Detection device, detection method, image forming apparatus, computer readable medium, and computer program product

Abstract

A detection device, an image forming apparatus, a computer readable medium, and an image forming method are provided. The detection device has a conveyance path through which a medium is conveyed, and a detection section that detects a leading end portion and a trailing end portion of the medium in a state where the medium is stopped from being conveyed and is stretched in a stretching direction along the conveyance path.

Description

Technical Field

[0001] This invention relates to detection apparatus, detection method, image forming apparatus, computer-readable medium, and computer program product. Background Technology

[0002] Japanese Patent No. 4133702 discloses an image forming apparatus, characterized by comprising: an image forming section for forming an image; a paper flipping section for double-sided printing; a guide unit for holding the position of a paper in the paper flipping section; and a paper position holding unit that, when paper with a length in the paper transport direction longer than the transport path in the paper flipping section is being transported, continues to hold the position of the paper by the guide unit from the moment when the entire paper is contained in the transport path and the transport operation stops and the rear end of the paper reaches the flipping start position, and releases the paper when the holding ends at the moment when the next image forming operation can be performed.

[0003] Japanese Patent Application Publication No. 2017-114659 discloses a sheet length measuring device comprising: a rotating body that contacts and rotates in contact with a sheet; a measuring mechanism that measures the rotation amount of the rotating body; and a position detection mechanism disposed on the upstream and downstream sides of the rotating body in the conveying direction of the sheet. The sheet length measuring device is characterized in that the position detection mechanism has a row of detection components arranged with multiple detection components, the position detection mechanism is disposed across the side end in the width direction of the sheet, and is configured to be inclined relative to the conveying direction of the sheet. The sheet length is measured based on the rotation amount of the rotating body measured by the measuring mechanism and the end position of the sheet detected by the position detection mechanism. Summary of the Invention

[0004] The purpose of this invention is to improve the detection accuracy of the front and rear ends of the medium compared to detecting the front and rear ends of the medium in the transport path.

[0005] According to a first aspect of the present invention, a detection device is provided, comprising: a conveying path for conveying a medium; and a detection unit that detects the front and rear ends of the medium in the conveying path when it is stopped from being conveyed and is stretched in a stretching direction along the conveying path.

[0006] According to a second aspect of the present invention, the detection device includes: an upstream conveying section that conveys the medium in the conveying path in the conveying direction and stops the conveying; and a downstream conveying section disposed downstream of the upstream conveying section in the conveying direction, conveying the medium in the conveying path in the conveying direction and stopping the conveying, wherein the upstream conveying section and the downstream conveying section stretch the medium along the stretching direction.

[0007] According to a third aspect of the present invention, the downstream conveying section and the upstream conveying section convey the medium. After the upstream conveying section stops conveying, the downstream conveying section stops conveying, thereby stretching the medium along the stretching direction when the conveying section stops.

[0008] According to a fourth aspect of the present invention, the upstream conveying section or the downstream conveying section has: a first conveying section; and a second conveying section disposed on the upstream side of the conveying direction of the first conveying section.

[0009] According to a fifth aspect of the present invention, the downstream conveying section includes the first conveying section and the second conveying section, wherein the second conveying section and the upstream conveying section convey media with a stretching conveying length less than a predetermined length, and the first conveying section and the upstream conveying section convey media with a stretching conveying length greater than or equal to a predetermined length.

[0010] According to a sixth aspect of the invention, the first conveying section and the second conveying section are rollers that rotate using a common drive source.

[0011] According to a seventh aspect of the present invention, the upstream conveying section or the downstream conveying section changes the tensile force according to the characteristics of the medium.

[0012] According to the eighth aspect of the present invention, the upstream conveying section or the downstream conveying section stops in a manner in which the amount of protrusion of the end of the medium from the upstream conveying section or the downstream conveying section is approximately the same as the length of the medium in the conveying direction, and the medium is conveyed again from the end side where the amount of protrusion is approximately the same.

[0013] According to the ninth aspect of the present invention, the detection unit detects the front and rear ends of a medium when it is stopped from being transported and is stretched in the stretching direction, for a medium whose length in the transport direction is more than a predetermined length; the detection unit does not detect the front and rear ends of a medium whose length in the transport direction is less than a predetermined length.

[0014] According to a 10th aspect of the present invention, the detection device includes: a side end detection unit that detects the side end of the medium when the detection unit detects the front end and the rear end; and a support unit that supports the side end of the medium detected by the side end detection unit.

[0015] According to the eleventh aspect of the present invention, the support portion is arranged along the side end detection portion upstream of the side end detection portion in the conveying direction.

[0016] According to a 12th aspect of the present invention, an image forming apparatus is provided, comprising: an image forming unit that forms an image on a medium; a heating unit that heats the medium on which the image is formed; a transport path for transporting the heated medium; and a detection unit that detects the front and rear ends of the medium in the transport path when the transport has been stopped and the medium is stretched in a stretching direction along the transport path, wherein the detection unit detects the front and rear ends of the medium after the medium has been heated.

[0017] According to a 13th aspect of the present invention, an image forming apparatus is provided, comprising: an image forming unit that forms an image on a medium; a heating unit that heats the medium on which the image is formed; a transport path for transporting the heated medium; and a detection unit that detects the front and rear ends of the medium in the transport path when it is stopped from transporting and is stretched in a stretching direction along the transport path, wherein the detection unit and the heating unit are disposed in different portions of a housing divided into multiple portions.

[0018] According to a 14th aspect of the present invention, in the image forming apparatus of the 13th aspect, the detection unit is disposed below the heating unit.

[0019] According to a 15th aspect of the present invention, an image forming apparatus is provided, comprising: a suction unit that suctions the medium from a medium receiving unit that receives the medium; a delivery unit that delivers the medium suctioned by the suction unit; a detection unit that detects a front end and a rear end of the medium in a delivery path for which the medium delivered by the delivery unit is being transported, wherein the medium is in a state of being stopped and stretched in a stretching direction along the delivery path; and an image forming unit that forms an image on the medium detected by the detection unit, wherein the detection unit detects the front end and the rear end of the medium when the front end and the rear end are disengaged from the delivery unit and the front end and the rear end are located between the delivery unit and the image forming unit.

[0020] According to a 16th aspect of the present invention, an image forming apparatus is provided, comprising: a transport path for transporting a variety of media; a detection device that detects, in the transport path, the front and rear ends of the variety of media in a state where transport has been stopped and they are stretched in a stretching direction along the transport path; and an image forming unit that forms an image on the variety of media based on the detection result of the detection device, wherein the detection device changes the stretching force according to the type of the media.

[0021] According to a 17th aspect of the present invention, a computer-readable medium is provided storing a program for causing a computer to perform processing, wherein the processing includes the step of detecting a front end and a rear end of the medium in a transport path for transporting the medium, wherein the transport is stopped and the medium is stretched in a stretching direction along the transport path.

[0022] According to the 18th aspect of the present invention, a detection method is provided, the detection method comprising the steps of: detecting the front end and the rear end of the medium in a conveying path in which the conveying is stopped and is stretched in a stretching direction along the conveying path.

[0023] (Effect)

[0024] According to the first scheme, the detection accuracy of the front and rear ends of the medium is improved compared to the case of detecting the front and rear ends of the medium in the transport path.

[0025] According to the second scheme, the number of components can be reduced compared to the case where the upstream and downstream conveying sections only have the function of conveying the medium.

[0026] According to the third scheme, compared to the case where, after the upstream and downstream conveying sections simultaneously stop conveying the medium, at least one of the upstream and downstream conveying sections performs an action to stretch the medium, the total action time for stopping and stretching can be reduced.

[0027] According to the fourth scheme, compared with the case where the upstream or downstream conveying section has only a single conveying section, the position of the stretching medium has a higher degree of freedom.

[0028] According to the fifth scheme, compared with the case where the second conveying section and the upstream conveying section also stretch the medium with a conveying direction length of more than a predetermined length, the deflection at the front end of the medium with a conveying direction length of more than a predetermined length can be suppressed.

[0029] According to the sixth scheme, compared to the case where the first conveying unit and the second conveying unit are rollers that rotate using different drive sources, the number of parts can be reduced.

[0030] According to the seventh scheme, compared with the case where the tensile force of the upstream or downstream conveying section is constant, the wrinkling of the medium can be suppressed.

[0031] According to the eighth scheme, compared with the case where the amount of protrusion of the end of the medium from the upstream or downstream conveying section changes depending on the medium, and the medium is conveyed again from the protruding side, the conveying control when conveying the medium again can be simplified.

[0032] According to the above-described scheme 9, compared to the case where the front and rear ends of the medium are always detected regardless of the length of the detection unit in the transport direction of the medium, the number of times the front and rear ends of the medium are detected can be reduced.

[0033] According to the 10th scheme, compared with the case where there is no support for supporting the side end when the side end of the medium is detected at the front end and the rear end of the detection section, the detection accuracy of the side end of the medium is improved.

[0034] According to the 11th solution, compared with the case where the support is arranged on the downstream side of the conveying direction of the side end detection unit, the detection accuracy of the side end of the medium is improved.

[0035] According to the 12th solution, compared with the case where the front and rear ends of the medium being transported are also detected in the transport path for the medium that is being transported to the image forming unit again after heating, the detection accuracy of the front and rear ends of the medium is improved.

[0036] According to the above-described scheme 13, compared with the case where the detection unit and the heating unit are located in the same part of the housing, the thermal influence of the heating unit on the detection unit can be reduced.

[0037] According to the above-mentioned scheme 14, compared with the case where the detection unit is located on the upper side of the heating unit, the thermal influence received by the detection unit from the heating unit can be reduced.

[0038] According to the 15th scheme, compared with the case where the detection unit detects the front and rear ends of the medium at the suction unit, the suction effect on the detection unit from the suction unit can be reduced.

[0039] According to the 16th scheme, compared with the case where image formation is performed based on the results obtained by detecting the front and rear ends of multiple media under a constant tensile force, appropriate image formation can be performed for the type of media.

[0040] According to the 17th scheme, the detection accuracy of the front and rear ends of the medium is improved compared to the case of detecting the front and rear ends of the medium in the transport path.

[0041] According to the 18th scheme, the detection accuracy of the front and rear ends of the medium is improved compared to the case of detecting the front and rear ends of the medium in the transport path. Attached Figure Description

[0042] Figure 1 This is a schematic diagram showing the structure of the image forming apparatus of this embodiment.

[0043] Figure 2 This is a schematic diagram showing the structure of the image forming apparatus in this embodiment when an electrophotographic image forming unit is used.

[0044] Figure 3 This is a schematic diagram showing the structure of the image forming apparatus in this embodiment when the media receiving section is arranged on the side of the transport path.

[0045] Figure 4 This is a perspective view showing the structure of the detection device according to this embodiment.

[0046] Figure 5 This is a perspective view showing the state after the first and second units of the detection device of this embodiment have been disassembled from the main body of the detection device.

[0047] Figure 6 This is a top view showing the structure of the detection device according to this embodiment.

[0048] Figure 7 This is a cross-sectional view used to illustrate the positioning of the rear part of the detection device in this embodiment.

[0049] Figure 8 This is a perspective view illustrating the positioning of the front part of the detection device in this embodiment.

[0050] Figure 9 This is a cross-sectional view used to illustrate the positioning of the front part of the detection device in this embodiment.

[0051] Figure 10 It is shown in Figure 4 The diagram shows a three-dimensional view of the structure in which the opening and closing parts are moved to the open position.

[0052] Figure 11 This is a perspective view of the main body of the detection device of this embodiment, viewed from below.

[0053] Figure 12 This is a top view showing a portion of the structure of the detection device according to this embodiment.

[0054] Figure 13 yes Figure 6 The sectional view along line AA is Figure 12A sectional view along line AA.

[0055] Figure 14 This is a block diagram illustrating an example of the hardware structure of a control device according to this embodiment.

[0056] Figure 15 This is a block diagram illustrating an example of the functional structure of a processor in a control device according to this embodiment.

[0057] Figure 16 This is a side sectional view of the detection device of this embodiment.

[0058] Figure 17 This is a side sectional view of the detection device of this embodiment.

[0059] Figure 18 This is a block diagram illustrating an example of the hardware structure of another control device in this embodiment.

[0060] Figure 19 This is a block diagram illustrating an example of the functional structure of a processor in another control device according to this embodiment.

[0061] Figure 20 This is a timing diagram showing the detection device of this embodiment.

[0062] Figure 21 This is a schematic diagram illustrating a method for measuring the length of the medium in the transport direction in the detection apparatus of this embodiment.

[0063] Figure 22 It is shown in Figure 21 A diagram showing the state of medium flexure in the structure shown.

[0064] Figure 23 This is a schematic diagram illustrating a method for measuring the length in the transport direction and the length in the width direction of a medium in the detection apparatus of this embodiment.

[0065] Figure 24 This is a schematic diagram showing the structure of an image forming apparatus using a delivery mechanism with a suction section.

[0066] Figure 25 This is a schematic diagram showing the structure of a delivery mechanism with a suction section. Detailed Implementation

[0067] Hereinafter, an example of an embodiment of the present invention will be described with reference to the accompanying drawings.

[0068] (Image forming apparatus 10)

[0069] The structure of the image forming apparatus 10 in this embodiment will be explained. Figure 1This is a schematic diagram showing the structure of the image forming apparatus 10 of this embodiment.

[0070] Additionally, the arrow UP in the diagram indicates the top (vertical top) of the device, and the arrow DO indicates the bottom (vertical bottom) of the device. Furthermore, the arrow LH indicates the left side of the device, and the arrow RH indicates the right side. Additionally, the arrow FR indicates the front of the device, and the arrow RR indicates the rear. Since these directions are provided for ease of explanation, the device structure is not limited to these directions. Furthermore, the word "device" is sometimes omitted in the description of each direction. That is, for example, sometimes "above the device" is simply shown as "above".

[0071] Furthermore, in the following descriptions, "up and down direction" is sometimes used to mean "both sides, above and below" or "either side, above and below". "Left and right direction" is sometimes used to mean "both sides, right and left" or "either side, right and left". "Left and right direction" can also be called horizontal or lateral. "Front and back direction" is sometimes used to mean "both sides, front and back" or "either side, front and back". The front and back direction is equivalent to the width direction described later and can also be called horizontal or lateral. Furthermore, the up and down direction, left and right direction, and front and back direction are intersecting directions (specifically, orthogonal directions).

[0072] Furthermore, the "×" symbol within the "○" in the diagram indicates an arrow pointing inwards from the front of the paper. Additionally, the "·" symbol within the "○" in the diagram indicates an arrow pointing inwards from the back of the paper.

[0073] Figure 1 The image forming apparatus 10 shown is an image forming apparatus. Specifically, the image forming apparatus 10 is an inkjet image forming apparatus that uses ink to form an image on a medium P. More specifically, as... Figure 1 As shown, the image forming apparatus 10 includes an image forming apparatus main body 11, a medium receiving section 12, a medium discharging section 13, an image forming section 14, a heating section 19, a conveying mechanism 20, a detection device 30, and a control device 160.

[0074] The following will describe the medium P, the various parts of the image forming apparatus 10, and the image forming operation in the image forming apparatus 10.

[0075] (Medium P)

[0076] Medium P is the object on which an image is formed by the image forming unit 14. Types of medium P include, for example, paper and film. Paper includes, for example, thick paper and coated paper. Film includes, for example, resin film and metal film. In this embodiment, paper is used as medium P, for example. However, the type of medium P is not limited to those described above, and various types of medium P can be used.

[0077] The size (i.e., dimensions) of medium P can be, for example, A3 Nobi or larger, including sizes such as A2, A1, A0, B series, etc. However, the size of medium P is not limited to the sizes mentioned above; various sizes of medium P can be used.

[0078] Here, the length of medium P along the conveying direction is called the conveying direction length. The direction of intersection (specifically, the orthogonal direction) that intersects the conveying direction of medium P is called the width direction, and the length of medium P along the width direction is called the width direction length.

