JP2012237892A - Image-forming device and recording material processing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image-forming device that enables mutual positioning of an image and a sheet with more accuracy, and a recording material processing unit.SOLUTION: A first edge detection sensor SK1 and a second edge detection sensor SK2 for detecting an edge of a sheet fed along a first sheet feeding path are provided on a downstream side of a first feeding roll 44, and a third edge detection sensor SK3 and a fourth edge detection sensor SK4 for detecting the edge of the sheet fed along a first sheet feeding path are provided on an upstream side of the first feeding roll 44. When there is a difficulty in detection at the first edge detection sensor SK1 and the second edge detection sensor SK2, the third edge detection sensor SK3 and the fourth edge detection sensor SK4 are used. The first edge detection sensor SK1 and the third edge detection sensor SK3 are arranged on a back side of the device, and the second edge detection sensor SK2 and the fourth edge detection sensor SK4 are arranged on a front side thereof.

Description

  The present invention relates to an image forming apparatus and a recording material processing apparatus.

For example, Japanese Patent Laid-Open No. 2004-133867 discloses a means for inverting paper once around an axis perpendicular to the direction of the paper transport path, and a lateral movement that reverses the paper once around an axis parallel to the direction of the paper transport path. There is disclosed an automatic printing apparatus provided with a reversing device and means for reversing the paper once around an axis perpendicular to the direction of the paper transport path.
Patent Document 2 discloses a roller pair that sandwiches a sheet material and conveys the sheet material with a central reference, and a sheet that detects one side end position in a direction orthogonal to the conveyance direction of the sheet material conveyed to the roller pair. Disclosed is a sheet material position deviation correcting device having material side end position detecting means.

JP-A-3-106765 JP-A-8-108956

  Here, when the sheet deviates with respect to the direction crossing the conveyance direction while being conveyed along the conveyance path, the sheet is aligned by accurately detecting the position of the sheet. However, it is assumed that it is difficult to accurately detect the position of the sheet. In such a case, it is difficult to accurately align the sheet and the image.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus and a recording material processing apparatus capable of more accurately aligning an image and a sheet.

The invention according to claim 1 has a conveyance path through which the recording material is conveyed, a conveyance means for conveying the recording material so as to move along the conveyance path, and a recording material conveyed by the conveyance means An image forming unit that forms an image on the recording medium; a first detection unit that detects a position of a side extending in a conveyance direction of the recording material conveyed by the conveyance unit before being conveyed to the image forming unit; and the conveyance A second detecting means for detecting the position of the side extending in the conveying direction of the recording material conveyed by the means by a method different from the first detecting means before being conveyed to the image forming unit; A selection unit that selects either a detection result by the first detection unit or a detection result by the second detection unit according to information, and a detection result selected by the selection unit, and is transported by the transport unit. Carry recording material And adjusting means for adjusting the position of the recording material on which an image is formed by the image forming section is displaced in a direction intersecting the transport direction by means, an image forming apparatus including a.
According to a second aspect of the present invention, when the image is formed on the second surface of the recording material on which the image is formed on the first surface of the recording material on which the image is formed by the image forming unit, the conveying unit The recording material is reversed so that the first side extending in the conveyance direction of the recording material conveyed by the first side and the second side positioned opposite to the first side are interchanged. The image forming apparatus according to claim 1, further comprising a supply unit that supplies the recording material to the transport path.
According to a third aspect of the present invention, the first detection unit and the second detection unit are conveyed by the conveyance unit when an image is formed on the first surface of the recording material by the image forming unit. A recording medium conveyed by the conveying means when an image is formed on the second surface of the recording material by the image forming unit. 3. The image forming apparatus according to claim 2, further comprising: a second surface detection unit that detects the position of the first side of the material and that is different from the first surface detection unit.
According to a fourth aspect of the present invention, the first detection unit is a fixed type, and the second detection unit moves the side of the recording material by moving in a direction intersecting the conveyance direction by the conveyance unit. The detection means is a mobile type, and the adjustment means selects a detection result of the second detection means when it is determined that detection by the first detection means is difficult based on the acquired information. Item 4. The image forming apparatus according to any one of Items 1 to 3.
According to a fifth aspect of the present invention, the first detection unit and the second detection unit are disposed in the vicinity of the adjustment unit with the adjustment unit interposed therebetween, and one of the first detection unit and the second detection unit is transported by the transport unit. 5. The image forming apparatus according to claim 4, wherein the image forming apparatus is located upstream of the image forming apparatus and the other image forming apparatus is disposed on the downstream side in the conveying direction of the conveying unit.
According to a sixth aspect of the present invention, the selection unit includes the detection result of the first detection unit and the second detection unit before the recording material on which an image is formed by the image forming unit is conveyed by the conveyance unit. The image forming apparatus according to claim 5, wherein any one of detection results by the detection unit is selected.

