, as an example, it has been described that the adhesive-use toner image39is brought to a position of overlapping with the heating member171in the Y direction by performing movement in the −Y direction by the sheet contact portions154a,154b,and154cafter the sheets S1to S5come onto the lower intermediate guide152. However, a similar effect may be obtained even if the timing of execution of the movement is before the sheets come. This will be explained in the present embodiment.

Alignment Operation and Thermal Compression Bonding Operation: Movement Before Sheets Come

Each ofFIGS.20A to20Fis a schematic view of the alignment unit156as viewed from above in the Z direction. In the present embodiment, the conveyance roller129is not located adjacent to the alignment unit156. The conveyance roller129and the alignment unit156are in a positional relationship illustrated inFIGS.20A to20F. Each sheet S illustrated inFIGS.20A to20Fhas a legal size. When the sheet S comes into the alignment unit156at the standby position to be described later, the trailing edge of the sheet S is located beyond the conveyance roller129.

The illustration of the upper intermediate guide151and driving members/components, etc. of the thermal compression bonding unit167is omitted.

FIG.20Aillustrates a state in which the sheet S1, which is the first one, and the sheet S2, which is the second one, are being conveyed toward the alignment unit156. The width alignment member155is waiting at a position located away in the −X direction from a sheet-stack-side-edge position so as not to be obstructive to the conveyance of the sheet stack. The moving unit159(the vertical alignment reference plate154and the vertical alignment roller153) starts moving to the standby position in accordance with the sheet size and in accordance with the position of the adhesive-use toner image39before the sheet S comes onto the lower intermediate guide152. This movement ensures that the adhesive-use toner image39will overlap with the pressing plate169at the point in time at which the sheet S comes.

FIG.20Billustrates a state in which the trailing edge of the sheet S1, the first one, has left the nip of the conveyance roller129, and the leading edge of the sheet S1has arrived at the vertical alignment roller153. The moving unit159(the vertical alignment reference plate154and the vertical alignment roller153), at this point in time, has already completed the movement to the standby position in accordance with the sheet size and in accordance with the position of the adhesive-use toner image39. The vertical alignment roller153has been lowered to a contact position in advance due to electric energization to the solenoid163and is being rotated by the drive motor161. The sheet S1is transported toward the +Y side by the vertical alignment roller153and comes into contact with the vertical alignment reference plate154, thereby being aligned in the sheet conveyance direction. After that, each time the succeeding sheet S2to S5leaves the conveyance roller129, the sheet is transported toward the +Y side by the vertical alignment roller153and is brought into contact with the vertical alignment reference plate154, thereby being aligned in the sheet conveyance direction.

FIG.20Cillustrates a state in which each of the five sheets S1to S5has come into contact with the vertical alignment reference plate154, and the alignment of them in the sheet conveyance direction has completed.

At this point in time, the adhesive-use toner image39selected to be at the lower left corner portion overlaps with the heating member171in the Y direction.

FIG.20Dillustrates a state in which the sheets S1to S5have been moved in the +X direction by being pushed by the sheet pushing portions155a,155b,and155cof the width alignment member155. This operation brings the side edge of each of the sheets S1to S5into contact with the width alignment reference plates172aand172b, resulting in alignment in the sheet width direction.

FIG.20Eillustrates a state in which thermal compression bonding has been performed on the aligned sheets S1to S5by the heating member171.

FIG.20Fillustrates a state in which, in order to be ready for accepting the sixth and subsequent sheets, the width alignment member155has moved in the retracting direction (toward the-X side). The vertical alignment reference plate154and the vertical alignment roller153remain at the standby position and do not move.

Then, the same steps of alignment operation and bonding operation as above are repeated for the sheets S6to S10.

Though a method of moving the sheet contact portions154a,154b,and154chas been described as an example of executing the movement before the sheets come, the same effect can be obtained also when a method of moving the heating member171or a method of moving the lower intermediate guide152is used, as described earlier with reference toFIGS.18and19. Moreover, it is possible to shorten the entire time taken for adhesive bonding by executing the movement at a timing that is before the sheets come.

Third Embodiment

Next, with reference toFIGS.21to24, operation of the alignment unit and thermal compression bonding according to a third embodiment will now be described. In the present embodiment, the same description as the foregoing description of the first embodiment will not be repeated. The sheet S is a legal-size sheet. The adhesive-use toner image39is formed thereon, and, as illustrated inFIG.21, the sheet length Ls is greater than the length L2of the heater portion, and the adhesive-use toner image39has a length substantially corresponding to the entire length of the sheet S in the longer-side direction of the sheet S. For this reason, a part of the area of the adhesive-use toner image39does not overlap with the heating member171in the Y direction. The adhesive bonding area pattern according to the present embodiment may be an adhesive bonding area pattern set when legal-size longer-side adhesive bonding is selected via the input unit1001illustrated inFIG.14.

