Paper folding device and paper folding method

Abstract

To provide a sheet folding device for improving the folding by heating a first roller pair and a second roller pair during a folding action and a sheet folding method.SOLUTION: The sheet folding device of the embodiment comprises a pair of heating rollers having a parallel rotational shaft, and comprises: a first roller pair having a nip formed between the pair of heating rollers; a first motor drive part for rotating the first roller pair so that the carried sheet passes through the nip of the first roller to form a folding part; a second roller pair having the pair of heating rollers having the parallel rotational shaft and positioned so that the rotational shaft of the pair of heating rollers is vertical to the rotational shaft of the first roller pair and the folding part of the sheet having left the nip abuts on the nip by the pair of heating rollers; a second motor drive part for rotating the second roller pair along the folding part; and a control part for controlling the action of the first motor drive part and the second motor drive part.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a paper folding device and a paper folding method. [Background technology]

[0002] Document processing devices include printers, copiers, scanners, and email gateways, among others. More recently, multi-function devices that use two or more of these functions have been installed in office environments. These machines are referred to as multi-function peripherals (MFPs or MFDs). MFPs as used herein are understood to include printers, either alone or in combination with others of the aforementioned functions. It should further be understood that any suitable document processing device may be used.

[0003] MFPs can be fitted with document finishers that provide functions such as collating, punching, or stapling. Finishers may be built into the MFP or provided as accessories that are attached to the MFP. Finishers can include automatic formation of booklets. This can be accomplished by a special N-up printing technique called saddle stitching, so named because the collated sheets are draped over a saddle-like device during the stapling / stitching process. In saddle stitching, one of the folded sheets is folded inside the other and then stapled through the fold line with wire staples. The sheets pass through the folded crease from the outside and are folded between the center-most pages. Two staples are commonly used, but larger books may require more staples along the spine. Saddle stitching is formed with a group of four images oriented on each printed sheet, two images on the front and two images on the back. The printed images are sequenced so that the pages will appear in the desired order when the booklet is formed by stapling and folding. In this process, the booklet pages are half the size of the paper used. In the United States, using 8 1 / 2" x 17" sheets creates an 8 1 / 2" x 11" booklet. When resized in ISO216, an A3 size paper (420mm x 297mm) becomes an A4 (210mm x 297mm) booklet.

[0004] Saddle stitching works best for binding booklets or publications with around 64 pages or less. Books with more pages may be bulky when folded and may not lie as flat as desired when saddle stitched. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-157247 [Patent Document 2] Japanese Patent Application Publication No. 05-238638 [Patent Document 3] JP 2007-84324 A Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE DISCLOSURE The problem to be solved by the invention is to provide a paper folding apparatus and method that improves folding by applying heat to a primary roller pair and a secondary roller pair during the folding operation. [Means for solving the problem]

[0007] The paper folding device of the embodiment has a pair of heating rollers having parallel rotation axes, a primary roller pair in which a nip is formed between the pair of heating rollers, and a folding unit that rotates the primary roller pair so that a folded portion is formed along a crease when a paper is fed through the nip of the primary roller pair. vinegar a pair of heating rollers having parallel rotation axes, the rotation axes of the pair of heating rollers being perpendicular to the rotation axis of the primary roller pair, and a pair of secondary rollers positioned so that the folded portion of the paper leaving the nip abuts against the nip formed by the pair of heating rollers; and a motor driving unit for rotating the pair of secondary rollers along the folded portion. vinegar a control unit that controls the operation of the first motor driving unit and the second motor driving unit; A piston means attached to one of the secondary roller pair separates the secondary roller pair or brings the secondary roller pair into contact with each other under low pressure until the folded portion is positioned at the nip, and when the folded portion is positioned at the nip, pressure is applied to the folded portion of the secondary roller pair, and in this state, the secondary roller pair is caused to travel along the fold by a second motor drive unit. It is characterized by:

[0008] Various embodiments are better understood with reference to the following description, the appended claims, and the accompanying drawings. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an exemplary configuration of a multifunction peripheral to which a finisher according to an embodiment is attached. [Diagram 2]FIG. 1 illustrates an exemplary configuration of networked digital devices that may comprise a document rendering system, such as a multifunction peripheral, in accordance with an embodiment. [Diagram 3] FIG. 2 is a diagram illustrating a first exemplary configuration of a paper folding device according to an embodiment. [Figure 4] 1A-1C illustrate exemplary configurations for folding a reinforced saddle-stitched booklet according to an embodiment. [Diagram 5] FIG. 13 is a diagram illustrating a second exemplary configuration of the paper folding device according to the embodiment. [Figure 6] 6 is a diagram showing a state when the cam of the paper folding device shown in FIG. 5 is set to a first position. [Figure 7] 6 is a diagram showing a state when the cam of the paper folding device shown in FIG. 5 is set to a second position. FIG. [Figure 8] 1 illustrates an exemplary embodiment of a secondary roller mechanism according to an embodiment. [Figure 9] 1A-1D illustrate an exemplary embodiment of a roller heater according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The apparatus, system, and method disclosed herein are described in detail with reference to the drawings, but these are merely examples. The disclosed and described examples, arrangements, configurations, components, elements, apparatus, device methods, systems, etc. may be modified as appropriate, and modifications may occur for a given implementation, as would be easily understood by a person skilled in the art. The specific technical methods, arrangements, etc. disclosed herein are either specific examples of presentation, or merely general descriptions of such technical methods, arrangements, etc. Anything defined based on a specific description or example is essential or limited unless otherwise specified.

[0011] In a saddle stapler, the creases can become too rounded, especially if the page count is high or the paper stock is thick. Sharper creases can be stacked with less cumulative volume, creating a more aesthetically pleasing and functional booklet. Saddle staple finishers staple the sheets along a direction in which the paper is folded in half, typically twice, to create a booklet. The stack of paper is then folded and discharged into a collection tray. Examples herein apply heat to the rollers for folding to "set" the paper into the fold, potentially eliminating the need for a secondary roller or intensifier roller. In embodiments that retain an intensifier roller, the intensifier roller can also be heated to allow more pages to be folded more effectively. The application of heat can be selectively done to the primary roller pair and the secondary roller pair or intensifier fold roller as needed.

[0012] 1 is a diagram illustrating an embodiment of a multi-function peripheral (MFP) 104 having an attached finisher 108. The finisher 108 includes a finishing unit 112 that performs functions such as collating, stapling, punching, or saddle stitching.

[0013] 2 shows an embodiment of a networked digital device that is comprised of a document rendering system 200 contained within an MFP, such as MFP 104 of FIG. 1. MFP 104 includes an intelligent controller 201 that is itself a computer system. Controller 201 includes one or more processors, as indicated by processor CPU 202. Processor CPU 202 can suitably access non-volatile memory, such as read only memory ROM 204, random access memory RAM 206, etc., via data bus 212.

[0014] The processor CPU 202 can also be in data communication with a storage interface (I / F) 208 for reading and writing data to storage 216, which may suitably consist of a hard disk, optical disk, solid state disk, cloud-based storage, or any other data storage.

[0015] The processor CPU 202 is also in data communication with a network interface 210 that provides an interface to a network interface controller (NIC) 214. The network interface controller 214 provides a wired data path via any suitable wired or physical network bus 220 or a wireless data path via a wireless network interface such as Wi-Fi 218. Examples of wireless connections include cellular, Wi-Fi, wireless universal serial bus (wireless USB), satellite, and the like. Examples of wired interfaces include Ethernet, USB, IEEE 1394 (FIREWIRE), LIGHTNING, telephone line, and the like. The processor CPU 202 is also in data communication with a hardware monitor 221 that suitably accumulates status data from subassemblies, sensors, digital thermometers, and the like, suitably including digital status data including device codes such as device error codes. The processor CPU 202 can also be in data communication with a document processor interface 222 via a data path 212 with a Bluetooth interface 226 and an NFC interface 228.

[0016] The processor CPU 202 may also be in data communication with a suitable user interface 234 that provides data communication with user peripherals such as a display, keyboard, mouse, trackball, touch screen, etc.

