Image forming device

Abstract

To provide an image forming device capable of detecting a jammed recording medium even in a high temperature environment.SOLUTION: An image forming device 1 according to the invention includes: an image forming part 25, an electrical contact point 61, a contact part 62, and a determination part 51. The image forming part 25 forms an image on the sheet P to be conveyed. The electrical contact 61 is disposed in the middle of the transport path 31 of the sheet P and has flexibility. The contacts parts 62 contact the electrical contact point 61 to form a conductive path 60. Based on the state of the conductive path 60, the determining unit 25 determines whether the sheet P transported along the transport path 31 is in a transport state or a stagnant state.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] The drying device described in Patent Document 1 includes a main body frame, a housing, a heating element, and a drawer section. The housing is filled into the main body frame to define a drying area. The heating element is provided within the housing to dry the recording paper. The drawer section draws out the housing in the conveying direction of the recording paper. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-355099 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the drying device described in Patent Document 1, the internal temperature becomes high, making it difficult to place an optical sensor, which is a non-contact detection device, inside the drying device. Because the optical sensor uses an integrated circuit, its use in high-temperature environments is limited for reliability reasons. In other words, there is a risk that paper jams cannot be detected in high-temperature environments.

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an image forming apparatus that is capable of detecting a jam of a recording medium even in a high-temperature environment. [Means for solving the problem]

[0006] The image forming apparatus according to the present invention includes an image forming unit, an electrical contact, a contact unit, and a determination unit. The image forming unit forms an image on a recording medium being transported. The electrical contact is disposed midway along a transport path for the recording medium and is flexible. The contact unit contacts the electrical contact to form a conductive path. The determination unit determines whether the recording medium being transported along the transport path is in a transport state or a stagnant state based on the state of the conductive path. Effect of the Invention

[0007] According to the image forming apparatus of the present invention, a jam of the recording medium can be detected even in a high temperature environment. [Brief description of the drawings]

[0008] [Figure 1] 1 is a diagram showing a configuration of an image forming apparatus according to an embodiment of the present invention; [Diagram 2] FIG. 4 is a diagram showing a configuration of a second conveying device according to the embodiment. [Diagram 3] FIG. [Figure 4] FIG. 4 is a side view showing a detection unit in a conductive state. [Diagram 5] FIG. 4 is a side view showing the detection portion in a non-conductive state. [Figure 6] 1 is a block diagram showing an image forming apparatus according to an embodiment of the present invention; [Figure 7] 13 is a flowchart showing a sheet jamming determination process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and description thereof will not be repeated.

[0010] First, an image forming apparatus 1 will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a diagram showing the configuration of the image forming apparatus 1 according to the present embodiment. Fig. 2 is a diagram showing the configuration of a second conveying device 3 according to the present embodiment.

[0011] As shown in FIG. 1, the image forming apparatus 1 includes a first conveying device 2, a second conveying device 3, a third conveying device 4, and a control unit 5.

[0012] The second conveying device 3 is connected to the first conveying device 2. The third conveying device 4 is connected to the second conveying device 3. The second conveying device 3 is connected to the downstream side of the conveying direction of the sheet P relative to the first conveying device 2. The third conveying device 4 is connected to the downstream side of the conveying direction of the sheet P relative to the second conveying device 3. The sheet P corresponds to, for example, a "recording medium."

[0013] The first conveying device 2 acquires image data from a document. Alternatively, the first conveying device 2 acquires image data from an external server, cloud, or terminal. The first conveying device 2 forms an image on a sheet P based on the image data and outputs the image. The first conveying device 2 may be a device that combines an image data transmission / reception function, an image reading function, and an image forming function. The first conveying device 2 has functions such as a scanner, a printer, a copier, a telephone, a printing machine, and a facsimile.

[0014] The cloud is a form of utilization in which computer resources are provided via a computer network such as the Internet, and includes, for example, applications, a platform, and an infrastructure.

[0015] The server stores the data and provides the corresponding data when requested via a communication line.