[0079] In addition, in this embodiment, the upstream end of the medium P in the conveying direction is sometimes referred to as the rear end or upstream end. Furthermore, the downstream end of the medium P in the conveying direction is sometimes referred to as the front end or downstream end. Also, the end in the width direction of the medium P is sometimes referred to as the side end.

[0080] (Image forming apparatus main body 11)

[0081] like Figure 1 As shown, the image forming apparatus body 11 is the portion in which the various structural parts of the image forming apparatus 10 are provided. Specifically, for example, the media receiving portion 12, the image forming portion 14, the heating portion 19, the transport mechanism 20, and the detection device 30 are disposed inside the image forming apparatus body 11. The image forming apparatus body 11 has a housing 18 divided into multiple portions 18A and 18B. The media receiving portion 12, the image forming portion 14, and the heating portion 19 are disposed in portion 18A of the housing 18. The detection device 30 is disposed in portion 18B of the housing 18.

[0082] A detection device 30 is detachably mounted on the image forming apparatus body 11. In other words, the detection device 30 can be attached to and removed from the image forming apparatus body 11. The configuration of the detection device 30 will be described later.

[0083] (Media storage section 12)

[0084] The medium receiving section 12 is the part of the image forming apparatus 10 that receives the medium P. The medium P received by the medium receiving section 12 is supplied to the image forming section 14.

[0085] (Media discharge section 13)

[0086] The medium discharge section 13 is the part in the image forming apparatus 10 that discharges the medium P. The medium P, into which the image is formed by the image forming section 14, is discharged into the medium discharge section 13.

[0087] (Image forming unit 14)

[0088] Figure 1 The image forming unit 14 shown is an example of an image forming unit that forms an image on a medium P. Specifically, the image forming unit 14 uses ink to form an image on the medium P. More specifically, as... Figure 1 As shown, the image forming unit 14 includes ejection units 15Y, 15M, 15C, and 15K (hereinafter referred to as 15Y to 15K), a transfer body 16, and a countering member 17 opposite to the transfer body 16.

[0089] In the image forming unit 14, each ejection unit 15Y to 15K ejects droplets of yellow (Y), magenta (M), cyan (C), and black (K) ink onto the transfer body 16, forming an image on the transfer body 16. Furthermore, in the image forming unit 14, the images of each color formed on the transfer body 16 are transferred to a medium P at a transfer position TA between the transfer body 16 and the opposing member 17. Thus, an image is formed on the medium P. The transfer position TA can also be described as the image forming position where the image is formed on the medium P.

[0090] Furthermore, as an example of an image forming unit, the structure is not limited to that of the image forming unit 14. As an example of an image forming unit, it may also be a structure in which each ejection unit 15Y to 15K ejects ink droplets directly to the medium P without passing through the transfer body 16.

[0091] (Image forming unit 214)

[0092] As an example of an image forming unit, such as Figure 2 As shown, an electrophotographic image forming unit 214 that forms an image on a medium P using a toner can also be used.

[0093] like Figure 2 As shown, the image forming unit 214 includes toner image forming units 215Y, 215M, 215C, and 215K (hereinafter referred to as 215Y to 215K), a transfer body 216, and a transfer member 217.

[0094] In the image forming unit 214, each toner image forming unit 215Y to 215K undergoes charging, exposure, development, and transfer processes, forming toner images of yellow (Y), magenta (M), cyan (C), and black (K) on the transfer body 216. The toner images of each color formed on the transfer body 216 are transferred by the transfer member 217 to a medium P at the transfer position TA between the transfer body 216 and the transfer member 217. Thus, an image is formed on the medium P. Therefore, as an example of an image forming apparatus, it can also be an electrophotographic image forming apparatus.

[0095] Alternatively, as an example of an image forming unit, it may be a structure in which each toner image forming unit 215Y to 215K forms a toner image directly on the medium P without passing through the transfer body 216.

[0096] (Heating section 19)

[0097] Figure 1 The heating unit 19 shown is an example of a heating unit that heats the medium P on which an image is formed. As an example, the heating unit 19 uses a heat source (not shown) to heat the medium P in a non-contact manner, thereby drying the ink image.

[0098] As an example of a heating element, it is not limited to the heating element 19 described above. As an example of a heating element, it may also be a device that heats the medium P by contacting it within a range that does not affect the image, and various heating elements may be used.

[0099] In an electrophotographic image forming apparatus having an image forming unit 214, the heating unit 19 functions, for example, as a fixing device that fixes toner images by heating.

[0100] (Conveying mechanism 20)

[0101] The conveying mechanism 20 is a mechanism for conveying the medium P. As an example, the conveying mechanism 20 uses a conveying component 29, such as a conveying roller, to convey the medium P. Alternatively, the conveying component 29 can be a conveyor belt or the like, as long as it is a component that applies a conveying force to the medium P and is capable of conveying the medium P.

[0102] The transport mechanism 20 transports medium P from the medium receiving section 12 to the image forming section 14 (specifically, the transfer position TA). Furthermore, the transport mechanism 20 transports medium P from the image forming section 14 to the heating section 19. Also, the transport mechanism 20 transports medium P from the heating section 19 to the medium discharge section 13. Additionally, the transport mechanism 20 transports medium P from the heating section 19 to the image forming section 14.

[0103] Therefore, the image forming apparatus 10 includes a transport path 21 from the medium receiving section 12 to the image forming section 14, a transport path 22 from the image forming section 14 to the heating section 19, and a transport path 23 from the heating section 19 to the medium discharge section 13. Furthermore, the image forming apparatus 10 also includes a transport path 24 from the heating section 19 to the image forming section 14.

[0104] Transport path 24 is a transport path that returns the medium P on one surface with an image formed thereon to the image forming unit 14 (specifically, the transfer position TA). In addition, transport path 24 is also a transport path that flips the medium P on one surface with an image formed thereon back and forth.

[0105] A portion of transport path 21 and transport path 24 (specifically, the downstream portion in the transport direction) are shared. Therefore, the structure can be understood as follows: transport path 25, which transports medium P from the medium receiving unit 12, is connected to transport path 24, and medium P is supplied from the medium receiving unit 12 to transport path 24. Therefore, the connection position where transport path 25 and transport path 24 are connected can be understood as supply position 25A, where a new medium P from the medium receiving unit 12 is supplied to the image forming unit 14 via transport path 24. In other words, in this embodiment, medium P is supplied from supply position 25A to the image forming unit 14 via transport path 24.

[0106] (Image forming operation in image forming apparatus 10)

[0107] In the image forming apparatus 10, a medium P is conveyed from the medium receiving section 12 to the image forming section 14 (specifically, the transfer position TA) via the transport path 21, and a first image (hereinafter, sometimes referred to as a "front image") is formed on one side (i.e., the front side) of the medium P by the image forming section 14. In the case where an image is formed only on one side of the medium P, the medium P with the front image formed on one side is discharged to the medium discharge section 13 via the heating section 19.

[0108] On the other hand, when images are formed on both sides of the medium P, the medium P with a front image formed on one side is conveyed in the transport path 24 via the heating unit 19, thereby flipping it back to the image forming unit 14 (specifically, the transfer position TA). Then, the image forming unit 14 forms a second image (hereinafter sometimes referred to as a "reverse image") on the other side (i.e., the reverse side) of the heated medium P. That is, the image forming unit 14 performs image forming again. Afterwards, it is discharged to the medium discharge unit 13 via the heating unit 19.

[0109] (Location of media storage section 12)

[0110] like Figure 1As shown, the media receiving section 12 is positioned on the lower side relative to the conveying path 24. Therefore, the media P in the media receiving section 12 is supplied from the lower side to the supply position 25A of the conveying path 24.

[0111] In addition, such as Figure 3 As shown, the media receiving section 12 can also be disposed on the side of the conveying path 24. In this case, the media P in the media receiving section 12 is received from the side ( Figure 3 (On the right side of the middle) it supplies to the supply position 25A of the conveyor path 24. Figure 3 In the structure shown, the media receiving section 12 is positioned to the side of the image forming section 14 (specifically, the transfer position TA). Thus, the media P is supplied to the image forming section 14 (specifically, the transfer position TA) from the side. Furthermore, in Figure 3 The main body 11 of the image forming apparatus is omitted from the illustration.

[0112] (Detection device 30)

[0113] Figure 1 The detection device 30 shown is an example of a detection device for the end of the detection medium P. Figure 4 This is a perspective view showing the structure of the detection device 30. Figure 5 This is a perspective view showing the state after the first unit 31 and the second unit 32 have been removed from the main body 40 of the detection device 30. Figure 6 This is a top view showing the structure of the detection device 30.

[0114] Here, in the detection device 30, "detection end" is not limited to a detection device that directly detects the end (i.e., edge) of the medium P itself. For example, it also includes a detection device that detects markings (e.g., cutting marks) on the end of the medium P. The markings are placed at a predetermined distance from the end of the medium P, and the distance from the end of the medium P is known.

[0115] like Figure 4 and Figure 5 As shown, the detection device 30 includes a detection device body 40, a first unit 31, a second unit 32, an opening and closing part 70, and a conveying part 80 (see reference). Figure 1 ), front and rear end detection unit 90, side end detection unit 98, pressing component 110 (refer to Figure 12 and Figure 13 ), Pressing component 120 (refer to) Figure 6 The detection device 30 and the back-end sensor 99 are described below. The shape of the detection device 30 and the structure of each part of the detection device 30 will also be described. Furthermore, the configuration of the control device 160, the detection device 30 in the image forming apparatus 10, and the disassembly of the detection device 30 relative to the image forming apparatus main body 11 will be explained.

[0116] (Shape of the detection device 30)

[0117] like Figure 4 As shown, the length of the detection device 30 in the left-right direction (corresponding to the length in the conveying direction) and the length in the front-back direction (corresponding to the length in the width direction) are longer than its length in the vertical direction. That is, the detection device 30 is formed as a flat shape that is thinner in the vertical direction and expands in the front-back and left-right directions (specifically, the horizontal direction). Furthermore, since the detection device 30 conveys a medium P with a size of at least A3 Nobi, it has a size of at least A3 Nobi when viewed from above. Additionally, the shape of the detection device 30 is not limited to a flat shape and can be various shapes.

[0118] (Detection device body 40)

[0119] like Figure 5 As shown, similar to the overall shape of the detection device 30, the detection device body 40 is formed into a flat shape that is thinner in the vertical direction and expands in the front-back and left-right directions. Specifically, the detection device body 40 has a plate 41, a front plate 42, a rear plate 43, and a guide plate 44. In addition, the detection device body 40 is formed of, for example, sheet metal or other metal materials, resin materials, and other materials.

[0120] The plate body 41 is formed into a plate shape that extends in the front-back and left-right directions and has its thickness direction in the vertical direction. The upper surface of the plate body 41 is designated as the conveyor path surface 41A. An opening 41B is formed on the plate body 41, and a plurality of roller portions 842, 852, and 862 (described later) are arranged in the opening 41B. In this embodiment, as an example, 12 openings 41B are formed. A plurality of reflectors 97 (described later) are arranged on the upper surface of the plate body 41. In this embodiment, as an example, 8 reflectors 97 are arranged.

[0121] The front plate 42 is a plate extending downward from the front end of the plate body 41 and is integrally formed with the plate body 41. The front plate 42 is formed as a plate with the front-to-back direction as the thickness direction. The front plate 42 supports the drive rollers 84, 85, and 86 (described later) so that they can rotate (see reference). Figure 11 ).

[0122] A support portion 42A is provided on the front plate 42 to support the opening / closing portion 70. As an example, the support portion 42A is formed by cutting and erecting a portion of the plate 41.

[0123] The rear plate 43 is a plate extending upward from the rear end of the plate body 41 and is integrally formed with the plate body 41. The rear plate 43 is formed as a plate with the front-to-back direction as its thickness direction. As described later, the rear plate 43 functions as a positioning part for positioning the first unit 31 and the second unit 32. Multiple insertion holes 45E for inserting the protrusions 51E (described later) and insertion holes 46E for inserting the protrusions 61E (described later) are formed on the rear plate 43. In this embodiment, as an example, two insertion holes 45E are formed, and in this embodiment, as an example, three insertion holes 46E are formed. The insertion holes 45E and 46E are elongated holes that are longer in the left-to-right direction.

[0124] The guide plate 44 is connected to the right end of the plate body 41. It extends diagonally upward and to the right from the right end of the plate body 41. The guide plate 44 has the function of guiding the medium P towards the side of the plate body 41 (i.e., the left side). An opening 44B is formed at the lower end of the guide plate 44 for the medium P conveyed from the plate body 41 to the right side (i.e., the second conveying direction described later) to pass through. In addition, the curvature of the guide plate 44 is set to be small. Specifically, the curvature of the guide plate 44 is, for example, set to be smaller than the curvature of the conveying path 25. Therefore, the medium P conveyed in the guide plate 44 is less likely to bend. As a result, scratches caused by friction with the guide plate 44 are less likely to occur on the medium P and the image formed on the medium P.

[0125] (Unit 1, 31)

[0126] like Figure 4 and Figure 5 As shown, the first unit 31 is disposed on the upper side of the detection device body 40. Specifically, the first unit 31 is disposed on the upper side of the left side portion of the detection device body 40. Furthermore, the first unit 31 constitutes the left side portion of the upper part of the detection device 30.

[0127] The first unit 31 includes a unit body 50 and a substrate support 59. Furthermore, the first unit 31 is equipped with driven rollers 87 and 88 of the conveying unit 80 (described later), sensors 91(A), 92(A), 93(A), and (B) of the front and rear end detection units 90 and the side end detection unit 98 (described later), and sensor substrates 95(A), 95(B), 95(C), and 95(D). Additionally, the first unit 31 is formed from, for example, sheet metal or other metal materials, resin materials, and other materials.

[0128] like Figure 5 As shown, the unit body 50 has a plate 51, a front plate 52, a rear plate 53, a left plate 54, and a right plate 55. The plate 51 is formed as a plate that extends in the front-back and left-right directions and has the vertical direction as its thickness direction. The lower surface of this plate 51 is designated as the conveyor path surface 51A (see reference). Figure 5 , Figure 7 and Figure 13 An opening 51B for arranging driven rollers 87 and 88 and an opening 51C for arranging sensors 91(A), 92(A), 93(A)(B) are formed on the plate body 51 (see reference). Figure 6 Plate 51 is positioned opposite plate 41 on the upper side of plate 41 of the main body 40 of the detection device, with a gap between them (see reference). Figure 7 and Figure 13 ).

[0129] The front plate 52 is a plate that extends upward from the front end of the plate body 51. The rear plate 53 is a plate that extends upward from the rear end of the plate body 51. The front plate 52 and the rear plate 53 are formed as plates with the front-to-back direction as the thickness direction.

[0130] Left plate 54 is a plate extending upward from the left end of plate body 51. Right plate 55 is a plate extending upward from the right end of plate body 51. Left plate 54 and right plate 55 are formed as plates with the left-right direction as the thickness direction.

[0131] like Figure 5 , Figure 6 and Figure 7 As shown in (A) and (B), a protrusion 51E is provided at the rear end of the plate 51. This protrusion 51E is inserted into the insertion hole 45E of the rear plate 43 in the main body 40 of the detection device. The protrusion 51E is disposed on the same surface as the plate 51 and protrudes towards the rear side of the rear plate 53. As an example, the protrusion 51E is formed by cutting and erecting the rear plate 53. Furthermore, at the rear of the first unit 31, as shown in (A) and (B), a protrusion 51E is provided at the rear end of the plate 51. Figure 7 As shown in (A) and (B), the protrusion 51E is inserted into the insertion hole 45E and the rear plate 53 abuts against the rear plate 43 of the detection device body 40.

