Sheet conveying apparatus, image forming apparatus, and operation control method

Abstract

The invention provides a sheet conveying apparatus, an image forming apparatus, and an operation control method, which can restrain generation of adverse conditions related to a pair of conveying members used in position correction of a sheet. The sheet conveying apparatus includes a pair of conveying members, a sensor, a movement control unit, a detection processing unit, and a switching processing unit. The pair of conveying members is provided so as to be movable in the width direction of the sheet. The sensor detects a position in a width direction of the sheet conveyed by the pair of conveying members. The movement control unit controls the movement of the pair of conveyance members sandwiching the sheet in the width direction on the basis of a shift amount between a detection position detected by the sensor and a reference position based on a sheet size corresponding to a sheet feed source of the sheet. The detection processing unit detects a sheet size of a sheet. The switching processing section switches whether or not the pair of conveyance members are allowed to move in accordance with a sheet size corresponding to a sheet feed source and the sheet size of the sheet detected by the detection processing section.

Description

Technical Field

[0001] The present invention relates to a sheet conveying device, an image forming device and an action control method. Background Art

[0002] In an image forming apparatus such as a printer, the position of a sheet in the width direction may be offset during the conveyance of the sheet. In view of this, an image forming apparatus is known that uses a pair of conveying members that are arranged to be movable in the width direction to correct the position of the sheet in the width direction. For example, in such an image forming apparatus, the position of the sheet in the width direction is corrected based on the amount of offset between the position of the sheet in the width direction detected by a sensor during conveyance and a reference position based on the sheet size corresponding to the paper supply source of the sheet.

[0003] However, in the image forming apparatus, the sheet size corresponding to the sheet supply source and the sheet size of the sheet stored in the sheet supply source may not match each other. In this case, if the position correction in the width direction of the sheet is performed, the pair of conveying members may move beyond the movable area, thereby causing the pair of conveying members to become immovable. Summary of the invention

[0004] An object of the present invention is to provide a sheet conveying device, an image forming apparatus, and an operation control method, which can suppress the occurrence of disadvantages associated with a pair of conveying members used for position correction of a sheet.

[0005] A sheet conveying device according to one embodiment of the present invention comprises: a pair of conveying members, which are arranged to be movable in a width direction perpendicular to the conveying direction of the sheet to clamp and convey the sheet; a sensor, which detects the position of the sheet conveyed by the pair of conveying members in the width direction; a movement control unit, which controls the movement of the pair of conveying members clamping the sheet in the width direction according to an offset between a detection position detected by the sensor and a reference position, wherein the reference position is a position based on a sheet size corresponding to a paper supply source of the sheet; a detection processing unit, which detects a sheet size of the sheet; and a switching processing unit, which switches whether to allow the pair of conveying members to move according to the sheet size corresponding to the paper supply source of the sheet and the sheet size of the sheet detected by the detection processing unit.

[0006] An image forming apparatus according to another aspect of the present invention includes the sheet conveying device and an image forming unit that forms an image on the sheet conveyed by the sheet conveying device.

[0007] Another embodiment of the present invention is an action control method performed by a sheet conveying device, wherein the sheet conveying device includes: a pair of conveying members, which are configured to be movable in a width direction perpendicular to the conveying direction of the sheet to clamp and convey the sheet; a sensor, which detects the position of the sheet conveyed by the pair of conveying members in the width direction; a movement control unit, which controls the movement of the pair of conveying members clamping the sheet in the width direction according to an offset between a detection position detected by the sensor and a reference position, wherein the reference position is a position based on a sheet size corresponding to a paper supply source of the sheet, and the action control method includes: a detection step, which detects the sheet size of the sheet; and a switching step, which switches whether to allow the pair of conveying members to move according to the sheet size corresponding to the paper supply source of the sheet and the sheet size of the sheet detected by the detection step.

[0008] According to the present invention, it is possible to suppress the occurrence of disadvantages associated with a pair of conveying members used for position correction of a sheet.

[0009] This specification is presented in a simplified form, with appropriate reference to the accompanying drawings, to summarize the concepts described in the following detailed description. This specification is not intended to limit the important features and essential features of the subject matter described in the claims, nor is it intended to limit the scope of the subject matter described in the claims. In addition, the subject matter described in the claims is not limited to implementations that solve some or all of the disadvantages described in any part of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a cross-sectional view showing the structure of an image forming apparatus according to an embodiment of the present invention.

[0011] Figure 2 This is a block diagram showing the system configuration of the image forming apparatus according to the embodiment of the present invention.

