Transcription device, image forming apparatus

Abstract

To provide a transfer device which can prevent co-rotation of a transfer belt with respect to the rotation of a transfer cylinder in a time other than the time of image formation in such a structure that the transfer cylinder rotates in conjunction with a fixation roll.SOLUTION: A transfer device comprises: a transfer cylinder which rotates in conjunction with a fixation roll; a transfer belt which transfers an image to a medium while co-rotating with the transfer cylinder in a state of holding the medium with the transfer cylinder; a pressing member which is arranged in the transfer belt; and switching means which switches between the pressing state in which the pressing member is moved and the transfer belt is pressed against the transfer cylinder and the separation state in which the transfer belt is separated from the transfer cylinder.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a transfer device and an image forming apparatus.

Background Art

[0002] Patent Document 1 describes a transfer device that transfers an image on an image carrier. The transfer device includes a transfer material conveying means for endlessly moving a transfer material along a circulating path, a gripper piece that is attached to the conveying means, pivotally supported by a rotating shaft, rotates with respect to a base member, and grips the leading edge of the transfer material, and a switch member attached to the base member. The transfer device is characterized in that the presence of the transfer material in the gripper is detected by partially notching the position of the switch member of the gripper piece.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a transfer device that can prevent the transfer belt from being dragged by the rotation of the transfer cylinder except during image formation in a configuration where the transfer cylinder rotates in conjunction with the fixing roll.

Means for Solving the Problems

[0005] The transfer device according to the first aspect includes a transfer cylinder that rotates in conjunction with a fixing roll, a transfer belt that transfers an image to a medium while rotating with the transfer cylinder with the medium sandwiched between the transfer cylinder and the transfer belt, a pressing member disposed inside the transfer belt, and a switching means for moving the pressing member to switch between a pressing state in which the transfer belt is pressed against the transfer cylinder and a separated state in which the transfer belt is separated from the transfer cylinder.

[0006] The transfer device according to the second aspect is the transfer device described in the first aspect, wherein the switching means switches to a first separation state and a second separation state as the separation state, in which the transfer belt is more separated from the transfer cylinder than in the first separation state.

[0007] The transfer device according to the third aspect is the transfer device described in the second aspect, wherein the switching means makes the pressing member non-contact with the transfer belt in the second separation state.

[0008] The transfer device according to the fourth aspect is the transfer device described in any one of the first to third aspects, wherein the pressing member extends in the width direction of the transfer belt and has a configuration of being rotated together with the transfer belt, and the switching means has an adjusting means for adjusting the posture of the pressing member in the pressing state.

[0009] The transfer device according to the fifth aspect is the transfer device described in the fourth aspect, wherein the switching means includes a cam portion provided at both ends of the pressing member and a driving means for driving the cam portion, and the adjusting means includes the cam portion and a control portion for controlling the driving amount of the cam portion by the driving means.

[0010] The image forming apparatus according to the sixth aspect includes the transfer device described in any one of the first to fifth aspects, a fixing device having the fixing roll for fixing the image transferred to the medium on the medium, an interlocking means for rotating the transfer cylinder in interlock with the fixing roll, and a control device for making the switching means in the separation state during the warm-up operation of the fixing device.

[0011] The image forming apparatus according to the seventh aspect is the image forming apparatus according to claim 6, wherein the transfer device is the transfer device described in claim 2 or claim 3 or claim 4 or claim 5 that cites claim 2 or claim 3, and the control device makes the switching means in the first separation state during the warm-up operation of the fixing device.

[0012] The image forming apparatus according to the eighth aspect, wherein the transfer device is the transfer device according to claim 2 or claim 3 or claim 4 or claim 5 that cites claim 2 or claim 3, and the control device is the image forming apparatus according to claim 6 or claim 7 that causes the switching means to be in the second separated state during maintenance of the transfer device.

Effect of the Invention

[0013] The transfer device according to the first aspect can prevent the transfer belt from being rotated along with the rotation of the transfer cylinder except during image formation.

[0014] The transfer device according to the second aspect can transfer an image to a medium promptly from the first separated state as compared with a configuration in which the switching means can only take the second separated state as a separated state.

[0015] The transfer device according to the third aspect suppresses deterioration of the pressing member as compared with a configuration in which the pressing member is in contact with the transfer belt in the second separated state.

[0016] The transfer device according to the fourth aspect can correct the posture of the transfer belt in the pressed state.

[0017] The transfer device according to the fifth aspect can simplify the adjustment means as compared with a configuration in which the cam portion of the adjustment means is separate from the cam portion of the contact-separation mechanism 180.

[0018] The image forming apparatus according to the sixth aspect can prevent deterioration of the transfer belt during warm-up operation.

[0019] The image forming apparatus according to the seventh aspect can transfer an image to a medium promptly from the warm-up operation as compared with a configuration in which the switching means can only take the second separated state as a separated state during the warm-up operation of the fixing device.

[0020] The image forming apparatus according to the eighth aspect can improve the workability of maintenance of the transfer device as compared with a configuration in which the switching means can only take the first separated state as a separated state during maintenance of the transfer device.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0022] An example of a transfer device and an image forming apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to 9. In the figures, the arrow H indicates the vertical direction (up and down direction) of the apparatus, the arrow W indicates the width direction (horizontal direction) of the apparatus, and the arrow D indicates the depth direction (horizontal direction) of the apparatus.

[0023] (Image Forming Apparatus 10) The image forming apparatus 10 according to the present embodiment is an inkjet type image forming apparatus that forms an ink image on a sheet member P based on image information input to the image forming apparatus 10. The sheet member P is an example of a medium. The ink image is an example of an image. As shown in FIG. 8, the image forming apparatus 10 includes a housing portion 50, a paper feeding mechanism 48, a chain gripper 66, a transfer device 30, an image forming portion 12, a fixing device 100, a cooling portion 90, a paper discharging mechanism 56, and a discharging portion 52. Further, the image forming apparatus 10 further includes a control device 110 that outputs control information based on the image information input to the image forming apparatus 10, detection results of sensors, etc., and controls the operations of each part.

[0024] 〔Housing portion 50〕 The housing portion 50 has a function of housing the sheet member P.

[0025] 〔Paper feeding mechanism 48〕 The paper feeding mechanism 48 has a function of conveying the sheet member P housed in the housing portion 50 to a chain gripper 66 described later.

[0026] Specifically, as shown in FIG. 8, the paper feeding mechanism 48 includes a delivery roll 62 and a plurality of conveying rolls 64 that convey the sheet member P along a paper feeding path 40 through which the sheet member P is conveyed.