When the adhesive-use toner image39is such a long image, if an area a, of the adhesive-use toner image39, not overlapping with the heating member171in the Y direction at a point in time of coming onto the lower intermediate guide152is moved to a position of overlapping therewith as illustrated inFIG.22B, an area β that was originally included in an overlapping portion but goes to a non-overlapping position due to this movement appears. For this reason, if the alignment unit behaves as having been described in the first embodiment, no thermal compression bonding will be performed at the area B. With reference toFIGS.23A to23H, alignment operation and thermal compression bonding operation will now be described. The same description as the foregoing description of a sheet that is shorter than the heater portion will not be repeated.

Alignment Operation and Thermal Compression Bonding Operation: Length L2of Heater Portion<Sheet Length Ls, Length of Adhesive-Use Toner Image

Each ofFIGS.23A to23His a schematic view of the alignment unit156as viewed from above in the Z direction. The illustration of the upper intermediate guide151and driving members/components, etc. of the thermal compression bonding unit167is omitted.

FIG.23Aillustrates a state in which the sheet S1, which is the first one, and the sheet S2, which is the second one, are being conveyed toward the alignment unit156. The moving unit159(the vertical alignment reference plate154and the vertical alignment roller153) have already moved to the standby position in accordance with the sheet size. The width alignment member155is waiting at a position located slightly outward of and away from a sheet-stack-side-edge position so as not to be obstructive to the conveyance of the sheet stack.

FIG.23Billustrates a state in which the trailing edge of the sheet S1, the first one, has left the nip of the conveyance roller129, and the leading edge of the sheet S1has arrived at the vertical alignment roller153. The vertical alignment roller153has been lowered to a contact position in advance due to electric energization to the solenoid163and is being rotated by the drive motor161. The sheet S1is transported toward the +Y side by the vertical alignment roller153and comes into contact with the vertical alignment reference plate154, thereby being aligned in the sheet conveyance direction. After that, each time the succeeding sheet S2to S5leaves the conveyance roller129, the sheet is transported toward the +Y side by the vertical alignment roller153and is brought into contact with the vertical alignment reference plate154, thereby being aligned in the sheet conveyance direction.

FIG.23Cillustrates a state in which each of the five sheets SI to S5has come into contact with the vertical alignment reference plate154, and the alignment of them in the sheet conveyance direction has completed. At this point in time, an adhesive-use toner image39aat the area a does not overlap with the heating member171in the Y direction, and an adhesive-use toner image39bat an area y overlaps with the heating member171in the Y direction.

FIG.23Dillustrates a state in which the sheets S1to S5have been moved in the +X direction by being pushed by the sheet pushing portions155a,155b,and155cof the width alignment member155. This operation brings the side edge of each of the sheets S1to S5into contact with the width alignment reference plates172aand172b, resulting in alignment in the sheet width direction.

FIG.23Eillustrates a state in which thermal compression bonding has been performed on the aligned sheets S1to S5by the heating member171. At this point in time, the adhesive-use toner image39bonly, which overlaps with the heating member171in the Y direction, has been bonded through thermal compression bonding, and the adhesive-use toner image39ahas not been bonded through thermal compression bonding yet.

FIG.23Fillustrates a state in which the sheets S1to S5have been moved in the-Y direction by being pushed by the sheet contact portions154a,154b,and154c.This operation brings the adhesive-use toner image39ato a position where it overlaps with the heating member171in the Y direction.

FIG.23Gillustrates a state in which thermal compression bonding has been performed on the aligned sheets S1to S5by the heating member171. In this step, the thermal compression bonding of the adhesive-use toner image39aat the area a, which was a yet-to-be-bonded part, completes, and thus the thermal compression bonding of the entire area of the adhesive-use toner image39finishes. Note that the area ω undergoes thermal compression bonding twice.

FIG.23Hillustrates a state in which, in order to be ready for accepting the sixth and subsequent sheets, the width alignment member155has moved in the retracting direction (toward the −X side) and in which the vertical alignment reference plate154and the vertical alignment roller153have moved to the standby position in accordance with the sheet size. At this time, the sheets S1to S5after the thermal compression bonding are aligned in the sheet conveyance direction by being conveyed toward the +Y side and being brought into contact with the vertical alignment reference plate154by the vertical alignment roller153while being kept at the position of being in contact with the width alignment reference plates172aand172bin the X direction. Then, the same steps of alignment operation and thermal compression bonding operation as above are repeated as illustrated inFIGS.24A to24Ffor the sheets S6to S10. Upon completion of thermal compression bonding of all of the sheets that make up one copy of a booklet, the booklet made up of the sheets S1to S10is pushed out by the vertical alignment reference plate154and is conveyed toward the pair of stack ejection rollers136(FIG.1) (toward the-Y side) regarding the sheet conveyance direction.