[0012] Figure 3 It is a perspective view showing the structure of a paper feed cassette of the image forming apparatus according to the embodiment of the present invention.

[0013] Figure 4 It is a right side view showing the configuration of a position correction unit of the image forming apparatus according to the embodiment of the present invention.

[0014] Figure 5 This is a flowchart showing an example of an operation control process executed by the image forming apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the following embodiment is an example of embodying the present invention and does not limit the technical scope of the present invention.

[0016] (Configuration of Image Forming Apparatus 100) First, refer to Figure 1 and Figure 2 The configuration of the image forming apparatus 100 according to the embodiment of the present invention will be described.

[0017] In addition, for convenience of explanation, the image forming apparatus 100 can use the setting state ( Figure 1 In the state shown in FIG. 1 , the vertical direction is defined as the up-down direction D1. Figure 1 The front side of the image forming apparatus 100 shown in the drawing is defined as the front side (front), and the front-back direction D2 is defined. In addition, the left-right direction D3 is defined based on the front side of the image forming apparatus 100 in the above-described setting state.

[0018] The image forming apparatus 100 is an image processing apparatus having a printing function, and is used to print a sheet SH (see Figure 4 ) forms an image based on the image data. Specifically, the image forming device 100 is a digital multifunction machine having multiple functions including the printing function. In addition, the image forming device of the present invention may also be a printer, a fax machine or a copier having the printing function.

[0019] like Figure 1 and Figure 2 As shown, the image forming apparatus 100 includes an automatic document feeder 1 , an image reading unit 2 , an image forming unit 3 , a sheet conveying unit 4 , an operation display unit 5 , a storage unit 6 , and a control unit 7 .

[0020] The automatic document feeder 1 feeds a document whose image is read by the image reading section 2. The automatic document feeder 1 includes a document setting section, a plurality of conveying rollers, a document pressing member, and a paper discharge section.

[0021] The image reading unit 2 realizes a scanning function of reading an image of a document. The image reading unit 2 includes a document table, a light source, a plurality of reflection mirrors, an optical lens, and a CCD (Charge Coupled Device).

[0022] The image forming unit 3 realizes the printing function. Specifically, the image forming unit 3 forms a color or black-and-white image on the sheet SH conveyed by the sheet conveying unit 4 according to the electrophotographic method. In addition, the image forming unit 3 may also form an image on the sheet SH conveyed by the sheet conveying unit 4 by the inkjet method.

[0023] like Figure 1As shown, the image forming unit 3 includes a plurality of image forming units 11 to 14, an optical scanning device 15, an intermediate transfer belt 16, a secondary transfer roller 17, a fixing device 18, and a paper output tray 19. The image forming unit 11 forms a toner image on the intermediate transfer belt 16 using a toner of Y (yellow). The image forming unit 12 forms a toner image on the intermediate transfer belt 16 using a toner of C (cyan). The image forming unit 13 forms a toner image on the intermediate transfer belt 16 using a toner of M (magenta). The image forming unit 14 forms a toner image on the intermediate transfer belt 16 using a toner of K (black). The plurality of image forming units 11 to 14 are respectively provided with a photosensitive drum, a charging roller, a developing device, a primary transfer roller, and a drum cleaning unit. The optical scanning device 15 emits light based on image data toward the surface of the photosensitive drum of each image forming unit 11 to 14. The toner images formed on the surfaces of the photosensitive drums of the image forming units 11 to 14 are transferred to the intermediate transfer belt 16. The secondary transfer roller 17 transfers the toner images transferred to the surface of the intermediate transfer belt 16 to the sheet SH conveyed by the sheet conveying unit 4. The fixing device 18 fixes the toner images transferred to the sheet SH by the secondary transfer roller 17 on the sheet SH. The sheet SH to which the toner images are fixed by the fixing device 18 is discharged to the paper discharge tray 19.

[0024] The sheet conveying unit 4 is arranged along the conveying direction D4 (see Figure 1 ) The sheet SH on which an image is formed by the image forming unit 3 is conveyed. The conveying direction D4 is a direction along a plane perpendicular to the front-rear direction D2.

[0025] The operation display unit 5 is a user interface of the image forming apparatus 100. The operation display unit 5 includes a display unit and an operation unit. The display unit displays various information according to control instructions from the control unit 7. For example, the display unit is a liquid crystal display. The operation unit inputs various information to the control unit 7 according to user operations. For example, the operation unit is a touch panel.

