阅读说明：本技术 记录材搬送装置以及图像形成装置 (Recording material conveying device and image forming apparatus ) 是由 鹈川贵之 于 2020-06-05 设计创作，主要内容包括：一种记录材搬送装置以及图像形成装置,与针对伴随记录材到达预定部位而移动的每个移动部来设置探测所述移动部的探测部件的情况相比,减少进行伴随记录材到达预定部位而移动的移动部的探测的探测部件的数量。本发明的记录材搬送装置包括：第一被按压部,被受到搬送的记录材按压而移动；第二被按压部,在受到搬送的记录材的宽度方向上配置在与所述第一被按压部不同的部位,被受到搬送的记录材按压而移动；移动部,设为与所述第一被按压部及所述第二被按压部的两者联动,当所述第一被按压部及所述第二被按压部的至少一者被记录材按压时,所述移动部移动；以及探测部件,探测所述移动部的移动。(A recording material conveying device and an image forming apparatus, wherein the number of detection members for detecting a moving part moving along with the recording material reaching a predetermined position is reduced compared with the case that a detection member for detecting the moving part is arranged for each moving part moving along with the recording material reaching the predetermined position. The recording material conveying device of the invention comprises: a first pressed portion which is pressed by the conveyed recording material and moves; a second pressed portion which is arranged at a position different from the first pressed portion in the width direction of the recording material being conveyed, and which is pressed by the recording material being conveyed to move; a moving portion configured to be interlocked with both the first pressed portion and the second pressed portion, the moving portion moving when at least one of the first pressed portion and the second pressed portion is pressed by a recording material; and a detection means for detecting the movement of the moving section.)

1. A recording material conveying device includes:

a first pressed portion which is pressed by the conveyed recording material and moves;

a second pressed portion which is arranged at a position different from the first pressed portion in the width direction of the recording material being conveyed, and which is pressed by the recording material being conveyed to move;

a moving portion configured to be interlocked with both the first pressed portion and the second pressed portion, the moving portion moving when at least one of the first pressed portion and the second pressed portion is pressed by a recording material; and

and a detection means for detecting the movement of the moving section.

2. The recording material conveying device according to claim 1, wherein

The first pressed portion and the second pressed portion move in one direction when pressed by a recording material,

one of the first pressed portion and the second pressed portion is disposed on a downstream side in the one direction than the other.

3. The recording material conveying device according to claim 2, wherein

When a recording material of a specific size is conveyed and the recording material reaches the first pressed portion, the first pressed portion is located at a position facing an end portion of the recording material in the width direction, and when the recording material reaches the second pressed portion, the second pressed portion is located at a position facing a central portion of the recording material in the width direction,

the second pressed portion is disposed downstream in the one direction from the first pressed portion.

4. The recording material conveying device according to claim 1, wherein

The moving portion is disposed closer to one of the first pressed portion and the second pressed portion.

5. The recording material conveying device according to claim 4, wherein

One of the pressed portions includes a part of a plate-like member arranged along a thickness direction of the recording material being conveyed,

the moving part is arranged on an extension line of the plate-shaped component.

6. The recording material conveying device according to claim 5, wherein

When a recording material of a specific size is conveyed and the recording material reaches the plate-like member, the plate-like member is positioned at a position facing an end portion of the recording material in a width direction,

the moving part is arranged on an extension line of the plate-shaped member, and the plate-shaped member is positioned at the opposite position of the end part.

7. The recording material conveying apparatus according to claim 1, further comprising:

a third pressed portion which is arranged at a position different from the first pressed portion and the second pressed portion in a width direction of the recording material being conveyed, and which is pressed by the recording material being conveyed to move;

a second moving portion that moves in conjunction with the third pressed portion; and

and a second detection means for detecting the movement of the second moving part.

8. The recording material conveying device according to claim 7, wherein

A first moving portion that is the moving portion that is interlocked with the first pressed portion and the second pressed portion, and a second moving portion that is interlocked with the third pressed portion are provided so as to be movable in one direction,

the position of the first moving portion in the one direction is different from the position of the second moving portion in the one direction in a state where the first pressed portion, the second pressed portion, and the third pressed portion are not pressed by a recording material.

9. The recording material conveying device according to claim 7, wherein

A first moving portion that is the moving portion that is interlocked with the first pressed portion and the second pressed portion, and a second moving portion that is interlocked with the third pressed portion are provided so as to be movable in one direction,

the position in the direction of the detection position of the first moving part detected by the first detection means, which is the detection means for detecting the movement of the first moving part, is different from the position in the direction of the detection position of the second moving part detected by the second detection means.

10. An image forming apparatus includes:

an image forming unit that forms an image on a recording material; and a recording material conveying device configured to convey a recording material, the recording material conveying device including the recording material conveying device according to any one of claims 1 to 9.

11. A recording material conveying device includes:

a first pressed member which is pressed by the conveyed recording material and moves;

a second pressed member which is arranged at a position different from the first pressed member in the width direction of the recording material being conveyed, and which is pressed by the recording material being conveyed and moves;

a moving member configured to move in conjunction with both the first pressed member and the second pressed member when at least one of the first pressed member and the second pressed member is pressed by a recording material; and

a detecting member that detects movement of the moving member.

Technical Field

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

Background

Patent document 1 discloses a configuration in which: between the transfer unit and the fixing unit, a plurality of loop sensors (loop sensors) are provided in the recording medium direction, and a motor control portion controls the fixing motor based on the loop detection results thereof.

Patent document 2 discloses a process of: when the measured value of any one of the loop sensors exceeds a certain value, the driving speed of the fixing member is changed or the posture of the conveying guide is changed, thereby avoiding the occurrence of problems.

[ Prior art documents ]

[ patent document ]

Patent document 1: japanese patent laid-open No. 2007-52112

Patent document 2: japanese patent laid-open publication No. 2011-90092

Disclosure of Invention

[ problems to be solved by the invention ]

In an apparatus for conveying a recording material, a moving section that moves as the recording material reaches a predetermined location is provided, and by detecting the movement of the moving section, it is possible to detect that the recording material has reached the predetermined location.

Here, if a plurality of moving portions are provided and further detecting means for detecting the moving portions are provided corresponding to the respective moving portions, the detecting means should be provided in a number corresponding to the number of the moving portions.

The present invention has an object to reduce the number of detecting members for detecting a moving portion that moves as a recording medium reaches a predetermined portion, as compared with a case where a detecting member for detecting the moving portion is provided for each moving portion that moves as the recording medium reaches the predetermined portion.

[ means for solving problems ]

The invention described in claim 1 is a recording material conveying device including: a first pressed portion which is pressed by the conveyed recording material and moves; a second pressed portion which is arranged at a position different from the first pressed portion in the width direction of the recording material being conveyed, and which is pressed by the recording material being conveyed to move; a moving portion configured to be interlocked with both the first pressed portion and the second pressed portion, the moving portion moving when at least one of the first pressed portion and the second pressed portion is pressed by a recording material; and a detection means for detecting the movement of the moving section.

