Image forming apparatus

Abstract

To suppress a reduction in print quality in printing to media having various thicknesses and shapes compared with a case where a medium is directly placed on and conveyed by conveying means such as a conveying belt.SOLUTION: An image forming apparatus comprises: a transfer unit 100 that is brought into contact with a medium 500 to transfer an image to the medium 500; an attachment table to which the medium 500 is attached, has a spring 424 interposed between a pedestal part 422 and a leg part 421, and changes its height according to a force at which the transfer unit 100 is in contact with the medium 500; and a conveying mechanism that conveys the attachment table to which the medium 500 is attached along a conveyance path.SELECTED DRAWING: Figure 6

Description

Technical Field

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

Background Art

[0002] In recent years, there has been a case of printing an image on an object such as a medium having various thicknesses and shapes, such as metal, glass, and tile.

[0003] Patent Document 1 discloses a printing apparatus that places a disk on a conveyance table and forms an image on the disk while conveying the conveyance table together with the disk.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When forming an image by a method of transferring an image by bringing a transfer means into contact with a medium having various thicknesses and shapes, there is a possibility that the print quality may deteriorate due to displacement of the medium caused by the impact when the transfer means contacts the medium.

[0006] An object of the present invention is to suppress a decrease in print quality in printing on a medium having various thicknesses and shapes as compared with a configuration in which the medium is directly placed on a conveying means such as a conveying belt and conveyed.

Means for Solving the Problems

[0007] The present invention according to claim 1 includes a transfer unit that contacts an object and transfers an image to the object, a mounting base to which the object is attached and whose height changes according to the force with which the transfer unit contacts the object, and a conveying unit that conveys the mounting base to which the object is attached along a conveyance path.The mounting base changes its height while tilting in accordance with the force applied when the transfer portion comes into contact with the object. This is an image forming apparatus characterized by the following features. The present invention according to claim 2 is an image forming apparatus according to claim 1, characterized in that the mounting base fixes the object at least in the direction of transport by the transport unit. The present invention according to claim 3 is an image forming apparatus according to claim 2, further comprising a jig for holding down at least a portion of the object other than the surface on which the image is transferred, and the mounting base comprising a fastener for positioning and fixing the jig. The present invention according to claim 4 is an image forming apparatus according to claim 3, characterized in that the jig holds the object from at least in front of the object in the direction of transport by the transport unit, and the transfer unit contacts the jig before starting the transfer of the image, and then contacts the object to start the transfer of the image. The present invention according to claim 5 is an image forming apparatus according to claim 4, characterized in that the portion of the jig located in front of the object in the transport direction is inclined to become lower toward the front in the transport direction. Claim 6 The present invention relating to the present invention is characterized in that the mounting base comprises a movable body portion that moves along the transport path by the transport portion and a base portion on which the object is placed, and the base portion is independently supported at multiple points by elastic bodies relative to the movable body portion. 1 This is the image forming apparatus described in [reference]. Claim 7 The present invention relating to this claim is characterized in that the mounting base comprises a movable body portion that moves along the transport path by the transport portion, a base portion on which the object is placed, and a plate-shaped elastic member sandwiched between the base portion and the movable body portion. 1 This is the image forming apparatus described in [reference]. [Effects of the Invention]

[0008] According to the invention of claim 1, compared to a configuration in which a medium is placed on a transport means and transported, it is possible to suppress the deterioration of print quality caused by the displacement of the object due to impact. According to the invention of claim 2, compared to a configuration in which a medium is placed on a transport means and transported, it is possible to suppress displacement of the object due to contact with the transfer part during transport of the object. According to the invention of claim 3, compared to a configuration in which an object is attached to a mounting base without using a jig, using a jig appropriate to the object makes it easier to attach objects of various shapes and sizes to the mounting base. According to the invention of claim 4, compared to a configuration in which the transfer portion contacts the object without contacting the jig, the impact when the transfer portion contacts the object can be reduced. According to the invention of claim 5, compared to a configuration in which the jig is not inclined, the impact when the transfer part comes into contact with the jig can be reduced. Claim 6 According to this invention, by independently supporting elastic bodies at multiple locations, each elastic body sinks individually, enabling vertical movement accompanied by inclination. Claim 7 According to this invention, by sandwiching a plate-shaped elastic body, vertical movement accompanied by inclination becomes possible depending on the contact point between the object and the transfer part. [Brief explanation of the drawing]

[0009] [Figure 1] This diagram shows the configuration of an image forming apparatus to which this embodiment is applied. [Figure 2] This diagram shows the configuration of the transfer section. [Figure 3] These diagrams show the operation of the transport mechanism before image formation by the transfer unit begins. Figure 3(A) shows the height control process, Figure 3(B) shows the mechanism retracting to the preparation position after height control, and Figure 3(C) shows the state when image transfer by the transfer unit begins. [Figure 4] This diagram shows the configuration and operation of the fixing unit. Figure 4(A) shows the fixing unit with the opening closed, and Figure 4(B) shows the fixing unit with the opening open. [Figure 5] This diagram shows the structure of the mounting base; Figure 5(A) shows the first configuration example, and Figure 5(B) shows the second configuration example. [Figure 6]A diagram showing the change in the height of the mounting base during transfer. Fig. 6(A) shows the state at the start of transfer, Fig. 6(B) shows the state during transfer, and Fig. 6(C) shows the state at the end of transfer. [Figure 7] A diagram showing the first configuration example of the jig. Fig. 7(A) is a side view and Fig. 7(B) is a plan view. [Figure 8] A diagram showing the state where the jig and the medium contact the intermediate transfer belt of the transfer unit at the start of transfer. Fig. 8(A) shows the state where the jig contacts the intermediate transfer belt, and Fig. 8(B) shows the state where the medium contacts the intermediate transfer belt. [Figure 9] A diagram showing the second configuration example of the jig. Fig. 9(A) is a side view and Fig. 9(B) is a plan view. [Figure 10] A diagram showing the third configuration example of the jig. Fig. 10(A) is a side view and Fig. 10(B) is a plan view. [Figure 11] A diagram showing the fourth configuration example of the jig. Fig. 11(A) is a side view and Fig. 11(B) is a plan view. [Figure 12] A diagram showing the state where the jig and the medium contact the intermediate transfer belt of the transfer unit when using the jig according to the fourth configuration example. Fig. 12(A) shows the state where the jig contacts the intermediate transfer belt, and Fig. 12(B) shows the state where the medium contacts the intermediate transfer belt. [Figure 13] A diagram showing an example of a fastener for attaching the jig to the pedestal portion of the mounting base. Fig. 13(A) is a side view and Fig. 13(B) is a plan view. [Figure 14] A diagram showing another example of a fastener for attaching the jig to the pedestal portion of the mounting base. Fig. 14(A) is a side view and Fig. 14(B) is a plan view. [Figure 15] A diagram showing another example of a fastener for attaching the jig to the pedestal portion of the mounting base. Fig. 15(A) is a side view and Fig. 15(B) is a plan view.

