Image forming apparatus and image forming system

Abstract

To provide an image forming apparatus allowing for selectively containing moisture in a bind region by a simple configuration.SOLUTION: An image forming apparatus, allowed to feed a plurality of sheets images are formed to a post processor for pressurizing / deforming bind regions of the bundled, plurality of sheets into pressure-binding, comprises a carrier unit that carries a sheet, an image forming unit that ejects liquid ink toward the sheet carried by the carrier unit, and a controller that controls the operations of the carrier unit and image forming unit. The controller repeatedly executes processing of allowing the carrier unit to carry the sheet up to a position faced to the image forming unit, the image forming unit to form an image on the sheet by ejecting liquid ink onto it, and the carrier unit to carry the sheet on which the image is formed toward the post processor. The controller furthermore allows the image forming unit to apply liquid ink to a bind region in at least one of the plurality of sheets.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to an image forming apparatus and an image forming system.

Background Art

[0002] Conventionally, a system including an image forming apparatus that forms an image on a sheet of paper and a post-processing apparatus that binds a plurality of sheets of paper on which an image has been formed by the image forming apparatus into a bundle (hereinafter referred to as a "sheet bundle") is known. In recent years, from the viewpoints of resource saving and ecology, there has been an increase in post-processing apparatuses capable of performing so-called "pressure bonding binding" in which a sheet bundle is pressure-deformed with uneven binding teeth instead of a binding process using needles.

[0003] In pressure bonding binding, there is a problem that as the number of sheets of paper constituting the sheet bundle increases, it becomes more difficult for the binding teeth to bite into the sheet bundle, and appropriate binding cannot be performed. Therefore, there is a technique of including water in a region on the sheet where the binding teeth come into contact (hereinafter referred to as the "binding region") (see, for example, Patent Document 1). In this way, by performing pressure bonding binding after weakening the hydrogen bond connection of the paper by adding water, the bond by pressure bonding binding becomes stronger.

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique of Patent Document 1, in addition to the image forming means for forming an image, it is necessary to provide means for applying water to the binding region, so the configuration of the image forming apparatus becomes complicated. Further, since water with low viscosity spreads on the paper, the image formed on the paper may bleed due to the water applied to the binding region.

[0005] The present invention has been made to solve such problems, and an object thereof is to provide an image forming apparatus having a simple configuration and capable of selectively including moisture in a binding region.

Means for Solving the Problems

[0006] In order to solve the above problems, one aspect of the present invention is an image forming apparatus that supplies a plurality of sheets on which an image is formed to a post-processing apparatus that pressurizes and deforms a binding area of a plurality of bundled sheets to perform pressure binding, the image forming apparatus including a conveyance unit that conveys sheets, an image forming unit that discharges liquid ink toward the sheets conveyed by the conveyance unit, and a controller that controls operations of the conveyance unit and the image forming unit. The controller causes the conveyance unit to convey a sheet to a position facing the image forming unit, causes the image forming unit to discharge liquid ink to form an image on the sheet, and repeatedly executes a process of causing the conveyance unit to convey the sheet on which the image is formed toward the post-processing apparatus. The controller further causes the image forming unit to apply liquid ink to at least one of the binding areas of the plurality of sheets. The longer the conveyance distance from the position facing the image forming unit to the post-processing device, or the longer the conveyance time of the paper from the position facing the image forming unit to the post-processing device, the greater the amount of liquid ink applied to the binding area. It is characterized by this.

Effect of the Invention

[0007] According to the present invention, an image forming apparatus having a simple configuration and capable of selectively containing moisture in the binding area can be obtained.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0009] Hereinafter, the image forming system 1 according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the overall configuration of the image forming system 1. The image forming system 1 has a function of forming an image on a plurality of sheets of paper and binding the plurality of sheets on which the image is formed into a bundle. As shown in FIG. 1, the image forming system 1 is composed of an image forming apparatus 2 and a post-processing apparatus 3.

[0010] FIG. 2 is a diagram showing the internal structure of the image forming apparatus 2. The image forming apparatus 2 repeatedly executes a process of forming an image on a sheet of paper using liquid ink and discharging the sheet of paper on which the image is formed to the post-processing apparatus 3. As shown in FIG. 2, the image forming apparatus 2 mainly includes a paper feeding unit 10, a conveyance unit 20, and an image forming unit 30.

[0011] The paper feeding unit 10 holds a sheet of paper before an image is formed and feeds the held sheet of paper to the conveyance unit 20. The paper feeding unit 10 mainly includes, for example, a paper feeding cassette 11, a separation roller 12, a friction pad 13, a manual feed tray 14, and a pickup roller 15. Note that the image forming apparatus 2 shown in FIG. 2 is provided with a plurality of sets of the paper feeding cassette 11, the separation roller 12, and the friction pad 13, but one set may be sufficient. Also, the manual feed tray 14 and the pickup roller 15 may be omitted.

[0012] The paper feed cassette 11 stores sheets of paper stacked before an image is formed. The separation roller 12 rotates while being in contact with the topmost sheet of paper stored in the paper feed cassette 11, thereby feeding the sheet of paper out to the main conveyance path P1. The friction pad 13 separates the sheets of paper fed out by the separation roller 12 one by one. The manual feed tray 14 supports sheets of paper manually inserted by the user of the image forming system 1. The pickup roller 15 rotates while sandwiching the sheet of paper supported by the manual feed tray 14, thereby feeding the sheet of paper out to the main conveyance path P1.