[0027] The delivery roll 62 is a roll that sends out the sheet member P housed in the housing portion 50 to the paper feeding path 40. The plurality of conveying rolls 64 are rolls that convey the sheet member P sent out to the paper feeding path 40 by the delivery roll 62 to the chain gripper 66 described later.

[0028] 〔Chain gripper 66〕 The chain gripper 66 has a function of conveying the sheet member P conveyed from the paper feeding mechanism 48 to the paper discharge path 42 via a transfer device 30 and a fixing device 100, which will be described later. The chain gripper 66 is an example of a conveying unit. As shown in FIG. 1, the chain gripper 66 includes a pair of chains 72, sprockets 71, 73, 92, 94, 96, and a gripping unit 68 (see FIG. 5) having a gripping member 76 for gripping the leading end of the sheet member P.

[0029] As shown in FIG. 5, the pair of chains 72 are arranged to be spaced apart in the depth direction of the apparatus, and the chains 72 are formed in an endless shape (see FIG. 1). Then, as shown in FIG. 7, the pair of chains 72 are arranged on one axial end side and the other axial end side of an opposed roll 36, which will be described later, and are wound around a pair of sprockets 73 having the axial direction in the depth direction of the apparatus. Further, as shown in FIG. 6, the pair of chains 72 are arranged on one axial end side and the other axial end side of a pressure roll 140, which will be described later, and are wound around a pair of sprockets 71 having the axial direction in the depth direction of the apparatus. Furthermore, as shown in FIG. 1, the pair of chains 72 are wound around a pair of sprockets 92, a pair of sprockets 94, and a pair of sprockets 96, which are arranged at intervals in the depth direction of the apparatus.

[0030] In this configuration, when rotational force is transmitted to any one of the plurality of sprockets 71, 73, 92, 94, 96, the pair of chains 72 circulates in the direction of arrow C in the figure so as to move from the sprocket 73 side to the sprocket 71 side. In the present embodiment, the rotational force of the pressure roll 140 is transmitted to the sprocket 71. When the sprocket 71 rotates by the pressure roll 140, the pair of chains 72 wound around the sprockets 71 and 73 rotates the opposing roll 36 on which the sprocket 73 is disposed in conjunction with the rotation of the sprocket 71 of the pressure roll 140. The chain gripper 66 including the sprockets 71 and 73 and the pair of chains 72 is an example of an interlocking means. In this configuration, the chain gripper 66 conveys the sheet member P gripped by the gripping unit 68 along the circumferential direction of the pair of chains 72.

[0031] A plurality of gripping units 68 are provided and arranged at predetermined intervals along the circumferential direction (circulation direction) of the chain 72. Further, as shown in FIG. 5, the gripping unit 68 extends in the depth direction of the apparatus, and both portions on both sides in the depth direction of the apparatus of the gripping unit 68 are respectively attached to the pair of chains 72. The gripping unit 68 moves along the circumferential direction of the chain 72 as the chain 72 circulates.

[0032] As shown in FIG. 5, the gripping unit 68 includes a plate portion 80 extending in the depth direction of the apparatus, a pair of support plates 82 supporting the plate portion 80, and shaft members 84 extending in the depth direction of the apparatus and having ends respectively attached to the chain 72. Further, the gripping unit 68 includes a gripping member 76 that grips the tip of the sheet member P between the plate portion 80.

[0033] The plate portion 80 is made of stainless steel and is disposed between the pair of chains 72. Further, when viewed from the depth direction of the apparatus, the upstream portion in the sheet conveyance direction of the plate portion 80 is inclined with respect to the sheet conveyance direction so as to approach the sheet member P with respect to the downstream portion.

[0034] The support plate 82 is made of stainless steel and is respectively arranged at both ends of the plate portion 80 with the plate thickness direction as the depth direction of the device. And both ends of the plate portion 80 are respectively attached to a pair of support plates 82, and the pair of support plates 82 support the plate portion 80. Further, a circular through-hole 82a is formed in the support plate 82.

[0035] The shaft member 84 is made of stainless steel, extends in the depth direction of the device, and is arranged on the downstream side in the sheet conveying direction with respect to the plate portion 80. Further, the shaft member 84 respectively passes through the through-holes 82a formed in the support plate 82. And both ends of the shaft member 84 are respectively attached to a pair of chains 72.

[0036] A plurality of gripping members 76 are provided and are attached to the shaft member 84 at predetermined intervals along the depth direction of the device. The gripping member 76 includes a main body portion 86 in which a through-hole 86a through which the shaft member 84 passes is formed, and a contact portion 88 that contacts the sheet member P.

[0037] The main body portion 86 is made of aluminum. When viewed from the depth direction of the device, the downstream portion of the main body portion 86 in the sheet conveying direction is arc-shaped. Further, on the upstream side of the main body portion 86 in the sheet conveying direction and on the outer side of the endless chain 72 (the side opposite to the side surrounded by the endless chain 72 when viewed from the depth direction of the device), a protruding portion 86b protruding toward the plate portion 80 is formed. Also, the protruding portion 86b is rectangular when viewed from the protruding direction.

[0038] The contact portion 88 is a stainless steel plate member and is attached to the surface of the protruding portion 86b facing the outer side of the endless chain 72. And the contact portion 88 extends from the protruding portion 86b toward the plate portion 80 and is adapted to contact the plate portion 80 from the outer side of the endless chain 72.

[0039] In this configuration, the shaft member 84 is rotated by a cam mechanism (not shown), and the contact portion 88 is pressed against the plate portion 80 from the outside of the endless chain 72 to contact the plate portion 80, and the contact portion 88 is separated from the plate portion 80. In this way, the tip of the sheet member P is gripped by the gripping member 76 and the gripping is released.

[0040] 〔Transfer device 30〕 The transfer device 30 has a function of superimposing the ink discharged from the printing heads 20 of each color described later on the intermediate transfer body on which the ink-receptive particle layer 16A is formed to form an ink image, and transferring the ink image to the sheet member P. As shown in FIG. 1, the transfer device 30 includes a transfer belt 31 as an intermediate transfer body, a plurality of rolls 32, a transfer roll 34, and an opposing roll 36. Further, the transfer device 30 includes an adhesive layer forming device 24, a particle supply device 18, a cleaner 28, and a contact / separation mechanism 180.