[0026] The storage unit 6 is a nonvolatile storage device. For example, the storage unit 6 is a flash memory. Alternatively, the storage unit 6 may be an SSD (Solid State Drive) or an HDD (Hard Disk Drive).

[0027] The control unit 7 performs overall control of the image forming apparatus 100. The control unit 7 may be a control unit provided separately from a main control unit that performs overall control of the image forming apparatus 100.

[0028] like Figure 2As shown, the control unit 7 includes a CPU 21, a ROM 22, and a RAM 23. The CPU 21 is a processor that performs various calculation processes. The ROM 22 is a non-volatile storage device that pre-stores information such as control programs for the CPU 21 to perform various processes. The RAM 23 is a volatile or non-volatile storage device used as a temporary memory (operating area) for various processes performed by the CPU 21. The CPU 21 performs overall control of the image forming apparatus 100 by executing various control programs pre-stored in the ROM 22. In addition, the control unit 7 can be composed of an electronic circuit such as an integrated circuit (ASIC).

[0029] (Configuration of Sheet Conveying Unit 4) Next, refer to Figure 1 to Figure 3 The configuration of the sheet conveying unit 4 will be described.

[0030] like Figure 1 As shown, the sheet conveying section 4 includes a sheet feeding cassette 31 , a pickup roller 32 , a sheet feeding roller 33 , a separation roller 34 , and a sheet conveying path 35 .

[0031] The paper feeding cassette 31 stores sheets SH on which images are formed by the image forming unit 3. For example, the paper feeding cassette 31 stores sheets SH such as paper, coated paper, postcards, envelopes, and OHP sheets.

[0032] Here, in the image forming apparatus 100 , the sheet size corresponding to the paper feed cassette 31 is set according to the user operation on the operation display unit 5 .

[0033] For example, the control unit 7 causes the operation display unit 5 to display a sheet size setting screen used for setting the sheet size corresponding to the paper feed cassette 31 according to a predetermined user operation on the operation display unit 5. Then, the control unit 7 sets the sheet size corresponding to the paper feed cassette 31 according to the user operation on the sheet size setting screen.

[0034] like Figure 3 As shown, the paper feed cassette 31 includes a storage portion 41, a lifting member 42, a rear end stopper 43, a pair of side stops 44, and a gripping portion 45. Figure 2 A first sensor 46 and a second sensor 47 are shown.

[0035] The storage section 41 defines a storage space for the sheet SH. Figure 3 As shown, the housing portion 41 is formed in a box shape with an upper side open.

[0036] The lifting member 42 is provided at the bottom of the storage section 41 so as to be movable upward and downward in the vertical direction D1. The lifting member 42 lifts the bundle of sheets SH stored in the paper feed cassette 31 to a contact position where the bundle of sheets SH contacts the pickup roller 32.

[0037] The rear end stopper 43 is provided at the bottom of the storage section 41 so as to be movable in the left-right direction D3. The rear end stopper 43 is in contact with the sheet SH stored in the storage section 41 in the conveying direction D4 (see FIG. 2 ). Figure 1 and Figure 3 ) to align the position of the sheet SH in the storage portion 41.

[0038] The pair of side stoppers 44 are provided at the bottom of the storage section 41 so as to be movable in the front-rear direction D2. The pair of side stoppers 44 are provided at the bottom of the storage section 41 so as to be movable in the front-rear direction D2. Figure 3 ) are brought into contact with each other to align the position of the sheet SH in the storage section 41. The width direction D5 is a direction perpendicular to the conveying direction D4. The position of the sheet SH in the storage section 41 is aligned by a pair of side guards 44 so that the sheet SH stored in the paper feed cassette 31 is conveyed along the center of the width direction D5 in the sheet conveying path 35.

[0039] The grip portion 45 is provided at the front end portion of the paper feed cassette 31. The grip portion 45 is used to insert and remove the paper feed cassette 31 from the housing of the image forming apparatus 100.

[0040] The first sensor 46 detects the conveying direction D4 (see FIG. 2 ) of the sheet SH stored in the storage section 41 . Figure 3 For example, the first sensor 46 includes a first variable resistor whose resistance changes according to the position of the rear end stopper 43 in the receiving portion 41, and is a circuit capable of outputting a first electrical signal corresponding to the resistance of the first variable resistor.

[0041] The second sensor 47 detects the width direction D5 (see FIG. 5 ) of the sheet SH stored in the storage section 41 . Figure 3 For example, the second sensor 47 includes a second variable resistor whose resistance changes according to the interval between the pair of side stoppers 44, and is a circuit capable of outputting a second electrical signal corresponding to the resistance of the second variable resistor.