[0013] The conveyance unit 20 conveys the sheets of paper fed from the paper feed unit 10. The conveyance unit 20 includes, for example, a plurality of pairs of conveyance rollers 21a to 21j, and switching claws 22 and 23. The pairs of conveyance rollers 21a to 21j convey the sheet of paper along the conveyance path by rotating while sandwiching the sheet of paper. The switching claws 22 and 23 are disposed at the branch point of the two conveyance paths and switch which of the two conveyance paths the sheet of paper conveyed by the pairs of conveyance rollers 21a to 21j is guided to.

[0014] Inside the image forming apparatus 2, a main conveyance path P1, a reverse conveyance path P2, and a paper discharge conveyance path P3 are formed. The main conveyance path P1, the reverse conveyance path P2, and the paper discharge conveyance path P3 are spaces through which the sheet of paper can pass. The main conveyance path P1 is a path that extends from the paper feed cassette 11 and the manual feed tray 14 through a position facing the recording head 32 to the post-processing device 3. The reverse conveyance path P2 is a path that branches from the main conveyance path P1 on the downstream side in the sheet conveyance direction from the recording head 32 and merges into the main conveyance path P1 on the upstream side in the sheet conveyance direction from the recording head 32. Further, the reverse conveyance path P2 is a path that guides the sheet of paper with an image recorded on its surface to a position facing the recording head 32 again after inverting the front and back. The paper discharge conveyance path P3 is a path that branches from the main conveyance path P1 on the downstream side in the sheet conveyance direction from the recording head 32 and leads to the paper discharge tray 24.

[0015] The conveying roller pairs 21a to 21d are arranged on the main conveying path P1 at a predetermined interval in the conveying direction. The conveying roller pairs 21e to 21h are arranged on the reverse conveying path P2 at a predetermined interval in the conveying direction. The conveying roller pairs 21i to 21j are arranged on the paper discharge conveying path P3 at a predetermined interval in the conveying direction. That is, the sheet is conveyed along the main conveying path P1 by the conveying roller pairs 21a to 21d, conveyed along the reverse conveying path P2 by the conveying roller pairs 21e to 21h, and conveyed along the paper discharge conveying path P3 by the conveying roller pairs 21i to 21j.

[0016] The switching claw 22 is arranged at the branch point between the main conveying path P1 and the reverse conveying path P2. And the switching claw 22 switches whether to guide the sheet conveyed along the main conveying path P1 to the reverse conveying path P2. The switching claw 23 is arranged at the branch point between the main conveying path P1 and the paper discharge conveying path P3. And the switching claw 23 switches whether to guide the sheet conveyed along the main conveying path P1 to the paper discharge conveying path P3.

[0017] The image forming unit 30 adopts an inkjet method of forming an image on the sheet by discharging liquid ink toward the sheet conveyed on the main conveying path P1. Also, the image forming unit 30 can form a color image by combining liquid inks of a plurality of colors (for example, black, cyan, magenta, yellow). Further, the liquid ink is, for example, dye ink or pigment ink. The image forming unit 30 mainly includes, for example, a cartridge mounting portion 31 and a recording head 32.

[0018] In the cartridge mounting portion 31, ink cartridges 33B, 33C, 33M, and 33Y that contain liquid inks of different colors are independently detachable. Further, the cartridge mounting portion 31 supplies liquid ink of each color from the mounted ink cartridges 33B, 33C, 33M, and 33Y to the recording head 32. The recording head 32 includes a plurality of nozzles that eject the liquid ink of each color supplied from the cartridge mounting portion 31. That is, the nozzles are formed on the surface facing the main conveyance path P1 of the recording head 32. Note that the colors of the ink may include white, gold, silver, etc. in addition to black, cyan, magenta, and yellow.

[0019] That is, the liquid ink stored in the ink cartridges 33B, 33C, 33M, and 33Y gradually decreases as it is ejected from the recording head 32. Therefore, the image forming unit 30 includes remaining amount sensors 34B, 34C, 34M, and 34Y (see FIG. 5). The remaining amount sensors 34B, 34C, 34M, and 34Y detect the remaining amount of the liquid ink stored in each of the ink cartridges 33B, 33C, 33M, and 33Y mounted on the cartridge mounting portion 31 (hereinafter referred to as "ink remaining amount"), and output a remaining amount signal indicating the detected ink remaining amount to the controller 100 (see FIG. 5). The remaining amount sensors 34B, 34C, 34M, and 34Y are realized by, for example, well-known optical sensors.

[0020] The image forming apparatus 2 may further include a reading unit 40. The reading unit 40 reads an image recorded on a document and generates image data indicating the read image. The reading unit 40 reads the image with a CCD (Charge Coupled Device) or the like. Further, the reading unit 40 may include an ADF (Auto Document Feeder) 41 that causes a plurality of documents to be read by the CCD in order.

[0021] FIG. 3 is a diagram showing the internal structure of the post-processing device 3. The post-processing device 3 performs post-processing on the paper on which an image is formed by the image forming device 2. The post-processing device 3 according to the present embodiment performs a so-called "pressure bonding binding" in which a bundle of a plurality of papers on which an image is formed (hereinafter referred to as "paper bundle") is pressure-deformed and bound without using a needle. The post-processing device 3 mainly includes, for example, conveyance roller pairs 51 to 55, an internal tray 61, discharge trays 71 and 72, a branch claw 81, and binding processing units 91 and 92.