[0041] As shown in FIG. 1, the transfer belt 31 is endless and is wound around and stretched over a plurality of rolls 32 and the transfer roll 34 so as to have an inverted triangular posture when viewed from the front (viewed from the front side in the depth direction of the apparatus). The transfer belt 31 circulates in the direction of arrow B when at least one of the plurality of rolls 32 is rotationally driven. The printing heads 20 of each color, the particle supply device 18, the adhesive layer forming device 24, and the cleaner 28 are arranged on the outer peripheral portion of the transfer belt 31. Further, the transfer belt 31 is provided with an attitude sensor (not shown) that detects the attitude state of the transfer belt 31 and transmits the detection result to the control device 110.

[0042] The transfer roll 34 is disposed inside the transfer belt 31. The transfer roll 34 is supported so that it can be brought into a pressing state in which the transfer belt 31 is pressed against the opposing roll 36 (details will be described later) by pushing out the inclined portion on one side (the left side in the figure) in the apparatus width direction of the transfer belt 31 by the contact / separation mechanism 180 described later. The transfer roll 34 is an example of a pressing member. Also, the opposing roll 36 is an example of a transfer cylinder.

[0043] The opposing roll 36 is disposed on the opposite side of the transfer roll 34 with the transfer belt 31 interposed therebetween. And, as shown in FIG. 7, the opposing roll 36 extends in the depth direction of the apparatus.

[0044] The opposing roll 36 is a cylindrical member made of aluminum, and has a roll portion 174 whose outer circumferential surface in the circumferential direction is coated with a resin material such as silicone rubber or PFA, and a pair of shaft portions 176 respectively protruding in the depth direction of the apparatus from both end portions of the roll portion 174. The sprocket 73 described above is respectively attached to the pair of shaft portions 176.

[0045] The opposing roll 36 is driven to rotate following the circulation of the chain 72 of the chain gripper 66 by the sprocket 73, and rotates along the circulation direction C of the chain 72.

[0046] A recess 178 capable of accommodating the gripping member 76 therein is formed in the roll portion 174 of the opposing roll 36. This recess 178 has a groove-like shape extending in the depth direction of the apparatus from one end to the other end of the roll portion 174.

[0047] The opposing roll 36 incorporates a heat source (not shown) and has a configuration capable of heating the outer peripheral portion.

[0048] The opposing roll 36 forms a nip portion NT between the transfer roll 34 that presses out the transfer belt 31 and presses it against the opposing roll 36. In other words, the nip portion NT is formed between the opposing roll 36 and the transfer belt 31. The opposing roll 36 that rotates following the circulation of the chain 72 drives the transfer belt 31 around at the nip portion NT. The opposing roll 36 transfers the ink image formed on the transfer belt 31 to the sheet member P while driving the transfer belt 31 around with the heated outer peripheral portion and the transfer belt 31 sandwiching the sheet member P conveyed by the chain gripper 66 at the nip portion NT.

[0049] As shown in Fig. 1, the adhesive layer forming device 24 is disposed at the end on one side (the left side in the figure) in the device width direction of the horizontal portion of the transfer belt 31 in an inverted triangular posture. The adhesive layer forming device 24 contains an adhesive inside, and forms an adhesive layer (not shown) by applying the adhesive to the outer peripheral surface of the circulating transfer belt 31. For the adhesive, for example, glue, organic solvent, etc. can be used.

[0050] The particle supply device 18 is disposed on the horizontal portion of the transfer belt 31, on the downstream side in the circumferential direction of the transfer belt 31 with respect to the adhesive layer forming device 24. The particle supply device 18 contains ink-receptive particles 16 capable of receiving ink droplets inside, and supplies the ink-receptive particles 16 to the transfer belt 31 on which the adhesive layer is formed. As a result, the ink-receptive particles 16 supplied to the transfer belt 31 by the particle supply device 18 adhere to the adhesive layer by the adhesive force of the adhesive layer, and an ink-receptive particle layer 16A is formed on the transfer belt 31.

[0051] The ink-receptive particle layer 16A formed on the transfer belt 31 contacts the sheet member P sandwiched between the transfer belt 31 and the counter roll 36 at the nip portion NT and is heated by the counter roll 36, and thus is transferred to the sheet member P. At this time, if an ink image is formed on the ink-receptive particle layer 16A because the ink-receptive particle layer 16A is receiving ink droplets, the ink image is transferred to the sheet member P together with the ink-receptive particle layer 16A.

[0052] The cleaner 28 is disposed on the downstream side in the circumferential direction of the transfer belt 31 with respect to the nip portion NT and on the upstream side in the circumferential direction with respect to the adhesive layer forming device 24. The cleaner 28 includes a blade 28a that is in contact with the outer peripheral surface of the transfer belt 31. The cleaner 28 has a configuration in which, as the transfer belt 31 circulates, the adhesive layer, the ink-receptive particles 16, and other foreign matters (for example, paper dust, etc. when the sheet member P is paper) remaining on the portion of the transfer belt 31 that has passed through the nip portion NT are removed by the blade 28a.

[0053] Details of the transfer roll 34 and the contact / separation mechanism 180 will be described later.

[0054] 〔Image forming unit 12〕 The image forming unit 12 has a function of forming an image to be transferred onto the sheet member P by an inkjet method. As shown in FIG. 8, the image forming unit 12 is arranged on the other side (the right side in the figure) in the apparatus width direction with respect to the paper feeding mechanism 48. The image forming unit 12 includes a plurality of print heads 20 for forming an ink image.

[0055] A plurality of print heads 20 are provided so as to form an ink image for each color. In the present embodiment, a total of four-color print heads 20 for yellow (Y), magenta (M), cyan (C), and black (K) are provided. (Y), (M), (C), and (K) shown in FIGS. 1 and 8 indicate the components corresponding to the respective colors.

[0056] The print heads 20Y, 20M, 20C, and 20K are basically the same in configuration except for the ink used. As shown in FIG. 1, the print heads 20Y, 20M, 20C, and 20K are arranged side by side along the horizontal portion of the transfer belt 31 on the downstream side in the circumferential direction of the transfer belt 31 from the particle supply device 18 in the horizontal portion of the transfer belt 31.

[0057] The print heads 20Y, 20M, 20C, and 20K discharge and superimpose ink droplets of respective colors of Y, M, C, and K on the transfer belt 31 on which the ink-receptive particle layer 16A is formed, based on the image information input to the image forming apparatus 10. The ink droplets discharged from the print heads 20Y, 20M, 20C, and 20K are received by the ink-receptive particle layer 16A to form an ink image. That is, the image forming unit 12 forms an image on the transfer belt 31.

