JP6774006B2 - Sheet-like body transfer device and image forming device - Google Patents

Description

The present invention relates to a sheet-like body transport device that performs skew correction and lateral displacement correction of a sheet-like body that is transported along a transport path, and a copier, a printer, a facsimile, or a combination machine thereof provided with the transport device. It relates to an image forming apparatus such as an offset printing machine.

In an image forming apparatus such as a copying machine or a printer, for example, as in Patent Document 1 (Japanese Unexamined Patent Publication No. 9-175649), a pair of holding rollers arranged in a sheet-shaped transport path is tilted with respect to the transport path. Some sheets are moved in the direction and the width direction to perform skew correction and lateral deviation correction of the sheet-like body.

In the sheet-shaped body conveying device of Patent Document 1 (Japanese Unexamined Patent Publication No. 9-175649), the sheet-shaped body is guided to the holding roller pair by a pair of upper and lower guide plates arranged on the upstream side of the holding roller pair. (Fig. 3 of Patent Document 1). However, a predetermined gap is formed between the guide plates in order to suppress the occurrence of jam, and the sheet-like body being transported in the gap unexpectedly flutters, and the fluttering causes the sheet-like body to skew. It turned out to occur.

The present invention is a sheet-shaped body transporting device capable of skew correction and lateral displacement correction of a sheet-shaped body by picking up and returning a pair of rotating bodies that transport the sheet-shaped body, and the sheet-like body when plunging into a nip portion. The purpose is to suppress the occurrence of skew by suppressing the fluttering of the body.

In order to solve the above problems, the present invention comprises a pair of rotating bodies that sandwich and convey a sheet-like body supplied to a transport path, and a pair of rotating bodies that hold the pair of rotating bodies and sandwich the sheet-like body. It has a rotating body pair holding member that can turn along the transport surface including the nip portion and can shift and move in the width direction of the transport path, and corresponds to the posture of the sheet-like body that is about to enter the nip portion. The rotating body pair is greeted and operated so as to move the rotating body pair to the facing position, and the rotating body pair is facing the rotating body pair in a state where the sheet-like body has entered the nip portion at the facing position. In the sheet-shaped body transport device that corrects the posture of the sheet-shaped body by returning and operating the rotating body pair holding member so as to move from the position to a predetermined initial position, the rotating body pair is the upper stage of the transport path. A pair of downstream rotating members having an upper downstream rotating member arranged in the upper stage and a lower downstream rotating member arranged in the lower stage to form the nip portion, and the transport path on the upstream side of the downstream rotating member pair. A pair of upstream rotating members having an upper upstream rotating member and a lower upstream rotating member arranged apart from each other, between the upper downstream rotating member and the upper upstream rotating member, and the lower downstream side. It is characterized by having an endless orbiting member that is hung between the rotating member and the lower upstream side rotating member, and having a pair of endless orbiting members that taper from the nip portion toward the upstream side. It is a sheet-like body transport device.

The sheet-shaped body transport device according to the present invention has an endless orbiting member pair that is hung between a pair of downstream rotating members and a pair of upstream rotating members and spreads in a tapered shape from the nip portion toward the upstream side. Therefore, it is possible to guide the tip end portion of the sheet-like body to the nip portion while suppressing the fluttering of the tip end portion of the sheet-like body with the endless rotating member pair. Therefore, it is possible to suppress the occurrence of skew due to the fluttering of the sheet-like body.

It is an overall block diagram of the image forming apparatus which concerns on embodiment of this invention. It is an enlarged view which shows the image-forming part of an image forming apparatus. The outline of the sheet-like body transporting apparatus which concerns on embodiment of this invention is shown, (a) is a top view, (b) is a side view. The outline of the sheet-like body transporting apparatus which concerns on embodiment of this invention is shown, (a) is the perspective view which omitted the upper and lower guide plates, (b) is the perspective view which includes the upper and lower guide plates, (c) is (b). It is a cross-sectional view taken along the line cc of). It is sectional drawing of the sheet-like body transfer apparatus which concerns on embodiment of this invention. 4A is a plan view taken along the line BB of FIG. 4A. It is an input / output connection diagram of a control unit. (A) to (d) are diagrams showing the lateral displacement correction operation and the skew correction operation of the rotating body pair holding member. It is a figure which shows the lateral deviation correction amount Δy and the skew correction amount Δx of a rotating body pair holding member. The skew correction error of the sheet-like body conveying device will be described, where (a) is a top view before skew correction and (b) is a side view before skew correction. The skew correction error of the sheet-like body conveying device will be described, where (a) is a top view after skew correction and (b) is a side view after skew correction. It is a figure which shows the flowchart of the sheet-like body transfer apparatus. The first stage of sheet transport is shown, (a) is a top view of a state in which the sheet-like body P reaches one of the two skew detection sensors 145 in a skewed state, and (b) is a top view of the sheet-like body P skewed. The top view and (c) of the state where the skew detection sensor 145 is reached without being laterally displaced are side views. The second stage of sheet transport is shown, (a) is a top view (b) is a side view. The third stage of sheet transport is shown, (a) is a top view (b) is a side view. The fourth stage of sheet transport is shown, (a) is a top view (b) is a side view. The fifth stage of sheet transport is shown, (a) is a top view (b) is a side view. The sixth stage of sheet transport is shown, (a) is a top view (b) is a side view. The seventh stage of sheet transport is shown, (a) is a top view (b) is a side view. The first modification of the pair of rotating bodies is shown, (a) is a perspective view without a guide plate, (b) is a perspective view including a guide plate, and (c) is a cross-sectional view taken along the line cc of (b). is there. A second modification of the pair of rotating bodies is shown, where FIG. 3A is a perspective view including a guide plate, and FIG. 3B is a sectional view taken along line bb of FIG. A third modified example of the pair of rotating bodies is shown, where FIG. 3A is a perspective view including a guide plate, and FIG. 3B is a sectional view taken along line bb of FIG. A modification of the skew detection sensor of the sheet-like body transport device is shown, where (a) is a top view before skew detection and (b) is a side view before skew detection. A modification of the skew detection sensor of the sheet-like body transport device is shown, where (a) is a top view after skew detection and (b) is a side view after skew detection. It is sectional drawing which shows the deformation example of the position of the support shaft of the rotating body pair holding member of a sheet-like body transporting apparatus. The mechanism of skew generation in the conventional sheet-like body conveying device will be described. FIG. 3A is a perspective view showing a fluttering state of the sheet-like body, and FIG. 3B is a plan view showing the skew amount of the sheet-like body. .. (A) is a view of a fluttering sheet-like body viewed from the upstream side in the transport direction, and (b) is a left side view of (a). It is a side view of the sheet-like body in which skew was generated just before rushing into a nip part. It is a figure which shows the speed change of the tip part of a sheet-like body. It is a figure which shows the change of the skew amount of a sheet-like body.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In each drawing, components such as members and components having the same function or shape will be described by giving the same reference numerals as much as possible, and then the description thereof will be omitted.

(Image forming device)

First, the configuration and operation of the entire image forming apparatus will be described with reference to FIGS. 1 and 2. FIG. 1 is a configuration diagram showing a printer as an image forming apparatus, and FIG. 2 is an enlarged view showing an image forming portion thereof. As shown in FIG. 1, an intermediate transfer belt device 15 having an intermediate transfer belt 8 is installed in the center of the main body of the image forming apparatus 100.

Image forming portions 6Y, 6M, 6C, and 6K corresponding to each color (yellow, magenta, cyan, and black) are arranged side by side so as to face the intermediate transfer belt 8. The resist correction unit 30 as the lateral deviation correction means is arranged in the straight transfer path K2 on the lower right side of the intermediate transfer belt device 15. Below the straight transfer path K2, a paper feeding unit 26 containing a sheet-like body P as a recording medium or a transfer medium is arranged.

FIG. 2 is an enlargement of the image forming unit 6Y corresponding to the yellow color of the image forming apparatus. The image forming unit 6Y includes a photoconductor drum 1Y, a charged part 4Y arranged around the photoconductor drum 1Y, and a developing unit. It is composed of 5Y, a cleaning unit 2Y, a static elimination unit, and the like. Then, an image forming process (charging step, exposure step, developing step, transfer step, cleaning step) is performed on the photoconductor drum 1Y to form a yellow image on the photoconductor drum 1Y.

The other three image-forming units 6M, 6C, and 6K also have almost the same configuration as the image-forming unit 6Y corresponding to yellow, except that the toner colors used are different, and correspond to each toner color. An image is formed. Hereinafter, the description of the other three image forming units 6M, 6C, and 6K will be appropriately omitted, and only the image forming unit 6Y corresponding to yellow will be described.

