JP2002060097A - Sheet conveying equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly correct the dislocation of a sheet on a side guide basis at all times. SOLUTION: This sheet conveying equipment comprises a side guide having a side reference surface disposed, parallel with a sheet conveying direction, at one end part of a sheet conveying passage for feeding a sheet therethrough, a diagonal moving roller disposed at a specified angle relative to the sheet conveying direction and diagonally moving the sheet to the side reference surface side while nipping the sheet in the sheet feeding passage, an angle varying motor 44 forming a drive source for changing the tilt angle of the diagonal moving roller relative to the sheet conveying direction, an operation panel 23 and a sheet detection sensor 55 for acquiring sheet related information related to the sheet to be fed, a skew detection sensor 56 for detecting the dislocated state of the sheet in the sheet conveying passage, and a controller 54 for setting angle changing conditions when the tile angle of the diagonal moving roller is changed based on the sheet-related information and the state of positional displacement of the sheet and controlling the driving of the angle varying motor 44 according to the angle change conditions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying apparatus used for an image forming apparatus or the like, and more particularly to a technique for correcting a positional deviation (skew or the like) of a sheet during sheet conveyance.

[0002]

2. Description of the Related Art Generally, an image forming apparatus such as a copying machine includes:
A sheet conveying device that conveys a sheet-shaped document or sheet (hereinafter, collectively referred to as a sheet) is incorporated. Further, in an image forming apparatus having a sheet conveying device, if a sheet being conveyed is skewed or is displaced in a direction perpendicular to the sheet conveying direction, an image is formed in a state shifted from the sheet. Will be. Particularly, in a copying machine or the like having a two-sided copy function, after forming an image on the first side, the sheet is reversed by the reversing means, and then the image is formed on the second side. Or, if the position is shifted in the direction orthogonal to the transport direction, the images on the first surface and the second surface will be shifted.

[0003] For this reason, the sheet conveying apparatus is provided with a skew correcting means for correcting a skew of the sheet being conveyed, a positional deviation of the sheet in a direction perpendicular to the conveying direction, that is, a side registration (hereinafter abbreviated as a side registration). A sheet positioning mechanism is provided.

As this type of sheet conveying apparatus, for example,
Japanese Patent Application Laid-Open No. Sho 62-230545 discloses a method in which a side guide having a side reference surface is provided at one end of a sheet conveying path, and a skew roller for skewing a sheet is provided on the side reference surface. The document describes an apparatus provided with an angle changing means for changing an inclination angle of a skew roller with respect to a sheet conveying direction.

In the sheet conveying apparatus described in the above publication, the inclination angle of the skew roller is set large in the initial state, and the sheet is skewed toward the side reference surface by the skew roller. Thereafter, when the sheet is conveyed until the leading edge of the sheet hits the shutter, the nip (nipping) of the sheet by the skew roller is released and the conveyance is temporarily stopped based on a signal generated by a timer or counting of the number of pulses, and the state is changed. Is changed so that the inclination angle of the skew roller becomes small. Thereafter, the sheet is nipped again by the skew roller at the same time when the shutter is opened, and the conveyance is restarted.

[0006]

However, the sheet conveying device described in the above publication has the following disadvantages.

First, since the leading end of the sheet skewed toward the side reference surface by the skew roller is brought into contact with the shutter, the side edge of the sheet is aligned with the side reference surface by the skew roller. However, the skew correction is performed on the basis of the shutter because the leading edge of the sheet is hit against the shutter with a strong force. Therefore, when there is a deviation in the perpendicularity of the sheet due to a deviation at the time of cutting the sheet, the skew correction is performed on the basis of the shutter as described above, so that the inclination of the sheet side edge with respect to the sheet conveyance direction (hereinafter referred to as side skew). ). Further, in the case of a copying machine having a two-sided copying function, when the sheet is reversed by the reversing means, the leading edge and the trailing edge of the sheet are switched in the sheet conveying direction.
If you touch the end of the sheet to the shutter,
The images on the first surface and the second surface are shifted.

Second, since the sheet is temporarily stopped during the conveyance, the sheet conveyance efficiency is reduced. As a result, the productivity of the image forming apparatus deteriorates.

Third, since the inclination angle of the skew roller is changed in two stages by switching the solenoid on / off, the sheet is skewed with the skew roller as the initial angle (large inclination angle). In such a case, it is impossible to achieve both the securing of the correction amount when the sheet is thick paper and the prevention of buckling when the sheet is thin paper. That is, if the initial angle of the skew roller is set to be large in order to secure a sufficient correction amount when the sheet is a thick sheet, buckling occurs when the sheet is a thin sheet. Further, if the initial angle of the skew roller is set to a small value in order to prevent buckling when the sheet is thin paper, the correction amount will be insufficient when the sheet is thick paper.

Fourth, since the timing of changing the inclination angle of the skew roller is managed by a timer, counting the number of pulses, or the like, for example, when a skewed sheet is skewed by the skew roller. In this case, buckling occurs in a thin paper sheet, and when a highly skewed sheet is skewed by a skew roller, the correction amount may be insufficient.

[0011]

In a sheet conveying apparatus according to the present invention, a side guide having a side reference surface arranged at one end of a sheet conveying path through which a sheet is conveyed in parallel with a sheet conveying direction is provided. Sheet skew means arranged at a predetermined inclination angle with respect to the sheet conveyance direction, skew the sheet toward the side reference surface side while nipping the sheet in the sheet conveyance path, and sheet skew means with respect to the sheet conveyance direction. Angle changing means for changing the inclination angle, and control for controlling the driving of the angle changing means based on at least one of information on a position shift state of the sheet in the sheet conveying path and sheet related information relating to the sheet to be conveyed. Means.

In the sheet conveying apparatus having the above configuration, the control means controls the driving of the angle changing means based on the state of the sheet being displaced in the sheet conveying path (for example, the state of the lead skew, side skew, side registration, etc.). As a result, the inclination angle of the sheet skew feeding means is changed under conditions suitable for the position shift state of the sheet. Further, the control unit controls the driving of the angle changing unit based on sheet-related information (for example, the basis weight, paper quality, size, etc. of the sheet) related to the sheet to be conveyed,
The inclination angle of the sheet skew feeding means is changed under conditions suitable for the sheet-related information. Further, the control means controls the drive of the angle changing means based on both the sheet positional deviation state and the sheet-related information, so that the inclination angle of the sheet skew feeding means is adjusted to both the sheet positional deviation state and the sheet-related information. It will be changed under suitable conditions.