[0017] 2, MFP functional unit 250 includes a copy engine, suitably configured from copy hardware 240, a scan engine, suitably configured from scan hardware 242, a printer engine, suitably configured from printer hardware 244, and a fax engine, suitably configured from fax hardware 246. These subsystems together comprise MFP functional unit 250. It will be appreciated that MFP functional unit 250 may suitably comprise an intelligent unit including any suitable hardware or software platform.

[0018] FIG. 3 is a functional diagram of an exemplary embodiment of a booklet folding system (paper folder) 300 suitable for use in conjunction with a paper folding operation in a document finisher. As mentioned above, the paper folder 300 cannot be used for documents with a large number of pages, with a typical limit being 64 pages. With larger booklets, the booklet tends to bend at the fold lines, preventing the booklet from being flat as would otherwise be desired. According to the embodiment of FIG. 3, heat is applied to the booklet's sheets as the booklet is folded to allow for a flatter fold area with a higher page count or to use a heavier stock paper. The folding consists of a first and a second folding operation using rollers moving in different directions relative to the fold area of ​​the booklet. In this example, the received paper sheet 304 includes a fold 308 on its centerline. One or more staples are suitably applied to the fold 308. The paper sheet 304 consists of two or more sheets that form the booklet. The paper 304, preceded by a crease 308, is fed into a pair of opposing rotating rollers 312, 316 (primary roller pair) at a nip 320. When the paper crease 308 encounters the nip 320, the booklet is pinched between the rotating rollers 312, 316. The combined pressure between the rotating rollers 312, 316 then causes the crease 308 to fold, where the halves of the booklet meet on the center page. The crease 308 is guided into the nip 320 by a folding blade 324 that extends along the inside of the crease 308. The folding blade 324 can retract once the crease 308 is gripped by the rotating rollers 312, 316. Alternatively, the folding blade 324 can extend into the nip 320 before retracting. The sheet 304' then passes through rotating rollers 312, 316 where folding is completed as the trailing edge is discharged to the nip exit 322. The rotating rollers 312, 316 are rotationally powered by a suitable motor or combination of motors, such as motor drives 328, 332 (first motor drives). Drive control of the motor drives 328, 332 is suitably accomplished by a microcontroller 336.

[0019] In the embodiment of FIG. 3, the rotating rollers 312, 316 further include heating elements (hereinafter simply referred to as heaters) 340, 344 therein, respectively. Suitable resistive, inductive, or radiative heating may be used as the heaters 340, 344, specific examples of which are described below. The use of heat by the heaters 340, 344 allows the paper fibers to soften to form, and when the paper cools, tighter folds remain, similar to ironing a garment. The optimum temperature depends on several factors, including the number of folded sheets, the thickness of the paper, and the rotational speed of the rollers. A slower rotational speed of the rotating rollers 312, 316 will allow more heat to build up over time, and a higher temperature may cause the paper 304 to burn. A higher roller temperature may be used when a faster roller rotation is used for the rotating rollers 312, 316. Additionally, the folds are subjected to appropriate pressure during rolling, which also affects the desired roller temperature. Thus, the particular selection of pressure, temperature, and roller speed is application specific.

[0020] The position of the paper 304' as shown in FIG. 3 is suitably controlled and determined by the use of a stepper motor positioned by the microcontroller 336. Alternatively, the position of the paper 304' may be accomplished by a suitable sensor, such as via a sensor 346. The folded edge 308' of the paper 304' is moved towards another pair of rollers 348, 352 (a secondary roller pair). The roller pair 348, 352 are oriented to roll at a 90 degree angle relative to the rotating rollers 312, 316. A piston 356 is provided on the upper surface of one of the rollers 348. The roller pair 348, 352 are suitably separated from each other or contact each other with a relatively low pressure, such as by control of the piston 356 (or a solenoid), until the paper 304' is located between a point such as the folded edge 308'. The pressure from the piston 356 is suitably controlled by the microcontroller 336 with an eccentric bearing or cam, as described in more detail below. At the folding edge 308', pressure is applied to the paper 304' by the piston 356, and the roller pair 348, 352 travels along the crease edge 308' to provide further enhanced crease compression. Heaters 349, 353 are provided inside the roller pair 348, 352 to further enhance the effectiveness of the secondary fold. In the second fold by the roller pair 348, 352, the paper fibers that are differently aligned in the paper are subjected to heat and pressure at multiple orientations for more effective folding. In a specific embodiment, the initial load pressure between the secondary roller pair of the roller pair 348, 352 is equivalent to a weight of 1,362 grams (approximately 3 pounds or 13.3 Newtons). The enhanced pressure during folding is equivalent to an added force of 536 grams (approximately 1.2 pounds or 5.2 Newtons) for a total pressure of approximately 4.2 pounds or 18.6 Newtons. Roller pairs 48, 352 are driven by motors, such as motor drives 360, 364, respectively, which are comprised of stepper motors that are driven and controlled by microcontroller 336. Once the booklet is completely folded, it is properly ejected from folder 300.