With reference to FIG. 2, the photoconductor drum 1Y is rotationally driven in the counterclockwise direction in FIG. 2 by a drive motor (not shown). Then, the surface of the photoconductor drum 1Y is uniformly charged at the position of the charging portion 4Y (charging step). After that, the surface of the photoconductor drum 1Y reaches the irradiation position of the laser beam L emitted from the exposure unit 7, and an electrostatic latent image corresponding to yellow is formed by exposure scanning at this position (exposure step). ..

After the electrostatic latent image corresponding to yellow is formed, the surface of the photoconductor drum 1Y reaches a position facing the developing unit 5Y, and the electrostatic latent image is developed at this position to develop a yellow toner image (yellow toner image). Image) is formed (development process). After that, the surface of the photoconductor drum 1Y reaches a position facing the intermediate transfer belt 8 and the transfer roller 9Y, and the toner image on the photoconductor drum 1Y is transferred onto the intermediate transfer belt 8 at this position (primary). Transfer process). At this time, a small amount of untransferred toner remains on the photoconductor drum 1Y.

The surface of the photoconductor drum 1Y reaches a position facing the cleaning unit 2Y, and the untransferred toner remaining on the photoconductor drum 1Y at this position is collected in the cleaning unit 2Y by the cleaning blade 2a (cleaning step). .. Finally, the surface of the photoconductor drum 1Y reaches a position facing the static elimination portion (not shown), and the residual potential on the photoconductor drum 1 is removed at this position. In this way, a series of image forming processes performed on the photoconductor drum 1Y is completed.

The above-mentioned image forming process is also performed in the other image forming sections 6M, 6C, and 6K in the same manner as in the yellow image forming section 6Y. That is, the laser beam L based on the image information is irradiated from the exposure unit 7 arranged above the image-forming unit toward the photoconductor drums 1M, 1C, and 1K of the image-forming units 6M, 6C, and 6K. Will be done.

Specifically, the exposure unit 7 emits a laser beam L from a light source, scans the laser beam L with a rotation-driven polygon mirror, and irradiates the photoconductor drum via a plurality of optical elements. Then, the toner images (images) of each color formed on each photoconductor drum through the development step are superimposed and transferred on the intermediate transfer belt 8 as the image carrier. In this way, a color image is formed on the intermediate transfer belt 8.

The intermediate transfer belt device 15 includes an intermediate transfer belt 8, four transfer rollers 9Y, 9M, 9C, 9K, a drive roller 12A, an opposing roller 12B, tension rollers 12C to 12F, an intermediate transfer cleaning unit 10, and the like. The intermediate transfer belt 8 is stretched and supported by a plurality of roller members 12A to 12F, and is endlessly moved in the direction of the arrow in FIG. 1 by rotational driving of one roller member (driving roller) 12A.

Each of the four transfer rollers 9Y, 9M, 9C, and 9K forms a primary transfer nip by sandwiching the intermediate transfer belt 8 between the photoconductor drums 1Y, 1M, 1C, and 1K, respectively. Then, a transfer voltage (transfer bias) opposite to the polarity of the toner is applied to the transfer rollers 9Y, 9M, 9C, and 9K.

Then, the intermediate transfer belt 8 (belt-shaped image carrier) travels in the direction of the arrow and sequentially passes through the primary transfer nips of the transfer rollers 9Y, 9M, 9C, and 9K. In this way, the toner images of each color on the photoconductor drums 1Y, 1M, 1C, and 1K are superimposed on the intermediate transfer belt 8 and first-order transferred.

After that, the intermediate transfer belt 8 on which the toner images of each color are superimposed and transferred reaches a position (image transfer portion) facing the secondary transfer roller 19. At this position, the opposing roller 12B sandwiches the intermediate transfer belt 8 with the secondary transfer roller 19 to form a secondary transfer nip (image transfer portion).

Then, the four-color toner images formed on the intermediate transfer belt 8 are transferred onto the sheet-like body P such as transfer paper conveyed to the position of the secondary transfer nip (secondary transfer step). At this time, untransferred toner that has not been transferred to the sheet-like body P remains on the intermediate transfer belt 8.

After the secondary transfer step, the intermediate transfer belt 8 reaches the position of the intermediate transfer cleaning unit 10. Then, at this position, the untransferred toner on the intermediate transfer belt 8 is removed. In this way, a series of transfer processes performed on the intermediate transfer belt 8 is completed.

Here, referring to FIG. 1, the sheet-like body P conveyed to the position of the secondary transfer nip is fed by the paper feed roller 27 from the paper feed unit 26 arranged below the apparatus main body 100. It is conveyed via the paper feed path K1, the straight transfer paths K2, and K3. A plurality of sheet-like bodies P such as transfer paper are stacked and stored in the paper feed unit 26. Then, when the paper feed roller 27 is rotationally driven in the counterclockwise direction in FIG. 1, the top sheet-like body P is fed toward the paper feed path K1.

The sheet-like body P fed to the paper feed path K1 is then conveyed to the resist correction unit 30 through the straight transfer path K2. The sheet-like body P conveyed to the resist correction unit 30 is subjected to skew correction (skew correction), horizontal resist correction (positional deviation correction in the width direction), and vertical resist correction (positional deviation correction in the conveying direction) by the resist correction unit 30. Will be done. After that, the sheet-like body P is transferred toward the secondary transfer nip (image transfer unit) through the linear transfer path K3 at the transfer timing in accordance with the color image on the intermediate transfer belt 8. In this way, the desired color image is transferred onto the sheet-like body P.

The sheet-like body P on which the color image is transferred at the position of the secondary transfer nip is conveyed to the position of the fixing portion 20. Then, at this position, the color image transferred to the surface is fixed on the sheet-like body P by the heat and pressure of the fixing belt and the pressure roller. After that, the sheet-like body P is discharged to the outside of the apparatus by the paper ejection roller. The sheet-like body P discharged to the outside of the apparatus by the paper ejection roller is sequentially stacked on the stack portion as an output image.

In this way, a series of image forming processes in the image forming apparatus is completed. The process linear speed of the image forming apparatus in the present embodiment (running speed of the intermediate transfer belt 8 and transport speed of the sheet-like body P) is set to about 400 mm / sec.

(Structure / operation of developing unit)
Next, with reference to FIG. 2, the configuration and operation of the developing unit in the image forming unit will be described in more detail. The developing unit 5Y has a developing roller 51Y facing the photoconductor drum 1Y and a doctor blade 52Y facing the developing roller 51Y. Further, two transport screws 55Y arranged in the developer accommodating portion, a toner replenishment path 44Y communicating with the developer accommodating portion through an opening, a concentration detection sensor 56Y for detecting the toner concentration in the developer, and the like are provided. Have.

The developing roller 51Y is composed of a magnet fixed inside, a sleeve that rotates around the magnet, and the like. A two-component developer composed of a carrier and toner is housed in the developer accommodating portion.

The developing unit 5Y configured in this way operates as follows. The sleeve of the developing roller 51Y rotates in the direction of the arrow in FIG. Then, the developer supported on the developing roller 51Y by the magnetic field formed by the magnet moves on the developing roller 51Y as the sleeve rotates. Here, the developer in the developing unit 5Y is adjusted so that the ratio of toner (toner concentration) in the developing agent is within a predetermined range.

After that, the toner replenished in the developer accommodating portion circulates in the two isolated developing agent accommodating portions while being mixed and stirred together with the developer by the two transport screws 55Y (movement in the vertical direction on the paper surface of FIG. 2). ). Then, the toner in the developing agent is adsorbed on the carrier by triboelectric charging with the carrier, and is supported on the developing roller 51Y together with the carrier by the magnetic force formed on the developing roller 51Y.

The developer carried on the developing roller 51Y is conveyed in the direction of the arrow in FIG. 2 and reaches the position of the doctor blade 52Y. Then, the developer on the developing roller 51Y is conveyed to a position (development region) facing the photoconductor drum 1Y after the amount of the developer is adjusted appropriately at this position.

After that, the toner of the developer on the developing roller 51Y is adsorbed on the latent image formed on the photoconductor drum 1Y by the electric field formed in the developing region. The developer remaining on the developing roller 51Y after this adsorption reaches the upper part of the developing agent accommodating portion as the sleeve rotates, and is separated from the developing roller 51Y at this position.

(Structure of straight transport paths K2 and K3)

Next, the configurations of the straight transport paths K2 and K3 will be described with reference to FIGS. 1 and 3A. Horizontal straight transport paths K2 and K3 are provided along the transport direction of the sheet-shaped body P. The straight transfer paths K2 and K3 are formed by guide plates 41 and 42 installed so as to sandwich the front and back surfaces of the sheet-like body P to be conveyed, and a guide plate 43 that supports the lower surface of the sheet-like body P. ..

Along the transport direction of the straight transport paths K2 and K3, a transport roller pair 31 and a CIS (contact image sensor) 146 as a lateral displacement detecting member are arranged in order from the upstream side. Further, a skew detection sensor 145 (photosensors 145a and 145b) as a skew detection member, a resist rotating body pair 33, a photosensor 38, and a secondary transfer roller 19 are arranged in this order on the downstream side of the CIS 146. The sheet-like body transfer device 150 is configured by the transfer roller pair 31 to the photo sensor 38.