The invention described in claim 2 is the recording material conveying apparatus according to claim 1, wherein the first pressed portion and the second pressed portion move in one direction when the recording material is pressed, and one of the first pressed portion and the second pressed portion is disposed downstream of the other pressed portion in the one direction.

The invention described in claim 3 is the recording material conveying apparatus according to claim 2, wherein when a recording material of a specific size is conveyed and the recording material reaches the first pressed portion, the first pressed portion is located at a position facing an end portion of the recording material in the width direction, and when the recording material reaches the second pressed portion, the second pressed portion is located at a position facing a central portion of the recording material in the width direction, and the second pressed portion is arranged downstream in the one direction from the first pressed portion.

The invention described in claim 4 is the recording material conveying apparatus according to claim 1, wherein the moving portion is disposed closer to one of the first pressed portion and the second pressed portion.

The invention described in claim 5 is the recording material conveying apparatus according to claim 4, wherein the one pressed portion includes a part of a plate-like member disposed along a thickness direction of the recording material to be conveyed, and the moving portion is provided on an extension line of the plate-like member.

The invention described in claim 6 is the recording material conveying apparatus according to claim 5, wherein when a recording material of a specific size is conveyed and the recording material reaches the plate-like member, the plate-like member is located at a position facing an end portion in a width direction of the recording material, the moving portion is provided on an extension line of the plate-like member, and the plate-like member is located at a position facing the end portion.

The invention described in claim 7 is the recording material conveying apparatus described in claim 1, further comprising: a third pressed portion which is arranged at a position different from the first pressed portion and the second pressed portion in a width direction of the recording material being conveyed, and which is pressed by the recording material being conveyed to move; a second moving portion that moves in conjunction with the third pressed portion; and a second detection means for detecting the movement of the second moving portion.

The invention described in claim 8 is the recording material conveying device according to claim 7, wherein a first moving portion that is the moving portion that is interlocked with the first pressed portion and the second pressed portion, and a second moving portion that is interlocked with the third pressed portion are provided so as to be movable in one direction, and a position of the first moving portion in the one direction is different from a position of the second moving portion in the one direction in a state where the first pressed portion, the second pressed portion, and the third pressed portion are not pressed by the recording material.

The invention described in claim 9 is the recording material conveying device according to claim 7, wherein a first moving portion that is the moving portion that moves in conjunction with the first pressed portion and the second pressed portion, and a second moving portion that moves in conjunction with the third pressed portion are provided so as to be movable in one direction, and a position in the one direction of a detection position where the first moving portion is detected by the first detecting member that detects movement of the first moving portion is different from a position in the one direction of a detection position where the second moving portion is detected by the second detecting member.

The invention described in claim 10 is an image forming apparatus including: an image forming unit that forms an image on a recording material; and a recording material conveying device configured to convey a recording material, the recording material conveying device including the recording material conveying device according to any one of claims 1 to 9.

The invention described in claim 11 is an image forming apparatus including: a first pressed member which is pressed by the conveyed recording material and moves; a second pressed member which is arranged at a position different from the first pressed member in the width direction of the recording material being conveyed, and which is pressed by the recording material being conveyed and moves; a moving member configured to move in conjunction with both the first pressed member and the second pressed member when at least one of the first pressed member and the second pressed member is pressed by a recording material; and a detecting member that detects movement of the moving member.

[ Effect of the invention ]

According to the invention of claim 1, as compared with the case where the detecting member for detecting the moving portion is provided for each moving portion that moves as the recording material reaches the predetermined portion, the number of detecting members for detecting the moving portion that moves as the recording material reaches the predetermined portion can be reduced.

According to the invention of claim 2, as compared with the case where the position of the first pressed portion in one direction and the position of the second pressed portion in one direction match, the load acting on the recording material being conveyed can be reduced.

According to the invention of claim 3, as compared with the case where the position of the first pressed portion in one direction and the position of the second pressed portion in one direction match, it is possible to detect the bulge of the recording material at the end in the width direction of the recording material and to reduce the load acting on the recording material.

According to the invention of claim 4, as compared with the case where the moving portion is disposed closer to the other pressed portion side, the difference between the amount of movement of one of the pressed portions and the amount of movement of the moving portion that moves in association with the movement of the one pressed portion can be reduced.

According to the invention of claim 5, as compared with the case where the moving portion is not provided on the extended line including one of the pressed portions of the plate-like member, the difference between the amount of movement of the one of the pressed portions and the amount of movement of the moving portion that moves along with the movement of the one of the pressed portions can be reduced.

According to the invention of claim 6, the degree of bulging of the end portion of the recording material can be detected with higher accuracy than in the case where the moving portion is not provided on the extension line of the plate-like member located at the opposing portion of the end portion of the recording material.

According to the invention of claim 7, the bulge of the recording material can be detected at a position different from the position where the first pressed portion and the second pressed portion are provided.

According to the invention of claim 8, the number of detection members for detecting the bulging state of the recording material can be reduced as compared with a case where the position of the first moving portion in one direction and the position of the second moving portion in one direction match.

According to the invention of claim 9, the number of the detection means for detecting the bulging state of the recording material can be reduced as compared with a case where the position in one direction of the detection position of the first moving portion detected by the first detection means and the position in one direction of the detection position of the second moving portion detected by the second detection means coincide with each other.

According to the invention of claim 10, as compared with the case where the detecting member for detecting the moving portion is provided for each moving portion that moves as the recording material reaches the predetermined portion, the number of detecting members for detecting the moving portion that moves as the recording material reaches the predetermined portion can be reduced.

According to the invention of claim 11, as compared with the case where the detecting member that detects the moving member is provided for each moving member that moves as the recording material reaches the predetermined portion, the number of detecting members that perform detection of the moving member that moves as the recording material reaches the predetermined portion can be reduced.

Drawings

Fig. 1 is an overall configuration diagram of an image forming apparatus.

Fig. 2 is a diagram illustrating the configuration of the control unit.

Fig. 3 is a diagram illustrating the sheet detecting device.

Fig. 4 is a perspective view of the sheet detecting device as viewed from the direction of arrow IV in fig. 3.

Fig. 5 (a) and 5 (B) are views illustrating the first to third pressed portions and the first to third moving portions.

Fig. 6 is a view of the sheet detecting device as viewed from the direction indicated by arrow VI in fig. 3.

Fig. 7 (a) and 7 (B) are views showing the states of the respective parts when "the swelling of the sheet P is small".

Fig. 8 is a diagram showing a judgment table.

Fig. 9 (a) and 9 (B) are views showing the states of the respective parts when "the swelling of the sheet P is large".

Fig. 10 (a) and 10 (B) are views showing the state of each part when the sheet P is unevenly raised.

Fig. 11 (a) and 11 (B) are views showing the state of each part when the sheet P is unevenly raised.

Fig. 12 (a) and 12 (B) are views showing the state of each part when the sheet P is unevenly raised.

Fig. 13 (a) and 13 (B) are views showing the state of each part when the sheet P is unevenly raised.

Fig. 14 is a diagram showing a comparative example.

Fig. 15 (a) and 15 (B) are diagrams showing other arrangement examples of the first detection position and the second detection position.