[0016] The first conveying device 2 forms an image on the sheet P.

[0017] The first conveying device 2 has a feeding section 20, a feeding section 21, a conveying section 22, a conveying section 23, a conveying section 24, an image forming section 25, a conveying belt 26, and a double-sided conveying path 27.

[0018] The feeding section 20 stores the sheets P and feeds the sheets P.

[0019] The feeding section 21 mainly performs manual feeding.

[0020] The transport section 22 transports the sheet P fed from the feeding section 20 toward the image forming section 25. The transport section 22 includes a transport roller 22A.

[0021] The conveying section 23 conveys the sheet P manually fed from the feeding section 21 toward the image forming section 25.

[0022] The conveying section 24 conveys the sheet P to the second conveying device 3.

[0023] The image forming unit 25 forms an image on the conveyed sheet P. The image forming unit 25 forms an image on the sheet P with toner or ink. When the first conveying device 2 is of an electrophotographic system, the image forming unit 25 includes, for example, a photoconductor, a charging device, an exposure device, a developing device, a transfer device, a cleaning device, and a static elimination device.

[0024] The photoconductor is, for example, a photoconductor drum. The photoconductor drum has a photosensitive layer on its outer circumferential surface. Examples of the photoconductor drum are a selenium drum and an OPC (Organic Photoconductor).

[0025] The charging device charges the photosensitive layer of the photoreceptor to a predetermined potential. One example of the charging device is a corona discharger.

[0026] The exposure device irradiates the photosensitive layer of the photoconductor with laser light to expose it. The exposure device exposes the photosensitive layer of the photoconductor based on image data. As a result, an electrostatic latent image is formed on the photoconductor. An example of the exposure device is an LED (Light Emitting Diode).

[0027] The developing device contains, for example, a two-component developer containing a carrier made of a magnetic material and a toner. The developing device develops an electrostatic latent image formed on the photoreceptor by the toner to form a toner image on the photoreceptor. The transfer device transfers the toner image on the photoreceptor to a sheet P. The cleaning device removes residual toner remaining on the photoreceptor after transfer. The static eliminator eliminates static electricity from the photoreceptor.

[0028] When the first conveying device 2 is an inkjet printer, the image forming unit 25 includes, for example, an ink cartridge, an ink tank, a pump, a head, a nozzle, and an electrode.

[0029] The ink cartridges and ink tanks store water-based inks of various colors, for example, Y (yellow), M (magenta), C (cyan), and Bk (black).

[0030] The pump supplies ink from the ink tank to the head.

[0031] A large number of nozzles that form pixels are arranged in the head. Ink of a color that corresponds to the image data is supplied to the head from an ink tank based on the image data. The ink is ejected from the nozzles toward the sheet P.

[0032] The electrodes include, for example, a charging electrode and a deflection electrode. The charging electrode charges the ink ejected from the nozzle. The deflection electrode controls the flying direction of the charged ink.

[0033] The conveyor belt 26 is disposed opposite the nozzles of the head, and conveys the sheet P. An image is formed on the sheet P conveyed by the conveyor belt 26 with ink ejected from the nozzles of the head.

[0034] The double-sided conveying path 27 inverts the print surface of the sheet P. The double-sided conveying path 27 conveys the sheet P with the print surface inverted to the image forming unit 25. The double-sided conveying path 27 changes the state of the sheet P from a state in which the print surface is face-up to a state in which the print surface is face-down.

[0035] When the first conveying device 2 is of an electrophotographic system, a fixing device may be disposed in the second conveying device 3. The fixing device applies heat and pressure to the toner image developed on the sheet P to fix the toner image to the sheet P. The fixing device has, for example, a fixing roller, a heater, and a press roller.

[0036] The fixing roller is a hollow cylindrical roller. The fixing roller is pressed against a press roller. The press roller and the fixing roller form a nip portion. The press roller is rotationally driven by a drive unit (not shown). The press roller rotates the fixing roller.