[0042] The pickup roller 32 is provided on the upper side of the paper feed cassette 31. The pickup roller 32 contacts the topmost sheet SH in the stack of sheets SH lifted to the contact position by the lifting member 42, and moves the sheet SH in the conveying direction D4 (see FIG. Figure 1 and Figure 3 )delivery.

[0043] The paper feed roller 33 contacts the upper surface of the sheet SH conveyed by the pickup roller 32 , thereby conveying the sheet SH along the sheet conveyance path 35 .

[0044] The separation roller 34 is provided on the lower side of the paper feed roller 33. A biasing member (not shown) biases the separation roller 34 toward the paper feed roller 33. Thus, a paper feed slit portion for clamping the sheet SH is formed between the paper feed roller 33 and the separation roller 34. When a plurality of sheets SH are conveyed to the paper feed slit portion, the separation roller 34 separates the other sheets SH from the sheet SH in contact with the paper feed roller 33.

[0045] The sheet conveying path 35 is a path for the sheet SH to move from the paper feed cassette 31 to the paper output tray 19 via the secondary transfer roller 17 and the fixing device 18. The sheet conveying path 35 is provided with a paper feed roller 33 and a separation roller 34. In addition, a plurality of conveying roller pairs are provided in the sheet conveying path 35 at intervals from each other. In the sheet conveying path 35, the sheet SH is conveyed in the conveying direction D4 (see FIG. 1 ) by the paper feed roller 33 and the plurality of conveying roller pairs. Figure 1 )delivery.

[0046] Here, in the image forming apparatus 100, during the conveyance of the sheet SH, a change in the width direction D5 (see FIG. 2 ) of the sheet SH occurs. Figure 3 ) in the image forming apparatus 100. Figure 1 , Figure 2 and Figure 4 The position correction unit 8 is shown.

[0047] (Configuration of Position Correction Unit 8) Next, refer to Figure 1 , Figure 2 and Figure 4 The configuration of the position correction unit 8 will be described.

[0048] The position correction unit 8 corrects the position of the sheet SH being conveyed in the width direction D5 .

[0049] like Figure 1 As shown, the position correction unit 8 is provided in the sheet conveyance path 35 on the upstream side of the secondary transfer roller 17 in the conveyance direction D4 and on the downstream side of the paper feed roller 33 in the conveyance direction D4 .

[0050] like Figure 1 , Figure 2 and Figure 4 As shown, the position correction unit 8 includes a correction roller pair 51 , a support portion 52 , a moving mechanism 53 , a third sensor 54 , and a movement control portion 55 .

[0051] The correction roller pair 51 is provided so as to be able to move in a direction D4 (see FIG. Figure 4 )Vertical width direction D5 (refer to Figure 4) moves to clamp and convey the sheet SH. The correction roller pair 51 is an example of a pair of conveying members of the present invention.

[0052] Specifically, the correction roller pair 51 includes a driving roller that receives a driving force supplied from a motor (not shown) to rotate, and a driven roller that is disposed opposite to the driving roller. A force-applying member (not shown) applies force to the driven roller toward the driving roller. Thus, a conveying slit for clamping the sheet SH is formed between the driving roller and the driven roller. The correction roller pair 51 conveys the sheet SH in the conveying direction D4.

[0053] The support portion 52 rotatably supports the correction roller pair 51 .

[0054] like Figure 4 As shown, the support portion 52 includes a first bearing portion 52A, a second bearing portion 52B, and an extension portion 52C. The first bearing portion 52A rotatably supports the rotation axis of the front side of the driving roller and the rotation axis of the front side of the driven roller. The second bearing portion 52B rotatably supports the rotation axis of the rear side of the driving roller and the rotation axis of the rear side of the driven roller. The extension portion 52C is formed in a strip shape in the width direction D5, and supports the first bearing portion 52A and the second bearing portion 52B.

[0055] The support portion 52 is supported by the housing of the image forming apparatus 100 so as to be able to extend in the width direction D5 (see Figure 4 ) moves. In addition, the correction roller pair 51 is provided so as to be movable integrally with the support portion 52. Thus, if the support portion 52 moves in the width direction D5, the correction roller pair 51 supported by the support portion 52 also moves in the width direction D5.

[0056] For example, the correction roller pair 51 is provided so that the front end 51A (see Figure 4 ) from the starting position P1 (ref. Figure 4 ) moves to both sides of the width direction D5 by a distance L1 (refer to Figure 4 ).