The transport roller pair 31 has a driven roller 31a on the upper stage side and a drive roller 31b on the lower stage side. The driven roller 31a of the transport roller pair 31 is arranged so as to be vertically movable with respect to the driven roller 31b having a fixed height, and the nip portion can be opened and closed. The vertical movement of the driven roller 31a is performed by the contact / detachment motor 158 (see FIG. 4C).

The drive roller 31b is connected to and driven by the transport drive motor 156 (see FIG. 4C). The resist rotating body pair 33 has an upper rotating body 33a and a lower rotating body 33b. Then, the resist rotating body pair 33 performs lateral resist correction and skew correction of the sheet-shaped body P by the widthwise shift movement and rotation operation of the rotating body-to-holding member 110 with the sheet-shaped body P sandwiched between the nip portions. Here, the shift movement in the width direction of the rotating body vs. holding member 110 is a shift movement in the width direction of the transport path. Further, the rotating operation of the rotating body pair holding member 110 is a rotating operation along the transport surface including the nip portion of the rotating body pair.

The photosensor 38 is arranged on the downstream side of the resist rotating body pair 33 in the transport direction of the sheet-shaped body P, and optically detects the tip of the sheet-shaped body P transported from the resist rotating body pair 33. .. Then, based on the detection result of the photo sensor 38, the transfer timing of the sheet-like body P transported toward the secondary transfer nip by the resist rotating body pair 33 is finely adjusted.

From the paper feed unit 26 of the image forming apparatus 100, the uppermost sheet of the sheet-like body P housed in the paper feed unit 26 is fed by the paper feed roller 27 toward the resist rotating body pair 33. The sheet-like body P is subjected to skew correction and lateral resist correction by the resist rotating body pair 33, and is further timed for secondary transfer in order to align with the image formed on the photoconductor drum 5. It is transported toward.

(Mechanism of skew generation due to fluttering of sheet-like body)
Here, the mechanism of skew generation due to the fluttering of the sheet-like body in the conventional sheet-like body transfer device will be described with reference to FIGS. 13 to 16. When the tip of the sheet-like body facing the holding roller pair flutters up and down and rushes into the nip part of the holding roller pair in the conventional sheet-like body conveying device, the timing of rushing into the nip on the left and right sides of the tip of the sheet-like body. It shifts.

For example, consider a case where the tip end portion of the sheet-like body P flutters downward and abuts diagonally against the lower holding roller 233b as shown in FIGS. 13 and 14. In this case, the tip of the sheet-like body P does not flutter and translate downward while remaining in the horizontal state, and the tip is tilted more or less. That is, assuming that the broken line in FIG. 13 is a horizontal state in which the sheet-like body P does not flutter, the tip portion of the sheet-like body P in which the flutter occurs is tilted as shown by the solid line in FIG. 13, for example. This inclination is higher on one side in the width direction (on the right side in the direction of the arrow in the figure) and lower on the other side (left side) with respect to the transport direction indicated by the arrow.

FIG. 14A is a view of the sheet-like body P at this time viewed from the upstream side to the downstream side in the transport direction, and FIG. 14B is a left side view thereof. As can be seen from FIG. 14, left P _L1 of the sheet product P is transported along the lower guide plate 242, the right P _R1 is transported in a state of being floated from the lower guide plate 242 by flap. Therefore, the tip portion left P _L of the sheet product P as shown in FIG. 14 (b) abuts against the lower nip roller 233b first.

Abutting circumferential surface position of the lower nip roller 233b to tip left P _L of the sheet product P when this impinges is curved inclined to the upper left to the conveying direction in FIG. 14 (b). Therefore, the tip portion left P _L of the sheet product P is moved at a predetermined linear velocity along the (upper left in FIG. 14 (b)) tangential position abutting the circumferential surface of the lower nip roller 233b, leftward horizontal The velocity component in the transport direction (horizontal direction) decreases.

On the other hand, the tip portion right P _R of the sheet product P, in the timing when the tip left P _L of the sheet product P is abuts against the lower nip roller 233b as the still abuts against the lower nip roller 233b folded Instead, it is conveyed at the horizontal linear speed as it is. Therefore, the distal end portion of the sheet product P is within a predetermined time until enters the nip portion of the nip roller pair 233, the moving distance of the distal end portion left P _L of the sheet product P progresses, advances the tip portion right P _R shorter than the movement distance, the tip portion left P _L is skew delayed form is generated. Figure 15 (a) (b) is an illustration the skew condition, the tip portion right P _R remains sheet product P in the form of sheet product P is skewed at the tip left P _L delay enters the nip portion Trying to.

Next, the state of change in the speed and skew of the tip portion of the sheet-shaped body P before and after the sheet-shaped body P passes through the sandwiching roller pair 233 will be described with reference to FIGS. 16A and 16B. Shall sheet product P is skewed in the form of delayed tip left P _L as shown in FIG. 15 (b), the left side P _L position of the sheet-shaped body distal portion in the skew state (left corner) and it is defined as the skew quantity difference in the conveying direction (arrow direction) of the right P _R position (right corner).

Figure 16A is a diagram plotting the time series change in the conveying direction of the velocity of the tip left P _L and right P _R of the sheet product P. Until the sheet-shaped body tip hits the lower nip roller 233b at the P1 tip portion left P _L (solid line) and the right P _R (dashed line) is conveyed at the same speed, tip left (solid line) at P1 When it hits the lower pinch roller, it slows down rapidly.

After that, as the position of the nip portion indicated by P2 is approached, the direction along the surface of the lower holding roller (forward upward inclination) returns to the horizontal transport direction, so that the speed of the tip of the sheet-like body also returns to the predetermined transport speed. At the same time, it rushes into the nip portion at P2 and is conveyed at a predetermined speed. On the other hand, the right tip (broken line) is slightly accelerated by the reaction force at which the left side of the tip is rapidly decelerated at P1, but is conveyed at a predetermined speed after entering the nip at P2.

FIG. 16B is a diagram in which the skew amounts defined as shown in FIG. 15B are plotted in time series. It is conveyed without skew until the tip of the sheet-like body hits the lower holding roller 233b at the time of P3. The amount of skew increases sharply at the moment when the left side of the tip portion hits the lower holding roller 233b in P3, and the amount of skew continues to increase until the tip portion of the sheet-like body enters the nip portion in P4. After the tip of the sheet-like body rushes into the nip at P4, the sheet is conveyed while maintaining the skew amount at the time of rushing.

As described above, when the lower guide plate 242 on the upstream side of the nip roller pair 233 is provided below the height position of the nip portion, the fluttering of the sheet-shaped body tip, the tip portion left P _L or one of right P _R is skew shape occurs delayed. Moreover, it is completely unpredictable which of the left and right skew will be delayed and how large the skew amount will be. Therefore, no matter how accurately the skew amount of the sheet-like body P is detected and the holding roller pair 233 is corrected so as to eliminate it, if fluttering occurs at the tip of the sheet-like body, the skew correction and the lateral displacement occur. There was a problem that an error occurred in both corrections.

(Sheet-like body transfer device according to the embodiment of the present invention)
In the embodiment of the present invention, by using an endless orbiting member pair for the resist rotating body pair 33 of the sheet-shaped body conveying device 150, skew generation due to the fluttering of the sheet-shaped body P described above is suppressed. Hereinafter, the sheet-like body transfer device 150 according to the present embodiment will be described with reference to FIGS. 3A to 4C. The sheet-shaped body transfer device 150 of the present embodiment is configured by the transfer roller pair 31, CIS146, skew detection sensors 145 (145a and 145b), and the resist rotating body pair 33. The sheet-shaped body conveying device 150 performs skew correction and lateral displacement correction of the sheet-shaped body P by the CIS 146, the skew detection sensor 145, and the resist rotating body pair 33.

As shown in FIG. 4A, the main body frame 151 is fixedly arranged below the resist rotating body pair 33 along the transport path K2, and the base frame 152 is fixed on the main body frame 151. The base frame 152 has two upper and lower horizontal plates 153 and 154, and a rotating body pair holding member 110 that supports the resist rotating body pair 33 is movably arranged in the horizontal direction on the upper horizontal plate 154. ing.

As shown in FIG. 4B, four free bearings 118 (ball transfers) are arranged on the upper surface of the upper horizontal plate 154 at positions corresponding to the four corners of the bottom surface of the rotating body pair holding member 110. On the free bearing 118, a rotating body pair holding member 110 is arranged so as to be movable back and forth and left and right in the horizontal direction.