[0037] The heater receives power from a power source (not shown) and heats the fixing roller. The heater is disposed close to the inner peripheral surface of the fixing roller. The sheet P conveyed to the fixing device passes through the nip portion and is heated by the heater, so that the toner image is fixed.

[0038] 1, the third conveying device 4 discharges the sheet P conveyed from the second conveying device 3. The third conveying device 4 may include a paper discharge tray 40 for accommodating the discharged sheet P.

[0039] As shown in FIG. 2, the second conveyance device 3 includes a heating section 30, a conveyance section 31, a conveyance roller 32, a switching section 33, a first drum conveyance section 34, a second drum conveyance section 35, and a detection section 6.

[0040] The heating section 30 heats the sheet P on which an image is formed. The heating section 30 has a heater 30A and a support section 30B. The heating section 30 is partitioned into a predetermined region including the heater 30A and the support section 30B.

[0041] The heater 30A has a heat source for heating air and a blower for blowing out the heated air. The heater 30A supplies radiant heat to the sheet P conveyed into the second conveying device 3.

[0042] The support portion 30B is, for example, a belt conveyor stretched between the driving roller 30a and the driven roller 30b. The support portion 30B supports the sheet P from below. The support portion 30B has, for example, a slit extending in the left-right direction that separates the front portion from the rear portion in the front-rear direction. The support portion 30B transports the heated sheet P.

[0043] 2, the conveying section 31 includes a reversing conveying path 31A, a reversing conveying path 31B, a reversing conveying path 31C, a first evacuation conveying path 31D, a first evacuation conveying path 31E, a first U-turn conveying path 31F, a first discharge conveying path 31G, and a first discharge conveying path 31H. The conveying section 31 corresponds to, for example, a "conveying path."

[0044] The sheet P conveyed from the first conveying device 2 is reversed toward the first conveying device 2 by the reverse conveying path 31A, the reverse conveying path 31B, and the reverse conveying path 31C.

[0045] The reverse transport path 31A is formed extending in the M direction (arrow left direction) from the transport section 24 of the first transport device 2. The reverse transport path 31A includes a support section 30B, a first transport roller 32A, and a second transport roller 32B.

[0046] The first transport roller 32A sends the sheet P to the support unit 30B. The first transport roller 32A is disposed at a position upstream of the heating unit 30. The first transport roller 32A receives the sheet P from the transport unit 24 via a feed roller 24A. The first transport roller 32A sends the sheet P received from the roller 24A in the M direction.

[0047] The second transport roller 32B receives the sheet P from the support unit 30B. The second transport roller 32B is disposed at a downstream position from the heating unit 30. The second transport roller 32B sends the sheet P received from the support unit 30B in the M direction.

[0048] That is, the support section 30B receives the sheet P from the first transport rollers 32A. The support section 30B sends out the sheet P to the second transport rollers 32B. The sheet P discharged from the transport section 24 of the first transport device 2 is transported in the M direction on the reverse transport path 31A with the heating section 30 interposed therebetween.

[0049] The reversing conveying path 31B is connected to the reversing conveying path 31A, and branches off from the reversing conveying path 31A in the N direction (for example, from the arrow downward to the arrow right direction) into a first discharge conveying path 31H. The sheet P conveyed in the M direction on the reversing conveying path 31A is conveyed in the N direction on the reversing conveying path 31B while being reversed.

[0050] The reversing conveying path 31C is connected to the reversing conveying path 31B. The sheet P reversed in the reversing conveying path 31B continues to be conveyed in the N direction on the reversing conveying path 31C.

[0051] The first evacuation conveying path 31D and the first evacuation conveying path 31E are connected to the reversing conveying path 31A, the reversing conveying path 31B, and the reversing conveying path 31C. The sheet P is conveyed through the reversing conveying path 31A, the reversing conveying path 31B, and the reversing conveying path 31C, and then conveyed to the first evacuation conveying path 31D and the first evacuation conveying path 31E.