[0058] 〔Fixing device 100〕 The fixing device 100 has a function of fixing the ink image transferred onto the sheet member P by the transfer device 30 to the sheet member P.

[0059] As shown in Fig. 1, the fixing device 100 includes a preheating unit 102 that preheats the sheet member P conveyed by the chain gripper 66, a main heating unit 120 that heats the sheet member P, and a blowing unit 170 that blows air onto the sheet member P.

[0060] -Preheating Unit 102- As shown in Fig. 1, the preheating unit 102 is arranged on the downstream side of the nip portion NT in the conveying direction of the sheet member P (hereinafter referred to as the "sheet conveying direction") so as to face the upper surface side of the conveyed sheet member P. This preheating unit 102 includes a reflecting member 104, a plurality of infrared heaters 106 (hereinafter referred to as "heaters 106"), and a wire mesh 112.

[0061] In this configuration, the preheating unit 102 non - contact heats the sheet member P conveyed by the circulating chain 72 from the thickness direction of the sheet member P.

[0062] -Blowing Unit 170- As shown in Fig. 1, the blowing unit 170 is arranged so as to face the preheating unit 102 in the thickness direction of the conveyed sheet member P, and the conveyed sheet member P passes between the blowing unit 170 and the preheating unit 102. Further, the blowing unit 170 includes a plurality of fans 172 arranged in the width direction of the conveyed sheet member P and in the sheet conveying direction.

[0063] In this configuration, the plurality of fans 172 blow air toward the conveyed sheet member P, thereby stabilizing the conveying posture of the conveyed sheet member P.

[0064] -Main Heating Unit 120- As shown in FIG. 1, this heating unit 120 is arranged on the downstream side of the preliminary heating unit 102 in the sheet conveyance direction. As shown in FIG. 6, this heating unit 120 includes a heating roll 130 that contacts the conveyed sheet member P to heat the sheet member P, and a pressure roll 140 that sandwiches the sheet member P with the heating roll 130 and presses the sheet member P toward the heating roll 130. Further, this heating unit 120 further includes a heat source roll 150 that contacts and heats the heating roll 130 as a heat source of the heating roll 130.

[0065] Furthermore, this heating unit 120 includes a support member 156 that contacts a pair of shaft portions 148 protruding in the depth direction of the apparatus from both end portions of the pressure roll 140 to support the pressure roll 140. Also, this heating unit 120 includes a biasing member 158 that biases the pressure roll 140 toward the heating roll 130 via the support member 156. The aforementioned sprocket 71 is attached to each of the pair of shaft portions 148.

[0066] In this embodiment, the heating roll 130 is driven and rotated by a motor (not shown), and the pressure roll 140 and the heat source roll 150 are configured to be driven following the rotation of the heating roll 130. The rotational force of the heating roll 130 is transmitted to the sprocket 71 attached to the shaft portion 148 of the pressure roll 140 to circulate the chain 72 of the chain gripper 66, and is transmitted to the sprocket 73 attached to the opposing roll 36 to rotate the opposing roll 36. That is, the heating roll 130 rotates the opposing roll 36 in conjunction with the rotation of the heating roll 130. In this embodiment, the heating roll 130 is an example of a fixing roll.

[0067] Note that the present invention is not limited to a configuration in which the heating roll 130 is driven and the pressure roll 140 and the heat source roll 150 are driven following the heating roll 130. For example, a configuration in which the pressure roll 140 is driven and the heating roll 130 and the heat source roll 150 are driven following the pressure roll 140 may be used. Also, a configuration in which the heat source roll 150 is driven and the heating roll 130 and the pressure roll 140 are driven following it may be used.

[0068] In this configuration, the heating roll 130 and the pressure roll 140 sandwich and convey the sheet member P onto which the ink image has been transferred, so that the ink image is heated and fixed to the sheet member P.

[0069] 〔Cooling unit 90〕 The cooling unit 90 has a function of cooling the sheet member P heated by the fixing device 100. As shown in FIG. 8, a paper discharge path 42 is formed through which the sheet member P on which the ink image is fixed by the fixing device 100 and discharged to the outside of the apparatus main body 10a is conveyed, and the cooling unit 90 is disposed along this paper discharge path 42.

[0070] As shown in FIG. 9, the cooling unit 90 includes two rolls 90a arranged side by side in the apparatus width direction, and an endless belt 90b wound around the two rolls 90a and having an upper surface along the paper discharge path 42. Further, the cooling unit 90 includes a cooling fan 90c that blows air against the lower surface of the belt 90b to cool the belt 90b, and rolls 90d respectively disposed on the opposite sides of the two rolls 90a with the paper discharge path 42 and the belt 90b interposed therebetween.

[0071] In this configuration, one of the two rolls 90a is rotationally driven. As a result, the belt 90b cooled by the cooling fan 90c circulates in the direction of the arrow in the figure, so that the roll 90d rotates following the circulating belt 90b. Further, the circulating belt 90b and the roll 90d that rotates following it sandwich and convey the sheet member P. Thereby, the sheet member P is cooled.

[0072] 〔Paper discharge mechanism 56〕 The paper discharge mechanism 56 has a function of discharging the sheet member P cooled by the cooling unit 90 to the discharge unit 52 outside the apparatus main body 10a. As shown in FIG. 8, the paper discharge mechanism 56 is disposed on one side (the left side in the figure) in the apparatus width direction with respect to the image forming unit 12. Further, the paper discharge mechanism 56 includes a plurality of conveyance rolls 54 that convey the sheet member P along the paper discharge path 42.

[0073] (Principal component configuration) Next, the transfer roll 34 and the contact / separation mechanism 180 that constitute the transfer device 30 will be described.

[0074] 〔Transfer roll 34〕 As shown in FIG. 7, the transfer roll 34 extends in the depth direction of the apparatus and is in contact with the transfer belt 31 so as to press the transfer belt 31 against the opposing roll 36 in the pressed state. Further, the transfer roll 34 includes a shaft member 34a and a cylindrical roll portion 34b through which the shaft member 34a passes.

[0075] Both ends of the shaft member 34a are supported via bearings by the holder portions 182 (see FIG. 2) of the contact / separation mechanism 180 described later, respectively.

[0076] In this configuration, when the transfer roll 34 is in contact with the transfer belt 31, it is carried around by the circulating transfer belt 31.