[ description of symbols ]

1: image forming apparatus with a toner supply device

10: image forming apparatus with a toner cartridge

400: paper sheet conveying device

600: paper detecting device

611: first pressed part

612: second pressed part

710: a first moving part

P: paper sheet

S1: first detecting sensor

S2: second detection sensor

Detailed Description

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

Fig. 1 is an overall configuration diagram of an image forming apparatus 1. Incidentally, fig. 1 is a view when the image forming apparatus 1 is viewed from the front side (front surface side) of the image forming apparatus 1.

The image forming apparatus 1 includes an image forming section 10 as an example of an image forming means. The image forming section 10 performs image formation on a sheet P as an example of a recording material based on image data of each color.

Further, the image forming apparatus 1 is provided with a sheet conveying device 400 for conveying the sheet P.

The paper conveyance device 400, which is an example of a recording material conveyance device, conveys the paper P stored in the paper storage unit 1B through the secondary transfer unit T and the fixing device 40, and finally conveys the paper P to the paper loading unit 1E.

Here, the paper conveyance device 400 is provided with the conveyance roller 52 and the discharge roller 500, and the paper P is conveyed by the paper conveyance device 400 using the conveyance roller 52 and the discharge roller 500.

The image forming apparatus 1 is provided with a control unit 30 and an image processing unit 35.

The control unit 30 controls each functional unit provided in the image forming apparatus 1. The image processing unit 35 performs image processing on image data from a Personal Computer (PC) 3, an image reading device 4, or the like.

As shown in fig. 2 (a diagram explaining the configuration of the control Unit 30), the control Unit 30 is provided with a Central Processing Unit (CPU) 401, a Random Access Memory (RAM) 402, a Read Only Memory (ROM) 403, a storage device 404 including a hard disk (hard disk), and the like, which are examples of a Processor (Processor).

The ROM403 and the storage device 404 store programs executed by the CPU 401. The CPU401 reads out a program stored in the ROM403 or the storage device 404, and executes the program with the RAM402 set as a work area.

Various functions are realized by the CPU401 executing programs stored in the ROM403 or the storage device 404.

Here, the program executed by the CPU401 may be provided to the image forming apparatus 1 in a state of being stored in a computer-readable recording medium such as a magnetic recording medium (magnetic tape, magnetic disk, or the like), an optical recording medium (optical disk, or the like), an magneto-optical recording medium, or a semiconductor memory. The program executed by the CPU401 may be provided to the image forming apparatus 1 by using a communication method such as the Internet (Internet).

In the present embodiment, the processor is a processor in a broad sense, and includes a general-purpose processor (e.g., a Central Processing Unit (CPU)) or a special-purpose processor (e.g., a Graphics Processing Unit (GPU), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Programmable logic device, or the like).

Moreover, the actions of the processors may be performed not only by one processor but also by a plurality of processors located at physically separate locations in cooperation. The order of the operations of the processor is not limited to the order described in the present embodiment, and may be changed as appropriate.

The image forming apparatus 1 is further explained with reference to fig. 1.

The image forming unit 10 is provided with four image forming units 11Y, 11M, 11C, and 11K (hereinafter, also referred to collectively simply as "image forming units 11") arranged in parallel at a fixed interval.

Each image forming unit 11 is configured similarly except for the toner stored in the developer 15. Each image forming unit 11 forms a toner image (image) of Yellow (Y), Magenta (M), Cyan (C), and blacK (blacK, K).

Each of the image forming units 11 includes a photosensitive drum 12, a charger 200 for charging the photosensitive drum 12, and a Light Emitting Diode (LED) Print Head (LPH) 300 for exposing the photosensitive drum 12.

The photoconductive drum 12 is charged by the charger 200. Further, the photosensitive drum 12 is exposed to light by the LPH300, and an electrostatic latent image is formed on the photosensitive drum 12.

Further, each image forming unit 11 is provided with a developing unit 15 that develops an electrostatic latent image formed on the photosensitive drum 12, and a cleaner (not shown) that cleans the surface of the photosensitive drum 12.

The image forming portion 10 is provided with an intermediate transfer belt 20 to which the toner images of the respective colors formed on the photosensitive drums 12 are transferred, and a primary transfer roller 21 which sequentially transfers (primary transfer) the toner images of the respective colors formed on the photosensitive drums 12 to the intermediate transfer belt 20.

The image forming section 10 is provided with a secondary transfer roller 22 for collectively transferring (secondary transfer) the toner image transferred onto the intermediate transfer belt 20 to the paper P, and a fixing device 40 for fixing the toner image transferred onto the paper P to the paper P.

In the present embodiment, a paper detection device 600 for detecting the paper P is provided downstream of the secondary transfer roller 22 and upstream of the fixing device 40.

The fixing device 40 includes a fixing belt module 41 including a heat source and a pressure roller 46.

The fixing belt module 41 is disposed on the right side of the sheet transport path R1 in the figure. The pressure roller 46 is disposed on the left side of the sheet transport path R1 in the figure. Further, the pressure roller 46 is pressed against the fixing belt module 41.

The fixing belt module 41 includes a film-like fixing belt 411 that contacts the sheet P. The fixing belt 411 is a fixing member used for fixing a toner image (image) on the sheet P to the sheet P.

The fixing belt 411 includes, for example: a release layer which is positioned at the outermost layer and is in contact with the paper P; an elastic layer located on one inner side of the release layer; and a base layer supporting the elastic layer.

The fixing belt 411 is formed in an endless shape and is rotatably provided, and rotates clockwise in the drawing. In other words, the fixing belt 411 is formed in a loop-free shape and moves circularly along a predetermined path.

The fixing belt 411 contacts the sheet P conveyed from below in the figure. More specifically, the fixing belt 411 has an outer peripheral surface 411B, and the outer peripheral surface 411B contacts the paper P.

Further, a portion of the fixing belt 411 that contacts the paper P moves together with the paper P. Further, the fixing belt 411 sandwiches the paper P together with the pressure roller 46, and presses and heats the paper P.

Further, in the fixing belt module 41, a heat source for heating the fixing belt 411 is provided inside the fixing belt 411.

The pressure roller 46, which is an example of a pressure member, is disposed on the left side of the paper conveyance path R1 in the drawing. The pressure roller 46 is pressed against the outer peripheral surface 411B of the fixing belt 411, and presses the sheet P passing between the fixing belt 411 and the pressure roller 46.

The pressure roller 46 is rotated counterclockwise in the drawing by a motor not shown. When the pressure roller 46 rotates in the counterclockwise direction, the fixing belt 411 receives a driving force from the pressure roller 46 and rotates in the clockwise direction.

Here, in the present embodiment, the fixing device 40 also has a function of conveying the paper P conveyed from the upstream side to the downstream side, and the fixing device 40 fixes the toner image on the paper P while the paper P is being conveyed.

In the present embodiment, the conveyance speed of the paper P in the fixing device 40 is changed. More specifically, in the present embodiment, the speed of conveyance of the paper P by the fixing device 40 is changed by changing the rotational speed of the pressure roller 46.

In the image forming apparatus 1, the image processing unit 35 performs image processing on image data from the PC3 or the image reading apparatus 4, and the image data subjected to the image processing is supplied to each image forming unit 11.