[0021] FIG. 4 is a flow chart 400 illustrating a method of operation of the enhanced saddle stitch booklet folding, suitably including two temperature enhanced crease rolling operations, of the folder 300 shown in FIG. The process begins at block 404 and proceeds to block 408 where two or more sheets of paper are fed into the saddle stapler. Next, at block 412, the sheets are stacked and aligned. Next, at block 416, the sheets are stapled along their centerlines. Next, at block 420, the sheets are aligned centerline to the folding blade 324. Next, at block 424, a determination is made as to whether the sheets would benefit from roller heating using heaters 340, 344, 349, 353. If so (Yes at block 424), then, at block 426, the microcontroller 336 heats the heaters 340, 344, 349, 353 of the primary roller pair (roller pair 312, 316) and the secondary roller pair (roller pair 348, 352) before the sheet 304 is introduced. If it is determined in block 424 that heating is not beneficial (No in block 424) or if roller heating is performed in block 426, the process proceeds to block 432. In block 432, the folding blade 324 is actuated to form a crease along the centerline of the sheet 304 and to push the sheet 304 along the crease into the nip 320 of the primary roller pair 312, 316. The primary roller pair 312, 316 is driven to rotate by a microcontroller 336. Once the folded portion of the sheet 304 sandwiched between the primary roller pair 312, 316 passes through the primary roller pair 312, 316, the microcontroller 336 deactivates the heaters 340, 344 of the primary roller pair 312, 316 in block 436 as roller heating is not required. This can save energy for roller heating and avoid possible damage or discoloration of the outer sheets forming the cover of the booklet. The microcontroller 336 may initialize the pressure of the piston 356 applied to the folded portion of the secondary roller pair 348, 352 when the paper 304 is located a predetermined distance past the primary roller pair 312, 316. The set pressure 356 is applied for a period of time corresponding to the number of pages of the paper 304', and then the pressure (356) is released, so that the pressure (356) can be applied when the folded portion of the paper 304' is increased in fold.

[0022] Next, in block 440, a determination is made as to whether or not enhanced folding by the secondary roller pair 348, 352 is desired. If it is determined that enhanced folding is required (Yes in block 440), the microcontroller 336 rotates the primary roller pair 312, 316 to advance the sheet 304'. For example, if the sheet 304 contains more than a predefined page number threshold (64 pages), the operation of the second motor drives 360, 364 may be enabled to allow only the folding action by the primary rollers 312, 316 to be completed if the number of pages does not exceed the predefined page number threshold. At block 444, the sheet 304' is fed into the nip of the secondary roller pair 348, 352 for enhanced folding. At next block 448, the microcontroller 336 suspends the feeding of the sheet by the primary roller pair 312, 316. At next block 452, pressure control by the microcontroller 336 causes pressure to be applied by the piston 356 to the folded portion of the sheet 304' located between the secondary roller pair 348, 352. This pressure may be suitably provided by the piston 356, a cam or a solenoid, not shown, as described above. The secondary folding operation is completed at block 456, and the microcontroller 336 turns off the heaters 349, 353, if they are on, at block 460. The completed booklet is ejected at block 464. If the fold is not to be enhanced at block 440 (No at block 440), the process proceeds directly to block 464. If, at block 468, it is determined that another booklet is to be created, the process returns to block 404. If another booklet is not to be created, the process ends at block 472. At block 452, the microcontroller 336 applies pressure from the piston 356 for a period of time that depends on the number of pages in the paper 304' and then releases the pressure, so that pressure can be applied when the folds of the paper 304' are folded more deeply.