[0077] 〔Contact / separation mechanism 180〕 The contact / separation mechanism 180 has a configuration that switches between a pressed state in which the transfer roll 34 is moved to press the transfer belt 31 against the opposing roll 36 and a separated state in which the transfer belt 31 is separated from the opposing roll 36. The contact / separation mechanism 180 is an example of a switching means. As described above, the contact / separation mechanism 180 is disposed at both ends of the shaft member 34a of the transfer roll 34 inside the transfer belt 31 in a front view, and the respective configurations are basically the same. As shown in FIG. 2, the contact / separation mechanism 180 includes a holder portion 182 and a cam portion 190.

[0078] The holder portion 182 includes a holder main body 182a, a bearing 184, a swing shaft 186, and a cam follower 188. As shown in FIG. 2, the holder main body 182a is a thin plate-shaped member that extends in the direction along the transfer belt 31 and expands in the apparatus height direction and the apparatus width direction. The bearing 184 is disposed at a portion of the holder main body 182a closer to the transfer belt 31, and supports the shaft member 34a of the transfer roll 34 such that a part of the roll portion 34b of the transfer roll 34 protrudes from the holder main body 182a toward the transfer belt 31 in a front view.

[0079] In the present embodiment, the swing shaft 186 is disposed at a portion in one direction (left side in the figure) in the apparatus width direction with respect to the bearing 184 of the holder main body 182a, and is supported by a frame (not shown) of the transfer apparatus 30, and swingably supports the holder main body 182a. A torsion coil spring (not shown) connected to the holder main body 182a and the frame (not shown) is provided on the swing shaft 186. This torsion coil spring biases the holder main body 182a in a direction in which the transfer roll 34 moves away from the counter roll 36 about the swing shaft 186. In the present embodiment, the holder main body 182a is configured to swing about the swing shaft 186 by the above-described torsion coil spring and a cam portion 190 described later. In the description of the present embodiment, the angle of a virtual straight line K passing through the central portions of the swing shaft 186 and the bearing 184 with respect to the apparatus vertical direction is defined as the inclination angle θ of the holder portion 182.

[0080] The holder portion 182 is configured to change the tension state of the transfer belt 31 by moving the transfer roll 34 as the holder body 182a swings. Specifically, when the inclination angle θ of the holder portion 182 is a predetermined angle θ0 (θ = θ0), the holder portion 182 is configured to bring the transfer belt 31 into a pressing state (see FIG. 2) in which the transfer belt 31 is pressed against the opposing roll 36 by the transfer roll 34. Further, as shown in FIG. 3, when the inclination angle θ of the holder portion 182 becomes a predetermined angle θ1 greater than θ0 (θ = θ1>θ0), the holder portion 182 is configured to move the transfer roll 34 to a position separated from the opposing roll 36. At this time, as the transfer roll 34 moves, the tension state of the transfer belt 31 changes, and the transfer belt 31 is in a separated state in which it is separated from the opposing roll 36. In the present embodiment, the separated state when the inclination angle θ of the holder portion 182 is θ1 (θ = θ1) is defined as the first separated state.

[0081] Further, as shown in FIG. 4, when the inclination angle θ of the holder portion 182 becomes a predetermined angle θ2 greater than θ1 (θ = θ2>θ1), the holder portion 182 is configured to move the transfer roll 34 to a position more separated from the opposing roll 36 than in the first separated state. Accordingly, the transfer belt 31 is in a state of being more separated from the opposing roll 36 than in the first separated state. In the present embodiment, the separated state when the inclination angle θ of the holder portion 182 is θ2 (θ = θ2) is defined as the second separated state.

[0082] In the present embodiment, in the second separated state, the holder portion 182 is configured to separate the transfer roll 34 from the transfer belt 31. In other words, the contact / separation mechanism 180 including the holder portion 182 is configured to bring the transfer roll 34 into non-contact with the transfer belt 31 in the second separated state.

[0083] The holder part 182 has a configuration that can appropriately transfer the image formed on the transfer belt 31 to the sheet member P at the nip part NT by moving the transfer roll 34 to press the transfer belt 31. That is, the pressed state is a state in which the transfer device 30 can appropriately transfer the image formed on the transfer belt 31 to the sheet member P. The inclination angle θ of the holder part 182 in the pressed state is not limited to a determined angle θ0, and any angle within the range that can appropriately transfer the image to the sheet member P by the transfer device 30 is acceptable.

[0084] A pair of holder parts 182 respectively arranged at both ends of the transfer roll 34 has a configuration that can change the posture of the transfer roll 34 by independently adjusting the respective inclination angles θ. Further, the transfer device 30 including the holder part 182 has a configuration to be in a pressed state if the inclination angle θ of the holder part 182 is within the range of a determined angle ±Δθ with respect to θ0 (θ0 - Δθ ≤ θ ≤ θ0 + Δθ). When the holder part 182 swings within the range of the determined angle ±Δθ with respect to θ0, the transfer roll 34 and the opposing roll 36 move following the swing of the holder part 182 while the pressed state of the transfer belt 31 is maintained.

[0085] The cam follower 188 is a cylindrical member arranged at a part of the holder main body 182a on the side opposite to the swing axis 186 with respect to the bearing 184 in the device width direction. As shown in FIGS. 2 to 4, the outer peripheral part 188a of the cam follower 188 is in contact with the cam part 190, and the holder part 182 is swung to move the transfer roll 34 according to the transition of the part of the cam part 190 in contact with the cam follower 188.

[0086] The cam portion 190 includes a cam body 190a, a rotating shaft 192, a driving portion 194, and a control portion 196. The cam body 190a is a plate member that is substantially semi-circular when viewed from the front. The cam body 190a has a structure of an eccentric cam that is rotatable about the rotating shaft 192. Further, the cam body 190a is in contact with the outer peripheral portion 188a of the cam follower 188 by the biasing force of a torsion coil spring (not shown) provided on the holder body 182a of the holder portion 182 with respect to the swing shaft 186. Furthermore, the cam body 190a has a configuration in which, as the rotating shaft 192 rotates, the phase of the cam body 190a is changed, and the position of the portion in contact with the cam follower 188 is shifted, thereby swinging the holder portion 182 and changing the inclination angle θ of the holder portion 182. The rotating shaft 192 is supported by a frame (not shown) of the transfer device 30.

[0087] The driving portion 194 includes, for example, a motor or the like connected to the rotating shaft 192 via a transmission mechanism, and changes the phase of the cam body 190a by rotationally driving the rotating shaft 192. That is, the driving portion 194 drives the cam portion 190. The driving portion 194 is provided individually for each of the contact / separation mechanisms 180. Each driving portion 194 is an example of a driving means.