In the image forming unit 11K for black (K), for example, the photoconductive drum 12 is charged by the charger 200 while rotating in the direction of the arrow a, and is exposed by the LPH300 that emits light based on image data sent from the image processing unit 35.

Thereby, an electrostatic latent image relating to the image of black (K) color is formed on the photosensitive drum 12. The electrostatic latent image formed on the photosensitive drum 12 is developed by the developing unit 15, and a black (K) toner image is formed on the photosensitive drum 12.

Similarly, toner images of yellow (Y), magenta (M), and cyan (C) colors are formed in the image forming unit 11Y, the image forming unit 11M, and the image forming unit 11C.

The toner images of the respective colors formed by the respective image forming units 11 are sequentially electrostatically attracted to the intermediate transfer belt 20 moving in the arrow B direction by the primary transfer roller 21, and a toner image formed by superimposing the toner images of the respective colors is formed on the intermediate transfer belt 20.

The toner image formed on the intermediate transfer belt 20 is conveyed to a portion (secondary transfer portion T) where the secondary transfer roller 22 is located, along with the movement of the intermediate transfer belt 20.

Then, the sheet P is supplied from the sheet storage portion 1B to the secondary transfer portion T in accordance with the timing at which the toner image is conveyed to the secondary transfer portion T.

In the secondary transfer section T, the toner image on the intermediate transfer belt 20 is electrostatically transferred collectively to the conveyed paper P by the transfer electric field formed by the secondary transfer roller 22.

Subsequently, the paper P on which the toner image is electrostatically transferred is peeled off from the intermediate transfer belt 20 and conveyed to the fixing device 40.

In the present embodiment, the paper P is detected by the paper detection device 600 while the paper P is being conveyed from the intermediate transfer belt 20 toward the fixing device 40.

In the fixing device 40, the paper P is sandwiched between the fixing belt module 41 and the pressure roller 46. Specifically, the sheet P is sandwiched between the fixing belt 411 that circulates in the clockwise direction and the pressure roller 46 that rotates in the counterclockwise direction.

Thereby, the paper P is pressed and heated, and the toner image on the paper P is fixed to the paper P. The fixed paper P is then conveyed to the paper stacking unit 1E by the discharge rollers 500.

Fig. 3 is a diagram illustrating the sheet detecting device 600.

In the paper sheet detecting apparatus 600 of the present embodiment, a pressed portion 610 is provided, and the pressed portion 610 is pressed and moved by the paper sheet P being conveyed.

Further, the paper sheet detecting apparatus 600 is provided with a moving portion 700, the moving portion 700 being provided so as to be interlocked with the pressed portion 610, and the moving portion 700 moves when the pressed portion 610 is pressed by the paper sheet P.

Further, the paper sheet detecting device 600 is provided with a guide member 498 for guiding the conveyed paper sheet P to the downstream side, and in the present embodiment, a pressed portion 610 is provided on the paper sheet conveying path R1 side with respect to the guide member 498.

In the present embodiment, similarly, a second guide member 499 for guiding the conveyed sheet P to the downstream side is provided at the facing position of the guide member 498.

In the present embodiment, a guide member 498, a moving unit 700, and a detection sensor S (described later) are provided on one side RX of the paper conveyance path R1, and a second guide member 499 is provided on the other side RY of the paper conveyance path R1.

In the present embodiment, the moving portion 700 is provided on the opposite side of the pressed portion 610 with the guide member 498 interposed therebetween.

Further, in the present embodiment, a detection sensor S is provided as an example of a detection means, and the detection sensor S detects the movement of the moving unit 700.

Here, in the present embodiment, as described with reference to fig. 4, a plurality of pressed portions 610, moving portions 700, and detection sensors S are provided.

Fig. 4 is a perspective view of the sheet detecting device 600 as viewed from the direction of arrow IV in fig. 3.

In the present embodiment, three pressed portions 610, i.e., the first pressed portion 611 to the third pressed portion 613, are provided as the pressed portions 610.

Here, the first to third pressed portions 611 to 613 are arranged at positions different from each other in the width direction of the sheet P being conveyed.

Further, in the present embodiment, three moving units, i.e., the first moving unit 710 to the third moving unit 730, are provided as the moving unit 700.

The first moving portion 710 (an example of a first moving portion) and the third moving portion 730 (an example of a third moving portion) are provided so as to be interlocked with both the first pressed portion 611 (an example of a first pressed portion) and the second pressed portion 612 (an example of a second pressed portion), and when at least one of the first pressed portion 611 and the second pressed portion 612 is pressed by the paper P, the first moving portion 710 and the third moving portion 730 move.

The second moving portion 720 (an example of a second moving portion) is provided to be interlocked with the third pressed portion 613 (an example of a third pressed portion), and the second moving portion 720 moves when the third pressed portion 613 is pressed by the paper P.

In the present embodiment, a connecting portion 650 that connects the first pressed portion 611 and the second pressed portion 612 is provided. The connecting portion 650 is formed as a round bar-shaped member and is disposed so as to extend in the width direction of the sheet P being conveyed.

In the present embodiment, the first pressed portion 611, the second pressed portion 612, the first moving portion 710, and the third moving portion 730 are fixed to the connecting portion 650. Here, a gap G is provided between the first moving part 710 and the third moving part 730.

The first moving part 710 and the third moving part 730 are arranged on the left side in the figure than the connecting part 650, and the first pressed part 611 is arranged on the right side in the figure than the connecting part 650.

The connection portion 650 is rotatably supported by a main body portion (not shown) of the paper sheet detection device 600. More specifically, both ends of the round bar-shaped connecting portion 650 in the longitudinal direction are supported, and further, the rotation in the circumferential direction is possible.

In the present embodiment, a biasing member (not shown) is provided for biasing the connecting portion 650 in the clockwise direction in the figure, and the first pressed portion 611 and the second pressed portion 612 are projected toward the paper conveyance path R1 (see fig. 3) by the biasing member.

A rod-like member 660 extending in the width direction of the paper P is provided on the third pressed portion 613 side. In the present embodiment, the rod-shaped member 660 supports the third pressed portion 613 and the second moving portion 720.

The second moving portion 720 is disposed on the left side in the figure with respect to the rod-shaped member 660, and the third pressed portion 613 is disposed on the right side in the figure with respect to the rod-shaped member 660.

The rod-shaped member 660 is rotatably provided, similarly to the connection portion 650.

Further, in the present embodiment, a biasing member (not shown) is provided for biasing the rod-like member 660 clockwise in the figure, and the third pressed portion 613 protrudes toward the paper conveyance path R1 (see fig. 3).

Further, in the present embodiment, the first detection sensor S1 as an example of the first detection means is provided as the detection sensor S, and the first detection sensor S1 detects the movement of the first moving unit 710 and the third moving unit 730.

In the present embodiment, the second detection sensor S2 as an example of the second detection means is provided as the detection sensor S, and the second detection sensor S2 detects the movement of the second moving unit 720.

Each of the first detection sensor S1 and the second detection sensor S2 includes a so-called transmissive sensor, and includes a light source 605 that emits light and a light receiving unit 606 that receives light from the light source 605.

