JP2023041272A - Sheet conveyance device and image formation apparatus - Google Patents

Abstract

To provide a sheet conveyance device which can prevent skew correction of a resist roller pair from being performed depending on a use state of a user, and an image formation apparatus having the same.SOLUTION: A sheet conveyance device (200) in which a plurality of resist roller pairs 233-233 (2331, 2332) are provided at an interval in the conveyance direction H in a sheet conveyance path 231 has: a non-resist skew correction mode MDN which does not perform skew correction on all the plurality of resist roller pairs 233-233 (2331, 2332); and resist skew correction modes MD (MD1, MD2) which perform skew correction on one or two or more resist roller pairs (2331 or 2332) of the plurality of resist roller pairs 233-233 (2331, 2332), and performs the non-resist skew correction mode MDN and the resist skew correction modes MD (MD1, MD2) according to the setting mode set by a user.SELECTED DRAWING: Figure 7B

Description

The present invention relates to a sheet conveying device and an image forming apparatus including the same, such as a copier, a multifunction machine, a printer, and a facsimile machine.

2. Description of the Related Art As a sheet conveying device, there is a sheet conveying device in which a plurality of pairs of registration rollers are provided at intervals for performing skew correction of a sheet conveyed on a sheet conveying path (for example, see Patent Documents 1 and 2).

Specifically, in Patent Document 1, when the skew amount is equal to or less than a predetermined value, either one of the first conveying means (first registration roller pair) and the second conveying means (second registration roller pair) is selected. A configuration for correcting the skew of a sheet is described.

Further, Japanese Patent Application Laid-Open No. 2002-200000 describes a first control mode in which skew correction is performed on a sheet by a first roller pair (first registration roller pair), or a first control mode in which skew correction is performed on a sheet by a first roller pair (first registration roller pair). After that, a configuration is described in which a second control mode is selected in which skew correction is performed by a second roller pair (second registration roller pair).

JP 2015-54747 A JP 2009-107782 A

By the way, depending on the usage situation, the user may not want to perform the skew correction of the registration roller pair, for example, in a quiet environment where the rotation start sound (clutch sound) of the registration roller pair makes the user uncomfortable. .

Regarding this point, the configurations described in Patent Documents 1 and 2 are not configured to prevent the skew correction of the pair of registration rollers depending on the user's usage conditions.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a sheet conveying apparatus and an image forming apparatus having the sheet conveying apparatus that can prevent the skew correction of the pair of registration rollers depending on the usage conditions of the user.

In order to solve the above-described problems, a sheet conveying apparatus according to the present invention provides a sheet conveying apparatus in which a plurality of pairs of registration rollers for performing skew correction of the sheet conveyed on a sheet conveying path are provided at intervals. a non-registration skew correction mode in which the skew correction is not performed for all of the plurality of registration roller pairs; A non-registration skew correction mode or a registration skew correction mode is performed according to a setting mode set by a user. According to another aspect of the present invention, there is provided an image forming apparatus including the sheet conveying device according to the present invention.

According to the present invention, it is possible to prevent the skew correction of the pair of registration rollers depending on the user's usage.

1 is a cross-sectional view showing a schematic configuration of an image forming apparatus provided with a document feeder according to an exemplary embodiment; FIG. 1 is a perspective view showing a document feeder according to this embodiment; FIG. 3 is an enlarged cross-sectional view showing an enlarged document conveying portion of the document feeder; FIG. 4 is a schematic block diagram showing a control configuration for controlling the operation of the document feeder; FIG. FIG. 2 is a schematic side view of a document conveying portion of the document feeder; FIG. 4 is a plan view showing the document conveying section of the document feeder in chronological order, showing a state in which a minimum size document is pushed into the first pair of registration rollers whose rotation is stopped; FIG. 10 is a plan view showing the document conveying unit in the document feeder in chronological order, showing a state in which a document having a size larger than the minimum size is pushed into the first pair of registration rollers whose rotation is stopped; FIG. 10 is a plan view showing the document conveying section in the document feeder in chronological order, showing a state in which a document larger than the minimum size is pushed into the second pair of registration rollers whose rotation is stopped; FIG. 4 is a plan view showing an example of a first selection screen of the display unit; 4 is a chart showing an example of a combination of a non-registration skew correction mode, a first registration skew correction mode, and a second registration skew correction mode, which are performed according to setting modes; FIG. 9 is a plan view showing a first setting screen for setting any one of a non-registration skew correction mode, a first registration skew correction mode, and a second registration skew correction mode for each setting mode; It is a figure which shows the initialization state of normal mode. 8B is a plan view showing a setting example in which the normal mode shown in FIG. 8A is changed from the first registration skew correction mode of the plain paper mode to the second registration skew correction mode; FIG. FIG. 11 is a plan view showing an example of a second selection screen of the display unit; FIG. 10 is a chart showing an example of a combination of a non-registration skew correction mode and a first registration skew correction mode performed according to a setting mode, together with a normal mode; FIG. FIG. 10 is a plan view showing a second setting screen for setting a non-registration skew correction mode or a first registration skew correction mode for each setting mode, and showing an initial setting state of the silent priority mode; 10B is a plan view showing a setting example in which the non-registration skew correction mode of the thin paper mode is changed to the first registration skew correction mode in the silent priority mode shown in FIG. 10A; FIG. FIG. 11 is a plan view showing an example of a third selection screen of the display unit; 4 is a table showing an example of a combination of a first registration skew correction mode and a second registration skew correction mode performed according to a setting mode, together with a normal mode and a quietness priority mode; FIG. 10 is a plan view showing a third setting screen for setting a first registration skew correction mode or a second registration skew correction mode for each setting mode, and showing an initial setting state of the image quality priority mode; 12B is a plan view showing a setting example in which the image quality priority mode shown in FIG. 12A is changed from the second registration skew correction mode of the thick paper mode to the first registration skew correction mode; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments according to the present invention will be described below with reference to the drawings. In the following description, the same parts are given the same reference numerals. Their names and functions are also the same. Therefore, a detailed description thereof will not be repeated.

[Image forming apparatus]
FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus 100 including a document feeder 200 according to this embodiment. In FIG. 1, X indicates the horizontal direction (horizontal direction), Y indicates the depth direction (front-rear direction), and Z indicates the vertical direction (height direction).

The image forming apparatus 100 is a multifunction machine having a copy function, a scanner function, a facsimile function, and a printer function, and transmits an image of a document G (an example of a sheet) read by the image reading device 102 to the outside. Further, the image forming apparatus 100 forms an image of the document G read by the image reading apparatus 102 or an image received from the outside in color or monochrome on paper (recording material). Note that the image forming apparatus 100 may form a monochrome image.

