Sheet conveyance device and image forming device

Abstract

To correct the inclination of a conveyed sheet by a simple mechanism.SOLUTION: A first conveyance mechanism 32 conveys a sheet. A correction member 71 is provided on the upstream side of the sheet in a conveying direction with respect to the first conveyance mechanism 32 and has a contact surface 71a that comes into contact with the side end of the sheet at one width end of the sheet on a conveyance path. A first direction adjustment mechanism 72 operates upon an input of a drive signal to change the angle of the contact surface 71a. A second conveyance mechanism 74 is provided on the upstream side of the conveying direction with respect to the correction member 71, and conveys the sheet toward the contact surface 71a in a direction oblique to the conveying direction. A support member 73 supports the correction member 71 and the first direction adjustment mechanism 72. A second direction adjustment mechanism 74 is manually operated to be able to change the direction of the support member 73.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a sheet conveying device and an image forming apparatus having a mechanism for correcting the skew of a sheet. [Background technology]

[0002] 2. Description of the Related Art It is known that an image forming apparatus includes a mechanism for correcting the skew of a sheet being conveyed toward an image forming unit.

[0003] For example, it is known that the skew of the sheet is corrected by conveying the sheet to a nipping portion of a pair of registration rollers that are temporarily stopped (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-30412 Summary of the Invention [Problem to be solved by the invention]

[0005] In the image forming apparatus, it is required that the skew of the sheet be corrected more reliably in order to improve the image quality.

[0006] For example, it is required to detect the skew angle of the sheet being conveyed and more reliably correct the skew of the sheet in accordance with the detection result of the skew angle.

[0007] It is also desirable that the mechanism for correcting the inclination of the sheet be realized by a simple mechanism.

[0008] SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet conveying device and an image forming apparatus that can correct the skew of a sheet being conveyed by a simple mechanism. [Means for solving the problem]

[0009] According to one aspect of the present invention, a sheet conveying device includes a first conveying mechanism, a correcting member, a first orientation adjustment mechanism, a second conveying mechanism, a support member, and a second orientation adjustment mechanism. The first conveying mechanism conveys a sheet. The correcting member is provided upstream of the first conveying mechanism in a conveying direction of the sheet by the first conveying mechanism, and has a contact surface that contacts a side edge of the sheet at one end of a width direction of the sheet conveying path perpendicular to the conveying direction. The first orientation adjustment mechanism is activated by input of a drive signal and changes the angle of the contact surface with respect to the conveying direction. The second conveying mechanism is provided upstream of the correcting member in the conveying direction, and conveys the sheet toward the contact surface in a direction oblique to the conveying direction. The support member supports the correcting member and the first orientation adjustment mechanism. The second orientation adjustment mechanism is manually operable to change the orientation of the support member with respect to the conveying direction.

[0010] According to another aspect of the present invention, an image forming apparatus includes the sheet conveying device, an image forming unit, an image reading device, an image processing unit, and an adjustment processing unit. The image forming unit forms an image on the sheet conveyed by the first conveying mechanism. The image reading device reads the outline of the sheet conveyed by the sheet conveying device. The image processing unit derives an inclination angle of the sheet with respect to the conveying direction based on the read image obtained by the image reading device. The adjustment processing unit outputs the drive signal to the first orientation adjustment mechanism based on the derived inclination angle. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a sheet conveying device and an image forming apparatus that can correct the skew of a sheet being conveyed with a simple mechanism. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram showing the configuration of an image forming apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing the configuration of a control device in the image forming apparatus according to the embodiment of the present invention. [Figure 3] FIG. 3 is a plan view showing the configuration of the conveyor belt and the line sensor in the image forming apparatus according to the embodiment of the present invention. [Figure 4] FIG. 4 is a plan view showing the configuration of the tilt correction mechanism in the image forming apparatus according to the embodiment of the present invention. [Figure 5] FIG. 5 is a diagram showing an adjustment screw and an adjustment scale in the image forming apparatus according to the embodiment of the present invention. [Figure 6] FIG. 6 is a flowchart showing an example of the procedure of the first tilt correction process in the image forming apparatus according to the embodiment of the present invention. [Figure 7] FIG. 7 is a diagram showing an example of image data used in the first inclination derivation process in the image forming apparatus according to the embodiment of the present invention. [Figure 8] FIG. 8 is a flowchart showing an example of the procedure of the second tilt correction process in the image forming apparatus according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the following embodiment is an example of a specific embodiment of the present invention and does not limit the technical scope of the present invention.

[0014] [Configuration of image forming apparatus 10] An image forming apparatus 10 according to an embodiment of the present invention includes a sheet storage unit 1, a sheet conveying device 3, and a printing device 4. The image forming apparatus 10 further includes a drying device 5, an operating device 801, a display device 802, a control device 8, and the like.

[0015] The sheet transport device 3 includes a sheet feeding mechanism 30, a plurality of pairs of transport rollers 31, a first belt transport device 32, a second belt transport device 33, and a discharge roller pair 34. The sheet transport device 3 further includes a skew correction mechanism 7.

