Recording material conveying device and image forming device

Abstract

A recording material conveying device and an image forming device, which reduce the number of detection components for detecting a moving portion that moves as a recording material reaches a predetermined position, compared to a case where a detection component for detecting the moving portion is provided for each moving portion that moves as a recording material reaches a predetermined position. The recording material conveying device of the present invention includes: a first pressed portion that is pressed and moved by the conveyed recording material; a second pressed portion that is arranged at a position different from the first pressed portion in the width direction of the conveyed recording material and is pressed and moved by the conveyed recording material; a moving portion that is configured to be linked to both the first pressed portion and the second pressed portion, and moves when at least one of the first pressed portion and the second pressed portion is pressed by the recording material; and a detection component that detects the movement of the moving portion.

Description

Technical Field

[0001] The present invention relates to a recording material conveying device and an image forming device. Background Art

[0002] Patent Document 1 discloses a configuration in which a plurality of loop sensors are provided between a transfer unit and a fixing unit along a recording medium direction, and a motor control unit controls a fixing motor based on loop detection results thereof.

[0003] Patent Document 2 discloses a process in which, when the measurement value of any ring sensor exceeds a certain value, the driving speed of the fixing unit is changed or the posture of the conveyance guide is changed, thereby avoiding the problem.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2007-52112

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2011-90092 Summary of the Invention

[0008] [Problems to be solved by the invention]

[0009] In an apparatus for conveying a recording material, a moving portion is provided that moves as the recording material reaches a predetermined location. By detecting the movement of the moving portion, it is possible to detect that the recording material has reached the predetermined location.

[0010] Here, if a plurality of moving parts are provided, and further, detection members for detecting the moving parts are provided corresponding to the respective moving parts, the number of detection members provided should correspond to the number of the moving parts.

[0011] The present invention aims to reduce the number of detection components for detecting a moving portion that moves as a recording material reaches a predetermined position, compared to a case where a detection component for detecting each moving portion that moves as a recording material reaches a predetermined position is provided.

[0012] [Technical means to solve the problem]

[0013] The invention described in Technical Solution 1 is a recording material conveying device, comprising: a first pressed portion, which is pressed and moved by the conveyed recording material; a second pressed portion, which is arranged at a position different from the first pressed portion in the width direction of the conveyed recording material, and is pressed and moved by the conveyed recording material; a moving portion, which is configured to be linked with both the first pressed portion and the second pressed portion, and when at least one of the first pressed portion and the second pressed portion is pressed by the recording material, the moving portion moves; and a detection component, which detects the movement of the moving portion.

[0014] The invention described in Technical Solution 2 is a recording material conveying device according to Technical Solution 1, wherein the first pressed part and the second pressed part move in one direction when pressed by the recording material, and one of the first pressed part and the second pressed part is arranged on the downstream side of the one direction compared to the other pressed part.

[0015] The invention described in Technical Solution 3 is a recording material conveying device according to Technical Solution 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 the opposite portion of the end portion in the width direction of the recording material, and when the recording material reaches the second pressed portion, the second pressed portion is located at the opposite portion of the central portion in the width direction of the recording material, and the second pressed portion is arranged on the downstream side of the one direction compared to the first pressed portion.

[0016] The invention described in claim 4 is the recording material transport device according to claim 1 , wherein the moving portion is arranged closer to one of the first pressed portion and the second pressed portion.

[0017] The invention described in Technical Solution 5 is a recording material conveying device according to Technical Solution 4, wherein one of the pressed parts includes a part of a plate-like component, the plate-like component is arranged along the thickness direction of the recording material being conveyed, and the moving part is arranged on the extension line of the plate-like component.

[0018] The invention described in Technical Solution 6 is a recording material conveying device according to Technical Solution 5, wherein, when a recording material of a specific size is conveyed and the recording material reaches the plate-shaped member, the plate-shaped member is located at the opposite ends of the recording material in the width direction, and the moving part is provided on the extension line of the plate-shaped member, and the plate-shaped member is located at the opposite ends.

[0019] The invention described in Technical Solution 7 is a recording material conveying device according to Technical Solution 1, and further includes: a third pressed portion, which is arranged at a position different from the first pressed portion and the second pressed portion in the width direction of the conveyed recording material, and is pressed and moved by the conveyed recording material; a second moving portion, which moves in conjunction with the third pressed portion; and a second detection component, which detects the movement of the second moving portion.

[0020] The invention described in Technical Solution 8 is a recording material conveying device according to Technical Solution 7, wherein the movable part linked to the first pressed part and the second pressed part, i.e., the first movable part, and the second movable part linked to the third pressed part are configured to be able to move in one direction, and when the first pressed part, the second pressed part and the third pressed part are not pressed by the recording material, the position of the first movable part in the one direction is different from the position of the second movable part in the one direction.

[0021] The invention described in Technical Solution 9 is a recording material conveying device according to Technical Solution 7, wherein the movable part linked to the first pressed part and the second pressed part, i.e., the first movable part, and the second movable part linked to the third pressed part are configured to be able to move in one direction, and the detection position of the first movable part detected by the detection part that detects the movement of the first movable part, i.e., the first detection part, is different from the detection position of the second movable part detected by the second detection part in the one direction.

[0022] The invention described in Technical Solution 10 is an image forming device, comprising: an image forming component for performing image formation on a recording material; and a recording material conveying device for conveying the recording material, wherein the recording material conveying device is composed of the recording material conveying device described in any one of Technical Solutions 1 to 9.

[0023] The invention described in technical solution 11 is an image forming device, comprising: a first pressed component, which is pressed and moved by the conveyed recording material; a second pressed component, which is arranged at a different position from the first pressed component in the width direction of the conveyed recording material, and is pressed and moved by the conveyed recording material; a moving component, which is configured to be linked with both the first pressed component and the second pressed component, and when at least one of the first pressed component and the second pressed component is pressed by the recording material, the moving component moves; and a detection component, which detects the movement of the moving component.

[0024] [Effects of the Invention]

[0025] According to the invention of claim 1 , the number of detection components for detecting the moving portion that moves as the recording material reaches the predetermined position can be reduced compared to the case where a detection component for detecting the moving portion is provided for each moving portion that moves as the recording material reaches the predetermined position.

[0026] According to the invention of claim 2 , the load acting on the conveyed recording material can be reduced compared to a case where the position of the first pressed portion and the position of the second pressed portion in one direction coincide with each other.

[0027] According to the invention of technical solution 3, 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 are consistent, it is possible to detect the bulge of the recording material at the width direction end of the recording material and reduce the load acting on the recording material.

[0028] According to the invention of claim 4 , compared with a case where the moving portion is arranged closer to the other pressed portion, the difference between the movement amount of one pressed portion and the movement amount of the moving portion accompanying the movement of the one pressed portion can be reduced.

[0029] According to the invention of technical solution 5, compared with the case where the moving part is not provided on the extension line of one of the pressed parts including the plate-shaped member, the difference between the movement amount of one of the pressed parts and the movement amount of the moving part that moves along with the movement of one of the pressed parts can be reduced.