The image reading device 102 includes a document feeding device 200 (an example of a sheet feeding device). The document feeding device 200 is provided above the image reading section 130 and supported so as to be openable and closable with respect to the image reading section 130 . The document feeder 200 sequentially conveys one or more originals G one by one. The image reading device 102 reads a document G conveyed one by one out of one or a plurality of documents by the document feeding device 200 . The image reading device 102 includes a document table 130a (original table) on which a document G is placed, and a placed document reading function for reading the document G placed on the document table 130a. In the image forming apparatus 100, when the document feeder 200 is opened, the document table 130a above the image reading section 130 is opened so that the document G can be manually placed. The document feeder 200 also includes a document placement tray 210 on which the document G is placed, and a document ejection tray 250 on which the document G ejected to the outside is stacked. The image reading device 102 has a conveyed document reading function of reading the document G conveyed by the document feeding device 200 . The document feeder 200 conveys the document G placed on the document placement tray 210 onto the document reading section 130 b of the image reading section 130 . The image reading unit 130 scans the document G placed on the document table 130a by scanning the scanning optical system 130c, or reads the document G conveyed by the document feeder 200 to generate image data.

The image forming apparatus 100 includes an image forming section 110 . The image forming unit 110 includes an optical scanning device 1, a developing device 2, a photosensitive drum 3, a drum cleaning device 4, a charger 5, an intermediate transfer belt 7, a fixing device 12, a paper transport path S, a paper feed cassette 18, and a paper discharge. A tray 141 (internal discharge tray) is provided.

The image forming unit 110 forms an image corresponding to a color image using black (K), cyan (C), magenta (M), and yellow (Y), or a monochrome image using a single color (for example, black). data is handled. The image transfer unit 50 of the image forming apparatus 100 is provided with four developing devices 2, four photosensitive drums 3, four drum cleaning devices 4, and four chargers 5 for forming four types of toner images. Corresponding to cyan, magenta and yellow, four image stations Pa, Pb, Pc and Pd are configured.

The optical scanning device 1 exposes the surface of the photosensitive drum 3 to form an electrostatic latent image. The developing device 2 develops the electrostatic latent image on the surface of the photoreceptor drum 3 to form a toner image on the surface of the photoreceptor drum 3 . The drum cleaning device 4 removes and collects residual toner on the surface of the photosensitive drum 3 . The charger 5 uniformly charges the surface of the photosensitive drum 3 to a predetermined potential. A toner image of each color is formed on the surface of each photosensitive drum 3 by the series of operations described above.

An intermediate transfer roller 6 is arranged above the photosensitive drum 3 with an intermediate transfer belt 7 interposed therebetween. The intermediate transfer belt 7 is stretched around a transfer driving roller 7a and a transfer driven roller 7b, and circulates in the direction of arrow C. As shown in FIG. In the image forming apparatus 100 , residual toner is removed and collected by the belt cleaning device 9 , and the toner images of each color formed on the surface of each photoreceptor drum 3 are sequentially transferred and superimposed on the surface of the intermediate transfer belt 7 . A color toner image is formed.

A nip area is formed between the transfer roller 11a of the secondary transfer portion 11 and the intermediate transfer belt 7, and the sheet conveyed through the sheet conveying path S is nipped in the nip area and conveyed. When the paper passes through the nip area, the toner image on the surface of the intermediate transfer belt 7 is transferred to the paper, and the paper is conveyed to the fixing device 12 .

The fixing device 12 includes a fixing roller 12a and a pressure roller 12b that rotate while sandwiching the paper. The fixing device 12 sandwiches the paper having the toner image transferred between the fixing roller 12a and the pressure roller 12b, heats and presses the paper, and fixes the toner image to the paper.

The paper feed cassette 18 is a cassette for storing paper used for image formation, and is provided below the optical scanning device 1 . The paper is pulled out from the paper feed cassette 18 by the pickup roller 16 (pickup roller) and conveyed to the paper conveying path S. As shown in FIG. The paper transported to the paper transport path S passes through the secondary transfer section 11 and the fixing device 12 , is transported to the discharge roller pair 17 , and is discharged to the paper discharge tray 141 . A transport roller pair 13 , a registration roller pair 14 and a discharge roller pair 17 are arranged in the paper transport path S. As shown in FIG. The transport roller pair 13 promotes transport of the paper. The registration roller pair 14 temporarily stops the paper and aligns the leading edge of the paper. The registration roller pair 14 conveys the stopped sheet in synchronism with the timing of the toner image on the intermediate transfer belt 7 . The toner image on the intermediate transfer belt 7 is transferred onto the paper in the nip area between the intermediate transfer belt 7 and the transfer roller 11a. In FIG. 1, one paper feed cassette 18 is provided, but the configuration is not limited to this, and a configuration in which a plurality of paper feed cassettes 18 are provided may be employed.

Further, the image forming apparatus 100 conveys the paper from the discharge roller pair 17 to the paper reversing path Sr in the reverse direction when forming an image on the back surface as well as the front surface of the paper. The image forming apparatus 100 turns over the sheet conveyed in the opposite direction, and guides the sheet to the registration roller pair 14 again. Also, the image forming apparatus 100 forms an image on the back side of the sheet guided to the registration roller pair 14 in the same manner as the front side, and conveys the sheet to the sheet discharge tray 141 .

The image reading unit 130 is provided on the upper surface of the image forming apparatus main body 101 . A document feeder 200 is attached on the image reading section 130 .

[Document feeder]
FIG. 2 is a perspective view showing the document feeder 200 according to this embodiment. FIG. 3 is an enlarged cross-sectional view showing an enlarged portion of the document conveying section 230 in the document feeder 200. As shown in FIG. FIG. 4 is a schematic block diagram showing a control configuration for controlling the operation of document feeder 200. As shown in FIG. FIG. 5 is a schematic side view of the document conveying section 230 in the document feeder 200. As shown in FIG. 6A to 6C are plan views showing the document transport section 230 in the document feeder 200 in chronological order. FIG. 6A shows a state in which a document G of the minimum size (business card vertical size in this example) is pushed into the first registration roller pair 2331 whose rotation is stopped. 6B and 6C, respectively, a document G having a size larger than the minimum size (A4 horizontal size in the illustrated example) is pushed into the first registration roller pair 2331 whose rotation is stopped and the second registration roller pair 2332 whose rotation is stopped. This indicates that the

The document feeder 200 includes a document tray 210, a document supply section 220, a document transport section 230, a document discharge section 240, a document discharge tray 250, a control section 260, a transport drive section 270, and a transport drive. A transmission mechanism 280 is provided. A document G is placed on the document placing tray 210 . The document supply section 220 supplies the document G placed on the document placement tray 210 to the document transport section 230 one by one. The document conveying section 230 conveys the document G supplied by the document supplying section 220 with reference to the center in the width direction W perpendicular to the conveying direction H. As shown in FIG. The document discharge section 240 discharges the document G transported by the document transport section 230 . The document discharge section 240 includes a discharge roller pair 241 . The document discharge tray 250 stacks the documents G discharged by the document discharge section 240 . In the document feeder 200, the document placement tray 210 and the document discharge tray 250 are arranged so as to overlap each other in the vertical direction.