[0022] The conveyance roller pairs 51 to 55 convey the paper supplied from the image forming device 2 inside the post-processing device 3. The internal tray 61 temporarily supports the paper bundle on which post-processing is to be performed. The discharge tray 71 supports the paper on which post-processing is not performed. The discharge tray 72 supports the paper bundle after the post-processing is performed. The branch claw 81 switches whether to guide the paper conveyed by the conveyance roller pairs 51 to 52 to either the internal tray 61 or the discharge tray 71. More specifically, the branch claw 81 guides the paper on which post-processing is to be performed to the internal tray 61 and guides the paper on which post-processing is not to be performed to the discharge tray 71.

[0023] The position of the paper bundle supported by the internal tray 61 in the conveyance direction is aligned by the end fence 66, and the position in the width direction orthogonal to the conveyance direction is aligned by the side fence 68. Then, the binding processing units 91 and 92 perform pressure bonding binding on the paper bundle aligned by the end fence 66 and the side fence 68.

[0024] FIG. 4 is a schematic diagram showing the configuration of the binding processing units 91 and 92. As shown in FIG. 4, the binding processing units 91 and 92 include a first member 93 and a second member 94. The first member 93 and the second member 94 are arranged to face each other in the thickness direction of the paper bundle with the paper bundle supported by the internal tray 61 interposed therebetween. On the surfaces of the first member 93 and the second member 94 facing each other, binding teeth having an uneven shape in which concave portions and convex portions are alternately formed are formed. Further, the binding teeth of the first member 93 and the second member 94 are formed with the concave portions and the convex portions shifted so as to mesh with each other.

[0025] In the process of supplying a plurality of sheets that make up a stack of sheets to the inner tray 61, as shown in FIG. 4(A), the first member 93 and the second member 94 are spaced apart from each other. Then, when all the sheets that make up the stack of sheets are supported by the inner tray 61, as shown in FIG. 4(B), the binding teeth of the first member and the second member 94 mesh with each other, and the stack of sheets is pressure-deformed in the thickness direction. As a result, the stack of sheets supported by the inner tray 61 is pressure-bound. Further, the pressure-bound stack of sheets is discharged to the discharge tray 72 by the discharge claw 67 and the pair of conveyance rollers 55. Furthermore, the amount of the stack of sheets supported by the discharge tray 72 is detected by the filler 82.

[0026] Note that, on the sheet, the region pressure-deformed by the first member 93 and the second member 94 is defined as the "binding region". That is, the binding region is a region on the sheet corresponding to the shape and size of the binding teeth of the first member 93 and the second member 94. Also, the binding region exists on the front and back surfaces of the sheet. The binding region is, for example, a rectangle having a long side and a short side.

[0027] The binding processing units 91 and 92 are arranged spaced apart in the width direction of the stack of sheets. Also, the binding processing units 91 and 92 may be configured to be movable along the outer edge of the stack of sheets supported by the inner tray 61 or to be able to change the angle. That is, the post-processing device 3 may be capable of performing pressure binding on one or more binding regions of the stack of sheets supported by the inner tray 61.

[0028] Furthermore, the post-processing device 3 may be capable of performing a so-called "center binding process" of binding the center of the stack of sheets. In this case, the post-processing device 3 further includes a pair of conveyance rollers 56 to 59, a discharge tray 73, a center binding processing unit 83, a sheet folding blade 84, a stopper 85, and a sheet folding plate 86.

[0029] The plurality of sheets conveyed by the conveying roller pairs 56 to 58 are stapled at the center by the center stapling unit 83. The stack of sheets stapled at the center is further conveyed by the conveying roller pairs 56 to 58 until the leading end abuts against the stopper 85. The stack of sheets that has abutted against the stopper 85 is folded in half by the sheet folding blade 84 and the sheet folding plate 86, and is discharged to the discharge tray 73 by the conveying roller pair 59.

[0030] FIG. 5 is a hardware configuration diagram of the image forming system 1. As shown in FIG. 5, the image forming system 1 includes a configuration in which a CPU (Central Processing Unit) 101, a RAM (Random Access Memory) 102, a ROM (Read Only Memory) 103, an HDD (Hard Disk Drive) 104, and an I / F 105 are connected via a common bus 109.

[0031] The CPU 101 is an arithmetic means and controls the operation of the entire image forming system 1. The RAM 102 is a volatile storage medium capable of high-speed reading and writing of information, and is used as a work area when the CPU 101 processes information. The ROM 103 is a non-volatile read-only storage medium in which programs such as firmware are stored. The HDD 104 is a non-volatile storage medium capable of reading and writing information and having a large storage capacity, and stores an OS (Operating System), various control programs, application programs, and the like.

[0032] The image forming system 1 processes, by means of the arithmetic function provided by the CPU 101, a control program stored in the ROM 103, an information processing program (application program) loaded from a storage medium such as the HDD 104 into the RAM 102, and the like. By this processing, a software control unit including various functional modules of the image forming system 1 is configured. A functional block for realizing the functions of the image forming system 1 is configured by the combination of the software control unit configured in this way and the hardware resources mounted on the image forming system 1. That is, the CPU 101, the RAM 102, the ROM 103, and the HDD 104 constitute a controller 100 that controls the operation of the image forming system 1.