In the present embodiment, the first moving unit 710, the second moving unit 720, and the third moving unit 730 pass between the light source 605 and the light receiving unit 606, and thereby the first detection sensor S1 detects the first moving unit 710 and the third moving unit 730, and the second detection sensor S2 detects the second moving unit 720.

Here, in the present embodiment, when the first moving unit 710 and the third moving unit 730 are positioned between the light source 605 and the light receiving unit 606 of the first detection sensor S1, the light emitted from the light source 605 is blocked, and at this time, the first detection sensor S1 is turned off.

When the first moving unit 710 and the third moving unit 730 are not positioned between the light source 605 and the light receiving unit 606 of the first detection sensor S1, the light emitted from the light source 605 reaches the light receiving unit 606, and the first detection sensor S1 is turned on.

In the present embodiment, when the second moving unit 720 is positioned between the light source 605 and the light receiving unit 606 of the second detection sensor S2, the light emitted from the light source 605 is blocked, and at this time, the second detection sensor S2 is turned off.

When the second moving unit 720 is not positioned between the light source 605 and the light receiving unit 606 of the second detection sensor S2, the light emitted from the light source 605 reaches the light receiving unit 606, and at this time, the second detection sensor S2 is turned on.

Fig. 5 (a) and 5 (B) are views illustrating the first to third pressed portions 611 to 613 and the first to third moving portions 710 to 730.

Fig. 5 (a) is a view of the second detection sensor S2, the second moving portion 720, and the third pressed portion 613 as viewed from the direction indicated by the arrow VA in fig. 4.

Fig. 5 (B) is a view of the first detection sensor S1, the first moving part 710, the third moving part 730, the first pressed part 611, and the second pressed part 612 when viewed from the direction indicated by the arrow VB in fig. 4.

In the present embodiment, when the first pressed portion 611, the second pressed portion 612, and the third pressed portion 613 are pressed by the paper P being conveyed, they move toward one side RX of the paper conveyance path R1, as indicated by arrows 5A in fig. 5 (a) and 5 (B).

In the present embodiment, when the first to third pressed portions 611 to 613 are pressed by the paper P being conveyed, they move in one direction, i.e., in the direction indicated by the arrow 5A.

Here, in the present specification, the one direction (the direction indicated by the arrow 5A) which is the direction in which each of the first to third pressed portions 611 to 613 moves is referred to as a pressed portion moving direction 5A.

In the present embodiment, when the first pressed portion 611, the second pressed portion 612, and the third pressed portion 613 move toward the downstream side in the pressed portion moving direction 5A, the first moving portion 710 to the third moving portion 730 move in the direction indicated by the arrow 5X as shown in fig. 5 (a) and 5 (B), respectively.

Hereinafter, in the present specification, the one direction indicated by the arrow 5X is referred to as a moving direction 5X of the moving portion.

Here, in the present embodiment, when the first pressed portion 611 (see fig. 5B) and the second pressed portion 612 move to the downstream side in the pressed portion moving direction 5A, the first moving portion 710 and the third moving portion 730 move to the downstream side in the moving portion moving direction 5X, and the first moving portion 710 and the third moving portion 730 are detected by the first detection sensor S1.

More specifically, the first moving unit 710 and the third moving unit 730 reach the detection position KP (a portion through which light from the light source 605 passes) detected by the first detection sensor S1, and the first moving unit 710 and the third moving unit 730 are detected by the first detection sensor S1.

More specifically, as described above, the first detecting sensor S1 of the present embodiment is a transmission type sensor, and in the present embodiment, the first moving part 710 and the third moving part 730 reach the passing position of the detecting light beam, and the first moving part 710 and the third moving part 730 are detected by the first detecting sensor S1.

In the present embodiment, when the third pressed portion 613 (see fig. 5A) is pressed by the conveyed paper P, the third pressed portion 613 moves downstream in the pressed portion moving direction 5A.

Thereby, the second moving portion 720 moves to the downstream side in the moving portion moving direction 5X. Thereby, the second moving portion 720 is detected by the second detection sensor S2.

More specifically, the second moving part 720 reaches the detection position KP of the second detection sensor S2, and the second moving part 720 is detected by the second detection sensor S2.

More specifically, the second detecting sensor S2 is a transmission type sensor, as in the first detecting sensor S1, and in the present embodiment, the second moving part 720 reaches the passing position of the detecting light beam, and the second moving part 720 is detected by the second detecting sensor S2.

In the present specification, hereinafter, the detection position KP at which the first detection sensor S1 detects the moving part is referred to as a first detection position KP1, and the detection position at which the second detection sensor S2 detects the moving part is referred to as a second detection position KP 2.

In the present embodiment, as shown in fig. 5 (B), the second pressed portion 612 is located on the downstream side of the first pressed portion 611 in the pressed portion moving direction 5A.

In this embodiment, the second pressed portion 612 is located on a side farther from the second guide member 499 (see fig. 3) than the first pressed portion 611.

Further, although the first pressed portion 611 and the second pressed portion 612 rotate (move) in the counterclockwise direction about the connecting portion 650 (see fig. 4), the second pressed portion 612 is located on the downstream side of the first pressed portion 611 in the rotational direction in the present embodiment.

Further, in the present embodiment, the second pressed portion 612 is located closer to the one side RX than the first pressed portion 611.

Further, in the present embodiment, when the positions of the first to third moving portions 710 to 730 in the moving portion moving direction 5X are compared in a state where the sheet P does not contact the first to third pressed portions 611 to 613, the first moving portion 710 is located on the downstream side of the second moving portion 720 as shown in fig. 5 (a) and 5 (B). The third moving unit 730 is located upstream of the second moving unit 720.

In the present embodiment, the second moving portion 720 is located between the first moving portion 710 and the third moving portion 730 in the moving direction 5X of the moving portion in a state where the sheet P does not contact the first to third pressed portions 611 to 613.

Fig. 6 is a view of the sheet detecting device 600 as viewed from the direction indicated by the arrow VI in fig. 3. Incidentally, fig. 6 is a view when the paper detection device 600 is viewed from a direction orthogonal to the conveyance direction of the paper P.

Here, in the present embodiment, when the a 4-sized paper P is conveyed with the short side as the leading end, the first pressed portion 611 is located at a position facing one end portion in the width direction of the a 4-sized paper P.

The second pressed portion 612 is located at a position facing the center portion in the width direction of the a4 size sheet P. The third pressed portion 613 is located at a position facing the other end portion in the width direction of the a 4-sized paper sheet P.

Here, the "width direction" is synonymous with a direction orthogonal to the conveyance direction of the sheet P. Incidentally, the "width direction" is synonymous with the direction in which the side located at the leading end of the sheet P to be conveyed extends.

In the present embodiment, when a paper sheet P of a4 size, which is an example of a paper sheet P of a predetermined specific size, is conveyed in a predetermined posture, the first pressed portion 611 is located at a position facing one end portion in the width direction of the paper sheet P.

More specifically, in the present embodiment, when a sheet P of a4 size, which is an example of a sheet P of a predetermined specific size, is conveyed with the short side leading, the first pressed portion 611 is located at a position facing one end in the width direction of the sheet P.