As is known, the free bearing 118 has a steel ball 118b rotatably fitted in a recess of the pedestal 118a, and the top of the steel ball 118b is in point contact with the bottom surface of the rotating body vs. holding member 110. The lower half of the steel ball 118b is supported by a plurality of small-diameter steel balls 118c arranged on the inner surface of the recess to reduce the rotational load of the steel ball 118b. The minimum number of free bearings 118 is three, but in the illustrated example, four are arranged to ensure stable movement of the rotating body vs. holding member 110.

The rotating body pair holding member 110 is composed of a plate-shaped frame extending in a direction orthogonal to the transport direction of the sheet-shaped body P. Both ends of the plate-shaped frame are bent upward at right angles to form a pair of left and right side plate portions 111.

Bearings 114 and 115 are fixed side by side to the side plate 111. On one side of the lower surface of the rotating body pair holding member 110, a rotating receiver 110b extending at a predetermined length in a direction orthogonal to the transport direction of the sheet-shaped body P is integrally formed perpendicularly to the lower surface of the rotating body pair holding member 110. Has been done.

A support shaft 110a as a guided portion that projects downward shortly is fixed to the lower surface of one side of the rotating body pair holding member 110. A guide roller 136 is rotatably mounted on the lower end of the support shaft 110a, and a cam follower 135 is rotatably mounted on the intermediate portion of the support shaft 110a.

The first motor 120, the second motor 130, and the rotary encoders 128 and 138 are arranged side by side in the left-right direction on the lower horizontal plate 153. On the other hand, the first motor 120 is for skew compensation, and the drive pulley 121 is fixed to the rotating shaft thereof. The other second motor 130 is for lateral displacement correction, and another drive pulley 131 is fixed to the rotating shaft thereof.

Instead of one of the rotary encoders 128, an arbitrary encoder or sensor that detects the movement and position of the first rotation cam 124 or the lever member 125, which will be described later, may be provided. Further, instead of the other rotary encoder 138, an arbitrary encoder or sensor that detects the movement and position of the second rotating cam 134 or the rotating body pair holding member 110, which will be described later, may be provided.

The driven pulleys 122 and 132 are rotatably supported between the upper and lower horizontal plates 153 and 154. The upper and lower ends of the rotating shafts 122a and 132a of the driven pulleys 122 and 132 are rotatably supported by the upper and lower horizontal plates 153 and 154, respectively. The rotation axes 122a and 132a are parallel to each other. Then, timing belts 123 and 133 are bridged between the drive pulleys 121 and 131 and the driven pulleys 122 and 132, respectively.

The rotating plates 128a and 138a, which are the rotating side components of the rotary encoders 128 and 138, are fixed to the rotating shafts 122a and 132a of the driven pulleys 122 and 132 protruding downward from the lower horizontal plate 153. A plurality of slits are continuously formed on the peripheral edge portion of the rotating plates 128a and 138a, and a light emitting / receiving device which is a fixed side component of the rotary encoder 128a and 138 is arranged so as to sandwich the peripheral edge portion vertically.

The first rotating cam 124 and the second rotating cam 134 are fixed to the upper ends of the rotating shafts 122a and 132a of the driven pulleys 122 and 132 protruding upward from the upper horizontal plate 154. The cam curves of the first rotating cam 124 and the second rotating cam 134 are formed so as to be constant velocity cam curves, respectively. By using the constant velocity cam, the rotation angle of the first rotation cam 124 and the second rotation cam 134 and the linear movement distance of the cam followers 126 and 135 described later become proportional to each other, and the shift position control of the support shaft 110a is performed. And the rotation control of the lever member 125 becomes easy.

An elongated hole 154a as a guide portion extending in a direction orthogonal to the sheet-like body transport direction is formed in the upper horizontal plate 154 at a position adjacent to the second rotation cam 134 on one side. A guide roller 136 at the lower end of the support shaft 110a is inserted into the elongated hole 154a. The cam follower 135 at the intermediate portion of the support shaft 110a is in contact with the cam surface at the peripheral edge of the second rotating cam 134 by the force of the tension spring 113. The elongated hole 154a is for guiding the guide roller 136 in a straight line, and the elongated hole can be used instead of the elongated hole.

A fulcrum shaft 154b is projected on a horizontal plate 154 on the opposite side of the second rotation cam 134, and a lever member 125 is rotatably arranged on the fulcrum shaft 154b in the horizontal direction. The cam follower 126 and the acting roller 127 as the first pressing portion are rotatably mounted on the support shafts 125a and 125b integrally formed on both ends of the lever member 125 via an arbitrary bearing material such as a ball bearing. There is. The outer peripheral surface of the cam follower 126 is in contact with the outer peripheral surface of the first rotating cam 124 by the spring force of the first tension spring 112. The outer peripheral surface of the working roller 127 is in contact with the rotation receiver 110b by the spring force of the first tension spring 112.

That is, the first drive means is composed of the first motor 120 for skew correction, the drive pulley 121, the timing belt 123, the driven pulley 122, the first rotation cam 124, the lever member 125, and the action roller 127. The first driving means moves the working roller 127 as the first pressing portion back and forth in the direction of the transport path of the sheet-shaped body P.

Further, the second drive means is composed of the second motor 130 for correcting the lateral displacement, the drive pulley 131, the timing belt 133, the driven pulley 132, and the second rotation cam 134. This second driving means has a second pressing portion (cam outer peripheral surface) that abuts on the support shaft 110a as a guided portion via the cam follower 135, and the support shaft 110a is orthogonal to the transport path of the sheet-shaped body P. Moves left and right in the direction of

A bracket 155 is vertically arranged on one side of the main body frame 151 of the straight transport path K2 and on one end side in the axial direction of the resist rotating body pair 33. A variable rotation speed roller drive motor 140 for rotationally driving the downstream rotating member 33b1 of the resist rotating body pair 33 is fixed to the outer surface of the bracket 155. The rotating shaft of the roller drive motor 140 projects horizontally toward the inside of the bracket 155, and the pinion 141 is fixed to the rotating shaft protruding inward. The pinion 141 is meshed with a reduction gear 142 pivotally supported inside the bracket 155.

The rotating shaft 142a of the reduction gear 142 is connected to the rotating shaft 61b of the downstream rotating member 33b1 of the resist rotating body pair 33 via a two-stage spline coupling 143. As a result, the rotational driving force of the roller drive motor 140 is transmitted to the downstream rotating member 33b1 via the pinion 141, the reduction gear 142, and the two-stage spline coupling 143, and the resist rotating body pair 33 is rotationally driven. Therefore, the sheet-shaped body P can be transported at an arbitrary transport speed by rotating the downstream rotating member 33b1 with the roller drive motor 140 while the resist rotating body pair 33 sandwiches the sheet-shaped body P.

The two-stage spline coupling 143 is a kind of constant velocity universal joint, and as shown in the partially enlarged view of FIG. 4A, the first spline gear 143a, the second spline gear 143b, the intermediate spline gear 143c, the guide ring 143d, etc. It is configured.

The first spline gear 143a is an external gear and is installed on a rotating shaft 142a that rotates together with the reduction gear 142 of the first driving means. The rotating shaft 142a is rotatably held by the bracket 155 via a bearing.

The second spline gear 143b is also an external gear and is connected to the rotating shaft 61b of the downstream rotating member 33b1 of the resist rotating body pair 33. The intermediate spline gear 143c is an internal gear, and extends in the width direction so that the resist rotating body pair 33 (rotating body pair holding member 110) always meshes with the two spline gears 143a and 143b even if they move in the width direction. Has been done. Further, the two spline gears 143a and 143b are formed in a crown shape so as to mesh with the intermediate spline gear 143c even if the resist rotating body pair 33 (rotating body pair holding member 110) rotates in an oblique direction.

By using such a two-stage spline coupling 143, the resist rotating body pair 33 is satisfactorily rotationally driven. That is, even if the resist rotating body pair 33 rotates about the support shaft 110a in the substantially horizontal plane direction or slides in the width direction, the driving force of the roller drive motor 140 on the fixed side is the resist rotating body. It is accurately and reliably transmitted to the downstream rotating member 33b1 of the pair 33.

The guide ring 143d is a substantially annular stopper member installed at both ends of the intermediate spline gear 143c in the width direction, and the two spline gears 143a and 143b move relatively in the width direction to form a two-stage spline cup. Prevents it from falling off the ring 143.

The skew detection sensors 145 (photosensors 145a and 145b) and CIS146 have the upper guide plate 41 of the linear transport path K2 between the transport roller pair 31 and the resist rotating body pair 33, as shown in FIGS. 3A (a) and 3A (b). It is attached to. The CIS146 is a rod-shaped array of light sources such as LEDs, light receiving lenses, and CMOS image sensors, and detects the position of the edge portion of the sheet-shaped body P on one end side in the width direction to determine the amount of lateral displacement of the sheet-shaped body P. Detect.