Specifically, the document conveying section 230 includes a pair of conveying guides 232 (232a, 232b) forming a sheet conveying path 231, and a plurality of (two in this example) pairs of registration rollers 233 to 233 (2331, 2332). , a pre-reading conveying roller pair 234 , a post-reading conveying roller pair 235 , and a pre-discharging conveying roller pair 236 . A plurality of registration roller pairs 233 to 233 (2331, 2332), a pre-reading transport roller pair 234, a post-reading transport roller pair 235, and a pre-discharge transport roller pair 236 are arranged in order along the sheet transport path 231. .

The document supply unit 220 includes a pickup roller 221 (pickup roller), a supply roller 222 (paper feed roller), a separation member [separation roller or separation pad (separation roller 223 in this example)], and a supply drive transmission mechanism 224. and

The pick-up roller 221 picks up the top document G among the documents G stacked on the document tray 210 . The supply roller 222 and the separation roller 223 separate and convey the document G drawn by the drawing roller 221 one by one. The supply roller 222 conveys the document G drawn by the pickup roller 221 one by one toward the pair of conveyance guides 232 together with the separation roller 223 . The separation roller 223 is arranged to face the supply roller 222 . The separation roller 223 regulates the conveyance of the second and subsequent originals G stacked on the original tray 210 in the conveying direction H, and prevents the lowermost (last original G) from being conveyed. Transport in direction H can be allowed. The supply drive transmission mechanism 224 is composed of a gear train or pulley and a belt, and transmits the rotational drive force sent to the supply roller 222 to the pickup roller 221 . The drawing roller 221, the supply roller 222, and the separation roller 223 are positioned in the central portion in the width direction W (see FIGS. 6A to 6C). As a result, the document G can be brought in and supplied on the basis of the center in the width direction W. As shown in FIG. The document supply unit 220 is conventionally known, and the description of other detailed configurations is omitted.

A pair of transport guides 232 form a sheet transport path 231 between the document supply section 220 and the document discharge section 240 . The sheet conveying path 231 is formed so as to convey the document G in a substantially horizontal direction, make a U-turn downward, and then convey it obliquely upward. The sheet conveying path 231 has a reading position R (see FIGS. 3 and 5) for reading the image of the document G at the bottom.

The plurality of registration roller pairs 233 to 233 consist of a first registration roller pair 2331 and a second registration roller pair 2332 in this example. A first registration roller pair 2331 , a second registration roller pair 2332 , a pre-reading conveying roller pair 234 , a post-reading conveying roller pair 235 , and a pre-discharging conveying roller pair 236 are arranged along the sheet conveying path 231 from the supply roller 222 in the conveying direction. They are provided in order toward the downstream side of H. A reading position R is provided between the pre-reading conveying roller pair 234 and the post-reading conveying roller pair 235 . The pre-discharge transport roller pair 236 is provided closest to the discharge roller pair 241 on the upstream side in the transport direction H from the discharge roller pair 241 .

The first registration roller pair 2331, the second registration roller pair 2332, the pre-reading conveying roller pair 234, the post-reading conveying roller pair 235, and the pre-discharging conveying roller pair 236 are composed of driving rollers 2331a, 2332a, 234a to 236a and driven rollers 2331b, 2331b and 2331b. 2332b, 234b to 236b. The discharge roller pair 241 is composed of a driving roller 241a and a driven roller 241b.

The transport drive unit 270 (brushless DC motor) (see FIG. 4) is electrically connected to the output system of the control unit 260 . Thereby, the control section 260 can drive the transport driving section 270 at a predetermined timing. The transport drive transmission mechanism 280 transmits the rotational driving force from the transport drive unit 270 to the supply roller 222 and the drive rollers 2331a, 2332a, 234a to 236a, 241a.

The transport drive transmission mechanism 280 has a first registration clutch 281 and a second registration clutch 282 . The first registration clutch 281 and the second registration clutch 282 are provided on the drive rollers 2331a and 2332a, respectively, and are configured to selectively switch between disconnection and connection of the rotational driving force to the drive rollers 2331a and 2332a. The driving rollers 2331a and 2332a are rotationally driven by turning on the first registration clutch 281 and the second registration clutch 282, respectively. The first resist clutch 281 and the second resist clutch 282 are electrically connected to the output system of the controller 260 . Thereby, the control section 260 can turn on and off the first resist clutch 281 and the second resist clutch 282 at a predetermined timing.

The driven rollers 2331b, 2332b, 234b-236b, 241b are driven to rotate by the drive rollers 2331a, 2332a, 234a-236a, 241a. Here, the drive rollers 2331a, 2332a, 234a to 236a, and 241a all have the same diameter (specifically, 18 mm). The driven rollers 2331b, 2332b, 236b, and 241b all have the same diameter (specifically, 18 mm). The diameters of the driven rollers 234b and 235b are all the same, and are smaller than the diameters of the other driven rollers 2331b, 2332b and 236b (10 mm).

The first registration roller pair 2331, the second registration roller pair 2332, the pre-reading conveying roller pair 234, the post-reading conveying roller pair 235, the pre-discharging conveying roller pair 236, and the discharging roller pair 241 are arranged as shown in FIGS. 6A to 6C. , roller portions 2331c to 2331c, 2332c to 2332c, 234c to 234c, 235c to 235c, 236c to 236c, and 241c to 241c at a plurality of locations including a central roller portion. Note that, as shown in FIG. 6A, the minimum size document G (vertical size business card in this example) has a first registration roller pair 2331, a second registration roller pair 2332, a pre-reading conveying roller pair 234, and a post-reading conveying roller. In the pair 235 and the pre-discharge conveying roller pair 236, the paper is nipped and conveyed by roller portions 2331c, 2332c, 234c, 235c, and 236c at one central portion, and in the pair of discharging rollers 241, two roller portions 241c and 241c in the central portion. is pinched and transported.

<Control section>
As shown in FIG. 4, the control unit 260 performs skew correction control for correcting the skew of the document G (skew feeding). The control unit 260 includes a processing unit 261 including a computer such as a CPU (Central Processing Unit), a storage unit 262 including a non-volatile memory such as a ROM (Read Only Memory) and a volatile memory such as a RAM (Random Access Memory). ,have. Note that the control unit 260 may be provided in the image forming apparatus 100 .

In the control unit 260, the control program pre-stored in the ROM of the storage unit 262 is called by the processing unit 261 and loaded onto the RAM of the storage unit 262 to control the operation of various components.

The image forming apparatus 100 also includes an operation display section 150 . The operation display unit 150 includes a reception unit 151 (a touch panel in this example) and a display unit 152 (a display panel in this example). The reception unit 151 is electrically connected to the input system of the control unit 260 . The reception unit 151 receives input operation information by the user. The display section 152 is electrically connected to the output system of the control section 260 . The display unit 152 displays various information on the display screen based on the display data. The reception unit 151 is provided on the display unit 152 . In the operation display unit 150 , the reception unit 151 receives touch operation information by the user on various software keys displayed on the display unit 152 .