Further, in the sheet conveying apparatus having the above-mentioned structure, the tilt angle of the sheet skew feeding means is controlled by driving the angle changing means in a state where the sheet is nipped by the sheet skew feeding means in accordance with a control command from the control means. By making the change, the conveyance of the sheet is continuously performed even during the skew correction of the sheet. Further, when changing the inclination angle of the sheet skew means, the drive of the angle changing means is controlled so that the inclination angle of the sheet skew means gradually changes, or the nip pressure of the sheet skew means with respect to the sheet is reduced. In this state, by changing the inclination angle of the sheet skew feeding means by driving the angle changing means, it is possible to prevent a temporary increase in the skew amount due to the angle change.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing the entire configuration of a full-color image forming apparatus to which the present invention is applied. The illustrated full-color image forming apparatus 1 mainly includes an image reading unit 2, an image forming unit 3, and a sheet conveying system 4.

The image reading section 2 reads an image of a document set on a transparent document table (platen glass). The image reading unit 2 includes, for example, an optical scanning system including a lamp, a mirror, and a carriage, a lens system that forms an optical image read and scanned by the optical scanning system, and an optical system that forms an image by the lens system. An image reading sensor (for example, a CCD sensor) that receives an image and converts it into an electric signal is provided.

The image forming section 3 includes four photosensitive drums 5, 6, 7, and 8 corresponding to black (K), Y (yellow), M (magenta), and C (cyan), and respective photosensitive drums. Four primary transfer rollers 9, 10, 1 corresponding to the body drum
1, 12; an intermediate transfer belt 13;
4, a vacuum transport unit 15, and a fixing unit 16, which is a quadruple tandem type configuration.

Around each of the photosensitive drums 5, 6, 7, and 8, a charger and a laser writing device (laser R)
OS), a developing device, a cleaner, and the like. The charger uniformly charges the surface of the photosensitive drum, and the laser writing device forms an electrostatic latent image on the surface of the photosensitive drum charged by the charger by laser irradiation. The developing device supplies toner as a developer to the surface of the photosensitive drum to visualize (develop) the electrostatic latent image to form a toner image, and the cleaner does not need to remain on the photosensitive drum. This is for cleaning the toner.

On the other hand, each primary transfer roller 9,
The reference numerals 10, 11, and 12 are arranged in the vicinity of the corresponding photosensitive drums 5, 6, 7, and 8 via the intermediate transfer belt 13 to face each other. These primary transfer rollers 9,
10, 11, and 12 are the photosensitive drums 5 and 5 as described above.
The toner images formed on 6, 7, and 8 are transferred (primary transfer) onto the intermediate transfer belt 13. The intermediate transfer belt 13 is stretched in a loop by a plurality (five in the illustrated example) of belt support rollers.

The secondary transfer roller 14 is used for the intermediate transfer belt 1.
3 and are arranged in a state of facing. This secondary transfer roller 1
Reference numeral 4 denotes a unit for transferring (secondarily transferring) the toner image formed on the intermediate transfer belt 13 to a sheet (paper) as described above, and the transfer position (secondary transfer position) of the toner image is determined by the image forming unit. 3 is the image forming processing position. The vacuum transport section 15 transports the sheet on which the toner image has been transferred by the secondary transfer roller 14 to the fixing device 16. The fixing device 16 fixes a toner image on a sheet by heating and pressing or the like.

On the other hand, the sheet transport system 4 includes the first tray 1
7. Each of the sheets stored in the second tray 18 and the third tray 19 is conveyed along a predetermined route. In the vicinity of each of the trays 17, 18, and 19, corresponding delivery rollers 20, 21, and 22 are provided. Each of the delivery paths 0 to 20, 21, 22
Nips the called sheets separated one by one from the corresponding trays 17, 18, and 19 to temporarily stop them on the sheet conveyance path, and at the timing based on a predetermined start signal, to the downstream side in the sheet conveyance direction. The sheet is sent out. An operation panel 23 serving as a user interface is provided near the image reading unit 2.
Is provided. For example, when a sheet to be subjected to image formation is a sheet, the operation panel 23 selects a tray for accommodating the sheet, and determines the basis weight, paper quality, thickness, size, etc. of the sheet accommodated in each tray. Is used when the user specifies. In addition, items other than the tray selection may be specified for each tray using switches provided near the tray, for example. In such a case, the items are automatically specified by the tray selection. Will be.

Here, each of the feed rollers 20, 2
Rollers for sheet conveyance are appropriately arranged in a series of sheet conveyance paths R1 to R5 from the sheet feeding position by the image forming units 1 and 22 to the discharge tray 24 via the image forming processing position in the image forming unit 3. Has been established. The sheets stored in the first tray 17 are sent out by the sending-out roller 20, and then sent to the merged conveying section 25 via the first sheet conveying path R1. Also, the second
The sheets accommodated in the tray 18 of the feeding roller 2
After being sent out by the first sheet feeder 1, the sheet is sent to the merged conveying section 25 via the first sheet conveying path R1. On the other hand, the sheets accommodated in the third tray 19 are
Is directly sent to the conveyer 25.

The sheet sent to the merging and conveying section 25 is sent to the image forming processing position in the image forming section 3 via the second sheet conveying path R2. Further, the sheet that has passed the image forming processing position is sent to the fixing device 16 by the vacuum conveyance unit 15 and then discharged to the discharge tray 24 via the third sheet conveyance path R3. On the other hand, a sheet on which images are formed on both sides (first and second sides) passes through the fixing device 16 and is then sent to the two-side reversing unit 28 via the fourth sheet conveying path R4. Then, after being turned upside down, the fifth sheet conveying path R5
And is sent again to the merging and conveying section 25.

In such sheet conveyance paths R1 to R5, a skew correction unit 26 and a registration roller 27 are provided in the second sheet conveyance path R2. The skew correction unit 26 corrects the skew of the sheet conveyed on the second sheet conveyance path R2. Skew correction unit 26
Will be described in detail later. The registration rollers 27 are composed of a pair of rollers held in pressure contact with each other, and while nipping (pinching) the sheet between the pair of rollers, the rotation of the roller moves the sheet to the image forming processing position. It is what you send. At this time, the timing control means (not shown) adjusts the sheet conveying speed by the registration roller 27,
The arrival timing of the toner image at the image forming processing position and the arrival timing of the sheet are matched.

The sheet conveying paths R3 and R5 are provided with curl correction units 29 and 30, respectively. Each of the curl correction units 29 and 30 is for correcting the curl of the sheet that occurs when the fixing unit 16 fixes the toner image.