[0030] 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 when the moving portion is not provided on the extension line of the plate-shaped member located at a portion facing the end portion of the recording material.

[0031] According to the invention of claim 7 , the swelling of the recording material can be detected at a location different from the locations where the first pressed portion and the second pressed portion are provided.

[0032] According to the invention of claim 8 , the number of detection components for detecting the swelling state of the recording material can be reduced compared to a case where the position of the first moving portion in one direction coincides with the position of the second moving portion in one direction.

[0033] According to the invention of technical solution 9, compared with the situation where the detection position of the first movable part detected by the first detection component in one direction and the detection position of the second movable part detected by the second detection component in one direction are consistent, the number of detection components used for detecting the bulging state of the recording material can be reduced.

[0034] According to the invention of technical solution 10, the number of detection components for detecting the moving parts that move as the recording material reaches the predetermined position can be reduced compared to the case where a detection component for detecting the moving part is provided for each moving part that moves as the recording material reaches the predetermined position.

[0035] According to the invention of technical solution 11, compared with the case where a detection component is set for each moving component that moves as the recording material reaches a predetermined position, the number of detection components that detect the moving components that move as the recording material reaches a predetermined position can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a diagram showing the overall structure of an image forming apparatus.

[0037] Figure 2 It is a diagram illustrating the configuration of the control unit.

[0038] Figure 3 It is a diagram for explaining a paper detection device.

[0039] Figure 4 It is from Figure 3 A three-dimensional diagram of the paper detection device when viewed in the direction of arrow IV.

[0040] Figure 5 (A) and Figure 5 (B) is a diagram illustrating the first to third pressed portions and the first to third moving portions.

[0041] Figure 6 It is from Figure 3 The figure shows the paper detection device when observing the direction indicated by arrow VI.

[0042] Figure 7 (A) and Figure 7 (B) is a diagram showing the states of the various components when "the swelling of the paper P is small".

[0043] Figure 8 This is a diagram showing a judgment table.

[0044] Figure 9 (A) and Figure 9 (B) is a diagram showing the states of the various components when "the bulge of the paper P is large".

[0045] Figure 10 (A) and Figure 10 (B) is a diagram showing the state of each part when the bulge of the paper P is uneven.

[0046] Figure 11 (A) and Figure 11(B) is a diagram showing the state of each part when the bulge of the paper P is uneven.

[0047] Figure 12 (A) and Figure 12 (B) is a diagram showing the state of each part when the bulge of the paper P is uneven.

[0048] Figure 13 (A) and Figure 13 (B) is a diagram showing the state of each part when the bulge of the paper P is uneven.

[0049] Figure 14 It is a diagram showing a comparative example.

[0050] Figure 15 (A) and Figure 15 (B) is a diagram showing another arrangement example of the first detection position and the second detection position.

[0051] [Explanation of Symbols]

[0052] 1: Image forming device

[0053] 10: Image forming unit

[0054] 400: Paper conveying device

[0055] 600: Paper detection device

[0056] 611: First pressed part

[0057] 612: Second pressed part

[0058] 710: First moving part

[0059] P: Paper

[0060] S1: First detection sensor

[0061] S2: Second detection sensor DETAILED DESCRIPTION

[0062] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0063] Figure 1 1 is a diagram showing the overall structure of the image forming apparatus 1. Figure 1 This is a diagram when the image forming apparatus 1 is viewed from the front side (front surface side) of the image forming apparatus 1 .

[0064] The image forming apparatus 1 includes an image forming unit 10 as an example of an image forming device. The image forming unit 10 forms an image on a sheet of paper P as an example of a recording material based on image data of each color.

[0065] Furthermore, the image forming apparatus 1 is provided with a paper conveying device 400 that conveys the paper P.

[0066] The paper conveying device 400 , which is an example of a recording material conveying device, conveys the paper P accommodated in the paper accommodating portion 1B through the secondary transfer portion T and the fixing device 40 , and finally conveys the paper P to the paper loading portion 1E.

[0067] Here, the paper conveying device 400 is provided with a conveying roller 52 and a discharge roller 500 . In the paper conveying device 400 , the paper P is conveyed using the conveying roller 52 and the discharge roller 500 .

[0068] Furthermore, the image forming apparatus 1 is provided with a control unit 30 and an image processing unit 35 .

[0069] 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 the personal computer (PC) 3 or the image reading device 4.

[0070] like Figure 2 As shown in the figure illustrating the structure of the control unit 30, the control unit 30 is provided with a central processing unit (CPU) 401 as an example of a processor, a random access memory (RAM) 402, a read-only memory (ROM) 403, and a storage device 404 including a hard disk.

[0071] The ROM 403 and the storage device 404 store programs executed by the CPU 401. The CPU 401 reads the programs stored in the ROM 403 or the storage device 404, and executes the programs using the RAM 402 as a work area.

[0072] The CPU 401 executes programs stored in the ROM 403 or the storage device 404 , thereby realizing various functions.

[0073] Here, the program executed by the CPU 401 can be provided to the image forming apparatus 1 in a state stored in a computer-readable recording medium such as a magnetic recording medium (a magnetic tape, a magnetic disk, etc.), an optical recording medium (an optical disk, etc.), a magneto-optical recording medium, or a semiconductor memory. Furthermore, the program executed by the CPU 401 can also be provided to the image forming apparatus 1 using a communication method such as the Internet.

[0074] In addition, in this embodiment, the so-called processor refers to a processor in a broad sense, including a general-purpose processor (such as a central processing unit (CPU)) or a special-purpose processor (such as a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic element, etc.).

[0075] Furthermore, the operations of the processors may be performed not only by a single processor but also by a plurality of processors located in physically isolated locations in collaboration. Furthermore, the order of the operations of the processors is not limited to that described in this embodiment and may be changed as appropriate.

[0076] Reference Figure 1 The image forming apparatus 1 will be further described.

[0077] The image forming section 10 is provided with four image forming units 11Y, 11M, 11C, and 11K (hereinafter also simply collectively referred to as “image forming units 11 ”) arranged in parallel with a fixed interval therebetween.

[0078] The image forming units 11 have the same configuration except for the toner stored in the developing unit 15. The image forming units 11 form toner images (images) of yellow (Y), magenta (M), cyan (C), and black (K).

[0079] Each image forming unit 11 is provided with 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 .

[0080] The photosensitive drum 12 is charged by the charger 200 . The photosensitive drum 12 is then exposed by the LPH 300 , and an electrostatic latent image is formed on the photosensitive drum 12 .

[0081] Furthermore, each image forming unit 11 is provided with a developing device 15 for developing the electrostatic latent image formed on the photosensitive drum 12 and a cleaner (not shown) for cleaning the surface of the photosensitive drum 12 .

[0082] The image forming section 10 is provided with an intermediate transfer belt 20 to which the color toner images formed by the photosensitive drums 12 are transferred, and a primary transfer roller 21 that sequentially transfers (primarily transfers) the color toner images formed by the photosensitive drums 12 to the intermediate transfer belt 20 .