[0033] The I / F 105 is an interface that connects the paper feeding unit 10, the conveyance unit 20, the image forming unit 30, the reading unit 40, the post-processing device 3, and the operation panel 110 to the common bus 109. Then, the controller 100 forms an image indicated by image data on a sheet by controlling the paper feeding unit 10, the conveyance unit 20, and the image forming unit 30 through the I / F 105. Further, the controller 100 controls the post-processing device 3 to bundle and press-bind a plurality of sheets supplied from the image forming device 2.

[0034] Note that FIG. 5 illustrates an example in which the image forming device 2 and the post-processing device 3 are controlled by a common controller 100. However, a controller for controlling the image forming device 2 and a controller for controlling the post-processing device 3 may be provided independently and operate in cooperation with each other.

[0035] The operation panel 110 includes an operation unit that receives operations from the user and a display that notifies the user of information. The operation unit includes, for example, hard keys, a touch panel superimposed on the display, and the like. Then, the operation panel 110 acquires information from the user through the operation unit and provides information to the user through the display.

[0036] FIG. 6 is a diagram showing variations in the specific structure of the image forming system. The image forming systems 1, 1A, and 1B shown in FIGS. 1 and 6 are common in that they include an image forming apparatus 2 and a post-processing apparatus 3, but the arrangements of the image forming apparatus 2 and the post-processing apparatus 3 are different.

[0037] In the image forming system 1 shown in FIG. 1, the image forming apparatus 2 and the post-processing apparatus 3 are provided with independent housings. The image forming apparatus 2 and the post-processing apparatus 3 are installed side by side in the left-right direction and are connected to each other. On the other hand, in the image forming systems 1A and 1B shown in FIG. 6, the image forming apparatus 2 and the post-processing apparatus 3 are housed in a common housing. Further, FIG. 6(A) is an example of a tower-type housing with a high height in the vertical direction, and FIG. 6(B) is an example of a small housing assumed to be placed on a desktop.

[0038] Therefore, in the image forming systems 1, 1A, and 1B, the paper conveyance distance from the image forming apparatus 2 to the post-processing apparatus 3 (more specifically, the internal tray 61 from the position facing the image forming unit 30) is different. More specifically, the conveyance distance from the position facing the image forming unit 30 to the internal tray 61 is L for the image forming system 1 1 for the image forming system 1A 2 for the image forming system 1B 3 and L 1 > L 2 > L 3 That is.

[0039] FIG. 7 shows data examples of various tables stored in the HDD 104. The HDD 104 stores, for example, a conveyance distance table shown in FIG. 7(A) and a paper thickness table shown in FIG. 7(B). Note that the conveyance distance table and the paper thickness table may be stored in the RAM 102 or the ROM 103 instead of the HDD 104.

[0040] As shown in FIG. 7(A), the conveyance distance table holds the model number of the image forming system 1 in association with the conveyance distance of the paper from the position facing the image forming unit 30 to the internal tray 61. For example, the model number of the image forming system 1 shown in FIG. 1 is "AAA", the model number of the image forming system 1A shown in FIG. 6(A) is "BBB", and the model number of the image forming system 1B shown in FIG. 6(B) is "CCC". The controller 100 can, for example, read the model numbers of the image forming systems 1, 1A, and 1B from the ROM 103 and read the conveyance distance corresponding to the read model number from the conveyance distance table.

[0041] As shown in FIG. 7(B), the paper thickness table holds the paper type, which is the type of paper for forming an image, in association with the paper thickness. For example, the paper thickness T of thin paper 1 , the paper thickness T of medium-thick paper 2 , and the paper thickness T of thick paper 3 have the relationship of T 1 <T 2 <T 3 . As an example, the controller 100 acquires the paper type from the user through the operation panel 110. As another example, the controller 100 acquires the paper type associated with the paper feed cassette 11 at the paper feed source. Then, the controller 100 can acquire the paper thickness corresponding to the acquired paper type from the paper thickness table.

[0042] FIG. 8 is an example of a display of a pressure binding mode setting screen. The controller 100 causes the display of the operation panel 110 to display the pressure binding mode setting screen shown in FIG. 8. The pressure binding mode setting screen is a screen that accepts the designation of the paper type "paper type" for performing pressure binding (in other words, forming an image), the location "binding location (i.e., binding area)" on the paper bundle where pressure binding is performed, and the color "ink color" of the liquid ink applied to the binding area. Note that the controller 100 may accept the designations of the paper type, binding location, and ink color through separate screens.

[0043] The crimp binding mode setting screen includes a [thin paper] icon, a [medium-thick paper] icon, and a [thick paper] icon as icons for accepting the specification of paper types. The [thin paper] icon corresponds to crimp binding a bundle of thin paper. The [medium-thick paper] icon corresponds to crimp binding a bundle of medium-thick paper. The [thick paper] icon corresponds to crimp binding a bundle of thick paper.

[0044] Also, the crimp binding mode setting screen includes a [one location] icon, a [two locations] icon, and a [other] icon as icons for accepting the specification of binding locations. The [one location] icon corresponds to setting one location at the upper left corner of the paper bundle as the binding area. The [two locations] icon corresponds to setting two locations spaced in the width direction of the upper side of the paper bundle as the binding area. The [other] icon corresponds to allowing the user to specify the binding area on the paper bundle on the display.