The second pressed portion 612 is located at a position facing the center portion of the paper P in the width direction, and the third pressed portion 613 is located at a position facing the other end portion of the paper P in the width direction.

Note that, in the present embodiment, the paper P is conveyed on a so-called center reference, and in the present embodiment, the center portion of the paper P in the width direction passes through the facing position of the second pressed portion 612.

Further, one end side in the width direction of the paper P passes through the facing position of the first pressed portion 611. The other end side of the sheet P in the width direction passes through the facing position of the third pressed portion 613.

In the present embodiment, as shown in fig. 5 (B), the second pressed portion 612 is located on the downstream side of the first pressed portion 611 in the pressed portion moving direction 5A.

In the present embodiment, the first pressed portion 611 and the third pressed portion 613 are aligned in the pressed portion moving direction 5A.

In the present embodiment, as shown in fig. 4, the first moving portion 710 and the third moving portion 730 are disposed closer to one of the first pressed portion 611 and the second pressed portion 612.

Specifically, in the present embodiment, the first moving portion 710 and the third moving portion 730 are disposed closer to the first pressed portion 611 side.

In the present embodiment, the first moving portion 710 and the third moving portion 730 are disposed on the side closer to the first pressed portion 611 than the midpoint C of a line segment SB that connects the first pressed portion 611 and the second pressed portion 612 and extends in the width direction of the paper P.

In the present embodiment, as shown in fig. 4, the first moving portion 710 and the third moving portion 730 are provided on the extension line of the plate-like member 615.

More specifically, in the present embodiment, the line indicated by reference numeral 6A in fig. 6 represents the extension line 29 of the plate-like member 615, and in the present embodiment, the first moving unit 710 and the third moving unit 730 are provided on the extension line 29.

Here, in the present embodiment, as shown in fig. 4, a plate-like member 615 is provided at a portion where the first pressed portion 611 is provided.

In the present embodiment, the first moving unit 710 and the third moving unit 730 are provided on the extension line 29 (see fig. 6) of the plate-like member 615.

In the present embodiment, the edge portion 32 of the plate-like member 615 (see fig. 4) on the side through which the sheet P passes (the edge portion 32 on the side of the sheet transport path R1) serves as the first pressed portion 611. In the present embodiment, a part of the plate-like member 615 functions as the first pressed portion 611.

In the present embodiment, the first moving part 710 and the third moving part 730, which are also formed in a plate shape, are positioned on the extension line 29 (see fig. 6) of the plate-shaped member 615.

In the present embodiment, the plate-like member 615, the first moving part 710, and the third moving part 730 are arranged along the thickness direction of the sheet P being conveyed, and in the present embodiment, the first pressed part 611 includes a part of the plate-like member 615 along the thickness direction of the sheet P.

In the present embodiment, the first moving unit 710 and the third moving unit 730 are provided on the extension line 29 of the plate-shaped member 615.

Incidentally, the first moving portion 710, the third moving portion 730, and the plate-like member 615 are located on the same (common) plane extending in the direction orthogonal to the width direction of the sheet P.

To explain further, in the present embodiment, when comparing the positions of the sheets P in the width direction, the installation positions of the first moving unit 710 and the third moving unit 730 are matched with the installation position of the plate-like member 615.

In the present embodiment, the first moving unit 710, the third moving unit 730, and the plate-like member 615 are provided such that when the first moving unit 710, the third moving unit 730, and the plate-like member 615 are projected toward a virtual plane H1 (see fig. 4) extending in the width direction of the paper P in a direction perpendicular to the width direction of the paper P and the virtual plane H1 overlaps with the plate-like member 615.

Similarly, the third pressed portion 613 is provided with a plate-like member 616 (see fig. 4) at a position where the third pressed portion 613 is provided in the present embodiment, and a second moving portion 720 similarly formed in a plate shape is provided on an extension line of the plate-like member 616 in the present embodiment.

Here, the paper sheet detection device 600 of the present embodiment detects that the paper sheet P reaches the portion where the paper sheet detection device 600 is installed. Then, the paper detection device 600 detects the bulge of the paper P that has reached the paper detection device 600.

Here, the detection processing of the bulge of the paper P will be described.

In the present embodiment, two detection sensors S, i.e., the first detection sensor S1 and the second detection sensor S2, are used to detect whether the sheet P is in any of three states, i.e., small bulge of the sheet P, large bulge of the sheet P, and uneven bulge of the sheet P.

Here, the term "uneven swelling of the sheet P" means a state in which the degree of swelling of the sheet P at one end in the width direction of the sheet P is different from the degree of swelling of the sheet P at the other end in the width direction of the sheet P.

Fig. 7 (a) and 7 (B) are views showing the states of the respective parts when "the swelling of the sheet P is small".

In the drawings of fig. 7 and subsequent figures, the second pressed portion 612 is not shown.

Fig. 7 shows the state of each portion when the degree of swelling at one end portion in the width direction of the sheet P is equal to the degree of swelling at the other end portion and the degree of swelling is a first degree smaller than the degree of swelling.

When the swelling degree is the first degree, only the first moving part 710 reaches the first detecting position KP1 of the first detecting sensor S1, and the second moving part 720 does not reach the second detecting position KP2 of the second detecting sensor S2.

At this time, the control section 30 of the present embodiment determines that the bulge of the paper P is small.

In the state shown in fig. 7, the first moving unit 710 reaches the first detection position KP1 of the first detection sensor S1, the first detection sensor S1 is turned off, the second moving unit 720 does not reach the second detection position KP2, and the second detection sensor S2 is turned on.

More specifically, in the present embodiment, as described above, the first moving unit 710 is located on the downstream side of the second moving unit 720 in the moving direction 5X of the moving unit.

Therefore, in the present embodiment, when the degree of swelling at one end portion in the width direction of the sheet P is equal to the degree of swelling at the other end portion and is at the first degree of small degree of swelling, the first moving portion 710 reaches the first detection position KP1, the first detection sensor S1 is turned off, the second moving portion 720 does not reach the second detection position KP2, and the second detection sensor S2 is turned on.

At this time, the control section 30 determines that the bulge of the paper P is small.

More specifically, in the present embodiment, a determination table shown in fig. 8 (a diagram showing the determination table) is registered in the storage device 404 (see fig. 2), and the control unit 30 determines that the bulge of the paper P is small by referring to the determination table.

More specifically, when the first detection sensor S1 is in the off state and the second detection sensor S2 is in the on state, the controller 30 determines that the bulge of the paper P is small, corresponding to the state indicated by reference numeral 8A in fig. 8.

Fig. 9 (a) and 9 (B) are views showing the states of the respective parts when "the swelling of the sheet P is large".

When the bulge of the sheet P is large, the state of each part is as shown in fig. 9.

More specifically, when the bulge of the sheet P is large and the degree of bulge at one end in the width direction of the sheet P is equal to the degree of bulge at the other end, the state of each portion is as shown in fig. 9.

More specifically, when the bulge of the sheet P is large, and the degree of bulge at one end and the degree of bulge at the other end in the width direction of the sheet P are a second degree larger than the first degree, the state of each part is as shown in fig. 9.