[0132] On the other hand, such as Figure 8 and Figure 9 As shown, a through hole 51D is formed at the front of the plate 51 for fastening components 38 such as bolts to pass through. Multiple through holes 51D are formed along the left-right direction. Moreover, at the front of the first unit 31, with a spacer 39 sandwiched between the plate 51 of the first unit 31 and the plate 41 of the detection device main body 40, the plate 51 and the plate 41 are fastened together by the fastening components 38.

[0133] By abutting the rear plate 53 against the rear plate 43 of the detection device body 40, the first unit 31 is positioned relative to the detection device body 40 in the front-rear direction. Furthermore, by inserting the protrusion 51E into the insertion hole 45E and fastening the plate 51 and plate 41 via the spacer 39 and the fastening member 38, the first unit 31 is positioned relative to the detection device body 40 in the vertical and horizontal directions.

[0134] Furthermore, the first unit 31 can be detached from the detection device body 40 by removing the fastening member 38. That is, the first unit 31 is configured to be detachable relative to the detection device body 40. In this embodiment, as described above, the first unit 31 is mounted to the detection device body 40 via the fastening member 38; however, the mounting member for mounting the first unit 31 to the detection device body 40 is not limited to the fastening member 38. For example, a clamp or any other component capable of mounting the first unit 31 to the detection device body 40 may be used.

[0135] like Figure 4 and Figure 5 As shown, the substrate support portion 59 is a portion that functions to support the sensor substrate 95, which will be described later. Specifically, as... Figure 5 As shown, the substrate support portion 59 has a mounting plate 59A and a connecting plate 59B. The mounting plate 59A is disposed on the upper side of the plate body 51. A plurality of sensor substrates 95 are mounted on the mounting plate 59A. The connecting plate 59B extends downward from the mounting plate 59A and is connected to the plate body 51.

[0136] (Unit 2, 32)

[0137] like Figure 4 and Figure 5 As shown, the second unit 32 is disposed on the upper side of the detection device body 40. Specifically, the second unit 32 is disposed on the upper side of the right side portion of the detection device body 40. Furthermore, the second unit 32 constitutes the right side portion of the upper part of the detection device 30. Therefore, the upper part of the detection device 30 can be divided into the first unit 31 and the second unit 32.

[0138] The second unit 32 includes a unit body 60 and a substrate support 69. Furthermore, the second unit 32 is equipped with the driven roller 89 of the conveying unit 80 (described later), the sensors 91(B), 92(B), 94(A)(B) of the front and rear end detection units 90 and the side end detection units 98 (described later), and sensor substrates 95(E), 95(F), 95(G), and 95(H). Additionally, the second unit 32 is formed from materials such as sheet metal, resin, and other materials.

[0139] like Figure 5 As shown, the unit body 60 has a plate 61, a front plate 62, a rear plate 63, a left plate 64, and a right plate 65. The plate 61 is formed as a plate that extends in the front-back and left-right directions and has the vertical direction as its thickness direction. The lower surface of this plate 61 is designated as the conveying path surface 61A (see reference). Figure 5 and Figure 7An opening 61B for arranging the driven roller 89 and an opening 61C for arranging the sensors 91(B), 92(B), and 94(A)(B) are formed on the plate 61 (see reference). Figure 6 Plate 61 is positioned opposite plate 41 on the upper side of plate 41 of the main body 40 of the detection device, with a gap between them (see reference). Figure 7 ).

[0140] The front plate 62 is a plate that extends upward from the front end of the plate body 61. The rear plate 63 is a plate that extends upward from the rear end of the plate body 61. The front plate 62 and the rear plate 63 are formed as plates with the front-to-back direction as the thickness direction.

[0141] Left plate 64 is a plate extending upward from the left end of plate body 61. Right plate 65 is a plate extending upward from the right end of plate body 61 along guide plate 44. Left plate 64 is formed as a plate with the left-right direction as the thickness direction.

[0142] like Figure 5 , Figure 6 and Figure 7 As shown in (A) and (B), a protrusion 61E is provided at the rear end of the plate 61, which is inserted into the insertion hole 46E of the rear plate 43 of the detection device body 40. The protrusion 61E is disposed on the same surface as the plate 61 and protrudes towards the rear of the rear plate 63. For example, the protrusion 61E is formed by cutting and erecting the rear plate 63. Furthermore, at the rear of the second unit 32, as... Figure 7 As shown in (A) and (B), the protrusion 61E is inserted into the insertion hole 46E and the rear plate 63 abuts against the rear plate 43 of the detection device body 40.

[0143] On the other hand, such as Figure 9 As shown, a through hole 61D is formed at the front of the plate 61 for fastening components 38 such as bolts to pass through. Multiple through holes 61D are formed along the left-right direction. Moreover, at the front of the second unit 32, with a spacer 39 sandwiched between the plate 61 of the second unit 32 and the plate 41 of the detection device main body 40, the plate 61 and the plate 41 are fastened together by the fastening components 38.

[0144] The second unit 32 is positioned relative to the detection device body 40 in the front-rear direction by abutting the rear plate 63 against the rear plate 43 of the detection device body 40. Furthermore, the second unit 32 is positioned relative to the detection device body 40 in the vertical and horizontal directions by inserting the protrusion 61E into the insertion hole 46E and fastening the plate 61 and plate 41 together with the fastening member 38 through the spacer 39.

[0145] Furthermore, the second unit 32 can be detached from the detection device body 40 by removing the fastening component 38. That is, the second unit 32 is configured to be detachable relative to the detection device body 40.

[0146] like Figure 4 and Figure 5 As shown, the substrate support portion 69 is a portion that functions to support the sensor substrate 95, which will be described later. Specifically, as... Figure 5 As shown, the substrate support 69 has a mounting plate 69A and a connecting plate 69B. The mounting plate 69A is disposed on the upper side of the plate body 61. A plurality of sensor substrates 95 are mounted on the mounting plate 69A. The connecting plate 69B extends downward from the mounting plate 69A and is connected to the plate body 61.

[0147] (Opening and closing part 70)

[0148] like Figure 4 and Figure 10 As shown, the opening / closing part 70 has a conveying path 80A in the conveying part 80 (see reference). Figure 1 The open opening 77 has the function of opening and closing. For example... Figure 4 As shown, the opening / closing part 70 is disposed on the upper side of the detection device body 40, between the first unit 31 and the second unit 32. The opening / closing part 70 is disposed between the sensors 91(A) and 92(A) provided in the first unit 31 and the sensors 91(B) and 92(B) provided in the second unit 32, and is disposed at a position where sensors 91 to 94 are not present. Furthermore, the opening / closing part 70 is formed of, for example, sheet metal or other metal materials, resin materials, or other materials.

[0149] like Figure 4 and Figure 5 As shown, the opening / closing part 70 includes a plate 71, a front plate 72, a rear plate 73, a left plate 74, and a holding part 76. The plate 71 is formed as a plate that extends in the front-back and left-right directions and has the vertical direction as its thickness direction. The lower surface of this plate 71 is designated as the conveying path surface 71A (see reference). Figure 10 ).

[0150] The front plate 72 extends upward from the front end of the plate body 71. The rear plate 73 extends upward from the rear end of the plate body 71. The front plate 72 and the rear plate 73 are formed as plates with the front-to-back direction as the thickness direction. The left plate 74 extends upward from the left end of the plate body 71. The left plate 74 is formed as a plate with the left-to-right direction as the thickness direction.

[0151] like Figure 4 and Figure 10 As shown, the opening and closing part 70 is capable of controlling the conveying path 80A in the conveying part 80 (see reference). Figure 1The opening 77 is supported on the main body 40 of the detection device in a manner that allows it to be opened and closed. That is, the opening / closing part 70 can move to a closed position to close the opening 77. Figure 4 The position shown) and the opening position that opens opening 77 ( Figure 10 (as shown in the figure) moves. Specifically, the right end of the front plate 72 and the right end of the rear plate 73 in the opening and closing part 70 are rotatably supported on the support part 42A and the rear plate 43 of the detection device body 40, respectively.

[0152] In the closed position, the opening / closing part 70 is positioned above the plate 41 of the main body 40 of the detection device, with a gap between them. A gripping part 76 is provided on the front surface of the front plate 72, protruding forward from the front plate 72. The operator grips the gripping part 76 to move the opening / closing part 70 between the closed and open positions.

[0153] As an example, the opening and closing section 70 is designed to eliminate [problems] in the conveyor path 80A (see reference). Figure 1 The opening and closing of the opening and closing section 70 is used to prevent blockage (so-called paper jam) of the medium P generated in the conveyor. However, the purpose of opening and closing the opening and closing section 70 is not limited to the above-described purpose; for example, it can also be used to open and close the conveyor path 80A (see reference 70). Figure 1 The conveyor path surfaces 71A and 41A are used for cleaning and can be opened and closed for various applications. Here, it is required that no significant damage is caused to the medium P and the image. Furthermore, whether or not significant damage occurs varies depending on the curvature of the guide plate 44 and the hardness of the medium P, and sometimes significant damage can occur due to foreign matter mixed into the conveyor path 80A. Therefore, it is beneficial that the conveyor path 80A is open and can be cleaned.

[0154] (Overview of the transport section 80)

[0155] exist Figure 1 The conveying unit 80 shown has a conveying path 80B for conveying medium P. On the conveying path 80B, the conveying of medium P is stopped and medium P is stretched in the stretching direction along the conveying path 80B.

[0156] The conveying path 80B is the path for conveying the heated medium P in the heating unit 19 within the detection device 30, and it is formed by the conveying path 80A. The conveying path 80A is a passage formed by the conveying path surfaces 41A, 51A, 61A, and 71A. For example... Figure 1 As shown, the transport path 80A constitutes part of the transport path 24 from the heating unit 19 to the image forming unit 14.

[0157] Furthermore, in the transport section 80, the transport of the medium P on which the frontal image is formed stops. After the medium P reaches a stopped state (i.e., a stationary state), the transport of the medium P resumes towards the image forming section 14 (specifically, the transfer position TA). Specifically, in the transport section 80, the medium P is transported to the left (hereinafter, the transport direction before the medium P stops is referred to as the "first transport direction"), then the transport of the medium P to the left stops. After the medium P stops, the transport of the medium P resumes to the right (hereinafter, the transport direction after the medium P stops is referred to as the "second transport direction"). That is, in the transport section 80, after the medium P stops, transport resumes in the second transport direction, which is different from the first transport direction. Furthermore, the first transport direction and the second transport direction are opposite directions. In other words, it can be said that the medium P is switched back in the transport section 80. Thus, in this embodiment, the left corresponds to the first transport direction, and the right corresponds to the second transport direction. Additionally, in the conveying unit 80, a medium P is conveyed. Furthermore, the conveying unit 80 stops the medium P at a predetermined stop position.

[0158] As described above, in the conveying unit 80, the medium P is conveyed in the conveying direction in the conveying path 80B, and the conveying of the medium P in the conveying direction stops. Furthermore, in the conveying unit 80, in the conveying path 80B, the medium P that has stopped conveying is stretched in a direction along the conveying path 80B (hereinafter referred to as the stretching direction). This stretching direction is the direction that includes the first conveying direction and the second conveying direction.

[0159] As described above, since the first conveying direction and the second conveying direction are opposite, the upstream side in the first conveying direction can be understood as the downstream side in the second conveying direction, and the downstream side in the first conveying direction can be understood as the upstream side in the second conveying direction. Therefore, in the detection device 30, each component disposed on the upstream side in the first conveying direction can be understood as a component disposed on the downstream side in the second conveying direction, and each component disposed on the downstream side in the first conveying direction can be understood as a component disposed on the upstream side in the second conveying direction.

[0160] Furthermore, in the description of the detection device 30, "conveyor direction" is defined as the direction representing the "first conveyor direction". Therefore, in the description of the detection device 30, the "first conveyor direction" is sometimes simply referred to as "conveyor direction".

[0161] (Specific structure of the conveyor section 80)

[0162] Specifically, such as Figure 16 and Figure 17As shown, the conveying unit 80 includes: an upstream conveying unit 80X, which conveys medium P in a first conveying direction along a conveying path 80B and stops the conveying; and a downstream conveying unit 80Y, which is disposed downstream of the upstream conveying unit 80X in the conveying direction, and conveys medium P in the first conveying direction along the conveying path 80B and stops the conveying. Additionally, in Figure 16 and Figure 17 In order to simplify the illustration, the conveyor surfaces 51A, 61A, and 71A are shown as a single unit.

[0163] The upstream conveying section 80X has a conveying member 83. The conveying member 83 is disposed in the upstream portion (specifically the right-side portion) of the detection device 30 in the conveying direction.

[0164] The downstream conveying section 80Y includes conveying components 81 and 82. Conveying components 81 and 82 are located downstream (specifically, to the left) of conveying component 83 in the conveying direction. Specifically, conveying component 82 is located upstream of conveying component 81 in the conveying direction and downstream of conveying component 83 in the conveying direction. Conveying components 81, 82, and 83 each have the function of conveying medium P in a first conveying direction (corresponding to the left) along conveying path 80B and stopping the conveying. Furthermore, conveying components 81, 82, and 83 have the function of stretching medium P in a stretching direction along conveying path 80B. Conveying components 81, 82, and 83 have the function of conveying medium P in a second conveying direction (corresponding to the right) along conveying path 80B. Conveying components 81 and 82 are an example of a downstream conveying section, and conveying component 83 is an example of an upstream conveying section. Furthermore, conveying component 81 is an example of a first conveying section, and conveying component 82 is an example of a second conveying section.

[0165] The conveying components 81, 82, and 83 each have: drive rollers 84, 85, and 86 as rotating components, which rotate and apply a conveying force to the medium P; and driven rollers 87, 88, and 89 as driven components, which are driven by the drive rollers 84, 85, and 86.

[0166] like Figure 11 As shown, drive rollers 84, 85, and 86 each have shaft portions 841, 851, and 861, roller portions 842, 852, and 862, and connecting portions 843, 853, and 863, respectively. Shaft portions 841, 851, and 861 are arranged in the front-rear direction. One axial end (specifically, the front end) of shaft portions 841, 851, and 861 is rotatably supported on the front plate 42 of the detection device body 40. The other axial end (specifically, the rear end) of shaft portions 841, 851, and 861 is rotatably supported on a shaft support portion (not shown) provided on the plate 41 of the detection device body 40.

[0167] Multiple roller portions 842, 852, and 862 are arranged at intervals along the axial direction of shaft portions 841, 851, and 861. Each roller portion 842, 852, and 862 protrudes upward from the opening 41B of the plate body 41. That is, the roller portions 842, 852, and 862 of the drive rollers 84, 85, and 86 (i.e., the portions in contact with the medium P) protrude upward toward the upper side of the conveying path surface 41A of the detection device body 40. In this embodiment, as shown by reference numerals (A), (B), (C), and (D) in the figures, four roller portions 842, 852, and 862 are provided.

[0168] Connecting portions 843, 853, and 863 are parts connected to connecting portions 743, 753, and 763 that rotate using driving force from drive sources 777 and 778, such as motors. Connecting portions 843, 853, and 863 are formed by couplings that are axially connected to each other. Connecting portions 743 and 753 receive driving force from drive source 777 via transmission components such as gears (not shown). Thus, conveying member 81, including drive roller 84 and driven roller 87, and conveying member 82, including drive roller 85 and driven roller 88, rotate using a common drive source 777. On the other hand, connecting portion 763 receives driving force from drive source 778 via transmission components such as gears (not shown). Thus, conveying member 83, including drive roller 86 and driven roller 89, rotates using drive source 778. The control device 160 functions as a control unit that controls the drive of the drive sources 777 and 778.

[0169] In this embodiment, as an example, connecting portions 743, 753, 763, drive sources 777, 778, and control device 160 are provided on the image forming apparatus body 11. That is, in this embodiment, connecting portions 743, 753, 763, drive sources 777, 778, and control device 160 are considered not structural elements of the detection device 30. Thus, by connecting portions 843, 853, 863 to connecting portions 743, 753, 763 disposed on the image forming apparatus body 11, the driving force of drive sources 777, 778 disposed on the image forming apparatus body 11 is transmitted to roller portions 842, 852, 862 via shaft portions 841, 851, 861, thereby driving rollers 84, 85, 86 to rotate.