The skew detection sensor 145 is composed of a pair of photosensors 145a and 145b, and the pair of photosensors 145a and 145b are symmetrically arranged at positions equidistant from the center position in the width direction of the linear transport path K2. .. Then, the skew angle of the sheet-shaped body P is detected by detecting the front end edges of the sheet-shaped body P in time with each other by a pair of photo sensors 145a and 145b. The positions of the CIS 146 and the skew detection sensor 145 can both be changed between the transfer roller pair 31 and the resist rotating body pair 33.

The three motors 120, 130, 140, the three rotary encoders 128, 138, 144, the skew detection sensor 145, and the CIS 146 described above are connected to the control unit 160 as shown in FIG. 4A. Then, the detection signals of the rotary encoders 128, 138, 144, the skew detection sensors 145 (145a, 145b) and the CIS146 are input to the control unit 160, and the control unit 160 is based on the detection signals as shown in the flowchart of FIG. The three motors 120, 130, and 140 are driven and controlled.

The control unit 160 has a controller 161 and a motor driver 162 as shown in FIG. 4C, and signals of the sensors 145a, 145b, 146 and the arithmetic circuit 159 are input to the controller 161. Further, drive signals are output from the motor driver 162 to the six motors 120, 130, 140, 156 to 158.

(Resist rotating body pair)
As shown in FIGS. 3B (a) to 3 (c), the resist rotating body pair 33 is composed of an upper rotating body 33a and a lower rotating body 33b. The upper and lower rotating bodies 33a and 33b are vertically separated from the downstream rotating members 33a1 and 33b1 forming the nip portion and the downstream rotating members 33a1 and 33b1 on the upstream side of the straight transport path K2. It has an arranged upstream rotating member pair 33a2 and 33b2.

The downstream rotating members pairs 33a1 and 33b1 and the upstream rotating members pairs 33a2 and 33b2 are cylindrical bodies having the same or substantially the same diameter, and in the present embodiment, they are composed of dividing rollers divided into four in the axial direction. It is also possible to configure the upper and lower rotating members with one roller that is continuous in the axial direction, but this increases the weight of the rotating members.

By forming the rotating member with a split roller, the total weight of the rotating body vs. holding member 110 can be reduced, and high-speed transport and high-speed correction (high-speed skew correction and high-speed shift correction) of the sheet-like body P can be supported. it can. Of course, the number of dividing rollers is not limited to four, and may be at least two or more, and may be an even number or an odd number.

Further, between the downstream rotating members pairs 33a1 and 33b1 and the upstream rotating members pairs 33a2 and 33b2, a flat belt pair as an endless orbiting member pair that tapers from the nip portion toward the upstream side of the linear transport path K2. 33a3 and 33b3 are hung, respectively. The tapered angle of the flat belt pairs 33a3 and 33b3 is preferably an acute angle of less than 90 degrees, for example, an acute angle of 10 degrees or more and less than 30 degrees, and in the illustrated example, it is an acute angle of about 20 degrees.

In FIG. 3B, the endless orbiting member pair is composed of flat belt pairs 33a3 and 33b3. The endless circuit member pair is not limited to the flat belt pair 33a3 and 33b3, and the round belt pair 33a4 and 33b4 are used in the first modification described later in FIG. 10A. The types of belts are not limited to flat belts and round belts, and V-belts and belts of other shapes can be used as well.

In the present embodiment, the tip portion of the sheet-like body P is guided by the flat belt pairs 33a3 and 33b3 as a pair of endless rotating members that taper from the nip portion toward the upstream side, and is guided to the downstream side without fluttering. It is introduced into the nip portion between the rotating member pair 33a1 and 33b1. That is, the space between the flat belts 33a3 and 33b3 is uniformly narrowed in the width direction as it approaches the nip portion. Therefore, even if the tip of the sheet-like body P conveyed from the upstream side flutters between the upper and lower guide plates 41 and 42, the tip is uniformly tapered in the width direction until the tip reaches the nip. Fluttering is suppressed by the flat belt pairs 33a3 and 33b3.

Further, in the fixed guide plate, a certain minimum gap is required between the guide plates in order to suppress the occurrence of jam. However, in the case of the flat belt pairs 33a3 and 33b3, the sheet-like body P can be reliably guided to the nip portion by arranging the belts at a small angle with respect to the transport direction.

Further, the downstream ends of the endless rotating members pairs 33a3 and 33b3 are wound around the peripheral surfaces of the downstream rotating members pairs 33a1 and 33b1. Therefore, the sheet-like body P does not hit the peripheral surfaces of the downstream rotating members 33a1 and 33b1 in front of the nip portion while being fluttered on the upstream side of the nip portion. Therefore, unlike the conventional case, skew due to fluttering of the sheet-like body P does not occur.

Moreover, since the flat belt pairs 33a3 and 33b3 rotate in synchronization with each other due to frictional force and orbit at the same speed as the transport speed of the sheet-shaped body P, the impact when the sheet-shaped body P hits the belt is fixed. It is much smaller than the impact when it hits the guide plate. Therefore, it is possible to suppress the occurrence of skew due to the abutment of the sheet-like body P against the belt.

Guide plates 41 and 42, which will be described later, are arranged between the upper rotating body 33a and the lower rotating body 33b in order to stably convey the sheet-shaped body P. The guide plates 41 and 42 have a first notch hole 41b and a second notch hole 42b corresponding to the positions of the downstream rotating members pairs 33a1 and 33b1 divided into four, and the guide plates 41 and 42 are spaced between the divided rollers. By filling with, the sheet-like body P is stably conveyed.

However, the guide plates 41 and 42 are not always essential in this embodiment. That is, it is possible to effectively suppress the fluttering of the sheet-like body P by appropriately selecting the tapered angles of the flat belt pairs 33a3 and 33b3 without the guide plates 41 and 42.

The downstream rotating member 33b1 and the upstream rotating member 33b2 arranged in the lower stage are supported by rotating shafts 61b and 62b rotatably supported at both ends by a pair of left and right side plate portions 111 of the holding member 110. Both ends of the rotating shaft 61b of the downstream rotating member 33b1 are rotatably supported by the bearing 115 of the side plate portion 111. One end of the rotating shaft 61b is connected to a variable rotation speed roller drive motor 140 fixedly arranged on the main body frame 151 so as to be separated from the side of the rotating body pair holding member 110. The connection structure to the motor 140 will be described later.

The downstream rotating member 33a1 and the upstream rotating member 33a2 arranged in the upper stage are supported by rotating shafts 61a and 62a whose both ends are rotatably supported by a pair of left and right side plate portions 111 of the holding member 110. The three rotating shafts 61a, 62a, and 62b other than the lower rotating shaft 61b are free rotating shafts (driven rotating shafts) to which the motor is not connected.

The rotary encoder 144 is mounted on the rotating shaft 61b of the downstream rotating member 33b1 protruding outward from the lower bearing 115. The variable rotation speed roller drive motor 140 is driven based on the rotation speed of the downstream rotating member 33b1 or the lower rotating body 33b detected by the rotary encoder 144. Then, the downstream rotating member 33a1 or the upper rotating body 33a is adapted to rotate in accordance with the rotation of the lower rotating body 33b.

An L-shaped lever 57 is arranged on the outer surface of the side plate portion 111 as shown in FIGS. 3B (a) and 3B (b). The central right-angled portion of the L-shaped lever 57 is rotatably supported at the end of the rotating shaft 62a. A rotation shaft 61a is supported at the tip of one arm of the L-shaped lever 57.

An arcuate elongated hole 111a extending in the vertical direction is formed in the side plate portion 111, and a rotating shaft 61a supported by the tip of one arm of the L-shaped lever 57 is inserted into the elongated hole 111a so as to be vertically movable. Has been done. A tension spring 58 is connected to the tip of the other arm of the L-shaped lever 57, and the tension spring 58 urges the L-shaped lever 57 to rotate counterclockwise in FIGS. 3B (a) and 3B (b). ..

Both ends of the rotary shaft 61a are connected to a cam driven by a contact / detachment motor 157 (see FIG. 4C), and when the nip portion is opened, the cam is driven by the contact / detachment motor 157 and the rotary shaft 61a opposes the tension spring 58. Rise. Further, when the sheet-like body P is sandwiched between the nip portions, the cam is driven in the opposite direction by the contact / detachment motor 157, and the nip portion is closed by the force of the tension spring 58.

Guide plates 41 and 42 are vertically opposed to each other between the upper rotating body 33a and the lower rotating body 33b. The upper guide plate 41 is the first guide plate, and the lower guide plate 42 is the second guide plate. The guide plates 41 and 42 are arranged in parallel in the horizontal direction with a predetermined interval through which the sheet-like body P can pass. The upstream ends of the guide plates 41 and 42 form inlet portions 41a and 42a that taper toward the upstream side in order to receive the sheet-like body P.