The document feeder 200 includes a first conveyance detection section 291 , a second conveyance detection section 292 and a third conveyance detection section 293 .

The first conveyance detection unit 291, the second conveyance detection unit 292, and the third conveyance detection unit 293 are all photocouplers (conveyance timing sensors) that emit light and receive reflected light from the document G. be.

<First Conveyance Detector>
The first transport detection unit 291 is provided upstream of the first registration roller pair 2331 in the transport direction H by a predetermined first distance d1 (see FIG. 5). The first conveyance detection unit 291 detects whether or not the document G has passed upstream of the first pair of registration rollers 2331 by the first distance d1. The first conveyance detection section 291 is electrically connected to the input system of the control section 260 .

(When performing skew correction with the first pair of registration rollers)
The control unit 260 transports the document G by the supply roller 222, hits the document G against the nip portion of the first registration roller pair 2331 which is not rotating from the timing when the document G is detected by the first transport detection unit 291, and further feeds the document G. The document G is conveyed by a predetermined first pressing amount (predetermined first pressing time) from the timing when the document G hits. As a result, the leading edge G<b>1 of the document G can be reliably aligned with the nip portion of the first registration roller pair 2331 .

(When skew correction is not performed with the first pair of registration rollers)
The control unit 260 conveys the document G sent from the supply roller 222 to the second registration roller pair 2332 by the first registration roller pair 2331 while rotating the first registration roller pair 2331 .

<Second Conveyance Detector>
The second transport detection unit 292 is provided upstream of the second registration roller pair 2332 in the transport direction H by a predetermined second distance d2 (see FIG. 5). The second conveyance detection unit 292 detects whether or not the document G has passed upstream of the second pair of registration rollers 2332 by the second distance d2. The second conveyance detection section 292 is electrically connected to the input system of the control section 260 .

(When performing skew correction with the second pair of registration rollers 2332)
The control unit 260 conveys the document G by the first pair of registration rollers 2331, and from the timing when the second conveyance detection unit 292 detects the document G, the control unit 260 pushes the document G into the nip portion of the second pair of registration rollers 2332 that are not rotating. The document G is conveyed by a predetermined second pressing amount (predetermined second pressing time) from the timing when the document G is hit. As a result, the leading edge G<b>1 of the document G can be reliably aligned with the nip portion of the second pair of registration rollers 2332 .

(When skew correction is not performed by the second pair of registration rollers 2332)
With the second registration roller pair 2332 rotated, the control unit 260 conveys the document G sent from the supply roller 222 toward the pre-reading conveyance roller pair 234 by the second registration roller pair 2332 as it is.

-When Skew Correction is Performed with the First Registration Roller Pair and the Second Registration Roller Pair-
When the first registration roller pair 2331 performs skew correction, the control unit 260 controls the first registration roller pair 2331 to rotate at a predetermined rotation start timing in a state in which the document G is pushed into the nip portion of the first registration roller pair 2331 that is not rotating. The rotation of the registration roller pair 2331 is started. Further, when the skew correction is performed by the second pair of registration rollers 2332, the control unit 260 sets the predetermined rotation start timing in a state in which the document G is pushed into the nip portion of the second pair of registration rollers 2332 whose rotation is stopped. , the rotation of the second registration roller pair 2332 is started.

-When Skew Correction is Performed Only with the First Registration Roller Pair-
When skew correction is performed only by the first pair of registration rollers 2331, the controller 260 corrects the skew at a predetermined rotation start timing in a state in which the document G is pushed into the nip portion of the first pair of registration rollers 2331 that are not rotating. The rotation of the first registration roller pair 2331 is started. Further, the control unit 260 causes the document G to pass through the rotating second registration roller pair 2332 as it is.

-When Skew Correction is Performed Only with the Second Registration Roller Pair-
The controller 260 causes the document G to pass through the rotating first registration roller pair 2331 as it is. Further, the control unit 260 starts rotation of the second registration roller pair 2332 at a predetermined rotation start timing in a state where the document G is pushed into the nip portion of the second registration roller pair 2332 whose rotation is stopped.

-When Skew Correction is not Performed by the First Registration Roller Pair and the Second Registration Roller Pair-
The controller 260 causes the document G to pass through the rotating first registration roller pair 2331 and the rotating second registration roller pair 2332 as they are.

<Third Conveyance Detector>
The third transport detection unit 293 is provided upstream of the pre-reading transport roller pair 234 in the transport direction H by a predetermined third distance d3 (see FIG. 5). The third conveyance detection unit 293 detects whether or not the document G has passed upstream of the pre-reading conveyance roller pair 234 by a third distance d3. The third transport detection section 293 is electrically connected to the input system of the control section 260 .

The controller 260 rotates the pre-reading conveying roller pair 234, the post-reading conveying roller pair 235, the pre-discharging conveying roller pair 236, and the discharging roller pair 241, and the document G sent from the second registration roller pair 2332. passes the reading position R by the pre-reading conveying roller pair 234 and is conveyed toward the document discharge tray 250 by the post-reading conveying roller pair 235 , the pre-discharge conveying roller pair 236 and the discharge roller pair 241 .

[About this embodiment]
In this embodiment, the sheet conveying device (document feeding device 200) includes a plurality of registration roller pairs 233 to 233 (2331, 2332) are provided at intervals in the transport direction H in which the sheet (G) is transported.

The control unit 260 has a non-registration skew correction mode MDN and a registration skew correction mode MD (MD1, MD2). In the non-registration skew correction mode MDN, skew correction is not performed on all of the plurality of registration roller pairs 233 to 233 (2331, 2332). In the registration skew correction mode MD (MD1, MD2), one or two or more registration roller pairs (2331 and/or 2332) out of the plurality of registration roller pairs 233 to 233 (2331, 2332) perform skew feeding. Make corrections.

The control unit 260 performs the non-registration skew correction mode MDN or the registration skew correction mode MD (MD1, MD2) according to the setting mode set by the user.

According to this embodiment, the non-registration skew correction mode MDN or the registration skew correction mode MD (MD1, MD2) is performed according to the setting mode set by the user. The registration roller pairs 233 to 233 (2331, 2332) are configured not to perform any skew correction. In an uncomfortably quiet environment, skew correction for all of the registration roller pairs 233 to 233 (2331, 2332) can be disabled.

Here, the usage conditions include the ambient environment (for example, the setting environment such as a silent environment in which the rotation start sound of the registration roller pair 233 annoys the user), and the type of sheet (G) (for example, plain paper, cardboard, etc.). The thickness of the sheet (G) such as thin paper, the size of the sheet (G) such as A4 size, B5 size, and business card size], image forming conditions (for example, image quality such as high resolution), and the like can be mentioned. Plain paper means reference paper (standard paper) having a predetermined reference thickness range (predetermined reference basis weight range, eg, 50 g/m ² to 100 g/m ² ). Thick paper means paper having a thickness (grammage) greater than a reference thickness (the upper limit of the reference grammage, eg, 100 g/m ² ). Thin paper means paper having a thickness (grammage) smaller than a standard thickness (the lower limit of the standard grammage, eg, 50 g/m ² ).