[0083] The image forming section 10 includes a secondary transfer roller 22 for collectively transferring (secondarily transferring) the toner images transferred onto the intermediate transfer belt 20 onto the paper P, and a fixing device 40 for fixing the toner images transferred onto the paper P onto the paper P.

[0084] Furthermore, in this 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 .

[0085] The fixing device 40 is provided with a fixing belt module 41 including a heat source and a pressure roller 46 .

[0086] The fixing belt module 41 is arranged on the right side of the paper conveyance path R1 in the figure. The pressure roller 46 is arranged on the left side of the paper conveyance path R1 in the figure. The pressure roller 46 is pressed against the fixing belt module 41.

[0087] The fixing belt module 41 includes a film-shaped fixing belt 411 that is in contact with the paper P. The fixing belt 411 is a fixing member used to fix a toner image (image) on the paper P to the paper P.

[0088] The fixing belt 411 includes, for example, a release layer located on the outermost layer and 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.

[0089] The fixing belt 411 is formed into an endless shape and is rotatably provided, rotating in the clockwise direction in the figure. In other words, the fixing belt 411 is formed into an endless shape and circulates along a predetermined path.

[0090] The fixing belt 411 contacts the paper P conveyed from below in the figure. More specifically, the fixing belt 411 has an outer peripheral surface 411B that contacts the paper P.

[0091] The portion of the fixing belt 411 that is in contact with the paper P moves together with the paper P. Furthermore, the fixing belt 411 and the pressure roller 46 sandwich the paper P, thereby applying pressure and heating the paper P.

[0092] Furthermore, in the fixing belt module 41 , a heat source for heating the fixing belt 411 is provided inside the fixing belt 411 .

[0093] The pressure roller 46 , an example of a pressure member, is disposed on the left side of the paper conveyance path R1 in the figure. The pressure roller 46 is pressed against the outer peripheral surface 411B of the fixing belt 411 and presses the paper P passing between the fixing belt 411 and the pressure roller 46 .

[0094] The pressure roller 46 is rotated counterclockwise in the figure by a motor (not shown). When the pressure roller 46 rotates counterclockwise, the fixing belt 411 receives a driving force from the pressure roller 46 and rotates clockwise.

[0095] Here, in this embodiment, the fixing device 40 also has a function of conveying the paper P conveyed from the upstream side to the downstream side. The fixing device 40 fixes the toner image on the paper P while the paper P is being conveyed.

[0096] Furthermore, in this embodiment, the conveyance speed of the paper P in the fixing device 40 is changed. More specifically, in this embodiment, the conveyance speed of the paper P in the fixing device 40 is changed by changing the rotation speed of the pressure roller 46 .

[0097] In the image forming apparatus 1 , the image processing section 35 performs image processing on image data from the PC 3 or the image reading device 4 , and supplies the processed image data to each image forming unit 11 .

[0098] For example, in the black (K) image forming unit 11K, the photosensitive drum 12 is charged by the charger 200 while rotating in the direction of arrow A, and is exposed by the LPH 300 that emits light based on image data sent from the image processing unit 35 .

[0099] As a result, an electrostatic latent image related to a black (K) image is formed on the photosensitive drum 12 . The electrostatic latent image formed on the photosensitive drum 12 is developed by the developing device 15 , thereby forming a black (K) toner image on the photosensitive drum 12 .

[0100] Similarly, in the image forming unit 11Y, the image forming unit 11M, and the image forming unit 11C, toner images of yellow (Y), magenta (M), and cyan (C) are formed.

[0101] The color toner images formed by the image forming units 11 are sequentially electrostatically attracted by the primary transfer rollers 21 to the intermediate transfer belt 20 moving in the direction of arrow B, forming a toner image on the intermediate transfer belt 20 in which the color toners overlap.

[0102] The toner image formed on the intermediate transfer belt 20 is conveyed to a location (secondary transfer portion T) where the secondary transfer roller 22 is located as the intermediate transfer belt 20 moves.

[0103] Then, in conjunction with the timing at which the toner image is conveyed to the secondary transfer portion T, the paper P is supplied to the secondary transfer portion T from the paper storage portion 1B.

[0104] In the secondary transfer portion T, the toner images on the intermediate transfer belt 20 are electrostatically transferred collectively to the conveyed paper P by a transfer electric field formed by the secondary transfer roller 22 .

[0105] Subsequently, the paper P to which the toner image has been electrostatically transferred is peeled off from the intermediate transfer belt 20 and conveyed to the fixing device 40 .

[0106] In addition, in this 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 .

[0107] In the fixing device 40 , the paper P is sandwiched between the fixing belt module 41 and the pressure roller 46 . Specifically, the paper 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.

[0108] As a result, the paper P is pressed and heated, and the toner image on the paper P is fixed to the paper P. Then, the paper P after fixing is conveyed to the paper loading portion 1E by the discharge rollers 500 .

[0109] Figure 3 1 is a diagram illustrating the paper detecting device 600 .

[0110] The paper detecting device 600 of this embodiment is provided with a pressed portion 610 that is pressed by the conveyed paper P and moves.

[0111] Furthermore, the paper detecting device 600 is provided with a moving portion 700 . The moving portion 700 is provided in a manner interlocked with the pressed portion 610 . When the pressed portion 610 is pressed by the paper P, the moving portion 700 moves.

[0112] Furthermore, the paper detection device 600 is provided with a guide member 498 that guides the conveyed paper P to the downstream side. In this embodiment, a pressed portion 610 is provided on the paper conveyance path R1 side relative to the guide member 498 .

[0113] Furthermore, in the present embodiment, a second guide member 499 is similarly provided at a position facing the guide member 498 to guide the conveyed paper P toward the downstream side.

[0114] Here, in this embodiment, a guide member 498 , a moving portion 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 .

[0115] Furthermore, in the present embodiment, the moving portion 700 is provided on the opposite side to the pressed portion 610 with the guide member 498 interposed therebetween.

[0116] Furthermore, in the present embodiment, a detection sensor S is provided as an example of a detection member, and the detection sensor S detects the movement of the moving portion 700 .

[0117] Here, in this embodiment, as follows Figure 4 As described above, the pressed portion 610 , the moving portion 700 , and the detection sensor S are each provided in plural numbers.

[0118] Figure 4 It is from Figure 3 A three-dimensional diagram of the paper detection device 600 when viewed in the direction of arrow IV.

[0119] In the present embodiment, three pressed portions 610 , namely, a first pressed portion 611 to a third pressed portion 613 , are provided as the pressed portions 610 .

[0120] Here, the first to third pressed portions 611 to 613 are arranged so as to be positioned differently from each other in the width direction of the paper P being conveyed.

[0121] Furthermore, in this embodiment, three moving parts, namely, a first moving part 710 to a third moving part 730 are provided as the moving part 700 .