[0045] Furthermore, the crimp binding mode setting screen includes an [ink eco] icon, a [black] icon, a [cyan] icon, a [magenta] icon, a [yellow] icon, and a [other] icon as icons for accepting the specification of colors. The [ink eco] icon corresponds to using the liquid ink in the ink cartridge with the most ink remaining among the ink cartridges 33B, 33C, 33M, and 33Y mounted in the cartridge mounting portion 31. The [black] icon, [cyan] icon, [magenta] icon, and [yellow] icon correspond to using the liquid ink of the corresponding color. The [other] icon corresponds to allowing the user to specify a combination of liquid inks of each color.

[0046] The controller 100 receives operations for specifying the paper type, binding location, and ink color through the operation unit. Then, the controller 100 stores the paper type, binding location, and ink color specified through the crimp binding mode setting screen in the RAM 102. This process is executed prior to the crimp binding process described later.

[0047] FIG. 9 is a flowchart of the pressure-binding process. The pressure-binding process is a process of causing a post-processing device 3 to perform pressure-binding on a bundle of a plurality of sheets on which an image has been formed by an image forming apparatus 2. The controller 100 may receive image data indicating an image to be formed on each of the plurality of sheets from an external device (e.g., a PC) through a communication interface, or may cause the reading unit 40 to read a document and generate the image data. Further, the controller 100 causes the user to specify through the operation unit whether to form an image only on the front surface of the sheet or to form an image on both the front and back surfaces of the sheet.

[0048] First, the controller 100 forms an image on the front surface of the sheet by executing an image forming process (front surface) (S901). Next, the controller 100 determines whether there is an image to be formed on the back surface of the sheet (S902). Then, when the controller 100 determines that there is an image to be formed on the back surface of the sheet (S902: Yes), the controller 100 forms an image on the back surface of the sheet by executing an image forming process (back surface) (S903). On the other hand, when the controller 100 determines that there is no image to be formed on the back surface of the sheet (S902: No), the process of step S903 is skipped.

[0049] Next, the controller 100 determines whether images have been formed on all the sheets to be pressure-bound (S904). Then, when the controller 100 determines that there are still sheets on which images are to be formed (S904: No), the processes after step S901 are executed again. That is, the controller 100 repeatedly executes the processes of steps S901 to S903 to form images on all the sheets to be pressure-bound.

[0050] When the controller 100 determines that images have been formed on all sheets (S904: Yes), it causes the post-processing device 3 to perform pressure binding (S905). That is, the controller 100 moves the binding processing units 91 and 92 to the binding position specified through the pressure binding mode setting screen, and pressurizes and deforms the stack of sheets supported by the internal tray 61 with the first member 93 and the second member 94. Further, the controller 100 discharges the pressure-bound stack of sheets to the discharge tray 72 by the discharge claw 67 and the pair of conveyance rollers 55.

[0051] FIG. 10 is a flowchart of the image forming process. The image forming process (front side) and the image forming process (back side) shown in FIG. 9 share the processes shown in FIG. 10, and the operations of the paper feeding unit 10 and the conveyance unit 20 are different. Therefore, first, the image forming process (front side) will be described in detail, and then the processes specific to the image forming process (back side) will be described.

[0052] First, in the image forming process (front side), the controller 100 causes the conveyance unit 20 to convey the paper fed from the paper feeding unit 10 to a position facing the recording head 32. Next, the controller 100 forms an image indicated by the image data on the front surface of the paper by discharging liquid ink from the recording head 32 toward the facing paper (S1001).

[0053] Next, the controller 100 determines whether the image formed in step S1001 overlaps the binding area specified through the pressure binding mode setting screen (S1002). When the controller 100 determines that the image overlaps the binding area (S1002: Yes), it skips the processes after step S1003. On the other hand, when the controller 100 determines that the image does not overlap the binding area (S1002: No), it executes the processes after step S1003. That is, the controller 100 executes an ink amount setting process described later with reference to FIG. 11.

[0054] Next, the controller 100 determines whether the "ink eco" mode is specified through the crimp binding mode setting screen (S1004). Then, when the controller 100 determines that the "ink eco" mode is specified (S1004: Yes), among the ink cartridges 33B, 33C, 33M, and 33Y of each color mounted on the cartridge mounting portion 31, the liquid ink in the ink cartridge with the most ink remaining is applied to the binding area specified through the crimp binding mode setting screen (S1005).

[0055] More specifically, the controller 100 identifies the ink cartridge with the most remaining ink based on the remaining amount signals output from the respective remaining amount sensors 34B, 34C, 34M, and 34Y. Then, the controller 100 discharges the ink in the identified ink cartridge toward the binding area to the recording head 32.

[0056] On the other hand, when the controller 100 determines that the "ink eco" mode is not specified (S1004: No), it applies the liquid ink of the color selected or combined through the crimp binding mode setting screen to the binding area specified through the crimp binding mode setting screen (S1006). That is, the controller 100 combines one or more of the liquid inks stored in the ink cartridges 33B, 33C, 33M, and 33Y and discharges them toward the binding area to the recording head 32. Also, in steps S1005 and S1006, the controller 100 applies the amount of liquid ink set in the ink amount setting process to the binding area.