The invention according to claim 7 has a transport path through which the recording material is transported, a transport means for transporting the recording material so as to move along the transport path, a processing section for processing the recording material, First detection means for detecting a position of a side extending in the transport direction of the recording material transported to the processing unit by the transport means, and a position of the side extending in the transport direction of the recording material transported by the transport means The second detection means for detecting the detection method by a method different from the first detection means, and the detection result by the first detection means and the detection result by the second detection means are selected according to the acquired information. A recording unit including a selection unit, and an adjustment unit that uses the detection result selected by the selection unit and adjusts the position of the recording material conveyed by the conveyance unit by displacing the recording material in a direction intersecting the conveyance direction of the conveyance unit. Material processing equipment It is.
According to an eighth aspect of the present invention, when an image is formed on the second surface of the recording material on which the image is formed on the first surface of the recording material, the recording material is conveyed in the conveying direction by the conveying means. The front and back sides of the recording material are reversed so that the extending first side and the second side located on the opposite side of the first side are interchanged, and the reversed recording material is transferred to the transport path. The recording material processing apparatus according to claim 7, further comprising a supply unit that supplies the recording material.

According to the first aspect, compared with the case where the present invention is not adopted, it is possible to more accurately align the image and the paper.
According to the second aspect, compared with the case where the present invention is not adopted, it is possible to perform the mutual alignment between the image and the paper more accurately even if the shift in the direction intersecting the transport direction is likely to occur. .
According to the third aspect, it is possible to cope with a situation where it is more difficult to accurately detect the position of the sheet than in the case where the present invention is not adopted.
According to the fourth aspect, it is possible to more accurately align the image and the paper while reducing the occurrence of erroneous detection as compared with the case where the present invention is not adopted.
According to the fifth aspect, it is possible to further reduce the size of the apparatus as compared with the case where the present invention is not adopted.
According to the sixth aspect, it is possible to more easily control the alignment between the image and the paper as compared with the case where the present invention is not adopted.
According to the seventh aspect, compared with the case where the present invention is not adopted, it is possible to more accurately align the image and the paper.
According to the eighth aspect, compared with the case where the present invention is not adopted, it is possible to perform the mutual alignment between the image and the paper more accurately even if the shift in the direction intersecting the transport direction is likely to occur. .

1 is a diagram when an image forming apparatus to which the exemplary embodiment is applied is viewed from the front side. It is a figure for demonstrating a reverse mechanism. It is a figure at the time of seeing the inversion mechanism from the arrow III direction of FIG. FIG. 4 is a diagram when a first sheet conveyance path is viewed from the direction of arrow IV in FIG. 1. It is a figure for demonstrating a moving mechanism. It is a flowchart which shows the process sequence performed by a control part.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a diagram of an image forming apparatus 100 to which the exemplary embodiment is applied as viewed from the front side.
An image forming apparatus 100 shown in FIG. 1 has a so-called tandem configuration, and includes a plurality of image forming units 10 (10Y, 10M, 10C, and 10K) that form toner images of respective color components by an electrophotographic method. I have. In addition, the image forming apparatus 100 according to the present embodiment includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and the like, and controls the operation of each device and each part of the image forming device 100. A control unit 80 is provided. Further, a user interface unit (UI) 90 is provided that is configured by a display panel and outputs an instruction received from the user to the control unit 80 and presents information from the control unit 80 to the user. Further, for example, a receiving unit 70 that receives image data or the like from a personal computer (PC) or an image reading device (scanner) is provided.
The image forming unit 10 is an example of an image forming unit.