[0016] The sheet feeding mechanism 30 feeds the sheet 9 in the sheet storage unit 1 to the first conveying path 301. A plurality of pairs of conveying rollers 31 convey the sheet 9 along the first conveying path 301, and further sends the sheet 9 to the skew correction mechanism 7.

[0017] The skew correction mechanism 7 is disposed upstream of the first belt conveying device 32 on the first conveying path 301. The skew correction mechanism 7 sends out the sheet 9 from the first conveying path 301 to the first belt conveying device 32 while correcting the skew of the sheet 9.

[0018] The first belt conveying device 32 takes over from the skew correcting mechanism 7 to convey the sheet 9, and sends the sheet 9 to the second belt conveying device 33. The first belt conveying device 32 includes a circular conveying belt 320, a plurality of support rollers 321, and a suction device 322.

[0019] The plurality of support rollers 321 rotatably support the conveyor belt 320. A belt drive motor (not shown) rotates one of the plurality of support rollers 321, causing the conveyor belt 320 to rotate.

[0020] The skew correction mechanism 7 conveys the sheet 9 onto the upper surface of the conveyor belt 320. The first belt conveying device 32 conveys the sheet 9 that is brought onto the upper surface of the conveyor belt 320 by the rotating conveyor belt 320. In Figures 1, 3, and 4, a first direction D1 is the conveying direction of the sheet 9 by the first belt conveying device 32. As the conveyor belt 320 rotates, the upper surface of the conveyor belt 320 moves in the first direction D1.

[0021] The tilt correction mechanism 7 is disposed upstream of the first belt conveying device 32 in the first direction D1.

[0022] The suction device 322 adheres the sheet 9 to the upper surface of the conveyor belt 320 by suction of air.

[0023] The second belt conveying device 33 takes over from the first belt conveying device 32 to convey the sheet 9 , and then sends the sheet 9 out to the second conveying path 302 .

[0024] The discharge roller pair 34 transports the sheet 9 along the second transport path 302, and then sends the sheet 9 from the second transport path 302 to a subsequent stage. For example, the subsequent stage is a discharge tray or a post-processing device.

[0025] The printing device 4 executes a printing process on the sheet 9 conveyed by the conveyor belt 320 of the first belt conveying device 32. The printing process is a process of forming an image on the sheet 9.

[0026] In this embodiment, the printing device 4 performs the printing process using an inkjet method. That is, the printing device 4 forms an image on the sheet 9 by ejecting ink onto the sheet 9. The ink is an example of a developer. The printing device 4 is an example of an image forming unit that forms an image on the sheet 9.

[0027] The printing device 4 has a plurality of ink heads 41 and a plurality of ink supply units 42, each corresponding to a different color ink. Specifically, the printing device 4 has four ink heads 41 and four ink supply units 42, corresponding to yellow, magenta, cyan, and black.

[0028] Each of the ink heads 41 has a plurality of ejection nozzles 41a that eject ink. The ink heads 41 are fixed at positions facing the surface of the conveyor belt 320 of the first belt conveying device 32. The ink supply units 42 each contain ink of a different color and supply the ink to the ink heads 41.

[0029] The drying device 5 dries the ink image on the sheet 9 by blowing hot air onto the sheet 9 being conveyed by the second belt conveying device 33 .

[0030] 1, 3, and 4, the second direction D2 is a direction that intersects with the first direction D1. In this embodiment, the second direction D2 is a width direction that is perpendicular to the first direction D1. The second direction D2 is the main scanning direction in the printing process, and the direction along the first direction D1 is the sub-scanning direction in the printing process.

[0031] The operation device 801 detects operations by a person. For example, the operation device 801 includes a plurality of operation buttons and a touch panel. The display device 802 is capable of displaying various types of information. For example, the display device 802 is a panel display device such as a liquid crystal display panel.

[0032] As shown in FIG. 2, the control device 8 includes a central processing unit (CPU) 80, a random access memory (RAM) 81, a secondary storage device 82, a signal interface 83, a communication device 84, and the like.

[0033] The CPU 80 executes various control and data processing operations by executing computer programs. The RAM 81 temporarily stores the computer programs executed by the CPU 80 and various data.

[0034] The secondary storage device 82 is a computer-readable non-volatile storage device. The secondary storage device 82 stores the computer programs executed by the CPU 80 and various data. For example, one or both of a flash memory and a hard disk drive may be used as the secondary storage device 82.

[0035] The signal interface 83 converts the detection signals of the various sensors into digital detection data and transmits the detection data to the CPU 80. Furthermore, the signal interface 83 converts the control commands output from the CPU 80 into control signals and transmits the control signals to the devices to be controlled.

[0036] The communication device 84 communicates with other devices such as the host device 100 through the network 1000. The CPU 80 communicates with other devices through the communication device 84. The host device 100 is an information processing device that requests the image forming device 10 to perform the print processing.

[0037] The CPU 80 includes a plurality of processing modules that are realized by executing the computer programs, including a transport control unit 8a and a print control unit 8b (see FIG. 2).