In the present embodiment, the sheet processing apparatus may be configured such that the sheet processing apparatus control unit1004acquires, or does not acquire, information about the position of the adhesive-use toner image39formed on the sheet S. In a case where the apparatus is configured to acquire this information, the heating member171may be moved in accordance with the position of the adhesive-use toner image39. In a case where the apparatus is configured not to acquire this information, the thermal compression bonding unit167may always apply heat and pressure to a sheet more than once when the sheet that is longer than the pressing plate169comes into the alignment unit156.

As explained above, with the configuration of the sheet processing apparatus according to the present embodiment, with the operation of the alignment unit according to the present embodiment, and with the thermal compression bonding according to the present embodiment, it is possible to provide a low-cost sheet processing apparatus by adopting a configuration in which the length L2of the heater portion is less than the maximum sheet length Ls supported by the sheet processing apparatus. Moreover, even in a case where the adhesive-use toner image39is formed in a range longer than the heat generation area168aalong a longer side on a sheet of the maximum size, it is possible to create a booklet by executing an operation step of positioning an yet-to-be-bonded area of the adhesive-use toner image39to the heating member171after the first execution of thermal compression bonding operation, followed by the second execution of thermal compression bonding operation. In the present embodiment, the number of times of execution of thermal compression bonding operation is not limited to twice. This may be executed more than twice. The number of times of execution of the operation step of positioning the area of the adhesive-use toner image39to the heating member171is not limited to once. This may be executed twice or more.

Operation for Overlapping of Heater Portion and Adhesive-use Toner Image in Y Direction: Other Methods

Though a method of moving the sheet contact portions154a,154b,and154chas been described as an example in the present embodiment, the same effect can be obtained also when a method of moving the heating member171or a method of moving the lower intermediate guide152is used, as described earlier with reference toFIGS.18and19.

Fourth Embodiment

Next, with reference toFIGS.25to28, operation of the alignment unit and thermal compression bonding according to a fourth embodiment will now be described. In the present embodiment, as illustrated inFIG.27, the thermal compression bonding unit167is disposed along the sheet width direction (X direction) at the downstream side of the lower intermediate guide152and is configured to perform thermal compression bonding at a side extending in the sheet width direction. As illustrated inFIG.25, the length L2of the heater portion is less than the maximum sheet width Ws supported by the sheet processing apparatus. In addition, the adhesive-use toner image is arbitrarily selectable within a range Wt that is greater in length than the length L2of the heater portion. Described in the present embodiment below with reference toFIGS.27A to27Dis operation for alignment and thermal compression bonding in a case where, as illustrated inFIG.26, the sheet width Ws is greater than the length L2of the heater portion and where the adhesive-use toner image39on the sheet at the point in time of having come onto the lower intermediate guide152does not overlap with the heating member171in the X direction.

Alignment Operation and Thermal Compression Bonding Operation: Thermal Compression Bonding Portion Disposed Along Sheet Width Direction

Each ofFIGS.27A to27Dis a schematic view of the alignment unit156as viewed from above in the Z direction. The illustration of the upper intermediate guide151and driving members/components, etc. of the thermal compression bonding unit167is omitted.

FIG.27Aillustrates a state in which the sheet S1, which is the first one, and the sheet S2, which is the second one, are being conveyed toward the alignment unit156. The width alignment member155is waiting at a position located slightly outward of and away from a sheet-stack-side-edge position so as not to be obstructive to the conveyance of the sheet stack.

FIG.27Billustrates a state in which the trailing edge of the sheet S1, the first one, has left the nip of the conveyance roller129, and the leading edge of the sheet S1has arrived at the vertical alignment roller153. The vertical alignment roller153has been lowered to a contact position in advance due to electric energization to the solenoid163and is being rotated by the drive motor161. The sheet S1is transported toward the +Y side by the vertical alignment roller153and comes into contact with a vertical alignment heater reference plate205, thereby being aligned in the sheet conveyance direction. After that, each time the succeeding sheet S2to S5leaves the conveyance roller129, the sheet is transported toward the +Y side by the vertical alignment roller153and is brought into contact with the vertical alignment heater reference plate205, thereby being aligned in the sheet conveyance direction.

FIG.27Cillustrates a state in which each of the five sheets S1to S5has come into contact with the vertical alignment heater reference plate205, and the alignment of them in the sheet conveyance direction has completed. At this point in time, the adhesive-use toner image39selected to be at the lower right corner portion does not overlap with the heating member171in the X direction.