(normal mode)
FIG. 7A is a plan view showing an example of the first selection screen S1 of the display section 152. FIG. FIG. 7B is a table showing an example of combinations of the non-registration skew correction mode MDN, the first registration skew correction mode MD1, and the second registration skew correction mode MD2, which are performed according to the setting mode.

In this example, the setting modes are plain paper mode, thick paper mode, thin paper mode, mixed loading mode, business card mode, and skew correction setting mode as reading modes. Here, the plain paper mode, thick paper mode, thin paper mode, and business card mode are modes for conveying plain paper, thick paper, and thin paper, respectively. The mixed loading mode is a mode for conveying a plurality of originals G of different sizes in one job.

The registration skew correction mode MD has a first registration skew correction mode MD1 and a second registration skew correction mode MD2.

As shown in FIG. 7A, the first selection screen S1 of the display unit 152 displays plain paper mode, thick paper mode, thin paper mode, mixed mode, business card mode, and skew correction settings in the normal mode (default mode). Any one of the modes is displayed so as to be selectable by the user. FIG. 7A shows a state in which the plain paper mode is selected.

In the storage unit 262, as shown in FIG. 7B, in the normal mode, for each setting mode (in this example, plain paper mode, thick paper mode, thin paper mode, mixed paper mode, business card mode, and skew correction setting mode), A registration skew correction mode MDN, a first registration skew correction mode MD1 or a second registration skew correction mode MD2 is stored in advance.

In this example, in the "normal mode" storage area of the storage unit 262, the first registration skew correction mode MD1 is set in advance for the plain paper mode and the thick paper mode. The second registration skew correction mode MD2 is set in advance in the thin paper mode, the mixed loading mode, and the business card mode. Further, in the skew correction setting mode, a non-registration skew correction mode MDN is set in advance.

When accepting unit 151 accepts an operation to select one of the setting modes, control unit 260 executes a mode corresponding to the accepted setting mode. In this example, the plain paper mode is set. For example, when the reception unit 151 receives a selection operation of the skew correction setting mode, the control unit 260 selects a non-registration skew image according to the received skew correction setting mode. Execute line correction mode MDN.

<First embodiment>
In the first registration skew correction mode MD1, one or more (one in this example) registration roller pair 233 (2331 or 2332) out of the plurality of registration roller pairs 233 to 233 (2331, 2332) to correct the skew. In the second registration skew correction mode MD2, skew correction is performed by all of the plurality of registration roller pairs 233 to 233 (2331, 2332).

The control unit 260 performs any one of the non-registration skew correction mode MDN, the first registration skew correction mode MD1, and the second registration skew correction mode MD2 according to the setting mode (broken line in FIG. 7B). See frame α1).

By doing so, it is possible to prevent skew correction from being performed on all of the multiple (two in this example) registration roller pairs 233 to 233 (2331, 2332) depending on the user's usage conditions. For example, under a quiet environment where the rotation start sound of the registration roller pair 233 makes the user uncomfortable, all of the plurality (two in this example) of the registration roller pairs 233 to 233 (2331, 2332) can be set so as not to perform the skew correction.

In the present embodiment, the sheet conveying apparatus (200) is capable of conveying sheets (G) of a plurality of types [in this example, a plurality of thicknesses (basis weights) and/or a plurality of sizes]. It is

By the way, the smaller the thickness (basis weight) of the sheet (G) and the smaller the size of the sheet (G), the smaller the size of the sheet (G), especially the size of a business card (minimum size in this example). ), the sheet (G) tends to skew. Alternatively/further, when a plurality of originals G of different sizes are conveyed in one job (mixed loading mode), the largest sized originals G among the originals G to be conveyed are conveyed in a pair of While the document G is supported from both sides by the sheet regulating member, the small size document G is supported only on one side of one of the sheet regulating members, so the document G tends to be skewed.

In this regard, the control unit 260 selects a plurality of sheet type modes (in this example, plain paper mode, thick paper mode, thin paper mode, mixed-load mode, business card mode) can be selected (see dashed frame α2 in FIG. 7B), and one of a plurality of sheet type modes (in this example, plain paper mode, thick paper mode, thin paper mode, mixed-load mode, business card mode). When one is selected, the first registration skew correction mode MD1 or the second registration skew correction mode MD2 is executed.

By doing so, the first registration skew correction mode (one or more but less than a plurality of skew corrections, in this example, one time) is performed according to the type of the sheet (G), or the second registration skew correction mode is performed. A correction mode (multiple skew corrections, two in this example) can be performed, whereby the number of sheet skew corrections can be changed according to the type of sheet (G).

As shown in FIG. 7A, in the normal mode, the first selection screen S1 of the display unit 152 displays any one of plain paper mode, thick paper mode, thin paper mode, mixed mode, business card mode, and skew correction setting mode. are displayed so that they can be selected by the user. FIG. 7A shows a state in which the plain paper mode is selected.

In this example, when the receiving unit 151 receives the plain paper mode or the thick paper mode as the sheet type mode, the control unit 260 performs the skew correction only once by the first registration roller pair 2331 . The skew correction mode MD1 is executed. Further, when the receiving unit 151 receives the thin paper mode, the mixed loading mode, or the business card mode as the sheet type mode, the control unit 260 performs skew correction by the first registration roller pair 2331 and skew correction by the second registration roller pair 2332. A second registration skew correction mode MD2 for performing skew correction twice is executed.

By the way, if the controller 260 executes the non-registration skew correction mode MDN and does not perform skew correction for all the sheets (G) of the plurality of registration roller pairs 233 to 233 (2331, 2332), The skew correction of the sheet (G) cannot be performed.

In this regard, in the present embodiment, the control unit 260 performs skew correction of the sheet (G) as skew correction other than skew correction by the plurality of registration roller pairs 233 to 233 (2331, 2332). ) for correcting skew by image processing (see FIG. 4).

Then, the control unit 260 can select a skew correction setting mode for executing the image processing skew correction mode MDP as a setting mode on the first selection screen S1 shown in FIG. 7A (see broken line frame α3 in FIG. 7B). , when the skew correction setting mode is selected, the non-registration skew correction mode MDN is executed to perform skew correction on all of the plurality of registration roller pairs 233 to 233 (2331, 2332). The skew correction mode MDP (see FIG. 4) is executed.

By doing this, even when the non-registration skew correction mode MDN is executed and skew correction is not performed for all the sheets (G) of the plurality of registration roller pairs 233 to 233 (2331, 2332), the sheet (G) skew correction can be performed.