[0122] The first moving part 710 (an example of the first moving part) and the third moving part 730 (an example of the third moving part) are arranged in a manner that is linked with the first pressed part 611 (an example of the first pressed part) and the second pressed part 612 (an example of the second pressed part). When at least one of the first pressed part 611 and the second pressed part 612 is pressed by the paper P, the first moving part 710 and the third moving part 730 move.

[0123] The second moving portion 720 (an example of the second moving portion) is provided in a manner interlocking with the third pressed portion 613 (an example of the third pressed portion). When the third pressed portion 613 is pressed by the paper P, the second moving portion 720 moves.

[0124] Furthermore, in this embodiment, a connecting portion 650 is provided to connect the first pressed portion 611 and the second pressed portion 612. The connecting portion 650 is formed as a round bar-shaped member and is arranged to extend in the width direction of the paper P being conveyed.

[0125] In this 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 portion 710 and the third moving portion 730.

[0126] The first moving portion 710 and the third moving portion 730 are arranged on the left side of the connecting portion 650 in the figure, and the first pressed portion 611 is arranged on the right side of the connecting portion 650 in the figure.

[0127] Furthermore, the connecting portion 650 is rotatably supported by the main body (not shown) of the paper detecting device 600. More specifically, both ends of the rod-shaped connecting portion 650 in the longitudinal direction are supported, thereby enabling circumferential rotation.

[0128] Moreover, in this embodiment, a force applying member (not shown) is provided to apply force to the connecting portion 650 in the clockwise direction in the figure, and the first pressed portion 611 and the second pressed portion 612 are moved toward the paper conveying path R1 (refer to FIG. Figure 3 ) side protrusion.

[0129] A rod-shaped member 660 is provided on the third pressed portion 613 side and extends in the width direction of the paper P. In this embodiment, the third pressed portion 613 and the second moving portion 720 are supported by the rod-shaped member 660 .

[0130] The second moving portion 720 is arranged on the left side of the rod-shaped member 660 in the figure, and the third pressed portion 613 is arranged on the right side of the rod-shaped member 660 in the figure.

[0131] Furthermore, the rod-shaped member 660 is provided in a rotatable state similarly to the connecting portion 650 .

[0132] Furthermore, in this embodiment, a biasing member (not shown) is provided to bias the rod-shaped member 660 in the clockwise direction in the figure, and the third pressed portion 613 is directed toward the paper conveying path R1 (refer to FIG. Figure 3 ) side protrusion.

[0133] Furthermore, in this embodiment, a first detection sensor S1 is provided as the detection sensor S as an example of a first detection member. The first detection sensor S1 detects the movement of the first moving portion 710 and the third moving portion 730 .

[0134] Furthermore, in the present embodiment, a second detection sensor S2 is provided as the detection sensor S as an example of a second detection member. The second detection sensor S2 detects the movement of the second moving portion 720 .

[0135] Each of the first detection sensor S1 and the second detection sensor S2 includes a so-called transmission-type sensor, and includes a light source 605 for emitting light and a light receiving unit 606 for receiving light from the light source 605 .

[0136] In this embodiment, the first moving part 710, the second moving part 720, and the third moving part 730 pass between the light source 605 and the light receiving part 606, thereby detecting the first moving part 710 and the third moving part 730 by the first detection sensor S1 and detecting the second moving part 720 by the second detection sensor S2.

[0137] Here, in this embodiment, when the first movable part 710 and the third movable part 730 are located between the light source 605 and the light receiving part 606 provided in the first detection sensor S1, the light emitted from the light source 605 is blocked, and at this time, the first detection sensor S1 becomes disconnected.

[0138] Moreover, when the first moving part 710 and the third moving part 730 are not located between the light source 605 and the light receiving part 606 provided in the first detection sensor S1, the light emitted from the light source 605 reaches the light receiving part 606, and at this time, the first detection sensor S1 becomes turned on.

[0139] Moreover, in this embodiment, when the second moving part 720 is located between the light source 605 and the light receiving part 606 provided in the second detection sensor S2, the light emitted from the light source 605 is blocked, and the second detection sensor S2 is in the off state.

[0140] When the second moving part 720 is not located between the light source 605 and the light receiving part 606 of the second detection sensor S2, light emitted from the light source 605 reaches the light receiving part 606, and the second detection sensor S2 is turned on.

[0141] Figure 5 (A) and Figure 5 FIG. 1B is a diagram illustrating the first to third pressed portions 611 to 613 and the first to third moving portions 710 to 730 .

[0142] Figure 5 (A) is from Figure 4 FIG. 5 is a diagram showing 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.

[0143] Figure 5 (B) is from Figure 4 FIG. 1 is a diagram showing the first detection sensor S1 , the first moving portion 710 , the third moving portion 730 , the first pressed portion 611 , and the second pressed portion 612 as viewed from the direction indicated by the arrow VB.

[0144] In this embodiment, when the first pressed portion 611, the second pressed portion 612, and the third pressed portion 613 are each pressed by the conveyed paper P, as shown in FIG. Figure 5 (A) and Figure 5 As shown by arrow 5A in FIG. 5B , the paper transport path R1 moves toward one side RX of the paper transport path R1 .

[0145] Furthermore, in the present embodiment, when each of the first to third pressed portions 611 to 613 is pressed by the conveyed paper P, it moves in one direction, ie, the direction indicated by the arrow 5A.

[0146] Here, in this specification, the direction in which each of the first to third pressed portions 611 to 613 moves, that is, the one direction (the direction indicated by the arrow 5A) is referred to as a pressed portion moving direction 5A.

[0147] In this embodiment, when the first pressed portion 611, the second pressed portion 612, and the third pressed portion 613 move toward the downstream side of the pressed portion moving direction 5A, the first moving portion 710 to the third moving portion 730 are each as follows: Figure 5 (A) and Figure 5 As shown in (B), it moves in a direction indicated by arrow 5X.

[0148] Hereinafter, in this specification, the one direction indicated by the arrow 5X is referred to as a moving portion moving direction 5X.

[0149] Here, in this embodiment, when the first pressed portion 611 (refer to Figure 5 (B) When the second pressed part 612 moves toward the downstream side of the pressed part moving direction 5A, the first moving part 710 and the third moving part 730 move toward the downstream side of the moving part moving direction 5X, and the first moving part 710 and the third moving part 730 are detected by the first detection sensor S1.

[0150] More specifically, the first moving part 710 and the third moving part 730 reach the detection position KP (the portion through which the light from the light source 605 passes) detected by the first detection sensor S1 , and are detected by the first detection sensor S1 .

[0151] More specifically, as described above, the first detection sensor S1 of this embodiment is a transmission type sensor. In this embodiment, the first moving part 710 and the third moving part 730 reach the passing position of the detection light, and the first moving part 710 and the third moving part 730 are detected by the first detection sensor S1.

[0152] Moreover, in this embodiment, when the third pressed portion 613 (refer to Figure 5 When the third pressed portion 613 is pressed by the conveyed paper P, it moves toward the downstream side in the pressed portion moving direction 5A.

[0153] As a result, the second moving unit 720 moves toward the downstream side in the moving unit moving direction 5X. As a result, the second moving unit 720 is detected by the second detection sensor S2.