Next, the operation of the full-color image forming apparatus 1 having the above configuration will be described. First, when an image of a document is read by the image reading unit 2, a toner image is formed by the image forming unit 3 based on the image signal obtained thereby. In the image forming section 3, the four photoconductor drums 3, 4, 5, and 6 are rotationally driven, and each of the photoconductor drums 5, 6, and 6 is driven by a corresponding charger, laser writing device (laser ROS), and developing device. , 7, and 8 are sequentially formed with K, Y, M, and C toner images. The toner images of each color thus formed are sequentially transferred by the primary transfer rollers 9, 10, 11 and 12 to the intermediate transfer belt 1.
3 is over-transferred. Thereby, the intermediate transfer belt 1
3 is a multi-color (full color) with four color toners superimposed
Is formed. The toner image thus formed on the intermediate transfer belt 13 is
3 and sent to an image forming processing position (secondary transfer position).

On the other hand, the sheet of the tray selected by the user using the operation panel 23 or the sheet of the tray selected by the automatic selection function is adjusted by the registration roller 27 in accordance with the timing at which the toner image reaches the image forming processing position. Sent in. For example, assuming that the tray selected as described above is the first tray 17, the sheet sent out by the sending roller 20 is sent to the merging and conveying unit 25 via the first sheet conveying path R1, and furthermore, The sheet is fed to the image forming processing position by the registration roller 27 via the second sheet conveyance path R2.

Thus, at the image forming position of the image forming section 3, the toner image (full color image) carried on the intermediate transfer belt 13 is collectively transferred (secondarily transferred) to the sheet by the secondary transfer roller 14. Thereafter, the sheet is sent to the fixing device 16 by the vacuum conveying section 15, where the sheet is subjected to the fixing process of the toner image, and then discharged to the discharge tray 24 via the third sheet conveying path R <b> 3.

However, the sheet on which image formation is performed on both sides passes through the fourth sheet conveying path R4, and then the two-side reversing unit 2
The sheet is then turned over and sent to the fifth sheet conveying path R5. Thereafter, the sheet for duplex copying is conveyed along the fifth sheet conveying path R5, and then the delivery rollers 3 provided near the end of the sheet conveying path R5.
Pause at 1 (or nip). Then, the timing of the double-sided copy sheet is adjusted by the rotation of the feed roller 31 based on a predetermined restart signal, and the double-sided copy sheet is sent again to the merging and conveying section 25. Thereafter, after the toner image is transferred and fixed to the sheet in the same manner as described above, the sheet is discharged to the discharge tray 24 via the third sheet conveyance path R3.

FIG. 2 is a schematic plan view showing the structure of the skew correction unit 26, and FIG.
FIG. 6 is a schematic side view when 6 is viewed from the upstream side in the sheet conveying direction. As shown in the figure, a side guide 32 is provided at one end of a sheet conveying path (second sheet conveying path R2 in the present embodiment) through which the sheet is conveyed. The side guide 32 is formed in a substantially U-shape when viewed from the sheet conveyance direction Y, and has a side reference surface 3
3 are integrally formed. Furthermore, the side guide 32
The substantially U-shaped entrance portion is formed to open outward (substantially V-shaped) so that the side end of the sheet can be easily taken in. Further, the side guide 32 is fixed to the main body frame 34 of the full-color image forming apparatus 1 (see FIG. 1) in a state where the side reference surface 33 is arranged parallel to the sheet conveying direction Y.

A support member 35 bent substantially in an L-shape is attached to the main body frame 34. One end of a base 36 is placed on the upper surface of the support member 35, and a skew roller 37 is mounted on the base 36. The base 36 has a rectangular plate-like structure in a plan view, and one end thereof is rotatably supported on a support member 35. That is, the support member 3
A rotating support shaft (round pin) 38 which stands substantially vertically is provided on the upper surface of 5.
Is provided. The rotation support shaft 38 is disposed so as to be located substantially directly below the skew roller 37 mounted on the base 36. On the other hand, a through hole (round hole) (not shown) is provided on one end side of the base 36, and the base 36 is rotatably supported by fitting the through hole to the rotation support shaft 38. Have been.

On the other hand, the other end of the base 36 is
9. Link guides 40 are arranged at both ends of the link arm 39 in the longitudinal direction, and the link guides 40 support the link arm 39 movably in the sheet conveying direction Y. Also,
An engaging pin 4 is provided at a substantially intermediate portion of the link arm 39 in the longitudinal direction.
1 is erected. The engagement pin 41 is fitted in a long hole 42 provided in the base 36. Further, a rack gear 43 is formed at one end of the link arm 39. On the other hand, a pinion gear 45 is mounted on the output shaft (rotation drive shaft) of the angle changing motor 44, and the rack gear 43 is meshed with the pinion gear 45.
The angle changing motor 44 serves as a driving source when changing the inclination angle of the skew roller 37. As the angle changing motor 44, a stepping motor or a DC motor is used.

On the other hand, the skew roller 37 is mounted on one end of a roller rotating shaft 46 having a round shaft shape. The roller rotation shaft 46 is rotatably supported by a bearing member 47 formed in a substantially U shape. Also, the roller rotating shaft 4
A driven gear 48 is mounted on the other end of the motor 6. On the other hand, the output shaft (rotation drive shaft) of the roller rotation motor 49
Is mounted with a drive gear 50, and the driven gear 48 is meshed with the drive gear 50. Roller rotation motor 4
Reference numeral 9 denotes a driving source for rotating the skew roller 37, which is mounted on the base 36 via a spacer member 51. As the roller rotation motor 49, a stepping motor, a DC motor, or the like is used.

The pinch roller 52 is pressed against the skew roller 37 mounted on the base 36 from above. The pinch roller 52 rotates according to the rotation of the skew roller 37. The pinch roller 52 is pressed against the skew roller 37 using an elastic member such as a spring, and the pressing force is changed using an actuator such as a plunger.
It has a configuration that can be changed into stages.

Further, a pair of upper and lower chute members 53A, 53B are disposed at substantially the same height position as the side guide 32. The pair of chute members 53A, 53B
This guides sheet conveyance on the sheet conveyance path.

When the roller rotation motor 49 is driven in the skew correction section 26 having the above configuration, the driving force (rotational force) is transmitted to the roller rotation shaft 46 via the driving gear 50 and the driven gear 48. Thereby, the skew roller 37 rotates integrally with the roller rotation shaft 46. At this time, the rotation direction and the rotation speed of the skew roller 37 correspond to the rotation direction and the rotation speed of the roller rotation motor 49.