Moreover, the skew of the sheet (G) can be easily corrected by image processing. Here, as the image processing for correcting the skew of the sheet (G), based on the detection result of the image detection unit (image sensor) that detects the image of the sheet (G), the leading edge and the trailing edge of the sheet (G); In addition, both side edges of the sheet (G) in the width direction W perpendicular to the conveying direction H are detected, and the shape formed by the leading edge, the trailing edge, and both side edges of the detected sheet is defined as a right-angled square having four right angles. This is image processing to shape. This image processing can be performed by a conventionally known method, and detailed description thereof is omitted here.

<Second embodiment>
In the sheet conveying device (200) according to the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

By the way, the user can set the number of times of skew correction for the sheet (G) in various setting modes (in this example, plain paper mode, thick paper mode, thin paper mode, mixed loading mode, business card mode, and skew correction setting mode). You may want to set it to the number of times

In this regard, in the present embodiment, the control unit 260 controls non-registration skew feeding for each setting mode (in this example, plain paper mode, thick paper mode, thin paper mode, mixed paper mode, business card mode, and skew correction setting mode). Any one of the correction mode MDN, the first registration skew correction mode MD1, and the second registration skew correction mode MD2 can be set.

8A and 8B show non-registration skew correction mode MDN, first registration mode, and first registration mode for each setting mode (in this example, plain paper mode, thick paper mode, thin paper mode, mixed paper mode, business card mode, and skew correction setting mode). FIG. 11 is a plan view showing a first setting screen T1 for setting one of a skew correction mode MD1 and a second registration skew correction mode MD2; FIG. 8A shows the initial setting state of the normal mode, and FIG. 8B shows that the normal mode shown in FIG. 8A is changed from the first registration skew correction mode MD1 of the plain paper mode to the second registration skew correction mode MD2. A setting example is shown.

By doing this, in various setting modes (in this example, plain paper mode, thick paper mode, thin paper mode, mixed loading mode, business card mode, and skew correction setting mode), the number of times of skew correction for the sheet (G) can be set as desired. can be changed to the number of

<Third Embodiment>
In the sheet conveying device (200) according to the third embodiment, the same components as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted.

(Silent priority mode)
9A is a plan view showing an example of the second selection screen S2 of the display section 152. FIG. FIG. 9B is a table showing an example of a combination of the non-registration skew correction mode MDN and the first registration skew correction mode MD1 performed according to the setting mode, together with the normal mode.

By the way, in a quiet environment where the rotation start sound of the registration roller pair 233 (especially the rotation start sound when thick paper is conveyed) is uncomfortable for the user, the user may use the plurality of registration roller pairs 233 to 233 (2331, 2332). There are cases where it is desired to reduce the number of skew corrections.

In this respect, in the present embodiment, the control unit 260 can select a silent priority mode in which silent is prioritized as a setting mode (operation mode) on the second selection screen S2 shown in FIG. α4), when the silent priority mode is selected, the non-registration skew correction mode MDN or the first registration skew correction mode MD1 is performed.

By doing this, even in a quiet environment where the rotation start sound of the registration roller pair 233 makes the user uncomfortable, the number of times of skew correction by the plurality of registration roller pairs 233 to 233 (2331, 2332) can be reduced or eliminated. be able to.

As shown in FIG. 9A, the second selection screen S2 of the display unit 152 displays any one of normal paper mode, thick paper mode, thin paper mode, mixed mode, business card mode, and skew correction setting mode in the silent priority mode. are displayed so that they can be selected by the user. FIG. 9A shows a state in which the cardboard mode is selected.

In the storage unit 262, as shown in FIG. 9B, in the silent priority mode, for each setting mode (in this example, plain paper mode, thick paper mode, thin paper mode, mixed loading mode, business card mode, and skew correction setting mode), A non-registration skew correction mode MDN or a first registration skew correction mode MD1 is stored in advance.

In this example, the non-registration skew correction mode MDN is set in advance in the plain paper mode, thick paper mode, thin paper mode, and skew correction setting mode in the “silent priority mode” storage area of the storage unit 262 . Also, in the mixed loading mode and the business card mode, the first registration skew correction mode MD1 is set in advance.

When the receiving unit 151 receives an operation for selecting one of the setting modes (for example, thick paper mode) (see FIG. 9A), the control unit 260 selects a mode (for example, non-registration mode) corresponding to the received setting mode (for example, thick paper mode). skew correction mode MDN) is executed.

10A and 10B show non-registration skew correction mode MDN or first registration mode for each setting mode (in this example, plain paper mode, thick paper mode, thin paper mode, mixed paper mode, business card mode, and skew correction setting mode). FIG. 9 is a plan view showing a second setting screen T2 for setting the skew correction mode MD1; FIG. 10A shows the initial setting state of the silent priority mode, and FIG. 10B shows that the non-registration skew correction mode MDN of the thin paper mode is changed to the first registration skew correction mode MD1 in the silent priority mode shown in FIG. 10A. A setting example is shown.

By doing this, in various setting modes (in this example, plain paper mode, thick paper mode, thin paper mode, mixed loading mode, business card mode, and skew correction setting mode), the number of times of skew correction for the sheet (G) can be set as desired. can be changed to the number of

(Image quality priority mode)
11A is a plan view showing an example of the third selection screen S3 of the display section 152. FIG. FIG. 11B is a chart showing an example of a combination of the first registration skew correction mode MD1 and the second registration skew correction mode MD2 performed according to the setting mode, together with the normal mode and the silent priority mode.

By the way, a user may want to increase the number of times of skew correction by a plurality of registration roller pairs 233 to 233 (2331, 2332) giving priority to image quality. Further, in the image processing skew correction mode, skew correction is performed by image processing, so the image quality tends to deteriorate. This is particularly noticeable when image processing is performed on a binary image (for example, when oblique lines become stepped due to image processing).

In this regard, in the present embodiment, the control unit 260 can select an image quality priority mode that prioritizes image quality as a setting mode (operation mode) on the third selection screen S3 shown in FIG. α5), when the image quality priority mode is selected, the first registration skew correction mode MD1 or the second registration skew correction mode MD2 (for example, the second registration skew correction mode MD2) is executed.

By doing so, it is possible to increase the number of skew corrections by the plurality of registration roller pairs 233 to 233 (2331, 2332) while giving priority to image quality. Further, since skew correction is performed by the pair of registration rollers 233, deterioration of image quality can be avoided.

As shown in FIG. 11A, in the image quality priority mode, the third selection screen S3 of the display unit 152 displays any one of plain paper mode, thick paper mode, thin paper mode, mixed mode, business card mode, and skew correction setting mode. are displayed so that they can be selected by the user. FIG. 11A shows a state in which the skew correction setting mode is selected.

In the storage unit 262, as shown in FIG. 11B, in the image quality priority mode, for each setting mode (in this example, plain paper mode, thick paper mode, thin paper mode, mixed loading mode, business card mode, and skew correction setting mode), A first registration skew correction mode MD1 or a second registration skew correction mode MD2 (for example, a second registration skew correction mode MD2) is stored in advance.