[0052] The first evacuation conveying path 31D is connected to the reversing conveying path 31C at a point where the switching unit 33C is disposed. The first evacuation conveying path 31D extends to the first drum conveying unit 34 in the direction of the arrow O (for example, to the right of the arrow).

[0053] The first evacuation conveying path 31E is connected to the first evacuation conveying path 31D. The first evacuation conveying path 31E forms a part of the first drum conveying section 34. A part of the first evacuation conveying path 31D and the first evacuation conveying path 31E may form the first drum conveying section 34. The sheet P is conveyed in the direction of the arrow O from the first evacuation conveying path 31D to the first evacuation conveying path 31E.

[0054] The first U-turn transport path 31F branches off between the first evacuation transport path 31D and the first evacuation transport path 31E.

[0055] The first drum transport section 34 switches back the sheet P with its face down. Face down is a state in which the print surface of the sheet P faces downward. The first drum transport section 34 includes a first evacuation transport path 31D, a first evacuation transport path 31E, and a first U-turn transport path 31F. The sheet P transported to the first drum transport section 34 is evacuated to the first evacuation transport path 31E.

[0056] The sheet P switched back from the first retreat conveying path 31E is conveyed along the first U-turn conveying path 31F toward the first conveying device 2. The sheet P conveyed to the first conveying device 2 has the non-printed side printed, and is double-sided printed.

[0057] The first evacuation transport path 31D and the first evacuation transport path 31E have a drum shape.

[0058] Next, as shown in FIG. 2, the conveying section 31 further has a first discharge conveying path 31G, a first discharge conveying path 31H, a second evacuation conveying path 31I, a second evacuation conveying path 31J, a second U-turn conveying path 31K, and a second U-turn conveying path 31L.

[0059] The first discharge conveying path 31G and the first discharge conveying path 31H are connected to the third conveying device 4. The third conveying device 4 is disposed on the opposite side of the first conveying device 2 with respect to the second conveying device 3.

[0060] The first discharge conveying path 31G and the first discharge conveying path 31H branch off from the first U-turn conveying path 31F. The sheet P is switched back and conveyed in the direction of the arrow Q from the first retreat conveying path 31E towards the third conveying device 4.

[0061] The first discharge conveying path 31G is connected to the first discharge conveying path 31H. The first discharge conveying path 31H extends to the third conveying device 4 shown in FIG.

[0062] The second drum transport section 35 processes the next sheet P while the first drum transport section 34 processes the sheet P. The second drum transport section 35 switches back the sheet P face-down, similar to the first drum transport section 34. The second drum transport section 35 includes a second evacuation transport path 31I, a second evacuation transport path 31J, and a second U-turn transport path 31K. The second evacuation transport path 31J is continuous with the second evacuation transport path 31I, and transports the sheet P in the direction of the arrow R.

[0063] The second evacuation conveying path 31I is continuous with the reversing conveying path 31C. The second evacuation conveying path 31I branches off from the first evacuation conveying path 31D. The second evacuation conveying path 31I retracts the sheet P conveyed by the reversing conveying path 31A, the reversing conveying path 31B, and the reversing conveying path 31C.

[0064] The second U-turn conveying path 31K and the second U-turn conveying path 31L branch off from the second evacuation conveying path 31I and the second evacuation conveying path 31J at a point where the switching unit 33F is disposed.

[0065] The second U-turn conveying path 31K and the second U-turn conveying path 31L convey the sheet P switched back from the second retreat conveying path 31J toward the first conveying device 2.

[0066] The first discharge conveying path 31G and the first discharge conveying path 31H branch off from the second U-turn conveying path 31K and the second U-turn conveying path 31L at a point where the switching unit 33E is disposed.

[0067] The first discharge conveying path 31G and the first discharge conveying path 31H convey the sheet P switched back from the second retreat conveying path 31J toward the third conveying device 4.

[0068] The second evacuation conveying path 31I and the second evacuation conveying path 31J have a drum shape.