FIG.27Dillustrates a state in which the sheets S1to S5have been moved in the +X direction by being pushed by the sheet pushing portions155a,155b,and155cof the width alignment member155. This operation brings the adhesive-use toner image39selected to be at the lower right corner portion to a position where it overlaps with the heating member171in the X direction. After this alignment, thermal compression bonding is performed on the five sheets S1to S5by the heating member171. Then, the same steps of alignment operation and thermal compression bonding operation as above are repeated for the sixth and subsequent sheets.

As explained above, with the configuration of the sheet processing apparatus according to the present embodiment, with the operation of the alignment unit according to the present embodiment, and with the thermal compression bonding according to the present embodiment, it is possible to provide a low-cost sheet processing apparatus by adopting a configuration in which the length L2of the heater portion is less than the maximum sheet width Ws supported by the sheet processing apparatus. Even when the position of the adhesive-use toner image on the sheet is selected to be a position of not overlapping with the heater portion, it is possible to create a booklet by adding an operation step of positioning the adhesive-use toner image39to the heating member171prior to thermal compression bonding. Even when the heating member171is disposed as in the configuration of the present embodiment and the length in the sheet width direction (width) of the area where the adhesive-use toner image39is formed is greater than the length L2of the heater portion, it is possible to perform shorter-side adhesive bonding by performing thermal compression bonding operation twice and by adding an operation step of positioning the adhesive-use toner image39to the heating member171prior to the second execution of thermal compression bonding as described earlier in the third embodiment.

Operation for Overlapping of Heater Portion and Adhesive-use Toner Image in X Direction: Explanation of Another Method

In the present embodiment, as an example, it has been described that the adhesive-use toner image39is brought to a position of overlapping with the heating member171in the X direction by using a method of moving the sheet stack by moving the sheet pushing portions155a,155b,and155cof the width alignment member155to push the sheet stack. However, a similar effect may be obtained even if another method is used. This will be explained below.

Method of Moving Heater Portion

FIG.28Aillustrates a state in which each of the five sheets S1to S5has come into contact with the vertical alignment heater reference plate205, and the alignment of them in the sheet conveyance direction has completed. At this point in time, the adhesive-use toner image39selected to be at the lower right corner portion does not overlap with the heating member171in the X direction.

FIG.28Billustrates a state in which the heating member171has moved in the −X direction. This operation brings the heating member171to a position where it overlaps with, in the X direction, the adhesive-use toner image39selected to be at the lower right corner portion.

Timing of Executing Movement Control: Another Method

In the present embodiment, as an example, it has been described that the adhesive-use toner image39is brought to a position of overlapping with the heating member171in the X direction by performing movement in the +X direction by the sheet pushing portions155a,155b,and155cof the width alignment member155after the sheets S1to S5come onto the lower intermediate guide152. However, as described earlier with reference toFIG.20, a similar effect may be obtained even if the timing of execution of the movement is before the sheets come.

Fifth Embodiment

With reference toFIG.29, an image forming apparatus200according to a fifth embodiment will now be described. The present embodiment is different from the first to fourth embodiments in that a printer body201(image forming apparatus body) has a configuration of a color printer configured to form a color image using toners of a plurality of colors. In the description below, unless otherwise specified, elements denoted by the same reference signs as those of the first to fourth embodiments are assumed to have substantially the same configurations and functions as those of the first to fourth embodiments, and differences from the first to fourth embodiments will be mainly explained.

An image forming section201B of the printer body201includes four process cartridges195y,195m,195c,and195kdisposed along the intermediate transfer belt108. The configuration of each of the process cartridges195y,195m,195c,and195kmay be substantially the same as the configuration of the process cartridge195according to the first and second embodiments, except for the difference in the toner contained therein.

The process cartridge195kforms a single-color image corresponding to a black component of a color image by using a black toner Tk. The process cartridge195yforms a single-color image corresponding to a yellow component of the color image by using a yellow toner Ty. The process cartridge195mforms a single-color image corresponding to a magenta component of the color image by using a magenta toner Tm. The process cartridge195cforms a single-color image corresponding to a cyan component of the color image by using a cyan toner Tc.

The single-color images formed by the process cartridges195y,195m,195c,and195krespectively are primarily transferred in such a way as to be superposed one on another on the intermediate transfer belt108and are thereafter secondarily transferred onto a sheet at the secondary transfer section. The other image forming operations performed by the printer body201are the same as those of the first to third embodiments.

The toner of at least one of the plurality of colors can be used as the toner for gluing sheets together. For example, it is possible to use the black toner Tk for dual purposes, one of which is a toner for recording an image on a sheet, and the other of which is a toner for adhesive bonding. In this case, the process cartridge195kforms a single-color image corresponding to a black component of a color image and forms the adhesive-use toner image39(FIG.2) that is to be transferred onto the adhesive bonding area of a sheet. When the image forming apparatus200creates a booklet, after toner images including the adhesive-use toner image39are formed on sheets at the printer body201, thermal compression bonding is performed at the sheet processing apparatus106to glue the sheets together. The same configuration as that of the first to third embodiments can be used for the sheet processing apparatus106.