[0154] More specifically, the second moving portion 720 reaches the detection position KP of the second detection sensor S2 , and the second moving portion 720 is detected by the second detection sensor S2 .

[0155] More specifically, the second detection sensor S2 is a transmission type sensor like the first detection sensor S1. In this embodiment, when the second moving part 720 reaches the passing position of the detection light, the second moving part 720 is detected by the second detection sensor S2.

[0156] In this specification, the detection position KP where the first detection sensor S1 detects the moving part is hereinafter referred to as a first detection position KP1, and the detection position where the second detection sensor S2 detects the moving part is hereinafter referred to as a second detection position KP2.

[0157] Moreover, in this embodiment, if Figure 5 As shown in FIG. 5B , in the pressed portion moving direction 5A, the second pressed portion 612 is located on the downstream side of the first pressed portion 611 in the pressed portion moving direction 5A.

[0158] In addition, in this embodiment, the second pressed portion 612 is located farther away from the second guide member 499 than the first pressed portion 611 (see Figure 3 ) side.

[0159] For further explanation, the first pressed portion 611 and the second pressed portion 612 are connected to the connecting portion 650 (see Figure 4 ) is the center and rotates (moves) counterclockwise, but in this embodiment, in the direction of the rotation, the second pressed portion 612 is located on the downstream side of the first pressed portion 611.

[0160] Furthermore, in this embodiment, the second pressed portion 612 is located closer to the one side RX than the first pressed portion 611 .

[0161] Furthermore, in this embodiment, if the paper P does not contact the first pressed portion 611 to the third pressed portion 613, the positions of the first moving portion 710 to the third moving portion 730 in the moving portion moving direction 5X are compared. Figure 5 (A) and Figure 5As shown in FIG. 7B , the first moving portion 710 is located downstream of the second moving portion 720 . Furthermore, the third moving portion 730 is located upstream of the second moving portion 720 .

[0162] In addition, in this embodiment, when the paper P does not contact the first to third pressed portions 611 to 613 , the second moving portion 720 is located between the first moving portion 710 and the third moving portion 730 in the moving portion moving direction 5X.

[0163] Figure 6 It is from Figure 3 FIG when observing the paper detection device 600 in the direction indicated by the arrow VI. Figure 6 This is a diagram when the paper detection device 600 is viewed from a direction perpendicular to the conveyance direction of the paper P.

[0164] Here, in this embodiment, when the A4-sized paper P is conveyed with the short side as the leading edge, the first pressed portion 611 is located at a portion facing one end of the A4-sized paper P in the width direction.

[0165] The second pressed portion 612 is located at a position facing the center portion in the width direction of the A4-sized paper P. The third pressed portion 613 is located at a position facing the other end portion in the width direction of the A4-sized paper P.

[0166] Here, the "width direction" is synonymous with the direction perpendicular to the conveyance direction of the paper P. In addition, the "width direction" is synonymous with the direction in which the side at the leading end of the conveyed paper P extends.

[0167] In this embodiment, when A4-sized paper P, which is an example of paper P of a predetermined specific size, is conveyed in a predetermined posture, the first pressed portion 611 is located at a portion facing one end of the paper P in the width direction.

[0168] More specifically, in this embodiment, when A4-sized paper P, which is an example of a predetermined specific size, is conveyed with its short side leading, the first pressed portion 611 is located at a portion facing one end of the paper P in the width direction.

[0169] The second pressed portion 612 is located at a facing portion at the center portion of the paper P in the width direction, and the third pressed portion 613 is located at a facing portion at the other end portion of the paper P in the width direction.

[0170] In addition, in the present embodiment, the paper P is conveyed based on a so-called center reference. In the present embodiment, the center portion of the paper P in the width direction passes through the position facing the second pressed portion 612 .

[0171] Then, one end side of the paper P in the width direction passes through a position facing the first pressed portion 611 , and the other end side of the paper P in the width direction passes through a position facing the third pressed portion 613 .

[0172] Moreover, in this embodiment, if Figure 5 As shown in FIG. 5B , the second pressed portion 612 is located on the downstream side of the first pressed portion 611 in the pressed portion moving direction 5A.

[0173] Furthermore, in this embodiment, the first pressed portion 611 and the third pressed portion 613 are aligned in position with respect to the pressed portion moving direction 5A.

[0174] Moreover, in this embodiment, if Figure 4 As shown, the first moving portion 710 and the third moving portion 730 are disposed close to one of the first pressed portion 611 and the second pressed portion 612 .

[0175] Specifically, in this embodiment, the first moving portion 710 and the third moving portion 730 are arranged closer to the first pressed portion 611 .

[0176] In addition, in this embodiment, the first moving part 710 and the third moving part 730 are arranged on the side closer to the first pressed part 611 than the midpoint C of the line segment SB, and the line segment SB is a line segment connecting the first pressed part 611 and the second pressed part 612 and extending along the width direction of the paper P.

[0177] Moreover, in this embodiment, if Figure 4 As shown, the first moving portion 710 and the third moving portion 730 are provided on an extension line of the plate-shaped member 615 .

[0178] More specifically, in this embodiment, Figure 6 The line indicated by reference numeral 6A in FIG. 2 represents an extension line 29 of the plate-shaped member 615 . In the present embodiment, the first moving portion 710 and the third moving portion 730 are provided on the extension line 29 .

[0179] Here, in this embodiment, if Figure 4 As shown, a plate-shaped member 615 is provided at the location where the first pressed portion 611 is provided.

[0180] Furthermore, in this embodiment, the first moving portion 710 and the third moving portion 730 are provided on the extension line 29 of the plate-shaped member 615 (see Figure 6 )superior.

[0181] Furthermore, in this embodiment, the plate-shaped member 615 (see Figure 4) on the side where the paper P passes (the edge 32 on the paper conveyance path R1 side) serves as the first pressed portion 611. In addition, in this embodiment, a portion of the plate-shaped member 615 functions as the first pressed portion 611.

[0182] Furthermore, in this embodiment, the first moving portion 710 and the third moving portion 730, which are also formed in a plate shape, are located on the extension line 29 of the plate-shaped member 615 (see Figure 6 )superior.

[0183] In addition, in this embodiment, the plate-shaped member 615, the first moving part 710 and the third moving part 730 are configured in a manner along the thickness direction of the paper P being conveyed. In this embodiment, the first pressed part 611 includes a portion of the plate-shaped member 615 along the thickness direction of the paper P.

[0184] Furthermore, in this embodiment, the first moving portion 710 and the third moving portion 730 are provided on the extension line 29 of the plate-shaped member 615 .

[0185] Incidentally, the first moving portion 710 , the third moving portion 730 , and the plate-shaped member 615 are located on the same (common) plane extending in a direction perpendicular to the width direction of the paper P.

[0186] To further explain, in this embodiment, when comparing the positions in the width direction of the paper P, the installation positions of the first moving portion 710 and the third moving portion 730 are consistent with the installation position of the plate-shaped member 615 .