[0038] The conveyance control unit 8a controls the sheet conveying device 3 to control the conveyance of the sheet 9. The print control unit 8b causes the printing device 4 to execute the print process in synchronization with the conveyance of the sheet 9. Furthermore, the print control unit 8b operates the drying device 5 when the print process is executed.

[0039] Note that some or all of the processing executed by the CPU 80 may be executed by a DSP (Digital Signal Processor) or an SoC (System on a Chip), etc. Each of the CPU 80, the DSP, and the SoC is an example of a processor.

[0040] In the image forming apparatus 10, it is required that the skew of the sheet 9 be corrected more reliably in order to improve the image quality.

[0041] For example, it is required to detect the inclination angle θ1 of the conveyed sheet 9 and more reliably correct the inclination of the sheet 9 in accordance with the detection result of the inclination angle θ1 (see FIG. 7).

[0042] In this embodiment, the image forming apparatus 10 further includes a line sensor 6 (see FIGS. 1 and 3). The line sensor 6 is disposed at a specific position P1 along the upper surface of the conveyor belt 320 of the first belt conveying device 32. The line sensor 6 is disposed along a second direction D2 (see FIG. 3).

[0043] The specific position P1 is a position upstream in the first direction D1 from the multiple ink heads 41 of the printing device 4. The line sensor 6 is an image sensor that reads an image in an area along the second direction D2 at the specific position P1.

[0044] The line sensor 6 includes a light-emitting unit 6a and a plurality of photoelectric conversion elements 6b (see FIG. 3). The light-emitting unit 6a irradiates light onto a linear area along the second direction D2 on the surface of the conveyor belt 320. The plurality of photoelectric conversion elements 6b are arranged along the second direction D2.

[0045] The photoelectric conversion elements 6b each detect the amount of diffusely reflected light on the surface of the conveyor belt 320 and output a plurality of pixel signals representing the detected light amounts. The signal interface 83 includes an AFE (Analog Front End) 83a that converts the plurality of pixel signals sequentially output by the line sensor 6 into a plurality of pixel data (see FIG. 2).

[0046] The plurality of lines of pixel data output from the AFE 83a are transmitted to the CPU 80 as a plurality of line image data LD1 (see FIG. 2).

[0047] When the sheet 9 passes through the specific position P1, the line sensor 6 operates to obtain a plurality of line image data LD1. The plurality of line image data LD1 is image data X10 representing a sheet outline image X11 (see FIG. 7).

[0048] The sheet contour image X11 is an image of the contour of the sheet 9 conveyed by the first belt conveying device 32. The image data X10 is used to derive the inclination angle θ1 of the sheet 9 passing through the specific position P1 (see FIG. 7).

[0049] The line sensor 6 is an example of an image reading device that reads the outline of the sheet 9 conveyed by the first belt conveying device 32 of the sheet conveying device 3. The image data X10 is data of the read image obtained by the line sensor 6.

[0050] In this embodiment, the plurality of processing modules includes an image processing unit 8c that processes image data X10 to derive the inclination angle θ1 of the sheet 9. The skew correction mechanism 7 operates in accordance with the derived inclination angle θ1.

[0051] It is desirable that the tilt correction mechanism 7 that corrects the tilt of the seat 9 be realized by a simple mechanism. The configuration of the tilt correction mechanism 7 will be described below.

[0052] [Tilt correction mechanism 7] The tilt correction mechanism 7 includes a tilt conveying mechanism 70, a correction member 71, a first orientation adjustment mechanism 72, a support member 73, and a second orientation adjustment mechanism 74 (see FIG. 4).

[0053] The correcting member 71 is provided upstream in the first direction D1 with respect to the first belt conveying device 32. The correcting member 71 has a contact surface 71a that comes into contact with the side edge 9a of the sheet 9 at one end of the first conveying path 301 in the second direction D2. The contact surface 71a is a surface that guides the side edge 9a of the sheet 9 along the first direction D1.

[0054] The oblique conveying mechanism 70 is provided upstream in the first direction D1 from the correcting member 71. The oblique conveying mechanism 70 conveys the sheet toward the contact surface 71a along a third direction D3 oblique to the first direction D1.

[0055] In the example shown in FIG. 4, the oblique conveying mechanism 70 has a pair of rotary shafts 70a disposed obliquely with respect to the second direction D2, and a pair of rollers 70b supported by the pair of rotary shafts 70a.

[0056] The correcting member 71 is supported rotatably around the first shaft portion 71x in the second direction D2 (see FIG. 4). When the correcting member 71 rotates, the angle of the contact surface 71a with respect to the first direction D1 changes.

[0057] The first belt conveying device 32 is an example of a first conveying mechanism that conveys the sheet 9 in the first direction D1. The oblique conveying mechanism 70 is an example of a second conveying mechanism that conveys the sheet 9 toward the contact surface 71a.

[0058] The first orientation adjustment mechanism 72 is operated by inputting a drive signal to change the angle of the contact surface 71a with respect to the first direction D1. In this embodiment, the first orientation adjustment mechanism 72 is a mechanism that rotates the correcting member 71 around the first shaft portion 71x. The drive signal is output from the control device 8 to the first orientation adjustment mechanism 72.