[0057] Next, when the controller 100 determines that there is no image to be formed on the back surface of the paper (S902: No), it switches the switching claw 22 so that the paper passes through the main conveyance path P1, and conveys the paper with the image formed thereon to the conveyance unit 20 toward the post-processing device 3. On the other hand, when the controller 100 determines that there is an image to be formed on the back surface of the paper (S902: Yes), it switches the switching claw 22 so that the paper is guided to the reverse conveyance path P2, and conveys the paper with the image formed thereon to the conveyance unit 20 along the reverse conveyance path P2.

[0058] Also, in the image forming process (back side), the controller 100 causes the transport unit 20 to transport the sheet whose front and back sides are transported through the reverse transport path P2 to a position facing the recording head 32. Next, the controller 100 executes the processes of steps S1001 to S1006 in FIG. 10. Then, the controller 100 switches the switching claw 22 so that the sheet passes through the main transport path P1, and transports the sheet on which the image has been formed to the transport unit 20 toward the post-processing device 3.

[0059] FIG. 11 is a flowchart of the ink amount setting process. The ink amount setting process is a process of setting the amount of liquid ink applied to the binding area (hereinafter referred to as "application amount") in steps S1005 and S1006 in FIG. 10. More specifically, the ink amount setting process A shown in FIG. 10(A) is a process of setting the application amount based on the paper thickness T of the sheet and the number N of sheets constituting the sheet bundle. Further, the ink amount setting process B shown in FIG. 10(B) is a process of setting the application amount based on the transport distance L. The controller 100 executes one or both of the ink amount setting processes A and B in step S1003 in FIG. 10.

[0060] First, in the ink amount setting process A, the controller 100 specifies the paper thickness T of the sheets constituting the sheet bundle based on the paper thickness table (S1101). Also, the controller 100 specifies the number N of sheets constituting the sheet bundle based on the acquired image data (S1102). Then, the controller 100 calculates the product (T × N) of the specified paper thickness T and the number N, and compares it with a predetermined first threshold value TH 1 (S1103).

[0061] Then, when T × N is greater than or equal to the first threshold value TH 1 (S1103: Yes), the controller 100 sets the application amount for the binding area to the first amount A1 (S1004). On the other hand, when T × N is less than the first threshold value TH 1If it is less (S1103: No), the coating amount for the binding area is set to the second amount A2 (S1005). Note that A1 > A2. That is, the controller 100 increases the coating amount as the paper thickness T increases and increases the coating amount as the number of sheets N increases. Note that the controller 100 may increase or decrease the coating amount based on only one of the paper thickness T and the number of sheets N.

[0062] Also, in the ink amount setting process B, the controller 100 specifies the conveyance distance L of the paper from the position facing the recording head 32 to the internal tray 61 based on the conveyance distance table (S1106). Then, the controller 100 compares the specified conveyance distance L with a predetermined second threshold value TH 2 (S1107).

[0063] Then, when the conveyance distance L is greater than or equal to the second threshold value TH 2 (S1107: Yes), the coating amount for the binding area is set to the third amount A3 (S1008). On the other hand, when the conveyance distance L is less than the second threshold value TH 2 (S1107: No), the coating amount for the binding area is set to the fourth amount A4 (S1009). Note that A3 > A4. That is, the controller 100 increases the coating amount as the conveyance distance L increases.

[0064] Note that the controller 100 may adjust the coating amount based on the conveyance time of the paper from the position facing the recording head 32 to the internal tray 61 instead of the conveyance distance L. That is, the controller 100 may increase the coating amount for the binding area as the conveyance time increases.

[0065] According to the above embodiment, for example, the following operational effects are achieved.

[0066] According to the above-described embodiment, the liquid ink is applied to the binding area of the sheet using the image forming unit 30 that forms an image on the sheet. As a result, there is no need to separately provide a means for applying water to the binding area, so that the process of adding water to the binding area can be realized with a simple configuration. Further, by using a liquid ink having a higher viscosity than water, it is possible to suppress a decrease in quality such as the liquid ink applied to the binding area spreading outside the binding area and the image bleeding.

[0067] Further, according to the above-described embodiment, since the application amount of the liquid ink to the binding area is adjusted based on the paper thickness T, the number of sheets N, the conveyance distance L, etc., it is possible to perform pressure binding with a desired binding force. Further, by adjusting the application amount based on the conveyance time, it is possible to prevent the liquid ink from drying before the pressure binding is performed.

[0068] Further, according to the above-described embodiment, when forming an image only on the front surface of the sheet, it is possible to prevent a decrease in throughput by omitting the application of the liquid ink to the binding area on the back surface. On the other hand, when forming images on both the front and back surfaces of the sheet, by applying the liquid ink to the binding areas on the front and back surfaces, the application amount of the liquid ink to the sheet increases, so that the binding force is further improved.

[0069] Further, according to the above-described embodiment, the color of the liquid ink applied to the binding area can be changed. Therefore, for example, if a color close to the background color of the sheet is selected, after the sheet bundle is pressure-bound, the liquid ink applied to the binding area becomes less noticeable.