Embodiments for Carrying Out the Invention

[0010] Embodiments of the present invention will be described in detail below with reference to the attached drawings. The image forming apparatus of this embodiment is an image forming apparatus that uses digital printing. Digital printing methods include electrophotography and inkjet, but in this embodiment, the electrophotography method is assumed. In the electrophotography method, the transfer unit and the medium come into contact when an image is transferred to the medium. In this embodiment, the object to be printed is assumed to be a medium having various thicknesses and shapes, such as metal, glass, and tiles.

[0011] <Device configuration> Figure 1 shows the configuration of an image forming apparatus to which this embodiment is applied. The image forming apparatus 10 comprises a transfer unit 100, a fixing unit 200, a media attachment / detachment unit 300, and a transport mechanism 400. Although not specifically shown, the image forming apparatus 10 also comprises a control unit having one or more processors as computing means, memory as a work area for data processing, and a storage device for holding programs and data. The control unit may be a single unit that controls the operation of the entire image forming apparatus 10, or it may be provided individually for each of the transfer unit 100, fixing unit 200, transport mechanism 400, etc.

[0012] The transfer unit 100 is a unit that transfers an image formed from particles such as toner onto the medium 500. The fixing unit 200 is a unit that fixes the image transferred by the transfer unit 100 to the surface of the medium 500 by heating the medium 500. The medium attachment / detachment unit 300 is a unit in which the user of the image forming apparatus 10 attaches the medium 500 to a mounting base (described later) provided on the transport mechanism 400. The transport mechanism 400 is provided throughout the transfer unit 100, the fixing unit 200, and the medium attachment / detachment unit 300, and transports the medium 500 to be printed to each unit 100, 200, and 300 as shown by the arrows in Figure 1.

[0013] The media loading / unloading section 300 is a housing that has an opening in part of it through which the media 500 can be loaded and unloaded. As will be described in more detail later, the inside of the media loading / unloading section 300 contains a portion of the transport rail 410 that constitutes the transport mechanism 400, and the transport start position and transport end position are set there. In this embodiment, the transport start position and the transport end position are set to the same location. In the initial state, the mounting base 420 that constitutes the transport mechanism 400 is placed at the location of the transport rail 410 that is set as the transport start position and the transport end position. When the user inserts the jig 423 holding the media 500 through the opening of the housing of the media loading / unloading section 300 and attaches it to the mounting base 420, the transport mechanism 400 becomes capable of transporting the media 500. After the image is transferred to the media 500 by the transfer section 100 and the fixing process is performed by the fixing section 200, the mounting base 420 on which the media 500 is placed moves along the transport rail 410 to reach the transport end position. In this state, the user removes the jig 423 holding the media 500 from the mounting base 420 and takes it out through the opening in the housing of the media attachment / detachment section 300.

[0014] <Configuration of the transfer unit 100> Figure 2 shows the configuration of the transfer unit 100. The transfer unit 100 forms an image with charged particles and generates an electric field to transfer the image to the medium 500. The transfer unit 100 comprises a developing device 110, a primary transfer roll 120, and an intermediate transfer belt 131. The intermediate transfer belt 131 is stretched between the developing device 110 and the position where the transfer to the medium 500 takes place, by rollers 132, 133 and a backup roll 140. The transfer unit 100 also includes a cleaning device 150 for removing particles adhering to the intermediate transfer belt 131.

[0015] The developing unit 110 is a unit that forms an electrostatic latent image of the image to be transferred onto a photoreceptor and develops the image by attaching charged particles to this electrostatic latent image on the photoreceptor. Existing devices used in electrophotographic image forming apparatuses can be used as the developing unit 110. Figure 2 shows an example configuration for color image forming processing using four colors: yellow, magenta, cyan, and black. A separate developing unit 110 is provided for each of these colors, and in Figure 2, the developing units 110 for yellow, magenta, cyan, and black are indicated with the subscripts Y, M, C, and K, respectively, to represent the corresponding color. In the following description, when distinguishing between the colors in relation to the developing unit 110, the subscripts Y, M, C, and K are added to the symbols; however, when it is not necessary to distinguish between the colors, the subscripts are omitted.

[0016] The primary transfer roll 120 is a unit used to transfer (primary transfer) the image formed in the developing unit 110 to the intermediate transfer belt 131. The primary transfer roll 120 is positioned opposite the photoreceptor of the developing unit 110, and the intermediate transfer belt 131 is positioned between the developing unit 110 and the primary transfer roll 120. The primary transfer roll 120 is provided in correspondence to each of the developing units 110Y, 110M, 110C, and 110K. In Figure 2, each primary transfer roll 120 corresponding to the developing unit 110Y, 110M, 110C, and 110K for each color is indicated with the subscripts Y, M, C, and K to indicate the corresponding color. In the following description, when distinguishing each color with respect to the primary transfer roll 120, the subscripts Y, M, C, and K are added to the symbols, but when it is not necessary to distinguish each color, the subscripts are omitted.

[0017] The intermediate transfer belt 131, rollers 132 and 133, and backup roll 140 are units used to transfer the image formed in the developing apparatus 110 to the medium 500. As shown in Figure 2, the intermediate transfer belt 131 is stretched over the rollers 132 and 133 and the backup roll 140 and rotates in the direction of the arrow in Figure 2 (counterclockwise in the illustrated example). The rotation of the intermediate transfer belt 131 is achieved, for example, by using a roller that rotates one or both of the rollers 132 and 133, and pulling the intermediate transfer belt 131 with the rotation of this roller.