[0069] Next, the detection unit 6 will be described with reference to Fig. 3 to Fig. 5. Fig. 3 is a plan view showing the detection unit 6. Fig. 4 is a side view showing the detection unit 6 in a conductive state. Fig. 5 is a side view showing the detection unit 6 in a non-conductive state.

[0070] The detection unit 6 electrically detects the presence or absence of the sheet P. The detection unit 6 is disposed inside the heating unit 30. As shown in Fig. 4 and Fig. 5, the detection unit 6 has an electrical contact 61 and a contact portion 62. The electrical contact 61 and the contact portion 62 change states between a contact state and a non-contact state as the sheet P is transported.

[0071] The electrical contact 61 is disposed midway through the conveying section 31 in the left-right direction. The electrical contact 61 is disposed below the conveying section 31 in the up-down direction. The electrical contact 61 is particularly disposed below a portion corresponding to the support section 30B that supports the sheet P. The electrical contact 61 has a converging section 611 and a holding section 612. The electrical contact 61 is flexible. The contact section 62 and a portion of the electrical contact 61 that contacts the sheet P are flexible.

[0072] As shown in Fig. 4, the contact portion 62 contacts the electrical contact 61 to form the conductive path 60. The contact portion 62 is disposed above the conveying portion 31 in the up-down direction. When the electrical contact 61 and the contact portion 62 are in contact with each other, the conductive path 60 is in a conductive state. As shown in Figs. 3 and 5, when the electrical contact 61 and the contact portion 62 are not in contact with each other, the conductive path 60 is in a non-conductive state. The conductive state changes to a non-conductive state when the sheet P passes between the electrical contact 61 and the contact portion 62.

[0073] Next, a control system of the image forming apparatus 1 will be described with reference to Fig. 6. Fig. 6 is a block diagram showing the image forming apparatus 1 according to this embodiment.

[0074] As shown in FIG. 6, the image forming apparatus 1 further includes a storage unit 52. The storage unit 52 is configured with a RAM (Random Access Memory) and a ROM (Read Only Memory). Specifically, the storage unit 52 includes a main storage device such as a semiconductor memory, and an auxiliary storage device such as a semiconductor memory, a solid state drive, and / or a hard disk drive. The storage unit 52 stores a control program for controlling the operation of each unit of the image forming apparatus 1. The storage unit 52 stores setting information input by operating an operation panel (not shown).

[0075] The control unit 5 is a hardware circuit. The hardware circuit includes a processor such as a CPU (Central Processing Unit). The control unit 5 controls the image forming unit 25, the heating unit 30, the detection unit 6, and the storage unit 52 by executing a control program stored in the storage unit 52.

[0076] 6, the control unit 5 has a determination unit 51. The processor of the control unit 5 executes a computer program stored in the storage unit 52 to function as the determination unit 51.

[0077] The determination unit 51 determines whether the sheet P conveyed through the conveying unit 31 is in a conveying state or a stuck state based on the state of the conductive path 60. The sheet P is conveyed between the electrical contact 61 and the contact unit 62. The conductive state changes to a non-conductive state when the sheet P passes between the electrical contact 61 and the contact unit 62. The sheet P directly contacts the electrical contact 61, changing the conductive path 60 between a conductive state and a non-conductive state. In other words, no integrated circuit that is easily affected by temperature is required. As a result, a jam of the sheet P can be detected even in a high-temperature environment.

[0078] 2, the electrical contacts 61 and the contact portion 62 are disposed inside the heating portion 30. The electrical contacts 61 and the contact portion 62 constitute a contact-type detection device, so that a jam of the sheet P can be detected even inside the heating portion 30, which is at a high temperature. The support portion 30B has a slit extending in the left-right direction formed in the middle portion in the front-rear direction. The electrical contacts 61 and the contact portion 62 are disposed in correspondence with the slit extending in the left-right direction of the support portion 30B.