Just with a single apparatus configuration, the image forming apparatus200according to the present embodiment is capable of performing color print processing and adhesive bonding processing. Using the thermal compression bonding portion described earlier in the first to third embodiments as the thermal compression bonding portion of the sheet processing apparatus106makes it possible to provide a low-cost sheet processing apparatus by adopting a configuration in which the length of the heater portion is less than the maximum sheet length supported by the sheet processing apparatus106. With regard to every sheet size, even when the position of the adhesive-use toner image is selected to be a position of not overlapping with the heater portion, it is possible to create a booklet by adding an operation step of positioning the adhesive-use toner image39to the heating member171prior to thermal compression bonding. Though a configuration of a tandem-type color printer including four process cartridges has been described as an example in the present embodiment, the number of toner types may be five or more, or three or less. In place of using the toner of at least one of the plurality of colors for dual purposes, one of which is a toner for recording an image on a sheet, and the other of which is a toner for adhesive bonding, a dedicated toner used exclusively for adhesive purpose may be adopted. In this case, the process cartridge using the dedicated toner exclusive for adhesive purpose only forms the adhesive-use toner image39(FIG.2) only. The dedicated toner exclusive for adhesive purpose only may be, for example, a transparent adhesive-use-only toner.

Additional Remarks

The embodiments having been described above discloses at least the following image forming system and the following sheet processing apparatus.

An image forming system, comprising:an image forming apparatus configured to form an image on a sheet; anda sheet processing apparatus configured to create a sheet stack by bonding a plurality of sheets together, the plurality of sheets being conveyed from the image forming apparatus, the sheet processing apparatus including a stacking unit, a thermal compression bonding unit, and a moving unit, the stacking unit including a stacking surface on which sheets with a layer of an adhesive formed thereon for bonding the sheets together are to be stacked, the thermal compression bonding unit including a heating member and a sheet cradle member, the heating member being elongated and including a heat generation area configured to heat the adhesive, the sheet cradle member facing the heating member, the thermal compression bonding unit sandwiching and heating the sheets stacked on the stacking unit between the heating member and the sheet cradle member, the thermal compression bonding unit bonding the plurality of sheets together by applying pressure while applying heat to the layer of the adhesive formed on the sheets by moving either one or both of the heating member, which is elongated, and the sheet cradle member, the moving unit moving either one or both of the sheets and the thermal compression bonding unit in a longer-side direction of the heating member, whereinthe layer of the adhesive is formed on the sheets by the image forming apparatus,a position of the layer of the adhesive formed on the sheets by the image forming apparatus is selectable in the longer-side direction of the heating member, andin a case where a length of the layer of the adhesive regarding the longer-side direction of the heating member is greater than a length of the heat generation area,an entire area of the layer of the adhesive on the sheets is heated and pressed by applying the heat and the pressure to the layer of the adhesive more than once while changing a relative position of the sheets having been conveyed onto the stacking unit and the heat generation area regarding the longer-side direction of the heating member by the moving unit.

The image forming system according to item 1, whereinthe heating member is a heater including a substrate and a heat generation resistor serving as the heat generation area formed on the substrate.

The image forming system according to item 1, whereinthe heating member includes a heater and a plate member, the heater including a substrate and a heat generation resistor serving as the heat generation area formed on the substrate, the plate member being heated by the heater and being in contact with the sheets.

The image forming system according to any of items 1 to 3, whereinthe sheets on an end portion of which the layer of the adhesive is formed are bonded together, the end portion being an end portion regarding a direction intersecting with the longer-side direction of the heating member.

The image forming system according to any of items 1 to 4, whereinthe longer-side direction of the heating member is along a direction in which the sheets are conveyed onto the stacking unit.

The image forming system according to any of items 1 to 4, whereinthe longer-side direction of the heating member is along a direction orthogonal to a direction in which the sheets are conveyed onto the stacking unit.

The image forming system according to any of items 1 to 6, whereinthe moving unit moves the sheets, andthe moving unit includes a restriction member configured to restrict movement ofthe sheet due to contact of a leading edge of the sheet conveyed onto the stacking unit, and the restriction member restricts the movement of the sheet due to the contact of the leading edge of the sheet when the sheet is conveyed onto the stacking unit.

The image forming system according to item 7, whereinin a case where, after creation of an already-bonded sheet stack by bonding a plurality of sheets together, a succeeding sheet is additionally bonded to the already-bonded sheet stack,a position where movement of the succeeding sheet conveyed onto the stacking unit is restricted by the restriction member is identical to a position where movement of each sheet of the already-bonded sheet stack conveyed onto the stacking unit is restricted by the restriction member.