In this example, in the "image quality priority mode" storage area of the storage unit 262, the second registration skew correction mode MD2 is set in the plain paper mode, thick paper mode, thin paper mode, mixed paper mode, business card mode, and skew correction setting mode. preset.

When the receiving unit 151 receives an operation for selecting one of the setting modes (for example, the skew correction setting mode) (see FIG. 11A), the control unit 260 selects the selected setting mode (for example, the skew correction setting mode). mode (for example, second registration skew correction mode MD2) is executed.

12A and 12B show the first registration skew correction mode MD1 or the second registration skew correction mode MD1 or the second registration skew correction mode for each setting mode (in this example, plain paper mode, thick paper mode, thin paper mode, mixed paper mode, business card mode, and skew correction setting mode). FIG. 11 is a plan view showing a third setting screen T3 for setting a registration skew correction mode MD2; FIG. 12A shows the initial setting state of the image quality priority mode, and FIG. 12B shows that the image quality priority mode shown in FIG. 12A is changed from the second registration skew correction mode MD2 of the thick paper mode to the first registration skew correction mode MD1. A setting example is shown.

By doing this, in various setting modes (in this example, plain paper mode, thick paper mode, thin paper mode, mixed loading mode, business card mode, and skew correction setting mode), the number of times of skew correction for the sheet (G) can be set as desired. can be changed to the number of

<Fourth Embodiment>
In this embodiment, the sheet conveying device (200) comprises a supply roller 222 as shown in FIGS. 3, 5 and 6A to 6C. The supply roller 222 is provided closest to the plurality of registration roller pairs 233 on the upstream side in the conveying direction H of the sheet (G) from the plurality of registration roller pairs 233 .

By the way, as shown in FIGS. 6A to 6C, the supply roller 222 is normally provided at one central portion in the width direction W of the sheet (G). Then, when the registration roller pair provided on the downstream side in the conveying direction H of the sheet (G) from the supply roller 222 is the registration roller pair (first registration roller pair 2331) closest to the supply roller 222, the rotation is stopped. The sheet (G) pushed into the pair of registration rollers (2331) closest to the inner supply roller 222 (see FIGS. 6A and 6B) is provided at one central portion in the width direction W of the sheet (G). Since the sheet (G) is nipped only by the supply roller 222, the sheet (G) pushed into the registration roller pair (2331) closest to the supply roller 222 that is not rotating is not bound by anything other than the supply roller 222. Therefore, skew correction can be performed to a large extent. On the other hand, the sheet (G) pushed into the downstream side registration roller pair (second registration roller pair 2332) which is provided on the downstream side of the registration roller pair (2331) closest to the supply roller 222 and whose rotation is stopped. (see FIG. 6C), depending on the size of the sheet (G) [in this example, if the size is larger than the minimum size (see FIG. 6A)] in the width direction W of the sheet (G), from the downstream registration roller pair (2332) Since the rollers (2331c to 2331c) provided at a plurality of locations of the upstream roller pair (first registration roller pair 2331) are also pinched, it is pushed into the downstream registration roller pair (2332) that is not rotating. The sheet (G) is bound by a plurality of roller portions (2331c to 2331c) of the roller pair (2331) on the upstream side, and it is impossible to correct the skew to a large extent.

Further, when the sheet (G) is skewed, the lateral deviation of the sheet (G) in the width direction W increases as the sheet (G) is further away from the supply roller 222 .

In this regard, in the present embodiment, the registration roller pair (2331, 2332) that performs skew correction in the registration skew correction mode MD is more sheet-oriented than the supply roller 222 among the plurality of registration roller pairs 233-233. The pair of registration rollers (2331) closest to the supply roller 222 on the downstream side in the transport direction H in (G).

By doing so, the sheet (G) pushed into the pair of registration rollers (2331) closest to the supply roller 222 whose rotation is stopped is pushed into the supply roller 222 other than the supply roller 222 provided at one point in the central portion in the width direction W. Without being restricted, the skew correction can be performed to a large extent, and the lateral shift in the width direction W can be suppressed to a small amount.

<Fifth Embodiment>
In the present embodiment, in the second registration skew correction mode MD2, the sheet (G) is directed to the registration roller pair (2331) closest to the supply roller 222 among the plurality of registration roller pairs 233-233. The first pressing amount (first pressing time) is the second pressing amount (second pressing time) of the sheet (G) to the registration roller pair (2332) other than the registration roller pair (2331) closest to the supply roller 222. bigger than Here, the first pressing amount (first pressing time) and the second pressing amount (second pressing time) refer to the amount of sheet (G) from when the sheet collides with the pair of registration rollers to when the sheet (G) is stopped. It is the conveying amount (conveying time), so to speak, the bending amount of the leading edge of the sheet (G).

By doing this, the skew is largely corrected by the registration roller pair (2331) closest to the supply roller 222, and the registration roller pair (2332) other than the registration roller pair (2331) closest to the supply roller 222 corrects the supply roller 222. It is possible to perform a smaller skew correction than the skew correction at the registration roller pair (2331) closest to . As a result, the large skew is first corrected by the registration roller pair (2331) closest to the supply roller 222, and then the registration roller pair (2332) other than the registration roller pair (2331) closest to the supply roller 222 is corrected. can accurately correct small skews.

<Sixth embodiment>
In this example, the sheet conveying device is a document conveying device 200 that reads a document G, which is a sheet, at a predetermined reading position R on a sheet conveying path 231 . The sheet conveying device (200) feeds the supply roller 222 provided closest to the plurality of registration roller pairs 233 to 233 on the upstream side in the conveying direction H of the document G from the plurality of registration roller pairs 233 to 233. I have.

By the way, it is conceivable to provide the registration roller pair 233 closest to the reading position R on the upstream side in the conveying direction H of the document G from the reading position R. ), the space between the pair of registration rollers and the reading position R is limited, and it is difficult to provide a registration clutch for the pair of registration rollers. Further, the pair of rollers provided closest to the reading position R on the upstream side in the transport direction H of the document G from the reading position R participates in the operation of reading the image of the document G, so that the registration clutch can be turned on and off. Vibration tends to affect the read image of the document G.

In this regard, the sheet conveying device (200) includes a pre-reading conveying roller pair 234 provided closest to the reading position R on the upstream side in the conveying direction H of the document G relative to the reading position R. The plurality of registration roller pairs 233 to 233 are a first registration roller pair 2331 provided on the upstream side in the transport direction H of the document G from the pre-reading transport roller pair 234 , and and a second registration roller pair 2332 provided downstream in the transport direction H and upstream of the pre-reading transport roller pair 234 (closest to the upstream pre-reading transport roller pair 234 in this example). There are two registration roller pairs (2331, 2332).