[0018] In the configuration example shown in Figure 2, the outer surface of the intermediate transfer belt 131 is the surface that holds the image (hereinafter referred to as the "transfer surface"). As the intermediate transfer belt 131 passes between the developing device 110 and the primary transfer roll 120, the image is transferred from the photoreceptor of the developing device 110 to the transfer surface of the intermediate transfer belt 131. In the configuration example shown in Figure 2, a multicolor image is formed by superimposing images of yellow (Y), magenta (M), cyan (C), and black (K) onto the transfer surface using the developing devices 110Y, 110M, 110C, 110K and the primary transfer rolls 120Y, 120M, 120C, 120K.

[0019] The backup roll 140 brings the transfer surface of the intermediate transfer belt 131 into contact with the medium 500, transferring the image to the medium (secondary transfer). When transferring the image, a predetermined voltage is applied to the backup roll 140. This generates an electric field (hereinafter referred to as the "transfer electric field") in the area including the backup roll 140 and the medium 500, and the image formed by the charged particles is transferred from the intermediate transfer belt 131 to the medium 500. In this way, in order to transfer the image from the intermediate transfer belt 131 to the medium 500, current must flow from the backup roll 140 through the intermediate transfer belt 131 to the medium 500. If the medium 500 is a conductor such as a metal, current flows through the medium 500 itself, generating a transfer electric field and transferring the image to the surface of the medium 500. On the other hand, if the medium 500 is not a conductor, current does not flow through the medium, and therefore the image cannot be transferred as is. Therefore, when a non-conductor material is used as the medium 500, measures are taken beforehand to allow current to flow through the medium 500, such as forming a layer of conductive material (hereinafter referred to as the "conductive layer") in at least the region on the surface of the medium 500 where the image is to be formed.

[0020] The procedure for transferring an image using the intermediate transfer belt 131 will now be described. As the intermediate transfer belt 131 rotates, the developing devices 110Y, 110M, 110C, 110K and the primary transfer rolls 120Y, 120M, 120C, 120K sequentially superimpose images of yellow (Y), magenta (M), cyan (C), and black (K) onto the transfer surface of the intermediate transfer belt 131 (the outer surface in Figure 2), forming a multicolor image. As the intermediate transfer belt 131 rotates further, the image formed on the transfer surface of the intermediate transfer belt 131 reaches the position where the intermediate transfer belt 131 contacts the medium 500 (hereinafter referred to as the "transfer position"). At this point, as described above, a voltage is applied to the backup roll 140 to generate a transfer electric field, and the image is transferred from the intermediate transfer belt 131 to the medium 500.

[0021] The cleaning device 150 is a unit that removes particles adhering to the transfer surface of the intermediate transfer belt 131. The cleaning device 150 is located downstream of the transfer position in the rotational direction of the intermediate transfer belt 131 and upstream of the developing device 110Y and the primary transfer roll 120Y. As a result, after the image is transferred from the intermediate transfer belt 131 to the medium 500, any particles remaining on the transfer surface of the intermediate transfer belt 131 are removed by the cleaning device 150. Then, in the next operation cycle, a new image is transferred (primary transfer) to the transfer surface from which the particles have been removed.

[0022] <Configuration of the transport mechanism 400 and mounting structure of the media 500> Here, the mounting structure for the medium 500 will be described. In this embodiment, we assume that the medium 500 has various thicknesses and shapes. When the medium 500 is directly placed on a transport path composed of belts and rollers and transported, if the thickness and shape of the medium 500 differ, the height of the medium 500 relative to the transport path will differ at the transfer position of the transfer section 100, making it difficult to properly bring the intermediate transfer belt 131 into contact with the medium 500. Specifically, if the height of the medium 500 is low, the medium 500 will not contact the intermediate transfer belt 131, and if the height of the medium 500 is high, a strong impact may occur when the medium 500 contacts the intermediate transfer belt 131. Therefore, in this embodiment, the transport mechanism 400 places the medium 500 on a mounting base 420 equipped with height control means, and transports the medium 500 together with this mounting base 420.

[0023] Referring to Figure 2, the transport mechanism 400 includes a transport rail 410 that specifies the transport path for the medium 500, and a mounting base 420 that moves along the transport rail 410. The mounting base 420 includes legs 421 attached to the transport rail 410 and a base 422 for placing the medium 500 on. A jig 423 for holding the medium 500 on the base 422 is attached to the base 422. The transport mechanism 400 is an example of a transport unit.

[0024] In the configuration example shown in Figure 1, the transport rail 410 is installed from the media attachment / detachment section 300 through the fixing section 200 to the transfer section 100. The end of the transport rail 410 on the media attachment / detachment section 300 side is the transport start position and the transport end position. The mounting base 420 is transported from the transport start position of the media attachment / detachment section 300 to the left in Figure 1, and the image is transferred to the media 500 in the transfer section 100. After the image transfer, the mounting base 420 is transported to the right in Figure 1, and after the image is fixed to the media 500 in the fixing section 200, it reaches the transport end position of the media attachment / detachment section 300.

[0025] The leg portion 421 is attached to the transport rail 410 and moves along the transport rail 410. The leg portion 421 is an example of a movable body. The mechanism for the leg portion 421 to move along the transport rail 410 is not particularly limited. For example, the leg portion 421 may be equipped with a drive device to allow it to move on its own, or the transport rail 410 may be equipped with means for pulling the leg portion 421. The leg portion 421 also has a height control means for controlling the height of the base portion 422. The configuration of the height control means is not particularly limited. For example, it may be configured to raise and lower the base portion 422 using a rack and pinion and a drive motor. Alternatively, it may be configured to control the height of the base portion 422 by manually operating a gear that is linked to the height of the base portion 422. Furthermore, various methods can be used for operating the height control. For example, an input interface to the control unit of the drive motor may be provided, and the operator of the image forming apparatus 10 may manually input and set the height data using the input interface. Alternatively, a sensor may be used to automatically detect the height of the medium 500 mounted on the mounting base 420, and the drive motor may be controlled so that the medium 500 is at an appropriate height.