When the angle changing motor 44 is driven, the driving force (rotational force) is transmitted to the link arm 39 via the pinion gear 45 and the rack gear 43. At this time, the rotational motion of the angle changing motor 44 is converted into the linear motion of the link arm 39 by the power transmission by the rack and pinion. Thereby, the angle changing motor 44
The link arm 39 moves in parallel with the sheet conveying direction Y according to the drive (rotation direction, rotation speed, rotation amount, etc.), and the base 36 rotates about the rotation support shaft 38 in conjunction with the movement. As a result, the skew roller 3 with respect to the sheet conveying direction Y
7 changes.

In this embodiment, the inclination angle θ of the skew roller 37 is controlled by driving the angle changing motor 44.
Can be arbitrarily changed, and in the angle change range, the inclination angle θ of the skew roller 37 is changed to a state of zero, that is, a state in which the skew roller 37 is parallel to the sheet conveying direction Y. It is configured to obtain.

FIG. 4 is a control block diagram of the sheet conveying system 4 according to the present embodiment. In FIG. 4, the controller 5
Numeral 4 controls the overall operation of the sheet conveying system 4.
For example, it is configured by a CPU having an arithmetic processing function, a ROM storing a control program, a RAM storing control data, and the like. However, FIG. 4 shows only the block configuration related to the operation control of the skew correction unit 26 in the sheet transport system 4.

A roller rotation motor 49 and an angle changing motor 44 to be controlled are electrically connected to the controller 54 via a motor driver or the like, respectively.
Thus, the motors 49 and 44 are driven to rotate based on a control command from the controller 54.

The controller 54 has the sheet detection sensor 5 together with the operation panel 23 (see FIG. 1).
5 is electrically connected to the skew detection sensor 56, whereby information from the operation panel 23 and the sensors 55 and 56 is notified to the controller 54. The sheet detection sensor 55 detects the state of a sheet to be conveyed as one of sheet-related information (described later). The skew detection sensor 56 detects a state of the sheet being displaced in the sheet conveyance path (described later).

The operation panel 23 and the sheet detection sensor 55 acquire sheet-related information relating to a sheet to be conveyed and notify the controller 54 of the sheet-related information. The sheet-related information acquired by the operation panel 23 includes tray selection information as described above,
The basis weight, paper quality, thickness of the sheets stored in each tray,
There is information such as size. When the user selects double-sided copying via the operation panel 23, whether to form an image on the first side or an image on the second side of the sheet conveyed toward the image forming processing position Is also sent to the controller 54 as one item of the sheet-related information.

On the other hand, the sheet-related information that can be acquired (detectable) by the sheet detection sensor 55 includes information such as the basis weight, paper quality, thickness, rigidity, charge amount, water content, and temperature of the sheet. Regarding the duplicated sheet-related information items (basis weight, paper quality, thickness, etc.), either one of the information may be acquired by the controller 554 side. Further, it is not always necessary to acquire all the sheet-related information described here, and if there is sheet-related information other than the above items, it may be acquired together.

Here, a specific configuration example of the sheet detection sensor 55 will be described. First, the sheet detection sensor 55
FIG. 5 is for detecting the paper quality of the sheet.
The configuration shown in FIG. In such a configuration, a reflection-type photosensor 57 is provided in the tray or on the upstream side of the skew roller 37 in the sheet conveyance direction in a direction obliquely facing the sheet P. The light emitting unit and the light receiving unit of the photo sensor 57 are arranged in the same direction.

In the above configuration, when the sheet P is coated paper, the surface of the sheet becomes very smooth, so that most of the sensor light emitted from the light emitting unit is in the form of a sheet P as indicated by a solid line arrow in the drawing. Is reflected (specular reflection) in a direction different from that of the photosensor 57 on the surface of the photosensor 57. Therefore, the light reflected on the surface of the sheet P is not received by the light receiving section of the photo sensor 57. On the other hand, when the sheet P is plain paper, the surface of the sheet becomes relatively rough, so that the sensor light emitted from the light emitting unit is reflected (diffusely reflected) on the surface of the sheet P in multiple directions. As a result, a part of the light reflected on the surface of the sheet P returns to the photo sensor 57 side as shown by the broken line in the figure and is received by the light receiving unit. As a result, a large difference occurs in the amount of light received by the light receiving unit depending on whether the sheet P is coated paper or plain paper, and the output signal (on / off state or output level) of the photo sensor 57 switches according to the amount of received light. Therefore, by reading the output signal of the photosensor 57, it is possible to detect the paper quality (whether coated paper or plain paper in this example) of the sheet P to be conveyed.

When the sheet detection sensor 55 detects the thickness of the sheet, the configuration shown in FIG. 5B can be adopted. In such a configuration, a pinch roller 59 is held in pressure by a spring or the like against the transport roller 58 rotatably supported at a fixed position. Then, a displacement sensor 60 is provided near the pinch roller 59.
Is provided. Transport roller 58 and pinch roller 5
Reference numeral 9 denotes a roller disposed upstream of the skew roller 36 in the sheet conveying direction. The displacement sensor 60 is arranged in a direction facing the outer peripheral surface on the upper end side of the pinch roller 59.

In the above configuration, the pinch roller 60 is
By nipping (pinching) the sheet P between the sheet P and the transport roller 59, the sheet P is vertically displaced in accordance with the thickness of the sheet P. Therefore, the displacement sensor 60 measures the amount of displacement of the pinch roller 59 in the state where the sheet P is nipped (conveying state) with the conveying roller 58 and in the state where the sheet P is not nipped (conveying state). By reading, the thickness of the sheet P to be conveyed can be detected.

When the sheet detection sensor 55 detects the rigidity of the sheet, the configuration shown in FIG. 5C can be adopted. In such a configuration, on the upstream side of the skew roller 37 in the sheet conveying direction, the traveling direction of the sheet P is guided by the pair of guide members 61A and 61B while being bent in a substantially R shape. The outer guide member 61B is movably supported using, for example, a leaf spring or the like. In the direction in which the movable guide member 61B is displaced, the displacement sensor 6 is disposed in a direction facing the guide member 61B.
2 are arranged.

In the above configuration, the leading end of the sheet P conveyed by the conveying roller (not shown) abuts on the outer guide member 61B. At this time, if the rigidity of the sheet P is low, the traveling direction of the sheet P can be easily bent following the guide member 61B, but if the rigidity of the sheet P is high, the guide member 61
In the process of bending the traveling direction of the sheet P by the
1B is pushed outward. Thereby, the guide member 61
B is displaced in a direction approaching the displacement sensor 62, and the amount of displacement changes according to the rigidity of the sheet P. That is, when the rigidity of the sheet P is high, the displacement amount of the guide member 61B increases accordingly, and when the rigidity of the sheet P is low, the displacement amount of the guide member 61 decreases accordingly. Therefore, the displacement of the guide member 61 is
By reading at 2, the rigidity of the sheet P to be conveyed can be detected.