[0023] It will be appreciated that the embodiment of FIG. 4 provides a configurable folding system that allows for one or two folding operations, with heat boost to one or both. Thus, a wide variety of paper stack sizes and paper characteristics can be accommodated. When making thin booklets, one roller press operation without heat may be sufficient. When making thicker booklets or booklets using thicker paper, they are best made with two heated roller press operations. Other combinations of stack thickness or paper characteristics are engaged with folding options accordingly. Thus, speed and energy consumption are appropriately balanced with booklet quality.

[0024] FIG. 5 is a diagram showing another embodiment of a paper folder 500. As shown in FIG. The folding device 500 shown in FIG. 5 includes a pair of primary rollers 504, 508 rotating in opposite directions for receiving a sheet 512 into a nip and forming a crease 516. The primary rollers 504, 508 each include a built-in heating element (hereinafter referred to as heater) 520, 524. The crease 516 is urged by the primary rollers 504, 508 into a nip 526 formed between a pair of counter-rotating secondary rollers 528, 532 and is discharged from the primary rollers 504 and 508 at a nip exit 527. One of the secondary rollers, roller 528, is fixedly mounted on its axis for rotational movement and includes an integrated heater 536 therein. The other of the secondary rollers, roller 532, is movable (up and down in FIG. 5) relative to the fixed roller 528 and can apply pressure to the roller 528 according to an up and down biasing mechanism 540. The vertical biasing mechanism 540 is composed of a spring 544 oriented radially inwardly on the shaft of the roller 532 and a driving cam 552 .

[0025] The pressure between the secondary roller pair 528, 532 is a function of the spring constant and compression distance of the spring 544 and is set to a first pressure level when the cam 552 is rotated to a first position and a second pressure level when the cam 552 is rotated to a second position. As an example, a first position of the cam 552 is shown in FIG. 6 and a second position is shown in FIG. 7. Referring to FIG. 6, the folding apparatus 500 is set to have less pressure between the secondary roller pair 528, 532 when the crease 516' enters the nip 526 and engages the nip 526, as illustrated by the position of the cam 552' in FIG. 6. The pressure between the secondary roller pair 528, 532 is set to be stronger when increasing the folding force of the entered crease 516", as illustrated by the position of the cam 552" in FIG. 7. It can be seen that the pressure is appropriately reduced by rotating the cam 552 back to the position of FIG. 6 once the crease 516 has passed the secondary roller pair 528, 532. It should be noted that in the examples of FIGS. 6 and 7, all the rollers are aligned with parallel axes.

[0026] FIG. 8 illustrates an exemplary embodiment of a secondary roller mechanism 800 using a counter-rotating roller pair 802, 804. In this example, roller 802 is constructed of a thermally conductive material such as ceramic or metal. As a specific example, roller 802 is constructed of aluminum with a wall thickness of about 1 mm. Roller 802 is provided with an integrated heater 806 and a thermistor 810 that cooperate to set the surface temperature of roller 802 to a desired temperature. Roller 802 is suitably supported by one or more high temperature bearings, such as bearing 814. Roller 804 is shown as an idler roller suitably constructed of a compressible surface, such as silicone rubber. Roller 804 is supported on either side by floating bearings 808 and 812 that are biased by springs 816 and 820, respectively. The compression of springs 816 and 820 is controlled by the rotational positions of a first eccentric bearing 824 associated with spring 820, which is fixed on the left and right ends of shaft 828, and a second eccentric bearing (not shown) associated with spring 816.

[0027] Figure 9 shows an embodiment of a roller heater 900, such as heater 806 of Figure 8. In this embodiment, roller heater 900 is constructed from infrared halogen heater lamps, suitably 1,000 watt (1,000 joules / second) lamps, which provide sufficient heating and cooling characteristics for controlled roller heating.

[0028] As described above, according to the paper folding device and paper folding method of the embodiment, by effectively heating the primary roller pair and the secondary roller pair, more pages can be folded. Also, by increasing the heating of one or both of the primary roller pair and the secondary roller pair, a wide variety of paper stack sizes and paper characteristics can be accommodated. When creating a thin booklet, the roller pressure operation of the primary roller pair can be performed without heating. When creating a thick booklet or a booklet using thicker paper, the booklet can be best created by applying the roller pressure operation while heating the primary roller pair and the secondary roller pair.