[0170] like Figure 4 and Figure 5 As shown, multiple driven rollers 87, 88, and 89 are provided. Specifically, the number of driven rollers 87, 88, and 89 is the same as that of roller sections 842, 852, and 862. In this embodiment, as shown by reference numerals (A), (B), (C), and (D) in the figure, four driven rollers 87, 88, and 89 are provided.

[0171] The driven rollers 87, 88, and 89 are respectively arranged opposite to roller sections 842, 852, and 862. That is, multiple driven rollers 87, 88, and 89 are arranged along the front-to-back direction (four in this embodiment). In addition, the labels (A), (B), (C), and (D) for the driven rollers 87, 88, and 89 are marked in this order from the rollers arranged on the front side to the rollers arranged on the rear side.

[0172] The driven rollers 87(A) and 87(B), as well as the driven rollers 88(A) and 88(B), are respectively configured such that when viewed in a direction perpendicular to the image forming surface of the medium P, they are separated by a sensor 93(A) described later in the front-back direction.

[0173] Roller sections 842(A) and 842(B), as well as roller sections 852(A) and 852(B), are respectively configured such that when viewed in a direction perpendicular to the image forming surface of the medium P, the sensor 93(A), described later, is also separated from them in the front-to-back direction.

[0174] Specifically, driven rollers 87(A) and 87(B), as well as roller sections 842(A) and 842(B), are separated by the left portion of sensor 93(A) in the front-to-back direction. Driven rollers 88(A) and 88(B), as well as roller sections 852(A) and 852(B), are separated by the right portion of sensor 93(A) in the front-to-back direction.

[0175] The driven rollers 87(C) and 87(D), as well as the driven rollers 88(C) and 88(D), are respectively configured such that when viewed in a direction perpendicular to the image forming surface of the medium P, they are separated by a sensor 93(B), which will be described later, in the front-to-back direction.

[0176] Roller sections 842(C) and 842(D), as well as roller sections 852(C) and 852(D), are respectively configured such that when viewed in a direction perpendicular to the image forming surface of the medium P, a sensor 93(B), described later, is separated in the front-to-back direction.

[0177] Specifically, driven rollers 87(C) and 87(D), as well as roller sections 842(C) and 842(D), are separated by the left portion of sensor 93(B) (described later) in the front-to-back direction. Driven rollers 88(C) and 88(D), as well as roller sections 852(C) and 852(D), are separated by the right portion of sensor 93(B) (described later) in the front-to-back direction.

[0178] The driven rollers 89(A) and 89(B), as well as the roller section 862(A) and 862(B), are respectively configured such that when viewed in a direction perpendicular to the image forming surface of the medium P, the sensor 94(A), described later, is separated in the front-to-back direction.

[0179] The driven rollers 89(C) and 89(D), as well as the roller section 862(C) and 862(D), are respectively configured such that when viewed in a direction perpendicular to the image forming surface of the medium P, the sensor 94(B), described later, is separated in the front-to-back direction.

[0180] As described above, in this embodiment, the driven rollers 87, 88, 89 and roller sections 842, 852, 862 are configured such that when viewed in a direction perpendicular to the image forming surface of the medium P, the sensors 93 and 94 are appropriately spaced apart in the front-to-back direction (i.e., the width direction of the medium P).

[0181] like Figure 5 As shown, driven rollers 87 and 88 are respectively arranged in unit 31. Figure 13 As shown, the driven rollers 87 and 88 are supported by the plate 51 and are rotatable, with their outer peripheral surfaces (i.e., the contact surfaces with the medium P) protruding downward from the opening 51B of the plate 51 of the first unit 31. That is, the outer peripheral surfaces of each driven roller 87 and 88 protrude downward from the conveying path surface 51A of the first unit 31 and contact the roller portions 842 and 852, respectively.

[0182] Driven roller 89 is disposed in the second unit 32. Specifically, similar to driven rollers 87 and 88, driven roller 89 is supported by plate 61 in such a way that its outer peripheral surface (i.e., the contact surface with the medium P) protrudes downward from the opening 61B of plate 61 in the second unit 32, allowing it to rotate. That is, the outer peripheral surface of driven roller 89 protrudes downward from the conveying path surface 61A of plate 61 and contacts roller portion 862.

[0183] Furthermore, in the conveying section 80, each drive roller 84, 85, 86 and each driven roller 87, 88, 89 hold the medium P. By rotating the drive rollers 84, 85, 86, a conveying force is applied to the medium P, and the medium P is conveyed in the conveying path 80B.

[0184] Furthermore, in the conveying unit 80, conveying in the first conveying direction and conveying in the second conveying direction are performed by changing the rotation direction of the conveying components 81, 82, and 83 in the conveying path 80B. Also, in the conveying unit 80, during the period between conveying the medium P in the first conveying direction and conveying it in the second conveying direction, the conveying of the medium P is stopped, and the medium P is stretched in the stretching direction along the conveying path 80B (hereinafter, sometimes referred to as the stretched state). Here, the stretched state of the medium P means that, in addition to the state where both sides of the stopped medium P are not in contact with the conveying path, it also includes the state where at least one of the two sides of the stopped medium P is not in contact with the conveying path. Furthermore, the operation of the conveying unit 80 is controlled by the control device 160. The specific conveying operations in the conveying unit 80 will be described later.

[0185] Furthermore, the conveying unit 80 has conveying path surfaces 41A, 51A, 61A, and 71A (see reference) that face one side and the other side of the medium P in the stretched state, respectively. Figure 1 As described above, the conveyor surface 41A is formed by the upper surface of the plate 41 of the detection device body 40 (see reference). Figure 5 and Figure 13 ( ), which is opposite to the lower surface of the medium P in the tensile state, and guides the lower surface of the medium P.

[0186] Furthermore, the transport path surface 41A is designed to be a flat surface covering the entire surface of the medium P. Specifically, the transport path surface 41A is designed to be a flat surface covering the entire surface of the medium P with the largest size used in the image forming apparatus 10. Further, the transport path surface 41A is formed to be larger than the medium P with the largest size in both the transport direction and the width direction. Additionally, the transport path surface 41A may also have locally uneven surfaces. For example, the transport path surface 41A may have locally convex portions by protrusions of components such as reflectors 97 and rollers 842, 852, 862. Furthermore, the transport path surface 41A may also have locally concave portions by forming holes, grooves, and recesses such as openings 416B. Furthermore, the transport path surface 41A may also have a structure in which at least one of concave and convex portions is locally formed by forming ribs or by extruding sheet metal, thereby reducing the contact area with the medium P. Thus, the aforementioned "flat surface" includes flat surfaces with locally uneven surfaces.

[0187] As described above, the conveyor surface 51A is formed by the lower surface of the plate 51 of the first unit 31 (see reference). Figure 7 and Figure 13 This is opposite to the upper surface of the medium P in its stretched state, guiding the upper surface of the medium P. As described above, the conveying path surface 61A is formed by the lower surface of the plate 61 of the second unit 32 (see reference). Figure 7 This is opposite to the upper surface of the medium P in its stretched state, guiding the upper surface of the medium P. As described above, the conveying path surface 71A is formed by the lower surface of the plate 71 of the opening / closing part 70 (see reference). Figure 10 ), which is opposite to the upper surface of the medium P in the tensile state, and guides the upper surface of the medium P.

[0188] The passage surface on the upper side of the medium P in a stretched state, formed by the transport path surfaces 51A, 61A, and 71A, is set to be a flat surface covering the entire surface of the medium P. Specifically, this passage surface is set to be a flat surface covering the entire surface of the largest-sized medium P used in the image forming apparatus 10.

[0189] As described above, the conveying components 81 and 82 function as conveying medium P, but can also be understood as support portions that support the medium P conveyed by the conveying component 83. Specifically, the drive rollers 84 and 85 support the lower surface of the medium P using roller portions 842 and 852 that protrude above the conveying path surface 41A of the detection device body 40. The driven rollers 87 and 88 use their outer peripheral surfaces that protrude below the conveying path surface 51A of the first unit 31 to bring the medium P against the drive rollers 84 and 85.

[0190] Thus, in the conveying section 80, the drive rollers 84 and 85 support the lower surface of the medium P above the conveying path surface 41A of the detection device body 40 (i.e., away from the conveying path surface 41A).

[0191] The conveying members 81 and 82 are disposed at multiple positions corresponding to media P with different lengths in the conveying direction. Specifically, the conveying member 81 is disposed at a position that can support the downstream end of the media P with the largest size (specifically, the longest length in the conveying direction) used in the image forming apparatus 10 in the conveying direction. The conveying member 82 is disposed at a position that can support the lower end of the media P with the smallest size (specifically, the shortest length in the conveying direction) used in the image forming apparatus 10 in the conveying direction.

[0192] Furthermore, in the conveying section 80, the distance between the conveying component 82 of the downstream conveying section 80Y and the upstream conveying section 80X (specifically, the conveying component 83) is greater than the distance between the conveying component 81 and the conveying component 82 in the downstream conveying section 80Y.

[0193] (Back-end sensor 99)

[0194] The rear-end sensor 99 is a detection unit that detects the rear end of the medium P. The rear-end sensor 99 is disposed on the upstream side of the conveying member 83 in the conveying direction. That is, the rear-end sensor 99 detects the rear end of the medium P on the upstream side of the conveying member 83 in the conveying direction.

[0195] Specifically, the rear-end sensor 99 is configured as a non-contact sensor that detects the rear end of the medium P in a non-contact manner. More specifically, the rear-end sensor 99 is configured as a light sensor that uses light irradiated toward the medium P. More specifically, the rear-end sensor 99 is configured as a reflective light sensor that detects the rear end of the medium P by detecting the reflected light of the light irradiated toward the medium P. Alternatively, a transmissive light sensor can also be used as the rear-end sensor 99.

[0196] In this embodiment, as will be described later, each component of the conveying unit 80 operates based on the timing of the rear end of the medium P detected by the rear end sensor 99.

[0197] (Control device 160)

[0198] Here, the structure of the control device 160 will be described. The control device 160 has a control function that controls the operation of the image forming apparatus 10, which includes the detection device 30. In this embodiment, the control device 160 controls the operation of the transport section 80 of the detection device 30. Specifically, as... Figure 18 As shown, the control device 160 has a processor 161, a memory 162, a storage device 163, and a timer 164.

[0199] The term "processor" refers to a processor in a broad sense. As processor161, it includes general-purpose processors (e.g., CPU (Central Processing Unit)) and dedicated processors (e.g., Graphics Processing Unit (GPU), Application Specific Integrated Circuit (ASIC), Field Programmable Gate Array (FPGA), Programmable Logic Device, etc.).

[0200] Memory 163 stores control program 163A (see reference). Figure 19 The memory 163 contains various programs and data. Specifically, the memory 163 is implemented through recording devices such as HDD (Hard Disk Drive), SSD (Solid State Drive), and flash memory.

[0201] Memory 162 is a working area used by processor 161 to execute various programs, and temporarily records various programs or data during processing. Processor 161 reads various programs containing control program 163A from memory 163 into memory 162, and uses memory 162 as a working area to execute programs. Timer 164 is a measuring unit used to measure the first elapsed time, second elapsed time, third elapsed time, etc., as described later.

[0202] In the control device 160, the processor 161 implements various functions by executing the control program 163A. The functional structure implemented through the cooperation of the processor 161 (a hardware resource) and the control program 163A (a software resource) will be described below. Figure 19 This is a block diagram showing the functional structure of processor 161.

[0203] like Figure 19 As shown, in the control device 160, the processor 161 functions as an acquisition unit 161A and a control unit 161C by executing the control program 163A. The acquisition unit 161A acquires detection information obtained by the rear end of the detection medium P by the rear end sensor 99.

[0204] The control unit 161C controls the conveying unit 80 (specifically the drive source 777, 778) to perform the conveying operations shown below.

[0205] In the conveying section 80, such as Figure 20 As shown, drive rollers 84, 85, and 86 are driven to rotate in the forward direction ( Figure 16 The driven rollers 87, 88, and 89 rotate in the forward direction (counterclockwise) and in the forward direction (counterclockwise). Figure 16 The medium P rotates clockwise (in the direction of rotation). As a result, the medium P is conveyed in the first conveying direction (equivalent to the left).

[0206] Next, after the first elapsed time since the rear end of the medium P was detected by the rear sensor 99, the drive roller 86 and the driven roller 89 stop rotating (specifically, the rotation begins to stop).

[0207] Next, after a second elapsed time since the drive rollers 86 and 89 stopped rotating (specifically, since the rotation began to stop), the drive rollers 84 and 85 and the driven rollers 87 and 88 stop rotating (specifically, the rotation begins to stop). Thus, the medium P becomes a stopped state. In this way, the drive rollers 86 and 89, and the drive rollers 84 and 85 and the driven rollers 87 and 88, stop rotating with a time difference, thereby stretching the medium P along the stretching direction. That is, the medium P becomes a state where it is stopped from being conveyed on the conveying path 80B and is stretched in the stretching direction.

[0208] Furthermore, after a third elapsed time since the drive rollers 84 and 85 stopped rotating (specifically, since the rotation was first stopped), the drive rollers 84, 85, and 86 reverse direction. Figure 16 The clockwise direction of the driven rollers 87, 88, and 89 is reversed, and the driven rollers 87, 88, and 89 are reversed in the reverse direction. Figure 16 The direction of transport is reversed (counterclockwise). As a result, medium P is transported in the second transport direction (equivalent to the right).

[0209] Thus, in the conveying section 80, the conveying components 81, 82, and 83 (drive rollers 84, 85, and 86 and driven rollers 87, 88, and 89) convey the medium P in the first conveying direction, causing the conveying to stop. Furthermore, after the conveying component 83 stops conveying the medium P, the conveying components 81 and 82 also stop conveying the medium P, thereby stretching the medium P in the stretching direction. Moreover, the ends of the stretched medium P (specifically, the front and rear ends and a pair of side ends) are detected by the front and rear end detection units 90 and the side end detection units 98, as described later.

[0210] Furthermore, since the conveying components 81 and 82 are driven by a common drive source 777, the conveying component 81 rotates (forward and reverse) and stops together with the conveying component 82.

[0211] As described above, in this embodiment, the rotation of the conveying member 83 is stopped based on the detection timing of the rear end of the medium P detected by the rear end sensor 99. The conveying member 83 stops conveying the medium P in such a way that the amount of protrusion of the rear end of the medium P from the conveying member 83 towards the upstream side in the conveying direction is approximately the same as the length of the medium P in the conveying direction. Furthermore, the conveying members 81, 82, and 83 resume conveying the medium P from the end side of the medium P with approximately the same amount of protrusion (i.e., the upstream end side in the conveying direction (specifically the right end side)).

[0212] exist Figure 16 The diagram shows the stopping position of the medium P with the smallest size in the conveying path 80B. Figure 17 The diagram shows the stopping position where the medium P with the largest size stops on the transport path 80B.

[0213] At this stop position, the upstream portion of the smallest-sized medium P in the conveying direction is clamped by the drive roller 86 and the driven roller 89, and the downstream portion in the conveying direction is clamped by the drive roller 85 and the driven roller 88. Therefore, the conveying component 82 (drive roller 85 and driven roller 88) together with the conveying component 83 (drive roller 86 and driven roller 89) stretches the smallest-sized medium P.

[0214] For the largest size medium P, at this stop position, the upstream portion in the conveying direction is clamped by the drive roller 86 and the driven roller 89, and the downstream portion in the conveying direction is clamped by the drive roller 84 and the driven roller 87. Therefore, the conveying component 81 (drive roller 84 and driven roller 87) together with the conveying component 83 (drive roller 86 and driven roller 89) stretches the largest size medium P.