[0070] Further, according to the above-described embodiment, by adopting the "eco-ink" mode, it is possible to apply a liquid ink with a small usage amount (≒ a large remaining ink amount) to the binding area. As a result, it is possible to prevent the consumption amount of a specific color liquid ink from becoming extremely large and to use the liquid ink efficiently. As a result, the running cost of the image forming systems 1, 1A, and 1B can be reduced.

[0071] Further, according to the above embodiment, when an image is formed in the binding area, application of the liquid ink to the binding area is omitted. Thereby, it is possible to prevent the original image from being modified and to prevent ink in an amount greater than a desired application amount from being applied to the binding area. As another example, the controller 100 may make the determination in step S1002 before forming an image on the paper. Then, when the controller 100 determines that an image overlaps the binding area, the controller 100 may not form an image in a predetermined area including the binding area and may apply liquid ink to the binding area. Further, the controller 100 may receive, through the operation unit, an operation of a user for switching a control mode when an image overlaps the binding area.

[0072] Further, according to the above embodiment, prior to forming an image on the paper, the user is made to specify the position and number of the binding areas, so that even when pressure binding is performed with a plurality of binding areas, the binding force can be appropriately controlled.

[0073] [Modification Example] Note that, in the above embodiment, an example in which the same amount of liquid ink is applied to the binding areas of all the papers constituting the paper bundle has been described. However, the controller 100 may change the application amount of the liquid ink for each paper. For example, the controller 100 may reduce the application amount to the papers located on both outer sides (i.e., the front cover and the back cover) of the paper bundle and increase the application amount to the papers located inside the paper bundle. Thereby, it is possible to prevent the liquid ink from adhering to the binding processing units 91 and 92 and to prevent the liquid ink applied to the binding area from being conspicuous.

[0074] Further, in the above embodiment, an example in which liquid ink is applied to the binding areas of all the papers constituting the paper bundle has been described. However, the controller 100 may apply liquid ink to the binding areas of at least one of the plurality of papers constituting the paper bundle. For example, the controller 100 may apply liquid ink only to the binding area of the paper that is finally supplied to the post-processing device 3.

[0075] In addition, in the above-described embodiment, an example of adjusting the application amount of the liquid ink to the binding area based on parameters such as the paper thickness T, the number of sheets N, the conveyance distance L, and the conveyance time has been described. However, the application amount of the liquid ink to the binding area may be specified by the user. FIG. 12(A) is an example of a display of an ink application amount adjustment screen. The controller 100 causes the display to display the ink application amount adjustment screen shown in FIG. 12(A). Then, the controller 100 receives an operation of the user who specifies the application amount for each basis weight of the paper through the operation unit. Note that the basis weight refers to the weight per unit area of the paper [g / m 2 . And in steps S1005 and S1006 of FIG. 10, the controller 100 may apply the liquid ink in the application amount specified in advance through the ink application amount adjustment screen to the binding area.

[0076] In addition, in the above-described embodiment, an example of applying the liquid ink to the entire binding area has been described, but the liquid ink may be selectively applied to a part of the binding area. FIG. 12(B) is an example of a display of an ink application range adjustment screen. The controller 100 causes the display to display the ink application range adjustment screen shown in FIG. 12(B). Then, the controller 100 receives an operation of the user who specifies the range to which the liquid ink is to be applied within the binding area through the operation unit. In the example of FIG. 12(B), the user is allowed to select one of four settings with different application ranges. Then, in steps S1005 and S1006 of FIG. 10, the controller 100 may apply the liquid ink to the range specified in advance through the ink application range adjustment screen within the binding area.

[0077] Setting 1 is a setting for applying the liquid ink to the entire binding area. Setting 2 is a setting for applying the liquid ink only to both ends of the binding area. Setting 3 is a setting for applying the liquid ink only to the central portion of the binding area. Setting 4 is a setting for applying the liquid ink to a plurality of ranges spaced apart in the longitudinal direction of the binding area. By narrowing the range to which the liquid ink is applied within the binding area, the binding force of the pressure binding can be reduced. Thereby, it becomes easy to release the binding of the paper bundle later.

[0078] Furthermore, the control method described above may be implemented by, for example, a program or the like. That is, the control method is a method executed by a computer in which an arithmetic unit, a storage device, an input device, an output device, and a control device operate in cooperation based on a program. Further, the program may be written in a storage device, a storage medium, or the like and distributed, or distributed through an electric communication line or the like.

[0079] Note that the present invention is not limited to the embodiments exemplified above, and various modifications are possible without departing from the technical gist thereof, and all technical matters included in the technical idea described in the claims are the subject of the present invention. The above embodiments show preferred examples, but those skilled in the art can realize various modified examples from the disclosed content. Such modified examples are also included in the technical scope described in the claims.