The first notch hole 41b and the second notch hole 42b are formed downstream of the inlet portions 41a and 42a of the guide plates 41 and 42 by a predetermined distance. The notch holes 41b and 42b are formed in a rectangular shape corresponding to the positions of the downstream rotating member pairs 33a1 and 33b1. The width direction of the notch holes 41b and 42b is formed to be slightly larger than the axial length of the downstream rotating members vs. 33a1 and 33b1. The lengths of the cutout holes 41b and 42b in the transport direction are formed inside the cutout holes 41b and 42b so as to be able to accept the downstream ends of the endless peripheral member pairs 33a3 and 33b3 with a predetermined length.

The guide plates 41 and 42 can be integrally arranged on the rotating body pair holding member 110 to form a unit, which facilitates assembly and reduces costs. Alternatively, the guide plates 41 and 42 may be fixedly arranged on the base frame 152 separately from the rotating body pair holding member 110.

As a result, the weight of the rotating body pair holding member 110 can be reduced, and high-speed transfer and high-speed correction (high-speed skew correction and high-speed shift correction) of the sheet-like body P can be supported. When the guide plates 41 and 42 are fixedly arranged in this way, the size of the notch holes 41b and 42b is formed to be large so as not to interfere with the resist rotating body pair 33 that operates the picking operation and the returning operation. ..

(Skew correction operation and lateral displacement correction operation of rotating body vs. holding member)
5 (a) to 5 (d) are views showing the operations of the skew correction and the lateral deviation correction separately in order to clearly show the operations of the skew correction and the lateral deviation correction of the sheet-like body P described above. In reality, it is rare that only the lateral displacement correction operation of FIG. 5B or the skew correction operation of FIG. 5C occurs, and normally, the skew correction operation and the lateral displacement correction operation are performed as shown in FIG. 5D. It becomes a combined form.

FIGS. 5 (a) to 5 (b) show the lateral displacement correction operation of the sheet-like body P. That is, when the second motor 130 is driven and the second cam 134 is rotated, the rotating body pair holding member 110 slides to the right side so as to resist the spring force of the second tension spring 113 by the second cam 134. ..

At this time, since the action roller 127 of the lever member 125 rolls on the surface of the rotation receiver 110b while receiving the force of the first tension spring 112, the sliding movement of the rotating body vs. the holding member 110 is smooth. In the state where the first cam 124 is stopped, the rotation receiver 110b also remains stopped in the sheet-like body transport direction, so that the skew correction operation of the sheet-like body P does not occur.

FIGS. 5 (a) to 5 (c) show the skew correction operation of the sheet-like body P. That is, when the first motor 120 is driven and the first cam 124 is rotated, the lever member 125 is pushed by the first cam 124 and rotates counterclockwise around the fulcrum shaft 154b.

As a result, the rotating body pair holding member 110 is pushed by the acting roller 127 of the lever member 125 at the position of the rotating body pair holding member 110b, and the rotating body pair holding member 110 is at the right end so as to resist the spring force of the first tension spring 112. Rotates counterclockwise around the support shaft 110a of. At this time, since the cam follower 135 moves on the outer circumference of the second rotating cam 134 while rotating, the rotating load of the rotating body pair holding member 110 acting on the first motor 120 for skew correction can be small.

FIGS. 5A → 5D show a combination of the lateral displacement correction operation and the skew correction operation of the sheet-like body P. That is, when the first motor 120 is driven to rotate the first cam 124 and the second motor 130 is driven to rotate the second cam 134, the lateral displacement correction operation (b) described above (b) An operation in which the skew correction operation of c) is combined occurs.

As described above, in the present embodiment, the resist rotating body pair 33 is held by the rotating body pair holding member 110 which is movable in the width direction of the linear transport path K2 and is rotatable about the support shaft 110a. The rotational driving force of the roller drive motor 140 on the fixed side is transmitted to the resist rotating body pair 33 via the two-stage spline coupling 143. Therefore, the roller drive motor 140 and the second motor 130 for lateral displacement correction can be arranged on the fixed side, and the responsiveness of skew correction can be improved by reducing the weight of the structure above the rotating body pair holding member 110.

In the lateral displacement correction and skew correction described above, 1) the skew angle of the sheet-like body P is θ, and 2) the lateral displacement correction amount is Δy, as shown in FIG. 3) The distance between the paper lateral register reference (initial position of the support shaft 110a which is the guided portion) and the center of the support shaft 125b of the acting roller 127 as the first pressing portion of the first driving means is d. And. In FIG. 6, the Δy is brass on the right side and negative on the left side based on the paper horizontal register standard.

In this case, when the back-and-forth movement distance of the rotation receiving portion 110b that moves back and forth by the action roller 127 is Δx, the skew as the first driving means by the control unit 160 is based on the result calculated by the following mathematical formula (1). The first motor 120 for correction is controlled.
Δx = (d + Δy) tan θ… (1)

The reason for multiplying tan θ by (d + Δy) instead of simply multiplying it by d when calculating Δx in the above equation (1) is as follows. That is, as described above, it is rare that only the lateral displacement correction operation of FIG. 5 (b) or the skew correction operation of FIG. 5 (c) occurs, and usually the skew correction operation is performed as shown in FIG. 5 (d). It is a combination of lateral displacement correction operations.

Therefore, if the rotating body pair holding member 110 is rotated (picked up) by Δx calculated by the mathematical formula (2) described later, ignoring the Δy, the picking up operation becomes too large or too small. That is, a skew correction error is generated due to the lateral deviation correction.

For example, as shown in FIG. 6, when the support shaft 110a moves to the right by Δy for lateral deviation correction, the first motor 120 for skew correction is driven without considering this movement, and the rotation receiving portion 110b is moved by Δx. When moving, the skew angle cannot be corrected. That is, since the control unit 160 calculates Δx by the following mathematical formula (2), the skew angle cannot be corrected by the equal amount of return operation amount at the time of recovery as a result of the pick-up operation amount being too small.
Δx = d · tan θ… (2)

On the contrary, considering the case where the support shaft 110a moves to the opposite side (that is, the left side) by Δy for lateral deviation correction in FIG. 6, the first motor 120 for skew correction is driven without considering this movement. If the rotation receiving portion 110b is moved by Δx, the skew angle is overcorrected this time. That is, as a result of the pick-up operation amount being too large, the equal amount of return operation amount at the time of recovery is too large and the skew angle is corrected too much.

7A and 7B show in FIG. 6 that the skew angle is overcorrected when the support shaft 110a moves to the left by Δy for lateral deviation correction. After welcoming and operating at an angle θ2 as shown in FIG. 7A (a), the sheet-shaped body P is sandwiched and returned as shown in FIG. 7B (a), so that the front end edge of the sheet-shaped body P is (θ2-θ1). ) Only skews. For the above reasons, in the embodiment of the present invention, the first motor 120 for skew correction is controlled based on the result calculated by the mathematical formula (1).

(flowchart)
Next, the above-mentioned operation will be described with reference to the flowchart of FIG. In step S1, the second motor 130 for lateral displacement correction, the first motor 120 for skew correction, and the roller drive motor 140 are all turned on. Then, in step S2, the posture (lateral deviation direction, rotation direction) of the resist rotating body pair 33 is initialized (the rotating body pair holding member 110 returns to the initial position).

In step S3, the skew angle and the amount of lateral deviation of the sheet-like body P are detected by the skew detection sensor 145 and CIS146, and in step S4, the presence or absence of skew or lateral deviation is determined. If there is no skew and lateral deviation, the flow ends. If there is skew or lateral displacement, the drive amount of the second motor 130 for lateral displacement correction (required rotation amount of the second rotation cam 134) is calculated in step S5, and the first motor for skew correction is calculated in step S6. The drive amount of 120 (the required rotation amount of the first rotation cam 124) is calculated. The calculation is completed by the time the front edge of the sheet-like body P reaches the resist rotating body pair 33 as shown in FIG. 9C.

Next, in step S7, the second motor 130 for lateral displacement correction and the first motor 120 for skew correction are picked up (driving corresponding to (a) in FIG. 9C), and in step S8, the sheet-like body P is moved. It is sandwiched by the resist rotating body pair 33 (Fig. 9D). While transporting the sheet-shaped body P in this state, the second motor 130 for lateral displacement correction and the first motor 120 for skew correction are returned and operated in step S9 to correct the lateral displacement and skew of the sheet-shaped body P. To do. After that, by repeating the same operation as described above, the sheet-like body P in which the skew and the lateral displacement are corrected with high accuracy is delivered from the straight transport path K2.

(Correcting lateral displacement and skew compensation during transportation of sheet-like body)
Next, with reference to FIGS. 9A to 9G, an operation of correcting the lateral displacement and performing skew compensation while transporting the sheet-shaped body P by the transport roller pair 31 and the resist rotating body pair 33 will be described. FIG. 9A (a) shows a state in which the sheet-like body P reaches one of the two skew detection sensors 145 (photo sensor 145a) in the skew state.