[0215] Furthermore, the largest size medium P is an example of "a medium whose length in the conveying direction is greater than or equal to a predetermined length", or at least the medium P with the largest length in the conveying direction. The smallest size medium P is an example of "a medium whose length in the conveying direction is less than a predetermined length", or at least the medium P with the smallest length in the conveying direction.

[0216] Furthermore, the control device 160 is disposed in the image forming apparatus 10, but is not limited thereto. For example, the control device 160 may also be disposed in other devices disposed outside the detection device 30 and the image forming apparatus 10, and the placement of the control device 160 is not limited.

[0217] (Front-end and back-end testing department 90)

[0218] The front and rear end detection unit 90 has the function of detecting the front and rear ends of the medium P when it is stopped from being conveyed and is stretched in the stretching direction. The front and rear end detection unit 90 is an example of a detection unit.

[0219] like Figure 5 and Figure 6 As shown, the front and rear detection units 90 include sensors 93 and 94, a sensor substrate 95, and wiring 96 (see reference). Figure 6 ) and reflector 97 (refer to Figure 5 ).

[0220] like Figure 5 and Figure 6 As shown, multiple sensors 93 and 94 are provided. Specifically, as indicated by labels (A) and (B) in the figure, a pair (i.e., two) of sensors 93 and 94 are provided.

[0221] Sensor 93 is a detection unit that detects the front end of medium P. Sensor 94 is a detection unit that detects the rear end of medium P. Sensors 93 and 94 are configured as non-contact sensors that detect the end of medium P in a non-contact manner. More specifically, sensors 93 and 94 are configured as photosensitive sensors that use light illuminating medium P. More specifically, sensors 93 and 94 have multiple detection elements (specifically, light-emitting elements and light-receiving elements) arranged along the transport direction, and are composed of line sensors that are set to be relatively long in the transport direction. More specifically, as an example, sensors 93 and 94 are composed of contact image sensors (CIS). Alternatively, line sensors other than contact image sensors can also be used as sensors 93 and 94.

[0222] In sensors 93 and 94, a detection area is formed by multiple detection elements arranged along the conveying direction. The length of this detection area in the conveying direction is the same as or smaller than the length of the sensors 93 and 94 in the conveying direction. In sensors 93 and 94, the position of the end of the detection medium P at the boundary between detection and non-detection of each detection element in the detection area is sent, for example, to the control device 160, representing position information in terms of its coordinates (specifically, the number of pixels from the downstream end of the detection area in the conveying direction).

[0223] Sensor 93 is disposed on the downstream side (specifically, the left side) of the detection device 30 in the conveying direction. Sensor 93 is positioned opposite the downstream end of the medium P in the conveying direction under tension. Specifically, sensor 93 is configured such that, when viewed in a direction perpendicular to the image forming surface of medium P, its long side intersects the downstream end of the medium P in the conveying direction under tension, and detects this downstream end. More specifically, sensor 93 is configured such that, when viewed in a direction perpendicular to the image forming surface of medium P, its detection area intersects the downstream end of the medium P in the conveying direction under tension, which is stopped at a predetermined position, in its long side direction. In other words, sensor 93 is configured such that the downstream end of the medium P in the conveying direction under tension, stopped at a predetermined position, is located between one end and the other end of the long side direction of the detection area of ​​sensor 93.

[0224] Sensor 94 is disposed on the upstream side (specifically, the right side) of the detection device 30 in the conveying direction. Sensor 94 is positioned opposite the upstream end of the medium P in the conveying direction under tension. Specifically, sensor 94 is configured such that, when viewed in a direction perpendicular to the image forming surface of medium P, its long side intersects with the upstream end of the medium P in the conveying direction under tension, and detects this upstream end. More specifically, sensor 94 is configured such that, when viewed in a direction perpendicular to the image forming surface of medium P, its detection area intersects with the upstream end of the medium P in the conveying direction under tension, which is stopped at a predetermined position, in its long side direction. In other words, sensor 94 is configured such that the upstream end of the medium P in the conveying direction under tension, stopped at a predetermined position, is located between one end and the other end of the long side direction of the detection area of ​​sensor 94.

[0225] Specifically, sensors 93(A) and 94(A) are arranged in a left-right direction on the front side of the detection device 30. On the other hand, sensors 93(B) and 94(B) are arranged in a left-right direction on the rear side of the detection device 30.

[0226] In the front-end and rear-end detection units 90, multiple sensor substrates 95, wiring 96, and reflectors 97 are provided. Specifically, the number of sensor substrates 95, wiring 96, and reflectors 97 is the same as that of sensors 93 and 94. In the front-end and rear-end detection units 90, four wirings 96 and four reflectors 97 are provided. Furthermore, as shown by reference numerals (B), (C), (F), and (G) in the figure, four sensor substrates 95 are provided.

[0227] The four sensor substrates 95 are driving substrates that drive the four sensors 93 and 94 respectively. Each of the four sensor substrates 95 is configured close to the four sensors 93 and 94. Specifically, sensors 93 and 94 are driven by the sensor substrate 95 that is closest to them among the four sensor substrates 95. That is, sensors 93(A), 93(B), 94(A), and 94(B) are driven by sensor substrates 95(B), 95(C), 95(F), and 95(G), respectively.

[0228] The four wirings 96 are connecting lines that electrically connect the four sensor substrates 95 to the four sensors 93 and 94 respectively. The four wirings 96 are arranged separately from each other without being bundled. In other words, each of the four wirings 96 is not arranged along the other wirings 96. Furthermore, the four wirings 96 are arranged so as not to intersect each other. Four reflectors 97 are respectively disposed opposite to the four sensors 93 and 94 on the transport path surface 41A of the plate 41 of the detection device body 40. Considering the case where white paper is used as the medium P, as an example, the reflectors 97 are colored black, which has a relatively large difference in reflectivity compared to white.

[0229] (Side end detection unit 98)

[0230] The side-end detection unit 98 has the function of detecting the side end of the medium P while the front and rear end detection units 90 detect the front and rear ends. In other words, the side-end detection unit 98 detects the side end of the medium P in a stretched state. Figure 5 and Figure 6 As shown, the side detection unit 98 includes sensors 91 and 92, a sensor substrate 95, and wiring 96 (see reference). Figure 6 ) and reflector 97 (refer to Figure 5 ).

[0231] like Figure 5 and Figure 6 As shown, multiple sensors 91 and 92 are provided. Specifically, as indicated by labels (A) and (B) in the figure, a pair (i.e., two) of sensors 91 and 92 are provided.

[0232] Sensor 91 is a detection unit that detects one end of the medium P (specifically, the end on the front side of the device). Sensor 92 is a detection unit that detects the other end of the medium P (specifically, the end on the rear side of the device). Sensors 91 and 92 are configured as non-contact sensors that detect the end of the medium P in a non-contact manner. More specifically, sensors 91 and 92 are configured as light sensors that use light illuminating the medium P. More specifically, sensors 91 and 92 have multiple detection elements (specifically, light-emitting elements and light-receiving elements) arranged along the width direction, and are composed of line sensors that are set to be relatively long in the width direction. More specifically, as an example, sensors 91 and 92 are composed of contact image sensors (CIS). Alternatively, line sensors other than contact image sensors can also be used as sensors 91 and 92.

[0233] In sensors 91 and 92, a detection area is formed by multiple detection elements arranged along the width direction. The length of this detection area in the width direction is the same as or smaller than the width direction length of sensors 91 and 92. In sensors 91 and 92, the position of the end of the detection medium P at the boundary between detection and non-detection of each detection element in the detection area is sent, for example, to the control device 160, representing position information in terms of its coordinates (specifically, the number of pixels from the rear end of the detection area).

[0234] Sensor 91 is disposed on the front side of the detection device 30. Sensor 91 is positioned opposite one end (i.e., one end in the width direction) of the medium P in its stretched state. Specifically, sensor 91 is configured to intersect one end of the medium P in its stretched state along its long side when viewed in a direction perpendicular to the image forming surface of the medium P, and to detect this one end. More specifically, sensor 91 is configured such that, when viewed in a direction perpendicular to the image forming surface of the medium P, its detection area intersects with one end of the medium P in its stretched state, which is stopped at a predetermined position, along its long side. In other words, sensor 91 is configured such that one end of the medium P in its stretched state, stopped at a predetermined position, is located between one end and the other end of the long side of the detection area of ​​sensor 91.

[0235] Sensor 92 is disposed in the rear portion of the detection device 30. This sensor 92 is positioned opposite the other end (i.e., the other end in the width direction) of the medium P in its stretched state. Specifically, sensor 92 is configured such that, when viewed in a direction perpendicular to the image forming surface of medium P, its long side direction intersects with the other end of the medium P in its stretched state, and detects this other end. More specifically, sensor 92 is configured such that, when viewed in a direction perpendicular to the image forming surface of medium P, its detection area intersects with the other end of the medium P in its stretched state, which is stopped at a predetermined position, in its long side direction. In other words, sensor 92 is configured such that the other end of the medium P in its stretched state, stopped at a predetermined position, is located between one end and the other end in the long side direction of the detection area of ​​sensor 92.

[0236] Specifically, the downstream portions of sensors 91(A) and 92(A) in the conveying direction of the detection device 30 (specifically, the first unit 31) are arranged in the front-back direction. On the other hand, the upstream portions of sensors 91(B) and 92(B) in the conveying direction of the detection device 30 (specifically, the second unit 32) are arranged in the front-back direction.

[0237] Furthermore, in this embodiment, during side-view observation, sensors 91 and 92 are located between sensors 93 and 94. That is, sensors 91 and 92 are positioned upstream of sensor 93 in the transport direction and downstream of sensor 94 in the transport direction. Additionally, side-view observation refers to the observation from one side of the width direction of the medium P towards the other.

[0238] In the side-end detection unit 98, multiple sensor substrates 95, wiring 96, and reflectors 97 are provided. Specifically, the number of sensor substrates 95, wiring 96, and reflectors 97 is the same as that of sensors 91 and 92. In the side-end detection unit 98, four wirings 96 and four reflectors 97 are provided. Furthermore, as shown by the reference numerals (A), (D), (E), and (H) in the figure, four sensor substrates 95 are provided.

[0239] The four sensor substrates 95 are driving substrates that drive the four sensors 91 and 92 respectively. The four sensor substrates 95 are configured close to the four sensors 91 and 92. Specifically, sensors 91 and 92 are driven by the sensor substrate 95 that is closest to them among the four sensor substrates 95. That is, sensors 91(A), 92(A), 91(B), and 92(B) are driven by sensor substrates 95(A), 95(D), 95(E), and 95(H), respectively.

[0240] The four wirings 96 are connecting lines that electrically connect the four sensor substrates 95 to the four sensors 91 and 92, respectively. The four wirings 96 are arranged separately from each other without being bundled. In other words, each of the four wirings 96 is not arranged along the other wirings 96. Furthermore, the four wirings 96 are arranged so as not to intersect each other. Four reflectors 97 are respectively disposed opposite to the four sensors 91 and 92 on the transport path surface 41A of the plate 41 of the detection device body 40. Considering the case where white paper is used as the medium P, as an example, the reflectors 97 are colored black, which has a relatively large difference in reflectivity compared to white.

[0241] In this embodiment, sensor substrates 95(A), 95(B), 95(C), and 95(D) are mounted on the mounting plate 59A of the substrate support portion 59 in a rearward arrangement. Sensor substrates 95(E), 95(F), 95(G), and 95(H) are mounted on the mounting plate 69A of the substrate support portion 69 in a rearward arrangement.

[0242] Furthermore, in this embodiment, sensors 91(A), 92(A), 93(A)(B) and sensor substrates 95(A), 95(B), 95(C), and 95(D) are disposed in the first unit 31. Additionally, wiring 96 that electrically connects sensors 91(A), 92(A), and 93(A)(B) to sensor substrates 95(A), 95(B), 95(C), and 95(D) respectively is disposed in the first unit 31.

[0243] Furthermore, in this embodiment, sensors 91(B), 92(B), 94(A)(B) and sensor substrates 95(E), 95(F), 95(G), and 95(H) are disposed in the second unit 32. Additionally, wiring 96, which electrically connects sensors 91(B), 92(B), and 94(A)(B) to sensor substrates 95(E), 95(F), 95(G), and 95(H) respectively, is disposed in the second unit 32. Thus, since sensors 91 to 94 are disposed in the first unit 31 and the second unit 32, the end of the medium P is detected from the upper side of the medium P in its stretched state. Therefore, compared to the case where sensors 91 to 94 detect the end of the medium P from the lower side of the medium P in its stretched state, the adhesion of foreign matter such as paper dust to sensors 91 to 94 can be suppressed.

[0244] (Pressing component 110)

[0245] Figure 12 and Figure 13 The pressing member 110 shown is a component at the end of the medium P in the pressed and stretched state. Furthermore, pressing the end of the medium P means restricting its movement in the vertical direction.

[0246] like Figure 12 and Figure 13 As shown, multiple pressing components 110 are provided. Specifically, in this embodiment, as... Figure 12 As indicated by labels (A), (B), (C), and (D), four pressing components 110 are provided. Each pressing component 110 is composed of a sheet-like elastic component such as a resin film.

[0247] like Figure 13 As shown, pressing members 110(A) and 110(B) are positioned between conveying member 81 and conveying member 82 when viewed from the side. Furthermore, as... Figure 12 As shown, the pressing member 110(A) and the pressing member 110(B) are configured such that when viewed in a direction perpendicular to the image forming surface of the medium P, they are separated by the sensor 93(A) in the front-back direction.

[0248] like Figure 13As shown, pressing members 110(C) and 110(D) are positioned downstream of the conveying member 81 in the conveying direction when viewed from the side. Furthermore, as... Figure 12 As shown, the pressing member 110 (C) and the pressing member 110 (D) are configured such that when viewed in a direction perpendicular to the image forming surface of the medium P, they are separated by the sensor 93 (A) in the front-to-back direction.

[0249] The upstream ends (i.e., right ends) of the pressing components 110(A), 110(B), 110(C), and 110(D) in the conveying direction are mounted on the conveying path surface 41A of the detection device body 40. By means of their own elastic force, the downstream portion (i.e., the left portion) in the conveying direction is pressed against the conveying path surface 51A of the first unit 31. Thus, the pressing components 110(A), 110(B), 110(C), and 110(D) press the end (specifically the downstream end) of the medium P in a stretched state by pressing the medium P conveyed between themselves and the conveying path surface 51A against the conveying path surface 51A.

[0250] In addition, although Figure 12 and Figure 13 Not shown in the figure, but in this embodiment, the pressing member 110 is arranged in the same manner as the structure described above, such that when viewed in a direction perpendicular to the image forming surface of the medium P, it is separated from the sensor 93 (B) in the front-back direction.

[0251] As described above, in this embodiment, the pressing member 110 is configured such that it is appropriately spaced from the sensor 93 in the front-to-back direction when viewed from a direction perpendicular to the image forming surface of the medium P.

[0252] (Pressing component 120)

[0253] Figure 6 The pressing member 120 shown is an example of a support portion, which supports the medium P at the side end detected by the side end detection portion 98. Specifically, the pressing member 120 presses the side end of the medium P in a stretched state. In addition, pressing the side end of the medium P means restricting its movement in the vertical direction.

[0254] like Figure 6 As shown, multiple pressing components 120 are provided. Specifically, in this embodiment, as... Figure 6 As indicated by labels (A), (B), (C), and (D), four pressing components 120 are provided. Each pressing component 120 is composed of a sheet-like elastic component such as a resin film.

[0255] The pressing components 120(A), 120(B), 120(C), and 120(D) are disposed downstream of the conveying component 83 in the conveying direction and upstream of the conveying component 82 in the conveying direction.

[0256] The pressing member 120(A) is disposed upstream of the sensor 92(A) in the conveying direction. The front-to-back length of the pressing member 120(A) is set to be approximately the same as the front-to-back length of the sensor 92(A).