When the degree of bulging of the sheet P is the second degree, the first moving part 710 exceeds the first detection position KP1, while the second moving part 720 reaches the second detection position KP 2. At this time, the control section 30 determines that the bulge of the paper P is large.

Incidentally, when the bulge of the sheet P is at the second level, the first detection sensor S1 becomes on state, and the second detection sensor S2 becomes off state. At this time, the control section 30 determines that the bulge of the paper P is large, corresponding to the state indicated by reference numeral 8B in fig. 8.

In the present embodiment, when the paper P is not uniformly raised, for example, when the degree of the raising of one end portion of the paper P in the width direction is a second degree and the raising of the other end portion of the paper P in the width direction is a third degree larger than the second degree, the states of the respective portions are as shown in fig. 10 (a diagram showing the states of the respective portions when the paper P is not uniformly raised).

At this time, the first detection sensor S1 is turned on, and the second detection sensor S2 is turned on.

At this time, the control section 30 determines that the paper P is not uniformly raised, corresponding to the state indicated by reference numeral 8D in fig. 8.

When the degree of the bulge of the sheet P is not uniform, for example, when the degree of the bulge of one end portion of the sheet P in the width direction is a second degree and the degree of the bulge of the other end portion of the sheet P in the width direction is a first degree, the states of the respective portions are as shown in fig. 11 (a diagram showing the states of the respective portions when the bulge of the sheet P is not uniform).

At this time, the first detection sensor S1 is turned on, and the second detection sensor S2 is turned on.

At this time, the control section 30 determines that the paper P is not uniformly raised, corresponding to the state indicated by reference numeral 8D in fig. 8.

When the bulge of the sheet P is uneven, for example, the bulge degree of the other end portion in the width direction of the sheet P is a second degree, and the bulge degree of the one end portion in the width direction of the sheet P is a third degree, the states of the respective portions are as shown in fig. 12 (a diagram showing the states of the respective portions when the bulge of the sheet P is uneven).

At this time, the first detection sensor S1 is turned off, and the second detection sensor S2 is turned off. More specifically, in the state shown in fig. 12, the third moving unit 730 is located at the first detection position KP1, and the first detection sensor S1 is turned off.

At this time, the control section 30 determines that the paper P is not uniformly raised, corresponding to the state indicated by reference numeral 8C in fig. 8.

Then, when the degree of the bulge of the sheet P is not uniform, for example, the degree of the bulge of the other end portion in the width direction of the sheet P is a second degree, and the degree of the bulge of the one end portion in the width direction of the sheet P is a first degree, the state shown in fig. 13 (a diagram showing the state of each portion when the bulge of the sheet P is not uniform) is obtained.

At this time, the first detection sensor S1 is turned off, and the second detection sensor S2 is turned off.

At this time, the control section 30 determines that the paper P is not uniformly raised, corresponding to the state indicated by reference numeral 8C in fig. 8.

In this embodiment, as described above, the three states of the bulge of the sheet P can be detected by the two detection sensors S.

Fig. 14 is a diagram showing a comparative example.

In this example, four detection sensors S are used to detect three states regarding the bulging of the sheet P.

More specifically, in the present comparative example, the first and second detecting sensors S11 and S12 are provided, and the first and second detecting sensors S11 and S12 are disposed on one end side in the width direction of the sheet P and are different from each other in position in the moving direction 5X of the moving portion.

In the present comparative example, a third detecting sensor S13 and a fourth detecting sensor S14 are provided, and the third detecting sensor S13 and the fourth detecting sensor S14 are disposed on the other end side in the width direction of the sheet P and are different from each other in position in the moving direction 5X of the moving portion.

In the present comparative example, three states are detected using the four detection sensors S.

Specifically, in the present comparative example, for example, when the first moving part 710 is detected by the first detection sensor S11 and the second moving part 720 is detected by the third detection sensor S13, it is determined that "the bulge of the paper P is small".

In the present comparative example, for example, when the first moving part 710 is detected by the second detection sensor S12 and the second moving part 720 is detected by the fourth detection sensor S14, it is determined that "the bulge of the paper P is large".

In the present comparative example, for example, when the first moving part 710 is detected by the first detection sensor S11 and the second moving part 720 is detected by the fourth detection sensor S14, it is determined that "the paper P is not uniformly raised".

For example, when the first moving part 710 is detected by the second detection sensor S12 and the second moving part 720 is detected by the third detection sensor S13, it is determined that "the sheet P is not uniformly raised".

In the present comparative example, the three states of "small bulge of the sheet P", "large bulge of the sheet P" and "uneven bulge of the sheet P" can be detected. However, in the present comparative example, four detection sensors S are required for the detection of the three states.

In contrast, in the present embodiment, the three states of "small bulge of the sheet P", "large bulge of the sheet P", and "uneven bulge of the sheet P" can be detected by the two detection sensors, i.e., the first detection sensor S1 and the second detection sensor S2.

In addition, although the three states are detected by shifting the positions of the first moving unit 710 and the second moving unit 720 in the above description, the three states may be detected by shifting the positions of the first detection position KP1 and the second detection position KP2 without shifting the positions of the first moving unit 710 and the second moving unit 720.

More specifically, the three states may be detected by shifting the position of the first detection position KP1 from the position of the second detection position KP2 in the moving direction 5X, which is the moving direction in which the first to third moving units 710 to 730 move.

More specifically, for example, the three states of "small bulge of the sheet P", "large bulge of the sheet P", and "uneven bulge of the sheet P" may be detected using the configuration shown in fig. 15 (a diagram showing another arrangement example of the first detection position KP1 and the second detection position KP 2).

In the configuration example shown in fig. 15, the position of the first moving unit 710 in the moving direction 5X of the moving unit coincides with the position of the second moving unit 720 in the moving direction 5X of the moving unit.

On the other hand, in the above configuration example, the second detection position KP2 of the second probe sensor S2 is located on the downstream side in the moving direction 5X of the moving portion than the first detection position KP1 of the first probe sensor S1.

In the above configuration example, when "the bulge of the sheet P is small", the first moving part 710 is in the first state of reaching the first detection position KP1 of the first detection sensor S1. Thereby, "the swelling of the sheet P is small" is detected.

In addition, when the "swelling of the sheet P is large", the first moving part 710 is in the second state exceeding the first detection position KP1, and the second moving part 720 reaches the second detection position KP2 of the second detection sensor S2. Thereby, "the bulging of the sheet P is large" is detected.

For example, in the case of "uneven swelling of the sheet P", the sheet P is in a state other than the first state and the second state. Also, in this case, when the other state is detected, "the swelling unevenness of the sheet P" is detected.

Here, in the present embodiment, when the paper P is conveyed and reaches the paper detecting device 600, the paper P contacts any one of the first pressed portion 611 to the third pressed portion 613.

Thus, in the present embodiment, it is detected that the sheet P has reached the installation location of the sheet detection device 600.

Here, in the present embodiment, if the paper sheet P is not detected by the paper sheet detecting device 600 until a predetermined timing, it is determined that a jam of the paper sheet P has occurred, and for example, the conveyance of the paper sheet P is stopped.