[0187] In addition, in this embodiment, the first moving part 710, the third moving part 730, and the plate-shaped member 615 are arranged so that when facing the imaginary plane H1 (refer to Figure 4 ) When the first moving part 710, the third moving part 730 and the plate-shaped member 615 are projected, overlap occurs between the first moving part 710, the third moving part 730 and the plate-shaped member 615, and the imaginary plane H1 is oriented in a direction perpendicular to the width direction of the paper P and extends along the width direction of the paper P.

[0188] In addition, the third pressed portion 613 is also provided on the side. In this embodiment, a plate-shaped member 616 is provided at the location where the third pressed portion 613 is provided (see FIG. Figure 4 ), in this embodiment, the second moving portion 720, which is also formed in a plate shape, is provided on the extension line of the plate-shaped member 616.

[0189] Here, the paper detecting device 600 of this embodiment detects that the paper P has reached the location where the paper detecting device 600 is installed. Furthermore, the paper detecting device 600 detects bulging of the paper P that has reached the paper detecting device 600.

[0190] Here, the process of detecting the bulge of the paper P will be described.

[0191] In this embodiment, two detection sensors S, namely the first detection sensor S1 and the second detection sensor S2, are used to detect whether the paper P is in one of the three states of "small bulge of paper P", "large bulge of paper P", and "uneven bulge of paper P".

[0192] Here, “uneven swelling of the paper P” refers to a state in which the swelling degree of the paper P at one end portion in the width direction of the paper P is different from the swelling degree of the paper P at the other end portion in the width direction of the paper P.

[0193] Figure 7 (A) and Figure 7 (B) is a diagram showing the states of the various components when "the swelling of the paper P is small".

[0194] In addition, the Figure 7 In the following figures, illustration of the second pressed portion 612 is omitted.

[0195] Figure 7 : shows the states of each part when the degree of bulging at one end portion in the width direction of the paper P is equal to the degree of bulging at the other end portion and is at a first degree where the bulging degree is small.

[0196] When the swelling degree is the first degree, only the first moving part 710 reaches the first detection position KP1 of the first detection sensor S1 , and the second moving part 720 does not reach the second detection position KP2 of the second detection sensor S2 .

[0197] At this time, the control unit 30 of the present embodiment determines that the swelling of the paper P is small.

[0198] P.S. Figure 7 In the state shown, the first moving part 710 reaches the first detection position KP1 of the first detection sensor S1 and the first detection sensor S1 is turned off, while the second moving part 720 has not reached the second detection position KP2 and the second detection sensor S2 is turned on.

[0199] More specifically, in this embodiment, as described above, in the moving portion moving direction 5X, the first moving portion 710 is located downstream of the second moving portion 720 .

[0200] Therefore, in this embodiment, when the degree of bulging at one end portion in the width direction of the paper P is equal to the degree of bulging at the other end portion and is at the first degree where the bulging degree is smaller, the first moving portion 710 reaches the first detection position KP1, the first detection sensor S1 becomes disconnected, and the second moving portion 720 does not reach the second detection position KP2, and the second detection sensor S2 becomes connected.

[0201] At this time, the control unit 30 determines that the swelling of the paper P is small.

[0202] More specifically, in this embodiment, in the storage device 404 (refer to Figure 2 ) is registered Figure 8 The control unit 30 refers to the determination table shown in (Diagram showing a determination table) and determines that the bulging of the paper P is small.

[0203] More specifically, when the first detection sensor S1 is in the off state and the second detection sensor S2 is in the on state, it is equivalent to Figure 8 In the state shown by reference numeral 8A, the control unit 30 determines that the swelling of the paper P is small.

[0204] Figure 9 (A) and Figure 9 (B) is a diagram showing the states of the various components when "the bulge of the paper P is large".

[0205] When the bulge of the paper P is large, the states of each part are as follows: Figure 9 shown.

[0206] More specifically, when the bulge of the paper P is large and the bulge degree of one end portion in the width direction of the paper P is equal to the bulge degree of the other end portion, the states of the various portions are as follows: Figure 9 shown.

[0207] More specifically, when the bulge of the paper P is large and the bulge degree of one end portion and the bulge degree of the other end portion in the width direction of the paper P are a second degree greater than the first degree, the states of the various parts are as follows: Figure 9 shown.

[0208] When the bulge of the paper P reaches the second level, the first moving portion 710 exceeds the first detection position KP1, while the second moving portion 720 reaches the second detection position KP2.

[0209] In addition, when the bulge of the paper P reaches the second level, the first detection sensor S1 becomes on and the second detection sensor S2 becomes off. Figure 8 In the state shown by reference numeral 8B, the control unit 30 determines that the bulging of the paper P is large.

[0210] Moreover, in this embodiment, when the bulging of the paper P is uneven, for example, the bulging degree of one end portion in the width direction of the paper P is the second degree, and the bulging degree of the other end portion in the width direction of the paper P is the third degree greater than the second degree, the states of each portion are as follows: Figure 10 (Diagram showing the state of each part when the bulging of the paper P is uneven) is shown.

[0211] At this time, the first detection sensor S1 is turned on, and the second detection sensor S2 is turned on.

[0212] At this time, it is equivalent to Figure 8 In the state shown by reference numeral 8D, the control unit 30 determines that the swelling of the paper P is uneven.

[0213] Furthermore, when the bulging of the paper P is uneven, for example, the bulging degree of one end portion in the width direction of the paper P is the second degree, and the bulging degree of the other end portion in the width direction of the paper P is the first degree, the states of the respective portions are as follows: Figure 11 (Diagram showing the state of each part when the bulging of the paper P is uneven) is shown.

[0214] At this time, the first detection sensor S1 is turned on, and the second detection sensor S2 is turned on.

[0215] At this time, it is equivalent to Figure 8 In the state shown by reference numeral 8D, the control unit 30 determines that the swelling of the paper P is uneven.

[0216] Furthermore, when the bulging of the paper P is uneven, for example, the bulging degree of the other end portion in the width direction of the paper P is the second degree, and the bulging degree of one end portion in the width direction of the paper P is the third degree, the states of the respective portions are as follows: Figure 12 (Diagram showing the state of each part when the bulging of the paper P is uneven) is shown.

[0217] At this time, the first detection sensor S1 is turned off, and the second detection sensor S2 is turned off. Figure 12 In the state shown, the third moving portion 730 is located at the first detection position KP1, and the first detection sensor S1 is in the OFF state.

[0218] At this time, it is equivalent to Figure 8 In the state shown by reference numeral 8C, the control unit 30 determines that the swelling of the paper P is uneven.

[0219] Furthermore, when the bulging of the paper P is uneven, for example, the bulging degree of the other end portion in the width direction of the paper P is the second degree, and the bulging degree of one end portion in the width direction of the paper P is the first degree, Figure 13 (Diagram showing the state of each part when the swelling of the paper P is uneven)

[0220] At this time, the first detection sensor S1 is turned off, and the second detection sensor S2 is turned off.

[0221] At this time, it is equivalent to Figure 8 In the state shown by reference numeral 8C, the control unit 30 determines that the swelling of the paper P is uneven.