[0029] According to the paper folding device 300 of the embodiment, the paper folding device 300 includes a primary roller pair having a pair of heating rollers 312, 316 with parallel rotation axes, and a nip 320 is formed between the pair of heating rollers 312, 316, a first motor drive unit 328, 332 that rotates the primary roller pair 312, 316 so that the fed paper 304 passes through the nip 320 of the primary roller pair 312, 316 and a folded portion is formed along the crease, and a pair of heating rollers 348, 352 with parallel rotation axes, the rotation axes of the pair of heating rollers 348, 352 being perpendicular to the rotation axes of the primary roller pair 312, 316, and a nip exit 322 The configuration includes a secondary roller pair 348, 352 positioned so that the folded portion of the paper 304' that has exited contacts the nip formed by the pair of heating rollers 348, 352, a second motor drive unit 360, 364 that rotates the secondary roller pair 348, 352 along the folded portion, and a control unit 336 that controls the operation of the first motor drive units 328, 332 and the second motor drive units 360, 364.Since the primary roller pair 312, 316 and the secondary roller pair 348, 352 are composed of a pair of heating rollers, more pages can be folded by thermally heating the paper 304, 304'.

[0030] Furthermore, according to the paper folding device 300, the control unit 336 further stops the first motor drive units 328, 332 when the paper 304' has moved a predetermined distance relative to the secondary roller pair 348, 352, and activates the second motor drive units 360, 364 when the paper is positioned at the predetermined distance, thereby eliminating unnecessary rotation of the primary rollers 312, 316 and reducing failures of the first motor drive units 328, 332, etc.

[0031] Furthermore, according to the paper folding device 300, the control unit 336 further initializes the pressing force (356) applied to the folding portion by the secondary roller pair 348, 352 when the paper 304' is positioned at a predetermined distance, and applies the set pressing force 356 for a period corresponding to the number of pages of the paper 304' and then releases the pressing force (356), so that the pressing force (356) can be applied when the folding of the folding portion of the paper 304' is increased.

[0032] In addition, according to the paper folding device 300, the control unit 336 further enables operation of the second motor drive units 360, 364 when the paper 304 contains pages that exceed a predefined page number threshold, so that if the number of pages does not exceed the predefined page number threshold, the folding operation can be completed with just the primary rollers 312, 316.

[0033] In addition, according to the paper folding device 300, the control unit 336 further heats the heating elements 340, 344 provided inside the primary roller pair 312, 316 toward the nip 320 before the paper 304 is fed in, and stops heating when the folding portion passes through the nip exit 322 of the primary roller pair 312, 316, thereby saving energy for heating the rollers and avoiding the possibility of damage or discoloration of the outer sheet forming the cover of the booklet.

[0034] According to the paper folding method of the embodiment, the steps include the steps of: receiving a fold of a paper sheet 304 being conveyed into a nip 320 formed by a primary roller pair 312, 316 of heated rollers having parallel rotation axes; rotating the primary roller pair 312, 316 so that the paper sheet 304 passes through the nip 320 of the primary roller pair 312, 316 and is folded along the fold to form a folded portion; and rotating the primary roller pair 312, 316 so that the paper sheet 304 passes through the nip 320 of the primary roller pair 312, 316 and is folded along the fold to form a folded portion. Since the method includes steps of receiving the sheet 304' so that its axis of rotation is perpendicular to the axis of rotation of the primary roller pair 312, 316 and the folded portion of the sheet 304' exiting the nip is positioned to abut against the nip of the secondary roller pair 348, 352, and rotating the secondary roller pair 348, 352 along the folded portion, the primary rollers 312, 316 and the secondary rollers 348, 352 can be used as a pair of heating rollers to thermally heat the sheets 304, 304' to fold more pages.

[0035] In the above embodiment, the saddle-stitched bookbinding has been described, but the present invention can be applied to bookbinding other than saddle-stitching. As an example of the increased pressure for folding, a piston or an up-down biasing mechanism is used to indirectly apply pressure to one roller toward the other roller, but a mechanism for biasing one roller shaft may be used, or both rollers may be pressed against each other.