[0026] The base portion 422 is attached to the leg portion 421 and is a platform on which the medium 500 is placed via the jig 423. The base portion 422 is provided with fasteners (not shown) for positioning the jig 423. Any jig 423 that fits these fasteners can be positioned and attached to the base portion 422 regardless of the shape of the jig 423 itself.

[0027] Furthermore, the base portion 422 is mounted so as to rise and fall relative to the leg portion 421 in response to pressure from above. The rising and falling of the base portion 422 is achieved, for example, by interposing an elastic body at the joint between the base portion 422 and the leg portion 421. With this configuration, the impact when the medium 500 held by the jig 423 attached to the base portion 422 comes into contact with the intermediate transfer belt 131 of the transfer portion 100 is mitigated.

[0028] The jig 423 is a device that holds the medium 500 and is attached to the base portion 422. The part of the jig 423 that is attached to the base portion 422 has a shape and structure that fits the fasteners of the base portion 422. The jig 423 also has a shape for holding the medium 500. Therefore, by preparing a jig 423 according to the shape and size of the medium 500, various shapes and sizes of medium 500 can be placed on the mounting base 420.

[0029] <Pre-processing for image formation> The image forming apparatus 10 of this embodiment has a transport mechanism 400 configured as described above, and can therefore print on media 500 of various shapes and sizes. However, in order to prevent problems such as strong impacts occurring due to contact between the media 500 and the intermediate transfer belt 131 of the transfer unit 100, or failure to make contact, when transferring an image to the media 500, the height of the base unit 422 is controlled before the image transfer operation begins.

[0030] Figure 3 shows the operation of the transport mechanism 400 before image formation by the transfer unit 100 begins. Figure 3(A) shows the height control process, Figure 3(B) shows the mechanism retracted to the preparation position after height control, and Figure 3(C) shows the state when image transfer by the transfer unit 100 begins.

[0031] When image formation is performed on the medium 500, first, at the transport start position of the medium attachment / detachment unit 300, the medium 500 held by the jig 423 is set on the mounting base 420. Then, the height control means of the mounting base 420 lowers the medium 500 to a height where it does not come into contact with the intermediate transfer belt 131 of the transfer unit 100, and then the mounting base 420 with the medium 500 on it moves to below the transfer position of the transfer unit 100.

[0032] Next, the height of the mounting base 420 is controlled so that the medium 500 contacts the intermediate transfer belt 131 with an appropriate strength for transferring the image at the transfer position (arrow a in Figure 3(A)). Once the height control is performed, the information of the obtained appropriate height (hereinafter referred to as the "transfer execution height") is stored in the memory of the control unit. Then, the mounting base 420 is lowered to a height where the medium 500 does not contact the intermediate transfer belt 131 and moves to the preparation position for the transfer operation (arrow b in Figure 3(A)).

[0033] When the mounting base 420 moves to the preparation position, the height of the mounting base 420 is adjusted to the transfer execution height based on the information obtained from the height control. After this, the mounting base 420 moves to the transfer position (arrow c in Figure 3(B)), and when the medium 500 comes into contact with the intermediate transfer belt 131 at the transfer position, the transfer of the image begins (Figure 3(C)).

[0034] <Configuration of the fixing unit 200> Once the image is transferred to the medium 500 in the transfer unit 100, the image is then fixed in the fixing unit 200. In this embodiment, since images are formed on mediums 500 of various thicknesses and shapes, a non-contact fixing process is performed. The fixing unit 200 heats and melts the particles that form the image transferred to the medium 500 and fixes them to the surface of the medium 500.

[0035] Figure 4 shows the configuration and operation of the fixing unit 200. Figure 4(A) shows the fixing unit 200 with its opening closed, and Figure 4(B) shows the fixing unit 200 with its opening open. The fixing unit 200 includes an inlet 201 for loading the medium 500 and an outlet 202 for unloading the medium 500. In addition, the inlet 201 and outlet 202 of the fixing unit 200 in this embodiment are provided with opening and closing members, which are configured to open when loading and unloading the medium 500 and to close when performing the fixing process.

[0036] Here, the opening into which the medium 500 is brought in when the image fixing process is performed by the fixing unit 200 is designated as the inlet 201, and the opening out on the side from which the medium 500 is discharged is designated as the outlet 202. In other words, the opening on the side facing the transfer unit 100 is designated as the inlet 201, and the opening on the side facing the medium attachment / detachment unit 300 is designated as the outlet 202. In the example shown in Figures 4(A) and (B), the opening on the left is the inlet 201, and the opening on the right is the outlet 202. In this embodiment of the image forming apparatus 10, when the medium 500 is transported from the transport start position of the medium attachment / detachment unit 300 to the transfer unit 100, the medium 500 passes through the fixing unit 200. At this time, the medium 500 enters the fixing unit 200 from the outlet 202 and exits from the inlet 201, the opposite of when the fixing process is performed. However, in this embodiment, the inlet 201 and outlet 202 were set as described above based on the operation when the fixing process is performed in the fixing unit 200.

[0037] The fixing unit 200 is equipped with a heat source 210 for heat fixing. Various existing heat sources such as halogen lamps, ceramic heaters, and infrared lamps can be used as the heat source 210. Alternatively, instead of the heat source 210, a device that heats the particles forming the image by irradiating them with an infrared laser may be used. The fixing unit 200 in this embodiment is provided with a covering member that can cover the heat source 210, and is configured to expose the heat source 210 when performing the fixing process.

[0038] In the example shown in Figures 4(A) and (B), retractable shutters 220 and 230 are provided as opening and closing members for the loading entrance 201 and the loading exit 202. The shutters 220 and 230 are kept closed except when loading or unloading the medium 500 (see Figure 4(A)) to prevent the internal temperature from dropping. When loading the medium 500, the shutter 220 of the loading entrance 201 opens, and when unloading the medium 500, the shutter 230 of the loading exit 202 opens (see Figure 4(B)).