The sheet-like body P indicated by the alternate long and short dash line is the regular reference position without skew and lateral deviation. The sheet-like body P shown by a solid line with respect to this reference position is skewed counterclockwise by an angle β. The front edge of the sheet-like body P is detected by a pair of skew detection sensors 145 (photosensors 145a and 145b) in chronological order. As a result, the skew state (angle β) is detected based on the time difference and the relative distance between the two skew detection sensors 145 (photosensors 145a and 145b). The skew angle β is calculated by the control unit 160.

On the other hand, FIG. 9A (b) shows a state in which the sheet-like body P reaches the skew detection sensors 145 (photosensors 145a and 145b) in a laterally displaced state without skewing. The sheet-like body P indicated by the alternate long and short dash line is the regular reference position without skew and lateral deviation.

The sheet-like body P shown by the solid line with respect to this reference position is laterally displaced upward (on the right side in the transport direction) by the amount of lateral displacement α. The lateral displacement amount α is detected by detecting the right edge of the sheet-like body P by CIS146.

Further, the lateral displacement amount in the skew state of FIG. 9A (a) described above is calculated as the lateral displacement amount α when there is no skew by combining the detection results of the skew detection sensor 145 (photo sensor 145a) and CIS146. To. The lateral deviation amount α is calculated by the control unit 160.

When the skew angle and the amount of lateral displacement of the skewed and laterally displaced sheet-shaped body P are detected, the sheet-shaped body P is conveyed to the downstream side as it is by the transfer roller pair 31 as shown in FIG. 9B. Then, as shown in FIG. 9C, when the front end edge of the sheet-shaped body P approaches the resist rotating body pair 33, the resist rotating body pair 33 is indicated by two arrows based on the detection results of the skew detection sensor 145 and CIS146. It operates from the initial position for skew correction and lateral displacement correction. The timing of this pick-up operation is calculated by the control unit 160.

The movement amount of this pick-up operation is the movement amount corresponding to the skew angle β and the lateral deviation amount α from the reference position in FIGS. 9A (a) and 9A (b) described above. As a result of this pick-up operation, the axial direction of the nip portion of the resist rotating body pair 33 and the front end edge of the sheet-shaped body P become parallel, and the central portion in the axial direction of the nip portion and the central portion in the width direction of the sheet-shaped body P Matches. In this state, as shown in FIG. 9D, the front end portion of the sheet-shaped body P is sandwiched between the nip portions of the resist rotating body pair 33.

When the front end portion of the sheet-shaped body P is sandwiched between the nip portions of the resist rotating body pair 33, the driven roller 31a of the transport roller pair 31 moves upward apart as shown in FIG. 9D (b), and the sheet-shaped body P moves upward. Open the upstream end. After that, as shown in FIG. 9E (a), the resist rotating body pair 33 rotates about the support shaft 110a so as to cancel the skew angle β while sandwiching and transporting the sheet-shaped body P, and the amount of lateral displacement. It moves in the width direction so as to cancel α.

In this way, the sheet-like body P is skew-corrected and laterally displaced at the same time while being conveyed. Further, the timing at which the front end edge of the sheet-like body P reaches the secondary transfer nip of the secondary transfer roller 19 is adjusted by the rotation speed of the resist rotating body pair 33.

When the trailing edge of the sheet-shaped body P passes through the transport roller pair 31 as shown in FIG. 9F, the nip portion of the transport roller pair 31 closes as before to prepare for the subsequent transport of the other sheet-shaped body P. Then, when the front end edge of the sheet-like body P reaches the secondary transfer nip of the secondary transfer roller 19 as shown in FIG. 9G, the sheet-like body P is conveyed by the secondary transfer nip and at a desired position on the sheet-like body P. The image is transferred to.

The resist rotating body pair 33 is transferred to the image on the sheet-like body P due to a linear velocity difference with the intermediate transfer belt 8 immediately after the front end edge of the sheet-like body P reaches the image forming portion. The transport speed is adjusted so that distortion does not occur.

(Modification example of a pair of rotating bodies)
Next, three modified examples of the resist rotating body pair 33 will be described.
(First modification)
FIG. 10A shows a sheet-like body transfer device 150 provided with a first modification of the resist rotating body pair 33, (a) is a perspective view in which the guide plates 41 and 42 are omitted, and (b) is a guide plate 41. A perspective view including 42, (c) is a cross-sectional view taken along the line cc of (b). In the above embodiment, as shown in FIG. 3B, the endless orbiting member pair of the rotating body pair is composed of the flat belt pairs 33a3 and 33b3, but in FIG. 10A, the endless orbiting member pair is composed of the round belt pairs 33a4 and 33b4. The effect of suppressing fluttering of the sheet-like body is the same for the flat belts 33a3 and 33b3 and the round belts 33a4 and 33b4, but the round belts 33a4 and 33b4 are more weight-reducing and cost-reducing than the flat belts 33a3 and 33b3. It is advantageous.

The downstream and upstream ends of the round belt pairs 33a4 and 33b4 are fitted into the annular grooves 40 formed at both ends in the axial direction of the downstream rotating members pairs 33a1 and 33b1 and the upstream rotating members pairs 33a2 and 33b2. There is. As a result, the displacement and dropout of the round belts 33a4 and 33b4 in the width direction are regulated. The diameters of the round belt pairs 33a4 and 33b4 are set to the same sizes as the peripheral surfaces of the downstream rotating members pairs 33a1 and 33b1 and the upstream rotating members pairs 33a2 and 33b2 while being fitted in the annular groove 40. ..

Also in this first modification, the tip portion of the sheet-like body is guided by the round belt pairs 33a4 and 33b4 that taper from the nip portion toward the upstream side as in the above embodiment, and is downstream without fluttering. It is introduced into the nip portion between the side rotating member pairs 33a1 and 33b1. The nip portion is formed by mutual direct contact between the downstream rotating members pairs 33a1 and 33b1 and mutual contact between the round belt pairs 33a4 and 33b4.

(Second modification)
10B shows a second modified example of the pair of rotating bodies, (a) is a perspective view including a guide plate, and (b) is a sectional view taken along line bb of (a). In the above embodiment, the endless circuit member pair is composed of flat belt pairs 33a3 and 33b3, but in FIG. 10B, the flat belt 33a3 is arranged on the upper side and the downstream rotating member 33b1 without the flat belt is arranged on the lower side. Is. By simplifying the configuration, the effects of weight reduction and cost reduction can be obtained.

In this second modification, the lower guide plate 42 is arranged so that the height of the upper surface of the lower guide plate 42 matches the height of the peripheral surface of the downstream rotating member 33b1. The downstream end of the upper flat belt 33a3 directly abuts on the peripheral surface of the downstream rotating member 33b1, and a nip portion for sandwiching the sheet-like body is formed in the abutting portion. Therefore, the heights of the upper surface of the nip portion and the lower guide plate 42 are the same.

The space between the flat belt 33a3 and the lower guide plate 42 becomes narrower as it approaches the nip portion. Therefore, even if the sheet-like body conveyed from the upstream side is fluttering on the lower guide plate 42, the flat belt 33a3 and the lower guide plate 42 suppress the fluttering by the time it reaches the nip portion. .. Further, since the height of the peripheral surface of the downstream rotating member 33b1 matches the height of the upper surface of the lower guide plate 42, the sheet-like body remains fluttering on the upstream side of the nip portion and is in front of the nip portion. It does not hit the peripheral surface of the downstream rotating member 33b1.

Therefore, the conventional skew due to the fluttering of the sheet-like body does not occur. As described above, in this second modification, unlike the above-described embodiment, at least the lower guide plate 42 is indispensable.

(Third modification example)
10C shows a third modification of the pair of rotating bodies, (a) is a perspective view including a guide plate, and (b) is a sectional view taken along line bb of (a). In the first modification of FIG. 10A, the endless peripheral member pair is composed of the round belt pairs 33a4 and 33b4, but in FIG. 10C, the round belt 33a4 is arranged on the upper side and the downstream rotating member 33b1 without the round belt is arranged on the lower side. It is a configuration that is just placed. By simplifying the configuration, the effects of weight reduction and cost reduction can be obtained.

In this third modification, the lower guide plate 42 is arranged so that the height of the upper surface of the lower guide plate 42 matches the height of the peripheral surface of the downstream rotating member 33b1. The downstream end of the upper round belt 33a4 directly abuts on the peripheral surface of the downstream rotating member 33b1, and a nip portion for sandwiching the sheet-like body is formed in the abutting portion. Therefore, the heights of the upper surface of the nip portion and the lower guide plate 42 are the same.