[0059] For example, the first orientation adjustment mechanism 72 includes a control motor 721, a cam 722, and a spring 723 (see FIG. 4).

[0060] The control motor 721 rotates in a first rotation direction or a second rotation direction in response to the input of the drive signal. For example, the control motor 721 is a stepping motor or a servo motor. The control motor 721 operates in accordance with the drive signal to rotate the cam 722 around the rotation axis 722x.

[0061] The cam 722 pivots while in contact with the contacted portion 71b of the correcting member 71, thereby swinging the correcting member 71 around the first shaft portion 71x. As the correcting member 71 swings, the angle of the contact surface 71a with respect to the first direction D1 changes.

[0062] The spring 723 biases the correcting member 71 toward the cam 722, thereby maintaining the state in which the cam 722 is in contact with the contacted portion 71b of the correcting member 71.

[0063] The support member 73 supports the correcting member 71 and the first orientation adjustment mechanism 72. The support member 73 is supported so as to be rotatable about the second shaft portion 73x along the second direction D2 (see FIG. 4).

[0064] The rotation of the support member 73 changes the orientation of the support member 73 with respect to the first direction D1. Therefore, the rotation of the support member 73 changes the angle of the contact surface 71a with respect to the first direction D1.

[0065] The straightening member 71 and the support member 73 are members that are arranged independently of the first belt conveying device 32. That is, the straightening member 71 and the support member 73 are each rotatable while the first belt conveying device 32 is fixed in a certain orientation.

[0066] The second orientation adjustment mechanism 74 is manually operated to change the orientation of the support member 73 relative to the first direction D1. In this embodiment, the second orientation adjustment mechanism 74 is a mechanism that rotates the support member 73 about the second shaft portion 73x.

[0067] For example, the second direction adjustment mechanism 74 includes a base 741, a screw member 742, and a spring 743 (see FIG. 4).

[0068] The base 741 is fixed in a predetermined position and has a screw hole 741a formed therein.

[0069] The screw member 742 is fastened to a screw hole 741a of the base portion 741. The screw member 742 has a screw shaft 742a fastened to the screw hole 741a and a head portion 742b connected to the base end of the screw shaft 742a (see FIG. 4).

[0070] The tip of the screw shaft 742a abuts against the contacted portion 73a of the support member 73. The spring 743 biases the support member 73 toward the screw member 742, thereby maintaining the state in which the tip of the screw member 742 abuts against the contacted portion 73a of the support member 73.

[0071] When the screw member 742 is subjected to the manual operation of rotating the head portion 742b, the depth of fastening of the screw member 742 into the screw hole 741a changes and the support member 73 rotates around the second shaft portion 73x.

[0072] The support member 73 rotates about the second shaft portion 73x, thereby changing the orientation of the support member 73 with respect to the first direction D1.

[0073] In this embodiment, the second shaft portion 73x is disposed coaxially with the first shaft portion 71x. As a result, the sum of the adjustment angle by the first direction adjustment mechanism 72 and the adjustment angle by the second direction adjustment mechanism 74 is the adjustment angle of the contact surface 71a.

[0074] 4, the second orientation adjustment mechanism 74 further includes a screw restriction member 744. The screw restriction member 744 has an insertion portion 744a and a knob portion 744b. The insertion portion 744a is a portion that is inserted between the head portion 742b and the base portion 741 of the screw member 742. The knob portion 744b is a portion that is operated by a person.

[0075] The screw restriction member 744 moves from one of the restriction position and the retracted position to the other due to the force applied to the knob portion 744b. When the screw restriction member 744 is in the restriction position, the insertion portion 744a is located between the head portion 742b and the base portion 741. When the screw restriction member 744 is in the retracted position, the insertion portion 744a is located at a position away from between the head portion 742b and the base portion 741.

[0076] With the screw restricting member 744 in the restricting position, the screw member 742 is fastened to a reference depth that sandwiches the base 741 between the screw restricting member 744 and the base 741. This positions the support member 73 at a predetermined reference position.

[0077] When the screw member 742 is to be fastened deeper into the screw hole 741a than the reference depth, the screw restricting member 744 is moved in advance from the restricting position to the retracted position.

[0078] [First tilt correction process] In response to a print request, the conveyance control unit 8a causes the sheet conveying device 3 to convey the sheet 9. While the sheet 9 is being conveyed by the sheet conveying device 3, the conveyance control unit 8a and the image processing unit 8c execute the first skew correction process.

[0079] For example, when the print request is generated, the conveyance control unit 8a and the image processing unit 8c execute the first skew correction process in parallel with the print process. For example, the conveyance control unit 8a and the image processing unit 8c execute the first skew correction process each time one sheet 9 or multiple sheets 9 are conveyed.

[0080] Furthermore, when the print request is generated, the transport control unit 8a and the image processing unit 8c may execute the first skew correction process before the print process is executed.

[0081] An example of the procedure of the first tilt correction process will be described below with reference to the flowchart shown in FIG.

[0082] In the following description, S101, S102, ... represent identification symbols of a plurality of steps in the first tilt correction process. In the first tilt correction process, step S101 is executed first.