The image forming system according to any of items 1 to 8, whereinthe layer of the adhesive is made of a powdery adhesive.

The image forming system according to item 9, wherein

the powdery adhesive is a toner.

An image forming system, comprising:an image forming apparatus configured to form an image on a sheet; anda sheet processing apparatus configured to create a sheet stack by bonding a plurality of sheets together, the plurality of sheets being conveyed from the image forming apparatus, the sheet processing apparatus including a stacking unit, a thermal compression bonding unit, and a moving unit, the stacking unit including a stacking surface on which sheets with a layer of an adhesive formed thereon for bonding the sheets together are to be stacked, the thermal compression bonding unit including a heating member and a sheet cradle member, the heating member being elongated and including a heat generation area configured to heat the adhesive, the sheet cradle member facing the heating member, the thermal compression bonding unit sandwiching and heating the sheets stacked on the stacking unit between the heating member and the sheet cradle member, the thermal compression bonding unit bonding the plurality of sheets together by applying pressure while applying heat to the layer of the adhesive formed on the sheets by moving either one or both of the heating member, which is elongated, and the sheet cradle member, the moving unit moving either one or both of the sheets and the thermal compression bonding unit in a longer-side direction of the heating member, whereinthe layer of the adhesive is formed on the sheets by the image forming apparatus, andin a case where a length of the layer of the adhesive regarding the longer-side direction of the heating member is less than a length of the heat generation area, before the sheets are heated and pressed, the moving unit moves either one or both of the sheets and the thermal compression bonding unit in advance in accordance with a sheet length so that an entire area of the layer of the adhesive overlaps with the heat generation area regarding the longer-side direction of the heating member when the sheets have been conveyed onto the stacking unit.

The image forming system according to item 11, whereinthe moving unit moves either one or both of the sheets and the thermal compression bonding unit in advance before a sheet trailing edge becomes stacked on the stacking surface.

The image forming system according to item 11 or 12, whereinthe moving unit moves the sheets, andthe moving unit includes a restriction member configured to restrict movement of the sheet due to contact of a leading edge of the sheet conveyed onto the stacking unit, and the restriction member restricts the movement of the sheet due to the contact of the leading edge of the sheet when the sheet is conveyed onto the stacking unit. (Item 14)

The image forming system according to item 13, whereinin a case where, after creation of an already-bonded sheet stack by bonding a plurality of sheets together, a succeeding sheet is additionally bonded to the already-bonded sheet stack,a position where movement of the succeeding sheet conveyed onto the stacking unit is restricted by the restriction member is identical to a position where movement of each sheet of the already-bonded sheet stack conveyed onto the stacking unit is restricted by the restriction member.

The image forming system according to any of items 11 to 14, wherein the layer of the adhesive is made of a powdery adhesive.

The image forming system according to item 15, wherein the powdery adhesive is a toner.

An image forming system, comprising:an image forming apparatus configured to form an image on a sheet; anda sheet processing apparatus configured to create a sheet stack by bonding a plurality of sheets together, the plurality of sheets being conveyed from the image forming apparatus, the sheet processing apparatus including a stacking unit, a thermal compression bonding unit, a moving unit, and a conveyance roller, the stacking unit including a stacking surface on which sheets with a layer of an adhesive formed thereon for bonding the sheets together are to be stacked, the thermal compression bonding unit including a heating member and a sheet cradle member, the heating member being elongated and including a heat generation area configured to heat the adhesive, the sheet cradle member facing the heating member, the thermal compression bonding unit sandwiching and heating the sheets stacked on the stacking unit between the heating member and the sheet cradle member, the thermal compression bonding unit bonding the plurality of sheets together by applying pressure while applying heat to the layer of the adhesive formed on the sheets by moving either one or both of the heating member, which is elongated, and the sheet cradle member, the moving unit moving either one or both of the sheets and the thermal compression bonding unit in a longer-side direction of the heating member, the conveyance roller being provided on a sheet conveyance path and conveying the sheets onto the stacking unit, whereinthe conveyance roller and the stacking unit are in such a positional relationship that, upon passing of a trailing edge of the sheet regarding a sheet conveyance direction through the conveyance roller when the sheet is conveyed onto the stacking unit, the trailing edge of the sheet becomes stacked on the stacking unit,the layer of the adhesive is formed on the sheets by the image forming apparatus, andin a case where a sheet length regarding the longer-side direction of the heating member is greater than a length of the heat generation area,and where a length of the layer of the adhesive regarding the longer-side direction of the heating member is less than the length of the heat generation area,and where the layer of the adhesive on the sheets has any area that does not overlap with the heat generation area regarding the longer-side direction of the heating member when the sheets have been conveyed onto the stacking unit, the thermal compression bonding unit heats and presses the layer of the adhesive after a positional alignment of the layer of the adhesive and the heat generation area is performed by changing a relative position of the sheets regarding the longer-side direction of the heating member and the heat generation area by the moving unit.