  In addition, the image forming apparatus 100 sequentially transfers (primary transfer) each color component toner image formed by each image forming unit 10 and holds each color component toner image, and the intermediate transfer belt 20. And a secondary transfer device 30 that collectively transfers (secondary transfer) the color component toner images on the paper P formed in a rectangular shape. The paper P is an example of a recording material.

The image forming apparatus 100 also includes a first paper transport path R1 through which the paper P transported toward the secondary transfer device 30 passes, and a second paper P through which the paper P after passing through the secondary transfer device 30 passes. A sheet conveyance path R2 and a third sheet conveyance path R3 that branches from the second sheet conveyance path R2 downstream of the fixing device 50 (described later) and extends to below the first sheet conveyance path R1 are provided. Yes. The first paper transport path R1 is an example of a transport path.
Here, in the first paper transport path R1 to the third paper transport path R3, two of the four side edges of the paper P facing each other are the paper transport paths R1, R2, R3. The paper P is transported so as to move along One side of the two opposite sides of the sheet P is an example of the first side, and the other side located on the opposite side of the one side is the second side. It is an example of a side.

In the present embodiment, the paper P is transported from the third paper transport path R3 to the first paper transport path R1, and the paper P is supplied to the first paper transport path R1 by inverting the front and back of the paper P. A reversing mechanism 500 is provided. In other words, the reversing mechanism 500 reverses the paper P around the axis along the paper transport direction in the first paper transport path R1 and the paper transport direction in the third paper transport path R3.
Furthermore, in this embodiment, an opening 102 is formed in the casing 101 of the image forming apparatus 100. Here, the paper P transported along the second paper transport path R2 is discharged to the outside of the housing 101 through the opening 102 and is stacked on a paper stacking unit (not shown). A processing device (not shown) may be provided adjacent to the housing 101 to further perform processing such as punching the paper P discharged from the opening 102.

Further, the image forming apparatus 100 is provided with a first paper supply device 410 that supplies the paper P to the first paper transport path R1. Further, a second paper supply device 420 that is provided upstream of the first paper supply device 410 in the conveyance direction of the paper P and supplies the paper P to the first paper conveyance path R1 is provided.
The first paper supply device 410 and the second paper supply device 420 are configured in the same manner, and each of the first paper supply device 410 and the second paper supply device 420 has a paper storage unit 41 that stores the paper P. And a take-out roll 42 for taking out and transporting the paper P stored in the paper storage unit 41.

A first transport roll 44 that transports the paper P on the first paper transport path R1 toward the secondary transfer apparatus 30 on the first paper transport path R1 and upstream of the secondary transfer apparatus 30 is provided. Is provided. Further, the second transport roll 45 that transports the paper P toward the first transport roll 44, the third transport roll 46 that transports the paper P toward the second transport roll 45, and the third transport roll 46. A fourth transport roll 47 that transports the paper P is provided.
The 1st conveyance roll 44, the 2nd conveyance roll 45, the 3rd conveyance roll 46, and the 4th conveyance roll 47 are examples of a conveyance means.

In addition to these transport rolls, the transport of transporting the paper P located on these paper transport paths to the first paper transport path R1, the second paper transport path R2, and the third paper transport path R3. A plurality of rolls 48 are provided.
The first transport roll 44, the second transport roll 45, the third transport roll 46, the fourth transport roll 47, and the transport roll 48 are configured by a pair of roll-shaped members that are rotatably provided and press each other. One roll-shaped member is rotationally driven to carry the paper P.

In the present embodiment, an abutting member 300 to which the leading end of the paper P is abutted is provided between the second conveying roll 45 and the third conveying roll 46. In the present embodiment, the skew of the paper P (the inclination of the paper P with respect to the transport direction) is corrected by abutting the leading end of the paper P against the abutting member 300.
Note that after the skew of the paper P is corrected by the abutting member 300, the abutting member 300 is retracted from the first paper transport path R1. In the present embodiment, a fixing device 50 for fixing the image secondarily transferred onto the paper P by the secondary transfer device 30 is provided on the second paper transport path R2.

  Further, between the secondary transfer device 30 and the fixing device 50, a transport device 51 that transports the paper P that has passed through the secondary transfer device 30 to the fixing device 50 is provided. Here, the transport device 51 includes a belt 51A that moves around, and transports the paper P by placing the paper P on the belt 51A. The fixing device 50 is provided with a heating roll 50A that is heated by a built-in heater (not shown) and a pressing roll 50B that presses the heating roll 50A. In the fixing device 50, the paper P is pressurized and heated by passing the paper P between the heating roll 50A and the pressing roll 50B. As a result, the image on the paper P is fixed on the paper P.