[0036] Although specific embodiments have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the present invention. Indeed, the novel embodiments described herein may be embodied in various other forms, and various omissions, substitutions, and modifications in the forms of the embodiments described herein may be made without departing from the spirit of the present invention. The appended claims and their equivalents are intended to cover such forms or modifications that fall within the spirit and scope of the present invention. [Explanation of symbols]

[0037] 104...Multi-function peripheral (MFP), 108...Finisher, 112...Finishing unit 200…Document Rendering System 300... booklet folding system (paper folding device), 304, 304'... paper 308…crease, 308′…folded edge 312, 316, 504, 508...Primary roller pair (heating roller) 320, 526...nip; 322, 527...nip exit; 324...bending blade 328, 332...first motor drive unit, 360, 364...second motor drive unit 336...Microcontroller (control unit) 348, 352, 528, 532...Secondary roller pair (heated roller) 340, 344, 349, 353, 520, 524, 536, 806... Heating elements (heaters) 346: position sensor; 356: piston; 540: vertical biasing mechanism 544,816,820...Spring, 552...Cam 800...secondary roller mechanism, 802, 804...secondary roller pair (counter-rotating rollers) 808, 814...Floating bearing, 810...Thermistor, 814...Bearing 900...Roller heater

Claims

1. a primary roller pair having a pair of heating rollers with parallel rotation axes, the pair of heating rollers forming a nip therebetween; a first motor drive unit that rotates the primary roller pair so that a folded portion is formed along a crease of a sheet of paper that has been conveyed through a nip between the primary roller pair; a secondary roller pair, which is composed of a pair of heating rollers having parallel rotation axes, the rotation axes of the pair of heating rollers being perpendicular to the rotation axis of the primary roller pair, and which is positioned so that the folded portion of the paper leaving the nip abuts against the nip formed by the pair of heating rollers; a second motor drive unit that rotates the secondary roller pair along the folding portion; a control unit that controls the operation of the first motor drive unit and the second motor drive unit; Equipped with A piston means attached to one of the secondary roller pair separates the secondary roller pair or brings the secondary roller pair into contact with the folded portion at a low pressure until the folded portion is positioned at the nip, and when the folded portion is positioned at the nip, pressure is applied to the folded portion of the secondary roller pair. In this state, the secondary roller pair is caused to travel along the fold by a second motor drive unit. A paper folding device characterized by:

2. The control unit further When the paper has moved a predetermined distance relative to the pair of secondary rollers, the first motor drive unit that rotates the pair of primary rollers is stopped; activating the second motor drive to rotate the secondary roller pair when the paper is positioned at the predetermined distance.

2. The paper folding device according to claim 1.

3. The control unit further includes: When the paper is positioned at the predetermined distance, a pressing force of the piston means applied to the folding portion by the secondary roller pair is initialized, and the pressing force is released after applying the set pressing force for a period corresponding to the number of pages of the paper.

3. The paper folding device according to claim 2.

4. The control unit further 2. The paper folder of claim 1, further comprising: enabling operation of the second motor drive if the paper contains pages that exceed a predefined page number threshold.

5. The control unit further 2. The paper folding device according to claim 1, wherein a heating element provided inside the primary roller pair is heated toward the nip before the paper is fed, and the heating is stopped when the folded portion passes through an exit of the nip of the primary roller pair.

6. receiving a crease of an incoming sheet of paper in a nip formed by a primary roller pair of heated rollers having parallel rotation axes; rotating the primary roller pair such that the sheet passes through the nip of the primary roller pair and is folded along the crease to form a fold; a secondary roller pair consisting of a pair of heated rollers having parallel rotation axes, the rotation axes of the secondary roller pair being perpendicular to the rotation axis of the primary roller pair, and receiving the paper so that the folded portion of the paper exiting the nip is positioned to abut against the nip formed by the secondary roller pair; a piston means attached to one of the secondary rollers for separating or contacting the secondary rollers with low pressure until the fold is located at the nip and applying pressure to the secondary rollers when the fold is located at the nip; running the secondary roller pair along the folded portion while the pressure is applied; A paper folding method comprising the steps of:

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