[0088] The control portion 196 has a configuration for controlling the driving amount of the cam portion 190 by the driving portion 194. As shown in FIG. 2, the control portion 196 includes a phase sensor 196a and a detected portion 196b provided on the cam body 190a. The phase sensor 196a detects the phase of the cam body 190a by detecting the detected portion 196b, and transmits the detection result to the control device 110. The control portion 196 has a configuration for controlling the driving amount of each cam portion 190 by the driving portion 194 based on the detection result of the phase sensor 196a and the control information output from the control device 110 based on the detection result of the attitude sensor of the transfer belt 31 described above.

[0089] The control unit 196 has a configuration capable of adjusting the phases of the pair of cam bodies 190a independently by adjusting the driving amount of each cam unit 190 by the driving unit 194. When the control unit 196 makes the phases of the respective cam bodies 190a different, the inclination angles θ of the respective holder units 182 become different accordingly, and the posture of the transfer roll 34 supported by each holder unit 182 inclines with respect to the depth direction of the apparatus. That is, the control unit 196 has a configuration capable of adjusting the posture of the transfer roll 34 by adjusting the driving amount of each cam unit 190 by the driving unit 194. The combination of the cam unit 190 and the control unit 196 is an example of an adjustment means.

[0090] (Operation of the contact / separation mechanism 180) The contact / separation mechanism 180 has a configuration in which its operation is controlled by the control device 110 based on the state of the image forming apparatus 10, and is switched between a pressed state, a first separated state, and a second separated state. The operation of the contact / separation mechanism 180 based on the state of the image forming apparatus 10 will be described below.

[0091] When the image forming apparatus 10 is in a non-operating state where power is not supplied, the transfer belt 31 is in the second separated state. Also, at this time, power is not supplied to the fixing device 100, and the heating roll 130 is in a non-heated state.

[0092] When power is supplied to the image forming apparatus 10 in the non-operating state, the image forming apparatus 10 enters the operating state. When image information to be formed on the sheet member P is input to the operating image forming apparatus 10, the control device 110 supplies power to the fixing device 100 to perform a warm-up operation. Specifically, in the warm-up operation, the control device 110 heats the heating roll 130 with the heat source roll 150 until the heating roll 130 reaches a fixing temperature suitable for fixing an image on the sheet member P from the non-heated state. At this time, the control device 110 rotates the heating roll 130 with a motor (not shown) in a state where the heating roll 130 is in contact with the heat source roll 150 so that the entire outer peripheral portion of the heating roll 130 reaches the fixing temperature. When the heating roll 130 rotates, the opposing roll 36 rotates in conjunction with the rotation of the heating roll 130 by the chain gripper 66. Also, at this time, as shown in FIG. 3, the control device 110 controls the contact and separation mechanism 180 to place the transfer belt 31 in the first separated state.

[0093] When the entire outer peripheral portion of the heating roll 130 reaches the fixing temperature, the control device 110 controls the contact and separation mechanism 180 to place the transfer belt 31 in the pressed state, as shown in FIG. 2. Also, the control device 110 controls the operations of each part to convey the sheet member P in the storage unit 50 by the paper feeding mechanism 48 and the chain gripper 66, and to form an image on the transfer belt 31 by the image forming unit 12. The conveyed sheet member P has the image formed on the transfer belt 31 transferred at the nip portion NT, the image is fixed by the fixing device 100, cooled by the cooling unit 90, and discharged to the discharge unit 52 by the paper discharge mechanism 56.

[0094] When a state in which image information to be formed on the sheet member P is not input is maintained for a predetermined time or longer in the operating image forming apparatus 10, the control device 110 shifts the image forming apparatus 10 to a power saving state. Specifically, in the power saving state, as shown in FIG. 3, the control device 110 controls the contact and separation mechanism 180 to place the transfer belt 31 in the first separated state and cuts off the power supply to each part other than the fixing device 100. Further, in the power saving state, the control device 110 controls the fixing device 100 so that the entire outer peripheral portion of the heating roll 130 reaches a predetermined temperature lower than the fixing temperature, and rotates the heating roll 130 at a rotational speed lower than that during the warm-up operation by a motor (not shown). At this time, the opposing roll 36 rotates at a rotational speed lower than that during the warm-up operation in conjunction with the rotation of the heating roll 130.

[0095] When an operation to shift the image forming apparatus 10 to the non-operating state is performed on the image forming apparatus 10 in the operating state or the power saving state, the control device 110 controls the contact and separation mechanism 180 to place the transfer belt 31 in the second separated state, as shown in FIG. 4, and cuts off the power supply to each part. The operation to shift the image forming apparatus 10 to the non-operating state includes an operation to turn off the power of the image forming apparatus 10 and an operation to shift to maintenance. Maintenance of the image forming apparatus 10 includes replacement of members of the transfer belt 31 of the transfer device 30 and the like.

[0096] <Operation and Effect> Next, the operation and effect of the present embodiment will be described. In this description, when describing a comparative form with respect to the present embodiment, when using components and the like similar to those of the image forming apparatus 10 of the present embodiment, the reference numerals and names of those components and the like will be used as they are for the description.

[0097] The transfer device 30 of the image forming apparatus 10 of the present embodiment includes a contact and separation mechanism 180 that switches between a pressing state in which the transfer roll 34 is moved to press the transfer belt 31 against the opposing roll 36 and a separated state in which the transfer belt 31 is separated from the opposing roll 36. The image forming apparatus 10 of the present embodiment is compared with an image forming apparatus 210 of a comparative form shown below.

[0098] The image forming apparatus 210 of the comparative form does not include the contact and separation mechanism 180, and has a configuration in which the transfer belt 31 is always pressed against the opposing roll 36 by the transfer roll 34. Except for the above points, the image forming apparatus 210 of the comparative form has the same configuration as the image forming apparatus 10 of the present embodiment.

[0099] In the image forming apparatus 210 of the comparative form, the transfer belt 31 is always pressed against the opposing roll 36 by the transfer roll 34. Therefore, the transfer belt 31 rotates along with the opposing roll 36 that rotates in conjunction with the rotation of the heating roll 130 by the chain gripper 66 even during the warm-up operation other than during image formation. When the transfer belt 31 rotates during non-image formation, there is a risk that the deterioration of the transfer belt 31 will be accelerated because it rotates while the blade 28a of the cleaner 28 is in contact.