[0039] Furthermore, in the examples shown in Figures 4(A) and (B), a retractable shutter 240 is provided as a covering member to cover the heat source 210. The shutter 240 closes when the shutters 220 and 230 of the entrance 201 and exit 202 are opened (see Figure 4(B)). This makes it possible to suppress the temperature drop of the heat source 210 even when the temperature inside drops due to the opening of the entrance 201 and exit 202.

[0040] In the example shown in Figure 4(B), both the shutter 220 of the loading entrance 201 and the shutter 230 of the loading exit 202 are shown open, but this is for the sake of explanation. In actual operation, the shutter 230 of the loading exit 202 is kept closed when loading the media 500, and the shutter 220 of the loading entrance 201 is kept closed when loading the media 500. This prevents the internal temperature from dropping.

[0041] The shutters 220, 230, and 240 shown in Figures 4(A) and (B) are examples of opening and closing members for the loading entrance 201 and loading exit 202, and covering members for the heat source 210. These opening and closing members and covering members only need to suppress the decrease in temperature inside the fixing section 200 and the heat source 210, and are not limited to the above configuration. For example, instead of the shutters 220, 230, and 240 shown in Figures 4(A) and (B), opening and closing doors may be provided. Also, as the opening and closing member for the loading exit 202 through which the medium 500 passes after the fixing process is complete, a curtain or air curtain made of insulating material may be used to prevent the leakage of internal air.

[0042] <Configuration of mounting base 420> Next, the configuration of the mounting base 420 will be described in more detail. As explained with reference to Figure 2, the image forming apparatus 10 of this embodiment transfers the image formed on the intermediate transfer belt 131 of the transfer unit 100 to the medium 500 by bringing the intermediate transfer belt 131 of the transfer unit 100 into contact with the medium 500. An elastic body is interposed between the legs 421 and the base 422 of the mounting base 420, so that the base 422 can rise and fall, thereby mitigating the impact when the medium 500 comes into contact with the intermediate transfer belt 131. In other words, the mounting base 420 changes its height in accordance with the force with which the intermediate transfer belt 131 comes into contact with the medium 500. A specific example of this configuration for changing the height of the base 422 will be explained.

[0043] Figure 5 shows the structure of the mounting base 420. Figure 5(A) shows a first configuration example, and Figure 5(B) shows a second configuration example. In the first configuration example shown in Figure 5(A), the base portion 422 is supported by a plurality of springs 424 on the upper surface of the leg portion 421. The springs 424 are compression springs, and in the illustrated example, they are coil springs. When the mounting base 420 receives pressure from above, each spring 424 compresses in accordance with the pressure received, causing the base portion 422 to sink. Then, when the pressure from above acting on the mounting base 420 decreases, the base portion 422 is pushed up by the rebound of the springs 424. The plurality of springs 424 are independent of each other and individually support the base portion 422. Therefore, the base portion 422 not only sinks, but also tilts according to the position where pressure is received. The springs 424 are an example of an elastic body.

[0044] In the second configuration example shown in Figure 5(B), an elastic sheet 425 is provided between the base portion 422 and the leg portion 421. By interposing the sheet 425 between the base portion 422 and the leg portion 421, when the mounting base 420 receives pressure from above, the sheet 425 collapses in accordance with the pressure received, causing the base portion 422 to sink. Then, when the pressure from above acting on the mounting base 420 decreases, the elasticity of the sheet 425 pushes the base portion 422 upward. The sheet 425 collapses partially around the area where pressure is received in accordance with the local pressure. Therefore, the base portion 422 not only sinks but also tilts in accordance with the location where pressure is received. In the example shown in Figure 5(B), a single plate-shaped sheet 425 is shown, but multiple sheets of different materials may be stacked to obtain appropriate elasticity and flexibility for supporting the base portion 422. The sheet 425 is an example of an elastic member.

[0045] Figure 6 shows the change in height of the mounting base 420 during transfer, with Figure 6(A) showing the state at the start of transfer, Figure 6(B) showing the state during transfer, and Figure 6(C) showing the state at the end of transfer. Figures 6(A), (B), and (C) show an example using the mounting base 420 shown in Figure 5(A), which supports the base portion 422 by a spring 424. In the examples shown in Figures 6(A), (B), and (C), the transfer portion 100 comes into contact with the medium 500 and transfers the image as the mounting base 420, on which the medium 500 is placed, moves from left to right in the figure (see each arrow).

[0046] At the start of the transfer, the leading end of the medium 500 in the transport direction first comes into contact with the intermediate transfer belt 131 of the transfer unit 100. Since the position of the intermediate transfer belt 131 is fixed by the backup roll 140, when the intermediate transfer belt 131 and the medium 500 come into contact, the medium 500 experiences downward pressure at the point of contact with the intermediate transfer belt 131. As a result, as shown in Figure 6(A), the leading end of the base portion 422 of the mounting base 420 in the transport direction sinks due to the spring 424, causing the entire base portion 422 to tilt.

[0047] As the image transfer to the medium 500 progresses, the contact position of the intermediate transfer belt 131 on the medium 500 moves in the opposite direction of the transport. As a result, as shown in Figure 6(B), the entire base portion 422 of the mounting base 420 sinks due to the spring 424. Then, at the end of the transfer, as shown in Figure 6(C), the rear end of the base portion 422 of the mounting base 420 sinks in the transport direction, and the entire base portion 422 tilts.

[0048] In this way, the base portion 422 of the mounting base 420 changes its height by tilting in response to the force applied by the contact between the transfer portion 100 and the medium 500, so that the force with which the transfer portion 100 presses against the medium 500 during image transfer remains within a certain range. In addition, the impact when the transfer portion 100 contacts the medium 500 is mitigated.

[0049] <Example configuration of jig 423> In this embodiment, the image forming apparatus 10 is held by a jig 423 configured according to the shape and size of the medium 500, and the medium 500 is mounted on the mounting base 420 by attaching the jig 423 to the base portion 422. The jig 423 holds the medium 500 by pressing down on at least a portion of the parts of the medium 500 other than the surface on which the image is transferred. The jig 423 only needs to be capable of stably mounting the medium 500 to the mounting base 420, and can be configured in various ways depending on the shape and size of the medium 500. The jig 423 will be described below with some specific examples.