[0257] The pressing member 120(B) is disposed upstream of the sensor 92(B) in the conveying direction. The longitudinal length of the pressing member 120(B) is set to be approximately the same as the longitudinal length of the sensor 92(B). The pressing members 120(A) and 120(B) are disposed behind the sensors 93(B) and 94(B).

[0258] The pressing member 120(C) is positioned upstream of the sensor 91(A) along the conveying direction of the sensor 91(A). The longitudinal length of the pressing member 120(C) is set to be approximately the same as the longitudinal length of the sensor 91(A).

[0259] The pressing member 120(D) is disposed upstream of sensor 91(B) in the conveying direction. The front-to-back length of the pressing member 120(D) is set to be approximately the same as the front-to-back length of sensor 91(B). The pressing members 120(C) and 120(D) are disposed in front of sensors 93(A) and 94(A).

[0260] The upstream ends (i.e., right ends) of the pressing components 120(A), 120(B), 120(C), and 120(D) in the conveying direction are mounted on the conveying path surface 41A of the detection device body 40, and the downstream portions (i.e., left portions) in the conveying direction are pressed against the conveying path surface 51A of the first unit 31 by their own elastic force. Thus, the pressing components 120(A), 120(B), 120(C), and 120(D) press the side ends of the medium P in a stretched state against the conveying path surface 51A by pressing the medium P conveyed between themselves and the conveying path surface 51A. Thus, the side ends of the medium P are supported.

[0261] Furthermore, the sensor 91(A), 91(B), 92(A), 92(B) detects the end of the medium P supported by the pressing components 120(A), 120(B), 120(C), 120(D).

[0262] In addition, in this embodiment, the pressing components 120(A), 120(B), 120(C), and 120(D) have length in the front-back direction, but the pressing components 120(A), 120(B), 120(C), and 120(D) may also be composed of multiple components that are divided into multiple parts in the front-back direction.

[0263] (Control function of detection device 30 in control device 160)

[0264] Here, the control function of the control device 160 in controlling the operation of the detection device 30 will be explained. Figure 14 and Figure 15 The structural elements of the control device 160 that perform the control function of controlling the operation of the detection device 30 are shown. Specifically, as described above, the control device 160 includes a processor 161, a memory 162, and a storage device 163 (see reference). Figure 14 ).

[0265] In the control device 160, the processor 161 implements various functions by executing the control program 163A. The functional structure implemented through the cooperation of the processor 161 (a hardware resource) and the control program 163A (a software resource) will be described below. Figure 15 This is a block diagram showing the functional structure of processor 161.

[0266] like Figure 15 As shown, in the control device 160, the processor 161 functions as the acquisition unit 161A, the measurement unit 161B, and the control unit 161C by executing the control program 163A.

[0267] The acquisition unit 161A acquires detection information obtained by the front and rear end detection units 90 and the side end detection unit 98 from detecting the ends of the medium P. This detection information includes position information indicating the position of the ends of the medium P. Specifically, for the front and rear ends of the medium P, the position information indicates the position in the transport direction; for the side ends of the medium P, the position information indicates the position in the width direction.

[0268] Specifically, for example, the position of the end of the detection medium P at the boundary between the detection and non-detection of each detection element of the sensors 93 and 94 in the detection area is obtained by the acquisition unit 161A, which obtains position information represented by its coordinates (specifically, the number of pixels from the downstream end of the conveying direction of the detection area).

[0269] Furthermore, for example, the position of the end of the detection medium P at the boundary between detection and non-detection by the sensors 91 and 92 in the detection area is obtained by the acquisition unit 161A, which obtains position information represented by its coordinates (specifically, the number of pixels from the rear end of the detection area).

[0270] The measuring unit 161B measures the length in the conveying direction and the length in the width direction of the medium P based on the position information obtained by the acquiring unit 161A. Specifically, the measuring unit 161B measures the length in the conveying direction of the medium P as follows.

[0271] For example, such as Figure 21 and Figure 23 As shown, the measuring unit 161B calculates the distance LB from the rear end of the medium P to the upstream end (i.e., the right end) of the detection area of ​​the sensor 94 based on the position information.

[0272] Specifically, the distance LB is calculated using the following equation (1) based on the total number of pixels P1 (pixels / mm) of the detection elements of sensor 94 and the number of pixels P2 (pixels) from the upstream end of the conveying direction of the detection area of ​​sensor 94 to the rear end of medium P. Additionally, Figures 21-23 This is a schematic diagram, illustrating the various structural components (conveying components 82, 83, sensors 91-94).

[0273] Equation (1): LB = P2 ÷ P1

[0274] Furthermore, the measuring unit 161B, for example, uses this position information to determine the distance LC from the front end of the medium P to the upstream end (i.e., the right end) of the detection area of ​​the sensor 93.

[0275] Specifically, the distance LC is calculated using the following equation (2) based on the total number of pixels P3 (pixels / mm) of the detection element of sensor 93 and the number of pixels P4 (pixels) from the upstream end of the conveying direction of the detection area of ​​sensor 93 to the front end of medium P.

[0276] Equation (2): LC = P4 ÷ P3

[0277] Here, the distance LA from the upstream end (i.e., the right end) of sensor 94 to the upstream end (i.e., the right end) of sensor 93 is known. Then, the measuring unit 161B calculates the transport direction length L1 of medium P using the following formula (3).

[0278] Equation (3): L1 = LA + LC - LB

[0279] In addition, the measuring unit 161B measures the length in the width direction of the medium P, for example, as follows.

[0280] For example, such as Figure 23As shown, the measuring unit 161B calculates the distance WB from one side end of the medium P (i.e., the end on the rear side of the device) to the rear end of the detection area of ​​the sensor 92 (i.e., the end on the rear side of the device) based on the position information.

[0281] Specifically, the distance WB is calculated using the following equation (4) based on the total number of pixels P5 (pixels / mm) of the detection element of sensor 92 and the number of pixels P6 (pixels) from the rear end of the detection area of ​​sensor 92 to one side end of medium P.

[0282] Equation (4): WB = P6 ÷ P5

[0283] Furthermore, the measuring unit 161B, for example, uses this position information to determine the distance WC from the other end of the medium P (i.e., the end on the front side of the device) to the rear end of the detection area of ​​the sensor 91 (i.e., the end on the rear side of the device).

[0284] Specifically, the distance WB is calculated using the following equation (5) based on the total number of pixels P7 (pixels / mm) of the detection element of sensor 91 and the number of pixels P8 (pixels) from the rear end of the detection area of ​​sensor 91 to the other side end of medium P.

[0285] Equation (5): WC = P8 ÷ P7

[0286] Here, the distance WA from the rear end of sensor 92 to the rear end of sensor 91 is known. Then, the measuring unit 161B calculates the width direction length W1 of medium P using the following formula (6).

[0287] Equation (6): W1 = WA + WC - WB

[0288] Then, the measuring unit 161B measures the size of the medium P based on the measured length in the conveying direction and the length in the width direction of the medium P.

[0289] In this embodiment, the transport direction length L1 of one end portion and the other end portion of the medium P is determined based on the detection results of sensors 93(B) and 94(B) arranged in the left-right direction in the rear portion of the detection device 30 and sensors 93(A) and 94(A) arranged in the left-right direction in the front portion of the detection device 30.

[0290] Here, when paper is used as the medium P, the transport direction length L1 in the width direction of the medium P may sometimes differ between one end portion and the other end portion due to cutting errors. However, this cutting error can be measured by measuring the transport direction length L1 in the width direction of the medium P at one end portion and the other end portion. Furthermore, for example, any one of the average, minimum, and maximum values ​​of the transport direction length L1 in the width direction of the medium P at one end portion and the other end portion can be set as the transport direction length of the medium P.

[0291] Furthermore, in this embodiment, based on the detection results of sensors 91(A) and 92(A) arranged in the front-back direction in the left side portion of the detection device 30 and sensors 91(B) and 92(B) arranged in the front-back direction in the right side portion of the detection device 30, the width direction length W1 in the downstream and upstream portions of the medium P in the transport direction can be determined.

[0292] Here, when paper is used as the medium P, the width direction length W1 of the downstream and upstream portions of the medium P in the transport direction may sometimes differ due to cutting errors. However, this cutting error can be measured by measuring the width direction length W1 of the downstream and upstream portions of the medium P in the transport direction. Furthermore, for example, any one of the average, minimum, and maximum values ​​of the width direction length W1 of the downstream and upstream portions of the medium P in the transport direction can be set as the width direction length of the medium P.

[0293] Furthermore, in this embodiment, for example, the slant (i.e., tilt) of the medium P can be detected based on the offset of the detection position between sensors 91(A), 92(A), 93(A), 94(A) and sensors 91(B), 92(B), 93(B), 94(B). The tilt of the medium P can also be corrected to determine the length of the medium P in the transport direction and the length of the medium P in the width direction.

[0294] The control unit 161C adjusts the image of the medium P to be formed on the end of the medium P based on the size of the medium P measured by the measuring unit 161B. That is, after the detection device 30 detects the end of the medium P, the control unit 161C adjusts the image of the reverse image to be formed on the detected medium P based on the size of the medium P measured by the measuring unit 161B. For example, if the size of the medium P measured by the measuring unit 161B is smaller than the size specified as the size of the medium P to form the image, the control unit 161C controls the image forming unit 14 to reduce the size to form the reverse image.

[0295] Furthermore, the control device 160 is disposed on the image forming apparatus 10, but is not limited thereto. For example, the control device 160 may also be disposed on the detection device 30, or other devices disposed outside the image forming apparatus 10, and the placement location of the control device 160 is not limited.

[0296] (Configuration of detection device 30)

[0297] As described above, the detection device 30 is disposed inside the main body 11 of the image forming apparatus. Specifically, the detection device 30 is disposed on the upper side of the media receiving portion 12 in the vertical direction. As described above, since the detection device 30 is formed into a flat shape that extends in the front-back direction and the left-right direction (specifically the horizontal direction), space is saved in the vertical direction.

[0298] Furthermore, the detection device 30, including the transport unit 80, is disposed in the image forming apparatus 10 at a position where the transport of the medium P stops. More specifically, the detection device 30, including the transport unit 80, is disposed in the transport path of the image forming apparatus 10 in a transport path 24 that stops the transported medium P by reversing its direction. Specifically, the transport path 24 is a transport path that stops the medium P by reversing its direction.

[0299] In conveying path 24, the medium P is reversed by turning. Turning refers to the action of making the medium P travel back and forth within the same path. That is, turning is the action of changing the direction of the medium P.

[0300] As described above, the transport path 24 is a transport path that transports the medium P from the heating unit 19 to the image forming unit 14. Furthermore, the detection device 30 is disposed in the transport path 24 upstream of the transport direction at the supply position 25A where new medium P is supplied to the image forming unit 14.

[0301] Furthermore, in this embodiment, as described above, the media receiving section 12, the image forming section 14, and the heating section 19 are disposed in portion 18A of the housing 18. The detection device 30 is disposed in portion 18B of the housing 18. That is, the detection device 30, which includes the front and rear end detection sections 90, and the heating section 19 are disposed in different portions 18A and 18B of the housing 18.

[0302] Furthermore, in this embodiment, as described above, the detection device 30, including the front and rear end detection units 90, is located downstream of the heating unit 19 in the conveying direction. Therefore, the front and rear end detection units 90 detect the front and rear ends of the medium P in a stretched state after the medium P is heated and before the medium P is imaged again.

[0303] Furthermore, in this embodiment, the detection device 30, which includes front and rear end detection units 90, is disposed on the lower side of the heating unit 19.

[0304] (The function of this implementation method)

[0305] As described above, in the detection device 30, the front and rear end detection units 90 detect the front and rear ends of the medium P when the conveying has stopped and it is stretched in the stretching direction.

[0306] In the structure (Comparative Example 1) in which the front and rear ends of the medium P being transported are detected by a detection unit equipped with sensors on the transport path 80B, since the medium P is moving, the posture of the medium P is prone to change, and there is a situation where the front and rear ends of the medium P cannot be detected with high precision.

[0307] Furthermore, for example, in a structure that only performs a stopping operation on the conveyed medium P and detects the front and rear ends of the medium P (Comparative Example 2), such as Figure 22 As shown, when medium P flexes, the front and rear ends become close together, making it impossible to accurately detect the relative positions of the front and rear ends. Specifically, as... Figure 22 As shown, the distance LC will be used as the distance LD to calculate the distance.

[0308] In contrast, in this embodiment, as described above, since the front and rear end detection units 90 detect the front and rear ends of the medium P when the conveying is stopped and it is stretched in the stretching direction, compared to Comparative Examples 1 and 2, it is possible to detect the front and rear ends of the medium P when the deflection and wrinkles in the conveying direction of the medium P are reduced. In other words, according to this embodiment, compared to Comparative Examples 1 and 2, the detection of the front and rear ends when the front and rear ends of the medium P are close in the conveying direction of the medium P can be suppressed. Furthermore, according to this embodiment, compared to Comparative Examples 1 and 2, it is possible to detect the front and rear ends of the medium P when the posture of the medium P is closer to a plane. As a result, the detection accuracy of the front and rear ends of the medium P is improved. Furthermore, the measurement accuracy of the length of the medium P in the conveying direction is improved. In addition, in Figure 22 In the diagram, the medium P in the flexural state is represented by a solid line, and the medium P in the tensile state is represented by a double-dotted line. Furthermore, in... Figure 22 The diagram simplifies the view of the transport path surface above the medium P, which is composed of transport path surfaces 51A, 61A, and 71A. The medium P in a flexed state is in contact with the upper transport path surfaces 51A, 61A, and 71A and the lower transport path surface 41A.

[0309] In this embodiment, on the conveying path 80B, the conveying components 81, 82, and 83, which convey the medium P in the first conveying direction and stop the conveying, stretch the medium P in the stretching direction.

[0310] Therefore, there is no need to set up a separate stretching unit for stretching medium P, which reduces the number of components compared to the case where the conveying components 81, 82, and 83 only have the function of conveying medium P.

[0311] In this embodiment, after the conveying member 83 stops conveying the medium P, the conveying members 81 and 82 stop conveying the medium P, thereby the conveying members 81, 82 and 83 stretch the medium P in the stretching direction.

[0312] Therefore, the medium P can be stretched while the medium P is stopped, which reduces the total action time of stopping and stretching compared to the case where at least one of the conveying components 81, 82, and 83 stretches the medium after the conveying components 81, 82, and 83 have stopped conveying the medium P at the same time.

[0313] In this embodiment, the downstream conveying section 80Y has a conveying member 81 and a conveying member 82 disposed on the upstream side of the conveying direction of the conveying member 81.

[0314] Therefore, compared to the case where the downstream conveying section 80Y has only a single conveying component, the position of the stretching medium P has a higher degree of freedom.

[0315] In this embodiment, conveying member 82 and conveying member 83 stretch the medium P with the smallest dimension, and conveying member 81 and conveying member 83 stretch the medium P with the largest dimension.

[0316] Therefore, compared to the case where the largest size medium P is also stretched by the conveying member 82 and the conveying member 83, the deflection at the front end of the largest size medium P can be suppressed.

[0317] In this embodiment, conveying component 81 and conveying component 82 rotate using a common drive source 777. Therefore, compared to the case where conveying component 81 and conveying component 82 are rollers that rotate using different drive sources, the number of components can be reduced.

[0318] In this embodiment, by sharing the drive source for the shorter conveying section group (specifically, conveying member 81 and conveying member 82) and using separate drive sources for the longer conveying section group (specifically, conveying member 82 and conveying member 83), the stretching effect can be maintained while reducing the number of parts.

[0319] In this embodiment, the conveying member 83 stops conveying the medium P in such a way that the amount of protrusion of the rear end of the medium P from the conveying member 83 towards the upstream side in the conveying direction is approximately the same as the length of the medium P in the conveying direction. Furthermore, the conveying members 81, 82, and 83 resume conveying the medium P from the end side of the medium P with approximately the same amount of protrusion (i.e., the upstream end side in the conveying direction (specifically the right end side)).