  Here, each of the image forming units 10 that function as a part of the image forming unit includes a photosensitive drum 11 that is rotatably mounted. Further, around the photosensitive drum 11, a charging device 12 that charges the photosensitive drum 11, an exposure device 13 that exposes the photosensitive drum 11 to write an electrostatic latent image, and an electrostatic on the photosensitive drum 11. And a developing device 14 that visualizes the latent image with toner. Further, a primary transfer device 15 that transfers each color component toner image formed on the photosensitive drum 11 to the intermediate transfer belt 20 and a drum cleaning device 16 that removes residual toner on the photosensitive drum 11 are provided. Yes.

The intermediate transfer belt 20 is provided so as to be stretched over the three roll members 21 to 23. Of these three roll members 21 to 23, the roll member 22 drives the intermediate transfer belt 20. The roll member 23 is disposed opposite to the secondary transfer roll 31 with the intermediate transfer belt 20 interposed therebetween, and the secondary transfer device 30 is configured by the secondary transfer roll 31 and the roll member 23.
A belt cleaning device 24 for removing residual toner on the intermediate transfer belt 20 is provided at a position facing the roll member 21 across the intermediate transfer belt 20.

  Further, in the image forming apparatus 100 according to the present embodiment, an image can be formed on the first surface of the paper P supplied from the first paper supply device 410 or the like, and in addition, the image can be formed on the second surface of the paper P. An image can be formed. More specifically, in this image forming apparatus 100, the front and back of the paper P that has passed through the fixing device 50 are reversed by the reversing mechanism 500, and the paper P with the front and back reversed is conveyed to the secondary transfer device 30 again. The Then, the image is transferred onto the second surface of the paper P by the secondary transfer device 30. Thereafter, the sheet P passes through the fixing device 50 again, and the transferred image is fixed on the sheet P. As a result, an image is formed not only on the first side of the paper P but also on the second side.

FIG. 2 is a diagram for explaining the reversing mechanism 500.
As described above, in the present embodiment, a plurality of transport rolls 48 that transport the paper P along the third paper transport path R3 are provided in the third paper transport path R3. A plurality of transport rolls 48 that transport the paper P along the first paper transport path R1 are also provided in the first paper transport path R1. The third paper transport path R3 is provided with a transport roll 91 that transports the paper P in a direction substantially perpendicular to (intersects with) the transport direction of the paper P in the third paper transport path R3. In other words, the transport roller 91 transports the paper P toward the side of the third paper transport path R3.

Furthermore, in the present embodiment, the sheet P transported by the transport roll 91 moves upward, and the sheet P moved upward further moves toward the first sheet transport path R1. In addition, a guide member 92 for guiding the paper P is provided. Further, in the present embodiment, there is provided a conveyance roll 93 that nips the sheet P guided by the guide member 92 and whose leading end faces upward, and conveys the sheet P further upward. The first paper transport path R1 is provided with a transport roll 94 that transports the paper P transported by the transport roll 93 to a predetermined location on the first paper transport path R1.
In the present embodiment, a drive motor (not shown) that rotates the transport roll 48, the transport roll 91, the transport roll 93, and the transport roll 94 is provided. This drive motor is composed of a stepping motor.

  In addition, each of the conveyance roll 48 is comprised by a pair of roll-shaped member as above-mentioned. Moreover, the conveyance roll 91, the conveyance roll 93, and the conveyance roll 94 are also comprised by a pair of roll-shaped member which mutually presses. In FIG. 2, only one roll-shaped member of the pair of roll-shaped members constituting the transport roll 48, the transport roll 91, the transport roll 93, and the transport roll 94 is illustrated.

  Moreover, in this Embodiment, one roll-shaped member provided in the conveyance roll 48 can be spaced apart from the other roll-shaped member. The same applies to the transport roll 91 and the transport roll 94, and one roll-shaped member can be separated from the other roll-shaped member. Further, a separation mechanism (not shown) for separating the one roll-shaped member from the other roll-shaped member is provided. This separation mechanism is configured by existing technology such as a motor and a cam.