By doing so, there is no need to provide a registration clutch in the pre-reading transport roller pair 234, and the space between the pre-reading transport roller pair 234 and the reading position R can be narrowed in order to read the minimum size document G (especially a business card). can do. In addition, since the second registration roller pair 2332 is provided on the upstream side of the pre-reading transport roller pair 234, the on/off vibration of the registration clutch of the second registration roller pair 2332 is less likely to affect the read image of the document G. be able to.

In the non-registration skew correction mode MDN, the control unit 260 does not perform skew correction with both the first registration roller pair 2331 and the second registration roller pair 2332 . The control unit 260 performs skew correction using the first registration roller pair 2331 in the first registration skew correction mode MD1. In the second registration skew correction mode MD2, the control unit 260 also performs skew correction using both the first registration roller pair 2331 and the second registration roller pair 2332 .

As a result, depending on the usage conditions of the user, for example, the skew correction of the two registration roller pairs (2331, 2332) can be performed in a silent environment where the rotation start sound of the registration roller pair 233 makes the user uncomfortable. can be prevented.

(Other embodiments)
In the embodiment described above, the plurality of registration roller pairs 233 are two, but may be three or more. Also, although the sheet is the document G, it may be a recording sheet. In this case, a plurality of registration roller pairs are provided in the image forming apparatus main body 101 .

The present invention is not limited to the embodiments described above, but can be implemented in various other forms. Therefore, the embodiment concerned is merely an example in all respects, and should not be construed in a restrictive manner. The scope of the present invention is indicated by the claims and is not restricted by the text of the specification. Furthermore, all modifications and changes within the equivalence range of claims are within the scope of the present invention.

100 image forming apparatus 150 operation display unit 151 reception unit 152 display unit 200 document feeder (an example of a sheet feeder)
210 document placement tray 220 document supply section 221 drawing roller 222 supply roller 223 separation roller 224 supply drive transmission mechanism 230 document conveyance section 231 sheet conveyance path 232 conveyance guide 233 registration roller pair 2331 first registration roller pair 2332 second registration roller pair 234 pre-reading conveying roller pair 235 post-reading conveying roller pair 236 pre-discharge conveying roller pair 240 document discharge section 241 discharge roller pair 250 document discharge tray 260 control section 261 processing section 262 storage section 270 conveyance drive section 280 conveyance drive transmission mechanism 281 First registration clutch 282 Second registration clutch 291 First conveyance detection section 292 Second conveyance detection section 293 Third conveyance detection section G Document G1 Leading edge H Conveyance direction MD Registration skew correction mode MD1 First registration skew correction mode MD2 2 registration skew correction mode MDN non-registration skew correction mode MDP image processing skew correction mode R reading position S1 first selection screen S2 second selection screen S3 third selection screen T1 first setting screen T2 second setting screen T3 3 setting screen W width direction d1 first distance d2 second distance d3 third distance

Claims (10)

A sheet conveying device in which a plurality of registration roller pairs for performing skew correction of a sheet conveyed on a sheet conveying path are provided at intervals in a conveying direction of the sheet,
a non-registration skew correction mode in which the skew correction is not performed for all of the plurality of registration roller pairs;
a registration skew correction mode in which the skew correction is performed by one or more registration roller pairs out of the plurality of registration roller pairs;
A sheet conveying apparatus that performs a non-registration skew correction mode or a registration skew correction mode according to a setting mode set by a user. The sheet conveying device according to claim 1,
The registration skew correction mode includes a first registration skew correction mode in which the skew correction is performed by one or more registration roller pairs out of the plurality of registration roller pairs and less than the plurality of registration roller pairs; a second registration skew correction mode in which the skew correction is performed by all the roller pairs;
A sheet conveying apparatus that performs any one of the non-registration skew correction mode, the first registration skew correction mode, and the second registration skew correction mode according to the setting mode. The sheet conveying device according to claim 2,
A plurality of types of sheets can be conveyed as the sheet,
A plurality of sheet type modes can be selected as the setting mode according to the sheet type,
A sheet conveying apparatus that executes the first registration skew correction mode or the second registration skew correction mode when one of the plurality of sheet type modes is selected. The sheet conveying device according to any one of claims 1 to 3,
an image processing skew correction mode for correcting the skew of the sheet by image processing as skew correction other than the skew correction by the plurality of registration roller pairs;
A skew correction setting mode for executing the image processing correction mode can be selected as the setting mode,
When the skew correction setting mode is selected, the image processing skew correction mode is selected instead of executing the non-registration skew correction mode and not performing the skew correction for all of the plurality of registration roller pairs. A sheet conveying device characterized by executing: The sheet conveying device according to any one of claims 1 to 4,
The registration skew correction mode includes a first registration skew correction mode in which the skew correction is performed by one or more registration roller pairs out of the plurality of registration roller pairs and less than the plurality of registration roller pairs; a second registration skew correction mode in which the skew correction is performed by all the roller pairs;
Any one of the non-registration skew correction mode, the first registration skew correction mode, and the second registration skew correction mode can be set for each of the setting modes. Sheet conveying device. The sheet conveying device according to any one of claims 1 to 5,
The registration skew correction mode has a first registration skew correction mode in which the skew correction is performed by one or more registration roller pairs out of the plurality of registration roller pairs and less than the plurality of registration roller pairs,
A silent priority mode that prioritizes silent is selectable as the setting mode,
The sheet conveying apparatus, wherein the non-registration skew correction mode or the first registration skew correction mode is performed when the silent priority mode is selected. The sheet conveying device according to any one of claims 1 to 6,
a supply roller provided on the upstream side in the sheet conveying direction of the plurality of registration roller pairs;
The registration roller pair that performs the skew correction in the registration skew correction mode is located closest to the supply roller downstream of the supply roller in the sheet conveying direction among the plurality of registration roller pairs. A sheet conveying device comprising a pair of registration rollers that are close to each other. The sheet conveying device according to claim 7,
Among the plurality of registration roller pairs, the first pushing amount of the sheet to the registration roller pair closest to the supply roller is the sheet to the registration roller pair other than the registration roller pair closest to the supply roller. is larger than the second pushing amount of the sheet conveying apparatus. The sheet conveying device according to any one of claims 1 to 8,
a document feeder for reading the sheet document at a predetermined reading position on the sheet conveying path;
a supply roller provided on the upstream side in the transport direction of the document from the plurality of registration roller pairs; and a pre-reading transport roller pair,
The plurality of registration roller pairs include: a first registration roller pair provided upstream of the pre-reading conveying roller pair in the document conveying direction; two registration roller pairs including a second registration roller pair provided downstream and upstream of the pre-reading conveying roller pair;
In the non-registration skew correction mode, the skew correction is not performed by both the first pair of registration rollers and the second pair of registration rollers,
The registration skew correction mode includes a first registration skew correction mode in which the skew correction is performed by the first registration roller pair, and a skew correction mode in which the skew correction is performed by both the first registration roller pair and the second registration roller pair. and a second registration skew correction mode for performing the above. An image forming apparatus comprising the sheet conveying device according to any one of claims 1 to 9.

Images