[0320] In the structure (hereinafter referred to as Structure A) where the amount of protrusion from the rear end of the medium P towards the upstream side of the conveying direction from the conveying member 83 varies depending on the medium P, and the medium P is conveyed again from this protruding side, the time it takes for the conveying roller or other conveying parts located downstream of the conveying member 83 in the conveying direction to change during the re-conveying process due to the change in the amount of protrusion. Consequently, the conveying control of this conveying part can sometimes become complex. In contrast, in this embodiment, since the conveying of the medium P is stopped in a manner where the amount of protrusion from the conveying member 83 towards the upstream side of the conveying direction is approximately the same as the length of the medium P in the conveying direction, the conveying control during the re-conveying of the medium P can be simplified compared to the case of Structure A.

[0321] In this embodiment, the pressing member 120 supports the medium P whose side end is detected by the side end detection unit 98. Here, in a structure where the pressing member 120 does not support the side end of the detected medium P (hereinafter referred to as structure B), the posture of the side end of the medium P is prone to change. In contrast, in this embodiment, since the pressing member 120 supports the medium P whose side end is detected by the side end detection unit 98, the change in posture of the side end of the medium P can be suppressed compared to the case of structure B, and the side end of the medium P can be detected even after deflection and wrinkling are reduced in the width direction of the medium P. As a result, the detection accuracy of the side end of the medium is improved.

[0322] The pressing components 120(A), 120(B), 120(C), and 120(D) are respectively positioned upstream of the conveying direction of each sensor 92(A), 92(B), 91(A), and 91(B). Therefore, compared to the case where the pressing components 120(A), 120(B), 120(C), and 120(D) are respectively positioned downstream of the conveying direction of each sensor 92(A), 92(B), 91(A), and 91(B), since the medium P is detected in a supported state where the deflection of the medium P has been eliminated, the detection accuracy of the side end of the medium P is improved.

[0323] In this embodiment, the front and rear end detection units 90 detect the front and rear ends of the medium P when it is in a stretched state after the medium P is heated and before the medium P is re-imaged.

[0324] Therefore, compared to the case where the front and rear ends of the medium P being transported along the transport path are also detected for the medium that is being transported to the image forming unit 14 again after being heated, the detection accuracy of the front and rear ends of the medium P is improved.

[0325] In this embodiment, the detection device 30, which includes the front and rear end detection units 90, and the heating unit 19 are provided in different portions 18A and 18B of the housing 18. Therefore, compared with the case where the front and rear end detection units 90 and the heating unit 19 are provided in the same portion of the housing 18, the thermal impact on the front and rear end detection units 90 from the heating unit 19 can be reduced.

[0326] In this embodiment, the detection device 30, which includes the front and rear end detection units 90, is disposed below the heating unit 19. Therefore, compared to the case where the front and rear end detection units 90 are disposed above the heating unit 19, the thermal impact on the front and rear end detection units 90 from the heating unit 19 can be reduced.

[0327] (Example of a structural variation of the tensile medium P)

[0328] In this embodiment, the conveying components 81, 82, and 83, which convey the medium P in the first conveying direction and stop the conveying along the conveying path 80B, stretch the medium P in the stretching direction, but are not limited to this. For example, the structure could be such that the conveying components 81, 82, and 83 convey the medium P and stop the conveying, while a separately provided stretching unit stretches the medium P. The stretching unit could be, for example, a conveying component such as a conveying roller or a conveyor belt, or a component that uses suction force to stretch the medium P.

[0329] Furthermore, in this embodiment, after the conveying member 83 stops conveying the medium P, the conveying members 81 and 82 also stop conveying the medium P, thereby stretching the medium P in the stretching direction by the conveying members 81, 82, and 83, but this is not limited to this. For example, it may also be a structure where, after the conveying members 81, 82, and 83 simultaneously stop conveying the medium P, the conveying members 81, 82, and / or the conveying member 83 operates to stretch the medium. In addition, when the conveying members 81 and 82 operate, the drive rollers 84 and 85 rotate forward, and when the conveying member 83 operates, the drive roller 86 rotates in reverse.

[0330] (Modified examples of upstream conveying section 80X and downstream conveying section 80Y)

[0331] In this embodiment, the downstream conveying unit 80Y has a conveying member 81 and a conveying member 82 disposed upstream of the conveying member 81 in the conveying direction, but is not limited thereto. For example, the downstream conveying unit 80Y may also be a structure having only a single conveying member or the like. Specifically, the downstream conveying unit 80Y may, for example, be a structure having only a conveying member 82. In this structure, the medium P, including both the minimum and maximum dimensions, is stretched by the conveying member 82 and the conveying member 83.

[0332] Thus, in this embodiment, the smallest and largest media P can be stretched by the same conveying member or other conveying section. Furthermore, the downstream conveying section 80Y can have a structure with three or more conveying members or other conveying sections.

[0333] Furthermore, in this embodiment, the upstream conveying section 80X has only one conveying member 83, but it may also have multiple conveying members or other conveying sections. In this case, for example, a structure can be adopted in which the downstream conveying section 80Y has a single conveying section and the upstream conveying section 80X has a first conveying section and a second conveying section disposed upstream of the first conveying section in the conveying direction (hereinafter referred to as the first structure). In the first structure, it can be configured such that the first conveying section and the downstream conveying section 80Y stretch a medium P with a conveying direction length less than a predetermined length, and the second conveying section and the downstream conveying section 80Y stretch a medium P with a conveying direction length greater than or equal to a predetermined length.

[0334] Furthermore, in the first structure, for example, a front-end sensor, serving as the detection unit for the front end of the detection medium P, can be provided instead of the rear-end sensor 99. The medium P is stopped based on the timing at which the front-end sensor detects the front end of the medium P. Moreover, by stopping the medium P based on the timing of the front-end sensor's detection of the front end of the medium P, the downstream conveying unit 80Y can stop the conveying of the medium P in such a way that the amount of protrusion of the front end of the medium P from the downstream conveying unit 80Y in the downstream conveying direction is approximately the same as the length of the medium P in the conveying direction.

[0335] Furthermore, in a modified example where the detection device 30 is positioned downstream of the conveying direction of the conveying path 80A and upstream of the conveying direction of the transfer position TA, the conveying components 81, 82, and 83 can convey the medium P again from the end side (i.e., the downstream side of the conveying direction) where the protrusion of the medium P is approximately the same.

[0336] (Based on changes in the tensile force of conveying components 81, 82, and 83)

[0337] The conveying components 81, 82, and 83 can also change the tensile force according to the characteristics of the medium P. Specifically, the conveying components 81, 82, and 83 can also change the tensile force according to the type of medium P. Types of medium P include those related to thickness, such as thin paper, plain paper, and thick paper, and those based on the presence or absence of coating, such as coated paper and uncoated paper. Characteristics of medium P include its type, rigidity, thickness, weight per unit area, size, weight, temperature, and humidity (moisture content).

[0338] Specifically, the conveying components 81, 82, and 83 are configured, for example, to apply a first tensile force to a first type of medium P and to apply a second tensile force stronger than the first tensile force to a second type of medium that has a higher rigidity than the first type of medium P.

[0339] The tensile force is changed by altering the second elapsed time (i.e., the time difference) from when the conveying component 83 stops rotating until the rotation of the conveying components 81 and 82 stops. That is, the tensile force is increased by extending the second elapsed time.

[0340] In this structure, the tensile force is varied according to the type of medium P, and multiple types of medium P are conveyed along the conveying path 80B. Along this conveying path 80B, a detection device 30 (specifically, a front and rear end detection unit 90) detects the front and rear ends of the various mediums P when conveying is stopped and under tension. Within this detection device 30, the tensile force is varied according to the type of medium P. Then, the image forming unit 14 forms an image on the various mediums P based on the detection results from the detection device 30.

[0341] In a structure where the tensile force of the conveying components 81, 82, and 83 is varied according to the characteristics of the medium P, wrinkles in the medium P can be suppressed compared to the case where the tensile force of the conveying components 81, 82, and 83 is constant.

[0342] Furthermore, in this example, since the tensile force is changed according to the type of medium P in the detection device 30, it is possible to form an image appropriately according to the type of medium P compared to the case where image formation is performed based on the results obtained by detecting the front and rear ends of various medium Ps under a constant tensile force.

[0343] (A variation of an image formed on medium P)

[0344] In this embodiment, the front image, which is the first image, is formed on one surface of the medium P, and the back image, which is the second image, is formed on the other surface of the medium P, but it is not limited to this. It is also possible that the second image is formed on the surface of the medium P on which the first image is formed.

[0345] Furthermore, in this embodiment, the front image as the first image and the back image as the second image are formed by the same image forming unit 14, but they may also be formed by different image forming units.

[0346] Furthermore, as the first image, for example, an image formed by other units (e.g., an image forming unit separately provided in the image forming apparatus 10 relative to the image forming unit 14, and another image forming apparatus relative to the image forming apparatus 10) can be added or replaced to form an image that is formed on the medium P. As the first image, it is any image formed on the medium P before the detection of the end of the medium P is performed.

[0347] (A variation of the conveyor section 80)

[0348] In this embodiment, the connecting portions 743, 753, 763, drive sources 777, 778, and control device 160, which are connected to the connecting portions 843, 853, 863 of the drive rollers 84, 85, 86, are provided in the image forming apparatus body 11, but are not limited thereto. The connecting portions 743, 753, 763, drive sources 777, 778, and control device 160 may also be provided in the detection device 30.

[0349] In this embodiment, a structure is adopted in which the conveying component 81 and the conveying component 82 rotate using a common drive source 777, but it is not limited to this. For example, a structure in which the conveying component 81 and the conveying component 82 rotate using different drive sources may also be adopted.

[0350] Furthermore, in this embodiment, the conveying member 83 stops the conveying of the medium P in a manner in which the amount of protrusion of the rear end of the medium P from the conveying member 83 upstream in the conveying direction is approximately the same as the length of the medium P in the conveying direction, but this is not a limitation. For example, it may be a structure in which the amount of protrusion of the rear end of the medium P from the conveying member 83 upstream in the conveying direction varies depending on the medium P.

[0351] In this embodiment, drive rollers 84, 85, and 86 are used as rotating components, but the method is not limited to this. Rollers, rollers, belts, and pulleys can be used individually or in combination as rotating components. Furthermore, when a belt is used as a rotating component, the belt is wound around multiple rollers, receiving driving force from these rollers to complete the loop. Additionally, rotating components can also be components that are not driven by rotation; any component that rotates is acceptable.

[0352] In this embodiment, driven rollers 87, 88, and 89 are used as driven components, but the method is not limited to this. As driven components, they can be rollers, belts, pulleys, etc., as long as they are components that are driven by rotating components.

[0353] Furthermore, in this embodiment, drive rollers 84, 85, and 86, which are rotating components, are disposed on the detection device main body 40, and driven rollers 87, 88, and 89, which are driven components, are disposed in the units disposed on the upper side of the detection device main body 40, namely the first unit 31 and the second unit 32, but this is not limited to this. For example, it is also possible that driven components such as driven rollers 87, 88, and 89 are disposed on the detection device main body 40, and rotating components such as drive rollers 84, 85, and 86 are disposed in the first unit 31 and the second unit 32.

[0354] Furthermore, in this embodiment, the driven rollers 87, 88, 89 and roller portions 842, 852, 862 are configured such that, when viewed in a direction perpendicular to the image forming surface of the medium P, the sensors 93 and 94 are appropriately spaced apart in the front-to-back direction (i.e., the width direction of the medium P), but this is not a limitation. For example, the driven rollers 87, 88, 89 and roller portions 842, 852, 862 may also be configured such that, when viewed in a direction perpendicular to the image forming surface of the medium P, the sensors 93 and 94 are appropriately spaced apart in the transport direction. Alternatively, the driven rollers 87, 88, 89 and roller portions 842, 852, 862 may be configured in a position where the sensors 93 and 94 are not spaced apart.

[0355] In this embodiment, the first conveying direction is set to the left and the second conveying direction is set to the right, but it is not limited to this. For example, the first conveying direction and the second conveying direction can also be forward, backward, above, below, etc., and various directions can be used.

[0356] The second transport direction is the opposite direction to the first transport direction, but it is not limited to this. For example, the second transport direction can be a direction intersecting the first transport direction, as long as it is a direction different from the first transport direction. When the second transport direction intersects the first transport direction, the detection device 30 can employ a structure that flips the medium P in both directions using a Möbius rotation method. The Möbius rotation method refers to, for example, transporting the medium P by repeatedly turning it back and forth at a rate of 90 degrees each time when viewed in a direction perpendicular to the image forming plane of the medium P, thereby flipping the medium P in both directions. Furthermore, the second transport direction can also be, for example, the same direction as the first transport direction.

[0357] (A modified example of the pressing component 110)

[0358] In this embodiment, the pressing member 110 is configured such that, when viewed in a direction perpendicular to the image forming surface of the medium P, it is appropriately spaced from the sensor 93 in the front-to-back direction, but is not limited thereto. The pressing member 110 may also be configured such that, when viewed in a direction perpendicular to the image forming surface of the medium P, it is appropriately spaced from the sensor 93 in the transport direction. Furthermore, the pressing member 110 may also be configured in a position where it is not spaced from the sensor 93. For example, the pressing member 110 may be configured at a position opposite to the sensor 93 within a range that does not affect the detection of the sensor 93, or it may be configured at a position offset from that opposite position.

[0359] Furthermore, in this embodiment, the pressing member 110 presses the downstream end of the medium P detected by the sensor 93. However, a structure can be added or used instead of this structure, where the pressing member 110 presses one side end, the other side end, and the upstream end of the medium P detected by the sensors 91, 92, and 94, respectively. Additionally, since the pressing member 110 only needs to press the end that is the target of detection for the medium P, in a structure having an end that is not the target of detection, the pressing member 110 may not be required for that end.

[0360] Furthermore, the pressing member 110 is not limited to sheet-like elastic components such as resin films. The pressing member 110 can be any component that supports the material above the conveying surface 41A of the main body 40 of the detection device, and can be any type of protrusion such as a rib, a driving, driven, or non-rotating roller, belt, roller, or wheel. Furthermore, the component supporting the medium P can also be a component that supports the medium P by blowing or drawing air.

[0361] (A modified example of the pressing component 120)

[0362] In this embodiment, pressing members 120(A), 120(B), 120(C), and 120(D) are respectively disposed upstream of the conveying direction of each sensor 92(A), 92(B), 91(A), and 91(B), but are not limited thereto. For example, pressing members 120(A), 120(B), 120(C), and 120(D) may also be disposed downstream of the conveying direction of each sensor 92(A), 92(B), 91(A), and 91(B).

[0363] Furthermore, as an example of a support, it is not limited to the pressing member 120. As an example of a support, it can be any member that supports the medium P detected by the side end detection unit 98 at its opposite end; it can also be a protrusion such as a rib, or any roller, belt, roller, or wheel that is either driving, driven, or non-rotating. Furthermore, as an example of a support, it can also be a support that supports the medium P by blowing or sucking air or other gas.

[0364] Furthermore, in this embodiment, the structure may also be without a pressing member 120 that supports the medium P detected by the side end detection unit 98 at the side end.

[0365] (A variation of the opening / closing part 70)

[0366] In this embodiment, the opening / closing part 70 is disposed between sensors 91(A), 92(A) and sensors 91(B), 92(B), at a position where sensors 91 to 94 are not present, but it is not limited thereto. For example, the opening / closing part 70 may be disposed at a position where sensors 93 and 94 are not present and may open and close together with sensors 91 and 92. In addition, in this case, the positioning accuracy of the opening / closing part 70 needs to be configured so as not to affect the detection accuracy of sensors 91 and 92.

[0367] Furthermore, the detection device 30 may also be a conveying path 80A in the conveying section 80 that does not have an opening / closing part 70 (see reference). Figure 1 The structure with an open opening 77 that can be opened and closed.