Here, in the present embodiment, when a paper sheet P of a4 size or larger is conveyed to the paper sheet detecting device 600, the paper sheet P contacts the first pressed part 611 and the third pressed part 613.

In the present embodiment, as described above, the second pressed portion 612 is located downstream of the first pressed portion 611 in the pressed portion moving direction 5A, and therefore, when a paper sheet P of a size equal to or larger than a4 is conveyed to the paper sheet detecting device 600, the paper sheet P contacts the first pressed portion 611 and the third pressed portion 613.

Thus, in the present embodiment, the arrival of the paper P of the a4 size or larger at the installation location of the paper detector 600 is detected.

In the present embodiment, when a paper sheet P of a4 size or larger is conveyed, the paper sheet P contacts the first pressed portion 611 and the third pressed portion 613, and the first to third moving portions 710 to 730 move.

At this time, in the present embodiment, as described above, the control unit 30 detects the bulging state of the sheet P.

More specifically, the control unit 30 detects, with respect to the conveyed paper P, which of "small bulge of the paper P", "large bulge of the paper P", and "uneven bulge of the paper P" the state of the paper P is.

In the present embodiment, the control unit 30 adjusts the conveyance speed of the paper P in the fixing device 40 based on the detected swelling state.

For example, when detecting "the bulge of the paper P is small", the control unit 30 decreases the conveyance speed of the paper P in the fixing device 40 so that the bulge of the paper P becomes large.

More specifically, when detecting that "the bulge of the paper P is small" and the type of the paper P is a predetermined specific type, the control unit 30 decreases the conveyance speed of the paper P in the fixing device 40 so that the bulge of the paper P is large.

Here, when the conveyance speed of the paper P in the fixing device 40 is reduced, the conveyance amount of the paper P per unit time of the fixing device 40 becomes small. On the other hand, the sheet P is conveyed at a predetermined speed from the upstream side of the fixing device 40. Incidentally, the sheet P is conveyed from the upstream side of the fixing device 40 at the same speed as before.

At this time, the fixing device 40 slows the conveyance of the sheet P, and the sheet P bulges greatly.

For example, when detecting "the swelling of the paper P is large", the control unit 30 increases the conveyance speed of the paper P in the fixing device 40 so that the swelling of the paper P is small.

More specifically, when it is detected that "the bulge of the paper P is large" and the type of the paper P is a predetermined specific type, the control section 30 increases the conveyance speed of the paper P in the fixing device 40 so that the bulge of the paper P is reduced.

For example, when "the paper P is not uniformly raised" is detected, the control unit 30 increases the conveyance speed of the paper P in the fixing device 40 and reduces the raising of the paper P.

In the present embodiment, when a sheet of paper P having a size smaller than a4 size, such as a postcard-size sheet of paper, is transported, the sheet of paper P only contacts the second pressed portion 612.

In the present embodiment, when a sheet P smaller than a specific size such as a4 size (hereinafter referred to as a "small-size sheet P") is conveyed, the small-size sheet P contacts only the second pressed portion 612.

At this time, as described above, the arrival of the small-size paper P at the installation position of the paper sheet detection device 600 is detected.

When the small-sized paper P is conveyed, the small-sized paper P does not contact the first pressed portion 611 and the third pressed portion 613. Therefore, for the small-size paper P, the detection processing regarding the bulging state of the paper P is not performed.

Here, in the present embodiment, as described above, the second pressed portion 612 is located on the downstream side in the pressed portion moving direction 5A than the first pressed portion 611.

Thus, in the present embodiment, compared to the case where the positions of the first to third pressed portions 611 to 613 in the pressed portion moving direction 5A are matched, the load acting on the large-size paper sheet P when paper sheets P having a size equal to or larger than a4 (hereinafter referred to as "large-size paper sheet P") are conveyed is reduced.

Here, although the positions of the first to third pressed portions 611 to 613 may be made to coincide with each other, in this case, the second pressed portion 612 comes into contact with the large-size paper P every time the large-size paper P is conveyed, and the load acting on the large-size paper P increases.

In contrast, if the second pressed portion 612 is located on the downstream side in the pressed portion moving direction 5A than the first pressed portion 611 and the third pressed portion 613 as in the present embodiment, the load acting on the large-size paper P is reduced.

In addition, if the second pressed portion 612 is located on the downstream side in the pressed portion moving direction 5A than the first pressed portion 611 and the third pressed portion 613 as in the present embodiment, it is possible to reduce the load acting on the large-size paper P while detecting the small-size paper P.

In addition, although the case where the large-size paper P does not contact the second pressed portion 612 has been described in the present embodiment, a configuration where the large-size paper P contacts the second pressed portion 612 is not excluded, and a configuration where the large-size paper P contacts the second pressed portion 612 may be employed.

However, in this case as well, it is preferable that the second pressed portion 612 is located on the downstream side of the first pressed portion 611 and the third pressed portion 613 in the pressed portion moving direction 5A, and the contact pressure when the paper P contacts the second pressed portion 612 is smaller than the contact pressure when the paper P contacts the first pressed portion 611 and the third pressed portion 613.

In the present embodiment, the case where the first moving portion 710 and the third moving portion 730 are disposed so as to be offset to the side where the first pressed portion 611 is provided has been described above, but the present invention is not limited to this, and the first moving portion 710 and the third moving portion 730 may be provided on the second pressed portion 612 side, for example, on an extension line of the plate-like member 617 (see fig. 4) provided on the second pressed portion 612 side.

However, when the first moving portion 710 and the third moving portion 730 are provided on the first pressed portion 611 side as in the present embodiment, the detection accuracy at the time of detecting the drum becomes high as described above.

Here, when the first moving part 710 and the third moving part 730 are provided on the second pressed part 612 side, the distance between the first pressed part 611 for detecting the bulge and the first moving part 710 and the third moving part 730 becomes large.

In addition, when the first moving part 710 and the third moving part 730 are provided on the second pressed part 612 side, the connecting part 650 (see fig. 4) having a round bar shape is positioned between the first moving part 710 and the third moving part 730 and the first pressed part 611.

At this time, the movement amount of the first moving portion 710 and the third moving portion 730 may be smaller than the movement amount of the first pressed portion 611 due to twisting or the like of the connecting portion 650.

In addition, a situation may occur in which the amount of movement of the first pressed portion 611 is different from the amounts of movement of the first moving portion 710 and the third moving portion 730.

In this case, the detection accuracy of the bulge may be lowered.

On the other hand, when the first moving portion 710 and the third moving portion 730 are arranged to be offset to the side where the first pressed portion 611 is provided, the influence of the distortion is reduced, and the decrease in the bulge detection accuracy is suppressed.

More preferably, as described above, the first moving portion 710 and the third moving portion 730 are provided on the extension line 29 of the plate-like member 615 provided on the first pressed portion 611, and in this case, the decrease in the bulge detection accuracy is further suppressed. The present invention is not limited to an electrophotographic image forming apparatus, and can be applied to an inkjet (inkjet) image forming apparatus, a thermal printer (thermal printer), or the like.