[0100] On the other hand, the transfer device 30 of the present embodiment includes the contact and separation mechanism 180. As a result, the transfer device 30 can separate the transfer belt 31 during non-image formation such as warm-up operation. In the separated state, since the transfer belt 31 is separated from the opposing roll 36, it does not rotate along with the rotation of the opposing roll 36. Therefore, the transfer device 30 of the present embodiment can prevent the transfer belt 31 from rotating along with the rotation of the opposing roll 36 when it is not image formation by including the contact and separation mechanism 180.

[0101] In addition, the image forming apparatus 10 including the transfer device 30 of the present embodiment can prevent deterioration of the transfer belt 31 during warm-up operation.

[0102] Further, the transfer device 30 of the present embodiment has a configuration in which the contact and separation mechanism 180 switches between a first separated state as a separated state and a second separated state in which the transfer belt 31 is more separated from the opposing roll 36 than in the first separated state. Therefore, the transfer device 30 of the present embodiment can transfer an image to the sheet member P quickly from the first separated state as compared with a configuration in which the contact and separation mechanism can only take the second separated state as the separated state.

[0103] Further, the transfer device 30 of the present embodiment has a configuration in which the contact separation mechanism 180 separates the transfer roll 34 from the transfer belt 31 in the second separated state. Therefore, the transfer device 30 of the present embodiment suppresses the deterioration of the transfer roll 34 as compared with a configuration in which the transfer roll 34 is in contact with the transfer belt 31 in the second separated state.

[0104] Further, the transfer device 30 of the present embodiment has adjustment means for adjusting the posture of the transfer roll 34, which includes a cam portion 190 and a control portion 196, configured by the contact separation mechanism 180. The effects of the transfer device 30 provided with the contact separation mechanism 180 having the adjustment means will be described below.

[0105] A transfer device having a configuration in which the transfer belt 31 is switched between a pressed state and a separated state may cause the transfer belt 31 wound around the transfer roll 34 to shift to a posture inclined with respect to the circumferential direction as the switching between the pressed state and the separated state occurs. If the transfer belt 31 rotates in a posture inclined with respect to the circumferential direction, there is a risk of skewing.

[0106] On the other hand, the transfer device 30 of the present embodiment has a configuration in which the posture of the transfer roll 34 is adjusted by the cam portion 190 and the control portion 196. Since the transfer belt 31 is wound around the transfer roll 34, the posture with respect to the circumferential direction changes depending on the posture of the transfer roll 34. Therefore, even if the transfer belt 31 shifts to a posture inclined with respect to the circumferential direction, the transfer device 30 of the present embodiment can correct the posture of the transfer belt 31 by adjusting the posture of the transfer roll 34 by the cam portion 190 and the control portion 196. That is, the transfer device 30 of the present embodiment can correct the posture of the transfer belt 31 in the pressed state by including the cam portion 190 and the control portion 196.

[0107] Further, the transfer device 30 of the present embodiment can prevent the skewing of the transfer belt 31 by correcting the posture of the transfer belt 31 by the cam portion 190 and the control portion 196 based on the detection result of the posture sensor of the transfer belt 31 in the pressed state.

[0108] In addition, the transfer device 30 of the present embodiment includes a separation mechanism 180 including cam portions 190 provided at both end portions of the transfer roll 34 and a drive unit 194. Further, the transfer device 30 of the present embodiment includes a control unit 196 that controls the driving amount of each cam portion 190 by the drive unit 194 as adjustment means for adjusting the posture of the transfer roll 34 in the pressed state. Therefore, the transfer device 30 of the present embodiment can simplify the adjustment means as compared with a configuration in which the cam portion of the adjustment means is separate from the cam portion of the separation mechanism 180.

[0109] In addition, the image forming apparatus 10 including the transfer device 30 of the present embodiment has a configuration in which the control device 110 causes the separation mechanism 180 to be in a first separated state during the warm-up operation of the fixing device 100. Therefore, the image forming apparatus 10 of the present embodiment can transfer an image to the sheet member P promptly from the warm-up operation as compared with a configuration in which the separation mechanism can only take the second separated state as the separated state during the warm-up operation of the fixing device.

[0110] In addition, the image forming apparatus 10 including the transfer device 30 of the present embodiment has a configuration in which the control device 110 causes the separation mechanism 180 to be in a second separated state during maintenance of the transfer device 30. Therefore, the image forming apparatus 10 of the present embodiment can improve the workability of maintenance of the transfer device as compared with a configuration in which the switching means can only take the first separated state as the separated state during maintenance of the transfer device.

[0111] Note that the operation of the present invention described above is not limited to an inkjet type image forming apparatus, and it similarly operates in an electrophotographic type image forming apparatus that forms an image with toner. An image forming apparatus 410, which is an example of the electrophotographic type image forming apparatus in the present invention, will be described below. As shown in FIG. 10, the image forming apparatus 410 includes an image forming unit 412 and a transfer device 430 instead of the image forming unit 12 and the transfer device 30 of the image forming apparatus 10. The transfer device 430 includes a transfer belt 431, a secondary transfer roll 434, and a counter roll 436 instead of the transfer belt 31, the transfer roll 34, and the counter roll 36. The secondary transfer roll 434 is an example of a pressing portion. The counter roll 436 is an example of a transfer cylinder. Further, the transfer device 430 includes a primary transfer roll 433 around which the transfer belt 431 is wound and which corresponds to each color of the image. The image forming unit 412 includes a plurality of toner image forming units 420Y, 420M, 420C, and 420K that form toner images instead of the print head 20 of the image forming apparatus 10. Each toner image forming unit 420 of each color includes a photosensitive drum 421 of each color disposed on the opposite side of each primary transfer roll 433 with the transfer belt 431 interposed therebetween. The toner image forming unit 420 forms a toner image on the photosensitive drum 421 of each color and transfers the toner image to the transfer belt 431 at a primary transfer position T formed between the photosensitive drum 421 and the primary transfer roll 433. The toner image transferred to the transfer belt 431 is transferred to the sheet member P at a nip portion NT formed between the secondary transfer roll 434 and the counter roll 436. Except for the above points, the electrophotographic type image forming apparatus 410 has the same configuration as the inkjet type image forming apparatus 10. That is, the transfer device 430 of the image forming apparatus 410 includes a contact / separation mechanism 180 in the same manner as the transfer device 30 of the image forming apparatus 10. The contact / separation mechanism 180 switches between a pressing state in which the secondary transfer roll 434 is moved in the image forming apparatus 410 and the transfer belt 431 is pressed against the counter roll 436, and a separation state in which the transfer belt 431 is separated from the counter roll 436.