[0079] As shown in Figures 4 and 5, when the sheet P passes between the electrical contact 61 and the contact portion 62, the electrical contact 61 comes into contact with the non-image forming surface PB of the sheet P. There is no effect on the image forming surface PA of the sheet P. In addition, since the electrical contact 61 is flexible, even if the electrical contact 61 interferes with the sheet P, the electrical contact 61 deforms. As a result, the transport of the sheet P is not hindered. Incidentally, the electrical contact 61 is flexible enough to be deformed when it interferes with the sheet P.

[0080] 2, the electrical contact 61 and the contact portion 62 are disposed between the heater 30A and the second transport roller 32B in the left-right direction. For example, even if the second transport device 3 has a switchback mechanism and is prone to sheet clogging, the transport state of the sheet P can be detected at a downstream position of the second transport device 3 where clogging of the sheet P is likely to occur. Also, the transport state of the sheet P can be detected at an upstream position of the location where clogging of the sheet P is likely to occur.

[0081] The electrical contact 61 is disposed below a predetermined area of ​​the conveying unit 31 in the up-down direction. The predetermined area of ​​the conveying unit 31 corresponds to a portion of the support unit 30B that supports the sheet P. As shown in FIGS. 4 and 5, the electrical contact 61 has a converging portion 611 and a holding portion 612.

[0082] The converging portion 611 is a brush-like assembly of hundreds to thousands of thin highly conductive metal pieces with diameters of several μm to several tens of μm. The converging portion 611 is, for example, a brush made of zirconium copper alloy. As described above, the conductive state and non-conductive state of the conductive path 60 can be easily switched while allowing the sheet P to be transported. Note that the converging portion 611 is not limited to a brush made of zirconium copper alloy. The converging portion 611 may be made of various metal brushes as long as it is at least capable of conducting the conductive path 60.

[0083] The holding portion 612 holds one end of the bundling portion 611. The holding portion 612 is formed, for example, by pressing an aluminum alloy plate material into a flat shape extending in the front-rear direction. One end of the bundling portion 611 is arranged in a flat shape in the front-rear direction and is fixed to the holding portion 612 so as not to come off. One end of the bundling portion 611 is electrically connected to the harness 63.

[0084] The contact portion 62 is disposed above the transport portion 31 in the up-down direction. The contact portion 62 is disposed, for example, in the middle portion of the support portion 30B in the front-rear direction. The contact portion 62 is, for example, a rectangular columnar structure made of a high conductivity metal. The contact portion 62 may be, for example, a zirconium copper alloy, similar to the converging portion 611. The contact portion 62 is disposed at a position where it comes into contact with the other end of the converging portion 611. The contact portion 62 is disposed to extend in the front-rear direction in correspondence with the other end of the converging portion 611.

[0085] Next, the sheet jam determination process performed by the control unit 5 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing an example of the process performed by the control unit 5. As shown in Fig. 7, the process performed by the control unit 5 includes steps S1 to S5. Steps S1 to S5 are performed by the processor of the control unit 5 executing a program.

[0086] 7, in step S1, the control unit 5 reads various pieces of information. The process proceeds to step S2.

[0087] In step S2, the control unit 5 determines whether the conductive path 60 is in a non-conductive state. If the control unit 5 determines that the conductive path 60 is not in a non-conductive state (No in step S2), the process proceeds to step S5. If the control unit 5 determines that the conductive path 60 is in a non-conductive state (Yes in step S2), a sheet P is present between the electrical contact 61 and the contact portion 62. In other words, since the conductive path 60 is in a non-conductive state, the control unit 5 determines that the sheet P is stuck in the detection unit 6. The process proceeds to step S3.

[0088] In step S3, the control unit 5 determines whether a sheet jam has occurred. The control unit 5 notifies the user of the sheet jam by using a notification unit (not shown). The process proceeds to step S4.

[0089] In step S4, the control unit 5 stops the heating by the heating unit 30. The process ends.