[0368] (Modified examples of front and rear end detection units 90 and side end detection units 98)

[0369] In this embodiment, reflective light sensors are used as sensors 91 to 94, but the method is not limited to this. For example, transmissive light sensors can also be used as sensors 91 to 94. Furthermore, sensors 91 to 94, as detection units, can also be detection units that detect the ends of the medium P by contacting the ends of the medium P; various detection units can be used. For example, a detection unit that uses a contact member (e.g., a guide member) that contacts the side ends of the medium P can be used as a detection unit that detects the ends of the medium P by photographing the medium P. Furthermore, sensors 91 to 94 can also be cameras that detect the ends of the medium P by photographing the medium P. Moreover, even when the length of the medium P is determined based on the image captured by the camera, since this length is the distance between the ends of the medium P, it can also be said that the ends of the medium P have been detected.

[0370] In this embodiment, sensors 91 to 94 are respectively configured to intersect the end of the stretched medium P in the long side direction when viewed from a direction perpendicular to the image forming surface of the medium P, but are not limited thereto. For example, sensors 91 to 94 may be configured to intersect the end of the medium P in the short side direction. Furthermore, sensors 91 to 94 that do not have a long side direction may also be used (for example, sensors that are square when viewed from a direction perpendicular to the image forming surface of the medium P).

[0371] Furthermore, in this embodiment, the front and rear end detection units 90 and the side end detection units 98 detect one end of the medium P using multiple sensors, but are not limited thereto. For example, it may also be a structure with only one sensor to detect one end of the medium P.

[0372] Furthermore, in this embodiment, sensors 91 to 94 are disposed in the first unit 31 and the second unit 32, but are not limited thereto. For example, it is also possible for sensors 91 and 93 to be disposed in the detection device body 40 and for sensors 92 and 94 to be disposed in the first unit 31 and the second unit 32.

[0373] Furthermore, in this embodiment, a front and rear end detection unit 90 and a side end detection unit 98 are provided, but it is sufficient to provide at least a front and rear end detection unit 90.

[0374] The front and rear end detection units 90 can also be configured as follows: for the medium P with the largest length in the conveying direction, the front and rear ends of the medium P in a stretched state are detected; for the medium P with the smallest length in the conveying direction, the front and rear ends of the medium P are not detected. In this configuration, for example, the front and rear end detection units 90 detect the front and rear ends of the medium P in a stretched state for all media P, including the largest size (excluding the smallest size), and do not detect the front and rear ends of the smallest size medium P.

[0375] Furthermore, in this structure, for example, the size of the medium P is measured on the upstream side of the conveying direction of the detection device 30, and the front and rear end detection units 90 are used to determine whether to perform detection operations on the front and rear ends of the medium P based on the measurement results.

[0376] In this structure, since the front and rear end detection units 90 do not detect the front and rear ends of the medium P, which is the smallest size medium P with the smallest length in the conveying direction, the number of times the front and rear ends of the medium P are detected can be reduced compared to the case where the front and rear end detection units 90 always detect the front and rear ends of the medium P regardless of the length in the conveying direction of the medium P.

[0377] (A modified example of the configuration of the detection device 30)

[0378] In this embodiment, the detection device 30 is disposed inside the image forming apparatus body 11, but it is not limited thereto. The detection device 30 may also be disposed outside the image forming apparatus body 11. When the detection device 30 is disposed outside the image forming apparatus body 11, it may be disposed directly outside the image forming apparatus body 11, or it may be disposed indirectly by sandwiching other devices between it and the image forming apparatus body 11. Furthermore, the detection device 30 may also be disposed within other devices disposed within the image forming apparatus body 11. The detection device 30 only needs to cooperate or operate in conjunction with the image forming apparatus body 11 when necessary.

[0379] In this embodiment, the detection device 30, which includes the front and rear end detection units 90, and the heating unit 19 are provided in different parts 18A and 18B of the housing 18, but it is not limited thereto. For example, the detection device 30, which includes the front and rear end detection units 90, and the heating unit 19 are provided in the same part of the housing 18.

[0380] In this embodiment, the detection device 30, which includes the front and rear end detection units 90, is disposed on the lower side of the heating unit 19, but it is not limited thereto. It is also possible that the detection device 30, which includes the front and rear end detection units 90, is disposed on the upper side of the heating unit 19.

[0381] Furthermore, in this embodiment, the detection device 30 is disposed in the transport path 24 upstream of the supply position 25A (specifically, transport path 80A) in the transport direction where a new medium P is supplied to the image forming unit 14, but is not limited thereto. For example, the following structure may be added or replaced with the detection device 30 disposed in the transport path 24 (specifically, transport path 80A): the detection device 30 is disposed downstream in the transport direction of the transport path 80A and upstream in the transport direction of the supply position 25A. In this structure, for example, the detection device 30 is disposed at a position where it stops to maintain the interval between the medium P supplied from the medium receiving unit 12 to the supply position 25A. In the transport unit 80 in this structure, for example, the transport of the medium P with the frontal image formed in the first transport direction is stopped and the medium P is stretched. After the medium P stops, the transport of the medium P is restarted in the second transport direction, which is the same direction as the first transport direction, toward the image forming unit 14 (specifically, the transfer position TA). In this structure, the detection device 30 configured in the transport path 80A may be omitted, and the transport path 24 may be configured as a transport path that does not perform the flipping of the medium P. In this structure, a second image is formed again on the surface (front side) on which the first image is formed. Thus, the second image may also be an image formed on the surface on which the first image is formed.

[0382] Furthermore, for example, the detection device 30 disposed in transport path 24 (specifically transport path 80A) can be replaced with a structure in which the detection device 30 is disposed downstream in the transport direction than the supply position 25A. In this structure, for example, the detection device 30 is disposed at a position where the transport timing of the medium P being transported to the image forming unit 14 (specifically the transfer position TA) is stopped to adjust the transport timing. In the transport unit 80 of this structure, for example, the transport of the medium P with the frontal image formed in the first transport direction stops and the medium P is stretched. After the medium P stops, the transport of the medium P is restarted in the second transport direction, which is the same as the first transport direction, toward the image forming unit 14 (specifically the transfer position TA).

[0383] (Structure when the delivery mechanism 250 with suction section 252 is used)

[0384] like Figure 24 As shown, a structure can also be used in which the medium P stored in the medium receiving section 12 is delivered by a delivery mechanism 250 having a suction section 252. For example... Figure 24 and Figure 25 As shown, the delivery mechanism 250 includes: a suction section 252 that draws medium P from the medium receiving section 12; and a delivery roller 245 that delivers the medium P drawn by the suction section 252. The delivery roller 245 is an example of the delivery section.

[0385] Among the 250 sending organizations, such as Figure 25 As shown in (A) and (B), the suction section 252 disposed above the medium receiving section 12 adsorbs the medium P onto its lower surface by suction, as... Figure 25 As shown in (C), the suction unit 252 moves toward the delivery roller 245, thereby transferring the medium P to the delivery roller 245. Then, the delivery roller 245 rotates, thereby delivering the medium P. The medium P delivered by the delivery roller 245 is transported on the transport path 21A from the medium receiving unit 12 to the image forming unit 14.

[0386] In this structure, such as Figure 24As shown, in addition to the detection device 30 arranged in part 18B of the housing 18, a detection device 30 can be added or replaced by a detection device 30 arranged, for example, on the conveying path 21A. In this structure, on the conveying path 21A where the medium P fed by the feed roller 245 is conveyed, the front and rear end detection units 90 of the detection device 30 detect the front and rear ends of the medium P in a stretched state. Furthermore, the image forming unit 14 forms an image on the medium detected by the front and rear end detection units 90. The front and rear end detection units 90 detect the front and rear ends of the medium P when the front and rear ends of the medium P are separated from the feed roller 245 and the front and rear ends are located between the feed roller 245 and the image forming unit 14.

[0387] Therefore, compared with the case where the front and rear end detection units 90 detect the front and rear ends of the medium P in the suction unit 252, the suction effect on the detection unit from the suction unit 252 can be reduced.

[0388] This invention is not limited to the embodiments described above, and various modifications, alterations, and improvements can be made without departing from its spirit. For example, multiple variations shown above can be appropriately combined to form the invention.

[0389] In the above embodiments, processor refers to processor in a broad sense, including general-purpose processors (e.g., central processing unit (CPU) and special-purpose processors (e.g., graphics processing unit (GPU), application-specific integrated circuit (ASIC), field-programmable gate array (FPGA), programmable logic device, etc.).

[0390] Furthermore, the operation of the processor in the above embodiments can be performed not only by a single processor, but also collaboratively by multiple processors located in physically separate positions. Moreover, the order of the processor's actions is not limited to the order described in the above embodiments and can be appropriately modified.

[0391] Furthermore, the program used in the above embodiments can be provided in a state stored in computer-readable recording media such as magnetic recording media (magnetic tape, disks (HDD, FDD, etc.), optical recording media (CD, DVD, etc.), optical-magnetic recording media, and semiconductor memory). Additionally, such a program can also be pre-stored on an external server such as a cloud server and downloaded via communication lines such as the Internet.

Claims

1. A detection device, comprising: The transport path, which is used to transport the medium; The detection unit detects the front and rear ends of the medium in the conveying path when it is stopped from being conveyed and is stretched in the stretching direction along the conveying path. An upstream conveying unit that conveys the medium in the conveying direction along the conveying path and stops the conveying; and A downstream conveying unit, disposed downstream of the upstream conveying unit in the conveying direction, conveys the medium in the conveying path in the conveying direction and stops the conveying. The medium is one that can flex during transport. The upstream conveying section and the downstream conveying section stretch the medium along the stretching direction.

2. The detection device according to claim 1, wherein, The downstream conveying section and the upstream conveying section convey the medium. After the upstream conveying section stops conveying, the downstream conveying section stops conveying. Thus, when the conveying stops, the downstream conveying section and the upstream conveying section stretch the medium along the stretching direction.

3. The detection device according to claim 1 or 2, wherein, The upstream conveying section or the downstream conveying section has: First transport unit; and The second conveying unit is located upstream of the first conveying unit in the conveying direction.

4. The detection device according to claim 3, wherein, The downstream conveying section includes the first conveying section and the second conveying section. The second conveying section and the upstream conveying section convey media whose length in the stretching direction is less than a predetermined length. The first conveying section and the upstream conveying section are for conveying media with a length in the stretching direction that is more than a predetermined length.

5. The detection device according to claim 3, wherein, The first conveying section and the second conveying section are rollers that rotate using a common drive source.

6. The detection device according to claim 1 or 2, wherein, The upstream or downstream conveying unit changes the tensile force according to the characteristics of the medium.

7. The detection device according to claim 1 or 2, wherein, The upstream or downstream conveying section stops in approximately the same manner, with the amount of the medium's end protruding from the upstream or downstream conveying section being independent of the length of the medium's conveying direction. The medium is then conveyed again from the end side, where the protrusion becomes approximately the same.

8. The detection device according to claim 1 or 2, wherein, The detection unit detects the front and rear ends of a medium whose conveying length is more than a predetermined length, when the medium has been stopped from being conveyed and is stretched in the stretching direction. The detection unit does not detect the front and rear ends of media whose length in the conveying direction is less than a predetermined length.

9. The detection device according to claim 1 or 2, comprising: A side-end detection unit that detects the side end of the medium while the front and rear ends are detected by the detection unit; and A support portion that supports the side end of the medium detected by the side end detection portion.

10. The detection device according to claim 9, wherein, The support portion is configured along the side end detection portion upstream of the side end detection portion in the conveying direction.

11. An image forming apparatus comprising: An image forming unit that forms an image on a medium; The heating unit heats the medium on which the image is formed; A transport path for transporting the heated medium; The detection unit detects the front and rear ends of the medium in the conveying path when it is stopped from being conveyed and is stretched in the stretching direction along the conveying path. An upstream conveying unit that conveys the medium in the conveying direction along the conveying path and stops the conveying; as well as A downstream conveying unit, disposed downstream of the upstream conveying unit in the conveying direction, conveys the medium in the conveying path in the conveying direction and stops the conveying. The medium is one that can flex during transport. The upstream conveying section and the downstream conveying section stretch the medium along the stretching direction. The detection unit detects the front and rear ends of the medium after the medium is heated.

12. An image forming apparatus comprising: An image forming unit that forms an image on a medium; The heating unit heats the medium on which the image is formed; A transport path for transporting the heated medium; The detection unit detects the front and rear ends of the medium in the conveying path when it is stopped from being conveyed and is stretched in the stretching direction along the conveying path. An upstream conveying unit that conveys the medium in the conveying direction along the conveying path and stops the conveying; as well as A downstream conveying unit, disposed downstream of the upstream conveying unit in the conveying direction, conveys the medium in the conveying path in the conveying direction and stops the conveying. The medium is one that can flex during transport. The upstream conveying section and the downstream conveying section stretch the medium along the stretching direction. The detection unit and the heating unit are disposed in different parts of a housing that is divided into multiple parts.

13. The image forming apparatus according to claim 12, wherein, The detection unit is located on the lower side of the heating unit.

14. An image forming apparatus comprising: A suction unit that draws the medium from a medium receiving unit that receives the medium; The delivery section delivers the medium drawn out by the suction section. The detection unit detects the front and rear ends of the medium in a conveying path where the medium being conveyed by the delivery unit is stopped and is stretched in the stretching direction along the conveying path. An image forming unit that forms an image on the medium detected by the detection unit; An upstream conveying unit that conveys the medium in the conveying direction along the conveying path and stops the conveying; as well as A downstream conveying unit, disposed downstream of the upstream conveying unit in the conveying direction, conveys the medium in the conveying path in the conveying direction and stops the conveying. The medium is one that can flex during transport. The upstream conveying section and the downstream conveying section stretch the medium along the stretching direction. The detection unit detects the front and rear ends of the medium when the front and rear ends are detached from the delivery unit and the front and rear ends are located between the delivery unit and the image forming unit.

15. An image forming apparatus comprising: The transport path is designed to transport various media. A detection device that detects the front and rear ends of the various media in the conveying path when they are stopped from being conveyed and are stretched in the stretching direction along the conveying path. An image forming unit that forms an image on the various media based on the detection result of the detection device; An upstream conveying unit that conveys the medium in the conveying direction along the conveying path and stops the conveying; as well as A downstream conveying unit, disposed downstream of the upstream conveying unit in the conveying direction, conveys the medium in the conveying path in the conveying direction and stops the conveying. The medium is one that can flex during transport. The upstream conveying section and the downstream conveying section stretch the medium along the stretching direction. The detection device changes the tensile force according to the type of medium.

16. A computer-readable medium storing a program that causes a computer to perform processing, wherein, The process includes the following steps: The medium is stretched in a stretching direction along the conveying path by conveying a medium that can flex during conveying in the conveying direction in the conveying path and stopping the conveying, and by a downstream conveying section disposed on the downstream side of the upstream conveying section that conveys the medium in the conveying direction in the conveying path and stops the conveying. as well as The front and rear ends of the medium are detected in the conveying path when it is stopped and stretched in the stretching direction.

17. A detection method, wherein, The detection method comprises the following steps: The medium is stretched in a stretching direction along the conveying path by conveying a medium that can flex during conveying in the conveying direction in the conveying path and stopping the conveying, and by a downstream conveying section disposed on the downstream side of the upstream conveying section that conveys the medium in the conveying direction in the conveying path and stops the conveying. as well as The front and rear ends of the medium are detected in the conveying path when it is stopped and stretched in the stretching direction.

18. A computer program product comprising a program that causes a computer to perform processing, wherein, The process includes the following steps: The medium is stretched in a stretching direction along the conveying path by conveying a medium that can flex during conveying in the conveying direction in the conveying path and stopping the conveying, and by a downstream conveying section disposed on the downstream side of the upstream conveying section that conveys the medium in the conveying direction in the conveying path and stops the conveying. as well as The front and rear ends of the medium are detected in the conveying path when it is stopped and stretched in the stretching direction.

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