[0083] <Process S101> In step S101, the image processing unit 8c acquires image data X10 obtained by the operation of the line sensor 6.

[0084] For example, a plurality of line image data LD1 obtained sequentially by the operation of the line sensor 6 is stored in the RAM 81, and the image processing unit 8c obtains image data X10 consisting of the plurality of line image data LD1 stored in the RAM 81.

[0085] After executing the process of step S101, the image processing unit 8c executes the process of step S102.

[0086] <Process S102> In step S102, the image processing unit 8c extracts a sheet outline image X11 from the image data X10 obtained in step S101, and derives the inclination angle θ1 of the sheet 9 based on the sheet outline image X11.

[0087] For example, the image processing unit 8c extracts an area occupied by a plurality of pixel data exceeding a reference value from the image data X10 as a sheet area, and extracts an image of the outline of the sheet area as a sheet outline image X11.

[0088] The X coordinate in the image data X10 corresponds to a position in the second direction D2 on the upper surface of the conveyor belt 320. The Y coordinate in the image data X10 corresponds to a position in the first direction D1 on the upper surface of the conveyor belt 320.

[0089] For example, the image processing unit 8c identifies the coordinates of a first side end point Px1 and a second side end point Px2, which are end points in the X-axis direction of the sheet outline image X11 at two locations spaced apart in the Y-axis direction in the image data X10 (see FIG. 7).

[0090] Furthermore, the image processing unit 8c derives the angle formed by a line passing through the first side end point Px1 and the second side end point Px2 with respect to the Y-axis direction as the inclination angle θ1 of the sheet 9.

[0091] The image processing unit 8c may also identify the coordinates of a first tip point and a second tip point, which are endpoints in the Y-axis direction of the sheet outline image X11 at two points in the image data X10 spaced apart in the X-axis direction. In this case, the image processing unit 8c derives the angle formed by a line passing through the first tip point and the second tip point with respect to the X-axis direction as the inclination angle θ1.

[0092] After executing the process of step S102, the image processing unit 8c executes the process of step S103.

[0093] <Process S103> In step S103, the image processing unit 8c executes an angle determination process for determining the state of the derived tilt angle θ1.

[0094] Specifically, in step S103, the image processor 8c determines whether the tilt angle θ1 is within an adjustable range, which is a range within which the angle of the contact surface 71a of the correcting member 71 can be changed by the first orientation adjustment mechanism 72.

[0095] If the tilt angle θ1 is outside the adjustable range, the image processing unit 8c executes the process of step S107.

[0096] In step S103, if the tilt angle θ1 is not outside the adjustable range, the image processor 8c determines whether the tilt angle θ1 is within an allowable range or outside the allowable range, which is narrower than the adjustable range.

[0097] If the tilt angle θ1 is within the allowable range, the image processing unit 8c ends the first tilt correction process. On the other hand, if the tilt angle θ1 is outside the allowable range, the transfer control unit 8a executes the process of step S104.

[0098] <Process S104> In step S104, the transfer control unit 8a executes an improvement determination process. The improvement determination process is a process for determining whether the tilt angle θ1 has been improved or not by the operation of the first orientation adjustment mechanism 72.

[0099] In step S105, which will be described later, the transport control unit 8a operates the first orientation adjustment mechanism 72. For example, the improvement determination process is a process that determines the number of times the process of step S105 has been executed, the change in the tilt angle θ1 before and after the process of step S105 has been executed, and whether or not the tilt angle θ1 has improved.

[0100] Here, the predetermined number of times step S105 is processed is referred to as the reference number, the tilt angle θ1 before step S105 is first executed is referred to as the first tilt angle, and the tilt angle θ1 after step S105 has been processed the reference number of times is referred to as the second tilt angle.

[0101] The conveying control unit 8a determines that the inclination angle θ1 has not been improved if the number of times the processing of step S105 has been executed reaches the reference number of times and the difference between the first inclination angle and the second inclination angle is less than the reference angle difference.

[0102] When the tilt angle θ1 is determined to be unimproved, it is highly likely that an abnormality has occurred in the tilt correction mechanism 7.

[0103] On the other hand, the conveying control unit 8a determines that the inclination angle θ1 has been improved if the difference between the first inclination angle and the second inclination angle exceeds the reference angle difference before the number of times the processing of step S105 has been executed reaches the reference number of times.

[0104] If it is determined that the tilt angle θ1 is not improved, the transfer control unit 8a executes the process of step S106.

[0105] Furthermore, the transport control unit 8a executes the process of step S105 when it is determined that the tilt angle θ1 has been improved and the number of times the process of step S105 has been executed is less than the upper limit number of times.

[0106] On the other hand, when it is determined that the tilt angle θ1 has been improved and the number of times the process of step S105 has been executed reaches the upper limit number of times, the transfer control unit 8a executes the process of step S107.

[0107] A situation in which the inclination angle θ1 does not fall within the allowable range until the number of times step S105 is processed reaches the upper limit is an example of a situation in which the correction of the inclination of the seat 9 by the first orientation adjustment mechanism 72 and the processing of step S105 has reached the limit of the correctable range.