[0057] The moving mechanism 53 moves the correction roller pair 51 in the width direction D5. Specifically, the moving mechanism 53 includes: a motor that generates a driving force to move the correction roller pair 51 and the support portion 52; and a power transmission mechanism that transmits the driving force generated by the motor to the support portion 52. The support portion 52 moves in the width direction D5 using the driving force transmitted from the moving mechanism 53.

[0058] The third sensor 54 detects the position in the width direction D5 of the sheet SH conveyed by the correction roller pair 51. The third sensor 54 is an example of the sensor of the present invention.

[0059] like Figure 4As shown, the third sensor 54 is disposed in the sheet conveying path 35 on the downstream side of the correction roller pair 51 in the conveying direction D4. Alternatively, the third sensor 54 may be disposed in the sheet conveying path 35 on the upstream side of the correction roller pair 51 in the conveying direction D4.

[0060] For example, the third sensor 54 is a contact image sensor (CIS) formed in a strip shape in the width direction D5. The third sensor 54 is arranged to be opposite to one end of the sheet SH conveyed along the sheet conveying path 35 in the width direction D5 (the end on the rear side of the front-to-back direction D2). Specifically, the third sensor 54 is arranged opposite to an area on the side of the width direction D5 (the area on the rear side of the front-to-back direction D2) in the sheet conveying path 35 that is closer to the central part of the width direction D5. When the sheet SH passes through the relative position of the third sensor 54 in the sheet conveying path 35, the third sensor 54 captures one end of the sheet SH in the width direction D5 (the end on the rear side of the front-to-back direction D2) and outputs captured data indicating the position of the end. The captured data output from the third sensor 54 is input to the movement control unit 55. In addition, the third sensor 54 may also be a transmissive or reflective optical sensor arranged along the width direction D5.

[0061] The movement control unit 55 controls the movement of the correction roller pair 51 clamping the sheet SH in the width direction D5 according to the deviation between the detection position detected by the third sensor 54 and the reference position based on the sheet size corresponding to the paper supply source (paper supply cassette 31) of the sheet SH.

[0062] For example, the movement control unit 55 is constituted by a circuit such as an integrated circuit (ASIC).

[0063] Here, the reference position is the position of one end (end on the rear side in the front-rear direction D2) of the sheet SH in the width direction D5 when the sheet SH of the sheet size corresponding to the sheet feed cassette 31 passes through the relative position of the third sensor 54 in the sheet conveying path 35 without deviation in the width direction D5. In the image forming apparatus 100, the reference position corresponding to the sheet size is predetermined according to the sheet size of the sheet SH that can be accommodated in the sheet feed cassette 31. For example, the movement control unit 55 recognizes the reference position by using a notification from the control unit 7.

[0064] For example, when the position of one end in the width direction D5 of the sheet SH (the end on the rear side in the front-to-rear direction D2) determined based on the photographic data output from the third sensor 54 is closer to the rear side in the front-to-rear direction D2 than the reference position, the offset amount is a positive value. In addition, when the position of one end in the width direction D5 of the sheet SH (the end on the rear side in the front-to-rear direction D2) determined based on the photographic data output from the third sensor 54 is closer to the front side in the front-to-rear direction D2 than the reference position, the offset amount is a negative value.

[0065] When the offset is a positive value, the movement control unit 55 controls the movement mechanism 53 to move the correction roller pair 51 holding the sheet SH to the front side in the front-rear direction D2 by the same amount as the offset. In addition, when the offset is a negative value, the movement control unit 55 controls the movement mechanism 53 to move the correction roller pair 51 holding the sheet SH to the rear side in the front-rear direction D2 by the same amount as the offset. That is, the movement control unit 55 moves the correction roller pair 51 holding the sheet SH so that one end of the sheet SH in the width direction D5 (the rear end in the front-rear direction D2) is arranged at the reference position.

[0066] However, in the image forming apparatus 100, the sheet size corresponding to the paper supply source (paper supply cassette 31) of the sheet SH and the sheet size of the sheet SH accommodated in the paper supply source may not match. Here, in the conventional image forming apparatus, when the sheet size corresponding to the paper supply source of the sheet SH and the sheet size of the sheet SH accommodated in the paper supply source do not match, if the position correction in the width direction D5 of the sheet SH is performed, an unfavorable situation may occur, such as the correction roller pair 51 moves beyond the movable area, thereby causing the correction roller pair 51 to be immovable.

[0067] In contrast, the image forming apparatus 100 according to the embodiment of the present invention can suppress the occurrence of troubles related to the correction roller pair 51 as described below.