When the sheet detection sensor 55 detects the amount of charge on the sheet, the configuration shown in FIG. 6A can be adopted. In such a configuration, a surface electrometer 63 is provided on the upstream side of the skew roller 37 in the sheet conveying direction in a direction facing the sheet P. The surface voltmeter 63 generates an output signal corresponding to the amount of charge on the sheet P. Therefore, by reading the output signal of the surface voltmeter 63, the sheet P to be conveyed is read.
Can be detected.

When the sheet detection sensor 55 detects the water content of the sheet, the configuration shown in FIG. 6B can be adopted. In this configuration, the sheet P is temporarily stopped at a position where the sheet is temporarily stopped on the upstream side of the skew roller 37 in the sheet conveying direction, for example, at the feed rollers 20, 21, 22 (see FIG. 1) corresponding to each tray. A moisture content meter 64 is provided at the position. The moisture content meter 64 generates an output signal according to the moisture content of the sheet P by sandwiching the sheet P from above and below. Therefore, when the sheet P is temporarily stopped, the sheet P is sandwiched by the moisture content meter 64, and the output signal of the moisture content meter 64 is read in that state to detect the moisture content of the sheet P to be conveyed. It becomes possible.

When the sheet detection sensor 55 detects the temperature of the sheet, the configuration shown in FIG. 6C can be adopted. In such a configuration, the inside of the tray or the upstream side of the skew roller 37 in the sheet conveying direction is
An infrared temperature sensor 65 is provided in a direction facing the sheet P. The infrared temperature sensor 65 generates an output signal corresponding to the temperature of the sheet P. Therefore, by reading the output signal of the infrared temperature sensor 65, the temperature of the sheet P to be conveyed can be detected.

As for the moisture content and temperature of the sheet P, for example, a temperature sensor and a humidity sensor are mounted in the image forming apparatus (in particular, near the tray) in addition to using the moisture content meter 64 and the infrared sensor 65. The moisture content and temperature of the sheet P may be estimated based on temperature and humidity information obtained by these sensors.

As for the basis weight of the sheet, the detection result of the sheet paper quality by the photo sensor 57 and the displacement sensor 60
Can be comprehensively determined based on the sheet thickness detection result.

On the other hand, the skew detection sensor 56 constitutes a displacement detecting means in the present invention. The sheet misalignment state that can be detected by the skew detection sensor 56 includes state information such as lead skew, side skew, and side registration. The lead skew refers to the inclination of the leading end of the sheet with respect to a direction orthogonal to the sheet conveying direction Y, and the side skew refers to the inclination of the sheet side end with respect to a direction parallel to the sheet conveying direction Y.

When the skew detection sensor 56 detects the state of the read skew, the configuration shown in FIG. 7A can be adopted. In such a configuration,
A pair of detection sensors 66A and 66B is disposed upstream of the skew roller 37 in the sheet conveying direction Y, more specifically, slightly before the skew roller 37. Further, the pair of detection sensors 66A and 66B are arranged at predetermined intervals on an axis orthogonal to the sheet conveying direction Y. Each of the detection sensors 66A and 66B is constituted by, for example, an optical sensor having a light-emitting element and a light-receiving element, and is configured such that the front end or the rear end of the sheet P passes through each detection point (sensing position). The output signal (for example, on / off state) is switched.

In the above configuration, when the leading edge of the sheet P conveyed by the upstream conveying roller (not shown) passes through the detection points of the detection sensors 66A and 66B, the output signal of each sensor switches according to the passage timing. . At this time, the leading end of the sheet P is
When the detection points A and 66B pass at the same time, that is, when no lead skew occurs, the output signals of the respective sensors are simultaneously switched. On the other hand, when the leading edge of the sheet P does not pass through the detection points of the detection sensors 66A and 66B at the same time, that is, when a lead skew occurs, a shift occurs in the switching timing of the output signal of each sensor. Therefore, each detection sensor 66
By reading the switching timing of the output signals of A and 66B, it is possible to detect whether or not the read skew is occurring, and further, how large (skew amount) the read skew is occurring. .

When the skew detection sensor 56 detects the state of side skew, the configuration shown in FIG. 7B can be adopted. In such a configuration,
A pair of CCDs is provided upstream of the skew roller 37 in the sheet conveying direction Y, more specifically, slightly before the skew roller 37.
Sensors 67A and 67B are arranged. The pair of CCD sensors 67A and 67B are arranged at predetermined intervals on an axis parallel to the sheet conveying direction Y. Each CCD
The sensors 67A and 67B have a configuration in which the sensor output level changes when the side edge of the sheet P passes through the respective reading ranges.

In the above configuration, the side edge of the sheet P conveyed by the upstream conveying roller (not shown) is
When passing through the reading range of the D sensors 67A and 67B, the output level of each sensor changes according to the passing position. By reading the output signals of the CCD sensors 67A and 67B at a predetermined timing, one C
Since the side end position of the sheet P in the CD sensor 67A and the side end position of the sheet P in the other CCD sensor 67B can be grasped, it is determined whether or not side skew has occurred, and how much the side skew has occurred. It is possible to detect whether the error occurs at the size (skew amount).

Note that the state of the side register is CC
Detecting from the amount of deviation between the side edge position of the sheet P, which is grasped from the output signals of the D sensors 67A and 67B, and the preset reference position of the side register (the position regulated by the side reference surface 33 of the side guide 32). Is possible. Also,
The state of the side skew can be detected by using one CCD sensor (for example, only the CCD sensor 67A) and reading the sensor output signal two or more times at different timings. Further, the state of the side register can be detected with only one CCD sensor.

Subsequently, the sheet conveying system 4 based on a control command from the controller 54 (particularly, the skew correction unit 26)
Will be described with reference to the flowchart of FIG.

First, when the image formation start button (copy start button or the like) is pressed by the user, the controller 54 drives the drive motor (including the roller rotation motor 49) for driving the transport roller in step S1, thereby Start conveying the sheet. The sheet conveyed at this time is sent out from the tray selected by the user using the operation panel 23.

Next, in step S2, various kinds of information obtained by the operation panel 23, the sheet detection sensor 55, and the skew detection sensor 56 until the sheet conveyed as described above reaches the skew roller 37. Is taken in by the controller 54. The information taken in by the controller 54 includes a positional deviation state of the sheet in the sheet conveying path (a state of a lead skew, a side skew, a side registration, and the like), and sheet-related information (basis weight, paper quality, thickness) related to the sheet to be conveyed. The first side or the second
Surface, size, rigidity, charge amount, water content, temperature, etc.).