[0108] If the process of step S105 has not yet been performed, the transport control unit 8a skips the process of step S104 and performs the process of step S105.

[0109] <Process S105> In step S105, the transfer control unit 8a outputs the drive signal corresponding to the inclination angle θ1 to the first orientation adjustment mechanism 72. Specifically, the transfer control unit 8a outputs the drive signal that changes the angle of the contact surface 71a in the direction opposite to the inclination angle θ1.

[0110] For example, the transport control unit 8a derives the adjustment angle of the contact surface 71a by applying the tilt angle θ1 to a first conversion table data set in advance, and then outputs the drive signal corresponding to the direction and magnitude of the adjustment angle.

[0111] The transport control unit 8a that executes the process of step S105 is an example of an adjustment processing unit.

[0112] After the conveyance control unit 8a executes the process of step S105, when a new sheet 9 is conveyed, the image processing unit 8c and the conveyance control unit 8a execute the processes from step S101 onwards again.

[0113] <Process S106> Meanwhile, in step S106, the transport control unit 8a outputs, via one or both of the display device 802 and the communication device 84, an abnormality notification that the tilt correction mechanism 7 may be malfunctioning.

[0114] After executing the process of step S106, the transport control unit 8a ends the first tilt correction process.

[0115] The processing of steps S107 to S109 shown below is executed when the derived result of the tilt angle θ1 is outside the allowable range under the circumstance that the correction of the tilt of the seat 9 by the first orientation adjustment mechanism 72 and the processing of step S105 has reached the limit of the correctable range (see steps S103 and S104). In this embodiment, the processing of steps S107 to S109 is also executed when the tilt angle θ1 is outside the range in which the angle of the contact surface 71a can be changed by the first orientation adjustment mechanism 72 (see step S103).

[0116] <Process S107> In step S107, the transfer control unit 8a sets the adjustment operation amount for the second orientation adjustment mechanism 74 based on the result of deriving the most recent tilt angle θ1.

[0117] In this embodiment, the adjustment operation amount is the direction in which the screw member 742 is turned and the amount by which the screw member 742 is turned.

[0118] For example, the transport control unit 8a derives the adjustment operation amount by applying the tilt angle θ1 to second conversion table data that has been set in advance.

[0119] The transport control unit 8a that executes the process of step S107 is an example of an operation amount setting unit that sets the adjustment operation amount.

[0120] After carrying out the process of step S107, the transfer control unit 8a carries out the process of step S108.

[0121] <Process S108> In step S108, the transport control unit 8a outputs adjustment guide information that prompts adjustment by the second orientation adjustment mechanism 74 via one or both of the display device 802 and the communication device 84.

[0122] In this embodiment, the transport control unit 8a outputs the adjustment guide information including information on the adjustment operation amount set in step S107.

[0123] 5, the second orientation adjustment mechanism 74 has an adjustment scale 745 that indicates the rotational position of the screw member 742. By turning the screw member 742 while checking the adjustment scale 745, the operator can easily turn the screw member 742 by the amount of the adjustment operation.

[0124] The display device 802 and the communication device 84 are each an example of an information output device. The transport control unit 8a that executes the processing of step S108 is an example of a notification processing unit that outputs the adjustment guidance information through the information output device.

[0125] After carrying out the process of step S108, the transfer control unit 8a carries out the process of step S109.

[0126] <Process S109> In step S109, the transport control unit 8a checks whether or not an adjustment completion operation has been performed on the operation device 801. The adjustment completion operation is an operation indicating that the adjustment of the orientation of the support member 73 by the second orientation adjustment mechanism 74 has been completed.

[0127] The transport control unit 8a waits until the adjusted operation is performed on the operation device 801. When the adjusted operation is performed on the operation device 801, the transport control unit 8a shifts the process to step S101. As a result, when a new sheet 9 is transported, the image processing unit 8c and the transport control unit 8a execute the processes from step S101 onwards again.

[0128] [Second tilt correction process] In this embodiment, the conveyance control unit 8a and the image processing unit 8c execute the second skew correction process as a process for initial adjustment of the image forming apparatus 10.

[0129] The conveyance control unit 8a and the image processing unit 8c execute the second skew correction process while the sheet 9 is being conveyed by the sheet conveying device 3.

[0130] For example, when a predetermined adjustment start operation is performed, the conveyance control unit 8a causes the sheet conveying device 3 to convey the sheet 9, and the conveyance control unit 8a and the image processing unit 8c then execute the second skew correction process. The conveyance control unit 8a and the image processing unit 8c execute the second skew correction process under a condition where the print process is not being executed.

[0131] An example of the procedure of the second tilt correction process will be described below with reference to the flowchart shown in FIG.

[0132] In the following description, S201, S202, ... represent identification symbols of a plurality of steps in the second tilt correction process. In the second tilt correction process, step S201 is executed first.

[0133] <Process S201> In step S201, the transfer control unit 8a holds the correcting member 71 at a predetermined initial position by outputting the drive signal to the first orientation adjustment mechanism 72. When the correcting member 71 is located at the initial position, the contact surface 71a forms a predetermined reference angle with respect to the first direction D1. For example, the reference angle is 0 degrees.