  When the paper P is turned upside down by the reversing mechanism 500, the paper P is first transported along the third paper transport path R3 by the transport roll 48. At this time, one roll-shaped member of the transport rolls 91 provided in the third paper transport path R3 is separated from the other roll-shaped member. Next, one roll-shaped member of the transport roll 48 is separated from the other roll-shaped member, and one roll-shaped member of the transport roll 91 is pressed against the other roll-shaped member via the paper P.

  Next, the transport roll 91, the transport roll 93, and the transport roll 94 are driven to rotate, and the paper P is transported toward the first paper transport path R1. At this time, one roll-shaped member of the transport roll 48 provided in the first paper transport path R1 is separated from the other roll-shaped member. When the paper P is transported to a predetermined location on the first paper transport path R1, the rotational driving of the transport roll 91, the transport roll 93, and the transport roll 94 is stopped. Thereafter, one roll-shaped member in the transport roll 94 is separated from the other roll-shaped member, and one roll-shaped member of the transport roll 48 provided in the first paper transport path R1 is placed on the other roll via the paper P. Is pressed against the member.

Next, the transport roll 48 is driven to rotate, and the paper P is transported along the first paper transport path R1. At this time, the front and back of the paper P are already reversed.
Here, in the reversing mechanism 500 according to the present embodiment, the front and back are reversed without the front end and the rear end in the transport direction of the paper P being interchanged. On the other hand, in the reversing mechanism 500 in the present embodiment, one side and the other side of the paper are interchanged.

  FIG. 3 is a view when the reversing mechanism 500 is viewed from the direction of arrow III in FIG. 3, illustration of the conveyance roll 91 and the conveyance roll 94 shown in FIG. 2 is omitted. In FIG. 3, the guide member 92 shown in FIG. 2 is not shown.

In the reversing mechanism 500 in the present embodiment, as shown in FIG. 3, the fourth paper transport path R4 is connected to the fourth paper transport path R4 that connects the third paper transport path R3 and the first paper transport path R1. Is provided with a detection sensor FS1 for detecting the leading end of the paper P conveyed along the line.
In the present embodiment, the paper P is transported in the first paper transport path R1 to the third paper transport path R3 so that the two sides of the paper P move along these paper transport paths. However, in the fourth paper transport path R4, the paper P is transported with one of the two sides being the head. The paper P is supplied to the first paper transport path R1 from the side of the first paper transport path R1.

In the present embodiment, a driving motor (not shown) is driven by a predetermined number of steps after the leading edge of the paper P is detected by the detection sensor FS1. As a result, as described above, the paper P is transported to a predetermined location on the first paper transport path R1.
The detection sensor FS1 can also be configured by a so-called reflective sensor including a light emitting element and a light receiving element, or a light emitting element is disposed on one side of the fourth paper transport path R4 and a light receiving element is disposed on the other side. It can also be constituted by a so-called transmission type sensor.

FIG. 4 is a view when the first paper transport path R1 is viewed from the direction of arrow IV in FIG.
As shown in the figure, in the present embodiment, a first side detection sensor that detects the side of the paper P that has been transported along the first paper transport path R1 downstream of the first transport roll 44. SK1 and a second side detection sensor SK2 are provided. In the present embodiment, the third side detection sensor SK3 and the fourth side detection sensor SK3 that detect the side of the paper P that has been transported along the first paper transport path R1 also upstream of the first transport roll 44. A side detection sensor SK4 is provided. The first side detection sensor SK 1, the second side detection sensor SK 2, the third side detection sensor SK 3, and the fourth side detection sensor SK 4 are located in the vicinity of the first transport roll 44.

  In the present embodiment, the first side detection sensor SK1 and the second side detection sensor SK2 are arranged on the downstream side of the first conveyance roll 44, and the third side detection sensor SK3 is located on the upstream side of the first conveyance roll 44. Although the fourth side detection sensor SK4 is arranged, the reverse arrangement is also conceivable. That is, the first side detection sensor SK1 and the second side detection sensor SK2 are arranged on the upstream side of the first conveyance roll 44, and the third side detection sensor SK3 and the fourth side are arranged on the downstream side of the first conveyance roll 44. This is a modified example in which the side detection sensor SK4 is arranged.