Subsequently, in step S3, the controller 54 sets various conditions (angle change conditions) relating to the angle change of the skew roller 37 based on the various information taken in step S2. These conditions include the skew roller 3
7, an initial angle and a final angle, and a time for maintaining the initial angle.

FIGS. 9A and 9B show the corners of the skew roller 37.
It is a figure showing the setting principle of various conditions concerning a degree change. This figure
9, the inclination angle θ of the skew roller 37 is changed to the initial angle.
Degree θ ₀In two steps (large angle θ₁Small angle
θ_Two) Is illustrated. By the way, the initial
Angle θ₀Is a state detected by the skew detection sensor 56.
Position deviation (eg, lead skew, side
Skew amount) is within a certain range
Value, the operation panel 23 and the sheet detection sensor
The sheet-related information (for example, the sheet
Appropriate when standard values for size, basis weight, etc.)
Is the optimum angle.

First, as shown in FIG. 9A, the positional deviation amount (lead skew, side skew, side registration) of the sheet detected by the skew detection sensor 59 is changed to a predetermined positional deviation amount (hereinafter referred to as a specified amount). ), The inclination angle θ of the skew roller 37 is increased to a large angle θ _1.
Or to increase the time to maintain the initial angle θ ₀ ,
Alternatively, the angle changing condition is set so as to realize both of them. Further, when the positional deviation amount of the sheet detected by the skew detection sensor 59 is smaller than the specified amount, the inclination angle θ of the skew roller 37 is set to a small angle θ ₂ , or the time for maintaining the initial angle θ ₀ is reduced. An angle change condition is set so as to shorten the distance or to achieve both.

On the other hand, as shown in FIG. 9B, in the sheet-related information obtained by the operation panel 23 and the sheet detection sensor 55, when the basis weight is small, when the paper quality is plain paper, when the sheet is thin, When the sheet is easily shifted to the side reference surface 33 side, for example, when the rigidity is low, when the size is small, when the charge amount is low, when the moisture content is low, or when the first surface is copied, etc. The angle changing condition is set such that the inclination angle θ of the row roller 37 is set to a small angle θ ₂ , the time for maintaining the initial angle θ ₀ is shortened, or both are realized.

In the sheet-related information obtained by the operation panel 23 and the sheet detection sensor 55, when the basis weight is large, when the paper quality is coated paper, when the sheet is thick, when the rigidity is high, and when the size is large, In the case where the sheet is hard to shift to the side reference surface 33 side, for example, when the charge amount is high, when the water content is high, or when the second surface is copied, the inclination angle θ of the skew roller 37 is set to a large angle. to theta _1, or initial angle theta lengthening the time for maintaining the ₀ or sets the angle change condition so as to achieve both. For reference, when copying the second surface, silicon oil or the like adheres to the surface of the sheet by the fixing device 16 when copying to the first surface, thereby reducing the frictional resistance between the skew roller 37 and the sheet. Therefore, the sheet is less likely to be shifted toward the side reference surface 33 side. Also,
When the sheet is coated paper, the coating process on the sheet surface reduces the frictional resistance between the skew roller 37 and the sheet, so that the sheet is less likely to move to the side reference surface 33 side.

In the examples shown in FIGS. 9A and 9B, the inclination angle θ of the skew roller 37 is set to one of the initial angle θ ₀ , the large angle θ ₁ , and the small angle θ _2. However, since the inclination angle θ of the skew roller 37 can be arbitrarily changed by controlling the driving of the angle changing motor 44, the controller 54 can further finely adjust the angle changing condition. It is possible to set.

For example, when the inclination angle θ of the skew roller 37 is set to a large angle θ ₁ or a small angle θ ₂ , how large or small the initial angle θ ₀ is to be set is determined by various values. (E.g., lead skew amount, side skew amount, lead registration amount, basis weight, paper quality, sheet thickness, sheet rigidity, sheet size, charge amount, and water content) can be finely set.
Also, in the case where the time for maintaining the inclination angle θ of the skew roller 37 at the initial angle θ ₀ is lengthened or shortened, the extent to which the length is to be increased or shortened is finely set according to various information. It is possible.

After the conditions for changing the angle of the skew roller 37 have been set in this way, in step S4, the controller 54 drives the angle changing motor 44 based on the previously set angle changing conditions (angle changing profile). Starts angle change control. As a result, the inclination angle θ of the skew roller 37 is changed according to the angle change condition.

When changing the angle, the controller 5
Reference numeral 4 changes the tilt angle θ of the skew roller 54 in a state where the sheet is kept nipped between the skew roller 54 and the pinch roller 52, that is, in a state where the sheet is skewed (conveyed). Further, by setting the angle changing condition as described above, the skew roller 5 can be moved before and after the side edge of the sheet is taken into the U-shaped portion of the side guide 32.
4 is changed so as to decrease the inclination angle θ. This allows
The skew of the sheet skewed toward the side reference surface 33 by the skew roller 54 is gradually corrected by bringing the sheet side edge into contact with the side reference surface 33, and finally, the side edge of the sheet is adjusted to the side reference surface 33. The skew is corrected along the shape of.

When the skew is corrected by the skew correction unit 26 in this manner, the position of the sheet is detected by the skew detection means 56, or the sheet-related information obtained by the operation panel 23 or the sheet detection sensor 55, or By changing the inclination angle θ of the skew roller 54 based on both information, when the sheet is nipped and skewed by the skew roller 37, for example, if the positional deviation amount of the sheet is larger than the specified amount. In such a case, the coarse adjustment of the skew correction can be quickly performed by increasing the inclination angle of the skew roller 37, increasing the time for maintaining the initial angle, or synergistically.
In addition, when the amount of positional deviation of the sheet is smaller than the specified amount, the inclination angle of the skew roller 37 is reduced, the time for maintaining the initial angle is shortened, or the side guide 32 is moved to the side guide 32 by a synergistic action thereof. Buckling due to the collision of the sheet can be effectively prevented.

Further, in the case where the sheet is not easily shifted to the side reference surface 33 side, the skew is increased by increasing the inclination angle of the skew roller 37, increasing the time for maintaining the initial angle, or synergistic action thereof. Rough adjustment of correction can be performed quickly. In the case where the sheet easily shifts to the side reference surface 33 side, the inclination angle of the skew roller 37 is reduced, the time for maintaining the initial angle is shortened, or the synergistic action of these causes the side guide 32 to move to the side guide 32. Buckling due to the collision of the sheet can be effectively prevented.