[0068] (Configuration of Control Unit 7) Next, refer to Figure 2 The configuration of the control unit 7 will be described in more detail.

[0069] like Figure 2 As shown, the control unit 7 includes a detection processing unit 61, a switching processing unit 62, and a notification processing unit 63. The device including the sheet conveying unit 4, the control unit 7, and the position correction unit 8 is an example of the sheet conveying device of the present invention. In addition, the present invention can be applied to the automatic document feeding device 1.

[0070] Specifically, an action control program for causing the CPU 21 of the control unit 7 to function as the above-mentioned processing units is pre-stored in the ROM 22 of the control unit 7. Moreover, the CPU 21 of the control unit 7 functions as the above-mentioned processing units by executing the action control program stored in the ROM 22. In addition, a part or all of the processing units included in the control unit 7 may be composed of circuits. In addition, the action control program may also be a program for causing multiple processors to function as the processing units included in the control unit 7. In addition, the control unit 7 may include a movement control unit 55.

[0071] The detection processing unit 61 detects the sheet size of the sheet SH.

[0072] For example, the detection processing unit 61 detects the sheet size of the sheet SH accommodated in the paper feed cassette 31 using the first sensor 46 and the second sensor 47. Specifically, the detection processing unit 61 determines the sheet size of the sheet SH accommodated in the paper feed cassette 31 based on the size of the sheet SH in the conveying direction D4 detected by the first sensor 46 and the size of the sheet SH in the width direction D5 detected by the second sensor 47.

[0073] In addition, the detection processing unit 61 may detect the sheet size of the sheet SH accommodated in the paper feeding cassette 31 using a sheet sensor (not shown) that detects the sheet SH on the upstream side of the position correction unit 8 in the conveying direction D4 in the sheet conveying path 35. Specifically, the detection processing unit 61 may calculate the size of the sheet SH in the conveying direction D4 based on the detection time of the sheet SH by the sheet sensor and the conveying speed of the sheet SH by the sheet conveying unit 4, and determine the sheet size of the sheet SH based on the calculation result.

[0074] The switching processing unit 62 switches whether or not to allow the correction roller pair 51 to move, based on the sheet size corresponding to the paper feed source of the sheet SH and the sheet size of the sheet SH detected by the detection processing unit 61 .

[0075] For example, when the sheet size corresponding to the paper supply source of the sheet SH is included in the sheet size group corresponding to the sheet size of the sheet SH detected by the detection processing unit 61, the switching processing unit 62 allows the correction roller pair 51 to move, and when it is not included in the sheet size group, the correction roller pair 51 is not allowed to move.

[0076] Here, the sheet size group corresponding to the sheet size detected by the detection processing unit 61 includes the sheet size. In addition, the size difference in the width direction D5 between the sheet size group corresponding to the sheet size detected by the detection processing unit 61 and the sheet size includes the correctable amount ( Figure 4 In the image forming apparatus 100 , the sheet size group corresponding to the sheet size SH accommodable in the paper feeding cassette 31 is predetermined.

[0077] For example, when the sheet size corresponding to the paper feed cassette 31 is included in the sheet size group corresponding to the sheet size detected by the detection processing unit 61, the switching processing unit 62 transmits a first control signal to the movement control unit 55 to allow the correction roller pair 51 to move, and notifies the movement control unit 55 of the reference position. Furthermore, when the sheet size corresponding to the paper feed cassette 31 is not included in the sheet size group corresponding to the sheet size detected by the detection processing unit 61, the switching processing unit 62 transmits a second control signal to the movement control unit 55 to not allow the correction roller pair 51 to move. In addition, instead of transmitting the second control signal, the switching processing unit 62 may stop the power supply to the moving mechanism 53, the third sensor 54, and the movement control unit 55.

[0078] Alternatively, the switching processing unit 62 may allow the correction roller pair 51 to move when the sheet size corresponding to the paper feed source of the sheet SH matches the sheet size of the sheet SH detected by the detection processing unit 61 , and may not allow the correction roller pair 51 to move when they do not match.

[0079] When the switching processing unit 62 does not permit the correction roller pair 51 to move, the notification processing unit 63 notifies the switch processing unit 62 of the fact.

[0080] For example, since the sheet size corresponding to the paper feed cassette 31 does not match the sheet size of the sheets SH accommodated in the paper feed cassette 31, the notification processing unit 63 causes the operation display unit 5 to display a message indicating that the position correction of the sheets SH is not to be performed. The notification processing unit 63 may also output audio data including the above information.