The distance between the round belt 33a4 and the lower guide plate 42 becomes narrower as it approaches the nip portion. Therefore, even if the sheet-like body conveyed from the upstream side is fluttering on the lower guide plate 42, the fluttering is suppressed by the round belt 33a4 and the lower guide plate 42 by the time it reaches the nip portion. .. Further, since the height of the peripheral surface of the downstream rotating member 33b1 matches the height of the upper surface of the lower guide plate 42, the sheet-like body remains fluttering on the upstream side of the nip portion and is in front of the nip portion. It does not hit the peripheral surface of the downstream rotating member 33b1. Therefore, unlike the conventional case, skew due to fluttering of the sheet-like body does not occur.

(Modification example of skew detection sensor)
11A and 11B show a modification of the skew detection sensor, in which the second CIS 147 is arranged in parallel with the first CIS 146 on the downstream side of the first CIS 146. The lateral displacement amount and skew angle of the sheet-like body P are detected by two CIS 146s and 147 parallel to each other. By arranging two CIS with the same configuration, the cost can be reduced by reducing the number of parts.

In the pick-up operation of the resist rotating body pair 33, the skew correction th is such that the extension line of the side edge of the sheet-like body P detected by the two CIS 146 and 147 and the axial direction of the resist rotating body pair 33 are orthogonal to each other. One motor 120 greets and operates. Further, from the detection results of the two CIS 146s and 147, the lateral deviation amount of the sheet-like body P when there is no inclination of the side edge of the sheet-like body P is calculated by the control unit 160, and the lateral deviation corresponds to the lateral deviation amount. The second motor 130 for correction is greeted and operated.

(Modification example of the position of the support shaft of the rotating body vs. holding member)
FIG. 12 shows an example of modification of the position of the support shaft 110a of the rotating body vs. holding member 110 of the sheet-like body conveying device. That is, in the above-described embodiment, the position of the two-stage spline coupling 143 and the position of the support shaft 110a of the rotating body pair holding member 110 are set to positions separated from each other in the axial direction of the resist rotating body pair 33.

This is to make the base frame 152 as compact as possible, but it is improved in order to smoothly transmit the rotational driving force from the two-stage spline coupling 143 to the downstream rotating member 33b1 of the resist rotating body pair 33. There is room. That is, in the above-described embodiment, when the rotating body pair holding member 110 is rotated about the support shaft 110a, a so-called “argument” occurs in the two-stage spline coupling 143.

Therefore, in order to avoid the occurrence of the "argument", as shown in FIG. 12, the center position of the left-right movement of the support shaft 110a of the rotating body vs. holding member 110 (paper lateral cash register reference) is moved to the right side, and this moving position is moved. The central portion of the two-stage spline coupling 143 was arranged so as to match the above. In this configuration, since the position of the support shaft 110a moves outward in the width direction of the straight transport path K2, the width of the base frame 152 is slightly larger than that in FIG. 4A, but the resist rotating body vs. 33 downstream rotating member 33b1 There is an advantage that the rotational driving force can be transmitted accurately.

Although the embodiment of the present invention has been described above, the present invention can be applied to all sheet-like body transfer devices that perform skew correction and lateral deviation correction. For example, the present invention can be applied to a transfer device in which a timing roller pair is installed on the downstream side of a resist rotating body pair 33 that functions as a horizontal resist / skew correction roller.

Further, the present invention can be applied not only to a transport device for transporting transfer paper or paper as a sheet-like body, but also to a transport device for transporting a document as a sheet-like body. Further, the sheet-like body transfer device of the present invention can be applied to other types of image forming devices (for example, an inkjet type image forming device, an offset printing machine, etc.).

31: Conveying roller pair 33: Resist rotating body pair 33a: Upper rotating body 33a1: Downstream rotating member 33a2: Upstream rotating member 33a3: Flat belt 33b: Lower rotating body 33b1: Downstream rotating member 33b2: Upstream rotating member 33b3: Flat belt 33a4, 33b4: Round belt 41: Upper guide plate (first guide plate)
41a: Inlet 41b: First notch hole 42: Lower guide plate (second guide plate) 42a: Inlet 42b: Second notch hole 57: L-shaped lever 100: Image forming device 110: Rotating body vs. holding member 110a: Support shaft (guided part) 110b: Rotating receiving part 111: Side plate part 118: Free bearing 112: First tension spring 113: Second tension spring 120: Rotating cam motor (first driving means) 121: Drive pulley 122: Driven pulley 123: Timing belt 124: First rotation cam 125: Lever member 126: Cam follower 127: Action roller (first pressing part)
128: 138: Rotary encoder 128a, 138a: Rotating plate 130: Shift cam motor (second driving means) 131: Drive pulley 132: Driven pulley 133: Timing belt 134: Second rotating cam (second pressing part) 135: Cam follower 136: Guide roller 140: Resist drive motor 141: Pinion 142: Reduction gear 142a: Rotating shaft 143: Two-stage spline coupling 144: Rotary encoder 145: Skew detection sensor 146: Lateral displacement detection sensor 150: Sheet-like body transfer device 151 : Body frame 152: Base frame 153, 154: Horizontal plate 154a: Long hole (guide part)
154b: Supporting shaft 160: Control unit K1: Paper feed path K2: Straight transfer path K3: Straight transfer path

Japanese Unexamined Patent Publication No. 9-175649

Claims (9)

A pair of rotating bodies that sandwich and transport the sheet-like body supplied to the transport path, and a pair of rotating bodies that hold the pair of rotating bodies and rotate along a transport surface including a nip portion of the pair of rotating bodies that sandwich the sheet-like body. It has a rotating body pair holding member that is capable and can be shifted and moved in the width direction of the transport path, and moves the rotating body pair to a facing position corresponding to the posture of the sheet-like body that is about to enter the nip portion. The rotating body pair is operated so as to receive the rotating body pair, and the rotating body pair is moved from the facing position to a predetermined initial position with the sheet-like body entering the nip portion at the facing position. In the sheet-shaped body transport device that corrects the posture of the sheet-shaped body by returning the rotating body pair holding member to the body of revolution.
The rotating body pair has an upper downstream rotating member arranged in the upper stage of the transport path and a lower downstream rotating member arranged in the lower stage to form the nip portion, and the downstream rotating member pair. An upstream rotating member pair having an upper upstream rotating member and a lower upstream rotating member arranged on the upstream side of the side rotating member pair apart from the transport path, the upper downstream rotating member, and the upper upstream rotating member. It has an endless orbiting member that is hung between the members and between the lower downstream rotating member and the lower upstream rotating member, and spreads in a tapered shape from the nip portion toward the upstream side. A sheet-like body transporting device having a pair of endless rotating members. The transport path is formed between the first guide plate and the second guide plate arranged in parallel with each other, and the downstream end of the endless peripheral member pair is the first notch hole formed in the first guide plate and the said. The sheet-like body transport device according to claim 1, wherein the sheet-like body transfer device is arranged in each of the second notch holes formed in the second guide plate. A pair of rotating bodies that sandwich and transport the sheet-like body supplied to the transport path, and a pair of rotating bodies that hold the pair of rotating bodies and rotate along a transport surface including a nip portion of the pair of rotating bodies that sandwich the sheet-like body. It has a rotating body pair holding member that is capable and can be shifted and moved in the width direction of the transport path, and moves the rotating body pair to a facing position corresponding to the posture of the sheet-like body that is about to enter the nip portion. The rotating body pair is operated so as to receive the rotating body pair, and the rotating body pair is moved from the facing position to a predetermined initial position with the sheet-like body entering the nip portion at the facing position. In the sheet-shaped body transport device that corrects the posture of the sheet-shaped body by returning the rotating body pair holding member to the body of revolution.
One of the pair of rotating bodies is an upstream side rotating member that forms a nip portion with the other side rotating body and is arranged on the upstream side of the downstream side rotating member so as to be separated from the transport path. It has a member and an endless orbiting member spanned between the downstream rotating member and the upstream rotating member.
The transport path is formed between the first guide plate and the second guide plate arranged in parallel with each other, and the downstream end of the endless circuit member is arranged in the first notch hole formed in the first guide plate. A sheet-shaped body transfer device characterized in that the other side of the pair of rotating bodies is arranged in a second notch hole formed in the second guide plate. The sheet-like body transfer device according to claim 2 or 3, wherein the first guide plate and the second guide plate are integrally arranged on the rotating body pair holding member. The sheet-like body transfer device according to claim 2 or 3, wherein the first guide plate and the second guide plate are fixedly arranged separately from the rotating body pair holding member. The sheet-shaped body transfer device according to any one of claims 1 to 5, wherein at least one of the pairs of rotating bodies is composed of a plurality of divided rotating bodies divided in the axial direction. The sheet-like body transport device according to any one of claims 1 to 6, wherein the endless circuit member is composed of a flat belt or a round belt. The rotating body pair is a resist rotating body pair that transports the sheet-like body at a transfer timing toward an image forming portion arranged in the transport path on the downstream side of the rotating body pair. The sheet-shaped body transport device according to any one of claims 1 to 7. An image forming apparatus comprising the sheet-like body conveying apparatus according to any one of claims 1 to 8.