The image forming system according to item 17, whereinthe moving unit moves the sheets, andthe moving unit includes a restriction member configured to restrict movement of the sheet due to contact of a leading edge of the sheet conveyed onto the stacking unit, and the restriction member restricts the movement of the sheet due to the contact of the leading edge of the sheet when the sheet is conveyed onto the stacking unit.

The image forming system according to item 18, whereinin a case where, after creation of an already-bonded sheet stack by bonding a plurality of sheets together, a succeeding sheet is additionally bonded to the already-bonded sheet stack,a position where movement of the succeeding sheet conveyed onto the stacking unit is restricted by the restriction member is identical to a position where movement of each sheet of the already-bonded sheet stack conveyed onto the stacking unit is restricted by the restriction member.

The image forming system according to any of items 17 to 19, whereinthe layer of the adhesive is made of a powdery adhesive.

The image forming system according to item 20, whereinthe powdery adhesive is a toner.

A sheet processing apparatus, comprising:a stacking unit including a stacking surface on which sheets with a layer of an adhesive formed thereon for bonding the sheets together are to be stacked;a thermal compression bonding unit including a heating member and a sheet cradle member, the heating member being elongated and including a heat generation area configured to heat the adhesive, the sheet cradle member facing the heating member, the thermal compression bonding unit sandwiching and heating the sheets stacked on the stacking unit between the heating member and the sheet cradle member, the thermal compression bonding unit applying pressure while applying heat to the layer of the adhesive formed on the sheets by moving either one or both of the heating member, which is elongated, and the sheet cradle member;a moving unit configured to move either one or both of the sheets and the thermal compression bonding unit in a longer-side direction of the heating member; anda controller configured to control the sheet processing apparatus, whereinthe sheet processing apparatus bonds a plurality of sheets together by heating and pressing the layer of the adhesive formed on the sheets stacked on the stacking unit,the controller acquires information regarding the sheets on which the layer of the adhesive is formed, andin a case where a length of the layer of the adhesive regarding the longer-side direction of the heating member is greater than a length of the heat generation area and thus where an entire area of the layer of the adhesive formed on one side of a sheet is unable to be heated and pressed just by performing heating and pressing once,based on the information, the controller performs control to change a relative position of the sheets having been conveyed onto the stacking unit and the heat generation area regarding the longer-side direction of the heating member by the moving unit and to apply the heat and the pressure to the layer of the adhesive more than once, thereby heating and pressing an entire area of the layer of the adhesive on the sheet.

The sheet processing apparatus according to item 22, whereinthe controller acquires information regarding a sheet length and/or the length of the layer of the adhesive regarding the longer-side direction of the heating member.

The sheet processing apparatus according to item 22 or 23, whereinthe moving unit moves the sheets, andthe moving unit includes a restriction member configured to restrict movement of the sheet due to contact of a leading edge of the sheet conveyed onto the stacking unit, and the restriction member restricts the movement of the sheet due to the contact of the leading edge of the sheet when the sheet is conveyed onto the stacking unit.

The sheet processing apparatus according to item 24, whereinin a case where, after creation of an already-bonded sheet stack by bonding a plurality of sheets together, a succeeding sheet is additionally bonded to the already-bonded sheet stack,a position where movement of the succeeding sheet conveyed onto the stacking unit is restricted by the restriction member is identical to a position where movement of each sheet of the already-bonded sheet stack conveyed onto the stacking unit is restricted by the restriction member.

A sheet processing apparatus, comprising:a stacking unit including a stacking surface on which sheets with a layer of an adhesive formed thereon for bonding the sheets together are to be stacked;a thermal compression bonding unit including a heating member and a sheet cradle member, the heating member being elongated and including a heat generation area configured to heat the adhesive, the sheet cradle member facing the heating member, the thermal compression bonding unit sandwiching and heating the sheets stacked on the stacking unit between the heating member and the sheet cradle member, the thermal compression bonding unit applying pressure while applying heat to the layer of the adhesive formed on the sheets by moving either one or both of the heating member, which is elongated, and the sheet cradle member;a moving unit configured to move either one or both of the sheets and the thermal compression bonding unit in a longer-side direction of the heating member; anda controller configured to control the sheet processing apparatus, whereinthe sheet processing apparatus bonds a plurality of sheets together by heating and pressing the layer of the adhesive formed on the sheets stacked on the stacking unit,the controller acquires information regarding the sheets on which the layer of the adhesive is formed, andin a case where a length of the layer of the adhesive regarding the longer-side direction of the heating member is less than a length of the heat generation area, andbased on the information, the controller performs control to, before the sheets are heated and pressed, cause the moving unit to move either one or both of the sheets and the thermal compression bonding unit in advance in accordance with a sheet length so that an entire area of the layer of the adhesive overlaps with the heat generation area regarding the longer-side direction of the heating member when the sheets have been conveyed onto the stacking unit.