[0222] In this embodiment, the two detection sensors S can detect three states of swelling of the paper P.

[0223] Figure 14 It is a diagram showing a comparative example.

[0224] In this example, four detection sensors S are used to detect three states of swelling of the paper P.

[0225] More specifically, in this comparative example, a first detection sensor S11 and a second detection sensor S12 are provided. The first detection sensor S11 and the second detection sensor S12 are arranged on one end side in the width direction of the paper P and at different positions in the moving direction 5X of the moving portion.

[0226] Furthermore, in this comparative example, a third detection sensor S13 and a fourth detection sensor S14 are provided. The third detection sensor S13 and the fourth detection sensor S14 are arranged on the other end side in the width direction of the paper P and at positions different from each other in the moving direction 5X of the moving portion.

[0227] In this comparative example, these four detection sensors S are used to detect three states.

[0228] Specifically, in this comparative example, when the first moving portion 710 is detected by the first detection sensor S11 and the second moving portion 720 is detected by the third detection sensor S13 , it is determined that “the bulging of the paper P is small”.

[0229] In this comparative example, for example, when the first moving portion 710 is detected by the second detection sensor S12 and the second moving portion 720 is detected by the fourth detection sensor S14 , it is determined that “the bulging of the paper P is large”.

[0230] In this comparative example, for example, when the first moving portion 710 is detected by the first detection sensor S11 and the second moving portion 720 is detected by the fourth detection sensor S14 , it is determined that “the bulging of the paper P is uneven”.

[0231] For example, when the first moving portion 710 is detected by the second detection sensor S12 and the second moving portion 720 is detected by the third detection sensor S13 , it is determined that “the bulging of the paper P is uneven”.

[0232] This comparative example can also detect the three states of "small bulging of the paper P", "large bulging of the paper P", and "uneven bulging of the paper P". However, in this comparative example, four detection sensors S are required to detect these three states.

[0233] In contrast, in this embodiment, the first and second detection sensors S1 and S2 can be used to detect three states: "small bulge of the paper P", "large bulge of the paper P", and "uneven bulge of the paper P".

[0234] In addition, in the above, the three states are detected by staggering the positions of the first movable part 710 and the second movable part 720, but the positions of the first movable part 710 and the second movable part 720 can also be kept unchanged, and the three states can be detected by staggering the position of the first detection position KP1 and the position of the second detection position KP2.

[0235] More specifically, the first detection position KP1 and the second detection position KP2 may be offset in the moving direction 5X of the first to third moving parts 710 to 730 to detect three states.

[0236] More specifically, for example, Figure 15 The configuration shown in the figure showing another arrangement example of the first detection position KP1 and the second detection position KP2 is used to detect three states: "small bulging of the paper P", "large bulging of the paper P", and "uneven bulging of the paper P".

[0237] Figure 15 In the configuration example shown, the position of the first moving portion 710 in the moving portion moving direction 5X coincides with the position of the second moving portion 720 in the moving portion moving direction 5X.

[0238] On the other hand, in the above-described configuration example, the second detection position KP2 of the second detection sensor S2 is located downstream of the first detection position KP1 of the first detection sensor S1 in the moving direction 5X of the moving portion.

[0239] In the above configuration example, when the bulge of the paper P is small, the first moving portion 710 reaches the first detection position KP1 of the first detection sensor S1 in the first state.

[0240] When the paper P is greatly bulged, the first moving portion 710 exceeds the first detection position KP1, while the second moving portion 720 reaches the second detection position KP2 of the second detection sensor S2.

[0241] Furthermore, for example, in the case of "uneven swelling of the paper P", another state other than the first state and the second state is present. In this case, when the other state is detected, "uneven swelling of the paper P" is detected.

[0242] Here, in this embodiment, the paper P is conveyed, and when the paper P reaches the paper detection device 600 , the paper P contacts any one of the first to third pressed portions 611 to 613 .

[0243] Thus, in this embodiment, it is detected that the paper P has arrived at the installation location of the paper detection device 600 .

[0244] Here, in this embodiment, if the paper detection device 600 fails to detect the paper P by a predetermined timing, it is determined that a jam of the paper P has occurred, and, for example, the conveyance of the paper P is stopped.

[0245] Here, in this embodiment, when the paper P of A4 size or larger is conveyed to the paper detection device 600 , the paper P contacts the first pressed portion 611 and the third pressed portion 613 .

[0246] In addition, in this embodiment, as described above, the second pressed portion 612 is located on the downstream side of the pressed portion moving direction 5A relative to the first pressed portion 611. Thus, when a paper P larger than A4 size is conveyed to the paper detection device 600, the paper P contacts the first pressed portion 611 and the third pressed portion 613.

[0247] Thus, in this embodiment, the arrival of the paper P of A4 size or larger at the installation location of the paper detection device 600 is detected.

[0248] Furthermore, in this embodiment, when a sheet of paper P having an A4 size or larger is conveyed, the sheet of paper P contacts the first pressed portion 611 and the third pressed portion 613 , and the first to third moving portions 710 to 730 move.

[0249] Furthermore, in this embodiment, the control unit 30 detects the swelling state of the paper P as described above.

[0250] More specifically, the control unit 30 detects whether the state of the conveyed paper P is "small bulging of the paper P", "large bulging of the paper P", or "uneven bulging of the paper P".

[0251] Furthermore, in this embodiment, the control unit 30 adjusts the conveyance speed of the paper P in the fixing device 40 based on the detected swelling state.

[0252] For example, when the control unit 30 detects that “the bulging of the paper P is small”, the control unit 30 reduces the conveyance speed of the paper P in the fixing device 40 so that the bulging of the paper P becomes larger.

[0253] More specifically, when the control unit 30 detects that “bulging of the paper P is small” and the type of the paper P is a predetermined specific type, it reduces the conveying speed of the paper P in the fixing device 40 so that the bulging of the paper P becomes larger.

[0254] Here, when the conveyance speed of the paper P in the fixing device 40 is reduced, the amount of paper P conveyed per unit time by the fixing device 40 decreases. Meanwhile, the paper P is conveyed from the upstream side of the fixing device 40 at a predetermined speed. In other words, the paper P is conveyed from the upstream side of the fixing device 40 at the same speed as before.

[0255] At this time, in the fixing device 40 , the conveyance of the paper P becomes slow, and the bulge of the paper P becomes larger.

[0256] For example, when the control unit 30 detects that “the bulging of the paper P is large”, the control unit 30 increases the conveying speed of the paper P in the fixing device 40 so that the bulging of the paper P is reduced.

[0257] More specifically, when the control unit 30 detects that “the bulging of the paper P is large” and the type of the paper P is a predetermined specific type, the control unit 30 increases the conveying speed of the paper P in the fixing device 40 to reduce the bulging of the paper P.

[0258] For example, when the control unit 30 detects “uneven swelling of the paper P”, it increases the conveyance speed of the paper P in the fixing device 40 to reduce swelling of the paper P.