[0081] (Motion Control Processing) Next, refer to Figure 5 An example of the operation control process steps executed by the control unit 7 in the image forming apparatus 100 is described, and the operation control method of the present invention is described. When an image forming process for forming an image on a sheet SH is executed, the operation control process is executed before the image forming process.

[0082] <Step S11> First, in step S11 , the control unit 7 detects the sheet size of the sheet SH. Here, the process of step S11 is an example of a detection step of the present invention, and is executed by the detection processing unit 61 of the control unit 7 .

[0083] Specifically, the control unit 7 determines the sheet size of the sheets SH stored in the paper feed cassette 31 based on the size of the sheet SH in the conveying direction D4 detected by the first sensor 46 and the size of the sheet SH in the width direction D5 detected by the second sensor 47 .

[0084] <Step S12> In step S12 , the control unit 7 determines whether the sheet size corresponding to the paper feed cassette 31 is included in the sheet size group corresponding to the sheet size detected by the process in step S11 .

[0085] Here, if it is determined that the sheet size corresponding to the paper feed cassette 31 is included in the sheet size group corresponding to the processing result of step S11 (the "Yes" side of S12), the control unit 7 transfers the processing to step S13. In addition, if the sheet size corresponding to the paper feed cassette 31 is not included in the sheet size group corresponding to the processing result of step S11 (the "No" side of S12), the control unit 7 transfers the processing to step S14.

[0086] <Step S13> In step S13 , the control section 7 allows the correction roller pair 51 to move.

[0087] Specifically, the control unit 7 sends the first control signal to the movement control unit 55, and notifies the reference position to the movement control unit 55. In this way, the movement control unit 55 can correct the position of the sheet SH during the execution of the image forming process.

[0088] <Step S14> In step S14, the control unit 7 does not allow the correction roller pair 51 to move. Here, the processing of step S12, step S13, and step S14 is an example of a switching process of the present invention, and is executed by the switching processing unit 62 of the control unit 7.

[0089] Specifically, the control portion 7 transmits the second control signal to the movement control portion 55. Thus, the movement control portion 55 is restricted from correcting the position of the sheet SH during execution of the image forming process.

[0090] <Step S15> In step S15, the control unit 7 notifies that the movement of the correction roller pair 51 is not allowed. Here, the process of step S15 is executed by the notification processing unit 63 of the control unit 7.

[0091] Specifically, the control unit 7 causes the operation display unit 5 to display the information.

[0092] In this way, in the image forming apparatus 100, whether or not to allow the correction roller pair 51 to move is switched according to the sheet size corresponding to the paper feed cassette 31 and the sheet size of the sheet SH detected by the detection processing unit 61. In this way, when the sheet size corresponding to the paper feed cassette 31 and the sheet size of the sheet SH detected by the detection processing unit 61 do not match, the movement of the correction roller pair 51 can be restricted. Therefore, it is possible to suppress the occurrence of an inconvenience such as the correction roller pair 51 being immobilized due to the correction roller pair 51 moving beyond the movable region.

[0093] Furthermore, in the image forming apparatus 100, even when the sheet size corresponding to the paper feed cassette 31 and the sheet size of the sheet SH detected by the detection processing unit 61 do not match, the correction roller pair 51 is allowed to move when the sheet size corresponding to the paper feed cassette 31 is included in the sheet size group corresponding to the detection result of the detection processing unit 61. Thus, until the size difference between the sheet size corresponding to the paper feed cassette 31 and the sheet size of the sheet SH detected by the detection processing unit 61 is small and the possibility that the correction roller pair 51 moves beyond the movable area is low, it is possible to avoid limitation of the position correction of the sheet SH.

[0094] (Additional Notes on Invention) The following supplementary notes summarize the invention extracted from the above-mentioned embodiments. In addition, each configuration and each processing function described in the following supplementary notes can be arbitrarily selected and combined.

[0095] <Note 1> A sheet conveying device comprises: a pair of conveying members, which are arranged to be movable in a width direction perpendicular to a conveying direction of the sheet to clamp and convey the sheet; a sensor, which detects a position in the width direction of the sheet conveyed by the pair of conveying members; a movement control unit, which controls the movement of the pair of conveying members clamping the sheet in the width direction according to an offset between a detection position detected by the sensor and a reference position, wherein the reference position is a position based on a sheet size corresponding to a paper supply source of the sheet; a detection processing unit, which detects a sheet size of the sheet; and a switching processing unit, which switches whether to allow the pair of conveying members to move according to the sheet size corresponding to the paper supply source of the sheet and the sheet size of the sheet detected by the detection processing unit.