The sheet processing apparatus according to item 26, whereinthe controller acquires information regarding a sheet length and information regarding the length of the layer of the adhesive regarding the longer-side direction of the heating member.

The sheet processing apparatus according to item 26 or 27, whereinthe moving unit moves the sheets, andthe moving unit includes a restriction member configured to restrict movement of the sheet due to contact of a leading edge of the sheet conveyed onto the stacking unit, and the restriction member restricts the movement of the sheet due to the contact of the leading edge of the sheet when the sheet is conveyed onto the stacking unit.

The sheet processing apparatus according to item 28, whereinin a case where, after creation of an already-bonded sheet stack by bonding a plurality of sheets together, a succeeding sheet is additionally bonded to the already-bonded sheet stack,a position where movement of the succeeding sheet conveyed onto the stacking unit is restricted by the restriction member is identical to a position where movement of each sheet of the already-bonded sheet stack conveyed onto the stacking unit is restricted by the restriction member.

A sheet processing apparatus, comprising:a stacking unit including a stacking surface on which sheets with a layer of an adhesive formed thereon for bonding the sheets together are to be stacked;a thermal compression bonding unit including a heating member and a sheet cradle member, the heating member being elongated and including a heat generation area configured to heat the adhesive, the sheet cradle member facing the heating member, the thermal compression bonding unit sandwiching and heating the sheets stacked on the stacking unit between the heating member and the sheet cradle member, the thermal compression bonding unit applying pressure while applying heat to the layer of the adhesive formed on the sheets by moving either one or both of the heating member, which is elongated, and the sheet cradle member;a moving unit configured to move either one or both of the sheets and the thermal compression bonding unit in a longer-side direction of the heating member;a controller configured to control the sheet processing apparatus; anda conveyance roller provided on a sheet conveyance path and configured to convey the sheets onto the stacking unit, whereinthe sheet processing apparatus bonds a plurality of sheets together by heating and pressing the layer of the adhesive formed on the sheets stacked on the stacking unit,the controller acquires information regarding the sheets on which the layer of the adhesive is formed,the conveyance roller and the stacking unit are in such a positional relationship that, upon passing of a trailing edge of the sheet regarding a sheet conveyance direction through the conveyance roller when the sheet is conveyed onto the stacking unit, the trailing edge of the sheet becomes stacked on the stacking unit, andin a case where a sheet length regarding the longer-side direction of the heating member is greater than a length of the heat generation area,and where a length of the layer of the adhesive regarding the longer-side direction of the heating member is less than the length of the heat generation area,and where the layer of the adhesive on the sheets has any area that does not overlap with the heat generation area regarding the longer-side direction of the heating member when the sheets have been conveyed onto the stacking unit,based on the information, the controller causes the moving unit to perform a positional alignment of the layer of the adhesive and the heat generation area by changing a relative position of the sheets regarding the longer-side direction of the heating member and the heat generation area and thereafter causes the thermal compression bonding unit to heat and press the layer of the adhesive.

The sheet processing apparatus according to item 30, whereinthe controller acquires information regarding a sheet length and information regarding the length of the layer of the adhesive regarding the longer-side direction of the heating member.

The sheet processing apparatus according to item 30 or 31, whereinthe moving unit moves the sheets, andthe moving unit includes a restriction member configured to restrict movement of the sheet due to contact of a leading edge of the sheet conveyed onto the stacking unit, and the restriction member restricts the movement of the sheet due to the contact of the leading edge of the sheet when the sheet is conveyed onto the stacking unit.

The sheet processing apparatus according to item 32, whereinin a case where, after creation of an already-bonded sheet stack by bonding a plurality of sheets together, a succeeding sheet is additionally bonded to the already-bonded sheet stack,a position where movement of the succeeding sheet conveyed onto the stacking unit is restricted by the restriction member is identical to a position where movement of each sheet of the already-bonded sheet stack conveyed onto the stacking unit is restricted by the restriction member.

With the present disclosure, it is possible to provide an image forming system and a sheet processing apparatus configured to create a stack of sheets bonded together by applying heat and pressure properly to a layer of an adhesive formed on a sheet when creating the sheet stack the length of which is greater than the length of the heat generation area of a heater.

This application claims the benefit of Japanese Patent Application No. 2023-040809. filed Mar. 15, 2023, which is hereby incorporated by reference herein in its entirety.