Further, in a state where the sheet is nipped by the skew roller 37, the skew correction unit 26 changes the inclination angle θ of the skew roller 37 so that the sheet is conveyed without interruption. Thereby, the sheet conveyance efficiency is increased, and the productivity of the image forming apparatus is improved.

Here, when the inclination angle θ of the skew roller 37 is changed while the sheet is nipped, a rotational force acts on the sheet at the time of the angle change, and as a result, when the angle is changed as shown in FIG. It is also concerned that the skew amount of the sheet temporarily increases. However, since the skew correction is continued by the skew roller 37 even after the angle is changed, the skew of the sheet can be surely corrected by securing a long sheet conveyance distance for the skew correction after the angle is changed. .

As shown in FIG. 11, when the inclination angle θ of the skew roller is changed, the nip pressure of the skew roller 37 with respect to the sheet is temporarily reduced, and the state (the roller nip pressure is reduced) is changed. Angle changing motor 4
By changing the inclination angle θ of the skew roller 37 by the drive of No. 4, an appropriate slip phenomenon occurs between the sheet and the skew roller 37 when the angle is changed. As a result, since the rotational force acting on the sheet when the angle is changed is extremely weakened by the slip phenomenon, it is possible to prevent a temporary increase in the skew amount due to the angle change. Therefore, it is possible to shorten the sheet conveyance distance required for the skew correction after changing the angle.

Further, as shown in FIG.
By controlling the driving of the angle changing motor 44 so that the inclination angle θ of the angle 7 gradually changes (decreases), only a slight rotational force acts on the seat when the angle is changed. As a result, it is possible to prevent the skew amount from temporarily increasing due to the angle change as described above, and to shorten the sheet conveyance distance required for the skew correction after the angle change. Further, since the inclination angle θ of the skew roller 37 during the angle change corresponds to the skew amount of the sheet, the skew correction can be performed efficiently.

In changing the inclination angle θ of the skew roller 37, the roller nip pressure may be reduced as described above, and the angle may be gradually changed. Also, as for the method of changing the angle, FIG.
In addition to the continuous change as shown in (1), the change may be made in multiple steps (stepwise) or the degree of change may be made gentle. Further, the final inclination angle θ of the skew roller 37
May be set to 0 (zero).

In the skew correction by abutting a sheet on the side reference surface 33, for example, as shown in FIG. 13, the deflecting portion 68 is located upstream of the skew roller 37 in the sheet conveying direction Y. (In the illustrated example, it is composed of two rollers, large and small).
Is turned to the opposite side (left side in the drawing) to the side reference surface 33, so that the side reference surface 33 is always contacted from the rear end side of the sheet P, and the corner of the sheet leading edge collapses (buckling). There are known techniques for preventing this. When such a technique is applied to the sheet conveying apparatus of the present invention, the turning portion 68
By arranging the detection sensors 66A and 66B for skew detection further downstream and in the vicinity of the skew roller 37, it is possible to reduce the detection error of the sheet position deviation state due to the deflecting unit 68.

Next, another embodiment of the present invention will be described. In such an embodiment, in comparison with the above-described embodiment, in particular, the configuration of a sensor for detecting a sheet misalignment state and a sheet conveying system based on the configuration (particularly,
The operation of the skew correction unit 26) is different.

First, the configuration of a sensor for detecting the state of the sheet misalignment will be described. Skew detection sensor 56
If is to detect lead skew status,
The structure illustrated in FIG. 14A can be employed. In such a configuration, the skew roller 3 is positioned so that the state of the lead skew after being nipped by the skew roller 37 can be detected.
7, a pair of detection sensors 69A and 69B are arranged on the downstream side in the sheet conveying direction Y. The pair of detection sensors 69A and 69B are the same as the pair of detection sensors 66 described above.
A and 66B are arranged at predetermined intervals on an axis perpendicular to the sheet conveying direction Y, and the sensor output signal is switched when the leading end or the trailing end of the sheet P passes each detection point. ing. Note that the principle of detecting the lead skew is the same as that in the case of using the above-described pair of detection sensors 66A and 66B, and thus the description is omitted.

On the other hand, when the skew detection sensor 56 detects the state of the side skew and the side registration, the configuration shown in FIG. 14B can be adopted.
In this configuration, one CCD is located downstream of the skew roller 37 in the sheet conveying direction Y so that the state of side skew after being nipped by the skew roller 37 can be detected.
A sensor 70A is provided, and one CCD sensor 70B is provided upstream of the skew roller 37 in the sheet conveying direction Y. These two CCD sensors 70A, 7
0B is the side reference plane 3 which is parallel to the sheet conveying direction Y and
3 are arranged at predetermined intervals on the same axis. Each of the CCD sensors 70A and 70B has a configuration in which the sensor output level changes as the side edge of the sheet P passes through the respective reading range. Note that the principle of detecting the side skew and the side registration is the same as that in the case where the pair of CCD sensors 67A and 67B described above is used, and thus the description is omitted.

Next, the operation of the sheet transport system 4 (particularly, the skew correction unit 26) based on the above sensor configuration will be described with reference to the flowchart of FIG.

First, when an image formation start button (copy start button or the like) is pressed by the user, step S11 is performed.
, The controller 54 drives the drive motor (including the roller rotation motor 49) for driving the conveyance rollers, thereby starting the conveyance of the sheet. The sheet conveyed at this time is sent out from the tray selected by the user using the operation panel 23.

Next, in step S12, the operation panel 23 and the sheet detection sensor 55 are used until the sheet conveyed as described above reaches the skew roller 37.
The controller 54 fetches the sheet-related information obtained by the above. The information taken into the controller 54 includes sheet-related information (basis weight, paper quality, thickness, first or second side, size, rigidity, charge amount, water content, temperature, etc.) related to the sheet to be conveyed. There is.

Subsequently, in step S13, the controller 54 sets various conditions (angle change conditions) for changing the angle of the skew roller 37 based on the sheet-related information taken in step S12. These conditions include an initial angle and a final angle of the skew roller 37. For the setting method of the angle change condition corresponding to the sheet related information,
This is as shown in FIG. 9B.

After the conditions for changing the angle of the skew roller 37 have been set in this way, in step S14, the controller 54 drives the angle changing motor 44 based on the previously set angle changing conditions (angle change profile). Thus, the inclination angle θ of the skew roller 37 is set to the initial angle.

Next, the controller 54 obtains the position deviation state of the sheet (the state of the lead skew, side skew, side registration, etc.) detected by the sheet detection sensor 56 (step S15). In the present embodiment, the skew roller 37 set at the initial angle as described above is used.
The skew of the sheet, which has been substantially skew-corrected by the skew toward the side reference surface 33, is detected.