  The first side detection sensor SK1 and the second side detection sensor SK2 are examples of edge sensors or first detection means, and the third side detection sensor SK3 and the fourth side detection sensor SK4 are edges. It is an example of a sensor thru | or a 2nd detection means. The first side detection sensor SK1 and the third side detection sensor SK3 are examples of the first surface detection unit, and the second side detection sensor SK2 and the fourth side detection sensor SK4 are the second It is an example of a surface detection part.

  More specifically, the first side detection sensor SK1 and the second side detection sensor SK2 are fixed sensors that do not move relative to the apparatus main body during the side detection, and the third side detection sensor SK3. The fourth side detection sensor SK4 is a movable sensor that performs side detection by moving relative to the apparatus main body. In this manner, the first side detection sensor SK1, the second side detection sensor SK, the third side detection sensor SK3, and the fourth side detection sensor SK4 detect the edge of the paper P by different methods. For example, a CIS (Contact Image Sensor) may be used as the fixed sensor.

The first side detection sensor SK1 and the third side detection sensor SK3 are arranged on the back side (rear side) of the image forming apparatus 100. The second side detection sensor SK2 and the fourth side detection sensor SK4 are disposed on the front side (front side) of the image forming apparatus 100.
The reason why the sensors are provided on the back side and the near side of the image forming apparatus 100 is that the front and back sides of the paper P are reversed so that the opposite sides of the paper P are mutually switched by the reversing mechanism 500. is there. In other words, the position of one side of the sheet whose position has been detected before being reversed by the reversing mechanism 500 is detected even after it has been reversed by the reversing mechanism 500. Accordingly, in the case where the sides detected for position before and after being reversed by the reversing mechanism 500 may be different, a configuration example in which sensors are arranged only on either the back side or the near side of the image forming apparatus 100 is also possible. Conceivable.

  Here, in each of the first side detection sensor SK1 and the second side detection sensor SK2, a plurality of light receiving elements 40 are arranged in a direction substantially orthogonal to the conveyance direction of the paper P. In this embodiment, irradiation light from a light source (not shown) such as a plurality of LEDs arranged along the direction in which the light receiving elements 40 are arranged is applied to the paper P and reflected light from the paper P is received. Light is received by the light receiving element 40. In the present embodiment, the signals obtained from each of the light receiving elements 40 are binarized, and the density level change point after binarization is detected as the side of the paper P.

Further, the third side detection sensor SK3 and the fourth side detection sensor SK4 are configured by reflective sensors, similar to the detection sensor FS1. As described above, so-called transmissive sensors can be used for the third side detection sensor SK3 and the fourth side detection sensor SK4.
Further, in the present embodiment, the first movement mechanism 110 that moves the third side detection sensor SK3 in a direction substantially perpendicular to the conveyance direction of the paper P (direction intersecting), and the fourth side detection sensor SK4 are used as the paper. And a second moving mechanism 120 that moves in a direction substantially perpendicular to the transport direction of P.

Here, the first moving mechanism 110 includes an endless belt 111 to which the third side detection sensor SK3 is attached, a pulley 112 that drives the belt 111, a motor (not shown) that rotates the pulley 112, It has. By driving this motor and rotating the pulley 112, the belt 111 is rotated, and the third side detection sensor SK3 is moved in a direction substantially orthogonal to the conveyance direction of the paper P.
Similarly, the second moving mechanism 120 has an endless belt 111 to which the fourth side detection sensor SK4 is attached, a pulley 112 that drives the belt 111, and a motor (not shown) that rotates the pulley 112. And.

In the present embodiment, the first transport roll 44 is provided so as to be movable along a direction substantially orthogonal to the transport direction of the paper P. Further, a moving mechanism 200 that moves the first transport roll 44 is provided. The control unit 80 is an example of a selection unit, and the moving mechanism 200 and the control unit 80 are examples of an adjustment unit.
FIG. 5 is a diagram for explaining the moving mechanism 200.
As shown in FIG. 5, the moving mechanism 200 includes a rack gear 210 attached to the end of the first transport roll 44, a pinion gear 220 that meshes with the rack gear 210, a gear motor 230 that rotates the pinion gear 220, It is comprised by. In the present embodiment, the first transport roll 44 moves in a direction substantially orthogonal to the transport direction of the paper P by rotating the gear motor 230 forward and backward.