[0050] Figure 7 shows a first configuration example of the jig 423. Figure 7(A) is a side view, and Figure 7(B) is a top view. The jig 423 comprises a base plate 423a on which the medium 500 is placed, and a pressing part 423b that holds down the medium 500 placed on the base plate 423a. The pressing part 423b is provided to hold down and fix the medium 500 from at least the front in the transport direction while it is placed on the base plate 423a. In the configuration example shown in Figure 7, the jig 423 holds down and fixes the medium 500 from the front and rear (left and right in the figure) in the transport direction. This prevents the position of the medium 500 from shifting in the transport direction due to the impact when the transfer unit 100 and the medium 500 come into contact.

[0051] Furthermore, the pressing portion 423b of the jig 423 has a specific height corresponding to the height of the medium 500 placed on the base plate 423a. When the transfer unit 100 transfers an image to the medium 500, the base portion 422 of the mounting base 420 rises and falls, as explained with reference to Figures 5 and 6. As a result, the intermediate transfer belt 131 first contacts the pressing portion 423b on the front side of the jig 423 in the transport direction, and then contacts the medium 500. Therefore, the height of the pressing portion 423b is set to a height such that the impact caused by the contact of the transfer unit 100 does not affect the image formed on the intermediate transfer belt 131.

[0052] Figure 8 shows the contact between the jig 423, the medium 500, and the intermediate transfer belt 131 of the transfer unit 100 at the start of the transfer. Figure 8(A) shows the state in which the jig 423 and the intermediate transfer belt 131 are in contact, and Figure 8(B) shows the state in which the medium 500 and the intermediate transfer belt 131 are in contact. As shown in Figures 8(A) and (B), when the jig 423 that holds the medium 500 is attached to the base portion 422 of the mounting base 420 and transported, first the pressing portion 423b on the front side in the transport direction of the jig 423 comes into contact with the intermediate transfer belt 131 (Figure 8(A)). Then, as the mounting base 420 moves further, the front end of the medium 500 in the transport direction comes into contact with the intermediate transfer belt 131 (Figure 8(B)), and the transfer of the image begins. In this case, if the height difference between the medium 500 and the pressing part 423b is large, the impact due to contact will be large on both the medium 500 and the intermediate transfer belt 131. Therefore, the height difference between the medium 500 and the pressing part 423b should be kept below a certain level. For example, the upper limit of the height difference between the medium 500 and the pressing part 423b may be set to the smaller of 1 / 2 the height of the medium 500 or 3 mm.

[0053] Figure 9 shows a second example of the configuration of the jig 423. Figure 9(A) is a side view, and Figure 9(B) is a top view. In the examples shown in Figures 9(A) and (B), the medium 500 is a plate-shaped member with a protruding portion on one side and an image formed on the other side. An example of such a medium 500 is a name tag with an attachment portion on the back for attaching to clothing, etc. In the jig 423 shown in Figures 9(A) and (B), a groove 423c is formed in the base plate 423a to accommodate the protruding portion of the medium 500. In the examples shown in Figures 9(A) and (B), the groove 423c in the base plate 423a of the jig 423 creates a space for the protruding portion on one side of the medium 500 to recede, but the protruding portion of the medium 500 may also be fixed in place by the groove 423c. For example, the groove 423c may be equipped with claws that engage with the protruding portion of the medium 500, or gripping means that grip the protruding portion of the medium 500, and the medium 500 may be fixed to the jig 423 by fitting the protruding portion into the groove 423c.

[0054] Figure 10 shows a third example of the jig 423 configuration. Figure 10(A) is a side view, and Figure 10(B) is a top view. In the examples shown in Figures 10(A) and (B), a slope is formed on the end of the pressing portion 423b that does not come into contact with the medium 500. Specifically, the pressing portion 423b on the front side in the transport direction of the jig 423 is sloped to become lower toward the front in the transport direction, and the pressing portion 423b on the rear side in the transport direction of the jig 423 is sloped to become lower toward the rear in the transport direction. With this configuration, as explained with reference to Figure 8(A), the impact when the pressing portion 423b and the intermediate transfer belt 131 of the transfer portion 100 come into contact is further reduced. In the illustrated example, slopes are formed on both the pressing portion 423b on the front and rear sides in the transport direction of the medium 500, but it is sufficient if at least the pressing portion 423b on the front side in the transport direction is sloped.

[0055] Figure 11 shows a fourth configuration example of the jig 423, where Figure 11(A) is a side view and Figure 11(B) is a top view. In the examples shown in Figures 11(A) and (B), the medium 500 is such that at least the front and rear ends in the transport direction cannot be exposed when the image is transferred. In this case, as shown in Figures 11(A) and (B), it is conceivable to hold the medium 500 with a jig 423 such that the height of the pressing portion 423b is greater than or equal to the height of the ends of the medium 500. As described with reference to Figures 5 and 6, the image forming apparatus 10 of this embodiment has a base portion 422 of the mounting base 420 that rises and falls, so even when the height of the pressing portion 423b is higher than the height of the ends of the medium 500, as shown in Figures 11(A) and (B), the image can be transferred.

[0056] Figure 12 shows how the jig 423 and the medium 500 come into contact with the intermediate transfer belt 131 of the transfer unit 100 when the jig 423 according to the fourth configuration example is used. Figure 12(A) shows the state in which the jig 423 and the intermediate transfer belt 131 are in contact, and Figure 12(B) shows the state in which the medium 500 and the intermediate transfer belt 131 are in contact. As shown in Figures 12(A) and (B), when the jig 423 that holds the medium 500 is attached to the base portion 422 of the mounting base 420 and transported, first the pressing portion 423b on the front side in the transport direction of the jig 423 comes into contact with the intermediate transfer belt 131 (Figure 12(A)). Then, as the mounting base 420 moves further, the medium 500 comes into contact with the intermediate transfer belt 131 (Figure 12(B)), and the transfer of the image begins. At this time, the base portion 422 of the mounting base 420 is pushed up by the repulsive force of the spring 424 and sheet 425 as explained with reference to Figures 5 and 6, so that even if the medium 500 is lower than the pressing portion 423b of the jig 423, it will come into contact with the intermediate transfer belt 131.