[0112] As described above, specific embodiments of the present invention have been described in detail. However, the present invention is not limited to the above embodiments, and various modifications, changes, and improvements are possible within the scope of the technical idea of the present invention.

[0113] For example, in the above embodiment, the contact-and-separation mechanism 180, which is an example of the switching means, is configured to switch between a pressing state, a first separation state, and a second separation state. However, the switching means in the present invention may be configured to switch between a pressing state and one separation state.

[0114] Also, in the above embodiment, in the second separation state, the transfer roll 34 is configured to be non-contact with the transfer belt 31. However, in the present invention, the transfer roll 34 may be in contact with the transfer belt 31 in the second separation state.

[0115] Also, in the above embodiment, the contact-and-separation mechanism 180 is configured to include an adjustment means for adjusting the posture of the transfer roll 34 in the pressing state. However, in the present invention, the contact-and-separation mechanism 180 may be configured not to have the adjustment means.

[0116] Also, in the above embodiment, the adjustment means is configured to include a control unit 196 that controls the driving amount of each cam unit 190 by the driving unit 194. However, in the present invention, the adjustment means may be configured to adjust the posture of the transfer roll 34 by a cam mechanism separate from the cam unit 190 of the contact-and-separation mechanism 180.

[0117] Also, in the above embodiment, the contact-and-separation mechanism 180, which is an example of the switching means, is configured to move the transfer roll 34 by the swing of the holder unit 182 having the swing shaft 186. However, the switching means in the present invention is not limited to those having a swing shaft. For example, the switching means may be configured to move the transfer roll 34 by a translational actuator.

[0118] In the above-described embodiment, the inclination angle θ of the holder portion 182 is changed by the cam portion 190 having an eccentric cam structure. However, in the present invention, the means for changing the inclination angle θ of the holder portion 182 is not limited to those having an eccentric cam structure. For example, the holder portion 182 may be configured such that the inclination angle θ of the holder portion 182 is changed by a linear actuator.

[0119] In the above-described embodiment, the transfer belt 31 is in the first separation state in the image forming apparatus 10 during warm-up operation or in a power saving state. However, in the present invention, the transfer belt 31 may be in the second separation state in the image forming apparatus 10 during warm-up operation or in a power saving state.

[0120] In the above-described embodiment, the transfer belt 31 is in the second separation state in the non-operating image forming apparatus 10. However, in the present invention, the transfer belt 31 may be in the first separation state in the non-operating image forming apparatus 10.

[0121] In the above-described embodiment, the transfer roll 34 and the secondary transfer roll 434 are taken as an example of the pressing portion. However, the pressing portion in the present invention is not limited to being composed only of a roll-shaped member as long as it can press the transfer belt against the transfer cylinder in the pressed state. In the present invention, the pressing portion may be such that the transfer roll 34 or the secondary transfer roll 434 is incorporated integrally with another functional member. Examples of the other functional member include applying means for applying a voltage or current to the secondary transfer roll 434. Further, the combination of the transfer roll 34 and the holder main body 182a may be regarded as the pressing portion.

Explanation of Reference Numerals

[0122] 10 Image forming apparatus 30 Transfer apparatus 31 Transfer belt 34 Transfer roll (an example of the pressing portion) 36 Opposing roll (an example of the transfer cylinder) 66 Chain gripper (an example of interlocking means) 100 Fixing device 110 Control device 180 Contact-separation mechanism (an example of switching means) 190 Cam part (a part of adjustment means) 194 Driving part (an example of driving means) 196 Control part (a part of adjustment means) 410 Image forming apparatus 430 Transfer device 431 Transfer belt 434 Secondary transfer roll (an example of pressing part) 436 Opposing roll (an example of transfer cylinder) P Sheet member (an example of medium)

Claims

1. A transfer cylinder that rotates in conjunction with a fixing roll, A transfer belt that transfers an image to the medium while rotating with the transfer cylinder with the medium sandwiched between the transfer cylinder and the transfer belt, A pressing member disposed inside the transfer belt, A switching means for moving the pressing member to switch between a pressing state in which the transfer belt is pressed against the transfer cylinder and a separated state in which the transfer belt is separated from the transfer cylinder, Comprising, The pressing member extends in the width direction of the transfer belt and has a configuration that rotates with the transfer belt, The switching means has an adjusting means for adjusting the posture of the pressing member in the pressing state, a transfer device.

2. The switching means switches to a first separated state and a second separated state in which the transfer belt is more separated from the transfer cylinder than the first separated state as the separated state, the transfer device according to claim 1.

3. The switching means makes the pressing member non-contact with the transfer belt in the second separated state, the transfer device according to claim 2.

4. The switching means includes a cam portion provided at both ends of the pressing member and a driving means for driving the cam portion, The adjusting means includes the cam portion and a control portion for controlling the driving amount of the cam portion by the driving means, the transfer device according to claim 1.

5. A transfer cylinder that rotates in conjunction with a fixing roll, A transfer belt that transfers an image to the medium while rotating with the transfer cylinder with the medium sandwiched between the transfer cylinder and the transfer belt, A pressing member disposed inside the transfer belt, A switching means for moving the pressing member to switch between a pressing state in which the transfer belt is pressed against the transfer cylinder and a separated state in which the transfer belt is separated from the transfer cylinder, Comprising a transfer device, Having the fixing roll, a fixing device for fixing the image transferred to the medium to the medium, An interlocking means for rotating the transfer cylinder in conjunction with the fixing roll, A control device for causing the switching means to be in the separated state during the warm-up operation of the fixing device, An image forming apparatus comprising.

6. The transfer device according to any one of claims 1 to 4, Having the fixing roll, a fixing device for fixing the image transferred to the medium to the medium, An interlocking means for rotating the transfer cylinder in conjunction with the fixing roll, A control device for causing the switching means to be in the separated state during the warm-up operation of the fixing device, An image forming apparatus comprising...

7. The transfer device according to claim 2 or claim 3, A fixing device having the fixing roll for fixing the image transferred to the medium onto the medium, Linkage means for rotating the transfer cylinder in linkage with the fixing roll, A control device for causing the switching means to be in the separated state during the warm-up operation of the fixing device, Comprising, The control device causes the switching means to be in the first separated state during the warm-up operation of the fixing device. An image forming apparatus.

8. The image forming apparatus according to claim 7, wherein the control device causes the switching means to be in the second separated state during maintenance of the transfer device.

Images