  Here, in the image forming apparatus 100 according to the present embodiment, the paper P may be transported in a state where the paper P is displaced in a direction substantially perpendicular to the transport direction of the paper P due to a mechanical error or the like. In this case, an image may be formed at a location different from the location intended by the user. In other words, there is a possibility that an image is formed at a location shifted from a predetermined location in the substantially orthogonal direction.

  For this reason, in this embodiment, the first transport roll 44 is used to move the paper P that has been transported in a state of being shifted in the substantially orthogonal direction in the substantially orthogonal direction. In other words, the paper P is moved in a direction substantially orthogonal to the transport direction of the paper P by moving the first transport roll 44 sandwiching the paper P in the axial direction. As a result, the paper P passes through a predetermined location on the first paper transport path R1, and an image is formed at a location intended by the user. In other words, by moving the first transport roll 44 in the axial direction, the image formation position on the paper P is changed, and an image is formed at a location intended by the user.

FIG. 6 is a flowchart showing a processing procedure executed by the control unit 80.
In the flowchart shown in FIG. 6, when receiving a print instruction, the control unit 80 acquires various types of information such as the type, conveyance format, and image density of the paper P (step 101). Various types of information can be grasped based on information input by the user through the UI 90 (see FIG. 1) or information received by the receiving unit 70.
The type of paper P here is information for specifying plain paper, thick paper, thin paper, and the like. In addition to the information for specifying single-sided printing or double-sided printing, the conveyance format of the paper P is information for specifying the presence or absence of so-called reprinting. The image density is information for specifying whether to perform so-called pre-printing.

By using any one or a plurality of such various information in combination, the fixed first side detection sensor SK1 and the second side detection sensor SK2 are selected, or the movable third side detection sensor It is determined whether to select SK3 and the fourth side detection sensor SK4 (step 102).
More specifically, the fixed first side detection sensor SK1 and the second side detection sensor SK2 that normally have an advantage in preventing false detection are selected. However, it may be difficult to detect the position of the side of the paper P with the fixed first side detection sensor SK1 and the second side detection sensor SK2. For example, when the paper P is used by, for example, an overhead projector (OHP), when the printing surface of the paper is black, and when the paper P is thin, it is assumed that the detection is difficult. Therefore, if it is determined that it is difficult to detect the position of the side with the fixed type, the movable third side detection sensor is used instead of the normally used fixed first side detection sensor SK1 and second side detection sensor SK2. SK3 and the fourth side detection sensor SK4 are selected. By controlling in this way, the position of the side is detected corresponding to various conditions such as the type of paper and the image, so that the position can be accurately detected without causing erroneous detection.

The control unit 80 starts transporting the paper P after selecting a sensor to be used for side position detection (step 103). Then, the control unit 80 detects the position of one side edge of the paper P using the selected sensor (step 104). Further, the control unit 80 calculates a positional deviation amount in a direction intersecting the conveyance direction of the paper P based on the grasped actual passing position, and moves the first conveyance roll 44 by the moving mechanism 200 by the calculated deviation amount. To adjust the position (step 105).
For such misregistration amount, for example, a LUT (Look Up Table) preliminarily defining the relationship between the size of the paper P and the position of the side of the paper P is stored in advance in a ROM or the like, and this LUT is referred to. Can be grasped.

  In this embodiment, the conveyance of the paper P is started after the sensor is selected. However, a control example in which the sensor is selected after the conveyance of the paper P is started can be considered. Further, as a sensor selection method, a control example in which detection is attempted by the fixed first side detection sensor SK1 and the second side detection sensor SK2 may be considered. That is, when the detection by the fixed type is successful, the position of the paper P is adjusted by the moving mechanism 200 using the detection result. On the other hand, when the detection by the fixed type is not successful, switching to the movable third side detection sensor SK3 and the fourth side detection sensor SK4 is performed. In this way, the position of the sheet P is adjusted by detecting the position of the side of the sheet P.

  As described above, in the present embodiment, it is possible to more accurately align the image and the paper. In this embodiment, the case where the present invention is applied to the image forming apparatus has been described. However, the place where post-processing such as stapling, punching, and embossing is performed on the paper P is changed. For example, the present invention may be applied to a recording material processing apparatus.