[0057] Although not as pronounced as in the example explained with reference to Figure 8, in the example shown in Figure 12, a large difference in height between the medium 500 and the pressing portion 423b results in a large impact when the medium 500 and the intermediate transfer belt 131 come into contact. Therefore, the difference in height between the medium 500 and the pressing portion 423b should be kept below a certain level. For example, the upper limit of the height difference between the medium 500 and the pressing portion 423b may be set to the smaller of 1 / 2 the height of the medium 500 or 3 mm. In addition, in the example shown in Figure 12, a slope is formed on the end of the pressing portion 423b of the jig 423 that comes into contact with the medium 500. This configuration further reduces the impact when the pressing portion 423b and the medium 500 come into contact.

[0058] <Example of mounting structure for jig 423> The jig 423 may have a shape that corresponds individually to each medium 500, but the mounting structure to the base portion 422 of the mounting base 420 is standardized. This allows various shapes and sizes of mediums 500 to be mounted on the mounting base 420 by using the jig 423. The mounting structure of the jig 423 is not particularly limited as long as it is a structure that positions and fixes the jig 423 on the base portion 422. As an example, fasteners that interlock and fix each other may be provided on one or both of the base portion 422 and the jig 423. The mounting structure of the jig 423 using fasteners will be described below with some specific examples.

[0059] Figure 13 shows an example of a fastener for attaching a jig 423 to the base portion 422 of a mounting base 420. Figure 13(A) is a side view, and Figure 13(B) is a top view. In the example shown in Figures 13(A) and (B), abutment 422a is provided on the base portion 422 as a fastener to press against the outer circumference of the jig 423. In this example, it is assumed that the outer shape of the jig 423 is rectangular. The abutment 422a rises up toward the upper surface of the base portion 422 at positions corresponding to the four corners of the jig 423 when the jig 423 is placed on the base portion 422. Each abutment 422a is formed in a "V" shape that matches the corresponding corner of the jig 423, as shown in Figure 13(B). The four corners of the jig 423 fit into these four abutments 422a, thereby positioning the jig 423 on the base 422 and restricting its movement in a direction parallel to the surface of the base 422. When attaching the jig 423 to the base 422, the corners of the jig 423 are aligned so that they fit into the four abutments 422a, and the jig 423 is placed from above the base 422.

[0060] In the examples shown in Figures 13(A) and (B), the abutments 422a are positioned to correspond to the four corners of the jig 423. However, the placement of the abutments 422a is not limited to the illustrated examples, as long as it positions the jig 423 and restricts its movement. For example, with the jig 423 placed on the base portion 422, plate-shaped abutments 422a may be placed at positions corresponding to the four sides of the jig 423. In addition, even if the outer shape of the jig 423 is not rectangular, the jig 423 can be attached to the base portion 422 by positioning the abutments 422a according to its shape.

[0061] Figure 14 shows another example of a fastener for attaching a jig 423 to the base portion 422 of the mounting base 420. Figure 14(A) is a side view, and Figure 14(B) is a top view. In the examples shown in Figures 14(A) and (B), a pin 422b is provided as a fastener to connect the base portion 422 and the jig 423. In this example, holes are provided at corresponding positions on the base portion 422 and the jig 423, respectively. One end of the pin 422b is inserted into the hole in the base portion 422, and the other end is inserted into the hole in the jig 423, thereby positioning the jig 423 on the base portion 422 and restricting its movement in a direction parallel to the surface of the base portion 422. When attaching the jig 423 to the base portion 422, insert the pin 422b into the hole in the base portion 422, align the position of the hole in the jig 423 with the position of the pin 422b, and place the jig 423 from above the base portion 422.

[0062] In the examples shown in Figures 14(A) and (B), holes are provided in both the base portion 422 and the jig 423 for inserting the pins 422b. Alternatively, a pin 422b may be formed on the upper surface of the base portion 422, and the pin 422b may be inserted into a hole formed in the jig 423 corresponding to the position of this pin 422b. Conversely, a pin 422b may be formed on the lower surface of the jig 423, and the pin 422b may be inserted into a hole formed in the base portion 422 corresponding to the position of this pin 422b. In the examples shown in Figures 14(A) and (B), the four pins 422b and holes are arranged so that they form the four vertices of a rectangle, but the arrangement of the pins 422b is not limited to the illustrated example, as long as it positions the jig 423 and restricts its movement. When using pin 422b as a fastener, the outer circumference of the jig 423 is not pressed down as with abutment 422a as explained with reference to Figures 13(A) and (B), so the external shape of the jig 423 is not restricted.

[0063] Figure 15 shows another example of a fastener for attaching a jig 423 to the base portion 422 of the mounting base 420. Figure 15(A) is a side view, and Figure 15(B) is a top view. In the examples shown in Figures 15(A) and (B), the base portion 422 is provided with claws 422c as fasteners that hook onto the outer circumference of the jig 423. In this example, it is assumed that the outer shape of the jig 423 is rectangular. Protrusions 423d for hooking the claws 422c are formed on the front and rear sides of the outer circumference of the jig 423 in the direction of transport. The claws 422c are positioned to press down on the protrusions 423d of the jig 423 from the front and rear in the direction of transport when the jig 423 is placed on the base portion 422. Each claw 422c is configured to open upward either in conjunction or individually. By placing the jig 423 on the base portion 422 and closing the claws 422c, the jig 423 is positioned on the base portion 422 and its movement in the transport direction and upward is restricted.

[0064] In the examples shown in Figures 15(A) and (B), the claws 422c are positioned to press down on the jig 423 from the front and rear in the conveying direction. However, additional claws 422c may be provided to press down on the jig 423 from a direction intersecting the conveying direction. Also, in the examples shown in Figures 15(A) and (B), the protruding edges 423d of the jig 423 are provided along the entire front and rear edges in the conveying direction. However, the protruding edges 423d may be provided only at the points where they are pressed down by the claws 422c.