[0090] If the answer is No in step S2, then in step S5, the control unit 5 determines whether the conductive state is longer than the conveying cycle. If the control unit 5 determines that the conductive state is not longer than the conveying cycle (No in step S5), the sheet P is being conveyed at a steady speed, and the process ends. If the conductive state is not longer than the conveying cycle, no retention of the sheet P occurs upstream of the detection unit 6. If the control unit 5 determines that the conductive state is longer than the conveying cycle (Yes in step S2), the process proceeds to step S3. If the conductive state is longer than the conveying cycle, retention of the sheet P occurs upstream of the detection unit 6. There is a risk that the sheet P is retained in, for example, a switchback mechanism arranged upstream of the detection unit 6.

[0091] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments, and can be implemented in various forms without departing from the scope of the present invention. The drawings are mainly schematic illustrations of each component for ease of understanding, and the thickness, length, number, etc. of each component shown in the drawings are different from the actual ones due to the convenience of drawing. In addition, the materials, shapes, dimensions, etc. of each component shown in the above embodiments are merely examples, and are not particularly limited, and various modifications are possible within a scope that does not substantially deviate from the effects of the present invention.

[0092] (1) In the present embodiment, the support portion 30B is a belt conveyor stretched between the driving roller 30a and the driven roller 30b, but the present invention is not limited to this. The support portion 30B only needs to be able to support the sheet P from below, and may be supported by, for example, a conveying plate. It is also possible to omit the driving roller 30a and the driven roller 30b.

[0093] (2) In the present embodiment, the second conveying device 3 has a switchback function, but the present invention is not limited to this. The second conveying device 3 only needs to have at least a conveying function capable of conveying the sheet P, and the switchback function and the heating unit 30 may be omitted.

[0094] (3) In the present embodiment, an example has been described in which the electrical contact 61 is disposed below and the contact portion 62 is disposed above the electrical contact 61, but the present invention is not limited to this. The contact portion 62 may be disposed below the electrical contact 61. In addition, an example has been described in which the electrical contact 61 and the contact portion 62 are disposed inside the heating portion 30, but the present invention is not limited to this. The electrical contact 61 and the contact portion 62 may be disposed outside the heating portion 30 as long as they are located in the vicinity of the heating portion 30.

[0095] (4) In the present embodiment, an example in which the electrical contacts 61 are configured in a brush shape has been described, but the present invention is not limited to this. As long as the electrical contacts 61 are at least flexible, the electrical contacts 61 may be in a sheet shape. [Industrial Applicability]

[0096] The present invention can be used in the field of image forming apparatuses. [Explanation of symbols]

[0097] 1: Image forming device 25: Image forming section 30: Heating part 30B: Support part 32A: First conveyor roller 32B: Second conveyor roller 51: Judgment section 60: Conductive path 61: Electrical contacts 62: Contact part P: Seat PB: Non-image forming surface

Claims

1. an image forming section for forming an image on a conveyed recording medium; a flexible electrical contact that is disposed in the middle of a transport path of the recording medium; a contact portion that contacts the electrical contact to form a conductive path; a determination unit that determines whether the recording medium transported on the transport path is in a transport state or a retention state based on a state of the conductive path; An image forming apparatus comprising:

2. a heating unit that heats the recording medium on which the image is formed, The image forming apparatus according to claim 1 , wherein the electrical contact and the contact portion are disposed inside the heating portion.

3. the recording medium is conveyed between the electrical contacts and the contact portion; 3. The image forming apparatus according to claim 1, wherein the electrical contacts come into contact with a non-image-forming surface of the recording medium when the recording medium passes between the electrical contacts and the contact portion.

4. A first conveying roller disposed upstream of the heating unit; A second conveying roller disposed downstream of the heating unit; Further equipped with the heating unit has a heater and a support unit that supports the recording medium from below, The image forming apparatus according to claim 2 , wherein the electrical contact and the contact portion are disposed between the heater and the second transport roller.

5. 3. The image forming apparatus according to claim 1, wherein the electrical contact is brush-shaped.

Images