DESCRIPTION OF SYMBOLS 10 ... Image forming unit, 44 ... 1st conveyance roll, 45 ... 2nd conveyance roll, 46 ... 3rd conveyance roll, 47 ... 4th conveyance roll, 48 ... Conveyance roll, 51 ... Conveyance apparatus, 80 ... Control part, 100 DESCRIPTION OF SYMBOLS Image forming apparatus 200 ... Moving mechanism 500 ... Reversing mechanism R1 ... First paper transport path SK1 ... First side detection sensor SK2 ... Second side detection sensor SK3 ... Third side detection sensor SK4 ... Fourth side detection sensor

Claims (8)

A transport unit that transports the recording material so that the recording material is transported along the transport path;
An image forming unit that forms an image on a recording material conveyed by the conveying unit;
First detection means for detecting a position of a side extending in the conveyance direction of the recording material conveyed by the conveyance means before being conveyed to the image forming unit;
A second detection unit that detects a position of a side extending in the conveyance direction of the recording material conveyed by the conveyance unit by a method different from the first detection unit before being conveyed to the image forming unit;
Selection means for selecting either the detection result by the first detection means or the detection result by the second detection means according to the acquired information;
The position of the recording material on which the image is formed by the image forming unit by using the detection result selected by the selection unit and displacing the recording material conveyed by the conveying unit in a direction intersecting the conveying direction by the conveying unit. Adjusting means for adjusting
An image forming apparatus including:   The conveyance direction of the recording material conveyed by the conveyance means when an image is formed on the second surface of the recording material on which the image is formed on the first surface of the recording material on which the image is formed by the image forming unit The front and back sides of the recording material are reversed so that the first side extending to the second side and the second side positioned opposite to the first side are interchanged with each other, and the reversed recording material is transferred to the transport path. The image forming apparatus according to claim 1, further comprising supply means for supplying to the image forming apparatus.   The first detection unit and the second detection unit are configured such that the first side of the recording material conveyed by the conveyance unit when an image is formed on the first surface of the recording material by the image forming unit. A first surface detection unit that detects the position of the side, and the first side of the recording material conveyed by the conveying unit when an image is formed on the second surface of the recording material by the image forming unit. The image forming apparatus according to claim 2, further comprising: a second surface detection unit that detects a position and is different from the first surface detection unit. The first detection unit is a fixed type, and the second detection unit is a movable type that detects a side of the recording material by moving in a direction intersecting a conveyance direction by the conveyance unit,
The adjustment unit selects a detection result of the second detection unit when it is determined that the detection is difficult by the first detection unit based on the acquired information. 2. The image forming apparatus according to item 1.   The first detection unit and the second detection unit are disposed in the vicinity of the adjustment unit with the adjustment unit interposed therebetween, and one of the first detection unit and the second detection unit is located upstream in the conveyance direction of the conveyance unit, and the other is The image forming apparatus according to claim 4, wherein the image forming apparatus is located downstream in a conveyance direction by the conveyance unit.   The selection unit is configured to determine either the detection result by the first detection unit or the detection result by the second detection unit before the recording material on which an image is formed by the image forming unit is conveyed by the conveyance unit. The image forming apparatus according to claim 5, wherein the image forming apparatus is selected. A transport unit that transports the recording material so that the recording material is transported along the transport path;
A processing unit for processing the recording material;
First detection means for detecting a position of a side extending in the conveyance direction of the recording material conveyed to the processing unit by the conveyance means;
Second detection means for detecting the position of the side extending in the conveyance direction of the recording material conveyed by the conveyance means by a method different from the first detection means;
Selection means for selecting either the detection result by the first detection means or the detection result by the second detection means according to the acquired information;
Using the detection result selected by the selection means, adjusting means for adjusting the position by displacing the recording material conveyed by the conveyance means in a direction intersecting the conveyance direction by the conveyance means;
A recording material processing apparatus including:   When an image is formed on the second surface of the recording material on which the image is formed on the first surface of the recording material, the first side extending in the transport direction of the recording material transported by the transport means and the first side And further comprising a supply means for reversing the front and back of the recording material so that the second side located on the opposite side of the first side is interchanged, and supplying the reversed recording material to the transport path. The recording material processing apparatus according to claim 7, wherein the recording material processing apparatus is a recording material processing apparatus.

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