[0134] After the transport control unit 8a executes the process of step S201, the image processing unit 8c executes the process of step S202.

[0135] <Process S202> In step S202, the image processing unit 8c acquires image data X10 obtained by the operation of the line sensor 6, similarly to step S101 of the first tilt correction process.

[0136] After executing the process of step S202, the image processing unit 8c executes the process of step S202.

[0137] <Process S203> In step S203, the image processing unit 8c extracts a sheet outline image X11 from the image data X10 obtained in step S202, and derives the inclination angle θ1 of the sheet 9 based on the sheet outline image X11. The process in step S203 is similar to the process in step S102 of the first skew correction process.

[0138] After executing the process of step S203, the image processing unit 8c executes the process of step S204.

[0139] <Process S204> In step S204, the image processing unit 8c executes the angle determination process for determining the state of the tilt angle θ1, similar to step S103 of the first tilt correction process.

[0140] That is, the image processing unit 8c determines whether the tilt angle θ1 is within the allowable range or outside the allowable range. However, in step S204, the process of determining whether the tilt angle θ1 is outside the adjustable range may be omitted.

[0141] If the tilt angle θ1 is within the allowable range, the image processing unit 8c ends the second tilt correction process. On the other hand, if the tilt angle θ1 is outside the allowable range, the transfer control unit 8a executes the process of step S205.

[0142] <Process S205> In step S205, the transport control unit 8a executes the improvement determination process in the same manner as in step S104 of the first tilt correction process.

[0143] However, the second tilt correction process does not include the process of step S105 in the first tilt correction process, and therefore, in step S205, the process of comparing the number of times the process of step S105 has been executed with the upper limit number of times is omitted.

[0144] If it is determined that the tilt angle θ1 is not improved, the transfer control unit 8a executes the process of step S206.

[0145] On the other hand, if it is determined that the tilt angle θ1 has been improved, the transfer control unit 8a executes the process of step S207.

[0146] <Process S206> Meanwhile, in step S206, the transport control unit 8a outputs the abnormality notification via one or both of the display device 802 and the communication device 84, similar to step S106 of the first tilt correction process.

[0147] After executing the process of step S206, the transport control unit 8a ends the second tilt correction process.

[0148] <Process S207> In step S207, the transfer control unit 8a sets the adjustment operation amount for the second orientation adjustment mechanism 74 based on the derived result of the most recent tilt angle θ1. The process of step S207 is similar to the process of step S107 of the first tilt correction process.

[0149] After executing the process of step S207, the transfer control unit 8a executes the process of step S208.

[0150] <Process S208> In step S208, the transport control unit 8a outputs the adjustment guide information through one or both of the display device 802 and the communication device 84. The process of step S208 is similar to the process of step S108 of the first tilt correction process.

[0151] After executing the process of step S208, the transfer control unit 8a executes the process of step S209.

[0152] <Process S209> In step S209, the transport control unit 8a checks whether or not the adjusted operation has been performed on the operation device 801, similarly to step S109 of the first tilt correction process.

[0153] The transport control unit 8a waits until the adjusted operation is performed on the operation device 801. When the adjusted operation is performed on the operation device 801, the transport control unit 8a shifts the process to step S201. As a result, when a new sheet 9 is transported, the transport control unit 8a and the image processing unit 8c execute the processes from step S201 onwards again.

[0154] By employing the skew correction mechanism 7, the skew of the conveyed sheet 9 can be corrected by a simple mechanism.

[0155] Furthermore, in the tilt correction mechanism 7, the second orientation adjustment mechanism 74 roughly adjusts the tilt of the contact surface 71a in accordance with large differences in the characteristics of the seat 9, and the first orientation adjustment mechanism 72 can adjust the tilt of the contact surface 71a with high precision in accordance with variations in the characteristics of the seat 9. Therefore, the tilt correction mechanism 7 can accommodate a variety of seat 9 characteristics.

[0156] [Notes on the Invention] The following is a summary of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0157] <Appendix 1> a first conveying mechanism that conveys a sheet; a correcting member provided upstream of the first conveying mechanism in a conveying direction of the sheet by the first conveying mechanism, the correcting member having a contact surface that comes into contact with a side edge of the sheet at one end in a width direction perpendicular to the conveying direction in the conveying path of the sheet; a first orientation adjustment mechanism that operates in response to an input of a drive signal and changes the angle of the contact surface with respect to the conveyance direction; a second conveying mechanism that is provided upstream of the correcting member in the conveying direction and that conveys the sheet toward the contact surface in a direction oblique to the conveying direction; a support member that supports the correction member and the first orientation adjustment mechanism; a second orientation adjustment mechanism that is manually operated to change the orientation of the support member relative to the conveying direction;

[0158] <Appendix 2> the first orientation adjustment mechanism is a mechanism that rotates the correcting member around a first shaft portion, The sheet conveying device described in Appendix 1, wherein the second orientation adjustment mechanism is a mechanism that rotates the support member around a second shaft portion that is arranged coaxially with the first shaft portion.