[0065] Although embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the above embodiments. For example, in the above embodiments, with respect to the elastic body used in the configuration that causes the base portion 422 of the mounting base 420 to rise and fall, Figures 5(A) and 6 show an example in which a coil spring is used as the spring 424. However, the type of spring is not limited as long as multiple springs 424 independently support the base portion 422 with a certain repulsive force. Instead of the illustrated coil spring, leaf springs or disc springs may be used. Alternatively, instead of the spring 424, multiple small pieces of an elastic member such as rubber may be arranged to support the base portion 422. The shape of the jig 423 and the structure for attaching the jig 423 to the base portion 422 of the mounting base 420 are not limited to the specific examples described with reference to the drawings. Furthermore, various modifications and substitutions of configurations that do not deviate from the technical concept of the present invention are included in the present invention.

[0066] <Note> (((1))) An image forming apparatus comprising: a transfer unit that contacts an object and transfers an image onto the object; a mounting base on which the object is attached and whose height changes according to the force with which the transfer unit contacts the object; and a transport unit that transports the mounting base on which the object is attached along a transport path. (((2))) The image forming apparatus according to (((1))), characterized in that the mounting base fixes the object to at least the transport direction by the transport unit. (((3))) The image forming apparatus according to (((1))) or (((2))), further comprising a jig for holding down at least a portion of the object other than the surface on which the image is transferred, and the mounting base comprising a fastener for positioning and fixing the jig. (((4))) The image forming apparatus according to (((3))), characterized in that the jig holds the object from at least in front of the direction in which the object is transported by the transport unit, and the transfer unit contacts the jig before starting the transfer of the image, and then contacts the object to start the transfer of the image. (((5))) The image forming apparatus according to (((3))) or (((4))), characterized in that the portion of the jig located in front of the object in the transport direction is inclined to become lower toward the front in the transport direction. (((6))) The image forming apparatus according to any one of (((1))) to (((5))), characterized in that the mounting base changes its height while tilting in accordance with the force applied when the transfer portion comes into contact with the object. (((7))) The mounting base comprises a movable body portion that moves along the transport path by the transport portion and a base portion on which the object is placed, and the base portion is independently supported at multiple points by elastic bodies relative to the movable body portion, characterized in that the image forming apparatus according to any one of (((1))) to (((6))). (((8))) The mounting base is characterized by comprising a movable body portion that moves along the transport path by the transport portion, a base portion on which the object is placed, and a plate-shaped elastic member sandwiched between the base portion and the movable body portion, as described in any of (((1))) to (((6))).

[0067] According to the image forming apparatus described in (((1))), compared to a configuration in which a medium is placed on a transport means and transported, it is possible to suppress the deterioration of print quality caused by the displacement of the object due to impact. According to the image forming apparatus described in (((2))), compared to a configuration in which a medium is placed on a transport means and transported, it is possible to suppress displacement of the object due to contact with the transfer unit during the transport of the object. According to the image forming apparatus described in (((3))), compared to a configuration in which an object is attached to a mounting base without using a jig, it becomes easier to attach objects of various shapes and sizes to the mounting base by using a jig appropriate to the object. According to the image forming apparatus described in (((4))), compared to a configuration in which the transfer unit contacts the object without contacting the jig, the impact when the transfer unit contacts the object can be reduced. According to the image forming apparatus described in (((5))), the impact when the transfer part comes into contact with the jig can be reduced compared to a configuration in which the jig is not tilted. According to the image forming apparatus described in (((6))), compared to a configuration in which the mounting base is not tilted, the impact when the object and the transfer unit come into contact can be mitigated. According to the image forming apparatus described in (((7))), by independently supporting elastic bodies at multiple locations, each elastic body sinks individually, enabling vertical movement accompanied by inclination. According to the image forming apparatus described in (((8))), by sandwiching a plate-shaped elastic body, vertical movement accompanied by inclination becomes possible depending on the contact point between the object and the transfer section. [Explanation of symbols]

[0068] 10…Image forming apparatus, 100…Transfer section, 110…Developing apparatus, 120…Primary transfer roll, 131…Intermediate transfer belt, 132, 133…Rollers, 140…Backup roll, 150…Cleaning apparatus, 200…Fixing section, 201…Inlet, 202…Outlet, 210…Heat source, 220, 230, 240…Shutter, 300…Media loading / unloading section, 400…Conveying mechanism, 410…Conveying rail, 420…Mounting base, 421…Legs, 422…Base, 422a…Butt, 422b…Pin, 422c…Claw, 423…Jig, 423a…Base plate, 423b…Pressing part, 423c…Groove, 423d…Protrusion, 424…Spring, 425…Sheet, 500…Media

Claims

1. A transfer unit that comes into contact with an object and transfers an image onto the object, A mounting base on which the object is attached, and on which the height of the transfer portion changes according to the force with which the object is in contact with the object, A transport unit that transports the mounting base on which the object is attached along a transport path, Equipped with, The mounting base is characterized by changing its height while tilting in accordance with the force applied when the transfer portion comes into contact with the object, in an image forming apparatus.

2. The image forming apparatus according to claim 1, characterized in that the mounting base fixes the object at least in the direction of transport by the transport unit.

3. The object further comprises a jig for holding down at least a portion of the surface other than the surface on which the image is transferred. The image forming apparatus according to claim 2, characterized in that the mounting base is provided with fasteners for positioning and fixing the jig.

4. The jig holds the object from at least the front in the direction of transport of the object by the transport unit, The image forming apparatus according to claim 3, characterized in that the transfer unit contacts the jig before starting the transfer of the image, and then contacts the object to start the transfer of the image.

5. The image forming apparatus according to claim 4, characterized in that the portion of the jig located in front of the object in the transport direction is inclined to become lower toward the front in the transport direction.

6. The aforementioned mounting base is A moving body that moves along the transport path by the transport unit, It comprises a base portion on which the object is placed, The image forming apparatus according to claim 1, characterized in that the base portion is independently supported at multiple points by elastic bodies relative to the movable body portion.

7. The aforementioned mounting base is A moving body that moves along the transport path by the transport unit, A base on which the object is placed, A plate-shaped elastic member sandwiched between the base portion and the movable portion, The image forming apparatus according to claim 1, characterized by comprising:

Images