[0259] Furthermore, in the present embodiment, when paper P of a size smaller than A4 size, such as postcard-sized paper, is conveyed, the paper P contacts only the second pressed portion 612 .

[0260] Incidentally, in the present embodiment, when paper P smaller than a specific size such as A4 size (hereinafter referred to as “small-size paper P”) is conveyed, the small-size paper P contacts only the second pressed portion 612 .

[0261] At this time, as described above, the arrival of the small-sized paper P at the location where the paper detection device 600 is installed is detected.

[0262] When conveying a small-sized paper P, the small-sized paper P does not contact the first pressed portion 611 or the third pressed portion 613. Therefore, the process of detecting the bulging state of the small-sized paper P is not performed.

[0263] Here, in the present embodiment, as described above, the second pressed portion 612 is located on the downstream side of the first pressed portion 611 in the pressed portion moving direction 5A.

[0264] Therefore, in this embodiment, compared with the case where the positions of the first pressed part 611 to the third pressed part 613 in the pressed part moving direction 5A are consistent, when conveying paper P larger than A4 size (hereinafter referred to as "large size paper P"), the load acting on the large size paper P becomes smaller.

[0265] Here, although the positions of the first to third pressed portions 611 to 613 can also be made consistent, in this case, each time a large-size paper P is conveyed, the second pressed portion 612 will contact the large-size paper P, and the load acting on the large-size paper P will increase.

[0266] In contrast, if the second pressed portion 612 is located downstream of the first pressed portion 611 and the third pressed portion 613 in the pressed portion moving direction 5A as in this embodiment, the load acting on the large-size paper P is reduced.

[0267] In addition, if the second pressed portion 612 is located on the downstream side of the pressed portion movement direction 5A compared to the first pressed portion 611 and the third pressed portion 613 as in the present embodiment, it is possible to detect small-size paper P and reduce the load acting on large-size paper P.

[0268] In addition, in this embodiment, the case where the large-size paper P does not contact the second pressed portion 612 is described, but this does not exclude the configuration in which the large-size paper P contacts the second pressed portion 612. A configuration in which the large-size paper P contacts the second pressed portion 612 may also be adopted.

[0269] However, in this case, as described above, it is ideal that the second pressed portion 612 is located downstream of the first pressed portion 611 and the third pressed portion 613 in the pressed portion moving direction 5A, so that 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.

[0270] Moreover, in this embodiment, as described above, the first moving portion 710 and the third moving portion 730 are arranged closer to the side where the first pressed portion 611 is provided. However, the present invention is not limited thereto. The first moving portion 710 and the third moving portion 730 may also be arranged on the side of the second pressed portion 612, for example, on the plate-shaped member 617 provided on the side of the second pressed portion 612 (see Figure 4 ) extension line, etc.

[0271] However, if 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 when detecting swelling is improved as described above.

[0272] Here, if the first moving part 710 and the third moving part 730 are provided on the second pressed part 612 side, the separation distance between the first pressed part 611 for detecting swelling and the first moving part 710 and the third moving part 730 will be increased.

[0273] In addition, if 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. Figure 4 ) is located between the first moving part 710, the third moving part 730 and the first pressed part 611.

[0274] At this time, due to distortion of the connection portion 650 or the like, there is a possibility that the movement amounts of the first moving portion 710 and the third moving portion 730 become smaller than the movement amount of the first pressed portion 611 .

[0275] In addition, a situation may occur where the movement amount of the first pressed portion 611 is different from the movement amounts of the first moving portion 710 and the third moving portion 730 .

[0276] In this case, the bulge detection accuracy may decrease.

[0277] In contrast, if the first moving portion 710 and the third moving portion 730 are arranged to be offset toward the side where the first pressed portion 611 is provided, the influence of the distortion is reduced, and a decrease in the bulge detection accuracy is suppressed.

[0278] In a more preferred embodiment, as described above, the first moving portion 710 and the third moving portion 730 are provided on the extension line 29 of the plate-shaped member 615 provided on the first pressed portion 611. In this case, a decrease in the bulge detection accuracy is further suppressed. The present invention is not limited to electrophotographic image forming apparatuses and is also applicable to image forming apparatuses such as inkjet printers and thermal printers.

Claims

1. A recording material transport device comprising: The first pressed portion is pressed and moved by the recording material being transported; a second pressed portion disposed at a position different from the first pressed portion in the width direction of the transported recording material and moved by being pressed by the transported recording material; a first moving portion configured to be linked to both the first pressed portion and the second pressed portion, and to move when at least one of the first pressed portion and the second pressed portion is pressed by the recording material; a detection component for detecting movement of the first moving part; a third pressed portion disposed at a position different from the first pressed portion and the second pressed portion in the width direction of the transported recording material, and moved by being pressed by the transported recording material; a second moving portion, moving in conjunction with the third pressed portion; as well as a second detecting member for detecting movement of the second moving portion; When recording materials of a specific size are transported, When the recording material reaches the first pressed portion, the first pressed portion and the first moving portion are located at opposing ends of the recording material in the width direction. When the recording material reaches the second pressed portion, the second pressed portion is located at a position facing the center portion in the width direction of the recording material. When the recording material reaches the third pressed portion, the third pressed portion and the second moving portion are located at opposing ends of the recording material in the width direction.

2. The recording material transport device according to claim 1, wherein The first pressed portion and the second pressed portion move in one direction when pressed by the recording material. One of the first pressed portion and the second pressed portion is arranged on a downstream side in the one direction relative to the other pressed portion.

3. The recording material transport device according to claim 2, wherein The second pressed portion is arranged on a downstream side of the first pressed portion in the one direction.

4. The recording material transport device according to claim 1, wherein The first pressed portion includes a portion of a plate-shaped member, and the plate-shaped member included in the first pressed portion is arranged along the thickness direction of the conveyed recording material and along the conveyance direction of the conveyed recording material. The first moving portion is provided on an extension line of the plate-shaped member included in the first pressed portion.

5. The recording material transport device according to claim 4, wherein The third pressed portion includes a portion of a plate-shaped member, and the plate-shaped member included in the third pressed portion is arranged along the thickness direction of the conveyed recording material and along the conveyance direction of the conveyed recording material. The second moving portion is provided on an extension line of the plate-shaped member included in the third pressed portion.

6. The recording material transport device according to claim 1, wherein The first moving portion that is linked to the first pressed portion and the second pressed portion, and the second moving portion that is linked to the third pressed portion are configured to be movable in 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, 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.

7. The recording material transport device according to claim 1, wherein The first moving portion linked to the first pressed portion and the second pressed portion, and the second moving portion linked to the third pressed portion are configured to be movable in one direction. A detection position of the first detecting member detecting movement of the first moving part, that is, a detection position of the first moving part in the one direction is different from a detection position of the second detecting member detecting movement of the second moving part in the one direction.

8. An image forming apparatus comprising: An image forming unit forms an image on a recording material; and a recording material transport device transports the recording material, wherein the recording material transport device includes the recording material transport device according to any one of claims 1 to 7.

Images