[0159] <Appendix 3> the second orientation adjustment mechanism includes a base portion having a screw hole formed therein and a screw member fastened to the screw hole; The sheet conveying device according to claim 1 or 2, wherein the screw member is manually operated to change the depth of fastening of the screw member into the screw hole and to change the orientation of the support member.

[0160] <Appendix 4> 4. The sheet conveying device according to claim 1, wherein the first conveying mechanism conveys the sheet carried onto a conveying belt by a rotating conveying belt.

[0161] <Appendix 5> a sheet conveying device according to any one of Supplementary Note 1 to Supplementary Note 4; an image forming unit that forms an image on the sheet conveyed by the first conveying mechanism; an image reading device that reads the outline of the sheet conveyed by the sheet conveying device; an image processing unit that derives an inclination angle of the sheet with respect to the conveying direction based on a read image obtained by the image reading device; an adjustment processing unit that outputs the drive signal to the first orientation adjustment mechanism based on the derived result of the tilt angle.

[0162] <Appendix 6> The image forming device described in Appendix 5 is provided with a notification processing unit that outputs adjustment guidance information through an information output device to encourage adjustment by the second orientation adjustment mechanism when the derived result of the inclination angle falls outside the allowable range under a situation where the correction of the sheet inclination by the processing of the first orientation adjustment mechanism and the adjustment processing unit has reached the limit of the correctable range.

[0163] <Appendix 7> an operation amount setting unit that sets an adjustment operation amount for the second orientation adjustment mechanism based on a result of deriving the inclination angle under a situation where correction of the inclination of the seat by the processing of the first orientation adjustment mechanism and the adjustment processing unit has reached the limit of the correctable range; The image forming apparatus according to claim 6, wherein the notification processing unit outputs the adjustment guide information including information on the adjustment operation amount. [Explanation of symbols]

[0164] 3: Sheet transport device 4: Printing device 6: Line sensor 7: Tilt correction mechanism 8: Control device 10: Image forming device 32: First belt conveyor 33: Second belt conveyor 70: Diagonal transport mechanism 71: Corrective element 71a: Contact surface 71x: First shaft 72: First orientation adjustment mechanism 73: Support member 73x: 2nd shaft part 74: Second direction adjustment mechanism 320: Conveyor belt 741: Base 742: Screw parts X10: Image data X11: Sheet outline image

Claims

1. a first conveying mechanism that conveys a sheet; a correcting member provided upstream of the first conveying mechanism in a conveying direction of the sheet by the first conveying mechanism, the correcting member having a contact surface that comes into contact with a side edge of the sheet at one end of a width direction of the sheet in a conveying path of the sheet that is perpendicular to the conveying direction; a first orientation adjustment mechanism that operates in response to an input of a drive signal and changes the angle of the contact surface with respect to the conveyance direction; a second conveying mechanism provided upstream of the correcting member in the conveying direction and configured to convey the sheet toward the contact surface in a direction oblique to the conveying direction; a support member that supports the correction member and the first orientation adjustment mechanism; a second orientation adjustment mechanism that is manually operated to change the orientation of the support member relative to the conveying direction.

2. the first orientation adjustment mechanism is a mechanism that rotates the correcting member around a first shaft portion, The sheet transport device according to claim 1 , wherein the second orientation adjustment mechanism is a mechanism that rotates the support member around a second shaft portion that is disposed coaxially with the first shaft portion.

3. the second orientation adjustment mechanism includes a base portion having a screw hole formed therein and a screw member fastened to the screw hole; 3. The sheet conveying device according to claim 1, wherein the manual operation of the screw member changes the depth of fastening of the screw member into the screw hole and also changes the orientation of the support member.

4. 3. The sheet conveying device according to claim 1, wherein the first conveying mechanism conveys the sheet carried onto a rotating conveying belt.

5. a sheet conveying device according to claim 1 or 2; an image forming unit that forms an image on the sheet conveyed by the first conveying mechanism; an image reading device that reads the outline of the sheet conveyed by the sheet conveying device; an image processing unit that derives an inclination angle of the sheet with respect to the conveying direction based on a read image obtained by the image reading device; an adjustment processing unit that outputs the drive signal to the first orientation adjustment mechanism based on the derived result of the tilt angle.

6. 6. The image forming apparatus according to claim 5, further comprising a notification processing unit that outputs, via an information output device, adjustment guidance information that prompts adjustment by the second orientation adjustment mechanism when the derived result of the inclination angle falls outside the allowable range under a situation where the correction of the sheet inclination by the processing of the first orientation adjustment mechanism and the adjustment processing unit has reached the limit of the correctable range.

7. an operation amount setting unit that sets an adjustment operation amount for the second orientation adjustment mechanism based on a result of deriving the inclination angle under a situation where correction of the inclination of the seat by the processing of the first orientation adjustment mechanism and the adjustment processing unit has reached a limit of the correctable range, The image forming apparatus according to claim 6 , wherein the notification processing unit outputs the adjustment guide information including information on the adjustment operation amount.

Images