Explanation of Reference Numerals

[0080] 1, 1A, 1B: Image forming system 2: Image forming apparatus 3: Post-processing apparatus 10: Paper feeding unit 11: Paper feed cassette 12: Separation roller 13: Friction pad 14: Manual feed tray 15: Pickup roller 20: Conveying unit 21a~21j, 51~59: Pair of conveying rollers 22, 23: Switching claws 24: Paper discharge tray 30: Image forming unit 31: Cartridge mounting part 32: Recording head 33B, 33C, 33M, 33Y: Ink cartridges 34B, 34C, 34M, 34Y: Remaining amount sensors 40: Reading unit 61: Internal tray 66: End Fence 67: Ejection Claw 68: Side Fence 71, 72, 73: Discharge Tray 81: Branch Claw 82: Filler 83, 91, 92: Binding Processing Unit 84: Paper Folding Blade 85: Stopper 86: Paper Folding Plate 93: First Member 94: Second Member 100: Controller 101: CPU 102: RAM 103: ROM 104: HDD 105: I / F 109: Common Bus 110: Operation Panel

Prior Art Documents

Patent Documents

[0081]

Patent Document 1

Claims

1. An image forming apparatus that supplies a plurality of sheets on which an image is formed to a post-processing apparatus that pressure-bonds and binds a binding area of the plurality of bundled sheets by applying pressure deformation, comprising: a conveyance unit that conveys the sheets; an image forming unit that discharges liquid ink toward the sheets conveyed by the conveyance unit; a controller that controls operations of the conveyance unit and the image forming unit, wherein the controller causes the conveyance unit to convey a sheet to a position facing the image forming unit, causes the image forming unit to discharge liquid ink to form an image on the sheet, repeatedly executes a process of causing the conveyance unit to convey the sheet on which the image is formed toward the post-processing apparatus, wherein the controller further causes the image forming unit to apply liquid ink to at least one of the binding areas of the plurality of sheets, and increases the amount of liquid ink applied to the binding area as the conveyance distance from the position facing the image forming unit to the post-processing apparatus is longer or as the sheet conveyance time from the position facing the image forming unit to the post-processing apparatus is longer. An image forming apparatus characterized by this.

2. An image forming apparatus that supplies a plurality of sheets on which an image is formed to a post-processing apparatus that pressure-bonds and binds a binding area of the plurality of bundled sheets by applying pressure deformation, comprising: a conveyance unit that conveys the sheets; an image forming unit that discharges liquid ink toward the sheets conveyed by the conveyance unit; a controller that controls operations of the conveyance unit and the image forming unit, wherein the controller causes the conveyance unit to convey a sheet to a position facing the image forming unit, causes the image forming unit to discharge liquid ink to form an image on the sheet, repeatedly executes a process of causing the conveyance unit to convey the sheet on which the image is formed toward the post-processing apparatus, wherein the image forming unit is capable of discharging liquid ink of a plurality of colors, a cartridge mounting portion to which a plurality of ink cartridges each containing liquid ink of a different color are detachably attached, a recording head that discharges the liquid ink in the plurality of ink cartridges mounted on the cartridge mounting portion, and a remaining amount sensor that detects the remaining amount of ink in each of the plurality of ink cartridges mounted on the cartridge mounting portion, wherein the controller further causes the image forming unit to apply liquid ink selected from a plurality of colors or liquid ink combining a plurality of colors to at least one of the binding areas of the plurality of sheets. An image forming apparatus, characterized in that liquid ink in the ink cartridge with the largest detected ink remaining amount detected by the remaining amount sensor is ejected from the recording head toward the binding area of the paper.

3. An image forming apparatus that supplies a plurality of papers on which images have been formed to a post-processing apparatus that pressure-deforms and pressure-binds the binding areas of the bundled plurality of papers, a conveyance unit that conveys the paper, an image forming unit that ejects liquid ink toward the paper conveyed by the conveyance unit, and a controller that controls the operations of the conveyance unit and the image forming unit, wherein the controller conveys the paper to a position facing the image forming unit, forms an image on the paper by ejecting liquid ink from the image forming unit, repeatedly executes a process of conveying the paper on which the image has been formed to the conveyance unit toward the post-processing apparatus, wherein the controller further applies liquid ink from the image forming unit to at least one of the binding areas of the plurality of papers, and omits the application of liquid ink to the binding area when the image formed on the paper overlaps the binding area. An image forming apparatus characterized by this.

4. The controller applies liquid ink from the image forming unit to the binding area of each of the plurality of papers. The image forming apparatus according to any one of claims 1 to 3, characterized by this.

5. The controller increases the application amount of liquid ink to the binding area as the number of papers to be pressure-bound increases. The image forming apparatus according to any one of claims 1 to 4, characterized by this.

6. The controller increases the application amount of liquid ink to the binding area as the thickness of the paper increases. The image forming apparatus according to any one of claims 1 to 5, characterized by this.

7. The image forming unit can form images on both the front and back surfaces of the paper, wherein the controller applies liquid ink only to the binding area on the front surface of the paper to be formed with an image only on the front surface from the image forming unit, and applies liquid ink to the binding areas on the front and back surfaces of the paper to be formed with images on both the front and back surfaces from the image forming unit. The image forming apparatus according to any one of claims 1 to 6, characterized by this.

8. It is provided with an operation unit that receives an operation for designating the position of one or more of the binding areas. The image forming apparatus according to any one of claims 1 to 7, wherein the controller causes the image forming unit to apply liquid ink to one or more of the binding areas specified through the operation unit.

9. The apparatus comprises an operation unit that receives an operation for specifying a range for applying liquid ink to the binding area, The image forming apparatus according to any one of claims 1 to 8, wherein the controller causes the image forming unit to apply liquid ink to a range specified through the operation unit among the binding areas.

10. An image forming system comprising the image forming apparatus according to any one of claims 1 to 9, and a post-processing apparatus that bundles a plurality of sheets supplied from the image forming apparatus and performs pressure binding in the binding area.

Images