[0096] <Note 2> According to the sheet conveying device described in Note 1, when the sheet size corresponding to the paper supply source of the sheet and the sheet size of the sheet detected by the detection processing unit are consistent, the switching processing unit allows the pair of conveying components to move, and when they are inconsistent, the switching processing unit does not allow the pair of conveying components to move.

[0097] <Note 3> According to the sheet conveying device described in Note 1, when the sheet size corresponding to the paper supply source of the sheet is included in the sheet size group corresponding to the sheet size detected by the detection processing unit, the switching processing unit allows the pair of conveying components to move, and when it is not included in the sheet size group, the switching processing unit does not allow the pair of conveying components to move.

[0098] <Note 4> The sheet conveying device according to any one of Supplementary Notes 1 to 3, further comprising a notification processing unit configured to notify, when the switching processing unit does not permit the pair of conveying members to move, of the fact.

[0099] <Note 5> An image forming apparatus comprises: the sheet conveying device according to any one of Supplementary Notes 1 to 4; and an image forming unit that forms an image on the sheet conveyed by the sheet conveying device.

[0100] <Note 6> 14. The method of claim 13 wherein the plurality of conveying members are configured to move along a width direction perpendicular to a conveying direction of the sheet so as to clamp and convey the sheet; a sensor for detecting a position in the width direction of the sheet conveyed by the pair of conveying members; and a movement control unit for controlling movement of the pair of conveying members clamping the sheet in the width direction according to an offset between a detection position detected by the sensor and a reference position, wherein the reference position is a position based on a sheet size corresponding to a paper supply source of the sheet, wherein the movement control method comprises: a detection step for detecting a sheet size of the sheet; and a switching step for switching whether to allow the pair of conveying members to move according to a sheet size corresponding to the paper supply source of the sheet and a sheet size of the sheet detected by the detection step.

[0101] The scope of the present invention is not limited to the above content, but is defined by the description of the claims, so it can be considered that the embodiments described in this specification are only illustrative, not limiting. Therefore, all changes that do not depart from the scope and limits of the claims, as well as contents that are equivalent to the scope and limits of the claims, are included in the scope of the claims.

Claims

1. A sheet conveying device, characterized in that include: A pair of conveying members, arranged to be movable in a width direction perpendicular to a conveying direction of the sheet, to clamp and convey the sheet; a sensor for detecting a position in the width direction of the sheet conveyed by the pair of conveying members; a movement control unit that controls movement of the pair of conveying members that clamp the sheet in the width direction according to an amount of displacement between a detection position detected by the sensor and a reference position that is a position based on a sheet size corresponding to a paper supply source of the sheet; a detection processing unit for detecting a sheet size of the sheet; and The switching processing unit switches whether to allow the pair of conveying members to move, based on a sheet size corresponding to a paper supply source of the sheet and the sheet size of the sheet detected by the detection processing unit.

2. The sheet conveying device according to claim 1, wherein: The switching processing unit allows the pair of conveying members to move when the sheet size corresponding to the paper supply source of the sheet and the sheet size detected by the detection processing unit match, and does not allow the pair of conveying members to move when they do not match.

3. The sheet conveying device according to claim 1, wherein: The switching processing unit allows the pair of conveying members to move when the sheet size corresponding to the paper supply source of the sheet is included in the sheet size group corresponding to the sheet size detected by the detection processing unit, and does not allow the pair of conveying members to move when the sheet size is not included in the sheet size group.

4. The sheet conveying device according to claim 1, wherein: A notification processing unit is provided for notifying, when the switching processing unit does not permit the pair of conveying members to move, of the fact.

5. An image forming device, characterized in that include: The sheet conveying device according to any one of claims 1 to 4; as well as An image forming unit that forms an image on the sheet conveyed by the sheet conveying device.

6. An action control method, performed by a sheet conveying device, the sheet conveying device comprising: A pair of conveying members are arranged to be movable in a width direction perpendicular to a conveying direction of a sheet, clamping and conveying the sheet; a sensor detects a position of the sheet conveyed by the pair of conveying members in the width direction; and a movement control unit controls the movement of the pair of conveying members clamping the sheet in the width direction according to an offset between a detection position detected by the sensor and a reference position, wherein the reference position is a position based on a sheet size corresponding to a paper supply source of the sheet, wherein the action control method is characterized by comprising: a detection step of detecting the sheet size of the sheet; and The switching step switches whether to allow the pair of conveying members to move, based on a sheet size corresponding to a paper supply source of the sheet and the sheet size of the sheet detected by the detecting step.

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