Subsequently, the controller 54 sets a time period for maintaining the inclination angle θ of the skew roller 37 at the initial angle based on the previously obtained positional deviation state of the sheet (step S16). As a specific setting method, for example, when the positional deviation amount of the sheet detected by the skew detection sensor 56 is larger than a preset allowable amount, the time for maintaining the initial angle increases according to the difference. When the amount of displacement is smaller than the allowable amount, the time for maintaining the initial angle is set to zero.

Thereafter, it is repeatedly determined whether or not the time set in the previous step S16 has elapsed (step S1).
7) When the set time has elapsed, the angle change control is started (step S18). Regarding how to change the angle, a method similar to that of the above embodiment can be adopted.

As described above, the inclination angle θ of the skew roller 37 is set to the initial angle based on the sheet-related information to be conveyed, and the skew roller 37 is inclined by the skew roller 37 toward the side reference surface 33 under the set conditions. The skew detection sensor 56 detects the misalignment state of the sheet that has been executed and the skew of which has been substantially corrected, and adjusts the start timing of the angle change control based on the detection result, thereby obtaining an effect equivalent to that of the previous embodiment. be able to.

Prior to setting the angle change condition in step S13, the position shift state of the sheet before reaching the skew roller 37 is determined by the skew detection sensor 56 (66A, 66B) as in the previous embodiment. And 67
A, 67B, etc.), and the angle change condition may be set based on the obtained positional deviation state of the sheet and the sheet-related information to be conveyed.

In the above embodiment, step S
After the angle change control is started in step 4, the skew detection sensors 56 (69A, 69B and 70)
A, 70B, etc.), and the angle change condition may be appropriately corrected based on the obtained positional deviation state of the sheet.

[0095]

As described above, according to the sheet conveying apparatus of the present invention, the positional deviation (such as skew) of the sheet is corrected based on the side reference surface of the side guide without abutting the leading end of the sheet. Therefore, even if the perpendicularity of the sheet is misaligned, the position deviation of the sheet can be properly corrected, and at least one of the state of the position deviation of the sheet in the sheet conveyance path and the sheet information related to the sheet to be conveyed is provided. Since the inclination angle of the sheet skew feeding means is changed under conditions suitable for the information, it is possible to always appropriately correct the positional deviation of the sheet without causing buckling or insufficient correction of the sheet.

Further, according to the sheet conveying apparatus of the present invention, since the inclination angle of the sheet skew means is changed while the sheet is nipped by the sheet skew means, the sheet conveyance efficiency is improved. . Further, in changing the inclination angle of the sheet skew means, the angle is changed by gradually changing the inclination angle of the sheet skew means, or by changing the angle while the nip pressure of the sheet skew means with respect to the sheet is lowered. It is possible to effectively prevent a temporary increase in the skew amount due to the change.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating an overall configuration of a full-color image forming apparatus according to the present invention.

FIG. 2 is a schematic plan view illustrating a configuration of a skew correction unit in a sheet conveyance system.

FIG. 3 is a schematic side view illustrating a configuration of a skew correction unit in a sheet conveyance system.

FIG. 4 is a control block diagram of a sheet conveying system.

FIG. 5 is a diagram (part 1) illustrating a specific configuration example of a sheet detection sensor.

FIG. 6 is a diagram (part 2) illustrating a specific configuration example of the sheet detection sensor.

FIG. 7 is a diagram illustrating a specific configuration example of a skew detection sensor.

FIG. 8 is a flowchart illustrating an operation procedure of a sheet conveyance system (skew correction unit).

FIG. 9 is a diagram showing a principle of setting an angle changing condition.

FIG. 10 is a diagram illustrating a change in a skew amount when a tilt angle of a skew roller is changed.

FIG. 11 is a diagram illustrating a change in the skew amount when the inclination angle of the skew roller is changed with the roller nip pressure lowered.

FIG. 12 is a diagram illustrating a change in the skew amount when the inclination angle of the skew roller is gradually changed.

FIG. 13 is a plan view showing a sensor arrangement in a case where a deflection unit is provided.

FIG. 14 is a diagram illustrating an arrangement state of a skew detection sensor according to another embodiment of the present invention.

FIG. 15 is a flowchart illustrating an operation procedure of a sheet conveying system according to another embodiment of the present invention.

[Description of Signs] 4 ... Sheet conveying system, 26 ... Skew correction unit, 32 ... Side guide, 33 ... Side reference surface, 36 ... Base, 37 ... Skew roller, 38 ... Rotating shaft, 39 ... Link arm, 40
... Link guide, 41 ... engagement pin, 42 ... long hole, 43 ...
Rack gear, 44: Angle changing motor, 45: Pinion gear, 49: Roller rotating motor, 54: Controller, 55: Sheet detection sensor, 56: Skew detection sensor

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Shinji Hoizumi 2274 Hongo, Ebina-shi, Kanagawa Fuji Xerox Co., Ltd. 3F048 AA01 AB01 BA05 BA20 BB02 CC02 CC03 CC05 DA06 DA07 DB03 DB06 DB12 DC14 EB22 EB24 EB34 3F102 AA01 AB01 BA02 BB04 CA05 CB06 DA14 EA06 EC01 EC04 EC11 FA01

Claims (4)

[Claims] 1. A side guide having a side reference surface arranged at one end of a sheet conveying path through which a sheet is conveyed, in parallel with the sheet conveying direction, and arranged at a predetermined inclination angle with respect to the sheet conveying direction. Sheet skew means for skewing the sheet toward the side reference surface while nipping the sheet in the sheet conveyance path; and angle changing means for changing an inclination angle of the sheet skew means with respect to the sheet conveyance direction. And, among the sheet-related information relating to the position of the sheet in the sheet conveyance path and the sheet to be conveyed,
Control means for controlling driving of the angle changing means based on at least one of the information. 2. The apparatus according to claim 1, wherein the control unit changes the inclination angle of the sheet skew feeding unit by driving the angle changing unit while the sheet is nipped by the sheet skew feeding unit. Item 2. The sheet conveying device according to Item 1. 3. The angle changing means is configured to be capable of arbitrarily changing the inclination angle of the sheet skew means. The control means is configured to control the angle such that the inclination angle of the sheet skew means changes gradually. 3. The sheet conveying device according to claim 2, wherein the driving of the changing unit is controlled. 4. The apparatus according to claim 1, wherein the control means changes the inclination angle of the sheet skew feeding means by driving the angle changing means while the nip pressure of the sheet skew feeding means with respect to the sheet is lowered. The sheet conveying device according to claim 2.